Chagas disease, whose aetiological agent is the protozoan Trypanosoma cruzi, mainly occurs in Latin America. In order to know the epidemiology and the geographical distribution of this disease in Mexico, the present work analyses the national surveillance data (10 years) for Chagas disease issued by the General Directorate of Epidemiology (GDE). An ecological analysis of Chagas disease (2007–2016) was performed in the annual reports issued by the GDE in Mexico. The cases and incidence were classified by year, state, age group, gender and seasons. A national distribution map showing Chagas disease incidence was generated. An increase of new cases was identified throughout the country (rates from 0.37 to 0.81 per 100 000 inhabitants). Of the total cases accumulated (7388), the major cases were attributed to the states of Veracruz, Chiapas, Quintana Roo, Oaxaca, Morelos and Yucatán. The analysis per age groups and gender revealed that, in most age groups, the incidence was higher in the male population. The most number of cases was identified in spring and summer; a direct relationship between the environmental temperature increase and the number of new cases was identified. The analysis showed that the rate of Chagas disease increased presumably due to state programmes; the search for new cases has expanded and we speculate that the disease is associated with occupational activities. These results summarise and recall how important it is to implement the monitoring of Chagas disease mainly in south states of the Mexican Republic in order to implement strategies to control this disease.

Pulkovo and Valencia observatories are developing measuring machines based on the “Ascorecord” microscope that allow to undertake automatic measuring programs of different kind of plates (Ortiz et al., 1993). All aspects of astrometry work are covered now by our software: field maps and plate files creation from the PPM and the GSC; precise ephemeris calculation of minor planets and comets, including planetary perturbations; image identification and automatic plate measurement and reduction (Lopez et al., 1994a). For these tasks, correction tables for GSC catalogue vs. PPM, systematic errors (Lopez et al., 1994b) have been obtained. Observing programs using plates and CCD devices at telescope focus are planned (the search of new asteroids and comets, big planets satellites observation, new high density photographic catalogues and some other projects).

The automatic identification and characterization of star images has great value for the preliminary analysis and measurement of astrographic plates. Our group at Valencia Observatory is using a small 2-D stage and a CCD camera under computer control to perform systematic measurements of bright asteroid plates. We are also applying this method to the processing of astrographic plates with crowded stellar fields and non-stellar objects in collaboration with the Pulkovo Observatory.

The SOHO probe was successfully launched on December 2 nd , 1995. The performances of the Atlas II flight, the trajectory and the final injection in the Halo orbit around the L1 Lagrangian point left on board a large amount of hydrazine, allowing the possibility for a mission extension later than the 2 planned years. The operations of the GOLF experiment started on January 16 th for a period devoted to the initial tests and to the adjustments of the thermal settings. The effective solar observations started on February 18 th and are still running. For the studies presented here below, the data set ends in mid-September. All tables and figures come from the compilation of the data analysis made in several institutes with different methods, and some complementary or additional results are displayed in the poster booklet published from this symposium.

It is a fact that, none of the diverse coordinate systems unified in the Post-Newtonian formalism used to describe the exterior Schwarzschild field can be regarded as being materialized by a reference frame. Only the polar Gaussian coordinates (ρ, ϑ, ϕ, t), or their naturally associated Fermi coordinates, can be shown to have this property (Synge, 1960).

We present mid and far-infrared energy distributions of the CfA Seyfert sample, obtained with the Infrared Space Observatory photometer (ISO-PHOT). To analyse the CfA Seyfert SEDS, we apply an inversion method: the Inverse Planckian Transform, assuming that the mid- and far-IR emission is thermal. We obtain the spectral temperature distribution of sources that reproduces the observed SEDS. We compare the parameters of the spectral components found showing that there are not differences between Seyfert 1 and Seyfert 2 as for their temperatures while the emission between 12 and 25 μm is anisotropic.

HR 4047 (HD 89343, EN UMa, V = 592, A7Vn) was found to be variable (Plume & Percy, 1988) with an amplitude of hundredths of a magnitude. Since then, this star has been observed by HIPPARCOS. Koen (2001), analysing those data, obtained two frequencies 6.43185 c d-1 and 4.31308 c d-1.

Our observations were made at the Observatorio de Sierra Nevada in Spain in 1997 and 1998 with the telescope of 0.9m. The comparisons stars for 1997 were C1 = HD 88983 (V = 577, A8III) and C2 = HD 88815 (V = 642, F2V), while for 1998 we add the check star C3 = HD 90838 (V = 7.30, F2). The photometric data obtained were analyzed using the Fourier Transform method in the Strömgren v filter. The periodogram of the v band data is shown in Fig. 1. The periodogram presents six clear frequencies and after prewhitening these there is still more power, but the frequencies found are not consistent between the different bands. Applying these frequencies to the data of the 1997 and 1998 separately, we obtain the results shown in Table 1. Note that the amplitudes have changed from one year to another. The results of 1998 agree with the two frequencies found by Koen (2001). Fig. 1 shows the light curves of the observed data for both campaigns in the v filter. The points represent the observations while the solid lines represent the fit for the frequencies listed in Table 1. Further observations are needed to obtain a more detailed pulsational behaviour of this star.

