bluuebunny/crossref_metadata_2025 huggingface dataset:
Trends in the Prevalence of Overweight and Obesity among Young Australians, 1985, 1997, and 2004
Authors: Booth Michael L. , Dobbins Timothy , Okely Anthony D. , Denney‐Wilson Elizabeth , Hardy Louise L.
Published: July 2008

Objective: To determine secular trends in overweight/obesity among 7‐ to 15‐year‐olds for the periods 1985, 1997, and 2004.

Research Method and Procedures: Data from representative surveys conducted in New South Wales, Australia, in 1985, 1997, and 2004 were analyzed. Height and weight were measured, and BMI categories were created using International Obesity Task Force definitions. Students were grouped as Grades 2 + 4 + 6 and 8 + 10.

Results: The prevalences of overweight/obesity for 1985, 1997, and 2004 were 10.9%, 20.6%, and 25.7% among the younger boys and 10.6%, 19.5%, and 26.1% among the older boys. The average annual rate of increase for 1985 to 1997 was 0.81% and for 1997 to 2004 was 0.73% among the younger boys and was 0.74% and 0.94% for the two periods among the older boys. The prevalences of overweight/obesity in 1985, 1997, and 2004 were 14.0%, 22.0%, and 24.8% among the younger girls and 8.3%, 17.9%, and 19.8% among the older girls, respectively. The average annual rates of increase for the two periods were 0.8% and 0.4% among the younger girls and 0.80% and 0.27% among the older girls. Change in the prevalence of overweight/obesity and socioeconomic status were not associated.

Discussion: Over the period 1985 to 1997, the prevalence of overweight and obesity increased significantly among the younger and older boys and the younger girls. The prevalence of overweight, but not obesity, increased among the older girls over this period. Over the period 1997 to 2004, the prevalence of overweight/obesity combined increased significantly among boys of both age groups but not among girls.
Potential of Intestinal Electrical Stimulation for Obesity: A Preliminary Canine Study
Authors: Yin Jieyun , Ouyang Hui , Chen Jiande D.Z.
Published: July 2008

Objective: The aims of this study were to investigate the therapeutic potential of intestinal electrical stimulation (IES) for obesity. Experiments were performed to investigate the effects of IES on food intake, gastric tone, gastric accommodation, and its possible pathway.

Research Methods and Procedures: Ten normal dogs and six dogs with truncal vagotomy were used in this study. Each dog was equipped with a gastric cannula for the measurement of gastric tone and accommodation by barostat and one pair of duodenal serosal electrodes for IES. The experiment on food intake was composed of both control session without IES and IES session after a 28‐hour fast. The experiment on gastric tone and accommodation was performed in the fasting and fed states and composed of three sessions: control, IES, and IES with NG‐nitro‐l‐arginine.

Results: IES significantly reduced food intake in the normal dogs (459.0 vs. 312.6 grams, p < 0.001). The food intake was negatively correlated with the fasting gastric volume during IES. IES significantly decreased fasting gastric tone in the normal dogs reflected as a decrease in gastric volume (89.1 vs. 261.3 mL, p < 0.01), which was abolished by vagotomy and NG‐nitro‐l‐arginine.

Discussion: IES reduces food intake and inhibits gastric tone in the fasting state. The inhibitory effect of IES on gastric tone is mediated by both vagal and nitrergic pathway.
Relationships of Cardiac Autonomic Function With Metabolic Abnormalities in Childhood Obesity
Authors: Kaufman Christopher L. , Kaiser Daniel R. , Steinberger Julia , Kelly Aaron S. , Dengel Donald R.
Published: July 2008

Objective: The objective was to examine cardiovascular autonomic (cANS) function and its potential relationships with leptin resistance, insulin resistance, oxidative stress, and inflammation in a pediatric sample with varying levels of obesity.

Research Methods and Procedures: Participants were normal‐weight (NW; BMI <85th percentile, 6 male, 4 female), overweight (OW; 85th percentile < BMI <95th percentile, 6 male, 4 female), and obese children (OB; BMI >95th percentile, 6 male, 10 female) who had cANS function assessed via heart rate variability (HRV) methods during resting conditions. Standard time‐domain and frequency‐domain measures [high‐frequency normalized units (HFnu; measure of parasympathetic nervous system activity) and low frequency:high‐frequency ratio (LF:HF; overall sympathovagal balance)] of HRV were calculated. Fasting blood samples were drawn for measurement of glucose, insulin, lipids, 8‐isoprostane, leptin, soluble leptin‐receptor (sOB‐R), C‐reactive protein (CRP), interleukin‐6 (IL‐6), and tumor necrosis factor‐α (TNF‐α). Results were reported as mean ± standard error of the mean.

Results: OB had significantly elevated LF:HF and decreased HFnu when compared with NW (p < 0.05), but no differences between OW and NW were observed. Measures of HRV were significantly related to leptin, insulin resistance, 8‐isoprostane, and CRP (p < 0.05), but these relationships were not significant after adjustment for fat mass.

