bluuebunny/crossref_metadata_2025 huggingface dataset:
Use of eigendecomposition in a parameter sensitivity analysis of the Community Land Model
Authors: Göhler M. , Mai J. , Cuntz M.
Published: May 2013

This study explores the use of eigendecomposition in a sensitivity analysis of the Community Land Model CLM, revision 3.5, with respect to its parametrization. Latent heat, sensible heat, and photosynthesis are used as target variables. The eigendecomposition of a sensitivity matrix, containing numerically derived sensitivity measures, can be used to study parameter significance. Existing parameter ranking and selection methods are examined. Furthermore, a new parameter significance ranking index is proposed which is working in concert with a new proposed selection criterion. This methodology explicitly takes parameter covariations into account. The results are consistent and similar to the most elaborate method tested in this study, but the new method has fewer assumptions. The number of significant parameters depends on the degree of variation that a single parameter is allowed to generate in the cost function. The method declares two thirds out of 66 parameters to be significant model parameters for an allowed change of 1% and only 10 parameters for an allowed change of 10% of the cost function. The sensible heat flux is shown to be the least sensitive model output in comparison with latent heat or photosynthesis. Parameters that determine maximum carboxylation and the slope of stomatal conductance are very sensitive for photosynthesis, whereas soil water parameters are significant for latent heat and C4photosynthesis. It is concluded that the proposed procedure is parsimonious, can analyze sensitivities of more than one model output simultaneously, and helps to identify significant parameters while taking parameter interactions into account.
Isogeometric finite element analysis of poroelasticity
Authors: Irzal Faisal , Remmers Joris J. C. , Verhoosel Clemens V. , de Borst René
Published: May 2013

We present an alternative numerical approach for predicting the behaviour of a deformable fluid‐saturated porous medium. The conventional finite element technology is replaced by isogeometric analysis that uses non‐uniform rational B‐splines. The ability of these functions to provide higher‐order continuity and to exactly represent complex geometries makes isogeometric analysis a suitable candidate for accurately modeling a poroelastic medium. After some preliminaries regarding the formulation of isogeometric finite elements using Bézier extraction and a concise outline of poroelasticity theory, we describe how isogeometric finite elements can be used for a mixed formulation that results in case of a porous medium. The manuscript concludes by one‐dimensional and two‐dimensional examples, which demonstrate the superiority of the results of isogeometric finite element analysis in terms of the smoothness of the results compared with conventional finite element analysis and suggest that the requirement on the minimum time step for consolidation problems can be mitigated using interpolation functions that possess a higher‐order continuity. Copyright © 2013 John Wiley & Sons, Ltd.
Weak Galerkin finite element methods for Parabolic equations
Authors: Li Qiaoluan H. , Wang Junping
Published: May 2013

A newly developed weak Galerkin method is proposed to solve parabolic equations. This method allows the usage of totally discontinuous functions in approximation space and preserves the energy conservation law. Both continuous and discontinuous time weak Galerkin finite element schemes are developed and analyzed. Optimal‐order error estimates in both H1 and L2 norms are established. Numerical tests are performed and reported. © 2013 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2013
Convergence analysis of an hp finite element method for singularly perturbed transmission problems in smooth domains
Authors: Nicaise Serge , Xenophontos Christos
Published: May 2013

We consider a two‐dimensional singularly perturbed transmission problem with two different diffusion coefficients, in a domain with smooth (analytic) boundary. The solution will contain boundary layers only in the part of the domain where the diffusion coefficient is high and interface layers along the interface. Utilizing existing and newly derived regularity results for the exact solution, we prove the robustness of an hp finite element method for its approximation. Under the assumption of analytic input data, we show that the method converges at an “exponential” rate, provided the mesh and polynomial degree distribution are chosen appropriately. Numerical results illustrating our theoretical findings are also included. © 2013 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2013
Mortar spectral element discretization of the stokes problem in axisymmetric domains
Authors: Aouadi Saloua Mani , Bernardi Christine , Satouri Jamil
Published: May 2013

The Stokes problem in a tri‐dimensional axisymmetric domain results into a countable family of two‐dimensional problems when using the Fourier coefficients with respect to the angular variable. Relying on this dimension reduction, we propose and study a mortar spectral element discretization of the problem. Numerical experiments confirm the efficiency of this method. © 2013 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 30: 44–73, 2014
Redefining metabolic syndrome as a fat storage condition based on studies of comparative physiology
Authors: Johnson Richard J. , Stenvinkel Peter , Martin Sandra L. , Jani Alkesh , Sánchez‐Lozada Laura Gabriela , Hill James O. , Lanaspa Miguel A.
Published: May 2013

Objective: The metabolic syndrome refers to a constellation of signs including abdominal obesity, elevated serum triglycerides, low HDL‐cholesterol, elevated blood pressure, and insulin resistance. Today approximately one third of the adult population has the metabolic syndrome. While there is little doubt that the signs constituting the metabolic syndrome frequently cluster, much controversy exists over the definition, pathogenesis, or clinical utility.

Design and Methods: Here we present evidence from the field of comparative physiology that the metabolic syndrome is similar to the biological process that animals engage to store fat in preparation for periods of food shortage.

Results: We propose that the metabolic syndrome be changed to fat storage condition to more clearly align with its etiology. Obesity in humans is likely the consequences of both genetic predisposition (driven in part by thrifty genes) and environment. Recent studies suggest that the loss of the uricase gene may be one factor that predisposes humans to obesity today.

