309 research outputs found
Modelo predictivo de la severidad del tizón foliar por Cercospora kikuchii mediante variables meteorológicas
Introducción. En el manejo integrado de enfermedades es importante incorporar elementos como umbrales de daño económico, monitoreo y sistemas de pronóstico de riesgo, los cuales constituyen herramientas para definir estrategias de control de las mismas. Objetivo. Desarrollar un modelo predictivo de la severidad del tizón foliar por Cercospora (TFC) mediante variables meteorológicas para el norte de la provincia de Buenos Aires, Argentina. Materiales y métodos. Se contó con datos de incidencia y severidad del TFC correspondientes a cinco ciclos productivos de soja (2013-2017) de Pergamino, Buenos Aires, relevados en distintos estados reproductivos R1 a R7. La variable dependiente fue la probabilidad de ocurrencia de niveles categorizados de la tasa de incremento (TI) de la severidad del TFC causado por C. kikuchii. Los elementos y variables meteorológicas utilizados fueron registros diarios de temperatura máxima y mínima, precipitación y humedad relativa. Se calculó el coeficiente de correlación no paramétrico de Kendall Tau-b entre los niveles categorizados binariamente de TI de la severidad del TFC y las variables meteorológicas. Resultados. Las variables meteorológicas con mayor correlación en relación con la TI del TFC fueron aquellas relacionadas con la humedad relativa (DHR, MOJRO, DHRT). La inclusión de una variable térmica (GDTmax) resultó importante para el ajuste del modelo predictivo. Conclusión. Se pudo desarrollar un modelo de predicción de la severidad del TFC que incluyó dos variables meteorológicas, una relacionada con los días la humedad relativa y otra térmica relacionada con un límite de temperatura máxima para el desarrollo de la enfermedad. Para validar y robustecer el modelo propuesto es necesario contar con más datos de severidad a través de los años.
The Identity of the Crackling, Luminescent Frog of Suriname (\u3cem\u3eRana typhonia\u3c/em\u3e Linnaeus, 1758) (Amphibia, Anura)
Review of the literature and recently available field notes from the collector of the type allows a reconsideration of the identity of the Linnaean name Rana typhonia. We provide evidence to demonstrate that the Linnaean species is neither a bufonid nor an Asiatic ranid, but a Neotropical hylid. Subsequently, we consider Rana typhonia as an older synonym of Rana venulosa Laurenti, 1768, redescribing its holotype under the new combination, Trachycephalus typhonius (Linnaeus, 1758)
Detección morfológica de la podredumbre carbonosa en soja y maíz en Misiones, Argentina
Introducción. La podredumbre carbonosa causada por Macrophomina phaseolina es un patógeno que sobrevive en el suelo mediante microesclerocios (fase de Sclerotium bataticola). Este patógeno afecta a diferentes cultivos, entre los que se destancan la soja (Glycine max L. Merrill) y el maíz (Zea mays L.), por su importancia en la Argentina. Objetivo. Demostrar que el causante de las muertes de las plantas de soja y de maíz en los años de sequía en la provincia de Misiones es la prodredumbre carbonosa. Materiales y métodos. Se recolectaron muestras de diferentes localidades de la provincia de Misiones, Argentina, durante febrero de 2022. Mediante la observación a ojo desnudo de plantas enfermas y con el auxilio de microscopia estereoscópica y microscoscopio óptico se determinó la identidad del patógeno presente. Resultados. Se detectó la presencia de microesclerocios compatibles con S. bataticola como agente causal de podredumbre carbonosa en las muestras de maíz y soja, en todas las muestras de la provincia de Misiones. Conclusión. La podredumbre carbonosa causada por M. phaseolina se encuentra presente en los cultivos de soja y de maíz en la provincia de Misiones, Argentina.