Discussion: When compared with NW, OB but not OW children are characterized by cANS dysfunction and increased leptin, insulin resistance, oxidative stress, and inflammation (CRP). The relationships between these factors seem to be dependent on quantity of fat mass and/or other factors associated with being obese.
Low‐dose Pramlintide Reduced Food Intake and Meal Duration in Healthy, Normal‐Weight Subjects
Authors: Chapman Ian , Parker Barbara , Doran Selena , Feinle‐Bisset Christine , Wishart Judith , Lush Cameron W. , Chen Kim , LaCerte Carl , Burns Colleen , McKay Robyn , Weyer Christian , Horowitz Michael
Published: July 2008

Objective:We previously reported that a single preprandial injection (120 μg) of pramlintide, an analog of the β‐cell hormone amylin, reduced ad libitum food intake in obese subjects. To further characterize the meal‐related effects of amylin signaling in humans, we studied a lower pramlintide dose (30 μg) in normal‐weight subjects.

Research Methods and Procedures:In a randomized, double‐blind, placebo‐controlled, cross‐over study, 15 healthy men (age, 24 ± 7 years; BMI, 22.2 ± 1.8 kg/m2) underwent a standardized buffet meal test on two occasions. After an overnight fast, subjects received a single subcutaneous injection of pramlintide (30 μg) or placebo, followed immediately by a standardized pre‐load meal. After 1 hour, subjects were offered an ad libitum buffet meal, and total caloric intake and meal duration were measured.

Results:Compared with placebo, pramlintide reduced total caloric intake (1411 ± 94 vs. 1190 ± 117 kcal; Δ, −221 ± 101 kcal; −14 ± 9%;p= 0.05) and meal duration (36 ± 2 vs. 31 ± 3 minutes; Δ, −5.1 ± 1.4 minutes;p< 0.005). Visual analog scale profiles of hunger trended lower and fullness higher during the first hour after pramlintide administration. In response to the buffet, hunger and fullness changed to a similar degree after pramlintide and placebo, despite subjects on pramlintide consuming 14% fewer kilocalories. Visual analog scale nausea ratings remained near baseline, without differences between treatments. Plasma peptide YY, cholecystokinin, and ghrelin concentrations did not differ with treatment, whereas glucagon‐like peptide‐1 concentrations after meals were lower in response to pramlintide than to placebo.

Discussion:These observations add support to the concept that amylin agonism may have a role in human appetite control.
Intake of Dietary Magnesium and the Prevalence of the Metabolic Syndrome among U.S. Adults
Authors: Ford Earl S. , Li Chaoyang , McGuire Lisa C. , Mokdad Ali H. , Liu Simin
Published: July 2008

Objective: Limited data suggest that people with the metabolic syndrome have lower intakes or circulating concentrations of magnesium than those who do not have the syndrome. The aim of this study was to examine the associations between dietary intake of magnesium and the prevalence of the metabolic syndrome in a nationally representative sample of U.S. adults.

Research Methods and Procedures: We used data for 7669 participants ≥20 years of age of the Third National Health and Nutrition Examination Survey (1988 to 1994). The metabolic syndrome was defined using the criteria of the National Cholesterol Education Program. Magnesium intake was determined from a single dietary 24‐hour recall.

Results: The unadjusted prevalences of the metabolic syndrome were 29.0% (quintile of lowest magnesium intake), 27.5%, 25.8%, 23.9%, and 21.8% for increasing quintiles of magnesium intake (p for trend = 0.002). After multiple adjustment, the odds ratios for the second through the fifth quintiles (highest intake) of magnesium intake among all participants included in the analysis were 0.84 [95% confidence interval (CI): 0.58, 1.23], 0.76 (95% CI: 0.54, 1.07), 0.62 (95% CI: 0.40, 0.98), and 0.56 (95% CI: 0.34, 0.92), respectively (p for trend = 0.029). The associations were similar for men and women.

Discussion: Our results showing an inverse association between dietary magnesium intake and the prevalence of the metabolic syndrome add to the evidence that adequate magnesium intake or a diet rich in magnesium may be important for maintaining good cardiometabolic health.
Peroxisome Proliferator‐activated Receptor γ 2 and Acyl‐CoA Synthetase 5 Polymorphisms Influence Diet Response
Authors: Adamo Kristi B. , Dent Robert , Langefeld Carl D. , Cox Miranda , Williams Kathryn , Carrick Kevin M. , Stuart Joan S. , Sundseth Scott S. , Harper Mary‐Ellen , McPherson Ruth , Tesson Frédérique
Published: July 2008

Peroxisome proliferator‐activated receptor γ (PPARγ) and its response gene, Acyl CoA synthetase 5 (ACSL5), which has an important role in fatty acid metabolism, may affect weight loss in response to caloric restriction. Therefore, we aimed to determine whether these genes were involved in the interindividual response to dietary treatment. Genotypic/phenotypic comparisons were made between selected obese women from the quintiles losing the most (diet responsive, n = 74) and the quintiles losing the least (diet‐resistant, n = 67) weight in the first 6 weeks of a 900‐kcal formula diet. Two common PPARγ single nucleotide polymorphisms, Pro12Ala and C1431T, and eight polymorphisms across the ACSL5 gene were selected for single locus and haplotypic association analyses. The PPARγ Pro12Ala single nucleotide polymorphism was associated with diet resistance (odds ratio = 3.48, 95% confidence interval = 1.41 to 8.56, p = 0.03), and the rs2419621, located in the 5′untranslated region of the ACSL5 gene, displayed the strongest association with diet response (odds ratio = 3.45, 95% confidence interval = 1.61 to 7.69, p = 0.001). Skeletal muscle ACSL5 mRNA expression was significantly lower in carriers of the wildtype compared with the variant rs2419621 allele (p = 0.03). Our results suggest a link between PPARγ2 and ACSL5 genotype and diet responsiveness.
Self‐identities and BMI of Minnesotan Soy Consumers and Non‐consumers
Authors: Schryver Tamara , Smith Chery , Wall Melanie
Published: July 2008

Objective: The purpose of this study was to identify self‐identities among mainstream and natural foods shoppers and the relationship of these self‐identities to soy consumption and BMI. We hypothesized that soy consumers (SCs) would have lower BMIs than non‐consumers (NCs) and that persons who self‐identify themselves as SCs, natural foods, organic foods, health conscious, whole foods consumers, and vegetarians would have higher intakes of soy.

