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991.
992.
Migration strategies and annual space‐use in an Afro‐Palaearctic aerial insectivore – the European nightjar Caprimulgus europaeus 下载免费PDF全文
Obligate insectivorous birds breeding in high latitudes travel thousands of kilometres during annual movements to track the local seasonal peaks of food abundance in a continuously fluctuating resource landscape. Avian migrants use an array of strategies when conducting these movements depending on e.g. morphology, life history traits and environmental factors encountered en route. Here we used geolocators to derive data on the annual space‐use, temporal pattern and migratory strategies in an Afro‐Palaearctic aerial insectivorous bird species – the European nightjar Caprimulgus europaeus. More specifically, we aimed to test a set of hypothesises pertaining to the migration of a population of nightjars breeding in south‐eastern Sweden. We found that the birds wintered across the central and western parts of the southern tropical Africa almost entirely outside the currently described wintering range of the species. The nightjars performed a narrow loop migration across Sahara, with spring Sahel stopovers significantly to the west of autumn stops indicative to an adaptive response to winds during migration. To our surprise, the migration speed was faster in the autumn (119 km d? 1) than in the spring (99 km d? 1), possibly due to the prevailing wind regimes over the Sahara. The estimated flight fraction in both autumn (14%) and spring (12%) was almost exactly as the theoretically predicted 1:7 time relationship between flights and stopovers for small birds. The temporal patterns within the annual cycle indicate that individuals follow alternative spatiotemporal schedules that converge towards the breeding season. The positive relationship between the spatially and temporally distant winter departure and breeding arrival suggests that individuals´ temporal fine‐tuning to breeding may be constrained, leading to potential negative fitness consequences. 相似文献
993.
Magnetic compass orientation research with migratory songbirds at Stensoffa Ecological Field Station in southern Sweden: why is it so difficult to obtain seasonally appropriate orientation? 下载免费PDF全文
Rachel Muheim Susanne Åkesson Johan Bäckman Sissel Sjöberg 《Journal of avian biology》2017,48(1):6-18
More than three decades ago, Thomas Alerstam initiated the study of orientation and navigation of migratory songbirds in southern Sweden. Stensoffa Ecological Field Station, located approx. 20 km east of Lund, has since been a primary location for orientation experiments. However, it has often been difficult to record well‐oriented behaviour in the seasonal appropriate migratory directions, in particular in magnetic orientation experiments under simulated overcast or indoors. Here, we summarise all available experiments testing magnetic compass orientation in migratory songbirds in southern Sweden, and review possible explanations for the poor magnetic compass orientation found in many studies. Most of the factors proposed can be essentially excluded, such as difficulties to extract magnetic compass information at high latitudes, methodological or experimenter biases, holding duration and repeated testing of individual birds, effects of magnetic anomalies and temporal variations of the ambient magnetic field, as well as anthropogenic electromagnetic disturbances. Possibly, the geographic location of southern Sweden where many birds captured and/or tested at coastal sites are confronted with the sea, might explain some of the variation that we see in the orientation behaviour of birds. Still, further investigations are needed to conclusively identify the factors responsible for why birds are not better oriented in the seasonal appropriate migratory direction at Stensoffa. 相似文献
994.
