8,677 research outputs found
Automation of surface observations program
At present, surface weather observing methods are still largely manual and labor intensive. Through the nationwide implementation of Automated Surface Observing Systems (ASOS), this situation can be improved. Two ASOS capability levels are planned. The first is a basic-level system which will automatically observe the weather parameters essential for aviation operations and will operate either with or without supplemental contributions by an observer. The second is a more fully automated, stand-alone system which will observe and report the full range of weather parameters and will operate primarily in the unattended mode. Approximately 250 systems are planned by the end of the decade. When deployed, these systems will generate the standard hourly and special long-line transmitted weather observations, as well as provide continuous weather information direct to airport users. Specific ASOS configurations will vary depending upon whether the operation is unattended, minimally attended, or fully attended. The major functions of ASOS are data collection, data processing, product distribution, and system control. The program phases of development, demonstration, production system acquisition, and operational implementation are described
NLTE 1.5D Modeling of Red Giant Stars
Spectra for 2D stars in the 1.5D approximation are created from synthetic
spectra of 1D non-local thermodynamic equilibrium (NLTE) spherical model
atmospheres produced by the PHOENIX code. The 1.5D stars have the spatially
averaged Rayleigh-Jeans flux of a K3-4 III star, while varying the temperature
difference between the two 1D component models (),
and the relative surface area covered. Synthetic observable quantities from the
1.5D stars are fitted with quantities from NLTE and local thermodynamic
equilibrium (LTE) 1D models to assess the errors in inferred
values from assuming horizontal homogeneity and LTE. Five different quantities
are fit to determine the of the 1.5D stars: UBVRI
photometric colors, absolute surface flux SEDs, relative SEDs, continuum
normalized spectra, and TiO band profiles. In all cases except the TiO band
profiles, the inferred value increases with increasing
. In all cases, the inferred value
from fitting 1D LTE quantities is higher than from fitting 1D NLTE quantities
and is approximately constant as a function of
within each case. The difference between LTE and NLTE for the TiO bands is
caused indirectly by the NLTE temperature structure of the upper atmosphere, as
the bands are computed in LTE. We conclude that the difference between
values derived from NLTE and LTE modelling is relatively
insensitive to the degree of the horizontal inhomogeneity of the star being
modeled, and largely depends on the observable quantity being fit.Comment: 46 pages, 14 figures, 7 tables, accepted for publication in ApJ on
April 5, 201
NLTE and LTE Lick indices for red giants from [M/H] 0.0 to -6.0 at SDSS and IDS spectral resolution
We investigate the dependence of the complete system of 22 Lick indices on
overall metallicity scaled from solar abundances, [M/H], from the solar value,
0.0, down to the extremely-metal-poor (XMP) value of -6.0, for late-type giant
stars (MK luminosity class III, log(g)=2.0) of MK spectral class late-K to
late-F (3750 < Teff < 6500 K) of the type that are detected as "fossils" of
early galaxy formation in the Galactic halo and in extra-galactic structures.
Our investigation is based on synthetic index values, I, derived from
atmospheric models and synthetic spectra computed with PHOENIX in LTE and
Non-LTE (NLTE), where the synthetic spectra have been convolved to the spectral
resolution, R, of both IDS and SDSS (and LAMOST) spectroscopy. We identify nine
indices, that we designate "Lick-XMP", that remain both detectable and
significantly [M/H]-dependent down to [M/H] values of at least ~-5.0, and down
to [M/H] ~ -6.0 in five cases, while also remaining well-behaved . For these
nine, we study the dependence of I on NLTE effects, and on spectral resolution.
For our LTE I values for spectra of SDSS resolution, we present the fitted
polynomial coefficients, C_n, from multi-variate linear regression for I with
terms up to third order in the independent variable pairs (Teff, [M/H]), and
(V-K, [M/H]), and compare them to the fitted C_n values of Worthey et al.
(1994) at IDS spectral resolution.Comment: Accepted for publication in the Astrophysical Journal. Tables 6 and 7
available electronically from the autho
The Human Right to Water and Unconventional Energy
Access to water, in sufficient quantities and of sufficient quality is vital for human health. The United Nations Committee on Economic, Social and Cultural Rights (in General Comment 15, drafted 2002) argued that access to water was a condition for the enjoyment of the right to an adequate standard of living, inextricably related to the right to the highest attainable standard of health, and thus a human right. On 28 July 2010 the United Nations General Assembly declared safe and clean drinking water and sanitation a human right essential to the full enjoyment of life and all other human rights. This paper charts the international legal development of the right to water and its relevance to discussions surrounding the growth of unconventional energy and its heavy reliance on water. We consider key data from the country with arguably the most mature and extensive industry, the USA, and highlight the implications for water usage and water rights. We conclude that, given the weight of testimony of local people from our research, along with data from scientific literature, non-governmental organization (NGO) and other policy reports, that the right to water for residents living near fracking sites is likely to be severely curtailed. Even so, from the data presented here, we argue that the major issue regarding water use is the shifting of the resource from society to industry and the demonstrable lack of supply-side price signal that would demand that the industry reduce or stabilize its water demand per unit of energy produced. Thus, in the US context alone, there is considerable evidence that the human right to water will be seriously undermined by the growth of the unconventional oil and gas industry, and given its spread around the globe this could soon become a global human rights issue
Mesocosm experiments quantify the effects of eutrophication on eelgrass, Zostera marina
