5,725 research outputs found
Effects of reproductive and demographic changes on breast cancer incidence in China: A modeling analysis
Background: Breast cancer incidence is currently low in China. However, the distribution of reproductive and lifestyle risk factors for breast cancer among Chinese women is changing rapidly. We quantified the expected effect of changes in breast cancer risk factors on future rates of breast cancer in China.
Methods: We first validated and calibrated the Rosner-Colditz log-incidence breast cancer model in Chinese women who participated in the Shanghai Women's Health Study cohort (N = 74 942). We then applied the calibrated model to a representative sample of Chinese women who were aged 35-49 years in 2001 using data from the Chinese National Family Planning and Reproductive Health Survey (NFPRHS, N = 17 078) to predict the age-specific and cumulative breast cancer incidence among all Chinese women of this age group. We evaluated the relative impact of changes in modifiable risk factors, including alcohol intake, parity, postmenopausal hormone use, and adult weight gain, on cumulative incidence of breast cancer.
Results: Breast cancer incidence in China is expected to increase substantially from current rates, estimated at 10-60 cases per 100 000 women, to more than 100 new cases per 100 000 women aged 55-69 years by 2021. We predicted 2.5 million cases of breast cancer by 2021 among Chinese women who were 35-49 years old in 2001. Modest reductions in hormone and alcohol use, and weight maintenance could prevent 270 000 of these cases.
Conclusions: China is on the cusp of a breast cancer epidemic. Although some risk factors associated with economic development are largely unavoidable, the substantial predicted increase in new cases of breast cancer calls for urgent incorporation of this disease in future health care infrastructure planning
Inter-individual variation in nucleotide excision repair in young adults: effects of age, adiposity, micronutrient supplementation and genotype
Nucleotide excision repair (NER) is responsible for repairing bulky helix-distorting DNA lesions and is essential for the maintenance of genomic integrity. Severe hereditary impairment of NER leads to cancers such as those in xeroderma pigmentosum, and more moderate reductions in NER capacity have been associated with an increased cancer risk. Diet is a proven modifier of cancer risk but few studies have investigated the potential relationships between diet and NER. In the present study, the plasmid-based host cell reactivation assay was used to measure the NER capacity in peripheral blood mononuclear cells from fifty-seven volunteers aged 18–30 years before and after 6 weeks of supplementation with micronutrients (selenium and vitamins A, C and E). As a control, nine individuals remained unsupplemented over the same period. Volunteers were genotyped for the following polymorphisms in NER genes: ERCC5 Asp1104His (rs17655); XPC Lys939Gln (rs2228001); ERCC2 Lys751Gnl (rs13181); XPC PAT (an 83 bp poly A/T insertion–deletion polymorphism in the XPC gene). NER capacity varied 11-fold between individuals and was inversely associated with age and endogenous DNA strand breaks. For the first time, we observed an inverse association between adiposity and NER. No single polymorphism was associated with the NER capacity, although significant gene–gene interactions were observed between XPC Lys939Gln and ERCC5 Asp1104His and XPC Lys939Gln and ERCC2 Lys751Gnl. While there was no detectable effect of micronutrient supplementation on NER capacity, there was evidence that the effect of fruit intake on the NER capacity may be modulated by the ERCC2 Lys751Gnl single nucleotide polymorphism
How does perceived risk mediate associations between perceived safety and parental restriction of adolescents\u27 physical activity in their neighborhood?
