bluuebunny/crossref_metadata_2025 huggingface dataset:
Prevalence and Fimbrial Genotype Distribution of Poultry Salmonella Isolates in China (2006 to 2012)
Authors: Gong Jiansen , Zhang Jinqiu , Xu Ming , Zhu Chunhong , Yu Yan , Liu Xuexian , Kelly Patrick , Xu Bu , Wang Chengming
Published: November 2013

In this study, a total of 323
Salmonella enterica
strains were isolated from 3,566 rectal swab samples of 51 poultry farms in seven regions of 12 provinces of China between 2006 and 2012. The prevalences of
Salmonella
sp. carriage were 12.4% in geese (66 positive/533 samples), 10.4% in turkeys (32/309), 9.8% in chickens (167/1,706), 6.8% in ducks (41/601), and 4.1% in pigeons (17/417), respectively. These isolates belonged to 20 serovars, in which the most frequent serovars were
S. enterica
serovar Gallinarum biovar Pullorum (herein,
S
. Pullorum) (55 isolates, 17.0%),
S. enterica
serovar Typhimurium (50 isolates, 15.5%), and
S. enterica
serovar Enteritidis (39 isolates, 12.1%). Overall,
S
. Typhimurium was the most commonly detected serovar; among the individual species,
S
. Pullorum was most commonly isolated from chickens,
S
. Enteritidis was most common in ducks,
S
. Typhimurium was most common in geese and pigeons, and
S. enterica
serovar Saintpaul was most common in turkeys. PCR determination of 20 fimbrial genes demonstrated the presence of
bcfD
,
csgA
,
fimA
,
stdB
, and
sthE
genes and the absence of
staA
and
stgA
genes in these isolates, and other loci were variably distributed, with frequency values ranging from 11.8 to 99.1%. These 323
Salmonella
isolates were subdivided into 41 different fimbrial genotypes, and of these isolate, 285 strains (88.2%) had 12 to 14 fimbrial genes. Our findings indicated that the
Salmonella
isolates from different poultry species were phenotypically and genetically diverse and that some fimbrial genes are more frequently associated with serovars or serogroups.
Quorum-Sensing Regulation of Constitutive Plantaricin by Lactobacillus plantarum Strains under a Model System for Vegetables and Fruits
Authors: Rizzello Carlo G. , Filannino Pasquale , Di Cagno Raffaella , Calasso Maria , Gobbetti Marco
Published: November 2013

This study aimed at investigating the regulatory system of bacteriocin synthesis by
Lactobacillus plantarum
strains in vegetables and fruits in a model system. Sterile and neutralized cell-free supernatant (CFS) from
L. plantarum
strains grown in MRS broth showed
in vitro
antimicrobial activities toward various indicator strains. The highest activity was that of
L. plantarum
C2. The antimicrobial activity was further assayed on vegetable and fruit agar plates (solid conditions) and in juices (liquid conditions). A regulatory mechanism of bacteriocin synthesis via quorum sensing was hypothesized. The synthesis of antimicrobial compounds seemed to be constitutive under solid conditions of growth on vegetable and fruit agar plates. In contrast, it depended on the size of the inoculum when
L. plantarum
C2 was grown in carrot juice. Only the inoculum of ca. 9.0 log CFU ml
−1
produced detectable activity. The genes
plnA
,
plnEF
,
plnG
, and
plnH
were found in all
L. plantarum
strains. The genes
plnJK
and
plnN
were detected in only three or four strains. Reverse-phase high-performance liquid chromatography purification and mass spectrometry analysis revealed the presence of a mixture of eight peptides in the most active fraction of the CFS from
L. plantarum
C2. Active peptides were encrypted into bacteriocin precursors, such as plantaricins PlnJ/K and PlnH and PlnG, which are involved in the ABC transport system. A real-time PCR assay showed an increase in the expression of
plnJK
and
plnG
during growth of
L. plantarum
C2 in carrot juice.
Uncovering a Microbial Enigma: Isolation and Characterization of the Streamer-Generating, Iron-Oxidizing, Acidophilic Bacterium “Ferrovum myxofaciens”
Authors: Johnson D. Barrie , Hallberg Kevin B. , Hedrich Sabrina
Published: November 2013

A betaproteobacterium, shown by molecular techniques to have widespread global distribution in extremely acidic (pH 2 to 4) ferruginous mine waters and also to be a major component of “acid streamer” growths in mine-impacted water bodies, has proven to be recalcitrant to enrichment and isolation. A modified “overlay” solid medium was devised and used to isolate this bacterium from a number of mine water samples. The physiological and phylogenetic characteristics of a pure culture of an isolate from an abandoned copper mine (“
Ferrovum myxofaciens
” strain P3G) have been elucidated. “
F. myxofaciens
” is an extremely acidophilic, psychrotolerant obligate autotroph that appears to use only ferrous iron as an electron donor and oxygen as an electron acceptor. It appears to use the Calvin-Benson-Bassham pathway to fix CO
2
and is diazotrophic. It also produces copious amounts of extracellular polymeric materials that cause cells to attach to each other (and to form small streamer-like growth
in vitro
) and to different solid surfaces. “
F. myxofaciens
” can catalyze the oxidative dissolution of pyrite and, like many other acidophiles, is tolerant of many (cationic) transition metals. “
F. myxofaciens
” and related clone sequences form a monophyletic group within the
Betaproteobacteria
distantly related to classified orders, with genera of the family
Nitrosomonadaceae
(lithoautotrophic, ammonium-oxidizing neutrophiles) as the closest relatives. On the basis of the phylogenetic and phenotypic differences of “
F. myxofaciens
” and other
Betaproteobacteria
, a new family, “
Ferrovaceae
,” and order, “
Ferrovales
,” within the class
Betaproteobacteria
are proposed. “
F. myxofaciens
” is the first extreme acidophile to be described in the class
Betaproteobacteria
.
Genetically Engineered Immunomodulatory Streptococcus thermophilus Strains Producing Antioxidant Enzymes Exhibit Enhanced Anti-Inflammatory Activities
Authors: del Carmen Silvina , de Moreno de LeBlanc Alejandra , Martin Rebeca , Chain Florian , Langella Philippe , Bermúdez-Humarán Luis G. , LeBlanc Jean Guy
Published: November 2013

