1,290 research outputs found
Efficacy of iron-biofortified crops
Biofortification aims to increase the content of micronutrients in staple crops without sacrificing agronomic yield, making the new varieties attractive to farmers. Food staples that provide a major energy supply in low- and middle-income populations are the primary focus. The low genetic variability of iron in the germplasm of most cereal grains is a major obstacle on the path towards nutritional impact with these crops, which is solvable only by turning to transgenic approaches. However, biofortified varieties of common beans and pearl millet have been developed successfully and made available with iron contents as high as 100 mg/kg and 80 mg/kg, respectively, two to five times greater than the levels in the regular varieties. This brief review summarizes the research to date on the bioavailability and efficacy of iron-biofortified crops, highlights their potential and limitations, and discusses the way forward with multiple biofortified crop approaches suitable for diverse cultures and socio-economic milieu. Like post-harvest iron fortification, these biofortified combinations might provide enough iron to meet the additional iron needs of many iron deficient women and children that are not covered at present by their traditional diets.Keywords: Biofortification, Iron, Beans, Pearl millet, Rice, Polyphenols, Phytic acid, Anemia, Efficacy, Nutrition-Agriculture linkage
AIDS in the Netherlands, clinical and microbiological data in 36 cases
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Electronic transport in EuB
EuB is a magnetic semiconductor in which defects introduce charge
carriers into the conduction band with the Fermi energy varying with
temperature and magnetic field. We present experimental and theoretical work on
the electronic magnetotransport in single-crystalline EuB. Magnetization,
magnetoresistance and Hall effect data were recorded at temperatures between 2
and 300 K and in magnetic fields up to 5.5 T. The negative magnetoresistance is
well reproduced by a model in which the spin disorder scattering is reduced by
the applied magnetic field. The Hall effect can be separated into an ordinary
and an anomalous part. At 20 K the latter accounts for half of the observed
Hall voltage, and its importance decreases rapidly with increasing temperature.
As for Gd and its compounds, where the rare-earth ion adopts the same Hund's
rule ground state as Eu in EuB, the standard antisymmetric
scattering mechanisms underestimate the of this contribution by several
orders of magnitude, while reproducing its almost perfectly. Well below
the bulk ferromagnetic ordering at = 12.5 K, a two-band model
successfully describes the magnetotransport. Our description is consistent with
published de Haas van Alphen, optical reflectivity, angular-resolved
photoemission, and soft X-ray emission as well as absorption data, but requires
a new interpretation for the gap feature deduced from the latter two
experiments.Comment: 35 pages, 12 figures, submitted to PR
Dietary patterns and changes in frailty status: the Rotterdam study
Purpose: To determine the associations between a priori and a posteriori derived dietary patterns and a general state of health, measured as the accumulation of deficits in a frailty index. Methods: Cross-sectional and longitudinal analysis embedded in the population-based Rotterdam Study (n = 2632) aged 45 years. Diet was assessed at baseline (year 2006) using food frequency questionnaires. Dietary patterns were defined a priori using an existing index reflecting adherence to national dietary guidelines and a posteriori using principal component analysis. A frailty index was composed of 38 health deficits and measured at baseline and follow-up (4 years later). Linear regression analyses were performed using adherence to each of the dietary patterns as exposure and the frailty index as outcome (all in Z-scores). Results: Adherence to the national dietary guidelines was associated with lower frailty at baseline (β â0.05, 95% CI â0.08, â0.02). Additionally, high adherence was associated with lower frailty scores over time (β â0.08, 95% CI â0.12, â0.04). The PCA revealed three dietary patterns that we named a âTraditionalâ pattern, high in legumes, eggs and savory snacks; a âCarnivoreâ pattern, high in meat and poultry; and a âHealth Consciousâ pattern, high in whole grain products, vegetables and fruit. In the cross-sectional analyses adherence to these patterns was not associated with frailty. However, adherence to the âTraditionalâ pattern was associated with less frailty over time (β â0.09, 95% CI â0.14, â0.05). Conclusion: No associations were found for adherence to a âhealthyâ pattern or âCarnivoreâ pattern. However, Even in a population that is relatively young and healthy, adherence to dietary guidelines or adherence to the Traditional pattern could help to prevent, delay or reverse frailty levels
Effects of LED device size on UV-C short-range LoS optical wireless communication
We report systematic investigation of the device-size-dependent performance of ultraviolet C (UV-C) light emitting diodes (LEDs) for optical wireless communication (OWC). Utilizing 273 nm-wavelength devices with diameters in the range of 40 Ο m to 300 Ο m, the size-dependent electrical, optical and frequency response characteristics of AlGaN UV-C LEDs are analyzed. As the junction area scales down, the smaller devices present lower optical power but faster modulation speed. Based on a 1-m point-to-point OWC system, this study further explores the LED size effect on the communication performance including channel gain, signal-to-noise ratio (SNR), theoretical Shannon capacity, achievable data transmission rate, relevant ratio, and spectral efficiency (SE). The system employing a 60 Ο m diameter (micro) LED transmitter achieves the highest average SNR and SE accompanying a data transmission rate up to a 5.53 Gbps at the forward error correction floor of 3.8 Ă10â3 . These results suggest an optimal device diameter of âźÂ 60 Ο m for further development of high-performance UV-C short-range line-of-sight (LoS) OWC
