bluuebunny/crossref_metadata_2025 huggingface dataset:
Simplified analysis of a low-rise building seismically isolated with stable unbonded fiber reinforced elastomeric isolators
Authors: Toopchi-Nezhad Hamid , Tait Michael J. , Drysdale Robert G.
Published: September 2009

The seismic response of an ordinary low-rise base isolated (BI) structure, employing stable unbonded-fiber reinforced elastomeric isolator (SU-FREI) bearings, is predicted by using two different simplified analytical models. Subsequently, the accuracy of the two models is evaluated by using measured test results from a shake table study. Two models simulate the nonlinear experimental lateral load–displacement hysteresis loops of these bearings. The experimental hysteresis loops were obtained from cyclic shear tests on prototype bearings under a constant compression load. Because of the nonlinear lateral response behavior of the SU-FREIs, these models are employed in an iterative time-history analysis approach, enabling the model variables and the calculated peak lateral displacement of the bearings to converge to their unique values. Analysis results show that the presented simplified models may be used effectively in seismic response prediction of ordinary low-rise buildings that are seismically isolated by SU-FREI bearings.
Backwater calculations for the St. Lawrence Seaway with the first computer in Canada
Authors: Campbell Scott M.
Published: September 2009

As the oldest branch of engineering, it is fitting that civil engineering was the first in Canada to make use of modern computing techniques. In the early 1950s, serious planning was underway regarding the St. Lawrence Seaway and Power Project, but before construction could begin, a lengthy series of backwater calculations was required to predict upriver changes to the water profile. It was estimated that these calculations would have taken 20 person-years to complete by hand, but in 1952 and 1953 Ontario Hydro was able to make use of the first electronic computer in Canada – the Ferut at the University of Toronto – to complete in about eight months. These were the first major calculations carried out on any electronic computer in Canada, and helped prove that an all-Canadian navigation route was possible.
Risk assessment of international construction projects using the analytic network process
Authors: Bu-Qammaz Amani Suliman , Dikmen Irem , Birgonul M. Talat
Published: September 2009

In this study, an analytic network process (ANP), which can handle the interrelations between risk related factors, is proposed as a reliable technique for measuring the level of risk associated with international construction projects. Within this context, ANP is used to derive the relative priorities of risk factors as an input to a decision support tool, which can be utilized during bidding decisions. The decision support tool may help a decision maker to estimate the level of risk so that alternative projects may be ranked with respect to their risk levels and appropriate contingency values may be defined after a bid decision is given. The tool has a database in which risk information of the rated projects can be stored for future use. The reliability of the tool was tested on eight real cases and satisfactory results were achieved in estimating the risk level.
Optimization of phosphorus removal in secondary effluent using immersed ultrafiltration membranes with in-line coagulant pretreatment — implications for advanced water treatment and reuse applicationsA paper submitted to the Journal of Environmental Engineering and Science.
Authors: Citulski Joel , Farahbakhsh Khosrow , Kent Fraser
Published: September 2009

In-line addition of alum and ferric chloride was conducted at a hollow-fibre immersed ultrafiltration (UF) membrane pilot plant, using secondary effluent from a municipal wastewater treatment plant (WWTP) as the feed. The objective of such pretreatment was to remove phosphorus from the feed from an initial concentration of approximately 5 mg/L to below 0.3 mg/L. The simplified in-line coagulant addition process involved hydraulic mixing of the coagulant into the feed and subsequent flocculation, and a greatly reduced (12–14 min) flocculation time relative to conventional coagulation-flocculation-settling treatment. Both alum and ferric chloride effectively removed phosphorus to below the 0.3 mg/L threshold when applied as a pretreatment at optimized doses, both of which were below the WWTP’s current coagulant dose (as ferrous chloride). This simplified pre-treatment scheme provided consistent enhanced removal of phosphorus and organic compounds. These results suggest that simplified in-line coagulant addition in advance of immersed UF membranes enhances the ability to produce treated effluent suitable for water-reuse applications.
Coordinate Gα13 and Wnt6-β-catenin signaling in F9 embryonal carcinoma cells is required for primitive endoderm differentiation
Authors: Krawetz Roman , Kelly Gregory M.
Published: September 2009

The mouse F9 embryonal carcinoma cell line is ideally suited to study the epithelial-to-mesenchymal transition accompanying the differentiation of primitive to parietal extraembryonic endoderm. In F9 cells, the application of exogenous agents including retinoic acid or activation of signal transduction cascades downstream of G-proteins triggers widespread changes in gene expression and leads to the formation of primitive endoderm. The epithelial-to-mesenchymal transition is completed and parietal endoderm develops as of result of increasing PKA activity in primitive endoderm cells. Expression of a constitutively active form of Gα13(Q226L) is sufficient to induce F9 cells into parietal endoderm and a model is emerging that a signaling axis linking G-protein signaling to RhoA and the ERM protein moesin is required for differentiation. In this study, we found that expression of either p115RhoGEF or a constitutively active, GTPase-deficient form of RhoA(L63) promoted primitive, but not parietal, endoderm formation. The overexpression of Gα13(Q226L) or p115RhoGEF, but not Rho(L63), caused β-catenin to translocate to the nucleus. Surprisingly, the stimulation of the Wnt-β-catenin pathway was accompanied by nuclear β-catenin and primitive endoderm formation, even when a dominant negative was used to block the signaling axis at the level of p115RhoGEF or when ROCK activity was inhibited using the pharmacological agent Y-27632. Together, results indicate that the coordinate signaling by two independent pathways, one involving canonical Wnt-β-catenin activation of target genes and the other with Gα13 signaling to ERM proteins to modulate cytoarchitectural changes, is required during the retinoic acid induced differentiation of F9 cells to primitive endoderm.
Calreticulin and focal-contact-dependent adhesion
Authors: Villagomez Maria , Szabo Eva , Podcheko Alexey , Feng Tianshu , Papp Sylvia , Opas Michal
Published: September 2009

