bluuebunny/crossref_metadata_2025 huggingface dataset:
Étude comparative des habiletés requises pour effectuer l’intégration scolaire des enfants en difficulté
Authors: Brunet Luc , Goupil Georgette
Published: July 2012

La réussite des politiques d’intégration des enfants en difficulté d’adaptation et d’apprentissage exige de la part des maîtres en exercice de posséder certaines habiletés spécifiques et de la part des directions d’école une perception positive de ces habiletés chez leurs enseignants. Les résultats de cette recherche démontrent que les maîtres en exercice ne se perçoivent que moyennement habilités pour procéder à l’intégration des enfants en difficulté. Les résultats obtenus indiquent également que les directions d’école ont une perception un peu négative des habiletés de leurs enseignants pour mener à bien un tel projet.
La distance sociale inter-ethnique dans le milieu scolaire
Authors: Beauchesne André , Limoges Jacques , Paul Denise
Published: July 2012

La qualité de l’interaction entre les différentes ethnies d’une école multiculturelle dépend en grande partie de la distance sociale qu’elles entretiennent les unes vis-à-vis des autres. Cette relation devient particulièrement problématique quand des élèves immigrants d’une minorité ethno-culturelle tentent de s’intégrer à la culture dominante. Les résultats de recherche exposés dans cet article démontrent combien l’attitude d’acceptation des membres des deux ethnies de l’échantillon tend à s’opposer. Les élèves de la majorité culturelle maintiennent une grande distance sociale pendant que ceux de la minorité expriment un accueil évident.
Coal Liquefaction
Authors: Kaneko Takao , Derbyshire Frank , Makino Eiichiro , Gray David , Tamura Masaaki , Li Kejian
Published: July 2012

The article contains sections titled:1.Introduction1.1.Commercial Development1.2.Historical Background2.Indirect Coal Liquefaction2.1.Preparation of Synthesis Gas2.1.1.Coal Gasification2.1.2.Water–Gas Shift2.1.3.Synthesis Gas Purification2.2.Fischer–Tropsch Synthesis2.2.1.Mechanisms2.2.2.Product Selectivity and Characteristics2.2.3.Catalytic Selectivity2.2.4.Refining of Crude Products2.2.5.Integrated Plant Configurations2.2.6.Commercial Practice at SASOL2.2.7.New and Developing Technologies2.2.8.Advanced Systems2.3.Methanol and Methanol to Gasoline (MTG)2.4.Dimethyl Ether (DME)2.5.Environmental Protection2.6.Economic Aspects3.Direct Coal Liquefaction3.1.Mechanisms3.2.Liquefaction Products3.3.Solvents3.3.1.Hydrogen Donors3.3.2.Coal Conversion and Hydrogen Transfer3.3.3.Interactive Solvent Effects3.3.4.Side Reactions of Solvents3.4.Coal Composition3.4.1.Coal Rank3.4.2.Bituminous Coal3.4.3.Low‐Rank Coal3.4.4.Coal Drying and Oxidation3.5.Gaseous Hydrogen3.6.Liquefaction in COH2O and COH2H2O3.7.Catalysis3.7.1.Mechanisms3.7.2.Disposable Catalysts3.7.3.Supported Catalysts3.7.4.Molten Halide Catalysts3.8.Process Description3.9.Commercial Processes3.9.1.Kohleoel (Ruhrkohle‐Veba Oel) Process3.9.2.NEDOL Process3.9.3.Solvent‐Refined Coal (SRC‐I and SRC‐II) Processes3.9.4.Exxon Donor Solvent Process3.9.5.H‐Coal Process3.9.6.Catalytic Two‐Stage Process3.9.7.HTI Coal Process3.9.8.BCL Process3.9.9.Liquefaction Solvent Extraction Process3.10.Environmental Considerations3.11.Economic Aspects
Hard Materials
Authors: Zerr Andreas , Eschnauer Heinz , Kny Erich
Published: July 2012

The article contains sections titled:1.Introduction1.1.Hardness Measurement (Overview)1.2.Classification of Hard Materials1.2.1.Occurrence1.2.2.Appearance1.2.3.Electrical Conductivity1.2.4.Composition and Thermal Stability in Air2.Nonmetallic Hard Materials2.1.Diamond2.2.Cubic Boron Nitride (c‐BN)2.3.Silicon Nitrides2.4.Transition Metal Nitrides MxNx+12.5.Silicon Carbide2.6.Alumina2.7.Cermets3.Metallic Hard Materials (Cemented Carbides)3.1.Production3.1.1.Raw Materials3.1.2.Powder Batch Manufacturing3.1.3.Pressing and Forming3.1.4.Sintering3.1.5.Machining3.1.6.Coating3.1.7.Testing and Quality Control3.2.Commercial Grades3.3.Properties3.4.Uses3.5.Economic Aspects3.6.Toxicology

Hard materials are solid substances exhibiting a high resistance towards plastic (irreversible) deformation or damage of their surface by scratching (Mohs or Martens scale), grinding (Rosiwal method) or indentation (Brinell, Rockwell, Shore, Vickers, or Knoop testing). Some of them occur in nature but the majority is synthetic. They are also classified according to their appearance, electric conductivity, and chemical composition which defines their thermal stability in air. This article gives an overview of the synthesis routes, properties, and fields of application of the most important nonmetallic and metallic hard materials. A few recently discovered hard compounds are briefly introduced. Finally, the family of cemented carbides is discussed in more detail, which is broadly used today for cutting of ferrous alloys, in forming equipment, mining industry, and wear resistant components.
Metallic Glasses
Authors: Suryanarayana Challapalli , Inoue Akihisa
Published: July 2012

