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    Effect of some biotic factors on microbially-induced calcite precipitation in cement mortar

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    AbstractSporosarcina pasteurii, a common soil bacterium has been tested for microbial treatment of cement mortar. The present study also seeks to investigate the effects of growth medium, bacterial concentration and different buffers concerning the preparation of bacterial suspensions on the compressive strength of cement mortar. Two growth media, six different suspensions and two bacterial concentrations were used in the study. The influence of growth medium on calcification efficiency of S. pasteurii was insignificant. Significant improvement in the compressive as well as the tensile strength of cement mortar was observed. Microbial mineral precipitation visualized by Scanning Electron Microscopy (SEM) shows fibrous material that increased the strength of cement mortar. Formation of thin strands of fillers observed through SEM micrographs improves the pore structure, impermeability and thus the compressive as well as the tensile strengths of the cement mortar. The type of substrate and its molarity have a significant influence on the strength of cement mortar

    Training response inhibition to reduce food consumption: Mechanisms, stimulus specificity and appropriate training protocols

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    AbstractTraining individuals to inhibit their responses towards unhealthy foods has been shown to reduce food intake relative to a control group. Here we aimed to further explore these effects by investigating the role of stimulus devaluation, training protocol, and choice of control group. Restrained eaters received either inhibition or control training using a modified version of either the stop-signal or go/no-go task. Following training we measured implicit attitudes towards food (Study 1) and food consumption (Studies 1 and 2). In Study 1 we used a modified stop-signal training task with increased demands on top-down control (using a tracking procedure and feedback to maintain competition between the stop and go processes). With this task, we found no evidence for an effect of training on implicit attitudes or food consumption, with Bayesian inferential analyses revealing substantial evidence for the null hypothesis. In Study 2 we removed the feedback in the stop-signal training to increase the rate of successful inhibition and revealed a significant effect of both stop-signal and go/no-go training on food intake (compared to double-response and go training, respectively) with a greater difference in consumption in the go/no-go task, compared with the stop-signal task. However, results from an additional passive control group suggest that training effects could be partly caused by increased consumption in the go control group whereas evidence for reduced consumption in the inhibition groups was inconclusive. Our findings therefore support evidence that inhibition training tasks with higher rates of inhibition accuracy are more effective, but prompt caution for interpreting the efficacy of laboratory-based inhibition training as an intervention for behaviour change

    Xanthogranulomatous Prostatitis, a Rare Prostatic Entity

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    AbstractThere are several benign prostatic pathologies that can clinically mimic a prostate adenocarcinoma. Xanthogranulomatous prostatitis is a benign inflammatory condition of the prostate and a rare entity. A 47-year old male, with 3 years of lower urinary tract symptoms, with a palpable hypogastric tumor, digital rectal examination: solid prostate, of approximately 60 g. Initial PSA was 0.90 ng/mL. He underwent surgical excision of the lower abdominal nodule and prostatectomy. Histopathology showed xanthogranulomatous prostatitis, without malignancy. Xanthogranulomatous prostatitis is an extremely rare entity that can simulate prostate adenocarcinoma, therefore having a correct histopathological diagnosis is essential

    Cu-Ni-PGE mineralisation at the Aurora Project and potential for a new PGE province in the Northern Bushveld Main Zone

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    AbstractThe Aurora Project is a Cu-Ni-PGE magmatic sulphide deposit in the northern limb of the Bushveld Complex of South Africa. Since 1992 mining in the northern limb has focussed on the Platreef deposit, located along the margin of the complex. Aurora has previously been suggested to represent a far-northern facies of the Platreef located along the basal margin of the complex and this study provides new data with which to test this assertion. In contrast to the Platreef, the base metal sulphide mineralisation at Aurora is both Cu-rich (Ni/Cu <1) and Au-rich. The sulphides are hosted predominantly in leucocratic rocks (gabbronorites and leucogabbronorites) with low Cr/MgO (<30) where pigeonite and orthopyroxene co-exist as low-Ca pyroxenes without cumulus magnetite. This mineral association is found in the Upper Main Zone and the Aurora mineral chemistry is consistent with this stratigraphic interval. Pigeonite gabbronorites above the Aurora mineralisation have high Cu/Pd ratios (>50,000) reflecting the preferential removal of Pd over Cu in the sulphides below. Similarly high Cu/Pd ratios characterise the Upper Main Zone in the northern limb above the pigeonite+orthopyroxene interval and suggest that Aurora-style sulphide mineralisation may be developed here as well. The same mineralogy and geochemical features also appear to be present in the T Zone of the Waterberg PGE deposit, located under younger cover rocks to the north of Aurora. If these links are proved they indicate the potential for a previously unsuspected zone of Cu-Ni-PGE mineralisation extending for over 40km along strike through the Upper Main Zone of the northern Bushveld

