bluuebunny/crossref_metadata_2025 huggingface dataset:
Impaired Fat‐induced Thermogenesis in Obese Subjects: The NUGENOB Study
Authors: Blaak Ellen E. , Hul Gabby , Verdich Camilla , Stich Vladimir , Martinez J. Alfredo , Petersen Martin , Feskens Edith F. M. , Patel Kishor , Oppert Jean Michel , Barbe Pierre , Toubro Søren , Polak Jan , Anderson Ingalena , Astrup Arne , Macdonald Ian , Langin Dominique , Sørensen Thorkild , Saris Wim H. ,   The NUGENOB Consortium
Published: July 2008

Objectives: To study energy expenditure before and 3 hours after a high‐fat load in a large cohort of obese subjects (n = 701) and a lean reference group (n = 113).

Research Methods and Procedures: Subjects from seven European countries underwent a 1‐day clinical study with a liquid test meal challenge containing 95% fat (energy content was 50% of estimated resting energy expenditure). Fasting and 3‐hour postprandial energy expenditures, as well as metabolites and hormones, were determined.

Results: Obese subjects had a reduced postprandial energy expenditure after the high‐fat load, independent of body composition, age, sex, research center, and resting energy expenditure, whereas within the obese group, thermogenesis increased again with increasing BMI category. Additionally, insulin resistance, habitual physical activity, postprandial plasma triacylglycerols, and insulin were all independently positively related to the postprandial energy expenditure. Resting energy expenditure, adjusted for fat‐free mass, increased with degree of obesity, a difference that disappeared after adjustment for fat mass. Furthermore, insulin resistance, fasting plasma free fatty acids, and cortisol were positively associated, whereas fasting plasma leptin and insulin‐like growth factor‐1 were negatively associated, with resting energy expenditure.

Discussion: The 3‐hour fat‐induced thermogenic response is reduced in obesity. It remains to be determined whether this blunted thermogenic response is a contributory factor or an adaptive response to the obese state.
Effect of Weight Loss on Free Insulin‐Like Growth Factor‐I in Obese Women With Hyposomatotropism
Authors: Rasmussen Michael H. , Juul Anders , Hilsted Jannik
Published: July 2008

Objective: It has been hypothesized that increased free insulin‐like growth factor (IGF)‐I levels generated from an increase in IGF‐binding protein (IGFBP) protease activity could be the inhibitory mechanism for the decreased growth hormone (GH) secretion observed in obese subjects.

Research Methods and Procedures: In this study, we determined basal and 24‐hour levels of free IGF‐I and ‐II, total IGF‐I and ‐II, IGFBP‐1, as well as basal IGFBP‐2, −3, and −4, acid‐labile subunit (ALS), IGFBP‐1, −2, and −3 protease activity, and 24‐hour GH release in obese women before and after a diet‐induced weight loss. Sixteen obese women (age, 29.5 ± 1.4 years) participated in a weight loss program and 16 age‐matched non‐obese women served as controls.

Results: Circulating free IGF‐I and 24‐hour GH release were significantly decreased in obese women at before weight loss compared with non‐obese women (1.29 ± 0.12 vs. 0.60 ± 0.09 μg/L; p < 0.001 and 862 ± 90 vs. 404 ± 77 mU/24 hours; p < 0.001, respectively). Free IGF‐I and 24‐hour GH release were not inversely correlated to each other. IGFBP‐1 and −2 levels were decreased, whereas ALS, IGFBP‐3 and −4, and IGFBP‐1, −2, and −3 protease activity were similar in obese and non‐obese women. Eight of the 16 obese women achieved an average weight loss of 30 ± 5 kg during 26 to 60 weeks of dieting. After the considerable weight loss, significant differences in free IGF‐I, GH release, and IGFBP‐1 and −2 levels were no longer present between previously obese and non‐obese women.

Discussion: We showed that circulating free IGF‐I is markedly decreased in severely obese women and does not per se mediate the concomitant hyposomatotropism. The decreased levels of free IGF‐I seem to be transient and restored to normal levels after weight loss.
Association of Neuropeptide Y Receptor Y5 Polymorphisms with Dyslipidemia in Mexican Americans
Authors: Coletta Dawn K. , Schneider Jennifer , Stern Michael P. , Blangero John , DeFronzo Ralph A. , Duggirala Ravindranath , Jenkinson Christopher P.
Published: July 2008

We examined the genetic association of neuropeptide Y receptor Y5 (NPY5R) single nucleotide polymorphisms (SNPs) with measures of the insulin resistance (metabolic) syndrome. We genotyped 10 NPY5R SNPs in 439 Mexican American individuals (age = 43.3 ± 17.3 years and BMI = 30.0 ± 6.7 kg/m2) distributed across 27 pedigrees from the San Antonio Family Diabetes Study and performed association analyses using the measured genotype approach as implemented in Sequential Oligogenic Linkage Analysis Routines (SOLAR). Minor alleles for five (rs11100493, rs12501691, P1, rs11100494, rs12512687) of the NPY5R SNPs were found to be significantly (p < 0.05) associated with fasting plasma triglyceride concentrations and decreased high‐density lipoprotein concentrations. In addition, the minor allele for SNP P2 was significantly associated (p = 0.031) with a decreased homeostasis model assessment of β‐cell function (HOMA‐%β). Linkage disequilibrium between SNP pairs indicated one haplotype block of five SNPs (rs11100493, rs12501691, P1, rs11100494, rs12512687) that were highly correlated (r2 > 0.98). These preliminary results provide evidence for association of SNPs in the NPY5R gene with dyslipidemia (elevated triglyceride concentrations and reduced high‐density lipoprotein levels) in our Mexican American population.
Randomized Trial of a Multifaceted Commercial Weight Loss Program
Authors: Rock Cheryl L. , Pakiz Bilge , Flatt Shirley W. , Quintana Elizabeth L.
Published: July 2008

Objective: To test whether a commercial weight loss program promotes greater weight loss in overweight or obese women compared with control conditions and to describe the effect on plasma lipids, carotenoids, hormones, and fitness.

