8,595 research outputs found

    Ocurrencia natural del hiperparásito Ampelomyces quisqualis (Ascomycota, Phaeosphaeriaceae) en ambientes urbanos de Tucumán (Argentina)

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    Platanus × acerifolia es usado como un árbol urbano de sombra a lo largo de Argentina. A finales del otoño e invierno del 2023, las hojas y frutos de P. × acerifolia que mostraban los típicos síntomas de un mildiú pulverulento, se recolectaron en las principales calles de Tucumán, Argentina. Basados en su morfología y comparando con descripciones disponibles, el hongo fue identificado como la forma asexual de Erysiphe platani. Los especímenes estaban fuertemente hiperparasitados por Ampelomyces quisqualis, un ascomicete micoparásito usado como controlador biológico natural del desarrollo de especies de mildiú pulverulento. Este trabajo reporta la ocurrencia natural de Ampelomyces en ambientes urbanos de Argentina. Se describen e ilustran los síntomas de la enfermedad y las características morfológicas del anamorfo y el micoparásito.Platanus × acerifolia is used as an urban shade tree in many cities throughout Argentina.In late autumn and winter of 2023, leaves and fruits of P. × acerifolia showingtypical symptoms of a powdery mildew were collected along the main streets ofTucumán, Argentina. Its morphology and comparison with published descriptionsallowed us to identify the fungus as the asexual morph of Erysiphe platani. Thespecimens were heavily hyperparasitized by Ampelomyces quisqualis, a mycoparasiticascomycete, used as a natural biological control of the development of powderymildew species. This work reports the natural occurrence of Ampelomyces in urbanenvironments in Argentina. The disease symptoms and morphological characteristicsof the powdery mildew anamorph and the mycoparasite are described and illustrated.Fil: Castillo, Lucas A.. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; ArgentinaFil: Suarez, Guillermo Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; Argentin

    Nuevos registros de musgos del Bosque Chaqueño Seco en Santiago del Estero, Argentina.

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    Background and aims: The bryophyte flora of Argentina is currently under study, nevertheless, there are still extensive areas unexplored, such as Santiago del Estero with only three records of bryophytes to the entire region. The aim of this work was to contribute to the knowledge of the moss flora of Santiago del Estero province, through the collection of samples in Copo National Park and surroundings. M&M: The specimens were collected in the Copo National Park and surroundings, processed and studied according to traditional techniques for bryophytes. Microscopic characters were observed with stereoscopic and light microscopy. A list of the species found is presented, with comments on the differentiating characters, habitat and distribution. Results: The following moss taxa were found to be new records for the province: Aloina rigida; Dimerodontium balansae; Didymodon umbrosus; Fabronia ciliaris; Macrocoma tenuis subsp. sullivantii; Pseudocrossidium arenicola; P. linearifolium; Stereophyllum radiculosum; Syntrichia chisosa, Trichostomum brachydontium and Venturiella glaziovii. The range of distribution of Tricherpodium beccarii is extended to the northeast of the province. Conclusions: Eleven species and one subspecies, distributed in ten genera and five families, are newly reported for the province of Santiago del Estero. The range of distribution of one species is extended to the northeast of the province. These first studies highlight the unexplored floristic richness of the region and its vulnerability due to the accelerated advance of the agricultural-livestock borderIntroducción y objetivos: La flora briofítica en Argentina se encuentra actualmente en estudio, sin embargo, todavía quedan extensas áreas sin explorar, como lo es la provincia de Santiago del Estero, con solo tres registros de briófitos en toda la región. El objetivo de este trabajo es contribuir al conocimiento de la flora de musgos de la provincia de Santiago del Estero a través de colecciones en el Parque Nacional Copo y sus alrededores. M&M: Las muestras fueron coleccionadas, procesadas y examinadas de acuerdo a las técnicas clásicas para briófitos. Los caracteres microscópicos fueron observados con microscopio óptico y estereoscópico. Se presenta un listado de las especies hasta el momento encontradas en la provincia, con comentarios sobre el hábitat y la distribución. Resultados: Los siguientes taxa de musgos se registran por primera vez para la provincia: Aloina rigida; Dimerodontium balansae; Didymodon umbrosus; Fabronia ciliaris; Macrocoma tenuis subsp. sullivantii; Pseudocrossidium arenicola; P. linearifolium; Stereophyllum radiculosum; Syntrichia chisosa, Trichostomum brachydontium y Venturiella glaziovii. El rango de distribución de Tricherpodium beccarii se amplía hacia el noreste de la provincia. Conclusiones: Once especies y una subespecie, distribuidas en diez géneros y cinco familias se registran por primera vez para Santiago del Estero. El rango de distribución de una especie se extiende al noreste de la provincia. Estos primeros estudios ponen de manifiesto la riqueza florística inexplorada de la región, y la vulnerabilidad de la misma debido al acelerado avance de la frontera agrícola ganaderaFil: Jimenez, Maria Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; ArgentinaFil: Suarez, Guillermo Martin. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; ArgentinaFil: Cabral, Richard A.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; Argentin

