北极生命：神秘的绚彩乐章

北极圈以北的陆地上，只有草原，极少树木，即所谓的苔原带。每逢严酷的冬日，冰雪覆盖，天寒地冻，暴风肆虐，生灵隐形，看上去似乎没有一点生命的迹象。然而，夏天一到，冰消雪融，太阳不落，万物苏醒，草绿花香，鹿奔鸟鸣，显出了无穷的生机与活力。若从飞机上看下去，更是蔚为壮观，一会儿是峰峦起伏，崎岖连绵，犹如梯田万亩；一会儿是绿色茵茵，沟壑交错，仿佛是     

金叶国槐选育记

１９９６年的春季，笔者在苗圃当年播种的国槐实生苗中，发现一株叶片金黄发亮，十分特异，就做了标记，继续观察。到了夏季，标记苗依然金黄鲜艳，生机勃勃，在周围普通国槐的映衬下，显得十分醒目。为了进一步验证其稳定性，次年春天，取其枝条在国槐上进行了高接，嫁接枝条全部成活，萌发后依旧金黄鲜艳，且长势良好。此后几年又连续进行了嫁接，均性状稳定，长势良好，笔者初步给其定名为“金叶国槐”。金叶国槐叶子为奇数羽状复叶，叶片为卵形，比国槐叶片较舒展，平均长２５厘米，宽２厘米，从端部到顶部大小均匀，每个复叶有１７—…     

珍贵园林绿化树种—伯乐树

伯乐树(Bretschneidera sinensis)又名钟萼木，系伯乐树科惟一的种，我国特有的第三 纪孑遗植物，被列为国家一级重点保护植物。钟萼木冠大荫浓，树干通直，材质优良；其花 大型，总状花序顶生，初夏盛开时满树粉红如霞，格外引人注目；果实成熟时暗红色果实挂 满枝头，形如小仙桃，在绿叶的衬托下，十分耀眼，独具特色，具有很高的观赏价值，是优 良的园林观赏和绿化造林树种。伯乐树为落叶乔木，高达25米，胸径达1米。树皮灰色或青灰色，近平滑。小枝粗壮，暗 红褐色。奇数羽状复叶互生，大型；小叶7—15片，对生，薄革质，矩圆形、狭卵…     

西洋杜鹃的叶芽快速繁殖

西洋杜鹃是映山红的栽培变种，是栽培杜鹃中最美丽的一类，世界各地广泛栽培，园艺品种已达数千个。西洋杜鹃植株矮小，高仅50厘米，分枝细密，叶片小，花色艳丽，以鲜红、粉红为主，并镶有其它颜色的花边，极为优美，且四季都能开花，具有极高的盆栽观赏价值，是美化环境和居室的优良花卉品种。利用组培方法，可降低成本，加快其繁殖速度，在较短的时间内获得较多的无性系苗木。现将其快繁方法简述如下：以重瓣西洋杜鹃为材料，早春取新发幼芽，长约2厘米，用清水冲洗干净，在0．回叽升汞中灭菌5分钟，再用无菌水冲洗3－4次，取其叶芽接入…     

铺向大海的“红地毯”

在黄河三角洲广袤的土地上，8—9月份在泥质海岸近海处，都会看到一望无际的“红地毯”，其平坦如毡，色彩如画，这就是翅碱蓬群落。翅碱蓬(Suaeda heterotera)系藜科碱蓬属植物，一年生草本，株高20—80cm，茎直立粗壮，圆柱状浅绿色，有条楞，多分枝，枝细长，上升或斜伸；叶丝状条形，半圆柱状，通常长1—25cm，宽约1—2mm，灰绿色，光滑无毛，稍向上弯曲，先端尖或微钝，无柄，枝上部的叶较短；团伞花序，通常含3—5花，在分枝上排列成有间断的穗状花序；小苞片卵形，几全缘；花两性有时兼有雌性，花被半球形，底面平；裂片卵形，…     

蛇与气功

蛇与气功莫克蛇与气功，原是风马牛不相及，难道还有什么姻缘将它们摄合在一起吗？是的，请翻阅古代神话渊薮的《山海经》一书，里面有一条令人刮目相看的记述：“钟山之神，名曰烛阴，视为昼，瞑为夜，吹为冬，呼为夏，不饮，不食，不息，息为风，身长千里，其为物，人面...     

