bluuebunny/crossref_metadata_2025 huggingface dataset:
A NANOSCALE MESHFREE PARTICLE METHOD WITH THE IMPLEMENTATION OF THE QUASICONTINUUM METHOD
Authors: XIAO SHAOPING , YANG WEIXUAN
Published: September 2005

Since meshfree particle methods have advantages on simulating the problems involving extremely large deformations, fractures etc., they become attractive options to be used in the hierarchical multiscale modeling to approximate a large number of atoms. We propose a nanoscale meshfree particle method with the implementation of the quasicontinuum technique in this paper. The intrinsic properties of the material associated with each particle will be sought from the atomic level via the Cauchy-Born rule. The studies of a nano beam and a nano plate with a central crack show that such a hierarchical modeling can be beneficial from the advantages of meshfree particle methods.
COMPUTATIONAL STUDY OF INTERFACE EFFECT ON IMPACT LOAD SPREADING IN SiC MULTI-LAYERED TARGETS
Authors: DWIVEDI S. K. , DING J. L. , GUPTA Y. M.
Published: September 2005

The effect of finite strength interface with friction on lateral load spreading and phenomena of interface crack initiation and propagation in bonded multi-layered targets under high velocity impact are presented through axisymmetric finite element simulations. The finite element code DYNA2D, developed at the Lawrence Livermore National Laboratory, was augmented with a phenomenological damage model for the silicon carbide ( SiC ) ceramic and contact/cohesive interface model. Simulations were carried out for four target configurations under varying interface strength (Tm), critical strain energy release rate (Gc), and inter-layer friction coefficient (μL). It is shown that the high wave speed SiC remains a potential material for enhanced load spreading if the confinement is ensured to reduce/delay its damage. The load spreading also increases with the increase in μL that comes into play after the interface failure. However, the μL of unity or more needed to approach the upper bound of load spreading found in the perfectly bonded target layers is not practical. It is shown that the resilience of the multi-layered targets depends on Tm as well as the Gc. But, the lateral load spreading depends dominantly on Tm and reaches the upper bound with its increase. It is further shown that the interface cracks initiate and propagate in shear, mode II. The crack speed is invariably the maximum at initiation and is of the order of the longitudinal wave speed of materials on either side. The maximum initiation speed of 11.29Cs and 7.79Cs are predicted at the SiC -aluminum and steel- SiC interfaces for the frictionless case, where Cs is the shear wave speed of the more compliant aluminum or steel. The crack speed reduces monotonously after initiation, but it remains in the intersonic region for more than 150 ns. Whether the propagating crack tip attains the steady state speed depends on the available driving energy. The steady state crack speed of 0.86Cs to 1.21Cs is predicted only at the steel- SiC interface at 2 mm depth from the impact surface, lasts for more than 3 μs, is shown to be independent of the interface strength upto 300 MPa, and is also independent of the friction coefficient.
A GENETIC ALGORITHM BASED PROCEDURE FOR AUTOMATIC CRACK PROFILE IDENTIFICATION
Authors: LUO YUNHUA , SHAH ARVIND
Published: September 2005

This paper presents a genetic algorithm based procedure for automatic identification of crack profiles. In the procedure geometric modeling technique is applied to incorporate crack(s) into the structure under evaluation and a geometric model is generated. The geometric model is then used to generate finite element mesh. In solving forward problems, finite element meshes are adapted based on error estimation to improve accuracy in computed structural responses. Numerical results show that error from solving forward problems can largely slow down GA convergence and significantly affect the accuracy of estimated crack parameters. Mesh adaptation can effectively reduce the error, thus speeding up the convergence and improving accuracy.
A PARTICLE SWARM OPTIMIZATION-BASED ALGORITHM FOR JOB-SHOP SCHEDULING PROBLEMS
Authors: GE H. W. , LIANG Y. C. , ZHOU Y. , GUO X. C.
Published: September 2005

A novel particle swarm optimization (PSO)-based algorithm is developed for job-shop scheduling problems (JSSP), which are the most general and difficult issues in traditional scheduling problems. Our goal is to develop an efficient algorithm based on swarm intelligence for the JSSP. Thereafter a novel concept for the distance and velocity of particles in the PSO is proposed and introduced to pave the way for the JSSP. The proposed algorithm effectively exploits the capabilities of distributed and parallel computing systems, with simulation results showing the possibilities of high quality solutions for typical benchmark problems.
Reduced sampling schedule for the glucose minimal model: importance of Bayesian estimation
Authors: Magni Paolo , Sparacino Giovanni , Bellazzi Riccardo , Cobelli Claudio
Published: September 2005

