Duration of maternally derived antibodies against equine influenza in newborn foals

Serum antibody concentrations against influenza A-equi-1 virus and A-equi-2 virus were measured in a group of 18 foals from birth to 4 months of age. More than 50% of the foals were seronegative to A-equi-1 virus infection by 4 weeks of age, with titers of less than or equal to 1:16. For A-equi-2 virus, more than 50% of the foals were seronegative by 2 weeks of age, with titers of less than or equal to 1:8. Passively derived antibodies against influenza A-equi-1 virus and A-equi-2 virus in foals obtained from recently vaccinated mares and from mares not vaccinated within 6 months before foaling were low in titer. The duration of passively derived antibodies was also short-lived.     

Ultrastructure of goat testes: tubulobulbar complexes between spermatids and Sertoli cells

The fine structure of tubulobulbar complex (TBC) of goat seminiferous epithelium was studied using testicular samples fixed by perfusion. During the maturation phase of the spermatid, the TBC appeared on the periphery of the head before spermiation, dorsal and ventral parts of the head, both sides of the acrosome and on the postnuclear sheath region. At an early stage of the development of the TBC, a partial loss of smooth endoplasmic reticulum in the ectoplasmic specialization of a neighboring Sertoli cell was observed; filament bundles disappeared and a small fragmented smooth endoplasmic reticulum was left. Subsequently, a spermatid vesicle (coated vesicle) expanded to be in contact with the Sertoli cytoplasm by a small channel. These tubular projections extended to form a bulbous balloon-like structure forming sometimes a bi-balloon appearance, until torn off from the spermatid into the Sertoli cytoplasm and probably digested by the Sertoli cell. The significance of this structural development was morphologically discussed.     

Poxvirus infection in Nile crocodiles (Crocodylus niloticus)

An outbreak was encountered of numerous yellowish cutaneous nodules in one- to two-year-old farmed Nile crocodiles (Crocodylus niloticus) in Kasaba Bay Crocodile Farm at Lake Tanganyika in Zambia during 1988. Out of 4000 crocodiles of different age groups, 300 yearlings were affected and 82 of those affected died. The lesions were prominent on the head, especially around the eyelids, the nostrils, both sides of the mouth, ventral neck, ventral pale belly, limbs and the root of the tail. Histologically, the epidermal lesions revealed large focal areas of marked acanthosis accompanied by hyperkeratosis and parakeratosis. In the prickle cells, there were multiple small neutrophilic granular inclusions and large eosinophilic homogeneous cytoplasmic inclusions. Electron microscopically, there were numerous poxvirus particles and matrices in the cytoplasm of many prickle cells. Dark blue homogeneous cytoplasmic inclusions in toluidine blue sections consisted of an electron opaque matrix with mature viral particles (160 x 200 x 230 nm). Furthermore, there were clumps of granular matrix containing immature viral particles (200 x 399 nm) in the cytoplasm. Various features of viral developing processes were observed.     

Inoculum levels ofVerticillium dahliae in the soils of the hot semi-arid negev region of Israel

In the Negev area,Verticillium dahliae Kleb. produces 50 times more microsclerotia (MS) on potato plants harvested in the winter than on those harvested in the summer. Number and distribution of viable fungal units, subsequent to incorporation of infected potato plants and during a sequence of non-susceptible hosts, were estimated in February of the following years by counting fungal units in four sublayers: 0–10, 10–20, 20–30 and 30–40 cm. Inoculum density ofV. dahliae was the highest in the top layer, decreasing to the deepest sublayer. Reduction of population density of viableV. dahliae units was less in the field than in the laboratory. No viable units were detected after 5 years of storage in the laboratory, whereas 4% of the original population remained viable after 7 years of crop rotation. Although crop rotation did not control the fungus completely, it did reduce inoculum density markedly.     

新图书馆运动

新图书馆运动实现了中国图书馆从藏书楼到近代图书馆的转变,促进了图书馆事业的发展,成立了图书馆协会,形成了图书馆学教育的规模,产生了第一代图书馆学人。     

Change of reactive oxygen species production in co-culture model of rat astrocytes and motor neurons VSC 4.1

AIM: To explore the mutual effect of co-culture of wild-type astrocytes (ASC) and motor neurons VSC4.1 (VSC) on the respective ability to produce reactive oxygen species (ROS). METHODS: The inhibition rates of cell growth in ASC and VSC in co-culture or independent culture was detected after exposed to excitatory stimulus by MTT method. Real-time observation of ROS production by ASC and VSC labeled with Hoechst 33342 was detected by confocal microscopy under the conditions of co-culture or independent culture. RESULTS: Higher concentration of glutamate induced a higher inhibition rate in mixed cell growth than that in ASC alone, while lower concentration of glutamate induced a higher inhibition rate in mixed cell growth than that in VSC only. Real-time observation by confocal microscopy showed that ROS production by VSC under the condition of co-culture, which showed a notable increase at 15 min, was significant less than that in independent culture, which peaked at 5 min and was gradually decreased. ROS production by ASC in co-culture began to increase significantly at 10 min. CONCLUSION: Compared to independent culture, ASC reduces the resting ROS production by co-cultured with VSC, while ASC prolongs the duration of ROS production by VSC after exposed to excitatory stimulus.     

羽叶决明代木栽培鸡腿菇的物质转化

研究羽叶决明(Chamaecrasta nictitans)代木栽培鸡腿菇(Coprinus ovatus)对其绝对生物学效率、基物失重、呼吸消耗及木质纤维素转化的影响.结果表明,羽叶决明牧草替代60%木屑(A60)栽培鸡腿菇的绝对生物学效率最高,均为10.77%.覆土前和采收后的基物失重和呼吸消耗都以A0(CK)为最高,分别为11.47%、11.47%和31.75%、25.55%,其木质素转化率也最高,为79.21%;纤维素转化率以A100(羽叶决明牧草替代100%木屑)为最高,达50.93%;半纤维素转化率以A40(羽叶决明牧草替代40%木屑)为最高,为49.74%.回归分析结果表明,绝对生物学效率和半纤维素转化率与替代比例呈抛物线相关,而基物失重、呼吸消耗及木质素、纤维素转化率与替代比例呈线性相关.     

我校图书馆读者工作的实践

本文讨论了高校图书馆如何在新的环境下优化馆藏、提高馆藏利用率，包括电子文献及网络资源的利用等。