168 resultados para CV-6690


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The effects of temperature and food availability on the life history strategy of the planktonic copepod Calanus sinicus in the southern Yellow Sea in summer were studied in this paper. The fifth copepodite stage (CV) dominates the population in the central part of the southern Yellow Sea, where the Yellow Sea Cold Water Mass (YSCWM) occurs below the thermocline. Incubation experiments were conducted on CV C. sinicus caught from the YSCWM to examine the effects of temperature and food availability. Temperature at the surface (27degreesC) is lethal to CVs regardless of food availability. At the temperature in the middle of the thermocline (18degreesC), survival time of the specimens depends on food availability, being similar to20 days in treatments without extra food supply. At the temperature in the YSCWM (9degreesC), most animals survive at the end of 27 day incubation even in treatments without food supply. Developmental rate of CVs at 9degreesC without extra food supply is extremely low. The increase of either temperature or food supply promotes the developmental rate of CVs. According to these results, the surface layers with high temperature and low food abundance are detrimental for the survival and reproduction of C. sinicus. Low temperature and low food availability in the YSCWM help CV to maintain a much lower developmental rate and higher survival rate. The ecological trait of C. sinicus in the southern Yellow Sea in summer cannot be sufficiently explained solely by the effects of temperature.

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Ecological and physiological features of the planktonic copepod Calanus sinicus in the southern Yellow Sea in summer were studied to reveal its life history strategy. From the coastal shallow waters to the central part of the southern Yellow Sea, a shift of the stage composition occurs from being dominated by the egg-nauplius stage to being dominated by the fifth copepodite (CV) stage. Most CVs reside in the Yellow Sea Cold Water Mass (YSCWM), where both temperature and food abundance are low. CVs in the YSCWM have longer body lengths, heavier body weights and higher carbon contents than those outside the YSCWM. Onboard incubations show that the development of CVs in the YSCWM is suspended. Energy conservation, development suspension and lack of diel vertical migration (DVM) behavior suggest a diapause status for the CVs in the YSCWM, although vertical distribution patterns indicate the CV individuals are not fully synchronous in physiology and development. This adaptive oversummering strategy would help C. sinicus to live through the warm and food-limited summer in the central part of the southern Yellow Sea; both low temperature and low food supply are necessary for CV to maintain the resting state in the YSCWM. Calanus sinicus exhibits different life history strategies in different regions of the southern Yellow Sea in summer.

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The distribution, feeding and oxygen consumption of Calanus sinicus were studied in August 2001 on a transect across Yellow Sea Cold Bottom Waters (YSCBW) and two additional transects nearby. The distribution of C. sinicus adults and copepodites stage CV appeared to be well correlated with water temperature. They tended to concentrate in the YSCBW (>10,000 ind. m(-2)) to avoid high surface temperature. Gut pigment contents varied from 0.44 to 2.53 ng chlorophyll a equivalents (chl a equiv.) ind.(-1) for adults, and from 0.24 to 2.24 ng chl a equiv. ind.(-1) for CV copepodites. We found no relationship between gut pigment contents and the ambient chl a concentrations. Although the gut evacuation rate constants are consistent with those measured for other copepods, their low gut pigment contents meant an estimated daily herbivorous ingestion of <3% of body carbon in the YSCBW and <10% outside the YSCBW. However, based on estimates of clearance rates, C. sinicus feeds actively whether in the YSCBW or not, so the low ingestion rates probably reflect shortage of food. Oxygen consumption rates of C. sinicus ranged from 0.21 to 0.84 mul O-2 ind.(-1) h(-1), with high rates often associated with high temperature. From the oxygen consumption rates, daily loss of body carbon was estimated to be 4.0-13.7%, which exceeds our estimates of their carbon ingestion rates. C. sinicus was probably not in diapause, either within or outside the YSCBW, but this cold-water layer provides C. sinicus with a refuge to live through the hot, low-food summer.