RZ Cas is an Algol-type eclipsing binary system where the primary component was recently discovered as a δ Set pulsator. A three-continent multisite photometric campaign was carried out during 1999. Preliminary results are reported here indicating a semi-detached system where the secondary fills its Roche lobe. The light curves also suggest a hot spot on the surface of the primary component as a consequence of the impact of the mass stream from the secondary. The pulsational behaviour can be well described with only one frequency.

In order to check the evolutionary status and theoretical models of eclipsing binaries of Algol type, a reliable determination of their absolute dimensions is needed. In this communication, we compare the most commonly used methods to derive absolute parametors in single-lined aclipsing binaries. Let us first assume that the mass function, f(m), is known from the analysis of the radial velocity curve while the relative radii and orbital inclination are derived from the light curve. The determination of absolute parameters is then equivalent to the obtention of the mass ratio, q = m 2/m 1. The following methods are available to estimate q from observed parameters — over-all errors being estimated for observational uncertainties of the order of 5 % in relative radii and temperatures and 15 % in f(m) —:

1. 1. qs: It is assumed that the primary component follows the mass-luminosity relation for main-sequence stars. This procedure provides qs with an uncertainty of about 10 %.
2. 2. qsD: It is assumed that the secondary component fills its Roche lobe. Errors of at least 15 to 20 % are expected from this procedure mainly due to its high sensitivity to small variations in the observed value of r2, particularly if r2 > 0.2. 2.Both methods can be used together when f(m) is doubtful, or completely unknown, but errors can not be expected to be better than in case 2.
3. 3. qn: It is assumed that the primary component rotates synchronously in a circular orbit. This assumption is difficult to adopt due to the expected transfer of angular momentum through mass transfer and the value of qn is estimated with about 20 to 30 % error.
4. 4. qED: It is assumed that the primary component, is well reproduced by standard evolutionary models within the main sequence. Adopting a grid of models for a given chemical composition, an iterative procedure in the log Ti,.–log g plane permits the determination of m1 and thus q. This method is equivalent to (1) but avoids errors due to evolution from the ZAMS to the TAMS, not taken into account in the previous method, and allows to reach a higher accuracy, around 5 %, except for those primary stars located around the TAMS, where the determination of mi is not unique.

Advanced ultra-high strength steels (A-UHSS) are revolutionizing both the steel and automotive industries, therefore it is imperative to study their hot plastic deformation behavior and modeling. The flow characteristics of all hot forming processes consist basically of two competitive phenomena: strain hardening and softening due to dynamic mechanisms (recovery and/or recrystallization). In this research work, the softening parameter was determined in a low carbon A-UHSS microalloyed steel with different amounts of boron (0, 14 and 214 ppm). Experimental stress–strain data of uniaxial hot-compression tests at different temperatures (950, 1000, 1050 and 1100 °C) and strain rates (10–3, 10–2 and 10–1 s–1) were used. The stress–strain relationships as a function of temperature and strain rate were described on the basis of the Estrin, Mecking, and Bergström model. The experimental values of the softening parameter Ω were adjusted using the least-squares method. In general, the results reveal that the softening parameter increases with increasing boron content.

In the present work, the stress relaxation method was employed to determine the influence of B addition on the kinetics of strain-induced precipitation and its interaction with the static austenite recrystallization. For this purpose, the behavior of two low carbon advanced ultra-high strength steels was analyzed during stress relaxation tests at different temperatures and constant pre-strain rate. The precipitation start (Ps) and finish (Pf) times were determined from the relaxation curves and then the corresponding precipitation-time-temperature diagrams were constructed for each steel. Transmission Electron Microscopy was used to determine the chemical nature and evolution of precipitation. In general, the results show that the addition of B retards the austenite recrystallization, tends to accelerate the precipitation kinetics of carbonitrides and leads to a finer and denser distribution of precipitates. These results are discussed in terms of the driving force for the nucleation of precipitation, which in turn is controlled by the degree of supersaturation of microalloying element and as a function of B segregation and B-vacancy complexes to dislocations and grain boundaries.

Nowadays, there are limited referenced data on the hot deformation of twinning induced plasticity (TWIP) steels, particularly on the crystallographic preferred orientation (crystallographic texture). It is well know that texture is one of the most important factors affecting sheet metal forming performance. The aim of this research work is to determine the influence of microalloying elements on the microstructure and texture of high-Mn austenitic TWIP steels deformed under uniaxial hot-tensile conditions. For this purpose, one non-microalloyed and other single microalloyed with Ti, V and Mo TWIP steels were melted in an induction furnace and cast into metal and sand molds. Samples with average austenitic grain size between 400 and 2000 µm were deformed in the temperature range between 800 and 900 °C at a constant true strain rate of 10-3 s-1. The evolution of the microstructure and texture near to the fracture tip were characterized using electron back-scattering diffraction (EBSD) technique. The results show that the TWIP steels microalloyed with V and Mo and the non-microalloyed one, solidified in metal mold, exhibit dynamically recrystallized grains oriented in the [012] preferential direction, which was corroborated by local misorientation measurements, indicating low dislocation density. On the other hand, most TWIP steels solidified in sand molds do not show dynamically recrystallized grains, having the largest austenitic grains oriented in the [001]/[101] preferred directions. In general, weak textural Cube {001}<100> combined with <111> fiber, namely γ-fiber, spread from E {111}<110> to Y {111}<112> as major texture components were detected.

