Ant Communities along a Gradient of Plant Succession in Mexican Tropical Coastal Dunes

Most of Mexican coastal dunes from the Gulf of Mexico have been severely disturbed by human activities. In the state of Veracruz, the La Mancha Reserve is a very well preserved coastal community of sand dunes, where plant successional gradients are determined by topography. In this study we assessed species richness, diversity and faunal composition of ant assemblages in four plant physiognomies along a gradient of plant succession: grassland, shrub, deciduous forest and subdeciduous forest. Using standardized and non-standardized sampling methods we found a total of 121 ant species distributed in 41 genera and seven subfamilies. Grassland was the poorest site (21 species) and subdeciduous forest the richest (102 species). Seven species, with records in ≥10% of samples, accounted 40.8% of total species occurrences: Solenopsis molesta (21.6%), S. geminata (19.5%), Azteca velox (14%), Brachymyrmex sp. 1LM (11.7%), Dorymyrmex bicolor (11.2%), Camponotus planatus (11%) and Pheidole susannae (10.7%). Faunal composition between sites was highly different. Nearly 40% of all species were found in a single site. In all sites but grassland we found high abundances of several species typical of disturbed ecosystems, indicating high levels of disturbance. A species similarity analysis clustered forests in one group and grassland and shrub in another, both groups separated by more than 60% of dissimilarity. Similarity of ant assemblages suggests that deciduous and subdeciduous forests represent advanced stages of two different and independent successional paths

El crecimiento económico colombiano: datos nuevos y modelos viejos para interpretar el período 1925-2000

En este documento presentamos y utilizamos una base de datos demográficos y macroeconómicos colombianos del período 1925-2000. Del examen de estos datos sobresalen algunos rasgos interesantes. Entre estos se destacan la transición demográfica, iniciada a mediados del siglo XX, y las desaceleraciones de las tasas de crecimiento del capital humano, de los productos por trabajador y por habitante y de la productividad multifactorial en el último cuarto del siglo. Además, bajo ciertos supuestos calculamos: a) la brecha entre la tasa de inversión en capital físico y la tasa teórica de ahorro de equilibrio (según el modelo de Solow), b) el nivel de equilibrio de la tasa de rendimiento real del capital físico de estado estacionario, c) el salario real integral de equilibrio del año 2000 y d) los acervos de los capitales humano y total.Población, tasas de natalidad y mortalidad, crecimiento económico, capital humano, productividad multifactorial, eficiencia laboral. Classification JEL: J11; J24; O11; O16; O40; O47

Validez de la prueba de histerectomía vaginal en pacientes con indicación de vía abdominal mandatoria

Indexación: ScieloObjetivo: Evaluar la histerectomía vaginal en la resolución de patología uterina benigna, en casos que habitualmente se resuelven por histerectomía abdominal. Método: Estudio prospectivo en 68 pacientes sometidas a histerectomía vaginal en el Servicio de Ginecología del Hospital Claudio Vicuña, de San Antonio, entre junio de 2003 a junio de 2009. Son pacientes sin partos vaginales, algunas nuligestas, la mayoría con cicatrices de cesárea o historia de cirugía pélvica previa. Se separan en dos grupos, uno de dificultad moderada (DM) (útero móvil, vagina >2 dedos de diámetro, fondos de saco bien conformados) y otro de dificultad severa (DS) (útero fjo, vagina 2 fingers diameter, well conserved cul de sac, and severe difficulty (SD): composed by patients with none uterine motility, vagina <2 fingers diameter or fat cul de sac. Results: We did not observed statistically significant differences in age, number of prior cesarean sections or pelvic surgeries, estimated uterine size, bladder injury, nor abdominal conversion, but there was significant differences in operative time and need of morcelation, being greater in SD patients. It is important to notice the absent of major and minor complications in 93% of the patients. Conclusion: Our results are meant to demystify the objections for vaginal route, including the patients with extreme difficulty.http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-75262010000500008&nrm=is

Índices de escasez y de calidad del agua para la priorización de cuerpos de agua en los planes de ordenación del recurso hídrico. Aplicación en la jurisdicción de CORANTIOQUIA

En el marco de la formulación del Plan de Ordenamiento del Recurso Hídrico(PORH) para las direcciones territoriales Tahamíes y Zenufaná de la jurisdicción deCORANTIOQUIA (Corporación Autónoma Regional del Centro de Antioquia), sehizo la priorización de corrientes a partir del índice de calidad del agua y del índicede escasez, para corrientes receptoras de vertimientos y para corrientes abastecedorasde agua de suministro. Se presentan los resultados obtenidos para las 22 corrientesabastecedoras evaluadas a través del índice de escasez, y 39 corrientes receptoras devertimientos evaluadas, mediante el índice de calidad del agua. Estos resultadossirvieron como base para la definición de medidas de manejo del recurso hídrico

