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31.
Tatsuro Kono 《Population Ecology》1953,2(1):85-94
Contributions from the Entomological Laboratory, Kyoto University, No. 230. 相似文献
32.
A new fossil brachypterous psocid tax on belonging to the family Trogiidae is characterized, illustrated and described from the early Eocene Fushun amber. Paralepinotus fushunensis nov. gen., nov. sp., shares several characters with the genus Lepinotus von Heyden, 1850, but differs from it mainly by the presence of tibial spurs other than apical ones and the absence of a forked sensillum on the last maxillary palp. This fossil taxon is also characterized by relatively developed elytriform forewing but still not reaching the tip of the abdomen. A checklist of all known Trogiidae is provided. 相似文献
33.
Zehang Jiang Zhixian Liu Mengyuan Li Cai Chen Xiaosheng Wang 《Translational oncology》2018,11(5):1171-1187
Although immunotherapy continues to demonstrate efficacy in a variety of refractory cancers, currently, no any immunotherapeutic strategy is clinically used for gastric cancer (GC) except its microsatellite instable subtype. Thus, it is important to identify molecular biomarkers for predicting the responders to GC immunotherapy. TP53 mutations frequently occur in GC and are associated with unfavorable clinical outcomes in GC. We performed a comprehensive characterization of the associations between TP53 mutations and immune activities in GC based on two large-scale GC cancer genomics data. We compared expression and enrichment levels of 787 immune-related genes and 23 immune gene-sets among TP53-mutated GCs, TP53‐wildtype GCs, and normal tissue, and explored the correlations between p53-mediated pathways and immune activities in GC. Strikingly, almost all analyzed immune gene-sets were significantly downregulated in enrichment levels in TP53-mutated GCs compared to TP53‐wildtype GCs. These less active immune pathways and cell types in TP53-mutated GCs included 15 immune cell types and function, tumor-infiltrating lymphocytes, regulatory T cells, immune checkpoint, cytokine and cytokine receptor, human leukocyte antigen, pro‐inflammatory, and parainflammation. Moreover, we identified a number of p53-mediated pathways and proteins that were significantly associated with immune activities in GC. Furthermore, we demonstrated that the TP53 mutation itself could result in the depressed immune activities in GC and other cancer types. We revealed that chromosomal instability was an important mechanism for the depressed tumor immunity in TP53-mutated cancers. Finally, we showed that immune cell infiltration and immune activities were likely positively associated with survival prognosis in GC. Our findings suggest that p53 may play an important role in activating tumor immunity in GC and other cancer types and that the TP53 mutation status could be useful in stratifying cancer patients responsive to a certain immunotherapy. 相似文献
34.
35.
叶面积指数(Leaf Area Index,LAI)高度综合了植被水平覆盖状况和垂直结构,以及枯枝落叶层厚薄和地下生物量多少,是植被影响土壤侵蚀的主要方面。区域尺度的时间序列叶面积指数揭示了区域土壤侵蚀的演化过程。因此,及时准确地掌握区域尺度上长时间序列的植被LAI,对研究土壤侵蚀动态变化与植被的关系至关重要。选择南京市1988-2013年10期遥感影像,基于反向传播(Back Propagation,BP)神经网络构建LAI反演模型,进行了长时间序列的叶面积指数反演。结合2009和2010年LAI实测值,验证与探讨了该模型的评价精度与适应性。结果表明:(1)该模型拟合度较高,2009和2010年平均相对误差、均方根误差、相关系数分别是0.2395和0.2174,0.2962和0.2581,0.7713和0.6844,各项精度评价指标均较好;(2)统计分析去除耕地后全市LAI变化,低植被覆盖(LAI<2)面积不断增加,高植被覆盖区(LAI>3)面积先减少后增加,耕地面积不断减少,符合南京市的发展变化规律;(3)主城区LAI年际变化与其他学者得到的南京市植被盖度变化趋势一致,反演结果的时序性较高。本文提出的基于反向传播神经网络模型反演长时间序列LAI是可行的,为区域尺度土壤侵蚀定量遥感监测提供新途径。 相似文献
36.
BACKGROUND AND AIMS: Species of the Nepenthaceae family are under-represented in studies of leaf traits and the consequent view of mineral nutrition and limitation in carnivorous plants. This study is aimed to complement existing data on leaf traits of carnivorous plants. METHODS: Physico-chemical properties, including construction costs (CC), of the assimilatory organs (leaf and pitcher) of a guild of lowland Nepenthes species inhabiting heath and/or peat swamp forests of Brunei, Northern Borneo were determined. KEY RESULTS: Stoichiometry analyses indicate that Nepenthes species are nitrogen limited. Most traits vary appreciably across species, but greater variations exist between the assimilatory organs. Organ mass per unit area, dry matter tissue concentration (density), nitrogen (N), phosphorus (P), carbon, heat of combustion (H(c)) and CC values were higher in the leaf relative to the pitcher, while organ thickness, potassium (K) and ash showed the opposite trend. Cross-species correlations indicate that joint rather than individual consideration of the leaf and the pitcher give better predictive relationships between variables, signalling tight coupling and functional interdependence of the two assimilatory organs. Across species, mass-based CC did not vary with N or P, but increases significantly with tissue density, carbon and H(c), and decreases with K and ash contents. Area-based CC gave the same trends (though weaker in strength) in addition to a significant positive correlation with tissue mass per unit area. CONCLUSIONS: The lower CC value for the pitcher is in agreement with the concept of low marginal cost for carnivory relative to conventional autotrophy. The poor explanatory power of N, P or N : P ratio with CC suggests that factors other than production of expensive photosynthetic machinery (which calls for a high N input), including concentrations of lignin, wax/lipids or osmoregulatory ions like K(+), may give a better explanation of the CC variation across Nepenthes species. 相似文献
37.
