19,280 research outputs found
Small area estimation of general parameters with application to poverty indicators: A hierarchical Bayes approach
Poverty maps are used to aid important political decisions such as allocation
of development funds by governments and international organizations. Those
decisions should be based on the most accurate poverty figures. However, often
reliable poverty figures are not available at fine geographical levels or for
particular risk population subgroups due to the sample size limitation of
current national surveys. These surveys cannot cover adequately all the desired
areas or population subgroups and, therefore, models relating the different
areas are needed to 'borrow strength" from area to area. In particular, the
Spanish Survey on Income and Living Conditions (SILC) produces national poverty
estimates but cannot provide poverty estimates by Spanish provinces due to the
poor precision of direct estimates, which use only the province specific data.
It also raises the ethical question of whether poverty is more severe for women
than for men in a given province. We develop a hierarchical Bayes (HB) approach
for poverty mapping in Spanish provinces by gender that overcomes the small
province sample size problem of the SILC. The proposed approach has a wide
scope of application because it can be used to estimate general nonlinear
parameters. We use a Bayesian version of the nested error regression model in
which Markov chain Monte Carlo procedures and the convergence monitoring
therein are avoided. A simulation study reveals good frequentist properties of
the HB approach. The resulting poverty maps indicate that poverty, both in
frequency and intensity, is localized mostly in the southern and western
provinces and it is more acute for women than for men in most of the provinces.Comment: Published in at http://dx.doi.org/10.1214/13-AOAS702 the Annals of
Applied Statistics (http://www.imstat.org/aoas/) by the Institute of
Mathematical Statistics (http://www.imstat.org
Bacterial Active Community Cycling in Response to Solar Radiation and Their Influence on Nutrient Changes in a High-Altitude Wetland
Indexación: Web of Science; Scopus.Microbial communities inhabiting high-altitude spring ecosystems are subjected to extreme changes in solar irradiance and temperature throughout the diel cycle. Here, using 16S rRNA gene tag pyrosequencing (cDNA) we determined the composition of actively transcribing bacteria from spring waters experimentally exposed through the day (morning, noon, and afternoon) to variable levels of solar radiation and light quality, and evaluated their influence on nutrient recycling. Solar irradiance, temperature, and changes in nutrient dynamics were associated with changes in the active bacterial community structure, predominantly by Cyanobacteria, Verrucomicrobia, Proteobacteria, and 35 other Phyla, including the recently described Candidate Phyla Radiation (e.g., Parcubacteria, Gracilibacteria, OP3, TM6, SR1). Diversity increased at noon, when the highest irradiances were measured (3.3-3.9 H', 1125 W m(-2)) compared to morning and afternoon (0.6-2.8 H'). This shift was associated with a decrease in the contribution to pyrolibraries by Cyanobacteria and an increase of Proteobacteria and other initially low frequently and rare bacteria phyla (< 0.5%) in the pyrolibraries. A potential increase in the activity of Cyanobacteria and other phototrophic groups, e.g., Rhodobacterales, was observed and associated with UVR, suggesting the presence of photo activated repair mechanisms to resist high levels of solar radiation. In addition, the percentage contribution of cyanobacterial sequences in the afternoon was similar to those recorded in the morning. The shifts in the contribution by Cyanobacteria also influenced the rate of change in nitrate, nitrite, and phosphate, highlighted by a high level of nitrate accumulation during hours of high radiation and temperature associated with nitrifying bacteria activity. We did not detect ammonia or nitrite oxidizing bacteria in situ, but both functional groups (Nitrosomona and Nitrospira) appeared mainly in pyrolibraries generated from dark incubations. In total, our results reveal that both the structure and the diversity of the active bacteria community was extremely dynamic through the day, and showed marked shifts in composition that influenced nutrient recycling, highlighting how abiotic variation affects potential ecosystem functioning.http://journal.frontiersin.org/article/10.3389/fmicb.2016.01823/ful
Normalizing the Topic of Menstruation through the #Prideintheperiod Campaign
Since shame is embedded in the discourse of menstruation, the researcher chose to naturalize the conversation of menstruation since it is an innate bodily function that menstruators should not be embarrassed about. Granted the improper sex education and the continuous genderization of menstruation promoted societal menstrual shame, the researcher found that both genders needed to be re-educated on menstrual stigma and be included in menstruation conversations. Through a needs assessment, the researcher created five campaign messages that allowed participants to see varying perspectives on periods. Both a questionnaire and a survey evaluated if the campaign changed the participants’ perceptions of menstruation. The campaign results vocalized that participants previously viewed menstruation as ‘embarrassing’ based on being uninformed of the other gender’s relationship to menstruation. To normalize menstruation, participants stressed that education and conversations need to value both genders’ perspectives and display menstruation realistically
