93 research outputs found
Cassava intake and vitamin A status among women and preschool children in Akwa-Ibom, Nigeria
Background
As part of the HarvestPlus provitamin A-biofortified cassava program in Nigeria we con-
ducted a survey to determine the cassava intake and prevalence of vitamin A deficiency
among children 6-59 months and women of childbearing age in the state of Akwa Ibom.
Methods
A cluster-randomized cross-sectional survey was conducted in 2011 in Akwa Ibom, Nigeria.
The usual food and nutrient intakes were estimated using a multi-pass 24-hour recall with
repeated recall on a subsample. Blood samples of children and women were collected to
analyze for serum retinol, serum ferritin, and acute phase proteins as indicators of infection.
Vitamin A deficiency was defined as serum retinol
<
0.70
?
mol/L adjusted for infection.
Results
A total of 587 households of a mother-child dyad participated in the dietary intake assess-
ment. Cassava was very widely consumed in Akwa Ibom, mainly as
gari
or
foofoo
. Daily
cassava consumption frequency was 92% and 95% among children and women, respec-
tively. Mean (
±
SD) cassava intake (expressed as raw fresh weight) was 348
±
317 grams/
day among children and 940
±
777 grams/day among women. Intakes of most micronutri-
ents appeared to be adequate with the exception of calcium. Median vitamin A intake was
very high both for children (1038
?
g RAE/day) and women (2441
?
g RAE/day). Red palm oil
and dark green leafy vegetables were the main sources of vitamin A in the diet, with red
palm oil alone contributing almost 60% of vitamin A intake in women and children. Preva-
lence of vitamin A deficiency ranged from moderate (16.9 %) among children to virtually
non-existent (3.4 %) among womenConclusion
Consumption of cassava and vitamin A intake was high among women and children in
Akwa Ibom with a prevalence of vitamin A deficiency ranging from moderate in children to
non-existent among women. The provitamin A biofortified cassava and other vitamin A inter-
ventions should focus dissemination in states where red palm oil is not widely consumed.Background
As part of the HarvestPlus provitamin A-biofortified cassava program in Nigeria we con-
ducted a survey to determine the cassava intake and prevalence of vitamin A deficiency
among children 6-59 months and women of childbearing age in the state of Akwa Ibom.
Methods
A cluster-randomized cross-sectional survey was conducted in 2011 in Akwa Ibom, Nigeria.
The usual food and nutrient intakes were estimated using a multi-pass 24-hour recall with
repeated recall on a subsample. Blood samples of children and women were collected to
analyze for serum retinol, serum ferritin, and acute phase proteins as indicators of infection.
Vitamin A deficiency was defined as serum retinol
<
0.70
?
mol/L adjusted for infection.
Results
A total of 587 households of a mother-child dyad participated in the dietary intake assess-
ment. Cassava was very widely consumed in Akwa Ibom, mainly as
gari
or
foofoo
. Daily
cassava consumption frequency was 92% and 95% among children and women, respec-
tively. Mean (
±
SD) cassava intake (expressed as raw fresh weight) was 348
±
317 grams/
day among children and 940
±
777 grams/day among women. Intakes of most micronutri-
ents appeared to be adequate with the exception of calcium. Median vitamin A intake was
very high both for children (1038
?
g RAE/day) and women (2441
?
g RAE/day). Red palm oil
and dark green leafy vegetables were the main sources of vitamin A in the diet, with red
palm oil alone contributing almost 60% of vitamin A intake in women and children. Preva-
lence of vitamin A deficiency ranged from moderate (16.9 %) among children to virtually
non-existent (3.4 %) among womenConclusion
Consumption of cassava and vitamin A intake was high among women and children in
Akwa Ibom with a prevalence of vitamin A deficiency ranging from moderate in children to
non-existent among women. The provitamin A biofortified cassava and other vitamin A inter-
ventions should focus dissemination in states where red palm oil is not widely consumed
Synthesis of silver nanoparticles using a biosurfactant produced in low-cost medium as stabilizing agent
Background: A biosurfactant produced by Pseudomonas aeruginosa
cultivated in a low-cost medium formulated with 2.5% vegetable oil
refinery residue and 2.5% corn steep liquor and distilled water was
employed to stabilize silver nanoparticles in the liquid phase. The
particleswere initially synthesized using NaBH4 as reducing agent in
biosurfactant reverse micelles and were extracted from the micellar
solution to disperse in heptane. Results: A silver particle size in the
range of 1.13 nmwas observed. The UV\u2013vis absorption spectra
proposed that silver nanoparticles could be formed in the reverse
micelles and relatively stabilized for at least 3 months without
passivator addition. The Transmission Electron Microscope (TEM) shows
that the silver nanoparticles are of spherical form and relatively
uniform. Conclusions: This process provided a simpler route for
nanoparticle synthesis compared to existing systems using whole
organisms or partially purified biological extracts, showing that the
low-cost biosurfactant can be used for nanoparticle synthesis as a
non-toxic and biodegradable stabilizing agent
Atmospheric effects on extensive air showers observed with the Surface Detector of the Pierre Auger Observatory
Atmospheric parameters, such as pressure (P), temperature (T) and density,
affect the development of extensive air showers initiated by energetic cosmic
rays. We have studied the impact of atmospheric variations on extensive air
showers by means of the surface detector of the Pierre Auger Observatory. The
rate of events shows a ~10% seasonal modulation and ~2% diurnal one. We find
that the observed behaviour is explained by a model including the effects
associated with the variations of pressure and density. The former affects the
longitudinal development of air showers while the latter influences the Moliere
radius and hence the lateral distribution of the shower particles. The model is
validated with full simulations of extensive air showers using atmospheric
profiles measured at the site of the Pierre Auger Observatory.Comment: 24 pages, 9 figures, accepted for publication in Astroparticle
Physic
Update on the correlation of the highest energy cosmic rays with nearby extragalactic matter
Data collected by the Pierre Auger Observatory through 31 August 2007 showed
evidence for anisotropy in the arrival directions of cosmic rays above the
Greisen-Zatsepin-Kuz'min energy threshold, \nobreak{eV}. The
anisotropy was measured by the fraction of arrival directions that are less
than from the position of an active galactic nucleus within 75 Mpc
(using the V\'eron-Cetty and V\'eron catalog). An updated
measurement of this fraction is reported here using the arrival directions of
cosmic rays recorded above the same energy threshold through 31 December 2009.