    Surgical management of “ab-extrinseco” main stem left coronary compression during pulmonary thromboendarterectomy

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    Extrinsic compression of the left main coronary artery (LMCA) is a common but often underestimated complication of severe pulmonary hypertension (PH) and resulting pulmonary artery (PA) dilatatio

    Mechanical circulatory supports after pulmonary thrombo-endarterectomy: why, when and how

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    Pulmonary endarterectomy (PEA) has radically changed the long-term prognosis of patients with chronic thromboembolic pulmonary hypertension (CTEPH), but the postoperative course is often demanding due to significant hemodynamic and pulmonary circulation variations (1

    Ventricular assist devices implantation: surgical assessment and technical strategies

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    Along with the worldwide increase in continuous left ventricular assist device (LVAD) strategy adoption, more and more patients with demanding anatomical and clinical features are currently referred to heart failure (HF) departments for treatment. Thus surgeons have to deal, technically, with re-entry due to previous cardiac surgery procedures, porcelain aorta, peripheral vascular arterial disease, concomitant valvular or septal disease, biventricular failure. New surgical techniques and surgical tools have been developed to offer acceptable postoperative outcomes to all mechanical circulatory support recipients. Several less invasive and/or thoracotomic approaches for surgery combined with various LVAD inflow and outflow graft alternative anastomotic sites for system placement have been reported and described to solve complex clinical scenarios. Surgical techniques have been upgraded with further technical tips to preserve the native anatomy in case of re-entry for heart transplantation, myocardial recovery or device explant. The current continuous-flow miniaturized and intrapericardial devices provide versatility and technical advantages. However, the surgical planning requires a careful multidisciplinary evaluation which must be driven by a dedicated and well-trained Heart Failure team. Biventricular assist device (BVAD) implantation by adoption of the newer radial pumps might be a challenge. However, the results are encouraging thus remaining a valid option. This paper reviews and summarizes LVAD preoperative assessment and current surgical techniques for implantation

    Defining graphenic crystallites in disordered carbon: moving beyond the platelet model

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    We develop a picture of graphenic crystallites within disordered carbons that goes beyond the traditional model of graphitic platelets at random orientation. Using large atomistic models containing one million atoms, we redefine the meaning of the quantity La extracted from X-ray diffraction (XRD) patterns. Two complementary approaches are used to measure the size of graphenic crystallites, which are defined as regions of regularly arranged hexagons. Firstly, we calculate the X-ray diffraction pattern directly from the atomistic coordinates of the structure and analyse them following a typical experimental process. Second, the graphenic crystallites are identified from a direct geometrical approach. By mapping the structure directly, we replace the idealised picture of the crystallite with a more realistic representation of the material and provide a well-defined interpretation for LaL_a measurements of disordered carbon. A key insight is that the size distribution is skewed heavily towards small fragments, with more than 75% of crystallites smaller than half of LaL_a

