bluuebunny/crossref_metadata_2025 huggingface dataset:
ON HAWKING RADIATION AS TUNNELING WITH LOGARITHMIC CORRECTIONS
Authors: MEDVED A. J. M. , VAGENAS ELIAS C.
Published: July 2005

There has been recent speculation that the tunneling paradigm for Hawking radiation could — after quantum-gravitational effects have suitably been incorporated — provide a means for resolving the (black hole) information loss paradox. A prospective quantum-gravitational effect is the logarithmic-order correction to the Bekenstein–Hawking entropy/area law. In this paper, it is demonstrated that, even with the inclusion of the logarithmic correction (or, indeed, the quantum correction up to any perturbative order), the tunneling formalism is still unable to resolve the stated paradox. Moreover, we go on to show that the tunneling framework effectively constrains the coefficient of this logarithmic term to be non-negative. Significantly, the latter observation implies the necessity for including the canonical corrections in the quantum formulation of the black hole entropy.
LINEAR AND NONLINEAR KORN INEQUALITIES ON CURVES IN ℝ3
Authors: MARDARE SORIN , SZOPOS MARCELA
Published: July 2005

We establish several linear and nonlinear inequalities of Korn's type for curves in the three-dimensional Euclidean space. These inequalities are obtained under weak regularity assumptions on the curve of reference. We also establish an infinitesimal rigid displacement lemma for curves.
NONLINEARLY ELASTIC THIN PLATE MODELS FOR A CLASS OF OGDEN MATERIALS II: THE BENDING MODEL
Authors: TRABELSI KARIM
Published: July 2005

This paper is a sequel to Part I (Trabelsi [11]) in which a new two-dimensional membrane model was derived via a formal asymptotic procedure for a family of hyperelastic nonlinear materials proposed by Ciarlet and Geymonat whose stored energy function is polyconvex and becomes infinite when the determinant of the deformation gradient tends to zero, and can be adjusted to arbitrary Lamé constants. Here, we continue the asymptotic analysis by making legitimate assumptions on the data to produce an inextensional two-dimensional model.
UPPER AND LOWER BOUNDS FOR A RATIO INVOLVING THE GAMMA FUNCTION
Authors: KERSHAW D.
Published: July 2005

Let ψ = Γ′/Γ, where Γ is the Gamma function, and let x ≥ 0 and 0 < a ≤ b. Then [Formula: see text]
ISOPERIMETRIC INEQUALITY FOR A CORNER HELE–SHAW DYNAMICS
Authors: VASIL'EV ALEXANDER
Published: July 2005

We consider a two-dimensional Hele–Shaw flow in a wedge under injection into wedge's vertex. An isoperimetric inequality is obtained. It shows that the rate of the area growth is controlled by a special conformal quantity-triangle conformal radius.
WEIGHTED THIN PLATE SPLINES
Authors: BOUHAMIDI A.
Published: July 2005

A widely known method in multivariate interpolation and approximation theory consists of the use of thin plate splines. In this paper, we investigate some results and properties relative to a wide variety of variational splines in some space of functions arising from a nonnegative weight function. This model includes thin plate splines, splines in tension and discusses smoothing and interpolating splines. Pointwise error estimates are given for both problems.
PROSTAGLANDINS AND OTHER EICOSANOIDS IN INSECTS: Biological Significance
Authors: Stanley David
Published: July 2005

▪ Abstract  Prostaglandins and other eicosanoids are oxygenated metabolites of certain polyunsaturated fatty acids. These compounds are well known for their important actions in mammalian physiology and disease. Recent work has revealed the presence and biological actions of eicosanoids in insects and many other invertebrate animals. In insects, eicosanoids mediate cellular immunity to microbial and metazoan challenge. Notably, some infectious organisms secrete factors responsible for impairing host insect immune reactions by inhibiting biosynthesis of eicosanoids. Eicosanoids also act in insect reproductive biology, in ion transport physiology, and in fever response to infection as well as in protein exocytosis in tick salivary glands. Aside from ongoing actions in homeostasis, certain eicosanoid actions occur at crucial points in insect life histories, such as during infectious challenge and important events in reproduction.
INVASION BIOLOGY OF THRIPS
Authors: Morse Joseph G. , Hoddle Mark S.
Published: July 2005

▪ Abstract  Thrips are among the stealthiest of insect invaders due to their small size and cryptic habits. Many invasive thrips are notorious for causing extensive crop damage, vectoring viral diseases, and permanently destabilizing IPM systems owing to irruptive outbreaks that require remediation with insecticides, leading to the development of insecticide resistance. Several challenges surface when attempting to manage incursive thrips species. Foremost among these is early recognition, followed by rapid and accurate identification of emergent pest species, elucidation of the region of origin, development of a management program, and the closing of conduits for global movement of thrips. In this review, we examine factors facilitating invasion by thrips, damage caused by these insects, pre- and post-invasion management tactics, and challenges looming on the horizon posed by invasive Thysanoptera, which continually challenge the development of sustainable management practices.
Emerging Inequalities in Central and Eastern Europe
Authors: Heyns Barbara
Published: July 2005

