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1.
Adv Health Sci Educ Theory Pract ; 29(1): 173-198, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37347459

RESUMO

The goal of better medical student preparation for clinical practice drives curricular initiatives worldwide. Learning theory underpins Entrustable Professional Activities (EPAs) as a means of safe transition to independent practice. Regulators mandate senior assistantships to improve practice readiness. It is important to know whether meaningful EPAs occur in assistantships, and with what impact. Final year students at one UK medical school kept learning logs and audio-diaries for six one-week periods during a year-long assistantship. Further data were also obtained through interviewing participants when students and after three months as junior doctors. This was combined with data from new doctors from 17 other UK schools. Realist methods explored what worked for whom and why. 32 medical students and 70 junior doctors participated. All assistantship students reported engaging with EPAs but gaps in the types of EPAs undertaken exist, with level of entrustment and frequency of access depending on the context. Engagement is enhanced by integration into the team and shared understanding of what constitutes legitimate activities. Improving the shared understanding between student and supervisor of what constitutes important assistantship activity may result in an increase in the amount and/or quality of EPAs achieved.


Assuntos
Estudantes de Medicina , Humanos , Educação Baseada em Competências , Aprendizagem , Corpo Clínico Hospitalar , Competência Clínica , Reino Unido
2.
J Cogn Neurosci ; 33(7): 1381-1395, 2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-34496406

RESUMO

Studies have shown that transcranial direct current stimulation increases neuronal excitability of the targeted region and general connectivity of relevant functional networks. However, relatively little is understood of how the stimulation affects the connectivity relationship of the target with regions across the network structure of the brain. Here, we investigated the effects of transcranial direct current stimulation on the functional connectivity of the targeted region using resting-state fMRI scans of the human brain. Anodal direct current stimulation was applied to the left dorsolateral prefrontal cortex (lDLPFC; cathode on the right bicep), which belongs to the frontoparietal control network (FPCN) and is commonly targeted for neuromodulation of various cognitive functions including short-term memory, long-term memory, and cognitive control. lDLPFC's connectivity characteristics were quantified as graph theory measures, from the resting-state fMRI scans obtained prior to and following the stimulation. Critically, we tested pre- to poststimulation changes of the lDLPFC connectivity metrics following an active versus sham stimulation. We found that the stimulation had two distinct effects on the connectivity of lDLPFC: for Brodmann's area (BA) 9, it increased the functional connectivity between BA 9 and other nodes within the FPCN; for BA 46, net connectivity strength was not altered within FPCN, but connectivity distribution across networks (participation coefficient) was decreased. These findings provide insights that the behavioral changes as the functional consequences of stimulation may come about because of the increased role of lDLPFC in the FPCN.


Assuntos
Estimulação Transcraniana por Corrente Contínua , Encéfalo , Humanos , Imageamento por Ressonância Magnética , Memória de Curto Prazo , Córtex Pré-Frontal/diagnóstico por imagem
3.
Neural Plast ; 2018: 5769861, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30254668

RESUMO

The use of transcranial electrical stimulation (TES) as a method to augment neural activity has increased in popularity in the last decade and a half. The specific application of TES to the left prefrontal cortex has been shown to produce broad cognitive effects; however, the neural mechanisms underlying these effects remain unknown. In this work, we evaluated the effect of repetitive TES on cerebral perfusion. Stimulation was applied to the left prefrontal cortex on three consecutive days, and resting cerebral perfusion was quantified before and after stimulation using arterial spin labeling. Perfusion was found to decrease significantly more in a matched sham stimulation group than in a group receiving active stimulation across many areas of the brain. These changes were found to originate in the locus coeruleus and were broadly distributed in the neocortex. The changes in the neocortex may be a direct result of the stimulation or an indirect result via the changes in the noradrenergic system produced from the altered activity of the locus coeruleus. These findings indicate that anodal left prefrontal stimulation alters the activity of the locus coeruleus, and this altered activity may excite the noradrenergic system producing the broad behavioral effects that have been reported.


