Benefícios da adubação verde sobre a simbiose micorrízica e a produtividade de batata-doce.

Plantio das leguminosas e da batata doce. Produtividade da batata doce e simbiose micorrízica.bitstream/CNPAB-2010/27139/1/cot014.pd

Presence and Function of Dopamine Transporter (DAT) in Stallion Sperm : Dopamine Modulates Sperm Motility and Acrosomal Integrity

Dopamine is a catecholamine with multiple physiological functions, playing a key role in nervous system; however its participation in reproductive processes and sperm physiology is controversial. High dopamine concentrations have been reported in different portions of the feminine and masculine reproductive tract, although the role fulfilled by this catecholamine in reproductive physiology is as yet unknown. We have previously shown that dopamine type 2 receptor is functional in boar sperm, suggesting that dopamine acts as a physiological modulator of sperm viability, capacitation and motility. In the present study, using immunodetection methods, we revealed the presence of several proteins important for the dopamine uptake and signalling in mammalian sperm, specifically monoamine transporters as dopamine (DAT), serotonin (SERT) and norepinephrine (NET) transporters in equine sperm. We also demonstrated for the first time in equine sperm a functional dopamine transporter using 4-[4-(Dimethylamino)styryl]-N-methylpyridinium iodide (ASP+ ), as substrate. In addition, we also showed that dopamine (1 mM) treatment in vitro, does not affect sperm viability but decreases total and progressive sperm motility. This effect is reversed by blocking the dopamine transporter with the selective inhibitor vanoxerine (GBR12909) and non-selective inhibitors of dopamine reuptake such as nomifensine and bupropion. The effect of dopamine in sperm physiology was evaluated and we demonstrated that acrosome integrity and thyrosine phosphorylation in equine sperm is significantly reduced at high concentrations of this catecholamine. In summary, our results revealed the presence of monoamine transporter DAT, NET and SERT in equine sperm, and that the dopamine uptake by DAT can regulate sperm function, specifically acrosomal integrity and sperm motility

3-D Ultrasound Localization Microscopy for Identifying Microvascular Morphology Features of Tumor Angiogenesis at a Resolution Beyond the Diffraction Limit of Conventional Ultrasound

Angiogenesis has been known as a hallmark of solid tumor cancers for decades, yet ultrasound has been limited in its ability to detect the microvascular changes associated with malignancy. Here, we demonstrate the potential of 'ultrasound localization microscopy' applied volumetrically in combination with quantitative analysis of microvascular morphology, as an approach to overcome this limitation. This pilot study demonstrates our ability to image complex microvascular patterns associated with tumor angiogenesis in-vivo at a resolution of tens of microns - substantially better than the diffraction limit of traditional clinical ultrasound, yet using an 8 MHz clinical ultrasound probe. Furthermore, it is observed that data from healthy and tumor-bearing tissue exhibit significant differences in microvascular pattern and density. Results suggests that with continued development of these novel technologies, ultrasound has the potential to detect biomarkers of cancer based on the microvascular 'fingerprint' of malignant angiogenesis rather than through imaging of blood flow dynamics or the tumor mass itself

Risks to pollinators and pollination from invasive alien species

Invasive alien species modify pollinator biodiversity and the services they provide that underpin ecosystem function and human well-being. Building on the Intergovernmental Science-Policy Platform for Biodiversity and Ecosystem Services (IPBES) global assessment of pollinators and pollination, we synthesize current understanding of invasive alien impacts on pollinators and pollination. Invasive alien species create risks and opportunities for pollinator nutrition, re-organize species interactions to affect native pollination and community stability, and spread and select for virulent diseases. Risks are complex but substantial, and depend greatly on the ecological function and evolutionary history of both the invader and the recipient ecosystem. We highlight evolutionary implications for pollination from invasive alien species, and identify future research directions, key messages and options for decision-making

Cooperação e diplomacia hídrica: A contribuição das águas compartilhadas para a cooperação regional

