bluuebunny/crossref_metadata_2025 huggingface dataset:
Persistence of Livestock-Associated Methicillin-Resistant Staphylococcus aureus in Field Workers after Short-Term Occupational Exposure to Pigs and Veal Calves
Authors: van Cleef Brigitte A. G. L. , Graveland Haitske , Haenen Anja P. J. , van de Giessen Arjen W. , Heederik Dick , Wagenaar Jaap A. , Kluytmans Jan A. J. W.
Published: January 2011

The prevalence of methicillin-resistant
Staphylococcus aureus
(MRSA) carriage in pig and veal calf farmers in the Netherlands is estimated at 25 to 35%. However, no information is available about MRSA carriage in humans after short-term occupational exposure to pigs or veal calves. This study examines the prevalence and duration of MRSA acquisition after short-term intensive exposure to pigs or veal calves for persons not exposed to livestock on a daily basis. The study was performed with field workers who took samples from the animals or the animal houses in studies on MRSA prevalence in pig and veal farms. They were tested for MRSA by taking nasal samples before, directly after, and 24 h after they visited the farms. There were 199 sampling moments from visits to 118 MRSA-positive farms. Thirty-four of these visits (17%) resulted in the acquisition of MRSA. Thirty-one persons (94%) appeared negative again after 24 h. There were 62 visits to 34 MRSA-negative farms; none of the field workers acquired MRSA during these visits. Except for that from one person, all
spa
types found in the field workers were identical to those found in the animals or in the dust in animal houses and belonged to the livestock-associated clone. In conclusion, MRSA is frequently present after short-term occupational exposure, but in most cases the strain is lost again after 24 h.
Cellulosimicrobium funkei: First Report of Infection in a Nonimmunocompromised Patient and Useful Phenotypic Tests for Differentiation from Cellulosimicrobium cellulans and Cellulosimicrobium terreum
Authors: Petkar Hawabibee , Li Anthony , Bunce Nicholas , Duffy Kim , Malnick Henry , Shah Jayesh J.
Published: January 2011

Cellulosimicrobium funkei
is a rare, opportunistic pathogen. We describe a case of bacteremia and possibly prosthetic valve endocarditis by this organism in a nonimmunocompromised patient. Useful phenotypic tests for differentiating
C. funkei
from
Cellulosimicrobium cellulans
and
Cellulosimicrobium terreum
include motility, raffinose fermentation, glycogen,
d
-xylose, and methyl-α-
d
-glucopyranoside assimilation, and growth at 35°C.
Interpretation of Real-Time PCR Results for Hepatitis C Virus RNA When Viral Load Is Below Quantification Limits
Authors: Laperche Syria , Bouchardeau Françoise , André-Garnier Elisabeth , Thibault Vincent , Roque-Afonso Anne-Marie , Trimoulet Pascale , Colimon Ronald , Duverlie Gilles , Leguillou-Guillemette Hélène , Lunel Françoise , Bouvier-Alias Magali , Pawlotsky Jean-Michel , Henquell Cécile , Schvoerer Evelyne , Stoll-Keller Françoise , Chaix Marie-Laure , Branger Michel , Gaudy-Graffin Catherine , Rosenberg Arielle R. , Pozzetto Bruno , Vallet Sophie , Baazia Yazid , Izopet Jacques , Lefrère Jean-Jacques
Published: January 2011

Hepatitis C virus RNA quantification results obtained in 18 laboratories using real-time PCR methods with 10 negative samples and 22 sample dilutions (viral loads of 0.5 to 500 IU/ml) showed a score of correct results of up to 93.5%. However, 55.6% of the laboratories did not follow the recommendations for the interpretation of their results, leading to ambiguous conclusions.
Human and Swine Hosts Share Vancomycin-Resistant Enterococcus faecium CC17 and CC5 and Enterococcus faecalis CC2 Clonal Clusters Harboring Tn
1546
on Indistinguishable Plasmids
Authors: Freitas Ana R. , Coque Teresa M. , Novais Carla , Hammerum Anette M. , Lester Camilla H. , Zervos Marcus J. , Donabedian Susan , Jensen Lars B. , Francia Maria Victoria , Baquero Fernando , Peixe Luísa
Published: January 2011

VRE isolates from pigs (
n
= 29) and healthy persons (
n
= 12) recovered during wide surveillance studies performed in Portugal, Denmark, Spain, Switzerland, and the United States (1995 to 2008) were compared with outbreak/prevalent VRE clinical strains (
n
= 190; 23 countries; 1986 to 2009). Thirty clonally related
Enterococcus faecium
clonal complex 5 (CC5) isolates (17 sequence type 6 [ST6], 6 ST5, 5 ST185, 1 ST147, and 1 ST493) were obtained from feces of swine and healthy humans. This collection included isolates widespread among pigs of European Union (EU) countries since the mid-1990s. Each ST comprised isolates showing similar pulsed-field gel electrophoresis (PFGE) patterns (≤6 bands difference; >82% similarity). Some CC5 PFGE subtype strains from swine were indistinguishable from hospital vancomycin-resistant enterococci (VRE) causing infections. A truncated variant of Tn
1546
(encoding resistance to vancomycin) and
tcrB
(coding for resistance to copper) were consistently located on 150- to 190-kb plasmids (rep
pLG1
).
E. faecium
CC17 (ST132) isolates from pig manure and two clinical samples showed identical PFGE profiles and contained a 60-kb mosaic plasmid (rep
Inc18
plus rep
pRUM
) carrying diverse Tn
1546
-IS
1216
variants. The only
Enterococcus faecalis
isolate obtained from pigs (CC2-ST6) corresponded to a multidrug-resistant clone widely disseminated in hospitals in Italy, Portugal, and Spain, and both animal and human isolates harbored an indistinguishable 100-kb mosaic plasmid (rep
pRE25
plus rep
pCF10
) containing the whole Tn
1546
backbone. The results indicate a current intra- and international spread of
E. faecium
and
E. faecalis
clones and their plasmids among swine and humans.
Emergence in Spain of a Multidrug-Resistant Enterobacter cloacae Clinical Isolate Producing SFO-1 Extended-Spectrum β-Lactamase
Authors: Fernández Ana , Pereira María José , Suárez José Manuel , Poza Margarita , Treviño Mercedes , Villalón Pilar , Sáez-Nieto Juan Antonio , Regueiro Benito José , Villanueva Rosa , Bou Germán
Published: January 2011