Research Methods and Procedures: A validated soy foods frequency questionnaire was administered to 298 adult mainstream and natural foods grocery store shoppers in Minneapolis/St. Paul, MN. An additional survey gathered information on consumers’ self‐identification with several dietary and lifestyle descriptors. Principal component analysis was used to extract factors representing overarching self‐identities. Correlation coefficients between derived scales for each factor and BMI and soy servings per week were generated using a Spearman correlation. One‐way ANOVA was used to test significance between derived scales for factors and demographic variables and store type. Multiple regression models were used to test association between derived scales and BMI and soy servings per week while adjusting for demographic covariates.

Results: Asians and those who shopped at natural food grocery stores consumed more soy foods and had lower BMIs than other ethnicities or those who shopped at mainstream grocery stores. Five overarching self‐identities were found: vegetarian, mainstream, nouveau gourmet, pleasure, and bargain. Vegetarian and nouveau gourmet self‐identities consumed significantly greater amounts of soy foods and had significantly lower BMIs, whereas mainstream self‐identities consumed significantly less soy foods and had significantly higher BMIs.

Discussion: Self‐identities influence soy food consumption and BMI.
Biochemical function of typical and variant Arabidopsis thaliana U-box E3 ubiquitin-protein ligases
Authors: Wiborg Jakob , O'Shea Charlotte , Skriver Karen
Published: July 2008

The variance of the U-box domain in 64 Arabidopsis thaliana (thale cress) E3s (ubiquitin-protein ligases) was used to examine the interactions between E3s and E2s (ubiquitin-conjugating enzymes). E2s and E3s are components of the ubiquitin protein degradation pathway. Seven U-box proteins were analysed for their ability to ubiquitinate proteins in vitro in co-operation with different E2s. All U-box domains exhibited ubiquitination activity and interacted productively with UBC4/5-type E2s. Three and four of the U-box domains mediated ubiquitin addition in the presence of UBC13 and UBC7 E2s respectively, but no productive interaction was observed with the UBC15 E2 tested. The activity of AtPUB54 [Arabidopsis thaliana (thale cress) plant U-box 54 protein] was dependent on Trp266 in the E2-binding cleft, and the E2 selectivity was changed by substitution of this position. The function of the distant U-box protein, AtPUB49, representing a large family of eukaryotic proteins containing a U-box linked to a cyclophilin-like peptidyl-prolyl cis–trans isomerase domain, was characterized biochemically. AtPUB49 functioned both as a prolyl isomerase and a chaperone by catalysing cis–trans isomerization of peptidyl-prolyl bonds and dissolving protein aggregates. In conclusion, both typical and atypical Arabidopsis U-box proteins were active E3s. The overlap in the E3/E2 selectivity suggests that in vivo specificity is not determined only by the E3–E2 interactions, but also by other parameters, e.g. co-existence or interactions with additional domains. The biochemical functions of AtPUB49 suggest that the protein can be involved in folding or degradation of protein substrates. Similar functions can also be retained within a protein complex with separate chaperone and U-box proteins.
Receptor for advanced glycation end-products (RAGE) modulates neutrophil adhesion and migration on glycoxidated extracellular matrix
Authors: Touré Fatouma , Zahm Jean-Marie , Garnotel Roselyne , Lambert Elise , Bonnet Noel , Schmidt Ann Marie , Vitry Fabien , Chanard Jacques , Gillery Philippe , Rieu Philippe
Published: July 2008

AGEs (advanced glycation end-products) accumulate in collagen molecules during uraemia and diabetes, two diseases associated with high susceptibility to bacterial infection. Because neutrophils bind to collagen during their locomotion in extravascular tissue towards the infected area we investigated whether glycoxidation of collagen (AGE-collagen) alters neutrophil migration. Type I collagen extracted from rat tail tendons was used for in vitro glycoxidation (AGE-collagen). Neutrophils were obtained from peripheral blood of healthy adult volunteers and were used for the in vitro study of adhesion and migration on AGE- or control collagen. Glycoxidation of collagen increased adhesion of neutrophils to collagen surfaces. Neutrophil adhesion to AGE-collagen was inhibited by a rabbit anti-RAGE (receptor for AGEs) antibody and by PI3K (phosphoinositide 3-kinase) inhibitors. No effect was observed with ERK (extracellular-signal-regulated kinase) or p38 MAPK (mitogen-activated protein kinase) inhibitors. AGE-collagen was able to: (i) induce PI3K activation in neutrophils, and (ii) inhibit chemotaxis and chemokinesis of chemoattractant-stimulated neutrophils. Finally, we found that blocking RAGE with anti-RAGE antibodies or inhibiting PI3K with PI3K inhibitors restored fMLP (N-formylmethionyl-leucyl-phenylalanine)-induced neutrophil migration on AGE-collagen. These results show that RAGE and PI3K modulate adhesion and migration rate of neutrophils on AGE-collagen. Modulation of adhesiveness may account for the change in neutrophil migration rate on AGE-collagen. As neutrophils rely on their ability to move to perform their function as the first line of defence against bacterial invasion, glycoxidation of collagen may participate in the suppression of normal host defence in patients with diabetes and uraemia.
Elimination of competing hydrolysis and coupling side reactions of a cyclodextrin glucanotransferase by directed evolution
Authors: Kelly Ronan M. , Leemhuis Hans , Rozeboom Henriëtte J. , van Oosterwijk Niels , Dijkstra Bauke W. , Dijkhuizen Lubbert
Published: July 2008

