bluuebunny/crossref_metadata_2025 huggingface dataset:
Behaviour evolution of automotive connectors
Authors: Abdi R El , Benjemaa N , Beloufa M A
Published: March 2008

Automotive connector ageing has been studied in the literature, but none of these studies is completely satisfactory for finding the relation between the insertion force, the contact surface, and the spring deflection and wear after several insertion phases.

The main objective of this work is to find and establish a correlation between insertion parameters and wear behaviour using numerical and experimental approaches. This study is concerned with automotive connectors made of copper with a tin coating of thickness 2 μm. The evolution of the insertion force, spring deflection, and contact surface versus the insertion—extraction operation number will provide information about the connector wear behaviour. Using a microbalance, the mass of the sample was determined before and after the experimental insertion test, to quantify the mass loss and the wear evolution. In addition, the wear shape was analysed. The connector includes four spring lamellae on each side and the pin has a flat shape. Owing to the friction effect and after several insertion—extraction tests, eight tracks are visible. Using a scanning profilometer, the length, the depth, and the width of the track can be measured.

At the same time, a numerical analysis using the finite element code Ansys is used with an elastoplastic behaviour law to find the fatigue law, to measure the contact surface, and to predict the wearing surface for the materials employed, which can support a long connector use period. The selected assumptions introduced in the numerical modelling lead to a good correlation with the experimental results.
A survey of cooling tower water quality for condenser tube fouling potential
Authors: Zdaniuk G J , Chamra L M , Mago P J
Published: March 2008

Fouling from cooling tower water is a serious problem in both power and refrigeration industries. The effect of fouling on enhanced tubes could be worse than that on smooth tubes because fouling may degrade the superior heat transfer performance by filling the gaps between the roughness elements with foulant. Condensers that use cooling tower water usually experience four different fouling mechanisms: corrosion, scaling, particulate, and biological fouling. Corrosion is prevented with chemical inhibitors, which pacify the piping and protect the metal surfaces. Cooling tower water can also be treated with biocide to prevent biological fouling. Therefore, the current paper addresses scaling and particulate fouling. The paper also establishes a database of water quality based on chemical analysis of samples collected from cooling towers across the country. The objective of the database is to determine water qualities that are typical of those found in actual cooling towers. From chemical analysis, three water qualities were determined: having an average fouling potential, a low fouling potential, and a severe fouling potential. These water qualities can be used in experimental determinations of fouling resistances in augmented tubes.
Aerodynamic effects of blade sweep and skew in low-speed axial flow rotors at the design flow rate: An overview
Authors: Vad J
Published: March 2008

A detailed literature survey is presented herein in order to overview the aerodynamic impact of non-radial blade stacking techniques applied to axial flow fan and compressor rotors. The literature suggests a consensus that forward blade sweep and skew provides a means for the following advantages in the part load operational range of low-speed axial flow turbofan and compressor rotors: improvement of efficiency and performance, and extension of stall-free operating range. However, the published research results are rather diversified regarding the judgment of performance and loss modifying effects of sweep and skew at the design point. The current paper summarizes the major aerodynamic phenomena related to such blade stacking techniques, in order to contribute to a general reasoning of performance and efficiency modification at the design flow rate. Furthermore, it provides guidelines how to consider these phenomena in tailoring the blade geometry for potential efficiency gain and for achievement of the prescribed total pressure rise at the design point. The role of adequate computational fluid dynamics tools was considered in the paper to be essential in evaluation of aerodynamic effects of non-radial blade stacking, as well as in incorporation of sweep and skew in systematic blade design techniques.
The Mystery of Monogamy
Authors: Gould Eric D , Moav Omer , Simhon Avi
Published: March 2008

We examine why developed societies are monogamous while rich men throughout history have typically practiced polygyny. Wealth inequality naturally produces multiple wives for rich men in a standard model of the marriage market. However, we demonstrate that higher female inequality in the marriage market reduces polygyny. Moreover, we show that female inequality increases in the process of development as women are valued more for the quality of their children than for the quantity. Consequently, male inequality generates inequality in the number of wives per man in traditional societies, but manifests itself as inequality in the quality of wives in developed societies. (JEL J12, J16, J24, Z13)
An Equilibrium Model of “Global Imbalances” and Low Interest Rates
Authors: Caballero Ricardo J , Farhi Emmanuel , Gourinchas Pierre-Olivier
Published: March 2008

The sustained rise in US current account deficits, the stubborn decline in long-run real rates, and the rise in US assets in global portfolios appear as anomalies from the perspective of conventional models. This paper rationalizes these facts as an equilibrium outcome when different regions of the world differ in their capacity to generate financial assets from real investments. Extensions of the basic model generate exchange rate and foreign direct investment excess returns broadly consistent with the recent trends in these variables. The framework is flexible enough to shed light on a range of scenarios in a global equilibrium environment. (JEL: E44, F21, F31, F32)
Asymmetric Auctions with Resale
Authors: Hafalir Isa , Krishna Vijay
Published: March 2008

