bluuebunny/crossref_metadata_2025 huggingface dataset:
Decreased Muscle Acetyl‐Coenzyme A Carboxylase 2 mRNA and Insulin Resistance in Formerly Obese Subjects
Authors: Rosa Giuseppina , Manco Melania , Vega Natalie , Greco Aldo V. , Castagneto Marco , Vidal Hubert , Mingrone Geltrude
Published: April 2008

Objective:A relationship between free fatty acids, intramuscular triglycerides (TGMs), and insulin resistance is widely accepted. The intracellular level of malonyl‐coenzyme A (CoA) was suggested to be the possible link. Acetyl‐CoA carboxylase (ACC) is a key enzyme in fatty acid metabolism, catalyzing the synthesis of malonyl‐CoA, a fatty acid acyl‐chain elongation unit, from acetyl‐CoA. We assessed ACC2 mRNA expression variations in skeletal muscle of subjects who have undergone biliopancreatic diversion (BPD) operation. BPD, in fact inducing a massive lipid malabsorption, leads to a reversion of insulin resistance.

Research Methods and Procedures: Twelve obese women (BMI > 40 kg/m2) were enrolled in the study. Body composition, euglycemic‐hyperinsulinemic clamp, and muscle biopsies for lipid analysis and reverse transcription‐competitive polymerase chain reaction were performed before and 3 years after BPD.

Results: The average weight loss was around 37%. A significant inverse linear relation was observed between glucose uptake and TGM (y = −5.62x − 142.82, R2 = 0.50, p = 0.01). The reduced amount of ACC2 mRNA directly correlated with both TGM (y = 2.11x +69.85, R2 = 0.70, p = 0.01) and fasting insulin (y = 1.49x + 57.17, R2 = 0.69, p < 0.01) concentrations.

Discussion: In conclusion, down‐regulation of ACC2 mRNA, induced by the lowering of plasma insulin concentration, is related to improvement of insulin sensitivity. We hypothesize that reduced amount of malonyl‐CoA, consequent to reduced ACC2 mRNA, enhancing fatty acid oxidation, causes lowering of the intramyocitic triglyceride depot.
Relationship of Adiposity to Subclinical Atherosclerosis in Obese Patients with Type 2 Diabetes
Authors: Hegazi Refaat A.F. , Sutton‐Tyrrell Kim , Evans Robert W. , Kuller Lewis H. , Belle Steven , Yamamoto Monica , Edmundowicz Daniel , Kelley David E.
Published: April 2008

Objective: There is an increased prevalence of macrovascular disease in type 2 diabetes. The pathogenesis has been related to metabolic risk factors, insulin resistance, and obesity. One of the strongest predictors is the presence of subclinical atherosclerosis. This study was designed to examine the relationship between obesity and regional patterns of adiposity, insulin resistance, and five independent measures of subclinical atherosclerosis.

Research Methods and Procedures: Fifty‐two overweight and obese men and women with type 2 diabetes of relatively short known duration were examined. Measures of subclinical vascular disease were assessment of arterial stiffness by pulse wave velocity, ultrasound measurement of the carotid artery intimal‐medial thickness and plaque index, and measurement of the extent of coronary and aortic calcification using electron beam computed tomography. Insulin resistance was measured using the hyperinsulinemic euglycemic clamp. Body composition was measured using DXA and computed tomography.

Results: Adiposity was a strong determinant of pulse wave velocity. Carotid intimal‐medial thickness was correlated with age, low‐density lipoprotein‐cholesterol, and hyperglycemia, but not with adiposity. Hyperglycemia and plasma activator inhibitor‐1 were significant correlates of the carotid artery plaque index. Coronary calcium scores were significantly correlated with age and interleukin‐6 and significantly and negatively correlated to insulin sensitivity index.

Discussion: These findings suggest that obesity may play an important role in the early phase of subclinical macrovascular disease related to vessel stiffness, whereas hyperglycemia and insulin resistance in conjunction with other risk factors have important roles in progression from vessel stiffness to atheroma formation in type 2 diabetes.
Effects of Growth Hormone Administration in Human Obesity
Authors: Shadid Samyah , Jensen Michael D.
Published: April 2008

Objective: To summarize the reports in the literature regarding the effect of growth hormone (GH) treatment of obesity.

Research Methods and Procedures: Clinical trials of GH treatment of obese adults were reviewed and summarized. Specifically, information regarding the effects of GH on body fat and body fat distribution, glucose tolerance/insulin resistance, and adverse consequences of treatment were recorded.

Results: GH administered together with hypocaloric diets did not enhance fat loss or preserve lean tissue mass. No studies provided strong evidence for an independent beneficial effect of GH on visceral adiposity. In all but one study, glucose tolerance during GH treatment suffered relative to placebo.

Conclusion: The bulk of studies indicate little or no beneficial effects of GH treatment of obesity despite the low serum GH concentrations associated with obesity.
Site‐Specific Changes in the Expression of Fat‐Partitioning Genes in Weanling Rats Exposed to a Low‐Protein Diet in Utero
Authors: Maloney Chris A. , Gosby Alison K. , Phuyal Jenny L. , Denyer Gareth S. , Bryson Janet M. , Caterson Ian D.
Published: April 2008

Objective: Intrauterine growth restriction is associated with increased prevalence of the metabolic syndrome in adult life, including increased adiposity. The aim of this study was to investigate if maternal protein energy malnutrition is associated with changes in expression of genes involved in fat partitioning in weanling rats.

