715 research outputs found
The two-loop five-particle amplitude in supergravity
We compute for the first time the two-loop five-particle amplitude in
supergravity. Starting from the known integrand, we perform an
integration-by-parts reduction and express the answer in terms of uniform
weight master integrals. The latter are known to evaluate to non-planar
pentagon functions, described by a 31-letter symbol alphabet. We express the
final result for the amplitude in terms of uniform weight four symbols,
multiplied by a small set of rational factors. The amplitude satisfies the
expected factorization properties when one external graviton becomes soft, and
when two external gravitons become collinear. We verify that the soft
divergences of the amplitude exponentiate, and extract the finite remainder
function. The latter depends on fewer rational factors, and is independent of
one of the symbol letters. By analyzing identities involving rational factors
and symbols we find a remarkably compact representation in terms of a single
seed function, summed over all permutations of external particles. Finally, we
work out the multi-Regge limit, and present explicitly the leading logarithmic
terms in the limit. The full symbol of the IR-subtracted hard function is
provided as an ancillary file.Comment: 22 pages, 1 figure, 8 ancillary file
Species and gender differentiation between and among domestic and wild animals using mitochondrial and sex-linked DNA markers
In many African countries accurate and reliable identification of poached wildlife products like carcasses or meat presents a big problem when morphological characters such as skin hair or bones are missing. We describe a molecular based approach that has a potential of serving as a forensic tool in game meat identification in Africa. A mitochondial DNA marker (mt700) and one restriction enzyme, Rsa1 were used in the PCR-RFLP species identification of game meat obtained from two National Parks in Tanzania. Species-specific reference DNA fragment patterns were obtained using fresh meat from ten wildlife and four domesticated species. All species except the zebra, produced unique monomorphic RFLP patterns. Collectively, these patterns demonstrate the potential ability of genetic techniques for discriminating between and among wildlife and domestic species. The reference PCR-RFLP fragments enabled species identification of about 79% of unknown meat samples. In addition, sex was alsoassigned to all of the samples following successful amplification of gender-specific, SRY and ZFY/X, chromosomal domains. Although the present study has been conducted on a limited range both in numbers and genetic diversity of wildlife species present in Africa, the results demonstrate thepotential usefulness of the DNA approach in wildlife forensics in the continent
The potential of mitochondrial DNA markers and polymerase chain reaction-restriction fragment length polymorphism for domestic and wild species identification
Poaching is increasingly presenting challenge to conservational authorities in Africa. Accurate and reliable methods for the identification of poached wildlife meat when morphological features aremissing, has been lacking in Africa. We describe a molecular based approach that has a potential of serving as a tool for game and domestic meat identification in Africa. A mitochondrial (mt246) markerand Rsa1 restriction enzyme were used in the PCR-RFLP species identification of game and domestic meat. Species-specific reference DNA fragment patterns were obtained using fresh meat from ten majorwild herbivores, representing the highly targeted wild meat species in Tanzania and four domesticated animal species. With the exception of the zebra, all species produced unique monomorphic RFLPpatterns that were species specific. These reference fragment patterns enabled identification of about 75% of unknown meat samples, demonstrating the ability of the technique in discriminating betweenand among wild and domestic species. The results provide preliminary promising fingerprints which need further validation for future use for the control of the up-surging bush meat trade in the continent
All master integrals for three-jet production at NNLO
We evaluate analytically all previously unknown nonplanar master integrals
for massless five-particle scattering at two loops, using the differential
equations method. A canonical form of the differential equations is obtained by
identifying integrals with constant leading singularities, in space-time
dimensions. These integrals evaluate to -linear combinations of
multiple polylogarithms of uniform weight at each order in the expansion in the
dimensional regularization parameter, and are in agreement with previous
conjectures for nonplanar pentagon functions. Our results provide the complete
set of two-loop Feynman integrals for any massless scattering process,
thereby opening up a new level of precision collider phenomenology.Comment: 6 pages, 1 figure, 5 ancillary files; v2: references added; full
boundary values in s12 physical region included; v3: values of the master
integrals in the ancillary files update
On the characterisation of a Bragg spectrometer with X-rays from an ECR source
Narrow X-ray lines from helium-like argon emitted from a dedicated ECR source
have been used to determine the response function of a Bragg crystal
spectrometer equipped with large area spherically bent silicon (111) or quartz
(10) crystals. The measured spectra are compared with simulated ones
created by a ray-tracing code based on the expected theoretical crystal's
rocking curve and the geometry of the experimental set-up.Comment: Version acceptee (NIM
The biogeography of the caribou lungworm, Varestrongylus eleguneniensis (Nematoda: Protostrongylidae) across northern North America
Varestrongylus eleguneniensis (Nematoda; Protostrongylidae) is a recently described species of lungworm that infects caribou (Rangifer tarandus), muskoxen (Ovibos moschatus) and moose (Alces americanus) across northern North America. Herein we explore the geographic distribution of V. eleguneniensis through geographically extensive sampling and discuss the biogeography of this multi-host parasite. We analyzed fecal samples of three caribou subspecies (n = 1485), two muskox subspecies (n = 159), and two moose subspecies (n = 264) from across northern North America. Protostrongylid dorsal-spined larvae (DSL) were found in 23.8%, 73.6%, and 4.2% of these ungulates, respectively. A portion of recovered DSL were identified by genetic analyses of the ITS-2 region of the nuclear rDNA or the cytochrome oxidase c subunit I (COI) region of the mtDNA. We found V. eleguneniensis widely distributed among caribou and muskox populations across most of their geographic prange in North America but it was rare in moose. Parelaphostrongylus andersoni was present in caribou and moose and we provide new geographic records for this species. This study provides a substantial expansion of the knowledge defining the current distribution and biogeography of protostrongylid nematodes in northern ungulates. Insights about the host and geographic range of V. eleguneniensis can serve as a geographically extensive baseline for monitoring current distribution and in anticipating future biogeographic scenarios under a regime of accelerating climate and anthropogenic perturbation
