bluuebunny/crossref_metadata_2025 huggingface dataset:
Microbial Diversity in Anaerobic Sediments at Río Tinto, a Naturally Acidic Environment with a High Heavy Metal Content
Authors: Sánchez-Andrea Irene , Rodríguez Nuria , Amils Ricardo , Sanz José Luis
Published: July 2011

The Tinto River is an extreme environment located at the core of the Iberian Pyritic Belt (IPB). It is an unusual ecosystem due to its size (100 km long), constant acidic pH (mean pH, 2.3), and high concentration of heavy metals, iron, and sulfate in its waters, characteristics that make the Tinto River Basin comparable to acidic mine drainage (AMD) systems. In this paper we present an extensive survey of the Tinto River sediment microbiota using two culture-independent approaches: denaturing gradient gel electrophoresis and cloning of 16S rRNA genes. The taxonomic affiliation of the
Bacteria
showed a high degree of biodiversity, falling into 5 different phyla:
Proteobacteria
,
Firmicutes
,
Bacteroidetes
,
Acidobacteria
, and
Actinobacteria
; meanwhile, all the
Archaea
were affiliated with the order
Thermoplasmatales
. Microorganisms involved in the iron (
Acidithiobacillus ferrooxidans
,
Sulfobacillus
spp.,
Ferroplasma
spp., etc.), sulfur (
Desulfurella
spp.,
Desulfosporosinus
spp.,
Thermodesulfobium
spp., etc.), and carbon (
Acidiphilium
spp.,
Bacillus
spp.,
Clostridium
spp.,
Acidobacterium
spp., etc.) cycles were identified, and their distribution was correlated with physicochemical parameters of the sediments. Ferric iron was the main electron acceptor for the oxidation of organic matter in the most acid and oxidizing layers, so acidophilic facultative Fe(III)-reducing bacteria appeared widely in the clone libraries. With increasing pH, the solubility of iron decreases and sulfate-reducing bacteria become dominant, with the ecological role of methanogens being insignificant. Considering the identified microorganisms—which, according to the rarefaction curves and Good's coverage values, cover almost all of the diversity—and their corresponding metabolism, we suggest a model of the iron, sulfur, and organic matter cycles in AMD-related sediments.
Evidence of Autoinduction Heterogeneity via Expression of the Agr System of Listeria monocytogenes at the Single-Cell Level
Authors: Garmyn Dominique , Gal Laurent , Briandet Romain , Guilbaud Morgan , Lemaître Jean-Paul , Hartmann Alain , Piveteau Pascal
Published: July 2011

To investigate if the primary function of the Agr system of
Listeria monocytogenes
is to monitor cell density, we followed Agr expression in batch cultures, in which the autoinducer concentration was uniform, and in biofilms. Expression was heterogeneous, suggesting that the primary function of Agr is not to monitor population density.
Prevalence and Genotypic Characteristics of Clostridium difficile in a Closed and Integrated Human and Swine Population
Authors: Norman Keri N. , Scott H. Morgan , Harvey Roger B. , Norby Bo , Hume Michael E. , Andrews Kathleen
Published: July 2011

Recently, an apparent rise in the number of cases attributed to community-acquired
Clostridium difficile
infection has led researchers to explore additional sources of infection. The finding of
C. difficile
in food animals and retail meat has raised concern about potential food-borne and occupational exposures. The objective of this study was to compare
C. difficile
isolated from a closed population of healthy individuals consisting of both humans and swine in order to investigate possible food safety and occupational risks for exposure. Using a multistep enrichment isolation technique, we identified 11.8% of the human wastewater samples and 8.6% of the swine samples that were positive for
C. difficile
. The prevalences of
C. difficile
in swine production groups differed significantly (
P
< 0.05); however, the prevalences in the two human occupational group cohorts did not differ significantly (
P
= 0.81). The majority of the human and swine isolates were similar based on multiple typing methods. The similarity in
C. difficile
prevalence in the human group cohorts suggests a low occupational hazard, while a greatly decreased prevalence of
C. difficile
in later-stage swine production groups suggests a diminished risk for food-borne exposure. The similarity of strains in the two host species suggests the possibility of a common environmental source for healthy individuals in a community setting.
Detection, Isolation, and Characterization of Acidophilic Methanotrophs from Sphagnum Mosses
Authors: Kip Nardy , Ouyang Wenjing , van Winden Julia , Raghoebarsing Ashna , van Niftrik Laura , Pol Arjan , Pan Yao , Bodrossy Levente , van Donselaar Elly G. , Reichart Gert-Jan , Jetten Mike S. M. , Sinninghe Damsté Jaap S. , Op den Camp Huub J. M.
Published: July 2011

Sphagnum
peatlands are important ecosystems in the methane cycle. Methane-oxidizing bacteria in these ecosystems serve as a methane filter and limit methane emissions. Yet little is known about the diversity and identity of the methanotrophs present in and on
Sphagnum
mosses of peatlands, and only a few isolates are known. The methanotrophic community in
Sphagnum
mosses, originating from a Dutch peat bog, was investigated using a
pmoA
microarray. A high biodiversity of both gamma- and alphaproteobacterial methanotrophs was found. With
Sphagnum
mosses as the inoculum, alpha- and gammaproteobacterial acidophilic methanotrophs were isolated using established and newly designed media. The 16S rRNA,
pmoA
,
pxmA
, and
mmoX
gene sequences showed that the alphaproteobacterial isolates belonged to the
Methylocystis
and
Methylosinus
genera. The
Methylosinus
species isolated are the first acid-tolerant members of this genus. Of the acidophilic gammaproteobacterial strains isolated, strain M5 was affiliated with the
Methylomonas
genus, and the other strain, M200, may represent a novel genus, most closely related to the genera
Methylosoma
and
Methylovulum
. So far, no acidophilic or acid-tolerant methanotrophs in the
Gammaproteobacteria
class are known. All strains showed the typical features of either type I or II methanotrophs and are, to the best of our knowledge, the first isolated (acidophilic or acid-tolerant) methanotrophs from
Sphagnum
mosses.
Gpd1 and Gpd2 Fine-Tuning for Sustainable Reduction of Glycerol Formation in Saccharomyces cerevisiae
Authors: Hubmann Georg , Guillouet Stephane , Nevoigt Elke
Published: July 2011

