Manipulated Mouse Embryos as Bioassay System for Water Quality Control

Mouse pronuclear stage embryos with intact slit zona pellucida (manipulated) were cultured in vitro until the hatched blastocyst stage in simplex optimized medium with higher K⁺ concentration (KSOM) prepared with three different water types: tap, deionized reverse osmosis (D‐O) water and Milli‐Q system (M‐Q) water. The culture media were supplemented with or without protein and ethylenediaminetetraacetic acid (EDTA, disodium salt). The rates of hatched blastocysts were significantly affected (p < 0.01) by micromanipulation, protein supplement and water source. The water source has no influence (p > 0.05) on development in EDTA‐supplemented protein‐free culture media, whereas in EDTA‐ and protein‐free culture media, the water quality significantly (p < 0.001) affected the rates of development, with higher rates in media prepared with M‐Q water. The micromanipulated embryos showed higher sensitivity to the water quality (p < 0.01). It worth mentioning that the rates of hatched blastocysts in protein‐free culture media were very low (0–7.5%). Furthermore, the three different water types were analysed by measuring the electrical conductivity, inorganic ions, total organic carbon and endotoxins to evaluate the purity. M‐Q water showed the lowest levels of inorganic ion, total organic carbon and endotoxin concentrations. We concluded that manipulated mouse embryos are good system to evaluate the quality of water used in biological system.     

ACE inhibition in goats under fixed‐time artificial insemination protocol increases the pregnancy rate and twin births

To assess the effect of the angiotensin‐converting enzyme (ACE) inhibition on the efficiency of the fixed‐time artificial insemination (TAI), 69 goats were divided randomly into two groups: enalapril (n = 35) and control (n = 34). In the experiment, all animals underwent the protocol of fixed‐time artificial insemination for 12 days. Enalapril group received enalapril maleate dissolved in saline (Enalapril, Lab Teuto Ltda) subcutaneously at the following doses: 0.2 mg/kg/day in D0‐D2; 0.3 mg/kg/day in D3‐D6 and 0.4 mg/kg/day in D7‐D11. The control group received the corresponding volume of 0.9% saline solution. We performed a single insemination 36 hr after sponge removal using frozen semen from two adult male goats with recognized fertility. The ultrasound pregnancy diagnosis was 30 days after the artificial insemination (AI). There was significant increase in pregnancy rates and twinning as well as a decrease in foetal loss in animals receiving enalapril (p < .01). The use of ACE inhibitors during the TAI protocol was shown to be a promising alternative to increase the efficiency of such reproductive biotechnology.     

Gonadotropin‐induced Puberty Does Not Impair Reproductive Performance of Gilts over Three Parities

The aim of this study was to evaluate the reproductive performance of three parities of gilts treated or not treated with gonadotropin to induce puberty. Sixty gilts received 600 IU of equine chorionic gonadotropin (eCG) followed by 2.5 mg of porcine luteinizing hormone (LH) 72 h later. Fifty‐nine other gilts were exposed only to a mature boar for 15 min twice daily. Artificial insemination (AI) was performed at 0, 12 and 24 h after the detection of oestrus, and gestation was confirmed by ultrasound after 35 days. Sows were inseminated at the first post‐weaning oestrus. The total numbers of piglets born, piglets born alive, stillborn, mummified foetuses, as well as pregnancy and farrowing rates were evaluated for each of the three parities. Culling rates, farrowing intervals and weaning‐to‐oestrous intervals (WEI) were also analysed. Mean age at puberty and oestrous manifestation were not significantly different between treatments (p = 0.0639; 179.20 ± 17.52 compared with 173.96 ± 16.94, 91.66% compared with 94.92%) across the experimental period. However, females that underwent puberty induction showed modest increases both in the number of total pigs born and in the number of piglets born alive. In conclusion, puberty induction through exogenous gonadotropin administration in field conditions did not induce a more concentrated first oestrous manifestation, but trended to a modest increase in the number of pigs born alive in the first parity and a reduced culling rate during the first gestation.     

Chemical Composition of the Lunar Surface in a Terra Region near the Crater Tycho

More precise and comprehensive analytical results for lunar surface material in a terra region have been derived from the data of the alpha-scattering experiment on Surveyor 7. The silicon content and the low sodium abundance are close to that of mare material. The abundances of titanium and iron are at least a factor of 2 lower, whereas the abundances of aluminum and calcium are significantly higher. The analytical results provide direct evidence for chemical differentiation in the moon and indicate a lunar crust of appreciably lower density than the whole moon and with lower density and higher albedo than lunar mare material.     

