bluuebunny/crossref_metadata_2025_split huggingface dataset:
Digital hypothermia inhibits early lamellar inflammatory signalling in the oligofructose laminitis model
Authors: VAN EPS A. W. , LEISE B. S. , WATTS M. , POLLITT C. C. , BELKNAP J. K. 
Published: September 2011

SummaryReasons for performing study: The pathophysiological events inhibited by prophylactic digital hypothermia that result in reduction of the severity of acute laminitis are unknown.Objectives: To determine if digital hypothermia inhibits lamellar inflammatory signalling during development of oligofructose (OF) induced laminitis.Methods: Fourteen Standardbred horses were given 10 g/kg bwt OF by nasogastric tube with one forelimb (CRYO) continuously cooled by immersion in ice and water and one forelimb (NON‐RX) at ambient temperature. Lamellae were harvested prior to the onset of lameness (24 h post OF administration, DEV group, n = 7) or at the onset of lameness (OG1 group, n = 7). Lamellar mRNA was purified and cDNA produced for real time‐quantitative PCR analysis of mRNA concentrations of cytokines (IL‐6, IL‐1β, IL‐10), chemokines (CXCL1, CXCL6, CXCL8/IL‐8, MCP‐1, MCP‐2), cell adhesion molecules (ICAM‐1, E‐selectin), COX‐2 and 3 housekeeping genes. Data were analysed (NON‐RX vs. CRYO, NON‐RX vs. archived control [CON, n = 7] lamellar tissue) using nonparametric tests.Results: Compared with CON, the OG1 NON‐RX had increased (P<0.05) lamellar mRNA concentrations of all measured mediators except IL‐10, IL‐1β and MCP‐1/2, whereas only CXCL8 was increased (P<0.05) in DEV NON‐RX. Within the OG1 group, CRYO limbs (compared with NON‐RX) had decreased (P<0.05) mRNA concentrations of the majority of measured inflammatory mediators (no change in MCP‐1 and IL‐10). Within the DEV group, mRNA concentrations of CXCL‐1, ICAM‐1, IL‐1β, CXCL8 and MCP‐2 were decreased (P<0.05) and the anti‐inflammatory cytokine IL‐10 was increased (compared with NON‐RX limbs; P<0.05).Conclusions: Digital hypothermia effectively blocked early lamellar inflammatory events likely to play an important role in lamellar injury including the expression of chemokines, proinflammatory cytokines, COX‐2 and endothelial adhesion molecules.Potential relevance: This study demonstrates a potential mechanism by which hypothermia reduces the severity of acute laminitis, and may help identify molecular targets for future laminitis intervention.
Effects of acute exercise on angiotensin I‐converting enzyme (ACE) activity in horses
Authors: DE MELLO COSTA M. F. , ANDERSON G. A. , DAVIES H. M. , SLOCOMBE R. F. 
Published: September 2011

SummaryAngiotensin I‐converting enzyme (ACE) level measurement in blood samples is an important tool in human medicine for the detection, treatment and control of diseases such as sarcoidosis and hypertension. Recently ACE has been advocated as being correlated to athletic aptitude in human athletes and a genetic polymorphism has been shown to be responsible for the enzymatic levels in the circulation. The objective of this research was to evaluate the effects of acute exercise in horses in order to increase the understanding of a possible correlation between ACE levels in plasma and performance in equine athletes. A standardised exercise test (SET) to fatigue was conducted on 8 horses and repeated venous blood collections carried out for ACE activity measurements before, during and after the SET. Our results show an increase in ACE activity up to fatigue and a return to baseline values at 30 min post exercise.
Cognitive correlates of performance in advanced mathematics
Authors: Wei Wei , Yuan Hongbo , Chen Chuansheng , Zhou Xinlin 
Published: September 2011

