bluuebunny/crossref_metadata_2025 huggingface dataset:
Temporal-Lobe Abnormalities in Thanatophoric Dysplasia
Authors: Knisely A.S. , Ambler Mary W.
Published: March 2008

We identified distinctive and characteristic abnormalities in the hippocampal formations of 4 individuals with thanatophoric dysplasia (TD), one of whom was a fetus of 19 weeks gestational age. Primitive medial fissures in this subject could be identified, but development of the dentate gyrus and organization of the pyramidal layer in the hippocampal formation were abnormal. We infer that temporal-lobe dysmorphogenesis in TD begins between 11.5 weeks gestational age, when hippocampal and fimbriodentate fissure formation takes place, and 13.5 weeks gestational age, when differential proliferation and migration of the cells that form the pyramidal layer and the dentate gyrus takes place. Any etiology proposed for TD must not only account for disordered endochondral and endomembranous bone formation but also explain the origins of early temporal-lobe dysplasia.
Symptomatic Chiari I Malformation in Childhood: A Report of 7 Cases
Authors: Dauser Robert C. , DiPietro Michael A. , Venes Joan L.
Published: March 2008

The Chiari I malformation, once thought to be a disorder of clinical importance only in the teen years and beyond, is now recognized as being significant in the pediatric population as well. We have reviewed 7 cases of Chiari I malformation in children less than 12 years of age. Hydrosyringomyelia was often, but not invariably, an accompanying feature, and this in turn was associated with scoliosis and motor weakness. All patients had posterior fossa and cervical decompression with dural grafting procedures, as well as various types of syringosubarachnoid shunts placed. Intraoperative ultrasound was found to be a valuable surgical adjunct. Symptoms and signs were improved or stabilized in all patients. We feel that this disorder is now more commonly reported in young children because of the increased availability of noninvasive neuroimaging techniques, especially magnetic resonance imaging. Questions are raised as to the actual incidence of undiscovered cases of this disorder in children with commonly seen conditions such as scoliosis.
Planning Ventriculoperitoneal Shunts in Infants and Small Children
Authors: Bridges Nancy , Rifkinson-Mann Stephanie , Handler Michael , Epstein Fred
Published: March 2008

A neurosurgeon planning a ventriculoperitoneal shunt in an infant or child must consider the question of how long a shunt to use in order to compensate for linear growth. Ideally, the system should be just long enough to accomodate the child’s further development without being any longer than necessary. To approach the problem systematically, we used established criteria for prediction of growth to determine the length of shunt ultimately required in adulthood. Our aim was to devise a simple ‘rule of thumb’ method for determining the catheter length necessary for maximal survival of a functioning shunt system.
Management of Craniopharyngiomas in Children
Authors: Tomita Tadanori
Published: March 2008

Craniopharyngiomas are histologically benign neoplasms occurring in the intra- and suprasellar region. Their location and close relation with visual pathways, hypothalamus and major basal vessels may cause difficulty in resecting these tumors without surgical complications. Radiotherapy after limited resection of craniopharyngiomas has been advocated by some investigators while others contend radical resections by means of advanced surgical techniques afford better outcome of patients. Although optimal treatment is yet to be defined, the review of our institutional experience and the critical analysis of the literature show that radiation therapy may be effective but not curative. It is recommended that surgeons should make every effort to effect total excision at the initial operation.
A Technique for Removal of an Adherent Ventricular Catheter
Authors: Chambi Israel , Hendrick Bruce
Published: March 2008

A method of freeing the attachment of the intraventricular catheter to the ventricular ependyma or chorioid plexus is described. A metal ventricular cannula is inserted into the lumen of the ventricular catheter and a cutting current from a unipolar diathermy is applied to the distal end. The cutting effect at the interventricular end of the metal cannula effectively lyses the adhesions and permits safe removal of the ventricular catheter without subsequent bleeding.
Heterogeneity of Nemaline Myopathy
Authors: Shahar Eli , Tervo Raymond C. , Murphy Gordon
Published: March 2008

The marked heterogeneity of nemaline myopathy is again shown in the present series of 13 patients. Most children have a long-standing, mild, and slowly progressing proximal myopathy. Two brothers with extreme weakness died during the neonatal period of respiratory failure representing the X-linked variant. One adult with proximal weakness was also diagnosed as having nemaline myopathy. An unusual course was observed in 2 infants who initially had moderate weakness but subsequently developed severe generalized weakness including respiratory muscles. This led to irreversible respiratory failure requiring continuous ventilatory support for as long as 9 and 15 years, respectively. Although uncommon, the possibility of an imminent respiratory failure in initially weak infants should also be taken into account within the clinical spectrum of nemaline myopathy.
Brain Abscess after Dilatation of Esophageal Stricture
Authors: Lui Tai-Ngar , Lee Shih-Tseng , Chang Chen-Nen , Wang Hui-Shyong
Published: March 2008

