bluuebunny/crossref_metadata_2025 huggingface dataset:
Digital Speckle Interferometry to Measure the Angular Diameters Of Faint Objects
Authors: Hubbard Gene , Reed Mike , Strittmatter Peter , Hege Keith , Worden Simon P.
Published: June 2019

We have developed a digital speckle camera for use on the University of Arizona 90-inch telescope. This camera uses a CID detector to provide photon locations in an image, or an analog image for brighter objects. We have used this system to observe Saturn's satellites Rhea and Iapetus. Using a correlation speckle technique, we have determined the angular diameter of these objects to be 1487 ± 40 km for Rhea, and 1200 ± 132 km for Iapetus.
Possible Si II Autoionization Lines in the Spectra of Ap Stars
Authors: Jamar C. , Praderie F.
Published: June 2019

An extensive study of ultraviolet spectra of Ap stars observed with the S2/68 TD-1 experiment has shown a large depression at 1400 Å in the spectra of Si and SrCrEu stars which is not present in the spectra of normal stars. This feature is attributed to Si II autoionization lines. More such lines seem to appear at longer wavelength in the UV and in the visible. We discuss the interest of an astro-physical plasma to detect and study autoionization lines in absorption.
Experimental Electron Excitation Rates for Ne VII
Authors: Lang J.
Published: June 2019

Excitation rates for Be-like Ne VII have been measured using a theta-pinch. The absolute intensity of the intercombination line allows the metastable level population density to be determined. The sum of the population densities of the ground and metastable levels is found by solving the time dependent ionisation-recombination rate equations knowing the temperature and density of the discharge as a function of time. The ratio of metastable level to ground level population densities thus obtained is compared to values obtained theoretically.

The experimental rates are compared to theory and the accuracy of using them for line ratios measurements of temperature and density are discussed.
Application of Monte Carlo Methods in Transfer Problems
Authors: Magnan C.
Published: June 2019

I have not prepared any formal communication. Nevertheless I would like to mention the types of calculation that are now in progress in Paris.

I am handling transfer problems in moving atmospheres by using Monte Carlo techniques. A twolevel atom and an isothermal atmosphere are always assumed. Two types“of geometry are considered: a spherical atmosphere with a constant velocity of expansion, or a flat disk with constant velocities of expansion and rotation. Non-coherent scattering (either entirely incoherent or partially coherent) is assumed with respect to the “local frequency“ (as seen by the absorbing atoms).

Concerning the “creation” of photons, two problems have been handled: the photons are created via absorption of a continuous spectrum produced by an underlying photosphere (the Schuster problem) or they are created within the envelope via electronic collision or recombination from ionized states.

The most typical results concern the Schuster problem.
Ultraluminous X-Ray Sources: an Observational Review
Authors: Fabbiano G.
Published: June 2019

Ultraluminous X-ray Sources (ULXs) are, as suggested by their name, extremely luminous and rare X-ray emitting objects found in galaxies. Because of their luminosity, it has been suggested that they may be powered by accretion onto a black hole (BH) of a few 100 M⊙, more massive than what one would expect to originate from normal stellar evolution. Alternative models include young supernova remnants (SNRs) beamed emission from normal BH X-ray binaries (XRB) with high accretion rates, and relativistically beamed XRB omission. The observational evidence on ULXs suggests that while most of them are likely to be compact accreting objects, there is no clear unique evidence pointing either to the beamed XRB model or to accretion onto a very massive BH. It is possible that what we call ULXs are a heterogeneous family of X-ray sources.
Chandra X-Ray Results on V426 Ophiuchi
Authors: Homer Lee , Szkody Paula , Raymond John C. , Fried Robert E. , Hoard D. W. , Hawley S. L. , Wolfe M. , Tramposch J. N. , Yirak K. Т.
Published: June 2019

From a 45ks Chandra observation of V42G Oph we have obtained high-resolution X-ray spectra at moderate signal-to-noise, and a, good quality, uninterrupted lightcurve. The spectra are reasonably fit with a cooling flow model, similar to EX Hya and U Gem. Our analysis of the Chandra and additional X-ray/optical lightcurves reveals a persistent modulation at 4.2 hr from 1988 to 2003, likely the white dwarf spin period indicating an intermediate polar nature for V426 Oph.
Fuse Studies of Dwarf Novae during Quiescence
Authors: Sion E. M. , Cheng F. H. , Godon P. , Szkody P.
Published: June 2019

We have obtained FUSE spectra of several dwarf novae which reveal the properties of their accreting white dwarfs, their rates of accretion during quiescence and the nature of their boundary layer/inner disk regions including accretion belts on the white dwarfs. Among the systems for which preliminary results will be presented are BV Cen, WW Ceti, EY Cyg, SS Aur and VW Hyi. The contribution of these FUSE studies to our understanding of disk accretion physics will be emphasized within the context of the white dwarf and boundary layer.
The New View on the Long-Therm Flickering in T CrB
Authors: Dobrotka A. , Hric L. , Petrík K.
Published: June 2019