Rolf Frischknecht Enrico Benetto Thomas Dandres Reinout Heijungs Charlotte Roux Dieuwertje Schrijvers Gregor Wernet Yi Yang Annika Messmer Laura Tschuemperlin 《The International Journal of Life Cycle Assessment》2017,22(2):296-301
The 62nd life cycle assessment (LCA) forum was held on 9 September 2016 to discuss the state of research and application with regard to consequential life cycle assessment. This conference report presents the highlights of the LCA forum. The state of the art of consequential LCA was presented from different viewpoints. It was pointed out that consequential LCA is more than marginal mixes and avoided burdens and involves causal modelling. It was also said that social responsibility calls for consequential LCA. Currently, different models are used to support decision making. It was suggested to make use of the variety of models to check the conclusiveness of their results and thus the reliability of the LCAs. Current and future implementations of consequential LCI models in background databases and linking algorithms were presented. Several speakers presented consequential LCA case studies covering the sectors energy, transport, housing and mining. Some of the LCA models used in the case studies are complemented with general and partial computable equilibrium models and agent-based models and use environmentally extended input-output data or process-based LCA data. Some of the presentations focused on elements such as constrained production, marginal market mixes and technologies or recycling and system expansion. In three parallel workshops, the needs, contents and methodology, and implementation of consequential LCA approaches were discussed. The participants seemed to generally agree on the basic goal that LCA should be able to reflect the consequences of decisions. The inquiry among the participants showed that the demand for consequential LCA studies is hardly existent. The appropriate implementation of consequential modelling in LCA databases and on the appropriate model to be used in consequential LCA case studies was debated. It revealed a need for further and extensive discussions to be able to reach (minimum) consensus. 相似文献
995.
Anna Rising Ella Cederlund Carina Palmberg Henrik Uhlhorn Stefan Gaunitz Kerstin Nordling Erik Ågren Elisabet Ihse Gunilla T. Westermark Lars Tjernberg Hans Jörnvall Jan Johansson Per Westermark 《Protein science : a publication of the Protein Society》2017,26(11):2312-2318
Amyloid A (AA) amyloidosis occurs spontaneously in many mammals and birds, but the prevalence varies considerably among different species, and even among subgroups of the same species. The Blue fox and the Gray fox seem to be resistant to the development of AA amyloidosis, while Island foxes have a high prevalence of the disease. Herein, we report on the identification of AA amyloidosis in the Red fox (Vulpes vulpes). Edman degradation and tandem MS analysis of proteolyzed amyloid protein revealed that the amyloid partly was composed of full‐length SAA. Its amino acid sequence was determined and found to consist of 111 amino acid residues. Based on inter‐species sequence comparisons we found four residue exchanges (Ser31, Lys63, Leu71, Lys72) between the Red and Blue fox SAAs. Lys63 seems unique to the Red fox SAA. We found no obvious explanation to how these exchanges might correlate with the reported differences in SAA amyloidogenicity. Furthermore, in contrast to fibrils from many other mammalian species, the isolated amyloid fibrils from Red fox did not seed AA amyloidosis in a mouse model. 相似文献
996.
Annika M. Felton Adam Felton Joris P. G. M. Cromsigt Lars Edenius Jonas Malmsten Hilde Karine Wam 《Acta theriologica》2017,62(1):1-7
People provide wild ungulates with large quantities of supplementary feed to improve their health and survival and reduce forest damage. Whereas supplementary feeding can positively affect the winter survival of ungulates and short-term hunting success, some of the feeds provided may actually reduce ungulate health and increase forest damage. Here, we highlight how recent advances in ungulate nutritional ecology can help explain why supplementary feeding can lead to undesirable outcomes. Using Europe’s largest cervid, the moose (Alces alces), as a model species, and Sweden, as the socio-ecological context, we explain the concept of nutritional balancing and its relevance to supplementary feeding. Nutritional balancing refers to how animals alter their food intake to achieve a specific nutritional target balance in their diet, by selecting balanced food items or by combining items with nutritional compositions that are complimentary. As the most common supplementary feeds used contain higher concentrations of non-structural carbohydrates than the ungulates’ normal winter diet, the consumption of such feeds may cause animals to increase their intake of woody browse, and thereby exacerbate forest damage. We also explain how animal health may be negatively affected by large intakes of such feed if complementary browse items are not available. We therefore suggest that the use of inappropriate feed is an additional means by which supplementary feeding may result in negative outcomes for hunters, forest owners, and wild animals. 相似文献
997.