Cell adhesion is regulated by a variety of Ca2+-regulated pathways that depend on Ca2+-binding proteins. One such protein is calreticulin, an ER-resident protein. Calreticulin signalling from within the ER can affect processes outside the ER, such as expression of several adhesion-related genes, most notably vinculin and fibronectin. In addition, changes in the expression level of calreticulin strongly affect tyrosine phosphorylation of cellular proteins, which is known to affect many adhesion-related functions. While calreticulin has been localized to cellular compartments other than the ER, it appears that only the ER-resident calreticulin affects focal-contact-dependent adhesion. In contrast, calreticulin residing outside the ER may be involved in contact disassembly and other adhesion phenomena. Here, we review the role of calreticulin in focal contact initiation, stabilization, and turnover. We propose that calreticulin may regulate cell–substratum adhesion by participating in an “ER-to-nucleus” signalling and in parallel “ER-to-cell surface” signalling based on posttranslational events.
Contribution of bone marrow mesenchymal stem cells to porcine hepatocyte culture in vitro
Authors: Gu Jinyang , Shi Xiaolei , Chu Xuehui , Zhang Yue , Ding Yitao
Published: September 2009

One of the greatest challenges in the attempt to create functional bioartificial liver designs is the maintenance of porcine hepatocyte differentiated functions in vitro. Co-cultivation of hepatocytes with nonparenchymal cells may be beneficial for optimizing cell functions via mimicry of physiological microenvironment. However, the underlying mechanisms remain to be elucidated. An equal number of freshly isolated porcine hepatocytes and purified bone marrow mesenchymal stem cells (MSCS) was randomly co-cultured and the morphological and functional changes of heterotypic interactions were characterized. Furthermore, contributions of soluble factors involved in the separated co-culture system were evaluated. The purity of the third-passage MSCS and primary hepatocytes was more than 90% and 99%, respectively. Hepatocyte viability was greater than 95%. A rapid attachment and self-organization of three-dimensional hepatocyte spheroids were encouraged, which was due to the supporting MSCS of high motility. The elevated induction of both albumin production and urea synthesis was achieved in co-culture (P < 0.05). Data from semipermeable membrane cultures suggested that interleukin-6 is one of the key stimulators in hepatic functional enhancement. These results demonstrate for the first time that soluble factors have beneficial effects on the preservation of hepatic morphology and functionality in the co-culture of hepatocytes with MSCS in vitro, which could represent a promising tool for tissue engineering, cell biology, and bioartificial liver devices.
Cadmium attenuates bradykinin-driven nitric oxide production by interplaying with the localization pattern of endothelial nitric oxide synthase
Authors: Majumder Syamantak , Gupta Ravi , Reddy Himabindu , Sinha Swaraj , Muley Ajit , Kolluru Gopi Krishna , Chatterjee Suvro
Published: September 2009

Cadmium, a ubiquitous heavy metal, interferes with endothelial functions and angiogenesis. Bradykinin is a Ca-mobilizing soluble peptide that acts via nitric oxide to promote vasodilation and capillary permeability. The objective of the present study was to explore the Cd implications in bradykinin-dependent endothelial functions. An egg yolk angiogenesis model was employed to evaluate the effect of Cd on bradykinin-induced angiogenesis. The results demonstrate that 100 nmol/L Cd attenuated bradykinin-dependent angiogenesis. The results of the in vitro wound healing and tube formation assays by using EAhy 926, a transformed endothelial cell line, suggest that Cd blocked bradykinin-mediated endothelial migration and tube formation by 38% and 67%, respectively, while nitric oxide supplementation could reverse the effect of Cd on bradykinin-induced endothelial migration by 94%. The detection of nitric oxide by using a DAF-2DA fluorescent probe, Griess assay, and ultrasensitive electrode suggests that Cd blocked bradykinin-induced nitric oxide production. Fluorescence imaging of eNOS-GFP transfected endothelial cells, immunofluroscence, and Western blot studies of Cd and bradykinin-treated cells show that Cd interfered with the localization pattern of eNOS, which possibly attenuates nitric oxide production in part. Additionally, Ca imaging of Cd- and bradykinin-treated cells suggests that Cd blocked bradykinin-dependent Ca influx into the cells, thus partially blocking Ca-dependent nitric oxide production in endothelial cells. The results of this study conclude that Cd blunted the effect of bradykinin by interfering with the Ca-associated NOS activity specifically by impeding subcellular trafficking of eNOS.
Bifidobacterial survival in surface water and implications for microbial source tracking
Authors: Ottoson Jakob R.
Published: September 2009