Market transitions are thought to inevitably produce spiraling inequality on the road to economic growth. This review provides an overview of research evaluating inequality in income and wages in Central and Eastern Europe since 1989. The empirical studies agree that inequality has increased, but disagree about the amount, pace, source, and explanation of change. Patterns of inequality are unrelated to economic performance, to the pace or timing of reform, or to rates of subsequent growth. Inequality increased the most in the least successful countries and the least in those countries with historic cultural connections to the West. Inequalities by age, education, region of the country, and health status increased; differences by gender appear to have declined. Although data are plentiful and promising, it is not yet possible to conclude that patterns of inequality among postcommunist countries are due to the genesis of capitalism, to social and cultural assimilation to the West, to adaptations of redistributive institutions to deal with poverty and unemployment, or to globalization.
Affirmative Action at School and on the Job
Authors: Harper Shannon , Reskin Barbara
Published: July 2005

Affirmative action (AA) addresses individuals' exclusion from opportunities based on group membership by taking into account race, sex, ethnicity, and other characteristics. This chapter reviews sociological, economic, historical, and legal scholarship on AA. We first consider the emergence of group-based remedies, how protected groups are defined, and proportional representation as a standard for inclusion. We then summarize the research on AA in education (including busing) and in employment. The concluding section reviews societal responses to AA, including attitudes, challenges, and political responses. As public and judicial support for AA has waned, employers and educators have increasingly turned toward diversity as a rationale for including underrepresented groups. Despite this change, many employers and educators continue to take positive steps to include minorities and women.
Neutrophil Depletion Inhibits Experimental Abdominal Aortic Aneurysm Formation
Authors: Eliason Jonathan L. , Hannawa Kevin K. , Ailawadi Gorav , Sinha Indranil , Ford John W. , Deogracias Michael P. , Roelofs Karen J. , Woodrum Derek T. , Ennis Terri L. , Henke Peter K. , Stanley James C. , Thompson Robert W. , Upchurch Gilbert R.
Published: July 2005

Background—

Neutrophils may be an important source of matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9), two matrix-degrading enzymes thought to be critical in the formation of an abdominal aortic aneurysm (AAA). The purpose of this investigation was to test the hypothesis that neutrophil depletion would limit experimental AAA formation by altering one or both of these enzymes.

Methods and Results—

Control, rabbit serum–treated (RS; n=27) or anti-neutrophil-antibody–treated (anti-PMN; n=25) C57BL/6 mice underwent aortic elastase perfusion to induce experimental aneurysms. Anti-PMN–treated mice became neutropenic (mean, 349 cells/μL), experiencing an 84% decrease in the circulating absolute neutrophil count (
P
<0.001) before elastase perfusion. Fourteen days after elastase perfusion, control mice exhibited a mean aortic diameter (AD) increase of 104±14% (
P
<0.0001), and 67% developed AAAs, whereas anti-PMN–treated mice exhibited a mean AD increase of 42±33%, with 8% developing AAAs. The control group also had increased tissue neutrophils (20.3 versus 8.6 cells per 5 high-powered fields [HPFs];
P
=0.02) and macrophages (6.1 versus 2.1 cells per 5 HPFs,
P
=0.005) as compared with anti-PMN–treated mice. There were no differences in monocyte chemotactic protein-1 or macrophage inflammatory protein-1α chemokine levels between groups by enzyme-linked immunosorbent assay. Neutrophil collagenase (MMP-8) expression was detected only in the 14-day control mice, with increased MMP-8 protein levels by Western blotting (
P
=0.017), and MMP-8–positive neutrophils were seen almost exclusively in this group. Conversely, there were no statistical differences in MMP-2 or MMP-9 mRNA expression, protein levels, enzyme activity, or immunostaining patterns between groups. When C57BL/6 wild-type (n=15) and MMP-8–deficient mice (n=17) were subjected to elastase perfusion, however, ADs at 14 days were no different in size (134±7.9% versus 154±9.9%;
P
=0.603), which suggests that MMP-8 serves only as a marker for the presence of neutrophils and is not critical for AAA formation.

Conclusions—

Circulating neutrophils are an important initial component of experimental AAA formation. Neutrophil depletion inhibits AAA development through a non–MMP-2/9–mediated mechanism associated with attenuated inflammatory cell recruitment.
Analysis of Mode I and Mode II Tests for Composites with Translaminar Reinforcements
Authors: Chen Leishan , Ifju Peter G. , Sankar Bhavani V.
Published: July 2005

This paper presents finite element models to determine the Mode I and Mode II fracture toughness of stitched composites in conjunction with experiments. Two new test methods to measure the Mode I and Mode II fracture toughness of stitched composites are developed. From the experimental load- deflection diagram, the effective fracture toughness can be determined by the area method. However, in order to comprehensively understand the effect of stitches, two parameters, Gc-par (parent material’s fracture toughness) and Gc-eff (effective fracture toughness) are needed to represent the fracture behavior of stitched composites. Gc-par is the intrinsic property of the parent material and is independent of stitch behavior. Gc-eff is the effective critical strain energy release rate that includes the effects of stitching. The purpose of performing the finite element analysis is to identify the correct physical models that represent the stitch interactions with the parent laminate and stitch failure mechanisms. Gc-par and Gc-eff can be obtained through different paths of the J-integral in the FE models. The models help in understanding the effects of stitch stiffness and spacing on the fracture toughness without the need for fabricating and testing stitched composite specimens.
Effect of Delaminations on Opening of Transverse Matrix Cracks
Authors: Noh Jae , Whitcomb John
Published: July 2005

