The Causal Economy Approach to Scientific Explanation

This paper sketches a causal account of scientific explanation designed to sustain the judgment that high-level, detail-sparse explanations—particularly those offered in biology—can be at least as explanatorily valuable as lower-level counterparts. The motivating idea is that complete explanations maximize causal economy: they cite those aspects of an event’s causal run-up that offer the biggest-bang-for-your-buck, by costing less (in virtue of being abstract) and delivering more (in virtue making the event stable or robust)

MHD Disc Winds and Linewidth Distributions

We study AGN emission line profiles combining an improved version of the accretion disc-wind model of Murray & Chiang with the magneto-hydrodynamic model of Emmering et al. We show how the shape, broadening and shift of the C IV line depend not only on the viewing angle to the object but also on the wind launching angle, especially for small launching angles. We have compared the dispersions in our model C IV linewidth distributions to observational upper limit on that dispersion, considering both smooth and clumpy torus models. As the torus half-opening angle (measured from the polar axis) increases above about 18? degrees, increasingly larger wind launching angles are required to match the observational constraints. Above a half-opening angle of about 47? degrees, no wind launch angle (within the maximum allowed by the MHD solutions) can match the observations. Considering a model that replaces the torus by a warped disc yields the same constraints obtained with the two other models

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Scenes from January Term 2006; clockwise from top left, Austrialia, India and Londo

Just-in-Time Learning: Web-Based/Internet Delivered Instruction

The focus of this paper is to demonstrate how the use of advanced technologies in the classroom facilitate teaching effectiveness and student development of these higher order cognitive skills. Use of technology in course design allows flexibility, adaptation, and “just-in-time” delivery of course material. Just-in-time delivery allows the capability to uniquely customize course material in a matter of moments. The power of this method of delivery includes the capability to present time or reference sensitive information, to allow criss-crossing of knowledge, and to present the most current and up-to-date information available

A practical framework for harmonising welfare and quality of data output in the laboratory-housed dog

In the UK, laboratory-housed dogs are primarily used as a non-rodent species in the safety testing of new medicines and other chemical entities. The use of animals in research is governed by the Animals (Scientific Procedures) Act (1986, amended 2012) and legislation is underpinned by the principles of humane experimental technique: Replacement, Reduction and Refinement. A link between animal welfare and the quality of data produced has been shown in other species (e.g. rodents, nonhuman primates), however, no established, integrated methodology for identifying or monitoring welfare and quality of data output previously existed in the laboratory-housed dog. In order to investigate the effects of planned Refinements to various aspects of husbandry and regulated procedures, this project sought to integrate behavioural, physiological and other measures (e.g. cognitive bias, mechanical pressure threshold) and to provide a means for staff to monitor welfare whilst also establishing the relationship between welfare and quality of data output. Affective state was identified using an established method of cognitive bias testing, before measuring welfare at ‘baseline’ using measures of behaviour and physiology. Dogs then underwent ‘positive’ and ‘negative’ behavioural challenges to identify the measures most sensitive to changing welfare and most suitable for use in a framework. The resulting Welfare Assessment Framework, developed in three groups of dogs from contrasting backgrounds within the facility, found a consistent pattern of behaviour, cardiovascular function, affect and mechanical pressure threshold (MPT). Dogs with a negative affective state had higher blood pressure at baseline than those with positive affective states, and the magnitude of the effect of negative welfare suggests that welfare may act as a confound in the interpretation of cardiovascular data. The responses to restraint included increases in blood pressure and heart rate measures which approached ceiling levels, potentially reducing the sensitivity of measurement. If maintained over time this response could potentially have a negative health impact on other organ systems and affecting the data obtained from those. Dogs with a negative welfare state also had a lower mechanical pressure threshold, meaning they potentially experienced greater stimulation from unpleasant physical stimuli. Taken together with the behaviours associated with a negative welfare state (predominantly vigilant or stereotypic behaviours) the data suggest that dogs with a negative welfare state have a greater behavioural and physiological response to stimuli in their environment; as such, data obtained from their use is different from that obtained from dogs with a positive welfare state. This was confirmed by examining the effect size (Cohen’s d ) resulting from the analysis of affective state on cardiovascular data. An increase in variance, particularly in the small dog numbers typical of safety assessment studies, means a reduction in the power of the study to detect the effect under observation; a decrease in variation has the potential to reduce the number of dogs use, in line with the principle of Reduction and good scientific practice. The development of the framework also identified areas of the laboratory environment suitable for Refinement (e.g. restriction to single-housing and restraint) and other easily-implemented Refinements (e.g. feeding toy and human interaction) which could be used to improve welfare. As a result of this, a Welfare Monitoring Tool (WMT) in the form of a tick sheet was developed for technical and scientific staff to identify those dogs at risk of reduced welfare and producing poor quality data, as well as to monitor the effects of Refinements to protocols. Oral gavage is a common regulated procedure, known to be potentially aversive and was identified as an area in need of Refinement. A program of desensitisation and positive reinforcement training was implemented in a study also comparing the effects of a sham dose condition versus a control, no-training, condition. A number of the measures used, including home pen behaviour, behaviour during dosing, MPT and the WMT showed significant benefits to the dogs in the Refined condition. Conversely, dogs in the sham dose condition showed more signs of distress and took longer to dose than dogs in the control condition. The welfare of control dogs was intermediate to sham dose and Refined protocol dogs. This project identified a positive relationship between positive welfare and higher quality of data output. It developed and validated a practical and feasible means of measuring welfare in the laboratory environment in the Welfare Assessment Framework, identified areas in need of Refinement and developed practical ways to implement such Refinements to husbandry and regulated procedures. As such it should have wide implications for the pharmaceutical industry and other users of dogs in scientific research

