bluuebunny/crossref_metadata_2025 huggingface dataset:
Estimation of the segregation potential of fine-grained soils using the frost heave response of two reference soils
Authors: Konrad Jean-Marie
Published: March 2005

The frost heave response of quarry fines from several locations in the Province of Quebec was studied in the laboratory using one-dimensional step-freezing tests with free access to water. Comparison of the segregation potential values obtained from these tests with available data on fine-grained soils revealed the importance of including clay mineralogy and overburden effects in any predictive empirical relationship, especially when fines are nonclays. A new approach is presented to estimate segregation potential values using the frost heave response of two reference soils. The reference characteristics consist of a relationship between segregation potential at zero overburden pressure, specific surface area, and average grain size of the fines fraction for two artificial soil mixtures in which the clay mineral is poorly crystallized kaolinite. The prediction of segregation potential values using the reference frost heave characteristics approach is more robust and reliable than other empirical approaches that do not specifically distinguish between clay and nonclay fines. Furthermore, the new approach was also efficient for the assessment of frost susceptibility of well-graded glacial tills.Key words: fine grained, soil, mineralogy, laboratory, fines, clay, nonclay.
Autocrine production of prostaglandin F2α enhances phenotypic transformation of normal rat kidney fibroblasts
Authors: Harks E. G. A. , Peters P. H. J. , van Dongen J. L. J. , van Zoelen E. J. J. , Theuvenet A. P. R.
Published: March 2005

We have used normal rat kidney (NRK) fibroblasts as an in vitro model system to study cell transformation. These cells obtain a transformed phenotype upon stimulation with growth-modulating factors such as retinoic acid (RA) or transforming growth factor-β (TGF-β). Patch-clamp experiments showed that transformation is paralleled by a profound membrane depolarization from around −70 to −20 mV. This depolarization is caused by a compound in the medium conditioned by transformed NRK cells, which enhances intracellular Ca2+ levels and thereby activates Ca2+-dependent Cl− channels. This compound was identified as prostaglandin F2α (PGF2α) using electrospray ionization mass spectrometry. The active concentration in the medium conditioned by transformed NRK cells as determined using an enzyme immunoassay was 19.7 ± 2.5 nM ( n = 6), compared with 1.5 ± 0.1 nM ( n = 3) conditioned by nontransformed NRK cells. Externally added PGF2α was able to trigger NRK cells that had grown to density arrest to restart their proliferation. This proliferation was inhibited when the FP receptor (i.e., natural receptor for PGF2α) was blocked by AL-8810. RA-induced phenotypic transformation of NRK cells was partially (∼25%) suppressed by AL-8810. Our results demonstrate that PGF2α acts as an autocrine enhancer and paracrine inducer of cell transformation and suggest that it may play a crucial role in carcinogenesis in general.
Volcanic and Solar Forcing of the Tropical Pacific over the Past 1000 Years
Authors: Mann Michael E. , Cane Mark A. , Zebiak Stephen E. , Clement Amy
Published: March 2005

The response of El Niño to natural radiative forcing changes over the past 1000 yr is investigated based on numerical experiments employing the Zebiak–Cane model of the tropical Pacific coupled ocean–atmosphere system. Previously published empirical results demonstrating a statistically significant tendency toward El Niño conditions in response to past volcanic radiative forcing are reproduced in the model experiments. A combination of responses to past changes in volcanic and solar radiative forcing closely reproduces changes in the mean state and interannual variability in El Niño in past centuries recorded from fossil corals. The dynamics of El Niño thus appear to have played an important role in the response of the global climate to past changes in radiative forcing.
Qualitative Teamwork Issues and Strategies: Coordination Through Mutual Adjustment
Authors: Hall Wendy A. , Long Bonita , Bermbach Nicole , Jordan Sharalyn , Patterson Kathryn
Published: March 2005

Multidisciplinary research teams that include faculty, students, and volunteers can be challenging and enriching for all participants. Although such teams are becoming commonplace, minimal guidance is available about strategies to enhance team effectiveness. In this article, the authors highlight strategies to guide qualitative teamwork through coordination of team members and tasks based on mutual adjustment. Using a grounded theory exemplar, they focus on issues of (a) building the team, (b) developing reflexivity and theoretical sensitivity, (c) tackling analytic and methodological procedures, and (d) developing dissemination guidelines. Sharing information, articulating project goals and elements, acknowledging variation in individual goals, and engaging in reciprocity and respectful collaboration are key elements of mutual adjustment. The authors summarize conclusions about the costs and benefits of the process.
Sources of Practice Knowledge Among Nurses
Authors: Estabrooks Carole A. , Rutakumwa William , O’Leary Katherine A. , Profetto-McGrath Joanne , Milner Margaret , Levers Merry Jo , Scott-Findlay Shannon
Published: March 2005

