Length of burning rotation and community composition in high-level Calluna-Eriophorum bog in N England

Studies on a long-term experiment on Calluna-Eriophorum bog indicate that the length of time between management fires affects the post-fire development. A short rotation (every 10 years) results in increased dominance by Eriophorum spp. while a long rotation (every 20 years) results in greater abundance of Calluna vulgaris after fire. Variations in post-fires species abundances are related to pre-fire stand composition coupled with the patchy distribution of regeneration centers of rhizomatous species. The usefulness of burning this vegetation type in management for herbivore grazing is questioned.Nomenclature follows Tutin et al. (1964 80) for vascular plants. Smith (1978) for mosses, Watson (1981) for liverworts and Hawksworth, James & Coppins (1980) for lichens. Following common practice. Calluna vulgaris is referred to simply as Calluna. Acknowledgements. I thank M. Raves and the Nature Conservancy Council for permission to work on Moor House National Nature Reserve and for the use of data from Reserve Records, V. J. Hobbs for field assistance, and Prof. C. H. Gimingham for help and advice during the study. I also thank all who worked at Moor House for creating a pleasant working environment. The long-term experiment was planned by Dr R. J. Elliot and analyzed initially by Dr G. I. Forrest.     

Electron microscope studies on the structure of collagen fibrils by negative staining

Summary Electron microscope studies on collagen from rat-tail tendon using a negative staining technique have indicated the presence of filaments 15–20 Å in diameter within the fibres. These filaments are thought to correspond to the collagen macromolecule.We would like to thank Prof. R. A. McCance for supplying the specimens of fowl tendon used in this investigation, and Dr. F. H. C. Crick, Dr. S. Fitton-Jackson and Dr. T. Gillman for a number of valuable discussions. One of us (W. J. T.) wishes to thank the Medical Research Council for financial support during this work.     

Species ordering on a variance criterion

Summary A technique for ordering, to identify diagnostic species, based on variance ratios has been described. The method was illustrated with river terrace data.The author would like to thank Dr. László Orlóci for permission to use the vegetation data employed in the illustration of the algorithm. This work was supported by a grant from the National Research Council of Canada.     

Behavioural responses of the pine weevilHylobius abietis L. (Col.: Curculionidae) to odours activating different groups of receptor cells

Summary A method for measuring the attractive effect of odorous compounds on a population of pine weevilsHylobius abietis L. is described. Three substances, which strongly activated different groups of sensory cells (Mustaparta, 1975) were examined. Trans-verbenol, which excited selectively certain trichodeal cells had the highest attraction and dominated the attractive effect of -pinene. The latter activated a special group of basiconic cells which indicated its importance as food attractant. The third compound, 5-hexen-2-one, activated a large number of olfactory receptor cells, but had almost no attractive effect on the weevils.This work was financed by the Norwegian Research Council for Sciences and Humanities NAVF, and also supported by Deutsche Akademische Austauschdienst DAAD.I would like to thank Dr. S. Gothilf, Israel Institute for Biological Research, Tel Aviv, Dr. J. Jansen, Institute of Physiology, University of Oslo, and Dr. S. Grillner, Institute of Physiology, University of Gothenborg, for discussions. For constantly providing insects I am thankful to Oberforstmeister H. Niemeyer, Niedersächsische Forstliche Versuchsanstalt, Göttingen.     

