bluuebunny/crossref_metadata_2025 huggingface dataset:
Longitudinal Trajectories of Ethnic Identity Among Urban Black and Latino Adolescents
Authors: Pahl Kerstin , Way Niobe
Published: September 2006

The current study modeled developmental trajectories of ethnic identity exploration and affirmation and belonging from middle to late adolescence (ages 15–18) and examined how these trajectories varied according to ethnicity, gender, immigrant status, and perceived level of discrimination. The sample consisted of 135 urban low‐income Black and Latino adolescents (42% male, 34% Black, 66% Latino). Consistent with developmental theory, individual growth modeling identified an average quadratic trajectory of ethnic identity exploration characterized by decelerating levels of exploration after 10th grade. However, ethnicity and perceived discrimination by peers moderated this pattern. No uniform growth pattern in affirmation was found and Black and Latino adolescents displayed equally high levels of affirmation over time.
The Status Model of Racial Identity Development in African American Adolescents: Evidence of Structure, Trajectories, and Well‐Being
Authors: Seaton Eleanor K. , Scottham Krista Maywalt , Sellers Robert M.
Published: September 2006

Although the identity formation model is widely used to assess adolescent ethnic identity development, the model propositions have rarely been tested. The existence of the identity statuses (diffuse, foreclosed, moratorium, achieved), the proposed developmental trajectories, and whether youth in the achieved status report higher levels of psychological well‐being were examined among a longitudinal sample of 224 African American adolescents, aged 11–17. Cluster analyses were used to create 4 identity statuses consistent with the theoretical model at both time points. The findings indicate that some adolescents progressed, while others regressed or remained constant across time periods. Lastly, the results generally support the assumption that individuals in the achieved status had the highest levels of psychological well‐being at both time periods.
Contextual Influences on Latino Adolescent Ethnic Identity and Academic Outcomes
Authors: Supple Andrew J. , Ghazarian Sharon R. , Frabutt James M. , Plunkett Scott W. , Sands Tovah
Published: September 2006

This study examined the association between 3 components of ethnic identity (exploration, resolution, and affirmation) and factors related to family, neighborhood, and individual characteristics. The purpose was to identity factors that are positively associated with adolescent ethnic identity among a sample of 187 Latino adolescents with a mean age of 14.61. The findings suggested that family ethnic socialization was directly associated with exploration and resolution, but not ethnic affirmation. Analyses with moderator variables suggested that associations between family ethnic socialization and ethnic affirmation varied based on parental behaviors and neighborhood characteristics. The results also suggested that ethnic affirmation, but not exploration or resolution, was positively associated with teacher reports of school performance.
Unpacking Immigration in Youths' Academic and Occupational Pathways
Authors: Tseng Vivian
Published: September 2006

This study sought to unpack how immigration is associated with youths' educational choices during the transition to college and adulthood. Surveys and school records were collected on 789 youth (ages 18–25) with Asian Pacific, Latino, African/Afro‐Caribbean, and European backgrounds. The results indicated generational differences in educational choices, such that children of immigrants chose courses of study with higher math and science content than that of their peers with U.S.‐born parents. Mediation analyses indicated that children of immigrants reported higher social and economic aspirations than did their peers, and their economic aspirations accounted for part of the generational difference in educational choices. Generational differences in educational choices were also mediated by verbal achievement test scores and perceived English skills.
The Nature and Correlates of Mexican‐American Adolescents' Time With Parents and Peers
Authors: Updegraff Kimberly A. , McHale Susan M. , Whiteman Shawn D. , Thayer Shawna M. , Crouter Ann C.
Published: September 2006

Drawing on cultural–ecological and person–environment fit perspectives, this study examined links among Mexican‐American adolescents' time with peers and parents, parents' cultural orientations, and adolescents' psychosocial adjustment and cultural orientations. Participants were 492 Mexican‐American adolescents (Ms=15.7 and 12.8 years for older siblings and younger siblings) and their parents in 246 families. Family members described their family relationships, cultural orientations, and psychosocial functioning in home interviews, and time‐use data were collected during a series of nightly phone calls. Mexican‐American adolescents spent the majority of their peer time with Mexican youth. Some support was found for the hypothesis that themismatchbetween parents' cultural orientations and adolescents' peer involvement is linked to adolescents' psychosocial functioning.
African American Racial Identity Across the Lifespan: Identity Status, Identity Content, and Depressive Symptoms
Authors: Yip Tiffany , Seaton Eleanor K. , Sellers Robert M.
Published: September 2006

Cluster analytic methods were used to create 4 theorized ethnic identity statuses (achieved, foreclosed, moratorium, and diffused) among 940 African American adolescents (13–17 years old), college students (18–23 years old), and adults (27–78 years old). Evidence for the existence of 4 identity statuses was found across the 3 age groups. The distribution of individuals differed by age group, with the older participants disproportionately occupying the more mature statuses. Identity status was related to identity content such that achieved individuals reported higher levels of racial centrality and private regard. Finally, there was a significant interaction between developmental age group and identity status for depressive symptoms such that diffused college students reported higher symptoms than achieved college students. No status differences were found for the other 2 age groups.
Race, Ethnicity, and Culture in Child Development: Contemporary Research and Future Directions
Authors: Quintana Stephen M. , Aboud Frances E. , Chao Ruth K. , Contreras‐Grau Josefina , Cross William E. , Hudley Cynthia , Hughes Diane , Liben Lynn S. , Nelson‐Le Gall Sharon , Vietze Deborah L.
Published: September 2006

