“整合物种概念”和“分化路上的物种”

已有的各个物种概念对物种的认识类似盲人摸象, 只包含了物种的某一个方面; 而一个分化后期的成熟物种应涵盖了所有的物种概念。但是, 尚未到达分化后期的物种往往又已开始新一轮的物种分化; 自然中存在的多数“物种”处于分化路上。这种循环往复连续分化产生的物种, 存在种间生殖隔离不彻底、基因流频繁发生、网状进化突出等现象。此外, 对于不同的物种对, 最早开始分化的基因以及不同物种概念所要求的条件的分化顺序不是统一的, 而是随机的。定义一个适合所有“分化路上的物种”概念存在较大困难。但是, 应采用尽可能多的物种概念来界定分化路上的物种、发表新种和进行分类处理; 也应承认种间可能广泛存在不完全的生殖隔离和有限的基因流, 即有不属于两个物种群体的杂交或回交个体的存在。这样划分的物种比只依据一个物种概念认定的物种具有更高的客观性和科学性。     

Modelling canopy CO2 fluxes: are ‘big‐leaf’ simplifications justified?

• 1 The ‘big‐leaf’ approach to calculating the carbon balance of plant canopies is evaluated for inclusion in the ETEMA model framework. This approach assumes that canopy carbon fluxes have the same relative responses to the environment as any single leaf, and that the scaling from leaf to canopy is therefore linear.
• 2 A series of model simulations was performed with two models of leaf photosynthesis, three distributions of canopy nitrogen, and two levels of canopy radiation detail. Leaf‐ and canopy‐level responses to light and nitrogen, both as instantaneous rates and daily integrals, are presented.
• 3 Observed leaf nitrogen contents of unshaded leaves are over 40% lower than the big‐leaf approach requires. Scaling from these leaves to the canopy using the big‐leaf approach may underestimate canopy photosynthesis by ~20%. A leaf photosynthesis model that treats within‐leaf light extinction displays characteristics that contradict the big‐leaf theory. Observed distributions of canopy nitrogen are closer to those required to optimize this model than the homogeneous model used in the big‐leaf approach.
• 4 It is theoretically consistent to use the big‐leaf approach with the homogeneous photosynthesis model to estimate canopy carbon fluxes if canopy nitrogen and leaf area are known and if the distribution of nitrogen is assumed optimal. However, real nitrogen profiles are not optimal for this photosynthesis model, and caution is necessary in using the big‐leaf approach to scale satellite estimates of leaf physiology to canopies. Accurate prediction of canopy carbon fluxes requires canopy nitrogen, leaf area, declining nitrogen with canopy depth, the heterogeneous model of leaf photosynthesis and the separation of sunlit and shaded leaves. The exact nitrogen profile is not critical, but realistic distributions can be predicted using a simple model of canopy nitrogen allocation.

     

“How pendulum‐like are siamangs? energy exchange during brachiation”

Hylobatidae (gibbons and siamangs) are known for their brachiation skills. The comparison of brachiation with a pendulum is made several times in the literature, and the costs and benefits of being pendulum-like are well described. However, the amount of energy exchange during brachiation of gibbons has rarely been determined. In this study, the amount of energy recovery (ER) during brachiation is assessed for three siamangs in a seminatural environment. The animals were recorded by four cameras while voluntarily brachiating on three different setups. The effects of locomotion speed, brachiation type, and setup on ER as well as on the external mechanical work during brachiation are determined. It is hypothesized that the amount of ER decreases with an increasing setup complexity while the external mechanical work increases. Additionally, we expect that support arm kinematics will be adjusted according to spatial complexity in order to maintain high recovery percentages. Our results show that ER is mainly determined by brachiation speed. Regardless of type of brachiation or setup, brachiation is done with a lower ER when brachiating faster. Within our limited range of setup variation, the expected effect of increasing complexity is not found. Although there is significant variation in support arm joint angles, no clear relation with speed, brachiation type, or setup is observed.     

“地衣”词考

本文考证了中国先秦时期到清末古籍中对“地衣”的解释;其中有共生学意义的“地衣”一词,是在清代李善兰的《植物学》一书中被提出的。     

Territoriality in Lake Eyre Dragons Ctenophorus maculosus: are Males ‘Superterritorial’?

