907 resultados para single-case A-B-fase design


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Objective: To determine the minimum effective dose of folic acid required to appreciably increase serum folate and to produce a significant reduction in plasma total homocysteine (tHcy).

Design:
Double-blind, randomised placebo-controlled intervention trial.

Setting: Community-based project in a New Zealand city.

Subjects:
Seventy free living men and women with tHcy10 µmol/l. Mean age (range) was 58 (29-90) y.

Interventions: Daily consumption over 4 weeks of 20 g breakfast cereal either unfortified (placebo) or fortified with 100, 200 or 300 µg folic acid. Dietary intake was determined by weighed diet records and consumption of commercially fortified products was avoided.

Main outcome measures: Plasma tHcy and serum folate concentrations.

Results: Average serum folate concentrations (95% CI) increased significantly in the treatment groups relative to the control group by 28(9-51)%, 60(37-87)% and 79(51-114)% for supplementation with 100, 200 and 300 µg folic acid, respectively. A reduction in tHcy was observed, being 16(8-22)%, 12(4-18)% and 17(9-24)% in the three treatment groups, respectively.

Conclusions: A regular intake of as little as 100 µg folic acid per day was sufficient to lower tHcy in persons at the upper end of the normal range for tHcy. Low-level fortification may also be appropriate for lowering the risk of neural tube defects given that, when aggregated from all sources, the total intake of folic acid may be sufficiently high to adequately improve the folate status of young women.

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Objective: Substance abuse remains one of the major threats to adolescent health in Western cultures. The study aim was to ascertain the extent of association between pubertal development and early adolescent substance use.

Methods: The design was a cross-sectional survey of 10- to 15-year-old subjects in the states of Washington, United States, and Victoria, Australia. Participants were 5769 students in grades 5, 7, and 9, drawn as a 2-stage cluster sample in each state, and the questionnaire was completed in the school classrooms. The main outcomes of the study were lifetime substance use (tobacco use, having been drunk, or cannabis use), recent substance use (tobacco, alcohol, or cannabis use in the previous month), and substance abuse (daily smoking, any binge drinking, drinking at least weekly, or cannabis use at least weekly).

Results: The odds of lifetime substance use were almost twofold higher (odds ratio [OR]: 1.7; 95% confidence interval [CI]: 1.4–2.1) in midpuberty (Tanner stage III) and were threefold higher (OR: 3.1; 95% CI: 2.4–4.2) in late puberty (Tanner stage IV/V), after adjustment for age and school grade level. Recent substance use was moderately higher (OR: 1.4; 95% CI: 1.0–1.9) in midpuberty and more than twofold higher (OR: 2.3; 95% CI: 1.7–3.3) in late puberty. The odds of substance abuse were twofold higher (OR: 2.0; 95% CI: 1.2–3.2) in midpuberty and more than threefold higher (OR: 3.5; 95% CI: 2.2–5.4) in late puberty. Reporting most friends as substance users was more likely in the later stages of pubertal development, a relationship that accounted in part for the association found between later pubertal stage and substance abuse.

Conclusions: Pubertal stage was associated with higher rates of substance use and abuse independent of age and school grade level. Early maturers had higher levels of substance use because they entered the risk period at an earlier point than did late maturers. The study findings support prevention strategies and policies that decrease recreational substance use within the peer social group in the early teens.