Conclusion: Understanding the process animals engage to switch from a lean insulin‐sensitive to an obese insulin‐resistant state may provide novel insights into the cause of obesity and diabetes in humans, and unique opportunities for reversing their pathology.
Combining behavioral weight loss treatment and a commercial program: A randomized clinical trial
Authors: Pinto Angela Marinilli , Fava Joseph L. , Hoffmann Debra A. , Wing Rena R.
Published: May 2013

Objective:

To test the hypothesis that a novel weight loss approach that combined the fundamental components of professionally delivered behavioral weight loss (BWL) treatment with the existing Weight Watchers (WW) program would produce better weight losses than WW alone no differences were expected between the novel treatment and BWL alone.

Design and Methods:

Participants were 141 overweight and obese adults (90% women, 67% non‐White, mean age = 49.7 ± 9.2 years, mean body mass index = 36.2 ± 5.5 kg/m2) randomly assigned to 48 weeks of BWL, 48 weeks of WW, or 12 weeks of BWL followed by 36 weeks of WW [combined treatment (CT)]. Assessments were conducted at baseline and weeks 12, 24, and 48, with weight change as the primary outcome.

Results:

Linear mixed model analysis showed that 24‐week weight losses did not differ significantly between treatment groups; however, weight losses at 48 weeks were greater in the WW group (M = −6.0 kg, standard error (SE) = 0.8) compared with the CT group (M = −3.6 kg, SE = 0.8; P = 0.032), with BWL not significantly different from either (M = −5.4 kg, SE = 0.8). Further, a greater proportion of WW participants lost 10% of baseline weight by 48 weeks compared with BWL or CT (36.7%, 13.0%, and 15.2%, respectively, P < 0.05).

Conclusion:

This study shows that the WW program can produce clinically meaningful weight losses and provides no evidence that adding brief BWL to the WW program improves outcome.
Possible risk factors for increased suicide following bariatric surgery
Authors: Mitchell James E. , Crosby Ross , de Zwaan Martina , Engel Scott , Roerig James , Steffen Kristine , Gordon Kathryn H. , Karr Trisha , Lavender Jason , Wonderlich Steve
Published: May 2013

Objective:

There is a growing research literature suggesting that there may be elevated risk of suicide following bariatric surgery. Most of the data reported thus far has been cross‐sectional and observational, and very little is known about the possible specific causal variables involved.

Design and Methods:

The purpose of this report is to review this literature and to review possible risk factors for increased suicidal risk following bariatric surgery, to delineate future research directions.

Results:

First a variety of medical, biological, and genetic factors, including the persistence or recurrence of medical comorbidities after bariatric surgery, the disinhibition and impulsivity secondary to changes in the absorption of alcohol, hypoglycemia, as well as pharmacokinetic changes that may affect the absorption of various medications including antidepressant medications are reviewed. Also reviewed are possible mediating factors involving changes in various peptidergic systems such as GLP‐1 and Ghrelin. A number of psychosocial issues that might be involved are discussed, including lack of improvement in quality of life after surgery, continued or recurrent physical mobility restrictions, persistence or recurrence of sexual dysfunction and relationship problems, low self‐esteem, and a history of child maltreatment. Inadequate weight loss or weight regain are also discussed.

Conclusions:

A number of possible contributing factors have been identified. Possible theoretical models involved and directions for research are suggested.
Effect of dietary composition of weight loss diets on high‐sensitivity c‐reactive protein: The Randomized POUNDS LOST trial
Authors: Nicklas Jacinda M. , Sacks Frank M. , Smith Steven R. , LeBoff Meryl S. , Rood Jennifer C. , Bray George A. , Ridker Paul M
Published: May 2013

Objective:

Overweight and obesity are associated with increased high‐sensitivity C‐reactive protein (hsCRP) levels. The purpose of this study was to determine if weight loss diets differing in fat, protein, or carbohydrate composition differentially reduce hsCRP.

Design and Methods:

POUNDS (preventing overweight using novel dietary strategies) LOST was a 2‐year trial of overweight and obese adults randomly allocated to one of four weight loss diets with targeted percentages of energy derived from fat, protein, and carbohydrates (20, 15, 65%; 20, 25, 55%; 40, 15, 45%; 40, 25, 35%, respectively). hsCRP was measured at baseline, 6, and 24 months among 710 participants, and adiposity as measured by dual X‐ray absorptiometry (N = 340) or abdominal computed tomography (N = 126) was correlated with hsCRP change.

Results:

At 6 months, hsCRP was reduced in all trial participants by −24.7% (Interquartile range (IQR) +7%, −50%), weight by −6.7% (IQR −3%, −11%), and waist circumference by −6.0% (IQR −3%, −10%) (all P < 0.002), with no significant differences according to dietary composition. The percent change in hsCRP at 6 and 24 months correlated modestly with change in weight, waist circumference, fasting insulin, fasting glucose, HOMA, and most lipid levels. Reductions in hsCRP persisted despite ∼ 50% regain of weight by 24 months. The percent change in hsCRP at 24 months significantly correlated with changes in total body fat (r = 0.42), total abdominal adiposity (r = 0.52), subcutaneous abdominal adiposity (r = 0.52), visceral adiposity (r = 0.47), and hepatic tissue density (r = −0.34) (all P < 0.0006).