The article contains sections titled:1.Introduction2.Classification of Metallic Glasses3.The Concepts of Glass Formation4.Glass‐Forming Ability4.1.Critical Cooling Rate4.2.Reduced Glass Transition Temperature4.3.Deep Eutectics4.4.Topological Models4.5.Inoue Criteria4.6.New Criteria5.Synthesis of Metallic Glasses5.1.Principles of Rapid Solidification Processing5.2.General Techniques to Achieve High Rates of Solidification5.3.Melt Spinning5.4.Bulk Metallic Glasses5.4.1.Water Quenching Method5.4.2.Copper Mold Casting5.4.3.Metallic Glass Composites5.4.4.Metallic Glass Foams5.5.Other Methods5.5.1.Mechanical Alloying5.5.2.Vapor Phase Methods6.Crystallization Behavior6.1.Crystallization Modes in Glassy Alloys6.2.Polymorphous Crystallization6.3.Eutectic Crystallization6.4.Primary Crystallization7.Physical Properties7.1.Density7.2.Thermal Expansion7.3.Diffusion7.4.Electrical Resistivity7.5.Specific Heat7.6.Viscosity8.Corrosion Behavior8.1.Effect of Alloying Additions8.2.Influence of Structural Changes9.Mechanical Properties9.1.Deformation Behavior9.1.1.Inhomogeneous Deformation9.1.2.Homogeneous Deformation9.2.Deformation Maps9.3.Temperature Rise at Shear Bands9.4.Strength9.5.Ductility9.6.Fatigue9.6.1.Fatigue Crack Growth Rate9.6.2.Improvement of Fatigue Resistance9.7.Yield Behavior9.8.BMG Composites9.8.1.Mechanical Properties of Composites9.8.2.Initiation and Propagation of Shear Bands10.Magnetic Properties10.1.Effect of Alloying Elements10.2.Effect of Annealing10.3.Nanocrystalline Alloys11.Applications11.1.Mechanical Applications11.2.Chemical Applications11.3.Electrical Applications11.4.Magnetic Applications11.5.Miscellaneous Applications11.5.1.Jewelry11.5.2.Biomedical Applications11.5.3.Other Applications
Mutagenic Agents
Authors: Pfau Wolfgang
Published: July 2012

The article contains sections titled:

1.

Introduction

2.

Mutagenesis

2.1.

Gene Mutations

2.1.1.

Point Mutations

2.1.2.

Frameshift Mutations

2.2.

Chromosomal Aberrations

2.3.

Genome Mutations

3.

DNA Repair

4.

Mutations and Cancer

5.

Mutagenicity Tests

5.1.

Microbial Tests

5.2.

Eukaryotic In Vitro Tests

5.2.1.

Mammalian Gene Mutagenicity Tests

5.2.2.

In Vitro Cytogenetic Assays

5.3.

In Vivo Tests

5.3.1.

Micronucleus Assay

5.3.2.

Germ‐Cell Tests

5.3.3.

Indicator Tests

5.3.4.

Transgenic Animals

6.

Testing Strategies

7.

Metabolic Activation

8.

Types of Mutagenic Agents

9.

Conclusions
Chiral Compounds
Authors: Blaser Hans‐Ulrich , Pfaltz Andreas , Wennemers Helma
Published: July 2012

The article contains sections titled:1.Introduction1.1.Properties of Enantiomers1.2.Absolute Configuration at Stereogenic Centers1.3.Other Stereogenic Elements2.Analysis of Chiral Compounds2.1.Optical Rotation2.2.NMR‐Spectroscopic Analysis2.3.Chromatographic Analysis3.Occurrence, Significance and Synthetic Options3.1.Occurrence and Significance3.2.Synthetic Options4.Resolution of Racemates and Chiral Pool Approach4.1.Resolution of Racemates4.2.Chiral Pool Approach5.Stoichiometric Enantioselective Synthesis5.1.Chiral Reagents5.2.Chiral Auxiliaries6.Enantioselective Catalysis7.Catalysis with Soluble Metal Complexes (Homogeneous Catalysis)7.1.Hydrogenation of Olefins, Ketones and C=N Functions7.2.Oxidation Reactions7.3.Addition Reactions to C=C, C=O, and C=N Moieties7.4.Miscellaneous Transformations7.5.Future Developments8.Heterogeneous Catalysis9.Organocatalysis9.1.Covalent Binding: Aminocatalysis9.2.Hydrogen–Bonding Catalysis9.3.Ion Pair Formation: Catalysis with Lewis Bases, Brønsted Acids, and Phase Transfer Cations9.4.Further Aspects and Future Developments10.Enzymatic Transformations
Catalytic Fixed‐Bed Reactors
Authors: Eigenberger Gerhart , Ruppel Wilhelm
Published: July 2012

