bluuebunny/crossref_metadata_2025 huggingface dataset:
Study 1: Experimental Study of Violent Video Games With Elementary School and College Students
Authors: Anderson Craig A. , Gentile Douglas A. , Buckley Katherine E.
Published: April 2010

This chapter presents Study 1, which examined the effects of exposure to the mildest form of violent video games (cartoonish children's games) on short-term aggressive behavior by children and college students. In this experimental study, some of children and some of the college students were randomly assigned to played a children's game with violent or one without violent content. Some of the college students played a teen-rated violent game. Afterwards, all of the participants played another computer game in which they set punishment levels that they thought would be delivered to another participant. Actually, there was no other person receiving the punishments. The main finding was that playing a violent video game increased the severity of punishments that participants tried to deliver to another person by more that 40%. Even college students playing children's violent games became more aggressive. Other findings are reported concerning the effects of past media habits, parental involvement, having TVs and video games in the bedroom, and attitudes towards violence.
7 Risk Factor Illustrations
Authors: Anderson Craig A. , Gentile Douglas A. , Buckley Katherine E.
Published: April 2010

Chapter 3 described theoretically how media violence can be considered a risk factor for aggression. This chapter further explores the risk factor approach, which provides the testable hypothesis that if media violence is a risk factor, it should increase the likelihood of aggressive behavior. It should increase the risk even in the presence of other risk factors and protective factors. Data from three studies of children and adolescents were examined; all three yielded strong evidence that violent video game play increases the risk of aggressive behaviors. The children with the greatest likelihood of physical fights and other aggressive behaviors were those with multiple risk factors and no protective factor. Holding other risk and protective factors equal, violent video game exposure almost doubled the risk of children being involved in physical fights.
9 Interpretations and Public Policy
Authors: Anderson Craig A. , Gentile Douglas A. , Buckley Katherine E.
Published: April 2010

This chapter discusses the magnitude of media violence effects, the idea of media violence providing catharsis (venting) for aggression, and a host of public policy questions. It shows, for example, that the harmful effects of violent video games are at least as large as many other known risk factors, such having abusive parents. Furthermore, video game violence is important because almost all children are exposed to this risk factor. The vast array of media violence studies over the last 50 years strongly disproves the catharsis idea that (unfortunately) remains so popular in modern culture. This is the idea that using violent media allows a person to vent their pent up aggressive inclinations, thereby reducing real aggressive behavior. Although this idea is appealing, it is wrong. The chapter concludes with descriptions of a wide array of public policy options that various concerned parents, legislators, and policy makers in a number of countries have proposed to address the harmful effects of violent video games.
Changing Classroom Social Settings Through Attention to Norms
Authors: Henry David B.
Published: April 2010

Building on theories of social settings, this chapter describes the norms that develop among students in classrooms in terms of feedback circuits, and offers a theory of change based on altering the normative feedback students receive. It recommends that teachers work to establish norms early in the life of a classroom social setting; provide regular behavioral feedback that includes behavioral praise as well as correction; and make use of opportunities to make behavioral norms salient to students. Further, the chapter also proposes research on measurement of classroom norms and on interventions to change them. The measurement theory offered is based on Jackson's Return Potential Model, which sees norms as the interaction between behavior and approval in a social setting. Finally, the chapter reviews interventions that attempt to change behavior through changing norms, and evaluates the effects of such normative feedback interventions on substance abuse among college students. Using meta-analysis to estimate the mean effect size of such normative feedback interventions, it contends that the effect size compares favorably to the mean effect size found for a popular substance use preventive intervention. The chapter concludes by encouraging further development of theory and intervention about normative processes.
Quality Accountability: Improving Fidelity of Broad Developmentally Focused Interventions
Authors: Smith Charles , Akiva Tom
Published: April 2010

This chapter describes the Youth Program Quality Intervention (YPQI), a setting-level intervention model designed to raise quality in out-of-school time programs. The YPQI takes managers and staff from a network of youth programs through a process of identifying and addressing strengths and areas for improvement, using a standardized assessment tool. This tool operationalizes a definition of program quality based on providing youth access to key developmental experiences. Descriptive findings about the quality of youth programs are presented. A three-level model of settings also addresses system accountability, management, and the point of service in youth programs. The chapter discusses accountability structures ranging from low stakes to higher stakes, and presents a generic model for setting change.
Chapter 3 Limitations of Economic and Social Indicators
Authors: Diener Ed , Lucas Richard E. , Schimmack Ulrich , Helliwell John F.
Published: April 2010

Economically developed societies devote considerable resources to collecting economic and social indicators to help policy makers in their deliberations about how to best increase quality of life. These measures have had notable successes, and yet they suffer from substantial limitations. The reasons that economic and social indicators cannot reflect the full range of factors that affect quality of life are described. For example, no complete list of factors affecting quality of life can be created, and the way people weight these factors differs. Furthermore, it is often not clear which set of measures best reflects desirable states in various areas such as the economy. In the context of the economy, there is disagreement about which forms of goods and services need to be counted, for example whether housework should be part of the gross domestic product (GDP). Because of the shortcomings of economic and social indicators, additional information is required for wide policy making.
Chapter 6 Issues Regarding the Use of Well-Being Measures for Policy
Authors: Diener Ed , Lucas Richard E. , Schimmack Ulrich , Helliwell John F.
Published: April 2010

