bluuebunny/crossref_metadata_2025 huggingface dataset:
Staphylococcus aureus‐derived peptidoglycan induces Cx43 expression and functional gap junction intercellular communication in microglia
Authors: Garg Sarita , Syed Mohsin Md. , Kielian Tammy
Published: September 2005

Gap junctions serve as intercellular conduits that allow the exchange of small molecular weight molecules (up to 1 kDa) including ions, metabolic precursors and second messengers. Microglia are capable of recognizing peptidoglycan (PGN) derived from the outer cell wall of Staphylococcus aureus, a prevalent CNS pathogen, and respond with the robust elaboration of numerous pro‐inflammatory mediators. Based on recent reports demonstrating the ability of tumor necrosis factor‐α and interferon‐γ to induce gap junction coupling in macrophages and microglia, it is possible that pro‐inflammatory mediators released from PGN‐activated microglia are capable of inducing microglial gap junction communication. In this study, we examined the effects of S. aureus‐derived PGN on Cx43, the major connexin in microglial gap junction channels, and functional gap junction communication using single‐cell microinjections of Lucifer yellow (LY). Exposure of primary mouse microglia to PGN led to a significant increase in Cx43 mRNA and protein expression. LY microinjection studies revealed that PGN‐treated microglia were functionally coupled via gap junctions, the specificity of which was confirmed by the reversal of activation‐induced dye coupling by the gap junction blocker 18‐α‐glycyrrhetinic acid. In contrast to PGN‐activated microglia, unstimulated cells consistently failed to exhibit LY dye coupling. These results indicate that PGN stimulation can induce the formation of a functional microglial syncytium, suggesting that these cells may be capable of influencing neuroinflammatory responses in the context of CNS bacterial infections through gap junction intercellular communication.
Extracellular histidine residues identify common structural determinants in the copper/zinc P2X2 receptor modulation
Authors: Lorca Ramón A. , Coddou Claudio , Gazitúa M. Consuelo , Bull Paulina , Arredondo Cristián , Huidobro‐Toro J. Pablo
Published: September 2005

To assess the mechanism of P2X2 receptor modulation by transition metals, the cDNA for the wild‐type receptor was injected to Xenopus laevis oocytes and examined 48–72 h later by the two‐electrode voltage‐clamp technique. Copper was the most potent of the trace metals examined; at 10 μm it evoked a 25‐fold potentiation of the 10 μm ATP‐gated currents. Zinc, nickel or mercury required 10‐fold larger concentrations to cause comparable potentiations, while palladium, cobalt or cadmium averaged only 12‐ and 3‐fold potentiations, respectively. Platinum was inactive. The non‐additive effect of copper and zinc at 10–100 μm suggests a common site of action; these metals also shifted to the left the ATP concentration–response curves. To define residues necessary for trace metal modulation, alanines were singly substituted for each of the nine histidines in the extracellular domain of the rat P2X2 receptor. The H120A and H213A mutants were resistant to the modulator action of copper, zinc and other metals with the exception of mercury. Mutant H192A showed a reduction but not an abrogation of the copper or zinc potentiation. H245A showed less affinity for copper while this mutant flattened the zinc‐induced potentiation. Mutant H319A reduced the copper but not the zinc‐induced potentiation. In contrast, mutants H125A, H146A, H152A and H174A conserved the wild‐type receptor sensitivity to trace metal modulation. We propose that His120, His192, His213 and His245 form part of a common allosteric metal‐binding site of the P2X2 receptor, which for the specific coordination of copper, but not zinc, additionally involves His319.
JNK inhibitory kinase is up‐regulated in retinal ganglion cells after axotomy and enhances BimEL expression level in neuronal cells
Authors: Wakabayashi Taketoshi , Kosaka Jun , Oshika Tetsuro
Published: September 2005

Optic nerve transection results in retinal ganglion cell (RGC) death in adult mammals, after the alteration of gene expression of RGCs. To elucidate the molecular mechanism by which axotomy induces RGC death, we isolated the molecules up‐regulated after optic nerve transection. One of these, axomtomy‐related gene (ARG)357, an 895‐amino‐acid protein containing a complete serine–threonine kinase domain, was isolated from a subtraction library of the rat retina. The sequence showed that this gene was a rat homolog of human c‐Jun N‐terminal kinase (JNK) inhibitory kinase and so belonged to the germinal center kinase‐VIII subfamily of Sterile20s protein kinase. We designated ARG357 as rat JNK inhibitory kinase (JIK). Rat JIK was expressed ubiquitously in various tissues and was highly expressed in the retina, with selective expression in RGCs. After axotomy, BimEL and Hrk, which are BH3‐only proteins, and rat JIK were up‐regulated in RGCs. Overexpression of rat JIK in neuronal cells up‐regulated the expression of BimEL, but not that of Hrk. These results indicate that JIK may contribute to axotomy‐induced RGC death by up‐regulating the expression of BH3‐only protein.
Loss of Usp14 results in reduced levels of ubiquitin in ataxia mice
Authors: Anderson Christopher , Crimmins Stephen , Wilson Julie A. , Korbel Greg A. , Ploegh Hidde L. , Wilson Scott M.
Published: September 2005