The editors of this special issue reflect on the current status and future directions of research on race, ethnicity, and culture in child development. Research in the special issue disentangles race, ethnicity, culture, and immigrant status, and identifies mediators of sociocultural variables on developmental outcomes. The special issue includes important research on normal development in context for ethnic and racial minority children, addresses racial and ethnic identity development, and considers intergroup processes. The methodological innovations as well as challenges of current research are highlighted. It is recommended that future research adhere to principles of cultural validity described in the text.
Fiscal Policy and Educational Attainment in the United States: A Generational Accounting Perspective
Authors: CHOJNICKI XAVIER , DOCQUIER FRÉDÉRIC
Published: September 2006

In this paper we investigate the consequences of the rise in educational attainment on US generational accounts. We build on the 1995 existing accounts and disaggregate them per schooling level. Contrary to medium‐ and high‐skill newborns, we show that low‐skill newborns are characterized by negative generational accounts. Compared to the results obtained with the traditional methodology, our baseline forecast is more optimistic. Nevertheless, the rise in educational attainment is not strong enough to restore the generational balance. Balancing the budget requires increasing taxes by 1.2% or reducing transfers by 2.7%. Our results are robust to the main assumptions.
Charter Schools and Urban Regimes in Neoliberal Context: Making Workers and New Spaces in Metropolitan Atlanta
Authors: HANKINS KATHERINE B. , MARTIN DEBORAH G.
Published: September 2006

In this article, we demonstrate the neoliberalism and multiscalar economic perspective of the charter school movement in Atlanta, Georgia, through examination of news articles and editorials about charter schools in the Atlanta Journal‐Constitution from 1998 to 2004. We posit three interrelated dynamics which explain the editorial board’s interest in charter schools as part of a broader urban regime agenda. First, charter schools represent part of a neoliberal shift in education that parallels shifts in urban governance, emphasizing flexibility, public–private partnerships, and ‘market’‐oriented consumer choice and accountability. Second, the newspaper is issuing a challenge to educational structures, to adopt more neoliberal policies and shed a bureaucratic, liberal governance framework. Finally, we find critical evidence that the charter school movement draws on a multiscalar discourse which simultaneously references responsiveness to local, neighborhood needs, and at the same time highlights the economic imperatives of a global, competitive city to differentially skill students/workers in order to capture mobile and fractured (global) capital.
Cell‐matrix biology in vascular tissue engineering
Authors: Stephan Simon , Ball Stephen G. , Williamson Matthew , Bax Daniel V. , Lomas Amanda , Shuttleworth C. Adrian , Kielty Cay M.
Published: September 2006

We are developing biocompatible small‐calibre vascular substitutes based on polymeric scaffolds that incorporate cell‐matrix signals to enhance vascular cell attachment and function. Our graft scaffold comprises an outer electrostatically spun porous polyurethane layer seeded with smooth muscle cells, and a luminal polycaprolactone layer for endothelial cell attachment. Vascular cell adhesion properties of three vascular elastic fibre molecules, tropoelastin, fibrillin‐1 and fibulin‐5, have been defined, and adhesion fragments optimized. These fragments are being used to coat the scaffolds to enhance luminal endothelial cell attachment, and to regulate smooth muscle cell attachment and function. Tropoelastin‐based cell seeding materials are also being developed. In this way, vascular cell‐matrix biology is enhancing graft design.
Factors influencing osteological changes in the hands and fingers of rock climbers
Authors: Sylvester Adam D. , Christensen Angi M. , Kramer Patricia A.
Published: September 2006

This study examines the osteological changes in the hands and fingers of rock climbers that result from intense, long‐term mechanical stress placed on these bones. Specifically, it examines whether rock climbing leads to metacarpal and phalange modelling in the form of increased cortical thickness as well as joint changes associated with osteoarthritis. This study also attempts to identify specific climbing‐related factors that may influence these changes, including climbing intensity and frequency of different styles of climbing. Radiographs of both hands were taken for each participant and were scored for radiographic signs of osteoarthritis using an atlas method. Total width and medullary width were measured directly on radiographs using digital calipers and used to calculate cross‐sectional area and second moment of area based on a ring model. We compared 27 recreational rock climbers and 35 non‐climbers for four measures of bone strength and dimensions (cross‐sectional area, second moment of area, total width and medullary width) and osteoarthritis. A chi‐squared test for independence was used to compare climber and non‐climber osteoarthritis scores. For each measure of bone strength climbers and non‐climbers were compared using a manova test. Significant manova tests were followed by principal components analysis (PCA) and individual anova tests performed on principal components with eigenvalues greater than one. A second PCA was performed on the climber subsample and the first principal component was then used as the dependent variable in linear regression variable selection procedures to determine which climbing‐related variables affect bone thickness. The results suggest that climbers are not at an increased risk of developing osteoarthritis compared with non‐climbers. Climbers, however, do have greater cross‐sectional area as well as second moment of area. Greater total width, but not meduallary width, indicates that additional bone is deposited subperiosteally. The strength of the finger and hand bones are correlated with styles of climbing that emphasize athletic difficulty. Significant predictors include the highest levels achieved in bouldering and sport climbing.
Brain potentials indicate poor preparation for action in schizophrenia
Authors: Reuter Benedikt , Herzog Eva , Endrass Tanja , Kathmann Norbert
Published: September 2006