Two children, below 15 years of age, developed brain abscesses after esophageal dilation. They were among 40 children treated for supratentorial brain abscesses during the past 10 years. Pus culture of one of the abscesses was peptostreptococcus, which is a common oropharyngeal flora. Clinicians should be aware of this complication since the prognosis is usually satisfactory after prompt treatment.
Radiation Exposure to the Ocular Lens during CT Scanning
Authors: Storrs Bruce B. , Byrd Sharon E.
Published: March 2008

Measurements of radiation exposure during routine CT scanning were found to average 4.2 R at the level of the ocular lens. This data was combined with CT scanning rate data from a sample of 100 patients followed in the myelomeningocele clinic. The number of scans averaged 7.75/patient with a range of 0–34 scans. Cumulative radiation exposure to date ranged from 0 to 143 R. Radiation dosage nomenclature and acceptable limits are discussed and recommendations for reduction of dosage are presented.
Conservative Management of Thrombosed Vein of Galen Malformations
Authors: Zampella Edward J. , Aronin Patricia A. , Odrezin Gregory T. , Duvall Ernest R.
Published: March 2008

Spontaneously thrombosed vein of Galen malformations are rare congenital vascular malformations. Surgical treatment of these lesions based on experience with the management of patent malformations has yielded less than satisfactory results. This report reviews the literature concerning these lesions and details our experience with nonoperative management in 2 patients.
An Unusual Syndrome of Pediatric Brainstem Trauma
Authors: Galyon Daniel D. , Winfield Jeffrey A.
Published: March 2008

We report 2 cases of children who developed a delayed hemiparesis following minor closed head injury with no alteration in consciousness and normal CT studies. MRI showed focal lesions in the ventral pons contralateral to the hemiparesis. Both patients recovered to near normal neurologic function within several days of injury. We postulate a mechanism of injury based on focal contusion of perforating brainstem arteries resulting in the delayed onset of vasospasm.
Benign Ependymomas of the Posterior Fossa in Childhood
Authors: Tomita Tadanori , McLone David G. , Das Lakshmi , Brand William N.
Published: March 2008

A series of 22 infants and children with posterior fossa benign ependymomas treated surgically during the past 12 years is presented. All patients were operated on with posterior fossa craniotomy: visible total resection in 10, subtotal resection in 9, partial resection in 2 and biopsy only in 1. One patient (4.5%) died shortly after surgery. Only 5 patients had documented infiltration of the floor of the fourth ventricle. Postoperative radiotherapy was administered with variable radiation fields and doses. Two out of six patients who had total resection and postoperative radiation therapy did not show recurrence during at least 26 months follow-up period. However, patients with incomplete tumor resection almost invariably developed recurrence. An attempt should be made to remove posterior fossa ependymomas totally at the initial craniotomy. The risk periods for recurrence were between 1 and 2 years after subtotal resection and between 2 and 3 years after total resection. In our experience, gross recurrent tumors appear to be resistant to chemotherapy, and a combination of surgery and radiation therapy does not necessarily prevent recurrence. Newer agents or protocols of adjuvant chemotherapy are needed to explore.
Hyperbaric Oxygen in the Treatment of Elevated Intracranial Pressure after Head Injury
Authors: Brown Jeffrey A. , Preul Mark C. , Taha Assad
Published: March 2008

This study is the first to evaluate the effect of hyperbaric oxygen (HBO) on elevated intracranial pressure (ICP) after severe head injury during documented controlled ventilation, hypocapnea, and minute-by-minute ICP data collection. We studied the effect of HBO at 2 atmospheres absolute (ATA) with 100% O2, on ICP in 2 patients, aged 5 and 21 years. Each patient had diffuse cerebral swelling after blunt trauma and after a gun shot wound, respectively. Both required controlled hyperventilation, osmotic diuretics and ICP monitoring. ICP, mean arterial blood pressure, pulse and atmospheric pressure were recorded at 1-min intervals during 1-hour treatments and for 15 min before and after HBO therapy. Controlled hyperventilation was continued during HBO therapy and PCO, was measured at intervals. Each patient underwent 4 treatments. Data was divided into 5 phases, all at 100% O2: (1) prior to therapy; (2) during pressurization from 1 to 2 ATA; (3) at 2 ATA; (4) during depressurization from 2 to 1 ATA, and (5) after HBO therapy. During pressurization the mean ICP dropped from 13 to 8 Torr, rising to 14 Torr during HBO therapy at 2 ATA, and to 16 Torr during depressurization to 1 atmosphere, then returning to 12 Torr after HBO therapy. We conclude from this preliminary work that HBO may lower ICP in head-injured patients with diffuse cerebral swelling during the first 15 min, or pressurization phase, of therapy. However, rebound elevations in ICP may occur during or after treatment. No lasting effects of treatment were seen after concluding therapy. The effect of HBO on elevated ICP has not yet been clarified, but deserves further careful study in those patients with severe enough injury to require ICP monitoring.
Pediatric Cerebral Abscess
Authors: Moss David , McLone David G. , Arditi Moshe , Yogev Ram
Published: March 2008

