RESUMO
Hydrological and erosion dynamics are prone to change due to natural factors, human activities, or climate change. These changes are mainly related to modifications of land use and cover and can be assessed through the concept of connectivity, which analyzes how the spatial distribution of the elements facilitates runoff and sediment transport. The objective of this study was to evaluate changes in hydrological and sediment connectivity over 42 years and projected under a climate change scenario in the tropical Santa Cruz catchment in Aquismón, S.L.P., Mexico. The index of connectivity (IC) was computed using SedInConnect version 2.3 and the ArcSWAT model to estimate runoff. Hydrological connectivity and runoff were projected for 2027 using the MPI ECHAM 5 in the A2 climate change scenario. The results indicated that spatio-temporal changes in land use/cover, in conjunction with geomorphological features and expected climate change, would modify hydrological and sediment connectivity, especially in flat areas, where conversion of natural vegetation to cropland was steadily increasing over the years. Under future conditions, runoff and sediment transport are likely to increase, which will impact soil erosion and vulnerability to flooding but will not necessarily be negative. The study shows how spatial-temporal integration of runoff, sediments, landforms, land use cover and change, and connectivity can improve our understanding of catchment dynamics and the importance of analyses that characterize their evolution. The results can subsequently be applied and replicated in other catchments for management and restoration purposes.
Assuntos
Mudança Climática , Hidrologia , Inundações , Atividades Humanas , Humanos , MéxicoRESUMO
Connectivity is an emergent property that describes how complex topography favors or impedes sediment transfer processes. In active volcanic areas, high connectivity may lead to extremely efficient processes, such as lahars. The aim of the present study is to examine the behavior (activation-deactivation) of sub-basins affected by volcanic and anthropogenic processes by studying the changes in connectivity and hydrological efficiency. Two volcanic zones in Mexico were selected: Volcán de Colima and Popocatépetl volcano, the two most active and dangerous volcanoes in the country. The joint index of connectivity (ICJ) and lateral hydrological efficiency index (LHEI) were calculated for both volcanic areas in basins recently affected by eruptive activity (Volcán de Colima) and co-seismic landslides (Popocatépetl). The analyses enabled the identification of eleven recently activated sub-basins (3.82â¯km2) at the Volcán de Colima and fifteen (3.77â¯km2) at the Popocatepetl volcano, as a consequence of natural processes and economic activities. Critical thresholds indicating the percentage area of land cover/use at which a sub-basin reaches high or very high LHEI values and the percentage of land cover/use change required for a sub-basin to modify its behavior (activation-deactivation) were identified using classification trees. The holistic capacity of the concepts of connectivity and hydrological efficiency permits analyzing the spatiotemporal variations of sediment transport based on the interactions between the hydrogeomorphological dynamics of volcanic processes and the territorial impact of socio-economical activities. Through this approach, new active areas have been identified in both volcanoes; the knowledge of the processes that occurred in these areas represents a key factor for hazard and risk assessment for the population in the near future.
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Concentration of essential (Se, Zn and Cu) and non-essential (As, Cd, Hg and Pb) trace elements were measured in selected tissues of two dead whale sharks (Rhincodon typus) stranded in the Gulf of California (GC) in 2017 and 2018. Concentrations of Cd and Pb in the skeletal muscle of the whale shark from La Paz Bay, GC were higher compared to a previous study on whale shark from China. The shark from La Paz Bay also presented higher concentration of Pb in the epidermis, compared to the same tissue of the other whale shark stranded in Punta Bufeo, GC. The Hg in all analysed tissues was lower than those documented in carnivorous sharks. Molar ratio Se:Hg shows an excess of Se over Hg in all the tissues sampled in both sharks.
