bluuebunny/crossref_metadata_2025 huggingface dataset:
Betaine (Trimethylglycine) as a nutritional agent prevents oxidative stress after chronic ethanol consumption in pancreatic tissue of rats
Authors: Kanbak Gungör , Dokumacioglu Ali , Tektas Aysegul , Kartkaya Kazim , Erden Inal Mine
Published: January 2010

In this study, we investigated the free radical-mediated cytotoxic effects of chronic ethanol consumption on the pancreatic tissue and a possible cytoprotective effect of betaine as a methyl donor and an important participant in the methionine cycle. Twenty-four male Wistar rats were divided into control, ethanol, and ethanol+betaine groups. Prior to sacrifice, all groups were fed 60 mL/diet per day for two months. Rats in the ethanol group were fed with ethanol 8 g/kg/day. The ethanol+betaine groups were fed ethanol plus betaine (0.5 % w/v). Malondialdehyde levels and adenosine deaminase, superoxide dismutase, and xanthine oxidase activities were determined in pancreatic tissues of rats. Compared to control group, MDA levels increased significantly in the ethanol group (p<0.05). MDA levels in the ethanol+betaine group were significantly decreased compared to the ethanol group (p<0.05). ADA activity in the ethanol+betaine group decreased significantly when compared to the ethanol group (p<0.05). XO activities in ethanol-fed rats were decreased significantly compared to the control group (p<0.05). XO activity in the betaine group was increased significantly (p<0.05) compared to the ethanol group. SOD activity in the ethanol group decreased significantly compared to control group (p<0.001). SOD activity in the ethanol+betaine group decreased significantly (p<0.05) compared to the control group. We think that betaine, as a nutritional methylating agent, may be effective against ethanol-mediated oxidative stress in pancreatic tissue.
Fasting plasma carotenoids concentrations in Crohn’s and pancreatic cancer patients compared to control subjects
Authors: Drai  , Borel  , Faure  , Galabert  , Le Moël  , Laromiguière  , Fayol
Published: January 2010

Carotenoids are colored molecules that are widespread in the plant kingdom, but animals cannot synthesize them. Carotenes are long, apolar molecules which require fully functioning digestive processes to be absorbed properly. Hence they could be interesting markers of intestinal absorption and digestion. Indeed, only few tests are available to assess these processes and only the D-xylose tolerance test is routinely used. However D-xylose is a sugar that tests only the absorption of water-soluble compounds and it only tests duodenal absorption. In this study, we have evaluated carotenoids as markers of digestion and absorption. We compared fasting plasma carotenoids concentrations in 21 control subjects, 20 patients with Crohn’s disease, and 18 patients with pancreatic cancer. Crohn’s disease alters intestinal absorption while pancreatic cancer decreases pancreatic enzyme secretion thus impairing digestion. Results show that all carotenoids are significantly lower in Crohn’s and cancer patients as compared to control subjects and the multifactorial analysis shows that this decrease is mostly independent of dietary intake. Interestingly, maldigestion as seen in pancreatic cancer more strongly influences plasma lutein and lycopene concentrations while malabsorption in Crohn’s disease acts on other carotenoids. Thus carotenoids could be interesting alternatives for testing and following patients that are suspected of having malabsorption or maldigestion syndromes.
Pyridoxine increases nitric oxide biosynthesis in human platelets
Authors: Wu Yong , Liu Yuan , Han Yi , Cui Bota , Mi Qiongyu , Huang Yan , Wang Li , Jiang Qin , Chen Qi , Liu Naifeng , Ferro Albert , Ji Yong
Published: January 2010

Activation and aggregation of platelets are key events in the pathophysiology of thrombotic diseases. There is increasing evidence that platelet-derived nitric oxide (NO) exerts important anti-platelet actions. Pyridoxine may have beneficial therapeutic effects in cardiovascular disease states, and has previously been shown to increase endothelial NO biosynthesis. The aims of the present study were firstly to determine in vitro whether pyridoxine can increase platelet NO synthesis, and secondly to investigate the mechanism by which it does this. Platelets isolated from blood taken from healthy subjects were treated with pyridoxine or vehicle. Platelet aggregation was measured by Born aggregometry. Intraplatelet cyclic guanosine-3’,5’-monophosphate (cGMP, an index of bioactive NO) was measured by radioimmunoassay. Serine-1177-specific phosphorylation of NO synthase type 3 (NOS-3) and phosphorylation of protein kinase Akt were determined in platelets by Western blotting. Phosphatidylinositol 3-kinase (PI3K) activity in platelets was ascertained by homogeneous time-resolved fluorescence (HTRF) assay. Our results showed that pyridoxine largely inhibited the aggregation of platelets in response to adenosine diphosphate (ADP) or thrombin and increased bioactive NO. It also increased NOS-3 phosphorylation on serine-1177, and increased Akt serine phosphorylation. PI3K activity was augmented by pyridoxine, an effect inhibited by the specific PI3K antagonist LY294002. In conclusion, pyridoxine is effective in elevating platelet NO biosynthesis, through improving PI3K activity and hence downstream Akt phosphorylation, and in turn serine-1177 phosphorylation of NOS-3. These data reveal a novel mechanism by which NOS-3 activity can be regulated in platelets.
Arbeitsgedächtnis: Vergangenheit, Gegenwart und Zukunft eines theoretischen Konstruktes
Authors: Berti Stefan
Published: January 2010

