4,083 research outputs found
Estimates of the duration of untreated acute malnutrition in children from Niger.
Expected incidence of acute malnutrition is the most appropriate measure for projecting the needs of a nutritional treatment program over time in terms of staffing, food, and other treatments, but direct estimation of incidence is rarely feasible at the onset of an intervention. While incidence may be approximated as prevalence/average duration, ethical constraints preclude measurement of the duration of acute malnutrition in the absence of treatment. The authors used a compartmental model to estimate the duration of untreated moderate acute malnutrition (MAM) and severe acute malnutrition (SAM) in children aged 6-60 months. The model was informed by data from a community-based cohort of children in Niger followed from August 2006 to March 2007. Maximum likelihood estimates for the duration of untreated MAM, defined by weight-for-height z score and middle upper arm circumference, were 75-81 days and 101-116 days, respectively. The duration of untreated SAM, defined by weight-for-height z score, was 45 days. The duration of untreated MAM appears to have been shorter among children aged 6-35 months compared with those aged 36-60 months. Such estimates of the duration, and thus incidence, of untreated malnutrition can be used to improve projections of program needs and estimates of the global burden of acute malnutrition
SABOCA 350-micron and LABOCA 870-micron dust continuum imaging of IRAS 05399-0121: mapping the dust properties of a pre- and protostellar core system
We present a 350 micron APEX/SABOCA map of IRAS 05399-0121/SMM 1, which is a
dense double-core system in Orion B9. We combined these data with our previous
LABOCA 870-micron data. The spatial resolution of the new SABOCA image, ~3400
AU, is about 2.6 times better than provided by LABOCA. We also make use of
Spitzer infrared observations to characterise the star-formation activity in
the source. The source is filamentary and remains a double-core system on the
3400 AU scale probed here, where the projected separation between IRAS 05399
and SMM 1 is 0.14 pc. The broadband spectral energy distribution of IRAS 05399
suggests that it is near the Stage 0/I borderline. A visual inspection of the
Spitzer/IRAC images provides hints of a quadrupolar-like jet morphology around
IRAS 05399, supporting the possibility that it is a binary system. The
temperature map reveals warm spots towards IRAS 05399 and the southeastern tip
of the source. These features are likely to be imprints of protostellar or
shock heating, while external heating could be provided by the nearby high-mass
star-forming region NGC 2024. A simple analysis suggests that the density
profile at the position of SMM 1 has the form ~r^-(2.3_{-0.9}^{+2.2}). The
source splitting into two subcores along the long axis can be explained by
cylindrical Jeans-type fragmentation but the steepness of the density profile
is shallower than what is expected for an isothermal cylinder. The difference
between the evolutionary stages of IRAS 05399 (protostellar) and SMM 1
(starless) suggests that the former has experienced a phase of rapid mass
accretion, supported by the very long outflow it drives. The protostellar jet
from IRAS 05399 might have influenced the nearby core SMM 1.Comment: A&A, in press; 14 pages, 7 figures, 3 tables; very minor language
corrections+revised arXiv abstrac
Magnetic Geometry and the Confinement of Electrically Conducting Plasmas
We develop an effective field theory approach to inspect the electromagnetic
interactions in an electrically neutral plasma, with an equal number of
negative and positive charge carriers. We argue that the static equilibrium
configurations within the plasma are topologically stable solitons, that
describe knotted and linked fluxtubes of helical magnetic fields.Comment: 9 pages 1 ps-figur
Hard Diffraction From Quasi-Elastic Dipole Scattering
The contribution to diffraction dissociation of virtual photons due to
quasi-elastic scattering of the - component is calculated in the
framework of the QCD dipole picture. Both longitudinal and transverse
components of the cross-section are given. It is shown that, at fixed mass of
the diffractively produced system, quantum mechanical interference plays an
important r\^ ole. Phenomenological consequences are discussed.Comment: latex + now: 4 encapsulated poscript figure
Characterizing degradation of palm swamp peatlands from space and on the ground: an exploratory study in the Peruvian Amazon
