144 research outputs found

    Disproportionate Correlation between Imaging and Outcome in an Infant with Cerebral Abscess

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    ObjectiveBrain abscesses represent organized foci of suppuration within the parenchyma. Here we report a 3 month-old girl with a very huge complicated cerebral abscess, and the course of treatment given. The patient's recovery was excellent. The follow up MRI showed only subtle porencephalic changes as the only parenchymal sequelae, which may be due to CNS plasticity in infants

    SOCIAL STATUS MODULATES RESTRAINT- INDUCED NEURAL ACTIVITY IN BRAIN REGIONS CONTROLLING STRESS VULNERABILITY 

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    Understanding the cellular mechanisms that control resistance and vulnerability to stress is an important step toward identifying novel targets for the prevention and treatment of stress-related mental illness. Dominant and subordinate animals have been shown to exhibit different behavioral and physiological responses to stress, with dominants often showing stress resistance and subordinates often showing stress vulnerability. We have previously found that dominant hamsters exhibit reduced social avoidance following social defeat stress compared to subordinate hamsters, although the extent to which stress resistance in dominants generalizes to non-social stressors is unknown. In this study, dominant, subordinate, and control male Syrian hamsters were exposed to acute restraint stress for 30 minutes. Brains were collected 60 minutes following restraint stress to quantify the number of c-Fos immunopositive cells in brain regions associated with stress-related behavior. Dominants and subordinates did not significantly differ in c-Fos immunoreactivity within subregions of the dorsal raphe nucleus or the paraventricular nucleus of the hypothalamus. However, compared to dominants and controls, subordinates displayed less restraint-induced c-Fos immunoreactivity in the infralimibic and prelimbic cortices. A similar trend was found in the ventral medial amygdala. These data are consistent with the reduced forebrain neural activity exhibited by subordinates following social defeat stress and suggest that subordinates exhibit a pattern of restraint-induced neural activity characteristic of stress vulnerability. However, dominant animals did not show restraint-induced changes in c- Fos immunoreactivity, suggesting that the cellular mechanisms controlling resistance to social defeat stress may not generalize to physical restraint

    Pediatric Head Injury

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    Minor trauma to the head is common in childhood and does not require any medical or surgical treatment. Nevertheless, head injury in infancy and childhood is the single most common cause of death and permanent disability. Measurable deficits occur even after mild to moderate head injury but are markedly greater after severe injury. They include impaired cognition, motor impairments, disruption of attention and information processing, and psychiatric disturbances. Despite the frequency of the sequelae of head injury in childhood, there is relatively little information about the structural basis of the clinical deficits. Classical literature suggests that the immature brain and its coverings, at a time when it is rapidly acquiring new information, respond differently from the adult brain when subjected to an equivalent amount of mechanical force, whether mediated by contact or inertial loading. Identification of different patterns of injury in different age groups has resonance in clinical practice and now provides a reference point for future clinical and neuropathological studies. This work not only provides the basis for the future management of patients, but also serves to remind us of the continuing value of the autopsy and the proper examination of retained organs using modernstandardized techniques

    Transition of Transient Channel Flow with High Reynolds Number Ratios

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    Large-eddy simulations of turbulent channel flow subjected to a step-like acceleration have been performed to investigate the effect of high Reynolds number ratios on the transient behaviour of turbulence. It is shown that the response of the flow exhibits the same fundamental characteristics described in He & Seddighi (J. Fluid Mech., vol. 715, 2013, pp. 60–102 and vol. 764, 2015, pp. 395–427)—a three-stage response resembling that of the bypass transition of boundary layer flows. The features of transition are seen to become more striking as the Re-ratio increases—the elongated streaks become stronger and longer, and the initial turbulent spot sites at the onset of transition become increasingly sparse. The critical Reynolds number of transition and the transition period Reynolds number for those cases are shown to deviate from the trends of He & Seddighi (2015). The high Re-ratio cases show double peaks in the transient response of streamwise fluctuation profiles shortly after the onset of transition. Conditionally-averaged turbulent statistics based on a λ_2-criterion are used to show that the two peaks in the fluctuation profiles are due to separate contributions of the active and inactive regions of turbulence generation. The peak closer to the wall is attributed to the generation of “new” turbulence in the active region, whereas the peak farther away from the wall is attributed to the elongated streaks in the inactive region. In the low Re-ratio cases, the peaks of these two regions are close to each other during the entire transient, resulting in a single peak in the domain-averaged profile

    Temporal acceleration of a turbulent channel flow

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    We report new laboratory experiments of a flow accelerating from an initially turbulent state following the opening of a valve, together with large eddy simulations of the experiments and extended Stokes first problem solutions for the early stages of the flow. The results show that the transient flow closely resembles an accelerating laminar flow superimposed on the original steady turbulent flow. The primary consequence of the acceleration is the temporal growth of a boundary layer from the wall, gradually leading to a strong instability causing transition. This extends the findings of previous direct numerical simulations of transient flow following a near-step increase in flow rate. In this interpretation, the initial turbulence is not the primary characteristic of the resulting transient flow, but can be regarded as noise, the evolution of which is strongly influenced by the development of the boundary layer. We observe the spontaneous appearance of turbulent spots and discontinuities in the velocity signals in time and space, revealing rich detail of the transition process, including a striking contrast between streamwise and wall-normal fluctuating velocities