The minimal model (MM) of glucose kinetics during an intravenous glucose tolerance test (IVGTT) is widely used in clinical studies to measure metabolic indexes such as glucose effectiveness (SG) and insulin sensitivity (SI). The standard (frequent) IVGTT sampling schedule (FSS) for MM identification consists of 30 points over 4 h. To facilitate clinical application of the MM, reduced sampling schedules (RSS) of 13–14 samples have also been derived for normal subjects. These RSS are especially appealing in large-scale studies. However, with RSS, the precision of SG and SI estimates deteriorates and, in certain cases, becomes unacceptably poor. To overcome this difficulty, population approaches such as the iterative two-stage (ITS) approach have been recently proposed, but, besides leaving some theoretical issues open, they appear to be oversized for the problem at hand. Here, we show that a Bayesian methodology operating at the single individual level allows an accurate determination of MM parameter estimates together with a credible measure of their precision. Results of 16 subjects show that, in passing from FSS to RSS, there are no significant changes of point estimates in nearly all of the subjects and that only a limited deterioration of parameter precision occurs. In addition, in contrast with the previously proposed ITS method, credible confidence intervals (e.g., excluding negative values) are obtained. They can be crucial for a subsequent use of the estimated MM parameters, such as in classification, clustering, regression, or risk analysis.
eNOS function is developmentally regulated: uncoupling of eNOS occurs postnatally
Authors: Mata-Greenwood Eugenia , Jenkins Chrystal , Farrow Kathryn N. , Konduri G. Ganesh , Russell James A. , Lakshminrusimha Satyan , Black Stephen M. , Steinhorn Robin H.
Published: September 2005

At birth, the transition to gas breathing requires the function of endothelial vasoactive agents. We investigated the function of endothelial nitric oxide synthase (eNOS) in pulmonary artery (PA) vessels and endothelial cells isolated from fetal and young (4-wk) sheep. We found greater relaxations to the NOS activator A-23187 in 4-wk-old compared with fetal vessels and that the NOS inhibitor nitro-l-arginine blocked relaxations in both groups. Relaxations in 4-wk vessels were not blocked by an inhibitor of soluble guanylate cyclase, 1H-[1,2,4]oxadiazolo-[4,3-a]quinoxalin-1-one, but were partially blocked by catalase. We therefore hypothesized that activation of eNOS produced reactive oxygen species in 4-wk but not fetal PA. To address this question, we studied NO and superoxide production by endothelial cells at baseline and following NOS stimulation with A-23187, VEGF, and laminar shear stress. Stimulation of NOS induced phosphorylation at serine 1177, and this event correlated with an increase in NO production in both ages. Upon stimulation of eNOS, fetal PA endothelial cells (PAEC) produced only NO. In contrast 4-wk-old PAEC produced superoxide in addition to NO. Superoxide production was blocked by l-NAME but not by apocynin (an NADPH oxidase inhibitor). l-Arginine increased NO production in both cell types but did not block superoxide production. Heat shock protein 90/eNOS association increased upon stimulation and did not change with developmental age. Cellular levels of total and reduced biopterin were higher in fetal vs. 4-wk cells. Sepiapterin [a tetrahydrobiopterin (BH4) precursor] increased basal and stimulated NO levels and completely blocked superoxide production. We conclude that the normal function of eNOS becomes uncoupled after birth, leading to a developmental adaptation of the pulmonary vascular system to produce oxygen species other than NO. We speculate this may be related to cellular production and/or maintenance of BH4 levels.
Effects of exercise training on papain-induced pulmonary emphysema in Wistar rats
Authors: Fló Claudia , Lopes Fernanda D. T. Q. S. , Kasahara David I. , Silva Anna Cecília D. , Jesus Rita C. C. , Rivero Dolores H. R. F. , Saldiva Paulo H. N. , Martins Milton A. , Jacob-Filho Wilson
Published: September 2005

The purpose of the present study was to evaluate the role of exercise training on the development of papain-induced emphysema in rats. Our hypothesis was that the increase in pulmonary tissue stretching associated with exercise could increase the severity of a protease-induced emphysema. Wistar rats were randomly assigned to four groups ( n = 10 for each group) that received, respectively, intratracheal infusion of papain (6 mg in 1 ml of 0.9% NaCl) or vehicle and were submitted or not to a protocol of exercise on a treadmill. Rats exercised at 13.3 m/min, 6 days/wk, for 9 wk (increasing exercise time, from 10 to 35 min). We measured respiratory system elastance and resistance, the size and weight of the heart, and pulmonary mean linear intercept (Lm). After 9 wk of exercise training, there were no differences in respiratory system resistance and elastance values among the four experimental groups. Volume of the heart was significantly greater in rats submitted to exercise training ( P = 0.007) compared with sedentary rats due to increases in volumes of both right and left cardiac chambers. Lm was significantly greater in rats that received papain compared with saline-infused rats ( P = 0.025). Surprisingly, this was true, even though there was no significant decrease in elastance, possibly due to connective tissue remodeling. However, Lm was significantly greater in papain + exercise rats compared with rats that received papain and were not submitted to exercise. We conclude that exercise training can increase alveolar damage induced by papain infusion.
Pulse transit time measured from the ECG: an unreliable marker of beat-to-beat blood pressure
Authors: Payne R. A. , Symeonides C. N. , Webb D. J. , Maxwell S. R. J.
Published: September 2005