Assuntos
Encéfalo/diagnóstico por imagem , Encéfalo/fisiologia , Circulação Cerebrovascular/fisiologia , Descanso/fisiologia , Marcadores de Spin , Estimulação Transcraniana por Corrente Contínua/métodos , Adulto , Encéfalo/irrigação sanguínea , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Distribuição Aleatória , Adulto Jovem
4.
Brain Behav Immun ; 64: 152-161, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28427911

RESUMO

A commonly referenced transcranial Direct Current Stimulation (tDCS) safety threshold derives from tDCS lesion studies in the rat and relies on electrode current density (and related electrode charge density) to support clinical guidelines. Concerns about the role of polarity (e.g. anodal tDCS), sub-lesion threshold injury (e.g. neuroinflammatory processes), and role of electrode montage across rodent and human studies support further investigation into animal models of tDCS safety. Thirty-two anesthetized rats received anodal tDCS between 0 and 5mA for 60min through one of three epicranial electrode montages. Tissue damage was evaluated using hemotoxylin and eosin (H&E) staining, Iba-1 immunohistochemistry, and computational brain current density modeling. Brain lesion occurred after anodal tDCS at and above 0.5mA using a 25.0mm2 electrode (electrode current density: 20.0A/m2). Lesion initially occurred using smaller 10.6mm2 or 5.3mm2 electrodes at 0.25mA (23.5A/m2) and 0.5mA (94.2A/m2), respectively. Histological damage was correlated with computational brain current density predictions. Changes in microglial phenotype occurred in higher stimulation groups. Lesions were observed using anodal tDCS at an electrode current density of 20.0A/m2, which is below the previously reported safety threshold of 142.9A/m2 using cathodal tDCS. The lesion area is not simply predicted by electrode current density (and so not by charge density as duration was fixed); rather computational modeling suggests average brain current density as a better predictor for anodal tDCS. Nonetheless, under the assumption that rodent epicranial stimulation is a hypersensitive model, an electrode current density of 20.0A/m2 represents a conservative threshold for clinical tDCS, which typically uses an electrode current density of 2A/m2 when electrodes are placed on the skin (resulting in a lower brain current density).


Assuntos
Encéfalo/patologia , Estimulação Transcraniana por Corrente Contínua/efeitos adversos , Estimulação Transcraniana por Corrente Contínua/métodos , Animais , Encéfalo/metabolismo , Eletrodos , Encefalite/etiologia , Encefalite/metabolismo , Feminino , Microglia/metabolismo , Modelos Neurológicos , Ratos , Segurança
5.
J Wound Care ; 24(3): 140-2; 145-8, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25764959

RESUMO

OBJECTIVE: Chronic venous leg ulcers (CVLUs) are common and recurrent, however, care for patients predominantly has a focus which overlooks the impact of the condition on quality of life. The aim of this study was to develop a simple, evidence-based consultation template, with patients and practitioners, which focuses consultations on quality of life themes. METHOD: A nominal group was undertaken to develop a new consultation template for patients with CVLUs based on the findings of earlier qualitative study phases. RESULTS: A user-friendly two-sided A4 template was designed to focus nurse-patient consultations on the quality of life challenges posed by CVLUs. CONCLUSION: CVLUs impact negatively on the quality of life of the patient but this receives inadequate attention during current consultations. This new template will help to ensure that key concerns are effectively raised, explored and addressed during each consultation. DECLARATION OF INTEREST: The NHS West Midlands Strategic Health Authority funded this study. The authors have no conflicts of interest to declare.


