987 resultados para correlated binary regression


Relevância:

20.00% 20.00%

Publicador:

Resumo:

This paper presents a combined structure for using real, complex, and binary valued vectors for semantic representation. The theory, implementation, and application of this structure are all significant. For the theory underlying quantum interaction, it is important to develop a core set of mathematical operators that describe systems of information, just as core mathematical operators in quantum mechanics are used to describe the behavior of physical systems. The system described in this paper enables us to compare more traditional quantum mechanical models (which use complex state vectors), alongside more generalized quantum models that use real and binary vectors. The implementation of such a system presents fundamental computational challenges. For large and sometimes sparse datasets, the demands on time and space are different for real, complex, and binary vectors. To accommodate these demands, the Semantic Vectors package has been carefully adapted and can now switch between different number types comparatively seamlessly. This paper describes the key abstract operations in our semantic vector models, and describes the implementations for real, complex, and binary vectors. We also discuss some of the key questions that arise in the field of quantum interaction and informatics, explaining how the wide availability of modelling options for different number fields will help to investigate some of these questions.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Aims: This study investigated the association between the basal (rest) insulin-signaling proteins, Akt, and the Akt substrate AS160, metabolic risk factors, inflammatory markers and aerobic fitness, in middle-aged women with varying numbers of metabolic risk factors for type 2 diabetes. Methods: Sixteen women (n = 16) aged 51.3+/-5.1 (mean +/-SD) years provided muscle biopsies and blood samples at rest. In addition, anthropometric characteristics and aerobic power were assessed and the number of metabolic risk factors for each participant was determined (IDF criteria). Results: The mean number of metabolic risk factors was 1.6+/-1.2. Total Akt was negatively correlated with IL-1 beta (r = -0.45, p = 0.046), IL-6 (r = -0.44, p = 0.052) and TNF-alpha (r = -0.51, p = 0.025). Phosphorylated AS160 was positively correlated with HDL (r = 0.58, p = 0.024) and aerobic fitness (r = 0.51, p = 0.047). Furthermore, a multiple regression analysis revealed that both HDL (t = 2.5, p = 0.032) and VO(2peak) (t = 2.4, p = 0.037) were better predictors for phosphorylated AS160 than TNF-alpha or IL-6 (p>0.05). Conclusions: Elevated inflammatory markers and increased metabolic risk factors may inhibit insulin-signaling protein phosphorylation in middle-aged women, thereby increasing insulin resistance under basal conditions. Furthermore, higher HDL and fitness levels are associated with an increased AS160 phosphorylation, which may in turn reduce insulin resistance.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

