bluuebunny/crossref_metadata_2025 huggingface dataset:
A Genetic Determinant in
Streptococcus gordonii
Challis Encodes a Peptide with Activity Similar to That of Enterococcal Sex Pheromone cAM373, Which Facilitates Intergeneric DNA Transfer
Authors: Vickerman M. M. , Flannagan S. E. , Jesionowski A. M. , Brossard K. A. , Clewell D. B. , Sedgley C. M.
Published: March 2010

Enterococcus faecalis
strains secrete multiple peptides representing different sex pheromones that induce mating responses by bacteria carrying specific conjugative plasmids. The pheromone cAM373, which induces a response by the enterococcal plasmid pAM373, has been of interest because a similar activity is also secreted by
Streptococcus gordonii
and
Staphylococcus aureus
. The potential to facilitate intergeneric DNA transfer from
E. faecalis
is of concern because of extensive multiple antibiotic resistance, including vancomycin resistance, that has emerged among enterococci in recent years. Here, we characterize the related pheromone determinant in
S. gordonii
and show that the peptide it encodes,
gordonii
-cAM373, does indeed induce transfer of plasmid DNA from
E. faecalis
into
S. gordonii
. The streptococcal determinant
camG
encodes a lipoprotein with a leader sequence, the last 7 residues of which represent the
gordonii
-cAM373 heptapeptide SVFILAA. Synthetic forms of the peptide had activity similar to that of the enterococcal cAM373 AIFILAS. The lipoprotein moiety bore no resemblance to the lipoprotein encoded by
E. faecalis
. We also identified determinants in
S. gordonii
encoding a signal peptidase and an Eep-like zinc metalloprotease (
lspA
and
eep
, respectively) similar to those involved in processing certain pheromone precursors in
E. faecalis
. Mutations generated in
camG
,
lspA
, and
eep
each resulted in the ablation of
gordonii
-cAM373 activity in culture supernatants. This is the first genetic analysis of a potential sex pheromone system in a commensal oral streptococcal species, which may have implications for intergeneric gene acquisition in oral biofilms.
Effect of cold water immersion on repeated cycling performance and limb blood flow
Authors: Vaile J , O'Hagan C , Stefanovic B , Walker M , Gill N , Askew C D
Published: March 2010

The purpose of the present study was to compare the effects of cold water immersion (CWI) and active recovery (ACT) on resting limb blood flow, rectal temperature and repeated cycling performance in the heat. Ten subjects completed two testing sessions separated by 1 week; each trial consisted of an initial all-out 35-min exercise bout, one of two 15-min recovery interventions (randomised: CWI or ACT), followed by a 40-min passive recovery period before repeating the 35-min exercise bout. Performance was measured as the change in total work completed during the exercise bouts. Resting limb blood flow, heart rate, rectal temperature and blood lactate were recorded throughout the testing sessions. There was a significant decline in performance after ACT (mean (SD) −1.81% (1.05%)) compared with CWI where performance remained unchanged (0.10% (0.71%)). Rectal temperature was reduced after CWI (36.8°C (1.0°C)) compared with ACT (38.3°C (0.4°C)), as was blood flow to the arms (CWI 3.64 (1.47) ml/100 ml/min; ACT 16.85 (3.57) ml/100 ml/min) and legs (CW 4.83 (2.49) ml/100 ml/min; ACT 4.83 (2.49) ml/100 ml/min). Leg blood flow at the end of the second exercise bout was not different between the active (15.25 (4.33) ml/100 ml/min) and cold trials (14.99 (4.96) ml/100 ml/min), whereas rectal temperature (CWI 38.1°C (0.3°C); ACT 38.8°C (0.2°C)) and arm blood flow (CWI 20.55 (3.78) ml/100 ml/min; ACT 23.83 (5.32) ml/100 ml/min) remained depressed until the end of the cold trial. These findings indicate that CWI is an effective intervention for maintaining repeat cycling performance in the heat and this performance benefit is associated with alterations in core temperature and limb blood flow.
Understanding the risk of hyperkalaemia in heart failure: role of aldosterone antagonism
Authors: Poggio Rosana , Grancelli Hugo O , Miriuka Santiago G
Published: March 2010

The risk of hyperkalaemia in patients with heart failure has increased in the past few years together with the evolution of pharmacological treatment for these patients. This significant change has been associated with the introduction of angiotensin converting enzyme (ACE) inhibitors, angiotensin II receptor blockers (ARBs), and aldosterone antagonists. High potassium concentrations in heart failure could lead to life threatening events, and therefore should be taken seriously. In this review we summarise the information about potassium homeostasis in heart failure and the current risk of developing potentially serious hyperkalaemia, particularly in association with the use of aldosterone antagonists.
Liver disease in pregnancy
Authors: Mackillop Lucy , Williamson Catherine
Published: March 2010