Assuntos
Enfermagem Baseada em Evidências/métodos , Qualidade de Vida , Úlcera Varicosa/enfermagem , Úlcera Varicosa/psicologia , Adulto , Enfermagem Baseada em Evidências/normas , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Relações Enfermeiro-Paciente , Guias de Prática Clínica como Assunto , Pesquisa Qualitativa , Encaminhamento e Consulta , Inquéritos e Questionários , Cicatrização
6.
Neuroimage ; 85 Pt 3: 909-17, 2014 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-23235272

RESUMO

Sustained attention, often referred to as vigilance in humans, is the ability to maintain goal-directed behavior for extended periods of time and respond to intermittent targets in the environment. With greater time-on-task the ability to detect targets decreases and reaction time increases-a phenomenon termed the vigilance decrement. The purpose of this study was to examine the role of dorsolateral prefrontal cortex in the vigilance decrement. Subjects (n=19) received prefrontal transcranial direct current stimulation (tDCS) at one of two different time points during a vigilance task (early or late). The impact of tDCS was examined using measures of behavior, hemispheric blood flow velocity, and regional blood oxygenation relative to sham stimulation. In the sham condition greater time-on-task was accompanied by fewer target detections and slower reaction times, indicating a vigilance decrement, and decreased blood flow velocity. tDCS significantly altered baseline task-induced physiologic and behavioral changes, dependent on the time of stimulation administration and electrode configuration (determining polarity of stimulation). Compared to the sham condition, with more time-on-task blood flow velocity decreased less and cerebral oxygenation increased more in the tDCS condition. Behavioral measures showed a significant improvement in target detection performance with tDCS compared to the sham stimulation. Signal detection analysis revealed a significant change in operator discriminability and response bias with increased time-on-task, as well as interactions between time of stimulation administration and electrode configuration. Current density modeling of tDCS showed high densities in the medial prefrontal cortex and anterior cingulate cortex. These findings confirm that cerebral hemodynamic measures provide an index of resource utilization and point to the central role of the frontal cortex in vigilance. Further, they suggest that modulation of the frontal cortices-and connected structures-influences the availability of vigilance resources. These findings indicate that tDCS may be well-suited to mitigate performance degradation in work settings requiring sustained attention or as a possible treatment for neurological or psychiatric disorders involving sustained attention.


Assuntos
Atenção/fisiologia , Melhoramento Biomédico/métodos , Estimulação Elétrica , Córtex Pré-Frontal/fisiologia , Análise e Desempenho de Tarefas , Feminino , Humanos , Masculino , Córtex Pré-Frontal/irrigação sanguínea , Tempo de Reação/fisiologia
7.
J Cell Sci ; 125(Pt 5): 1177-90, 2012 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-22303000

RESUMO

Epithelial cell polarity is essential for animal development. The scaffold protein Bazooka (Baz/PAR-3) forms apical polarity landmarks to organize epithelial cells. However, it is unclear how Baz is recruited to the plasma membrane and how this is coupled with downstream effects. Baz contains an oligomerization domain, three PDZ domains, and binding regions for the protein kinase aPKC and phosphoinositide lipids. With a structure-function approach, we dissected the roles of these domains in the localization and function of Baz in the Drosophila embryonic ectoderm. We found that a multifaceted membrane association mechanism localizes Baz to the apical circumference. Although none of the Baz protein domains are essential for cortical localization, we determined that each contributes to cortical anchorage in a specific manner. We propose that the redundancies involved might provide plasticity and robustness to Baz polarity landmarks. We also identified specific downstream effects, including the promotion of epithelial structure, a positive-feedback loop that recruits aPKC, PAR-6 and Crumbs, and a negative-feedback loop that regulates Baz.


Assuntos
Membrana Celular/metabolismo , Polaridade Celular , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/embriologia , Drosophila melanogaster/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Animais , Proteínas de Drosophila/química , Células Epiteliais , Peptídeos e Proteínas de Sinalização Intracelular/química , Proteínas de Membrana/metabolismo , Fosfatidilinositóis/metabolismo , Proteína Quinase C/metabolismo , Estrutura Terciária de Proteína
8.
Fish Shellfish Immunol ; 38(1): 175-83, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24657318

