bluuebunny/crossref_metadata_2025 huggingface dataset:
Nurse practitioners’ contributions to cultural competence in primary care settings
Authors: Matteliano Mary A. , Street Debra
Published: March 2012

Purpose: To document unique ways Nurse Practitioners (NPs) contribute to the delivery of culturally competent healthcare to diverse and underserved patient populations in urban primary care practices.

Data Sources: Data are from a multi‐year, multi‐site study and includes 50 intensive interviews with healthcare professionals and repeated observations at three urban primary health clinics in a Northeastern U.S. city.

Conclusions and Implications for Practice: Different healthcare professionals reported common perspectives on cultural competence dealing with distinctive patient communities, including altruistic motivations, advocacy, and addressing root causes while treating diverse patients. What made NPs distinct among healthcare workers in this study was the comprehensiveness of their cultural competence approaches, both in patient interactions and within healthcare teams. NPs established culturally sensitive partnerships with patients, encouraged self‐advocacy, addressed contextual considerations, and adjusted practices to meet the patient needs. They also developed niches in multidisciplinary teams that emphasized holistic approaches to establish trust and to cross cultural boundaries, both with other health professionals and their diverse patients.
Assembling an experimentalist regime: Transnational governance interactions in the forest sector
Authors: Overdevest Christine , Zeitlin Jonathan
Published: March 2012

Transnational governance initiatives increasingly face the problem of regime complexity in which a proliferation of regulatory schemes operate in the same policy domain, supported by varying combinations of public and private actors. The literature suggests that such regime complexity can lead to forum shopping and other self‐interested strategies, which undermine the effectiveness of transnational regulation. Based on the design principles of experimentalist governance, this paper identifies a variety of pathways and mechanisms, which promote productive interactions in regime complexes. We use the case of the EU's Forest Law Enforcement Governance and Trade (FLEGT) initiative, interacting with private certification schemes and public legal timber regulations, including those of third countries such as the US and China, to demonstrate how an increasingly comprehensive transnational regime can be assembled by linking together distinct components of a regime complex. We argue that it is the experimentalist features of this initiative and its regulatory interactions, which accommodate local diversity and foster recursive learning from decentralized implementation experience, that make it possible to build up a flexible and adaptive transnational governance regime from an assemblage of interconnected pieces, even in situations where interests diverge and no hegemon can impose its own will.
The Sixth Annual Translational Stem Cell Research Conference of the New York Stem Cell Foundation
Authors: Marshall Caroline , Hua Haiqing , Shang Linshan , Ding Bi‐Sen , Zito Giovanni , de Peppo Giuseppe Maria , Wang George Kai , Douvaras Panagiotis , Sproul Andrew A. , Paull Daniel , Fossati Valentina , Nestor Michael W. , McKeon David , Smith Kristin A. , Solomon Susan L.
Published: March 2012

ABSTRACT  The New York Stem Cell Foundation's “Sixth Annual Translational Stem Cell Research Conference” convened on October 11–12, 2011 at the Rockefeller University in New York City. Over 450 scientists, patient advocates, and stem cell research supporters from 14 countries registered for the conference. In addition to poster and platform presentations, the conference featured panels entitled “Road to the Clinic” and “The Future of Regenerative Medicine.”
A Novel Pathway of Photoinduced Decomposition of Sphingolipids
Authors: Lisovskaya Alexandra G. , Edimecheva Irina P. , Shadyro Oleg I.
Published: March 2012

A possibility of a novel photodestruction process has been shown for sphingolipids and their low‐molecular analogues, including the stage of Norrish Type‐I decomposition of excited molecules of the starting compounds followed by fragmentation of nitrogen‐centered radicals via rupture of the C–C and O–H bonds. Realization of such transformation during photolysis of ceramide, sphingomyelin and galactocerebroside results in formation of 2‐hexadecenal, which possess a wide spectrum of biological activity.
A novel β‐globin gene mutation HBB.c.22 G>C produces a hemoglobin variant (Hb Vellore) mimicking HbS in HPLC
Authors: EDISON E. S. , SATHYA M. , RAJKUMAR S. V. , NAIR S. C. , SRIVASTAVA A. , SHAJI R. V.
Published: April 2012

Hemoglobinopathies are highly prevalent in Indian population. DNA analysis to detect causative mutations is required for identifying rare hemoglobin variants or when hematological results are discordant with the clinical phenotype. In this report, we describe a novel hemoglobin variant caused by a mutation in beta‐globin gene, Codon 7 GAG→CAG (Glu→Gln) that elutes in the position of sickle haemoglobin (HbS) in cation exchange high performance liquid chromatography. This report highlights possible diagnostic pitfalls in interpreting data solely based on haemoglobin analysis and usefulness of mutation screening in definitive diagnosis of hemoglobinopathies.
Evolution of Bacillus thuringiensis Cry toxins insecticidal activity
Authors: Bravo Alejandra , Gómez Isabel , Porta Helena , García‐Gómez Blanca Ines , Rodriguez‐Almazan Claudia , Pardo Liliana , Soberón Mario
Published: March 2012

Insecticidal Cry proteins produced by Bacillus thuringiensis are use worldwide in transgenic crops for efficient pest control. Among the family of Cry toxins, the three domain Cry family is the better characterized regarding their natural evolution leading to a large number of Cry proteins with similar structure, mode of action but different insect specificity. Also, this group is the better characterized regarding the study of their mode of action and the molecular basis of insect specificity. In this review we discuss how Cry toxins have evolved insect specificity in nature and analyse several cases of improvement of Cry toxin action by genetic engineering, some of these examples are currently used in transgenic crops. We believe that the success in the improvement of insecticidal activity by genetic evolution of Cry toxins will depend on the knowledge of the rate‐limiting steps of Cry toxicity in different insect pests, the mapping of the specificity binding regions in the Cry toxins, as well as the improvement of mutagenesis strategies and selection procedures.
Does Idiosyncratic Risk Matter for Individual Securities?
Authors: Vozlyublennaia Nadia
Published: April 2012

