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111.
本文研究探讨了进化地位不同的三种动物的短时空间记忆功能及其与前额叶背侧部进化水平的相关性。结果表明,在延缓反应作业中,经1000次训练后,7只恒河猴对空间位置的记忆时间平均为7.7±3.2min,懒猴为3.8±0.44min,而树鼩即使在延缓时间几乎为零秒的延缓反应中,其正确反应率也未达到90%标准。一种延缓时间仅测试一个单元,即不经训练的实验表明,恒河猴在延缓期为“0”—5min的各测试单元中,正确反应率稳定在80%以上;懒猴在延缓时间为“0”—4min的各测试单元中,平均正确反应率与恒河猴无明显差异,而当延缓时间增加到5min时,在延缓反应作业中取得的成绩显著下降;树鼩在延缓时间为1—5min的作业中取得的正确反应率在70%以下。3种动物在视觉辨别学习作业中却无明显差异。形态学研究表明,灵长类大脑前额叶的面积和结构的复杂性在进化过程中逐渐增大,如恒河猴大脑前额叶的表面积占大脑半球表面积的11.5%(Brodmann,1929),其内颗粒层发达,背侧部明显凸起,主沟区发达;懒猴的前额叶表面积占其大脑半球表面积的8.3%,背侧部凸起不显著,主沟未形成,额极内颗粒层分化明显,背侧部的内颗粒层较内侧部的发达程度差(Sanides,1967);树鼩的前额叶表面积占7.5%,额极的内颗粒层分化不明显,为非颗粒化区,此区之后为颗粒区 相似文献
112.
本文对蛋白质中二硫键附近的残基进行了计算机统计分析,结果发现平行和反平行残基间存在着特异的配对规律。这种残基间的相互作用或识别,可能与蛋白质折叠过程中正确地形成二硫键有关。该结果有助于蛋白质工程设计。 相似文献
113.
Mateusz Okrutniak Irena M. Grześ Anna K. Kucharska Filip Turza Małgorzata Zimocha Sabrina Kerdiane Patryk Jabłoński 《Entomological Science》2023,26(3):e12549
In ants, workers of different sizes may perform various tasks, even in so-called monomorphic species with relatively low body size variation. However, it is unclear if the body size diversity of monomorphic workers correlates with task efficiency, especially in stressful contingencies. Here we tested if the body size variation of workers corresponds with its efficiency in transferring pupae. Transferring brood is a pre-set behavioral response to stress, e.g. suboptimal temperature. Here we applied a laboratory experiment simulating nest damage. The study was performed on the common garden ant (Lasius niger (Linnaeus, 1758)) – a species with no distinct worker subcastes. The efficiency of workers was measured as the latency of transferring pupae from a lit part of the experimental colony to a darkened part, while the body size diversity was expressed as the within-colony coefficient of variation in head width. We did not find any significant correlation between efficiency and body size variation. Summarizing the existing studies and the present results, we propose the hypothesis that the body size diversity of L. niger may have implications for workers’ division of labor but not for their task efficiency in a stressful contingency. 相似文献
114.
Huili Feng Jiahuan Guo Changhui Peng Daniel Kneeshaw Gabrielle Roberge Chang Pan Xuehong Ma Dan Zhou Weifeng Wang 《Global Change Biology》2023,29(14):3970-3989
A significant increase in reactive nitrogen (N) added to terrestrial ecosystems through agricultural fertilization or atmospheric deposition is considered to be one of the most widespread drivers of global change. Modifying biomass allocation is one primary strategy for maximizing plant growth rate, survival, and adaptability to various biotic and abiotic stresses. However, there is much uncertainty as to whether and how plant biomass allocation strategies change in response to increased N inputs in terrestrial ecosystems. Here, we synthesized 3516 paired observations of plant biomass and their components related to N additions across terrestrial ecosystems worldwide. Our meta-analysis reveals that N addition (ranging from 1.08 to 113.81 g m−2 year−1) increased terrestrial plant biomass by 55.6% on average. N addition has increased plant stem mass fraction, shoot mass fraction, and leaf mass fraction by 13.8%, 12.9%, and 13.4%, respectively, but with an associated decrease in plant reproductive mass (including flower and fruit biomass) fraction by 3.4%. We further documented a reduction in plant root-shoot ratio and root mass fraction by 27% (21.8%–32.1%) and 14.7% (11.6%–17.8%), respectively, in response to N addition. Meta-regression results showed that N addition effects on plant biomass were positively correlated with mean annual temperature, soil available phosphorus, soil total potassium, specific leaf area, and leaf area per plant. Nevertheless, they were negatively correlated with soil total N, leaf carbon/N ratio, leaf carbon and N content per leaf area, as well as the amount and duration of N addition. In summary, our meta-analysis suggests that N addition may alter terrestrial plant biomass allocation strategies, leading to more biomass being allocated to aboveground organs than belowground organs and growth versus reproductive trade-offs. At the global scale, leaf functional traits may dictate how plant species change their biomass allocation pattern in response to N addition. 相似文献
115.