We study first- and second-price auctions with resale in a model with independent private values. With asymmetric bidders, the resulting inefficiencies create a motive for post-auction trade which, in our model, takes place via monopoly pricing—the winner makes a take-it-or-leave-it offer to the loser. We show (a) a first-price auction with resale has a unique monotonic equilibrium; and (b) with resale, the expected revenue from a first-price auction exceeds that from a second-price auction. The inclusion of resale possibilities thus permits a general revenue ranking of the two auctions that is not available when these are excluded. (JEL D44)
Oxophenalenoxyl: Novel stable neutral radicals with a unique spin-delocalized nature depending on topological symmetries and redox states
Authors: Morita Yasushi , Nishida Shinsuke , Kawai Junya , Takui Takeji , Nakasuji Kazuhiro
Published: March 2008

Stable organic open-shell systems have attracted much attention in the field of molecule-based magnetism. We have been exploring novel stable neutral radicals based on a phenalenyl system known as an odd-alternant hydrocarbon π-radical with a highly spin-delocalized nature. Recently, we have designed and synthesized novel oxophenalenoxyl neutral radical systems possessing two oxygen atoms on the phenalenyl skeleton. These systems are unique in comprising some topological isomers depending on the positions of oxygen substituents on the phenalenyl skeleton. The isomers exhibit different topological symmetries of spin density distributions (spin topological symmetry control). In addition, two-stage one-electron reductions of these systems give the corresponding radical dianions, which show remarkably different topological symmetries of a spin-delocalized nature from those of the neutral radical systems (redox-based spin diversity). In this paper, we discuss the unique spin-delocalized nature of 3-, 4-, and 6-oxophenalenoxyl systems in view of the topological symmetry and redox ability, emphasizing the results from the radical dianion of 4-oxophenalenoxyl system from both experimental and theoretical sides.
Perfluoroalkyl-annelated conjugated systems toward n-type organic semiconductors
Authors: Ie Yutaka , Umemoto Yoshikazu , Nitani Masashi , Aso Yoshio
Published: March 2008

The syntheses of perfluoroalkyl-annelated conjugated units: hexafluorocyclopenta[c]thiophene, 4,4-difluoro-4H-cyclopenta[2,1-b:3,4-b']dithiophene, and 6,6,12,12-tetrafluoroindeno[3,2-b]fluorine, and these-containing oligomers have been accomplished. The annelation of the perfluoroalkyl groups effectively lowers the lowest unoccupied molecular orbitral (LUMO) energy levels without disrupting the effective conjugation of the backbones, which was unambiguously clarified by spectroscopic and electrochemical measurements as well as X-ray analysis. The perfluoroalkyl-annelated oligothiophenes exhibited n-type semiconducting behavior with field-effect electron mobility up to 0.018 cm2 V-1 s-1.
Development of a Multiplexed Urine Assay for Prostate Cancer Diagnosis
Authors: Vener Tatiana , Derecho Carlo , Baden Jonathan , Wang Haiying , Rajpurohit Yashoda , Skelton Joanne , Mehrotra Jyoti , Varde Shobha , Chowdary Dondapati , Stallings Walt , Leibovich Bradley , Robin Howard , Pelzer Alexandre , Schäfer Georg , Auprich Marco , Mannweiler Sebastian , Amersdorfer Peter , Mazumder Abhijit
Published: March 2008

Background: Several studies have demonstrated the value of DNA methylation in urine-based assays for prostate cancer diagnosis. However, a multicenter validation with a clinical prototype has not been published.

Methods: We developed a multiplexed, quantitative methylation-specific polymerase chain reaction (MSP) assay consisting of 3 methylation markers, GSTP1, RARB, and APC, and an endogenous control, ACTB, in a closed-tube, homogeneous assay format. We tested this format with urine samples collected after digital rectal examination from 234 patients with prostate-specific antigen (PSA) concentrations ≥2.5 μg/L in 2 independent patient cohorts from 9 clinical sites.

Results: In the first cohort of 121 patients, we demonstrated 55% sensitivity and 80% specificity, with area under the curve (AUC) 0.69. In the second independent cohort of 113 patients, we found a comparable sensitivity of 53% and specificity of 76% (AUC 0.65). In the first cohort, as well as in a combined cohort, the MSP assay in conjunction with total PSA, digital rectal examination status, and age improved the AUC without MSP, although the difference was not statistically significant. Importantly, the GSTP1 cycle threshold value demonstrated a good correlation (R = 0.84) with the number of cores found to contain prostate cancer or premalignant lesions on biopsy. Moreover, samples that exhibited methylation for either GSTP1 or RARB typically contained higher tumor volumes at prostatectomy than those samples that did not exhibit methylation.

