4,391 research outputs found
Dietary flavonoid intake and weight maintenance: three prospective cohorts of 124,086 US men and women followed for up to 24 years
Objective: To examine whether dietary intake of specific flavonoid sub-classes is associated with weight change over time, including flavonols, flavones, flavanones, flavan-3-ols, anthocyanins, and flavonoid polymers. Design: Three prospective cohort studies. Setting: Health professionals in the United States. Participants: 124,086 men and women participating in the Health Professionals Follow-up Study (HPFS), Nursesâ Health Study (NHS), and Nursesâ Health Study II (NHS II). Main outcome measure: Self-reported change in weight over multiple 4-year time intervals between 1986 and 2011. Results: Increased consumption of most flavonoid sub-classes, including flavonols, flavan-3-ols, anthocyanins, and flavonoid polymers was inversely associated with weight change over 4-year time intervals, after adjustment for simultaneous changes in other lifestyle factors including other aspects of diet, smoking status, and physical activity. In the pooled results, the greatest magnitude of association was observed for anthocyanins (-0.22 lbs, 95% CI -0.30 to -0.15 lbs per additional SD/day, 10 mg), flavonoid polymers (-0.18 lbs, 95% CI -0.28 to -0.08 lbs per additional SD/day, 138 mg), and flavonols (-0.16 lbs, 95% CI -0.26 to -0.06 lbs per additional SD/day, 7 mg). After additional adjustment for fiber intake associations remained significant for anthocyanins, proanthocyanidins, and total flavonoid polymers but were attenuated and no longer statistically significant for other sub-classes. Conclusions: Higher intake of foods rich in flavonols, flavan-3-ols, anthocyanins, and flavonoid polymers, may contribute to weight maintenance in adulthood, and may help to refine dietary recommendations for the prevention of obesity and its potential sequelae
Effect of Surface Oxidation on the Onset of Nucleate Boiling in a Materials Test Reactor Coolant Channel
The onset of nucleate boiling (ONB) serves as the thermal-hydraulic operating limit for many research and test reactors. However, boiling incipience under forced convection has not been well-characterized in narrow channel geometries or for oxidized surface conditions. This study presents experimental data for the ONB in vertical upflow of deionized (DI) water in a simulated materials test reactor (MTR) coolant channel. The channel gap thickness and aspect ratio were 1.96 mm and 29:1, respectively. Boiling surface conditions were carefully controlled and characterized, with both heavily oxidized and native oxide surfaces tested. Measurements were performed for mass fluxes ranging from 750 to 3000 kg/m2s and for subcoolings ranging from 10 to 45°C. ONB was identified using a combination of high-speed visual observation, surface temperature measurements, and channel pressure drop measurements. Surface temperature measurements were found to be most reliable in identifying the ONB. For the nominal (native oxide) surface, results indicate that the correlation of Bergles and Rohsenow, when paired with the appropriate single-phase heat transfer correlation, adequately predicts the ONB heat flux. Incipience on the oxidized surface occurred at a higher heat flux and superheat than on the plain surface.United States. Department of Energy. Office of Nonproliferation and National SecurityUnited States. National Nuclear Security Administration. Global Threat Reduction Initiative (Contract No. #25-30101-0004A) (United States. National Nuclear Security Administration (contract no. DE-AC04-94AL85000
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Acupressure to Reduce Treatment-Related Symptoms for Children With Cancer and Recipients of Hematopoietic Stem Cell Transplant: Protocol for a Randomized Controlled Trial.
