Distance measurement by delayed optical feedback in a ring laser

We numerically study the behavior of a semiconductor ring laser subject to bidirectional delayed optical feedback, when the isolated laser is in the quasi-unidirectional regime. The optical feedback, provided by two external refectors located in front of the ring output waveguides, can modify the laser regime produced by the cross-saturation between the clockwise and the counter-clockwise mode. Thus, the system exhibits new diferent regimes, most of which are asymmetric and bidirectional, with alternating dominant mode. Two of these regimes are of special interest in view of applications, because the laser switching period, between the clockwise and the counter-clockwise mode, is linearly related to the time of fight from the laser to one or both refectors. In these operating conditions, the laser is thus suitable to implement a telemeter. A convenient electrical output signal is obtained by a photodiode located behind one (partially refecting) fxed mirror, or by measuring the voltage drop across the laser junction. Simulations are performed by mathematical models based on rate-equations, assuming typical literature parameters for a 1 mW ring laser

Presentación Proyecto “Infancia(s) en riesgo”

Fundamentación del proyecto: Este proyecto se funda en el reconocimiento de la situación de vulnerabilidad, pobreza y por tanto de exclusión social en la que se encuentra la infancia, particularmente en la provincia de San Luis, en donde en muchos casos existe la imposibilidad de acceso masivo a la AUH (Asignación Universal por Hijo) y a la no adhesión a la ley 26061 de Protección Integral a Niños/as y Adolescentes. Condiciones que se hacen evidente en los alumnos de la escuela Juan B. Alberdi, caracterizada como urbano marginal, en donde la problemática se traduce en fracaso escolar (ausentismo que deviene en repitencia), violencia, agresividad, desnutrición, entre otros. Anclados en el paradigma de los derechos humanos, que entiende a la familia como sujeto de derechos, el propósito de este proyecto radica en el imperativo de reconocer necesidades de las familias de los alumnos, en tanto derechos vulnerados a fin de iniciar y acompañar un proceso de cambio estable y perdurable en el tiempo. Se trabajará con la metodología de talleres con directivos y docentes ofreciendo herramientas que les permitan no solo reconocer diversas situaciones problemáticas sino también contener; y con entrevistas en profundidad con las familias de los alumnos a fin de detectar necesidades e iniciar el proceso de intervención conducente al cambio. Objetivos: Reconocer el escenario institucional (políticas implementadas, actores involucrados), Lograr un acercamiento a la realidad contextual (habitus, campo) de las familias de los alumnos, Problematizar junto a docentes y directivos la concepción de niñez que forma parte de sus habitus, teniendo en cuenta los atravesamientos contextuales de esta época, Promover la incorporación de la promoción de derechos humanos en Gral. y del niño en particular, como un contenido transversal en la currícula. Realizar un diagnóstico de las familias de los alumnos de la escuela, Diseñar el proceso de intervención, priorizando demandas, necesidades y satisfactores en los cuales se intervendrá, •Iniciar un proceso de transformación de la situación inicial, junto a familias priorizadas. Articulación Docencia y Extensión: Se articularán acciones entre Taller de práctica I, III, y V; Trabajo Social IV y Derecho de familiar, específicamente en las actividades propuestas, como así también en la bibliografía y material de estudio, y en la escritura de ponencias a congresos acordes a la temática y a las actividades extensionistas

Selecting and implementing overview methods: implications from five exemplar overviews

