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This Letter presents the results from pointlike neutrino source searches using ten years of IceCube data collected between April 6, 2008 and July 10, 2018. We evaluate the significance of an astrophysical signal from a pointlike source looking for an excess of clustered neutrino events with energies typically above â¼1 TeV among the background of atmospheric muons and neutrinos. We perform a full-sky scan, a search within a selected source catalog, a catalog population study, and three stacked Galactic catalog searches. The most significant point in the northern hemisphere from scanning the sky is coincident with the Seyfert II galaxy NGC 1068, which was included in the source catalog search. The excess at the coordinates of NGC 1068 is inconsistent with background expectations at the level of 2.9σ after accounting for statistical trials from the entire catalog. The combination of this result along with excesses observed at the coordinates of three other sources, including TXS 0506+056, suggests that, collectively, correlations with sources in the northern catalog are inconsistent with background at 3.3σ significance. The southern catalog is consistent with background. These results, all based on searches for a cumulative neutrino signal integrated over the 10 years of available data, motivate further study of these and similar sources, including time-dependent analyses, multimessenger correlations, and the possibility of stronger evidence with coming upgrades to the detector.
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We report on the first measurement of the astrophysical neutrino flux using particle showers (cascades) in IceCube data from 2010-2015. Assuming standard oscillations, the astrophysical neutrinos in this dedicated cascade sample are dominated (â¼90%) by electron and tau flavors. The flux, observed in the sensitive energy range from 16 TeV to 2.6 PeV, is consistent with a single power-law model as expected from Fermi-type acceleration of high energy particles at astrophysical sources. We find the flux spectral index to be γ=2.53±0.07 and a flux normalization for each neutrino flavor of Ï_{astro}=1.66_{-0.27}^{+0.25} at E_{0}=100 TeV, in agreement with IceCube's complementary muon neutrino results and with all-neutrino flavor fit results. In the measured energy range we reject spectral indices γ≤2.28 at ≥3σ significance level. Because of high neutrino energy resolution and low atmospheric neutrino backgrounds, this analysis provides the most detailed characterization of the neutrino flux at energies below â¼100 TeV compared to previous IceCube results. Results from fits assuming more complex neutrino flux models suggest a flux softening at high energies and a flux hardening at low energies (p value ≥0.06). The sizable and smooth flux measured below â¼100 TeV remains a puzzle. In order to not violate the isotropic diffuse gamma-ray background as measured by the Fermi Large Area Telescope, it suggests the existence of astrophysical neutrino sources characterized by dense environments which are opaque to gamma rays.
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High-energy neutrino emission has been predicted for several short-lived astrophysical transients including gamma-ray bursts (GRBs), core-collapse supernovae with choked jets, and neutron star mergers. IceCube's optical and x-ray follow-up program searches for such transient sources by looking for two or more muon neutrino candidates in directional coincidence and arriving within 100 s. The measured rate of neutrino alerts is consistent with the expected rate of chance coincidences of atmospheric background events and no likely electromagnetic counterparts have been identified in Swift follow-up observations. Here, we calculate generic bounds on the neutrino flux of short-lived transient sources. Assuming an E^{-2.5} neutrino spectrum, we find that the neutrino flux of rare sources, like long gamma-ray bursts, is constrained to <5% of the detected astrophysical flux and the energy released in neutrinos (100 GeV to 10 PeV) by a median bright GRB-like source is <10^{52.5} erg. For a harder E^{-2.13} neutrino spectrum up to 30% of the flux could be produced by GRBs and the allowed median source energy is <10^{52} erg. A hypothetical population of transient sources has to be more common than 10^{-5} Mpc^{-3} yr^{-1} (5×10^{-8} Mpc^{-3} yr^{-1} for the E^{-2.13} spectrum) to account for the complete astrophysical neutrino flux.
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We present a measurement of the atmospheric neutrino oscillation parameters using three years of data from the IceCube Neutrino Observatory. The DeepCore infill array in the center of IceCube enables the detection and reconstruction of neutrinos produced by the interaction of cosmic rays in Earth's atmosphere at energies as low as â¼5 GeV. That energy threshold permits measurements of muon neutrino disappearance, over a range of baselines up to the diameter of the Earth, probing the same range of L/E_{ν} as long-baseline experiments but with substantially higher-energy neutrinos. This analysis uses neutrinos from the full sky with reconstructed energies from 5.6 to 56 GeV. We measure Δm_{32}^{2}=2.31_{-0.13}^{+0.11}×10^{-3} eV^{2} and sin^{2}θ_{23}=0.51_{-0.09}^{+0.07}, assuming normal neutrino mass ordering. These results are consistent with, and of similar precision to, those from accelerator- and reactor-based experiments.