This paper investigates the relationship between idiosyncratic risk and returns for individual securities within a generalized autoregressive conditional heteroskedascticity (GARCH)‐in‐mean framework. We demonstrate that, on average, 15% of stocks exhibit a significant relationship between returns and risk, of which 9% are positive. These proportions vary over time and with model specifications. Some characteristics influence the probability of a positive and a negative relationship, while others appear to affect only one, but not the other. This evidence implies that the factors that explain a positive connection between idiosyncratic risk and returns are different from the factors that explain a negative connection.
Bilateral cataract induced by unilateral UVR‐B exposure – evidence for an inflammatory response
Authors: Meyer Linda M. , Löfgren Stefan , Holz Frank G. , Wegener Alfred , Söderberg Per
Published: March 2012

Purpose:  To investigate whether unilateral in vivo UVR‐B exposure of one eye affects the fellow eye in a co‐cataractogenic, sympathetic reaction and to determine whether an inflammatory response could be involved in the pathogenesis.

Methods:  C57BL/6 mice were unilaterally exposed in vivo to UVR‐B for 15 min. In the group of 24 animals each received 0×/2×/3×/or 4× cataract threshold equivalent dose. Following 48‐hr UVR‐B exposure, cataract morphology was documented in dark‐field illumination photography, and light scattering was quantified, in both lenses in vitro. Serum levels of pro‐inflammatory cytokines IL‐1ß, IL‐6 and TNF‐α were analysed with ELISA. Immunohistochemistry was performed for inflammatory infiltration in exposed and contralateral eyes.

Results:  UVR‐B exposure induced cataract in all exposed lenses. There was additionally a significant UVR dose–dependent increase in light scattering in the lenses of the non‐exposed fellow eye. Inflammatory infiltration was detected immunohistochemically in the anterior segment of both eyes. IL‐1β serum concentration increased with increasing UVR‐B exposure dose. There was a similar trend for serum IL‐6 but not for TNF‐α.

Conclusion:  Unilateral UVR‐B exposure to one eye is associated with intraocular inflammation and an increase in lens light scattering also in the unexposed, fellow eye. A resulting systemic inflammatory response might be mediated by IL‐1β and possibly IL‐6. The finding that an inflammatory response may play a role in UVR‐B‐induced cataract development might initiate new strategies in the prevention of the disease.
Comparison of optic disc parameters using spectral domain cirrus high‐definition optical coherence tomography and confocal scanning laser ophthalmoscopy in normal eyes
Authors: Resch Hemma , Deak Gabor , Pereira Ivania , Vass Clemens
Published: March 2012

Purpose:  To compare Cirrus HD – optical coherence tomography (HD‐OCT) with confocal scanning laser ophthalmoscopy (HRT 3) for analysis of optic disc parameters in healthy eyes.

Methods:  In 126 subjects, cup volume (CV), vertical cup/disc ratio (CDR), neuroretinal rim area (NRA), cup area (CA) and optic disc area (ODA) were measured with the Cirrus HD‐OCT and HRT 3. These optic disc parameters were chosen for statistical analysis because they can be analysed in both OCT and HRT 3 and they are widely used parameters for glaucoma assessment.

Results:  Mean values and significances of paired t‐tests for OCT and HRT were for CV: 0.099 ± 0.11 versus 0.082 ± 0.10 (p < 0.001), CA: 0.42 ± 0.31 versus 0.39 ± 0.31 (p < 0.001), CDR: 0.36 ± 0.17 versus 0.27 ± 0.21 (p < 0.001). NRA and ODA were not significantly different between instruments. The Pearson coefficients were 0.905 (CV), 0.824 (CA), 0.734 (CDR), 0.295 (NRA) and 0.378 (ODA).

Conclusion:  To our interpretation, the delineation of the optic disc border is error‐prone with both instruments and all parameters directly depending on it are thus poorly correlated. However, the determination of the optic disc excavation (CV and CA) appears comparable taking into account a small systematic difference between instruments.
Choroidal hemodynamic in myopic patients with and without primary open‐angle glaucoma
Authors: Samra Waleed Abou , Pournaras Constantin , Riva Charles , Emarah Mohammed
Published: March 2012

Purpose:  To investigate the change in subfoveal choroidal blood flow in patients with glaucoma and to assess the effect of myopia, as one of the vascular risk factors for glaucoma on this flow.

Methods:  Subfoveal choroidal blood flow in groups of 12 myopic and glaucomatous eyes has been investigated by means of the laser Doppler flowmetry (LDF), comparing the results with those of 17 myopic eyes without glaucoma, 34 non‐myopic glaucomatous eyes and of 50 control eyes. The subfoveal choroidal LDF parameters, that is, blood velocity (ChBVel), volume (ChBVol), and flow (ChBF), as well as the vascular resistance were studied in each group. Statistical analysis was performed by means of anova and t‐test according to the Bonferroni procedure for multiple comparisons. Pearson correlation was used to establish the correlations between the hemodynamic parameters and the degree of myopia in dioptres.