Background. Much research has been devoted to understanding cognitive correlates of elementary mathematics performance, but little such research has been done for advanced mathematics (e.g., modern algebra, statistics, and mathematical logic).Aims. To promote mathematical knowledge among college students, it is necessary to understand what factors (including cognitive factors) are important for acquiring advanced mathematics.Samples. We recruited 80 undergraduates from four universities in Beijing.Methods. The current study investigated the associations between students’ performance on a test of advanced mathematics and a battery of 17 cognitive tasks on basic numerical processing, complex numerical processing, spatial abilities, language abilities, and general cognitive processing.Results. The results showed that spatial abilities were significantly correlated with performance in advanced mathematics after controlling for other factors. In addition, certain language abilities (i.e., comprehension of words and sentences) also made unique contributions. In contrast, basic numerical processing and computation were generally not correlated with performance in advanced mathematics.Conclusions. Results suggest that spatial abilities and language comprehension, but not basic numerical processing, may play an important role in advanced mathematics. These results are discussed in terms of their theoretical significance and practical implications.
Standards Meetings Calendar–National
Authors: Blaeser Susan B. , Schomer Paul D. 
Published: September 2011

American National Standards (ANSI Standards) developed by Accredited Standards Committees S1, S2, S3, and S12 in the areas of acoustics, mechanical vibration and shock, bioacoustics, and noise, respectively, are published by the Acoustical Society of America (ASA). In addition to these standards, ASA publishes catalogs of Acoustical Standards, both National and International. To receive copies of the latest Standards Catalogs, please contact Susan B. Blaeser.
Comments are welcomed on all material in Acoustical Standards News.
This Acoustical Standards News section in JASA, as well as the National and International Catalogs of Acoustical Standards, and other information on the Standards Program of the Acoustical Society of America, are available via the ASA home page: http://acousticalsociety.org.
Barcoded Primers Used in Multiplex Amplicon Pyrosequencing Bias Amplification
Authors: Berry David , Ben Mahfoudh Karim , Wagner Michael , Loy Alexander 
Published: September 2011

ABSTRACT
“Barcode-tagged” PCR primers used for multiplex amplicon sequencing generate a thus-far-overlooked amplification bias that produces variable terminal restriction fragment length polymorphism (T-RFLP) and pyrosequencing data from the same environmental DNA template. We propose a simple two-step PCR approach that increases reproducibility and consistently recovers higher genetic diversity in pyrosequencing libraries.
Selective Utilization of Exogenous Amino Acids by Dehalococcoides ethenogenes Strain 195 and Its Effects on Growth and Dechlorination Activity
Authors: Zhuang Wei-Qin , Yi Shan , Feng Xueyang , Zinder Stephen H. , Tang Yinjie J. , Alvarez-Cohen Lisa 
Published: September 2011

ABSTRACTBacteria of the genusDehalococcoidesare important members of bioremediation communities because of their ability to detoxify chloroethenes to the benign end product ethene. Genome-enabled studies conducted withDehalococcoides ethenogenes195 have revealed that two ATP-binding cassette (ABC)-type amino acid transporters are expressed during its exponential growth stages. In light of previous findings that Casamino Acids enhanced its dechlorination activity, we hypothesized that strain 195 is capable of importing amino acids from its environment to facilitate dechlorination and growth. To test this hypothesis, we applied isotopomer-based dilution analysis with13C-labeled acetate to differentiate the amino acids that were taken up by strain 195 from those synthesizedde novoand to determine the physiological changes caused by the significantly incorporated amino acids. Our results showed that glutamate/glutamine and aspartate/asparagine were almost exclusively synthesized by strain 195, even when provided in excess in the medium. In contrast, phenylalanine, isoleucine, leucine, and methionine were identified as the four most highly incorporated amino acids, at levels >30% of respective proteinogenic amino acids. When either phenylalanine or all four highly incorporated amino acids were added to the defined mineral medium, the growth rates, dechlorination activities, and yields of strain 195 were enhanced to levels similar to those observed with supplementation with 20 amino acids. However, genes for the putative ABC-type amino acids transporters and phenylalanine biosynthesis exhibited insignificant regulation in response to the imported amino acids. This study also demonstrates that using isotopomer-based metabolite analysis can be an efficient strategy for optimizing nutritional conditions for slow-growing microorganisms.
Rapid, Transient, and Proportional Activation of σ
B
in Response to Osmotic Stress in Listeria monocytogenes
Authors: Utratna Marta , Shaw Iain , Starr Emily , O'Byrne Conor P. 
Published: September 2011