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A series of experiments were conducted to identify the factors that affected the growth and survival of the settling flounder larvae Paralichthys olivaceus. Settling larvae 24 days after hatching (DAH) were reared in 10-l experimental tanks up to 40 DAH, and two of the following factors were changed as controlled factors in each experiment: light regime (24L:0D or 12L:12D), prey density (1500, 3000, or 5000 Artemia l(-1)), shelter (sand or no sand) and stocking density (5, 10, or 15 fish l(-1)). Early settling larvae (24-35 DAH) experienced little mortality (less than 10% of the overall mortality) that was not significantly affected by above factors. In contrast, late settling larvae (36-40 DAH) suffered high cannibalistic mortality which was significantly influenced by each of the above factors. Larvae experienced significantly lower mortality at 10 fish l(-1) level than at other densities. Larvae at 15 fish l(-1) level had higher mortality than at 5 fish l(-1) when all other factors were identical. Larvae at 3000 and 5000 Artemia l(-1) treatments survived significantly better than at 1500 Artemia l(-1), but no significant differences in larval mortality were found between the two higher densities. Larvae suffered higher mortality at low prey density or at the absence of sand when they were exposed to longer photoperiod. Low stocking density significantly improved the growth of the settling larvae. The average daily instantaneous growth rate (G) at 5 and 15 fish l(-1) treatments were 0.050 and 0.034, with the coefficient of variation (CV) in final length at 16.4 and 23.5, respectively. Daily instantaneous growth rate increased significantly from 0.033 in the 1500 Artemia l(-1) to 0.041 and 0.045 in the 3000 and 5000 Artennia l(-1), respectively, but no significant difference in larval growth existed between the two higher prey densities. These findings suggested that the optimal prey density for growth and survival of the settling flounder larvae at a stocking density of 5 - 15 fish l(-1) was around 3000 Artemia l(-1) . Larvae that were exposed to 24L showed 20% increase in growth ( G = 0.046, CV = 18.7) than those exposed to 12L ( G = 0.037, CV = 20.5). Longer exposure to light significantly improved larval growth, provided sufficient food was available. Sand substrate did not show significant effects on larval growth, possibly because the larvae spent most of the time swimming or feeding in the water column during this stage. (C) 2003 Elsevier Science B.V. All rights reserved.

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The effects of the timing of first feeding (0, 1 and 2 days after yolk exhaustion) and starvation on the point-of-no-return (PNR), survival and growth of laboratory-reared rock bream larvae were studied under controlled conditions. Larvae began to feed exogenously at 3 days after hatching (dah) and reached PNR on 54 h after yolk exhaustion at 22 +/- 1.5 degrees C. Larvae growth was significantly affected by the time of first exogenous feeding. The growth of 0 day delayed first feeding larvae was obviously faster than those of the other delayed first feeding larvae (P<0.05) whether at 7 dab (SL=3.40 mm, SGR=5.7, CV=4.0) or at 15 dah (SL=4.85 mm, SGR=6.1, CV=8.2) with a more uniform size distribution. Survival of 0 day delayed first feeding larvae and I day delayed first feeding larvae was 13% and 8% at the end of experiment, respectively, while no larvae survived up to 7 dah for 2 days delayed first feeding larvae and unfed larvae. Food resulted in a progressive deterioration of the larval digestive system and atrophy of skeletal muscle fibre. The ratios of head length to SL (standard length), body height to SL and eye diameter to SL were the most sensitive morphometric indices to detect the effects of fasting on larval condition. Present results showed that the combination of morphological and morphometric variables could be used to evaluate the nutritional condition of rock bream larvae. In order to avoid the potential mortality and gain better development, survival and growth in industrial production, the rock bream larvae must establish successful first feeding within 2 days after yolk exhaustion. (C) 2008 Elsevier B.V. All rights reserved.

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The spatial distribution of stage-specific abundance and reproduction of the copepod Paracalanus parvus were studied from October 2005 to September 2006 in the Jiaozhou Bay. This copepod occurred continuously in this bay throughout the year. The species reached the lowest abundance in April and peaked in June. From October to December, distribution center mainly occurred in offshore water and at the mouth of the bay. In winter, early copepodites and adults gradually decreased and till February, most of the population was only comprised of CIV-CV stages. Overwintering copepodites matured in March and males tended to mature before female. From May to September, each stage occurred in the population and gradually reached high abundance. Temperature and chlorophyll a (Chl-a) concentration in the three stations can't clearly explain the seasonal variation in stage-specific abundance, so we surmised the important effect of the Yellow Sea. Egg production rate (EPR) reached its lowest in winter and peaked in June at 60.8 eggs female(-1) day(-1) in nearshore water. In the warming period, EPR in nearshore water was statistically higher and EPR > 10 eggs female(-1) day(-1) lasted longer than that in offshore water, showing the importance of nearshore water for recruitment of R parvus. Our study showed that EPR was positively related to temperature and total chlorophyll a in offshore water and mouth of the bay. In nearshore water, the relationships between EPR and temperature and Chl-a in three size fractions were not the same as those in offshore water, suggesting complicated ecosystem in such a eutrophic area in warming period. (C) 2008 Elsevier Ltd. All rights reserved.