Results:  All LDF parameters (ChBVel, ChBVol and ChBF) were significantly reduced in glaucomatous patients (1.3 ± 0.4, 0.14 ± 0.06 and 4 ± 2 respectively) and myopic patients with primary open‐angle glaucoma (POAG) (1.3 ± 0.4, 0.08 ± 0.04 and 2 ± 0.7 respectively) and without POAG (1.2 ± 0.3, 0.11 ± 0.08 and 2 ± 1 respectively) in comparison with age‐matched controls (1.5 ± 0.4, 0.27 ± 0.1 and 8 ± 2 respectively). On the other hand, the choroidal vascular resistance (Rm) was increased in the previously described studied patients groups (16 ± 7, 26 ± 9 and 24 ± 9 respectively) compared with controls (7 ± 2). The LDF parameters did not differ significantly between myopic subjects without and with POAG (p = 0.09, p = 0.09, p = 0.2, p = 0.08 and p = 0.9 respectively). Compared to patients with emmetropic glaucomatous, significant reduction in the ChBVol and ChBF and increased Rm were recorded in patients with glaucomatous myopia (p = 0.05, p = 0.04 and p = 0.04 respectively).

Pearson correlation demonstrated a significant correlation between the degree of myopia in dioptres and the ChBF (p = 0.012).

Conclusions:  The subfoveal choroidal LDF parameters were reduced in patients with POAG and myopia. Theses alterations are more in glaucomatous patients with myopia in comparison with age‐matched glaucomatous patients without myopia. These data suggest that the impaired choroidal circulation caused by myopia might be an important additional risk factor involved in the glaucomatous damaging process.
Comparison of Naftopidil 75 mg with Tamsulosin Hydrochloride 0.2 mg in the Treatment of Lower Urinary Tract Symptoms with Benign Prostatic Hyperplasia
Authors: SHIGEMURA Katsumi , YAMAMICHI Fukashi , MATSUMOTO Minori , TANAKA Kazushi , YAMASHITA Masuo , ARAKAWA Soichi , FUJISAWA Masato
Published: March 2012

Objective: To compare the efficacy of two α1‐adrenoceptor antagonists, α1D‐adrenoceptor‐selective naftopidil (Naf) 75 mg and α1A‐adrenoceptor‐selective tamsulosin hydrochloride (Tam) 0.2 mg, for the treatment of lower urinary tract symptoms (LUTS) in men with benign prostatic hyperplasia (BPH).

Methods: Seventy‐seven patients with LUTS secondary to BPH were enrolled. Data were gathered from patients retrospectively: 41 patients who were prescribed Naf 75 mg for 4 weeks and 36 patients who were prescribed Tam 0.2 mg for 4 weeks, respectively. The efficacy criteria were improvement in LUTS International Prostate Symptom Score (IPSS) and quality of life (QOL) scores after dosing.

Results: Naf 75 mg significantly improved symptoms in all 11 categories (overall IPSS, incomplete emptying, voiding symptoms [Intermittency, poor flow and straining], storage symptoms [daytime frequency, urgency and nocturia frequency], QOL index, intermittency, poor flow, straining, daytime frequency, urgency, and nocturia frequency) (P < 0.05). Tam 0.2 mg significantly suppressed 10 of the 11 tested symptom categories except straining (P < 0.05). Comparison data of the two drugs tended to show Naf 75 mg had better efficacy on nocturia frequency than Tam 0.2 mg (P < 0.05).

Conclusion: Naf 75 mg might show a better efficacy for LUTS with BPH in nocturia frequency than Tam 0.2 mg.
Apremilast in the Treatment of Chronic Prostatitis/Chronic Pelvic Pain Syndrome: A Pilot Study
Authors: McLENNAN Gregory P. , KHOURDAJI Iyad , KILLINGER Kim A. , BOURA Judith A. , PETERS Kenneth M.
Published: March 2012

Objective: Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is a disease with an uncertain cause and limited effective treatments. Apremilast (Celgene Corporation, Summit, NJ, USA) is a selective phosphodiesterase type 4 (PDE4) inhibitor that modulates the immune system. An open‐label, one‐arm, pilot study was conducted to explore its potential for improving CP/CPPS symptoms.

Methods: Males ≥ 18 years of age were treated with 20 mg oral apremilast twice daily for up to 12 weeks. Outcomes were measured with Global Response Assessment (GRA), pain visual analog scale (VAS), Chronic Prostatitis Symptom Index (CPSI), Pittsburgh Sleep Quality Index (PSQI), SF‐12 mental (MCS) and physical (PCS) health‐related quality of life subscales, and voiding diaries. Repeated measures and paired t‐tests evaluated changes from baseline to end of treatment, and at a final visit 4 weeks off the drug.

Results: Seventeen men (94% Caucasian; mean age 48.2 ± 10 years) were treated (mean 115.8 ± 56.1 doses). Mean VAS (3.4 ± 2.0 vs 1.8 ± 1.7; P = 0.0011), PSQI (9.4 ± 4.4 vs 7.4 ± 4.2; P = 0.037) and CPSI (26.1 ± 5.0 vs 17.2 ± 8.3; P = 0.0016) scores improved from baseline to end of treatment. Incontinence episodes per day improved slightly (P = 0.042). When only those completing at least 8 weeks of treatment were examined (n = 9), significant changes in CPSI, VAS, and PSQI were still observed. At the final visit, 8/9 (88.9%) men also reported some improvement in pain related to sex. Side‐effects were generally mild and well tolerated.

Conclusion: These results suggest that apremilast may improve CP/CPPS symptoms with only mild side‐effects. However, placebo controlled studies are necessary to determine efficacy.
Fish to meat intake ratio and cooking oils are associated with hepatitis C virus carriers with persistently normal alanine aminotransferase levels
Authors: Otsuka Momoka , Uchida Yuki , Kawaguchi Takumi , Taniguchi Eitaro , Kawaguchi Atsushi , Kitani Shingo , Itou Minoru , Oriishi Tetsuharu , Kakuma Tatsuyuki , Tanaka Suiko , Yagi Minoru , Sata Michio
Published: March 2012

Aim:  Dietary habits are involved in the development of chronic inflammation; however, the impact of dietary profiles of hepatitis C virus carriers with persistently normal alanine transaminase levels (HCV‐PNALT) remains unclear. The decision‐tree algorithm is a data‐mining statistical technique, which uncovers meaningful profiles of factors from a data collection. We aimed to investigate dietary profiles associated with HCV‐PNALT using a decision‐tree algorithm.

