Seroprevalencia de la toxoplasmosis humana en Córdoba

Se realiza un estudio sobre seroprevalencia de la toxoplasmosis humana en Córdoba, mediante inmunofluorescencia indirecta y hemaglutinación indirecta. La muestra encuestada se compone de 443 sueros, 356 personas supuestamente sanas (estudiantes fundamentalmente) y 87, consideradas de “alto riesgo” (enfermos del Hospital “Reina Sofía”). La positividad obtenida para el total de la muestra ha sido del 43,79 % con IFI y 53,50 % para HAI. Con respecto al sexo, la prevalencia es superior en mujeres con un 54,36 % y 70,47 % con IFI y HAI, respectivamente, en varones el 38,43 % y 44,90 % para las mismas pruebas. En relación con la procedencia de la muestra, 31,lB % con IFI y 43,25 % para HAI sobre la población normal, en la de “alto riesgo” para ambas pruebas el 95,40 %. Entre ambas pruebas hay diferencias significativas a títulos bajos, no así en diluciones altas, Concluimos que la toxoplasmosis humana está presente y difundida en las poblaciones estudiadasA seroprevalency study of human toxoplasmosis was carried out in Córdoba, using indirect immunofluorescence and indirect haemoglutination. The sample of people interviewed was made up of 443 serums, 356 supposedly healthy people (mainly students) and 87, considered “high risk” (pafients from the “Reina Sofia” Hospital). The positiveness obtained for the total of the sample was 43,79 % with IFI and 53,59 % for HAI. As regards sex of the person tested, prevalence is higher in women, with 54,36 % and 70,47 % with IFI and HAI respectively, in men the scores were 38,43 % and 44,90 % for the same tests. As far as the origin of the sample was concerned, there were 31,lB % with IFI and 43,25 % for HAI of the nornal population, in the “high risk” sample, for both tests it was 9540 %. With both tests there are significative differences in low amounts, but not in high dilutions. We conclude that human toxoplasmosis is present and widespread in the studied population

COVID-19 attributed mortality and ambient temperature: a global ecological study using a two-stage regression model

A negative correlation between ambient temperature and COVID-19 mortality has been observed. However, the World Meteorological Organization (WMO) has reinforced the importance of government interventions and warned countries against relaxing control measures due to warmer temperatures. Further understanding of this relationship is needed to help plan vaccination campaigns opportunely. Using a two-stage regression model, we conducted cross-sectional and longitudinal analyses to evaluate the association between monthly ambient temperature lagged by one month with the COVID-19 number of deaths and the probability of high-level of COVID-19 mortality in 150 countries during time t = 60, 90, and 120 days since the onset. First, we computed a log-linear regression to predict the pre-COVID-19 respiratory disease mortality to homogenize the baseline disease burden within countries. Second, we employed negative binomial and logistic regressions to analyze the linkage between the ambient temperature and our outcomes, adjusting by pre-COVID-19 respiratory disease mortality rate, among other factors. The increase of one Celsius degree in ambient temperature decreases the incidence of COVID-19 deaths (IRR = 0.93; SE: 0.026, p-value<0.001) and the probability of high-level COVID-19 mortality (OR = 0.96; SE: 0.019; p-value<0.001) over time. High-income countries from the northern hemisphere had lower temperatures and were most affected by pre-COVID respiratory disease mortality and COVID-19 mortality. This study provides a global perspective corroborating the negative association between COVID-19 mortality and ambient temperature. Our longitudinal findings support the statement made by the WMO. Effective, opportune, and sustained reaction from countries can help capitalize on higher temperatures’ protective role including the timely rollout of vaccination campaigns

Solar UV network in Antarctica

Póster elaborado para la 25th General Assembly of the European Geophysical Society celebrada en Niza, Francia del 25 al 29 de abril de 200

Thermal Diffusion of a Two Layer System

In this paper thermal conductivity and thermal diffusivity of a two layer system is examined from the theoretical point of view. We use the one dimensional heat diffusion equation with the appropriate solution in each layer and boundary conditions at the interfaces to calculate the heat transport in this bounded system. We also consider the heat flux at the surface of the samle as boundary condition instead of using a fixed tempertaure. From this, we obtain an expression for the efective thermal diffusivity of the composite sample in terms of the thermal diffusivity of its constituent materials whithout any approximations.Comment: 16 pages, 1 figure, RevTeX v. 3.0 macro packag

Estimación de la emigración del camarón café Farfantepenaeus aztecus a través de la boca del Mezquital, Tamaulipas, México

