bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

ABSTRACT

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

ABSTRACT

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

ABSTRACTPrevious 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

ABSTRACT

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

ABSTRACT

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

ABSTRACTThe 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

Abstract
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.
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.
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.
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.
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.
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.