1,114 research outputs found
The Economic Feasibility of Confinement Feedlots and the Analysis of Seasonal Marketing Variations for Feeder Cattle in South Dakota
South Dakota apparently produces an adequate quantity of feeders and feed grains to substantially increase slaughter cattle production. Furthermore, South Dakota prices for feed grain, roughage, and feeder cattle are equal to, or less than, the prices for these inputs in other areas where cattle feeding has flourished in recent years. It should also be determined how South Dakota farmers might increase fat cattle production. Therefore, in an attempt to explain South Dakota\u27s slow cattle feeding growth and possibly help farmers in South Dakota and neighboring areas develop the cattle feeding industry, the following problems were researched. First, this area experiences long and cold winters which can reduce cattle gains and feed efficiency. Also, the winter provides a harsh environment for a man to labor in. To alleviate the problems imposed by the state\u27s climate, it was hypothesized that total confinement feedlots may be a feasible alternative for South Dakota farmers interested in feeding cattle. The total confinement feedlots considered were cold-slatted barns and will be more completely described in later sections. A secondary issue to be considered was to determine what sizes of confinement feedlots are more economical to operate. Also, in past research in other states, the economic feasibility of operating confinement facilities instead of open lots was determined under particular assumptions. This study considered the effect of varying two assumptions which could change the feasibility of using total confinement for feeding cattle. The assumptions are: (1) wage rate for feedlot operators and (2) differences in feed efficiency or feed costs between open lots and total confinement cattle feeding barns. In trying to answer the question of why feeding could be depressed in South Dakota, another specific problem concerning feeder cattle marketing within the state was investigated. The investigation such marketing’s could provide information which could lead to another incentive to feed more cattle in South Dakota. The objectives of the study were: 1. To compare the return to management and/or ownership from various sizes of open lot and confinement feedlots, given certain prices for feeder cattle, feed grain, labor, and other inputs. 2. To compare the return to management and/or ownership from different sizes of open lot and confinement feedlots when variations in the inputs of wage rates and feed efficiency are considered. 3. To analyze the marketing intentions of feeder cattle producers within the state to evaluate supplies of feeder cattle available to cattle feedlots
A new species of Chactopsis from Brazil (Scorpiones, Chactidae)
Chactopsis amazonicus, new species (Scorpiones, Chactidae) is described based on 11 specimens (6 males and 5 females), collected in Reserva Ducke and in the Tarumã-MirÃm area (Manaus region), State of Amazonas, Brazil. C. amazonicus is the fifth species described for the genus and the second one mentioned for Brazil. Some comments concerning the taxonomic position and the geographic distribution of the species are also included
Burden for family carers at the end of life : a mixed-method study of the perspectives of family carers and GPs
Background: Since many patients spend most of the time at home at the end of life, this may affect the burden for family carers and constitute a risk factor for the patients' hospitalisation. This study aimed to explore family carers' burden in the final three months of the patient's life, from the perspective of both carers and general practitioners (GPs), and to assess whether family burden, as defined by the GP, is associated with hospitalisation.
Methods: A cross-sectional nationwide survey among GPs and family carers was performed. Participants were 194 GPs and 74 family carers of patients who died non-suddenly. Additionally, in-depth interviews were conducted with 18 family carers. For the quantitative analyses descriptive statistics, weighted Kappa and multivariate logistic regression analysis was performed. For the qualitative part thematic analysis was conducted.
Results: The proportion of family carers experiencing a fairly heavy or severe burden increased significantly from 32% (second and third months before death) to 66% (one week before death). Most carers (95%) felt an emotional burden and 29% felt a physical burden in the final week. Three-quarters of carers did not perceive their burden as a problem because caring often felt rewarding. No significant association was found between the characteristics of family caregivers or professional care and the degree of family caregiver burden. Also, there was no significant evidence that patients of family carers for whom the GP assessed a fairly heavy to severe burden, were more likely to be hospitalised.
Conclusions: The different overall assessment of family carers' burden between GPs and family carers and the increasing emotional and physical burden of family carers towards the end constitute relevant information for GPs that will help them understand and anticipate carers' personal needs
Body composition is associated with tacrolimus pharmacokinetics in kidney transplant recipients
PURPOSE: A population pharmacokinetic (popPK) model may be used to improve tacrolimus dosing and minimize under- and overexposure in kidney transplant recipients. It is unknown how body composition parameters relate to tacrolimus pharmacokinetics and which parameter correlates best with tacrolimus exposure. The aims of this study were to investigate which body composition parameter has the best association with the pharmacokinetics of tacrolimus and to describe this relationship in a popPK model. METHODS: Body composition was assessed using bio-impedance spectroscopy (BIS). Pharmacokinetic analysis was performed using nonlinear mixed effects modeling (NONMEM). Lean tissue mass, adipose tissue mass, over-hydration, and phase angle were measured with BIS and then evaluated as covariates. The final popPK model was evaluated using goodness-of-fit plots, visual predictive checks, and a bootstrap analysis. RESULTS: In 46 kidney transplant recipients, 284 tacrolimus concentrations were measured. The base model without body composition parameters included age, plasma albumin, plasma creatinine, CYP3A4 and CYP3A5 genotypes, and hematocrit as covariates. After full forward inclusion and backward elimination, only the effect of the phase angle on clearance (dOFV =  − 13.406; p < 0.01) was included in the final model. Phase angle was positively correlated with tacrolimus clearance. The inter-individual variability decreased from 41.7% in the base model to 34.2% in the final model. The model was successfully validated. CONCLUSION: The phase angle is the bio-impedance spectroscopic parameter that correlates best with tacrolimus pharmacokinetics. Incorporation of the phase angle in a popPK model can improve the prediction of an individual’s tacrolimus dose requirement after transplantation. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00228-022-03323-0
