bluuebunny/crossref_metadata_2025 huggingface dataset:
Apparent digestibilities of diets based on timothy and Italian ryegrass hay harvested in different regions in Japan fed to exercising Thoroughbreds
Authors: MATSUI Akira , INOUE Yoshinobu , ASAI Yo
Published: July 2005

The apparent digestibility of diets based on timothy hay harvested in Hidaka in Hokkaido (HT) and Italian ryegrass hay harvested in Miyazaki in Kyushu (MI) were compared in Thoroughbreds undergoing exercise. The nitrogen retention and plasma‐free amino acid (AA) concentrations were also examined to evaluate the quality of the protein contained in the two types of hay. Four male Thoroughbreds (aged 34.4 ± 0.9 months (mean ± standard deviation) and weighing 506.3 ± 30.4 kg) undergoing exercise training at 80% of maximal heart rate were used for the study, and the apparent digestibility of the diets based on HT and MI was assessed. The net nitrogen balance was also measured by subtracting the amount of nitrogen excreted in the feces and urine from the total nitrogen intake. The apparent digestibilities of dry matter, energy, neutral detergent fiber and ether extract were all higher in the MI group than in the HT group (P < 0.05). The larger energy digestibility in the MI group (56.8 ± 3.3%) compared with that in the HT group (51.6 ± 2.4%) was attributed to the relatively easy digestibility of hemicellulose. The net nitrogen balance and plasma AA concentrations did not differ significantly between the two forage groups. We concluded that the nutritive value of MI is adequate for exercising horses, even though the timothy and Italian ryegrass used in this study were second cuttings, and their nutrient values were not easily comparable.
Effects of fasting and refeeding on plasma concentrations of leptin, ghrelin, insulin, growth hormone and metabolites in swine
Authors: INOUE Hiroaki , WATANUKI Masashi , MYINT Hnin Thidar , ITO Tetsuya , KUWAYAMA Hideto , HIDARI Hisashi
Published: July 2005

The effects of nutritional status, such as fasting and refeeding, on leptin and ghrelin secretion in swine were examined. The swine (n = 4) were fasted for 54 h and plasma hormone levels were measured before, during and after fasting. Plasma leptin and insulin concentrations began to decrease 12 and 6 h into the fasting period, respectively (P < 0.05), and maintained a low level for the remaining period of fasting. Plasma leptin and insulin returned to the pre‐fasting value 6 and 12 h after refeeding, respectively. Plasma ghrelin concentrations showed a nocturnal periodicity during the fasting period; it increased nocturnally at 36 and 42 h into the fasting period (P < 0.05). Plasma growth hormone levels did not show any remarkable changes during the fasting. Plasma glucose levels showed a modest fall during fasting and significantly decreased (P < 0.05) at 24 h into the fasting period, returning to pre‐fasting levels after refeeding. Plasma nonesterified fatty acid levels increased (P < 0.05) at 12 h into the fasting period and returned to the pre‐fasting level 6 h after refeeding. These results indicate that plasma leptin, insulin and ghrelin play an important role in maintaining energy homeostasis in swine. The plasma ghrelin did not continuously increase, but showed nocturnal periodicity during fasting. This may suggest that ghrelin is also involved in physiological processes other than energy homeostasis.
Inhibition of growth hormone secretagogue receptor antagonist, [D‐Lys‐3]‐GHRP‐6, in adipogenesis of ovine and rat adipocytes
Authors: ROH Sang‐gun , HONG Yeon‐hee , HISHIKAWA Daisuke , TSUZUKI Hiroaki , MIYAHARA Hisae , NISHIMURA Yukihiko , GOTO Chizu , SUZUKI Yasuki , CHOI Ki‐choon , LEE Hong‐gu , SASAKI Shinichi
Published: July 2005

Ghrelin and growth hormone secretagogues receptor (GHS‐R or ghrelin receptor) have been reported as being one of the factors of adipogenesis in adipocytes. To investigate the involvement of ghrelin and GHS‐R in adipocytes, the effect of the GHS‐R antagonist, [D‐Lys‐3]‐GHRP‐6 (His‐D‐Trp‐D‐Lys‐Trp‐D‐Phe‐Lys‐NH2), on the process of adipogenesis in ovine and rat adipocytes was evaluated. [D‐Lys‐3]‐GHRP‐6 (10−7 mol/L) significantly inhibited adipogenic differentiation of ovine and rat preadipocytes prepared from adipose tissues. The level of peroxisome proliferator activated receptor (PPAR)‐γ2 mRNA, an adipogenic marker, was decreased during the differentiation of adipocytes treated with [D‐Lys‐3]‐GHRP‐6 for 10 days. Ghrelin stimulated adipogenesis, also causing an increment of glycerol‐3‐phosphate dehydrogenase and upregulation of PPAR‐γ2. Furthermore, the antilipolytic effect of ghrelin was attenuated by treatment with [D‐Lys‐3]‐GHRP‐6 in both types of isolated adipocytes. Overall, the results of the present study highlight that GHS‐R in adipogenesis can be blocked by treatment with [D‐Lys‐3]‐GHRP‐6.
Effect of the last diet on the selective feeding behavior of heifers
Authors: FUKASAWA Michiru , TSUKADA Hideharu , KOSAKO Takami , KOHARI Daisuke
Published: July 2005