Impaired antisaccade performance in schizophrenia (SZ) may originate from poor task preparation, suggested by low amplitudes of the contingent negative variation (CNV) before antisaccades. To dissociate components of preparation we measured the CNV in standard pro‐ and antisaccades and a stimulus preceding negativity (SPN) in delayed pro‐ and antisaccades. In healthy controls the SPN had lower amplitudes than the CNV, reflecting mere stimulus expectation in SPN and combined stimulus expectation and action readiness in CNV. SZ patients had lower CNV amplitudes than controls, but there was no reliable indication of a general SPN reduction, suggesting a particular impairment of action readiness. The CNV and SPN amplitudes of controls were larger if tasks had incongruent (anti) compared to congruent (pro) S‐R mappings. This difference was absent in SZ patients, suggesting a failure to activate specific resources for incongruent S‐R mappings.
Masked repetition priming and event‐related brain potentials: A new approach for tracking the time‐course of object perception
Authors: Eddy Marianna , Schmid Annette , Holcomb Phillip J.
Published: September 2006

This study reports a new approach to studying the time‐course of the perceptual processing of objects by combining for the first time the masked repetition priming technique with the recording of event‐related potentials (ERPs). In a semantic categorization task ERPs were recorded to repeated and unrelated target pictures of common objects that were immediately preceded by briefly presented pattern masked prime objects. Three sequential ERP effects were found between 100 and 650 ms post‐target onset. These effects included an early posterior positivity/anterior negativity (N/P190) that was suggested to reflect early feature processing in visual cortex. This early effect was followed by an anterior negativity (N300) that was suggested to reflect processing of object‐specific representations and finally by a widely distributed negativity (N400) that was argued to reflect more domain general semantic processing.
Breaking the silence: Brain–computer interfaces (BCI) for communication and motor control
Authors: Birbaumer Niels
Published: September 2006

Brain–computer interfaces (BCI) allow control of computers or external devices with regulation of brain activity alone. Invasive BCIs, almost exclusively investigated in animal models using implanted electrodes in brain tissue, and noninvasive BCIs using electrophysiological recordings in humans are described. Clinical applications were reserved with few exceptions for the noninvasive approach: communication with the completely paralyzed and locked‐in syndrome with slow cortical potentials, sensorimotor rhythm and P300, and restoration of movement and cortical reorganization in high spinal cord lesions and chronic stroke. It was demonstrated that noninvasive EEG‐based BCIs allow brain‐derived communication in paralyzed and locked‐in patients but not in completely locked‐in patients. At present no firm conclusion about the clinical utility of BCI for the control of voluntary movement can be made. Invasive multielectrode BCIs in otherwise healthy animals allowed execution of reaching, grasping, and force variations based on spike patterns and extracellular field potentials. The newly developed fMRI‐BCIs and NIRS‐BCIs, like EEG BCIs, offer promise for the learned regulation of emotional disorders and also disorders of young children.
The psychosocial stress‐induced increase in salivary alpha‐amylase is independent of saliva flow rate
Authors: Rohleder Nicolas , Wolf Jutta M. , Maldonado Enrique F. , Kirschbaum Clemens
Published: September 2006

The stress response of salivary alpha‐amylase (sAA) has been suggested as an index for sympathetic nervous system activation. However, concurrent inhibition of the parasympathetic nervous system is discussed as a confounder due to suppression of saliva flow rate. Here we set out to test the influence of stress‐induced changes in flow rate on sAA secretion. Twenty‐six subjects underwent the Trier Social Stress Test and a control condition. Saliva was sampled by passive drooling or salivettes. Saliva flow rate, sAA levels and output, salivary cortisol, and heart rate variability were measured. Flow rate increased only when sampled by passive drooling. Stress‐induced increases in amylase levels were correlated with increases of amylase output but not with flow rate. Results indicate that flow rate is not a confounder of stress‐induced sAA activation and suggest that valid measurements of sAA can be obtained by salivettes without the need for assessment of flow rate.
Acute cortisol administration reduces subjective fatigue in healthy women
Authors: Tops Mattie , Van Peer Jacobien M. , Wijers Albertus A. , Korf Jakob
Published: September 2006

