A review of multi-component maintenance models with economic dependence

In this paper we review the literature on multi-component maintenance models with economic dependence. The emphasis is on papers that appeared after 1991, but there is an overlap with Section 2 of the most recent review paper by Cho and Parlar (1991). We distinguish between stationary models, where a long-term stable situation is assumed, and dynamic models, which can take information into account that becomes available only on the short term. Within the stationary models we choose a classification scheme that is primarily based on the various options of grouping maintenance activities: grouping either corrective or preventive maintenance, or combining preventive-maintenance actions with corrective actions. As such, this classification links up with the possibilities for grouped maintenance activities that exist in practice

Soy consumption and risk of COPD and respiratory symptoms: a case-control study in Japan

<p>Abstract</p> <p>Background</p> <p>To investigate the relationship between soy consumption, COPD risk and the prevalence of respiratory symptoms, a case-control study was conducted in Japan.</p> <p>Methods</p> <p>A total of 278 eligible patients (244 men and 34 women), aged 50–75 years with COPD diagnosed within the past four years, were referred by respiratory physicians, while 340 controls (272 men and 68 women) were recruited from the community. All participants underwent spirometric measurements of respiratory function. Information on demographics, lifestyle characteristics and habitual food consumption was obtained using a structured questionnaire.</p> <p>Results</p> <p>Total soy consumption was positively correlated with observed lung function measures. The mean soy intake was significantly higher among controls (59.98, SD 50.23 g/day) than cases (44.84, SD 28.5 g/day). A significant reduction in COPD risk was evident for highest versus lowest quartile of daily intake of total soybean products, with adjusted odds ratio (OR) 0.392, 95% CI 0.194–0.793, <it>p </it>for trend 0.001. Similar decreases in COPD risk were associated with frequent and higher intake of soy foods such as tofu and bean sprouts, whereas respiratory symptoms were inversely associated with high consumption of soy foods, especially for breathlessness (OR 0.989, 95% CI 0.982–0.996).</p> <p>Conclusion</p> <p>Increasing soy consumption was associated with a decreased risk of COPD and breathlessness.</p

The effectiveness of a health promotion with group intervention by clinical trial. Study protocol

<p>Abstract</p> <p>Background</p> <p>The promotion of health and the interventions in community health continue to be one of the pending subjects of our health system. The most prevalent health problems (cardiovascular diseases, cancer, diabetes...) are for the most part related to life habits. We propose a holistic and integral approach as the best option for tackling behavior and its determinants. The research team has elaborated the necessary educational material to realize group teaching, which we call "Health Workshops". The goal of the present study is to evaluate the effectiveness of these Health Workshops in the following terms: Health Related Quality of Life (HRQOL), incorporate and maintain a balanced diet, do physical activity regularly, maintain risk factors such as tension, weight, cholesterol within normal limits and diminish cardiovascular risk.</p> <p>Methods/Design</p> <p>Controlled and random clinical testing, comparing a group of persons who have participated in the Health Workshops with a control group of similar characteristics who have not participated in the Health Workshops.</p> <p>Field of study: the research is being done in Health Centers of the city of Barcelona, Spain.</p> <p>Population studied: The group is composed of 108 persons that are actually doing the Health Workshops, and 108 that are not and form the control group. They are assigned at random to one group or the other.</p> <p>Data Analysis: With Student's t-distribution test to compare the differences between numerical variables or their non parametric equivalent if the variable does not comply with the criteria of normality. (Kolmogorov-Smirnof test). Chi-square test to compare the differences between categorical variables and the Logistic Regression Model to analyze different meaningful variables by dichotomous analysis related to the intervention.</p> <p>Discussion</p> <p>The Health Workshop proposed in the present study constitutes an innovative approach in health promotion, placing the emphasis on the person's self responsibility for his/her own health.</p> <p>The rhythm of a weekly session during 8 weeks with recommended activities to put into practice, as well as the support of the group is an opportunity to incorporate healthy habits and make a commitment to self-care. The sheets handed out are a Health Manual that can always be consulted after the workshop ends.</p> <p>Trial registration</p> <p>Clinical Trials.gov Identifier: <a href="http://www.clinicaltrials.gov/ct2/show/NCT01440738">NCT01440738</a></p

Psychosocial correlates of dietary fat intake in African-American adults: a cross-sectional study

<p>Abstract</p> <p>Background</p> <p>Current dietary guidelines recommend that dietary fat should comprise 20–35% percent of total energy intake, with less than 10% of energy from saturated fat. However, many Americans exceed these goals and data suggest that African Americans tend to consume a higher percentage of energy from dietary fat than Whites. Because diets low in dietary fat, particularly saturated fat, are associated with lower risk for many chronic illnesses, it is important to identify strategies to reduce high fat intakes. This study examined associations of psychosocial factors with dietary fat intake in African American adults 18 to 70 years.</p> <p>Methods</p> <p>Data are self-reported from a cross-sectional survey of African Americans (n = 658) using an 11-page questionnaire, collected from June to October 2003. Associations of psychosocial (predisposing, reinforcing, and enabling) factors based on the PRECEDE framework, dietary fat-related behaviors, and participant characteristics (e.g., age, sex, education, BMI) with total and saturated fat consumption are described using linear regression and analysis of variance.</p> <p>Results</p> <p>The mean age of participants was 43.9 years, 57% were female, 37% were college graduates, and 76% were overweight/obese. Respondents with lower fat intakes were female, older, had high education and very good/excellent perceived health. Among the psychosocial factors, the strongest (inverse) associations with fat intake were with two predisposing factors: <it>belief in the importance of a low-fat diet </it>(both genders) and <it>high self-efficacy </it>(women only). Fat intake was also significantly lower among participants who could <it>count on those close for encouragement to eat healthy foods </it>(a reinforcing factor) and among men who <it>needed more information about preparing healthy foods </it>(an enabling factor).</p> <p>Conclusion</p> <p>Dietary interventions to decrease fat intake in African American adults may benefit from incorporating predisposing factors, such as personal beliefs and self-efficacy, in their design and implementation.</p