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青藏高原生态系统对全球气候变化较为敏感,系统的行为能更早地预兆全球变化,进而影响到邻近地区乃至全球气候.因此,青藏高原生态系统的行为研究具有特殊重要性.利用中国科学院海北高寒草甸生态系统定位站多年来积累观测的长时间序列数据,运用生态系统稳定性直接分析方法,定量分析高寒草甸生态系统的稳定性及其对环境变化的灵敏度.结果表明,高寒草甸生态系统的主要气候因子如年降水、年均气温都比较稳定(CV值分别为16.55%和28.82%),而年度地上净初级生产量较降水和气温更为稳定(CV值为13.18%).净初级生产量关于降水和气温的灵敏度或弹性分别为E=0.0782和0.1113,即净初级生产量对降水和气温的波动均不敏感,也说明高寒草甸生态系统具有较高的稳定性.通过高寒草甸生态系统与世界其他地区5个草地生态系统的稳定性度量值横向比较,也显示出该系统的稳定性程度较高.结构相对比较简单的高寒草甸生态系统有较高的稳定性,说明群落稳定性虽然与物种多样性和群落复杂性有关,但未必成正比关系.还有其他一些因素与生态系统稳定性密切相关,如生物群落的外部环境稳定程度等.高寒草甸生态系统的主要气候因子(年降水和年均气温)以34年的主周期随机低频振荡,在其作用下生态系统的行为呈现同主周期、振幅比较稳定的随机波动.高寒草甸生态系统的较高稳定性,是较稳定的环境和系统适应环境的进化演替结果.

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A pre-column derivatization method for the sensitive determination of amines using the labeling reagent 1,2-benzo-3,4-dihydrocarbazole-9-isopropyl chloroformate (BCIC-Cl) followed by high-performance liquid chromatography with fluorescence detection has been developed. Identification of derivatives is carried out by high performance liquid chromatography/atmospheric pressure chemical ionization (LC-APCl-MS-MS). The chromophore of 2-(9-carbazole)-ethyl chloroformate (CEOC) reagent is replaced by 1,2-benzo-3,4-dihydrocarbazole-9-isopropyl functional group, which results in a sensitive fluorescence derivatizing reagent BCIC-Cl. BCIC-Cl can easily and quickly label amines. Derivatives are stable enough to be efficiently analyzed by high-performance liquid chromatography and show an intense protonated molecular ion corresponding m/z [MH](+) under APCl in positive-ion mode. The collision-induced dissociation of protonated molecular ion formed a product at m/z 260 corresponding to the cleavage of CH2-OCO bond. Studies on derivatization demonstrate excellent derivative yields over the pH 9.0-10.0. Maximal yields close to 100% are observed with a 3 to 4-fold molar reagent excess. In addition, the detection responses for BCIC derivatives are compared with those obtained using CEOC and FMOC as derivatization reagents. The ratios of l(BCIC)/l(CEOC) and l(BCIC)/l(FMOC) are, respectively, 1.23-3.14 and 1.25-3.08 for fluorescent (FL) responses (here, l is relative fluorescence intensity). Separation of the derivatized amines had been optimized on reversed-phase Eclipse XDB-C-8 column. Detection limits are calculated from 1.0 pmol injection, at a signal-to-noise ratio of 3, are 10.6-37.8 fmol. The mean interday accuracy ranges from 94 to 105% for fluorescence detection with the largest mean %CV < 7.5. The mean interday precision for all standards is < 6.0% of the expected concentration. Excellent linear responses are observed with coefficients of > 0.9997.

