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- Unelius, C. Rikard, et al.
(författare)
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Identification and electrophysiological studies of (4S,5S)-5-hydroxy-4-methyl-3-heptanone and 4-methyl-3,5-heptanedione in male lucerne weevils
- 2013
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Ingår i: The Science of Nature. - : Springer Science and Business Media LLC. - 0028-1042 .- 1432-1904. ; 100:2, s. 135-143
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Tidskriftsartikel (refereegranskat)abstract
- An investigation to identify a sex or aggregation pheromone of Sitona discoideus GyllenhAyenl (Coleoptera: Curculionidae) is presented. Antenna flicking and attraction behaviors evoked by conspecifics of both sexes were recorded in arena bioassays, where attraction of females to males was observed. Air entrainment of both males and females was conducted in separate chambers. Gas chromatographic-mass spectrometric analysis of headspace volatiles revealed that two male-specific compounds, 4-methyl-3,5-heptanedione (major) and (4S,5S)-5-hydroxy-4-methyl-3-heptanone (minor), were emitted during the autumnal post-aestivatory flight period. The stereoisomers of the minor component were separated by enantioselective gas chromatography and their absolute configurations assigned by NMR (diastereomers) and the known preference of enantioselective transesterification reactions catalyzed by Candida antarctica lipase B. Electroantennogram and single sensillum recording studies indicate that 4-methyl-3,5-heptanedione as well as all individual stereoisomers of 5-hydroxy-4-methyl-3-heptanone are detected by the antennae of male and female S. discoideus. Further, single sensillum recordings suggest that both sexes of S. discoideus have specialized olfactory receptor neurons (ORNs) for detecting 4-methyl-3,5-heptanedione and different populations of stereoselective ORNs for detecting the stereoisomers of 5-hydroxy-4-methyl-3-heptanone. Some of these stereoselective ORNs appear to be sex-specific in S. discoideus.
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| 4. |
- Bohman, Björn, et al.
(författare)
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Structure Elucidation and Synthesis of Dioxolanes Emitted by Two Triatoma Species (Hemiptera Reduviidae)
- 2011
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Ingår i: Journal of natural products (Print). - : American Chemical Society (ACS). - 0163-3864 .- 1520-6025. ; 74:4, s. 690-694
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Tidskriftsartikel (refereegranskat)abstract
- Volatiles from the metastemal glands of two species Of true bugs of the Triatominae subfamily, Triatoma brasiliensis and Triatoma infestans, Were analyzed by SPME-GC/MS. Two sets of new natural products were found: (4S,5S)- and (4R,SR)-2,2,4-triethyl-5-methyl-1,3-dioxolane (1) (major component) and (45*,5S*)-2,4-diethyl-2,S-dimethyl-1,3-dioxolane (2) (trace component),-,(2R/S,4S,SS)- as well as (2R/S,4R,5R)-4-ethyl-5-methyl-2-(1-methylethyl)-1,3-dioxolane (3) (minor component), (2R/S,4S*,5S*).-4-ethyl-5-methyl-2-(1-methylpropyl)-1,3-dioxolane (4), (trace component), and (2R/S,4S*,5S*)-4-ethyl-5-methyl-2-(2-methylpropyl)-1,3-dioxolane (5) (trace component). Syntheses of optically active 1 and 3 were carried out by reacting pure,enantiomers of 2,3-pentanediol with 3-pentanone or 2-methylpropanal. The preparation of, pure 1 stereoisomers of 2,3-pentanediol involved a novel key step for the synthesis of secondary alcohols: the reduction of a carboxylic ester by means of DIBAH and in situ alkylation of the intermediate by Grignard reaction at low temperature Starting from the pure enantiomers of methyl lactate; all four stereoisoniers of 2,3-pentanediol were synthesized. and transformed, to the corresponding isomers of 1 and 2. Relative configurations of the natural products and enantiomeric compositions of naturally occurring 1 and :2 were determined by comparison of their mass spectra and gas chromatographic retention times (co-injection) I with those of authentic reference samples.
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| 5. |
- Gustafsson, Markus, 1982-, et al.