This is the final version of the article. Available from BioMed Central via the DOI in this record.Background Overviews of systematic reviews are an increasingly popular method of evidence synthesis; there is a lack of clear guidance for completing overviews and a number of methodological challenges. At the UK Cochrane Symposium 2016, methodological challenges of five overviews were explored. Using data from these five overviews, practical implications to support methodological decision making of authors writing protocols for future overviews are proposed. Methods Methods, and their justification, from the five exemplar overviews were tabulated and compared with areas of debate identified within current literature. Key methodological challenges and implications for development of overview protocols were generated and synthesised into a list, discussed and refined until there was consensus. Results Methodological features of three Cochrane overviews, one overview of diagnostic test accuracy and one mixed methods overview have been summarised. Methods of selection of reviews and data extraction were similar. Either the AMSTAR or ROBIS tool was used to assess quality of included reviews. The GRADE approach was most commonly used to assess quality of evidence within the reviews. Eight key methodological challenges were identified from the exemplar overviews. There was good agreement between our findings and emerging areas of debate within a recent published synthesis. Implications for development of protocols for future overviews were identified. Conclusions Overviews are a relatively new methodological innovation, and there are currently substantial variations in the methodological approaches used within different overviews. There are considerable methodological challenges for which optimal solutions are not necessarily yet known. Lessons learnt from five exemplar overviews highlight a number of methodological decisions which may be beneficial to consider during the development of an overview protocol.The overview conducted by Pollock [19] was supported by a project grant from the Chief Scientist Office of the Scottish Government. The overview conducted by McClurg [21] was supported by a project grant by the Physiotherapy Research Foundation. The overview by Hunt [22] was supported as part of doctoral programme funding by the National Institute for Health Research (NIHR) Collaboration for Leadership in Applied Health Research and Care South West Peninsula (PenCLAHRC). The overview conducted by Estcourt [20] was supported by an NIHR Cochrane Programme Grant for the Safe and Appropriate Use of Blood Components. The overview conducted by Brunton [23] was commissioned by the Department of Health as part of an ongoing programme of work on health policy research synthesis. Alex Pollock is employed by the Nursing, Midwifery and Allied Health Professions (NMAHP) Research Unit, which is supported by the Chief Scientist Office of the Scottish Government. Pauline Campbell is supported by the Chief Nurses Office of the Scottish Government

Systematic Reviews in Educational Research: Methodology, Perspectives and Application

This chapter explores the processes of reviewing literature as a research method. The logic of the family of research approaches called systematic review is analysed and the variation in techniques used in the different approaches explored using examples from existing reviews. The key distinctions between aggregative and configurative approaches are illustrated and the chapter signposts further reading on key issues in the systematic review process

The impact of Baby Friendly Initiative accreditation: An overview of systematic reviews

Abstract: Despite its reported benefits, breastfeeding rates are low globally, and support systems such as the Baby Friendly Initiative (BFI) have been established to support healthy infant feeding practices and infant bonding. Increasingly reviews are being undertaken to assess the overall impact of BFI accreditation. A systematic synthesis of current reviews has therefore been carried out to examine the state of literature on the effects of BFI accreditation. A systematic search of CINAHL, MEDLINE, Maternal and Infant Health, Scopus, the Cochrane Library and PROSPERO was undertaken. Study selection, data extraction and critical appraisal of included reviews using the AMSTAR‐2 tool were undertaken by two authors, with disagreements resolved through discussion with the third author. Due to heterogeneity, a narrative synthesis of findings was applied. Fourteen reviews met the inclusion criteria. Overall confidence in the results of the review was rated as high for three reviews, low for two reviews and critically low for nine reviews. Most evidence suggests some increase in breastfeeding initiation, exclusivity and duration of breastfeeding, and one main trial suggests decreased gastrointestinal infection and allergic dermatitis in infants. However, overall certainty in the evidence was rated as very low across all outcomes due to concerns over risk of bias within and heterogeneity between the original studies. More contemporary, good‐quality randomised controlled trials or well‐controlled prospective comparative cohorts are required to better evaluate the impact of full BFI accreditation, with particular attention paid to the context of the research and to long‐term maternal and infant health outcomes