The arterial pulse-wave transit time can be measured between the ECG R-wave and the finger pulse ( rPTT), and has been shown previously to have a linear correlation with blood pressure (BP). We hypothesized that the relationship between rPTT, preejection period (PEP; the R-wave/mechanical cardiac delay), and BP would vary with different vasoactive drugs. Twelve healthy men (mean age 22 yr) were studied. Beat-to-beat measurements were made of rPTT (using ECG and photoplethysmograph finger probe), intra-arterial radial pressure, PEP (using cardiac bioimpedance), and transit time minus PEP ( pPTT). Four drugs (glyceryl trinitrate, angiotensin II, norepinephrine, salbutamol) were administered intravenously over 15 min, with stepped dosage increase every 5 min and a 25-min saline washout between agents. All subjects in all conditions had a negative linear correlation ( R2 = 0.39) between rPTT and systolic BP (SBP), generally constant between different drugs, apart from four subjects who had a positive rPTT/SBP correlation with salbutamol. The 95% limits of agreement between measured and rPTT-predicted SBP were ±17.0 mmHg. Beat-to-beat variability of rPTT showed better coherence with SBP variability than it did with heart rate variability ( P < 0.001). PEP accounted for a substantial and variable proportion of rPTT (12–35%). Diastolic (DBP) and mean arterial BP (MAP) correlated poorly with rPTT ( R2 = 0.02 and 0.08, respectively) but better with pPTT ( rPTT corrected for PEP, R2 = 0.41 and 0.45, respectively). The 95% limits of agreement between measured and pPTT-predicted DBP were ± 17.3 mmHg. In conclusion, the negative correlation between rPTT and SBP is generally constant, even with marked hemodynamic perturbations. However, the relationship is not reliable enough for rPTT to be used as a surrogate marker of SBP, although it may be useful in assessing BP variability. DBP and MAP cannot be predicted from rPTT without correction for PEP. The significant contribution of PEP to rPTT means that rPTT should not be used as a marker of purely vascular function.
Re-determining the Nowotny chimney–ladder structure VGe1.82from powder diffraction data
Authors: Lind Hanna , Boström Magnus
Published: September 2005

The Nowotny chimney–ladder compound VGe1.82was redetermined from powder diffraction data and modelled with the incommensurately modulated composite approach. The dimensions of the tetragonal unit subcells area=5.9015(3) Å,cGe=2.6916(2)Å, andcV=4.9080(2)Å and the one-dimensional modulation vectors areqGe=0.45159(1)[001]*andqV=0.17656(1)[001]*. Comparison is made with a previous reported commensurate approximation of the structure with a 31-foldcGeaxis.
Crystal structure of low-cristobalite-type Al0.5Ga0.5PO4: A combined Rietveld refinement of neutron and X-ray diffraction data
Authors: Achary S. N. , Tyagi A. K. , Kulshreshtha S. K. , Jayakumar O. D. , Krishna P. S. R. , Shinde A. B. , Chakraborty K. R.
Published: September 2005

The low-cristobalite-type modification of Al0.5Ga0.5PO4 is prepared by annealing the amorphous precipitate of stoichiometric phosphate at 1300 °C. The phase purity of the sample is ascertained by powder X-ray diffraction. The crystal structure is refined by Rietveld refinements of the neutron and X-ray diffraction data of the polycrystalline powder. This compound crystallizes in an orthorhombic lattice with unit cell parameters, a=7.0295(8), b=7.0132(8), and c=6.9187(4) Å, V=341.08(6) Å3, Z=4 (Space group C 2221, No. 20). The crystal structure analysis reveals the random distribution of the Al3+ and Ga3+ having tetrahedral coordination with typical M–O (M=Al3+:Ga3+) bond lengths as 1.74 Å. Similarly, the P5+ have tetrahedral coordination with typical P–O bond lengths 1.52–1.54 Å. The Mo4 and PO4 tetraheda are linked by common corners forming a three-dimensional framework lattice. The details of the crystal structure are presented in this paper.
Synthesis and characterization of mixed fluorides with PbF2and ScF3
Authors: Achary S. N. , Tyagi A. K.
Published: September 2005

A series of mixed fluoride compositions with PbF2and ScF3were prepared by heating the intimate mixtures of component fluorides at 600 °C for 10 h followed by slowly cooling to room temperature. The products obtained were analyzed by powder XRD to reveal the phases present in them and hence the low-temperature phase equilibria in the PbF2-ScF3system. The phase equilibria show the fluorite-type solid solution up to the composition of about 15 mol% of ScF3in the PbF2lattice. The unit cell volume decreases with increasing ScF3contents in the fluorite-type solid solutions. Beyond the solubility limit, the biphasic mixture of the cubic fluorite-type solid solution and leftover ScF3is found to exist.
New X-ray powder diffraction data for heterometallic complexes with unsaturated organic ligands Cp(CO)2MnPt(μ-C=CHPh)(η2-dppm), [Cp(CO)2MnCu(μ-C=CHPh)]2(μ-Cl)2, CpMnFe2(μ3-C=CHPh)(CO)8 and η4-[Cp(CO)2MnC(CO)CHPh]Fe(CO)3(Cp=η5-C5H5;dppm=Ph2PCH2PPh2)
Authors: Antonova Alla B. , Chudin Oleg S. , Kirik Sergei D.
Published: September 2005

Four heterometallic carbonyl complexes: (1) Cp(CO)2MnPt(μ-C=CHPh)dppm) (2) [Cp(CO)2MnCu(μ-C=CHPh)(μ-Cl)]2, (3) CpMnFe2(μ3-C=CHPh)(CO)8, and (4) η4-[Cp(CO)2MnC(CO)CHPh]Fe(CO)3 have been studied by X-ray powder diffraction and their unit cell parameters are reported. Orthorhombic cell parameters for complex (1) are a=18.5719(14) Å, b=18.6092(14) Å, c=23.8117(18) Å, Z=8, space group Pbca. Monoclinic cell parameters found for complex (2) are a=11.5816(5) Å, b=7.9784(5) Å, c=16.7819(7) Å, β=105.460(2)°, Z=2, space group P21∕n. Orthorhombic cell parameters for complex (3) are a=13.5260(9) Å, b=15.1487(10) Å, c=10.3330(6) Å, Z=4, space group Pna21. Monoclinic cell parameters for complex (4) are a=10.3545(45) Å, b=8.0002(43) Å, c=21.8355(95) Å, β=102.89(2), Z=4, space group P21∕c. Parameters found for complexes (1–4) are in good agreement with those obtained from single crystal X-ray diffractometry.
Structural elucidation of stabilized tetragonal ThSiO4: A neutron diffraction study
Authors: Grover V. , Chakraborty Keka R. , Tyagi A. K.
Published: September 2005

