bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluating the Performance of Oligonucleotide Microarrays for Bacterial Strains with Increasing Genetic Divergence from the Reference Strain
Authors: Oh Seungdae , Yoder-Himes Deborah R. , Tiedje James , Park Joonhong , Konstantinidis Konstantinos T.
Published: March 2010

DNA oligonucleotide microarrays (oligoarrays) are being developed continuously; however, several issues regarding the applicability of these arrays for whole-genome DNA-DNA strain comparisons (genomotyping) have not been investigated. For example, the extent of false negatives (i.e., no hybridization signal is observed when the amino acid sequence is conserved but the nucleotide sequence has diverged to a level that does not allow hybridization) remains speculative. To provide quantitative answers to such questions, we performed competitive DNA-DNA oligoarray (60-mer) hybridizations with several fully sequenced (tester) strains and a reference strain (whose genome was used to design the oligoarray probes) of the genus
Burkholderia
and compared the experimental results obtained to the results predicted based on bioinformatic modeling of the probe-target pair using the available sequences. Our comparisons revealed that the fraction of the total probes that provided experimental results consistent with the predicted results decreased substantially with increasing divergence of the tester strain from the reference strain. The fractions were 90.8%, 84.3%, and 77.4% for tester strains showing 96% 89%, and 80% genome-aggregate average nucleotide identity (ANI) to the reference strain, respectively. New approaches to determine gene presence or absence based on the hybridization signal, which outperformed previous approaches (e.g., 92.9% accuracy versus 86.0% accuracy) and to normalize across different array experiments are also described. Collectively, our results suggest that the performance of oligoarrays is acceptable for tester strains showing >90% ANI to the reference strain and provide useful guidelines for using oligoarray applications in environmental gene detection and gene expression studies with strains other than the reference strain.
Prevalence and Seasonality of Tick-Borne Pathogens in Questing
Ixodes ricinus
Ticks from Luxembourg
Authors: Reye Anna L. , Hübschen Judith M. , Sausy Aurélie , Muller Claude P.
Published: March 2010

In Europe, ixodid ticks are important arthropod vectors of human and animal pathogens, but comprehensive studies of the prevalence of all relevant pathogens in Central Europe are scarce. As a result of ecological changes, the incidences of tick-borne infections are expected to increase. In this study, 1,394 nymphal and adult
Ixodes ricinus
ticks sampled monthly during the active season from 33 ecologically distinct collection sites throughout Luxembourg were screened for all human tick-borne pathogens relevant in Central Europe. Species were identified by sequence analysis of detection PCR amplicons. Mean infection rates of ticks were 11.3% for
Borrelia burgdorferi
sensu lato, 5.1% for
Rickettsia
sp., 2.7% for
Babesia
sp., and 1.9% for
Anaplasma phagocytophilum
. No tick was found to be infected with
Coxiella
sp.,
Francisella tularensis
subsp., or
Tick-borne encephalitis virus
(TBEV). A total of 3.2% of ticks were infected with more than one pathogen species, including mixed
Borrelia
infections (1.5%). Seasonal variations of tick infection rates were observed for
Borrelia
,
Babesia
, and
Anaplasma
, possibly reflecting a behavioral adaptation strategy of questing ticks. A positive correlation between the grade of urbanization and
Borrelia
infection rate of ticks was observed, suggesting an established urban zoonotic cycle. We also found
Hepatozoon canis
(0.1%) and
Bartonella henselae
(0.3%), which so far have not been found in questing
Ixodes ricinus
ticks in Central Europe.
Biosynthesis of Cyanobacterial Phycobiliproteins in
Escherichia coli
: Chromophorylation Efficiency and Specificity of All Bilin Lyases from
Synechococcus
sp. Strain PCC 7002
Authors: Biswas Avijit , Vasquez Yasmin M. , Dragomani Tierna M. , Kronfel Monica L. , Williams Shervonda R. , Alvey Richard M. , Bryant Donald A. , Schluchter Wendy M.
Published: March 2010

Phycobiliproteins are water-soluble, light-harvesting proteins that are highly fluorescent due to linear tetrapyrrole chromophores, which makes them valuable as probes. Enzymes called bilin lyases usually attach these bilin chromophores to specific cysteine residues within the alpha and beta subunits via thioether linkages. A multiplasmid coexpression system was used to recreate the biosynthetic pathway for phycobiliproteins from the cyanobacterium
Synechococcus
sp. strain PCC 7002 in
Escherichia coli
. This system efficiently produced chromophorylated allophycocyanin (ApcA/ApcB) and α-phycocyanin with holoprotein yields ranging from 3 to 12 mg liter
−1
of culture. This heterologous expression system was used to demonstrate that the CpcS-I and CpcU proteins are both required to attach phycocyanobilin (PCB) to allophycocyanin subunits ApcD (α
AP-B
) and ApcF (β
18
). The N-terminal, allophycocyanin-like domain of ApcE (L
CM
99
) was produced in soluble form and was shown to have intrinsic bilin lyase activity. Lastly, this
in vivo
system was used to evaluate the efficiency of the bilin lyases for production of β-phycocyanin.
Two Spx Proteins Modulate Stress Tolerance, Survival, and Virulence inStreptococcus mutans
Authors: Kajfasz Jessica K. , Rivera-Ramos Isamar , Abranches Jacqueline , Martinez Alaina R. , Rosalen Pedro L. , Derr Adam M. , Quivey Robert G. , Lemos José A.
Published: March 2010