Research Methods and Procedures: Overweight or obese women were randomized to commercial weight loss program or control conditions (n = 35 each).

Results: At randomization, participants were 41.1 (11.4) (mean [standard deviation]) years, BMI 34.0 (3.5) kg/m2, and weight 92.0 (11.1) kg. At 6 months, change in weight by intent‐to‐treat (ITT) analysis was −7.2 (6.7) kg and −7.8% (7.2%) in the intervention group vs. −0.3 (3.9) kg and −0.3% (4.5%) in the control group (n = 35 for each; p < 0.01). One‐year ITT analysis revealed significantly greater change in weight, percent weight, BMI, and waist and hip circumferences in the intervention vs. control group. Completers at 1 year exhibited change in weight of −7.3 (10.4) kg for the intervention group (n = 32) vs. −0.7 (5.6) kg for controls (n = 33) (p < 0.01), and −7.8% (11.1%) weight change for the intervention group vs. −0.7% (6.2%) for controls (p < 0.01). High‐density lipoprotein (HDL) cholesterol concentration increased significantly in the intervention group. Fasting serum insulin decreased in the intervention but increased in the control group at 6 months (p < 0.01), remaining different at 1 year (p = 0.05).

Discussion: The commercial program successfully facilitated weight loss, which was notably maintained at 1 year, and promoted favorable changes in plasma lipid and hormone concentrations.
Dietary Fat and Weight Gain Among Women in the Nurses’ Health Study
Authors: Field Alison E. , Willett Walter C. , Lissner Lauren , Colditz Graham A.
Published: July 2008

Objective: To assess the association of dietary fat and weight gain among adult women and to investigate whether offspring of overweight parents have a greater predisposition to weight gain due to intake of dietary fat.

Research Methods and Procedures: This was an 8‐year follow‐up of 41,518 women in the Nurses’ Health Study (NHS), a population‐based, prospective cohort. The women were 41 to 68 years of age, free of cardiovascular disease, cancer, and diabetes in 1986 when “baseline” weight and diet were assessed. Eight years later (1994), changes in weight and dietary intake were assessed. Linear regression models were used to relate change in weight to fat intake and change in fat intake, using the percentage of energy from carbohydrate as the comparison, adjusted for age, BMI in 1986, leisure time physical activity, time spent sitting, percent of calories from protein, and change in percentage of calories from protein.

Results: Overall, there was a weak positive association between total fat intake (β = 0.11) and weight gain. Increases in monosaturated and polyunsaturated fat were not associated with weight gain, but increases in animal fat, saturated fat, and trans fat had a positive association with weight change. There was not strong evidence of effect modification by parental weight status (p = 0.7 to 0.8 for percentage of calories from total fat, animal fat, and vegetable fat); however, the associations were stronger among the overweight compared with leaner women (p < 0.05 for percentage of calories from each type of fat). Among overweight women, for every one percentage increase in percentage of calories from trans fat, women gained an additional 2.3 lb (95% confidence interval, 1.80 to 2.86).

Conclusion: Our results show that, overall, percent of calories from fat has only a weak positive association with weight gain; however, percentage of calories from animal, saturated, and trans fat has stronger associations. There was no clear evidence that the diet‐weight gain association was stronger among offspring of overweight parents, but dietary fat was associated with greater weight gain among overweight women.
Effect of NPY5R Antagonist MK‐0557 on Weight Regain after Very‐low‐calorie Diet‐induced Weight Loss
Authors: Erondu Ngozi , Wadden Thomas , Gantz Ira , Musser Bret , Nguyen Allison Martin , Bays Harold , Bray George , O'Neil Patrick M. , Basdevant Arnaud , Kaufman Keith D. , Heymsfield Steven B. , Amatruda John M.
Published: July 2008

Objective:To evaluate whether MK‐0557, a highly selective, orally administered neuropeptide Y Y5 receptor antagonist, could limit weight regain after very‐low‐calorie diet (VLCD)‐induced weight loss.

Research Methods and Procedures:We enrolled 502 patients 18 to 65 years of age with a BMI of 30 to 43 kg/m2. Patients were placed on a VLCD (800 kcal/d liquid diet) for 6 weeks. Patients who lost ≥6% of initial body weight (n= 359) were randomized to 52 weeks of 1 mg/d MK‐0557 or placebo and maintained on a hypocaloric diet (300 kcal below weight maintenance requirements).

Results:In randomized patients, the VLCD was associated with an average weight loss of 9.1 kg. After 12 weeks of double‐blind treatment, weight began to gradually increase for both placebo‐ and MK‐0557‐treated patients. The mean weight change (95% confidence interval) from baseline at the end of the VLCD to Week 52 was +3.1 (2.1, 4.0) and +1.5 (0.5, 2.4) kg for patients treated with placebo and MK‐0557, respectively. The difference of 1.6 kg between the two groups was significant (p= 0.014). Secondary endpoints, such as blood pressure, lipid profile, insulin, and leptin, as well as waist circumference and quality‐of‐life measurements, did not show significant differences between MK‐0557 and placebo treatments.

