621 research outputs found
The Ecosystem of Bioethics: Building Bridges to Public Health
Understanding bioethical inquiry as ecosystem aligns that thinking about health conceptually close to public health ethics. Despite having roots in decades-long, culturally-diverse, and disciplinarily-broad concerns about the relationships of human beings to environment as manifest in the work of Fritz Jahr and Van Rensselaer Potter, medical “mainstream” bioethics has maintained a relatively narrow focus on individual health. The practical instantiations of bioethics are inconsistent both with the term’s own historical international contexts and the ecosystemic nature of health, a concept of systems that includes both cultural and biological interactions. Following a growing number of international calls for such change in bioethics, this paper argues that a reinvigoration of bioethics demands transdisciplinary intersections of ecology, value, and health – as a bridge connecting across to the identified projects of public health ethics
Postoperative Complications Associated with External Skeletal Fixators in Dogs
OBJECTIVES: To quantify and evaluate risks of complications attributable to external skeletal fixator (ESF) usage in dogs. METHODS: A retrospective review of medical records following ESF placement. RESULTS: Case records of 97 dogs were reviewed; fixator-associated complications occurred in 79/97 dogs. Region of ESF placement was significantly associated with complication development (p = 0.005), not complication type (p = 0.086). Complications developed most frequently in the tarsus (9/10), manus (8/9) and humerus (8/9). Superficial pin-tract infection and implant failure occurred in 38/97 and 17/97 dogs, respectively. Superficial pin-tract infection occurred frequently in the femur, humerus, radius and ulna and the pes, with implant failure frequent in the tarsus and deep pin-tract infection in the manus and tibia. Transarticular frames were significantly more likely to develop a complication (p = 0.028). Age was significantly associated with complication development (p = 0.029). No associations between breed, sex, weight, fracture type (open or closed), ESF classification and the incidence or type of complications were identified. No associations between, breed, age, sex, weight, fracture type (open or closed), ESF classification and the time to complication development were identified. CLINICAL SIGNIFICANCE: Fixator-associated complications are common in dogs, with the majority of complications related to implant infection. Region and placement of transarticular frames should be carefully considered when selecting stabilization method
Identification of mutations in the bovine KIT gene, a candidate for the Spotted locus in cattle
AbstractIn mammals, abnormal migration of melanoblasts from the neural crest during embryonic development may be the reason of the pielbaldism phenotype that is a mixture of pigmented and unpigmented areas in the coat. Several cattle breeds, like for example Holstein, show the piebald spotted coat colour phenotype, that, according to crossbreeding studies, is due to a recessive allele (s), member of the allele series of the Spotted (S) locus. Dominant alleles at this locus act as suppressors of the spotted pattern and produce uniformly pigmented animals while others determine the colour-sided pattern known, for example, in the Hereford breed. The bovine v-kit Hardy-Zuckerman 4 feline sarcoma viral oncogene (KIT) gene was localized in the region of chromosome 6 where the Spotted locus was mapped. KIT plays a major role during the embryonic development in directing the migration of the melanoblasts from the neural crest. Mutations in this gene cause different coat colour patterns in mouse and human. In pigs..