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Background
The PEACH study is based on an innovative 'telephone coaching' program that has been used effectively in a post cardiac event trial. This intervention will be tested in a General Practice setting in a pragmatic trial using existing Practice Nurses (PN) as coaches for people with type 2 diabetes (T2D). Actual clinical care often fails to achieve standards, that are based on evidence that self-management interventions (educational and psychological) and intensive pharmacotherapy improve diabetes control. Telephone coaching in our study focuses on both. This paper describes our study protocol, which aims to test whether goal focused telephone coaching in T2D can improve diabetes control and reduce the treatment gap between guideline based standards and actual clinical practice.
Methods/design
In a cluster randomised controlled trial, general practices employing Practice Nurses (PNs) are randomly allocated to an intervention or control group. We aim to recruit 546 patients with poorly controlled T2D (HbA1c >7.5%) from 42 General Practices that employ PNs in Melbourne, Australia. PNs from General Practices allocated to the intervention group will be trained in diabetes telephone coaching focusing on biochemical targets addressing both patient self-management and engaging patients to work with their General Practitioners (GPs) to intensify pharmacological treatment according to the study clinical protocol. Patients of intervention group practices will receive 8 telephone coaching sessions and one face-to-face coaching session from existing PNs over 18 months plus usual care and outcomes will be compared to the control group, who will only receive only usual care from their GPs. The primary outcome is HbA1c levels and secondary outcomes include cardiovascular disease risk factors, behavioral risk factors and process of care measures.
Discussion
Understanding how to achieve comprehensive treatment of T2D in a General Practice setting is the focus of the PEACH study. This study explores the potential role for PNs to help reduce the treatment and outcomes gap in people with T2D by using telephone coaching. The intervention, if found to be effective, has potential to be sustained and embedded within real world General Practice.

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OBJECTIVE—We examined the associations of television viewing time with fasting plasma glucose (FPG) and 2-h postchallenge plasma glucose (2-h PG) levels in Australian adults.

RESEARCH DESIGN AND METHODS—A total of 8,357 adults aged >35 years who were free from diagnosed diabetes and who attended a population-based cross-sectional study (Australian Diabetes, Obesity and Lifestyle Study [AusDiab]) were evaluated. Measures of FPG and 2-h PG were obtained from an oral glucose tolerance test. Self-reported television viewing time (in the previous week) was assessed using an interviewer-administered questionnaire. Homeostasis model assessment (HOMA) of insulin sensitivity (HOMA-%S) and ß-cell function (HOMA-%B) were calculated based on fasting glucose and insulin concentrations.

RESULTS—After adjustment for confounders and physical activity time, time spent watching television in women was positively associated with 2-h PG, log fasting insulin, and log HOMA-%B and inversely associated with log HOMA-%S (P < 0.05) but not with FPG. No significant associations were observed with glycemic measures in men. The ß-coefficients across categories of average hours spent watching television per day (<1.0, 1.0–1.9, 2.0–2.9, 3.0–3.9, and ≥4.0) for 2-h PG in women were 0 (reference), 0.009, 0.047, 0.473, and 0.501, respectively (P for trend = 0.02).

CONCLUSIONS—Our findings highlight the unique deleterious relationship of sedentary behavior (indicated by television viewing time) and glycemic measures independent of physical activity time and adiposity status. These relationships differed according to sex and type of glucose measurement, with the 2-h PG measure being more strongly associated with television viewing. The findings suggest an important role for reducing sedentary behavior in the prevention of type 2 diabetes and cardiovascular disease, especially in women.

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Objective: We examined the associations of objectively measured sedentary time, light-intensity physical activity, and moderate- to vigorous-intensity activity with fasting and 2-h postchallenge plasma glucose in Australian adults.

Research Design and Methods: A total of 67 men and 106 women (mean age ± SD 53.3 ± 11.9 years) without diagnosed diabetes were recruited from the 2004–2005 Australian Diabetes, Obesity, and Lifestyle (AusDiab) study. Physical activity was measured by Actigraph  accelerometers worn during waking hours for 7 consecutive days and summarized as sedentary time (accelerometer counts/min <100; average hours/day), light-intensity (counts/min 100-1951), and moderate- to vigorous-intensity (counts/min ≥1,952). An oral glucose tolerance test was used to ascertain 2-h plasma glucose and fasting plasma glucose.