Discussion:Although the difference in weight regain between placebo‐ and MK‐0557‐treated patients was statistically significant, the magnitude of the effect was small and not clinically meaningful. Antagonism of the neuropeptide Y Y5 receptor is not an efficacious treatment strategy for reducing weight regain after VLCD.
Trends in Pre‐pregnancy Obesity in Nine States, 1993–2003
Authors: Kim Shin Y. , Dietz Patricia M. , England Lucinda , Morrow Brian , Callaghan William M.
Published: July 2008

Objective: Pre‐pregnancy obesity poses risks to both pregnant women and their infants. This study used a large population‐based data source to examine trends, from 1993 through 2003, in the prevalence of pre‐pregnancy obesity among women who delivered live infants.

Research Methods and Procedures: Data from the Pregnancy Risk Assessment Monitoring System in nine states were analyzed for trends in pre‐pregnancy obesity (BMI > 29.0 kg/m2) overall and by maternal demographic and behavioral characteristics. Pre‐pregnancy BMI was calculated from self‐reported weight and height on questionnaires administered after delivery, and demographic characteristics were taken from linked birth certificates. The sample of 66,221 births was weighted to adjust for survey design, non‐coverage, and non‐response, and it is representative of all women delivering a live birth in each particular state. The sampled births represented 18.5% of all births in the United States.

Results: Pre‐pregnancy obesity increased 69.3% during the study period, from 13.0% in 1993 to 1994 to 22.0% in 2002 to 2003. The percentage increase ranged from 45% to 105% for individual states. Subgroups of women with the highest prevalence of obesity in 2002 to 2003 were those who were 20 to 29 years of age, black, had three or more children, had a high school education, enrolled in Women, Infants, and Children, or were non‐smokers. However, all subgroups of women examined experienced at least a 43% increase in pre‐pregnancy obesity over this time period.

Discussion: The prevalence of pre‐pregnancy obesity is increasing among women in these nine states, and this trend has important implications for all stages of reproductive health care.
A Comparison of Adiposity Measures as Predictors of All‐cause Mortality: The Melbourne Collaborative Cohort Study
Authors: Simpson Julie A. , MacInnis Robert J. , Peeters Anna , Hopper John L. , Giles Graham G. , English Dallas R.
Published: July 2008

Objective: Our goal was to examine five different measures of adiposity as predictors of all‐cause mortality.

Research Methods and Procedures: Subjects were 16,969 men and 24,344 women enrolled between 1990 and 1994 in the Melbourne Collaborative Cohort Study (27 to 75 years of age). There were 2822 deaths over a median follow‐up period of 11 years. BMI, waist circumference, and waist‐to‐hip ratio were obtained from direct anthropometric measurements. Fat mass and percentage fat were estimated by bioelectric impedance analysis.

Results: Comparing the top quintile with the second quintile, for men there was an increased risk of between 20% and 30% for all‐cause mortality associated with each of the anthropometric measures. For women, there was an increased risk of 30% (95% confidence interval for hazard ratio, 1.1–1.6) observed for waist circumference and 50% (1.2–1.8) for waist‐to‐hip ratio, but little or no increased risk for BMI, fat mass, and percentage fat. Waist‐to‐hip ratio was positively and monotonically associated with all‐cause mortality for both men and women. There was a linear association between waist circumference and all‐cause mortality for men, whereas a U‐shaped association was observed for women.

Discussion: Measures of central adiposity were better predictors of mortality in women in the Melbourne Collaborative Cohort Study compared with measures of overall adiposity. We recommend measuring waist and hip circumferences in population studies investigating the risk of all‐cause mortality associated with obesity. The use of additional measures such as bioelectric impedance is not justified for this outcome.
Field Validation of the MTI Actigraph and BodyMedia Armband Monitor Using the IDEEA Monitor
Authors: Welk Gregory J. , McClain James J. , Eisenmann Joey C. , Wickel Eric E.
Published: July 2008

Objective: Accelerometers offer considerable promise for improving estimates of physical activity (PA) and energy expenditure (EE) in free‐living subjects. Differences in calibration equations and cut‐off points have made it difficult to determine the most accurate way to process these data. The objective of this study was to compare the accuracy of various calibration equations and algorithms that are currently used with the MTI Actigraph (MTI) and the Sensewear Pro II (SP2) armband monitor.

Research Methods and Procedures: College‐age participants (n = 30) wore an MTI and an SP2 while participating in normal activities of daily living. Activity patterns were simultaneously monitored with the Intelligent Device for Estimating Energy Expenditure and Activity (IDEEA) monitor to provide an accurate estimate (criterion measure) of EE and PA for this field‐based method comparison study.

Results: The EE estimates from various MTI equations varied considerably, with mean differences ranging from −1.10 to 0.46 METS. The EE estimates from the two SP2 equations were within 0.10 METS of the value from the IDEEA. Estimates of time spent in PA from the MTI and SP2 ranged from 34.3 to 107.1 minutes per day, while the IDEEA yielded estimates of 52 minutes per day.