The big scatter of data on the light curve of T CRB is identified with the flickering activity of the system. The data performed during April 1996 have a falling trend and they can be a part of a downward branch of a long-term and energetically powerful flare. Estimated energy 2 1035 J and the duration of this event were compared with the theoretical assumptions based on three typical physical scenarios, which can be the source of flickering. The dissipation of magnetic loops and the existence of the turbulent eddies are energetically deficient, but these scenarios are real in the case of less powerfull flares. The real explanation could be the instability of the secondary and variable mass transfer rate through the Lagrangian point, therefore through whole disc.
Multi-Wavelength Predictions of the DIM
Authors: Schreiber M. R. , Hameury J.-M. , Lasota J.-P.
Published: June 2019

Using the disc instability model (DIM) and a simple but reasonable model for the X-ray, extreme UV, UV and optical emission we investigate the multi-wavelength properties of dwarf novae. We discuss the predictions of the model in the context of the observationally best studied systems, i.e. SS Cyg and VW Hyi. We use the version of the DIM described in Buat-Ménard et al. (2001). The local spectrum of the emission from the disc is assumed to be given by Kurucz (1993,VizieR On-line Data Catalog). We also take into account emission from the (irradiated) secondary, the white dwarf, the hot spot, and the boundary layer.
The hills and uplands of the UK
Authors: Cunningham J. M. M. , Groves C. R.
Published: June 2019

The history of hill farming is traced from early times and the changes in practices described. The economic problems are analysed and the role of Government intervention has been outlined and assessed.

Research has created a basket of methods to exploit the potential of the ‘upland’ areas and these are discussed in relation to their up-take in practice and the role of the extension services in promotion.

The physical resources are briefly outlined and the contemporary economic development of the industry as influenced by the EEC and other agencies is discussed.

The impact of the demand for recreation, the need to conserve habitats and wildlife and the importance of rural amenity are examined in relation to upland agriculture and the several official organisations involved and proposals are offered. The conflicts in land use and the socio-economic problems of remote areas are discussed and appropriate policy initiatives are proposed.
Constraints in livestock research limiting animal production's contribution to socio-economic development
Authors: Dolberg F.
Published: June 2019

An important underlying concept of the paper is the observation by Dr R. Chambers that ‘poor people in developing countries hold the solution while unchanged behaviour of rich people, irrespective of place is very much part of the problem’. It is argued that it is equally important to know, and perhaps make changes, in the value systems, models of reality and cultures of those providing technical assistance (in this case the animal science community) as of those being assisted.

It is noted that so far the contribution of livestock research to increased animal production among rural smallholders has been meager. Some of the constraints in livestock research to socio-economic development are discussed under the following broad headings: some recent thoughts on science, scientists, and development, the contribution so far, context and priorities and communication.

It is concluded that the present first constraint in animal production research is relevant senior scientific leadership. It is also concluded that a positive strategy can be identified, which starts by placing more emphasis on exposing first-world scientists to the context of the third-world farmer as such an exposure is expected ultimately to lead to a change in research priorities.
Plant breeding technologies relevant to developing countries
Authors: Ceccarelli S.
Published: June 2019

The relevance of new and traditional plant breeding technologies is discussed with particular reference to the improvement of sustainable agricultural systems in difficult environments. The focus of the paper is on barley, a crop which is grown as animal food, mostly for small ruminants, on about 17 million ha in developing countries. Barley is also a typical low-input crop being grown largely in agriculturally marginal areas by risk-averse farmers. Differences in straw quality characteristics between varieties of some crops are discussed in relation to their utilization in breeding programmes using either conventional or new technologies. A greater interaction between animal scientists and plant breeders is needed to define appropriate techniques to screen for straw quality. This is considered to be essential to incorporate straw quality characteristics in breeding programmes.
The production of more fast–growing heavy pigs every year
Authors: Varley M.A.
Published: June 2019

The pursuit of enhanced prolificacy and fertility has been a major goal for the British pig industry for some years and throughout the 1960s to the 1990s advances were made that were generally due to better nutrition and management but genetics also played a significant role. Health status also influences reproduction and the production of faster growing pigs to slaughter. In recent years as farms have become larger and more intensive, our national health status may have been in decline to the detriment of female and male reproduction. Figures 13.1, 13.2 and 13.3 illustrate the changes we have seen in 3 important reproduction characteristics, using data from MLC yearbooks, 1970 to 2003. Farrowing index improved rapidly in the 1970s due, in part, to early weaning reducing the average farrowing interval, but also increased producer awareness of mating management and heat detection procedures helped to push this upwards.
Effect of Formi® within a Salmonella control programme for finisher pigs
Authors: Blanchard Paul , Kjeldsen Karsten , Dennis Ian , Ford Alan
Published: June 2019

