Resultados de pesquisa obtidos na cultura do algodão nos cerrados da região Meio-Norte do Brasil no período de 1999 a 2008.

O objetivo deste trabalho é informar aos produtores de algodão da região Meio-Norte do Brasil sobre os resultados de pesquisa obtidos no período de 1999 a 2008. Nesse período foram conduzidos 91 experimentos de avaliação de genótipos visando a introdução da cultura algodoeira como uma alternativa para a rotação com as culturas de soja e milho. No Piauí, os trabalhos de pesquisa foram realizados nos municípios de Teresina, Bom Jesus, Uruçuí, Palmeira do Piauí e Baixa Grande do Ribeiro e, no Maranhão, nos municípios de Tasso Fragoso, Sambaíba, São Raimundo das Mangabeiras, Chapadinha, Brejo, Anapurus e Mata Roma. A amplitude para produtividade média de algodão em caroço variou de 2.628 kg ha-1 a 3.598 kg/ha-1 , no Piauí e, de 2.522 kg/ha-1 a 3.360 kg/ha-1, no Maranhão. No Piauí, os municípios de Baixa Grande do Ribeiro e Uruçuí apresentaram as maiores produtividades com uma amplitude de variação de 3.254 kg/ha-1 a 4.356 kg/ha-1 e 2.730 kg/ha-1 a 3.419 kg/ha-1, respectivamente. No Maranhão as melhores produtividades ocorreram nos municípios de Tasso Fragoso com uma amplitude de variação de 2.751 kg/ha-1 a 4.236 kg/ha-1 e, em São Raimundo das Mangabeiras com uma amplitude de variação de 3.313 kg/ha-1 a 3.943 kg/ha-1

Avaliação agroeconômica do sistema de produção do consórcio mamona e feijão-caupi.

O trabalho teve como objetivo avaliar a viabilidade agroeconômica do sistema de produção do consórcio mamona e feijão-caupi. O trabalho foi conduzido em campo na safra 2004/2005 em condições de sequeiro, nos municípios de Teresina, Anísio de Abreu e São Raimundo Nonato, PI, nos meses de março, Janeiro e fevereiro, respectivamente. A unidade experimental, em cada local, foi formada por um hectare do consórcio mamona com feijão-caupi. Houve variação nas produtividades de bagas de mamona, entre os três locais (800 kg ha-1 em Teresina, 1.300 kg ha-1 em Anísio de Abreu e 1.500 kg ha-1 em São Raimundo Nonato), mostrando que o ambiente tem grande influencia sobre este caráter. Em termos econômicos, o custo variável total, por hectare, foi de R$1.249,60, para os três municípios, com receitas líquidas de R$ 432,40, R$869,40 e R$997,40, resultando em uma relação benefício/custo de 0,35; 0,70 e 0,80, em Teresina, Anísio de Abreu e São Raimundo Nonato, respectivamente. Esta relação indica um retorno líquido de R$0,35 (trinta e cinco centavos), R$0,70 (setenta centavos) e R$0,80 (oitenta centavos) para cada real investido. A receita obtida com a comercialização do feijão-caupi foi suficiente para cobrir o custo variável total do sistema de consórcio da mamona com feijão-caupi, restando à produção da mamona como renda líquida

Lipid nanocarriers for anti-HIV therapeutics: a focus on physicochemical properties and biotechnological advances

Since HIV was first identified, and in a relatively short period of time, AIDS has become one of the most devastating infectious diseases of the 21st century. Classical antiretroviral therapies were a major step forward in disease treatment options, significantly improving the survival rates of HIV-infected individuals. Even though these therapies have greatly improved HIV clinical outcomes, antiretrovirals (ARV) feature biopharmaceutic and pharmacokinetic problems such as poor aqueous solubility, short half-life, and poor penetration into HIV reservoir sites, which contribute to the suboptimal efficacy of these regimens. To overcome some of these issues, novel nanotechnology-based strategies for ARV delivery towards HIV viral reservoirs have been proposed. The current review is focused on the benefits of using lipid-based nanocarriers for tuning the physicochemical properties of ARV to overcome biological barriers upon administration. Furthermore, a correlation between these properties and the potential therapeutic outcomes has been established. Biotechnological advancements using lipid nanocarriers for RNA interference (RNAi) delivery for the treatment of HIV infections were also discussed.This research was funded by FCT/MCTES—Foundation for Science and Technology I.P. from the Minister of Science, Technology, and Higher Education (PIDDAC) and European Regional Development Fund (ERDF) by the COMPETE—Programa Operacional Factores de Competitividade (POFC) through the project CONCERT [POCI-01-0145-FEDER-032651 and PTDC/NANMAT/326512017] and the Strategic Funding UID/FIS/04650/2019 and “Contrato-Programa” UIDB/ 04469/2020 (CF-UM-UP and CBMA). Marlene Lúcio thanks FCT and ERDF for the doctoral position [CTTI-150/18-CF (1)] in the scope of the project CONCERT. Maria João Faria thanks FCT for PhD grant [2020.06561.BD]

Flashing LEDs for microalgal production

Flashing lights are next-generation tools to mitigate light attenuation and increase the photosynthetic efficiency of microalgal cultivation systems illuminated by light-emitting diodes (LEDs). Optimal flashing light conditions depend on the reaction kinetics and properties of the linear electron transfer chain, energy dissipation, and storage mechanisms of a phototroph. In particular, extremely short and intense light flashes potentially mitigate light attenuation in photobioreactors without impairing photosynthesis. Intelligently controlling flashing light units and selecting electronic components can maximize light emission and energy efficiency. We discuss the biological, physical, and technical properties of flashing lights for algal production. We combine recent findings about photosynthetic pathways, self-shading in photobioreactors, and developments in solid-state technology towards the biotechnological application of LEDs to microalgal production.Foundation for Science and Technology (FCT, Portugal) [CCMAR/Multi/04326/2013]Nord UniversityNordland County Government (project Bioteknologi en framtidsrettet naering)INTERREG V-A Espana-Portugal project [0055 ALGARED + 5E]Portuguese Foundation for Science and Technology [SFRH/BD/105541/2014, SFRH/BD/115325/2016]info:eu-repo/semantics/publishedVersio