Conclusions: These data confirm and extend previously reported studies and demonstrate the performance of a clinical prototype assay that should aid urologists in identifying men who should undergo biopsy.
IRB Member Judgments of Decisional Capacity, Coercion, and Risk in Medical and Psychiatric Studies
Authors: Luebbert Rebecca , Tait Raymond C. , Chibnall John T. , Deshields Teresa L.
Published: March 2008

While individuals with psychiatric illnesses are widely considered a special class of research subjects regarding decisional capacity and coercion vulnerability, those with physical illnesses often are not. IRB members ( N = 127) read vignettes that described clinical research targeting one of two levels of disease severity (high/low) for psychiatric or medical diagnoses. They then rated decisional capacity, coercion, and risks for hypothetical research subjects. IRB members viewed psychiatric subjects as having greater vulnerability to coercion and less decisional capacity than medical subjects, even when medical illness was of a severity likely to engender psychiatric comorbidities. These results suggest that IRB members may inflate the vulnerability and decisional incapacity of psychiatric subjects, while discounting vulnerability and incapacity in medical subjects.
Investigating Perceived Institutional Review Board Quality and Function Using the IRB Researcher Assessment Tool
Authors: Reeser Jonathan C. , Austin Diane M. , Jaros Linda M. , Mukesh Bickol N. , McCarty Catherine A.
Published: March 2008

The institutional review board-researcher assessment tool (IRB-RAT) was designed to assess the relative importance of various factors to the effective functioning of IRBs. We employed the IRB-RAT to gain insight into the ways in which our IRB is perceived to be deficient by those who routinely interact with our Office of Research Integrity and Protections. Respondents ranked qualities thought to be characteristic of an “ideal” IRB and then compared our IRB to that internal standard. We observed that the rate of study participation varied by role. The composite relative ranking of the 45 items that comprise the IRB-RAT differed significantly from the rank order reported by Keith-Spiegel et al. Our data furthermore suggest that role influences scoring of the IRB-RAT ( e.g., investigators awarded our IRB significantly higher scores in several areas than did research coordinators). Additional research is warranted to determine if the observed role-dependent differences in the perceived quality of our IRB simply reflect the local research culture or if they are indicative of a more fundamental and generalizable difference in outlook between investigators and research coordinators.
Opinions of IRB Members and Chairs regarding Investigators' Relationships with Industry
Authors: Weissman Joel S. , Koski Greg , Vogeli Christine , Thiessen Carrie , Campbell Eric G.
Published: March 2008

The effects of conflicts of interest on the conduct of human research have been roundly debated, but less attention has been paid to the role of Institutional Review Boards (IRBs) in their identification and management. Government and private policy recommendations disagree about IRBs' responsibility in this area. A survey focusing on respondents' attitudes and behaviors regarding consideration of investigator and institutional financial relationships with industry when reviewing research protocols was mailed to a random sample of 893 IRB members and 316 IRB chairs at 115 academic institutions (response rates of 67% and 72%, respectively). More than half of IRB members and chairs felt that industry relationships posed a moderate or big problem for research integrity nationally, and about one-third thought such relationships were a problem at their own institution. Approximately two-thirds felt that investigator-industry relationships should be considered when reviewing protocols regardless of whether they are deemed to be conflicts of interest. While more than 90% of IRB members and chairs believed that investigators' relationships should be disclosed to research participants, 61% of members and chairs reported that these relationships were not always disclosed to participants. While more than 80% believed that institutional relationships should be disclosed to research participants, only 39% of members and chairs said this happened all the time. Some beliefs of IRB members and chairs are at odds with recommendations to limit the role of IRBs in the management of potential investigator conflicts. Lack of unambiguous guidelines has led to inconsistent practices among IRBs.
Perceived Benefits in Trauma Research: Examining Methodological and Individual Difference Factors in Responses to Research Participation
Authors: DePrince Anne P. , Chu Ann
Published: March 2008

This study examined methodological and individual difference factors in relation to perceived benefits and cost-benefit ratios among adult participants in trauma-related research. In two samples ( N's = 72 and 118), ethnically-diverse community participants completed trauma-related questionnaires plus an in-depth interview. In separate community ( N = 213) and undergraduate ( N = 130) samples, participants completed trauma-related questionnaires, but no interviews. Participants rated their perceptions of the research process using the Response to Research Participation Questionnaire (RRPQ). Cost-benefit ratios were favorable in all samples. The research procedures (questionnaires only versus questionnaires plus interviews) explained unique variance in RRPQ scale scores and cost-benefit ratios, as did trauma-related distress. Implications of these findings for developing trauma research protocols are discussed.
Children's Perception of Research Participation: Examining Trauma Exposure and Distress
Authors: Chu Ann T. , DePrince Anne P. , Weinzierl Kristin M.
Published: March 2008

Using the reactions to research Participation Questionnaire for Children (RRPQ-C), this study examined perceptions of research participation among 181 school-aged children with and without trauma histories. As part of two larger studies, children completed non-trauma related tasks to assess emotion understanding and cognitive ability. Parents (and not children) reported on children's interpersonal (e.g., sexual abuse, physical abuse, witnessing domestic violence, witnessing community violence) and non-interpersonal (e.g., motor vehicle accidents, medical traumas, natural disasters) trauma exposure. Children's perceptions of costs and benefits of research participation and understanding of informed consent did not vary as a function of trauma exposure. The number of traumatic events experienced was unrelated to children's perceptions. Furthermore, children across trauma-exposure groups generally reported a positive cost-benefit ratio, and understanding of the consent information. Implications of these data are discussed.
Administrators' Perspectives on Ethical Issues in Long-Term Care Research
Authors: Hickman Susan E. , Cartwright Juliana C. , Young Heather M.
Published: March 2008