The annual cost of Salmonella to the UK economy has been estimated at over £46 million and at €2.8 billion across the EU. The Food Standards Agency has made it clear that it wants to see a reduction in the proportion of pigs found to be carrying Salmonella when they arrive at the abattoir. The most recent results published to date (2000) show that 23% of UK pigs arriving at abattoirs carry Salmonella in their gut with 5% of pig carcases and 8% of pork sausages testing positive for Salmonella. While Salmonella cannot be eradicated on pig units, it can be controlled and minimised. With this in mind, the British Pig Executive (BPEX) have developed the “ZAP Salmonella Monitoring Programme” as a way of identifying farms with high levels of Salmonella and to act as the means of driving down overall levels (MLC, 2002).
Measuring preferences and the problems of identifying proximate needs
Authors: Lawrence A. B. , Illius A. W.
Published: June 2019

Current methodologies for measuring choices are the product of early psychological research into behavioural mechanisms, particidarly learning. In applied behaviour studies, much of the emphasis has been on the use of preference tests to assess animals’ motivation, and hence proximate need for, various forms of stimulation. Preference tests are based on a modular view of animal behaviour, where animals are presented with physical compartments each containing different resources such as food or social partners. An obvious limitation of the approach is that simple preference tests may do little justice to the complexity of animals’ behavioural organization and environmental preferences. Variability of choice behaviour also poses a considerable problem, as it may prevent us understanding and interpreting short-term choices and consequently describing the proximate needs of the animal. We also believe that the approach of applying consumer economics to quantify the value of resources to animals is increasingly moving preference testing away from measuring proximate to measuring ultimate need. This shift in emphasis does not appear to have been recognized. The risk is that the approach will only identify basic needs (e.g. related to growth and reproduction) but be insensitive to the proximate behavioural needs that it set out to quantify. In general, the focus of welfare-related preference testing should shift from the measurement and description of preferences to the more strategic task of understanding the rules governing short-term choices. We will be unable to measure proximate need unless we can develop a theoretical framework better able to interpret short-term behavioural choices.
Human-animal interactions in agriculture and their impact on animal welfare and performance
Authors: Hemsworth P. H.
Published: June 2019

Human-animal interactions are a common feature of modern intensive farming systems and these interactions may have marked consequences on animal productivity and welfare. Research in agriculture has shown interrelationships between the stockperson’s attitudes and behaviour and the behaviour, productivity and welfare of farm animals and the following model of human-animal interactions in agriculture has been proposed. Because a stockperson’s behaviour towards animals is largely under volitional control, this behaviour is strongly influenced by the attitudes that the stockperson holds about the animals. These attitudes and consequent behaviours predominantly affect the animal’s fear of humans which, in turn, affects the animal’s performance and welfare. The mechanism whereby fear affects performance and welfare appears to be through a chronic stress response. The risk to welfare also arises if the stockperson’s attitude and behaviour towards the animals are negative because the stockperson’s commitment to the surveillance of, and the attendance to, welfare issues is likely to be highly questionable.

Recent research in the pig industry has shown that a training programme targeting the key attitudes and behaviour of stockpersons produced improvements in stockperson attitudes and behaviour and animal behaviour and productivity. These results indicate the potential to improve animal productivity and welfare by targeting the stockperson’s attitudes and behaviour for improvement. Techniques which may be useful in this regard include staff selection and training procedures addressing these important human attributes.
The nutritional choices of farm animals: to eat or what to eat?
Authors: Kyriazakis I.
Published: June 2019

Irrespective of whether farm animals are given access to a single homogeneous food or to two or more heterogeneous foods as a choice, their feeding behaviour raises one of two questions (i) how much to eat, and (ii) what to eat? Despite frequent comment to the contrary, their feeding behaviour appears to be goal-orientated rather than random or purposeless. I therefore consider first the goals of farm animals in relation to their feeding behaviour. In general it is accepted that the overall biological framework in which all animals are trying to maximize fitness’ also applies to farm animals. However, some modification is called for in order to account for those situations in which intensive genetic selection has led to relatively ‘unfit’ reproducing animals and for those cases where animals are given access to foods which have not figured in their evolution

On the basis that feeding behaviour is goal orientated, I then consider whether farm animals achieve their goals by monitoring their behaviour in the short or longer term. The conclusion drawn is that while short-term feeding behaviour may be a device to exploit the feeding environment effectively, it is largely unrelated to short-term fluctuations in an animal’s internal state. By contrast, longer-term feeding behaviour is very closely related to longer-term change in internal state, implying the maintenance of close control over feeding behaviour in terms of food intake and diet selection. All animals, including farm animals, are considered to be creatures of habit which maintain habitual feeding behaviour until a change is provoked by a significant alteration in their internal state. Such an alteration requires to be of significantly large magnitude and to be unlike the usual short-term, systematic fluctuations which occur over a day in the profiles of metabolites or hormones. Based on this premise, I contend that the mechanisms by which these disturbances are perceived by the animal will be general rather than specific. The notion that animals can fully achieve their goals by monitoring their feeding behaviour is obviously applicable in situations where they are given appropriate nutritional choices. Where animals are given inadequate or inappropriate choices, as is predominantly the case with farm animals, their feeding behaviour is designed to bring them as close as possible to their goals. Finally I consider the relevance of nutritional choices to farm animals by addressing the possibility of exploiting the goal orientation of feeding behaviour. I conclude that greater recognition of the goal-orientated nature of farm animals’ feeding behaviour can bring benefits in three areas: (i) improved biological understanding of animals’ goals; (ii) improved animal welfare; and (iii) improved animal performance.
Limitations of palatability as a concept in food intake and diet selection studies
Authors: Rook A. J. , Penning P. D. , Rutter S. M.
Published: June 2019

