bluuebunny/crossref_metadata_2025 huggingface dataset:
Potential of Polygeneration With Solar Thermal and Photovoltaic Systems
Authors: Kribus Abraham , Mittelman Gur
Published: January 2008

The efficiency of both solar thermal and photovoltaic (PV) systems for power generation is usually in the range of 10–30%, meaning that more than two-thirds of the collected radiation energy is lost. Cogeneration, or more generally polygeneration, means capturing and using some of the wasted energy and therefore increasing the overall efficiency of the solar conversion. Several paths of solar polygeneration are investigated: both thermal and photovoltaic receivers, with use of the waste heat to generate additional electricity by a heat engine, a direct use as heat, and use of the waste heat to operate a thermal process (absorption cooling). Appropriate optical and thermal energy losses are taken into account in all cases. The receiver temperature and the sunlight concentration level serve as free parameters. It is shown that concentrating the solar radiation is essential to effective polygeneration, and that there is an optimal operating temperature for each system. Polygeneration leads to increased conversion efficiency in all cases, and the scenarios based on PV show better results than those based on thermal converters. Scenarios showing electricity replacement up to 43% (normalized to the incident radiation) are presented.
Field Test of Water-Steam Separators for Direct Steam Generation in Parabolic Troughs
Authors: Eck Markus , Schmidt Holger , Eickhoff Martin , Hirsch Tobias
Published: January 2008

Direct steam generation (DSG) represents a promising option to improve today’s parabolic trough technology for solar thermal power generation. The European DISS and INDITEP projects have proven the feasibility of the DSG process under real solar conditions at the DISS test facility at the Plataforma Solar de Almería (PSA) (Zarza, E., Valenzuela, L., Léon, J., Hennecke, K., Eck, M., Weyers, H.-D., Eickhoff, M., 2004, “Direct Steam Generation in Parabolic Troughs Final Results and Conslusions of the DISS Project,” Energy, 29, pp. 635–644). These projects have also shown that the recirculation mode is the preferred operation mode for DSG collector fields. This concept requires water-steam separators at the end of the evaporation section of the collector loop. Both compact water-steam separators for every single row or huge separation drums for the whole collector field are considered. Small compact water-steam separators show a lower inertia, reducing the time for start-up. Within INDITEP and the German R&D project SOLDI compact water-steam separators have been developed, manufactured, and tested by DLR and Siemens, with its subcontractor Framatome ANP. Prototypes of a cyclone and a baffle separator have been implemented into the DISS test facility. More than 200 tests have been performed to investigate the separation efficiency, the pressure loss, and the performance under transient conditions. This paper focuses on the steady-state tests.
Automatic Noncontact Quality Inspection System for Industrial Parabolic Trough Assembly
Authors: Pottler Klaus , Röger Marc , Lüpfert Eckhard , Schiel Wolfgang
Published: January 2008

The construction of solar thermal power plants with several thousand m2 of collector area requires quality control measures for components, subsystems, and the entire collector rows. While quality control has a significant potential to increase the solar field efficiency, the main objective is to assure high-quality standards for the whole solar field. Quality control, assembly documentation, and performance measurements are required by the investors. Based on previous R&D work in collector development and prototype qualification, measurement systems have been developed for use in solar field construction and operation supervision. In particular, close-range photogrammetry can be used to measure the geometry of collector steel structures. The measurement system consists of a digital camera, which moves around the structure automatically while shooting photos of the concentrator structure from various positions. The photos are evaluated with photogrammetry software to check the assembly quality. The whole measurement and evaluation procedure is computer controlled and is fast enough to be integrated in a solar collector production line. This paper deals with the required measurement accuracy and shows ways to reach, maintain, and control this accuracy in the rough environment of an on-site production line.
Slope Measurements of Parabolic Dish Concentrators Using Color-Coded Targets
Authors: Ulmer Steffen , Heller Peter , Reinalter Wolfgang
Published: January 2008

A new fast and highly accurate method for measuring the slope errors of parabolic dish concentrators has been developed. This method uses a flat target with colored stripes placed close to the focal plane of the concentrator and a digital camera located at an observation point on the optical axis at some distance from it. A specially developed image analysis algorithm detects the different colors of the images of the reflection of the target in the concentrator and assigns them their known position on the color target. This information, along with the geometry of the measurement setup and the theoretical parabolic shape of the concentrator, is used to calculate the normal vectors of the concentrator surface. From these normal vectors, the radial and tangential slopes can be calculated and compared to the design values of the concentrator. The resulting slope errors not only give the total concentrator error for general characterization of the dish but also indicate systematic errors from fabrication and installation with a high spatial resolution. In order to verify the quality of the results obtained, a ray-tracing code was developed that calculates the flux distribution on planes perpendicular to the optical axis. Measured slope errors of a 8.5m dish concentrator are presented and the calculated flux distributions are compared to measured flux distributions. The comparison shows excellent agreement in the flux distribution on the absorber plane. This verifies the promising potential of this fast and highly precise new method for measuring imperfections in dish concentrator shape.
Assessment of SEGS-Like Power Plants for the Brazilian Northeast Region
Authors: Cavalcanti E. S. C. , Petti A. C. G.
Published: January 2008

