JSNS
2
(J-PARC Sterile Neutrino Search at J-PARC Spallation Neutron Source) is an experiment that searches for sterile neutrinos via the observation of
ν
¯
μ
→
ν
¯
e
appearance oscillations using ...muon decay-at-rest neutrinos. The JSNS
2
experiment performed data taking from 2021. In this manuscript, a study of the accidental background is presented. The rate of the accidental background is (
9.29
±
0.39
)
×
10
-
8
/spill with 0.75 MW beam power and comparable to the expected number of signal events.
Abstract
Recent European environmental policies argue for the development of indicators of the ecological status of ecosystems that are easy to implement and powerful enough to detect changes ...quickly. For instance, some indicators that are currently proposed for monitoring foodweb structure and functioning are based on the size of organisms, using size as a proxy for trophic level. However, these indicators do not necessarily accurately reflect the underlying trophic structure and dynamics to follow. Ecological tracers (i.e. chemical parameters measured in consumer tissues to infer the trophic ecology of organisms) may serve as complementary indicators of trophic level, and may also help distinguish different populations of a species when more commonly used methods (e.g. genetic, age determination) present their own limitations. Here, we analysed the potential of muscle δ13C and δ15N values and of muscle mercury (Hg) concentrations to depict size-related trophic habits of different fish species. We expected that intra- and interspecific variation in these ecological tracers could be helpful in refining currently proposed indicators of marine ecosystems, and also help in discriminating management unitsfor some species. Four fish species were selected for their economical and/or ecological importance in the Bay of Biscay (Northeast Atlantic): whiting Merlangius merlangus, European hake Merluccius merluccius, Atlantic horse mackerel Trachurus trachurus and anglerfish Lophius piscatorius. Muscle δ13C and δ15N values segregated the species and enabled us to discriminate species-specific feeding strategies with increasing size of individuals. Fish body size was not always linearly correlated with δ15N or trophic level. In contrast, Hg concentrations and size-related Hg patterns were more similar from species to species. Interestingly, muscle δ15N values together with Hg concentrations segregated the two putative stocks of European hake within the Bay of Biscay. Hence, we propose the combined use of ecological tracers as a promising method for accurately assigning a consumer to a trophic guild, investigating Hg trophodynamics in foodwebs, and helping discriminate distinct ecological populations within a species when defining management units.
The disappearance of reactor antineutrinos in the Double Chooz experiment is used to investigate the possibility of neutrino–antineutrino oscillations arising due to the breakdown of Lorentz ...invariance. We find no evidence for this phenomenon and set the first limits on 15 coefficients describing neutrino–antineutrino mixing within the framework of the Standard-Model Extension.
Although deep-sea cephalopods are key marine organims, their feeding ecology remains essentially unknown. Here, we report for the first time the trophic structure of an assemblage of these animals ...(19 species) by measuring the isotopic signature of wings of their lower beaks, which accumulated in stomachs of stranded sperm whales. Overall, the species encompassed a narrow range in δ13C values (1.7‰), indicating that they lived in closely related and overlapping habitats. δ13C values can be interpreted in terms of distribution with the more 13C-depleted species (e.g. Stigmatoteuthis arcturi, Vampyroteuthis infernalis) having a more pelagic habitat than the more 13C-enriched, bathyal species (e.g. Todarodes sagittatus and the giant squid Architeuthis dux). The cephalopods sampled had δ15N values ranging 4.6‰, which is consistent with the species spanning approximately 1.5 trophic levels. Neither the giant octopod (Haliphron atlanticus) nor the giant squid reached the highest trophic position. Species δ15N was independent of body size, with large squids having both the highest (Taningia danae) and lowest (Lepidoteuthis grimaldii) δ15N values. Their trophic position indicates that some species share the top of the food web, together with other megacarnivores such as the sperm whale.
