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101.
Ranabir Pal Sumit Kar Forhad Akhtar Zaman Dilip Kumar Jha Shrayan Pal 《Indian Journal of Community Medicine》2012,37(3):170-173
Background:
We conducted a study to assess the impact of small group teaching (SGT) among students by feedback analysis to identify intricacy so that learning can be facilitated.Materials and Methods:
This cross-sectional study was undertaken among 182 MBBS students studying at a teaching hospital at Gangtok. Students were provided with a questionnaire following an assignment on a scheduled topic. Students were asked to provide feedback on the modes of teaching-learning practiced in community medicine with the parameters of evaluation including assessment of presentation by faculty member in reference to relevance, sequencing, depth, interaction, etc., to the overall rating of presentations in different teaching–learning methods.Results:
The faculty members were on the positive evaluation by the students in the SGT, which was preferred over lectures as the teaching–learning methods. Among SGTs “tutorials” were graded better than “practical”, “seminar” and “field posting” on the basis of longer duration at a stretch. Among the parameters for evaluation, relevance, depth, and interaction in regard to scheduled topic of presentations, the rating was significantly higher in SGT than different other teaching–learning methods. Largely the students noted that the time devoted and number of hours/sessions allotted for each topic was adequate.Conclusion:
All forms of SGT were on the positive appraisal by the students on their learning experience and were considered as a comprehensive tool for in-depth teacher–student interaction. 相似文献102.
目的 评价高危BPH采用经尿道反馈式微波治疗随访2年的疗效.方法 高危BPH患者62例(含门诊患者2例),均为年龄≥80岁或并发重要器官及系统严重病变或功能损害.治疗前前列腺体积、IPSS、QOL、Qmax分别为(62.03±50.69)ml、23.19±9.33、4.58±1.09、(4.33±3.75) ml/s.62例均在尿道表面麻醉下采用经尿道反馈式微波治疗,分别在治疗后3、12、24个月复查B超测量前列腺体积,复测IPSS、QOL及Qmax. 结果 62例均能耐受治疗,除轻微出血、感染及一过性尿失禁外,无明显外科并发症.治疗后3个月前列腺体积、IPSS评分、QOL评分、Qmax分别为(43.85±33.48)ml、11.63±7.14、2.44±1.36、(11.44±4.20) ml/s,治疗后12个月为(45.10±33.38) ml、12.23±7.33、2.61±1.33、(10.91±4.05) ml/s,治疗后24个月为(45.80±33.46) ml、12.37±7.48、2.66±1.40、(10.82±4.03) ml/s.治疗后各个时间点的各项指标均较治疗前显著改善(P<0.01). 结论 经尿道反馈式微波治疗高危BPH患者长期安全有效,可用于门诊治疗,治疗后3个月达到最佳疗效. 相似文献
103.
104.
Hongyi Li Ligang Wu Huijun Gao Xiaoxiang Hu Yulin Si 《Optimal control applications & methods.》2012,33(4):461-487
This paper addresses the problem of reference output tracking control for the longitudinal model of a flexible air‐breathing hypersonic vehicle (FAHV) by utilizing the output feedback control approach. The dynamic characteristics of the FAHV along with the aerodynamic effects of hypersonic flight make the flight control of such systems highly challenging. Moreover, there exist some intricate couplings between the engine and flight dynamics as well as complex interaction between rigid and flexible modes in the longitudinal model. These couplings bring difficulty to the flight control design for the intractable hypersonic vehicle systems. This paper deals with the problem of reference output tracking control for the longitudinal model of the FAHV. By utilizing the trim condition information including the state of altitude, velocity, angle of attack, pitch angle, pitch rate and so on, the linearized model is established for the control design objective. Then, the reference output velocity and altitude tracking control design problem is proposed for the linearized model. The flexible models of the FAHV system are hardly measured because of the complex dynamics and the strong couplings of the FAHV. Thus, by using only limited flexible model information, the reference output tracking performance analysis criteria are obtained via Lyapunov stability theory. Then, based on linear matrix inequality optimization algorithm, the static output feedback controller is designed to stabilize the closed‐loop systems, guarantee a certain bound for the closed‐loop value of the cost function, and can make the control output achieve the reference velocity and altitude tracking performance. Subsequently, the condition of dynamic output feedback controller synthesis is given in terms of linear matrix inequalities and a numerical algorithm is developed to search for a desired dynamic output feedback controller which minimizes the cost bound and obtains the excellent reference altitude and velocity tracking performance simultaneously. The effectiveness of the proposed reference output tracking control method is demonstrated in simulation part. Furthermore, the superior reference velocity and altitude performance commands could be achieved via using static and dynamic output feedback controllers under lacking some unmeasured flexible states information in the measurement output vector. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
105.
