264 research outputs found

    An accurate Rb density measurement method for a plasma wakefield accelerator experiment using a novel Rb reservoir

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    A method to accurately measure the density of Rb vapor is described. We plan on using this method for the Advanced Wakefield (AWAKE)~\cite{bib:awake} project at CERN , which will be the world's first proton driven plasma wakefield experiment. The method is similar to the hook~\cite{bib:Hook} method and has been described in great detail in the work by W. Tendell Hill et. al.~\cite{bib:densitymeter}. In this method a cosine fit is applied to the interferogram to obtain a relative accuracy on the order of 1%1\% for the vapor density-length product. A single-mode, fiber-based, Mach-Zenhder interferometer will be built and used near the ends of the 10 meter-long AWAKE plasma source to be able to make accurate relative density measurement between these two locations. This can then be used to infer the vapor density gradient along the AWAKE plasma source and also change it to the value desired for the plasma wakefield experiment. Here we describe the plan in detail and show preliminary results obtained using a prototype 8 cm long novel Rb vapor cell.Comment: 5 pages 9 figure

    A research on asymptomatic bacteriuria in 14- to 17-year-old female students

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    Urinary tract infections, which are more common in women than in men, are especially seen in young asymptomatic females who don't obey the general rules of hygiene. This research has been carried out on 14- to 17-year-old young females from several high schools, 966 specimens in total. 3.3% of them had bacteriuria and 75% of the isolated bacteria was Escherichia coli. Copyright © 2004 S. Karger AG, Basel

    Exploring the relationship between traffic resilience and driver behaviors through traffic climate

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    Traffic safety culture and climate have emerged as an integral part of road safety policy and practice in recent decades, resulting in an emphasis on a holistic approach to road safety through systems thinking. The aim of this study was to investigate the relationship between drivers' perceptions of traffic resilience and traffic climate and their impact on driver behaviors. A total of 216 drivers aged between 19 and 32 years completed an online questionnaire consisting of the Traffic Resilience Scale (TRS), the Traffic Climate Scale (TCS), the Driver Behavior Questionnaire (DBQ), and the Positive Driver Behaviors Scale (PDBS). Serial mediation analyses were conducted to examine the objectives of the study. The results showed that drivers who perceived the traffic system as more resilient tended to perceive the traffic system as more functional and less externally demanding. The drivers' perceptions of traffic resilience were found to be directly related to the traffic climate and indirectly related to the driver behaviors through external affective demands and internal requirements. Increased traffic resilience was associated with increased aberrant behaviors and decreased positive behaviors through reduced external affective demands and internal requirements. These findings can be considered to make a unique contribution to the literature in understanding the motivations behind aberrant behaviors of drivers and highlight the need for road safety policies to take into account road users' perceptions of traffic resilience and traffic climate in order to better understand, predict, and modify road user behaviors for a safer traffic system

    Uptake, accumulation and some biochemical responses in Raphanus sativus L. to zinc stress

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    The responses of radish (Raphanus sativus L.) to increasing concentrations of ZnCl2 (1, 5 and 10 mM) in Hoagland nutrient medium were studied. Under the conditions of these increasing zinc concentrations, the highest zinc accumulation was obtained in the roots of the plants treated with 10 mM applications. The zinc concentration in the vegetative parts, was highest in the root and was lowest in the cotyledons. The highest bioconcentration factor (BCF) value was detected in the roots in 5 mM zinc applications. When compared with the control, total zinc uptake was observed to increase in 1, 5 and 10 mM ZnCl2 treatments. The total accumulation rate (TAR) for zinc was highest in 10 mM ZnCl2 treatment, while the lowest TAR was observed in radish plants exposed to 1 mM ZnCl2. Plants treated with 5, 10 mM ZnCl2 showed significant decreases in chlorophyll (Chl a, Chl b, Chl a/b) and carotenoid content compared with the control. Peroxidase (POD) activity especially in radish roots increased significantly with increasing concentrations of ZnCl2 (5 and 10 mM) while the total protein amount decreased when compared with the control. The results of this study showed that, radish plants could tolerate the negative effects of zinc stress up to 1 mM ZnCl2 concentration and that in zinc concentrations of 5 mM and above toxic effects were existent.Key words: Radish, Raphanus sativus, zinc, metal toxicity, uptake, accumulation, peroxidase, pigment

    Time-Kill Kinetics and In Vitro Antifungal Susceptibility of Non-fumigatus Aspergillus Species Isolated from Patients with Ocular Mycoses