Zusammenfassung. Arbeitsgedächtnis als theoretisches Konstrukt bietet einen Rahmen, das Speichern und Verwalten von Informationen für kognitive Funktionen und damit verbundener Ziele zu konzeptualisieren. Problematisch kann aber sein, dass die verschiedenen theoretischen Ansätze vor allem die Unterschiede zwischen Modellen betonen, so dass nicht immer klar ist, was der gemeinsame Kern der Arbeitsgedächtnisforschung ist und worin die Weiterentwicklung der Arbeitsgedächtnisperspektive gerade auch im Vergleich zum Kurzzeitgedächtniskonzept liegt. Im Anschluss an eine Analyse der Entwicklung des Arbeitsgedächtnisbegriffs wird eine Position dargelegt, die betont, dass im Kern des Arbeitsgedächtnisses die Interaktion von Prozessen der Bereitstellung von Information mit den darauf aufbauenden kognitiven Prozessen liegt. Auf Basis dieser Analyse lässt sich darüber hinaus feststellen, dass die Unterschiede der verschiedenen Modellvorstellungen geringer sind, als es den Anschein hat.
Zur Interaktion von verbalem Kurzzeitgedächtnis und Sprachverarbeitung: Belege aus der kognitiven Neuropsychologie
Authors: Bormann Tobias
Published: January 2010

Zusammenfassung. Der vorliegende Beitrag diskutiert Daten neurologischer Patienten, die für Modellvorstellungen des verbalen Kurzzeit- oder Arbeitsgedächtnisses relevant sind. Fallstudien im Paradigma der kognitiven Neuropsychologie stützten anfänglich das Arbeitsgedächtnismodell von Baddeley. In weiteren Studien fanden sich in klinischen Populationen allerdings ausgeprägte Einflüsse von lexikalischen und semantisch-konzeptuellen Langzeitrepräsentationen auf die unmittelbaren Behaltensleistungen. Dies führte zu neuen Ansätzen, welche das Nachsprechen in bestehenden Modellen der normalen Sprachverarbeitung ansiedeln. Der Beitrag präsentiert relevante klinische Studien und diskutiert Vor- und Nachteile der bestehenden Modelle.
Interferenz im Arbeitsgedächtnis:Ein formales Modell
Authors: Oberauer Klaus , Kliegl Reinhold
Published: January 2010

Zusammenfassung. Die Autoren stellen ein theoretisches Modell des Arbeitsgedächtnisses vor, das auf neuronalen Netzwerkmodellen beruht. Inhalte des Arbeitsgedächtnisses sind durch verteilte Muster neuronaler Aktivität repräsentiert. Bindungen zwischen Merkmalen eines Elements, und zwischen Inhaltselementen und ihren Kontexten, werden durch synchrones Feuern von Einheiten hergestellt. Daraus folgt das Prinzip der Interferenz durch Merkmalsüberschreibung als ein Faktor, der die Arbeitsgedächtniskapazität begrenzt. Erste Evidenz für dieses Prinzip liefern Experimente, in denen die Wiedergabe von Wörtern durch das Ausmaß an Phonemüberlappung mit Distraktoren manipuliert werden konnte. Eine mathematische Formulierung des Modells wird exemplarisch auf Zeit-Genauigkeits-Funktionen von jungen und alten Erwachsenen bei einer arithmetischen Arbeitsgedächtnisaufgabe angewandt. Diese Anwendung illustriert die Möglichkeit, mithilfe von nicht-linearen Mehrebenen-Regressionsmodellen (NLME-Modellen) theoretisch gehaltvolle Modelle simultan auf Gruppenmittelwerte und interindividuelle Unterschiede anzuwenden.
Evolution of long‐term land subsidence near Mexico City: Review, field investigations, and predictive simulations
Authors: Ortiz‐Zamora Dalia , Ortega‐Guerrero Adrian
Published: January 2010

Aquitard consolidation in the Chalco Plain is the most recent of a series of major land subsidence problems near Mexico City caused by leaky‐aquifer pumping and involving a complex distribution of basalt flows within a lacustrine sequence. This study first conducted a ground magnetic survey combined with lithologic logs to map the extension of basalts. Then it assessed the evolution of ground surface elevations and updated hydraulic heads in the aquifer and aquitard in order to verify the accuracy of previous simulations and develop new predictions on land subsidence employing a one‐dimensional, nonlinear, groundwater flow‐consolidation model. Results show the presence of shallow basalts that extend from Sierra Santa Catarina into the Chalco Plain, causing a differential consolidation that controls both the distribution of large‐scale fractures in the aquitard and the shape of a new lake. Cumulative land subsidence in the center of the Chalco Plain reached 13 m in 2006, thus closely matching previous numerical estimations. Since 1985, the ground surface decline has continued at a rate of ∼0.40 m/yr, while the potentiometric surface decline in the aquifer proceeds at an average rate of ∼1.5 m/yr, indicating that the flow system has not yet reached steady‐state conditions. Numerical predictions show that under current pumping rates, where the aquitard is 300 m, total land subsidence will reach ∼19 m by the year 2020; while where the aquitard is 140 m thick, total land subsidence will reach ∼12 m, and increase the risk of flooding and aquitard fracturing for nearby urban centers.
Persistent englacial drainage features in the Greenland Ice Sheet
Authors: Catania G. A. , Neumann T. A.
Published: January 2010