Organizações mais socialmente responsáveis, mais éticas, mais atrativas como futuras empregadoras? Contributos do desempenho social e da reputação ética para a atração de futuros trabalhadores

Previous studies suggest that the corporate social performance of organizations influences their attractiveness as a workplace. This study analyzed additional variables that may help explain this relationship. In this context, an ethical reputation is a construct positively related to corporate social responsibility (CSR). In the research, CSR perception was manipulated in order to observe its effect on organizational attractiveness through the mediating effect of ethical reputation. Participants (n = 260) were randomly subjected to two experimental conditions by responding to an electronic questionnaire containing the description of an organization that implements (i.e., the high involvement condition) or not (i.e., the low involvement condition) a set of CSR practices. This was followed by questions about other variables of interest. The results show that the proposed theoretical model provides a strong fit to the data, thus empirically supporting the proposal that CSR directly and indirectly affects, through ethical reputation, evaluations of organizations as a future workplace. In practical terms, this means that, in the war for talent, organizations can use information about their corporate social performance and ethical reputation to attract potential candidates, alongside more traditional information on organizational attributes and job characteristics.info:eu-repo/semantics/publishedVersio

Colloidal approach for the design of Ti powders sinterable at low temperature

The colloid-chemistry control of metallic powders in aqueous slurries is proposed as a way to produce spherical granules of fine titanium particles able to be processed by powder metallurgy (PM) techniques. Significant improvement of sintering behavior is achieved, leading to high dense parts at reduced sintering temperature and time. Consequently the control of grain growth during sintering was achieved, as well as the oxygen content. This approach can be extended to other strategies for Ti design, such as the homogeneous dispersion of second phases for further control of grain size and modification of properties.The authors would like to acknowledge the financial support from Spanish Government through the projects MAT 2009-14448-C02-01 and 02, MAT2012-38650-C02-01 and 02En prens

Improvement of sintering behaviour of titanium by colloidal techniques

The conventional sintering of titanium requires high temperatures to obtain high densities and low porosity, giving rise to microstructures with high grain size, and high interstitial contents, both of which adversely affect the mechanical properties obtained. A novel approach is reported which uses fine (10 µm) spherical Ti powder to improve the sintering behaviour, together with a small percentage of alumina particles (0·5 µm) to restrict grain growth. Colloidal techniques were used to form spherical agglomerates, 50‐300 µm in size, of Ti powder with alumina particles dispersed homogenously on the Ti surface. These agglomerates present good compressibility and make it possible to sinter effectively at low temperatures, increasing the relative density and decreasing grain sizeThe authors acknowledgement the financial support from Spanish Ministry of Science and Innovation through projects MAT 2009-14448-C01, and MAT 2009-14448-C02. This is an edited version of a presentation at Euro PM 2012, organised by EPMA in Basel, Switzerland on 16–19 October 2012.Publicad

Detecting early mealybug infestation stages on tomato plants using optical spectroscopy

Mealybugs (Hemiptera: Pseudococcidae) are important pests in agricultural and ornamental crops, including the tomato. Damage by mealybugs is characterized by a reduction in plant photosynthesis and growth due to sap feeding and also, as a result of honeydew excretion, from sooty mould development and virus transmission. The effectiveness of mealybug control strategies, including the application of insecticides and biological control, depends on the ability to detect the infestation at an early stage. Monitoring by visual observation is not very effective and is time-consuming. Optical spectroscopy represents a potential tool for detecting plant biotic stresses, including that caused by insect pests. In this study, we tested the feasibility of using optical spectroscopy for the early detection of mealybug infestation of tomato plants. An experiment was carried out using potted plants under field conditions, with 15 replicates per treatment and a randomised design. Two treatments were considered: 1) infested plants inoculated with three mealybug egg masses; and 2) control plants without mealybugs. The distance between pots was kept at 80 cm and the plants were frequently inspected to ensure control plants were not infested with mealybugs. The following parameters were recorded weekly over 5 weeks for each plant: 1) reflectance of marked leaves was measured with a USB4000 spectrometer across the wavelength 400-1,000 nm; 2) plant height; 3) leaf size; 4) mealybug density; and 5) presence and density of other pests. Results of principal component analysis (PCA) second derivative of the leaf reflectance showed a clear distinction between control and infested plants and a separation of components in the near infrared (NIR) region on the last day of the analysis (57 days). The reduction in absorption in the NIR region may be due to an increase in the quantity of air spaces within the leaf's mesophyll, changing the spatial distribution of the leaves' refractive index and, as a consequence, the light scattering contribution to the reflectance spectra. When tracking the evolution of the leaves' absorbance, infested leaves relative to control leaves had a tendency over time to have reduced absorbance in photosystem II and NIR plateau wavelengths. The evolution over time of the reflectance of analysed leaves at each wavelength fitted a quadratic curve, the coefficients of which discriminated between infested and control plants. This methodology has the potential to provide an objective measure of the degree of infestation by pests and the potential impact on the crop.FCT - Foundation for Science and Technology, PortugalCentre for Electronics, Optoelectronics and Telecommunications (CEOT) [UID/Multi/00631/2013