18,924 research outputs found
Impact of the lipid-based nutrient supplements on prevention and treatment of childhood moderate undernutrition
Purpose: This review aims at assessing the effectiveness of LNS interventions for prevention and/or treatment of moderate acute malnutrition (MAM), stunting and other anthropometric indicators for undernutrition in children younger than 5 years.
Methodology: Eighteen clinical trials on LNS (soybased or milk-based) supplementation in children were compared with habitual diet/control or corn-soy blend (CSB). Mean changes in height for age (HAZ), weight for age (WAZ) and weight for height z-scores (WHZ) were assessed as primary outcomes. The secondary outcomes included: weight gain, height, mid upper arm circumference (MUAC), recovery from MAM, occurrence of fever, diarrhoea and cough.
Findings: The pooled estimate revealed a statistically signiïŹcant increase in WAZ (weighted mean difference [WMD] =0.09; 95%CI= 0.02, 0.15; p=0.01), WHZ (WMD=0.14; 95%CI= 0.01, 0.26; p=0.000) and improved recovery from MAM (Risk Ratio [RR] = 1.37; 95%CI= 1.14, 1.65; p=0.000) in children receiving LNS compared with control or CBS. No signiïŹcant effect was observed in HAZ (WMD=0.00;95%CI=-0.02,0.03: p=0.578). Children fed with milk-based LNS (RR=1.68; 95%CI=1.17, 2.39; p=0.005) were more likely to recover signiïŹcantly from MAM when compared with CSB.
Conclusion: Although there is evidence that LNS yield better nutritional outcomes than CSB and control, it is impossible to conclude that the milk-based LNS are superior to soy-based LNS and whether age and duration of intervention signiïŹcantly affect the effectiveness of LNS on childhood undernutrition. Further research is required before these products can be recommended at scale
A kinetic study of the photolysis of tris(2,4-pentanedionato)cobalt(III) and bis(2,4-pentanedionato)cobalt(II) in chloroform
Under 254nm irradiation in chloroform, Co(acac)3 (Hacac = 2,4-pentanedione) is converted to Co(acac)2 and then to CoCl2. The metal complex is the primary photoactive species in the photoreduction of Co(acac)3, but the photosubstitution of Co(acac)2 appears to occur primarily through absorption of light by the solvent, followed by a chain reaction in which chlorine atoms displace pentanedionyl radicals. The photosubstitution rate law is complex, and the apparent quantum yield (based on total light absorbed) varies with incident light intensity and Co(acac)2 concentration, reaching values as high as 16 under the conditions of this study. Referred only to the light absorbed by CHCL3, the highest quantum yield measured was 150. An observed partial inverse dependence of the photosubstitution rate on the initial concentration of Co(acac)2 is explained in terms of a mechanism in which the pentanedione product competes with Co(acac)2 for an intermediate
On the Feasibility of a Stop NLSP in Gravitino Dark Matter Scenarios
We analyze the possibility that the lighter stop {\tilde t_1} could be the
next-to-lightest supersymmetric particle (NLSP) in models where the gravitino
is the lightest supersymmetric particle (LSP). We do not find any possibility
for a stop NLSP in the constrained MSSM with universal input soft
supersymmetry-breaking masses at the GUT scale (CMSSM), but do find small
allowed regions in models with non-universal Higgs masses (NUHM). We discuss
the cosmological evolution of stop hadrons. Most {\tilde t_1}qq `sbaryons' and
the corresponding `antisbaryons' annihilate with conventional antibaryons and
baryons into {\tilde t_1}{\bar q} `mesinos' and the corresponding
`antimesinos', respectively, shortly after the quark-hadron transition in the
early Universe, and most mesinos and antimesinos subsequently annihilate. As a
result, insufficient metastable charged stop hadrons survive to alter Big Bang
nucleosynthesis.Comment: 31 pages, 14 figure
MECHANISMS OF DISEASE Acute Oxygen-Sensing Mechanisms
JOSEPH PRIESTLEY, ONE OF THE THREE SCIENTISTS CREDITED WITH THE discovery of oxygen, described the death of mice that were deprived of oxygen. However, he was also well aware of the toxicity of too much oxygen, stating, âFor as a candle burns much faster in dephlogisticated [oxygen enriched] than in common air, so we might live out too fast, and the animal powers be too soon exhausted in this pure kind of air. A moralist, at least, may
say, that the air which nature has provided for us is as good as we deserve.â1
In this review we examine the remarkable mechanisms by which different organs detect and respond to acute changes in oxygen tension. Specialized tissues that sense the local oxygen tension include glomus cells of the carotid body, neuroepithelial bodies in the lungs, chromaffin cells of the fetal adrenal medulla, and smooth-muscle cells of the resistance pulmonary arteries,