RESUMO

Lepeophtheirus salmonis produces pharmacologically active substances that have been shown to modify genetic expression of inflammatory mediators in SHK-1 cells and head kidney macrophages of salmon. Differences in genetic expression among genera of Oncorhynchus and Salmo reflect different susceptibilities to L. salmonis. This study was conducted to determine if the presence of L. salmonis secretory products (SEPs)(1) alters the cellular innate immune response (specifically macrophage function) among several salmonids. Phagocytic assays were performed using SHK-1 cells and macrophages isolated from pink (Oncorhynchus gorbuscha), chum (Oncorhynchus keta) and Atlantic (Salmo salar) salmon following incubation with SEPs and Aeromonas salmonicida. Respiratory burst assays were analyzed using pink, chum and Atlantic salmon macrophages after exposure to SEPs. For SHK-1 cells, incubation with SEPS led to dose-dependent increases in phagocytosis. Following incubation with SEPs, chum salmon macrophages had the highest phagocytic index (55.1%) followed by Atlantic (26.4%) and pink (15.8%) salmon. In contrast, respiratory burst response was greatest in pink salmon and minimal in the other two species. Our results suggest that the cellular innate immune response of salmon is modified in the presence of L. salmonis secretions and differences observed among species provide insight into species-specific consequences of sea lice infection.


Assuntos
Copépodes/metabolismo , Imunidade Celular/efeitos dos fármacos , Fagocitose/efeitos dos fármacos , Proteínas/farmacologia , Animais , Células Cultivadas , Colorimetria , Dinoprostona/química , Dinoprostona/metabolismo , Dinoprostona/farmacologia , Feminino , Macrófagos , Masculino , Proteínas/metabolismo , Explosão Respiratória
9.
Adv Health Sci Educ Theory Pract ; 19(5): 661-85, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24449128

RESUMO

While formative workplace based assessment can improve learners' skills, it often does not because the procedures used do not facilitate feedback which is sufficiently specific to scaffold improvement. Provision of pre-formulated strategies to address predicted learning needs has potential to improve the quality and automate the provision of written feedback. To systematically develop, validate and maximise the utility of a comprehensive list of strategies for improvement of consultation skills through a process involving both medical students and their clinical primary and secondary care tutors. Modified Delphi study with tutors, modified nominal group study with students with moderation of outputs by consensus round table discussion by the authors. 35 hospital and 21 GP tutors participated in the Delphi study and contributed 153 new or modified strategies. After review of these and the 205 original strategies, 265 strategies entered the nominal group study to which 46 year four and five students contributed, resulting in the final list of 249 validated strategies. We have developed a valid and comprehensive set of strategies which are considered useful by medical students. This list can be immediately applied by any school which uses the Calgary Cambridge Framework to inform the content of formative feedback on consultation skills. We consider that the list could also be mapped to alternative skills frameworks and so be utilised by schools which do not use the Calgary Cambridge Framework.


Assuntos
Competência Clínica , Encaminhamento e Consulta , Competência Clínica/normas , Técnica Delphi , Educação Médica/métodos , Clínicos Gerais/psicologia , Clínicos Gerais/normas , Humanos , Estudantes de Medicina
10.
J Wound Care ; 23(12): 601-12, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25492276

RESUMO

OBJECTIVE: Chronic venous leg ulcers are common, intractable and often recurrent, but care tends to be wound focused, potentially overlooking the significant impact the condition has on patients' lives. A systematic review was undertaken to explore the factors that impact on the quality of life of patients with chronic venous leg ulceration. METHOD: Eligible articles published between 1990 and 2013 were identified via electronic searches of research databases (MEDLINE, CINAHL, BNI, EMBASE, PsycINFO, AMED and HMIC, Cochrane Collaboration database and Google Scholar). RESULTS: There were 23 studies (11 qualitative and 12 quantitative) that met the inclusion criteria. There were then the subject of a full review. The qualitative studies were collapsed into four core themes: physical, psychological, social implications and the nurse-patient relationship. The quantitative studies were grouped according to the tool applied. The review demonstrated that chronic venous leg ulcers impact negatively upon all areas of daily living. Pain, exudate, odour and the impact on mobility were daily challenges. The ability to engage with everyday functioning was restricted either owing to the ulcer, the dressing or to a self-imposed isolation in response to the impact of symptoms. Depression and low mood were common and yet, despite this, some studies reported that participants remained hopeful. CONCLUSION: Studies suggest that chronic venous leg ulceration negatively affects the quality of life of the patient and that such issues receive inadequate attention during current consultations. If such negative implications are to be effectively addressed, key issues need to be considered during every consultation. DECLARATION OF INTEREST: This study was funded by West Midlands Strategic Health Authority. The authors have no conflicts of interest to declare.


