387 research outputs found

    ECOLOGÍA Y SITUACIÓN ACTUAL DE LA FAMILIA COLUMBIDAE EN LA RESERVA DE LA BIOSFERA LOS TUXTLAS, VERACRUZ

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    RESUMEN Analizamos la presencia y abundancia de palomas tropicales residentes en la Reserva de la Biosfera Los Tuxtlas, Veracruz, México durante las épocas reproductivas de 2010 y 2011. Se emplearon distintos métodos de conteo para maximizar el registro del mayor número de especies y superar las dificultades del terreno y la vegetación. Muestreamos principalmente a través de transectos y puntos de conteo en bosque tropical perennifolio, bosque mesófilo de montaña, bosque de pino‐encino y áreas agropecuarias, y registramos 512 individuos de 12 de las 17 especies reportadas históricamente. Las especies registradas en el presente fueron: Patagioenas cayennensis, P. speciosa, P. flavirostris, P. nigrirostris, Columbina inca, C. talpacoti, Claravis pretiosa, Geotrygon montana, Leptotila verreauxi, L. plumbeiceps, Zentrygon carrikeri (endémica) y Zenaida asiatica. La mayor riqueza se observó en el bosque tropical perennifolio, en donde la especie más abundante fue L. verreauxi. La abundancia varió significativamente entre tipos de vegetación para L. verreauxi, L. plumbeiceps y Z. carrikeri, posiblemente debido a los diferentes niveles de tolerancia a la perturbación. El bosque mesófilo de montaña fue el hábitat utilizado en mayor proporción a lo esperado para la mayoría de las especies examinadas como: P. flavirostris, C. pretiosa, L. verreauxi, L. plumbeiceps y Z. carrikeri. Las preferencias de hábitat más amplias correspondieron a P. flavirostris, C. pretiosa y L. verreauxi. Tres especies fueron exclusivas a un tipo de vegetación (P. cayennensis y P. nigrirostris en bosque tropical perennifolio; P. speciosa en bosque mesófilo de montaña). El volcán San Martín Pajapan, una de las áreas núcleo de la Reserva de la Biósfera fue muestreada por primera vez, y registramos a L. verreauxi, L. plumbeiceps, al igual que a una importante población de Z. carrikeri, especie endémica cuyas poblaciones conocidas están limitadas a otras tres áreas montañosas de la región. Las poblaciones de palomas que habitan en interior de bosque se encuentran ubicadas en fragmentos de bosque primario aislados, por lo que deben establecerse corredores para evitar el aislamiento de las poblaciones remanentes de especies de palomas en riesgo. ABSTRACT ∙ Ecology and status of pigeons and doves (Columbidae) in Los Tuxtlas Biosphere Reserve, Veracruz, MexicoWe analyzed the presence and abundance of tropical resident pigeons and doves (Columbidae) in Los Tuxtlas Biosphere Reserve, Veracruz, Mexico, during the breeding seasons of 2010 and 2011. We used different survey methods to maximize the detection of different species and overcome terrain and vegetation limitations. We surveyed the area mostly through transects and point counts in evergreen tropical forest, cloud forest, pine‐oak forest, and agricultural areas, including the Reserve core areas, recording 512 individuals of 12 out of 17 columbid species reported historically for the area. We were able to confirm Patagioenas cayennensis, P. speciosa, P. flavirostris, P. nigrirostris, Columbina inca, C. talpacoti, Claravis pretiosa, Geotrygon montana, Leptotila verreauxi, L. plumbeiceps, Zentrygon carrikeri (endemic), and Zenaida asiatica. The tropical evergreen forest is the vegetation type with the highest species richness, and the most abundant species was L. verreauxi. Abundance varied significantly among vegetation types for L. verreauxi, L. plumbeiceps, and Zentrygon carrikeri, possibly due to differences in their tolerance to disturbance. Cloud forest stood out as the most important habitat as it was used more than expected by species such as P. flavirostris, C. pretiosa, L. verreauxi, L. plumbeiceps, and Z. carrikeri. The species with the broadest habitat preferences were P. flavirostris, C. pretiosa, and L. verreauxi. Three species were exclusive to a single vegetation type (P. cayennensis and P. nigrirostris to evergreen tropical forest; P. speciosa to cloud forest). The volcán San Martín Pajapan, one of the Bio‐ sphere Reserve core areas was surveyed for the first time, and we recorded L. verreauxi, L. plumbeiceps, as well as an important population of Z. carrikeri, the latter endemic species being previously only known from three other Mexican mountain ranges. The populations of doves and pigeons inhabiting the forest interior are mostly located in isolated primary forest fragments, therefore corridors should be established to avoid the isolation of the remaining endangered dove populations

    Micofagia bacteriana.