Results: After adjustment for confounders (including waist circumference), sedentary time was positively associated with 2-h plasma glucose (b = 0.29, 95% CI 0.11–0.48, P = 0.002); light-intensity activity time (b = –0.25, –0.45 to –0.06, P = 0.012) and moderate- to vigorous-intensity activity time (b = –1.07, –1.77 to –0.37, P = 0.003) were negatively associated. Light-intensity activity remained significantly associated with 2-h plasma glucose following further adjustment for moderate- to vigorous-intensity activity (b = –0.22, –0.42 to –0.03, P = 0.023). Associations of all activity measures with fasting plasma glucose were nonsignificant (P > 0.05).

Conclusions
: These data provide the first objective evidence that light-intensity physical activity is beneficially associated with blood glucose and that sedentary time is unfavorably associated with blood glucose. These objective data support previous findings from studies using self-report measures, and suggest that substituting light-intensity activity for television viewing or other sedentary time may be a practical and achievable preventive strategy to reduce the risk of type 2 diabetes and cardiovascular disease.

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Background: Depression amongst adolescents is a costly societal problem. Little research documents the effectiveness of public mental health services in mapping this problem. Further, it is not clear whether usual care in such services can be improved via clinician training in a relevant evidence based intervention. One such intervention, found to be effective and easily learned amongst novice clinicians, is Interpersonal Psychotherapy (IPT). The study described in the current paper has two main objectives. First, it aims to investigate the impact on clinical care of implementing Interpersonal Psychotherapy for Adolescents for the treatment of adolescent depression within a rural mental health service compared with Treatment as Usual (TAU). The second objective is to record the process and challenges (i.e. feasibility, acceptability, sustainability) associated with implementing and evaluating an evidence-based intervention within a community service. This paper outlines the study rationale and design for this community based research trial.

Methods/design: The study involves a cluster randomisation trial to be conducted within a Child and Adolescent Mental Health Service in rural Australia. All clinicians in the service will be invited to participate.  Participating clinicians will be randomised via block design at each of four sites to (a) training and delivery of IPT, or (b) TAU. The primary measure of impact on care will be a clinically significant change in depressive  symptomatology, with secondary outcomes involving treatment satisfaction and changes in other symptomatology. Participating adolescents with significant depressive symptomatology, aged 12 to 18 years, will complete assessment measures at Weeks 0, 12 and 24 of treatment. They will also complete a depression inventory once a month during that period. This study aims to recruit 60 adolescent participants and their parent/guardian/s. A power analysis is not indicated as an intra-class correlation coefficient will be calculated and used to inform sample size calculations for subsequent large-scale trials. Qualitative data regarding process implementation will be collected quarterly from focus groups with participating clinicians over 18 months, plus phone interviews with participating adolescents and parent/guardians at 12 weeks and 24 weeks of treatment. The focus group qualitative data will be analysed using a Fourth Generation Evaluation methodology that includes a constant comparative cyclic analysis method.

Discussion
: This study protocol will be informative for researchers and clinicians interested in considering, designing and/or conducting cluster randomised trials within community practice such as mental health services.

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This article explores the tacit understanding of teachers in the field of gifted educational practices after their participation in gifted education professional development. The data for this article are drawn from a single-case qualitative study where semi-structured interviews were held with teachers, administrators and support staff in a metropolitan Victorian primary school. The findings lead to two main arguments: first, that some teachers preserved their deeply entrenched beliefs and assumptions about the gifted, the talented and intelligence[s]; and second, that teachers, without critical examination, eagerly adopted and adapted Gardner's Multiple Intelligences theory, overlaid with Bloom's Revised Taxonomy of Thinking as a means for addressing individual differences in the classroom. The article argues that teachers welcomed the Gardner/Bloom matrix for its 'tick-the-box' simplicity, with little insight into the theoretical models. Whilst the matrix had an immediate value in the mixed ability classrooms, in the long term it did not support the learning needs of gifted students. [Author abstract]

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This work looks at two different “Design of Experiments”(DoE) methods for defining an operating window in the sheet metal stamping process. The first involves the use of replicates at the different experimental points, while the second is a nonreplicated method. The two methods are compared by looking at the relationship results produced and the indication of variation in the process. It is found that the results from both the methods are very similar. However, the replicated method provides a greater level of confidence in the results. In the stamping process, where performing large numbers of replicates is expensive in both time and money, the nonreplicated method provides a cost effective way of understanding the process.