The present study examined and discussed the way the basal diet (BD) during the preliminary phase and the last diet (LD) before the food selection test affected the selective feeding behavior of heifers. For the BD and LD, oat hay and concentrate were used. Three different levels of roughage content (low, medium and high) were prepared by changing the mix ratios of oat hay and concentrate. Low and high roughage diets were used for the BD, and all three of the roughage levels were used for the LD. A mixture of orchard grass and white clover (MIX), and Japanese pampas grass leaf (JP) were used as testing foods. In the preliminary phase, all heifers were fed the BD three times per day. In the test phase, heifers were fed the LD for the first meal (06.00–12.00 hours), and food selection under different BD and LD was examined during the second meal (13.00–16.00 hours) of the day. The effects of the BD were significant for MIX dry matter intake (DMI), JP DMI and the rate of MIX DMI for total DMI. Under the high roughage BD condition, heifers ingested more MIX than under the low roughage BD condition. The effect of the LD was significant on JP DMI, whereas the rate of MIX DMI for total DMI was not significant. Selective feeding behavior was strongly affected by the BD and slightly by the LD.
Dairy farming financial structures in Hokkaido, Japan and New Zealand
Authors: OZAWA Takeyuki , LOPEZ‐VILLALOBOS Nicolas , BLAIR Hugh T.
Published: July 2005

The productivity and financial performance of dairy farms in New Zealand and Japan (Hokkaido) were analyzed. By recomposing the official statistics on the dairy industry relative to Japan, New Zealand has low milk yield productivity per cow, but higher per hectare performance because of their seasonal breeding and pasture grazing systems. In the revenue and expenses analysis, New Zealand had a high cash surplus ratio compared with Hokkaido. In the cost analysis, for expenses on a “per kg of raw milk” basis, New Zealand milk production costs are 29% of those in Hokkaido. More than 60% of the production costs were attributable to feed, interest charges and wages in New Zealand. In Hokkaido, the feed cost alone accounted for 73% of the total cost. There is also a remarkably high interest expenditure in New Zealand caused by non‐subsidized fund procurement from finance organizations. In the financial analysis, New Zealand dairy farms have only approximately 50% of the total assets per cow compared with farms in Hokkaido. But total liabilities per cow in Hokkaido are twofold to threefold greater than in New Zealand. The difference between total assets and total liabilities shows that Hokkaido dairy farmers have an equity that is 50–200% greater than New Zealand dairy farmers. In the management analysis, New Zealand has a low turnover ratio of gross assets caused by the seasonal breeding system. In conclusion, New Zealand has higher per hectare production performance than Hokkaido, but has a low utilization of gross assets caused by a seasonal breeding system based on pasture grazing.
Analysis of Water Transport in Proton Exchange Membranes Using a Phenomenological Model
Authors: Sui P. C. , Djilali Ned
Published: July 2005

An investigation of water transport across the membrane of a proton exchange membrane fuel cell is performed to gain further insight into water management issues and the overall behavior of a representative phenomenological model. The model accounts for water transport via electro-osmotic drag and diffusion and is solved using a finite volume method for a one-dimensional isothermal system. Transport properties including the water drag and diffusion coefficients and membrane ionic conductivity are expressed as functions of water content and temperature. An analytical solution based on a generalized form of the transport properties is also derived and used to validate the numerical solutions. The effects of property variations on the water flux across the membrane and on the overall membrane protonic conductivity are analyzed. The balance between transport via electro-osmotic drag and diffusion depends not only on operating conditions, such as current density and relative humidity at the membrane boundaries, but also on design parameters, such as membrane thickness and membrane material. Computed water fluxes for different humidity boundary conditions indicate that for a thick membrane (e.g., Nafion 117), electro-osmotic drag dominates the transport over a wide range of operating conditions, whereas for a thin membrane (e.g., Nafion 112), diffusion of water becomes equally important under certain humidification conditions and current densities. Implications for the resolution of membrane transport in CFD-based models of proton exchange membrane fuel cells are also discussed.
Performance Measurements of Solid-Oxide Electrolysis Cells for Hydrogen Production
Authors: O’Brien J. E. , Stoots C. M. , Herring J. S. , Lessing P. A. , Hartvigsen J. J. , Elangovan S.
Published: July 2005

An experimental study has been completed to assess the performance of single solid-oxide electrolysis cells operating over a temperature range of 800 to 900°C. The experiments were performed over a range of steam inlet partial pressures (2.3–12.2 kPa), carrier gas flow rates (50–200 sccm), and current densities (−0.75–0.25A∕cm2) using single electrolyte-supported button cells of scandia-stabilized zirconia. Steam consumption rates associated with electrolysis were measured directly using inlet and outlet dew-point instrumentation. Cell operating potentials and cell current were varied using a programmable power supply and monitored continuously. Values of area-specific resistance and thermal efficiency are presented as a function of current density. Cell performance is shown to be continuous from the fuel-cell mode to the electrolysis mode of operation. The effects of steam starvation and thermal cycling on cell performance parameters are discussed.
Mass/Charge Transfer in Mono-Block-Layer-Built-Type Solid-Oxide Fuel Cells
Authors: Hwang J. J.
Published: July 2005

The mass/charge transfer characteristics in a simulated MOLB (mono-block-layer built)-type solid-oxide fuel cells have been studied numerically. The transport phenomena within a linear MOLB module, including flow channels, active porous electrodes, electrolyte, and interconnections, are simulated using the finite volume method. The gas flow in the porous electrodes is governed by the isotropic linear resistance model with constant porosity and permeability. The diffusions of reactant species in the porous electrodes are described by the Stefan-Maxwell relation. Effective diffusivities for porous layers follow the Bruggman model. Porous electrochemistry is depicted via surface reactions with a constant surface-to-volume ratio, tortuosity, and average pore size. Results of the cathode-supported cell and the anode-supported cell are obtained, discussed, and compared thereafter for the first time.
Fabrication Using High-Energy Ball-Milling Technique and Characterization of Pt-Co Electrocatalysts for Oxygen Reduction in Polymer Electrolyte Fuel Cells
Authors: Pharkya Pallavi , Alfantazi Akram , Farhat Zoheir
Published: July 2005

