Integrated optical directional coupler biosensor

We present measurements on biomolecular binding reactions, using a new type of integrated optical biosensor based on a planar directional coupler structure. The device is fabricated by Ag+-Na+ ion-exchange in glass and definition of the sensing region is achieved by use of transparent fluoropolymer isolation layers formed by thermal evaporation. The suitability of the sensor for application to the detection of environmental pollutants is considered

Some Aspects of the Photoelectrochemical Effect at the Mercury - Aqueous Solution Interphase

The emissive properties of a polarized mercury surface in contact. with aqueous solutions of electron acceptors is discussed. The proportionality between photocurrent and light intensity is experimentally verified; the origin of the residual current is discussed, and the potentialities of a photoelectrochemical method of study· of the properties of intermediates and radicals is illustrated for carbon dioxide

Analytic frameworks for assessing dialogic argumentation in online learning environments

Over the last decade, researchers have developed sophisticated online learning environments to support students engaging in argumentation. This review first considers the range of functionalities incorporated within these online environments. The review then presents five categories of analytic frameworks focusing on (1) formal argumentation structure, (2) normative quality, (3) nature and function of contributions within the dialog, (4) epistemic nature of reasoning, and (5) patterns and trajectories of participant interaction. Example analytic frameworks from each category are presented in detail rich enough to illustrate their nature and structure. This rich detail is intended to facilitate researchers’ identification of possible frameworks to draw upon in developing or adopting analytic methods for their own work. Each framework is applied to a shared segment of student dialog to facilitate this illustration and comparison process. Synthetic discussions of each category consider the frameworks in light of the underlying theoretical perspectives on argumentation, pedagogical goals, and online environmental structures. Ultimately the review underscores the diversity of perspectives represented in this research, the importance of clearly specifying theoretical and environmental commitments throughout the process of developing or adopting an analytic framework, and the role of analytic frameworks in the future development of online learning environments for argumentation

Literary ethnography of evidence-based healthcare : accessing the emotions of rational-technical discourse

In this article I revisit the idea of literary ethnography (proposed by Van de Poel-Knottnerus and Knottnerus, 1994) as a method for investigating social phenomena constituted principally through literature. I report the use of this method to investigate the topic of evidence-based healthcare, EBHC. EBHC is a field of discourse much built upon a dichotomy between rationality and emotionality. In this context literary ethnography, a particular type of discourse analysis, is valuable for allowing researchers to bring the emotional currents of technical-rational discourse into conscious awareness. In such discourses, emotions are not written out by name. The researcher must discern emotional phenomena by experiencing the discourse, and (try to) bring them into intelligible expression. As I clarify this process I develop Van de Poel-Knottnerus and Knottnerus’ method theoretically, look to destabilise the rationalityemotionality dichotomy foundational to discourse around EBHC, and so transgress its conventional lines of thought.PostprintPeer reviewe

Risk factors for metabolic syndrome independently predict arterial stiffness and endothelial dysfunction in patients with chronic kidney disease and minimal comorbidity

OBJECTIVE: Metabolic syndrome (MS) is common in patients with chronic kidney disease (CKD), but its contribution to arterial stiffness and endothelial dysfunction in CKD is not well defined. We hypothesized that risk factors for MS would independently predict arterial stiffness and endothelial dysfunction in CKD patients. RESEARCH DESIGN AND METHODS: Risk factors for MS, carotid-femoral pulse wave velocity (CF-PWV) and flow-mediated dilation (FMD) as measures of arterial stiffness and endothelial dysfunction, respectively, were assessed in 113 minimally comorbid CKD patients and in 23 matched control subjects. RESULTS: CF-PWV correlated with systolic blood pressure (SBP), waist circumference, and plasma glucose (r(2) = 0.25, 0.09, and 0.09; P < 0.01 for all). FMD correlated with SBP (r(2) = 0.09; P < 0.01) and waist circumference (r(2) = 0.03; P < 0.05). CF-PWV increased progressively (r(2) = 0.07; P < 0.01) with increasing number of risk factors for MS. In multiple linear regression, SBP and waist circumference were independent determinants of CF-PWV, whereas only SBP predicted FMD. CONCLUSIONS: The number of MS risk factors is an important determinant of arterial stiffness in CKD patients irrespective of the degree of renal impairment. Although BP remains the major determinant of arterial stiffness and endothelial dysfunction, waist circumference independently predicts arterial stiffness. MS risk factors, particularly abdominal girth, are potential targets for future interventional studies in patients with CKD

