254 research outputs found
Chromosome Oscillations in Mitosis
Successful cell division requires a tight regulation of chromosome motion via
the activity of molecular motors. Many of the key players at the origin of the
forces generating the movement have been identified, but their spatial and
temporal organization remains elusive. The protein complex Kinetochore on the
chromosome associates with microtubules emanating from one of the spindle poles
and drives the chromosome toward the pole. Chromokinesin motors on the
chromosome arms also interact with microtubules, ejecting the chromosome away
from the pole. In animal cells, a monooriented chromosome (associated to a
single pole) periodically switches between phases of poleward and away from the
pole movement[, a behavior tentatively explained so far by the existence of a
complex switching mechanism within the kinetochore itself. Here we show that
the interplay between the morphology of the mitotic spindle and the collective
kinetics of chromokinesins can account for the highly non-linear periodic
chromosome motion. Our analysis provides a natural explanation for the origin
of chromosome directional instability and for the mechanism by which
chromosomes feel their position in space.Comment: http://hogarth.pct.espci.fr/~pierre
Empowerment evaluation of a Swedish gender equity plan
Background: Empowerment is essential for gender equity and health. The city of Malmö, Sweden, has formulated a development plan for gender equity integration (GEIDP). A ‘Policy Empowerment Index’ (PEI) was previously developed to assess the empowerment potential of policies. Objectives: To pilot-evaluate the GEIDP's potential for empowerment and to test the PEI for future policy evaluations. Design: The GEIDP was analyzed and scored according to electronically retrieved evidence on constituent opinion, participation, capacity development, evaluation–adaptation, and impact. Results: The plan's PEI score was 64% (CI: 48–78) and was classified as ‘enabling’, ranging between ‘enabling’ and ‘supportive’. The plan's strengths were: 1) constituent knowledge and concern; 2) peripheral implementation; 3) protection of vulnerable groups; and 4) evaluation/adaptation procedures. It scored average on: 1) policy agenda setting; 2) planning; 3) provisions for education; 4) network formation; 5) resource mobilization. The weakest point was regarding promotion of employment and entrepreneurship. Conclusions: The PEI evaluation highlighted the plan's potential of constituency empowerment and proposed how it could be augmented
Amlodipine+Benazepril is Superior to Hydrochlorothiazide+Benazepril Irrespective of Baseline Pulse Pressure: Subanalysis of the ACCOMPLISH Trial
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/110751/1/jch12460.pd
The pathway of obstructed labour as perceived by communities in south-western Uganda: a grounded theory study
BACKGROUND: Obstructed labour is still a major cause of maternal and perinatal morbidity and mortality in Uganda, where many women give birth at home alone or assisted by non-skilled birth attendants. Little is known of how the community view obstructed labour, and what actions they take in cases where this complication occurs. OBJECTIVE: The objective of the study was to explore community members' understanding of and actions taken in cases of obstructed labour in south-western Uganda. DESIGN: Grounded theory (GT) was used to analyse data from 20 focus group discussions (FGDs), 10 with women and 10 with men, which were conducted in eight rural and two urban communities. RESULTS: A conceptual model based on the community members' understanding of obstructed labour and actions taken in response is presented as a pathway initiated by women's desire to 'protecting own integrity' (core category). The pathway consisted of six other categories closely linked to the core category, namely: (1) 'taking control of own birth process'; (2) 'reaching the limit - failing to give birth' (individual level); (3) 'exhausting traditional options'; (4) 'partner taking charge'; (5) 'facing challenging referral conditions' (community level); and finally (6) 'enduring a non-responsive healthcare system' (healthcare system level). CONCLUSIONS: There is a need to understand and acknowledge women's reluctance to involve others during childbirth. However, the healthcare system should provide acceptable care and a functional referral system closer to the community, thus supporting the community's ability to seek timely care as a response to obstructed labour. Easy access to mobile phones may improve referral systems. Upgrading of infrastructure in the region requires a multi-sectoral approach. Testing of the conceptual model through a quantitative questionnaire is recommended
Experience of sexual coercion and risky sexual behavior among Ugandan university students
<p>Abstract</p> <p>Background</p> <p>Growing worldwide evidence shows that the experience of sexual coercion is fairly prevalent among young people and is associated with risky sexual behavior thereafter. The causal mechanisms behind this are unclear but may be dependent on specific contextual determinants. Little is known about factors that could buffer the negative effects of coercion. The aim of this study was to assess the association between the experience of sexual coercion and risky sexual behavior among university students of both sexes in Uganda.</p> <p>Methods</p> <p>In 2005, 980 (80%) out of a total of 1,220 students enrolled in Mbarara University of Science and Technology in Uganda participated in a self-administered questionnaire covering socio-demographic and religious factors, social capital, mental health, alcohol use, and sexual behavior. A validated scale of six items was used to assess the experience of sexual coercion. Logistic regression analyses were applied to control for confounders. Potential buffering factors were analyzed by testing for effect modification.