Estimates of body sizes at maturation and at sex change, and the spawning seasonality and sex ratio of the endemic Hawaiian grouper (Hyporthodus quernus, F. Epinephelidae)

A case study of the reproductive biology of the endemic Hawaiian grouper or hapu’upu’u (Hyporthodus quernus) is presented as a model for comprehensive future studies of economically important epinephelid groupers. Specimens were collected throughout multiple years (1978–81, 1992–93, and 2005–08) from most reefs and banks of the Northwestern Hawaiian Islands. The absence of small males, presence of atretic oocytes and brown bodies in testes of mature males, and both developed ovarian and testicular tissues in the gonads of five transitional fish provided evidence of protogynous hermaphroditism. No small mature males were collected, indicating that Hawaiian grouper are monandrous (all males are sex-changed females). Complementary microscopic criteria also were used to assign reproductive stage and estimate median body sizes (L50) at female sexual maturity and at adult sex change from female to male. The L50 at maturation and at sex change was 580 ±8 (95% confidence interval [CI]) mm total length (TL) and 895 ±20 mm TL, respectively. The adult sex ratio was strongly female biased (6:1). Spawning seasonality was described by using gonadosomatic indices. Females began ripening in the fall and remained ripe through April. A February–June main spawning period that followed peak ripening was deduced from the proportion of females whose ovaries contained hydrated oocytes, postovulatory follicles, or both. Testes weights were not affected by season; average testes weight was only about 0.2% of body weight—an order of magnitude smaller than that for ovaries that peaked at 1–3% of body weight. The species’ reproductive life history is discussed in relation to its management.

Length-fecundity relationships of Nigerian fish populations

Parameters of the exponential body length (L)-fecundity (F) relationship of the form F=a.L super(b) are presented for 47 populations and 26 species of Nigerian fishes. Estimates of b varied between 1.563 (Ilisha africana) and 5.771 (Barbus callipterus) with a mean of 3.054 (s.d. = 1.024). The maximum sizes of fish populations examined did not significantly influence the relative magnitudes of b. The parameters Alpha and Beta of the linear length-fecundity relationships of the form F = Alpha + BetaL are also presented for five fish populations. Estimates of Beta ranged from 243.5 (Chrysichthys walkeri) to 1,334,895 (Tilapia mariae).

Distribution and Abundance of Steller Sea Lions, Eumetopias jubatus, on the Asian Coast, 1720's-2005

We analyzed published and archived records for the past 250 years to assess changes in distribution and abundance of Steller sea lions, Eumetopias jubatus, along the Asian coast from the Bering Strait to the Korean Peninsula. We found that the northern extent of Steller sea lion distribution has not changed but that the southern limit has moved north by some 500–900 km (~300–500 n.mi.) over the past 50 years. Additionally, the number of animals and their distribution has changed on the Commander Islands, Kuril Islands, and Kamchatka Peninsula. We found no changes in the number of rookeries in the northern Sea of Okhotsk, but a new rookery was established at Tuleny Island on the eastern coast of Sakhalin Island. We estimate that the total abundance of Steller sea lions along the Asian coast in the late 19th century was about 115,000 animals; during the 1960’s, the total estimate was about 27,000 (including pups), most of which were in the Kuril Islands. The fewest number of Steller sea lions occurred in the northwestern Pacific in the late 1980’s–early 1990’s when only about 13,000 individuals (including pups) were estimated in the entire region. During the 1990’s, and especially in early 2000, an increasing trend in abundance occurred in most areas. Present estimated abundance of Steller sea lions in Asia is about 16,000 individuals (including about 5,000 pups), about half of which occur in the Kuril Islands. Changes in abundance occurred during all time periods but varied by site and period. Specifically, over the past 150 years Steller sea lion abundance at most sites has changed. There were no rookeries on the Commander Islands between 1850 and 1960 and abundance was low, but by 1977, abundance increased to 4,800 individuals and a rookery was established in the mid 1980’s; abundance there has declined since the early 1980’s and in 2004 only 895 individuals (including 221 pups) were counted during the breeding season. Between 1940 and 2004, abundance along the eastern coast of Kamchatka declined from ~7,000 to ~600 individuals, an overall reduction of 90%. Steller sea lion abundance on the Kuril Islands declined by >90% from the 1800’s to 2005; the most severe decline there occurred during 1969–1981. Steller sea lion numbers in the northern part of the Sea of Okhotsk declined during 1930–2002 from 7,200 to 3,100 individuals. Numbers at Tuleny Island have increased since establishment of a rookery there during 1983–2005 and by immigration from other sites.