There is overwhelming evidence that persistent infection with high-risk human papillomaviruses (HR-HPV) is the main risk factor for invasive cancer of the cervix. Due to this global public health burden, two prophylactic HPV L1 virus-like particles (VLP) vaccines have been developed. While these vaccines have demonstrated excellent type-specific prevention of infection by the homologous vaccine types (high and low risk HPV types), no data have been reported on the therapeutic effects in people already infected with the low-risk HPV type. In this study we explored whether regression of CRPV-induced papillomas could be achieved following immunisation of out-bred New Zealand White rabbits with CRPV VLPs. Rabbits immunised with CRPV VLPs had papillomas that were significantly smaller compared to the negative control rabbit group (P ≤ 0.05). This data demonstrates the therapeutic potential of PV VLPs in a well-understood animal model with potential important implications for human therapeutic vaccination for low-risk HPVs. © 2008 Govan et al; licensee BioMed Central Ltd.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Androgen-dependent pathways regulate maintenance and growth of normal and malignant prostate tissues. Androgen deprivation therapy (ADT) exploits this dependence and is used to treat metastatic prostate cancer; however, regression initially seen with ADT gives way to development of incurable castration-resistant prostate cancer (CRPC). Although ADT generates a therapeutic response, it is also associated with a pattern of metabolic alterations consistent with metabolic syndrome including elevated circulating insulin. Because CRPC cells are capable of synthesizing androgens de novo, we hypothesized that insulin may also influence steroidogenesis in CRPC. In this study, we examined this hypothesis by evaluating the effect of insulin on steroid synthesis in prostate cancer cell lines. Treatment with 10 nmol/L insulin increased mRNA and protein expression of steroidogenesis enzymes and upregulated the insulin receptor substrate insulin receptor substrate 2 (IRS-2). Similarly, insulin treatment upregulated intracellular testosterone levels and secreted androgens, with the concentrations of steroids observed similar to the levels reported in prostate cancer patients. With similar potency to dihydrotestosterone, insulin treatment resulted in increased mRNA expression of prostate-specific antigen. CRPC progression also correlated with increased expression of IRS-2 and insulin receptor in vivo. Taken together, our findings support the hypothesis that the elevated insulin levels associated with therapeutic castration may exacerbate progression of prostate cancer to incurable CRPC in part by enhancing steroidogenesis.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Objectives: This study examines the hypothesis that a past history of heart interventions will moderate the relationship between psychosocial factors (stressful life events, social support, perceived stress, having a current partner, having a past diagnosis of depression or anxiety over the past 3 years, time pressure, education level, and the mental health index) and the presence of chest pain in a sample of older women. Design: Longitudinal survey over a 3-year period. Methods: The sample was taken from a prospective cohort study of 10,432 women initially aged between 70 and 75 years, who were surveyed in 1996 and then again in 1999. Two groups of women were identified: those reporting to have heart disease but no past history of heart interventions (i.e., coronary artery bypass graft/angioplasty) and those reporting to have heart disease with a past history of heart interventions. Results: Binary logistic regression analysis was used to show that for the women with self-reported coronary heart disease but without a past history of heart intervention, feelings of time pressure as well as the number of stressful life events experienced in the 12 months prior to 1996 were independent risk factors for the presence of chest pain, even after accounting for a range of traditional risk factors. In comparison, for the women with self-reported coronary heart disease who did report a past history of heart interventions, a diagnosis of depression in the previous 3 years was the significant independent risk factor for chest pain even after accounting for traditional risk factors. Conclusion: The results indicate that it is important to consider a history of heart interventions as a moderator of the associations between psychosocial variables and the frequency of chest pain in older women. Statement of Contribution: What is already known on this subject? Psychological factors have been shown to be independent predictors of a range of health outcomes in individuals with coronary heart disease, including the presence of chest pain. Most research has been conducted with men or with small samples of women; however, the evidence does suggest that these relationships exist in women as well as in men. What does this study add? Most studies have looked at overall relationships between psychological variables and health outcomes. The few studies that have looked at moderators have mainly examined gender as a moderator. To our knowledge, this is the first published study to examine a history of heart interventions as a moderator of the relationship between psychological variables and the presence of chest pain.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This research identifies residential mobility behaviour impacts of residential dissonance in Transit Oriented Developments (TODs) vs. non-TODs in Brisbane, Australia. Based on the characteristics of living environments (density, diversity, connectivity, and accessibility) and the travel preferences of 4545 individuals, respondents in 2009 were classified into one of four categories including: TOD consonants, TOD dissonants, non-TOD dissonants, and non-TOD consonants. Binary logistic regression analyses were employed to identify residential mobility behaviour of groups between 2009 and 2011; controlling for time varying covariates. The findings show that both TOD dissonants and TOD consonants move residences at an equal rate. However, TOD dissonants are more likely to move residences to their preferred non-TOD areas. In contrast, non-TOD dissonants not only moved residences at a lower rate, but their rate of mobility to their preferred TOD neighbourhood is also significantly lower due to costs and other associated factors. The findings suggest that discrete land use policy development is required to integrate non-TOD dissonant and TOD dissonant behaviours to support TOD development in Brisbane.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Dhaka, which is the capital of Bangladesh, is facing serious traffic congestion and whole traffic situation in Dhaka is in chaos. Government has initiated some projects; such as BRT, MRT and elevated expressway; to improve the situation. Road pricing is very popular concept, which can be implemented in Dhaka with BRT and MRT as an integrated manner. Even though it is very popular concept not many countries except some developed countries implemented road pricing practically. None of the developing countries adopted this policy. For success of road pricing it has to be acceptable among the stakeholders. Public are the main stakeholders for road pricing. This paper will explore whether road pricing will be acceptable in Dhaka considering only work trip in Dhaka. A sample of workers had been surveyed randomly. They were asked some demographic questions, such as age, gender, income and educational qualification; how they travelled to work; and whether they would accept road pricing; and if they would not accept road pricing the reasons behind that. Also respondents were given several hypothetical choices to see how respondents react with different road charge by choosing travel mode for their work trip. The methodological approach taken for analysis is qualitative and quantitative analysis. For quantitative analysis Binary Logit Regression analysis was carried out to find out the significant factors for accepting or not accepting road pricing.