Conclusion:

Weight loss decreased hsCRP by similar magnitude, irrespective of dietary composition. Clinicians concerned about inflammation and cardiovascular risk should recommend weight loss diets most likely to succeed for their patients.
Insurer and employer views on pediatric obesity treatment: A qualitative study
Authors: Hampl S.E. , Davis A.M. , Sampilo M.L. , Stephens K.L. , Dean K.
Published: May 2013

Objective:

The effectiveness of group‐based comprehensive, multidisciplinary (stage 3) pediatric weight management programs is backed by a growing body of literature, yet insurance coverage of these programs is scarce to nonexistent, limiting their reach and long‐term survival. The objective of this study was to better understand the perspectives of insurers and large employers on the issue of group‐based treatment coverage.

Design and Methods:

The authors performed a qualitative study utilizing structured interviews with these stakeholders, following accepted techniques.

Results:

Six major themes emerged: cost, program effectiveness, corporate social responsibility, secondary parental (employee) benefits, coverage options and new benefit determination.

Conclusion:

Future efforts to secure payment for group‐based pediatric weight management programs should address these key themes.
Internet marketing directed at children on food and restaurant websites in two policy environments
Authors: Kent M. Potvin , Dubois L. , Kent E. A. , Wanless A. J.
Published: May 2013

Objective:

Food and beverage marketing has been associated with childhood obesity yet little research has examined the influence of advertising policy on children's exposure to food/beverage marketing on the Internet. The purpose of this study was to assess the influence of Quebec's Consumer Protection Act and the self‐regulatory Canadian Children's Food and Beverage Advertising Initiative (CAI) on food manufacturer and restaurant websites in Canada.

Design and Methods:

A content analysis of 147 French and English language food and restaurant websites was undertaken. The presence of child‐directed content was assessed and an analysis of marketing features, games and activities, child protection features, and the promotion of healthy lifestyle messages was then examined on those sites with child‐directed content.

Results:

There were statistically no fewer French language websites (n = 22) with child‐directed content compared to English language websites (n = 27). There were no statistically significant differences in the number of the various marketing features, or in the average number of marketing features between the English and French websites. There were no fewer CAI websites (n = 14) with child‐directed content compared to non‐CAI websites (n = 13). The CAI sites had more healthy lifestyle messages and child protection features compared to the non‐CAI sites.

Conclusion:

Systematic surveillance of the Consumer Protection Act in Quebec is recommended. In the rest of Canada, the CAI needs to be significantly expanded or replaced by regulatory measures to adequately protect children from the marketing of foods/beverages high in fat, sugar, and sodium on the Internet.
A cross‐sectional study of osteocalcin and body fat measures among obese adolescents
Authors: Lenders Carine M. , Lee Phillip D.K. , Feldman Henry A. , Wilson Darrell M. , Abrams Stephanie H. , Gitelman Stephen E. , Klish William J. , Wertz Marcia S. , Taylor George A. , Alongi Richard T. , Chen Tai C. , Holick Michael F. ,   for the Elisabeth Glaser Pediatric Research Network Obesity Study Group
Published: May 2013

Osteocalcin (OCN), a marker of osteoblast activity, has been implicated in the regulation of energy metabolism by the skeleton and thus may affect body fat measures.

Objective:

To examine the relationships of OCN to body fat measures and whether they vary according to markers of energy and vitamin D metabolism.

Design and Methods:

Data were obtained from 58 obese adolescents aged 13‐17.9 years (38 females, 8 black or African‐American). Total fat mass (FM) [dual X‐ray absorptiometry (DXA)] and visceral adipose tissue (VAT) [computerized axial tomography (CT)] were calculated. Blood tests included leptin, OCN, 25‐hydroxyvitamin D [25(OH)D], parathyroid hormone (PTH), thyroid function tests, and triglycerides. Markers of glucose metabolism were obtained from fasting and OGTT samples.

Results and Conclusions:

Adolescents with 25(OH)D <20 ng mL−1 were considered deficient (n = 17/58); none had high PTH (PTH ≥ 65 pg mL−1). OCN was associated with lower VAT (−84.27 ± 33.89 mm2) and BMI (−0.10 ± 0.05 kg m−2), not FM (P = 0.597) in a core model including age, sex, race, geographic latitude, summer, height z‐score, and tanner stage. Adding 25(OH)D deficiency and PTH attenuated the inverse association of OCN to VAT. There was a significant interaction of OCN and 25(OH)D deficiency on FM (0.37 ± 0.18 kg, P = 0.041) and BMI (0.28 ± 0.10 kg m−2, P = 0.007) in this adjusted model, which was further explained by leptin. Adding A1C to the core model modified the relationship of OCN to VAT (−93.08 ± 35.05 mm2, P = 0.011), which was further explained by HOMA‐IR. In summary, these findings provide initial evidence for a relationship between OCN and body fat measures that is dependent on energy metabolism and vitamin D status among obese adolescents.
Parental obesity moderates the relationship between childhood appetitive traits and weight
Authors: Fuemmeler Bernard F. , Lovelady Cheryl A. , Zucker Nancy L. , Østbye Truls
Published: May 2013

Objective:

In this study, the independent and combined associations between childhood appetitive traits and parental obesity on weight gain from 0 to 24 months and body mass index (BMI) z‐score at 24 months in a diverse community‐based sample of dual parent families (n = 213) were examined.

Design and Methods:

Participants were mothers who had recently completed a randomized trial of weight loss for overweight/obese postpartum women. As measures of childhood appetitive traits, mothers completed subscales of the Children's Eating Behavior Questionnaire, including Desire to Drink (DD), Enjoyment of Food (EF), and Satiety Responsiveness (SR), and a 24‐h dietary recall for their child. Heights and weights were measured for all children and mothers and self‐reported for mothers' partners. The relationship between children's appetitive traits and parental obesity on toddler weight gain and BMI z‐score were evaluated using multivariate linear regression models, controlling for a number of potential confounders.