Bifidobacteria are common in the intestines of humans and other animals. Sorbitol-fermenting Bifidobacteria (SFB) are associated with human faecal pollution. The ratio of total Bifidobacteria (TB) to SFB has been proposed to be a means for determining the source (human or animal) of faecal pollution. In this study, SFB were detected in all sewage samples (n = 39) and in 42% of samples of animal origin (n = 24): pig (5/6 positive), poultry (4/8), horse (1/4), and cow (0/6). The TB:SFB ratio was significantly higher in animal samples than in sewage samples (p < 0.01), with the exception of stored poultry manure, which had ratios (1.4–11) similar to the sewage samples (1–17). The lowest ratio in the other animal samples was 40 (pig). The TB:SFB ratio in sewage remained stable over time in surface water, and it may be a useful screening tool to determine the source of faecal pollution in surface water. Bifidobacteria died off in a log linear manner at 4 and 22 °C, with rates of disappearance of 0.16 and 0.58 log(days–1), respectively. Faecal coliforms (FC) disappeared more slowly (0.09 and 0.43 log(days–1), respectively). The FC:SFB ratio proved to be an inadequate tool for determining the age of sewage pollution.
Global responses ofEscherichia colito adverse conditions determined by microarrays and FT-IR spectroscopy
Authors: Moen Birgitte , Janbu Astrid Oust , Langsrud Solveig , Langsrud Øyvind , Hobman Jon L. , Constantinidou Chrystala , Kohler Achim , Rudi Knut
Published: September 2009

The global gene expression and biomolecular composition in an Escherichia coli model strain exposed to 10 adverse conditions (sodium chloride, ethanol, glycerol, hydrochloric and acetic acid, sodium hydroxide, heat (46 °C), and cold (15 °C), as well as ethidium bromide and the disinfectant benzalkonium chloride) were determined using DNA microarrays and Fourier transform infrared (FT-IR) spectroscopy. In total, approximately 40% of all investigated genes (1682/4279 genes) significantly changed expression, compared with a nonstressed control. There were, however, only 3 genes (ygaW (unknown function), rmf (encoding a ribosomal modification factor), and ghrA (encoding a glyoxylate/hydroxypyruvate reductase)) that significantly changed expression under all conditions (not including benzalkonium chloride). The FT-IR analysis showed an increase in unsaturated fatty acids during ethanol and cold exposure, and a decrease during acid and heat exposure. Cold conditions induced changes in the carbohydrate composition of the cell, possibly related to the upregulation of outer membrane genes (glgAP and rcsA). Although some covariance was observed between the 2 data sets, principle component analysis and regression analyses revealed that the gene expression and the biomolecular responses are not well correlated in stressed populations of E. coli, underlining the importance of multiple strategies to begin to understand the effect on the whole cell.
The IL-6-deficient mouse exhibits impaired lymphocytic responses to a vaccine combining liveLeishmania majorand CpG oligodeoxynucleotides
Authors: Wu Wenhui , Weigand Luise , Mendez Susana
Published: September 2009

We have previously reported that vaccination with CpG oligodeoxynucleotides delivered concomitantly with live Leishmania major (Lm/CpG) eliminates lesions associated with live vaccination in C57BL/6 mice. The absence of lesions is at least in part a result of the CpG DNA-mediated activation of dermal dendritic cells to produce cytokines such as interleukin (IL)-6. Wild-type C57BL/6 mice and IL-6−/− mice were immunized with the Lm/CpG vaccine and monitored for the development of lesions. IL-6−/− mice developed extensive, nonhealing lesions following live vaccination. The analysis of the inoculation site and draining lymph nodes of the IL-6−/− mice revealed a constitutive reduction in lymphocyte numbers, particularly CD4+ T cells. Live vaccination resulted in the specific expansion of CD4+Foxp3+ regulatory T cells in the knockout mice, and in a decrease of CD4+ IFN-γ -producing cells. These results indicate that IL-6−/− mice may have collateral immune defects that could influence the development of the natural immune response to pathogens, vaccines, or other inflammatory stimuli.
Differential response ofPichia guilliermondiispoilage isolates to biological and physico-chemical factors prevailing in Patagonian wine fermentations
Authors: Lopes Christian A. , Sáez Julieta S. , Sangorrín Marcela P.
Published: September 2009

Pichia guilliermondii can produce volatile phenols in the initial stages of wine fermentation; however, its response to different wine stress conditions has been poorly studied. In this work, we present an analysis of the response of 23 P. guilliermondii indigenous isolates to physical and chemical wine stress factors and to indigenous wine killer yeasts. Principal coordinates analysis (PCoA), based on data obtained from response patterns, was carried out to evaluate the relationships among the isolates. Major differences among the isolates were detected in media plates containing 8% ethanol and in those containing 280 g/L glucose. PCoA identified 3 clusters of isolates with different stress response patterns, indicating a relationship between the tolerance to these compounds and the origin of the isolates. Pichia guilliermondii isolates were sensitive to the toxins produced by the species Hanseniaspora uvarum , Metschnikowia pulcherrima , Wickerhamomyces anomala (ex Pichia anomala ), and Pichia kluyveri , with a maximum level of sensitivity against W. anomala (91% on average). Those isolates obtained from fermenting must proved to be more resistant to killer yeasts than those obtained from grape surfaces. The combined evaluation of the response to physico-chemical and biological factors presented in this work could be a useful standard protocol for the evaluation of the potential spoilage capacity of yeasts in winemaking.
Lactobacillus casei: influence on the innate immune response and haemostatic alterations in a liver-injury model
Authors: Haro Cecilia , Zelaya Hortensia , Lazarte Sandra , Alvarez Susana , Agüero Graciela
Published: September 2009