Besides concerns about measurement validity, a number of other potential problems are often believed to accompany the use of well-being measures to assist policy makers. One objection is that it is paternalistic for policy makers to be concerned with the well-being of individuals, and another concern is that people adapt to circumstances so that the objective conditions of a society are not reflected in people’s subjective evaluations of life. The underlying issue here is whether people’s well-being is so subject to comparisons—with other people, with one’s past, and with personal aspirations—that using the surveys to inform policy becomes unwise. Evidence is reviewed that certain conditions have enduring effects on well-being, and that subjective well-being is not completely relative. Thus, many of the concerns about using well-being for policy are exaggerated or unfounded.
Chapter 9 The Environment and Well-Being: Policy Examples
Authors: Diener Ed , Lucas Richard E. , Schimmack Ulrich , Helliwell John F.
Published: April 2010

One of the most pressing policy concerns in the world is the health of the environment, and the problems for the environment caused by economic development and population growth. We describe four specific policy areas that might be enlightened by referring to well-being measures: the impact of aircraft noise, the effects of air pollution, problems arising in conjunction with commuting, and the influence of parks and green spaces on well-being. In each of these instances, existing well-being data indicate that the subjective well-being of people is influenced by environmental conditions, and measures of well-being are one method by which interventions to correct environmental problems can be assessed. Furthermore, well-being measures can help suggest which of various interventions might be most effective in ameliorating the problems. It is emphasized that the existing well-being data are often not sufficient for fully informing policy discussions. Rather, the potential for adequate data, when it becomes available, to inform policy is emphasized.
Chapter 13 Conclusions
Authors: Diener Ed , Lucas Richard E. , Schimmack Ulrich , Helliwell John F.
Published: April 2010

Well-being measures can shed light on a large number of questions about diverse policy issues. Existing surveys are not sufficiently developed to offer definitive information, and therefore broad and ongoing accounts of well-being are needed. The well-being measures will not replace the information gained from existing social and economic measures but will complement it. The well-being measures have the ability to provide a broader perspective on quality of life than do measures that focus on a single objective such as economic growth. Although we do not fully understand well-being and the societal factors that influence it, it is nonetheless timely to implement national indicators of well-being because these measures are likely to inform the decisions of individual citizens as well as policy makers. Initial steps toward measuring societal well-being have already been taken in many nations, and show the promise of the well-being findings to create better policies. Although a full-blown set of national accounts of well-being are desirable, calculated steps to implement this goal incrementally can be taken, starting with the inclusion of life satisfaction and other measures in many ongoing studies and surveys.
Chapter 7 Social Identity and Citizenship in a Pluralistic Society
Authors: Brewer Marilynn B.
Published: April 2010

A large body of research has demonstrated the centrality of group identification to political behaviors and attitudes. This chapter examines the interrelationships among multiple overlapping group memberships, and the consequences of these dynamics for our understanding of citizenship in pluralistic democratic states. Social identity is critical to understanding citizenship and national attachment, with situational and motivational factors functioning to make these identities salient. This implies that national identity can come into conflict with competing subnational identities when role requirements between the two groups are incompatible, and when the two groups have distinct and incompatible group prototypes. The chapter explores the dynamics of the cross-cutting group identities in a pluralist democracy, and concludes that cross-cutting category structure and multiple social identities with awareness of ingroup diversity provide an effective formula for reducing intergroup prejudice and for promoting cultural pluralism.
Chapter 8 The Politics of Recognition: A Social Psychological Perspective
Authors: Conover Pamela Johnston
Published: April 2010

Political theory has been engaged in an ongoing debate about the role of recognition in liberal democracies. Recognition demands, among other things, respect for all social groups and their fundamental way of life. A failure to fulfill this demand can lead to discrimination and prejudice, and ultimately impedes effective democratic citizenship. This chapter argues that these claims are ultimately psychological in nature, and that psychological science provides evidence to support a politics of recognition. Specifically, psychological research suggests that misrecognition impedes democratic citizenship, and that meeting the demands of recognition can actually enhance the dynamics of democratic deliberation.
Policy Interventions
Authors: Baker C. Edwin
Published: April 2010

This chapter considers legal and other policy approaches to limit youth exposure to harmful media content. A wide range of arguments against censorship of problematic content is reviewed. In particular, it is difficult to identify problematic content and to enforce its suppression. Suppression often gives rise to other more problematic content. Censorship is also costly to enforce. Another concern is that the same media content can affect various people differently, so while suppressing content may limit harm to some, it could limit good to others (examples of this are in the chapter on the Internet). Regimes can abuse censorship, and censorship can limit the benefits gained from free expression. A better approach is for the government to promote desirable behavior, which generally works better than punishing bad behavior. Media literacy is an alternative to censorship, which in principle can favorably change reactions to and consumption of media content.
The Social Security Act in Perspective
Authors: Dobelstein Andrew W.
Published: April 2010