The potential for parabolic trough solar power plant implementation in the semiarid area located at the Brazilian northeast region, throughout the São Francisco river basin, has been estimated as being 94,190MWe, based on the simulation results of a typical 30MWe solar energy generating systems (SEGS)-like power plant modeled using experimental solar irradiation measured at an eligible site. The use of electricity generated with SEGS-like power plants will help to save water that otherwise will be necessary to run in hydroelectric turbines and will contribute to diversify the Brazilian electrical energy matrix, which is predominantly hydroelectrical. The equivalent volume flow rate that can be saved with the implementation of solar power potential was estimated as 5125m3∕s, which is 1.8 times the mean flow rate of the São Francisco river.
DNA Oxidation as Triggered by H3K9me2 Demethylation Drives Estrogen-Induced Gene Expression
Authors: Perillo Bruno , Ombra Maria Neve , Bertoni Alessandra , Cuozzo Concetta , Sacchetti Silvana , Sasso Annarita , Chiariotti Lorenzo , Malorni Antonio , Abbondanza Ciro , Avvedimento Enrico V.
Published: January 2008

Modifications at the N-terminal tails of nucleosomal histones are required for efficient transcription in vivo. We analyzed how H3 histone methylation and demethylation control expression of estrogen-responsive genes and show that a DNA-bound estrogen receptor directs transcription by participating in bending chromatin to contact the RNA polymerase II recruited to the promoter. This process is driven by receptor-targeted demethylation of H3 lysine 9 at both enhancer and promoter sites and is achieved by activation of resident LSD1 demethylase. Localized demethylation produces hydrogen peroxide, which modifies the surrounding DNA and recruits 8-oxoguanine–DNA glycosylase 1 and topoisomeraseIIβ, triggering chromatin and DNA conformational changes that are essential for estrogen-induced transcription. Our data show a strategy that uses controlled DNA damage and repair to guide productive transcription.
Delicious Tales of Guinea Pigs, Etc.
Authors: Smocovitis Vassiliki Betty
Published: January 2008

A Guinea Pig's History of Biology
. The Plants and Animals Who Taught Us the Facts of Life.
By Jim Endersby
. Heinemann (Random House), London, 2007. 511 pp. £20. ISBN 9780434012596. Harvard University Press, Cambridge, MA. $27.95. ISBN 9780674027138.

This account for lay readers approaches the history of heredity and genetics through influential examples of the organisms that biologists studied in developing our current understanding.
Early Diagnosis of Leptospirosis by Immunoglobulin M Immunoblot Testing
Authors: Doungchawee Galayanee , Kositanont Uraiwan , Niwetpathomwat Anuchai , Inwisai Tasanee , Sagarasaeranee Plyyonk , Haake David A.
Published: January 2008

There is an urgent need for the development of serodiagnostic approaches with improved sensitivity for patients with acute leptospirosis. Immunoblots were performed on 188 sera collected from 74 patients with laboratory-confirmed early leptospiral infection to detect immunoglobulin M (IgM) antibodies to antigens pooled from 10 leptospiral strains prevalent in Thailand. Sera from patients with other febrile diseases served as controls. IgM reactivity to seven distinct antigens, with apparent molecular masses of 14 to 18, 19 to 23, 24 to 30, 32, 35/36, 37, and 41/42 kDa, was observed. The low-molecular-mass 14- to 18-kDa band was the most frequently detected antigen, being recognized in sera from 82.4% of patients during the first 3 days after the onset of symptoms. We evaluated the accuracy of the IgM immunoblot (IgM-IB) test by using reactivity to the 14- to 18-kDa band and/or at least two bands among the 19- to 23-, 24- to 30-, 32-, 35/36-, 37-, and 41/42-kDa antigens as the diagnostic criterion. The sensitivities of the IgM-IB test and the microscopic agglutination test (MAT) were 88.2% and 2.0%, respectively, with sera from patients 1 to 3 days after the onset of symptoms. In contrast, the IgM-IB test was positive with only 2/48 (4.2%) sera from patients with other febrile illnesses. The high sensitivity and specificity of the IgM-IB test for acute leptospirosis would provide greatly improved diagnostic accuracy for identification of patients who would benefit from early antibiotic intervention. In addition, the antigens identified by the IgM-IB test may serve as components of a rapid, accurate, point-of-care diagnostic test for early leptospirosis.
Immunological Responses and Long-Term Treatment Interruption after Human Immunodeficiency Virus Type 1 (HIV-1) Lipopeptide Immunization of HIV-1-Infected Patients: the LIPTHERA Study
Authors: Pialoux Gilles , Quercia Romina P. , Gahery Hanne , Daniel Nathalie , Slama Laurence , Girard Pierre-Marie , Bonnard Philippe , Rozenbaum Willy , Schneider Véronique , Salmon Dominique , Guillet Jean-Gérard
Published: January 2008