Vegetation and soil studies of the enclosed heathlands of the Lizard Peninsula,Cornwall

Summary The heathland vegetation of the Lizard Peninsula, Cornwall, which had been formerly enclosed for agricultural purposes and allowed to revert to heathland, was compared with unenclosed areas. The enclosed vegetation tended to be more complex and intermediate between two of the main heath types found on the Lizard, Short and Tall Heath (sensu Coombe & Frost 1956a). The concentrations of exchangeable calcium, sodium and magnesium in the soils of the enclosed heaths were also intermediate between those of the two unenclosed vegetation types, whilst exchangeable potassium and total phosphorus concentrations were higher, perhaps a relic of past management. The enclosed heaths are therefore distinctive entities in their own right, although they are related to the unenclosed vegetation types. The relevance to healthland conservation on the Lizard Peninsula is discussed.Species nomenclature follows Clapham, Tutin & Warburg (1962) for higher plants and Watson (1968) for bryophytes.We would like to thank Drs. D.E. Coombe and L.C. Frost for considerable assistance throughout this work. Professor P. Bannister and Mr. M.O. Hill assisted with numerical analysis, and Dr. D.F. Chamberlain confirmed the identification of bryophytes. Professor A.D. Bradshaw kindly allowed one of us (R.H.M.) the facilities of his department to complete this work. N.E.R.C. are thanked for financial support.     

Staphylococcus aureus alpha-toxin-induced pores: Channel-like behavior in lipid bilayers and patch clamped cells

The conductance of pores induced by Staphylococcus aureus -toxin in Lettre cells has been compared to that in bilayers composed of synthetic lipids or Lettre cell membrane constituents. Previously described characteristics of toxin-induced conductance changes in lipid bilayers, namely rectification, voltage-dependent closure, and closure at low pH or in the presence of divalent cations (Menestrina, 1986) are displayed also in bilayers prepared from Lettre cell membranes and in patch clamped Lettre cells. It is concluded that endogenous proteins do not affect the properties of -toxininduced channels significantly and that the relative lack of ion channels in Lettre cells makes them ideal for studies of pore-forming toxins by the patch clamp technique.Dr. Sviderskaya is on leave of absence from the Physiology Institute, University of St. Petersburg, RussiaWe are grateful to Dr. J.P. Arbuthnott and Dr. K. Hungerer for gifts of S. aureus -toxin, to Dr. T.B. Bolton for collaboration with patch clamped cells and to Dr. J.M. Graham for help with the preparation of Lettre cell plasma membranes. This study was supported by the Cell Surface Research Fund, Medical Research Council, Science and Engineering Research Council, UNESCO (Molecular and Cell Biology Network) and The Wellcome Trust.     

Roll of the Botanical Society of Edinburgh

Summary

The succession of vascular plants and lichens along a 131m transect, representing 70 – 80 years accretion to a sand-dune system, was studied at Tentsmuir Point National Nature Reserve, Fife. Its flora is compared to other dune areas and the reasons why some such areas are lichen-rich and others lichen-poor are discussed.     

Grazing and mowing as management tools on dunes

A brief review of mowing and grazing of sand dune vegetation introduces the first results of the use of these management techniques at Newborough Warren National Nature Reserve, Anglesey, north Wales. In the mowing experiments, plots are mown one (May), twice (May and July), three times (May, July and September) and five times (May, June, July, August and September).The grazing experiment has the equivalent of one or two animals to three-quarter acre paddocks (0.3 ha) which are grazed for one third, two thirds or for the whole year.Mean numbers of species per plot, and Lotus corniculatus have increased in both sets of experiments whereas Arrhenatherum elatius has declined. Other species do not show clear-cut changes. Both methods provide practical means of maintaining a short turf, but the long-term effects of mowing may not be beneficial to the vascular plant flora. Grazing can however provide a crop as well as a desirable flora although manpower and capital costs may limit its use by conservationists.Nomenclature follows Clapham, A. R., Tutin, T. F. & Warburg, E. G. (1962), Flora of the British Isles, 2nd ed. Cambridge University Press, London.A large grazing experiment can not proceed without the help and advice of many people. The Nature Conservancy Council has allowed the establishment of the grazing and mowing experiments at Newborough Warren National Nature Reserve. The staff of the North Wales region of NCC have encouraged and aided the work in many ways. Mr W. D. Martin, Mr R. A. Bennett, Mr L. C. Colley and the Estate Workers merit special thanks. Dr J. Hodgson, late of the Grasslands Research Institute, now with the Hill Farming Research Organisation and Mr P. Rothery (ITE) gave useful, practical and statistical advice at the planning stages of the grazing experiment. Mr R. J. C. MacMullen assisted with the field survey in 1982 and preparation of the data for computer analysis. Dr D. Moss (ITE) has provided statistical advice and computations. Professor F. T. Last and Dr C. Milner, my senior officers in ITE, have been especially helpful with advice and encouragement.     