Pheromones and Barcoding Delimit Boundaries between Cryptic Species in the Primitive Moth Genus Eriocrania (Lepidoptera: Eriocraniidae)
Animal classification is primarily based on morphological characters, even though these may not be the first to diverge during speciation. In many cases, closely related taxa are actually difficult to distinguish based on morphological characters alone, especially when there is no substantial niche separation. As a consequence, the diversity of certain groups is likely to be underestimated. Lepidoptera -moths and butterflies- represent the largest group of herbivorous insects. The extensive diversification in the group is generally assumed to have its origin in the spectacular radiation of flowering plants and the resulting abundance of ecological niches. However, speciation can also occur without strong ecological divergence. For example, reproductive isolation can evolve as the result of divergence in mate preference and the associated pheromone communication system. We combined pheromone trapping and genetic analysis to elucidate the evolutionary relationships within a complex of primitive moth species (Lepidoptera: Eriocraniidae). Mitochondrial and nuclear DNA markers provided evidence that Eriocrania semipurpurella, as currently defined by morphological characters, includes three cryptic species in Northern and Western Europe. Male moths of these cryptic species, as well as of the closely related E. sangii, exhibited relative specificity in terms of their attraction to specific ratios of two major pheromone components, (2S,6Z)-nonen-2-ol and (2R,6Z)-nonen-2-ol. Our data suggest strong assortative mating in these species in the absence of apparent niche separation, indicating that Eriocrania moths may represent an example of non-ecological speciation. Finally, our study argues in favour of combining pheromone investigations and DNA barcoding as powerful tools for identifying and delimitating species boundaries
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Reconstructing palaeoclimate and hydrological fluctuations in the Fezzan Basin (southern Libya) since 130 ka: a catchment-based approach
We propose a novel method to evaluate regional palaeoclimate that can be used to alleviate the problems caused by the discontinuous nature of palaeoenvironmental data found in deserts. The technique involves processing satellite imagery and DEM’s to map past rivers, catchments and evaluate the areas and volumes of palaeolakes. This information is used to determine the new Lake Evaluation Index (LEI) that allows a qualitative estimate of the amount of sediment received by lakes and how long-lived those lakes are. Lakes with considerable longevity and large sediment stores are selected for study. Validation is performed using image interpretation of remote sensing data, UltraGPR surveys and fieldwork. These techniques are also used to identify and study spring deposits and fluvial landforms that provide valuable palaeoclimate information. The method is applied to the Fezzan Basin in southern Libya focusing on the Wadi ash Shati and Wadi el-Agial catchments. Results indicate that the palaeohydrology is accurately mapped except within dune fields. We analysed the sedimentology of the key deposits identified by this methodology, developing a chronology using optically stimulated luminescence (OSL) and radiocarbon dating. We find evidence for relatively humid conditions during MIS 5c/d and e, as well as during the early to middle Holocene. Larger lakes and more extensive river systems were present during MIS 5 than are found during the Holocene, suggestive of greater humidity. The Holocene humid period started at ~11 ka and continued until ~5 ka being interrupted by abrupt periods of aridity at ~8.2 ka and ~6 ka that coincide with North Atlantic cooling. After each of these arid events the climate was less humid than previously, suggesting that they were superimposed upon an overall drying trend. The termination of the Holocene humid period in the Sahara has received much scrutiny in recent years, and sediments of Palaeolake Shati provide a continuous record of this. We do not find evidence to support the hypothesis of either sudden or gradual aridification of the Sahara at ~5 ka, instead we find that that aridity started to develop at ~6.5 ka, whereupon the lake levels oscillated until finally drying-up by 5.3 ka. Most of the other lakes in the Fezzan also dried up at ~ 5ka. We suggest that thousands of years of aridification prior to 5 ka shrunk these lakes so that additional aridity at this time led to their final desiccation. Because lakes are prodigious dust sources this mechanism potentially explains the rapid rise in dust flux to the Atlantic at 5 ka, with this final drying being the culmination of longer term aridity, albeit overprinted with considerable climate variability
New pheromone components of the grapevine moth Lobesia botrana.
Analysis of extracts of sex pheromone glands of grapevine moth females Lobesia botrana showed three previously unidentified compounds, (E)-7-dodecenyl acetate and the (E,E)- and (Z,E)-isomers of 7,9,11-dodecatrienyl acetate. This is the first account of a triply unsaturated pheromone component in a tortricid moth. The monoenic acetate (E)-7-dodecenyl acetate and the trienic acetate (7Z,9E,11)-dodecatrienyl acetate significantly enhanced responses of males to the main pheromone compound, (7E,9Z)-7,9-dodecadienyl acetate, in the wind tunnel. The identification of sex pheromone synergists in L. botrana may be of practical importance for the development of integrated pest management systems. © 2005 Springer Science + Business Media, Inc
Mapping of human and murine genes for latent TGF-β binding protein-2 (LTBP2)
A novel gene, isolated because of structural similarities to fibrillin, was called LTBP2 when its 4.6-kb transcript was found to encode a protein sequence related to the latent TGF-β binding protein (LTBP1), which is encoded on human chromosome (Chr) 2, region p12-q22. We have assigned the human and murine LTBP2 loci to regions of conserved synteny on human Chr 11 and mouse Chr 19. By PCR analysis of somatic cell hybrid DNA and fluorescence in situ hybridization, LTBP2 was mapped to human Chr band 11q12 and Ltbp2 to mouse Chr band 19B. Differences between inbred strains were discovered by single-strand conformation analysis of PCR products from the 3′ untranslated region. Analysis of BXD and AKXL recombinant inbred strains have placed Ltbp2 between D19Rp19 and Ly10 on proximal mouse Chr 19.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47013/1/335_2004_Article_BF00350892.pd
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