Análisis de la competitividad del sistema extensivo de producción ovina de pequeña escala en el sureste hidalguense.

The objective of this study was to evaluate the comparative advantage of grazing in the competitiveness of the small-scale sheep production system in Singuilucan, Hidalgo, Mexico. For this purpose, data from 51 production units were analyzed, chosen from a simple random sampling. The information was obtained through an interview with 120 questions, organized into technical variables, economic aspects and social aspects of the producer. The Policy Analysis Matrix (PAM) was used to analyze the impact of grazing on competitiveness, in two scenarios: in the first, the low cost structure was studied under the traditional form of production, which uses grazing as feeding basis; while in the second, the cost was simulated by counting the purchase of feed, as well as hiring workforce. The results revealed that grazing as a feeding basis (real scenario), instead of commercial feed (simulated scenario), increases the profitability of the sheep system in 53%, which translates into a cost reduction (32%) and an increase in the utility of $10,830 (ten thousand eight hundred thirty pesos per farm) for each productive cycle of four months. The high dependency on grazing and family workforce observed in the simulated scenario indicate that the small-scale sheep production in Singuilucan could be vulnerable, if the micro-regional advantages that these factors contribute were to be lost, which would translate into a competitive reduction of approximately 62$10,830 (diez mil ochocientos treinta pesos promedio por granja) por cada ciclo productivo de cuatro meses. La alta dependencia del pastoreo y mano de obra familiar observada en el escenario simulado, indican que la producción ovina de pequeña escala en Singuilucan, podría ser vulnerable, si perdiera las ventajas microregionales que le aportan estos factores, lo cual, se traduciría en una reducción competitiva de aproximadamente 62%

Terminal interruption of relux source technique in the treatment of active venous ulcers

Introduction: The treatment for venous ulcers in most cases is unsatisfactory, with recurrences and poor healing. Objective: to evaluate adjuvant therapy in the treatment of active venous ulcers. Methods: We analyzed 20 patients with active venous ulcers attending the general Surgery outpatient clinic at the “Dr. José eleuterio gonzález” University Hospital from October 2012 to January 2013. they were randomly divided into 2 groups: group A (11 patients) underwent compression therapy and group B (9 patients) underwent compression therapy plus removal of the vein that gives terminal relux to the ulcer, guided by ultrasound (microphlebectomy). Patients were evaluated weekly (8 weeks). At each assessment, photographs and lesion measurements were taken and pain was evaluated using the visual analog scale. Results: No significant differences were found between the study groups in terms of age, weight, height, body mass index (BMi), ankle-brachial index, and baseline measurement of the ulcer (p>0.05). Group B showed a greater reduction in ulcer size and a statistically signiicant lower score on the visual analog pain scale (p<0.05) from the second and third week of treatment, respectively. Conclusions: the results obtained in patients with surgical procedure (group B) are consistent with the reported eficacy of chronic venous ulcer treatment with saphenectomy (conventional surgery), the difference is that in this study we used a minimally invasive procedure (microphlebectomy)

Surgical treatment of a pseudoaneurysm of the femoral artery secondary to a gunshot wound: clinical case report

We report a case of a 18-year-old male patient with a diagnosis of pseudoaneurysm of the right supericial femoral artery secondary to penetrating injury by gunshot, which was treated in our Hospital with an aneurysm resection and a saphenous vascular graft inverted with a satisfactory evolution