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Objective: To establish risk factors for moderate and severe microbial keratitis among daily contact lens (CL) wearers in Australia. Design: A prospective, 12-month, population-based, case-control study. Participants: New cases of moderate and severe microbial keratitis in daily wear CL users presenting in Australia over a 12-month period were identified through surveillance of all ophthalmic practitioners. Case detection was augmented by record audits at major ophthalmic centers. Controls were users of daily wear CLs in the community identified using a national telephone survey. Testing: Cases and controls were interviewed by telephone to determine subject demographics and CL wear history. Multiple binary logistic regression was used to determine independent risk factors and univariate population attributable risk percentage (PAR%) was estimated for each risk factor.; Main Outcome Measures: Independent risk factors, relative risk (with 95% confidence intervals [CIs]), and PAR%. Results: There were 90 eligible moderate and severe cases related to daily wear of CLs reported during the study period. We identified 1090 community controls using daily wear CLs. Independent risk factors for moderate and severe keratitis while adjusting for age, gender, and lens material type included poor storage case hygiene 6.4× (95% CI, 1.9-21.8; PAR, 49%), infrequent storage case replacement 5.4× (95% CI, 1.5-18.9; PAR, 27%), solution type 7.2× (95% CI, 2.3-22.5; PAR, 35%), occasional overnight lens use (<1 night per week) 6.5× (95% CI, 1.3-31.7; PAR, 23%), high socioeconomic status 4.1× (95% CI, 1.2-14.4; PAR, 31%), and smoking 3.7× (95% CI, 1.1-12.8; PAR, 31%). Conclusions: Moderate and severe microbial keratitis associated with daily use of CLs was independently associated with factors likely to cause contamination of CL storage cases (frequency of storage case replacement, hygiene, and solution type). Other factors included occasional overnight use of CLs, smoking, and socioeconomic class. Disease load may be considerably reduced by attention to modifiable risk factors related to CL storage case practice.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Background Non-fatal health outcomes from diseases and injuries are a crucial consideration in the promotion and monitoring of individual and population health. The Global Burden of Disease (GBD) studies done in 1990 and 2000 have been the only studies to quantify non-fatal health outcomes across an exhaustive set of disorders at the global and regional level. Neither effort quantified uncertainty in prevalence or years lived with disability (YLDs). Methods Of the 291 diseases and injuries in the GBD cause list, 289 cause disability. For 1160 sequelae of the 289 diseases and injuries, we undertook a systematic analysis of prevalence, incidence, remission, duration, and excess mortality. Sources included published studies, case notification, population-based cancer registries, other disease registries, antenatal clinic serosurveillance, hospital discharge data, ambulatory care data, household surveys, other surveys, and cohort studies. For most sequelae, we used a Bayesian meta-regression method, DisMod-MR, designed to address key limitations in descriptive epidemiological data, including missing data, inconsistency, and large methodological variation between data sources. For some disorders, we used natural history models, geospatial models, back-calculation models (models calculating incidence from population mortality rates and case fatality), or registration completeness models (models adjusting for incomplete registration with health-system access and other covariates). Disability weights for 220 unique health states were used to capture the severity of health loss. YLDs by cause at age, sex, country, and year levels were adjusted for comorbidity with simulation methods. We included uncertainty estimates at all stages of the analysis. Findings Global prevalence for all ages combined in 2010 across the 1160 sequelae ranged from fewer than one case per 1 million people to 350 000 cases per 1 million people. Prevalence and severity of health loss were weakly correlated (correlation coefficient −0·37). In 2010, there were 777 million YLDs from all causes, up from 583 million in 1990. The main contributors to global YLDs were mental and behavioural disorders, musculoskeletal disorders, and diabetes or endocrine diseases. The leading specific causes of YLDs were much the same in 2010 as they were in 1990: low back pain, major depressive disorder, iron-deficiency anaemia, neck pain, chronic obstructive pulmonary disease, anxiety disorders, migraine, diabetes, and falls. Age-specific prevalence of YLDs increased with age in all regions and has decreased slightly from 1990 to 2010. Regional patterns of the leading causes of YLDs were more similar compared with years of life lost due to premature mortality. Neglected tropical diseases, HIV/AIDS, tuberculosis, malaria, and anaemia were important causes of YLDs in sub-Saharan Africa. Interpretation Rates of YLDs per 100 000 people have remained largely constant over time but rise steadily with age. Population growth and ageing have increased YLD numbers and crude rates over the past two decades. Prevalences of the most common causes of YLDs, such as mental and behavioural disorders and musculoskeletal disorders, have not decreased. Health systems will need to address the needs of the rising numbers of individuals with a range of disorders that largely cause disability but not mortality. Quantification of the burden of non-fatal health outcomes will be crucial to understand how well health systems are responding to these challenges. Effective and affordable strategies to deal with this rising burden are an urgent priority for health systems in most parts of the world. Funding Bill & Melinda Gates Foundation.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Recent literature has argued that environmental efficiency (EE), which is built on the materials balance (MB) principle, is more suitable than other EE measures in situations where the law of mass conversation regulates production processes. In addition, the MB-based EE method is particularly useful in analysing possible trade-offs between cost and environmental performance. Identifying determinants of MB-based EE can provide useful information to decision makers but there are very few empirical investigations into this issue. This article proposes the use of data envelopment analysis and stochastic frontier analysis techniques to analyse variation in MB-based EE. Specifically, the article develops a stochastic nutrient frontier and nutrient inefficiency model to analyse determinants of MB-based EE. The empirical study applies both techniques to investigate MB-based EE of 96 rice farms in South Korea. The size of land, fertiliser consumption intensity, cost allocative efficiency, and the share of owned land out of total land are found to be correlated with MB-based EE. The results confirm the presence of a trade-off between MB-based EE and cost allocative efficiency and this finding, favouring policy interventions to help farms simultaneously achieve cost efficiency and MP-based EE.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