The Ecosystem of Bioethics: Building Bridges to Public Health
Understanding bioethical inquiry as ecosystem aligns that thinking about health conceptually close to public health ethics. Despite having roots in decades-long, culturally-diverse, and disciplinarily-broad concerns about the relationships of human beings to environment as manifest in the work of Fritz Jahr and Van Rensselaer Potter, medical “mainstream” bioethics has maintained a relatively narrow focus on individual health. The practical instantiations of bioethics are inconsistent both with the term’s own historical international contexts and the ecosystemic nature of health, a concept of systems that includes both cultural and biological interactions. Following a growing number of international calls for such change in bioethics, this paper argues that a reinvigoration of bioethics demands transdisciplinary intersections of ecology, value, and health – as a bridge connecting across to the identified projects of public health ethics
Joint analysis of two breed cross populations in pigs to improve detection and characterization of quantitative trait loci
The purpose of this study was to develop and implement least squares interval-mapping models for joint analysis of breed cross QTL mapping populations and to evaluate the effect of joint analysis on QTL detected for economic traits in data from two breed crosses in pigs. Data on 26 growth, carcass composition, and meat quality traits from F2 crosses between commercially relevant pig breeds were used: a Berkshire × Yorkshire cross at Iowa State University (ISU) and a Berkshire × Duroc cross at the University of Illinois (UOI). All animals were genotyped for a total of 39 (ISU) and 32 (UOI) markers on chromosomes 2, 6, 13, and 18. Marker linkage maps derived from the individual and joint data were similar with regard to order and relative position, but some differences in absolute distances existed. Maps from the joint data were used in all analyses. The individual and joint data sets were analyzed using several least squares interval-mapping models: line-cross (LC) models with Mendelian and parent-of-origin effects; halfsib models (HS); and combined models (CB) that included LC and HS effects. Lack-of-fit tests between the models were used to characterize QTL for mode of expression and to identify segregation of QTL within parental breeds. A total of 26 (8), 47 (18), and 53 (16) QTL were detected at the 5% chromosome (genome)-wise level in the ISU, UOI, and joint data for the 26 analyzed traits. Of the 53 QTL detected in the joint data, only six were detected in both populations and for many, allele effects differed between the two crosses. Despite the lack of overlap between the two populations, joint analysis resulted in an increase in significance for many QTL, including detection of ten QTL that did not reach significance in either population. Confidence intervals for position also were smaller for several QTL. In contrast, 24 QTL, most of which were detected at chromosome-wise levels in the ISU or UOI population, were not detected in the joint data. Presence of paternally expressed QTL near the IGF2 region of SSC2 was confirmed, with major effects on backfat and loin muscle area, particularly in the UOI population, as well as one or more QTL for carcass composition in the distal arm of Chromosome 6. Results of this study suggest that joint analysis using a range of QTL models increases the power of QTL mapping and QTL characterization, which helps to identify genes for subsequent marker-assisted selection
Understanding Relationships Among Abundance, Extirpation, and Climate at Ecoregional Scales
Recent research on mountain-dwelling species has illustrated changes in species\u27 distributional patterns in response to climate change. Abundance of a species will likely provide an earlier warning indicator of change than will occupancy, yet relationships between abundance and climatic factors have received less attention. We tested whether predictors of counts of American pikas (Ochotona princeps) during surveys from the Great Basin region in 1994-1999 and 2003-2008 differed between the two periods. Additionally, we tested whether various modeled aspects of ecohydrology better predicted relative density than did average annual precipitation, and whether risk of site-wide extirpation predicted subsequent population counts of pikas. We observed several patterns of change in pika abundance at range edges that likely constitute early warnings of distributional shifts. Predictors of pika abundance differed strongly between the survey periods, as did pika extirpation patterns previously reported from this region. Additionally, maximum snowpack and growing-season precipitation resulted in better-supported models than those using average annual precipitation, and constituted two of the top three predictors of pika density in the 2000s surveys (affecting pikas perhaps via vegetation). Unexpectedly, we found that extirpation risk positively predicted subsequent population size. Our results emphasize the need to clarify mechanisms underlying biotic responses to recent climate change at organism-relevant scales, to inform management and conservation strategies for species of concern
Monitoring temporal change in riparian vegetation of Great Basin National Park
