320 research outputs found
Knots and Particles
Using methods of high performance computing, we have found indications that
knotlike structures appear as stable finite energy solitons in a realistic 3+1
dimensional model. We have explicitly simulated the unknot and trefoil
configurations, and our results suggest that all torus knots appear as
solitons. Our observations open new theoretical possibilities in scenarios
where stringlike structures appear, including physics of fundamental
interactions and early universe cosmology. In nematic liquid crystals and 3He
superfluids such knotted solitons might actually be observed.Comment: 9 pages, 4 color eps figures and one b/w because of size limit (color
version available from authors
Recent ASA presidents and ‘top’ journals: observed publication patterns, alleged cartels and varying careers
It has been common for studies presented as about American sociology as a whole to rely on data compiled from leading journals (American Sociological Review [ASR] and American Journal of Sociology [AJS]), or about presidents of the American Sociological Association [ASA], to represent it. Clearly those are important, but neither can be regarded as providing a representative sample of American sociology. Recently, Stephen Turner has suggested that dominance in the ASA rests with a ‘cartel’ initially formed in graduate school, and that it favors work in a style associated with the leading journals. The adequacy of these ideas is examined in the light of available data on the last 20 years, which show that very few of the presidents were in the same graduate schools at the same time. All presidents have had distinguished academic records, but it is shown that their publication strategies have varied considerably. Some have had no ASR publications except their presidential addresses, while books and large numbers of other journals not normally mentioned in this context have figured in their contributions, as well as being more prominent in citations. It seems clear that articles in the leading journals have not been as closely tied to prestigious careers as has sometimes been suggested, and that if there is a cartel it has not included all the presidents
Factors associated with educational aspirations among adolescents: cues to counteract socioeconomic differences?
Background: Our study aims to follow this effort and to explore the association between health, socioeconomic background, school-related factors, social support and adolescents' sense of coherence and educational aspirations among adolescents from different educational tracks and to contribute to the existing body of knowledge on the role of educational aspirations in the social reproduction of health inequalities. We expect that socioeconomic background will contribute to the development of educational aspirations, but this association will be modified by available social and individual resources, which may be particularly favourable for the group of adolescents who are on lower educational tracks, since for them such resources may lead to gaining a higher educational level. Methods: We collected data on the socioeconomic background (mother's and father's education and employment status, doubts about affordability of future study), school-related factors (school atmosphere, school conditions, attitudes towards school), perceived social support, sense of coherence (manageability, comprehensibility, meaningfulness) and the self-rated health of a national sample of Slovak adolescents (n = 1992, 53.5% females, mean age 16.9 years). We assessed the association of these factors with educational aspirations, overall and by educational tracks (grammar schools, specialised secondary schools, vocational schools). Results: We found statistically significant associations with educational aspirations for the factors parental educational level, father's unemployment, doubts about the affordability of future study, school atmosphere, attitude towards school, social support from the father and a sense of coherence. Social support from the mother and friends was not associated with educational aspiration, nor was self-rated health. Besides affinity towards school, the determinants of educational aspirations differed among adolescents on different educational tracks. Educational aspirations of grammar school students were associated with father's education, while the aspirations of their peers on lower educational tracks had a stronger association with mother's education and perceived social support from father and friends. Moreover, a sense of coherence contributes to the reporting of educational aspiration by students on different educational tracks. Conclusions: Characteristics of the school environment, the family and the individual adolescent are all associated with the level of educational aspiration, but in a different way for different educational tracks. Interventions aimed at reducing socioeconomic inequalities in health via the educational system should, therefore, take this variation and the rather pivotal role of the father into account
Entrepreneurial sons, patriarchy and the Colonels' experiment in Thessaly, rural Greece
Existing studies within the field of institutional entrepreneurship explore how entrepreneurs influence change in economic institutions. This paper turns the attention of scholarly inquiry on the antecedents of deinstitutionalization and more specifically, the influence of entrepreneurship in shaping social institutions such as patriarchy. The paper draws from the findings of ethnographic work in two Greek lowland village communities during the military Dictatorship (1967–1974). Paradoxically this era associated with the spread of mechanization, cheap credit, revaluation of labour and clear means-ends relations, signalled entrepreneurial sons’ individuated dissent and activism who were now able to question the Patriarch’s authority, recognize opportunities and act as unintentional agents of deinstitutionalization. A ‘different’ model of institutional change is presented here, where politics intersects with entrepreneurs, in changing social institutions. This model discusses the external drivers of institutional atrophy and how handling dissensus (and its varieties over historical time) is instrumental in enabling institutional entrepreneurship
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‘Being Yourself’ in the Electronic Sweatshop: New Forms of Normative Control
This article extends research about high-commitment management practices in tightly controlled work environments typified by the call centre. One promising research avenue suggests that normative management systems in such contexts, involving ‘fun’ exercises and culture programmes, etc., are more about distracting employee attention away from other, more taxing controls. This article develops such an approach by exploring the specific nature and conditions of such distraction. An empirical study of a call centre in which employees were encouraged to ‘just be themselves’ (in relation to lifestyle differences, sexuality, diverse identities, etc.) reveals how the distractions are partly informed by the dysfunctions of existing technical, bureaucratic and conventional cultural controls, all of which homogenize workers. Furthermore, the new regime not only serves to distract employees, but proves instrumental in capturing their sociality, energy and ‘authentic’ or ‘non-work’ personalities as emotional labour. At the same time, it gives rise to some contestation and less individualistic forms of authenticity. These outcomes have wider implications for our understanding of worker autonomy in and around hybrid control systems
Tumour-draining axillary lymph nodes in patients with large and locally advanced breast cancers undergoing neoadjuvant chemotherapy (NAC): the crucial contribution of immune cells (effector, regulatory) and cytokines (TH1, TH2) to immune-mediated tumour cell death induced by NAC
Background
The tumour microenvironment consists of malignant cells, stroma and immune cells. In women with large and locally advanced breast cancers (LLABCs) undergoing neoadjuvant chemotherapy (NAC), tumour-infiltrating lymphocytes (TILs), various subsets (effector, regulatory) and cytokines in the primary tumour play a key role in the induction of tumour cell death and a pathological complete response (pCR) with NAC. Their contribution to a pCR in nodal metastases, however, is poorly studied and was investigated.