Barriers To Eye Care Among Patients With Age-Related Macular Degeneration In The Yale Eye Center

Barriers to obtaining medical care have been studied extensively across the health care realm. Within ophthalmology barriers to receiving care for cataracts and diabetic retinopathy (DR) have been considered. To the best of our knowledge, the barriers to receiving care for those suffering from age-related macular degeneration (AMD) in the United States have not been explicitly studied. AMD is a disease that disproportionally affects the elderly and when left untreated will often cause legal blindness. Early detection and treatment is essential to avert AMD progression. Studying the way in which patients receive their eye care and what barriers or enabling factors they may experience when receiving this care is crucial. We hypothesize that barriers to care for patients with age-related macular degeneration are necessarily distinct from those barriers already identified affecting patients with diabetic retinopathy as the patient population is necessarily distinct. This study aims to: 1) to assess patient\u27s understanding of age-related macular degeneration and its disease types, treatment options, and long-term sequelae; 2) to elicit patient\u27s views on and concerns about their eye care; 3) to ascertain the most frequently perceived barriers and enabling factors to seeking care amongst patients with age-related macular degeneration at the Yale Eye Center; and 4) to develop a questionnaire using the information gained from aims 1-3 that can be self-administered by Yale Eye Center age-related macular degeneration and diabetic retinopathy patients. To accomplish this goal a qualitative approach was taken consisting of semi-structured interviews conducted with Yale Eye Center (YEC) patients with AMD and DR. All interviews were transcribed and coded to identify emerging themes. We found that patients with age-related macular degeneration have some similar and some unique barriers as compared to patients with diabetic retinopathy. Major deterrents include: 1) confusion and limited knowledge of AMD, 2) access to specialist care, 3) financial constraints, 4) difficulty buying and locating, and unsure of indications for taking, AREDS2, 5) frequency and length of clinic visits, and 6) fear of requiring an intravitreal injection. The key enabling factors that motivated patients to seek care are their positive attitudes about vision and eye care and confidence in their providers. With the knowledge gained from these semi-structured interviews, physicians can direct their attention to these focal issues in order to provide the best and most effective patient care. A formal questionnaire was developed using the insight gained from these interviews and this will provide large-scale standardized data to make further generalizations in the field