Research Methods and Procedures: Time‐mated mothers were placed on one of two isocaloric diets, low protein [(LP), 8% protein] or control (20% protein). All mothers remained on the diet throughout pregnancy and lactation. A third group received control for 2 weeks and was switched to LP for the last week of pregnancy and lactation [late low protein (LLP) group]. Offspring were analyzed at weaning for serum glucose, nonesterified fatty acids, triglyceride, and insulin. Expression of the genes acetyl‐coenzyme A carboxylase, fatty acid synthase, and carnitine palmitoyl transferase 1 were measured in liver, quadriceps muscle, and subcutaneous white adipose tissue using semiquantitative reverse transcription‐polymerase chain reaction.

Results: LLP and LP offspring were shorter, weighed less, had reduced serum insulin and nonesterified fatty acids, and had increased serum glucose, serum triglycerides, and hepatic triglycerides. Hepatic gene expression of acetyl‐coenzyme A carboxylase and fatty acid synthase was increased 2‐fold in LLP and LP offspring (p < 0.001). These changes were not seen in muscle or subcutaneous white adipose tissue. CPT‐1 gene expression was unaltered in all tissues examined.

Discussion: Maternal protein energy malnutrition programs gene expression of lipogenic enzymes in the liver of weanling offspring in a manner favoring fat synthesis that may predispose these offspring to fat accumulation and insulin resistance later in life.
Metabolic Adaptations to Dexamethasone‐Induced Insulin Resistance in Healthy Volunteers
Authors: Nicod Nathalie , Giusti Vittorio , Besse Christine , Tappy Luc
Published: April 2008

Objective: Insulin resistance is observed in individuals with normal glucose tolerance. This indicates that increased insulin secretion can compensate for insulin resistance and that additional defects are involved in impaired glucose tolerance or type 2 diabetes. The objective of this study was to evaluate a procedure aimed at assessing the compensatory mechanisms to insulin resistance.

Research Methods and Procedures: Eight healthy nonobese female patients were studied on two occasions, before and after administration of 2 mg/d dexamethasone for 2 days during a two‐step hyperglycemic clamp. Insulin secretion was assessed from plasma insulin concentrations. Insulin sensitivity was assessed from the ratio of whole‐body glucose use (6, 6 2H2 glucose) to plasma insulin concentrations. This procedure is known to induce a reversible impairment of glucose tolerance and insulin resistance.

Results: In all subjects, dexamethasone induced a decrease in insulin sensitivity and a proportionate increase in first‐phase insulin secretion and in insulin concentrations at both steps of glycemia. The resulting hyperinsulinemia allowed the restoration of normal whole‐body glucose uptake and the suppression of plasma free fatty acids and triglycerides. In contrast, the suppression of endogenous glucose production was impaired after dexamethasone (p < 0.01).

Discussion: Increased insulin secretion fully compensates dexamethasone‐induced insulin resistance in skeletal muscle and adipose tissue but not in the liver. This suggests that failure to overcome hepatic insulin resistance can impair glucose tolerance. The compensatory insulin secretion in response to insulin resistance can be assessed by means of a hyperglycemic clamp after a dexamethasone challenge.
Effect of Gastric Banding on Aminoterminal Pro‐brain Natriuretic Peptide in the Morbidly Obese
Authors: Hanusch‐Enserer Ursula , Hermann Katharina Maria , Cauza Edmund , Spak Marita , Mähr Bruno , Dunky Attila , Rosen Harald R. , Köller Ursula , Prager Rudolf
Published: April 2008

Objective: Aminoterminal pro‐brain natriuretic peptide (NT‐proBNP), like brain natriuretic peptide, might have diagnostic utility in detecting left ventricular hypertrophy and/or left ventricular dysfunction. The aim of the study was to investigate the relationship between morbid obesity and NT‐proBNP and the effect of weight reduction on this parameter.

Research Methods and Procedures: A total of 34 morbidly obese patients underwent laparoscopic adjustable gastric banding (LAGB). NT‐proBNP levels were measured before and 12 months after the surgery.

Results: Metabolic features and systolic and diastolic blood pressure were significantly decreased (p < 0.00001 for both) after a cumulative weight loss of 19.55 kg 1 year after LAGB. NT‐proBNP concentration was significantly higher in morbidly obese patients before LAGB than in normal‐weight control subjects (341.15 ± 127.78 fmol/mL vs. 161.68 ± 75.78 fmol/mL; p < 0.00001). After bariatric surgery, NT‐proBNP concentration decreased significantly from 341.15 ± 127.78 fmol/mL to 204.87 ± 59.84 fmol/mL (p < 0.00, 001) and remained statistically significantly elevated (204.88 ± 59.84 fmol/mL vs. 161.68 ± 75.78 fmol/mL; p = 0.04) compared with normal‐weight subjects.