Fifty-four consecutive cases of children with cerebral abscess from 1958 to 1987 are reviewed. Their average age was 6.6 years, ranging from 3 days to 19 years. A wide range of organisms and underlying diseases was encountered. The predominant mode of surgical therapy was craniotomy with resection of the abscess. Aspiration and craniotomy with drainage-evacuation were also employed in our series. No underlying disease was found in 10 (19%) of the children. Cyanotic heart disease (CHD) was present in 13 (24%) of the children. Four children had dental abscesses and 1 had otitis media. Seven (13%) children had abscesses secondary to hydrocephalus/shunt infections. Sinusitis and otitis accounted for 5 cases (9%). Four children (7%) had tuberculomas. One abscess was associated with a nasal dermal sinus and one was congenital. Fourteen (26%) patients had negative cultures. Fourteen (26%) abscesses contained streptococci of various types. Staphylococci were found in only 5 (9%) of the abscesses. The congenital abscess was caused by salmonella. Two abscesses (7%) were fungal. Both of these patients died. Six children (11%) were treated without surgical intervention. Three of them died. Forty-eight children had surgical intervention; 12 underwent aspiration, 14 underwent open evacuation of the abscess, and 22 had abscesses resected. Mortality in the aspiration group was twice that of the evacuation or resection group (17, 7 and 9%), respectively). The factor which correlated best with mortality was the patient’s clinical status on admission. The advent of CT scan at our facility improved mortality by facilitating accurate diagnosis and surgical intervention. Overall mortality rates decreased from 31 to 5.7% and surgical mortality fell from 21 to 2.9%.
Gait Analysis of Cerebral Palsy Children before and after Rhizotomy
Authors: Vaughan Christopher L. , Berman Barbara , Staudt Loretta A. , Peacock Warwick J.
Published: March 2008

Over the past decade, selective posterior rhizotomy has been used successfully to reduce spasticity in patients with cerebral palsy. Although clinical evaluation of these patients revealed functional improvement following surgery, more objective analysis of the outcome of this surgery was sought. Kinematic gait analysis of 14 patients with spastic cerebral palsy was performed before and after selective posterior rhizotomy. Measurements of stride length, thigh range of motion, knee range of motion, average speed of walking, and cadence were made. Statistically significant increases in stride length, thigh range and knee range were found. Average speed was increased and cadence was virtually unchanged. These results corroborate clinical findings of improvement in gait of spastic patients with cerebral palsy following selective posterior rhizotomy.
Fetal Neuropathology of Proliferative Vasculopathy and Hydranencephaly-Hydrocephaly with Multiple Limb Pterygia
Authors: Norman Margaret G. , McGillivray Barbara
Published: March 2008

We describe the third family in which fetuses have very narrow cerebral cortical mantles, enlarged ventricles, a peculiar proliferation of cerebral cortical arteries, and hypoplasia of muscle. We describe the youngest fetus yet reported. Previously this condition was interpreted as destructive, perhaps due to infection. We believe it is a primary failure of neuroectodermal cells to form in the ventricular zone with too few resulting cells in cerebral cortex and that the abnormal vascular proliferation is part of the malformation. The involvement of both sexes suggests autosomal recessive inheritance.
Spinal Cord Injury in I-Cell Disease
Authors: Goodman Michael L. , Pang Dachling
Published: March 2008

I-cell disease (ICD), mucolipidosis II, is an autosomal recessive syndrome resulting from defective phosphorylation of acid hydrolases. The diagnosis is made in early childhood and in most cases death occurs by age 5 as a result of cardiorespiratory complications. Pathologic changes are limited to mesenchymal tissues. We treated two children with ICD who developed atlantoaxial dislocation and myelopathy following minor injuries. The first child developed cardiovascular instability with manipulation of the C1 ring at operation, necessitating removal of the arch of C1 and fusion from occiput to C2. The second child was quadriplegic following anatomic reduction of the C1–C2 dislocation at operation during which somatosensory evoked potentials (SSEPs) showed no deleterious change. The atlantoaxial joint is unstable in ICD due to an incompetent transverse ligament infiltrated by storage cells. A cartilaginous, rather than calcified, odontoid process may contribute to the instability. The intraoperative neural injury occurred during attempts to effect anatomical reduction of the chronically dislocated C1–C2 joints and could have resulted from inadvertent trauma to the vertebral arteries and subsequent infarction of the cord. The lack of change in the intraoperative SSEPs was probably due to relative sparing of the posterior columns during the cord injury. We recommend that children with ICD and atlantoaxial instability undergo closed reduction of any existing malalignment followed by posterior C1–C2 fusion as long as the operative risk is not prohibitive. If preopera-tive closed reduction is not readily feasible and the cord is severely compromised, the C1 arch should be removed and the occiput fused to C2. Forceful attempts at anatomical reduction of the chronically dislocated C1–C2 segments should be avoided.
Postradiation Meningioma in a Child
Authors: Balasubramaniam Chidambaram , Armstrong Dawna , Cheek William , Laurent John
Published: March 2008

