300 research outputs found

    Aportes de la Geologia e Ingenieria a la recuperación de areas afectadas por carcavamiento.

    Get PDF
    El trabajo se realizo en el sitio arqueológico Shincal de Quimivil, (Londres - Belén, Catamarca). El clima es árido continental, las precipitaciones irregulares, violentas y torrenciales, generan un ámbito propicio para una fuerte actividad hídrica. La erosión hídrica superficial se manifiesta desde surcos de canalización de la escorrentía, hasta cárcavas de importantes dimensiones que afectan las estructuras del sitio. Otro factor importante es la presencia de ctenomys, puesto que sus cuevas ofrecen una vía de infiltración y escurrimiento hídrico subsuperficial. Se han reconocido y cartografiado cinco cárcavas y tres vías principales de escurrimiento superficial que alimentan las cárcavas exacerbando la erosión retrocederte en las cabeceras.\ud Durante este trabajo se realizo reconocimiento de campo; relevamiento geomorfológico del área, relevamiento planialtimétrico del Sitio, del conjunto de cárcavas, de cada cárcava presente y de vías principales de escurrimiento superficial.\ud Se elaboro la cartografía temática, el análisis estadístico de datos y la vinculación de los datos numéricos, cartográficos y bibliográficos, en base a lo cual, se efectuó el análisis y propuesta de estrategias de corrección y control de las cárcavas que afectan las estructuras combinando obras hidráulicas, estructuras mecánicas y repoblación vegetal con especies autóctonas

    Clasificación de los trastornos del sueño

    Get PDF
    Sleep disorders are frequent processes, both as a symptom associated with other diseases and as independent disorders. However, only in the last 4 decades has Sleep medicine gained its position among the medical specialties. In fact, it was only in these years that significant advances were obtained in the study of the etiology and treatment of these disorders. Similarly, the different classifications have been evolving over the years. First, they were based upon the clinical symptom; later on, more emphasis was given to the diseases. Finally, in 2005, the new classification was once again based on the symptoms. More than 90 disorders are listed in this latest classification, and an attempt is made to include the symptoms and the diseases of sleep, as well as those in which sleep disorders are fundamental. It is essential to have a clear idea of this complete classification of sleep disorders in order to deal with these patients appropriately

    Las hormonas sexuales modulan el crecimiento renal compensador (CRC) y la función renal en la uninefrectomía (uNx)