Methods:  Twenty‐seven HCV‐PNALT and 41 patients with chronic hepatitis C were enrolled in this study. Dietary habit was assessed using a validated semiquantitative food frequency questionnaire. A decision‐tree algorithm was created by dietary variables, and was evaluated by area under the receiver operating characteristic curve analysis (AUROC).

Results:  In multivariate analysis, fish to meat ratio, dairy product and cooking oils were identified as independent variables associated with HCV‐PNALT. The decision‐tree algorithm was created with two variables: a fish to meat ratio and cooking oils/ideal bodyweight. When subjects showed a fish to meat ratio of 1.24 or more, 68.8% of the subjects were HCV‐PNALT. On the other hand, 11.5% of the subjects were HCV‐PNALT when subjects showed a fish to meat ratio of less than 1.24 and cooking oil/ideal bodyweight of less than 0.23 g/kg. The difference in the proportion of HCV‐PNALT between these groups are significant (odds ratio 16.87, 95% CI 3.40–83.67, P = 0.0005). Fivefold cross‐validation of the decision‐tree algorithm showed an AUROC of 0.6947 (95% CI 0.5656–0.8238, P = 0.0067).

Conclusion:  The decision‐tree algorithm disclosed that fish to meat ratio and cooking oil/ideal bodyweight were associated with HCV‐PNALT.
Systematic review and meta‐analysis of randomized trials on probiotics for hepatic encephalopathy
Authors: Holte Kathrine , Krag Aleksander , Gluud Lise Lotte
Published: March 2012

Aim:  The objective of this systematic review and meta‐analysis was to assess the efficacy of probiotics and synbiotics in patients with hepatic encephalopathy.

Methods:  Eligible trials were identified by searching electronic databases including MEDLINE, the Cochrane Library, Science Citation Index and Embase, abstract proceedings, reference lists and ongoing trial registers until 13 October 2010. We included randomized controlled trials comparing probiotics and synbiotics with no intervention, placebo or lactulose in patients with hepatic encephalopathy. The primary outcome measure was improvement in hepatic encephalopathy. Results were expressed as risk rates (RR) with confidence intervals (CI) and intertrial heterogeneity as I2.

Results:  Seven trials with a total of 393 patients were analyzed. Compared to placebo or lactulose, treatment with probiotics or synbiotics significantly improved hepatic encephalopathy (RR = 1.40, 95% CI = 1.05–1.86, I2 = 5%). Probiotics decreased arterial ammonia (weighted mean difference 15.95; 95% CI = 26.72–3.28; I2 = 68%), but not venous ammonia (weighted mean difference 5.23; 95% CI = 21.77–11.30; I2 = 89%). Treatment with probiotics or synbiotics did not significantly affect the psychometric tests. Overall adverse events were reported in four trials with no difference between probiotics and placebo groups (RR = 0.32, 95% CI = 0.04–2.57; I2 = 59%). Regression analysis showed evidence of small‐study effects.

Conclusion:  The present meta‐analysis suggests that probiotics may be an effective treatment of hepatic encephalopathy, though rigorous evaluation in standardized, randomized, clinical trial with clinically relevant outcomes is still needed.
An Evaluation of the NERJIT Priority Rule in a Kanban‐Controlled Flowshop
Authors: Ardalan Alireza , Diaz Rafael
Published: March 2012

Significant progress in production and information technologies and innovations in management of operations during the last couple of decades have made the production of small lots and deployment of Just‐In‐Time (JIT) concepts in flowshops possible. As a result, some researchers and practitioners have been seeking to improve the performance of non‐repetitive systems using JIT concepts. In this process, the JIT concepts that were originally designed for mass production have been modified to adapt JIT to non‐repetitive systems. This article uses a priority rule that is based on real‐time demand and production information for sequencing jobs in a kanban‐controlled flowshop. The analysis of the effect of this priority rule; the number of kanbans; the length of the withdrawal cycle; First‐Come, First‐Served (FCFS); and Shortest Processing Time (SPT) on four performance measures—customer wait time, total inventory, input stock‐point inventory, and output stock‐point inventory, shows that the use of this priority rule results in a significant reduction of customer wait time and a slight decrease in inventory.
Equilibrium Financing in a Distribution Channel with Capital Constraint
Authors: Jing Bing , Chen Xiangfeng , Cai Gangshu (George)
Published: March 2012

There exist capital constraints in many distribution channels. We examine a channel consisting of one manufacturer and one retailer, where the retailer is capital constrained. The retailer may fund its business by borrowing credit either from a competitive bank market or from the manufacturer, provided the latter is willing to lend. When only one credit type (either bank or trade credit) is viable, we show that trade credit financing generally charges a higher wholesale price and thus becomes less attractive than bank credit financing for the retailer. When both bank and trade credits are viable, the unique equilibrium is trade credit financing if production cost is relatively low but is bank credit financing otherwise. We also study the case where both the retailer and the manufacturer are capital constrained and demonstrate that, to improve the overall supply chain efficiency, the bank should finance the manufacturer if production cost is low but finance the retailer otherwise. Our analysis further suggests that the equilibrium region of trade credit financing shrinks as demand variability or the retailer's internal capital level increases.
Targeted gene delivery to hepatocytes with galactosylated amphiphilic cyclodextrins
Authors: McMahon Anthony , O'Neill Martin J , Gomez Eva , Donohue Ruth , Forde Damien , Darcy Raphael , O'Driscoll Caitriona M
Published: March 2012

Objectives

Achieving targeted delivery of gene medicines is desirable to maximise activity. Here, galactosylated amphiphilic cyclodextrins (CDs) are examined in terms of their ability to transfect asialoglycoprotein receptor-bearing HepG2 cells.