Previous work suggested that the underlying mechanisms by which theStreptococcus mutansClpXP protease affects virulence traits are associated with accumulation of two orthologues of the Spx regulator, named SpxA and SpxB. Here, a thorough characterization of strains lacking thespxgenes (ΔspxA, ΔspxB, and ΔspxAΔspxB) revealed that Spx, indeed, participates in the regulation of processes associated withS. mutanspathogenesis. The ΔspxAstrain displayed impaired ability to grow under acidic and oxidative stress conditions and had diminished long-term viability at low pH. Although the ΔspxBstrain did not show any inherent stress-sensitive phenotype, the phenotypes observed in ΔspxAwere more pronounced in the ΔspxAΔspxBdouble mutant. By using twoin vivomodels, we demonstrate for the first time that Spx is required for virulence in a Gram-positive pathogen. Microarrays confirmed the global regulatory role of SpxA and SpxB. In particular, SpxA was shown to positively regulate genes associated with oxidative stress, a finding supported by enzymatic assays. SpxB had a secondary role in regulation of oxidative stress genes but appeared to play a larger role in controlling processes associated with cell wall homeostasis. Given the high degree of conservation between Spx proteins of low-GC Gram-positive bacteria, these results are likely to have broad implications.
Copper Stress Affects Iron Homeostasis by Destabilizing Iron-Sulfur Cluster Formation in
Bacillus subtilis
Authors: Chillappagari Shashi , Seubert Andreas , Trip Hein , Kuipers Oscar P. , Marahiel Mohamed A. , Miethke Marcus
Published: March 2010

Copper and iron are essential elements for cellular growth. Although bacteria have to overcome limitations of these metals by affine and selective uptake, excessive amounts of both metals are toxic for the cells. Here we investigated the influences of copper stress on iron homeostasis in
Bacillus subtilis
, and we present evidence that copper excess leads to imbalances of intracellular iron metabolism by disturbing assembly of iron-sulfur cofactors. Connections between copper and iron homeostasis were initially observed in microarray studies showing upregulation of Fur-dependent genes under conditions of copper excess. This effect was found to be relieved in a
csoR
mutant showing constitutive copper efflux. In contrast, stronger Fur-dependent gene induction was found in a copper efflux-deficient
copA
mutant. A significant induction of the PerR regulon was not observed under copper stress, indicating that oxidative stress did not play a major role under these conditions. Intracellular iron and copper quantification revealed that the total iron content was stable during different states of copper excess or efflux and hence that global iron limitation did not account for copper-dependent Fur derepression. Strikingly, the microarray data for copper stress revealed a broad effect on the expression of genes coding for iron-sulfur cluster biogenesis (
suf
genes) and associated pathways such as cysteine biosynthesis and genes coding for iron-sulfur cluster proteins. Since these effects suggested an interaction of copper and iron-sulfur cluster maturation, a mutant with a conditional mutation of
sufU
, encoding the essential iron-sulfur scaffold protein in
B. subtilis
, was assayed for copper sensitivity, and its growth was found to be highly susceptible to copper stress. Further, different intracellular levels of SufU were found to influence the strength of Fur-dependent gene expression. By investigating the influence of copper on cluster-loaded SufU
in vitro
, Cu(I) was found to destabilize the scaffolded cluster at submicromolar concentrations. Thus, by interfering with iron-sulfur cluster formation, copper stress leads to enhanced expression of cluster scaffold and target proteins as well as iron and sulfur acquisition pathways, suggesting a possible feedback strategy to reestablish cluster biogenesis.
CwpFM (EntFM) Is a
Bacillus cereus
Potential Cell Wall Peptidase Implicated in Adhesion, Biofilm Formation, and Virulence
Authors: Tran Seav-Ly , Guillemet Elisabeth , Gohar Michel , Lereclus Didier , Ramarao Nalini
Published: March 2010

Bacillus cereus
EntFM displays an NlpC/P60 domain, characteristic of cell wall peptidases. The protein is involved in bacterial shape, motility, adhesion to epithelial cells, biofilm formation, vacuolization of macrophages, and virulence. These data provide new information on this, so far, poorly studied toxin and suggest that this protein is a cell wall peptidase, which we propose to rename CwpFM.
Cyclic-di-GMP-Mediated Repression of Swarming Motility byPseudomonas aeruginosa: thepilY1Gene and Its Impact on Surface-Associated Behaviors
Authors: Kuchma S. L. , Ballok A. E. , Merritt J. H. , Hammond J. H. , Lu W. , Rabinowitz J. D. , O'Toole George A.
Published: March 2010