The ataxia (axJ) mutation is a spontaneous recessive mutation that results in reduced expression of ubiquitin‐specific protease 14, Usp14. Mice homozygous for the axJ mutation are retarded for growth and exhibit several behavioral disorders, including a resting tremor and hindlimb paralysis. Although pathological defects appear to be limited to the central nervous system, reduction of Usp14 expression was widespread in the axJ mice. Usp14 co‐fractionated with proteasomes isolated from livers and brains of wild‐type mice. Proteasomes isolated from the axJ brains still possessed deubiquitinating activity and were functionally competent to hydrolyze 20S proteasomal substrates in vitro. However, the levels of monomeric ubiquitin were reduced approximately 35% in most of the axJ tissues examined. These results indicate that Usp14 functions to maintain the cellular levels of monomeric ubiquitin in mammalian cells, and that alterations in the levels of ubiquitin may contribute to neurological disease.
Astrocyte–neurone communication following oxygen–glucose deprivation
Authors: Griffin S. , Clark J. B. , Canevari L.
Published: September 2005

We looked at the possible interactions between astrocytes and neurones during reperfusion using an in vitro model of ischaemia–reperfusion injury, as a controlled environment that lends itself easily to manipulation of the numerous variables involved in such an insult. We constructed a chamber in which O2 can be lowered to a concentration of 1 µm and developed a primary cortical neuronal culture that is 99% pure and can survive to at least 10 days in vitro. We also established a novel system for the co‐culture of astrocytes and neurones in order to study the communication between these cells in a manner that allows the complete separation of one cell type from another. Neurone cultures showed profound cell death following an ischaemic period of only 15 min. We co‐cultured neurones that had been subjected to a 15‐min ischaemic insult with either non‐insulted astrocytes or astrocyte‐conditioned medium during the reperfusion stage. Both astrocytes and astrocyte‐conditioned medium enhanced neuronal survival. Our data also suggest that astrocyte‐sourced neuronal glutathione synthesis may play a role in preventing neuronal death.
Role of PKC‐α,γ isoforms in regulation of c‐Fos and TH expression after naloxone‐induced morphine withdrawal in the hypothalamic PVN and medulla oblongata catecholaminergic cell groups
Authors: Benavides Marta , Laorden M. Luisa , Marín M. Teresa , Milanés M. Victoria
Published: September 2005

We previously demonstrated that morphine withdrawal induced hyperactivity of the hypothalamus‐pituitary‐adrenocortical axis by activation of noradrenergic pathways innervating the hypothalamic paraventricular nucleus (PVN), as evaluated by Fos expression and corticosterone release. The present study was designed to investigate the role of protein kinase C (PKC) in this process by estimating changes in PKCα and PKCγ immunoreactivity, and whether pharmacological inhibition of PKC would attenuate morphine withdrawal‐induced c‐Fos expression and changes in tyrosine hydroxylase (TH) immunoreactivity levels in the PVN and nucleus tractus solitarius/ ventrolateral medulla (NTS/VLM). Dependence on morphine was induced in rats by 7 day s.c. implantation of morphine pellets. Morphine withdrawal was induced on day 8 by an injection of naloxone. The protein levels of PKCα and γ were significantly down‐regulated in the PVN and NTS/VLM from the morphine‐withdrawn rats. Morphine withdrawal induced c‐Fos expression in the PVN and NTS/VLM, indicating an activation of neurons in those nuclei. TH immunoreactivity was increased in the NTS/VLM after induction of morphine withdrawal, whereas there was a decrease in TH levels in the PVN. Infusion of calphostin C, a selective protein kinase C inhibitor, produced a reduction in the morphine withdrawal‐induced c‐Fos expression. Additionally, the changes in TH levels in the PVN and NTS/VLM were significantly modified by calphostin C. The present results suggest that activated PKC in the PVN and catecholaminergic brainstem cell groups may be critical for the activation of the hypothalamic‐pituitary adrenocortical axis in response to morphine withdrawal.
Contrasting textural record of two distinct metamorphic events of similar P–T conditions and different durations
Authors: LEXA O. , ŠTÍPSKÁ P. , SCHULMANN K. , BARATOUX L. , KRÖNER A.
Published: September 2005

A structural, metamorphic and geochronological study of the Staré Město belt implies the existence of two distinct metamorphic events of similar peak P–T conditions (700–800 °C, 8–10 kbar) during the Cambro‐Ordovician and the Carboniferous tectonometamorphic events. The hypothesis of two distinct periods of metamorphism was suggested on the basis of structural discordance between an undoubtedly Carboniferous granodiorite sill intrusion and earlier Cambro‐Ordovician fabrics of a banded amphibolite complex. The analysis of crystal size distribution (CSD) shows high nucleation density (N0) and low average growth rate (Gt) for Carboniferous mylonitic metagabbros and mylonitic granodiorites. The parameter N0 decreases whereas the quantity Gt increases towards higher temperatures progressively approaching the values obtained from the Cambro‐Ordovician banded amphibolite complex. The spatial distribution of amphibole and plagioclase shows intense mechanical mixing for lower‐temperature mylonitic metagabbros. In high‐temperature mylonites a strong aggregate distribution is developed. Cambro‐Ordovician amphibolites unaffected by Carboniferous deformation show a regular to anticlustered spatial distribution resulting from heterogeneous nucleation of individual phases. This pattern, together with CSD, was subsequently modified by the grain growth and textural equilibration controlled by diffusive mass transfer during Carboniferous metamorphism. The differences between the observed textures of the amphibolites are interpreted to be a consequence of the different durations of the Carboniferous and Cambro‐Ordovician thermal events.
Mineral evolution of a garnet‐pyroxenite nodule within eclogite, eastern Sulu ultrahigh‐pressure metamorphic terrane, East China
Authors: YANG T. N. , ZENG L. , LIOU J. G.
Published: September 2005

