The impact of differential shifts in leader structure on the outcome of internal and external group participants

This study investigated the interaction between locus of control and high and low degrees of structure of leader role as related to outcome. On the basis of their pretreatment locus of control score, college students were assigned randomly to one of five groups: a group that began unstructured and shifted to a structured format at the midpoint of the group, a group that began structured and shifted to an unstructured format at the midpoint, a group that was structured throughout, a group that was unstructured throughout, and a notreatment control group. Treatment in the 23-hour marathon groups consisted of the same sequence of planned group exercises; the leader varied his structure in accordance with the experimental design. The results indicated that an initial highly structured leader role followed by a relatively unstructured leader role presented at the midpoint of treatment fostered the greatest gains in self-actualization in both internal and external Ss.     

Evaluation of structured and unstructured training for general practice

Twenty-four general-practice trainees were assessed at the beginning and end of their training year. They improved significantly in their factual recall and problem-solving ability. Sixteen young principals who had had an unstructured training for general practice were assessed at the same time and were initially of the same standard but their results showed no difference over the same year.     

Patterns of spontaneous activity in unstructured and minimally structured spinal networks in culture

The rhythmic activity observed in locomotion is generated by local neuronal networks in the spinal cord. The alternating patterns are produced by reciprocal connections between these networks. Synchronous rhythmic activity, but not alternation, can be reproduced in disinhibited networks of dissociated spinal neurons of rats. This suggests that a specific network architecture is required for pattern generation but not for rhythm generation. Here we were interested in the recruitment of neurons to produce population bursts in unstructured and minimally structured cultures of rat spinal cord grown on multielectrode arrays. We tested whether two networks, connected by a small number of axons, could be functionally separated into two units and generate more complex patterns such as alternation. In the unstructured cultures, we found that the recruitment of the neurons into bursting populations is divided into two steps: the fast recruitment of a trigger network, consisting of intrinsically firing cells connected in networks with short delays, and slow recruitment of the rest of the network. One or several trigger networks were observed in a single culture and could account for variable patterns of propagation. In the minimally structured cultures, a functional separation between loosely connected networks was achieved. Such separation led either to an independent bursting between the networks or to synchronized bursting with long and variable delays. However, no qualitatively novel pattern such as alternation could be generated. In addition, we found that the strength of reciprocal inhibitory connections was modulated by spontaneous activity.     

The effect of interpersonal competition on monitoring internal and external error feedback

The present study examined the effect of the social context on early emotional appraisal of performance errors and negative feedback reflected by the error‐related negativity (ERN), feedback‐related negativity (FRN), and P300. Participants performed a probabilistic learning task in which they received valid and invalid performance feedback. During one half of the task they were led to believe that they were competing online against another participant. As expected, the ERN following response errors was enhanced in the competition compared to the neutral condition. The FRN was more negative following negative compared to positive feedback and valid compared to invalid feedback, but only during competition. The P300 was larger to false positive than false negative feedback, which was independent of the social context. In conclusion, ERN and FRN, but not P300, may be sensitive to affective distress elicited by expectation violations during social interaction.     

Individual versus group therapy for obesity: effects of matching participants to their treatment preferences

This study examined the effects of matching participants to treatments on the basis of their preferences for either individual or group therapy for obesity. Seventy-five obese adults who expressed a clear preference for either individual or group therapy were randomly assigned to either their preferred or their nonpreferred treatment modality within a 2 (individual vs. group therapy) x 2 (preferred vs. nonpreferred modality) factorial design. At posttreatment, group therapy produced significantly greater reductions in weight and body mass than individual therapy, and no significant effects were observed for treatment preference or the interaction for treatment preference by type of therapy. All treatment conditions showed equivalent improvements in psychological functioning. These findings suggest that group therapy produces greater weight loss than individual therapy, even among those clients who express a preference for individual treatment.     