Pregnancy is a time of great maternal physiological and metabolic changes. This affects the biochemical and haematological parameters used in the assessment of liver disease, and it is important to appreciate the different reference ranges in pregnancy to facilitate recognition of liver disorders in pregnancy. Due to the increased physiological and metabolic stress of pregnancy, liver disorders that have previously been subclinical may become symptomatic—for example, primary biliary cirrhosis. Gallstone disease is a common problem in women of childbearing age, and pregnancy promotes their formation. The viral hepatidides constitute a huge disease burden worldwide and the pregnant state confers particular concerns for the mother and her baby. In particular, hepatitis E has a predilection for the pregnant population and confers a particularly poor prognosis. In addition certain pregnancy specific disorders—for example, haemolysis, elevated liver enzymes, low platelets syndrome, acute fatty liver of pregnancy, and obstetric cholestasis—affect primarily the liver. It is important to know how to diagnose and manage these conditions and distinguish them from non-pregnancy specific conditions as this will change the timing and management of affected women and their babies, some of whom can be seriously ill. We propose an approach to the investigation and management of the pregnant patient with abnormal liver function tests.
Teaching cause-of-death certification: lessons from international experience
Authors: Aung Eindra , Rao Chalapati , Walker Sue
Published: March 2010

Background and objective

The accuracy of cause-of-death statistics substantially depends on the quality of cause-of-death information in death certificates, primarily completed by medical doctors. Deficiencies in cause-of-death certification have been observed across the world, and over time. Despite educational interventions targeted at improving the quality of death certification, their intended impacts are rarely evaluated. This review aims to provide empirical evidence that could guide the modification of existing educational programmes, or the development of new interventions, which are necessary to improve the capacity of certifiers as well as the quality of cause-of-death certification, and thereby, the quality of mortality statistics.

Design

A literature review using keywords: death; certification; education/training.

Data sources

The primary search through PubMed. Reference lists in individual articles from the primary search and also manual searching of other databases such as Google Scholar and OpenDOAR.

Eligibility criteria for selecting studies

Evaluation studies which assessed educational interventions for medical students and doctors on correct completion of death certificates.

Results

All educational interventions identified in this review improved certain aspects of death certification although the statistical significance of evaluation results varies with the type of intervention: printed educational material alone being the intervention with the least educational impact and interactive workshops being the most effective intervention.

Conclusions

Pragmatic education on best practice for cause-of-death certification is a basic step to ensure accurate information for each individual case, leading to the production of high quality mortality statistics for epidemiology, public health policy and research. Development of new educational interventions or modification of existing programmes should be based on evidence of the benefits from current and past interventions provided under varying circumstances.
Neuromyelitis optica: an overview
Authors: Nandhagopal R , Al-Asmi Abdullah , Gujjar Arunodaya R
Published: March 2010

Neuromyelitis optica (NMO) is a relapsing inflammatory disorder of the central nervous system that closely resembles multiple sclerosis. This review discusses recent understanding of NMO with reference to epidemiology, clinical spectrum, immunopathology, diagnostic evaluation, clinical course and management. Within the clinical spectrum of NMO, the classical form (with relapsing opticomyelitis) and limited forms (either recurrent myelitis or optic neuritis), as well as its association with other autoimmune disorders, have been recognised in recent years. Further, symptomatic or asymptomatic cerebral lesions may be present, and such brain lesions do not necessarily exclude the diagnosis. In the appropriate clinical context, the diagnosis is supported by longitudinally extensive myelitis on spinal MRI. Overwhelming evidence strongly indicates that aquaporin 4 antibody has a pathogenetic role in the development of NMO and serves as a useful diagnostic and prognostic marker. Detection of this autoantibody has led to the categorisation of NMO as an autoimmune channelopathy. NMO can be distinguished from multiple sclerosis by a combination of clinical, radiological and laboratory studies. However, the nosological position of Asian opticospinal multiple sclerosis is not settled. In NMO, acute attacks usually result in moderate to severe functional impairment, and, in the absence of a secondary progressive course (unlike relapsing–remitting multiple sclerosis), prevention of relapses is of crucial importance in the management of the disease. Indeed, relapse prevention with long-term immunosuppressive medication remains the cornerstone of therapy in this otherwise debilitating disease!
Nuclear DNA content variation associated with muscle fiber hypertrophic growth in decapod crustaceans
Authors: Jimenez Ana Gabriela , Kinsey Stephen T. , Dillaman Richard M. , Kapraun Donald F.
Published: March 2010

We tested the hypothesis that hypertrophic muscle growth in decapod crustaceans is associated with increases in both the number of nuclei per fiber and nuclear DNA content. The DNA-localizing fluorochrome DAPI (4′,6-diamidino-2-phenylindole) and chicken erythrocyte standards were used with static microspectrophotometry and image analysis to estimate nuclear DNA content in hemocytes and muscle fibers from eight decapod crustacean species: Farfantepenaeus aztecus , Palaemonetes pugio , Panulirus argus , Homarus americanus , Procambarus clarkii , Cambarus bartonii , Callinectes sapidus , and Menippe mercenaria . Mean diploid (2C) values in hemocytes ranged from 3.6 to 11.7 pg. Hemocyte 2C estimates were used to extrapolate ploidy level in the multinucleated skeletal muscle tissue of juvenile and adult animals. Across all species, mean muscle fiber diameters from adult animals were significantly larger than those in juveniles, and nuclear domains were greater in larger fibers. The number of nuclei per fiber increased with increasing fiber size, as hypothesized. Maximum nuclear DNA content per species in muscle ranged from 4C to 32C, consistent with endopolyploidy. Two patterns of body- and fiber-size-dependent shifts in ploidy were observed: four species had a significantly higher ploidy in the larger fibers of adults, while three species exhibited a significantly lower ploidy in adults than in juveniles. Thus, across species, there was no systematic relationship between nuclear domain size and nuclear DNA content.
Application of ARPS–CMAQ modeling system for urban air pollutant emission abatementA paper submitted to the Journal of Environmental Engineering and Science.
Authors: Zhao X. Y. , Cheng S. Y. , Li J. B. , Wang H. Y. , Guo X. R.
Published: March 2010