A new compound Th0.9Ce0.1SiO4, iso-typic to zircon, was prepared by heating predried ThO2, CeO2, and SiO2 (in the mole ratio 0.9:0.10:1.0) by a two-step heating protocol. The polycrystalline sample obtained was characterized by Rietveld refinement of the observed neutron diffraction data with the starting model of tetragonal ThSiO4. It has a body centered tetragonal structure with space group I41∕amd and four formula units per unit cell. The unit-cell parameters are a=7.1238(4) Å and c=6.3186(95) Å. The RP, Rwp, and Re factors are 7.77%, 10.9%, and 4.85%, respectively. The incorporation of about 10 mol % cerium was used to stabilize the tetragonal modification of ThSiO4.
Crystal structure of potassium tetraperoxomolybdate (VI) K2[Mo(O2)4]
Authors: Grzywa M. , Różycka M. , Łasocha W.
Published: September 2005

Potassium tetraperoxomolybdate (VI) K2[Mo(O2)4] was prepared, and its X-ray powder diffraction pattern was recorded at low temperature (258 K). The unit cell parameters were refined to a=10.7891(2) Å, α=64.925(3)°, space group R−3c (167), Z=6. The compound is isostructural with potassium tetraperoxotungstate (VI) K2[W(O2)4] (Stomberg, 1988). The sample of K2[Mo(O2)4] was characterized by analytical investigations, and the results of crystal structure refinement by Rietveld method are presented; final RP and RWP are 9.79% and 12.37%, respectively.
Powder diffraction of sodalite in a multiphase ceramic used to immobilize radioactive waste
Authors: Frank S. M. , Barber T. L. , Lambregts M. J.
Published: September 2005

The title compound, ∣Na6Li1.6K0.4Cl2∣[Al6Si6O24]‐SOD, is similar to sodalite proper, but the introduction of Li and K into the structure creates a reduction in unit-cell volume and additional collapse of the framework tetrahedra. Refinement of an X-ray powder diffraction pattern of a multiphase material yielded for sodalite a lattice parameter of 0.88427 (2) nm, an Al–O–Si bond angle of 137.9(3°), and Al–O and Si–O bond lengths of 0.1730(5) nm and 0.1620(5) nm, respectively. The angle of the unique Al–O–Si bond corresponds well with the 138° obtained by 29Si solid-state magic-angle-spinning nuclear magnetic resonance spectroscopy. This characterization is important since the compound constitutes an essential part of a radioactive waste form intended for a high-level waste repository.
Regional Dendritic Variation in Neonatal Human Cortex: A Quantitative Golgi Study
Authors: Travis Katie , Ford Kevin , Jacobs Bob
Published: September 2005

The present study quantitatively compared the basilar dendritic/spine systems of lamina V pyramidal neurons across four hierarchically arranged regions of neonatal human neocortex. Tissue blocks were removed from four Brodmann’s areas (BAs) in the left hemisphere of four neurologically normal neonates (mean age = 41 ± 40 days): primary (BA4 and BA3-1-2), unimodal (BA18), and supramodal cortices (BA10). Tissue was stained with a modified rapid Golgi technique. Ten cells per region (N = 160) were quantified. Despite the small sample size, significant differences in dendritic/spine extent obtained across cortical regions. Most apparent were substantial differences between BA4 and BA10: total dendritic length was 52% greater in BA4 than BA10, and dendritic spine number was 67% greater in BA4 than BA10. Neonatal patterns were compared to adult patterns, revealing that the relative regional pattern of dendritic complexity in the neonate was roughly the inverse of that established in the adult, with BA10 rather than BA4 being the most complex area in the adult. Overall, regional dendritic patterns suggest that the developmental time course of basilar dendritic systems is heterochronous and is more protracted for supramodal BA10 than for primary or unimodal regions (BA4, BA3-1-2, BA18).
Neurotrophic Factor Receptor Expression and in vitro Nerve Growth of Geniculate Ganglion Neurons That Supply Divergent Nerves
Authors: Yamout Adam , Spec Andrej , Cosmano Jason , Kashyap Manoj , Rochlin M.William
Published: September 2005

We investigated which neurotrophic factors may contribute to the divergence of two peripheral nerves emanating from the geniculate ganglion. We compared receptor mRNA profiles of the neurons that supply the nerves, and also the growth of their neurites in response to neurotrophic factors in culture. Three mRNAs, Gfra2, TrkA, and TrkC, were differentially expressed. Only one ligand, Neurturin, promoted substantially different nerve regrowth from the nerves, and therefore may contribute to nerve divergence. Three receptor mRNAs were expressed in 100% of the neurons: TrkB, TrkB.T2 (kinase-lacking isoform), and NCAM-140. Ligands for these Trks and FRα-1 promoted more outgrowth than ligands for the other receptors. NT-3 and BDNF synergistically promoted outgrowth. Finally, receptors are coexpressed at random rates, arguing against the existence of neuronal subtypes defined by a combinatorial code of these receptors.
Prenatal Restraint Stress and Long-Term Affective Consequences
Authors: van den Hove D.L.A. , Blanco C.E. , Aendekerk B. , Desbonnet L. , Bruschettini M. , Steinbusch H.P. , Prickaerts J. , Steinbusch H.W.M.
Published: September 2005