The aims of this study were to develop strains of lactic acid bacteria (LAB) having both immunomodulatory and antioxidant properties and to evaluate their anti-inflammatory effects both
in vitro
, in different cellular models, and
in vivo
, in a mouse model of colitis. Different
Lactobacillus delbrueckii
subsp.
bulgaricus
and
Streptococcus thermophilus
strains were cocultured with primary cultures of mononuclear cells. Analysis of the pro- and anti-inflammatory cytokines secreted by these cells after coincubation with candidate bacteria revealed that
L. delbrueckii
subsp.
bulgaricus
CRL 864 and
S. thermophilus
CRL 807 display the highest anti-inflammatory profiles
in vitro
. Moreover, these results were confirmed
in vivo
by the determination of the cytokine profiles in large intestine samples of mice fed with these strains.
S. thermophilus
CRL 807 was then transformed with two different plasmids harboring the genes encoding catalase (CAT) or superoxide dismutase (SOD) antioxidant enzymes, and the anti-inflammatory effects of recombinant streptococci were evaluated in a mouse model of colitis induced by trinitrobenzenesulfonic acid (TNBS). Our results showed a decrease in weight loss, lower liver microbial translocation, lower macroscopic and microscopic damage scores, and modulation of the cytokine production in the large intestines of mice treated with either CAT- or SOD-producing streptococci compared to those in mice treated with the wild-type strain or control mice without any treatment. Furthermore, the greatest anti-inflammatory activity was observed in mice receiving a mixture of both CAT- and SOD-producing streptococci. The addition of
L. delbrueckii
subsp.
bulgaricus
CRL 864 to this mixture did not improve their beneficial effects. These findings show that genetically engineering a candidate bacterium (e.g.,
S. thermophilus
CRL 807) with intrinsic immunomodulatory properties by introducing a gene expressing an antioxidant enzyme enhances its anti-inflammatory activities.
Evolution of the Cytosolic Iron-Sulfur Cluster Assembly Machinery in Blastocystis Species and Other Microbial Eukaryotes
Authors: Tsaousis Anastasios D. , Gentekaki Eleni , Eme Laura , Gaston Daniel , Roger Andrew J.
Published: November 2013

The cytosolic iron/sulfur cluster assembly (CIA) machinery is responsible for the assembly of cytosolic and nuclear iron/sulfur clusters, cofactors that are vital for all living cells. This machinery is uniquely found in eukaryotes and consists of at least eight proteins in opisthokont lineages, such as animals and fungi. We sought to identify and characterize homologues of the CIA system proteins in the anaerobic stramenopile parasite
Blastocystis
sp. strain NandII. We identified transcripts encoding six of the components—Cia1, Cia2, MMS19, Nbp35, Nar1, and a putative Tah18—and showed using immunofluorescence microscopy, immunoelectron microscopy, and subcellular fractionation that the last three of them localized to the cytoplasm of the cell. We then used comparative genomic and phylogenetic approaches to investigate the evolutionary history of these proteins. While most
Blastocystis
homologues branch with their eukaryotic counterparts, the putative
Blastocystis
Tah18 seems to have a separate evolutionary origin and therefore possibly a different function. Furthermore, our phylogenomic analyses revealed that all eight CIA components described in opisthokonts originated before the diversification of extant eukaryotic lineages and were likely already present in the last eukaryotic common ancestor (LECA). The Nbp35, Nar1 Cia1, and Cia2 proteins have been conserved during the subsequent evolutionary diversification of eukaryotes and are present in virtually all extant lineages, whereas the other CIA proteins have patchy phylogenetic distributions. Cia2 appears to be homologous to SufT, a component of the prokaryotic sulfur utilization factors (SUF) system, making this the first reported evolutionary link between the CIA and any other Fe/S biogenesis pathway. All of our results suggest that the CIA machinery is an ubiquitous biosynthetic pathway in eukaryotes, but its apparent plasticity in composition raises questions regarding how it functions in nonmodel organisms and how it interfaces with various iron/sulfur cluster systems (i.e., the iron/sulfur cluster, nitrogen fixation, and/or SUF system) found in eukaryotic cells.
Mitochondrial and Nucleolar Localization of Cysteine Desulfurase Nfs and the Scaffold Protein Isu in Trypanosoma brucei
Authors: Kovářová Julie , Horáková Eva , Changmai Piya , Vancová Marie , Lukeš Julius
Published: November 2013

