bluuebunny/crossref_metadata_2025 huggingface dataset:
An Approximate Analytical Solution for Electro-Osmotic Flow of Power-Law Fluids in a Planar Microchannel
Authors: Sadeghi Arman , Fattahi Moslem , Hassan Saidi Mohammad
Published: July 2011

The present investigation considers the fully developed electro-osmotic flow of power-law fluids in a planar microchannel subject to constant wall heat fluxes. Using an approximate velocity distribution, closed form expressions are obtained for the transverse distribution of temperature and Nusselt number. The approximate solution is found to be quite accurate, especially for the values of higher than ten for the dimensionless Debye-Huckel parameter where the exact values of Nusselt number are predicted. The results demonstrate that a higher value of the dimensionless Debye-Huckel parameter is accompanied by a higher Nusselt number for wall cooling, whereas the opposite is true for wall heating case. Although to increase the dimensionless Joule heating term is to decrease Nusselt number for both pseudoplastic and dilatant fluids, nevertheless its effect on Nusselt number is more pronounced for dilatants. Furthermore, to increase the flow behavior index is to decrease the Nusselt number for wall cooling, whereas the contrary is right for the wall heating case. Depending on the value of flow parameters, a singularity is observed in the Nusselt number values of the wall heating case.
A New Approach for Rolling Contact Fatigue Numerical Study. Application to a Brittle Epoxy Resin
Authors: Francisco Arthur , Abbouchi Houssein , Villechaise Bernard
Published: July 2011

The background of the present study is the rolling contact fatigue (RCF) in a brittle polymer disk. The disk has been tested on a two disk machine, under controlled normal and tangential loads, with no global slip. After several million cycles and under different operating conditions, it has been observed that (1) the tangential load highly influences the RCF phenomenon, (2) a network of regularly spaced cracks appears, and (3) in the driving position, the RCF phenomenon develops faster. To explain these observations, a numerical model based on the finite element method (FEM) has been built: the cracks have been quite simply modeled, stick-slip has been chosen as the friction model, and the disk-on-disk contact has been replaced by a disk-on-plane contact. To study the influence of some of the operating conditions, the design of experiments (DOE) techniques has been used. The statistical postprocessing associated to DOE has confirmed the experimental observations with a good reliability. In addition, with some mechanical considerations, scenarios of what experimentally happens are proposed. The association FEM/DOE is an original and efficient way to explain phenomena in the field of RCF: the accuracy of the FEM coupled with DOE statistical treatments make it possible to have a good predictability despite some uncontrolled parameters.
Design and Fabrication of a Mechanically Matched Vascular Graft
Authors: Rachev Alexander , Felden Luc , Ku David N.
Published: July 2011

The study provides a pathway to design a mechanics-matching vascular graft for an end-to-end anastomosis to a host artery. For functional equivalence, we submit that the graft and a host artery should have equal inner deformed diameters, equal pressure-radius module, and experience equal axial forces when subjected to mean arterial pressure. These criteria for mechanical equivalence are valid for a large class of materials that can be considered as elastic incompressible and orthotropic solids. As an example, specific known artery properties were used to design or select a graft made from a new synthetic biomaterial to demonstrate that reliable and robust technology for graft fabrication is possible.
Effect of oxygen plasma-induced current blocking on the performance of GaN-based vertical light-emitting diodes
Authors: Lee Sang Youl , Choi Kwang Ki , Jeong Hwan Hee , Kim Eun Joo , Song June O. , Jeon Joon-Woo , Seong Tae-Yeon
Published: July 2011

We investigated the effect of O2 plasma-induced current blocking regions (O2-CBRs) on the performance of GaN-based vertical light-emitting diodes (VLEDs) as a function of the O2 plasma rf power. The VLEDs fabricated with the O2-CBRs give forward voltages in the range 3.41–3.48 V at 350 mA, which are slightly higher than those in the case of VLEDs with and without SiO2 current-blocking layers (CBLs). The output powers of VLEDs with O2-CBRs for rf powers of 50 and 100 W are 400.2 and 399.4 mW, respectively, which are slightly higher than those of the VLEDs with SiO2 CBLs. Indium tin oxide (ITO)-based contacts to p-GaN show rectifying behaviors with Schottky barrier heights of 1.89 and 2.78 eV, when treated at rf powers of 50 and 100 W, respectively. X-ray photoemission spectroscopy (XPS) results show that for the samples treated at 50 W, the Ga 2p core level moves toward the higher binding-energy side as compared to that of the reference sample without plasma treatment. On the basis of the electrical characteristics and XPS results, we state that the O2-CBR effect is due to the generation of donor-like defects at the p-GaN surface.
A Pericyte Origin of Spinal Cord Scar Tissue
Authors: Göritz Christian , Dias David O. , Tomilin Nikolay , Barbacid Mariano , Shupliakov Oleg , Frisén Jonas
Published: July 2011

Scars formed in response to damage to the central nervous system show unexpected complexity.
Distributed Cognition in the Lab
Science as Psychology
Sense-Making and Identity in Science Practice

by Lisa M. Osbeck, Nancy J. Nersessian, Kareen R. Malone, and Wendy C. Newstetter

Cambridge University Press, Cambridge, 2011. 287 pp. $90, £55. ISBN 9780521882071
Authors: Giere Ronald N.
Published: July 2011

The authors use their study of two biomedical engineering laboratories to explore how social, personal, and cognitive processes are combined in scientific thinking.
A Critical Point for Turbulence
Authors: Eckhardt Bruno
Published: July 2011

The conditions that mark the transition from laminar to turbulent flow in a pipe have been determined by experiments and numerical simulations.
Lipases in Cachexia
Authors: Arner Peter
Published: July 2011