Chronic or repeated stress during critical periods of human fetal brain development has been associated with various learning, behavioral and/or mood disorders in later life. In this investigation, pregnant Fischer 344 rats was individually restrained three times a day for 45 min during the last week of gestation in transparent plastic cylinders while at the same time being exposed to bright light. Control pregnant females were left undisturbed in their home cages. Anxiety and depressive-like behavior was measured in the offspring at an age of 6 months using the open field test, the home cage emergence test and the forced swim test. Prenatally stressed rats spent more time in the corners and less time along the walls of an open field, while no difference in total distance moved was observed. In addition, prenatally stressed rats took more time to leave their home cage in the home cage emergence test. On the other hand, no differences in immobility were observed in the forced swim test. Moreover, prenatally stressed rats showed lower stress-induced plasma corticosterone levels compared with control rats. Prenatal stress (PS) had no effect on the number of 5-bromo-2-deoxyuridine-positive cells – used as a measure for cell proliferation – in the dentate gyrus of these rats. These data further support the idea that PS may perturb normal anxiety-related development. However, the present data also suggest that an adaptive or protective effect of PS should not be ignored. Genetic factors are likely to play a role in this respect.
Auditory Deficits Associated with the Frings Mgr1 (Mass1) Mutation in Mice
Authors: Klein Brian D. , Fu Ying-Hui , Ptacek Louis J. , White H. Steve
Published: September 2005

The gene responsible for the audiogenic seizure (AGS) phenotype in Frings mice, which was identified and originally designated Mass1, is now referred to as Mgr1. Although the function of the gene product is not known, the expression pattern suggests a role in the developing CNS. Hearing impairment is often observed in AGS-susceptible rodents and is thought to contribute to the pathology of AGS. We therefore hypothesized that the Frings mouse exhibits early-onset hearing impairment and that the Frings Mgr1 mutation is responsible for the hearing impairment phenotype that leads to the development of AGS susceptibility. Auditory brainstem response (ABR) thresholds were used to evaluate auditory function in mice carrying the Frings Mgr1 allele and were compared with other AGS-susceptible and -resistant mice. ABR testing demonstrated that mice possessing the Frings Mgr1 allele exhibit a mild to moderate level of hearing impairment that is present during the days following hearing onset. Furthermore, the hearing impairment resulting from the Frings Mgr1 allele is relatively stable, which explains the long duration of AGS susceptibility exhibited by Frings mice compared with other AGS-susceptible mice.
Power and Sample Size Calculations for Genetic Case/Control Studies Using Gene-Centric SNP Maps: Application to Human Chromosomes 6, 21, and 22 in Three Populations
Authors: de La Vega Francisco M. , Gordon Derek , Su Xiaoping , Scafe Charles , Isaac Hadar , Gilbert Dennis A. , Spier Eugene G.
Published: September 2005

Power and sample size calculations are critical parts of any research design for genetic association. We present a method that utilizes haplotype frequency information and average marker-marker linkage disequilibrium on SNPs typed in and around all genes on a chromosome. The test statistic used is the classic likelihood ratio test applied to haplotypes in case/control populations. Haplotype frequencies are computed through specification of genetic model parameters. Power is determined by computation of the test’s non-centrality parameter. Power per gene is computed as a weighted average of the power assuming each haplotype is associated with the trait. We apply our method to genotype data from dense SNP maps across three entire chromosomes (6, 21, and 22) for three different human populations (African-American, Caucasian, Chinese), three different models of disease (additive, dominant, and multiplicative) and two trait allele frequencies (rare, common). We perform a regression analysis using these factors, average marker-marker disequilibrium, and the haplotype diversity across the gene region to determine which factors most significantly affect average power for a gene in our data. Also, as a ‘proof of principle’ calculation, we perform power and sample size calculations for all genes within 100 kb of the PSORS1 locus (chromosome 6) for a previously published association study of psoriasis. Results of our regression analysis indicate that four highly significant factors that determine average power to detect association are: disease model, average marker-marker disequilibrium, haplotype diversity, and the trait allele frequency. These findings may have important implications for the design of well-powered candidate gene association studies. Our power and sample size calculations for the PSORS1 gene appear consistent with published findings, namely that there is substantial power (>0.99) for most genes within 100 kb of the PSORS1 locus at the 0.01 significance level.
Conservative Medical Treatment and Intravenous Thrombolysis in Acute Stroke from Carotid T Occlusion
Authors: Wunderlich Michael T. , Stolz Erwin , Seidel Günter , Postert Thomas , Gahn Georg , Sliwka Ulrich , Goertler Michael
Published: September 2005