We studied the time course of immunological and virological markers after highly active antiretroviral therapy (HAART) interruption in chronically human immunodeficiency virus type 1 (HIV-1)-infected patients immunized with an HIV lipopeptide preparation. In a prospective open pilot study, 24 HIV-1-infected HAART-treated patients with undetectable plasma viral loads (pVLs) and CD4+T-cell counts above 350/mm3were immunized at weeks 0, 3, and 6 with a candidate vaccine consisting of six HIV lipopeptides. At week 24, patients with pVLs of <1.7 log10copies/ml were invited to stop taking HAART. Antiretroviral therapy was resumed if the pVL rose above 4.47 log10copies/ml and/or if the CD4+cell count fell below 250/mm3. Immunological and virologic parameters were studied before and after HAART interruption. The median baseline and nadir CD4+cell counts were 482 (interquartile range [IQR], 195 to 826) and 313 (IQR, 1 to 481)/mm3, respectively. New specific CD8+cell responses to HIV-1 epitopes were detected after immunization in 13 (57%) of 23 assessable patients. Twenty-one patients were evaluated 96 weeks after HAART interruption. The median time to pVL rebound was 4 weeks (IQR, 2 to 6), and the median peak pVL was 4.26 (IQR, 3 to 5) log10copies/ml. Thirteen of these 21 patients resumed HAART a median of 60 weeks after immunization (IQR, 9.2 to 68.4 weeks), when the median pVL was 4.8 (IQR, 2.9 to 5.7) log10copies/ml and the median CD4+cell count was 551 (IQR, 156 to 778)/mm3. Eight patients were still off therapy at 96 weeks, with a median pVL of 4 (IQR, 1.7 to 4.6) log10copies/ml and a median CD4+cell count of 412 (IQR, 299 to 832)/mm3. No clinical disease progression had occurred. Despite the lack of a control arm, these findings warrant a randomized study of therapeutic vaccination with HIV lipopeptides followed by long-term HAART interruption in AIDS-free chronically infected patients.
Increased Synthesis of Anti-Tuberculous Glycolipid Immunoglobulin G (IgG) and IgA with Cavity Formation in Patients with Pulmonary Tuberculosis
Authors: Mizusawa Masako , Kawamura Mizuoho , Takamori Mikio , Kashiyama Tetsuya , Fujita Akira , Usuzawa Motoki , Saitoh Hiroki , Ashino Yugo , Yano Ikuya , Hattori Toshio
Published: January 2008

Tuberculous glycolipid (TBGL) antigen is a cell wall component ofMycobacterium tuberculosisand has been used for the serodiagnosis of tuberculosis. We investigated correlations between the levels of anti-TBGL antibodies and a variety of laboratory markers that are potentially influenced by tuberculous infection. Comparisons between patients with cavitary lesions and those without cavitary lesions were also made in order to determine the mechanism underlying the immune response to TBGL. Blood samples were obtained from 91 patients with both clinically and microbiologically confirmed active pulmonary tuberculosis (60 male and 31 female; mean age, 59 ± 22 years old). Fifty-nine patients had cavitary lesions on chest X-rays. Positive correlations were found between anti-TBGL immunoglobulin G (IgG) and C-reactive protein (CRP) (r= 0.361;P< 0.001), between anti-TBGL IgA and soluble CD40 ligand (sCD40L) (r= 0.404;P< 0.005), between anti-TBGL IgG and anti-TBGL IgA (r= 0.551;P< 0.0000005), and between anti-TBGL IgM and serum IgM (r= 0.603;P< 0.00000005). The patients with cavitary lesions showed significantly higher levels of anti-TBGL IgG (P< 0.005), anti-TBGL IgA (P< 0.05), white blood cells (P< 0.01), neutrophils (P< 0.005), basophils (P< 0.0005), natural killer cells (P< 0.05), CRP (P< 0.0005), KL-6 (sialylated carbohydrate antigen KL-6) (P< 0.0005), IgA (P< 0.05), and sCD40L (P< 0.01). The observed positive correlations between the anti-TBGL antibody levels and inflammatory markers indicate the involvement of inflammatory cytokines and NKT cells in the immunopathogenesis of pulmonary tuberculosis.
Local Immune Response to Upper Urinary Tract Infections in Children
Authors: Kantele Anu , Palkola Nina , Arvilommi Heikki , Honkinen Olli , Jahnukainen Timo , Mertsola Jussi , Kantele Jussi M.
Published: January 2008

Vaccines are needed against urinary tract infections (UTIs) in children, as episodes of pyelonephritis (PN) may cause renal scarring. Local immune mechanisms are regarded to confer protection, yet they have been poorly characterized for children. This study explores the local immune response in children by looking for newly activated pathogen-specific antibody-secreting cells (ASC), expected to appear transiently in the circulation as a response to UTI. Urinary tract-originating ASC specific to each patient's own pathogen or P fimbria were studied in 37 children with PN. The children were examined for recidivism and renal scarring in a 6-month follow-up study. Pathogen-specific ASC were found in 33/37 children, with the magnitude increasing with age. In contrast to the case for adults, with immunoglobulin A (IgA) dominance, in 18/33 cases IgM dominated the response, and this occurred more frequently in infants (63%) than in older children (30%). The most vigorous response was found to whole
Escherichia coli
bacteria (geometric mean, 63 ± 2,135 ASC/10
6
peripheral blood mononuclear cells [PBMC]), yet responses were found to P fimbriae (13 ± 33 ASC/10
6
PBMC), too. The response peaked at 1 to 2 weeks and was low/negligible 3 to 7 weeks after the beginning of symptoms. Recidivism was seen in seven patients, and renal scarring was seen in nine patients. In conclusion, a response of circulating ASC was found in children with UTIs, with the magnitude increasing with age. Since IgM is not present in urine, the IgM dominance of the response suggests that systemic immune mechanisms are more important in the immune defense in children than in adults. In 81% of patients, no recidivism was seen, suggesting a successful immune defense.
Peripheral Blood Gamma Interferon Release Assays Predict Lung Responses andMycobacterium tuberculosisDisease Outcome in Mice
Authors: Beamer Gillian L. , Flaherty David K. , Vesosky Bridget , Turner Joanne
Published: January 2008