Results:

Having two obese parents was related to greater weight gain from birth to 24 months independent of childhood appetitive traits, and although significant associations were found between appetitive traits (DD and SR) and child BMI z‐score at 24 months, these associations were observed only among children who had two obese parents. When both parents were obese, increasing DD and decreasing SR were associated with a higher BMI z‐score.

Conclusions:

The results highlight the importance of considering familial risk factors when examining the relationship between childhood appetitive traits on childhood obesity.
Association between adiponectin and heart failure risk in the physicians' health study
Authors: Djoussé Luc , Wilk Jemma B. , Hanson Naomi Q. , Glynn Robert J. , Tsai Michael Y. , Gaziano J. Michael
Published: May 2013

Objective:

To assess the association between adiponectin and incident heart failure (HF).

Design and Methods:

In the current ancillary study to the Physicians' Health Study (PHS), we used a prospective nested case‐control design to examine whether plasma adiponectin concentration was related to the risk of HF. We selected 787 incident HF cases and 787 matched controls for the current analysis. Each control was selected using a risk set sampling technique at the time of the occurrence of the index case and matched on year of birth, age at blood collection, and race. Adiponectin was measured using enzyme‐linked immunosorbent assay. HF occurrence was self‐reported in annual follow‐up questionnaire. Validation of self‐reported HF in this cohort has been published.

Results:

The mean age was 58.7 years. In a conditional logistic regression adjusting for age, race, time of blood collection, year of birth, hypertension, atrial fibrillation, smoking, alcohol intake, and exercise, estimates of the relative risk (95% confidence interval) were 1.0 (reference), 0.74 (0.53‐1.04), 0.67 (0.48‐0.94), 0.70 (0.50‐0.99), and 0.92 (0.65‐1.30) from the lowest to the highest quintile of adiponectin, respectively, P for quadratic trend 0.004. Additional adjustment for potential mediating factors including diabetes, C‐reactive protein, and BMI led to the attenuation of the estimate of effect (1.0 (reference), 0.81 (0.57‐1.15), 0.75 (0.53‐1.06), 0.83 (0.58‐1.18), and 1.26 (0.87‐1.81) across consecutive quintiles of adiponectin).

Conclusions:

Our data are consistent with a J‐shaped association between total adiponectin and the risk of HF among US male physicians.
Gastric bypass does not normalize obesity‐related changes in ghrelin profile and leads to higher acylated ghrelin fraction
Authors: Barazzoni Rocco , Zanetti Michela , Nagliati Carlo , Cattin Maria Rosa , Ferreira Clara , Giuricin Michela , Palmisano Silvia , Edalucci Elisabetta , Dore Franca , Guarnieri Gianfranco , de Manzini Nicolò
Published: May 2013

Objective:

Gastric bypass (GBP) lowers food intake, body weight, and insulin resistance in severe obesity (SO). Ghrelin is a gastric orexigenic and adipogenic hormone contributing to modulate energy balance and insulin action. Total plasma ghrelin (T‐Ghr) level is low and inversely related to body weight and insulin resistance in moderately obese patients, but these observations may not extend to the orexigenic acylated form (A‐Ghr) whose plasma concentration increase in moderate obesity.

Design and Methods:

We investigated the impact of GBP on plasma T‐, A‐, and A/T‐Ghr in SO patients (n = 28, 20 women), with measurements at baseline and 1, 3, 6, and 12 months after surgery. Additional cross‐sectional comparison was performed between nonobese, moderately obese, and SO individuals before GBP and at the end of the follow‐up period.

Results:

Before GBP, SO had lowest T‐Ghr and highest A/T‐Ghr profile compared with both nonobese and moderately obese individuals. Lack of early (0‐3 months from GBP) T‐Ghr changes masked a sharp increase in A‐Ghr and A/T‐Ghr profile (P < 0.05) that remained elevated following later increments (6‐12 months) of both T‐ and A‐Ghr (P < 0.05). Levels of A‐Ghr and A/T‐Ghr at 12 months of follow‐up remained higher than in matched moderately obese individuals not treated with surgery (P < 0.05).

Conclusions:

The data show that following GBP, early T‐Ghr stability masks elevation of A/T‐Ghr, that is stabilized after later increments of both T‐ and A‐hormones. GBP does not normalize the obesity‐associated elevated A/T‐Ghr ratio, instead resulting in enhanced A‐Ghr excess. Excess A‐Ghr is unlikely to contribute to, and might limit, the common GBP‐induced declines of appetite, body weight, and insulin resistance.
Expression of activating transcription factor 2 in inflammatory macrophages in obese adipose tissue
Authors: Miyata Yugo , Fukuhara Atsunori , Otsuki Michio , Shimomura Iichiro
Published: May 2013

Objective:

White adipose tissue (WAT) of obesity is in the state of inflammation with progressive infiltration by macrophages and overproduction of reactive oxygen species (ROS), which can induce WAT dysfunction, including insulin resistance and adipocytokine dysregulation. Activating transcription factor 2 (ATF2) is a member of the ATF/cAMP response element binding family of transcription factors and known to be activated by cellular stressors, such as inflammatory cytokines, lipopolysaccharide (LPS), and ROS.