In vivo magnetic resonance spectroscopy: basic methodology and clinical applications

The clinical use of in vivo magnetic resonance spectroscopy (MRS) has been limited for a long time, mainly due to its low sensitivity. However, with the advent of clinical MR systems with higher magnetic field strengths such as 3 Tesla, the development of better coils, and the design of optimized radio-frequency pulses, sensitivity has been considerably improved. Therefore, in vivo MRS has become a technique that is routinely used more and more in the clinic. In this review, the basic methodology of in vivo MRS is described—mainly focused on 1H MRS of the brain—with attention to hardware requirements, patient safety, acquisition methods, data post-processing, and quantification. Furthermore, examples of clinical applications of in vivo brain MRS in two interesting fields are described. First, together with a description of the major resonances present in brain MR spectra, several examples are presented of deviations from the normal spectral pattern associated with inborn errors of metabolism. Second, through examples of MR spectra of brain tumors, it is shown that MRS can play an important role in oncology

Addressing Cancer Disparities via Community Network Mobilization and Intersectoral Partnerships: A Social Network Analysis

Community mobilization and collaboration among diverse partners are vital components of the effort to reduce and eliminate cancer disparities in the United States. We studied the development and impact of intersectoral connections among the members of the Massachusetts Community Network for Cancer Education, Research, and Training (MassCONECT). As one of the Community Network Program sites funded by the National Cancer Institute, this infrastructure-building initiative utilized principles of Community-based Participatory Research (CBPR) to unite community coalitions, researchers, policymakers, and other important stakeholders to address cancer disparities in three Massachusetts communities: Boston, Lawrence, and Worcester. We conducted a cross-sectional, sociometric network analysis four years after the network was formed. A total of 38 of 55 members participated in the study (69% response rate). Over four years of collaboration, the number of intersectoral connections reported by members (intersectoral out-degree) increased, as did the extent to which such connections were reported reciprocally (intersectoral reciprocity). We assessed relationships between these markers of intersectoral collaboration and three intermediate outcomes in the effort to reduce and eliminate cancer disparities: delivery of community activities, policy engagement, and grants/publications. We found a positive and statistically significant relationship between intersectoral out-degree and community activities and policy engagement (the relationship was borderline significant for grants/publications). We found a positive and statistically significant relationship between intersectoral reciprocity and community activities and grants/publications (the relationship was borderline significant for policy engagement). The study suggests that intersectoral connections may be important drivers of diverse intermediate outcomes in the effort to reduce and eliminate cancer disparities. The findings support investment in infrastructure-building and intersectoral mobilization in addressing disparities and highlight the benefits of using CBPR approaches for such work

Multishot versus Single-Shot Pulse Sequences in Very High Field fMRI: A Comparison Using Retinotopic Mapping

High-resolution functional MRI is a leading application for very high field (7 Tesla) human MR imaging. Though higher field strengths promise improvements in signal-to-noise ratios (SNR) and BOLD contrast relative to fMRI at 3 Tesla, these benefits may be partially offset by accompanying increases in geometric distortion and other off-resonance effects. Such effects may be especially pronounced with the single-shot EPI pulse sequences typically used for fMRI at standard field strengths. As an alternative, one might consider multishot pulse sequences, which may lead to somewhat lower temporal SNR than standard EPI, but which are also often substantially less susceptible to off-resonance effects. Here we consider retinotopic mapping of human visual cortex as a practical test case by which to compare examples of these sequence types for high-resolution fMRI at 7 Tesla. We performed polar angle retinotopic mapping at each of 3 isotropic resolutions (2.0, 1.7, and 1.1 mm) using both accelerated single-shot 2D EPI and accelerated multishot 3D gradient-echo pulse sequences. We found that single-shot EPI indeed led to greater temporal SNR and contrast-to-noise ratios (CNR) than the multishot sequences. However, additional distortion correction in postprocessing was required in order to fully realize these advantages, particularly at higher resolutions. The retinotopic maps produced by both sequence types were qualitatively comparable, and showed equivalent test/retest reliability. Thus, when surface-based analyses are planned, or in other circumstances where geometric distortion is of particular concern, multishot pulse sequences could provide a viable alternative to single-shot EPI

Authenticity and drug resistance in a panel of acute lymphoblastic leukaemia cell lines

Cell lines are important models for drug resistance in acute lymphoblastic leukaemia (ALL), but are often criticised as being unrepresentative of primary disease. There are also doubts regarding the authenticity of many lines. We have characterised a panel of ALL cell lines for growth and drug resistance and compared data with that published for primary patient specimens. In contrast to the convention that cell lines are highly proliferative, those established in our laboratory grow at rates similar to estimates of leukaemic cells in vivo (doubling time 53–442 h). Authenticity was confirmed by genetic fingerprinting, which also demonstrated the potential stability of long-term cultures. In vitro glucocorticoid resistance correlated well with that measured ex vivo, but all lines were significantly more sensitive to vincristine than primary specimens. Sensitivity to methotrexate was inversely correlated to that of glucocorticoids and L-asparaginase, indicating possible reciprocity in resistance mechanisms. A cell line identified as highly methotrexate resistant (IC50 >8000-fold higher than other lines) was derived from a patient receiving escalating doses of the drug, indicating in vivo selection of resistance as a cause of relapse. Many of these lines are suitable as models to study naturally occurring resistance phenotypes in paediatric ALL