Farm diversification, entrepreneurship and technology adoption:Analysis of upland farmers in Wales

Farm businesses face increasing challenges in the face of policy reform which envisages multifunctional rural economies with objectives which span the environmental, the social as well as the production of food. This leads to uncertainties and ambiguities in the way in which farms respond to incentives and pressures to become entrepreneurial, to diversify, to become more efficient at food production and to adopt new technology. This paper examines these tensions in the context of upland agricultural business in rural Wales. Qualitative and quantitative results support a conclusion of significant heterogeneity in farm response, and highlight tensions between maintaining a focus towards current on-farm activity or pursuing entrepreneurial diversification, as well as differing levels of technology adoption in support of these income streams. Supported by a descriptive cluster analysis based on survey data, the paper proposes a new conceptual categorisation of entrepreneurial strategy, distinguished on the basis of attitudes towards on- and off-farm income generation and on stated stance towards current and future policy grant streams. The paper discusses some of the factors that may determine how particular farmers and farming businesses lie within this categorisation

Studies of Insulin Sensitivity Using the Euglycaemic Hyperinsulinaemic Clamp

A series of studies which have utilised the euglycaemic hyperinsulinaemic clamp to measure insulin sensitivity is described. The methods for measuring insulin sensitivity have been evaluated and conclusions drawn about reproducibility and inherent limitations of the technique. The euglycaemic clamp has been used to examine the effects of angiotensin II and antihypertensive drugs on insulin sensitivity in normal subjects, patients with essential hypertension and patients with impaired glucose tolerance or non-insulin dependent diabetes mellitus (NIDDM). Each individual study was approved by the local Research and Ethical Committee and informed consent was obtained from each subject before participation in a study. (i) Evaluation of the euglvcaemic hvperinsulinaemic clamp technique. It was recognised that despite widespread use of the euglycaemic clamp in clinical research, key aspects of the technique remained to be validated. (a) The intra- and inter-subject variability in insulin sensitivity and the time for insulin mediated glucose disposal to reach steady state were evaluated in 18 healthy male subjects and 6 patients with essential hypertension who attended two study days when a euglycaemic hyperinsulinaemic clamp was performed. Measurements of insulin sensitivity derived from the euglycaemic hyperinsulinaemic clamp were expressed as whole body glucose uptake (M), and the insulin sensitivity index (SIP). M values at 120 mins were significantly less than at 180 mins in both the healthy subjects and in the hypertensive patients indicating a progressive increase in glucose utilisation over the 180 minutes. The intra subject coefficient of variation (c.v.) of M at 120 mins and 180 mins was 8% and 6% for healthy subjects and 14% and 5% for patients with essential hypertension respectively. The inter subject c.v. of M at 120 mins and 180 mins was 22% and 21% for healthy subjects and 43% and 38% for patients with essential hypertension. The intra subject c.v. of the insulin stimulus was 10% in both groups. The intra subject c.v. of the was 21% for healthy subjects and 16% for patients with essential hypertension. Thus, it was demonstrated that the clamp is highly reproducible within subjects but the inter subject variability is wide. Clamps of 120 min duration underestimate M by up to 10% and are not as reproducible in patients with essential hypertension. The SIP is poorly reproducible; my data suggest that the M value is a better index for comparison of possible changes in insulin sensitivity. (b) The need to arterialise venous blood with a heated hand box was evaluated in 6 healthy subjects. Each subject attended 2 study days when a euglycaemic hyperinsulinaemic clamp was performed and "arterialised" (AV; heated hand vein) and mixed venous blood (MV; antecubital fossa) were collected simultaneously for the measurement of plasma glucose and oxygen saturations It was demonstrated that AV blood was effectively arterialised achieving oxygen saturations of 95+2%, and that plasma glucose concentrations were less variable when compared with MV samples. (c) The haemodynamic and metabolic effects of hand warming were evaluated in 6 healthy male subjects who attended 2 study days when a euglycaemic hyperinsulinaemic clamp was performed. On the first day AV blood was used to adjust the glucose infusion rate required to maintain euglycaemia; on the second study day MV blood was used. The results demonstrate that there was a significant trend for M values to be higher when arterialised blood was used when compared with mixed venous blood. My results suggest that hand warming may induce a blood pressure lowering effect that is associated with a confounding increase in the derived measurement of insulin sensitivity. (ii) Evaluation of the effects of lacidipine on insulin sensitivity. The acute and chronic (2 weeks) effects of the dihydropyridine calcium antagonist, lacidipine (4 mg daily), on insulin mediated metabolic responses was evaluated in a double-blind placebo-controlled crossover study in 12 healthy subjects and 6 patients with essential hypertension. Each subject attended 4 study days when insulin sensitivity was evaluated using the euglycaemic hyperinsulinaeniic clamp. In the healthy subjects, reflex tachycardia was observed after lacidipine administration but neither first dose nor 2 weeks of lacidipine treatment altered insulin sensitivity when compared with placebo. A significant decrease in fasting triglyceride concentrations was observed after 2 weeks lacidipine treatment. 95% confidence intervals excluded a 15% change in whole body glucose uptake. In the hypertensive patients, lacidipine treatment was associated with reflex tachycardia and a trend towards decreased blood pressure but there was no significant effect on whole body insulin sensitivity. (Abstract shortened by ProQuest.)