The intracellular signaling molecule cyclic-di-GMP (c-di-GMP) has been shown to influence surface-associated behaviors ofPseudomonas aeruginosa, including biofilm formation and swarming motility. Previously, we reported a role for thebifAgene in the inverse regulation of biofilm formation and swarming motility. ThebifAgene encodes a c-di-GMP-degrading phosphodiesterase (PDE), and the ΔbifAmutant exhibits increased cellular pools of c-di-GMP, forms hyperbiofilms, and is unable to swarm. In this study, we isolated suppressors of the ΔbifAswarming defect. Strains with mutations in thepilY1gene, but not in the pilin subunitpilAgene, show robust suppression of the swarming defect of the ΔbifAmutant, as well as its hyperbiofilm phenotype. Despite the ability of thepilY1mutation to suppress all the c-di-GMP-related phenotypes, the global pools of c-di-GMP are not detectably altered in the ΔbifAΔpilY1mutant relative to the ΔbifAsingle mutant. We also show that enhanced expression of thepilY1gene inhibits swarming motility, and we identify residues in the putative VWA domain of PilY1 that are important for this phenotype. Furthermore, swarming repression by PilY1 specifically requires the diguanylate cyclase (DGC) SadC, and epistasis analysis indicates that PilY1 functions upstream of SadC. Our data indicate that PilY1 participates in multiple surface behaviors ofP. aeruginosa, and we propose that PilY1 may act via regulation of SadC DGC activity but independently of altering global c-di-GMP levels.
Cardiac CT: non-coronary applications
Authors: Gopalan Deepa , Raj Vimal , Hoey Edward T D
Published: March 2010

Cardiac CT involves acquisition of high-quality ECG-gated dynamic images of the heart. ECG gating allows exquisite delineation of the coronary arteries, which are subjected to respiratory and cardiac motion. Cardiac CT has an established role in the assessment of coronary artery disease in selected patient groups and permits detailed assessment of cardiac and great vessel anatomy. The technique can also be used for a number of non-coronary applications including assessment of the pericardium, cardiac tumours and pulmonary veins. In this article, these applications are reviewed and the salient imaging findings across a range of structural cardiac disease illustrated.
Codependence of repetitive sequence classes in genomes: phylogenetic analysis of 5S rDNA families in Hordeum (Triticeae: Poaceae)
Authors: Baum Bernard R. , Edwards Tara , Johnson Douglas A.
Published: March 2010

To complete our study of the genus Hordeum and to elaborate a phylogeny of species based upon 5S rDNA sequences, we have cloned and sequenced PCR amplicons from seven American polyploid species to generate 164 new 5S rRNA gene sequences. These sequences were analysed along with the more than 2000 5S rDNA sequences previously generated from the majority of species in Hordeum to provide a comprehensive picture of the distribution (presence or absence) of 5S rDNA unit classes (orthologous groups) in this genus as well as insights into the phylogeny of Hordeum. Testing of substitution models for each unit class based upon the consensus sequences of all the taxa as well as for each unit class within the genus found that the general best fit was TPM3uf+G, from which a maximum-likelihood tree was calculated. A novel application of cophylogenetic analysis, where relationships among unit classes were treated as host–parasite interactions, depicted some significant pair links under tests of randomness indicative of nonrandom codivergence among several unit classes within the same taxon. The previous classification of four genomic groups is reflected in combinations of unit classes, and it is proposed that current taxa developed from ancient diploidized paleopolyploids and that some were subjected to gene loss, i.e., unit class loss. Finally, separate phylogenetic analyses performed for the tetraploid and hexaploid species were used to derive a working model describing the phylogeny of the polyploid taxa from their putative diploid ancestry.
Genetic control of phenotypic plasticity in Asian cultivated and wild rice in response to nutrient and density changes
Authors: Shimizu Hiroyuki , Maruoka Masamichi , Ichikawa Naofumi , Baruah Akhil Ranjan , Uwatoko Naohiro , Sano Yoshio , Onishi Kazumitsu
Published: March 2010

Phenotypic plasticity is an adaptive mechanism adopted by plants in response to environmental heterogeneity. Cultivated and wild species adapt in contrasting environments; however, it is not well understood how genetic changes responsible for phenotypic plasticity were involved in crop evolution. We investigated the genetic control of phenotypic plasticity in Asian cultivated ( Oryza sativa ) and wild rice ( O. rufipogon ) under 5 environmental conditions (2 nutrient and 3 density levels). Quantitative trait locus (QTL) analysis was conducted for traits affecting plant architecture and biomass production. By analysing the phenotypic means, QTLs of large effects were detected as a cluster on chromosome 7 under all the environmental conditions investigated; this might have contributed to transitions of plant architecture during domestication, as reported previously. Multiple QTLs of plasticity were also found within this QTL cluster, demonstrating that allele-specific environmental sensitivity might control plasticity. Furthermore, QTLs controlling plasticity without affecting phenotypic means were also identified. The mode of action and direction of allele effects of plasticity QTLs varied depending on the traits and environmental signals. These findings confirmed that cultivated and wild rice show distinctive genetic differentiation for phenotypic plasticity, which might have contributed to adaptation under contrasting environmental heterogeneity during the domestication of rice.
Performance-based seismic retrofit of a bridge bent: Design and experimental validation
Authors: Roy Nathalie , Paultre Patrick , Proulx Jean
Published: March 2010

