967 resultados para NAD(P)H OXIDASE


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TOPIC 1: In terms of seasonal scale, temperature effect dominates the annual change of steric height in the open ocean whereas salinity effect controls it along the continental shelf. Large portion of the annual change of height relative to the 1000-db surface is contained in the upper 100m layer. However, in interannual scale large anomalies of steric height in the open ocean, are more often than not, caused by halosteric rather than thermosteric effect. At least in the open ocean the heights are almost totally determined by the behavior of deep water. Their interannual variability appears to be related to the cumulative effect of Eckman pumping. TOPIC 2: There is a "trend" that over the past 28 years the water at Station P has warmed. Least-square analysis indicates that this warming may be significant but shortening of the time-series data by approximately 10 years fails to show that this is the case. These "trends" have to be interpreted with care. The warming may be "apparent" in that it is not indicated clearly in the deep isopynal surfaces which, during the above period, have deepened. Thus warming at the isobaric surfaces may be the effect of the downward migration of the isopynal surfaces.

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Twenty-seven years (1956-1983) of oceanographic data collected at Ocean Station P (50°N/145°W), as well as supplementary data obtained in its neighborhood, have been examined for trends and interannual variability in the northeast Pacific Ocean. There is evidence that the water is warming and freshening and that the isopycnal surfaces are deepening. Trends in oxyty are mostly not significant. The most common periods for the interannual variability appear to be 2 1/2 and 6-7 years. The vertical movement of water accounts for one half of the changes in temperature and salinity and 30% of those in oxyty. Other factors, such as a shift of water masses, may also be important.

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为了重建东亚季风区域2.5MaB.P.前后植被和气候变化的历史,更好地了解低纬度地区植被变化及其对全球变化的响应,本研究选择了南海南部ODP1143站深海沉积物中的孢粉样品进行研究。通过高分辨率(7ka)的孢粉样品的分析研究,建立起3.0~2.0MaB.P.时段南海深海沉积孢粉组合序列,系统建立了这一时段植被演替序列。在此基础上,重点研究了2.5MaB.P.前后气候变化在南海周边地区植被演替中的响应,为探索和揭示东亚古季风及古环境演变提供了孢粉学依据。 ODP 1143站位于南沙海区,北纬9º22´,东经113º17´,深海柱状样采于水深2772m的大陆坡。本研究以生物地层学和氧同位素年代学为依据建立了年龄框架,对1143站135~95m(3.0~2.6 Ma B. P.)深海沉积中的孢粉样品进行了分析,建立了3.0~2.0MaB.P.时段南海深海沉积孢粉组合序列。孢粉样品处理方法主要是用盐酸去掉钙质和氢氟酸浸泡溶解硅质后,再用筛子将样品在超声波发生器中震荡过滤。孢粉的鉴定和统计在光学透视显微镜下完成。研究结果表明: 1、孢粉谱的主要特征是沉积率变化显著。与3.0~2.6 Ma B. P. 相比,2.6~2.0 Ma B. P.各类型花粉及孢子沉积率均有显著提高。该结果表明2.6 Ma B. P.南海海平面有显著下降,可与北半球冰盖形成、东亚季风增强相对应。 2、2.6 Ma B. P.以来,各类型孢粉沉积率变化与深海氧同位素分期相对应,代表了多次冰期-间冰期旋回。该结果表明南海海平面曾有多次上升和下降。 3、频谱分析结果表明,3.0~2.0 Ma B. P.存在0.1 Ma(偏心率)和46.9ka(斜率)的周期。

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This study reports new information about searobin (Prionotus spp.) early life history from samples collected with a Tucker trawl (for planktonic stages) and a beam trawl (for newly settled fish) from the coastal waters of New Jersey. Northern searobin, Prionotus carolinus, were much more numerous than striped searobin, P. evolans, often by an order of magnitude. Larval Prionotus were collected during the period July–October and their densities peaked during September. For both species, notochord flexion was complete at 6–7 mm standard length (SL) and individuals settled at 8–9 mm SL. Flexion occurred as early as 13 days after hatching and settlement occurred as late as 25 days after hatching, according to ages estimated from sagittal microincrements. Both species settled directly in continental shelf habitats without evidence of delayed metamorphosis. Spawning, larval dispersal, or settlement may have occurred within certain estuaries, particularly for P. evolans; thus collections from shelf areas alone do not permit estimates of total larval production or settlement rates. Reproductive seasonality of P. carolinus and P. evolans may vary with respect to latitude and coastal depth. In this study, hatching dates and sizes of age-0 P. carolinus varied with respect to depth or distance from the New Jersey shore. Older and larger age-0 individuals were found in deeper waters. These variations in searobin age and size appear to be the combined result of intraspecific variations in searobin reproductive seasonality and the limited capability of searobin eggs and larvae to disperse.

