2,380 research outputs found
Probing the magnetic ground state of the molecular Dysprosium triangle
We present zero field muon spin lattice relaxation measurements of a
Dysprosium triangle molecular magnet. The local magnetic fields sensed by the
implanted muons indicate the coexistence of static and dynamic internal
magnetic fields below K. Bulk magnetization and heat capacity
measurements show no indication of magnetic ordering below this temperature. We
attribute the static fields to the slow relaxation of the magnetization in the
ground state of Dy3. The fluctuation time of the dynamic part of the field is
estimated to be ~0.55 s at low temperaturesComment: 5 pages, 5 figures, accepted for publication in Phys. Rev.
The Nonlinear Cosmological Matter Power Spectrum with Massive Neutrinos I: The Halo Model
Measurements of the linear power spectrum of galaxies have placed tight
constraints on neutrino masses. We extend the framework of the halo model of
cosmological nonlinear matter clustering to include the effect of massive
neutrino infall into cold dark matter (CDM) halos. The magnitude of the effect
of neutrino clustering for three degenerate mass neutrinos with m_nu=0.9 eV is
of order ~1%, within the potential sensitivity of upcoming weak lensing
surveys. In order to use these measurements to further constrain--or eventually
detect--neutrino masses, accurate theoretical predictions of the nonlinear
power spectrum in the presence of massive neutrinos will be needed, likely only
possible through high-resolution multiple particle (neutrino, CDM and baryon)
simulations.Comment: v2: matches PRD versio
Distibusi Bivalvia (Moluska) Di Danau Sipogas Kabupaten Rokan Hulu Provinsi Riau
The aims of this study was to determine distribution of Bivalvia (Mollusca) in Sipogas Lake Rokan Hulu Regency, Riau Province. The study was conducted in November to December 2014 with survey method. Sample collected by using eckman dredge with purposive random sampling, with four stations. Results showed, 1 species was found, it was Corbicula javanica with a total number of 77 individuals. The density was ranged from 17.78 to 64 individuals/m2, with distribution patterns on pattern of grouped distribution
Precise Particle Tracking Against a Complicated Background: Polynomial Fitting with Gaussian Weight
We present a new particle tracking software algorithm designed to accurately
track the motion of low-contrast particles against a background with large
variations in light levels. The method is based on a polynomial fit of the
intensity around each feature point, weighted by a Gaussian function of the
distance from the centre, and is especially suitable for tracking endogeneous
particles in the cell, imaged with bright field, phase contrast or fluorescence
optical microscopy. Furthermore, the method can simultaneously track particles
of all different sizes, and allows significant freedom in their shape. The
algorithm is evaluated using the quantitative measures of accuracy and
precision of previous authors, using simulated images at variable
signal-to-noise ratios. To these we add a new test of the error due to a
non-uniform background. Finally the tracking of particles in real cell images
is demonstrated. The method is made freely available for non-commencial use as
a software package with a graphical user-inferface, which can be run within the
Matlab programming environment
The Inflationary Perturbation Spectrum
Motivated by the prospect of testing inflation from precision cosmic
microwave background observations, we present analytic results for scalar and
tensor perturbations in single-field inflation models based on the application
of uniform approximations. This technique is systematically improvable,
possesses controlled error bounds, and does not rely on assuming the slow-roll
parameters to be constant. We provide closed-form expressions for the power
spectra and the corresponding scalar and tensor spectral indices.Comment: 4 pages, 1 figur
Robustness of Cosmological Simulations I: Large Scale Structure
The gravitationally-driven evolution of cold dark matter dominates the
formation of structure in the Universe over a wide range of length scales.
While the longest scales can be treated by perturbation theory, a fully
quantitative understanding of nonlinear effects requires the application of
large-scale particle simulation methods. Additionally, precision predictions
for next-generation observations, such as weak gravitational lensing, can only
be obtained from numerical simulations. In this paper, we compare results from
several N-body codes using test problems and a diverse set of diagnostics,
focusing on a medium resolution regime appropriate for studying many
observationally relevant aspects of structure formation. Our conclusions are
that -- despite the use of different algorithms and error-control methodologies
-- overall, the codes yield consistent results. The agreement over a wide range
of scales for the cosmological tests is test-dependent. In the best cases, it
is at the 5% level or better, however, for other cases it can be significantly
larger than 10%. These include the halo mass function at low masses and the
mass power spectrum at small scales. While there exist explanations for most of
the discrepancies, our results point to the need for significant improvement in
N-body errors and their understanding to match the precision of near-future
observations. The simulation results, including halo catalogs, and initial
conditions used, are publicly available.Comment: 32 pages, 53 figures, data from the simulations is available at
http://t8web.lanl.gov/people/heitmann/arxiv, accepted for publication in
ApJS, several minor revisions, reference added, main conclusions unchange
Integration of sexual and reproductive health services in the provision of primary health care in the Arab States: status and a way forward.
