bluuebunny/crossref_metadata_2025 huggingface dataset:
Long-Term High-Precision Monitoring from the Geneva Photometric Database
Authors: Burki G. , Kienzle F.
Published: June 2019

Very small amplitude variable stars are detected in the Geneva photometric database. Two examples of periodic variable stars with semi-amplitudes of 6.9 and 2.9 mmag are presented.
The Full-Sky Astrometric Mapping Explorer – Distances and Photometry of 40 Million Stars
Authors: Horner Scott D. , Germain Marvin E. , Greene Thomas P. , Harris Fred H. , Johnson Mark S. , Johnston Kenneth J. , Monet David G. , Murison Marc A. , Phillips James D. , Reasenberg Robert D. , Seidelmann P. Kenneth , Urban Sean E. , Vassar Richard H.
Published: June 2019

The Full-sky Astrometric Mapping Explorer (FAME) is designed to perform an all-sky, astrometric survey with unprecedented accuracy. It will create a rigid astrometric catalog of 4 × 107 stars with 5 < mV < 15. For bright stars, 5 < mV < 9, FAME will determine positions and parallaxes accurate to < 50 μas, with proper motion errors < 50 μas/yr. For fainter stars, 9 < mV < 15, FAME will determine positions and parallaxes accurate to < 500 μas, with proper motion errors < 500 μas/yr. It will also collect photometric data on these 4 × 107 stars in four Sloan Digital Sky Survey colors. NASA selected FAME to be one of five MIDEX missions funded for a concept study. In October 1999, NASA selected FAME for launch in 2004 as the MIDEX-4 mission in its Explorer program.
Semiregular Variables: The Character of Variability and Possible Subdivision of the SRc Class
Authors: Kudashkina L. S. , Andronov I. L.
Published: June 2019

It is proposed to split the SRc class into two subclasses with prototype stars PZ Cas and S Per.
Mira Variables: Statistical Parallaxes, Kinematics and Period–Luminosity Relation
Authors: Kilpio E. , Malkov O. , Kharchenko N. , Schilbach E.
Published: June 2019

Based on the statistical parallaxes, the mean absolute magnitudes and the spatial kinematical parameters were determined as functions of the periods for Mira variables given in the GCVS-4 and selected stars for which new kinematical data were obtained during the last decade. The BC were derived for the oxygen-rich Miras and the P–L relation was compared with predictions from pulsation theory. The following findings result from this analysis:

1) With respect to Miras, the GCVS-4 is complete down to V = 9m.

2) The kinematical and orbital parameters indicate a higher age for the oxygen-rich Miras pulsating with smaller periods.

3) The Mbol-period relation of the oxygen-rich Miras shows a low dispersion and does not depend on the pulsation mode. The resulting P–L relation is a superposition of P–L relations of different pulsation modes.

4) The fraction of the fundamental mode pulsators decreases with increasing pulsation period.
Variations of Light Curve Parameters in Miras with Progressive Period Changes
Authors: Marsakova Vladislava I.
Published: June 2019

Variations of light curve parameters in Mira variables with progressive period changes have been studied. They lead to a consistent sequence of the stars which is related to the helium flash model.
DIRECT Distances to Local Group Galaxies
Authors: Sasselov Dimitar D.
Published: June 2019

The two nearby galaxies, M31 and M33, are stepping stones for most of our current efforts to understand the evolving universe at large scales. We are undertaking a long term project, called DIRECT, to improve the direct distance estimate to M31 and M33. The massive photometry we have obtained as part of our project over the past 3 years provides us with very good light curves for known and new Cepheid variables, a large number of eclipsing binaries and other variable stars.
Phase Lag of Classical Cepheids and RR Lyrae Stars
Authors: Ogloza W. , Moskalik P. , Kanbur S.
Published: June 2019

