51 research outputs found

    The Self-Linking Number in Annulus and Pants Open Book Decompositions

    Full text link
    We find a self-linking number formula for a given null-homologous transverse link in a contact manifold that is compatible with either an annulus or a pair of pants open book decomposition. It extends Bennequin's self-linking formula for a braid in the standard contact 33-sphere.Comment: 28 pages, 27 figure

    A MCP1 fusokine with CCR2-specific tumoricidal activity

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>The CCL2 chemokine is involved in promoting cancer angiogenesis, proliferation and metastasis by malignancies that express CCR2 receptor. Thus the CCL2/CCR2 axis is an attractive molecular target for anticancer drug development.</p> <p>Methods</p> <p>We have generated a novel fusion protein using GMCSF and an N-terminal truncated version of MCP1/CCL2 (6-76) [hereafter GMME1] and investigated its utility as a CCR2-specific tumoricidal agent.</p> <p>Results</p> <p>We found that distinct to full length CCL2 or its N-truncated derivative (CCL2 5-76), GMME1 bound to CCR2 on mouse lymphoma EG7, human multiple myeloma cell line U266, or murine and human medulloblastoma cell lines, and led to their death by apoptosis. We demonstrated that GMME1 specifically blocked CCR2-associated STAT3 phosphorylation and up-regulated pro-apoptotic BAX. Furthermore, GMME1 significantly inhibited EG7 tumor growth in C57BL/6 mice, and induced apoptosis of primary myeloma cells from patients.</p> <p>Conclusion</p> <p>Our data demonstrate that GMME1 is a fusokine with a potent, CCR2 receptor-mediated pro-apoptotic effect on tumor cells and could be exploited as a novel biological therapy for CCR2<sup>+ </sup>malignancies including lymphoid and central nervous system malignancies.</p

    General Framework for the Behaviour of Continuously Observed Open Quantum Systems

    Get PDF
    We develop the general quantum stochastic approach to the description of quantum measurements continuous in time. The framework, that we introduce, encompasses the various particular models for continuous-time measurements condsidered previously in the physical and the mathematical literature.Comment: 30 pages, no figure

    The serotonergic central nervous system of the Drosophila larva: anatomy and behavioral function.

    Get PDF
    The Drosophila larva has turned into a particularly simple model system for studying the neuronal basis of innate behaviors and higher brain functions. Neuronal networks involved in olfaction, gustation, vision and learning and memory have been described during the last decade, often up to the single-cell level. Thus, most of these sensory networks are substantially defined, from the sensory level up to third-order neurons. This is especially true for the olfactory system of the larva. Given the wealth of genetic tools in Drosophila it is now possible to address the question how modulatory systems interfere with sensory systems and affect learning and memory. Here we focus on the serotonergic system that was shown to be involved in mammalian and insect sensory perception as well as learning and memory. Larval studies suggested that the serotonergic system is involved in the modulation of olfaction, feeding, vision and heart rate regulation. In a dual anatomical and behavioral approach we describe the basic anatomy of the larval serotonergic system, down to the single-cell level. In parallel, by expressing apoptosis-inducing genes during embryonic and larval development, we ablate most of the serotonergic neurons within the larval central nervous system. When testing these animals for naïve odor, sugar, salt and light perception, no profound phenotype was detectable; even appetitive and aversive learning was normal. Our results provide the first comprehensive description of the neuronal network of the larval serotonergic system. Moreover, they suggest that serotonin per se is not necessary for any of the behaviors tested. However, our data do not exclude that this system may modulate or fine-tune a wide set of behaviors, similar to its reported function in other insect species or in mammals. Based on our observations and the availability of a wide variety of genetic tools, this issue can now be addressed

    Risk of venous thromboembolism after total hip and knee replacement in older adults with comorbidity and co-occurring comorbidities in the Nationwide Inpatient Sample (2003-2006)

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Venous thromboembolism is a common, fatal, and costly injury which complicates major surgery in older adults. The American College of Chest Physicians recommends high potency prophylaxis regimens for individuals undergoing total hip or knee replacement (THR or TKR), but surgeons are reluctant to prescribe them due to fear of excess bleeding. Identifying a high risk cohort such as older adults with comorbidities and co-occurring comorbidities who might benefit most from high potency prophylaxis would improve how we currently perform preoperative assessment.</p> <p>Methods</p> <p>Using the Nationwide Inpatient Sample, we identified older adults who underwent THR or TKR in the U.S. between 2003 and 2006. Our outcome was VTE, including any pulmonary embolus or deep venous thrombosis. We performed multivariate logistic regression analyses to assess the effects of comorbidities on VTE occurrence. Comorbidities under consideration included coronary artery disease, congestive heart failure (CHF), chronic obstructive pulmonary disease (COPD), diabetes, and cerebrovascular disease. We also examined the impact of co-occurring comorbidities on VTE rates.</p> <p>Results</p> <p>CHF increased odds of VTE in both the THR cohort (OR = 3.08 95% CI 2.05-4.65) and TKR cohort (OR = 2.47 95% CI 1.95-3.14). COPD led to a 50% increase in odds in the TKR cohort (OR = 1.49 95% CI 1.31-1.70). The data did not support synergistic effect of co-occurring comorbidities with respect to VTE occurrence.</p> <p>Conclusions</p> <p>Older adults with CHF undergoing THR or TKR and with COPD undergoing TKR are at increased risk of VTE. If confirmed in other datasets, these older adults may benefit from higher potency prophylaxis.</p