Gpd1 and Gpd2 are the two isoforms of glycerol 3-phosphate dehydrogenase (GPDH), which is the rate-controlling enzyme of glycerol formation in
Saccharomyces cerevisiae.
The two isoenzymes play crucial roles in osmoregulation and redox balancing. Past approaches to increase ethanol yield at the cost of reduced glycerol yield have most often been based on deletion of either one or two isogenes (
GPD1
and
GPD2
). While single deletions of
GPD1
or
GPD2
reduced glycerol formation only slightly, the
gpd1
Δ
gpd2
Δ double deletion strain produced zero glycerol but showed an osmosensitive phenotype and abolished anaerobic growth. Our current approach has sought to generate “intermediate” phenotypes by reducing both isoenzyme activities without abolishing them. To this end, the
GPD1
promoter was replaced in a
gpd2
Δ background by two lower-strength
TEF1
promoter mutants. In the same manner, the activity of the
GPD2
promoter was reduced in a
gpd1Δ
background. The resulting strains were crossed to obtain different combinations of residual
GPD1
and
GPD2
expression levels. Among our engineered strains we identified four candidates showing improved ethanol yields compared to the wild type. In contrast to a
gpd1
Δ
gpd2
Δ double-deletion strain, these strains were able to completely ferment the sugars under quasi-anaerobic conditions in both minimal medium and during simultaneous saccharification and fermentation (SSF) of liquefied wheat mash (wheat liquefact). This result implies that our strains can tolerate the ethanol concentration at the end of the wheat liquefact SSF (up to 90 g liter
−1
). Moreover, a few of these strains showed no significant reduction in osmotic stress tolerance compared to the wild type.
A Genomewide Screen for Tolerance to Cationic Drugs Reveals Genes Important for Potassium Homeostasis in Saccharomyces cerevisiae
Authors: Barreto Lina , Canadell David , Petrezsélyová Silvia , Navarrete Clara , Marešová Lydie , Peréz-Valle Jorge , Herrera Rito , Olier Iván , Giraldo Jesús , Sychrová Hana , Yenush Lynne , Ramos José , Ariño Joaquín
Published: July 2011

Potassium homeostasis is crucial for living cells. In the yeast
Saccharomyces cerevisiae
, the uptake of potassium is driven by the electrochemical gradient generated by the Pma1 H
+
-ATPase, and this process represents a major consumer of the gradient. We considered that any mutation resulting in an alteration of the electrochemical gradient could give rise to anomalous sensitivity to any cationic drug independently of its toxicity mechanism. Here, we describe a genomewide screen for mutants that present altered tolerance to hygromycin B, spermine, and tetramethylammonium. Two hundred twenty-six mutant strains displayed altered tolerance to all three drugs (202 hypersensitive and 24 hypertolerant), and more than 50% presented a strong or moderate growth defect at a limiting potassium concentration (1 mM). Functional groups such as protein kinases and phosphatases, intracellular trafficking, transcription, or cell cycle and DNA processing were enriched. Essentially, our screen has identified a substantial number of genes that were not previously described to play a direct or indirect role in potassium homeostasis. A subset of 27 representative mutants were selected and subjected to diverse biochemical tests that, in some cases, allowed us to postulate the basis for the observed phenotypes.
RNA Interference in Fungi: Pathways, Functions, and Applications
Authors: Dang Yunkun , Yang Qiuying , Xue Zhihong , Liu Yi
Published: July 2011

Small RNA molecules of about 20 to 30 nucleotides function in gene regulation and genomic defense via conserved eukaryotic RNA interference (RNAi)-related pathways. The RNAi machinery consists of three core components: Dicer, Argonaute, and RNA-dependent RNA polymerase. In fungi, the RNAi-related pathways have three major functions: genomic defense, heterochromatin formation, and gene regulation. Studies of
Schizosaccharomyces pombe
and
Neurospora
, and other fungi have uncovered surprisingly diverse small RNA biogenesis pathways, suggesting that fungi utilize RNAi-related pathways in various cellular processes to adapt to different environmental conditions. These studies also provided important insights into how RNAi functions in eukaryotic systems in general. In this review, we will discuss our current understanding of the fungal RNAi-related pathways and their functions, with a focus on filamentous fungi. We will also discuss how RNAi can be used as a tool in fungal research.
Polycyclic Aromatic Hydrocarbon Metabolic Network in Mycobacterium vanbaaleniiPYR-1
Authors: Kweon Ohgew , Kim Seong-Jae , Holland Ricky D. , Chen Hongyan , Kim Dae-Wi , Gao Yuan , Yu Li-Rong , Baek Songjoon , Baek Dong-Heon , Ahn Hongsik , Cerniglia Carl E.
Published: July 2011