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    Aspergillus species can cause ocular morbidity and blindness, and thus, appropriate antifungal therapy is needed. We investigated the in vitro activity of itraconazole, voriconazole, posaconazole, caspofungin, anidulafungin, and amphotericin B against 14 Aspergillus isolates obtained from patients with ocular mycoses, using the CLSI reference broth microdilution methodology. In addition, time-kill assays were performed, exposing each isolate separately to 1-, 4-, and 16-fold concentrations above the minimum inhibitory concentration (MIC) of each antifungal agent. A sigmoid maximum-effect (Emax) model was used to fit the time-kill curve data. The drug effect was further evaluated by measuring an increase/decrease in the killing rate of the tested isolates. The MICs of amphotericin B, itraconazole, voriconazole, and posaconazole were 0.5–1.0, 1.0, 0.5–1.0, and 0.25 µg/ml for A. brasiliensis, A. niger, and A. tubingensis isolates, respectively, and 2.0–4.0, 0.5, 1.0 for A. flavus, and 0.12–0.25 µg/ml for A. nomius isolates, respectively. A. calidoustus had the highest MIC range for the azoles (4.0–16.0 µg/ml) among all isolates tested. The minimum effective concentrations of caspofungin and anidulafungin were ≤0.03–0.5 µg/ml and ≤0.03 µg/ml for all isolates, respectively. Posaconazole demonstrated maximal killing rates (Emax = 0.63 h−1, r2 = 0.71) against 14 ocular Aspergillus isolates, followed by amphotericin B (Emax = 0.39 h−1, r2 = 0.87), voriconazole (Emax = 0.35 h−1, r2 = 0.098), and itraconazole (Emax = 0.01 h−1, r2 = 0.98). Overall, the antifungal susceptibility of the non-fumigatusAspergillus isolates tested was species and antifungal agent dependent. Analysis of the kinetic growth assays, along with consideration of the killing rates, revealed that posaconazole was the most effective antifungal against all of the isolates

    Ion source and LEBT of KAHVELab proton beamline

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    The KAHVE Laboratory, at Bo\u{g}azi\c{c}i University, Istanbul, Turkey is home to an educational proton linac project. The proton beam will originate from a 20 keV H+ source and will be delivered to a two module Radio Frequency Quadrupole (RFQ) operating at 800 MHz via a low energy beam transport (LEBT) line. Currently, the design phase being over, commissioning and stability tests are ongoing for the proton beamline which is already produced and installed except the RFQ which is being manufactured. This work summarizes the design, production and test phases of the ion source and LEBT line components

    Elevated Pontine and Putamenal GABA Levels in Mild-Moderate Parkinson Disease Detected by 7 Tesla Proton MRS

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    Background: Parkinson disease (PD) is characterized by the degeneration of nigrostriatal dopaminergic neurons. However, postmortem evidence indicates that the pathology of lower brainstem regions, such as the pons and medulla, precedes nigral involvement. Consistently, pontomedullary damage was implicated by structural and PET imaging in early PD. Neurochemical correlates of this early pathological involvement in PD are unknown. Methodology/Principal Finding: To map biochemical alterations in the brains of individuals with mild-moderate PD we quantified neurochemical profiles of the pons, putamen and substantia nigra by 7 tesla (T) proton magnetic resonance spectroscopy. Thirteen individuals with idiopathic PD (Hoehn & Yahr stage 2) and 12 age- and gender-matched healthy volunteers participated in the study. c-Aminobutyric acid (GABA) concentrations in the pons and putamen were significantly higher in patients (N = 11, off medications) than controls (N = 11, p,0.001 for pons and p,0.05 for putamen). The GABA elevation was more pronounced in the pons (64%) than in the putamen (32%). No other neurochemical differences were observed between patients and controls. Conclusion/Significance: The GABA elevation in the putamen is consistent with prior postmortem findings in patients with PD, as well as with in vivo observations in a rodent model of PD, while the GABA finding in the pons is novel. The more significant GABA elevation in the pons relative to the putamen is consistent with earlier pathological involvement of th

    Simulating MADMAX in 3D: Requirements for dielectric axion haloscopes

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    We present 3D calculations for dielectric haloscopes such as the currently envisioned MADMAX experiment. For ideal systems with perfectly flat, parallel and isotropic dielectric disks of finite diameter, we find that a geometrical form factor reduces the emitted power by up to 30 % compared to earlier 1D calculations. We derive the emitted beam shape, which is important for antenna design. We show that realistic dark matter axion velocities of 10-3 c and inhomogeneities of the external magnetic field at the scale of 10 % have negligible impact on the sensitivity of MADMAX. We investigate design requirements for which the emitted power changes by less than 20 % for a benchmark boost factor with a bandwidth of 50 MHz at 22 GHz, corresponding to an axion mass of 90 µ eV. We find that the maximum allowed disk tilt is 100 µ m divided by the disk diameter, the required disk planarity is 20 µ m (min-to-max) or better, and the maximum allowed surface roughness is 100 µ m (min-to-max). We show how using tiled dielectric disks glued together from multiple smaller patches can affect the beam shape and antenna coupling. © 2021 The Author(s)
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