Surface melting on the Greenland Ice Sheet is common up to ∼1400 m elevation and, in extreme melt years, even higher. Water produced on the ice sheet surface collects in lakes and drains over the ice sheet surface via supraglacial streams and through the ice sheet via moulins. Water delivered to the base of the ice sheet can cause uplift and enhanced sliding locally. Here we use ice‐penetrating radar data to observe the effects of significant basal melting coincident with moulins and calculate how much basal melt occurred. We find that more melting has occurred than can be explained by the release of potential energy from the drainage of surface meltwater during one melt season suggesting that these moulins are persistent for multiple years. We find only a few persistent moulins in our study area that drain the equivalent of multiple lakes per year and likely remain active over several years. Our observations indicate that once established, these persistent moulins might be capable of establishing well‐connected meltwater drainage pathways.
MESSENGER observations of large flux transfer events at Mercury
Authors: Slavin James A. , Lepping Ronald P. , Wu Chin‐Chun , Anderson Brian J. , Baker Daniel N. , Benna Mehdi , Boardsen Scott A. , Killen Rosemary M. , Korth Haje , Krimigis Stamatios M. , McClintock William E. , McNutt Ralph L. , Sarantos Menelaos , Schriver David , Solomon Sean C. , Trávníček Pavel , Zurbuchen Thomas H.
Published: January 2010

Six flux transfer events (FTEs) were encountered during MESSENGER's first two flybys of Mercury (M1 and M2). For M1 the interplanetary magnetic field (IMF) was predominantly northward and four FTEs with durations of 1 to 6 s were observed in the magnetosheath following southward IMF turnings. The IMF was steadily southward during M2, and an FTE 4 s in duration was observed just inside the dawn magnetopause followed ∼32 s later by a 7‐s FTE in the magnetosheath. Flux rope models were fit to the magnetic field data to determine FTE dimensions and flux content. The largest FTE observed by MESSENGER had a diameter of ∼1 RM (where RM is Mercury's radius), and its open magnetic field increased the fraction of the surface exposed to the solar wind by 10–20 percent and contributed up to ∼30 kV to the cross‐magnetospheric electric potential.
Interventions to Prevent Obesity in 0–5 Year Olds: An Updated Systematic Review of the Literature
Authors: Hesketh Kylie D. , Campbell Karen J.
Published: January 2010

The small number and recency of the early childhood obesity‐prevention literature identified in a previous review of interventions to prevent obesity, promote healthy eating, physical activity, and/or reduce sedentary behaviors in 0–5 year olds suggests this is a new and developing research area. The current review was conducted to provide an update of the rapidly emerging evidence in this area and to assess the quality of studies reported. Ten electronic databases were searched to identify literature published from January 1995 to August 2008. Inclusion criteria: interventions reporting child anthropometric, diet, physical activity, or sedentary behavior outcomes and focusing on children aged 0–5 years of age. Exclusion criteria: focusing on breastfeeding, eating disorders, obesity treatment, malnutrition, or school‐based interventions. Two reviewers independently extracted data and assessed study quality. Twenty‐three studies met all criteria. Most were conducted in preschool/childcare (n = 9) or home settings (n = 8). Approximately half targeted socioeconomically disadvantaged children (n = 12) and three quarters were published from 2003 onward (n = 17). The interventions varied widely although most were multifaceted in their approach. While study design and quality varied most studies reported their interventions were feasible and acceptable, although impact on behaviors that contribute to obesity were not achieved by all. Early childhood obesity‐prevention interventions represent a rapidly growing research area. Current evidence suggests that behaviors that contribute to obesity can be positively impacted in a range of settings and provides important insights into the most effective strategies for promoting healthy weight from early childhood.
Reductions in Child Obesity Among Disadvantaged School Children With Community Involvement: The Travis County CATCH Trial
Authors: Hoelscher Deanna M. , Springer Andrew E. , Ranjit Nalini , Perry Cheryl L. , Evans Alexandra E. , Stigler Melissa , Kelder Steven H.
Published: January 2010

The objective of this study was to compare the impact of two intervention approaches on the prevalence of child overweight and obesity: (i) Coordinated Approach To Child Health BasicPlus (CATCH BP), in which schools were provided evidence‐based coordinated school health program training, materials, and facilitator support visits, and (ii) CATCH BP and Community (BPC), in which BP schools received additional promotion of community partnerships with the aim of integrating community members and organizations into schools, local decision making and action, and best practices workshops. Schools (n = 97) in four central Texas districts were recruited to participate in the 4‐year project. Of the low‐income schools (n = 58), 15 schools were selected to receive the BPC intervention and matched with 15 schools in the BP condition. A serial cross‐sectional design was used, in which 4th grade student BMI, physical activity, and diet were assessed in the 30 schools in spring 2007 and 2008. Measurements in spring 2007 included 1,107 students, with 53% female; 61% Hispanic, and 14% African American; and mean age of 9.9 years. Adjusted prevalence of overweight/obesity (≥85th percentile) was 42.0 and 47.4% in spring 2007 for the BP and BPC students, respectively. From spring 2007 to spring 2008, the percent of students classified as overweight/obese decreased by 1.3 percentage points (P = 0.33) in BP schools, compared to a decrease of 8.3 percentage points (P < 0.005) in students from BPC schools; the difference between conditions was significant (P = 0.05). CATCH BPC students also reported more positive trends in related behaviors. Implementation of a community‐enhanced school program can be effective in reducing the prevalence of child overweight in low‐income student populations.
Randomized Controlled Trial of the MEND Program: A Family‐based Community Intervention for Childhood Obesity
Authors: Sacher Paul M. , Kolotourou Maria , Chadwick Paul M. , Cole Tim J. , Lawson Margaret S. , Lucas Alan , Singhal Atul
Published: January 2010

