434 research outputs found
CALONECTRIS BOREALIS (AVES, PROCELLARIIDAE) COMO UN REGISTRO NUEVO PARA DOS ESPECIES DE NEMĂTODOS EN BRASIL
Contracaecum pelagicum Johnston & Mawson, 1942 y Seuratia shipleyi (Stossich, 1900) estån registrados en Brasil parasitando Calonectris borealis (Cory, 1881), que es un nuevo huésped para ambas especies. Se presentam las principales medidas de estas especies en el nuevo huésped
Suitability Analysis of Groundwater for Eco-friendly Agricultural Growths in Food Basket of Pakistan
Water is an important component of earthâs atmosphere and it sustains ecosystems, agriculture and human settlements on earth (Samson et al., 2010). Salinity, sodicity and toxicity generally need to be considered for the evaluation of suitable quality of groundwater for irrigation (Khan et al., 2014; Cobbina et al., 2012; Todd and Mays, 2005). In Thal Doab Aquifer (TDA) groundwater occurs as a layer of fresh water over saline water and its availability is subjected to recharging potency of the Indus and Chenab rivers (Hussain et al., 2017 a, 2016 a)
Geometric Thermodynamics of Schwarzschild-AdS black hole with a Cosmological Constant as State Variable
The thermodynamics of the Schwarzschild-AdS black hole is reformulated within
the context of the recently developed formalism of geometrothermodynamics
(GTD). Different choices of the metric in the equilibrium states manifold are
used in order to reproduce the Hawking-Page phase transition as a divergence of
the thermodynamical curvature scalar. We show that the enthalpy and total
energy representations of GTD does not reproduce the transition while the
entropy rep- resentation gives the expected behavior.Comment: 14 page
LISTA DE CESTODA DO BRASIL
Se presenta una lista completa de las 432 especies de Cestoda que se han descrito y / o registrados en Brasil. Se distribuyen atravĂ©s de 15 Ăłrdenes y 36 familias; 50 especies no fueron identificadas y 9 se consideran species inquirenda. Entre los peces, Zungaro zungaro (Humboldt in Humboldt & Valenciennes, 1821) fue el hospedador que fue mĂĄs parasitadas (con 18 especies de cestodos); entre los anfibios, fue Rhinella icterica Spix, 1824, con 3 especies; y entre los reptiles, fue Bothrops jararaca (Wied-Neuwied, 1824), con 7 especies. Entre las aves, Gallus gallus (Linnaeus, 1758) presentĂł el mayor numero de asociaciones con cestodos, de tal manera que 13 especies se han registrado en Brasil y teniendo en cuenta los mamĂferos, Homo sapiens (Linnaeus, 1758) presentan 13 especies diferentes. Pocos representantes de estas especies de cestode se reportaran de invertebrados. El pequeño nĂșmero de los helmintos parĂĄsitos descritos es probablemente debido al submuestreo de hospedadores potenciales, junto con el pequeño nĂșmero de expertos en la taxonomĂa de los parĂĄsitos
Calibration of the Logarithmic-Periodic Dipole Antenna (LPDA) Radio Stations at the Pierre Auger Observatory using an Octocopter
An in-situ calibration of a logarithmic periodic dipole antenna with a
frequency coverage of 30 MHz to 80 MHz is performed. Such antennas are part of
a radio station system used for detection of cosmic ray induced air showers at
the Engineering Radio Array of the Pierre Auger Observatory, the so-called
Auger Engineering Radio Array (AERA). The directional and frequency
characteristics of the broadband antenna are investigated using a remotely
piloted aircraft (RPA) carrying a small transmitting antenna. The antenna
sensitivity is described by the vector effective length relating the measured
voltage with the electric-field components perpendicular to the incoming signal
direction. The horizontal and meridional components are determined with an
overall uncertainty of 7.4^{+0.9}_{-0.3} % and 10.3^{+2.8}_{-1.7} %
respectively. The measurement is used to correct a simulated response of the
frequency and directional response of the antenna. In addition, the influence
of the ground conductivity and permittivity on the antenna response is
simulated. Both have a negligible influence given the ground conditions
measured at the detector site. The overall uncertainties of the vector
effective length components result in an uncertainty of 8.8^{+2.1}_{-1.3} % in
the square root of the energy fluence for incoming signal directions with
zenith angles smaller than 60{\deg}.Comment: Published version. Updated online abstract only. Manuscript is
unchanged with respect to v2. 39 pages, 15 figures, 2 table
Multi-resolution anisotropy studies of ultrahigh-energy cosmic rays detected at the Pierre Auger Observatory
We report a multi-resolution search for anisotropies in the arrival
directions of cosmic rays detected at the Pierre Auger Observatory with local
zenith angles up to and energies in excess of 4 EeV ( eV). This search is conducted by measuring the angular power spectrum
and performing a needlet wavelet analysis in two independent energy ranges.
