The groupoidal analogue Theta~ to Joyal's category Theta is a test category

We introduce the groupoidal analogue \tilde\Theta to Joyal's cell category \Theta and we prove that \tilde\Theta is a strict test category in the sense of Grothendieck. This implies that presheaves on \tilde\Theta model homotopy types in a canonical way. We also prove that the canonical functor from \Theta to \tilde\Theta is aspherical, again in the sense of Grothendieck. This allows us to compare weak equivalences of presheaves on \tilde\Theta to weak equivalences of presheaves on \Theta. Our proofs apply to other categories analogous to \Theta.Comment: 41 pages, v2: references added, Remark 7.3 added, v3: metadata update

Advanced Scientific Computing Environment Team new scientific database management task

The mission of the ASCENT Team is to continually keep pace with, evaluate, and select emerging computing technologies to define and implement prototypic scientific environments that maximize the ability of scientists and engineers to manage scientific data. These environments are to be implemented in a manner consistent with the site computing architecture and standards and NRTSC/SCS strategic plans for scientific computing. The major trends in computing hardware and software technology clearly indicate that the future computer'' will be a network environment that comprises supercomputers, graphics boxes, mainframes, clusters, workstations, terminals, and microcomputers. This network computer'' will have an architecturally transparent operating system allowing the applications code to run on any box supplying the required computing resources. The environment will include a distributed database and database managing system(s) that permits use of relational, hierarchical, object oriented, GIS, et al, databases. To reach this goal requires a stepwise progression from the present assemblage of monolithic applications codes running on disparate hardware platforms and operating systems. The first steps include converting from the existing JOSHUA system to a new J80 system that complies with modern language standards, development of a new J90 prototype to provide JOSHUA capabilities on Unix platforms, development of portable graphics tools to greatly facilitate preparation of input and interpretation of output; and extension of Jvv'' concepts and capabilities to distributed and/or parallel computing environments

Near-threshold measurement of the 4He(g,n) reaction

A near-threshold 4He(g,n) cross-section measurement has been performed at MAX-lab. Tagged photons from 23 < Eg < 42 MeV were directed toward a liquid 4He target, and neutrons were detected by time-of-flight in two liquid-scintillator arrays. Seven-point angular distributions were measured for eight photon energies. The results are compared to experimental data measured at comparable energies and Recoil-Corrected Continuum Shell Model, Resonating Group Method, and recent Hyperspherical-Harmonic Expansion calculations. The angle-integrated cross-section data is peaked at a photon energy of about 28 MeV, in disagreement with the value recommended by Calarco, Berman, and Donnelly in 1983.Comment: 10 pages, 3 figures, some revisions, submitted to Physics Letters

γ -ray spectroscopy of astrophysically important states in Ca 39

Background: Nova explosions synthesize elements up to A≃40, and discrepancies exist between calculated and observed abundances of Ar and Ca created in the explosion. The K38(p,γ)Ca39 reaction rate has been shown to be influential on these isotopic abundances at the endpoint of nova nucleosynthesis. The energies of the three most important resonances, corresponding to Jπ=5/2+ excited states in the Ca39 nucleus above the proton separation threshold, are uncertain and one has been measured with conflicting values [Er=679(2) versus Er=701(2) keV] in previous experiments. Purpose: Reducing the uncertainties on the resonance energies would allow for a better understanding of the reaction rate. To improve these uncertainties, we searched for γ rays from the depopulation of the corresponding excited states in Ca39. Methods: We report a new measurement of these resonance energies via the observation of previously unobserved γ-ray transitions. These transitions were observed by studying the Ca40(3He,αγ)Ca39 reaction with Gammasphere ORRUBA Dual Detectors for Experimental Structure Studies (GODDESS). The updated resonance energies were then used to calculate the K38(p,γ)Ca39 reaction rate and assess its uncertainties. Results: In total, 23 new transitions were found, including three γ-ray transitions corresponding to the three Jπ=5/2+ states of astrophysical interest at energies of 6156.2(16), 6268.8(22), and 6470.8(19) keV. These correspond to resonance energies in the K38(p,γ)Ca39 reaction of 386(2), 498(2), and 701(2) keV. Conclusions: Updated K38(p,γ)Ca39 reaction rate calculations show a reduced upper limit at nova temperatures. However, the lower-than-previously-measured energy of the 498-keV resonance and uncertainty in its resonance strength increases the upper limit of the rate close to previous estimates at 0.4 GK

New γ -ray transitions observed in Ne 19 with implications for the O 15 (α,γ) Ne 19 reaction rate

The O15(α,γ)Ne19 reaction is responsible for breakout from the hot CNO cycle in type I x-ray bursts. Understanding the properties of resonances between Ex=4 and 5 MeV in Ne19 is crucial in the calculation of this reaction rate. The spins and parities of these states are well known, with the exception of the 4.14- and 4.20-MeV states, which have adopted spin-parities of 9/2- and 7/2-, respectively. γ-ray transitions from these states were studied using triton-γ-γ coincidences from the F19(He3,tγ)Ne19 reaction measured with the GODDESS (Gammasphere ORRUBA Dual Detectors for Experimental Structure Studies) at Argonne National Laboratory. The observed transitions from the 4.14- and 4.20-MeV states provide strong evidence that the Jπ values are actually 7/2- and 9/2-, respectively. These assignments are consistent with the values in the F19 mirror nucleus and in contrast to previously accepted assignments

