Contribution of time of day and the circadian clock to the heat stress responsive transcriptome in Arabidopsis.

In Arabidopsis, a large subset of heat responsive genes exhibits diurnal or circadian oscillations. However, to what extent the dimension of time and/or the circadian clock contribute to heat stress responses remains largely unknown. To determine the direct contribution of time of day and/or the clock to differential heat stress responses, we probed wild-type and mutants of the circadian clock genes CCA1, LHY, PRR7, and PRR9 following exposure to heat (37 °C) and moderate cold (10 °C) in the early morning (ZT1) and afternoon (ZT6). Thousands of genes were differentially expressed in response to temperature, time of day, and/or the clock mutation. Approximately 30% more genes were differentially expressed in the afternoon compared to the morning, and heat stress significantly perturbed the transcriptome. Of the DEGs (~3000) specifically responsive to heat stress, ~70% showed time of day (ZT1 or ZT6) occurrence of the transcriptional response. For the DEGs (~1400) that are shared between ZT1 and ZT6, we observed changes to the magnitude of the transcriptional response. In addition, ~2% of all DEGs showed differential responses to temperature stress in the clock mutants. The findings in this study highlight a significant role for time of day in the heat stress responsive transcriptome, and the clock through CCA1 and LHY, appears to have a more profound role than PRR7 and PRR9 in modulating heat stress responses during the day. Our results emphasize the importance of considering the dimension of time in studies on abiotic stress responses in Arabidopsis

Ten Year Real World Experience with Ultrafiltration for the Management of Acute Decompensated Heart Failure

Background: Randomized controlled trials (RCT) of ultrafiltration (UF) have demonstrated conflicting results regarding its efficacy and safety. Objective: We reviewed 10 years of data for adjustable UF during heart failure hospitalizations in a real world cohort. Methods: We performed a retrospective, single center analysis of 335 consecutive patients treated with adjustable rate UF using the CHF Solutions Aquadex Flex Flo System from 2009 to 2019. Results: Compared to previous RCTs investigating UF, our cohort was older, with worse renal impairment and more antecedent HF hospitalizations in the year preceding therapy. Mean fluid removal with UF was 14.6 l. Mean weight loss with UF was 15.6 lbs (range 0.2–57 lbs) and was sustained at 1–2 week follow-up. Mean creatinine change upon stopping UF, at discharge and follow-up (mean 30 days) was +0.11 mg/dl, +0.07 mg/dl and +0.11 mg/dl, respectively. HF rehospitalizations at 30 days, 90 days and 1 year were 12.4 %, 14.9 % and 27.3 % respectively. On average patients had 1.74 fewer hospitalizations for HF in the year following UF when compared to 12 months preceding UF. Major bleeding defined as requiring discontinuation of anticoagulation occurred in 3.6 % of patients. Conclusions: Compared with previous UF trials, our study demonstrates that UF compares favorably for HF rehospitalizations, renal function response, and weight/volume loss. Importantly, our real world experience allowed for the adjustment of UF rate during therapy and we believe this is a major contributor to our favorable outcomes. In clinical practice, UF can be a safe and effective strategy for decongestion

Reprogramming of root cells during nitrogen-fixing symbiosis involves dynamic polysome association of coding and noncoding RNAs