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OBJECTIVE—To determine the population-based prevalence of diabetes and other categories of glucose intolerance (impaired glucose tolerance [IGT] and impaired fasting glucose [IFG]) in Australia and to compare the prevalence with previous Australian data.

RESEARCH DESIGN AND METHODS—A national sample involving 11,247 participants aged >=25 years living in 42 randomly selected areas from the six states and the Northern Territory were examined in a cross-sectional survey using the 75-g oral glucose tolerance test to assess fasting and 2-h plasma glucose concentrations. The World Health Organization diagnostic criteria were used to determine the prevalence of abnormal glucose tolerance.

RESULTS—The prevalence of diabetes in Australia was 8.0% in men and 6.8% in women, and an additional 17.4% of men and 15.4% of women had IGT or IFG. Even in the youngest age group (25–34 years), 5.7% of subjects had abnormal glucose tolerance. The overall diabetes prevalence in Australia was 7.4%, and an additional 16.4% had IGT or IFG. Diabetes prevalence has more than doubled since 1981, and this is only partially explained by changes in age profile and obesity.

CONCLUSIONS—Australia has a rapidly rising prevalence of diabetes and other categories of abnormal glucose tolerance. The prevalence of abnormal glucose tolerance in Australia is one of the highest yet reported from a developed nation with a predominantly Europid background.

Abbreviations: 2hPG, 2-h plasma glucose • AusDiab, Australian Diabetes, Obesity and Lifestyle Study • CD, Census Collector District • FPG, fasting plasma glucose • IFG, impaired fasting glucose • IGT, impaired glucose tolerance • KDM, known diabetes mellitus • NDM, newly diagnosed diabetes mellitus • OGTT, oral glucose tolerance test • WHO, World Health Organization

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OBJECTIVE— To determine the association between serum 25-hydroxyvitamin D (25OHD) and diabetes risk and whether it varies by ethnicity.
RESEARCH DESIGN AND METHODS— We performed an analysis of data from participants who attended the morning examination of the Third National Health and Nutrition Examination Survey (1988–1994), a cross-sectional survey of a nationally representative sample of the U.S. population. Serum levels of 25OHD, which reflect vitamin D status, were available from 6,228 people (2,766 non-Hispanic whites, 1,736 non-Hispanic blacks, and 1,726 Mexican Americans) aged ≥20 years with fasting and/or 2-h plasma glucose and serum insulin measurements.
RESULTS— Adjusting for sex, age, BMI, leisure activity, and quarter of year, ethnicityspecific odds ratios (ORs) for diabetes (fasting glucose ≥7.0 mmol/l) varied inversely across quartiles of 25OHD in a dose-dependent pattern (OR 0.25 [95% CI 0.11– 0.60] for non-Hispanic whites and 0.17 [0.08–0.37] for Mexican Americans) in the highest vitamin D quartile (25OHD ≥81.0 nmol/l) compared with the lowest 25OHD (≥43.9 nmol/l). This inverse association
was not observed in non-Hispanic blacks. Homeostasis model assessment of insulin resistance (loge) was inversely associated with serum 25OHD in Mexican Americans (P ≥ 0.0024) and non-Hispanic whites (P≥0.058) but not non-Hispanic blacks (P≥0.93), adjusting for confounders.
CONCLUSIONS— These results show an inverse association between vitamin D status and diabetes, possibly involving insulin resistance, in non-Hispanic whites and Mexican Americans. The lack of an inverse association in non-Hispanic blacks may reflect decreased sensitivity to vitamin D and/or related hormones such as the parathyroid hormone.