Current diagnostic tests for tuberculosis (TB) are not able to distinguish active disease from latentMycobacterium tuberculosisinfection, nor are they able to quantify the risk of a latently infected person progressing to active TB. There is interest, however, in adapting antigen-specific gamma interferon (IFN-γ) release assays (IGRAs) to predict disease outcome. In this study, we used the differential susceptibilities of inbred mouse strains toM. tuberculosisinfection to evaluate the prognostic capabilities of IGRAs. Using lung and blood cultures, we determined that CBA/J, DBA/2, and C3H/HeJ mice (models of heightened risk of progression to active TB) produced less antigen-specific IFN-γ in response toM. tuberculosisculture filtrate proteins and early secreted antigenic target-6 than the relatively resistant C57BL/6 mouse strain. Additionally, reduced IFN-γ secretion in supernatants reflected a reduced frequency of IFN-γ-responding cells in the lung and blood and not a specific defect in IFN-γ secretion at the single-cell level. Importantly, detection of antigen-specific IFN-γ from blood cultures accurately reflected lung responses, indicating that blood can be an appropriate test tissue in humans. Furthermore, reduced antigen-specific IFN-γ production and low frequencies of IFN-γ-responding cells from peripheral blood predicted increased risk of TB disease progression across genetically diverse TB disease-susceptible mouse strains, suggesting that similar results may occur in humans. The development of efficacious predictive diagnostic tests for humans would lead to targeted therapy prior to progression to active TB, reducing transmission, incidence, and prevalence rates while maximizing the use of public health resources.
Passive Transfer of MaternalMycoplasma hyopneumoniae-Specific Cellular Immunity to Piglets
Authors: Bandrick Meggan , Pieters Maria , Pijoan Carlos , Molitor Thomas W.
Published: January 2008

Immunity in the neonatal animal is primarily maternally derived, either by lymphocytes that pass into the newborn across the placenta or following colostrum ingestion. However, the effect of this passively transferred cellular maternal immunity on the newborn's immune repertoire is not clearly understood. Various studies have shown that colostral lymphocytes are activated and possess functional abilities; however, no studies have shown the transfer of colostral antigen-specific T-cell-specific responses in a newborn. In this study we examined the transfer of vaccine-inducedMycoplasma hyopneumoniaecellular immunity from immune dams to newborn piglets. Newborn piglets from vaccinated and nonvaccinated dams were assessed in two ways for cellular immune responses specific toM. hyopneumoniae: (i) delayed-type hypersensitivity (DTH) testing and (ii) in vitro lymphocyte proliferation, assayed on piglet blood lymphocytes and sow colostral lymphocytes. DTH responses toM. hyopneumoniaewere detected only for offspring of vaccinated sows, whereas DTH responses to the nonspecific mitogen phytohemagglutinin were seen for all piglets.M. hyopneumoniae-specific proliferation was seen for colostral lymphocytes from vaccinated sows and for blood lymphocytes from neonatal piglets of vaccinated dams but not for blood lymphocytes from piglets of nonvaccinated sows. Functional antigen-specific T cells were transferred to offspring from vaccinated sows and participated in the neonatal immune response upon stimulation. These data have implications for defining disease intervention strategies.
Nasopharyngeal
Haemophilus influenzae
Carriage in Japanese Children Attending Day-Care Centers
Authors: Hashida Koichi , Shiomori Teruo , Hohchi Nobusuke , Muratani Tetsuro , Mori Takanori , Udaka Tsuyoshi , Suzuki Hideaki
Published: January 2008

We conducted a prospective bacteriological survey to investigate antibiotic resistance-related genetic characteristics and the turnover of nasopharyngeal
Haemophilus influenzae
carriage in healthy children in day-care centers (DCCs). A total of 363 nasopharyngeal mucus samples were collected from children aged 0 to 6 years attending two DCCs in the summer of 2004 (
n
= 184) and the following winter (
n
= 179). We obtained 172
H. influenzae
isolates and analyzed them by antimicrobial susceptibility testing, PCR for
bla
TEM-1
and the penicillin-binding protein (PBP) gene, and pulsed-field gel electrophoresis (PFGE). The overall carriage rate was 47.4% (172/363), and 37.2% of the isolates (64/172) were ampicillin (AMP) resistant. All the resistant isolates had a PBP mutation(s), while only three isolates had TEM-1. The carriage rate was significantly higher in the winter than in the summer (56.4% and 38.6%, respectively), owing to the increase in the numbers of AMP-susceptible
H. influenzae
isolates in the winter. Children aged ≤3 years showed a higher rate of carriage of
H. influenzae
isolates with an AMP resistance gene(s) than those aged ≥4 years (21.9% and 12.6%, respectively). Forty-two strains with different PFGE patterns were obtained from among the 172 isolates. Only five strains were observed in both seasons. None of the strains isolated in the summer was isolated from the same carrier in the winter. Twenty-seven strains (64.3%) were isolated from two or more children, and 25 of these were each isolated from children belonging to the same DCC. These results indicate the spread of
H. influenzae
, particularly those with a PBP mutation(s), and the highly vigorous genetic turnover and substantial horizontal transmission of this pathogen in healthy children attending DCCs in Japan.
Dissemination of CTX-M-15 β-Lactamase Genes Carried on Inc FI and FII Plasmids among Clinical Isolates of
Escherichia coli
in a University Hospital in Istanbul, Turkey
Authors: Gonullu Nevriye , Aktas Zerrin , Kayacan Cigdem Bal , Salcioglu Melek , Carattoli Alessandra , Yong Dong Eun , Walsh Timothy R.
Published: January 2008