Changes in the 2005 edition of the National building code of Canada resulted in an increase in earthquake hazard for some regions in Canada. This project studied the impact of this increase on a selected highway bridge. A seismic retrofit scheme, using carbon-fiber-reinforced polymers (CFRPs), was developed and applied to the selected highway bridge bent. The retrofitting technique is based on specific performance criteria under which the retrofitted structure must meet prescribed ductility levels corresponding to selected seismic events, and its design includes a new confinement model for reinforced-concrete columns wrapped with CFRP. Using this performance-based approach, the amount of required composite materials to achieve the specified criteria was found to be much more economical when compared with the ductility requirements in the 2000 edition of the Canadian highway bridge design code. The performance of the retrofitting technique was evaluated by pseudo-dynamic tests carried out on a 1:3 scale model of one of the bridge bents. Using the substructuring approach, the remainder of the structure was modeled, and the bridge bent was subjected to increasing levels of seismic loading, corresponding to various limit states of the bridge. The measured response of the test specimen compared well with the predictions of a three-dimensional (3D) nonlinear finite-element model calibrated with dynamic properties obtained from on-site ambient vibration tests. During the highest intensity test corresponding to a return period of 2500 years for a region of high seismicity, the CFRP retrofit showed no sign of distress, and the strain values measured on the fibers were very low, indicating that the performance-based design procedure is conservative.
Sound absorption characteristics of porous asphalt concrete pavements
Authors: Mun Sungho
Published: March 2010

This study investigates the sound absorption characteristics of porous asphalt concrete (PAC) pavements using an impedance tube to assess noise reduction performance. It is clearly shown that an improved attenuation of sound wave energy is achieved by adjusting the air void content, aggregate gradation, and PAC pavement thickness, based on measurements of sound absorption coefficients. In addition, traffic noise measurements taken from PAC pavements in the field are compared to those taken from dense-graded asphalt concrete (DGAC), which is widely used in pavement materials.
Fuzzy set theory based methodology for the analysis of measurement uncertainties in river discharge and stage
Authors: Shrestha Rajesh R. , Simonovic Slobodan P.
Published: March 2010

The discharge and stage measurements in a river system are characterized by a number of sources of uncertainty, which affects the accuracy of a rating curve established from measurements. This paper presents a fuzzy set theory based methodology for consideration of different sources of uncertainty in the stage and discharge measurements and their aggregation into a combined uncertainty. The uncertainty in individual measurements of stage and discharge is represented using triangular fuzzy numbers, and their spread is determined according to the International Organization for Standardization (ISO) standard 748 guidelines. The extension principle based fuzzy arithmetic is used for the aggregation of various uncertainties into overall stage–discharge measurement uncertainty. In addition, a fuzzified form of ISO 748 formulation is used for the calculation of combined uncertainty and comparison with the fuzzy aggregation method. The methodology developed in this paper is illustrated with a case study of the Thompson River near Spences Bridge in British Columbia, Canada. The results of the case study show that the selection of number of velocity measurement points on a vertical is the largest source of uncertainty in discharge measurement. An increase in the number of velocity measurement points provides the most effective reduction in the overall uncertainty. The next most important source of uncertainty for the case study location is the number of verticals used for velocity measurements. The study also shows that fuzzy set theory provides a suitable methodology for the uncertainty analysis of stage–discharge measurements.
Predicting areas of high diesel particulate matter emissions in Phoenix, Arizona, using spatial analysis techniquesA paper submitted to the Journal of Environmental Engineering and Science.
Authors: Penfold Bryan M. , Hafner Hilary R. , Brown Steven G.
Published: March 2010

Growing evidence suggests that inhalation exposure to diesel exhaust, including diesel particulate matter (DPM), causes acute and chronic health effects. As a result, interest in monitoring diesel exhaust has increased. Maps of emissions sources, emissions activity data, and meteorology were combined within a geographic information system (GIS) suitability model to produce a composite map identifying areas where DPM emissions are likely to be high. The results of the GIS model were compared with (i) the locations of existing monitoring sites in Phoenix, Arizona, and (ii) the spatial distribution of population. The results indicate that two existing sites are located in areas where DPM emissions are predicted to be high; however, incorporating meteorology as a factor showed that one site is located upwind of a predicted high DPM area. Consideration of population density showed high density in two areas that appear to be moderately influenced by DPM.
Comparison of mechanistic laboratory characterization and 10-year rutting performance of SPS-9A test site in Saskatchewan
Authors: Berthelot Curtis , Podborochynski Diana , Anthony Ania , Marjerison Brent
Published: March 2010

This paper provides a performance comparison of mechanistic laboratory and field rutting performance of four asphalt concrete mixes constructed in 1996 at a Strategic Highway Research Program SPS-9A test site located in Saskatchewan. The asphalt mixes included two Saskatchewan Type 70 Marshall mixes and two coarse graded Superpave™ mixes and employed 150–200A and 200–300A penetration grade asphalt cement binders. The triaxial frequency sweep characterization determined that the Superpave™ mix yielded improved mechanistic structural constitutive properties when compared to the Saskatchewan Type 70 mix. In addition, improved mechanistic structural properties were observed with the mixes employing 150–200A (PG 58-28) asphalt binder relative to the 200–300A (PG 52-34) asphalt binder, particularly the Saskatchewan Type 70 mix. The 10-year rutting performance of the Radisson SPS-9A test site was evaluated and the field rutting results concurred with the triaxial frequency sweep test results. The triaxial frequency sweep characterization employed in this study appears to adequately rank asphalt mixes with respect to field rutting performance.
Transfer hydrogenations of benzaldehyde using glycerol as solvent and hydrogen source
Authors: Tavor Dorith , Sheviev Oxana , Dlugy Christina , Wolfson Adi
Published: March 2010