    Get PDF
    The role played by sexual hormones and vasoactive substances in the compensatory renal growth (CRG) that follows uninephrectomy (uNx) is still controversial. Intact and gonadectomized adult Wistar rats of both sexes, with and without uNx, performed at 90 days age, were studied at age 150 days. Daily urine volume, electrolyte excretion and kallikrein activity (UKa) were determined. Afterwards, glomerular filtration rate and blood pressure were measured, the kidneys weighed and DNA, protein and RNA studied to determine nuclei content and cell size. When the remnant kidney weight at age 150 days was compared with the weight of the kidney removed at the time of uNx, male uNx rats showed the greatest CRG (50%) while growth in the other uNx groups was 25%, 15% and 19% in orchidectomized, female and ovariectomized rats, respectively. The small CRG observed in the uNx female rats was accompanied by the lowest glomerular filtration value, 0.56 ± 0.02 ml/min/g kwt compared, with the other uNx groups, p < 0.05. Cell size (protein or RNA/DNA) was similar for all the groups except for uNx orchidectomized rats. In this group the cytoplasmatic protein or RNA content was lower than in the other groups while DNA (nuclei content) was similar. Some degree of hyperplasia was determined by DNA content in the uNx groups. Male sexual hormones positively influenced CRG and its absence modulated cell size. Female sexual hormones, instead, did not appear to stimulate CRG. The kallikrein kinin system may not be involved in CRG.La importancia que pueden tener las hormonas sexuales y sustancias vasoactivas sobre el crecimiento renal compensador (CRC) que sigue a la uninefrectomía es aún materia de debate. Se estudiaron ratas Wistar de ambos sexos, a los 150 días de vida, intactas y gonadectomizadas con y sin uNx, realizada a los 90 días de vida. Se midió volumen urinario diario y excreción de electrolitos y actividad de kalikreína urinaria. Se midió filtrado glomerular y presión arterial media extrayéndose luego los riñones que fueron pesados y preparados para estudios histológicos y determinación de ADN, ARN y proteínas para estimar contenido nuclear y tamaño celular. El CRC fue calculado comparando el peso del riñón al momento de las uNx (90 dias de vida) con aquel obtenido a los 150 días de vida. En las ratas macho uNx se observó el mayor CRC (50%) mientras que, en los otros grupos uNx solo alcanzó un 25%, 15% y 19%. El filtrado glomerular acompañó los cambios morfológicos observándose el menor filtrado en las ratas hembras uNx respecto al resto de los grupos 0.56 ± 0.02, p < 0.05. El tamaño celular (proteína o ARN/ ADN) fue similar para todos los grupos excepto para los orquidectomizados uNx, cuyo contenido citoplasmático fue menor. El contenido nuclear (ADN) fue semejante en todos los grupos. Se observó que el CRC está influenciado positivamente por las hormonas sexuales masculinas y su ausencia modula el tamaño celular. La falta de hormonas sexuales femeninas, en cambio, afecta negativamente el CRC. El sistema kalikreína kinina no parecería estar involucrado en el CRC.Fil: Azurmendi, Pablo Javier. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Houssay. Instituto de Investigaciones Medicas; ArgentinaFil: Oddo, Elisabet M.. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Houssay. Instituto de Investigaciones Medicas; ArgentinaFil: Toledo, Jorge E.. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Houssay. Instituto de Investigaciones Medicas; ArgentinaFil: Martin, Rodolfo Santiago. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Houssay. Instituto de Investigaciones Medicas; ArgentinaFil: Ibarra, Fernando R.. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Houssay. Instituto de Investigaciones Medicas; ArgentinaFil: Arrizurieta, Elvira. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Houssay. Instituto de Investigaciones Medicas; Argentin

    Alpha and beta phylogenetic diversities jointly reveal ant community assembly mechanisms along a tropical elevational gradient

    Get PDF
    Despite the long-standing interest in the organization of ant communities across elevational gradients, few studies have incorporated the evolutionary information to understand the historical processes that underlay such patterns. Through the evaluation of phylogenetic α and β-diversity, we analyzed the structure of leaf-litter ant communities along the Cofre de Perote mountain in Mexico and evaluated whether deterministic- (i.e., habitat filtering, interspecific competition) or stochastic-driven processes (i.e., dispersal limitation) were driving the observed patterns. Lowland and some highland sites showed phylogenetic clustering, whereas intermediate elevations and the highest site presented phylogenetic overdispersion. We infer that strong environmental constraints found at the bottom and the top elevations are favoring closely-related species to prevail at those elevations. Conversely, less stressful climatic conditions at intermediate elevations suggest interspecific interactions are more important in these environments. Total phylogenetic dissimilarity was driven by the turnover component, indicating that the turnover of ant species along the mountain is actually shifts of lineages adapted to particular locations resembling their ancestral niche. The greater phylogenetic dissimilarity between communities was related to greater temperature differences probably due to narrow thermal tolerances inherent to several ant lineages that evolved in more stable conditions. Our results suggest that the interplay between environmental filtering, interspecific competition and habitat specialization plays an important role in the assembly of leaf-litter ant communities along elevational gradients

    The Mediterranean diet and incidence of hypertension: the Seguimiento Universidad de Navarra (SUN) Study