A coupled advanced regional prediction system – community multi-scale air quality (ARPS–CMAQ) modeling system was applied to develop an abatement strategy for air pollutant emission in the Handan region of the northern China. The system was evaluated by comparing the simulated concentrations of particulate matter less than 10 µm (PM10) with the observed results in the study area during the four representative months in 2005. A process of planning emission abatement was applied by gradually reducing PM10 emissions from the original GIS-based emission inventory until a modeling emission scenario was obtained under which the simulated PM10 concentrations could satisfy the desired air quality objective. The air quality objective was represented by an air quality guideline satisfaction ratio of 80% to reach a daily PM10 concentration of 150 µg/m3 after the year 2010. The modeling system and results could provide sound basis for decision makers to develop an effective air quality management strategy.
Vers une gestion durable et intégrée des eaux pluviales : Application des propositions d’action publique au Québec
Authors: Fuamba Musandji , Walliser Thomas , Daynou Mathurin , Rousselle Jean , Rivard Gilles
Published: March 2010

Le rejet non contrôlé des eaux pluviales est une importante cause de la dégradation de la qualité de l’environnement, notamment au niveau de la nappe phréatique, des milieux récepteurs et des habitations. L’analyse de l’état actuel de la gestion des eaux pluviales au Québec montre l’existence de certaines lacunes dans la conception des réseaux de drainage urbain, avec des exigences et des attentes de plus en plus larges de la part des citoyens ainsi que des nouveaux défis associés au développement durable. Il devient donc urgent de mettre en place une nouvelle approche pour gérer de manière durable et intégrée la question du drainage urbain dans le contexte spécifique québécois. Le présent article offre une revue succincte de la littérature, une analyse exhaustive des pratiques de gestion optimale (PGO) applicables pour le Québec et une stratégie de contrôle des volumes de ruissellement des eaux pluviales. Il décrit huit propositions d’action publique élaborées pour une gestion durable et intégrée de ces eaux au Québec. Une démarche méthodologique sommaire en neuf étapes y est également présentée pour aider les acteurs du milieu à appliquer les propositions suggérées.
Spring ammonium maximum in the mid-depth layer of Lake Biwa, JapanA paper submitted to the Journal of Environmental Engineering and Science.
Authors: Tanaka Lidia L. , Ban Syuhei , Kumagai Michio
Published: March 2010

The spatio-temporal variation in ammonium-nitrogen (NH4-N) profiles was investigated in the North Basin of Lake Biwa in 2002, 2004, and 2005 and in the Uso River in 2004–2005. The in-lake concentration of NH4-N was low throughout the water column, except between late April and mid-June, when a distinct maximum developed between 10 and 25 m depth, in and below the thermocline. This layer extended offshore from both east and west boundaries to the center of the lake. By comparing water temperature estimates from the Uso River with water temperatures measured in the lake, we hypothesize that cooler water intrudes into the lake during the night at depths between 8 and 28 m. The intrusions are likely more pronounced from mid to late May when the NH4-N concentration in the Uso River is highest. This suggests that riverine input is an important factor in the formation of the mid-depth ammonium maximum in Lake Biwa. These findings underscore the importance of fluvial discharge and lateral transport of dissolved nutrients in temperate lakes.
Strength of welded joints under combined shear and out-of-plane bending
Authors: Kwan Y. K. , Gomez I. R. , Grondin G. Y. , Kanvinde A. M.
Published: March 2010

An experimental and analytical research program was conducted with the objective of investigating the response of welded joints loaded under combined out-of-plane bending and shear. A database of test results, including 60 tests from the University of California in Davis, eight tests from an early research program at the University of Alberta in Edmonton, and 24 tests from Université Laval in Ste.-Foy, was used to evaluate several strength prediction models and the current North American design approaches. This work was complemented by a reliability analysis to assess the level of safety provided by these design approaches. It was determined that both the Canadian Institute of Steel Construction (CISC) and the American Institute of Steel Construction (AISC) approaches provide remarkably conservative predictions of the test results, especially for cases where the welded plate thickness is large. Although a modified version of an approach proposed by earlier investigators in 1972 and based on the method of instantaneous centre of rotation provides an accurate prediction of test results, a simpler strength calculation model that does not require an iterative approach is proposed as a substitute for the current design approaches. The proposed approach provides the desired level of safety for the design of welded joints loaded in shear and out-of-plane bending.
Comparison of experienced and novice cost estimator behaviors in information pull and push methods
Authors: Kiziltas Semiha , Akinci Burcu , Gonzalez Cleotilde
Published: March 2010