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UNLABELLED: Promoter capture Hi-C (PCHi-C) allows the genome-wide interrogation of physical interactions between distal DNA regulatory elements and gene promoters in multiple tissue contexts. Visual integration of the resultant chromosome interaction maps with other sources of genomic annotations can provide insight into underlying regulatory mechanisms. We have developed Capture HiC Plotter (CHiCP), a web-based tool that allows interactive exploration of PCHi-C interaction maps and integration with both public and user-defined genomic datasets. AVAILABILITY AND IMPLEMENTATION: CHiCP is freely accessible from www.chicp.org and supports most major HTML5 compliant web browsers. Full source code and installation instructions are available from http://github.com/D-I-L/django-chicp CONTACT: ob219@cam.ac.uk.
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Internet , Regiões Promotoras Genéticas , Elementos Reguladores de Transcrição , Software , Cromossomos , Gráficos por Computador , Genoma , GenômicaRESUMO
We report constraints on the sources of ultrahigh-energy cosmic rays (UHECRs) above 10^{9} GeV, based on an analysis of seven years of IceCube data. This analysis efficiently selects very high- energy neutrino-induced events which have deposited energies from 5×10^{5} GeV to above 10^{11} GeV. Two neutrino-induced events with an estimated deposited energy of (2.6±0.3)×10^{6} GeV, the highest neutrino energy observed so far, and (7.7±2.0)×10^{5} GeV were detected. The atmospheric background-only hypothesis of detecting these events is rejected at 3.6σ. The hypothesis that the observed events are of cosmogenic origin is also rejected at >99% CL because of the limited deposited energy and the nonobservation of events at higher energy, while their observation is consistent with an astrophysical origin. Our limits on cosmogenic neutrino fluxes disfavor the UHECR sources having a cosmological evolution stronger than the star formation rate, e.g., active galactic nuclei and γ-ray bursts, assuming proton-dominated UHECRs. Constraints on UHECR sources including mixed and heavy UHECR compositions are obtained for models of neutrino production within UHECR sources. Our limit disfavors a significant part of parameter space for active galactic nuclei and new-born pulsar models. These limits on the ultrahigh-energy neutrino flux models are the most stringent to date.
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Plasmodium knowlesi is an intracellular malaria parasite whose natural vertebrate host is Macaca fascicularis (the 'kra' monkey); however, it is now increasingly recognized as a significant cause of human malaria, particularly in southeast Asia. Plasmodium knowlesi was the first malaria parasite species in which antigenic variation was demonstrated, and it has a close phylogenetic relationship to Plasmodium vivax, the second most important species of human malaria parasite (reviewed in ref. 4). Despite their relatedness, there are important phenotypic differences between them, such as host blood cell preference, absence of a dormant liver stage or 'hypnozoite' in P. knowlesi, and length of the asexual cycle (reviewed in ref. 4). Here we present an analysis of the P. knowlesi (H strain, Pk1(A+) clone) nuclear genome sequence. This is the first monkey malaria parasite genome to be described, and it provides an opportunity for comparison with the recently completed P. vivax genome and other sequenced Plasmodium genomes. In contrast to other Plasmodium genomes, putative variant antigen families are dispersed throughout the genome and are associated with intrachromosomal telomere repeats. One of these families, the KIRs, contains sequences that collectively match over one-half of the host CD99 extracellular domain, which may represent an unusual form of molecular mimicry.