Thermoanaerobacterium thermosulfurigenes cyclodextrin glucanotransferase primarily catalyses the formation of cyclic α-(1,4)-linked oligosaccharides (cyclodextrins) from starch. This enzyme also possesses unusually high hydrolytic activity as a side reaction, thought to be due to partial retention of ancestral enzyme function. This side reaction is undesirable, since it produces short saccharides that are responsible for the breakdown of the cyclodextrins formed, thus limiting the yield of cyclodextrins produced. To reduce the competing hydrolysis reaction, while maintaining the cyclization activity, we applied directed evolution, introducing random mutations throughout the cgt gene by error-prone PCR. Mutations in two residues, Ser-77 and Trp-239, on the outer region of the active site, lowered the hydrolytic activity up to 15-fold with retention of cyclization activity. In contrast, mutations within the active site could not lower hydrolytic rates, indicating an evolutionary optimized role for cyclodextrin formation by residues within this region. The crystal structure of the most effective mutant, S77P, showed no alterations to the peptide backbone. However, subtle conformational changes to the side chains of active-site residues had occurred, which may explain the increased cyclization/hydrolysis ratio. This indicates that secondary effects of mutations located on the outer regions of the catalytic site are required to lower the rates of competing side reactions, while maintaining the primary catalytic function. Subsequent functional analysis of various glucanotransferases from the superfamily of glycoside hydrolases also suggests a gradual evolutionary progression of these enzymes from a common ‘intermediate-like’ ancestor towards specific transglycosylation activity.
Regulation of transcription by the Epstein–Barr virus nuclear antigen EBNA 2
Authors: Palermo Richard D. , Webb Helen M. , Gunnell Andrea , West Michelle J.
Published: July 2008

The EBNA 2 (Epstein–Barr nuclear antigen 2) transcription factor is essential for B-cell transformation by the cancer-associated EBV (Epstein–Barr virus) and for the continuous proliferation of infected cells. EBNA 2 activates transcription from the viral Cp (C promoter) during infection to generate the 120 kb transcript that encodes all nuclear antigens required for immortalization by EBV. EBNA 2 contains an acidic activation domain and can interact with a number of general transcription factors and co-activators. It is now becoming clear, however, that the regulation of transcription elongation in addition to initiation by EBNA 2, at least in part through CDK9 (cyclin-dependent kinase 9)-dependent phosphorylation of the RNA polymerase C-terminal domain, is likely to play a crucial role in the mechanism of action of this key viral protein.
Progesterone regulation of RUSH/SMARCA3/HLTF includes DNA looping
Authors: Chilton Beverly S. , Hewetson Aveline
Published: July 2008

RUSH/SMARCA3 (SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily A, member 3) is capable of sequence-selective DNA binding and ATP-dependent DNA unwinding. In rabbit uterine epithelial cells, RUSH-1α (113 kDa) is the progesterone-dependent splice variant and RUSH-1β (95 kDa) is the oestrogen-dependent splice variant. Rabbit RUSH/SMARCA3 mRNA is primarily regulated at the proximal promoter (−162/+90) via a PRE (progesterone-response element) half-site/overlapping Y-box domain (−38/−26) and two Sp (specificity protein) 3 sites centred at −128 and −58. We investigated hormone regulation by exploring binding of transcription factors to a putative RUSH/SMARCA3 site (−616/−611) and the distal Sp3 (−131/−126) site. In response to progesterone, RUSH-1α binds the RUSH site and the Sp3 site becomes a functional binding site for Egr-1 (early growth-response gene product 1)/Sp (specificity protein)1/3/MAZ (Myc-associated zinc-finger protein)/MZF1 (myeloid zinc finger 1)/c-Rel. TransSignal TF–TF Interaction Arrays, supershift assays and ChIP (chromatin immunoprecipitation) analyses confirmed strong physical interactions between RUSH and Egr-1/c-Rel. Higher-order long-range interactions between RUSH and the Egr-1/c-Rel derivative of the anisotropic flexibility of the intervening DNA sequence were shown with 3C (chromosome conformation capture) assays. Transient transfection assays with mutant constructs showed the co-operative interaction between RUSH and Egr-1 mediates repression by c-Rel. Thus DNA-bound RUSH/SMARCA3 communicates with its own proximal promoter by looping the intervening DNA. Moreover, progesterone-dependent DNA looping is an adjunct to progesterone induction of the RUSH/SMARCA3 gene because the availability of RUSH isoforms and relevant binding partners is progesterone-regulated.
The Role of the SLP in Autism Spectrum Disorder Screening and Assessment
Authors: Philofsky Amy
Published: July 2008