Lactobacilllus casei CRL 431 has the ability to modulate the local and systemic immune responses, which are significantly involved in liver injury caused by hepatotoxins. This work was conducted to determine whether L. casei has a preventive effect on the hepatic damage undergone during an acute liver injury (ALI). Methods: ALI was induced by an intraperitoneal injection of d-galactosamine (D-Gal). Different groups of mice received 1× 109 L. casei cells/day/mouse for 2 days before D-Gal injection. Blood and liver samples were obtained 0, 6, 12, and 24 h after D-Gal administration. Results: D-Gal induced increases in serum aminotransferases, reduced the number of blood leukocytes, enhanced neutrophil myeloperoxidase activity, increased dead cells, and altered prothrombin time and plasma fibrinogen levels. The preventive treatment with L. casei for 2 days modulated the innate immune response. This effect was shown by the earlier normalization of white blood cell counts, myeloperoxidase activity and aminotransferases levels. However, the haemostatic parameters were only partially recovered. The favourable effects obtained could be due to the capacity of L. casei to moderate the inflammatory response at the site of the injury with less damage to liver tissue.
Oxidative stress response of Mycosphaerella fijiensis, the causal agent of black leaf streak disease in banana plants, to hydrogen peroxide and paraquat
Authors: Beltrán-García Miguel J. , Manzo-Sanchez Gilberto , Guzmán-González Salvador , Arias-Castro Carlos , Rodríguez-Mendiola Martha , Avila-Miranda Martin , Ogura Tetsuya
Published: September 2009

Mycosphaerella fijiensis causes black leaf streak disease in banana and plantain. This fungus is usually attacked by reactive oxygen species secreted by the plant or during exposure to fungicide, however, little is known about the antioxidant response of the fungus. In this study, mycelia were observed to totally decompose 30 mmol/L of hydrogen peroxide (H2O2) within 120 min, liberating oxygen bubbles, and also to survive in concentrations as high as 100 mmol/L H2O2. The oxidative stress responses to H2O2, paraquat, and hydroquinone were characterized in terms of the activities of catalase and superoxide dismutase (SOD). Two active catalase bands were seen in native PAGE induced by H2O2. Band I had monofunctional activity and band II had bifunctional catalase–peroxidase activity. Two isozymes of SOD, distinguishable by their cyanide sensitivity, were found; CuZnSOD was the main one. The combination of H2O2 and 3-aminotriazole reduced the accumulation of biomass up to 40% compared with exposure to H2O2 alone, suggesting that catalase is important for the rapid decomposition of H2O2 and has a direct bearing on cell viability. The results also suggest that the superoxide anion formed through the redox of paraquat and hydroquinone has a greater effect than H2O2 on the cellular viability of M. fijiensis.
Induction ofPseudomonas aeruginosafhpandfhpRby reactive oxygen species
Authors: Koskenkorva-Frank Taija S. , Kallio Pauli T.
Published: September 2009

In Pseudomonas aeruginosa , flavohemoglobin (Fhp) and its cognate regulator FhpR (PA2665) form a protective regulatory circuit, which responds to reactive nitrogen species and is also capable of protecting cells against nitrosative stress. Recently, it has been shown that the expression of the fhp promoter is regulated not only by FhpR, but also by two new regulators, PA0779 and PA3697. It has also been suggested that the bacterial flavohemoglobins (flavoHbs) could play a crucial role in the protection of cells against reactive oxygen species (ROS). Therefore, the role and function of the Fhp/FhpR system during oxidative stress were studied by assessing the viability and membrane integrity of P. aeruginosa cells and by analyzing the promoter activities of fhp and fhpR upon exposure to paraquat, hydrogen peroxide, and tert-butyl hydroperoxide, under both aerobic and low-oxygen conditions. The results showed that under aerobic conditions, both fhp and fhpR promoters are induced by ROS generated by the stressors. Thus, the Fhp/FhpR system is implicated in the oxidative stress response. ROS-induced fhp promoter activity was dependent on FhpR, PA0779, and PA3697 regulators. Tert-butyl hydroperoxide-induced fhpR promoter activity was found to be highly repressed by PA0779, and FhpR showed negative autoregulation of its own promoter. Under low-oxygen conditions, the activity of the fhp promoter was not inducible by ROS, but fhpR promoter activity was induced by paraquat, and hydrogen peroxide was repressed in both cases by the regulators PA0779 and PA3697.
Influence of DNA conformation and role ofcomAandrecAon natural transformation inRalstonia solanacearum
Authors: Mercier Anne , Bertolla Franck , Passelègue-Robe Eugénie , Simonet Pascal
Published: September 2009