Super face-inversion effects for isolated internal or external features, and for fractured faces

Two experiments were conducted to determine the contributions of the face and object systems to the recognition of upright and inverted faces. In Experiment 1, CK, a person with object agnosia and normal recognition of upright faces, and 12 controls attempted to identify faces when presented with upright or inverted versions of the whole face, or with only their internal or external features. CK recognised as many upright whole faces as controls and the performance of both dropped slightly in the upright, internal feature condition. CK's recognition, however, was impaired in the upright, external condition, and severely impaired in the inverted whole condition, whereas control performance was equivalent in the two, and only somewhat worse than in the upright whole condition. Recognition in the inverted internal and external condition was extremely poor for all participants, leading to a super-inversion effect. This super-inversion effect suggested that recognition depends on more than just piecemeal identification of individual features. Experiment 2 was conducted to determine whether relational information is needed even for the identification of inverted faces. Twelve controls were required to identify whole and fractured faces in the upright and inverted orientation. The fractured faces had all the parts in the canonical order (eyes above nose above mouth) but they were separated by gaps, thereby altering the spatial relation among them. Recognition of inverted fractured faces was much worse than recognition of upright fractured faces and inverted whole faces, producing yet another super-inversion effect. The deficit in the inverted fractured condition was equal to the combined drop in performance in the other two conditions, indicating that the effects of inversion and fracturing are additive. On the basis of these results, we proposed that the face system forms holistic representations of faces based on orientation-specific global configurations primarily of internal features. When this information is unavailable, as when viewing inverted or fractured faces, the object system is needed to integrate information about individual features, which themselves may be orientation-specific, with information about the local or categorical relations among them into an object-system counterpart of the face-system representation. The creation of the facial counterpart by the object system and the consequent identification by the face system involves an exchange of information between the two systems according to an interactive activation model.     

MCL及ACL切断对膝内旋和外旋运动影响的实验研究

目的：研究膝内侧副韧带及前交叉韧带在膝旋转稳定性中的作用。方法：１４例膝关节，分为２组，分别切断内侧副韧带或前交叉韧带后，再切断另一韧带。分别测量切断前后的膝内旋外旋运动范围。结果：正常膝关节内旋外旋角度分别为２５．５°±４．８°及２１．４°±２．７°，两者差异显著。单纯切断前交叉韧带，对内、外旋无显著性影响；单纯切断内侧副韧带后，内旋运动范围有显著性增大，外旋也有显著性增大，当联合有前交叉韧带的切断时，对膝关节旋转运动影响更显著。结论：正常膝关节的内旋、外旋运动范围不等。前交叉韧带对内旋外旋无显著的限制作用；内侧副韧带是膝关节旋转运动的主要限制韧带     

Characteristics of participants in a large group awareness training

A study was conducted to assess the psychosocial characteristics of individuals who become involved in large group awareness training (LGAT) programs. Prospective participants in The Forum, which has been classified as an LGAT, were compared with nonparticipating peers and with available normative samples on measures of well-being, negative life events, social support, and philosophical orientation. Results revealed that prospective participants were significantly more distressed than peer and normative samples of community residents and had a higher level of impact of recent negative life events compared with peer (but not normative) samples. Prospective participants also held preparticipation values more similar to those espoused by the LGAT than peer or normative samples, and the three groups failed to be distinguished by their levels of social support. The implications of the findings are considered for understanding participation in LGATs and other self-change promoting activities.     

Medical students' perceptions of medical education research and their roles as participants.

PURPOSE: To better understand whether medical students perceive medical education research as important to their medical training and whether published opinions about why medical students participate in research are accurate. METHOD: In 2003-04, 896 first- through fourth-year medical students at Kansas City University of Medicine and Biosciences College of Osteopathic Medicine were asked to complete an online eight-item questionnaire by responding Yes or No to each question. Responses were tallied by year of medical training and converted into numbers and percentages. Chi-square analysis was used to compare response rates among first- through fourth-year students and responses between preclinical and clinical students. RESULTS: A total of 524 students (58.5%) completed the questionnaire. A total of 488 (93%) medical students believed medical education research should be conducted to improve their medical training, 477 (91%) did not feel coerced to participate in studies because of faculty members' positions of authority, and 398 (76%) did not believe they would receive better grades, recommendations, and/or other favors. Four hundred sixty-eight (89%) students were not concerned with their confidentiality as study participants, while 326 (62%) wanted special protections. Response rates by year of medical school were not significantly different (p > .05). Responses of preclinical and clinical students for six of the eight questions were significantly different (p < .05). CONCLUSIONS: Medical school decisionmakers should recognize that students value medical education research. Published opinions about why medical students participate in studies are incongruent with medical students' views. Full review of medical education studies by Institutional Review Boards may be unnecessary and inappropriate.     