This work discusses the fabrication and characterization of Pt-Co electrocatalysts for polymer electrolyte membrane fuel cells (PEMFC) and electrocatalysis of the oxygen reduction reaction. Two sets of carbon supported catalysts with Pt:Co in the atomic ratio of 0.25:0.75 and 0.75:0.25 were prepared using a high-energy ball-milling technique. One of the Pt-Co electrocatalysts was subjected to lixiviation to examine the change in surface area. Microstructural characterization of the electrocatalysts was done using scanning electron microscopy, transmission electron microscopy, x-ray diffractometry, and x-ray photoelectron spectroscopy. Electrochemical characterization of the electrocatalysts was done in acidic and alkaline media using cyclic voltammetry and potentiodynamic polarization techniques. These tests were performed at room and higher temperature (50°C). Performances of the electrocatalysts were also compared with the commercial E-TEK Pt:Co alloy electrocatalysts of the compositions 10% Pt-Co alloy (1:1 a/o) and 40% Pt-Co alloy (1:1 a/o) on Vulcan XC-72.
Plasma-Polymerized Proton-Conducting Membranes for Reducing Methanol Permeation in DMFCs
Authors: Gruber D. , Ponath N. , Müller J.
Published: July 2005

A plasma polymerization process for preparing proton-conducting electrolyte membranes from tetrafluoroethylene and water is presented. They can be deposited on different substrates, e.g., gas diffusion layers or as barrier layers on other polymer electrolyte membranes. An advantage of the plasma-polymerized membranes is their lower methanol permeability due to their highly cross-linked structure. Methanol permeation measurements with 3M methanol solution exhibit methanol permeabilities which are by an order of a magnitude less than for Nafion® 115. The proton conductivity of the plasma-polymerized membranes varies from 10to160mS∕cm depending on deposition parameters.
Novel Testing Method for Fuel Cell Hardware Design and Assembly
Authors: Weng Fang-Bor , Su Ay , Lin Yur-Tsai , Jung Guo-Bin , Chen Yen-Ming
Published: July 2005

A simple, low-cost testing method is proposed for fuel cell hardware development. A perforated aluminum foil with an array of small holes covered with carbon paper or cloth replaces the membrane electrode assemblies to test the contact resistance and gas permeability of the carbon paper. Practical fuel cells of 50cm2 reaction area with different gasket thicknesses and compressed pressures are tested for performance. The results of ohmic resistance and permeability of compressed carbon paper indicate strong relevance to cell performance, demonstrating that this novel testing method is valuable for fuel cell hardware development. Also, the compression mechanism of the diffusion layer is discussed along with a proposal for a strategy for improving cell performance. After that, an advanced design of a 25cm2 single cell is developed. The results of cell performance of the advanced cell are acceptable and competitive with the performance data of commercial products.
Chemical Treatment Method for the Aluminum Bipolar Plates of PEM Fuel Cells
Authors: Lee Shuo-Jen , Huang Ching-Han , Chen Yu-Pang , Chen Yen-Ming
Published: July 2005

In this paper, a chemical treatment method was developed to process the aluminum bipolar plates of proton electrolyte membrane fuel cells. During the surface treatment process, the chemical in the aluminum reacts with the electrolyte forming a metallic compound film with weak-atomic bonding. The adhesion property of this film is stronger than that of electroplating. This process is fast and much cheaper then physical vapor deposition processes. Anti-corrosion capability of the processed bipolar plates was analyzed using chemical and electrochemical methods. The corrosion curves computed by the linear polarization method showed the chemically modified film to have stable chemical and electrochemical characteristics. The surface and bulk electric conductivities, however, decreased slightly. Single cells of the bipolar plates, both with and without the chemically treated aluminum, were assembled for performance tests. The results showed that the single cell with chemically treated bipolar plates had a higher surface contact resistance and a decreased cell performance, but the cell life was longer. Future research efforts need to focus on improving the surface film conductivity and cell performance.
Human β-Defensin 2 Is Expressed and Associated withMycobacterium tuberculosisduring Infection of Human Alveolar Epithelial Cells
Authors: Rivas-Santiago Bruno , Schwander Stephan K. , Sarabia Carmen , Diamond Gill , Klein-Patel Marcia E. , Hernandez-Pando Rogelio , Ellner Jerrold J. , Sada Eduardo
Published: July 2005

To determine the role of human β-defensin 2 (HBD-2) in human tuberculosis, we studied the in vitro induction of HBD-2 gene expression byMycobacterium tuberculosisH37Rv infection in the human lung epithelial cell line A549, in alveolar macrophages (AM), and in blood monocytes (MN) by reverse transcription-PCR. We also studied the induction of HBD-2 gene expression by mannose lipoarabinomannan (manLAM) fromM. tuberculosis. Intracellular production of HBD-2 peptide was detected by immunocytochemistry and electron microscopy. Our results demonstrated that there was induction of HBD-2 mRNA in A549 cells after infection withM. tuberculosisat various multiplicities of infection (MOI) and that there was stimulation with manLAM. AM expressed the HBD-2 gene only at a high MOI withM. tuberculosis. MN did not express HBD-2 at any of the experimentalM. tuberculosisMOI. Immunostaining revealed the presence of intracellular HBD-2 peptide in A549 cells following infection withM. tuberculosis, and the staining was more intense in areas where there wereM. tuberculosisclusters. By using electron microscopy we also demonstrated production of HBD-2 afterM. tuberculosisinfection and adherence of HBD-2 to the membranes ofM. tuberculosis. Alveolar epithelial cells are among the first cells to encounterM. tuberculosisfollowing aerogenic infection. As HBD-2 has been shown to control growth ofM. tuberculosisand has chemotactic activity, our results suggest that HBD-2 induction byM. tuberculosismay have a role in the pathogenesis of human tuberculosis.
Capsule and Fimbria Interaction inKlebsiella pneumoniae
Authors: Schembri Mark A. , Blom Jens , Krogfelt Karen A. , Klemm Per
Published: July 2005

