828 research outputs found
Non-equilibrium Phase Transitions: Activated Random Walks at Criticality
In this paper we present rigorous results on the critical behavior of the Activated Random Walk model. We conjecture that on a general class of graphs, including Z d , and under general initial conditions, the system at the critical point does not reach an absorbing state. We prove this for the case where the sleep rate λ is infinite. Moreover, for the one-dimensional asymmetric system, we identify the scaling limit of the flow through the origin at criticality. The case λ < +∞ remains largely open, with the exception of the one-dimensional totally-asymmetric case, for which it is known that there is no fixation at criticality.Fil: Cabezas, M.. Conselho Nacional de Desenvolvimiento Cientf y Tec. Associacao Instituto Nacional de Matemática Pura E Aplicada; BrasilFil: Trivellato Rolla, Leonardo. Conselho Nacional de Desenvolvimiento Cientf y Tec. Associacao Instituto Nacional de Matemática Pura E Aplicada; Brasil. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas; ArgentinaFil: Sidoravicius, V.. Conselho Nacional de Desenvolvimiento Cientf y Tec. Associacao Instituto Nacional de Matemática Pura E Aplicada; Brasi
Mechanical Properties of Three-layer Boards of Pine (Pinus radiata) and Pigue (Piptocoma discolor) Owned by the PISMADE S.A. Company
The present study proposes to determine the mechanical properties of three-layer boards of pine (Pinus radiata) and pigue (Piptocoma discolor) owned by the PISMADE S.A. Company. The tests were carried out under established technical procedures, with the use of international standards, at the Materials Resistance laboratory of the Faculty of Mechanics located in the Higher Polytechnic School of Chimborazo. 24 test pieces belonging to three-layer boards provided by the company were evaluated, each of them of different dimensions for bending and compression tests. It was possible to verify the different resistances that the boards of these species support; bending and compression values for both pine and pigue were obtained, appropriate for their use in the industry. The information generated deems this material rigid and appropriate for its efficient and durable use.
Keywords: compression, flexion, mechanical properties, wood boards.
Resumen
El presente estudio propone determinar las propiedades mecánicas en tableros tricapa de pino (Pinus radiata) y pigue (Piptocoma discolor) propiedad de la empresa PISMADE S.A. Los ensayos se los realizó bajo procedimientos técnicos, con la utilización de normas internacionales, dentro del laboratorio de Resistencia de Materiales de la facultad de Mecánica ubicado en la Escuela Superior Politécnica de Chimborazo. Evaluándose 24 probetas pertenecientes a tableros alistonados tricapa, cada una de ellas de diferentes dimensiones para ensayos de flexión y compresión, proporcionados por la empresa. Se pudo comprobar las diferentes resistencias que soportan los tableros de estas especies, obteniendo valores de flexión y compresión tanto para pino y pigue apropiados para su utilización en la industria. La información generada considera a este material rÃgido y apropiado para su uso eficiente y duradero.
Palabras clave: compresión, flexión, propiedades mecánicas, tableros de madera
High throughput SNP discovery and genotyping in grapevine (Vitis vinifera L.) by combining a re-sequencing approach and SNPlex technology
Background: Single-nucleotide polymorphisms (SNPs) are the most abundant type of DNA sequence polymorphisms. Their higher availability and stability when compared to simple sequence repeats (SSRs) provide enhanced possibilities for genetic and breeding applications such as cultivar identification, construction of genetic maps, the assessment of genetic diversity, the detection of genotype/phenotype associations, or marker-assisted breeding. In addition, the efficiency of these activities can be improved thanks to the ease with which SNP genotyping can be automated. Expressed sequence tags (EST) sequencing projects in grapevine are allowing for the in silico detection of multiple putative sequence polymorphisms within and among a reduced number of cultivars. In parallel, the sequence of the grapevine cultivar Pinot Noir is also providing thousands of polymorphisms present in this highly heterozygous genome. Still the general application of those SNPs requires further validation since their use could be restricted to those specific genotypes. Results: In order to develop a large SNP set of wide application in grapevine we followed a systematic re-sequencing approach in a group of 11 grape genotypes corresponding to ancient unrelated cultivars as well as wild plants. Using this approach, we have sequenced 230 gene fragments, what represents the analysis of over 1 Mb of grape DNA sequence. This analysis has allowed the discovery of 1573 SNPs with an average of one SNP every 64 bp (one SNP every 47 bp in non-coding regions and every 69 bp in coding regions). Nucleotide diversity in grape ( = 0.0051) was found to be similar to values observed in highly polymorphic plant species such as maize. The average number of haplotypes per gene sequence was estimated as six, with three haplotypes representing over 83% of the analyzed sequences. Short-range linkage disequilibrium (LD) studies within the analyzed sequences indicate the existence of a rapid decay of LD within the selected grapevine genotypes. To validate the use of the detected polymorphisms in genetic mapping, cultivar identification and genetic diversity studies we have used the SNPlex genotyping technology in a sample of grapevine genotypes and segregating progenies. Conclusion: These results provide accurate values for nucleotide diversity in coding sequences and a first estimate of short-range LD in grapevine. Using SNPlex genotyping we have shown the application of a set of discovered SNPs as molecular markers for cultivar identification, linkage mapping and genetic diversity studies. Thus, the combination a highly efficient re-sequencing approach and the SNPlex high throughput genotyping technology provide a powerful tool for grapevine genetic analysis. © 2007 Lijavetzky et al; licensee BioMed Central Ltd
