Manioc—A tropical staff of life

A plant which in one form contains deadly prussic acid and in other forms nourishes thousands of primitive people and furnishes tapioca to modern man. *** DIRECT SUPPORT *** A02QO001 00002     

The Concept of Morphological Polarity and its Implication on the Concept of the Essential Organs and on the Concept of the Organisation Type of the Dicotyledonous Plant

Dicotyledons are polarly organised in several ways. In plant morphology polarity, a principle allowing comparison of different plant structures has until yet not been studied. A division** of the vegetative plant in shoot and root as polar structures leads to the distinction of four instead of three basic organs: leaf, shoot axis, root axis and root cap together with the root hairs. The flower is also polarly organised, its poles are formed by the carpels and the stamens. The foliage leaves are also polarly organised which is reflected by the morphological relationship of foliage leaf, stamen and carpel. The stamen uses the hypophyll*** as base of construction and the carpel uses the epiphyll**** as base of construction. Hypophyll and epiphyll are the two poles of the foliage leaf. Root and shoot, the polar entities of the vegetative plant and stamen and carpel, the polar entities of the generative plant, are morphologically correlated. Stamen and carpel can be understood as a combination of the basic organs of vegetative and generative parts of the plant. The basic organs of the generative plant are pollen grain and embryo sack with their gametophytes. The quantitative comparison of variable proportions is supplemented by a qualitative comparison of polarities. The result is, that the organisation type of the dicotyledons can yet be understood as constituted of morphological related parts.* in german Grundorgane** in german: Gliederung*** in german: Unterblat**** in german: Oberblatt     

Quantifying the community-level consequences of competition

Changes in plant community structure after changes in some aspect of the environment such as nutrients or grazing is often ascribed to changes in competitive relationships among the plants. However, very rarely is competition measured directly in such experiments. To distinguish between the direct effects of environmental treatments and changes in competitive relationships, it is necessary to quantify the influence of competition on community structure and compare the magnitude and direction of this influence between environments. We describe an experimental approach to accomplish this that is based on the classic yield-density experiment of agronomy. The approach is called the community-density experiment and requires experimental establishment of a gradient in total initial community density such that absolute densities of each species increase but initial relative abundances of each species stay constant along the gradient. We define various indices of the magnitude of community-level consequences of increasing density that can be compared among environments such as different fertilizer or grazing treatments. We also discuss various practical ways of achieving the experimental density gradient that are suitable for different kinds of communities. *** DIRECT SUPPORT *** A02DO006 00011     

Natural infections ofSisymbrium loeselii Jusl. with cabbage black ringspot and tobacco mosaic viruses

Investigating weeds for viruses in ruderal localities of Greater Prague two forms of mosaic diseases inSisymbrium loeselii Jusl. were demonstrated (green and yellowish-green mosaic). Transmission tests carried out on differential host plants showed that the green mosaic is caused by cabbage black ringspot virus (CBRV) and the yellowish green by mixed infection of CBRV and tobacco mosaic virus (TMV). TMV—isolate is characterized as an unusual necrotic strain; its capability to reproduce in cruciferous plant in nature is unique. It was ascertained that green mosaic was commonly spread overSisymbrium plants in ruderal ***DIRECT SUPPORT *** A01GP029 00004 associations on Prague territory; epidemiological significance of this discovery is discussed.     

Degradation of toluene/heptene mixtures in a trickling-bed bioreactor

Laws and regulations for the reduction of solvent emissions tend to force increasingly lower limits on gaseous emissions. Biological waste-gas treatment is an ecological and rather cheap method for solvent reduction, which is often used for waste-gas streams containing two or more components. The microbiological degradation of toluene and heptane as well as of several mixtures of these substances were investigated in a laboratory plant trickling-bed reactor. It was found that toluene was degraded at up to three times the rate for the heptane. Heptane elimination in the mixtures was low and the toluene elimination rate at low organic loads approached 100%. *** DIRECT SUPPORT *** AG903066 00010     

A newSalmonella type (S. Haarlem)

Summary A newSalmonella type (S. haarlem) with the antigenic formula 9,12: z: e,n,x, is described. *** DIRECT SUPPORT *** A1365006 00016     

Mould deterioration of feeding stuffs in relation to humidity of storage Part III. The isolation of mould species from feeding stuffs stored at different humidities

Isolations were made of mould species actively growing on a variety of feeding stuffs stored at fixed humidities between too and 65% for periods of up to 4 years. The factors influencing the species of moulds isolated were: (1) die relative humidity of the atmosphere; (2) the length of the storage period before the isolations were made; (3) the type and origin of die feeding stuffs from which the isolates were obtained.
A critical humidify existed for each species below which the development of mould spores could not take place. At relative humidities (R.H.) between 100 and 90% a large variety of moulds were able to develop. Members of die Mucorales and the Fungi Imperfecti were not isolated below 90% R.H. and, although ***Pemicillium app. flourished between 100 and 85% R.H., they were not isolated below 75% R.H. ***Aspergilhes app., on the other hand, were able to develop under conditions of very restricted moisture supply. Some members of the A. ***glaucus group were able to grow at humidities as low as 65-70%.
In general, the moat commonly occurring moulds on the feeding stuffs used in these trials were small ***ascospored species of the A. ***glaucus group, particularly A. ***repens and A. ruber. It is considered that it is these species that will most frequently cause mould damage to feeding stuffs in commercial stores.     