Ethical issues are a significant potential barrier to much-needed research in long-term care settings. LTC stakeholder perspectives are largely absent from the development of regulation and guidelines. Fifteen long-term care administrators were interviewed as part of a study of ethical issues in community-based, long-term care research. Established qualitative procedures for conducting content analysis were used to organize the data. Findings suggest that existing mechanisms to protect human subjects do not take into account important differences between academic and long-term care settings. The full potential of LTC research will not be realized until supportive processes to enhance human subjects protections are developed in a way that is reflective of the LTC environment.
Places of Memory as a Tool for Education: The “Peace in Four Voices Summer Camps” at Monte Sole
Authors: BAIESI NADIA , GIGLI MARZIA , MONICELLI ELENA , PELLIZZOLI ROBERTA
Published: March 2008

This essay explores how a place of memory can be used as a crucial tool in peace education activities with students from elementary to high school. It draws on the work of the Peace School of Monte Sole and specifically focuses on the “Peace in Four Voices” summer camp, which brings together youth from conflict regions to foster a culture of peace. The camp is a major activity in the Peace School project, since it is from this ten-year-long experience that the idea of a “Peace School” was conceived of and developed.
The Museum as a Democracy-Building Institution: Reflections on the Shared Journeys Program at the Lower East Side Tenement Museum
Authors: RUSSELL-CIARDI MAGGIE
Published: March 2008

The Lower East Side Tenement Museum has embraced the challenge of serving as a democracy-building institution by providing a venue for dialogue about immigration-related issues. It has also, through its Shared Journeys program, involved new immigrants in these dialogues, and so engaged people who are not yet naturalized citizens in the practice of citizenship. In this process, the museum is redefining what it means to be a citizen, and by extension, creating a more inclusive and thus more dynamic democracy.
Activities of Terezín Memorial
Authors: MUNK JAN
Published: March 2008

This article describes the challenges the Terezín Memorial faced commemorating the victims of Nazi persecution under a Communist government that suppressed information about the history of Jews, anti-Semitism, and resistance movements in the Czech Lands. It also describes how the gradual political opening in that region has enabled the Terezín Memorial to raise awareness about the suffering that took place in Terezín in the past, as well as about the disastrous consequences of the suppression of freedom, democracy, and human rights.
Experimental study of air demand in high head gated tunnels
Authors: Safavi K. , Zarrati A. R. , Attari J.
Published: March 2008

In the present work air demand in a gated tunnel with a circular cross-section was studied experimentally. Effects of gate opening, relative depth (i.e. ratio of flow depth to tunnel diameter) and head losses in the air vent, as well as along the air passage from the tunnel outlet, on air demand were studied. It was concluded that when losses in the air vent increase, flow of air begins from the tunnel outlet. A relationship is suggested for the minimum sub-atmospheric pressure after the gate at which air flow starts from the tunnel outlet. Measurements showed that with a relative depth of less than 40%, even when the vent was fully closed, air was supplied from the tunnel outlet. In this condition higher negative pressures were recorded after the gate. The present work revealed the importance of head losses along the air passage in the tunnel as well as the head losses in the air vent on vent air discharge. These factors are not considered in empirical equations for estimation of vent air discharge.
Water services regulation for the urban poor: Zambia
Authors: Kayaga S. , Franceys R.
Published: March 2008

There is rapid urbanisation in developing countries, where UN Habitat estimates that 80% of the world urban population will live by 2030. Urban water utilities are facing a challenge of continuously extending services to the rapidly expanding towns and cities, particularly so when most of the population growth is absorbed by slums, leading to an increasing number of the urban poor. Economic regulation of urban water service providers is therefore necessary to guard the equity principle and promote universal water service coverage that is an overarching target for achievement of UN millennium development goals (MDGs). This paper reports on research carried out in Lusaka, Zambia, one of seven case studies in a global research study on whether the needs of the urban poor have been incorporated, as a primary duty of regulation. The study found that NWASCO, the Zambian regulator, has made commendable progress towards ‘good regulation’ principles of independence, accountability, consistency, transparency, proportionality and equitable targeting of interventions. Clearly, there are good lessons for policy makers in other developing countries to learn from the way regulation structures, systems and procedures were set up in Zambia, and how they have evolved over time. Increased consumer participation will make the regulatory regime more pro-poor.
Critical flow over spillway profiles
Authors: Castro-Orgaz O. , Giráldez J. V. , Ayuso J. L.
Published: March 2008