Construction cost estimators mainly use analogy-based decision-making processes while estimating activity production rates in new bids. They need to search information items that will help them in understanding the differences and similarities between the current and previously completed projects to select appropriate production rates and make necessary adjustments to the selected production rates. The objective of the study is to understand the effect of information pull–push methods on the behaviors of cost estimators when they refer to information items from historical sources in structuring their decisions. Eleven experienced estimators and 11 novice civil engineering candidates participated in an experiment involving card games, which simulated the information pull method, and in another experiment involving a prototype system, which simulated the information push method. Results showed that novices can behave like experienced estimators when information relevant to a decision is pushed to them. This result has implications for the design of information systems. Results show that it is possible to improve the estimates of novice estimators by providing them with decision support tools designed with the right information delivery method for their level of experience.
Development of seismic force modification factors for cold-formed steel strap braced walls
Authors: Comeau G. , Velchev K. , Rogers C.A.
Published: March 2010

Seismic force modification factors to be used in conjunction with the National building code of Canada are recommended for two cold-formed steel (CFS) concentrically braced frame categories; limited ductility (LD) (Rd = 2.0, Ro = 1.3, height limit 20 m) and conventional construction (CC) (Rd = 1.25, Ro = 1.3, height limit 15 m, not permitted in high seismic zones). Nonlinear time history dynamic analyses of multi-storey CFS framed structures were carried out following an approach adopted from the Federal Emergency Management Agency (FEMA) P695 on the quantification of building seismic performance factors. Input earthquake records (both synthetic and recorded) were scaled to the site specific uniform hazard spectra for Vancouver, Calgary, Québec City, and Halifax. The calculated inelastic storey drifts and the failure probabilities from the FEMA P695 incremental dynamic analysis procedure showed that the Canadian seismic design procedures for type LD and CC strap braced walls in the American Iron and Steel Institute (AISI) S213 North American CFS lateral design standard are acceptable for the multi-storey buildings that were analysed.
Évaluation des effets d’une lampe à cathode creuse pulsée à courant variable sur les interférences spectrales de l’arsenic dans le dosage du cadmium par spectrophotométrie d’absorption atomiqueArticle envoyé à la Revue du génie et de la science de l'environnement.
Authors: Waterlot C. , Douay F.
Published: March 2010

Les teneurs en cadmium de solutions aqueuses contaminées à des teneurs croissantes en arsenic ont été mesurées à l’aide d’un spectrophotomètre d’absorption atomique équipé d’une flamme et d’un four électrothermique. Pour chacune des techniques d’atomisation, a été évaluée une méthode de correction du bruit de fond basée sur le renversement de spectre et connue sous le nom de « high-speed self-reversal method », au regard d’une autre méthode plus couramment utilisée ne nécessitant qu’une lampe au deutérium et une lampe au cadmium. En comparaison avec cette méthode, les résultats ont montré que le mode de correction basé sur le renversement spectral via l’utilisation d’une lampe au cadmium à cathode creuse pulsée à courant variable était une méthode plus appropriée pour corriger les phénomènes d’interférences causés par l’arsenic (As) lors du dosage du cadmium (Cd). Il a été établi que cette méthode permettait de s’affranchir des interférences de l’arsenic pour des ratios [As]/[Cd] inférieurs à 50 000.
Effect of mineral admixture on resistance to sulphuric and hydrochloric acid attacks in self-compacting concrete
Authors: Siad H. , Mesbah H. A. , Khelafi H. , Kamali-Bernard S. , Mouli M.
Published: March 2010

This paper presents a detailed experimental investigation of the acid resistance of economical self-compacting concrete (SCC) prepared with natural pozzolan, immersed for up to 12 weeks in sulphuric acid (H2SO4) and hydrochloric acid (HCl) solutions. The results are compared with those from a control concrete and other SCCs prepared with fly ash and limestone filler. The different factors considered in this study were the effect of mineral admixture type and the strength classes (30, 50, and 70 MPa) of the concrete specimens. In total, 12 formulations were tested. Mass and compressive strength losses are the main properties investigated. Scanning electron microscope (SEM) and X-ray diffraction (XRD) analyses were used to better understand the kinetics of deterioration of each type of concrete. The results show the positive influence of natural pozzolan on the behaviour of SCC under both sulphuric and hydrochloric acid mediums.
Data mining-based adaptive regression for developing equilibrium speed–density relationships
Authors: Sun Lu , Yang Jun , Mahmassani Hani , Gu Wenjun , Kim Bum-Jin
Published: March 2010

In this paper, we developed a methodological framework to deal with traffic-stream modeling based on data mining, steepest-ascend algorithm, and genetic algorithm. The new method is adaptive in nature and has a greater flexibility and generality compared with existing methods. It provides an optimum overall fitting of the observed data. Specifically, the advantages of adaptive regression are that (1) knot positions and model parameters are estimated optimally and simultaneously using genetic algorithm, and presetting of knot positions can be performed in terms of either density or speed; (2) the method is automatic and data driven, and it will always find out the best fitting model to site-dependent actual traffic data; and (3) the user has a great flexibility to specify the degree-model continuity and to define and add new basis functions that are parsimonious and fit better into the traffic data in some regime of speed–density relation. The proposed method and developed computer software package MiningFlow will be beneficial to traffic operations and traffic simulation.
Dynamic response of transmission lines guyed towers under wind loading
Authors: Gani F. , Légeron F.
Published: March 2010