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Genoma de Protozoário/genética , Genômica , Macaca mulatta/parasitologia , Malária/parasitologia , Plasmodium knowlesi/genética , Sequência de Aminoácidos , Animais , Antígenos CD/química , Antígenos CD/genética , Cromossomos/genética , Sequência Conservada , Genes de Protozoários/genética , Humanos , Dados de Sequência Molecular , Plasmodium knowlesi/classificação , Plasmodium knowlesi/fisiologia , Estrutura Terciária de Proteína , Proteínas de Protozoários/química , Proteínas de Protozoários/genética , Análise de Sequência de DNA , Telômero/genéticaRESUMO
With the observation of high-energy astrophysical neutrinos by the IceCube Neutrino Observatory, interest has risen in models of PeV-mass decaying dark matter particles to explain the observed flux. We present two dedicated experimental analyses to test this hypothesis. One analysis uses 6 years of IceCube data focusing on muon neutrino 'track' events from the Northern Hemisphere, while the second analysis uses 2 years of 'cascade' events from the full sky. Known background components and the hypothetical flux from unstable dark matter are fitted to the experimental data. Since no significant excess is observed in either analysis, lower limits on the lifetime of dark matter particles are derived: we obtain the strongest constraint to date, excluding lifetimes shorter than 10 28 s at 90% CL for dark matter masses above 10 TeV .
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IceCube is a neutrino observatory deployed in the glacial ice at the geographic South Pole. The ν µ energy unfolding described in this paper is based on data taken with IceCube in its 79-string configuration. A sample of muon neutrino charged-current interactions with a purity of 99.5% was selected by means of a multivariate classification process based on machine learning. The subsequent unfolding was performed using the software Truee. The resulting spectrum covers an E ν -range of more than four orders of magnitude from 125 GeV to 3.2 PeV. Compared to the Honda atmospheric neutrino flux model, the energy spectrum shows an excess of more than 1.9 σ in four adjacent bins for neutrino energies E ν ≥ 177.8 TeV . The obtained spectrum is fully compatible with previous measurements of the atmospheric neutrino flux and recent IceCube measurements of a flux of high-energy astrophysical neutrinos.
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More general and universally applicable drug discovery assay technologies are needed in order to keep pace with the recent advances in combinatorial chemistry and genomics-based target generation. Ligand-induced conformational stabilization of proteins is a well-understood phenomenon in which substrates, inhibitors, cofactors, and even other proteins provide enhanced stability to proteins on binding. This phenomenon is based on the energetic coupling of the ligand-binding and protein-melting reactions. In an attempt to harness these biophysical properties for drug discovery, fully automated instrumentation was designed and implemented to perform miniaturized fluorescence-based thermal shift assays in a microplate format for the high throughput screening of compound libraries. Validation of this process and instrumentation was achieved by investigating ligand binding to more than 100 protein targets. The general applicability of the thermal shift screening strategy was found to be an important advantage because it circumvents the need to design and retool new assays with each new therapeutic target. Moreover, the miniaturized thermal shift assay methodology does not require any prior knowledge of a therapeutic target's function, making it ideally suited for the quantitative high throughput drug screening and evaluation of targets derived from genomics.
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Miniaturização , Preparações Farmacêuticas/química , Receptor alfa de Estrogênio , Corantes Fluorescentes , Humanos , Ligantes , Proteínas/metabolismo , Receptores de Estrogênio/metabolismo , Reprodutibilidade dos Testes , TemperaturaRESUMO
Rates of photosynthesis and respiration were measured by two methods, oxygen electrode and infrared gas analysis (IRGA), in infected and control, seedling and adult leaves of oat genotypes exhibiting different levels of partial resistance. Measurements were carried out up to 9 d after inoculation, sporulation commencing on day 5. There was no decrease in the rate of photosynthesis, except in the second leaves of one genotype, and no decrease in any of the fifth leaves relative to controls. The two methods of measuring respiration gave different results, with no consistent differences being found. Measurements by oxygen electrode, up to 6 d after inoculation, revealed that disease treatment had a significant effect on respiration in only two cases; the susceptible first leaf of one genotype and the resistant fifth leaf of another. Measurements by IRGA, up to 9 d after inoculation, did not confirm these differences, but did reveal a significant increase in respiration in the diseased fifth leaf of another resistant genotype. SHAM inhibited respiration, indicating the presence of the alternative oxidase, but there was no significant difference in its activity between diseased and control plants. Thus changes in photosynthesis and respiration previously associated with powdery mildew infection are either delayed or compensated for in oats. Photosynthetic and respiratory responses do not appear to be involved in partial resistance of oats to powdery mildew.