Discussion: This investigation demonstrates higher levels of NT‐proBNP in morbidly obese subjects and a significant decrease during weight loss after laparoscopic adjustable gastric banding. In obesity, NT‐proBNP might be useful as a routine screening method for identifying left ventricular hypertrophy and/or left ventricular dysfunction.
Preparation and in vitro analysis of microencapsulated live Lactobacillus fermentum 11976 for augmentation of feruloyl esterase in the gastrointestinal tract
Authors: Bhathena Jasmine , Kulamarva Arun , Martoni Christopher , Urbanska Aleksandra Malgorzata , Prakash Satya
Published: April 2008

FA (ferulic acid) is a well‐known phenolic phytochemical present in plant cell walls. Various studies have indicated that FA has many physiological functions in the prevention of chronic disease. It has been shown to play an important chemoprotective role in degenerative diseases. FA also shows strong antioxidant and nitrite‐scavenging potential and anticarcinogenic and antiinflammatory properties. The in vivo physiological importance of FA depends on its availability for absorption. Dietary fibre‐bound FA is partially released by gut micro‐organisms; however, the concentration of the released FA is too low to act as a chemopreventive agent. Therefore it is important to augment the bioavailability of FA to appreciate more fully its real physiological effect. This paper evaluates the suitability of the alginate–poly(l‐lysine)–alginate microcapsules for oral delivery of live feruloyl esterase‐producing Lactobacillus fermentum 11976 cells, in vitro, by using a dynamic simulated human GI (gastrointestinal) model. The present study shows that microencapsulated L. fermentum 11976 cells can efficiently break down a FA‐containing substrate, and establishes the biotechnological basis for their use in supplementing the bioavailability of dietary FA in the intestine.
Increased biomass yield of Lactococcus lactis during energetically limited growth and respiratory conditions
Authors: Koebmann Brian , Blank Lars Mathias , Solem Christian , Petranovic Dina , Nielsen Lars K. , Jensen Peter Ruhdal
Published: April 2008

Lactococcus lactis is known to be capable of respiration under aerobic conditions in the presence of haemin. In the present study the effect of respiration on ATP production during growth on different sugars was examined. With glucose as the sole carbon source, respiratory conditions in L. lactis MG1363 resulted in only a minor increase, 21%, in biomass yield. Since ATP production through substrate‐level phosphorylation was essentially identical with and without respiration, the increased biomass yield was a result of energy‐saving under respiratory conditions estimated to be 0.4 mol of ATP/mol of glucose. With maltose as the energy source, the increase in biomass yield amounted to 51% compared with an aerobic culture that lacked haemin. This higher ATP yield was obtained by redirecting pyruvate metabolism from lactate to acetate production, and from savings through respiration. However, even after subtracting these contributions, approx. 0.3 mol of ATP/mol of glucose remained unaccounted for. A similar response to respiratory conditions (0.2 mol of ATP/mol of glucose) was observed in a mutant that had a decreased glucose uptake rate during growth on glucose caused by disruption of the PTSmannose (glucose/mannose‐specific phosphotransferase system). Amino acid catabolism could be excluded as the source of the additional ATP. Since mutants without a functional H+‐ATPase produced less ATP under sugar starvation and respiratory conditions, the additional ATP yield appears to come partly from energy saved on proton pumping through the H+‐ATPase due to respiration and partly from a reversed function of the H+‐ATPase towards oxidative phosphorylation. These results may contribute to the design and implementation of carbon‐efficient high‐cell‐density cultures of this industrially important species of bacterium.
Ethical Issues in Providing Services in Schools to Children With Swallowing and Feeding Disorders
Authors: Huffman Nancy P. , Owre DeAnne W.
Published: April 2008

Purpose

This article is a commentary and discussion of ethical issues in dysphagia services as related to school-based practice in speech-language pathology.

Method

A review of the literature on ethical issues in the provision of speech-language pathology services to individuals with dysphagia was conducted, with particular emphasis on students receiving school-based services.

Results

Issues in dysphagia management that were identified in the literature review are discussed from the perspective of biomedical ethics, professional ethics, and professional practice issues pertinent to the school setting.

Conclusion

Considerations, suggestions, and resources for ethically responsive action on the part of the school-based speech-language pathologist are provided.
Training and Self-Reported Confidence for Dysphagia Management Among Speech-Language Pathologists in the Schools
Authors: O’Donoghue Cynthia R. , Dean-Claytor Ashli
Published: April 2008

Purpose

The number of children requiring dysphagia management in the schools is increasing. This article reports survey findings relative to speech-language pathologists' (SLPs') training and self-rated confidence to treat children with swallowing and feeding disorders in the schools.

Method

Surveys were completed by 222 SLPs representing Virginia and its contiguous states. Queries on dysphagia training targeted formal education, on-the-job experiences, and current caseload information. In addition, participants self-rated their confidence to treat dysphagia.

Results

Statistically significant relationships between training and self-confidence levels were demonstrated. Specifically, participation in continuing education and currency of educational activities revealed significant and moderately strong correlations to self-reported confidence to treat children with dysphagia in the school setting.

Conclusion

Findings support continuing education as a correlate to self-reported confidence to treat dysphagia in the school setting among SLPs in Virginia and its contiguous states. Further research is merited to ascertain if these findings reflect national trends. Quantifiable, cost-effective, and evidenced-based dysphagia training, consultancy, and management models are needed if school-based SLPs are to meet the increasing challenges of their diverse caseloads.
Family Perceptions of Facilitators and Inhibitors of Effective School-Based Dysphagia Management
Authors: Angell Maureen E. , Bailey Rita L. , Stoner Julia B.
Published: April 2008

Purpose

This qualitative study focused on the perceptions of family members of children with dysphagia by asking what the family-identified factors are that facilitate or inhibit effective school-based management of pediatric dysphagia.