Optimal Structure and Dissolution of Partnerships
We derive the optimal incentive compatible and individually rational mechanisms to reallocate arbitrary given ownership shares among a set of agents. These mechanisms are optimal in the sense that they maximize social surplus of the final allocation subject to the aforementioned constraints and a revenue constraint. We allow for the agents' types to be drawn from non-identical distributions and for interdependent values. Because outside options are type dependent, the critical types for which individual rationality binds must be determined simultaneously with the allocation rule. We show that optimality uniquely pins down the set of critical types, which allows us to fully characterize the optimal mechanisms. Moreover, we find that the value function is Schur-concave in ownership shares when types are identically distributed, so that more symmetric shares are better irrespective of size of the revenue constraint
The biogeography of the caribou lungworm, Varestrongylus eleguneniensis (Nematoda:Protostrongylidae) across northern North America
Varestrongylus eleguneniensis (Nematoda; Protostrongylidae) is a recently described species of lungworm that infects caribou (Rangifer tarandus), muskoxen (Ovibos moschatus) and moose (Alces americanus) across northern North America. Herein we explore the geographic distribution of V. eleguneniensis through geographically extensive sampling and discuss the biogeography of this multi-host parasite. We analyzed fecal samples of three caribou subspecies (n = 1485), two muskox subspecies (n = 159), and two moose subspecies (n = 264) from across northern North America. Protostrongylid dorsal-spined larvae (DSL) were found in 23.8%, 73.6%, and 4.2% of these ungulates, respectively. A portion of recovered DSL were identified by genetic analyses of the ITS-2 region of the nuclear rDNA or the cytochrome oxidase c subunit I (COI) region of the mtDNA. We found V. eleguneniensis widely distributed among caribou and muskox populations across most of their geographic prange in North America but it was rare in moose. Parelaphostrongylus andersoni was present in caribou and moose and we provide new geographic records for this species. This study provides a substantial expansion of the knowledge defining the current distribution and biogeography of protostrongylid nematodes in northern ungulates. Insights about the host and geographic range of V. eleguneniensis can serve as a geographically extensive baseline for monitoring current distribution and in anticipating future biogeographic scenarios under a regime of accelerating climate and anthropogenic perturbation.[Display omitted]•Varestrongylus eleguneniensis is a lungworm whose primary host is the caribou.•The muscleworm, Parelaphostrongylus andersoni, co-infects caribou across its range.•We expand the knowledge on distribution of the caribou lungworm and the muscleworm.•Muskoxen sympatric with caribou are infected with the caribou lungworm.•We discuss the biogeography of V. eleguneniensis and Rangifer across North America
Age and sex influence social interactions, but not associations, within a killer whale pod
This is the author accepted manuscript. The final version is available from the Royal Society via the DOI in this record.Data accessibility:
The processed contact, surfacing, and association networks, measures of dyadic
sampling effort, estimated maternal kinship, individual attributes, and functions to
conduct GLMQAP and general double-semi-partialling are included in the “aninet” R
package on GitHub (https://github.com/MNWeiss/aninet). The raw time-series of
detections and interactions, and R code necessary to reproduce all analyses, are
available in the online supplementary material.Social structure is a fundamental aspect of animal populations. In order to understand
the function and evolution of animal societies, it is important to quantify how individual
attributes, such as age and sex, shape social relationships. Detecting these influences
in wild populations under natural conditions can be challenging, especially when social
interactions are difficult to observe and broad-scale measures of association are used
as a proxy. In this study, we use unoccupied aerial systems to observe association,
synchronous surfacing, and physical contact within a pod of southern resident killer
whales (Orcinus orca). We show that interactions do not occur randomly between
associated individuals, and that interaction types are not interchangeable. While age
and sex did not detectably influence association network structure, both interaction networks showed significant social homophily by age and sex, and centrality within the
contact network was higher among females and young individuals. These results
suggest killer whales exhibit interesting parallels in social bond formation and social
life histories with primates and other terrestrial social mammals, and demonstrate how
important patterns can be missed when using associations as a proxy for interactions
in animal social network studies.Natural Environment Research Council (NERC)National Fish and Wildlife FoundationPaul G Allen Family FoundationUW Center for Conservation BiologyCenter for Whale Researc
Genotyping faecal samples of Bengal tiger Panthera tigris tigris for population estimation: A pilot study
BACKGROUND: Bengal tiger Panthera tigris tigris the National Animal of India, is an endangered species. Estimating populations for such species is the main objective for designing conservation measures and for evaluating those that are already in place. Due to the tiger's cryptic and secretive behaviour, it is not possible to enumerate and monitor its populations through direct observations; instead indirect methods have always been used for studying tigers in the wild. DNA methods based on non-invasive sampling have not been attempted so far for tiger population studies in India. We describe here a pilot study using DNA extracted from faecal samples of tigers for the purpose of population estimation. RESULTS: In this study, PCR primers were developed based on tiger-specific variations in the mitochondrial cytochrome b for reliably identifying tiger faecal samples from those of sympatric carnivores. Microsatellite markers were developed for the identification of individual tigers with a sibling Probability of Identity of 0.005 that can distinguish even closely related individuals with 99.9% certainty. The effectiveness of using field-collected tiger faecal samples for DNA analysis was evaluated by sampling, identification and subsequently genotyping samples from two protected areas in southern India. CONCLUSION: Our results demonstrate the feasibility of using tiger faecal matter as a potential source of DNA for population estimation of tigers in protected areas in India in addition to the methods currently in use
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