漫谈集群绝灭（上）：什么是集群绝灭

漫谈集群绝灭（上）——什么是集群绝灭徐星王原邵颖编译在地球的历史进程中,发生过多次的生物集群绝灭事件。其中,最为著名的一次是发生在白垩纪末期的恐龙大绝灭事件（见图一）。这些绝灭事件引起了科学家们的极大兴趣,因为这不仅关系到生物演化的进程,也涉及到我们...     

生物矿化硬体（生物矿物体）的分类和演化

生物矿化硬体（生物矿物体）的分类和演化戴永定，沈继英（中国科学院地质研究所北京１０００２９）关键词生矿体类型，门类分布，生成顺序，演化趋势生物矿化硬体亦称生物矿物体，简称生矿体，指生物分泌而形成的无机化合物晶质或非晶质微粒及其集合体。它包括宏观的脊椎...     

泥盆纪最早期和最晚期珊瑚群研究的进展——兼论泥盆纪珊瑚的绝灭、复苏及其底栖组合

由于志留泥盆纪之间没有发生明显的生物更替现象,所以泥盆纪最早期（Ｌｏｃｈｋｏｖｉａｎ）的珊瑚仍保留着浓厚的志留纪珊瑚的色彩。真正的泥盆纪类型的珊瑚是从早泥盆世中期（Ｐｒａｇｉａｎ）才开始兴起的,至晚泥盆世早期（Ｆｒａｓｎｉａｎ）末惨遭绝灭。晚泥盆世晚期（Ｆａｍｅｎｎｉａｎ）的珊瑚却与石炭纪珊瑚有着较为密切的关系。晚泥盆世的珊瑚经历了绝灭残存复苏３个发展阶段。泥盆石炭纪之交,泥盆纪最晚期（Ｓｔｒｕｎｉａｎ）的珊瑚再遭绝灭,至石炭纪初代之于Ｔｏｕｒｎａｉｓｉａｎ型的珊瑚。正当华南锡矿山（相当于Ｆａｍｅｎｎｉａｎ早期）的珊瑚群罹难的时刻,新疆北部洪古勒楞（亦相当于Ｆａｍｅｎｎｉａｎ早期）却形成了Ｆ／Ｆ大绝灭后生物理想的避难所。     

生物系统中的矿物

生物矿物主要包括钙镁（铁锰）碳酸盐，钙镁多（铁）磷酸盐、二氧化硅、铁锰（镁）氧化物和氢氧化物、硫酸盐和硫化物、有机酸盐和卤化物。其主要特征为弱减弱酸盐，多呈钙化合物、氧化物或含氧盐（特别是碳酸盐和磷酸盐）多含结晶水或羟基。在生物类型分布上，在个体发生过程中，在地质历史发展中，生物矿物存在着一种演化趋向，即从硫化物→硫酸盐→铁氧化物和氢氧化物→非晶硅→钙白云石→碳磷石灰→镁方解石→文石→方解石。     

生物复杂性研究动态

生物复杂性（biocomplexity或biological complexity）是近年来由Rita Colwell等人积极倡导的一个新的学科领域,旨在更好地了解生命系统及其环境组分间的相互作用以及系统复杂性的动态特征与演化机制,目前,生物复杂性的定义与内涵尚不明确,意见纷呈,而有关研究在美国国家科学基金会（NSF）的支持下已迅速开展起来,并即将成为国际合作研究的热点之一。本文简要介绍了有关生物复杂性的不同观点、生物复杂性与生物多样性研究之间的关系,并以若干生态系统和基因组为例,说明了现阶段生物复杂性研究的主要特点。     

11,000年前生物大绝灭的原因——"天地生人"系列讲座(十)

在第9讲，我们向读者介绍了一件事实：在距今11，000年前，在我们生活的地球上曾发生过一次生物大绝灭。它是继恐龙绝灭之后又一次大的绝灭事件，是哺乳动物进化历史上最大规模的绝灭事件。     

寿终者绝灭,创新者生存——"天地生人"系列讲座(19)