Field-calibrated model of melt, refreezing, and runoff for polar ice caps : Application to Devon Ice Cap

Acknowledgments R.M.M. was supported by the Scottish Alliance for Geoscience, Environment and Society (SAGES). The field data collection contributed to the validation of the European Space Agency Cryosat mission and was supported by the Natural Sciences and Engineering Research Council, Canada, the Meteorological Service of Canada (CRYSYS program), the Polar Continental Shelf Project (an agency of Natural Resources Canada), and by UK Natural Environment Research Council consortium grant NER/O/S/2003/00620. Support for D.O.B. was provided by the Canadian Circumpolar Institute and the Climate Change Geoscience Program, Earth Sciences Sector, Natural Resources Canada (ESS contribution 20130371). Thanks are also due to the Nunavut Research Institute and the communities of Resolute Bay and Grise Fjord for permission to conduct fieldwork on Devon Ice Cap. M.J. Sharp, A. Gardner, F. Cawkwell, R. Bingham, S. Williamson, L. Colgan, J. Davis, B. Danielson, J. Sekerka, L. Gray, and J. Zheng are thanked for logistical support and field assistance during the data collection. We thank Ruzica Dadic, two other anonymous reviewers, and the Editor, Bryn Hubbard, for their helpful comments on an earlier version of this paper and which resulted in significant improvements.Peer reviewedPublisher PD

Introducing IR to Medical Students Interested in Primary Care Specialties

Introduction: Over the last several years, interventional radiologists have become increasingly recognized as part of a collaborative healthcare team. At the same time, interventional radiology (IR) is a field poorly represented in many medical school curricula. As IR management options are increasingly incorporated into the clinician’s arsenal, representation during medical education is critical. Several studies have demonstrated that interventional radiology interest group (IRIG) presentations and demonstrations increase knowledge and excitement about the specialty amongst medical students. However, current literature investigating the effect of these presentations on students interested in primary care specialties is lacking. Our study demonstrates that presenting cases specifically targeted toward students interested in primary care specialties increases their knowledge about the role of IR in their future practice.Methods: Case presentations were given to students who attended interest group meetings in family medicine, emergency medicine, pediatrics, and internal medicine. Presentations were developed specifically to consist of cases that are relevant to each interest group’s respective field. The majority of students were in their preclinical years and interested in a variety of non-radiology specialties. Surveys were administered prior to the presentation and following the presentation (7 questions each). All questions were answered on a Likert scale of 1-5 (1—disagree and 5—agree). Questions were centered around general knowledge of IR, the role of IR within their field, and the benefits of IR to their future practice. Descriptive statistics were calculated based on these results.Results: Responses from 81 participants to every question suggested an overall increase in the knowledge of the field of IR following the case presentation. The mean value to the question “I understand the role of IR in my specialty of interest” increased from 2.7 to 3.6 after the presentation. Students’ average response to the question, “I understand some IR procedures” increased 1.3 points on the scale.Conclusions: Medical students are generally not exposed to IR as a specialty despite its expanding role in clinical practice. Increasing medical student familiarity with IR is essential to producing physicians with a broad understanding of the management options at their disposal. Targeted case presentations given to pre-clinical and clerkship-level medical students interested in primary care specialties were effective in increasing understanding of the role of IR in their specialty of interest. Student-led presentations using interest groups as a networking platform are an effective method for forming first impressions and exposing future doctors to the applications of interventional radiology in their practice.https://scholarlycommons.henryford.com/merf2019edu/1001/thumbnail.jp

Two-Stage Two-Locus Models in Genome-Wide Association

Studies in model organisms suggest that epistasis may play an important role in the etiology of complex diseases and traits in humans. With the era of large-scale genome-wide association studies fast approaching, it is important to quantify whether it will be possible to detect interacting loci using realistic sample sizes in humans and to what extent undetected epistasis will adversely affect power to detect association when single-locus approaches are employed. We therefore investigated the power to detect association for an extensive range of two-locus quantitative trait models that incorporated varying degrees of epistasis. We compared the power to detect association using a single-locus model that ignored interaction effects, a full two-locus model that allowed for interactions, and, most important, two two-stage strategies whereby a subset of loci initially identified using single-locus tests were analyzed using the full two-locus model. Despite the penalty introduced by multiple testing, fitting the full two-locus model performed better than single-locus tests for many of the situations considered, particularly when compared with attempts to detect both individual loci. Using a two-stage strategy reduced the computational burden associated with performing an exhaustive two-locus search across the genome but was not as powerful as the exhaustive search when loci interacted. Two-stage approaches also increased the risk of missing interacting loci that contributed little effect at the margins. Based on our extensive simulations, our results suggest that an exhaustive search involving all pairwise combinations of markers across the genome might provide a useful complement to single-locus scans in identifying interacting loci that contribute to moderate proportions of the phenotypic variance

Optimizing astrophotonic spatial reformatters using simulated on-sky performance

One of the most useful techniques in astronomical instrumentation is image slicing. It enables a spectrograph to have a more compact angular slit, whilst retaining throughput and increasing resolving power. Astrophotonic components like the photonic lanterns and photonic reformatters can be used to replace bulk optics used so far. This study investigates the performance of such devices using end-to-end simulations to approximate realistic on-sky conditions. It investigates existing components, tries to optimize their performance and aims to understand better how best to design instruments to maximize their performance. This work complements the recent work in the field and provides an estimation for the performance of the new components.Comment: Conference proceedings in SPIE 2018 Austin Texa