Methods

Cationic amphiphilic CDs were synthesised as well as amphiphilic CDs bearing galactose-targeting ligands with different linker lengths. Binding of galactosylated CDs to a galactose-specific lectin was examined by surface plasmon resonance. CDs were formulated with and without the helper lipid DOPE and complexed with plasmid DNA. Transfection was evaluated by luciferase assay. Intracellular trafficking was assessed by confocal microscopy.

Key findings

Binding of targeted CDs to a galactose-specific lectin was achieved. Binding decreased with linker length between the galactosyl group and the CD core. Contrary to the lectin binding results, transfection levels increased with an increase in linker length from 7 atoms to 15. Compared to non-targeted formulations, a significant increase in transfection was observed only in the presence of the helper lipid DOPE. Confocal microscopy revealed that DOPE caused a pronounced effect on cellular distribution.

Conclusions

The galactose-targeting ligand induced substantial increases in transfection over non-targeted formulations when DOPE was included, indicating the potential for targeted gene delivery using CD-based delivery systems.
Preschool‐aged children's understanding of gratitude: Relations with emotion and mental state knowledge
Authors: Nelson Jackie A. , de Lucca Freitas Lia Beatriz , O’Brien Marion , Calkins Susan D. , Leerkes Esther M. , Marcovitch Stuart
Published: March 2012

Developmental precursors to children's early understanding of gratitude were examined. A diverse group of 263 children was tested for emotion and mental state knowledge at ages 3 and 4, and their understanding of gratitude was measured at age 5. Children varied widely in their understanding of gratitude, but most understood some aspects of gratitude‐eliciting situations. A model‐building path analysis approach was used to examine longitudinal relations among early emotion and mental state knowledge and later understanding of gratitude. Children with a better early understanding of emotions and mental states understand more about gratitude. Mental state knowledge at age 4 mediated the relation between emotion knowledge at age 3 and gratitude understanding at age 5. The current study contributes to the scant literature on the early emergence of children's understanding of gratitude.
Effect of Near-Wall Turbulence on Selective Removal of Particles From Sand Beds Deposited in Pipelines
Authors: Zeinali Hossein , Toma Peter , Kuru Ergun
Published: April 2012

This paper investigates the effect of near-wall turbulence on selective removal of small-size particulate matter from sand beds deposited in pipelines. In an effort to develop effective strategies for in-line fines separation, experimental data on selective particle removal by burst-sweep turbulent structures have been gathered. A 3¾″ (0.095 m) diameter—15 m long flow loop together with a particle image velocimetry (PIV) system has been commissioned and used for observations of turbulent burst activities. The flow loop was also equipped with bottom extractors to allow real time sampling of deposited particles which are then analyzed for determining particle size distribution changes with time. In this work, the alteration of size-composition during turbulent transportation of moving (sand) bed was assumed to be the effect of burst-sweep activity (coherent structures). The frequency of coherent burst structures was measured at various distances from the pipe wall, during the radial dissipation, and results were compared with existing literature. The experimental results indicated that when a bed of particles with 0.1–50 μm size range is exposed to burst-sweep activities during turbulent pipe flow, the concentration of fine particles within the bed increases with time (i.e., coarser particles are preferentially removed).
Impacts of Hematite Nanoparticle Exposure on Biomechanical, Adhesive, and Surface Electrical Properties of Escherichia coli Cells
Authors: Zhang Wen , Hughes Joseph , Chen Yongsheng
Published: March 2012

Despite a wealth of studies examining the toxicity of engineered nanomaterials, current knowledge on their cytotoxic mechanisms (particularly from a physical perspective) remains limited. In this work, we imaged and quantitatively characterized the biomechanical (hardness and elasticity), adhesive, and surface electrical properties of
Escherichia coli
cells with and without exposure to hematite nanoparticles (NPs) in an effort to advance our understanding of the cytotoxic impacts of nanomaterials. Both scanning electron microscopy (SEM) and atomic force microscopy (AFM) showed that
E. coli
cells had noticeable deformation with hematite treatment for 45 min with a statistical significance. The hematite-treated cells became significantly harder or stiffer than untreated ones, as evidenced by indentation and spring constant measurements. The average indentation of the hematite-treated
E. coli
cells was 120 nm, which is significantly lower (
P
< 0.01) than that of the untreated cells (approximately 400 nm). The spring constant of hematite-treated
E. coli
cells (0.28 ± 0.11 nN/nm) was about 20 times higher than that of untreated ones (0.01 ± 0.01 nN/nm). The zeta potential of
E. coli
cells, measured by dynamic light scattering (DLS), was shown to shift from −4 ± 2 mV to −27 ± 8 mV with progressive surface adsorption of hematite NPs, a finding which is consistent with the local surface potential measured by Kelvin probe force microscopy (KPFM). Overall, the reported findings quantitatively revealed the adverse impacts of nanomaterial exposure on physical properties of bacterial cells and should provide insight into the toxicity mechanisms of nanomaterials.
Composition and Seasonal Variation of Rhipicephalus turanicus and Rhipicephalus sanguineus Bacterial Communities
Authors: Lalzar Itai , Harrus Shimon , Mumcuoglu Kosta Y. , Gottlieb Yuval
Published: March 2012