Diversity of Cl− Channels

Cl− channels are widely found anion pores that are regulated by a variety of signals and that play various roles. On the basis of molecular biologic findings, ligand-gated Cl− channels in synapses, cystic fibrosis transmembrane conductors (CFTRs) and ClC channel types have been established, followed by bestrophin and possibly by tweety, which encode Ca2+-activated Cl− channels. The ClC family has been shown to possess a variety of functions, including stabilization of membrane potential, excitation, cellvolume regulation, fluid transport, protein degradation in endosomal vesicles and possibly cell growth. The molecular structure of Cl− channel types varies from 1 to 12 transmembrane segments. By means of computer-based prediction, functional Cl− channels have been synthesized artificially, revealing that many possible ion pores are hidden in channel, transporter or unidentified hydrophobic membrane proteins. Thus, novel Cl−-conducting pores may be occasionally discovered, and evidence from molecular biologic studies will clarify their physiologic and pathophysiologic roles

Interventions to control myopia progression in children: protocol for an overview of systematic reviews and meta-analyses.

Background Myopia is a common visual disorder with increasing prevalence among developed countries of the world. Myopia constitutes a substantial risk factor for several ocular conditions that can lead to blindness. The purpose of this study is to conduct an overview of systematic reviews and meta-analyses in order to identify and appraise robust research evidence regarding the management of myopia progression in children and adolescents. Methods A literature search will be conducted in MEDLINE, EMBASE, The Cochrane Database of Systematic Reviews (CDSR), Database of Abstracts of Reviews of Effects (DARE), and Health Technology Assessment (HTA) Database via Centre for Reviews and Dissemination (CRD). We will search for systematic reviews or meta-analyses that examine optical or pharmaceutical modalities for myopia control. Two independent overview authors will screen the titles and abstracts against the eligibility criteria. Individual study’s methodological quality and quality of evidence for each outcome of interest will be assessed by two independent authors using the ROBIS tool and GRADE rating, respectively. In cases of disagreement, consensus will be reached with the help of a third author. Our primary outcomes will be the mean change in refractive error, mean axial length change, and adverse events. A citation matrix will be generated, and the corrected covered area (CCA) will be estimated, in order to identify overlapping primary studies. Possible meta-biases and measures of heterogeneity will be described, and cases of dual co-authorship will be identified and discussed. If any recently published randomized controlled trials (RCTs) are detected, these will be appraised and their findings will be presented. An overall summary of outcomes will be provided using descriptive statistics and will be supplemented by narrative synthesis. Discussion This overview will examine the high level of existing evidence for treatment of myopia progression. Efficient interventions will be identified, and side effects will be reported. The expected benefit is that all robust recent research evidence will be compiled in a single study. The results may inform future research in this area, which should provide insight into the appropriate regimes for the administration of these modalities and contribute to future guideline development

Physiology and pathophysiology of the vasopressin-regulated renal water reabsorption

To prevent dehydration, terrestrial animals and humans have developed a sensitive and versatile system to maintain their water homeostasis. In states of hypernatremia or hypovolemia, the antidiuretic hormone vasopressin (AVP) is released from the pituitary and binds its type-2 receptor in renal principal cells. This triggers an intracellular cAMP signaling cascade, which phosphorylates aquaporin-2 (AQP2) and targets the channel to the apical plasma membrane. Driven by an osmotic gradient, pro-urinary water then passes the membrane through AQP2 and leaves the cell on the basolateral side via AQP3 and AQP4 water channels. When water homeostasis is restored, AVP levels decline, and AQP2 is internalized from the plasma membrane, leaving the plasma membrane watertight again. The action of AVP is counterbalanced by several hormones like prostaglandin E2, bradykinin, dopamine, endothelin-1, acetylcholine, epidermal growth factor, and purines. Moreover, AQP2 is strongly involved in the pathophysiology of disorders characterized by renal concentrating defects, as well as conditions associated with severe water retention. This review focuses on our recent increase in understanding of the molecular mechanisms underlying AVP-regulated renal water transport in both health and disease