Several studies have been published listing sources of practice knowledge used by nurses. However, the authors located no studies that asked clinicians to describe comprehensively and categorize the kinds of knowledge needed to practice or in which the researchers attempted to understand how clinicians privilege various knowledge sources. In this article, the authors report findings from two large ethnographic case studies in which sources of practice knowledge was a subsidiary theme. They draw on data from individual and card sort interviews, as well as participant observations, to identify nurses’ sources of practice knowledge. Their findings demonstrate that nurses categorize their sources of practice knowledge into four broad groupings: social interactions, experiential knowledge, documents, and a priori knowledge. The insights gained add new understanding about sources of knowledge used by nurses and challenge the disproportionate weight that proponents of the evidence-based movement ascribe to research knowledge.
Extending a Practical Method for Developing Alternate Test Forms Using Independent Sets of Items
Authors: Oswald Frederick L. , Friede Alyssa J. , Schmitt Neal , Kim Brian H. , Ramsay Lauren J.
Published: March 2005

This study describes alternate test form development for a Situational Judgment Inventory (SJI) predicting college performance. Principal axis factor analysis of responses to the SJI lent support for a general factor, yet each SJI form sampled items across 12 distinct rationally derived content areas. The first step of developing alternate forms involved random and representative sampling of SJI items across each content area, creating a large number of preliminary 36-item SJI test forms. Gibson and Weiner (1998) provided criteria for selecting alternate forms; however, the authors of the present study extended this approach in the next step of selecting alternate forms based on their estimated criterion-related validity with grade point average. Results provide initial support for the 144 alternate forms generated. This general approach reflects a practical and methodologically sound means of developing alternate forms of types of measures that are rationally heterogeneous yet empirically homogeneous.
Complementary role of CD4+CD25+ regulatory T cells and TGF-β in oral tolerance
Authors: Chung Yeonseok , Lee Seung-Ho , Kim Dong-Hyeon , Kang Chang-Yuil
Published: March 2005

CD4+CD25+ regulatory T cells are thought to be generated in the periphery as well as in the thymus. We sought to determine the roles played by CD4+CD25+ T cells and transforming growth factor-β (TGF-β) in the induction and maintenance of tolerance generated by oral antigens in BALB/c mice. We found that oral administration of a high dose of ovalbumin (OVA) suppressed OVA-specific proliferation and antibody production in BALB/c mice depleted of CD25+ cells. In contrast, the unresponsiveness induced by lower doses of OVA was only partially blocked by CD25 depletion prior to feeding. Depletion of CD4+CD25+ cells after mice were orally tolerized did not reverse the tolerant status, indicating that these cells were not required to maintain the established tolerance. Furthermore, the induction of oral tolerance was not hampered by the administration of TGF-β-neutralizing antibodies. However, in mice depleted of CD25+ cells, anti-TGF-β-neutralizing antibodies blocked the induction of tolerance, regardless of whether the mice followed the high- or low-dose regimens of oral OVA. CD25 depletion together with TGF-β neutralization led the expansion of OVA-specific CD4 T cells against the subsequent antigen challenge, and each treatment alone did not. Our findings indicate that CD4+CD25+ T cells and TGF-β play a complementary role in the induction of oral tolerance, at least in part, by regulating the expansion of antigen-specific CD4 T cells.
Aminopeptidase N (CD13) functionally interacts with FcγRs in human monocytes
Authors: Mina-Osorio Paola , Ortega Enrique
Published: March 2005

Aminopeptidase N (E.C. 3.4.11.2) is a membrane-bound metalloproteinase expressed in many tissues. Although its cytoplasmic portion has only eight amino acids, cross-linking of CD13 by monoclonal antibodies (mAb) has been shown to trigger intracellular signaling. A functional association between CD13 and receptors for immunoglobulin G (FcγRs) has been proposed. In this work, we evaluated possible functional interactions between CD13 and FcγRs in human peripheral blood monocytes and in U-937 promonocytic cells. Our results show that during FcγR-mediated phagocytosis, CD13 redistributes to the phagocytic cup and is internalized into the phagosomes. Moreover, modified erythrocytes that interact with the monocytic cell membrane through FcγRI and CD13 are ingested simultaneously, more efficiently than those that interact through the FcγRI only. Also, co-cross-linking of CD13 with FcγRI by specific mAbs increases the level and duration of Syk phosphorylation induced by FcγRI cross-linking. Finally, FcγRI and CD13 colocalize in zones of cellular polarization and coredistribute after aggregation of either of them. These results demonstrate that CD13 and FcγRI can functionally interact on the monocytic cell membrane and suggest that CD13 may act as a signal regulator of FcγR function.
Laboratory Calibration of Earth Pressure Cells
Authors: Labuz JF , Theroux B
Published: March 2005

The objective of this study was to design a simple apparatus for laboratory calibration of diaphragm type earth pressure cells (EPC). A new testing device was fabricated to permit the application of normal stress to the EPC using various types of soil and load configurations. With respect to fluid pressure, the response of the EPC can be different for the simplest earth pressure conditions because of an arching effect or nonuniform contact stress. For an EPC with a rigid outer rim, sensitivities computed from soil calibrations were lower than those determined from fluid calibrations by about 20 %.
P-Wave Reflection Imaging
Authors: Lee J-S , Carlos Santamarina J
Published: March 2005

