bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of a classroom program of creative expression workshops for refugee and immigrant children
Authors: Rousseau Cécile , Drapeau Aline , Lacroix Louise , Bagilishya Déogratias , Heusch Nicole
Published: January 2005

Objective:  This evaluative study assessed the effect of a creative expression program designed to prevent emotional and behavioral problems and to enhance self‐esteem in immigrant and refugee children attending multiethnic schools.

Method:  The 12‐week program involved 138 children, aged 7 to 13, registered in both integration classes designed for immigrant children and regular classes at two elementary schools. Pretest and posttest data were collected from the children themselves and from their teacher. Teachers used Achenbach's Teacher's Report Form to assess the emotional and behavioral symptoms of their pupils whereas children self‐reported their symptoms with the Dominic, a computerized questionnaire. Self‐esteem was measured with the Piers‐Harris Self‐Concept Scale administered by interviewers to the children.

Results:  At the end of the program, the children in the experimental groups reported lower mean levels of internalizing and externalizing symptoms and higher mean levels of feelings of popularity and satisfaction than the children in the control groups, when controlling for baseline data. In integration classes, the effect on self‐esteem was especially notable in boys. The intervention's effect on internalizing and externalizing symptoms was not modified by gender, age or fluency in the mainstream language.

Conclusion:  The study provides some evidence that creative workshops in the classroom can have a beneficial effect on the self‐esteem and symptomatology of immigrant and refugee children from various cultures and backgrounds. These quantitative results support previous qualitative analysis showing that the workshops participate in the reconstruction of a meaningful personal world while simultaneously strengthening the link of the child to the group. They also transform the teachers’ perceptions of newcomers by placing an emphasis on their strength and their resilience, while not negating their vulnerabilities.
Policy Analysis for What? The Effectiveness of Nonpartisan Policy Research Organizations
Authors: Hird John A.
Published: January 2005

For the past several decades, scholars have studied the role of policy research in decision making. Depending how “use” is measured, the results have indicated only modest or indirect impacts. This study takes another direction to studying knowledge utilization, comparing the influence of nonpartisan policy research organizations in 19 states on their principal clients: state legislators. Nonpartisan research agencies represent a particularly rigorous test since the literature on knowledge utilization questions whether nonpartisan policy analysis organizations (NPROs) can remain neutral and contribute meaningfully to policymaking. Further, this analysis is comparative across states, studies institutions rather than specific reports or policy domains, and examines multiple types of “use.” Using the results of surveys of both agencies and legislators, the results indicate a strong association between the size and type of policy research organizations and legislators’ assessments of use, even controlling for political and ideological factors. This suggests that policy analysis organizations—even those in a highly politicized environment—have a significant impact on policymaking, mainly by providing information and analysis to decision makers but also in influencing public policy outcomes.
Parent‐Child Interaction and Attention Regulation in Children Born Prematurely
Authors: Davis Deborah Winders , Burns Barbara , Snyder Elizabeth , Dossett Dena , Wilkerson Shirley A.
Published: January 2005

ISSUES AND PURPOSE . The goal of this pilot study was to understand attention behaviors in extremely low‐birth‐weight (ELBW) children within the context of parent‐child interactions and their relation to the child's independent performance.

DESIGN AND METHODS . Parent‐child and child‐alone puzzle matching tasks, demographics, and IQ were measured in a sample of 15 4‐year‐olds who weighed ≤1,000 g at birth and were free from major disability.

RESULTS . A self‐regulated and efficient strategy during the parent‐child puzzle was related to using an efficient strategy when working alone. Attention regulation during the parent‐child puzzle was related to accuracy in the child‐alone task. Parents appeared to be regulating attention appropriately.

PRACTICE IMPLICATIONS . Understanding the mechanisms of attention regulation in ELBW children could lead to specific interventions to support parents in strengthening their children's self‐regulatory functioning.
Antimicrobial activity of five essential oils against origin strains of the Enterobacteriaceae family
Authors: PEÑALVER PEDRO , HUERTA BELÉN , BORGE CARMEN , ASTORGA RAFAEL , ROMERO RAFAEL , PEREA ANSELMO
Published: January 2005

An in vitro assay measuring the antimicrobial activity of essential oils of Coridothymus capitatus (Spanish origanum), Satureja montana, Thymus mastichina (Spanish Origanum majorana), Thymus zygis (Spanish variety of Thymus vulgaris) and Origanum vulgare has been carried out against poultry origin strains of Escherichia coli, Salmonella enteritidis and Salmonella essen, and pig origin strains of enterotoxigenic E. coli (ETEC), Salmonella choleraesuis and Salmonella typhimurium. Using the broth microdilution method, all the essential oils showed an MIC ≥ 2% (v/v) for the two strains of E. coli. The essential oil that showed the highest antimicrobial activity against the four strains of Salmonella was Origanum vulgare (MIC ≤ 1% v/v), followed by Thymus zygis (MIC ≤2% v/v). Thymus mastichina inhibited all the microorganisms at the highest concentration, 4% (v/v), while the rest of the essential oils showed highly variable results. By chemotyping, higher inhibitory capacity was observed in the oils with a higher percentage of phenolic components (carvacrol and thymol) in comparison with oils containing the monoterpenic alcohol linalool. The results of this work confirm the antimicrobial activity of some essential oils, as well as their potential application in the treatment and prevention of poultry and pig diseases caused by salmonella.
Intraoperative frozen section examination of axillary sentinel lymph nodes in breast cancer
Authors: GRABAU D. A. , RANK F. , FRIIS E.
Published: January 2005

