153 research outputs found
Identifying the magnetotail lobes with Cluster magnetometer data
We describe a novel method for identifying times when a spacecraft is in Earthâs magnetotail lobes solely using magnetometer data. We propose that lobe intervals can be well identified as times when the magnetic field is strong and relatively invariant, defined using thresholds in the magnitude of BX and the standard deviation Ï of the magnetic field magnitude. Using data from the Cluster spacecraft at downtail distances greater than 8 RE during 2001â2009, we find that thresholds of 30 nT and 3.5 nT, respectively, optimize agreement with a previous, independently derived lobe identification method that used both magnetic and plasma data over the same interval. Specifically, our method has a moderately high accuracy (66%) and a low probability of false detection (11%) in comparison to the other method. Furthermore, our method identifies the lobe on many other occasions when the previous method was unable to make any identification and yields longer continuous intervals in the lobe than the previous method, with intervals at the 90th percentile being triple the length. Our method also allows for analyses of the lobes outside the time span of the previous method
Observed Loss of Polar Mesospheric Ozone Following Substorm-Driven Electron Precipitation
Several drivers cause precipitation of energetic electrons into the atmosphere. While some of these drivers are accounted for in proxies of energetic electron precipitation (EEP) used in atmosphere and climate models, it is unclear to what extent the proxies capture substormâinduced EEP. The energies of these electrons allow them to reach altitudes between 55 and 95 km. EEPâdriven enhanced ionization is known to result in production of HOx and NOx, which catalytically destroy ozone. Substormâdriven ozone loss has previously been simulated, but has not been observed before. We use mesospheric ozone observations from the Microwave Limb Sounder and Global Ozone Monitoring by Occultation of Stars instruments, to investigate the loss of ozone during substorms. Following substorm onset, we find reductions of polar mesospheric (âŒ76 km) ozone by up to 21% on average. This is the first observational evidence demonstrating the importance of substorms on the ozone balance within the polar atmosphere
Annex 3 : report barrier seminar
Annex to Final Technical Repor
Clinical and pharmacological profile of benznidazole for treatment of Chagas disease
Introduction: Chagas disease (CD) is one of the most neglected public health problems in the Americas, where <1% of the estimated 6 million people with the infection have been diagnosed and treated. The goal of treatment is to eliminate the parasite, decrease the probability of cardiomyopathy and other complications during the chronic stage of infection, and interrupt the cycle of disease transmission by preventing congenital infection. Currently, only benznidazole (BZN) and nifurtimox are recognized by the World Health Organization as effective drugs for treatment of CD. In this paper, we provide an overview of the clinical pharmacology of BZN. Areas covered: This review covers the historical background, chemistry, mechanism of action, pharmacokinetics, preclinical research, resistance, clinical research, toxicology, adverse effects, and current regulatory status of BZN. Expert commentary: Ongoing investigations aim to optimize BZN therapy by adjusting the current standard regimen or by combining BZN with new chemical entities. These studies are assessing alternatives that improve safety while maintaining or increasing the efficacy of BZN. Timely diagnosis and antitrypanosomal treatment are critical components of programs to eliminate CD as a public health problem, and can dramatically reduce the heavy burden of morbidity and mortality caused by the disease.Fil: MĂŒller Kratz, Jadel. No especifĂca;Fil: GarcĂa Bournissen, Facundo. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo GutiĂ©rrez"; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Forsyth, Colin J.. No especifĂca;Fil: Sosa-Estani, Sergio Alejandro. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Centro de Investigaciones en EpidemiologĂa y Salud PĂșblica. Instituto de Efectividad ClĂnica y Sanitaria. Centro de Investigaciones en EpidemiologĂa y Salud PĂșblica; Argentin
The influence of substorms on extreme rates of change of the surface horizontal magnetic field in the United Kingdom
We investigate how statistical properties of the rate of change R of the surface horizontal magnetic field in the United Kingdom differ during substorm expansion and recovery phases compared with other times. R is calculated from 1âmin magnetic field data from three INTERMAGNET observatoriesâLerwick, Eskdalemuir, and Hartland and between 1996 and 2014ânearly two solar cycles. Substorm expansion and recovery phases are identified from the SuperMAG Lower index using the Substorm Onsets and Phases from Indices of the Electrojet method. The probability distribution of R is decomposed into categories of whether during substorm expansion and recovery phases, in enhanced convection intervals, or at other times. From this, we find that 54â56% of all extreme R values (defined as above the 99.97th percentile) occur during substorm expansion or recovery phases. By similarly decomposing the magnetic local time variation of the occurrence of large R values (>99th percentile), we deduce that 21â25% of large R during substorm expansion and recovery phases are attributable to the Disturbance Polar (DP)1 magnetic perturbation caused by the substorm current wedge. This corresponds to 10â14% of all large R in the entire data set. These results, together with asymptotic trends in occurrence probabilities, may indicate the twoâcell DP2 magnetic perturbation caused by magnetospheric convection as the dominant source of hazardous R > 600 nT/min that is potentially damaging to the U.K. National Grid. Thus, further research is needed to understand and model DP2, its mesoscale turbulent structure, and substorm feedbacks in order that GIC impact on the National Grid may be better understood and predicted