The reflection of elastic waves from interfaces is a robust phenomenon extensively used by animals (bats and dolphins), nondestructive techniques, and medical diagnosis. This study addresses the design and implementation of P-wave reflection imaging to evaluate the internal variability in small-scale submerged, soil models. The performance of this technology depends on fundamental aspects of P-wave propagation in soils, the selection of optimal P-wave transducers, and the development of an adequate test methodology. Design issues include transducer directivity, noise, axial resolution, near field effects, and proper thickness of the coupling water layer. The operating frequency is determined by transducer selection and affects the axial and lateral resolution, skin depth, near field, and divergence; high damping transducers permit higher axial resolution. In addition, data gathering must take into consideration temporal and spatial aliasing. Results show that P-wave reflection is a valuable tool to detect subsurface anomalies and layers, to assess phenomena such as slurry sedimentation, and to monitor the evolution of subsurface structures such as soil layers during liquefaction. Gradual changes in impedance, such as in slurry sedimentation, may prevent reflections.
Characterization of Crack Length Measurement Methods for Flat Fracture with Tunneling
Authors: James MA , Newman JC
Published: March 2005

This paper compares area-average and unloading compliance crack-growth values with experimental crack-front shapes recorded at various stages of crack growth during fracture tests conducted on 2024-T351 aluminum alloy plate. Crack-front shapes were determined by fracturing the specimen up to a predetermined amount of crack growth and fatigue cycling the specimen for about 4000 cycles at a high stress ratio to mark the crack-front location. For each shape, the area-average and unloading compliance crack lengths were determined. Boundary collocation results provide an approximation to the δ5 unloading compliance crack length. The crack tunneling results show that the area-average technique produces crack-length measurements more representative of the straight-front finite element analyses than optical based surface measurements. The δ5 technique is significantly more sensitive to tunneling than the CMOD technique and is easier to apply than the area-average technique.
Identification of a Physical Model to Evaluate Rutting Performance of Asphalt Mixtures
Authors: Drakos CA , Roque R , Birgisson B , Novak M
Published: March 2005

The objective of this study is to identify a physical model that can provide reliable predictions about a mixture's ability to resist permanent deformation under realistic stress states. Key differences were identified between stress states under the existing Asphalt Pavement Analyzer (APA) loading device (hose) and stress states under radial truck tires, which may indicate potentially different rutting mechanisms. It was shown that the APA hose was not capturing the critical lateral stresses found to be detrimental to rutting and cracking of HMA pavements. A new loading device (rib) was designed and constructed for use in the APA that more closely represents stress states found under radial tires.

Contact-stress measurements under the two loading devices — hose and rib — showed that the rib was able to reproduce the lateral stresses found under individual ribs on a radial-tire tread. Subsequent finite element modeling also showed that the rib appeared to generate similar shear stress patterns to those found under the modeled radial-tire load.

A new method was developed to measure deformations on the surface of APA specimens, where a contour gauge was used to record and store the entire surface profile of the sample throughout the progress of the test. An area-change parameter, which reflects volume change, was introduced to calculate the volumetric changes in the specimen. The area-change parameter can be used to determine whether specimen rutting is primarily due to shear instability or consolidation.

Two mixtures of known field performance — poor and good — were tested to evaluate the test's ability to predict performance with the new loading device and the new measurement and interpretation system. Results showed that the new system (loading strip and profile measurement method) appears to have greater potential of evaluating a mixture's potential for instability rutting than the original (hose and single rut-depth measurement) configuration.
Simulation of Cold Pilgering Process by a Generalized Plane Strain FEM
Authors: Harada M , Honda A , Toyoshima S
Published: March 2005

In order to attain a defect-free operation in the cold pilgering process, one must understand the material behavior through both experimental and computational study, optimization of the tool profile (mandrel and rolls), and appropriate selection of the tool material. Until now, several simplified computational methods have been presented, because 3-dimensional analysis is still far away in such a complicated forming process. In this paper, a generalized plane strain model has been employed for the simulations of cold pilgering of fuel cladding for nuclear applications. In this model, the tube material is considered to be viscoplastic at the loading stage of pilgering and totally elastic after every stroke. Therefore, considering the tube springs back after each stroke, it can be investigated how the tube shape affects deformation in the next pilgering stroke. A cold pilgering of zirconium alloy by two types of tools has been computed and compared. Moreover, computed results are compared with experimental results. Throughout the studies, the effect of tube spring back and the effect of design parameters on the deformation behavior are demonstrated.
Effects of Neutron Dose, Dose Rate, and Irradiation Temperature on the Irradiation Embrittlement of a Low-Copper Reactor Pressure Vessel Steel
Authors: Kasada R , Kudo T , Kimura A , Matsui H , Narui M
Published: March 2005