The study presents the results from intraoperative frozen section assessment of axillary sentinel lymph nodes (SLNs) in breast cancer. Routine histological frozen sections from one level were used, two sections stained with haematoxylin and eosin. Immunohistochemistry for cytokeratins was applied to the permanent SLN paraffin sections only. Axillary dissection was performed on all SLN‐positive cases regardless of the size of the metastatic deposits. With a detection rate of 83%, 272 patients entered the study over a period of 46 months. A total of 61 cases were SLN positive by frozen section analysis. The paraffin sections gave an additional 23 SLN‐positive cases. The false‐negative rate for frozen sections was then 27% (23/84). Micrometastases were found in 28 of 84 cases, and macrometastases in 56. The false‐negative rate of frozen sections for micrometastases was 71% (20/28), and for macrometastases 5% (3/56). A total of 73% (61/84) of the patients underwent axillary surgery as a one‐step procedure.
Morphologic changes in tubular cells from in situ kidneys following experimental hypothermia and rewarming
Authors: TVEITA T. , JOHANSEN K. , LIEN A. HOVDA , MYKLEBUST R. , LINDAL S.
Published: January 2005

Although renal failure may occur following rewarming from deep accidental hypothermia, this subject has received little attention in experimental hypothermia and clinical case reports. In order to explore the integrity of hypothermic and posthypothermic renal morphology we used an experimental animal model of accidental hypothermia where the heart supports the circulation throughout cooling and rewarming without accompanying cardioplegia or ischemia. Ultrastructural changes in renal tubular cells from three groups of pentobarbital anesthetized Wistar rats: 1) controls (n=6) maintained at 37 °C for 4 h, 2) hypothermic rats (n=6) core‐cooled and maintained at 15–13 °C for 4 h, and 3) rewarmed rats (n=10), were studied as a sensitive indicator of renal damage. Electron micrographs (EM) from hypothermic kidneys showed rounded up mitochondria with loss of contrast. These changes were observed in several though not all of the biopsies, but they were found in all kidneys. Areas exhibiting focal tubular necrosis were seen on most EM from three of these kidneys. EM from rewarmed kidneys showed alterations of mitochondrial ultrastructure with similarities to those observed after hypothermia, but in general the changes were more prominent. Extracellular edema, intracellular edema, swelling of mitochondria, margination of chromatin, necrosis of single tubular cells, and disrupting necrotic debris into tubular lumen could be found in micrographs from 7 of the 10 kidneys examined. Rewarming from experimental hypothermia, without episodes of ischemia or hypoxia, thus induces ultrastructural changes in renal tubular cells similar to changes observed in acute tubular necrosis, associated with renal failure.
Myocardial tissue damage in rabbits injected with group A streptococci, types M1 and M22. Role of bacterial immunoglobulin G‐binding surface proteins
Authors: BUROVA L. A. , NAGORNEV V. A. , PIGAREVSKY P. V. , GLADILINA M. M. , GAVRILOVA E. A. , SELIVERSTOVA V. G. , TOTOLIAN A. A. , THERN A. , SCHALÉN C.
Published: January 2005

Acute rheumatic fever (ARF) and acute poststreptococcal glomerulonephritis (APSGN), two important sequelae of streptococcal throat or skin infections, according to current concepts may be elicited by autoimmune mechanisms due to molecular mimicry between group A streptococci (GAS) and human tissue. In the case of APSGN, however, our experimental data have indicated that GAS immunoglobulin‐binding surface proteins (IgG BPs) might be of pathogenic significance by triggering anti‐IgG production and immune complex formation leading to renal damage. Thus, rabbits injected with IgG‐binding, as opposed to non‐binding, GAS strains were found to develop renal deposition of IgG and complement factor C3 and inflammatory and degenerative glomerular changes resembling the picture seen in APSGN. In the present study, cardiac tissue material from rabbits injected with GAS was investigated. After 8 or more weeks of intravenous (i.v.) injections, minimal changes were seen in those animals receiving an IgG non‐binding GAS strain, type T27, whereas those animals receiving either of two IgG‐binding GAS strains, types M1 or M22, developed strong inflammatory and degenerative myocardial changes accompanied by deposition of IgG and C3. Furthermore, on injecting rabbits with defined mutants of a type M22 strain, the development of myocardial tissue damage proved to be dependent on the presence of streptococcal IgG‐binding activity. Our results demonstrate that myocardial tissue changes may be induced in the rabbit by i.v. injection of whole heat‐killed GAS of at least two M serotypes. Conceivably, induction of immune complexes by bacterial IgG BPs may lead to myocardial deposition of IgG, in turn triggering a series of events, involving the complement system and proinflammatory cytokines, with resulting tissue damage. Though many virulence factors may be involved in the development of ARF and APSGN, and a given GAS strain will never cause both, our results may suggest a new pathogenetic mechanism common to these two major non‐suppurative complications.
Persistent Legionella pneumophila colonization of a hospital water supply: efficacy of control methods and a molecular epidemiological analysis
Authors: PEROLA OUTI , KAUPPINEN JUHA , KUSNETSOV JAANA , KÄRKKÄINEN ULLA‐MAIJA , LÜCK P. CHRISTIAN , KATILA MARJA‐LEENA
Published: January 2005