Detailed microtextural observations and bulk chemical analysis were undertaken on a garnet‐pyroxenite nodule within retrograde eclogites from the NE Sulu ultrahigh‐pressure metamorphic (UHPM) terrane. The results suggest that the protolith was a cumulate from a gabbroic body. The nodule consists primarily of coarse clinopyroxene grains with a very high content of the Ca‐Tschermakite molecule. Microscopic observations and back‐scattered electron images (BSE) demonstrate a complicated intergrowth of clinopyroxene, garnet and ilmenite, which represents the peak metamorphic assemblage. The primary clinopyroxene grains are armoured with a thin garnet corona up to 0.5 mm wide that forms an interconnected network. Within the clinopyroxene grains, four sets of garnet lamellae are distributed along crystallographic planes; locally, a vermicular intergrowth of garnet and diopside is developed. Besides the garnet, parallel arrays of ilmenite blebs are common within the clinopyroxene. Hydrous minerals such as amphibole, zoisite and titanite formed at later stages, and replaced diopside, garnet and ilmenite respectively. The P–T conditions determined for the formation of the garnet lamellae indicate that the garnet pyroxenite experienced UHP metamorphism at the same peak P–T condition as its host eclogite. The very high Ca‐Tschermakite content (31–34 mol.%) of the primary clinopyroxene indicates crystallization at about 9–17 kbar and 1250–1450 °C, and together with the microtextural observations, suggests that the protolith of the garnet pyroxenite was a cumulate from a former gabbroic body, in which case, the host eclogite might represent the gabbroic body.
A new method to calculate end‐member thermodynamic properties of minerals from their constituent polyhedra II: heat capacity, compressibility and thermal expansion
Authors: VAN HINSBERG V. J. , VRIEND S. P. , SCHUMACHER J. C.
Published: September 2005

Thermodynamic calculations in petrology are generally performed at pressures and temperatures beyond the standard state conditions. Accurate prediction of mineral equilibria therefore requires knowledge of the heat capacity, thermal expansion and compressibility for the minerals involved. Unfortunately, such data are not always available. In this contribution we present a data set to estimate the heat capacity, thermal expansion and compressibility of mineral end‐members from their constituent polyhedra, based on the premise that the thermodynamic properties of minerals can be described by a linear combination of the fractional properties of their constituents. As such, only the crystallography of the phase of interest needs to be known. This approach is especially powerful for hypothetical mineral end‐members and for minerals, for which the experimental determination of their thermodynamic properties is difficult. The data set consists of the properties for 35 polyhedra in the system K–Na–Ca–Li–Be–Mg–Mn–Fe–Co–Ni–Zn–Al–Ti–Si–H, determined by multiple linear regression analysis on a data set of 111 published end‐member thermodynamic properties. The large number of polyhedra determined allows calculation of a much larger variety of phases than was previously possible, and the choice of constituents together with the large number of thermodynamic input data results in estimates with associated uncertainty of generally <5%. The quality of the data appears to be sufficiently accurate for thermodynamic modelling as demonstrated by modelling the stability of margarite in the CASH system and the position of the talc–staurolite–chloritoid–pyrope absent invariant point in the KMASH system. In both cases, our results overlap within error with published equivalents.
A thermodynamic model for Ca–Na clinoamphiboles in Na2O–CaO–FeO–MgO–Al2O3–SiO2–H2O–O for petrological calculations
Authors: DALE J. , POWELL R. , WHITE R. W. , ELMER F. L. , HOLLAND T. J. B.
Published: September 2005

A calibration is presented for an activity–composition model for amphiboles in the system Na2O–CaO–FeO–MgO–Al2O3–SiO2–H2O–O (NCFMASHO), formulated in terms of an independent set of six end‐members: tremolite, tschermakite, pargasite, glaucophane, ferroactinolite and ferritschermakite. The model uses mixing‐on‐sites for the ideal‐mixing activities, and for the activity coefficients, a macroscopic multicomponent van Laar model. This formulation involves 15 pairwise interaction energies and six asymmetry parameters. Calibration of the model is based on the geometrical constraints imposed by the size and shape of amphibole solvi inherent in a data set of 71 coexisting amphibole pairs from rocks, formed over 400–600 °C and 2–18 kbar. The model parameters are calibrated by combining these geometric constraints with qualitative consideration of parameter relationships, given that the data are insufficient to allow all the model parameters to be determined from a regression of the data. Use of coexisting amphiboles means that amphibole activity–composition relationships are calibrated independently of the thermodynamic properties of the end‐members. For practical applications, in geothermobarometry and the calculation of phase diagrams, the amphibole activity–composition relationships are placed in the context of the stability of other minerals by evaluating the properties of the end‐members in the independent set that are in internally consistent data sets. This has been performed using an extended natural data set for hornblende–garnet–plagioclase–quartz, giving the small adjustments necessary to the enthalpies of formation of tschermakite, pargasite and glaucophane for working with the Holland and Powell data set.
Ocean‐floor hydrothermal metamorphism in the Limousin ophiolites (western French Massif Central): evidence of a rare preserved Variscan oceanic marker
Authors: BERGER J. , FEMENIAS O. , MERCIER J. C. C. , DEMAIFFE D.
Published: September 2005