Between February 2006 and October 2009, 38 patients in different wards at the A Coruña University Hospital (northwest Spain) were either infected with or colonized by an epidemic, multidrug-resistant (MDR), and extended-spectrum-β-lactamase (ESBL)-producing strain of
Enterobacter cloacae
(EbSF), which was susceptible only to carbapenems. Semiautomated repetitive extragenic palindromic sequence-based PCR (rep-PCR) and pulsed-field gel electrophoresis (PFGE) analysis revealed that all of the
E. cloacae
isolates belonged to the same clone. Cloning and sequencing enabled the detection of the SFO-1 ESBL in the epidemic strain and the description of its genetic environment. The presence of the
ampR
gene was detected upstream of
bla
SFO-1
, and two complete sequences of IS
26
surrounding
ampR
and
ampA
were detected. These IS
26
sequences are bordered by complete left and right inverted repeats (IRL and IRR, respectively), which suggested that they were functional. The whole segment flanked by two IS
26
copies may be considered a putative large composite transposon. A gene coding for aminoglycoside acetyltransferase (gentamicin resistance gene [
aac3
]) was found downstream of the 3′ IS
26
. Despite the implementation of strict infection control measures, strain EbSF spread through different areas of the hospital. A case-control study was performed to assess risk factors for EbSF acquisition. A multivariate analysis revealed that the prior administration of β-lactam antibiotics, chronic renal failure, tracheostomy, and prior hospitalization were statistically associated with SFO-1-producing
E. cloacae
acquisition. This study describes for the first time an outbreak in which an SFO-1-producing
E. cloacae
strain was involved. Note that so far, this β-lactamase has previously been isolated in only a single case of
E. cloacae
infection in Japan.
Ribosomal and Mitochondrial DNA Target for Real-Time PCR Diagnosis of Invasive Aspergillosis
Authors: Millon L. , Grenouillet F. , Legrand F. , Loewert S. , Bellanger A. P. , Gbaguidi-Haore H. , Scherer E. , Henon T. , Rohrlich P. , Deconinck E.
Published: January 2011

The aim of the present study was to assess the diagnostic efficacy of a combination of two quantitative
Aspergillus
PCR assays, targeting a mitochondrial and a ribosomal target, in patients with risk factors for invasive aspergillosis (IA) and positive galactomannan (GM) antigen. Forty-four patients with hematological malignancies and risk factors for IA according to revised European Organization for Research on Treatment of Cancer and the Mycoses Study Group criteria (EORTC/MSG) criteria and presenting at least two sequential GM-positive sera were included in the study. Mitochondrial PCR was carried out prospectively on all GM-positive serum samples. Ribosomal PCR was carried out retrospectively on frozen stored sera. The sensitivities of mitochondrial and ribosomal PCRs were 58% and 50%, respectively. The diagnostic test performance was improved by using a combination of both PCR assays and by considering a patient PCR positive when at least two positive results were obtained. The sensitivity, specificity, and positive and negative likelihood ratios were 65%, 94%, and 11.8 and 0.37, respectively. A significant association between fatal outcome at 90 days and positive results of ribosomal PCR assays was observed (adjusted hazard ratio = 8.2; 95% confidence interval [CI] = 1.0 to 65.8;
P
= 0.048). Our results showed that the combination of two PCR assays targeting mitochondrial and ribosomal
Aspergillus
DNA improves the sensitivity of PCR in the diagnosis of IA in hematological patients with risk factors and positive GM results. This study also confirms that a positive PCR result is associated with a poor prognosis in these patients and should lead to specific antifungal therapy being introduced immediately.
Optimizing a Candida Biofilm Microtiter Plate Model for Measurement of Antifungal Susceptibility by Tetrazolium Salt Assay
Authors: Nett Jeniel E. , Cain Michael T. , Crawford Kyler , Andes David R.
Published: January 2011

Candida
spp. infect medical devices, such as venous and urinary catheters, by adhering to the surface and forming a community of drug-resistant cells surrounded by a matrix. The ability to measure drug activity during this biofilm mode of growth is of interest for the investigation of resistance mechanisms and novel antifungal therapies. The tetrazolium salt (XTT) reduction assay is the test most commonly used to estimate viable biofilm growth and to examine the impact of biofilm therapies. The primary goal of the current experiments was to identify assay variables that affect the XTT assay result in order to improve assay reproducibility, sensitivity, and throughput for the study of antifungal activity. The species used in the current studies included
Candida albicans
,
C. parapsilosis
, and
C. glabrata
. The assay variables that were studied included the impact of culture conditions, the duration of biofilm growth, the timing and frequency of drug administration, the XTT source and concentration, and the duration of XTT incubation. The conditions that impacted the assay readout and altered assay sensitivity included the duration of biofilm growth, the frequency of drug dosing, and the duration of XTT incubation. Several factors were found to reduce time and assay expense, including the elimination of washing steps, the shortening of incubation times, and the use of lower XTT concentrations. A description of assay pitfalls and troubleshooting is included. Recognition of these technical variables should allow investigators to better design reproducible biofilm therapeutic studies.
Herpes Simplex Virus Requires VP11/12 To Activate Src Family Kinase-Phosphoinositide 3-Kinase-Akt Signaling
Authors: Wagner Melany J. , Smiley James R.
Published: January 2011