The multidimensional comprehension of chagas disease. Contributions, approaches, challenges and opportunities from and beyond the information, education and communication field
Chagas is a complex, multidimensional phenomenon in which political, economic, environmental, biomedical, epidemiological, psychological, and sociocultural factors intersect. Nonetheless, the hegemonic conceptualisation has long envisioned Chagas as primarily a biomedical question, while ignoring or downplaying the other dimensions, and this limited view has reinforced the diseaseâs long neglect. Integrating the multiple dimensions of the problem into a coherent approach adapted to field realities and needs represents an immense challenge, but the payoff is more effective and sustainable experiences, with higher social awareness, increased case detection and follow-up, improved adherence to care, and integrated participation of various actors from multiple action levels. Information, Education, and Communication (IEC) initiatives have great potential for impact in the implementation of multidimensional programs of prevention and control successfully customised to the diverse and complex contexts where Chagas disease persists.Fil: Sanmartino, Mariana. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - La Plata. Instituto de FĂsica de LĂquidos y Sistemas BiolĂłgicos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de FĂsica de LĂquidos y Sistemas BiolĂłgicos; ArgentinaFil: Forsyth, Colin J.. No especifĂca;Fil: Avaria, Andrea. Universidad AutĂłnoma de Chile; ChileFil: Velarde Rodriguez, Mar. Universidad de Basilea; SuizaFil: GĂłmez I Prat, Jordi. 6hospital Universitari Vall Dhebron; EspañaFil: Albajar Viñas, Pedro. OrganizaciĂłn Mundial de la Salud; Suiz
Recommended from our members
Statistical characterisation of the growth and spatial scales of the substorm onset arc
We present the first multi-event study of the spatial and temporal structuring of the aurora to provide statistical evidence of the near-Earth plasma instability which causes the substorm onset arc. Using data from ground-based auroral imagers, we study repeatable signatures of along-arc auroral beads, which are thought to represent the ionospheric projection of magnetospheric instability in the near-Earth plasma sheet. We show that the growth and spatial scales of these wave-like fluctuations are similar across multiple events, indicating that each sudden auroral brightening has a common explanation. We find statistically that growth rates for auroral beads peak at low wavenumber with the most unstable spatial scales mapping to an azimuthal wavelength λâ1700 â 2500 km in the equatorial magnetosphere at around 9-12 RE. We compare growth rates and spatial scales with a range of theoretical predictions of magnetotail instabilities, including the cross-field current instability and the shear-flow ballooning instability. We conclude that, although the cross-field current instability can generate similar magnitude of growth rates, the range of unstable wavenumbers indicates that the shear-flow ballooning instability is the most likely explanation for our observations
Recommended from our members
How Do UltraâLow Frequency Waves Access the Inner Magnetosphere During Geomagnetic Storms?
Waveâparticle interactions play a key role in radiation belt dynamics. Traditionally, ultraâlow frequency (ULF) waveâparticle interaction is parameterized statistically by a small number of controlling factors for given solar wind driving conditions or geomagnetic activity levels. Here we investigate solar wind driving of ULF wave power and the role of the magnetosphere in screening that power from penetrating deep into the inner magnetosphere. We demonstrate that during enhanced ring current intensity, the AlfvĂ©n continuum plummets, allowing lower frequency waves to penetrate deeper into the magnetosphere than during quiet periods. With this penetration, ULF wave power is able to accumulate closer to the Earth than characterized by statistical models. During periods of enhanced solar wind driving such as coronal mass ejection driven storms, where ring current intensities maximize, the observed penetration provides a simple physicsâbased reason for why storm time ULF wave power is different compared to nonstorm time waves
Awareness of Chagas disease and socioeconomic characteristics of Bolivian immigrants living in Sao Paulo, Brazil
In this study which is part of a research project on Chagas disease (CD) among Bolivian immigrants in Sao Paulo, we describe socioeconomic characteristics, knowledge of CD and implications for acess to health care. We applied a structured questionnaire to a sample of 472 Bolivian adults (> 18 years) living in Sao Paulo and enrolled at the Barra Funda School Health Center. Participantsâ median age was 28.5 years, 75.0% were from the Bolivian department of La Paz, and >90% worked in the garment industry. Respondents had lived in Sao Paulo for a median of 5.8 years. Only 169 (35.8%) were familiar with CD, while roughly half (50.4%) had lived in natural materials houses in Bolivia, 225 (47.7%) indicated familiarity with the vector, 23.9% had seen the vector in their homes in Bolivia, and 6.4% reported having been bitten by a triatomine bug. Factors associated with awareness of CD were analyzed by chi square tests, and those with p values <0.25 were included in a multivariable logistic regression model. In the multivariable logistic regression analysis, having a relative with CD (OR=4.3, 95% CI=1.5-12.0), having lived in a house with mud or wood walls (OR=0.4, 95% CI=0.2-0.8), and having heard of the triatomine bug, or vinchuca, (OR=10.0, 95% CI=5.1-19.5) were significantly associated with awareness of CD. This study shows a low familiarity with CD among Bolivian migrants living in Sao Paulo, Brazil. Raising awareness of the disease through specific communication strategies should be an essential component of public health programs to reduce the burden of CD in this and other vulnerable populations
- âŠ