Basis for high-affinity ethylene binding by the ethylene receptor ETR1 of Arabidopsis.

The gaseous hormone ethylene is perceived in plants by membrane-bound receptors, the best studied of these being ETR1 from Arabidopsis. Ethylene receptors can mediate a response to ethylene concentrations at less than one part per billion; however, the mechanistic basis for such high-affinity ligand binding has remained elusive. Here we identify an Asp residue within the ETR1 transmembrane domain that plays a critical role in ethylene binding. Site-directed mutation of the Asp to Asn results in a functional receptor that has a reduced affinity for ethylene, but still mediates ethylene responses in planta. The Asp residue is highly conserved among ethylene receptor-like proteins in plants and bacteria, but Asn variants exist, pointing to the physiological relevance of modulating ethylene-binding kinetics. Our results also support a bifunctional role for the Asp residue in forming a polar bridge to a conserved Lys residue in the receptor to mediate changes in signaling output. We propose a new structural model for the mechanism of ethylene binding and signal transduction, one with similarities to that found in a mammalian olfactory receptor.

The cost-effectiveness of antenatal and postnatal education and support interventions for women aimed at promoting breastfeeding in the UK.

BACKGROUND: Breastfeeding is associated with health benefits to mothers and babies and cost-savings to the health service. Breastfeeding rates in the UK are low for various reasons including cultural barriers, inadequate support to initiate and sustain breastfeeding, lack of information, or choice not to breastfeed. Education and support interventions have been developed aiming at promoting breastfeeding rates. The objective of this study was to assess the cost-effectiveness of such interventions for women, initiated antenatally or in the first 8 weeks postnatally, aiming at improving breastfeeding rates, in the UK. METHODS: A decision-analytic model was constructed to compare costs and quality-adjusted life-years (QALYs) of a breastfeeding intervention from the perspective of health and personal social services in England. Data on intervention effectiveness and the benefits of breastfeeding were derived from systematic reviews. Other model input parameters were obtained from published sources, supplemented by expert opinion. RESULTS: The incremental cost-effectiveness ratio (ICER) of the modelled intervention added on standard care versus standard care was £51,946/QALY, suggesting that the intervention is not cost-effective under National Institute for Health and Care Excellence (NICE) criteria in England. Sensitivity analysis suggested that the cost-effectiveness of the intervention improved as its effectiveness increased and intervention cost decreased. At the base-case effect (increase in breastfeeding rates 16-26 weeks after birth by 19%), the intervention was cost-effective (<£20,000/QALY) if its cost per woman receiving the intervention became ≈£40-£45. At the base-case cost (£84), the intervention was cost-effective if it increased breastfeeding rates by at least 35-40%. CONCLUSIONS: Available breastfeeding interventions do not appear to be cost-effective under NICE criteria in England. Future breastfeeding interventions need to have higher effectiveness or lower cost compared with currently available interventions in order to become cost-effective. Public health and other societal interventions that protect, promote and support breastfeeding may be key in improving breastfeeding rates in the UK.

How Do Older Adults Decide to Visit the Emergency Department? Patient and Caregiver Perspectives.

Seniors account for a high number of emergency department (ED) visits, yet little is known about how they decide to visit the ED. This paper reports on the results of surveys completed by 264 seniors who visited the ED and their caregivers and interviews with a subset (N = 51) of survey respondents, aimed at understanding how they decide to visit the ED. Although older adults rely on others to help them decide whether to visit the ED, only a small proportion consult healthcare providers in doing so. Opportunities exist for enhancing seniors' decision-making process regarding ED visits and access to community-based healthcare to avoid ED visits.

Factors for Self-Managing Care Following Older Adults' Discharge from the Emergency Department: A Qualitative Study.