The CTX-M-1 group was found in 86.8% of the
Escherichia coli
isolates from Istanbul. A subset study revealed all isolates carrying
bla
CTX-M-15
genes flanked by the insertion element IS
Ecp1
. Plasmid typing of transconjugates carrying
bla
CTX-M-15
showed that most isolates belonged to the Inc/rep FII group but that one isolate also belonged to the FI group.
Differential Requirements for T Cells in Viruslike Particle- and Rotavirus-Induced Protective Immunity
Authors: Blutt Sarah E. , Warfield Kelly L. , Estes Mary K. , Conner Margaret E.
Published: January 2008

Correlates of protection from rotavirus infection are controversial. We compared the roles of B and T lymphocytes in protective immunity induced either by intranasally administered nonreplicating viruslike particles or inactivated virus or by orally administered murine rotavirus. We found that protection induced by nonreplicating vaccines requires CD4+T cells and CD40/CD40L. In contrast, T cells were not required for short-term protective immunity induced by infection, but both T-cell-dependent and -independent mechanisms contributed to long-term maintenance of protection. Our findings indicate that more than one marker of protective immunity exists and that these markers depend on the vaccine that is administered.
Egress of Light Particles among Filopodia on the Surface of Varicella-Zoster Virus-Infected Cells
Authors: Carpenter John E. , Hutchinson Jennifer A. , Jackson Wallen , Grose Charles
Published: January 2008

Varicella-zoster virus (VZV) is renowned for its very low titer when grown in cultured cells. There remains no single explanation for the low infectivity. In this study, viral particles on the surfaces of infected cells were examined by several imaging technologies. Few surface particles were detected at 48 h postinfection (hpi), but numerous particles were observed at 72 and 96 hpi. At 72 hpi, 75% of the particles resembled light (L) particles, i.e., envelopes without capsids. By 96 hpi, 85% of all particles resembled L particles. Subsequently, the envelopes of complete virions and L particles were investigated to determine their glycoprotein constituents. Glycoproteins gE, gI, and gB were detected in the envelopes of both types of particles in similar numbers; i.e., there appeared to be no difference in the glycoprotein content of the L particles. The viral particles emerged onto the cell surface amid actin-based filopodia, which were present in abundance within viral highways. Viral particles were easily detected at the base of and along the exterior surfaces of the filopodia. VZV particles were not detected within filopodia. In short, these results demonstrate that VZV infection of cultured cells produces a larger proportion of aberrant coreless particles than has been seen with any other previously examined alphaherpesvirus. Further, these results suggested a major disassociation between capsid formation and envelopment as an explanation for the invariably low VZV titer in cultured cells.
Envelope Protein Palmitoylations Are Crucial for Murine Coronavirus Assembly
Authors: Boscarino Joseph A. , Logan Hillary L. , Lacny Jason J. , Gallagher Thomas M.
Published: January 2008

The coronavirus assembly process encloses a ribonucleoprotein genome into vesicles containing the lipid-embedded proteins S (spike), E (envelope), and M (membrane). This process depends on interactions with membranes that may involve palmitoylation, a common posttranslational lipidation of cysteine residues. To determine whether specific palmitoylations influence coronavirus assembly, we introduced plasmid DNAs encoding mouse hepatitis coronavirus (MHV) S, E, M, and N (nucleocapsid) into 293T cells and found that virus-like particles (VLPs) were robustly assembled and secreted into culture medium. Palmitate adducts predicted on cysteines 40, 44, and 47 of the 83-residue E protein were then evaluated by constructing mutant cDNAs with alanine or glycine codon substitutions at one or more of these positions. Triple-substituted proteins (E.Ts) lacked palmitate adducts. Both native E and E.T proteins localized at identical perinuclear locations, and both copurified with M proteins, but E.T was entirely incompetent for VLP production. In the presence of the E.T proteins, the M protein subunits accumulated into detergent-insoluble complexes that failed to secrete from cells, while native E proteins mobilized M into detergent-soluble secreted forms. Many of these observations were corroborated in the context of natural MHV infections, with native E, but not E.T, complementing debilitated recombinant MHVs lacking E. Our findings suggest that palmitoylations are essential for E to act as a vesicle morphogenetic protein and further argue that palmitoylated E proteins operate by allowing the primary coronavirus assembly subunits to assume configurations that can mobilize into secreted lipid vesicles and virions.
Importance of Conserved Cysteine Residues in the Coronavirus Envelope Protein
Authors: Lopez Lisa A. , Riffle Ambere J. , Pike Steven L. , Gardner Douglas , Hogue Brenda G.
Published: January 2008

Coronavirus envelope (E) proteins play an important, not fully understood role(s) in the virus life cycle. All E proteins have conserved cysteine residues located on the carboxy side of the long hydrophobic domain, suggesting functional significance. In this study, we confirmed that mouse hepatitis coronavirus A59 E protein is palmitoylated. To understand the role of the conserved residues and the necessity of palmitoylation, three cysteines at positions 40, 44, and 47 were changed singly and in various combinations to alanine. Double- and triple-mutant E proteins resulted in decreased virus-like particle output when coexpressed with the membrane (M) protein. Mutant E proteins were also studied in the context of a full-length infectious clone. Single-substitution viruses exhibited growth characteristics virtually identical to those of the wild-type virus, while the double-substitution mutations gave rise to viruses with less robust growth phenotypes indicated by smaller plaques and decreased virus yields. In contrast, replacement of all three cysteines resulted in crippled virus with significantly reduced yields. Triple-mutant viruses did not exhibit impairment in entry. Mutant E proteins localized properly in infected cells. A comparison of intracellular and extracellular virus yields suggested that release is only slightly impaired. E protein lacking all three cysteines exhibited an increased rate of degradation compared to that of the wild-type protein, suggesting that palmitoylation is important for the stability of the protein. Altogether, the results indicate that the conserved cysteines and presumably palmitoylation are functionally important for virus production.
Differential CD4+versus CD8+T-Cell Responses Elicited by Different Poxvirus-Based Human Immunodeficiency Virus Type 1 Vaccine Candidates Provide Comparable Efficacies in Primates
Authors: Mooij Petra , Balla-Jhagjhoorsingh Sunita S. , Koopman Gerrit , Beenhakker Niels , van Haaften Patricia , Baak Ilona , Nieuwenhuis Ivonne G. , Kondova Ivanela , Wagner Ralf , Wolf Hans , Gómez Carmen E. , Nájera José L. , Jiménez Victoria , Esteban Mariano , Heeney Jonathan L.
Published: January 2008

