Developmental potential of vitrified holstein cattle embryos fertilized in vitro with sex-sorted sperm

In vitro fertilization (IVF) is a feasible way to utilize sex-sorted sperm to produce offspring of a predetermined sex in the livestock industry. The objective of the present study was to examine the effects of various factors on bovine IVF and to systema

Observations on the spawning behavior of artificially matured Japanese eels Anguilla japonica in captivity

Spawning behavior of artificially matured Japanese eels Anguillo japonica in captivity was investigated using a DVD Video image system. Following a routine hormone treatment technique for this fish, female eels were artificially matured by weekly intramuscular injections of salmon pituitary extracts (SPE) at a dosage of 40 mg kg(-1) BW for a total of 7-11 doses to induce ovarian maturation, while male eels received weekly intramuscular injections of human chorionic gonadotropin (HCG) at a dosage of 1000 IU kg(-1) BW for a total of 6-11 doses at 18 degrees C to induce testicular maturation in a separate aquarium. In this experiment, three pairs of such hormone-treated matured eels were acclimatized in seawater in 1.5 m(3) experimental aquaria with or without shelters at 20 degrees C for 24 h. Twenty four hours after the acclimatization terminated, the females received SPE injections to boost maturation and ovulation. Twenty four hours following these injections, the females received injections of HCG (1000 IU per fish, HCG injection) and 17 alpha-hydroxyprogesterone (2 mg per fish) to induce ovulation, while males were given HCG injections (1000 IU per fish, HCG injection) to induce spermiation. Video taping started after the 24 h acclimatization terminated and last for a total of 96 h. Before the HCG injections, both sexes were inactive, staying on the bottom or in shelters if available. Following these HCG injections, they became active and frequently left the bottom swimming in the water column. During the 24 h following HCG injections, activity accounted for 67% and 45% of the total activity in no shelter treatment for females and males, respectively, in comparison with 77% and 78% in shelter treatment. Activity was significantly more pronounced during this phase than during other phases for each sex in either shelter treatment. Egg release and sperm ejection occurred in the water column around the time eels' activity reached peaks. Eels either returned into the shelters or stayed motionlessly on the bottom of the aquaria after egg release and sperm ejection. Eight out of nine (89%) females in no shelter treatment spontaneously released eggs with a total of 11 batches 14-18 h following HCG injections, in contrast with four out of nine (44%) females releasing eggs for 4 batches 16-20 h in shelter treatment. Males arrived at activity peaks 11-13 h following HCG injections in no shelter treatment, 2-4 h ahead of the females (14-16 h), in comparison with 8-11 h in shelter treatment with 5-6 h ahead of the females (14-17 h). Courtship behavior indicative of spawning such as pairing, chasing and touching bodies was not observed in the eels in this study. However, on many occasions, eels of both sexes (male-female or female-female) were found to "cruise together" in water column for a short time period or frequently come together prior to releasing eggs and ejecting sperm, suggesting the possibility of group mating in artificially matured Japanese eels. (c) 2007 Elsevier B.V. All rights reserved.

An improved microtiter assay for evaluating anti-HIV-I neutralizing antibodies from sera or plasma

Background: The anti-HIV-1 neutralizing antibody assay is widely used in AIDS vaccine research and other experimental and clinical studies. The vital dye staining method applied in the detection of anti-HIV-1 neutralizing antibody has been used in many laboratories. However, the unknown factor(s) in sera or plasma affected cell growth and caused protection when the tested sera or plasma was continuously maintained in cell culture. In addition, the poor solubility of neutral red in medium (such as RPMI-1640) also limited the use of this assay. Methods: In this study, human T cell line C8166 was used as host cells, and 3-(4,5-Dimethyl-2-thiazolyl)- 2,5-diphenyl-2H-tetrazolium bromide (MTT) instead of neutral red was used as vital dye. In order to avoid the effect of the unknown factor( s), the tested sera or plasma was removed by a washout procedure after initial 3 - 6 h culture in the assay. Result: This new assay eliminated the effect of the tested sera or plasma on cell growth, improved the reliability of detection of anti-HIV-1 neutralizing antibody, and showed excellent agreement with the p24 antigen method. Conclusion: The results suggest that the improved assay is relatively simple, highly duplicable, cost-effective, and well reliable for evaluating anti-HIV-1 neutralizing antibodies from sera or plasma.