This chapter provides a broad overview of the social welfare programs authorized by the Social Security Act, both when it was created in 1935 and as they exist in 2009. A timeline shows how the Social Security Act has developed into the form in which we know it today, with twenty-one Titles, or parts, generating more than fifty of the nation's most significant social programs. The chapter distinguishes between the Act's social policy construction and the specific programs created from the policy — a distinction applied to all the Act's specific programs, discussed in subsequent chapters.
Title II: The Program Structure of Old Age, Survivors, and Disability Insurance
Authors: Dobelstein Andrew W.
Published: April 2010

What is commonly referred to as “Social Security” is a government-administered social insurance program that actually consists of three interlocking programs: Old Age Retirement Insurance, (often called “Social Security”), Survivors Insurance, and Disability Insurance. These programs make up the core of Title (i.e. part) II of the Social Security Act. From a straightforward retirement insurance program, Title II social insurance has grown incrementally to become the nation's largest and most complex social welfare commitment.
Title XVIII: Medicare Health Insurance for the Aged
Authors: Dobelstein Andrew W.
Published: April 2010

Since it was created in 1965, Medicare has become America's prototype for public health care. An entitlement program, Medicare Part A provides hospital insurance for social security beneficiaries, fully funded by the Federal government; and Medicare Part B provides Social security beneficiaries with a range of physician and health care services, funded mostly by a premium. Medicare Part D provides beneficiaries with prescription drugs, presumably at government subsidized prices. Medicare's growth illustrates the lack of clarity about goals for publicly financed health care, the fragmentation of health policy exacerbated by a health insurance model, and the politically fragile foundation for comprehensive health care in America.
Visuomotor representations
Authors: JACOB PIERRE , JEANNEROD MARC
Published: April 2010

This chapter considers both conceptual reasons and empirical evidence in favour of the dualistic model of the human visual system applied to the vision of objects. It examines the contribution of the visual system to a restricted class of human actions — reaching, grasping and manipulating objects in one's vicinity — and argues that one and the same visual stimulus can undergo perceptual processing or motor processing. It characterizes the major differences between these two kinds of processing of visual inputs, called ‘semantic’ and ‘pragmatic’ processing. The chapter makes the bold claim that a new kind of non-conceptual content has been discovered by the cognitive neuroscientific study of the visual system, i.e. visuomotor content.
Electrons and X-Rays Reveal the Structure of Rhodopsin: A Prototypical G Protein-Coupled Receptor-Implications for Colour Vision
Authors: Ruprecht Jonathan J. , Schertler Gebhard F. X.
Published: April 2010

A fundamental aim in vision research is to elucidate the factors that subtly modify the absorption maxima of the visual pigments — the G protein-coupled receptors (GPCRs) responsible for transducing visual stimuli. Humans have four visual pigments, found in the two classes of retinal cells responsible for light detection: rod cells for dim light detection and cones for colour vision. Human rod cells contain rhodopsin, which is important for vision in dim light and is currently the most intensively studied visual pigment. This chapter reviews the structural work that has been carried out on rhodopsin, with a view towards spectral tuning.
Lack Of S-Opsin Expression in the Brush-Tailed Porcupine (Atherurus Africanus) and Other Mammals. Is the Evolutionary Persistence of S-Cones a Paradox?
Authors: Ahnelt P. , Moutairou K. , Glösmann M. , Kübber-Heiss A.
Published: April 2010

This chapter describes the photoreceptor layer of the African brush-tailed porcupine (Atherurus africanus) and surveys the occurrence of secondary short wavelength cone (pigment) sensitivity loss. This loss is a seemingly frequent event in recent placental mammal evolution, and it contrasts with the long persistence of the S-cone system in the early Mesozoic mammals. The loss may point to changing roles of the short-wavelength-sensitive system during different stages of the mammalian evolution.
Psychophysical Correlates of Parvo- and Magnocellular Function
Authors: Smith Vivianne C. , Pokorny Joel
Published: April 2010

A contrast discrimination technique was developed that revealed parvocellular (PC)- and magnocellular (MC)-pathway function by taking advantage of their differences in achromatic contrast response. Spatiotemporal processing for these pathways was evaluated using achromatic stimuli. The signals leaving the retina are subject to considerable further processing by higher visual processes. By biasing the early retinal processing to one or other pathway, different properties of higher order processes can be accessed. This chapter reviews these studies, indicating the possible clinical applications of the approach.
Sensitivity to Movement of Configurations of Achromatic and Chromatic Points in Amblyopic Patients
Authors: De Mattiello M. L. F. , Maneiro M. , Buglione S.
Published: April 2010

Amblyopia has been attributed to a shift in sensitivity of the visual system toward low spatial-frequency filter mechanisms. This chapter analyzes the capacity to recognize moving signals and how colour can help in this task. It shows that changes in perceived form or colour can cause changes in perceived motion.
Macular Pigment: Nature’s Notch Filter
Authors: Moreland J. D. , Westland S.
Published: April 2010

Macular pigment (MP) is a natural filter with ‘notch’ transmission characteristics. This chapter examines the effects of MP on surface colours in Normal and Anomalous Trichromats for a database of 1782 reflectance spectra. The results show that increases in MP concentration produce a general clockwise rotation of chromaticity around the illuminant point for Normals and Anormals. The chromaticity shifts, associated with rotation, increase with distance from the illuminant point.
How to Find a Tritan Line
Authors: Smithson H. E. , Sumner P. , Mollon J. D.
Published: April 2010