The use of advanced composite materials for cryogenic fuel tanks reduces the mass of the structure but the leakage of fuel can become a problem. Since the amount of leakage increases with the crack opening, it is essential that we understand the factors that affect the crack opening. In previous studies by the authors, the opening and the degradation behavior of lamina properties due to transverse matrix cracking had been studied extensively. It has been found that the opening of transverse matrix cracks can be directly related to changes in effective moduli. This paper extends the earlier work to include the additional opening due to the delaminations induced at the tips of the transverse matrix crack. Finite element models have been built for seven delamination configurations. The opening and the stiffness degradation of laminates have been obtained as functions of the crack density and the delamination length. The effect of some factors such as adjacent ply orientation, ply thickness, and temperature on the opening have been studied. It has been found that the crack opening due to transverse crack-induced delaminations is still directly related to reduction in effective moduli. The opening increases almost linearly with the delamination length. A simple formula has been developed to predict the opening. The prediction of the opening obtained using this formula agreed very well with the finite element predictions.
Interaction between Cracking and Oxidation in Organic Matrix Composites
Authors: Colin X. , Mavel A. , Marais C. , Verdu J.
Published: July 2005

The thermal oxidative degradation of carbon fiber/bismaleimide (Hexel T800H/F655-2) and carbon fiber/amine-cross-linked epoxy (Cytec Fiberite IM7/977-2) unidirectional composites and their corresponding neat polymers has been studied in air at temperatures ranging from 150 to 240 C by optical microscopy, using an interferential contrast, and IR microspectrophotometry.

A coarse analysis of the damaged zone allowed the determination of main kinetic characteristics in the whole degradation process (oxidation, crack propagation, and their interaction) for each principal direction of the composite materials.

It has been found that cracks initiate at the sample free surfaces when a critical value of embrittlement is reached in the oxidized layer. Then, cracks propagate differently toward the core according to both the fiber orientation and the nature of the composite system. The difference in behavior between T800H/F655-2 and IM7/977-2 systems can be explained by a difference in polymer toughness and oxygen permeability of the fiber-matrix interface.
Winding Trajectory and Winding Time in Robotized Filament Winding of Asymmetric Shape Parts
Authors: Polini W. , Sorrentino L.
Published: July 2005

Robotized filament winding is a technology to deposit a roving on a die according to a planned robot trajectory and to polymerize the wound part in a furnace for thermoset resin matrix. In this way, it is possible to wind asymmetric or complex parts. The winding trajectory is a critical aspect of the robotized filament winding process, since the mechanical performances and the winding time of the manufactured composite part change according to winding trajectory geometry. The present work discusses original criteria for the determination of a proper winding system trajectory and its influence on the winding time. This work studies the influence of the geometric parameters, that characterize the trajectory covered by the deposition system to wind the roving on the die, on winding time. The obtained results may help to identify the values of the geometric parameters that minimize the winding time and, at the same time, that keep constant the winding tension in order to assure an acceptable quality of composite parts. This work represents the first step to optimize the planning of the winding trajectory.
Assessing Friendship Motivation During Preadolescence and Early Adolescence
Authors: Richard Jacques F. , Schneider Barry H.
Published: July 2005

The authors describe the development and initial psychometric properties of the Friendship Motivation Scale for Children, a new scale designed to assess four dimensions of self-determination (i.e., intrinsic motivation, identified regulation, external regulation, and amotivation) in preadolescents and early adolescents’ desire for friendships. The results—obtained with a sample of 490 fifth-, sixth-, and seventh-grade boys and girls— confirmed the factor structure of the scale and revealed adequate internal consistency and test-retest stability. Indicators of construct validity included (a) correlations among the four subscales displaying a simplex pattern, and thus supporting the underlying theoretical model (i.e., self-determination continuum); (b) friends generally reporting similar levels of friendship motivation; and (c) children more self-determined in their friendship motivation reporting more prosocial and less hostile goals in friendship conflict situations and reporting fewer feelings of loneliness. Girls reported greater self-determined friendship motivation than boys, and girls with greater self-determination were preferred by their peers as play-work companions.
Adolescent Victimization
Authors: Christiansen Elizabeth J. , Evans William P.
Published: July 2005

The present study examined how risk and protective factors were associated with adolescent victimization by testing four competing models from resiliency research—the compensatory, risk-protective, protective-protective, and challenge models. Models were tested separately by gender. The data for this study were based on a multistate project that surveyed 992 eighth-grade students between the ages of 12 and 15 years (54% female, 54% White) in at-risk urban and rural schools. Models incorporated family conflict, anger expression, external locus of control, witnessing violence, and involvement in risky behaviors as risk factors; protective factors included social connectedness, parental monitoring, and neighborhood cohesion. Results indicated support for the challenge model for both male and female early adolescents. Implications for prevention work and future research are discussed.
Peer Context of Mathematics Classroom Belonging in Early Adolescence
Authors: Hamm Jill V. , Faircloth Beverly S.
Published: July 2005