RESPONSES OF Elodea nuttallii AND Ceratophyllum demersum TO HIGH TEMPERATURE

There were large losses of exotic species Elodea nuttallii during summer in eutrophic lakes of the middle and lower reaches of the Yanatze River, China. To investigate the main causes, the heat tolerance of E. nuttallii was studied and compared with that of native species Ceratopkyllum demersum by using an aquaria system in the laboratory. Under 4500 lx light intensity and 12-h L/12-h D cycle, E. nuttallii cultured in 1/5 Hoaglands solution at 39 degrees C showed a positive growth rate during the first 15 days, and the growth rate was higher than that at 35 degrees C. But after 15 days, the growth rates became negative for those cultured both at 39 and 35 degrees C. However, the growth rate was positive for more than 20 days for those cultured at 25 degrees C. Under the same conditions, the growth rate, productivity and chlorophyll content of E. nuttallii were significantly higher than that of C. demersum. Heat tolerance of E. nuttallii was also stronger than that of C. demersum. The optimal temperature for the growth of the two plants depended on the experimental period: both plants grew at an optimal rate at higher temperature if the experimental period was short; nevertheless the plants achieved optimal growth at a lower temperature if the experiment was conducted for a longer period. At the same light intensity, the heat tolerance of C. demersum in tap water with sediment was markedly stronger than that of E. nuttallii at 39 degrees C. Average growth rate of C. demersum was 4.5 times higher than that of E. nuttallii within 25 days. The positive growth period lasted for less than 25 days for E. nuttallii and for more than 25 days for C. demersum. When they were cultured in 1/5 Hoaglands solution and in tap water with sediment, the growth rate of C. demersum increased from 0.4 to 79.4 mg/d.g fresh weight (FW) within 20 days. E. nuttallii increased from 8.3 to 24.4 mg/d-g FW within 20 days. Both grew better in tap water with sediment than in 1/5 Hoaglands solution. The results demonstrated that the nutritional status of the water other than the high temperature affected the heat tolerance of E. nuttallii during summer. E. nuttallii has great ecological safe risk in China.

Three different viruses observed from the tissues of diseased mandarin fish Siniperca chuatsi

Three different kinds of viruses, the spherical virus SCSV with a diameter of about 280 nm, the rhabdovirus SCRV with a size about 250 x 120 nm, and the baculovirus SCBV with a size about 200 x 100 nm, were observed from the tissues of diseased mandarin fish Siniperca chuatsi with outbreak of infection and acute lethality. This phenomenon implicated that the reason why the epizootic disease of mandarin fish could not be quenched by only one kind of virus vaccine can be explained by the fact that the fish may be infected by different kinds of viruses. Therefore, more attention should be paid to the complexity of virus pathogens in the prevention strategy for mandarin fish diseases.

煤系地层三维三分量地震数据解释方法研究

Conventional 3D seismic exploration cannot meet the demand of high yield and high efficiency safe production in coal mine any more. Now it is urgent to improve the discovery degree of coal mine geological structures for coal production in China. Based on 3D3C seismic exploration data, multi-component seismic information is fully excavated. First systematic research on 3D3C seismic data interpretation of coal measure strata is carried out. Firstly, by analyzing the coal measure strata, the seismic-geologic model of coal measure strata is built. Shear wave logging is built by using regression analysis. Horizon calibration methods of PP-wave and PS-wave are studied and the multi-wave data are used together to interpret small faults. Using main amplitude analysis technology, small faults which cannot be found from PP-wave sections can be interpreted from the low frequency PS-wave sections. Thus, the purpose to applying PS-wave data to fine structure assistant interpretation is achieved. Secondly, PP- and PS-wave post-stack well constrained inversion methods of coal measure strata are studied. Joint PP- and PS-wave post-stack inversion flow is established. More attribute parameters, which are applied in fine lithology interpretation of coal measure strata, are obtained from combinations of the inversion results. Exploring the relation between rock with negative Poisson’s ratio and anisotropy, fracture development in coal seam are predicted. Petrophysical features of coal measure strata are studied, and the relations between elastic parameters and lithology, fluid and physical properties are established. Inversions of the physical parameters such as porosity, permeability and water saturation, which reflect lithology and fluid property, are obtained. Finally, the approaches of shear wave splitting and Thomsen parameters inversion, which provide new ideas for seismic anisotropy interpretation of coal measure strata, are studied to predict fracture development. The results of practical application indicate that the methods in this paper have good feasibility and applicability. They have positive significance for high yield and high efficiency safe production in coal mine.