Assuntos
Monitoramento Ambiental/métodos , Epiderme/química , Metais Pesados/análise , Músculo Esquelético/química , Tubarões/metabolismo , Oligoelementos/análise , Poluentes Químicos da Água/análise , Animais , Baías/química , México , Oceano PacíficoRESUMO
The mining district of El Triunfo (ET-MD) has an estimated 800,000 t of mine wastes scattered in the environment, contaminating the sediment with potentially toxic elements such as As, Cd, Pb, and Zn. In order to estimate the toxicity of the sediment to the adjacent biota, the aims of our study are to calculate the mortality and inhibition through bioassays, using sediment, and test organisms such as Daphnia magna and Selenastrum capricornutum (Pseudokirchneriella subcapitata), respectively. The D. magna mortality was 31 ± 12% and the S. capricornutum growth inhibition was 53 ± 24%. The contamination of the sediment determines the high mortality of D. magna and the high inhibition of S. capricornutum in the system, indicating risk for the biota in the contaminated system.
Assuntos
Monitoramento Ambiental , Sedimentos Geológicos/análise , Mineração , Poluentes do Solo/toxicidade , Animais , Bioensaio , Clorófitas , Daphnia , Sedimentos Geológicos/química , Ouro , Poluentes do Solo/análise , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidadeRESUMO
Las malformaciones arteriovenosas de la vena de Galeno comprenden un raro grupo de anomalías congénitas que pueden causar una morbimortalidad importante, especialmente en neonatos, pero también en lactantes y niños mayores. Presentamos un caso de detección prenatal de aneurisma de la vena de Galeno a las 35 + 5 semanas de gestación en el Centro de Referencia Perinatal Oriente. Al examen ultrasonográfico se evidenció una imagen quística supratentorial de 47 por 16 mm, en la línea media del cerebro, asociado a polihidroamnios. El examen con Doppler color demostró el origen vascular de la lesión, con flujo turbulento venoso y arteria. Se realiza resonancia magnética (RM) cerebral fetal que confirma diagnóstico. A las 37 + 2 semanas de gestación se interrumpe el embarazo vía cesárea por inicio de trabajo de parto con monitorización electrónica fetal sospechosa de hipoxia. Evaluado con RM cerebral y angiorresonancia posnatal, en el Instituto de Neurocirugía se declara fuera del alcance terapéutico debido al gran compromiso encefálico. El recién nacido fallece a los siete días de vida. En la presente publicación se realiza una revisión de la literatura referente al tema, destacando la importancia de la consejería prenatal y el manejo multidisciplinario de esta compleja patología.
Assuntos
Masculino , Feminino , Gravidez , Recém-Nascido , Adulto , Humanos , Malformações Arteriovenosas/diagnóstico , Malformações Arteriovenosas/terapia , Veias Cerebrais/anormalidades , Embolia Intracraniana/diagnóstico , Evolução Fatal , Fístula Arteriovenosa/diagnóstico , Imageamento por Ressonância Magnética , Terceiro Trimestre da Gravidez , Ultrassonografia Doppler em Cores , Ultrassonografia Pré-NatalAssuntos
Anti-Infecciosos Urinários/farmacologia , Anti-Infecciosos/farmacologia , Infecções Bacterianas/tratamento farmacológico , Infecções Bacterianas/microbiologia , Infecções Urinárias/tratamento farmacológico , Infecções Urinárias/microbiologia , Anti-Infecciosos/efeitos adversos , Anti-Infecciosos Urinários/efeitos adversos , Criança , Resistência Microbiana a Medicamentos , Escherichia coli/efeitos dos fármacos , Escherichia coli/isolamento & purificação , Infecções por Escherichia coli/tratamento farmacológico , Infecções por Escherichia coli/microbiologia , Fluoroquinolonas , Humanos , Técnicas In Vitro , Testes de Sensibilidade Microbiana , VenezuelaAssuntos
Antibacterianos/farmacologia , Resistência Microbiana a Medicamentos , Escherichia coli/efeitos dos fármacos , Infecções Urinárias/microbiologia , Resistência Microbiana a Medicamentos/genética , Escherichia coli/genética , Infecções por Escherichia coli/microbiologia , Frequência do Gene , Humanos , Testes de Sensibilidade Microbiana , Peru/epidemiologiaAssuntos
Bactérias Anaeróbias , Infecções Bacterianas/etiologia , Mordeduras e Picadas/complicações , Cães , Anaerobiose , Animais , Antibacterianos/uso terapêutico , Bactérias Anaeróbias/classificação , Infecções Bacterianas/tratamento farmacológico , Mordeduras e Picadas/microbiologia , Humanos , MEDLINERESUMO
The background of a successful clinical diagnosis of an anaerobic infection is dependent, to a large extent, on the skills, knowledge and awareness that the examining clinician acquired during his or her time as a medical student. To assess the quality of current teaching protocols in anaerobic microbiology in Venezuela, a survey was carried out among 300 medical students attending three medical schools. The survey consisted of a questionnaire of 18 questions on fundamental aspects of anaerobic bacteria,the infections they cause and their treatment. Although there was only a poor response rate (from 16% of students), the conclusion of the study was that there was a distinct lack of knowledge and appreciation of anaerobic infections among medical students in Venezuela.