Treatment with cortisol has been found to decrease fatigue and increase feelings of vigor in both patients and healthy male subjects. We obtained self‐reports of mood before 35 mg cortisol or placebo ingestion, 70 min later, and after the healthy female subjects performed cognitive tasks for 1 h in a double‐blind within‐subject study. Cortisol decreased fatigue, increased vigor, and tended to decrease tension. Effects on fatigue were largest after task performance, when fatigue had increased, suggesting that improvement of fatigue by cortisol is observed when subjects are fatigued. This is the first study to demonstrate improvements in fatigue in healthy female subjects; this is particularly relevant because of the high prevalence of hypocortisolimic fatigue syndromes in women and recent evidence that many psychiatric disorders may involve stress‐induced hypocortisolemia that is responsive to cortisol replacement.
Gamma band activity and its synchronization reflect the dysfunctional emotional processing in alexithymic persons
Authors: Matsumoto Atsushi , Ichikawa Yoko , Kanayama Noriaki , Ohira Hideki , Iidaka Tetsuya
Published: September 2006

In the present study, we investigated the gamma band response and its phase synchrony between electrodes in alexithymia, which is characterized by a disability in identifying and describing feelings. Individuals with high and low alexithymia scores were selected according to the scores on the 20‐item Toronto Alexithymia Scale. EEG was recorded from alexithymic and nonalexithymic persons viewing emotionally negative or neutral stimuli. Nonalexithymic persons exhibited increased gamma band power and phase synchronization at the 400–450‐ms time window when processing emotionally negative stimuli. Neither enhanced gamma band power nor phase synchronization was observed in alexithymic persons in the negative emotion condition. These results suggest that gamma band activity reflects emotional processing, and alexithymic persons may have a deficit in communication between brain regions or in the utilization of memory or emotional information during the processing of emotional stimuli.
Recovery of plant DNA using a reciprocating saw and silica‐based columns
Authors: ALEXANDER PATRICK J. , RAJANIKANTH GOVINDARAJALU , BACON CHRISTINE D. , BAILEY C. DONOVAN
Published: September 2006

The time needed for hand grinding and the cost of commercially available extraction kits remain to be the major limitations in plant DNA extraction for many researchers. We present inexpensive techniques for (i) simultaneously machine grinding large numbers of plant samples for DNA extraction using a commercially available reciprocating saw; and (ii) DNA recovery using silica column‐based extractions similar to that used in some commercially available kits. Used together, these allow for the rapid recovery of plant DNA at relatively low cost. Furthermore, these methods appear to be widely applicable within plants with good yields recovered in test extractions across major plant groups (ferns, gymnosperms, monocots and eudicots).
Utilization of Infertility Services: How Much Does Money Matter?
Authors: Farley Ordovensky Staniec J. , Webb Natalie J.
Published: September 2006

Objective. To estimate the effects of financial access and other individual characteristics on the likelihood that a woman pursues infertility treatment and the choice of treatment type.

Data Source/Study Setting. The 1995 National Survey of Family Growth.

Study Design. We use a binomial logit model to estimate the effects of financial access and individual characteristics on the likelihood that a woman pursues infertility treatment. We then use a multinomial logit model to estimate the differential effects of these variables across treatment types.

Data Collection/Extraction Method. This study analyzes the subset of 1,210 women who meet the definition of infertile or subfecund from the 1995 National Survey of Family Growth.

Principal Findings. We find that income, insurance coverage, age, and parity (number of previous births) all significantly affect the probability of seeking infertility treatment; however, the effect of these variables on choice of treatment type varies significantly. Neither income nor insurance influences the probability of seeking advice, a relatively low cost, low yield treatment. At the other end of the spectrum, the choice to pursue assisted reproductive technologies (ARTs)—a much more expensive but potentially more productive option—is highly influenced by income, but merely having private insurance has no significant effect. In the middle of the spectrum are treatment options such as testing, surgery, and medications, for which “financial access” increases their probability of selection.

Conclusions. Our results illustrate that for the sample of infertile of subfecund women of childbearing age studied, and considering their options, financial access to infertility treatment does matter.
Nurse Staffing Levels and Medicaid Reimbursement Rates in Nursing Facilities
Authors: Harrington Charlene , Swan James H. , Carrillo Helen
Published: September 2006

Objective. To examine the relationship between nursing staffing levels in U.S. nursing homes and state Medicaid reimbursement rates.

Data Sources. Facility staffing, characteristics, and case‐mix data were from the federal On‐Line Survey Certification and Reporting (OSCAR) system and other data were from public sources.

Study Design. Ordinary least squares and two‐stage least squares regression analyses were used to separately examine the relationship between registered nurse (RN) and total nursing hours in all U.S. nursing homes in 2002, with two endogenous variables: Medicaid reimbursement rates and resident case mix.

Principal Findings. RN hours and total nursing hours were endogenous with Medicaid reimbursement rates and resident case mix. As expected, Medicaid nursing home reimbursement rates were positively related to both RN and total nursing hours. Resident case mix was a positive predictor of RN hours and a negative predictor of total nursing hours. Higher state minimum RN staffing standards was a positive predictor of RN and total nursing hours while for‐profit facilities and the percent of Medicaid residents were negative predictors.

Conclusions. To increase staffing levels, average Medicaid reimbursement rates would need to be substantially increased while higher state minimum RN staffing standards is a stronger positive predictor of RN and total nursing hours.
Primary Care Practice Organization Influences Colorectal Cancer Screening Performance
Authors: Yano Elizabeth M. , Soban Lynn M. , Parkerton Patricia H. , Etzioni David A.
Published: September 2006

Objective. To identify primary care practice characteristics associated with colorectal cancer (CRC) screening performance, controlling for patient‐level factors.