A series of irradiation experiments to investigate the effects of neutron fluence and flux on reactor pressure vessel (RPV) steels has been performed using the Japan Material Testing Reactor (JMTR). The irradiation temperature has been precisely controlled at 290°C within an error of ±2°C during reactor operation. The neutron fluence and flux ranged from 9.3 × 1017 to 1.1 × 1020 n/cm2 and from 1.4 × 1011 to 6.3 × 1013 n/cm2/s, respectively. The material used in the present study was an A533B RPV steel in which the copper and phosphorous concentrations are 0.03 and 0.002 wt%, respectively. Charpy impact test results with one-third sized specimens showed no dose-rate dependence. Microstructural observation revealed that a higher irradiation temperature at around 340°C resulted in formation of rather large dislocation loops and smaller microvoids.
Use of the Irradiation-Thermal Creep Model of Zr-1% Nb Alloy Cladding Tubes to Describe Dimensional Changes of VVER Fuel Rods
Authors: Rogozyanov AY , Smirnov AV , Kanashov BA , Polenok VS , Nuzhdov AA
Published: March 2005

The objective of this work was firstly to categorize the data on dimensional change of the VVER fuel rods and to identify the primary variables influencing performance, and secondly to benchmark the irradiation-thermal creep model for Zr-1 % Nb alloy cladding tubes against the VVER fuel rod dimensional changes data. The creep model was developed using the results of in-pile and out-of-pile tests of tube specimens.

Data arrays on the change of fuel rod diameter and length were obtained during examination of eight VVER-440 fuel assemblies and 16 VVER-1000 fuel assemblies. Qualitative analysis was performed of the measurement results presented as dependencies of averaged axial strain on burnup.

Similar calculated dependencies were obtained using the creep model considering the irradiation growth strain. The quantitative analysis showed that differences between the calculated and actual dimensional changes of the fuel rods did not exceed 3–4.5 % for VVER-440 and 7 % for VVER-1000.
A Procedure for Calculation of Torque Specifications for Bolted Joints with Prevailing Torque
Authors: Reiff JD
Published: March 2005

This paper presents procedures developed for the calculation of the coefficient of friction of bolt/nut assemblies and for the calculation of torque specifications, which include the case where the fasteners have prevailing torque.
Shear Strength of Structural Composite Lumber Using Torsion Tests
Authors: Gupta R , Siller T
Published: March 2005

Torsion tests were used to determine the shear strength of full-size structural composite lumber (SCL). Eighty-five rectangular specimens of laminated strand lumber (LSL), laminated veneer lumber (LVL), and parallel strand lumber (PSL) were tested. LSL failed along the strand (LT Plane) and in a brittle manner. LVL and PSL failed across the veneer/strand (LR plane) and in a ductile manner. Different failure modes were observed due to the differences in the shear moduli in two longitudinal planes (GLT and GLR). Based on orthotropic theory, the shear strength of LSL, LVL, and PSL is 6.43 MPa (TLR), 7.96 MPa (TLT), and 6.82 MPa (TLT), respectively. Based on the results of this study, the torsion test is recommended as a standard method for determining the pure shear strength of full-size SCL, since it is the only known test method to date that imposes a state of pure shear stress in the specimens.
Conversion of Elongation Values for Cold-Rolled Low Carbon Steel Sheets
Authors: Yebuah R , Tonkovic M , Kastelec S
Published: March 2005

It is often difficult or impossible to prepare tension test pieces from flat steel products to specified standard size due to inadequate sample piece size. Hence several sizes of test pieces yielding different gage lengths are envisaged. However, the value of the total elongation beyond maximum stress in tension testing depends on the gage length due to the effect of necking. Acceptance values of elongation at fracture for flat steel products are therefore specified together with corresponding gage lengths, e.g., 50 or 80 mm (fixed gage lengths) and k So (proportional gage lengths) where k takes the value of 4.00, 5.65, 8.16, or 11.30 and k √SO is the original cross-sectional area of the test piece in mm2. Methods for converting room temperature percentage elongation at fracture obtained on various proportional and nonproportional gage lengths to other gage lengths exist for austenitic, carbon, and low alloy steels as hot-rolled, normalized, annealed, etc., but not as cold-reduced. These methods are also not valid where the gage length is greater than 25 times √SO or where the width-to-thickness ratio of the test piece is greater than twenty. This paper proposes a possible solution for cold-rolled low carbon steel sheets of thickness less than 2.0 mm, which continue to be, if not the major, one of the major raw materials in the automotive industry. The solution lies in the modification of the exponent in the Oliver formula used for flat steel products other than cold-rolled low carbon steel sheets.
Characteristic Fatigue-Creep Interaction Behavior of an ESR-Cast-to-Shape Gas Turbine Disc Alloy with Coarse Branch Crystals at High Temperature
Authors: He Q
Published: March 2005

The fatigue-creep cycling life and crack propagation rate of a Fe-Ni-Cr alloy were obtained from a series of tests. The results show different dependence of the fatigue-creep interaction on the stress composition. Overlapping of alternative stress with mean stress at high temperature could cause fairly strong fatigue creep interaction and reduced fracture life, as compared with both pure fatigue and pure creep tests. The high temperature fatigue creep crack propagation rate, as a function of the stress intensity factor range (ΔK), could also be described by the Paris equation with varied exponent (m).
A Glial Endogenous Cannabinoid System Is Upregulated in the Brains of Macaques with Simian Immunodeficiency Virus-Induced Encephalitis
Authors: Benito Cristina , Kim Wong-Ki , Chavarría Iván , Hillard Ceceila J. , Mackie Ken , Tolón Rosa M. , Williams Ken , Romero Julián
Published: March 2005

