66 research outputs found
Why Airborne Pesticides Are So Dangerous
More than four billion of tons of pesticides are used annually in agriculture worldwide. Part of it drifts down after pulverization, but a volatilized portion moves upwards. Pulverized pesticide applications are controlled by different parameters of fan and climate conditions. This can be mitigated with buffer zones, hedgerows and forest strips. Volatilization is determined by physicochemical parameters of the product and adsorption capacity to soils and leaves, and climate conditions. Prevention is the only efficient approach by banning high vapor pressure active ingredients. Volatilized pesticides are transported by air streams. Subsequently products are retained by mountains or eventually moved further by wind and descend in rain returning them to soil or vegetation. All regions of the planet are submitted to air pollution and nowadays pristine environments are very rare. These pollutants have hazardous effects on environment and toxic effects to skin and when they reach the blood stream directly via the lungs, are more intense to humans than from ingestion. The challenge of this overview highlights sustainability to avoid airborne pesticides by different strategies such as reduction of amounts sprayed through integrated pest management and mainly replacement of hazardous chemical pesticides by harmless ones or by biological control
Vidrios biomédicos y vitrocerámicas como sustitutos de los tejidos óseos
Nowadays, an important research topic related with medical devices are the materials designed as bone tissues substitutes. Hard tissues have a great capacity of self-regeneration but in front of traumatic or pathologic critical bone defects it is necessary the use of bone substitutes or templates as temporal or permanent grafts. Glasses or glass-ceramics are osteoconductive, osteoinductive and biocompatible materials. In addition, they have the ability to link directly to the living bone tissues without any interface (bioactivity). Also, it has been reported that bioglasses favor the angiogenesis process and the cellular adhesion, proliferation and differentiation necessary features for bone tissue engineering scaffolds. This work refers generalities of the bioactive glasses and glass-ceramics compositions, manufacture processes, properties, advantages, disadvantages as well as the main clinical applications and new developments for tissue engineering
Cultivo inicial in vitro de gemas axilares de Ananas comosus (L.) Merr., em meio líquido/sólido, na presença/ausência de luz
Tecnologia e administração de recursos humanos: uma análise crítica da implantação de sistemas integrados de gestão em uma cooperativa agro-industrial
Concentrações de sais do meio Knudson C e de ácido giberélico no crescimento in vitro de plântulas de orquídea
Digestibilidade de dietas contendo resíduo úmido de mandioca em substituição ao milho para tourinhos em terminação
Taxa de multiplicação e efeito residual de diferentes fontes de citocinina no cultivo in vitro de Hancornia speciosa Gomes
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