1,329 research outputs found
Investigations of vegetation and soils information contained in LANDSAT Thematic Mapper and Multispectral Scanner data
An extension of the TM tasseled cap transformation to reflectance factor data is presented, and the basic concepts underlying the tasseled cap transformations are described. The ratio of TM bands 5 and 7, and TM tasseled cap wetness, are both shown to offer promise of direct detection of available soil moisture. Some effects of organic matter and other soil characteristics or constituents on TM tasseled cap spectral response are also considered
Inconsistent genetic structure among members of a multitrophic system: did bruchid parasitoids (Horismenus spp.) escape the effects of bean domestication?
Anthropogenic range expansion and cultural practices have modified the distribution, abundance and genetic diversity of domesticated organisms, thereby altering multitrophic assemblages through space and time. The putative Mesoamerican domestication centre of the common bean, Phaseolus vulgaris L., in Mexico allows investigating the effects of plant domestication on the genetic structure of members of a multitrophic system. The aim of this study was to compare the evolutionary history of Horismenus parasitoids (Hymenoptera: Eulophidae) to those of their bruchid beetle hosts (Coleoptera: Bruchidae) and their domesticated host plant (P. vulgaris), in the context of traditional agriculture in Mexico. We analyzed the population genetic structure of four Horismenus species in Mexico using mitochondrial COI haplotype data. The two most abundant parasitoid species were Horismenus depressus and Horismenus missouriensis. Horismenus missouriensis were infected by Wolbachia endosymbionts and had little to no population differentiation (F ST=0.06). We suspect the mitochondrial history of H. missouriensis to be blurred by Wolbachia, because differentiation among infected vs. non-infected individuals exists (F ST=0.11). Populations of H. depressus were found to be highly differentiated (F ST=0.34), but the genetic structuring could not be explained by tested spatial components. We then compared the genetic structure observed in this parasitoid species to previously published studies on bruchid beetles and their host plants. Despite extensive human-mediated migration and likely population homogenization of its two Acanthoscelides bruchid beetle hosts, H. depressus populations are structured like its host plant, by a recent dispersal from a diverse ancestral gene pool. Distinct evolutionary dynamics may explain inconsistent patterns among trophic levels. Parasitoids likely migrate from wild bean populations and are poorly adapted to bean storage conditions similar to their bruchid beetle hosts. Integrating several trophic levels to the study of evolutionary history has proven to be fruitful in detecting different ecological responses to human-mediated disturbances and host parasite interaction
Physical restraint use among nursing home residents: A comparison of two data collection methods
BACKGROUND: In view of the issues surrounding physical restraint use, it is important to have a method of measurement as valid and reliable as possible. We determined the sensitivity and specificity of physical restraint use a) reported by nursing staff and b) reviewed from medical and nursing records in nursing home settings, by comparing these methods with direct observation. METHODS: We sampled eight care units in skilled nursing homes, seven care units in nursing homes and one long-term care unit in a hospital, from eight facilities which included 28 nurses and 377 residents. Physical restraint use was assessed the day following three periods of direct observation by two different means: interview with one or several members of the regular nursing staff, and review of medical and nursing records. Sensitivity and specificity values were calculated according to 2-by-2 contingency tables. Differences between the methods were assessed using the phi coefficient. Other information collected included: demographic characteristics, disruptive behaviors, body alignment problems, cognitive and functional skills. RESULTS: Compared to direct observation (gold standard), reported restraint use by nursing staff yielded a sensitivity of 87.4% at a specificity of 93.7% (phi = 0.84). When data was reviewed from subjects' medical and nursing records, sensitivity was reduced to 74.8%, and specificity to 86.3% (phi = 0.54). Justifications for restraint use including risk for falls, agitation, body alignment problems and aggressiveness were associated with the use of physical restraints. CONCLUSIONS: The interview of nursing staff and the review of medical and nursing records are both valid and reliable techniques for measuring physical restraint use among nursing home residents. Higher sensitivity and specificity values were achieved when nursing staff was interviewed as compared to reviewing medical records. This study suggests that the interview of nursing staff is a more reliable method of data collection
Model studies in heterogeneous catalysis at the microscopic level: from the structure and composition of surfaces to reaction kinetics
Detecting inhomogeneous chiral condensation from the bosonic two-point function in the -dimensional Gross-Neveu model in the mean-field approximation
The phase diagram of the -dimensional Gross-Neveu model is
reanalyzed for (non-)zero chemical potential and (non-)zero temperature within
the mean-field approximation. By investigating the momentum dependence of the