Data Sources/Study Setting. Primary care director survey (1999–2000) of 155 VA primary care clinics linked with 38,818 eligible patients' sociodemographics, utilization, and CRC screening experience using centralized administrative and chart‐review data (2001).

Study Design. Practices were characterized by degrees of centralization (e.g., authority over operations, staffing, outside‐practice influence); resources (e.g., sufficiency of nonphysician staffing, space, clinical support arrangements); and complexity (e.g., facility size, academic status, managed care penetration), adjusting for patient‐level covariates and contextual factors.

Data Collection/Extraction Methods. Chart‐based evidence of CRC screening through direct colonoscopy, sigmoidoscopy, or consecutive fecal occult blood tests, eliminating cases with documented histories of CRC, polyps, or inflammatory bowel disease.

Principal Findings. After adjusting for sociodemographic characteristics and health care utilization, patients were significantly more likely to be screened for CRC if their primary care practices had greater autonomy over the internal structure of care delivery (p<.04), more clinical support arrangements (p<.03), and smaller size (p<.001).

Conclusions. Deficits in primary care clinical support arrangements and local autonomy over operational management and referral procedures are associated with significantly lower CRC screening performance. Competition with hospital resource demands may impinge on the degree of internal organization of their affiliated primary care practices.
Measuring Organizational Attributes of Primary Care Practices: Development of a New Instrument
Authors: Ohman‐Strickland Pamela A. , John Orzano A. , Nutting Paul A. , Perry Dickinson W. , Scott‐Cawiezell Jill , Hahn Karissa , Gibel Michelle , Crabtree Benjamin F.
Published: September 2006

Objective. To develop an instrument to measure organizational attributes relevant for family practices using the perspectives of clinicians, nurses, and staff.

Data Sources/Study Setting. Clinicians, nurses, and office staff (n=640) from 51 community family medicine practices.

Design. A survey, designed to measure a practices' internal resources for change, for use in family medicine practices was created by a multidisciplinary panel of experts in primary care research and health care organizational performance. This survey was administered in a cross‐sectional study to a sample of diverse practices participating in an intervention trial. A factor analysis identified groups of questions relating to latent constructs of practices' internal resources for capacity to change. ANOVA methods were used to confirm that the factors differentiated practices.

Data Collection. The survey was administered to all staff from 51 practices.

Principal Findings. The factor analysis resulted in four stable and internally consistent factors. Three of these factors, “communication,”“decision‐making,” and “stress/chaos,” describe resources for change in primary care practices. One factor, labeled “history of change,” may be useful in assessing the success of interventions.

Conclusions. A 21‐item questionnaire can reliably measure four important organizational attributes relevant to family practices. These attributes can be used both as outcome measures as well as important features for targeting system interventions.
Inequalities in Use of Health Services among Jews and Arabs in Israel
Authors: Baron‐Epel Orna , Garty Noga , Green Manfred S.
Published: September 2006

Objectives. To compare the levels of utilization of health services in Jews and Arabs taking into account differences in levels of socioeconomic status (SES) in a country with a National Health Insurance Law (NHIL).

Data Source/Study Setting. A cross‐sectional National Health Interview Survey was carried out in Israel based on a random sample of telephone numbers as part of the EUROHIS project (WHO European Health Interview Survey 2003–2004).

Study Design. A random telephone survey included 9,352 interviews. Questions included use of health care services, health status, and socioeconomic variables.

Principal Findings. After adjusting for sex, age, income, education, marital status, and self‐reported chronic diseases, Arabs more often reported visiting a family physician (odds ratio [OR]=1.56, 95 percent confidence interval [CI]=1.35–1.81) and less often reported visiting a specialist (OR=0.73, 95 percent CI=0.60–0.89) compared with Jews. In addition, the odds ratio for hospitalization was similar among Arabs and Jews (OR=1.16, 95 percent CI=0.97–1.38). SES was associated with utilization of health care services only in the Jewish population.

Conclusions. A different pattern of utilization of health care services was observed in Arabs and Jews. This was not explained by differences in socioeconomic levels. More research is needed regarding the distribution of services between Jews and Arabs.
Insider Trading and Voluntary Disclosures
Authors: CHENG QIANG , LO KIN
Published: September 2006

We hypothesize that insiders strategically choose disclosure policies and the timing of their equity trades to maximize trading profits, subject to the litigation costs associated with disclosure and insider trading. Accounting for endogeneity between disclosures and trading, we find that when managers plan to purchase shares, they increase the number of bad news forecasts to reduce the purchase price. In addition, this relation is stronger for trades initiated by chief executive officers than for those initiated by other executives. Confirming this strategic behavior, we find that managers successfully time their trades around bad news forecasts, buying fewer shares beforehand and more afterwards. We do not find that managers adjust their forecasting activity when they are selling shares, consistent with higher litigation concerns associated with insider sales. Overall, our evidence suggests that insiders do exploit voluntary disclosure opportunities for personal gain, but only selectively, when litigation risk is sufficiently low.
The Extreme Future Stock Returns Following I/B/E/S Earnings Surprises
Authors: DOYLE JEFFREY T. , LUNDHOLM RUSSELL J. , SOLIMAN MARK T.
Published: September 2006

