生物系统中的对称性

该文是在讨论生物系统中的非线性问题(刘次全等, 1992)的基础上, 进而讨论生物系统的对称性问题. 重点分析了生物系统在分子层次的对称性以及在生命进化和发展中对称性逐步破缺的过程。

A scale to measure the attitude towards improved fish processing methods

An attitude scale was constructed to measure the attitude of fisherwomen towards improved fish processing methods. To construct the attitude scale, 'scale' and ‘Q’ values (the interquartile ranges) were calculated for 31 statements selected, based on the opinion of 34 judges. Based on the 'scale' and ‘Q’ values 16 statements were selected with eight favorable statements and eight unfavorable statements. The weightages given were 3, 2 and 1 for favorable statements and 1, 2 and 3 for unfavorable statements.

Kuguacins F-S, cucurbitane triterpenoids from Momordica charantia

Chemical investigation of the vines and leaves of Momordica charantia resulted in isolation of fourteen cucurbitane triterpenoids, kuguacins F-S (1-14), including two pentanorcucurbitacins (6 and 7), one octanorcucurbitacin (8), and two trinorcucurbitacin

大白蚁亚科云南省新记录种

描述了云南省大白蚁亚科新记录3个种,分别为近三型大白蚁、海南大白蚁,梯头大白蚁.

Ketamine affects memory consolidation: Differential effects in T-maze and passive avoidance paradigms in mice

The effects of ketamine, an N-methyl-D-aspartate (NMDA) antagonist, on memory in animals have been limited to the sub-anesthetic dose given prior to training in previous studies. We evaluated the effects of post-training anesthetic doses of ketamine to se

Effect of dietary inulin as prebiotic on growth, survival and intestinal bacterial density of juvenile great sturgeon (Huso huso)

Use of prebiotics, nondigestible dietary ingredients that beneficially affect the host by selectively stimulating the growth of and/or activating the metabolism of healthpromoting bacteria in the intestinal tract, is a novel concept in aquaculture. An 8-week feeding experiment was conducted to investigate the effects of dietary prebiotic inulin on the growth performance, intestinal bacterial density, body composition and values of blood serum enzymes in the juvenile great sturgeon (Huso huso). Three replicate groups of fish (initially averaging weight 16.14±0.38g) were fed diets containing prebiotic inulin at levels ranging from 1% to 3%. The basal diet was contained 3% cellulose. The results of linear regression showed there was a negative relationship between some performance indices including weight gain (WG), specific growth rate (SGR), protein efficiency ratio (PER), net protein utilization (NPU), energy retention (ERE), feed efficincy (FE), protein retention (PR) and supplementation level of inulin. At the end of trial, the 1% inulin treatment insignificantly showed an enhaced survival between the treatment groups. Intestinal lactic acid bacteria (LAB) increased in group treated with 1% inulin compare to other groups. No significant difference were observed in body composition and level of serum enzymes (P>0.05). Moreover there was significant correlation between ALT and LDH values (P<0.01). Result obtained in this study shows that the prebiotic inulin didn’t influence the increase of the growth performance of juvenile great sturgeon and it is not appropriate for supplementation in the diet of beluga.

兔受精卵显微注射外源基因后体外培养的卵裂发育

从超数排卵的14只母兔获得438枚受精卵, 卵龄16-22h。显微操作在带微分干涉和相差的Nikon倒置显微镜下进行。注射针的尖端外径0.5#mu#m, 离尖端40和80#mu#m处的外径分别为4.2和6.5#mu#m。注射用外源基因是绵羊生长激素基因与MT-1启动基因藕连的线状DNA溶液(1ng/#mu#l)。140枚注射的受精卵和未注射的145枚受精卵(对照), 在Ham^sF-10培养液(补充生长因子)中培养(38℃, 5％的CO_(2))。结果培养48h后, 注射组卵裂发育率分别是: 未卵裂7.9％(11/140)、卵裂至2-4细胞期11.0％(16/140)、卵裂至8-16细胞期80.7％(113/140)。对照组相应的卵裂率分别是4.1％(6/145)、12.4％(18/145)和83.4％(121/145)。两组卵裂发育率相近。

The nominal invalidity of the cyprinid genus, Parasinilabeo, with descriptions of a new genus and species

The nominal invalidity of the cyprinid genus, Parasinilabeo, with descriptions of a new genus and species. Zoological Studies 40(2): 134-140. A new genus, Pararectoris Su, Yang and Cui, is designated based on the type species, Pararectoris assimilis (Wu a

一种发光蚯蚓——磷微蠕蚓(Microscolex phosphoreus)体腔细胞的超微结构

下载PDF阅读器应用光学显微镜、扫描电镜和透射电镜对磷微蠕蚓(Microscolex phosphoreus)的体腔细胞进行观察,基于各种细胞的形态特征、胞质内细胞器和颗粒组成、伪足形状及行为特征等将其归纳为三类:黄色细胞、阿米巴样细胞、粒细胞.从外现土看,黄色细胞由几个个体较大的黄色细胞体组成,其细胞质内缺少细胞器;阿米巴样细胞呈明显球形或椭圆形的花朵状,经常可见几个至十几个细胞形成聚合体,胞质内细胞器丰富;粒细胞胞质的颗粒是其主要特征,其星状伪足常处于细胞一端,细胞质内细胞器含量比较丰富.本文将磷微蠕蚓的三类细胞与其它种蚯蚓中相关体腔细胞的形态和超微结构进行了异同比较.

The decline of Alestes baremose Boulenger, 1901 and Hydrocynus forskahlii (Cuvier, 1819) stocks in Lake Albert: implications for sustainable management of their fisheries

The fish stocks of Lake Albert face immense exploitation pressure which has led to “fishingdown” of their fisheries, with some larger species having been driven to near-extinction, while others such as Citharinus citharus have almost disappeared. Both A. baremose (Angara) and H. forskahlii (Ngassia) historically formed the most important commercial species in Lake Albert until the early 2000s but recent Catch Assessment Surveys (2007-2013) revealed a sweeping decline in their contribution to the commercial catch from 72.7% in 1971 to less than 6% in 2013. The catch per unit effort also registered a two-fold decline from 45.6 and 36.1 kg/boat/day to 22.6 and 18.1 kg/boat/day for A. baremose and H. forskahlii respective between 1971 and 2007. Over 50% of illegal gillnets, below the legal minimum limit of four inches (101.6 mm) used on Lake Albert target the two species. Gillnet experiments found the three inch (76.2 mm) gill net mesh size suitable for sustained harvest of the two species. The study concludes that optimal utilization of the two species and probably other non target fish species is achievable through species specific management strategies, coupling species specific licensing, and controlling harvest of juvenile individuals, overall fishing effort and fish catch on Lake Albert and protecting the vulnerable fish habitats.

A description of certain indigenous fishing methods from Southern Dahomey

A survey of certain Dahomean fishing methods showed them to be specifically adapted to the exploitation of floodplains and shallow water lagoons. Several types of fish-parks are described, ranging from small installations thaI funclion as refuge traps, to larger constructions that act as a form of fish culture. Ponds are also dug in the floodplains in order to conserve fish isolated during the dry season. These methods all give high yields and are worthy of consideration for use elsewhere on the African continent.