Classroom peer factors were examined for their role in African American and White early adolescents’ sense of belonging in mathematics classrooms. After controlling for fall sense of classroom belonging, spring sense of belonging was greater when teens perceived a more supportive peer context, minimal emotional risk in participating, and when they were recognized by peers as being strong math tutors. Additionally, naturally occurring peer groups were differentiated by sense of belonging of members; peer networks that began the year below average in sense of belonging became more alienated during the course of the year, whereas networks above average in belonging stayed at fall levels. The results are interpreted in relation to the benefits that specific peer relations offer aspects of adjustment such as belonging.
Psychosocial Influences on Physical, Verbal, and Indirect Bullying Among Japanese Early Adolescents
Authors: Ando Mikayo , Asakura Takashi , Simons-Morton Bruce
Published: July 2005

Although bullying among Japanese youth is a current major concern, psychosocial influences on bullying are not fully understood. The purpose of this study was to identify the psychosocial factors associated with physical, verbal, and indirect bullying among Japanese adolescents. Junior high school students between seventh and ninth grade (N = 2,923) completed a self-reported questionnaire. Involvement in bullying and psychosocial factors were investigated. Deviant peer influence, less serious attitude in school, poor self-control of aggressiveness and impulsiveness, poor self-assertive efficacy against bullying, and euphemistic thinking were commonly associated with physical, verbal, and indirect bullying. Experiences of victimization by physical and verbal bullying were associated with both physical and verbal bullying, whereas experiences of victimization by indirect bullying were associated with indirect bullying. Psychosocial factors associated with different types of bullying substantially overlapped. Therefore, interventions focused on these modifiable common factors could be effective in the prevention of adolescent bullying.
The Association Between Family Violence and Adolescent Dating Violence Onset
Authors: Foshee Vangie A. , Ennett Susan T. , Bauman Karl E. , Benefield Thad , Suchindran Chirayath
Published: July 2005

The authors determine if the associations between family violence(corporal punishment, violence against the child with the intention of harm, and witnessing violence between parents) and adolescent dating violence vary by subgroups based on race, socioeconomic status, and family structure. This study is guided by the theoretical propositions of Rowe, Vazsonyi, and Flannery (1994) related to examining subgroup differences and similarities in developmental processes. The sample is 1,218 early adolescents (56.6% female, 16.4% Black) who completed two self-administered questionnaires during 1 1/2 years. We found many subgroup differences in the associations between the family violence variables and dating violence; the most consistent being across race. In most cases, exposure to family violence predicted dating violence by Black adolescents but was not associated with dating violence for White adolescents. We also found within-race differences in the associations examined. Results are supportive of subgroup differences in developmental processes.
Making Classifications (at) Work
Authors: Roth Wolff-Michael
Published: July 2005

To make and use classifications is human. At least in the sciences, classification activities involve high degrees of uncertainty. Drawing on ethnography and conversation analysis of videotaped scientists, the activities of classifying and making classifications are analyzed considering four types of situations that arise when there is certainty or uncertainty about the object to be classified and the classification scheme to be used. As a collection, the different analyses of everyday scientific work articulate classification as a physically and temporally situated and socially distributed activity that does not eliminate uncertainty and inconsistency, but tends to minimize contradiction.
The Contract Research Organization and the Commercialization of Scientific Research
Authors: Mirowski Philip , Van Horn Robert
Published: July 2005

The early 1980s constituted a watershed in science, mainly concerning the extent and nature of globalization and commercialization of scientific research, and its impact upon the university. Considerable debate has arisen about the sources of this transition, but aside from a few lone voices, the scholarly literature has neglected the concurrent rise of the contract research organization (CRO) and its role in the commercialization of scientific research. The CRO warrants wider attention as a modern paradigm of privatized science in the biopharmaceutical sector. In discussing the CRO’s technologies, the purposes they pursue, and the legal and policy initiatives that have fostered their rapid rise, we confront the wider implications of the modern regime of commercialized science for the future conduct of scientific research. We identify five areas of innovation: treatment of human subjects, control of disclosure, subjection of research tools to commercialization, redefinition of authorship, and re-engineering the goals of research.
Scientific Journal Publications
Authors: Gunnarsdóttir Kristrún
Published: July 2005

The scientific community has begun using new information and communication technologies to increase the efficiency with which publications are disseminated. The trend is most marked in some areas of physics, where research papers are first circulated in the form of electronic unrefereed preprints through a service known as arXiv. In the first half of this paper, I explain how arXiv works, and describe the conceptual backstage and its growing influence. I will look at the motives behind the developing technologies and focus on the views of promoters and makers of the system. In the second half of the paper, I look at the eventual fate of papers initially circulated with arXiv. While it is argued that preprints are sufficient for the everyday scientific practice, nearly every paper in some specialities finds its way into formally peer-reviewed journals and proceedings. I argue that the continuation of traditional publication practices, in spite of their costs and inefficiencies when compared with arXiv, suggests that formally certified publication still has important roles. Certified publication verifies the relevance of scientific work and establishes professional credentials in the outer rings of the community, whose members are not sufficiently embedded in esoteric networks to make appropriate judgements on the basis of reading papers in isolation, or even through consultation.
Psychosocial Predictors and Correlates of Suicidality in Teenage Latino Males
Authors: Locke Thomas F. , Newcomb Michael D.
Published: July 2005