Perspective display of patient external and internal contours

The two-dimensional perspective display of three-dimensional patient contour data is useful in radiotherapy treatment planning as it provides a comprehensive view of the relative positions of patient internal (organ and target) and external contours. The advent of minicomputers and video display systems has made possible the integration of such display techniques into the treatment planning routine. This paper describes and gives an example of the methods we have found useful in producing perspective displays of patient contour data. Included is a solution to the problem of removing hidden line segments from the displayed image.     

The effects of microenvironment and internal programming on plasma cell survival

Two populations of plasma cells (PCs) are formed after immunization. A short-lived population in the spleen and lymph nodes provides rapid protection. A long-lived population, mainly in the bone marrow, provides lasting immunity. The mechanisms responsible for the differences in PCs life span remain largely unknown. The goal of the current study was to compare the intrinsic survival capacity of isolated short-lived (spleen) versus long-lived (bone marrow) PCs. We approached this question by using a previously established in vitro model that measures PC survival in a supportive stromal environment. Regardless of the tissue source or isolation time point after immunization, the two PC populations showed similar intrinsic ability to survive in vitro. To test differences in the stromal microenvironments, stromal cells from marrow, spleen or lymph nodes were evaluated for ability to support PCs survival. Survival of isolated PC was always greater when co-cultured with marrow stromal cells compared with those from spleen (or lymph node) despite the finding that IL-6, necessary for PC survival in culture, was secreted by all three stromal cell sources. Additionally, low expression of B-cell-activating factor belonging to the tumor necrosis factor-family was detected in all three stromal isolates. In contrast, marrow stromal cells were distinguished by cell-surface phenotype and CXC chemokine ligand (CXCL)12, IL-7 and stem cell factor expression. Although CXCL12 has been suggested as a possible survival factor for PC, addition or neutralization of CXCL12 had minimal effect on PC survival. We conclude the mechanisms regulating PC longevity appear extrinsically driven and marrow favored, but the factors that give marrow stromal cells a unique advantage remain unknown.     

Influence of internal and external donors on activity and stereospecificity of ziegler-natta catalysts

Three kinds of MgCl₂-supported TiCl₄ catalysts (ester-free, ethyl benzoate (EB, monoester) and dibutyl phthalate (DNBP, diester) as internal donors) were prepared. Polymerization of propylene was carried out using these catalysts with and without phenyltriethoxysilane (PTES) as an external donor. Significant differences were observed in the kinetic behavior of polymerization among ester-free, monoester, and diester systems. Addition of PTES, however, did not change the kinetic behavior. The polymers produced were separated into three fractions by extraction with boiling heptane and octane, and the molar mass distribution (MMD) curves were measured for these three fractions. The heptane-insoluble, isotactic polymer obtained in the absence of PTES was found to consist of two fractions, octane-soluble and -insoluble. The octane-soluble polymer having lower molar mass contained appreciable amounts of syndiotactic stereoblocks in the chains, whereas the octane-insoluble polymer did not contain such stereoblocks. Addition of PTES drastically increased the octane-insoluble fraction without changing the average molar mass. On the other hand, the MMD curve for the heptane-soluble, atactic polymer gradually shifted to the lower molar mass range with an increase in the concentration of PTES. From these results, the effects of internal and external donors on catalyst activity and stereospecificity were discussed putting emphasis on the differences between monoesters and diesters.