918 resultados para force-trauma
Resumo:
This project examines the challenges military chaplains face when leading Gospel services in the United States Air Force in both domestic and deployed locations. It argues that some chaplains assigned to Gospel services do not have the ministry skills set to lead them effectively. Through quantitative and qualitative research methods involving surveys of 30 military chaplains, lay leaders and parishioners, and follow-up interviews to explore critical issues identified by leaders and congregants alike, this project develops a Gospel service manual. This instructional primer outlines the historical evolution of the Gospel service and addresses its integral elements of worship and challenges that chaplains need to understand to meet the worship needs of multicultural and ecumenical military congregations.
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This article describes two neural network modules that form part of an emerging theory of how adaptive control of goal-directed sensory-motor skills is achieved by humans and other animals. The Vector-Integration-To-Endpoint (VITE) model suggests how synchronous multi-joint trajectories are generated and performed at variable speeds. The Factorization-of-LEngth-and-TEnsion (FLETE) model suggests how outflow movement commands from a VITE model may be performed at variable force levels without a loss of positional accuracy. The invariance of positional control under speed and force rescaling sheds new light upon a familiar strategy of motor skill development: Skill learning begins with performance at low speed and low limb compliance and proceeds to higher speeds and compliances. The VITE model helps to explain many neural and behavioral data about trajectory formation, including data about neural coding within the posterior parietal cortex, motor cortex, and globus pallidus, and behavioral properties such as Woodworth's Law, Fitts Law, peak acceleration as a function of movement amplitude and duration, isotonic arm movement properties before and after arm-deafferentation, central error correction properties of isometric contractions, motor priming without overt action, velocity amplification during target switching, velocity profile invariance across different movement distances, changes in velocity profile asymmetry across different movement durations, staggered onset times for controlling linear trajectories with synchronous offset times, changes in the ratio of maximum to average velocity during discrete versus serial movements, and shared properties of arm and speech articulator movements. The FLETE model provides new insights into how spina-muscular circuits process variable forces without a loss of positional control. These results explicate the size principle of motor neuron recruitment, descending co-contractive compliance signals, Renshaw cells, Ia interneurons, fast automatic reactive control by ascending feedback from muscle spindles, slow adaptive predictive control via cerebellar learning using muscle spindle error signals to train adaptive movement gains, fractured somatotopy in the opponent organization of cerebellar learning, adaptive compensation for variable moment-arms, and force feedback from Golgi tendon organs. More generally, the models provide a computational rationale for the use of nonspecific control signals in volitional control, or "acts of will", and of efference copies and opponent processing in both reactive and adaptive motor control tasks.
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Atomic force microscopy, which is normally used for DNA imaging to gain qualitative results, can also be used for quantitative DNA research, at a single-molecular level. Here, we evaluate the performance of AFM imaging specifically for quantifying supercoiled and relaxed plasmid DNA fractions within a mixture, and compare the results with the bulk material analysis method, gel electrophoresis. The advantages and shortcomings of both methods are discussed in detail. Gel electrophoresis is a quick and well-established quantification method. However, it requires a large amount of DNA, and needs to be carefully calibrated for even slightly different experimental conditions for accurate quantification. AFM imaging is accurate, in that single DNA molecules in different conformations can be seen and counted. When used carefully with necessary correction, both methods provide consistent results. Thus, AFM imaging can be used for DNA quantification, as an alternative to gel electrophoresis.
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BACKGROUND: Kinesin motors hydrolyze ATP to produce force and move along microtubules, converting chemical energy into work by a mechanism that is only poorly understood. Key transitions and intermediate states in the process are still structurally uncharacterized, and remain outstanding questions in the field. Perturbing the motor by introducing point mutations could stabilize transitional or unstable states, providing critical information about these rarer states. RESULTS: Here we show that mutation of a single residue in the kinesin-14 Ncd causes the motor to release ADP and hydrolyze ATP faster than wild type, but move more slowly along microtubules in gliding assays, uncoupling nucleotide hydrolysis from force generation. A crystal structure of the motor shows a large rotation of the stalk, a conformation representing a force-producing stroke of Ncd. Three C-terminal residues of Ncd, visible for the first time, interact with the central beta-sheet and dock onto the motor core, forming a structure resembling the kinesin-1 neck linker, which has been proposed to be the primary force-generating mechanical element of kinesin-1. CONCLUSIONS: Force generation by minus-end Ncd involves docking of the C-terminus, which forms a structure resembling the kinesin-1 neck linker. The mechanism by which the plus- and minus-end motors produce force to move to opposite ends of the microtubule appears to involve the same conformational changes, but distinct structural linkers. Unstable ADP binding may destabilize the motor-ADP state, triggering Ncd stalk rotation and C-terminus docking, producing a working stroke of the motor.