It is a well-known property of Cepheids and RR Lyrae variables that their maximum brightness approximately coincides with the maximum expansion velocity. A more detailed investigation (Carson & Stothers 1984; Simon 1984) has shown that the velocity curve is in fact slightly retarded with the respect to the light variations. In this report we discuss the trends in the observed phase lag for an extensive sample of classical Cepheids and RRab variables.
New Results of Moscow Cepheid Radial Velocity Programme
Authors: Gorynya N. A. , Samus N. N. , Sachkov M. E. , Antipin S. V. , Rastorgouev A. S.
Published: June 2019

A sequence similar to Hertzsprung progression was revealed for Cepheid radial-velocity curves. We separated two pulsation modes for six double-mode Cepheids and determined radii for five of them. Several new spectroscopic-binary Cepheids were discovered; we present new preliminary orbital periods for V496 Aql, VY Cyg, and V1334 Cyg, in a combined table of our results on Cepheid binarity.
First Detection of a Frequency Multiplet in the Line Profile Variations of RR Lyrae: Towards an Understanding of the Blazhko Effect
Authors: Kolenberg K. , Aerts C. , Chadid M. , Gillet D.
Published: June 2019

We provide the first detection of a frequency multiplet in the line profile variations of RR Lyrae. Performing a period analysis on 669 high resolution line profiles obtained with the spectrograph ELODIE at OHP, we clearly detect a multiplet structure, with a separation equal to the Blazhko frequency, around the main frequency and its harmonics. The triplet components are very prominent; additional observations are needed to decide about the existence of a quintuplet. The complete understanding of the origin of the Blazhko effect still needs further theoretical modelling and better observations. Our detection of the frequency multiplet in the line profile variations is a first essential step towards a decisive confrontation between the theoretical models and the observations.
Nonradial Modes in RR Lyrae Stars
Authors: Dziembowski W. A. , Cassisi S.
Published: June 2019

We surveyed nonradial mode properties in evolutionary sequences of RR Lyrae star models, focusing attention on modes that may be driven by the opacity mechanism and on those that may be excited as a consequence of the 1:1 resonance with the radial pulsation. Our survey shows that all RR Lyrae star models share all qualitative properties of the nonradial modes. There is always a large number of unstable low degree modes with frequencies close to unstable radial modes. However, owing to higher mode inertia, for most of nonradial modes the driving rates are much lower than those for radial modes. The exceptions are the strongly trapped (STU) modes which begin with ℓ degrees 7 to 10 (depending on the model) at frequencies somewhat above the fundamental radial mode, and with ℓ = 5 or 6 at frequencies somewhat above the radial mode overtones. We argued that these modes are not likely candidates for identification of oscillations recently detected in some RR Lyrae stars. More likely candidates seem, in spite of their lower driving rates, the ℓ = 1 modes.

We found also that parameters which determine the chances of the excitation of nonradial modes through the 1:1 resonance do not vary much over the range of RR Lyrae star parameters. According to our estimate the excitation has a high probability. In fact, some nonradial modes should be excited in the majority of the RRab pulsators and in a significant fraction of (~ 30%) of RRc pulsators. The actual number is likely greater because we ignored the effect of rotation, which increases the probability of resonant excitation. The instability may lead to a periodic light curve modulation, that is to the Blazkho effect, if the nonlinear interaction results in a periodic energy exchange between the radial and the nonradial modes. A light curve modulation may also take place in the case of a constant amplitude limit cycle if the nonradial mode is of low degree and it is not symmetric about the rotation axis.