Tumors caused by radiation treatment are not unkown. They may be benign or malignant. Among these, postradiation meningiomas (PRM) are considered to be a distinct entity. A case of a child who developed a PRM is presented. She received radiation therapy for a presumed thalamic glioma 11 years earlier. An unusual and interesting aspect of this tumor was its attachment to the membrane of the old subdural hematoma, following a shunting procedure. There was no dural attachment. The pathology of PRMs and meningiomas in children are discussed in light of our recent experience.
The Cause of Chiari II Malformation: A Unified Theory
Authors: McLone David G. , Knepper Paul A.
Published: March 2008

The cause of the Chiari II hindbrain deformity in children born with a myelomeningocele can be explained by the lack of distention of the embryonic ventricular system. Defective occlusion and an open neural tube precludes the accumulation of fluid and pressure within the cranial vesicles. This distention is critical to normal brain development. The small posterior fossa, cerebral disorganization, and lückenschädel are the result.
Primary Skin Closure in Large Myelomeningoceles
Authors: Teichgraeber John F. , Riley William B. , Parks Donald H.
Published: March 2008

Numerous reconstructive methods have been described for the soft tissue closure of large myelomeningoceles. Recent advances in techniques of soft tissue expansion provide yet another reconstructive option. Tissue expansion allows for primary closure of the defect with surrounding tissue, resulting in minimal donor site morbidity. This report illustrates the technique of tissue expansion in the closure of a large myelomeningocele.
Pseudocysts of the Abdomen Associated with Ventriculoperitoneal Shunts: A Report of Twelve Cases and a Review of the Literature
Authors: Gaskill Sarah J. , Marlin Arthur E.
Published: March 2008

Shunt complications are reported to occur at a rate of approximately 26%. One of the less frequent but important complications is that of the pseudocyst. Since Harsh’s first mention of a periumbilical cyst associated with a shunt in 1954, 44 cases have been reported in the literature. These are reviewed in addition to 12 cases of our own. From the collected series several features about the etiology and management become apparent. The most common presentation is that of abdominal distension and/or pain rather than shunt malfunction. Diagnosis is then readily made with ultrasonography. Etiologically, it is evident that an inflammatory process is a frequent predisposing factor. In our series 16% had acute infection, 41.6% had a past history of CSF infection (6 months to 6.2 years), and 16% had CNS tumor although tumor cells were not isolated from the peritoneal cysts. Our management of the cyst itself was different from that reported in other series; it was found that the cyst reabsorbed spontaneously without excision or aspiration once the CSF was diverted. The peritoneal cavity could then be used for shunting once the cyst had reabsorbed. This sometimes required conversion to an atrial or pleural shunt before reutilization of the peritoneal cavity. There were no problems with cyst recurrence despite the conversion of 58% of the shunts to ventriculoperitoneal shunts with follow-up ranging from 3 months to 4 years. The mode of management of both the cyst and the hydrocephalus is reviewed.
Anterior Thoracic Extradural Hematoma in a 5-Year-Old Child
Authors: Epstein Nancy E. , Gilder Mark , Black Karen
Published: March 2008

Four hours following a motor vehicle accident, a 5-year-old girl developed a complete motor and sensory paraplegia below the sixth thoracic level (T6). The plain X-rays and MRI scan identified nondisplaced compression fractures of the T3–T6 vertebrae, associated with an anterior T3–T5 epidural hematoma. Following an emergency T3–T6 laminectomy, the sensory findings disappeared, while the motor deficit took 2 weeks to resolve. This case report emphasizes the value of the MRI scan in assessing pediatric spinal trauma, while underscoring the unique characteristics of acute epidural spinal hematomas.
Gamma Knife Radiosurgery for Intracranial Arteriovenous Malformations in Childhood and Adolescence
Authors: Altschuler Eric M. , Lunsford Dade , Coffey Robert J. , Bissonette David J. , Flickinger John C.
Published: March 2008

Eighteen children or adolescents with intracranial arteriovenous malformations (AVM) underwent stereotactic radiosurgery using the first North American gamma knife. This closed-skull, single-treatment therapy, utilizing 201 ionizing beams of γ-irradiation, was used as an alternative to microsurgical removal in these selected patients (aged 34 months to 18 years, mean 12.3 years) beginning in August 1987. No significant perioperative morbidity occurred, and no patient rebled or died in the follow-up interval ranging between 7 and 19 months. Computed tomography (CT) and magnetic resonance imaging (MRI) were used to monitor the response to treatment and to determine when postoperative angiography was indicated. Of seven AVMs examined with cerebral angiography 1 year after treatment, three were completely obliterated; three others were significantly smaller, and their complete obliteration is anticipated by 2 years after treatment. Follow-up CT or MRI confirmed attenuation or signal changes suggestive of edema surrounding the treatment volume in 3 patients; 1 had transient worsening of a preexisting neurological deficit. Although a more long-term perspective is still required for this new technology now available in the United States, we believe that gamma knife stereotactic radiosurgery is a safe and effective method to obliterate AVM deemed too risky for microsurgical removal.
Stereotactic Surgery in Children
Authors: Pattisapu Jogi V. , Walker Marion L. , Heilbrun Peter
Published: March 2008