Recent prevalence estimates for autism have been alarming as a function of the notable increase. Speech-language pathologists play a critical role in screening, assessment and intervention for children with autism. This article reviews signs that may be indicative of autism at different stages of language development, and discusses the importance of several psychometric properties—sensitivity and specificity—in utilizing screening measures for children with autism. Critical components of assessment for children with autism are reviewed. This article concludes with examples of intervention targets for children with ASD at various levels of language development.
The Role of Psychology in Working With Children and Adolescents With Autism Spectrum Disorders
Authors: Smith C. Milani
Published: July 2008

Varied disciplines participate in both the evaluation and treatment of children with autism spectrum disorder. This article reviews the role of the psychologist on an interdisciplinary team. Specific components of the assessment process are summarized, and key diagnostic tools are presented. In addition, the psychologist’s role in the assessment of language, and how this is differentiated from the contributions of the SLP, is discussed. This article concludes with a discussion of the role of the psychologist in providing intervention for children with ASD.
Investigating Novel Interventions for ASD: On Swimming With Dolphins
Authors: Hewitt Lynne
Published: July 2008

Evidence-based practice seems daunting for many busy clinicians; in fact, true critical reviews are time-intensive and costly. Yet, we are bombarded daily with intervention ideas, and for no disorder do the novel ideas come so frequently as for autism spectrum disorders. In this brief example, use of ordinary Internet resources was employed to investigate a popular, if unusual, treatment for ASD: dolphin therapy. The exercise demonstrates that judicious use of free resources can provide helpful clinical guidance.
Passy-Muir Speaking Valve Use in a Children's Hospital: An Interdisciplinary Approach
Authors: Hofmann Lauren , Bolton Joseph , Ferry Susan
Published: July 2008

At The Children's Hospital of Philadelphia (CHOP) we treat many children requiring tracheostomy tube placement. With potential for a tracheostomy tube to be in place for an extended period of time, these children may be at risk for long-term disruption to normal speech development. As such, speaking valves that restore more normal phonation are often key tools in the effort to restore speech and promote more typical language development in this population. However, successful use of speaking valves is frequently more challenging with infant and pediatric patients than with adult patients. The purpose of this article is to review background information related to speaking valves, the indications for one-way valve use, criteria for candidacy, and the benefits of using speaking valves in the pediatric population. This review will emphasize the importance of interdisciplinary collaboration from the perspectives of speech-language pathology and respiratory therapy. Along with the background information, we will present current practices and a case study to illustrate a safe and systematic approach to speaking valve implementation based upon our experiences.
Signature Currents: A Patch-Clamp Method for Determining the Selectivity of Ion-Channel Blockers in Isolated Cardiac Myocytes
Authors: Spencer C. Ian , Uchida Wataru , Turner Larry , Kozlowski Roland Z.
Published: July 2008

Background: We describe a simple method using membrane potential ramps for rapidly determining the ion-channel selectivity of drugs that affect action-potential duration in iso lated cardiac myocytes. The method allows the simultaneous assay of compounds on a number of ionic currents in a single cardiac cell.

Methods: Trains of membrane potential ramps were applied from -90 to +70 mV at 0.33 Hz to obtain a consistent "signature current," in which the major individual currents involved in the cardiac action potential could be easily identified. Confirmatory experiments were per formed using known inhibitors of these currents.

Results: The identities of the currents in the signature were established by varying the concentrations of extracellular cations and by adding known ion channel blockers to super- fusion solutions. Inhibition of each current had a characteristic and reproducible effect on the overall signature current.

Conclusions: The consistent current signature in the presence and absence of blockers sug gests that this method could be used for tertiary electrophysiological evaluation of com pounds, eg, in a drug discovery program focusing on antiarrhythmic agents. The ability to assay for secondary effects of novel compounds against multiple currents in the target cell type is convenient and avoids the artefacts associated with using artificial expression systems.
The role of coherent vorticity in turbulent transport in resistive drift-wave turbulence
Authors: Bos W. J. T. , Futatani S. , Benkadda S. , Farge M. , Schneider K.
Published: July 2008

The coherent vortex extraction method, a wavelet technique for extracting coherent vortices out of turbulent flows, is applied to simulations of resistive drift-wave turbulence in magnetized plasma (Hasegawa–Wakatani system). The aim is to retain only the essential degrees of freedom, responsible for the transport. It is shown that the radial density flux is carried by these coherent modes. In the quasi-hydrodynamic regime, coherent vortices exhibit depletion of the polarization-drift nonlinearity and vorticity strongly dominates strain, in contrast to the quasiadiabatic regime.
Effect of Joule heating on orientation of spheroidal particle in alternating electric field
Authors: Dolinsky Yu. , Elperin T.
Published: July 2008

We study the change of orientation of a spheroidal particle immersed into a liquid or gaseous host medium under the action of the alternating external electric field. It is assumed that the particle and the host medium have different electric conductivities. We show that the rate of Joule heating of the particle depends on the orientation of its axis of symmetry with respect to the direction of the electric field. If electric conductivity of particle strongly varies with temperature, the Joule heating of the particle affects orientation dynamics and results in the appearance of the new equilibrium orientations. We investigate the dependence of the dynamics of particle rotation and the direction of the equilibrium orientation on the frequency of the electric field.
Nonlinear electric field tuning characteristics of yttrium iron garnet–lead zirconate titanate microwave resonators
Authors: Fetisov Y. K. , Srinivasan G.
Published: July 2008