Translational control is a widespread mechanism that allows the cell to rapidly modulate gene expression in order to provide flexibility and adaptability to eukaryotic organisms. We applied translating ribosome affinity purification combined with RNA sequencing to characterize translational regulation of mRNAs at early stages of the nitrogen-fixing symbiosis established between Medicago truncatula and Sinorhizobium meliloti. Our analysis revealed a poor correlation between transcriptional and translational changes and identified hundreds of regulated protein-coding and long noncoding RNAs (lncRNAs), some of which are regulated in specific cell types. We demonstrated that a short variant of the lncRNA Trans-acting small interference RNA3 (TAS3) increased its association to the translational machinery in response to rhizobia. Functional analysis revealed that this short variant of TAS3 might act as a target mimic that captures microRNA390, contributing to reduce trans acting small interference Auxin Response Factor production and modulating nodule formation and rhizobial infection. The analysis of alternative transcript variants identified a translationally upregulated mRNA encoding subunit 3 of the SUPERKILLER complex (SKI3), which participates in mRNA decay. Knockdown of SKI3 decreased nodule initiation and development, as well as the survival of bacteria within nodules. Our results highlight the importance of translational control and mRNA decay pathways for the successful establishment of the nitrogen-fixing symbiosis.Fil: Traubenik, Laura Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Biotecnología y Biología Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Biotecnología y Biología Molecular; ArgentinaFil: Reynoso, Mauricio Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Biotecnología y Biología Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Biotecnología y Biología Molecular; ArgentinaFil: Hobecker, Karen Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Biotecnología y Biología Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Biotecnología y Biología Molecular; ArgentinaFil: Lancia, Marcos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Biotecnología y Biología Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Biotecnología y Biología Molecular; ArgentinaFil: Hummel, Maureen. University of California; Estados UnidosFil: Rosen, Benjamin. J. Craig Venter Institute; Estados UnidosFil: Town, Christopher. J. Craig Venter Institute; Estados UnidosFil: Bailey Serres, Julia. University of California; Estados UnidosFil: Blanco, Flavio Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Biotecnología y Biología Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Biotecnología y Biología Molecular; ArgentinaFil: Zanetti, María Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Biotecnología y Biología Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Biotecnología y Biología Molecular; Argentin

ANÁLISE COMPARATIVA DE TÉCNICAS DE FILTRAGEM ESPACIAL EM ÁREA RURAL NA REGIÃO DO MÉDIO ALTO URUGUAI – RS

The image filtering is a technique used to improve the quality of digital images through the incorporation of algorithms , which allow to eliminate unwanted regions, derived from procurement methods or inadequate capture that eventually introduce some kind of noise in images. Thus, the objective is to comparatively evaluate different existing filters in order to add to the knowledge about the process of spatial filtering, since studies of this nature are still scarce in the literature. Image were used regarding the rural municipality of Frederico Westphalen, Landsat-5/TM Imager bands 3 (0.63 to 0.69 µm), 4 (0.76 to 0.90 µm) and 5 (1,55 to 1.75 µm) of the year 1985, previously georeferenced which formed the basis for the registration of the images . It was observed that filtering processes used to demonstrate the efficiency of the filter varies with the target , changing the contrast, brightness and structure are important in the understanding of deterioration caused the original image.A filtragem de imagens é uma técnica utilizada para melhorar a qualidade de imagens digitais, através da incorporação de algoritmos, os quais permitem eliminar regiões indesejáveis, oriundas de métodos de aquisição ou de condições inadequadas de captura, que acabam por introduzir algum tipo de ruído nas imagens. Dessa forma, objetiva-se avaliar comparativamente diferentes filtros existentes, a fim de agregar conhecimentos à cerca do processo de filtragem espacial, já que estudos deste cunho ainda são escassos na literatura. Foram utilizadas imagem referente à zona rural do município de Frederico Westphalen, obtidas do satélite Landsat-5/TM, bandas 3 (0,63 - 0,69 µm), 4 (0,76 - 0,90 µm) e 5 (1,55 - 1,75 µm) do ano de 1985, previamente georreferenciadas que serviram de base para o registro das imagens. Observou-se que os processos de filtragem  utilizados demonstraram que a eficiência dos filtros varia de acordo com o alvo, alterando o contraste, brilho e estrutura, sendo importante no processo de entendimento da deterioração causada na imagem original