Recent evidence supports the notion that the endocannabinoid system may play a crucial role in neuroinflammation. We explored the changes that some elements of this system exhibit in a macaque model of encephalitis induced by simian immunodeficiency virus. Our results show that profound alterations in the distribution of specific components of the endocannabinoid system occur as a consequence of the viral infection of the brain. Specifically, expression of cannabinoid receptors of the CB2subtype was induced in the brains of infected animals, mainly in perivascular macrophages, microglial nodules, and T-lymphocytes, most likely of the CD8 subtype. In addition, the endogenous cannabinoid-degrading enzyme fatty acid amide hydrolase was overexpressed in perivascular astrocytes as well as in astrocytic processes reaching cellular infiltrates. Finally, the pattern of CB1receptor expression was not modified in the brains of infected animals compared with that in control animals. These results resemble previous data obtained in Alzheimer's disease human tissue samples and suggest that the endocannabinoid system may participate in the development of human immunodeficiency virus-induced encephalitis, because activation of CB2receptors expressed by immune cells is likely to reduce their antiviral response and thus could favor the CNS entry of infected monocytes.
Structural Domains Involved in the Regulation of Transmitter Release by Synapsins
Authors: Hilfiker Sabine , Benfenati Fabio , Doussau Frédéric , Nairn Angus C. , Czernik Andrew J. , Augustine George J. , Greengard Paul
Published: March 2005

Synapsins are a family of neuron-specific phosphoproteins that regulate neurotransmitter release by associating with synaptic vesicles. Synapsins consist of a series of conserved and variable structural domains of unknown function. We performed a systematic structure-function analysis of the various domains of synapsin by assessing the actions of synapsin fragments on neurotransmitter release, presynaptic ultrastructure, and the biochemical interactions of synapsin. Injecting a peptide derived from domain A into the squid giant presynaptic terminal inhibited neurotransmitter release in a phosphorylation-dependent manner. This peptide had no effect on vesicle pool size, synaptic depression, or transmitter release kinetics. In contrast, a peptide fragment from domain C reduced the number of synaptic vesicles in the periphery of the active zone and increased the rate and extent of synaptic depression. This peptide also slowed the kinetics of neurotransmitter release without affecting the number of docked vesicles. The domain C peptide, as well as another peptide from domain E that is known to have identical effects on vesicle pool size and release kinetics, both specifically interfered with the binding of synapsins to actin but not with the binding of synapsins to synaptic vesicles. This suggests that both peptides interfere with release by preventing interactions of synapsins with actin. Thus, interactions of domains C and E with the actin cytoskeleton may allow synapsins to perform two roles in regulating release, whereas domain A has an actin-independent function that regulates transmitter release in a phosphorylation-sensitive manner.
Mutant Superoxide Dismutase 1 Forms Aggregates in the Brain Mitochondrial Matrix of Amyotrophic Lateral Sclerosis Mice
Authors: Vijayvergiya Chetan , Beal M. Flint , Buck Jochen , Manfredi Giovanni
Published: March 2005

An increasing body of evidence suggests that mitochondrial dysfunction plays an important role in the pathogenesis of familial amyotrophic lateral sclerosis associated with “gain of function” mutations in Cu/Zn superoxide dismutase 1 (SOD1). SOD1 is mostly a cytosolic protein, but a portion of SOD1 is localized in mitochondria of patients with familial amyotrophic lateral sclerosis and transgenic mouse models of the disease. Despite the finding that mutant SOD1 localizes in mitochondria, the pathogenic significance of the mitochondrial mutant SOD1 remains to be elucidated. Here, we demonstrate that both wild-type and mutant human SOD1 accumulate in brain mitochondria of transgenic mice and that SOD1 displays a very complex intramitochondrial compartmentalization. For the first time, we show that, in addition to being in the mitochondrial outer membrane and intermembrane space, SOD1 is also localized in the mitochondrial matrix. Importantly, we show that aberrant SOD1 macromolecular aggregates are formed in the matrix of brain mitochondria. This suggests that mutant SOD1 in the brain mitochondrial matrix is misfolded and prone to aggregation, which may contribute to selective neuronal degeneration.
Microglial Expression of the B7 Family Member B7 Homolog 1 Confers Strong Immune Inhibition: Implications for Immune Responses and Autoimmunity in the CNS
Authors: Magnus Tim , Schreiner Bettina , Korn Thomas , Jack Carolyn , Guo Hong , Antel Jack , Ifergan Igal , Chen Lieping , Bischof Felix , Bar-Or Amit , Wiendl Heinz
Published: March 2005

Inflammation of the CNS is usually locally limited to avoid devastating consequences. Critical players involved in this immune regulatory process are the resident immune cells of the brain, the microglia. Interactions between the growing family of B7 costimulatory ligands and their receptors are increasingly recognized as important pathways for costimulation and/or inhibition of immune responses.