在地球的历史上至少存在着 16种不同层次的大年 (米切尔 ,1976)。其中对生物界的演化曾起过重要作用的大年约有下列 6种 :宏年 ,代年 ,纪年 ,世年 ,期年 ,事件年。在上述 6种层次的大年的冬末 ,生物界都发生了绝灭事件。如在 3个宏年的冬末 ,世界上曾分别发生过 3次著名的大绝灭事件。在前一讲已经对此做过系统的介绍 ,故这里不赘述了。在每个代年的冬末 ,绝灭事件的影响也不小。如发生在中生代年冬末的恐龙大绝灭事件 ,可谓妇孺皆知。在 12个纪年的冬末 ,绝灭事件的规模还相当大 ,如奥陶大绝灭、泥盆大绝灭、三叠大绝灭等皆被古生物学家归…     

世界真奇妙--"天地生人"系列讲座(29)

在显生宙,从宏年,代年,纪年,世年,期年到事件年共6个层次,在不同层次的大年的冬末,生物界都会发生相应层次的绝灭事件。大年的层次越高,绝灭事件的规模或影响便越大。换句话说,大年的冬末乃是生物界淘汰旧物种的季节,这是生物事件的第一幕。冬去春来,经过生物事件第二幕的短暂间隔后,不同层次的大年的春季就降临了。此时生物界会出现相应层次的辐射或爆发事件,表现为一批新物种的诞生。     

生物再生及其相关的几个问题

人类对生物科学的研究,经历了一个从生物宏观现象描述到个体生物形态的解剖,从生物个体形态解剖到生物机能微观分析的发展过程。再生现象广泛存在于整个生物界,它与生物的发育、生长、繁殖等诸多方面息息相关。尤其是飞速发展的现代生物学及其相关学科的许多研究领域的问题,如农林学方面的科学育种、快速繁殖涉及的接合力和组织培养的关键性问题,医学手术中的伤口愈合等等,无不与生物的再生相联系。所以作者深信:对生物再生现象在生物界广泛性的重视;对生物再生现象意义和作用的     

生命的历程系列讲座(十四) 三叠纪生物复苏

正二叠纪末生物大灭绝是显生宙以来最大的灭绝事件,它重创和毁坏了古生代生态系统,打破了生物与环境间长期的相对平衡,中断了生物演化的连续进程,使得生物多样性大幅下降,极大地弱化了旧生物屏障,并迎来了中生代新的生物演化时代。但是,在经历了二叠纪末大灭绝后,生物界进入了很长的残存期,其延续时间长达约10Ma。残存期是大灭绝事件的后续,深深地打上了大灭绝的烙印,同时,它又是随后复苏期的先兆,生物在此艰难的过程中是如何度过的呢?它们又采用     

A new approach for the recovery of precious metals from solution and from leachates derived from electronic scrap

A new approach is described for the recovery of precious metals (PMs: Au, Pd and Ag) with >99% efficiency from aqueous solution utilising biogas produced during the aerobic growth of Klebsiella pneumoniae. Gold was recovered from electronic scrap leachate ( approximately 95%) by this method, with some selectivity against Cu. The recovered PM solids all contained metal and sulphur as determined by energy dispersive X-ray microanalysis (EDX). X-ray powder diffraction analysis (XRD) showed no crystalline metal sulphur compounds but a crystalline palladium amine was recorded. Silver was recovered as a sulphide (found by EDX), carbonate and oxide (found by XRD). EDX analysis of the Au-precipitate showed mainly gold and sulphur, with some metallic Au(0) detected by XRD. The gold compound was shock-sensitive; upon grinding it detonated to leave a sooty black deposit.     