Benzaldehyde was successfully reduced by catalytic transfer hydrogenation in glycerol using several ruthenium based complexes and bases. Glycerol was employed as a green solvent and hydrogen source, and it allowed for easy product separation and catalyst recycling and enabled the use of a microwave-assisted reaction.
Microwave-assisted, palladium-catalyzed carbonylative cyclization — Rapid synthesis of 2-quinolones from unprotected 2-iodoanilines and terminal alkynes
Authors: Chen Jia-Rong , Liao Jie , Xiao Wen-Jing
Published: March 2010

Palladium-catalyzed cyclocarbonylations of 2-iodoanilines with various terminal alkynes have been carried out by the use of commercially available molybdenum hexacarbonyl as a convenient and solid carbon monoxide source. The reactions were conducted at 160 °C for 30 min under microwave irradiation and in the presence of Et3N in THF, affording the corresponding 2-quinolone derivatives in good regioselectivities and yields.
AGOA hydration clusters produce the solvation effect on the aziridine···hydrofluoric acid complex — A modern proposal
Authors: Oliveira Boaz G. , Araújo Regiane C.M.U. , Carvalho Antônio B. , Ramos Mozart N.
Published: March 2010

The AGOA methodology was used to describe the hydration clusters of the C2H5N···HF heterocyclic hydrogen-bonded complex. Using the TIP4P water-geometry model, the hydration clusters were generated by analyzing the finite gradients of the molecular electrostatic potential (MEP) of the solute (C2H5N···HF). The results obtained revealed high hydration energies (ΔEHC-CORR) in the positive MEP field, indicating that the water molecules prefer to attack the methyl groups of the aziridine ring upon the formation of the C2H5N···HF hydrogen-bonded complex. Although they are in accordance with the experimental behavior of the aziridine acid-catalyzed open-ring reaction, the theoretical results obtained here provide a new perspective on studies of the solvation effect because the AGOA protocol requires little computational effort to create the hydration-cluster structures.
Determining the maximum environmental release limit of the toxic dye, CHPD
Authors: Balakrishnan Vimal K. , Palabrica Virginia
Published: March 2010

The Canadian Environmental Protection Act, 1999 (CEPA, 1999) requires the Canadian government to categorize all substances on the Domestic Substances List (DSL). Under the Chemicals Management Plan, the Government of Canada addresses chemicals that had not previously undergone rigorous scientific assessment. One such compound, [[4-[[2-(4-cyclohexylphenoxy)ethyl]ethylamino]-2-methylphenyl]methylene]-, propanedinitrile, commonly known as CHPD (cyclohexylphenoxydinitrile), recently underwent a screening assessment and was declared to be “toxic” to the environment. As a result, the Government of Canada ordered the “virtual elimination” of CHPD from the environment. Thus, CHPD may not be present above the lowest concentration that can be accurately measured using sensitive, but routine, analytical methods. We present a solid-phase extraction (SPE) method to determine CHPD in water and wastewater effluent to establish the maximum environmental release limit for this toxic compound. Optimal extraction was attained using an ENVI-18 cartridge. Extracts were analyzed by HPLC–PDA and HPLC–MS/MS techniques; in both matrices, the PDA method had greater sensitivity, less susceptibility to matrix effects, lower limit of quantitation (LOQ) values, and could be successfully validated at multiple spike levels. The lowest concentration of CHPD that could accurately be measured was found to be 108 ng/L in extracts of pure water, using the HPLC–PDA system. Therefore, this value (108 ng/L) will inform regulations on the maximum environmental release limit for CHPD.
Effect of long-term treatment with urocortin on the activity of somatic angiotensin-converting enzyme in spontaneously hypertensive rats
Authors: Yang Cui , Liu Xiuxia , Li Shengnan
Published: March 2010

Our previous acute study on urocortin (Ucn) demonstrated that Ucn altered serum and tissue angiotensin-converting enzyme (ACE) activity in rats. Therefore, the present investigation was designed to explore the effect of long-term treatment with Ucn on somatic ACE (sACE) and other components of the renin–angiotensin system (RAS). After 8 weeks of intravenous administration of Ucn in spontaneously hypertensive rats (SHR), serum and tissue sACE, angiotensin II (Ang II), nitric oxide (NO), Ang-(1–7), and tissue chymase activities were evaluated. RT-PCR analysis was performed to determine the quantity of tissue sACE mRNA. Serum sACE activity was reduced by Ucn, although tissue sACE activity and tissue sACE mRNA were elevated. Chymase activity was observed to be enhanced by Ucn, whereas the ACE inhibitor enalapril failed to influence chymase. Serum and tissue Ang II activity was reduced, but NO and Ang-(1–7) production was increased in a concentration-dependent manner after Ucn treatment. Meanwhile, a significant decrease of the systolic blood pressure (SBP) was observed after the long-term Ucn administration, and there was a significant positive correlation (r2 = 0.6993) between serum ACE activity and SBP. Pretreatment with the corticotropin-releasing factor (CRF) blocker astressin and the extracellular signal-regulated kinase 1/2 (ERK1/2) pathway blocker PD98059 abolished these effects of Ucn. Our findings further support the hypothesis that the changes of sACE activity and the production of other RAS components may play roles in the vasodilatory property of Ucn via the activation of the ERK1/2 pathway.
Organic anion transporter 3 (OAT3) and renal transport of the metal chelator 2,3-dimercapto-1-propanesulfonic acid (DMPS)
Authors: Rödiger Matthias , Zhang Xiaohong , Ugele Bernhard , Gersdorff Nikolaus , Wright Stephen H. , Burckhardt Gerhard , Bahn Andrew
Published: March 2010