    A new LPV modeling approach using PCA-based parameter set mapping to design a PSS

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    AbstractThis paper presents a new methodology for the modeling and control of power systems based on an uncertain polytopic linear parameter-varying (LPV) approach using parameter set mapping with principle component analysis (PCA). An LPV representation of the power system dynamics is generated by linearization of its differential-algebraic equations about the transient operating points for some given specific faults containing the system nonlinear properties. The time response of the output signal in the transient state plays the role of the scheduling signal that is used to construct the LPV model. A set of sample points of the dynamic response is formed to generate an initial LPV model. PCA-based parameter set mapping is used to reduce the number of models and generate a reduced LPV model. This model is used to design a robust pole placement controller to assign the poles of the power system in a linear matrix inequality (LMI) region, such that the response of the power system has a proper damping ratio for all of the different oscillation modes. The proposed scheme is applied to controller synthesis of a power system stabilizer, and its performance is compared with a tuned standard conventional PSS using nonlinear simulation of a multi-machine power network. The results under various conditions show the robust performance of the proposed controller

    Dialysis Catheter–Related Bloodstream Infections: A Cluster-Randomized Trial of the ClearGuard HD Antimicrobial Barrier Cap

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    BackgroundThe rate of bloodstream infections (BSIs) is disproportionately high in hemodialysis (HD) patients with central venous catheters (CVCs) versus those with permanent accesses, contributing to poorer outcomes, such as increased rates of death and hospitalizations.Study Design12-month, prospective, cluster-randomized, multicenter, open-label trial.Setting & Participants40 Fresenius Medical Care North America dialysis facilities were matched and paired by positive blood culture rate and number of patients with CVCs and then cluster-randomized with 20 in each study group. 2,470 patients participated in the study (1,245, intervention group; 1,225, control group), accruing approximately 350,000 CVC-days.InterventionUse of ClearGuard HD Antimicrobial Barrier Caps versus use of standard CVC caps; assigned at the facility level.OutcomePrimary end point was positive blood culture rate as an indicator of BSI rate.MeasurementsPositive blood cultures, hospital admissions for BSI, hospitalization-days for BSI, intravenous antibiotic starts, and CVC-days.ResultsBaseline positive blood culture rates were similar (P=0.8) between groups. Use of ClearGuard HD caps for 12 months was associated with a 56% lower BSI rate versus use of standard CVC caps (0.26 vs 0.59/1,000 CVC-days, respectively; P=0.01). When considering sustained use (defined as last 6 months of the study), the intervention versus the control was associated with a 69% lower BSI rate (0.22 vs 0.72/1,000 CVC-days, respectively; P=0.01), 43% fewer hospital admissions for BSI (0.28 vs 0.48/1,000 CVC-days, respectively; P=0.04), and 51% fewer hospitalization days for BSI (2.42 vs 4.94/1,000 CVC-days, respectively; P=0.04). No device-related adverse events were reported.LimitationsStudy was open label; patients occasionally received HD at nonresearch facilities; patients did not receive the intervention when hospitalized.ConclusionsThe findings show that use of ClearGuard HD Antimicrobial Barrier Caps, when compared with standard CVC caps, significantly lowers rates of catheter-related BSIs and hospital admissions for BSI in HD patients using CVCs

    Synthesis, spectroscopic characterization and antibacterial screening of novel Mannich bases of Ganciclovir

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    AbstractBiologically active Mannich bases with heteroaromatic ring system of substituted guanine derivative (2-amino-9 [{(1,3 di hydroxy propane-2yl) oxy} methyl] 6-9 dihydro-3H-purine-6-one) (ganciclovir), have been synthesized via Mannich reaction. The aminomethylation of ganciclovir with various biologically potent sulphonamides was carried out and then characterized by elemental analysis and spectral studies – UV, IR, 1H NMR, powder X-ray diffraction and Scanning Electron Microscopy. The compounds were screened for their antibacterial activity against various pathogenic bacteria at varying concentrations. The antibacterial activity of derived Mannich bases was compared with parent sulphonamides. The toxicity of synthesized Mannich bases was ascertained by LD50 test

    A novel integrated modelling framework to assess the impacts of climate and socio-economic drivers on land use and water quality