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We tested whether uterine glucose uptake rate (UtGU), placental glucose transport rate to the fetus (PGT) and uteroplacental glucose consumption rate (UPGC) were altered in chronically catheterized pregnant sheep after 2-5 week intravenous infusions of glucose or insulin that produced sustained maternal and fetal hyper- or hypoglycemia. In the hyperglycemic animals, UtGU was greater than that of controls; the excess UtGU was partitioned into non-oxidative UPGC rather than PGT. The 'normal' rate of PGT observed in the hyperglycemic animals is probably related to suppression of fetal insulin concentration which would decrease fetal glucose clearance and thus the transplacental glucose concentration gradient. The increase in UPGC may help prevent an excessive supply of glucose to the fetus. In the hypoglycemic animals, weight-specific UPGC and uteroplacental oxygen uptake were not different from controls; placental weight also was reduced, an adaptation that maintained normal placental metabolism per unit tissue and did not disproportionately deprive the fetus of glucose supply.
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Glucose/metabolismo , Oxigênio/metabolismo , Placenta/metabolismo , Útero/metabolismo , Animais , Glicemia/metabolismo , Feminino , Sangue Fetal/metabolismo , Idade Gestacional , Insulina/sangue , Cinética , Troca Materno-Fetal , Gravidez , OvinosRESUMO
An antepartum diagnosis of vasa previa was considered in a patient in whom ultrasound revealed pulsatile loops of cord overlying the cervical os. This diagnosis was confirmed at the time of cesarean delivery. We offer a literature review of vasa previa and make recommendations for using ultrasonography to diagnose vasa previa.
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Placenta/irrigação sanguínea , Ultrassonografia , Hemorragia Uterina/etiologia , Adulto , Cesárea , Feminino , Humanos , Gravidez , Diagnóstico Pré-NatalRESUMO
Quantitation of carcinogen-DNA adducts provides an estimate of the biologically effective dose of a chemical carcinogen reaching the target tissue. In order to improve exposure-assessment and cancer risk estimates, we are developing an ultrasensitive procedure for the detection of carcinogen-DNA adducts. The method is based upon postlabeling of carcinogen-DNA adducts by acetylation with 14C-acetic anhydride combined with quantitation of 14C by accelerator mass spectrometry (AMS). For this purpose, adducts of benzo[a]pyrene-r-7,t-8-dihydrodiol-t-9,10-epoxide (BPDE) with DNA and deoxyguanosine (dG) were synthesized. The most promutagenic adduct of BPDE, 7R,8S,9R-trihydroxy-10S-(N(2)-deoxyguanosyl)-7,8,9, 10-tetrahydrobenzo[a]pyrene (BPdG), was HPLC purified and structurally characterized. Postlabeling of the BPdG adduct with acetic anhydride yielded a major product with a greater than 60% yield. The postlabeled adduct was identified by liquid chromatography-mass spectrometry as pentakis(acetyl) BPdG (AcBPdG). Postlabeling of the BPdG adduct with 14C-acetic anhydride yielded a major product coeluting with an AcBPdG standard. Quantitation of the 14C-postlabeled adduct by AMS promises to allow detection of attomolar amounts of adducts. The method is now being optimized and validated for use in human samples.
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Anidridos Acéticos/química , Benzo(a)pireno/análise , Carcinógenos Ambientais/análise , Adutos de DNA/análise , Espectrometria de Massas/métodos , Acetilação , Animais , Radioisótopos de Carbono , Bovinos , Cromatografia Líquida de Alta Pressão , Marcação por Isótopo/métodos , Espectrofotometria AtômicaRESUMO
The relative toxicity (log IGC50(-1)) of 49 selected aliphatic amines and aminoalkanols was evaluated in the static Tetrahymena pyriformis population growth impairment assay. Excess toxicity, indicated by potency greater than predicted for non-polar narcotic alkanols, was associated with both classes of test chemicals. Moreover, the aminoalkanols were found to be more toxic than the corresponding alkanamines. A high quality 1-octanol/water partition coefficient (log K(ow)) dependent quantitative structure-activity relationship (QSAR), logIGC50(-1) = 0.78 (log K(ow)) - 1.42; r2 = 0.934, was developed for alkanamines. This QSAR represented the amine narcosis mechanism of toxic action. No quality QSAR was developed for the aminoalkanols. However, several structure-toxicity features were observed for this class of chemicals. Two-amino-1-hydroxy derivatives being more toxic than the corresponding derivatives, where the amino and hydroxy moieties were separated by methylene groups. Hydrocarbon branching next to the amino moiety resulted in decreased toxicity. Aminoalkanol alters lipid metabolism in T. pyriformis.