The article contains sections titled:1.Fixed‐Bed Reactors with Gas‐Phase Reactions1.1.Introduction1.2.Catalyst Forms for Fixed‐Bed Reactors1.2.1.Fluid Flow, Mass and Heat Transfer, and Chemical Reaction in Catalyst‐Filled Tubes1.2.2.Regular Catalyst Structures1.2.3.Comparison and Evaluation of Different Catalyst Forms1.3.Adiabatic Fixed‐Bed Reactors1.3.1.Axial and Radial Flow Reactors1.3.2.Multistage Reactors with Interstage Heat Transfer1.4.Fixed‐Bed Reactors with Integrated Heat Exchange1.4.1.Heat‐Exchange Concepts1.4.2.Heat‐Transfer Media for Fixed‐Bed Reactors1.4.3.Cooled Reactors for Exothermic Reactions1.4.4.Heated Reactors for Endothermic Reactions1.4.5.Influencing the Course of Reaction1.5.Heat‐Integrated Reactor Concepts1.5.1.Autothermal Reactors with External and Internal Heat Exchange1.5.2.Heat‐Integrated Reactors for Coupling of Endo‐ and Exothermic Reactions1.6.Operational and Safety Issues1.6.1.Parametric Sensitivity and Runaway1.6.2.Moving Temperature and Reaction Fronts1.6.3.Other Safety Aspects1.7.Periodic Operation of Fixed‐Bed Reactors1.7.1.Fixed‐Bed Reactors with Periodic Flow Reversal and Exothermic Reaction1.7.2.Fixed‐Bed Reactors with Periodic Flow Reversal for Coupled Exo‐ and Endothermic Reactions1.7.3.Periodic Feed Cycling2.Fixed‐Bed Reactors for Liquid‐Phase Reactions2.1.Introduction2.2.Fixed‐Bed Catalyzed Liquid‐Phase Reactions2.3.Upward Liquid Flow through Fixed Beds2.4.Reactor Layout and Operation2.4.1.Safety Issues2.4.2.Example: Amination of Alcohols

Catalytic fixed‐bed reactors are the most important type of reactors for the synthesis of large‐scale basic chemicals and intermediates and for the treatment of harmful and toxic substances in the gas or the liquid phase. In these reactors the solid catalyst in the form of pellets or regular structures is arranged as a so‐called fixed bed. In this article fixed‐bed reactors with homogeneous (single‐phase) gas or liquid flow are considered. It is a revision of the first version of 1992 and an updated extension of a version published in theHandbook of HeterogeneousCatalysis[53]. Since in the vast majority of cases catalytic fixed‐bed reactors are used for gas‐phase reactions, such reactors are treated in detail in Chapter 1. In Chapter 2 the main differences and peculiarities when fixed‐bed reactors are used for liquid‐phase reactions are mentioned. Fixed‐bed reactors with multiphase gas–liquid or gas–liquid–solid flow are treated in → Three‐Phase Trickle‐Bed Reactors.
Metallic Foams
Authors: Baumeister Joachim , Weise Jörg
Published: July 2012

There are numerous processes for making metallic foams or similar highly porous metallic structures. The various processes can be classified into those starting from metallic melts, those starting from powdered metals, and those using deposition techniques. Most methods work for a specific range of metals and alloys and result in a typical foam structure with closed cells or open, interconnected cells. The most important manufacturing methods and a number of established industrial applications are presented.

The article contains sections titled:1.Introduction2.Production2.1.Production from Metallic Melts2.2.Production from Metal Powders2.3.Production by Deposition Techniques3.Toxicology and Occupational Health4.Applications and Outlook
Using Ground‐Penetrating Radar to Examine Spatial Organization at the Late Classic Maya Site of El Baúl, Cotzumalhuapa, Guatemala
Authors: Safi Kristin N. , Mazariegos Oswaldo Chinchilla , Lipo Carl P. , Neff Hector
Published: July 2012

The Cotzumalhuapa Nuclear Zone (CNZ) is a Late Classic site consisting of three large architectural compounds linked by a series of stone‐paved causeways and bridges. The majority of the site, however, lies beneath layers of recent tephra, leaving the structure of this settlement largely unknown. This study uses ground‐penetrating radar (GPR) to map the subsurface near El Baúl, one of the main compounds, in order to examine the spatial relationship among urban architectural features. Excavation within areas of the GPR survey provides fine‐grain detail of one major architectural feature in the region, the Gavarrete Causeway. The complimentary nature of these data sets characterizes the architectural organization of the settlement at two scales. Spatial patterning between large‐scale architectural features supports the hypothesis that the CNZ represents an integrated urban center with evidence of planned community organization characteristic of other Late Classic period centers across Mesoamerica.
Risk mapping of illegal poisoning of avian and mammalian predators
Authors: Márquez Carolina , Vargas J. Mario , Villafuerte Rafael , Fa John E.
Published: July 2012

Wild predators are targeted if they are perceived to affect game species or domestic animals. Over the last century, the direct persecution of birds of prey and mammalian carnivores has led to their widespread decline, even local extirpations. Many such cases involved the illegal use of poisoned bait. We used 1,305 detected poisoning events and 59 biophysical variables to construct a distribution model of illegal poisoning throughout Andalusia, southern Spain. We chose this region because the largest number of poisoning events recorded in Spain were detected in Andalusia during the period 1990–2005. Our results showed greater incidence of poisoning was correlated with areas of high predator richness and high wild rabbit hunting yields. Thus, we hypothesize that wildlife managers should be able to estimate current and potential poisoning areas using frequency of poisoning events data. Managers can then focus control within those areas identified as conflict zones and establish surveillance schemes that prevent the loss of wildlife within the targeted areas. Our results have potential application in strategic planning for conservation of vulnerable high‐profile species such as birds of prey and mammalian carnivores in southern Spain and other regions. © 2012 The Wildlife Society.
Heterobifunctional Poly(ethylene glycol) Derivatives for the Surface Modification of Gold Nanoparticles Toward Bone Mineral Targeting
Authors: Zayed Gamal M. S. , Tessmar Joerg K. V.
Published: July 2012

Heterobifunctional poly(ethylene glycol)s can be used for many biomedical applications ranging from solubility enhancement of hardly soluble compounds to surface modification of medical devices. In order to modify gold nanoparticles as model particles for drug targeting applications, PEG derivatives are synthesized that possess a high affinity for gold surfaces, namely a thioalkyl function, known to form stable monolayers on gold. Additionally a bisphosphonate function is introduced in the PEG molecule to allow targeting of hydroxyapatite rich tissues, like bone. Gold nanoparticles are modified using the synthesized bifunctional PEG and investigated for their stability in biological fluids and their ability to bind to hydroxyapatite granules in these fluids.