Assuntos
Atividades Cotidianas , Efeitos Psicossociais da Doença , Dor/psicologia , Qualidade de Vida/psicologia , Úlcera Varicosa/psicologia , Adaptação Psicológica , Doença Crônica , Exsudatos e Transudatos , Humanos , Dor/etiologia , Isolamento Social , Úlcera Varicosa/complicações , Úlcera Varicosa/enfermagem , Cicatrização
11.
Med Educ Online ; 29(1): 2320459, 2024 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-38404035

RESUMO

INTRODUCTION: The career choices of medical graduates vary widely between medical schools in the UK and elsewhere and are generally not well matched with societal needs. Research has found that experiences in medical school including formal, informal and hidden curricula are important influences. We conducted a realist evaluation of how and why these various social conditions in medical school influence career thinking. METHODS: We interviewed junior doctors at the point of applying for speciality training. We selected purposively for a range of career choices. Participants were asked to describe points during their medical training when they had considered career options and how their thinking had been influenced by their context. Interview transcripts were coded for context-mechanism-outcome (CMO) configurations to test initial theories of how career decisions are made. RESULTS: A total of 26 junior doctors from 12 UK medical schools participated. We found 14 recurring CMO configurations in the data which explained influences on career choice occurring during medical school. DISCUSSION: Our initial theories about career decision-making were refined as follows: It involves a process of testing for fit of potential careers. This process is asymmetric with multiple experiences needed before deciding a career fits ('easing in') but sometimes only a single negative experience needed for a choice to be ruled out. Developing a preference for a speciality aligns with Person-Environment-Fit decision theories. Ruling out a potential career can however be a less thought-through process than rationality-based decision theories would suggest. Testing for fit is facilitated by longer and more authentic undergraduate placements, allocation of and successful completion of tasks, being treated as part of the team and enthusiastic role models. Informal career guidance is more influential than formal. We suggest some implications for medical school programmes.


Assuntos
Escolha da Profissão , Estudantes de Medicina , Humanos , Faculdades de Medicina , Currículo , Atitude do Pessoal de Saúde
12.
J Wound Care ; 22(10): 534-6, 538-9, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24142075

RESUMO

OBJECTIVE: To quantify the extent to which patients disclose their concerns to community nurses during wound care consultations. METHOD: Using an 'observation checklist' based on themes and subthemes that were identified in a previous study of the same patients, 20 wound care consultations were observed. The non-participant observer completed the checklist and made field notes regarding the context and nature of interactions. RESULTS: Patient participants had 160 opportunities to raise concerns regarding previously-identified pain, exudate and odour, yet they did not do so on 64 (40%) occasions. They had 28, 32 and 84 opportunities to raise emotional, wound care and daily living issues, respectively, and they did not on 16 (56%), 3 (9%) and 32 (38%) occasions. Overall, patients did not raise 38% of their concerns. Of the concerns that were raised, 8% were either not acknowledged or were disregarded by their community nurse. CONCLUSION: If these data are representative, this has profound implications for person-centred care and shared decision-making models of care, which are predicated on patients articulating their needs. They also have implications for the development of practitioners' communication and consulting skills.


