3,416 research outputs found

    Fear and the human amygdala

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    We have previously reported that bilateral amygdala damage in humans compromises the recognition of fear in facial expressions while leaving intact recognition of face identity (Adolphs et al., 1994). The present study aims at examining questions motivated by this finding. We addressed the possibility that unilateral amygdala damage might be sufficient to impair recognition of emotional expressions. We also obtained further data on our subject with bilateral amygdala damage, in order to elucidate possible mechanisms that could account for the impaired recognition of expressions of fear. The results show that bilateral, but not unilateral, damage to the human amygdala impairs the processing of fearful facial expressions. This impairment appears to result from an insensitivity to the intensity of fear expressed by faces. We also confirmed a double dissociation between the recognition of facial expressions of fear, and the recognition of identity of a face: these two processes can be impaired independently, lending support to the idea that they are subserved in part by anatomically separate neural systems. Based on our data, and on what is known about the amygdala's connectivity, we propose that the amygdala is required to link visual representations of facial expressions, on the one hand, with representations that constitute the concept of fear, on the other. Preliminary data suggest the amygdala's role extends to both recognition and recall of fearful facial expressions

    Liquid pulsed plasma thruster plasma plume investigation and MR-SAT cold gas propulsion system performance analysis

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    The plasma plume produced by a liquid pulsed plasma thruster is investigated using a Langmuir triple probe and a nude Faraday probe. The Langmuir triple probe failed to produce results which are suspected caused by the presence of ionic liquid in the plume resulting in shorting of the probe. The nude Faraday probe is able to record the ion current density which revealed a high level of inconsistency in the plasma plume. Ion current density recorded by the nude Faraday probe had a relative standard deviation of upwards of 100% of the mean value. Controlling the amount of propellant used during each pulse was extremely difficult. Investigating the plasma plume with more complex probes was not done due to the inconsistency measured by the nude Faraday probe and the expulsion of ionic liquid from the thruster which is highly corrosive to metals. Examining the historical thrust test data performed by the Missouri Satellite Research Team, a revised model with new assumptions was created and resulted in an improvement in accuracy to within 4.5%. The cold gas propulsion system developed over the years had undergone testing which resulted in measured thrust half of what was predicted. Developing a thrust prediction scheme that incorporates the effects of the solenoid control valve decreases the error to between 1-3% depending on temperature considerations. This thrust prediction scheme can be applied to the current design for the NanoSat 8 competition and results in an accurate prediction of thrust --Abstract, page iii

    The Effect of Mechanical Overloading on Surface Roughness of the Coronary Arteries

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    Background. Surface roughness can be used to identify disease within biological tissues. Quantifying surface roughness in the coronary arteries aids in developing treatments for coronary heart disease. This study investigates the effect of extreme physiological loading on surface roughness, for example, due to a rupture of an artery. Methods. The porcine left anterior descending (LAD) coronary arteries were dissected ex vivo. Mechanical overloading was applied to the arteries in the longitudinal direction to simulate extreme physiological loading. Surface roughness was calculated from three-dimensional reconstructed images. Surface roughness was measured before and after damage and after chemical processing to dehydrate tissue specimens. Results. Control specimens confirmed that dehydration alone results in an increase of surface roughness in the circumferential direction only. No variation was noted between the hydrated healthy and damaged specimens, in both the longitudinal ( and ) and circumferential ( and ) directions. After dehydration, an increase in surface roughness was noted for damaged specimens in both the longitudinal () and circumferential () directions. Conclusions. Mechanical overloading applied in the longitudinal direction did not significantly affect surface roughness. However, when combined with chemical processing, a significant increase in surface roughness was noted in both the circumferential and longitudinal directions. Mechanical overloading causes damage to the internal constituents of the arteries, which is significantly noticeable after dehydration of tissue

    Lyme disease and pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS): an overview

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    Lyme disease (LD) is a complex, multisystemic illness. As the most common vector- borne disease in the United States, LD is caused by bacterial spirochete Borrelia burgdorferi sensu stricto, with potential coinfections from agents of anaplasmosis, babesiosis, and ehrlichiosis. Persistent symptoms and clinical signs reflect multiorgan involvement with episodes of active disease and periods of remission, not sparing the coveted central nervous system. The capability of microorganisms to cause and exacerbate various neuropsychiatric pathology is also seen in pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS), a recently described disorder attributed to bacterium Streptococcus pyogenes of group A beta-hemolytic streptococcus in which neurologic tics and obsessive-compulsive disorders are sequelae of the infection. In the current overview, LD and PANDAS are juxtaposed through a review of their respective infectious etiologies, clinical presentations, mechanisms of disease development, courses of illness, and treatment options. Future directions related to immunoneuropsychiatry are also discussed

    Emscher 3.0 : from grey to blue - or, how the blue sky over the Ruhr region fell into the Emscher

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    The river Emscher is - similar to the river Ruhr - the symbol of one of the internationally most renowned industrial regions: the Ruhr area with its 5 million inhabitants and an important location of key industries such as steel, chemical and materials industry. The revitalisation of the Emscher over the last 20 years marks a new phase in the region's history and is an impressive example of ecological and socio-economic transformation affecting all aspects of life along the river. What can we learn from the Emscher conversion for upcoming tasks in other infrastructure fields

    Finding the elusive balance between reducing fatigue and enhancing education: perspectives from American residents

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    Duty hour restrictions for residency training were implemented in the United States to improve residents' educational experience and quality of life, as well as to improve patient care and safety; however, these restrictions are by no means problem-free. In this paper, we discuss the positive and negative aspects of duty hour restrictions, briefly highlighting research on the impact of reduced duty hours and the experiences of American residents. We also consider whether certain specialties (e.g., Emergency Medicine, Radiology) may be more amenable than others (e.g., Surgery) to duty hour restrictions. We conclude that feedback from residents is a crucial element that must be considered in any future attempts to strike a balance between reducing fatigue and enhancing education

    The new middle level health workers training in the Amhara regional state of Ethiopia: students' perspective

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    BACKGROUND: Following health sector reform, Ethiopia started training new categories of health workers. This study addresses students' perspectives regarding their training and career plans. METHODS: A cross sectional questionnaire was administered to 145 students in the three schools of the Amhara regional state of Ethiopia. RESULTS: The majority of students were male (62%) and originally from urban areas (76%). Job search was the most common reason for enrolling in the training for almost half (48%) of the respondents, followed by a desire to help the sick (46%). Once trained, the majority (98%) of graduates preferred to serve in the government sector and in rural health institutions (84%). Females were more willing to work in rural settings [χ(2) (df 1)= 7.37; P = 0.007]. The majority (98%) of students felt the training period should be extended. 12% of graduates lacked confidence in their competencies after completing the training. A substantial proportion of the respondents (29%) did not feel the social science courses (Anthropology, Ecology and Psychology) were useful. CONCLUSIONS: This study demonstrates that mid-level health professional students are highly motivated, wish to address the health needs of rural communities, and are interested in professional development. However, students do not feel the training programs are fully addressing their needs. The students found that the duration of the training, the time for theory and practice, the availability of teaching materials, the course contents and their teachers were inadequate. This study suggests that the current training programs have serious inadequacies that need to be addressed
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