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INTRODUCTION AND OBJECTIVE: To study hemorheological factors in patients with ischemic cerebrovascular disease (not secondary to embolic cardiopathy). PATIENTS AND METHODS: We assessed 40 patients with an average age of 64.5 years; 26 had cerebral infarcts due to alterations in major blood vessels and 14 had lacunar infarcts. Forty persons with no cerebrovascular disease acted as controls. The hematological studies were done between three weeks and six months after the initial ictus. RESULTS: Blood viscosity and plasma fibrinogen concentrations were significantly higher in the patients than in the controls. However, hematocrit values were similar in all three groups studied. With regard to the hematocrit, fibrinogen levels and blood viscosity, no differences were seen between the group with damage to the great vessels and those with lacunar infarcts.
Assuntos
Isquemia Encefálica/sangue , Doença Aguda , Adulto , Viscosidade Sanguínea/fisiologia , Feminino , Fibrinogênio/análise , Hematócrito , Hemorreologia , Humanos , MasculinoRESUMO
OBJECTIVE: To study the blood levels of a group of lipids and lipoproteins in patients with ischemic cerebrovascular disease which was not secondary to cardiac embolic disease. PATIENTS AND METHODS: We assessed 40 patients of an average age of 64.5 years. Of these, 26 had cerebral infarcts due to disease of the great vessels and 14 had lacunar infarcts. Forty persons with no cerebrovascular disease were used as controls. We excluded patients diagnosed as having renal failure, liver, hematological, neoplastic and acute febrile disorders. Plasma was analyzed for total cholesterol, triglycerides, lipoproteins (a), HDL, LDL, VLDL and apoprotein B between 3 weeks and 6 months after the initial stroke. RESULTS AND CONCLUSIONS: Levels of triglycerides and of lipoprotein (a) were significantly greater in patients than in controls. We found no differences between the levels of total cholesterol, HDL, LDL, VLDL in the three groups studied. However, apoprotein B was greater in the controls than in the patients. There were no significant differences between the groups with lacunar ictus and those with infarcts secondary to disease of the great vessels.