Contexto arquitectónico y desarrollo tecnológico del Cine Monumental de Teodoro Anasagasti
Overcoming the economical crisis that Spain suffered in the twentieth century allowed to build more edifices and made possible to follow the concepts of modern European movement. Cinemas were one of the best examples of this attempt of modernity. There are few examples of real quality architecture, and majority of them were built in Madrid or Barcelona. In this context, one of that years’ greatest works has to be put in value: Teodoro Anasagasti’s Monumental Cinema, providing additional architectonic and technological data to the existing historiography.La superación de la crisis que caracterizó la economía española en los años veinte permitió que pudiesen construirse más edificios y que fuese posible seguir los conceptos de las corrientes modernas europeas. Los cines fueron uno de los géneros más dados a ese intento de modernidad. Existen pocos ejemplos de verdadera calidad arquitectónica, y la mayoría de ellos se edificaron en las grandes ciudades, como Madrid y Barcelona. Y es en este contexto donde cobra todo sentido rescatar del pasado una de las grandes obras construidas en aquellos años: el Cine Monumental de Teodoro de Anasagasti, aportando datos arquitectónicos y tecnológicos adicionales a la historiografía existente
Identification of novel plant cysteine oxidase inhibitors from a yeast chemical genetic screen
Hypoxic responses in plants involve Plant Cysteine Oxidases (PCOs). They catalyze the N-terminal cysteine oxidation of Ethylene Response Factors VII (ERF-VII) in an oxygen-dependent manner, leading to their degradation via the cysteine N-degron pathway (Cys-NDP) in normoxia. In hypoxia, PCO activity drops, leading to the stabilization of ERF-VIIs and subsequent hypoxic gene upregulation. Thus far, no chemicals have been described to specifically inhibit PCO enzymes. In this work, we devised an in vivo pipeline to discover Cys-NDP effector molecules. Budding yeast expressing AtPCO4 and plant-based ERF-VII reporters was deployed to screen a library of natural-like chemical scaffolds and was further combined with an Arabidopsis Cys-NDP reporter line. This strategy allowed us to identify three PCO inhibitors, two of which were shown to affect PCO activity in vitro. Application of these molecules to Arabidopsis seedlings led to an increase in ERF-VII stability, induction of anaerobic gene expression, and improvement of tolerance to anoxia. By combining a high-throughput heterologous platform and the plant model Arabidopsis, our synthetic pipeline provides a versatile system to study how the Cys-NDP is modulated. Its first application here led to the discovery of at least two hypoxia-mimicking molecules with the potential to impact plant tolerance to low oxygen stress
A multicomponent reaction platform towards multimodal near-infrared BODIPY dyes for STED and fluorescence lifetime imaging
We report a platform combining multicomponent reaction synthesis and automated cell-based screening to develop biocompatible NIR-BODIPY fluorophores. From a library of over 60 fluorophores, we optimised compound NIRBD-62c as a multimodal probe with suitable properties for STED super-resolution and fluorescence lifetime imaging. Furthermore, we employed NIRBD-62c for imaging trafficking inside cells and to examine how pharmacological inhibitors can alter the vesicular traffic between intracellular compartments and the plasma membrane
Intravitreal implants manufactured by supercritical foaming for treating retinal diseases
Chronic retinal diseases, such as age-related macular degeneration (AMD), are a major cause of global visual impairment. However, current treatment methods involving repetitive intravitreal injections pose financial and health burdens for patients. The development of controlled drug release systems, particularly for biological drugs, is still an unmet need in prolonging drug release within the vitreous chamber. To address this, green supercritical carbon dioxide (scCO2) foaming technology was employed to manufacture porous poly(lactic-co-glycolic acid) (PLGA)-based intravitreal implants loaded with dexamethasone. The desired implant dimensions were achieved through 3D printing of customised moulds. By varying the depressurisation rates during the foaming process, implants with different porosities and dexamethasone release rates were successfully obtained. These implants demonstrated controlled drug release for up to four months, surpassing the performance of previously developed implants. In view of the positive results obtained, a pilot study was conducted using the monoclonal antibody bevacizumab to explore the feasibility of this technology for preparing intraocular implants loaded with biologic drug molecules. Overall, this study presents a greener and more sustainable alternative to conventional implant manufacturing techniques, particularly suited for drugs that are susceptible to degradation under harsh conditions