Cette étude avait pour but d'identifier les facteurs qui influent sur la capacité des personnes âgées à prendre en charge leur santé après une consultation au service des urgences (SU). Les questionnaires de l'enquête (n = 380) ont été remplis en SU par des personnes âgées et leurs aidants et visaient à évaluer leur perception de la compréhension de l'information qui leur était fournie. Des entrevues (n = 51) ont été réalisées avec un sous-échantillon de participants au cours des quatre semaines suivant leur consultation au SU et ont examiné les facteurs ayant une incidence sur l'autogestion des problèmes de santé. La perception de la compréhension de l'information reçue en SU (« oui, certainement ¼) était meilleure lors de la consultation au SU (91 %) que lors du suivi (71 %), lorsque 20 % des participants ne comprenaient pas ou n'étaient pas certains qu'ils avaient compris ce qui leur avait été communiqué en SU. Les patients ont rapporté que l'autogestion de leurs problèmes de santé était influencée par: la communication avec le personnel du SU, la compréhension des attentes suivant le congé de l'hôpital, l'état de santé, la disponibilité des aidants et divers facteurs externes. De plus, les soignants ont aussi mentionné l'appui aux soignants et la résistance des patients aux recommandations. L'utilisation de stratégies adaptées aux aînés en SU (p. ex. recommandations écrites, confirmation de la compréhension des recommandations), particulièrement celles liées à l'identification des personnes à risque et de celles nécessitant davantage de soutiens transitoires ou un meilleur accès ou intégration aux ressources disponibles dans la communauté amélioreraient l'autogestion des problèmes de santé suivant les consultations en SU.This study identified factors affecting seniors' ability to self-manage their health following an Emergency Department (ED) visit. Surveys (n = 380) completed by older adults and their caregivers in the ED assessed their understanding of information provided. Interviews (n = 51) completed with a participant subsample up to four weeks post-ED visit examined self-management factors. Perceived understanding of the information ("Yes, definitely") received in the ED was greater at the time of the visit (91%) than at follow-up (71%). Patients reported self-management was influenced by communication with ED staff, understanding of post-discharge expectations and the health condition(s), caregiver availability, and various external factors. Caregivers also identified support for caregivers and patient resistance to recommendations. Senior-friendly strategies (e.g., recommendations in writing, confirmed understanding of recommendations), particularly those related to identifying those at risk and needing greater transitional supports, and greater access to and integration with community supports could enhance post-ED self-management.

Captive Care, Raising, and Breeding of the Veiled Chameleon (Chamaeleo calyptratus).

Squamate reptiles comprise approximately one-third of all living amniotes. In most of these species, it is difficult to study gastrulation and neurulation because the embryos are at a late stage of development at the time of oviposition. This is not the case, however, in veiled chameleons (Chamaeleo calyptratus), which are increasingly being used as a model organism to study these and other developmental and evolutionary phenomena. Originating from the Arabian Peninsula, veiled chameleons are arboreal specialists that possess extensive morphological specializations for climbing. They naturally inhabit semitropical habitats, but they also have an almost 30-yr history of being bred in captivity. Veiled chameleons breed readily and do not require a period of cooling to induce the reproductive cycle, and females can produce ∼45-90 eggs multiple times per year. Thus, compared with other reptiles, relatively few animals are needed to maintain a productive breeding colony. Herein, we present the conditions, equipment, and techniques required for proper husbandry and breeding of veiled chameleons within a laboratory environment.

The Veiled Chameleon (Chamaeleo calyptratus Duméril and Duméril 1851): A Model for Studying Reptile Body Plan Development and Evolution.

