245 research outputs found
Recommended from our members
Impacts of elevated atmospheric COā on nutrient content of important food crops.
One of the many ways that climate change may affect human health is by altering the nutrient content of food crops. However, previous attempts to study the effects of increased atmospheric CO2 on crop nutrition have been limited by small sample sizes and/or artificial growing conditions. Here we present data from a meta-analysis of the nutritional contents of the edible portions of 41 cultivars of six major crop species grown using free-air CO2 enrichment (FACE) technology to expose crops to ambient and elevated CO2 concentrations in otherwise normal field cultivation conditions. This data, collected across three continents, represents over ten times more data on the nutrient content of crops grown in FACE experiments than was previously available. We expect it to be deeply useful to future studies, such as efforts to understand the impacts of elevated atmospheric CO2 on crop macro- and micronutrient concentrations, or attempts to alleviate harmful effects of these changes for the billions of people who depend on these crops for essential nutrients
Three dimensional optic tissue culture and process
A process for artificially producing three-dimensional optic tissue has been developed. The optic cells are cultured in a bioreactor at low shear conditions. The tissue forms normal, functional tissue organization and extracellular matrix
Relationships of Polychlorinated Biphenyls and Dichlorodiphenyldichloroethylene (p,pā-DDE) with Testosterone Levels in Adolescent Males
Background: Concern persists over endocrine-disrupting effects of persistent organic pollutants (POPs) on human growth and sexual maturation. Potential effects of toxicant exposures on testosterone levels during puberty are not well characterized.
Objectives: In this study we evaluated the relationship between toxicants [polychlorinated biphenyls (PCBs), dichlorodiphenyldichloroethylene (p,pĀ“-DDE), hexachlorobenzene (HCB), and lead] and testosterone levels among 127 Akwesasne Mohawk males 10 to \u3c 17 years of age with documented toxicant exposures.
Methods: Data were collected between February 1996 and January 2000. Fasting blood specimens were collected before breakfast by trained Akwesasne Mohawk staff. Multivariable regression models were used to estimates associations between toxicants and serum testosterone, adjusted for other toxicants, Tanner stage, and potential confounders.
Results: The sum of 16 PCB congeners (Ī£16PCBs) that were detected in ā„ 50% of the population was significantly and negatively associated with serum testosterone levels, such that a 10% change in exposure was associated with a 5.6% decrease in testosterone (95% CI: ā10.8, ā0.5%). Of the 16 congeners, the more persistent ones (Ī£8PerPCBs) were related to testosterone, whereas the less persistent ones, possibly reflecting more recent exposure, were not. When PCB congeners were subgrouped, the association was significant for the sum of eight more persistent PCBs (5.7% decrease; 95% CI: ā11, ā0.4%), and stronger than the sum of six less persistent congeners (3.1% decrease; 95% CI: ā7.2, 0.9%). p,pĀ“-DDE was positively but not significantly associated with serum testosterone (5.2% increase with a 10% increase in exposure; 95% CI: ā0.5, 10.9%). Neither lead nor HCB was significantly associated with testosterone levels.
Conclusions: Exposure to PCBs, particularly the more highly persistent congeners, may negatively influence testosterone levels among adolescent males. The positive relationship between p,pĀ“-DDE and testosterone indicates that not all POPs act similarly
Effect of Alpine glaciation on thermochronometer ageāelevation profiles
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94703/1/grl22545.pd
Elevated atmospheric [CO2] can dramatically increase wheat yields in semi-arid environments and buffer against heat waves
Wheat production will be impacted by increasing concentration of atmospheric CO2 [CO2], which is expected to rise from about 400 Ī¼mol molā1 in 2015 to 550 Ī¼mol molā1 by 2050. Changes to plant physiology and crop responses from elevated [CO2] (e[CO2]) are well documented for some environments, but field-level responses in dryland Mediterranean environments with terminal drought and heat waves are scarce. The Australian Grains Free Air CO2 Enrichment facility was established to compare wheat (Triticum aestivum) growth and yield under ambient (~370 Ī¼molā1 in 2007) and e[CO2] (550 Ī¼molā1) in semi-arid environments. Experiments were undertaken at two dryland sites (Horsham and Walpeup) across three years with two cultivars, two sowing times and two irrigation treatments. Mean yield stimulation due to e[CO2] was 24% at Horsham and 53% at Walpeup, with some treatment responses greater than 70%, depending on environment. Under supplemental irrigation, e[CO2] stimulated yields at Horsham by 37% compared to 13% under rainfed conditions, showing that water limited growth and yield response to e[CO2]. Heat wave effects were ameliorated under e[CO2] as shown by reductions of 31% and 54% in screenings and 10% and 12% larger kernels (Horsham and Walpeup). Greatest yield stimulations occurred in the e[CO2] late sowing and heat stressed treatments, when supplied with more water. There were no clear differences in cultivar response due to e[CO2]. Multiple regression showed that yield response to e[CO2] depended on temperatures and water availability before and after anthesis. Thus, timing of temperature and water and the crop's ability to translocate carbohydrates to the grain postanthesis were all important in determining the e[CO2] response. The large responses to e[CO2] under dryland conditions have not been previously reported and underscore the need for field level research to provide mechanistic understanding for adapting crops to a changing climate