Design and Methods, Results:

Here, we show that ATF2 protein was significantly more induced in WAT of ob/ob mice compared with C57BL/6J mice. Total and phosphorylated ATF2 were highly expressed in infiltrated macrophages. Furthermore, flow cytometry analysis demonstrated that ATF2 expression was high in CD11c‐positive/CD301‐negative M1 macrophages. Phosphorylation of ATF2 was induced by treatment with either H2O2 or LPS in RAW264.7 macrophage cells, and suppression of ATF2 expression by small‐interfering RNA induced mRNA levels of ATF3, an anti‐inflammatory molecule in macrophages in WAT.

Conclusions:

These results suggest that ATF2 is an important transcriptional factor relating to inflammation through the suppression of ATF3 in M1 macrophages of WAT.
The effects of NOD activation on adipocyte differentiation
Authors: S. Purohit Jaanki , Hu Pan , Burke Susan J. , Collier J. Jason , Chen Jiangang , Zhao Ling
Published: May 2013

Objective:

Obesity is associated with chronic inflammation. Toll‐like receptors (TLR) and NOD‐like receptors (NLR) are two families of pattern recognition receptors that play important roles in immune response and inflammation in adipocytes. It has been reported that TLR4 and TLR2 activation induce proinflammatory changes that impair adipocyte differentiation. However, the effects of activation of NOD1 and NOD2, the two prominent members of NLR, on adipocyte differentiation have not been studied.

Design and Methods:

3T3‐L1 and human adipose‐derived stem cells were tested for adipocyte differentiation in the presence or absence of NOD ligand. Adipocyte differentiation was evaluated by the adipocyte markers gene expression and Oil Red O staining for lipid accumulation.

Results:

Activation of NOD1, but not NOD2, by a synthetic ligand dose‐dependently suppressed 3T3‐L1 adipocyte differentiation as revealed by Oil Red O stained cell morphology, lipid accumulation, and attenuated gene expression of adipocyte markers (PPARγ, C/EBPα, SCD, FABP4, Adiponectin). Activation of NOD1, but not NOD2, induced NF‐κB activation, which correlated with their abilities to suppress ligand‐induced PPARγ transaction. Moreover, the suppressive effect by NOD1 activation was reversed by IκB super‐repressor which blocks NF‐κB activation. The suppression by NOD1 ligand C12‐iEDAP on adipocyte differentiation was reversed by small RNA interference targeting NOD1, demonstrating the specificity of NOD1 activation. In contrast, activation of NOD1 and NOD2 both significantly suppressed adipocyte differentiation of human adipose‐derived adult stem cells, demonstrating the species specific effects of NOD activation. In contrast to enhanced leptin mRNA by LPS and TNFα, NOD1 activation suppressed leptin mRNA in adipocytes, suggesting the differential effects of NOD1 activation in adipocytes.

Conclusions:

Overall, our results suggest that NOD1 represents a novel target for adipose inflammation in obesity.
Intestinal Methanobrevibacter smithii but not total bacteria is related to diet‐induced weight gain in rats
Authors: Mathur Ruchi , Kim Gene , Morales Walter , Sung Jaekyu , Rooks Emily , Pokkunuri Venkata , Weitsman Stacy , Barlow Gillian M. , Chang Christopher , Pimentel Mark
Published: May 2013

It is increasingly understood that gastrointestinal (GI) methanogens, including Methanobrevibacter smithii, influence host metabolism.

Objective:

Therefore, we compared M. smithii colonization and weight gain in a rat model under different dietary conditions.

Design and Methods:

Sprague‐Dawley rats were inoculated with M. smithii or vehicle (N = 10/group), fed normal chow until day 112 postinoculation, high‐fat chow until day 182, then normal chow until day 253. Thereafter, five rats from each group were fed high‐fat and normal chow until euthanasia.

Results:

Both groups exhibited M. smithii colonization, which increased following inoculation only for the first 9 days. Change to high‐fat chow correlated with significant increases in weight (P < 0.00001) and stool M. smithii (P < 0.01) in all rats, with stool M. smithi decreasing on return to normal chow. Rats switched back to high‐fat on day 253 further increased weight (P < 0.001) and stool M. smithii (P = 0.039). Euthanasia revealed all animals had higher M. smithii, but not total bacteria, in the small intestine than in the colon. Rats switched back to high‐fat chow had higher M. smithii levels in the duodenum, ileum, and cecum than those fed normal chow; total bacteria did not differ in any bowel segment. Rats which gained more weight had more bowel segments colonized, and the lowest weight recorded was in a rat on high‐fat chow which had minimal M. smithii colonization.

Conclusions:

We conclude that M. smithii colonization occurs in the small bowel as well as in the colon, and that the level and extent of M. smithii colonization is predictive of degree of weight gain in this animal model.
PKCθ expression in the amygdala regulates insulin signaling, food intake and body weight
Authors: Park‐York MieJung , Boghossian Stéphane , Oh Hyoungil , York David A.
Published: May 2013

Objective:

To investigate the signaling mechanisms that might underlie the loss of anorectic response to insulin injections into the central nucleus of the amygdala (CeA) within 3 days of feeding a high fat diet.

Design and Methods:

Protein samples from amygdala and hypothalamus of rats fed high or low fat diets were subjected to a phosphorylation screening assay. The effects of dietary fat intake on the expression and activation of protein kinase C theta (PKCθ) in brain regions was studied. Finally, lentiviral vectors were used to overexpress rat PKCθ unilaterally or bilaterally into the CeA of rats and the effects on food intake, body weight and insulin stimulation of Akt phosphorylation were studied.