This report is on hysteresis and switching associated with electric field (E) tuning of ferromagnetic resonance in a bilayer of yttrium iron garnet (YIG)-lead zirconate titanate (PZT). The tuning is facilitated by piezoelectricity of PZT and mechanical bonding with YIG. For E<2kV∕cm, the frequency shift δf is linear with E. For E<10kV∕cm a pronounced hysteresis is seen in δf versus E. For E>10kV∕cm, a butterflylike dependence of δf with an abrupt switch in the sign and magnitude of δf are measured. The observations are attributed to nonlinearities of the piezoelectric deformation.
Are Technology Institutes a Satisfactory Tool for Public Intervention in the Area of Technology? A Neoclassical and Evolutionary Evaluation
Authors: Barge-Gil Andrés , Modrego-Rico Aurelia
Published: July 2008

Many public efforts have been made to foster the creation and development of organisations aimed at encouraging innovativeness in firms (and especially in small and medium-sized enterprises). In Spain, technology institutes (TIs) have been a key tool in this respect and it is necessary to evaluate whether their performance is meeting the objectives of technology policy postulated by both neoclassical and evolutionary authors. We create a set of specific indicators designed to accomplish this empirical task. Our results suggest that TIs are helping to reduce market failures in the area of technology and to foster relationships among innovation-system actors. Wide regional disparities can be explained by the different roles played by regional governments.
Plasticity of the Association between Visual Space and Action Space in a Blind-Walking Task
Authors: Ellard Colin G , Wagar Lori S
Published: July 2008

Many experiments have shown that a brief visual preview provides sufficient information to complete certain kinds of movements (reaching, grasping, and walking) with high precision. This suggests that participants must possess a calibration between visual target location and the kinaesthetic, proprioceptive, and/or vestibular stimulation generated during movement towards the target. We investigated the properties of this calibration using a cue-conflict paradigm in which participants were trained with mismatched locomotor and visual input. After training, participants were presented with visual targets and were asked to either walk to them or locate them in a spatial updating task. Our results showed that the training was sufficient to produce significant, systematic miscalibrations of the association between visual space and action space. These findings suggest that the association between action space and visual space is modifiable by experience. This plasticity could be either due to modification of a simple, task-specific sensory motor association or it could reflect a change in the gain of a path integration signal or a reorganisation of the relationship between perceived space and action space. We suggest further experiments that might help to distinguish between these possibilities.
Uncomfortable Images in Art and Nature
Authors: Fernandez Dominic , Wilkins Arnold J
Published: July 2008

The ratings of discomfort from a wide variety of images can be predicted from the energy at different spatial scales in the image, as measured by the Fourier amplitude spectrum of the luminance. Whereas comfortable images show the regression of Fourier amplitude against spatial frequency common in natural scenes, uncomfortable images show a regression with disproportionately greater amplitude at spatial frequencies within two octaves of 3 cycles deg−1. In six studies, the amplitude in this spatial frequency range relative to that elsewhere in the spectrum explains variance in judgments of discomfort from art, from images constructed from filtered noise, and from art in which the phase or amplitude spectra have been altered. Striped patterns with spatial frequency within the above range are known to be uncomfortable and capable of provoking headaches and seizures in susceptible persons. The present findings show for the first time that, even in more complex images, the energy in this spatial-frequency range is associated with aversion. We propose a simple measurement that can predict aversion to those works of art that have reached the national media because of negative public reaction.
Harnessing Vision for Computation
Authors: Changizi Mark
Published: July 2008

Might it be possible to harness the visual system to carry out artificial computations, somewhat akin to how DNA has been harnessed to carry out computation? I provide the beginnings of a research programme attempting to do this. In particular, new techniques are described for building ‘visual circuits’ (or ‘visual software’) using wire, NOT, OR, and AND gates in a visual modality such that our visual system acts as ‘visual hardware’ computing the circuit, and generating a resultant perception which is the output.
Synthesis and Structure - Property Relationships of Symmetric Ambipolar Quaterfluorene-Containing Oxadiazole as a Central Core and Diphenylamine as End-capping Moieties
Authors: Yang Fan , Zhang Xiao Ling , Xiong Mo Jun , Cao Zi Jian , Xia Ping Fang , Li Zhong Hui
Published: July 2008

A facile approach for the synthesis of the symmetric ambipolar quaterfluorene, OF(4)OX-NPh, with hole-transporting and electron-transporting moieties by Suzuki cross-coupling as a key reaction has been developed. This novel ambipolar quaterfluorene exhibits high thermal and electrochemical stabilities and is expected to possess potential application as a double charge-transfer and light-emitting material in the field of single-layer organic emitting diodes.
Synthesis and Cannabinoid Activity of a Variety of 2,3-Substituted 1-Benzo[b]thiophen Derivatives and 2,3-Substituted Benzofuran: Novel Agonists for the CB1 Receptor
Authors: Moloney Gerard P. , Angus James A. , Robertson Alan D. , Stoermer Martin J. , Robinson Michael , Lay Lucy , Wright Christine E. , McRae Ken , Christopoulos Arthur
Published: July 2008