An optical system which performs the multiplication of binary numbers is described and proof-of-principle experiments are performed. The simultaneous generation of all partial products, optical regrouping of bit products, and optical carry look-ahead addition are novel features of the proposed scheme which takes advantage of the parallel operations capability of optical computers. The proposed processor uses liquid crystal light valves (LCLVs). By space-sharing the LCLVs one such system could function as an array of multipliers. Together with the optical carry look-ahead adders described, this would constitute an optical matrix-vector multiplier.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A satellite based observation system can continuously or repeatedly generate a user state vector time series that may contain useful information. One typical example is the collection of International GNSS Services (IGS) station daily and weekly combined solutions. Another example is the epoch-by-epoch kinematic position time series of a receiver derived by a GPS real time kinematic (RTK) technique. Although some multivariate analysis techniques have been adopted to assess the noise characteristics of multivariate state time series, statistic testings are limited to univariate time series. After review of frequently used hypotheses test statistics in univariate analysis of GNSS state time series, the paper presents a number of T-squared multivariate analysis statistics for use in the analysis of multivariate GNSS state time series. These T-squared test statistics have taken the correlation between coordinate components into account, which is neglected in univariate analysis. Numerical analysis was conducted with the multi-year time series of an IGS station to schematically demonstrate the results from the multivariate hypothesis testing in comparison with the univariate hypothesis testing results. The results have demonstrated that, in general, the testing for multivariate mean shifts and outliers tends to reject less data samples than the testing for univariate mean shifts and outliers under the same confidence level. It is noted that neither univariate nor multivariate data analysis methods are intended to replace physical analysis. Instead, these should be treated as complementary statistical methods for a prior or posteriori investigations. Physical analysis is necessary subsequently to refine and interpret the results.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Purpose: The purpose of the study was to examine relationships between socio-demographic variables, job satisfaction and nurses’ caring experiences in a registered nurse population, as measured by the caring efficacy scale (CES) which was developed from Bandura’s social cognitive theory and Watson’s transpersonal caring theory. Methods: A cross-sectional survey was undertaken of nurses representing a variety of nursing specialties. A stratified random sample of registered nurses, who were members of a professional nursing organisation, was invited to participate in this study. Descriptive analyses, correlation analyses, one- way ANOVA tests, simple linear regression and multivariable analyses were conducted to examine if any relationships existed between these variables. Results: There were a total of 639 respondents to the national survey. The respondents (100%) showed positive perceived CES scores and 80.8% showed positive job satisfaction scores. Correlation analysis found age, years experience as a registered nurse and years in current job, all positively correlated with each other, (r >0.40: p < 0.001). CES scores were found to be positively correlated with age, years of experience as a registered nurse (r>0.1: p < 0.001) and job satisfaction (r>0.1: p < 0.001). An ANOVA found significant positive relationships between CES scores and age (p=0.05). Conclusion: Results from this study have identified that relationships between age, years of experience, job satisfaction and the perceived caring experiences of nurses’ exist. Organisational leaders may develop strategies for professional development and orientation programmes that enhance the caring experiences of nurses to provide quality patient care. The development of programmes that provide role modelling, emotional support or use verbal persuasion are needed where encouragement is required for nurses to master new skills. This may also improve job satisfaction and retention of nurses in the workplace in the current economically focussed healthcare system.