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Alcanos/toxicidade , Aminas/toxicidade , Poluentes Químicos da Água/toxicidade , Alcanos/química , Aminas/química , Animais , Eucariotos/efeitos dos fármacos , Relação Estrutura-Atividade , Testes de Toxicidade/métodosRESUMO
Nurse case managers at this integrated delivery system implement an alternative, Web-based case management approach.
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Administração de Caso/organização & administração , Doença Crônica/enfermagem , Sistemas de Informação Administrativa , Supervisão de Enfermagem , Sistemas On-Line/organização & administração , Prestação Integrada de Cuidados de Saúde/organização & administração , Feminino , Humanos , Pessoa de Meia-Idade , Avaliação de Processos e Resultados em Cuidados de Saúde/métodos , Estados UnidosRESUMO
Physical activity (PA) is an important adjunct to bariatric surgery in the treatment of severe obesity; however, patient PA levels prior to and in the short-term following surgery are usually low. Scarce data exist describing PA and sedentary behaviours in the long term following surgery. The objectives were to describe PA and sitting time in bariatric patients 1-16 years post-surgery and assess their associations with patient, surgery and weight-loss characteristics. A total of 398 bariatric patients (73% female; mean age 47 ± 11 years, mean 6 ± 4 years since surgery) completed a telephone questionnaire. Patients reported moderate-to-vigorous PA (MVPA: # sessions week(-1) ≥30 min), sitting time (h d(-1)) and change in PA and sitting time vs. pre-surgery (more/same/less). Associations with patient, surgery and weight-loss characteristics were assessed. Only 53% of patients reported ≥1 session week(-1) MVPA, mean sitting time was 7 ± 4 h d(-1), 74% of patients reported more PA and 53% reported less sitting, now vs. pre-surgery. Age, sex, smoking status, pre-surgery body mass index, time-since-surgery and percent excess weight lost were significantly associated with PA and/or sitting outcomes. Patients currently experiencing ≥50% excess weight loss had over three times the odds of reporting ≥1 session week(-1) MVPA (odds ratio [95% confidence interval] 3.28 [1.57, 6.89]) and almost four times greater odds of reporting 'more' PA vs. pre-surgery (3.78 [2.15, 6.62]) compared with their less successful counterparts. Results point to low PA and high sedentariness among bariatric patients in the long-term following surgery, associated with several characteristics. Associations with long-term weight management highlight the need for tailored interventions to promote active living in this patient population.
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Cirurgia Bariátrica , Exercício Físico , Obesidade Mórbida/psicologia , Obesidade Mórbida/cirurgia , Comportamento Sedentário , Adulto , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Atividade Motora , Fumar , Fatores de Tempo , Redução de PesoAssuntos
Ascomicetos/fisiologia , Hordeum/microbiologia , Fungos Mitospóricos/fisiologia , Ascomicetos/enzimologia , Ascomicetos/ultraestrutura , Hidrolases de Éster Carboxílico/fisiologia , Regulação Fúngica da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Hordeum/genética , Hordeum/imunologia , Hordeum/ultraestrutura , Fungos Mitospóricos/enzimologia , Fungos Mitospóricos/ultraestrutura , Doenças das Plantas/microbiologiaRESUMO
SUMMARY Here, we consider the barley powdery mildew fungus, Blumeria graminis (DC Speer) f.sp. hordei (Marchal), and review recent research which has added to our understanding of the biology and molecular biology which underpins the asexual life cycle of this potentially devastating pathogen. We focus on the early stages of the host-pathogen interaction and report current understanding in the areas of leaf perception, fungal signal transduction and host-imposed oxidative stress management. Through this, it is becoming increasingly clear how closely and subtly both sides of the relationship are regulated. Collectively, however, this review highlights the high degree of complexity in working with an obligate parasite. Our experiences suggest that we would make more efficient progress towards understanding the basis of susceptibility and resistance to this true obligate biotroph if its genome sequence was available.