Trypanosoma brucei
has a complex life cycle during which its single mitochondrion is subjected to major metabolic and morphological changes. While the procyclic stage (PS) of the insect vector contains a large and reticulated mitochondrion, its counterpart in the bloodstream stage (BS) parasitizing mammals is highly reduced and seems to be devoid of most functions. We show here that key Fe-S cluster assembly proteins are still present and active in this organelle and that produced clusters are incorporated into overexpressed enzymes. Importantly, the cysteine desulfurase Nfs, equipped with the nuclear localization signal, was detected in the nucleolus of both
T. brucei
life stages. The scaffold protein Isu, an interacting partner of Nfs, was also found to have a dual localization in the mitochondrion and the nucleolus, while frataxin and both ferredoxins are confined to the mitochondrion. Moreover, upon depletion of Isu, cytosolic tRNA thiolation dropped in the PS but not BS parasites.
Kinetics of
nif
Gene Expression in a Nitrogen-Fixing Bacterium
Authors: Poza-Carrión César , Jiménez-Vicente Emilio , Navarro-Rodríguez Mónica , Echavarri-Erasun Carlos , Rubio Luis M.
Published: November 2013

Nitrogen fixation is a tightly regulated trait. Switching from N
2
fixation-repressing conditions to the N
2
-fixing state is carefully controlled in diazotrophic bacteria mainly because of the high energy demand that it imposes. By using quantitative real-time PCR and quantitative immunoblotting, we show here how nitrogen fixation (
nif
) gene expression develops in
Azotobacter vinelandii
upon derepression. Transient expression of the transcriptional activator-encoding gene,
nifA
, was followed by subsequent, longer-duration waves of expression of the nitrogenase biosynthetic and structural genes. Importantly, expression timing, expression levels, and NifA dependence varied greatly among the
nif
operons. Moreover, the exact concentrations of Nif proteins and their changes over time were determined for the first time. Nif protein concentrations were exquisitely balanced, with FeMo cofactor biosynthetic proteins accumulating at levels 50- to 100-fold lower than those of the structural proteins. Mutants lacking nitrogenase structural genes or impaired in FeMo cofactor biosynthesis showed overenhanced responses to derepression that were proportional to the degree of nitrogenase activity impairment, consistent with the existence of at least two negative-feedback regulatory mechanisms. The first such mechanism responded to the levels of fixed nitrogen, whereas the second mechanism appeared to respond to the levels of the mature NifDK component. Altogether, these findings provide a framework to engineer N
2
fixation in nondiazotrophs.
Saturating Mutagenesis of an Essential Gene: a Majority of the Neisseria gonorrhoeae Major Outer Membrane Porin (PorB) Is Mutable
Authors: Chen Adrienne , Seifert H. Steven
Published: November 2013

The major outer membrane porin (PorB) of
Neisseria gonorrhoeae
is an essential protein that mediates ion exchange between the organism and its environment and also plays multiple roles in human host pathogenesis. To facilitate structure-function studies of porin's multiple roles, we performed saturating mutagenesis at the
porB
locus and used deep sequencing to identify essential versus mutable residues. Random mutations in
porB
were generated in a plasmid vector, and mutant gene pools were transformed into
N. gonorrhoeae
to select for alleles that maintained bacterial viability. Deep sequencing of the input plasmid pools and the output
N. gonorrhoeae
genomic DNA pools identified mutations present in each, and the mutations in both pools were compared to determine which changes could be tolerated by the organism. We examined the mutability of 328 amino acids in the mature PorB protein and found that 308 of them were likely to be mutable and that 20 amino acids were likely to be nonmutable. A subset of these predictions was validated experimentally. This approach to identifying essential amino acids in a protein of interest introduces an additional application for next-generation sequencing technology and provides a template for future studies of both porin and other essential bacterial genes.
Genomic and Proteomic Studies on Plesiomonas shigelloides Lipopolysaccharide Core Biosynthesis
Authors: Aquilini Eleonora , Merino Susana , Regué Miguel , Tomás Juan M.
Published: November 2013

We report here the identification of
waa
clusters with the genes required for the biosynthesis of the core lipopolysaccharides (LPS) of two
Plesiomonas shigelloides
strains. Both
P. shigelloides
waa
clusters shared all of the genes besides the ones flanking
waaL
. In both strains, all of the genes were found in the
waa
gene cluster, although one common core biosynthetic gene (
wapG
) was found in a different chromosome location outside the cluster. Since
P. shigelloides
and
Klebsiella pneumoniae
share a core LPS carbohydrate backbone extending up at least to the second outer-core residue, the functions of the common
P. shigelloides
genes were elucidated by genetic complementation studies using well-defined
K. pneumoniae
mutants. The function of strain-specific inner- or outer-core genes was identified by using as a surrogate acceptor LPS from three well-defined
K. pneumoniae
core LPS mutants. Using this strategy, we were able to assign a proteomic function to all of the
P. shigelloides
waa
genes identified in the two strains encoding six new glycosyltransferases (WapA, -B, -C, -D, -F, and -G).
P. shigelloides
demonstrated an important variety of core LPS structures, despite being a single species of the genus, as well as high homologous recombination in housekeeping genes.
Treatment of Post-Mastectomy Pain Syndrome with Acupuncture: A Case Report
Authors: Bauml Joshua , Basal Coby , Mao Jun J
Published: November 2013

Post-mastectomy pain syndrome (PMPS) is a common and severe neuropathic pain syndrome arising after breast surgery. Since few effective allopathic treatments exist for PMPS, many patients may seek assistance from complementary and alternative medicine. Here, we report a case of a woman with severe and persistent PMPS who was successfully treated with acupuncture.
Factors influencing clinical trial site selection in Europe: the Survey of Attitudes towards Trial sites in Europe (the SAT-EU Study)
Authors: Gehring Marta , Taylor Rod S , Mellody Marie , Casteels Brigitte , Piazzi Angela , Gensini Gianfranco , Ambrosio Giuseppe
Published: November 2013

Objectives

Applications to run clinical trials in Europe fell 25% between 2007 and 2011. Costs, speed of approvals and shortcomings of European Clinical Trial Directive are commonly invoked to explain this unsatisfactory performance. However, no hard evidence is available on the actual weight of these factors or has it been previously investigated whether other criteria may also impact clinical trial site selection.