We previously showed that the herpes simplex virus 1 (HSV-1) tegument protein VP11/12 activates the lymphocyte-specific Src family kinase (SFK) Lck and is tyrosine phosphorylated in an Lck-dependent manner during T cell infection. We now extend these findings to show that ectopic expression of Lck induces robust tyrosine phosphorylation of VP11/12 in Vero cells, strongly suggesting that VP11/12 participates in an Lck-mediated signaling pathway as a substrate of Lck or a kinase activated by Lck. We sought to elucidate signaling events downstream of VP11/12-SFK interactions. SFKs lie upstream of the canonical phosphoinositide 3-kinase (PI3K)-Akt pathway in signaling emanating from immune receptors, growth factor receptors, and polyomavirus middle T antigen. Here, we show that VP11/12 is required for virus-induced activation of PI3K-Akt signaling in HSV-infected Jurkat T cells and primary fibroblasts. VP11/12 interacts with PI3K or PI3K signaling complexes during infection, suggesting that VP11/12 activates PI3K directly. SFK activity is required for tyrosine phosphorylation of VP11/12, VP11/12-PI3K interactions, and Akt activation in infected fibroblasts, suggesting that SFK-dependent phosphorylation of VP11/12 is required for interactions with downstream signaling effectors. Akt controls many biological functions, including cell survival, cell motility, and translation, but it is currently unclear which Akt targets are modulated by VP11/12 during infection. Although the Akt target mTORC1 is activated during HSV-1 infection, VP11/12 is not required for this effect, implying that one or more additional viral proteins regulate this pathway. Further studies are therefore required to determine which Akt targets and associated biological functions are uniquely modulated by VP11/12.
Successful Propagation of Flavivirus Infectious cDNAs by a Novel Method To Reduce the Cryptic Bacterial Promoter Activity of Virus Genomes
Authors: Pu Szu-Yuan , Wu Ren-Huang , Yang Chi-Chen , Jao Tzu-Ming , Tsai Ming-Han , Wang Jing-Chyi , Lin Hui-Mei , Chao Yu-Sheng , Yueh Andrew
Published: January 2011

Reverse genetics is a powerful tool to study single-stranded RNA viruses. Despite tremendous efforts having been made to improve the methodology for constructing flavivirus cDNAs, the cause of toxicity of flavivirus cDNAs in bacteria remains unknown. Here we performed mutational analysis studies to identify
Escherichia coli
promoter (ECP) sequences within nucleotides (nt) 1 to 3000 of the dengue virus type 2 (DENV2) and Japanese encephalitis virus (JEV) genomes. Eight and four active ECPs were demonstrated within nt 1 to 3000 of the DENV2 and JEV genomes, respectively, using fusion constructs containing DENV2 or JEV segments and empty vector reporter gene
Renilla
luciferase. Full-length DENV2 and JEV cDNAs were obtained by inserting mutations reducing their ECP activity in bacteria without altering amino acid sequences. A severe cytopathic effect occurred when BHK21 cells were transfected with
in vitro
-transcribed RNAs from either a DENV2 cDNA clone with multiple silent mutations within the prM-E-NS1 region of dengue genome or a JEV cDNA clone with an A-to-C mutation at nt 90 of the JEV genome. The virions derived from the DENV2 or JEV cDNA clone exhibited infectivities similar to those of their parental viruses in C6/36 and BHK21 cells. A
cis
-acting element essential for virus replication was revealed by introducing silent mutations into the central portion (nt 160 to 243) of the core gene of DENV2 infectious cDNA or a subgenomic DENV2 replicon clone. This novel strategy of constructing DENV2 and JEV infectious clones could be applied to other flaviviruses or pathogenic RNA viruses to facilitate research in virology, viral pathogenesis, and vaccine development.
Theiler's Virus L* Protein Is Targeted to the Mitochondrial Outer Membrane
Authors: Sorgeloos Frédéric , Vertommen Didier , Rider Mark H. , Michiels Thomas
Published: January 2011

The L* protein encoded by Theiler's murine encephalomyelitis virus (TMEV) is a unique example of a picornaviral protein encoded by an alternative open reading frame. This protein is an important determinant of TMEV persistence in the mouse central nervous system. We showed that in infected cells, L* is partitioned between the cytosol and the mitochondria. In mitochondria, L* is anchored in the outer membrane and exposed to the cytosol. The targeting of L* to mitochondria is independent of other viral components and likely depends on a conformational signal. L* targeting to mitochondria might involve chaperones of the Hsp70 family, as these proteins are shown to interact.
Polyomavirus Middle T-Antigen Is a Transmembrane Protein That Binds Signaling Proteins in Discrete Subcellular Membrane Sites
Authors: Zhou Alice Y. , Ichaso Natalia , Adamarek Adam , Zila Vojtech , Forstova Jitka , Dibb Nicholas J. , Dilworth Stephen M.
Published: January 2011