Background: We aimed to analyse the course of early recanalization and corresponding functional outcome in patients with an acute occlusion of the carotid T who were treated conservatively or underwent intravenous thrombolysis. Methods: Forty-two patients with an acute occlusion of the carotid T within 6 h were recruited from consecutive admissions to a neurological department participating in the Duplex Sonography in Acute Stroke study. All patients underwent a standardized admission and follow-up procedure. Colour-coded duplex sonography was performed on admission, 30 min after thrombolysis, and at 6 and 24 h after onset of symptoms. Recanalization of the carotid T was classified as complete, partial and absent. Functional outcome was rated with the modified Rankin scale (mRS) at 3 months as favourable (mRS 0–2) or poor (mRS 3–6). Results: Within 6 h, complete or partial recanalization occurred in 1 of 27 patients treated conservatively and in 6 of 15 thrombolysed patients. Intravenous thrombolysis predicted early recanalization also after adjustment for age, sex, cardioembolic stroke aetiology and time to treatment (adjusted odds ratio, OR, 39.7; 95% confidence interval, CI, 2.0–801.7; p = 0.016). An early recanalization was the only selected predictor of a favourable outcome (OR, 13.6; 95% CI, 1.0–179.0; p = 0.047) at regression analysis, and was achieved in 3 thrombolysed patients but in none with conservative medical treatment. Conclusions: In patients treated conservatively, functional outcome is poor and early recanalization rarely occurs. The latter can be achieved by intravenous thrombolysis with a rate comparable to that found at an intra-arterial approach without major intracranial bleeding complications. Early recanalization is associated with a better functional outcome.
Establishment and Characterization of a Pancreatic Carcinoma Cell Line Derived from Malignant Pleural Effusion
Authors: Starr A.N. , Vexler A. , Marmor S. , Konik D. , Ashkenasi-Voghera M. , Lev-Ari S. , Greif Y. , Ben-Yosef R.
Published: September 2005

Background/Aims:A novel cell line, designated p34, was developed from the malignant pleural effusion of a patient with carcinoma of pancreas. The objective of this work was to characterize this cell line. Method: The in vitrostudies included karyotype analysis, immunohistochemistry, XTT cell proliferation assay, analysis of the cell cycle by FACS and cell sensitivity to chemotherapeutic drugs and irradiation. Subcutaneous and intraspleen inoculations into nude mice were carried out to study the tumorigenicity and the metastatic tendency of this cell line. Results: The p34 cell line showed typical morphological characteristics of epithelial pancreatic tumor cells. The cells were hyperdiploid with a modal number of 48, and had two markers, deletion in the short arm of chromosome 2 and duplication of the short arm of chromosome 8. The doubling time was 16 h. Subcutaneous inoculation of the cells into nude mice yielded 100% tumorigenicity, and intraspleen inoculation resulted in extensive intra-abdominal spread. The antiproliferative effect of chemotherapy (gemcitabine, cisplatin, taxol and vinorelbine), chemopreventive agents (celecoxib and curcumin) and radiotherapy showed dose-dependent cytotoxicity. Conclusions: This p34 cell line can be used as a new model for studying various aspects of the biology of human pancreatic cancer and potential treatment approaches for the disease.
Linking the Struggle for Education and Social Justice: Historical Perspectives of African American Leadership in Schools
Authors: Murtadha Khaula , Watts Daud Malik
Published: September 2005

Societal barriers to the successful education of Black children were identified by the noted historian Carter G. Woodson more than 70 years ago in his classic text The Mis-Education of the Negro. Woodson argued that there were serious problems with inaccurate, ill-planned, depoliticized curriculum content and lack of resources, as well as problems with the poor, unethical preparation of teachers. Historically, Black educational leaders had to overcome these barriers as well as others to be of service to the African American community. They created schools where none existed, struggled against the perpetuation of unequal educational environments, or built viable alternative schools. Motivated by the belief that education would“uplift the race,” women and men organized and developed institutions to mitigate the harsh realities of Black life Through socially critical writings, oratorical power, and activism, many leaders succeeded in making a difference in the educational settings that served Black people. Their narratives and critiques, however, have not been incorporated as a central element in the literature of school administration, leadership, reform, and change.
Mentoring New Teachers: Implications for Leadership Practice in an Urban School
Authors: Tillman Linda C.
Published: September 2005

This article focuses on leadership practices and teacher mentoring in an urban school context. A central perspective of this discussion is the role of the urban school principal in implementing and facilitating mentoring arrangements that will lead to competence, retention, and improved student achievement. Results from a case study of a mentoring triad in a large, urban high school are presented. The participants were a 1st-year African American teacher, her mentor, and the principal. The article begins with a discussion of teacher mentoring. The discussion then shifts to the mentoring experiences of the 1st-year African American teacher. Next, three themes are discussed: (a) mentoring as a means for enhancing professional and personal competence; (b) mentoring as a means of transmitting the culture of the educational environment; and (c) mentoring as a catalyst for transformative leadership. The article concludes with a discussion and some implications for transformative leadership practices that can facilitate effective mentoring arrangements for new teachers in the urban school context.
African American Spirituality and Cornel West’s Notions of Prophetic Pragmatism: Restructuring Educational Leadership in American Urban Schools
Authors: Dantley Michael E.
Published: September 2005