ClC-1 chloride channel: Matching its properties to a role in skeletal muscle

The definitive version is available at www.blackwell-synergy.com1. ClC-1 is a Cl- channel in mammalian skeletal muscle that plays an important role in membrane repolarization following muscular contraction. Reduction of ClC-1 conductance results in myotonia, a state characterized by muscle hyperexcitability. 2. As is the case for other members of the ClC family, ClC-1 exists as a dimer that forms a double-barrelled channel. Each barrel, or pore, of ClC-1 is gated by its own gate ('fast' or 'single pore' gate), whereas both pores are gated simultaneously by another mechanism ('slow' or 'common' gate). 3. Comparison of the biophysical and pharmacological properties of heterologously expressed ClC-1 with the properties of the Cl- conductance measured in skeletal muscle strongly suggests that ClC-1 is the major Cl- channel responsible for muscle repolarization. However, not all results obtained in experiments on whole muscle or muscle fibres support this notion. 4. In the present review we attempt to bring together the current knowledge of ClC-1 with the physiology of skeletal muscle.Edoardo C Aromataris and Grigori Y Rychko

Effectiveness of mealtime interventions to improved nutritional intake of adult patients in the acute care setting: a systematic review

Background Malnutrition affects 20-50% of patients in acute care hospitals. It is a problem that often goes unrecognized and untreated despite being associated with a number of adverse health consequences including delayed wound healing, increased infection rates, functional decline, increased length of stay in hospital and increased mortality. Lack of mealtime assistance has been suggested as a possible barrier to adequate nutritional intake in patients. Mealtime intervention strategies focusing on either the mealtime environment or on the provision of support have been promoted by various organisations and advocacy groups as a means to improve nutritional intake. Objectives The objective of this systematic review was to identify, assess and synthesize the available evidence on the effectiveness of mealtime interventions to improve nutritional intake of adult patients in the acute care setting. Inclusion criteria Types of participants Adults and/or elderly, aged 18 years and over, from any ethnic background, who were inpatients in acute care hospital with any diagnosis. Patients in intensive care or high dependency units, those obtaining their nutrition exclusively by enteral or parenteral means, those receiving palliative care or considered to be at end of life were excluded. Types of intervention(s)/phenomena of interest Any supportive mealtime practices that promote optimal eating and feeding for adult patients in the acute care setting that are not solely related to the actual food or fluid offered or ordered, for or by the patient. Types of studies Randomized controlled trials and quasi-experimental studies. Types of outcomes The primary outcome measures of interest were measures of nutritional intake namely energy and protein and/or nutritional status, length of stay in hospital and all-cause mortality. Search strategy A three step search strategy was used to find published and unpublished studies reported in English language. Methodological quality Studies that met the review inclusion criteria were critically appraised by two reviewers for methodological validity using the Joanna Briggs Institute Meta Analysis Statistics Assessment and Review Instrument (JBI-MAStARI). Data collection Data was extracted from the included studies by the primary reviewer using JBI-MAStARI data extraction tool. The tool included specific details about the interventions, population, study methods and outcome measures of relevance to the systematic review question. Data synthesis Heterogeneity in study designs, interventions, outcomes and reporting meant meta-analysis was not possible. The findings were therefore presented as a narrative summary. Results Six included studies involving 1071 patients evaluated the effectiveness of employed assistants, trained volunteers and eating at a table or in a dining room rather than by the bedside or in bed. Patient energy intake increased when employed assistants provided mealtime assistance, however this was only statistically significant for one of the two studies that investigated this mealtime intervention. Similarly, energy intake increased when trained volunteers supported patients at mealtimes; however this was only statistically significant in one of two relevant studies. Protein intake significantly increased in two studies where trained volunteers provided assistance at mealtimes. One study reported that energy intake significantly increased when patients ate at a table and another when patients ate in a dining room as compared with eating beside or in their beds. Conclusions Mealtime interventions including the use of assistants, trained volunteers and eating at a table or in a dining room increased the energy intake of patients in acute care hospitals. Mealtime assistance provided by trained volunteers also increased protein intake in this patient group. Few studies were TRUNCATED AT 600 WORDSGail Whitelock, Edoardo Aromatari