Murine polyomavirus middle T-antigen (MT) induces tumors by mimicking an activated growth factor receptor. An essential component of this action is a 22-amino-acid hydrophobic region close to the C terminus which locates MT to cell membranes. Here, we demonstrate that this sequence is a transmembrane domain (TMD) by showing that a hemagglutinin (HA) tag added to the MT C terminus is exposed on the outside of the cells, with the N terminus inside. To determine whether this MT TMD is inserted into the endoplasmic reticulum (ER) membrane, we added the ER retention signal KDEL to the MT C terminus (MTKDEL). This mutant protein locates only in the ER, demonstrating that MT does insert into membranes solely at this location. In addition, this ER-located MT failed to transform. Examination of the binding proteins associated with the MTKDEL protein demonstrated that it associates with PP2A and c-Src but fails to interact with ShcA, phosphatidylinositol 3-kinase (PI3K), and phospholipase C-γ1 (PLC-γ1), despite being tyrosine phosphorylated. Additional mutant and antibody studies show that MT binding to PP2A is probably required for MT to efficiently exit the ER and migrate to the plasma membrane though the TMD also plays a role in this relocation. Overall, these data, together with previous publications, illustrate that MT associates with signaling proteins at different sites in its maturation pathway. MT binds to PP2A in the cytoplasm, to c-Src at the endoplasmic reticulum, and to ShcA, PI3K, and PLC-γ1 at subsequent locations en route to the plasma membrane.
Vaccination against Seasonal Influenza A/H3N2 Virus Reduces the Induction of Heterosubtypic Immunity against Influenza A/H5N1 Virus Infection in Ferrets
Authors: Bodewes R. , Kreijtz J. H. C. M. , Geelhoed-Mieras M. M. , van Amerongen G. , Verburgh R. J. , van Trierum S. E. , Kuiken T. , Fouchier R. A. M. , Osterhaus A. D. M. E. , Rimmelzwaan G. F.
Published: January 2011

Infection with seasonal influenza viruses induces a certain extent of protective immunity against potentially pandemic viruses of novel subtypes, also known as heterosubtypic immunity. Here we demonstrate that infection with a recent influenza A/H3N2 virus strain induces robust protection in ferrets against infection with a highly pathogenic avian influenza virus of the H5N1 subtype. Prior H3N2 virus infection reduced H5N1 virus replication in the upper respiratory tract, as well as clinical signs, mortality, and histopathological changes associated with virus replication in the brain. This protective immunity correlated with the induction of T cells that cross-reacted with H5N1 viral antigen. We also demonstrated that prior vaccination against influenza A/H3N2 virus reduced the induction of heterosubtypic immunity otherwise induced by infection with the influenza A/H3N2 virus. The implications of these findings are discussed in the context of vaccination strategies and vaccine development aiming at the induction of immunity to pandemic influenza.
Participation of Vaccinia Virus L2 Protein in the Formation of Crescent Membranes and Immature Virions
Authors: Maruri-Avidal Liliana , Domi Arban , Weisberg Andrea S. , Moss Bernard
Published: January 2011

Morphogenesis of vaccinia virus begins with the appearance of crescent-shaped membrane precursors of immature virions in cytoplasmic factories. During the initial characterization of the product of the L2R reading frame, we discovered that it plays an important role in crescent formation. The L2 protein was expressed early in infection and was associated with the detergent-soluble membrane fraction of mature virions, consistent with two potential membrane-spanning domains. All chordopoxviruses have L2 homologs, suggesting an important function. Indeed, we were unable to isolate an infectious L2R deletion mutant. Consequently, we constructed an inducible mutant with a conditional lethal phenotype. When L2 expression was repressed, proteolytic processing of the major core proteins and the A17 protein, which is an essential component of the immature virion membrane, failed to occur, suggesting an early block in viral morphogenesis. At 8 h after infection in the presence of inducer, immature and mature virions were abundantly seen by electron microscopy. In contrast, those structures were rare in the absence of inducer and were replaced by large, dense aggregates of viroplasm. A minority of these aggregates had short spicule-coated membranes, which resembled the beginnings of crescent formation, at their periphery. These short membrane segments at the edge of the dense viroplasm increased in number at later times, and some immature virions were seen. Although the L2 protein was not detected under nonpermissive conditions, minute amounts could account for stunted and delayed viral membrane formation. These findings suggested that L2 is required for the formation or elongation of crescent membranes.
Contribution of smoking-related and alcohol-related deaths to the gender gap in mortality: evidence from 30 European countries: Table 1
Authors: McCartney Gerry , Mahmood Lamia , Leyland Alastair H , Batty G David , Hunt Kate
Published: January 2011

Background

Women now outlive men throughout the globe, a mortality advantage that is very established in developed European countries. Debate continues about the causes of the gender gap, although smoking is known to have been a major contributor to the difference in the past.

Objectives

To compare the magnitude of the gender gap in all-cause mortality in 30 European countries and assess the contribution of smoking-related and alcohol-related deaths.

Methods

Data on all-cause mortality, smoking-related mortality and alcohol-related mortality for 30 European countries were extracted from the World Health Organization Health for All database for the year closest to 2005. Rates were standardised by the direct method using the European population standard and were for all age groups. The proportion of the gender gap in all-cause mortality attributable to smoking-related and alcohol-related deaths was then calculated.

Results

There was considerable variation in the magnitude of the male ‘excess’ of all-cause mortality across Europe, ranging from 188 per 100 000 per year in Iceland to 942 per 100 000 per year in Ukraine. Smoking-related deaths accounted for around 40% to 60% of the gender gap, while alcohol-related mortality typically accounted for 20% to 30% of the gender gap in Eastern Europe and 10% to 20% elsewhere in Europe.