Impaired flow-induced arterial remodeling in DOCA-salt hypertensive rats

Arteries from young healthy animals respond to chronic changes in blood flow and blood pressure by structural remodeling. We tested whether the ability to respond to decreased (-90%) or increased (+100%) blood flow is impaired during the development of deoxycorticosterone acetate (DOCA)-salt hypertension in rats, a model for an upregulated endothelin-1 system. Mesenteric small arteries (MrA) were exposed to low blood flow (LF) or high blood flow (HF) for 4 or 7 weeks. The bioavailability of vasoactive peptides was modified by chronic treatment of the rats with the dual neutral endopeptidase (NEP)/endothelin-converting enzyme (ECE) inhibitor SOL1. After 3 or 6 weeks of hypertension, the MrA showed hypertrophic arterial remodeling (3 weeks: media cross-sectional area (mCSA): 10 +/- 1 x 10(3) to 17 +/- 2 x 10(3) mu m(2); 6 weeks: 13 +/- 2 x 10(3) to 24 +/- 3 x 10(3) mu m(2)). After 3, but not 6, weeks of hypertension, the arterial diameter was increased (empty set: 385 +/- 13 to 463 +/- 14 mu m). SOL1 reduced hypertrophy after 3 weeks of hypertension (mCSA: 6 x 10(3) +/- 1 x 10(3) mu m(2)). The diameter of the HF arteries of normotensive rats increased (empty set: 463 +/- 22 mu m) but no expansion occurred in the HF arteries of hypertensive rats (empty set: 471 +/- 16 mu m). MrA from SOL1-treated hypertensive rats did show a significant diameter increase (empty set: 419 +/- 13 to 475 +/- 16 mu m). Arteries exposed to LF showed inward remodeling in normotensive and hypertensive rats (mean empty set between 235 and 290 mu m), and infiltration of monocyte/ macrophages. SOL1 treatment did not affect the arterial diameter of LF arteries but reduced the infiltration of monocyte/ macrophages. We show for the first time that flow-induced remodeling is impaired during the development of DOCA-salt hypertension and that this can be prevented by chronic NEP/ECE inhibition. Hypertension Research (2012) 35, 1093-1101; doi:10.1038/hr.2012.94; published online 12 July 201

Stressed and Happy? Investigating the Research between Happiness and Perceived Stress

Developing interventions to increase happiness is a major focus of the emerging field of positive psychology. Common beliefs about the need to reduce stress to obtain happiness suggest that stress management activities should be included in these interventions. However, the research on the relationship between positive and negative affect is equivocal. Theoretically, they are conceptualized as independent dimensions, but research has often found an inverse relationship between happiness and stress. In addition,the research generally attempts to assess stress objectively rather than in terms of the cognitive appraisal process. The current study examines the relationship between perceived stress and happiness among 100 college students to determine if the same inverse relationship exists. Linear correlations between happiness and perceived stress were significant indicating that there was an inverse relationship between these variables. The discussion focuses on several factors that might help to explain the observed relationship

An introduction to video methods in organizational research

Video has become a methodological tool of choice for many researchers in social science, but video methods are relatively new to the field of organization studies. This article is an introduction to video methods. First, we situate video methods relative to other kinds of research, suggesting that video recordings and analyses can be used to replace or supplement other approaches, not only observational studies but also retrospective methods such as interviews and surveys. Second, we describe and discuss various features of video data in relation to ontological assumptions that researchers may bring to their research design. Video involves both opportunities and pitfalls for researchers, who ought to use video methods in ways that are consistent with their assumptions about the world and human activity. Third, we take a critical look at video methods by reporting progress that has been made while acknowledging gaps and work that remains to be done. Our critical considerations point repeatedly at articles in this special issue, which represent recent and important advances in video method

Communicative competence and institutional affiliation: interactional processes of identity construction by immigrant students in Catalonia

The growing presence of children of immigrant families in the public school system in the bilingual region of Catalonia provides us with an opportunity to study how young multilingual and multicultural speakers construct their social competencies and their identity within the specific context of a gate-keeping social institution such as the school. The study reported in this paper approaches language learning as a process of socialisation that involves not only learning how to make sense of linguistic signs but also learning how to enact different social roles in particular institutions. The analysis focuses on the interactional profiles of two immigrant students in two types of communicative activities that are representative of the school context: responding to questions from an adult and cooperating with a peer in the resolution of a learning task. By shifting the focus of analysis from a decontextualised notion of communicative competence to the notion of 'institutionally affiliated communicative competence' and concentrating on issues such as the (1) the relationship between knowledge and participation, (2) language choice inside and outside school and (3) definitions of correctness in language use, the study reveals how the two students construct a highly 'affiliated' identit

‘Working with the media taught us a lot’: Understanding The Guardian’s Katine initiative

One of the more important ventures in the world of media and development over the past decade has been The Guardian newspaper’s ‘Katine’ project in Uganda. The newspaper, with funding from its readers and Barclays Bank, put more than 2.5 million pounds into a Ugandan sub-county over the course of 4 years. The project was profiled on a dedicated Guardian microsite, with regular updates in the printed edition of the newspaper. In this article, I look at the relationship that developed between journalists and the non-governmental organisation and show that the experience was both disorienting and reorienting for the development project that was being implemented. The scrutiny of the project that appeared on the microsite disoriented the non-governmental organisation, making its work the subject of public criticism. The particular issues explored by journalists also reoriented what the non-governmental organisation did on the ground. I also point to the ways the relationship grew more settled as the project moved along, suggesting the amount of work that sometimes goes into what is often characterised as the relatively uncritical relationship between journalists and non-governmental organisations