The B.U.F. and anti-Semitism : (an exposure)
Fouilles et recherches nouvelles sur les travaux de César devant Alésia (1991-1994) = Neue Ausgrabungen und Forschungen zu den Belagerungswerken Caesars um Alesia (1991-1994) / mit einem Beitrag von Susanne Sievers
Siegmar von Schnurbein
Simulium feeding upon Chrysalids
Hermann August Hagen
The single self: feminist thought and the marriage market in early modern Venice
Taxonomical study of oribatid mites from Taiwan (Acarina: Astigmata) (I)
- This study treats 76 species, in which 58 species and 14 genera are described as new. The species are arranged in 28 families and 56 genera. The oribatid or cryptostigmatid mites are cosmopolitan group of more than 6500 species relegated to approximate 700 genera and 134 families. The body length of most oribatid species ranges 300-1200 μ. The oribatid mites are darkly coloured and covered with a rigid exoskelecton. The life cycle consists of egg, larva, protonymph, tritonymph, deutonymph and adult. These mites are best known as inhabitants of litter and upper soil strata, their small size and shunning of light caused them to receive little attention for many years. In recently studies of soil fauna, it has been shown that is an economic importance for human, i.e. many species feed on surface plant detritus, and may therefore play a major role in maintaining the fertility of soils; they could become an indicator of soil physical and chemical characters. Some species have also been shown to act as vectors of various tapewonns; they feed almost exclusively on tyroglyphid mites and attack the parasitic hymenopteran, Polynotus zosini; and several species are associated with plant, they have been reported to damage the leaf, the foot and the stem of potato, strawberry, turlip, citrus and mushroom. Systematic studies of these mites are scarcely found in Taiwan. The present paper deals with 76 species, 56 genera in 28 families, among them, 58 species and 14 genera are described as new. The author hopes that this study constitutes an example to show that the wealth of fascinating information could be gained and also hopes that this finding might be useful for elucidating the taxonomy of oribatid mites in Taiwan.
A multispecies extension to the Beverton and Holt theory of fishing, with accounts of phosphorus circulation and primary production
Knud Peter Andersen
- Interaction between species in a marine ecosy stem is described by expressions for food consumption and grazing mortality which are consistent with each other and with the Beverlon and Holt model of the population dynamics ofindividual species. A model of primary production is introduced in order to make possible an account of nutricnt circlliation (as examplified by phosphorus) within and nutrient flow through the system. It is demonstrated in an application to North Sea fishencs that recent changes in total yield can be described in some detail under the terms of the model as a function of fishing mortality alone. The composition of the North Sea fauna in the virgin state is discussed and also the conditions under which total yield could be increased above the 1970 level.
Techniques for collecting, handling, preparing, storing and examining small molluscan specimens
Daniel L. Geiger
Bruce A. Marshall
Winston F. Ponder
- Micromolluscs are small-sized molluscs (< 5 mm), and include the great majority of undescribed molluscan taxa. Such species require special collecting, sorting and handling techniques and different storage requirements to those routinely used for larger specimens. Similarly, the preparation of shells, opercula, radulae and animals poses some challenges for scanning electron microscopy (SEM). An overview of experiences with various techniques is presented, both positive and negative. Issues discussed include those relating to storage of dry specimens and interaction of specimens with glass, gelatine and paper products, handling techniques and storage in various fluids. Techniques for cleaning shells for SEM are described and compared, as well as those for radular extraction. The interactions of chemicals used for the dissolution of tissue with calcareous micromolluscs are described. Methods for handling and mounting small radulae for SEM are detailed and brief guides to SEM and light photography are given. An appendix listing details of frequently-used chemicals is provided. Key words: Review, methodology, collection, preservation, storage, museology, SEM, radula, shell. Byne's disease
Multicriteria evaluation in a fuzzy environment : theory and applications in ecological economics ; Part A theoretical analysis of cost-benefit analysis andmulticriteria evaluation
The nervous system of Nereis virens Sars : a study in comparative neurology
John I. Hamaker
- 1. The central nervous system of Nereis virens occupies a deeper position. than does that of most Polychaetes. It is separated from the hypodermis by the circular muscles, and is enveloped by an elaborate protective tissue. 2. The protective tissue consists of two parts jan inner spongy layer, the neuroglia, of ectodermic origin, and an outer sheath, the neurilemma, of mesodermic origin. 3. The" mushroom bodies" of insects and decapod Crustacea are represented in the brain of Nereis by the anterior masses of small nuclei. 4. The optic ganglion, which in some species of Nereis lies beneath the anterior eye, may in other species lie within the brain capsule. 5. There is no neuropil in the ventral nerve cord. 6. There are three longitudinal connectives between each two successive ganglia of the ventral nerve cord, one small median and two larger lateral ones. 7. The sheaths of the nerve fibres of the ventral cord have no nuclei, and hence must be a product of the fibres themselves. 8. The nerve cells of the ventral cord commonly have one or more centrosomes. 9. The giant fibres are nervous in function, and are put into relation with peripheral organs through ordinary centrifugal fibres. 10. The giant fibres give off no fibrillations, and nervous relation with other fibres is established directly between the axis cylinders. 11. Certain decussating fibres are always united in pairs by anastomoses between the axis cylinders where they cross each other. 12. Certain centripetal fibres of the same set are always united by anastomoses between the ends of the branches. 13. Contact between axis cylinders may possibly be one of the means of bringing nerve fibres into functionall'elation with each other.
Degradation of pine forest Vaccinio myrtilli-Pinetum vegetation under the influence of zinc and lead smelter
- This paper describes the effect of the "Boleslaw" mining and metallurgic complex in Bukowno near Olkusz on the vegetation of the fresh coniferous forest association Vaccinia myrtilli-Pineitum. The increase in concentration of zinc, lead and cadmium in selected plant species under the influence of industrial emission, and the dependence of this increase upon the magnitude of dust fall and site conditions, are analized. The extent of accumulation of heavy metals in plants was assumed to be an indicator of the degree of pressure exerted by the industrial complex. The degradation of fresh coniferous forest was. increasing along with an increase in this pressure. The species composition of the association, and the quantitative relations among species representing various site types underwent considerable changes. In patches extremely degraded, the plant species characteristic of poor sandy grass-lands gained predominance over forest plants.