The aim of this study was to evaluate the effectiveness of the Mind, Exercise, Nutrition, Do it (MEND) Program, a multicomponent community‐based childhood obesity intervention (www.mendcentral.org). One hundred and sixteen obese children (BMI ≥ 98th percentile, UK 1990 reference data) were randomly assigned to intervention or waiting list control (6‐month delayed intervention). Parents and children attended eighteen 2‐h group educational and physical activity sessions held twice weekly in sports centers and schools, followed by a 12‐week free family swimming pass. Waist circumference, BMI, body composition, physical activity level, sedentary activities, cardiovascular fitness, and self‐esteem were assessed at baseline and at 6 months. Children were followed up 12 months from baseline (0 and 6 months postintervention for the control and intervention group, respectively). Participants in the intervention group had a reduced waist circumference z‐score (−0.37; P < 0.0001) and BMI z‐score (−0.24; P < 0.0001) at 6 months when compared to the controls. Significant between‐group differences were also observed in cardiovascular fitness, physical activity, sedentary behaviors, and self‐esteem. Mean attendance for the MEND Program was 86%. At 12 months, children in the intervention group had reduced their waist and BMI z‐scores by 0.47 (P < 0.0001) and 0.23 (P < 0.0001), respectively, and benefits in cardiovascular fitness, physical activity levels, and self‐esteem were sustained. High‐attendance rates suggest that families found this intensive community‐based intervention acceptable. Further larger controlled trials are currently underway to confirm the promising findings of this initial trial.
The Use of Mentoring Programs to Improve Energy Balance Behaviors in High‐risk Children
Authors: Haire‐Joshu Debra , Nanney Marilyn S. , Elliott Michael , Davey Cynthia , Caito Nicole , Loman Deborah , Brownson Ross C. , Kreuter Matthew W.
Published: January 2010

This study tested the impact of a multicomponent intervention entitled “Partners of all Ages Reading About Diet and Exercise” (PARADE) a child‐focused energy balance intervention incorporated into mentoring programs. We used a group randomized nested cohort design randomizing mentoring program sites (n = 119) and children (N = 782; females = 49%; African American = 37%; mean (s.d.) age = 8.5 (1.5) years) to intervention or usual care conditions. PARADE mentors delivered eight lesson plans addressing key concepts related to diet and activity; eight child‐focused computer‐tailored storybooks with messages targeting that child's diet and activity patterns and eight parent action support newsletters. When compared to the control group, PARADE children were more knowledgeable of diet and activity guidelines (P < 0.01), challenged themselves more to eat five fruits and vegetables (FV) (P < 0.01) and be active 1 h daily (P < 0.01), and to ask for FV for snack (P = 0.015). Calories from high fat foods decreased in overweight/obese children, but not for normal weight children (P = 0.059). There were no significant differences in fruit and vegetable intake, total calories, percent time being active, or BMI z‐score. The combination of one‐to‐one mentoring, child‐focused computer based tailoring, and parent support may impact important behavioral change precursors in environments over which the child has control, especially among normal weight children. Further, work is needed to evaluate the impact of family‐focused multicomponent interventions, including computer‐tailored approaches, directed toward both the parent and the child.
The Use of Biosimulation in the Design of a Novel Multilevel Weight Loss Maintenance Program for Overweight Children
Authors: Wilfley Denise E. , Van Buren Dorothy J. , Theim Kelly R. , Stein Richard I. , Saelens Brian E. , Ezzet Farkad , Russian Angela C. , Perri Michael G. , Epstein Leonard H.
Published: January 2010

Weight loss outcomes achieved through conventional behavior change interventions are prone to deterioration over time. Basic learning laboratory studies in the area of behavioral extinction and renewal and multilevel models of weight control offer clues as to why newly acquired weight loss skills are prone to relapse. According to these models, current clinic‐based interventions may not be of sufficient duration or scope to allow for the practice of new skills across the multiple community contexts necessary to promote sustainable weight loss. Although longer, more intensive interventions with greater reach may hold the key to improving weight loss outcomes, it is difficult to test these assumptions in a time efficient and cost‐effective manner. A research design tool that has been increasingly utilized in other fields (e.g., pharmaceuticals) is the use of biosimulation analyses. The present study describes our research team's use of computer simulation models to assist in designing a study to test a novel, comprehensive socio‐environmental treatment approach to weight loss maintenance in children ages 7–12 years. Weight outcome data from the weight loss, weight maintenance, and follow‐up phases of a recently completed randomized controlled trial (RCT) were used to describe the time course of a proposed, extended multilevel treatment program. Simulations were then conducted to project the expected changes in child percent overweight (POW) trajectories in the proposed study. A 12.9% decrease in POW at 30 months was estimated based upon the midway point between models of “best‐case” and “worst‐case” weight maintenance scenarios. Preliminary data and further analyses, including biosimulation projections, suggest that our socio‐environmental approach to weight loss maintenance treatment is promising and warrants evaluation in a large‐scale RCT. Biosimulation techniques may have utility in the design of future community‐level interventions for the treatment and prevention of childhood overweight.
The Fun Families Study: Intervention to Reduce Children's TV Viewing
Authors: Escobar‐Chaves Soledad Liliana , Markham Christine M. , Addy Robert C. , Greisinger Anthony , Murray Nancy G. , Brehm Brenda
Published: January 2010