This study investigated a metabolic network (MN) from
Mycobacterium vanbaalenii
PYR-1 for polycyclic aromatic hydrocarbons (PAHs) from the perspective of structure, behavior, and evolution, in which multilayer omics data are integrated. Initially, we utilized a high-throughput proteomic analysis to assess the protein expression response of
M. vanbaalenii
PYR-1 to seven different aromatic compounds. A total of 3,431 proteins (57.38% of the genome-predicted proteins) were identified, which included 160 proteins that seemed to be involved in the degradation of aromatic hydrocarbons. Based on the proteomic data and the previous metabolic, biochemical, physiological, and genomic information, we reconstructed an experiment-based system-level PAH-MN. The structure of PAH-MN, with 183 metabolic compounds and 224 chemical reactions, has a typical scale-free nature. The behavior and evolution of the PAH-MN reveals a hierarchical modularity with funnel effects in structure/function and intimate association with evolutionary modules of the functional modules, which are the ring cleavage process (RCP), side chain process (SCP), and central aromatic process (CAP). The 189 commonly upregulated proteins in all aromatic hydrocarbon treatments provide insights into the global adaptation to facilitate the PAH metabolism. Taken together, the findings of our study provide the hierarchical viewpoint from genes/proteins/metabolites to the network via functional modules of the PAH-MN equipped with the engineering-driven approaches of modularization and rationalization, which may expand our understanding of the metabolic potential of
M. vanbaalenii
PYR-1 for bioremediation applications.
Activity and Transcriptional Regulation of Bacterial Protein-Like Glycerol-3-Phosphate Dehydrogenase of the Haloarchaea in Haloferax volcanii
Authors: Rawls Katherine S. , Martin Jonathan H. , Maupin-Furlow Julie A.
Published: July 2011

Glycerol is a primary energy source for heterotrophic haloarchaea and a major component of “salty” biodiesel waste. Glycerol is catabolized solely by glycerol kinase (encoded by
glpK
) to glycerol-3-phosphate (G3P) in
Haloferax volcanii
. Here we characterized the next critical step of this metabolic pathway: the conversion of G3P to dihydroxyacetone phosphate by G3P dehydrogenase (G3PDH).
H. volcanii
harbors two putative G3PDH operons: (i)
glpA1B1C1
, located on the chromosome within the neighborhood of
glpK
, and (ii)
glpA2B2C2
, on megaplasmid pHV4. Analysis of knockout strains revealed that
glpA1
(and not
glpA2
) is required for growth on glycerol. However, both
glpA1
and
glpA2
could complement a
glpA1
knockout strain (when expressed from a strong promoter in
trans
) and were required for the total G3PDH activity of cell lysates. The
glpA1B1C1
,
glpK
,
glpF
(encoding a putative glycerol facilitator), and
ptsH2
(encoding a homolog of the bacterial phosphotransferase system protein Hpr) genes were transcriptionally linked and appeared to be under the control of a strong, G3P-inducible promoter upstream of
glpA1
. Overall, this study provides fundamental insights into glycerol metabolism in
H. volcanii
and enhances our understanding of central metabolic pathways of haloarchaea.
The Sulfolobicin Genes of Sulfolobus acidocaldariusEncode Novel Antimicrobial Proteins
Authors: Ellen Albert F. , Rohulya Olha V. , Fusetti Fabrizia , Wagner Michaela , Albers Sonja-Verena , Driessen Arnold J. M.
Published: July 2011

Crenarchaea, such as
Sulfolobus acidocaldarius
and
Sulfolobus tokodaii
, produce antimicrobial proteins called sulfolobicins. These antimicrobial proteins inhibit the growth of closely related species. Here we report the identification of the sulfolobicin-encoding genes in
S. acidocaldarius
. The active sulfolobicin comprises two proteins that are equipped with a classical signal sequence. These proteins are secreted by the cells and found to be membrane vesicle associated. Gene inactivation studies demonstrate that both proteins are required for the bacteriostatic antimicrobial activity. Sulfolobicins constitute a novel class of antimicrobial proteins without detectable homology to any other protein.
Genome Sequence of the Arctic Methanotroph Methylobacter tundripaludum SV96
Authors: Svenning Mette M. , Hestnes Anne Grethe , Wartiainen Ingvild , Stein Lisa Y. , Klotz Martin G. , Kalyuzhnaya Marina G. , Spang Anja , Bringel Françoise , Vuilleumier Stéphane , Lajus Aurélie , Médigue Claudine , Bruce David C. , Cheng Jan-Fang , Goodwin Lynne , Ivanova Natalia , Han James , Han Cliff S. , Hauser Loren , Held Brittany , Land Miriam L. , Lapidus Alla , Lucas Susan , Nolan Matt , Pitluck Sam , Woyke Tanja
Published: July 2011

Methylobacter tundripaludum
SV96
T
(ATCC BAA-1195) is a psychrotolerant aerobic methane-oxidizing gammaproteobacterium (
Methylococcales
,
Methylococcaceae
) living in High Arctic wetland soil. The strain was isolated from soil harvested in July 1996 close to the settlement Ny-Ålesund, Svalbard, Norway (78°56′N, 11°53′E), and described as a novel species in 2006. The genome includes
pmo
and
pxm
operons encoding copper membrane monooxygenases (Cu-MMOs), genes required for nitrogen fixation, and the
nirS
gene implicated in dissimilatory nitrite reduction to NO but no identifiable inventory for further processing of nitrogen oxides. These genome data provide the basis to investigate
M. tundripaludum
SV96, identified as a major player in the biogeochemistry of Arctic environments.
Draft Genome Sequence of the Novel Agar-Digesting Marine Bacterium HQM9
Authors: Du Zongjun , Zhang Zhewen , Miao Tingting , Wu Jiayan , Lü Guoqiang , Yu Jun , Xiao Jingfa , Chen Guanjun
Published: July 2011

Strain HQM9, an aerobic, rod-shaped marine bacterium from red algae, can produce agarases and liquefy solid plating media efficiently when agar is used as a coagulant. Here we report the draft genome sequence and the initial findings from a preliminary analysis of strain HQM9, which should be a novel species of
Flavobacteriaceae
.
Spatial orientation of the subtalar joint axis is different in subjects with and without Achilles tendon disorders
Authors: Reule Claudia A , Alt Wilfried W , Lohrer Heinz , Hochwald Harald
Published: July 2011

Background

There are many possible predisposing factors for Achilles tendon disorders suggested in the literature but their pathogenetic relevance is not proven in most cases. The asymmetric mechanical load distribution within the Achilles tendon during locomotion is frequently addressed as a major risk factor for Achilles tendon disorders. The spatial orientation of the subtalar joint axis (STA) may influence the Achilles tendon loading possibly leading to overload injuries.