Emma Norrman Max Petzold Mika Gissler Anne Lrke Spangmose Signe Opdahl Anna-Karina Henningsen Anja Pinborg Aila Tiitinen Annika Rosengren Liv Bente Romundstad Ulla-Britt Wennerholm Christina Bergh 《PLoS medicine》2021,18(9)
BackgroundSome earlier studies have found indications of significant changes in cardiometabolic risk factors in children born after assisted reproductive technology (ART). Most of these studies are based on small cohorts with high risk of selection bias. In this study, we compared the risk of cardiovascular disease, obesity, and type 2 diabetes between singleton children born after ART and singleton children born after spontaneous conception (SC).Methods and findingsThis was a large population-based cohort study of individuals born in Norway, Sweden, Finland, and Denmark between 1984 and 2015. Data were obtained from national ART and medical birth registers and cross-linked with data from national patient registers and other population-based registers in the respective countries. In total, 122,429 children born after ART and 7,574,685 children born after SC were included. Mean (SD) maternal age was 33.9 (4.3) years for ART and 29.7 (5.2) for SC, 67.7% versus 41.8% were primiparous, and 45.2% versus 32.1% had more than 12 years of education. Preterm birth (<37 weeks 0 days) occurred in 7.9% of children born after ART and 4.8% in children born after SC, and 5.7% versus 3.3% had a low birth weight (<2,500 g). Mean (SD) follow-up time was 8.6 (6.2) years for children born after ART and 14.0 (8.6) years for children born after SC. In total, 135 (0.11%), 645 (0.65%), and 18 (0.01%) children born after ART were diagnosed with cardiovascular disease (ischemic heart disease, cardiomyopathy, heart failure, or cerebrovascular disease), obesity or type 2 diabetes, respectively. The corresponding values were 10,702 (0.14%), 30,308 (0.74%), and 2,919 (0.04%) for children born after SC. In the unadjusted analysis, children born after ART had a significantly higher risk of any cardiovascular disease (hazard ratio [HR] 1.24; 95% CI 1.04–1.48; p = 0.02), obesity (HR 1.13; 95% CI 1.05–1.23; p = 0.002), and type 2 diabetes (HR 1.71; 95% CI 1.08–2.73; p = 0.02). After adjustment, there was no significant difference between children born after ART and children born after SC for any cardiovascular disease (adjusted HR [aHR]1.02; 95% CI 0.86–1.22; p = 0.80) or type 2 diabetes (aHR 1.31; 95% CI 0.82–2.09; p = 0.25). For any cardiovascular disease, the 95% CI was reasonably narrow, excluding effects of a substantial magnitude, while the 95% CI for type 2 diabetes was wide, not excluding clinically meaningful effects. For obesity, there was a small but significant increased risk among children born after ART (aHR 1.14; 95% CI 1.06–1.23; p = 0.001). Important limitations of the study were the relatively short follow-up time, the limited number of events for some outcomes, and that the outcome obesity is often not considered as a disease and therefore not caught by registers, likely leading to an underestimation of obesity in both children born after ART and children born after SC.ConclusionsIn this study, we observed no difference in the risk of cardiovascular disease or type 2 diabetes between children born after ART and children born after SC. For obesity, there was a small but significant increased risk for children born after ART.Trial registration numberISRCTN11780826.Emma Norrman and co-workers study the health of children born with and without assisted reproductive technology. 相似文献
998.
Schoug A Fischer J Heipieper HJ Schnürer J Håkansson S 《Journal of industrial microbiology & biotechnology》2008,35(3):175-181
During the industrial stabilization process, lactic acid bacteria are subjected to several stressful conditions. Tolerance
to dehydration differs among lactic acid bacteria and the determining factors remain largely unknown. Lactobacillus coryniformis Si3 prevents spoilage by mold due to production of acids and specific antifungal compounds. This strain could be added as
a biopreservative in feed systems, e.g. silage. We studied the survival of Lb. coryniformis Si3 after freeze-drying in a 10% skim milk and 5% sucrose formulation following different fermentation pH values and temperatures.
