110 research outputs found

    L-band briefcase terminal network operation

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    During 1989, SkyWave Electronics Ltd. developed a lightweight battery powered, L Band Briefcase Satellite Terminal (LBT) which is capable of providing truly portable voice and data communications on a global scale. The LBT is designed to operate through Inmarsat's Atlantic Region Satellite MARECSB-2, and Teleglobe Canada's 18 meter Laurentides Earth Station. A small operating network, consisting of up to 20 mobile terminals and homing on the Laurentides Earth Station, was set up in the spring of 1990 to provide commercial service to LBT users, both domestic and international. This paper describes the LBT and the operation of the network

    Do trauma cue exposure and/or PTSD symptom severity intensify selective approach bias toward cannabis cues in regular cannabis users with trauma histories?

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    Trauma cue-elicited activation of automatic cannabis-related cognitive biases are theorized to contribute to comorbid posttraumatic stress disorder and cannabis use disorder. This phenomenon can be studied experimentally by combining the trauma cue reactivity paradigm (CRP) with cannabis-related cognitive processing tasks. In this study, we used a computerized cannabis approach-avoidance task (AAT) to assess automatic cannabis (vs. neutral) approach bias following personalized trauma (vs. neutral) CRP exposure. We hypothesized that selective cannabis (vs. neutral) approach biases on the AAT would be larger among participants with higher PTSD symptom severity, particularly following trauma (vs. neutral) cue exposure. We used a within-subjects experimental design with a continuous between-subjects moderator (PTSD symptom severity). Participants were exposed to both a trauma and neutral CRP in random order, completing a cannabis AAT (cannabis vs. neutral stimuli) following each cue exposure. Current cannabis users with histories of psychological trauma (n = 50; 34% male; mean age = 37.8 years) described their most traumatic lifetime event, and a similarly-detailed neutral event, according to an established interview protocol that served as the CRP. As hypothesized, an AAT stimulus type x PTSD symptom severity interaction emerged (p = .042) with approach bias greater to cannabis than neutral stimuli for participants with higher (p = .006), but not lower (p = .36), PTSD symptom severity. Contrasting expectations, the stimulus type x PTSD symptoms effect was not intensified by trauma cue exposure (p = .19). Selective cannabis approach bias may be chronically activated in cannabis users with higher PTSD symptom severity and may serve as an automatic cognitive mechanism to help explain PTSD-CUD co-morbidity.</p

    Digital transformations and the archival nature of surrogates

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    Large-scale digitization is generating extraordinary collections of visual and textual surrogates, potentially endowed with transcendent long-term cultural and research values. Understanding the nature of digital surrogacy is a substantial intellectual opportunity for archival science and the digital humanities, because of the increasing independence of surrogate collections from their archival sources. The paper presents an argument that one of the most significant requirements for the long-term access to collections of digital surrogates is to treat digital surrogates as archival records that embody traces of their fluid lifecycles and therefore are worthy of management and preservation as archives. It advances a theory of the archival nature of surrogacy founded on longstanding notions of archival quality, the traces of their source and the conditions of their creation, and the functional ‘‘work of the archive.’’ The paper presents evidence supporting a ‘‘secondary provenance’’ derived from re-digitization, re-ingestion of multiple versions, and de facto replacement of the original sources. The design of the underlying research that motivates the paper and summary findings are reported separately. The research has been supported generously by the US Institute of Museum and Library Services.Institute for Museum and Library ServicesPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111825/1/J26 Conway Digital Transformations 2014-pers.pdfDescription of J26 Conway Digital Transformations 2014-pers.pdf : Main articl

    Well-being in residency training: a survey examining resident physician satisfaction both within and outside of residency training and mental health in Alberta

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    BACKGROUND: Despite the critical importance of well-being during residency training, only a few Canadian studies have examined stress in residency and none have examined well-being resources. No recent studies have reported any significant concerns with respect to perceived stress levels in residency. We investigated the level of perceived stress, mental health and understanding and need for well-being resources among resident physicians in training programs in Alberta, Canada. METHODS: A mail questionnaire was distributed to the entire resident membership of PARA during 2003 academic year. PARA represents each of the two medical schools in the province of Alberta. RESULTS: In total 415 (51 %) residents participated in the study. Thirty-four percent of residents who responded to the survey reported their life as being stressful. Females reported stress more frequently than males (40% vs. 27%, p < 0.02). Time pressure was reported as the number one factor contributing to stress (44% of males and 57% of females). A considerable proportion of residents would change their specialty program (14%) and even more would not pursue medicine (22%) if given the opportunity to relive their career. Up to 55% of residents reported experiencing intimidation and harassment. Intimidation and harassment was strongly related to gender (12% of males and 38% of females). Many residents (17%) rated their mental health as fair or poor. This was more than double the amount reported in the Canadian Community Health Survey from the province (8%) or the country (7%). Residents highly valued their colleagues (67%), program directors (60%) and external psychiatrist/psychologist (49%) as well-being resources. Over one third of residents wished to have a career counselor (39%) and financial counselor (38%). CONCLUSION: Many Albertan residents experience significant stressors and emotional and mental health problems. Some of which differ among genders. This study can serve as a basis for future resource application, research and advocacy for overall improvements to well-being during residency training

