405 research outputs found
The Influence of Bulk Density on the Hydraulic Conductivity and Water Content-Matric Suction Relation of Two Soils
The influence of bulk density on saturated, unsaturated hydraulic conductivity , diffusivity and water con tent was measured on undisturbed and disturbed soil samples of Vernal sandy loam and Nibley silty clay loam. Bulk density was changed by artificially compacting the samples.
There was a very large decrease in hydraulic conductivity and diffusivity as water content decreased as has been noted by many others . For the disturbed and compacted samples of the Vernal sandy loam, the water content was higher at .33 and 1.0 bar suction than for the disturbed-uncompacted samples. The same general effect was noted for the undisturbed samples, but differences due to treatment were small. The reverse was true at .05 bars.
In the Nibley silty clay loam samples, water content was higher for the uncompacted than for the compacted samples at all suctions applied. The effect of compaction on unsaturated hydraulic conductivity and diffusivity was not consistent. At the same value of water content, both diffusivity and unsaturated hydraulic conductivity were sometimes higher in the compacted samples, others lower than in the uncompacted
Uma extensão do ncRNA-Agents : um estudo de caso para o gênero Oryza do reino Plantae
Monografia (graduação)—Universidade de Brasília, Instituto de Exatas, Departamento de Ciência da Computação, 2015.Neste trabalho, criamos uma nova instância do ncRNA-Agents, um sistema de anotação
de RNAs não-codificadores (ncRNAs) baseado em sistemas multiagentes. Nesta versão,
o usuário pode anotar ncRNAs de plantas, usando sequências de cDNA dos organismos
Oryza barthii, Oryza brachyantha, Oryza glaberrima, Oryza glumaepatula, Oryza longistaminata,
Oryza meridionalis, Oryza nivara, Oryza punctata, Oryza rufipogon e Oryza
sativa Indica. Além disso, foi incluído o software snoReport para anotar snoRNAs (C/D
box e H/ACA box), um tipo específico de ncRNA. Por fim desenvolvemos um estudo de
caso para a espécieOryza sativa Japonica.In this work, we create a new instance of ncRNA-Agents, an annotation system of noncoding
RNA’s (ncRNA’s) based on multiagent systems. In this version, the user can annotate
plant ncRNAs using the sequences of cDNA of Oryza barthii Oryza brachyantha,
Oryza glaberrima, Oryza glumaepatula,Oryza longistaminata, Oryza meridionalis, Oryza
nivara, Oryza punctata, Oryza rufipogon and Oryza sativa Indica as reference. Furthermore,
the software snoReport was included to annotate snoRNAs (C/D and box H/ACA
box), a specific type of order ncRNA. Finally, we developed a case study for the species
Oryza sativa Japonica
Longitudinal attenuation in political polarization: evidence from COVID-19 vaccination adherence in Brazil
Background: While political polarization in policy opinions, preferences, and observance is well established, little is known about whether and how such divisions evolve, and possibly attenuate, over time. Using the COVID-19 pandemic in Brazil as the backdrop, we examine the longitudinal evolution of a highly relevant and polarizing policy: adherence to the COVID-19 vaccination.
Methods: Studies 1 (N = 3346) and 2 (N = 10,214) use nationwide surveys to document initial differences and subsequent changes in vaccination adherence between conservatives ("Bolsonaristas") and non-conservatives ("non-Bolsonaristas"). Study 3 (N = 742) uses an original dataset to investigate belief changes among conservatives and their association with asymmetric changes in vaccination adherence.
Results: Despite substantial differences at the early stages of rollout, the gap in vaccination adherence between conservatives and non-conservatives significantly decreased with the passage of time, driven essentially by a much faster uptake among the initially most skeptic—the conservatives. Study 3 demonstrates that the asymmetric changes in vaccination adherence were associated with meaningful belief changes among the conservatives, especially about the perceived effectiveness of the COVID-19 vaccines and the expected adherence of peers to the vaccination campaign.