Enzymes expressed in adipose tissue are involved in the loss of fat mass that occurs in a cancer-associated wasting disorder.
Foreign Researchers Begin to Make Their Mark
Authors: Qiu Jane
Published: July 2011

Foreign researchers are hailing a pair of fellowship programs launched in 2009 to bring non-Chinese scientists to labs at the Chinese Academy of Sciences.
Light at the End of the Radwaste Disposal Tunnel Could Be Real
Authors: Kerr Richard A.
Published: July 2011

A long run of failures could finally drive the United States to follow other countries' lead and accept radioactive waste disposal as the sociotechnological problem that it is.
Milky Way Researchers' Home Away From Home
Authors: Bhattacharjee Yudhijit
Published: July 2011

Right next door and easy to study, Andromeda provides an excellent model of how our own galaxy probably evolved.
Reduced Degranulation of NK Cells in Patients with Frequently Recurring Herpes
Authors: Murugin Vladimir V. , Zuikova Irina N. , Murugina Nina E. , Shulzhenko Andrey E. , Pinegin Boris V. , Pashenkov Mikhail V.
Published: July 2011

NK cells lyse virus-infected cells by degranulation; however, alterations in NK cell degranulation in persistent viral infections have not been directly studied. Earlier reports have documented a decrease in NK activity in patients with frequently recurring herpes (FRH). We corroborate these findings by showing that the degranulation responses of blood NK cells from patients with FRH, both during relapse and during remission, are significantly lower than those in healthy donors. The impaired degranulation was probably not caused by defective target cell recognition, since it was observed upon stimulation both with K562 cells and with a receptor-independent stimulus (phorbol 12-myristate 13-acetate plus ionomycin). We also show that the intracellular expression of perforin and CD107a by NK cells from patients with FRH is not different from that in healthy donors, thus excluding that the low NK cell degranulation in FRH is caused by a smaller size of the lytic granule compartment. We confirm previous reports on lowered NK activity in FRH patients and show that NK activity is significantly impaired only during remission, but not relapse; the causes for the discrepancy between the low degranulation and “normal” NK cell activity during relapse are discussed. In all, these data point at the deficit of NK cell degranulation in FRH. Whether this is a predisposing factor or a consequence of herpes simplex virus infection requires further investigation.
Antibodies to Lytic Infection Proteins in Lymphocryptovirus-Infected Rhesus Macaques: a Model for Humoral Immune Responses to Epstein-Barr Virus Infection
Authors: Orlova Nina , Fogg Mark H. , Carville Angela , Wang Fred
Published: July 2011

Humoral immune responses to rhesus lymphocryptovirus (rhLCV) lytic infection proteins were evaluated in the rhesus macaque animal model for Epstein-Barr virus (EBV) infection. We found a hierarchy of humoral responses to 14 rhLCV lytic infection proteins in naturally infected rhesus macaques, with (i) widespread and robust responses to four glycoproteins expressed as late proteins, (ii) frequent but less robust responses to a subset of early proteins, and (iii) low-level responses to immediate-early proteins. This hierarchy of humoral responses was similar to that reported for EBV-infected humans, with the notable exception of the response to rhBARF1. Serum antibodies to rhBARF1 were frequently detected in healthy rhLCV-infected macaques, but in humans, anti-BARF1 antibodies have been reported primarily in patients with EBV-positive nasopharyngeal carcinoma (NPC). The macaque data accurately predicted that serum antibodies against BARF1 are a normal response to EBV infection when human serum samples are analyzed. The rhesus macaque animal provides a unique perspective on humoral responses to EBV infection in humans and can be a valuable model for EBV vaccine development.
Acute Hepatitis as a Manifestation of Parvovirus B19 Infection
Authors: Hatakka Aleisha , Klein Julianne , He Runtao , Piper Jessica , Tam Edward , Walkty Andrew
Published: July 2011

There are few reports in the literature of hepatitis as a manifestation of parvovirus B19 infection. We describe a case of parvovirus B19-associated acute hepatitis diagnosed based on a positive serologic test (IgM) and molecular detection of parvovirus B19 DNA in a liver biopsy specimen. Parvovirus B19 infection should be considered in the differential diagnosis of patients presenting with acute hepatitis.
Helicobacter pylori
homB
, but Not
cagA
, Is Associated with Gastric Cancer in Iran
Authors: Talebi Bezmin Abadi Amin , Rafiei Alireza , Ajami Abolghasem , Hosseini Vahid , Taghvaei Tarang , Jones Kathleen R. , Merrell D. Scott
Published: July 2011

While several distinct virulence factors of
Helicobacter pylori
have been shown to be associated with different clinical outcomes, there is still much to learn about the role of different bacterial factors in gastric carcinogenesis. This study looked at the distribution of the
cagA
,
homA
, and
homB
genes in strains isolated from patients suffering from gastroduodenal diseases in Iran and assessed if there was any association between disease state and the presence of the aforementioned virulence factors. Genomic DNA from 138
H. pylori
strains was isolated and genotyped via PCR. Strains were obtained from dyspeptic patients (35 from gastritis patients, 62 from peptic ulcer patients, and 41 from gastric cancer patients) at the Teaching Touba Clinic and Imam Hospital of the Mazandaran University of Medical Sciences in Sari, Iran. The overall prevalence rates of
cagA
,
homA
, and
homB
were 58%, 54%, and 43%, respectively. Stratification of patients showed a significant difference in the prevalence of
H. pylori
virulence genes across the disease states. The frequency of
homB
was statistically significantly higher in gastric cancer patients (78%) than in patients suffering from peptic ulcers (20%) or gastritis (43%) (
P
< 0.0001). The presence of
homB
was also associated with the presence of
cagA
(
r
= 0.243). These data suggest that in this population the presence of
homB
may be a predictor of more virulent strains of
H. pylori
and influence the severity of disease manifestation.
Vesicular Stomatitis Virus Has Extensive Oncolytic Activity against Human Sarcomas: Rare Resistance Is Overcome by Blocking Interferon Pathways
Authors: Paglino Justin C. , van den Pol Anthony N.
Published: July 2011