Discussion: The lowest errors in estimation of time spent in PA and the highest correlations were found for the new SP2 equation and for the recently proposed MTI cut‐off point of 760 counts/min (Matthews, 2005). The study indicates that the Matthews MTI cut‐off point and the new SP2 equation provide the most accurate indicators of PA.
Association of Childhood Sexual Abuse With Obesity in a Community Sample of Lesbians
Authors: Aaron Deborah J. , Hughes Tonda L.
Published: July 2008

Objective: Our goal was to examine the association between childhood sexual abuse (CSA) and obesity in a community‐based sample of self‐identified lesbians.

Research Methods and Procedures: A diverse sample of women who self‐identified as lesbian was recruited from the greater Chicago metropolitan area. Women (n = 416) were interviewed about sexual abuse experiences that occurred before the age of 18. Self‐reported height and weight were used to calculate BMI and categorize women as normal‐weight (<25.0 kg/m2), overweight (25.0 to 29.9 kg/m2), obese (30.0 to 39.9 kg/m2), or severely obese (≥40 kg/m2). The relationship between CSA and BMI was examined using multinomial logistic regression analysis.

Results: Overall, 31% of women in the sample reported CSA, and 57% had BMI ≥25.0 kg/m2. Mean BMI was 27.8 (±7.2) kg/m2 and was significantly higher among women who reported CSA than among those who did not report CSA (29.4 vs. 27.1, p < 0.01). CSA was significantly related to weight status; 39% of women who reported CSA compared with 25% of women who did not report CSA were obese (p = 0.004). After adjusting for age, race/ethnicity, and education, women who reported CSA were more likely to be obese (odds ratio, 1.9; 95% confidence interval, 1.1–3.4) or severely obese (odds ratio, 2.3; 95% confidence interval, 1.1–5.2).

Discussion: Our findings, in conjunction with the available literature, suggest that CSA may be an important risk factor for obesity. Understanding CSA as a factor that may contribute to weight gain or act as a barrier to weight loss or maintenance in lesbians, a high‐risk group for both CSA and obesity, is important for developing successful obesity interventions for this group of women.
Fat Stigmatization in Television Shows and Movies: A Content Analysis
Authors: Himes Susan M. , Thompson J. Kevin
Published: July 2008

Objective: To examine the phenomenon of fat stigmatization messages presented in television shows and movies, a content analysis was used to quantify and categorize fat‐specific commentary and humor.

Research Methods and Procedures: Fat stigmatization vignettes were identified using a targeted sampling procedure, and 135 scenes were excised from movies and television shows. The material was coded by trained raters. Reliability indices were uniformly high for the seven categories (percentage agreement ranged from 0.90 to 0.98; kappas ranged from 0.66 to 0.94).

Results: Results indicated that fat stigmatization commentary and fat humor were often verbal, directed toward another person, and often presented directly in the presence of the overweight target. Results also indicated that male characters were three times more likely to engage in fat stigmatization commentary or fat humor than female characters.

Discussion: To our knowledge, these findings provide the first information regarding the specific gender, age, and types of fat stigmatization that occur frequently in movies and television shows. The stimuli should prove useful in future research examining the role of individual difference factors (e.g., BMI) in the reaction to viewing such vignettes.
The Q121/Q121 Genotype of ENPP1/PC‐1 Is Associated with Lower BMI in Non‐diabetic Whites
Authors: Prudente Sabrina , Chandalia Manisha , Morini Eleonora , Baratta Roberto , Dallapiccola Bruno , Abate Nicola , Frittitta Lucia , Trischitta Vincenzo
Published: July 2008

This study investigated the role of the ENPP1/PC‐1 gene K121Q polymorphism in predicting BMI (kg/m2) in non‐diabetic individuals. Three independent samples (n = 631, n = 304, and n = 505) of adult whites were analyzed. Selection criteria were fasting plasma glucose level <126 mg/dL, absence of severe obesity (BMI ≥40 kg/m2), and lack of treatment known to modulate BMI. In Sample 1, BMI values were different in individuals carrying the K121/K121 (KK), K121/Q121 (KQ), and Q121/Q121 (QQ) genotypes (25.5 ± 4.3, 25.3 ± 4.1, and 22.8 ± 2.5 kg/m2, respectively (adjusted p = 0.022); BMI values in Samples 2 and 3 also tended to be different, although the differences, after adjustment for age and sex, did not reach statistical significance. When data were pooled, BMI values were 25.8 ± 4.4, 25.6 ± 4.4, and 23.6 ± 3.3 kg/m2 in KK, KQ, and QQ individuals (adjusted p = 0.029). According to a recessive model, QQ individuals had lower BMI values than KK and KQ individuals combined (23.6 ± 3.3 kg/m2 vs. 25.7 ± 4.4 kg/m2; adjusted p = 0.008). These data suggest that the QQ genotype of the ENPP1/PC‐1 gene is associated with lower BMI. If similar results are confirmed in prospective studies, the K121Q polymorphism may help identify people at risk for obesity.
The SH2B Gene is Associated with Serum Leptin and Body Fat in Normal Female Twins
Authors: Jamshidi Yalda , Snieder Harold , Ge Dongliang , Spector Tim D. , O'Dell Sandra D.
Published: July 2008