Poxvirus vectors have proven to be highly effective for boosting immune responses in diverse vaccine settings. Recent reports reveal marked differences in the gene expression of human dendritic cells infected with two leading poxvirus-based human immunodeficiency virus (HIV) vaccine candidates, New York vaccinia virus (NYVAC) and modified vaccinia virus Ankara (MVA). To understand how complex genomic changes in these two vaccine vectors translate into antigen-specific systemic immune responses, we undertook a head-to-head vaccine immunogenicity and efficacy study in the pathogenic HIV type 1 (HIV-1) model of AIDS in Indian rhesus macaques. Differences in the immune responses in outbred animals were not distinguished by enzyme-linked immunospot assays, but differences were distinguished by multiparameter fluorescence-activated cell sorter analysis, revealing a difference between the number of animals with both CD4+and CD8+T-cell responses to vaccine inserts (MVA) and those that elicit a dominant CD4+T-cell response (NYVAC). Remarkably, vector-induced differences in CD4+/CD8+T-cell immune responses persisted for more than a year after challenge and even accompanied antigenic modulation throughout the control of chronic infection. Importantly, strong preexposure HIV-1/simian immunodeficiency virus-specific CD4+T-cell responses did not prove deleterious with respect to accelerated disease progression. In contrast, in this setting, animals with strong vaccine-induced polyfunctional CD4+T-cell responses showed efficacies similar to those with stronger CD8+T-cell responses.
Clonogenic Assay of Type A Influenza Viruses Reveals Noninfectious Cell-Killing (Apoptosis-Inducing) Particles
Authors: Ngunjiri John M. , Sekellick Margaret J. , Marcus Philip I.
Published: January 2008

Clonogenic (single-cell plating) assays were used to define and quantify subpopulations of two genetically closely related variants of influenza virus A/TK/OR/71 that differed primarily in the size of the NS1 gene product; they expressed a full-size (amino acids [aa] 1 to 230) or truncated (aa 1 to 124) NS1 protein. Monolayers of Vero cells were infected with different amounts of virus, monodispersed, and plated. Cell survival curves were generated from the fraction of cells that produced visible colonies as a function of virus multiplicity. The exponential loss of colony-forming capacity at low multiplicities demonstrated that a single virus particle sufficed to kill a cell. The ratios of cell-killing particles (CKP) to plaque-forming particles (PFP) were 1:1 and 7:1 in populations of variants NS1
1-124
and NS1
1-230
, respectively. This study revealed a new class of particles in influenza virus populations—noninfectious CKP. Both infectious and noninfectious CKP were 6.3 times more resistant to UV radiation than PFP activity. Based on UV target theory, a functional polymerase subunit was implicated in a rate-limiting step in cell killing. Since influenza viruses kill cells by apoptosis (programmed cell death), CKP are functionally apoptosis-inducing particles. Noninfectious CKP are present in excess of PFP in virus populations with full-size NS1 and induce apoptosis that is temporally delayed and morphologically different than that initiated by infectious CKP present in the virus population expressing truncated NS1. The identification and quantification of both infectious and noninfectious CKP defines new phenotypes in influenza virus populations and presents a challenge to determine their role in regulating infectivity, pathogenesis, and vaccine efficacy.
Increased Cytotoxic T-Lymphocyte Epitope Variant Cross-Recognition and Functional Avidity Are Associated with Hepatitis C Virus Clearance
Authors: Yerly Daniel , Heckerman David , Allen Todd M. , Chisholm John V. , Faircloth Kellie , Linde Caitlyn H. , Frahm Nicole , Timm Joerg , Pichler Werner J. , Cerny Andreas , Brander Christian
Published: January 2008

Hepatitis C virus (HCV) clearance has been associated with reduced viral evolution in targeted cytotoxic T-lymphocyte (CTL) epitopes, suggesting that HCV clearers may mount CTL responses with a superior ability to recognize epitope variants and prevent viral immune escape. Here, 40 HCV-infected subjects were tested with 406 10-mer peptides covering the vast majority of the sequence diversity spanning a 197-residue region of the NS3 protein. HCV clearers mounted significantly broader CTL responses of higher functional avidity and with wider variant cross-recognition capacity than nonclearers. These observations have important implications for vaccine approaches that may need to induce high-avidity responses in vivo.
Control of mRNA Export by Adenovirus E4orf6 and E1B55K Proteins during Productive Infection Requires E4orf6 Ubiquitin Ligase Activity
Authors: Blanchette Paola , Kindsmüller Kathrin , Groitl Peter , Dallaire Frédéric , Speiseder Thomas , Branton Philip E. , Dobner Thomas
Published: January 2008