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Routine sperm banking for testicular cancer patients should be performed both before and after orchidectomy
Authors: Tomlinson MJ , Kohut TL , Hopkisson JF , Lemberger RJ
Published: July 2012

Background:

Despite some groups recommending that sperm banking for testicular cancer patients prior to orchidectomy results in improved overall semen quality, it remains common practice for this to occur post operatively, prior to any chemotherapy. Having seen anecdotal evidence of patients being rendered azoospermic and thus sterile by unilateral orchidectomy, we investigated further.

Methods:

Forty men listed for orchidectomy banked a single sample before surgery and were then given the opportunity to bank further samples post operatively.

Results:

Post orchidectomy, overall sperm concentration ( p = 0.01) and motility ( p < 0.05) were lower compared to before surgery and two men had azoospermia. However, the overall picture was misleading as in 13 individuals their sperm output was increased ( n = 13) after surgery. Both cases of post operative azoospermia were amongst the patients with seminoma although at least 50% of patients with teratoma had severe oligozoospermia post surgery.

Conclusions:

Despite the relatively high frequency of normal sperm counts amongst seminoma patients, there was no significant difference in total sperm output or sperm quality between these men and those with teratoma or mixed cell tumours. As overall sperm quality was lower after surgery and some patients had totally compromised fertility, our centre has changed its policy to encouraging sperm banking prior to surgery. However, we maintain that generalisation of this population is unwise and patients should also attend after surgery to optimise the quality of their samples in the sperm bank.
Screening of plant extracts for antifungal activities against Colletotrichum species of common bean (Phaseolus vulgaris L.) and cowpea (Vigna unguiculata (L.) Walp)
Authors: MASANGWA J. I. G. , AVELING T. A. S. , KRITZINGER Q.
Published: July 2012

The aim of the present investigation was to evaluate the antifungal activities of plant extracts which can be used to control bean and cowpea anthracnose. Acetone, ethyl acetate and water extracts of Ipomoea batatas, Carica papaya, Allium sativum, Syzygium cordatum, Chlorophytum comosum and Agapanthus caulescens were screened in vitro for their antifungal activities against Colletotrichum lindemuthianum and Colletotrichum dematium of common bean and cowpea using the agar disc infusion and microtitre double-dilution techniques. The same extracts were then tested for antifungal activity in vivo as seed treatments against anthracnose disease. The water extracts of Carica and Syzygium were active against C. lindemuthianum and had minimum inhibitory concentrations (MICs) of 1·56 mg/ml. Syzygium, Allium and Chlorophytum water extracts were active against C. dematium and MICs were 3·13, 6·25 and 12·5 mg/ml, respectively. The MICs of Allium, Syzygium and Agapanthus acetone extracts were 0·78, 3·13 and 6·25 mg/ml, respectively, against C. lindemuthianum and 0·78, 6·25 and 3·13 mg/ml against C. dematium. Agapanthus water extracts and all the acetone extracts tested in vivo effectively reduced the incidence and severity of bean anthracnose disease in the greenhouse. Agapanthus acetone, Allium water, and both acetone and water extracts of Carica and Syzygium performed well in vivo in reducing cowpea anthracnose disease and compared well with reductions due to the application of the synthetic fungicide fludioxonil+mefenoxam (the commercial product Celest® XL) applied at 25 gai/l and also with levels in the non-inoculated control. The Agapanthus, Carica, Syzygium and Allium extracts were active on both Colletotrichum spp. in vitro and also reduced anthracnose disease of bean and cowpea and are potential seed treatments in anthracnose disease control. The easy seed treatment process and the accessibility of plants used in the present study could lead to high adoption of the use of the plant extracts as seed treatments by resource-poor, smallholder farmers.
Contribution of the mesolimbic dopamine system in mediating the effects of leptin and ghrelin on feeding
Authors: van Zessen R. , van der Plasse G. , Adan R. A. H.
Published: July 2012

Feeding behaviour is crucial for the survival of an organism and is regulated by different brain circuits. Among these circuits the mesolimbic dopamine (DA) system is implicated in the anticipation and motivation for food rewards. This system consists of the dopaminergic neurons in the ventral tegmental area (VTA), and their projections to different cortico-limbic structures such as the nucleus accumbens and medial prefrontal cortex. While the importance of this system in motivational drive for different rewards, including drugs of abuse, has been clearly established, its role in energy balance remains largely unexplored. Evidence suggests that peripheral hormones such as leptin and ghrelin are involved in the anticipation and motivation for food and this might be partially mediated through their effects on the VTA. Yet, it remains to be determined whether these effects are direct effects of ghrelin and leptin onto VTA DA neurons, and to what extent indirect effects through other brain areas contribute. Elucidation of the role of leptin and ghrelin signalling on VTA DA neurons in relation to disruptions of energy balance might provide important insights into the role of this neural circuit in obesity and anorexia nervosa.
FREEDOM, HISTORY, AND RACE IN PROGRESSIVE THOUGHT
Authors: Miller Tiffany Jones
Published: July 2012