Method

Semistructured interviews of 7 family members of 6 children with dysphagia, ages 2 through 11 years, were conducted. Collective case study and cross-case analyses were conducted. The findings were confirmed through triangulation, respondent validation, and member checking.

Results

Interviewees identified 5 facilitating factors that enhance school-based dysphagia programs: (a) setting, (b) therapist and/or program, (c) capitalizing on positive child characteristics, (d) home–school interactions, and (e) external supports. Four factors that inhibit effectiveness also emerged: (a) setting, (b) therapist and/or program, (c) limiting child characteristics, and (d) home–school interactions.

Conclusion

Practitioners may consider addressing the factors that were identified as facilitators of effective programs. More research is needed concerning (a) factors promoting effective parent–professional relationships, (b) methods for increasing professional preparation in pediatric dysphagia, and (c) the efficacy of school-based pediatric dysphagia management programs.
Managing Dysphagia in the Schools
Authors: McNeilly Lemmietta G. , Sheppard Justine J.
Published: April 2008

Purpose

This epilogue summarizes the contribution of the articles in the clinical forum, “Managing Dysphagia in the Schools” and discusses future trends in pediatric dysphagia and the need for clinical practice and research.

Method

The contribution of each of the 10 articles that make up the forum is summarized briefly.

Conclusion

This clinical forum provides a discussion of numerous issues that need to be considered by clinicians working with children who exhibit swallowing and feeding problems and their families in school settings. Current and future challenges exist for clinicians, children, and families dealing with dysphagia. Discussion of current issues and strategies for successful treatment outcomes are provided.
Dielectric tensor of tetracene single crystals: The effect of anisotropy on polarized absorption and emission spectra
Authors: Tavazzi S. , Raimondo L. , Silvestri L. , Spearman P. , Camposeo A. , Polo M. , Pisignano D.
Published: April 2008

The full UV-visible dielectric tensor and the corresponding directions of the principal axes of triclinic tetracene crystals are reported as deduced either by polarized absorption and ellipsometry measurements or by calculations based on the molecular and crystallographic data. The results allow the attribution of the polarized bands observed in both absorption and photoluminescence emission spectra. In particular, the spectral line shape and polarization of the emission are found to depend on the sample thickness, and the effect is attributed to the modification of the state of polarization of the emitted light during its propagation inside the crystal. Indeed, the directions of polarization of the lowest optical transitions and the directions of the principal axes of the dielectric tensor are demonstrated not to coincide, in contrast to the assumptions typically made in the literature, thus causing the mixed transverse/longitudinal character of light propagation.
Instabilities and pattern miniaturization in confined and free elastic-viscous bilayers
Authors: Bandyopadhyay Dipankar , Sharma Ashutosh , Shankar V.
Published: April 2008

We present an analysis of the instabilities engendered by van der Waals forces in bilayer systems composed of a soft elastic film (<10μm) and a thin (<100nm) viscous liquid film. We consider two configurations of such systems: (a) Confined bilayers, where the bilayer is sandwiched between two rigid substrates, and (b) free bilayers, where the viscous film is sandwiched between a rigid substrate and the elastic film. Linear stability analysis shows that the time and length scales of the instabilities can be tuned over a very wide range by changing the film thickness and the material properties such as shear modulus, surface tension, and viscosity. In particular, very short wavelengths comparable to the film thickness can be obtained in bilayers, which is in contrast to the instability wavelengths in single viscous and elastic films. It is also shown that the instabilities at the interfaces of the free bilayers are initiated via an in-phase “bending” mode rather than out-of-phase “squeezing” mode. The amplitudes of deformations at both the elastic-air and elastic-viscous interfaces become more similar as the elastic film thickness decreases and its modulus increases. These findings may have potential applications in the self-organized patterning of soft materials.
Magnetoresistance in NiOx nanoconstrictions controlled by magnetic fields and currents
Authors: Céspedes O. , Viret M. , Coey J. M. D.
Published: April 2008

Ni O x nanoconstrictions 20–40nm wide on SiO2∕Si substrates exhibit nonlinear and asymmetric I-V characteristics, which are greatly affected by applied magnetic or electric fields. This behavior is attributed to the generation of magnetic conducting paths in magnetically frustrated nonstoichiometric NiOx material. The room-temperature resistance can be changed by factors of several hundreds. This property, if well controlled, is potentially very attractive for spintronic devices.
Effects of chain architectures on the surface structures of conjugated rod-coil block copolymer brushes
Authors: Li Chun-Shian , Wu Wen-Chung , Sheng Yu-Jane , Chen Wen-Chang
Published: April 2008

