Diversity of the growth patterns of Bacillus subtilis colonies on agar plates

Abstract A Bacillus subtilis strain showed a variety of colony growth patterns on agar plates. The bacterium grew to a fractal colony through the diffusion-limited aggregation process, a round colony reminiscent of the Eden model, a colony with a straight and densely branched structure similar to the dence branching, morphology, a colony spreading without any openings, and a colony with concentric rings, on plates with various agar and nutrient concentrations. The microstructures of these colonies were also characteristic and dynamic. The patterns of these bacterial colonies were thought to grow in relation to the diffusion of nutrient in the agar plate.     

A simple classification of the complex parts of vascular plants

Four operational morphological units are defined to characterize 'typical' stems, leaves, roots and hairS. Any complex part can be classified among these OMUs by a graphical representation or by a quadruplet suitable for computer-aided analyses. Thirty-nine examples are given, suggesting a continuous view of plant morphology.     

Cladistics and the comparative morphology of linyphiid spiders and their relatives (Araneae, Araneoidea, Linyphiidae)

This paper provides the first quantitative cladistic analysis of linyphiid morphology. Classical and novel homology hypotheses for a variety of character systems (male and female genitalia, somatic morphology, spinneret silk spigot morphology, etc.) are critically examined and studied within a phylogenetic context. Critical characters have been illustrated. A sample of linyphiid taxa (nine genera in four subfamilies), five species of Pimoa (Pimoidae), and two other araneoid families (Tetragnathidae and Araneidae, represented by Tetragnatha and Zygiella , respectively) were used to study the implications of the phylogeny of Pimoidae for the systematics of linyphiids. The phylogenetic relationships of these 16 exemplar taxa, as coded for the 47 characters studied, were analysed using numerical cladistic methods. In the preferred cladogram Pimoidae and Linyphiidae are sister groups, Stemonyphantinae are sister group to the remaining linyphiids, and Mynogleninae are sister group to the clade composed of Erigoninae plus Linyphiinae. These results agree with the relationships recently proposed by Wunderlich, except by finding erigonines as the sister group to linyphiines rather than to mynoglenines.     

Gynoecium and perianth inZanthoxylum s.l. (Rutaceae)

The question whether the uniseriate perianth ofZanthoxylum L. s. str. is homologous with the calyx or the corolla of taxa included inFagara, or of an independent origin, has been controversial for a long time, but the arguments mostly have remained theoretical. The present investigation of floral structures indicates that there are two different types of uniseriate perianth inZanthoxylum s. str. Therefore, this taxon does not represent a natural group and should be united withFagara asZanthoxylum s.l. The infrageneric taxonomy of this genus is still very ambiguous. It is shown that differences in indumentum, number of sepals and petals (5-4-3) resp. perianth segments (4–9), stamens (3–6), and free carpels (1–5) are of systematic relevance. Particularly important but so far neglected is carpel shape, where an acrostylous and an anacrostylous-basistylous type can be recognized. Stigmata of 2 or more carpels mostly fuse to form a compitum. 4–5-merous flowers with calyx and corolla, and acrostylous carpels are considered as plesiomorphic character states in the genus. On the basis of ± corresponding morphological and phytochemical progressions a working hypothesis about the relationships withinZanthoxylum s.l. is presented in graphical form (Fig. 9).Adapted from a lecture held at the 10th Symposion on Morphology, Anatomy, and Systematics in Göttingen, February 1991.     

Coccoid Helicobacter pylori Not Culturable In Vitro Reverts in Mice

An experimental rodent model was used to demonstrate the viability of the coccoid form of Helicobacter pylori. Concentrated suspensions were prepared for the two different morphologies: at 2 days incubation for the bacillary forms and at 20 days incubation for the “dormant” forms. The strains used for incubation were two fresh isolates from humans with duodenal ulceration, and two collection strains. Five hundred microliters of culture (OD₅₅₀ = 5 Mc Farland) of Helicobacter pylori with bacillary (2-5×10⁹ CFU/ml) and coccoid (0 CFU/ml) morphology were inoculated intragastrically in BALB/c mice. The gastric mucosa of the mice was colonized by Helicobacter pylori with the administration of fresh bacillary and coccoid cultures and not with the established cultures. Helicobacter pylori was isolated at 1 week after inoculation with the administration of fresh bacillary cultures, while fresh coccoid Helicobacter pylori was recovered in mice stomachs after 2 weeks of inoculation. After colonization, histopathologic changes occurred after 1 month from inoculation; all colonized mice showed a systemic antibody response to Helicobacter pylori. These results support the thesis of the viability of coccoid Helicobacter pylori non-culturable in vitro and confirm that concentrated bacterial suspensions are able to colonize and to produce gastric alterations in this suitable animal model.     

