200 research outputs found
Measurement of the cosmic ray hadron spectrum up to 30 TeV at mountain altitude: the primary proton spectrum
The flux of cosmic ray hadrons at the atmospheric depth of 820 g/cm^2 has
been measured by means of the EAS-TOP hadron calorimeter (Campo Imperatore,
National Gran Sasso Laboratories, 2005 m a.s.l.). The hadron spectrum is well
described by a single power law : S(E_h) = (2.25 +- 0.21 +- 0.34(sys))
10^(-7)(E_h/1000)^(-2.79 +- 0.05) m^(-2) s^(-1) sr^(-1) GeV^(-1) over the
energy range 30 GeV-30 TeV. The procedure and the accuracy of the measurement
are discussed. The primary proton spectrum is derived from the data by using
the CORSIKA/QGSJET code to compute the local hadron flux as a function of the
primary proton spectrum and to calculate and subtract the heavy nuclei
contribution (basing on direct measurements). Over a wide energy range E_0 =
0.5-50 TeV its best fit is given by a single power law : S(E_0) = (9.8 +- 1.1
+- 1.6(sys)) 10^(-5) (E_0/1000)^(-2.80 +- 0.06) m^(-2) s^(-1) sr^(-1) GeV^(-1).
The validity of the CORSIKA/QGSJET code for such application has been checked
using the EAS-TOP and KASCADE experimental data by reproducing the ratio of the
measured hadron fluxes at the two experimental depths (820 and 1030 g/cm^2
respectively) at better than 10% in the considered energy range.Comment: 16 pages, 9 figures, accepted for publication in Astroparticle
Physic
Genetic characterization of a brangus-ibage cattle population: biochemical polymorphisms and reproductive efficiency
Functional Anatomy of the Female Pelvic Floor
The anatomic structures in the female that prevent incontinence and genital organ prolapse on increases in abdominal pressure during daily activities include sphincteric and supportive systems. In the urethra, the action of the vesical neck and urethral sphincteric mechanisms maintains urethral closure pressure above bladder pressure. Decreases in the number of striated muscle fibers of the sphincter occur with age and parity. A supportive hammock under the urethra and vesical neck provides a firm backstop against which the urethra is compressed during increases in abdominal pressure to maintain urethral closure pressures above the rapidly increasing bladder pressure. This supporting layer consists of the anterior vaginal wall and the connective tissue that attaches it to the pelvic bones through the pubovaginal portion of the levator ani muscle, and the uterosacral and cardinal ligaments comprising the tendinous arch of the pelvic fascia. At rest the levator ani maintains closure of the urogenital hiatus. They are additionally recruited to maintain hiatal closure in the face of inertial loads related to visceral accelerations as well as abdominal pressurization in daily activities involving recruitment of the abdominal wall musculature and diaphragm. Vaginal birth is associated with an increased risk of levator ani defects, as well as genital organ prolapse and urinary incontinence. Computer models indicate that vaginal birth places the levator ani under tissue stretch ratios of up to 3.3 and the pudendal nerve under strains of up to 33%, respectively. Research is needed to better identify the pathomechanics of these conditions.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72597/1/annals.1389.034.pd
Search for high-energy neutrinos from gravitational wave event GW151226 and candidate LVT151012 with ANTARES and IceCube
The Advanced LIGO observatories detected gravitational waves from two binary black hole mergers during their first observation run (O1). We present a high-energy neutrino follow-up search for the second gravitational wave event, GW151226, as well as for gravitational wave candidate LVT151012. We find two and four neutrino candidates detected by IceCube, and one and zero detected by Antares, within ±500 s around the respective gravitational wave signals, consistent with the expected background rate. None of these neutrino candidates are found to be directionally coincident with GW151226 or LVT151012. We use nondetection to constrain isotropic-equivalent high-energy neutrino emission from GW151226, adopting the GW event's 3D localization, to less than 2×1051-2×1054 erg. © 2017 American Physical Society
GW250114: Testing Hawking’s area law and the Kerr nature of black holes
The gravitational-wave signal GW250114 was observed by the two LIGO detectors with a network matched-filter signal-to-noise ratio of 80. The signal was emitted by the coalescence of two black holes with near-equal masses m1 ¼ 33.6þ1.2 −0.8M⊙ and m2 ¼ 32.2þ0.8 −1.3M⊙, and small spins χ1;2 ≤ 0.26 (90% credibility) and negligible eccentricity e ≤ 0.03. Postmerger data excluding the peak region are consistent with the dominant quadrupolar ðl ¼ jmj ¼ 2Þ mode of a Kerr black hole and its first overtone. We constrain the modes’ frequencies to 30% of the Kerr spectrum, providing a test of the remnant’s Kerr nature. We also examine Hawking’s area law, also known as the second law of black hole mechanics, which states that the total area of the black hole event horizons cannot decrease with time. A range of analyses that exclude up to five of the strongest merger cycles confirm that the remnant area is larger than the sum of the initial areas to high credibility