患者投诉与服务补救措施选择及补救效果评价的关联研究

根据患者在遭遇医疗服务失误后是否有投诉行为将其分为投诉和不投诉2类患者。采用关键事件技术法对经历过医疗服务失误的187位患者进行调查,获得了438个关键行为,比较2类患者在期望的补救措施选择方面的差异;然后采用情景模拟实验法,比较这两类患者在服务失误前后、补救前后以及不同补救水平等情况下的满意度与重复就医意愿的差异。     

Maximum use of resources present in domestic “used water”

Environmental protection and the sustainable management of natural resources stand at the foreground of economic and technological activities worldwide. Current sewage technologies, however, deal with diluted wastes and do not focus on recovery and are therefore not sustainable. Here, the most promising methods available for the recovery of nutrients (nitrogen, phosphorus), organic material and energy from “used waters” are examined both at the decentralised and centralised level. Novel approaches for water processing, not implementing aerobic biological treatment as a core technology, are conceived and critically evaluated regarding efficiency, diffuse emissions and requisite costs. By implementing up-concentration of dilute wastewaters, the concentrated stream becomes suitable for the waste-to-energy strategy.     

Selectivity and depth of microbial plugging in Berea sandstone cores

Summary The depth of plugging by the in situ growth of either injected or indigenous microorganisms was investigated using Berea sandstone cores with pressure taps located along the length of the core. The continuous injection of aerobically prepared sucrose-mineral salts medium with 5% NaCl and 0.1% NaNO₃ resulted in large permeability reductions (70–98%). The plugging was localized at the inlet and outlet faces of the cores, and was attributed to microbial biomass production at the inlet face and biogas accumulation at the outlet face. Batch addition of aerobic medium resulted in more uniform permeability reduction along the core's length, but the magnitude of the permeability reduction was not as large (about 65%). The semi-continuous injection of oxygen-free medium resulted in a slower but a more uniform permeability reduction throughout the core compared to cores which received aerobically prepared medium. The selectivity of the process was investigated in a dual core system where two cores of 240 and 760 mdarcy permeability were connected parallel to each other without crossflow. Initially, about 85% of the total fluid flow passed through the high permeability core. After the addition ofBacillus species and medium, the flow pattern changed and about 85% of the total fluid passed through the low permeability core. These results show that the in situ growth of microorganisms can selectively plug high permeability zones and that control of the process may be achieved by alterations in the method of nutrient injection.     

Effects of biocide treatment and backflow pressure on the permeability of microbially fouled model cores

Summary Sintered glass bead cores were plugged until the permeability was reduced to 1% or less of the original permeability by the injection of a slime-producing bacterium isolated from produced water. Scanning electron microscopy of fractured core sections showed that the bacteria were predominantly located in the uppermost sections, around the core inlet. Killing the bacterial cells in the plugging biofilm, using a biocide, had little effect on core permeability. The dead cells were only removed when backflow pressure, simulated by inversion of the test core followed by fluid injection, was applied and maintained at 55–69 kPa. Backflow of plugged cores containing live bacteria produced transient pressure-dependent increases in permeability that were proportional to the backflow pressure applied. We conclude that only sustained backflow procedures reduced permeability: such operations are not effective for oil recovery in field conditions.     

麻醉恢复室患者全麻苏醒期躁动的影响因素及与术后认知功能障碍的关系研究

摘要 目的：探讨麻醉恢复室患者全麻苏醒期躁动（EA）的影响因素及与术后认知功能障碍（POCD）的关系。方法：选取2018年7月~2020年6月期间我院收治的100例麻醉恢复室患者,采用Riker镇静-躁动评分标准评估患者EA,采用本院自制问卷调查量表统计患者一般资料,采用蒙特利尔认知评估（MocA）量表评估研究对象的认知功能,应用多因素非条件Logistic回归分析EA患者的影响因素,观察EA与POCD的关系。结果：100例麻醉恢复室患者中,EA的发生率为13.00%（13/100）,其中发生EA的患者纳为躁动组（n=13）,未发生EA的患者纳为安静组（n=87）。POCD的发生率为38.00%（38/100）,其中发生POCD的患者纳为POCD组（n=38）,未发生POCD的患者纳为非POCD组（n=62）。单因素分析结果显示,EA的发生与年龄、性别、吸烟史、嗜酒史、术中补液、放置导尿管时间、ASA分级、术后镇痛、麻醉恢复室停留时间等因素有关（P<0.05）,而与麻醉风险等级、麻醉方式、术后血小板、术后白蛋白等因素无关（P>0.05）。多因素非条件Logistic回归分析结果显示男性、年龄≥60岁、ASA分级为III级、术后无镇痛、诱导后放置导尿管为EA发生的危险因素（P<0.05）。POCD组患者EA的发生率高于非POCD组（P<0.05）。结论：EA的发生与多种因素有关,临床应对年龄≥60岁、ASA分级为III级、术后无镇痛、诱导后放置导尿管等因素予以关注并适当干预,同时POCD与EA的发生具有一定的关系。     