Results:

The level of pMARCKS (Myristoylated alanine‐rich C‐kinase substrate), a major substrate of PKCθ, was increased 116% in amygdala of high fat diet fed rats but reduced in the hypothalamus. High fat diets increased the level of PKCθ in a region specific manner in the brain and this PKCθ was activated by membrane association. Overexpressing rat PKCθ either unilaterally or bilaterally into the CeA inhibited insulin stimulation of Akt signaling and blocked the anorectic response to insulin injected into the amygdala. Bilaterally injected PKCθ rats gained more weight and body fat and had increased food intake when fed a high fat diet compared to the control rats that received a lentiviral‐Green Fluorescent Protein construct.

Conclusion:

The data suggest that insulin may have a physiological role within the amygdala to regulate energy balance.
Body adiposity index and other indexes of body composition in the SAPHIR study: Association with cardiovascular risk factors
Authors: Melmer Andreas , Lamina Claudia , Tschoner Alexander , Ress Claudia , Kaser Susanne , Laimer Markus , Sandhofer Anton , Paulweber Bernhard , Ebenbichler Christoph F.
Published: May 2013

Objective:

The accuracy of anthropometric surrogate markers such as the body adiposity index (BAI) and other common indexes like the body mass index (BMI), waist‐to‐hip ratio (WHR) and waist‐to‐height ratio (WHtR) to predict metabolic sequelae is essential for its use in clinical practice.

Design and Methods:

Thus, we evaluated the strength of BAI and other indexes to relate with anthropometric parameters, adipocytokines, blood lipids, parameters of glucose‐homeostasis and blood pressure in 1,770 patients from the Salzburg Atherosclerosis Prevention Program in Subjects at High Individual Risk (SAPHIR) study in a crosssectional design.

Measurements were BAI, BMI, WHR, WHtR, abdominal subcutaneous and visceral adipose tissue (aSAT and VAT), total body adipose tissue mass, body weight, waist‐ and hip circumference (WC and HC), leptin, adiponectin, high‐density lipoprotein‐cholesterol (HDL‐C), low‐density lipoprotein‐cholesterol (LDL‐C), triglycerides (TG), fasting plasma glucose, fasting plasma insulin, the homeostasis model assessment of insulin resistance (HOMAIR), systolic and diastolic blood pressure.

Results and Conclusions:

BAI was significantly associated with leptin and HC. We conclude that BAI was the best calculator for leptin. BAI was inferior to BMI to predict anthropometric parameters other than HC, adiponectin, blood lipids, parameters of glucose homeostasis, and blood pressure in this cross‐sectional study.
SCHOOL PSYCHOLOGIST DIAGNOSTIC DECISION‐MAKING: A PILOT STUDY
Authors: Barnard‐Brak Lucy , Stevens Tara , Robinson Eric , Holt Ann
Published: May 2013

The current study examined the diagnostic decision‐making of school psychologists as a function of a student's disability and academic performance with three research questions using a randomly‐selected sample of school psychologists from the state of Texas. Results from the first research question indicated that school psychologists significantly differentiated between what diagnoses were considered most correct according to the DSM‐IV and what diagnoses would be in a child's best interest at school. Results from the second research question indicated that this differentiation in diagnostic decision‐making was present as significantly associated with academic performance. Results from the third and final research question indicated that school psychologists differed in their diagnostic decision‐making according to their perceptions about the particular disability.
COMU: scope and limitations of the latest innovation in peptide acyl transfer reagents
Authors: Subirós‐Funosas Ramon , Nieto‐Rodriguez Lidia , Jensen Knud J. , Albericio Fernando
Published: May 2013

The methodology for peptide bond formation is undergoing a continuous evolution where the main actors are being renewed. In recent years, coupling reagents based on the Oxyma scaffold, such as the uronium salt COMU, has been a groundbreaking contribution to the field. The advantages of COMU over classic benzotriazole‐based reagents (HATU, HBTU, HCTU, TBTU) were proven in terms of solubility and coupling efficiency in bulky junctions in our groups and others. However, some aspects of the use of COMU need to be revised and improved, such as the stability of commercial samples in organic solvents, which hampers the compatibility with long synthesis in automated synthesizers. In this review, an overview of the main features and suggestions to improve the use of COMU are presented, along with a discussion on the best conditions for its use in microwave‐assisted peptide robots. Copyright © 2013 European Peptide Society and John Wiley & Sons, Ltd.
Mass spectrometric characterization of halogenated flame retardants
Authors: Guo Tan , LaBelle Bruce , Petreas Myrto , Park June‐Soo
Published: May 2013

RATIONALE

Concerns about the adverse health effects of ubiquitous flame retardants spurred our interest in the development of a sensitive and reliable analytical method for these toxic compounds in various sample matrices. This study focuses on the investigation of fragmentation pathways and the structures of target ions of thirteen new halogenated flame retardants.

METHODS

In this study, we use gas chromatography (GC)/high‐resolution double‐focusing sector mass spectrometry to characterize the fragmentation pathways of these new flame retardants. Along with the isotope patterns, accurate mass data were acquired to verify the molecular formula.