This chapter proposes transient tritanopia as an effective method for locating an individual's tritan line. The method has several practical advantages. Firstly, the procedure can be carried out using a CRT, without the need to construct a uniform auxiliary field. Secondly, it allows almost free choice of the spatial properties of the stimulus so that the experimenter can determine the tritan line for the exact retinal region to be used in a subsequent experiment.
Effects of Retinal Detachment on S And M Cone Function In An Animal Model
Authors: Jacobs Gerald H , Calderone Jack B. , Sakai Tsutomu , Lewis Geoffrey P. , Fisher Steven K.
Published: April 2010

This chapter shows that retinal detachment in the ground squirrel model does not have a larger impact on S-cone than on M-cone function as indexed by signals originating in the outer retina. To the contrary, to the extent that there is any differential effect of detachment on function subserved by the two cone types, the results suggest that the loss may be slightly in the opposite direction, that is, a proportionally greater effect of detachment on M-cone than on the S-cone function.
Colour-Vision Disturbances in Patients With Arterial Hypertension
Authors: Schröder Anke , Erb Carl , Falk Stefan , Schwartze Gabriele , Radermacher Jörg , Winter Rolf
Published: April 2010

This chapter examines colour vision in patients with an early stage of arterial hypertension without end-organ damage. A significantly higher median error score in Roth's 28-hue (E) desaturated colour-arrangement test was observed for patients with arterial hypertension than for the control group. These results should be taken into account in colour-vision testing to avoid diagnostic interference between specifically ocular diseases (e.g. glaucoma) and arterial hypertension.
Models of amino acid and codon substitution
Authors: YANG ZIHENG
Published: April 2010

Chapter 1 discussed continuous-time Markov chain models of nucleotide substitution and their application to estimate the distance between two nucleotide sequences. This chapter discusses similar Markov chain models to describe substitutions between amino acids in proteins or between codons in protein-coding genes. It makes straightforward use of the Markov chain theory introduced in Chapter 1, except that the states of the chain are now the 20 amino acids or the 61 sense codons (in the universal genetic code), instead of the four nucleotides. Exercises are provided at the end of the chapter.
Maximum likelihood methods
Authors: YANG ZIHENG
Published: April 2010

This chapter discusses likelihood calculation for multiple sequences on a phylogenetic tree. As indicated at the end of Chapter 3, this is a natural extension to the parsimony method when we want to incorporate differences in branch lengths and in substitution rates between nucleotides. Likelihood calculation on a tree is also a natural extension to estimation of the distance between two sequences, discussed in Chapter 1. Exercises are provided at the end of the chapter.
BoolNet—an R package for generation, reconstruction and analysis of Boolean networks
Authors: Müssel Christoph , Hopfensitz Martin , Kestler Hans A.
Published: April 2010

Motivation: As the study of information processing in living cells moves from individual pathways to complex regulatory networks, mathematical models and simulation become indispensable tools for analyzing the complex behavior of such networks and can provide deep insights into the functioning of cells. The dynamics of gene expression, for example, can be modeled with Boolean networks (BNs). These are mathematical models of low complexity, but have the advantage of being able to capture essential properties of gene-regulatory networks. However, current implementations of BNs only focus on different sub-aspects of this model and do not allow for a seamless integration into existing preprocessing pipelines.

Results:  BoolNet efficiently integrates methods for synchronous, asynchronous and probabilistic BNs. This includes reconstructing networks from time series, generating random networks, robustness analysis via perturbation, Markov chain simulations, and identification and visualization of attractors.

Availability: The package BoolNet is freely available from the R project at http://cran.r-project.org/ or http://www.informatik.uni-ulm.de/ni/mitarbeiter/HKestler/boolnet/ under Artistic License 2.0.

Contact:  hans.kestler@uni-ulm.de

Supplementary information:  Supplementary data are available at Bioinformatics online.
VSDocker: a tool for parallel high-throughput virtual screening using AutoDock on Windows-based computer clusters
Authors: Prakhov Nikita D. , Chernorudskiy Alexander L. , Gainullin Murat R.
Published: April 2010

Summary: VSDocker is an original program that allows using AutoDock4 for optimized virtual ligand screening on computer clusters or multiprocessor workstations. This tool is the first implementation of parallel high-performance virtual screening of ligands for MS Windows-based computer systems.

Availability: VSDocker 2.0 is freely available for non-commercial use at http://www.bio.nnov.ru/projects/vsdocker2/

Contact:  nikita.prakhov@gmail.com

Supplementary information:  Supplementary data are available at Bioinformatics online.
Enterobius vermicularis in the kidney: an unusual location
Authors: Cateau Estelle , Yacoub Mokrane , Tavilien Christian , Becq-Giraudon Bertrand , Rodier Marie-Hélène
Published: April 2010

A woman was admitted to hospital with abdominal pain. A large kidney stone was recovered and a nephrectomy was performed. Histology revealed the unusual presence of multiple Enterobius vermicularis ova. However, no other parasitic element was recovered on further investigations.
Use of optical mapping to sort uropathogenic Escherichia coli strains into distinct subgroups
Authors: Schwan William R. , Briska Adam , Stahl Buffy , Wagner Trevor K. , Zentz Emily , Henkhaus John , Lovrich Steven D. , Agger William A. , Callister Steven M. , DuChateau Brian , Dykes Colin W.
Published: April 2010

