Publications by authors named "Joao V Silva"

Yield gap analysis is used to characterize the untapped production potential of cropping systems. With emerging large-n agronomic datasets and data science methods, pathways for narrowing yield gaps can be identified that provide actionable insights into where and how cropping systems can be sustainably intensified. Here we characterize the contributing factors to rice yield gaps across seven Indian states, with a case study region used to assess the power of intervention targeting.

View Article and Find Full Text PDF

The use of carbon nanotubes (CNTs), which are nanometric materials, in pathogen detection, protection of environments, food safety, and in the diagnosis and treatment of diseases, as efficient drug delivery systems, is relevant for the improvement and advancement of pharmacological profiles of many molecules employed in therapeutics and in tissue bioengineering. It has contributed to the advancement of science due to the development of new tools and devices in the field of medicine. CNTs have versatile mechanical, physical, and chemical properties, in addition to their great potential for association with other materials to contribute to applications in different fields of medicine.

View Article and Find Full Text PDF
Article Synopsis
  • Sustainable agricultural practices, especially conservation agriculture, have been slow to adopt in southern Africa despite being promoted for nearly 30 years, prompting a need to explore behavioral factors influencing this trend.
  • Research in Zambia reveals that a small percentage of smallholders (12% impatient and 18% risk averse) exhibit traits that negatively affect their adoption of various conservation methods.
  • The study indicates that impatience and risk aversion lead to lower likelihoods and intensity of adopting practices like minimum tillage and mulching, suggesting the need for risk management tools, such as crop yield insurance, to encourage sustainable farming practices.
View Article and Find Full Text PDF

Context And Results: Flavivirus diseases' cycles, especially Dengue and Yellow Fever, can be observed all over Brazilian territory, representing a great health concern. Additionally, there are no drugs available in therapy. In this scenario, in silico methodologies were applied to obtain physicochemical properties, as well as to better understand the ligand-biological target interaction mode of 20 previously reported NS2B/NS3 protease inhibitors of Dengue virus.

View Article and Find Full Text PDF

Context: Collection and analysis of large volumes of on-farm production data are widely seen as key to understanding yield variability among farmers and improving resource-use efficiency.

Objective: The aim of this study was to assess the performance of statistical and machine learning methods to explain and predict crop yield across thousands of farmers' fields in contrasting farming systems worldwide.

Methods: A large database of 10,940 field-year combinations from three countries in different stages of agricultural intensification was analyzed.

View Article and Find Full Text PDF

Hyperprolactinemia is a pathological condition resulting from increased prolactin that directly affects reproduction, as this condition inhibits the release of LH, FSH and gonadal steroidogenesis, bringing several negative clinical associations in reproduction. In contrast, melatonin (MEL) plays an important role in the regulation of steroidogenesis and modulates damages to the process of spermatogenesis. The objective was to analyze the protective effects of exogenous melatonin on the testis of hyperprolactinemic adult rats.

View Article and Find Full Text PDF

A growing urban population and dietary changes increased wheat import bills in Africa to 9% per year. Though wheat production in the continent has been increasing over the past decades, to varying degrees depending on regions, this has not been commensurate with the rapidly increasing demand for wheat. Analyses of wheat yield gaps show that there is ample opportunity to increase wheat production in Africa through improved genetics and agronomic practices.

View Article and Find Full Text PDF

Acid tropical soils may become more productive when treated with agricultural lime, but optimal lime rates have yet to be determined in many tropical regions. In these regions, lime rates can be estimated with lime requirement models based on widely available soil data. We reviewed seven of these models and introduced a new model (LiTAS).

View Article and Find Full Text PDF

Background: Arylindole derivatives are promising scaffolds in the design of new drugs. These scaffolds exhibit a wide biological activity, including inhibition of COX-2, antitumor activity, receptor GABA agonism, and estrogen receptor modulation.

Objectives: Taking this into account, this paper presents a study to understand the inhibitory action of certain 2-arylindole derivatives, specifically a series of 2,3-diarylindoles with IC values from 0.

View Article and Find Full Text PDF

Background: Zika fever affects poor and vulnerable populations, presenting cycles observed in, at least 86 countries, with no vaccine prevention or treatment available. It is known that the genus Flavivirus causes Zika Virus (ZIKV), as Dengue and Yellow Fever, whose genetic material decodes, among other proteins, a series of non-structural (NS) proteins essential for viral replication, such as NS2B-NS3 protease. Additionally, chemical and biological systems are commonly studied using molecular modeling approaches allowing, among several other processes, to elucidate mechanisms of action, molecule reactivity and/or chemical properties and the design of new drugs.

View Article and Find Full Text PDF

Unlabelled: Cumulative crop recovery of synthetic fertiliser nitrogen (N) over several cropping seasons (legacy effect) generally receives limited attention. The increment in crop N uptake after the first-season uptake from fertiliser can be expressed as a fraction (∆RE) of the annual N application rate. This study aims to quantify ∆RE using data from nine long-term experiments (LTEs).