Human and mouse microglial cells constitutively express B7 homolog 1 (B7-H1)in vitro. However, under inflammatory conditions [presence of interferon-γ (IFN-γ) or T-helper 1 supernatants], a significant upregulation of B7-H1 was detectable. Expression levels of B7-H1 protein on microglial cells were substantially higher compared with astrocytes or splenocytes. Coculture experiments of major histocompatibility complex class II-positive antigen-presenting cells (APC) with syngeneic T cells in the presence of antigen demonstrated the functional consequences of B7-H1 expression on T-cell activation. In the presence of a neutralizing anti-B7-H1 antibody, both the production of inflammatory cytokines (IFN-γ and interleukin-2) and the upregulation of activation markers (inducible costimulatory signal) by T cells were markedly enhanced. Interestingly, this effect was clearly more pronounced when microglial cells were used as APC, compared with astrocytes or splenocytes. Furthermore, B7-H1 was highly upregulated during the course of myelin oligodendrocyte glycoprotein-induced and proteolipid protein-induced experimental allergic encephalomyelitisin vivo. Expression was predominantly localized to areas of strongest inflammation and could be colocalized with microglial cells/macrophages as well as T cells.

Together, our data propose microglial B7-H1 as an important immune inhibitory molecule capable of downregulating T-cell activation in the CNS and thus confining immunopathological damage.
Stargazin Reduces Desensitization and Slows Deactivation of the AMPA-Type Glutamate Receptors
Authors: Priel Avi , Kolleker Alexander , Ayalon Gai , Gillor Moshe , Osten Pavel , Stern-Bach Yael
Published: March 2005

The AMPA-type glutamate receptors mediate the majority of the fast excitatory synaptic transmission and critically contribute to synaptic plasticity in the brain, hence the existence of numerous trafficking proteins dedicated to regulation of their synaptic delivery and turnover. Stargazin (also termed γ2) is a member of a recently identified protein family termed transmembrane AMPA receptor regulatory proteins (TARPs). TARPs physically associate with AMPA receptors and participate in their surface delivery and anchoring at the postsynaptic membrane. Here, we report that next to its trafficking roles, stargazin may also act as a positive allosteric modulator of AMPA receptor ion channel function. Coexpression of stargazin with AMPA receptor subunits, either inXenopusoocytes or in human embryonic kidney 293 cells, significantly reduced receptor desensitization in response to glutamate. Receptor deactivation rates were also slowed, and the recovery from desensitization was accelerated. Structurally, based on the data showing a tight correlation between desensitization and the stability of the AMPA receptor intradimer interface, we propose that binding of stargazin may stabilize the receptor conformation. Functionally, our data suggest that AMPA receptors complexed with stargazin (and possibly also with other TARPs) at the postsynaptic membrane are significantly more responsive to synaptically released glutamate compared with AMPA receptors lacking stargazin/TARP interaction. The putative existence of such two states of synaptic AMPA receptors, with and without stargazin/TARP binding, may provide a novel mechanism for regulation of excitatory synaptic strength during development and/or in synaptic plasticity in the adult brain.
β-Amyloid-Stimulated Microglia Induce Neuron Death via Synergistic Stimulation of Tumor Necrosis Factor α and NMDA Receptors
Authors: Floden Angela M. , Li Shanshan , Combs Colin K.
Published: March 2005

Although abundant reactive microglia are found associated with β-amyloid (Aβ) plaques in Alzheimer's disease (AD) brains, their contribution to cell loss remains speculative. A variety of studies have documented the ability of Aβ fibrils to directly stimulate microgliain vitroto assume a neurotoxic phenotype characterized by secretion of a plethora of proinflammatory molecules. Collectively, these data suggest that activated microglia play a direct role in contributing to neuron death in AD rather than simply a role in clearance after plaque deposition. Although it is clear the Aβ-stimulated microglia acutely secrete toxic oxidizing species, the identity of longer-lived neurotoxic agents remains less defined. We used Aβ-stimulated conditioned media from primary mouse microglia to identify more stable neurotoxic secretions. The NMDA receptor antagonists memantine and 2-amino-5-phosphopetanoic acid as well as soluble tumor necrosis factor α (TNFα) receptor protect neurons from microglial-conditioned media-dependent death, implicating the excitatory neurotransmitter glutamate and the proinflammatory cytokine TNFα as effectors of microglial-stimulated death. Neuron death occurs in an oxidative damage-dependent manner, requiring activity of inducible nitric oxide synthase. Toxicity results from coincident stimulation of the TNFα and NMDA receptors, because stimulations of either alone are insufficient to initiate cell death. These findings suggest the hypothesis that AD brains provide the appropriate microglial-mediated inflammatory environment for TNFα and glutamate to synergistically stimulate toxic activation of their respective signaling pathways in neurons as a contributing mechanism of cell death.
The Slow Afterhyperpolarization in Hippocampal CA1 Neurons Covaries with Spatial Learning Ability in Aged Fisher 344 Rats
Authors: Tombaugh Geoffrey C. , Rowe Wayne B. , Rose Gregory M.
Published: March 2005