Methods
Axillary lymph nodes (ALNs) (24 with and 9 without metastases) from women with LLABCs undergoing NAC were immunohistochemically assessed for TILs, T effector and regulatory cell subsets, NK cells and cytokine expression using labelled antibodies, employing established semi-quantitative methods. IBM SPSS statistical package (21v) was used. Non-parametric (paired and unpaired) statistical analyses were performed. Univariate and multivariate regression analyses were carried out to establish the prediction of a pCR and Spearman’s Correlation Coefficient was used to determine the correlation of immune cell infiltrates in ALN metastatic and primary breast tumours.
Results
In ALN metastases high levels of TILs, CD4+ and CD8+ T and CD56+ NK cells were significantly associated with pCRs.. Significantly higher levels of Tregs (FOXP3+, CTLA-4+) and CD56+ NK cells were documented in ALN metastases than in the corresponding primary breast tumours. CD8+ T and CD56+ NK cells showed a positive correlation between metastatic and primary tumours. A high % CD8+ and low % FOXP3+ T cells and high CD8+: FOXP3+ ratio in metastatic ALNs (tumour-free para-cortex) were associated with pCRs. Metastatic ALNs expressed high IL-10, low IL-2 and IFN-Ï’.
Conclusions
Our study has provided new data characterising the possible contribution of T effector and regulatory cells and NK cells and T helper1 and 2 cytokines to tumour cell death associated with NAC in ALNs
Distal end side-to-side anastomoses of sequential vein graft to small target coronary arteries improve intraoperative graft flow
The association of academic tracking to depressive symptoms among adolescents in three Caribbean countries
<p>Abstract</p> <p>Background</p> <p>Students who are tracked into low performing schools or classrooms that limit their life chances may report increased depressive symptoms. Limited research has been conducted on academic tracking and its association with depressive symptoms among high school students in the Caribbean. This project examines levels of depressive symptoms among tenth grade students tracked within and between high schools in Jamaica, St. Vincent and St. Kitts and Nevis.</p> <p>Methods</p> <p>Students enrolled in grade ten of the 2006/2007 academic year in Jamaica, St. Kitts and Nevis and St. Vincent were administered the Beck Depression Inventory II (BDI-II). In Jamaica and St. Vincent, academic tracking was operationalized using data provided by the local Ministries of Education. These Ministries ranked ordered schools according to students' performance on Caribbean school leaving examinations. In St. Kitts and Nevis tracking was operationalized by classroom assignments within schools whereby students were grouped into classrooms according to their levels of academic achievement. Multiple regression analyses were conducted to examine the relationships between academic tracking and BDI-II depression scores.</p> <p>Results</p> <p>A wide cross-section of 4<sup>th </sup>form students in each nation was sampled (n = 1738; 278 from Jamaica, 737 St. Kitts and Nevis, 716 from St. Vincent; 52% females, 46.2% males and 1.8% no gender reported; age 12 to 19 years, mean = 15.4 yrs, sd = .9 yr). Roughly half (53%) of the students reported some symptoms of depression with 19.2% reporting moderate and 10.7% reporting severe symptoms of depression. Students in Jamaica reported significantly higher depression scores than those in either St. Kitts and Nevis or St. Vincent (p < .01). Students assigned to a higher academic track reported significantly lower BDI-II scores than students who were assigned to the lower academic track (p < .01).</p> <p>Conclusions</p> <p>There appears to be an association between academic tracking and depressive symptoms that is differentially manifested across the islands of Jamaica, St. Kitts and Nevis and St. Vincent.</p
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