See Dziembowski & Cassisi (1999) for the full paper.
3-D Convection Models: Are They Compatible with 1-D Models?
Authors: Nordlund Å. , Stein R. F.
Published: June 2019

We review properties of stellar convection, as derived from detailed 3-D numerical modeling, and assess to what extent 1-D models are able to provide a fair representation of stellar structure in various regions of the HR diagram. We point out a number of problems and discrepancies that are inevitable when using conventional 1-D models. The problems originate mainly in the surface layers, where horizontal fluctuations become particularly large, and where convective energy transport gives way to radiation. We conclude that it is necessary (and possible) to use three-dimensional models of these layers, in order to avoid the uncertainties and inaccuracies associated with 1-D representations.
Physical Parameter Determination for the δ Scuti Star HD 200925
Authors: Peña J. H. , Paparó M. , Peniche R. , Rodríguez M. , Hobart M. A. , Cruz C. de la
Published: June 2019

HD 200925 is an unusual star: the period is stable on a time scale of many years, yet it shows variations which are either large and irregular, or small, suggesting a possible Blazhko effect (Poretti 1984; Joner & Johnson 1985); it has larger values of Teff and log g derived from uvbyβ than those of dwarf Cepheids of similar period; and it has a somewhat higher metal abundance, [Fe/H], than the Hyades. Furthermore, in conflict to what Joner and McNamara (1983) determined – that m1 index shows no variation with temperature – HD 200925 shows a definite variation, unlike that predicted in Crawford (1979). No explanation of this has yet been found. Johnson & Joner (1986) also derived an unusual and unexpected value of [Fe/H]. Finally, with respect to the pulsation periods of this star, Mantegazza & Poretti (1986) determined the existence of two periods: one definite, 0.26730 d and a possible second one of 0.2138 d which yield a ratio of P2/P1 = 0.800, the theoretical ratio expected between the first and the second overtones, found in other pulsating variables. All of these facts make HD 200925 an interesting star, motivating the present study.
Stellar Content of the Young Open Cluster NGC 6823
Authors: Pigulski A. , Kolaczkowski Z. , Kopacki G.
Published: June 2019

The preliminary results of the CCD search for variable stars in the very young open cluster NGC 6823 are presented. About ten new variable stars were discovered. The most interesting finding is that of the two pre-main sequence (PMS) δ Scuti-type variables. Because the evolutionary rate of period change is large at the PMS stage, these stars could be used in the future for testing it observationally.
Identification of Cool White Dwarfs in the Sloan Digital Sky Survey
Authors: Metcalfe T. S. , Mukadam A. , Winget D. E. , Fan X. , Strauss M. A. , Claver C.
Published: June 2019

We are searching for the coolest white dwarf stars in the galactic disk and halo. The Sloan survey, in due course, will identify an enormous number of new white dwarf stars which will better define the white dwarf luminosity function—an important tool for understanding the age and history of the stellar population of the galaxy. The broadband filter data obtained in the digital photometry phase of the survey will not permit identification of the most interesting of these, the coolest white dwarf stars. This is because the cool main sequence and subdwarf stars become indistinguishable from the white dwarfs in the various colorcolor diagrams. We have interference filters designed to separate out these classes of objects. We have obtained photometry of test fields to complement the Sloan data and identify the population of cool white dwarf stars. These data will ultimately resolve the controversies, based for the most part on small-number statistics, of the location of the turndown in the white dwarf luminosity function for the disk. If the halo is significantly older than the disk, we will find a second peak in the white dwarf luminosity function, at lower luminosities than the disk turndown. Our data will provide the first meaningful constraints on the location of the turndown in the halo white dwarf luminosity function.
Surveys and the Discovery of New Variable White Dwarfs
Authors: Vauclair G. , Dolez N. , Ning Fu Jian , Chevreton M. , Homeier D. , Koester D.
Published: June 2019

We report the discovery of a new variable DA white dwarf (ZZ Ceti): PG1541+650, identified as a potential ZZ Ceti candidate in the Hamburg Quasar Survey.
Big Game Hunting in the Andromeda Galaxy: Identifying and Weighing Black Holes in Low Mass X-Ray Binaries
Authors: Barnard R.
Published: June 2019