Reporte de caso: oclusión y necrosis intestinal por hernia del obturador

Antecedentes: La hernia del obturador es una causa infrecuente de hernias de la pared abdominal que comprende del 0.07 al 1% de todas las hernias y se presenta con mayor frecuencia en mujeres de edad avanzada y multíparas. Caso clínico: Femenino de 78 anos ˜ de edad, sin antecedentes médicos de importancia, que inicia 7 días previos a su ingreso con intolerancia a la vía oral, náuseas y vómito; se agrega ausencia de canalización de gases y evacuaciones, por lo que acude a urgencias. Se le realiza tomografía computada de abdomen simple y se observa distensión de asas de intestino delgado y niveles hidroaéreos proximales a una hernia del agujero obturador conformado por un asa de intestino delgado localizada entre el músculo pectíneo y el obturador externo; se realiza una laparotomía exploradora encontrando hernia del agujero obturador de intestino delgado a 130 cm del ángulo de Treitz, con necrosis de intestino delgado, sin perforación; se realizan resección intestinal de 10 cm de yeyuno, entero enteroanastomosis término terminal en 2 planos y cierre primario del defecto. Conclusión: La hernia del obturador no es una causa frecuente de oclusión intestinal; sin embargo, hay que tomarla en cuenta como una causa de la misma, sobre todo en pacientes de sexo femenino, edad avanzada y multíparas, para hacer un diagnóstico pertinente y evitar la isquemia intestinal. ABSTRAC Background: Obturator hernia is a rare variety of abdominal hernia, it accounts for 0.07%---1.0%of all hernias, and occurs most often in women of advanced age and multiparous. Clinical case: A 78-year-old female was admitted to the Emergency Department due to nausea, vomiting, complaints of abdominal discomfort and obstipation for the last 7 days. Abdominal CT scan showed dilated small bowel loops and multiple air-fluid levels near to a small bowel loop obturator hernia, between external obturator and pectineus muscle. Emergency laparotomy was performed and during the surgery, loop of small intestine was revealed herniated into the obturator foramen, 130 cm from the angle of Treitz. Necrosis of small intestine was found, without perforation. Resection of the 10 cm affected jejunal segment was performed and a side-to-side bowel anastomosis was fashioned. Also simple suture closure of obturator foramen was performed. Conclusion: Obturator hernia is relatively rare. However physicians should keep it in mind and have clinical suspicion for obturator hernia as a cause of intestinal obstruction in female, elderly and multiparous patients in order to make an appropriate diagnosis and avoid bowel ischaemia

Reparación quirúrgica vascular de arteria carótida común derecha por lesión de proyectil de arma de fuego

Las lesiones penetrantes de la arteria carótida común son poco frecuentes, pero de alta morbimortalidad. En los últimos 10 anos ˜ se ha registrado un aumento importante de este tipo de lesiones en nuestro medio debido a la delincuencia organizada, resultando un reto para el cirujano general de hospitales que no cuentan con cirujano cardiovascular. Es de vital importancia conocer el manejo óptimo de este tipo de lesiones, así como el diagnóstico oportuno tanto de las que precisen tratamiento quirúrgico abierto urgente como de las que tras estudios complementarios puedan derivarse a tratamiento conservador o intravascular. Presentamos un caso de lesión aislada de arteria carótida común derecha por proyectil de arma de fuego tratada por el servicio de Cirugía General con exploración vascular cervical y resección de segmento afectado con anastomosis término-terminal en un hospital de tercer nivel del noreste de Méxic

Resección hepática en niños. Diez años de experiencia

Se revisó la experiencia obtenida en 11 resecciones hepáticas hechas en niños en los últimos 10 años. Se investigaron los datos clínicos y los resultados de los estudios de gabinete y laboratorio. Se describe la técnica quirúrgica empleada y las variedades histológicas encontradas; entre las que el hepatoblastoma fue la frecuente. No hubo ningún deceso relacionado con el acto quirúrgico

Análisis de costos y estrategias productivas en la lechería de pequeña escala en el periodo 2000-2012

Se analizó contablemente la evolución y desempeño de las estrategias productivas, económicas y comerciales utilizadas por productores lecheros de pequeña escala en la zona periurbana de Texcoco, México. Para tal motivo, los datos económicos y productivos fueron obtenidos de 1 023 lactancias en el periodo 2000-2012. Se utilizó la metodología general de costos para establecer las estructuras contables de los sistemas de producción y la metodología financiera de reajustabilidad de valores mediante la construcción de deflactores usando la variación del Índice Nacional de Precios al Consumidor. Se presenta evidencia que entre los periodos analizados el grupo de productores, ubicado en el estrato I, definió como estrategias una nula participación de mano de obra eventual y contratada, así como la independencia en la compra de insumos (ya que este estrato produce 90% de sus insumos); el estrato II disminuyó tres de los cuatro principales rubros del costo total de producción (alimentación, medicamentos y servicio reproductivo) e incrementó la utilidad promedio por litro de leche ($2.00) con estrategias comerciales de venta; el estrato III definió como estrategias el aumento de productividad (59%), la disminución en costo (29%) del principal insumo (alimento) en la dieta y el aprovechamiento de la escala productiva para obtener la mayor entrada de ingresos por unidad productiva