Schools in America are facing rapidly changing demographics, and because of those changing demographics, this article makes the following propositions. First, the increasing demographic changes in urban schools demand new leadership approaches. Second, because many of the urban educational demands are shaped by ongoing social and cultural issues for addressing needs of African American students, perhaps the answer to leadership changes lies in African American culture. Third, and finally, one possible feature of the African American culture, the application of personal spirituality to community issues of social change and social justice, may provide a direction for educational leadership. The purpose of this article is to propose a theoretical base for reforming educational leadership in demographically changing public schools. With critical theory and antifoundational tenets of pragmatic thinking and postmodern thought interrogating the traditional canon of educational administration, educational leadership has had to, even if reluctantly, include voices of alternative perspectives into its discourse. This essay applies Cornel West’s notions of prophetic pragmatism along with the tenets of African American spirituality to serve as the foundation for this progressive transformation of leadership especially in urban schools.
Tempered Radicals and Servant Leaders: Black Females Persevering in the Superintendency
Authors: Alston Judy A.
Published: September 2005

Despite the small numbers of Black female superintendents and the overwhelming obstacles of the position, Black women who serve as public school superintendents continue to meet the challenges of educational leadership and are flourishing in their jobs. As noted in previous research on Black women in the superintendency and Black female leaders in general, there remains a paucity of research. What is it about these women that keeps them in these positions? This article will focus on Black female superintendents’ persistence in their positions in relation to the concepts of tempered radicalism and servant leadership.
The Practice of Educational Leadership in African American Communities of Learning: Context, Scope, and Meaning
Authors: Foster Lenoar
Published: September 2005

This article provides a synthesis that delineates the scope and context that give meaning, purpose, and setting to the exercise of effective educational leadership and to the attainment of meaningful student achievement within schools that serve large numbers of African American students. Historical, theoretical, and empirical frames of inquiry provide the background for understanding good leadership and leadership practices that address the learning needs of African American students. Understanding the interconnectedness of good leadership and cultural practices that support and sustain African American student achievement are to be found through an awareness of the unique framework of cultural uplift and interpersonal and institutional caring, hallmarks that have characterized effective school leadership and student achievement in African American learning communities.
Beyond indigenization and reconceptualization
Authors: Ferguson Kristin M.
Published: September 2005

In light of the limitations of existing models of social work exchange, an alternative multidirectional model of technology transfer is presented. Based on social development principles, this model would be effective in depicting the global dissemination of initiatives originating in developing countries that are successfully applied in the developed world.

French

En l'absence d'un modèle d'échange en service social, cet article présente un modèle alternatif multidirectionnel de transfert de technologies. Fondé sur des principes de développement social, ce modèle pourrait s'avérer un moyen efficace visant à démontrer que des initiatives provenant de pays en voie de développement obtiennent du succès dans le monde développé.

Spanish

Para aclarar las limitaciones del intercambio existente de modelos de trabajo social, se presenta un modelo global y multidireccional de transferencia technológica. Basado en los principios del desarrollo social, este modelo sería efectivo para representar la diseminación global de iniciativas que se originan en los países en desarrollo, las cuales son aplicadas con éxito dentro del mundo desarrollado.
Health care in the social development context
Authors: Juliá María , Kondrat Mary E.
Published: September 2005

Social development scholars and practitioners have long advocated an important role for indigenization and grassroots participation in designing and implementing social development programs. Because of the recognized connection between health and social development, they have increasingly advocated for more indigenous and participatory approaches in conducting health assessments and in the delivery of health programs of relevance to individuals, families and communities. This article presents a rationale for such participatory approaches and the arguments are illustrated by case studies from two different cultural contexts.

French

Les chercheurs et les practiciens dans le secteur du développement social préconisent depuis longtemps l'importance d'un rôle autochtone et tenant compte de la base de la société dans la planification et la mise en application de programmes de développement social. Reconnaissant le lien entre la santé et le développement social, ils recommandent une plus grande participation indigène dans l'évaluation de la santé et la mise en application de programmes de santé pertinents pour les individus, les familles et les communautés. Le présent article argumente en faveur d'une approche participative et illustre ses raisons pour ce faire à l'aide de deux études de cas provenant de deux différents contextes culturels.

Spanish

Estudiosos y practicantes del desarrollo social han asignado, desde hace tiempo, un papel importante a la participación indigenista y popular en el diseño e implementación de los programas de desarrollo social. A partir del reconocimiento de la conexión entre desarrollo social y salud, se han abocado a promover el aumento de la participación indígena en la conducción de las asesorías en salud y en el desarrollo de programas de salud de relevancia para individuos, familias y comunidades. Este trabajo presenta el fundamento de este tipo de acercamiento participativo y los argumentos se ilustran a partir de estudios de caso en dos contextos culturales diferentes.
A sampling of international practice variations
Authors: Norman Judith , Hintze Heather
Published: September 2005

Across the globe, social workers generally share common values and purposes, yet the focus of activities and practice parameters vary greatly. In an exploratory study, a survey of international practitioners revealed variable definitions of practice. The recent joint IASSW and IFSW definition of social work practice would likely help specific countries to clarify practice descriptions while promoting a more unified voice in social work efforts worldwide.

French

À travers le monde, les travailleurs sociaux partagent en général des valeurs et des buts communs. Pourtant, le centre des activités et les paramètres de pratique varient énormément. Les résultats de cette étude exploratoire des travailleurs sociaux internationaux indiquent qu'il existe des définitions variables de la pratique. La définition récente de la pratique en travail social conçue par AIETS et FITS pourrait aider des pays spécifiques à élaborer des descriptions de pratique particulières tout en favorisant une voix plus unifiée pour le travail social à travers le monde.