BackgroundThere is evidence that adolescence is a critical period of decline in physical activity. However, adolescents may have limited opportunities to be physically active outdoors if their parents are concerned about neighborhood safety and restrict their adolescent’s physical activity within their neighborhood. Pathways that lead to parental restriction of adolescents’ physical activity (constrained behavior) are under-researched. This study aimed to examine perceived risk as a potential mediator of associations between perceived safety/victimization and constrained behavior.MethodsCross-sectional study of adolescents (43% boys) aged 15–17 years (n = 270) in Melbourne, Australia. Parents reported perceived safety (road safety, incivilities and personal safety) and prior victimization in their neighborhood, perceived risk of their children being harmed and whether they constrained their adolescent’s physical activity. Constrained behavior was categorized as ‘avoidance’ or ‘defensive’ behavior depending on a whether physical activity was avoided or modified, respectively, due to perceived risk. MacKinnon’s product-of-coefficients test of mediation was used to assess potential mediating pathways between perceived safety/victimization and constrained behavior.ResultsFor girls only, perceived risk was a significant mediator of associations between perceived road safety and avoidance/defensive behavior, and between perceived incivilities, perceived personal safety, victimization and defensive behavior.ConclusionsAssociations between perceived safety/victimization and constrained behavior are complex. Findings may guide the design of interventions that aim to improve actual and perceived levels of safety and reduce perceptions of risk. This is of particular importance for adolescent girls among whom low and declining levels of physical activity have been observed worldwide.<br /
The use and application of knowledge in practice : the lived experiences of social workers in adult services
This purpose of this study is to explore the lived experiences of social workers in adult social services in the United Kingdom, as they use and apply knowledge in practice. This is situated within the wider debate as to what might comprise the knowledge base for practice, how practitioners use knowledge and the issues they face in its application to practice. In some ways, this relationship between knowledge and practice lies at the very core of social work itself and it can be argued that it is this which makes it distinctive. Many writers continue to acknowledge the ‘theory/practice dichotomy’, which can be considered as an unacceptable gap, a disjuncture between what is taught or learned and what is practiced. Knowledge is seen as the domain of the academic and practice of the social worker. Much of the work in this area highlights the views and opinions of academics with little attention given to the experiences of practitioners who remain a relatively under-researched professional group. This qualitative study using Interpretative Phenomenological Analysis (IPA) presents an in-depth, idiographic analysis of the lived experiences of social workers in the adult field who discussed their experiences of the use and development of knowledge in their practice. Findings offer insights into what the social workers experienced as challenging, from both the increased complexity and pace of their workload with efforts to understand and intervene in the lives of their service users. The essence of the experience was condensed into three superordinate themes which emerged from the data; A Complex Process.The Use of Knowledge/Functionality.‘Putting it into Practice’.Detailing different aspects of the social workers’ experiences, the themes highlighted the complexity of impressions of the nature and type of knowledge used in practice, the various ways in which knowledge is used and the struggles to articulate and find a language to explain the issues faced in applying knowledge. As no previous study has considered the use and application of knowledge by practitioners in the adult sector in this way, the research findings provide new insights by hearing the voices of the participants enabling them to convey their understanding of what they perceive are the issues facing them in this important area of their practice
Deductive synthesis of recursive plans in linear logic
Linear logic has previously been shown to be suitable for describing and deductively solving planning problems involving conjunction and disjunction. We introduce a recursively defined datatype and a corresponding induction rule, thereby allowing recursive plans to be synthesised. In order to make explicit the relationship between proofs and plans, we enhance the linear logic deduction rules to handle plans as a form of proof term
Mediators of improved child diet quality following a health promotion intervention: the Melbourne InFANT program
BACKGROUND: Young children’s diets are currently suboptimal. Given that mothers have a critical influence on children’ diets, they are typically a target of interventions to improve early childhood nutrition. Understanding the maternal factors which mediate an intervention’s effect on young children’s diets is important, but has not been well investigated. This research aimed to test whether maternal feeding knowledge, maternal feeding practices, maternal self-efficacy, and maternal dietary intakes acted as mediators of the effect of an intervention to improve child diet quality. METHODS: The Melbourne Infant Feeding Activity and Nutrition Trial (InFANT) Program was a cluster-randomized controlled trial, conducted from 2008–2010. This novel, low-dose, health promotion intervention was delivered quarterly over 15 months and involved educational activities, promotion of peer discussion, a DVD and written materials. Post-intervention, when children were approximately 18 months of age, child diets were assessed using multiple 24-hour recalls and a purpose-developed index of diet quality, the Obesity Protective Dietary Index. Maternal mediators were assessed using a combination of previously validated and purpose-deigned tools. Mediation analysis was conducted using the test of joint significance and difference of coefficients methods. RESULTS: Across 62 parents’ groups in Melbourne, Australia, 542 parents were recruited. Post- intervention, higher maternal feeding knowledge and lower use of foods as rewards was found to mediate the direct intervention effect on child diet quality. While other aspects of maternal feeding practices, self-efficacy and dietary intakes did not act as mediators, they were associated with child diet quality. CONCLUSIONS: Mediation analysis of this novel health promotion intervention showed the importance of maternal feeding knowledge and use of foods as rewards in impacting child diet quality. The other maternal factors assessed were appropriate targets but further research on how to impact these in an intervention is important. This evidence of intervention efficacy and mediation provides important insights for planning future interventions. TRIAL REGISTRATION: Current Controlled Trials ISRCTN81847050, registered 23 November 2007. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12966-014-0137-5) contains supplementary material, which is available to authorized users
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