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Asymmetries in sagittal plane knee kinetics have been identified as a risk factor for anterior cruciate ligament (ACL) re-injury. Clinical tools are needed to identify the asymmetries. This study examined the relationships between knee kinetic asymmetries and ground reaction force (GRF) asymmetries during athletic tasks in adolescent patients following ACL reconstruction (ACL-R). Kinematic and GRF data were collected during a stop-jump task and a side-cutting task for 23 patients. Asymmetry indices between the surgical and non-surgical limbs were calculated for GRF and knee kinetic variables. For the stop-jump task, knee kinetics asymmetry indices were correlated with all GRF asymmetry indices (P < 0.05), except for loading rate. Vertical GRF impulse asymmetry index predicted peak knee moment, average knee moment, and knee work (R(2) ≥ 0.78, P < 0.01) asymmetry indices. For the side-cutting tasks, knee kinetic asymmetry indices were correlated with the peak propulsion vertical GRF and vertical GRF impulse asymmetry indices (P < 0.05). Vertical GRF impulse asymmetry index predicted peak knee moment, average knee moment, and knee work (R(2) ≥ 0.55, P < 0.01) asymmetry indices. The vertical GRF asymmetries may be a viable surrogate for knee kinetic asymmetries and therefore may assist in optimizing rehabilitation outcomes and minimizing re-injury rates.
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Trauma care in the general population has largely become protocol-driven, with an emphasis on fast and efficient treatment, good team communication at all levels of care including prehospital care, initial resuscitation, intensive care, and rehabilitation. Most available literature on trauma care has focused on adults, allowing the potential to apply concepts from adult care to pediatric care. But there remain issues that will always be specific to pediatric patients that may not translate from adults. Several new devices such as intraosseous (IO) needle systems and techniques such as ultrasonography to cannulate central and peripheral veins have become available for integration into our pre-existing trauma care system for children. This review will focus specifically on the latest techniques and evidence available for establishing intravenous access, rational approaches to fluid resuscitation, and blood product transfusion in the pediatric trauma patient.
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If you walk on sand, it supports your weight. How do the disordered forces between particles in sand organize, to keep you from sinking? This simple question is surprisingly difficult to answer experimentally: measuring forces in three dimensions, between deeply buried grains, is challenging. Here we describe experiments in which we have succeeded in measuring forces inside a granular packing subject to controlled deformations. We connect the measured micro-scale forces to the macro-scale packing force response with an averaging, mean field calculation. This calculation explains how the combination of packing structure and contact deformations produce the observed nontrivial mechanical response of the packing, revealing a surprising microscopic particle deformation enhancement mechanism.
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Using longitudinal data, the present study examined change in midlife neuroticism following trauma exposure. Our primary analyses included 670 participants (M(age) = 60.55; 65.22% male, 99.70% Caucasian) who completed the NEO Personality Inventory at ages 42 and 50 and reported their lifetime exposure to traumatic events approximately 10 years later. No differences in pre- and post-trauma neuroticism scores were found among individuals who experienced all of their lifetime traumas in the interval between the personality assessments. Results were instead consistent with normative age-related declines in neuroticism throughout adulthood. Furthermore, longitudinal changes in neuroticism scores did not differ between individuals with and without histories of midlife trauma exposure. Examination of change in neuroticism following life-threatening traumas yielded a comparable pattern of results. Analysis of facet-level scores largely replicated findings from the domain scores. Overall, our findings suggest that neuroticism does not reliably change following exposure to traumatic events in middle adulthood. Supplemental analyses indicated that individuals exposed to life-threatening traumas in childhood or adolescence reported higher midlife neuroticism than individuals who experienced severe traumas in adulthood. Life-threatening traumatic events encountered early in life may have a more pronounced impact on adulthood personality than recent traumatic events.