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OBJECTIVE—To examine whether improvements in glycemic control and body composition resulting from 6 months of supervised high-intensity progressive resistance training could be maintained after an additional 6 months of home-based resistance training.

RESEARCH DESIGN AND METHODS—We performed a 12-month randomized controlled trial in 36 sedentary, overweight men and women with type 2 diabetes (aged 60–80 years) who were randomly assigned to moderate weight loss plus high-intensity progressive resistance training (RT&WL group) or moderate weight loss plus a control program (WL group). Supervised gymnasium-based training for 6 months was followed by an additional 6 months of home-based training. Glycemic control (HbA1c), body composition, muscle strength, and metabolic syndrome abnormalities were assessed at 0, 3, 6, 9, and 12 months.

RESULTS—Compared with the WL group, HbA1c decreased significantly more in the RT&WL group (–0.8%) during 6 months of supervised gymnasium-based training; however, this effect was not maintained after an additional 6 months of home-based training. In contrast, the greater increase in lean body mass (LBM) observed in the RT&WL group compared with the WL group (0.9 kg, P < 0.05) after the gymnasium-based training tended to be maintained after the home-based training (0.8 kg, P = 0.08). Similarly, the gymnasium-based increases in upper body and lower body muscle strength in the RT&WL group were maintained over the 12 months (P < 0.001). There were no between-group differences for changes in body weight, fat mass, fasting glucose, or insulin at 6 or 12 months.

CONCLUSIONS—In older adults with type 2 diabetes, home-based progressive resistance training was effective for maintaining the gymnasium-based improvements in muscle strength and LBM but not glycemic control. Reductions in adherence and exercise training volume and intensity seem to impede the effectiveness of home-based training for maintaining improved glycemic control.


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Purpose – Pareto’s Law often refers to the theory that a small percentage of a total is responsible for a large proportion of the total outcome. It is commonly known as the 80/20 law or principle. The objective is to review and debate whether there is a “Pareto syndrome” in the distribution of crucial research and journal criteria in top marketing journals.

Design/methodology/approach –
The authors provide a review and a debate based upon previous research on top marketing journals. For this purpose, the Pareto syndrome concept is introduced, based upon a set of research and journal criteria. Their distribution is examined.

Findings –
The review of research and journal criteria in top marketing journals generated an extremely skewed outcome. When it comes to the criteria, the top journals in marketing tend to be governed by narrow concerns of research rather than broad ones.

Research limitations/implications –
The research and journal criteria that have a skewed outcome may reinforce the rigidity and the lack of innovativeness of the marketing discipline. The evolutionary speed of the discipline may at best be reduced or it may at worst grind to a halt. The authors argue that there are a number of serious concerns to be addressed in the future review and debate of top journals in marketing.

Practical implications –
Editors and editorial boards need seriously to address the concerns reviewed and debated, namely the skewed distribution of criteria, such as affiliation, data and methodology.

Originality/value –
The authors debate that there is evidence that confirms the existence of a Pareto plus syndrome in key research and journal criteria of top marketing journals.