After a nosocomial outbreak caused by Legionella pneumophila serogroup 5, the hospital water distribution system, which was found to be colonized by L. pneumophila serogroups 5 and 6, was decontaminated by the superheat and flush method and by installing an additional heat‐shock unit in one of the hot water circuits. This unit exposed the recirculated water to a temperature of 80 °C. The efficacy of the decontamination measures was evaluated by monitoring the temperatures and legionella concentrations at different parts of the hot water distribution system. The genetic diversity of the colonizing legionella flora was examined using two genotyping methods: amplified fragment length polymorphism analysis (AFLP) and random amplified polymorphic DNA (RAPD) analysis. Selected serogroup 6 strains were also analyzed by sequence‐based typing (SBT). The results indicated that long‐term eradication of serogroup 5 strains was never achieved. Only one serogroup 6 strain was never isolated after the superheat and flush. In all, according to genetic fingerprints, the diversity of Legionella strains in a hospital water system remains stable over the years regardless of the use of recommended disinfection procedures.
Mutational analysis of the ARAF gene in human cancers
Authors: LEE JONG WOO , SOUNG YOUNG HWA , KIM SU YOUNG , PARK WON SANG , NAM SUK WOO , MIN WOO SUNG , KIM SANG HO , LEE JUNG YOUNG , YOO NAM JIN , LEE SUG HYUNG
Published: January 2005

Deregulation of RAS signal transduction has been implicated in the malignant growth of human cancer cells. The BRAF gene, encoding a RAF family member in the downstream pathway of RAS, is somatically mutated in a number of human cancers, raising the possibility that other RAF family members might be mutated in human cancers. In this study we analyzed the genomic DNAs for the detection of somatic mutations of the ARAF gene in 60 human cancer cell lines and 323 primary human cancer tissues, including colorectal carcinomas, gastric carcinomas, ovarian tumors and acute leukemias. The MOLT‐4 leukemia cell line was found to harbor an ARAF gene mutation resulting in an amino acid substitution (A451T) at the activation segment in the kinase domain of ARAF. In the cancer tissues we could not detect any ARAF gene mutation. Our data indicate that, in contrast to the BRAF gene, the ARAF gene is rarely mutated in human cancers, and suggest that alterations of the RAS pathway by ARAF gene mutation may not play an important role in the pathogenesis of human cancers.
Inflammatory myofibroblastic tumor (inflammatory pseudotumor) of the breast
Authors: ILVAN SENNUR , CELIK VAROL , PAKSOY MELIH , CETINASLAN ILKNUR , CALAY ZERRIN
Published: January 2005

Inflammatory myofibroblastic tumor of the lung has often been reported but extrapulmonary cases are rare. Here we describe a case of inflammatory myofibroblastic tumor of the breast in a 60‐year‐old woman. This is only the eleventh case reported in the English language literature. The patient was free of disease 85 months after surgery.
Review of branch aortic injuries in blunt chest trauma
Authors: Holdgate Anna , Dunlop Sarah
Published: January 2005

Objectives:  To review the incidence, mechanisms of injury, diagnosis and treatment of injuries to the major branches of the thoracic aorta within the thoracic cavity following blunt trauma.

Methods:  Medline, Embase and Cochrane were searched using appropriate key word and MeSH headings. Full text articles were retrieved where there was any information relating to the mechanism of injury, incidence of injury, diagnosis, treatment or outcome in patients with injuries to the brachiocephalic, subclavian or carotid arteries within the thoracic cavity following blunt chest trauma.

Results:  The reported incidence of these injuries varied widely, most injuries were related to rapid deceleration injuries or falls. Diagnosis depends on a high level of clinic suspicion and appropriate investigations include helical CT scanning and arteriography. Treatment options have expanded in recent years with the use of endovascular stents; however, the optimal treatment remains uncertain.

Conclusions:  Aortic branch injuries must be actively excluded in patients with suspicious mechanisms of injury. Guidelines determining appropriate investigative pathways and methods of treatment should be developed at all trauma centres.
Ambulance diversion is not associated with low acuity patients attending Perth metropolitan emergency departments
Authors: Sprivulis Peter , Grainger Stephen , Nagree Yusuf
Published: January 2005

Objective:  To examine the relationship between ambulance diversion and low acuity patient (LAP) attendances to EDs.

Methods:  Comparison of LAP attendance rates at inner metropolitan EDs and outer metropolitan EDs using a previously validated methodology.

Results:  The percentage of LAP attendances was lower at inner metropolitan EDs (11.4%, 95% CI 11.3–11.6) compared to outer metropolitan hospitals (22.9%, 95% CI 22.6–23.2, P < 0.001). The proportion of LAP attendances was slightly higher at both inner and outer metropolitan hospitals after‐hours compared to working hours. Average daily LAP attendances per inner metropolitan hospital (13.4 attendances, 95% CI 13.2–13.6) which averaged 89.2 min of diversion daily (95% CI 88.7–89.7) were lower than at outer metropolitan hospitals (19.3 attendances, 95% CI 19.0–19.6, P < 0.001), which averaged 12.4 min of diversion daily (95% CI 12.1–12.5, P < 0.001).

Conclusions:  Inner metropolitan hospitals experience low LAP attendance rates. Attempts to further reduce LAP attendance rates at Perth inner metropolitan hospitals have limited scope to reduce ambulance diversion.
Management of new onset atrial fibrillation in previously well patients less than 60 years of age
Authors: Taylor David McD , Aggarwal Anuradha , Carter Michael , Garewal Devinder , Hunt David
Published: January 2005

Objective:  This study reviewed the ED management of new onset atrial fibrillation (AF) in previously well patients aged less than 60 years.