An exploratory chemical effort has been undertaken to develop a novel series of compounds as selective CB1 agonists. It is hoped that compounds of this type will have clinical utility in pain control and cerebral ischaemia following stroke or traumatic head injury. We report here medicinal chemistry studies directed towards the investigation of several classes of 1-benzo[b]thiophen and benzofuran derivatives as novel CB1 agonists. We have discovered a novel series of compounds, which contain a 1-benzo[b]thiophen or a benzofuran group as the central aromatic group. Our investigation of this series of compounds has enhanced our understanding of the importance of binding sites within the CB1 receptor for favourable CB1 potency. Our understanding of these factors allowed us to modify the structure of a 1-benzothiophen derivative and improve its potency at the CB1 receptor.
Uncatalyzed Synthesis of β-Enamino Ketones in PEG - Water
Authors: Bandgar Babasaheb P. , Patil Sachin A. , Korbad Balaji L. , Bandgar Sunita B. , Hote Baliram S.
Published: July 2008

β-Enamino ketones have been synthesized in excellent yield by the reaction of aromatic or aliphatic amines with 1,3-dicarbonyl compounds in polyethylene glycol (PEG)-600–water. The PEG-600 is recycled and reused.
Synthesis and Biological Evaluation of Some Enantiomerically Pure C8c - C15 Monoseco Analogues of the Phenanthroquinolizidine-Type Alkaloids Cryptopleurine and Julandine
Authors: Sydnes Magne O. , Bezos Anna , Burns Christopher , Kruszelnicki Irma , Parish Christopher R. , Su Stephen , Rae A. David , Willis Anthony C. , Banwell Martin G.
Published: July 2008

A series of enantiomerically pure C8c–C15 monoseco analogues, 23–30, of the alkaloids cryptopleurine (1) and julandine (2) have been prepared using cinnamyl chloride 37 and (S)- or (R)-2-methylpiperidine as key building blocks. Two related compounds, 31 and 32, have also been synthesized. Each of these analogues has been subjected to various biological evaluations and most of them show dramatically reduced cytotoxicity compared with parent system 1. Nevertheless, they are potent anti-angiogenic agents. The formation and single-crystal X-ray analysis of the spirocyclic dienone 54, a by-product arising from attempts to prepare analogue 32, is also described.
Two isozymes of particulate methane monooxygenase with different methane oxidation kinetics are found in
Methylocystis
sp. strain SC2
Authors: Baani Mohamed , Liesack Werner
Published: July 2008

Methane-oxidizing bacteria (methanotrophs) attenuate methane emission from major sources, such as wetlands, rice paddies, and landfills, and constitute the only biological sink for atmospheric methane in upland soils. Their key enzyme is particulate methane monooxygenase (pMMO), which converts methane to methanol. It has long been believed that methane at the trace atmospheric mixing ratio of 1.75 parts per million by volume (ppmv) is not oxidized by the methanotrophs cultured to date, but rather only by some uncultured methanotrophs, and that type I and type II methanotrophs contain a single type of pMMO. Here, we show that the type II methanotroph
Methylocystis
sp. strain SC2 possesses two pMMO isozymes with different methane oxidation kinetics. The
pmoCAB1
genes encoding the known type of pMMO (pMMO1) are expressed and pMMO1 oxidizes methane only at mixing ratios >600 ppmv. The
pmoCAB2
genes encoding pMMO2, in contrast, are constitutively expressed, and pMMO2 oxidizes methane at lower mixing ratios, even at the trace level of atmospheric methane. Wild-type strain SC2 and mutants expressing
pmoCAB2
but defective in
pmoCAB1
consumed atmospheric methane for >3 months. Growth occurred at 10–100 ppmv methane. Most type II but no type I methanotrophs possess the
pmoCAB2
genes. The apparent
K
m
of pMMO2 (0.11 μM) in strain SC2 corresponds well with the
K
m(app)
values for methane oxidation measured in soils that consume atmospheric methane, thereby explaining why these soils are dominated by type II methanotrophs, and some by
Methylocystis
spp., in particular. These findings change our concept of methanotroph ecology.
Hidden copy number variation in the HapMap population
Authors: Marioni John C. , White Michael , Tavaré Simon , Lynch Andrew G.
Published: July 2008

Recently, the extent of copy number variation (CNV) throughout the genome has been shown to be far greater than previously thought. Further, it has been demonstrated that specific copy number variable regions (CNVRs) are associated with particular diseases, suggesting that these genetic variations may have an important biological role. Hence, calling CNVRs and subsequently classifying samples as “losses” or “gains” is of great interest. A number of papers have been published containing classifications of CNVs, and here we show how the presence of pedigree information can be used for assessing the performance of those classification methods. In this article, by examining CNV classifications made in the HapMap samples, we show that estimates of the number of false-positive classifications per individual made by current approaches can be determined. Moreover, commonplace technologies for determining the locations of CNVRs aggregate information across the maternal and paternal chromosomes at the locus of interest. Here, we show that copy number variation on each chromosome can be inferred and, in particular, we discuss the existence of a class of CNVs that are inevitably misclassified and give an estimate of their prevalence. Although our focus is not on the development of calling algorithms
per se
, we describe and provide an example of how our model might be incorporated into the initial classification procedure to produce more robust results. Finally, we discuss how this methodology might be applied to future studies to obtain better estimates of the extent of CNV across the genome.
Genomic expression profiling of TNF-α-treated BDC2.5 diabetogenic CD4+T cells
Authors: Lee Li-Fen , Lih Chih-Jian , Huang Chao-Jen , Cao Thai , Cohen Stanley N. , McDevitt Hugh O.
Published: July 2008

