Influence of an Anomalous Temperature Dependence of the Phase Coherence Length on the Conductivity of Magnetic Topological Insulators.

Magnetotransport constitutes a useful probe to understand the interplay between electronic band topology and magnetism in spintronic devices. A recent theory of Lu and Shen [Phys. Rev. Lett. 112, 146601 (2014)PRLTAO0031-900710.1103/PhysRevLett.112.146601] on magnetically doped topological insulators predicts that quantum corrections Δκ to the temperature dependence of conductivity can change sign across the Curie transition. This phenomenon has been attributed to a suppression of the Berry phase of the topological surface states at the Fermi level, caused by a magnetic energy gap. Here, we demonstrate experimentally that Δκ can reverse its sign even when the Berry phase at the Fermi level remains unchanged. The contradictory behavior to theory predictions is resolved by extending the model by Lu and Shen to a nonmonotonic temperature scaling of the inelastic scattering length showing a turning point at the Curie transition.

Dietary habits and cardiovascular risk in the Spanish population: the DRECE study (II) micronutrient intake. Dieta y Riesgo de Enfermedades Cardiovasculares en España.

OBJECTIVE: To evaluate the dietary micronutrient intake in the adult Spanish population participating in the DRECE study. METHODS: The cross-sectional study was performed in two stages in 1991 and 1996 in 43 primary care clinics. One thousand two hundred people 'with cardiovascular risk' and 600 'without risk' answered a food frequency questionnaire. RESULTS: Significant increases in vitamin C, retinol, lycopenes, beta-cryptoxanthin and vitamin E intakes were found. Vitamin A, alpha-carotenoid and lutein intakes decreased. Vitamin B(12), B(6) and folic acid intakes increased in people with cardiovascular risk, whereas only the last two increased in the control group. Nearly 100% of the people consumed the recommended dietary allowances for vitamins B(12) and B(6) and >70% for folic acid. Calcium, iron, and zinc intake increased in both groups, but magnesium and selenium intake increased only in people at risk. Vitamin A, B(1) and zinc intakes have decreased, and >50% of the people do not consume the recommended dietary allowance. CONCLUSION: Antioxidant vitamins and vitamin B(12), B(6) and folic acid intakes seem to be adequate in the adult Spanish population, no significant differences appear regarding their cardiovascular risk status. Vitamin A, B(1) and zinc intakes are not appropriate.

Dietary habits and cardiovascular risk in the Spanish population: the DRECE study (I). Diet and Cardiovascular Events Risk in Spain.

BACKGROUNDS/AIMS: To investigate dietary habits and their evolution with regard to cardiovascular risk status in Spain. METHODS: Cross-sectional study performed in two phases in 1991 and 1996 in 43 primary care clinics. One thousand and two hundred people classified as 'with cardiovascular risk' and 600 'without risk' were studied. Each participant answered a food frequency questionnaire. RESULTS: The risk group did not change oil, cereals and dairy products consumption, decreased egg, legume and meat, and increased fish, fruits and vegetables intake. The control group differed in increasing dairy products and not decreasing eggs and vegetables consumption. A small decrease in energy intake happened, from 11,315. 1 to 10,941.5 kJ in the risk group (p < 0.05). Carbohydrates intake showed a not statistically significant falling trend from 41.3 to 40.6% in people at risk and 41.8 to 40.7% in those without risk. Protein intake increased in both groups up to 16.5% and fat consumption kept at around 42.9% in both groups. The decrease in saturated fat and increase in polyunsaturated fat were statistically significant in people at risk (p = 0.000). High cholesterol intakes were found. CONCLUSION: People with cardiovascular problems changed their dietary habits in a 'healthier' way than people without risk.

[Tobacco consumption in the population insured by Mexican Institute of Social Security]. / Consumo de tabaco en la población derechohabiente del Instituto Mexicano del Seguro Social.

OBJECTIVE: To determine the prevalence of tobacco consumption among the active insured population of the Mexican Social Security Institute. MATERIAL AND METHODS: A cross-sectional study in which the active insured population from the 36 political delegations was interviewed by means of a structured and self-applicable questionnaire on tobacco consumption, age of initiation, amount of cigarettes consumed and suspension. RESULTS: The sample consisted of 45 117 subjects, of which approximately half were men and half women. Smoking prevalence in men was 40% and in women, 17.6%. Prevalence was highest in the north of the country. There is an effect of age on tobacco consumption and more than half started smoking during adolescence. CONCLUSIONS: Smoking prevalence was found to be high, however, the average number of cigarettes is low. Suspension index is low. Public health measures are necessary to diminish this addiction.

[Epidemiologic aspects of the aged at the Mexican Institute of Social Security]. / Aspectos epidemiológicos del adulto mayor en el Instituto Mexicano del Seguro Social.

OBJECTIVE: The objective of this study is to present dynamic changes within the population over 65 years of age who are covered by the Mexican Institute of Social Security (MISS), through morbidity and mortality analysis, during the last 6 and 10 years respectively. MATERIAL AND METHODS: Based on data from the Epidemiologic Bulletins from 1990 to 1995 and from 1985 to 1994, the morbidity and mortality rates, respectively, were calculated for the Mexican population over 65 who are covered by the MISS. Incidence of diseases was used as a measure of occurrence and the ratio of morbidity and mortality rates was calculated as the measure of effect. RESULTS: An epidemiological transition exists, with a tendency towards aging among this population. In terms of morbidity, infectious and chronic diseases coexist; as for mortality, chronic-degenerative diseases predominate. CONCLUSIONS: This represents a challenge for health care within institutional services, as this population group begins to compete with other priority groups and emergency needs. Epidemiological surveillance and research is essential to support decision-making.

[The need, supply and demand for epidemiological research personnel in the Instituto Mexicano del Seguro Social]. / Necesidades, oferta y demanda de personal en investigación epidemiológica en el Instituto Mexicano del Seguro Social.

In 1991 the Directorate of Public Health was created at the Mexican Institute for Social Security, with its epidemiologic activities oriented towards surveillance and research. This new vision, as well as the epidemiologic transition in Mexico, have raised the need for researchers training. In 1988 the Specialization Course in Public Health was developed as a response to the detected needs. This course was reformed three years later in duration, depth and name (Epidemiology instead of Public Health). The requirement of a thesis has led to the development of epidemiologic and health services research. Two diplomates in epidemiology and immunology and microbiology were also developed as a response to the need of actualization due to the advances in epidemiologic methodology in the past decades. A demand for actualization and continuous education has been expressed by the epidemiologists through a survey. The Directorate has also proposed priority themes for research in order to guide the requirements of research raised by the epidemiologist already trained at the Institute.