Solar wind thermally induced magnetic fluctuations.

A kinetic description of Alfvén-cyclotron magnetic fluctuations for anisotropic electron-proton quasistable plasmas is studied. An analytical treatment, based on the fluctuation-dissipation theorem, consistently shows that spontaneous fluctuations in plasmas with stable distributions significantly contribute to the observed magnetic fluctuations in the solar wind, as seen, for example, in [S. D. Bale et al., Phys. Rev. Lett. 103, 211101 (2009)], even far below from the instability thresholds. Furthermore, these results, which do not require any adjustable parameters or wave excitations, are consistent with the results provided by hybrid simulations. It is expected that this analysis contributes to our understanding of the nature of magnetic fluctuations in the solar wind.

Preferential heating and acceleration of alpha particles by Alfvén-cyclotron waves.

Preferential heating and acceleration of heavy ions in the solar wind and corona represent a long-standing theoretical problem in space physics, and are distinct experimental signatures of kinetic processes occurring in collisionless plasmas. We show that fast and slow ion-acoustic waves (IAW) and transverse waves, driven by Alfvén-cyclotron wave parametric instabilities can selectively destroy the coherent fluid motion of different ion species and, in this way lead to their differential heating and acceleration. Trapping of the more abundant protons by the fast IAW generates a proton beam with drift speed of about the Alfvén speed. Because of their larger mass, alpha particles do not become significantly trapped and start, by conservation of total ion momentum, drifting relative to the receding bulk protons. Thus the resulting core protons and the alpha particles are differentially heated via pitch-angle scattering.

[Consumption of licit and illicit drugs in Chile: results of the 1998 study and comparison with the 1994 and 1996 studies]. / Consumo de drogas lícitas e ilícitas en Chile: resultados del estudio de 1998 y comparación con los estudios de 1994 y 1996.

The principal results are presented here from the Third National Study of the Consumption of Drugs, which was carried out in Chile by the National Board for Narcotics Control between 1 September 1998 and 15 January 1999. The 1998 study used the same methodological design as the first and second studies, which were done in 1994 and 1996. The 1998 study expanded the sample to 31,665 individuals, who were representative of a population of 6,940,727 people from 12 to 64 years old, both sexes, and five socioeconomic levels and who were residents of urban areas in 62 commune administrative divisions of the 13 regions of the country. Results from the 1998 study are compared with those from 1996 and 1994. The 1998 study shows that 17.5% of Chileans have at some time in their life used one of the three illicit drugs most popular in the country: marijuana (16.8%), coca paste (2.3%), and cocaine hydrochloride (4.0%). The prevalence of use of any of the three drugs, mainly marijuana, during the preceding year was 5.3% and during the preceding month 2.2%. With respect to licit drugs, 28.4% of Chileans have at some time in their lives used antianxiety drugs, 84.4% of them have consumed alcohol, and 71.9% have used tobacco. Most of the people who once used illegal drugs have stopped doing so: 71.6% in the case of marijuana, 64.1% with coca paste, and 66.8% with cocaine hydrochloride. For legal drugs, the percentages were lower: 55.5% for anxiolytics, 16.0% for alcohol, and 34.5% for tobacco. The consumption of licit and illicit drugs was several times greater among men than among women, except for anxiolytics, whose use was three times greater among women. Drug use was more frequent among persons between 19 and 25 years old. Consumption of illegal drugs was more frequent at higher socioeconomic levels, and use of licit drugs was more common in the lower socioeconomic levels. The 50th percentile of the age of initiating drug use was 17 years for alcohol, 15 for tobacco, 30 for antianxiety agents, 17 for marijuana, 20 for coca paste, and 21 for cocaine hydrochloride. Comparing the results of the three studies shows that, after an increase in the use of licit drugs between 1994 and 1996, there was a stabilization in 1998. With illegal drugs there was a modest increase in consumption between 1996 and 1998, following a small reduction between 1994 and 1996.