During the adenovirus infectious cycle, the early proteins E4orf6 and E1B55K are known to perform several functions. These include nuclear export of late viral mRNAs, a block of nuclear export of the bulk of cellular mRNAs, and the ubiquitin-mediated degradation of selected proteins, including p53 and Mre11. Degradation of these proteins occurs via a cellular E3 ubiquitin ligase complex that is assembled through interactions between elongins B and C and BC boxes present in E4orf6 to form a cullin 5-based ligase complex. E1B55K, which has been known for some time to associate with the E4orf6 protein, is thought to bind to specific substrate proteins to bring them to the complex for ubiquitination. Earlier studies with E4orf6 mutants indicated that the interaction between the E4orf6 and E1B55K proteins is optimal only when E4orf6 is able to form the ligase complex. These and other observations suggested that most if not all of the functions ascribed to E4orf6 and E1B55K during infection, including the control of mRNA export, are achieved through the degradation of specific substrates by the E4orf6 ubiquitin ligase activity. We have tested this hypothesis through the generation of a virus mutant in which the E4orf6 product is unable to form a ligase complex and indeed have found that this mutant behaves identically to an E4orf6
−
virus in production of late viral proteins, growth, and export of the late viral L5 mRNA.
Phagocytosis of Picornavirus-Infected Cells Induces an RNA-Dependent Antiviral State in Human Dendritic Cells
Authors: Kramer Matthijs , Schulte Barbara M. , Toonen Liza W. J. , Barral Paola M. , Fisher Paul B. , Lanke Kjerstin H. W. , Galama Jochem M. D. , van Kuppeveld Frank J. M. , Adema Gosse J.
Published: January 2008

Dendritic cells (DCs) play a central role in instructing antiviral immune responses. DCs, however, can become targeted by different viruses themselves. We recently demonstrated that human DCs can be productively infected with echoviruses (EVs), but not coxsackie B viruses (CVBs), both of which are RNA viruses belonging to the
Enterovirus
genus of the
Picornaviridae
family. We now show that phagocytosis of CVB-infected, type I interferon-deficient cells induces an antiviral state in human DCs. Uptake of infected cells increased the expression of the cytoplasmic RNA helicases retinoic acid-inducible gene I and melanoma differentiation-associated gene 5 as well as other interferon-stimulated genes and protected DCs against subsequent infection with EV9. These effects depended on recognition of viral RNA and could be mimicked by exposure to the synthetic double-stranded RNA analogue poly(I:C) but not other Toll-like receptor (TLR) ligands. Blocking endosomal acidification abrogated protection, suggesting a role for TLRs in the acquisition of an antiviral state in DCs. In conclusion, recognition of viral RNA rapidly induces an antiviral state in human DCs. This might provide a mechanism by which DCs protect themselves against viruses when attracted to an environment with ongoing infection.
Crystal Structure of Unliganded Influenza B Virus Hemagglutinin
Authors: Wang Qinghua , Cheng Feng , Lu Mingyang , Tian Xia , Ma Jianpeng
Published: January 2008

Here we report the crystal structure of hemagglutinin (HA) from influenza B/Hong Kong/8/73 (B/HK) virus determined to 2.8 Å. At a sequence identity of ∼25% to influenza A virus HAs, B/HK HA shares a similar overall structure and domain organization. More than two dozen amino acid substitutions on influenza B virus HAs have been identified to cause antigenicity alteration in site-specific mutants, monoclonal antibody escape mutants, or field isolates. Mapping these substitutions on the structure of B/HK HA reveals four major epitopes, the 120 loop, the 150 loop, the 160 loop, and the 190 helix, that are located close in space to form a large, continuous antigenic site. Moreover, a systematic comparison of known HA structures across the entire influenza virus family reveals evolutionarily conserved ionizable residues at all regions along the chain and subunit interfaces. These ionizable residues are likely the structural basis for the pH dependence and sensitivity to ionic strength of influenza HA and hemagglutinin-esterase fusion proteins.
Antiviral CD8 T Cells Recognize Borna Disease Virus Antigen Transgenically Expressed in either Neurons or Astrocytes
Authors: Baur Karen , Rauer Mathias , Richter Kirsten , Pagenstecher Axel , Götz Jürgen , Hausmann Jürgen , Staeheli Peter
Published: January 2008

Borna disease virus (BDV) can persistently infect the central nervous system (CNS) of mice. The infection remains nonsymptomatic as long as antiviral CD8 T cells do not infiltrate the infected brain. BDV mainly infects neurons which reportedly carry few, if any, major histocompatibility complex class I molecules on the surface. Therefore, it remains unclear whether T cells can recognize replicating virus in these cells or whether cross-presentation of viral antigen by other cell types is important for immune recognition of BDV. To distinguish between these possibilities, we used two lines of transgenic mice that strongly express the N protein of BDV in either neurons (Neuro-N) or astrocytes (Astro-N). Since these animals are tolerant to the neo-self-antigen, we adoptively transferred T cells with specificity for BDV N. In nontransgenic mice persistently infected with BDV, the transferred cells accumulated in the brain parenchyma along with immune cells of host origin and efficiently induced neurological disease. Neurological disease was also observed if antiviral T cells were injected into the brains of Astro-N or Neuro-N but not nontransgenic control mice. Our results demonstrate that CD8 T cells can recognize foreign antigen on neurons and astrocytes even in the absence of infection or inflammation, indicating that these CNS cell types are playing an active role in immune recognition of viruses.
NRF-1genotypes and endurance exercise capacity in young Chinese men
Authors: He Z , Hu Y , Feng L , Li Y , Liu G , Xi Y , Wen L , Lucia A
Published: January 2008

Background:

Nuclear respiratory factor 1 (NRF-1) is a critical component of the energy-sensing mechanism in mammalian cells, and translates physiological signals (particularly those induced by exercise) into increased capacity for mitochondrial biogenesis and oxidative phosphorylation.