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The meadow ecosystem on the Qinghai-Tibetan Plateau is considered to be sensitive to climate change. An understanding of the alpine meadow ecosystem is therefore important for predicting the response of ecosystems to climate change. In this study, we use the coefficients of variation (Cv) and stability (E) obtained from the Haibei Alpine Meadow Ecosystem Research Station to characterize the ecosystem stability. The results suggest that the net primary production of the alpine meadow ecosystem was more stable (Cv = 13.18%) than annual precipitation (Cv = 16.55%) and annual mean air temperature (Cv= 28.82%). The net primary production was insensitive to either the precipitation (E = 0.0782) or air temperature (E = 0.1113). In summary, the alpine meadow ecosystem on the Qinghai-Tibetan Plateau is much stable. Comparison of alpine meadow ecosystem stability with other five natural grassland ecosystems in Israel and southern African indicates that the alpine meadow ecosystem on the Qinghai-Tibetan Plateau is the most stable ecosystem. The alpine meadow ecosystem with relatively simple structure has high stability, which indicates that community stability is not only correlated with biodiversity and community complicity but also with environmental stability. An average oscillation cycles of 3-4 years existed in annual precipitation, annual mean air temperature, net primary production and the population size of consumers at the Haibei natural ecosystem. The high stability of the alpine meadow ecosystem may be resulting also from the adaptation of the ecosystem to the alpine environment.

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A pre-column derivatization method for the sensitive determination of amino acids and peptides using the tagging reagent 1,2-benzo-3,4dihydrocarbazole-9-ethyl chloroformate (BCEOC) followed by high-performance liquid chromatography with fluorescence detection has been developed. Identification of derivatives was carried out by liquid chromatography/electrospray ionization mass spectrometry (LC/ESI-MS/MS). The chromophore of 2-(9-carbazole)-ethyl chloroformate (CEOC) reagent was replaced by 1,2-benzo-3,4-dihydrocarbazole functional group, which resulted in a sensitive fluorescence derivatizing reagent BCEOC. BCEOC can easily and quickly label peptides and amino acids. Derivatives are stable enough to be efficiently analyzed by high-performance liquid chromatography. The derivatives showed an intense protonated molecular ion corresponding m/z (M + H)(+) under electrospray ionization (ESI) positive-ion mode with an exception being Tyr detected at negative mode. The collision-induced dissociation of protonated molecular ion formed a product at m/z 246.2 corresponding to the cleavage of C-O bond of BCEOC molecule. Studies on derivatization demonstrate excellent derivative yields over the pH 9.0-10.0. Maximal yields close to 100% are observed with a 3-4-fold molar reagent excess. Derivatives exhibit strong fluorescence and extracted detzvatization solution with n-hexane/ethyl acetate (10:1, v/v) allows for the direct injection with no significant interference from the major fluorescent reagent degradation by-products, such as 1,2-benzo-3,4-dihydrocarbazole-9-ethanol (BDC-OH) (a major by-product), mono- 1,2-benzo-3,4-dihydrocarbazole-9-ethyl carbonate (BCEOC-OH) and bis-(1,2-benzo-3,4-dihydrocarbazole-9-ethyl) carbonate (BCEOC)(2). In addition, the detection responses for BCEOC derivatives are compared to those obtained with previously synthesized 2-(9-carbazole)-ethyl chloroformate (CEOC) in our laboratory. The ratios AC(BCEOC)/AC(CEOC) = 2.05-6.51 for fluorescence responses are observed (here, AC is relative fluorescence response). Separation of the derivatized peptides and amino acids had been optimized on Hypersil BDS C-18 column. Detection limits were calculated from 1.0 pmol injection at a signal-to-noise ratio of 3, and were 6.3 (Lys)-177.6 (His) fmol. The mean interday accuracy ranged from 92 to 106% for fluorescence detection with mean %CV < 7.5. The mean interday precision for all standards was < 10% of the expected concentration. Excellent linear responses were observed with coefficients of > 0.9999. Good compositional data could be obtained from the analysis of derivatized protein hydrolysates containing as little as 50.5 ng of sample. Therefore, the facile BCEOC derivatization coupled with mass spectrometry allowed the development of a highly sensitive and specific method for the quantitative analysis of trace levels of amino acids and peptides from biological and natural environmental samples. (c) 2005 Elsevier B.V. All rights reserved.

