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.     

两种纯化苏云金杆菌HD-73毒素蛋白方法的比较研究

以苏云金杆菌HD 73伴胞晶体为活性蛋白,经胰蛋白酶酶解后分别用阴离子交换柱分离纯化法和等电点纯化法进行纯化,纯化后得到的样品进行SDS-PAGE分析,结果表明,两种分离纯化都获得67kDa的毒素蛋白,但是离子交换柱纯化法样品消耗量大,得率低;而等电点沉淀法样品消耗少,得率高。     

Responses of scallop biodeposits to bioturbation by a deposit‐feeder Apostichopus japonicus (Echinodermata: Holothuroidea): does the holothurian density matter?

The deposit‐feeding holothurians can reduce the negative impact of bivalve farming by feeding and reworking bivalve wastes (biodeposits) in the context of co‐culture. To test effects of the bioturbation by holothurians of different densities on bivalve wastes, a stocking density regime of the sea cucumber Apostichopus japonicus (35.4 ± 1.2 g, mean ± SE) was set at 0.0, 6.6, 13.2 ind m^?2, and responses of the biotic parameters including chlorophyll a concentration (Chl. a), bacterial biomass and the abiotic ones as oxidation‐reduction potential (ORP), organic matter (OM), organic carbon (OC), total nitrogen (TN) and organic phosphorus (OP) in biodeposits discharged by Japanese scallop Patinopecten yessoensis were investigated. Results showed that A. japonicus grew in a density‐dependent manner, and the density‐dependent effect on both biotic and abiotic parameters in biodeposits were also observed. Apostichopus japonicus stimulated a transfer process from reduction to weak reduction state of the biodeposits with a trend of higher density holothurians stimulating the process more. Furthermore, A. japonicus significantly controlled the bacterial abundance and Chl. a, as well as reducing the contents of OM, OC, TN and OP in the biodeposits. Yet, the response of abiotic parameters delayed rather than that of biotic parameters, underling the biotic parameters could be more sensitive to bioturbation than the abiotic ones. Our study suggests that the bioturbation of A. japonicus plays an important role in retarding organic waste accumulation and cleansing nutrients in bivalve farming wastes under co‐culture condition and the bioremediation capacity may be closely dependent on its stocking density in practice.     

A collective navigation hypothesis for homeward migration in anadromous salmonids

Anadromous salmon (genera Oncorhynchus and Salmo) spend much of their lives feeding in productive northern oceans and then return home to natal sites for reproduction with remarkable accuracy. The mechanisms used for navigation by individuals during migrations are thought to include geomagnetic, celestial and olfactory cues, but rarely are social interactions between individuals considered. Mounting evidence from other taxa indicates that individuals in larger groups can better sense and respond to environmental cues, thus potentially increasing their ability to navigate. Here, we propose that salmon might similarly benefit from collective navigation on their homeward journey. To explore this, we compiled data from multiple studies and found strong evidence that rates of successful homing increase with population abundance, consistent with collective navigation. We then discuss how collective navigation could benefit salmon during each stage of their seaward and homeward migrations, and complement this with a review of salmon sociality. Next, we analyse historic high‐seas catch records and provide new insight into schooling structure of salmon in the marine environment. We argue that collective navigation likely represents a presently under‐appreciated mechanism enhancing the navigational ability of salmon as well as other migratory species, and outline critical tests of our hypothesis.     

基于冠层反射率模型的作物参数多阶段反演方法研究进展

利用遥感手段,基于冠层反射率(canopy reflectance,CR)模型反演农作物参数具有经济、高效、普适性好的特点,是智慧农业快速、精确监测区域尺度农情信息的理想方法。然而,CR模型反演过程受"病态反演"问题影响。针对此,前人提出了多阶段目标决策(multi-stage,sample-direction dependent,target-decisions,MSDT)法和面向对象(object-based)反演法。分别依据CR模型参数的敏感性和不确定性,以及作物参数的空间分布特征,将反演过程划分为若干阶段,每阶段只反演部分参数,前阶段反演结果作为后阶段反演的先验知识,以此减少CR模型参数优化的不确定性,改善"病态反演"问题。该文系统总结了MSDT法与面向对象反演法,将其归纳为统一的"多阶段反演"方法,并提出概念模型。基于此,总结、讨论了多阶段反演中如下三方面共性问题,试分析可能的解决途径:1)多阶段反演决策还需要广泛比较、科学论证与改进,以确保其合理性和有效性;未来研究中,应将MSDT法与面向对象反演方法有机结合,在统一的多阶段反演技术框架下,制定更加合理的反演决策方法。2)CR模型的参数化精度可能影响多阶段反演;未来应尝试利用"天空地一体化"遥感技术和尺度转换方法获取先验知识,提高CR模型参数化精度。3)多阶段反演过程中,反演误差逐级传递;未来研究中,一方面应尝试识别并纠正前阶段反演中的误差,另一方面应合理利用前阶段反演结果,避免前阶段反演误差影响后阶段的反演。