The Australian Lake Eyre dragon, Ctenophorus maculosus, lives on dry salt lakes in the Australian interior. An unusual characteristic of this habitat is that windblown insects are the major food resource, which makes it impossible for males to defend site-related resources. Male territory size is not correlated to male size; thus, males do not seem to defend trophic territories in relation to their own energy demands. Instead, males with higher densities of lookout sites have larger territories, and males with larger territories have more mates. In consequence, males primarily seem to guard sexual resources on territories that are not economically defensible from a trophic point of view; males appear to conform to the concept of ‘superterritoriality’ (sensu Stamps 1983).     

新医学是解决人类健康问题的真正钥匙——需“精准”理解奥巴马的“精准医学计划”

2015年年初,美国总统奥巴马在国情咨文中提出了一个预算2.15亿美元的“精准医学计划”,希望以此“引领一个医学时代”。新闻一经发布,“精准医学”立刻成为了媒体和百姓嘴边的热词,受此影响国内亦有不少人士纷纷为美国总统的这一计划点“赞”。有人用“医学革命”来形容它,有人用“开创性”来抬高它,还有一个传闻,受奥巴马“精准医学计划”的影响,中国将在15年内投入600亿元人民币启动并发展中国版的“精准医学计划”。对此,有人提出了质疑,美国版精准医学计划是否符合中国国情?是否存在“水土不服”的可能?直接套用美国总统的智慧能否解决具有中国特色的实际问题?争论由此引发一个让人思考的问题,究竟什么才是现代医学的核心?在盲目堆钱的行动前,我们确实有必要从科学和临床应用的角度来探讨和思考一下现代医学的发展方向。 为了能“精准”地看到问题的实质,我将从当下时髦并且相关的词汇谈起,通过梳理,期待找出解决人类健康问题的真正钥匙。     

香菇‘申香1644’的选育报告

香菇‘申香1644’是以传统优质栽培品种‘申香215’为亲本,采用多孢自交育种技术选育的新品种。其菌盖纵切面呈凸形,菌盖直径(6.15±0.38) cm,菌盖厚度(2.27±0.42) cm,菇型圆整,菇质紧实,产量高,生物学转化率95%以上。与亲本相比,‘申香1644’在分子标记和栽培性状上均具有明显差异性,其菌盖为浅黄褐色,颜色较亲本浅;菌龄100-105 d,较亲本缩短5-10 d。‘申香1644’菌丝生长适宜温度为22-26 ℃,原基发育适宜温度为16-22 ℃,可在全国范围内进行代料栽培。     

Vocal Plasticity – are Pied Flycatchers,Ficedula Hypoleuca,Open‐Ended Learners?

In some songbird species, large song repertoires are advantageous in female attraction, whereas song sharing with neighbours may give an advantage in male–male competition. Open‐ended learners, with the ability to memorize new song elements throughout their lives, may learn from territorial neighbours and thus benefit from increasing both repertoire size and song sharing. A distinction needs to be made between true adult song learning, i.e. memorization of novel song elements, and vocal plasticity resulting in changes in the use of previously memorized elements, such as the use of hidden repertoires or increased production of previously rare syllable types. We assessed the ability of adult pied flycatcher Ficedula hypoleuca males to learn previously unheard song elements and to change their song production in response to playback of unfamiliar, conspecific song, emulating a singing neighbour. After a 1‐week playback treatment, three out of 20 subjects had learned foreign song elements, providing evidence from the wild that pied flycatchers are true open‐ended learners. However, the syllable sharing with the playback stimulus repertoires had not changed, and the males’ repertoires had decreased rather than increased. Hence, we did not find support for increased syllable sharing with neighbours or increased repertoire size as functions of adult song learning in pied flycatchers. Because pied flycatcher song seems to serve mainly for mate attraction, copying of attractive syllable types is a possible alternative function of adult song learning in this species.     

Is (9Z)‐“meso”‐zeaxanthin optically active?

The question raised in the title was answered. (3R, 3'S)-meso-Zeaxanthin was submitted to iodine catalyzed photochemical stereoisomerisation. The enantiomeric (9Z) and (9'Z) geometrical isomers were isolated by semipreparative HPLC and separated as diastereomeric dicarbamates on a chiral column only. Cleavage of the carbamate could not be effected. CD-Spectra of (1"S, 1"S)- and (1"R, 1"R)-dicarbamates of geometrical isomers of (3R, 3'R)- and (3R, 3'S)-meso-zeaxanthin were systematically studied and the contribution from the carbamate moieties revealed. It was concluded that (9Z, 3R, 3'S)-"meso"-zeaxanthin, in spite of having no symmetry elements, is optically inactive. The result has been rationalised in line with the current hypothesis on the origin of carotenoid CD spectra.     