Rod-coil block copolymers are of unique and interesting characteristics since their physical properties can be reversibly tuned in response to the external stimuli, such as change in solvent quality. In this study, dissipative particle dynamics is used to investigate the surface structures of rod-coil polymer brushes tethered onto a surface. When immersed in the selective solvent for the coil blocks, rod blocks tend to form aggregates. Our results show that linear and Y-shaped polymer brushes exhibit similar aggregative behavior. However, some of the surface structures can be acquired within experimentally attainable surface grafting density only for Y-shaped polymer brushes. On the other hand, comblike polymer brushes are found to possess more diverse aggregative manners than linear brushes. Surface structures with aggregates taking the forms of cones, cylinders, or layers of spheres are found. By controlling the aggregative structures, it is possible for us to adjust the physical properties, such as optical function, of the material.
Strong work-hardening effect in a multiphase ZrCuAlNiO alloy
Authors: Qiu Feng , Shen Ping , Jiang Zhonghao , Liu Tao , Jiang Qichuan
Published: April 2008

A bulk as-cast ZrCuAlNiO alloy consisting of Zr2Cu, B2-type ZrCu, and a small quantity of ZrCu martensite phase was prepared by copper mold casting. The multiphase alloy exhibits a remarkable work-hardening effect (Δσy=1196MPa, ΔE=5.6GPa, and Δεe=2.11%) in the cycle loading-unloading compression test and possesses the high work-hardening capacity (Hc) of 1.66 and 1.58 at strain rates of 1×10−4 and 1×10−3s−1, respectively, under continuous deformation. The strong work-hardening effect of the alloy results from the continuous transformation of the ZrCu (B2, austenite) phase into the ZrCu martensite.
Magnetic texturing of ferromagnetic thin films by sputtering induced ripple formation
Authors: Zhang K. , Uhrmacher M. , Hofsäss H. , Krauser J.
Published: April 2008

Ripple patterns created by sputter erosion of iron thin films induce a correlated magnetic texture of the surface near region. We investigated the magnetic anisotropy as a function of the residual film thickness and determined the thickness of the magnetically anisotropic layer as well as the magnitude of the magnetic anisotropy using by magneto-optical Kerr effect (MOKE) and Rutherford backscattering spectroscopy measurements. Ripple patterns were created by sputter erosion with 5keV Xe ions under grazing incidence of 80° with respect to the surface normal. For ion fluences of above 1×1016cm−2, the formation of ripples, with wavelengths between 30 and 80nm oriented parallel to the ion beam direction, is observed. MOKE measurements reveal a pronounced uniaxial magnetic anisotropy of the surface region of the films with orientation parallel to the ripple orientation and the ion beam direction. We find a layer thickness of 12±3nm, in accordance with the average grain size. The magnetic anisotropy within this layer varies from about 25% for thick residual films toward 100% for films with less than 30nm thickness. The magnitude of the magnetic anisotropy is determined by the shape anisotropy of the rippled surface as well as the interface roughness. We have demonstrated that sputter erosion yields highly anisotropic magnetic thin films and can be used to fabricate nanorods and nanowires with pronounced uniaxial magnetic anisotropy.
Improved dielectric and ferromagnetic properties in Fe-doped PbTiO3 nanoparticles at room temperature
Authors: Verma K. C. , Kotnala R. K. , Negi N. S.
Published: April 2008

Fe-doped PbTiO3 nanoparticles have been synthesized by chemical route using polyvinyl alcohol as a surfactant. The results indicate that the dielectric constant and magnetization value of these nanoparticles depends upon their size and Fe dopents. The x-ray diffraction analysis, and transmission and scanning electron microscopies show that the particle’s sizes in the specimens lie in the range of 19–30nm. It is observed that the magnetization is enhanced with reduction in particle size. The largest value of saturation magnetization (Ms=41.6×10−3emu∕g) is observed for 1.2mol% Fe dopents. Dielectric constant and dielectric losses are controlled up to 15MHz at room temperature.
Thermodynamical and structural properties of imidazolium based ionic liquids from molecular simulation
Authors: Raabe Gabriele , Köhler Jürgen
Published: April 2008

We have performed molecular dynamics simulations to determine the densities and heat of vaporization as well as structural information for the 1-alkyl-3-methyl-imidazolium based ionic liquids [amim][Cl] and [amim][BF4] in the temperature range from 298to363K. In this simulation study, we used an united atom model of Liu et al. [Phys. Chem. Chem. Phys. 8, 1096 (2006)] for the [emim+] and [bmim+] cations, which we have extended for simulation in [hmim]-ILs and combined with parameters of Canongia Lopes et al. [J. Phys. Chem. B 108, 2038 (2004)] for the [Cl−] anion. Our simulation results prove that both the original united atoms approach by Liu et al. and our extension yield reasonable predictions for the ionic liquid with a considerably reduced computational expense than that required for all atoms models. Radial distribution functions and spatial distribution functions where employed to analyze the local structure of this ionic liquid, and in which way it is influenced by the type of the anion, the size of the cation, and the temperature. Our simulations give evidence for the occurrence of tail aggregations in these ionic liquids with increasing length of the side chain and also increasing temperature.
Rapid qualitative phase analysis in highly textured thin films by x-ray diffraction
Authors: Borgia Cesare , Olliges Sven , Spolenak Ralph
Published: April 2008