Design

The Survey of Attitudes towards Trial sites in Europe (SAT-EU Study) was an anonymous, cross-sectional web-based survey that systematically assessed factors impacting European clinical trial site selection. It explored 19 factors across investigator-driven, hospital-driven and environment-driven criteria, and costs. It also surveyed perceptions of the European trial environment.

Setting and participants

Clinical research organisations (CROs), academic clinical trial units (CTUs) and industry invited to respond.

Outcome measures

Primary outcome: weight assigned to each factor hypothesised to impact trial site selection and trial incidence. Secondary outcome: desirability of European countries to run clinical trials.

Results

Responses were obtained from 485 professionals in 34 countries: 49% from BioPharma, 40% from CTUs or CROs. Investigator-dependent, environment-dependent and hospital-dependent factors were rated highly important, costs being less important (p<0.0001). Within environment-driven criteria, pool of eligible patients, speed of approvals and presence of disease-management networks were significantly more important than costs or government financial incentives (p<0.0001). The pattern of response was consistent across respondent groupings (CTU vs CRO vs industry). Considerable variability was demonstrated in the perceived receptivity of countries to undertake clinical trials, with Germany, the UK and the Netherlands rated the best trial markets (p<0.0001).

Conclusions

Investigator-dependent factors and ease of approval dominate trial site selection, while costs appear less important. Fostering competitiveness of European clinical research may not require additional government spending/incentives. Rather, harmonisation of approval processes, greater visibility of centres of excellence and reduction of ‘hidden’ indirect costs, may bring significantly more clinical trials to Europe.
Evidence for the aetiology of human papillomavirus in oesophageal squamous cell carcinoma in the Chinese population: a meta-analysis
Authors: Liyanage Surabhi S , Rahman Bayzidur , Gao Zhanhai , Zheng Yang , Ridda Iman , Moa Aye , Newall Anthony T , Seale Holly , Li Qian , Liu Jun-Feng , MacIntyre C Raina
Published: November 2013

Objectives

We aimed to conduct a meta-analysis of human papillomavirus (HPV) as a risk factor for oesophageal squamous cell carcinoma (OSCC) in China, using all eligible studies published in the English and Chinese language literature.

Design

The random effect model was used to analyse the pooled OR. The I2and Q tests were included in the subgroup analyses.

Setting

Literature searches of databases including MEDLINE, PUBMED, EMBASE and Chinese National Knowledge Infrastructure (CNKI) and other available resources were performed to retrieve studies investigating OSCC tissue from Chinese participants for the presence of HPV DNA.

Primary outcome measure

A collective analysis of OSCC cases and control specimens was carried out from 15 case–control studies (6 in the English language and 9 in the Chinese language) for HPV prevalence.

Results

Of a total of 1177 OSCC and 1648 oesophageal control samples, 55% (642/1177) of cancer specimens and 27% (445/1648) of control samples were positive for HPV DNA. A positive strong association between HPV DNA and OSCC was observed among the included studies, with a pooled OR of 3.69 (95% CI 2.74 to 4.96). Heterogeneity and publication bias were not observed in the analysis. Subgroup analyses of the included studies also supported the measure of association of causal links between HPV and OSCC.

Conclusions

This meta-analysis provides the strongest evidence until now of an association between HPV and OSCC in the Chinese population. China has a high burden of OSCC, making this an important research finding. A strength and new contribution of this study is combining data from the English and Chinese language literature to analyse all studies conducted in China. These findings may inform the population level use of prophylactic HPV vaccination to reduce the burden of OSCC in China.
Nurse and manager perceptions of nurse initiated and managed antiretroviral therapy (NIMART) implementation in South Africa: a qualitative study
Authors: Davies Natasha Elaine Claire Garai , Homfray Mike , Venables Emilie Charlotte
Published: November 2013

Objective

To explore nurse and facility and programme manager perceptions of nurse initiated and managed antiretroviral therapy (NIMART) implementation in Gauteng, South Africa.

Design

In this qualitative study, in-depth interviews and focus group discussions were conducted to gain insight into participants’ experiences of NIMART implementation.

Setting

Participants came from urban, peri-urban and rural primary healthcare clinics in two Gauteng Province municipalities.

Participants

25 nurses and 18 managers who were actively involved in NIMART implementation were purposively sampled.

Results

The findings from this study reveal that, despite encountering numerous challenges including human resources, training and clinical mentoring and health systems issues, NIMART nurses and managers remained optimistic about their work. Study participants felt empowered by their expanded roles. Increased responsibilities associated with NIMART implementation encouraged better use of creative problem-solving and teamwork to facilitate integration of NIMART into existing clinic services. NIMART nurses perceived antiretroviral therapy (ART) patients to be more insightful about their illness, engaged in their HIV treatment and aware of the importance of adherence which enhanced nurse–patient relationships and increased their sense of job satisfaction.