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用生物和非生物因子来进行采后病害的防治,是一个非常有效的方法。诱导抗性作为控制果蔬采后病害的生物技术,已成为该领域的一个研究热点。然而诱导抗性的机制非常复杂,涉及到寄主、病原菌、激发子之间的相互作用关系。本研究主要利用酵母拮抗菌Pichia membranefaciens和SA处理果实,观察其抗性诱导表达和对采后青霉病菌(Penicillium expansum)的抑制作用,并从蛋白质组学水平上对诱导抗性的机理进行了分析。研究结果表明: 1、酵母拮抗菌P. membranefaciens (5 × 107 cells·ml-1)和SA(0.5 mM)处理采后甜樱桃果实,能够明显地降低病害的发病率和病斑直径。酵母菌和SA处理影响到了果实抗氧化酶的活性,同时还改变了POD同工酶谱和甜樱桃果实的总蛋白含量,并诱导了新的蛋白质条带产生。用光学显微镜和扫描电子显微镜技术观察发现,在in vitro条件下P. membranefaciens能够紧密地结合与病原菌的菌丝,而在in vivo条件下这种结合较为松散。 2、借鉴其它模式植物的方法,我们建立了一整套适用于多汁类植物材料的蛋白质组学研究方法。对于芒果,桃,甜樱桃、苹果以及冬枣等果实,都取得了重复性非常好的2-D图谱。我们应用该技术进一步研究了P. membranefaciens (1 × 108 cells·ml-1)以及SA (0.5 mM)处理对桃果实蛋白质组的诱导影响。结果显示,两种激发子处理都能够诱导桃果实产生抗性,从而减轻青霉病引起的腐烂。在诱导处理1 d以后,酵母拮抗菌和SA分别诱导22和16个蛋白的差异表达。质谱鉴定的蛋白属于6大类:代谢,防御反应,转录,能量途径以及细胞结构。有6个蛋白受到两种激发子的共同调控。其中,4种蛋白(包括glutathione peroxidase, polyphenol oxidase precursor, catalase和methionine sulfoxide reductase) 属于抗氧化蛋白,涉及到活性氧代谢。另2个蛋白(Major allergen Pru av 1和peroxidase)是病程相关蛋白,直接参与植物的防御反应。同时一些磷酸化酶和转录因子也受到两种激发子的调节从而参与果实的抗病反应。酶学测定和Northern杂交的结果表明,拮抗菌与SA处理均能影响过氧化氢酶活性及其基因的表达。 3、采前用较高浓度SA (2 mM) 短时间(10s)处理不同成熟期的甜樱桃果实,能够明显降低果实青霉病的病斑直径,并能减轻较低成熟度果实的发病率。在没有接菌的情况下,SA诱导了33个差异表达的蛋白,其中用质谱鉴定出了26个。而在接种病原菌的情况下,SA诱导了19个差异表达的蛋白,并鉴定出了其中的12个。这些蛋白分别涉及到代谢、防御反应、转录、能量途径、信号转导等过程。在没有接种病原菌的情况下,SA处理诱导了Putative DnaJ heat shock protein, PR1-like protein, Peroxidase, Major allergen Pru av 1 (Pru a 1)和Catalase等与抗病有关的蛋白。而在接种病原菌的情况下,诱导了PR1-like protein, Peroxidase和Catalase蛋白的差异表达。通过酶活性测定以及对细胞学定位的研究,我们发现在没有接种病原菌的情况下,POD的活性受到SA的诱导。但是在接种病原菌以后,诱导效果不明显。