Multiple ecodevelopmental factors were tested as they influence suicidality in a community sample of Latino adolescent males. Risk factors tested included childhood maltreatment, parental alcohol-related problems, and polysubstance problems. Protective factors included general self-efficacy, social conformity, and family bonding. Male participants (N = 349) were recruited from the Los Angeles area. About 80% of the sample reported some suicidal ideation, and 26% reported a history of at least one suicide attempt. The strongest protective factor for suicidality was problem-solving confidence, followed by a good relationship with parents and being law abiding. The strongest risk factor for suicidality was emotional abuse, followed by hard drug use, mother’s alcohol-related problems, and sexual abuse. Broad-based theories, research, treatment, and prevention efforts are critical to implement with this population.
Implicit Stereotyping of Hispanics: Development and Validity of a Hispanic Version of the Implicit Association Test
Authors: Weyant James M.
Published: July 2005

The Implicit Association Test was adapted to assess the degree to which people hold, at least at an implicit level, a stereotype that Hispanics are less intelligent than Whites. On the test, a sample of 41 college students at a university in the United States showed significantly faster reaction times when faced with associations consistent with the stereotype than when faced with associations inconsistent with the stereotype. In addition, scores on the Implicit Association Test were positively correlated with scores on a modified Social Distance Scale. Thus, it was concluded that the adaptation of the Implicit Association Test is both sensitive enough to detect the hypothesized stereotypic belief and a valid test.
The Relationship of Language Brokering to Ethnic Identity for Latino Early Adolescents
Authors: Weisskirch Robert S.
Published: July 2005

Children of immigrant parents often translate written and face-to-face communication for parents and other adults, also known as language brokering. Fifty-five sixth-grade, Latino adolescents report their experiences and feelings toward language brokering, their level of acculturation, and their ethnic identity in a questionnaire. Generally, the participants view language brokering positively. Those who are less acculturated are translating more frequently than those who are more acculturated. Feelings toward language brokering also positively influence level of ethnic identity. This study demonstrates that language brokering may result in stronger feelings toward the ethnic group and greater ethnic identity.
The Language Translation Process in Survey Research: A Cost Analysis
Authors: Cantor Scott B. , Byrd Theresa L. , Groff Janet Y. , Reyes Yesenia , Tortolero-Luna Guillermo , Mullen Patricia Dolan
Published: July 2005

The purpose of this study is to conduct a cost analysis from an institutional perspective of translating an English-language survey instrument to Spanish. The authors conduct a process flow analysis of the steps required to create and validate a 30-page survey instrument with 211 items. The identified steps in the translation process cost $10,426. Personnel and overhead account for 60% and 33%, respectively, of the total costs. The detailed process of translating an English-language survey instrument to Spanish can be expensive but may be a critical component for the validity of a research study.
The Evaluation of a Latino Community Health Worker HIV Prevention Program
Authors: Martin Molly , Camargo Maria , Ramos Lori , Lauderdale Diane , Krueger Kristin , Lantos John
Published: July 2005

This study evaluated the effectiveness of a community health promotion project to increase HIV knowledge in an urban, immigrant Latino community in Chicago. Latino participants (N = 704) answered questions on HIV before and after an education intervention given by community health workers. Outcomes included changes in knowledge and self-perceived risk. Increases in knowledge scores were greatest for Central/South Americans (p = .038), women (p = .027), and those with an education level less than 7 years (p = .001). Significant changes in self-perceived risk resulted from the intervention (p < .001), and the odds ratio for a change in self-perceived risk when the knowledge score increased by 10% was 1.225. The Centro San Bonifacio HIV Prevention Program successfully reached a Latino community, increased HIV knowledge, and changed self-perceptions of HIV risk.
The Changing Image of Hispanic Americans
Authors: Weaver Charles N.
Published: July 2005

Data from surveys representative of the adult population of the United States were used to examine changes from 1990 to 2000 in the image of Hispanic Americans on wealth, work ethic, violence, and intelligence as seen by 2,226 European Americans, 90 Jewish Americans, 304 African Americans, and 205 Hispanic Americans. The image that European Americans and Jewish Americans had of Hispanics for wealth, work ethic, and intelligence improved significantly between the two time periods. For African Americans, only the work ethic image they had of Hispanics improved significantly. There were no significant changes in the image of the proneness toward violence for Hispanics for any of the groups. Hispanic American self-images were relatively favorable but did not change significantly during the decade. The results raise many questions for future research regarding the influence of media images and stereotyping of Hispanic Americans.
Mesenchymal Stem Cells on Plasma-Deposited Acrylic Acid Coatings: An In Vitro Investigation to Improve Biomaterial Performance in Bone Reconstruction
Authors: Mattioli-Belmonte M. , Lucarini G. , Virgili L. , Biagini G. , Detomaso L. , Favia P. , D’Agostino R. , Gristina R. , Gigante A. , Bevilacqua C.
Published: July 2005