Hundred-meter Gb/s deep ultraviolet wireless communications using AlGaN micro-LEDs
We demonstrate the use of deep ultraviolet (DUV) micro-LEDs for long-distance line-of-sight optical wireless communications. With a single 285nm-emitting micro-LED, we have respectively achieved data rates greater than 6.5 Gb/s at a distance of 10m and 4 Gb/s at 60m. Moreover, we obtained >1Gb/s data rates at a distance of 116 m. To our knowledge, these results are the highest data rates at such distances thus far reported using deep DUV micro-LEDs and the first demonstration of Gb/s communication at >100m using any micro-LED-based transmitter
GaN-based series hybrid LED array : a dual-function light source with illumination and high-speed visible light communication capabilities
We propose and demonstrate a GaN-based series-driven hybrid light emitting diode (SH-LED) device in which broad-area and micro-LED components are interconnected for simultaneous illumination and high-speed visible light communication (VLC) applications. Through theoretical analysis based on an equivalent electrical circuit model and characterization from a fabricated exemplar device with blue emission, it is shown that SH-LEDs combine the advantages of broad- and micro-LED components by offering high direct-current (DC) optical power output and a fast frequency response. The application of this device to VLC is demonstrated through both the point-to-point and 9o divergence-angle coverage systems at 3 m transmission distance adopting a DC-biased optical-orthogonal frequency-division multiplexing modulation scheme. Compared with a point-to-point system using a single micro-LED, the one employing an SH-LED achieves the same data transmission rate of 3.39 Gbps at forward error correction (FEC) floor of 3.8Ă10-3, but the received DC optical power is improved by over 3 times. For the area coverage system, up to 1.56 Gbps data transmission rates at a FEC floor of 3.8Ă10-3 are accomplished by using this device, associated with over 4 times higher received DC optical power compared with the one using a single micro-LED
Implementation of a pharmacogenomics consult service to support the INGENIOUS trial
Hospital systems increasingly utilize pharmacogenomic testing to inform clinical prescribing. Successful implementation efforts have been modeled at many academic centers. In contrast, this report provides insights into the formation of a pharmacogenomics consultation service at a safety-net hospital, which predominantly serves low-income, uninsured, and vulnerable populations. The report describes the INdiana GENomics Implementation: an Opportunity for the UnderServed (INGENIOUS) trial and addresses concerns of adjudication, credentialing, and funding
Kepler-22b: A 2.4 Earth-radius Planet in the Habitable Zone of a Sun-like Star
A search of the time-series photometry from NASA's Kepler spacecraft reveals
a transiting planet candidate orbiting the 11th magnitude G5 dwarf KIC 10593626
with a period of 290 days. The characteristics of the host star are well
constrained by high-resolution spectroscopy combined with an asteroseismic
analysis of the Kepler photometry, leading to an estimated mass and radius of
0.970 +/- 0.060 MSun and 0.979 +/- 0.020 RSun. The depth of 492 +/- 10ppm for
the three observed transits yields a radius of 2.38 +/- 0.13 REarth for the
planet. The system passes a battery of tests for false positives, including
reconnaissance spectroscopy, high-resolution imaging, and centroid motion. A
full BLENDER analysis provides further validation of the planet interpretation
by showing that contamination of the target by an eclipsing system would rarely
mimic the observed shape of the transits. The final validation of the planet is
provided by 16 radial velocities obtained with HIRES on Keck 1 over a one year
span. Although the velocities do not lead to a reliable orbit and mass
determination, they are able to constrain the mass to a 3{\sigma} upper limit
of 124 MEarth, safely in the regime of planetary masses, thus earning the
designation Kepler-22b. The radiative equilibrium temperature is 262K for a
planet in Kepler-22b's orbit. Although there is no evidence that Kepler-22b is
a rocky planet, it is the first confirmed planet with a measured radius to
orbit in the Habitable Zone of any star other than the Sun.Comment: Accepted to Ap
Phenomenology of the Lense-Thirring effect in the Solar System
Recent years have seen increasing efforts to directly measure some aspects of
the general relativistic gravitomagnetic interaction in several astronomical
scenarios in the solar system. After briefly overviewing the concept of
gravitomagnetism from a theoretical point of view, we review the performed or
proposed attempts to detect the Lense-Thirring effect affecting the orbital
motions of natural and artificial bodies in the gravitational fields of the
Sun, Earth, Mars and Jupiter. In particular, we will focus on the evaluation of
the impact of several sources of systematic uncertainties of dynamical origin
to realistically elucidate the present and future perspectives in directly
measuring such an elusive relativistic effect.Comment: LaTex, 51 pages, 14 figures, 22 tables. Invited review, to appear in
Astrophysics and Space Science (ApSS). Some uncited references in the text
now correctly quoted. One reference added. A footnote adde
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