A 16S rRNA gene approach, including 454 pyrosequencing and quantitative PCR (qPCR), was used to describe the bacterial community in
Rhipicephalus turanicus
and to evaluate the dynamics of key bacterial tenants of adult ticks during the active questing season. The bacterial community structure of
Rh. turanicus
was characterized by high dominance of
Coxiella
and
Rickettsia
and extremely low taxonomic diversity. Parallel diagnostic PCR further revealed a novel
Coxiella
species which was present and numerically dominant in all individual ticks tested (
n
= 187).
Coxiella
sp. densities were significantly higher in female versus male ticks and were overall stable throughout the questing season. In addition, we revealed the presence of the novel
Coxiella
sp. in
Rh. sanguineus
adult ticks, eggs, and hatched larvae, indicating its vertical transmission. The presence of both spotted fever group
Rickettsia
spp. (SFGR) and non-SFGR was verified in the various individual ticks. The prevalence and density of
Rickettsia
spp. were very low compared to those of
Coxiella
sp. Furthermore,
Rickettsia
sp. densities were similar in males and females and significantly declined toward the end of the questing season. No correlation was found between
Coxiella
sp. and
Rickettsia
sp. densities. These results suggest different control mechanisms in the tick over its different bacterial populations and point to an obligatory and facultative association between the two tick species and
Coxiella
sp. and
Rickettsia
spp., respectively.
Contact-Free Inactivation of Candida albicans Biofilms by Cold Atmospheric Air Plasma
Authors: Maisch Tim , Shimizu Tetsuji , Isbary Georg , Heinlin Julia , Karrer Sigrid , Klämpfl Tobias G. , Li Yang-Fang , Morfill Gregor , Zimmermann Julia L.
Published: March 2012

Candida albicans
is one of the main species able to form a biofilm on almost any surface, causing both skin and superficial mucosal infections. The worldwide increase in antifungal resistance has led to a decrease in the efficacy of standard therapies, prolonging treatment time and increasing health care costs. Therefore, the aim of this work was to demonstrate the applicability of atmospheric plasma at room temperature for inactivating
C. albicans
growing in biofilms without thermally damaging heat-sensitive materials. This so-called cold atmospheric plasma is produced by applying high voltage to accelerate electrons, which ionize the surrounding air, leading to the production of charged particles, reactive species, and photons. A newly developed plasma device was used, which exhibits a large plasma-generating surface area of 9 by 13 cm (117 cm
2
). Different time points were selected to achieve an optimum inactivation efficacy range of ≥3 log
10
to 5 log
10
reduction in CFU per milliliter, and the results were compared with those of 70% ethanol. The results obtained show that contact-free antifungal inactivation of
Candida
biofilms by cold atmospheric plasma is a promising tool for disinfection of surfaces (and items) in both health care settings and the food industry, where ethanol disinfection should be avoided.
Selected Antimicrobial Essential Oils Eradicate Pseudomonas spp. and Staphylococcus aureus Biofilms
Authors: Kavanaugh Nicole L. , Ribbeck Katharina
Published: March 2012

Biofilms are difficult to eliminate with standard antimicrobial treatments due to their high antibiotic resistance relative to free-living cells. Here, we show that selected antimicrobial essential oils can eradicate bacteria within biofilms with higher efficiency than certain important antibiotics, making them interesting candidates for the treatment of biofilms.
Role of Aspergillus niger
acrA
in Arsenic Resistance and Its Use as the Basis for an Arsenic Biosensor
Authors: Choe Se-In , Gravelat Fabrice N. , Al Abdallah Qusai , Lee Mark J. , Gibbs Bernard F. , Sheppard Donald C.
Published: March 2012

Arsenic contamination of groundwater sources is a major issue worldwide, since exposure to high levels of arsenic has been linked to a variety of health problems. Effective methods of detection are thus greatly needed as preventive measures. In an effort to develop a fungal biosensor for arsenic, we first identified seven putative arsenic metabolism and transport genes in
Aspergillus niger
, a widely used industrial organism that is generally regarded as safe (GRAS). Among the genes tested for RNA expression in response to arsenate,
acrA
, encoding a putative plasma membrane arsenite efflux pump, displayed an over 200-fold increase in gene expression in response to arsenate. We characterized the function of this
A. niger
protein in arsenic efflux by gene knockout and confirmed that AcrA was located at the cell membrane using an enhanced green fluorescent protein (eGFP) fusion construct. Based on our observations, we developed a putative biosensor strain containing a construct of the native promoter of
acrA
fused with
egfp
. We analyzed the fluorescence of this biosensor strain in the presence of arsenic using confocal microscopy and spectrofluorimetry. The biosensor strain reliably detected both arsenite and arsenate in the range of 1.8 to 180 μg/liter, which encompasses the threshold concentrations for drinking water set by the World Health Organization (10 and 50 μg/liter).
Efficient Production of Polymyxin in the Surrogate Host Bacillus subtilis by Introducing a Foreign
ectB
Gene and Disrupting the
abrB
Gene
Authors: Park Soo-Young , Choi Soo-Keun , Kim Jihoon , Oh Tae-Kwang , Park Seung-Hwan
Published: March 2012