Vegetation responses to past climatic variation

Vegetation responses to climatic change can be studied retrospectively by utilizing the Quaternary fossil record. There has been controversy over the extent to which major changes in vegetation patterns at the continental scale lag behind the climatic changes that drive them, and to what extent vegetation can ever be said to be in equilibrium with climate. The equilibrium question has no single answer. The predominant mode of vegetation response to climatic change depends on the space and time frame and resolution of the data set in which the response is observed.Vegetation (as observed on particular space and time scales) can be in dynamic equilibrium with climate if its response time is sufficiently fast in relation to the rate of climatic change to which it is observed to be responding. Several processes can be involved in the response: successional, migrational, edaphic, and evolutionary. Successional response times can be deduced from forest succession models. The other processes are less well understood and different ideas exist concerning their rates. According to one hypothesis, migrational lags caused delays of thousands of years in the postglacial dynamics of forest composition. The alternative hypothesis explains these changes as dynamic equilibrium responses to changes in climatic seasonality and climatic anomaly patterns. Neither hypothesis need be universally true; gradient analysis and forest succession models are among the techniques that can be used in inferential tests of these hypotheses for particular space-time regions.Dynamic equilibrium may often be a reasonable approximation for the responses of the broadest continental-scale forest patterns to orbitally induced climatic changes. But as spatial and temporal frames of observation are diminished and resolution increased, biotic processes must eventually come to dominate. At sufficiently fine scales the main observable phenomena are successional responses to natural disturbance events. The late-Quaternary record of vegetation change allows a choice of observation scales and thus provides a continuum of possibilities for study, ranging from long-term dynamic bioclimatology to more conventional vegetation dynamics.I thank Margaret Davis, Honor Prentice, Jim Ritchie, Al Solomon, Geoff Spaulding and Tom Webb for their reviews of earlier drafts. Research supported by a US Department of Energy, Carbon Dioxide Research Division, grant to Brown University and a Swedish Natural Science Research Council grant to the project SlsSimulation of Natural Forest Dynamics.I thank Margaret Davis, Honor Prentice, Jim Ritchie, Al Solomon, Geoff Spaulding and Tom Webb for their reviews of earlier drafts. Research supported by a US Department of Energy, Carbon Dioxide Research Division, grant to Brown University and a Swedish Natural Science Research Council grant to the project SlsSimulation of Natural Forest Dynamics.     

Studies on the receptors in Ciona intestinalis

Summary A photoreceptor type structure not previously described has been found in the dorsal wall of the cerebral vesicle of the tadpole larva of Ciona intestinalis. The membranes of this receptor are organised as tubules some 60–100 nm in diameter and up to 1.5 m long. The tubules are confined in bundles about 1.5 m in diameter, which extend from the cell surface into the cavity of the cerebral vesicle. These tubules are similar to those in the rhabdomeric type of photoreceptor. However, in the cells from which the tubule processes arise are structures typical of the bases of cilia, and found in ciliary type photoreceptors.I should like to thank Professor J. Z. Young, F. R. S. for his continuing encouragement and help, and Dr. R. Bellairs for the use of electron microscope facilities. Mr. R. Moss and Mrs. J. Hamilton gave excellent technical assistance.     