Platypus and echidna genomes reveal mammalian biology and evolution

Published online: 6 January 2021Egg-laying mammals (monotremes) are the only extant mammalian outgroup to therians (marsupial and eutherian animals) and provide key insights into mammalian evolution (1,2). Here we generate and analyse reference genomes of the platypus (Ornithorhynchus anatinus) and echidna (Tachyglossus aculeatus), which represent the only two extant monotreme lineages. The nearly complete platypus genome assembly has anchored almost the entire genome onto chromosomes, markedly improving the genome continuity and gene annotation. Together with our echidna sequence, the genomes of the two species allow us to detect the ancestral and lineage-specific genomic changes that shape both monotreme and mammalian evolution. We provide evidence that the monotreme sex chromosome complex originated from an ancestral chromosome ring configuration. The formation of such a unique chromosome complex may have been facilitated by the unusually extensive interactions between the multi-X and multi-Y chromosomes that are shared by the autosomal homologues in humans. Further comparative genomic analyses unravel marked differences between monotremes and therians in haptoglobin genes, lactation genes and chemosensory receptor genes for smell and taste that underlie the ecological adaptation of monotremes.Yang Zhou, Linda Shearwin-Whyatt, Jing Li, Zhenzhen Song, Takashi Hayakawa, David Stevens, Jane C. Fenelon, Emma Peel, Yuanyuan Cheng, Filip Pajpach, Natasha Bradley, Hikoyu Suzuki, Masato Nikaido, Joana Damas, Tasman Daish, Tahlia Perry, Zexian Zhu, Yuncong Geng, Arang Rhie, Ying Sims, Jonathan Wood, Bettina Haase, Jacquelyn Mountcastle, Olivier Fedrigo, Qiye Li, Huanming Yang, Jian Wang, Stephen D. Johnston, Adam M. Phillippy, Kerstin Howe, Erich D. Jarvis, Oliver A. Ryder, Henrik Kaessmann, Peter Donnelly, Jonas Korlach, Harris A. Lewin, Jennifer Graves, Katherine Belov, Marilyn B. Renfree, Frank Grutzner, Qi Zhou, Guojie Zhan

Follow-up of loci from the International Genomics of Alzheimer's Disease Project identifies TRIP4 as a novel susceptibility gene

To follow-up loci discovered by the International Genomics of Alzheimer's Disease Project, we attempted independent replication of 19 single nucleotide polymorphisms (SNPs) in a large Spanish sample (Fundació ACE data set; 1808 patients and 2564 controls). Our results corroborate association with four SNPs located in the genes INPP5D, MEF2C, ZCWPW1 and FERMT2, respectively. Of these, ZCWPW1 was the only SNP to withstand correction for multiple testing (P=0.000655). Furthermore, we identify TRIP4 (rs74615166) as a novel genome-wide significant locus for Alzheimer's disease risk (odds ratio=1.31; confidence interval 95% (1.19-1.44); P=9.74 × 10 - 9)

Technical summary

The Working Group III (WGIII) contribution to the IPCC's Fifth Assessment Report (AR5) assesses literature on the scientific, technological, environmental, economic and social aspects of mitigation of climate change. It builds upon the WGIII contribution to the IPCC's Fourth Assessment Report (AR4), the Special Report on Renewable Energy Sources and Climate Change Mitigation (SRREN) and previous reports and incorporates subsequent new findings and research. Throughout, the focus is on the implications of its findings for policy, without being prescriptive about the particular policies that governments and other important participants in the policy process should adopt. In light of the IPCC's mandate, authors in WGIII were guided by several principles when assembling this assessment: (1) to be explicit about mitigation options, (2) to be explicit about their costs and about their risks and opportunities vis-a-vis other development priorities, (3) and to be explicit about the underlying criteria, concepts, and methods for evaluating alternative policies. This summary offers the main findings of the report

Common variants near MC4R are associated with fat mass, weight and risk of obesity.

To identify common variants influencing body mass index (BMI), we analyzed genome-wide association data from 16,876 individuals of European descent. After previously reported variants in FTO, the strongest association signal (rs17782313, P = 2.9 x 10(-6)) mapped 188 kb downstream of MC4R (melanocortin-4 receptor), mutations of which are the leading cause of monogenic severe childhood-onset obesity. We confirmed the BMI association in 60,352 adults (per-allele effect = 0.05 Z-score units; P = 2.8 x 10(-15)) and 5,988 children aged 7-11 (0.13 Z-score units; P = 1.5 x 10(-8)). In case-control analyses (n = 10,583), the odds for severe childhood obesity reached 1.30 (P = 8.0 x 10(-11)). Furthermore, we observed overtransmission of the risk allele to obese offspring in 660 families (P (pedigree disequilibrium test average; PDT-avg) = 2.4 x 10(-4)). The SNP location and patterns of phenotypic associations are consistent with effects mediated through altered MC4R function. Our findings establish that common variants near MC4R influence fat mass, weight and obesity risk at the population level and reinforce the need for large-scale data integration to identify variants influencing continuous biomedical traits