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  • 1.
    Al Jawaheri, Raad
    et al.
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap.
    Sahlén, Göran
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Negative impact of lake liming programmes on the species richness of dragonflies (Odonata): a study from southern Sweden2017Inngår i: Hydrobiologia, ISSN 0018-8158, E-ISSN 1573-5117, Vol. 788, nr 1, s. 99-113Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Liming programmes aiming to restore fish populations are being implemented in many acidified aquatic systems in northern Europe. We studied Odonata communities in 47 forest lakes in SW Sweden, 13 that are currently being limed, and 8 that have previously been limed. Thirty-one species were recorded, with the highest mean number in untreated lakes, followed by previously treated lakes and currently treated lakes. Species communities differed between untreated and limed lakes, but only few rare species found in the untreated lakes were absent in the treated lakes. Likewise, species known to thrive in acid environments were either rare or showed no preferences. Comparing the number of records of odonate species within a large regional area to the proportion of lakes inhabited in our study, we found that seven of the most commonly observed species occurred less frequently in limed lakes than in the untreated ones, including two of the three most common taxa. Reduced species numbers in limed lakes might be due to conditions on other trophic levels, including fish predation. We argue that Odonata should be considered when developing new biological indices of water quality, although the causes of the observed occurrence patterns need to be studied further. © 2016 Springer International Publishing Switzerland

  • 2.
    Almström, Jennie
    et al.
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET).
    Gustavsson, Simon
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET).
    Styrketräning en gång per vecka förbättrade anaerob kapacitet hos cyklister och triathleter: En 12 veckor lång interventionsstudie2012Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Triathleter och cyklister är uthållighetsidrottare med extrem träningsvolym och stort krav på aerob kapacitet, dock krävs även anaerob- power och muskelstyrka för delmoment som backar och tempoväxlingar. Många uthållighetsidrottare tvekar över att implementera styrketräning i tron att effekten ska påverka deras prestation negativt, dessutom gör den höga träningsvolymen det svårt att kombinera. Styrketräning som komplement till uthållighetsträning har dock visats ge positiv effekt och kan förslagsvis förbättra prestation. Syftet var att undersöka huruvida ett styrketräningspass per vecka kan förbättra anaerob kapacitet hos cyklister och triathleter samt om en eventuellt ökad benstyrka kan påverka simtiden hos triathleter. Metoden var en interventionsstudie med pre- och posttest där deltagarna fick genomföra ett styrketräningspass innehållandes tre övningar, en gång per vecka under 12 veckors tid, som komplement till ordinarie träning. Resultatet vid test av maximal styrka i benpressmaskin påvisade en signifikant ökad benstyrka för interventionsgruppen med p = 0,001, en styrkeförbättring på 16,5 %. Wingate- testet visade signifikant förbättring för maxeffekt, p = 0,003, en förbättring med 11,1 % samt maxeffekt per kilo kroppsvikt, p = 0,001, en förbättring på 11,9 %. För kontrollgruppen sågs inga noterbara förändringar och inget samband kunde heller ses mellan en ökad benstyrka och simprestation.Vår styrketräning i kombination med deras ordinarie träning kan förslagsvis fungera synergiskt och optimera prestationen. 

  • 3.
    Andersen, Emelie
    et al.
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap.
    Nilsson, Bertil
    Högskolan i Halmstad, Akademin för informationsteknologi, Halmstad Embedded and Intelligent Systems Research (EIS), Tillämpad matematik och fysik (MPE-lab).
    Sahlén, Göran
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Bio- och miljösystemforskning (BLESS).
    Survival possibilities of the dragonfly Aeshna viridis (Insecta, Odonata) in southern Sweden predicted from dispersal possibilities2016Inngår i: Journal of Insect Conservation, ISSN 1366-638X, E-ISSN 1572-9753, Vol. 20, nr 2, s. 179-188Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We use public records from 1980 to 2014 to analyse survival of the EU Annex IV species Aeshna viridis in Sweden, a dragonfly strongly associated with the plant Stratiotes aloides. We clustered localities with S. aloides based on assumed dispersal abilities of A. viridis, using a dispersing radius of 2–100 km, calculating the proportion of sites with S. aloides that A. viridis is able to reach. If mean dispersal capability is high (40 km or above) 92.6 % or more of the localities are connected. For a good disperser, the probability of long-time survival is good. We further analysed the species richness of other Odonata and aquatic plants at 98 localities from the dataset. A. viridis co-occurred with more Odonata in the presence of S. aloides and running water but not in lakes. S. aloides sites had a higher number of other aquatic plants. Area had no impact on the occurrence of the species. For the present situation we surveyed 32 localities with known occurrence of the species. Only half of the sites for S. aloides contained any specimens while A. viridis occurred in the same number of sites. The species co-occurred in only 8 of 32 sites. In four sites A. viridis larvae appeared among Menyanthes trifoliata, Phragmites australis, Potamogeton natans and Sphagnum spp., indicating that at high latitudes A. viridis breeds among other species. Indirect monitoring based only on S. aloides would underestimate the number of populations of the dragonfly. © 2016 Springer International Publishing Switzerland

  • 4.
    Andersson, Emma
    Högskolan i Halmstad.
    A study of how fragmentation affects distribution and diversity among Nymphalidae, Papilionidae and Pieridae (Lepidoptera): in native and exotic forest fragments in southern Brazil2015Independent thesis Basic level (degree of Bachelor), 15 poäng / 22,5 hpOppgave
  • 5.
    Andersson, Julia
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap.
    Does clearcutting as a method for forestry impact the aquatic life in lakes nearby?2016Independent thesis Advanced level (degree of Master (One Year)), 10 poäng / 15 hpOppgave
    Abstract [en]

    Clearcutting is the most common method for forestry in Sweden. However research shows that this type of intense management can have a negative impact on biological biodiversity as it interferes with an area’s natural characteristics. Previous studies have mainly focused on biological effects on land. In this study dragonflies were used as biological indicators to investigate the impact of clearcutting in aquatic environments. The result from this study indicate that the use of clearcutting as a method for forestry can, with a certain postponement in time, negatively affect the species diversity of Odonata, and thus also the aquatic biodiversity in lakes in the immediate surroundings of a clearcut area, although it is still unclear exactly how and by which mechanisms. It is also uncertain if the effects are only temporarily, or long-term. If Sweden is to reach the environmental goal of Flourishing Lakes and Streams, it is essential to adopt further safety measures when conducting clearcutting near waters to avoid negative impact on the aquatic biological diversity.

  • 6.
    Anstrén, Ludwig
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap.
    The Reliability of Cooper ́s Test in Subjects Between 28-60 Years of Age2015Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    Background: Maximal oxygen uptake (VO2max) is a determinant of an individual’s ability to handle oxygen during maximal exercise. To measure VO2max expensive equipment and expertise personnel are required. To make the process of measuring VO2max easier, several submaximal and maximal tests have been created in which an estimation of VO2max could be made. Cooper’s 12-minute run (12MR) was created in 1968 and was tested on 115 military men with a mean age of 22 years. Since then the 12MR test has been re- tested and validated towards maximal treadmill tests on several occasions. When an age of 30 years is reached, VO2max starts to decline with 9-10 percent per decade but can be halted by different forms of exercise. With exercise of moderate to high intensity the decline can be halted by almost 50 percent. Objective: To investigate the reliability of estimated VO2max in a test retest scenario of Cooper ́s 12MR on a mixed healthy population between the ages of 28-60. Method: Nine women and five men, healthy subjects with a mean age of 43 ± 8 participated in the present study. A test retest of Cooper ́s 12MR took place with a minimum of seven days between tests. The subjects had to run as many laps as possible on the track during a 12-minute period. Finished laps were then counted and the fraction of the last lap was measured with a measuring wheel and then added to the total distance. To estimate the subjects’ VO2max Cooper ́s table was used. Results: The single measure Intraclass correlation (ICC) that was found, between the estimated VO2max made from the initial test to the retest on Cooper ́s 12MR, was 0.979. ICC showed a small error variance correlation between the tests and was close to the optimal correlation of 1.0. Conclusion: A standardized protocol for performing Cooper ́s 12MR showed good repeatability for estimating VO2max in two separate tests for a mixed population between 28 to 60 years of age. 

  • 7.
    Aronsson, Henrik
    et al.
    Department of Biology, Leicester University, Leicester, United Kingdom.
    Sundqvist, Christer
    Department of Plant Physiology, Göteborg University, Göteborg, Sweden.
    Dahlin, Clas
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Bio- och miljösystemforskning (BLESS), Växtcellbiologi: Energiomvandling i växtceller.
    POR – import and membrane association of a key element in chloroplast development2003Inngår i: Physiologia Plantarum: An International Journal for Plant Biology, ISSN 0031-9317, E-ISSN 1399-3054, Vol. 118, nr 1, s. 1-9Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The development of proplastids or etioplasts to chloroplast is visualized by the accumulation of chlorophyll in leaves of higher plants. The biosynthesis of chlorophyll includes a light-dependent reduction of protochlorophyllide (Pchlide) to chlorophyllide (Chlide). This light-dependent step is catalysed by the nucleus-encoded NADPH:Pchlide oxidoreductase (POR, EC 1.6.99.1). POR is active within plastids and therefore has to be translocated over the plastid envelope membranes. The import of chloroplast proteins seems to follow a general import pathway using translocons at the outer and inner envelope membrane. POR cross-linking to Toc75, one of the major translocon components at the outer envelope membrane, indicates its use of the general import pathway. However, since variations exist within the so-called general import pathway one has to consider previous data suggesting a novel totally Pchlide-dependent import pathway of one POR isoform, PORA. The suggested Pchlide dependency of POR import is discussed since recent observations contradict this idea. In the stroma the POR transit peptide is cleaved off and the mature POR protein is targeted to the plastid inner membranes. The correct and stable association of POR to the membrane requires the cofactor NADPH. Functional activity of POR calls for formation of an NADPH–Pchlide–POR complex, a formation that probably takes place after the membrane association and is dependent on a phosphorylation reaction.