Optical maps were generated for 33 uropathogenic Escherichia coli (UPEC) isolates. For individual genomes, the NcoI restriction fragments aligned into a unique chromosome map for each individual isolate, which was then compared with the in silico restriction maps of all of the sequenced E. coli and Shigella strains. All of the UPEC isolates clustered separately from the Shigella strains as well as the laboratory and enterohaemorrhagic E. coli strains. Moreover, the individual strains appeared to cluster into distinct subgroups based on the dendrogram analyses. Phylogenetic grouping of these 33 strains showed that 32/33 were the B2 subgroup and 1/33 was subgroup A. To further characterize the similarities and differences among the 33 isolates, pathogenicity island (PAI), haemolysin and virulence gene comparisons were performed. A strong correlation was observed between individual subgroups and virulence factor genes as well as haemolysis activity. Furthermore, there was considerable conservation of sequenced-strain PAIs in the specific subgroups. Strains with different antibiotic-resistance patterns also appeared to sort into separate subgroups. Thus, the optical maps distinguished the UPEC strains from other E. coli strains and further subdivided the strains into distinct subgroups. This optical mapping procedure holds promise as an alternative way to subgroup all E. coli strains, including those involved in infections outside of the intestinal tract and epidemic strains with distinct patterns of antibiotic resistance.
Regulation of the Klebsiella pneumoniae Kpc fimbriae by the site-specific recombinase KpcI
Authors: Wu Chien-Chen , Huang Ying-Jung , Fung Chang-Phone , Peng Hwei-Ling
Published: April 2010

In the genome of Klebsiella pneumoniae NTUH-K2044, nine fimbrial gene clusters were identified. Besides type 1 and type 3 fimbriae, the others are novel and were named Kpa, Kpb, Kpc, Kpd, Kpe, Kpf and Kpg fimbriae. Prevalence analysis among 105 K. pneumoniae clinical isolates revealed that the kpc genes were highly associated with the K1 serotype isolates. Induced expression of the recombinant kpcABCD genes in Escherichia coli resulted in Kpc fimbriation and increased biofilm formation. A putative site-specific recombinase encoding gene kpcI and a 302 bp intergenic DNA flanked by 11 bp inverted repeats, namely kpcS, were identified in the upstream region of the kpcABCD genes. Using LacZ as the reporter, a dramatic difference in promoter activity of kpcS in two different orientations was observed and accordingly assigned as ON and OFF phase. kpcI expression was found to be able to invert kpcS in trans from phase ON to OFF and vice versa. Using the two-plasmid system, expression of kpcA, encoding the major component of the Kpc fimbriae, could be observed upon the induced expression of kpcI. These results indicate that KpcI is involved in the regulation of Kpc fimbriation in a phase-variable manner.
Characterization of a β-hydroxybutyryl-CoA dehydrogenase from Mycobacterium tuberculosis
Authors: Taylor Rebecca C. , Brown Alistair K. , Singh Albel , Bhatt Apoorva , Besra Gurdyal S.
Published: April 2010

The lipid-rich cell wall of mycobacteria is essential not only for virulence but also for survival. Whilst anabolic pathways for mycobacterial lipid biosynthesis have been well studied, there has been little research looking into lipid catabolism. The genome of Mycobacterium tuberculosis encodes multiple enzymes with putative roles in the β-oxidation of fatty acids. In this report we explore the functionality of FadB2, one of five M. tuberculosis homologues of a β-hydroxybutyryl-CoA dehydrogenase, an enzyme that catalyses the third step in the β-oxidation cycle. Purified M. tuberculosis FadB2 catalysed the in vitro NAD+-dependent dehydration of β-hydroxybutyryl-CoA to acetoacetyl-CoA at pH 10. Mutation of the active-site serine-122 residue resulted in loss of enzyme activity, consistent with the function of FadB2 as a fatty acyl dehydrogenase involved in the β-oxidation of fatty acids. Surprisingly, purified FadB2 also catalysed the reverse reaction, converting acetoacetyl-CoA to β-hydroxybutyryl-CoA, albeit in a lower pH range of 5.5–6.5. Additionally, a null mutant of fadB2 was generated in Mycobacterium smegmatis. However, the mutant showed no significant differences from the wild-type strain with regard to lipid composition, utilization of different fatty acid carbon sources and tolerance to various stresses; the absence of any phenotype in the mutant strain could be due to the potential redundancy between the five M. smegmatis fadB paralogues.
The dddP gene of Roseovarius nubinhibens encodes a novel lyase that cleaves dimethylsulfoniopropionate into acrylate plus dimethyl sulfide
Authors: Kirkwood Mark , Le Brun Nick E. , Todd Jonathan D. , Johnston Andrew W. B.
Published: April 2010

