A comparative study on the rumen microbial populations,hydrolytic enzyme activities and dry matter degradability between different species of ruminant

A comparative study among Korean native cow (Hanwoo), Holstein dairy cow, Korean native goat and crossbred sheep on the population and marker concentration of ruminal microbes, the activities of carboxymethylcellulase (CMCase), xylanase and amylase, and in situ dry matter (DM) degradability were conducted. Twelve ruminally cannulated animals, three of each species, were used. Animals were fed the same diet containing 40% formula feed and 60% rice straw at the level of 2.5% of body weight. Total viable microbial populations in the rumen fluid were significantly (P < 0.01) greater for bacteria and fungi in goat than those of Holstein. The protozoan population among ruminant species was the reverse from that of bacteria. The concentrations of 2,6‐diaminopimelic acid and chitin as markers for bacteria and fungi in the rumen fluid, respectively, were highest in goat, which is in accordance with the above population data. The concentration of aminoethylphosphonic acid as marker of protozoa was highest in Hanwoo and lowest in sheep (P < 0.01). Goat had the highest (P < 0.01) activities of all the enzymes investigated among ruminants. In situ effective degradation of the DM of rice straw was approximately 19% higher in the rumen of goat compared with other animals.     

Unrecognized diversity in New Guinean crayfish species (Decapoda,Parastacidae): The evidence from molecular data

The phylogenetic relationships among imported ornamental crayfish belonging to the genus Cherax were inferred from a combined dataset of 3 mitochondrial genes (COI, 16S and 12S) and by comparison with available GenBank sequences of 14 Cherax species. Furthermore, the concordance of previously described species obtained from a wholesaler (Cherax boesemani, C. holthuisi and C. peknyi) with available GenBank sequences was verified based on COI with special respect to comparison with sequences assigned as Cherax species. Recently described species C. gherardiae, C. pulcher and C. subterigneus belong to the northern group of Cherax species. Comparison and analysis with other GenBank COI sequences show previously unreported diversity of New Guinean species, suggesting 5 putative new species. Surprisingly, species assigned to the subgenus Astaconephrops do not form a monophyletic clade; this subgenus should be reappraised relative to the purported typical morphological characteristic of the uncalcified patch on male chelae. Increasing importation of crayfish underscores the importance of accurate species identification. Use of basic molecular methods is a necessary requisite for documenting occurrence, abundance and population trends of target species. Consequently, it helps to support eventual conservation decision‐making by stakeholders.     

Identifying autism loci and genes by tracing recent shared ancestry

To find inherited causes of autism-spectrum disorders, we studied families in which parents share ancestors, enhancing the role of inherited factors. We mapped several loci, some containing large, inherited, homozygous deletions that are likely mutations. The largest deletions implicated genes, including PCDH10 (protocadherin 10) and DIA1 (deleted in autism1, or c3orf58), whose level of expression changes in response to neuronal activity, a marker of genes involved in synaptic changes that underlie learning. A subset of genes, including NHE9 (Na+/H+ exchanger 9), showed additional potential mutations in patients with unrelated parents. Our findings highlight the utility of "homozygosity mapping" in heterogeneous disorders like autism but also suggest that defective regulation of gene expression after neural activity may be a mechanism common to seemingly diverse autism mutations.     

丙烯酸松香的溴化及产物的阻燃性研究

以丙烯酸松香与液溴加成,合成了溴化丙烯酸松香;研究了反应温度、原料的物质的量比、反应时间等因素对反应过程及产物性能的影响.用FT-IR、1 HNMR和热重分析(TG)等对溴化丙烯酸松香进行了表征.结果表明,当反应温度为-2 ～ 4℃、反应时间5 ～ 6h、液溴与丙烯酸松香的物质的量比值约为1.2时,收率可达93%.溴化丙烯酸松香不仅具有较好的阻燃性,同时还拓宽了松香的应用范围,提高了其附加值.     

-蒎烯氧化制备诺蒎酸

利用水和叔丁醇的混合溶液作为反应的溶剂,用高锰酸钾氧化β-蒎烯制备诺蒎酸,考察了叔丁醇含量、高锰酸钾和碱用量以及温度对产物收率的影响.最佳反应条件:反应温度15～25 ℃,β-蒎烯、KMnO4、NaOH物质的量的比为1:3:1.5,用 30 % 的叔丁醇水溶液做溶剂,诺蒎酸的收率(质量分数)在 70.0 % 以上.     

用β-蒎烯为原料合成高纯度对异丙基苯酚

研究了以松节油中β-蒎烯为原料，通过氧化、酸催化开四元环和脱氢三步反应，合成了高纯度对异丙基苯酚，总产率达到31％。并对酸催化开四元环和脱氢步骤中各因素对反应的影响进行了探讨。发现诺蒎酮开四元环转化反应选择在40％的磷酸溶液催化下，80℃反应1h效果较好，产率达到67．9％。4-异丙基环己烯酮与硫脱氢生成对异丙基苯酚，反应选择密封反应2h效果较好，产率达到63％。     

不同氮肥施用量对青花菜氮肥利用率、氮素含量及产量的影响

为了探明不同氮肥施用量对青花菜氮肥利用率、氮素含量和产量的影响,试验设置5个水平,分别为667 m2施0、5、10、20、30 kg,利用相关性分析及回归方程了解氮肥对青花菜的影响。结果表明,氮肥施用量与氮肥利用率间呈显著负相关,与花球中氮素含量呈极显著正相关。青花菜的氮肥效应方程为:Y=-0.829 5X2+33.17 1X+543.55,在其他条件相同的情况下,667 m2氮肥施用量为19.46 kg,青花菜达到最大收益。     

土地变更调查中存在的问题及建议——以原州区为例

以固原市原州区土地变更调查为例,从技术人才、经费投入、变更调查、加强管理等方面进行了分析,提出存在的问题和建议,供今后土地变更调查借鉴。     

痕量灌溉管不同埋深对日光温室沙培黄瓜的影响

以微喷灌溉(CK)为对照,研究痕量灌溉管在沙培中不同埋深对日光温室春季黄瓜生长、产量和水分生产效率等的影响.结果表明,T3处理(25cm)的黄瓜生长与CK(微喷)相比受到显著抑制,T1 (5cm)、T2(15cm)处理黄瓜生物积累量、叶片净光合速率、果实品质与CK相比均有所提高,不同处理间叶片电导率、MDA、根系活力差异不显著,T1、T2、T3处理沙子含水量均低于CK;T1处理的产量比T2处理提高了1.9％;与CK相比的T1、T2处理水分生产效率分别提高50.9％、60.0％.分析表明,日光温室沙培黄瓜栽培中痕量灌溉管埋设深度为5 cm最佳.