Src‐homology‐2 (SH2)‐B, a Janus tyrosine kinase 2‐interacting protein, has been identified recently as a key regulator of leptin and insulin sensitivity, glucose homeostasis, and body weight in mice. The aim of this study was to determine whether single‐nucleotide polymorphisms (SNPs) in the human SH2B gene are associated with these variables. A tagging SNP (tSNP), Ala484Thr (rs7498665), was selected to represent five common SNPs (minor allele frequency > 0.05) in perfect linkage disequilibrium in a 16‐kb region encompassing the SH2B gene. The tSNP was genotyped in 2455 white female twins (mean age, 47.4 ± 12.6 years) from the St. Thomas’ United Kingdom Adult Twin Registry (Twins United Kingdom). Ala484Thr (minor allele frequency, 0.38) was associated with serum leptin, total fat, waist circumference, and body weight (P = 0.02 to 0.04). The coding SNP has no predicted effect on protein structure or function and is likely to be in linkage disequilibrium with an as‐yet unidentified functional variant in the SH2B gene. Our results support a role for SH2‐B in modulating the regulation of body weight and fat by leptin in this female population. If SH2‐B signaling is attenuated in diet‐induced obesity, it could become a target for drug‐induced leptin sensitization.
Short‐Term Effects of a “Health‐At‐Every‐Size” Approach on Eating Behaviors and Appetite Ratings
Authors: Provencher Véronique , Bégin Catherine , Tremblay Angelo , Mongeau Lyne , Boivin Sonia , Lemieux Simone
Published: July 2008

Objective: To assess the effects of a “Health‐At‐Every‐Size” (HAES) intervention on eating behaviors and appetite ratings in 144 premenopausal overweight women.

Research Methods and Procedures: Women were randomly assigned to one of the 3 groups: HAES group, social support (SS) group, and control group (N = 48 in each group). Interventions were conducted over a 4‐month period, and measurements were taken before and after this period. Eating behaviors (cognitive dietary restraint, disinhibition, and susceptibility to hunger) were evaluated by the Three‐Factor Eating Questionnaire. Appetite ratings (desire to eat, hunger, fullness, and prospective food consumption) were assessed by visual analogue scales before and after a standardized breakfast.

Results: More important decreases in susceptibility to hunger and external hunger were observed in the HAES group when compared with the SS group (p = 0.05, for susceptibility to hunger) and the control group (p = 0.02 and p = 0.005, for susceptibility to hunger and external hunger, respectively). In addition, women from the HAES group had more important decreases in postprandial area under the curve for desire to eat (p = 0.02) and hunger (p = 0.04) when compared with the control group. The change in the desire to eat noted in the HAES group was also different from the one observed in SS group (p = 0.02). Women from the HAES group experienced significant weight loss at 4 months (−1.6 ± 2.5 kg, p < 0.0001), which did not differ significantly from the SS and control groups (p = 0.09). An increase in flexible restraint was significantly related to a greater weight loss in both HAES and SS groups (r = −0.39, p < 0.01; and r = −0.37, p < 0.05, respectively). A decrease in habitual susceptibility to disinhibition was also associated with a greater weight loss in HAES and control groups (r = 0.31, p < 0.05; and r = 0.44, p < 0.05, respectively).

Discussion: These results suggest that a HAES intervention could have significant effects on eating behaviors and appetite ratings in premenopausal overweight women, when compared with an SS intervention or a control group.
Role of peroxisome-proliferator-activated receptor β/δ (PPARβ/δ) in gastrointestinal tract function and disease
Authors: Peters Jeffrey M. , Hollingshead Holly E. , Gonzalez Frank J.
Published: July 2008

PPARβ/δ (peroxisome-proliferator-activated receptor β/δ) is one of three PPARs in the nuclear hormone receptor superfamily that are collectively involved in the control of lipid homoeostasis among other functions. PPARβ/δ not only acts as a ligand-activated transcription factor, but also affects signal transduction by interacting with other transcription factors such as NF-κB (nuclear factor κB). Constitutive expression of PPARβ/δ in the gastrointestinal tract is very high compared with other tissues and its potential physiological roles in this tissue include homoeostatic regulation of intestinal cell proliferation/differentiation and modulation of inflammation associated with inflammatory bowel disease and colon cancer. Analysis of mouse epithelial cells in the intestine and colon has clearly demonstrated that ligand activation of PPARβ/δ induces terminal differentiation. The PPARβ/δ target genes mediating this effect are currently unknown. Emerging evidence suggests that PPARβ/δ can suppress inflammatory bowel disease through PPARβ/δ-dependent and ligand-independent down-regulation of inflammatory signalling. However, the role of PPARβ/δ in colon carcinogenesis remains controversial, as conflicting evidence suggests that ligand activation of PPARβ/δ can either potentiate or attenuate this disease. In the present review, we summarize the role of PPARβ/δ in gastrointestinal physiology and disease with an emphasis on findings in experimental models using both high-affinity ligands and null-mouse models.
Immune regulatory cells: circulating biomarker factories in cardiovascular disease
Authors: Pasterkamp Gerard , Versteeg Dik , de Kleijn Dominique P. V.
Published: July 2008

TLRs (Toll-like receptors) are the first line of defence of the innate immune system. These receptors recognize not only exogenous but also endogenous ligands that are expressed following arterial injury and atherosclerotic disease. Expression of TLR2 and TLR4 is observed in macrophages and different vascular cells and is increased in atherosclerotic disease. It is suggested that TLR expression and functional responsiveness following ligation could serve as biomarkers for atherosclerotic disease progression. Recently published research papers support the concept that the TLRs are fast responders upon arterial injury. In the present issue of Clinical Science, Ishikawa and co-workers provide new evidence emerges that points to the potential prognostic properties of the TLRs.
Exercise Prescription for Dysphagia: Intensity and Duration Manipulation
Authors: Sapienza Christine , Wheeler-Hegland Karen , Stewart Kim , Nocera Joseph
Published: July 2008

