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Much can be learned from terrestrial planets that appear to have had the potential to be habitable, but failed to realize that potential. Mars shows evidence of a once hospitable surface environment. The reasons for its current state, and in particular its thin atmosphere and dry surface, are of great interest for what they can tell us about habitable zone planet outcomes. A main goal of the MAVEN mission is to observe Mars’ atmosphere responses to solar and space weather influences, and in particular atmosphere escape related to space weather ‘storms’ caused by interplanetary coronal mass ejections (ICMEs). Numerical experiments with a data-validated MHD model suggest how the effects of an observed moderately strong ICME compare to what happens during a more extreme event. The results suggest the kinds of solar and space weather conditions that can have evolutionary importance at a planet like Mars.
The Total Solar Irradiance (TSI), which is the total radiation arriving at Earth's atmosphere from the Sun, is one of the most important forcing of the Earths climate. Measurements of the TSI have been made employing instruments on board several space-based platforms during the last four solar cycles. However, combining these measurements is still challenging due to the degradation of the sensor elements and the long-term stability of the electronics. Here we describe the preliminary efforts to design an absolute radiometer based on the principle of electrical substitution that is under development at Brazilian's National Institute for Space Research (INPE).
Recent observations of the magnetic field in pre-main sequence stars suggest that the magnetic field topology changes as a function of age. The presence of a tachocline could be an important factor in the development of magnetic field with higher multipolar modes. In this work we performed MHD simulations using the EULAG-MHD code to study the magnetic field generation and evolution in models that mimic stars at two evolutionary stages. The stratification for both stellar phases was computed by fitting stellar structure profiles obtained with the ATON stellar evolution code. The first stage is at 1.1Myr, when the star is completely convective. The second stage is at 14Myrs, when the star is partly convective, with a radiative core developed up to 30% of the stellar radius. In this proceedings we present a preliminary analysis of the resulting mean-flows and magnetic field. The mean-flow analysis shown that the star rotate almost rigidly on the fully convective phase, whereas at the partially convective phase there is differential rotation with conical contours of iso-rotation. As for the mean magnetic field both simulations show similarities with respect to the field evolution. However, the topology of the magnetic field is different.
It is well known that the cosmic ray intensity observed at the Earth's surface presents an 11 and 22-yr variations associated with the solar activity cycle. However, the observation and analysis of this modulation through ground muon detectors datahave been difficult due to the temperature effect. Furthermore, instrumental changes or temporary problems may difficult the analysis of these variations. In this work, we analyze the cosmic ray intensity observed since October 1970 until December 2012 by the Nagoya muon detector. We show the results obtained after analyzing all discontinuities and gaps present in this data and removing changes not related to natural phenomena. We also show the results found using the mass weighted method for eliminate the influence of atmospheric temperature changes on muon intensity observed at ground. As a preliminary result of our analyses, we show the solar cycle modulation in the muon intensity observed for more than 40 years.
In this work, we investigate the stellar magnetic activity in the theoretical point of view, through the use of stellar structure and evolution models. We present theoretical values of convective turnover times and Rossby numbers for low-mass stars, calculated with the ATON stellar structure and evolution code. We concentrate our analysis on fully convective and partially convective stars motivated by recent observations of X-ray emission of slowly rotating fully convective stars, which suggest that the presence of a tachocline is not a central key for magnetic fields generation. We investigate the behavior of the convective turnover time evolution, as well as its radial profile inside the star. A discussion about the location where the convective turnover time is calculated in the stellar interior is also addressed. Our theoretical results are compared to observational data from low-mass stars.
Microwave-assisted oxidation of trichloroethane (TCE) performed at 500-580°C has been found to be significantly more efficient than conventional oxidation methods. Experiments were conducted using a 6 kW, 2.45 GHz power supply and a 6 inch bed of silicon carbide granules in a 1 inch diameter quartz reactor tube which in turn was placed in a microwave cavity. After heating the reactor to a given temperature a TCE-air stream was passed through the silicon carbide bed. TCE was almost completely detoxified (98-99%) in a single pass through the silicon carbide bed at 500-580°C. The oxidation products are HC1, CO2 and CO. By comparison the corresponding single-pass detoxification using conventional thermal methods results in only partial conversion. The principal products being dichloroethylene (C2H2C12) and HCl.