</p> <p>Results</p> <p>Fifty-nine percent of those who responded had previously had sexual intercourse. Among the male students 29.0%, and among the female students 33.1% reported having had some experience of sexual coercion. After controlling for age, gender, and educational level of household of origin, role of religion and trust in others sexual coercion was found to be statistically significantly associated with previously had sex (OR 1.6, 95% CI; 1.1-2.3), early sexual debut (OR 2.4, 95% CI; 1.5-3.7), as well as with having had a great number of sexual partners (OR 1.9, 95% CI; 1.2-3.0), but not with inconsistent condom use.</p> <p>Scoring low on an assessment of mental health problems, reporting high trust in others, or stating that religion played a major role in one's family of origin seemed to buffer the negative effect that the experience of sexual coercion had on the likelihood of having many sexual partners.</p> <p>Conclusion</p> <p>The findings of this study suggest that the experience of sexual coercion is common among youth/young adults in Uganda and is subsequently associated with risky sexual behavior in both sexes. The existence of individual and contextual factors that buffer the effects mentioned was also demonstrated. In the Ugandan context, this has implications for policy formulation and the implementation of preventive strategies for combating HIV/AIDS.</p
Synergistic interaction effect between job control and social support at work on general psychological distress
Purpose Little is known about the interaction between job control and social support at work on common mental disorders. To examine whether there is a synergistic interaction effect between job control and social support at work on general psychological distress and whether it differs by the level of job demands. Methods About 1,940 male and female workers from the Malmo Shoulder and Neck Study were chosen for this cross-sectional study. Job control, social support at work, and job demands were measured by the Swedish version of the Job Content Questionnaire, and general psychological distress was assessed by the General Health Questionnaire. Results A significant excessive risk increase for general psychological distress was observed when workers had both low job control and low social support at work in both men and women. The synergistic effect was stronger in women, when job demands were low (Rothman's synergy index was 2.16 vs. 1.51 when job demands were high). However, in male workers, while a strong synergistic effect between job control and social support at work was found when job demands were low (synergy index was 9.25), there was an antagonistic effect when job demands were high (synergy index was 0.52). Conclusions There was a synergistic interaction effect between job control and social support at work on general psychological distress, but the synergistic effect or its effect size differed by the level of job demands and gender. An atomic, additive approach to the risk assessment of the psychosocial work characteristics on common mental disorders could be misleading or lead to a risk underestimation
The Impact of Socio-Demographic and Religious Factors upon Sexual Behavior among Ugandan University Students
INTRODUCTION: More knowledge is needed about structural factors in society that affect risky sexual behaviors. Educational institutions such as universities provide an opportune arena for interventions among young people. The aim of this study was to investigate the relationship between sociodemographic and religious factors and their impact on sexual behavior among university students in Uganda. METHODS: In 2005, 980 university students (response rate 80%) were assessed by a self-administered questionnaire. Validated instruments were used to assess socio-demographic and religious factors and sexual behavior. Logistic regression analyses were applied. RESULTS: Our findings indicated that 37% of the male and 49% of the female students had not previously had sex. Of those with sexual experience, 46% of the males and 23% of the females had had three or more sexual partners, and 32% of the males and 38% of the females did not consistently use condoms. For those who rated religion as less important in their family, the probability of early sexual activity and having had a high number of lifetime partners increased by a statistically significant amount (OR = 1.7; 95% CI: 1.2-2.4 and OR = 1.6; 95% CI: 1.1-2.3, respectively). However, the role of religion seemed to have no impact on condom use. Being of Protestant faith interacted with gender: among those who had debuted sexually, Protestant female students were more likely to have had three or more lifetime partners; the opposite was true for Protestant male students. CONCLUSION: Religion emerged as an important determinant of sexual behavior among Ugandan university students. Our findings correlate with the increasing number of conservative religious injunctions against premarital sex directed at young people in many countries with a high burden. of HIV/AIDS. Such influence of religion must be taken into account in order to gain a deeper understanding of the forces that shape sexual behavior in Uganda
The association between active participation in a sports club, physical activity and social network on the development of lung cancer in smokers: a case-control study