Peru has the fourth largest area of peatlands in the Tropics. Its most representative land cover on peat is a Mauritia flexuosa dominated palm swamp (thereafter called dense PS), which has been under human pressure over decades due to the high demand for the M. flexuosa fruit often collected by cutting down the entire palm. Degradation of these carbon dense forests can substantially affect emissions of greenhouse gases and contribute to climate change. The first objective of this research was to assess the impact of dense PS degradation on forest structure and biomass carbon stocks. The second one was to explore the potential of mapping the distribution of dense PS with different degradation levels using remote sensing data and methods. Biomass stocks were measured in 0.25 ha plots established in areas of dense PS with low (n = 2 plots), medium (n = 2) and high degradation (n = 4). We combined field and remote sensing data from the satellites Landsat TM and ALOS/PALSAR to discriminate between areas typifying dense PS with low, medium and high degradation and terra firme, restinga and mixed PS (not M. flexuosa dominated) forests. For this we used a Random Forest machine learning classification algorithm. Results suggest a shift in forest composition from palm to woody tree dominated forest following degradation. We also found that human intervention in dense PS translates into significant reductions in tree carbon stocks with initial (above and below-ground) biomass stocks (135.4 ± 4.8 Mg C ha−1) decreased by 11 and 17% following medium and high degradation. The remote sensing analysis indicates a high separability between dense PS with low degradation from all other categories. Dense PS with medium and high degradation were highly separable from most categories except for restinga forests and mixed PS. Results also showed that data from both active and passive remote sensing sensors are important for the mapping of dense PS degradation. Overall land cover classification accuracy was high (91%). Results from this pilot analysis are encouraging to further explore the use of remote sensing data and methods for monitoring dense PS degradation at broader scales in the Peruvian Amazon. Providing precise estimates on the spatial extent of dense PS degradation and on biomass and peat derived emissions is required for assessing national emissions from forest degradation in Peru and is essential for supporting initiatives aiming at reducing degradation activities
Polymerase Chain Reaction Assay With Urine Specimens in the Diagnosis of Acute Chlamydia trachomatis Infection in Women
Objective: The purpose of this study was to evaluate the benefits achievable by Amplicor polymerase
chain reaction (PCR) (F. Hoffmann-LaRoche Ltd., Basel, Switzerland) with urine specimens
in addition to PACE 2 (Gen-Probe, Inc., San Diego, California) assay with cervical swab specimens
in the diagnosis of Chlamydia trachomatis in women
Additions to Dendrodacrys and outline of taxa with branched hyphidia in Dacrymycetes (Basidiomycota)
The genus Dendrodacrys is a monophyletic group that belongs to Dacrymycetes (Agaricomycotina, Basidiomycota) and accommodates species distinguished by strongly branched hyphidia in combination with 3-septate basidiospores. While the original circumscription mainly treated European taxa, here we shift the focus to tropical and sub-tropical material and uncover wider variation in morphology within Dendrodacrys. Still united by hyphidia shape and basidiospore septation, the genus is expanded with 10 taxa having pustulate, cerebriform, or stipitate basidiocarps of yellow to dark brown colours, cylindrical to ovoid basidiospores, and hyphal septa with or without clamps. Monophyly of the amended Dendrodacrys is confirmed with a phylogeny based on six markers (SSU, ITS, LSU, TEF1-α, RPB1, and RPB2). As a result, we describe two new species (De. laetum and De. rigoratum), transfer three existing species to Dendrodacrys (De. brasiliense, De. dendrocalami, and De. pezizoideum), and raise one variety to the species level (De. kennedyae ≡ Dacrymyces enatus var. macrosporus). In addition, we provide descriptions for the earlier combined De. paraphysatum and four new informal taxa. Lastly, we present illustrations, a character table, and an identification key that addresses all known dacrymycetes with branched hyphidia.Peer reviewe
Hadron-nucleon Total Cross Section Fluctuations from Hadron-nucleus Total Cross Sections
The extent to which information about fluctuations in hadron-nucleon total
cross sections in the frozen approximation can be extracted from very high
energy hadron-nucleus total cross section measurements for a range of heavy
nuclei is discussed. The corrections to the predictions of Glauber theory due
to these fluctuations are calculated for several models for the distribution
functions, and differences of the order of 50 mb are found for heavy nuclei.
The generating function for the moments of the hadron-nucleon cross section
distributions can be approximately determined from the derivatives of the
hadron-nucleus total cross sections with respect to the nuclear geometric cross
section. The argument of the generating function, however, it limited to the
maximum value of a dimensionless thickness function obtained at zero impact
parameter for the heaviest nuclear targets: about 1.8 for pions and 3.0 for
nucleons.Comment: 14 pages, revtex 3.0, 4 figures available upon reques
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