The concept of palatability occurs frequently in studies of voluntary food intake and diet selection (see for example the numerous references in Forbes, 1986). The purpose of this paper is to suggest that the concept is of limited value. Four major areas are considered. The first is that of definition, as the term is often used in an ambiguous manner. Secondly, the use of palatability as a food descriptor is challenged since it is essentially an animal rather than a food characteristic. Thirdly, the usefulness of the concept is challenged in the context of its evolutionary and ecological significance. Finally, it is contended that the response of the animal is not necessarily a good measure either of the stimulus received or of the resulting internal state.
Social relationships between ewes of two breeds
Authors: Dwyer C. M. , Lawrence A. B.
Published: June 2019

Domestic sheep have a strong social tendency. However, the nature of social relationships varies with season, breed, and size of enclosure. Ewes occupy a smaller home-range, with larger subgroup sizes, in the winter compared with the summer months (Lawrence and Wood-Gush, 1988a). Domestication has apparently led to a reduction in nearest neighbour (NN) distances from feral (Soay) sheep, who do not have strong flocking behaviour, to Merinos with NN distances of less than 2 m (Arnold, 1985). The social choices made by ewes affect their foraging behaviour and may have significant effects on production (Lawrence and Wood-Gush, 1988b). The aim of this study was to examine the social choices of a hill and a lowland breed of ewe when grazing two different environments in spring and summer of 1995 and 1996. The influence of lamb genotype on the behaviour of the ewes was also investigated.
The responsiveness of suckling piglets to solid food presented in different forms
Authors: A’Ness P. J. , Horrell R. I. , Chen T. S.
Published: June 2019

The practice of early weaning of young piglets is associated with a sudden change in both their diet and their method of food acquisition. It can be argued that 4-week-old piglets are neither physiologically nor behaviourally prepared for these rapid changes and the provision of solid creep food is largely ineffective in facilitating adaption to weaning (Fraser et al., 1994). Previous studies which have attempted to promote solid food intake in pre-weaned piglets have tended to focus on dietary factors, such as palatability and digestibility (Bruneau and Chavez, 1995). However for ingestion to occur piglets must first perceive the food items and then establish an attraction to and acceptance of them.
The effect of cost of access on consumption of environmental resources in mink
Authors: Cooper J. J. , Mason G.
Published: June 2019

Captive animals may suffer if they cannot perform important behaviour and changes to their housing will be most effective at improving welfare if the modifications provide opportunities to perform those behaviours which are most important to the animal concerned (Dawkins, 1983). One means of identifying these behavioural priorities is to place a cost on their performance, as animals persist with the performance of the most important behaviours in the face of rising cost but cease to perform less important behaviours (Dawkins, 1983). There is, however, considerable debate over how best to measure persistence or elasticity of demand (Dawkins, 1990; Mason et al., 1997a) in terms of maximizing both their internal and external validity. To produce results with maximal internal validity it is important to follow the guidelines for using consumer demand theory presented by Mason et al., (1997b): that animals are tested in closed economies; that they are free to control their behavioural bout lengths; that resource use and cost must covary; and that the animals perceive the imposed cost to be equivalent for all resources.
Patterns of association between birds and invertebrates in the Clyde Estuary
Authors: Thompson D. B. A. , Curtis D. J. , Smyth J. C.
Published: June 2019

Synopsis

Relationships between feeding ecology, population dynamics and conservation of estuarine shorebirds are becoming better understood mainly as a result of detailed long-term studies of birds in the northwest European estuaries most vulnerable to industrial and agricultural developments. Until five years ago the tidal flats of the Clyde Estuary held internationally and nationally important populations of ducks (Anatinae) and waders (Charadrii). To understand the reasons for changes in bird distribution it is necessary to know more about the factors which determine distribution. In this paper we examine the pattern of association between the Clyde's birds and their prey by evaluating the extent to which the distribution of birds is related to that of benthic invertebrates, heterospecific birds, season and tidal state.

Stepwise multiple regression analysis indicated that heterospecifics had effects on bird distributions over-riding those of prey. In summer, the significant independent variables explained 41–61% variation in bird density (number km−2) and 33% variation in bird feeding hours (bird-hours km−2); in winter they explained 17–35% and 29–32% respectively. The amount of variation explained was greater during flow than ebb tides, and the number of species for which some of the variation was explained was greater in winter than in summer. Three associations, each consisting of two bird species, are suggested: redshank with lapwing, dunlin with mallard, and shelduck with gulls. We provide explanations for some of the mechanisms underlying the above patterns and indicate areas for more detailed observational and experimental work. The integrity of the avian component of the estuarine ecosystem appears to be dependent on associations and interactions between birds as well as between birds and their prey. The associations are labile, and in many species stem from the effect of tidal movement on prey availability.
The benthic fauna of sandy bays, with particular reference to Irvine Bay
Authors: Eleftheriou A. , Robertson M. R. , Murison D. J.
Published: June 2019

Synopis

The coastal areas in the Firth of Clyde, of which Irvine Bay is a representative example, receive important amounts of industrial and urban wastes which are a cause of economic and environmental concern.

