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41.
A study was carried out in 1992 on the Val Joly reservoir and the rivers situated downstream: the River Helpe Majeure and the canalized Sambre into which it flows 40 km below the reservoir. Each year, blooms of blue-green algae occur in the reservoir. They are dominated by species such as Aphanizomenon flos-aquae (L.) Ralfs in 1991 or Pseudanabaena tenuis Koppe and Oscillatoria pseudogeminata G. Schmid in 1992. A typical fluvial composition of the phytoplankton was mostly restored above the confluence with the Sambre. Nevertheless, significant quantities of Oscillatoria and Pseudanabaena have been observed in the River Sambre, just below its confluence with the Helpe Majeure. The environmental conditions in the River Sambre do not allow Aphanizomenon to develop, but could favour Oscillatoria blooms. 相似文献
42.
Tetsuko Noguchi 《Protoplasma》1994,180(1-2):29-38
Summary The formation and the decomposition of vacuoles in a member of Xanthophyceae,Botryococcus braunii, were examined by light and electron microscopy. Particles around the nucleus were identified as vacuoles from their stainability with neutral red. These particles disappeared during cell division. They reacted positively in an activity test for acid phosphatase. Electron microscopy revealed the presence of spherical vacuoles around the nucleus. During cell division, these vacuoles seemed to be decomposed by the ER which surrounded the vacuoles. Soon after this decomposition, many immature multivesicular bodies (MVBs) appeared to develop from the trans-Golgi network (TGN) and were pinched off from the TGN. These immature MVBs took up small vesicles in them as they grew into the mature MVBs. Mature MVBs took up and digested the surrounding cytoplasm, fused with one another, and eventually became the vacuoles.Abbreviations MVB
multivesicular body
- TGN
trans-Golgi network 相似文献
43.
44.
Seiichi Ueda 《Mycoscience》1994,35(3):287-290
A new species ofCercophora, isolated from river sediment collected from Sakai River in Nagasaki Prefecture, Japan, is described and illustrated. It is distinguished from the other knwon species by the morphology of its ascomatal peridium and ascospores, and by itsChrysosporium-like anamorph. 相似文献
45.
Wagner U. Reinsberg J. Schmidt S. Mallmann P. Schmolling J. Schultes B. Richter H. Biersack H. J. Krebs D. 《Cell biochemistry and biophysics》1994,24(1-3):237-242
Antibodies can be processed by the B- and T-cell systems and may lead to a selective activation of the immune system. The
network structure of the immune system implicates the possibility of a selective immunization by the activation of idiotypic
cascades.
In a retrospective analysis, patients with advanced ovarian carcinoma, who had received MAb, against the cancer-associated
antigen CA125 for diagnostic purposes, were analyzed for the production of anti-idiotypic antibodies, survival rate, and immunological
effects. Furthermore, we started a prospective and randomized study for ovarian cancer patients, using a different antigen,
TAG72, for the induction of idiotypic cascades.
Our first results on 58 patients with advanced ovarian carcinomas showed that the induction of anti-idiotypic-antibodies against
OC125 mimicking the TAA Class III CA125 leads to a prolongation of the survival rate, and, in extended stages, to an induction
of antitumoral immunity, and that the induction of idiotypic cascades is also possible for different antigens like TAG72.
Summarizing the activation of idio-typic network cascades seems to be a very effective way of intervention in the immune system
of patients with advanced stages of ovarian carcinoma. A prospective study of the adjuvant approach seems to be necessary. 相似文献
46.
Lech Kufel 《Hydrobiologia》1993,251(1-3):269-274
Sedimentation at the Krutynia River inflow to Lake Kujno was closely related to hydrological regime. The highest sedimentation rates, recorded in spring, decreased during summer by two orders of magnitude. Granulometric segregation of settling seston along the inflow zone was related to differentiation of phoshorus content. Smaller particles were richer in P, producing a gradient of increasing P concentrations in the settling material. A substantial loss of P from polyphosphate and various organic fractions was found after settlement of river suspensoids. Mechanisms of P losses are discussed and possibilities of P retention within the inflow zone are considered. 相似文献
47.