The Limousin ophiolite is located at the suture zone between two major thrust sheets in the western French Massif Central. This ophiolitic section comprises mantle‐harzburgite, mantle‐dunite, wehrlites, troctolites and layered gabbros. It has recorded a static metamorphic event transforming the gabbros into undeformed amphibolites and the magmatic ultramafites into serpentinites and/or pargasite‐bearing chloritites. With various thermobarometric methods, it is possible to show that the different varieties of amphibole have registered low‐P (c. 0.2 GPa) conditions with temperature ranging from high‐T, late‐magmatic conditions to greenschist–zeolite metamorphic facies. The abundance of undeformed metamorphic rocks (which is typical of the lower oceanic crust), the occurrence of Ca–Al (–Mg) metasomatism illustrated by the growth of Ca–Al silicates in veins or replacing the primary magmatic minerals, the P–T conditions of the metamorphism and the numerous similarities with oceanic crustal rocks from Ocean Drilling Program and worldwide ophiolites are the main arguments for an ocean‐floor hydrothermal metamorphism in the vicinity of a palaeo‐ridge. Among the West‐European Variscan ophiolites, the Limousin ophiolites constitute an extremely rare occurrence that has not been involved in any HP (subduction‐related) or MP (orogenic) metamorphism as observed in other ophiolite occurrences (i.e. France, Spain and Germany).
Bi‐acromial Dimples: A Series of Seven Cases
Authors: Beillard Charlotte , Guillet Gérard , Vabres Pierre , Dagregorio Guy , Larregue Marc
Published: September 2005

Abstract:  Seven patients with bi‐acromial dimples are reported, with a family history in only one. This skin condition presented as an anatomic peculiarity without associated abnormalities. Although it has been previously documented as a finding in malformation syndromes such as the 18q syndrome, we point out that it may be found quite frequently in isolation and without morbidity. Therefore, it should be mainly considered as an anatomic variation without pathologic significance.
Spectrum of Phenotypic Manifestations from a Single Point Mutation of the p63 Gene, Including New Cutaneous and Immunologic Findings
Authors: Steele Jennifer A. , Hansen Heather , Arn Pamela , Kwong Pearl C.
Published: September 2005

Abstract:  Mutations in the p63 gene have been identified in five human disorders characterized by varying degrees of limb anomalies, ectodermal dysplasia, and facial clefts. We report a new point mutation in the p63 gene in a family in which the mother was initially diagnosed with Rapp–Hodgkin syndrome and her two offspring manifested ankyloblepharon, ectodermal defects, cleft lip and palate, syndrome. These three patients are the first to be reported with this particular mutation, which consists of a change from glycine to aspartic acid at position 506 on exon 14. The clinical spectrum observed in the three family members highlights the wide range of phenotypic variations that result from a single point mutation in the p63 gene. The mother lacks certain features classically associated with AEC, dermatitis of the scalp in particular. Severe erosive dermatitis of the scalp developed in both offspring, along with previously undescribed poikilodermatous skin changes and a deficiency of CD4 T lymphocytes. The new and varied phenotypic features noted in these patients emphasize the spectrum of disease caused by mutations in the p63 gene and raise the possibility of a role for it in maintaining immunocompetence.
Periocular Vitiligo with Onset Around a Congenital Divided Nevus of the Eyelid
Authors: Guerra‐Tapia A. , Isarría María José
Published: September 2005

Abstract:  Leukoderma in association with congenital melanocytic nevi is a rare phenomenon; nevertheless several reports have been published in the literature. We present a 15‐year‐old boy born with a pigmented lesion on the lower and upper eyelid diagnosed as a congenital divided nevus of the eyelid. At the age of 13, he developed a depigmented area around the nevus and was diagnosed at first as having a halo nevus in a congenital nevus. Over the next two years, an area of depigmentation appeared around the contralateral eye. At the present time, the patient has bilateral periocular depigmentation. Congenital divided nevus of the eyelid is a rare lesion, and no reports have been published to date of depigmentation in association with this lesion. Our patient presented with depigmentation around the nevus as in a halo nevus phenomenon, although at the present time, the depigmented area has a symmetric periocular distribution, and therefore can be labeled as periocular vitiligo associated with a congenital divided nevus.
Clear‐Cell Hidradenoma of the Forearm in a Young Boy
Authors: Ozawa Toshiyuki , Fujiwara Masao , Nose Kensuke , Muraoka Michinari
Published: September 2005

Abstract:  We treated a 5‐year‐old boy with clear‐cell hidradenoma of the forearm. Our literature search found only one previous report of this disease occurring during the first decade of life, and the present patient is the first with involvement of the limbs. This presentation demonstrates that clear‐cell hidradenoma needs to be considered in the differential diagnosis of cutaneous tumors even in young children, which is of interest because malignant transformation can occur.
Successful Treatment of Refractory Childhood Pemphgus Vulgaris with Anti‐CD20 Monoclonal Antibody (Rituximab)
Authors: Kong Heidi H. , Prose Neil S. , Ware Russell E. , Hall Russell P.
Published: September 2005