Search for eccentric black hole coalescences during the third observing run of LIGO and Virgo
Despite the growing number of binary black hole coalescences confidently observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include the effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that have already been identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total source-frame mass M > 70 M⊙) binaries covering eccentricities up to 0.3 at 15 Hz emitted gravitational-wave frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place a conservative upper limit for the merger rate density of high-mass binaries with eccentricities 0 < e ≤ 0.3 at 16.9 Gpc−3 yr−1 at the 90% confidence level
Constraints on the Cosmic Expansion History from GWTC-3
This material is based upon work supported by NSFʼs LIGO
Laboratory, which is a major facility fully funded by the National
Science Foundation. The authors also gratefully acknowledge the
support of the Science and Technology Facilities Council (STFC)
of the United Kingdom, the Max-Planck-Society (MPS), and the
State of Niedersachsen/Germany for support of the construction
of Advanced LIGO and construction and operation of the
GEO600 detector. Additional support for Advanced LIGO was
provided by the Australian Research Council. The authors
gratefully acknowledge the Italian Istituto Nazionale di Fisica
Nucleare (INFN), the French Centre National de la Recherche
Scientifique (CNRS), and the Netherlands Organization for
Scientific Research (NWO), for the construction and operation
of the Virgo detector and the creation and support of the EGO
consortium. The authors also gratefully acknowledge research
support from these agencies as well as by the Council of Scientific
and Industrial Research of India, the Department of Science and
Technology, India, the Science & Engineering Research Board
(SERB), India, the Ministry of Human Resource Development,
India, the Spanish Agencia Estatal de Investigación (AEI), the
Spanish Ministerio de Ciencia e Innovación and Ministerio de
Universidades, the Conselleria de Fons Europeus, Universitat i
Cultura and the Direcció General de Política Universitaria i
Recerca del Govern de les Illes Balears, the Conselleria
d’Innovació Universitats, Ciència i Societat Digital de la
Generalitat Valenciana and the CERCA Programme Generalitat
de Catalunya, Spain, the National Science Centre of Poland and
the European Union–European Regional Development Fund,
Foundation for Polish Science (FNP), the Swiss National Science
Foundation (SNSF), the Russian Foundation for Basic Research,
the Russian Science Foundation, the European Commission, the
European Social Funds (ESF), the European Regional Develop-
ment Funds (ERDF), the Royal Society, the Scottish Funding
Council, the Scottish Universities Physics Alliance, the Hungarian
Scientific Research Fund (OTKA), the French Lyon Institute of
Origins (LIO), the Belgian Fonds de la Recherche Scientifique
(FRS-FNRS), Actions de Recherche Concertées (ARC) and
Fonds Wetenschappelijk Onderzoek–Vlaanderen (FWO), Bel-
gium, the Paris Île-de-France Region, the National Research,
Development and Innovation Office Hungary (NKFIH), the
National Research Foundation of Korea, the Natural Science and
Engineering Research Council Canada, Canadian Foundation for
Innovation (CFI), the Brazilian Ministry of Science, Technology,
and Innovations, the International Center for Theoretical Physics
South American Institute for Fundamental Research (ICTP-
SAIFR), the Research Grants Council of Hong Kong, the National
Natural Science Foundation of China (NSFC), the Leverhulme
Trust, the Research Corporation, the Ministry of Science and
Technology (MOST), Taiwan, the United States Department of
Energy, and the Kavli Foundation. The authors gratefully
acknowledge the support of the NSF, STFC, INFN, and CNRS
for provision of computational resources.
This work was supported by MEXT, JSPS Leading-edge
Research Infrastructure Program, JSPS Grant-in-Aid for
Specially Promoted Research 26000005, JSPS Grant-in-Aid
for Scientific Research on Innovative Areas 2905:
JP17H06358, JP17H06361, and JP17H06364, JSPS Core-to-
Core Program A. Advanced Research Networks, JSPS Grant-
in-Aid for Scientific Research (S) 17H06133 and 20H05639,
JSPS Grant-in-Aid for Transformative Research Areas (A)
20A203: JP20H05854, the joint research program of the
Institute for Cosmic Ray Research, University of Tokyo,
National Research Foundation (NRF) and Computing Infra-
structure Project of KISTI-GSDC in Korea, Academia Sinica
(AS), AS Grid Center (ASGC), and the Ministry of Science and
Technology (MoST) in Taiwan under grants including AS-
CDA-105-M06, Advanced Technology Center (ATC) of
NAOJ, Mechanical Engineering Center of KEK.
We would like to thank all of the essential workers who put
their health at risk during the COVID-19 pandemic, without
whom we would not have been able to complete this work.Peer reviewe
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