Detour behavior changes associated with prenatal morphine exposure in 11-day-old chicks

The central nervous system exhibits remarkable plasticity in early life. Prenatal morphine exposure may induce adverse behavioral effects on the neonate and the developing offspring. In the present study, we investigated the effect of prenatal morphine exposure (daily from embryonic days 12-16, 20 mg/kg) on 11-day-old chicks using two forms of spatial paradigms: one trial detour behavior task in which animals must bypass an obstacle to reach the desired goal without any training and detour learning task which required several trials of training to reach the detour criterion. The results showed that, on the condition that chicks could successfully detour in the first trial, morphine exposed chicks exhibited longer detour latency to finish the task, coupled by a preference for turning right versus turning left. In contrast, no significant difference in learning and memory was found in detour learning task between morphine exposed chicks and saline chicks. These findings suggest specific behavioral changes associated with prenatal exposure to opioids during mid to late gestation, also raise attention to the possible health hazard from pregnancy drug use in everyday life. (C) 2010 ISDN. Published by Elsevier Ltd. All rights reserved.

HSF2 mRNA 在热应激和大剂量11酸睾酮诱导恒河猴生精细胞凋亡中的表达变化

为了探讨 HSF2 mRNA 在热应激和超生理剂量睾酮诱导恒河猴生精细胞凋亡中的表达变化, 作者建立了手术诱导单侧隐睾和注射大剂量11酸睾酮(TU)恒河猴动物模型, 应用3′末端标记分析(TUNEL)和原位杂交方法, 检测睾丸细胞的凋亡信号和 HSF2的表达变化. TUNEL 结果显示热应激和超生理剂量睾酮能够诱导生精细胞出现凋亡信号, 它分别于处理后第5天和第30天达到最强, 表明热应激和睾酮干扰精子发生可能是通过生精细胞凋亡的方式来实现的. HSF2 mRNA 水平在生精细胞凋亡早期(凋亡信号达到最强以前)略有降低, 而在凋亡高峰期之后其表达急剧下降. Hsf2基因与作者以前研究的 Hsp70-2基因的表达具有时间上的相关性, 表明 HSF2蛋白可能调控 Hsp70-2基因的表达, 而且 HSF2可能通过多种方式影响精子的发生以及抑制生精细胞的凋亡。

P16蛋白和生精细胞凋亡对热压和11酸睾酮诱导的恒河猴无精子症和少精子症中的作用

探讨了P16蛋白和生精细胞凋亡在热压和11酸睾酮诱导恒河猴无精子症和少精子症中作用间的关系。3^末端标记分析(TUNEL)结果显示热应激和超生理剂量睾酮能够诱导生精细胞出现凋亡信号,它分别于处理后d5和d30达到最强。免疫组化结果显示,热压或TU主要诱导精原细胞和其它生精细胞以及Sertoli细胞P16的表达。P16蛋白的表达在生精细胞凋亡晚期,即隐睾手术d10或注射TUd60后迅速升高并维持高表达,该蛋白在生精细胞凋亡晚期可能通过抑制精原细胞的有丝分裂,扰乱正常的精子发生。

鲢鱼放养控制北京城市河湖水华试验研究

介绍了利用鲢鱼控制北京城市河湖水华的试验研究,通过不同放养密度(0、17、51和103 g/m3)的现场围隔试验,对鲢鱼放养对水体水质和浮游生物的影响进行了分析。研究结果表明,鲢鱼放养使有鱼围隔中浮游生物量极低,从而使浮游植物基本不受浮游动物影响,而直接受鱼类影响;同时,中等密度(51 g/m3)的鲢鱼放养使水华蓝藻和微小藻的生长均得到了有效抑制,使藻类生物量最低。

白鲫(♀)×红鲫(♂)异源四倍体鱼的倍性操作及其生殖力的研究

采用热休克调控技术诱导出103尾第一代白鲫（♀）×红鲫（）异源四倍体鱼，并对其生殖力进行了研究。1或2龄的四倍体雄鱼能产生精子，而雌鱼不能产生正常的卵。将异源四倍体雄鱼与二倍体白鲫雌鱼交配产生倍间三倍体鱼，染色体检查证明是整三倍体（3N＝150），但其受精率很低（11．4—51．3％，平均32．4％）．网箱养殖结果表明，倍间三倍体白鲫的生长速度比白鲫快30％以上，雌雄均不育．并用冷休克处理回收异源四倍体4N（）×白鲫2N（♀）受精卵的第二极体产生了新的四倍体鱼．文中还对第一代异源四倍体鱼的批量生产、生殖能

异育银鲫对鱼粉等11种饲料中磷的利用率

于1988年,以三氧化二铬间接指示法,在水温22±2℃条件下,测定了平均体重为55±5g/尾的异育银鲫对鱼粉、肉骨粉、芝麻饼、虾粉、骨粉、菜籽饼、玉米粉、脱氟磷酸氢钙、磷酸二氢钙、磷酸氢钙、磷酸钙的表观消化吸收率。结果表明:异育银鲫对第一、第二、第三磷酸钙的消化吸收率是不同的,分别为81％,65％和32％,此顺序与其溶解性由大到小的顺序一致;在所测试的八种商品饲料中,对骨粉、虾粉和菜籽饼中磷的表观消化吸收率较高,分别为65％,68％和65％;对鱼粉、芝麻饼、肉骨粉三种原料中磷的表观消化吸收率较低,分别是1

Morphology, biometry and distribution of Difflugia biwae Kawamura, 1918 (Protozoa : Rhizopoda)

