Measuring Impatience: Elicited Discount Rates and the Barratt Impulsiveness Scale

We explore intertemporal decision making to test the extent to which elicited discount rates and a self-reported scale of impatience measure the same behavioral characteristic. We conduct experiments in which we elicit discount rates using monetary rewards and a self-reported measure of impatience (the Barratt Impulsiveness Scale, BIS-11). Although researchers have utilized these measures to infer aspects of intertemporal preferences, we find no significant correlation between discount rates and the BIS-11 except in the special case where discount rates were elicited after individuals were primed with negative feedback.intertemporal choice; impulsiveness; discounting; experiments

Social Interactions and the Salience of Social Identity

In this paper, we explore the effect of identity salience on behavior in a simple social interaction. Specifically, we compare behavior in a ultimatum game across three treatments: priming subjects with a shared identity, priming subjects with an identity distinct from those with whom they will interact, and priming subjects with no particular identity. We find that subjects are most cooperative in the identity-priming treatment and least cooperative in the distinctiveness-priming treatment. Similarly, subjects reveal the highest demands in the identity-priming treatment and the lowest demands in the distinctiveness-priming treatment. We discuss the implications of these results with respect to literature on organizational identity.identity, experiments, bargaining

Speed control with low armature loss for very small sensorless brushed DC motors

A method for speed control of brushed dc motors is presented. It is particularly applicable to motors with armatures of less than 1 cm3. Motors with very small armatures are difficult to control using the usual pulsewidth-modulation (PWM) approach and are apt to overheat if so driven. The technique regulates speed via the back electromotive force but does not require current-discontinuous drives. Armature heating in small motors under PWM drive is explained and quantified. The method is verified through simulation and measurement. Control is improved, and armature losses are minimized. The method can expect to find application in miniature mechatronic equipment

Can food vouchers improve nutrition and reduce health inequalities in low-income mothers and young children: A multi-method evaluation of the experiences of beneficiaries and practitioners of the Healthy Start programme in England

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.Background: Good nutrition is important during pregnancy, breastfeeding and early life to optimise the health of women and children. It is difficult for low-income families to prioritise spending on healthy food. Healthy Start is a targeted United Kingdom (UK) food subsidy programme that gives vouchers for fruit, vegetables, milk, and vitamins to low-income families. This paper reports an evaluation of Healthy Start from the perspectives of women and health practitioners. Methods. The multi-method study conducted in England in 2011/2012 included focus group discussions with 49 health practitioners, an online consultation with 620 health and social care practitioners, service managers, commissioners, and user and advocacy groups, and qualitative participatory workshops with 85 low-income women. Additional focus group discussions and telephone interviews included the views of 25 women who did not speak English and three women from Traveller communities. Results: Women reported that Healthy Start vouchers increased the quantity and range of fruit and vegetables they used and improved the quality of family diets, and established good habits for the future. Barriers to registration included complex eligibility criteria, inappropriate targeting of information about the programme by health practitioners and a general low level of awareness among families. Access to the programme was particularly challenging for women who did not speak English, had low literacy levels, were in low paid work or had fluctuating incomes. The potential impact was undermined by the rising price of food relative to voucher value. Access to registered retailers was problematic in rural areas, and there was low registration among smaller shops and market stalls, especially those serving culturally diverse communities. Conclusions: Our evaluation of the Healthy Start programme in England suggests that a food subsidy programme can provide an important nutritional safety net and potentially improve nutrition for pregnant women and young children living on low incomes. Factors that could compromise this impact include erosion of voucher value relative to the rising cost of food, lack of access to registered retailers and barriers to registering for the programme. Addressing these issues could inform the design and implementation of food subsidy programmes in high income countries. © 2014 McFadden et al.; licensee BioMed Central Ltd.The Policy Research Programme in the Department of Health, UK

Kinetic and pH Studies on Human Phenylethanolamine N-Methyltransferase

Phenylethanolamine N-methyltransferase (PNMT) catalyzes the conversion of norepinephrine (noradrenaline) to epinephrine (adrenaline) while, concomitantly, S-adenosyl-l-methionine (AdoMet) is converted to S-adenosyl-l-homocysteine. This reaction represents the terminal step in catecholamine biosynthesis and inhibitors of PNMT have been investigated, inter alia, as potential antihypertensive agents. At various times the kinetic mechanism of PNMT has been reported to operate by a random mechanism, an ordered mechanism in which norepinephrine binds first, and an ordered mechanism in which AdoMet binds first. Here we report the results of initial velocity studies on human PNMT in the absence and presence of product and dead end inhibitors. These, coupled with isothermal titration calorimetry and fluorescence binding experiments, clearly shown that hPNMT operates by an ordered sequential mechanism in which AdoMet binds first. Although the log V pH-profile was not well defined, plots of log V/K versus pH for AdoMet and phenylethanolamine, as well as the pKi versus pH for the inhibitor, SK&F 29661, were all bell-shaped indicating that a protonated and an unprotonated group are required for catalysis

Codivergence and multiple host species use by fig wasp populations of the Ficus pollination mutualism

<p>Abstract</p> <p>Background</p> <p>The interaction between insects and plants takes myriad forms in the generation of spectacular diversity. In this association a species host range is fundamental and often measured using an estimate of phylogenetic concordance between species. Pollinating fig wasps display extreme host species specificity, but the intraspecific variation in empirical accounts of host affiliation has previously been underestimated. In this investigation, lineage delimitation and codiversification tests are used to generate and discuss hypotheses elucidating on pollinating fig wasp associations with <it>Ficus</it>.</p> <p>Results</p> <p>Statistical parsimony and AMOVA revealed deep divergences at the <it>COI </it>locus within several pollinating fig wasp species that persist on the same host <it>Ficus </it>species. Changes in branching patterns estimated using the generalized mixed Yule coalescent test indicated lineage duplication on the same <it>Ficus </it>species. Conversely, <it>Elisabethiella </it>and <it>Alfonsiella </it>fig wasp species are able to reproduce on multiple, but closely related host fig species. Tree reconciliation tests indicate significant codiversification as well as significant incongruence between fig wasp and <it>Ficus </it>phylogenies.</p> <p>Conclusions</p> <p>The findings demonstrate more relaxed pollinating fig wasp host specificity than previously appreciated. Evolutionarily conservative host associations have been tempered by horizontal transfer and lineage duplication among closely related <it>Ficus </it>species. Independent and asynchronistic diversification of pollinating fig wasps is best explained by a combination of both sympatric and allopatric models of speciation. Pollinator host preference constraints permit reproduction on closely related <it>Ficus </it>species, but uncertainty of the frequency and duration of these associations requires better resolution.</p

Predicting the Effects of Cerulean Warbler, Dendroica cerulea Management on Eastern Ontario Bird Species

Single-species habitat management strategies are often undertaken without explicit consideration of their effects on the larger community. Here we explore the potential effects of managing eastern Ontario deciduous forests for the Cerulean Warbler (Dendroica cerulea) by examining its potential as a biodiversity indicator species and as an umbrella species. Our results indicate that the Cerulean Warbler would not be an effective biodiversity indicator, as its distribution across the studied landscape did not coincide with areas of high avian species richness. However, the Cerulean Warbler may be effective as an umbrella species for the maintenance of populations of other canopy-nesting species that require mature deciduous forest habitats. It is hoped that the conclusions reached in Ontario, while perhaps not directly transferable to all parts of the breeding range, encourage other Cerulean Warbler researchers to ask similar questions in their study areas