We have devised a new technique for identifying stellar mass black holes in low mass X-ray binaries, and have applied it to XMM-Newton observations of two X-ray sources in M31. In particular we search for low accretion rate power density spectra; these are very similar for all LMXB, whether the primary is a black hole or a neutron star. Galactic neutron star LMXB exhibit these distinctive PDS at very low luminosities (~ 1036 erg s–1) while black hole LMXB can exhibit them at luminosities > 1038 erg s–1! Following the work of van der Klis (1994), we assume a maximum accretion rate (as a fraction of the Eddington limit) for low accretion rate PDS that is constant for all LMXB, and obtain an empirical value of ~10% Eddington. We have so far discovered two candidate black hole binaries in M31, exhibiting low accretion rate PDS at up to 3 x 1038 and 5 x 1037 erg s–1. If we assume that they are at <10% Eddington, they have minimum masses of 20 and 4 M⊙ respectively. Furthermore, any LMXB exhibiting a low accretion rate power density spectrum at a luminosity > 5 x 1037 erg s–1 is likely to have a black hole primary.
6.13 Drinking Water as a Carrier of Trace Elements for Cattle
Authors: Humphries W. R. , MacPherson A. , Farmer Phyllis E.
Published: June 2019

The prevention or treatment of trace element deficiencies in grazing livestock can be both expensive and inconvenient. As an alternative to the customary parenteral administration of copper (Cu) or the use of cobalt (Co) bullets, we have investigated the feasibility of treating animals by supplementation of their drinking water with Cu or Co, using the Rowett Water Proportioning Device (Patent No. 16784/78).
Trade off between thermal comfort and pollutant (ammonia) exposure in pigs
Authors: Jones J. B. , Wathes C. M. , Webster A. J. F.
Published: June 2019

The thermal insulation of pigs (Sus scrofa) is considered poor (Mount and Ingram, 1965) as they do not have a thick coat and have a variable subcutaneous fat thickness. Ventilation rates in animal houses are often reduced in colder weather to maintain an optimal thermal environment. However this may fail to remove atmospheric pollutants (e.g. Menses, 1987).
Early feeding experience in chicks and piglets: effect of social factors
Authors: Meunier-Salaün M. C. , Turro-Vincent I. , Picard M.
Published: June 2019

Young animals learn feeding through trial and error processes and from social models, especially the parental one (i.e. Suboski and Bartshumas, 1984). Under practical conditions the mother-young bond has been reduced by early weaning in piglets or deleted in artificially hatched chicks. In both cases feeding experiences develop in groups of congeners of the same age. Negative reinforcements of feeding experiences have been demonstrated with diets containing concanavalin A from jackbean seeds (Canavalia ensiformis) (Leon et al., 1991). Preliminary trials suggested that piglets react similarly to jackbean containing diets. The aim of the present experiment was to investigate the capacity of piglets and chicks to influence the feeding behaviour of conspecifics according to their previous feeding experience (negative with concanavalin A, or neutral) and their social reactivity.
Epilithic diatoms of the Clyde Estuary
Authors: McLean R. O. , Gow T. A. K. , Webster J. , Arthur A. , Curtis D. J.
Published: June 2019

Synopsis

Epilithic diatom communities of the Clyde Estuary demonstrated no spring or autumn bloom. Species diversity and dominance were stable at the ends of the estuary and fluctuated through the year in midestuary. Species succession differed from regions where one species dominated throughout the year, e.g. Opephora martyi Heribaud at Bowling (high tide), to those where the dominant species was constantly changing e.g. Erskine (low tide). In all 307 species were recorded, twenty-nine very rare, 172 rare, nineteen were abundant, some e.g. Opephora martyi, Navicula mutica var. cohnii (Hilse) Grun. having wide niche breadth (B>60). others being restricted in their distribution e.g. Nitzschia paleacea Kütz. (B=10.4), Navicula pseudocomoides Hendey (B = 14–8). N. mutica var. cohnii and var. mutica Kütz. were difficult to distinguish in terms of valve morphology, as intermediate forms existed. In the estuary, smaller valves occurred towards the freshwater end. Two clones, originating from a 12/μm and a 26 nm valve (length) corresponding to descriptions of var. cohnii and var. mutica respectively, behaved similarly in culture throughout a range of salinity, in terms of size expression, suggesting no taxonomic difference. Diatom community photosynthesis was affected by salinity, reflecting the site of origin.
Seasonal studies on the phytoplankton and primary production in the inner Firth of Clyde
Authors: Boney A. D.
Published: June 2019