Objective:

To study the possible association between rs2402970, rs6949152 and rs10500120NRF-1genotypes and several phenotypes indicative of maximum (VO2max) and submaximum aerobic capacity (ventilatory threshold (VT) and metabolic cost of submaximum running at 12 km/hour (running economy; RE)) both at baseline and in response to a 18-week endurance training programme in young Chinese men of Han origin (n = 102; 19 (SD 1) years).

Results:

For rs2402970, a significant genotype effect was seen for VT (p = 0.004) and RE (p = 0.027). For rs6949152, a significant interaction (genotype×training) effect (p = 0.047) was found for VT.

Conclusions:

There is an association betweenNRF-1genotypes (rs2402970 and rs6949152 polymorphisms) and the baseline and/or training response of human aerobic capacity. More research is needed to corroborate our data in other ethnic groups with lower fitness levels at the pre-training state (particularly Caucasians) and to identify the molecular mechanisms involved in the genotype–phenotype associations we found.
A FAST METHOD FOR IMPLICIT SURFACE RECONSTRUCTION BASED ON RADIAL BASIS FUNCTIONS NETWORK FROM 3D SCATTERED POINTS
Authors: LIU HANBO , WANG XIN , QIANG WENYI
Published: January 2008

A method for arbitrary surface reconstruction from 3D large scattered points is proposed in this paper. According to the properties of 3D points, e.g. the non-uniform distribution and unknown topology, an implicit surface model is adopted based on radial basis functions network. And because of the property of locality of radial basis function, the method is fast and robust in surface reconstruction. Furthermore, an adapted K-Means algorithm is used to reduce reconstruction centers. For features completeness, two effective methods are introduced to extract the feature points before the adapted K-Means algorithm. Experiment results show that the presented approach is a good solution for reconstruction from 3D large scattered points.
SVM-BASED LEARNING CONTROL OF SPACE ROBOTS IN CAPTURING OPERATION
Authors: HUANG PANFENG , XU YANGSHENG
Published: January 2008

In this paper, we presents a novel approach for tracking and catching operation of space robots using learning and transferring human control strategies (HCS). We firstly use an efficient support vector machine (SVM) to parametrize the model of HCS. Then we develop a new SVM-based learning structure to better implement human control strategy learning in tracking and capturing control. The approach is fundamentally valuable in dealing with some problems such as small sample data and local minima, and so on. Therefore this approach is efficient in modeling, understanding and transferring its learning process. The simulation results attest that this approach is useful and feasible in generating tracking trajectory and catching objects autonomously.
MULTI-VIEW GENDER CLASSIFICATION USING MULTI-RESOLUTION LOCAL BINARY PATTERNS AND SUPPORT VECTOR MACHINES
Authors: LIAN HUI-CHENG , LU BAO-LIANG
Published: January 2008

In this paper, we present a novel method for multi-view gender classification considering both shape and texture information to represent facial images. The face area is divided into small regions from which local binary pattern (LBP) histograms are extracted and concatenated into a single vector efficiently representing a facial image. Following the idea of local binary pattern, we propose a new feature extraction approach called multi-resolution LBP, which can retain both fine and coarse local micro-patterns and spatial information of facial images. The classification tasks in this work are performed by support vector machines (SVMs). The experiments clearly show the superiority of the proposed method over both support gray faces and support Gabor faces on the CAS-PEAL face database. A higher correct classification rate of 96.56% and a higher cross validation average accuracy of 95.78% have been obtained. In addition, the simplicity of the proposed method leads to very fast feature extraction, and the regional histograms and fine-to-coarse description of facial images allow for multi-view gender classification.
MULTISENSOR REMOTE SENSING IMAGE FUSION USING STATIONARY WAVELET TRANSFORM: EFFECTS OF BASIS AND DECOMPOSITION LEVEL
Authors: LI SHUTAO
Published: January 2008

Stationary wavelet transform is an efficient algorithm for remote sensing image fusion. In this paper, we investigate the effects of orthogonal/biorthogonal filters and decomposition depth on using stationary wavelet analysis for fusion. Spectral discrepancy and spatial distortion are used as quality measures. Empirical results lead to some recommendations on the wavelet filter parameters for use in remote sensing image fusion applications.
AN OPTIMIZATION ALGORITHM FOR BIORTHOGONAL WAVELET FILTER BANKS DESIGN
Authors: YANG GUOAN , ZHENG NANNING
Published: January 2008

A new approach for designing the Biorthogonal Wavelet Filter Bank (BWFB) for the purpose of image compression is presented in this paper. The approach is broken into two steps. First, an optimal filter bank is designed in the theoretical sense, based on Vaidyanathan's coding gain criterion in the SubBand Coding (SBC) system. Then, the above filter bank is optimized based on the criterion of Peak Signal-to-Noise Ratio (PSNR) in the JPEG2000 image compression system, resulting in a BWFB in practical application sense. With the approach, a series of BWFBs for a specific class of applications related to image compression, such as gray-level images, can be quickly designed. Here, new 7/5 BWFBs are presented based on the above approach for image compression applications. Experiments show that the 7/5 BWFBs not only have excellent compression performance, but also easy computation and are more suitable for VLSI hardware implementations. They perform equally well with respect to 7/5 filters in the JPEG2000 standard.