水库滑坡复活机理及其发展趋势预测研究

Various numbers of ancient landslides of various scales are frequently distributed on both banks of reservoirs, especially large reservoirs, both in China and abroad. During inundation and operation of theses reservoirs, some of the landslides are reactivated, which caused losses of people's lives and properties to various extents, some even disasters. Systematic studies are, however, very few on the reservoir-induced reactivation mechanism and development tendency prediction. Based on investigation of reservoir-induced reactivation phenomena of ancient landslides and relevant existing research problems, a systematic study is carried out on the field identification, induced reactivation mechanism, development tendency prediction, risk decision-making and treatment of reservoir-related ancient landslides, through analysis of large numbers of engineering geological investigation results, scientific experimental and research results, in combination with prevention and treatment practices of reservoir-related landslides both in China and abroad, and a series of research results have been obtained. 1. On the basis of study of the distribution features, genesis mechanism of ancient landslides on river banks, a set of scientific methods are summarized on field identification of ancient landslides, and a significant method named "lithologic sequence method" or "indicator layer method", is proposed, which is proved to be very useful. 2. A detail study is made on the reservoir-induced hydraulic effects and material mechanic effects (or softening effects) on the ancient landslide through model and case studies, which concludes that the magnitude and properties of reservoir-induced hydraulic effects are related to the shapes of sliding planes, water content and permeability of landslide materials and variation rate and magnitude of reservoir levels; the magnitude of material mechanic effects are related to the material composition (including mineral composition and grain size), natural water content and saturation state of sliding zones. Also a sensitive analysis is made on the factors that are related to the stabilities of the landslides, which indicate that the stability of a landslide is more sensitive to the groundwater head h_w in the slides and the inner friction angleψof sliding zones than others. 3. The joint inducing mechanism of rainfall and reservoir is also discussed in the paper through model analysis and case study, which proves that reservoir inundation increases firstly the sensitivity of a landslides to rainfall through reduction of its stability or cracking deformation which will increase the rainfall infiltration to the slide body, and then rainfall triggers reactivation or intensifies the reservoir-induced deformation of a landslide. 4. Based on rheologic test results of sliding zones of several reservoir-related ancient landslides, the rheologic characteristics of sliding zones have been discussed in detail and several typical rheologic models have been set up, which well explains the dynamic process of slide deformation. The response types to reservoir inundation and development tendency of reservoir -related ancient landslide are discussed in the paper based on field investigation results. And prediction methods for reservoir-related landslides have been studied based on the Mate-Synthetic principle of quantitative and qualitative analysis, as well as combination of computation and internal mechanism analysis, and a rheologic analytical method is proposed which is proved very useful for prediction of the landslide development tendency. 6. In disaster-prevention and treatment of reservoir-related landslides, risk decision-making has been proved very significant both in engineering and economics. Based on the practices in disaster-prevention and treatment of reservoir-related landslides both in China and abroad, the disaster-prevention risk decision-making for reservoir-related landslides has been proposed in terms of philosophy, methods and procedures, and well put into practice. A summary is also made through case study of the experiences of treatment of reservoir-related landslides both in China and abroad in terms of principle, methods and technical lines. 7 A detail study is made as a case study of the reactivated Maoping ancient landslide on the left bank of the Geheyan Reservoir on Qingjiang river in Hubei province, China, including its field identification features, reservoir-induced reactivation characteristics and mechanism, development tendency prediction and proposed counter measures based on risk analysis.