This paper briefly reviews information available on exercise stimulus intensity and its interaction with stimulus duration, as well as reviews the current information on different dysphagia treatment modalities as they relate to treatment intensity and duration. The available literature in this area suggests that exercise modalities are distinct and different with regard to the metabolic pathways accessed as a function of both stimulus intensity and duration. Defining treatment prescriptions for dysphagia is difficult at this time, however, because only limited data on stimulus duration or intensity is available for existing indirect and direct treatments. Acknowledgment of exercise physiology paradigms and mechanisms of muscle response to treatment is critical to design of rehabilitation protocols.
Overview of Results From the Largest Clinical Trial for Dysphagia Treatment Efficacy
Authors: Robbins JoAnne , Hind Jacqueline
Published: July 2008

Information presented herein provides an overview of the largest randomized clinical trial ever completed in dysphagia. The two-part sequential randomized clinical trial studied the effect of two common dysphagia interventions (chin tuck and thickened liquids) for immediate prevention of aspiration during videofluorographic assessment and also for the incidence of pneumonia at 3-months for patients with Parkinson's disease and/or dementia. Results indicated that thickened liquids (nectar-thick or honey-thick) prevented aspiration during the radiographic study more frequently than chin-down posture; however, both interventions were equally successful at preventing pneumonia. Adverse events such as urinary tract infection and dehydration were more common with thickened liquids. Median length of hospital stay due to pneumonia was three times longer for patients drinking honey-thick liquids compared to nectar-thick and chin-tuck arms of the study. Several important secondary outcomes are discussed as well as implications for clinical practice. The reader is encouraged to refer to other published works for detailed information that is highlighted in this overview.
What Speech-Language Pathologists and Caregivers Can Do to Encourage the Eating Process
Authors: Cooke Paul
Published: July 2008

This article highlights key factors individuals with dysphagia face on a daily basis and discusses ways in which speech-language pathologists, other health care professionals, and family members can encourage these individuals to eat and drink. The present focus is on those patients who are partially or totally eating and drinking orally. They may or may not be feeding themselves and may reside in a variety of settings, including: their home, with family members, at various levels within the hospital system, in a rehabilitation facility, and/or in a nursing home. Various proactive strategies are provided that will benefit caregivers assisting individuals with dysphagia.
Continuing Equivalence: Is There an End to the Story?
Authors: Williams Roger L. , Shah Vinod P.
Published: July 2008

For many active pharmaceutical ingredients and their corresponding drug products, the possibility of a single global system of harmonised bioequivalence and pharmaceutical equivalence requirements for first-entry and interchangeable multi-source drug products may be considered. The topic should be of interest to all manufacturers, to practitioners and patients as well, and to government policy-makers. In an era when substandard, counterfeit, and adulterated medicines are increasingly available, the topic requires careful consideration.
Improved adhesion of interconnected TiO2 nanofiber network on conductive substrate and its application in polymer photovoltaic devices
Authors: Zhu Rui , Jiang Chang-Yun , Liu Xi-Zhe , Liu Bin , Kumar Abhishek , Ramakrishna S.
Published: July 2008

The application of electrospun ceramic nanofibers is limited in electronic devices due to their poor adhesion on conductive substrates. In this regard, a simple method is developed by inserting an ultrathin surface treatment layer between TiO2 nanofiber mats and a conductive substrate to enhance interfacial adhesion. Polymer hybrid photovoltaic devices based on the TiO2 nanofibrous network were fabricated and investigated. Improved device performance was obtained by TiCl4 treatment and interfacial modification for the TiO2 nanofibers, as compared to those without any treatment.
Cluster-variation approximation for a network-forming lattice-fluid model
Authors: Buzano C. , De Stefanis E. , Pretti M.
Published: July 2008

We consider a three-dimensional lattice model of a network-forming fluid, which has been recently investigated by Girardi et al. by means of Monte Carlo simulations [J. Chem. Phys. 126, 064503 (2007)], with the aim of describing water anomalies. We develop an approximate semianalytical calculation, based on a cluster-variation technique, which turns out to reproduce almost quantitatively different thermodynamic properties and phase transitions determined by the Monte Carlo method. Nevertheless, our calculation points out the existence of two different phases characterized by long-range orientational order, and of critical transitions between them and to a high-temperature orientationally disordered phase. Also, the existence of such critical lines allows us to explain certain “kinks” in the isotherms and isobars determined by the Monte Carlo analysis. The picture of the phase diagram becomes much more complex and richer, though unfortunately less suitable to describe real water.
Efficiency enhancement of polymer photovoltaic devices using thieno-thiophene based copolymers as nucleating agents for polythiophene crystallization
Authors: Bechara R. , Leclerc N. , Lévêque P. , Richard F. , Heiser T. , Hadziioannou G.
Published: July 2008

A copolymer including thieno-thiophene units (DHPT3) has been synthesized and used as crystallization nucleating agent in the active layer of poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl C61-butyric acid methyl ester (PCBM) bulk heterojunction photovoltaic devices. We demonstrate in this work that the addition of DHPT3 in P3HT/PCBM thin films induces a marked structural ordering of the polythiophene phase. This structural order enhances the charge carrier transport properties and enlarges the active layer absorption spectrum. The photovoltaic devices power conversion efficiency prior to thermal annealing could be enhanced by a factor of 2 by adding 5% of DHPT3 into the blend.
Nonlinear optical property calculations of polyynes with long-range corrected hybrid exchange-correlation functionals
Authors: Song Jong-Won , Watson Mark A. , Sekino Hideo , Hirao Kimihiko
Published: July 2008