Fisheries bycatch is considered to be one of the most significant causes of mortality for many marine species, including vulnerable megafauna. In the open ocean, tuna purse seiners are known to use ...several cetacean species to detect tuna schools. This exposes the cetaceans to encirclement which can lead to incidental injury or death. While interactions between fishers and cetaceans have been well documented in the eastern tropical Pacific Ocean, little is known about these interactions and potential mortalities in the tropical Atlantic and Indian Oceans. Here, we provide the first quantification of these interactions in both oceans by analyzing a large database of captain’s logbooks (1980 to 2011) and observations collected by onboard scientific observers (1995 to 2011). Distribution maps of sightings per unit effort highlighted main areas of relatively high co-occurrence: east of the Seychelles (December to March), the Mozambique Channel (April to May) and the offshore waters of Gabon (April to September). The percentage of cetacean-associated fishing sets was around 3% in both oceans and datasets whereas 0.6% of sets had cetaceans encircled. Of the 194 cetaceans encircled in a purse seine net (122 baleen whales, 72 delphinids), immediate apparent survival rates were high (Atlantic: 92%, Indian: 100%). Among recorded mortalities, 8 involved pantropical spotted dolphins Stenella attenuata and 3 involved humpback whales Megaptera novaeangliae. These high survival rates suggest that setting nets close to cetaceans has a low immediate apparent impact on the species involved. Our findings will contribute to the development of an ecosystem approach to managing fisheries and accurate cetacean conservation measures.
Monitoring the health status of marine mammals is a priority theme that France aims to develop with the other European Union Member States in the next two years, in the context of the Marine Strategy ...Framework Directive. With approximately 5,000 km of coastline and for nearly ten years, France has been recording an average of 2,000 strandings per year, which are monitored by the National Stranding Network, managed by Pelagis, the observatory for the conservation of marine mammals from La Rochelle University and the French National Center for Scientific Research. Since 1972, this network has successively evolved from spatial and temporal faunistic description to, nowadays, the detection of major causes of mortality. It now aims to carry out epidemiological studies on a population scale. Thus, a strategy to strengthen the monitoring of marine mammals’ health status based on stranding data has been developed. This strategy will allow for a more accurate detection of anthropogenic cause of death as well as those of natural origin. It will allow the monitoring of time trends and geographical differences of diseases associated with conservation and public health issues while ensuring the early detection of emerging and/or zoonotic diseases of importance. It will also allow a better assessment of the consequences of human activities on these animal populations and on the environment. Thus, this strategy is fully in line with the “One Health” approach which implies an integrated vision of public, animal and environmental health. It is broken down into four surveillance modalities: (1) general event-based surveillance (GES); (2) programmed surveillance (PS); (3) specific event-based surveillance (SES); (4) and in the longer term, syndromic surveillance (SyS). This article describes the French strategy as well as these different surveillance modalities, the levels of examinations and the associated sampling protocols and finally, the method of standardisation of the data collected. The objective is to present the strategy developed at the French level in order to integrate it into a future strategy shared at the European level to standardise practices and especially complementary analysis, necessary for a better evaluation of the health status of these mobile marine species.
The role of vitamin D on bone microarchitecture and fragility is not clear.
To investigate whether vitamin D deficiency (25(OH)D <20 ng/mL) increases cortical bone loss and the severity of fractures.
...Cross-sectional study of 287 elderly women with at least one prevalent low-impact fracture.
Biochemistry, X-rays to identify vertebral fractures (VFs) and to confirm non-vertebral fractures (NonVFs), and high-resolution peripheral quantitative computed tomography (HR-pQCT) to evaluate bone microstructure.
Serum 25(OH)D levels were associated with body mass index (BMI: r = -0.161, P = 0.006), PTH (r = -0.165; P = 0.005), CTX (r = -0.119; P = 0.043) and vBMD at cortical bone (Dcomp: r = 0.132; P = 0.033) and entire bone (D100: r = 0.162 P = 0.009) at the distal radius, but not at the tibia. Age and PTH levels were potential confounding variables, but in the multiple linear regressions only BMI (95% CI: 0.11-4.16; P < 0.01), 25(OH)D (95% CI: -0.007 to 1.70; P = 0.05) and CTX (95% CI: -149.04 to 21.80; P < 0.01) predicted Dcomp, while BMI (95% CI: 1.13-4.18; P < 0.01) and 25(OH)D (95% CI: 0.24-1.52; P < 0.01) predicted D100. NonVFs predominated in patients with 25(OH)D <20 ng/mL (P = 0.013). Logistic regression analysis showed a decrease in the likelihood of presenting grade 2-3 VFs/NonVFs for every increase in 25(OH)D (OR = 0.962, 95% CI: 0.940-0.984; P = 0.001), BMI (OR = 0.932, 95% CI: 0.885-0.981; P = 0.007) and D100 at radius (OR = 0.994, 95% CI: 0.990-0.998; P = 0.005).
In elderly patients with prevalent fractures, vitamin D deficiency was associated with cortical bone loss and severity of fractures.
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