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本文首先对CIMS递阶控制结构研究的现状进行了综述及分析,在此基础上, 发展了一种新的CIMS递阶结构参考模型CIMCSA.并进一步提出了自顶向下和自下向上相结合的CIMS递阶控制系统设计方法。

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本研究根据贵阳市区域内不同土地利用方式,选择了自然土壤、农业土壤和城市土壤为主要研究对象。对表层土壤实行多样点的统计分析、以及典型剖面有机碳迁移过程分析,同时结合同位素地球化学示踪原理,探讨了贵阳市区域内土地利用方式变化对土壤有机碳的影响,以及不同土地利用方式间土壤有机碳的来源和降解过程的差异。主要结论如下: (1) 自然土壤转化为农业土壤后,表层(0~10cm) SOC有较为明显的降低趋势。其中,相对于自然土壤(黄壤) 表层SOC(平均值)而言,玉米地、水田、果园下降了40%左右,菜地下降了15%左右。然而,不同菜地土壤间耕种强度存在较大差异,其SOC变异程度高于其它几类农业土壤(CV=57.07%)。与之相反,农业土壤表层DOC(18.86~48.20mg•L-1)接近或超过自然土壤(10.74~36.30 mg•L-1),且ƒDOC占SOC的比例明显大于自然土壤。其中,玉米地DOC最高(平均值:48.20mg•L-1),菜地次之(平均值:30.00mg•L-1),果园第三(平均值:29.87mg•L-1),水田最低(平均值:18.86mg•L-1),但水田由于干湿交替的影响,DOC的变异程度最大(CV=128.57%)。据此推断,在相同气候条件下,自然土壤转化为农业土壤后,由于表层DOC数量和比例的增加,提高了SOC的迁移性,进而加速了碳素在土壤中的迁移转化进程。 (2) 自然土壤转化为农业土壤后,剖面内部(>10cm)多数层次SOC相对于黄壤和黄色石灰土有明显的增加趋势。且通过对不同类型农业土壤人为干扰强度的调查表明:人为干扰强度越强,剖面中一定深度内SOC增加幅度越大。即:离城市较近的菜地2增长最为突出,果园其次,水田和玉米地相当。离城市较远的菜地1由于受人为干扰层次较浅,且出现了犁底层,剖面内SOC的含量水平与黄色石灰土相当。 (3) 原始土壤经搬运重组后形成城市公路绿化带土壤,表层SOC和DOC变幅较宽、离散程度较大,且没有随时间或植被类型等因素的变化而呈现明显的变化趋势。其中,SOC变异程度依次为新成公路绿化带2(CV=58.0%)、老成公路绿化带(CV=55.5%)、新成公路绿化带1(CV=34.1%)。DOC变异程度依次为新成公路绿化带1(CV=93.8%)、新成公路绿化带2(CV=85.7%)、老成公路绿化带(CV=78.0%)。 (4) 在自然土壤、农业土壤和城市绿化带土壤表层中,DOC与SOC、N、C/N、NO3-、NH4-,以及粘粒含量等的相关性均未达到显著水平。