Synopsis

Analysis of the factors influencing the seasonal changes in biomass of the ‘net’ phytoplankton in 1972– 73 snowed that the dynamics of the spring waxing of the diatom populations were controlled by narrow ‘windows’ of climatic events, and that subsequent fluctuations in cell numbers were linked with the interplay between zooplankton grazing and wind induced dispersion. Data for 1976–77, set against a similar background of events with the ‘net’ plankton, showed that the nanophytoplankton constituted a less variable biomass through the seasons and, on an annual basis, contributed some 50% of the total carbon fixed.
The chemistry of the hydroxyl radical in the troposphere
Authors: Ehhalt D. H. , Dorn H.-P. , Poppe D.
Published: June 2019

Synopsis

Like oxidation in a flame, oxidation in the atmosphere is mediated by free radicals. By far the most important radical in the troposphere is the hydroxyl radical, OH. It is generated photochemically, and reacts with most atmospheric trace gases, in many instances as the first, and rate-determining, step in the reaction chains leading to their oxidation. Usually these chains regenerate OH thus maintaining OH at relatively large day-time concentrations of the order of 106 cm−3.

The most important reactions controlling local concentrations of OH form the framework of a photochemical reaction model, the results of which are compared to OH concentrations measured in the field at locations with different concentrations of pollutant attributable to the activities of man. The model-predicted OH concentrations are based on the simultaneously measured concentrations and photolysis rates of those trace gases that dominate OH chemistry at the local level.

Predicted and measured OH concentrations correlate reasonably well where concentrations of atmospheric pollutants are small but not where they are large. Explanations are being sought.
Air pollution and vegetation: hypothesis, field exposure, and experiment
Authors: Unsworth M. H.
Published: June 2019

Synopsis

Unravelling the subtle effects of air pollution on vegetation requires adherence to the experimental method for testing hypotheses. Three experimental approaches are described.Field releaseof pollutants causes minimal disturbance of other aspects of the environment but is difficult to control and to operate continuously.Closed chambers, such as glasshouses, are furthest removed from field conditions but many aspects of their environments can be controlled. There is scope for the more sophisticated use of computer controlled glasshouses to investigate responses of stands of crop plants and natural/semi natural communities.Open-top chambers(OTCs) are a popular research tool, but results from major studies such as the U.S. National Crop Loss Assessment Network are of uncertain general value. Incursion of air into the tops of OTCs creates vertical pollution gradients. Evaporation, and the stomatal control of transpiration in OTCs may be very different from that in the field. Uptake of pollutant gases in OTCs may also differ from that in the field, directly because of differences in air movement, and/or indirectly through differences in the distribution of temperatures and moisture.

The development and design of a U.K. research programme on red spruce is used to illustrate (i) the need to develop hypotheses from a wide range of observations, (ii) the advantages of using a range of experimental approaches and (iii) the requirement to synthesise results before reaching general conclusions.
Ecological consequences of arthropod grazing on VA mycorrhizal fungi
Authors: McGonigle T. P. , Fitter A. H.
Published: June 2019

