可修正跟踪精度的低成本全天候太阳跟踪控制系统研制

为了降低太阳跟踪系统的成本和复杂程度,以模拟电路及光电转换原理为基础,研制了一种跟踪精度可调整的全天候太阳跟踪控制系统和T-L型太阳方位探测器,并通过光斑检测试验,对该系统的跟踪性能进行了分析,试验方法是将底部带小孔的一次性纸杯粘贴在带无数同心圆的纸上,将纸固定在双轴跟踪支架上,进而观察光斑在同心圆上的位置随时间的变化。研究结果表明:该系统的跟踪精度与太阳辐射强度有关,太阳辐射强度越大跟踪精度越高,太阳辐射强度越小跟踪精度越差,一天中的最小跟踪精度可达0.14°。该系统适合于对跟踪精度要求不是特别苛刻,并且对跟踪控制系统有廉价要求的场合,为太阳跟踪控制系统的普及奠定基础。     

弱相依序列最大值的几乎处处中心极限定理

设{εi}i^∞=1 为弱相依平稳随机变量序列,{un}为给定的实数序列,在条件D’（un）和D2（{uk,un}）之下,研究了弱相依序列最大值的几乎处处中心极限定理．     

The interrelation between temperature regimes and fish size in juvenile Atlantic cod (<Emphasis Type="Italic">Gadus morhua</Emphasis>): effects on growth and feed conversion efficiency

The present paper describes the growth properties of juvenile Atlantic cod (Gadus morhua) reared at 7, 10, 13 and 16 °C, and a group reared under “temperature steps” i.e. with temperature reduced successively from 16 to 13 and 10 °C. Growth rate and feed conversion efficiency of juvenile Atlantic cod were significantly influenced by the interaction of temperature and fish size. Overall growth was highest in the 13 °C and the T-step groups but for different reasons, as the fish at 13 °C had 10% higher overall feeding intake compared to the T-step group, whereas the T-step had 8% higher feeding efficiency. After termination of the laboratory study the fish were reared in sea pens at ambient conditions for 17 months. The groups performed differently when reared at ambient conditions in the sea as the T-step group was 11.6, 11.5, 5.3 and 7.5% larger than 7, 10, 13 and 16 °C, respectively in June 2005. Optimal temperature for growth and feed conversion efficiency decreased with size, indicating an ontogenetic reduction in optimum temperature for growth with increasing size. The results suggest an optimum temperature for growth of juvenile Atlantic cod in the size range 5–50 g dropping from 14.7 °C for 5–10 g juvenile to 12.4 °C for 40–50 g juvenile. Moreover, a broader parabolic regression curve between growth, feed conversion efficiency and temperature as size increases, indicate increased temperature tolerance with size. The study confirms that juvenile cod exhibits ontogenetic variation in temperature optimum, which might partly explain different spatial distribution of juvenile and adult cod in ocean waters. Our study also indicates a physiological mechanism that might be linked to cod migrations as cod may maximize their feeding efficiency by active thermoregulation.     

麦岩螨种群密度效应及防治指标的研究

研究结果表明：麦岩螨种群密度与其寿命、繁殖、迁逃等关系密切，随着种群密度的增加，麦岩螨卵的孵化率降低，初孵幼螨死亡率增加，雌成螨繁殖力下降，寿命缩短，扩散迁逃率增加，其危害密度为每株小麦２０￣４０头及其以下。防治指标为：返青期百茎螨量１４００头，危害指数为１％；拔节期百茎螨量６７００头，危害指数为６．５％。     