Hypothesis

There is a significant difference between the orientation of the STA in subjects with and without Achilles tendon pathologies.

Materials and methods

614 subtalar joint axes determined in 307 long-distance runners with and without Achilles tendon disorders were included. Achilles tendon disorders were defined as any Achilles tendon–related pain during or following running, existing for more than 2 weeks in the past. Motion analysis of the foot was performed using an ultrasonic pulse-echo-based measurement system. The orientation of the STA was expressed by two angles.

Results

The mean inclination angle was 42±16° and the mean deviation angle was 11±23°. There was a significant difference (p=0.002) between the mean deviation angle measured in subjects with Achilles tendon pathologies (18±23°) and those without (10±23°).

Conclusions

The results demonstrate a wide interindividual variability of the spatial orientation of the STA. In addition, the mean deviation angle in people with Achilles tendon pathologies is significantly more oblique than in people without. This finding indicates that the spatial orientation of the STA is related to the incidence of overuse injuries of the Achilles tendon in the investigated sample.
Reduced expression of desmocollin 2 is an independent prognostic biomarker for shorter patients survival in pancreatic ductal adenocarcinoma
Authors: Hamidov Zaur , Altendorf-Hofmann Annelore , Chen Yuan , Settmacher Utz , Petersen Iver , Knösel Thomas
Published: July 2011

Background

Cell–cell adhesion molecules such as desmosomes and cytokeratins may play a major role in epithelial–mesenchymal transition and have been suggested to have a relevant impact on tumour progression. This study investigated 15 biomarkers in pancreatic ductal adenocarcinoma (PDAC) and correlated the results with clinicopathological parameters.

Methods

Tissue microarrays of 115 R0-resected PDAC were constructed to evaluate the protein expression of 15 in genome‐wide expression profiling differentially expressed biomarkers.

Results

At the protein level a high expression of desmocollin 2 (DSC2) was observed in 90.4%, DSC1 (67.6%), DSC3 (0.9%), MDM2 (16.2%), CEA (64.8%), CK7 (85.2%), CK8 (96.5%), CK18 (96.5%), CK19 (93.9%), CK20 (11.5%), CA19-9 (86.6%), TLE1 (8.7%), PITX1 (91.2%), factor H (95.7%) and mesothelin (9.6%). Reduced expression of DSC2 was statistically correlated with shorter patient survival, higher tumour grading and positive lymph node status (p=0.008, p=0.029, p=0.011, respectively). In multivariable analysis reduced expression of DSC2, higher tumour grading and positive lymph node status were independently correlated with shorter patient survival.

Conclusions

Reduced expression of DSC2 is independently correlated with shorter patient survival, higher tumour grading and positive lymph node status in PDAC and could serve as a prognostic marker.
What is the significance of flat epithelial atypia and what are the management implications?
Authors: Rajan Sabrina , Sharma Nisha , Dall Barbara J G , Shaaban Abeer M
Published: July 2011

Aims

To assess the significance of flat epithelial atypia (FEA) on core biopsy by evaluating the proportion of cases upgraded to in-situ and invasive carcinoma on further sampling with vacuum-assisted biopsy (VAB) or diagnostic surgical biopsy.

Methods

A retrospective analysis was performed of all core biopsies containing FEA and/or atypical intraductal proliferation (AIDP) in the pathology database from April 2008 to April 2010 (n=90). Before April 2009, the majority of core biopsies containing FEA and/or AIDP proceeded to surgical biopsy. From April 2009 onwards, a new patient management pathway was introduced incorporating VAB to sample core biopsies containing FEA and/or AIDP as an alternative to surgical biopsy.

Results

Of 90 core biopsies, the following were identified: FEA only in 42%; FEA with concomitant AIDP in 21% and AIDP only in 37%. There was a stepwise increase in the proportion of cases upgraded to in-situ or invasive carcinoma: 19% in the FEA group; 29% in the FEA and AIDP group and 53% in the AIDP group. In the FEA-only group, one invasive tumour (grade 1 tubular carcinoma) and six cases of ductal carcinoma in situ were found.

Conclusion

The presence of FEA on core biopsy warrants further tissue sampling to ensure concomitant malignancy is not missed. Sampling with VAB provides sufficient tissue for histopathological evaluation, reducing the need for surgical biopsy. It is important that the utilisation of VAB is incorporated into a safe patient management pathway with careful multidisciplinary team discussion to ensure radiological–pathological concordance.
Noise exposure and serious injury to active sawmill workers in British Columbia
Authors: Kling Rakel N , Demers Paul A , Alamgir Hasanat , Davies Hugh W
Published: July 2011

Background

Occupational noise might increase the risk of workplace injury through a variety of mechanisms, including interference with communication and increased stress.

Objectives

The purpose of this study was to assess the effect of chronic noise exposure on serious workplace injury, and how the timing of exposure influenced risk.

Methods

The authors examined a cohort of 26 000 workers, who worked between 1950 and 1989. Cases were those hospitalised for a work-related injury (ICD-9 codes 800–999, and E codes E800–E999), from April 1989 to December 1998. Cumulative exposure levels were estimated for subjects based on a quantitative retrospective exposure assessment. An internal comparison of cumulative noise exposure and subchronic durations of noise exposure and injury was conducted using Poisson regression. There were 163 cases for the cumulative and 161 cases for the subchronic analysis.