Using Native Plants of the Northeast of Mexico for Developing Active Antimicrobial Food Packaging Films

The development of active food packaging is addressed using polyolefins such as LDPE and PVOH, as well as biopolymers from flour (sorghum and corn) and by-products of the food industry. Bacteriocins (nisin, natamycin), plant extracts such as oregano and thyme, as well as native plants of the northeast region of Mexico (Larrea tridentata, Schinus molle, Cordia boissieri, Leucophyllum frutescens), and essential oils of oregano and thyme as antimicrobial agents have been studied. The effect exerted by the process of incorporation of the antimicrobial agent (casting, extrusion) on the barrier and mechanical properties of the package as well as the antimicrobial activity of the containers (broad spectrum or selective activity) has been observed and the establishment of methods for their traceability

Rewiring of auxin signaling under persistent shade

Pucciariello, Ornella. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura (IFEVA). Buenos Aires, Argentina.Legris, Martina. CONICET. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires. Buenos Aires, Argentina.Costigliolo Rojas, Cecilia. CONICET. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires. Buenos Aires, Argentina.Iglesias, María José. CONICET. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires. Buenos Aires, Argentina.Hernando, Carlos Esteban. CONICET. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires. Buenos Aires, Argentina.Dezar, Carlos. Instituto de Agrobiotecnología de Rosario. Rosario, Argentina.Vazquez, Martín P. Instituto de Agrobiotecnología de Rosario. Rosario, Argentina.Casal, Jorge José. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura (IFEVA). Buenos Aires, Argentina.5612-5617Light cues from neighboring vegetation rapidly initiate plant shade - avoidance responses. Despite our detailed knowledge of the early steps of this response, the molecular events under prolonged shade are largely unclear. Here we show that persistent neighbor cues reinforce growth responses in addition to promoting auxin - responsive gene expression in Arabidopsis and soybean. However, while the elevation of auxin levels is well established as an early event, in Arabidopsis, the response to prolonged shade occurs when auxin levels have declined to the prestimulation values. Remarkably, the sustained low activity of phytochrome B under prolonged shade led to (i) decreased levels of PHYTOCHROME INTERACTING FACTOR 4 (PIF4) in the cotyledons (the organs that supply auxin) along with increased levels in the vascular tissues of the stem, (ii) elevated expression of the PIF4 targets INDOLE-3-ACETIC ACID 19 (IAA19) and IAA29, which in turn reduced the expression of the growth-repressive IAA17 regulator, (iii) reduced abundance of AUXIN RESPONSE FACTOR 6, (iv) reduced expression of MIR393 and increased abundance of its targets, the auxin receptors, and (v) elevated auxin signaling as indicated by molecular markers. Mathematical and genetic analyses support the physiological role of this system - level rearrangement. We propose that prolonged shade rewires the connectivity between light and auxin signaling to sustain shade avoidance without enhanced auxin levels

Una valoración histórica de las particularidades de los expedientes judiciales concernientes a la Guerra de los Mil Días

This paper was made as a complement of digitizing of judicial files relatingto Thousand Days War(Guerra de los Mil Días). In order to further the research viewpoint about the strategies and actions of peopleclasses among this war, the paper examines those exertions thatscholars have developed in that way. In connection with that, it goes into the discussion aboutthe sources for this kind of researches, holding that the favour about the official sources has obscured the sight toward the comprehension of the experiences of common people when the war erupts over their life

Imágenes de resonancia magnética en el diagnóstico diferencial de las lesiones hepáticas más frecuentes