Stereotactic biopsy has been popularized over the last decade since the advent of newer, more sophisticated instrumentation and technology. However, less than 300 cases of pediatric stereotaxy are recorded in the literature and few reports emphasize the necessary modifications required in children. Sixty-six stereotaxic procedures were performed on 62 children using the Brown-Roberts-Well (BRW) apparatus at our institutions. The mean age was 9.0 years (range 5 months to 18 years). The indication for the technique was diagnostic in 36 cases and therapeutic in 9 cases; location was a factor in 21 children with the lesion involving a ‘deficit-prone’ area of the brain. The BRW technique was applicable in 61 procedures (93%). Inability to enter cysts or biopsy of necrotic tissue and tumor capsule occurred in 5 cases. One patient had a transient increase in cerebral edema, for an overall complication rate of 2%. It appears that the BRW stereotactic technique is equally effective in children and adults and will no doubt play an ever increasing role in the future of pediatric neurosurgery.
On Providing and Enforcing Basic Security
Authors: Mahler Vincent A.
Published: March 2008

Etzioni offers a well-argued critique of recent trends in U.S. foreign policy that the author finds, in the main, persuasive. There are, though, a few points that seem somewhat overstated.
Mediators of the Relationship Between Internalized Oppressions and Lesbian and Bisexual Women's Psychological Distress
Authors: Szymanski Dawn M. , Kashubeck-West Susan
Published: March 2008

This study examined the relationship of internalized oppressions to the psychological distress of 304 lesbian and bisexual women. In addition, it investigated whether self-esteem and social support mediated the relationship between internalized oppressions and mental health. Results indicate that after controlling for education, internalized sexism (IS) and internalized heterosexism/internalized homophobia (IH) are significant predictors of psychological distress and account for 17% of the variance. The interactions between IS and IH are not significant predictors of psychological distress. Furthermore, results reveal that self-esteem and social support fully mediate the relationships between IH and psychological distress. Social support was also found to fully mediate the relationship between IS and psychological distress. However, no support was found for the mediational role of self-esteem in the link between IS and psychological distress. Research and practice implications are discussed.
Testing Latent Mean Differences Between Observed and Unobserved Groups Using Multilevel Factor Mixture Models
Authors: Allua Shane , Stapleton Laura M. , Beretvas S. Natasha
Published: March 2008

When assessing latent mean differences, researchers frequently do not explore possible heterogeneity within their data sets. Sources of differences may be functions of a nested data structure or heterogeneity in the form of unobserved classes of observations defined by a difference in factor means. In this study, the use of multilevel structural equation models in combination with factor mixture models (FMMs) for assessing latent mean differences is discussed. Interpretation of single- and multilevel model parameter estimates when comparing latent means for observed and unobserved groups is demonstrated using a large-scale data set in which students are clustered within schools. Methodological dilemmas are discussed, and directions for future research with respect to multilevel FMMs are suggested.
Item Response Theory–Based Approaches for Computing Minimum Passing Scores From an Angoff-Based Standard-Setting Study
Authors: Ferdous Abdullah A. , Plake Barbara S.
Published: March 2008

Even when the scoring of an examination is based on item response theory (IRT), standard-setting methods seldom use this information directly when determining the minimum passing score (MPS) for an examination from an Angoff-based standard-setting study. Often, when IRT scoring is used, the MPS value for a test is converted to an IRT-based theta ability estimate by using the test characteristic curve. The purpose of this study is to investigate some approaches to determining the MPS from an Angoff-based standard-setting study when the test questions have been calibrated using IRT methods. Although the methods studied appear to converge on the same cut score, the cut scores derived from the IRT-based approaches are all within one standard error of the Angoff-based MPS value.
Note on a Confidence Interval for the Squared Semipartial Correlation Coefficient
Authors: Algina James , Keselman Harvey J. , Penfield Randall J.
Published: March 2008

A squared semipartial correlation coefficient (ΔR2) is the increase in the squared multiple correlation coefficient that occurs when a predictor is added to a multiple regression model. Prior research has shown that coverage probability for a confidence interval constructed by using a modified percentile bootstrap method with ΔR2 was generally good with sample sizes that should not be too challenging for educational and psychological researchers. However, that research was limited to values of Δρ2 = .00 or Δρ2 ≥ .05. The present research investigates coverage probability when .01 ≤ Δρ2 ≤ .04 and shows that the modified percentile bootstrap typically results in coverage probability in the [.925, .975] interval for a 95% confidence interval, provided the sample size is at least 50 if the number of predictors in the model with more predictors (i.e., the full model) is four or smaller, at least 150 if the number of predictors in the full model is five or six, and at least 200 and preferably 250 if the number of predictors in the full model is between seven and nine.
Elevated Temperature Properties of Pinned Composite Lap Joints
Authors: Chang P. , Mouritz A.P. , Cox B.N.
Published: March 2008