Elevated atmospheric [CO<sub>2</sub>] can dramatically increase wheat yields in semi-arid environments and buffer against heat waves
Tausz, M ORCiD: 0000-0001-8205-8561Wheat production will be impacted by increasing concentration of atmospheric CO2 [CO2], which is expected to rise from about 400 Ī¼mol mol-1 in 2015 to 550 Ī¼mol mol-1 by 2050. Changes to plant physiology and crop responses from elevated [CO2] (e[CO2]) are well documented for some environments, but field-level responses in dryland Mediterranean environments with terminal drought and heat waves are scarce. The Australian Grains Free Air CO2 Enrichment facility was established to compare wheat (Triticum aestivum) growth and yield under ambient (~370 Ī¼mol-1 in 2007) and e[CO2] (550 Ī¼mol-1) in semi-arid environments. Experiments were undertaken at two dryland sites (Horsham and Walpeup) across three years with two cultivars, two sowing times and two irrigation treatments. Mean yield stimulation due to e[CO2] was 24% at Horsham and 53% at Walpeup, with some treatment responses greater than 70%, depending on environment. Under supplemental irrigation, e[CO2] stimulated yields at Horsham by 37% compared to 13% under rainfed conditions, showing that water limited growth and yield response to e[CO2]. Heat wave effects were ameliorated under e[CO2] as shown by reductions of 31% and 54% in screenings and 10% and 12% larger kernels (Horsham and Walpeup). Greatest yield stimulations occurred in the e[CO2] late sowing and heat stressed treatments, when supplied with more water. There were no clear differences in cultivar response due to e[CO2]. Multiple regression showed that yield response to e[CO2] depended on temperatures and water availability before and after anthesis. Thus, timing of temperature and water and the crop's ability to translocate carbohydrates to the grain postanthesis were all important in determining the e[CO2] response. The large responses to e[CO2] under dryland conditions have not been previously reported and underscore the need for field level research to provide mechanistic understanding for adapting crops to a changing climate. Ā© 2016 John Wiley & Sons Ltd
Production of and mesons in UU collisions at GeV
The PHENIX experiment at the Relativistic Heavy Ion Collider measured
and mesons at midrapidity in UU collisions at
GeV in a wide transverse momentum range. Measurements were performed in the
decay modes. A strong suppression of
and meson production at high transverse momentum was observed in
central UU collisions relative to binary scaled results. Yields of
and mesons measured in UU collisions show similar suppression
pattern to the ones measured in AuAu collisions at
GeV for similar numbers of participant nucleons. The / ratios do
not show dependence on centrality or transverse momentum, and are consistent
with previously measured values in hadron-hadron, hadron-nucleus,
nucleus-nucleus, and collisions.Comment: 403 authors from 72 institutions, 13 pages, 6 figures, 7 tables, 2012
data. v2 is version accepted by Physical Review C. Plain text data tables for
the points plotted in figures for this and previous PHENIX publications are
(or will be) publicly available at http://www.phenix.bnl.gov/papers.htm
An Exo-Kuiper Belt with an Extended Halo around HD 191089 in Scattered Light
We have obtained Hubble Space Telescope STIS and NICMOS and Gemini/GPI scattered-light images of the HD 191089 debris disk. We identify two spatial components: a ring resembling the Kuiper Belt in radial extent (FWHM ā¼ 25 au, centered at ā¼46 au) and a halo extending to ā¼640 au. We find that the halo is significantly bluer than the ring, consistent with the scenario that the ring serves as the birth ring for the smaller dust in the halo. We measure the scattering phase functions in the 30Ā°-150Ā° scattering-angle range and find that the halo dust is more forward- and backward-scattering than the ring dust. We measure a surface density power-law index of -0.68 Ā± 0.04 for the halo, which indicates the slowdown of the radial outward motion of the dust. Using radiative transfer modeling, we attempt to simultaneously reproduce the (visible) total and (near-infrared) polarized intensity images of the birth ring. Our modeling leads to mutually inconsistent results, indicating that more complex models, such as the inclusion of more realistic aggregate particles, are needed
- ā¦