bosonic two-point function, the well-known second-order phase transition from
the symmetric phase to the so-called inhomogeneous phase is
detected. In the latter phase the chiral condensate is periodically varying in
space and translational invariance is broken. This work is a proof of concept
study that confirms that it is possible to correctly localize second-order
phase transition lines between phases without condensation and phases of
spatially inhomogeneous condensation via a stability analysis of the
homogeneous phase. To complement other works relying on this technique, the
stability analysis is explained in detail and its limitations and successes are
discussed in context of the Gross-Neveu model. Additionally, we present
explicit results for the bosonic wave-function renormalization in the
mean-field approximation, which is extracted analytically from the bosonic
two-point function. We find regions -- a so-called moat regime -- where the
wave function renormalization is negative accompanying the inhomogeneous phase
as expected.Comment: 27 pages (main text 20, appendix 7), 2 tables, 13 figures (plot data
included in arXiv source file); Updated, published versio
Determination of the Properties of Composite Materials Thanks to Digital Image Correlation Measurements
AbstractDesigning composite structures for civil aircrafts necessitates a better understanding of the damage and failure mechanisms occurring in these components through experimental test campaigns and associated numerical simulations. These experimental tests have been performed at Onera using different classical measurement techniques (LVDT sensor, strain gauges…) and digital image correlation (DIC). The additional information provided by DIC allows (i) to validate the boundary conditions of the tests, (ii) to cross-check the measurements with other techniques, (iii) to improve the understanding of the physical mechanisms and (iv) to validate the predictions of the finite element simulations
Comparison of spray-dried blood meal and fish by-products in the phase II starter pig diet
A total of 311 weanling pigs (initially 10.9 lb and 17 d of age) was used to compare fish by-products, spray-dried blood meal and combinations of spray-dried blood meal and fish by-products in the phase II (d 7 to 25) diet. Pigs were allotted by weight to one of five experimental treatments with 8 to 11 pigs/pen and seven replications. Pigs were placed on a common phase I diet (d 0 to 7 postweaning) that contained 7.5%spray-dried porcine plasma, 1.75% spray-dried blood meal, and 20% dried whey. The phase I diet was formulated to contain 1.5% lysine, .9% Ca, and .8% P. Pigs were then randomly assigned to one of five dietary treatments. All phase II diets (d 7 to 25 postweaning) contained 10% dried whey and were formulated to contain 1.25% lysine and .36% methionine. The control diet contained 2.5% spray-dried blood meal (SDBM) and 10% dried whey. Select menhaden fish meal (SMFM) and spray-dried fish hydrolysate (SDFH) replaced SDBM on an equal lysine basis at 5% and 4.8%, respectively, and 2.5% SMFM + 1.25% SDBM and 2.0% SDFH + 1.25% SDBM were used in combinations to form the other four dietary treatments. Average daily gain (ADG), average daily feed intake (ADFI), and feed efficiency (F/G) were improved with the addition of SDBM in the fIrst week (d 7 to 14) of phase II. No differences were observed in ADG and ADFI for the overall phase II period. Pigs fed SDBM had poorer FIG (d 7 to 25) compared to pigs fed either SMFM or SDFH. However, SDBM was the most cost effective protein source in this experiment.; Swine Day, Manhattan, KS, November 19, 199
A combination of spray-dided porcine plasma and spray-dried blood meal optimizes starter pig performance
A total of 298 weanling pigs (initially 12.11b and 19 d of age) was used in a 25-\u3c1 growth trial to examine the influence of various combinations of spray-dried porcine plasma (SDPP) and spray-dried blood meal (SDBM) in a high nutrient density diet on starter pig performance. Pigs were allotted by weight to eight replicates of five treatments with seven to eight pigs per pen. Pigs were assigned to one of five dietary treatments with 0, 25, 50, 75, or 100% of the SDPP replaced with SDBM on an equal lysine basis. Therefore, diets contained 10, 7.5,5.0, 2.5, or 0% SDPP combined with 0, 1.63, 3.25, 4.8, or 6.5% SDBM, respectively. All phase I diets were formulated to contain 20% dried whey, 1.50% lysine, .81% isoleucine, and .37% methionine. These diets were fed from d 0 to 14 postweaning. On d 14, all pigs were switched to a common phase II diet containing 10% dried whey and 2.5% SDBM and was formulated to 1.25% lysine. Pigs were fed this diet for the remainder of the trial (d 14 to 25 postweaning). A quadratic response occurred for average daily gain and feed efficiency during phase I, with pigs fed a combination of spray-dried porcine plasma and spray-dried blood meal having superior performance compared to pigs fed diets containing only spray-dried plasma or spray-dried blood. Maximum performance was seen with the combination of 7.5% spray-dried porcine plasma and 1.63% spray-dried blood meal. Therefore, the results of this trial show that phase I diet cost can be reduced and performance improved by formulating the diet with a combination of spray-dried porcine plasma and spray-dried blood meal rather than spray-dried plasma alone.; Swine Day, Manhattan, KS, November 19, 199
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