STUDY ON MIXIS POTENTIAL OF ROTIFER RESTING EGGS ( BRACHIONUS PLICATILIS ) WITH DIFFERENT COLLECTION TIMES AND DIFFERENT PRESERVATION PERIODS

The present study investigated the possible changes in the mixis potential of rotifer resting eggs produced by a single stock of Brachionus plicatilis and collected and preserved annually from 1985-1998. Several clones derived from each batch of resting eggs were cultured under the same conditions for 21 days. The percentage of clones appearing resting eggs and the average yield of resting eggs produced from each clone were recorded and statistically analyzed to find the differences between the mixis potential of those resting egg batches. Results showed that different batches of resting eggs had different mictic levels among their descendent clones; but no regular relationship was found between the mixis potential of resting eggs and their collection times/preservation periods. Several internal and external factors that might affect the mixis potential of resting eggs were discussed.

Design and Research of Information Processing System Based on Mix Platform

Aim To develop an information processing system with real time processing capability and artistic user interface for the optoelectronic antagonism general measuring system. Methods The A/D board and the multifunctional board communicating with every instruments were designed, data collecting and processing were realized by selecting appropriate software platform. Results Simulating results show the information processing system can operate correctly and dependably, the measuring rules, interactive interface and data handling method were all accepted by the user. Conclusion The designing approach based on the mix platform takes advantages of the two operating systems, the desired performances are acquired both in the real time processing and with the friendly artistic user interface.

Determination of Organic Acids in Root Exudates byHigh Performance Liquid Chromatography: III. Effectsof Interfering Factors

A solution culture experiment was conducted to investigate the effects of collection time and interferingions on separation and determination of low-molecular-weight organic acids in root exudates of soybeanusing the method for directly collecting root exudates. The suitable collection time of root exudates andthe interfering ions affecting organic acid determination were determined. The method for removing theinterfering ions was established and analyzed. The release amount of root exudates increased with theincrease of collection time from 0 to 120 min but decreased with increasing of collection time from 120 to 240min. The maximum exuding amounts of organic acids were observed in root exudates at the collection time of120 min. There was a significant difference of organic acid components between the treatments of collectiontime of 120 min and 240 min. Citric acid was found only in the treatment of 120 min collection time. NO3-was the main interfering ion in organic acid determination and had the same retention time as oxalic acid.Anion exchangs resin (SAX) properly treated by HPLC (high performance liquid chromatography) solventcould remove NO3- anion in sample solution of root exudates, thus enhancing the recoveries of organic acidsin root exudates. There was no significant effect of the chemicals added into sample solution such as H3PO4,SAX and KNO3 on the retention time of organic acids.

Association between semen collection time and semen parameters:an observational study

The process of semen collection plays a key role in the quality of semen specimens.However,the association between semen collection time and semen quality is still unclear.In this study,ejaculates by masturbation from 746 subfertile men or healthy men who underwent semen analysis were examined.The median(interquartile range)semen collection time for all participants was 7.0(5.0-11.0)min,and the median time taken for semen collection was lower in healthy men than that in subfertile men(6.0 min vs 7.0 min).An increase in the time required to produce semen samples was associated with poorer semen quality.Among those undergoing assisted reproductive technology(ART),the miscarriage rate was positively correlated with the semen collection time.After adjusting for confounders,the highest quartile(Q4)of collection time was negatively associated with semen volume and sperm concentration.A longer time to produce semen samples(Q3 and Q4)was negatively correlated with progressive and total sperm motility.In addition,there was a significant negative linear association between the semen collection time and the sperm morphology.Higher risks of asthenozoospermia(adjusted odds ratio[OR]=2.06,95%confidence interval[CI]:1.31-3.25,P=0.002)and teratozoospermia(adjusted OR=1.98,95%CI:1.10-3.55,P=0.02)were observed in Q3 than those in Q1.Our results indicate that a higher risk of abnormal semen parameter values was associated with an increase in time for semen collection,which may be related to male fertility through its association with semen quality.