14,825 research outputs found
Interpretation of Solar Magnetic Field Strength Observations
This study based on longitudinal Zeeman effect magnetograms and spectral line
scans investigates the dependence of solar surface magnetic fields on the
spectral line used and the way the line is sampled in order to estimate the
magnetic flux emerging above the solar atmosphere and penetrating to the corona
from magnetograms of the Mt. Wilson 150-foot tower synoptic program (MWO). We
have compared the synoptic program \lambda5250\AA line of Fe I to the line of
Fe I at \lambda5233\AA since this latter line has a broad shape with a profile
that is nearly linear over a large portion of its wings. The present study uses
five pairs of sampling points on the \AA line. We recommend
adoption of the field determined with a line bisector method with a sampling
point as close as possible to the line core as the best estimate of the
emergent photospheric flux. The combination of the line profile measurements
and the cross-correlation of fields measured simultaneously with \lambda5250\AA
and \lambda5233\AA yields a formula for the scale factor 1/\delta that
multiplies the MWO synoptic magnetic fields. The new calibration shows that
magnetic fields measured by the MDI system on the SOHO spacecraft are equal to
0.619+/-0.018 times the true value at a center-to-limb position 30 deg. Berger
and Lites (2003) found this factor to be 0.64+/-0.013 based on a comparison the
the Advanced Stokes Polarimeter.Comment: Accepted by Solar Physic
Surveillance and democracy:Sympathies and antagonisms
This chapter offers an introduction to the research carried out by a multidisciplinary group of researchers focusing on key surveillance practices in Europe. The chapter provides information about the theoretical approach and the empirical foci of this multi-sited research, done in the framework of the IRISS (Increasing Resilience in Surveillance Societies) project, funded by the European Union 7th Framework Programme (project number 290492)
Role of the exchange and correlation potential into calculating the x-ray absorption spectra of half-metallic alloys: the case of Mn and Cu K-edge XANES in CuMnM (M = Al, Sn, In) Heusler alloys
This work reports a theoretical study of the x-ray absorption near-edge
structure spectra at both the Cu and the Mn K-edge in several CuMnM (M= Al,
Sn and In) Heusler alloys. Our results show that {\it ab-initio} single-channel
multiple-scattering calculations are able of reproducing the experimental
spectra. Moreover, an extensive discussion is presented concerning the role of
the final state potential needed to reproduce the experimental data of these
half-metallic alloys. In particular, the effects of the cluster-size and of the
exchange and correlation potential needed in reproducing all the experimental
XANES features are discussed.Comment: 15 pages, 5 figure
Community Group-Based Models of Medication Delivery: Applicability to Cardiovascular Diseases.
The rising global burden of chronic non-communicable diseases (NCDs) has put a strain on healthcare systems globally, especially in low- and middle-income countries, which have seen disproportionate mortality rates due to non-communicable diseases. These deaths are in part due to challenges with medication adherence, which are compounded by lack of access to medication and weak community support systems. This paper aims to propose a potential solution using models of service delivery in HIV/AIDS, given the many similarities between NCD and HIV/AIDS. Models that have been particularly effective in HIV/AIDS are the community-based peer-support medication delivery groups: medication adherence clubs and community antiretroviral therapy (ART) groups. The positive outcomes from these models, including improved medication adherence and patient satisfaction, provide evidence for their potential success when applied to non-communicable diseases, particularly hypertension and cardiovascular disease
Population Genetic Structuring in Opisthorchis viverrini over Various Spatial Scales in Thailand and Lao PDR
Khon Kaen Province in northeast Thailand is known as a hot spot for opisthorchiasis in Southeast Asia. Preliminary allozyme and mitochondrial DNA haplotype data from within one endemic district in this Province (Ban Phai), indicated substantial genetic variability within Opisthorchis viverrini. Here, we used microsatellite DNA analyses to examine the genetic diversity and population structure of O. viverrini from four geographically close localities in Khon Kaen Province. Genotyping based on 12 microsatellite loci yielded a mean number of alleles per locus that ranged from 2.83 to 3.7 with an expected heterozygosity in Hardy-Weinberg equilibrium of 0.44-0.56. Assessment of population structure by pairwise F(ST) analysis showed inter-population differentiation (P<0.05) which indicates population substructuring between these localities. Unique alleles were found in three of four localities with the highest number observed per locality being three. Our results highlight the existence of genetic diversity and population substructuring in O. viverrini over a small spatial scale which is similar to that found at a larger scale. This provides the basis for the investigation of the role of parasite genetic diversity and differentiation in transmission dynamics and control of O. viverrini
Anomalous Magnetic Properties in Ni50Mn35In15
We present here a comprehensive investigation of the magnetic ordering in
Ni50Mn35In15 composition. A concomitant first order martensitic transition and
the magnetic ordering occurring in this off-stoichiometric Heusler compound at
room temperature signifies the multifunctional character of this magnetic shape
memory alloy. Unusual features are observed in the dependence of the
magnetization on temperature that can be ascribed to a frustrated magnetic
order. It is compelling to ascribe these features to the cluster type
description that may arise due to inhomogeneity in the distribution of magnetic
atoms. However, evidences are presented from our ac susceptibility, electrical
resistivity and dc magnetization studies that there exists a competing
ferromagnetic and antiferromagnetic order within crystal structure of this
system. We show that excess Mn atoms that substitute the In atoms have a
crucial bearing on the magnetic order of this compound. These excess Mn atoms
are antiferromagnetically aligned to the other Mn, which explains the peculiar
dependence of magnetization on temperature.Comment: Accepted in J. Phys. D.:Appl. Physic
- …