Variability in species richness and guild structure in two species-rich grasslands

It has been suggested that variation in the proportion of species in guilds (=guild proportionality) indicates community structuring by guilds in biotic communities. This hypothesis was tested on a subthermophilous grassland and a mesotrophic meadow at a scale of 0.09 m² based on a five-year data set. Further, variation in the total number of species, variation in the number of species belonging to a guild and non-randomness in species composition of guilds were studied. A number of criteria for guild definition were used, such as life form, Grime's C-S-R strategy, phenology, plant height, pollination and dispersal syndromes, leaf shape and anatomy and taxonomy at the family level. The observed variation in the number of guild species corresponded to the null model in which species assemblages with fixed species richness per square were randomly generated from the species pool. The observed variation in the number of guild species was often higher than the variation calculated for randomly distributed species whereas the variation in the proportion of guild species was in some cases lower than the variation calculated for randomly distributed species with fixed frequencies. Possible reasons for the discrepancy in the results based on different models are discussed. It is concluded that there is little evidence of guilds in the organization of grasslands. *** DIRECT SUPPORT *** A02DO006 00012     

A new species of Solanum subgenus Leptostemonum (Solanaceae) from northeastern Mexico

Solanum citrinum from northeastern Mexico is described, figured and discussed. *** DIRECT SUPPORT *** A01CT119 00006     

A stringent role of F-actin in the ascogonial differentiation ofNeurospora crassa Fluffy mutant

Cytochalasin D, an inhibitor of actin polymerization, interferes with ascogonial differentiation in the fertilefluffy mutant ofNeurospora crassa. As the total level of actin and its mRNA remain unchanged, this suggests that it is in its microfilamentous form (F-form) that actin is stringently required for female differentiation. *** DIRECT SUPPORT *** A00EN042 00011     

Syntaxonomic typology of Greek habitats

A review of the vegetation of Greece, following the hierarchical system of four main syntaxonomic levels (association, alliance, order, class) is presented and the correspondence of the high-ranked syntaxa with the Habitat Types included in Annex I of the Directive 92/43/EEC has been prepared. The syntaxonomic list of the vegetation units of Greece (up to alliance level) is composed of 41 classes, 56 orders, and 91 alliances. Of the 226 Habitat Types listed in Annex I of Directive 92/43/EEC, 111 different Habitat Types are present in Greece, of which 26 are Priority Types. The establishment of a syntaxonomic typology for the Habitat Types recorded in Greece is essential for the sake of vegetation mapping and nature conservation. A habitat coding system, as applied in Spain, is proposed for Greece for mapping purposes. *** DIRECT SUPPORT *** A02DO015 00007     

Dependence of radiostrontium uptake by pea and lupin on the content of calcium in the nutrient solution

In lupin (Lupinus albus L.) and pea (Pisum sativum L., cv. Raman) it was shown that the uptake of⁸⁹Sr from Knop's nutrient solution is significantly increased from a solution with decreased calcium content (one tenth of the normal content) and is slightly decreased from a solution with higher calcium content (150% of the normal content). The calciphile pea absorbs approximately 50% more calcium than the calciphobe lupin, and accordingly 50% radiostrontium less. The pea plant more strongly blocks the translocation of radiostrontium from roots to overground parts, as is proved by the higher discrimination factor of pea (i.e. by the ratio of specific activities of mCi⁸⁹ Sr/g Ca of roots to overground parts). The presence of chlorine in the nutrient solution decreases the content of radiostrontium per gram of dry matter, both in pea and lupin. Radiostrontium is absorbed quickly by both species of plants and is autoradiographically detectable as early as 2 hours after the introduction of radiostrontium to the nutrient solution. *** DIRECT SUPPORT *** A01GP049 00004     

Specierum generisPilosellae Hill combinationes novae

Einige alpine, balkanische, mediterrane und kaukasische Arten der GattungHieracium werden in die GattungPilosella versetzt. Es werden 60 neue nomenklatorische Kombinationen vorgeschlagen. *** DIRECT SUPPORT *** A01DO021 00005     