The capsular polysaccharide and type 1 fimbriae are two of the major surface-located virulence properties associated with the pathogenesis ofKlebsiella pneumoniae. The capsule is an elaborate polysaccharide matrix that encases the entire cell surface and provides resistance against many host defense mechanisms. In contrast, type 1 fimbriae are thin adhesive thread-like surface organelles that can extend beyond the capsular matrix and mediated-mannose-sensitive adhesion to host epithelial cells. These fimbriae are archetypical and consist of a major building block protein (FimA) that comprises the bulk of the organelle and a tip-located adhesin (FimH). It is assumed that the extended major-subunit protein structure permits the FimH adhesin to function independently of the presence of a capsule. In this study, we have employed a defined set ofK. pneumoniaecapsulated and noncapsulated strains to show that the function of type 1 fimbriae is actually impeded by the concomitant expression of a polysaccharide capsule. Capsule expression had significant effects on two parameters commonly used to define FimH function, namely, yeast cell agglutination and biofilm formation. Our data suggest that this effect is not due to transcriptional/translational changes in fimbrial gene/protein expression but rather the result of direct physical interference. This was further demonstrated by the fact that we could restore fimbrial function by inhibiting capsule synthesis. It remains to be determined whether the expression of these very different surface components occurs simply via random events of phase variation or in a coordinated manner in response to specific environmental cues.
Enhancing the Protective Efficacy of
Mycobacterium bovis
BCG Vaccination against Tuberculosis by Boosting with the
Mycobacterium tuberculosis
Major Secretory Protein
Authors: Horwitz Marcus A. , Harth Günter , Dillon Barbara Jane , Masleša-Galić Saša
Published: July 2005

Tuberculosis continues to ravage humanity, killing 2 million people yearly. Most cases occur in areas of the world to which the disease is endemic, where almost everyone is vaccinated early in life with
Mycobacterium bovis
BCG, the currently available vaccine against tuberculosis. Thus, while more-potent vaccines are needed to replace BCG, new vaccines are also needed to boost the immune protection of the 4 billion people already vaccinated with BCG. Until now, no booster vaccine has been shown capable of significantly enhancing the level of protective immunity induced by BCG in the stringent guinea pig model of pulmonary tuberculosis, the “gold standard” for testing tuberculosis vaccines. In this paper, we describe a booster vaccine for BCG comprising the purified recombinant
Mycobacterium tuberculosis
30-kDa protein, the major secreted protein of this pathogen. In the guinea pig model of pulmonary tuberculosis, boosting BCG-immunized animals once with the 30-kDa protein greatly increased cell-mediated and humoral immune responses to the protein in three consecutive experiments. Most importantly, boosting BCG-immunized animals once with the 30-kDa protein significantly enhanced protective immunity against aerosol challenge with highly virulent
M. tuberculosis
, as evidenced by a significantly reduced lung and spleen burden of
M. tuberculosis
compared with those for nonboosted BCG-immunized animals (mean additional reduction in CFU of 0.4 ± 0.1 log in the lung [
P
= 0.03] and 0.6 ± 0.1 log in the spleen [
P
= 0.002]). This study suggests that administering BCG-immunized people a booster vaccine comprising the 30-kDa protein may enhance their level of immunoprotection against tuberculosis.
Fsr-Independent Production of Protease(s) May Explain the Lack of Attenuation of an
Enterococcus faecalis fsr
Mutant Versus a
gelE
-
sprE
Mutant in Induction of Endocarditis
Authors: Singh Kavindra V. , Nallapareddy Sreedhar R. , Nannini Esteban C. , Murray Barbara E.
Published: July 2005

An
Enterococcus faecalis gelE
insertion disruption mutant (TX5128), which produces neither gelatinase (GelE) nor the cotranscribed (in the wild type) serine protease (SprE), was found to be attenuated in a rat endocarditis model with a significant decrease in the endocarditis induction rate versus wild-type
E. faecalis
OG1RF (GelE
+
, SprE
+
). TX5266, which has a nonpolar deletion in
fsrB
and, like TX5128, is phenotypically GelE
−
under usual conditions, was also studied;
fsrB
is a homologue of
agrB
of staphylococci and participates in regulation of
gelE-sprE
expression. Unexpectedly, TX5266 approximated wild-type OG1RF in the endocarditis model and was significantly less attenuated than TX5128. This is in contrast to other models which have found
fsr
mutants to be as or more attenuated than TX5128. Further study found that the
fsrB
mutant produced very low levels of gelatinase activity after prolonged incubation in vitro versus no gelatinase activity with TX5128 and did not show the extensive chaining characteristic of TX5128. Reverse transcription-PCR confirmed that
gelE
was expressed in TX5266 at a very low level versus wild-type OG1RF and was not expressed at all in TX5128. Possible explanations for the increased induction of endocarditis by TX5266 versus TX5128 include the production of low levels of protease(s) or some other effect(s) of the inactivation of the
E. faecalis fsr
regulator. The equivalent ability of OG1RF and its
fsr
mutant to initiate endocarditis may explain why we did not find naturally occurring
fsr
mutants, which account for ca. 35% of
E. faecalis
isolates, unrepresented in endocarditis versus fecal isolates (J. C. Roberts, K. V. Singh, P. C. Okhuysen, and B. E. Murray, J. Clin. Microbiol.
42:
2317-2320, 2004).
In Vitro Cellular Immune Responses to Recombinant Antigens ofMycobacterium aviumsubsp.paratuberculosis
Authors: Shin Sung Jae , Chang Chao-Fu , Chang Ching-Dong , McDonough Sean P. , Thompson Belinda , Yoo Han Sang , Chang Yung-Fu
Published: July 2005