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The synthesis and characterization of unsymmetric diorganotellurium compounds containing a sterically demanding I-naphthyl or
mesitylligand and a small bite chelating organic ligand capable of 1,4-Te···N(O) intramolecular interaction is described. The reaction
of ArTeCl3 (Ar = I-ClOH7, Np; 2,4,6-Me3C6H2' Mes) with (SB)HgCI [SB = the Schiff base, 2-(4,4'-N02C6H4CH=NC6H3-Me)] or a methyl ketone (RCOCH3) afforded the corresponding dichlorides (SB)ArTeCI2 (Ar = Np, 1Aa; Mes, 1Ba) or (RCOCH2)ArTeCl2 (Ar = Np; R = Ph (2Aa), Me (3Aa), Np (4Aa); Ar = Mes, R = Ph (2Ba)). Reduction of 1Aa and 1Ba by Na2S205 readily gave the tellurides (SB)ArTe (Ar = Np (1A), Mes, (1B) but that of dichlorides derived from methylketones was complicated due to partial decomposition to tellurium powder and diarylditelluride (Ar2Te2), resulting in poor yields of the corresponding tellurides 2A, 2B and 3A. Oxidation of the isolated tellurides with S02Cl2, Br2 and I2 yielded the corresponding dihalides. All the synthesized compounds have been characterized with the help of IR, 1H, l3C, and 125Te NMR and in the case of 2Aa, and 2Ba by X-ray crystallography. Appearance of only one 125Te signal indicated that the unsymmetric derivatives were stable to disproportionation to symmetric species. Intramolecular 1,4-Te· . ·0 secondary bonding interactions (SBIs) are exhibited in the crystal structures of both the tellurium(IV) dichlorides, 2Aa, and 2Ba. Steric repulsion of the mesityl group in the latter dominates over lone pair-bond pair repulsion, resulting in significant widening of the equatorial C-Te-C angle. This appears to be responsible for the lack of Te· . ·CI involved supramolecular associations in the crystal structure of 2Ba.

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Objective: To devise more-effective physical activity interventions, the mediating mechanisms yielding behavioral change need to be identified. The Baron–Kenny method is most commonly used, but has low statistical power and may not identify mechanisms of behavioral change in small-to-medium size studies. More powerful statistical tests are available.
Study Design and Setting: Inactive adults (N = 52) were randomized to either a print or a print-plus-telephone intervention. Walking and exercise-related social support were assessed at baseline, after the intervention, and 4 weeks later. The Baron–Kenny and three alternative methods of mediational analysis (Freedman–Schatzkin; MacKinnon et al.; bootstrap method) were used to examine the effects of social support on initial behavior change and maintenance. Results: A significant mediational effect of social support on initial behavior change was indicated by the MacKinnon et al., bootstrap, and, marginally, Freedman–Schatzkin methods, but not by the Baron–Kenny method. No significant mediational effect of social support on maintenance of walking was found. Conclusions:  Methodologically rigorous intervention studies to identify mediators of change in physical activity are costly and labor ntensive, and may not be feasible with large samples. The use of statistically powerful tests of mediational effects in small-scale studies can inform the development of more effective interventions.

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Background: The effect of surgery on patellar tendinopathy (jumper's knee) is questionable, and conservative treatment protocols have not been properly documented.

Purpose: The aim of this study was to investigate the effect of a newly developed eccentric training program for patellar tendinopathy in volleyball players during the competitive season.

Study Design: Randomized clinical trial.

Methods: Patients were recruited from male and female elite volleyball teams in Norway, and the diagnosis was based on clinical examination alone. Of 51 players diagnosed with patellar tendinopathy, 29 could be included in the study. The training group (n = 13) performed squats on a 25° decline board as a home exercise program (3 × 15 repetitions twice daily) for a 12-week intervention period during the final half of the competitive season. The eccentric (downward) component was done on the affected leg. The control group (n = 16) trained as usual. The primary outcome was a symptom-based questionnaire developed specifically for patellar tendinopathy (Victorian Institute of Sport Assessment score), and patients were followed up before and after the intervention period, as well as after 6 and 30 weeks. All subjects self-recorded training to document their activity level (eccentric training, volleyball training, matches, other training).

Results:
There was no change in Victorian Institute of Sport Assessment score during the intervention period in the training (pre, 71.1 ± 11.3; post, 70.2 ± 15.4) or control group (pre, 76.4 ± 12.1; post, 75.4 ± 16.7), nor was there any change during the follow-up period at 6 weeks or 6 months. The training group completed 8.2 ± 4.6 weekly sessions of eccentric training during the intervention period (59% of the recommended volume), and there was no difference between groups in training or competition load.

Conclusion: There was no effect on knee function from a 12-week program with eccentric training among a group of volleyball players with patellar tendinopathy who continued to train and compete during the treatment period. Whether the training would be effective if the patients did not participate in sports activity is not known.