Mammals,agri‐environment schemes and set‐aside – what are the putative benefits?

• 1 The impacts of agricultural intensification on farmland wildlife have been the subject of increasing concern, particularly over the last two decades. Population declines have occurred for a number of mammalian species, sometimes drastically so, and changes in farming practice are believed to be significant contributory factors.
• 2 The major policy instruments for delivering environmental benefits on farmland are agri‐environment schemes. These encourage farmers to adopt more environmentally sensitive farming practices to promote farmland biodiversity. Additionally, compulsory set‐aside, which reduces agricultural surplus, could also have positive impacts on wildlife. In this paper we consider some of the putative benefits of agri‐environment schemes and set‐aside for mammals.
• 3 We review how establishment and management options within agri‐environment schemes and set‐aside might affect habitat resources for mammals. For example, conservation headlands increase plant and invertebrate resources within the crop edge for mammals such as wood mice. Grassy field margins can support communities of smaller mammals, and hedgerows may act as important commuting and hunting routes. Their potential will depend on factors such as seed mixtures used, timing and severity of cutting, and length of time they have been in place.
• 4 At a farm level, habitat heterogeneity may be increased through organic agriculture, which is supported by some agri‐environment schemes. Studies suggest significant benefits to mammals, including wood mice and bats. However, it is increasingly recognized that effective conservation of farmland mammals must seek solutions at the landscape scale, addressing such issues as habitat connectivity between farms. One approach may be the better targeting of scheme agreements.
• 5 We suggest that agri‐environment schemes and set‐aside can contribute to the conservation of mammals on farmland. Recent policy changes are likely to have further positive impacts on farmland wildlife but appropriate mammal monitoring programmes must be developed rigorously to assess their effects.

     

“超级真菌”耳念珠菌研究进展

耳念珠菌Candida auris也被称为“超级真菌”,是近年来出现的一种人体病原真菌新物种,临床分离株通常具有多重耐药和高致死率等特征。2009年日本首次报道耳念珠菌之后,其感染病例在多个国家呈现出爆发式增长。目前已报道的病例分布在全球五大洲27个国家,包括中国。耳念珠菌感染给临床诊断和防控以及人类健康带来了巨大的挑战。本文从该菌临床分离菌株的生物学、遗传变异分化及耐药特征等方面入手,围绕分子流行病学、基因组特征、毒性因子和耐药性等方面系统地综述了近年来国内外取得的相关进展,并探讨了我国耳念珠菌感染的诊断、治疗和预防的措施。     

“瑞草”灵芝之现代研究

"灵芝"一词最早出现于东汉,人们"以为瑞草,服之神仙",称之为"灵芝"。现指隶属于真菌界Fungi、担子菌门Basidiomycota、伞菌纲Agaricomycetes、多孔菌目Polyporales、灵芝科Ganodermataceae的一类传统药用真菌的统称,具有免疫调节、抗肿瘤、抗氧化、抑菌、保肝护肝、止咳平喘等多种功效(林志彬2015;Gilletal.2016;Ahmad2018;Wuetal.     

香菇‘豫香2号’的选育报告

‘豫香2号’是从河南省卢氏县伏牛山地区采集的野生香菇子实体,经过多次组织分离和驯化等系统选育而获得的优良品种,适宜河南省中高海拔区域种植。该品种子实体中等,多单生,菌盖圆整、浅褐色,菌柄呈倒圆锥形,产量高,鲜销耐储存。     

黑木耳‘高原云耳2号’的选育

‘高原云耳2号’由采自云南省普洱市景东县哀牢山的一株野生黑木耳多次分离和反复驯化,通过连续6年的系统选育、评价筛选而育成。该品种为中早熟、广温广适型新品种。子实体多单生,小口出耳单片率高,耳片厚、大小适中、边缘圆整、质地硬脆,背面青灰至灰黑色、腹面黑色、有光泽,耳脉少,平均产量55-65g/袋,商品性佳,抗性强。适于1 500-2 200m高海拔地区立体袋栽。