The impact of parkinson's disease on the cortical mechanisms that support auditory–motor integration for voice control 下载免费PDF全文
Xi Chen Jeffery A. Jones Emily Q. Wang Zhiqiang Guo Weifeng Li Peng Liu Hanjun Liu 《Human brain mapping》2016,37(12):4248-4261
Several studies have shown sensorimotor deficits in speech processing in individuals with idiopathic Parkinson's disease (PD). The underlying neural mechanisms, however, remain poorly understood. In the present event‐related potential (ERP) study, 18 individuals with PD and 18 healthy controls were exposed to frequency‐altered feedback (FAF) while producing a sustained vowel and listening to the playback of their own voice. Behavioral results revealed that individuals with PD produced significantly larger vocal compensation for pitch feedback errors than healthy controls, and exhibited a significant positive correlation between the magnitude of their vocal responses and the variability of their unaltered vocal pitch. At the cortical level, larger P2 responses were observed for individuals with PD compared with healthy controls during active vocalization due to left‐lateralized enhanced activity in the superior and inferior frontal gyrus, premotor cortex, inferior parietal lobule, and superior temporal gyrus. These two groups did not differ, however, when they passively listened to the playback of their own voice. Individuals with PD also exhibited larger P2 responses during active vocalization when compared with passive listening due to enhanced activity in the inferior frontal gyrus, precental gyrus, postcentral gyrus, and middle temporal gyrus. This enhancement effect, however, was not observed for healthy controls. These findings provide neural evidence for the abnormal auditory–vocal integration for voice control in individuals with PD, which may be caused by their deficits in the detection and correction of errors in voice auditory feedback. Hum Brain Mapp 37:4248–4261, 2016. © 2016 Wiley Periodicals, Inc. 相似文献
106.
Steven J. Lade Susa Niiranen Jonas Hentati-Sundberg Thorsten Blenckner Wiebren J. Boonstra Kirill Orach Martin F. Quaas Henrik ?sterblom Maja Schlüter 《Proceedings of the National Academy of Sciences of the United States of America》2015,112(35):11120-11125
Regime shifts triggered by human activities and environmental changes have led to significant ecological and socioeconomic consequences in marine and terrestrial ecosystems worldwide. Ecological processes and feedbacks associated with regime shifts have received considerable attention, but human individual and collective behavior is rarely treated as an integrated component of such shifts. Here, we used generalized modeling to develop a coupled social–ecological model that integrated rich social and ecological data to investigate the role of social dynamics in the 1980s Baltic Sea cod boom and collapse. We showed that psychological, economic, and regulatory aspects of fisher decision making, in addition to ecological interactions, contributed both to the temporary persistence of the cod boom and to its subsequent collapse. These features of the social–ecological system also would have limited the effectiveness of stronger fishery regulations. Our results provide quantitative, empirical evidence that incorporating social dynamics into models of natural resources is critical for understanding how resources can be managed sustainably. We also show that generalized modeling, which is well-suited to collaborative model development and does not require detailed specification of causal relationships between system variables, can help tackle the complexities involved in creating and analyzing social–ecological models.In recent decades, the world’s biological and physical systems have experienced dramatic change (1, 2). Many marine ecosystems, for example, have undergone abrupt changes known as regime shifts (3, 4). In one prominent case, the Baltic cod fishery suddenly changed in the 1980s from historically high cod biomass and catches (henceforth the “cod boom”) to a sprat-dominant ecosystem with low cod abundance (5–8). This collapse, generally understood to have been precipitated by deteriorating environmental conditions and overfishing (7), had substantial negative socioeconomic impact on Baltic Sea fisheries, including among others the small-scale coastal fishery (9).Ecological analyses of regime shifts, such as of the Baltic cod fishery (10), can capture the complex interplay of ecological and physical processes and drivers that trigger the shift. Numerous studies, however, have shown that understanding individual and collective human behavior is also critical for managing natural resources (11, 12) such as marine ecosystems (13, 14). Social–ecological system research responds to the need to incorporate humans as part of ecosystems by treating natural resource use as arising from linked systems of humans and nature, so-called social–ecological systems. Social–ecological system dynamics result from feedback loops involving biophysical processes, human behavior, and institutional processes within given social and biophysical contexts (15). Formal, quantitative analyses of the contributions of the social and biophysical subsystems to a social–ecological system’s dynamics are rare, however, because knowledge of social–ecological systems is often partial and spread over multiple disciplines (16).Here, we tested the influence of social dynamics on a regime shift in a marine ecosystem using a formal modeling framework. Specifically, we investigated the significance of fisher decision making, as influenced by psychological, economic, and regulatory factors, on the 1980s boom and collapse of the Eastern Baltic cod stock. In a significant advance for natural resource modeling, and for social–ecological modeling more generally, use of the generalized modeling approach (17, 18) enabled us to empirically parameterize, dynamically model, and analyze the qualitative social and ecological dynamics of the Baltic cod fishery at comparable levels of detail and without detailed specification of causal relationships. The Baltic cod fishery was selected because the ecological dynamics during the cod boom and collapse have been well-studied (10, 19, 20), and information about fisher behavior and institutional settings, such as regulation and subsidy policy, is available. Additionally, the cod boom and collapse are qualitatively distinct features of the social–ecological system’s dynamics that are amenable to the concepts and methods of dynamical systems theory (21), such as stability. 相似文献
107.