In this in vitro investigation of a heterogeneous range of bio-functional and modulatory performances of mesenchymal stem cells (MSCs) grown on two plasma-deposited acrylic acid (pdAA) coatings, which differed in chemical characteristics, a view of their potential utility as hybrid scaffolds for bone tissue engineering was obtained. The in vitro behavior of MSCs was compared to that of MG-63 cells, an osteoblast-like cell line that is commonly used to test biocompatibility of materials intended for bone-tissue interface. The coatings exerted a greater stimulus on MSCs and on MG-63 cells in comparison with control cultures. Both studied coatings exhibited satisfactory compatibility and modulatory effects on MSCs, thus they may be suitable for use in 2D or 3D scaffolds for bone tissue reconstruction.
Preparation of Hydroxypropylcellulose Membranes using Slow Ionotropic Reactions Configured in an Experimental Design
Authors: Pillay Viness , Danckwerts Michael P. , Bhatt Raj , Setshedi Robert , Patel Rupal
Published: July 2005

This study applied a Face-Centered Central Composite Design to prepare various hydroxypropylcellulose (HPC) membranes using slow ionotropic reactions. After the assessment of various salting-out agents, sodium carbonate was selected as the ideal electrolyte capable of inducing sufficient membrane growth. The factors studied included the concentration of hydroxypropylcellulose [HPC] (1-2%w/v), concentration of salt [Salt] (10-20%w/v) and the salting-out reaction time (SORT) (96-144 hours). The experimental and predicted responses in the design included the measurement of the Brinell Hardness Number (BHN), gel thickness, moisture absorption and membrane erosion. Surface morphological examination revealed that the membranes varied from highly porous to closely packed networks. Statistically, the experimental and predicated response values showed no significant differences (p 0.05) based on a one way ANOVA. A significant decrease in BHN was observed as the [HPC] was increased. This was attributed to an increase in the elasticity of the membrane. The increase in moisture absorption was accompanied by an increase in gel thickness and subsequently an increase in membrane erosion around the peripheral areas of the gel structure. In the case of the [Salt], all response values were reduced above 15%w/v, except in the case of the BHN. In the case of SORT, there was a substantial increase in the responses above 120 hours, except once again for BHN. Above 120 hours the matrix became loose due to extensive infiltration and crystallization of salt ions. The interactions plots indicated that the changes among the different factor levels were found to be significant (p 0.05). The average p-values for the changes between levels for each response were: BHN - p 0.035, moisture absorption - p 0.029, gel thickness - p 0.011, and erosion - p 0.042. This technology may be applicable in the development of membrane scaffolds for interconnecting tissues via their role in cell seeding, adhesion and regeneration.
Poly(Ethylene Glycol)-Doxorubicin Conjugates with pH-Controlled Activation
Authors: Pechar Michal , Braunová Alena , Ulbrich Karel , Jelínková Markéta , Ríhová Blanka
Published: July 2005

The synthesis and physico-chemical characterisation of a biodegradable multiblock polymer drug carrier based on poly(ethylene glycol) (PEG) is described. The blocks of PEG ( Mw 2,000) are connected by an enzymatically degradable tripeptide derivative consisting of one lysine and two glutamic acid residues. Doxorubicin (Dox), was attached to the polymer carrier via a hydrazone bond susceptible to acid hydrolysis at pH 5.0. Human immunoglobulin (IgG) was covalently linked to the polymer-Dox conjugate by the reaction of 2-pyridyldisulfanyl groups of the polymer with thiol groups of the antibody modified with 2-iminothiolane. The resulting antibody-polymer-drug conjugates were characterised by size-exclusion chromatography, UV/VIS spectrophotometry, electrophoresis and amino acid analysis. All polymers studied (both with and without IgG) showed high anti-proliferative activity against concanavalin A-stimulated murine splenocytes and various cancer cell lines in vitro. The polymer-Dox conjugate (without IgG) exhibited a significant anti-tumor efficacy against murine EL4 T-cell lymphoma and human colorectal carcinoma SW620 in vivo.
Synthesis, Acid-Base Properties and Preliminary Cell Compatibility Evaluation of Amphoteric Poly(Amido-Hydrazine)s
Authors: Malgesini Beatrice , Ferruti Paolo , Manfredi Amedea , Casolaro Mario , Chiellini Federica
Published: July 2005