The cloneddddPgene of the marine bacteriumRoseovarius nubinhibensallowsEscherichia colito form the volatile dimethyl sulfide (DMS) from dimethylsulfoniopropionate (DMSP), an abundant anti-stress compatible solute made by many marine plankton and macroalgae. Using purified DddP, we show here that this enzyme is a DMSP lyase that cleaves DMSP to DMS plus acrylate. DddP forms a functional homodimeric enzyme, has a pH optimum of 6.0 and was aKmof ∼14 mM for the DMSP substrate. DddP belongs to the M24B family of peptidases, some members of which have metal cofactors. However, the metal chelators EDTA and bipyridyl did not affect DddP activityin vitroand the as-isolated enzyme did not contain metal ions. Thus, DddP resembles those members of the M24B family, such as creatinase, which also act on a non-peptide substrate and have no metal cofactor. Site-directed mutagenesis of the active-site region of DddP completely abolished its activity. Another enzyme, termed DddL, which occurs in other alphaproteobacteria, had also been shown to generate DMS plus acrylate from DMSP. However, DddL and DddP have no sequence similarity to each other, so DddP represents a second, wholly different class of DMSP lyase.
Do the health‐care workers gain protection against herpes zoster infection? A 6‐year population‐based study in Taiwan
Authors: WU Chen‐Yi , HU Hsiao‐Yun , HUANG Nicole , PU Cheng‐Yun , SHEN Hsi‐Che , CHOU Yiing‐Jeng
Published: April 2010

Varicella zoster virus (VZV) causes varicella, and may reactivate to cause herpes zoster later in the life of the host. It has been previously observed that exposure to VZV may boost the host’s latent immunity. Health‐care workers who are frequently exposed to ill patients ought to receive a protective effect. We investigated the incidence of herpes zoster among health‐care workers and the general population in Taiwan to see whether such a protective effect exists among health‐care workers against herpes zoster. This nationwide population‐based retrospective cohort study was based on data obtained from the Taiwan National Health Insurance Database. In total, 7744 health‐care workers, including 168 dermatologists and pediatricians, and 695 188 general adults were recruited for the study. Health‐care workers in the age groups 20–29, 30–39 and 40–49 years were found to have a significant higher herpes zoster incidence compared to the general adults (P < 0.001, 0.011 and <0.001, respectively). Both logistic regression and Cox regression showed that dermatologists, pediatricians, and other medical professionals have a higher herpes zoster incidence than the general population (odds ratio [OR] = 1.36, 95% confidence interval [95% CI] = 0.63–2.90, hazards ratio [HR] = 1.35, 95% CI = 0.64–2.82 in dermatologist and pediatrician groups, and OR = 1.39, 95% CI = 1.23–1.58, HR = 1.38, 95% CI = 1.22–1.56 in other medical professionals). The incidence of herpes zoster is higher among health‐care workers and it can be clearly concluded that no protective effect against herpes zoster exists for health‐care workers in Taiwan.
Retinyl retinoate induces hyaluronan production and less irritation than other retinoids
Authors: KIM Jin Eun , KIM Bora , KIM Hyuk , KIM Hyojung , LEE Joo Dong , KIM Hyun Jung , CHOI Kang Yell , LEE Seung Hun
Published: April 2010

Hyaluronan, a non‐sulfated glycosaminoglycan, retains water, maintains the extracellular spaces and facilitates the transport of ion solutes and nutrients. Hyaluronan is closely involved in keratinocyte proliferation, migration and differentiation. The synthesis of hyaluronan in vitro can be stimulated by several growth factors, including retinoids, dibutyryl cyclic adenosine monophosphate and peroxisome proliferator‐activated receptor‐α agonist. In this study, we examined retinyl retinoate (a novel retinol derivative) on hyaluronan expression in primary human keratinocytes and in hairless mouse epidermal skin. Histochemistry using hyaluronan‐binding protein revealed that topical retinyl retinoate increased the intensity of hyaluronan staining in murine skin. Moreover, topical retinyl retinoate increased CD44 (hyaluronan receptor) expression. Using reverse transcription polymerase chain reaction, we assessed the expression level of the hyaluronan synthase 2 (HAS2) gene in primary human keratinocytes and in hairless mouse epidermal skin. We found that retinyl retinoate upregulated mouse HAS2 and human HAS2 mRNA. Application of retinyl retinoate induced increasing transepidermal water loss less than retinol, retinoic acid and retinaldehyde. Taken together, we suggest that retinyl retinoate is more effective on hyaluronan production and less of an irritant than other retinoids.
Pharmacogenomics of metabotropic glutamate receptor subtype 1 and in vivo malignant melanoma formation
Authors: ABDEL‐DAIM Mohamed , FUNASAKA Yoko , KOMOTO Mari , NAKAGAWA Yoko , YANAGITA Emmy , NISHIGORI Chikako
Published: April 2010

