355 research outputs found
Experimental confirmation of cyclic thermal joint conductance
Heat transfer from tungsten and iron specimens confirming model of elasto-plastic events in cyclic engagement of loaded range surface
Instructional Uses of Instant Messaging (IM) During Classroom Lectures
Can “Information Age” learners effectively multi-task in the classroom? Can synchronous classroom activities be designed around conceptually related tasks, to encourage deeper processing and greater learning of classroom content? This research was undertaken to begin to address these questions. In this study, we explored the use of instructionally-related instant messaging (IM) discussions during undergraduate university lectures. Over the course of three weeks, students practiced with and then employed hand-held computers for brief, synchronous class discussions in response to assigned questions related to the lectures. Students were observed during these sessions, and students and the instructors were interviewed separately afterwards. The contents of students’ discussions indicate that they were capable of engaging in on-task discussions and of expressing opinions and exploring instructionally relevant topics. However, even though students routinely multi-task in classrooms as they attend to lectures, process the contents, and record notes for later study, both students and the instructors expressed some discomfort with discussion occurring synchronously with classroom lectures. In this paper, we describe student discussion behavior, and reflect on possible applications of multiple sequential (rather than simultaneous) tasks during classroom instruction
Rapid Assessment of Octocoral Diversity and Habitat on Saba Bank, Netherlands Antilles
Saba Bank is a large submerged platform (∼2200 km2), average depth 30 m, located 4 km southwest of Saba Island in Netherlands Antilles, Caribbean Sea. Ships traveling to and from oil terminals on nearby St. Eustatius routinely anchor on the Bank, damaging benthic megafauna. Gorgonian octocorals are vulnerable to anchor damage, and they are common and conspicuous in shallow water (15–50 m) around the banks. This prompted a rapid assessment of octocoral habitat and diversity. The primary objectives were to estimate total species richness and to characterize habitats vis a vis gorgonians. Landsat imagery and multibeam bathymetry were employed to identify random sites for quantitative transects. A Seabotix LBV200L remotely operated vehicle (ROV) and SCUBA were used to collect and survey to 130 m. A total of 14 scuba dives and 3 ROV dives were completed in 10 days. During that time, 48 octocoral species were collected, including two likely undescribed species in the genera Pterogorgia and Lytreia. Gorgonian richness was exceptional, but not all species were collected, because the species accumulation curve remained steeply inclined after all surveys. Two shallow-water gorgonian habitat types were identified using multidimensional scaling and hierarchical cluster analyses: 1) a high diversity, high density fore-reef environment characterized by Eunicea spp., Gorgonia spp., and Pseudopterogorgia spp. and 2) a low diversity, low density plateau environment characterized by Pseudopterogorgia acerosa, Pterogorgia guadalupensis, and Gorgonia mariae. The analyses support hypotheses of broad (∼15 km) habitat homogeneity (ANOSIM, P>0.05), but a significant difference between fore-reef and plateau environments (ANOSIM, P<0.05). However, there was some indication of habitat heterogeneity along the 15 km study section of the 50 km platform edge along the southeast rim. Our results highlight the complexity and biodiversity of the Saba Bank, and emphasize the need for more scientific exploration
Schizophrenia and psychotic symptoms in families of two American Indian tribes
Abstract Background The risk of schizophrenia is thought to be higher in population isolates that have recently been exposed to major and accelerated cultural change, accompanied by ensuing socio-environmental stressors/triggers, than in dominant, mainstream societies. We investigated the prevalence and phenomenology of schizophrenia in 329 females and 253 males of a Southwestern American Indian tribe, and in 194 females and 137 males of a Plains American Indian tribe. These tribal groups were evaluated as part of a broader program of gene-environment investigations of alcoholism and other psychiatric disorders. Methods Semi-structured psychiatric interviews were conducted to allow diagnoses utilizing standardized psychiatric diagnostic criteria, and to limit cultural biases. Study participants were recruited from the community on the basis of membership in pedigrees, and not by convenience. After independent raters evaluated the interviews blindly, DSM-III-R diagnoses were assigned by a consensus of experts well-versed in the local cultures. Results Five of the 582 Southwestern American Indian respondents (prevalence = 8.6 per 1000), and one of the 331 interviewed Plains American Indians (prevalence = 3.02 per 1000) had a lifetime diagnosis of schizophrenia. The lifetime prevalence rates of schizophrenia within these two distinct American Indian tribal groups is consistent with lifetime expectancy rates