Conclusions

Smoking continues to be the most important cause of gender differences in mortality across Europe, but its importance as an explanation for this difference is often overshadowed by presumptions about other explanations. Changes in smoking patterns by gender suggest that the gender gap in mortality will diminish in the coming decades.
XCSc: A NOVEL APPROACH TO CLUSTERING WITH EXTENDED CLASSIFIER SYSTEM
Authors: SHI LIANG-DONG , SHI YING-HUAN , GAO YANG , SHANG LIN , YANG YU-BIN
Published: January 2011

In this paper, we propose a novel approach to clustering noisy and complex data sets based on the eXtend Classifier Systems (XCS). The proposed approach, termed XCSc, has three main processes: (a) a learning process to evolve the rule population, (b) a rule compacting process to remove redundant rules after the learning process, and (c) a rule merging process to deal with the overlapping rules that commonly occur between the clusters. In the first process, we have modified the clustering mechanisms of the current available XCS and developed a new accelerate learning method to improve the quality of the evolved rule population. In the second process, an effective rule compacting algorithm is utilized. The rule merging process is based on our newly proposed agglomerative hierarchical rule merging algorithm, which comprises the following steps: (i) all the generated rules are modeled by a graph, with each rule representing a node; (ii) the vertices in the graph are merged to form a number of sub-graphs (i.e. rule clusters) under some pre-defined criteria, which generates the final rule set to represent the clusters; (iii) each data is re-checked and assigned to a cluster that it belongs to, guided by the final rule set. In our experiments, we compared the proposed XCSc with CHAMELEON, a benchmark algorithm well known for its excellent performance, on a number of challenging data sets. The results show that the proposed approach outperforms CHAMELEON in the successful rate, and also demonstrates good stability.
THE NON-COMMUTATIVE A-POLYNOMIAL OF TWIST KNOTS
Authors: GAROUFALIDIS STAVROS , SUN XINYU
Published: January 2011

The purpose of the paper is two-fold: to introduce a multivariable creative telescoping method, and to apply it in a problem of Quantum Topology: namely the computation of the non-commutative A-polynomial of twist knots.

Our multivariable creative telescoping method allows us to compute linear recursions for sums of the form [Formula: see text] given a recursion relation for [Formula: see text] and the hypergeometric kernel c(n, k). As an application of our method, we explicitly compute the non-commutative A-polynomial for twist knots with -15 and 15 crossings.

The non-commutative A-polynomial of a knot encodes the monic, linear, minimal order q-difference equation satisfied by the sequence of colored Jones polynomials of the knot. Its specialization to q = 1 is conjectured to be the better-known A-polynomial of a knot, which encodes important information about the geometry and topology of the knot complement. Unlike the case of the Jones polynomial, which is easily computable for knots with 50 crossings, the A-polynomial is harder to compute and already unknown for some knots with 12 crossings.
CONFIGURATION SPACE INTEGRALS FOR EMBEDDING SPACES AND THE HAEFLIGER INVARIANT
Authors: SAKAI KEIICHI
Published: January 2011

Let [Formula: see text] be the space of long j-knots in ℝn. In this paper, we introduce a graph complex [Formula: see text] and a linear map [Formula: see text] via configuration space integral, and prove that (1) when both n > j ≥ 3 are odd, I is a cochain map if restricted to graphs with at most one loop component, (2) when n - j ≥ 2 is even, I is a cochain map if restricted to tree graphs, and (3) when n - j ≥ 3 is odd, I added a correction term produces a (2n - 3j - 3)-cocycle of [Formula: see text] which gives a new formulation of the Haefliger invariant when n = 6k, j = 4k - 1 for some k.
THE PARAMETER-ROBUST NUMERICAL METHOD BASED ON DEFECT-CORRECTION TECHNIQUE FOR SINGULARLY PERTURBED DELAY DIFFERENTIAL EQUATIONS WITH LAYER BEHAVIOR
Authors: MOHAPATRA JUGAL , NATESAN SRINIVASAN
Published: January 2011

In this article, we consider a defect-correction method based on finite difference scheme for solving a singularly perturbed delay differential equation. We solve the equation using upwind finite difference scheme on piecewise-uniform Shishkin mesh, then apply the defect-correction technique that combines the stability of the upwind scheme and the higher-order central difference scheme. The method is shown to be convergent uniformly in the perturbation parameter and almost second-order convergence measured in the discrete maximum norm is obtained. Numerical results are presented, which are in agreement with the theoretical findings.
THE MODIFIED DIFFERENTIAL TRANSFORM METHOD FOR SOLVING OFF-CENTERED STAGNATION FLOW TOWARD A ROTATING DISC
Authors: ERFANI ESMAEEL , RASHIDI MOHAMMAD MEHDI , PARSA AMIR BASIRI
Published: January 2011

The similarity solution for the steady stagnation flow toward an off-centered rotating disc gives a system of nonlinear partial differential equations. These nonlinear differential equations are analytically solved by applying a newly developed method called DTM–Padé technique (the combination of the differential transform method (DTM) and the Padé approximation). This technique is extended to give solutions for nonlinear differential equations with boundary conditions at infinity. Graphical results are presented to investigate influence of the rotation ratio α on the radial velocity, azimuthal velocity, and the induced velocity. In order to show the effectiveness of the DTM–Padé technique, the results obtained from the DTM–Padé technique are compared with available solutions obtained using shooting method to generate the numerical solution. The obtained results demonstrate the reliability of the algorithm and the DTM–Padé technique is an attractive method in solving the systems of nonlinear partial differential equations.
A COMPUTATIONAL METHOD FOR HIGHLY STIFF NONLINEAR SPATIOTEMPORAL SYSTEMS
Authors: XU DAOLIN , ZHOU JIAXI
Published: January 2011