Five recombinant antigens (Ags; 85A, 85B, 85C, superoxide dismutase [SOD], and 35-kDa protein) were purified fromMycobacterium aviumsubsp.paratuberculosisand evaluated for their ability to stimulate peripheral blood mononuclear cells (PMBCs) from fecal-culture-positive cows (low and medium shedders) and culture-negative healthy cows. Recombinant Ags 85A, 85B, and 85C induced significant lymphocyte proliferation as well as the production of gamma interferon (IFN-γ), interleukin-2 (IL-2), IL-12, and tumor necrosis factor alpha (TNF-α), but not IL-4, from low and medium shedders. The 85 antigen complex did not stimulate PMBC proliferation from culture-negative healthy cows. The 35-kDa protein also induced significant lymphocyte proliferation as well as the production of IFN-γ and IL-4 from low and medium shedders. CD4+T cells and CD25+(IL-2R) T cells were stimulated the most by 85A and 85B, while the 35-kDa protein primarily stimulated CD21+B cells involved in humoral immune responses. Interestingly, SOD was less immunostimulatory than other antigens but strongly induced γδ+T cells, which are thought to be important in the early stages of infection, such as pathogen entry. These data provide important insight into how improved vaccines against mycobacterial infections might be constructed.
LcrV Plague Vaccine with Altered Immunomodulatory Properties
Authors: Overheim Katie A. , DePaolo R. William , DeBord Kristin L. , Morrin Elizabeth M. , Anderson Debra M. , Green Nathaniel M. , Brubaker Robert R. , Jabri Bana , Schneewind Olaf
Published: July 2005

Yersinia pestis, the causative agent of plague, secretes LcrV (low-calcium-response V or V antigen) during infection. LcrV triggers the release of interleukin 10 (IL-10) by host immune cells and suppresses proinflammatory cytokines such as tumor necrosis factor alpha and gamma interferon as well as innate defense mechanisms required to combat the pathogenesis of plague. Although immunization of animals with LcrV elicits protective immunity, the associated suppression of host defense mechanisms may preclude the use of LcrV as a human vaccine. Here we show that short deletions within LcrV can reduce its immune modulatory properties. An LcrV variant lacking amino acid residues 271 to 300 (rV10) elicited immune responses that protected mice against a lethal challenge withY. pestis. Compared to full-length LcrV, rV10 displayed a reduced ability to release IL-10 from mouse and human macrophages. Furthermore, the lipopolysaccharide-stimulated release of proinflammatory cytokines by human or mouse macrophages was inhibited by full-length LcrV but not by the rV10 variant. Thus, it appears that LcrV variants with reduced immune modulatory properties could be used as a human vaccine to generate protective immunity against plague.
Cytokine and Chemokine Responses Associated with Clearance of a Primary
Salmonella enterica
Serovar Typhimurium Infection in the Chicken and in Protective Immunity to Rechallenge
Authors: Withanage G. S. K. , Wigley Paul , Kaiser Pete , Mastroeni Pietro , Brooks Heather , Powers Claire , Beal Richard , Barrow Paul , Maskell Duncan , McConnell Ian
Published: July 2005

Infection of poultry with
Salmonella enterica
serovar Typhimurium poses a significant risk to public health through contamination of meat from infected animals. Vaccination has been proposed to control infections in chickens. However, the vaccines are currently largely empirical, and our understanding of the mechanisms that underpin immune clearance and protection in avian salmonellosis is not complete. In this study we describe the cytokine, chemokine, and antibody responses and cellular changes in primary and secondary infections of chickens with
Salmonella
serovar Typhimurium. Infection of 1-week-old chickens induced early expression of a macrophage inflammatory protein (MIP) family chemokine in the spleen and liver, followed by increased expression of gamma interferon accompanied by increased numbers of both CD4
+
and CD8
+
T cells and the formation of granuloma-like follicular lesions. This response correlated with a Th1-mediated clearance of the systemic infection. Primary infection also induced specific immunoglobulin M (IgM), IgG, and IgA antibody responses. In contrast to previously published studies performed with newly hatched chicks, the expression levels of proinflammatory cytokines in the gastrointestinal tract were not greatly increased following infection. However, significant expression of the anti-inflammatory cytokine transforming growth factor β4 was detected in the gut early in infection. Following secondary challenge, the birds were fully protected against systemic infection and showed a high level of protection against gastrointestinal colonization. Rapid expression of the MIP family chemokine and interleukin-6 was detected in the guts of these birds and was accompanied by an influx of lymphocytes. Increased levels of serum IgA-specific antibodies were also found following rechallenge. These findings suggest that cellular responses, particularly Th1 responses, play a crucial role in immune clearance in avian salmonellosis and that protection against rechallenge involves the rapid recruitment of cells to the gastrointestinal tract. Additionally, the high levels of inflammatory response found following
Salmonella
serovar Typhimurium infection of newly hatched chicks were not observed following infection of older birds (1 week old), in which the expression of regulatory cytokines appeared to limit inflammation.
Staphylococcus aureusPeptidoglycan Is a Toll-Like Receptor 2 Activator: a Reevaluation
Authors: Dziarski Roman , Gupta Dipika
Published: July 2005