  • 8.
    Aronsson, Henrik
    et al.
    Department of Biology, Leicester University, United Kingdom.
    Sundqvist, Christer
    Department of Plant Physiology, Göteborg University, Göteborg, Sweden.
    Dahlin, Clas
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET), Bio- och miljösystemforskning (BLESS), Växtcellbiologi: Energiomvandling i växtceller.
    POR hits the road: import and assembly of a plastid protein2003Inngår i: Plant Molecular Biology, ISSN 0167-4412, E-ISSN 1573-5028, Vol. 51, nr 1, s. 1-7Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The biosynthesis of chlorophyll is a strictly light-dependent multistep process in higher plants. The light-dependent step is catalysed by NADPH:protochlorophyllide oxidoreductase (POR, EC.1.6.99.1), which reduces protochlorophyllide (Pchlide) to chlorophyllide (Chlide). POR is nucleus-encoded and post-translationally imported into plastids. It has been proposed that the import of a POR protein isozyme (PORA) is totally dependent on Pchlide and uses a novel import pathway. This proposal is based on findings that PORA import only occurs in the presence of Pchlide and that the presence of overexpressed precursor of Rubisco small subunit (pSS), a protein which is known to use the general import pathway, does not outcompete PORA import. Another study demonstrated that POR precursor protein (pPOR) can be cross-linked to one of the components in the translocation machinery, Toc75, in the absence of Pchlide, and that its import can be outcompeted by the addition of the pSS. This indicates that pSS and pPOR may use the same translocation mechanism. Thus, POR does not necessarily need Pchlide for import – which is in contrast to earlier observations – and the exact POR import mechanism remains unresolved. Once in the stroma, the POR transit peptide is cleaved off and the mature POR protein is associated to the plastid inner membranes. Formation of the correct membrane–associated, thermolysin-protected assembly is strictly dependent of NADPH. As a final step, the formation of the NADPH-Pchlide-POR complex occurs. When POR accumulates in the membranes of proplastids, an attraction of monogalactosyl diacylglycerol (MGDG) can occur, leading to the formation of prolamellar bodies (PLBs) and the development of etioplasts in darkness.

  • 9.
    Aronsson, Henrik
    et al.
    Department of Plant Physiology, Göteborg University, Göteborg, Sweden.
    Sundqvist, Christer
    Department of Plant Physiology, Göteborg University, Göteborg, Sweden.
    Timko, Michael P.
    Department of Biology, University of Virginia, Charlottesville, United States.
    Dahlin, Clas
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Bio- och miljösystemforskning (BLESS).
    Characterisation of the assembly pathway of the pea NADPH:protochlorophyllide (Pchlide) oxidoreductase (POR), with emphasis on the role of its substrate, Pchlide2001Inngår i: Physiologia Plantarum: An International Journal for Plant Biology, ISSN 0031-9317, E-ISSN 1399-3054, Vol. 111, nr 2, s. 239-244Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The homologous import and membrane association of a key enzyme for chlorophyll biosynthesis, the NADPH:protochlorophyllide (Pchlide) oxidoreductase (PAR, EC 1.6.99.1) into pea chloroplasts was investigated in vitro. The co-factor, NADPH, decreased binding of the precursor protein (pPOR) to the envelope membranes in the presence of ATP. The decrease of the binding reaction with NADPH was not observed with the precursor of the small subunit of Rubisco (pSS). To investigate possible substrate-dependency for the import reaction, internal Pchlide concentrations in the plastids were raised by either an addition of ÎŽ-aminolevulinic acid to isolated plastids or etiolation of the seedlings prior to plastid isolation. Increased amounts of plastid-bound Pchlide gave no observable differences in POR import. The capacity of POR and 11 different POR mutants, carrying charged-to-alanine scanning substitutions, to form a catalytically active POR-Pchlide-NADPH complex and to associate with the thylakoid membranes in a protease-resistant way were tested. Wild-type POR, as well as the mutants with charge substitutions in the N-terminal region of the protein, exhibited higher catalytic activity than the POR mutants carrying substitutions in the C-terminal region. Formation of a catalytically active complex did not, however, increase the association efficiency onto the thylakoids. We can, therefore, postulate that the import of pea POR into pea chloroplasts was not substrate-dependent, nor did formation of catalytically active complexes stimulate or inhibit the membrane association reaction of POR.

  • 10.
    Bartholdsson, David
    Högskolan i Halmstad.
    Den invasiva vresrosens (Rosa rugosa) etablering samt återetablering i de sanddominerade miljöerna i Gullbranna/Tönnersa naturreservat2018Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Vresrosen, Rosa rugosa, är en kraftigt invasiv art med en oerhörd konkurrenskraft i sanddominerademiljöer såsom sanddyner och sandblottor. Ofta leder etableringen av R. rugosa i dessasanddominerade miljöer till total igenväxning av området med en starkt negativ påverkan på deninhemska floran och faunan. Då merparten av arterna i dessa habitat är beroende av den unika miljönsom den skiftande sanden skapar så innebär igenväxningen ett mycket stort hot. När området bindsupp till en mer stabil miljö utan det permanent tidiga successionsstadium som den vanligtvis befinnersig i så påverkar det även näringsmängden i sanden med ökade näringshalter samt att de varma, öppnamicrositesen försvinner tillsammans med sandens förmåga att röra sig. Eftersom många av deovanliga och hotade arterna kräver en väldigt specifik miljö så försvinner de ofta också närigenväxningen nått så här långt. Denna studie fokuserar på vresrosens etablering och påverkan isanddominerade miljöer. Studien går även in forskning kring samt hur man praktiskt bekämparväxten, då den hotar många ekologiskt viktiga områden. Dessutom hanterar rapporten mina egnaresultat efter inventeringar i Gullbranna/Tönnersa, ett område som historiskt sett varit mycket hårtpåverkat av vresrosen.

  • 11.
    Berggren, Thomas
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Bio- och miljösystemforskning (BLESS), Biovetenskap.
    Does type of habitat affect tick-burden in roe deer (Capreolus capreolus) neonates?2015Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    This study was investigating the relationships between: 1) habitat type and tick abundance, 2) habitat type and tick load on fawns, and 3) tick load and fawn survival. During two years and in two study areas, 105 fawns (57 fawns in Bogesund and 48 fawns in Grimsö) have been captured by hand and equipped with a radio-transmitter. The fawns’ positions have then been triangulated almost every day until they died or had at least 30 positions. The surviving fawns were recaptured when they were estimated to have a weight of 3.6 kg. Ticks were collected from the fawns during both the capture and the recapture. By using the flagging-method, in which a white sheet is dragged along the ground, ticks were also collected from the vegetation. A vegetation map was used to determine the habitat on transects and the home range of the fawns. The study areas showed different results regarding in which habitat the ticks were found. At Grimsö ticks seems to favor deciduous forest and mixed forest not on mires. At Bogesund the favored tick habitat was instead coniferous forest with trees between five to fifteen meters. In Bogesund there was a positive correlation between tick-burden and percent of coniferous forest on lichen-dominated areas that covered fawn home ranges. No relationship could be found between ticks and the survival of the fawns. A positive correlation between surviving days and tick load during first capture could instead be found on fawns that died within 30 days.

  • 12.
    Bergström, Jakob
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap.
    Vedlevande Coleoptera och Hemiptera förekomst på öar i Kolsnaren i sydvästra Södermanland2017Independent thesis Basic level (degree of Bachelor), 180 hpOppgave
    Abstract [en]

    ABSTRACT

    Seven islands in the lake Kolsnaren have been investigated. I have inventoried saproxylic insects and investigated what characters on dead wood and characters at the islands that have affected species number of beetles (Coleoptera) and true bugs (Hemiptera). This study shows a relatively low number of species of beetles and true bugs but the study was too small to estimate a proper result. Probably there is many more species, especially more rare/threatened species. The characters vary between islands, but even the individual islands had different tree species, thickness, degradation stage and sun exposure of dead wood. Therefore there were favourable conditions for many different saproxylic species that have different demands of the habitat to find suitable substrate. The islands are partly isolated by water but no longer distances. With that in mind it was important that there is plenty of dead wood with varying characters around Kolsnaren so they get the opportunity to disperse and recolonise the islands when even the habitats are changing in time. The dead woods thickness and degradation stage was the characters with most impact of the number of species.

  • 13.
    Bonnot, N. C.
    et al.
    Grimsö Wildlife Research Station, Department of Ecology, Swedish University of Agricultural Sciences, Riddarhyttan, 730 91, Sweden.
    Bergvall, U. A.
    Grimsö Wildlife Research Station, Department of Ecology, Swedish University of Agricultural Sciences, Riddarhyttan, 730 91, Sweden.
    Jarnemo, Anders
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Kjellander, P.
    Grimsö Wildlife Research Station, Department of Ecology, Swedish University of Agricultural Sciences, Riddarhyttan, 730 91, Sweden.
    Who’s afraid of the big bad wolf?: Variation in the stress response among personalities and populations in a large wild herbivore2018Inngår i: Oecologia, ISSN 0029-8549, E-ISSN 1432-1939, Vol. 188, nr 1, s. 85-95Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Faced with rapid environmental changes, individuals may express different magnitude and plasticity in their response to a given stressor. However, little is known about the causes of variation in phenotypic plasticity of the stress response in wild populations. In the present study, we repeatedly captured individual roe deer (Capreolus capreolus) from two wild populations in Sweden exposed to differing levels of predation pressure and measured plasma concentrations of stress-induced cortisol and behavioral docility. While controlling for the marked effects of habituation, we found clear between-population differences in the stress-induced cortisol response. Roe deer living in the area that was recently recolonized by lynx (Lynx lynx) and wolves (Canis lupus) expressed cortisol levels that were around 30% higher than roe deer in the human-dominated landscape free of large carnivores. In addition, for the first time to our knowledge, we investigated the stress-induced cortisol response in free-ranging newborn fawns and found no evidence for hypo-responsiveness during early life in this species. Indeed, stress-induced cortisol levels were of similar magnitude and differed between populations to a similar extent in both neonates and adults. Finally, at an individual level, we found that both cortisol and docility levels were strongly repeatable, and weakly negatively inter-correlated, suggesting that individuals differed consistently in how they respond to a stressor, and supporting the existence of a stress-management syndrome in roe deer. © 2018, The Author(s).

  • 14.
    Brönmark, Christer
    et al.
    Limnology, Department of Ecology, Lund University, Lund, Sweden.
    Weisner, Stefan E. B.
    Limnology, Department of Ecology, Lund University, Lund, Sweden.
    Indirect effects of fish community structure on submerged vegetation in shallow, eutrophic lakes: an alternative mechanism1992Inngår i: Hydrobiologia, ISSN 0018-8158, E-ISSN 1573-5117, Vol. 243/244, nr 1, s. 293-301Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The loss of submerged macrophytes during eutrophication of shallow takes is a commonly observed phenomenon. The proximate reason for this decline is a reduction of available light due to increasing phytoplankton and/or epiphyton biomass. Here we argue that the ultimate cause for the transition from a macrophyte-dominated state to a phytoplankton-dominated state is a change in fish community structure. A catastrophic disturbance event (e.g. winterkill) acting selectively on piscivores, cascades down food chains, eventually reducing macrophyte growth through shading by epiphyton, an effect that is reinforced by increasing phytoplankton biomass. The transition back from the phytoplankton to the macrophyte state depends on an increase in piscivore standing stock and a reduction of planktivores. A conceptual model of these mechanisms is presented and supported by literature data and preliminary observations from a field experiment. © 1992 Kluwer Academic Publishers.