另据方差分析显示:果园、水田、菜地和玉米地表层土壤间DOC、SOC含量均无显著差异,说明农业土壤利用方式不是决定土壤表层SOC和DOC含量的绝对因素;新成公路绿化带1,2和老成公路绿化带表层土壤间DOC、SOC含量均无显著差异,说明植被类别和形成时间不是决定土壤表层SOC和DOC含量的绝对因素。 (5) 自然土壤中,枯枝落叶转化为表层(0~5cm)土壤有机质后,δ13CSOC值升高了1~4‰。通过不同碳源间δ13Corg相互关系的判断,在具备枯枝落叶覆盖的表层土壤中,DOC主要来源于枯枝落叶;而在土壤剖面内,随土壤剖面深度的增加,来自于土壤腐殖类物质的DOC占土壤DOC总量的比例呈增加趋势。在黄壤和黄色石灰土中(>5cm土层),土壤剖面中大多数层次DOC比SOC更富13C。 (6) 大多数农业土壤有机碳δ13C值显示其有机肥源中存在C4-C源。且农业土壤中受碳源多样性的影响,菜地、果园、水田和玉米地表层土壤中δ13CSOC与δ13CDOC的相关性均未达到显著水平。其次,除玉米地土壤剖面外,其它供试农业土壤剖面大多数层次δ13CDOC值比δ13CSOC偏负,说明菜地、果园、水田土壤DOC主要为外源的加入。 (7) C3植被转化为C4植被(林-农生态系统转化)后,玉米地剖面中SOC有2.55%~20.80%源于C4-C,随剖面层次的加深有降低趋势,但表现为“之”字形反复;DOC中C4-C的比例在剖面0~40cm处较为相近(25.94%~34.54%),40cm以下则急剧下降(3.18%~15.65%)。说明玉米地剖面 DOC主要来源于土壤腐殖类物质的转化。与林-农生态系统转变过程中的变化趋势相反,洼地农业土壤退耕弃荒一段时间(林-农-林生态系统转化)后,土壤剖面内C4-C占SOC的比例随土壤层次的加深逐渐增加,变化范围在5.77~26.76%。 (8) 在C3植被转向C4植被(林-农生态系统转化)后,玉米地δ13CSOC值与C4-C、C3-C相关系数(r)分别为0.372和-0.102,δ13CDOC值与C4-C、C3-C相关系数分别为0.131和-0.339,其相关性均未达到显著水平。而再从C4植被转回C3植被后,土壤δ13CSOC与C3-C之间呈显著相关性(r=0.88,n=7),说明退耕弃荒后新加入的C3-C对土壤δ13CSOC值影响较大。其SOC的主要来源于洼地周边坡面土壤的侵蚀堆积物和新生草本植被残体。结合当前SOC降解过程的研究成果,本研究认为:洼地土壤退耕弃荒后一段时间里,土壤SOC可能处于累积大于损失状态。这有利于土壤性状向良性方向发展。 (9) 根据同位素值的相互关系和有机碳的来源调查,判断公路绿化带土壤中C4-C为原始土壤所带来。大气颗粒物和雨水中的DOC是表层土壤DOC的主要来源。公路绿化带土壤剖面中,随着时间的增加,土壤腐殖类物质与DOC的相互转化逐渐加强。 上述结论可为人类认识城市区域(特别是有强烈酸性沉降历史的喀斯特城市区域)土地利用方式改变对土壤碳循环的影响,以及不同土地利用方式间土壤有机碳迁移转化过程提供科学依据,也可为正确评估城市区域土壤与其他圈层间碳循环的源、汇关系提供基础资料。