Media consumption may contribute to childhood obesity. This study developed and evaluated a theory‐based, parent‐focused intervention to reduce television and other media consumption to prevent and reduce childhood obesity. Families (n = 202) with children ages 6–9 were recruited from a large, urban multiethnic population into a randomized controlled trial (101 families into the intervention group and 101 into the control group), and were followed for 6 months. The intervention consisted of a 2‐hour workshop and six bimonthly newsletters. Behavioral objectives included: (i) reduce TV watching; (ii) turn off TV when nobody is watching; (iii) no TV with meals; (iv) no TV in the child's bedroom; and (v) engage in fun non‐media related activities. Parents were 89% female, 44% white, 28% African American, 17% Latino, and 11% Asian, mean age 40 years (s.d. = 7.5); 72% were married. Children were 49% female, mean age 8 years (s.d. = 0.95). Sixty‐five percent of households had three or more TVs and video game players; 37% had at least one handheld video game, and 53% had three or more computers. Average children's weekday media exposure was 6.1 hours. At 6 months follow‐up, the intervention group was less likely to report the TV being on when nobody was watching (adjusted odds ratio (AOR) = 0.23, P < 0.05), less likely to report eating snacks while watching TV (AOR = 0.47, P < 0.05), and less likely to have a TV in the child's bedroom (AOR = 0.23, P < 0.01). There was a trend toward reducing actual media consumption but these outcomes did not reach statistical significance. Effective strategies to reduce children's TV viewing were identified.
An Experimental Study of the Role of Weight Bias in Candidate Evaluation
Authors: Miller Beth J. , Lundgren Jennifer D.
Published: January 2010

Obese individuals are evaluated negatively and attributed negative trait characteristics in several contexts including employment, health care, and education. The current experimental study of college students examined the effect of body mass on the evaluation of political candidates and examined whether the gender of the candidate moderated the relationship. A series of ordinary least squares regression analyses found an interactive effect between candidate obesity and candidate gender for global evaluation and for several trait characteristics. Specifically, obese female candidates were evaluated more negatively than nonobese female candidates and nonobese male candidates were evaluated more negatively than were obese male candidates. This interaction persisted even after controlling for standard political and demographic characteristics of the evaluator. These findings suggest that weight bias exists for obese female political candidates, but that larger body size may be an asset for male candidates. The ability of candidates to be successful may depend less on their policy positions or even party affiliation and more on their physical attributes than has been previously assumed.
Metabolic Adaptation Follows Contractile Dysfunction in the Heart of Obese Zucker Rats Fed a High‐Fat “Western” Diet
Authors: Burgmaier Mathias , Sen Shiraj , Philip Femi , Wilson Christopher R. , Miller Charles C. , Young Martin E. , Taegtmeyer Heinrich
Published: January 2010

The normal heart responds to changes in its metabolic milieu by changing relative oxidation rates of energy‐providing substrates. We hypothesized that this flexibility is lost when genetically obese rats are fed a high‐caloric, high‐fat “Western” diet (WD). Male Zucker obese (ZO) and Zucker lean (ZL) rats were fed either control or WD composed of 10 kcal% and 45 kcal% fat, respectively, for 7 or 28 days. Cardiac triglycerides and mRNA transcript levels were measured in situ. Substrate oxidation rates and cardiac power were measured ex vivo. Hearts from ZO rats fed WD for 7 days showed decreased cardiac power and increased cardiac triglyceride content, but no change in oleate oxidation rates or mRNA transcript levels of pyruvate dehydrogenase kinase‐4 (PDK‐4), uncoupling protein‐3 (UCP‐3), and mitochondrial (MTE‐1) and cytosolic thioesterase‐1(CTE‐1). When fed WD for 28 days, ZO rats showed no further decrease in cardiac power and no further increase in intramyocardial triglyceride levels compared to ZO rats fed the same diet for 7 days only, but did show significantly increased oleate oxidation rates and transcript levels of CTE‐1, MTE‐1, PDK‐4, and UCP‐3. In contrast, hearts from ZL rats fed WD showed increased rates of oleate oxidation and increased transcript levels of the fatty acid responsive genes investigated, and no further deterioration of contractile function. We conclude that exposing a genetic model of obesity to the nutrient stress of WD results in an early reversible loss of metabolic flexibility of the heart that is accompanied by contractile dysfunction.
Increased Levels of Plasma Acylcarnitines in Obesity and Type 2 Diabetes and Identification of a Marker of Glucolipotoxicity
Authors: Mihalik Stephanie J. , Goodpaster Bret H. , Kelley David E. , Chace Donald H. , Vockley Jerry , Toledo Frederico G.S. , DeLany James P.
Published: January 2010

Dysregulation of fatty acid oxidation (FAO) is recognized as important in the pathophysiology of obesity and insulin resistance (IR). However, demonstrating FAO defects in vivo in humans has entailed complex and invasive methodologies. Recently, the identification of genetic blocks in FAO has been vastly simplified by using tandem mass spectrometry (MS/MS) of dried bloodspots to specify acylcarnitine (AcylCN) alterations characteristic for each disorder. This technology has recently been applied to examine FAO alterations in human and animal models of obesity and type 2 diabetes mellitus (T2DM). This study focused on characterizing AcylCN profiles in human plasma from individuals with obesity and T2DM during fasting and insulin‐stimulated conditions. Following an overnight fast, plasma was obtained from lean (n = 12), obese nondiabetic (n = 14), and T2DM (n = 10) participants and analyzed for AcylCN using MS/MS. Plasma samples were also obtained at the end of a 4‐h insulin‐stimulated euglycemic clamp. In obesity and T2DM, long‐chain AcylCNs were similarly significantly increased in the fasted state; free‐CN levels were also elevated. Additionally, T2DM subjects of comparable BMI had increased short‐ and medium‐chain AcylCNs, both saturated and hydroxy, as well as increased C4‐dicarboxylcarnitine (C4DC–CN) that correlated with an index of poor glycemic control (HbA1c; r = 0.74; P < 0.0001). Insulin infusion reduced all species of plasma AcylCN but this reduction was blunted in T2DM. Plasma long‐chain AcylCN species are increased in obesity and T2DM, suggesting that more fatty acids can enter mitochondria. In T2DM, many shorter species accumulate, suggesting that they have a generalized complex oxidation defect.
Sitting Time Is Associated With Weight, but Not With Weight Gain in Mid‐Aged Australian Women
Authors: van Uffelen Jannique G.Z. , Watson Melanie J. , Dobson Annette J. , Brown Wendy J.
Published: January 2010