红腹锦鸡的越冬生态观察

保护区境内的红腹锦鸡栖息于海拔１０８０米－１８００米的落叶阔叶林和针阔混交林，冬季集群活动于巴山木竹林，农田，荒地，各群的大小和当年的繁殖成活率有关，集群时间和气温，降雪有关，繁殖成活率高，群内个体数量多；气温低，降雪早，集群开始早，三官庙，大古坪１６个群，各群的个体数，性比，在观察期逐年变化，日活动以觅食为主，占全天活动时间４０％以上，并在７：３０－１０：００、１６：００－１７：３０分别形成取食     

基于SWOT分析的食育发展战略研究

通过SWOT分析，探究国内食育发展的内在优势和劣势，剖析外在机会与威胁，在此基础上构建SWOT矩阵，并提出食育发展战略框架。第一，战略层面上，顶层设计、科学发展，统筹资源、合作发展；第二，目标层面上，营养导向、创新发展，文化传承、融合发展；第三，产业和区域层面上，产学研融合、联动发展，因地制宜、差异发展；第四，实施层面上，标准引领、规范发展，示范先行、有序发展。     

姹紫嫣红蒜香藤

蒜香藤 (Pseudocalymma alliaceum)又名蒜藤，紫葳科蒜藤属多年生常绿藤本花卉。原产于南美洲的圭亚那和巴西，华南植物园已有引种栽培。蒜香藤茎长 2— 4米，枝条披垂，绿色至灰白色，具肿大的节，单叶对生或复叶对生，叶柄木质，长 1— 2厘米，每一叶柄的顶端着生 2片小叶，长 8— 12厘米，宽 4— 6厘米，革质而具光泽，矩圆状卵形，先端渐尖，基部极偏斜，叶面较粗糙，全缘，叶面浓绿色，背面绿色，揉搓有蒜香味。在两枚小叶之间，常长出一条由顶生小叶演变而来的长长的卷须，能攀附其它物体向前生长，它也能散发蒜香味。蒜香藤的花多而…     

青龙肠溶胶囊治愈胃癌1例报告

青龙肠溶胶囊治愈胃癌１例报告山东省青州市人民医院冯德安，于晓燕，范秀田患者李刚顺，男，６０岁，因上腹不适，渐瘦月余于９４年１月２４日来诊。既往无胃病史，近一个多月来，渐感上腹胀疼，厌食乏力，服用多种胃药无效。查体：贫血貌，心肺正常，上腹肌张力略增强，...     

On the diversity of the Cladocera in the tropics

The mythical concept of an impoverished tropical cladoceran fauna is refuted. On a planetary scale, around half of the cladoceran species presently known occur exclusively in the tropics-subtropics, often with considerable restriction to particular geographical subzones. On a regional (political) scale, the situation is often unclear because of the continued fragmentary nature of studies, and because political units are not a good basis for biogeographical comparisons. At the finest level of resolution (lake-perlake comparisons), there appears to be an upper limit of c. 50 cladoceran species per individual lake. No significant difference between lakes in the temperate zone and in the tropics could be established here. Daphnia is largely absent from the tropics, but is replaced by more Sidids, Moinids, and Bosminids, such that the average cladoceran community in the limnetic zone of a tropical lake is not characterized by less species but rather by lower population densities. This, in turn, is considered a consequence of higher prevalent predation levels in the tropics.     

Characteristics of the membranes of the pellicle of the ciliatePseudomicrothorax dubius

Summary The membranes of the pellicle of the ciliatePseudomicrothorax dubius are investigated using thin section electron microscopy and freeze-fracture replicas. The plasma membrane is covered by a surface coat and is connected to the outer alveolar membrane by short, sometimes branched, bridges. The inner alveolar membrane is coated on both sides. The epiplasm lies in intimate contact with the cytoplasmic surface of this membrane, and there is a corresponding deposit on the other surface. This deposit is regularly striated.The epiplasmic layer and the alveoli are interrupted at sites of cytotic activity,e.g., the attachment sites of trichocysts, the cytoproct, and the parasomal sacs. The striated deposit ends where the epiplasm ends, indicating a direct relationship between these two epimembranous layers.There is a deposit along the sides of the first part of the tip of the trichocysts, and in this region the trichocyst membrane is free of intramembranous particles.The membrane of the parasomal sacs has a coat on both surfaces. That on the extraplasmic surface is similar to the surface coat of the plasma membrane. The origin of the cytoplasmic coat is unknown. The cytotic activity of these sacs is indicated by their highly irregular profiles.     

Ectogenesis and the case against the right to the death of the foetus

Ectogenesis, or the use of an artificial womb to allow a foetus to develop, will likely become a reality within a few decades, and could significantly affect the abortion debate. We first examine the implications for Judith Jarvis Thomson’s violinist analogy, which argues for a woman’s right to withdraw life support from the foetus and so terminate her pregnancy, even if the foetus is granted full moral status. We show that on Thomson’s reasoning, there is no right to the death of the foetus, and abortion is not permissible if ectogenesis is available, provided it is safe and inexpensive. This raises the question of whether there are persuasive reasons for the right to the death of the foetus that could be exercised in the context of ectogenesis. Eric Mathison and Jeremy Davis have examined several arguments for this right, doubting that it exists, while Joona Räsänen has recently criticized their reasoning. We respond to Räsänen’s analysis, concluding that his arguments are unsuccessful, and that there is no right to the death of the foetus in these circumstances.     