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    AbstractChanges in climatic conditions will directly affect the quality and quantity of water resources. Further on, they will affect them indirectly through adaptation in land use which ultimately influences diffuse nutrient emissions to rivers and therefore potentially the compliance with good ecological status according to the EU Water Framework Directive (WFD). We present an integrated impact modelling framework (IIMF) to track and quantify direct and indirect pollution impacts along policy-economy-climate-agriculture-water interfaces. The IIMF is applied to assess impacts of climatic and socio-economic drivers on agricultural land use (crop choices, farming practices and fertilization levels), river flows and the risk for exceedance of environmental quality standards for determination of the ecological water quality status in Austria. This article also presents model interfaces as well as validation procedures and results of single models and the IIMF with respect to observed state variables such as land use, river flow and nutrient river loads. The performance of the IIMF for calculations of river nutrient loads (120 monitoring stations) shows a Nash-Sutcliffe Efficiency of 0.73 for nitrogen and 0.51 for phosphorus. Most problematic is the modelling of phosphorus loads in the alpine catchments dominated by forests and mountainous landscape. About 63% of these catchments show a deviation between modelled and observed loads of 30% and more. In catchments dominated by agricultural production, the performance of the IIMF is much better as only 30% of cropland and 23% of permanent grassland dominated areas have a deviation of >30% between modelled and observed loads. As risk of exceedance of environmental quality standards is mainly recognized in catchments dominated by cropland, the IIMF is well suited for assessing the nutrient component of the WFD ecological status

    Validation of Monte Carlo Geant4 code for a 6MV Varian linac

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    AbstractThis study is aimed at validating the Monte Carlo Geant4.9.4 code for a 6MV Varian linac configuring a 10×10cm2 radiation field. For this purpose a user-friendly Geant4 code called G4Linac has been developed from scratch allowing an accurate modeling of a 6MV Varian linac head and performing dose calculation in a homogeneous water phantom. Discarding the other accelerator parts where electrons are created, accelerated and deviated, a virtual source of 6MeV electrons was considered. The parameters associated with this virtual source are often unknown. Those parameters are mean energy, sigma and its full width at half maximum has been adjusted by following our own methodology that has been developed in such a manner that the optimization phase will be fast and efficient, in fact, a small number of Monte Carlo simulations has been conducted simultaneously on a cluster of computers thanks to the Rocks cluster software. The calculated dosimetric functions in a 40×40×40cm3 water phantom were compared to the measured ones thanks to the Gamma Index method, where the gamma criterion was fixed within 2%–1mm accuracy. After optimization, it was observed that the proper mean energy, sigma and its full width at half maximum are 5.6MeV, 0.42MeV and 1.177mm, respectively. Furthermore, we have made some changes in an existing bremsstrahlung splitting technique, due to which we have succeeded to reduce the CPU time spent by the treatment head simulation about five times

    Use of short-term steroids in the prophylaxis of atrial fibrillation after cardiac surgery

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    AbstractObjectivesTo assess the effectiveness of corticosteroids in the prophylaxis of postoperative atrial fibrillation (AF) in patients undergoing elective coronary artery bypass grafting or valvular heart surgery in terms of reducing its incidence and decreasing the length of hospital stay.MethodsThis prospective double blinded randomized study was conducted at Queen Alia Heart Institute (Amman, Jordan) from June 2014 to June 2015 on 340 patients who underwent their first on-pump elective coronary artery bypass grafting (CABG) alone or combined with valvular surgery. Inclusion criteria consisted of elective first time CABG or combined with valvular surgery, use of β-adrenergic blockade, and normal sinus rhythm. Exclusion criteria included a history of heart block, previous episodes of AF or flutter, uncontrolled diabetes mellitus, history of peptic ulcer disease, systemic bacterial or mycotic infection, permanent pacemaker, and any documented or suspected supraventricular or ventricular arrhythmias. Patients were randomized into two equal groups (n=170 each), then each group was subdivided into patients who underwent CABG alone (n=120), and patients underwent valvular heart surgery with or without CABG (n=50). In the treatment group, patients were given 1g of methylprednisolone before cardiopulmonary bypass then 100mg of hydrocortisone every 8 hours for the first 3days postoperatively. The primary endpoint was the overall occurrence of postoperative AF.ResultsAF developed in 21.1% (36 patients) in the treatment group in contrast to 38.2% (65 patients) in the control group (p<0.05). In the subdivided groups (CABG only), approximately 20% (24 patients) developed AF in the treatment group in contrast to 35% (42 patients) in the control group (p<0.05). In the other group, (CABG+VALVE) 24% (12 patients) developed AF compared with 46% (23 patients) in the control group (p<0.05). The length of hospital stay was 6.02±11.23days in the treatment group while it was 5.98±1.86days in the control group, which was found to be statistically nonsignificant. No statistical significant difference in the rate of postoperative complications including mediastinitis as well superficial wound infections was observed between the two groups.ConclusionProphylactic short-term use of steroids both intraoperatively and postoperatively proved to be safe and effective in reducing the incidence of postoperative AF in patients undergoing CABG alone or combined with valve surgery

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