ResumenLa resonancia de h&iacute;gado ha ganado un papel importante en el diagn&oacute;stico y caracterizaci&oacute;n de las lesiones hep&aacute;ticas dados los avances tecnol&oacute;gicos que han disminuido el tiempo de adquisici&oacute;n de las im&aacute;genes, a m&aacute;s de la utilizaci&oacute;n de nuevas secuencias y de gadolinio, los que aporta datos sobre la vascularizaci&oacute;n. Losquistes y los hamartomas de la v&iacute;a biliar son hipointensos en T1 e hiperintensos en T2; se diferencian porque los &uacute;ltimos presentan un anillo delgado de captaci&oacute;n de gadolinio. Los hemangiomas, m&aacute;s comunes en mujeres, son hipointensos en T1 y moderadamente hiperintensos en T2, con un realce centr&iacute;peto en la fase arterial.La hiperplasia nodular focales es iso a levemente hipointensa en T1 e iso a levemente hiperintensa en T2, capta intensamente el medio en la fase arterial, tienen una cicatriz central que en las fases tard&iacute;as llega a ser isointensa a levemente hiperintensa. Los adenomas son moderadamente hipointensos en T1 e isointensos alevemente hiperintensos en T2, tienen realce marcado en la fase arterial pero desaparece en la fase venosa y tard&iacute;a, persistiendo un anillo de realce. Los n&oacute;dulos de regeneraci&oacute;n son isointensos en T1 e iso a hipointensos en T2, los n&oacute;dulos displ&aacute;sicos son hiperintensos en T1 e iso a hipointensos en T2, diferenci&aacute;ndose delcarcinoma hepatocelular porque generalmente son menores de 2 cm y el carcinoma presenta realce marcado y heterog&eacute;neo del contraste en la fase arterial.[Lubinus FG, Rojas SP, Salcedo CJ. Resonancia magn&eacute;tica del h&iacute;gado. MedUNAB 2006; 9: 145-150].Palabras clave: Quistes, Hamartomas biliares, Hemangiomas, Hiperplasia nodular focal, Adenomas, N&oacute;dulos de regeneraci&oacute;n, N&oacute;dulos displ&aacute;sicos, Carcinoma hepatocelular, Gadolinio

Malrotación intestinal como causa de dolor abdominal en adultos. Revisión de un caso.

ResumenSe presenta el caso de una paciente de 63 a&ntilde;os con dolor abdominal cr&oacute;nico y v&oacute;mito bilioso, hospitalizada por cuadro seudoobstructivo intestinal que cede al tratamiento m&eacute;dico, se le solicita tomograf&iacute;a axial computarizada (TAC) abdominal observ&aacute;ndose unamalrotac&aacute;&oacute;n &aacute;ntest&aacute;nalI la cual es conf&aacute;rmada &eacute;or med&aacute;o de un tr&aacute;ns&aacute;to intestinal. La paciente es dada de alta por mejor&iacute;a de su sintomatolog&iacute;a con tratamiento m&eacute;dico para programar cirug&iacute;a electiva (procedimiento de Ladd) y as&iacute; disminuir el riesgo de v&oacute;lvulose isquemia intestinal. Se discute la presentaci&oacute;n cl&iacute;nica, m&eacute;todos diagn&oacute;sticos y opciones terap&eacute;uticas de la malrotaci&oacute;n intestinal.[Autores. Malrotaci&oacute;n intestinal como causa de dolor abdominal en adultos. Revisi&oacute;n de un&nbsp; caso. MedUNAB 2006; 9: 156-158].Palabras claves: Malrotaci&oacute;n intestinal, obstrucci&oacute;n intestinal, v&oacute;lvulos del intestino medio

Mechanisms of Endothelial Dysfunction in Antiphospholipid Syndrome: Association With Clinical Manifestations

The endothelium is a monolayer of cells that covers the inner surface of blood vessels and its integrity is essential for the maintenance of vascular health. Endothelial dysfunction is a key pathological component of antiphospholipid syndrome (APS). Its systemic complications include thrombotic endocarditis, valvular dysfunction, cerebrovascular occlusions, proliferative nephritis, deep vein thrombosis, and pulmonary embolism. In women, APS is also associated with pregnancy complications (obstetric APS). The conventional treatment regimens for APS are ineffective when the clinical symptoms are severe. Therefore, a better understanding of alterations in the endothelium caused by antiphospholipid antibodies (aPL) may lead to more effective therapies in patients with elevated aPL titers and severe clinical symptoms. Currently, while in vivo analyses of endothelial dysfunction in patients with APS have been reported, most research has been performed using in vitro models with endothelial cells exposed to either patient serum/plasma, monoclonal aPL, or IgGs isolated from patients with APS. These studies have described a reduction in endothelial cell nitric oxide synthesis, the induction of inflammatory and procoagulant phenotypes, an increase in endothelial proliferation, and impairments in vascular remodeling and angiogenesis. Despite these lines of evidence, further research is required to better understand the pathophysiology of endothelial dysfunction in patients with APS. In this review, we have compared the current understanding about the mechanisms of endothelial dysfunction induced by patient-derived aPL under the two main clinical manifestations of APS: thrombosis and gestational complications, either alone or in combination. We also discuss gaps in our current knowledge regarding aPL-induced endothelial dysfunction