A bio-inspired computing model as a new tool for modeling ecosystems: The avian scavengers as a case study

The models used for ecosystems modeling are generally based on differential equations. However, in recent years new computational models based on biological processes, or bioinspired models, have arisen, among which are P systems. These are inspired by the functions of cells and present important advantages with respect to traditional models, such as a high computational efficiency, modularity and their ability to work in parallel. They are simple, individual-based models that use biological parameters that can be obtained experimentally. In this work, we present the framework for a model based on P systems applied to the study of an ecosystem in which three avian scavengers (predators) interact with 10 wild and domestic ungulates (preys). The computation time for 100 repetitions, corresponding to 14 simulation years each, with an initial population composed of 385,422 individuals, was 30 min. Our results suggest that the model presented, based on P systems, correctly simulates the population dynamics in the period of time analyzed. We discuss the usefulness of this tool in simulating complex ecosystems dynamics to aid managers, conservationists and policy-makers in making appropriate decisions for the improvement of management and conservation programs.     

基于有限元的含腐蚀缺陷P110油管失效分析与安全评价

含有腐蚀缺陷油管在复杂的工作荷载下容易发生失效。建立了在内压与轴向力共同作用的复杂工作载荷下,含椭球型蚀坑缺陷与轴向沟槽型缺陷两种腐蚀缺陷的油管有限元模型。基于该模型研究了不同载荷工况下缺陷宽度、深度与长度对油管安全性及失效模式的影响。研究结果表明:腐蚀位置深度较浅时,椭球型蚀坑缺陷更危险,油管主要发生由轴力引发的断裂失效;腐蚀位置深度较深时,轴向沟槽型缺陷更危险,主要发生由内压引发的破裂失效。研究成果可为含腐蚀缺陷油管的安全评估提供依据。     

小震震源机制P轴取向的预报应用

采用Snoke的振幅比方法,利用江苏台网和山东台网记录到的数字化波形资料,计算了发生在江苏及其附近地区的33个地震的震源机制解,并由此计算了其相应的P轴取向。结果表明:南黄海北部凹陷地区M_L5.1地震发生前2个月内、长江口地区显著小震群发生之前2个月内,在震中所在区域的附近地区有震源P轴取向小于100°的异常地震发生;盐城附近及其近海海域在本文研究的时段内未曾出现震源P轴取向小于100°的地震,该区域也没有发生中强地震或显著小震群事件。由此说明震源P轴取向具有一定的短临前兆意义,但这种情况与大地震事件所表现出来的规律并不完全相同。茅山断裂附近地区出现的2次震源P轴取向小于100°的事件与该地区重力异常结果是一致的,说明2002年前后茅山断裂曾活动过。     

胞外聚合物在生物膜同步去除/富集磷酸盐系统中的作用

以基于同步去除/富集磷酸盐的厌氧/好氧交替生物膜序批式反应器内生物膜为研究对象,研究了胞外聚合物(EPS)内磷含量形态及生物膜内微生物种群变化,探究EPS在生物膜去除/富集磷酸盐中的作用及其与微生物种群之间的联系.结果 表明,生物膜反应器在厌氧外加COD为200 mg·L-1的条件下富集到了磷浓度为120.95 mg·...     

黄曲霉素B1-DNA加合物的实验研究

用＾３２Ｐ后标记的方法测小牛胸腺ＤＮＡ和黄曲霉素Ｂ１体外反应产物里的ＤＮＡ－ＡＦＢ加合物，发现有４种不贩的ＤＮＡ加合物，加合物含量的ＲＡＬ＝１．０８／１０＾７（正常核酸），对比用ＤＮＡ的４种碱基和ＡＦＢ１反应所形成的加合物，发现有３种ＤＮＡ－ＡＦＢ１的加合物是来自鸟嘌呤碱基修饰所形成的。     

难降解有机物对白腐真菌P450的诱导及P450的作用

实验考察了多环芳烃和氯酚类化合物对黄孢原毛平革菌P450的诱导作用及其P450对生物降解的影响.结果表明,萘、菲、2,4-二氯酚、五氯酚能够诱导该真菌P450,使微粒体P450比浓度达到37~137pmol/mg.在营养限制条件下,菲诱导的P450是营养丰富条件的5.7倍;P450抑制剂的作用使萘、菲、芘、2,4-二氯酚的降解效率下降36%~100%,但是对2,4,6-三氯酚和五氯酚的降解未产生影响.在营养丰富条件下,P450抑制剂的作用使萘、菲、芘、2,4,6-三氯酚的降解效率下降47%~100%,使五氯酚的降解效率增大57%,但对2,4-二氯酚的降解未产生影响.     