fetoplacental arteries, systemic arteries, and the ductus arteriosus. Together, they constitute a specialized homeostatic oxygen-sensing system. Although all tissues are sensitive to severe hypoxia, these specialized tissues respond rapidly to moderate changes in oxygen tension within the physiologic range (roughly 40 to 100 mm Hg in an adult and 20 to 40 mm Hg in a fetus)Junta de AndalucĂ
APLF (C2orf13) is a novel component of poly(ADP-ribose) signaling in mammalian cells
APLF is a novel protein of unknown function that accumulates at sites of chromosomal DNA strand breakage via forkhead-associated (FHA) domain-mediated interactions with XRCC1 and XRCC4. APLF can also accumulate at sites of chromosomal DNA strand breaks independently of the FHA domain via an unidentified mechanism that requires a highly conserved C-terminal tandem zinc finger domain. Here, we show that the zinc finger domain binds tightly to poly(ADP-ribose), a polymeric posttranslational modification synthesized transiently at sites of chromosomal damage to accelerate DNA strand break repair reactions. Protein poly(ADP-ribosyl)ation is tightly regulated and defects in either its synthesis or degradation slow global rates of chromosomal single-strand break repair. Interestingly, APLF negatively affects poly(ADP-ribosyl)ation in vitro, and this activity is dependent on its capacity to bind the polymer. In addition, transient overexpression in human A549 cells of full-length APLF or a C-terminal fragment encoding the tandem zinc finger domain greatly suppresses the appearance of poly(ADP-ribose), in a zinc finger-dependent manner. We conclude that APLF can accumulate at sites of chromosomal damage via zinc finger-mediated binding to poly(ADP-ribose) and is a novel component of poly(ADP-ribose) signaling in mammalian cells
Structural Relationship between Negative Thermal Expansion and Quartic Anharmonicity of Cubic ScF_3
Cubic scandium trifluoride (ScF_3) has a large negative thermal expansion over a wide range of temperatures. Inelastic neutron scattering experiments were performed to study the temperature dependence of the lattice dynamics of ScF3 from 7 to 750 K. The measured phonon densities of states show a large anharmonic contribution with a thermal stiffening of modes around 25 meV. Phonon calculations with first-principles methods identified the individual modes in the densities of states, and frozen phonon calculations showed that some of the modes with motions of F atoms transverse to their bond direction behave as quantum quartic oscillators. The quartic potential originates from harmonic interatomic forces in the DO_9 structure of ScF_3, and accounts for phonon stiffening with the temperature and a significant part of the negative thermal expansion
POWERLIB: SAS/IML Software for Computing Power in Multivariate Linear Models
The POWERLIB SAS/IML software provides convenient power calculations for a wide range of multivariate linear models with Gaussian errors. The software includes the Box, Geisser-Greenhouse, Huynh-Feldt, and uncorrected tests in the "univariate" approach to repeated measures (UNIREP), the Hotelling Lawley Trace, Pillai-Bartlett Trace, and Wilks Lambda tests in "multivariate" approach (MULTIREP), as well as a limited but useful range of mixed models. The familiar univariate linear model with Gaussian errors is an important special case. For estimated covariance, the software provides confidence limits for the resulting estimated power. All power and confidence limits values can be output to a SAS dataset, which can be used to easily produce plots and tables for manuscripts.
A Prototype for the PASS Permanent All Sky Survey
A prototype system for the Permanent All Sky Survey (PASS) project is
presented. PASS is a continuous photometric survey of the entire celestial
sphere with a high temporal resolution. Its major objectives are the detection
of all giant-planet transits (with periods up to some weeks) across stars up to
mag 10.5, and to deliver continuously photometry that is useful for the study
of any variable stars. The prototype is based on CCD cameras with short focal
length optics on a fixed mount. A small dome to house it at Teide Observatory,
Tenerife, is currently being constructed. A placement at the antarctic Dome C
is also being considered. The prototype will be used for a feasibility study of
PASS, to define the best observing strategies, and to perform a detailed
characterization of the capabilities and scope of the survey. Afterwards, a
first partial sky surveying will be started with it. That first survey may be
able to detect transiting planets during its first few hundred hours of
operation. It will also deliver a data set around which software modules
dealing with the various scientific objectives of PASS will be developed. The
PASS project is still in its early phase and teams interested in specific
scientific objectives, in providing technical expertise, or in participating
with own observations are invited to collaborate.Comment: Accepted for Astronomische Nachrichten (special issue for 3rd Potsdam
Thinkshop 'Robotic Astronomy' in July 2004). 4 pages, 4 fig
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