| 1. |
- Andersson, Magnus, et al.
(författare)
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Fiskbestånd och miljö i hav och sötvatten : Resurs- och miljööversikt 2012
- 2012
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Detta är den nionde utgåvan av den samlade översikten över fisk- och kräftdjursbeståndens status i våra vatten. Kunskap om fiskbestånden och miljön är en förutsättning för att utnyttjandet av fiskresurserna skall bli bärkraftigt. För svenska vattenområden beskrivs miljöutvecklingen i ett ekosystemsperspektiv, dels för att tydliggöra fiskens ekologiska roll och beskriva yttre miljöfaktorer som påverkar fiskbestånden, dels för att belysa fiskets effekter på miljön.Fiskbestånd och miljö i hav och sötvatten är utarbetad av Sveriges lantbruksuniversitet (SLU), Institutionen för akvatiska resurser (SLU Aqua), på uppdrag av Havs- och vattenmyndigheten. Rapporten sammanfattar utveckling och beståndsstatus för de kommersiellt viktigaste fisk- och kräftdjursarterna i våra vatten. Bedömningar och förvaltningsråd är baserade på Internationella Havsforskningsrådets (ICES) rådgivning, SLU Aquas nationella och regionala provfiskedata, samt yrkesfiskets rapportering.
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| 2. |
- Handlin, Linda
(författare)
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Human-Human and Human-Animal Interaction : Some Common Physiological and Psychological Effects
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The aim of the present thesis was to investigate hormonal and physiological effects in mothers during a breastfeeding session and in dogs and their owners in response to short-term interaction. In study one, sixty-six mothers receiving either exogenous oxytocin infusion and/or epidural analgesia (EDA) during labor or intramuscular oxytocin injection post partum were studied. Oxytocin, prolactin, adrenocorticotrophic hormone (ACTH) and cortisol levels, as well as blood pressure were measured during a breastfeeding session two days after birth. In response to breastfeeding two days after birth, the mothers displayed a pulsatile release of oxytocin and increasing prolactin levels. In addition, the activity in the HPA-axis was reduced and maternal blood pressure decreased. The results also show that EDA administration in combination with oxytocin during labor resulted insignificantly lower oxytocin levels and higher cortisol levels, as well as higher bloodpressure in response to breastfeeding two days after birth, compared to EDA administration alone. In addition, oxytocin infusions dose-dependently lowered the mothers’ endogenous oxytocin levels two days after birth. In study two, ten female dog owners and their male Labrador dogs participated, together with ten controls. Their levels of oxytocin, cortisol and insulin, as well as their heart rate, were measured. The connection between the quality of the dogowner relationship and hormone levels was also explored. Short-term interaction between dogs and their owners resulted in oxytocin release in both species and their cortisol levels and heart rate were also affected. Oxytocin levels and positive attitudes regarding the dog-owner relationship were positively correlated. In conclusion, both human-human and human-animal interactions induce oxytocin release and promote oxytocin mediated effects, such as decreasing cortisol levels and blood pressure. In addition, social interaction and oxytocin levels arepositively related.
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| 5. |
- Ovegård, Maria, et al.
(författare)
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Cormorant predation effects on fish populations: A global meta-analysis
- 2021
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Ingår i: Fish and Fisheries. - : Wiley. - 1467-2960 .- 1467-2979. ; 22, s. 605-622
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Tidskriftsartikel (refereegranskat)abstract
- This paper provides the results from the first meta-analysis to examine the impact of cormorant (Phalacrocoracidae) predation on fish. It is based on a systematic search of literature, covering studies using significance-based hypotheses tests on the relation between fish parameters and cormorant abundance. The results show that extensive research on cormorant diet exists, but few studies use statistical hypotheses testing to examine the effect on fish populations. In total, 603 publications were identified from titles and abstracts, to include the interaction between cormorants and fish. From these, 27 articles tested fish population parameters against cormorant predation, whereof 22 could be included in analyses. The effect size was defined negative in cases when cormorant numbers or presence reduced fish numbers or biomasses, or when individual fish sizes decreased, and vice versa for a positive effect. In a hierarchical dependence model, the combined effect of cormorant predation on fish was negative, but the overall effect was not significant at the 95% confidence level (-0.169, 95% C.L. -0.505 to 0.167, p = .256, df = 5.26). A covariate analysis revealed a difference in predatory effects between fish prey taxa (p = .006, df = 5.73), but no difference in effect sizes between study type, foraging habitat, or response variable measured. The meta-analysis reveals a complex interaction between cormorants and fish, but adds to the consensus on the importance of considering cormorant predatory effects in research, conservation actions, ecosystem-based management, and environmental monitoring.
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| 6. |
- Petersson, Maria, et al.