Both analyses are complementary since the angular power spectrum achieves a
better performance in identifying large-scale patterns while the needlet
wavelet analysis, considering the parameters used in this work, presents a
higher efficiency in detecting smaller-scale anisotropies, potentially
providing directional information on any observed anisotropies. No deviation
from isotropy is observed on any angular scale in the energy range between 4
and 8 EeV. Above 8 EeV, an indication for a dipole moment is captured; while no
other deviation from isotropy is observed for moments beyond the dipole one.
The corresponding -values obtained after accounting for searches blindly
performed at several angular scales, are in the case of
the angular power spectrum, and in the case of the needlet
analysis. While these results are consistent with previous reports making use
of the same data set, they provide extensions of the previous works through the
thorough scans of the angular scales.Comment: Published version. Added journal reference and DOI. Added Report
Numbe
Ultrahigh-energy neutrino follow-up of Gravitational Wave events GW150914 and GW151226 with the Pierre Auger Observatory
On September 14, 2015 the Advanced LIGO detectors observed their first
gravitational-wave (GW) transient GW150914. This was followed by a second GW
event observed on December 26, 2015. Both events were inferred to have arisen
from the merger of black holes in binary systems. Such a system may emit
neutrinos if there are magnetic fields and disk debris remaining from the
formation of the two black holes. With the surface detector array of the Pierre
Auger Observatory we can search for neutrinos with energy above 100 PeV from
point-like sources across the sky with equatorial declination from about -65
deg. to +60 deg., and in particular from a fraction of the 90% confidence-level
(CL) inferred positions in the sky of GW150914 and GW151226. A targeted search
for highly-inclined extensive air showers, produced either by interactions of
downward-going neutrinos of all flavors in the atmosphere or by the decays of
tau leptons originating from tau-neutrino interactions in the Earth's crust
(Earth-skimming neutrinos), yielded no candidates in the Auger data collected
within s around or 1 day after the coordinated universal time (UTC)
of GW150914 and GW151226, as well as in the same search periods relative to the
UTC time of the GW candidate event LVT151012. From the non-observation we
constrain the amount of energy radiated in ultrahigh-energy neutrinos from such
remarkable events.Comment: Published version. Added journal reference and DOI. Added Report
Numbe
A search for point sources of EeV photons
Measurements of air showers made using the hybrid technique developed with
the fluorescence and surface detectors of the Pierre Auger Observatory allow a
sensitive search for point sources of EeV photons anywhere in the exposed sky.
A multivariate analysis reduces the background of hadronic cosmic rays. The
search is sensitive to a declination band from -85{\deg} to +20{\deg}, in an
energy range from 10^17.3 eV to 10^18.5 eV. No photon point source has been
detected. An upper limit on the photon flux has been derived for every
direction. The mean value of the energy flux limit that results from this,
assuming a photon spectral index of -2, is 0.06 eV cm^-2 s^-1, and no celestial
direction exceeds 0.25 eV cm^-2 s^-1. These upper limits constrain scenarios in
which EeV cosmic ray protons are emitted by non-transient sources in the
Galaxy.Comment: 28 pages, 10 figures, accepted for publication in The Astrophysical
Journa
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