Surveys of the benthos of Irvine Bay revealed a varied fauna dominated by large densities of opportunistic polychaetes such as Chaetozone and Spio and nematodes whose distribution correlated very strongly with the high organic carbon levels in the bay. The high densities and large biomass recorded in Irvine Bay were found to be 2–3 times higher than values from Loch Ewe, a clean area with normal carbon values.

All evidence from this survey points towards a situation in which the fauna is enhanced, yet does not suffer a species reduction.
The biology and management of herring and other pelagic fish stocks in the Firth of Clyde
Authors: Bailey R. S. , McKay D. W. , Morrison J. A. , Walsh M.
Published: June 2019

Synopsis

The herring population inhabiting the Firth of Clyde has supported an important fishery for hundreds of years. The basis for this fishery was until recently a stock of spring-spawning herring which spawn on Ballantrae Bank in the period February-April and which was investigated intensively by means of larval surveys from 1958 to 1979, when it had decreased to a very low level. In the late 1960s there was evidence of a change in the composition of the landings and during the 1970s and in the present decade the majority of fish caught have been of autumn-spawned origin. There is no evidence of significant autumn-spawning in the Firth of Clyde and autumn-spawning herring in advanced stages of maturation appear to leave the Clyde, returning by the time the fishery opens the following spring.

The spawning origin of autumn-spawned herring in the Clyde has been investigated by tagging experiments, and recaptures have been made in the Irish Sea, off the northwest Irish coast and further north along the west coast of Scotland. However the spawning area of the majority of the fish is unknown.

The herring fisheries in the Clyde, originally carried out by ring-net and anchored drift-net but now mainly by pair-trawl, have been managed by closed seasons and in the past few years by total allowable catch regulations under the control of the European Community.

There is also a population of sprats in the Firth of Clyde which supports a small fishery and spawning of this species takes place earlier in the Clyde than elsewhere around Scotland. Mackerel also make annual incursions into the Clyde and support a small summer fishery. Factors affecting the abundance of pelagic fish species in the Clyde are discussed.
Acid rain since 1985 – times are changing
Authors: Brydges T.G. , Wilson R.B.
Published: June 2019

Synopsis

Acid rain has been one of the first and longest running of the multi-national environmental issues. The phenomenon was described in the 1950s and 60s by noted scientists such as Dr Eville Gorham, Dr Svante Odén and Dr Harold Harvey. Scientific and public reaction to their work was generally negative.

Over the past two decades, the scientific understanding of the problem has dramatically improved. As this information became understood by the public, support for the control of atmospheric pollution increased to the point where virtually all industrialised countries are now implementing sulphur dioxide control programmes.

The industrial reaction to environmental control has become much more positive over the past few years with many industrial sectors now being equal partners in discussions of solutions to environmental problems. While pollution control programmes cost considerable amounts of money, it has been shown that these costs are manageable and that clean environments are conducive to economic development.

Opinion polls have shown that the public in Canada and the U.K., for example, places high priority on the need for environmental protection.

The positive industrial attitude, the increased public concern and the need to understand the science of complex environmental issues, in order to design the best possible control programme, together necessitate the involvement of environmental scientists in public debates if rational decisions are to be taken.
A view of disturbance and life strategies in fungi
Authors: Pugh G. J. F. , Boddy Lynne
Published: June 2019

Synopsis

Examination of fungal life strategies assists the understanding of the patterns of occurrence of an organism (or rather species) in nature. Fungi prevalent in disturbed situations tend to have many R-selected characteristics, although these are often combined with C-selected and S-selected characteristics depending upon the biotic and abiotic conditions to which their life strategies are best adapted. Many fungi probably exhibit different life strategies at different times during their life-cycle.
Early patterns of heterotroph activity in conifer logs
Authors: Carpenter Steven E. , Harmon Mark E. , Ingham Elaine R. , Kelsey Rick G. , Lattin John D. , Schowalter Timothy D.
Published: June 2019

Synopsis

Findings from the first two years of a long-term study of conifer log decomposition are presented. Log decomposition is regulated by the physical and chemical states, and development of decomposer foodwebs. The functional group with the greatest initial effect on the log is the channelisers, represented in our study by ambrosia and bark beetles. They not only create multitudes of channels into the logs but vector the initial decomposer community. Ambrosia beetles exclude certain elements of the decomposer community from channels until they vacate the log, at the end of their reproductive phase. The foodweb during the early stages of decomposition includes nitrogen-fixing and other bacteria, fungi, protozoa, nematodes, and arthropods. Seasonal fluctuations of temperature and moisture are hypothesised to work in tandem to modulate the activities of the decomposer community.
Microbial degradation of leaf litter in freshwater streams: effect of low pH – abstract
Authors: Chamier Anne-Carole
Published: June 2019

