4,334 research outputs found
The 1998 floods in Bangladesh: disaster impacts, household coping strategies, and responses
This report combines a careful analysis of government policy and private foodgrain markets with a detailed survey of 757 households in rural Bangladesh in November and December 1998, about two months after the floodwaters receded. The report describes short- and medium-term government policy measures taken to encourage private trade, including an earlier trade liberalization that permitted private-sector imports of rice from India that stabilized private markets and largely offset the decline in production. The impact of the floods on household assets, employment, consumption, and nutritional outcomes is analyzed using the micro-level survey data. The study finds that flood-exposed households were, in general, able to avoid severe declines in food consumption and nutritional status through a combination of private-sector borrowing... and targeted government and NGO transfers.Food relief Bangladesh., Food supply Bangladesh., Disasters Asia., Households Bangladesh.,
Feeding Preferences of Omnivorous Gizzard Shad as Influenced by Fish Size and Zooplankton Density
In Ohio reservoirs, larval gizzard shad Dorosoma cepedianum less than 30 mm total
length consume only zooplankton but frequently switch to detritus as they grow longer than 30 mm. However, in laboratory studies without detritus, gizzard shad longer than 30 mm consume crustacean zooplankton. To explore the composition of diets of omnivorous 30-100-mm gizzard
shad, we completed 1-h laboratory feeding trials with different amounts of zooplankton and detritus and quantified the diets of gizzard shad in reservoirs. In both laboratory and field, gizzard shad
ate primarily detritus but also ate zooplankton, consuming more as more became available, which demonstrates that this species is a facultative detritivore. In the field, zooplankton consumption
declined as gizzard shad body size increased. We believe gizzard shad maximize growth by supplementing their low-protein detritus diet with more zooplankton as more becomes available. With this strategy, omnivorous gizzard shad may compromise the potential for food web manipulations
based on the trophic cascade hypothesis in Ohio reservoirs.This work was supported by Federal Aid in Sport
Fish Restoration project F-57-R, administered
jointly by the U.S. Fish and Wildlife Service and the Ohio Division of Wildlife, to R.A.S
Feeding Preferences of Omnivorous Gizzard Shad as Influenced by Fish Size and Zooplankton Density
Iodothyronine Interactions with the System L1 Amino Acid Exchanger in 3T3-L1 Adipocytes
Thyroid hormones enter isolated white adipocytes largely by a System L1-type amino acid transporter en route to exerting genomic actions. Differentiated 3T3-L1 mouse adipocytes in culture express mRNA for LAT1 (the catalytic subunit of high-affinity System L1). L-[125I]-T3 uptake into 3T3-L1 adipocytes included a substantial saturable component inhibited by leucine. L-[3H]phenylalanine uptake into 3T3-L1 cells was saturable (Km of 31 μM), competitively inhibited by T3 (Ki of 1.2 μM) and blocked by leucine, BCH, and rT3 as expected for substrate interactions of System L1. Efflux of preloaded L-[3H]phenylalanine from 3T3-L1 adipocytes was trans stimulated by external leucine, demonstrating the obligatory exchange mechanism of System L1 transport. T3 (10 μM) did not significantly trans stimulate L-[3H]phenylalanine efflux, but did competitively inhibit the trans stimulatory effect of 10 μM leucine. The results highlight strong competitive interactions between iodothyronines (T3, rT3) and amino acids for transport by System L1 in adipocytes, which may impact cellular iodothyronine exchanges during altered states of protein nutrition
Can pre-supernova winds from massive stars enrich the interstellar medium with nitrogen at high redshift?
Understanding the nucleosynthetic origin of nitrogen and the evolution of the
N/O ratio in the interstellar medium is crucial for a comprehensive picture of
galaxy chemical evolution at high-redshift because most observational
metallicity (O/H) estimates are implicitly dependent on the N/O ratio. The
observed N/O at high-redshift shows an overall constancy with O/H, albeit with
a large scatter. We show that these heretofore unexplained features can be
explained by the pre-supernova wind yields from rotating massive stars
(M, ). Our models
naturally produce the observed N/O plateau, as well as the scatter at low O/H.
We find the scatter to arise from varying star formation efficiency. However,
the models that have supernovae dominated yields produce a poor fit to the
observed N/O at low O/H. This peculiar abundance pattern at low O/H suggests
that dwarf galaxies are most likely to be devoid of SNe yields and are
primarily enriched by pre-supernova wind abundances.Comment: 6 pages, 1 figure, published in Proceedings of the International
Astronomical Union No. 366, 2022 titled "The Origin of Outflows in Evolved
Stars
Relationship between food waste, diet quality, and environmental sustainability
Improving diet quality while simultaneously reducing environmental impact is a critical focus globally. Metrics linking diet quality and sustainability have typically focused on a limited suite of indicators, and have not included food waste. To address this important research gap, we examine the relationship between food waste, diet quality, nutrient waste, and multiple measures of sustainability: use of cropland, irrigation water, pesticides, and fertilizers. Data on food intake, food waste, and application rates of agricultural amendments were collected from diverse US government sources. Diet quality was assessed using the Healthy Eating Index-2015. A biophysical simulation model was used to estimate the amount of cropland associated with wasted food. This analysis finds that US consumers wasted 422g of food per person daily, with 30 million acres of cropland used to produce this food every year. This accounts for 30% of daily calories available for consumption, one-quarter of daily food (by weight) available for consumption, and 7% of annual cropland acreage. Higher quality diets were associated with greater amounts of food waste and greater amounts of wasted irrigation water and pesticides, but less cropland waste. This is largely due to fruits and vegetables, which are health-promoting and require small amounts of cropland, but require substantial amounts of agricultural inputs. These results suggest that simultaneous efforts to improve diet quality and reduce food waste are necessary. Increasing consumers’ knowledge about how to prepare and store fruits and vegetables will be one of the practical solutions to reducing food waste
Bartlett correction factors in logistic regression models
Bartlett correction factors for likelihood ratio tests of parameters in conditional and unconditional logistic regression models are calculated. The resulting tests are compared to the Wald, likelihood ratio, and score tests, and a test proposed by Moolgavkar and Venzon in Modern Statistical Methods in Chronic Disease Epidemiology. (Wiley, New York, 1986).Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/31011/1/0000686.pd
Modelling the Pan-Spectral Energy Distribution of Starburst Galaxies: III. Emission Line Diagnostics of Ensembles of Evolving HII Regions
We build, as far as theory will permit, self consistent model HII regions
around central clusters of aging stars. These produce strong emission line
diagnostics applicable to either individual HII regions in galaxies, or to the
integrated emission line spectra of disk or starburst galaxies. The models
assume that the expansion and internal pressure of individual HII regions is
driven by the net input of mechanical energy from the central cluster, be it
through winds or supernova events. This eliminates the ionization parameter as
a free variable, replacing it with a parameter which depends on the ratio of
the cluster mass to the pressure in the surrounding interstellar medium. These
models explain why HII regions with low abundances have high excitation, and
demonstrate that at least part of the warm ionized medium is the result of
overlapping faint, old, large, and low pressure HII regions. We present line
ratios (at both optical and IR wavelengths) which provide reliable abundance
diagnostics for both single HII regions or for integrated galaxy spectra, and
we find a number that can be used to estimate the mean age of the cluster stars
exciting individual HII regions.Comment: 22 pages. 18 figures. Accepted for publication in Astrophysical
journal Supplements. Electronic tabular material is available on request to
[email protected]
- …