19,893 research outputs found
Coordination and Conflict: The Persistent Relevance of Networks in International Financial Regulation
This thesis presents SiGe(C)/Si(C) multi quantum well (MQW) layers individually or in combination with Si(C) Schottky diodes as material structures to detect infrared (IR) radiation. The performance of devices was investigated in terms of SiGe/Si periodicity and quality of SiGe/Si interface. The structures were grown by chemical vapour deposition using GeH4 and SiH4 sources at 650 °C and processed into pixel arrays with sizes of 25×25, 100×100 and 200×200 μm2. The device response to thermal variations was expressed by temperature coefficient of resistance (TCR) and the signal-to-noise-ratio was evaluated by noise measurements. The strain relaxation in SiGe layers was investigated by implementing oxygen at the interface of SiGe/Si or during SiGe growth. A minor amount of 10 ppb oxygen at the interface can be detected by noise measurements while the material characterizations could reveal defects for significantly higher defect density. Oxygen and water contaminations should be accounted for in low temperature epitaxy (350-650 °C) of the layers. Furthermore, an empirical model was developed to describe the kinetics of the SiGe growth using Si2H6 and Ge2H6 as precursors at low temperature. The model takes into account the energy for dissociation of gas molecules, diffusion of the molecules from the gas boundaries toward the substrate and the incorporation of absorbed molecules. A good consistency was observed between the experimental and calculated data.QC 20150211</p
A saturated genetic linkage map of autotetraploid alfalfa (Medicago sativa L.) developed using genotyping-by-sequencing is highly syntenous with the Medicago truncatula genome.
A genetic linkage map is a valuable tool for quantitative trait locus mapping, map-based gene cloning, comparative mapping, and whole-genome assembly. Alfalfa, one of the most important forage crops in the world, is autotetraploid, allogamous, and highly heterozygous, characteristics that have impeded the construction of a high-density linkage map using traditional genetic marker systems. Using genotyping-by-sequencing (GBS), we constructed low-cost, reasonably high-density linkage maps for both maternal and paternal parental genomes of an autotetraploid alfalfa F1 population. The resulting maps contain 3591 single-nucleotide polymorphism markers on 64 linkage groups across both parents, with an average density of one marker per 1.5 and 1.0 cM for the maternal and paternal haplotype maps, respectively. Chromosome assignments were made based on homology of markers to the M. truncatula genome. Four linkage groups representing the four haplotypes of each alfalfa chromosome were assigned to each of the eight Medicago chromosomes in both the maternal and paternal parents. The alfalfa linkage groups were highly syntenous with M. truncatula, and clearly identified the known translocation between Chromosomes 4 and 8. In addition, a small inversion on Chromosome 1 was identified between M. truncatula and M. sativa. GBS enabled us to develop a saturated linkage map for alfalfa that greatly improved genome coverage relative to previous maps and that will facilitate investigation of genome structure. GBS could be used in breeding populations to accelerate molecular breeding in alfalfa
Nephropathia epidemica and Puumala virus occurrence in relation to bank vole (Clethrionomys glareolus) dynamics and environmental factors in northern Sweden
The objectives of the thesis were to investigate the spatio-temporal patterns of nephropathia epidemica (NE) in humans and Puumala virus (PUU) occurrence in relation to bank vole (Clethrionomys glareolus) dynamics and environmental factors in a region of high incidence of NE in northern Sweden. Nephropathia epidemica is a mild form of hemorrhagic fever with renal syndrome, and in northern Sweden the most prevailing serious febrile viral infection, second to influenza. All serologically confirmed NE cases during 1991-2001 in the four northernmost counties (n = 2,468) were used to establish spatio-temporal patterns of the occurrence of the human disease. Within the study region, the bank voles show marked population fluctuations with 3-4 yr cycles and the incidence of NE has a temporal component strongly correlated to annual numbers of bank voles in autumn. People living in rural dwellings near coastal areas were abundant among notified cases and middle-aged males were over-represented. The patients were often infected in autumn when engaged in activities such as handling of fire wood, gardening or hay-handling near man-made rodent refugia or cleaning/redecorating within one. A proportion of these patients, confident about site of PUU exposure, were used to establish field sites in two separate studies. Firstly a five year study (1995-1999) at six sites spanning a bank vole population cycle, and secondly a spatially extensive study at 32 sites was conducted in autumn 1998. Densities, fluctuations and demography of vole populations differ between sites of known occurrence of NE were compared to random forest sites. Five years of repeated biannual sampling revealed that case sites harbored more bank voles than random forest sites, in particular during population peaks. For the individual bank voles, the probability of PUU infection was significantly higher in population peak year, increased with age and was higher for males than for females. In the spatially extended study, it was found that in particular environmental characteristics associated with old-growth moist forests (i.e. Alectoria spp., Picea abies, fallen wood and Vaccinium myrtillus) were associated with high bank vole numbers and numbers of PUU infected bank voles. This implies that success in circulation and persistence of PUU within local bank vole populations is strongly influenced by the local environments. In future modeling of PUU transmission, influence of bank vole demography and environmental factors should be useful on establishing risk assessments and identifying areas of particular risk of PUU exposure