基于生态足迹方法的南京可持续发展研究 总被引:8,自引:0,他引:8
20世纪90年代末以来,随着南京城市化进程的加快和城市建成区面积的扩展,城市生态安全问题日益突出。在运用生态足迹方法分析南京市1999—2009年人均生态足迹及生态承载力变化的基础上,采用Mann-kendall法对南京市人均生态足迹突变点进行分析,应用灰色关联模型从经济、社会和生态子系统方面分析不同阶段人均生态足迹变化的原因。研究表明:1999—2009年间南京市人均生态足迹呈增长趋势,人均生态承载力呈减小趋势,单位万元GDP生态足迹和生态多样性指数呈逐年下降趋势,生态经济系统发展能力较好,但生态压力较大。南京市人均生态足迹变化分为1999—2002年的低位增长阶段和2003—2009年高位波动阶段。通过影响南京市生态足迹变化因素分析发现,2003—2009年与1999—2002年相比,经济子系统依然处于主要地位,但影响因素由农业向以三产为主转变,同时生态子系统和社会子系统各因素的影响力提升。据此,提出优化产业结构,控制人口数量,加强基础设施建设,改善居民居住环境,加大城市绿化建设,提高城市污物处理能力,减少污染物排放的南京可持续发展对策。 相似文献
38.
快速城市化对南京东郊景观结构与格局的影响 总被引:3,自引:0,他引:3
城市化对区域景观的影响日益显著,如何协调城市区域土地开发与生态保护的关系,成为重要的基础性问题之一。本文以南京仙林新市区为案例,利用遥感和GIS方法,对研究区景观结构和格局变化进行分析。结果表明:2003—2009年,研究区景观结构发生了巨大的变化,区域主导景观类型已经由半自然半人工景观逐渐转变为人工景观。其中耕地受人为影响变化较大,55.6%的面积消失;水塘以数量丧失为基本特征,丧失率为56.4%;建筑用地面积增加明显,年均增加7.1%。伴随景观结构变化,区域景观格局变化十分明显,其中景观多样性指数从1.38升高为1.68;均匀度指数从0.60变成0.73;连接度指数由0.15变为0.32。 相似文献
39.
Lyudmila G. Nikolaeva Tatiana V. Maystat Volodymyr S. Pylypchuk Yuri L. Volyanskii Valery M. Frolov Galyna A. Kutsyna 《Cytokine》2008,44(3):392-396
Dzherelo (Immunoxel) and Anemin when combined with standard anti-tuberculosis therapy (ATT) were shown to produce better clinical outcome than chemotherapy alone. Sixty HIV-positive patients with active pulmonary TB were equally divided into three matched groups to receive either ATT, ATT + Dzherelo, or ATT + Dzherelo + Anemin. Peripheral blood samples were measured by ELISA for plasma levels of IL-2, IL-6, TNF-α, IFN-γ, and IFN-α. After 6 months of follow-up Dzherelo and Dzherelo + Anemin combinations produced 61% (P = 0.005) and 44.4% (P = 0.06) higher levels of IL-2, whereas in ATT group they were reduced by 33.1% (P = 0.002). The levels of IL-6 increased by 17% (P = 0.15) in ATT group, but declined in both immune intervention groups by 26.2% (P = 0.007) and 21.3% (P = 0.22). TNF-α was suppressed in two immunotherapy groups by 19.1% (P = 0.06) and 76.3% (P = 0.02), respectively, but had risen by 14% (P = 0.42) in ATT patients. The pattern of production of IFN-γ was opposite to that of TNF-α, but statistical significance was stronger in patients receiving ATT and Dzherelo + Anemin than in Dzherelo group: −34% (P = 0.004), +31.9% (P = 0.008), and +17.3% (P = 0.33), respectively. Moderately decreased levels of IFN-α were observed in all treatment arms (range 0.9–16.6%) but differences were not significant. Despite considerable intra-group variation in cytokine production, the baseline inter-group averages were not statistically different indicating that the results were not biased by sample heterogeneity. Immunomodulators used in this study possibly act by enhancing natural immune response against TB. Expanded study of other cytokines and correlates relevant to control and protection from TB and HIV is needed in order to identify biomarkers of favorable treatment outcome, which may aid design of better immune interventions and vaccines. 相似文献
40.
Richard A. Fuller Philip H. Warren Paul R. Armsworth Olga Barbosa Kevin J. Gaston 《Diversity & distributions》2008,14(1):131-137
Households across the developed world cumulatively spend many millions of dollars annually on feeding garden birds. While beneficial effects on avian assemblages are frequently claimed, the relationships between levels of garden bird feeding and local avian populations are unknown. Using data from a large UK city, we show that both avian species richness and abundance vary across different socioeconomic neighbourhood types. We examined whether patterns in bird feeding could explain this variation. The density of bird feeding stations across the urban environment was strongly positively related to avian abundance, after controlling for differences in habitat availability. This effect was almost exclusively driven by the abundance of those species known to utilize garden feeding stations frequently. In contrast, the density of feeding stations had no effect on avian species richness. We also examined variation in the proportion of households in different communities that provide food for birds, a factor that is not correlated with feeder density. The prevalence of bird feeding across different neighbourhoods declined as socioeconomic deprivation increased, and increased with avian species richness and abundance. Our results suggest that the provision of supplementary food for birds by multiple landowners across a city can impact the status of urban bird populations. The potential for harnessing these actions for conservation needs to be explored. 相似文献