The importance of the dynamic response of guyed towers for transmission lines (TLs) under wind loading is evaluated in this article. The objective is to verify if the simplified static-equivalent approach provided in the current TL codes is sufficient for this type of flexible tower. As a comparison, transient dynamic (TD) analyses were performed. Two different guyed tower configurations were investigated: (i) the direct current (DC) line and (ii) the alternating current (AC) line. Loading cases considering bare and iced TL structures were studied. It was found that, depending on the guyed tower configuration and the loading case, the static-equivalent approach may underestimate the possible dynamic response. In addition, a simplified method that allows a better prediction of the dynamic effects is proposed.
Performance of horizontal subsurface flow constructed wetland in the removal of tanninsA paper submitted to the Journal of Environmental Engineering and Science.
Authors: Njau K.N. , Renalda M.
Published: March 2010

A horizontal subsurface flow constructed wetland (HSSFCW) was employed to remove tannins from the effluent of a tannins extracting company. Two HSSFCW cells with hydraulic retention time (HRT) of 9 d and packed with limestone were used. One cell without macrophytes was used as a control, while the second cell was planted with Phragmites mauritianus . Results indicated that HSSFCW was capable of treating tannin wastewater that has been seeded with primary facultative pond sludge. Tannins and chemical oxygen demand (COD) removal efficiency of 95.9% and 90.6% with outlet concentration of 27 mg/L and 86 mg/L, respectively, were obtained in the planted cell; while the tannins and COD removal efficiency of 91.1% and 89.5% with outlet concentration of 57 mg/L and 96 mg/L, respectively, were obtained in the control cell.
Development and application of efficient methods for the forward propagation of epistemic uncertainty and sensitivity analysis within complex broad-scale flood risk system modelsThis article is one of a selection of papers published in this Special Issue on Hydrotechnical Engineering.
Authors: Gouldby B. P. , Sayers P. B. , Panzeri M. C. , Lanyon J. E.
Published: March 2010

Increasingly, an understanding of flood risk across regions and nations, and an ability to explore how these might change in time, is seen as a prerequisite to effective and efficient flood risk management. In response, specific flood risk analysis methods have been developed that are both accurate and fast to run. Although widely acknowledged as desirable, it has not previously been possible to quantify the uncertainty associated with the assessed flood probability, consequence, or risk. To help overcome this deficiency, an efficient method for the propagation of epistemic uncertainties through large-scale flood risk system models has been developed and trialed for three pilot catchments. The approach is allied to an efficient sensitivity analysis that enables the influence of individual uncertainties on the output quantity of risk to be isolated, enabling future research, development, and data-gathering efforts to be focused.
Combined sewer overflow over an oblique weir at Rat Creek in Edmonton, Alberta
Authors: Valentine Elizabeth , Kronebusch Kurt , Zhu David Z. , Rajaratnam N. , Lodewyk Sid , Cairns John , Chan Steven , Zhou Fayi
Published: March 2010

Oblique weirs are commonly used in urban drainage systems to remove excess flow from a sewer, in particular, a combined sewer system that has limited conveyance capacity. It is important to understand the hydraulics of these weirs to properly monitor the amount of the overflows as well as to design and improve sewer systems. The Rat Creek structure in Edmonton, Alberta, is a combined sewer overflow structure with a weir at an oblique alignment to the centerline of the sewer. A physical model study of the structure was conducted. The results show that both the approach flow conditions and the chamber geometry can significantly affect the hydraulic performance of the weir and invalidate the application of standard weir equations. A unique flow regime with a linear head–discharge rating curve was observed. The effects of modifying the weir and the hanging baffle wall downstream of the weir were also studied and reported. The results of this case study help to improve the understanding of the hydraulics of oblique weirs in sewer systems.
Mean-field study of the synergic effect of the CO–NO reaction on a heterogeneous substrate of interconnected sectors
Authors: Cortés Joaquín , Valencia Eliana
Published: March 2010

A mean-field theory study is made of the behaviour of a kinetic model of the reduction reaction of NO by CO catalyzed by a surface with simple heterogeneity consisting of two interconnected sectors that differ in their NO dissociation activation energy. A synergistic effect is manifested in the activity, apparent activation energy, and reaction order of the system. This situation, analogous to that observed in the literature in the case of a heterogeneous catalytic particle, is used in the paper to analyze a real case of a bimetallic catalyst.
Effect of culture media and pH on the biomass production and biocontrol efficacy of aMetschnikowia pulcherrimastrain to be used as a biofungicide for postharvest disease control
Authors: Spadaro D. , Ciavorella A. , Dianpeng Z. , Garibaldi A. , Gullino M. L.
Published: March 2010

Few strains of Metschnikowia pulcherrima (Pitt) M.W. Miller are under development for control of postharvest pathogens on fruit. A substrate was developed to optimize the biomass production of M. pulcherrima strain BIO126. Different complex nutrient sources, with or without pH control, were tested. Growth in yeast extract provided at concentrations ≥30 g·L–1yielded the highest biomass. The addition of two carbon sources, d-mannitol and l-sorbose, at 5 g·L–1each, significantly improved yeast growth. The greatest amount of yeast growth occurred when pH values of the medium ranged from 5.0 to 7.5. A combination of yeast extract, d-mannitol, and l-sorbose (YEMS), probably with diauxic utilization, showed a synergistic effect, widening the exponential phase (maximum specific growth rate of 0.45 h–1) and increasing the final cell number (1.5 × 109cells·mL–1) and dry biomass (6.0 g·L–1) in well-controlled batch fermentation. In efficacy trials on ‘Golden Delicious’ apples, M. pulcherrima grown in YEMS effectively reduced incidence and severity of Botrytis cinerea (51.1% and 70.8%, respectively) and Penicillium expansum (41.7% and 14.0%, respectively). Also on ‘Gala’ apples, the best reduction of grey and blue mould incidence was obtained with cells grown in YEMS (58.1% and 50.5%, respectively).
Monitoring the impact of hydrocarbon contamination and nutrient addition on microbial density, activity, and diversity in soil
Authors: Taok Mira , Mundo Joana , Sarde Claude Olivier , Schoefs Olivier , Cochet Nelly
Published: March 2010