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    Transformación genética de olivo con el gen OeHPL para el análisis funcional del papel de la enzima 13-hidroperóxido liasa (13-HPL) en la producción de compuestos volátiles.

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    La 13-hidroperóxido liasa es una enzima implicada en la biosíntesis de compues- tos volátiles y tiene un papel fundamental sobre la composición y propiedades del aceite de oliva virgen. La expresión del gen OeHPL muestra una regulación temporal durante la maduración y desarrollo del fruto; además, la expresión es alta en hojas y tejido de mesocarpo y baja en semillas. En este trabajo se aborda el análisis funcional de este gen mediante su sobreexpresión y silenciamiento en plantas transgénicas de olivo. La transformación se llevó a cabo vía Agrobac- terium. Se utilizó la cepa AGL-1 con tres construcciones distintas: pHPLs para sobreexpresión (orientación sentido), pHPLas (orientación antisentido) y pHPLi (ARN-interferente) para silenciamiento. Se recuperaron plantas procedentes de 27 líneas transgénicas independientes, 6 HPLs, 10 HPLas y 11 HPLi. El análisis de la expresión del gen OeHPL en hojas de estas líneas mostró los siguientes resultados, a) líneas sentido: en una de ellas aumentó la expresión 24 veces mien- tras que en otras tres, aumentó en el rango 4-7X; b) líneas antisentido: sólo en dos de ellas disminuyó su expresión un 20% y c) líneas RNAi: en tres de ellas, se redujo la expresión entre 25-35% mientras que en otras dos, disminuyó un 50%. Estas líneas RNAi muestran un crecimiento ralentizado y, en general, presen- tan menor vigor que las controles. Próximamente, se iniciarán los trabajos para cuantificar la actividad enzimática 13-HPL y el contenido de volátiles en hojas con diferentes perfiles de expresión del gen. Asimismo, dado el papel que los vo- látiles de hoja verde, formados vía HPL, juegan en la resistencia a estrés también se evaluará la tolerancia a verticilosis en las plantas de las líneas seleccionadas.Universidad de Málaga. Campus de Excelencia Internacional Andalucia Tech

    Synthesis of Nylon 6/Modified Carbon Black Nanocomposites for Application in Uric Acid Adsorption

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    High uric acid levels cause different clinic conditions. One of them is hyperuricemia, which leads to kidney damage. A solution for eliminating uric acid in the blood is by hemodialysis, which is performed using nanocomposite membranes. In this work, Nylon 6 nanocomposites were synthesized with modified carbon black (MCB), which were considered candidate materials for hemodialysis membranes. The modification of carbon black was made with citric acid using the variable-frequency ultrasound method. The new MCB was characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray diffraction (XRD), transmission electron microscopy (TEM), and dispersion tests. Nylon 6/MCB nanocomposites were processed using the ultrasound-assisted melt-extrusion method to improve the dispersion procedure of the nanoparticles. The Nylon 6/MCB nanocomposites were characterized by FTIR, TGA, and differential scanning calorimetry (DSC). These were assessed for the absorption of toxins and hemocompatibility. MBC and nanocomposites showed excellent uric acid removal (78–82%) and hemocompatibility (1.6–1.8%). These results suggest that Nylon 6/MCB nanocomposites with low loading percentages can be used on a large scale without compatibility problems with blood

    Xanthogranulomatous pyelonephritis: a review

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    Xanthogranulomatous pyelonephritis (XP), first described in 1916, is a rare form of chronic granulomatous inflammation. The etiology is still unclear; however, the development of the disease is associated with chronic urinary obstruction secondary to lithiasis, tumors and urological malformations, among others. This leads to the destruction of the renal parenchyma and its replacement by solid sheets of lipid-laden macrophages. Female gender, diabetes and obesity are attributed as predisposing factors to the development of XP. It is estimated that the incidence presents a maximum peak between 50 and 70 years, with a ratio of 2:1 women-men respectively. Computed tomography (CT) is described as the mainstay in the evaluation. However, the definitive diagnosis is made by histopathological study, where a mixture of lipid-laden foamy macrophages, lymphocytes, neutrophils, giant cells, and plasma cells can be seen. Nephrectomy (open or laparoscopic) continues to be the first-line treatment. The laparoscopic approach is associated with an increase in operating time; however, the recovery time is shorter compared to the open approach. Given the natural history of the disease and the associated complications, this makes it a challenging approach for the surgeon. Therefore, a surgeon experienced in laparoscopic skills is necessary. This review seeks to synthesize existing information regarding the appropriate surgical approach in conjunction with the clinical context