A computational method is proposed for solving highly stiff nonlinear ordinary/partial differential equations of dynamic systems. The method is based on exponential time-differencing in conjunction with a refined time-stepping algorithm and a fixed-point locating (FPL) scheme. The refined time-stepping algorithm allows computing temporal integration with high accuracy and efficiency, and the FPL scheme stabilizes the iteration process relating to spatial approximations and automatically traces the balancing conditions that offers superb stability robustness. Numerical experiments are carried out for a highly stiff reaction-diffusion system governed by the Kuramoto–Sivashinsky equation, and for the Burgers equation, van der Pol equation with strong nonlinearity.
MULTIPLE AND PERIODIC NOTCH PROBLEMS OF ELASTIC HALF-PLANE BY USING BIE BASED ON GREEN'S FUNCTION METHOD
Authors: CHEN Y. Z. , WANG Z. X.
Published: January 2011

This paper provides a modified complex potential for the fundamental solution, which is composed of a principal part and a complementary part. The suggested complex potential satisfies the traction free condition along the boundary of half-plane in advance. After using the Somigliana identity or the Betti's reciprocal theorem between the physical field and the field of the fundamental solution, a complex variable boundary integral equation (BIE) for the notch problem in elastic half-plane is obtained. A compact derivation for the BIE is presented. By using the BIE, multiple notch problems of elastic half-plane can be solved numerically. In the method, there is no limitation for the configuration of notches. Many problems with the elliptic notch or the square notch are solved successfully. For the periodic notch problem, the remainder estimation technique is suggested. This technique provides an effective way for the solution of periodic notch problem.
ON ASYMPTOTIC VALUES OF CANONICAL QUADRATIC L-FUNCTIONS
Authors: TEMPLIER NICOLAS
Published: January 2011

We establish an asymptotic for the first moment of Hecke L-series associated to canonical characters on imaginary quadratic fields. This provides another proof and improves recent results by Masri and Kim–Masri–Yang.
A NEW CONSTRUCTION OF p-ADIC RANKIN CONVOLUTIONS IN THE CASE OF POSITIVE SLOPE
Authors: VIENNEY MATHIEU
Published: January 2011

Given two newforms f and g of respective weights k and l with l < k, Hida constructed a p-adic L-function interpolating the values of the Rankin convolution of f and g in the critical strip l ≤ s ≤ k. However, this construction works only if f is an ordinary form. Using a method developed by Panchishkin to construct p-adic L-function associated with modular forms, we generalize this construction to the case where the slope of f is small.
DYNAMICS OF A SEGMENTATION CLOCK MODEL WITH DISCRETE AND DISTRIBUTED DELAYS
Authors: FENG PENG
Published: January 2011

In this paper, we study the effects of time delays on the dynamics of a segmentation clock model with both discrete and distributed delays. Two cases are considered. The first case corresponds to the model with only distributed delay. The second case involves both discrete and distributed delay. Local stability analysis is carried out for all cases. Numerical simulations are also performed to illustrate the results.
Geochemical indicators of metalliferous fertility in the Carboniferous San Blas pluton, Sierra de Velasco, Argentina
Authors: Rossi J. N. , Toselli A. J. , Basei M. A. , Sial A. N. , Baez M.
Published: January 2011

In the Sierra de Velasco, northwestern Argentina, undeformed Lower Carboniferous granitoids (350–334 Ma) intrude deformed Lower Ordovician granites and have been emplaced by passive mechanisms, typical of tensional environments. The semi-elliptic, about 300 km
2
shallow-emplaced San Blas pluton is 340–330 Ma old, with εNd
t
between −1.3 and −1.8 which indicates that, different from the nearby Famatinian–Ordovician granitoids, the San Blas pluton had a relatively brief crustal residence, with an interaction between asthenospheric material and greywackes. The cupola of the pluton was almost totally eroded down during the Upper Carboniferous.

The San Blas pluton is a porphyritic granite composed mainly of monzogranite to syenogranite and shows graphic intergrowth and miarolitic cavities up to 5 cm in diameter, filled with quartz. Two different textures are recognized: perthitic microcline megacrysts (30–45 vol%) set in a medium- to coarse-grained groundmass of quartz, microcline and oligoclase, with sericitic alteration. Biotite, muscovite, apatite, zircon, fluorite and opaque minerals are the accessory phases. The other textural variation consists in microcline megacrysts (10%–15 vol%) and a fine-grained groundmass, of quartz, microcline and oligoclase, biotite, apatite, muscovite, zircon and magnetite.

The average SiO
2
content in this pluton is 74.94%, the ASI=1.1, CaO and MgO are less than 1%, total Fe
2
O
3
and P
2
O
5
contents are low, and K
2
O>Na
2
O. Low Ba, Sr and high Rb contents, coupled with Sn contents (
c.
15 ppm), W (
c.
380 ppm), Nb, Y, Ta, Th and U confirm this is a special granite. The K/Rb ratio (
c.
75) indicates that Rb has been fractionated to the residual melt whereas the Zr/Hf (
c.
25) demonstrates that hydrothermal alteration occurred. The Sr/Eu ratio of
c.
75 along other geochemical features characterize this pluton as a fertile evolved granite.

The chondrite-normalized rare earth element (REE) diagram shows the tetrad effect that allows the subdivision of the lanthanides into four groups.