新农药单甲脒对棉花的生态生理影响

两年的研究结果表明：单甲脒推荐浓度－稀释１０００倍对棉花的生理机能有些促进作用，其水分利用效率正常；其他处理浓度对光合速率也无不良影响，对气孔开度、蒸腾速率仅在施药初期略有抑制，半衰期后抑制消失，稀释５００倍以下各处理水分利用效率受到不同程度的抑制。单甲脒在棉叶残留量最多，伴随着叶片的Ｎ、Ｐ含量也略增加，可认为适量的施用单甲脒不仅能防治虫害、且能促进棉花的光合速率从而提高了干物质生产。     

芳香化合物羟基化酶研究进展

芳香族化合物的选择性羟基化是合成化学中最具挑战性的化学反应之一,特别是由于近年来羟基芳香族化合物在医学上作为前驱体使用,使其越来越受到重视.通过单一酶或者整个微生物细胞进行的生物催化氧传递,是完成芳香化合物选择性羟基化反应的一种有效方式,不仅在受污染环境的生物修复中作用重大,而且还可以替代并拓宽传统的化工合成工艺,广泛用于化工中间体的生产,这使得芳香化合物羟化酶成为重要的工业用酶之一.本文综述了芳香化合物羟基化酶的种类、作用机理及工业应用等方面的最新研究进展.图5表1参42     

Country-scale phosphorus balancing as a base for resources conservation

In order to effectively conserve the non-renewable resource phosphorus (P), flows and stocks of P must be known at national, regional and global scales. P is a key non-renewable resource because its use as fertilizer cannot be substituted posing a constraint on the global food production in the long-term. This paper presents a methodology to establish country-wide P balances that emphasises resource use. We develop a material flow analysis (MFA) model that comprises all relevant flows and stocks of P in five subsystems, seven processes and 36 material flows. For quantification, statistical data from economic and agricultural sources as well as available information about P partitioning in natural and anthropogenic processes are used. Special attention is paid to data gaps and uncertainties. The model was tested in two case studies on P management in Turkey and Austria. MFA appears to be a tool well suited for establishing country-wide P balances, provided that national statistics are well-structured and accessible. If a common approach is used for modelling P-flows and stocks, regional and national balances can be compared and linked towards larger scale P balances for an improved management of the resource.     

Effects of metal lead on growth and mycorrhizae of an invasive plant species （Solidago canadensis L.）

It is less known whether and how soil metal lead (Pb) impacts the invasion of exotic plants.A greenhouse experiment was conducted to estimate the effects of lead on the growth and mycorrhizae of an invasive species(Solidago canadensis L.)in a microcosm system. Each microcosm unit was separated into HOST and TEST compartments by a replaceable mesh screen that allowed arbuscular mycorrhizal (AM) fungal hyphae rather than plant roots to grow into the TEST compartments.Three Pb levels(control,300,and 600 mg/kg soil)were used in this study to simulate ambient soil and two pollution sites where S. canadensis grows.Mycorrhizal inoculum comprised five indigenous arbuscular mycorrhizal fungal species (Glomus mosseae,Glomus versiform,Glomus diaphanum,Glomus geosporum,and Glomus etunicatum).The 15N isotope tracer was used to quantify the mycorrhizally mediated nitrogen acquisition of plants.The results showed that S. canadensis was highly dependent on mvcOrrhizae.The Pb additions significantly decreased biomass and arbuscular mycorrhizal colonization(root length colonized,RLC%) but did not affect spore numbers,N(including total N and 15N) and P uptake.The facilitating efficiency of mycorrhizae on nutrient acquisition was promoted by Pb treatments.The Pb was mostly sequestered in belowground of plant (root and rhizome).The results suggest that the high efficiency of mycorrhizae on nutrient uptake mightgive S. canadensis a great advantage over native species in Pb polluted softs.