The freshwater testate amoeba Difflugia biwae Kawamura, 1918, isolated from Mulan Lake, Hubei Province, China is investigated using light microscopy and scanning electron microscopy. The morphology, biometry and distribution of this little known species are supplied. After careful comparison with three other similar species, including D. delicatula Gauthier-Livre et Thomas, D. elegans Penard and D. oblonga caudata Stepanek, we believe that the characteristics of smooth fusiform shell, conspicuous great collar flare (always larger than body-width) around the aperture, constriction behind the aperture and a somewhat curved aboral horn set D. biwae apart from all other Difflugia species. This species shows a great diversity in total length, collar height and aboral horn length which have high variability (CV between 11.76 and 24.52). However, body width, collar diameter, neck width, body length and aperture diameter are fairly constant with low variability (CV between 5.34 and 8.79) which shows a remarkable uniformity of D. biwae. Also, the size frequency distributions of both body width and body length yield bell-shaped (normally distributed) curves and indicate that D. biwae is a size-monomorphic species, characterized by a main-size class and a small size range. D. biwae is probably endemic to East Asia (China and Japan) because it has such a large size (165-306 mu m) that it would have been easily found in Europe and North America, if it were there. Consequently, D. biwae must have a restricted geographical distribution, disproving the old hypothesis that microscopic organisms are cosmopolitan.

Enhanced resistance to Aeromonas hydrophila infection and enhanced phagocytic activities in human lactoferrin-transgenic grass carp (Ctenopharyngodon idellus)

Human lactoferrin (hLF) is an iron-binding protein with antimicrobial and immunomodulatory activities. hLF cDNA was transferred into grass carp via electroporated sperm. The production of transgenic fish was as high as 55% tinder the best parameters. 2(11) pulses and 20-min incubation. The expression of the transgene was demonstrated by the detection of hLF mRNA by RT-PCR. We also investigated the response of G(0) transgenic grass carp to Aeromonas hydrophila infection. Serum lysozyme activities (P>0.05) and phagocytic activities of kidney cells (P<0.05) were measured in transgenic individuals. The transgenic fish not only cleared A. hydrophila significantly faster than the control carp (P<0.05), but also showed enhanced phagocytic activities. The result shows that hLF has immunomodulatory activities in hLF-transgenic grass carp. The transgenic grass carp exhibited enhanced immunity to A. hydrophila infection. These results reveal that the mechanisms of disease resistance are different between hLF-transgenic plants and hLF-transgenic grass carp. (C) 2004 Elsevier B.V. All rights reserved.

Small SiGe quantum dots obtained by excimer laser annealing

In this paper, we obtain SiGe quantum dots with the diameters and density of 15-20 nm and 1.8 x 10(11) cm(-2), respectively, by 193 nm excimer laser annealing of Si0.77Ge0.23 strained films. Under the excimer laser annealing, only surface atoms diffusion happens. From the detailed statistical information about the size and shape of the quantum dots with different annealing time, it is shown that the as-grown self-assembled quantum dots, especially the {105}-faceted dots, are not stable and disappear before the appearance of the laser-induced quantum dots. Based on the calculation of surface energy and surface chemical potential, we show that the {103}-faceted as-grown self-assembled quantum dots are more heavily strained than the {105}-faceted ones, and the heavy strain in the dot can decrease the surface energy of the dot facets. The formation of the laser-induced quantum dots, which is also with heavy strain, is attributed to kinetic constraint. (c) 2008 Elsevier B.V. All rights reserved.

Effects of polarization field on formation of two-dimensional electron gas in (0001) and (11(2)over-bar0) plane AlGaN/GaN heterostructures

Photoluminescence (PL) and temperature-dependent Hall effect measurements were carried out in (0001) and (11 (2) over bar0) AlGaN/GaN heterostructures grown on sapphire substrates by metalorganic chemical vapor deposition. There are strong spontaneous and piezoelectric electric fields (SPF) along the growth orientation of the (0001) AlGaN/GaN heterostructures. At the same time there are no corresponding SPF along that of the (1120) AlGaN/GaN. A strong PL peak related to the recombination between two-dimensional electron gas (2DEG) and photoexcited holes was observed at 3.258 eV at room temperature in (0001) AlGaN/GaN heterointerfaces while no corresponding PL peak was observed in (11 (2) over bar0). The existence of a 2DEG was observed in (0001) AlGaN/GaN multi-layers with a mobility saturated at 6000 cm(2)/V s below 80 K, whereas a much lower mobility was measured in (11 (2) over bar0). These results indicated that the SPF was the main element to cause the high mobility and high sheet-electron-density 2DEG in AlGaN/GaN heterostructures. (C) 2004 Elsevier B.V. All rights reserved.

Luminescence study of (11(2)over-bar0) GaN film grown by metalorganic chemical-vapor deposition

Investigations on photoluminescence properties of (11 (2) over bar0) GaN grown on (1 (1) over bar 02) Al2O3 substrate by metalorganic chemical-vapor deposition are reported. Several emission lines not reported before are observed at low temperature. The sharp peak at 3.359 eV is attributed to the exciton bound to the neutral acceptor. Another peak at 3.310 eV represents a free-to-bound, probably a free electron-to-acceptor, transition. The 3.241 and 3.170 eV lines are interpreted as phonon replica lines of the 3.310 eV line. The phonon energy is 70 meV, consistent with the energy of transverse optical E-1 phonon. The optical properties of the lines are analyzed. (C) 2003 American Institute of Physics.

A two-step backoff scheme for improving the performance of the IEEE 802.11 distributed coordination function

This paper describes the binary exponential backoff mechanism of 802.11 distributed coordination function (DCF), and introduces some methods of modifying the backoff scheme. Then a novel backoff scheme, called Two-step Backoff scheme, is presented and illustrated. The simulation process in OPNET environment has been described also. At last, the analysis and simulation results show that the Two-step backoff scheme can enhance the performance of the IEEE 802.11 DCF.