Ivesia aperta var. canina (Rosaceae), new from California

A new variety,Ivesia aperta var.canina, is described from Dog Valley, Sierra County, Nevada. It differs from the typical variety and approachesI. sericoleuca in its larger, paler yellow petals; longer filaments and styles; and decumbent-ascending vs ascending-erect stems. *** DIRECT SUPPORT *** A01CT146 00004     

Environmental degradation and the ambiguous social role of science and technology

Conclusion Recent anxieties about the deterioration of the global environment have had the effect of intensifying the ambiguity that surrounds the social roles of scientists and engineers. This has happened not merely, as suggested at the outset, because the environmental crisis has made their roles more conspicuous. Nor is it merely because recent disasters have alerted us to new, or hitherto unrecognized, social consequences of using the latest science-based technologies. What also requires recognition is that ideas about the social role of modern science and engineering are embedded in, hence mediated by, larger views of the world. Within such American worldviews, moreover, the status of science and engineering is closely bound up with their perceived effect upon the environment.In the dominant culture, accordingly, the respect given to scientists and engineers is in large measure dependent on their ability to play the central role assigned to them in the historical narrative about progress. As the ostensible heroes of that popular story, they are expected to lead the way in realizing the promise of prosperity and general well-being. The environmental crisis surely has diminished the credibility of that story, thereby causing the social role of science and engineering to seem more dubious — more ambiguous. To be sure, the crisis also may have the effect, for very different reasons, of increasing the power and responsibility of organized science. But the late twentieth-century task of damage control cannot possibly elicit anything like the respect accorded to organized science by the earlier belief in progress.It also is important to recall, finally, that the narrative of progress itself has undergone a disillusioning transformation. The early Enlightenment version of the story depicted scientists and engineers working in the service of a social and political ideal that all people could share. But the later technocratic concept of progress, with its sterile instrumentalist notion of advancing the power of science-based technology as an end in itself, is far less likely to inspire trust. Its patent inadequacies have had the effect of enhancing the appeal, if only by contrast, of the seemingly anti-science ideologies of pastoralism and primitivism. All of which might be taken to suggest that if the scientific and engineering professions want to recover some of the respect and status they once had, they would be well advised to join with sympathetic humanists and social scientists in recuperating some of the idealism that the project of modern science formerly derived from its place within the ideology of progress. That might entail the sacrifice of their technocratic posture of neutrality, dissociating themselves from people and institutions responsible for environmental degradation, and their help in formulating a new concept — which is to say, new criteria — of progress to which they might commit themselves. A primary test of any proposed social policy under this new dispensation surely would be whether it would improve, or at a minimum protect, the life-enhancing capacities of the global ecosystem. *** DIRECT SUPPORT *** A8402064 00011 *** DIRECT SUPPORT *** A8402064 00012 *** DIRECT SUPPORT *** A8402064 00013     

Heterochrony in Silurian phacopid trilobites as suggested by the ontogeny of Acernaspis

New material of early growth stages of the Silurian (Llandovery) trilobite Acernaspis is described. Pre-adult ontogenetic stages of this genus closely resemble adults of the post-Llandovery genus ***Ananaspis. A heterochronic descent of Ananaspis from Acernaspis is proposed. ***Ananaspis is interpreted as pae-domorphic, having arisen largely through neoteny. Neotenic changes already appear in the lineage in the last Acernaspis species, and Ananaspis then underwent continuous ncotcnic change throughout its known Silurian history. ▭ Heterochrony, neoteny, Silurian, Trilobita, Phacopidae, Acernaspis. Ananaspis.     

Note on a case of nonlinear diffusion

When the functionQ in the equation ∇²c +Q(c) = 0 is positive and is of a specified kind, the equation admits of a centrally spherical solution such thatc is positive everywhere, tending to zero at infinity anddc/dr=0 atr=0. Physically this corresponds to a local concentration of the solute in an infinite medium without any membranes present. This result would indicate the possibility of the formation of spontaneous concentrations and non-uniformities in non-linear diffusion fields. Possible biological implications are mentioned. *** DIRECT SUPPORT *** A01E2041 00002     

Epinigericin toxicity towards Tetrahymena pyriformis GL; changes in cell volume and intracellular pH

A study of the toxicity of epinigericin, an antibiotic ionophor, towards the ciliate Tetrahymena pyriformis showed that this molecule stopped cell division, increased cell volume and led to a more basic intracellular pH. The action of epinigericin was probably linked to its function as an ionophor. The ionic selectivity of this molecule is still not known. The raising of the intracellular pH of ciliates by this antibiotic may be linked to its toxic action and its ion-transport mechanism in Tetrahymena. *** DIRECT SUPPORT *** AG903066 00009