Conclusions: Together, these studies show that, in a context where the superiority of the promoted policy becomes clear over time and individuals have the opportunity to revisit prior beliefs, even intense political polarization can be attenuated
Evaluating the in vitro potential of natural extracts to protect lipids from oxidative damage
Lipid peroxidation is a chemical reaction known to have negative impacts on living organisms’ health and on consumer products’ quality and safety. Therefore, it has been the subject of extensive scientific research concerning the possibilities to reduce it, both in vivo and in nonliving organic matrices. It can be started by a variety of oxidants, by both ROS-dependent and -independent pathways, all of them reviewed in this document. Another feature of this reaction is the capacity
of lipid peroxyl radicals to react with the non-oxidized lipids, propagating the reaction even in the
absence of an external trigger. Due to these specificities of lipid peroxidation, regular antioxidant
strategies—although being helpful in controlling oxidative triggers—are not tailored to tackle this
challenge. Thus, more suited antioxidant compounds or technologies are required and sought after
by researchers, either in the fields of medicine and physiology, or in product development and
biotechnology. Despite the existence of several laboratory procedures associated with the study of
lipid peroxidation, a methodology to perform bioprospecting of natural products to prevent lipid
peroxidation (a Lipid Peroxidation Inhibitory Potential assay, LPIP) is not yet well established. In this
review, a critical look into the possibility of testing the capacity of natural products to inhibit lipid
peroxidation is presented. In vitro systems used to peroxidize a lipid sample are also reviewed on
the basis of lipid substrate origin, and, for each of them, procedural insights, oxidation initiation
strategies, and lipid peroxidation extent monitoring are discussed.info:eu-repo/semantics/publishedVersio
Dystrophic calcification vs sialolithiasis in a pediactric parotid gland : a case report
Calcinosis is a connective tissue disorder characterized by ectopic calcification in soft tissues. It is subdivided into: dystrophic, metastatic, idiopathic and iatrogenic calcification. The formation of mineralized material in the salivary glands is a common finding in the daily practice of dentists and other specialists. In most cases, this calcification is a sialolith. However, a type of ectopic calcification termed dystrophic calcification is characterized by inappropriate biomineralization in soft tissues and may be associated with trauma, chronic and localized infection or inflammatory diseases. We report a case of a 9-year-old female patient who complained of small nodules in the left parotid region, which begun two years before. Her main complaint was of recurring periods of worsened symptoms characterized by the exacerbation and symptomatic remission of the gland volume with occasional otolaryngologic infections. This study aims to discuss ectopic dystrophic calcification in the parotid gland associated with recurrent infection in children
Bayesian additive regression trees with model trees
Bayesian additive regression trees (BART) is a tree-based machine learning method that has been successfully applied to
regression and classification problems. BART assumes regularisation priors on a set of trees that work as weak learners
and is very flexible for predicting in the presence of nonlinearity and high-order interactions. In this paper, we introduce
an extension of BART, called model trees BART (MOTR-BART), that considers piecewise linear functions at node levels
instead of piecewise constants. In MOTR-BART, rather than having a unique value at node level for the prediction, a linear
predictor is estimated considering the covariates that have been used as the split variables in the corresponding tree. In our
approach, local linearities are captured more efficiently and fewer trees are required to achieve equal or better performance
than BART. Via simulation studies and real data applications, we compare MOTR-BART to its main competitors. R code for
MOTR-BART implementation is available at https://github.com/ebprado/MOTR-BART
Discussion of: "Bayesian Regression Tree Models for Causal Inference: Regularization, Confounding, and Heterogeneous Effects"
Contributed discussion included in P. Richard Hahn. Jared S. Murray. Carlos M. Carvalho. "Bayesian Regression Tree Models for Causal Inference: Regularization, Confounding, and Heterogeneous Effects (with Discussion)." Bayesian Anal. 15 (3) 965 - 1056, September 2020. https://doi.org/10.1214/19-BA119
Agricultural intensification can help protect the Amazon Forest and reduce global warming / Protecting the Amazon forest and reducing global warming via agricultural intensification
The Amazon basin includes 550 M ha covered with rainforests, with 60% of this area being in Brazil. Conversion of rainforest for soybean production raises concerns about the degree to which Brazil can reconcile production and environmental goals. Here we investigated the degree to which intensification could help Brazil produce more soybean without further encroachment of the Amazon Forest. Our analysis shows that continuation of current trends in soybean yield and area would lead to conversion of additional 5.7 M ha of forests and savannas during the next 15 years, with an associated 2550 Mt of CO2eq released into the atmosphere. In contrast, acceleration of yield improvement, coupled with expansion of soybean area only in areas currently used for livestock production, would allow Brazil to achieve similar economic benefits without deforestation and with substantially lower global climate warming
Anti-tumor efficiency of Perillylalcohol/β-Cyclodextrin inclusion complexes in a sarcoma S180-induced mice model
The low solubility and high volatility of perillyl alcohol (POH) compromise its bioavailability and potential use as chemotherapeutic drug. In this work, we have evaluated the anticancer activity of POH complexed with -cyclodextrin (-CD) using three complexation approaches. Molecular docking suggests the hydrogen-bond between POH and -cyclodextrin in molar proportion was 1:1. Thermal analysis and Fourier-transform infrared spectroscopy (FTIR) confirmed that the POH was enclosed in the -CD cavity. Also, there was a significant reduction of particle size thereof, indicating a modification of the -cyclodextrin crystals. The complexes were tested against human L929 fibroblasts after 24 h of incubation showing no signs of cytotoxicity. Concerning the histopathological results, the treatment with POH/-CD at a dose of 50 mg/kg promoted approximately 60% inhibition of tumor growth in a sarcoma S180-induced mice model and the reduction of nuclear immunoexpression of the Ki67 antigen compared to the control group. Obtained data suggest a significant reduction of cycling cells and tumor proliferation. Our results confirm that complexation of POH/-CD not only solves the problem related to the volatility of the monoterpene but also increases its efficiency as an antitumor agent.This work was supported by the Banco do Nordeste (grant FUNDECI/2016.0015), Conselho
Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Fundação de Apoio à Pesquisa e
à Inovação Tecnológica do Estado de Sergipe (Fapitec) and Coordenação de Aperfeiçoamento de
Pessoal de Nível Superior (CAPES). Eliana B. Souto would like to acknowledge the Portuguese
Science and Technology Foundation (FCT/MCT) and from European Funds (PRODER/COMPETE)
for the project UIDB/04469/2020 (strategic fund), co-financed by FEDER, under the Partnership
Agreement PT2020.info:eu-repo/semantics/publishedVersio
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