Abstract:  Pemphigus vulgaris is an uncommon autoimmune blistering skin disorder that is particularly rare in children. Immunosuppressive treatment can be challenging. Rituximab (anti‐CD20 monoclonal antibody) has been used to treat autoimmune disorders by depletion of CD20 B cells. Successful rituximab therapy has been reported in adults with refractory pemphigus vulgaris. We present a girl with childhood pemphigus vulgaris unresponsive to treatment with azathioprine, mycophenolate mofetil, plasmapheresis, and intravenous immunoglobulin with systemic prednisone who responded to treatment with rituximab. She had a corresponding decline in circulating antibodies against desmoglein 1 and 3 and a decline in diphtheria and tetanus‐specific antibody titers.
Benign Cephalic Histiocytosis in a British‐African Child
Authors: Dadzie Ophelia , Hopster Debbie , Cerio Rino , Wakeel Riadh
Published: September 2005

Abstract:  A 14‐month‐old British‐African child presented with an asymptomatic eruption localized to her face and upper limbs. At the age of 17 months the eruption had started to spontaneously regress. Histologic examination of a biopsy specimen from a papular lesion on the arm showed a histiocytic infiltrate in the superficial dermis. Immunohistochemical studies showed negative staining for the Langerhans cell markers, CD1a and S‐100 protein, while staining for the macrophage/histiocytic markers, CD68 and factor XIIIa, were positive. The clinical and histologic features in this patient are consistent with the rare, non‐Langerhans, histiocytic disorder known as benign cephalic histiocytosis. As far as we are aware, this represents the first published occurrence in a child of African origin, emphasizing the widespread nature of this condition.
RISCALW: A Windows Program for Risk Calculation in Families with Duchenne Muscular Dystrophy
Authors: Fischer C. , Krüger J. , Gross W.
Published: September 2005

RISCALW is a novel convenient Windows program for risk calculation in families with Duchenne muscular dystrophy. It is based on an extended genetic model which includes germline mosaicism and different new mutation rates depending on sex and mutation type. Arbitrary family structures and additional diagnostic information such as genotypes from intragenic and flanking genetic markers of the dystrophin gene, creatin kinase values, and female deletion test results can be taken into account. Comprehensive online help is available. RISCALW has been extensively tested in more than 100 families. The user is able to perform risk calculations in large families in an easy way, and thus explore the dependence of the results on different model assumptions, for example different mutation rates in males and females. A detailed handbook and example files are distributed with the program.

RISCALW is freely available for scientific use at http://www.riscalw.uni‐hd.de.
A Comparison of Individual Genotyping and Pooled DNA Analysis for Polymorphism Validation Prior to Large‐Scale Genetic Studies
Authors: Yang H.‐C. , Lin C.‐H. , Hung S.‐I. , Fann C. S. J.
Published: September 2005

Polymorphism validation is an important issue in genetic studies because only polymorphic markers provide useful information. We analyzed genetic data for 180 SNPs in the human major histocompatibility complex region in Caucasian and Taiwanese populations, and evaluated ethnic heterogeneity between these populations to illustrate the importance of polymorphism validation. An initial individual genotyping experiment (IGE) with 95 samples was compared with a DNA pooling allele‐typing experiment (PAE) of 630 individuals for polymorphism validation based on authentic data sets. Afterwards, all samples were genotyped individually in a confirmation study. Under narrow (broad) polymorphism criteria, 24 (41) polymorphic SNPs in Caucasians could not be validated in the Taiwanese population, suggesting a 13% (23%) inconsistency rate and revealing a strong discrepancy between genetic backgrounds, probably due to ethnic heterogeneity. IGE yielded high sensitivity and specificity for polymorphism validation, but may be sensitive to sampling variation. PAE showed high sensitivity (97%) and specificity (100%) using a narrow polymorphism criterion, but reduced specificity (83%) using a broad criterion. Public domain polymorphism databases should therefore be used with caution and polymorphism validation should be performed routinely prior to conducting large‐scale genetic studies. PAE is a cost‐saving, reliable alternative to IGE for polymorphism validation, especially for a stringent polymorphism criterion.
Comparison of Two Luting Agents Used for the Retention of Cast Dowel and Cores
Authors: Habib Barry , Von Fraunhofer Joseph Anthony , Driscoll Carl F.
Published: September 2005

Purpose: The first purpose of this study was to compare the retentive values of zinc phosphate and Panavia F resin cements when used for luting cast dowel and cores. The second purpose was to determine whether the use of a lubricant when making the resin pattern for a custom dowel and core would have an effect on the final retention of dowels cemented with either zinc phosphate or Panavia F cements.