Phase analysis of highly out-of-plane textured specimens using x-ray diffraction is usually complicated due to the disappearance of most of the x-ray peaks in a common θ∕2θ diffraction geometry. In this paper, we propose a technique, where powderlike spectra of textured samples are obtained by multiaxial x-ray diffraction scans. This technique is a simple, yet powerful method which allows for significant improvement in thin film characterization and provides several types of information about the samples, such as the rapid qualitative identification of phases using common powder x-ray diffraction spectra databases, texture distribution, and quantitative residual stress analysis.
Laser-produced energetic electron transport in overdense plasmas by wire guiding
Authors: Zhou C. T. , He X. T. , Yu M. Y.
Published: April 2008

Laser-driven energetic electron transport in a two-layered (Au and DT) ultrahigh density plasma is investigated. It is shown that the jump in the resistivity at the interface of the two plasmas plays an important role in the slowing down of the energetic beam electrons and heating of the plasmas. Furthermore, a thin gold wire in the DT plasma can further slow down the beam electrons and absorb a part of the beam energy.
Generation of nitrogen acceptors in ZnO using pulse thermal processing
Authors: Xu Jun , Ott Ronald , Sabau Adrian S. , Pan Zhengwei , Xiu Faxian , Liu Jianlin , Erie Jean-Marie , Norton David P.
Published: April 2008

Bipolar doping in wide bandgap semiconductors is difficult to achieve under equilibrium conditions because of the spontaneous formation of compensating defects and unfavorable energetics for dopant substitution. In this work, we explored the use of rapid pulse thermal processing for activating nitrogen dopants into acceptor states in ZnO. Low-temperature photoluminescence spectra revealed both acceptor-bound exciton (AX0) and donor-acceptor pair emissions, which present direct evidence for acceptors generated after pulse thermal processing of nitrogen-doped ZnO. This work suggests that pulse thermal processing is potentially an effective method for p-type doping of ZnO.
Nonequilibrium and effect of gas mixtures in an atmospheric microplasma
Authors: Mariotti Davide
Published: April 2008

The gas and effective electron temperatures have been estimated for atmospheric microplasma by means of optical emission spectroscopy. The results have shown that the microplasma exhibits nonequilibrium and, as its size is reduced, the two temperatures depart from each other, enhancing the nonequilibrium characteristic. The effect of methane and oxygen concentrations has also been studied, showing that gas mixtures have an important effect on the microplasma state.
Bipolar space charge formation and switching effect in thin polymer films
Authors: Nikitenko V. R. , Tameev A. R. , Vannikov A. V. , Lachinov A. N. , Bässler H.
Published: April 2008

A theoretical model of bipolar charge formation in a polymer film is proposed. High density of metastable charge pairs within a thin trapping layer results from their delayed recombination. The conditions for the highest density of charge pairs are discussed. The formation of conductive channels by charge pairs starting from the trapping layer together with the high mobility of “Coulomb holes” in the channels can switch the structure to the highly conductive state.
High-resolution two-dimensional quantitative analysis of phosphorus, vanadium and arsenic, and qualitative analysis of sulfide, in a freshwater sediment
Authors: Stockdale Anthony , Davison William , Zhang Hao
Published: April 2008

Environmental context. Chemical characterisation of sediment microniches can reveal diagenetic processes that may not be detected by larger-scale analysis. With the development of a new preparation method for a binding phase gel, the technique of diffusive gradients in thin films has been used to demonstrate links between the diagenesis of sulfide, phosphorus, vanadium and arsenic at microniches. Knowledge of these processes may improve predictions of past deposition climates where trace elements are considered as paleoredox proxies.
Abstract. Recently introduced techniques that can provide two-dimensional images of solution concentrations in sediments for multiple analytes have revealed discrete sites of geochemical behaviour different from the average for that depth (microniches). We have developed a new preparation method for a binding phase, incorporated in a hydrogel, for the diffusive gradients in thin films (DGT) technique. It allows co-analysis of sulfide and the reactive forms of phosphorus, vanadium and arsenic in the porewaters at the surface of the device. This gel, when dried and analysed using laser ablation mass spectrometry, allows the acquisition of high-resolution sub-millimetre-scale data. The binding phase was deployed within a DGT device in a sediment core collected from a productive lake, Esthwaite Water (UK). Localised removal of phosphate and vanadium from the porewaters has been demonstrated at a microniche of local sulfide production. The possible removal processes, including bacterial uptake and reduction of vanadate to insoluble VIII by sulfide, are discussed. Understanding processes occurring at this scale may allow improved prediction of pollutant fate and better prediction of past climates where trace metals are used as paleoredox proxies.
Methylmercury in arctic Alaskan mosquitoes: implications for impact of atmospheric mercury depletion events
Authors: Hammerschmidt Chad R. , Fitzgerald William F.
Published: April 2008