Reinforcement in the through-thickness direction with pins improves the elevated temperature strength and damage tolerance of polymer composite joints. The failure modes and ultimate strength are experimentally determined for carbon/epoxy single-lap joints at temperatures between 20 and 250°C. Pinning improves the ultimate strength, elongation-to-failure limit, and work of fracture of the joints over the entire temperature range, by factors that depend on the orientation, volume content and diameter of the pins. The dominant strengthening mechanism at elevated temperature is crack bridging by the pins, which increases the ultimate joint strength by as much as 60%. However, rate-dependent mechanisms increasingly negate the benefit of pins as the temperature rises above approximately 125°C. This threshold temperature is 40°C less than the glass transition temperature for the laminate resin. For tests conducted at a constant rate of increase of load, rate dependence appears as a reduction of the failure load with increasing test temperature. A simple model derived by introducing rate-dependent sliding between the pins and the laminate into a previous model of the mechanics of pin bridging fits the data for strength reduction well, if the sliding rate is assumed to increase exponentially with temperature. The model predicts that the ultimate strength will decrease as the loading rate decreases, for loading that increases linearly with time. The fractional reduction of strength for a given temperature is approximately independent of the pin half-length and area fraction; and greater reduction should occur for larger pin diameter if the pin half-length and volume content are fixed.
Polarization, Horizontal Inequalities and Violent Civil Conflict
Authors: Østby Gudrun
Published: March 2008

Recent large-N studies of civil war conclude that inequality does not increase the risk of violent conflict. This article argues that such conclusions may be premature because these studies, which usually test the conflict potential of `vertical inequality' (i.e. income inequality between individuals), tend to neglect the group aspect of inequality. Case studies suggest that what matters for conflict is a concept closely linked to both economic and ethnic polarization: `horizontal inequalities', or inequalities that coincide with identity-based cleavages. Horizontal inequalities may enhance both grievances and group cohesion among the relatively deprived and thus facilitate mobilization for conflict. This article provides a quantitative test of this argument, exploring whether various forms of polarization and horizontal inequalities affect the probability of civil conflict onset across 36 developing countries in the period 1986—2004. National household data from the Demographic and Health Surveys (DHS) are used to construct measures of ethnic, social and economic polarization, as well as vertical and horizontal inequalities along two dimensions: social and economic. The article also introduces a combined measure of ethnic/socio-economic polarization as an alternative to the horizontal inequality measure. Robust results from panel and cross-section analyses show that social polarization and horizontal social inequality are positively related to conflict outbreak. Variables for purely ethnic polarization, inter-individual inequalities and combined ethnic/socio-economic polarization are not significant.
Polarization and Ethnic Conflict in a Widened Strategic Setting
Authors: Forsberg Erika
Published: March 2008

Ethnic groups and conflicts often transcend country borders, indicating that notions of relative strength and resolve may also surpass such borders. This study focuses on the association between ethnic polarization and conflict in a widened strategic environment, encapsulating each state that experiences ethnic conflict and its neighboring states, and involving contagion processes. Two claims are presented. First, when a state experiences ethnic conflict, neighboring states that are ethnically polarized are more likely to also experience ethnic conflict. Second, when a group involved in ethnic conflict has a kinship tie to a group in a neighboring state, the latter group is increasingly likely to be inspired to challenge the government and end up in ethnic conflict. This should be especially likely if the group resides in a state characterized by ethnic polarization. To evaluate these claims, this article employs logit regression on a global dataset covering the period from 1989 to 2004. The empirical analysis supports the first claim; polarized states are indeed associated with an increased likelihood of contagion processes. The findings also demonstrate that kinship links make contagion more likely; however, this effect is not conditioned by the level of ethnic polarization. The results are robust to a series of alternative specifications. In conclusion, these findings point to the importance of incorporating a widened strategic setting in the analysis when examining the association between ethnic polarization and civil conflict.
Invisible Disability Disclosure in an Employment Interview
Authors: Spirito Dalgin Rebecca , Bellini James
Published: March 2008

This study investigated the impact of disclosure of invisible disabilities (physical and psychiatric) within the employment interview process. Both the type of disability and the extent of disclosure were manipulated in an analogue experimental design. Employers ( N = 60) were exposed to a short interview vignette of a potential candidate and were then asked to make a hiring decision and rate the candidate's employability. The results indicate a significant effect for disability type, with employers rating the candidate with a physical disability significantly higher than the candidate with a psychiatric disability. The findings indicate no significant effects for extent of disclosure; for the interaction of disability and extent of disclosure on employability; and for type of disability, extent of disclosure, and the interaction of disability and extent of disclosure on hiring decision. Implications of the study findings for persons with disabilities and rehabilitation counselors are discussed.
The Impact of Sense of Coherence on Career Thoughts for Individuals With Disabilities
Authors: Lustig Dan C. , Strauser David R.
Published: March 2008

This study examined the effect of sense of coherence on the career thought process. Sense of coherence is the global orientation that the world is comprehensible, manageable, and meaningful. A sample of individuals with disabilities completed the Sense of Coherence Scale and the Career Thoughts Inventory (CTI). Univariate tests indicate a large relationship between Sense of Coherence Scale scores and CTI—total scores and CTI—Decision Making Confusion subscale and CTI—External Conflict subscale scores and a medium relationship between Sense of Coherence Scale scores and CTI—Commitment Anxiety subscale scores. Univariate tests indicate large and medium relationships between Sense of Coherence Scale scores and individual subscale scores. The implications of the study are discussed.
Property Analysis of Denim Fabrics Made on Air-jet Weaving Machine Part II
Authors: Adanur Sabit , Jing Qi
Published: March 2008