Oncolytic viruses have been tested against many carcinomas of ectodermal and endodermal origin; however, sarcomas, arising from mesoderm, have received relatively little attention. Using 13 human sarcomas representing seven tumor types, we assessed the efficiency of infection, cytolysis, and replication of green fluorescent protein (GFP)-expressing vesicular stomatitis virus (VSV) and its oncolytically enhanced mutant VSV-rp30a. Both viruses efficiently infected and killed 12 of 13 sarcomas. VSV-rp30a showed a faster rate of infection and replication.
In vitro
and
in vivo
, VSV was selective for sarcomas compared with normal mesoderm. A single intravenous injection of VSV-rp30a selectively infected all subcutaneous human sarcomas tested in mice and arrested the growth of tumors that otherwise grew 11-fold. In contrast to other sarcomas, synovial sarcoma SW982 demonstrated remarkable resistance, even to high titers of virus (multiplicity of infection [MOI] of 100). We found no dysfunction in VSV binding or internalization. SW982 also resisted infection by human cytomegalovirus and Sindbis virus, suggesting a virus resistance mechanism based on an altered antiviral state. Quantitative reverse transcriptase (qRT)-PCR analysis revealed a heightened basal expression of interferon-stimulated genes (ISGs). Pretreatment, but not cotreatment, with interferon attenuators valproate, Jak1 inhibitor, or vaccinia virus B18R protein rendered SW982 highly susceptible, and this correlated with downregulation of ISG expression. Jak1 inhibitor pretreatment also enhanced susceptibility in moderately VSV-resistant liposarcoma and bladder carcinoma. Overall, we find that the potential efficacy of VSV as an oncolytic agent extends to nonhematologic mesodermal tumors and that unusually strong resistance to VSV oncolysis can be overcome with interferon attenuators.
RNA Binding by a Novel Helical Fold of B2 Protein from Wuhan Nodavirus Mediates the Suppression of RNA Interference and Promotes B2 Dimerization
Authors: Qi Nan , Cai Dawei , Qiu Yang , Xie Jiazheng , Wang Zhaowei , Si Jie , Zhang Jiamin , Zhou Xi , Hu Yuanyang
Published: July 2011

Wuhan nodavirus (WhNV) is a newly identified member of the
Nodaviridae
family with a bipartite genome of positive-sense RNAs. A nonstructural protein encoded by subgenomic RNA3 of nodaviruses, B2, serves as a potent RNA silencing suppressor (RSS) by sequestering RNA duplexes. We have previously demonstrated that WhNV B2 blocks RNA silencing in cultured
Drosophila
cells. However, the molecular mechanism by which WhNV B2 functions remains unknown. Here, we successfully established an RNA silencing system in cells derived from
Pieris rapae
, a natural host of WhNV, by introducing into these cells double-stranded RNA (dsRNA)-expressing plasmids or chemically synthesized small interfering RNAs (siRNAs). Using this system, we revealed that the WhNV B2 protein inhibited Dicer-mediated dsRNA cleavage and the incorporation of siRNA into the RNA-induced silencing complex (RISC) by sequestering dsRNA and siRNA. Based on the modeled B2 3-dimensional structure, serial single alanine replacement mutations and N-terminal deletion analyses showed that the RNA-binding domain of B2 is formed by its helices α2 and α3, while helix α1 mediates B2 dimerization. Furthermore, positive feedback between RNA binding and B2 dimerization was uncovered by gel shift assay and far-Western blotting, revealing that B2 dimerization is required for its binding to RNA, whereas RNA binding to B2 in turn promotes its dimerization. All together, our findings uncovered a novel RNA-binding mode of WhNV B2 and provided evidence that the promotion effect of RNA binding on dimerization exists in a viral RSS protein.
Epitopes Immediately below the Base of the V3 Loop of gp120 as Targets for the Initial Autologous Neutralizing Antibody Response in Two HIV-1 Subtype B-Infected Individuals
Authors: Tang Haili , Robinson James E. , Gnanakaran S. , Li Ming , Rosenberg Eric S. , Perez Lautaro G. , Haynes Barton F. , Liao Hua-Xin , LaBranche Celia C. , Korber Bette T. , Montefiori David C.
Published: July 2011

Epitopes that drive the initial autologous neutralizing antibody response in HIV-1-infected individuals could provide insights for vaccine design. Although highly strain specific, these epitopes are immunogenic, vulnerable to antibody attack on infectious virus, and could be involved in the ontogeny of broadly neutralizing antibody responses. To delineate such epitopes, we used site-directed mutagenesis, autologous plasma samples, and autologous monoclonal antibodies to map the amino acid changes that led to escape from the initial autologous neutralizing antibody response in two HIV-1 subtype B-infected individuals. Additional mapping of the epitopes was accomplished by using alanine scanning mutagenesis. Escape in the two individuals occurred by different pathways, but the responses in both cases appeared to be directed against the same region of gp120. In total, three amino acid positions were identified that were independently associated with autologous neutralization. Positions 295 and 332 are located immediately before and after the N- and C-terminal cysteines of the V3 loop, respectively, the latter of which affected an N-linked glycan that was critical to the neutralization epitope. Position 415 affected an N-linked glycan at position 413 in the C terminus of V4 that might mask epitopes near the base of V3. All three sites lie in close proximity on a four-stranded antiparallel sheet on the outer domain of gp120. We conclude that a region just below the base of the V3 loop, near the coreceptor binding domain of gp120, can be a target for autologous neutralization.
Productive Dengue Virus Infection of Human Endothelial Cells Is Directed by Heparan Sulfate-Containing Proteoglycan Receptors
Authors: Dalrymple Nadine , Mackow Erich R.
Published: July 2011

