Predicting soil water content at - 33 kPa by pedotransfer functions in stoniness 1 soils in northeast Venezuela.

Soil water content is a key property in the study of water available for plants, infiltration, drainage, hydraulic conductivity, irrigation, plant water stress and solute movement. However, its measurement consumes time and, in the case of stony soils, the presence of stones difficult to determinate the water content. An alternative is the use of pedotransfer functions (PTFs), as models to predict these properties from readily available data. The present work shows a comparison of different widely used PTFs to estimate water content at-33 kPa (WR-33kPa) in high stoniness soils. The work was carried out in the Caramacate River, an area of high interest because the frequent landslides worsen the quality of drinking water. The performance of all evaluated PTFs was compared with a PTF generated for the study area. Results showed that the Urach's PTF presented the best performance in relation to the others and could be used to estimate WR-33kPa in soils of Caramacate River basin. The calculated PTFs had a R2 of 0.65. This was slightly higher than the R2 of the Urach's PTF. The inclusion of the rock fragment volume could have the better results. The weak performance of the other PTFs could be related to the fact that the mountain soils of the basin are rich in 2:1 clay and high stoniness, which were not used as independent variables for PTFs to estimate the WR-33kPa.

Robotic assessment of neuromuscular characteristics using musculoskeletal models: A pilot study.

OBJECTIVE: Non-invasive neuromuscular characterization aims to provide greater insight into the effectiveness of existing and emerging rehabilitation therapies by quantifying neuromuscular characteristics relating to force production, muscle viscoelasticity and voluntary neural activation. In this paper, we propose a novel approach to evaluate neuromuscular characteristics, such as muscle fiber stiffness and viscosity, by combining robotic and HD-sEMG measurements with computational musculoskeletal modeling. This pilot study investigates the efficacy of this approach on a healthy population and provides new insight on potential limitations of conventional musculoskeletal models for this application. METHODS: Subject-specific neuromuscular characteristics of the biceps and triceps brachii were evaluated using robot-measured kinetics, kinematics and EMG activity as inputs to a musculoskeletal model. RESULTS: Repeatability experiments in five participants revealed large variability within each subjects evaluated characteristics, with almost all experiencing variation greater than 50% of full scale when repeating the same task. CONCLUSION: The use of robotics and HD-sEMG, in conjunction with musculoskeletal modeling, to quantify neuromuscular characteristics has been explored. Despite the ability to predict joint kinematics with relatively high accuracy, parameter characterization was inconsistent i.e. many parameter combinations gave rise to minimal kinematic error. SIGNIFICANCE: The proposed technique is a novel approach for in vivo neuromuscular characterization and is a step towards the realization of objective in-home robot-assisted rehabilitation. Importantly, the results have confirmed the technical (robot and HD-sEMG) feasibility while highlighting the need to develop new musculoskeletal models and optimization techniques capable of achieving consistent results across a range of dynamic tasks.

Landslides susceptibility change over time according to terrain conditions in a mountain area of the tropic region.

Susceptibility to landslides in mountain areas results from the interaction of various factors related to relief formation and soil development. The assessment of landslide susceptibility has generally taken into account individual events, or it has been aimed at establishing relationships between landslide-inventory maps and maps of environmental factors, without considering that such relationships can change in space and time. In this work, temporal and space changes in landslides were analysed in six different combinations of date and geomorphological conditions, including two different geological units, in a mountainous area in the north-centre of Venezuela, in northern South America. Landslide inventories from different years were compared with a number of environmental factors by means of logistic regression analysis. The resulting equations predicted landslide susceptibility from a range of geomorphometric parameters and a vegetation index, with diverse accuracy, in the study area. The variation of the obtained models and their prediction accuracy between geological units and dates suggests that the complexity of the landslide processes and their explanatory factors changed over space and time in the studied area. This calls into question the use of a single model to evaluate landslide susceptibility over large regions.

Intoxicación por setas: síndrome orellánico / Mushroom poisoning: Orellanus syndrome

No disponible

Malignant rhabdoid tumor of the colon. Report of a case with molecular analysis.

PURPOSE: Malignant rhabdoid tumors were first described in the kidney as a rare variant of Wilms' tumor with a "rhabdomyosarcomatoid" pattern and a particularly poor prognosis. Further studies have demonstrated these neoplasms as a distinct clinicopathologic entity. Subsequently, tumors with a similar histologic appearance, demonstrating the "rhabdoid" cells, have been found in a variety of extrarenal sites. METHODS: We report here a case of malignant rhabdoid tumor of the colon studied with selected molecular techniques. RESULTS AND CONCLUSIONS: This tumor demonstrated several unusual findings for malignant rhabdoid tumors of renal or extrarenal sites, including aneuploidy by flow cytometric analysis and a positive nuclear immunohistochemical staining for p53 protein, which suggests presence of p53 gene mutation. DNA analyses, however, failed to demonstrate the presence of point mutation in any of the ras family genes.

