大豆粕在鲑鳟鱼类饲料中的利用

~~大豆粒在鲑鳟鱼类饲料中的利用@Ronald W.Hardy     

Variability in the spawning habitat of Pacific sardine (Sardinops sagax) off southern and central California

The spatial pattern of sardine spawning as revealed by the presence of sardine eggs is examined in relation to sea surface temperature (SST) and mean volume backscatter strength (MVBS) measured by a 150 kHz acoustic Doppler current profiler (ADCP) during four spring surveys off central and southern California in 1996–99. Studies in other regions have shown that MVBS provides an excellent measure of zooplankton distribution and density. Zooplankton biomass as measured by survey net tows correlates well with concurrently measured MVBS. The high along‐track resolution of egg counts provided by the Continuous Underway Fish Egg Sampler (CUFES) is a good match to the ADCP‐based data. Large interannual differences in the pattern and density of sardine eggs are clearly related to the concurrently observed patterns of surface temperature and MVBS. The strong spatial relationship between sardine eggs and MVBS is particularly evident because of the large contrast in zooplankton biomass between the 1998 El Niño and 1999 La Niña. The inshore distribution of sardine spawning appears to be limited by the low temperatures of freshly upwelled waters, although the value of the limiting temperature varies between years. Often there is an abrupt offshore decrease in MVBS that is coincident with the offshore boundary of sardine eggs. Possible reasons for this association of sardine eggs and high zooplankton biomass include an evolved strategy that promotes improved opportunity of an adequate food supply for subsequent larval development, and/or adult nutrient requirements for serial spawning. Hence, the distribution of these parameters can be used as an aid for delineating the boundaries of sardine spawning habitat.     

Production of Induced Secondary Metabolites by a Co-Culture of Sponge-Associated Actinomycetes,Actinokineospora sp. EG49 and Nocardiopsis sp. RV163

Two sponge-derived actinomycetes, Actinokineospora sp. EG49 and Nocardiopsis sp. RV163, were grown in co-culture and the presence of induced metabolites monitored by ¹H NMR. Ten known compounds, including angucycline, diketopiperazine and β-carboline derivatives 1–10, were isolated from the EtOAc extracts of Actinokineospora sp. EG49 and Nocardiopsis sp. RV163. Co-cultivation of Actinokineospora sp. EG49 and Nocardiopsis sp. RV163 induced the biosynthesis of three natural products that were not detected in the single culture of either microorganism, namely N-(2-hydroxyphenyl)-acetamide (11), 1,6-dihydroxyphenazine (12) and 5a,6,11a,12-tetrahydro-5a,11a-dimethyl[1,4]benzoxazino[3,2-b][1,4]benzoxazine (13a). When tested for biological activity against a range of bacteria and parasites, only the phenazine 12 was active against Bacillus sp. P25, Trypanosoma brucei and interestingly, against Actinokineospora sp. EG49. These findings highlight the co-cultivation approach as an effective strategy to access the bioactive secondary metabolites hidden in the genomes of marine actinomycetes.     

Hyperostotic bone disease in red pandas (Ailurus fulgens).

Three adult red pandas (Ailurus fulgens) developed multiple periarticular exostoses in their elbow joints. Two of these animals also had extensive periosteal new bone formation and osteosclerosis of the ulnae and radii and mild periosteal new bone deposition on the femurs. One animal also showed extensive hyperostosis of the cranium and mandibles. Dietary concentrations of calcium and phosphorus were estimated to be adequate, but dietary vitamin A and D appeared excessive when compared with recommended levels for this species. Serum vitamin A concentrations were not elevated in the two most severely affected animals, but their liver vitamin A content was higher than what is considered normal for most domestic animal species. Serum 25-hydroxy vitamin D concentrations were within normal ranges for domestic species. A definitive diagnosis for the cause of the lesions was not established, but hypervitaminosis A was suspected.     

Methods for selecting flower quality based on consumer evaluation

Summary The quality ranking of a sample of Gerbera cut-flowers varies greatly from one person to another. Further, there are significant differences between the rankings assigned by a panel of trained horticulturalists and a panel sampled from the general public. Therefore, the selection of a panel to evaluate the flower quality component of a breeding program is very important to the outcome. If the purpose of a program is to breed (those) flowers preferred by the general public then the selection of flowers should be done by a panel sampled from the general public. The prediction of consumer preferences by multiple linear regression techniques using eleven flower characters was not successful. Much greater predictive value was obtained by measuring the perceived information content of flowers. This indicates that flower characteristics which increase flower complexity may be preferred. Implications to the practical breeding program are discussed.     

Orientation and integration of the classical and molecular genetic maps of chromosome 11 in rice

Summary The classical genetic map and molecular map of rice chromosome 11 were oriented to facilitate the use of these maps for genetic studies and rice improvement. Three morphological markers (d-27, z-2, and la) were crossed to a rice breeding line, IRBB21, which has the Xa-21 gene for bacterial blight resistance. Three F₂ populations were analyzed with RFLP markers known to be located on chromosome 11. Segregation analysis of molecular markers and morphological markers was used to construct an RFLP map for each population. The recombination frequency between markers varied from population to population although the marker order on the maps was the same for all three populations. Based on a common set of markers mapped in the three populations, an integrated map was generated consisting of both RFLP and morphological markers. The genetic distance between markers on this map was determined by taking a weighted average of the data from the three populations. The oriented map serves as a bridge to understand the relationship between the classical and molecular linkage maps. Based on this information, the location of several genes on the classical map can be approximated with respect to RFLP markers without having to map them directly.     

Partitioning of penoxsulam, a new sulfonamide herbicide

Penoxsulam (trade name Granite) is a new acetolactate synthase (ALS) inhibitor herbicide for postemergence control of annual grasses, sedges, and broadleaf weeds in rice culture. This study was done to understand the equilibrium phase partitioning of penoxsulam to soil and air under conditions simulating California rice field conditions. Partitioning of penoxsulam was determined between soil and water (Kd) by the batch equilibrium method and between air and water (K(H)) by the gas-purge method. In four representative soils from the Sacramento Valley, the Kd values ranged from 0.14 to 5.05 and displayed a modest increase with soil pH. In soil amended with manure compost, soil sorption increased 4-fold with increasing soil organic matter content, but was still low with a Kd of 0.4 in samples with high organic carbon contents of 15%. Penoxsulam was confirmed to be extremely nonvolatile and did not partition into air at any measurable rate at 20 or 40 degrees C. K(H) (pH 7) was estimated at 4.6 x 10(-15) Pa x L x mol(-1) on the basis of available water solubility and vapor pressure data. The results imply that soil and air partitioning of penoxsulam do not significantly affect its potential for degradation or offsite movement in water.