  • 15.
    Brönmark, Christer
    et al.
    Limnology, Department of Ecology, Lund University, Lund, Sweden.
    Weisner, Stefan E.B.
    Limnology, Department of Ecology, Lund University, Lund, Sweden.
    Decoupling of cascading trophic interactions in a freshwater, benthic food chain1996Inngår i: Oecologia, ISSN 0029-8549, E-ISSN 1432-1939, Vol. 108, nr 3, s. 534-541Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Food chain theory provides explicit predictions for equilibrium biomasses among trophic levels in food chains of different lengths. Empirical studies on freshwater benthic food chains have typically been performed on chains with up to three levels and in field experiments with limited spatial and temporal scale. Here we use a ‘’natural snapshot experiment” approach to study equilibrium biomass and abundance among trophic levels in natural ponds differing only with respect to fish assemblage structure. Forty-four ponds were surveyed for their density and biomass of fish, snails and periphyton. Ponds were divided into three categories based on fish assemblage: ponds with no fish (two trophic levels), ponds with molluscivorous fish (three trophic levels), ponds with molluscivorous fish (three trophic levels) and ponds that also had piscivorous fish (four trophic levels). Ponds without fish had a high density and biomass of snails and a low biomass of periphyton, whereas snails with molluscivorous fish. In the presence of piscivores, molluscivore populations consisted of low numbers of large individuals. Snail assemblages in piscivore ponds were characterised by relatively high densities of small-bodied detritivorous species and periphyton biomass was not significantly different from ponds with three trophic levels. Thus, predictions from classic food chain theory were upheld in ponds with up to three trophic levels. In ponds with four trophic levels, however, there was a decoupling of the trophic cascade at the piscivore-molluscivore level. Gape-limited piscivory, predation on snails by molluscivores that have reached an absolute size refuge from predation, and changes in food preferences of the dominant snails are suggested to explain the observed patterns.

  • 16.
    Cameron, J.
    et al.
    DiLab i Lund AB.
    Jacobson, C.
    AstraZeneca R and D.
    Nilsson, Kenneth
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS).
    Rögnvaldsson, Thorsteinn
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), Halmstad Embedded and Intelligent Systems Research (EIS).
    A biometric approach to laboratory rodent identification2007Inngår i: Lab animal, ISSN 0093-7355, E-ISSN 1548-4475, Vol. 36, nr 3, s. 36-40Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Individual identification of laboratory rodents typically involves invasive methods, such as tattoos, ear clips, and implanted transponders. Beyond the ethical dilemmas they may present, these methods may cause pain or distress that confounds research results. The authors describe a prototype device for biometric identification of laboratory rodents that would allow researchers to identify rodents without the complications of other methods. The device, which uses the rodent's ear blood vessel pattern as the identifier, is fast, automatic, noninvasive, and painless.

  • 17.
    Cardol, Pierre
    et al.
    Genetics of Microorganisms, University of Liège, Liège, Belgium.
    Figueroa, Francisco
    Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias, Universidad de Córdoba. Campus de Rabanalles, Edif. Severo Ochoa, Córdoba, Spain.
    Remacle, Claire
    Genetics of Microorganisms, University of Liège, Liège, Belgium.
    Franzén, Lars-Gunnar
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Bio- och miljösystemforskning (BLESS), Växtcellbiologi: Energiomvandling i växtceller.
    González-Halphen, Diego
    Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Colonia Copilco-Universidad, Delegación Coyoacán, México D.F., Mexico.
    Oxidative Phosphorylation: Building blocks and related components2009Inngår i: The Chlamydomonas Sourcebook: Organellar and Metabolic Processes, Volume 2, Second Edition / [ed] Elizabeth H. Harris, David B. Stern & George B. Witman, Oxford: Academic Press, 2009, s. 469-502Kapittel i bok, del av antologi (Annet vitenskapelig)
    Abstract [en]

    This chapter summarizes the knowledge of the oxidative phosphorylation (OXPHOS) constituents of Chlamydomonas and of the components involved in their biogenesis and addresses alternate dehydrogenases and oxidases which are particular to photosynthetic organisms, and several other mitochondrial components related to OXPHOS. Reference to the components of Polytomella sp., a colorless alga closely related to Chlamydomonas is clearly made. The main complexes involved in electron transport seem to share a similar number of subunits, and many of the algal polypeptides have plant homologues. Some differences are apparent, such as the presence of a fragmented COX2 subunit, which seems to be unique to chlorophyte algae. OXPHOS is defined as an electron transfer chain driven by substrate oxidation that is coupled to the synthesis of ATP through an electrochemical transmembrane gradient. The characterization of Arabidopsis mitochondrial components through proteomic approaches has advanced significantly. As a unicellular organism, Chlamydomonas offers the unique opportunity to study organelle-organelle interactions, particularly between mitochondria and chloroplasts. It has become evident that crosstalk between these organelles takes place, mainly through intracellular metabolite pools. © 2009 Elsevier Inc. All rights reserved.

  • 18.
    Carlzon, Linnéa
    et al.
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap.
    Karlsson, Amanda
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap.
    Falk, Knud
    www.vandrefalk.dk, Stockholm, Sweden.
    Liess, Antonia
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Møller, Søren
    Roskilde University Library, Roskilde, Denmark.
    Extreme weather affects Peregrine Falcon (Falco peregrinus tundrius) breeding success in South Greenland2018Inngår i: Ornis Hungarica, ISSN 1215-1610, Vol. 26, nr 2, s. 38-50Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In order to better understand the potential effects of climate change on the Peregrine Falcon, we investigated the relationship between extreme weather events and Peregrines’ breeding success in South Greenland. We defined three variables – number of days with extremely low temperatures, extreme precipitation, consecutive rainy days – and an additive variable, total days with extreme weather, and tested their relationship with Peregrines’ breeding success (measured as young per site and nest success) over a 33 year study period. Breeding success was negatively influenced by the number of days with extreme weather and extremely low temperature. The strongest relationship found was total days with extreme weather in the entire breeding season, which explained 22% and 27% of the variation in nest success and young per site, respectively. The number of days with extreme weather in our study related to fluctuations in the North Atlantic Oscillation (NAO). Thus, with a strengthening of the NAO, linked to climate change, more extreme weather may occur in the Arctic and induce increased variation in Peregrines’ breeding success. Our data did not allow us to pinpoint when in the breeding cycle inclement weather was particularly harmful, and we recommend finer-scale research (e.g. automated nest cameras) to better monitor the species-specific effects of rapidly changing climate.

  • 19.
    Celander, Patrik
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap.
    Strandsandjägaren (Cicindela maritima) i Gullbranna, Tönnersa- och Hökafältets naturreservat– förekomst, hot och förslag till bevarandeåtgärder2019Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Det halländska kustdynlandskapet har utsatts hårt historiskt av framförallt igenväxning, men även andra faktorer som exploatering och friluftsliv har påverkat. Plantering av bergtall och gräs på sanddynerna, för att förhindra sandflykten som drabbade bönderna redan på 1600- talet, gjorde att nästan hela kustdynlandskapet var täckt med vegetation på 1800- talet. Mellan 2012- 2018 restaurerades stora delar av Laholmsbuktens sanddynreservat i samverkan med EU- projektet SandLife, vilkas syfte var att bevara sanddynmiljön, samt gynna dess hotade arter. I sanddynmiljön lever många evertebrater, däribland skalbaggen strandsandjägaren, som i rödlistningsbedömningen 2015 är klassad som Sårbar i Sverige och är föremål för ett nationellt åtgärdsprogram för dess långsiktiga bevarande. Södra Sveriges troligen enda återstående större population återfinns i Gullbranna naturreservat, som tillsammans med Tönnersa- och Hökafältets naturreservat utgör Laholmsbuktens sanddynreservat. Strandsandjägaren lever i Halland längs havsstränder och vid åmynningar, där dess larver gräver tunnlar i lätt fuktig hårt packad fin sand. Tillbakagången av strandsandjägaren i detta habitat tros överensstämma med tillbakagången av det forna dynamiska kustdynlandskapet.

    Detta arbete har gått ut på att inventera larver av strandsandjägare i Laholmsbuktens sanddynreservat, att utvärdera om arten gynnats av de storskaliga sanddynrestaureringarna i samband med SandLifeprojektet 2012-2018, samt urskilja hot och förslag till konkreta bevarandeåtgärder. Jag fann att populationen har ökat betydligt de senaste 15 åren, dock inte till följd av riktade åtgärder utan troligen tack vare den nybildning av habitat som stormen Gudrun åstadkom 2005, samt att en viss spridning av populationen kan ses. Åtgärdsprogrammets långsiktiga mål fram till 2025 är dock inte uppnått än, men en positiv trend syns och möjligheterna finns i Halland att närma sig målet ytterligare. Restaureringarna inom SandLife verkar inte gynnat strandsandjägarpopulationen, då inga nyrestaurerade områden koloniserats, vilket indikerar att riktade bevarandeåtgärder krävs. En stor och förmodligen mycket underskattad störning i området är trampslitage, så åtgärder behöver vidtas genom att t.ex. sätta upp informationsskyltar och göra vissa lämpliga områden där larver hittats svårtillgängliga. Hela 97% av larvpopulationen, som räknades till 3287 larver, återfanns i augusti på näset i Gullbranna naturrservat, på en bara 6 m bred och 435 m lång yta, av habitattypen sandrevlar/åmynningar. I Tönnersa- och Hökafältets naturreservat fann jag bara enstaka larver längs habittypen havsstrand, men dock är det första gången som strandsandjägarlarver hittats i de områdena. Näst största lokalen med strandsandjägare hittades på norra stranden av Gullbrannas naturreservat, med 44 larver räknade i augusti. Resultatet indikerar att havsstränderna är ett sekundärt val för strandsandjägaren i området, och att de inre sanddynerna/sänkorna i nuläget inte verkar erbjuda lämpligt habitat överhuvudtaget, då inga larver återfanns i den habitattypen. Sandrevlar/mynningar är alltså det mest gynnsamma habitatet i området, men då inga larver hittades vid den andra ån Lagan så indikerar det att fler faktorer spelar in, inte minst frånvaro av alltför kraftigt trampslitage. Orsaken till att Genevadsåns mynning hyser nästan hela populationen är troligen att där finns ännu mycket bra habitat, strandsandjägarens troligen små hemområden med låg spridningstendens vid goda förutsättningar och få störningar. Resterande områden har mindre bra habitat, låg spridning till dessa områden, samt mer störningar. Med riktade åtgärder finns det dock potential för flera metapopulationer i de andra områdena, vilket kan leda till en livskraftigare population av strandsandjägaren i Halland.