本文报道对中国新疆东部一起戊型肝炎流行高峰期间,由HE患者烘便中分离到的型肝炎病毒中国XT-179株进行全基因cDNA克隆、核苷酸和氨基酸序列测定及分析结果。所阐明的HEV-XT-179株基因组全序列由7194个核苷酸和3'端的多聚腺嘌呤核苷酸尾组成。四种核苷酸的含量腺嘌呤(A)为17.0%,胞嘧啶(C)为31.9%,鸟嘌呤(G)为26.0,尿嘧啶(U)为25.1%。G+C含量为57.9%。全基因 相似文献
116.
117.
Maja Wiprächtiger Melanie Haupt Andreas Froemelt Magdalena Klotz Claudio Beretta Dominik Osterwalder Vanessa Burg Stefanie Hellweg 《Journal of Industrial Ecology》2023,27(1):254-271
Industrial ecology (IE) methodologies, such as input/output or material flow analysis and life cycle assessment (LCA), are often used for the environmental evaluation of circular economy strategies. Up to now, an approach that utilizes these methods in a systematic, integrated framework for a holistic assessment of a geographic region's sustainable circular economy potential has been lacking. The approach developed in this study (IE4CE approach) combines IE methodologies to determine the environmental impact mitigation potential of circular economy strategies for a defined geographic region. The approach foresees five steps. First, input/output analysis helps identify sectors with high environmental impacts. Second, a refined analysis is conducted using material flow and LCA. In step 3, circular strategies are used for scenario design and evaluated in step 4. In step 5, the assessment results are compiled and compared across sectors. The approach was applied to a case study of Switzerland, analyzing 8 sectors and more than 30 scenarios in depth. Carbon capture and storage (CCS) from waste incineration, biogas and cement production, food waste prevention in households, hospitality and production, and the increased recycling of plastics had the highest mitigation potential. Most of the scenarios do not influence each other. One exception is the CCS scenarios: waste avoidance scenarios decrease the reduction potential of CCS. A combination of scenarios from different sectors, including their impact on the CCS scenario potential, led to an environmental impact mitigation potential of 11.9 Mt CO2-eq for 2050, which equals 14% of Switzerland's current consumption-based impacts. 相似文献
118.
Immunolocalization of the G protein alpha subunit encoded by the GPA1 gene in Arabidopsis. 总被引:4,自引:0,他引:4 下载免费PDF全文
Heterotrimeric GTP binding proteins (G proteins) are important signal transducers in lower eukaryotes and in animal cells. In plants, the occurrence of GTP binding proteins has been reported, but their biological function remains unclear. Two genes coding for G protein alpha subunits have been cloned: GPA1 in Arabidopsis and TGA1 in tomato. To gain some insights into the function of GPA1, we describe an extensive immunolocalization of GPalpha1, the gene product of GPA1, during Arabidopsis development. Our results show that the GPalpha1 is present through all stages of development and in all organs examined, with the exception of mature seeds. It is expressed in roots, floral stem, rosette leaves, cauline leaves, flowers, and seed pods. Interestingly, the level of GPalpha1 protein is higher in immature organs than in mature organs. GPalpha1 is present at a high level in the root meristem and elongation zone, in the shoot and floral meristems, and in the leaf primordium and floral organ (sepal, petal, stamen, and gynoecium) primordia. During flower development, dividing microspores, but not mature pollen, show high levels of GPalpha1. During pollination, GPalpha1 is present in the growing pollen tubes. The protein is also present in nectaries and developing ovules and, after fertilization, in developing embryos. In mature tissue, GPalpha1 is preferentially found in the vascular system but is also present in other cell types. The complexity of the GPalpha1 localization pattern suggests that GPalpha1 might be involved in different signaling pathways depending on the developmental stage. 相似文献
119.
Le Maître Anne Guy Franck Merceron Gildas Kostopoulos Dimitris S. 《International journal of primatology》2023,44(1):209-236
International Journal of Primatology - Discoveries in recent decades indicate that the large papionin monkeys Paradolipopithecus and Procynocephalus are key members of the Late Pliocene –... 相似文献
120.
To develop new highly effective anticancer agents derived from naturally occurring stilbene scaffold, in total of 24 indole and indazole-based stilbenes including 17 new compounds were designed according to molecular hybridization strategy and synthesized via Witting reaction. The cytotoxic screening results against human tumor cell lines (K562 cells and MDA-MB-231 cells) showed that indole and indazole-based stilbenes are of great interest for developing anticancer agents as eight derivatives possessed strong antiproliferative activities with IC50 values less than 10 μM, and those synthetic derivatives displayed more higher cytotoxicities against K562 cells than MDA-MB-231 cells. In particular, indole-based stilbene bearing piperidine exhibited the most potent cytotoxicities against both K562 and MDA-MB-231 cells with IC50 values 2.4 μM and 2.18 μM, respectively, along with a remarkable selectivity towards human normal L-02 cells. Together, the results suggested that indole and indazole-based stilbenes are promising anticancer scaffolds worthy of further investigation. 相似文献