Assuntos
Relações Enfermeiro-Paciente , Atenção Primária à Saúde , Comunicação , Humanos , Participação do Paciente , Encaminhamento e Consulta
13.
J Wound Care ; 22(2): 58, 60-2, 64-6, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23665659

RESUMO

OBJECTIVE: To understand the personal impact of venous leg ulceration from the patients' perspective. METHOD: Face-to-face, unstructured interviews were conducted with nine patient participants with venous leg ulcers. The interviews were digitally recorded, transcribed verbatim and, using thematic analysis, the themes and subthemes which impacted on quality of life were identified. RESULTS: Four core themes were identified: the ulcer, symptoms, wound management and effects on daily life, with 16 subthemes that negatively impacted on quality of life (QoL) also identified. CONCLUSION: This qualitative study offers a valuable insight into the complex issues that impact on daily living for this patient group. The implications of the findings are far reaching and suggest that proactive symptom management and the fostering of a patient focus to consultations may improve QoL and encourage the patient to engage as an active partner in his/her management plan; both of which are explored in the subsequent phases of the larger study. DECLARATION OF INTEREST: This study was funded by West Midlands Strategic Health Authority. The authors have no conflicts of interest to declare.


Assuntos
Atividades Cotidianas , Qualidade de Vida , Úlcera Varicosa , Adaptação Psicológica , Adulto , Idoso , Idoso de 80 Anos ou mais , Doença Crônica , Exsudatos e Transudatos , Feminino , Humanos , Relações Interpessoais , Masculino , Odorantes , Dor/etiologia , Pesquisa Qualitativa , Autocuidado , Úlcera Varicosa/complicações , Úlcera Varicosa/enfermagem , Úlcera Varicosa/psicologia
14.
Aviat Space Environ Med ; 84(3): 184-9, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23513278

RESUMO

INTRODUCTION: Air-to-air refueling, formation flying, and projectile countermeasures all rely on a pilot's ability to be aware of his position and motion relative to another object. METHODS: Eight subjects participated in the study, all members of the sustained acceleration stress panel at Wright-Patterson AFB, OH. The task consisted of the subject performing a two-dimensional join up task between a KC-135 tanker and an F-16. The objective was to guide the nose of the F-16 to the posterior end of the boom extended from the tanker, and hold this position for 2 s. If the F-16 went past the tanker, or misaligned with the tanker, it would be recorded as an error. These tasks were performed during four G(z) acceleration profiles starting from a baseline acceleration of 1.5 G(z). The plateaus were 3, 5, and 7 G(z). The final acceleration exposure was a simulated aerial combat maneuver (SACM). RESULTS: One subject was an outlier and therefore omitted from analysis. The mean capture time and percent error data were recorded and compared separately. There was a significant difference in error percentage change from baseline among the G(z) profiles, but not capture time. Mean errors were approximately 15% higher in the 7 G profile and 10% higher during the SACM. DISCUSSION: This experiment suggests that the ability to accurately perceive the motion of objects relative to other objects is impeded at acceleration levels of 7 G(z) or higher.


Assuntos
Aceleração , Aviação , Hipergravidade , Militares , Análise e Desempenho de Tarefas , Adulto , Simulação por Computador , Feminino , Trajes Gravitacionais , Humanos , Masculino
15.
Neuroimage ; 59(1): 129-37, 2012 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-21840408

RESUMO

This paper proposes a shift in the way researchers currently view and use transcranial brain stimulation technologies. From a neuroscience perspective, the standard application of both transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS) has been mainly to explore the function of various brain regions. These tools allow for noninvasive and painless modulation of cortical tissue. In the course of studying the function of an area, many studies often report enhanced performance of a task during or following the stimulation. However, little follow-up research is typically done to further explore these effects. Approaching this growing pool of cognitive neuroscience literature with a neuroergonomics mindset (i.e., studying the brain at work), the possibilities of using these stimulation techniques for more than simply investigating the function of cortical areas become evident. In this paper, we discuss how cognitive neuroscience brain stimulation studies may complement neuroergonomics research on human performance optimization. And, through this discussion, we hope to shift the mindset of viewing transcranial stimulation techniques as solely investigatory basic science tools or possible clinical therapeutic devices to viewing transcranial stimulation techniques as interventional tools to be incorporated in applied science research and systems for the augmentation and enhancement of human operator performance.