Recent investigations involving intact rabbit renal proximal tubules indicated that organic anion transporter 3 (OAT3) may be involved in the transport of 2,3-dimercapto-1-propanesulfonic acid (DMPS). Therefore, we evaluated the interaction of OAT3 with DMPS to determine the effect of OAT3 on basolateral DMPS uptake. We used stably transfected HEK293 cells expressing human and rabbit orthologs of the exchanger OAT1 and OAT3. Using 6-carboxyfluorescein (6-CF) as a substrate, the IC50determinations for reduced DMPS (DMPSH) revealed a stronger interaction with OAT1 than with OAT3 (rbOAT1, 123.3 ± 13.7; hOAT1, 85.1 ± 8.8; rbOAT3, 171.7 ± 22.3; and hOAT3, 172.2 ± 36.4 µmol/L). However, inhibition of 6-CF uptake by the oxidized form of DMPS (DMPSS), the main form of DMPS in the blood, showed a greater affinity for OAT3 (rbOAT1, 237.4 ± 23; hOAT1, 104.6 ± 13.1; rbOAT3, 52.4 ± 7.6; and hOAT3, 31.6 ± 6.6 µmol/L). To determine whether DMPSH and DMPSS are substrates for OAT3, we performed efflux studies with [14C]glutarate and inwardly directed gradients of glutarate. The inhibitors trans-stimulated the efflux of [14C]glutarate, suggesting that OAT3 may be able to transport both forms of DMPS. On the basis of the substantial interaction of OAT3 with DMPSS, we conclude that OAT3 represents the dominant basolateral player in renal detoxification processes resulting from use of DMPS.
Interactions between parasites and pollutants in yellow perch (Perca flavescens) in the St. Lawrence River, Canada: implications for resistance and tolerance to parasites
Authors: Marcogliese David J. , Dautremepuits Claire , Gendron Andrée D. , Fournier Michel
Published: March 2010

Parasites were examined in yellow perch, Perca flavescens (Mitchill, 1814), from four localities ranging in degree of pollution in the St. Lawrence River, Quebec, Canada, to examine the effects of the most prevalent parasite species on expression of biomarkers of oxidative stress. Various biomarkers appeared to be affected by the infection levels of Apophallus brevis Ransom, 1920 and genus Diplostomum von Nordmann, 1832. For certain biomarkers, interactions between infection level and pollution type were detected for A. brevis, Diplostomum spp., and genus Ichthyocotylurus Odening, 1969. Activity of glutathione reductase in gill tissue decreased with increasing numbers of A. brevis, but only at the two most polluted localities. Catalase activity in kidney increased with numbers of Diplostomum spp. at the polluted localities, but not at the two least contaminated sites. Results suggest that parasites may affect expression of biomarkers of pollution and that pathogenicity of parasites may be enhanced under polluted conditions. Exposure to contaminants appears to reduce tolerance, but not resistance, to parasites in yellow perch in this system. This type of immunosuppression may be widespread in polluted ecosystems.
Kinship does not affect vigilance in Columbian ground squirrels (Urocitellus columbianus)
Authors: Fairbanks B. M. , Dobson F. S.
Published: March 2010

Vigilance, a vital behaviour in prey species, is affected by many factors, including social group size and possibly the presence of relatives. Columbian ground squirrels ( Urocitellus columbianus (Ord, 1815)) show a group-size effect of reduced individual vigilance in larger groups owing to increased predator detection. Such groups are composed of both kin and nonkin individuals. We observed vigilance (raising head above shoulders while foraging) of yearling males and yearling and older females, and examined kin relationships that are learned in the natal nest (viz., uterine kin). We then tested for possible effects of kinship on vigilance and thus on the group-size effect. Because of the kin-biased behaviours and nepotistic alarm calls shown by ground squirrels in previous studies, we expected either a kin-cooperative influence on vigilance or a nepotistic asymmetrical effect on vigilance,. We found that the presence of kin (whether above ground or not) had little or no effect on vigilance. This lack of kin effect reveals that Columbian ground squirrels do not rely any more on close relatives than on unrelated group members for detecting predators. Thus, the presence of kin does not contribute to the group-size effect on vigilance.
Interannual assessment of territory quality for male sea otters (Enhydra lutris) in Simpson Bay, Prince William Sound, Alaska
Authors: Finerty Shannon E. , Pearson Heidi C. , Davis Randall W.
Published: March 2010

Territory quality and site fidelity were assessed for male sea otters ( Enhydra lutris (L., 1758)) in Simpson Bay, Prince William Sound, Alaska, during the summer months (May–August) from 2003 to 2006. Territory quality was coded with a score of 0–2 for four attributes: territory size, shoreline enclosure, territory accessibility, and number of females observed feeding in each territory. Total quality scores ranged from 0.14 to 1.96 (0.9 ± 0.61, mean ± SD), with the highest quality territories having large areas, moderate to little shoreline enclosure, high accessibility, and many foraging females. A total of 13.1 km2 (62.5%) of Simpson Bay was occupied at least once by a territorial male during the 4-year study, and 7.9 km2 (37.5%) was never occupied by a territorial male. There were 7 ± 2.4 (mean ± SD) territorial males in Simpson Bay each year. Five males maintained territories for two consecutive years, with their respective territories having a 16%–34% overlap between years, indicating that repeat territory holders returned to the same area. The number of territorial sea otters, the size of territories, and whether or not a sea otter was a repeat territory holder did not significantly influence the size or quality of male territories.
Habitat use by western black widow spiders (Latrodectus hesperus) in coastal British Columbia: evidence of facultative group living
Authors: Salomon Maxence , Vibert Samantha , Bennett Robert G.
Published: March 2010