The fine structure of the sense organs of the cephalopod mollusc Nautilus

Summary The structure of the rhinophore, digital tentacles, post-ocular tentacles and the eye of Nautilus macromphalus are described. The rhinophore is composed of mucous cells, ciliated cells, and flask-shaped ciliated cells. The latter are probably olfactory receptors. The digital tentacles are composed of mucous cells and pigmented cells. Motor-end-plates found in the muscle layer below the epithelium of the digital tentacles are similar to those described in other cephalopods. The post-ocular tentacle contains receptor cells that bear macrocilia. These may be mechanoreceptors. The retina is composed of retinula cells and supporting cells. A complex rhabdom is formed at the distal ends of the retinula cells. The supporting cells send processes up between these rhabdoms. Both types of cells contain pigment granules but the retinula cell has a complex membranous structure in its perikaryon. No synapses were found at the bases of the retinula cells. At the side of the retina are mucous cells that are presumed to produce the jelly-like substance that fills the inside of the eye in life. The likely function of the eye is discussed and it is suggested that it is capable of simple discriminations. It is suggested that the sense organs are probably comparatively unchanged from those of fossil nautiloids. Acknowledgements. This paper is dedicated to the late Dr. Yves Merlet who collected the nautiluses used in this study.We would like to thank Prof. J. Z. Young for all his support and encouragement. The Royal Society, The Percy Sladen Memorial Fund, and University College, London, provided the financial support that enabled one of us (V.C.B.) to collect nautiluses. The Science Research Council, U.K., provided the electron microscope used in the major part of the study and a grant to one of us (V.C.B.). We would also like to thank Prof. J. B. Gilpin-Brown who provided Fig. 1, Dr. R. Catala, for aquarium facilities, Mr. M. P. Legand and the Institut Français d'Oceanie, Noumea, New Caledonia, for laboratory facilities, Dr. J.-M. Bassot and Dr. Anna Bidder for advice on catching and preserving nautiluses, Mrs. Judy Parkes and Mr. M. Barker for photographic assistance, and Miss J. Date for secretarial assistance.     

From intensively agricultural practices to hay-making without fertilization

In the valley of the Dutch brook Drentsche A formerly fertilized lots came under hay-making without fertilization practices. The vegetation at the beginning of the experiments varied depending on the intensity of former agricultural practices.Clustering revealed unidirectional successional lines in all lots with relatively large changes in the first four years. Changes still occur after 30 years of unfertilized hay-making. Changes concerning vegetation types as well as increasing or appearing and decreasing or disappearing species suggest a diminishing availability of nutrients as the main environmental process. Therefore it is concluded that after a period of fertilizing some restoration of plant communities associated with former agricultural practices is possible.Variation already present within lots nearly always remained and in one lot a divarication of successional lines could be recorded, probably correlated with hydrological differences.The nomenclature of taxa is according to Heukels & van Ooststroom (1977), that of syntaxa according to Westhoff & den Held (1969), Ellenberg (1978) and Everts et al. (1980).The authors would like to thank Drs. N. Schotsman, Drs. A. Zeevalking-van Yperen, Drs. L. Rohof, Drs. P. Struyk, Drs. G. Boedeltje, Mrs. E. Hermans and Mr. W. van der Lans for recording the permanent plots, to Mr. E. Leeuwinga for drawing the figures and to Dr. S. Daan for correcting the English text.     

The effect of cultural conceptions on therapy: A comparative study of patients in Israeli psychiatric clinics'