Polarizabilities (α), second-hyperpolarizabilities (γ), and the γ scaling factors (c) of polyynes [H–(C≡C)n–H, n=1–8] were evaluated using the long-range corrected (LC) density functional theory (DFT) and LC-DFT with a short-range Gaussian attenuation (LCgau), as well as high quality wavefunction methods. We show that the c values obtained from LC- and LCgau-DFT are consistent with those from CCSD(T) calculations. Furthermore, the polyyne c values we obtained are seen to be smaller than the c values derived from previously calculated polyene γ values [Sekino et al., J. Chem. Phys. 126, 014107 (2007)] in all the methods we consider. We compare our results with those obtained experimentally [Shepkov et al., J. Chem. Phys. 120, 6807 (2004).] from end-capped polyynes [i-Pr3Si—(C≡C)n—Sii-Pr3], which show larger c values for polyynes than polyenes. Our α and γ calculations with i-Pr3Si—(C≡C)n—Sii-Pr3 (n=4,5,6, and 8) show that i-Pr3Si— may participate in π molecular orbital delocalization, which can unexpectedly affect the c value. We also confirm the importance of molecular geometry in these nonlinear optical calculations. We find that while LC- and LCgau-DFT excellently reproduce experimental geometries and bond length alternation (BLA), MP2 optimized geometries have a BLA that is too short to be used for accurate α and γ calculations.
The role of γ-iron nanoparticulates in the growth of carbon nanotubes
Authors: Khasanov Airat , He Jian , Gaillard Jay , Yang Keqin , Rao Apparao M. , Cameron C. Michelle , Schmeltzer J. M. , Stevens John G. , Nath Amar
Published: July 2008

Carbon nanotubes (∼200nm diameter) are grown by chemical vapor deposition using catalytic iron particles. Mössbauer spectroscopy enables differentiation among relatively large Fe3C, α-Fe, and nanosized superparamagnetic fcc γ-Fe particles. The antiferromagnetic configuration of γ-Fe nanoparticles yields a significant fraction of uncompensated spins, producing a weak ferromagnetism that allows estimation of size (2–3nm) via magnetization in zero field versus variable field cooling. This property of γ-Fe nanoparticles has not been previously employed. We propose that the surfaces of 200nm iron carbide particles are covered with nanosized γ-Fe and graphitized carbon that participate in the catalytic growth of nanotubes.
Bayesian estimates of free energies from nonequilibrium work data in the presence of instrument noise
Authors: Maragakis Paul , Ritort Felix , Bustamante Carlos , Karplus Martin , Crooks Gavin E.
Published: July 2008

The Jarzynski equality and the fluctuation theorem relate equilibrium free energy differences to nonequilibrium measurements of the work. These relations extend to single-molecule experiments that have probed the finite-time thermodynamics of proteins and nucleic acids. The effects of experimental error and instrument noise have not been considered previously. Here, we present a Bayesian formalism for estimating free energy changes from nonequilibrium work measurements that compensates for instrument noise and combines data from multiple driving protocols. We reanalyze a recent set of experiments in which a single RNA hairpin is unfolded and refolded using optical tweezers at three different rates. Interestingly, the fastest and farthest-from-equilibrium measurements contain the least instrumental noise and, therefore, provide a more accurate estimate of the free energies than a few slow, more noisy, near-equilibrium measurements. The methods we propose here will extend the scope of single-molecule experiments; they can be used in the analysis of data from measurements with atomic force microscopy, optical, and magnetic tweezers.
Three-dimensional atom probe analysis of green- and blue-emitting InxGa1−xN∕GaN multiple quantum well structures
Authors: Galtrey M. J. , Oliver R. A. , Kappers M. J. , Humphreys C. J. , Clifton P. H. , Larson D. , Saxey D. W. , Cerezo A.
Published: July 2008

The three-dimensional atom probe has been used to characterize green- and blue-emitting InxGa1−xN∕GaN multiple quantum well structures with subnanometer resolution over a 100nm field of view. The distribution of indium in InxGa1−xN samples with different compositions is analyzed. No evidence is found wherein the indium distribution deviates from that of a random alloy, which appears to preclude indium clustering as the cause of the reported carrier localization in these structures. The upper interface of each quantum well layer is shown to be rougher and more diffuse than the lower interface, and the existence of monolayer steps in the upper interfaces is revealed. These steps could effectively localize carriers at room temperature. Indium is shown to be present in the GaN barrier layers despite the absence of indium precursor flux during barrier layer growth. A strong evidence is produced to support a mechanism for the presence of indium in these layers, namely, that a layer of indium forms on the surface of the growing InxGa1−xN quantum well, and this layer then acts as a source of indium during GaN barrier layer growth.
Unexpectedly low thermal conductivity in natural nanostructured bulk Ga2Te3
Authors: Kurosaki Ken , Matsumoto Hideaki , Charoenphakdee Anek , Yamanaka Shinsuke , Ishimaru Manabu , Hirotsu Yoshihiko
Published: July 2008