Methods:  We undertook a retrospective review of ED patients from 1998 to 2002 inclusive. The main outcome measures were approaches to rate or rhythm control and anticoagulation, the use of echocardiography, the value of diagnostic testing and the frequency of hospital admission.

Results:  Fifty‐two patients were identified. In general, all patients were haemodynamically stable. One patient had mild cardiac failure and one was clinically thyrotoxic. Serum potassium was measured in 51 (98%) patients, magnesium in 23 (44%) and cardiac enzymes in 30 (58%); results were generally unhelpful. Thyroid function tests were carried out in 40 (77%) patients; results were unremarkable except for the clinically thyrotoxic patient. No patient had echocardiography in the ED; however, 6 patients (12%) were later found to have major cardiac abnormalities. Forty‐four (85%) patients received a variety of medications; 37 (71%) received an anti‐arrhythmic and 24 (46%) an antithrombotic. Overall, 17 (33%) patients received theoretically effective therapy for conversion to sinus rhythm. Twenty‐two (42%) patients were admitted to hospital.

Conclusions:  This study reveals variation in the management of acute AF in previously well, haemodynamically stable, young patients. Pathology testing was frequently carried out with a low yield. There were high rates of attempts to cardiovert, use of antithrombotics and of admission to hospital. Although cardioversion attempts appeared to be contrary to existing guidelines, decisions may have been based primarily on patient symptoms. Echocardiography should be considered prior to anti‐arrhythmic therapy.
Recent advances in the neurophysiology of chronic pain
Authors: Baker Kylie
Published: January 2005

The chronic pain syndrome patient has become the ‘leper’ of emergency medicine. There are no emergency medicine guidelines and minimal research into managing this challenging group of patients.

Objective:  To summarize the recent advances in laboratory research into the development of chronic pain that have relevance to emergency management. When the level of supporting evidence is low, it is imperative that emergency physicians understand the physiology that underpins those expert opinions upon which they base their treatment strategies.

Methods:  Literature was searched via Medline, Cochrane, Cinahl, and PsycINFO from 1996 to 2004, under ‘chronic pain and emergency management’. Medline from 1996 was searched for ‘chronic pain and prevention’, ‘chronic pain and emergency’ and ‘chronic pain’. Bibliographies were manually searched for older keynote articles.

Results:  Advances in understanding the biochemical changes of chronic pain are paralleled by lesser known advances in delineation of the corticol processing.

Conclusions:  Drug manipulation causes complex action and reaction in chronic pain. Emergency physicians must also optimize cognitive and behavioural aspects of treatment to successfully manage this systemic disease.
Chronic pain syndromes in the emergency department: Identifying guidelines for management
Authors: Baker Kylie
Published: January 2005

Objectives:  To explore current literature on chronic pain syndromes and develop ED recommendations for the management and minimalization of chronic non‐cancer pain.

Methods:  A focused literature review.

Results:  Chronic pain is a common presentation to the ED but is poorly understood and managed. Research into the psychophysiology of chronic pain shows that there are definite changes in the receptive and processing pathways in patients suffering chronic pain syndromes. Evidence shows the effectiveness of early recognition with multimodal treatment, however high level evidence is lacking. All experts recommend balanced drug therapy, cognitive and behavioural interventions. Certain interventions are appropriate to the ED setting.

Conclusions:  Emergency Medicine lacks a cohesive, informed strategy for management of chronic pain. The proposed guidelines represent the first step toward establishing consistency in the management of patients with chronic pain syndromes. Further work needs to be undertaken at a national level in developing evidence based guidelines.
Duodenal perforation: An interesting case report
Authors: Donald Kirsten J , Doherty Steven R , Shun Albert
Published: January 2005

We describe a young child presenting with vomiting and altered neurological status. An incidental finding of pneumoperitoneum on abdominal X‐ray led to laparotomy and the discovery of a duodenal perforation. We describe the difficulties in making the diagnosis of duodenal perforation in children and some of the factors that led to the delay in diagnosis in this case.
Relative utility of serum troponin and the OESIL score in syncope
Authors: Hing Rosslyn , Harris Roger
Published: January 2005

Objective:  To investigate the utility of both a random troponin T level taken greater than 4 h after a syncopal event and the Osservatorio Epidemiologico sulla Sincope nel Lazio (OESIL) score in predicting outcome post syncope.

Methods:  We prospectively enrolled 113 adult patients who presented to our ED after a syncopal event. Each patient had a troponin T level taken at least 4 h after the event. The relevant history of the syncope, background medical history and ECG were collected at presentation. Patients were followed up via telephone after 3–6 months and medical records were also examined. The OESIL risk score was calculated for each patient and the predictive value of both the troponin T and OESIL score were analysed for their utility post syncope.

Results:  Data were analysed for 100 patients. Twenty percent were believed to have a cardiac cause for their syncope. An elevated troponin T level was found to be highly specific (0.99, 95% confidence interval [CI] 0.96–1.0) for adverse cardiac outcome, but with a very low sensitivity (0.13, 95% CI 0–0.3). The OESIL risk score was found to be predictive of an adverse cardiac outcome (receiver–operating characteristic [ROC] 0.73, 95% CI 0.63–0.84) and return to normal function (ROC 0.74, 95% CI 0.63–0.86).