This article explores the relationships between culture and therapy among patients from three contrasting Israeli groups: Persian, Ashkenazi and Moroccan Jews. The population studied is composed of persons who came to Jerusalem mental health clinics for consultation and treatment. Emphasis is placed upon the patients' conceptions and beliefs regarding health and illness as well as their actual behavior in this sphere. Systematic contrasts among the three groups are analyzed, and the ways these differences influence the treatment process are also discussed.The research was conducted by a multidisciplinary team including a psychiatrist (Krasilovsky) and three anthropologists (Minuchin-Itzigsohn, Ben-Shaoul, Weingrod). It was initiate and sponsored by Talbieh Hospital, Jerusalem, a psychiatric hospital belonging to the General Federation of Labor's Sick Fund. We are grateful to the Jerusalem Center for Anthropological Studies and its director, Dr. Edgar Siskin, for generous support. We should like to thank Dr. Eileen Basker and Prof. Virginia R. Dominguez for their extensive assistance in editing and translating. We also wish to thank Dr. Ram Aronson, director of the clinic at Talbieh Hospital, Dr. Jose Itzigsohn, director of the clinic at Ezrat Nashim Hospital, and Dr. Shlomo Litman, director of the clinic at Eitanim Hospital, and to express our appreciation to the staffs of all the clinics for their understanding of the significance of the research and for their help. We thank all of the patients who participated in this study. Finally, we wish to express our thanks to the editor of CMP and the anonymous readers for their many helpful suggestions.     

The effects of dissolved macro-nutrients on the herbaceous vegetation around dune pools

In Dutch coastal dunes the relation was studied between the composition of the vegetation on the banks of pools and the nutrients supplied by the groundwater. Areas infiltrated with eutrophic river water were compared with non-affected areas. The floristic composition was interpreted according to classification systems of ruderal, nitrophilous tall hemicryptophytes and the conservation parameters richness and rarity. Of the three main macro-nutrients (orthophosphate, nitrate and potassium), the orthophosphate load shows the highest correlation with the vegetation variables. It is suggested that a reduction of orthophosphate during pre-purification of the infiltration water would reduce the dominance of the ruderals to the extent that the original dune slack species could return locally.Nomenclature of species follows Arnolds & Van der Meijden (1975).We thank G. J. de Bruyn, W. H. van Dobben, W. T. de Groot, W. J. ter Keurs, F. van der Meulen, W. H. van der Molen, M. A. W. Noordervliet, and I. S. Zonneveld for their comments on the study; J. Braak, J. Brakkee and R. van Nood for their assistance with the chemical analyses; A. R. Kaal for the translation, and G. P. G. Hock for the drawing of the figures.     

Neuro-epithelial bodies in the respiratory mucosa of various mammals

Summary Lungs of fetal, neonatal and adult rabbits and of various other adult mammals were investigated. Several routine and silver staining methods, Falck's fluorescent amine technic and various electron microscopic techniques were performed.As in the human infant lung (Lauwerynset al., 1972) each of these techniques revealed the occurrence throughout the intrapulmonary airways of intramucosal corpuscles or so-called Neuroepithelial Bodies, composed of more or less parallely oriented, non-ciliated cylindrical cells which reach from the basement membrane to the airway lumen and display a prominent cytoplasmic argyrophilia, a less pronounced argentaffinity and an intense yellow fluorescence. Ultrastructurally, they are granulated, containing mainly two types of dense-cored vesicles of which the first type exhibits a positive reaction for serotonin (technic of Jaim-Etcheverryet al., 1968). They contain intracorpuscular nerve endings which form synaptic end formations upon the granulated cells.Though the functions of these serotonin producing Neuroepithelial Bodies remain furthermore unsettled, they seem to be related also to the recently reported AFG (Argyrophil, Fluorescent and Granulated) cells (Lauwerynset al., 1969, 1970a) and might be involved in various mucosal bronchial and bronchiolar neurosecretory processes; most probably they are chemo-, stretch- and/or tactile neuroreceptor organs modulated by the central nervous system.This study has been supported by a grant from The Council for Tobacco Research—U.S.A. and the Nationaal Fonds voor Wetenschappelijk Onderzoek—Belgium. We thank the Koninklijke Maatschappij voor Dierkunde of the Zoological Garden in Antwerp and Prof. Dr. J. Mortelmans for providing us with some rare animal species as well as Dr. J. Peuskens for interest in our studies. We thank B. Van Rijkel, J. Van Reempts, B. Emmanuel and R. Janssens for technical, G. Pison and St. Ons for photographic and N. Tyberghien for secretarial assistance.