bluuebunny/crossref_metadata_2025_split 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

AbstractWe 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.
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

AbstractUltraluminous 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

AbstractFrom 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

AbstractWe 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 hills and uplands of the UK
Authors: Cunningham J. M. M. , Groves C. R. 
Published: June 2019

AbstractThe 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

AbstractAn 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

AbstractThe 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.
Measuring preferences and the problems of identifying proximate needs
Authors: Lawrence A. B. , Illius A. W. 
Published: June 2019

AbstractCurrent 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

AbstractHuman-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

AbstractIrrespective 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 evolutionOn 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.
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

SynopsisRelationships 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

SynopisThe 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

SynopsisThe 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

SynopsisAcid 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

SynopsisExamination 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

SynopsisFindings 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.
The effect of ecological disturbance on competition between Crinipellis perniciosa and other tropical fungi
Authors: Bravo-Velasquez Elizabeth , Hedger John 
Published: June 2019

SynopsisIsolates 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.