The development of optimal in situ bioremediation strategies requires a better knowledge of their impact on the soil microbial communities. We have evaluated the impact of hexadecane contamination and different nutrient amendments on soil microbial density and activity. Microbial density was measured via total DNA quantification, and microbial activity via respiration and RNA variation. The RNA/DNA ratio was also determined, as it is a potential indicator of microbial activity. PCR-amplified 16S rRNA genes were cloned and sequenced to analyze the diversity of bacterial communities. Nutrient addition significantly increased respiration and DNA and RNA concentrations in contaminated soil, indicating a limitation of degradation and growth by the availability of nitrogen and phosphorus in unamended microcosms. Hexadecane treatment slightly affected the diversity of the bacterial community, while it was dramatically reduced by nutrient treatments, particularly the addition of nitrogen and phosphorus. Microbial community composition was also altered with the enrichment of populations related to Nocardia in bioremediated soils, while uncultured Proteobacteria were mostly detected in uncontaminated soil.
Removal of human enteric viruses and indicator microorganisms from domestic wastewater by aerated lagoons
Authors: Locas Annie , Martinez Veronica , Payment Pierre
Published: March 2010

Aerated lagoons offer a low-cost and simple approach to treating domestic wastewater in small municipalities. The objective of the current study was to evaluate, for each cell in the lagoons, the removal of indicator microorganisms and human enteric viruses under warm (summer) and cold (early spring) conditions. The two sites are located in southwest Quebec, Canada. Samples were assayed for thermotolerant coliforms, enterococci, Clostridium perfringens , somatic and male-specific coliphages, and culturable human enteric viruses (HEV). The results show higher removal under warm ambient conditions for all microorganisms. Thermotolerant coliforms and enterococci were removed to a greater extent than C. perfringens and HEV. HEV removal was only observed in warm ambient conditions. The removal of coliphages was different from the observed removal of HEV. The use of coliphages as surrogates for HEV has been proposed, but this does not seem appropriate for aerated lagoons, as the removal of coliphages overestimates the removal of HEV. Given the low observed removal of HEV during this study, the effluents remain a significant source of pathogens that can affect drinking water treatment plants drawing their raw water from receiving streams. Ultraviolet disinfection of treated wastewater effluent is a possible solution.
Calcium and the damage pathways in muscular dystrophyThis article is one of a selection of papers published in this special issue on Calcium Signaling.
Authors: Allen David G. , Gervasio Othon L. , Yeung Ella W. , Whitehead Nicholas P.
Published: March 2010

Duchenne muscular dystrophy (DMD) is a severe muscle-wasting disease caused by the absence of the cytoskeletal protein dystrophin. Experiments on the mdx mouse, a model of DMD, have shown that mdx muscles are particularly susceptible to stretch-induced damage. In this review, we discuss evidence showing that a series of stretched contractions of mdx muscle fibres causes a prolonged increase in resting intracellular calcium concentration ([Ca2+]i). The rise in [Ca2+]iis caused by Ca2+entry through a class of stretch-activated channels (SACNSC) for which one candidate gene is TRPC1. We review the evidence for activation of SACNSCin muscle by reactive oxygen species (ROS) and suggest that stretch-induced ROS production is part of the pathway that triggers increased channel activity. When the TRPC1 gene was transfected into C2 myoblasts, expression occurred throughout the cell. Only when the TRPC1 gene was coexpressed with caveolin-3 did the TRPC1 protein express in the membrane. When TRPC1 was expressed in the membrane, it could be activated by ROS to produce Ca2+entry and this entry was inhibited by PP2, an inhibitor of src kinase. These results suggest that stretched contractions activate ROS production, which activates src kinase. Activity of this kinase causes opening of SACNSCand allows Ca2+entry. This pathway appears to be a significant cause of muscle damage in DMD.
Nitric oxide and calcium signaling regulate myocardial tumor necrosis factor-α expression and cardiac function in sepsisThis article is one of a selection of papers published in this special issue on Calcium Signaling.
Authors: Zhang Ting , Feng Qingping
Published: March 2010