Initially, a response surface methodology was employed to optimize final cell density and growth rate. At optimal pH and temperature
(pH 5.5 and 34 °C), the freeze-drying survival of Lb. coryniformis Si3 was 67% (±6%). The influence of temperature or pH stress in late logarithmic phase was dependent upon the nature of the
stress applied. Heat stress (42 °C) did not influence freeze-drying survival, whereas mild cold- (26 °C), base- (pH 6.5),
and acid- (pH 4.5) stress significantly reduced survival. Freeze-drying survival rates varied fourfold, with the lowest survival
following mild cold stress (26 °C) prior to freeze-drying and the highest survival after optimal growth or after mild heat
(42 °C) stress. Levels of different membrane fatty acids were analyzed to determine the adaptive response in this strain.
Fatty acids changed with altered fermentation conditions and the degree of membrane lipid saturation decreased when the cells
were subjected to stress. This study shows the importance of selecting appropriate fermentation conditions to maximize freeze-drying
viability of Lb. coryniformis as well as the effects of various unfavorable conditions during growth on freeze-drying survival. 相似文献
999.
Katharina Metzner Tilman Gross Annika Balzulat Gesine Wack Ruirui Lu Achim Schmidtko 《Purinergic signalling》2021,17(3):503
Previous studies suggest that adenosine A1 receptors (A1R) modulate the processing of pain. The aim of this study was to characterize the distribution of A1R in nociceptive tissues and to evaluate whether targeting A1R with the partial agonist capadenoson may reduce neuropathic pain in mice. The cellular distribution of A1R in dorsal root ganglia (DRG) and the spinal cord was analyzed using fluorescent in situ hybridization. In behavioral experiments, neuropathic pain was induced by spared nerve injury or intraperitoneal injection of paclitaxel, and tactile hypersensitivities were determined using a dynamic plantar aesthesiometer. Whole-cell patch-clamp recordings were performed to assess electrophysiological properties of dissociated DRG neurons. We found A1R to be expressed in populations of DRG neurons and dorsal horn neurons involved in the processing of pain. However, administration of capadenoson at established in vivo doses (0.03–1.0 mg/kg) did not alter mechanical hypersensitivity in the spared nerve injury and paclitaxel models of neuropathic pain, whereas the standard analgesic pregabalin significantly inhibited the pain behavior. Moreover, capadenoson failed to affect potassium currents in DRG neurons, in contrast to a full A1R agonist. Despite expression of A1R in nociceptive neurons, our data do not support the hypothesis that pharmacological intervention with partial A1R agonists might be a valuable approach for the treatment of neuropathic pain. 相似文献
1000.
Mamat U Meredith TC Aggarwal P Kühl A Kirchhoff P Lindner B Hanuszkiewicz A Sun J Holst O Woodard RW 《Molecular microbiology》2008,67(3):633-648
The Escherichia coli K-12 strain KPM22, defective in synthesis of 3-deoxy-d-manno-oct-2-ulosonic acid (Kdo), is viable with an outer membrane (OM) composed predominantly of lipid IV(A), a precursor of lipopolysaccharide (LPS) biosynthesis that lacks any glycosylation. To sustain viability, the presence of a second-site suppressor was proposed for transport of lipid IV(A) from the inner membrane (IM), thus relieving toxic side-effects of lipid IV(A) accumulation and providing sufficient amounts of LPS precursors to support OM biogenesis. We now report the identification of an arginine to cysteine substitution at position 134 of the conserved IM protein YhjD in KPM22 that acts as a compensatory suppressor mutation of the lethal DeltaKdo phenotype. Further, the yhjD400 suppressor allele renders the LPS transporter MsbA dispensable for lipid IV(A) transmembrane trafficking. The independent derivation of a series of non-conditional KPM22-like mutants from the Kdo-dependent parent strain TCM15 revealed a second class of suppressor mutations localized to MsbA. Proline to serine substitutions at either residue 18 or 50 of MsbA relieved the Kdo growth dependence observed in the isogenic wild-type strain. The possible impact of these suppressor mutations on structure and function are discussed by means of a computationally derived threading model of MsbA. 相似文献