  • 20.
    Dalzochio, Marina Schmidt
    et al.
    Laboratório de Ecologia e Evolução, Universidade do Vale do Taquari – UNIVATES, Lajeado, Brazil.
    Périco, Eduardo
    Laboratório de Ecologia e Evolução, Universidade do Vale do Taquari – UNIVATES, Lajeado, Brazil.
    Renner, Samuel
    Laboratório de Ecologia e Evolução, Universidade do Vale do Taquari – UNIVATES, Lajeado, Brazil.
    Sahlén, Göran
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Description of the final stadium larva of Erythrodiplax media (Odonata: Libellulidae) with preliminary key to known South American larvae in the genus2018Inngår i: International Journal of Odonatology, ISSN 1388-7890, Vol. 21, nr 2, s. 93-104Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The larva of Erythrodiplax media is described and illustrated based on two exuviae of reared larvae and one final stadium larva collected in Xangri-lá, State of Rio Grande do Sul, Brazil. The larva of E. media can be distinguished from other species of Erythrodiplax by the presence of lateral spines on S8 and S9, the number of premental setae (n = 22), palpal setae (n = 7) and by the mandibular formula. We also provide a preliminary key to known South American larvae in the genus. © 2018 Worldwide Dragonfly Association.

  • 21.
    David, M.
    et al.
    Inst. National de la Recherche Agronomique, UMR Environnement et Grandes Cultures, Thiverval-Grignon, France.
    Loubet, B.
    Inst. National de la Recherche Agronomique, UMR Environnement et Grandes Cultures, Thiverval-Grignon, France.
    Cellier, P.
    Inst. National de la Recherche Agronomique, UMR Environnement et Grandes Cultures, Thiverval-Grignon, France.
    Mattsson, Marie
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET), Bio- och miljösystemforskning (BLESS).
    Schjoerring, J.K.
    Plant and Soil Science Laboratory, University of Copenhagen, Faculty of Life Sciences, Copenhagen, Denmark.
    Nemitz, E.
    Centre for Ecology and Hydrology (Edinburgh Research Station), Bush Estate, Penicuik, Midlothian ,UK.
    Roche, R.
    Inst. National de la Recherche Agronomique, UMR Environnement et Grandes Cultures.
    Riedo, M.
    Inst. fur Agrarokologie, Bundesforschungsanstalt fur Landwirtschaft (FAL), Braunschweig, Germany.
    Sutton, M.A.
    Centre for Ecology and Hydrology (Edinburgh Research Station), Bush Estate, Penicuik, Midlothian ,UK.
    Ammonia sources and sinks in an intensively managed grassland canopy2009Inngår i: Biogeosciences, ISSN 1726-4170, E-ISSN 1726-4189, Vol. 6, nr 9, s. 1903-1915Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Grasslands represent canopies with a complex structure where sources and sinks of ammonia (NH3) may coexist at the plant level. Moreover, management practices such as mowing, hay production and grazing may change the composition of the sward and hence the source-sink relationship at the canopy level as well as the interaction with the atmosphere. There is therefore a need to understand the exchange of ammonia between grasslands and the atmosphere better, especially regarding the location and magnitude of sources and sinks. Fluxes of atmospheric NH3 within a grassland canopy were assessed in the field and under controlled conditions using a dynamic chamber technique (cuvette). These cuvette measurements were combined with extraction techniques to estimate the ammonium (NH+4 ) concentration and the pH of a given part of the plant or soil, leading to an estimated ammo- nia compensation point (Cp ). The combination of the cuvette and the extraction techniques was used to identify the poten- tial sources and sinks of NH3 within the different compart- ments of the grassland: the soil, the litter or senescent “litter leaves”, and the functioning “green leaves”. A set of six field experiments and six laboratory experiments were performed in which the different compartments were either added or removed from the cuvettes.The results show that the cuvette measurements agree with the extraction technique in ranking the strength of compartment sources. It suggests that in the studied grassland the green leaves were mostly a sink for NH3 with a compensation point around 0.1–0.4 μg m−3 and   an NH3 flux of 6 to 7 ng m−2 s−1. Cutting of the grass did not increase the NH3 fluxes of the green leaves. The litter was found to be the largest source of NH3 in the canopy, with a Cp of up to 1000μgm−3 NH3 andanNH3 fluxupto90ngm−2 s−1. The litter was found to be a much smaller NH3 source when dried (Cp =160 μg m−3 and FNH3 =35 ng m−2 s−1 NH3 ). Moreover emissions from the litter were found to vary with the relative humidity of the air. The soil was a strong source of NH3 in the period immediately after cutting (Cp =320 μg m−3 and FNH3 =60 ng m−2 s−1 ), which was nevertheless always smaller than the litter source. The soil NH3 emissions lasted, however, for less than one day, and were not observed with sieved soil. They could not be solely explained by xylem sap flow extruding NH+4 . These results indicate that future research on grassland-ammonia relationships should focus on the post-mowing period and the role of litter in interaction with meteorological conditions.

  • 22.
    Dejenfelt, Pontus
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap.
    Våtmarksfåglar i Stjärnarp, en inventering av nyanlagd våtmark utanför Halmstad, Halland2019Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Genom en kombinerad linjetaxering och revirkartering av nyanlagd våtmark i Stjärnarpsdalen utanför Halmstad under april-juni 2018 har jag undersökt artsammansättning, antal individer och par samt häckningskriteria hos fågelarter på plats. En jämförelse har gjorts med fem andra våtmarker i Halland i fråga om artsammansättning och häckninggskriteria för att undersöka om ålder eller storlek hos våtmarker har en effekt på dessa. Efter flertalet besök i Stjärnarp observerades totalt 55 arter varav 31 nyttjade våtmarken för antingen häckning, födosök eller rastade. Totalt 19 arter visade tecken på häckning inom våtmarkens gränser, varav endast fem arter slutligen fick ut avkomma. Hos samtliga undersökta våtmarker varierade antal arter mer under 2018, när de var av olika ålder, jämfört med när de alla var ungefär ett år gamla. Jag fann inga signifikanta korrelationer, beroenden eller skillnader mellan undersökta variabler, med undantag för signifikant korrelation och beroende mellan antal möjliga häckningar och area hos våtmarker. Enligt flera källor kan våtmarkers egenskaper och utformning ha stor betydelse för fåglars förekomst, t ex våtmarkens storlek, ålder, vattendjup, skötsel, placering, närvaro av fisk och mycket mer. I denna studie har Stjärnarp visats hysa arter som bl a häckar, och flera dessa arter indikerar på egenskaper som tidig succession, näringsrikt vatten, öppna strandängar och mer. Beroende på vad för fåglar och annan biologisk mångfald man vill gynna här i framtiden är planering och kontinuerligt uppföljningsarbete viktigt för att se om och hur fågelfaunan förändras samt vad det kan bero på.

  • 23.
    Diehl, Sebastian
    et al.
    Department of Ecology and Environmental Sciences, Umeå University, Umeå, Sweden & Integrated Science Lab (IceLab), Umeå University, Umeå, Sweden.
    Thomsson, Gustaf
    Department of Ecology and Environmental Sciences, Umeå University, Umeå, Sweden.
    Kahlert, Maria
    Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Uppsala, Sweden.
    Guo, Junwen
    Department of Ecology and Environmental Sciences, Umeå University, Umeå, Sweden.
    Karlsson, Jan
    Department of Ecology and Environmental Sciences, Umeå University, Umeå, Sweden.
    Liess, Antonia
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Inverse relationship of epilithic algae and pelagic phosphorusin unproductive lakes: Roles of N2 fixers and light2018Inngår i: Freshwater Biology, ISSN 0046-5070, E-ISSN 1365-2427, Vol. 63, nr 7, s. 662-675Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    1. Phosphorus (P) often limits the biomass of primary producers in freshwater lakes. However, in unproductive northern lakes, where anthropogenic nitrogen (N) deposition is low, N instead of P can limit primary producers. In addition, light can be limiting to primary producers at high concentrations of coloured dissolved organic matter (cDOM), as cDOM is the major determinant of light penetration in these lakes.

    2. To address resource limitation of epilithic algal biomass, we repeatedly sampled epilithon (periphyton on stony substrata) in 20 lakes covering a large, correlated cDOM and N-deposition gradient across boreal and subarctic Sweden. Across these lakes, pelagic total N (TN) and total P (TP) were positively correlated, and benthic light supply was negatively correlated, with cDOM. Microscopically determined algal biovolume and epilithic carbon (C), N and P were subsequently regressed against benthic light supply and pelagic TN and TP.

    3. Patterns in epilithic biovolume were driven by N2-fixing cyanobacteria, which accounted for 2%–90% of total epilithic biovolume. Averaged over the growing season, epilithic algal biovolume, C and N were negatively related to TP and positively to TN, and were highest in the clearest, most phosphorus-poor lakes, where epilithon was heavily dominated by potentially N2-fixing cyanobacteria.

    4. A structural equation model supports the hypothesis that cDOM had two counteracting effects on total epilithic algal biovolume: a positive one by providing N to algae that depend on dissolved N for growth, and a negative one by shading N2-fixing cyanobacteria, with the negative effect being somewhat stronger.

    5. Together, these findings suggest that (1) light and N are the main resources limiting epilithic algal biomass in boreal to subarctic Swedish lakes, (2) epilithic cyanobacteria are more competitive in high-light and low-nitrogen environments, where their N2-fixing ability allows them to reach high biomass, and (3) epilithic N increases with N2 fixer biomass and is—seemingly paradoxically—highest in the most oligotrophic lakes. © 2018 John Wiley & Sons Ltd

  • 24.
    Domeij Hilliges, Isak
    et al.
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET).
    Stendahl, Cecilia
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET).
    Ocean acidification effects on marine organisms: a study of Littorina littorea and Balanus improvisus 2011Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    The world’s oceans are becoming more acid in a process called ocean acidification. The pH of the ocean have already decreased by 0.1 units from pre-industrial time until today. Scientists predict that by the year of 2100 the pH will decrease by as much as 0.4 units. This is a big potential problem to many marine species, because they have developed in such a stable environment that has not changed for millions of years. It is difficult to predict how they might be affected by such a decrease in pH during a relatively short time period. Several studies have been made on marine species exposed to decreased pH-levels, the results showed changes in their physiology but it is hard to predict how these changes will affect the organism in a long-term scale and if this might change ecosystem dynamics. Our study measured the activity of Littorina littorea and Balanus improvisus when exposed to lower pH, the results of our study showed an increase in activity for the lower pH (pH 6.0-7.5) when compared to the control (~pH8). The area of ocean acidification is a field that requires further studies to fully understand its effects on the marine ecosystems and the species within it.