    Thought Problems from Adolescence to Adulthood: Measurement Invariance and Longitudinal Heritability

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    This study investigates the longitudinal heritability in Thought Problems (TP) as measured with ten items from the Adult Self Report (ASR). There were ~9,000 twins, ~2,000 siblings and ~3,000 additional family members who participated in the study and who are registered at the Netherlands Twin Register. First an exploratory factor analysis was conducted to examine the underlying factor structure of the TP-scale. Then the TP-scale was tested for measurement invariance (MI) across age and sex. Next, genetic and environmental influences were modeled on the longitudinal development of TP across three age groups (12–18, 19–27 and 28–59 year olds) based on the twin and sibling relationships in the data. An exploratory factor analysis yielded a one-factor solution, and MI analyses indicated that the same TP-construct is assessed across age and sex. Two additive genetic components influenced TP across age: the first influencing TP throughout all age groups, while the second arises during young adulthood and stays significant throughout adulthood. The additive genetic components explained 37% of the variation across all age groups. The remaining variance (63%) was explained by unique environmental influences. The longitudinal phenotypic correlation between these age groups was entirely explained by the additive genetic components. We conclude that the TP-scale measures a single underlying construct across sex and different ages. These symptoms are significantly influenced by additive genetic factors from adolescence to late adulthood

    Feasibility and marketing studies of health sciences librarianship education programs.

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    The University of North Carolina at Chapel Hill evaluated five curricular models designed to improve education for health sciences librarianship. Three of the models enhanced existing degree and certificate programs, and two were new programs for working information professionals. Models were developed with input from experts and a Delphi study; the marketability of the models was tested through surveys of potential students and employers; and recommendations were made as a guide to implementation. The results demonstrated a demand for more specialized curricula and for retraining opportunities. Marketing data showed a strong interest from potential students in a specialized master's degree, and mid-career professionals indicated an interest in post-master's programs that provided the ability to maintain employment. The study pointed to the opportunity for a center of excellence in health sciences information education to enable health sciences librarians to respond to their evolving roles

    Prefrontal Cortex Glutamate Correlates with Mental Perspective-Taking

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    Background: Dysfunctions in theory of mind and empathic abilities have been suggested as core symptoms in major psychiatric disorders including schizophrenia and autism. Since self monitoring, perspective taking and empathy have been linked to prefrontal (PFC) and anterior cingulate cortex (ACC) function, neurotransmitter variations in these areas may account for normal and pathological variations of these functions. Converging evidence indicates an essential role of glutamatergic neurotransmission in psychiatric diseases with pronounced deficits in empathy. However, the role of the glutamate system for different dimensions of empathy has not been investigated so far. Methodology/Principal Findings: Absolute concentrations of cerebral glutamate in the ACC, left dorsolateral PFC and left hippocampus were determined by 3-tesla proton magnetic resonance spectroscopy (1H-MRS) in 17 healthy individuals. Three dimensions of empathy were estimated by a self-rating questionnaire, the Interpersonal Reactivity Index (IRI). Linear regression analysis showed that dorsolateral PFC glutamate concentration was predicted by IRI factor ‘‘perspective taking’’ (T = 22.710, p = 0.018; adjusted alpha-level of 0.017, Bonferroni) but not by ‘‘empathic concern’ ’ or ‘‘personal distress’’. No significant relationship between IRI subscores and the glutamate levels in the ACC or left hippocampus was detected. Conclusions/Significance: This is the first study to investigate the role of the glutamate system for dimensions of theory of mind and empathy. Results are in line with recent concepts that executive top-down control of behavior is mediated b

    Higher levels of glutamate in the associative-striatum of subjects with prodromal symptoms of schizophrenia and patients with first-episode psychosis

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    The glutamatergic and dopaminergic systems are thought to be involved in the pathophysiology of schizophrenia. Their interaction has been widely documented and may have a role in the neurobiological basis of the disease. The aim of this study was to compare, using proton magnetic resonance spectroscopy (1H-MRS), glutamate levels in the precommissural dorsal-caudate (a dopamine-rich region) and the cerebellar cortex (negligible for dopamine) in the following: (1) 18 antipsychotic-naïve subjects with prodromal symptoms and considered to be at ultra high-risk for schizophrenia (UHR), (2) 18 antipsychotic-naïve first- episode psychosis patients (FEP), and (3) 40 age- and sex- matched healthy controls. All subjects underwent a 1H-MRS study using a 3Tesla scanner. Glutamate levels were quantified and corrected for the proportion of cerebrospinal fluid and percentage of gray matter in the voxel. The UHR and FEP groups showed higher levels of glutamate than controls, without differences between UHR and FEP. In the cerebellum, no differences were seen between the three groups. The higher glutamate level in the precommissural dorsal-caudate and not in the cerebellum of UHR and FEP suggests that a high glutamate level (a) precedes the onset of schizophrenia, and (b) is present in a dopamine-rich region previously implicated in the pathophysiology of schizophrenia.peer-reviewe
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