ABSTRACT

The osmotic activation of sigma B (σ
B
) in
Listeria monocytogenes
was studied by monitoring expression of four known σ
B
-dependent genes,
opuCA
,
lmo2230
,
lmo2085
, and
sigB
. Activation was found to be rapid, transient, and proportional to the magnitude of the osmotic stress applied, features that underpin the adaptability of this pathogen.
Functional Analyses of Multiple Lichenin-Degrading Enzymes from the Rumen Bacterium Ruminococcus albus 8
Authors: Iakiviak Michael , Mackie Roderick I. , Cann Isaac K. O. 
Published: September 2011

ABSTRACT

Ruminococcus albus
8 is a fibrolytic ruminal bacterium capable of utilization of various plant cell wall polysaccharides. A bioinformatic analysis of a partial genome sequence of
R. albus
revealed several putative enzymes likely to hydrolyze glucans, including lichenin, a mixed-linkage polysaccharide of glucose linked together in β-1,3 and β-1,4 glycosidic bonds. In the present study, we demonstrate the capacity of four glycoside hydrolases (GHs), derived from
R. albus
, to hydrolyze lichenin. Two of the genes encoded GH family 5 enzymes (Ra0453 and Ra2830), one gene encoded a GH family 16 enzyme (Ra0505), and the last gene encoded a GH family 3 enzyme (Ra1595). Each gene was expressed in
Escherichia coli
, and the recombinant protein was purified to near homogeneity. Upon screening on a wide range of substrates, Ra0453, Ra2830, and Ra0505 displayed different hydrolytic properties, as they released unique product profiles. The Ra1595 protein, predicted to function as a β-glucosidase, preferred cleavage of a nonreducing end glucose when linked by a β-1,3 glycosidic bond to the next glucose residue. The major product of Ra0505 hydrolysis of lichenin was predicted to be a glucotriose that was degraded only by Ra0453 to glucose and cellobiose. Most importantly, the four enzymes functioned synergistically to hydrolyze lichenin to glucose, cellobiose, and cellotriose. This lichenin-degrading enzyme mix should be of utility as an additive to feeds administered to monogastric animals, especially those high in fiber.
Effect of Genetically Modified Poplars on Soil Microbial Communities during the Phytoremediation of Waste Mine Tailings
Authors: Hur Moonsuk , Kim Yongho , Song Hae-Ryong , Kim Jong Min , Choi Young Im , Yi Hana 
Published: September 2011

ABSTRACT
The application of transgenic plants to clean up environmental pollution caused by the wastes of heavy metal mining is a promising method for removing metal pollutants from soils. However, the effect of using genetically modified organisms for phytoremediation is a poorly researched topic in terms of microbial community structures, despite the important role of microorganisms in the health of soil. In this study, a comparative analysis of the bacterial and archaeal communities found in the rhizosphere of genetically modified (GM) versus wild-type (WT) poplar was conducted on trees at different growth stages (i.e., the rhizospheres of 1.5-, 2.5-, and 3-year-old poplars) that were cultivated on contaminated soils together with nonplanted control soil. Based on the results of DNA pyrosequencing, poplar type and growth stages were associated with directional changes in the structure of the microbial community. The rate of change was faster in GM poplars than in WT poplars, but the microbial communities were identical in the 3-year-old poplars. This phenomenon may arise because of a higher rate and greater extent of metal accumulation in GM poplars than in naturally occurring plants, which resulted in greater changes in soil environments and hence the microbial habitat.
Detection of Enterotoxigenic Clostridium perfringens in Meat Samples by Using Molecular Methods
Authors: Kaneko Ikuko , Miyamoto Kazuaki , Mimura Kanako , Yumine Natsuko , Utsunomiya Hirotoshi , Akimoto Shigeru , McClane Bruce A. 
Published: September 2011