Assuntos
Isquemia Encefálica/sangue , Lipídeos/sangue , Lipoproteínas/sangue , Idoso , Idoso de 80 Anos ou mais , Apolipoproteínas B/sangue , Isquemia Encefálica/epidemiologia , Infarto Cerebral/sangue , Infarto Cerebral/epidemiologia , Comorbidade , Cuba/epidemiologia , Diabetes Mellitus/epidemiologia , Feminino , Humanos , Hipertensão/epidemiologia , Masculino , Pessoa de Meia-Idade , Grupos Raciais , Estudos Retrospectivos , Fatores de Risco , Fumar/epidemiologiaRESUMO
In Cuba, the illness that produces most deaths among 1-64-year-olds is cancer. Over 65, it is the second cause of death after heart diseases. A National Cancer Registry was created 1964. Its main goals are to register all malignant neoplasms diagnosed in the country, to study this disease from the statistical and epidemiological point of view and to aid in the health control and planning of cancer fighting resources. This paper presents the results based on cases registered from 1986 to 1990. More than 50% of incidence and mortality caused by cancer is confined to the five major primary sites: lung, prostate, colon, breast and cervix. World population standardised rates by 100,000 inhabitants for the period 1986-1990 were 218.2 in males and 183.7 in females for incidence and 138.4 in males and 95.1 in females for mortality. Cancer incidence distribution by provinces shows two major regions: western-central, where higher risks of lung, breast, prostate and colon cancers are found, and eastern where very high risk of cervix cancer is observed. Although an improvement of the information quality indexes has been reported by the National Cancer registry in the studied period of time, quality of the data remained very poor according to the international standards. However, the results obtained by the National Cancer Registry seem to be a valuable tool to evaluate the cancer burden and, in particular, to control and eventually modify the tasks of the National Cancer Control Program in Cuba.
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Neoplasias/epidemiologia , Sistema de Registros/estatística & dados numéricos , Adolescente , Adulto , Distribuição por Idade , Idoso , Causas de Morte , Criança , Pré-Escolar , Cuba/epidemiologia , Feminino , Humanos , Incidência , Lactente , Masculino , Pessoa de Meia-Idade , Neoplasias/mortalidade , Razão de Chances , Sistema de Registros/normas , Distribuição por SexoRESUMO
The immunohistochemical techniques may be very useful for the detection of antigens of the dengue virus in infected tissues. The results obtained with the use of 2 IHC methods: one direct and another indirect amplified with a biotin universal antibody and a streptavidin peroxidase system (LSAB) (the peroxidase enzyme is used in both) are shown in this paper. These methods were applied on paraffin-embedded tissues from mice that were inoculated with the dengue virus intracerebrally. Our objective is to have a technique at the laboratory allowing to identify these antigens in the tissues in order to apply them on the diagnosis and on the studies connected with the obtention of immunogens.
Assuntos
Antígenos Virais/análise , Encéfalo/virologia , Vírus da Dengue/isolamento & purificação , Dengue/virologia , Técnicas Imunoenzimáticas/normas , 3,3'-Diaminobenzidina , Animais , Anticorpos Monoclonais/imunologia , Biotinilação , Encéfalo/patologia , Corantes , Criopreservação , Dengue/patologia , Vírus da Dengue/imunologia , Humanos , Camundongos , Inclusão em ParafinaRESUMO
47 transesophageal echocardiograms (TEE) were performed on 43 patients (27 men and 20 women) in 30 months. The average age was 52.1 +/- 24.3 years. The most frequent indications for the procedure were: search for the source of emboli in 15 patients, suspected endocarditis and valvulopathies in 11. The main findings were intracavitary thrombi in 9 and vegetations in 8. The findings on TEE changed the medical management in 22 patients, confirmed suspected diagnosis in 15, and added nothing new in 10. Hypotension occurred in only one patient and resolved when the transducer was withdrawn. Comparing their results with those found in the literature the authors found that the indications were similar. TEE is an easy, safe and trustworthy study in selected patients
Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Cardiopatias , Ecocardiografia Transesofagiana , PanamáRESUMO
47 transesophageal echocardiograms (TEE) were performed on 43 patients (27 men and 20 women) in 30 months. The average age was 52.1 +/- 24.3 years. The most frequent indications for the procedure were: search for the source of emboli in 15 patients, suspected endocarditis and valvulopathies in 11. The main findings were intracavitary thrombi in 9 and vegetations in 8. The findings on TEE changed the medical management in 22 patients, confirmed suspected diagnosis in 15, and added nothing new in 10. Hypotension occurred in only one patient and resolved when the transducer was withdrawn. Comparing their results with those found in the literature the authors found that the indications were similar. TEE is an easy, safe and trustworthy study in selected patients.