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Repeated-batch cultures of strawberry cells (Fragaria ananassa cv. Shikinari) subjected to four medium-shift procedures (constant LS medium, constant B5 medium, alternation between LS and B5 starting from LS and alternation between LS and B5 starting from B5) were investigated for the enhanced anthocyanin productivity. To determine the optimum period for repeated batch cultures, two medium-shift periods of 9 and 14 days were studied, which represent the end of the exponential growth phase and the stationary phase. By comparison with the corresponding batch cultures, higher anthocyanin productivity was achieved for all the repeated-batch cultures at a 9-day medium-shift period. The average anthocyanin productivity was enhanced 1.7-and 1.76-fold by repeated-batch cultures in constant LS and constant B5 medium at a 9-day shift period for 45 days, respectively. No further improvement was observed when the medium was alternated between LS (the growth medium) and B5 (the production medium). Anthocyanin production was unstable at a 14-day shift period regardless of the medium-shift procedures. The results show that it is feasible to improve anthocyanin production by a repeated-batch culture of strawberry cells.

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Based on social survey data conducted by local research group in some counties executed in the nearly past five years in China, the author proposed and solved two kernel problems in the field of social situation forecasting: i) How can the attitudes’ data on individual level be integrated with social situation data on macrolevel; ii) How can the powers of forecasting models’ constructed by different statistic methods be compared? Five integrative statistics were applied to the research: 1) algorithm average (MEAN); 2) standard deviation (SD); 3) coefficient variability (CV); 4) mixed secondary moment (M2); 5) Tendency (TD). To solve the former problem, the five statistics were taken to synthesize the individual and mocrolevel data of social situations on the levels of counties’ regions, and form novel integrative datasets, from the basis of which, the latter problem was accomplished by the author: modeling methods such as Multiple Regression Analysis (MRA), Discriminant Analysis (DA) and Support Vector Machine (SVM) were used to construct several forecasting models. Meanwhile, on the dimensions of stepwise vs. enter, short-term vs. long-term forecasting and different integrative (statistic) models, meta-analysis and power analysis were taken to compare the predicting power of each model within and among modeling methods. Finally, it can be concluded from the research of the dissertation: 1) Exactly significant difference exists among different integrative (statistic) models, in which, tendency (TD) integrative models have the highest power, but coefficient variability (CV) ones have the lowest; 2) There is no significant difference of the power between stepwise and enter models as well as short-term and long-term forecasting models; 3) There is significant difference among models constructed by different methods, of which, support vector machine (SVM) has the highest statistic power. This research founded basis in all facets for exploring the optimal forecasting models of social situation’s more deeply, further more, it is the first time methods of meta-analysis and power analysis were immersed into the assessments of such forecasting models.

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Obsessive-Compulsive Symptoms, which are one of common factors effected on mental health of secondary school students, have been rarely studied at home and abroad. In accordance with the problems existed in these literature up till now, the thesis had mainly studied the measured tool, contents and structure, developmental features, psychosocial risk factors and integrated model of obsessive-compulsive symptoms from them by means of investigation with quetionnaires. The entire research was divided into three phases. 3185 students(age 14.68±1.75 years) were firstly measured with the 20-item Leyton Obsessional Inventory-Child Version(LOI-CV) at four secondary schools including six grades in Beijing city, which was applied to revise LOI-CV, and to study the structure and contents, developmental features and screen of obsessive-compulsive symptoms. Then, 216 subjects with obsessive-compulsive symptoms, paired with controls in the light of school, grade and gender, were investigated with 10 self-rating scales on obsessive-compulsive symptoms, anxiety, depression, personality, coping and attributional style, negative life events, parent's rearing style, family environment and life adaptation in school, and with an inventory on social demography. The results were used to explore psychosocial risk factors and integrated model of obsessive-compulsive symptoms. The third survey was only carried out, about two months after the second, among 264 subjects with obsessive-compulsive symptoms through MMOCI and Negative Life Event Scale for Adolescents, in order to probe into the integrated model. The research had mainly found: (1) LOI-CV can be used as a screen tool for obsessive-compulsive symptoms in urban adolescents in China; (2) Total screening-out ratio of obsessive-compulsive symptoms was 13.6% (male:15.0%, female:12.2%). The most common manifestations of obsessive-compulsive symptoms were hating dirt and contamination, doing things in exact manner, angry if someone messes desk, bad conscience but no one else, worry about cleanliness, repeated thoughts or words; the least were favorite or special number, spending extra time on homework, special number or words to avoid, talking or moving to avoid bad luck, fussy about hands. The checking and repetition, cleanliness and tidiness, general obsessions were more common forms than numbers-luck; (3) No differences were existed in serious degree of obsessive-compulsive symptoms, but the screening-out ratio in male was higher than it in female; (4) No differences were detected in the serious degree of obsessive-compulsive symptoms except the scores of cleanliness and tidiness among grades, but the screening-out ratio of the grades justly entering secondary school or going to graduate were higher than other ones; (5) The main psychosocial risk factors for obsessive-compulsive symptoms included anxiety, mother's over-protecting and over-interfering, fantasy, flexibility, self-actualization, peers relationship, sense of responsibility, negative life events, mother's occupation, help-seeking, and (6) The integrated model on psychosocial risk factors suggested that the possible developed and sustained mechanism of obsessive-compulsive symptoms was that personality, coping and attributional styles constructed the developmental diathesis foundation of obsessive-compulsive symptoms; negative life events were promoting factors of them. There was a dynamic interaction between personality and environmental factors. Negative emotion played a core role in the developmental process of them. The continued existence of obsessive-compulsive symptoms was related to pre-existed obsessive-compulsive symptoms and negative life events experienced by an individual. Therefore, this research not only let us get a deeper understanding of obsessive-compulsive symptoms and more entirely find out psychosocial risk factors, firstly applied diathesis-stress theory to comprehend the psychological mechanism of obsessive-compulsive symptoms and, moreover, elaborate and expand it, but also has more important practice significance of treatment, prevent and education for obsessive-compulsive symptoms in secondary school students.