In general, the tetrad effect is recognized in evolved granites and products of hydrothermal alteration such as greisens. The above-mentioned features show that the San Blas granite is fertile, and the absence of ore deposits has been probably caused by erosion of a mineralized cupola during Carboniferous and Cenozoic exhumation. The finding of alluvial cassiterite and wolframite in drainage systems is the first evidence of the fertile character of this granite.
Evolution of metallogeny of granitic pegmatites associated with orogens throughout geological time
Authors: Tkachev A. V.
Published: January 2011

Since
c.
3.1 Ga, pegmatite mineral deposits in orogenic areas have been formed throughout geological time in pulses, alternating with total absence of generating activity. The higher activity peaks of 2.65–2.60, 1.90–1.85, 1.00–0.95, and 0.30–0.25 Ga suggest a quasi-regular periodicity of 0.8±0.1 Ga. This series is dominated by pegmatites of Laurasian blocks. The lower peaks at 2.85–2.80, 2.10–2.05, 1.20–1.15, and the higher one at 0.55–0.50 make up another series represented by pegmatites in Gondwanan blocks only. Each pegmatite class is characterized by a life cycle of its own, from inception to peak through to decline and eventual extinction. The longest cycle is recorded for the rare-metal class deposits, which first appeared in the Mesoarchaean and persisted through all the later eras, deteriorating gradually after the Early Precambrian. Muscovite pegmatites first appeared in the Palaeoproterozoic and reached the end of their life cycle at the Palaeozoic–Mesozoic boundary. The miarolitic class of pegmatite deposits in orogenic setting first came into being in the terminal Mesoproterozoic and dominated the pegmatite metallogeny of many Phanerozoic belts. The evolution of the pegmatite classes was controlled by the general cooling of the Earth and by associated changes in the tectonics of the lithosphere.

Supplementary material:

Geochronological data used is available at
http://www.geolsoc.org.uk/SUP18435
.
Late Neoproterozoic-Cambrian granitic magmatism in the Araçuaí orogen (Brazil), the Eastern Brazilian Pegmatite Province and related mineral resources
Authors: Pedrosa-Soares A. C. , De Campos Cristina P. , Noce Carlos , Silva Luiz Carlos , Novo Tiago , Roncato Jorge , Medeiros Sílvia , Castañeda Cristiane , Queiroga Gláucia , Dantas Elton , Dussin Ivo , Alkmim Fernando
Published: January 2011

The Araçuaí orogen extends from the eastern edge of the São Francisco craton to the Atlantic margin, in southeastern Brazil. Orogenic igneous rocks, formed from
c.
630 to
c.
480 Ma, cover one third of this huge area, building up the Eastern Brazilian Pegmatite Province and the most important dimension stone province of Brazil. G1 supersuite (630–585 Ma) mainly consists of tonalite to granodiorite, with mafic to dioritic facies and enclaves, representing a continental calc-alkaline magmatic arc. G2 supersuite mostly includes S-type granites formed during the syn-collisional stage (585–560 Ma), from relatively shallow two-mica granites and related gem-rich pegmatites to deep garnet-biotite granites that are the site of yellow dimension stone deposits. The typical G3 rocks (545–525 Ma) are non-foliated garnet-cordierite leucogranites, making up autochthonous patches and veins. At the post-collisional stage (530–480 Ma), G4 and G5 supersuites were generated. The S-type G4 supersuite mostly consists of garnet-bearing two-mica leucogranites that are the source of many pegmatites mined for tourmalines and many other gems, lithium (spodumene) ore and industrial feldspar. G5 supersuite, consisting of high-K–Fe calc-alkaline to alkaline granitic and/or charnockitic to dioritic/noritic intrusions, is the source of aquamarine-topaz-rich pegmatites but mainly of a large dimension stone production.
Tourmaline nodules: products of devolatilization within the final evolutionary stage of granitic melt?
Authors: Balen Dražen , Broska Igor
Published: January 2011

The origin of tourmaline nodules, and of their peculiar textures found in peripheral parts of the Moslavačka Gora (Croatia) Cretaceous peraluminous granite are connected with the separation of a late-stage boron-rich volatile fluid phase that exsolved from the crystallizing magma. Based on field, mineralogical and textural observations, tourmaline nodules were formed during the final stage of granite evolution when undersaturated granite magma intruded to shallow crustal horizons, become saturated and exsolved a fluid phase from residual melt as buoyant bubbles, or pockets. Calculated
P–T
conditions at emplacement level are
c.
720 °C, 70–270 MPa, and water content in the melt up to 4.2 wt%.

Two distinct occurrence types of tourmalines have been distinguished: disseminated and nodular tourmalines. Disseminated tourmaline, crystallized during magmatic stage, is typical schorl while nodular tourmaline composition is shifted toward dravite. The increase of dravite in nodular tourmaline is attributed to mixing of the fluid phase from the residual melt with fluid from the wall rocks.

The pressure decrease and related cooling at shallow crustal levels can be considered as a major factor controlling fluid behaviour, formation of a volatile phase, and the crystallization path in the Moslavačka Gora granite body.
Geochemical characteristics of Miocene Fe-Cu–Pb–Zn granitoids associated mineralization in the Chichibu skarn deposit (central Japan): evidence for magmatic fluids generation coexisting with granitic melt
Authors: Ishiyama D. , Miyata M. , Shibata S. , Satoh H. , Mizuta T. , Fukuyama M. , Ogasawara M.
Published: January 2011

In this work we study mechanisms and timing of magmatic fluid generation during magma emplacement. Our focus is the Miocene calc-alkaline granitic rocks from the Chichibu mining area, in Japan. The granitoids consist of northern and southern Bodies and of the Daikoku Altered stocks. Cathodoluminescence observation of quartz phenocrysts from the northern body point towards magmatic resorption, which is thought to be caused by mixing between a more differentiated and a more primitive magma. The coexistence of vapour-rich two-phase and halite-bearing polyphase fluid inclusions in a single quartz crystal from the northern Body supports the possibility of pressure decrease during magma emplacement. The magmatic fluids that originated the Chichibu deposit are thought to have been generated by pressure release, related to magmatic differentiation when the SiO
2
-content reaches about 65 wt%. As a result, heavy metals, such as copper, gold and arsenic, coexisting with the silicate melt, were transported into the sedimentary strata through degassing of magmatic fluids. A later major fault system caused the intercalation between heavy-metal-free limestone and orebodies, as a secondary skarn-building process took place in the dominant limestone area.
Spinal regions involved in baroreflex control of renal sympathetic nerve activity in the rat
Authors: Zahner Matthew R. , Schramm Lawrence P.
Published: January 2011