Spanish

A través del mundo, los trabajadores sociales generalmente comparten valores comunes y propósitos, aún cuando el enfoque de las actividades y los parámetros de la práctica varían enormemente. En un estudio exploratorio, una encuesta internacional de practicantes reveló definiciones diferentes de la práctica. La reciente definición común de la práctica del trabajo social por parte de organismos como la IASSW y la IFSW ayudarían bastante para que países específicos clarificasen las descripciones de la práctica; y así mismo a promover una voz más unificada en los esfuerzos del trabajo social a nivel mundial.
The psychosocial needs of adolescents affected by HIV/AIDS
Authors: Strydom H. , Raath H.
Published: September 2005

The article reports on HIV/AIDS-infected adolescents’ responses on their psychosocial needs and the responses of infected parents on the psychosocial needs of their adolescent children. Besides identifying particulars and other issues, specific psychosocial needs such as counselling, support, relationships and economic implications are discussed.

French

L'article révèle les réponses d'adolescents infectés par le VIH/SIDA sur leurs besoins psychosociaux et les réponses de parents infectés sur les besoins psychosociaux de leurs adolescents. Outre l'identification de particularités et de controverses, l'article discute des besoins en thérapie et en soutien et des implications économiques du problème.

Spanish

El artículo se basa en las respuestas sobre las necesidades psicosociales de los adolescentes infectados por el VIH y las respuestas de padres infectados sobre las necesidades psicosociales de sus hijos adolescentes. Además de identificar estas particularidades y otros aspectos, son discutidas también necesidades psicosociales específicas tales como consejo, apoyo, relaciones, y las implicaciones económicas.
The influence of HIV concordance and discordance on marital life
Authors: D’Cruz Premilla
Published: September 2005

This article examines the effects of HIV concordance and discordance on marital life. In-depth interviews were conducted with seven couples from Mumbai, India. Thematic analysis of their narratives indicated the influence of HIV concordance and discordance on the spousal relationship, sexual functioning, family formation, care and support, and the future of the family.

French

Cet article examine les effets de la concordance et de la discordance du VIH sur la vie maritale. Sept couples de Mumbai en Inde ont participé à des entrevues en profondeur. Une analyse thématique de leurs discours révèle l'influence de la concordance et de la discordance du VIH sur les relations conjugales, sur le fonctionnement sexuel, sur la formation de la famille, sur les soins et le soutien et sur l'avenir de la famille.

Spanish

En este artículo se examinan los efectos de la concordancia y discordancia sobre los efectos del VIH en la vida marital. Se realizaron entrevistas en profundidad con siete parejas de Mumbai, India. El análisis temático de sus narrativas indicó la influencia de la concordancia y discordancia de la influencia del VIH en las relaciones de pareja, el funcionamiento sexual, la formación familiar, el cuidado y apoyo, y el futuro de la familia.
Organizing across borders
Authors: Holden Chris
Published: September 2005

Internationalized providers of care services face competing incentives and pressures relating to profit and quality. Case studies of corporate providers of long-term care in the UK demonstrate that their mode of organization has important implications for both user choice and the organization of care work.

French

Les fournisseurs internationalisés sont soumis à des pressions et à des incitatifs concurrentiels pour produire des profits et de la qualité. Des études de cas portant sur les fournisseurs institutionnels d'assistance à long terme au Royaume-Uni révèlent que leur mode d'organisation a d'importantes répercussions tant au niveau du choix des bénéficiaires qu'au niveau de l'organisation du travail d'assistance.

Spanish

Los prestadores transnacionales de servicios se enfrentan con incentivos que compiten entre sí y con la tensión entre calidad y ganancia. Se estudian unoscasos de prestadores de cuidados de larga duración en el Reino Unido. Estos demuestran que el modo de organización tiene consecuencias importantes, tanto para opciones abiertas al usuario como para la organización de los cuidados.
Brief Note: Human rights and social work
Authors: Skegg Anne-Marie
Published: September 2005

Some social commentators are divided over whether human rights discourse is a powerful and valuable tool or just another form of western imposition. While navigating the grey area between respecting cultural diversity and upholding human rights is not easy, it can be done. Furthermore, it is important that it is.

French

Les opinions des commentateurs sociaux sur le discours des droits de la personne sont partagées: s'agit-il d'un outil valable et puissant ou d'une autre contrainte occidentale? Bien qu'il ne soit pas facile de tenir une position dans la zone grise se situant entre la diversité culturelle et le respect des droits de la personne, il est possible de le faire. En fait, il est important de le faire.

Spanish

Los comentaristas sociales están divididos sobre si el discurso de los derechos humanos es un instrumento poderoso e importante o simplemente otra forma más de imposición occidental. Navegar el área gris entre el respeto a la diversidad cultural y la defensa de los derechos humanos no es fácil, sin embargo es hacedero. Y mucho importa que así sea.
Globalisation, Cosmopolitanism and the Environment
Authors: Dobson Andrew
Published: September 2005

In this article the question of whether dialogic cosmopolitanism is an adequate normative response to globalisation is broached. First, a distinction is drawn between ‘interdependence’ and ‘asymmetrical’ analyses of globalisation, and a brief defence of the latter is offered. Asymmetrica globalisation is illustrated through environmental examples. Second, dialogic cosmopolitanism is described. It is argued that the normative focus on unconstrained dialogue of this type of cosmopolitanism runs the risk of underestimating the significance of what ‘subaltern’ populations have already managed to say about their condition, even in less-than-ideal dialogic circumstances. This leads to the suggestion that in an asymmetrically globalising world, more justice as well as more unconstrained dialogue is what is required.