A água tem papel vital para a vida humana e múltiplos usos. Sua ocorrência não se limita às fronteiras políticas dos países, o que leva ao fato de que quase metade da superfície terrestre é abarcada por águas transfronteiriças na forma de rios, lagos e águas subterrâneas. Dado seu caráter transfronteiriço, a gestão, o planejamento e o compartilhamento são desafios complexos para as nações ribeirinhas. Tensões sociais, econômicas e políticas emergem facilmente neste cenário, que abrange questões de qualidade, quantidade e alocação dos recursos hídricos, e mostram que as discussões relacionadas à água são intrinsecamente políticas por natureza. Também mostram que a cooperação e o conflito hídrico coexistem em um continuum nessas relações. Levando em consideração o aumento da demanda por água, argumenta-se que é preciso que haja arranjos cooperativos entre os países ribeirinhos para garantir a sustentabilidade, resiliência e uso equânime das águas compartilhadas. Visando prevenir conflitos, administrar tensões e promover o desenvolvimento sustentável das águas transfronteiriças, defende-se a difusão da cooperação hídrica transfronteiriça e a diplomacia da água para as regiões abarcadas por bacias, rios, lagos ou águas subterrâneas transfronteiriças. Por meio de uma abordagem multidisciplinar e utilizando-se de conceitos das relações internacionais, ciência política, direito e geografia, esse artigo fornecerá uma compreensão teórica acerca da cooperação hídrica transfronteiriça e da diplomacia da água. Objetiva-se contribuir para o estabelecimento, desenvolvimento e avanço de arranjos cooperativos mais justos, fortes, inclusivos, eficazes e eficientes para as águas transfronteiriças

Impacto de la pandemia de COVID-19 en las empresas mexicanas, el desempleo resultante y los emprendimientos por necesidad

En esta investigación se identificaron algunas características que deben tener los emprendimientos para asegurar que tendrán mayores posibilidades de permanecer y que constituyan fuentes de empleo para otras personas además de los fundadores. Estos temas se abordan en tres apartados: I. Cambios, afectaciones y muerte de las empresas a causa del COVID-19, II. El efecto de la emergencia sanitaria en la pérdida de empleos y III. Análisis del emprendimiento frente al desempleo generado por la pandemia de COVID-1

The use of gene expression to unravel the single and mixture toxicity of abamectin and difenoconazole on survival and reproduction of the springtail Folsomia candida

Pesticides risk assessments have traditionally focused on the effects on standard parameters, such as mortality, reproduction and development. However, one of the first signs of adverse effects that occur in organisms exposed to stress conditions is an alteration in their genomic expression, which is specific to the type of stress, sensitive to very low contaminant concentrations and responsive in a few hours. The aim of the present study was to evaluate the single and binary mixture toxicity of commercial products of abamectin (Kraft® 36 EC) and difenoconazole (Score® 250 EC) to Folsomia candida. Laboratory toxicity tests were conducted to access the effects of these pesticides on springtail survival, reproduction and gene expression. The reproduction assays gave EC50 and EC10 values, respectively, of 6.3 and 1.4 mg a.s./kg dry soil for abamectin; 1.0 and 0.12 mg a.s./kg dry soil for Kraft® 36 EC; and 54 and 23 mg a.s./kg dry soil for Score® 250 EC. Technical difenoconazole did not have any effect at the concentrations tested. No significant differences in gene expression were found between the abamectin concentrations tested (EC10 and EC50) and the solvent control. Exposure to Kraft® 36 EC, however, significantly induced Cyp6 expression at the EC50 level, while VgR was significantly downregulated at both the EC10 and EC50. Exposure to the simple pesticide mixture of Kraft® 36 EC + Score® 250 EC caused significant up regulation of ABC transporter, and significant down regulation of VgR relative to the controls. GABA receptor also showed significant down-regulation between the EC10 and EC50 mixture treatments. Results of the present study demonstrate that pesticide-induced gene expression effects precede and occur at lower concentrations than organism-level responses. Integrating "omic" endpoints in traditional bioassays may thus be a promising way forward in pesticide toxicity evaluations