Variations of juvenile abundance of brown shrimp (Farfantepenaeus aztecus) during its main period of migration in Mezquital Inlet, Tamaulipas are presented. Sampling was carried out from 2003 to 2007 between May and July and consisted in the use of an experimental net during the nocturnal period and ebb tide, three days before and after full and new moon. The information was complemented with abundance data of trawl research cruises carried out off the coast of Tamaulipas between May and July from 2003 to 2007. The results showed that the higher values of emigration (kg/night) occurred during the moon period in late May or early June, independently of the lunar phase. The higher values of emigration toward the sea are directly related to the increase in the abundance in the coastal and marine zones. These results are of great importance because the significance of the months of May and June was demonstrated, and can be useful to set the limits of the closed season of the inshore and offshore shrimp fishery.Se presentan la variación en abundancia de juveniles de camarón café (Farfantepeneaeus aztecus) durante su principal periodo de emigración hacia el mar, en la boca del Mezquital, Tamaulipas. Los muestreos fueron realizados entre mayo y julio del 2003 al 2007 y consistieron en el uso de una red de corriente experimental durante el periodo nocturno y durante periodos de bajamar, en los tres días anteriores y posteriores a la presencia de luna nueva y llena. La información fue complementada con datos de abundancia obtenidos con arrastres en cruceros de investigación realizados en la costa de Tamaulipas durante mayo a julio del 2003 al 2007. Los resultados muestran que los máximos valores de emigración (kg/noche) se presentan durante el periodo lunar a finales de mayo y/o principios de junio, indistintamente de la fase lunar y se relacionaron directamente con aumentos en los valores de abundancia en la zona costera y marina. Estos resultados son de gran importancia porque demuestran que mayo y junio son meses críticos para esta especie, y sirven como base para la definición de los periodos de veda para la pesca de camarón, tanto en la zona lagunar como en altamar

FCNC Top Quark Decays in Extra Dimensions

The flavor changing neutral top quark decay t -> c X is computed, where X is a neutral standard model particle, in a extended model with a single extra dimension. The cases for the photon, X= \gamma$, and a Standard Model Higgs boson, X = H, are analyzed in detail in a non-linear$R_\xi gauge. We find that the branching ratios can be enhanced by the dynamics originated in the extra dimension. In the limit where 1/R >> ->, we have found Br(t -> c \gamma) \simeq 10^{-10} for 1/R = 0.5 TeV. For the decay t -> c H, we have found Br(t -> cH) \simeq 10^{-10} for a low Higgs mass value. The branching ratios go to zero when 1/R -> \infty.Comment: Accepted to be published in the Europ. Phys. Jour. C; 16 pages, 2 figure

Radio-optical scrutiny of compact AGN: Correlations between properties of pc-scale jets and optical nuclear emission

We study the correlations between the Very Long Baseline Array radio emission at 15 GHz, extended emission at 151 MHz, and optical nuclear emission at 5100 AA for a complete sample of 135 compact jets. We use the partial Kendall's tau correlation analysis to check the link between radio properties of parsec-scale jets and optical luminosities of host AGN. We find a significant positive correlation for 99 quasars between optical nuclear luminosities and total radio (VLBA) luminosities of unresolved cores at 15 GHz originated at milliarcseconds scales. For 18 BL Lacs, the optical continuum emission correlates with the radio emission of the jet at 15 GHz. We suggest that the radio and optical emission are beamed and originate in the innermost part of the sub--parsec-scale jet in quasars. Analysis of the relation between the apparent speed of the jet and the optical nuclear luminosity at 5100 AA supports the relativistic beaming model for the optical emission generated in the jet, and allows the peak values of the intrinsic optical luminosity of the jet and its Lorentz factor to be estimated for the populations of quasars, BL Lacs, and radio galaxies. The radio-loudness of quasars is found to increase at high redshifts, which can be a result of lower efficiency of the accretion in AGN having higher radio luminosities. A strong positive correlation is found between the intrinsic kinetic power of the jet and the apparent luminosities of the total and the unresolved core emission of the jet at 15 GHz. This correlation is interpreted in terms of intrinsically more luminous parsec-scale jet producing more luminous extended structure which is detectable at low radio frequencies, 151 MHz. A possibility that the low frequency radio emission is relativistically beamed in superluminal AGN and therefore correlates with radio luminosity of the jet at 15 GHz can not be ruled out (abridged).Comment: 16 pages, 10 figuers; minor comments are added; accepted to A&

ICTD Work, Plus mFeel : improving communication in resource-poor settings

This issue's Works-In-Progress department has four entries related to the issue's theme, Information and Communication Technologies for Development (ICTD). They are “Sustainable ICT in Agricultural Value Chains”, “Measuring Social Inclusion in Primary Schools”, “An Architecture for Green Mobile Computation”, and “Improving Communication in Resource-Poor Settings”. A fifth entry, “mFeel: An Affective Mobile System”, covers the mFeel mobile system, which combines context awareness with affective and cognitive techniques

The influence of semantic and phonological factors on syntactic decisions: An event-related brain potential study

During language production and comprehension, information about a word's syntactic properties is sometimes needed. While the decision about the grammatical gender of a word requires access to syntactic knowledge, it has also been hypothesized that semantic (i.e., biological gender) or phonological information (i.e., sound regularities) may influence this decision. Event-related potentials (ERPs) were measured while native speakers of German processed written words that were or were not semantically and/or phonologically marked for gender. Behavioral and ERP results showed that participants were faster in making a gender decision when words were semantically and/or phonologically gender marked than when this was not the case, although the phonological effects were less clear. In conclusion, our data provide evidence that even though participants performed a grammatical gender decision, this task can be influenced by semantic and phonological factors