Conclusions

Although the implementation of NIMART is complex, when NIMART is implemented well, ART access is increased and patient outcomes are improved. Supportive interventions which address the specific challenges faced by nurses providing NIMART now need to be implemented. Attempts should be made to replicate the positive aspects of NIMART implementation identified by participants as this may improve healthcare providers’ experiences of task-shifting.
The impact of new prehospital practitioners on ambulance transportation to the emergency department: a systematic review and meta-analysis
Authors: Tohira Hideo , Williams Teresa A , Jacobs Ian , Bremner Alexandra , Finn Judith
Published: November 2013

Objective

To conduct a systematic review and meta-analysis to examine the impact of new prehospital practitioners (NPPs), including emergency care practitioners (EmCPs), paramedic practitioners and extended care paramedics (ECPs), on ambulance transportation to the emergency department (ED).

Methods

We searched MEDLINE, Embase, CINAHL and AUSTHealth databases, and hand searched emergency medicine journals and journal reference lists for relevant papers. To be included, studies were required to target one type of NPP and compare outcomes such as the frequencies of conveyance to the ED, discharge at scene, subsequent ED attendance and/or appropriateness of care between NPPs and conventional ambulance crews. Three investigators independently selected relevant studies. The risk of bias in individual studies was assessed using a validated checklist. We conducted meta-analyses for comparisons which had acceptable heterogeneity (I2<75%) and reported pooled estimates of ORs with 95% CIs.

Results

13 studies were identified from 16 584 citation reports. EmCPs were most frequently studied. The majority of studies (77%) did not fully report important potential confounders. NPPs were less likely to convey patients to the ED and more likely to discharge patients at the scene than conventional ambulance crews. Pooled ORs for conveyance to the ED and discharge at the scene by ECPs were 0.09 (95% CI 0.04 to 0.18) and 10.5 (95% CI 5.8 to 19), respectively. The evidence for subsequent ED attendance and appropriateness of care was equivocal.

Conclusions

The NPP schemes reduced transport to the ED; however, the appropriateness of the decision of the NPPs and the safety of patients were not well supported by the reported studies.
The ‘rgr’ package for the R Open Source statistical computing and graphics environment - a tool to support geochemical data interpretation
Authors: Garrett Robert G.
Published: November 2013

The development of interactive computer graphics to support applied geochemistry over the last 40 years at the Geological Survey of Canada (GSC) is briefly discussed. The loss of an interactive computing environment, IDEAS, in 1995 based on a DEC VAX computer largely negated nine years of work, though the experience gained was invaluable. The availability of the commercial S-PLUS package in a Windows PC environment led to the redevelopment of most of the functionality of IDEAS in the S language for statistical analysis and graphics. In 2006 a request from a sister federal government department for the S-PLUS software led to the decision to translate the S functions into R, an Open-Source implementation of the S language, and therefore free to the user. Since that time all development has been in R, resulting in the 2007 release to the public of a package of tools, ‘rgr’, to assist applied geochemists in interpreting their data. Subsequently, ‘rgr’ has been updated and extended. The move to Open Source R and the release of the ‘rgr’ package on the Comprehensive R Archival Network (CRAN) has made these tools, and their documentation, available for Windows, Unix and Mac computing environments. The paper outlines the features of ‘rgr’ and illustrates key graphic and tabular displays. Its functionality is reviewed in the context of earlier GSC interactive graphics packages.

Supplementary Material:

this is available at
http://www.geolsoc.org.uk/SUP18713
An occurrence of
Palaeohelcura tridactyla
in the Arbuthnott–Garvock Group, Lower Devonian, at Friarton Quarry, Perth
Authors: Batchelor Richard A. , Garton Rosalind E.
Published: November 2013

Synopsis

An occurrence of
Palaeohelcura tridactyla
Gilmore 1926 arthropod tracks is described in inter-lava sediments, comprising mudstones and siltstones, from the Ochil Volcanic Formation, Arbuthnott–Garvock Group, Pragian Stage, Lower Devonian, at Friarton Quarry, Perth. This is believed to be the first record in Scotland of this trace fossil, which is usually interpreted as having been created by a scorpion-like arthropod.
Lasting alterations of the sodium current by short-term hyperlipidemia as a mechanism for initiation of cardiac remodeling
Authors: Biet M. , Morin N. , Benrezzak O. , Naimi F. , Bellanger S. , Baillargeon J. P. , Chouinard L. , Gallo-Payet N. , Carpentier A. C. , Dumaine R.
Published: November 2013

Clinical and animal studies indicate that increased fatty acid delivery to lean tissues induces cardiac electrical remodeling and alterations of cellular calcium homeostasis. Since this may represent a mechanism initiating cardiac dysfunction during establishment of insulin resistance and diabetes or anaerobic cardiac metabolism (ischemia), we sought to determine if short-term exposure to high plasma concentration of fatty acid in vivo was sufficient to alter the cardiac sodium current ( INa) in dog ventricular myocytes. Our results show that delivery of triglycerides and nonesterified fatty acids by infusion of Intralipid + heparin (IH) for 8 h increased the amplitude of INa by 43% and shifted its activation threshold by −5 mV, closer to the resting membrane potential. Steady-state inactivation (availability) of the channels was reduced by IH with no changes in recovery from inactivation. As a consequence, INa “window” current, a strong determinant of intracellular Na+ and Ca2+ concentrations, was significantly increased. The results indicate that increased circulating fatty acids alter INa gating in manners consistent with an increased cardiac excitability and augmentation of intracellular calcium. Moreover, these changes could still be measured after the dogs were left to recover for 12 h after IH perfusion, suggesting lasting changes in INa. Our results indicate that fatty acids rapidly induce cardiac remodeling and suggest that this process may be involved in the development of cardiac dysfunctions associated to insulin resistance and diabetes.
Autophagy mediates avian influenza H5N1 pseudotyped particle-induced lung inflammation through NF-κB and p38 MAPK signaling pathways
Authors: Pan Hong , Zhang Yijuan , Luo Zichao , Li Ping , Liu Lanlan , Wang Ce , Wang Hanzhong , Li Hongchang , Ma Yifan
Published: November 2013