RESULTS

The fragmentation pathways are classified based on the types of bond dissociations, e.g. σ‐bond cleavage, α‐bond cleavage and multiple‐bond dissociations with a hydrogen shift. The α‐bond dissociation occurs among 1,2‐bis‐(2,4,6‐tribromophenoxy)ethane, allyl 2,4,6‐tribromophenyl ether (ATE), 2,3‐dibromopropyl 2,4,6‐tribromophenyl ether (DPTE) and 2‐bromoallyl 2,4,6‐tribromophenyl ether (BATE). The peak clusters that dominated ATE, BATE and hexachlorocyclopentenyl‐dibromocyclooctane (HCDBCO) spectra correspond to two fragments as proved by accurate mass data and isotope patterns. These two fragments are formed as the result of two competing fragmentation pathways of radical loss and hydrogen shift. Fragmentation pathways of the other compounds are complex, involving cleavage of multiple bonds and hydrogen shifts.

CONCLUSIONS

The accurate‐mass‐based GC/MS method offers great selectivity and sensitivity for quantitative analysis of the persistent organic pollutants. Thus, elucidation of the structures of the fragments is of prime importance for building an accurate‐mass‐based isotopic method. In addition, this study is useful for GC/MS/MS method development because multiple reaction monitoring (MRM) transitions of precursor ions and product ions may be easily elucidated based on these fragmentation patterns. Copyright © 2013 John Wiley & Sons, Ltd.
A differential mobility spectrometry/mass spectrometry platform for the rapid detection and quantitation of DNA adduct dG‐ABP
Authors: Kafle Amol , Klaene Joshua , Hall Adam B. , Glick James , Coy Stephen L. , Vouros Paul
Published: May 2013

RATIONALE

There is continued interest in exploring new analytical technologies for the detection and quantitation of DNA adducts, biomarkers which provide direct evidence of exposure and genetic damage in cells. With the goal of reducing clean‐up steps and improving sample throughput, a Differential Mobility Spectrometry/Mass Spectrometry (DMS/MS) platform has been introduced for adduct analysis.

METHODS

A DMS/MS platform has been utilized for the analysis of dG‐ABP, the deoxyguanosine adduct of the bladder carcinogen 4‐aminobiphenyl (4‐ABP). After optimization of the DMS parameters, each sample was analyzed in just 30 s following a simple protein precipitation step of the digested DNA.

RESULTS

A detection limit of one modification in 10^6 nucleosides has been achieved using only 2 µg of DNA. A brief comparison (quantitative and qualitative) with liquid chromatography/mass spectrometry is also presented highlighting the advantages of using the DMS/MS method as a high‐throughput platform.

CONCLUSIONS

The data presented demonstrate the successful application of a DMS/MS/MS platform for the rapid quantitation of DNA adducts using, as a model analyte, the deoxyguanosine adduct of the bladder carcinogen 4‐aminobiphenyl. Copyright © 2013 John Wiley & Sons, Ltd.
Isotopomer and isotopologue signatures of N2O produced in alpine ecosystems on the Qinghai–Tibetan Plateau
Authors: Kato Tomomichi , Toyoda Sakae , Yoshida Naohiro , Tang Yanhong , Wada Eitaro
Published: May 2013

RATIONALE

Static‐chamber flux measurements have suggested that one of the world's largest grasslands, the Qinghai‐Tibetan Plateau (QTP), is a potential source of nitrous oxide (N2O), a major greenhouse gas. However, production and consumption pathways of N2O have not been identified by in situ field measurements.

METHODS

Ratios of N2O isotopomers (14N15N16O and 15N14N16O) and an isotopologue (14N14N18O) with respect to 14N14N16O in the atmosphere, static chambers, and soils were measured by gas chromatography and mass spectrometry in the summer of 2005 and the following winter of 2006 at three typical alpine ecosystems: alpine meadow, alpine shrub, and alpine wetland, on the QTP, China.

RESULTS

Site preference (SP) values of soil‐emitted N2O were estimated as 33.7‰ and 30.1‰ for alpine meadow and shrub, respectively, suggesting larger contributions by fungal denitrification, than by bacterial denitrification and nitrifier‐denitrification, to N2O production. Statistical analysis of the relationship between SP and δ15Nbulk values indicated that in alpine meadow, shrub, and wetland sites fungal denitrification contributed 40.7%, 40.0%, and 23.2% to gross N2O production and the produced N2O was reduced by 87.6%, 82.9%, and 92.7%, respectively.

CONCLUSIONS

The combined measurements of N2O concentration, flux, and isotopomeric signatures provide a robust estimation of N2O circulation dynamics in alpine ecosystems on the QTP, which would contribute to the development of ecosystem nitrogen cycle model. Copyright © 2013 John Wiley & Sons, Ltd.
Mass spectral characterization of the CWC‐related isomeric dialkyl alkylphosphonothiolates/alkylphosphonothionates under gas chromatography/mass spectrometry conditions
Authors: Karthikraj R. , Sridhar L. , Prabhakar S. , Raju N. Prasada , Murty M. R. V. S. , Vairamani M.
Published: May 2013

RATIONALE

The isomeric dialkyl alkylphosphonothiolates and dialkyl alkylphosphonothionates are listed as scheduled chemicals of the Chemical Weapons Convention (CWC) implemented by the OPCW. The P–S and P–R bond connectivity has to be correctly identified for the verification of the CWC. The present study demonstrates successful identification of the target isomers by selective fragmentation under electron ionization (EI) or chemical ionization (CI) conditions.

METHODS

All the studied isomeric compounds (27 in total) were synthesized in our laboratory using established methods, then analyzed by EI and CI gas chromatography/mass spectrometry (GC/MS) using an Agilent 6890 gas chromatograph equipped with a HP‐5MS capillary column and interfaced to a 5973 N mass‐selective detector. The retention index (RI) values of all the compounds were calculated using Van den Dool's formula. GC/MS/MS and GC/HRMS experiments were also performed using a VG‐Autospec (magnetic sector) and JEOL‐AccuToF (time‐of‐flight) mass spectrometer, respectively.