Storage oil hydrolysis during early seedling growth
Storage oil breakdown plays an important role in the life cycle of many plants by providing the carbon skeletons that support seedling growth immediately following germination. This metabolic process is initiated by lipases (EC: 3.1.1.3), which catalyze the hydrolysis of triacylglycerols (TAGs) to release free fatty acids and glycerol. A number of lipases have been purified to near homogeneity from seed tissues and analysed for their in vitro activities. Furthermore, several genes encoding lipases have been cloned and characterised from plants. However, only recently has data been presented to establish the molecular identity of a lipase that has been shown to be required for TAG breakdown in seeds. In this review we briefly outline the processes of TAG synthesis and breakdown. We then discuss some of the biochemical literature on seed lipases and describe the cloning and characterisation of a lipase called SUGAR-DEPENDENT1, which is required for TAG breakdown in Arabidopsis thaliana seeds
A theory for the retrieval of virtual temperature from winds, radiances and the equations of fluid dynamics
A technique to deduce the virtual temperature from the combined use of the equations of fluid dynamics, observed wind and observed radiances is described. The wind information could come from ground-based sensitivity very high frequency (VHF) Doppler radars and/or from space-borne Doppler lidars. The radiometers are also assumed to be either space-borne and/or ground-based. From traditional radiometric techniques the vertical structure of the temperature can be estimated only crudely. While it has been known for quite some time that the virtual temperature could be deduced from wind information only, such techniques had to assume the infallibility of certain diagnostic relations. The proposed technique is an extension of the Gal-Chen technique. It is assumed that due to modeling uncertainties the equations of fluid dynamics are satisfied only in the least square sense. The retrieved temperature, however, is constrained to reproduce the observed radiances. It is shown that the combined use of the three sources of information (wind, radiances and fluid dynamical equations) can result in a unique determination of the vertical temperature structure with spatial and temporal resolution comparable to that of the observed wind
Reducing cross-sucking of group housed calves by an environmental enriched building design
Group housing is a natural and economic way of raising calves. One major disadvan-tage of group housing calves is the occurrence of cross-sucking as an abnormal behaviour. The main objective of our study on organic calf housing was the reduction of cross-sucking related to milk feeding. A new feeding stall with automatic gates was attached to an automatic teat feeder. One gate opened to an enriched area immedi-ately when the calves had finished their milk meal. In this zone calves could use rub-ber teats or a hay net (treatment optimized). The design for the control group used a simple feeding stall without attached enriched zone. 168 female calves (German Holstein) from one origin (herd) were randomly assigned to 14 groups with 12 calves each. Thus, each treatment could be repeated seven times. Two groups were used for preliminary testing of housing and technique. Calves were fed whole milk, according to EU-organic-farming-guidelines. The behaviour of calves was observed directly for 20 minutes following milk intake. In addition, 24 hour video observation completed the behavioural monitoring. The videos were analyzed with the continuous sampling method; statistical analysis was done with the SAS statistical software package and non-parametric procedures. As one result, cross-sucking of calves decreased signifi-cantly in the optimized housing treatment compared to the control treatment: cross-sucking behaviour occurred for 12% of the calves of the optimized treatment vs. 60% cross-sucking calves in the control treatment. Regarding the intensity of cross-sucking, the control group showed 200 cross-sucking bouts per 100 calves and meal, in comparison with a frequency of 16 bouts of the optimized treatment. Our study supports the thesis, that design of housing and environment could be used to reduce cross-sucking of group housed calves. However, future research should be done to evaluate interactions between feeding techniques, environment and physiological processes related to cross-sucking behaviour of calves
Selection Mapping Identifies Loci Underpinning Autumn Dormancy in Alfalfa (Medicago sativa).
