89 research outputs found
Searching for the light dark gauge boson in GeV-scale experiments
We study current constraints and search prospects for a GeV scale vector
boson at a range of low energy experiments. It couples to the Standard Model
charged particles with a strength <= 10^-3 to 10^-4 of that of the photon. The
possibility of such a particle mediating dark matter self-interactions has
received much attention recently. We consider searches at low energy high
luminosity colliders, meson decays, and fixed target experiments. Based on
available data, searches both at colliders and in meson decays can discover or
exclude such a scenario if the coupling strength is on the larger side. We
emphasize that a dedicated fixed target experiment has a much better potential
in searching for such a gauge boson, and outline the desired properties of such
an experiment. Two different optimal designs should be implemented to cover the
range of coupling strength 10^-3 to 10^-5, and < 10^-5 of the photon,
respectively. We also briefly comment on other possible ways of searching for
such a gauge boson.Comment: 33 pages, 5 figures; v2: corrected discussion of Upsilon decays,
updates to discussion of fixed-target experiments and QED constraints,
numerous minor changes, references added; v3: typo corrected relative to the
JHEP published versio
Private trade and monopoly structures : the East India Companies and the commodity trade to Europe in the eighteenth century
Our research is about the trade in material goods from Asia to Europe over this period, and its impact on Europe’s consumer and industrial cultures. It entails a comparative study of Europe’s East India Companies and the private trade from Asia over the period. The commodities trade was heavily dependent on private trade. The historiography to date has left a blind spot in this area, concentrating instead on corruption and malfeasance. Taking a global history approach we investigate the trade in specific consumer goods in many qualities and varieties that linked merchant communities and stimulated information flows. We set out how private trade functioned alongside and in connection with the various European East India companies; we investigate how this changed over time, how it drew on the Company infrastructure, and how it took the risks and developed new and niche markets for specific Asian commodities that the Companies could not sustain
Biochemical indices and life traits of loggerhead turtles (Caretta caretta) from Cape Verde Islands
The loggerhead turtle (Caretta caretta) is an endangered marine reptile for whom assessing population health requires
knowledge of demographic parameters such as individual growth rate. In Cape Verde, as within several populations, adult
female loggerhead sea turtles show a size-related behavioral and trophic dichotomy. While smaller females are associated
with oceanic habitats, larger females tend to feed in neritic habitats, which is reflected in their physiological condition and in
their offspring. The ratio of RNA/DNA provides a measure of cellular protein synthesis capacity, which varies depending on
changes in environmental conditions such as temperature and food availability. The purpose of this study was to evaluate
the combined use of morphometric data and biochemical indices as predictors of the physiological condition of the females
of distinct sizes and hatchlings during their nesting season and how temperature may influence the physiological condition
on the offspring. Here we employed biochemical indices based on nucleic acid derived indices (standardized RNA/DNA
ratio-sRD, RNA concentration and DNA concentration) in skin tissue as a potential predictor of recent growth rate in nesting
females and hatchling loggerhead turtles. Our major findings were that the physiological condition of all nesting females
(sRD) decreased during the nesting season, but that females associated with neritic habitats had a higher physiological
condition than females associated with oceanic habitats. In addition, the amount of time required for a hatchling to right
itself was negatively correlated with its physiological condition (sRD) and shaded nests produced hatchlings with lower sRD.
Overall, our results showed that nucleic acid concentrations and ratios of RNA to DNA are an important tool as potential
biomarkers of recent growth in marine turtles. Hence, as biochemical indices of instantaneous growth are likely
temperature-, size- and age-dependent, the utility and validation of these indices on marine turtles stocks deserves further
study.The authors thank the Cape Verde Ministry of Environment (General Direction for the Environment), INDP (National Fisheries Institution), the Canary
Islands Government (D.G. Africa and D.G. Research and Universities), ICCM (Canarian Institution for Marine Sciences), the Andalusian Government (Andalusian
Environmental Office) and AEGINA PROJECT (INTERREG IIIB) for funding and hosting them during this study. The authors also thank the European Regional
Development Fund (ERDF) through the COMPETE - Operational Competitiveness Programme, and national funds through FCT - PEst-C/MAR/LA0015/2011 for
supporting the biochemical analysis
Antibiotic research and development: business as usual?