Scholarly discussions of the turn of the 20th century progressive movement frequently ignore or give but glancing attention to the progressives’ racial views and policies. Those who do pay greater attention to them nonetheless tend to dismiss them as being somehow “paradoxical” or inconsistent with what they regard as the movement’s core, “democratic” principles. The purpose of this paper, accordingly, is to explain the origin and nature of the movement’s core principles, and to show how the reformers’ racial views and policies, far from being inconsistent with these principles, were in fact their natural outgrowth. The progressives’ support for the colonial subjugation of the Filipinos, as well as the disfranchisement and segregation of American blacks, reflects, in other words, the transformation in the character or content of public policy necessitated by the reformers’ rejection of the “individualism” of the American founding in favor of a new conception of “individualism” chiefly inspired by early 19th century German idealism.
SAVING LOCKE FROM MARX: THE LABOR THEORY OF VALUE IN INTELLECTUAL PROPERTY THEORY
Authors: Mossoff Adam
Published: July 2012

The labor theory of value is fundamental to John Locke’s justification for property rights, but Edwin Hettinger argues in a famous article, “Justifying Intellectual Property,” that it fails to justify intellectual property rights. Hettinger believes that the labor theory of value cannot justify a right to the full economic value in an invention or book, because the creator’s physical labor contributes only proportionally to this socially-created market value. Robert Nozick, G. A. Cohen, and other philosophers similarly dismiss the labor theory of value as illogical or incoherent. But these philosophers redefine Locke’s concepts oflaborandvalueintophysicalandeconomicterms, which is more akin to Karl Marx’s labor theory of economic value. The principle of interpretative charity demands reconsideration of Locke’s labor theory of value in its own terms and within the full context of his natural law ethical theory, especially in considering how Locke himself justifies intellectual property rights. This article thus analyzes oft-neglected portions of the text of theSecond Treatiseand integrates Locke’s property theory within the context of his natural law ethical theory, as presented inAn Essay Concerning Human Understandingand in other works. In this context, Locke’s concept of labor means production, which has intellectual as well as physical characteristics, and his concept of value means that which is useful in the flourishing life of a rational being, which is a conception of the good that is more robust than merely physical status or economic wealth. This not only disabuses modern scholars of the absurdities they impose on Locke, it also explains why Locke says that inventions exemplify his labor-based property theory and why he argues for property rights in writings (copyrights), arguments that seem to have been lost on his critics in intellectual property theory and beyond.
Descriptive epidemiology of enteric disease in Chennai, India
Authors: CHOPRA R. D. , DWORKIN M. S.
Published: July 2012

There are very few data on the prevalence of coccidian enteric parasites among low-income adults hospitalized in Chennai, India. Stool samples from 200 patients were screened for selected parasites, enteric bacterial pathogens, and other protozoa over a 3-month period. The study identified 42 (21%)Cryptosporidium, 36 (18%)V. cholerae, 17 (9%)Salmonellla, 12 (6%)Isospora, six (3%) helminths, five (3%)Shigella, one (1%)Cyclospora, one (1%) other protozoan, and 0%V. parahaemolyticuscases. Co-infection was present in 21 patients.Cryptosporidiumwas detected in 17 (81%) of co-infected patients. Our findings highlighted the relatively high proportion of patients in this population withCryptosporidiumandIsosporaand suggest that further study be undertaken to determine the utility of broader use of diagnostic testing for coccidian parasites in India. Detection may be beneficial because isosporiasis is treatable and bothIsosporaandCryptosporidiumare important pathogens in AIDS patients.
Experimentally Modifying Interpretations for Positive and Negative Social Scenarios in Children: A Preliminary Investigation
Authors: Vassilopoulos Stephanos P. , Moberly Nicholas J. , Zisimatou Georgia
Published: July 2012

Background: Past research suggests that socially anxious individuals display a tendency to interpret ambiguous and clearly valenced information in a threatening way. Interpretation training programs, in which individuals are trained to endorse benign rather than negative interpretations of ambiguous social scenarios, have proven effective for reducing anxiety-related cognitive biases. However, it is not clear whether the same paradigms are effective in modifying interpretation biases for clearly valenced social information. Method: In this experiment, a group of unselected children (aged 10–13 years) was trained to endorse the more positive of two possible interpretations of mildly negative and positive social events. Results: Data revealed that this group (n = 77) showed a decrease in catastrophic interpretations and an increase in neutral interpretations of mildly negative events compared to children in a no-training control group (n = 76). Furthermore, participants in the training condition showed an increase in positive interpretations and a trend for a decrease in discounting interpretations of positive events. However, training did not affect emotional ratings of mildly negative and positive events or trait social anxiety. Conclusions: Notwithstanding certain limitations of this pilot study, we believe that the results are promising with regard to modifying interpretative biases for clearly valenced vignettes, and that further study regarding the effects of training on mood is warranted.
Investigation into longitudinal dietary behaviours and household socio-economic indicators and their association with BMIZ-score and fat mass in South African adolescents: the Birth to Twenty (Bt20) cohort
Authors: Feeley Alison B , Musenge Eustasius , Pettifor John M , Norris Shane A
Published: July 2012

Objective

The present study aimed to assess the relationship between dietary habits, change in socio-economic status and BMIZ-score and fat mass in a cohort of South African adolescents.

Design

In the longitudinal study, data were collected at ages 13, 15 and 17 years on a birth cohort who have been followed since 1990. Black participants with complete dietary habits data (breakfast consumption during the week and at weekends, snacking while watching television, eating main meal with family, lunchbox use, number of tuck shop purchases, fast-food consumption, confectionery consumption and sweetened beverage consumption) at all three ages and body composition data at age 17 years were included in the analyses. Generalized estimating equations were used to test the associations between individual longitudinal dietary habits and obesity (denoted by BMIZ-score and fat mass) with adjustments for change in socio-economic status between birth and age 12 years.

Setting

Birth to Twenty (Bt20) study, Soweto-Johannesburg, South Africa.

Subjects

Adolescents (n1298; 49·7 % male).

