Effects of repeated electroejaculations on kinematic sperm subpopulations and quality markers of Mexican creole goats.

Here we show the effects of repeated electroejaculation (EE) on mean values of motility, mitochondrial functionality, and expression of active caspases on goat sperm obtained by EE. Evaluations were done using CASA and flow cytometry. A strategy for identification of kinematic sperm subpopulations, when individual data of sperm are not provided by the CASA system, is provided. Fifty semen samples, five of each of ten adult creole goats, were obtained by electroejaculation. Mean values of total motility, progressive motility and flow cytometry evaluations were compared among EEs. Relationships among mean values of variables were investigated using Spearman correlation and principal component analysis (PCA). For identification of kinematic sperm subpopulations, PCA followed by hierarchical clustering was applied on data of the intervals provided automatically by the CASA system. Total motility does no change after repeated EE. Mean values of motility parameters and molecular markers were unrelated in multivariate space, but bivariate correlations were found. Values in upper and lower intervals defined clearly the sperm subpopulations, which had motility parameters changing over time. Taken together, our results show that repeated EE does not affect mean values of total motility, that molecular markers are not related with motility parameters, and that it is possible to identify kinematic sperm subpopulations when individual data, of motility parameters, are not provided by the CASA system.

As(III) and As(V) sorption on iron-modified non-pyrolyzed and pyrolyzed biomass from Petroselinum crispum (parsley).

The sorption of As(III) and As(V) from aqueous solutions onto iron-modified Petroselinum crispum (PCFe) and iron-modified carbonaceous material from the pyrolysis of P. crispum (PCTTFe) was investigated. The modified sorbents were characterized with scanning electron microscopy. The sorbent elemental composition was determined with energy-dispersive X-ray spectroscopy (EDS). The principal functional groups from the sorbents were determined with FT-IR. The specific surfaces and points of zero charge (pzc) of the materials were also determined. As(III) and As(V) sorption onto the modified sorbents were performed in a batch system. After the sorption process, the As content in the liquid and solid phases was determined with atomic absorption and neutron activation analyses, respectively. After the arsenic sorption processes, the desorption of Fe from PCFe and PCTTFe was verified with atomic absorption spectrometry. The morphology of PC changed after iron modification. The specific area and pzc differed significantly between the iron-modified non-pyrolyzed and pyrolyzed P. crispum. The kinetics of the arsenite and arsenate sorption processes were described with a pseudo-second-order model. The Langmuir-Freundlich model provided the isotherms with the best fit. Less than 0.02% of the Fe was desorbed from the PCFe and PCTTFe after the As(III) and As(V) sorption processes.

Adsorption kinetic of arsenates as water pollutant on iron, manganese and iron-manganese-modified clinoptilolite-rich tuffs.

Arsenate adsorption from aqueous solutions onto clinoptilolite-heulandite rich tuffs modified with iron or manganese or a mixture of both iron and manganese in this work was investigated. A kinetic model was considered to describe the arsenates adsorption on each zeolitic material. The modified clinoptilolite-heulandite rich tuffs were characterized by scanning electron microscopy and X-ray diffraction analysis. The elemental composition and the specific surface area of the zeolitic material were also determined. The arsenate adsorption by the modified zeolites was carried on in a batch system considering a contact time from 5 min to 24h for the kinetic experimentation. The arsenic was detected by atomic absorption spectrometer using a hydride generator. The kinetics of the arsenate adsorption processes were described by the pseudo-second-order model and the obtained parameter k varies from 0.15 to 5.66 microg/gh. In general, the results suggested that the kinetic adsorption of arsenates on the modified clinoptilolite-rich tuffs depend of the metallic specie that modified the surface characteristics of the zeolitic material, the chemical nature of the metal as well as the association between different metallic chemical species in the zeolitic surface.