不同品种育成猪基线免疫性状的比较

为了比较不同品种育成猪基线免疫指标的差异,研究选用巴马香猪、本地黑猪和杜长大3个品种育成猪,采用显微镜平板计数法计数红、白细胞总数;血涂片法测定白细胞分类计数;EA花环形成试验检测B淋巴细胞的百分率;流式细胞仪检测T淋巴细胞亚群百分率。结果表明:巴马香猪红细胞总数(RBC)、中性粒细胞百分率(GR%)、嗜酸性粒细胞百分率(EO%)以及T淋巴细胞亚群CD4+、CD8+百分率(CD4+%、CD8+%)等5项指标与本地黑猪、杜长大t检验差异显著(P<0.05),其中RBC和GR%显著高于本地黑猪和杜长大,EO%以及CD3+%、CD4+%、CD8+%显著低于本地黑猪和杜长大(P<0.05)。B淋巴细胞百分率(BLY%)显著低于本地黑猪,嗜碱性粒细胞(BASO%)显著低于杜长大,而白细胞总数(WBC)、淋巴细胞百分率(LY%)、单核细胞百分率(MO%)和CD4+/CD8+等4项指标与本地黑猪、杜长大基本一致。对本地黑猪与杜长大进行比较发现,WBC与BYL%2项差异显著。说明品种是影响基线免疫性状的一个重要因素,但对同一品种猪,各项指标间没有相关性。     

Evidence of density-dependent effects on population variation of Japanese sardine (Sardinops melanosticta) off Korea

Interannual variation of some biological parameters for the Japanese sardine, Sardinops melanosticta, population in Korean waters was investigated using scientific surveys and fisheries information since the late 1970s. The abundance and geographical coverage of sardine eggs were high (peak in 1986) and broad when spawning biomasses were high in the mid 1980s, and vice versa in the late 1970s and the early 1990s. Also, feeding and spawning areas based on fisheries information exhibited the same pattern of expansion/contraction as seen in ichthyoplankton surveys. Annual Gonadal Somatic Index (GSI) in spawning season (February to April) and the size at age 1 of sardine were reduced during the high abundance period. It is suggested that density‐dependent effects on the reproduction and growth of the sardine population in Korean waters existed.     

Role of Cdk5-CRMP pathway in sevoflurane-induced dendritic developmental disorder of neurons in prefrontal cortex of neonatal rats

AIM: To investigate the effect of sevoflurane (Sevo) on the dendritic development in prefrontal cortex (PFC) of neonatal rats and the role of cyclin dependent kinase 5 (Cdk5)- collapsin response mediator protein (CRMP) pathway in it. METHODS: Eighty-eight postnatal day 7 Sprague Dawley (SD) rats were randomly divided into 4 groups (n=22): Air+NS group, Air+roscovitine (Ros) group, Sevo+NS group and Sevo+Ros group. The rats in Air+NS group and Air+Ros group were exposed to the air for 4 h, while the rats in the other 2 groups were exposed to 2.8% sevoflurane for 4 h. The rats received intraperitoneal injection of 150 μL normal saline 15 min before exposure in the Air+NS group and Sevo+NS group, while the rats in the Air+Ros group and Sevo+Ros group received intraperitoneal injection of 150 μL roscovitine (in DMSO solution, 10 mg/kg) 15 min before exposure. At the end of exposure, the cortices of the rat brain were collected and the protein levels of P35, P25, Cdk5, CRMP1, CRMP2, CRMP4 and p-CRMP2 Ser522 in PFC were detected by Western blot. On the postnatal day 30, the rat brains were sectioned for Golgi-Cox staining and morphological analysis of dendrites in the PFC neurons. Open-field test and contextual fear conditioning test were performed on postnatal days 25~27 and 31~32, respectively. RESULTS: Compared with Air+NS group, the expression of P35 in the Sevo+NS group was significantly decreased, and the expression of P25 was dramatically increased (P <0.05), whereas roscovitine partly reversed the changes above induced by sevoflurane (P <0.05). The expression of Cdk5 was not significantly different among all groups. Compared with the Air+NS group, the expression of CRMP1, 2, and 4 in the Sevo+NS group were decreased, and the protein level of p-CRMP2 Ser522/CRMP2 was increased (P <0.05), whereas roscovitine partly reversed the changes above induced by sevoflurane (P <0.05), except for the expression of CRMP2. Compared with Air+NS group, the total dendrite length, secondary dendritic length and interactions on 60 and 80 μm shells in the Sevo+NS group were decreased (P <0.01), whereas roscovitine partly reversed the changes above induced by sevoflurane (P <0.05). Compared with Air+NS group, the percentage of freezing time in the Sevo+NS group was decreased (P <0.01), whereas roscovitine partly reversed the changes induced by sevoflurane (P <0.05). No significant difference among groups in the open-field test was observed. CONCLUSION: Sevoflurane exposure disturbed dendritic development of neurons in PFC, learning and memory ability of neonatal rats, which may be mediated by Cdk5-CRMP pathway.     