Results

Cumulative noise exposure were associated with a decreased risk for injuries, with the risk generally decreasing as cumulative noise levels increased, while most durations of subchronic exposure were associated with an increased risk for injury. An inverse U-shaped trend was observed with the time period of 90 days to 1 year demonstrating the most elevated RR compared with 0–1 days of exposure.

Conclusions

Workers highly exposed to noise, or exposed for long periods of time, might develop effective methods of communicating the risk and preventing injuries when exposed to noise.
Air exposure assessment of TDI and biological monitoring of TDA in urine in workers in polyurethane foam industry
Authors: Geens Tom , Dugardin Sandra , Schockaert Ann , De Cooman Geert , van Sprundel Marc
Published: July 2011

Objectives

Toluene diisocyanate (TDI) is used in the manufacturing process of polyurethane (PU) foams and is a potent inducer of occupational asthma. The objective of this study was to evaluate the correlation between the exposure to total TDI (2,4- and 2,6-TDI) in air and the corresponding biomarker concentration of total TDA (2,4- and 2,6-TDA) in hydrolysed urine. The aim was also to propose an appropriate biological exposure limit for total TDA in urine.

Methods

9 workers from two production lines in a PU foam producing plant were studied. Personal exposure to TDI during four representative production shifts was monitored by an active air sampling method (filter impregnated with 1-(2-methoxyphenyl)piperazine) and quantified by high-performance liquid chromatography and diode array detection (NIOSH n° 2535, 5521). In parallel, pre-shift and post-shift urinary samples were collected from the exposed workers, and TDA concentrations were determined by gas chromatography–mass spectrometry after alkaline hydrolysis. All samples were collected on four measuring days: two Fridays (end of workweek) and two Mondays (start of workweek) separated by a weekend without exposure.

Results

Strong correlations between the personal air concentrations of total TDI and the corresponding biomarker levels of total TDA in urine (r=0.816) were observed. An increase of 18.12 μg TDA/l (post-shift minus pre-shift concentration) corresponds to an exposure of 5 ppb (37 μg/m3, the current American Conference of Governmental Industrial Hygienists threshold limit value) during the shift.

Conclusions

The increase in TDA during the shift is a suitable biomarker for exposure to TDI during the same shift. Further research is needed to evaluate the use of start of week or end of week post-shift TDA in urine as biomarker since TDA was found to accumulate during the working week and thus the moment of sampling will clearly influence the result.
Thromboelastographic changes after gonadectomy in retired racing greyhounds
Authors: Saavedra P. Vilar , Stingle N. , Iazbik C. , Marín L. , McLoughlin M. A. , Xie Y. , Couto G.
Published: July 2011

Twenty‐one healthy greyhounds with no history or clinical signs of bleeding disorders, and no abnormalities on physical examination, complete blood count, serum biochemistry profiles (in dogs more than five years of age), and SNAP‐4DX test for vector borne diseases underwent routine gonadectomies at the Ohio State University Veterinary Teaching Hospital. Blood samples were collected 24 hours before and after surgery by jugular venepuncture for thromboelastography and haemostasis assays (prothrombin time [PT], activated partial thromboplastin time [aPTT], fibrinogen concentration). The magnitude of the bleeding in each patient was estimated using a bleeding scoring system recently validated in greyhounds. Eight dogs were classified as bleeders and 13 as non‐bleeders. Thromboelastograph (TEG) tracings in bleeders were different to that of non‐bleeders. Neither sex (odds ratio [OR]: 0.148, P=0.05), haematocrit (OR: 0.907, P=0.39), platelet count (OR: 0.996, P=0.65) or age (OR: 0.949, P=0.83) were predictors of the outcome. None of the variables that evaluated clot kinetics, and fibrinolysis (that is, aPTT OR: 0.781, P=0.51; PT OR: 1.337, P=0.63; TEGROR: 1.269, P=0.06; TEGKOR: 1.696, P=0.05; TEGLY60OR: 1.028, P=0.81) were able to predict the bleeding episodes. Only the TEG variables that represent the fibrin cross‐linking of the clot (TEGangleOR: 0.903, P=0.03); and the strength of the clot (TEGMAOR: 0.833, P=0.03) were considered predictors of the outcome.
F(T) MODELS WITHIN BIANCHI TYPE-I UNIVERSE
Authors: SHARIF M. , RANI SHAMAILA
Published: July 2011

In this paper, we consider spatially homogeneous and anisotropic Bianchi type I universe in the context of F(T) gravity. We construct some corresponding models using conservation equation and equation of state parameter representing different phases of the universe. In particular, we take matter-dominated era, radiation-dominated era, present dark energy phase and their combinations. It is found that one of the models has a constant solution which may correspond to the cosmological constant. We also derive equation of state parameter by using two well-known F(T) models and discuss cosmic acceleration.
COMPLEXIFIED SIGMA-MODEL AND DUALITY
Authors: NIETO J. A.
Published: July 2011

We show that the equations of motion associated with a complexified sigma-model action do not admit manifest dual SO (n, n) symmetry. In the process we discover new type of numbers which we called "complexoids" in order to emphasize their close relation with both complex numbers and matroids. It turns out that the complexoids allow one to consider the analogue of the complexified sigma-model action but with (1+1)-worldsheet metric, instead of Euclidean-worldsheet metric. Our observations can be useful for further developments of complexified quantum mechanics.
DKP EQUATION UNDER A VECTOR HULTHÉN-TYPE POTENTIAL: AN APPROXIMATE SOLUTION
Authors: ZARRINKAMAR S. , RAJABI A. A. , RAHIMOV H. , HASSANABADI H.
Published: July 2011