Spinal cord injury causes debilitating cardiovascular disturbances. The etiology of these disturbances remains obscure, partly because the locations of spinal cord pathways important for sympathetic control of cardiovascular function have not been thoroughly studied. To elucidate these pathways, we examined regions of the thoracic spinal cord important for reflex sympathetic control of arterial pressure (AP). In anesthetized rats, baroreceptor relationships between pharmacologically induced changes in AP and changes in left renal sympathetic nerve activity (RSNA) were generated in spinally intact rats and after acute surgical hemisection of either the dorsal, left, or right T8 spinal cord. None of these individual spinal lesions prevented the baroreceptor-mediated increases in RSNA caused by decreases in AP. Thus, baroreceptor-mediated increases in RSNA in rats are mediated by relatively diffuse, bilateral, descending, excitatory projections. The ability to reduce RSNA at increased AP was impaired after both dorsal and left hemisections, and baroreceptor gain was significantly decreased. Baroreceptor-induced maximum decreases in RSNA were not affected by right hemisections. However, baroreflex gain was impaired. Because both dorsal and left hemisections, but not right hemisections, attenuated the decrease in RSNA at elevated AP, we conclude that pathways involved in the tonic inhibition of spinal sources of sympathetic activity descend ipsilaterally in the dorsal spinal cord. Our results show that many lesions that do not fully transect the spinal cord spare portions of both descending excitatory pathways that may prevent orthostatic hypotension and descending inhibitory pathways that reduce the incidence of autonomic dysreflexia.
Low abundance of sweat duct Cl−channel CFTR in both healthy and cystic fibrosis athletes with exceptionally salty sweat during exercise
Authors: Brown Mary Beth , Haack Karla K. V. , Pollack Brian P. , Millard-Stafford Mindy , McCarty Nael A.
Published: January 2011

To understand potential mechanisms explaining interindividual variability observed in human sweat sodium concentration ([Na+]), we investigated the relationship among [Na+] of thermoregulatory sweat, plasma membrane expression of Na+and Cl−transport proteins in biopsied human eccrine sweat ducts, and basal levels of vasopressin (AVP) and aldosterone. Lower ductal luminal membrane expression of the Cl−channel cystic fibrosis transmembrane conductance regulator (CFTR) was observed in immunofluorescent staining of sweat glands from healthy young adults identified as exceptionally “salty sweaters” (SS) ( n = 6, P < 0.05) and from patients with cystic fibrosis (CF) ( n = 6, P < 0.005) compared with ducts from healthy young adults with “typical” sweat [Na+] (control, n = 6). Genetic testing of healthy subjects did not reveal any heterozygotes (“carriers”) for any of the 39 most common disease-causing CFTR mutations in the United States. SS had higher baseline plasma [AVP] compared with control ( P = 0.029). Immunostaining to investigate a potential relationship between higher plasma [AVP] (and sweat [Na+]) and ductal membrane aquaporin-5 revealed for all groups a relatively sparse and location-dependent ductal expression of the water channel with localization primarily to the secretory coil. Availability of CFTR for NaCl transport across the ductal membrane appears related to the significant physiological variability observed in sweat salt concentration in apparently healthy humans. At present, a heritable link between healthy salty sweaters and the most prevalent disease-causing CFTR mutations cannot be established.
Phagocyte-like NADPH oxidase generates ROS in INS 832/13 cells and rat islets: role of protein prenylation
Authors: Syed Ismail , Kyathanahalli Chandrashekara N. , Kowluru Anjaneyulu
Published: January 2011

Recent evidence suggests that an acute increase in the generation of phagocyte-like NADPH-oxidase (Nox)-mediated reactive oxygen species (ROS) may be necessary for glucose-stimulated insulin secretion. Using rat islets and INS 832/13 cells, we tested the hypothesis that activation of specific G proteins is necessary for nutrient-mediated intracellular generation of ROS. Stimulation of β-cells with glucose or a mixture of mitochondrial fuels (mono-methylsuccinate plus α-ketoisocaproic acid) markedly elevated intracellular accumulation of ROS, which was attenuated by selective inhibitors of Nox (e.g., apocynin or diphenyleneiodonium chloride) or short interfering RNA-mediated knockdown of p47phox, one of the subunits of Nox. Selective inhibitors of protein prenylation (FTI-277 or GGTI-2147) markedly inhibited nutrient-induced ROS generation, suggesting that activation of one (or more) prenylated small G proteins and/or γ-subunits of trimeric G proteins is involved in this signaling axis. Depletion of endogenous GTP levels with mycophenolic acid significantly reduced glucose-induced activation of Rac1 and ROS generation in these cells. Other immunosuppressants, like cyclosporine A or rapamycin, which do not deplete endogenous GTP levels, failed to affect glucose-induced ROS generation, suggesting that endogenous GTP is necessary for glucose-induced Nox activation and ROS generation. Treatment of INS 832/13 cells or rat islets with pertussis toxin (Ptx), which ADP ribosylates and inhibits inhibitory class of trimeric G proteins (i.e., Gior Go), significantly attenuated glucose-induced ROS generation in these cells, implicating activation of a Ptx-sensitive G protein in these signaling cascade. Together, our findings suggest a prenylated Ptx-sensitive signaling step couples Rac1 activation in the signaling steps necessary for glucose-mediated generation of ROS in the pancreatic β-cells.