  • 25.
    Engdahl, Sheila
    et al.
    University of Gothenburg, Gothenburg, Sweden.
    Aronsson, Henrik
    University of Gothenburg, Gothenburg, Sweden.
    Sundqvist, Christer
    University of Gothenburg, Gothenburg, Sweden.
    Timko, Michael P.
    University of Virginia, Charlottesville, USA.
    Dahlin, Clas
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Bio- och miljösystemforskning (BLESS).
    Association of the NADPH: protochlorophyllide oxidoreductase (POR) with isolated etioplast inner membranes from wheat2001Inngår i: The Plant Journal, ISSN 0960-7412, E-ISSN 1365-313X, Vol. 27, nr 4, s. 297-304Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Membrane association of NADPH:protochlorophyllide oxidoreductase (POR, EC: 1.6.99.1) with isolated prolamellar bodies (PLBs) and prothylakoids (PTs) from wheat etioplasts was investigated. in vitro-expressed radiolabelled POR, with or without transit peptide, was used to characterize membrane association conditions. Proper association of POR with PLBs and PTs did not require the presequence, whereas NADPH and hydrolysable ATP were vital for the process. After treating the membranes with thermolysin, sodium hydroxide or carbonate, a firm attachment of the POR protein to the membrane was found. Although the PLBs and PTs differ significantly in their relative amount of POR in vivo, no major differences in POR association capacity could be observed between the two membrane systems when exogenous NADPH was added, Experiments run with only an endogenous NADPH source almost abolished association of POR with both PLBs and PTs. In addition, POR protein carrying a mutation in the putative nucleotide-binding site (ALA06) was unable to bind to the inner membranes in the presence of NADPH, which further demonstrates that the co-factor is essential for proper membrane association. POR protein carrying a mutation in the substrate-binding site (ALA24) showed less binding to the membranes as compared to the wild type. The results presented here introduce studies of a novel area of protein-membrane interaction, namely the association of proteins with a paracrystalline membrane structure, the PLB.

  • 26.
    Eriksson, Cajza
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap.
    Protectors of the realm: - Are there species, native to Sweden, with higher resistibility to invasions by Lysichiton americanus L.?2019Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    Invasive alien species are one of the biggest threats to biodiversity today, they push away native species and contribute to the loss of natural habitats and biodiversity. American skunk cabbage (Lysichiton americanus), is on the EU “Consolidated List of Invasive Alien Species of Union concern” since 2016 and is locally a problem in Sweden. A pre-study mapping the occurrence and preferred living conditions for L. americanus along Vinån in Falkenberg municipality found about 30,000 individuals. As digging them up with roots, situated 30 cm down in the ground, is the only suitable way of eradication, restoration will probably be necessary, especially areas with high natural values. According to numerous studies, restoration should be done with native species that have the same community traits as the invader. Other studies also indicate that there should be native species that are more resistant to invasions. The aim of the main study was to see if there were plants along Vinån, that are native to Sweden and seemed to have a higher resistibility to L. americanus. The results indicate that Polypodiopsida, Equisetum, Scirpus sylvaticus L., Filipendula ulmaria L. and Phalaris arundinacea L. are in competition with L. americanus and might have a higher resistibility to it. More research is needed before the findings can be implemented in restorations, but by using this study as a stepping stone, the hope is to find an ideal mix of species that could both offer resistance against new invasions of L. americanus and help restore invaded areas with native species. The traits of the species with possible higher resistance is discussed as are the benefits of using native species.

  • 27.
    Eriksson, Peder G
    et al.
    Limnology, Department of Ecology, Lund University, Lund, Sweden .
    Weisner, Stefan E.B.
    Limnology, Department of Ecology, Lund University, Lund, Sweden.
    An experimental study on effects of submersed macrophytes on nitrification and denitrification in ammonium-rich aquatic systems1999Inngår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 44, nr 8, s. 1993-1999Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We have examined the role of microbial communities on the surface of submersed macrophytes and in the underlying sediment for nitrification and denitrification in light and dark in NH(4)(+)-enriched microcosm systems using isotope pairing and dilution techniques. Potamogeton pectinatus L. and intact sediment cores were collected in a shallow reservoir receiving treated municipal wastewater and containing dense submersed vegetation. Chambers containing P. pectinatus shoots, sediment, or both P. pectinatus shoots and sediment were exposed to 6 h of darkness, 6 h of light, and 6 h of darkness. (14)NH(4)(+) and (15)NO(3)(-) were added at ambient concentrations of 15 and 5 mg N liter(-1), respectively. NH(4)(+) was primarily nitrified in the epiphytic microbial communities, and NO; was denitrified in the underlying sediment. In chambers containing macrophytes, there was a net production of O(2) and NO(3)(-) in light and a net consumption in dark, and nitrification was higher in light than in dark. In chambers with only sediment, there was always a net consumption of NO(3)(-), and nitrification was similar in light and dark. The results show that submersed macrophytes can be important for the N metabolism in NH(4)(+)-rich freshwaters (e.g., wastewater treatment systems) by stimulating nitrification through providing surfaces for attached nitrifying bacteria and possibly also through diurnal changes in the water chemistry.

  • 28.
    Eriksson, Peder G.
    et al.
    Limnology, Department of Ecology, Lund University, Lund, Sweden.
    Weisner, Stefan E.B.
    Limnology, Department of Ecology, Lund University, Lund, Sweden.
    Functional differences in epiphytic microbial communities in nutrient-rich freshwater ecosystems: An assay of denitrifying capacity1996Inngår i: Freshwater Biology, ISSN 0046-5070, E-ISSN 1365-2427, Vol. 36, nr 3, s. 555-562Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    1. The denitrifying capacity of epiphyton was used to evaluate differences in the function of epiphytic microbial communities on submersed macrophytes in nutrient-rich freshwater ecosystems. The denitrifying capacity of epiphyton on Patamogeton perfoliatus shoots of different age and with different epiphytic abundances from a eutrophic lake was investigated in laboratory microcosms in the Light and dark. Additionally, differences between epiphyton on shoots of Potamogeton pectinatus grown under different in Situ nutrient and hydraulic conditions were investigated by examining their denitrifying capacity. 2. Denitrification was registered in well-developed epiphytic layers on both mature and senescent shoots in the dark, with activities 3- to 10-fold higher in the epiphytic communities of senescent shoots. No activity was detected on young shoots with sparse epiphyton or on shoots from which loosely attached epiphyton had been removed. Denitrification never occurred during illumination. 3. Even though the epiphytic abundance was similar in magnitude, the denitrifying capacity of epiphyton adapted to high nutrient loadings was about a hundred times higher than that of epiphyton adapted to lower nutrient levels. Additionally, epiphytic abundance and denitrifying capacity were higher at sites less exposed to wave turbulence or water currents, than at sites with more water turbulence. 4. The results illustrate how the hydraulic and nutrient conditions of the surrounding water affect both the quantity and function of epiphytic microbial communities in nutrient-rich freshwater ecosystems.

  • 29.
    Eriksson, Peder G.
    et al.
    Limnology, Department of Ecology, Lund University, Lund, Sweden.
    Weisner, Stefan E.B.
    Limnology, Department of Ecology, Lund University, Lund, Sweden.
    Nitrogen removal in a wastewater reservoir: The importance of denitrification by epiphytic biofilms on submersed vegetation1997Inngår i: Journal of Environmental Quality, ISSN 0047-2425, E-ISSN 1537-2537, Vol. 26, nr 3, s. 905-910Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The aim of this study was to examine the importance of epiphytic denitrifying bacteria on submersed vegetation in removing N from a shallow nutrient-enriched freshwater ecosystem. The investigation was conducted during the summer of 1994 in a surface now reservoir receiving municipal tertiary-treated wastewater. The submersed vegetation in the reservoir was dominated by Potamogeton pectinatus L. and filamentous green algae (FGA). The N loading was 2300 mg N h(-1) m(-2) and the N removal, calculated as the mean difference between influent and effluent N, was 190 mg N h(-1) m(-2) (8%). The majority of influent N consisted of NH4+, but the main part of the N removal was due to the removal of NO3- whereas no net retention of NH4+ was found. Mean total soluble solids and BOD7 retention was 69 and 38%, respectively, Denitrification measurements were conducted in darkness at in situ temperature in microcosms with P. pectinatus, FGA, or infect sediment cores. Epiphytic denitrification ranged between 0.21 to 7.0 mg N h(-1) m(-2) reservoir surface area depending on the abundance of the submersed vegetation (5-140 g DW m(-2)). Sediment denitrification was 4.7 mg N h(-1) m-L reservoir surface area. The mean assimilative N uptake of the submersed vegetation and epiphyton was 3.4 and 1.6 mg N h(-1) m(-2) reservoir surface area, respectively. Measured N removal rates through plant uptake and denitrification could only account for a minor part of the N removal observed by mass balance. However, microcosm denitrification measurements underestimate actual denitrification. Thus, the major part of the N removal was most likely due to denitrification. In conclusion, this study indicates that denitrification in epiphytic microbial communities on submersed vegetation can be of significant importance for the N removal in nutrient-enriched freshwater ecosystems.