reported for the general United States population and most isolate and homogeneous populations for which prevalence rates of schizophrenia are available. While we were unable to factor in the potential modifying effect that mortality rates of schizophrenia-suffering tribal members may have had on the overall tribal rates, the incidence of schizophrenia among the living was well within the normative range. Conclusion The occurrence of schizophrenia among members of these two tribal population groups is consistent with prevalence rates reported for population isolates and in the general population. Vulnerabilities to early onset alcohol and drug use disorders do not lend convincing support to a diathesis-stressor model with these stressors, commonly reported with these tribes. Nearly one-fifth of the respondents reported experiencing psychotic-like symptoms, reaffirming the need to examine sociocultural factors actively before making positive diagnoses of psychosis or schizophrenia.</p
The importance of the concepts of disaster, catastrophe, violence, trauma and barbarism in defining posttraumatic stress disorder in clinical practice
<p>Abstract</p> <p>Background</p> <p>Several terms in the scientific literature about posttraumatic stress disorder are used with different meanings in studies conducted by different authors. Words such as <it>trauma, violence, catastrophe, disaster </it>and <it>barbarism </it>are often used vaguely or confusingly, and their meanings change in different articles. The lack of conceptual references for these expressions complicates the organization of literature. Furthermore, the absence of clear concepts may be an obstacle to clinical treatment because the use of these words by the patients does not necessarily point to a diagnosis of posttraumatic stress disorder.</p> <p>Discussion</p> <p>A critical review of scientific literature showed that stress can be divided in stages to facilitate specific terminological adjustments to the event itself, to the subject-event interaction and to psychological responses. Moreover, it demonstrated that the varying concept of trauma expands into fundamental psychotherapeutic definitions and that the meanings of violence associated with barbarism are an obstacle to resilience. Therefore, this study updates the etymological origins and applications of these words, connects them to the expansions of meanings that can be operated in the clinical care of patients with posttraumatic stress disorder, and analyzes them critically according to the criterion A of DSM-IV and ICD-10.</p> <p>Summary</p> <p>The terminology in the literature about posttraumatic stress disorder includes a plethora of terms whose meanings are not fully understood, and that, therefore, limit this terminology. The analysis of these terms suggested that the transformation of the concept of <it>trauma </it>led to a broader understanding of this phenomenon in its psychic dimensions, that a barbarian type of violence constitutes an obstacle to resilience, and that the criterion A of the DSM-IV and ICD-10 shows imprecision and conceptual fragilities.</p> <p>Methods</p> <p>To develop this debate article, a current specialized literature review was achieved by searching and retrieving the key terms from two major databases: PubMed and PsycINFO. The key terms included "disaster", "catastrophe", "barbarism", "terrorism", "trauma", "psychic trauma" and "violence", also in combination with the terms "PTSD", "concept" and "conceptual aspects". The data were captured specially from review articles. The included studies were those mostly identified by the authors as relevant by the presence of a <it>conceptual approach </it>in any part of the paper. Researches that relied solely on empirical indicators, like psychopathological, neurobiological or pharmacological aspects, were excluded. The focus here was in conceptual aspects, even when some few empirical studies were included.</p> <p>As it was noted a paucity of medical references related to conceptual aspects of these terms, a wider literature needed to be included, including chapters, books and articles proceeded from the Humanities areas. "Interdisciplinary research is needed in this area to include perspectives from a range of different disciplines" once that "to promote public health (...) new dimensions of such interactions and the implications thereof should be pursued in collaboration with researchers from broader areas" <abbrgrp><abbr bid="B1">1</abbr></abbrgrp>.</p
It is time to talk about people: a human-centered healthcare system
Examining vulnerabilities within our current healthcare system we propose borrowing two tools from the fields of engineering and design: a) Reason's system approach [1] and b) User-centered design [2,3]. Both approaches are human-centered in that they consider common patterns of human behavior when analyzing systems to identify problems and generate solutions. This paper examines these two human-centered approaches in the context of healthcare. We argue that maintaining a human-centered orientation in clinical care, research, training, and governance is critical to the evolution of an effective and sustainable healthcare system
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