[What, how much and when the university student drinks]. / Qué, cuánto y cuándo bebe el estudiante universitario.

The aim of this work was to define the epidemiological profile of alcohol ingestion and its associated risks, in university students. A social survey about drinking habits was performed to a random sample of 528 students, aged 17 to 26 years old, 54% male, from Austral University. Eighty two percent of males and 79% of females drink alcoholic beverages. They mainly consume beer and strong spirits. Their main consumption is occasional, during parties or celebrations. Thirty percent of males and 15% of females had three or more inebriations during the last year. Nine percent of males and 3% of females can be considered as problem drinkers. Student that drink alcohol have lower grades that teetotalers. It is concluded that alcohol consumption is frequent among students.

[Regional analysis of human and animal hydatidosis in Chile, 1989-1993]. / Análisis regional de la hidatidosis humana y animal en Chile, 1989-1993.

A descriptive study of hydatidosis, a still very prevalent zoonosis in Chile, was carried out with information up to 1993. Both human and animal data were included, the last one based on more reliable information. Regional human distribution up to 1991 shows persistent high notification rates in the extreme south of the country, Aysen and Magallanes hospital discharges, more reliable than notified cases, adds the IX Region of Araucania to the high risk areas, join with more than 30 hospitalizations per 100,000 people in 1989. Mortality case rate suggests strongly a very high subnotification in all the regions, mainly in O'Higgins. This zoonosis affects predominantly, young and middle aged adults, with a similar sex distribution. Cattle infection has decreased in the last 20 years, particularly in sheep. Proportion of infected dogs also tends to show a lowering trend in specific studies. It appears a strong need of a national program for controlling this zoonosis, to be initiated with an epidemiological evaluation by regions and centered in health education, dogs' infection control with treatment and better handling of slaughterhouses.

[Epidemiological profile of liver cirrhosis in Chile 1970-1992]. / Perfil epidemiológico de la cirrosis hepática en Chile 1970-1992.

BACKGROUND: Liver cirrhosis is an important public health problem in Chile. AIM: To review the main epidemiological features of liver cirrhosis in Chile in the last 22 years. METHODS: Review of yearbooks of mortality and causes of death of the Ministry of Health and Instituto Nacional de Estadísticas, review of hospital discharges and review of international statistics published by the World Health Organization. RESULTS: The mortality rate of liver cirrhosis in 1992 was 17.9/100,000 inhabitants and represented 3.3% of all deaths. The risk of cirrhosis is higher among men and in people over 64 years of age. In the last decade, death rates of young adults (15-44 years old) and children decreased dramatically. Hospital discharge rates for cirrhosis have decreased from 46.7 in 1970 to 40.4 in 1992. The men/women ratio in 1991 was 2.1/1 for hospital discharges and 2.8/1 for mortality. Mortality was higher in large urban areas (Santiago, Valparaíso and Concepción). A correlation of +0.17 was found between death rates for cirrhosis and wine production per capita. CONCLUSIONS: Cirrhosis continues to be a highly prevalent disease in Chile.

[Current situation of human hydatidosis in Chile. 2 proposals for correcting its undernotification]. / Situación actual de la hidatidosis humana en Chile. Dos propuestas de corrección de su subnotificación.

Hydatidosis continues to be a prevalent disease in Chile. Since 1985 and until 1990, the number of notified cases decreased abruptly, probably due to sub-notification. Lethality, not calculated officially, increased since 1985 in a roughly similar proportion to the decrease in communicated incidence. This fact, along with an increase in hospital discharges due to the disease in the country, confirms the hypothesis that sub-notification is true. Two estimation systems for the magnitude of sub-notification are proposed, one based in the expected lethality and the other in the corrected hospital discharges, taking into account the phenomenon of re-admission. Both systems, although differing, disclose much higher incidence of hydatidosis than the communicated figure. A critical analysis of both systems is done.

[Sexual behavior and contraceptive practices among university students]. / Comportamiento sexual y prácticas anticonceptivas del estudiante universitario.