BackgroundWe describe the study design and protocol of a pragmatic randomized controlled trial (RCT) Acupressure for Children in Treatment for a Childhood Cancer (ACT-CC).ObjectiveTo describe the feasibility and effectiveness of an acupressure intervention to decrease treatment-related symptoms in children in treatment for cancer or recipients of a chemotherapy-based hematopoietic stem cell transplant (HSCT).DesignTwo-armed RCTs with enrollment of 5 to 30 study days.SettingTwo pediatric teaching hospitals.PatientsEighty-five children receiving cancer treatment or a chemotherapy-based HSCT each with 1 parent or caregiver.InterventionPatients are randomized 1:1 to receive either usual care plus daily professional acupressure and caregiver delivered acupressure versus usual care alone for symptom management. Participants receive up to 20 professional treatments.Main outcomeA composite nausea/vomiting measure for the child.Secondary outcomesChild's nausea, vomiting, pain, fatigue, depression, anxiety, and positive affect.Parent outcomesDepression, anxiety, posttraumatic stress symptoms, caregiver self-efficacy, and positive affect. Feasibility of delivering the semistandardized intervention will be described. Linear mixed models will be used to compare outcomes between arms in children and parents, allowing for variability in diagnosis, treatment, and age.DiscussionTrial results could help childhood cancer and HSCT treatment centers decide about the regular inclusion of trained acupressure providers to support symptom management
Factors Influencing Pediatric Dental Program Directorsâ Selection of Residents and Demographics of Current Directors
The primary goal of this study was to examine the criteria that influence rankings of candidates by advanced education program directors in pediatric dentistry. Secondary objectives were to obtain information on the resident selection process and to explore demographics of current program directors. A survey was sent in 2005 to all sixtyâ three program directors of pediatric dentistry residency programs accredited within the United States for the graduating class of 2007. The survey had a response rate of almost 78 percent (49/63). Respondents were requested to rank the importance of eleven factors that are typically included in the selection criteria for pediatric dentistry residents. Factors were rated on a scale of critical, very important, fairly important, somewhat important, and not important. The four highest ranked criteria by program directors were the following, in order: National Board scores, dental school clinical grades, class rank, and grade point average (GPA). Other factors ranked in descending order of perceived importance were the following: dental school basic science grades, experience in pediatric dentistry, extracurricular activities, completion of a general practice residency or advanced education in general dentistry program, the application essay, a publication or professional presentation, and private practice experience. All directors ranked personal interviews as very important to critical. Letters of recommendation from a pediatric dentistry department chairperson or faculty member were viewed more favorably than letters from dental school deans and nonâ pediatric dentistry faculty. Fiftyâ seven percent of the directors responding (28/49) were male, and 81 percent (40/49) were white, nonâ Hispanic. Fiftyâ nine percent of the directors (29/49) graduated from a residency program over twenty years ago, with 39 percent (19/49) having been a director for less than five years.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/153594/1/jddj002203372009733tb04706x.pd
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Rice consumption and risk of cardiovascular disease: results from a pooled analysis of 3 U.S. cohorts1234
Background: Health concerns have been raised about rice consumption, which may significantly contribute to arsenic exposure. However, little is known regarding whether habitual rice consumption is associated with cardiovascular disease (CVD) risk. Objective: We examined prospectively the association of white rice and brown rice consumption with CVD risk. Design: We followed a total of 207,556 women and men [73,228 women from the Nursesâ Health Study (1984â2010), 92,158 women from the Nursesâ Health Study II (1991â2011), and 42,170 men from the Health Professionals Follow-Up Study (1986â2010)] who were free of CVD and cancer at baseline. Validated semiquantitative food-frequency questionnaires were used to assess consumption of white rice, brown rice, and other food items. Fatal and nonfatal CVD (coronary artery disease and stroke) was confirmed by medical records or self-reports. Results: During 4,393,130 person-years of follow-up, 12,391 cases of CVD were identified. After adjustment for major CVD risk factors, including demographics, lifestyle, and other dietary intakes, rice consumption was not associated with CVD risk. The multivariable-adjuted HR of developing CVD comparing âĽ5 servings/wk with <1 serving/wk was 0.98 (95% CI: 0.84, 1.14) for white rice, 1.01 (0.79, 1.28) for brown rice, and 0.99 (0.90, 1.08) for total rice. To minimize the potential impact of racial difference in rice consumption, we restricted the analyses to whites only and obtained similar results: the HRs of CVD for âĽ5 servings/wk compared with <1 serving/wk were 1.04 (95% CI: 0.88, 1.22) for white rice and 1.01 (0.78, 1.31) for brown rice. Conclusions: Greater habitual consumption of white rice or brown rice is not associated with CVD risk. These findings suggest that rice consumption may not pose a significant CVD risk among the U.S. population when consumed at current amounts. More prospective studies are needed to explore these associations in other populations