Approximate analytical solutions of Duffin–Kemmer–Petiau equation are obtained for a vector Hulthén potential. The solutions are reported for any J-state using an elegant approximation and methodology of supersymmetry quantum mechanics.
MULTI-AXIS LINKED SERVO SYSTEM CONTOURING ERROR CONTROL APPROACH BASED ON NURBS CURVE INTERPOLATION
Authors: ZHAO GUOYONG , ZHAO YUGANG
Published: July 2011

The contouring precision of computer numerical control (CNC) machine tools relates to whether the dynamic performances among all the axes match or not. In general, the cross-coupled controller (CCC) is a more efficient approach to enhance contouring precision than single-axis servo controller. Note that the contouring error CCC can not be separated from pathway programming in multi-axis linked servo system. In order to obtain satisfied contouring precision, the CCC approach connected with non-uniform rational basis spline (NURBS) curve interpolation is researched in detail in the paper. Above all, an "arc approximation algorithm" contouring error computing model is developed, according to the real cutter positions from each axis feedback and the interpolation dots stored in the interpolation buffer. Then the contouring error correction quantity PI control and distribution algorithm is put forward by introducing a zoom coefficient. The contrast experimental results on the CNC experiment table show that the developed CCC approach can reduce contouring error and improve tracking performance further.
A HIGHER FIDELITY MODELING OF THE CUTTING EDGE OF BALL-END MILLING TOOL
Authors: SUI XIULIN , HORVATH IMRE , ZHANG JIATAI , ZHANG PING
Published: July 2011

Ball-end milling tools have been widely used in machining of complex freeform surfaces. The precision and efficiency of ball-end milling process can be improved by an accurate modeling of the tools, the tools' paths and the machining conditions. However, only rough geometric models have been applied so far, which do not consider the machining conditions and the physical changes. To achieve the best results, an accurate modeling of the cutting edge and the physical behavior of the entire cutter is needed. This paper proposes an articulated model that enumerates both the geometric characteristics and the physical effects acting on the cutting edge-segment of a ball-end milling cutter. The model considers the deformations caused by the milling forces, vibration, spindle eccentricity, together with thermal deformation and wear of the cutter. The mathematical description of the behavior has been transferred into a computational model. The pilot implementation has been tested in a practical application. The first findings show that the proposed theoretical model and implementation provide sufficiently precise information about the behavior of the cutter in virtual simulations; hence it can be the basis of a fully fledged and more efficient planning of milling processes.
APPLICATION OF THE DIV-CURL LEMMA FOR MAXWELL'S EQUATIONS WITH NON-LINEAR CONDUCTIVITY
Authors: DURAND STEPHANE
Published: July 2011

In this paper, we study a non-linear hyperbolic system, occuring in the study of electromagnetic fields in the presence of superconductors. The constitutive relation between current density and the electric field is then highly non-linear. Based on a stability estimate in the dual space, we are able to prove the convergence of backward Euler's method toward the unique solution of the problem. This requires a compensated compactness argument (div-curl lemma) and the Minty–Browder procedure to pull weak convergence through a monotone non-linearity. Finally, we present the corresponding error estimates.
GLOBAL SMOOTH FLOWS FOR THE COMPRESSIBLE EULER–MAXWELL SYSTEM: THE RELAXATION CASE
Authors: DUAN RENJUN
Published: July 2011

The Euler–Maxwell system regarded as a hydrodynamic model for plasma physics describes the dynamics of 'compressible electrons' in a constant, charged, non-moving ion background. A global smooth flow with small amplitude is constructed here in three space dimensions when the electron velocity relaxation is taken into account. The speed of the electron flow tending to a uniform equilibrium, and the pointwise behavior of solutions to the linearized homogeneous system in the frequency space are investigated in detail.
Cerebral and myocardial blood flow responses to hypercapnia and hypoxia in humans
Authors: Beaudin Andrew E. , Brugniaux Julien V. , Vöhringer Matthias , Flewitt Jacqueline , Green Jordin D. , Friedrich Matthias G. , Poulin Marc J.
Published: July 2011

In humans, cerebrovascular responses to alterations in arterial Pco2 and Po2 are well documented. However, few studies have investigated human coronary vascular responses to alterations in blood gases. This study investigated the extent to which the cerebral and coronary vasculatures differ in their responses to euoxic hypercapnia and isocapnic hypoxia in healthy volunteers. Participants ( n = 15) were tested at rest on two occasions. On the first visit, middle cerebral artery blood velocity ( V̄P) was assessed using transcranial Doppler ultrasound. On the second visit, coronary sinus blood flow (CSBF) was measured using cardiac MRI. For comparison with V̄P, CSBF was normalized to the rate pressure product [an index of myocardial oxygen consumption; normalized (n)CSBF]. Both testing sessions began with 5 min of euoxic [end-tidal Po2 (PetO2) = 88 Torr] isocapnia [end-tidal Pco2 (PetCO2) = +1 Torr above resting values]. PetO2 was next held at 88 Torr, and PetCO2 was increased to 40 and 45 Torr in 5-min increments. Participants were then returned to euoxic isocapnia for 5 min, after which PetO2 was decreased from 88 to 60, 52 and 45 Torr in 5-min decrements. Changes in V̄P and nCSBF were normalized to isocapnic euoxic conditions and indexed against PetCO2 and arterial oxyhemoglobin saturation. The V̄P gain for euoxic hypercapnia (%/Torr) was significantly higher than nCSBF ( P = 0.030). Conversely, the V̄P gain for isocapnic hypoxia (%/%desaturation) was not different from nCSBF ( P = 0.518). These findings demonstrate, compared with coronary circulation, that the cerebral circulation is more sensitive to hypercapnia but similarly sensitive to hypoxia.
Acute exercise activates AMPK and eNOS in the mouse aorta
Authors: Cacicedo José M. , Gauthier Marie-Soleil , Lebrasseur Nathan K. , Jasuja Ravi , Ruderman Neil B. , Ido Yasuo
Published: July 2011