Many freshwater streams are predominantly heterotrophic, the energy source for all trophic levels of the biota being derived from allochthonous plant litter that is degraded by saprotrophic micro-organisms. Leaves falling into streams have most of their soluble constituents leached out within twenty-four hours of submersion. Few of the resident terrestrial saprotrophs survive in the aquatic environment and the leaves are rapidly colonised by freshwater fungi, particularly aquatic hyphomycetes (Chamier & Dixon 1982a; Chamier et al. 1984). These fungi produce all the enzymes required to degrade the structural polysaccharides of leaf cell walls and those of resident terrestrial fungi. Some species can degrade lignified tissue (Chamier & Dixon 1982b; Chamier 1985). Little is known of the enzymic capabilities of freshwater bacteria.
The effect of ecological disturbance on competition between Crinipellis perniciosa and other tropical fungi
Authors: Bravo-Velasquez Elizabeth , Hedger John
Published: June 2019

Synopsis

Isolates of the tropical fungus Crinipellis perniciosa obtained from cocoa and lianas in Ecuador were grown on media ranging from −0.45 MPa to −9.0 MPa water potential and their responses compared to those of other agarics and Xylaria species isolated from cocoa. Antagonism between mycelia of C. perniciosa and these isolates was also assessed over the same range of water potentials. It is hypothesised that C. perniciosa and other canopy inhabiting fungi of tropical forests are adapted to water stress, but are not competitive with fungi which colonise later, following litterfall, from lower litter and soil horizons, where water availability is higher. Xylaria spp. proved to be aggressive antagonists of C. perniciosa over a range of water potentials.
An Overview of the Fossil Record
Authors: Sprinkle James
Published: June 2019

Echinoderms are a moderately successful phylum today with five classes and about 6,000 living species. They are found in all marine environments from the intertidal zone down to the bottom of deep-sea trenches. Because most echinoderms have a stable calcite skeleton made up of many distinctively-shaped plates, spines, stem and arm segments, and other parts, echinoderms have the potential to produce a long and rich fossil record, and we find this to be true. Although our knowledge of this record is far from complete, some past echinoderm faunas may have approached present-day echinoderm communities in number of coexisting genera and species. Also, many classes of echinoderms are known only from the fossil record, and as many as 12–13 classes may have occurred together at some times in the past. Although they have a wide ecologic range today, most fossil echinoderms are found in rocks representing shallow-water, subtidal, marine environments, either past continental shelves or epicontinental seas.
Early Diversification
Authors: Sprinkle James
Published: June 2019

The initial explosive radiation of echinoderms in the Cambrian and Ordovician is very likely the single most spectacular evolutionary pattern shown by echinoderms during their long fossil record. This radiation involved 19–20 echinoderm classes and lasted from the Early Cambrian (perhaps latest Precambrian) to the end of the Middle Ordovician. It is important because in many ways this initial radiation determined the entire Paleozoic record for echinoderms. In addition, it is almost a textbook example of a major adaptive radiation (Raup and Stanley, 1978, p. 307, 357–360), and also fits nicely the two-stage metazoan diversification model for the Early Paleozoic outlined by Sepkoski (1979).
Homalozoa
Authors: Parsley Ronald L.
Published: June 2019

The Subphylum Homalozoa is divided into four classes, which while having similar morphological features, are at best distantly related. All classes exhibit flattened thecae, are bilateral to relatively asymmetrical and apparently were surface detritus feeders or low level suspension feeders. Many homalozoans display thick marginal plates with smaller central plates on dorsal and ventral surfaces, possibly to augment gut and/or cloacal pumping.
Paracrinoidea
Authors: Parsley Ronald L.
Published: June 2019

Paracrinoids were originally grouped together under the Orders Varicata (recumbent arms) and Brachiata (arms free standing) by Jaekel, 1900 and essentially the same groups were elevated to the Class Paracrinoidea by Regnell, 1945. Various authors have added genera to the class but the group was ill defined until Parsley and Mintz, 1975, re-defined it, establishing two orders based on the presence or absence of thecal pores rather than free standing or recumbent arms. The nature of the basals, peristomals, geometry and position of the gonopore and hydropore, thecal asymmetry makeup of the transverse uniserial pinnulated arms and the geometry and composition of the column are also important taxobases.
Paleozoic Asterozoa
Authors: Branstrator Jon W.
Published: June 2019

In accordance with the stated purpose of this short course to bring non-specialists up to date on advances in echinoderm paleontology, these notes build on what may be considered common knowledge of the Paleozoic Asterozoa. They are intended to be additions to information available in most paleontology textbooks and to update and comment on information presented in the Asterozoans section of the Treatise on Invertebrate Paleontology (hereafter referred to as the Treatise) written by Spencer and Wright (1966). Some reiteration herein of earlier works is necessary, however, to understand the current status of investigations on Paleozoic Asterozoa. Oral presentation during the short course will assume you are familiar with the material presented here.
Pharetronida: Inozoa and Sphinctozoa
Authors: Finks Robert M.
Published: June 2019