Dengue virus causes leakage of the vascular endothelium, resulting in dengue hemorrhagic fever and dengue shock syndrome. The endothelial cell lining of the vasculature regulates capillary permeability and is altered by immune and chemokine responses which affect fluid barrier functions of the endothelium. Our findings indicate that human endothelial cells are highly susceptible to infection by dengue virus (type 4). We found that dengue virus productively infects ∼80% of primary human endothelial cells, resulting in the rapid release of ∼105virions 1 day postinfection. Analysis of potential inhibitors of dengue virus entry demonstrated that antibodies and ligands to integrins and cellular receptors were unable to inhibit dengue virus infection of endothelial cells. In contrast, pretreating cells with heparin or heparan sulfate resulted in a 60 to 80% reduction in dengue virus-infected cells, and pretreatment of endothelial cells with heparinase III or protease reduced dengue infectivity by >80%. Dengue virus bound specifically to resin immobilized heparin, and binding was competitively inhibited by excess heparin but not other ligands. Collectively, these findings suggest that dengue virus specifically attaches to heparan sulfate-containing proteoglycan receptors on endothelial cells. Following attachment to human endothelial cell receptors, dengue virus causes a highly productive infection that has the potential to increase viral dissemination and viremia. This provides the potential for dengue virus-infected endothelial cells to directly alter barrier functions of the endothelium, contribute to enhancement of immune cell activation, and serve as potential targets of immune responses which play a central role in dengue pathogenesis.
Enhanced Control of Pathogenic Simian Immunodeficiency Virus SIVmac239 Replication in Macaques Immunized with an Interleukin-12 Plasmid and a DNA Prime-Viral Vector Boost Vaccine Regimen
Authors: Winstone Nicola , Wilson Aaron J. , Morrow Gavin , Boggiano Cesar , Chiuchiolo Maria J. , Lopez Mary , Kemelman Marina , Ginsberg Arielle A. , Mullen Karl , Coleman John W. , Wu Chih-Da , Narpala Sandeep , Ouellette Ian , Dean Hansi J. , Lin Feng , Sardesai Niranjan Y. , Cassamasa Holly , McBride Dawn , Felber Barbara K. , Pavlakis George N. , Schultz Alan , Hudgens Michael G. , King C. Richter , Zamb Timothy J. , Parks Christopher L. , McDermott Adrian B.
Published: July 2011

DNA priming has previously been shown to elicit augmented immune responses when administered by electroporation (EP) or codelivered with a plasmid encoding interleukin-12 (pIL-12). We hypothesized that the efficacy of a DNA prime and recombinant adenovirus 5 boost vaccination regimen (DNA/rAd5) would be improved when incorporating these vaccination strategies into the DNA priming phase, as determined by pathogenic simian immunodeficiency virus SIVmac239 challenge outcome. The whole SIVmac239 proteome was delivered in 5 separate DNA plasmids (pDNA-SIV) by EP with or without pIL-12, followed by boosting 4 months later with corresponding rAd5-SIV vaccine vectors. Remarkably, after repeated low-dose SIVmac239 mucosal challenge, we demonstrate 2.6 and 4.4 log reductions of the median SIV peak and set point viral loads in rhesus macaques (RMs) that received pDNA-SIV by EP with pIL-12 compared to the median peak and set point viral loads in mock-immunized controls (
P
< 0.01). In 5 out of 6 infected RMs, strong suppression of viremia was observed, with intermittent “blips” in virus replication. In 2 RMs, we could not detect the presence of SIV RNA in tissue and lymph nodes, even after 13 viral challenges. RMs immunized without pIL-12 demonstrated a typical maximum of 1.5 log reduction in virus load. There was no significant difference in the overall magnitude of SIV-specific antibodies or CD8 T-cell responses between groups; however, pDNA delivery by EP with pIL-12 induced a greater magnitude of SIV-specific CD4 T cells that produced multiple cytokines. This vaccine strategy is relevant for existing vaccine candidates entering clinical evaluation, and this model may provide insights into control of retrovirus replication.
Direct and Specific Binding of the UL16 Tegument Protein of Herpes Simplex Virus to the Cytoplasmic Tail of Glycoprotein E
Authors: Yeh Pei-Chun , Han Jun , Chadha Pooja , Meckes David G. , Ward Michael D. , Semmes O. John , Wills John W.
Published: July 2011