    An experimental study on boundary layer transition detection over a pitching supercritical airfoil using hot-film sensors

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    In the present work, experimental tests are conducted to study boundary layer transition over a supercritical airfoil undergoing pitch oscillations using hot-film sensors. Tests have been undertaken at an incompressible flow. Three reduced frequencies of oscillations and two mean angles of attack are studied and the influences of those parameters on transition location are discussed. Different algorithms are examined on the hot-film signals to detect the transition point. Results show the formation of a laminar separation bubble near the leading edge and at relatively higher angles of attack which leads to the transition of the boundary layer. However, at lower angles of attack, the amplification of the peaks in voltage signal indicate the emergence of the vortical structures within the boundary layer, introducing a different transition mechanism. Moreover, an increase in reduced frequency leads to a delay in transition onset, postponing it to a higher angle of attack, which widens the hysteresis between the upstroke and downstroke motions. Rising the reduced frequency yields in weakening or omission of vortical disturbances ensuing the removal of spikes in the signals. Of the other important results observed, is faster movement of the relaminarization point in the higher mean angle of attack. Finally, a time–frequency analysis of the hot-film signals is performed to investigate evolution of spectral features of the transition due to the pitching motion. An asymmetry is clearly observed in frequency pattern of the signals far from the bubble zone towards the trailing edge; this may reflect the difference between the transition and relaminarization physics. Also, various ranges of frequency were obtained for different transition mechanisms

    A Safe Home? A Qualitative Study into the Experiences of Adolescents Growing Up in the Dutch Area Impacted by Earthquakes Induced by Gas Extraction

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    For decades, the Netherlands has experienced minor earthquakes due to gas extraction. This study aims to obtain insight into the experiences of adolescents and the impact of these earthquakes on their well-being and living environment. Focus groups were held with 24 adolescents, and interviews were held with 3 adolescents (N = 27; M = 15 years). Through qualitative analysis, we identified six themes. The adolescents shared experiences of anxiety related to the earthquakes and their consequences and considered these to be a normal part of their life. Anxiety and feelings of endangerment not only related to their own experiences but were also connected to the impact of earthquakes on their social environment, such as the restoration of buildings. Several sources of support (e.g., talking, social cohesion) were mentioned to deal with the negative consequences of the earthquakes. A lack of trust in the government was an additional main theme, with adolescents mentioning several needs, potentially relevant to policymakers in the Netherlands. Growing up in the gas extraction area of Groningen had many consequences on the adolescents in the study, who felt inhibited from expressing feelings of anxiety and fear. To support their needs, interventions at the individual, family, educational, societal, and policy levels are recommended. View Full-Tex

    Increasing cardiovascular medication adherence:A Medical Research Council complex mHealth intervention mixed-methods feasibility study to inform global practice

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    AimsTo evaluate a mHealth intervention to increase medication adherence among Iranian coronary heart disease patients.DesignQuantitative-dominant mixed-methods study.Data SourceIranian coronary heart disease patients’ responses and most recent clinical documents as well as responses from Iranian cardiac nurses who participated in this study.MethodsThe study was conducted between September 2015–April 2016 drawing on the Medical Research Council's Framework. Phase one comprised of a patients’ survey and focus groups with cardiac nurses. The automated short message service reminder was piloted in phase two. We recruited 78 patients and randomized to receive either 12-week daily reminders or usual care. The primary outcome was the effect on medication adherence; secondary outcomes were self-efficacy, ejection fraction, functional capacity, readmission rate and quality of life.ResultsFeasibility was evidenced by high ownership of mobile phones and high interest in receiving reminders. Participants in the intervention group showed significantly higher medication adherence compared with the control group.ConclusionThe mHealth intervention was well accepted and feasible with early evidence of effectiveness that needs to be confirmed in a fully powered future randomized clinical trial

    Challenges to promoting population-based cancer registration in Iran: A workshop report

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    In December 2011, the Cancer Research Centre of the Cancer Institute of Iran sponsored a 3-day workshop on "Cancer Registration Principle and Challenges in Iran", which convened cancer registry experts. The objectives of the workshop were: to introduce standard cancer registration, to review the policy and procedure of cancer registration in Iran, and to review the best practices in the cancer registries in Iran. Challenges to cancer registration were discussed and recommendations were developed. The workshop was evaluated by participants for better organization of subsequent workshops. The objective of publication of this report is that based on Cancer in 5 Continents, many low- or middle-income countries do not meet the criteria for a standard population-based cancer registry (PBCR); on the other hand cancer is the most important cause of mortality and the essential part of any cancer control program is the cancer registry. Therefore this report focuses on problems and challenges of PBCR and provides recommendations which might help other developing countries to decrease their PBCR defects
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