高等植物PSI颗粒的分离提纯及其光破坏机理的初步探讨

从菠菜叶绿体中分离提纯PSI颗粒及其捕光天线色素蛋白复合物LHCI，对其光谱特性进行分析。对PSI颗粒中色素和蛋白的光破坏进程，并对外加组氨酸、Triton，以及温度对PSI颗粒光破坏的影响等进行了比较系统的研究，以探讨PSI光破坏的机理。其主要结果如下： 1. 对PSI颗粒和LHCI色素蛋白复合物的荧光光谱的研究，发现PSI中Chlb所吸收的光能主要传递给LHCI中的“长波组分”（吸收波长大于P700的Chla）。 2. 在PSI颗粒光破坏进程的研究中发现，Chla中吸收波长较长的组分首先发生光破坏;位于PSI颗粒外围的LHCI上的Chlb，也容易受到光破坏;Car先于Chlb发生光破坏。在光照处理过程中，PSI的天线色素蛋白复合物LHCI多肽降解程度大于反应中心多肽组分（PsaA，PsaB）的降解，其中LHCI-680首先由于光破坏而发生降解。PsaD也是容易受到光破坏而发生降解的一个多肽。另外，还发现在长时间光照后有蛋白聚合现象发生。 3. 在PSI颗粒中外加单线态氧的淬灭剂组氨酸，分析不同光强光照处理过程中组氨酸对PSI颗粒中色素和多肽光破坏的保护作用，发现外加组氨酸对强光照（2300μEm-2s-1）引起的叶绿素光吸收减少和CD信号减弱的有效抑制表现出一个明显的延迟期，但对强光诱导的荧光产量下降的效应却能立即表现出来;在强光照前期和弱光照（300μEm-2s-1）条件下，组氨酸不能抑制PSI颗粒的光吸收下降。另外，外加组氨酸除了对反应中心多肽有光保护作用以外，对PSI中其它多肽也有显著的保护作用。 4. 用不同浓度的Triton处理PSI颗粒，发现较低浓度的Triton可以增大叶绿素的光吸收和PSI颗粒的荧光产量，而不对PSI颗粒的多肽组成造成影响;当Triton浓度达到一定的程度时，虽然不会影响PSI颗粒的多肽组成，但是会使其光吸收减少，荧光产量下降;而当Triton浓度过高时，PSI颗粒的多肽会发生降解现象，同时其光吸收和荧光产量也迅速下降。Triton浓度较低时，PSI颗粒光破坏的程度随Triton浓度的增大而增大，当Triton浓度增大到一定的程度时，PSI颗粒的光破坏程度同Triton浓度不再呈明显的正相关。 5. 对PSI颗粒进行不同温度的热处理，其结果表明：温度较低（20 ℃～40 ℃）的热处理对PSI颗粒的多肽和叶绿素光吸收的影响程度很小，照光后不同温度热处理过的PSI颗粒光吸收减少和多肽降解的程度相近;温度较高（50 ℃～60 ℃）的热处理会对PSI颗粒的结构产生影响，使之稳定性减小，对光处理更敏感;温度更高（大于70 ℃）的热处理会破坏PSI颗粒的结构，引起多肽组分的降解。另外，不同的多肽对热处理的敏感性显著不同。 6. 低温（4 ℃）和常温（20 ℃）下PSI颗粒光破坏的比较发现，室温下PSI颗粒的光破坏程度明显大于低温下光破坏的程度，表明光处理过程中温度会影响到PSI颗粒光破坏的程度。 通过上述的研究结果，分析了PSI颗粒光破坏过程中色素和蛋白的变化及其外界因子的影响，对PSI颗粒光破坏的机制进行了初步的探讨。

阶跃管型毫微秒过零甄别器

本实用新型涉及一种阶跃管型毫微秒过零甄别器，其过零甄别信号电路板可装成Ｎｉｍ插件上，在插件面板上设有信号输入插孔和输出插孔；其甄别信号电路是由输入的信号经二极Ｄ↓［１］、Ｄ↓［２］组成限幅器限幅后，再与三极管Ｎ↓［１］的基极相连，三极管Ｎ↓［１］的集电极输出的放大信号与由三极管Ｎ↓［２］、Ｐ↓［１］组成的射极跟随器的基极相连，在三极管Ｐ↓［１］、Ｎ↓［２］的射电极相连点与地之间串联有反偏／正偏的阶跃二极管Ｉ↓［１］，由阶跃二极管Ｉ↓［１］的一端与阻抗匹配网路Ｒ↓［１４］、Ｃ↓［４］相联，由其输出信号与输出插孔相联；该甄别器利用阶跃型二极管实现过零、其前沿时间快至８００Ｐｓ左右、时间特性好、游动小。

非晶状体βγ-晶状体蛋白与三叶因子蛋白复合物的细胞核转运及其选择性杀伤肿瘤细胞机制的研究

非晶状体βγ晶状体蛋白与三叶因子蛋白复合物(βγ-CAT)是从大蹼铃蟾(Bombina maxima)皮肤分泌物中分离的分子量为72 kDa的天然蛋白复合物.本研究通过激光共聚焦显微镜和Westem blot分析βγ-CAT在人脐静脉内皮细胞(HUVEC)中的细胞核转运机制,以及βγ-CAT对多株肿瘤细胞(HCT116,HT29,A375,Hela,THP-1等)的细胞毒效应.结果表明:βγ-CAT的α亚基中含有典型的GTP/ATPase的保守结构模体Walker A和Walker B,体外检测到βγ-CAT具有GTP/ATP水解酶和GTP/ATP结合活性.在细胞核转运过程中,βγ-CAT的α亚基和β亚基参与形成约150kDa含有泛素化修饰信号的大分子复合物,且泛素化修饰信号和βγ-CAT的α亚基和β亚基共定位于细胞内和融合于细胞核区域的转运囊泡小体中.βγ-CAT能够选择性的杀伤肿瘤细胞,诱导肿瘤细胞脱落和发生凋亡.上述结果为进一步深入研究阡βγ-CAT的细胞核转运和调节细胞功能的分子作用机制提供思路和线索.

灵长类和反刍动物生长激素受体的快速进化

在大部分哺乳动物的进化历程中, 垂体生长激素的进化非常缓慢, 各类群之间没有很大的差别, 但在灵长类和反刍动物的进化过程中却出现了明显的快速进化, 即所谓“插曲式”的进化模式. 我们获 得了4 种灵长类动物的生长激素受体的膜外区序列, 并结合已有的序列数据进行系统的进化分析, 结果 表明, 哺乳动物生长激素受体也经历了一种类似垂体生长激素的所谓“插曲式”的进化模式. 考虑到垂 体生长激素的生物学效应需要通过其受体的介导才能实现, 结合相关性分析的结果, 推测垂体生长激 素受体的这种进化模式可能是与垂体生长激素发生了协同进化的结果.垂体生长