Myocardial tumor necrosis factor-α (TNF-α), a proinflammatory cytokine, is a critical inducer of myocardial dysfunction in sepsis. The purpose of this review is to summarize the mechanisms through which TNF-α production is regulated in cardiomyocytes in response to lipopolysaccharide (LPS), a key pathogen-associated molecular pattern (PAMP) in sepsis. These mechanisms include Nox2-containing NAD(P)H oxidase, phospholipase C (PLC)γ1, and Ca2+signaling pathways. Activation of these pathways increases TNF-α expression via activation of extracellular signal-regulated kinases 1 and 2 (ERK1/2) and p38 mitogen-activated protein kinase (MAPK). Conversely, activation of c-Jun NH2-terminal kinase 1 (JNK1) negatively regulates TNF-α production through inhibition of ERK1/2 and p38 MAPK activity. Interestingly, endothelial nitric oxide synthase (eNOS) promotes TNF-α expression by enhancing p38 MAPK activation, whereas neuronal NOS (nNOS) inhibits TNF-α production by reducing Ca2+-dependent ERK1/2 activity. Therefore, the JNK1 and nNOS inhibitory pathways represent a “brake” that limits myocardial TNF-α expression in sepsis. Further understanding of these signal transduction mechanisms may lead to novel pharmacological therapies in sepsis.
eNOS phosphorylation and translocation are altered in male but not female mice by increased activation of the Gαq protein
Authors: Ruiz-Holst C. , Bölck B. , Ghanem A. , Tiemann K. , Brokat S. , Regitz-Zagrosek V. , Bloch W. , Schwinger Robert H.G. , Brixius K.
Published: March 2010

Little is known about sex-dependent physiological and pathophysiological differences in cardiac endothelial nitric oxide synthase (eNOS) expression and activation. Therefore, we investigated cardiac morphology and eNOS protein expression, including its translocation-dependent activation and phosphorylation, in cardiac tissue of male and female wild-type mice and transgenic heart-failure mice having a cardiac-specific, 5-fold overexpression of the Gαqprotein. In addition, we measured calcineurin protein expression. Heart-to-body weight ratio was increased in Gαqmice. Female wild-type mice showed higher eNOS protein expression and activation (translocation and phosphorylation) than did wild-type males. In cardiac tissue of Gαqmice, these sex-dependent differences remained or were enhanced. Protein expression of the catalytic subunit calcineurin A, which has been shown to dephosphorylate eNOS, was higher in wild-type males than in wild-type females. These differences were increased in the Gαqmice model. We conclude that sex differences exist in cardiac eNOS protein expression and phosphorylation. Increased activation of the Gαqprotein appears to alter eNOS protein expression and phosphorylation only in males.
Diaphragm tension reduced in dystrophic mice by an oxidant, hypochlorous acid
Authors: Lafoux Aude , Divet Alexandra , Gervier Pascal , Huchet-Cadiou Corinne
Published: March 2010

In dystrophin-deficient skeletal muscle cells, in which Ca2+ homeostasis is disrupted and reactive oxygen species production is increased, we hypothesized that hypochlorous acid (HOCl), a strong H2O2-related free radical, damages contractile proteins and the sarcoplasmic reticulum. The aim of the present study was to investigate the effects of exposure to oxidative stress, generated by applying HOCl (100 µmol/L and 1 mmol/L), on the contractile function and sarcoplasmic reticulum properties of dystrophic mice. Experiments were performed on diaphragm muscle, which is severely affected in the mdx mouse, and the results were compared with those obtained in healthy (non-dystrophic) mice. In Triton-skinned fibres from C57BL/10 and mdx mice, 1 mmol/L HOCl increased myofibrillar Ca2+ sensitivity, but decreased maximal Ca2+-activated tension. In the presence of HOCl, higher concentrations of MgATP were required to produce rigor tensions. The interaction between HOCl and the Ca2+ uptake mechanisms was demonstrated using saponin-skinned fibres and sarcoplasmic reticulum vesicles. The results showed that HOCl, at micromolar or millimolar concentrations, can modify sarcoplasmic reticulum Ca2+ uptake and that this effect was more pronounced in diaphragm muscle from mdx mice. We conclude that in dystrophic diaphragm skeletal muscle cells, HOCl activates a cellular pathway that leads to an increase in the intracellular concentration of Ca2+.
Nongenomic inhibition of coronary constriction by 17β-estradiol, 2-hydroxyestradiol, and 2-methoxyestradiol
Authors: Hill Brent J.F. , Gebre Senetibeb , Schlicker Bonnie , Jordan Renée , Necessary Sean
Published: March 2010

The cardioprotective effects of 17β-estradiol (E2) in women are hypothesized to be partially mediated by the E2 metabolites 2-hydroxyestradiol (2-HOE) and 2-methoxyestradiol (2-MeOH). Therefore, the purpose of our study was to determine the acute effects of E2, 2-HOE, and 2-MeOH on inhibition of coronary arterial constriction. Right coronary arteries obtained from breeding sows were cut into 4 mm rings and suspended in organ baths. Incubation of the rings with E2, 2-HOE, and 2-MeOH (10 µmol/L) for 60 min attenuated a subsequent KCl-induced contraction by approximately 50%. The protein synthesis inhibitor cycloheximide and the estrogen receptor antagonists ICI 182780 and tamoxifen did not affect the attenuation. Moreover, E2, 2-HOE, and 2-MeOH antagonized the contraction induced by the vasospasm agonist endothelin-1 (0.1 µmol/L) by approximately 36%. When the L-type Ca2+channel blocker nifedipine was added at the conclusion of the experiment, no additional contractile attenuation was present. Our results suggest that E2, 2-HOE, and 2-MeOH demonstrate a similar nongenomic inhibition of agonist-induced extracellular Ca2+-dependent contractions.
Antidiabetic activity of aqueous bark extract ofCassia glaucain streptozotocin-induced diabetic rats
Authors: Salahuddin Md. , Jalalpure Sunil S. , Gadge Navneet B.
Published: March 2010