Late time tails of the massive vector field in a black hole background
We investigate the late-time behavior of the massive vector field in the
background of the Schwarzschild and Schwarzschild-de Sitter black holes. For
Schwarzschild black hole, at intermediately late times the massive vector field
is represented by three functions with different decay law , ,
, while at asymptotically late times
the decay law is universal, and does not
depend on the multipole number . Together with previous study of massive
scalar and Dirac fields where the same asymptotically late-time decay law was
found, it means, that the asymptotically late-time decay law \emph{does not depend} also \emph{on the spin} of the field under
consideration. For Schwarzschild-de Sitter black holes it is observed two
different regimes in the late-time decay of perturbations: non-oscillatory
exponential damping for small values of and oscillatory quasinormal mode
decay for high enough . Numerical and analytical results are found for these
quasinormal frequencies.Comment: one author and new material are adde
Bulk and surface magnetoinductive breathers in binary metamaterials
We study theoretically the existence of bulk and surface discrete breathers
in a one-dimensional magnetic metamaterial comprised of a periodic binary array
of split-ring resonators. The two types of resonators differ in the size of
their slits and this leads to different resonant frequencies. In the framework
of the rotating-wave approximation (RWA) we construct several types of breather
excitations for both the energy-conserved and the dissipative-driven systems by
continuation of trivial breather solutions from the anticontinuous limit to
finite couplings. Numerically-exact computations that integrate the full model
equations confirm the quality of the RWA results. Moreover, it is demonstrated
that discrete breathers can spontaneously appear in the dissipative-driven
system as a results of a fundamental instability.Comment: 10 pages, 16 figure
Photo-induced volume changes in selenium. Tight-binding molecular dynamics study
Tight-binding molecular dynamics simulations of photo-excitations in small Se
clusters (isolated Se ring and helical Se chain) and glassy Se networks
(containing 162 atoms) were carried out in order to analyse the photo induced
instability inside the amorphous selenium. In the cluster systems after taking
an electron from the highest occupied molecular orbital to the lowest
unoccupied molecular orbital a bond breaking occurs. In the glassy networks
photoinduced volume expansion was observed and at the same time the number of
coordination defects changed significantly due to illumination
Scalar field evolution in Gauss-Bonnet black holes
It is presented a thorough analysis of scalar perturbations in the background
of Gauss-Bonnet, Gauss-Bonnet-de Sitter and Gauss-Bonnet-anti-de Sitter black
hole spacetimes. The perturbations are considered both in frequency and time
domain. The dependence of the scalar field evolution on the values of the
cosmological constant and the Gauss-Bonnet coupling is
investigated. For Gauss-Bonnet and Gauss-Bonnet-de Sitter black holes, at
asymptotically late times either power-law or exponential tails dominate, while
for Gauss-Bonnet-anti-de Sitter black hole, the quasinormal modes govern the
scalar field decay at all times. The power-law tails at asymptotically late
times for odd-dimensional Gauss-Bonnet black holes does not depend on ,
even though the black hole metric contains as a new parameter. The
corrections to quasinormal spectrum due to Gauss-Bonnet coupling is not small
and should not be neglected. For the limit of near extremal value of the
(positive) cosmological constant and pure de Sitter and anti-de Sitter modes in
Gauss-Bonnet gravity we have found analytical expressions.Comment: 10 pages, to be published in Phys. Rev.
Effect of nonlinearity on the dynamics of a particle in dc field-induced systems
Dynamics of a particle in a perfect chain with one nonlinear impurity and in
a perfect nonlinear chain under the action of dc field is studied numerically.
The nonlinearity appears due to the coupling of the electronic motion to
optical oscillators which are treated in adiabatic approximation.
We study for both the low and high values of field strength. Three different
range of nonlinearity is obtained where the dynamics is different. In low and
intermediate range of nonlinearity, it reduces the localization. In fact in the
intermediate range subdiffusive behavior in the perfect nonlinear chain is
obtained for a long time. In all the cases a critical value of nonlinear
strength exists where self-trapping transition takes place. This critical value
depends on the system and the field strength. Beyond the self-trapping
transition nonlinearity enhances the localization.Comment: 9 pages, Revtex, 6 ps figures include
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