    Immigrant students’ psychological adjustment in the school context: A meta-synthesis of qualitative research on acculturation

    No full text
    This contribution focuses on the characteristics of the school context and their impact on immigrant students’ acculturation and adjustment at school. Research suggests that the ways immigrants acculturate is related to their well being (e.g. Phinney, et al., 2001; Ward & Rana-Deuba, 1999), although findings have been contradictory across methods and studies (e.g. Rogler, 1991; Escobar & Vega, 2001). Debates in acculturation research currently center on issues of acculturation measurement (e.g. Berry, 2009; Rudmin, 2009), as most research is conducted in the quantitative tradition. In addition, some have suggested (Birman, 2011) that research on acculturation in the tradition of cross-cultural psychology adopts an overly individualistic perspective, and lacks attention to the specific contexts of acculturation. Alternatively, the contextual approach proposes that the relationship between acculturation and adjustment is shaped by the surrounding context (Birman & Simon, 2013). For immigrant children, schools are the setting where the process of acculturation unfolds, and an important context in which to study their adjustment and well being (Birman, et al., 2007; Makarova & Herzog, 2011). Though rarely used in this tradition of acculturation research (Chirkov, 2009), qualitative methods are uniquely suited to gain insight to facilitate theory development, as well as appreciate the contextual nature of the acculturation process. Yet we are not aware of efforts to synthesize the empirical qualitative literature on this topic. Applying the methodology of meta-synthesis for qualitatieve research (Walsh & Downe, 2005) our contribution attempts to integrate results from qualitative studies on impact of acculturation on immigrant students’ psychological adjustment in the school context. For this purpose 84 articles which matched the inclusion criteria were selected. Overall, the results of our study show that within the school context a number of structural as well as process characteristics can be identified as crucial for immigrant youth psychological adjustment. Moreover, our findings indicate that immigrant youths’ psychological adjustment is related to other individual outcomes of acculturation in the school context such as behavioral adjustment, peer-relationships, academic achievement and identity development of immigrant youth

    Minority students' psychological adjustment in the school context: An integrative review of qualitative research on acculturation

    No full text
    The present study aims at systematically analyzing the fi ndings reported in qualitative research on acculturation and psychological adjustment in the school context. Content analysis was conducted using the deductively developed and inductively enriched system of categories. The results of the study provide insights into youths ' acculturation and their psychological adjustment in the school context as well as schools ' mechanisms and strategies for responding to minority youths ' needs in the process of the cultural transition

    Cultural transition and academic achievement of students from ethnic minority backgrounds: A content analysis of empirical research on acculturation

    No full text
    Background: The achievement gap between immigrant and non-immigrant students that has been identi fi ed in most OECD countries and the considerable educational dropout rate among students from ethnic minority backgrounds in some countries have become serious challenges for national educational systems. The educational underachievement of young people from ethnic minority backgrounds is embedded in the process of their acculturation. In the tradition of cross-cultural psychology, acculturation describes individual or ethno-cultural group changes in behaviour and attitudes in the situation of intercultural contact. Such cultural changes are central to the experience of ethnic minority students including newly arriving immigrants, chil- dren of immigrants and members of marginalised ethnic and racial groups. Acculturation has been described as a stressful process, and acculturation orientations adopted by young people from ethnic minority backgrounds have been shown to have an impact on their adjustment. Purpose: The school context has been recognised to be the crucial context for acculturation of young people from ethnic minority backgrounds. The academic achievement of these students is thus embedded in the acculturation process, which involves cultural identity development, psychological adjustment and behavioural adjustment. The study is aimed at analysing and systematising the fi ndings of empiri- cal research on acculturation in the school context with a focus on the academic achievement of young people from minority backgrounds. Design and methods: For this study, 29 peer-reviewed articles from a total of 348 articles that matched the search criteria in the database of the Education Resources Information Centre were selected according to inclusion criteria. The selected articles addressed academic achievement of young people from minority backgrounds in rela- tion to at least one of the issues of acculturation such as cultural identity, psychologi- cal adjustment and behavioural adjustment. The articles were analysed by applying the method of qualitative content analysis, using MAXQDA software. The fi ndings presented in the selected articles were analysed and integrated according to a deduc- tively developed and inductively enriched category system. Conclusions: Overall, the results of our analysis offer insight into issues of accultura- tion in relation to academic achievement. Moreover, our fi ndings reveal the complex- ity of the relationship between cultural transition and school adjustment for young people. As shown in our review, although a bi-cultural orientation was predominantly positively related to school adjustment of minority students, some studies also identi fi ed assimilative attitudes as advantageous for students ' academic achievement as well as for their psychological and behavioural adjustment. Moreover, our study has also shown that young people ' s acculturative attitudes may have a different impact on their school adjustment relative to acculturative behaviours
    corecore