Since avian influenza virus H5N1-induced hypercytokemia plays a key role in acute lung injury, understanding its molecular mechanism is highly desirable for discovering therapeutic targets against H5N1 infection. In the present study, we investigated the role of autophagy in H5N1-induced lung inflammation by using H5N1 pseudotyped viral particles (H5N1pps). The results showed that H5N1pps significantly induced autophagy both in A549 human lung epithelial cells and in mouse lung tissues, which was primarily due to hemagglutinin (HA) of H5N1 virus. Blocking autophagy with 3-methyladenine (an autophagy inhibitor) or siRNA knockdown of autophagy-related genes ( beclin1 and atg5) dramatically attenuated H5N1pp-induced proinflammatory cytokines and chemokines, such as IL-1β, TNF-α, IL-6, CCL2, and CCL5, both in vitro and in vivo. Autophagy-mediated inflammatory responses involved the activation of NF-κB and p38 MAPK signaling pathways, which required the presence of clathrin but did not rely on p62 or autophagosome-lysosome fusion. On the other hand, the activation of NF-κB also promoted H5N1pp-induced autophagosome formation. These data indicated a positive feedback loop between autophagy and NF-κB signaling cascade, which could exacerbate H5N1pp-induced lung inflammation. Our data demonstrated an essential role of autophagy in H5N1pp-triggered inflammatory responses, and targeting the autophagic pathway could be a promising strategy to treat H5N1 virus-caused lung inflammation.
Dielectric properties of myoglobin at 10 GHz by microwave cavity perturbation measurements
Authors: Bonura M. , Schirò G. , Cupane A.
Published: November 2013

We report on the temperature dependence, at microwave (mw) frequency, of the imaginary part of the dielectric constant (ε″) in myoglobin powder samples with different hydration levels (h). The measurements have been performed by the cavity perturbation technique, in the range of temperature 80–345 K. The sample is located inside a glass capillary along the axis of a cylindrical copper cavity, resonating in the TE011mode at 9.6 GHz, where the mw electric field has a node. By measuring the variation of the quality factor of the resonant cavity, one can extract the imaginary part of the dielectric constant. At temperatures higher than 230 K we observe an evident increase of the dielectric losses with increasing temperature; the effect scales almost linearly with hydration, indicating that it must be attributed to a relaxation of water in the hydration shell of the protein. Furthermore, ath≥0.18, we observe a clear peak in the ε″ vs.Tcurve, that shifts towards lower temperatures upon increasing hydration; this shows that the activation enthalpy of the hydration water relaxation decreases with hydration. More in general, our data show that the technique of microwave cavity perturbation allows one to study the dynamics of water molecules in the hydration shell of proteins and to extend information obtained with dielectric techniques to the mw frequencies.
Fault Detection for Quantized Networked Control Systems
Authors: Che Wei-Wei , Mei Zhi-Yong , Wang Yu-Long
Published: November 2013

The fault detection problem in the finite frequency domain for networked control systems with signal quantization is considered. With the logarithmic quantizer consideration, a quantized fault detection observer is designed by employing a performance index which is used to increase the fault sensitivity in finite frequency domain. The quantized measurement signals are dealt with by utilizing the sector bound method, in which the quantization error is treated as sector-bounded uncertainty. By using the Kalman-Yakubovich-Popov (GKYP) Lemma, an iterative LMI-based optimization algorithm is developed for designing the quantized fault detection observer. And a numerical example is given to illustrate the effectiveness of the proposed method.
Asymmetric Event-Driven Localization Algorithm in Constrained Space
Authors: Wang Ning , Qin Xiaolin , Xu Xingye
Published: November 2013

Existing technologies are inapplicable to localization in constrained space, especially when considering environmental factors. These methods with low localization accuracy cannot meet the location requirements in constrained space, for they usually call for lots of computation time and process resources. Moreover, they are easily interfered by environmental factors and attacks from other users. Consequently, in order to improve location accuracy in constrained space, an asymmetric event-driven localization algorithm (AELA) is proposed in this paper, which is based on the combination of event distribution and anchor node achieving a distributed location estimation strategy, so that it can satisfy the localization requirement of constrained space and achieve the high-accuracy localization with a small amount of events and anchor nodes. Meanwhile, to improve the accuracy of the algorithm, a set of candidate events are adopted to prune the event which does not meet location accuracy requirements. We finally perform experiments in indoor corridors, and the results show that the proposed algorithm has higher performances not only on localization accuracy and energy consumption but also on anti-interference ability than RSSI and MSP.
An Efficient Emergency Message Broadcasting Scheme in Vehicular Ad Hoc Networks
Authors: Dawood Hayder Salman , Wang Yuming
Published: November 2013