  • 30. Eriksson, P.G.
    et al.
    Svensson, J.M.
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET), Bio- och miljösystemforskning (BLESS), Våtmarkscentrum.
    Carrer, M.
    Dipto. Proc. Chimici dell'Ingegneria, Université di Padova, Padua, Italy.
    Temporal changes and spatial variation of soil oxygen consumption, nitrification and denitrification rates in a tidal salt marsh of the Lagoon of Venice, Italy2003Inngår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 58, nr 4, s. 861-871Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The aim of the present study was to investigate seasonal and spatial patterns of soil oxygen consumption, nitrification, denitrification and fluxes of dissolved inorganic nitrogen (DIN) in a tidal salt marsh of the Lagoon of Venice, Italy. In the salt marsh, intact soil cores including overlying water were collected monthly at high tide from April to October in salt marsh creeks and in areas covered by the dominant vegetation, Limonium serotinum. In May, cores were also collected in areas with vegetation dominated by Juncus maritimus and Halimione portulacoides. In laboratory incubations at in situ temperature in the dark, flux rates of oxygen and DIN were monitored in the overlying water of the intact cores. 15N-nitrate was added to the overlying water and nitrification and denitrification were measured using isotope-dilution and -pairing techniques. The results show that highest soil oxygen consumption coincided with the highest water temperature in June and July. The highest denitrification rates were recorded in spring and autumn coinciding with the highest nitrate concentrations. Soil oxygen consumption and nitrification rates differed between sampling sites, but denitrification rates were similar among the different vegetation types. The highest rates were recorded in areas covered with L. serotinum. Burrowing soil macrofauna enhanced oxygen consumption, nitrification and denitrification in April and May. The data presented in this study indicate high temporal as well as spatial variations in the flux of oxygen and DIN, and nitrogen transformations in the tidal salt marshes of the Venice lagoon during the growth season. The results identify the salt marshes of the Venice lagoon as being metabolically very active ecosystems with a high capacity to process nitrogen.

  • 31.
    Evelina, Ohlsson
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET).
    Kunskapsnivån, förståelsen och intresset för naturvård hos elever i nionde klass i Halmstad kommun: En intervjustudie2014Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    I denna studie undersöks hur mycket kunskap och kännedom elever i nionde klass har om naturvård och biologisk mångfald. Även hur stort intresse eleverna har om naturvård studeras. Undersökningen utförs med hjälp av grundad teori. Data samlades in i form av intervjuer, totalt intervjuades 27 elever från fem olika skolor i Halmstad kommun. Elevernas uttalanden graderades på en skala mellan 1-10. Med hjälp av intervjuer och graderingar kan sedan slutsatser dras. Huvudkategorin som identifierades indikerar att eleverna i studien har förmåga att se problem och utmaningar ur ett samhällsperspektiv, vilket är viktigt ur naturvårdssynpunkt då denna disciplin förutom biologiska även inkluderar sociala, ekonomiska och politiska aspekter. Användandet av svenska exempel på naturvård är något som de medverkande eleverna är positivt inställda till och denna kategori har den högsta generella graderingen. Eleverna är intresserade och ser också själva att ytterligare utbildning inom naturvård är viktigt och något som bör finnas med i NO-undervisningen i större utsträckning. Eleverna hade svårt att definiera begrepp som biologisk mångfald och förståelsen för begreppet var inte särskilt utbredd, detta pekar på att metoder bör tas fram som ökar förståelsen för biologisk mångfald och därigenom även naturvård. Studien ger en indikation om att ökad utbildning av allmänheten är behövd och att öka omfattningen av naturvård teoretiskt men även praktiskt i skolundervisningen skulle vara ett bra tillvägagångssätt för att uppnå detta.

  • 32.
    Farkas, Daniel
    et al.
    Institutionen för kemi, Göteborgs Universitet, Department of Chemistry, University of Gothenburg.
    Franzén, Lars-Gunnar
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET), Bio- och miljösystemforskning (BLESS), Växtcellbiologi: Energiomvandling i växtceller.
    Hansson, Örjan
    Institutionen för kemi, Göteborgs Universitet, Department of Chemistry, University of Gothenburg.
    Cloning, expression and purification of the luminal domain of spinach photosystem 1 subunit PsaF functional in binding to plastocyanin and with a disulfide bridge required for folding2011Inngår i: Protein Expression and Purification, ISSN 1046-5928, E-ISSN 1096-0279, Vol. 78, nr 2, s. 156-166Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The photosystem 1 subunit PsaF is involved in the docking of the electron-donor proteins plastocyanin and cytochrome c6 in eukaryotic photosynthetic organisms. Here we report the expression, purification and basic characterization of the luminal domain of spinach PsaF, encompassing amino-acid residues 1-79. The recombinant protein was expressed in Escherichia coli BL21 (DE3) using a pET32 Xa/LIC thioredoxin fusion system. The thioredoxin fusion protein contained a His6 tag and was removed and separated from PsaF through proteolytic digestion by factor Xa followed by immobilized metal affinity chromatography. Further purification with size-exclusion chromatography resulted in a final yield of approximately 6 mg PsaF from one liter growth medium. The correct identity after the factor Xa treatment of PsaF was verified by FT-ICR mass spectrometry which also showed that the purified protein contains an intact disulfide bridge between Cys residues 6 and 38. Secondary structure and folding was further explored using far-UV CD spectroscopy indicating a α-helical content in agreement with the 3.3 Å-resolution crystal structure of photosystem I Ref. [5] and a helix-coil transition temperature of 29 °C. Thermofluorescence studies showed that the disulfide bridge is necessary to keep the overall fold of the protein and that hydrophobic regions become exposed at 50-65 °C depending on the ionic strength. The described expression and purification procedure can be used for isotopic labeling of the protein and 15N-HSQC NMR studies indicated a slow or intermediate exchange between different conformations of the prepared protein and that it belongs to the molten-globule structural family. Finally, by using a carboxyl- and amine-reactive zero-length crosslinker, we have shown that the recombinant protein binds to plastocyanin by a specific, native-like, electrostatic interaction, hence, confirming its functionality.

  • 33.
    Figueroa-Martinez, Francisco
    et al.
    Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico.
    Funes, Soledad
    Institut für Physiologische Chemie, Ludwig-Maximilians-Universität München, Germany .
    Franzén, Lars-Gunnar
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET), Bio- och miljösystemforskning (BLESS), Växtcellbiologi: Energiomvandling i växtceller.
    González-Halphen, Diego
    Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico.
    Reconstructing the mitochondrial protein import machinery of Chlamydomonas reinhardtii2008Inngår i: Genetics, ISSN 0016-6731, E-ISSN 1943-2631, Vol. 179, nr 1, s. 149-155Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In Chlamydomonas reinhardtii several nucleus-encoded proteins that participate in the mitochondrial oxidative phosphorylation are targeted to the organelle by unusually long mitochondrial targeting sequences. Here, we explored the components of the mitochondrial import machinery of the green alga. We mined the algal genome, searching for yeast and plant homologs, and reconstructed the mitochondrial import machinery. All the main translocation components were identified in Chlamydomonas as well as in Arabidopsis thaliana and in the recently sequenced moss Physcomitrella patens. Some of these components appear to be duplicated, as is the case of Tim22. In contrast, several yeast components that have relatively large hydrophilic regions exposed to the cytosol or to the intermembrane space seem to be absent in land plants and green algae. If present at all, these components of plants and algae may differ significantly from their yeast counterparts. We propose that long mitochondrial targeting sequences in some Chlamydomonas mitochondrial protein precursors are involved in preventing the aggregation of the hydrophobic proteins they carry.

  • 34.
    Fleischer, Siegfried
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET).
    CO2 Deficit in Temperate Forest Soils Receiving High Atmospheric N-Deposition2003Inngår i: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 32, nr 1, s. 2-5Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Evidence is provided for an internal CO2 sink in forest soils, that may have a potential impact on the global CO2-budget. Lowered CO2 fraction in the soil atmosphere, and thus lowered CO2 release to the aboveground atmosphere, is indicated in high N-deposition areas. Also at forest edges, especially of spruce forest, where additional N-deposition has occurred, the soil CO2 is lowered, and the gradient increases into the closed forest. Over the last three decades the capacity of the forest soil to maintain the internal sink process has been limited to a cumulative supply of approximately 1000 and 1500 kg N ha−1. Beyond this limit the internal soil CO2 sink becomes an additional CO2 source, together with nitrogen leaching. This stage of “nitrogen saturation” is still uncommon in closed forests in southern Scandinavia, however, it occurs in exposed forest edges which receive high atmospheric N-deposition. The soil CO2 gradient, which originally increases from the edge towards the closed forest, becomes reversed.

  • 35. Fleischer, Siegfried
    et al.
    Bauhn, Lovisa
    Fors, Patrik
    En kolsänka med syrebildning på köpet2014Inngår i: Kemivärlden Biotech med Kemisk Tidskrift, ISSN 1650-0725, nr 4, s. 24-24Artikkel i tidsskrift (Annet vitenskapelig)
  • 36.
    Flenner, Ida
    et al.
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET), Bio- och miljösystemforskning (BLESS).
    Olne, Karin
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET), Bio- och miljösystemforskning (BLESS).
    Suhling, Frank
    Technische Universität Braunschweig.
    Sahlén, Göran
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET), Bio- och miljösystemforskning (BLESS).
    Predator-induced spine length and exocuticle thickness in Leucorrhinia dubia (Insecta: Odonata): a simple physiological trade-off?2009Inngår i: Ecological Entomology, ISSN 0307-6946, E-ISSN 1365-2311, Vol. 34, s. 735-740Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    1. Morphological defence structures evolve against predators but are costly to the individual, and are induced only when required. A well-studied example is the development of longer abdominal spines in dragonfly larvae in the presence of fish. Numerous attempts to discover trade-offs between spine size and behaviour, development time or body size have, however, produced little evidence.

    2. We considered a physiological trade-off. Spines consist of cuticle and using material to build longer structures may result in less material remaining elsewhere. We therefore measured exocuticle thickness at nine locations on Leucorrhinia dubia larvae from habitats with and without fish.

    3. Our results show a significant effect of the interaction between fish presence and spine length on head and fore leg exocuticle thickness. Relative thickness increased with relative length of lateral spine 9 in the absence of fish, whereas no such relationship existed with fish. Hence, synthesis and secretion of cuticle material occur as a trade-off when larvae react to fish presence.

    4. We assume the mechanism to be a selective synthesis of material with different responses in different parts of the larval body. These findings offer a new angle to the fish/spine trade off debate.

     

     

  • 37.
    Flenner, Ida
    et al.
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET), Bio- och miljösystemforskning (BLESS).
    Richter, Otto
    Technische Universität Braunschweig.
    Suhling, Frank
    Technische Universität Braunschweig.
    Rising temperature and development in dragonfly populations at different latitudes2010Inngår i: Freshwater Biology, ISSN 0046-5070, E-ISSN 1365-2427, Vol. 55, nr 2, s. 397-410Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    1. For modelling the future ecological responses to climate change, data on individual species and on variation within and between populations from different latitudes are required. 2. We examined life cycle regulation and growth responses to temperature in Mediter- ranean and temperate populations of a widespread European odonate, Orthetrum cancellatum. In an experiment, offspring from individual females from different parts of the range were kept separately to elucidate differences between families.