(författare)
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Ageing of two petroleum waxes
- 2008
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Ingår i: Journal of Materials Science. - : Springer Science and Business Media LLC. - 0022-2461 .- 1573-4803. ; 43:6, s. 1859-1868
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Tidskriftsartikel (refereegranskat)abstract
- The effect of ageing at different storage conditions on the microstructure and melting properties of two petroleum waxes, petrolatum and microcrystalline wax, were investigated. The two waxes were stored for a maximum of 50 weeks at different temperatures. Samples were analysed before storage and removed from storage and analysed after different storage times. The effect of storage time and temperature was analysed with confocal laser scanning microscopy and modulated differential scanning calorimetry. Some alteration in the microstructure occurred with longer storage time. The amount of fine and irregular structures seen in the initial petrolatum samples decreased with storage time, and some shadowy, grey areas appeared. The microstructure of the microcrystalline wax stored at 23 °C became more diffuse and more, shadowy, grey areas appeared with time compared to samples stored at 50 °C. These showed coarser crystalline structures and fewer shadowy, grey areas. The results of confocal laser scanning microscopy and modulated differential scanning calorimetry analyses indicated that recrystallization occurred in both waxes during storage. The proposed recrystallization processes taking place during storage were most likely the same in all samples, but the recrystallization occurred to a greater extent in the microcrystalline wax samples stored at 50 °C.
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| 7. |
- Petersson, Maria, et al.
(författare)
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Comparison of microstructural and physical properties of two petroleum waxes
- 2008
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Ingår i: Journal of Materials Science. - : Springer Science and Business Media LLC. - 0022-2461 .- 1573-4803. ; 43:6, s. 1869-1879
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Tidskriftsartikel (refereegranskat)abstract
- Microstructural and physical properties of two petroleum waxes, petrolatum and microcrystalline wax, were characterized in this work. Petroleum waxes are known to be hydrophobic and can be used in applications where a good moisture barrier is needed. In order to achieve a better understanding of different inherent properties of a wax, the two waxes in this work were characterized with infrared spectroscopy, confocal laser scanning microscopy, differential scanning calorimetry, rheology and X-ray diffraction. It was concluded from the results of infrared spectroscopy that the two waxes consisted only of saturated alkanes. Confocal laser scanning microscopy showed that the petrolatum sample had a more open microstructure with coarse crystals separated from each other than the microcrystalline wax, which appeared to have a more network-like crystalline structure consisting of somewhat finer crystals. Both waxes crystallized over a broad temperature range. Their crystallization characteristics were quite different, however, probably owing to a different oil content. According to modulated differential scanning calorimetry and rheological measurements the microcrystalline wax crystallized through a two-step process, whereas the petrolatum crystallized through only one step.
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| 9. |
- Petersson, Maria, et al.
(författare)
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Oxytocin and Cortisol Levels in Dog Owners and Their Dogs Are Associated with Behavioral Patterns : An Exploratory Study
- 2017
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Ingår i: Frontiers in Psychology. - : Frontiers Media S.A.. - 1664-1078. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- We have previously shown that dog–owner interaction results in increasing oxytocin levels in owners and dogs, decreasing cortisol levels in owners but increasing cortisol levels in dogs. The present study aimed to further investigate whether oxytocin and cortisol levels in the previously tested owners and dogs were associated with their behaviors during the interaction experiment. Ten female volunteer dog–owners and their male Labrador dogs participated in a 60 min interaction experiment with interaction taking place during 0–3 min and blood samples for analysis of oxytocin and cortisol were collected at 0, 1, 3, 5, 15, 30, and 60 min. The entire experiment was videotaped and the following variables were noted; the different types (stroking, scratching, patting and activating touch, i.e., scratching and patting combined) as well as the frequency of touch applied by the owner, the number of times the owner touched her dog, the dog’s positions and time spent in each position. Correlations were analyzed between the behavioral variables and basal oxytocin levels, maximum oxytocin levels, delta oxytocin levels, basal cortisol levels and cortisol levels at 15 min. Owners with low oxytocin levels before and during the interaction touched their dogs more frequently (0 min: Rs = −0.683, p = 0.042; oxytocin maximum: Rs = −0.783, p = 0.013). The lower the dogs’ oxytocin levels during the interaction, the more stroking they received (Rs = −0.717, p = 0.041). The more frequently activating touch was applied by the owner, the higher the dogs’ cortisol levels became (15 min: Rs = 0.661, p = 0.038). The higher the owners’ maximum oxytocin level the fewer position changes the dogs made (Rs = −0.817, p = 0.007) and the shorter time they spent sitting (Rs = −0.786, p = 0.036), whereas the higher the owners’ basal cortisol levels, the longer time the dogs spent standing (0 min: Rs = 0.683, p = 0.041). In conclusion, oxytocin and cortisol levels, both in dogs and in their owners, are associated with the way the owners interact with their dogs and also with behaviors caused by the interaction.
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