Naturally competent bacteria such as the plant pathogen Ralstonia solanacearum are characterized by their ability to take up free DNA from their surroundings. In this study, we investigated the efficiency of various DNA types including chromosomal linear DNA and circular or linearized integrative and (or) replicative plasmids to naturally transform R. solanacearum. To study the respective regulatory role of DNA transport and maintenance in the definite acquisition of new DNA by bacteria, the natural transformation frequencies were compared with those obtained when the bacterial strain was transformed by electroporation. An additional round of electrotransformation and natural transformation was carried out with the same set of donor DNAs and with R. solanacearum disrupted mutants that were potentially affected in competence (comA gene) and recombination (recA gene) functions. Our results confirmed the critical role of the comA gene for natural transformation and that of recA for recombination and, more surprisingly, for the maintenance of an autonomous plasmid in the host cell. Finally, our results showed that homologous recombination of chromosomal linear DNA fragments taken up by natural transformation was the most efficient way for R. solanacearum to acquire new DNA, in agreement with previous data showing competence development and natural transformation between R. solanacearum cells in plant tissues.
Production and biochemical characterization of a type B ferulic acid esterase from Streptomyces ambofaciens
Authors: Kheder Fadi , Delaunay Stéphane , Abo-Chameh Ghassan , Paris Cédric , Muniglia Lionel , Girardin Michel
Published: September 2009

For the first time, the presence of a ferulic acid esterase (FAE) was demonstrated in Streptomyces ambofaciens . This extracellular enzyme was produced on a range of lignocellulosic substrates. The maximal level of activity was detected in the presence of either destarched wheat bran or oat spelt xylan as the sole carbon source. We found that 1% (m/v) of destarched wheat bran was the optimal concentration to induce its production. With this inducer, no ferulic acid dimers were released from the cell wall by the produced FAE. Interestingly, rape cattle cake ( Brassica napus ), which does not contain esterified ferulic acid, was also shown to induce the production of the FAE from S. ambofaciens. The FAE was partially purified from the culture supernatant. The purified enzyme was optimally active at pH 7 and 40 °C. The substrate specificity of the FAE from S. ambofaciens was investigated: the highest activity was determined with methyl p-coumarate, methyl ferulate, and methyl cinnamate. Furthermore, the FAE required a certain distance between the benzene ring and the ester bond to be active. According to these biochemical characteristics, the FAE from S. ambofaciens has been classified as a type B FAE.
Polyhydroxyalkanoates production by actinobacteria isolated from soil
Authors: Matias Fernanda , Bonatto Diego , Padilla Gabriel , Rodrigues Maria Filomena de Andrade , Henriques João Antonio Pêgas
Published: September 2009

Polyhydroxyalkanoates (PHAs) are biodegradable and renewable polymers produced by a wide range of bacterial groups. New microbial bioprospection approaches have become an important way to find new PHA producers and new synthesized polymers. Over the past years, bacteria belonging to actinomycetes group have become known as PHA producers, such as Nocardia and Rhodococcus species, Kineosphaera limosa Liu et al. 2002, and, more recently, Streptomyces species. In this paper, we disclose that there are more actinobacteria PHA producers in addition to the genera cited. Some unusual genera, such as Streptoalloteichus , and some genera frequently present in soil, such as Streptacidiphilus , have been found. Thirty-four isolates were able to accumulate poly(3-hydroxybutyrate) and a number of these have traces of poly(3-hydroxyvalerate) when cultivated on glucose or glucose and casein as carbon source. Furthermore, some strains showed traces of medium chain length PHA. Transmission electron microscopy demonstrated that the PHA accumulation occurs in hyphae and spores.
Isolation of a spermatozoal immobilization factor from Staphylococcus aureus filtrates
Authors: Prabha Vijay , Gupta Tanushree , Kaur Siftjit , Kaur Navchetan , Kala Sushila , Singh Arvind
Published: September 2009

Staphylococcus aureus isolated from the cervix of an infertile woman was found to cause complete immobilization of human spermatozoa in vitro. Only the cell culture and cell-free supernatant showed immobilization activity, indicating that the sperm immobilization factor might be released extracellularly by the organism because no activity was observed with the washed cells. Heat treatment of the supernatant at 60 °C for 10 min waived its immobilizing activity, indicating that the active component may be a protein. The bioactive molecule from the supernatant was purified to homogeneity by ammonium sulfate precipitation, gel permeation chromatography, and ion exchange chromatography. Sperm immobilization factor (SIF) was found to be an ~20 kDa protein. SIF at a concentration of 10 µg/mL was required to cause 100% immobilization of human spermatozoa after 30 min of incubation at 37 °C, whereas a concentration of 150 µg/mL caused immediate immobilization, and a concentration of 200 µg/mL resulted in instant loss of viability of human spermatozoa, observed by eosin–nigrosin staining. Scanning electron microscopy showed that the treatment of human spermatozoa with SIF caused multiple defects in the head, midpiece, neck, and tail region of human spermatozoa.
Prospective study applying spoligotyping directly to DNA from sputum samples of patients suspected of having tuberculosis
Authors: Cafrune Patricia Izquierdo , Possuelo Lia Gonçalves , Ribeiro Andrezza Wolowski , Ribeiro Marta Osório , Unis Gisela , Jarczewski Carla Adriane , Rossetti Maria Lúcia Rosa , Zaha Arnaldo
Published: September 2009

A prospective study was designed to evaluate the clinical usefulness of spoligotyping applied directly to sputum samples. Patients suspected of having tuberculosis were recruited at the Hospital Sanatorio Partenon in Porto Alegre, Brazil. Of the 197 samples included in the analysis, 175 (88.8%) yielded a spoligotyping result that fully matched that obtained from culture. Low bacillary samples presented lower accuracy (50%). From 135 Mycobacterium tuberculosis spoligopatterns, we identified 44 different spoligotypes, of which 21 were shared patterns and 23 were unique. T1 was the most frequent subfamily. The genotyping strategy proposed here presents a short turnaround time and could be helpful in providing rapid information on strain identities in a clinical setting.
The fate and efficacy of benomyl applied to field soils to suppress activity of arbuscular mycorrhizal fungi
Authors: O’Connor Patrick , Manjarrez Maria , Smith Sally E.
Published: September 2009