Since the ability of peptidoglycan (PGN) to activate Toll-like receptor 2 (TLR2) was recently questioned, we reevaluated activation of TLR2 by PGN. Polymeric soluble or insolubleStaphylococcus aureusPGN, repurified by sodium dodecyl sulfate or phenol extraction, activated TLR2 at 0.1 to 1 or 10 μg/ml, respectively, and induced tumor necrosis factor alpha production. The TLR2 activation by PGN, but not by lipoteichoic acid, was abolished by muramidase digestion. We conclude that polymericS. aureusPGN is a TLR2 activator.
Selective Capture ofSalmonella entericaSerovar Typhi Genes Expressed in Macrophages That Are Absent from theSalmonella entericaSerovar Typhimurium Genome
Authors: Faucher Sébastien P. , Curtiss Roy , Daigle France
Published: July 2005

Thirty-sixSalmonella entericaserovar Typhi-specific genes, absent from theSalmonella entericaserovar Typhimurium genome, that were expressed in human macrophages were identified by selective capture of transcribed sequences. These genes are located on 15 unique loci of the serovar Typhi genome, includingSalmonellapathogenicity islands (SPI-7, SPI-8, and SPI-10) and bacteriophages (ST15, ST18, and ST35).
Investigation of Oxidative Stress Defenses of
Neisseria gonorrhoeae
by Using a Human Polymorphonuclear Leukocyte Survival Assay
Authors: Seib Kate L. , Simons Mark P. , Wu Hsing-Ju , McEwan Alastair G. , Nauseef William M. , Apicella Michael A. , Jennings Michael P.
Published: July 2005

Neisseria gonorrhoeae
has well-characterized oxidative stress defense systems that protect against oxidative killing in in vitro assays. In contrast, mutant strains of
N. gonorrhoeae
lacking oxidative stress defenses are identical to the wild type when tested in an ex vivo survival assay using human polymorphonuclear leukocytes.
TOWARDS A GRID SERVICES BASED FRAMEWORK FOR THE VIRTUALIZATION, EXECUTION AND COMPOSITION OF MPI APPLICATIONS
Authors: FLOROS EVANGELOS , COTRONIS YIANNIS
Published: July 2005

We present Quantify, a programming framework for exposing high-performance parallel MPI applications using Grid Services. The two distinctive programming styles of Grid Services and MPI are bridged using a data-centric virtualization approach through the notion of Uses and Provides Quantities. Quantities are used to describe an abstract application interface, permit data exchange between applications and facilitate the composition of two or more applications in a service workflow. Uses and Provides Quantities are modelled using Service Data Elements (SDEs). Finally we demonstrate the applicability of the framework using a Flood Crisis application scenario.
PARALLEL LOOP SCHEDULING APPROACHES FOR DISTRIBUTED AND SHARED MEMORY SYSTEMS
Authors: AGUILAR JOSE , LEISS ERNST
Published: July 2005

In this paper, we propose different approaches for the parallel loop scheduling problem on distributed as well as shared memory systems. Specifically, we propose adaptive loop scheduling models in order to achieve load balancing, low runtime scheduling, low synchronization overhead and low communication overhead. Our models are based on an adaptive determination of the chunk size and an exploitation of the processor affinity property, and consider different situations (central or local queues, and dynamic or static loop partition).
A Performance Model of Software-Based Deadlock Recovery Routing Algorithm in Hypercubes
Authors: KHONSARI A. , SARBAZI-AZAD H. , OULD-KHAOUA M.
Published: July 2005

Recent studies have revealed that deadlocks are generally infrequent in the network. Thus the hardware resources, e.g. virtual channels, dedicated for deadlock avoidance are not utilised most of the time. This consideration has motivated the development of novel adaptive routing algorithms with deadlock recovery. This paper describes a new analytical model to predict message latency in hypercubes with a true fully adaptive routing algorithm with progressive deadlock recovery. One of the main features of the proposed model is the use of results from queueing systems with impatient customers to capture the effects of the timeout mechanism used in this routing algorithm for deadlock detection. The validity of the model is demonstrated by comparing analytical results with those obtained through simulation experiments.
AN EFFICIENT PARALLEL ALGORITHM TO EVOLVE SIMULATIONS OF THE CELLULAR POTTS MODEL
Authors: GUSATTO ÉDER , MOMBACH JOSÉ C. M. , CERCATO FERNANDO P. , CAVALHEIRO GERSON H.
Published: July 2005

Applications of the cellular Potts model to investigate cellular structures are becoming widely spread in the scientific literature. Despite its realism and generality, the standard Monte Carlo algorithm used to evolve this model in the scientific literature lacks computational efficiency. As an alternative we introduce the Random Walker algorithm that is a modified Monte Carlo procedure of simpler parallelization. We test it in cell sorting and foam coarsening simulations obtaining velocity increase factors of 10 and 3 times, respectively, in relation to the standard algorithm. The results obtained with these simulations are equivalent to those obtained with the standard algorithm.
THE COMPLEXITY OF THE MAXIMAL REQUESTS SATISFACTION PROBLEM IN MULTIPOINT COMMUNICATION
Authors: BARTH DOMINIQUE , BERTHOME PASCAL , FRAGOPOULOU PARASKEVI
Published: July 2005

A multipoint request is a group of collaborating nodes that wish to establish a communication for a certain duration of time. This need arises in parallel applications executed on processing elements connected either by specialized interconnection networks or over wide area networks (collective communication operations). Each individual request is satisfied by a given subtree connecting the participating nodes. We aim to maximize the number of requests that can be simultaneously satisfied. In this paper, we show that this problem is NP-complete and we propose for it an approximation algorithm provided that the number of requests using the same edge is bounded by a constant.
CONCENTRATED SUSPENSIONS UNDER FLOW: SHEAR-THICKENING AND JAMMING
Authors: HÉBRAUD PASCAL , LOOTENS DIDIER
Published: July 2005

