Effects of various cryoprotectants on the survival of mouse embryos cryopreserved by the quick freezing method

The effects of concentrations of glycerol, ethylene glycol or dimethylsulphoxide (DMSO) in the presence of either 0.25 M lactose or sucrose on the post-thaw survival of mouse quickly-frozen compacted morulae were studied. In this method, the embryos were directly frozen in liquid nitrogen (LN2) vapor at approximately -170 degrees C for 2 min before being plunged into LN2. High survival rates of frozen-thawed embryos were obtained when the freezing medium contained 3 M ethylene glycol with either 0.25 M lactose or sucrose (76.5 and 70.2%, respectively). When the embryos were frozen in glycerol, significantly high survival was obtained with 3 M glycerol + 0.25 M sucrose (73.5%, P less than 0.001). However, a freezing medium containing DMSO with either sugar gave lower survival rates. At a higher concentration of 4 M, ethylene glycol with 0.25 M lactose gave significantly higher survival rate than glycerol or DMSO (P less than 0.05). Significantly higher rates were obtained at 2 M with all 3 cryoprotectants when the freezing medium contained lactose rather than sucrose (P less than 0.05). This study showed that glycerol and ethylene glycol were effective cryoprotectants in the quick freezing of mouse embryos, while DMSO was less effective. In addition, the protective effects of these cryoprotectants are affected by their concentrations and the type of sugar used.     

Peritoneal lavage in the horse.

Eight horses ranging in age from 4 days to 9 years were treated for peritonitis. Escherichia coli was isolated in four cases and Nocardia sp in one case. In each case, a catheter placed in the peritoneal cavity allowed drainage of a large amount of purulent fluid. Retrograde peritoneal lavage was performed through a Foley catheter or medical tubing, using Ringer's lactate solution containing kanamycin, povidone iodine, or nitrofurazone. All except two horses responded well to repeated lavage.     

Navicular disease in the hindlimbs of the horse

Of 124 horses determined to have navicular disease during a 5-year period, 6 had clinical and radiographic signs of the disease in both hindlimbs. These 6 were all castrated males, ranging in age from 3 to 12 years, and were used for work of similar nature: roping, cutting, and pleasure. Treatment consisted of posterior digital neurectomy and corrective shoeing in 2 cases, posterior digital neurectomy alone in 2 cases, and corrective shoeing alone in 2 cases. Following treatment, lameness subsided, and all 6 horses were returned to full use.     

Deforestation and Cultivation with Maize (Zea mays L.) has a Profound Effect on the Bacterial Community Structure in Soil

In this study, the effect of deforestation and cultivation of maize (Zea mays L.) on the physicochemical characteristics and the bacterial community structure in soil were studied at the national park Área de Protección de Flora y Fauna Nevado de Toluca in Mexico. Soil was sampled from three forested areas in the national park, from three deforested areas grazed by animals and from three areas cultivated with maize. The soil was characterized chemically and biologically, whilst the bacterial community structure was investigated through 454 pyrosequencing of the 16S rRNA gene. The pH in the forest soil decreased from 6·1 to 5·3 in the maize‐cultivated soil, whilst the soil organic C content decreased 1·4 times in the arable soil compared with the forest soil. The microbial biomass C decreased 2·9 times in the arable soil compared with the forest soil, but the metabolic quotient qCO₂ (ratio basal respiration to microbial biomass C) nearly doubled. Deforestation and maize cultivation reduced the abundance of Proteobacteria, Actinobacteria and Bacteroidetes, whereas Acidobacteria, Chloroflexi, Gemmatimonadetes and Firmicutes were resistant to these changes. It was found that soil characteristics were affected negatively by deforestation and nearly half of the organic matter was lost, and on these sloped fields, erosion will be high, further decreasing soil fertility. Although the relative abundance of a number of bacterial groups was reduced by deforestation, others were not affected by land‐use change. Copyright © 2014 John Wiley & Sons, Ltd.     

Exogenous expression of rat aquaporin-3 enhances permeability to water and cryoprotectants of immature oocytes in the zebrafish (Danio rerio)

Movement of water and cryoprotectants through the plasma membrane needs to be accelerated for successful cryopreservation of zebrafish oocytes/embryos, which are much larger than their mammalian counterparts. Aquaporin-3 is a water/solute channel that can transport not only water but also various cryoprotectants. In this study, we attempted to increase the permeability of immature zebrafish oocytes at stage III to water and cryoprotectants by exogenous expression of rat aquaporin-3. Immature zebrafish oocytes were injected with rat aquaporin-3 cRNA and cultured for 5-12 h. Permeability to water and cryoprotectants was then determined based on changes in the volumes of the oocytes in a hypertonic sucrose solution and various cryoprotectant solutions at 25 C. The permeability to water of the aquaporin-3 cRNA-injected oocytes was three times higher than that of intact and water-injected oocytes. The permeability of the aquaporin-3 cRNA-injected oocytes to ethylene glycol, glycerol, propylene glycol, and DMSO was also 2-4 times higher than that of intact oocytes. Thus, the permeability of immature zebrafish oocytes to water and cryoprotectants was enhanced by exogenous expression of aquaporin-3. Cryopreservation of teleost oocytes may be realized through a further increase in permeability.     

Experimental test of oyster restoration within eelgrass

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Biofilm consumption shapes the intestinal microbiota of shrimp (Penaeus vannamei)

The effect using biofilm as complementary feed for shrimp (Penaeus vannamei) on the taxonomic and functional profile of its intestinal microbiota was evaluated. Shrimp were cultured for 30 days in two similar low‐water exchange systems, one using commercial feed and the other a combination of commercial feed with biofilm as complementary feed source. Six bacteria phyla were detected in the intestine of shrimp from both treatments (Actinobacteria, Bacteroidetes, Cyanobacteria, Firmicutes, Fusobacteria and Proteobacteria), being Proteobacteria the most abundant (81%–92%). However, this later phylum was significantly less dominant in shrimp fed with biofilm; this drop was associated with a decrease in Vibrio abundance. Differences in the taxonomic profile of bacteria between treatments were also observed through principal component analysis where the diet was the main influencing factor (PC1 72.4%). Regarding functional inference, similarities were detected between treatments. Carbohydrate and energy metabolism were the most abundant functions regardless of time or diet, followed by metabolism of cofactors and vitamins, translation processes, nucleotide metabolism and others. Results suggest that biofilm consumption influenced the taxonomic profile bacteria colonizing the shrimp intestine; however, a functional redundancy was observed despite the use of biofilm as complementary feed. Finally, shrimp fed with biofilm showed a better productive response.     

俄罗斯远东地区植物病毒名录

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Simultaneous Measurement of Local Gain and Electron Density in X-ray Lasers

X-ray lasers (XRLs) have experimental average gains that are significantly less than calculated values and a persistently low level of spatial coherence. An XRL has been used both as an injected signal to a short XRL amplifier and as an interferometer beam to measure two-dimensional local gain and density profiles of the XRL plasma with a resolution near 1 micrometer. The measured local gain is in agreement with atomic models but is unexpectedly spatially inhomogeneous. This inhomogeneity is responsible for the low level of spatial coherence observed and helps explain the disparity between observed and simulated gains.