Rodents commonly exhibit age-related impairments in spatial learning tasks, deficits widely thought to reflect cellular or synaptic dysfunction in the hippocampus. Using whole-cell recordings, we examined the afterhyperpolarization (AHP) in CA1 pyramidal cells in hippocampal slices from young (4-6 months of age) and aged (24-26 months of age) Fisher 344 male rats that had been behaviorally characterized in the Morris water maze. The slow AHP (sAHP) recorded from learning-impaired aged rats (AI) was significantly larger than that seen in either age-matched unimpaired rats or young controls. Among aged rats, sAHP amplitude was inversely correlated with both acquisition and probe performance in the water maze. Action potential parameters among the three groups were similar, except for spike accommodation, which was more pronounced in the AI group. Intracellular application of the cAMP analog 8-CPT-cAMP suppressed the sAHP but failed to reveal any age- or performance-related differences in the medium AHP. 8-CPT-cAMP abolished the age-related difference in spike accommodation, whereas instantaneous firing frequency was unchanged. Calcium spikes were of similar amplitude in all three groups but were broader and had significantly larger tails in aged rats; these age-related changes could be mimicked in young neurons after exposure to BayK8644. The calcium spike among aged rats correlated with task acquisition in the maze but, unlike the sAHP, failed to correlate with probe performance. This is the first demonstration that sAHP amplitude covaries with spatial learning ability in aged rats, implying that CA1 excitability strongly influences certain aspects of cognitive function. Our findings also indicate that multiple processes, in addition to elevated calcium influx, conspire to induce cognitive decline during aging.
Plasticity in Primary Auditory Cortex of Monkeys with Altered Vocal Production
Authors: Cheung Steven W. , Nagarajan Srikantan S. , Schreiner Christoph E. , Bedenbaugh Purvis H. , Wong Andrew
Published: March 2005

Response properties of primary auditory cortical neurons in the adult common marmoset monkey (Callithrix jacchus) were modified by extensive exposure to altered vocalizations that were self-generated and rehearsed frequently. A laryngeal apparatus modification procedure permanently lowered the frequency content of the native twitter call, a complex communication vocalization consisting of a series of frequency modulation (FM) sweeps. Monkeys vocalized shortly after this procedure and maintained voicing efforts until physiological evaluation 5-15 months later. The altered twitter calls improved over time, with FM sweeps approaching but never reaching the normal spectral range. Neurons with characteristic frequencies <4.3 kHz that had been weakly activated by native twitter calls were recruited to encode self-uttered altered twitter vocalizations. These neurons showed a decrease in response magnitude and an increase in temporal dispersion of response timing to twitter call and parametric FM stimuli but a normal response profile to pure tone stimuli. Tonotopic maps in voice-modified monkeys were not distorted. These findings suggest a previously unrecognized form of cortical plasticity that is specific to higher-order processes involved in the discrimination of more complex sounds, such as species-specific vocalizations.
The Music of the Past in Modern Baltic Paganism
Authors: Strmiska Michael
Published: March 2005

Modern Baltic Paganism grew out of nineteenth- and twentieth-century folklore research into the folk music, folklore and traditional ethnic cultures of Latvia and Lithuania. Research into native Latvian daina and Lithuanian daino folk songs with their rustic beauty, symbolic richness, and intriguing linkages to ancient Indo-European cultures and religions generated a new sense of pride and ethnic identity among Latvians and Lithuanians. Spiritually inclined folklorists developed religious movements that recreated rituals and beliefs linked to the dainas and dainos. Repressed during Soviet times, these movements have reemerged and flourished in the post-Soviet period. There can be no doubt that music, which over the centuries has played such a crucial role in the transmission of Latvian and Lithuanian folk traditions including native Pagan religions, will remain front and center in the continuing evolution of modern Baltic Pagan religions in Latvia and Lithuania and beyond.
Mutational analysis of theTCOF1gene in 11 Japanese patients with Treacher Collins Syndrome and mechanism of mutagenesis
Authors: Horiuchi Katsumi , Ariga Tadashi , Fujioka Hirotaka , Kawashima Kunihiro , Yamamoto Yuhei , Igawa Hiroharu , Sugihara Tsuneki , Sakiyama Yukio
Published: March 2005

Treacher Collins Syndrome (TCS) (OMIM 154500) is a congenital, craniofacial disorder inherited as an autosomal dominant trait. The responsible gene for TCS,TCOF1, was mapped to 5q32‐33.1 and identified in 1996. Since then,TCOF1mutations in patients with TCS have been reported from Europe, North and South America, however, no TCS cases from an Asian country have been molecularly characterized. Here we report mutational analysis for 11 Japanese patients with TCS for the first time, and have identifiedTCOF1mutations in 9 of them. The mutations detected were various, but most likely all the mutations are predicted to result in a truncated gene product, known as treacle. One mutation frequently reported was included in our cases, but no missense mutations were detected. These findings are similar to those for the previous studies for TCS in other races. We have speculated about the molecular mechanisms of the mutations in most cases. Collectively, we have defined some of the characteristic molecular features commonly observed in TCS patients, irrespective of racial difference. © 2005 Wiley‐Liss, Inc.
Surnames in Argentina: A population study through isonymy
Authors: Dipierri J.E. , Alfaro E.L. , Scapoli C. , Mamolini E. , Rodriguez‐Larralde A. , Barrai I.
Published: March 2005