Broadcasting of emergency message (EM) in the vehicular Ad hoc networks (VANETs) plays a significant role in safety applications, which require immediate broadcasting of EM to the relevant vehicles located in the risk zone (RZ). This paper proposes an efficient emergency message broadcasting (EEMB) scheme in VANETs. This scheme aims at avoiding multiple accidents and reducing traffic jams by broadcasting EM at high speed and with low overhead. When an accident takes place, the crashed vehicle (CV) will choose the best relayer(s) and broadcast the EM. The relayer will also choose the best next relayer(s) and rebroadcast the EM further. This process continues until the EM covers the whole RZ. The EEMB scheme reduces the overhead caused by beacons by using the prediction method. Our proposed scheme also overcomes the network fragmentation problem either by choosing the vehicles moving in the opposite direction as the relayer(s) if there are no vehicles in the same direction or by using the store-carry-forward (SCF) mechanism when there are no vehicles moving in both directions. The simulation results have shown that the proposed scheme has better performance in terms of the risk zone latency (RZL) and the beacons overhead (BCO).
Unstart Coupling Mechanism Analysis of Multiple‐Modules Hypersonic Inlet
Authors: Hu Jichao , Chang Juntao , Wang Lei , Cao Shibin , Bao Wen
Published: November 2013

The combination of multiplemodules in parallel manner is an important way to achieve the much higher thrust of scramjet engine. For the multiple‐modules scramjet engine, when inlet unstarted oscillatory flow appears in a single‐module engine due to high backpressure, how to interact with each module by massflow spillage, and whether inlet unstart occurs in other modules are important issues. The unstarted flowfield and coupling characteristic for a three‐module hypersonic inlet caused by center module II and side module III were, conducted respectively. The results indicate that the other two hypersonic inlets are forced into unstarted flow when unstarted phenomenon appears on a single‐module hypersonic inlet due to high backpressure, and the reversed flow in the isolator dominates the formation, expansion, shrinkage, and disappearance of the vortexes, and thus, it is the major factor of unstart coupling of multiple‐modules hypersonic inlet. The coupling effect among multiple modules makes hypersonic inlet be more likely unstarted.
The Asymptotic Stability of the Generalized 3D Navier-Stokes Equations
Authors: Wang Wen-Juan , Jia Yan
Published: November 2013

We study the stability issue of the generalized 3D Navier-Stokes equations. It is shown that if the weak solutionuof the Navier-Stokes equations lies in the regular class∇u∈Lp(0,∞;Bq,∞0(ℝ3)),(2α/p)+(3/q)=2α,2<q<∞,0<α<1, then every weak solutionv(x,t)of the perturbed system converges asymptotically tou(x,t)asvt-utL2→0,t→∞.
Sliding Sector-Based Variable Structure Control of Continuous-Time Markov Jump Linear Systems Subject to Unknown Transition Rates
Authors: Xue Yan-Mei , Yang Jianwei , Liu Xiao-Mei
Published: November 2013

Based on sliding sector technique, the variable structure control for a class of uncertain continuous-time Markovian jump linear systems (MJLS) is investigated. The elements in the transition rate matrix include completely known, boundary known, and completely unknown ones. First, the related notions about sliding sector for continuous-time Markov jump linear systems are given; then based on linear matrix inequalities (LMIs) technique, sufficient conditions for the design of the sliding sector are provided. Second, a variable structure control law is presented to guarantee the mean-square quadratic stability of the closed-loop system in spite of the effects of the existing uncertainties and unknown/uncertain transition rates. Finally, an example is given to verify the validity of the theoretical results.
Whispering Gallery Mode Based Optical Fiber Sensor for Measuring Concentration of Salt Solution
Authors: Chiang Chia-Chin , Chao Jian-Cin
Published: November 2013

An optical fiber solution‐concentration sensor based on whispering gallery mode (WGM) is proposed in this paper. The WGM solution‐concentration sensors were used to measure salt solutions, in which the concentrations ranged from 1% to 25% and the wavelength drifted from the left to the right. The experimental results showed an average sensitivity of approximately 0.372 nm/% and an R2 linearity of 0.8835. The proposed WGM sensors are of low cost, feasible for mass production, and durable for solution‐concentration sensing.
An Iteration Scheme Suitable for Solving Limit Cycles of Nonsmooth Dynamical Systems
Authors: Liu Q. X. , Chen Y. M. , Liu J. K.
Published: November 2013

The Mickens iteration method (MIM) is modified to solve self-excited systems containing nonsmooth nonlinearities and/or nonlinear damping terms. If the MIM is implemented routinely, the unknown frequency and amplitude of limit cycle (LC) would couple to each other in complicated nonlinear algebraic equations at each iteration. It is cumbersome to solve these algebraic equations, especially for nonsmooth systems. In the modified procedures, the unknown frequency is substituted by the determined value obtained at the previous iteration. By this means, the frequency is decoupled from the nonlinear terms. Numerical examples show that the LCs obtained by the modified MIM agree well with numerical results. The presented method is very suitable for solving self-excited systems, especially those with nonlinear damping and nonsmooth nonlinearities.
Preparation of BiFeO3‐Graphene Nanocomposites and Their Enhanced Photocatalytic Activities
Authors: Dai J. F. , Xian T. , Di L. J. , Yang H.
Published: November 2013