Optical thresholds, that correspond to a level located at 1 eV above the valence band, are observed by photocapacitance techniques in n-type Mg-doped GaN. In undoped GaN, this level has been previously related to the yellow emission detected by photoluminescence. In Mg-doped GaN, this yellow luminescence is only observed for excitation energies below the Mg-related band (2.9 - 3 eV). This result evidences that Mg-doping may reduce but not avoid the formation of the yellow band related defects in n-type and semiinsulating Mg-doped samples. The fact that the yellow luminescence is not observed for excitation energies above the bandgap may be justified by a higher efficiency of the Mg-related recombination path.

Modelling automobile insurance claims is a crucial component in the ratemaking procedure. This paper focuses on the probability that a policyholder reports a claim, where the classical logit link does not provide a right model. This is so because databases related with automobile claims are often unbalanced, containing more non-claims than the presence of claims. In this work an asymmetric logit model, which takes into account the large number of non-claims in the portfolio, is considered. Both, logit and asymmetric logit models from a Bayesian point of view, are used to a sample that was collected from a major automobile insurance company in Spain in 2009, resulting in a dataset of 2,000 passenger vehicle. We establish the validity of the asymmetric model in front of the conventional logit link. The use of a garage, the age of the vehicle and the duration of the client's relation with the company are all shown to be significant explanatory variables by the logit model. The asymmetric model includes, in addition, the length of time the policyholder has held a driving licence and the type of use made of the vehicle. The asymmetric model provides a better fit to the data examined.

Supersulphated cements (SSC) are environmentally friendly binders that incorporate several raw materials, including byproducts. A systematic study was considered opportune considering the wide range of formulations found in the literature. The effect of the type and proportioning of components in the strength of SC was investigated using the Taguchi method to optimize the experimental work and to define the optimal conditions. The factors were: [A] %blast furnace slag (82.5-90%), [B] CaSO4 - alkaline activator ratio (1:0, 3:1, 1:1, 1:3 and 0:1), [C] type of CaSO4 (5 types) and [D] type of alkaline activator (portland cement, Ca(OH)2, KOH and NaCO3 and 2 combinations of these). Pastes were prepared and characterized for up to 28 days at 20°C. In general, for all values of [A] the best strength was for levels of [C] at 3:1, followed by the 1:1 and 1:0 ratios. The optimal conditions using the 28 day strength consisted of [A]= 82.5%, [B]= 3:1, [C]= flyorgypsum and [D] = portland cement, which developed excellent strength from day one and 35MPa. X-ray diffraction showed ettringite and C-S-H formation from the early ages. The microstructures showed dense matrices of reaction products well bonded to partially reacted slag grains, which in some cases showed rims of hydration products.

Extended abstract of a paper presented at Microscopy and Microanalysis 2012 in Phoenix, Arizona, USA, July 29 – August 2, 2012.

The aim of this research work is to study the effect of boron addition on mechanical properties and microstructure of a new family of low carbon NiCrVCu advanced high strength steels (AHSS). Experimental steels are thermo-mechanically processed (TMP) (hot-rolled+quenched). Results show that the microstructure of these steels contains bainite and martensite, predominantly, which nucleate along prior austenite grain boundaries (GB). On the other hand, tensile tests reveal that the TMP steels have YS (0.2% offset) of 978 MPa, UTS of 1140 MPa and EL of 18%. On the basis of exhibited microstructure and mechanical properties, these experimental steels are classified as bainitic-martensitic complex phase (CP) advanced ultra-high strength steels (UHSS).

In the past years artificially-structured materials have been grown with an increasing degree of sophistication due to steady progress in our ability to control growth processes down to the atomic level. These materials have yielded new physical properties due to the confinement of electrons in less than three dimensions. Thus, the confinement of electrons in two-dimensional (2D) metallic superlattices has resulted in oscillatory magnetic coupling with an associated oscillatory giant magnetoresistance (GMR). New properties are expected when the electrons are further confined to one dimension (1D) of free motion in the structures known as quantum wires. In this report we briefly describe two recent examples of atomic-scale engineering of materials. In the first case a surfactant is used to purposely modify the structure of magnetic/non magnetic superlattices. The second example illustrates a further reduction in dimensionality obtained by modifying the substrate onto which the growth takes place: the fabrication of 1D magnetic quantum wires on vicinal surfaces.

We have succeeded in generating highly charged excitons in InAs self-assembled quantum dots by embedding the dots in a field-effect heterostructure. We discover an excitonic Coulomb blockage: over large regions of gate voltage, the exciton charge remains constant. We present here a summary of the emission properties of the charged excitons.