Conclusions:  A normal serum troponin T has a poor negative predictive value for adverse cardiac outcomes following syncope. A simple risk stratification system, such as the OESIL score, can predict those patients most at risk after a syncopal episode.
Elastoplastic Modeling of Metal Matrix Composites Containing Randomly Located and Oriented Spheroidal Particles
Authors: Sun L. Z. , Ju J. W.
Published: January 2005

Micromechanics-based effective elastic and plastic formulations of metal matrix composites (MMCs) containing randomly located and randomly oriented particles are developed. The averaging process over all orientations upon three elastic governing equations for aligned particle-reinforced MMCs is performed to obtain the explicit formulation of effective elastic stiffness of MMCs with randomly oriented particles. The effects of volume fraction of particles and particle shape on the overall elastic constants are studied. Comparisons with the Hashin-Shtrikman bounds and Ponte Castaneda-Willis bounds show that the present effective elastic formulation does not violate the variational bounds. Good agreement with experimental elastic stiffness data is also illustrated. Furthermore, the orientational averaging procedure is employed to derive the overall elastoplastic yield function for the MMCs. Elastoplastic constitutive relations for the composites are constructed on the basis of the derived composite yield function. The stress-strain responses of MMCs under the axisymmetric loading are also investigated in detail. Finally, elastoplastic comparisons with the experimental data for SiCp/Al composites are performed to illustrate the capability of the proposed formulation.
A Correspondence Principle for Scission-Induced Stress Relaxation in Elastomeric Components
Authors: Wineman Alan , Shaw John
Published: January 2005

A method is presented for calculating the stress relaxation due to scission in elastomeric components that operate at a fixed deformation while at an elevated temperature. A relationship is established between stresses at different temperatures that is called the correspondence principle for scission/healing materials. Two examples involving cylinders illustrate its use. The first example involves combined tension-torsion, for which an axial force-twisting moment relation is derived, that might be useful in experimental studies to assess the applicability of the correspondence principle. The second example provides a criterion for estimating the lifetime of an annular seal.
End Effects in Prestrained Plates Under Compression
Authors: Karp B.
Published: January 2005

The decay of end perturbations imposed on a rectangular plate subjected to compression is investigated in the context of plane-strain incremental finite elasticity. A separation of variables in the eigenfunction formulation is used for the perturbed field within the plate. Numerical results for the leading decay exponent are given for four rubbers: three compressible and one incompressible. It was found that the lowest decay rate is governed by a symmetric field that exhibits different patterns of dependence on the prestrain for compressible and for nearly incompressible solids. Compressible solids are characterized by low sensitivity of the decay rate to prestrain level up to moderate compression, beyond which an abrupt decrease of decay rate brings it to zero. Nearly incompressible solids, on the other hand, expose a different pattern involving interchange of modes with no decrease of decay rate to zero. Both patterns show that the decay rate obtained from linear elastic analysis can be considered as a good approximation for a prebuckled, slightly compressed plate, which is long enough in comparison to its width. Along with decaying modes, the eigenfunction expansion generates a nondecaying antisymmetric mode corresponding to buckling of the plate. Asymptotic expansion of that nondecaying mode near the stress free state predicts buckling according to the classical Euler formula. A consistent interpretation of end effects in the presence of a nondecaying mode is given.
Three-Dimensional Electroelastic Analysis of a Piezoelectric Material With a Penny-Shaped Dielectric Crack
Authors: Li Xian-Fang , Lee Kang Yong
Published: January 2005

Previous studies assumed that a crack is either impermeable or permeable, which are actually two limiting cases of a dielectric crack. This paper considers the electroelastic problem of a three-dimensional transversely isotropic piezoelectric material with a penny-shaped dielectric crack perpendicular to the poling axis. Using electric boundary conditions controlled by the boundaries of an opening crack, the electric displacements at the crack surfaces are determined. The Hankel transform technique is employed to reduce the considered problem to dual integral equations. By solving resulting equations, the results are presented for the case of remote uniform loading, and explicit expressions for the electroelastic field at any point in the entire piezoelectric body are given in terms of elementary functions. Moreover, the distribution of asymptotic field around the crack front and field intensity factors are determined. Numerical results for a cracked PZT-5H ceramic are evaluated to examine the influence of the dielectric permittivity of the crack interior on the field intensity factors, indicating that the electric boundary conditions at the crack surfaces play an important role in determining electroelastic field induced by a crack, and that the results are overestimated for an impermeable crack, and underestimated for a permeable crack.
Stochastic Stability of Coupled Oscillators in Resonance: A Perturbation Approach
Authors: Namachchivaya N. Sri , Van Roessel H. J.
Published: January 2005

A perturbation approach is used to obtain an approximation for the moment Lyapunov exponent of two coupled oscillators with commensurable frequencies driven by a small intensity real noise with dissipation. The generator for the eigenvalue problem associated with the moment Lyapunov exponent is derived without any restriction on the size of pth moment. An orthogonal expansion for the eigenvalue problem based on the Galerkin method is used to derive the stability results in terms of spectral densities. These results can be applied to study the moment and almost-sure stability of structural and mechanical systems subjected to stochastic excitation.
Dynamic Instability of an Elastic Disk Under the Action of a Rotating Friction Couple
Authors: Ouyang H. , Mottershead J. E.
Published: January 2005

