Hurricane Allen's Impact on Jamaican Coral Reefs

Coral reefs of north Jamaica, normally sheltered, were severely damaged by Hurricane Allen, the strongest Caribbean hurricane of this century. Immediate studies were made at Discovery Bay, where reef populations were already known in some detail. Data are presented to show how damage varied with the position and orientation of the substraturn and with the shape, size, and mechanical properties of exposed organisms. Data collected over succeeding weeks showed striking differences in the ability of organisms to heal and survive.     

用RAPD标记检测与杨树生长和物候期有关的QTLs

取美洲黑杨（母本）和青杨（父本）杂交获得的Ｆ２群体样本８０株,应用ＲＡＰＤ标记检测与Ｆ２群体３个数量性状（苗高、地径和封顶期）有关的ＱＴＬｓ。在Ｆ２九体中,一年生苗高、地径和封顶期性状表现显著分离,基本符合正态分布。单因子方差分析检测出与苗高、地径和封顶期性状相关的７个、６个和３个标记座位。并计算了各标记对相关性状变异的贡献率。与数量性状相关的标记有不同的亲本来源。ｔ检查结果各标记显带型和不显带型     

Productivity and quality of statice (Limonium sinuatum cv. Soiree Mix) and cockscomb (Celosia argentea cv. Chief Mix) under organic and inorganic fertilization regiments

Very little information is available on organic specialty cut flower production, especially fertilization requirements. In order to better understand organic fertilization requirements of two specialty cut flower crops, Limonium sinuatum and Celosia argentea, we initiated a field and greenhouse experiment to study the effect of compost (organic) and conventional (inorganic) fertilization treatments on the growth and productivity of these crops. Optimum yields in the field, expressed as fresh weight per plot, were achieved at compost applications of 98.8 t ha⁻¹ for both Limonium and Celosia. However, when number of stems, height of the stems, and the environmental impacts of such compost applications are considered we concluded that the optimal organic fertilizer amounts were 12.4 and 24.7 t ha⁻¹, for Limonium and Celosia, respectively. Limonium and Celosia plants in the greenhouse experiment were fertilized with 100, 200, 300, and 400 mg L⁻¹ nitrogen, combined with 0, 5, 10, 20, 40, and 60 mg L⁻¹ phosphorus. The generation of response surfaces for total weight per pot, number of stems per pot, average weight per stem, and average stem length were attempted for each species. The results showed that nitrogen did not significantly contribute to any of the models, except for Celosia average weight and length per stem models. Total weights per pot on the other hand showed both a linear and quadratic relationship over the range of phosphorus applications we tested. Maximum number of stems and total weight per pot were observed between 30 and 46 mg L⁻¹ P in both Limonium and Celosia. Our results suggest that organic fertilizer recommendations, in the form of animal manure composts should be based on phosphorus content of the compost rather than nitrogen content especially for soils high in initial phosphorous content.     

Recombinant bovine interleukin-12 stimulates a gut immune response but does not provide resistance to Cryptosporidium parvum infection in neonatal calves

This study was undertaken to determine if administration of recombinant bovine interleukin-12 (rBoIL-12) could stimulate a cellular immune response that protected calves from an oral challenge inoculation with Cryptosporidium parvum oocysts. In a first experiment, rBoIL-12 intraperitoneally administered as a single dose 1 day before challenge inoculation, did not alter the course of infection. The percentage of immune competent cells and levels of cytokine gene expression in the ileo-cecal mucosa and in the draining lymph nodes of treated calves were similar to those of untreated control calves. However, when rBoIL-12 was subcutaneously administered daily from 2 days before infection to 2 days after infection, a consistent increase of T lymphocytes and an higher expression of interferon-gamma (IFN-gamma) was detected. Again, treatment did not alter the course of infection. Similar results were obtained when rBoIL-12 was administered daily for 4 days beginning 2 days after oral inoculation. These data indicate that although rBoIL-12 stimulated a strong immune response in the gut of neonatal calves, the response was not able to provide protection from challenge inoculation with C. parvum oocysts.