Amphoteric poly(amido-hydrazine)s (PAHYs) were obtained by hydrogen-transfer polyaddition of hydrazine, 1,2-dimethylhydrazine and 1,1-dimethylhydrazine to 2,2-bisacrylamidoacetic acid. These polymers were studied for biomedical applications, such as degradability in water solution, acid-base properties, and cell toxicity. They degraded rapidly in aqueous media under physiological conditions, their molecular weight was reduced to about one-fourth, that of the original polymer in less than two days. They exhibited a typical polyelectrolyte behavior with isoelectric points between 4 and 5 and are prevailingly anionic in the blood. In preliminary cell toxicity essays they proved to be remarkably biocompatible, comparable in this respect to amphoteric poly(amido-amine)s (PAAs), and much less toxic than poly-L-lysine and polyethylenimine.
Histological Behavior of HDPE Scaffolds Fabricated by the “Press-and-Baking” Method
Authors: Kwon Jae Hyun , Kim Sang Soo , Kim Byung-Soo , Sung Won Jun , Lee Soo Hong , Lim Jin Ik , Jung Youngmee , Kim Sang-Heon , Kim Soo Hyun , Kim Young Ha
Published: July 2005

High density polyethylene (HDPE) scaffolds were fabricated by a new “Press-and-Baking” method without using solvents. This method involved mixing HDPE and salt particles, then pressing and baking to produce porous scaffolds after the salt was leached out. The HDPE scaffolds from 80wt% salt had strength and flexibility comparable to commercial Medpor HDPE implants. The HDPE scaffolds provided larger and more pores than Medpor. The HDPE scaffolds were oxidized by ozone to investigate the effect of increased hydrophilicity on tissue healing.

The HDPE scaffolds fabricated were implanted subcutaneously into rats for 28 days to evaluate the biocompatibility compared with Medpor. The HDPE scaffolds exhibited suitable tolerance with surrounding tissue. Although the tissue ingrowth in the HDPE scaffolds infiltrated the pores slower, denser tissue formation was organized in the scaffolds, while Medpor allowed tissue to infiltrate more readily into the interconnective pores. These results indicate that the difference in porous structural morphology affects tissue ingrowth. In contrast, the increased hydrophilicity by ozone oxidation had little effect on tissue ingrowth.
The Effects of Leadership and Governance Processes on Member Participation in Community Health Coalitions
Authors: Metzger Maureen E. , Alexander Jeffrey A. , Weiner Bryan J.
Published: July 2005

This study examines the effects of coalition leadership and governance on member participation in voluntary community health coalitions. Path modeling was used to explore how leadership and governance processes in coalitions affect existing member costs, benefits, and levels of participation. It was hypothesized that the effects of coalition decision making and leadership variables would be indirect by working through their effects on participants’ perceived influence over coalition decision making and on overall consensus around the coalition vision. Results of the analysis indicate that open and collaborative decision making and empowering leadership do have indirect, positive effects on the level of participation by way of vision consensus and participation benefits. Participation costs, however, show no significant direct effect on the level of participation. Perceived personal influence appears to be primarily an outcome of participation rather than an antecedent.
Randomized Trial Testing a Worksite Sun Protection Program in an Outdoor Recreation Industry
Authors: Buller David B. , Andersen Peter A. , Walkosz Barbara J. , Scott Michael D. , Cutter Gary R. , Dignan Mark B. , Zarlengo Elizabeth M. , Voeks Jenifer H. , Giese Aimee J.
Published: July 2005

Health communication campaigns intended to reduce chronic and severe exposure to ultraviolet radiation in sunlight and prevent skin cancer are a national priority. Outdoor workers represent an unaddressed, high-risk population. Go Sun Smart (GSS), a worksite sun safety program largely based on the diffusion-of-innovations theory, was evaluated in a pair-matched, group-randomized, pretest-posttest controlled design enrolling employees at 26 ski areas in Western North America. Employees at the intervention ski areas were more aware of GSS (odds ratio [OR] = 8.27, p < .05) and reported less sunburning (adjusted OR = 1.63, p < .05) at posttest than employees at the control areas. A dose response was evident (OR = 1.46, p < .05) with greater observed program implementation associated with fewer sunburns among employees. Program awareness per se was not predictive ( p > .05) of reduced sunburning in a mediational analysis. Analyses of nonrespondents, including intent-to-treat analyses, further supported the success of GSS.
Suntans and Sun Protection in Australian Teen Media: 1999 to 2000
Authors: McDermott Liane J. , Lowe John B. , Stanton Warren R. , Clavarino Alexandra M.
Published: July 2005

In this study, the portrayal of tanned skin and sun protection in magazines, television programs, and movies popular with Australian adolescents were analyzed. Images of models in magazines ( n = 1,791), regular/supporting characters in television programs ( n = 867), and regular/supporting characters in cinema movies ( n = 2,836)for the 12-monthperiod August 1999to July 2000were coded and analyzed. A light tan was the most predominant tan level, and protective clothing was the most common sun protection measure displayed across all forms of media. There were significant associations between gender and tan levels in the television and movie samples. Although it is important to monitor the portrayal of tan levels and sun protection measures in media targeting adolescents, overall, the authors’ findings revealed a media environment generally supportive of sun protection objectives.
Conspiracy Beliefs About Birth Control: Barriers to Pregnancy Prevention Among African Americans of Reproductive Age
Authors: Thorburn Sheryl , Bogart Laura M.
Published: July 2005