We investigate the stock returns subsequent to quarterly earnings surprises, where the benchmark for an earnings surprise is the consensus analyst forecast. By defining the surprise relative to an analyst forecast rather than a time‐series model of expected earnings, we document returns subsequent to earnings announcements that are much larger, persist for much longer, and are more heavily concentrated in the long portion of the hedge portfolio than shown in previous studies. We show that our results hold after controlling for risk and previously documented anomalies, and are positive for every quarter between 1988 and 2000. Finally, we explore the financial results and information environment of firms with extreme earnings surprises and find that they tend to be “neglected” stocks with relatively high book‐to‐market ratios, low analyst coverage, and high analyst forecast dispersion. In the three subsequent years, firms with extreme positive earnings surprises tend to have persistent earnings surprises in the same direction, strong growth in cash flows and earnings, and large increases in analyst coverage, relative to firms with extreme negative earnings surprises. We also show that the returns to the earnings surprise strategy are highest in the quartile of firms where transaction costs are highest and institutional investor interest is lowest, consistent with the idea that market inefficiencies are more prevalent when frictions make it difficult for large, sophisticated investors to exploit the inefficiencies.
Evaluation of an Osteoporosis Workshop for Women
Authors: Ribeiro Violeta , Blakeley Judith A
Published: September 2006

Osteoporosis is a serious health problem that has reached epidemic proportions among Canadian women. This disease, and its concomitant fractures, places a heavy burden on society in terms of human suffering, loss of productivity, death, and health care costs. In keeping with these concerns, a Canadian community health agency has developed a series of workshops that are designed, in part, to educate women about this disease and to encourage them to take appropriate steps to prevent it or to make informed decisions about its treatment. The present study was designed to evaluate the outcome of one of these workshops.

A semi‐experimental design was used to measure any changes in the participants' knowledge about osteoporosis and their prevention and treatment practices regarding this disease. The results were compared to those of a control group that consisted of members of various branches of the Women's Institute who volunteered to participate in the study.

The findings indicate that the workshop was effective in increasing the participants' level of knowledge on osteoporosis, an increase that was still evident 6 months following the session. The effect of the workshop on the actual preventive and treatment practices of women who attended, however, was limited to a slight increase in the use of hormone replacement therapy (HRT) and calcium intake.
The influence of viscoelastic substances on the corneal endothelial cell population during cataract surgery: a prospective study of cohesive and dispersive viscoelastics
Authors: Storr‐Paulsen Allan , Nørregaard Jens Christian , Farik Ghassan , Tårnhøj Jens
Published: September 2006

Purpose:  To compare the ability of cohesive and dispersive ophthalmic viscoelastic devices (OVDs) to protect the corneal endothelium following in‐the‐bag phacoemulsification with implantation of a foldable posterior chamber intraocular lens (IOL).

Methods:  In a prospective single‐masked randomized study, 60 eyes of 60 cataract patients were assigned to three groups of 20 patients each, according to which OVD was used: Celoftal®, Vitrax® or Healon®. The corneal response to surgery was evaluated by measuring the endothelial cell loss, the variation in mean cell area of the endothelial cells (CV), the frequency of hexagonal cells, and the central corneal thickness. Data were recorded preoperatively and 3 months postoperatively.

Results:  Preoperatively, no significant difference was observed in cell count, CV, hexagonal pattern or pachymetry among groups. Postoperatively, all three groups had a significant decrease in cell count, but the decrease was significantly less in the Vitrax group (6.97%) than in the Celoftal (18.03%) and Healon groups (18.46%). No changes in CV, hexagonality or corneal thickness were observed within any of the three groups or among the groups. There was an equal and significant increase in visual acuity.

Conclusions:  Phacoemulsification with implantation of a posterior chamber lens is known to affect the density and morphology of corneal endothelial cells. Viscoelastics facilitate cataract surgery and protect the corneal endothelium during the procedure. Choosing a dispersive hyaluronate OVD during the phaco procedure may allow for protection of the endothelial cells while suppressing the formation of free radicals. This may be the reason for the superior protective effect on the corneal endothelial cells of Vitrax compared with Celoftal and Healon.
Melatonin decreases nitric oxide production and lipid peroxidation and increases interleukin‐1 beta in the brain of mice infected by the Venezuelan equine encephalomyelitis virus
Authors: Valero Nereida , MarinaEspina Luz , Bonilla Ernesto , Mosquera Jesus
Published: September 2006