The aim of this work was to study the knowledge, opinions and sexual behaviour of a sample of 464 students from the Universidad Austral de Chile. Results show that 78% of male and 41% of female students have had a sexual intercourse and that 78% of males and 72% of females with an active sexual life use contraceptive methods. The principal reasons to avoid the use of these methods are the irregularity of sexual intercourse and the reduction in pleasure. Most students think that these methods are harmful for their health but they should be used. The use of contraceptive methods increase with the frequency of sexual relations and university experience, but first year students use them more frequently than second year students. Most students know several contraceptive methods, but their knowledge about mechanisms of action is inadequate or distorted. Likewise, more than 50% think that it is possible to prevent pregnancy after a sexual intercourse. It is concluded that most sexually active students use contraceptive methods, but inappropriately. Stereotypes, myths and lack of information are influencing their sexual and contraceptive practices, showing incoherence between their knowledge and behavior. A possible explanation could be a scarce influence of high school and religion on their sexual formation.

PIP: A random sample of 464 students of the University Austral of Chile were surveyed concerning their sexual practices and contraceptive usage. 78% of the male and 41% of the female students had had sexual intercourse. Among male and female students respectively, 21% and 19% had regular sexual relations, 33% and 24% had sporadic relations, and 24% and 20% were not sexually active at the time of the survey. 78% of sexually active males and 72% of sexually active females had ever used contraception. 57% had ever used condoms, 56% withdrawal, and 35% oral contraceptives (OCs). Among the 27% of sexually active students who had never used contraception, 78% cited sporadic relations and 39% reduction in sexual pleasure as reasons for nonuse. Use of contraception increased regularly with age, from 68% of sexually active students under 21 to 85% among students over 23 years old. It increased with frequency of intercourse, from 72% of those with sporadic relations to 91% of those having intercourse weekly or more often. There was no statistically significant relationship between religious background and contraceptive usage. The proportions believing specific contraceptive methods to be harmful to health were 65% for OCs, 53% for IUDs, 29% for injectables, and 19% for spermicides. 69% stated it is always necessary to use contraception. Two-thirds of the sexually active students knew more than three methods. 49% believed that vaginal washing after coitus could prevent pregnancy.

[Epidemiological evolution of human hydatidosis in Chile, 1965-1988. Impact of livestock programs in the XI and XII regions]. / Evolución epidemiológica de la hidatidosis humana en Chile, 1965-1988. Impacto de programas ganaderos en las regiones XI y XII.

The aim of this work was to analyze the possible impact of livestock echinococcosis control programs in the XI and XII regions of Chile, on the incidence of human echinococcosis. National morbidity was stable until 1984, with an abrupt and important decrease afterwards. Mortality showed a slight tendency to decrease during this period. There was an increase in lethality, that was equivalent and contemporary to the communicated decrease in morbidity after 1985. It is concluded that the national and regional decrease in the communicated cases of echinococcosis is due to a decrease in the notification of the disease. This problem was originated in administrative decisions of the Ministry of Health in 1985, whose effects persist. An instrument to correct retrospectively this low notification is proposed.

[University students and sex: what they think, what they know, what they do]. / El estudiante universitario frente al sexo: que piensa, que sabe, que hace?

Using the social survey technique, a random sample of 464 students from the Universidad Austral answered a structured questionnaire about behavior and attitudes towards sex. Results show that the majority of students have had sexual experiences. Men and women differ significantly in motivations and age at the start of their sexual activity, stability of their relationships, first sexual partner and emotional experiences. Sexual behavior is associated with age, years of university studies and geographical origin. On the contrary this behavior is weakly influenced by religion or family. Premarital sexual intercourse is accepted by the majority of students. Knowledge about sexual physiology and contraception is scarce in 30 to 80% of students. It is concluded that, since a great number of students have an active sexual life along with little knowledge in this topic, the University has to assume an active role in the sexual education of students.