The UL16 tegument protein of herpes simplex virus (HSV) is conserved throughout all of the herpesvirus families. Previous studies have shown that the binding of HSV to heparan sulfate molecules on the host cell triggers the release of UL16 from the capsid, but the mechanism by which the signal is sent from the virion surface into the tegument is unknown. Here, we report that a glutathione
S
-transferase chimera bearing the cytoplasmic tail of viral glycoprotein E (gE) is capable of binding to UL16 in lysates of eukaryotic cells or purified from bacteria. Moreover, mass spectrometry studies of native-UL16 complexes purified from infected cells also revealed the presence of gE. Proof that UL16-gE can interact within cells required the fortuitous discovery of a mutant possessing only the first 155 residues of UL16. Confocal microscopy of cotransfected cells revealed that this mutant colocalized with gE in the cytoplasm, whereas it was found throughout the cytoplasm and nucleus when expressed alone. In contrast, the full-length UL16 molecule was very poorly capable of finding gE. Moreover, membrane flotation assays showed that UL16(1-155) was able to float to the top of sucrose step gradients when coexpressed with gE, whereas full-length UL16 was not. Thus, the discovery of the UL16(1-155) mutant confirmed the specific
in vitro
interaction with gE and provides evidence that a binding domain at the N terminus of UL16 may be controlled by a regulatory domain within the C terminus. These findings suggest the possibility that the UL16-gE interaction may play roles in the tegument signaling mechanism, virus budding, and the gE-mediated mechanism of cell-to-cell spread.
Correlation of the first reduction potential of selected radiosensitizers determined by cyclic voltammetry with theoretical calculations
Authors: Gál Miroslav , Kolivoška Viliam , Ambrová Marta , Híveš Ján , Sokolová Romana
Published: July 2011

Radiosensitizers are drugs that make cancer cells more sensitive to radiation therapy. The cytotoxic properties of such compounds are due to the fact that in the cell these compounds undergo one-electron reduction to generate radical anions. Therefore, their theoretical and/or experimental study is of high interest. To determine the correlation between reduction potential determined by cyclic voltammetry measurements and some physicochemical properties of selected radiosensitizers theoretical calculations of electron affinities based on the DFT method with B3LYP functional at the level of 6-311++G** basis set in vacuum were utilized. Very good correlation was found between electron affinities of radiosensitizers and their reduction potential and so called E71 potential that account for the energy necessary to transfer the first electron to an electroactive group at pH 7 in aqueous medium to form a radical anion.
Epstein–Barr virus infection and central nervous system involvement after orthoptic liver transplant: Table 1
Authors: Shafiq Kamran , Hassan Ahamad , Davies Mervyn H , Jones Rebecca L
Published: July 2011

Epstein–Barr virus (EBV) infection presenting as encephalitis in seronegative adults in the context of solid organ transplantation is rarely reported. EBV seroconversion illnesses in the adult population after organ transplantation are quite uncommon. This report describes a case of encephalitis due to EBV infection after liver transplantation in an adult patient. The patient was seronegative for EBV pretransplant. She showed persistent viral replication indicated by high levels of EBV DNA in the serum, which raised concerns for future development of post-transplant lymphoproliferative disorder. The report discusses the management of such patients, awareness of EBV infection and earlier diagnosis by use of EBV PCR in adult immunocompromised individuals where infection may cause particular problems.
APPLICABILITY OF A REPRESENTATION FOR THE MARTIN'S REAL-PART FORMULA IN MODEL-INDEPENDENT ANALYSES
Authors: FAGUNDES D. A. , MENON M. J.
Published: July 2011

Using a novel representation for the Martin's real-part formula without the full scaling property, an almost model-independent description of the proton–proton differential cross-section data at high energies (19.4 GeV–62.5 GeV) is obtained. In the impact parameter and eikonal frameworks, the extracted inelastic overlap function presents a peripheral effect (tail) above 2 fm and the extracted opacity function is characterized by a zero (change of sign) in the momentum transfer space, confirming results from previous model-independent analyses. Analytical parametrization for these empirical results are introduced and discussed. The importance of investigations on the inverse problems in high-energy elastic hadron scattering is stressed and the relevance of the proposed representation is commented. A short critical review on the use of Martin's formula is also presented.
CONSTRAINTS ON B→π, K TRANSITION FORM-FACTORS FROM EXCLUSIVE SEMILEPTONIC D-MESON DECAYS
Authors: SU FANG , YANG YA-DONG
Published: July 2011

According to the heavy-quark flavor symmetry, the B→π, K transition form-factors could be related to the corresponding ones of D-meson decays near the zero recoil point. With the recent precisely measured exclusive semileptonic decays D →πℓν and D→K ℓν, we perform a phenomenological study of B →π, K transition form-factors based on this symmetry. Using BK, BZ and Series Expansion parametrizations of the form-factor slope, we extrapolate B →π, K transition form-factors from [Formula: see text] to q2 = 0. It is found that, although being consistent with each other within error bars, the central values of our results for B →π, K form-factors at q2 = 0, [Formula: see text], are smaller than predictions of the QCD light-cone sum rules, but are in good agreements with the ones extracted from hadronic B-meson decays within the SCET framework. Moreover, smaller form-factors are also favored by the QCD factorization approach for hadronic B-meson decays.
EFFECT OF CLIENT DEMANDS ON DESTRUCTIVENESS OF TARGETED ATTACKS IN DIRECTED WEIGHTED SCALE-FREE NETWORKS
Authors: MA LI-LI , JIANG XIN , ZHANG ZHAN-LI , ZHENG ZHI-MING
Published: July 2011

Network resilience is vital for the survival of networks, and scale-free networks are fragile when confronted with targeted attacks. We survey network robustness to targeted attacks from the viewpoint of network clients by designing a unique mechanism based on the undeniable roles of network clients in real-world networks. Especially, the mechanism here is designed on the actual phenomenon that the vital nodes in a network may be totally different for clients with different demands. Concretely, node client-demand centrality is proposed to quantify the contributions of nodes to network clients and we show that it is a proper index to assign an order to network nodes according to node importance for network clients. Great discrepancy of node importance order for clients with different demands is found in scale-free networks with four different kinds of link weight distribution, which suggests that the destructiveness of fatal attacks on networks can be greatly reduced by adjusting the demands of network clients.
HIGH ROCK SLOPE STABILITY ANALYSIS USING THE ENRICHED MESHLESS SHEPARD AND LEAST SQUARES METHOD
Authors: ZHU HEHUA , ZHUANG XIAOYING , CAI YONGCHANG , MA GUOWEI
Published: July 2011