Análisis de costos y estrategias productivas en la lechería de pequeña escala en el periodo 2000-2012

An accounting analysis was performed on the evolution and performance of productive, economic and marketing strategies implemented by small-scale dairy farmers in the peri-urban area of Texcoco, Mexico. Economic and production records for 1 023 lactation were obtained in two periods, 2000 and 2012. The general cost methodology was used to establish the accounting structures of these production systems, and the re-adjustment of values financial methodology through calculating deflated values based on data from the Mexican National Index of Consumer Prices. Evidence is presented that farmers in Stratum I defined as strategies not hiring temporary or permanent labour, as well as independence in the purchase of inputs (this Stratum produces 90% of its inputs). Stratum II reduced 3 of the main 4 items of the total production cost (feeding, medicines and breeding) and increased the mean profit per litre of milk ($2.00 MXN) through selling strategies. Stratum III defined as their strategies increased productivity (59$2.00) con estrategias comerciales de venta; el estrato III definió como estrategias el aumento de productividad (59%), la disminución en costo (29%) del principal insumo (alimento) en la dieta y el aprovechamiento de la escala productiva para obtener la mayor entrada de ingresos por unidad productiva

Development of Low-Alloyed Low-Carbon Multiphase Steels under Conditions Similar to Those Used in Continuous Annealing and Galvanizing Lines

In the present work, a Cr+Mo+Si low-alloyed low-carbon steel was fabricated at laboratory scale and processed to produce multiphase advanced high-strength steels (AHSS), under thermal cycles similar to those used in a continuous annealing and galvanizing process. Cold-rolled steel samples with a microstructure constituted of pearlite, bainite, and martensite in a matrix ferrite, were subjected to an intercritical annealing (817.5 &deg;C, 15 s) and further isothermal bainitic treatment (IBT) to investigate the effects of time (30 s, 60 s, and 120 s) and temperature (425 &deg;C, 450 &deg;C, and 475 &deg;C) on the resulting microstructure and mechanical properties. Results of an in situ phase transformation analysis show that annealing in the two-phase region leads to a microstructure of ferrite + austenite; the latter transforms, on cooling to IBT, to pro-eutectoid ferrite and bainite, and the austenite-to-bainite transformation advanced during IBT holding. On final cooling to room temperature, austenite transforms to martensite, but a small amount is also retained in the microstructure. Samples with the lowest temperature and largest IBT time resulted in the highest ultimate tensile strength/ductility ratio (1230.6 MPa-16.0%), which allows to classify the steel within the third generation of AHSS. The results were related to the presence of retained austenite with appropriate stability against mechanically induced martensitic transformation

Using Intercritical CCT Diagrams and Multiple Linear Regression for the Development of Low-Alloyed Advanced High-Strength Steels

The present work presents a theoretical and experimental study regarding the microstructure, phase transformations and mechanical properties of advanced high-strength steels (AHSS) of third generation produced by thermal cycles similar than those used in a continuous annealing and galvanizing (CAG) process. The evolution of microstructure and phase transformations were discussed from the behavior of intercritical continuous cooling transformation diagrams calculated with the software JMatPro, and further characterization of the steel by scanning electron microscopy, optical microscopy and dilatometry. Mechanical properties were estimated with a mathematical model obtained as a function of the alloying elements concentrations by multiple linear regression, and then compared to the experimental mechanical properties determined by uniaxial tensile tests. It was found that AHSS of third generation can be obtained by thermal cycles simulating CAG lines through modifications in chemistry of a commercial AISI-1015 steel, having an ultimate tensile strength of UTS = 1020–1080 MPa and an elongation to fracture of Ef = 21.5–25.3%, and microstructures consisting of a mixture of ferrite phase, bainite microconstituent and retained austenite/martensite islands. The determination coefficient obtained by multiple linear regression for UTS and Ef was R2 = 0.94 and R2 = 0.84, respectively. In addition, the percentage error for UTS and Ef was 2.45–7.87% and 1.18–16.27%, respectively. Therefore, the proposed model can be used with a good approximation for the prediction of mechanical properties of low-alloyed AHSS