Search results for "DAS"
showing 10 items of 4164 documents
Hemocyanin conformational changes associated with SDS-induced phenol oxidase activation.
2007
The enzymatic activity of phenoloxidase is assayed routinely in the presence of SDS. Similar assay conditions elicit phenoloxidase activity in another type 3 copper protein, namely hemocyanin, which normally functions as an oxygen carrier. The nature of the conformational changes induced in type 3 copper proteins by the denaturant SDS is unknown. This comparative study demonstrates that arthropod hemocyanins can be converted from being an oxygen carrier to a form which exhibits phenoloxidase activity by incubation with SDS, with accompanying changes in secondary and tertiary structure. Structural characterisation, using various biophysical methods, suggests that the micellar form of SDS is …
Instructor Presence in a Virtual Classroom
2021
Abstract Synchronous online learning platforms have been used actively during the COVID-19 period. They have opened possibilities for online learning and interaction, but have also posed new challenges for instructors. This article provides insights into one teacher’s interactions and examines how the instructor presence is expressed in the teachers’ activities in virtual classrooms in higher education. Instructor presence is investigated using the social and teaching presence indicators of the community of inquiry (CoI) framework. Twelve hours of interactions across six online classes were recorded, transcribed, and analysed using content analysis. The findings suggest that indicators of t…
Finite Sample Sizes of the GRS Test in the Presence of Dynamic Correlation and Conditional Heteroskedasticity
2017
This paper investigates the finite sample properties of the widely-used Gibbons, Ross, Shanken (1989) (GRS) test in the presence of both conditional correlation and conditional heteroskedasticity. It finds that the GRS test exhibits serious size distortions resulting in potentially misleading statistical inferences. The correct critical values, as reported in the study, are considerably larger than suggested by the GRS test.
El estimable logro de un diletante. Sangre y arena (Vicente Blasco Ibáñez y Max André, 1916)
2018
La adaptación de la novela Sangre y arena llevada al cine por Blasco Ibáñez y Max André posee unos rasgos expresivos y temáticos que la convierten en un filme fundacional e inspirador para el cine posterior. El novelista planeó su producción como un ejercicio para lograr la expresividad artística y la exposición verosímil y fiable de los usos socioculturales españoles implícitos en la ficción, con el objeto de contrarrestar las españoladas al uso. Movido por tal empeño, se implicó de lleno en la adaptación de la película de la que llegó a ser productor, guionista y codirector, lo que implica que ejerció un férreo control de todo el proceso de su producción. Partiendo de esa circunstancia, l…
Integrismo político en EEUU / 2. Integrismo y tortura
2004
Data from: Cuticular hydrocarbons as potential mediators of cryptic species divergence in a mutualistic ant association
2019
Upon advances in sequencing techniques, more and more morphologically identical organisms are identified as cryptic species. Often, mutualistic interactions are proposed as drivers of diversification. Species of the Neotropical parabiotic ant association between Crematogaster levior and Camponotus femoratus are known for highly diverse cuticular hydrocarbon (CHC) profiles, which in insects serve as desiccation barrier but also as communication cues. In the present study we investigated the association of the ants’ CHC profiles to genotypes and morphological traits, and discovered cryptic species pairs in both genera. To assess putative niche differentiation between the cryptic species, we c…
Smoking trends among adolescents from 1990 to 2002 in ten European countries and Canada.
2006
Abstract Background Daily smoking adolescents are a public health problem as they are more likely to become adult smokers and to develop smoking-related health problems later on in their lives. Methods The study is part of the four-yearly, cross-national Health Behaviour in School-aged Children study, a school-based survey on a nationally representative sample using a standardised methodology. Data of 4 survey periods are available (1990–2002). Gender-specific daily smoking trends among 14–15 year olds are examined using logistic regressions. Sex ratios are calculated for each survey period and country. Interaction effects between period and gender are examined. Results Daily smoking preval…
Consequências mal adaptativas de invasões mentais com conteúdos relacionados a transtornos obsessivos, dismórficos, hipocondríacos e alimentares: dif…
2021
Unwanted mental intrusions (UMIs) with contents related to Obsessive-Compulsive Disorder (OCD), Body Dysmorphic Disorder (BDD), Illness Anxiety Disorder (IAD), and Eating Disorders (EDs) are highly prevalent, independently of the cultural and/or social context. Cognitive-behavioral explanations for these disorders postulates that the escalation from common UMIs to clinically relevant symptoms depends on the maladaptive consequences (i.e., emotions, appraisals, and control strategies) of experiencing UMIs. This study examines, from a cross-cultural perspective, the cognitive-behavioral postulates of the maladaptive consequences of having UMIs.Non-clinical 1,473 participants from Europe, the …
Structure of mammalian plasma fetuin-B and its mechanism of selective metallopeptidase inhibition
2018
The co-crystal structure of the metallopeptidase astacin with its specific protein inhibitor fetuin-B reveals a novel mechanism of inhibition.