Assuntos
Encéfalo/fisiologia , Estimulação Elétrica , Análise e Desempenho de Tarefas , Estimulação Magnética Transcraniana , Humanos
16.
PLoS Biol ; 6(10): e265, 2008 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-18959485

RESUMO

The mortality of salmon smolts during their migration out of freshwater and into the ocean has been difficult to measure. In the Columbia River, which has an extensive network of hydroelectric dams, the decline in abundance of adult salmon returning from the ocean since the late 1970s has been ascribed in large measure to the presence of the dams, although the completion of the hydropower system occurred at the same time as large-scale shifts in ocean climate, as measured by climate indices such as the Pacific Decadal Oscillation. We measured the survival of salmon smolts during their migration to sea using elements of the large-scale acoustic telemetry system, the Pacific Ocean Shelf Tracking (POST) array. Survival measurements using acoustic tags were comparable to those obtained independently using the Passive Integrated Transponder (PIT) tag system, which is operational at Columbia and Snake River dams. Because the technology underlying the POST array works in both freshwater and the ocean, it is therefore possible to extend the measurement of survival to large rivers lacking dams, such as the Fraser, and to also extend the measurement of survival to the lower Columbia River and estuary, where there are no dams. Of particular note, survival during the downstream migration of at least some endangered Columbia and Snake River Chinook and steelhead stocks appears to be as high or higher than that of the same species migrating out of the Fraser River in Canada, which lacks dams. Equally surprising, smolt survival during migration through the hydrosystem, when scaled by either the time or distance migrated, is higher than in the lower Columbia River and estuary where dams are absent. Our results raise important questions regarding the factors that are preventing the recovery of salmon stocks in the Columbia and the future health of stocks in the Fraser River.


Assuntos
Adaptação Biológica/fisiologia , Migração Animal/fisiologia , Rios , Salmão/fisiologia , Animais , Canadá , Ecossistema , Monitoramento Ambiental/instrumentação , Monitoramento Ambiental/métodos , Noroeste dos Estados Unidos , Telemetria/métodos
17.
J Fish Biol ; 78(2): 624-34, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21284639

RESUMO

The early marine migratory behaviour of two populations of hatchery-reared Atlantic salmon Salmo salar was compared in a common-garden experiment. Post-smolts from a river in a long fjord (Laerdal River, 144 km from the open coastline, n = 79) and a short fjord (Flekke River, 20 km from the open coastline, n = 80) in western Norway were tagged with acoustic transmitters and released during the spring of 2005 and 2006 in the inner part of the Hardangerfjord system (Opo River mouth, 179 km from the open coastline). The migratory behaviour of the tagged fish was monitored by acoustic listening stations in the fjord system up to 167 km from the release site. The Laerdal fish began migrating before the Flekke fish and had higher progression rates in the middle part of the fjord system. A greater number of Laerdal fish was detected along the most direct migratory route and in the outermost part of the Hardangerfjord system, which is indicative of a higher survival. The results from this study demonstrate differences in early marine migratory behaviour between S. salar from two different stocks and suggest that the distance a S. salar population travels to reach the open coastline may influence its early marine migratory behaviour and performance. The selective pressures of marine predation and arrival time at feeding areas in the ocean may be stronger for stocks with a longer inshore migration, creating more efficient migrants over time.


