377 research outputs found
Deepwater Horizon Oil Spill: An Ethics Case Study in Environmental Engineering
The April 20, 2010 Deepwater Horizon oil rig explosion was an engineering and environmental tragedy that led to the loss of 11 human lives and has had far-reaching environmental and economic impacts, the full extent of which is difficult if not impossible to calculate. In 2015 the explosion continues to impact those 11 individual’s families; it continues to have a far-reaching emotional impact on the 115 men and women on board at the time of the catastrophe; scientists are still evaluating the environmental impacts of both the oil dispersion throughout the gulf and the oil dispersant used to curtail the spill at surface depths. Simultaneously, gulf business owners, particularly those who rely on gulf waters for their livelihoods, continue to struggle. This novel and far-reaching real-world disaster is particularly salient for use within engineering curricula due to its inherently complex interplay of ethical issues and the broad scope of stakeholders impacted by the initial disaster and its aftermath.
We have developed and refined this real-world case study with students participating in a graduate level course at Purdue University over three separate years and five course offerings. We designed this case study within a unique pedagogical framework that leads students to reflectively adopt varying stakeholders’ perspectives in order to reason through the case within a team setting. As a final goal, students must decide the appropriateness of continuing deepwater drilling throughout the Gulf of Mexico in light of the human, economic, environmental, and social implications of future potential blowouts. As part of the broader ethics course in which this case is embedded, we selected this case as it provides a uniquely broader scope of stakeholders and a more specific focus on the principles of nonmaleficence and justice when compared to the other cases presented to students. Specifically, this case asks students to consider a broad range of stakeholders. Whereas many engineering ethics case studies focus on human stakeholders and corporations, here the focus also includes marine and aquatic life, challenging a narrowly anthropocentric focus by placing environmental issues as a focal point. In this sense, our focus pushes beyond other case studies in ethics by addressing both macro-ethical issues, where students are encouraged to adopt a broadened societal viewpoint to deduce the most ethical courses of action, and micro-ethical issues, where the focus is towards the professional obligations of an individual engineer, through a scaffolded staged pedagogy.
In this paper we present the case structure and pedagogy to argue for the relevance of this unique, novel, and effective case for increasing engineering students’ ethical reasoning abilities, particularly broadening their awareness of the scope of stakeholders impacted by engineering decisions and their ability to empathize with those stakeholders
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..
An evaluation of risk-based monitoring in pragmatic trials in UK Clinical Trials Units
Background
Good Clinical Practice guidelines issued in 2016 encourage risk-based approaches to monitoring clinical trials. This study compared current risk assessment and monitoring approaches in UK Clinical Trials Units (CTUs) with the published guidance and makes recommendations for risk-based monitoring in pragmatic trials.
Methods
An online survey of UK Clinical Research Collaboration registered CTUs was administered via email invitation. Forty-nine units were invited, and 23 responded. Respondents were also invited to share copies of risk assessment templates.
Results
Most CTUs reported using remote combined with on-site monitoring. All reported undertaking a risk assessment for Clinical Trials of Investigational Medicinal Products (CTIMPs) and 21 units did so for non-CTIMPs. Most CTIMP risk assessments used MHRA (Medicines and Healthcare products Regulatory Agency) classifications, although some also employed staff judgement. Almost all units based their monitoring on perceived risk level; this number was higher for CTIMPs (n = 22) than for non-CTIMPs (n = 19). In most cases, monitoring plans were produced. More CTUs revisited risk assessments during trials in CTIMPs (n = 21) than in non-CTIMPs (n = 18). Small numbers of units reviewed the monitoring approach always (n = 4) or sometimes (n = 9) and few used the reflection to guide future monitoring.