A systematic application of the fungicide benomyl was used to follow up the suppression of arbuscular mycorrhizal (AM) colonization and to determine its fungitoxic activity and persistence at different depths. Repeated applications of benomyl reduced AM colonization mainly in the upper 0–4 cm layer of the treated soils. Furthermore, AM colonization decreased with soil depth. The activity and persistence of this fungicide was reduced over small changes in depth in the first 10 cm of the soil profile beneath a semiarid herbland at Brookfield Conservation Park (South Australia). Repeated applications of the fungicide only slightly increased the levels of toxicity in the soils, probably because of biodegradation of the fungicide in soils with a recent history of exposure to the fungicide. The decline in fungicide activity at depth was correlated with a decline in the suppressive effect of the fungicide on the activity of AM fungi.
Amplified ribosomal DNA restriction analysis of free-living bacteria present in the headbox of a Canadian paper machine
Authors: Prince Véronique , Simao-Beaunoir Anne-Marie , Beaulieu Carole
Published: September 2009

The headbox water is the main source of bacterial contamination of paper machines. Identification of these bacterial contaminants could be an asset in developing specific control methods. An amplified ribosomal DNA restriction analysis (ARDRA) was carried out to characterize the bacterial communities associated with the headbox water of a paper machine in a Canadian mill in February and July 2006. Eight bacterial genera were identified as the main colonizers present in the headbox water. The genus Meiothermus appeared to be the dominant bacterial group in the Canadian paper machine. Some variation was observed between the February and July clone libraries. Bacterial genera such as Chelatococcus and Hydrogenophilus were only detected in February or in July, respectively. Furthermore, the proportion of Tepidimonas clones in the libraries was higher in July than in February. The metabolic profile of the February and July communities, determined using Biolog EcoPlates, also suggested that temporal variation occurred within the bacterial populations that colonized the headbox of the paper machine.
Sulfate-reducing bacteria in leachate-polluted aquifers along the shore of the East China Sea
Authors: Wu Xiu-Juan , Pan Jian-Liang , Liu Xiang-Long , Tan Jing , Li Dao-Tang , Yang Hong
Published: September 2009

The diversity of sulfate-reducing bacteria (SRB) in the aquifer underlying the Laogang Landfill along the shore of the East China Sea was investigated. The DNA extracted from 15 groundwater samples was subjected to PCR amplification of the dissimilatory sulfite reductase (dsr) gene. Full-length dsrAB amplicons (~1.9 kb) were then used to construct 4 clone libraries, while the dsrB amplicons (~350 bp) were used for denaturing gradient gel electrophoresis (DGGE) analysis. The clones in the 4 libraries covered all cultured SRB lineages, as well as a deeply branching clade not affiliated with any cultured SRB. In addition, nearly 80% of the 388 clones in the 4 libraries were similar to sequences of the Deltaproteobacteria, Desulfobacteriaceae, Desulfovibrionales, Syntrophaceae, and Desulfobulbaceae. Furthermore, a wide variety of marine SRB was detected, which indicated that seawater has infiltrated the aquifer. Indeed, the DGGE profiles revealed obvious variations in SRB diversity among the 15 samples, which clustered in accordance with the sulfate concentration of the samples ([SO42–]). Moreover, the sulfate concentrations and SRB diversity along the leachate plume did not show regular variation, which suggests the impact of both groundwater flow and seawater intrusion.
Leaf-associated bacteria from transgenic white poplar producing resveratrol-like compounds: isolation, molecular characterization, and evaluation of oxidative stress tolerance
Authors: Balestrazzi Alma , Bonadei Martina , Calvio Cinzia , Mattivi Fulvio , Carbonera Daniela
Published: September 2009

The aim of this study was the isolation and characterization of the culturable bacteria inhabiting the leaves of transgenic white poplars ( Populus alba L. ‘Villafranca’) engineered with the StSy gene for the production of resveratrol-like compounds. Resveratrol glucosides are available in small amounts from natural sources or by expensive chemical synthesis procedures. An alternative approach for the large-scale production of these relevant pharmaceuticals is the use of transgenic plants as bioreactors, although the occurrence of novel molecules in plants growing under field conditions might interfere, to some extent, with the associated microbial population. Both epiphytes and endophytes were isolated from the leaves of 2 StSy transgenic lines producing resveratrol glucosides and from an untransformed plant line grown in a greenhouse. Eleven isolates were recovered and classified as members of the genus Bacillus by 16S rDNA-based analysis. In addition, 2 isolates were classified as members of the Curtobacterium and Kocuria genera, respectively. Tolerance to hydrogen peroxide, UV-C, and paraquat was evaluated, as were the swimming and swarming motility of the leaf-associated bacteria. Interestingly, the isolates recovered from transgenic tissues showed the ability to withstand oxidative stress compared with isolates recovered from the untransformed poplar line. In vitro bioassays showed that trans-resveratrol inhibited both the swarming and swimming motilities in all the tested bacteria. The effects of trans-resveratrol on flagellin production, required for motility, were also investigated by immunoblot analysis.
Truncated hemoglobins in Frankia CcI3: effects of nitrogen source, oxygen concentration, and nitric oxide
Authors: Coats Vanessa , Schwintzer Christa R. , Tjepkema John D.
Published: September 2009

