Diffusion of charged particles in tokamak‐like stochastic magnetic and electric fields

In this paper the diffusion of guiding centers induced by stochastic magnetic and electric field fluctuations, with both time and space dependence, is analyzed for the case of tokamak plasmas. General experimental results on tokamak fluctuations are used to derive guiding‐center equations that properly describe the particle motion. These equations assume uniform average magnetic and electric fields with random stationary Gaussian fluctuations that constitute a homogeneous and cylindrically symmetric turbulence. By applying Novikov’s theorem, a Fokker–Planck equation for the probability distribution function is derived and an expression for the guiding‐center diffusion coefficient is obtained. This coefficient not only contains the standard terms due to the stochastic wandering of the magnetic lines and the stochastic electric drift, but also new terms due to the stochastic curvature and ∇B drifts. The form of these terms is shown explicitly in terms of the correlation functions of the fields.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70770/2/PFBPEI-4-12-3935-1.pd

Nitric oxide modulation of glutamatergic, baroreflex, and cardiopulmonary transmission in the nucleus of the solitary tract

The neuromodulatory effect of NO on glutamatergic transmission has been studied in several brain areas. Our previous single-cell studies suggested that NO facilitates glutamatergic transmission in the nucleus of the solitary tract (NTS). in this study, we examined the effect of the nitric oxide synthase (NOS) inhibitor NG-nitro-L-arginine methyl ester (L-NAME) on glutamatergic and reflex transmission in the NTS. We measured mean arterial pressure (MAP), heart rate (HR), and renal sympathetic nerve activity (RSNA) from Inactin-anesthetized Sprague-Dawley rats. Bilateral microinjections of L-NAME (10 nmol/100 nl) into the NTS did not cause significant changes in basal MAP, HR, or RSNA. Unilateral microinjection of (RS)-alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA, 1 pmol/100 nl) into the NTS decreased MAP and RSNA. Fifteen minutes after L-NAME microinjections, AMPA-evoked cardiovascular changes were significantly reduced. N-methyl-D-aspartate (NMDA, 0.5 pmol/100 nl) microinjection into the NTS decreased MAP, HR, and RSNA. NMDA-evoked falls in MAP, HR, and RSNA were significantly reduced 30 min after L-NAME. To examine baroreceptor and cardiopulmonary reflex function, L-NAME was microinjected at multiple sites within the rostro-caudal extent of the NTS. Baroreflex function was tested with phenylephrine (PE, 25 mug iv) before and after L-NAME. Five minutes after L-NAME the decrease in RSNA caused by PE was significantly reduced. To examine cardiopulmonary reflex function, phenylbiguanide (PBG, 8 mug/kg) was injected into the right atrium. PBG-evoked hypotension, bradycardia, and RSNA reduction were significantly attenuated 5 min after L-NAME. Our results indicate that inhibition of NOS within the NTS attenuates baro- and cardiopulmonary reflexes, suggesting that NO plays a physiologically significant neuromodulatory role in cardiovascular regulation.Univ Texas, Hlth Sci Ctr, Dept Pharmacol, San Antonio, TX 78229 USAUniversidade Federal de São Paulo, Escola Paulista Med, Dept Physiol, São Paulo, BrazilUniversidade Federal de São Paulo, Escola Paulista Med, Dept Physiol, São Paulo, BrazilWeb of Scienc

Decynium-22 enhances SSRI-induced antidepressant-like effects in mice: uncovering novel targets to treat depression