The meshless methods are particularly suitable for modeling problems with discontinuities such as joints in rock mass. The meshless Shepard and least squares (MSLS) method is a newly developed meshless method, which overcomes some limitations with other meshless methods. In the present paper, the MSLS method is extended for modeling jointed rock mass and the joint is modeled as discontinuity governing the near-field stress. A substantial high rock slope by the dam shoulder of Jinping Hydropower Station is analyzed by the developed method. Safety factors are evaluated based on the stress results along potential slip surfaces and compared with the conventional slice methods. The results demonstrate the feasibility of using the MSLS method in rock slope stability analysis and also reveal some interesting differences from the conventional slice methods. Some findings and outstanding issues demonstrated in this study are discussed in the end, which can be the topics for future development.
ARBITRARY DISCONTINUITIES IN THE NUMERICAL MANIFOLD METHOD
Authors: AN XINMEI , MA GUOWEI , CAI YONGCHANG , ZHU HEHUA
Published: July 2011

An overview of modeling arbitrary discontinuities within the numerical manifold method (NMM) framework is presented. The NMM employs a dual cover system, namely mathematical covers (MCs) and physical covers (PCs), to describe a physical problem. MCs are constructed totally independent of geometries of the problem domain, over which a partition of unity is defined. PCs are the intersections of MCs and the problem domain, over which local approximations with unknowns to be determined are defined. With such a dual cover system, arbitrary discontinuities involving jumps, kinks, singularities, and other nonsmooth features can be modeled in a convenient manner by constructing special PCs and designing tailored local approximations. Several typical discontinuities in solid mechanics are discussed. Among them are the simulations of material boundaries, voids, brittle cracks, cohesive cracks, material interfaces, interface cracks, dislocations, shear bands, high gradient zones, etc.
A simple method for measuring intracellular activities of glutamine synthetase and glutaminase in glial cells
Authors: Mongin Alexander A. , Hyzinski-García María C. , Vincent Melanie Y. , Keller Richard W.
Published: July 2011

Here we report and validate a simple method for measuring intracellular activities of glial glutamine synthetase (GS) and glutaminase (GLNase) in intact glial cells. These enzymes are responsible for glutamate and glutamine recycling in the brain, where glutamate and glutamine transport from the blood stream is strongly limited by the blood-brain barrier. The intracellular levels of glutamate and glutamine are dependent on activities of numerous enzymatic processes, including 1) cytosolic production of glutamine from glutamate by GS, 2) production of glutamate from glutamine by GLNase that is primarily localized between mitochondrial membranes, and 3) mitochondrial conversion of glutamate to the tricarboxylic cycle intermediate α-ketoglutarate in the reactions of oxidative deamination and transamination. We measured intracellular activities of GS and GLNase by quantifying enzymatic interconversions of l-[3H]glutamate and l-[3H]glutamine in cultured rat astrocytes. The intracellular substrate and the products of enzymatic reactions were separated in one step using commercially available anion exchange columns and quantified using a scintillation counter. The involvement of GS and GLNase in the conversion of 3H-labeled substrates was verified using irreversible pharmacological inhibitors for each of the enzymes and additionally validated by measuring intracellular amino acid levels using an HPLC. Overall, this paper describes optimized conditions and pharmacological controls for measuring GS and GLNase activities in intact glial cells.
Residues 248–252 and 300–304 of the cardiac Na+/Ca2+ exchanger are involved in its regulation by phospholemman
Authors: Zhang Xue-Qian , Wang JuFang , Song Jianliang , Ji Angi M. , Chan Tung O. , Cheung Joseph Y.
Published: July 2011

Using split cardiac Na+/Ca2+ exchangers (NCX1), we previously demonstrated that phospholemman (PLM) regulates NCX1 by interacting with the proximal linker domain (residues 218–358) of the intracellular loop of NCX1. With the use of overlapping loop deletion mutants, interaction sites are localized to two regions spanning residues 238–270 and residues 300–328 of NCX1. In this study, we used alanine (Ala) linker scanning to pinpoint the residues in the proximal linker domain involved in regulation of NCX1 by PLM. Transfection of human embryonic kidney (HEK)293 cells with wild-type (WT) NCX1 or its Ala mutants but not empty vector resulted in NCX1 current ( INaCa). Coexpression of PLM with WT NCX1 inhibited INaCa. Mutating residues 248–252 (PASKT) or 300–304 (QKHPD) in WT NCX1 to Ala resulted in loss of inhibition of INaCa by PLM. By contrast, inhibition of INaCa by PLM was preserved when residues 238–242, 243–247, 253–257, 258–262, 263–267, 305–309, 310–314, 315–319, 320–324, or 325–329 were mutated to Ala. While mutating residue 301 to alanine completely abolished PLM inhibition, mutation of any single residue 250–252, 300, or 302–304 resulted in partial reduction in inhibition. Mutating residues 248–252 to Ala resulted in significantly weaker association with PLM. The NCX1-G503P mutant that lacks Ca2+-dependent activation retained its sensitivity to PLM. We conclude that residues 248–252 and 300–304 in the proximal linker domain of NCX1 were involved in its inhibition by PLM.
Implication of microRNAs in atrial natriuretic peptide and nitric oxide signaling in vascular smooth muscle cells
Authors: Kotlo Kumar U. , Hesabi Bahar , Danziger Robert S.
Published: July 2011