DIRECT SEEDING FOR FOREST RESTORATION IN SOUTHERN BRAZIL: INFLUENCE OF SOIL CONDITIONS AND SUBTROPICAL CLIMATE

In this study, we evaluated the direct seeding of tree Atlantic Forest species for ecological restoration under subtropical climate. We aimed to answer: Are the seedling survival and development influenced by the low temperatures in the winter or soil conditions? Which species have the best development and are most suitable for restoration projects in the subtropical region? The study was carried out in a degraded riparian forest in the center of the Rio Grande do Sul state, southern Brazil. The seeded species were Schinus terebinthifolia Raddi, Psidium cattleyanum Sabine, Eugenia uniflora L., Cupania vernalis Cambess., Prunus myrtifolia L. (Urb.), Zanthoxylum rhoifolium Lam. Evaluations were performed monthly for 12 months. Generalized linear models (GLM) were evaluated using emergence, survival and seedling height as response variables, also species and time as explanatory variables with the Gamma distribution. The species that germinated were P. cattleyanum, E. uniflora and C. vernalis. Eugenia uniflora presented a higher germination rate (83.33%) and survival (80.00%) at 360 days after sowing. The species did not differ in height growth. We noted differences in height development over time caused by winter conditions. Cupania vernalis and E. uniflora may be considered as potential species for direct seeding in their natural occurrence areas in southern Brazil. Our study highlights the importance of enhancing ecological aspects of direct seeding

Padrão de distribuição e estrutura populacional de Escallonia bifida Link & Otto em área em vias de restauração no RS

A distribuição populacional das espécies florestais é um importante subsídio para o entendimento da estrutura da floresta, e seu manejo econômico e conservacionista. Desse modo, o objetivo do presente trabalho é o estudo da estrutura populacional da espécie nativa Escallonia bifida Link & Otto, em área em vias de restauração na região central do RS. Foram amostrados todos os indivíduos da espécie presentes na classe regenerativa e arbórea nos anos de 2011 e 2012. Para avaliação da classe arbórea foram implantadas 16 parcelas de 10 x 10 m (Classe III) e 64 subparcelas de 5 x 5 m (Classe II) e para a regeneração 64 subparcelas de 5 x 5 m (Classe I). Na classe III foram medidos indivíduos de CAP ≥ 15 cm, na classe II indivíduos de 5,1 ≥ CAP ≤ 14,9 cm e classe I: 1 ≤ CAP ≥ 5 cm. Na avaliação da estrutura populacional foram analisados os parâmetros fitossociológicos, a distribuição espacial através do índice de Morisita e a distribuição diamétrica. A população de Escallonia bifida apresentou diminuição na frequência, densidade, valor de cobertura e importância de 2011 para 2012 e comportamento agregado. A distribuição diamétrica dos indivíduos apresentou modificações estruturais de 2011 para 2012, o que pode ser indicativo de mudanças sucessionais no fragmento em estudo

Ethylene augments root hypoxia tolerance via growth cessation and reactive oxygen species amelioration

Flooded plants experience impaired gas diffusion underwater, leading to oxygen deprivation (hypoxia). The volatile plant hormone ethylene is rapidly trapped in submerged plant cells and is instrumental for enhanced hypoxia acclimation. However, the precise mechanisms underpinning ethylene-enhanced hypoxia survival remain unclear. We studied the effect of ethylene pre-treatment on hypoxia survival of Arabidopsis (Arabidopsis thaliana) primary root tips. Both hypoxia itself and re-oxygenation following hypoxia are highly damaging to root tip cells, and ethylene pre-treatments reduced this damage. Ethylene pre-treatment alone altered the abundance of transcripts and proteins involved in hypoxia responses, root growth, translation, and reactive oxygen species (ROS) homeostasis. Through imaging and manipulating ROS abundance in planta, we demonstrated that ethylene limited excessive ROS formation during hypoxia and subsequent re-oxygenation and improved oxidative stress survival in a PHYTOGLOBIN1-dependent manner. In addition, we showed that root growth cessation via ethylene and auxin occurred rapidly and that this quiescence behavior contributed to enhanced hypoxia tolerance. Collectively, our results show that the early flooding signal ethylene modulates a variety of processes that all contribute to hypoxia survival

Assessing forest vegetation and fire simulation model performance after the Cold Springs wildfire, Washington USA