108.
Temporal modulation of the stress response is a ubiquitous characteristic of animals. Here, we investigate possible mechanisms underlying daily changes in corticosterone release in an ectotherm model system. Earlier work indicated that free-living Galápagos marine iguanas (Amblyrhynchus cristatus) have lower corticosterone concentrations during the night than during the day. This could result from: (i) a lower circadian secretion of adrenocorticotropic hormone (ACTH) as seen in mammals; (ii) from an increase in corticosterone negative feedback; or (iii) reflect lower metabolic activity during the night when core body temperature falls (from 35 degrees C during the day to as low as 21 degrees C during the night). To begin to distinguish between these three possibilities, exogenous ACTH was used to compare diel differences in adrenocortical tissue responsiveness, and dexamethasone was used to compare diel differences in the efficacy of corticosterone negative feedback. Low levels of exogenous ACTH (30 IU/kg body weight) potently stimulated both daytime and nighttime corticosterone release. Dexamethasone (1 mg/kg) inhibited only daytime, but not nighttime endogenous corticosterone release. Because the response to ACTH was similar between day and night we suggest that a simple lowering of core body temperature cannot explain the nighttime reduction in corticosterone release. However, the failure of negative feedback at night suggests that the response is not equivalent to the controlled downregulation seen in mammals. 相似文献
109.
Summary The relationship between insulin and the glucose-glucagon feedback mechanism was studied by testing the effectiveness of various routes, doses and timing of insulin administration prior to and during a glucose tolerance test in Peking ducks made transiently diabetic by subtotal pancreatectomy. Insulin injections or infusions given either before, or only during the glucose load, did not restore the A-cell response to glucose. Yet, if given both before and during the glucose test, in conditions which mimic the physiological basal insulin level and its variations (with, initially, intramuscular injections of 0.2 IU/kg and 8 g/kg glucagon, every six hours, and then an intravenous injection of 3.6 mU/kg plus an infusion of 0.9 mU/kg/ minute for one hour), the normal glucagon response to glucose was re-established. Insulin must therefore be present, both before and during glucose stimulation, for glucose to be effective as an A-cell suppressor.This work was supported by the CNRS (ERA 188) and the INSERM. 相似文献
110.
Stephens RS Roffman RA Fearer SA Williams C Burke RS 《Addiction (Abingdon, England)》2007,102(6):947-957
AIMS: To evaluate the efficacy of a two-session assessment and feedback intervention designed to reach and increase motivation for change in marijuana users who were experiencing negative consequences but were ambivalent about change. DESIGN: Random assignment to one of two types of feedback conditions or a delayed feedback control (DFC) with follow-up assessments at 7 weeks, 6 months and 12 months. Setting University of Washington research center in Seattle, Washington. PARTICIPANTS: A total of 188 adult male and female marijuana users who responded to advertisements. Interventions A personalized feedback (PF) condition utilizing motivational interviewing was compared to an educational control condition labeled multi-media feedback (MMF). MEASUREMENTS: Marijuana use, dependence symptoms, other associated negative consequences and motivational constructs were assessed at all time-points. FINDINGS: PF participants reported fewer days of use per week, fewer periods of use per day and fewer dependence symptoms at 7 weeks than those in the MMF and DFC conditions. PF participants also reported fewer days of use per week compared to MMF participants at the 12-month follow-up and fewer dependence symptoms at both the 6- and 12-month follow-ups compared to MMF participants. CONCLUSIONS: The PF intervention, delivered in the context of a check-up, shows potential as a way of reaching and motivating change in marijuana users with a diagnosable disorder who otherwise are not ready to approach treatment. Ways of augmenting the modest absolute levels of change are discussed. 相似文献