Conclusions
A high proportion of UK CTUs are using risk-based monitoring in the UK, as recommended by guidelines, for both CTIMPs and non-CTIMPs. This has the potential to make trials more efficient and reduce costs. However, there appears to be a lack of reflection on the value of these revised approaches. There may be a benefit in CTUs collaborating nationally to improve processes for reflection and making changes during the life course of a trial
Fine-mapping of a QTL influencing pork tenderness on porcine chromosome 2
<p>Abstract</p> <p>Background</p> <p>In a previous study, a quantitative trait locus (QTL) exhibiting large effects on both Instron shear force and taste panel tenderness was detected within the Illinois Meat Quality Pedigree (IMQP). This QTL mapped to the q arm of porcine chromosome 2 (SSC2q). Comparative analysis of SSC2q indicates that it is orthologous to a segment of human chromosome 5 (HSA5) containing a strong positional candidate gene, calpastatin (<it>CAST</it>). <it>CAST </it>polymorphisms have recently been shown to be associated with meat quality characteristics; however, the possible involvement of other genes and/or molecular variation in this region cannot be excluded, thus requiring fine-mapping of the QTL.</p> <p>Results</p> <p>Recent advances in porcine genome resources, including high-resolution radiation hybrid and bacterial artificial chromosome (BAC) physical maps, were utilized for development of novel informative markers. Marker density in the ~30-Mb region surrounding the most likely QTL position was increased by addition of eighteen new microsatellite markers, including nine publicly-available and nine novel markers. Two newly-developed markers were derived from a porcine BAC clone containing the <it>CAST </it>gene. Refinement of the QTL position was achieved through linkage and haplotype analyses. Within-family linkage analyses revealed at least two families segregating for a highly-significant QTL in strong positional agreement with <it>CAST </it>markers. A combined analysis of these two families yielded QTL intervals of 36 cM and 7 cM for Instron shear force and taste panel tenderness, respectively, while haplotype analyses suggested further refinement to a 1.8 cM interval containing <it>CAST </it>markers. The presence of additional tenderness QTL on SSC2q was also suggested.</p> <p>Conclusion</p> <p>These results reinforce <it>CAST </it>as a strong positional candidate. Further analysis of <it>CAST </it>molecular variation within the IMQP F<sub>1 </sub>boars should enhance understanding of the molecular basis of pork tenderness, and thus allow for genetic improvement of pork products. Furthermore, additional resources have been generated for the targeted investigation of other putative QTL on SSC2q, which may lead to further advancements in pork quality.</p
Landscape-Scale Conservation And Management Of Montane Wildlife: Contemporary Climate May Be Changing The Rules
Both paleontological and contemporary results have suggested that montane ecosystems to be systems of relatively rapid faunal change compared to many valley-bottom counterparts. In addition to experiencing greater magnitudes of contemporary change in climatic parameters than species in other ecosystems, mountain-dwelling wildlife must also accommodate often greater intra-annual swings in temperature and wind speeds, poorly developed soils, and generally harsher conditions. Research on a mountain-dwelling mammal species across 15 yrs of contemporary data and historical records from 1898-1956 suggest that pace of local extinctions and rate of upslope retraction have been markedly more rapid and governed by markedly different dynamics in the last decade than during the 20th century. This may mean that understanding past dynamics of species losses may not always help predict patterns of future loss. Given the importance of clinal variability and ecotypic variation, phenotypic plasticity, behavioral plasticity, and variation in climatic conditions, for widely-distributed species’ geographic ranges to be determined by different factors in different portions of their range is not uncommon. Consequently, greatest progress in understanding distributionalchange phenomena will occur with coordinated, landscape-scale research and monitoring. Landscape Conservation Cooperatives and Climate Science Centers are newly emerging efforts that may contribute greatly to such broad-scale investigations, e.g., climate-wildlife relationships. Based on our empirical findings and our review of related literature, we propose tenets that may serve as foundational starting points for mechanism-based research at broad scales to inform management and conservation of diverse montane wildlife and the ecosystem components with which they interact
Niche shifts and energetic condition of songbirds in response to phenology of food-resource availability in a high-elevation sagebrush ecosystem