In the second part of the study, 3/1 left-hand twill denim fabrics were woven with different filling yarns. The yarn characteristics are correlated to filling tension. Experimental results have shown that yarn count, twist multiplier, hairiness, friction coefficient and other yarn properties have effects on filling tension and filling tension affects the fabric properties. Fabric properties — fabric weight, thickness, air permeability, dimensional stability, abrasion resistance, drapeability, stiffness, wrinkle recovery, tear strength and tensile strength — were tested. It was found that tension had significant effects on some fabric properties. The relationships between fabric properties and filling tension were established.
Dynamic Analysis of Posture Profiles in Quiet Stance on Carpets through Fractional Brownian Motion
Authors: Jianhua Wu  , Ning Pan  , Williams Keith R.
Published: March 2008

In this study we examine the dynamic characteristics of the center of pressure (COP) profiles in quiet stance on various carpets through the framework of fractional Brownian motion. Four different carpets plus the force platform (which served as a control floor) were tested. Six healthy young subjects stood stationary in bare feet on each flooring condition under both eyes-open (EO) and eyes-closed (EC) conditions. A stabilogram diffusion analysis (SDA) was conducted in both anteroposterior and mediolateral directions to extract the dynamic features of the COP profiles. Two approximately linear regions (short-versus long-term regions) were found for all of the flooring conditions in the double logarithmic plot of the mean-square displacements versus time intervals, implying that a two-stage control scheme exists in regulating the posture. In general, a more compliant carpet was found to be associated with a shorter transitional time interval and a lower HL value (Hurst coefficient in the long-term region) under the EO condition, but to be correlated with a higher HS (Hurst coefficient in the short-term region) and a higher HL under the EC condition. While the hard floor of the force platform significantly decreased HL from the EO to the EC conditions, the alteration of visual environments did not substantially influence HL for a compliant carpet.
Marking of Cellulose Yarn by Vinyl Monomer Grafting
Authors: Rosace G. , Massafra M.R.
Published: March 2008

Marking consists of adding a mark on a product for the purpose of its identification. The use of methacrylamide (MAam) and 2-hydroxyethylmetacrylate (HEMA) as markers for cellulose yarn (flax) has been studied. Grafting of a reactive monomer onto cellulose chains has been carried out using a redox system with a chemical initiation technique. The products were characterized by Fourier transform infrared (FT-IR) spectroscopy. HEMA has been chosen due to its more pronounced characteristic band. The major factors affecting HEMA polymerization, including concentration, reaction time and temperature, were studied to establish the optimum grafting conditions. We note that the grafting does not affect the mechanical properties of the yarn.
Investigation of the Seam Performance of PET/Nylon-elastane Woven Fabrics
Authors: Gurarda Ayca
Published: March 2008

This paper presents an experimental study of the seam performance of PET/nylon-elastane woven fabrics. In this study, plain and twill fabrics were woven with three different weft densities. Two different sewing threads were used during the sewing of the fabrics. Therefore, 12 samples having different specifications were obtained. For these fabrics, nylon-elastane air-covered yarn was used as the weft yarn and PET air-covered yarn was used as the warp yarn. Seam strength, seam slippage strength, sewing needle penetration force and seam efficiency were determined for these fabrics for seam performance. The purpose of this study was to identify the suitable sewing conditions in order to achieve good seam performance. This study also investigated the effects of weft density, weave type and sewing thread on the seam performance.
Parent Empowerment and Teacher Professionalism
Authors: Addi-Raccah Audrey , Arviv-Elyashiv Rinate
Published: March 2008

School decentralization, which has reshaped power relations in the educational system, has empowered teachers and parents. Taking Abbott's approach to professions, the authors examine teachers' perceptions of the implications of parents' empowerment for teacher—parent relations. In-depth interviews with homeroom teachers in affluent urban elementary schools revealed that teachers favored parents' involvement but also felt vulnerable to the increasing influence of parents, who scrutinized their work and encroached on their professional domain. To counter this, teachers employed political means: open communication and transparency to boost parents' confidence and trust in their teaching skills or diplomacy to avoid conflicts. This study suggests that, at times of school reform, teachers should develop political tasks to preserve their control over their profession.
The Form and Meaning of Young People's Involvement in Community and Political Work
Authors: Quéniart Anne
Published: March 2008

Why are some young people actively involved in political parties, community groups, or associations? What do they have in common? These are some of the questions that underlie a qualitative research project on involvement carried out among 50 young Canadian activists residing in the province of Quebec. In this article, the author discusses the activist trajectory followed by these young adults and explains the characteristics and meaning of their involvement. For all of them, the cause is more important than the group, as are the more practical aspects of politics. Their viewpoint is similar to that of young people in general who wish to reinforce direct democracy and bring elected officials and citizens closer together. As a whole, the author demonstrates that their involvement practices correspond with a search for ethical consistency (that) aims to give meaning to the values that are adhered to both individually and collectively.
Possible Differential Induction of Phase 2 Enzyme and Antioxidant Pathways by American Ginseng,Panax quinquefolius
Authors: Lee Lawrence S. , Wise Stephen D. , Chan Clark , Parsons Teresa L. , Flexner Charles , Lietman Paul S.
Published: March 2008