    3. The experiment was run outdoors at 52°N at a natural photoperiod for almost a year. We used four temperature regimes, ambient (i.e. following local air temperature) and ambient temperature increased by 2, 4 and 6 °C, to mimic future temperature rise. A mathematical model was used to categorise the type of seasonal regulation and estimate parameters of the temperature response curve.

    4. Growth rate varied significantly with temperature sum, survival and geographic origin, as well as with family. Offspring of all females from the temperate part of the range had a life cycle with a 12 h day-length threshold necessary to induce diapause (i.e. diapause was induced once day length fell below 12 h). By contrast, Mediterranean families had a 10 h threshold or had an unregulated life cycle allowing winter growth. The temperature response did not significantly differ between populations, but varied between families with a greater variation in the optimum temperature for growth in the Mediterranean population.

    5. The variation in seasonal regulation leads to a diversity in voltinism patterns within species, ranging from bivoltine to semivoltine along a latitudinal gradient. Given that the type of seasonal regulation is genetically fixed, rising temperatures will not allow faster than univoltine development in temperate populations. We discuss the consequences of our results in the light of rising temperature in central Europe.

     

  • 38.
    Flenner, Ida
    et al.
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET), Bio- och miljösystemforskning (BLESS).
    Sahlén, Göran
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET), Bio- och miljösystemforskning (BLESS).
    Dragonfly community re-organisation in boreal forest lakes: rapid species turnover driven by climate change?2008Inngår i: Insect Conservation and Diversity, ISSN 1752-458X, Vol. 1, nr 3, s. 169-179Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]
    1. Climate change affects many ecosystems on earth. If not dying out or migrating, the species affected have to survive the altered conditions, including changes in community structure. It is, however, usually difficult to distinguish changes caused by a changing climate from other factors.
    2. Forestry is considered to be the major disturbance factor in Swedish forests. Here, we use forest lake data sets from 1996 and 2006 which include species abundance data for dragonfly larvae, water plant structure, forest age and forestry measures during a period of 25 years: from 1980 to 2005. Hence, we were able to discriminate between forestry effects and changes in species composition driven by recent climate change.
    3. We explored effects on regional species composition, species abundance and ecosystem functions, such as changes in niche use, utilising dragonflies (Odonata) as model organisms.
    4. Our results show that dragonflies react rapidly to climate change, showing strong responses over such a short time span as 10 years. We observed changes in both species composition and abundance; former rare species have become more frequent and now occur in lakes of a wider quality range, while former widespread species have become more selective in their choice of waters. The new communities harbour about the same number of species as before, but seen from a regional perspective, diversity is reduced.
    5. We predict that the altered species composition and abundance might raise new demands in conservation planning as well as altering the ecological functions of the aquatic systems.
  • 39.
    Forsberg, Malin
    et al.
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET).
    Järlind, Joakim
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET).
    A study on the Construction and Ecological succession of two Small Artificial Reefs on the Swedish West Coast2014Independent thesis Basic level (degree of Bachelor), 15 poäng / 22,5 hpOppgave
    Abstract [en]

    Artificial reefs are being built in most parts of the world for a wide variety of purposes. Divingtourism is a common motivator for the construction of many reefs, particularly in the tropics,although the most widely used purpose is to improve or reconstruct hard bottom habitats andincrease the yield from fisheries. There are two main reasons for why aquatic life is attracted toartificial reefs. They provide excellent protection by often being hollow or filled with crevicesand cavities and increasing opportunities for improved foraging through accumulating biomassand extending the foraging range of an organism by acting like stepping stones. Sweden is acoastal country with few artificial reefs. In this study, two reefs were constructed in the sea offthe coast of Halmstad, Sweden to test small scale artificial reef production, marine organismcolonisation of the reefs during the first year, and to increase the local marine life diversity.Many marine organisms that would not normally occur in the sites where the reefs wereconstructed were observed, such as Symphodus melops and Anguilla anguilla. The reefs alsoprovided a new “clean slate” substrate for the settling of sessile organisms such as Urticina felinaor partially sessile organisms (i.e. during a certain stage of their life-cycle) such as some speciesof Cnidaria polyps. The tested method to construct these reefs was relatively cost effective for itspurpose. However a few minor but vital improvements, such as better binding materials, areneeded. Local marine life in the area has become more diverse during the experiment and thatalone is enough reason to motivate construction of similar reefs along the Swedish coast.

  • 40.
    Funes, Soledad
    et al.
    Institut für Physiologische Chemie, Ludwig-Maximilians-Universität München, Germany.
    Franzén, Lars-Gunnar
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET), Bio- och miljösystemforskning (BLESS), Växtcellbiologi: Energiomvandling i växtceller.
    González-Halphen, Diego
    Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, D.F., México.
    Chlamydomonas reinhardtii: the model of choice to study mitochondria from unicellular photosynthetic organisms.2007Inngår i: Methods in Molecular Biology, ISSN 1064-3745, Vol. 372, s. 137-149Artikkel i tidsskrift (Annet vitenskapelig)
    Abstract [en]

    Chlamydomonas reinhardtii is a model organism to study photosynthesis, cellular division, flagellar biogenesis, and, more recently, mitochondrial function. It has distinct advantages in comparison to higher plants because it is unicellular, haploid, and amenable to tetrad analysis, and its three genomes are subject to specific transformation. It also has the possibility to grow either photoautotrophically or heterotrophically on acetate, making the assembly of the photosynthetic machinery not essential for cell viability. Methods developed allow the isolation of C. reinhardtii mitochondria free of thylakoid contaminants. We review the general procedures used for the biochemical characterization of mitochondria from this green alga.

  • 41.
    Gaskell, George
    et al.
    Methodology Institute, London School of Economics, London, United Kingdom.
    Allum, Nick
    Methodology Institute, London School of Economics, London, United Kingdom.
    Stares, Sally
    Methodology Institute, London School of Economics, London, United Kingdom.
    Fjæstad, Björn
    Mid Sweden University, Östersund, Sweden.
    Öhman, Susanna
    Mid Sweden University, Östersund, Sweden.
    Olofsson, Anna
    Mid Sweden University, Östersund, Sweden.
    Europeans and biotechnology in 2002. Eurobarometer 58.0: A report to the EC Directorate General for Research from the project "Life Sciences in European Society"2003Rapport (Annet vitenskapelig)
    Abstract [en]

    This is the fifth in a series of Eurobarometer surveys on biotechnology and the life sciences. The surveys have been conducted in 1991, 1993, 1996, 1999 and in 2002. The survey is based on a representative sample of 16 500 respondents, approximately 1 000 in each EU member state (see report for exceptions). Survey design and analysis was conducted by an international research group ‘Life Sciences in European Society’ supported by DG Research. In a year when many European countries are involved in public discussions on aspects of biotechnology, this survey stands as a contribution to the informed debate.

  • 42.
    Graneli, Wilhelm
    et al.
    Limnology, Department of Ecology, Lund University, Lund, Sweden.
    Weisner, Stefan E.B.
    Limnology, Department of Ecology, Lund University, Lund, Sweden.
    Sytsma, Mark D.
    UC Davis, Department of Botany, Davis, United States.
    Rhizome dynamics and resource storage in Phragmites australis1992Inngår i: Wetlands Ecology and Management, ISSN 0923-4861, E-ISSN 1572-9834, Vol. 1, nr 4, s. 239-247Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Seasonal changes in rhizome concentrations of total nonstructural carbohydrates (TNC), water soluble carbohydrates (WSC), and mineral nutrients (N, P and K) were monitored in two Phragmites australis stands in southern Sweden. Rhizome biomass, rhizome length per unit ground area, and specific weight (weight/ length ratio) of the rhizomes were monitored in one of the stands. Rhizome biomass decreased during spring, increased during summer and decreased during winter. However, changes in spring and summer were small (< 500 g DW m-2) compared to the mean rhizome biomass (approximately 3000 g DW m-2). Winter losses were larger, approximately 1000 g DW m-2, and to a substantial extent involved structural biomass, indicating rhizome mortality. Seasonal changes in rhizome length per unit ground area revealed a rhizome mortality of about 30% during the winter period, and also indicated that an intensive period of formation of new rhizomes occurred in June. Rhizome concentrations of TNC and WSC decreased during the spring, when carbohydrates were translocated to support shoot growth. However, rhizome standing stock of TNC remained large (> 1000 g m-2). Concentrations and standing stocks of mineral nutrients decreased during spring/ early summer and increased during summer/ fall. Only N, however, showed a pattern consistent with a spring depletion caused by translocation to shoots. This pattern indicates sufficient root uptake of P and K to support spring growth, and supports other evidence that N is generally the limiting mineral nutrient for Phragmites. The biomass data, as well as increased rhizome specific weight and TNC concentrations, clearly suggests that "reloading" of rhizomes with energy reserves starts in June, not towards the end of the growing season as has been suggested previously. This resource allocation strategy of Phragmites has consequences for vegetation management. Our data indicate that carbohydrate reserves are much larger than needed to support spring growth. We propose that large stores are needed to ensure establishment of spring shoots when deep water or stochastic environmental events, such as high rhizome mortality in winter or loss of spring shoots due to late season frost, increase the demand for reserves. © 1992 SPB Academic Publishing.

  • 43.
    Gustafson, Emelie
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET).
    Kvalitet och kvantitet av älgfoder: en utvärdering av Skogsstyrelsens inventeringsmetod Fodpro i Hallands län2013Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Skogsstyrelsen har tagit fram underlag där de visar hur mycket ungskog det finns i alla älgförvaltningsområden i Sverige. Detta gör de genom analys av satellitbilder. Skogsstyrelsen använder mängden ungskog som ett mått på hur mycket foder det finns för älgarna. De påpekar att man bör komplettera med fältinventeringar för att få en mer rättvis bild av fodertillgången, men i 2012- och 2013 års foderprognoser ingår inte fältinventeringar i underlaget.

     Problemen med metoden är att utan fältinventeringar får man inte en rättvis bild av fodertillgången i ungskogen. Det är inte alla ungskogar som erbjuder bra föda för älgen, t.ex. ungskog med gran. Man kan även ifrågasätta att fodertillgången i övrig skogsmark inte bedöms.

     Genom vegetationsinventering i två områden i Halland, med hjälp av täckningsgrad i provytor, har tillgängligt älgfoder i ungskog och övrig mark undersökts. Syftet var att uppskatta fodertillgång i ungskog och jämföra denna med fodertillgång på övrig mark. Detta för att se om Skogsstyrelsens foderberäkningar ger en rättvis blid av fodertillgången.