The leaves and bark of Cassia glauca Lam., a glabrous tree in the family Fabaceae, are used in folk medicine for the treatment of diabetes. The aim of this study was to investigate the antidiabetic activity of the aqueous extract of C. glauca bark. The various parameters that were studied in treated or untreated normoglycemic and STZ-induced diabetic rats included the effect of the aqueous extract on oral glucose tolerance, fasting blood glucose, body weight, serum lipids, liver glycogen, serum insulin, and glycosylated haemoglobin. Oral administration of the aqueous extract of C. glauca bark at a dose of 500 mg/kg significantly reduced the effect of external glucose load. In a chronic treatment model, aqueous extract and glibenclamide (0.25 mg/kg) were administered for 21 days. At the end of the treatment, there was a significant increase in liver glycogen, serum insulin, and HDL cholesterol for both treatments. A significant decrease in fasting blood glucose, glycosylated haemoglobin, total cholesterol, and serum triglycerides was also observed. The body weights of the animals were observed to be consistent throughout the study. The findings showed the significant antidiabetic potential of the extract in ameliorating the diabetic condition in the diabetic rats. No significant activity was found in the normoglycemic rats.
Do prostaglandins modulate renal haemodynamic effects of endothelin-1 in conscious lambs?
Authors: Ebenezar Kumar Kesavarao , Sharbaf Fatemah Ghane , Qi Wei , Smith Francine Gabriel
Published: March 2010

To test the hypothesis that vasodilatory prostaglandins buffer the renal vasoconstrictor effects of endothelin-1 (ET-1) early in life, renal haemodynamic responses to ET-1 were measured in 2 groups of conscious, chronically instrumented lambs at 1–2 weeks of age (group I, n = 11) and 6 weeks of age (group II, n = 10). Lambs were pretreated with vehicle or 1 mg·kg–1 indomethacin, a nonselective cyclooxygenase inhibitor, and renal haemodynamic effects were measured continuously for 1 min before (control) and 5 min after intra-arterial injection of 250 ng·kg–1 ET-1. In group II lambs, there was a marked decrease in renal blood flow (RBF) and renal vascular conductance (RVC) elicited by ET-1 administration, as we have previously described. This response was not altered by vehicle or indomethacin pretreatment. In group I lambs, there was an initial increase but no decrease in RBF and RVC elicited by ET-1 administration, as we have previously described, and this response was also not altered by either vehicle or indomethacin. These results suggest that endogenously produced prostaglandins do not appear to modulate the renal haemodynamic effects of ET-1 in conscious lambs during postnatal maturation.
The bioclimatic envelope of the wolverine (Gulo gulo): do climatic constraints limit its geographic distribution?
Authors: Copeland J. P. , McKelvey K. S. , Aubry K. B. , Landa A. , Persson J. , Inman R. M. , Krebs J. , Lofroth E. , Golden H. , Squires J. R. , Magoun A. , Schwartz M. K. , Wilmot J. , Copeland C. L. , Yates R. E. , Kojola I. , May R.
Published: March 2010

We propose a fundamental geographic distribution for the wolverine ( Gulo gulo (L., 1758)) based on the hypothesis that the occurrence of wolverines is constrained by their obligate association with persistent spring snow cover for successful reproductive denning and by an upper limit of thermoneutrality. To investigate this hypothesis, we developed a composite of MODIS classified satellite images representing persistent snow cover from 24 April to 15 May, which encompasses the end of the wolverine’s reproductive denning period. To investigate the wolverine’s spatial relationship with average maximum August temperatures, we used interpolated temperature maps. We then compared and correlated these climatic factors with spatially referenced data on wolverine den sites and telemetry locations from North America and Fennoscandia, and our contemporary understanding of the wolverine’s circumboreal range. All 562 reproductive dens from Fennoscandia and North America occurred at sites with persistent spring snow cover. Ninety-five percent of summer and 86% of winter telemetry locations were concordant with spring snow coverage. Average maximum August temperature was a less effective predictor of wolverine presence, although wolverines preferred summer temperatures lower than those available. Reductions in spring snow cover associated with climatic warming will likely reduce the extent of wolverine habitat, with an associated loss of connectivity.
Population substructure of harbor seals (Phoca vitulina richardsi) in Washington State using mtDNA
Authors: Huber H. R. , Jeffries S. J. , Lambourn D. M. , Dickerson B. R.
Published: March 2010

We examined the pupping phenology and genetic variation between the currently defined stocks of harbor seals, Phoca vitulina richardsi (Gray, 1864), in Washington’s coastal and inland waters and looked in detail at genetic variation within the inland waters of Washington. We analyzed mtDNA variation in 552 harbor seals from nine areas in Washington State and the Canada–US transboundary waters. A total of 73 haplotypes were detected; 37 individuals had unique haplotypes. Pupping phenology and levels of genetic variation between the outer coastal stock (WA Coastal Estuaries, WA North Coast) and the inland waters stock (British Columbia, Boundary Bay, San Juan Islands, Smith/Minor Islands, Dungeness Spit, Hood Canal, Gertrude Island) corroborated the appropriateness of the present stock boundary. However, within the inland waters stock, Hood Canal and Gertrude Island were significantly different from the coastal stock, from the rest of the inland waters stock, and from each other. This indicates a total of four genetically distinct groups in Washington State, suggesting that managing the inland waters as a single stock may be erroneous.