Mood disorders cause much suffering and lost productivity worldwide, compounded by the fact that many patients are not effectively treated by currently available medications. The most commonly prescribed antidepressant drugs are the selective serotonin (5-HT) reuptake inhibitors (SSRIs), which act by blocking the high-affinity 5-HT transporter (SERT). The increase in extracellular 5-HT produced by SSRIs is thought to be critical to initiate downstream events needed for therapeutic effects. A potential explanation for their limited therapeutic efficacy is the recently characterized presence of low-affinity, high-capacity transporters for 5-HT in brain [i.e., organic cation transporters (OCTs) and plasma membrane monoamine transporter], which may limit the ability of SSRIs to increase extracellular 5-HT. Decynium-22 (D-22) is a blocker of these transporters, and using this compound we uncovered a significant role for OCTs in 5-HT uptake in mice genetically modified to have reduced or no SERT expression (Baganz et al., 2008). This raised the possibility that pharmacological inactivation of D-22-sensitive transporters might enhance the neurochemical and behavioral effects of SSRIs. Here we show that in wild-type mice D-22 enhances the effects of the SSRI fluvoxamine to inhibit 5-HT clearance and to produce antidepressant-like activity. This antidepressant-like activity of D-22 was attenuated in OCT3 KO mice, whereas the effect of D-22 to inhibit 5-HT clearance in the CA3 region of hippocampus persisted. Our findings point to OCT3, as well as other D-22-sensitive transporters, as novel targets for new antidepressant drugs with improved therapeutic potential.Rebecca E. Horton, Deana M. Apple, W. Anthony Owens, Nicole L. Baganz, Sonia Cano, Nathan C. Mitchell, Melissa Vitela, Georgianna G. Gould, Wouter Koek and Lynette C. Daw

Fresnel polarisation of infra-red radiation by elemental bismuth

We revisit the classical problem of electromagnetic wave refraction from a lossless dielectric to a lossy conductor, where both media are considered to be non-magnetic, linear, isotropic and homogeneous. We derive the Fresnel coefficients of the system and the Poynting vectors at the interface, in order to compute the reflectance and transmittance of the system. We use a particular parametrisation of the referred Fresnel coefficients so as to make a connection with the ones obtained for refraction by an interface between two lossless media. This analysis allows the discussion of an actual application, namely the Fresnel polarisation of infra-red radiation by elemental bismuth, based on the concept of pseudo Brewster’s angle.We acknowledge helpful discussions with M. Vasilevskiy, P. Alpuim, J. Caridad and B. Figueiredo. The authors thank the European Structural and Investment Funds in the FEDER component, through the Operational Programme for Competitiveness and Internationalization (COMPETE 2020) [under the Project GNESIS -Graphenest's New Engineered System and its Implementation Solutions; Funding Reference: POCI-01-0247-FEDER-033566], European Regional Development Fund. This work was also supported by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding UID/FIS/04650/2019

Optimal laser heating of plasmas with constant density

The laser heating of a plasma with constant density is analyzed using optimal control theory. Heating strategies that minimize the total energy spent, the heating time, or a linear combination of the two, for several values of weighting coefficients, are obtained by determining the optimal laser intensity associated with each point of the phase plane. A numerical example is used to illustrate the application of the theory. In this particular example, savings in the energy spent up to 75%, compared with the energy required using a constant laser pulse, are obtained when minimum energy trajectories are implemented. Strategies that minimize the heating time, however, did not yield a significant reduction in the heating time. Numerical results may depend strongly on the initial state of the system as well as on the final ion temperature of the plasma.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45228/1/10957_2004_Article_BF00938468.pd

Saberes digitales: una aproximación desde las voces de los estudiantes

The second decade of the new century is about to end. In educational matters, it could be affirmed that many learning has left us the insertion of technologies in the classroom in these years, at all levels schoolchildren without exception. However, it could also be ensured that challenges in the short term arising from the current revolution social and technological, which on many occasions has left us without Enough spaces to reflect on its progress and implications It is interesting and challenging how the training processes in these last 20 years, when technologies of information and communications (ICT) have evolved step by step accelerated. Interesting, on the one hand, since one of the most important contributions important of the ICT is to act as large portals with access to the world, which both students, teachers and researchers open daily to understand the progress of their areas of knowledge and use tools that allow establishing better connectivity networks for the learning. Challenging, on the other hand, due to changes in paradigm that is being built around what has been understood for years regarding what the training process requires in terms of planning, didactic strategies, use of learning resources and the evaluation, to mention the main