Preparation and Identification of Polyclonal Antibodies against Porcine Cyclin Dependent Kinase 2

In order to research the biofunction of porcine cyclin dependent kinase 2 (pCDK2), this study prepared polyclonal antibodies against pCDK2.The recombinant prokaryotic expression plasmid pET28a-pCdk2 was constructed and transformed into BL21 (DE3), IPTG was used to induce the expression of recombinant pCDK2 (rpCDK2) which was then analyzed by SDS-PAGE and Western blotting.The expressed proteins were purified and emulsified with freund's adjuvant, the mixture was used to immunize the rabbits to prepare polyclonal antibodies against pCDK2.The immunocompetence of the antibody was identified by immunoperoxidase monolayer assay (IPMA), and the specificity was confirmed by Western blotting.The results showed that rpCDK2 was successfully expressed by prokaryotic expression system, and the expression products showed two forms:Solubility and inclusion body(IB), the molecular weight of the solute rpCDK2 was about 38 ku, however three different molecular weight forms (from 38 to 43 ku) of IB were observed.IPMA results showed that polyclonal antibodies against pCDK2 protein showed perfect activity which could recognize pCDK2 expressed in PK-15 cells and ST cells specifically.Western blotting analysis showed that four bands with different molecular weight forms (from 34 to 50 ku) were observed when the polyclonal antibodies against pCDK2 protein reacted with the total protein extracted from PK-15 and ST cells.In conclusion, the rpCDK2 protein was successfully expressed by prokaryotic expression system, the prepared rabbit polyclonal antibodies against pCDK2 protein showed wonderful activity and specificity, and the study provided basic material for the research of protein biofunction and related diseases.     

CONTRAST‐ENHANCED ULTRASONOGRAPHIC CHARACTERISTICS OF ADRENAL GLANDS IN DOGS WITH PITUITARY‐DEPENDENT HYPERADRENOCORTICISM

A noninvasive method for quantifying adrenal gland vascular patterns could be helpful for improving detection of adrenal gland disease in dogs. The purpose of this retrospective study was to compare the contrast‐enhanced ultrasound (CEUS) characteristics of adrenal glands in 18 dogs with pituitary‐dependent hyperadrenocorticism (PDH) vs. four clinically healthy dogs. Each dog received a bolus of the contrast agent (SonoVue®, 0.03 ml/kg of body weight) into the cephalic vein, immediately followed by a 5 ml saline flush. Dynamic contrast enhancement was analyzed using time–intensity curves in two regions of interest drawn manually in the caudal part of the adrenal cortex and medulla, respectively. In healthy dogs, contrast enhancement distribution was homogeneous and exhibited increased intensity from the medulla to the cortex. In the washout phase, there was a gradual and homogeneous decrease of enhancement of the adrenal gland. For all dogs with PDH, there was rapid, chaotic, and simultaneous contrast enhancement in both the medulla and cortex. Three distinct perfusion patterns were observed. Peak perfusion intensity was approximately twice as high (P < 0.05) in dogs with PDH compared with that of healthy dogs (28.90 ± 10.36 vs. 48.47 ± 15.28, respectively). In dogs with PDH, adrenal blood flow and blood volume values were approximately two‐ to fourfold (P < 0.05) greater than those of controls. Findings from the present study support the use of CEUS as a clinical tool for characterizing canine adrenal gland disease based on changes in vascular patterns.