One of the oldest problems of critical flow in open-channel hydraulics is rise in the channel bottom, which causes a critical flow at the weir crest. Although the classic hydraulic theory for parallel flow shows the usefulness of critical flow leading to unique head–discharge relations over the weir, in practice the parallel flow condition is unreal; theoretical analysis of round-crested weirs is thus restricted to teaching purposes or is used as a rough indication of flow characteristics before using more complete methods. The spillway problem has been treated previously with more laborious methods, either using two-dimensional (2D) hydrodynamic flow nets or accurate physical model experiments. A new extended Bernoulli energy equation, which is valid for moderately curved channel flows, is presented. From this equation, a higher-order critical flow condition suitable for a curved streamline flow has been developed. As a practical application, the flow over spillway profiles used in dam engineering has been studied. The proposed new critical flow theory makes it possible to simulate flow features with a reasonable agreement up to design conditions of the spillway, thus obtaining accurate results in situations in which the velocity is non-uniform, the pressure is non-hydrostatic and conventional critical flow theory is not valid.
Jetting of Structural Casing in Deepwater Environments: Job Design and Operational Practices
Authors: Akers T. J.
Published: March 2008

Structural casing jetting operations have become commonplace in deepwater environments. Having originated in the Gulf of Mexico (GOM), structural casing is now jetted in most deepwater basins in the world. Very little literature has been published regarding jetting practices. The lack of published literature, combined with the complex mechanics and hydraulics of the process and the lack of detailed-soil data at most locations, results in an operation that is heavily dependent on the experience and expertise of the rigsite team. This paper reviews current deepwater structural casing jetting job design and operational practices. Also included are several case histories of jetting failures presented to share learnings with the industry and to stimulate the sharing of learnings and practices.
Effective High-Density Wellbore Cleaning Fluids: Brine-Based and Solids-Free
Authors: Javora Paul H. , Baccigalopi Glenn , Sanford Jack , Cordeddu Cristina , Qu Qi , Poole Gary , Franklin Bernard
Published: March 2008

Displacing drilling mud with clear solids-free completion brine is a critical step during well completion. As we move into deeper waters and drill to deeper depths (greater than 25,000 feet MD), conventional methods and cleaning fluids become a limiting factor in this phase of the operation. Conventional cleaning fluids use fresh water or seawater treated with surfactants to remove wellbore solids and water-wet tubulars. Using low-density cleaning fluids creates a negative differential pressure between the working kill weight fluid and the formation, casing, and cement liners. In many situations, the negative differential pressure cannot be tolerated, and the risk of failure at the liner top, etc., is increased—especially, if the wellbore has not been pressure-integrity tested. Additionally, with increasing rig/spread costs, high pump rates are necessary to decrease the time it takes to perform these operations. The pump rate is indirectly proportional to the pump pressures required. Weighted spacers decrease the overall pressure differential, which allows for higher pumping rates.

To overcome the density limitation of these cleaning fluids, conventional techniques, such as additional hydraulic horsepower, backpressure schedules, the addition of solids to lighter cleaning fluids (e.g., water, seawater), or balancing the weight of the low-density cleaning fluid with a matching higher-density fluid is used. However, each of these "fixes" has inherent limitations and is accompanied with reduced cleanup efficiency. Furthermore, conventional surfactants are not active or effective in high-density brines. New brine-compatible surfactant chemistry and the corresponding balanced-displacement engineering design were developed to overcome limitation of conventional displacement technology.

This paper describes the field applications of new brine-based, high-density, solids-free cleaning fluids in balanced-displacements in deepwater and offshore shelf wells. The new high-density fluids were based on new surfactant technology developed to ensure effective wellbore cleaning, wellbore design parameters, and displacement modeling. In addition, weighted spacers aid in reducing high pump pressures and wellbore pressure differentials. In one case history, a maximum pumping pressure of more than 9,000 psi was expected for conventional water-based displacement but was reduced to a little more than 3,000 psi with the new design. High-density cleaning fluids, with densities up to and greater than 17.5 ppg, have been formulated and used successfully without compromising cleanup efficiency and significantly reducing differential pressures. Results from laboratory development and field applications are presented.
An Examination of the Relationship between Passion and Subjective Well-Being in Older Adults
Authors: Rousseau François L. , Vallerand Robert J.
Published: March 2008

Activity engagement has long been linked to improved subjective well-being (SWB) in old age. However, recent studies testing Vallerand et al.'s (2003) Dualistic Model of Passion suggest that the type of passionate activity that underlies activity engagement might influence the extent to which individuals benefit from an active lifestyle. In the present article we examined the relationship between harmonious and obsessive passionate activities and subjective well-being in older adults. Results showed that harmonious passion, through its influence on positive affect experienced during activity engagement, is associated with increases in SWB, whereas obsessive passion is associated with decreases in SWB. Engagement in passionate activities might be beneficial for older adults when a passionate activity is harmonious, but detrimental when a passionate activity is obsessive.
Perceived Discrimination and Psychological Well-Being: The Mediating and Moderating Role of Sense of Control
Authors: Jang Yuri , Chiriboga David A. , Small Brent J.
Published: March 2008