When a concentrated suspension of colloidal particles is sheared at high enough shear rates, its viscosity increases with the shear rate. Depending on the details of the interactions between particles, this increase may be continuous and the suspension is said to shear-thicken, or may be discontinuous, leading to an arrest of flow: the suspension jams. We review recent experimental evidence that both behaviors are the consequence of the formation of dynamical aggregates under flow.
EPR AND OPTICAL STUDIES OF VANADYL IONS IN ALKALI LEAD BOROTELLURITE GLASSES
Authors: SREEKANTH CHAKRADHAR R. P. , SIVARAMAIAH G. , LAKSHMANA RAO J. , GOPAL N. O.
Published: July 2005

Electron Paramagnetic Resonance (EPR) and optical absorption spectra of VO 2+ ions in different alkali lead borotellurite glasses have been studied. The spin-Hamiltonian parameters (g and A), bonding parameter [Formula: see text] and Fermi contact interaction parameter k have been calculated. The values of spin-Hamiltonian parameters confirm that the vanadyl ions are present in the glasses as VO 2+ molecular ions in an octahedral site with a tetragonal compression. The number of spins (N) participating in resonance is calculated as a function of temperature (123–393 K) for 9 mol% of VO 2+ ions in lithium lead borotellurite glass sample. It is observed that N obeys the Boltzmann law. From EPR data, the paramagnetic susceptibility (χ) is calculated at various temperatures and the Curie constant has been evaluated from 1/χ–T graph. The optical absorption spectrum exhibits two bands characteristic of VO 2+ ions in tetragonal symmetry. The band gap (E opt ) and the Urbach energies (ΔE) have been determined from the ultraviolet absorption edges and are found to be dependant on the size of the alkali ion. The theoretical values of optical basicity (Λ th ) of these glasses have also been evaluated.
NEW GEOMETRIC FORMALISM FOR GRAVITY EQUATION IN EMPTY SPACE
Authors: HUANG XIN-BING
Published: July 2005

In this paper, a complex daor field which can be regarded as the square root of space–time metric is proposed to represent gravity. The locally complexified geometry is set up, and the complex spin connection constructs a bridge between gravity and SU(1, 3) gauge field. Daor field equations in empty space are acquired, which are one-order differential equations and do not conflict with Einstein's gravity theory.
EMPIRICAL FOUNDATIONS OF THE RELATIVISTIC GRAVITY
Authors: NI WEI-TOU
Published: July 2005

In 1859, Le Verrier discovered the mercury perihelion advance anomaly. This anomaly turned out to be the first relativistic-gravity effect observed. During the 141 years to 2000, the precisions of laboratory and space experiments, and astrophysical and cosmological observations on relativistic gravity have been improved by 3 orders of magnitude. In 1999, we envisaged a 3–6 order improvement in the next 30 years in all directions of tests of relativistic gravity. In 2000, the interferometric gravitational wave detectors began their runs to accumulate data. In 2003, the measurement of relativistic Shapiro time-delay of the Cassini spacecraft determined the relativistic-gravity parameter γ to be 1.000021 ± 0.000023 of general relativity — a 1.5-order improvement. In October 2004, Ciufolini and Pavlis reported a measurement of the Lense–Thirring effect on the LAGEOS and LAGEOS2 satellites to be 0.99 ± 0.10 of the value predicted by general relativity. In April 2004, Gravity Probe B (Stanford relativity gyroscope experiment to measure the Lense–Thirring effect to 1%) was launched and has been accumulating science data for more than 170 days now. μSCOPE (MICROSCOPE: MICRO-Satellite à trainée Compensée pour l'Observation du Principle d'Équivalence) is on its way for a 2008 launch to test Galileo equivalence principle to 10-15. LISA Pathfinder (SMART2), the technological demonstrator for the LISA (Laser Interferometer Space Antenna) mission is well on its way for a 2009 launch. STEP (Satellite Test of Equivalence Principle), and ASTROD (Astrodynamical Space Test of Relativity using Optical Devices) are in good planning stage. Various astrophysical tests and cosmological tests of relativistic gravity will reach precision and ultra-precision stages. Clock tests and atomic interferometry tests of relativistic gravity will reach an ever-increasing precision. These will give revived interest and development both in experimental and theoretical aspects of gravity, and may lead to answers to some profound questions of gravity and the cosmos.
PSEUDOPOTENTIAL STUDIES ON THE ELECTRONIC STRUCTURE OF LANTHANUM MONOHALIDES LaF, LaCl, LaBr, AND LaI
Authors: CAO XIAOYAN , DOLG MICHAEL
Published: July 2005

Relativistic energy-consistent small-core lanthanide pseudopotentials of the Stuttgart–Köln variety and corresponding valence basis sets have been used for the investigation of the ground state (1Σ+) lanthanum monohalides LaF , LaCl , LaBr , and LaI . The molecular constants were derived from coupled-cluster calculations, taking into account corrections for atomic spin-orbit splitting as well as basis set superposition errors. With the exception of the binding energies for LaI the theoretical values for LaF (Re = 2.034 Å, De = 6.73 eV , ωe = 574 cm -1), LaCl (Re = 2.517 Å, De = 5.11 eV , ωe = 339 cm -1), LaBr (Re = 2.664 Å, De = 4.47 eV , ωe = 236 cm -1), and LaI (Re = 2.891 Å, De = 3.65 eV , ωe = 186 cm -1) show good agreement with the experimental data. The calculated binding energy (3.65 eV) for LaI is in-between the two conflicting estimated experimental data (2.97 eV, 4.29 eV).
MECHANISTIC STUDY OF THE REACTIONS OF SULFUR TRIOXIDE WITH HYDROGEN HALIDES TO FORM SUPERACID AND SURVEY OF HALO-SULFONIC ACID STRENGTH
Authors: WEBER KEVIN H. , HARRIS JULIE A. , LARSON LAURA J. , TAO FU-MING , LI SHUJIN , GU RENAO
Published: July 2005