This paper investigates the instability of the transverse vibration of a disk excited by two corotating sliders on either side of the disk. Each slider is a mass-spring-damper system traveling at the same constant speed around the disk. There are friction forces acting in the plane of the disk at the contact interfaces between the disk and each of the two sliders. The equation of motion of the disk is established by taking into account the bending couple acting in the circumferential direction produced by the different friction forces on the two sides of the disk. The normal forces and the friction couples produced by the rotating sliders are moving loads and are seen to bring about dynamic instability. Regions of instability for parameters of interest are obtained by the method of state space. It is found that the moving loads produced by the sliders are a mechanism for generating unstable parametric resonances in the subcritical speed range. The existence of stable regions in the parameter space of the simulated example suggests that the disk vibration can be suppressed by suitable assignment of the parameter values of the sliders.
Numerical Simulation of Steady Liquid-Metal Flow in the Presence of a Static Magnetic Field
Authors: Meir Amnon J. , Schmidt Paul G. , Bakhtiyarov Sayavur I. , Overfelt Ruel A.
Published: January 2005

We describe a novel approach to the mathematical modeling and computational simulation of fully three-dimensional, electromagnetically and thermally driven, steady liquid-metal flow. The phenomenon is governed by the Navier-Stokes equations, Maxwell’s equations, Ohm’s law, and the heat equation, all nonlinearly coupled via Lorentz and electromotive forces, buoyancy forces, and convective and dissipative heat transfer. Employing the electric current density rather than the magnetic field as the primary electromagnetic variable, it is possible to avoid artificial or highly idealized boundary conditions for electric and magnetic fields and to account exactly for the electromagnetic interaction of the fluid with the surrounding media. A finite element method based on this approach was used to simulate the flow of a metallic melt in a cylindrical container, rotating steadily in a uniform magnetic field perpendicular to the cylinder axis. Velocity, pressure, current, and potential distributions were computed and compared to theoretical predictions.
Fracture Simulation Using an Elasto-Viscoplastic Virtual Internal Bond Model With Finite Elements
Authors: Thiagarajan Ganesh , Huang Yonggang Y. , Hsia K. Jimmy
Published: January 2005

A virtual internal bond (VIB) model for isotropic materials has been recently proposed by Gao (Gao, H., 1997, “Elastic Waves in a Hyperelastic Solid Near its Plane Strain Equibiaxial Cohesive Limit,” Philos. Mag. Lett. 76, pp. 307–314) and Gao and Klein (Gao, H., and Klein, P., 1998, “Numerical Simulation of Crack Growth in an Isotropic Solid With Randomized Internal Cohesive Bonds,” J. Mech. Phys. Solids 46(2), pp. 187–218), in order to describe material deformation and fracture under both static and dynamic loading situations. This is made possible by incorporating a cohesive type law of interaction among particles at the atomistic level into a hyperelastic framework at the continuum level. The finite element implementation of the hyperelastic VIB model in an explicit integration framework has also been successfully described in an earlier work by the authors. This paper extends the isotropic hyperelastic VIB model to ductile materials by incorporating rate effects and hardening behavior of the material into a finite deformation framework. The hyperelastic VIB model is formulated in the intermediate configuration of the multiplicative decomposition of the deformation gradient framework. The results pertaining to the deformation, stress-strain behavior, loading rate effects, and the material hardening behavior are studied for a plate with a hole problem. Comparisons are also made with the corresponding hyperelastic VIB model behavior.
Three-Dimensional Steady-State String Motion in a Fluid Flow
Authors: Miroshnik Roman
Published: January 2005

The phenomenon of three-dimensional (3D) steady-state motion of a string traveling along an invariant curve in a flowing medium is studied. Existence conditions are found using a perturbation scheme where a known two-dimensional (2D) solution is used as an initial approximation.
Small CTD Phosphatases Function in Silencing Neuronal Gene Expression
Authors: Yeo Michele , Lee Soo-Kyung , Lee Bora , Ruiz Esmeralda C. , Pfaff Samuel L. , Gill Gordon N.
Published: January 2005

Neuronal gene transcription is repressed in non-neuronal cells by the repressor element 1 (RE-1)–silencing transcription factor/neuron-restrictive silencer factor (REST/NRSF) complex. To understand how this silencing is achieved, we examined a family of class-C RNA polymerase II (RNAPII) carboxyl-terminal domain (CTD) phosphatases [small CTD phosphatases (SCPs) 1 to 3], whose expression is restricted to non-neuronal tissues. We show that REST/NRSF recruits SCPs to neuronal genes that contain RE-1 elements, leading to neuronal gene silencing in non-neuronal cells. Phosphatase-inactive forms of SCP interfere with REST/NRSF function and promote neuronal differentiation of P19 stem cells. Likewise, small interfering RNA directed to the single
Drosophila
SCP unmasks neuronal gene expression in S2 cells. Thus, SCP activity is an evolutionarily conserved transcriptional regulator that acts globally to silence neuronal genes.
A Brief History of Seed Size
Authors: Moles Angela T. , Ackerly David D. , Webb Campbell O. , Tweddle John C. , Dickie John B. , Westoby Mark
Published: January 2005