Environmental context. Recent research suggests that gross mercury deposition in the Arctic is increased significantly as a result of springtime Atmospheric Mercury Depletion Events (AMDE). A primary environmental and human health concern is whether mercury deposited with these events leads to enhanced production and uptake of the toxic methylmercury species in polar ecosystems. Here, we present an initial assessment of potential impact from AMDE utilising mosquitoes as bioindicators of methylmercury accumulation in freshwater and terrestrial food webs within 200 km of the Arctic Ocean.
Abstract. Atmospheric Mercury Depletion Events (AMDE) – phenomena in which elemental Hg is oxidised and stripped from the atmosphere over an 8–12-week period following polar sunrise – appear to increase Hg deposition to environs near the Arctic Ocean with a lesser impact inland. A key concern is whether such events lead to enhanced production and uptake of the toxic methylmercury (MeHg) species into arctic food webs. Here, we used mosquitoes, which are sensitive and site-specific bioindicators of Hg loadings, to assess the impact of AMDE on ecosystem MeHg contamination along a 200-km transect between the Arctic Ocean coast and foothills of the Brooks Range, where gross atmospheric Hg deposition appears to be ~20-fold less than that near the coast. This preliminary survey revealed little variation and no gradient in mosquito MeHg levels, which suggests comparable ecosystem impact. This may also point to significant cycling and reemission (e.g. via photoreduction) of Hg deposited during AMDE from the snow and ice pack to the atmosphere.
What do we know about forest fire size distribution, and why is this knowledge useful for forest management?
Authors: Cui Wenbin , Perera Ajith H.
Published: April 2008

Forest fire size distribution (FSD) is one of the suite of indicators of forest fire regimes. It is applied in forest fire management, particularly for planning and evaluating suppression efforts. It is also used in forest management in the context of emulating natural fire disturbances. Given the recent growth in research and applied interest in this topic, we review and synthesise the state of knowledge on FSD, and identify sources of knowledge uncertainties and future research directions. Based on literature, it is common for forest fires to follow the power law probability distribution, particularly the truncated subtype, under a variety of forest types and forest and fire management practices. Other types of FSD are also observed, but under specific circumstances. Although there is evidence that observed FSDs vary both over space and time, the knowledge is too fragmented to generalise the cause–effect relationships for such variation. As well, it is not clear how the various methods of studying FSD and their spatio-temporal scales influence derivations of FSDs. We suggest that a hypothetico-deductive research approach, combining empirical studies with process-based simulations is an effective means to advance the knowledge of FSD. We suggest caution in the use of FSD in forest management because applying different distributions or even different parameters for the same distribution may result in great fire size class differences and thus different implications for forest management.
Different interest group views of fuels treatments: survey results from fire and fire surrogate treatments in a Sierran mixed conifer forest, California, USA
Authors: McCaffrey Sarah , Moghaddas Jason J. , Stephens Scott L.
Published: April 2008

The present paper discusses results from a survey about the acceptance of and preferences for fuels treatments of participants following a field tour of the University of California Blodgett Forest Fire and Fire Surrogate Study Site. Although original expectations were that tours would be composed of general members of the public, individual tour groups ultimately were much more specialised, with tours made up of individuals from five distinct groups including foresters, environmentalists, entomologists, the Natural Resource Conservation Service, teachers, and high school or undergraduate students. This proved fortuitous as most studies of ‘public’ perceptions to date have been of general members of the public and little work has been done assessing the views of groups who may have more specific knowledge or interest in fuels treatments. Such assessment is perhaps long overdue given the importance of understanding characteristics of different audience segments in developing effective outreach programs. Analysis showed that group membership was in fact the key element in differences in survey responses with significant differences found between groups on overall acceptability of treatments, treatment preferences based on different land ownership and management types, and which variables were most important in determining treatment preferences.
Effective chromosome pairing requires chromatin remodeling at the onset of meiosis
Authors: Colas Isabelle , Shaw Peter , Prieto Pilar , Wanous Michael , Spielmeyer Wolfgang , Mago Rohit , Moore Graham
Published: April 2008

During meiosis, homologous chromosomes (homologues) recognize each other and then intimately associate. Studies exploiting species with large chromosomes reveal that chromatin is remodeled at the onset of meiosis before this intimate association. However, little is known about the effect the remodeling has on pairing. We show here in wheat that chromatin remodeling of homologues can only occur if they are identical or nearly identical. Moreover, a failure to undergo remodeling results in reduced pairing between the homologues. Thus, chromatin remodeling at the onset of meiosis enables the chromosomes to become competent to pair and recombine efficiently.
ADOWA AND THE HISTORIOGRAPHY OF ITALIAN COLONIALISM
Authors: Finaldi Giuseppe
Published: April 2008

Report on the Convegno internazionale di studi nel centenario della battaglia di Adua, Piacenza, 10–12 April 1996, now published as, Angeld Del Boca (ed.), Adua. Le ragioni di una sconfitta, Laterza, Rome - Bari, 1997, 468 pp., ISBN 88–420–5196–9, 45,000 Lire.

In April 1987, I turned up at Trento's Centro Santa Chiara expecting to see a screening of Mustapha Akkad's The Lion of the Desert and discovered instead, due to a forced entry into the auditorium and confiscation of the reels by the Digos, that Italy faced its colonial past with real anxiety. This film recounts the life of Omar al-Mukhtar, the man who made Italy's conquest of Libya a vicious and bloody war of attrition complete with the whole set up that empirebuilding required for its cheerful accomplishment: concentration camps, mass deportations, massacres of civilians, carpet bombing of villages, etc. Omar al-Mukhtar was hanged, of course, and for Gheddafi Libyan patriotism was born, hence his pleasure in pouring enough oil money into the film to attract big names like Anthony Quinn and Irene Papas. But in Italy the film was banned because considered ‘damaging to the army's honour’. It is strange, but perhaps not altogether without logic, that the Italian army should feel threatened by people being able to see soldiers of Fascist Italy behaving as the soldiers of Fascist Italy behaved, when taking into consideration that the Italian Republic was born, like Libya, out of the Resistance. As in Germany (or so goes the story), the army remained impervious to the excesses of fascist ideology and, of course, played an important part in countering it. But if there was a project that the Italian army (before and during Fascism) made very much its own it was the colonization of Africa.
The sacred synthesis: the ideological cohesion of Fascist cultural policy
Authors: Griffin Roger
Published: April 2008