    The Zagros Epipalaeolithic revisited: New excavations and 14C dates from Palegawra cave in Iraqi Kurdistan

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    Palegawra cave, alongside its neighbouring Zarzi, has been an emblematic site of the Epipalaeolithic (Zarzian) cultural horizon in the NW Zagros of Southwest Asia ever since its first exploration in 1951 by Bruce Howe and Robert Braidwood in the context of the Iraq-Jarmo project. At the time scientific excavation, sampling and analysis methods were either underdeveloped or did not exist. In this paper we present the first results of new excavations at Palegawra conducted in 2016–2017 by the Eastern Fertile Crescent (EFEC) project, a research collaboration of the University of Liverpool and the Sulaymaniyah Directorate of Antiquities and Heritage. Our research has produced the first radiometric evidence pushing back the chronology of the NW Zagros Epipalaeolithic to the Last Glacial Maximum, thus fully aligning it with Epipalaeolithic facies until now known only from the Levant and the south Anatolian coast. We have also unearthed, for the first time in the Palaeolithic of the Zagros, direct archaeobotanical evidence for hitherto elusive Zarzian plant exploitation and the vegetation of the NW Zagros piedmont zone from the LGM to the end of the Lateglacial (~19,600–13,000 cal BP). The new Palegawra chronology alongside our detailed studies of its material culture and faunal and botanical assemblages suggest that the prevailing Epipalaeolithic habitation pattern in the NW Zagros (centred on generalised persistent occupations of small caves and rock-shelters alongside task-oriented ephemeral open-air campsites) remained an enduring characteristic of the Zarzian horizon throughout this period. The Palegawra data clearly show that neither resource levels and climate conditions nor geographic and/or cultural isolation provide adequate explanations for the stability and longevity of Zarzian lifeways during this long timespan. More fieldwork is required, including the discovery, excavation and intensive sampling of other Zarzian sites, for reaching a datainformed understanding of the nature and evolution of the NW Zagros Epipalaeolithic

    Lamin A Δexon9 mutation leads to telomere and chromatin defects but not genomic instability

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    Over 300 mutations in the LMNA gene, encoding A-type lamins, are associated with 15 human degenerative disorders and premature aging syndromes. Although genomic instability seems to contribute to the pathophysiology of some laminopathies, there is limited information about what mutations cause genomic instability and by which molecular mechanisms. Mouse embryonic fibroblasts depleted of A-type lamins or expressing mutants lacking exons 8–11 (Lmna(Δ8–11/Δ8–11)) exhibit alterations in telomere biology and DNA repair caused by cathepsin L-mediated degradation of 53BP1 and reduced expression of BRCA1 and RAD51. Thus, a region encompassing exons 8–11 seems essential for genome integrity. Given that deletion of lamin A exon 9 in the mouse (Lmna(Δ9/Δ9)) results in a progeria phenotype, we tested if this domain is important for genome integrity. Lmna(Δ9/Δ9) MEFs exhibit telomere shortening and heterochromatin alterations but do not activate cathepsin L-mediated degradation of 53BP1 and maintain expression of BRCA1 and RAD51. Accordingly, Lmna(Δ9/Δ9) MEFs do not present genomic instability, and expression of mutant lamin A Δexon9 in lamin-depleted cells restores DNA repair factors levels and partially rescues nuclear abnormalities. These data reveal that the domain encoded by exon 9 is important to maintain telomere homeostasis and heterochromatin structure but does not play a role in DNA repair, thus pointing to other exons in the lamin A tail as responsible for the genomic instability phenotype in Lmna(Δ8–11/Δ8–11) mice. Our study also suggests that the levels of DNA repair factors 53BP1, BRCA1 and RAD51 could potentially serve as biomarkers to identify laminopathies that present with genomic instability
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