The aim of this study was to examine the associations between sitting time, weight, and weight gain in Australian women born in 1946–1951. Data were from 8,233 women who completed surveys for the Australian Longitudinal Study on Women's Health (ALSWH) in 2001, 2004, and 2007. Associations between sitting time and weight, and between sitting time and weight change in each 3‐year period were examined using repeated measures modeling. The associations between weight and change in sitting time were also examined. Analyses were stratified for BMI categories: normal weight (18.5 ≤ BMI < 25), overweight (25 ≤ BMI < 30), and obese (BMI ≥ 30). In cross‐sectional models, each additional hour of sitting time was associated with 110 g (95% confidence interval (CI): 40–180) and 260 g (95% CI: 140–380) additional weight in overweight and obese women, respectively (fully adjusted model). In prospective analyses, sitting time was not consistently associated with weight change, after adjustment for other variables, and weight was not associated with change in sitting time over successive 3‐year periods. In conclusion, although the cross‐sectional associations between sitting time and weight were evident in overweight and obese women, there was no consistent association between sitting time and weight gain. A potential explanation is that prospective associations may only be apparent over longer periods of time. These results do not support a role for reducing sitting time as a short‐term means of weight control in mid‐aged women.
T‐Cell Recruitment and Th1 Polarization in Adipose Tissue During Diet‐Induced Obesity in C57BL/6 Mice
Authors: Strissel Katherine J. , DeFuria Jason , Shaul Merav E. , Bennett Grace , Greenberg Andrew S. , Obin Martin S.
Published: January 2010

The role of adaptive immunity in obesity‐associated adipose tissue (AT) inflammation and insulin resistance (IR) is controversial. We employed flow cytometry and quantitative PCR to assess T‐cell recruitment and activation in epididymal AT (eAT) of C57BL/6 mice during 4–22 weeks of a high‐fat diet (HFD (60% energy)). By week 6, eAT mass and stromal vascular cell (SVC) number increased threefold in mice fed HFD, coincident with onset of IR. We observed no increase in the proportion of CD3+ SVCs or in gene expression of CD3, interferon‐γ (IFN‐γ), or regulated upon activation, normal T‐cell expressed and secreted (RANTES) during the first 16 weeks of HFD. In contrast, CD11c+ macrophages (MΦ) were enriched sixfold by week 8 (P < 0.01). SVC enrichment for T cells (predominantly CD4+ and CD8+) and elevated IFN‐γ and RANTES gene expression were detected by 20–22 weeks of HFD (P < 0.01), coincident with the resolution of eAT remodeling. HFD‐induced T‐cell priming earlier in the obesity time course is suggested by (i) elevated (fivefold) interleukin‐12 (IL‐12)p40 gene expression in eAT by week 12 (P ≤ 0.01) and (ii) greater IFN‐γ secretion from phorbol myristate acetate (PMA)/ionophore‐stimulated eAT explants at week 6 (onefold, P = 0.08) and week 12 (fivefold, P < 0.001). In conclusion, T‐cell enrichment and IFN‐γ gene induction occur subsequent to AT macrophage (ATMΦ) recruitment, onset of IR and resolution of eAT remodeling. However, enhanced priming for IFN‐γ production suggests the contribution of CD4+ and/or CD8+ effectors to cell‐mediated immune responses promoting HFD‐induced AT inflammation and IR.
Comparison of DXA and CT in the Assessment of Body Composition in Premenopausal Women With Obesity and Anorexia Nervosa
Authors: Bredella Miriam A. , Ghomi Reza Hosseini , Thomas Bijoy J. , Torriani Martin , Brick Danielle J. , Gerweck Anu V. , Misra Madhusmita , Klibanski Anne , Miller Karen K.
Published: January 2010

Accurate methods for assessing body composition in subjects with obesity and anorexia nervosa (AN) are important for determination of metabolic and cardiovascular risk factors and to monitor therapeutic interventions. The purpose of our study was to assess the accuracy of dual‐energy X‐ray absorptiometry (DXA) for measuring abdominal and thigh fat, and thigh muscle mass in premenopausal women with obesity, AN, and normal weight compared to computed tomography (CT). In addition, we wanted to assess the impact of hydration on DXA‐derived measures of body composition by using bioelectrical impedance analysis (BIA). We studied a total of 91 premenopausal women (34 obese, 39 with AN, and 18 lean controls). Our results demonstrate strong correlations between DXA‐ and CT‐derived body composition measurements in AN, obese, and lean controls (r = 0.77–0.95, P < 0.0001). After controlling for total body water (TBW), the correlation coefficients were comparable. DXA trunk fat correlated with CT visceral fat (r = 0.51–0.70, P < 0.0001). DXA underestimated trunk and thigh fat and overestimated thigh muscle mass and this error increased with increasing weight. Our study showed that DXA is a useful method for assessing body composition in premenopausal women within the phenotypic spectrum ranging from obesity to AN. However, it is important to recognize that DXA may not accurately assess body composition in markedly obese women. The level of hydration does not significantly affect most DXA body composition measurements, with the exceptions of thigh fat.
How controlled and versatile is N-carboxy anhydride (NCA) polymerization at 0 °C? Effect of temperature on homo-, block- and graft (co)polymerization
Authors: Habraken Gijs J. M. , Peeters Maloes , Dietz Carin H. J. T. , Koning Cor E. , Heise Andreas
Published: January 2010