Systematic classification of Asian colobines

In order to study the differentiation of Asian colobines, fourteen variables were analysed in one way, on 123 skulls, includingRhinopithecus, Presbytis, Presbytiscus, Pygathrix, andNasalis with both cluster and differentiated functions tests. Information on paleoenvironment changes in China and South-East Asia since late Tertiary have been used to examine the influences of migratory habits and the distribution range in Asian colobines. The cladogram among different Asian colobines genera was made from the results of various analysis. Some new points or revisions were suggested: 1. Following the second migratory way, ancient species of Asian colobines perhaps passed through Xizang along the northern bank of Tethis sea and Heng-Duan Shan regions, across Yunnan into Vietnam, since the ancient continent between Yunnan and Xizang was already located in on eastern bank of Tethis sea. Thus, during the evolution, Asian colobines must have had two original centres, i.e. “Sundaland” and Heng-Duan Shan Chinese regions; 2. Pygatrix possesses a lot of cranial features more similar toPresbytiscus than toRhinopithecus. The small difference from the modification combinesPygatrix with other two genera as shown by Groves (1970), but it is better to putPygatrix andPresbytiscus together as one genus; 3.Nasalis (2n=48) may be the most primitive genus within Asian colobines. Some features shared withRhinopithecus, for example body size, terrestrial activities, limb proportion etc. ...seem to be considered as a common inheritance of symlesiomorphus characters; 4.Rhinopithecus, with reference to cranioface and cranium or to its origin, is a special genus of Asian colobine. It may represent the highest level of evolutionary position within various genera (Peng et al., 1985).     

中国蓼属植物花粉形态的研究

本文用光学显微镜和扫描电镜对国产44种2变种蓼属植物的花粉形态进行了观察。除了前人报道的31种外,其中15种为首次报道。本属花粉形态多类型,有球形、近球形、近扁球形、近长球形及长球形;从萌发孔来看,有三沟型、三孔沟型、散沟型及散孔形：外壁纹饰有颗粒-穿孔、微刺-穿孔、微刺-凹穴、细网状、皱块状及粗网状。根据这些特征将花粉划分为10种类型,其中西伯利亚蓼型(Sibir-icum-type)为本文首次提出。文中对本属的分类问题进行了探讨,不支持Steward(1930)将本属划分为8个组的意见,而认为应将本属划分为11个组。     

Planning oral health care for the elderly in Israel for the years 2000 and 2025

The methodology and conclusions of this workshop arc reported here because the problems requiring solution are not unique to Israel. They will increasingly have wide geographical and political application. The population of Israel since its establishment in 1948 has increased about sixfold. The numbers of the elderly (65+) have increased about tenfold. The current situation must be examined and estimates obtained for the next ten years. Only thus can the system be enabled to cope with the problem as it develops. The chosen method was a carefully preplanned, multisectorial workshop. Recommendations were discussed, amended and finalised. The recommendations of the workshop included: Baseline national data is urgently required. Guidelines are required for selecting specific target populations to which priority should be given. The current favourable situation of adequate oral health manpower in Israel makes it possible to encourage providers of oral health care towards treatment for the elderly. It is essential that the appropriate health authorities allocate sufficient funds for the following urgent purposes: the conduct of a national survey of the elderly population; the establishment of oral health units on a trial basis in some selected hospitals; support institutions of higher education to facilitate training in geriatric dentistry. Conclusions. The workshop was multidisciplinary because it was necessary to include all the expertise and experience available as vital elements of the policy making process. This type of workshop was found to be an effective tool for planning oral health services.     

大血藤科植物的分类学研究

作者对大血藤科植物的花性、叶片内部结构形态、花粉形态、染色体核型及过氧化物酶和脂酶同工酶进行了比较研究,结果表明：１）大血藤科植物外形上的两性花,其雄蕊的形态退化、花药始终不开裂,为功能上的雌花,因此其花为单性,同株,同序或异序;１２）首次指出大血藤属植物的染色体数为２ｎ＝２ｘ＝２２,属小型染色体,与木通科植物２ｎ＝２ｘ＝３２、３０、２８的染色体数明显不同,支持Ｓｔａｐｆ（１９２６）将其从木通科分出另立为科的观点;３）单叶和复叶可出现于同一植株上,而且在叶片内部结构、花粉形态、染色体核型、过氧化物酶及脂酶同工酶等性状上,大血藤与单叶血滕间均无实质性的差异,因此将单叶血藤归并于大血藤中。