Assuntos
Migração Animal , Rios , Salmo salar/fisiologia , Acústica , Sistemas de Identificação Animal , Animais , Geografia , Noruega
18.
Aviat Space Environ Med ; 82(6): 635-42, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21702315

RESUMO

INTRODUCTION: Popular unmanned aerial system (UAS) platforms such as the MQ-1 Predator and MQ-9 Reaper have experienced accelerated operations tempos that have outpaced current operator training regimens, leading to a shortage of qualified UAS operators. To find a surrogate to replace pilots of manned aircraft as UAS operators, this study evaluated video game players (VGPs), pilots, and a control group on a set of UAS operation relevant cognitive tasks. METHODS: There were 30 participants who volunteered for this study and were divided into 3 groups: experienced pilots (P), experienced VGPs, and a control group (C). Each was trained on eight cognitive performance tasks relevant to unmanned flight tasks. RESULTS: The results indicated that pilots significantly outperform the VGP and control groups on multi-attribute cognitive tasks (Tank mean: VGP = 465 +/- 1.046 vs. P = 203 +/- 0.237 vs. C = 351 +/- 0.601). However, the VGPs outperformed pilots on cognitive tests related to visually acquiring, identifying, and tracking targets (final score: VGP = 594.28 +/- 8.708 vs. P = 563.33 +/- 8.787 vs. C = 568.21 +/- 8.224). Likewise, both VGPs and pilots performed similarly on the UAS landing task, but outperformed the control group (glide slope: VGP = 40.982 +/- 3.244 vs. P = 30.461 +/- 2.251 vs. C = 57.060 +/- 4.407). CONCLUSIONS: Cognitive skills learned in video game play may transfer to novel environments and improve performance in UAS tasks over individuals with no video game experience.


Assuntos
Aeronaves , Aviação , Aprendizagem , Desempenho Psicomotor , Análise e Desempenho de Tarefas , Jogos de Vídeo/psicologia , Adulto , Análise de Variância , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Militares
19.
Rural Remote Health ; 11(4): 1841, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22098058

RESUMO

The implementation of new curriculum at Keele University Medical School, UK has made heavy use of general practice as a locus for learning. This has necessitated a substantial expansion in the School's teaching network. The School's hinterland includes a large rural area with a number of excellent general practices and associated community hospitals that, to date, have been unable to teach undergraduates because of their inaccessibility. This article describes how the School and its partners articulated a vision to establish a rural campus with an associated rural accommodation hub, and the challenges involved in establishing and sustaining the campus.


Assuntos
Educação de Graduação em Medicina/organização & administração , Serviços de Saúde Rural/organização & administração , Faculdades de Medicina , Currículo , Inglaterra , Humanos , Avaliação de Programas e Projetos de Saúde , Parcerias Público-Privadas
20.
Front Hum Neurosci ; 15: 679977, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34456695

RESUMO

Transcranial direct current stimulation (tDCS) to the left prefrontal cortex has been shown to produce broad behavioral effects including enhanced learning and vigilance. Still, the neural mechanisms underlying such effects are not fully understood. Furthermore, the neural underpinnings of repeated stimulation remain understudied. In this work, we evaluated the effects of the repetition and intensity of tDCS on cerebral perfusion [cerebral blood flow (CBF)]. A cohort of 47 subjects was randomly assigned to one of the three groups. tDCS of 1- or 2-mA was applied to the left prefrontal cortex on three consecutive days, and resting CBF was quantified before and after stimulation using the arterial spin labeling MRI and then compared with a group that received sham stimulation. A widespread decreased CBF was found in a group receiving sham stimulation across the three post-stimulation measures when compared with baseline. In contrast, only slight decreases were observed in the group receiving 2-mA stimulation in the second and third post-stimulation measurements, but more prominent increased CBF was observed across several brain regions including the locus coeruleus (LC). The LC is an integral region in the production of norepinephrine and the noradrenergic system, and an increased norepinephrine/noradrenergic activity could explain the various behavioral findings from the anodal prefrontal tDCS. A decreased CBF was observed in the 1-mA group across the first two post-stimulation measurements, similar to the sham group. This decreased CBF was apparent in only a few small clusters in the third post-stimulation scan but was accompanied by an increased CBF, indicating that the neural effects of stimulation may persist for at least 24 h and that the repeated stimulation may produce cumulative effects.

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