231 research outputs found
Laboratory and tentative interstellar detection of trans-methyl formate using the publicly available Green Bank Telescope PRIMOS survey
The rotational spectrum of the higher-energy trans conformational isomer of
methyl formate has been assigned for the first time using several pulsed-jet
Fourier transform microwave spectrometers in the 6-60 GHz frequency range. This
species has also been sought toward the Sagittarius B2(N) molecular cloud using
the publicly available PRIMOS survey from the Green Bank Telescope. We detect
seven absorption features in the survey that coincide with laboratory
transitions of trans-methyl formate, from which we derive a column density of
3.1 (+2.6, -1.2) \times 10^13 cm-2 and a rotational temperature of 7.6 \pm 1.5
K. This excitation temperature is significantly lower than that of the more
stable cis conformer in the same source but is consistent with that of other
complex molecular species recently detected in Sgr B2(N). The difference in the
rotational temperatures of the two conformers suggests that they have different
spatial distributions in this source. As the abundance of trans-methyl formate
is far higher than would be expected if the cis and trans conformers are in
thermodynamic equilibrium, processes that could preferentially form
trans-methyl formate in this region are discussed. We also discuss measurements
that could be performed to make this detection more certain. This manuscript
demonstrates how publicly available broadband radio astronomical surveys of
chemically rich molecular clouds can be used in conjunction with laboratory
rotational spectroscopy to search for new molecules in the interstellar medium.Comment: 40 pages, 7 figures, 4 tables; accepted for publication in Ap
High COVID-19 transmission potential associated with re-opening universities can be mitigated with layered interventions
Reopening of universities to students following COVID-19 restrictions risks increased transmission due to high numbers of social contacts and the potential for asymptomatic transmission. Here, the authors use a mathematical model with social contact data to estimate the impacts of reopening a typical non-campus based university in the UK
Quality target negotiation in health care : evidence from the English NHS
We examine how public sector third-party purchasers and hospitals negotiate quality targets when a fixed proportion of hospital revenue is required to be linked to quality. We develop a bargaining model linking the number of quality targets to purchaser and hospital characteristics. Using data extracted from 153 contracts for acute hospital services in England in 2010/11, we find that the number of quality targets is associated with the purchaser’s population health and its budget, the hospital type, whether the purchaser delegated negotiation to an agency, and the quality targets imposed by the supervising regional health authority
Examining the Evidence for Chytridiomycosis in Threatened Amphibian Species
Extinction risks are increasing for amphibians due to rising threats and minimal conservation efforts. Nearly one quarter of all threatened/extinct amphibians in the IUCN Red List is purportedly at risk from the disease chytridiomycosis. However, a closer look at the data reveals that Batrachochytrium dendrobatidis (the causal agent) has been identified and confirmed to cause clinical disease in only 14% of these species. Primary literature surveys confirm these findings; ruling out major discrepancies between Red List assessments and real-time science. Despite widespread interest in chytridiomycosis, little progress has been made between assessment years to acquire evidence for the role of chytridiomycosis in species-specific amphibian declines. Instead, assessment teams invoke the precautionary principle when listing chytridiomycosis as a threat. Precaution is valuable when dealing with the world's most threatened taxa, however scientific research is needed to distinguish between real and predicted threats in order to better prioritize conservation efforts. Fast paced, cost effective, in situ research to confirm or rule out chytridiomycosis in species currently hypothesized to be threatened by the disease would be a step in the right direction. Ultimately, determining the manner in which amphibian conservation resources are utilized is a conversation for the greater conservation community that we hope to stimulate here
Values of natural and human-made wetlands: A meta-analysis
The values of goods and services provided by wetland ecosystems are examined through a meta-analysis of an expanded database of wetland value estimates and with a focus on human-made wetlands. This study extends and improves upon previous meta-analyses of the wetland valuation literature in terms of the number of observations, geographical coverage, wetland class and integrity, and the measurement of the effects of scarcity and anthropogenic pressure. We find that water quality improvement, nonconsumptive recreation, and provision of natural habitat and biodiversity are highly valued services. Substitution effects are observed through the negative correlation between values and abundance of other wetlands. Wetland values are found to increase with anthropogenic pressure. An extended metaregression model with cross effects shows that the valuation of specific services varies with the type of wetland producing them. Human-made wetlands are highly valued for biodiversity enhancement, water quality improvement, and flood control
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BioTIME: A database of biodiversity time series for the Anthropocene.
MotivationThe BioTIME database contains raw data on species identities and abundances in ecological assemblages through time. These data enable users to calculate temporal trends in biodiversity within and amongst assemblages using a broad range of metrics. BioTIME is being developed as a community-led open-source database of biodiversity time series. Our goal is to accelerate and facilitate quantitative analysis of temporal patterns of biodiversity in the Anthropocene.Main types of variables includedThe database contains 8,777,413 species abundance records, from assemblages consistently sampled for a minimum of 2 years, which need not necessarily be consecutive. In addition, the database contains metadata relating to sampling methodology and contextual information about each record.Spatial location and grainBioTIME is a global database of 547,161 unique sampling locations spanning the marine, freshwater and terrestrial realms. Grain size varies across datasets from 0.0000000158 km2 (158 cm2) to 100 km2 (1,000,000,000,000 cm2).Time period and grainBioTIME records span from 1874 to 2016. The minimal temporal grain across all datasets in BioTIME is a year.Major taxa and level of measurementBioTIME includes data from 44,440 species across the plant and animal kingdoms, ranging from plants, plankton and terrestrial invertebrates to small and large vertebrates.Software format.csv and .SQL
Avoiding Costly Conservation Mistakes: The Importance of Defining Actions and Costs in Spatial Priority Setting
Background: The typical mandate in conservation planning is to identify areas that represent biodiversity targets within the smallest possible area of land or sea, despite the fact that area may be a poor surrogate for the cost of many conservation actions. It is also common for priorities for conservation investment to be identified without regard to the particular conservation action that will be implemented. This demonstrates inadequate problem specification and may lead to inefficiency: the cost of alternative conservation actions can differ throughout a landscape, and may result in dissimilar conservation priorities
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