Mechanical Support Strategies for High-Risk Procedures in the Invasive Cardiac Catheterization Laboratory:A State-of-the-Art Review
Thanks to advancements in percutaneous cardiac interventions, an expanding patient population now qualifies for treatment through percutaneous endovascular procedures. High-risk interventions far exceed coronary interventions and include transcatheter aortic valve replacement, endovascular management of acute pulmonary embolism and ventricular tachycardia ablation. Given the frequent impairment of ventricular function in these patients, frequently deteriorating during percutaneous interventions, it is hypothesized that mechanical ventricular support may improve periprocedural survival and subsequently patient outcome. In this narrative review, we aimed to provide the relevant evidence found for the clinical use of percutaneous mechanical circulatory support (pMCS). We searched the Pubmed database for articles related to pMCS and to pMCS and invasive cath lab procedures. The articles and their references were evaluated for relevance. We provide an overview of the clinically relevant evidence for intra-aortic balloon pump, Impella, TandemHeart and ECMO and their role as pMCS in high-risk percutaneous coronary intervention, transcatheter valvular procedures, ablations and high-risk pulmonary embolism. We found that the right choice of periprocedural pMCS could provide a solution for the hemodynamic challenges during these procedures. However, to enhance the understanding of the safety and effectiveness of pMCS devices in an often high-risk population, more randomized research is needed.</p
Mechanical Support Strategies for High-Risk Procedures in the Invasive Cardiac Catheterization Laboratory:A State-of-the-Art Review
Thanks to advancements in percutaneous cardiac interventions, an expanding patient population now qualifies for treatment through percutaneous endovascular procedures. High-risk interventions far exceed coronary interventions and include transcatheter aortic valve replacement, endovascular management of acute pulmonary embolism and ventricular tachycardia ablation. Given the frequent impairment of ventricular function in these patients, frequently deteriorating during percutaneous interventions, it is hypothesized that mechanical ventricular support may improve periprocedural survival and subsequently patient outcome. In this narrative review, we aimed to provide the relevant evidence found for the clinical use of percutaneous mechanical circulatory support (pMCS). We searched the Pubmed database for articles related to pMCS and to pMCS and invasive cath lab procedures. The articles and their references were evaluated for relevance. We provide an overview of the clinically relevant evidence for intra-aortic balloon pump, Impella, TandemHeart and ECMO and their role as pMCS in high-risk percutaneous coronary intervention, transcatheter valvular procedures, ablations and high-risk pulmonary embolism. We found that the right choice of periprocedural pMCS could provide a solution for the hemodynamic challenges during these procedures. However, to enhance the understanding of the safety and effectiveness of pMCS devices in an often high-risk population, more randomized research is needed.</p
Detection of ethanol, acetone, and propanal in TMC-1: New O-bearing complex organics in cold sources
We present the detection of ethanol (C2H5OH), acetone (CH3COCH3), and
propanal (C2H5CHO) toward the cyanopolyyne peak of TMC-1. These three O-bearing
complex organic molecules are known to be present in warm interstellar clouds,
but had never been observed in a starless core. The addition of these three new
pieces to the puzzle of complex organic molecules in cold interstellar clouds
stresses the rich chemical diversity of cold dense cores in stages prior to the
onset of star formation. The detections of ethanol, acetone, and propanal were
made in the framework of QUIJOTE, a deep line survey of TMC-1 in the Q band
that is being carried out with the Yebes 40m telescope. We derive column
densities of (1.1 +/- 0.3)e12 cm-2 for C2H5OH, (1.4 +/- 0.6)e11 cm-2 for
CH3COCH3, and (1.9 +/- 0.7)e11 cm-2 for C2H5CHO. The formation of these three
O-bearing complex organic molecules is investigated with the aid of a detailed
chemical model which includes gas and ice chemistry. The calculated abundances
at a time around 2e5 yr are in reasonable agreement with the values derived
from the observations. The formation mechanisms of these molecules in our
chemical model are as follows. Ethanol is formed on grains by addition of
atomic carbon on methanol followed by hydrogenation and non-thermal desorption.