In our previous study,
Bacillus subtilis
strain BSK3S, containing a polymyxin biosynthetic gene cluster from
Paenibacillus polymyxa
, could produce polymyxin only in the presence of exogenously added
l
-2,4-diaminobutyric acid (Dab). The dependence of polymyxin production on exogenous Dab was removed by introducing an
ectB
gene encoding the diaminobutyrate synthase of
P. polymyxa
into BSK3S (resulting in strain BSK4). We found, by observing the complete inhibition of polymyxin synthesis when the
spo0A
gene was knocked out (strain BSK4-0A), that Spo0A is indispensable for the production of polymyxin. Interestingly, the
abrB-spo0A
double-knockout mutant, BSK4-0A-rB, and the single
abrB
mutant, BSK4-rB, showed 1.7- and 2.3-fold increases, respectively, in polymyxin production over that of BSK4. These results coincided with the transcription levels of
pmxA
in the strains observed by quantitative real-time PCR (qRT-PCR). The AbrB protein was shown to bind directly to the upstream region of
pmxA
, indicating that AbrB directly inhibits the transcription of polymyxin biosynthetic genes. The BSK4-rB strain, producing high levels of polymyxin, will be useful for the development and production of novel polymyxin derivatives.
Soil Fungal Cellobiohydrolase I Gene (
cbhI
) Composition and Expression in a Loblolly Pine Plantation under Conditions of Elevated Atmospheric CO
2
and Nitrogen Fertilization
Authors: Weber Carolyn F. , Balasch Monica Moya , Gossage Zachary , Porras-Alfaro Andrea , Kuske Cheryl R.
Published: March 2012

The simultaneous increase of atmospheric CO
2
and nitrogen (N) deposition to terrestrial ecosystems is predicted to alter plant productivity and, consequently, to change the amount and quality of above- and belowground carbon entering forest soils. It is not known how such changes will impact the composition and function of soil fungal communities that play a key role in degrading complex carbon. We sequenced the fungal cellobiohydrolase I gene (
cbhI
) from soil DNA and cDNA to compare the richness and composition of resident and expressed
cbhI
genes at a U.S. Department of Energy free air-carbon dioxide enrichment (FACE) site (NC), which had been exposed to elevated atmospheric CO
2
and/or N fertilization treatment for several years. Our results provide evidence that the richness and composition of the cellulolytic fungi surveyed in this study were distinct in the DNA- and cDNA-based gene surveys and were dominated by Basidiomycota that have low or no representation in public databases. The surveys did not detect differences in richness or phylum-level composition of
cbhI
-containing, cellulolytic fungi that correlated with elevated CO
2
or N fertilization at the time of sampling.
Biofilms Reduce Solar Disinfection of Cryptosporidium parvum Oocysts
Authors: Wolyniak DiCesare E. A. , Hargreaves B. R. , Jellison K. L.
Published: March 2012

Solar radiation reduces
Cryptosporidium
infectivity. Biofilms grown from stream microbial assemblages inoculated with oocysts were exposed to solar radiation. The infectivity of oocysts attached at the biofilm surface and oocysts suspended in water was about half that of oocysts attached at the base of a 32-μm biofilm.
Analysis of the Conformation and Function of the Plasmodium falciparum Merozoite Proteins MTRAP and PTRAMP
Authors: Uchime Onyinyechukwu , Herrera Raul , Reiter Karine , Kotova Svetlana , Shimp Richard L. , Miura Kazutoyo , Jones Dominique , Lebowitz Jacob , Ambroggio Xavier , Hurt Darrell E. , Jin Albert J. , Long Carole , Miller Louis H. , Narum David L.
Published: March 2012

Thrombospondin repeat (TSR)-like domains are structures involved with cell adhesion.
Plasmodium falciparum
proteins containing TSR domains play crucial roles in parasite development. In particular, the preerythrocytic
P. falciparum
circumsporozoite protein is involved in hepatocyte invasion. The importance of these domains in two other malaria proteins, the merozoite-specific thrombospondin-related anonymous protein (MTRAP) and the thrombospondin-related apical membrane protein (PTRAMP), were assessed using near-full-length recombinant proteins composed of the extracellular domains produced in
Escherichia coli
. MTRAP is thought to be released from invasive organelles identified as micronemes during merozoite invasion to mediate motility and host cell invasion through an interaction with aldolase, an actin binding protein involved in the moving junction. PTRAMP function remains unknown. In this study, the conformation of recombinant MTRAP (rMTRAP) appeared to be a highly extended protein (2 nm by 33 nm, width by length, respectively), whereas rPTRAMP had a less extended structure. Using an erythrocyte binding assay, rMTRAP but not rPTRAMP bound human erythrocytes; rMTRAP binding was mediated through the TSR domain. MTRAP- and in general PTRAMP-specific antibodies failed to inhibit
P. falciparum
development
in vitro
. Altogether, MTRAP is a highly extended bifunctional protein that binds to an erythrocyte receptor and the merozoite motor.
Functional Analysis of Sequence Motifs Involved in the Polyadenylation of Trichomonas vaginalis mRNAs
Authors: Fuentes Vanessa , Barrera Guadalupe , Sánchez Joaquín , Hernández Roberto , López-Villaseñor Imelda
Published: March 2012

Synthesis of functional mRNA in eukaryotes involves processing of precursor transcripts, including the addition of a poly(A) tail at the 3′ end. A multiprotein complex recognizes a polyadenylation signal, generally the hexanucleotide AAUAAA in metazoans, to direct processing of the pre-mRNA. Based on sequence analysis of several cDNAs, we have previously suggested that the UAAA tetranucleotide (which may include the UAA translation stop codon) could be the polyadenylation signal in
Trichomonas vaginalis
, a parasitic protozoon that causes human trichomoniasis. This proposal is analyzed here with the aid of a transient-expression system of a reporter gene (
cat
flanked by
T. vaginalis
actin noncoding sequences). When cells were transfected with a plasmid bearing the original 3′ untranslated region (UTR) sequence containing the UAAA motif, the resulting
cat
mRNA was polyadenylated similarly to the endogenous actin mRNA. Base changes in the UAAA sequence produced alterations to the polyadenylation site of the reporter mRNAs, while nucleotide substitutions at either side of UAAA did not. Furthermore, relocation of the UAAA motif redirected the processing and polyadenylation of the reporter mRNA. In addition, a pre-mRNA cleavage site for polyadenylation was defined. Interaction of
T. vaginalis
proteins with the UAAA motif was shown by electrophoretic mobility shift assays. Based on our findings, we provide evidence that in
T. vaginalis
the UAAA tetranucleotide has a role equivalent to that of the metazoan consensus AAUAAA polyadenylation signal.
The Structure of Mlc Titration Factor A (MtfA/YeeI) Reveals a Prototypical Zinc Metallopeptidase Related to Anthrax Lethal Factor
Authors: Xu Qingping , Göhler Anna-Katharina , Kosfeld Anne , Carlton Dennis , Chiu Hsiu-Ju , Klock Heath E. , Knuth Mark W. , Miller Mitchell D. , Elsliger Marc-André , Deacon Ashley M. , Godzik Adam , Lesley Scott A. , Jahreis Knut , Wilson Ian A.
Published: March 2012