Key elements in achieving a successful recovery programme: A discussion illustrated by the Gould's Petrel case study

Summary   Surprisingly few faunal taxa worldwide have experienced an improvement in conservation status through direct conservation action. One of the few is Gould's Petrel ( Pterodroma leucoptera leucoptera ) – a threatened species that breeds only in New South Wales. In the early 1990s, the breeding population of this subspecies was small (<250 pairs) and declining. Each year, adult mortality at the breeding grounds exceeded the number of young produced. A recovery programme, focused on reducing adult mortality, commenced in 1993. As a result of the recovery actions undertaken, the Gould's Petrel is now increasing in numbers. Also, the rainforest where this seabird breeds is now regenerating after being degraded for almost a century by the introduced European Rabbit ( Oryctolagus cuniculus ). The creation of artificial nesting habitat and the development of effective translocation procedures have led to the establishment of a second breeding colony of Gould's Petrel, further reducing the risk of extinction.
In this paper, we explore the key elements we believe to be responsible for the success of this particular recovery programme: (i) a strong underpinning of robust ecological research; (ii) adaptive management; (iii) monitoring and reporting; (iv) a multidisciplinary approach; and (v) a willingness to accept risk. We conclude with some suggestions to improve the current recovery planning process.     

Resource and energy recovery options for fermentation industry residuals

Over the last 40 years, the fermentation industry has provided facility planners, plant operators and environmental engineers with a wide range of residuals management challenges and resource/energy recovery opportunities. In response, the industry has helped pioneer the use of a number of innovative resource and energy recovery technologies. Production of animal feed supplements, composts, fertilizers, soil amendments, commercial baking additives and microbial protein materials have all been detailed in the literature. In many such cases, recovery of by-products significantly reduces the need for treatment and disposal facilities. Stable, reliable anaerobic biological treatment processes have also been developed to recovery significant amounts of energy in the form of methane gas. Alternatively, dewatered or condensed organic fermentation industry residuals have been used as fuels for incineration-based energy recovery systems. The sale or use of recovered by-products and/or energy can be used to offset required processing costs and provide a technically and environmentally viable alternative to traditional treatment and disposal strategies. This review examines resource recovery options currently used or proposed for fermentation industry residuals and the conditions necessary for their successful application.     

The vision of recovery today: what it is and what it means for services

In the past, practice in mental health was guided by the belief that individuals with serious mental illnesses do not recover. The course of their illness was either seen pessimistically, as deteriorative, or optimistically, as a maintenance course. Research over the past thirty to forty years has indicted that belief and shown that a vision of recovery can be achieved for many individuals. People with serious mental illnesses have themselves published accounts of their own recovery as well as advocated for the development of recovery promoting services. In North America and other regions, policies have been developed to make recovery the guiding vision of services. Today, particularly in the United States, much effort is going into the transformation of services and systems to achieve recovery outcomes. Despite these trends, the idea of recovery remains controversial and, some say, even illusory. This article clarifies the meaning of the term "recovery", reviews the research and first person accounts providing a rationale for recovery, and sets out implications for developing recovery oriented services.     

简便实用的琼脂糖凝胶回收DNA片段方法

介绍一种简便实用的DNA片段回收方法,与以前所报道的DEAE-纤维素膜电泳法、透析袋电洗脱法、低融点琼脂糖凝胶法、凝胶冻融法等相比,所需器材简单、操作简便、回收率高、成本低。回收的DNA片段在进一步克隆和测序中表现出较好的效果,是一种适合于科研和教学的实验方法。