ABSTRACTTo prevent food-borne bacterial diseases and to trace bacterial contamination events to foods, microbial source tracking (MST) methods provide important epidemiological information. To apply molecular methods to MST, it is necessary not only to amplify bacterial cells to detection limit levels but also to prepare DNA with reduced inhibitory compounds and contamination. Isolates carrying theClostridium perfringensenterotoxin gene (cpe) on the chromosome or a plasmid rank among the most important food-borne pathogens. Previous surveys indicated thatcpe-positiveC. perfringensisolates are present in only ∼5% of nonoutbreak food samples and then only at low numbers, usually less than 3 cells/g. In this study, four molecular assays for the detection ofcpe-positiveC. perfringensisolates, i.e., ordinary PCR, nested PCR, real-time PCR, and loop-mediated isothermal amplification (LAMP), were developed and evaluated for their reliability using purified DNA. For use in the artificial contamination of meat samples, DNA templates were prepared by three different commercial DNA preparation kits. The four molecular assays always detectedcpewhen >103cells/g ofcpe-positiveC. perfringenswere present, using any kit. Of three tested commercial DNA preparation kits, the InstaGene matrix kit appeared to be most suitable for the testing of a large number of samples. By using the InstaGene matrix kit, the four molecular assays efficiently detectedcpeusing DNA prepared from enrichment culture specimens of meat samples contaminated with low numbers ofcpe-positiveC. perfringensvegetative cells or spores. Overall, the current study developed molecular assay protocols for MST to detect the contamination of foods with low numbers of cells, and at a low frequency, ofcpe-positiveC. perfringensisolates.
Evolutionary Dynamics of Candida albicans during
In Vitro
Evolution
Authors: Huang Mian , McClellan Mark , Berman Judith , Kao Katy C. 
Published: September 2011

ABSTRACT

While mechanisms of resistance to major antifungal agents have been characterized in
Candida albicans
, little is known about the evolutionary trajectories during the emergence of drug resistance. Here, we examined the evolutionary dynamics of
C. albicans
that evolved
in vitro
in the presence or absence of fluconazole using the visualizing evolution in real-time (VERT) method, a novel experimental approach that facilitates the systematic isolation of adaptive mutants that arise in the population. We found an increase in the frequency of adaptive events in the presence of fluconazole compared to the no-drug controls. Analysis of the evolutionary dynamics revealed that mutations that led to increased drug resistance appeared frequently and that mutants with increased levels of resistance arose in independent lineages. Interestingly, most adaptive mutants with increased fitness in the presence of the drug did not exhibit a significant fitness decrease in the absence of the drug, supporting the idea that rapid resistance can arise from mutations in strains maintained in the population prior to exposure to the drug.
The Surfactant of Legionella pneumophila Is Secreted in a TolC-Dependent Manner and Is Antagonistic toward Other Legionella Species
Authors: Stewart Catherine R. , Burnside Denise M. , Cianciotto Nicholas P. 
Published: September 2011

ABSTRACT

When
Legionella pneumophila
grows on agar plates, it secretes a surfactant that promotes flagellum- and pilus-independent “sliding” motility. We isolated three mutants that were defective for surfactant. The first two had mutations in genes predicted to encode cytoplasmic enzymes involved in lipid metabolism. These genes mapped to two adjacent operons that we designated
bbcABCDEF
and
bbcGHIJK
. Backcrossing and complementation confirmed the importance of the
bbc
genes and suggested that the
Legionella
surfactant is lipid containing. The third mutant had an insertion in
tolC
. TolC is the outer membrane part of various trimolecular complexes involved in multidrug efflux and type I protein secretion. Complementation of the
tolC
mutant restored sliding motility. Mutants defective for an inner membrane partner of TolC also lacked a surfactant, confirming that TolC promotes surfactant secretion.
L. pneumophila
(
lspF
) mutants lacking type II protein secretion (T2S) are also impaired for a surfactant. When the
tolC
and
lspF
mutants were grown next to each other, the
lsp
mutant secreted surfactant, suggesting that TolC and T2S conjoin to mediate surfactant secretion, with one being the conduit for surfactant export and the other the exporter of a molecule that is required for induction or maturation of surfactant synthesis/secretion. Although the surfactant was not required for the extracellular growth, intracellular infection, and intrapulmonary survival of
L. pneumophila
, it exhibited antimicrobial activity toward seven other species of
Legionella
but not toward various non-
Legionella
species. These data suggest that the surfactant provides
L. pneumophila
with a selective advantage over other legionellae in the natural environment.
Phage-Borne Factors and Host LexA Regulate the Lytic Switch in Phage GIL01
Authors: Fornelos Nadine , Bamford Jaana K. H. , Mahillon Jacques 
Published: September 2011

