Active mechanics reveal molecular-scale force kinetics in living oocytes

Active diffusion of intracellular components is emerging as an important process in cell biology. This process is mediated by complex assemblies of molecular motors and cytoskeletal filaments that drive force generation in the cytoplasm and facilitate enhanced motion. The kinetics of molecular motors have been precisely characterized in-vitro by single molecule approaches, however, their in-vivo behavior remains elusive. Here, we study the active diffusion of vesicles in mouse oocytes, where this process plays a key role in nuclear positioning during development, and combine an experimental and theoretical framework to extract molecular-scale force kinetics (force, power-stroke, and velocity) of the in-vivo active process. Assuming a single dominant process, we find that the nonequilibrium activity induces rapid kicks of duration $\tau \sim$ 300 $\mu$s resulting in an average force of $F \sim$ 0.4 pN on vesicles in in-vivo oocytes, remarkably similar to the kinetics of in-vitro myosin-V. Our results reveal that measuring in-vivo active fluctuations allows extraction of the molecular-scale activity in agreement with single-molecule studies and demonstrates a mesoscopic framework to access force kinetics.Comment: 20 pages, 4 figures, see ancillary files for Supplementary Materials, * equally contributing author

Skin and Non-Solid Cancer Incidence in Interventional Radiology using Biological and Physical Dosimetry Methods

Non

Resistência extrema a duas estirpes do Potato virus Y (PVY) de batata transgênica, cv. Achat, expressando o gene da capa protéica do PVYO

The coat protein (CP) gene of the potato virus Y strain “o” (PVYO) was introduced into potato, cultivar Achat, via Agrobacterium tumefaciens-mediated transformation. Sixty three putative transgenic lines were challenged against the Brazilian strains PVY-OBR and PVY-NBR. An extremely resistant phenotype, against the two strains, was observed in one line, denominated 1P. No symptoms or positive ELISA results were observed in 16 challenged plants from this line. Another clone, named as 63P, showed a lower level of resistance. Southern blot analysis showed five copies of the CP gene in the extremely resistant line and at least three copies in the other resistant line. The stability of the integrated transgenes in the extreme resistant line was examined during several in vitro multiplications over a period of three years, with no modification in the Southern pattern was observed. The stability of the transgenes, the absence of primary infections and the relatively broad spectrum of resistance suggest that the extremely resistant line obtained in this work can be useful for agricultural purposes.O gene da capa protéica (CP) do Potato virus Y estirpe “o”, foi introduzido em batata cultivar Achat, via Agrobacterium tumefaciens. Sessenta e três linhas possivelmente transgênicas foram desafiadas com as estirpes brasileiras PVY-OBR e PVY-NBR. Uma linha apresentou extrema resistência às duas estirpes inoculadas, e foi denominado clone 1P. Não foram observados sintomas sistêmicos de infecção e as plantas foram negativas em Elisa. Outra linha, denominada clone 63P, mostrou algum nível de resistência. Análises por Southern blot indicaram a presença de pelo menos cinco cópias do gen CP no clone 1P e pelo menos três cópias no clone 63P. A estabilidade do gene introduzido no clone 1P foi avaliada durante três anos, após várias multiplicações in vitro. Não foram observadas mudanças no padrão do Southern blot. A estabilidade do transgene, na ausência de infecções primárias e relativo largo espectro de resistência sugerem que o clone 1P pode ser utilizado para fins comerciais.Fil: Romano, Eduardo. Embrapa Recursos Genéticos; BrasilFil: Ferreira, Adriana T.. Embrapa Hortaliças; BrasilFil: Dusi, André N.. Embrapa Hortaliças; BrasilFil: Proite, Karina. Embrapa Recursos Genéticos; BrasilFil: Buso, Jose A.. Embrapa Hortaliças; BrasilFil: Avila, Antonio C.. Embrapa Hortaliças; BrasilFil: Nishijima, Marta L.. Embrapa Hortaliças; BrasilFil: Nascimento, Adriana S.. Embrapa Hortaliças; BrasilFil: Bravo Almonacid, Fernando Felix. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Mentaberry, Alejandro Nestor. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Monte, Damares. Embrapa Recursos Genéticos; BrasilFil: Campos, Magnolia A.. Embrapa Recursos Genéticos; BrasilFil: Melo, Paulo Eduardo. Embrapa Hortaliças; BrasilFil: Cattony, Monica K.. No especifica;Fil: Torres, Antonio C.. Embrapa Hortaliças; Brasi

Selective pressure against horizontally acquired prokaryotic genes as a driving force of plastid evolution

Altres ajuts: del Consejo Nacional de Investigaciones Científicas y Técnicas- Argentina (CONICET) i del Programa Iberoamericano de Ciencia y Tecnología para el Desarrollo (IBERCAROT).The plastid organelle comprises a high proportion of nucleus-encoded proteins that were acquired from different prokaryotic donors via independent horizontal gene transfers following its primary endosymbiotic origin. What forces drove the targeting of these alien proteins to the plastid remains an unresolved evolutionary question. To better understand this process we screened for suitable candidate proteins to recapitulate their prokaryote-to-eukaryote transition. Here we identify the ancient horizontal transfer of a bacterial polyphenol oxidase (PPO) gene to the nuclear genome of an early land plant ancestor and infer the possible mechanism behind the plastidial localization of the encoded enzyme. Arabidopsis plants expressing PPO versions either lacking or harbouring a plastid-targeting signal allowed examining fitness consequences associated with its subcellular localization. Markedly, a deleterious effect on plant growth was highly correlated with PPO activity only when producing the non-targeted enzyme, suggesting that selection favoured the fixation of plastid-targeted protein versions. Our results reveal a possible evolutionary mechanism of how selection against heterologous genes encoding cytosolic proteins contributed in incrementing plastid proteome complexity from non-endosymbiotic gene sources, a process that may also impact mitochondrial evolution