RESULTS

The EI mass spectra of all the compounds had an abundant molecular ion at m/z 182, except in the case of a few selected butyl‐substituted compounds, where this ion was of low abundance. The EI fragmentation pathways include α‐cleavage, McLafferty rearrangement, McLafferty + 1 rearrangement, O/S‐alkyl radical loss, and an alkene loss with a hydrogen shift. The characteristic fragment ions and their relative abundances are significant in elucidating the alkyl group attached to the P/S/O‐atoms as well as the P–S/P = S bond connectivity. The EI and CI mass spectra together with RI values enable unambiguous identification of all the studied isomeric compounds.

CONCLUSIONS

The present study highlights the structural characterization of the isomeric phosphonothiolates and phosphonothionates based on their selective EI fragmentation. The assigned fragmentation pathway helps in the assignment of P–S and P–alkyl connectivity in phosphonothiolates and phosphonothionates, consequently the structure of the unknown compounds. The EI mass spectra (27 compounds) of isomeric compounds are immensely useful in the OPCW official proficiency tests and for off‐site analysis. Copyright © 2013 John Wiley & Sons, Ltd.
Peptide dissociation patterns in secondary ion mass spectrometry under large argon cluster ion bombardment
Authors: Gnaser Hubert , Fujii Makiko , Nakagawa Shunichirou , Seki Toshio , Aoki Takaaki , Matsuo Jiro
Published: May 2013

RATIONALE

The analysis of organic and biological substances by secondary ion mass spectrometry (SIMS) has greatly benefited from the use of cluster ions as primary bombarding species. Thereby, depth profiling and three‐dimensional (3D) imaging of such systems became feasible. Large Arn+ cluster ions may constitute a further improvement in this direction.

METHODS

To explore this option, large Arn+ cluster ions (with n ~1500 Ar atoms per cluster) were used to investigate the emission of positive secondary ions from two peptide specimens (angiotensin I and bradykinin) by orthogonal time‐of‐flight SIMS using bombarding energies 6, 10 and 14 keV.

RESULTS

For both peptides, the protonated molecular ion is observed in the mass spectra. In addition, distinct fragmentation patterns were observed; these indicate that fragment ions under Ar cluster irradiation form primarily via cleavage of bonds along the peptide backbone whereas the rapture of side chains occurs much less frequently. These features appear to be similar to low‐energy collision‐induced dissociation pathways.

CONCLUSIONS

Tentatively, these findings can then be ascribed to the concerted action of the large number of Ar atoms in the impact zone of cluster at the surface: these low‐energy Ar species (with an average energy of few eV) may effect the cleavage of the peptide bonds and lead, eventually, to the emission of the fragment ions. Copyright © 2013 John Wiley & Sons, Ltd.
Minimally invasive fetal therapy for hydropic lung masses: three different approaches and review of the literature
Authors: Baud D. , Windrim R. , Kachura J. R. , Jefferies A. , Pantazi S. , Shah P. , Langer J. C. , Forsey J. , Chaturvedi R. R. , Jaeggi E. , Keating S. , Chiu P. , Ryan G.
Published: May 2013

Objective

To report three different antenatal therapeutic approaches for fetal lung masses associated with hydrops.

Methods

Three prospectively followed cases are described, and all 30 previously published minimally invasive cases of fetal therapy for hydropic lung masses are reviewed.

Results

Three hydropic fetuses with large intrathoracic lung masses presented at 17, 25 and 21 weeks of gestation, respectively. An aortic feeding vessel was identified in each case and thus a bronchopulmonary sequestration (BPS) was suspected. Under ultrasound guidance, the feeding vessel was successfully occluded with interstitial laser (Case 1), radiofrequency ablation (RFA) (Case 2) and thrombogenic coil embolization (Case 3). Complete (Cases 1 and 2) or partial (Case 3) resolution of the lung mass and hydrops was observed. A healthy infant was born at term after laser therapy (Case 1), and the involved lung lobe was resected on day 2 of postnatal life. In Case 2, hydrops resolved completely following RFA, but an iatrogenic congenital diaphragmatic hernia and abdominal wall defect became apparent 4 weeks later. The neonate died from sepsis following spontaneous preterm labor at 33 weeks. In Case 3, despite technical success in complete vascular occlusion with coils, a stillbirth ensued 2 days after embolization.

Conclusions

The prognosis of large microcystic or echogenic fetal chest masses associated with hydrops is dismal. This has prompted attempts at treatment by open fetal surgery, with mixed results, high risk of premature labor and consequences for future pregnancies. We have demonstrated the possibility of improved outcome following ultrasound‐guided laser ablation of the systemic arterial supply. Despite technical success, RFA and coil embolization led to procedure‐related complications and need further evaluation. Copyright © 2013 ISUOG. Published by John Wiley & Sons Ltd.
Exploring 6D origins of 5D supergravities with Chern-Simons terms
Authors: Bonetti Federico , Grimm Thomas W. , Hohenegger Stefan
Published: May 2013

Abstract

We consider five-dimensional supergravity theories with eight or sixteen supercharges with Abelian vector fields and ungauged scalars. We address the question under which conditions these theories can be interpreted as effective low energy descriptions of circle reductions of anomaly free six-dimensional theories with (1,0) or (2,0) supersymmetry. We argue that classical and one-loop gauge- and gravitational Chern-Simons terms are instrumental for this question.