Exercise can prevent endothelial cell (EC) dysfunction and atherosclerosis even in the absence of improvements in plasma lipids. However, the mechanisms responsible for these effects are incompletely understood. In this study we examined in mice whether an acute bout of exercise activates enzymes that could prevent EC dysfunction, such as AMP-activated protein kinase (AMPK) and endothelial nitric oxide synthase (eNOS). We also examined whether exercise alters known regulators of these enzymes. C57BL/6 mice underwent a single bout of exhaustive treadmill exercise after which their aortas were analyzed for activation of AMPK, AMPK regulatory proteins, eNOS, and various enzymes that, like AMPK, activate eNOS. We found that such exercise acutely activates both AMPK and eNOS in the whole aorta and that the magnitude of these effects correlated with both the distance run and activation of the AMPK regulatory proteins silent information regulator-1 (SIRT1)-LKB1 and CaMKKβ. In contrast, Akt, PKA, PKG, and Src, other kinases known to activate eNOS, were unaffected. Immunohistochemical analysis revealed that AMPK and eNOS were both activated in the ECs of the aorta. This study provides the first evidence that an acute bout of exercise activates AMPK and eNOS in the endothelium of the aorta. The results also suggest that AMPK likely is the principal activator of eNOS in this setting and that its own activation may be mediated by both SIRT1-LKB1 and CaMKKβ.
Lipopolysaccharide-induced injury is more pronounced in fetal transgenic ErbB4-deleted lungs
Authors: Schmiedl Andreas , Behrens Jan , Zscheppang Katja , Purevdorj Erkhembulgan , von Mayersbach Dietlinde , Liese Andrea , Dammann Christiane E. L.
Published: July 2011

Pulmonary ErbB4 deletion leads to a delay in fetal lung development, alveolar simplification, and lung function disturbances in adult mice. We generated a model of intrauterine infection in ErbB4 transgenic mice to study the additive effects of antenatal LPS administration and ErbB4 deletion during fetal lung development. Pregnant mice were treated intra-amniotically with an LPS dose of 4 μg at E17 of gestation. Lungs were analyzed 24 h later. A significant influx of inflammatory cells was seen in all LPS-treated lungs. In heterozygote control lungs, LPS treatment resulted in a delay of lung morphogenesis characterized by a significant increase in the fraction of mesenchyme, a decrease in gas exchange area, and disorganization of elastic fibers. Surfactant protein (Sftp)b and Sftpc were upregulated, but mRNA of Sftpb and Sftpc was downregulated compared with non-LPS-treated controls. The mRNA of Sftpa1 and Sftpd was upregulated. In ErbB4-deleted lungs, the LPS effects were more pronounced, resulting in a further delay in morphological development, a more pronounced inflammation in the parenchyma, and a significant higher increase in all Sftp. The effect on Sftpb and Sftpc mRNA was somewhat different, resulting in a significant increase. These results imply a major role of ErbB4 in LPS-induced signaling in structural and functional lung development.
Balance of life and death in alveolar epithelial type II cells: proliferation, apoptosis, and the effects of cyclic stretch on wound healing
Authors: Crosby Lynn M. , Luellen Charlean , Zhang Zhihong , Tague Larry L. , Sinclair Scott E. , Waters Christopher M.
Published: July 2011

After acute lung injury, repair of the alveolar epithelium occurs on a substrate undergoing cyclic mechanical deformation. While previous studies showed that mechanical stretch increased alveolar epithelial cell necrosis and apoptosis, the impact of cell death during repair was not determined. We examined epithelial repair during cyclic stretch (CS) in a scratch-wound model of primary rat alveolar type II (ATII) cells and found that CS altered the balance between proliferation and cell death. We measured cell migration, size, and density; intercellular gap formation; cell number, proliferation, and apoptosis; cytoskeletal organization; and focal adhesions in response to scratch wounding followed by CS for up to 24 h. Under static conditions, wounds were closed by 24 h, but repair was inhibited by CS. Wounding stimulated cell motility and proliferation, actin and vinculin redistribution, and focal adhesion formation at the wound edge, while CS impeded cell spreading, initiated apoptosis, stimulated cytoskeletal reorganization, and attenuated focal adhesion formation. CS also caused significant intercellular gap formation compared with static cells. Our results suggest that CS alters several mechanisms of epithelial repair and that an imbalance occurs between cell death and proliferation that must be overcome to restore the epithelial barrier.
Comparative Bioremediation of Crude Oil-Amended Tropical Soil Microcosms by Natural Attenuation, Bioaugmentation, or Bioenrichment
Authors: Alvarez Vanessa Marques , Marques Joana Montezano , Korenblum Elisa , Seldin Lucy
Published: July 2011

Bioremediation is an efficient strategy for cleaning up sites contaminated with organic pollutants. In this study, we evaluated the effectiveness of monitored natural attenuation, bioenrichment, and bioaugmentation using a consortium of three actinomycetes strains in remediating two distinct typical Brazilian soils from the Atlantic Forest and Cerrado biomes that were contaminated with crude oil, with or without the addition of NaCl. Microcosms were used to simulate bioremediation treatments over a 120-day period. During this period, we monitored total petroleum hydrocarbons (TPHs) and n-alkanes degradation and changes in bacterial communities. Over time, we found the degradation rate of n-alkanes was higher than TPH in both soils, independent of the treatment used. In fact, our data show that the total bacterial community in the soils was mainly affected by the experimental period of time, while the type of bioremediation treatment used was the main factor influencing the actinomycetes populations in both soils. Based on these data, we conclude that monitored natural attenuation is the best strategy for remediation of the two tropical soils studied, with or without salt addition.
The Effect of Arterial pH on Oxygenation Persists Even in Infants Treated with Inhaled Nitric Oxide
Authors: Barton Aimee M. , Abubakar M. Kabir , Berg Jennifer , Keszler Martin
Published: July 2011