This article contends that poor economic incentives are an important reason for the lack of new drugs and explains how the DRIVE-AB intends to change the landscape by harnessing the expertise, motivation and diversity of its partner
Influence of Milk-Feeding Type and Genetic Risk of Developing Coeliac Disease on Intestinal Microbiota of Infants: The PROFICEL Study
Interactions between environmental factors and predisposing genes could be involved in the development of coeliac disease (CD). This study has assessed whether milk-feeding type and HLA-genotype influence the intestinal microbiota composition of infants with a family history of CD. The study included 164 healthy newborns, with at least one first-degree relative with CD, classified according to their HLA-DQ genotype by PCR-SSP DQB1 and DQA1 typing. Faecal microbiota was analysed by quantitative PCR at 7 days, and at 1 and 4 months of age. Significant interactions between milk-feeding type and HLA-DQ genotype on bacterial numbers were not detected by applying a linear mixed-model analysis for repeated measures. In the whole population, breast-feeding promoted colonization of C. leptum group, B. longum and B. breve, while formula-feeding promoted that of Bacteroides fragilis group, C. coccoides-E. rectale group, E. coli and B. lactis. Moreover, increased numbers of B. fragilis group and Staphylococcus spp., and reduced numbers of Bifidobacterium spp. and B. longum were detected in infants with increased genetic risk of developing CD. Analyses within subgroups of either breast-fed or formula-fed infants indicated that in both cases increased risk of CD was associated with lower numbers of B. longum and/or Bifidobacterium spp. In addition, in breast-fed infants the increased genetic risk of developing CD was associated with increased C. leptum group numbers, while in formula-fed infants it was associated with increased Staphylococcus and B. fragilis group numbers. Overall, milk-feeding type in conjunction with HLA-DQ genotype play a role in establishing infants' gut microbiota; moreover, breast-feeding reduced the genotype-related differences in microbiota composition, which could partly explain the protective role attributed to breast milk in this disorder
Atlantic Leatherback Migratory Paths and Temporary Residence Areas
BACKGROUND: Sea turtles are long-distance migrants with considerable behavioural plasticity in terms of migratory patterns, habitat use and foraging sites within and among populations. However, for the most widely migrating turtle, the leatherback turtle Dermochelys coriacea, studies combining data from individuals of different populations are uncommon. Such studies are however critical to better understand intra- and inter-population variability and take it into account in the implementation of conservation strategies of this critically endangered species. Here, we investigated the movements and diving behaviour of 16 Atlantic leatherback turtles from three different nesting sites and one foraging site during their post-breeding migration to assess the potential determinants of intra- and inter-population variability in migratory patterns. METHODOLOGY/PRINCIPAL FINDINGS: Using satellite-derived behavioural and oceanographic data, we show that turtles used Temporary Residence Areas (TRAs) distributed all around the Atlantic Ocean: 9 in the neritic domain and 13 in the oceanic domain. These TRAs did not share a common oceanographic determinant but on the contrary were associated with mesoscale surface oceanographic features of different types (i.e., altimetric features and/or surface chlorophyll a concentration). Conversely, turtles exhibited relatively similar horizontal and vertical behaviours when in TRAs (i.e., slow swimming velocity/sinuous path/shallow dives) suggesting foraging activity in these productive regions. Migratory paths and TRAs distribution showed interesting similarities with the trajectories of passive satellite-tracked drifters, suggesting that the general dispersion pattern of adults from the nesting sites may reflect the extent of passive dispersion initially experienced by hatchlings. CONCLUSIONS/SIGNIFICANCE: Intra- and inter-population behavioural variability may therefore be linked with initial hatchling drift scenarios and be highly influenced by environmental conditions. This high degree of behavioural plasticity in Atlantic leatherback turtles makes species-targeted conservation strategies challenging and stresses the need for a larger dataset (>100 individuals) for providing general recommendations in terms of conservation
Global tracking of marine megafauna space use reveals how to achieve conservation targets
The recent Kunming-Montreal Global Biodiversity Framework (GBF) sets ambitious goals but no clear pathway for how zero loss of important biodiversity areas and halting human-induced extinction of threatened species will be achieved. We assembled a multi-taxa tracking dataset (11 million geopositions from 15,845 tracked individuals across 121 species) to provide a global assessment of space use of highly mobile marine megafauna, showing that 63% of the area that they cover is used 80% of the time as important migratory corridors or residence areas. The GBF 30% threshold (Target 3) will be insufficient for marine megafauna’s effective conservation, leaving important areas exposed to major anthropogenic threats. Coupling area protection with mitigation strategies (e.g., fishing regulation, wildlife-traffic separation) will be essential to reach international goals and conserve biodiversity
Reperfusion-induced apoptotic cell death involves ICE-like protease CPP32 in rat hearts in vivo
- …