Here we introduce a promising thermoelectric material: Ga2Te3 with unexpectedly low thermal conductivity, in which certain kinds of superlattice structures naturally form. Two-dimensional vacancy planes with approximately 3.5nm intervals exist in Ga2Te3, scattering phonons efficiently and leading to a very low thermal conductivity, comparable to its calculated minimum. Ga2Te3 and related materials hold great promise in the field of thermoelectrics.
Long-lifetime thin-film encapsulated organic light-emitting diodes
Authors: Wong F. L. , Fung M. K. , Tao S. L. , Lai S. L. , Tsang W. M. , Kong K. H. , Choy W. M. , Lee C. S. , Lee S. T.
Published: July 2008

Multiple fluorocarbon (CFx) and silicon nitride (Si3N4) bilayers were applied as encapsulation cap on glass-based organic light-emitting diodes (OLEDs). When CFx/Si3N4 bilayers were deposited onto the OLED structure, the devices showed performance worse than one without any encapsulation. The adverse effects were attributed to the damage caused by reaction species during the thin-film deposition processes. To solve this problem, a CuPc interlayer was found to provide effective protection to the OLED structure. With a structure of CuPc/(CFx/Si3N4)×5, the encapsulated device showed an operation lifetime over 8000 h (higher than 80% of that achieved with a conventional metal encapsulation).
On the mechanism of photoinduced phase transitions in ternary liquid crystal systems near thermal equilibrium
Authors: Quevedo Wilson , Petri Marcel , Busse Gerhard , Techert Simone
Published: July 2008

According to their phase diagram, polyalkyl glycol ether dissolved in ternary solutions (water, alcane, and cyclohexane) lead to the formation of either liquid crystal phases or microemulsion phases. By photosensitization of the ternary system with laser dyes and choosing the adequate concentration and temperature conditions of these lyotropic systems, it is possible to photoinduce the phase transitions from the microemulsion phase to the liquid crystal phase (and vice versa). The phototransformation conditions were chosen in such a way that the system is in thermal equilibrium during the entire phase transition. The method of photo small angle x-ray scattering has been applied to investigate the mechanism of photoinduced phase transition. Spectroscopically, the mechanism of photoinduced phase transition has been characterized by optical absorption and emission techniques.
Ab initio study of charge transport of hydrogen functionalized palladium wires
Authors: Zhao Zhen , Dunietz Barry D.
Published: July 2008

We present ab initio calculations of transport properties of palladium wires in the presence of hydrogen. Detailed investigations have been conducted with a pure palladium wire and with opening a gap inside the wire in which the transition between point contact regime and tunneling regime occurs. The effect of the presence of hydrogen in the gap is studied for different ranges of the gap size. The hydrogen mediated transport in the contact and tunneling regimes of the gap are analyzed and compared. It is predicted that only in large enough distances the hydrogen presence increases the conductance. The effect of additional hydrogen molecules on the gap is also studied.
Using circularly polarized luminescence to probe exciton coherence in disordered helical aggregates
Authors: Spano Frank C. , Meskers Stefan C. J. , Hennebicq Emanuelle , Beljonne David
Published: July 2008

Circularly polarized emission from helical MOPV4 aggregates is studied theoretically based on a Hamiltonian including excitonic coupling, exciton phonon coupling, and site disorder. The latter is modeled via a Gaussian distribution of site energies. The frequency dependence of the circularly polarized luminescence dissymmetry glum(ω) contains structural information about the low-energy-neutral (excitonic) polaron from which emission originates. Near the 0-0 emission frequency, glum(ω) provides a measure of the exciton coherence length, while at lower energies, in the vicinity of the sideband frequencies, glum(ω) probes the polaron radius. The present work focuses on how the 0-0 dissymmetry, glum0-0, relates to the emitting exciton’s coherence function, from which the coherence length is deduced. In the strong disorder limit where the exciton is localized on a single chromophore, glum0-0 is zero. As disorder is reduced and the coherence function expands, ∣glum0-0∣ increases more rapidly than the sideband dissymmetries, resulting in a pronounced surge in glum(ω) near the 0-0 transition frequency. The resulting spectral shape of glum(ω) is in excellent agreement with recent experiments on MOPV4 aggregates. In the limit of very weak disorder, corresponding to the motional narrowing regime, the coherence function extends over the entire helix. In this region, glum0-0 undergoes a surprising sign reversal but only for helices which are between n+12 and n+1 complete turns (n=0,1,…). This unusual sign change is due to the dependence of the rotational line strength on long-range exciton coherences which are also responsible for a heightened sensitivity of glum(ω) to long-range excitonic coupling.
Electrical manipulation of magnetic anisotropy in the composite of liquid crystals and ferromagnetic nanorods
Authors: Lin Tsung-Ju , Chen Chin-Chang , Lee Wenchao , Cheng Soofin , Chen Yang-Fang
Published: July 2008

A simple and general approach for manipulating magnetic field at room temperature by means of electric fields is reported. Our design involves the fabrication of liquid crystal devices compounded with built-in ferromagnetic nanorods. It is discovered that magnetic nanorods can be well aligned along the orientation of liquid crystal molecules. Electrically assisted magnetic anisotropy rotation has been demonstrated through the effect of the electrical manipulation of magnetic nanorods. In view of the well established technology of liquid crystals display, our results shown here pave a key step for the practical application of distinct device paradigms based on magnetoelectric effect, including electric field-controlled magnetic data storage, transducers, attenuators, and spintronics.