This article examines the endorsement of conspiracy beliefs about birth control (e.g., the belief that birth control is a form of Black genocide) and their association with contraceptive attitudes and behavior among African Americans. The authors conducted a telephone survey with a random sample of 500 African Americans (aged 15-44). Many respondents endorsed birth control conspiracy beliefs, including conspiracy beliefs about Black genocide and the safety of contraceptive methods. Stronger conspiracy beliefs predicted more negative attitudes toward contraceptives. In addition, men with stronger contraceptive safety conspiracy beliefs were less likely to be currently using any birth control. Among current birth control users, women with stronger contraceptive safety conspiracy beliefs were less likely to be using contraceptive methods that must be obtained from a health care provider. Results suggest that conspiracy beliefs are a barrier to pregnancy prevention. Findings point to the need for addressing conspiracy beliefs in public health practice.
Historical pragmatism and the internet
Authors: Carey James W.
Published: July 2005

This article argues that the literature describing the internet revolution in the 1990s was characterized by the rhetoric of the technological sublime. This rhetoric suffered from three fatal flaws: (1) it was not sufficiently grounded in the historical development of technology; (2) it viewed the internet in isolation, failing to consider the wider technological context; and (3) it failed to examine the internet in view of the social, economic, religious and political circumstances of its users. Several examples from history are cited, demonstrating that changes in various systems for the production, dissemination and preservation of cultural information both border and deborder the world. The article suggests that if internet researchers take a pragmatic, historically grounded approach, they will discover that the introduction of internet technology can be seen to have similar consequences. While the technology overcomes many boundaries (of space and time, politics and economics), other social borders may be created at the same time. It is easier to see old boundaries coming down than to see new ones being erected. Rather than being swept by utopian or dystopian enthusiasms, the article insists that the really interesting discoveries are to be made in locating the subtle social shifts taking place, relatively unnoticed, as a consequence of technological change.
Siam remapped: cyber-interventions by Thai Women
Authors: Enteen Jillana B.
Published: July 2005

Most representations of Thailand which circulate in the global public sphere portray Thai women in two categories; both instances position them as happily subservient to western men. This article investigates how contributions by Thai women to internet discussions function simultaneously to renegotiate and reinscribe conceptions of nation, gender and community formation. It focuses on the Thai-managed, English language website SiamWEB.org (www.siamweb.org). The existence of this forum enables conversations between visitors that would otherwise not take place, providing a space for Thai women to respond to these dominant images. The article discusses SiamWEB.org’s strategic use of English, the in-process subject-position assumed of participants, and the persistent refusal of accepted conventions circumscribing national membership. Finally, it analyzes visitor responses, concluding that SiamWEB.org ‘remaps’ and redefines participants’ online identities, Thailand’s national borders, and the tenets of national affiliation.
When the ‘information revolution’ and the US security state collide
Authors: Shields Peter
Published: July 2005

For law enforcement agencies, the ‘information revolution’ is eroding their capacity to regulate money laundering, thereby undermining their ability to combat drug trafficking and terrorism. They argue that without enhanced surveillance powers, these problems will be exacerbated. This emphasis on the control problems precipitated by technology distorts our understanding of the relationship between the ‘information revolution’ and money laundering, much of which has been fuelled not by technology but by the dynamic interaction between technology developments and ongoing changes in criminal justice policy and the US state. An alternative narrative is sketched: the escalation of the US’s failed ‘War on Drugs’ has been a key factor driving both money laundering and the proliferation of surveillance countermeasures. In this context, information and communication technologies have been key resources/sites of struggle for both money launderers and law enforcement. The expansion of surveillance powers will do little to curb illicit action. Indeed, the expansion may escalate laundering as well as erode citizens’ privacy. The article suggests that a similar dynamic may be operating in the US state’s ‘New War on Terrorism’.
Online zealotry: la France du peuple virtuel
Authors: Bratten L. Clare
Published: July 2005

The Front National, a far-Right French political party which had long been ostracized and criticized by the mainstream media, was among the first to adopt a presence on the web as a means to publicize its goals. This article outlines the party’s growth, disaffection with traditional media and its online strategy using discursive analysis of the web site over five years. The article analyzes the internet as a site of cultural negotiation between the national discourse governed by dominant political parties and the more marginalized Front National. France, a centralized government, anxious about the cultural imperialism of English, at first resisted the introduction of the internet, but later promoted it to ensure the presence of French content. The Front National contested the more mainstream notions of French citizenship and nationhood and employed the internet as a catalyst and outlet for its ‘counter-knowledge’.
Letters to Sarah: analysis of email responses to an online editorial
Authors: Ogan Christine , Çiçek Filiz , Özakça Muzaffer
Published: July 2005

An editorial opposing the violence being perpetrated on the Palestinians by the Israeli government that was written on the Common Dreams website prompted several hundred email responses to the author. The essay had been reposted to many listservs and other websites around the world. In a case study approach, we track the repostings and qualitatively and quantitatively analyze the responses to that editorial, to determine the nature of the discourse in an electronic environment. The study found that readers of the essay were prompted to write to the author largely when they agreed with her position because of their political or religious views, linked to their own experience or feelings, wished to relate their own personal stories, and when they were male.