Vertebrate model organisms have facilitated the discovery and exploration of morphogenetic events and developmental pathways that underpin normal and pathological embryological events. In contrast to amniotes such as Mus musculus (Mammalia) and Gallus gallus (Aves), our understanding of early patterning and developmental events in reptiles (particularly nonavians) remains weak. Squamate reptiles (lizards, snakes, and amphisbaenians) comprise approximately one-third of all living amniotes. But studies of early squamate development have been limited because, in most members of this lineage, embryo development at the time of oviposition is very advanced (limb bud stages and older). In many cases, squamates give birth to fully developed offspring. However, in the veiled chameleon (Chamaeleo calyptratus), embryos have progressed only to a primitive pregastrula stage at the time of oviposition. Furthermore, the body plan of the veiled chameleon is highly specialized for climbing in an arboreal environment. It possesses an entire suite of skeletal and soft anatomical modifications, including cranioskeletal ornamentation, lingual anatomy and biomechanics for projection, autopodial clefting for grasping, adaptations for rapid integumental color changes, a prehensile tail with a lack of caudal autotomy, the loss of the tympanum in the middle ear, and the acquisition of turreted eyes. Thus, C. calyptratus is an important model organism for studying the role of ecological niche specialization, as well as genetic and morphological evolution within an adaptive framework. More importantly, this species is easily bred in captivity, with only a small colony (<10 individuals) needed to obtain hundreds of embryos every year.

Psychometric properties of the modified RESIDE physical activity questionnaire among low-income overweight women.

OBJECTIVES: This study explored the criterion-related validity and test-retest reliability of the modified RESIDential Environment physical activity questionnaire and whether the instrument's validity varied by body mass index, education, race/ethnicity, or employment status. DESIGN: Validation study using baseline data collected for randomized trial of a weight loss intervention. METHODS: Participants recruited from health departments wore an ActiGraph accelerometer and self-reported non-occupational walking, moderate and vigorous physical activity on the modified RESIDential Environment questionnaire. We assessed validity (n=152) using Spearman correlation coefficients, and reliability (n=57) using intraclass correlation coefficients. RESULTS: When compared to steps, moderate physical activity, and bouts of moderate/vigorous physical activity measured by accelerometer, these questionnaire measures showed fair evidence for validity: recreational walking (Spearman correlation coefficients 0.23-0.36), total walking (Spearman correlation coefficients 0.24-0.37), and total moderate physical activity (Spearman correlation coefficients 0.18-0.36). Correlations for self-reported walking and moderate physical activity were higher among unemployed participants and women with lower body mass indices. Generally no other variability in the validity of the instrument was found. Evidence for reliability of RESIDential Environment measures of recreational walking, total walking, and total moderate physical activity was substantial (intraclass correlation coefficients 0.56-0.68). CONCLUSIONS: Evidence for questionnaire validity and reliability varied by activity domain and was strongest for walking measures. The questionnaire may capture physical activity less accurately among women with higher body mass indices and employed participants. Capturing occupational activity, specifically walking at work, may improve questionnaire validity.

Geriatrics, interprofessional practice, and interorganizational collaboration: a knowledge-to-practice intervention for primary care teams.

INTRODUCTION: Caring for frail seniors requires health professionals with skills and knowledge in 3 core competencies: geriatrics, interprofessional practice, and interorganizational collaboration. Despite a growing population of frail seniors in all developed countries, significant gaps exist in preparation of health professionals in these skills. To help close these gaps, a knowledge-to-practice (KTP) process was undertaken to increase the capacity of newly created family health teams and longer standing Community Health Centers in the Province of Ontario, Canada. METHODS: Each team identified a staff member to become its facilitator in the 3 core skill sets. Guided by a KTP framework, a set of training modules were created, compiled into a digital toolkit for transfer into practice, translated in a multimethods workshop, and implemented using a variety of strategies to optimize practice change. RESULTS: Staff from 82% of the targeted primary care teams learned to use the toolkit in a train-the-facilitator process that was highly valued, and prompted a range of changes in personal and team practice. A digital toolkit for primary care teams remains an enduring and often used resource. DISCUSSION: Closing the knowledge gap in the core competencies for frailty focused care is complex. A KTP framework helped guide a staged multimethod process that produced both individual and team practice change and on online toolkit that has a continuing influence.