Autumn dormancy in alfalfa (Medicago sativa) is associated with agronomically important traits including regrowth rate, maturity, and winter survival. Historical recurrent selection experiments have been able to manipulate the dormancy response. We hypothesized that artificial selection for dormancy phenotypes in these experiments had altered allele frequencies of dormancy-related genes. Here, we follow this hypothesis and analyze allele frequency changes using genome-wide polymorphisms in the pre- and postselection populations from one historical selection experiment. We screened the nondormant cultivar CUF 101 and populations developed by three cycles of recurrent phenotypic selection for taller and shorter plants in autumn with markers derived from genotyping-by-sequencing (GBS). We validated the robustness of our GBS-derived allele frequency estimates using an empirical approach. Our results suggest that selection mapping is a powerful means of identifying genomic regions associated with traits, and that it can be exploited to provide regions on which to focus further mapping and cloning projects
Use of Propolis chemical and Asian tiger mosquito bites : case report and review
Propolis is a substance of variable composition which incorporates resins derived from plants and beeswax. It varies depending on the geographic location and local flora such as plant and bee species. Propolis possesses several attributes such as immune enhancement, antimicrobial, antioxidant, analgesic as well as reported anti-tumour effects.1,2 Several research efforts have focused on studying the chemical composition of propolis.3-7 The diverse biological activity probably relates in part to the significant changes in extract constituents. Propolis has been popularized in the past as a natural remedy but significant possible pharmaceutical use is envisaged. This brief review details a case of how multiple annoying localized allergic skin reactions secondary to Asian tiger mosquito bites were soothed and resolved very rapidly with the application of Propolis.peer-reviewe
Calcification depth of deep-dwelling planktonic foraminifera from the eastern North Atlantic constrained by stable oxygen isotope ratios of shells from stratified plankton tows
Stable oxygen isotopes (delta O-18) of planktonic foraminifera are one of the most used tools to reconstruct environmental conditions of the water column. Since different species live and calcify at different depths in the water column, the delta O-18 of sedimentary foraminifera reflects to a large degree the vertical habitat and interspecies delta O-18 differences and can thus potentially provide information on the vertical structure of the water column. However, to fully unlock the potential of foraminifera as recorders of past surface water properties, it is necessary to understand how and under what conditions the environmental signal is incorporated into the calcite shells of individual species. Deep-dwelling species play a particularly important role in this context since their calcification depth reaches below the surface mixed layer. Here we report delta O-18 measurements made on four deep-dwelling Globorotalia species collected with stratified plankton tows in the eastern North Atlantic. Size and crust effects on the delta O-18 signal were evaluated showing that a larger size increases the delta O-18 of G. inflata and G. hirsuta, and a crust effect is reflected in a higher delta O-18 signal in G. truncatulinoides. The great majority of the delta O-18 values can be explained without invoking disequilibrium calcification. When interpreted in this way the data imply depth-integrated calcification with progressive addition of calcite with depth to about 300m for G. inflata and to about 500m for G. hirsuta. In G. scitula, despite a strong subsurface maximum in abundance, the vertical delta O-18 profile is flat and appears dominated by a surface layer signal. In G. truncatulinoides, the delta O-18 profile follows equilibrium for each depth, implying a constant habitat during growth at each depth layer. The delta O-18 values are more consistent with the predictions of the Shackleton (1974) palaeotemperature equation, except in G. scitula which shows values more consistent with the Kim and O'Neil (1997) prediction. In all cases, we observe a difference between the level where most of the specimens were present and the depth where most of their shell appears to calcify.Agência financiadora Portuguese Foundation for Science and Technology (FCT): SFRH/BD/78016/2011;
UID/Multi/04326/2019
European Union Seventh Framework Programme (FP7/2007-2013): 228344-EUROFLEETS
German Research Foundation (DFG): WA2175/2-1; WA2175/4-1
German Climate Modelling consortium PalMod - German Federal Ministry of Education and Research (BMBF)info:eu-repo/semantics/publishedVersio
Two-Buck Chuck and Wine Quality: Hedonic Price Analysis of Cool Climate Wines
Demand and Price Analysis,
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