Endothelin-1 promotes vascular smooth muscle cell migration across the artery wall: a mechanism contributing to vascular remodelling and intimal hyperplasia in giant-cell arteritis
Background: Giant-cell arteritis (GCA) is an inflammatory disease of large/medium-sized arteries, frequently involving the temporal arteries (TA). Inflammation-induced vascular remodelling leads to vaso-occlusive events. Circulating endothelin-1 (ET1) is increased in patients with GCA with ischaemic complications suggesting a role for ET-1 in vascular occlusion beyond its vasoactive function. Objective: To investigate whether ET-1 induces a migratory myofibroblastic phenotype in human TAderived vascular smooth muscle cells (VSMC) leading to intimal hyperplasia and vascular occlusion in GCA. Methods and results: Immunofluorescence/confocal microscopy showed increased ET-1 expression in GCA lesions compared with control arteries. In inflamed arteries, ET-1 was predominantly expressed by infiltrating mononuclear cells whereas ET receptors, particularly ET-1 receptor B (ETB R), were expressed by both mononuclear cells and VSMC. ET-1 increased TA-derived VSMC migration in vitro and α-smooth muscle actin (αSMA) expression and migration from the media to the intima in cultured TA explants. ET-1 promoted VSMC motility by increasing activation of focal adhesion kinase (FAK), a crucial molecule in the turnover of focal adhesions during cell migration. FAK activation resulted in Y397 autophosphorylation creating binding sites for Src kinases and the p85 subunit of PI3kinases which, upon ET-1 exposure, colocalised with FAK at the focal adhesions of migrating VSMC. Accordingly, FAK or PI3K inhibition abrogated ET-1-induced migration in vitro. Consistently, ET-1 receptor A and ETB R antagonists reduced αSMA expression and delayed VSMC outgrowth from cultured GCA-involved artery explants. Conclusions: ET-1 is upregulated in GCA lesions and, by promoting VSMC migration towards the intimal layer, may contribute to intimal hyperplasia and vascular occlusion in GCA
Extended-Spectrum-Beta-Lactamases, AmpC Beta-Lactamases and Plasmid Mediated Quinolone Resistance in Klebsiella spp. from Companion Animals in Italy
We report the genetic characterization of 15 Klebsiella pneumoniae (KP) and 4 isolates of K. oxytoca (KO) from clinical cases in dogs and cats and showing extended-spectrum cephalosporin (ESC) resistance. Extended spectrum beta-lactamase (ESBL) and AmpC genes, plasmid-mediated quinolone resistance (PMQR) and co-resistances were investigated. Among KP isolates, ST101 clone was predominant (8/15, 53%), followed by ST15 (4/15, 27%). ST11 and ST340, belonging to Clonal Complex (CC)11, were detected in 2012 (3/15, 20%). MLST on KP isolates corresponded well with PFGE results, with 11 different PFGE patterns observed, including two clusters of two (ST340) and four (ST101) indistinguishable isolates, respectively. All isolates harbored at least one ESBL or AmpC gene, all carried on transferable plasmids (IncR, IncFII, IncI1, IncN), and 16/19 were positive for PMQR genes (qnr family or aac(6')-Ib-cr). The most frequent ESBL was CTX-M-15 (11/19, 58%), detected in all KP ST101, in one KP ST15 and in both KP ST340. blaCTX-M-15 was carried on IncR plasmids in all but one KP isolate. All KP ST15 isolates harbored different ESC resistance genes and different plasmids, and presented the non-transferable blaSHV-28 gene, in association with blaCTX-M-15, blaCTX-M-1 (on IncR, or on IncN), blaSHV-2a (on IncR) or blaCMY-2 genes (on IncI1). KO isolates were positive for blaCTX-M-9 gene (on IncHI2), or for the blaSHV-12 and blaDHA-1 genes (on IncL/M). They were all positive for qnr genes, and one also for the aac(6')-Ib-cr gene. All Klebsiella isolates showed multiresistance towards aminoglycosides, sulfonamides, tetracyclines, trimethoprim and amphenicols, mediated by strA/B, aadA2, aadB, ant (2")-Ia, aac(6')-Ib, sul, tet, dfr and cat genes in various combinations. The emergence in pets of multidrug-resistant Klebsiella with ESBL, AmpC and PMQR determinants, poses further and serious challenges in companion animal therapy and raise concerns for possible bi-directional transmission between pets and humans, especially at household level
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