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The present study examined the impact of the developmental timing of trauma exposure on posttraumatic stress disorder (PTSD) symptoms and psychosocial functioning in a large sample of community-dwelling older adults (N = 1,995). Specifically, we investigated whether the negative consequences of exposure to traumatic events were greater for traumas experienced during childhood, adolescence, young adulthood, midlife, or older adulthood. Each of these developmental periods is characterized by age-related changes in cognitive and social processes that may influence psychological adjustment following trauma exposure. Results revealed that older adults who experienced their currently most distressing traumatic event during childhood exhibited more severe symptoms of PTSD and lower subjective happiness compared with older adults who experienced their most distressing trauma after the transition to adulthood. Similar findings emerged for measures of social support and coping ability. The differential effects of childhood compared with later life traumas were not fully explained by differences in cumulative trauma exposure or by differences in the objective and subjective characteristics of the events. Our findings demonstrate the enduring nature of traumatic events encountered early in the life course and underscore the importance of examining the developmental context of trauma exposure in investigations of the long-term consequences of traumatic experiences.
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Participants with posttraumatic stress disorder (PTSD) and participants with a trauma but without PTSD wrote narratives of their trauma and, for comparison, of the most-important and the happiest events that occurred within a year of their trauma. They then rated these three events on coherence. Based on participants' self-ratings and on naïve-observer scorings of the participants' narratives, memories of traumas were not more incoherent than the comparison memories in participants in general or in participants with PTSD. This study comprehensively assesses narrative coherence using a full two (PTSD or not) by two (traumatic event or not) design. The results are counter to most prevalent theoretical views of memory for trauma.
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We asked 1004 undergraduates to estimate both the probability that they would enter therapy and the probability that they experienced but could not remember incidents of potentially life-threatening childhood traumas or physical and sexual abuse. We found a linear relation between the expectation of entering therapy and the belief that one had, but cannot now remember, childhood trauma and abuse. Thus individuals who are prone to seek psychotherapy are also prone to accept a suggested memory of childhood trauma or abuse as fitting their expectations. In multiple regressions predicting the probability of forgotten memories of childhood traumas and abuse, the expectation of entering therapy remained as a substantial predictor when self-report measures of mood, anxiety, post-traumatic stress disorder symptom severity, and trauma exposure were included.
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The Centrality of Event Scale (CES) measures the extent to which a traumatic memory forms a central component of personnal identity, a turning point in the life story and a reference point for everyday inferences. In two studies, we show that the CES is positively correlated with severity of PTSD symptoms, even when controlling for measures of anxiety, depression, dissociation and self-consciousness. The findings contradict the widespread view that poor integration of the traumatic memory into one's life story is a main cause of PTSD symptoms. Instead, enhanced integration appears to be a key issue. Copyright © 2006 John Wiley & Sons, Ltd.
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We introduce a new scale that measures how central an event is to a person's identity and life story. For the most stressful or traumatic event in a person's life, the full 20-item Centrality of Event Scale (CES) and the short 7-item scale are reliable (alpha's of .94 and .88, respectively) in a sample of 707 undergraduates. The scale correlates .38 with PTSD symptom severity and .23 with depression. The present findings are discussed in relation to previous work on individual differences related to PTSD symptoms. Possible connections between the CES and measures of maladaptive attributions and rumination are considered along with suggestions for future research.
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BACKGROUND: Administrative or quality improvement registries may or may not contain the elements needed for investigations by trauma researchers. International Classification of Diseases Program for Injury Categorisation (ICDPIC), a statistical program available through Stata, is a powerful tool that can extract injury severity scores from ICD-9-CM codes. We conducted a validation study for use of the ICDPIC in trauma research. METHODS: We conducted a retrospective cohort validation study of 40,418 patients with injury using a large regional trauma registry. ICDPIC-generated AIS scores for each body region were compared with trauma registry AIS scores (gold standard) in adult and paediatric populations. A separate analysis was conducted among patients with traumatic brain injury (TBI) comparing the ICDPIC tool with ICD-9-CM embedded severity codes. Performance in characterising overall injury severity, by the ISS, was also assessed. RESULTS: The ICDPIC tool generated substantial correlations in thoracic and abdominal trauma (weighted κ 0.87-0.92), and in head and neck trauma (weighted κ 0.76-0.83). The ICDPIC tool captured TBI severity better than ICD-9-CM code embedded severity and offered the advantage of generating a severity value for every patient (rather than having missing data). Its ability to produce an accurate severity score was consistent within each body region as well as overall. CONCLUSIONS: The ICDPIC tool performs well in classifying injury severity and is superior to ICD-9-CM embedded severity for TBI. Use of ICDPIC demonstrates substantial efficiency and may be a preferred tool in determining injury severity for large trauma datasets, provided researchers understand its limitations and take caution when examining smaller trauma datasets.