La ultraestructura de leishmania venezuelensis en humanos y gatos naturalmente infectados con leishmaniasis cutánea / The ultrastructure of leishmania venezuelensis in humans and cats naturally infected with cutaneous leishmaniasis

La ultraestructura de la Leishmania venezuelensis en humanos y gatos naturalmente infectados con leishmaniasis cutánea fue similar a la de otras especies conocidas de leishmania que producen enfermedad en humanos. Sin embargo, se observaron algunos hallazgos peculiares, tales como el diámetro promedio, el número y la distancia media entre los microtúbulos peliculares, la presencia de grandes megasomas, el desarrollo de vacuolas fagocíticas gigantes, la dispocisión de los túbulos en el corpúsculo parabasal, la presencia de microtúbulos por debajo de la membrana de la bolsa flagelar y la existencia de una organela excretoria en el polo posterior

Lumbosacral spinal intradural extramedullary paciniomyolipoma: magnetic resonance imaging, computed tomography, and pathology findings.

This report describes a paciniomyolipoma as an intradural tumor of the lumbar spinal cord composed of adipose tissue, striated skeletal muscle, and pacinian corpuscles. Simple lipomas, myolipomas, and other variant lipomas of the spinal cord have been described in the literature; to the authors' knowledge, however, this is the first report of this unusual and unique lipoma.

Características de la desnutrición en niños menores de seis años residentes en zona rural fronteriza / Characteristics of malnutrition in children under six years old residents in a rural frontier zone

Con la finalidad de conocer la incidencia de desnutridos en la clínica rural El Vigiador, Provincia Montecristy, República Dominicana, se realizó un estudio prospectivo, analítico y comparativo con 150 niñoz menores de 6 años de edad, aspirantes a recibir los beneficios del Programa de Alimentación Complementaria Materno Infantil SESPAS-CARE en el período comprendido de enero-julio 1989 de los cuales el 43//tenía criterio de desnutrición. De éstos el mayor procentaje correspondió a los desnutridos grado I con 84.3//. El sexo más afectado fue el femenino con 58.9//. La población más afectada estuvo comprendida en el grupo etareo de 1-2 años de edad con 45.2//. El signo clínico más frecuente fue la pérdida de peso 100//. Desnutrición-zona rural, Clasificación del Dr. F. Gómez, niños, pediatría

Formation of sulphate ion during the dehydration of sulphited vegetables.

A reverse isotope dilution procedure was used to measure the formation of sulphate ion during the air dehydration of sulphited cabbage, carrot and potato at 80 degrees C. The conversion of sulphite to sulphate was found to be of first order with respect to sulphite. The formation of sulphate in the vegetables during dehydration accounts for only part of the sulphate in the dehydrated products; the remainder comes from the scald liquor. The technique for sulphate determination is critically evaluated and the observed yields discussed.

Intravascular tumors: transvenous biopsy.

A technique is described for transfemoral biopsy of intravenous tumors. Positive results were obtained at biopsy in three patients who had an intraluminal mass in the inferior vena cava and in one patient with a mass in the iliac vein. Transvenous biopsy is helpful in obtaining a histologic diagnosis and provides an alternative method to surgery or percutaneous transabdominal needle biopsy.

A case of laboratory acquired Leishmania donovani infection; evidence for primary lymphatic dissemination.

We report the case of a laboratory worker who received close medical follow-up after accidently inoculating her hand with a needle containing a Humera strain of Leishmania donovani amastigotes. She developed a leishmanoma and histologic evidence of local lymphatic dissemination before being treated. The spectrum of disease caused by L. donovani is discussed.

Intranasal presentation of a pituitary adenoma.

Unilateral intranasal polypoidal lesions should always arouse suspicion of unusual pathology. A case of an intranasal extension of a pituitary adenoma is presented. Fourteen other cases that have been reported in the literature are summarized and modalities of treatment of this entity are briefly discussed.

Circulation, bone scans, and tetracycline labeling in microvascularized and vascular bundle implanted rib grafts.

The circulation in microvascularized rib grafts has been compared with that in conventional rib grafts and in those augmented by a direct vascular bundle implantation into the bone grafts. A new experimental model has been designed to correlate vascular perfusion, bone scan patterns, tetracycline labeling, and histological findings in these bone grafts. Posterior microvascularized rib grafts were found to have a circulatory pattern identical to that of the normal rib. Failed microvascularized rib grafts were revascularized more slowly than conventional rib grafts. Vascular bundles implanted into rib grafts remained patent and increased the rate of revascularization. The stripping or preservation of periosteum had no observable effects on the rate or pattern of conventional rib graft revascularization. The circulation in rib grafts was accurately reflected in technetium 99 bone scans, as was the patency of the anastomoses of microvascularized rib grafts and of implanted vascular bundles. In contrast, tetracycline labeling was repeatedly observed in avascular areas of bone grafts and, therefore, is not a reliable indicator of bone graft circulation.

Undifferentiated carcinoma with lymphoid stroma of the parotid gland.

Six cases of undifferentiated carcinoma of the parotid gland with heavy lymphocytic infiltration have been treated at Montreal General Hospital over the past 23 years. A thorough review of the literature revealed another 31 similar cases which are discussed. For unknown reasons, these malignant tumors seem to be more common in North American Inuit. Their relatively better prognosis may be attributed to the protective function of the heavy lymphocytic infiltration. Surgery has been the treatment of choice with postoperative radiotherapy in indicated cases. Longer follow-up is necessary to assess the role of lymphocytic infiltration in improving survival.