Frankia strain CcI3 produces 2 truncated hemoglobins, HbN and HbO. Using ion-exchange chromatography, we characterized the expression of the relative amounts of HbN and HbO in −N (nitrogen-fixing) cultures and +N (nitrogen-supplemented) cultures. The −N cultures maintained an approximately constant ratio of HbO to HbN throughout the life of the culture, with HbO constituting 80%–85% of the total hemoglobin produced. In contrast, in +N cultures, HbN was observed to increase over time and HbO decreased. Total hemoglobin as a fraction of total protein was approximately constant throughout the growth phase in −N cultures, while it decreased somewhat in +N cultures. Subjecting −N cultures to a NO generator resulted in increased production of HbN, relative to the controls. Nitrite accumulated in +N cultures, but not in −N cultures. This suggests that the greater amount of HbN in +N cultures might be due to NO produced by the reduction of nitrite. The effects of O2 concentration were determined in +N cultures. Cultures grown in 1% O2 produced about 4 times more HbO than cultures grown in 20% O2. Overall, these results provide evidence for a role of HbN in NO oxidation and for a role of HbO in adaptation to low oxygen concentrations.
Abundance of culturable versus viableEscherichia coliin freshwater
Authors: Servais Pierre , Prats Josué , Passerat Julien , Garcia-Armisen Tamara
Published: September 2009

Approved methods traditionally used for Escherichia coli enumeration in waters are culture-based. However, these methods can underestimate the E. coli abundance in aquatic systems because they do not take into account cells that remain viable but have lost the ability to grow in or on culture media. We investigated, in freshwater samples, the abundance of (i) culturable E. coli, enumerated by the most probable number microplate method and (ii) viable E. coli, estimated using a procedure called DVC–FISH, which couples fluorescent in situ hybridization (FISH) and a viability testing technique (direct viable count (DVC)). The ratio of culturable to viable E. coli was close to 1 in highly contaminated waters (samples with a high concentration of culturable E. coli), but decreased drastically for weakly contaminated samples. This indicates a large fraction of viable but nonculturable (VBNC) E. coli in the latter samples. Microcosm experiments showed that some environmental factors, such as nutrient scarcity and solar irradiation, could lead to the presence of a high proportion of VBNC E. coli.
Impaired renal calcium absorption in mice lacking calcium channel β3 subunits
Authors: Bernardo José F. , Magyar Clara E. , Sneddon W. Bruce , Friedman Peter A.
Published: September 2009

Transgenic mice lacking calcium channel β3 subunits (CaVβ3) were used to determine the involvement of a multimeric calcium channel in mediating stimulated renal calcium absorption. We measured the ability of calcium channel β3 subunit-null (CaVβ3−/−) and wild-type (CaVβ3+/+) mice to increase renal calcium absorption in response to the calcium-sparing diuretic chlorothiazide (CTZ). Control rates of fractional sodium excretion were comparable in CaVβ3−/− and CaVβ3+/+ mice and CTZ increased sodium excretion similarly in both groups. CTZ enhanced calcium absorption only in wild-type CaVβ3+/+ mice. This effect was specific for diuretics acting on distal tubules because both CaVβ3−/− and CaVβ3+/+ mice responded comparably to furosemide. The absence of β3 subunits resulted in compensatory increases of TrpV5 calcium channels, the plasma membrane Ca-ATPase, NCX1 Na/Ca exchanger protein, and calbindin-D9k but not calbindin-D28k. We conclude that TrpV5 mediates basal renal calcium absorption and that a multimeric calcium channel that includes CaVβ3 mediates stimulated calcium transport.
Hydrogen sulfide attenuates the pathogenesis of pulmonary fibrosis induced by bleomycin in rats
Authors: Fang Liping , Li Hong , Tang Chaoshu , Geng Bin , Qi Yongfen , Liu Xinmin
Published: September 2009

The present study investigated the role of the endogenous cystathionine γ-lyase (CSE) / hydrogen sulfide pathway in the pathogenesis of pulmonary fibrosis. Rats treated with intratracheal bleomycin were exposed either to the H2S donor NaHS or to saline. The results on day 7 showed that plasma H2S concentration and pulmonary CSE activity (H2S production rate) were significantly lower in rats treated with bleomycin and saline (fibrosis-alone) than in controls, whereas on day 28 plasma H2S concentration was higher and pulmonary CSE activity was the same as that of controls. The relative CSE mRNA level in the lungs of rats treated with bleomycin was significantly higher than control values on days 7 and 28. After exposure to NaHS, the total lung hydroxyproline content and the malondialdehyde (MDA) content were both significantly lower, with no difference observed between NaHS high-dose and low-dose treatments. Further, MDA formation stimulated by the free radical-generating system (FRGS) in vitro was lower in lung tissue incubated with NaHS than it was in tissue incubated with FRGS alone. These results suggest that NaHS administration ameliorated the pulmonary fibrosis induced by bleomycin in rats and that this protective effect of H2S may be mediated by its antioxidative action.
Baroreflex sensitivity is reduced in obese normotensive children and adolescents
Authors: Lazarova Zuzana , Tonhajzerova Ingrid , Trunkvalterova Zuzana , Brozmanova Andrea , Honzíková Natasa , Javorka Kamil , Baumert Mathias , Javorka Michal
Published: September 2009