This article challenges commonly held preconceptions about the absence of a cohesive cultural policy by arguing that, while many rival aesthetic creeds were accommodated under Mussolini's regime, they can all be seen as permutations of a common vision of the central role to be played by a culture in the regeneration of the national community and the creation of a new Italy. It points to a profound relationship between Fascism's cultural policy and its core mobilizing myth of palingenetic ultra-nationalism, which similarly spawned a wide variety of surface ideologies similarly doomed to failure by the irreducibly pluralistic nature of modern society.
Investigating the Influence of Continuous Babble on Auditory Short-Term Memory Performance
Authors: Heinrich Antje , Schneider Bruce A. , Craik Fergus I. M.
Published: April 2008

A number of factors could explain the adverse effect that babble noise has on memory for spoken words (Murphy, Craik, Li, & Schneider, 2000). Babble could degrade the perceptual representation of words to such an extent that it compromises their subsequent processing, or the presence of speech noise in the period between word presentations could interfere with rehearsal. Thirdly, the top-down processes needed to extract the words from the babble could draw on resources that otherwise would be used for encoding. We tested all these hypotheses by presenting babble either only during word presentation or rehearsal, or by gating the babble on and off 500 ms before and after each word pair. Only the last condition led to a decline in memory. We propose that this decline in memory occurred because participants were focusing their attention on the auditory stream (to enable them to better segregate the words from the noise background) rather than on remembering the words they had heard. To further support our claim we show that a similar memory deficit results when participants perform the same memory task in quiet together with a nonauditory attention-demanding secondary task.
A Mixed Rasch Model of Dual-Process Conditional Reasoning
Authors: Bonnefon Jean-François , Eid Michael , Vautier Stéphane , Jmel Saïd
Published: April 2008

A fine-grained dual-process approach to conditional reasoning is advocated: Responses to conditional syllogisms are reached through the operation of either one of two systems, each of which can rely on two different mechanisms. System1 relies either on pragmatic implicatures or on the retrieval of information from semantic memory; System2 operates first through inhibition of System1, then (but not always) through activation of analytical processes. It follows that reasoners will fall into one of four groups of increasing reasoning ability, each group being uniquely characterized by (a) the modal pattern of individual answers to blocks of affirming the consequent (AC), denying the antecedent (DA), and modus tollens (MT) syllogisms featuring the same conditional; and (b) the average rate of determinate answers to AC, DA, and MT. This account receives indirect support from the extant literature and direct support from a mixed Rasch model of responses given to 18 syllogisms by 486 adult reasoners.
A Comparison of Backward and Forward Spatial Spans
Authors: Cornoldi Cesare , Mammarella Irene C.
Published: April 2008

The standard Corsi blocks task is frequently used to measure the capacity of visuospatial working memory, but the implications of the use of both forward and backward recall are still unclear. In the present study, we showed that the backward Corsi task is particularly powerful in discriminating between low- and high-spatial-ability individuals and involves different processes from those involved in the forward task. From a sample of 425 participants we selected one group of 20 high-spatial-ability participants and one of 20 low-spatial-ability participants. The results demonstrated that a backward spatial span offers specific information not available from a forward spatial span, and that there was no facilitation due to a descending format. In particular, in the low-spatial-ability group, performance was generally poorer, but backward Corsi recall was lower than forward recall, and participants did not show any advantage following the descending presentation format—which in some contexts is considered to reduce proactive interference. We conclude that the backward Corsi task has specific value and that the assumption of fully parallel verbal and visuospatial working-memory systems can lead to a variety of misunderstandings.
Accurate approximation method for prediction of class I MHC affinities for peptides of length 8, 10 and 11 using prediction tools trained on 9mers
Authors: Lundegaard Claus , Lund Ole , Nielsen Morten
Published: April 2008

Summary: Several accurate prediction systems have been developed for prediction of class I major histocompatibility complex (MHC):peptide binding. Most of these are trained on binding affinity data of primarily 9mer peptides. Here, we show how prediction methods trained on 9mer data can be used for accurate binding affinity prediction of peptides of length 8, 10 and 11. The method gives the opportunity to predict peptides with a different length than nine for MHC alleles where no such peptides have been measured. As validation, the performance of this approach is compared to predictors trained on peptides of the peptide length in question. In this validation, the approximation method has an accuracy that is comparable to or better than methods trained on a peptide length identical to the predicted peptides.

Availablility: The algorithm has been implemented in the web-accessible servers NetMHC-3.0: http://www.cbs.dtu.dk/services/NetMHC-3.0, and NetMHCpan-1.1: http://www.cbs.dtu.dk/services/NetMHCpan-1.1

Contact:  lunde@cbs.dtu.dk

Supplementary information:  Supplementary data are available at Bioinformatics online