Given that resource managers rely on computer simulation models when it is difficult or expensive to obtain vital information directly, it is important to evaluate how well a particular model satisfies applications for which it is designed. The Forest Vegetation Simulator (FVS) is used widely for forest management in the US, and its scope and complexity continue to increase. This paper focuses on the accuracy of estimates made by the Fire and Fuels Extension (FFE-FVS) predictions through comparisons between model outputs and measured post-fire conditions for the Cold Springs wildfire and on the sensitivity of model outputs to weather, disease, and fuel inputs. For each set of projected, pre-fire stand conditions, a fire was simulated that approximated the actual conditions of the Cold Springs wildfire as recorded by local portable weather stations. We also simulated a fire using model default values. From the simulated post-fire conditions, values of tree mortality and fuel loads were obtained for comparison to post-fire, observed values. We designed eight scenarios to evaluate how model output changed with varying input values for three parameter sets of interest: fire weather, disease, and fuels. All of the tested model outputs displayed some sensitivity to alternative model inputs. Our results indicate that tree mortality and fuels were most sensitive to whether actual or default weather was used and least sensitive to whether or not disease data were included as model inputs. The performance of FFE-FVS for estimating total surface fuels was better for the scenarios using actual weather data than for the scenarios using default weather data. It was rare that the model could predict fine fuels or litter. Our results suggest that using site-specific information over model default values could significantly improve the accuracy of simulated values

Sucrose Control of Translation Mediated by an Upstream Open Reading Frame-Encoded Peptide1[W][OA]

Regulation of gene expression through translational control is common in many organisms. The Arabidopsis (Arabidopsis thaliana) transcription factor bZIP11 is translational repressed in response to sucrose (Suc), resulting in Suc-regulated changes in amino acid metabolism. The 5′ leader of the bZIP11 mRNA harbors several upstream open reading frames (uORFs), of which the second uORF is well conserved among bZIP11 homologous genes. The uORF2 element encodes a Suc control peptide (SC-peptide) of 28 residues that is sufficient for imposing Suc-induced repression of translation (SIRT) on a heterologous mRNA. Detailed analysis of the SC-peptide suggests that it functions as an attenuator peptide. Results suggest that the SC-peptide inhibits bZIP11 translation in response to high Suc levels by stalling the ribosome on the mRNA. The conserved noncanonical AUG contexts of bZIP11 uORFs allow inefficient translational initiation of the uORF, resulting in translation initiation of the scanning ribosome at the AUG codon of the bZIP11 main ORF. The results presented show that Suc-dependent signaling mediates differential translation of mRNAs containing SC-peptides encoding uORFs

Contribution of time of day and the circadian clock to the heat stress responsive transcriptome in Arabidopsis.

In Arabidopsis, a large subset of heat responsive genes exhibits diurnal or circadian oscillations. However, to what extent the dimension of time and/or the circadian clock contribute to heat stress responses remains largely unknown. To determine the direct contribution of time of day and/or the clock to differential heat stress responses, we probed wild-type and mutants of the circadian clock genes CCA1, LHY, PRR7, and PRR9 following exposure to heat (37 °C) and moderate cold (10 °C) in the early morning (ZT1) and afternoon (ZT6). Thousands of genes were differentially expressed in response to temperature, time of day, and/or the clock mutation. Approximately 30% more genes were differentially expressed in the afternoon compared to the morning, and heat stress significantly perturbed the transcriptome. Of the DEGs (~3000) specifically responsive to heat stress, ~70% showed time of day (ZT1 or ZT6) occurrence of the transcriptional response. For the DEGs (~1400) that are shared between ZT1 and ZT6, we observed changes to the magnitude of the transcriptional response. In addition, ~2% of all DEGs showed differential responses to temperature stress in the clock mutants. The findings in this study highlight a significant role for time of day in the heat stress responsive transcriptome, and the clock through CCA1 and LHY, appears to have a more profound role than PRR7 and PRR9 in modulating heat stress responses during the day. Our results emphasize the importance of considering the dimension of time in studies on abiotic stress responses in Arabidopsis