No abstract

Independent and combined e¡ects of stocking density and algal concentration on the survival, growth and metamorphosis of the Bobu Ivory shell Babylonia formosae habei larvae were assessed using a 5 Â 5 factorial design with densities of 0.25, 0.5, 0.75, 1.00 and 1.50 larvae mL À 1 and algal concentrations of 5, 10, 15, 20 and 25 Â 10 4 cells mL À 1 in the laboratory. Larval growth, survival and metamorphosis were signi¢cantly a¡ected by both the independent e¡ects of stocking density and algal concentration and by their interaction. The highest per cent survival (72.5%) and metamorphosis (49.5%), fastest growth (41.57 mm day À 1 ) and shortest time to initial metamorphosis (10 days) all occurred at the lowest stocking density and the highest algal concentration. Both crowding and food limitation had independently negative impacts on the survival, growth and metamorphosis of larvae, and these negative impacts were further strengthened by the interaction of a higher stocking density and a lower algal concentration. Moreover, the results suggest that stocking density and algal concentration obviously played di¡erent roles in determining larval survival and growth. To maximize survival and growth, B. formosae habei larvae should be reared at a lower stoking density of 0.25 larvae mL À 1 and fed a higher algal concentration of 25 Â 10 4 cells mL À 1 in large-scale hatchery seed culture.

Juveniles of the scavenging gastropod Babylonia formosae habei (Altena & Gittenberger 1981) were kept at different ration levels in the laboratory for 30 days. Feeding behaviour and growth performance of the juveniles in relation to food availability were studied. Babylonia formosae habei juveniles were exposed to one of the four ration levels with food provided once either every 1, 2, 5 or 10 days. Higher food consumption, longer time spent on feeding and higher percentage of feeding individuals were obtained in individuals maintained at lower ration levels. Similar growth performances were observed in individuals fed once every day or every two days. A sustained production of shell was obtained in the juveniles maintained at low ration levels. At the end of the experiment, lower protein and lipid content as well as lower energy content were measured in the somatic tissue of juveniles maintained at lower ration levels. During the 30-day experiment, food availability is not a crucial factor on survival of juvenile B. formosae habei due to its physiological and behavioural adaptations developed in association with starvation

In recent years, information retrieval technology is widely used in the medical industry. How to effectively retrieve electronic medical record has become a hot issue in the field of information retrieval. Medical terms occupy an important position in the electronic medical record (EMR) retrieval, and they are usually used to limit the retrieval conditions, so they suggest the user's search intention. Aiming at the importance of medical terms, a method of query reformulation based on medical term reweighting is proposed to improve the performance of EMR retrieval. Firstly, the method filtrates medical terms from the origin query. Then, each medical term is weighted by its own self-information which can be estimated from the document set. Finally, the new query is constructed by combining the weighted medical terms and origin query proportionally. Experimental results on the TREC dataset show that our method performed above the baseline in three performance metrics: MAP (+ 14.2%), bpref (+ 8.0%), and P@10 (+ 9.6%).

Ultrasonic study on single phase ( Bi 0.85 Pb 0.15)2 Sr 2 Ca 2 Cu 3 O 10+x revealed that there are isothermal-like anomalies near 210 K in both velocity and attenuation of longitudinal and transverse sound waves. Specific heat measurements also showed clear anomaly at about 210 K, suggesting the occurrence of some structural changes or phase transition. Comparing with YBa 2 Cu 3 O 7−y, possible mechanisms are discussed.