MtfA of
Escherichia coli
(formerly YeeI) was previously identified as a regulator of the phosphoenolpyruvate (PEP)-dependent:glucose phosphotransferase system. MtfA homolog proteins are highly conserved, especially among beta- and gammaproteobacteria. We determined the crystal structures of the full-length MtfA apoenzyme from
Klebsiella pneumoniae
and its complex with zinc (holoenzyme) at 2.2 and 1.95 Å, respectively. MtfA contains a conserved H
149
E
150
XXH
153
+E
212
+Y
205
metallopeptidase motif. The presence of zinc in the active site induces significant conformational changes in the region around Tyr205 compared to the conformation of the apoenzyme. Additionally, the zinc-bound MtfA structure is in a self-inhibitory conformation where a region that was disordered in the unliganded structure is now observed in the active site and a nonproductive state of the enzyme is formed. MtfA is related to the catalytic domain of the anthrax lethal factor and the Mop protein involved in the virulence of
Vibrio cholerae
, with conservation in both overall structure and in the residues around the active site. These results clearly provide support for MtfA as a prototypical zinc metallopeptidase (gluzincin clan).
Stress Response and Virulence Functions of the Acinetobacter baumannii NfuA Fe-S Scaffold Protein
Authors: Zimbler Daniel L. , Park Thomas M. , Arivett Brock A. , Penwell William F. , Greer Samuel M. , Woodruff Tessa M. , Tierney David L. , Actis Luis A.
Published: March 2012

To successfully establish an infection,
Acinetobacter baumannii
must overcome the iron starvation and oxidative stress imposed by the human host. Although previous studies have shown that ATCC 19606
T
cells acquire iron via the acinetobactin-mediated siderophore system, little is known about intracellular iron metabolism and its relation to oxidative stress in this pathogen. Screening of an insertion library resulted in the isolation of the ATCC 19606
T
derivative 1644, which was unable to grow in iron-chelated media. Rescue cloning and DNA sequencing showed that the insertion inactivated a gene coding for an NfuA Fe-S cluster protein ortholog, without any effect on the expression of the acinetobactin system. The
nfuA
mutant was also more sensitive to hydrogen peroxide and cumene hydroperoxide than the parental strain. The iron chelation- and oxidative-stress-deficient responses of this mutant were corrected when complemented with either the ATCC 19606
T
parental allele or the
Escherichia coli
MG1655
nfuA
ortholog. Furthermore, electron paramagnetic resonance (EPR) and inductively coupled plasma-atomic emission spectroscopy (ICP-AES) analyses showed that the ATCC 19606
T
NfuA ortholog has iron-binding properties compatible with the formation of [Fe-S] cluster protein.
Ex vivo
and
in vivo
assays using human epithelial cells and
Galleria mellonella
, respectively, showed that NfuA is critical for bacterial growth independent of their capacity to acquire iron or the presence of excess of free iron. Taken together, these observations indicate that the
A. baumannii
NfuA ortholog plays a role in intracellular iron utilization and protection from oxidative-stress responses that this pathogen could encounter during the infection of the human host.
Transcription Activation by NtcA in the Absence of Consensus NtcA-Binding Sites in an Anabaena Heterocyst Differentiation Gene Promoter
Authors: Camargo Sergio , Valladares Ana , Flores Enrique , Herrero Antonia
Published: March 2012

Heterocyst differentiation is orchestrated by the N control transcriptional regulator NtcA and the differentiation-specific factor HetR. In
Anabaena
sp. strain PCC 7120, the
devBCA
operon is expressed from two different promoters activated upon N stepdown. The distal
devB
promoter (transcription start point [TSP] located at position −704) represents a canonical class II NtcA-activated promoter, including a consensus NtcA-binding site centered 39.5 nucleotides upstream from the TSP. Transcription activation from a second TSP (−454) requires NtcA and is impaired in
hetR
mutants. In a wild-type background, three different DNA fragments, including both or each individual promoter, directed
gfp
expression localized mainly to proheterocysts and heterocysts. Expression was undetectable in an
ntcA
background and, for the fragment including the proximal promoter alone, also in a
hetR
background. In spite of the absence of consensus NtcA-binding sequences between the two TSPs, NtcA was shown to interact with this DNA region, and NtcA and its effector, 2-oxoglutarate, were necessary and sufficient for
in vitro
transcription from the −454 TSP. No HetR binding to the DNA or
in vitro
transcription from the proximal
devB
TSP promoted by HetR alone were detected. However, a moderate positive effect of HetR on NtcA binding to the DNA between the two
devB
TSPs was observed. The proximal
devB
promoter appears to represent a suboptimal NtcA-activated promoter for which HetR may act as a coactivator, with the physiological effect of restricting gene activation to conditions of prevalence of high NtcA and HetR levels, such as those taking place during heterocyst differentiation.