The polymerization of N-carboxyanhydride (NCA) at low temperatures is controlled and allows the synthesis of a variety of well-defined polypetides.
Fluorescence of the perylene radical cation and an inaccessible D/D1 conical intersection: An MMVB, RASSCF, and TD-DFT computational study
Authors: Tokmachev Andrei M. , Boggio-Pasqua Martial , Mendive-Tapia David , Bearpark Michael J. , Robb Michael A.
Published: January 2010

The photophysics of the perylene radical cation (Pe•+) was studied using the molecular mechanics-valence bond (MMVB) hybrid force field. Potential energy surfaces of the first three electronic states were investigated. Geometry optimizations of critical points—including conical intersections between the relevant electronic states—were performed using the MMVB analytical energy gradient for cations. No accessible planar conical intersection between the D0 and D1 states of Pe•+ was found; this is consistent with the experimentally observed D1 lifetimes and the observation of D1 emission from this cation in the condensed phase. Benchmark RASSCF and TD-DFT calculations support the reliability of the MMVB results.
Application-oriented nitride substrates: The key to long-wavelength nitride lasers beyond 500 nm
Authors: Sharma T. K. , Towe E.
Published: January 2010

We present results based on quantum mechanical estimates of the longest emission wavelength for nitride laser diodes grown on c-plane GaN/sapphire substrates. The results indicate that the absence of polarization-induced electric fields in nonpolar/semipolar GaN substrates does not necessarily guarantee that nitride lasers will operate at the longest possible wavelength for a given set of parameters. Our calculations suggest that the limit on the longest possible wavelength of nitride lasers is constrained by the lattice mismatch rather than by the strength of the polarization-induced electric field. Although it may be possible to develop lasers that approach the green portion of the electromagnetic spectrum (∼520 nm) by growing the structures on nonpolar/semipolar GaN substrates, the development of red and near-infrared nitride lasers appears extremely difficult by merely growing the structures on any crystallographic orientation of the GaN substrate. We suggest that efficient lasers emitting at the green, red, and near-infrared wavelengths can be developed by growing the laser structures on a proposed application-oriented nitride substrate (AONS) that is lattice-matched to the epilayers grown on it. The AONSs are bulk InxGa1−xN ternary substrates with Indium compositions chosen to lattice-match the epilayers to be grown on them. The concept of the AONS can be extended deep into the infrared region by increasing the Indium mole fraction of the quantum well layers in the active region of the laser and by choosing the AONS that best matches the specific wavelength desired. We believe it would be possible, by using this concept, to make nitride lasers at the fiber-optic communication windows at 1.3 and 1.55 μm, thus eliminating the need to use the hazardous arsenides/phosphides materials currently used to make the communications lasers.
Influence of the salinity on the characteristics of acoustic signal in salt water generated by pulsed CO2 laser
Authors: Zhu Haihong , Chen Qingming , Cheng Zuhai , Tang Huiqun
Published: January 2010

The experimental study on the laser acoustic signal in salt water with different salinities using high power pulsed CO2 laser has been carried out. By using a hydrophone to receive the sound signal and further analyzing in time domain, the effects of the salinity and pulse energy on the characteristics of the sound signals were disclosed. The results show that the salinity has significant effect on the characteristics of the laser acoustic signal. As the salinity increases, the amplitude of the sound signal decreases. The profile of the sound signal also changes with the salinity. As the salinity decreases, the changes in the signal waveform show the loss of its originally bimodal shape. This phenomenon is also found in the laser energy which decreases when the salinity is kept constant.
Optical properties of AlxGa1−xN alloy
Authors: Takeuchi Katsuki , Adachi Sadao , Ohtsuka Kohji
Published: January 2010

The optical response of the AlxGa1−xN alloy has been analyzed using a simplified model of interband transitions (E≤10 eV). The present model reveals distinct structures at energies of the E0, E1, F1, and E0′ critical points. The Cauchy−Lorentz expression popularly used for the modeling of the three-dimensional M0 and saddle-point excitonic transitions does not satisfy the Kramers−Krönig requirements but does so if its form is properly modified. As a result, excellent agreement is achieved between the experimental and calculated ε(E) spectra over the entire range of photon energies. Dielectric-related optical constants, such as the complex refractive index, absorption coefficient, and normal-incidence reflectivity, of the AlxGa1−xN alloy are also presented. The high-frequency and static dielectric constants of the AlxGa1−xN alloy are determined to be ε∞(x)=5.27−1.07x and εs(x)=9.28−1.45x, respectively.
A transferable coarse-grained potential to study the structure of confined, supercritical Lennard-Jones fluids
Authors: Sanghi T. , Aluru N. R.
Published: January 2010

In this paper, we develop a transferable coarse-grained interatomic potential to study the structure of simple (spherical and nonpolar) Lennard-Jones (LJ) fluids confined at supercritical temperatures. The potential is used in empirical potential based quasicontinuum theory, [A. V. Raghunathan et al., J. Chem. Phys. 127, 174701 (2007)] to study the structure of three simple LJ fluids (oxygen, methane, and argon) confined in slitlike geometries. The results obtained using the coarse-grained interatomic potential are found to be in good agreement with those predicted by equilibrium molecular dynamics simulations.
Magnetotransport behavior of Co nanowires coupled to Ni80Fe20 films
Authors: Goolaup S. , Adeyeye A. O. , Singh N.
Published: January 2010

