Melatonin bioengineered: A New Possible Strategy for Treatment of Breast Cancer

Breast cancer is an important public health problem, with an estimated 3.2 million new cases by the year 2050. Diet plays a key role in the etiology of breast cancer and breastfeeding is associated with a lower incidence of breast cancer. On the other hand, the improvement of the therapeutic properties of bioactive compounds through their incorporation into microcarriers is an important strategy in obtaining new therapies, since cyclical changes in concentration are eliminated; there is biological availability of the compound as well as the reduction in toxicity, number dose and suppression of adverse reactions. Studies using hormones such as melatonin extracted from human milk adsorbed onto polyethylene glycol (PEG) microspheres showed that the controlled release of this compound was able to reduce viability and induce apoptosis in MCF-7 cell lines. Colostrum differs from most of the secretions because it contains viable leukocytes during the first days of lactation with a quantity and activity comparable to blood leukocytes, and has several defense components such as antibodies and hormones, such as melatonin (MLT). This review details the influence of the soluble and cellular components present in human colostrum, such as the MLT hormone, as the modified release systems influence the action of MLT and the possible mechanisms involved that contribute to the hypothesis of reduction of breast cancer in women who breastfed

Dinâmica de rizóbios em solo do cerrado de Roraima durante o período de estiagem.

RESUMO: A fixação biológica de nitrogênio que ocorre em leguminosas é realizada por um grupo de bactérias conhecidas como rizóbios. A sobrevivência destas bactérias no solo é influenciada por diversos fatores como a temperatura, umidade e fertilidade do solo. O objetivo deste trabalho foi avaliar a dinâmica da população de rizóbios em solo após o cultivo de soja, durante o período de estiagem no cerrado de Roraima. Foram amostradas três áreas: i) cerrado nativo como referência; ii) área cultivada uma vez com soja inoculada com rizóbio; iii) e área cultivada duas vezes com soja inoculada com rizóbio em anos consecutivos. O solo foi coletado na profundidade de 0-10 cm em cinco períodos a partir do inicio da estiagem no mês de setembro de 2006 coincidindo com a época de colheita da soja e prolongando-se até março de 2007 (0, 45, 90, 135 e 180 dias). A população de rizóbios no solo foi avaliada pela técnica do número mais provável (NMP) utilizando plantas de soja e de feijão-caupi como espécies isca. Foi observado que na área nativa praticamente não existiam bactérias nodulantes de soja, mas havia uma população capaz de nodular o feijão-caupi de até algumas centenas de rizóbios por gramas de solo. O cultivo da soja utilizando sementes inoculadas elevou a população de rizóbios no solo que foi constatada por ambas às espécies de plantas isca. Nas áreas cultivadas, constatou-se uma intensa redução da população de rizóbios no solo, em especial logo após a colheita da soja, continuando o decréscimo até o último período de avaliação. Conclui-se que o cultivo da soja inoculada com rizóbio eleva a densidade de rizóbios em solo do cerrado, mas durante a estiagem ocorre uma drástica redução dessa população, que pode chegar a mais de 99% considerando o início e final do período. ABSTRACT: The biological nitrogen fixation in legumes is performed by a group of bacteria known as rhizobia. The survival of these bacteria in soils is affected by several factors, such as temperature, drought and soil fertility. This study was performed to evaluate the dynamics of rhizobia in the soil after soybean cultivation and during a dry season in the cerrado of Roraima. Three areas were sampled: i) native cerrado as reference; ii) an area previously cultivated with soybean for one season; and iii) another one cultivated for two seasons also with soybean. The soil was sampled at a depth of 0-10 cm in five times (0, 45, 90, 135 and 180 days) during the dry season (September 2006 to March 2007). The rhizobial density in the soil was evaluated by the most probable number method with infection of soybean and cowpea plants. It was observed very low number of soybean nodulating bacteria in the reference area, but a high density, of up to several hundred rhizobia capable to nodulate cowpea was measured in this same area. Cropping of soybean with inoculated seeds increased rhizobial density evaluated by both trapping hosts. In cropped areas, an intense reduction of rhizobium density was observed just after soybean harvest, and this reduction continued until the end of the period of evaluation. It was concluded that soybean cultivation increases the density of rhizobial in the cerrado soil; however, this density is drastically reduced, during the dry season, by 99% at the end of the dry period

Multi‑objective forest harvesting under sustainable and economic principles.

Selective logging is well-recognized as an efective practice in sustainable forest management. However, the ecological efciency or resilience of the residual stand is often in doubt. Recovery time depends on operational variables, diversity, and forest structure. Selective logging is excellent but is open to changes. This may be resolved by mathematical programming and this study integrates the economic-ecological aspects in multi-objective function by applying two evolutionary algorithms. The function maximizes remaining stand diversity, merchantable logs, and the inverse of distance between trees for harvesting and log landings points. The Brazilian rainforest database (566 trees) was used to simulate our 216-ha model. The log landing design has a maximum volume limit of 500 m3 . The nondominated sorting genetic algorithm was applied to solve the main optimization problem. In parallel, a sub-problem (p-facility allocation) was solved for landing allocation by a genetic algorithm. Pareto frontier analysis was applied to distinguish the gradients α-economic, β-ecological, and γ-equilibrium. As expected, the solutions have high diameter changes in the residual stand (average removal of approximately 16 m3 ha−1). All solutions showed a grouping of trees selected for harvesting, although there was no formation of large clearings (percentage of canopy removal<7%, with an average of 2.5 ind ha−1). There were no diferences in foristic composition by preferentially selecting species with greater frequency in the initial stand for harvesting. This implies a lower impact on the demographic rates of the remaining stand. The methodology should support projects of reduced impact logging by using spatial-diversity information to guide better practices in tropical forests

Realistic Equations of State for the Primeval Universe

Early universe equations of state including realistic interactions between constituents are built up. Under certain reasonable assumptions, these equations are able to generate an inflationary regime prior to the nucleosynthesis period. The resulting accelerated expansion is intense enough to solve the flatness and horizon problems. In the cases of curvature parameter \kappa equal to 0 or +1, the model is able to avoid the initial singularity and offers a natural explanation for why the universe is in expansion.Comment: 32 pages, 5 figures. Citations added in this version. Accepted EPJ

Casimir interaction between a microscopic dipole oscillator and a macroscopic solenoid

We discuss the interaction between a microscopic electric dipole oscillator and a long solenoid which are separated by a small distance. The solenoid belongs to a simple RLC circuit and the zero point and thermal current fluctuations within the solenoid coils are taken into account. We describe how they affect the equilibrium state and the excited states of the oscillator, thus providing a description of the Casimir interaction of the system. We calculate the modification in the lifetime of the oscillator excited states as a function of the parameters of the circuit, the dipole orientation, and the distance between the dipole and the solenoid. The Casimir force between the solenoid and the electric dipole is calculated, and it is shown that this Casimir interaction always exists, that is, it occurs even when the macroscopic current in the solenoid is zero. We suggest experiments which can exhibit these effects related to the electromagnetic interactions between atoms or molecules and simple circuits

Programa bancos comunitários de sementes de adubos verdes em Minas Gerais.

Benefícios da adubação verde. Adubação verde e energia. O estado da arte da adubação verde em Minas Gerais. O banco comunitário. Programa Bancos Comunitários de Sementes de Adubos Verdes (PBCSAV). Da semeadura e colheita das leguminosas à semeadura do milho.bitstream/CNPAF-2009-09/28189/1/Com_165.pd