Abstract:  Melatonin, a potent antioxidant, has shown to be beneficial in murine Venezuelan equine encephalomyelitis (VEE) virus infection. In addition, melatonin can induces the production of interleukin‐1 beta (IL‐1β), a cytokine capable of inducing increased expression of inducible nitric oxide synthase; the activity of this enzyme is increased in the brain of mice infected with VEE virus. The aim of this study was to determine the effect of VEE virus on the nitric oxide (NO) production, lipid peroxidation and IL‐1β production in the brain and serum of mice infected with VEE virus, and to investigate the modulatory role of melatonin during this viral infection. Mice were infected with 10 LD50 of VEE virus and treated with melatonin (500 μg/kg of body weight) starting 3 days before and continuing for 5 days after virus inoculation. Mice were sacrificed on days 1, 3 and 5 postinfection and brains and blood samples were obtained. NO and IL‐1β production and lipid peroxidation levels were measured in perfused brain homogenates and serum. Increased production of brain nitrite was found on days 1, 3 and 5 postinfection and lipid peroxidation products were increased at day 5. Levels of serum nitrite were found elevated on days 3 and 5 postinfection; however, lipid peroxidation products remained similar to basal levels. Melatonin treatment decreased nitrite concentration in brain and serum of infected mice as well as the lipid peroxidation products in the brain. IL‐1β was found to be increased in the brain and serum of infected animals, and melatonin treatment induced higher levels of this cytokine (brain: about 4‐fold; serum: about 8‐fold). These results may be related to the beneficial effect of melatonin in the VEE experimental disease and address the possible therapeutic potential of the indoleamine in human VEE virus infection.
Antioxidant effects of melatonin in rats during chronic exposure to hyperbaric oxygen
Authors: Mollaoglu Hakan , Topal Turgut , Ozler Mehmet , Uysal Bulent , Reiter Russel J. , Korkmaz Ahmet , Oter Sukru
Published: September 2006

Abstract:  In addition to its beneficial effects, hyperbaric oxygen (HBO) exposure causes some detrimental effects via oxidative stress. Previous experimental studies showed that melatonin is a useful agent to block single session HBO‐induced oxidative stress. In the present study, we investigated the antioxidant effect of exogenously administered as well as endogenously produced melatonin in lung and brain tissues of rats exposed to long term HBO. The HBO procedure was set as daily exposures to 2.5 ATA of oxygen for 1 hr and a total of 10 sessions. Twenty‐eight male Sprague–Dawley rats were divided into four groups as follows: control, daytime HBO, daytime HBO plus melatonin (5 mg/kg), nighttime HBO. Tissue oxidative/antioxidant status was examined by determining the protein carbonyl content as a criteria for oxidative stress and the activities of the antioxidant enzymes, superoxide dismutase (SOD) and glutathione peroxidase (GSH‐Px). HBO exposure for 10 days caused significant increases in protein carbonyl content and SOD levels of lung and brain, but GSH‐Px activities remained unaffected. The increases in protein carbonyls were blocked by exogenously administered melatonin and in part by nighttime exposure to darkness whereas the increase of SOD activity was only impeded by endogenously produced melatonin in brain tissue. Lung SOD activity was augmented by endogenous melatonin. In conclusion, melatonin blocks long‐term HBO‐induced cumulative oxidative stress as indicated changes in protein carbonyls. Both exogenously injected and physiologically secreted melatonin has this potential. The effects of HBO‐exposure and melatonin on the activities of the antioxidative enzymes are less clear.
Induction of Maternal Tolerance to Fetal Alloantigens by RANTES Production
Authors: Ramhorst Rosanna , Patel Rahdika , Corigliano Adriana , Etchepareborda Juan José , Fainboim Leonardo , Schust Danny
Published: September 2006

Problem  Previous studies have demonstrated a requirement for RANTES (regulated on activated normal T‐cell expressed, and secreted) at immune privileged sites; we have investigated the role of RANTES in the induction of maternal–fetal tolerance.

Method of study  Endometrial and peripheral T lymphocytes were obtained from women with recurrent pregnancy losses (RPLs) and fertile women. RANTES modulation by progesterone or paternal alloantigens was measured by enzyme‐linked immunosorbent assay or flow cytometry analysis.

Results  Progesterone significantly increased intracellular RANTES expression in CD4+ and CD8+ endometrial T cells. Moreover, alloreactive lymphocytes from RPL patients produced lower RANTES levels when compared with those from fertile women. At the local level, treatment with recombinant RANTES induced a decrease in CCR5 and CXCR4 messenger RNA that correlated with an increase in T‐bet expression. RPL patients and normally fertile women express RANTES similarly, but differ in their patterns of RANTES receptor expression.

Conclusion  RANTES may be implicated in the local induction of a Th1‐type response necessary for successful implantation. Altered response to RANTES stimulation among some RPL patients may be responsible for poor pregnancy outcomes.
Replantation and transplantation following avulsion of two maxillary incisors
Authors: Swiatkowski Wojciech , Rahnama Mansur , Tomaszewski Tomasz
Published: September 2006

Abstract –  Here we describe replantation and transplantation as a treatment conducted in a 16‐year‐old patient following a bicycle accident. An avulsed left central incisor in maxilla was replanted after extra‐oral root canal treatment, and the lost right central incisor of the maxilla was replaced by a left lateral incisor of the mandible in the region of the fracture fissure. Follow‐up examination at 34 months showed validity of treatment, although slight evidence of replacement resorption in the transplanted and replanted teeth was revealed.
Segmental osteotomy to reposition multiple osseointegrated dental implants in the anterior maxilla in a trauma patient
Authors: Kao Shou‐Yen , Fong Jenny Hwai‐Jen , Chou Shen‐Ju , Wu Jen‐Hsien , Tu Hsi‐Fen , Yeung Tze‐Cheung
Published: September 2006