Methods and Materials: Sixty‐three caries‐free extracted single‐rooted human teeth were randomly divided into three groups of 21. Root canal preparations were standardized for all 63 teeth. Clinical protocols for fabricating and cementing dowel and core restorations were examined, comparing zinc phosphate and Panavia F resin cements. Direct dowel patterns were fabricated using the Para Post system and cast in a noble metal alloy. Group I dowel spaces were lubricated with GC lubricant prior to dowel pattern fabrication and cleaned with Cavidry solvent before cementing the cast dowel and core with zinc phosphate cement. Group II dowel spaces were rinsed with water only prior to dowel pattern fabrication. The dowels and cores in this group were cemented with Panavia F resin cement. Group III dowel spaces were lubricated with GC lubricant prior to dowel pattern fabrication; the dowel spaces were cleaned with Cavidry solvent before the cast dowel and cores were cemented with Panavia F cement. The tensile force necessary to remove the cast dowel and cores was determined using a universal testing machine. Results were statistically analyzed using one‐way ANOVA and Tukey's HSD test.

Results: The dowels and cores in Group I had significantly higher retentive values than either of the two Panavia F groups (p≤ 0.001). No difference in retentive values (p > 0.05) was found between dowels luted with either of the lubricating agents in the Panavia F groups.

Conclusions: Zinc phosphate cement had higher retentive values when cementing cast dowel and cores than Panavia F. The type of lubricant used for the resin dowel fabrication (water or GC lubricant that was removed with a solvent) had no effect on the retention of cast dowels cemented with Panavia F.
Compliance of Resilient Denture Liners Immersed in Effervescent Denture Cleansers
Authors: Benting Douglas G. , Pesun Igor J. , Hodges James
Published: September 2005

Purpose: Six resilient denture liners (RDL) were exposed to two immersion effervescent denture cleansers to evaluate change in compliance over a simulated 1 year time interval.

Materials and Methods: Ten samples of each material, Molloplast B, Mollosil, MPDS‐SL, Permasoft, Softline, and Sofreliner were exposed to either Fixodent or Efferdent denture cleanser. A cyclic load was applied in a squarewave fashion to derive a load displacement curve to measure compliance at 0, 7, 30, 180, and 360 simulated days.

Results: All 12 of the material/cleanser combinations demonstrated a significant change in compliance at each time interval relative to baseline. Mollosil had the greatest increase in flexibility from baseline, and MPDS‐SL had the smallest increase in flexibility. In general, chairside materials demonstrated greater change in compliance from baseline compared to laboratory materials. Materials subjected to Fixodent cleanser, when averaged over time, were significantly more flexible than materials exposed to Efferdent cleanser.

Conclusions: Exposure of resilient soft liners to two common cleansers resulted in a significant increase in flexibility. This change in flexibility depended slightly, though significantly, on the type of cleanser, and appeared to be more significant with time. In general, chairside materials seemed to change more than laboratory‐processed liners. The exception was Permasoft that was fabricated as a laboratory material but behaved like a chairside material.

Clinical Significance: The initiator of the polymerization reaction rather than the mode of polymerization may be more important in predicting a change in the flexibility of RDLs. Constituents within the oral environment may be more responsible for changes in RDL flexibility than denture cleansers.
Complete Denture Education in U.S. Dental Schools
Authors: Petropoulos Vicki C. , Rashedi Behnoush
Published: September 2005

Purpose: In 2001, a survey of U.S. dental schools was conducted to determine curricular content, teaching philosophies, and techniques used in clinical complete denture programs.

Materials and Methods: The questionnaire was mailed to the chairperson of the prosthodontic/restorative department of 54 U.S. dental schools. Of these, 44 schools returned the completed survey, resulting in a response rate of 82%. The mean, median, and range of responses were computed where applicable.

Results: Results from this survey show that a large majority of schools are using similar materials in clinical complete denture treatment: irreversible hydrocolloid for preliminary impression (87%); light‐cured composite resin for record base fabrication (70%); a semiadjustable articulator (98%); and semianatomic posterior tooth form used exclusively or in combination with other tooth forms (75%). In addition, a large majority of schools are using similar techniques in clinical complete denture treatment: use of a protrusive record (80%); use of extra‐oral measurements, speech, and esthetics for establishing the occlusal vertical dimension (59%); use of the conventional compression molding method for processing complete dentures (82%); occlusal equilibration and face‐bow preservation (75%); and the clinical remount procedure (91%). A quality control program is present for cases sent to and returned from the laboratory in 73% and 84% of responding schools, respectively.

Conclusions: Clinical complete denture predoctoral programs vary from school to school, yet a large percentage of schools agree on many topics. Only 55% of schools reported incorporating new educational materials such as the use of dental implants and treatment of patients with implant‐retained overdentures at the predoctoral level. Sixteen percent are allowing students to graduate without a set number of required complete dentures as has traditionally been the case. Sixteen percent are using newer techniques such as injection molding and microwave processing technique in addition to the conventional processing technique.
Moisture Effect on Polyether and Polyvinylsiloxane Dimensional Accuracy and Detail Reproduction
Authors: Walker Mary P. , Petrie Cynthia S. , Haj‐Ali Reem , Spencer Paulette , Dumas Chris , Williams Karen
Published: September 2005

Purpose: This investigation evaluated and compared the dimensional accuracy and surface detail reproduction of two hydrophilic polyvinylsiloxane (PVS) and two polyether (PE) impression materials when used under dry and moist conditions.