When sponges were well-behaved, a calcareous skeleton was sufficient for assignment to the Class Calcarea. Since the discovery that some sponges secrete both siliceous spicules and a massive calcareous skeleton (Class Sclerospongia Hartman and Goreau, 1970) and more recently, the discovery of an apparent living Sphinctozoan with an aspicular calcareous skeleton and soft parts like those of a demosponge (Vacelet, 1977b) the picture has become more clouded. The groups to be discussed here originally included all the known sponges with massive calcareous material in the skeleton. They were named Pharetrones by Zittel (1878) who emphasized the skeleton of anastomosing fibers, containing, so he thought, spicules packed side-by-side like arrows in a quiver (pharetra is Greek for “quiver”). Steinmann (1882) noted that in some of the genera included by Zittel as well as in new forms which he described, the skeleton was sheet-like and outlined a series of hollow chambers. Steinmann set apart the chambered types as a subgroup Sphinctozoa(=“constricted animals”) and the fibrous types as the subgroup Inozoa(=“fiber animals”). Steinmann also pointed out that the skeleton of the Sphinctozoa was aspicular and spherulitic. Zittel had illustrated the spherulites but considered them diagenetic. Steinmann, however, observed that the spherulites were bored by endolithic algae or fungi, and were therefore probably original. He also noted that the spicules in some Inozoa were sinuous and unlike typical sponge spicules, and indeed considered the pharetronids not to be sponges at all. Hinde (1884) and others soon demonstrated that the fibers of many pharetronids, as well as the external cortical layer (including that of the sphinctozoan Tremacystia) contained typical triradiates of the Class Calcarea. The discovery of the first living pharetronids (Doederlein, 1892, Kirkpatrick, 1900, 1908) with soft-parts and flesh-spicules typical of the Calcarea, seemed to settle the matter. Rauff (1913) introduced the useful term sclerosome for the non-spicular material of the skeleton, which might range from simple cement between spicules to the entire skeleton. It is this material that recent studies by Wendt (1979, 1980), Cuif and others (1979), and Jones (1979) have shown to be quite heterogeneous and variable. We will now look at the morphology and fossil history of the Inozoa and Sphinctozoa without any commitment as to the biological unity of each group.
Heteractinida
Authors: Rigby J. Keith
Published: June 2019

The Heteractinida are a relatively minor group of calcareous sponges, although Astraeospongium, one of the currently 14 known genera in the order, is one of the most commonly studied fossil sponges in the world. Principle record of the Heteractinida is from North America and Europe, although they have now been reported from Australia, Africa, Asia and South America. Occurrences in the latter areas generally are only isolated spicules or single specimens.
Chaetetids
Authors: West Ronald R. , Clark George R.
Published: June 2019

Chaetetids have recently emerged from relative obscurity on two fronts. On one, they have achieved a certain notoriety in their reclassification from tabulate corals to a recently erected class of sponges; on the other, they are becoming appreciated as locally significant faunal elements and bioherm framebuilders.
Stromatoporiods: Growth and Form
Authors: Stearn Colin W.
Published: June 2019

This summer in Washington one of the sessions of the Fossil Coral Symposium was devoted to the subject of stromatoporoids and their relatives; this fall a major part of this workshop on fossil sponges is being devoted to the same group. The closeness of these two meetings emphasizes the problematic nature of these fossils and focuses attention on a controversy over their affinity that is over 100 years old. Although these enigmatic fossils have many cnidarian features, I think you will agree that they are “in the right place” in this sponge workshop.
Stromatoporoids: Affinity with Modern Organisms
Authors: Stearn Colin W.
Published: June 2019

Controversy concerning the affinity of the stromatoporoids is not new; it began over 100 years ago with the first systematic studies of the group. Rosen's (1867) opinion was that these fossils were allied to the sponges. Nicholson and Murie (1878) agreed. Solomko (1885) introduced some of the arguments still used by the advocates of the poriferan affinity of the stromatoporoids such as the recognition of the astrorhizae as excurrent canal systems. H.A. Nicholson who had at first supported the hypothesis of sponge affinity became convinced that the closest living representatives were to be found in the hydrozoans. He compared the skeletons of the stromatoporoids like Actinostroma to the modern hydrozoan Hydractinia and the skeleton of amalgamate genera like Stromatopora to that of Millepora. Nicholson's monograph of British stromatoporoids (1886–92) and the papers he published in the Annals and Magazine of Natural History to accompany his revision of the group form the basis of all later work and hence his views on the affinity of stromatoporoids had immense influence.
Archaeocyathids: Morphology and Affinity
Authors: Debrenne Francoise
Published: June 2019