View Article and Find Full Text PDF

Neglected Tropical Diseases (NTDs) and infectious illnesses, such as malaria, tuberculosis and Zika fever, represent a major public health concern in many countries and regions worldwide, especially in developing ones. They cause thousands of deaths per year, and certainly compromise the life of affected patients. The drugs available for therapy are toxic, have considerable adverse effects, and are obsolete, especially with respect to resistance.

View Article and Find Full Text PDF

Adequate tools for evaluating sustainable intensification (SI) of crop production for agro-hydrological system are not readily available. Building on existing concepts, we propose a framework for evaluating SI at the field and river basin levels. The framework serves as a means to assess and visualise SI indicator values, including yield, water-use efficiency and nitrogen-use efficiency (NUE), alongside water and nitrogen surpluses and their effects on water quantity and quality.

View Article and Find Full Text PDF

Dendrimers are globular structures, presenting an initiator core, repetitive layers starting radially from the core and terminal groups on the surface, resembling tree architecture. These structures have been studied in many biological applications, as drug, DNA, RNA and proteins delivery, as well as imaging and radiocontrast agents. With reference to that, this review focused in providing examples of dendrimers used in nanomedicine.

View Article and Find Full Text PDF

The design of compounds with directed action to a defined organ or tissue is a very promising approach, since it can decrease considerably the toxicity of the drug/bioactive compound. For this reason, this kind of strategy has been greatly important in the scientific community. Dendrimers, on the other hand, comprise extremely organized macromolecules with many peripheral functionalities, stepwise controlled synthesis, and defined size.

View Article and Find Full Text PDF

Few tools are available for noninvasive imaging of synapses in the living mammalian brain. Current paradigms require the use of genetically modified mice or viral delivery of genetic material to the brain. To develop an alternative chemical approach, utilizing the recognition of synaptic components by organic small molecules, we designed an imaging-based, high-content screen in cultured cortical neurons to identify molecules based on their colocalization with fluorescently tagged synaptic proteins.

View Article and Find Full Text PDF
Article Synopsis
  • - This study investigated the effectiveness of an ethanol extract and its fractions from a plant against leishmania parasites, focusing on their toxicity levels and selectivity index.
  • - The ethanol extract was made by soaking powdered stems and was further separated into fractions; lapachol was extracted and purified for testing.
  • - Results showed that the ethyl acetate fraction had activity against promastigotes without being toxic, while lapachol was selectively effective against amastigotes, indicating potential for future treatments.
View Article and Find Full Text PDF
Article Synopsis
  • The study focuses on the use of traditional plant species, particularly copaiba oil, for treating wounds and leishmaniasis, highlighting its traditional applications in Amazonian medicine.
  • Phytochemical analyses reveal that copaiba oil contains beneficial compounds like diterpenes and sesquiterpenes, which exhibit leishmanicidal properties, especially against the amastigote form of the parasite.
  • The oil demonstrates low toxicity and the potential to enhance healing and modulate immune responses, making it a promising candidate for leishmaniasis treatment.
View Article and Find Full Text PDF

Infrared fundamental vibrational intensities and quantum theory atoms in molecules (QTAIM) charge-charge flux-dipole flux (CCFDF) contributions to the polar tensors of the fluorochloromethanes have been calculated at the QCISD/cc-pVTZ level. A root-mean-square error of 20.0 km mol(-1) has been found compared to an experimental error estimate of 14.

View Article and Find Full Text PDF

The infrared fundamental intensities of benzene and hexafluorobenzene have been calculated at the MP2/6-311++G(3d,3p) level. The theoretical values are in excellent agreement with the averaged experimental C(6)H(6) results having a rms error of 15.3 km mol(-1).

View Article and Find Full Text PDF

The molecular dipole moments, their derivatives, and the fundamental IR intensities of the X2CY (X = H, F, Cl; Y = O, S) molecules are determined from QTAIM atomic charges and dipoles and their fluxes at the MP2/6-311++G(3d,3p) level. Root-mean-square errors of +/-0.03 D and +/-1.

View Article and Find Full Text PDF

A quantum theory of atoms in molecules (QTAIM) charge-charge flux-dipole flux (CCFDF) decomposition of the MP2/6-311++G(3d,3p) level molecular dipole moment derivatives is reported for the cis-, trans-, and 1,1-difluoroethylenes and the cis- and trans-dichloroethylenes. Although the dipole moment derivatives and infrared fundamental intensities calculated at the MP2 level are overestimated for high-intensity bands corresponding to CF and CC stretching vibrations, the overall agreement is good with a root-mean-square (rms) error of 19.6 km mol-1 for intensities ranging from 0 to 217.

View Article and Find Full Text PDF

The molecular dipole moments, their derivatives, and the fundamental IR intensities of the fluoro-, chloro-, and fluorochloromethanes are determined from QTAIM atomic charges and dipoles and their fluxes at the MP2/6-311++G(3d,3p) level. Root-mean-square (rms) errors of 0.01 D and 5.

View Article and Find Full Text PDF