Results

In males, the multivariable analyses showed that soft drink consumption was positively associated with both BMIZ-score and fat mass (P< 0·05). Furthermore, these relationships remained the same after adjustment for socio-economic indicators (P< 0·05). No associations were found in females.

Conclusions

Longitudinal soft drink consumption was associated with increased BMIZ-score and fat mass in males only. Fridge ownership at birth (a proxy for greater household disposable income in this cohort) was shown to be associated with both BMIZ-score and fat mass.
HspX‐mediated protection against tuberculosis depends on its chaperoning of a mycobacterial molecule
Authors: Taylor Jennifer L , Wieczorek Agatha , Keyser Andrew R , Grover Ajay , Flinkstrom Rachel , Karls Russell K , Bielefeldt‐Ohmann Helle , Dobos Karen M , Izzo Angelo A
Published: July 2012

New approaches consisting of ‘multistage’ vaccines against (TB) are emerging that combine early antigenic proteins with latency‐associated antigens. In this study, HspX was tested for its potential to elicit both short‐ and long‐term protective immune responses. HspX is a logical component in vaccine strategies targeting protective immune responses against primary infection, as well as against reactivation of latent infection, because as previously shown, it is produced during latency, and as our studies show, it elicits protection within 30 days of infection. Recent studies have shown that the current TB vaccine, bacilli Calmette‐Guerin (BCG), does not induce strong interferon‐γ T‐cell responses to latency‐associated antigens like HspX, which may be in part why BCG fails to protect against reactivation disease. We therefore tested HspX protein alone as a prophylactic vaccine and as a boost to BCG vaccination, and found that HspX purified from M. tuberculosis cell lysates protected mice against aerosol challenge and improved the protective efficacy of BCG when used as a booster vaccine. Native HspX was highly immunogenic and protective, in a dose‐dependent manner, in both short‐ and long‐term infection models. Based on these promising findings, HspX was produced as a recombinant protein in E. coli, as this would enable facile purification; however, recombinant HspX (rHspX) alone consistently failed to protect against aerosol challenge. Incubation of rHspX with mycobacterial cell lysate and re‐purification following incubation restored the capacity of the protein to confer protection. These data suggest the possibility that the native form may chaperone an immunogenic and protective antigen that is mycobacteria‐specific.
Starfish ApDOCK protein essentially functions in larval defense system operated by mesenchyme cells
Authors: Furukawa Ryohei , Funabashi Hiromi , Matsumoto Midori , Kaneko Hiroyuki
Published: July 2012

In larvae of the starfish, Asterina pectinifera, mesenchyme cells operate in the defense system through various behaviors. We have investigated mesenchyme cell dynamics during the immune response by identifying ApDOCK, a new member of the DOCK180 superfamily protein. In 4‐day‐old bipinnaria larvae processed for morpholino oligonucleotide‐mediated knockdown of ApDOCK, injection of inorganic foreign substances revealed that (1) mesenchyme cells fail to undergo either directed migration toward a large oil‐droplet or persistent spreading on the oil‐droplet after contact; (2) neither uptake of micro‐beads nor cell‐to‐cell fusion on the large oil‐droplet differed from that of mesenchyme cells from control larvae. Similar behaviors were also recorded in experiments where bacteria were injected. Under culture conditions, the expression level of ApDOCK mRNA was significantly associated with the immunological behavior of mesenchyme cells. Apparently, the mesenchyme cells from ApDOCK loss‐of‐function larvae exhibited insufficient lamellipodium formation via lack of fibrous form of actin organization at the leading edge. These results suggest that the migratory congregation and persistence of encapsulation of larval mesenchyme cells are intracellularly regulated by ApDOCK protein, and this regulation is associated with organization of cytoskeletal actin.
Design of coupling for synchronization in time-delayed systems
Authors: Ghosh Dibakar , Grosu Ioan , Dana Syamal K.
Published: July 2012

We report a design of delay coupling for targeting desired synchronization in delay dynamical systems. We target synchronization, antisynchronization, lag-and antilag-synchronization, amplitude death (or oscillation death), and generalized synchronization in mismatched oscillators. A scaling of the size of an attractor is made possible in different synchronization regimes. We realize a type of mixed synchronization where synchronization and antisynchronization coexist in different pairs of state variables of the coupled system. We establish the stability condition of synchronization using the Krasovskii-Lyapunov function theory and the Hurwitz matrix criterion. We present numerical examples using the Mackey-Glass system and a delay Rössler system.
First results from EBW emission diagnostics on COMPASS
Authors: Zajac J. , Preinhaelter J. , Urban J. , Aftanas M. , Bílková P. , Böhm P. , Fuchs V. , Nanobashvili S. , Weinzettl V. , Žáček F.
Published: July 2012

COMPASS tokamak shots at low magnetic field feature overdense plasmas during the extended current flat-top phase. The first harmonic of the electron cyclotron emission is completely cutoff for O and X modes and so the emission caused by electron Bernstein waves (EBWs) propagating obliquely with respect to the magnetic field and undergoing so called EBW-X-O conversion process can be observed. We perform an angular scan of the EBW emission during a set of comparable shots in order to determine the optimum antenna direction. A weak dependence of the radiative temperature on the antenna angles indicates an influence of multiple reflections from the vessel wall. The low temperature at the mode conversion region is responsible for the collisional damping of EBW, which can explain several times lower measured radiative temperature than the electron temperature measured by the Thomson scattering system.
Feasibility of characterizing laser-ablated carbon plasmas via planar laser induced fluorescence
Authors: Bondarenko A. S. , Schaeffer D. B. , Everson E. T. , Constantin C. G. , Clark S. E. , Niemann C.
Published: July 2012