MicroRNAs (miRs) are endogenous small RNA molecules that suppress gene expression by binding to complementary sequences in the 3′ untranslated regions of their target genes. miRs have been implicated in many diseases, including heart failure, ischemic heart disease, hypertension, cardiac hypertrophy, and cancers. Nitric oxide (NO) and atrial natriuretic peptide (ANP) are potent vasorelaxants whose actions are mediated through receptor guanylyl cyclases and cGMP-dependent protein kinase. The present study examines miRs in signaling by ANP and NO in vascular smooth muscle cells. miR microarray analysis was performed on human vascular smooth muscle cells (HVSMC) treated with ANP (10 nM, 4 h) and S-nitroso- N-acetylpenicillamine (SNAP) (100 μM, 4 h), a NO donor. Twenty-two shared miRs were upregulated, and 21 shared miRs were downregulated, by both ANP and SNAP ( P < 0.05). Expression levels of four miRs (miRs-21, -26b, -98, and -1826), which had the greatest change in expression, as determined by microarray analysis, were confirmed by quantitative RT-PCR. Rp-8-Br-PET-cGMPS, a cGMP-dependent protein kinase-specific inhibitor, blocked the regulation of these miRs by ANP and SNAP. 8-bromo-cGMP mimicked the effect of ANP and SNAP on their expression. miR-21 was shown to inhibit HVSMC contraction in collagen gel lattice contraction assays. We also identified by computational algorithms and confirmed by Western blot analysis new intracellular targets of miR-21, i.e., cofilin-2 and myosin phosphatase and Rho interacting protein. Transfection with pre-miR-21 contracted cells and ANP and SNAP blocked miR-21-induced HVSMC contraction. Transfection with anti-miR-21 inhibitor reduced contractility of HVSMC ( P < 0.05). The present results implicate miRs in NO and ANP signaling in general and miR-21 in particular in cGMP signaling and vascular smooth muscle cell relaxation.
Anatomical dissociation of melanocortin receptor agonist effects on taste- and gut-sensitive feeding processes
Authors: Baird John-Paul , Palacios Mariana , LaRiviere Michael , Grigg Lindsay A. , Lim Christopher , Matute Eduardo , Lord Julia
Published: July 2011

Injections of the melanocortin 3/4 receptor (MCR) agonist melanotan II (MTII) to a variety of brain structures produces anorexia, suggesting distributed brain MCR control of food intake. We performed a detailed analysis of feeding behavior (licking microstructure analysis) after a range of MTII doses (0.005 nM to 1 nM) was targeted to the forebrain (third ventricle, 3V) or hindbrain (fourth ventricle, 4V) regions. MTII (0.1 nM and 1 nM) delivered to the 3V or 4V significantly reduced 0.8 M sucrose intake. The anorexia was mediated by reductions in the number of licking bursts in the meal, intrameal ingestion rate, and meal duration; these measures have been associated with postingestive feedback inhibition of feeding. Anorexia after 3V but not 4V MTII injection was also associated with a reduced rate of licking in the first minute (initial lick rate) and reduced mean duration of licking bursts; these measures have been associated with taste evaluation. MTII effects on taste evaluation were further explored: In experiment 2, 3V MTII (1 nM) significantly reduced intake of noncaloric 4 mM saccharin and 0.1 M and 1 M sucrose solutions, but not water. The anorexia was again associated with reduced number of licking bursts, ingestion rate, meal duration, initial lick rate, and mean burst duration. In experiments 3 and 4, brief access (20 s) licking responses for sweet sucrose (0.015 M to 0.25 M) and bitter quinine hydrochloride (0.01 mM to 1 mM) solutions were evaluated. Licking responses for sucrose were suppressed, whereas those for quinine solutions were increased after 3V MTII, but not after 4V MTII injections (0.1 nM and 1 nM). The results suggest that multiple brain MCR sites influence sensitivity to visceral feedback, whereas forebrain MCR stimulation is necessary to influence taste responsiveness, possibly through attenuation of the perceived intensity of taste stimuli.
Advanced glycation end products inhibit adhesion ability of differentiated podocytes in a neuropilin-1-dependent manner
Authors: Bondeva Tzvetanka , Wojciech Stefanie , Wolf Gunter
Published: July 2011

Podocyte injury can occur by a number of stimuli. Maintaining of an intact podocyte structure is essential for glomerular filtration; therefore, podocyte damage severely impairs renal function. Recently, we have reported that addition of glycated BSA [advanced glycation end products (AGE)-BSA] to differentiated murine podocytes inhibited neuropilin-1 (NRP1) expression and dramatically influenced podocyte migration ability (Bondeva T, Ruster C, Franke S, Hammerschmid E, Klagsbrun M, Cohen CD, Wolf G. Kidney Int 75: 605–616, 2009; Bondeva T, Wolf G. Am J Nephrol 30: 336–345, 2009). The present study analyzes the influence of AGEs and NRP1 on podocyte adhesion and cytoskeleton reorganization. We show that treatment with AGE-BSA significantly reduced podocyte adhesion to collagen IV, laminin, and fibronectin compared with Co-BSA (nonglycated BSA)-incubated cells, which was further augmented by transient inhibition of NRP1 expression using NRP1 short interference (si) RNA. On the other hand, forced overexpression of NRP1 markedly increased the adhesion ability of podocytes to the ECMs despite the AGE-BSA treatment. No changes were observed when podocyte adhesion to collagen I was assayed. These findings were also manifested with disorganization of podocyte actin stress fibers and decreased lamellipodia formation processes due to AGE-BSA treatment or NRP1 suppression. In addition, AGE-BSA or suppression of NRP1 both reduced the phosphorylation of focal adhesion kinase (FAK) and Erk1/2 in PMA-stimulated differentiated podocytes. Analysis of RhoA family GTPase activity demonstrated that treatment with AGE-BSA or NRP1 depletion inhibited as well the activation of the Rac-1 and Cdc42 but did not affect RhoA activity. All these effects were reversed by forced overexpression of full-length NRP1 cloned into the pcDNA3 vector in differentiated podocytes. Our study demonstrates that AGEs, in part via suppression of NRP1 expression, decreased podocyte adhesion and contribute to reduction of Rac-1 and Cdc42 GTPase activity. These effects may be further responsible for the podocytes damage and loss in diabetic nephropathy. Our findings suggest a role for NRP1 in regulating the podocyte actin cytoskeleton, and therefore reduction of NRP1 expression could be critical for podocyte function.
Somatic calcium level reports integrated spiking activity of cerebellar interneurons in vitro and in vivo
Authors: Franconville Romain , Revet Gaëlle , Astorga Guadalupe , Schwaller Beat , Llano Isabel
Published: July 2011