In order to study the isonymic structure of Argentina, the surname distributions of 22.6 million electors registered for the year 2001 were analyzed in the 24 districts (distritos) and 541 municipalities (municipios) of the country. The number of different surnames found was 414,441. Matrices of isonymic distances between districts were constructed and tested for correlation with the geographic distance between the capital towns of the districts. We found that, for the whole of Argentina, Euclidean distance was correlated with the log of geographic distance (r = 0.480 ± 0.067). A dendrogram of the 24 regions was built from the matrix of Euclidean distances, using the UPGMA method. The clusters identified by the dendrogram are coincident with conterminous geographical regions of the country. Random inbreeding calculated from isonymy, FST, was highest in La Rioja, Corrientes, and Santiago del Estero. It was lowest in the area of Buenos Aires and in the north‐central region of Santa Fé. Average Fisher's α for municipalities was 358; for districts, it was 422; and for Argentina as a unit, it was 602. The geographical distribution of α in 541 municipalities, high in the east and lower in the west of the country, is compatible with the settlement in the 20th century of subsequent waves of immigrants moving from the North Atlantic coast toward the foot of the Andes and toward the south. The present structure of Argentina indicates that migration dominates over drift. Am J Phys Anthropol 128:199‐209, 2005. © 2005 Wiley‐Liss, Inc.
Heat‐damage assessment of carbon‐fiber‐reinforced polymer composites by diffuse reflectance infrared spectroscopy
Authors: Dara I. H. , Ankara A. , Akovali G. , Suzer S.
Published: March 2005

Diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy was used to assess the effects of heat damage on carbon‐fiber‐reinforced polymer composites. Moisture‐saturated graphite–epoxy laminates with a quasi‐isotropic lay‐up were heat‐damaged above their upper service temperatures. The loss of matrix‐dominated mechanical properties due to heat exposure was investigated in the laboratory under environmental testing conditions with mechanical tests, ultrasonic C‐scanning, and DRIFT spectroscopy. The reduction of the mechanical strength of the composite materials was accompanied by an increase in the carbonyl band integral and a decrease in the phenyl ratio and hydroxyl and hydrocarbon band integrals, as shown by the DRIFT spectra. DRIFT was confirmed to be more effective than ultrasonic inspection in evaluating the extent of heat damage, and a good correlation was found between the mechanical test results and DRIFT spectra. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1222–1230, 2005
Macroporous chitosan/carboxymethylcellulose blend membranes and their application for lysozyme adsorption
Authors: Chen Xin , Liu Jiahao , Feng Zhicheng , Shao Zhengzhong
Published: March 2005

The adsorption of lysozyme was investigated with novel macroporous chitosan (CS)/carboxymethylcellulose (CMC) blend membranes. The CS/CMG blend membranes were prepared by a simple solution‐blending method with glutaraldehyde as a crosslinking agent for CS and with silica particles as porogens. The CS/CMC blend membranes were insoluble in aqueous media when the CMC concentration in the membranes did not exceed 30 mol %. The protein adsorption on these membranes from aqueous solutions containing different amounts of lysozyme at different pHs was investigated in batch systems. The results showed that the lysozyme adsorption capacity had a maximum at pH 9.2, and this indicated that the CS/CMC blend membranes could act as cation‐exchange membranes. Moreover, the blend membranes showed the best adsorption properties for lysozyme when the CMC concentration was 20 mol %. In addition, the lysozyme adsorption capacity of the blend membranes increased with an increase in the initial lysozyme concentration and the adsorption temperature. The maximum adsorption capacity of the macroporous CS/CMC blend membranes was as high as 240 mg/g (170 mg/mL), and more than 95% of the adsorbed lysozyme was desorbed in a pH buffer at 11.8. The blend membranes also demonstrated good reusability after several adsorption–desorption cycles. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1267–1274, 2005
General and specific self‐efficacy in the context of a training intervention to enhance performance expectancy
Authors: Schwoerer Catherine E. , May Douglas R. , Hollensbe Elaine C. , Mencl Jennifer
Published: March 2005

A pretest‐posttest field study investigated self‐efficacy, both general and specific, in an intensive training experience to prepare new recruits for their work assignments. Specific issues addressed include (1) the effects of the training experience on general self‐efficacy (GSE), work‐specific selfefficacy (SSE), and performance expectancy; (2) the effects of pretraining attitudes and beliefs on posttraining GSE and work SSE; and relations between posttraining self‐efficacy beliefs and posttraining performance expectancy. Training increased GSE, SSE, and performance expectancy. Unlike GSE, work SSE was influenced by pretraining motivation, training self‐efficacy, and performance expectancy. The implications of the findings for HRD research and practice are discussed from the perspectives of understanding individual characteristics of trainees, choosing methods to enhance self‐efficacy, and the appropriateness of measuring general and specific self‐efficacy before training (to guide planning) and after training (as an evaluation dimension)