Listeria monocytogenes in Milk Products

peer-reviewedMilk and milk products are frequently identified as vectors for transmission of Listeria monocytogenes. Milk can be contaminated at farm level either by indirect external contamination from the farm environment or less frequently by direct contamination of the milk from infection in the animal. Pasteurisation of milk will kill L. monocytogenes, but post-pasteurisation contamination, consumption of unpasteurised milk and manufacture of unpasteurised milk products can lead to milk being the cause of outbreaks of listeriosis. Therefore, there is a concern that L. monocytogenes in milk could lead to a public health risk. To protect against this risk, there is a need for awareness surrounding the issues, hygienic practices to reduce the risk and adequate sampling and analysis to verify that the risk is controlled. This review will highlight the issues surrounding L. monocytogenes in milk and milk products, including possible control measures. It will therefore create awareness about L. monocytogenes, contributing to protection of public health

Prevalencia de Salmonella y Staphylococcus aureus en chorizo y longaniza

Epidemiological research in developed and developing countries, had found meat products as the principal cause for foodbourne diseases. In addition, Salmonella and Staphyococcus aureus are well known pathogens for their mayor impact in public health. The objective for the present study consisted on determinate the sanitary quality from chorizo and longaniza samples from several butcheries in Guadalajara, Jalisco, Mexico. Samples of chorizo (50) and longaniza (50) were obtained from different points in Guadalajara metropolis. Presence of Salmonella and recounts for S. aureus were tested in 25 g samples. Procedure was followed according Mexican NOM 145-SSA1-1995 methods. In chorizo, 18 samples were positive to Salmonella. The count of S. aureus showed a mean of 24,600 UFC/g. On the other hand, 24 samples of longaniza were positive to Salmonella spp. In this case, the mean of S. aureus was 7,800 UFC/g. The serotypes of Salmonella spp were: Derby (30%), Adelaile (17%), Azteca (15%), Infantis (15%), Muenster(10%) y Anatum (13 %). The high positivity of Salmonella spp. and S. aureus is a potential hazard to consumers.Reportes epidemiológicos ubican los productos cárnicos como una causa importante de enfermedades transmitidas por alimentos. Salmonella y Staphylococcus aureus son patógenos identificados como los principales microorganismos de impacto para la salud pública. En este trabajo se determino la prevalencia de Salmonella spp y S. aureus en chorizo y longaniza de carnicerías de la ciudad de Guadalajara, Jalisco, México. Se obtuvieron 50 muestras de chorizo y 50 de longaniza a partir de carnicerías ubicadas en diferentes puntos de la zona metropolitana de Guadalajara. Se investigó la presencia de Salmonella spp., y se cuantificó S. aureus en 25 g de muestra El análisis se hizo como lo indica la metodología descrita en la NOM 145- SSA1-1995. De las 50 muestras de chorizo 18 resultaron positivas a Salmonella, mientras que el recuento de S. aureus presento una media de 24,600 UFC/g. En relación a las muestras de longaniza, 24 fueron positivas a Salmonella spp y S. aureus mostró una media de 7,800 UFC/g. Los serotipos de Salmonella spp encontrados fueron: Derby (30%), Adelaile (17%), Azteca (15%), Infantis (15%), Muenster (10%) y Anatum (13 %). La alta positividad de Salmonella spp. y S. aureus en chorizo y longaniza constituye un peligro potencial para los consumidores

Prodiag--a hybrid artificial intelligence based reactor diagnostic system for process faults

Commonwealth Research Corporation (CRC) and Argonne National Laboratory (ANL) are collaborating on a DOE-sponsored Cooperative Research and Development Agreement (CRADA), project to perform feasibility studies on a novel approach to Artificial Intelligence (Al) based diagnostics for component faults in nuclear power plants. Investigations are being performed in the construction of a first-principles physics-based plant level process diagnostic expert system (ES) and the identification of component-level fault patterns through operating component characteristics using artificial neural networks (ANNs). The purpose of the proof-of-concept project is to develop a computer-based system using this Al approach to assist process plant operators during off-normal plant conditions. The proposed computer-based system will use thermal hydraulic (T-H) signals complemented by other non-T-H signals available in the data stream to provide the process operator with the component which most likely caused the observed process disturbance.To demonstrate the scale-up feasibility of the proposed diagnostic system it is being developed for use with the Chemical Volume Control System (CVCS) of a nuclear power plant. A full-scope operator training simulator representing the Commonwealth Edison Braidwood nuclear power plant is being used both as the source of development data and as the means to evaluate the advantages of the proposed diagnostic system. This is an ongoing multi-year project and this paper presents the results to date of the CRADA phase