BiFeO3 nanoparticles were prepared via a polyacrylamide gel route. BiFeO3‐graphene nanocomposites were fabricated by mixing BiFeO3 nanoparticles and graphene into absolute ethanol solution followed by thermal drying. The TEM observation demonstrates that the BiFeO3 nanoparticles are well anchored onto graphene sheets. The photocatalytic activities of the as‐prepared samples were evaluated by the degradation of methyl orange (MO) under simulated sunlight irradiation. Compared to bare BiFeO3 nanoparticles, BiFeO3‐graphene nanocomposites exhibit enhanced photocatalytic activity. The outstanding photocatalytic performance is mainly ascribed to the efficient transfer of photogenerated electrons from BiFeO3 to graphene, thus leading to an increased availability of h+ for the photocatalytic reaction. In addition, hydroxyl (·OH) radicals were detected by the photoluminescence technique using terephthalic acid as a probe molecule and are found to be produced on the irradiated BiFeO3 and BiFeO3‐graphene nanocomposites; in particular, an enhanced yield is observed for the latter.
An Analysis and Design of the Redirection Schema in ForCES
Authors: Gao Ming , Li Shiju , Wang Weiming
Published: November 2013

The idea of Forwarding and Control Element Separation has widely accepted by next generation network researchers, the regain attention of IETF (The Internet Engineering Task Force) ForCES (Forwarding and Control Element Separation) is the best proof. An IP tunnel-based redirection schema was proposed to solve the problem of routing protocol messages interaction between ForCES router and the external merchant routers. The technology of network virtualization is introduced to map network interface from ForCES FE (Forwarding Element) to CE (Control Element) which collaborating with the redirect schema.
TPMS Interference Suppression Based on Beamforming Technology
Authors: Park Cheol , Kim Seong-min , Hwang Suk-seung
Published: November 2013

The Tire Pressure Monitoring System (TPMS) displays the state of a tire on a display to inform a driver of the relevant information, by means of a sensor installed on the tire of the vehicle. When the data measured from the tire are wirelessly transmitted to a receiving antenna located in the center of the vehicle, the exact transmission of data is affected by the interference from various external electronic and electrical devices. In this paper, we suggest a minimum variance distortionless response (MVDR) beamformer based on the angle-of-arrival (AOA) vector for suppressing external interference and receiving accurate data. Although the MVDR beamformer effectively suppresses the interference, it has high computational complexity because of the calculation of an autocorrelation matrix. In order to address this issue, we also suggest a generalized sidelobe canceler (GSC) beamformer which does not have the same performance of the interference suppression to MVDR but also has low computational complexity. Since the signal from each tire can cause interference to others, we consider utilizing a unique Gold Code to each tire to minimize intertire interference and reduce power consumption of a battery installed in each tire.
Spatial Path Following for AUVs Using Adaptive Neural Network Controllers
Authors: Zhou Jiajia , Tang Zhaodong , Zhang Honghan , Jiao Jianfang
Published: November 2013

The spatial path following control problem of autonomous underwater vehicles (AUVs) is addressed in this paper. In order to realize AUVs’ spatial path following control under systemic variations and ocean current, three adaptive neural network controllers which are based on the Lyapunov stability theorem are introduced to estimate uncertain parameters of the vehicle’s model and unknown current disturbances. These controllers are designed to guarantee that all the error states in the path following system are asymptotically stable. Simulation results demonstrated that the proposed controller was effective in reducing the path following error and was robust against the disturbances caused by vehicle's uncertainty and ocean currents.
Study and Testing of Processing Trajectory Measurement Method of Flexible Workpiece
Authors: Deng Yaohua , Chen Sicheng , Li Bingjing , Chen Jiayuan , Wu Liming
Published: November 2013

Flexible workpiece includes the materials like elasticity spline, textile fabric, and polyurethane sponge, due to the fact that processing trajectory is composed by small arc or small line segment primitives and the deformation of the flexible workpiece during the processing trajectory, making the captured image of processing trajectory not clear, the edge of processing image over local uneven gray, and also the pixels of boundaries between the processing trajectory image edge and background organizations not obvious. This paper takes corner search of processing trajectory as the cut-in-point, slope angle curve of starting and terminal point of each primitive is also designed, put forward the search algorithm that regards Daubechies (4) as wavelet operator to conduct slope angle curve for multiple scales wavelet transform, by judging whether there is a point of the curve appears wavelet transform extremum to determine whether the point is a corner point based on wavelet edge modulus maxima extract principle. Finally, proposed a decomposition/reconstruction design method of FIR filters based on wavelet transform of processing image. Eight-tap transpose FIR filter is used to design the decomposition of Daubechies (4) and reconfigurable computing IP core. The IP core wavelet decomposition of the total time-consuming increases only 5.561% in comparsion with PC. Trajectory angle relative error is 2.2%, and the average measurement time is 212.38 ms.
Microseismic Monitoring and Numerical Simulation of Rock Slope Failure
Authors: Liang Zhengzhao , Xu Nuwen , Ma Ke , Tang Shibin , Tang Chunan
Published: November 2013

A numerical code with an elastic-brittle failure model has been developed to simulate the seismic activities in rock failure problems. The feasibility in principle of monitoring and prediction of rock failure was numerically simulated. The heterogeneity was considered to be the main reason for the existence of slope failure precursors. Seismic events could be observed in heterogeneous rock, whereas the homogeneous rocks showed an abrupt fracture mode without any early seismic precursors. The failure process of a slope was numerically investigated by using a gravity increase method (centrifugal loading method), and the application of the microseismic monitoring system in the slope was introduced. The numerical results showed that the fracture of the main faults caused the slope slide, and the microcracking caused by the heterogeneity in the faults prior to the landslide could be considered as the precursors of the slope failure, which were captured by the microseismic monitoring system. The microseismic monitoring technique was proved to be successful in predicting the failure in the slope, and the numerical results will be helpful in interpreting the microseismic monitoring results.