Being discriminated against is an unpleasant and stressful experience, and its connection to reduced psychological well-being is well-documented. The present study hypothesized that a sense of control would serve as both mediator and moderator in the dynamics of perceived discrimination and psychological well-being. In addition, variations by age, gender, and race in the effects of perceived discrimination were explored. Data from the Midlife Development in the United States (MIDUS) survey ( N = 1,554; age range = 45 to 74) provided supportive evidence for the hypotheses. The relationships between perceived discrimination and positive and negative affect were reduced when sense of control was controlled, demonstrating the role of sense of control as a mediator. The moderating role of sense of control was also supported, but only in the analysis for negative affect: the combination of a discriminatory experience and low sense of control markedly increased negative affect. In addition, age and gender variations were observed: the negative impact of perceived discrimination on psychological well-being was more pronounced among younger adults and females compared to their counterparts. The findings elucidated the mechanisms by which perceived discrimination manifested its psychological outcomes, and suggest ways to reduce adverse consequences associated with discriminatory experiences.
Knowledge, Attitudes, and Experience regarding Hiv/Aids among Older Adult Inner-City Latinos
Authors: Hillman Jennifer
Published: March 2008

Although Latinos, now the largest minority group in the U.S., comprise 13% of the population, they represent 18% of all new HIV and AIDS cases. This disproportionate representation also appears among older adult Latinos. Semi-structured interviews with 45 inner-city Spanish speaking older adult Latinos provide new data regarding HIV/AIDS among this largely ignored but at risk population. Findings indicate that approximately two thirds of the sample ascribed to at least one myth regarding viral transmission (e.g., via mosquito bites; using public toilets) and less than half were aware of age and gender specific risk factors (e.g., increased mortality and side-effects from antiviral medication; greater risk of contracting HIV through intercourse among older women). Women were significantly less likely to have experience with condoms than men, and machismo, lack of perceived risk, and perceived ineffectiveness were identified as potential barriers to condom use. Recommendations are offered for the design of culturally sensitive, primary prevention programs for this older Latino population.
Radio-Adaptive Response to Environmental Exposures at Chernobyl
Authors: Rodgers Brenda E. , Holmes Kristen M.
Published: March 2008

The genetic consequences resulting from environmental exposure to ionizing radiation have a significant impact on both radiation regulatory policies and the comprehension of the human health risks associated with radiation exposure. The primary objectives of the study were to assess 1) genotoxicity of exposure to radiation as a function of absorbed dose and dose rate, and 2) induction of a radio-adaptive response following a priming dose at varying dose rates. Results demonstrated that sub-acute environmental exposures of 10cGy gamma radiation resulted in indistinguishable levels of chromosomal damage as compared to controls. A radio-adaptive response was observed in all experimental groups, exposed to a subsequent acute challenge dose of 1.5 Gy, demonstrating that low dose rates of low energy transfer (LET) radiation are effective in reducing genetic damage from a subsequent acute low-LET radiation exposure. Furthermore, the data presented herein demonstrate a potential beneficial effect of sub-chronic exposure to low levels of low-LET radiation in an environmental setting and do not support the Linear No Threshold (LNT) hypothesis.
Influence of EDTA, carboxylic acids, amino- and hydroxocarboxylic acids and monosaccharides on the generation of arsines in hydride generation atomic absorption spectrometry
Authors: Petrov Panayot , Serafimovska Jožica , Arpadjan Sonja , Tsalev Dimiter , Stafilov Trajče
Published: March 2008

The influence of EDTA, carboxylic acids, amino-and hydroxocarboxylic acids, monosaccharides and humic substances on the generation of arsines in hydride generation atomic absorption spectrometry (HGAAS) was investigated. EDTA (0.02 mol L−1), ascorbic acid (0.02 mol L−1) and glucose or fructose (0.2 mol L−1) are useful additives for levelling sensitivities for As(III), monomethylarsonate (MMA) and dimethylarsinate (DMA). The presence of glycine, malonic, tartaric acids, BICIN and soil humin extracts leads to differences in analytical signal response between these arsenic species. An analytical application to the determination of the sum of As(III), monomethylarsonate (MMA) and dimethylarsinate (DMA) as well as the sum of toxicologically relevant hydride forming arsenic fraction As(III) + As(V) + MMA + DMA in EDTA soil/sediment extracts using continuous flow HGAAS was demonstrated. The limit of detection was 0.2 mg kg−1 As. Within-day and between-day precision were in the range 3–7% and 4–10%, respectively, for arsenic contents of 0.7–25 mg kg−1, with recoveries 95–103%.
Estimation of n-octanol/water partition coefficients of polycyclic aromatic hydrocarbons by quantum chemical descriptors
Authors: Lu Gui-Ning , Tao Xue-Qin , Dang Zhi , Yi Xiao-Yun , Yang Chen
Published: March 2008