We have fabricated and characterized hybrid-trilayer ferromagnetic structures comprising of 60-nm-thick Ni80Fe20 (Py) film grown on top of patterned array of 60-nm-thick Co nanowires (NWs) with Cu spacer layer. The hybrid structures display unique magnetic and transport properties due to the nonuniform magnetization distribution from the Py layer inducing local stray fields, which could be coupled to the underlying Co NWs. The temperature dependence of the magnetoresistance behavior is dominated by the interplay between the anisotropic magnetoresistance and the giant magnetoresistance effects.
Optical doping and damage formation in AlN by Eu implantation
Authors: Lorenz K. , Alves E. , Gloux F. , Ruterana P. , Peres M. , Neves A. J. , Monteiro T.
Published: January 2010

AlN films grown on sapphire were implanted with 300 keV Eu ions to fluences from 3×1014 to 1.4×1017 atoms/cm2 in two different geometries: “channeled” along the c-axis and “random” with a 10° angle between the ion beam and the surface normal. A detailed study of implantation damage accumulation is presented. Strong ion channeling effects are observed leading to significantly decreased damage levels for the channeled implantation within the entire fluence range. For random implantation, a buried amorphous layer is formed at the highest fluences. Red Eu-related photoluminescence at room temperature is observed in all samples with highest intensities for low damage samples (low fluence and channeled implantation) after annealing. Implantation damage, once formed, is shown to be stable up to very high temperatures.
Energy-band alignment of Al2O3 and HfAlO gate dielectrics deposited by atomic layer deposition on 4H–SiC
Authors: Suri Rahul , Kirkpatrick Casey J. , Lichtenwalner Daniel J. , Misra Veena
Published: January 2010

Energy band alignment and band gap of Al2O3 and HfAlO films grown by atomic layer deposition on 4H–SiC were determined using x-ray photoelectron spectroscopy. Al2O3 exhibited a symmetric band profile with a conduction band offset (ΔEC) of 1.88 eV and a valence band offset (ΔEV) of 1.87 eV. HfAlO yielded a smaller ΔEC of 1.16 eV and ΔEV of 1.59 eV. The higher dielectric constant and higher effective breakdown field of HfAlO compared to Al2O3, coupled with sufficient electron and hole barrier heights, makes it a potential dielectric for use on 4H–SiC, and provokes interest in further investigation of HfAlO/4H–SiC properties.
The influence of coiled nanostructure on the enhancement of dielectric constants and electromagnetic shielding efficiency in polymer composites
Authors: Park Sung Hoon , Theilmann Paul , Yang Keqin , Rao Apparao M. , Bandaru Prabhakar R.
Published: January 2010

We report through a comparison of the electromagnetic properties of polymer composites constituted of linear and nonlinear (helically coiled) carbon nanotubes (CNTs) that the electromagnetic interference (EMI) shielding efficiency could be much increased in the latter. A higher ac conductivity and relative dielectric permittivity (both ε′ and ε″) was recorded when coiled structures were used, and was ascribed to enhanced capacitive and electric field depolarization effects. The EMI shielding was related to the extended length/diameter aspect ratio of the CNTs. Our study has implications in the design of materials for EMI shielding, where nanostructure geometry could play a major role.
Enhancement of femtosecond laser-induced nucleation of protein in a gel solution
Authors: Murai Ryota , Yoshikawa Hiroshi Y. , Takahashi Yoshinori , Maruyama Mihoko , Sugiyama Shigeru , Sazaki Gen , Adachi Hiroaki , Takano Kazufumi , Matsumura Hiroyoshi , Murakami Satoshi , Inoue Tsuyoshi , Mori Yusuke
Published: January 2010

We found that the use of a gel solution with agarose enhanced femtosecond laser-induced nucleation and produced hen egg white lysozyme crystals at three to five times lower supersaturation than those by the femtosecond laser or agarose alone. The fast fluorescence imaging of the protein in the gel solution revealed that cavitation bubbles created high-concentration regions at the focal point, which could be the trigger for protein nucleation. The lower diffusions of protein molecules in agarose gel retained the high-concentration regions for a longer time, and facilitated the nucleation.
The weak covalent bond in NgAuF (Ng=Ar, Kr, Xe): A challenge for subsystem density functional theory
Authors: Beyhan S. Maya , Götz Andreas W. , Jacob Christoph R. , Visscher Lucas
Published: January 2010

We have assessed the accuracy of a representative set of currently available approximate kinetic-energy functionals used within the frozen-density embedding scheme for the NgAuF (Ng=Ar, Kr, Xe) molecules, which we partitioned into a Ng and a AuF subsystem. Although it is weak, there is a covalent interaction between these subsystems which represents a challenge for this subsystem density functional theory approach. We analyzed the effective-embedding potentials and resulting electron density distributions and provide a quantitative analysis of the latter from dipole moment differences and root-mean-square errors in the density with respect to the supermolecular Kohn–Sham density functional theory reference calculation. Our results lead to the conclusion that none of the tested approximate kinetic-energy functionals performs well enough to describe the bond between the noble gas and gold adequately. This observation contributes to the growing evidence that the current procedure to obtain approximate kinetic-energy functionals by reparametrizing functionals obtained via the “conjointness” hypothesis of Lee, Lee, and Parr [Phys. Rev. A 44, 768 (1991)] is insufficient to treat metal-ligand interactions with covalent character.