Improved phylogenies and the accumulation of broad comparative data sets have opened the way for phylogenetic analyses to trace trait evolution in major groups of organisms. We arrayed seed mass data for 12,987 species on the seed plant phylogeny and show the history of seed size from the emergence of the angiosperms through to the present day. The largest single contributor to the present-day spread of seed mass was the divergence between angiosperms and gymnosperms, whereas the widest divergence was between Celastraceae and Parnassiaceae. Wide divergences in seed size were more often associated with divergences in growth form than with divergences in dispersal syndrome or latitude. Cross-species studies and evolutionary theory are consistent with this evidence that growth form and seed size evolve in a coordinated manner.
Sequence-Directed DNA Translocation by Purified FtsK
Authors: Pease Paul J. , Levy Oren , Cost Gregory J. , Gore Jeff , Ptacin Jerod L. , Sherratt David , Bustamante Carlos , Cozzarelli Nicholas R.
Published: January 2005

DNA translocases are molecular motors that move rapidly along DNA using adenosine triphosphate as the source of energy. We directly observed the movement of purified FtsK, an
Escherichia coli
translocase, on single DNA molecules. The protein moves at 5 kilobases per second and against forces up to 60 piconewtons, and locally reverses direction without dissociation. On three natural substrates, independent of its initial binding position, FtsK efficiently translocates over long distances to the terminal region of the
E. coli
chromosome, as it does in vivo. Our results imply that FtsK is a bidirectional motor that changes direction in response to short, asymmetric directing DNA sequences.
Illumination of the Melanopsin Signaling Pathway
Authors: Panda Satchidananda , Nayak Surendra K. , Campo Brice , Walker John R. , Hogenesch John B. , Jegla Tim
Published: January 2005

In mammals, a small population of intrinsically photosensitive retinal ganglion cells (ipRGCs) plays a key role in the regulation of nonvisual photic responses, such as behavioral responses to light, pineal melatonin synthesis, pupillary light reflex, and sleep latency. These ipRGCs also express melanopsin (Opn4), a putative opsin-family photopigment that has been shown to play a role in mediating these nonvisual photic responses. Melanopsin is required for the function of this inner retinal pathway, but its precise role in generating photic responses has not yet been determined. We found that expression of melanopsin in
Xenopus
oocytes results in light-dependent activation of membrane currents through the Gα
q
/Gα
11
G protein pathway, with an action spectrum closely matching that of melanopsin-expressing ipRGCs and of behavioral responses to light in mice lacking rods and cones. When coexpressed with arrestins, melanopsin could use all-
trans
-retinaldehyde as a chromophore, which suggests that it may function as a bireactive opsin. We also found that melanopsin could activate the cation channel TRPC3, a mammalian homolog of the
Drosophila
phototransduction channels TRP and TRPL. Melanopsin therefore signals more like an invertebrate opsin than like a classical vertebrate rod-and-cone opsin.
Interindividual Variation in Posture Allocation: Possible Role in Human Obesity
Authors: Levine James A. , Lanningham-Foster Lorraine M. , McCrady Shelly K. , Krizan Alisa C. , Olson Leslie R. , Kane Paul H. , Jensen Michael D. , Clark Matthew M.
Published: January 2005

Obesity occurs when energy intake exceeds energy expenditure. Humans expend energy through purposeful exercise and through changes in posture and movement that are associated with the routines of daily life [called nonexercise activity thermogenesis (NEAT)]. To examine NEAT's role in obesity, we recruited 10 lean and 10 mildly obese sedentary volunteers and measured their body postures and movements every half-second for 10 days. Obese individuals were seated, on average, 2 hours longer per day than lean individuals. Posture allocation did not change when the obese individuals lost weight or when lean individuals gained weight, suggesting that it is biologically determined. If obese individuals adopted the NEAT-enhanced behaviors of their lean counterparts, they might expend an additional 350 calories (kcal) per day.
A Giant Impact Origin of Pluto-Charon
Authors: Canup Robin M.
Published: January 2005

Pluto and its moon, Charon, are the most prominent members of the Kuiper belt, and their existence holds clues to outer solar system formation processes. Here, hydrodynamic simulations are used to demonstrate that the formation of Pluto-Charon by means of a large collision is quite plausible. I show that such an impact probably produced an intact Charon, although it is possible that a disk of material orbited Pluto from which Charon later accumulated. These findings suggest that collisions between 1000-kilometer-class objects occurred in the early inner Kuiper belt.
Nightglow in the Upper Atmosphere of Mars and Implications for Atmospheric Transport
Authors: Bertaux Jean-Loup , Leblanc François , Perrier Séverine , Quemerais E. , Korablev Oleg , Dimarellis E. , Reberac A. , Forget F. , Simon P. C. , Stern S. A. , Sandel Bill ,   the SPICAM team
Published: January 2005

We detected light emissions in the nightside martian atmosphere with the SPICAM (spectroscopy for the investigation of the characteristics of the atmosphere of Mars) ultraviolet (UV) spectrometer on board the Mars Express. The UV spectrum of this nightglow is composed of hydrogen Lyman α emission (121.6 nanometers) and the γ and δ bands of nitric oxide (NO) (190 to 270 nanometers) produced when N and O atoms combine to produce the NO molecule. N and O atoms are produced by extreme UV photodissociation of O
2
, CO
2
, and N
2
in the dayside upper atmosphere and transported to the night side. The NO emission is brightest in the winter south polar night because of continuous downward transport of air in this region at night during winter and because of freezing at ground level.
Hatching of an Accountable Science
Authors: Larsson Hans C. E.
Published: January 2005

The Dinosauria
2nd ed.
David B. Weishampel, Peter Dodson, and Halszka Osmólska, Eds.
. University of California Press, Berkeley, 2004. 879 pp. $95, £62. ISBN 0-520-24209-2.