Objective. To validate the empiric observation that pH has an important effect on oxygenation in infants receiving iNO.Study Design. Demographics, ventilator settings, arterial blood gases (ABG), and interventions for up to 96 hours of life were extracted from the charts of 51 infants receiving iNO. Need for ECMO and survival to discharge were noted. Mean blood pressure (MBP) and mean airway pressure (MAP) were recorded. The arterial/alveolar (a/A) ratio was used as the primary outcome. Analysis was by simple linear regression and multiple linear regression analyses and Fisher's exact test. pH responsiveness was arbitrarily defined as a correlation coefficient (CC) of >0.40 with .Results. Mean gestational age was 38.8 weeks and mean birth weight was 3300 g. All patients had clinical diagnosis of PPHN. Clear responsiveness to pH was found in 31/51 infants. MAP and MBP did not correlate with a/A ratio. Three responders had a critical pH > 7.55. Of 11 patients requiring ECMO, only 3 exhibited responsiveness at any time in their course. Three responders required ECMO.Conclusion. This small study suggests that failure or inability to optimize pH may account for observed unresponsiveness to iNO. Maintaining a pH > 7.5 using hyperventilation is not recommended.
Modified Exposure and Response Prevention to Treat the Repetitive Behaviors of a Child with Autism: A Case Report
Authors: Boyd Brian A. , Woodard Cooper R. , Bodfish James W.
Published: July 2011

We report the case study of a school-aged child with autism whose repetitive behaviors were treated with a modified version of a technique routinely used in cognitive behavior therapy (i.e., exposure response prevention) to treat obsessive-compulsive disorder. A trained behavioral therapist administered the modified ERP treatment over the course of an intensive two-week treatment period with two therapy sessions occurring daily. The treatment was successful at decreasing the amount of child distress and cooccurring problem behavior displayed; however, the child's interest in the repetitive behavior eliciting stimulus (i.e., puzzles) remained. The case study demonstrates specific ways that exposure response prevention strategies can be adapted to the unique kinds of repetitive behaviors that present clinically in autism. A larger clinical trial is needed to substantiate these findings.
A Simple Technique to Estimate the Flammability Index of Moroccan Forest Fuels
Authors: Hachmi M′Hamed , Sesbou Abdessadek , Benjelloun Hassan , El Handouz Nesrine , Bouanane Fadoua
Published: July 2011

A formula to estimate forest fuel flammability index (FI) is proposed, integrating three species flammability parameters: time to ignition, time of combustion, and flame height. Thirty‐one (31) Moroccan tree and shrub species were tested within a wide range of fuel moisture contents. Six species flammability classes were identified. An ANOVA of the FI‐values was performed and analyzed using four different sample sizes of 12, 24, 36, and 50 flammability tests. Fuel humidity content is inversely correlated to the FI‐value, and the linear model appears to be the most adequate equation that may predict the hypothetical threshold‐point of humidity of extinction. Most of the Moroccan forest fuels studied are classified as moderately flammable to flammable species based on their average humidity content, calculated for the summer period from July to September.
Endovascular Treatment of a Right-Sided Ureteroiliac Fistula in a Patient with a Simultaneous Left-Sided Ureteroileal Fistula
Authors: Veenstra G. M. , Fossion L. M. C. L. , Debonnaire G. , de Laet K.
Published: July 2011

We describe an 80-year-old female with a left ureteroileal fistula and simultaneously a right ureteroiliac fistula. Her history highlights the predisposing factors of radiation, major surgery in the region, and presence of bilateral double-J-stents. She was successfully treated with an endovascular approach after being initially misdiagnosed. There seems to be an increase in reporting ureteral fistulas, however this entity remains a rare clinical condition that can lead to life-threatening situations. A fast and accurate diagnosis of an ureteroarterial fistula remains a challenge.
Brain Plasticity and Disease: A Matter of Inhibition
Authors: Baroncelli Laura , Braschi Chiara , Spolidoro Maria , Begenisic Tatjana , Maffei Lamberto , Sale Alessandro
Published: July 2011

One major goal in Neuroscience is the development of strategies promoting neural plasticity in the adult central nervous system, when functional recovery from brain disease and injury is limited. New evidence has underscored a pivotal role for cortical inhibitory circuitries in regulating plasticity both during development and in adulthood. This paper summarizes recent findings showing that the inhibition-excitation balance controls adult brain plasticity and is at the core of the pathogenesis of neurodevelopmental disorders like autism, Down syndrome, and Rett syndrome.
Thrombospondin-1: Multiple Paths to Inflammation
Authors: Lopez-Dee Zenaida , Pidcock Kenneth , Gutierrez Linda S.
Published: July 2011

Inflammation is a defensive process against tissue injury. Once this self-protective strategy is initiated, an effective resolution of the process is crucial to avoid major and unnecessary tissue damage. If the underlying event inducing inflammation is not addressed and homeostasis is not restored, this process can become chronic and lead to angiogenesis and carcinogenesis. Thrombospondin-1 (TSP-1) is a matricellular protein involved in angiogenesis, cancer, and inflammation. The effects of TSP-1 have been studied in many preclinical tumor models, and mimetic peptides are being tested in cancer clinical trials. However, the molecular mechanisms explaining its role in inflammatory processes are not well understood. This paper will discuss the role of TSP-1 in inflammation and its interaction with key receptors that may explain its functions in that process. Recent literature will be reviewed showing novel mechanisms by which this multifaceted protein could modulate the inflammatory process and impact its resolution.