TNF-α plays an important role in immune regulation, inflammation, and autoimmunity. Chronic TNF exposure has been shown to down-modulate T cell responses. In a mouse T cell hybridoma model, TNF attenuated T cell receptor (TCR) signaling. We have confirmed that chronic TNF and anti-TNF exposure suppressed and increased T cell responses, respectively. In adult TCR (BDC2.5) transgenic nonobese diabetic mice, DNA microarray analysis of global gene expression in BDC2.5 CD4+T cells in response to chronic TNF or anti-TNF exposure showed that genes involved in functional categories including T cell signaling, cell cycle, proliferation, ubiquitination, cytokine synthesis, calcium signaling, and apoptosis were modulated. Genes such as ubiquitin family genes, cytokine inducible Src homology 2-containing genes, cyclin-dependent kinase inhibitors p21, p57, calmodulin family genes (calmodulin-1, -2, and -3) and calcium channel voltage-dependent, N type α1B subunit (CaV2.2) were induced by TNF, whereas Vav2, Rho GTPase-activating protein, calcium channel voltage-dependent, L type α1C subunit (CaV1.2), IL-1 receptor-associated kinase-1 and -2, and IL enhancer binding factor 3 were reduced by TNF. Genes such as CaV1.2 and proliferating cell nuclear antigen, repressed by TNF, were induced by anti-TNF treatment. Further, we showed that chronic TNF exposure impaired NF-κB and adaptor protein 1 transactivation activity, leading to T cell unresponsiveness. Thus, our results present a detailed picture of transcriptional programs affected by chronic TNF exposure and provide candidate target genes that may function to mediate TNF-induced T cell unresponsiveness.
Kinetics of amorphous silica dissolution and the paradox of the silica polymorphs
Authors: Dove Patricia M. , Han Nizhou , Wallace Adam F. , De Yoreo James J.
Published: July 2008

The mechanisms by which amorphous silica dissolves have proven elusive because noncrystalline materials lack the structural order that allows them to be studied by the classical terrace, ledge, kink-based models applied to crystals. This would seem to imply amorphous phases have surfaces that are disordered at an atomic scale so that the transfer of SiO
4
tetrahedra to solution always leaves the surface free energy of the solid unchanged. As a consequence, dissolution rates of amorphous phases should simply scale linearly with increasing driving force (undersaturation) through the higher probability of detaching silica tetrahedra. By examining rate measurements for two amorphous SiO
2
glasses we find, instead, a paradox. In electrolyte solutions, these silicas show the same exponential dependence on driving force as their crystalline counterpart, quartz. We analyze this enigma by considering that amorphous silicas present two predominant types of surface-coordinated silica tetrahedra to solution. Electrolytes overcome the energy barrier to nucleated detachment of higher coordinated species to create a periphery of reactive, lesser coordinated groups that increase surface energy. The result is a plausible mechanism-based model that is formally identical with the classical polynuclear theory developed for crystal growth. The model also accounts for reported demineralization rates of natural biogenic and synthetic colloidal silicas. In principle, these insights should be applicable to materials with a wide variety of compositions and structural order when the reacting units are defined by the energies of their constituent species.
CXCR4–CCR5: A couple modulating T cell functions
Authors: Contento Rita Lucia , Molon Barbara , Boularan Cedric , Pozzan Tullio , Manes Santos , Marullo Stefano , Viola Antonella
Published: July 2008

Chemokines and their receptors direct leukocyte migration among blood, lymph and tissues. Evidence has recently accumulated that, besides their chemotactic functions, chemokine receptors are highly versatile players that fine tune immune responses. During human T cell activation by antigen-presenting cells, the chemokine receptors CCR5 and CXCR4 are recruited into the immunological synapse, where they deliver costimulatory signals. However, the molecular mechanisms allowing signaling versatility of chemokine receptors are unknown. Here, we describe the functional interaction between CXCR4 and CCR5 to exert specific biological functions and modulate T lymphocyte responses. We demonstrate that simultaneous expression and cooperation between CCR5 and CXCR4 are required for chemokine-induced T cell costimulation at the immunological synapse. In addition, we provide evidence for a physical association of the two receptors in a signaling complex that activates distinct T cell functions. We suggest that cooperation between receptors represents one key strategy for the functional plasticity of chemokines.
Replication stalling at unstable inverted repeats: Interplay between DNA hairpins and fork stabilizing proteins
Authors: Voineagu Irina , Narayanan Vidhya , Lobachev Kirill S. , Mirkin Sergei M.
Published: July 2008

DNA inverted repeats (IRs) are hotspots of genomic instability in both prokaryotes and eukaryotes. This feature is commonly attributed to their ability to fold into hairpin- or cruciform-like DNA structures interfering with DNA replication and other genetic processes. However, direct evidence that IRs are replication stall sites
in vivo
is currently lacking. Here, we show by 2D electrophoretic analysis of replication intermediates that replication forks stall at IRs in bacteria, yeast, and mammalian cells. We found that DNA hairpins, rather than DNA cruciforms, are responsible for the replication stalling by comparing the effects of specifically designed imperfect IRs with varying lengths of their central spacer. Finally, we report that yeast fork-stabilizing proteins, Tof1 and Mrc1, are required to counteract repeat-mediated replication stalling. We show that the function of the Tof1 protein at DNA structure-mediated stall sites is different from its previously described effect on protein-mediated replication fork barriers.