Migratory behaviour and growth of hatchery-reared post-smolt Atlantic salmon Salmo salar 总被引:1,自引:0,他引:1
Individually lagged, 1+ and 2+ hatchery-reared smolts of Atlantic salmon were released in spring and early summer at the mouth of the R. Imsa, south-western Norway. The post-smolts moved mainly northwards in the sea with the coastal current. The estimated mean migratory speed (± s.d. ) of those captured in the sea along the Norwegian coast was 7.45 (± 6.26) km day −1 ; in the fjords it was 1.63 (± 2.33) km day−2 . Many of the post-smohs ascended rivers the same year as released; 37.3% of the total number recaptured were caught in R. Imsa, upstream from the site of release, and 5.8% were caught in other rivers throughout middle and southern parts of Norway. The fish recaptured in rivers was probably sexually mature and entered rivers to spawn. Mean specific growth rate for post-smolts caught in the sea was higher than for those caught in R. Imsa (P <0.001) but not for those caught in other rivers (P> 0.05). Post-smolts ascending R. Imsa were smaller at release than those ascending other rivers. However, there was no size difference at release between post-smolts captured in the sea and those recaptured in rivers other than the R. Imsa. 相似文献
48.
49.
Summary This study was to determine if feline immunodeficiency virus (FIV)-infected and uninfected Crandall feline kidney (CRFK) cells exhibited a low temperature (16°C) block in membrane trafficking between transitional endoplasmic reticulum and Golgi apparatus represented by intermediate compartment formation. Cells were cultured at different temperatures and membrane changes involving the Golgi apparatus and Golgi apparatus-associated membrane structures were monitored by electron microscopy and quantitated. With 30 min of incubation, membranes of the Golgi apparatus stack increased in amount at temperatures of 16°C and below compared to temperatures above 18°C. The increase was greatest along the major polarity axis as evidenced by an increased stack height. Neither the number of cisternae per stack nor the average stack diameter (width) was affected by temperature. The response was maximal between 15 and 30 min of low temperature treatment of the cells. Results with cells infected and uninfected with feline immunodeficiency virus were similar. The increase in stack height was due primarily to an increase of membranes at the cis face (cis Golgi apparatus network). At 18°C, membranes of the trans Golgi apparatus network accumulated suggesting that import from the cis Golgi network could proceed at this temperature, whereas exit from the trans Golgi network was still at least partially blocked. Also increased at 16°C and below were numbers of transition vesicles in the space between the Golgi apparatus and the transitional endoplasmic reticulum associated with the cis Golgi apparatus face. The results suggested interruption of the orderly flux of membranes into the Golgi apparatus at 16°C and below. Moreover, the block appeared to be reversible. Upon transfer from 16°C to 37°C, there was a time-dependent decrease in the accumulations of cis compartment membrane accompanied by a corresponding equivalent increase in the membranes of the trans Golgi apparatus compartment. 相似文献
50.
【目的】解析土壤微生物在植物根际的组配机制对于认识和维护农田生态系统的稳定性至关重要。【方法】通过Illumina高通量测序和生物信息学分析方法明确了我国主要种植烟草生态区烤烟根际土壤细菌群落与土壤理化性质的互作关系。【结果】烤烟根际细菌类群主要为放线菌纲(Actinobacteria)、α-变形菌纲(Alphaproteobacteria)、γ-变形菌纲(Gammaproteobacteria)和嗜热油菌纲(Thermoleophilia)。细菌群落组成按生态区聚类,且样本空间距离和细菌群落相似度显著负相关。共现性网络分析表明,烤烟根际细菌群落间协同作用大于拮抗作用,武陵秦巴生态区、黄淮平原生态区、南岭丘陵生态区和沂蒙丘陵生态区细菌群落高度模块化,小单胞菌属(Micromonospora)为南岭丘陵生态区和黄淮生态区细菌共现性网络的网络中心,Bryobacter和气单胞菌属(Arenimonas)为南岭丘陵生态区细菌网络的模块核心,其菌群特性而非相对丰度决定了其在稳定细菌网络中的重要作用。冗余分析结果证实pH、有效铁、交换性镁和有效锰能显著影响烤烟根际细菌群落结构。【结论】烤烟根际细... 相似文献