Outdoor mesocosm experiments were used to examine the response of eelgrass communities to excess nutrient loading and reduced light that simulated coastal eutrophication. A series of replicated manipulations conducted between 1988 and 1990 demonstrated the effects of reduced available light and increased loading of nitrogen plus phosphorus on habitats dominated by eelgrass Zostera marina L. Shade and nutrients each significantly affected eelgrass growth, morphology, density, and biomass. We found no significant interactions between the effects of shade and the effects of nutrients on any plant characteristics except leaf length. The growth rate of individual eelgrass shoots was linearly related to light, increasing throughout the range of available light. Biomass and daily biomass increase, or areal growth, were also linearly related to light, but specific growth showed no response to light. Shoot density increased with the log of light. Excess nutrient loading was shown to significantly reduce eelgrass growth and bed structure through stimulation of various forms of algae that effectively competed with eelgrass for light. The absence of significant interactions between the effects of shade and nutrients on eelgrass density, growth, and biomass suggests that the negative effect of algae on eelgrass occurs primarily through the reduction of light (i.e. shading). The outcome of nutrient enrichment was a shift in plant dominance from eelgrass to three algal forms: phytoplankton, epiphytic algae, and macroalgae. We quantified the effects of eutrophication and demonstrated that increased nutrient loading results in less light for eelgrass and that eelgrass growth linearly decreases with reduced light
Comparative analysis of vaginal microbiota sampling using menstrual cups and high vaginal swabs in pregnant women living with HIV-1 infection
Background: Menstrual cups (MCs) are increasingly used to collect cervicovaginal secretions to characterise vaginal mucosal immunology, in conjunction with high vaginal swabs (HVS) for metataxonomics, particularly in HIV transmission studies. We hypothesised that both methods of collecting bacterial biomass are equivalent for 16S rRNA gene sequencing. Material and Methods: Cervicovaginal fluid (CVF) samples from 16 pregnant women with HIV-1 (PWWH) were included to represent the major vaginal bacterial community state types (CST I-V). Women underwent sampling during the second trimester by liquid amies HVS followed by a MC (Soft disc™) and samples were stored at -80°C. Bacterial cell pellets obtained from swab elution and MC (500 µL, 1 in 10 dilution) were resuspended in 120 µL PBS for DNA extraction. Bacterial 16S rRNA gene sequencing was performed using V1-V2 primers and were analysed using MOTHUR. Paired total DNA, bacterial load, amplicon read counts, diversity matrices and bacterial taxa were compared by sampling method using MicrobiomeAnalyst, SPSS and R. Results: The total DNA eluted from one aliquot of diluted CVF from an MC was similar to that of a HVS (993ng and 609ng, p=0.18); the mean bacterial loads were also comparable for both methods (MC: 8.0 log10 16S rRNA gene copies versus HVS: 7.9 log10 16S rRNA gene copies, p=0.27). The mean number of sequence reads generated from MC samples was lower than from HVS (MC: 12730; HVS:14830, p=0.05). The α-diversity metrices were similar for both techniques; MC Species Observed: 41 (range 12-96) versus HVS: 47 (range 16-96), p=0.15; MC Inverse Simpson Index: 1.98 (range 1.0-4.0) versus HVS: 0.48 (range 1.0-4.4), p=0.22). The three most abundant species observed were: Lactobacillus iners, Lactobacillus crispatus and Gardnerella vaginalis. Hierarchical clustering of relative abundance data showed that samples obtained using different techniques in an individual clustered in the same CST group. Conclusion: These data demonstrate that despite sampling slightly different areas of the lower genital tract, there was no difference in bacterial load or composition between methods. Both are suitable for characterisation of vaginal microbiota in PWWH. The MC offers advantages, including a higher volume of sample available for DNA extraction and complimentary assays
Restrictions on Access to English Language Schools in Quebec: An International Human Rights Analysis
Genetic variation and response to selection for legume-compatibility traits in orchardgrass
Perennial grass-legume mixtures are important in forage production; however, little effort has been devoted to breeding either the grass or legume component for increased compatibility in mixtures. The objectives of this research were to study the genetic variation and response to selection for legume-compatibility traits in orchardgrass. Individual plants in 97 different germplasms were evaluated for vigor traits, canopy height, growth habit, anthesis date, tiller number and leaf length and width. Polycross progenies of the parents of Iowa 79-OGP-DT were chosen for more detailed study because of their superiority in rust resistance, vigor, and winterhardiness and their variability for traits that may affect compatibility with a legume. Individual plant heritabilities were greater than 0.40 for spring canopy height, growth habit, anthesis date, and leaf width. Significant phenotype correlations indicated that winterhardiness, vigorous growth, tall spring canopy height, erect growth habit, early anthesis, and narrow leaves tend to be associated with each other. High tiller number was associated with superior spring and fall vigor, and relatively high winterhardiness. Six cycle-1 populations were developed by divergent selection in the polycross progenies for maturity, spring canopy height, and a compatibility index incorporating spring vigor, spring canopy height, growth habit, and tiller number. Significant direct and correlated responses were obtained from each selection strategy. Selection for early maturity, tall canopy height, and a high compatibility index value always decreased days to anthesis and increased spring canopy height, erectness of growth, tiller number, and dry matter yield in a space-planted test with the converse occurring from selection in the opposite direction. The three populations derived from selection for a high compatibility index value, tall spring canopy height, and early maturity consistently yielded more forage than their respective divergent populations in a space-planted test, in dense monoculture stands, and in mixtures with birdsfoot trefoil. The less aggressive populations permitted significantly more birdsfoot trefoil production in mixtures than the aggressive populations. This research indicates that it is possible to increase the compatibility of orchardgrass with birdsfoot trefoil by selection among spaced plants for decreased spring canopy height, decreased tiller number, and delayed maturity
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