Chemical composition of the lunar surface in sinus medii

More precise and comprehensive analytical results for lunar material in Sinus Medii have been derived from the alpha-scattering experiment on Surveyor VI. The amounts of the principal constituents at this mare are approximately the same as those of constituents at Mare Tranquillitatis. The sodium contents of both maria are lower than those of terrestrial basalts. The titanium content at Sinus Medii is lower than that at Mare Tranquillitatis; this suggests important differences in detailed chemical composition at different mare areas on the moon.     

Effect of Different Levels of Wheat Straw Soil Surface Coverage on Weed Flora in Vicia faba Crops

The crop system implemented on organic farms requires that crop residues are incorporated into the soil following the end of wheat cultivation. This system leads to a reduction in soil moisture and the creation of favourable conditions for the emergence of weeds. In contrast, covering the soil with 60 % crop residues was found to maintain soil moisture and lead to a reduction in dry weed mass, population density and population frequency as well as a reduction in population diversity, regardless of the initial weed flora before the implementation of different soil tillage systems. Finally, an increase in the prevalence of broad‐leafed weeds was observed as the level of soil cover increased.     

Dissipation of three organochlorine and four pyrethroid pesticides sprayed in a greenhouse environment during hydroponic cultivation of gerbera

A wide range of pesticides (insecticides, acaricides and fungicides) is used in the hydroponic cultivation of gerbera. The fate and behaviour of some of these commonly used pesticides (organochlorine and pyrethroid insecticides/acaricides) in a greenhouse installation was investigated. The concentrations of endosulfan, dicofol, tetradifon, permethrin, bifenthrin, cypermethrin and deltamethrin in the air of the greenhouse were related to their physicochemical properties and respective application rates. Of these compounds, endosulfan exhibited the highest concentration in the greenhouse air 2 h after application (10 microg m(-3)), due to its highest volatility; afterwards, up to 12 h post-application, a rapid decrease was recorded which finally led to a concentration of 0.41 microg m(-3) at 6 days post-application. Dicofol exhibited the same trend of dissipation in the greenhouse air; its concentration decreased from 0.27 microg m(-3) immediately after the application to 0.12 microg m(-3) at 6 days post-application. Tetradifon, bifenthrin and permethrin were found at concentrations lower than 0.1 microg m(-3) at 2 h post-application, and cypermethrin and deltamethrin could not be detected. The concentrations of all the above pesticides in the drain water of the open hydroponic system were relatively high immediately after application and decreased rapidly during the following 3 days. In the closed hydroponic system, all the pesticides accumulated in the nutrient solution during the first 24 h after application and slowly decreased in concentration over the following 3 days. The spray operators applying these pesticides were exposed to rather high concentrations and the spray deposits were monitored on the chest and forehead of the operator. Endosulfan exhibited the highest concentrations of the seven pesticides. The organochlorine pesticides (endosulfan, dicofol and tetradifon) were usually detected at higher concentrations on the chest than on the forehead of the operator; pyrethroids were detected at higher concentrations on the forehead than on the chest of the operator.     

Cassini dust measurements at Enceladus and implications for the origin of the E ring

During Cassini's close flyby of Enceladus on 14 July 2005, the High Rate Detector of the Cosmic Dust Analyzer registered micron-sized dust particles enveloping this satellite. The dust impact rate peaked about 1 minute before the closest approach of the spacecraft to the moon. This asymmetric signature is consistent with a locally enhanced dust production in the south polar region of Enceladus. Other Cassini experiments revealed evidence for geophysical activities near Enceladus' south pole: a high surface temperature and a release of water gas. Production or release of dust particles related to these processes may provide the dominant source of Saturn's E ring.     

Impact features on Stardust: implications for comet 81P/Wild 2 dust

Particles emanating from comet 81P/Wild 2 collided with the Stardust spacecraft at 6.1 kilometers per second, producing hypervelocity impact features on the collector surfaces that were returned to Earth. The morphologies of these surprisingly diverse features were created by particles varying from dense mineral grains to loosely bound, polymineralic aggregates ranging from tens of nanometers to hundreds of micrometers in size. The cumulative size distribution of Wild 2 dust is shallower than that of comet Halley, yet steeper than that of comet Grigg-Skjellerup.