Disturbance in riparian areas of semiarid ecosystems involves complex interactions of pulsed hydrologic flows, herbivory, fire, climatic effects, and anthropogenic influences. We resampled riparian vegetation within ten 10-m × 100-m plots that were initially sampled in 1992 in 4 watersheds of the Snake Range, east central Nevada. Our finding of significantly lower coverage of grasses, forbs, and shrubs within plots in 2001 compared with 1992 was not consistent with the management decision to remove livestock grazing from the watersheds in 1999. Change over time in cover of life-forms or bare ground was not predicted by scat counts within plots in 2001. Cover results were also not well explained by variability between the 2 sampling periods in either density of native herbivores or annual precipitation. In contrast, Engelmann spruce (Picea engelmannii) exhibited reduced abundance at all but the highest-elevation plot in which it occurred in 1992, and the magnitude of change in abundance was strongly predicted by plot elevation. Abundance of white fir (Abies concolor) individuals increased while aspen (Populus tremuloides) individuals decreased at 4 of 5 sites where they were sympatric, and changes in abundance in the 2 species were negatively correlated across those sites. Utility of monitoring data to detect change over time and contribute to adaptive management will vary with sample size, observer bias, use of repeatable or published methods, and precision of measurements, among other factors
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Effect of linseed oil and fish oil alone or as an equal mixture on ruminal fatty acid metabolism in growing steers fed maize silage-based diets
Based on the potential benefits to human health there is interest in increasing 18:3n-3, 20:5n-3, 22:6n-6, and cis-9,trans-11 conjugated linoleic acid (CLA) in ruminant foods. Four Aberdeen Angus steers (406 ± 8.2 kg BW) fitted with rumen and duodenal cannulae were used in a 4 x 4 Latin square experiment with 21 d periods to examine the potential of fish oil (FO) and linseed oil (LO) in the diet to increase ruminal outflow of trans-11 18:1 and total n-3 polyunsaturated fatty acids (PUFA) in growing cattle. Treatments consisted of a control diet (60:40; forage:concentrate ratio, on a DM basis, respectively) based on maize silage, or the same basal ration containing 30 g/kg DM of FO, LO or a mixture (1:1, w/w) of FO and LO (LFO). Diets were offered as total mixed rations and fed at a rate of 85 g DM/kg BW0.75/d. Oils had no effect (P = 0.52) on DM intake. Linseed oil had no effect (P > 0.05) on ruminal pH or VFA concentrations, while FO shifted rumen fermentation towards propionate at the expense of acetate. Compared with the control, LO increased (P < 0.05) 18:0, cis 18:1 (Δ9, 12-15), trans 18:1 (Δ4-9, 11-16), trans 18:2, geometric isomers of ∆9,11, ∆11,13, and ∆13,15 CLA, trans-8,cis-10 CLA, trans-10,trans-12 CLA, trans-12,trans-14 CLA, and 18:3n-3 flow at the duodenum. Inclusion of FO in the diet resulted in higher (P < 0.05) flows of cis-9 16:1, trans 16:1 (Δ6-13), cis 18:1 (Δ9, 11, and 13), trans 18:1 (Δ6-15), trans 18:2, 20:5n-3, 22:5n-3, and 22:6n-3, and lowered (P < 0.001) 18:0 at the duodenum relative to the control. For most fatty acids at the duodenum responses to LFO were intermediate of FO and LO. However, LFO resulted in higher (P = 0.04) flows of total trans 18:1 than LO and increased (P < 0.01) trans-6 16:1 and trans-12 18:1 at the duodenum compared with FO or LO. Biohydrogenation of cis-9 18:1 and 18:2n-6 in the rumen was independent of treatment, but both FO and LO increased (P < 0.001) the extent of 18:3n-3 biohydrogenation compared with the control. Ruminal 18:3n-3 biohydrogenation was higher (P < 0.001) for LO and LFO than FO, while biohydrogenation of 20:5n-3 and 22:6n-3 in the rumen was marginally lower (P = 0.05) for LFO than FO. In conclusion, LO and FO at 30 g/kg DM altered the biohydrogenation of unsaturated fatty acids in the rumen causing an increase in the flow of specific intermediates at the duodenum, but the potential of these oils fed alone or as a mixture to increase n-3 PUFA at the duodenum in cattle appears limited
Prediction of milk protein concentration from elements of the metabolizable protein system
Elements of the metabolizable protein system in the United Kingdom were examined for their suitability as potential predictors of milk protein concentration. Models were based on data from 163 cows offered five forage mixtures for ad libitum intake plus concentrates at 3, 6, or 9 kg/d of dry matter. The models were then tested on a separate data set of 100 cows offered seven forage mixtures for ad libitum intake plus concentrates at 6 kg/d of dry matter. To minimize problems with collinearity, variables were arranged hierarchically; successive elements were components of variables at higher element levels. Variables from different element levels were not used in the same models. Models were constructed using ridge regression to minimize problems with collinearity.
The fit and precision of prediction were generally poor because these models did not take into account animal variables. Models using undegradable dietary protein performed slightly better than did those using digestible undegraded protein. The use of slowly degradable protein and quickly degradable protein rather than rumen-degradable protein generally resulted in improvements in prediction. Models using neutral detergent fiber and quickly fermented carbohydrate were better than those using total carbohydrate. We concluded that there was little to be gained from using the elements of the metabolizable protein system considered here for the prediction of milk protein concentration
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