Animal social systems come in a wide range of forms characterized by different types of group-living relationships. Species that express facultative group-living behaviours, where individuals only associate under certain conditions or at certain times, are especially interesting for studying social evolution. We investigated the social structure of the western black widow spider ( Latrodectus hesperus Chamberlin and Ivie, 1935) over 5 years in a coastal British Columbia habitat, and present the first comprehensive evidence of facultative group living in the genus Latrodectus Walckenaer, 1805. Latrodectus hesperus have a flexible social structure that varies seasonally, wherein individuals (mostly females) either form groups or live solitarily. In the fall and early winter, females spontaneously form groups of 2–8 individuals, but live alone during the oviposition season in the spring and summer. When living in groups spiders share large webs and are tolerant of each other, although they appear to forage individually. We also report on the relationships between different ecological factors and the social structure of L. hesperus, including the interaction of these spiders with two co-occurring species of introduced spiders ( Tegenaria agrestis (Walckenaer, 1802) and Tegenaria duellica Simon, 1875). Our findings suggest that L. hesperus is a good model system with which to explore the mechanisms involved in the evolution of sociality.
Seasonal variation in prey abundance influences habitat use by greater horseshoe bats (Rhinolophus ferrumequinum) in a temperate deciduous forest
Authors: Wang J. , Gao W. , Wang L. , Metzner W. , Ma J. , Feng J.
Published: March 2010

The hypothesis that patterns of habitat selection of greater horseshoe bats ( Rhinolophus ferrumequinum (Schreber, 1774)) vary across seasons in a temperate deciduous forest was investigated. Variables associated with potentially important ecological factors for greater horseshoe bats (physical structure of shrub stratum, crown canopy, insect availability, lunar phase, and weather) were collected for different seasons, and 75 sampling sites were established in the Luotong Mountain Nature Reserve in northeast China. Insect abundance was highest in late summer and lowest in late autumn. Poisson generalized linear models showed that the activity of greater horseshoe bats was positively related to the height and density of shrub stratum in late summer, whereas the activity of greater horseshoe bats was associated with insect abundance in early and late autumn. During periods of intermediate prey abundance (early summer), the height and density of shrub stratum, as well as insect abundance, influenced the activity of greater horseshoe bats. Shrub stratum may provide shelter against predation for foraging greater horseshoe bats. These results support our prediction that there was a trade-off between importance of food and cover among seasons for foraging bats. These findings are useful for the conservation and management of greater horseshoe bats.
Stability of swimming performance and activity hierarchies among wild largemouth bass at multiple temporal scales: evidence for context-dependent shuffling between seasons
Authors: Hanson K. C. , Hasler C. T. , Donaldson M. R. , Cooke S. J.
Published: March 2010

Laboratory-based studies of locomotory performance in many taxa have noted that individuals form stable hierarchies of organismal performance. Though laboratory studies of teleost fishes have consistently demonstrated individual repeatability of swimming performance, this phenomenon has rarely been studied in the field and never across multiple years. Using a whole-lake acoustic telemetry array with submetre accuracy, we assessed the individual repeatability of two metrics of swimming performance (daily distance traveled and mean daily swimming speed) within four seasons during a year (fall, winter, spring, and summer), among these seasons, and between winters of 2 years. Largemouth bass ( Micropterus salmoides (Lacepède, 1802)) formed stable performance hierarchies within seasons except spring and no sex-specific differences in rankings were noted. Individual swimming performance was not repeatable among seasons during 1 year or across multiple winters. Seasonal changes in environmental and intrinsic biological conditions appear to result in a reshuffling of performance hierarchies, perhaps reflecting individual differences in organismal physiology.
Targeted Marketing and Public Health
Authors: Grier Sonya A. , Kumanyika Shiriki
Published: March 2010

Targeted marketing techniques, which identify consumers who share common needs or characteristics and position products or services to appeal to and reach these consumers, are now the core of all marketing and facilitate its effectiveness. However, targeted marketing, particularly of products with proven or potential adverse effects (e.g., tobacco, alcohol, entertainment violence, or unhealthful foods) to consumer segments defined as vulnerable raises complex concerns for public health. It is critical that practitioners, academics, and policy makers in marketing, public health, and other fields recognize and understand targeted marketing as a specific contextual influence on the health of children and adolescents and, for different reasons, ethnic minority populations and other populations who may benefit from public health protections. For beneficial products, such understanding can foster more socially productive targeting. For potentially harmful products, understanding the nature and scope of targeted marketing influences will support identification and implementation of corrective policies.
Family History in Public Health Practice: A Genomic Tool for Disease Prevention and Health Promotion
Authors: Valdez Rodolfo , Yoon Paula W. , Qureshi Nadeem , Green Ridgely Fisk , Khoury Muin J.
Published: March 2010