(författare)
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Challenges of conducting experimental studies within a clinical nursing context
- 2014
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Ingår i: Applied Nursing Research. - : Elsevier. - 0897-1897 .- 1532-8201. ; 27:2, s. 133-136
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Tidskriftsartikel (refereegranskat)abstract
- In recent years, several distinguished scholars have advocated for nursing research that may carry strong evidence for practice. Their advocacy have highlighted that nursing science has reached a point where as nurse researchers we need to develop the questions we ask and design studies that have the power to produce solid, translational, evidence-based knowledge. To do so, we need to carry out experimental tests on complex, everyday nursing interventions and activities. We also need to create public space to present accounts of our endeavours pursuing this type of design in clinical practice. This paper will discuss some of the most important insights gained from conducting a quasi-experimental study in which the aim was to investigate the effect of a theory-based intervention, targeting knowledge and attitudes among registered nurses regarding cancer pain management. The importance of careful practical and methodological planning is emphasised and the need for participation-friendly interventions is discussed.
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| 6. |
- Sparrenbom, Charlotte, et al.
(författare)
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Kommunernas avloppshantering bara liten del av problemet
- 2014
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Ingår i: Dagens Nyheter. - 1101-2447.
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- Slutreplik. Per-Åke Sahlberg skriver engagerat om att det finns mer än jordbruk som påverkar vattenkvalitet. Han har helt rätt. Eftersom vatten ständigt är i rörelse och helt gränsöverskridande kommer alla aktiviteter som sker att påverka vattenkvaliteten – såväl antropogena som naturliga. Men prioriteringar av var insatserna måste ske görs sällan. Att påstå att avloppshanteringen är det största problemet är att förenkla och snedvrida bilden av vad som påverkar vår dricksvattenkvalitet, skriver en grupp forskare och experter.
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| 7. |
- Sparrenbom, Charlotte, et al.
(författare)
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Sverige måste bli bättre på att kontrollera dricksvattnet
- 2014
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Ingår i: Dagens Nyheter. - 1101-2447.
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- Styvmoderligt behandlat område. Undersökningar visar att vart tredje svenskt grundvattenprov är förorenat av växtskyddsmedel. Ändå övervakas bara fjorton procent av de svenska grundvattenförekomsterna. Sverige måste agera nu för att få kontroll över situationen, skriver nio forskare och experter.
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| 8. |
- Stenroth, Karolina, et al.
(författare)
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A model-based comparison of organic matter dynamics in forested and open-canopy streams
- 2014
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Ingår i: Riparian Ecology and Conservation. - : Portico. - 2299-1042. ; 2:1
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Tidskriftsartikel (refereegranskat)abstract
- The food webs of forest streams are primarily based upon inputs of organic matter from adjacent terrestrial ecosystems. However, streams that run through open landscapes generally lack closed riparian canopies, and an increasing number of studies indicate that terrestrial organic matter may be an important resource in these systems as well. Combining key abiotically-controlled factors (stream discharge, water temperature, and litter input rate) with relevant biotic processes (e.g. macroinvertebrate CPOM consumption, microbial processing), we constructed a model to predict and contrast organic matter dynamics (including temporal variation in CPOM standing crop, CPOM processing rate, FPOM production, and detritivore biomass) in small riparian-forested and open-canopy streams. Our modeled results showed that the standing crop of CPOM was similar between riparian-forested and open-canopy streams, despite considerable differences in litter input rate. This unexpected result was partly due to linkages between CPOM supply and consumer abundance that produced higher detritivore biomass in the forest stream than the open-canopy stream. CPOM standing crop in the forest stream was mainly regulated by top-down consumer control, depressing it to a level similar to that of the open-canopy stream. In contrast, CPOM standing crop in the open-canopy stream was primarily controlled by physical factors (litter input rates and discharge), not consumption. This suggests that abiotic processes (e.g. discharge) may play a greater role in limiting detrital resource availability and consumer biomass in open-canopy streams than in forest streams. These model results give insight on functional differences that exists among streams and they can be used to predict effects of anthropogenic influences such as forestry, agriculture, urbanization, and climate change on streams and how riparian management and conservation tools can be employed to mitigate undesirable effects.
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