Determinação da cor do solo a partir de dados radiométricos e sua relação com teores de hematita.

Color is widely recognized as a primary identifying parameter of soil. The physical, mineralogical, and chemical properties can be derived from assessing the subsurface color characteristics. The present research aimed to estimating the hematite content clay fraction, in laboratory, from data related to soil color obtained by using automatic devices. Fifteen subsurface soil samples from São Paulo State had their clay fraction hematite contents semiquantitavely determined by the association of chemical and physical methods and their colors evaluated in laboratory through measurements made with a spectro-radiometer. The radiometric data were used to the determination of soil color in L*a*b* and Munsell systems and to the calculation of reddish indexes (RI). The RI values show functional dependence of hematite contents and the best relation is verified with RI values derived from color determined in the L*a*b* system. Exponential models, developed from remote sensors, show themselves adequate in predicting the soil hematite contents

Melatonin effect on cryopreserved sperm cells of crioulo stallions.

Abstract: The freezing/thawing process of spermatozoa can cause cellular damage to the male gamete, decreasing the fertilization potential due to the increase in the production of reactive oxygen species (ROS). Melatonin is a potent endogenous antioxidant that protects the body against the damage caused by ROS. This study has evaluated different melatonin concentrations on the sperm viability of cryopreserved semen of Crioulo stallions. For that, three ejaculates were collected from five stallions diluted in a commercial extender followed by centrifugation and resuspension in a commercial freezing extender supplemented with 0; 1.25; 2.5. 5mM of Melatonin before the cryopreservation process. After thawing, the evaluation was performed assessing motility and flow cytometry evaluations: the plasma membrane integrity (PI), the integrity of the acrosomal membrane (FITC-PNA), mitochondrial membrane potential (JC1), and ROS generation (DCF-DA). Our results showed that sperm motility in the group without Melatonin and the 1.25mM group did not show the difference; however, the groups 2.5mM and 5mM presented a reduction in sperm motility. The 1.25 mM concentration was able to protect the plasma membrane during the cryopreservation process, in addition to showing a significant reduction in the production of ROS and increasing the percentage of sperm with integral acrosome. It can also be seen that high concentrations of Melatonin did not show beneficial effects. In conclusion, the addition of 1.25 mM of the Melatonin in Crioulo sperm cells showed to have a protective effect on the sperm cell during cryopreservation

Physical structure of Green River oil shale from Colorado /

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