Methods: Impressions were made of stainless steel dies as described in ANSI/ADA specification no. 19, with two vertical and three horizontal lines inscribed on the die superior surface. Impressions were made under dry and moist conditions (17 impressions per condition for each material). Dimensional accuracy was measured by comparing the average length of the middle horizontal line in each impression with the same line on the metal die using a measuring microscope with an accuracy of 0.001 mm. Surface detail reproduction was evaluated by using criteria similar to ADA specification no. 19: continuous replication of at least two of the three horizontal lines.

Results: The mean percent dimensional change and SD values ranged from −0.135% (0.035) to 0.053% (0.031). A two‐way analysis of variance (ANOVA) indicated that moisture did not cause significant adverse effects on the dimensional accuracy of any material (p > 0.05); however, significant differences were found between the materials (p < .05). The surface detail evaluation indicated that moisture had a significant effect on detail reproduction of PVS materials (Pearson's Chi square, p < 0.05). Under dry conditions, all materials produced satisfactory detail reproduction 100% of the time; however, under moist conditions, only 29% of Aquasil and Genie Ultra PVS impressions produced satisfactory detail reproduction, while 100% of Permadyne Garant and Impregum Penta Soft PE impressions still met the surface detail criteria.

Conclusions: Although moisture may not adversely affect the dimensional accuracy of either PE or hydrophilic PVS material, the evidence suggests that PE material is more likely to produce impressions with superior detail reproduction in the presence of moisture.
Territory, Contiguity, and International Conflict: Assessing a New Joint Explanation
Authors: Senese Paul D.
Published: September 2005

Beginning with two prominent explanations of international conflict—one based on contiguity and the other on territory—I develop a new joint account that provides two important advancements over the prior explanations. I then test the expectations of this joint account on dispute and war onset for all dyad years from 1919 to 1995. I find strong support for its predictions at the dispute stage and partial support at the war stage, including marked evidence of contingency between contiguity and territory. The results also show territory to be a more consistent engine of conflict than contiguity, especially at the war onset stage. Further, the findings provide insights into the effects of contiguity among nonterritorial disagreements, as well as the effects of territorial strife among noncontiguous pairs. Thus, this investigation clarifies the relative importance of both territory and contiguity within any geography‐based explanation of conflict behavior, and therefore has broadly interesting implications.
Government Partisanship, Elections, and the Stock Market: Examining American and British Stock Returns, 1930–2000
Authors: Leblang David , Mukherjee Bumba
Published: September 2005

We construct a model of speculative trading to examine how the mean and volatility of stock prices is affected both by government partisanship and by traders' expectations of electoral victory by the right‐wing or left‐wing party. Our model predicts that rational expectations of higher inflation under left‐wing administrations lowers the volume of stocks traded in the stock market. The decline in trading volume leads to a decrease in the mean and volatility of stock prices not only during the incumbency of left‐wing governments, but also when traders expect the left‐wing party to win elections. Conversely, expectation of lower inflation under right‐wing administrations leads to higher trading volume. This leads to an increase in the mean and volatility of stock prices during the tenure of right‐wing governments and when traders anticipate the right‐wing party to win elections. Daily and monthly data from U.S. and British equity markets between 1930 and 2000 statistically corroborate the predictions from our formal model.
Rousseau's Politic Argument in the Discourse on the Sciences and Arts
Authors: Campbell Sally Howard , Scott John T.
Published: September 2005

Rousseau's arguments often turn on a correct understanding of the relationship between cause and effect. We argue that the principal cause‐effect argument of the Discourse is actually the opposite of the one Rousseau appears to posit in his work. Whereas he initially seems to argue that the sciences and arts corrupt morals, his ultimate argument is that the corruption of morals is the cause of the advancement of the sciences and arts and of their corrupting effects. Behind both moral corruption and the advancement of the sciences and arts lies a more remote cause: human pride and the unequal social and political conditions that result from pride and then foster it. Rousseau takes advantage of this complex causal relationship by simultaneously presenting an initial causal argument that gives his essay its paradoxical character and obscuring the ultimate causal argument of the work because of its implications as a critique of political authority and inequality.
Women Ministers in Latin American Government: When, Where, and Why?
Authors: Escobar‐Lemmon Maria , Taylor‐Robinson Michelle M.
Published: September 2005

We examine factors that affect the supply of and demand for female cabinet ministers in Latin America and seek to understand the frequency with which women join cabinets and the types of portfolios women receive. Our analysis covers 18 Latin American democracies from 1980 to 2003. We find that presidents from parties of the left appoint more women. Increases in the percentage of women in the legislature and higher human development correlate with more women in the cabinet. Intense partisan competition increases the likelihood that a cabinet will contain a woman. Women are more likely to receive high‐prestige cabinet posts from leftist presidents and when the percentage of women in the legislature increases. In addition, an international diffusion effect appears to explain the rapid expansion of women in Latin American cabinets.
The Indirect Effects of Discredited Stereotypes in Judgments of Jewish Leaders
Authors: Berinsky Adam J. , Mendelberg Tali
Published: September 2005