<p>Abstract</p> <p>Background</p> <p>This study analyses the effect of active participation in a sports club, physical activity and social networks on the development of lung cancer in patients who smoke. Our hypothesis is that study participants who lack social networks and do not actively participate in a sports club are at a greater risk for lung cancer than those who do.</p> <p>Methods</p> <p>Data for the study were taken from the <b>Co</b>logne <b>Smo</b>king <b>S</b>tudy (<b>CoSmoS</b>), a retrospective case-control study examining potential psychosocial risk factors for the development of lung cancer. Our sample consisted of n = 158 participants who had suffered lung cancer (diagnosis in the patient document) and n = 144 control group participants. Both groups had a history of smoking.</p> <p>Data on social networks were collected by asking participants whether they participated in a sports club and about the number of friends and relatives in their social environment. In addition, sociodemographic data (gender, age, education, marital status, residence and religion), physical activity and data on pack years (the cumulative number of cigarettes smoked by an individual, calculated by multiplying the number of cigarettes smoked per day by the number of years the person has smoked divided by 20) were collected to control for potential confounders. Logistic regression was used for the statistical analysis.</p> <p>Results</p> <p>The results reveal that participants who are physically active are at a lower risk of lung cancer than those who are not (adjusted OR = 0.53*; CI = 0.29-0.97). Older age and lower education seem also to be risk factors for the development of lung cancer. The extent of smoking, furthermore, measured by pack years is statistically significant. Active participation in a sports club, number of friends and relatives had no statistically significant influence on the development of the cancer.</p> <p>Conclusions</p> <p>The results of the study suggest that there is a lower risk for physically active participants to develop lung cancer. In the study sample, physical activity seemed to have a greater protective effect than participation in a sports club or social network of friends and relatives. Further studies have to investigate in more detail physical activity and other club participations.</p
Knowledge of obstetric danger signs and birth preparedness practices among women in rural Uganda
<p>Abstract</p> <p>Background</p> <p>Improving knowledge of obstetric danger signs and promoting birth preparedness practices are strategies aimed at enhancing utilization of skilled care in low-income countries. The aim of the study was to explore the association between knowledge of obstetric danger signs and birth preparedness among recently delivered women in south-western Uganda.</p> <p>Methods</p> <p>The study included 764 recently delivered women from 112 villages in Mbarara district. Community survey methods were used and 764 recently delivered women from 112 villages in Mbarara district were included in study. Interviewer administered questionnaire were used to collect data. Logistic regression analyses were conducted to explore the relationship between knowledge of key danger signs and birth preparedness.</p> <p>Results</p> <p>Fifty two percent of women knew at least one key danger sign during pregnancy, 72% during delivery and 72% during postpartum. Only 19% had knowledge of 3 or more key danger signs during the three periods. Of the four birth preparedness practices; 91% had saved money, 71% had bought birth materials, 61% identified a health professional and 61% identified means of transport. Overall 35% of the respondents were birth prepared. The relationship between knowledge of at least one key danger sign during pregnancy or during postpartum and birth preparedness showed statistical significance which persisted after adjusting for probable confounders (OR 1.8, 95% CI: 1.2-2.6) and (OR 1.9, 95% CI: 1.2-3.0) respectively. Young age and high levels of education had synergistic effect on the relationship between knowledge and birth preparedness. The associations between knowledge of at least one key danger sign during childbirth or knowledge that prolonged labour was a key danger sign and birth preparedness were not statistically significant.</p> <p>Conclusions</p> <p>The prevalence of recently delivered women who had knowledge of key danger signs or those who were birth prepared was very low. Since the majority of women attend antenatal care sessions, the quality and methods of delivery of antenatal care education require review so as to improve its effectiveness. Universal primary and secondary education programmes ought to be promoted so as to enhance the impact of knowledge of key danger signs on birth preparedness practices.</p
The Synaptonemal Complex Protein Zip1 Promotes Bi-Orientation of Centromeres at Meiosis I
In meiosis I, homologous chromosomes become paired and then separate from one another to opposite poles of the spindle. In humans, errors in this process are a leading cause of birth defects, mental retardation, and infertility. In most organisms, crossing-over, or exchange, between the homologous partners provides a link that promotes their proper, bipolar, attachment to the spindle. Attachment of both partners to the same pole can sometimes be corrected during a delay that is triggered by the spindle checkpoint. Studies of non-exchange chromosomes have shown that centromere pairing serves as an alternative to exchange by orienting the centromeres for proper microtubule attachment. Here, we demonstrate a new role for the synaptonemal complex protein Zip1. Zip1 localizes to the centromeres of non-exchange chromosomes in pachytene and mediates centromere pairing and segregation of the partners at meiosis I. Exchange chromosomes were also found to experience Zip1-dependent pairing at their centromeres. Zip1 was found to persist at centromeres, after synaptonemal complex disassembly, remaining there until microtubule attachment. Disruption of this centromere pairing, in spindle checkpoint mutants, randomized the segregation of exchange chromosomes. These results demonstrate that Zip1-mediated pairing of exchange chromosome centromeres promotes an initial, bipolar attachment of microtubules. This activity of Zip1 lessens the load on the spindle checkpoint, greatly reducing the chance that the cell will exit the checkpoint delay with an improperly oriented chromosome pair. Thus exchange, the spindle checkpoint, and centromere pairing are complementary mechanisms that ensure the proper segregation of homologous partners at meiosis I
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