    Get PDF
    The Mediterranean diet is receiving increasing attention in cardiovascular epidemiology. The association of adherence to the Mediterranean diet with the incidence of hypertension was evaluated among 9,408 men and women enrolled in a dynamic Spanish prospective cohort study during 1999–2005. Dietary intake was assessed at baseline with a validated semiquantitative food frequency questionnaire, and a 9-point Mediterranean diet score was constructed. During a median follow-up period of 4.2 years (range, 1.9–7.9), 501 incident cases of hypertension were identified. After adjustment for major hypertension risk factors and nutritional covariates, adherence to the Mediterranean diet was not associated with hypertension (the hazard ratio was 1.10 (95% confidence interval (CI): 0.81, 1.41) for moderate adherence and 1.12 (95% CI: 0.79, 1.60) for high adherence). However, it was associated with reduced changes in mean levels of systolic blood pressure (moderate adherence, 2.4 mm Hg (95% CI: 4.0, 0.8); high adherence, 3.1 mm Hg (95% CI: 5.4, 0.8)) and diastolic blood pressure (moderate adherence, 1.3 mm Hg (95% CI: 2.5, 0.1); high adherence, 1.9 mm Hg (95% CI: 3.6, 0.1)) after 6 years of follow-up. These results suggest that adhering to a Mediterranean-type diet could contribute to the prevention of age-related changes in blood pressure

    A study of the prostate, androgens and sexual activity of male rats

    Get PDF
    BACKGROUND: The prostate is a sexual gland that produces important substances for the potency of sperm to fertilize eggs within the female reproductive tract, and is under complex endocrine control. Taking advantage of the peculiar behavioral pattern of copulating male rats, we developed experimental paradigms to determine the influence of sexual behavior on the level of serum testosterone, prostate androgen receptors, and mRNA for androgen receptors in male rats displaying up to four consecutive ejaculations. METHODS: The effect of four consecutive ejaculations was investigated by determining levels of (i) testosterone in serum by solid phase RIA, (ii) androgen receptors at the ventral prostate with Western Blots, and (iii) androgen receptors-mRNA with RT-PCR. Data were analyzed with a one-way ANOVA followed by a post hoc application of Dunnett's test if required. RESULTS: The constant execution of sexual behavior did not produce any change in the weight of the ventral prostate. Serum testosterone increased after the second ejaculation, and remained elevated even after four ejaculations. The androgen receptor at the ventral prostate was higher after the first to third ejaculations, but returned suddenly to baseline levels after the fourth ejaculation. The level of mRNA increased after the first ejaculation, continued to increase after the second, and reached the highest peak after the third ejaculation; however, it returned suddenly to baseline levels after the fourth ejaculation. CONCLUSION: Four consecutive ejaculations by sexually experienced male rats had important effects on the physiological responses of the ventral prostate. Fast responses were induced as a result of sexual behavior that involved an increase and decrease in androgen receptors after one and four ejaculations, respectively. However, a progressive response was observed in the elevation of mRNA for androgen receptors, which also showed a fast decrease after four ejaculations. All of these changes with the prostate gland occurred in the presence of a sustained elevation of testosterone in the serum that started after two ejaculations. A consideration of these fast-induced changes suggests that the nerve supply plays a key role in prostate physiology during the sexual behavior of male rats

    Consumo de alcohol e incidencia de hipertensión en una cohorte mediterránea: el estudio SUN