The number of arrival directions has increased from 27 to 69, allowing a more
precise measurement. The correlating fraction is , compared
with expected for isotropic cosmic rays. This is down from the early
estimate of . The enlarged set of arrival directions is
examined also in relation to other populations of nearby extragalactic objects:
galaxies in the 2 Microns All Sky Survey and active galactic nuclei detected in
hard X-rays by the Swift Burst Alert Telescope. A celestial region around the
position of the radiogalaxy Cen A has the largest excess of arrival directions
relative to isotropic expectations. The 2-point autocorrelation function is
shown for the enlarged set of arrival directions and compared to the isotropic
expectation.Comment: Accepted for publication in Astroparticle Physics on 31 August 201
The Fluorescence Detector of the Pierre Auger Observatory
The Pierre Auger Observatory is a hybrid detector for ultra-high energy
cosmic rays. It combines a surface array to measure secondary particles at
ground level together with a fluorescence detector to measure the development
of air showers in the atmosphere above the array. The fluorescence detector
comprises 24 large telescopes specialized for measuring the nitrogen
fluorescence caused by charged particles of cosmic ray air showers. In this
paper we describe the components of the fluorescence detector including its
optical system, the design of the camera, the electronics, and the systems for
relative and absolute calibration. We also discuss the operation and the
monitoring of the detector. Finally, we evaluate the detector performance and
precision of shower reconstructions.Comment: 53 pages. Submitted to Nuclear Instruments and Methods in Physics
Research Section
Advanced functionality for radio analysis in the Offline software framework of the Pierre Auger Observatory
The advent of the Auger Engineering Radio Array (AERA) necessitates the
development of a powerful framework for the analysis of radio measurements of
cosmic ray air showers. As AERA performs "radio-hybrid" measurements of air
shower radio emission in coincidence with the surface particle detectors and
fluorescence telescopes of the Pierre Auger Observatory, the radio analysis
functionality had to be incorporated in the existing hybrid analysis solutions
for fluoresence and surface detector data. This goal has been achieved in a
natural way by extending the existing Auger Offline software framework with
radio functionality. In this article, we lay out the design, highlights and
features of the radio extension implemented in the Auger Offline framework. Its
functionality has achieved a high degree of sophistication and offers advanced
features such as vectorial reconstruction of the electric field, advanced
signal processing algorithms, a transparent and efficient handling of FFTs, a
very detailed simulation of detector effects, and the read-in of multiple data
formats including data from various radio simulation codes. The source code of
this radio functionality can be made available to interested parties on
request.Comment: accepted for publication in NIM A, 13 pages, minor corrections to
author list and references in v
Search for First Harmonic Modulation in the Right Ascension Distribution of Cosmic Rays Detected at the Pierre Auger Observatory
We present the results of searches for dipolar-type anisotropies in different
energy ranges above eV with the surface detector array of
the Pierre Auger Observatory, reporting on both the phase and the amplitude
measurements of the first harmonic modulation in the right-ascension
distribution. Upper limits on the amplitudes are obtained, which provide the
most stringent bounds at present, being below 2% at 99% for EeV
energies. We also compare our results to those of previous experiments as well
as with some theoretical expectations.Comment: 28 pages, 11 figure
SELNET clinical practice guidelines for bone sarcoma
Bone sarcoma are infrequent diseases, representing < 0.2% of all adult neoplasms. A multidisciplinary management within reference centers for sarcoma, with discussion of the diagnostic and therapeutic strategies within an expert multidisciplinary tumour board, is essential for these patients, given its heterogeneity and low frequency. This approach leads to an improvement in patient's outcome, as demonstrated in several studies. The Sarcoma European Latin-American Network (SELNET), aims to improve clinical outcome in sarcoma care, with a special focus in Latin-American countries. These Clinical Practice Guidelines (CPG) have been developed and agreed by a multidisciplinary expert group (including medical and radiation oncologist, surgical oncologist, orthopaedic surgeons, radiologist, pathologist, molecular biologist and representatives of patients advocacy groups) of the SELNET consortium, and are conceived to provide the standard approach to diagnosis, treatment and follow-up of bone sarcoma patients in the Latin-American context
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