Planar laser induced fluorescence (PLIF) imaging can potentially assess ion distributions and coupling in the context of super-Alfvénic ablation plasma expansions into magnetized background plasmas. In this feasibility study, we consider the application of PLIF to rapidly expanding carbon plasmas generated via energetic laser ablation of graphite. By utilizing hydrodynamic and collisional-radiative simulations, we identify schemes accessible to commercially available tunable lasers for the C I atom, the C II ion, and the C V ion. We then estimate the signal-to-noise ratios yielded by the schemes under reasonable experimental configurations.
Theoretical investigation of the He–I2(E3Πg) ion-pair state: Ab initio intermolecular potential and vibrational levels
Authors: Kalemos Apostolos , Valdés Álvaro , Prosmiti Rita
Published: July 2012

We present a theoretical study on the potential energy surface and vibrational bound states of the E electronic excited state of the HeI2 van der Waals system. The interaction energies are computed using accurate ab initio methods and large basis sets. Relativistic small-core effective core potentials in conjunction with a quintuple-zeta quality basis set are employed for the heavy iodine atoms in multireference configuration interaction calculations for the 3A′ and 3A″ states. For the representation of the potential energy surface we used a general interpolation technique for constructing potential surfaces from ab initio data based on the reproducing kernel Hilbert space method. The surface presents global and local minima for T-shaped configurations with well-depths of 33.2 and 4.6 cm−1, respectively. Vibrational energies and states are computed through variational quantum mechanical calculations. We found that the binding energy of the HeI2(E) T-shaped isomer is 16.85 cm−1, in excellent agreement with recent experimental measurements. In lieu of more experimental data we also report our predictions on higher vibrational levels and we analyze the influence of the underlying surface on them. This is the first attempt to represent the potential surface of such a highly excited electronic state of a van der Waals complex, and it demonstrates the capability of the ab initio technology to provide accurate results for carrying out reliable studies to model experimental data.
Density functional theory model study of size and structure effects on water dissociation by platinum nanoparticles
Authors: Fajín José L. C. , Bruix Albert , Cordeiro Maria Natália D. S. , Gomes José R. B. , Illas Francesc
Published: July 2012

Size and structure effects on the homolytic water dissociation reaction mediated by Pt nanoparticles have been investigated through density functional theory calculations carried out on a series of cubooctahedral Ptn nanoparticles of increasing sizes (n = 13, 19, 38, 55, 79, and 140). Water adsorption energy is not significantly influenced by the nanoparticle size. However, activation energy barrier strongly depends on the particle size. In general, the activation energy barrier increases with nanoparticles size, varying from 0.30 eV for Pt19 to 0.70 eV for Pt140. For the largest particle the calculated barrier is very close to that predicted for water dissociation on Pt(111) (0.78 eV) even though the reaction mediated by the Pt nanoparticles involves adsorption sites not present on the extended surface.
On the accuracy of explicitly correlated coupled-cluster interaction energies — have orbital results been beaten yet?
Authors: Patkowski Konrad
Published: July 2012

The basis set convergence of weak interaction energies for dimers of noble gases helium through krypton is studied for six variants of the explicitly correlated, frozen geminal coupled-cluster singles, doubles, and noniterative triples [CCSD(T)-F12] approach: the CCSD(T)-F12a, CCSD(T)-F12b, and CCSD(T)(F12*) methods with scaled and unscaled triples. These dimers were chosen because CCSD(T) complete-basis-set (CBS) limit benchmarks are available for them to a particularly high precision. The dependence of interaction energies on the auxiliary basis sets has been investigated and it was found that the default resolution-of-identity sets cc-pVXZ/JKFIT are far from adequate in this case. Overall, employing the explicitly correlated approach clearly speeds up the basis set convergence of CCSD(T) interaction energies, however, quite surprisingly, the improvement is not as large as the one achieved by a simple addition of bond functions to the orbital basis set. Bond functions substantially improve the CCSD(T)-F12 interaction energies as well. For small and moderate bases with bond functions, the accuracy delivered by the CCSD(T)-F12 approach cannot be matched by conventional CCSD(T). However, the latter method in the largest available bases still delivers the CBS limit to a better precision than CCSD(T)-F12 in the largest bases available for that approach. Our calculations suggest that the primary reason for the limited accuracy of the large-basis CCSD(T)-F12 treatment are the approximations made at the CCSD-F12 level and the non-explicitly correlated treatment of triples. In contrast, the explicitly correlated second-order Møller-Plesset perturbation theory (MP2-F12) approach is able to pinpoint the complete-basis-set limit MP2 interaction energies of rare gas dimers to a better precision than conventional MP2. Finally, we report and analyze an unexpected failure of the CCSD(T)-F12 method to deliver the core-core and core-valence correlation corrections to interaction energies consistently and accurately.
Enhancement of hole injection and electroluminescence characteristics by a rubbing-induced lying orientation of alpha-sexithiophene
Authors: Matsushima Toshinori , Murata Hideyuki
Published: July 2012