    Get PDF
    Introduction and objectives. To assess prospectively the association between alcohol consumption, including alcoholic beverage preference and days of consumption per week, and the risk of hypertension in a Mediterranean cohort. Methods. We prospectively followed 9,963 Spanish men and women initially without hypertension. Self-reported and validated data on diet and hypertension diagnoses were collected. Results. During follow-up (median [interquartile range], 4.2 [2.5-6.1] years), 554 incident cases of hypertension were identified over a total of 43,562 person-years. The hazard ratio for hypertension among those who consumed alcohol on ≥5 days per week was 1.28 (95% confidence interval, 0.97-1.7) compared to abstainers. Among those who drank alcohol ≥5 days per week, the hazard ratio for hypertension associated with consuming ≥1 drink per day was 1.45 (95% confidence interval, 1.06-2) compared with abstainers. The consumption of beer or spirits, but not wine, was associated with an increased risk of hypertension. The hazard ratio associated with consuming >0.5 drinks of beer or spirits per day was 1.53 (95% confidence interval, 1.18-1.99) compared with abstainers. In contrast, there was a nonsignificant inverse association between red wine intake and the risk of hypertension. Conclusions. In this Mediterranean population, the consumption of beer or spirits, but not wine, was associated with a higher risk of developing hypertension. However, the weekly pattern of alcohol consumption did not have a significant impact on the risk of hypertension

    Aspirin, non-aspirin analgesics and the risk of hypertension in the SUN cohort.

    Get PDF
    The use of aspirin and non-aspirin analgesics has been associated with changes in blood pressure. The aim of this study was to investigate prospectively the association between the regular use of aspirin and non-aspirin analgesics and the incidence of hypertension. METHODS: The SUN project is an ongoing, continuously expanding, prospective cohort of Spanish university graduates initially free of hypertension, cardiovascular disease, diabetes and cancer; 9986 (mean age 36 years) were recruited during 1999-2005 and followed up for a mean of 51 months. Regular aspirin and non-aspirin analgesic use and the presence of other risk factors for hypertension were assessed by questionnaire at baseline, and the incidence of hypertension was assessed using biennial follow-up questionnaires. RESULTS: In total, 543 new cases of hypertension were identified during follow-up. Regular aspirin use (i.e. 2 or more days/week) was associated with a higher risk of hypertension (hazard ratio=1.45; 95% confidence interval, 1.02-2.04) after adjustment for various confounding factors. Regular use of non-aspirin analgesic drugs was also associated with a higher risk of hypertension (hazard ratio=1.69; 95% confidence interval, 1.28-2.23). CONCLUSIONS: The regular use of aspirin and non-aspirin analgesics were both associated with an increased risk of developing hypertension, independently of other risk factors

    Comorbidities in a sample of adults with HIV in Puerto Rico: an exploratory study.

    Get PDF
    Background: Puerto Rico is among the areas with the highest estimated rates of people living with HIV in the United States. Despite the epidemiologic data available, there is limited real-world information that can help understand the comorbidities of people with HIV. In this study, we describe common comorbidities among adults with HIV attending treatment clinics in Puerto Rico. Methods: An exploratory, retrospective, cross-sectional study was conducted at five HIV clinics in Puerto Rico. A random sample of medical records was reviewed. Descriptive statistics were used to summarize patient demographics, morbidity, and clinical characteristics. Multivariate analyses were conducted to explore comorbidities by age and sex. Results: A total of 250 (179 men; 71 women) medical records were reviewed. Participants\u27 mean age was 47.9 years and on average they had been living with HIV for 9 years. Most (97.6%) had at least one comorbidity. The most common comorbidities were dyslipidemia and hypertension. Men were more likely to have been diagnosed with alcohol misuse while women were more likely to have been diagnosed with obesity, human papillomavirus (HPV), hypothyroidism, and osteoporosis. Participants younger than 50 years of age were more likely to have history of alcohol misuse while older individuals (50 years and old) were more likely to have been diagnosed with dyslipidemia, hypertension, and diabetes. Adjusting by sex and age, women were more likely to have been diagnosed with obesity and depression and those older than 50 years were more likely to have had a diagnosis of dyslipidemia, hypertension, HPV, and diabetes. Conclusions: This is one of the few studies assessing comorbidities among adults with HIV in Puerto Rico, among Latino/Hispanics within the United States, and Latin America. Consistent with other studies, cardiovascular diseases are common among adults with HIV in Puerto Rico. Findings support the need for awareness and real-world evidence about comorbidities among people with HIV when implementing screenings and prescribing drugs
    corecore