We have previously shown that ectopic expression of metabotropic glutamate receptor subtype 1 in melanocytes is essential for both development and in vivo growth of melanoma using newly developed transgenic mice which conditionally express metabotropic glutamate receptor subtype 1 (mGluR1). In this study, we developed conditional transgenic mice, which harbor melanocytes not only in the dermis and hair follicles but also in the epidermis using stem cell factor transgenic mice. Pigmented plaques on the backs, tails, ears or groins of the transgenic mice began to appear 13 weeks after activation of the mGluR1 transgene, and the transgenic mice produced melanomas at a frequency of 100% 36 weeks after transgene activation. Although this transgenic mouse harbors melanocytes in the epidermis, proliferation of melanoma cells took place in the dermis. To elucidate the signals involved in development and growth of melanoma, inhibitors to phospholipase C, protein kinase C and mitogen‐activated protein kinase kinase 1/2, and antagonists to Ca2+ and calmodulin were administrated to transgenic mice. Each signal inhibitor to phospholipase, protein kinase C, Ca2+ release, calmodulin and mitogen‐activated protein kinase kinase 1/2 inhibited melanoma development. However, once melanoma was developed, the growth of melanoma was dramatically inhibited only by the inhibitor to mitogen‐activated protein kinase kinase 1/2 with partial inhibition by inhibitors to protein kinase C and phospholipase C. This inhibition of melanoma growth was well correlated with the expression of phosphorylated extracellular signal‐regulated kinase 1/2 and Ki‐67. These results indicate that for development of melanoma, activation of every signaling pathway from mGluR1 is required. However, for growth of melanoma, the extracellular signal‐regulated kinase pathway plays a key role.
Hearing screening for school children: comparison of low‐cost, computer‐based and conventional audiometry
Authors: McPherson B. , Law M. M. S. , Wong M. S. M.
Published: April 2010

Background  There is a need to develop affordable but effective audiometric screening equipment, particularly for use in low‐income countries. With advances in computer technology, low‐cost computer‐based audiometer software has been developed. However, the efficacy of computer‐based audiometers in hearing screening and diagnostic assessment requires investigation. The purpose of this study was to evaluate the accuracy of a low‐cost, computer‐based audiometric system in a school‐based hearing screening programme.

Methods  Eighty children were screened using the computer‐based audiometer and with a conventional pure tone screening audiometer. Overall refer rates, as well as frequency and age effects on the accuracy of the computer‐based audiometer, were considered.

Results  There was a significant relationship between the low‐cost, computer‐based audiometer and a conventional pure tone audiometer when a 40 dBHL refer criterion was used in school hearing screening and when test results at 500 Hz were excluded from analysis. However, background noise effects and software limitations in the computer‐based system had major adverse effects on screening performance.

Conclusions  The study results and preliminary practical experience with the system suggest that, with further software and hardware improvements, a low‐cost, computer‐based system may well be feasible for routine school screening in developing countries.
Sources of small‐scale variation in the invertebrate communities of headwater streams
Authors: LeCRAW ROBIN , MACKERETH ROBERT
Published: April 2010

1. Our objective was to investigate the associations between benthic macro‐invertebrate communities and environmental factors described at three spatial scales: local, reach and catchment. Differences in these associations, because of local topography, were determined by categorising sites into those having a large or small ‘reach contributing area’ (RCA), which is the lateral area of land contributing surface and subsurface flow of water, nutrients, organic and inorganic materials to a stream reach independent of catchment size and upstream contributions, and created by local topography.

2. Twenty‐three sites were sampled in the Lake Nipigon Forest in north‐western Ontario. Local variables included hydrological metrics and stream morphology characteristics. Terrestrial reach and catchment variables included forest characteristics, topography and geomorphology. Invertebrates were identified and classified into functional feeding guilds. Canonical correspondence analysis and redundancy analysis were used to determine which variables contributed most to macro‐invertebrate community structure and how the RCA influenced those associations.

3. Overall, local‐scale variables explained most variation in taxonomic and functional community structure (51.6 and 59.1%). Catchment‐scale variables explained more variation in the community (43.9 and 43.5%) than reach‐scale variables. In sites with a large RCA, the reach‐scale variables accounted for almost 10% more variability in taxonomic structure than the catchment‐scale variables, and in sites with a small RCA, catchment‐scale variables explained almost 23% more variation in feeding guild structure than reach‐scale variables.

4. Topography was important at both the reach and the catchment scales. Variables at the reach scale most associated with invertebrate community tended to be related to forest cover, whereas important variables at the catchment scale were related to topography, wetlands and lakes.

5. The difference in associations between invertebrate communities and environmental factors based on RCA indicates the influence of local topography on the linkage between aquatic habitats and the surrounding terrestrial environment. Understanding how these linkages affect aquatic communities can help to develop more effective predictive models of invertebrate community and more prescriptive conservation and management strategies for small streams.
Role of SOX2 in maintaining pluripotency of human embryonic stem cells
Authors: Adachi Keiko , Suemori Hirofumi , Yasuda Shin‐ya , Nakatsuji Norio , Kawase Eihachiro
Published: April 2010

Human embryonic stem cell (ESC) pluripotency is thought to be regulated by several key transcription factors including OCT4, NANOG, and SOX2. Although the functions of OCT4 and NANOG in human ESCs are well defined, that of SOX2 has not been fully characterized. To investigate the role of SOX2, we modulated the level of SOX2 expression in human ESCs. Reduction of SOX2 expression in human ESCs induced trophectodermal and partial endodermal differentiation. Interestingly, CDX2, a typical trophectoderm‐associated gene, was not up‐regulated. In contrast, using the Tet‐on gene inducible system, SOX2 over‐expression in human ESCs induced trophectoderm differentiation accompanied by increased CDX2 expression. Additionally, SOX2 over‐expression resulted in an increase in CGα‐positive cells, which marks later stage trophectoderm development, rather than placental lactogen‐positive cells. Thus, over‐expression as well as repression of SOX2 expression in human ESCs resulted in their differentiation into the trophectoderm lineage. Our data show that SOX2 plays an important role in the maintenance of pluripotency of human ESCs and possibly, trophoblast development.
Thrombin generation in patients with factor XI deficiency and clinical bleeding risk
Authors: RUGERI L. , QUÉLIN F. , CHATARD B. , DE MAZANCOURT P. , NEGRIER C. , DARGAUD Y.
Published: April 2010