Acetone and propanal are produced by the gas-phase reaction between atomic
oxygen and two different isomers of the C3H7 radical, where the latter follows
from the hydrogenation of C3 on grains followed by non-thermal desorption. A
gas-phase route involving the formation of (CH3)2COH+ through several
ion-neutral reactions followed by its dissociative recombination with electrons
do also contribute to the formation of acetone.Comment: Accepted for publication in A&
Evaluación de tres dosis de potasio en la producción de lechuga (Lactuca sativa L. var. Crispa) bajo el sistema hidropónico recirculante NTF bajo invernadero
Three doses of potassium were evaluated in the production of lettuce (Lactuca sativa L. var. Crispa), under the recirculable NFT hydroponic system in the greenhouse of the Department of Horticulture of the ESPOCH. A completely randomized block design was used with three treatments and three replications. The doses evaluated were: low dose (LD) with 224,33 ppm, medium dose (MD) with 470,00 ppm, and high dose (HD) with 716,67 ppm. Evaluated parameters were: potassium content in leaves and root, fresh weights of the aerial part and root, yield per net plot and hectare. The economic analysis was carried out according to the relation benefit/cost. The best results for most of the parameters evaluated were obtained with the low dose (LD), obtaining fresh weights of the aerial part and root of 193,01 and 36,65 g respectively. It has a yield per net plot of 2,04 kilograms and per hectare of 15338,75 kilograms, and the highest cost benefit with 4,63 dollars equivalent to 362,75%. On the other hand, the highest content of potassium in leaves and root up to 40 days after transplant (DAT) was obtained with the medium dose (MD) with 5,13 and 6,00% of total potassium, respectively. In all treatments, maintaining turgor in the plants throughout the cycle is very important. From the agronomic and economic point of view, the use a nutritive solution containing 224,33 ppm of potassium was recommended
In Vitro and In Vivo Biological Activity of Ruthenium 1,10-Phenanthroline-5,6-dione Arene Complexes
Funding Information: We are grateful to Fundação para a Ciência e a Tecnologia, I.P., through MOSTMICRO-ITQB R&D Unit (UIDB/04612/2020, UIDP/04612/2020) and LS4FUTURE Associated Laboratory (LA/P/0087/2020). The NMR spectrometers at CERMAX are integrated in the national NMR Network and partially supported through project 022162. Oscar A. Lenis-Rojas acknowledge national funds through FCT, POPH-Programa Operacional Potencial Humano, and FSE (European Social Fund) for the CEEC 2017 Initiative. Additionally, this work is financed by national funds from FCT—Fundação para a Ciência e a Tecnologia, I.P., in the scope of the project UIDP/04378/2020 and UIDB/04378/2020 of the Research Unit on Applied Molecular Biosciences—UCIBIO and the project LA/P/0140/2020 of the Associate Laboratory Institute for Health and Bioeconomy—i4HB. Publisher Copyright: © 2022 by the authors.Ruthenium(II) arene complexes exhibit promising chemotherapeutic properties. In this study, the effect of the counter anion in Ru(II) complexes was evaluated by analyzing the biological effect of two Ru(II) p-cymene derivatives with the 1,10-phenanthroline-5,6-dione ligand of general-formula [(η6-arene)Ru(L)Cl][X] X = CF3SO3 (JHOR10) and PF6 (JHOR11). The biological activity of JHOR10 and JHOR11 was examined in the ovarian carcinoma cell line A2780, colorectal carcinoma cell line HCT116, doxorubicin-resistant HCT116 (HCT116-Dox) and in normal human dermal fibroblasts. Both complexes JHOR10 and JHOR11 displayed an antiproliferative effect on A2780 and HCT116 cell lines, and low cytotoxicity in fibroblasts. Interestingly, JHOR11 also showed antiproliferative activity in the HCT116-Dox cancer cell line, while JHOR10 was inactive. Studies in A2780 cells showed that JHOR11 induced the production of reactive oxygen species (ROS) that trigger autophagy and cellular senescence, but no apoptosis induction. Further analysis showed that JHOR11 presented no tumorigenicity, with no effect in the cellular mobility, as evaluated by thye wound scratch assay, and no anti- or pro-angiogenic effect, as evaluated by the ex-ovo chorioallantoic membrane (CAM) assay. Importantly, JHOR11 presented no toxicity in chicken and zebrafish embryos and reduced in vivo the proliferation of HCT116 injected into zebrafish embryos. These results show that these are suitable complexes for clinical applications with improved tumor cell cytotoxicity and low toxicity, and that counter-anion alteration might be a viable clinical strategy for improving chemotherapy outcomes in multidrug-resistant (MDR) tumors.publishersversionpublishe
The long noncoding RNA mimi scaffolds neuronal granules to maintain nervous system maturity
RNA binding proteins and messenger RNAs (mRNAs) assemble into ribonucleoprotein granules that regulate mRNA trafficking, local translation, and turnover. The dysregulation of RNA-protein condensation disturbs synaptic plas-ticity and neuron survival and has been widely associated with human neurological disease. Neuronal granules are thought to condense around particular proteins that dictate the identity and composition of each granule type. Here, we show in Drosophila that a previously uncharacterized long noncoding RNA, mimi, is required to scaffold large neuronal granules in the adult nervous system. Neuronal ELAV-like proteins directly bind mimi and mediate granule assembly, while Staufen maintains condensate integrity. mimi granules contain mRNAs and proteins involved in synaptic processes; granule loss in mimi mutant flies impairs nervous system maturity and neuropeptide-mediated signaling and causes phenotypes of neurodegeneration. Our work reports an architectural RNA for a neuronal granule and provides a handle to interrogate functions of a condensate independently of those of its constituent proteins
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