We examined the relationship between somatic Ca2+ signals and spiking activity of cerebellar molecular layer interneurons (MLIs) in adult mice. Using two-photon microscopy in conjunction with cell-attached recordings in slices, we show that in tonically firing MLIs loaded with high-affinity Ca2+ probes, Ca2+-dependent fluorescence transients are absent. Spike-triggered averages of fluorescence traces for MLIs spiking at low rates revealed that the fluorescence change associated with an action potential is small (1% of the basal fluorescence). To uncover the relationship between intracellular Ca2+ concentration ([Ca2+]i) and firing rates, spikes were transiently silenced with puffs of the GABAA receptor agonist muscimol. [Ca2+]i relaxed toward basal levels following a single exponential whose amplitude correlated to the preceding spike frequency. The relaxation time constant was slow (2.5 s) and independent of the probe concentration. Data from parvalbumin (PV)−/− animals indicate that PV controls the amplitude and decay time of spike-triggered averages as well as the time course of [Ca2+]i relaxations following spike silencing. The [Ca2+]i signals were sensitive to the L-type Ca2+ channel blocker nimodipine and insensitive to ryanodine. In anesthetized mice, as in slices, fluorescence traces from most MLIs did not show spontaneous transients. They nonetheless responded to muscimol iontophoresis with relaxations similar to those obtained in vitro, suggesting a state of tonic firing with estimated spiking rates ranging from 2 to 30 Hz. Altogether, the [Ca2+]i signal appears to reflect the integral of the spiking activity in MLIs. We propose that the muscimol silencing strategy can be extended to other tonically spiking neurons with similar [Ca2+]i homeostasis.
Manifold reaching paradigm: how do we handle target redundancy?
Authors: Berret Bastien , Chiovetto Enrico , Nori Francesco , Pozzo Thierry
Published: July 2011

How the central nervous system coordinates the many intrinsic degrees of freedom of the musculoskeletal system is a recurrent question in motor control. Numerous studies addressed it by considering redundant reaching tasks such as point-to-point arm movements, for which many joint trajectories and muscle activations are usually compatible with a single goal. There exists, however, a different, extrinsic kind of redundancy that is target redundancy. Many times, indeed, the final point to reach is neither specified nor unique. In this study, we aim to understand how the central nervous system tackles such an extrinsic redundancy by considering a reaching-to-a-manifold paradigm, more specifically an arm pointing to a long vertical bar. In this case, the endpoint is not defined a priori and, therefore, subjects are free to choose any point on the bar to successfully achieve the task. We investigated the strategies used by subjects to handle this presented choice. Our results indicate both intersubject and intertrial consistency with respect to the freedom provided by the task. However, the subjects' behavior is found to be more variable than during classical point-to-point reaches. Interestingly, the average arm trajectories to the bar and the structure of intertrial endpoint variations could be explained via stochastic optimal control with an energy/smoothness expected cost and signal-dependent motor noise. We conclude that target redundancy is first overcome during movement planning and then exploited during movement execution, in agreement with stochastic optimal feedback control principles, which illustrates how the complementary problems of goal and movement selection may be resolved at once.
Transition in Deformation Mechanism of AZ31 Magnesium Alloy during High-Temperature Tensile Deformation
Authors: Noda Masafumi , Mori Hisashi , Funami Kunio
Published: July 2011

Magnesium alloys can be used for reducing the weight of various structural products, because of their high specific strength. They have attracted considerable attention as materials with a reduced environmental load, since they help to save both resources and energy. In order to use Mg alloys for manufacturing vehicles, it is important to investigate the deformation mechanism and transition point for optimizing the material and vehicle design. In this study, we investigated the transition of the deformation mechanism during the high-temperature uniaxial tensile deformation of the AZ31 Mg alloy. At a test temperature of 523 K and an initial strain rate of 3×10−3 s-1, the AZ31 Mg alloy (mean grain size: ~5 μm) exhibited stable deformation behavior and the deformation mechanism changed to one dominated by grain boundary sliding.
A New General Iterative Method for Solution of a New General System of Variational Inclusions for Nonexpansive Semigroups in Banach Spaces
Authors: Sunthrayuth Pongsakorn , Kumam Poom
Published: July 2011

We introduce a new general system of variational inclusions in Banach spaces and propose a
new iterative scheme for finding common element of the set of solutions of the variational inclusion with set‐valued maximal monotone mapping and Lipschitzian relaxed cocoercive mapping and the set of fixed point
of nonexpansive semigroups in a uniformly convex and 2‐uniformly smooth Banach space. Furthermore,
strong convergence theorems are established under some certain control conditions. As applications, finding
a common solution for a system of variational inequality problems and minimization problems is given.