Summary.  Factor XI (FXI) deficiency is a rare bleeding disorder. Most patients with FXI deficiency are mild bleeders but certain patients with similar FXI activity exhibit different bleeding phenotype. Routine laboratory assays do not help physicians to estimate the individual bleeding risk in these patients. Thrombin generation test (TGT) is a more comprehensive, global function test of the clotting system. We investigated whether or not the bleeding tendency of patients with FXI deficiency is correlated with features of the TGT. Twenty‐four patients with FXI deficiency were divided in two groups: (i) severe bleeders (n = 9) and (ii) mild or non‐bleeders (n = 15). All severe bleeders had a personal history of surgery‐related severe bleeding. Thrombin generation (TG) was measured in platelet‐rich plasma (PRP) using a low concentration of tissue factor 0.5 pm. In patients exhibiting severe bleeding tendency, independently of their FXI level, a dramatically impaired TG was observed. For example, despite a low plasma FXI = 1 IU dl−1, a clinically non‐bleeding individual exhibited normal TG results whereas another patient with severe bleeding history and FXI = 40 IU dl–1 had a very low TG capacity. Low velocity and delayed TG were the main parameters suggesting a higher bleeding risk. DNA analysis of patients reported eight novel mutations of the FXI gene but neither mutation location nor secretion or not of the variant correlated with the bleeding tendency. The results of this study suggest that TG measurement in PRP may be a useful tool to predict bleeding risk in FXI deficiency and should be studied further in larger prospective clinical studies.
Host behaviour and exposure risk in an insect–pathogen interaction
Authors: Parker Benjamin J. , Elderd Bret D. , Dwyer Greg
Published: April 2010

1. Studies of variability in host resistance to disease generally emphasize variability in susceptibility given exposure, neglecting the possibility that hosts may vary in behaviours that affect the risk of exposure.

2. In many insects, horizontal transmission of baculoviruses occurs when larvae consume foliage contaminated by the cadavers of virus‐infected conspecific larvae; so, host behaviour may have a strong effect on the risk of infection.

3. We studied variability in the behaviour of gypsy moth (Lymantria dispar) larvae, which are able to detect and avoid virus‐contaminated foliage.

4. Our results show that detection ability can be affected by the family line that larvae originate from, even at some distance from a virus‐infected cadaver, and suggest that cadaver‐detection ability may be heritable.

5. There is thus the potential for natural selection to act on cadaver‐detection ability, and thereby to affect the dynamics of pathogen‐driven cycles in gypsy moth populations.

6. We argue that host behaviour is a neglected component in studies of variability in disease resistance.
Chronic monolateral otomycosis in a dog caused by Aspergillus ochraceus
Authors: Ghibaudo Giovanni , Peano Andrea
Published: April 2010

Aspergillus ochraceus, a widely distributed filamentous fungus, was isolated and identified by cytology and culture as the cause of unilateral ceruminous purulent otitis in a 4‐year‐old male mixed‐breed dog. The pathogenic role of the fungal isolate was confirmed by a good response to antifungal therapy and the absence of other pathogens. No underlying diseases were identified and the dog recovered after 3 weeks of therapy with oral itraconazole and topical miconazole.
Determination of mismatched donor HLA in kidney transplant recipients with unknown donor HLA phenotypes
Authors: Kwok Janette , Chan Gavin S. W. , Lam M. F. , Yan Tony , Tang Lydia , Kwong K. M. , Chan K. W. , Chan T. M.
Published: April 2010

Kwok J, Chan GSW, Lam MF, Yan T, Tang L, Kwong KM, Chan KW, Chan TM. Determination of mismatched donor HLA in kidney transplant recipients with unknown donor HLA phenotypes. Clin Transplant 2010 DOI: 10.1111/j.1399‐0012.2010.01246.x  © 2010 John Wiley & Sons A/S.

Abstract: Objective: To determine donor human leukocyte antigen (HLA) from renal allograft biopsies in transplant recipients whose donor HLA phenotype is not known.

Methods: Renal allograft biopsies were obtained from seven renal transplant recipients when indicated for allograft dysfunction or proteinuria. DNA was extracted fresh from allograft specimens, and HLA typing was performed with polymerase chain reaction‐specific sequence primers (PCR‐SSP) and polymerase chain reaction‐sequence‐specific oligonucleotides (PCR‐SSO).

Results: HLA typing of the seven renal allograft biopsies was composed of both recipient and donor HLA phenotypes, allowing the determination of the donor HLA and the degree of HLA mismatching.

Conclusions: Deducing mismatched donor HLA antigens in renal allograft recipients enables detection of donor‐specific antibodies, and the management of humoral rejection, and enables more appropriate selection of a donor organ should future retransplantation be required.