Can stereotypes of ethnic groups have an indirect impact on voters' judgments even if voters reject them? We examine the case of Jewish leaders and hypothesize that acceptable political stereotypes (Jews are liberal) are linked in voters' minds to unacceptable social stereotypes (Jews are shady); consequently, a cue to the candidate's shadiness works indirectly by increasing the perception that the candidate is liberal, even as the shady cue is rejected. Using three national survey‐experiments we randomly varied a candidate's Jewish identity, ideology, and shadiness. The cue to the rejected social stereotype indeed activates the more legitimate political stereotype. Moreover, voters give more weight to the candidate's perceived liberalism in their evaluation. Consequently, the candidate's support suffers. However, when the candidate takes a more extreme ideological position on issues, the effects disappear. The indirect influence of discredited stereotypes and the limits of those stereotypes have implications for our understanding of voting and of the legacies of discrimination.
Political Choice, Public Policy, and Distributional Outcomes
Authors: Kelly Nathan J.
Published: September 2005

I address the functioning of the U.S. governing system by analyzing distributional outcomes from 1947 to 2000. The key question is whether public policy influences distributional outcomes. The macropolitics model and power resource theory suggest that left policies should equalize the distribution of income. I utilize single equation error correction models to assess the impact of policy on income inequality through two mechanisms—market conditioning and redistribution. Since nearly every government action influences markets in some way, I examine policy in the aggregate rather than focusing only on policies explicitly designed to redistribute income. The analysis indicates that policy influences inequality through both mechanisms, with left policy producing more equality. The results are consistent with power resource theory and strongly support the macropolitics model. Furthermore, I find that market conditioning is as important as, and works in tandem with, explicit redistribution.
Party Identification and Core Political Values
Authors: Goren Paul
Published: September 2005

Party identification and core political values are central elements in the political belief systems of ordinary citizens. Are these predispositions related to one another? Does party identification influence core political values or are partisan identities grounded in such values? This article draws upon theoretical works on partisan information processing and value‐based reasoning to derive competing hypotheses about whether partisanship shapes political values or political values shape partisanship. The hypotheses are tested by using structural equation modeling techniques to estimate dynamic models of attitude stability and constraint with data from the 1992–94–96 National Election Study panel survey. The analyses reveal that partisan identities are more stable than the principles of equal opportunity, limited government, traditional family values, and moral tolerance; party identification constrains equal opportunity, limited government, and moral tolerance; and these political values do not constrain party identification.
Political Institutions and Economic Performance: The Effects of Accountability and Obstacles to Policy Change
Authors: Hicken Allen , Satyanath Shanker , Sergenti Ernest
Published: September 2005

Numerous analyses have been conducted on how political institutions affect economic performance. In recent years the emphasis has been on a causal logic that emphasizes institutional obstacles to policy change, such as those presented by multiple veto points. This has especially been the case when it comes to the important question of how political institutions influence governments' responses to exogenous economic shocks. We make the case for a substantial broadening of focus and show that when it comes to a major type of exogenous shock, a forced exchange‐rate devaluation, variations in the breadth of accountability of the chief executive are more robustly associated with the post‐shock growth recovery than variations in obstacles to policy change. We first argue that the size of the winning coalition will be positively associated with growth recoveries following forced devaluations. We then use a newly developed measure of the size of the winning coalition to test our claim. Our statistical analysis is based on a study of the responses of 44 countries to forced exchange‐rate devaluations in the late 1990s.
Candidate Qualities through a Partisan Lens: A Theory of Trait Ownership
Authors: Hayes Danny
Published: September 2005

UsingPetrocik's (1996)theory of issue ownership as a point of departure, I develop and test a theory of “trait ownership” that provides an explanation for the origins of candidate trait perceptions and illustrates an important way that candidates affect voters. Specifically, I argue for a direct connection between the issues owned by a political party and evaluations of the personal attributes of its candidates. As a result, the American public views Republicans as stronger leaders and more moral, while Democrats hold advantages on compassion and empathy. I also draw on “expectations gap” arguments from psychology and political science to demonstrate how a candidate may gain an electoral advantage by successfully “trespassing” on his opponent's trait territory. National Election Studies data from the 1980–2004 presidential elections are used to demonstrate the existence, durability, and effects of trait ownership in contemporary American political campaigns.
Processing and Properties of TiB2 with MoSi2 Sinter‐additive: A First Report
Authors: Murthy T. S. R. Ch. , Basu B. , Balasubramaniam R. , Suri A. K. , Subramanian C. , Fotedar R. K.
Published: September 2005

The densification of non‐oxide ceramics like titanium boride (TiB2) has always been a major challenge. The use of metallic binders to obtain a high density in liquid phase‐sintered borides is investigated and reported. However, a non‐metallic sintering additive needs to be used to obtain dense borides for high‐temperature applications. This contribution, for the first time, reports the sintering, microstructure, and properties of TiB2 materials densified using a MoSi2 sinter‐additive. The densification experiments were carried out using a hot‐pressing and pressureless sintering route. The binderless densification of monolithic TiB2 to 98% theoretical density with 2–5 μm grain size was achieved by hot pressing at 1800°C for 1 h in vacuum. The addition of 10–20 wt% MoSi2 enables us to achieve 97%–99%ρth in the composites at 1700°C under similar hot‐pressing conditions. The densification mechanism is dominated by liquid‐phase sintering in the presence of TiSi2. In the pressureless sintering route, a maximum of 90%ρth is achieved after sintering at 1900°C for 2 h in an (Ar+H2) atmosphere. The hot‐pressed TiB2–10 wt% MoSi2 composites exhibit high Vickers hardness (∼26–27 GPa) and modest indentation toughness (∼4–5 MPa·m1/2).