Obesity is associated with autonomic nervous system dysfunction. The aim of the study was to evaluate baroreflex sensitivity, an indicator of autonomic nervous function, in 20 obese children and adolescents in comparison with 20 age- and sex-matched nonobese subjects. All subjects were examined in the supine position over a period of 50 min. Systolic blood pressure (SBP) and RR intervals were monitored continuously. Baroreflex sensitivity was assessed by cross-spectral analysis of SBP and RR interval oscillations (BRS index) and SBP and heart rate oscillations (BRSf index) within the low frequency range (0.04–0.15 Hz). Sensitivity was determined in 3 time intervals of 3 min each to evaluate changes during rest. The BRS index was significantly lower in obese children and adolescents than in the nonobese control group (p = 0.002). Significant changes in the BRS index over time (p = 0.004) were found only in nonobese subjects. In contrast, the BRSf index increased over time in both groups (p = 0.01), and no significant between-group difference was detected. In conclusion, obese children and adolescents show decreased resting baroreflex sensitivity with less variation compared with nonobese subjects. The BRS and BRSf indices appear to be only partially correlated.
Testing for the relative contribution of patch neighborhood, patch internal structure, and presence of predators and competitor species in determining distribution patterns of rodents in a fragmented landscape
Authors: Mortelliti A. , Amori G. , Annesi F. , Boitani L.
Published: September 2009

Factors affecting the distribution of species in fragmented landscapes, and their relative importance, are often unclear. Few studies have deliberately compared various hypotheses in relatively controlled conditions. Moreover, most studies to date have not incorporated false absences in their modeling. Following a multiple hypotheses testing framework, we tested the relative role of landscape structure, patch and neighborhood configuration, patch internal structure, presence or absence of predators, and presence or absence and abundance of potential competitor species on the occupancy patterns of three rodent species ( Myodes glareolus (Schreber, 1780), Apodemus flavicollis (Melchior, 1834), Apodemus sylvaticus (L., 1758)) in a highly fragmented landscape in Tuscany, central Italy. Distribution patterns and occupancy dynamics of the three rodent species were affected by patch and patch neighborhood characteristics, as well as the vicinity of other patches occupied by the species. However, we found no relevant effect of the surrounding landscape structure, patch internal structure, predator patch use, and abundance or distribution of potential competitor species. The observed spatial correlation between populations and the evidence of colonization or extinction events suggest that a metapopulation approach could provide a good framework for understanding the long-term dynamics of these populations.
Potential for adaptation-by-time in sockeye salmon (Oncorhynchus nerka): the interactions of body size and in-stream reproductive life span with date of arrival and breeding location
Authors: Doctor K. K. , Quinn T. P.
Published: September 2009

In salmonid fishes, the tendency to return to the natal site for breeding leads to reproductively isolated, locally adapted populations. In addition to this isolation-by-space, the heritability of breeding date can result in temporal segregation or isolation of breeding units. We examined the interaction between breeding location (spatial segregation) and arrival date (temporal segregation) for two fitness-related traits, reproductive life span and body size, of sockeye salmon ( Oncorhynchus nerka (Walbaum in Artedi, 1792)) in a small Alaskan stream. Analysis of data on tagged individuals over 9 years revealed that both males and females arriving early to the spawning grounds tended to spawn farther upstream than those arriving later, demonstrating the potential for segregation in time and space within the population. Both body length and reproductive life span also consistently varied with arrival date. Larger males and females entered the stream before smaller individuals, and individuals of both sexes that arrived early lived longer in the stream than those that arrived later. However, neither reproductive life span nor body size varied significantly with breeding location, indicating that the linkage between spatial and temporal structure in this breeding population is incomplete, and that segregation in time may currently be the dominant component of within-population structure.
False killer whale (Pseudorca crassidens) echolocation and acoustic disruption: implications for longline bycatch and depredation
Authors: Mooney T. A. , Pacini A. F. , Nachtigall P. E.
Published: September 2009

False killer whales ( Pseudorca crassidens (Owen, 1846)) depredate fish caught by the North Pacific pelagic longline fishery, resulting in loss of target species catch and the whales themselves becoming bycaught. This incidental take of false killer whales exceeds sustainable levels. In an effort to address a potential solution to reducing this depredation and bycatch, we tested an acoustic device designed to deter false killer whales from approaching longlines by reducing the whales’ echolocation performance capabilities. The device produced a series of complex, broadband signals (1–250 kHz) at high intensity levels (up to 182 dB). In the experiment, a trained false killer whale was asked to detect a target in the presence or absence of the acoustic device. Baseline performance capabilities were 95% correct responses. Initially, the device reduced the whale’s echolocation performance to chance levels. However, subsequent sessions demonstrated improvement in echolocation performance up to 85%. This improvement was likely a result of behaviorally adapting to the task and a decrease in the source level of the echolocation “disruptor”. The results underscore the challenges in using acoustic devices to reduce depredation and bycatch, and demonstrate the need for concern regarding anthropogenic noise levels and effects on odontocete echolocation capabilities.