ABSTRACT

The
Bacillus thuringiensis
temperate phage GIL01 does not integrate into the host chromosome but exists stably as an independent linear replicon within the cell. Similar to that of the lambdoid prophages, the lytic cycle of GIL01 is induced as part of the cellular SOS response to DNA damage. However, no CI-like maintenance repressor has been detected in the phage genome, suggesting that GIL01 uses a novel mechanism to maintain lysogeny. To gain insights into the GIL01 regulatory circuit, we isolated and characterized a set of 17 clear plaque (
cp
) mutants that are unable to lysogenize. Two phage-encoded proteins, gp1 and gp7, are required for stable lysogen formation. Analysis of
cp
mutants also identified a 14-bp palindromic
dinBox
1 sequence within the
P1
-
P2
promoter region that resembles the known LexA-binding site of Gram-positive bacteria. Mutations at conserved positions in
dinBox
1 result in a
cp
phenotype. Genomic analysis identified a total of three
dinBox
sites within GIL01 promoter regions. To investigate the possibility that the host LexA regulates GIL01, phage induction was measured in a host carrying a noncleavable
lexA
(Ind
−
) mutation. GIL01 formed stable lysogens in this host, but lytic growth could not be induced by treatment with mitomycin C. Also, mitomycin C induced β-galactosidase expression from GIL01-
lacZ
promoter fusions, and induction was similarly blocked in the
lexA
(Ind
−
) mutant host. These data support a model in which host LexA binds to
dinBox
sequences in GIL01, repressing phage gene expression during lysogeny and providing the switch necessary to enter lytic development.
An ATP-Grasp Ligase Involved in the Last Biosynthetic Step of the Iminomycosporine Shinorine in Nostoc punctiforme ATCC 29133
Authors: Gao Qunjie , Garcia-Pichel Ferran 
Published: September 2011

ABSTRACT

We investigated the genetic basis for mycosporine sunscreen biosynthesis by the cyanobacterium
Nostoc punctiforme
ATCC 29133. Heterologous expression in
Escherichia coli
of three contiguous
N. punctiforme
genes (NpR5600, NpR5599, and NpR5598, here named
mys
A
,
mys
B
, and
mys
C
, respectively) led to the production of mycosporine-glycine, an oxomycosporine. Additional expression of gene NpF5597 (
mys
D
) led to the conversion of mycosporine-glycine into iminomycosporines (preferentially shinorine but also others like mycosporine-2-glycine and porphyra-334). This represents a new mode of enzymatic synthesis for iminomycosporines, one that differs in genetic origin, mechanism, and apparent substrate specificity from that known in
Anabaena variabilis
ATCC 29413. These results add to the emerging profile of the protein family of ATP-dependent ligases, to which the
mys
C
product belongs, as important condensation enzymes in microbial secondary metabolism.
Modulation of Substrate Efflux in Bacterial Small Multidrug Resistance Proteins by Mutations at the Dimer Interface
Authors: Poulsen Bradley E. , Cunningham Fiona , Lee Kate K. Y. , Deber Charles M. 
Published: September 2011

ABSTRACT

Bacteria evade the effects of cytotoxic compounds through the efflux activity of membrane-bound transporters such as the small multidrug resistance (SMR) proteins. Consisting typically of ca. 110 residues with four transmembrane (TM) α-helices, crystallographic studies have shown that TM helix 1 (TM1) through TM helix 3 (TM3) of each monomer create a substrate binding “pocket” within the membrane bilayer, while a TM4-TM4 interaction accounts for the primary dimer formation. Previous work from our lab has characterized a highly conserved small-residue heptad motif in the
Halobacterium salinarum
transporter Hsmr as
90
GLXLIXXGV
98
that lies along the TM4-TM4 dimer interface of SMR proteins as required for function. Focusing on conserved positions 91, 93, 94, and 98, we substituted the naturally occurring Hsmr residue for Ala, Phe, Ile, Leu, Met, and Val at each position in the Hsmr TM4-TM4 interface. Large-residue replacements were studied for their ability to dimerize on SDS-polyacrylamide gels, to bind the cytotoxic compound ethidium bromide, and to confer resistance by efflux. Although the relative activity of mutants did not correlate with dimer strength for all mutants, all functional mutants lay within 10% of dimerization relative to the wild type (WT), suggesting that the optimal dimer strength at TM4 is required for proper efflux. Furthermore, nonfunctional substitutions at the center of the dimerization interface that do not alter dimer strength suggest a dynamic TM4-TM4 “pivot point” that responds to the efflux requirements of different substrates. This functionally critical region represents a potential target for inhibiting the ability of bacteria to evade the effects of cytotoxic compounds.