Family history is a risk factor for many chronic diseases, including cancer, cardiovascular disease, and diabetes. Professional guidelines usually include family history to assess health risk, initiate interventions, and motivate behavioral changes. The advantages of family history over other genomic tools include a lower cost, greater acceptability, and a reflection of shared genetic and environmental factors. However, the utility of family history in public health has been poorly explored. To establish family history as a public health tool, it needs to be evaluated within the ACCE framework (analytical validity; clinical validity; clinical utility; and ethical, legal, and social issues). Currently, private and public organizations are developing tools to collect standardized family histories of many diseases. Their goal is to create family history tools that have decision support capabilities and are compatible with electronic health records. These advances will help realize the potential of family history as a public health tool.
Evaluability Assessment to Improve Public Health Policies, Programs, and Practices
Authors: Leviton Laura C. , Khan Laura Kettel , Rog Debra , Dawkins Nicola , Cotton David
Published: March 2010

Evaluability assessment, also commonly known as exploratory evaluation, has assisted the field of public health to improve programs and to develop a pragmatic, practice-based research agenda. Evaluability assessment was originally developed as a low-cost pre-evaluation activity to prepare better for conventional evaluations of programs, practices, and some policies. For public health programs, however, it serves several other important purposes: (a) giving program staff rapid, constructive feedback about program operations; (b) assisting the core public health planning and assurance functions by helping to develop realistic objectives and providing low-cost, rapid feedback on implementation; (c) navigating federal performance measurement requirements; (d) translating research into practice by examining the feasibility, acceptability, and adaptation of evidence-based practices in new settings and populations; and (e) translating practice into research by identifying promising new approaches to achieve public health goals.
Advances in Understanding Benzene Health Effects and Susceptibility
Authors: Smith Martyn T.
Published: March 2010

Benzene is a ubiquitous chemical in our environment that causes acute leukemia and probably other hematological cancers. Evidence for an association with childhood leukemia is growing. Exposure to benzene can lead to multiple alterations that contribute to the leukemogenic process, indicating a multimodal mechanism of action. Research is needed to elucidate the different roles of multiple metabolites in benzene toxicity and the pathways that lead to their formation. Studies to date have identified a number of polymorphisms in candidate genes that confer susceptibility to benzene hematotoxicity. However, a genome-wide study is needed to truly assess the role of genetic variation in susceptibility. Benzene affects the blood-forming system at low levels of occupational exposure, and there is no evidence of a threshold. There is probably no safe level of exposure to benzene, and all exposures constitute some risk in a linear, if not supralinear, and additive fashion.
Approaches to Uncertainty in Exposure Assessment in Environmental Epidemiology
Authors: Spiegelman Donna
Published: March 2010

Uncertainty in assessment of individual exposure levels leads to bias, often, but not always, toward the null in estimates of health effects, and to underestimation of the variability of the estimates, leading to anticonservative p-values. In the absence of data on the uncertainty in individual exposure estimates, sensitivity analysis, also known as uncertainty analysis and bias analysis, is available. Hypothesized values of key parameters of the model relating the observed exposure to the true exposure are used to assess the resulting amount of bias in point and interval estimates. In general, the relative risk estimates can vary from zero to infinity as the hypothesized values of key parameters of the measurement error model vary. Thus, we recommend that exposure validation data be used to empirically adjust point and interval estimates of health effects for measurement error. The remainder of this review gives an overview of available methods for doing so. Just as we routinely adjust for confounding, we can and should routinely adjust for measurement error.
Experience with a theme-based integrated renal module for a second-year MBBS class
Authors: Shafi Riffat , Quadri K. H. M. , Ahmed Waseem , Mahmud Syed Nayer , Iqbal Mobeen
Published: March 2010

Integrated learning is the need of the hour. We at Shifa College of Medicine switched to an integrated modular curriculum last year. In the present article, we describe our experience with the renal module in year 2 of a 5-yr undergraduate medical curriculum. A multidisciplinary renal modular team developed the relevant objectives, themes, and clinical cases. The learning strategies used were large-group interactive sessions, small-group learning, problem-based learning, practicals, and self-directed learning. Assessment was both formative and summative. Student and faculty feedback questionnaires were administered at the end of the module. Forty-four percent of the students agreed that the basic science and clinical concepts were well balanced and integrated. Fifty-seven percent of the students believed that important learning issues could be identified and that participation and critical thinking were encouraged during the small-group sessions. Eighty-five percent of the facilitators agreed that they were able to motivate students for critical thinking and better learning through integrating various disciplines. In conclusion, the integrated method of curricular delivery was well received by students and faculty members, and it can be used successfully in undergraduate medical education in developing countries.
Physiology teaching and learning experience in a new modular curriculum at the National University of Rwanda
Authors: Gahutu Jean Bosco
Published: March 2010

In the present article, I report on my experience in teaching and learning physiology in the first year of a new modular curriculum at the Faculty of Medicine of the National University of Rwanda. With self-reported questionnaires, I collected learning experience perceptions from 112 students who attended the module of physiology in 2008. The results showed satisfaction with active learning methods but complaints about the limited contact hours allocated to classroom lectures and practical classes. Student-centered learning was handicapped by the limited computer and internet access for students and by the limited number of textbooks in the library. In conclusion, the new teaching and learning style was appreciated by the students, but problems related to limited human and material resources need to be solved.