Innovaciones en centros educativos vulnerables: liceos que optimizan la gestión para mejorar los aprendizajes de sus estudiantes

Un equipo universitario multidisciplinario ha desarrollado una innovación integral en cuatro establecimientos educacionales secundarios, a partir del diseño, instalación y consolidación de procesos autosustentables en la gestión directiva, pedagógica y de convivencia e inclusión, con el propósito de promover un mejoramiento significativo en la calidad de los aprendizajes de los estudiantes de sectores sociales de alta vulnerabilidad. Este programa de asesoría se ha llevado a cabo a través de la implementación de un plan de acción que consideró principalmente a los directivos, los docentes y los estudiantes. Se plantearon reuniones periódicas con los equipos directivos, entrevistas y capacitación docente en metodologías participativas, prácticas evaluativas y utilización de tecnologías de información y comunicación. Además, se trabajó directamente con los estudiantes por medio de talleres, charlas y entrevistas. Dentro de los resultados de esta asesoría se destacan: la apropiación de un plan de gestión por parte de los directivos, el mejoramiento de las prácticas docentes y una mayor disposición hacia los aprendizajes por parte de los estudiantes que participaron en los programas orientados hacia ellos, además de una mejor convivencia entre los estudiantes y entre éstos y los docente

Photovoltaic Cleaning Frequency Optimization Under Different Degradation Rate Patterns

Dust accumulation significantly affects the performance of photovoltaic modules and its impact can be mitigated by various cleaning methods. Optimizing the cleaning frequency is therefore essential to minimize the soiling losses and, at the same time, the costs. However, the effectiveness of cleaning lowers with time because of the reduced energy yield due to degradation. Additionally, economic factors such as the escalation in electricity price and inflation can either compound or counterbalance the effect of degradation. The present study analyzes the impact of degradation, escalation in electricity price and inflation on cleaning frequency and proposes a methodology than can be applied to maximize the profits of soiling mitigation in any system worldwide. The energy performance and soiling losses of a 1 MW system installed in southern Spain were analyzed and integrated with theoretical linear and nonlinear degradation rate patterns. The Levelized Cost of Energy and Net Present Value were used as criteria to identify the optimum cleaning strategies. The results showed that the two metrics convey distinct cleaning recommendations, as they are influenced by different factors. For the given site, despite the degradation effects, the optimum cleaning frequency is found to increase with time of operation

Photovoltaic Cleaning Frequency Optimization Under Different Degradation Rate Patterns

Dust accumulation significantly affects the performance of photovoltaic modules and its impact can be mitigated by various cleaning methods. Optimizing the cleaning frequency is therefore essential to minimize the soiling losses and, at the same time, the costs. However, the effectiveness of cleaning lowers with time because of the reduced energy yield due to degradation. Additionally, economic factors such as the escalation in electricity price and inflation can either compound or counterbalance the effect of degradation. The present study analyzes the impact of degradation, escalation in electricity price and inflation on cleaning frequency and proposes a methodology than can be applied to maximize the profits of soiling mitigation in any system worldwide. The energy performance and soiling losses of a 1 MW system installed in southern Spain were analyzed and integrated with theoretical linear and nonlinear degradation rate patterns. The Levelized Cost of Energy and Net Present Value were used as criteria to identify the optimum cleaning strategies. The results showed that the two metrics convey distinct cleaning recommendations, as they are influenced by different factors. For the given site, despite the degradation effects, the optimum cleaning frequency is found to increase with time of operation

Digital Therapeutics Care Utilizing Genetic and Gut Microbiome Signals for the Management of Functional Gastrointestinal Disorders: Results From a Preliminary Retrospective Study

Diet and lifestyle-related illnesses including functional gastrointestinal disorders (FGIDs) and obesity are rapidly emerging health issues worldwide. Research has focused on addressing FGIDs via in-person cognitive-behavioral therapies, diet modulation and pharmaceutical intervention. Yet, there is paucity of research reporting on digital therapeutics care delivering weight loss and reduction of FGID symptom severity, and on modeling FGID status and symptom severity reduction including personalized genomic SNPs and gut microbiome signals. Our aim for this study was to assess how effective a digital therapeutics intervention personalized on genomic SNPs and gut microbiome signals was at reducing symptomatology of FGIDs on individuals that successfully lost body weight. We also aimed at modeling FGID status and FGID symptom severity reduction using demographics, genomic SNPs, and gut microbiome variables. This study sought to train a logistic regression model to differentiate the FGID status of subjects enrolled in a digital therapeutics care program using demographic, genetic, and baseline microbiome data. We also trained linear regression models to ascertain changes in FGID symptom severity of subjects at the time of achieving 5% or more of body weight loss compared to baseline. For this we utilized a cohort of 177 adults who reached 5% or more weight loss on the Digbi Health personalized digital care program, who were retrospectively surveyed about changes in symptom severity of their FGIDs and other comorbidities before and after the program. Gut microbiome taxa and demographics were the strongest predictors of FGID status. The digital therapeutics program implemented, reduced the summative severity of symptoms for 89.42% (93/104) of users who reported FGIDs. Reduction in summative FGID symptom severity and IBS symptom severity were best modeled by a mixture of genomic and microbiome predictors, whereas reduction in diarrhea and constipation symptom severity were best modeled by microbiome predictors only. This preliminary retrospective study generated diagnostic models for FGID status as well as therapeutic models for reduction of FGID symptom severity. Moreover, these therapeutic models generate testable hypotheses for associations of a number of biomarkers in the prognosis of FGIDs symptomatology