Abstract –  A 16‐year‐old young man had severe loss of alveolar bone and lost four teeth in the anterior maxilla because of traumatic injury in a traffic accident. To overcome the surgically compromised condition for implant rehabilitation, the deficient ridge was augmented by autogenous bone graft from the mandibular symphysis. The augmented ridge had much improvement in width but less in vertical height. Four implants were placed to gain initial osseointegration. Segmental osteotomy was performed to occlusally reposition the implants and bone for 5‐mm in the anterior maxilla. After 2 years of clinical follow‐up, the rehabilitation outcome is satisfactory and stable.
Reattachment of a fractured permanent molar cusp: a 12‐month follow‐up
Authors: Canoglu Harun , Cehreli Zafer C.
Published: September 2006

Abstract –  A posterior crown fracture due to acute trauma is an uncommon type of dental injury. This case report presents combined endodontic‐bioadhesive treatment of a complicated crown fracture of a permanent molar due to a horse riding accident. Endodontic therapy was initiated following surgical removal of the fractured mesiolingual cusp, which was stored frozen until bonding procedures could be carried out. Subgingival and proximal contours of the missing cusp were maintained by an interim glass–ionomer restoration during endodontic therapy. Following root‐canal obturation, the fractured cusp was reattached using a total‐etch adhesive and composite resin system. The patient was recalled at 1, 3, 6 and 12 months, demonstrating excellent clinical and radiographic findings.
Evaluation of dentin permeability after light activated internal dental bleaching
Authors: Carrasco Laise Daniela , Zanello Guerisoli Danilo M. , Pécora Jesus Djalma , Fröner Izabel Cristina
Published: September 2006

Abstract –  The aim of this in vitro study was to assess quantitatively the dentin permeability of human teeth after intracoronal bleaching therapy with 35% hydrogen peroxide activated by LEDs, halogen lamp or using the walking bleach technique. Forty human maxillary central incisors had standard access cavities performed and the cervical thirds of the canals were prepared with Gates‐Glidden drills up to a size 130. Roots were resected between the coronal and middle thirds and the apical portions were discarded. A glass ionomer, 2 mm thick cervical plug was placed inside the canal, at the cement‐enamel junction level. Group I received 35% hydrogen peroxide gel activated by LEDs. Group II was submitted to 35% hydrogen peroxide gel activated by halogen lamp. Group III received 35% hydrogen peroxide gel and the walking bleach technique was followed. Group IV (control) received a dry cotton pellet inside the pulp chamber with temporary restoration. Dentinal permeability was quantified by copper ion penetration. Linear measurements were obtained by analysis of digital images under ×5 magnification. Mean values and SD for the experimental groups were: I, 7.1% (±3.2%); II, 8.4% (±3.0%); III, 9.1% (±3.0%); IV, 1.3% (±2.8%). One‐way anova was used to analyze the results. Results showed an increase of permeability values for groups I, II and III when compared to group IV (control); however, no statistical differences were found between the three tested bleaching techniques. It can be concluded that 35% hydrogen peroxide activated by LED, halogen lamp or used following the walking bleach technique produced similar increase in dentinal permeability.
Staphylococcus aureus protein A binding to von Willebrand factor A1 domain is mediated by conserved IgG binding regions
Authors: O'Seaghdha Maghnus , van Schooten Carina J. , Kerrigan Steven W. , Emsley Jonas , Silverman Gregg J. , Cox Dermot , Lenting Peter J. , Foster Timothy J.
Published: September 2006

Protein A (Spa) is a surface‐associated protein of Staphylococcus aureus best known for its ability to bind to the Fc region of IgG. Spa also binds strongly to the Fab region of the immunoglobulins bearing VH3 heavy chains and to von Willebrand factor (vWF). Previous studies have suggested that the protein A–vWF interaction is important in S. aureus adherence to platelets under conditions of shear stress. We demonstrate that Spa expression is sufficient for adherence of bacteria to immobilized vWF under low fluid shear. The full length recombinant Ig‐binding region of protein A, Spa‐EDABC, fused to glutathione‐S‐transferase (GST), bound recombinant vWF in a dose‐dependent and saturable fashion with half maximal binding of about 30 nm in immunosorbent assays. Full length‐Spa did not bind recombinant vWF A3 domain but displayed binding to recombinant vWF domains A1 and D′‐D3 (half maximal binding at 100 nm and 250 nm, respectively). Each recombinant protein A Ig‐binding domain bound to the A1 domain in a similar manner to the full length‐Spa molecule (half maximal binding 100 nm). Amino acid substitutions were introduced in the GST‐SpaD protein at sites known to be involved in IgG Fc or in VH3 Fab binding. Mutants altered in residues that recognized IgG Fc but not those that recognized VH3 Fab had reduced binding to vWF A1 and D′‐D3. This indicated that both vWF regions recognized a region on helices I and II that overlapped the IgG Fc binding site.