On the nature of the horny scales of the pangolin

The pangolin scale is a horny derivative of the epidermis. It is complex in structure and is divisible into three distinct regions. The dorsal plate forms approximately one-sixth of the scale thickness. It is composed of flattened solid keratinized cells without basophilic nuclear remnants. This region tends to fray easily. The dorsal plate contains bound phospholipids and sulphydryl groups but is weak in disulphide bonds.
The bulk of the scale is made up of the intermediate plate formed of less flattened cells without basophilic nuclei. This region is rich in disulphide bonds but contains no appreciable bound phospholipids or sulphydryl groups.
The ventral plate is only a few cells thick and is rich in bound phospholipids, which also occur in the underlying scale bed epidermis.
These three regions of the scale are formed from separate epidermal germinal areas which do not develop a granular layer. Keratohyalin granules are, however, formed in the epidermis between the scales.
It is suggested on the basis of histological structure and dishribution of chemical constituents that pangolin scales are probably homologous with primate nails.
Evidence against the views that they are homologous with reptilian scales or are derived from compressed hairs is presented.     

On the origin of the genetic code and the stability of the translation apparatus

An “error theory” is developed which can be applied to determine the stability of a macromolecular translation machinery which reproduces itself. It is shown that the overall effects of a multitude of possible error versions of macromolecules can be treated statistically, and that such a statistical approach is of considerable usefulness in the theoretical treatment of complex macromolecular systems. The theory is developed within the context of a detailed treatment of the “frozen accident” hypothesis for the origin of the genetic code. A model is described which permits some thermodynamic characterization of the components involved in the code nucleation. The model also proves useful in resolving a stability “paradox” described by Orgel, which relates to the translation stability in present-day organisms and mechanisms of ageing. It indicates that any experimentally found decrease in translation accuracy with age is probably not due to an inherent instability in the translation apparatus. Relevant experiments are suggested.     

Dissymmetry of the origins of the roots of the spinal cord in the dog

The spinal cord in 25 non-inbred dogs has been studied macro-microscopically. The dissymmetry in the arrangement level in the right and left root bases on the dorsal surface of the spinal cord is much greater than on the ventral surface. The same as in the human being, the dissymmetry is the greatest in the thoracic part (as compared to other spinal parts). On the ventral surface of the spinal cord both along the anterior and posterior margin of the root bases, there is a right-sided dissymmetry (with cranial shift); on the dorsal surface it is present only at the roots along the posterior margin. The dissymmetry of the dog spinal cord is quantitatively estimated along its whole extension.     

Tracking in the Wlds--the hunting of the SIRT and the luring of the Draper

Wallerian degeneration of distal axons after nerve injury is significantly delayed in the Wlds mutant mouse. The Wlds protein is a fusion of nicotinamide mononucleotide adenyltransferase-1 (Nmnat1), an essential enzyme in the biosynthesis pathway of nicotinamide adenine dinucleotide (NAD), with the N-terminal 70 amino acids of the Ube4b ubiquitination assembly factor. The mechanism of Wlds action is still enigmatic, although recent efforts suggest that it is indirect and requires sequences flanking or linking the two fused open reading frames. Three papers in this issue of Neuron now show that Wlds action is conserved in Drosophila and that a critical role of Wlds may be the suppression of axonal self-destruct signals that induce Draper-mediated clearance of damaged axons by glial cells.     

Second messengers involved in the muscarinic control of the heart: the role of the phosphoinositide response

Two heart muscarinic responses are compared, the reduction of cyclic AMP concentration and the hydrolysis of phosphoinositides. It is suggested that the former is more important physiologically, since the latter is a slow response requiring much higher agonist concentrations. Inositol trisphosphate released from phosphoinositides is unlikely to produce a positive inotropic effect by releasing calcium from the sarcoplasmic reticulum. However, long term muscarinic effects may involve activation of protein kinase C by diacylglycerol released from phosphoinositides.     

Contribution to the knowledge of the brain in the newborn

On 50 brains of newborns of either sex, the exterior and interior morphology was studied. The exterior morphology of the brain was conformable to the configuration of the skull. The insula is relatively large, but extremely inadequately grooved. The subcortical masses are well pronounced but there is in general a very slight difference between the white and gray matter of the brain. The convolutions and grooves of the cerebellum are very distinctly marked, the nucleus dentatus is large and white matter is prevalent. The brain stem is rather well formed, distinctly plastic, this being particularly true for the region of the rhomboid fossa and medulla oblongata.     

The orientation of the force of the jaw muscles and the length of the mandible in mammals

Ungulates generally have large masseter and pterygoid muscles and a necessarily large angular process provides attachment surface on the mandible. The temporalis muscle tends to be small. It has been suggested that this is an adaptation for enhanced control of the lower jaw and reduction of forces at the jaw joint. I suggest an additional reason: because of the geometry of the jaw, the length of that segment of the lower jaw that spans the distance from the jaw joint to the most posterior tooth is significantly reduced when the masseler and pterygoid are the dominant muscles; this region is necessarily much longer when the temporalis is large.