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Genetic Predisposition to High Blood Pressure Associates With Cardiovascular Complications Among Patients With Type 2 Diabetes: Two Independent Studies
Hypertension and type 2 diabetes (T2D) commonly coexist, and both conditions are major risk factors for cardiovascular disease (CVD). We aimed to examine the association between genetic predisposition to high blood pressure and risk of CVD in individuals with T2D. The current study included 1,005 men and 1,299 women with T2D from the Health Professionals Follow-up Study and Nursesâ Health Study, of whom 732 developed CVD. A genetic predisposition score was calculated on the basis of 29 established blood pressureâassociated variants. The genetic predisposition score showed consistent associations with risk of CVD in men and women. In the combined results, each additional blood pressureâincreasing allele was associated with a 6% increased risk of CVD (odds ratio [OR] 1.06 [95% CI 1.03â1.10]). The OR was 1.62 (1.22â2.14) for risk of CVD comparing the extreme quartiles of the genetic predisposition score. The genetic association for CVD risk was significantly stronger in patients with T2D than that estimated in the general populations by a meta-analysis (OR per SD of genetic score 1.22 [95% CI 1.10â1.35] vs. 1.10 [1.08â1.12]; I2 = 71%). Our data indicate that genetic predisposition to high blood pressure is associated with an increased risk of CVD in individuals with T2D
The Bayes factor and its implementation in JASP: A practical primer
Statistical inference plays a critical role in modern scientific research, however, the dominant method for statistical inference in science, null hypothesis significance testing (NHST), is often misunderstood and misused, which leads to unreproducible findings. To address this issue, researchers propose to adopt the Bayes factor as an alternative to NHST. The Bayes factor is a principled Bayesian tool for model selection and hypothesis testing, and can be interpreted as the strength for both the null hypothesis H0 and the alternative hypothesis H1 based on the current data. Compared to NHST, the Bayes factor has the following advantages: it quantifies the evidence that the data provide for both the H0 and the H1, it is not âviolently biasedâ against H0, it allows one to monitor the evidence as the data accumulate, and it does not depend on sampling plans. Importantly, the recently developed open software JASP makes the calculation of Bayes factor accessible for most researchers in psychology, as we demonstrated for the t-test. Given these advantages, adopting the Bayes factor will improve psychological researchersâ statistical inferences. Nevertheless, to make the analysis more reproducible, researchers should keep their data analysis transparent and open
Intakes of fruits, vegetables and carbohydrate and the risk of CVD
BACKGROUND: Low-carbohydrate diets could lead to reduced fruit and vegetable intake, which may be protective against CVD. The role of carbohydrate intake in modifying the association between fruits and vegetables and CVD has not been evaluated. OBJECTIVE: To evaluate whether carbohydrate intake affects the association between fruits and vegetables and CVD. DESIGN: We included participants from two large prospective studies, the Nurses' Health Study (NHS) and the Health Professionals' Follow-Up Study (HPFS). We followed 70870 eligible NHS females for 16 years and 38918 eligible HPFS males for 14 years. Diet was assessed from an FFQ updated every 4 years. Our primary outcome was ischaemic CVD (fatal and non-fatal myocardial infarction and ischaemic stroke). We used Cox proportional hazards models to evaluate the relationship between fruits and vegetables and ischaemic CVD within groups with low, moderate or high carbohydrate intake. RESULTS: Fruit intake was strongly related with carbohydrate intake, but vegetables showed a very small correlation. Vegetable intake showed stronger associations with ischaemic CVD among the low carbohydrate group (multivariate risk ratio (RR) = 0.82 for an increment of 3 servings/d; 95% CI 0.68, 0.99); green leafy vegetables and carotene-rich fruits and vegetables followed a similar pattern. Total fruit intake was associated with a lower risk of ischaemic CVD only among participants with moderate carbohydrate intake (RR = 0.81 comparing extreme quintiles; 95% CI 0.70, 0.94). CONCLUSIONS: Total vegetables, green leafy vegetables and carotene-rich fruits and vegetables showed stronger associations with ischaemic CVD among the low carbohydrate group. No consistent trends were observed for fruit intake
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