The authors find that rubbing a film of alpha-sexithiophene (α-6T) with a nylon cloth induces a change from standing to lying orientations in a film surface region. While current densities of hole-only devices based on 4,4′,4″-tris(N-3-methylphenyl-N-phenyl-amino)triphenylamine (m-MTDATA) are independent of the rubbing number of α-6T, current densities of hole-only devices based on N-N′-diphenyl-N-N′-bis(1-naphthyl)-1,1′-biphenyl-4,4′-diamine (α-NPD) and 4,4′-bis(carbazol-9-yl)-2,2′-biphenyl (CBP) markedly increase (≈42 times at 1 V for the α-NPD devices and ≈236 times at 1 V for the CBP devices) as the rubbing number of α-6T is increased. The increase in current density is ascribed to enhanced hole injection through a −5.28 eV energy level of lying α-6T domains instead of a −4.95 eV energy level of standing α-6T domains and improved overlaps between an electronic cloud of indium tin oxide, π orbitals of lying α-6T molecules, and π orbitals of molecules of α-NPD and CBP at heterojunction interfaces. The rubbing of α-6T is also demonstrated to reduce drive voltages (by ≈40% at 10 mA/cm2) and increase power conversion efficiency (by ≈26% at 10 mA/cm2) of organic light-emitting diodes. Finally, half lifetimes are significantly enhanced (4.3 times) at a current density of 50 mA/cm2.
An algorithm to find minimum free-energy paths using umbrella integration
Authors: Bohner Matthias U. , Kästner Johannes
Published: July 2012

The calculation of free-energy barriers by umbrella sampling and many other methods is hampered by the necessity for an a priori choice of the reaction coordinate along which to sample. We avoid this problem by providing a method to search for saddle points on the free-energy surface in many coordinates. The necessary gradients and Hessians of the free energy are obtained by multidimensional umbrella integration. We construct the minimum free-energy path by following the gradient down to minima on the free-energy surface. The change of free energy along the path is obtained by integrating out all coordinates orthogonal to the path. While we expect the method to be applicable to large systems, we test it on the alanine dipeptide in vacuum. The minima, transition states, and free-energy barriers agree well with those obtained previously with other methods.
Multipactor saturation in parallel-plate waveguides
Authors: Sorolla E. , Mattes M.
Published: July 2012

The saturation stage of a multipactor discharge is considered of interest, since it can guide towards a criterion to assess the multipactor onset. The electron cloud under multipactor regime within a parallel-plate waveguide is modeled by a thin continuous distribution of charge and the equations of motion are calculated taking into account the space charge effects. The saturation is identified by the interaction of the electron cloud with its image charge. The stability of the electron population growth is analyzed and two mechanisms of saturation to explain the steady-state multipactor for voltages near above the threshold onset are identified. The impact energy in the collision against the metal plates decreases during the electron population growth due to the attraction of the electron sheet on the image through the initial plate. When this growth remains stable till the impact energy reaches the first cross-over point, the electron surface density tends to a constant value. When the stability is broken before reaching the first cross-over point the surface charge density oscillates chaotically bounded within a certain range. In this case, an expression to calculate the maximum electron surface charge density is found whose predictions agree with the simulations when the voltage is not too high.
Airflow influence on the discharge performance of dielectric barrier discharge plasma actuators
Authors: Kriegseis J. , Grundmann S. , Tropea C.
Published: July 2012

In the present work, the effect of the airflow on the performance of dielectric barrier discharge plasma-actuators is investigated experimentally. In order to analyze the actuator’s performance, luminosity measurements have been carried out simultaneously with the recording of the relevant electrical parameters. A performance drop of about 10% is observed for the entire measured parameter range at a flow speed of M = 0.145 (U∞=50 m/s). This insight is of particular importance, since the plasma-actuator control authority is already significantly reduced at this modest speed level. The results at higher Mach numbers (0.4<M<0.8) reveal an even more pronounced reduction of about 30%. From the combined analysis, the conclusion is drawn that the decreasing electrical performance PA correlates closely with the decreasing luminosity peak intensity Ĝ for increasing airflow velocities. Two non-dimensional scaling numbers are proposed to characterize and quantify the airflow influence. It is demonstrated that these numbers span a universal performance drop diagram for the entire range of investigated operating parameters.
Ion acoustic solitons in Earth’s upward current region
Authors: Main D. S. , Newman D. L. , Scholz C. , Ergun R. E.
Published: July 2012

The formation and evolution of ion acoustic solitons in Earth’s auroral upward current region are studied using one- and two-dimensional (2D) electrostatic particle-in-cell simulations. The one-dimensional simulations are confined to processes that occur in the auroral cavity and include four plasma populations: hot electrons, H+ and O+ anti-earthward ion beams, and a hot H+ background population. Ion acoustic solitons are found to form for auroral-cavity ion beams consistent with acceleration through double-layer (DL) potentials measured by FAST. A simplified one-dimensional model simulation is then presented in order to isolate the mechanisms that lead to the formation of the ion acoustic soliton. Results of a two-dimensional simulation, which include both the ionosphere and the auroral cavity, separated by a low-altitude DL, are then presented in order to confirm that the soliton forms in a more realistic 2D geometry. The 2D simulation is initialized with a U-shaped potential structure that mimics the inferred shape of the low altitude transition region based on observations. In this simulation, a soliton localized perpendicular to the geomagnetic field is observed to form and reside next to the DL. Finally, the 2D simulation results are compared with FAST data and it is found that certain aspects of the data can be explained by assuming the presence of an ion acoustic soliton.
Photonic band structures of one-dimensional photonic crystals doped with plasma
Authors: Guo B. , Xie M. Q. , Peng L.
Published: July 2012

The photonic band structures (PBSs) of oblique incidence propagation in one-dimensional plasma-doped photonic crystals (PCs) are investigated carefully. When the lattice constant of plasma-doped PCs is less than the incident wavelength, the PC becomes anisotropic. Therefore, the dielectric constant of PC is converted into a complex tensor dielectric constant. This determines the PBSs of PCs. In the present paper, one-dimensional PCs are taken as an example to study both normal and absorption PBSs. Using both the effective medium approximation and the transfer matrix method, we can derive the dispersion relation for PCs. The dependence of the plasma filling factor on the effective dielectric constant and PBSs is calculated and discussed.