Human immunodeficiency virus (HIV)‐infected patients often take herbal medicines, which may interact with antiretrovirals. American ginseng induces phase 2 and antioxidant enzymes in vitro and might increase the clearance of zidovudine and/or enhance antioxidant activity. Ten healthy volunteers received 300 mg of zidovudine orally before and after 2 weeks of treatment with a ginsenoside‐enriched American ginseng extract 200 mg twice daily. This ginseng extract induced the phase 2 enzyme quinone reductase with an average concentration of doubling of enzyme activity of 190 μg/mL. Total ginsenoside content was 8.5 ± 0.5%. Pharmacokinetic profiles of zidovudine and oxidative stress marker concentrations were measured post‐zidovudine dose. American ginseng does not significantly affect the formation clearance of zidovudine to its glucuronide (ratio post‐ to pre‐American ginseng = 1.17; 90% confidence interval: 0.95–1.45;P= .21), total clearance (ratio = 0.97; 0.82–1.14;P= .70), or plasma zidovudine AUC0–8(ratio = 1.03; 0.87–1.21;P= .77). Oxidative stress biomarkers are reduced post‐American ginseng (F2‐isoprostane ratio = 0.79; 0.72–0.86;P< .001; 8‐hydroxy‐deoxyguanosine ratio = 0.74; 0.59–0.92;P= .02). Two weeks of American ginseng does not alter zidovudine pharmacokinetics but reduces oxidative stress markers.
News on the Net
Authors: Melican Debra Burns , Dixon Travis L.
Published: March 2008

An online survey was conducted to assess the perception of credibility of various forms of news media, including Internet news sites associated with traditional forms of media and nontraditional Internet news sites. The survey also explored a possible link between news media credibility and scores on a modern racism scale. This study found that people held differential perceptions of Internet news credibility. Specifically, nontraditional Internet sources were perceived as far less credible than all other news sources. After controlling for a number of factors, the results suggest that those who view nontraditional Internet news sources as more credible than traditional media also score higher on a modern racism scale. The theoretical implications of these findings are discussed, with a focus on the Internet as a safe haven for divergent, even racist, beliefs.
First and Third Person Perceptions on Anti-Drug Ads Among Adolescents
Authors: Cho Hyunyi , Boster Franklin J.
Published: March 2008

The perceived as well as actual (in) effectiveness of anti-drug ads has been prominent in public discourse and concern. Using the third person effect hypothesis, this study examined adolescents' perceptions on the effect of anti-drug ads and the perception's relationship to attitudes and intentions concerning drug use. The results suggested that adolescents estimated the anti-drug ad effect on the basis of their behavioral experience, the self-anchored expectancy of a pro-social media effect: Those who had used drugs anticipated the effect of anti-drug ads to be smaller than those who had not used drugs. The perceived informative realism of anti-drug ads influenced the perceived message quality, which in turn influenced the perceived effect on self. The perceived effect on self was positively associated with anti-drug attitudes and intentions. The implications on future third person perception research and anti-drug campaign efforts are discussed.
Busy Perceivers and Ineffective Suppression Goals: A Critical Role for Distracter Thoughts
Authors: Reich Darcy A. , Mather Robert D.
Published: March 2008

With limited cognitive resources, suppressing thoughts can be ineffective. The detrimental effects of cognitive load on suppression have typically been attributed to increased accessibility of avoided thoughts. However, little research has examined distracter thoughts and their contribution to these effects. In three studies, participants pursued suppression goals related to social judgments (e.g., avoid negative thoughts about a target's performance) with sufficient or diminished cognitive resources. Compared to suppressors not under cognitive load, suppressors under load drew more negative social inferences when pursuing a negative suppression goal and more positive inferences under a positive suppression goal; load did not similarly disrupt a concentration goal (i.e., focus on positive thoughts). Across studies, load reduced high-quality oppositely valenced distracter thoughts, and these distracter thoughts mediated the detrimental effects of load on social inferences. The discussion focuses on mechanisms underlying the effects of load on suppression, implications, and future directions for research on ironic processes.
Making and Unmaking Telepatients
Authors: Mort Maggie , Finch Tracy , May Carl
Published: March 2008

The emergence of the field of health care at a distance, or “telehealth,” has been embedded within discourses of high ambition about health improvement, seamless services, empowerment, and independence for patients. In this article, the authors examine how telehealthcare technologies assume certain forms of patients—or “telepatients”—who can be mobilized and combined with images and artifacts that speak for them in the clinical encounter. Second, a tentative intervention is made in these emerging identities in the form of facilitating some alternative discourses about telehealthcare. The aim is to stimulate debate by presenting and contrasting these different approaches to technology development. Such differences take material and discursive shape in the making and unmaking of telepatients, showing important interferences in the shaping of identity and possibilities for governance and participation.