Bovine herpes virus 1 (BHV-1) is primarily associated with clinical syndromes such as rhinotracheitis, pustular vulvovaginitis and balanoposthitis, abortion, infertility, conjunctivitis and encephalitis in bovine species. The main sources of infection are the nasal exudates and the respiratory droplets, genital secretions, semen, fetal fluids and tissues. The BHV-1 virus can become latent following a primary infection with a field isolate or vaccination with an attenuated strain. The viral genomic DNA has been demonstrated in the sensory ganglia of the trigeminal nerve in infectious bovine rhinotracheitis (IBR) and in sacral spinal ganglia in pustular vulvovaginitis and balanoposthitis cases. BHV-1 infections can be diagnosed by detection of virus or virus components and antibody by serological tests or by detection of genomic DNA by polymerase chain reaction (PCR), nucleic acid hybridization and sequencing. Inactivated vaccines and modified live virus vaccines are used for prevention of BHV-1 infections in cattle; subunit vaccines and marker vaccines are under investigation.
Analysis of eye movements is essential for investigating vestibular disturbances. Video-oculography, although expensive, is a valuable and sensitive tool that allows accurate estimation of eye movements. We describe a simple and inexpensive method of recording as well as analysing eye movements using a commercially available miniature digital video surveillance camera and an MP4 digital media recorder.
In this study, we have analysed the epidemiological significance of the concurrent infections caused by Vibrio cholerae and intestinal parasites among different age groups of hospitalized diarrhoeal patients in Kolkata. A total of 3556 stool samples collected during 1996–2004 were screened for vibrios and parasites. The seasonality of V. cholerae and parasitic infections were studied in detail. The detection rates for Ascaris lumbricoides and Giardia lamblia infection were more than for the hookworm, Trichuris trichiura and Entamoeba histolytica. V. cholerae O1 was identified as the predominant serogroup among diarrhoeal patients. The highest rates for V. cholerae infection were in the 2–5 years age group and combined infection of V. cholerae and parasites was recorded among children aged between 2 and 10 years.
Visual reinforcement audiometry (VRA) is an important behavioural test of hearing in young children. The use of insert earphones during VRA provides a reliable method of obtaining ear- and frequency-specific data. Two testers are usually required for this procedure. The first tester operates the audiometer and other controls while the second tester distracts the child with various toys. The paper describes a technique of providing a visual cue to the second tester when a sound stimulus is introduced through the insert earphones.
While searching for Escherichia coli O157 in the aquatic environment of Calcutta using an immunodetection procedure, we fortuitously detected five strains of Citrobacter braakii, which cross-reacted with the commercially available O157 polyvalent antiserum. The five C. braakii isolates gave positive results when a sensitive dot-ELISA was performed with E. coli O157 monoclonal antibody. Further, the O157 monoclonal antibody recognized the bands of proteinase K treated whole cells of lipopolysaccharide of all the C. braakii isolates. Apart from weak reactions with two or three of the DNA probes, all the C. braakii strains did not hybridize with the other probes spanning the minimum region required for O157 O-antigen biosynthesis. These strains did not possess any of the virulence genes that are commonly found in the Shiga toxin-producing E. coli (STEC) specially the serotype O157[ratio ]H7. Therefore, it appears that the serological cross-reaction between C. braakii and E. coli O157 antiserum is based on structural mimicry between the O-polysaccharide of C. braakii and E. coli O157.
The war in Kosovo in 1999 resulted in the displacement of up to 1.5 million persons from their homes. On the subsequent return of the refugees and internally displaced persons, one of the major challenges facing the local population and the international community, was the rehabilitation of Kosovo's public health infrastructure, which had sustained enormous damage as a result of the fighting. Of particular importance was the need to develop a system of epidemic prevention and preparedness. But no single agency had the resources or capacity to implement such a program. Therefore, a unique six-point model was developed as a collaboration between the Kosovo Institute of Public Health, the World Health Organization, and an international, nongovernmental organization. Important components of the program included a major Kosovo-wide baseline health survey, the development of a provincewide public health surveillance system, rehabilitation of microbiology laboratories, and the development of a local capacity for epidemic response. While all program objectives were met, important lessons were learned concerning the planning, design, and implementation of such a project. This program represents a model that potentially could be replicated in other post-conflict or development settings.
The ultraviolet interstellar extinction curve from 2740Å to 1350Å has been obtained using data from the S2/68 satellite experiment. The extinction increases into the ultraviolet and shows a pronounced peak at 2200Å. This is interpreted as a general scattering continuum with a strong absorption feature superposed on it at 2200Å. The profile of the feature appears to be symmetrical and has a half-width of 360Å. There is a strong correlation between the strength of the feature and the scattering part of the curve in both the ultraviolet and the visible. On a broad scale the shape of the extinction curve is constant showing no variation with distance from the sun, direction around the galaxy, and height above the galactic plane.
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