Seasonal fluctuations in food availability can affect diets of consumers, which in turn may influence the physiological state of individuals and shape intra- and inter-specific patterns of resource use. High-elevation ecosystems often exhibit a pronounced seasonal “pulse” in productivity, although few studies document how resource use and energetic condition by avian consumers change in relation to food-resource availability in these ecosystems. We tested the hypothesis that seasonal increases (pulses) in food resources in high-elevation sagebrush ecosystems result in 2 changes after the pulse, relative to the before-pulse period: (1) reduced diet breadth of, and overlap between, 2 sympatric sparrow species; and (2) enhanced energetic condition in both species. We tracked breeding-season diets using stable isotopes and energetic condition using plasma metabolites of Brewer\u27s Sparrows (Spizella breweri), Vesper Sparrows (Pooecetes gramineus), and their food resources during 2011, and of only Brewer\u27s Sparrows and their food resources during 2013. We quantify diet breadth and overlap between both species, along with coincident physiological consequences of temporal changes in resource use. After invertebrate biomass increased following periods of rainfall in 2011, dietary breadth decreased by 35% in Brewer\u27s Sparrows and by 48% in Vesper Sparrows, while dietary overlap decreased by 88%. Energetic condition of both species increased when dietary overlap was lower and diet breadth decreased, after the rapid rise of food-resource availability. However, energetic condition of Brewer\u27s Sparrows remained constant in 2013, a year with low precipitation and lack of a strong pulse in food resources, even though the species\u27 dietary breadth again decreased that year. Our results indicate that diet breadth and overlap in these sparrow species inhabiting sagebrush ecosystems generally varied as predicted in relation to intra- and interannual changes in food resources, and this difference in diet was associated with improved energetic condition of sparrows at least in one year
Characterization of the Prion Protein (PRP) Gene in Ten Breeds of Sheep
Transmissible Spongiform Encephalopathies (TSE\u27s) are neurodegenerative disorders characterized by a long generation time, spongy degeneration in the cerebral gray matter, neuronal loss and proliferation and hypertrophy of glial cells. An abnormal form of the prion protein (PrP) plays a major part in TSE pathogenesis and has been hypothesized to be the only component of the infectious agent. Some animals exposed to scrapie, the TSE affecting sheep and goats, seem to be resistant to development of the disease. Alleles encoding amino acid substitutions at codons 136 (A/V) and 171 (Q/R/H) have been associated with scrapie resistance. Other amino acid substitutions at codons 112 (M/T), 137 (M/T), 141 (L/F), 154 (R/H), and 211 (R/Q) have been reported but not associated with scrapie resistance. It may be possible to reduce the incidence of ovine scrapie by increasing the frequency of resistant genotypes (AA-136, RR-171, or QR-171). Thus, an important consideration is the frequency of these genotypes in different breeds of sheep. In this study, the genetic sequence for codons 104-175 was determined for at least ten animals of ten sheep breeds (n=207). Genotypes at codons 112, 136, 154, and 171 were determined. For codon 136, the frequency of the susceptible allele (V) was less than 0.20 in all breeds. In contrast, the frequency of the susceptible allele (Q) at codon 171 ranged from 0.27 (St. Croix) to 0.96 (Hampshire). In addition, a previously unreported substitution was found at codon 143 (H/R), with frequencies as high as 0.40
A high density recombination map of the pig reveals a correlation between sex-specific recombination and GC content
<p>Abstract</p> <p>Background</p> <p>The availability of a high-density SNP genotyping chip and a reference genome sequence of the pig (<it>Sus scrofa</it>) enabled the construction of a high-density linkage map. A high-density linkage map is an essential tool for further fine-mapping of quantitative trait loci (QTL) for a variety of traits in the pig and for a better understanding of mechanisms underlying genome evolution.</p> <p>Results</p> <p>Four different pig pedigrees were genotyped using the Illumina PorcineSNP60 BeadChip. Recombination maps for the autosomes were computed for each individual pedigree using a common set of markers. The resulting genetic maps comprised 38,599 SNPs, including 928 SNPs not positioned on a chromosome in the current assembly of the pig genome (build 10.2). The total genetic length varied according to the pedigree, from 1797 to 2149 cM. Female maps were longer than male maps, with a notable exception for SSC1 where male maps are characterized by a higher recombination rate than females in the region between 91–250 Mb. The recombination rates varied among chromosomes and along individual chromosomes, regions with high recombination rates tending to cluster close to the chromosome ends, irrespective of the position of the centromere. Correlations between main sequence features and recombination rates were investigated and significant correlations were obtained for all the studied motifs. Regions characterized by high recombination rates were enriched for specific GC-rich sequence motifs as compared to low recombinant regions. These correlations were higher in females than in males, and females were found to be more recombinant than males at regions where the GC content was greater than 0.4.</p> <p>Conclusions</p> <p>The analysis of the recombination rate along the pig genome highlighted that the regions exhibiting higher levels of recombination tend to cluster around the ends of the chromosomes irrespective of the location of the centromere. Major sex-differences in recombination were observed: females had a higher recombination rate within GC-rich regions and exhibited a stronger correlation between recombination rates and specific sequence features.</p
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