The Archaeocyatha were marine organisms developing mineral skeletons and using calcium carbonate for this purpose. Remains of their cups are found in carbonate shelfs and reef environments of the Early Cambrian seas. Few representatives of the family Archaeocyathidae are found through the Middle Cambrian to the Upper Cambrian (Debrenne, Rozanov and Webers, in press).
The Chinese Civil War and Implications for Borderland State Consolidation in Mainland South-East Asia
Authors: Han Enze
Published: June 2019

Few studies on the legacies of the Chinese Civil War have examined its effects on state consolidation in the borderland area between China and mainland South-East Asia. This paper empirically examines the impact of the intrusion of the defeated Kuomingtang (KMT) into the borderland area between China, Burma and Thailand. In the People's Republic of China (PRC), the presence of the US-supported KMT across its Yunnan border increased the new communist government's threat perceptions. In response, Beijing used a carrot-and-stick approach towards consolidating its control by co-opting local elites while ruthlessly eliminating any opposition deemed to be in collusion with the KMT. In the case of Burma, the KMT presence posed a significant challenge to Burmese national territorial integrity and effectively led to the fragmentation of the Burmese Shan State. Finally, in Thailand, Bangkok collaborated with the Americans in support of the KMT to solidify its alliance relations. Later, Thailand used the KMT as a buffer force for its own border defence purposes against a perceived communist infiltration from the north. This paper contextualizes the spill-over effects of the Chinese Civil War in terms of the literature on how external threats can potentially facilitate state consolidation.
The Strategic use of Nitrogen on Continuously Grazed Grass/Clover Swards
Authors: Purvis N. , Younger A.
Published: June 2019

The nitrogen fixing and nutritional benefits of including white clover in a pasture are well documented. However, where attempts have been made to increase herbage yield by the application of fertilizer nitrogen, only the grass component of the mixture is stimulated. The white clover is placed at a competitive disadvantage for other aspects of the environment, especially light, and is adversely affected.

In many practical grazing systems, where defoliation is continuous rather than intermittent, it might be possible to maintain the crop canopy at a level where shading is unimportant. Similarly, if modest amounts of fertilizer nitrogen are applied when clover is least likely to be affected, the adverse effects may be minimized. Thus, the objectives of this study are to examine the extent to which fertilizer nitrogen can be used to improve animal production from a grass/clover sward by increasing herbage production whilst maintaining an effective clover population.
Reproductive processes in sows having short lactations
Authors: Varley M. A.
Published: June 2019

In recent years there has been a general trend in the pig industry towards early weaning. A number of factors were responsible for this but perhaps the major reason was that of economic pressure dictating increasing sow productivity. Early weaning was putatively the means for the production of more piglets per sow per year. In Table 1 are presented data derived from the Meat and Livestock Commissions Pig Improvement Services over the years 1970-1983. This data illustrates the changing pattern of production. The indications are that this trend will continue.
Studies on the composition and physical form of the diet on gastric abnormalities and nutrient utilisation in the growing pig
Authors: Potkins Zoë V. , Lawrence T. L. J. , Thomlinson J. R.
Published: June 2019

The physical form of the diet has been shown to be a factor causing the development of oesophagogastric abnormalities and ulcers in the growing pig. A series of growth trials was made to investigate this. The particle size of the diet was varied by grinding through 4.68 mm and 1.56 mm screens and by pelleting. Fibre, in the form of bran or oatfeed, was added to the fine diet. The effect of bran and oatfeed on digestibility and rate of passage through the gut was studied in metabolism experiments.
Ethological factors influencing the occurence of oestrus in lactating sows
Authors: Stolba A. , Henderson R.
Published: June 2019

Observations in Edinburgh on Large White domestic pigs kept in groups outside or in family pens have indicated that sows regularly exhibit lactational oestrus in rich social and physical environments. In the pig park enclosure oestrus occured in 20 of 25 lactations and in all 21 lactations in the enriched family pen system. To further assess the stimulatory importance of selected factors of these environments, lactating sows were housed on three treatment levels differing in environmental complexity: i) conventional farrowing crates, ii) larger pens with optional outside yards, iii) enriched family pens. On each housing level additional treatment factors were applied: locomotory or manipulative possibilities, partial or full social contact with other sows and boars, restriction of suckling or piglet contact.
The energy value of body-weight change in adult cattle
Authors: Bruce J M
Published: June 2019

It is important to have a quantitative knowledge of the energy value of body-weight change (EV MJ/kg) when designing nutritional strategies for dairy and beef cows. Published values for EV vary widely. For example Chigaru and Topps (1981) give values for cows from 3.7 MJ/kg to 26.9 MJ/kg and Alderman, Broster, Strickland and Johnson (1982) give a mean value as high as 89.1 MJ/kg in mid-lactation. A wide range of values are also calculated for lactating ewes by Cowan, Robinson, Greenhaigh and McHattie (1979). The current ARC (1980) recommendation for cows is to use a constant value of 26.0 MJ/kg. Using mean values can be useful to make practical progress but we cannot avoid facing the fact that averaging, even on a selective basis, tends to obscure real and high variation in reported values. This paper will present a mathematical development which will define what is meant by the energy value of body-weight change and discuss some implications which follow. A final solution to the basic problem is not proposed.