The contributors offer dinosaur enthusiasts and researchers a definitive summary of our current knowledge of the group, which covers its systematics, spatial and temporal occurrences, and biology.
Cardiovascular risk in women with polycystic ovarian syndrome (PCOS)
Authors: Bickerton A S T , Clark N , Meeking D , Shaw K M , Crook M , Lumb P , Turner C , Cummings M H
Published: January 2005

Aims:Studies have suggested that polycystic ovary syndrome (PCOS) is associated with increased cardiovascular risk. The aim of this study was to examine cardiovascular risk profiles in women with PCOS compared with healthy age and weight matched control subjects using novel biochemical and biophysical markers.

Methods:After ethics committee approval, 11 women with PCOS and 12 controls were recruited (mean age, 32; SD, 6.5 years; mean body mass index (BMI), 33.1; SD, 5.9 kg/m2). Serum was analysed for lipid and lipoprotein profile (total and high density lipoprotein cholesterol, triglycerides, apolipoprotein B-100, apolipoprotein A1, lipoprotein (a)), and sialic acid, fibrinogen, homocysteine, and C reactive protein (CRP) concentrations. Endothelial function was also assessed by a standard venous occlusion plethysmography technique to measure reactive hyperaemic forearm blood flow (RH), and expressed as per cent increase from baseline.

Results:There were no significant differences in glucose, lipid, or lipoprotein concentrations between the two groups. Furthermore, sialic acid (PCOS: mean, 70.5; SD, 149 mg/litre; controls: mean, 71.3; SD, 112 mg/litre), fibrinogen (PCOS: mean, 3.1; SD, 1.0 g/litre; controls: mean, 3.3; SD, 0.7 g/litre), CRP (PCOS: mean, 4.6; SD, 4.2 mg/litre; controls: mean, 5.4l SD, 5.5 mg/litre), and RH (PCOS: mean, 158.7; SD, 135.5%; controls: mean, 200.1; SD, 114.2%) were similar.

Conclusions:There were no differences in surrogate markers of the processes linked to enhanced cardiovascular risk between patients with PCOS and weight matched controls.
Does human papillomavirus play a role in the development of bladder transitional cell carcinoma? A comparison of PCR and immunohistochemical analysis
Authors: Youshya S , Purdie K , Breuer J , Proby C , Sheaf M T , Oliver R T D , Baithun S
Published: January 2005

Aim:To investigate the role of human papillomavirus (HPV) in the development of bladder transitional cell carcinoma (TCC).

Methods:Seventy eight paraffin wax embedded TCC samples were tested for the presence of HPV by two methods. First, immunohistochemistry was carried out using a polyclonal antibody capable of detecting the capsid protein of all known papillomaviruses. The second method was a consensus GP5+/6+ primer mediated polymerase chain reaction (PCR) technique, with the products analysed by both agarose gel electrophoresis and an enzyme immunoassay using type specific oligonucleotide probes for 10 different mucosal genotypes. To exclude false negative results because of the poor quality of DNA extracted from paraffin wax embedded samples, the series was extended to include 20 further blocks for which the corresponding snap frozen unfixed tissue was available.

Results:The two methods produced contrasting results, with 47 of the 78 samples positive for HPV antigen and none positive for HPV DNA. HPV DNA was not detected in the 20 additional paraffin wax embedded TCCs or in the 20 paired unfixed samples. In contrast, HPV DNA was amplified by PCR from all six of the paraffin wax embedded cervical carcinoma and anogenital wart control samples.

Conclusion:The disparity between the two sets of results is probably caused by false positives resulting from the non-specificity of the polyclonal antibody used for immunohistochemistry. These results suggest that HPV is unlikely to play an aetiological role in the development of bladder TCC.
Tumour size and vascular invasion predict distant metastasis in stage I breast cancer. Grade distinguishes early and late metastasis
Authors: Westenend P J , Meurs C J C , Damhuis R A M
Published: January 2005

Background:Recent Dutch guidelines recommend adjuvant systemic treatment (AST) for women with high grade stage I breast carcinoma ⩾1 cm. High grade is defined as Bloom and Richardson grade 3 (B&R3), Nottingham modification, or mitotic activity (MAI) ⩾10/1.59 mm2.

Aims:To investigate the validity of these histological prognostic factors as the exclusive defining criteria.

Materials/methods:Fifty patients with stage I breast carcinoma who developed distant metastases and 50 matched controls without metastasis were studied; none had received AST.

Results:Cases more often had tumours ⩾1 cm (p = 0,019), B&R3 tumours (p = 0.059), grade 3 nuclei (p = 0.005), and vascular invasion (p = 0.007). No differences were found for MAI ⩾10 (p = 0.46). In multivariate analysis, the only significant variables were vascular invasion and tumour size (odds ratios: 8.21 and 5.35, respectively). In a separate analysis, the 50 cases were divided into 25 patients with early and 25 with late metastasis. Those with early metastasis more often had B&R3 tumours (p = 0.009) and grade 3 nuclei (p = 0.006). No differences were found for tumours ⩾1 cm, vessel invasion, or MAI ⩾10. Using the present Dutch guidelines for AST, based on B&R3, 20 cases and 11 controls would have received AST. Based on MAI ⩾10, 14 cases and 11 controls would have received AST.

Conclusions:Tumour size and vessel invasion are the best prognostic factors for disease free survival in patients with stage I breast cancer. Dutch selection criteria for AST for these patients need to be improved. Some prognostic factors are time dependent, making their use as selection criteria for AST more complicated.