Quantitative structure-property relationship (QSPR) modeling is a powerful approach for predicting environmental behavior of organic pollutants with their structure descriptors. This study reports an optimal QSPR model for estimating logarithmic n-octanol/water partition coefficients (log K OW) of polycyclic aromatic hydrocarbons (PAHs). Quantum chemical descriptors computed with density functional theory at B3LYP/6-31G(d) level and partial least squares (PLS) analysis with optimizing procedure were used for generating QSPR models for log K OW of PAHs. The squared correlation coefficient (R 2) of the optimal model was 0.990, and the results of crossvalidation test (Q 2cum=0.976) showed this optimal model had high fitting precision and good predictability. The log K OW values predicted by the optimal model are very close to those observed. The PLS analysis indicated that PAHs with larger electronic spatial extent and lower total energy values tend to be more hydrophobic and lipophilic.
QSAR modeling for lipid peroxidation inhibition potential of flavonoids using topological and structural parameters
Authors: Ray Supratim , Sengupta Chandana , Roy Kunal
Published: March 2008

In the present study, Quantitative Structure-Activity Relationship (QSAR) modeling has been carried out for lipid peroxidation (LPO)-inhibition potential of a set of 27 flavonoids, using structural and topological parameters. For the development of models, three methods were used: (1) stepwise regression, (2) factor analysis followed by multiple linear regressions (FA-MLR) and (3) partial least squares (PLS) analysis. The best equation was obtained from stepwise regression analysis (Q2 = 0.626) considering the leave-oneout prediction statistics.
Motor Learning in Children: Feedback Effects on Skill Acquisition
Authors: Sullivan Katherine J , Kantak Shailesh S , Burtner Patricia A
Published: March 2008

Background and Purpose

Reduced feedback during motor skill practice benefits motor learning. However, it is unknown whether these findings can be applied to motor learning in children, given that children have different information-processing capabilities than adults. The purpose of this study was to determine the effect of different relative frequencies of feedback on skill acquisition in children compared with young adults.

Subjects

The participants were 20 young adults and 20 children.

Methods

All participants practiced 200 trials of a discrete arm movement with specific spatiotemporal parameters. Participants from each group (adults and children) were randomly assigned to either a 100% feedback group or a reduced (62% faded) feedback group. Learning was inferred from the performance on the delayed (24-hour) retention and reacquisition tests.

Results

All participants improved accuracy and consistency across practice trials. During practice, the adults performed with significantly less error than the children. Adults who practiced with reduced feedback performed with increased consistency during the retention test compared with those who practiced with 100% feedback. In contrast, children who received reduced feedback during practice performed with less accuracy and consistency during the retention test than those who received 100% feedback. However, when feedback was reintroduced during the reacquisition test, the children in the reduced feedback group were able to improve their performance comparable to those in the 100% feedback group.

Discussion and Conclusions

During motor learning, children use feedback in a manner different from that of adults. To optimize motor learning, children may require longer periods of practice, with feedback reduced more gradually, compared with young adults.
Muscle Activation During Selected Strength Exercises in Women With Chronic Neck Muscle Pain
Authors: Andersen Lars L , Kjær Michael , Andersen Christoffer H , Hansen Peter B , Zebis Mette K , Hansen Klaus , Sjøgaard Gisela
Published: March 2008

Background and Purpose

Muscle-specific strength training has previously been shown to be effective in the rehabilitation of chronic neck muscle pain in women. The aim of this study was to determine the level of activation of the neck and shoulder muscles using surface electromyography (EMG) during selected strengthening exercises in women undergoing rehabilitation for chronic neck muscle pain (defined as a clinical diagnosis of trapezius myalgia).

Subjects

The subjects were 12 female workers (age=30–60 years) with a clinical diagnosis of trapezius myalgia and a mean baseline pain intensity of 5.6 (range=3–8) on a scale of 0 to 9.

Method

Electromyographic activity in the trapezius and deltoid muscles was measured during the exercises (lateral raises, upright rows, shrugs, one-arm rows, and reverse flys) and normalized to EMG activity recorded during a maximal voluntary static contraction (MVC).

Results

For most exercises, the level of muscle activation was relatively high (>60% of MVC), highlighting the effectiveness and specificity of the respective exercises. For the trapezius muscle, the highest level of muscle activation was found during the shrug (102±11% of MVC), lateral raise (97±6% of MVC), and upright row (85±5% of MVC) exercises, but the latter 2 exercises required smaller training loads (3–10 kg) compared with the shrug exercise (20–30 kg).

Discussion and Conclusion

The lateral raise and upright row may be suitable alternatives to shrugs during rehabilitation of chronic neck muscle pain. Several of the strength exercises had high activation of neck and shoulder muscles in women with chronic neck pain. These exercises can be used equally in the attempt to achieve a beneficial treatment effect on chronic neck muscle pain.
Adolescent ESL Students’ Interpretation and Appreciation of Literary Texts: A Case Study of Multimodality
Authors: Early Margaret , Marshall Sondra
Published: March 2008

Abstract:

This study explores how, using a multimodal approach to integrating language and content teaching, high school students with limited English proficiency can be supported to engage in rich, complex interpretations of literary works in English and to realize their interpretations linguistically in written academic discourse. Findings suggest that a multimodal approach, in combination with cooperative group work and L1 use, has considerable potential in promoting ELL students’ academic success.
Intelligibility, Comprehensibility, and Accentedness of L2 Speech: The Role of Listener Experience and Semantic Context
Authors: Kennedy Sara , Trofimovich Pavel
Published: March 2008

