Les usages épistémiques des réseaux de communication électronique : Le cas de l’Open-Source

The concept of “distributed cognition” is applied to analyzing communication networks on Internet in order to better understand the role of electronic communications in acquiring and producing knowledge. This case study has as its basis a mailing list to the users of the free software “Debian.user.french”. The communication networks that emerged out of discussions on “threads” determined how knowledge was distributed among persons on the list. The structure of these threads limits the transmission of knowledge and gives rise to two types of epistemic networks: advice networks and discussion networks. Electronic communication networks facilitate the coexistence of these two types in a single community. Procedures that lead to a discussion of advices serve to select informants with a reputation and to develop cooperative structures out of the relationships formed while giving advice. This coexistence of various epistemic uses characterizes open-source communities, since it combines the cooperative production of a body of knowledge and the transmission of instructions to learners.     

Longer Life and Population Growth

Enthusiasm about the prospect of large increases in human life expectancy is often dampened by fears that lower mortality will increase population size, hence population pressure. A simple mathematical model of life-cycle stretching demonstrates that if increased longevity is accompanied by later childbearing, a trend that is already underway, future declines in mortality will not increase population size.     

Adolescent fathers involved with child protection: social workers speak

This study examined adolescent paternity through structured interviews with their social workers. It adds to the literature by exploring if there were young men involved with the child protection services (CPS) system who are fathers, identifying their unique needs, and beginning discussions on working with these young men. CPS social workers from six area offices and one juvenile detention facility completed surveys for each father on their caseload. A 3.5% rate of adolescent paternity was observed across these offices. Information about the nature of the young men's involvement with CPS, their involvement with their children, and their unique needs as fathers are provided. This paper also identifies some practice and policy implications for adolescent fathers and CPS charged with their care.     

Socioeconomic stress in rural families: Part II from the co-guest editors

Dorothy Z. Price is Professor, Child and Family Studies, Washington State University, Pullman, WA 99164-2010. Mari S. Wilhelm is Associate Professor, School of Family and Consumer Resources, University of Arizona, Tucson, AZ 85721.     

Role of physical activity in tumor patients and possible underlying mechanisms

A growing knowledge regarding the influence of exercise on adverse physiologic outcomes associated with cancer and its treatment exists. Aside from its effects on psychological behavior, quality of life, and cancer-related fatigue, physical exercise can target physical and cardio-respiratory fitness, insulin regulation and metabolic syndrome, body weight and composition, and immune function in tumor patients. The increasing number of study results for different cancer types, which prove the positive influences of physical activity in cancer patients, changed the contradictory opinions which existed until the end of the last century. Although an increasing number of studies showing the positive effects of physical activity and more specifically of endurance and resistance training in cancer patients have been published, the underlying mechanisms are mostly unknown. Thus, we summarized the current knowledge of the effects of physical activity and specific training in different tumor entities with specific respect to the possible underlying mechanisms. Especially, the association between physical activity and (1) the improvement of fatigue and the role of free radicals in this process, (2) the counterbalance of tumor-induced cachexia, (3) the improvement of the immune system for supportive tumor treatment, and (4) the possible role of epigenetic modulation against tumor and tumor treatment-dependent adverse physiologic outcomes is focused.     

A 1,408 km bicycle tour with prostate cancer patients—results of a pilot study

Negative psychological and physical effects of prostate cancer and its medical treatment may persist many years after diagnosis. The influence of a long cycling tour on rehabilitative or health-related effects with prostate cancer patients has not yet been studied. In practice, physicians and therapists rarely recommend cycling to prostate cancer. In May 2010, eight prostate cancer patients rode their bikes for over 1,408 km from Cologne to Marseille within 5 weeks. Endurance test, blood examinations (prostate-specific antigen (PSA), total testosterone, interleukin-6, oxidative stress, and antioxidant capacity) and quality of life questionnaires were completed before and after the tour. All eight subjects reached Marseille. Significant improvements could be observed in physical performance and certain quality of life scores (p?=?0.008), as well as a reduction of total testosterone (p?=?0.19). PSA levels did not change. This pilot study suggests that long bicycle tours with prostate cancer patients are feasible. Due to the missing control group and the small sample size, the results of this pilot study are limited.     

Adaptation to unemployment: Effects of a mine closure on husbands and wives

The purpose of this study was to increase understanding of how individuals/couples respond to the unemployment of the primary breadwinner. Data were collected from 66 individuals (33 couples) shortly after becoming unemployed and again one year later. Results determined that the significant predictor variables of economic satisfaction, marital adjustment, and depression were primarily economic, marital, and emotional variables, respectively. Findings also showed that interaction existed among economic, marital, and emotional variables in predicting the three well-being outcomes. Additionally, differences were found in the pattern of results for husbands and for wives. Based on these findings, areas and hypotheses for future study are proposed.Carl A. Ridley received his Ph.D. from Florida State University. He is a Professor in the Division of Child Development and Family Relations, University of Arizona, Tucson, AZ 85721. His research interests include relationships and conflict management.Mari S. Wilhelm received her Ph.D. from Michigan State University. She is an Assistant Professor in the School of Family and Consumer Resources, University of Arizona, Tucson, AZ 85721. Her research interests include financial management, socio-economic stress, financial stress and problems.     

A statistical method to convert published response rates into marginal distributions with an example application in psoriasis

Assessment of severity is essential for the management of chronic diseases. Continuous variables like scores obtained from the Hamilton Rating Scale for Depression or the Psoriasis Area and Severity Index (PASI) are standard measures used in clinical trials of depression and psoriasis. In clinical trials of psoriasis, for example, the reduction of PASI from baseline in response to therapy, in particular the proportion of patients achieving at least 75%, 90%, or 100% improvement of disease (PASI 75, PASI 90, or PASI 100), is typically used to evaluate treatment efficacy. However, evaluation of the proportions of patients reaching absolute PASI values (eg, ≤1, ≤2, ≤3, or ≤5) has recently gained greater clinical interest and is increasingly being reported. When relative versus absolute scores are standard, as is the case with the PASI in psoriasis, it is difficult to compare absolute changes using existing published data. Thus, we developed a method to estimate absolute PASI levels from aggregated relative levels. This conversion method is based on a latent 2‐dimensional normal distribution for the absolute score at baseline and at a specific endpoint with a truncation to allow for baseline inclusion criterion. The model was fitted to aggregated results from simulations and from 3 phase III studies that had known absolute PASI proportions. The predictions represented the actual results quite precisely. This model might be applied to other conditions, such as depression, to estimate proportions of patients achieving an absolute low level of disease activity, given absolute values at baseline and proportions of patients achieving relative improvements at a subsequent time point.     

Karl-Heinz Hillmann: Überlebensgesellschaft. Von der Endzeitgefahr zur Zukunftssicherung. Mit Beiträgen von Thomas Goppel und Hubert Weinzierl

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