Different approaches are used for integration of sexual and reproductive health (SRH) services at the primary health care (PHC) level, aiming at providing comprehensive services leaving no one behind. This paper aims to assess gaps in the delivery of SRH in PHC services, identifying challenges and proposing action towards universal health coverage in Arab countries. The United Nations Population Fund - Arab States Regional Office (UNFPA/ASRO), in partnership with Middle East and North Africa Health Policy Forum (HPF), launched an assessment of integration of SRH into PHC in 11 Arab countries in 2017-2018. Desk reviews were conducted, using published programme reports and national statistics. Data from country reports were compiled to present a regional assessment, challenges and recommendations. SRH services are partially integrated in PHC. Family planning is part of PHC in all countries except Libya, where only counselling is provided. Only Morocco, Tunisia and Oman provide comprehensive HIV services at PHC level. Jordan, Libya and Saudi Arabia rely mainly on referral to other facilities, while most of the integrated family planning or HIV services in Sudan, Morocco and Oman are provided within the same facilities. Action is required at the policy, organisational and operational levels. Prioritisation of services can guide the development of essential packages of SRH care. Developing the skills of the PHC workforce in SRH services and the adoption of the family medicine/general practice model can ensure proper allocation of resources. A presented regional integration framework needs further efforts for addressing the actions entailed
Improving newborn health in countries exposed to political violence: an assessment of the availability, accessibility, and distribution of neonatal health services at Palestinian hospitals
Introduction: Geopolitical segregation of Palestine has left a fragile healthcare system with an unequal distribution of services. Data from the Gaza Strip reflect an increase in infant mortality that coincided with a significant increase in neonatal mortality (12.0 to 20.3 per 1,000 live births). Objective: A baseline study was carried out to evaluate available resources in neonatal units throughout Palestine. Study Design: A cross-sectional, hospital-based study was conducted in 2017 using the World Health Organization's "Hospital care for mothers and newborn babies: quality assessment and improvement tool." Data on the main indicators were updated in 2018. Results: There were 38 neonatal units in Palestine: 27 in the West Bank, 3 in East Jerusalem, and 8 in the Gaza Strip. There was an uneven geographic distribution of incubators in relation to population and births that was more marked in the Gaza Strip; 79% of neonatal units and 75% of incubators were in the West Bank. While almost all hospitals with neonatal units accepted very and extremely low birth weight and admitted out-born neonatal cases, there was a shortage in the availability of incubators with humidifiers, high-frequency oscillatory ventilation, mechanical ventilators with humidifiers and isolation wards. There was also a considerable shortage in neonatologists, neonatal nurses, and pediatric subspecialties. Conclusion: Almost all the neonatal units accepted extremely low birth weight neonatal cases despite not being ready to receive these newborns due to considerable shortages in human resources, equipment, drugs, and essential blood tests, as well as frequent disruptions in the availability of based amenities. Together, these factors contribute to the burden of providing quality care to newborns, which is further exacerbated by the lack of referral guidelines and challenges to timely referrals resulting from Israeli measures. Ultimately, this contributes to suboptimal care for neonates and negatively impacts future health outcomes
Hyperfine Fields in an Ag/Fe Multilayer Film Investigated with 8Li beta-Detected Nuclear Magnetic Resonance
Low energy -detected nuclear magnetic resonance (-NMR) was used
to investigate the spatial dependence of the hyperfine magnetic fields induced
by Fe in the nonmagnetic Ag of an Au(40 \AA)/Ag(200 \AA)/Fe(140 \AA) (001)
magnetic multilayer (MML) grown on GaAs. The resonance lineshape in the Ag
layer shows dramatic broadening compared to intrinsic Ag. This broadening is
attributed to large induced magnetic fields in this layer by the magnetic Fe
layer. We find that the induced hyperfine field in the Ag follows a power law
decay away from the Ag/Fe interface with power , and a field
extrapolated to T at the interface.Comment: 5 pages, 4 figure. To be published in Phys. Rev.
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