The reaction mechanisms for the formations of halo-sulfonic acids from sulfur trioxide and hydrogen halides are investigated using density functional theory. Two channels of reaction are considered: the binary SO 3 + HX reaction pathway and the ternary SO 3 + 2 HX pathway. Equilibrium geometries, harmonic frequencies, and relative energies of the reactant, transition state, and product clusters are calculated at the B3LYP/6-311++G** level. Hydrogen fluoride was found to have a particularly strong interaction with SO 3, forming an electron donor acceptor complex. Similarities to the hydrolysis of SO 3 to form sulfuric acid are discussed and the relative acidities of the halo-sulfonic acid series are evaluated and compared in the same context to sulfuric and perchloric acids.
ISOLOBAL BORON CARBONYL CARBOCATION ANALOGS
Authors: WANG ZHI-XIANG , CHEN ZHONGFANG , JIAO HAIJUN , VON RAGUÉ SCHLEYER PAUL
Published: July 2005

The isolobal [Formula: see text] relationship has been applied computationally to create a new family of positively charged boron carbonyls. These are generated by replacing one or more of the CH's in carbocations by BCO groups. The boron carbonyl cations can be hypercoordinated (e.g. H4BCO +, isolobal with [Formula: see text]), hydrogen bridged (e.g. ( BCO )2 H +, isolobal with the bridged vinyl cation [Formula: see text]), carbon bridged (e.g. [Formula: see text], isolobal with the 2-norbornyl cation), and polyhedral (e.g. [Formula: see text], isolobal with C 4 v [Formula: see text]). Furthermore, the BCO analogs have geometries and electronic structures similar to those of their carbocation counterparts, for example, characterized by 3c-2e multicenter and aromatic six interstitial electron bonding. The nucleus-independent chemical shifts (NICS) at the centers of three-membered rings or the pyramidal clusters are highly diatropic, ranging from -28 to -45 ppm. The replacement of CH by BCO favors the hypercoordinate bonding characteristic of boron compounds due to the more diffuse orbitals and lower electronegativity of boron.
Smooth muscle adherens junctions associated proteins are stable at the cell periphery during relaxation and activation
Authors: Eddinger Thomas J. , Schiebout Jessen D. , Swartz Darl R.
Published: July 2005

This study was performed to determine the stability of the adherens junction (AJ)-associated proteins at the smooth muscle cell (SMC) plasma membrane during relaxing and activating conditions. Dog stomach, ileum, colon, and trachea tissues were stored in Ca2+-free PSS or regular PSS or were activated in 10 μM carbachol in PSS before rapid freezing. The tissues were subsequently sectioned and immunoreacted using antibodies for vinculin, talin, fibronectin, and caveolin to determine their cellular distribution in these tissues under these conditions. In all four tissues and under all three conditions, the distribution of these four proteins remained localized to the periphery of the cell. In transverse tissue sections, the AJ-associated proteins formed a distinct punctate pattern around the periphery of the SMCs at the plasma membrane. These domains alternated with the caveolae (as identified by the presence of caveolin). In longitudinal tissue sections, the AJ-associated proteins formed continuous tracks or staves, while the caveolae remained punctate in this dimension as well. Caveolin is not present in the tapered ends of the SMCs, where the AJ-associated proteins appear continuous around the periphery. Densitometry of the fluorophore distribution of these proteins showed no shift in their localization from the SMC periphery when the tissues were relaxed or when they were activated before freezing. These results suggest that under physiologically relaxing and activating conditions, AJ-associated proteins remain stably localized at the plasma membrane.
Angiotensin II-induced activation of p21-activated kinase 1 requires Ca2+ and protein kinase Cδ in vascular smooth muscle cells
Authors: Woolfolk Elethia A. , Eguchi Satoru , Ohtsu Haruhiko , Nakashima Hidekatsu , Ueno Hikaru , Gerthoffer William T. , Motley Evangeline D.
Published: July 2005

ANG II promotes remodeling of vascular smooth muscle cells (VSMCs) in cardiovascular diseases. It has been shown to activate p21-activated kinase (PAK)1, a critical component of signaling pathways implicated in growth and migration. However, the detailed signaling mechanism by which ANG II induces PAK1 activation in VSMCs remains unclear. Therefore, we have examined the mechanism required for activation of PAK1 by ANG II in VSMCs. ANG II, through activation of the ANG II type 1 receptor, rapidly promotes phosphorylation of PAK1 in VSMCs via a pathway independent of transactivation of the epidermal growth factor receptor. Using selective agonists and inhibitors, we demonstrated that mobilization of intracellular Ca2+ and PKCδ activation are required for ANG II-induced PAK1 phosphorylation. Rottlerin, a PKCδ inhibitor, significantly blocked ANG II-induced PAK1 phosphorylation. Further support for this notion was provided through infection of VSMCs with adenovirus encoding a dominant-negative (dn)PKCδ, which also markedly reduced phosphorylation of PAK1 by ANG II. In this pathway, Ca2+ acts upstream of PKCδ because a Ca2+ ionophore rapidly induced PKCδ phosphorylation at Tyr311 and Ca2+-dependent PAK1 phosphorylation was blocked by rottlerin. In addition, dnPYK-2, dnRac, and antioxidants inhibited ANG II-induced PAK1 phosphorylation, suggesting that PYK-2, Rac, and reactive oxygen species are involved in the upstream signaling. Finally, dnPAK1 markedly inhibited ANG II-induced protein synthesis in VSMCs. These data provide a novel signaling pathway by which ANG II may contribute to vascular remodeling.