     Resultaten visade att det finns mest foder i ungskogen för älgen men även att det finns en betydande del tillgängligt foder för älgen utanför ungskogen, främst i form av rönn, asp, sälg och ek (s.k. RASE) och i form av markris. Resultaten visade också att en femtedel av ungskogen består av gran vilket älgen inte gärna äter. Det visade sig också att stora variationer kan förekomma vad gäller täckningsgraden, dels mellan de två studieområdena och dels inom områdena och inom samma höjdklasser.

     Slutsatsen blir att fältinventeringar behövs för att komplettera skogsstyrelsens analyser av satellitbilder. Det finns ett behov av att korrigera för andelen gran i ungskogsarealen. Övrig mark borde också vägas in mer i bedömningen, detta fram för allt på grund av markris och begärliga arter som t.ex. RASE.

  • 44.
    Gustavsson, Oscar
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap.
    Increased Browning Alters Zooplankton Composition: A Mesocosm Study in Lake Bolmen2019Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    In the recent decades many freshwater systems in the northern hemisphere have been faced withan increase in water colour, a phenomenon called ‘’browning’’ or ‘’brownification’’.Planktonic communities have been observed to be affected by this ’’new’’ phenomenon. Anincrease in water colour can alter the light climate of aquatic systems and thus aquatic primaryproduction. Browning is predicted to increase along with climate change, and as planktoniccommunities have a key role in freshwater systems it has become crucial to study its impact. Amesocosm experiment was carried out in the summer of 2018 in lake Bolmen to study theeffects of predicted future browning (as in 50 and 100 years from present day conditions).Analysis showed that browning had a positive effect on the abundance of Daphnia spp.Furthermore, discriminant analysis revealed that expected browning in 100 years might causesignificant changes in taxonomic composition of zooplankton.

  • 45.
    Hansen, Emma
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET).
    Alternativ till obedövad kastrering av smågrisar: - Ur ett ekonomiskt och djurhälsomässigt perspektiv2010Independent thesis Basic level (degree of Bachelor), 15 poäng / 22,5 hpOppgave
    Abstract [en]

    This degree project aims to evaluate alternative methods to the unanaesthetized castration of piglets. Castration of piglets is performed to prevent the development of boar taint. Boar taint can cause great financial losses for the pig manufacturer. Unanaesthetized castration of piglets is not regarded to be satisfactory from an animal welfare perspective and the procedure will for that reason be outlawed in the near future.

    Several alternative methods are used in countries all over the world with promising result. The purpose of this study is to evaluate if this methods could be applied in Swedish pig production.

    A literature study has been combined with interviews; field studies, questionnaires and a small study on male pig production.

    To be applicable to and applied in Swedish pig production the alternative method must be financially accepted by the manufacturers but also accepted from an animal welfare perspective.

    Castration is the only way to guarantee a meat free of boar taint. Therefore the conclusion of this study is that the best result is achieved by a combination of anesthesia in combination with analgesia. This is the most inexpensive alternative which also causes the piglet the least amount of distress.

  • 46.
    Hansson, Jessica
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET), Bio- och miljösystemforskning (BLESS), Ekologi och miljövetenskap.
    Does the wolf (Canis lupus) affect presence of the red fox (Vulpes vulpes) in Sweden?2014Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Vargen (Canis lupus) har ökat stadigt i Sverige under de senaste decennierna. Vargens återkomst och dess påverkan på det svenska djurlivet studeras idag i stor utsträckning, och frågor har uppstått om vargen som toppredator kan komma att orsaka trofiska kaskader i ekosystemet, vilket har observerats i nationalparker i USA. Rödräven (Vulpes vulpes) har i Sverige visat sig dra stor nytta utav vargens återkomst genom den ökade mängden kadaver som vargen lämnar, vilket är en särskilt viktig födokälla under våren.

    Syftet med denna studie var att undersöka om närvaro av varg påverkar förekomst av rödräv. Rävspår räknades i 182 vilttrianglar i Örebro och Värmlands län under åren 2001-2003. Vilttrianglarna klassificerades med avseende på mängd jordbruksmark, avstånd till vargrevir och ålder på vargrevir. Effekt av varg på rävförekomst analyserades genom att jämföra rävspår med distans till vargrevir och hur länge det funnits varg i området samt rävspår i relation till mängd jordbruksmark. Studien kunde inte påvisa någon effekt av vargförekomst på räv.  Resultaten indikerar på att habitatet var nyckelfaktorn för rävförekomst istället för närvaro av varg. I och med att vargstammen ökar stadigt i Sverige är det dock av intresse med fortsatta studier i ämnet då vargen kan komma att spela en större roll i ekosystemet i framtiden.

  • 47.
    Hedman, Sofia
    et al.
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap.
    Jermer, Karin
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap.
    The LIFE GoodStream project in Trönninge:current and expected effects on amphibianpopulations and otter presence: in collaboration with LIFE GoodStream andHushållningssällskapet in Halland2019Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    LIFE GoodStream is an EU-financed conservation project, which strives to improve the ecologicalstatus of a stream in the agricultural landscape of Halland County, Sweden. Since 2015, the project hasconstructed amphibian ponds, restored wetlands, removed dispersal barriers and worked to return theTrönninge stream (Trönningeån) to more natural conditions. This study explores current and expectedeffects of these measures on populations of five species of amphibians (B. bufo, R. arvalis, R.temporaria, L. vulgaris, T. cristatus) and Eurasian otter Lutra lutra. Difference in amphibiancolonization of amphibian ponds and wetlands was explored through visual surveys. Otter presencewas investigated using standard survey method. All surveys took place in April 2019. Results showthat the wetlands have the highest presence of individual amphibians per meter shoreline, and thatotters are using the whole Trönningeån. While colonization and dispersal of amphibians to new habitatdepend on the ecology of the different species, our results emphasize appropriate hydroperiod andabsence of predators. That the top predator otter has returned to the ecosystem makes the future lookbright, even if otter presence itself does not necessarily mean that the ecological status of the streamhas improved. We would like to stress the difficulties in recreating natural conditions and ecosystems,and that it is always best to preserve natural systems when possible. Thanks to the measures ofGoodStream so far, these diverse semiaquatic species now have a chance to survive in the future, evenin the highly anthropogenic agricultural landscape of Trönninge.

  • 48.
    Hedström, Ingemar
    et al.
    Department of Applied Science, Mid Sweden University, Härnösand, Sweden & Escuela de Biología, Universidad de Costa Rica, San José, Costa Rica & Department of Ecumenical Research, Sabanilla, Costa Rica.
    Sahlén, Göran
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS). Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden.
    A key to the adult Costa Rican "helicopter" damselflies (Odonata Pseudostigmatidae) with notes on their phenology and life zone preferences2001Inngår i: Revista de biologia tropical, ISSN 0034-7744, E-ISSN 2215-2075, Vol. 49, nr 3-4, s. 1037-1056Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We present a key to the Costa Rican species of Pseudostigmatidae, comprising three genera with the following species: Megaloprepus caerulatus, Mecistogaster linearis, M. modesta, M. ornata and Pseudostigma aberrans. Pseudostigma accedens, which may occur in the region, is also included. For each species we give a brief account of morphology, phenology and life zone preferences, including distributional maps based on more than 270 records. These are not all of the known specimens from the area, but a high enough number to give a relatively good picture of the distribution and status of the species. We found M. caerulatus to be active during the first half of the year in seasonal, tropical semi-dry lowland forest and tropical moist forest at mid-elevation, but like M. linearis, M. caerulatus was active all year round in non-seasonal, tropical wet lowland forest and tropical moist forest at mid-elevation. Mecistogaster modesta also flew year round in non-seasonal, tropical wet lowland forest and tropical moist evergreen forest at mid-elevation, and likewise in seasonal and non-seasonal, tropical premontane moist forest. Only a few findings, however, have been made of M. modesta in seasonal, tropical semi-dry deciduous forest and seasonal, tropical moist evergreen forest. Mecistogaster ornata was missing entirely from non-seasonal, tropical wet lowland forest and non-seasonal, tropical moist forest at mid-elevation, while this species was active year round in seasonal, tropical dry lowland forest and tropical semi-dry forest, as well as in seasonal, tropical moist evergreen forest and tropical premontane moist forest, both at mid-elevation. Pseudostigma aberrans has so far been found too few times in Costa Rica for any indication of flight time preference.

  • 49.
    Hedström, Ingemar
    et al.
    Boston University, College of Arts and Sciences, Boston, MA, United States.
    Sahlén, Göran
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    An extended description of the larva of Megaloprepus caerulatus from Costa Rica (Odonata: Pseudostigmatidae)2003Inngår i: International Journal of Odonatology, ISSN 1388-7890, Vol. 6, nr 1, s. 23-31Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The larva of Megaloprepus caerulatus is described and illustrated from specimens collected near the northern border of Barbilla National Park on the Costa Rican Caribbean slope. Habits and characters of larvae of three different size classes obtained from artificial tree holes permit the identification of small (body length 4 mm, excluding the caudal lamellae) larvae up to the final stadium. New diagnostic characters include the shape of the prementum and head. © 2003 Taylor & Francis Group, LLC.

  • 50.
    Hedström, Ingemar
    et al.
    Boston University, Boston, USA.
    Sahlén, Göran
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Bio- och miljösystemforskning (BLESS).
    The dry season governs the reproduction of three pseudostigmatid zygopterans in Costa Rica: (Odonata Pseudostigmatidae)2007Inngår i: International Journal of Odonatology, ISSN 1388-7890, Vol. 10, nr 1, s. 53-63Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The large Neotropical zygopterans Megaloprepus caerulatus, Mecistogaster linearis and M. ornata (Pesudostigmatidae) were surveyed during five years, and striking differences in their reproduction patterns were shown: (1) At two study sites in seasonal, tropical semi-dry forests in Pacific Costa Rica, adult M. ornata could be observed throughout the year, occasionally during the dry season up to 24 indivi duals at one time. Larvae were found from the middle to the end of the wet season suggesting a generation time of one year. (2) At two other study sites in aseasonal tropical wet forest in Caribbean Costa Rica, adults of M. caerulatus were observed year round, often in rather low numbers. Larvae of this species as well as M. linearis appeared throughout the year. While dry periods and rainfall certainly are key factors in governing the reproductive patterns of these species in relation to the climatic regimes of their preferred life zones, it is also concluded that competition from other container dwellers, including tadpoles of poison arrow frogs, may be additional factors in explaining their seasonal variation. It is also argued that all three species seem to have a high plasticity in their life cycles and hence are able to adapt to local conditions rather than displaying the same behaviour throughout their range.

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