Abstract:

This study investigated how listener experience (extent of previous exposure to non-native speech) and semantic context (degree and type of semantic information available) influence measures of intelligibility, comprehensibility, and accentedness of non-native (L2) speech. Participants were 24 native English-speaking listeners, half experienced and half inexperienced with L2 speech, who transcribed and rated 90 English utterances spoken by six English and six Mandarin speakers. The utterances varied along two dimensions: real-world expectations (true vs. false utterances) and semantic meaningfulness (meaningful vs. meaningless utterances). Listeners with more experience understood more speech from the L1 and L2 speakers than listeners with less experience but did not rate it differently in comprehensibility and accentedness. All listeners understood and rated the utterances from L2 speakers based on the semantic context available: true–false utterances were understood and rated best, meaningless utterances least. These findings have implications for evaluating learner pronunciation and for training learners in successful L2 communication strategies.
Growth factors, stem cells, and stroke
Authors: Kalluri Haviryaji S. G. , Dempsey Robert J.
Published: March 2008

✓ Postischemic neurogenesis has been identified as a compensatory mechanism to repair the damaged brain after stroke. Several factors are released by the ischemic tissue that are responsible for proliferation, differentiation, and migration of neural stem cells. An understanding of their roles may allow future therapies based on treatment with such factors. Although damaged cells release a variety of factors, some of them are stimulatory whereas some are inhibitory for neurogenesis. It is interesting to note that factors like insulin-like growth factor–I can induce proliferation in the presence of fibroblast growth factor–2 (FGF-2), and promote differentiation in the absence of FGF-2. Meanwhile, factors like transforming growth factor–β can induce the differentiation of neurons while inhibiting the proliferation of neural stem cells. Therefore, understanding the role of each factor in the process of neurogenesis will help physicians to enhance the endogenous response and improve the clinical outcome after stroke. In this article the authors discuss the role of growth factors and stem cells following stroke.
Cell replacement therapy for intracerebral hemorrhage
Authors: Andres Robert H. , Guzman Raphael , Ducray Angélique D. , Mordasini Pasquale , Gera Atul , Barth Alain , Widmer Hans R. , Steinberg Gary K.
Published: March 2008

✓ Intracerebral hemorrhage (ICH), for which no effective treatment strategy is currently available, constitutes one of the most devastating forms of stroke. As a result, developing therapeutic options for ICH is of great interest to the medical community. The 3 potential therapies that have the most promise are cell replacement therapy, enhancing endogenous repair mechanisms, and utilizing various neuroprotective drugs. Replacement of damaged cells and restoration of function can be accomplished by transplantation of cells derived from different sources, such as embryonic or somatic stem cells, umbilical cord blood, and genetically modified cell lines. Early experimental data showing the benefits of cell transplantation on functional recovery after ICH have been promising. Nevertheless, several studies have focused on another therapeutic avenue, investigating novel ways to activate and direct endogenous repair mechanisms in the central nervous system, through exposure to specific neuronal growth factors or by inactivating inhibitory molecules. Lastly, neuroprotective drugs may offer an additional tool for improving neuronal survival in the perihematomal area. However, a number of scientific issues must be addressed before these experimental techniques can be translated into clinical therapy. In this review, the authors outline the recent advances in the basic science of treatment strategies for ICH.
Developing cell transplantation for temporal lobe epilepsy
Authors: Richardson R. Mark , Barbaro Nicholas M. , Alvarez-Buylla Arturo , Baraban Scott C.
Published: March 2008

✓ Mesial temporal lobe epilepsy (MTLE) is presumed to develop progressively as a consequence of synaptic reorganization and neuronal loss, although the exact etiology of seizure development is unknown. Nearly 30% of patients with MTLE have disabling seizures despite pharmacological treatment, and the majority of these patients are recommended for resection. The authors review cell transplantation as an alternative approach to the treatment of epilepsy. Recent work in animal models shows that grafted neuronal precursors that differentiate into inhibitory interneurons can increase the level of local inhibition. Grafts of these inhibitory neurons could help restore equilibrium in MTLE. Developing a sound transplantation strategy involves careful consideration of the etiology of MTLE and the expected functional role of transplanted cells. These issues are reviewed, with a focus on those factors most likely to influence clinically applicable results.
Cell therapies for traumatic brain injury
Authors: Harting Matthew T. , Baumgartner James E. , Worth Laura L. , Ewing-Cobbs Linda , Gee Adrian P. , Day Mary-Clare , Cox Charles S.
Published: March 2008

Preliminary discoveries of the efficacy of cell therapy are currently being translated to clinical trials. Whereas a significant amount of work has been focused on cell therapy applications for a wide array of diseases, including cardiac disease, bone disease, hepatic disease, and cancer, there continues to be extraordinary anticipation that stem cells will advance the current therapeutic regimen for acute neurological disease. Traumatic brain injury is a devastating event for which current therapies are limited. In this report the authors discuss the current status of using adult stem cells to treat traumatic brain injury, including the basic cell types and potential mechanisms of action, preclinical data, and the initiation of clinical trials.