    Hypospadias: a review

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    Hypospadias is a congenital malformation of the male external genitalia, which includes: anomalous location proximal to the urethral meatus, in any portion of the glans penis and perineum, hooded dorsal foreskin, and inverted penile curvature on the dorsal side of the foreskin. The etiology has been considered multifactorial, secondary to the interaction of environmental factors with specific genetic background. It represents the second most frequent congenital defect in male newborns. It has increasing prevalence rates of 0.25 new cases per 10,000 newborns per year. Risk factors that have been identified include infants small for gestational age with weight below the 10th percentile, head length and/or circumference, intrauterine growth restriction, and placental insufficiency. Regarding environmental risk factors, maternal exposure to pesticides has been linked. Prenatal diagnosis has been described, however proximal hypospadias is usually detected, making it difficult to diagnose distal hypospadias using this method. So usually the diagnosis is made after birth during the physical examination. To date, more than 300 surgical techniques are known for the correction of hypospadias. The treatment of distal hypospadias is currently performed in one time; the management of proximal hypospadias is controversial; one group favors the one-stage procedure, while other groups choose to perform the two-stage procedure

    Staghorn renal stones: a review

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    Staghorn lithiasis is described as the presence of stones in the urinary tract that create a mold of the renal collecting system, with the characteristic of being branched. It has a strong association with urinary tract infections caused by urea-splitting organisms. The composition of the stone usually consists of pure magnesium ammonium phosphate (struvite), or a mixture of struvite and calcium carbonate apatite. It is classified as complete and partial. In the complete one, the stones occupy the renal pelvis and the calyceal system, or more than 80% of the collecting system; unlike the partial ones that occupy the renal pelvis and at least two calyces. Computed tomography without intravenous contrast is the imaging method of choice for diagnosis and planning of surgical intervention. Allowing an accurate assessment of the morphology and location of the stones; that will set the standard for guiding percutaneous access. Complete stone cleaning is the cornerstone of staghorn lithiasis treatment. The guidelines of the European Association of Urology and the American Association of Urology mention that percutaneous nephrolithotomy continues to be the treatment of choice for large stones. Conservative management is related to renal loss and urosepsis, reporting a mortality of 28 % up to 30% within 10 years, as well as a 36% risk of developing chronic kidney disease

    Pseudoaneurysm due to femoral artery puncture: a review

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    The femoral artery is the most used percutaneous access site for different endovascular therapeutic options, this being an excellent anatomical site to achieve adequate compression after its puncture, which frequently makes it the site with the highest incidence of complications associated with posterior to arterial puncture. The most frequent complications related to arterial puncture are: hematoma, pseudoaneurysm, retroperitoneal hematoma, and arterial occlusion. The pseudoaneurysm is defined as the interruption in the wall of the artery, product of the lesion of the wall, which causes blood leakage towards the surrounding tissues, remaining contained in a fibrin sac, therefore, the importance of an adequate diagnosis and treatment lies above all in the high risk of rupture or thromboembolism.

    Biliary atresia: a review

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    Bile duct atresia (BA) is a severe, progressive cholangiopathy characterized by fibrous and inflammatory obliteration of the intrahepatic and extrahepatic bile ducts. It leads to liver failure, scarring, and end-stage cirrhosis if timely treatment is not achieved. It represents the number one indication for pediatric liver transplantation as a single disease worldwide. Various etiological factors have been associated with BA, such as structural malformations, viral, immune-mediated, and genetic infections. The incidence of BA varies around the world. Untreated BA patients have a 2-year mortality of nearly 100%. The clinical picture is characterized by jaundice, acholia, and jaundice that persists beyond the first 2 weeks of life. Direct or conjugated bilirubin remains the primary screening laboratory test for BA; elevated values ​​occur within the first 2 days of life. Currently, the primary treatment of choice is the Kasai portoenterostomy; the success of surgery has been based on the restoration of bile flow and the elimination of jaundice. However, more than 70% of patients develop liver cirrhosis secondary to persistent liver inflammation, which will require liver transplantation. The following review of the literature aims to collect relevant information from what has been published in recent years on bile duct atresia; focused on the study of etiology, pathophysiology, advances in genetics and immunology. As well as the results associated with surgical treatment and the requirement for liver transplantation

    Biodegradable electrospun scaffolds for skin wound regeneration: a review

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    Over the years, skin substitutes have been sought as an alternative for the treatment of different pathologies. In this article, we focus on describing the use of different biodegradable nanofibrillar polymers as skin substitutes in the treatment of acute and chronic wounds, obtained by the electrospinning technique. Electrospinning is a tissue engineering technique used to generate nanofibers of different polymers that are characterized by having a high surface area, low molecular weight, high resistance rates, and nanoporosity, which is why they are particularly interesting for biomedicine, with potential applicability. in the replacement of skin and tubular organs. In this context, the skin created by tissue engineering has high expectations of application in the study of treatment of skin wounds
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