Synopsis

Soil Collembola may be partially responsible for observed reductions in effectiveness of vesicular-arbuscular mycorrhizal (VAM) associations in the field, compared with sterile soil experiments. Feeding damage to hyphae in soil is envisaged as a mechanism by which translocation of phosphorous from beyond root depletion zones to the plants is reduced. Previous work has demonstrated such effects in pots and in a cultivated field plot, and direct observation of feeding has been made. This paper briefly reviews this evidence and presents an experiment in which insecticide reduced the density of Collembola in a seminatural grassland soil, and increased phosphorus inflow into roots ofHolcus lanatus. In addition, survey data are reported which show that hyphal grazing is ecologically feasible, as Collembola and infected roots are spatially associated with one another in the soil profile. It is suggested that hyphal grazing by these arthropods has important consequences for VAM function in natural vegetation systems.
The coprome: another model system – abstract
Authors: Cooke R. C. , Safar H. O. , Wood S. N.
Published: June 2019

The ability of Ascobolus crenulatus Karsten, Chaetomium bostrychodes Zopf and Sordaria macrospora Auersw. to produce biomass within, fruit upon, and degrade rabbit faeces was followed using semi-natural faecal resource units (copromes) (Wood & Cooke 1984, 1987). On these criteria the performance of the fungi was in the order C. bostrychodes > S. macrospora > A. crenulatus. Species mixtures produced only slightly higher degradation rates than those effected by single species. This implied competition for available nutrients which was also indicated by depressed fruiting of all species in species mixtures when compared with fruiting levels of each species grown individually. For single species the time of onset and subsequent fruiting level were determined by the time at which sufficient resources could be allocated to reproduction rather than simply to hyphal extension rates.
Effects of point source atmospheric pollution on fungal communities
Authors: Wainwright M.
Published: June 2019

Synopsis

While the effects of acid rain on soil biology and chemistry have been widely reported, relatively few studies have appeared on the effects of air pollutants on fungi. Air pollutants are, however, likely to cause both toxic (destructive) and enrichment disturbance effects on fungal populations. Such responses are best seen at sites located close to point source emissions, such as coking works and metal processing and sour gas plants, where pollutant concentrations will be locally high. Toxic disturbance by, for example, heavy metals will generally reduce fungal biomass and species composition leading to the impairment of important processes such as litter decomposition. Enrichment disturbance effects of air pollutants on fungal communities are less easily recognised, but occur when a pollutant, e.g. a phenol, acts as a nutrient, thereby leading to an increase in the total, or more unusually a specific part of, the fungal community. This paper reviews the literature on point source emission effects on fungi, with particular emphasis being given to the pitfalls encountered in such studies.
Introduction to the Porifera
Authors: Rigby J. Keith
Published: June 2019

Following rediscovery of the sclerosponges (Hartman 1969, 1979; Hartman and Goreau, 1970, 1975) and recognition of their similarities to the stromatoporoids (Hartman and Goreau, 1970, p. 221–228), classification and interpretation of fossil Porifera have undergone major revisions during the past ten years. Our interpretation of the “edges” of the phylum have been considerably expanded.
Fossil Demospongia
Authors: Rigby J. Keith
Published: June 2019

Demospongia have persisted as a major class of sponges since inception of the record of the phylum in the Cambrian. The class includes about 95% of all sponges in modern seas and all of the known freshwater forms, as well. These sponges occupy environments that range from warm, shallow subtidal, high energy to quiet, cold oceanic deeps. Demosponges range from exposed tide pool forms to cryptic dwellers and include the only boring sponges.
The practical exploitation of compensatory growth in pigs
Authors: Hillyer G.M. , Whittemore C.T. , Wilson D. , Taylor A.G. , Stamataris C.
Published: June 2019

The nature of compensatory growth in pigs remains unclear. But should pigs have undergone a period of growth retardation after weaning be capable of enhanced utilisation of food fed at the same level as their unretarded contemporaries, then exploiting the phenomenon would appear attractive to producers. Compensatory growth defined in this way is illustrated in Fig. 1.
Evaluation of Protein Feeds for Dairy Cows
Authors: Webster A.J.F. , Kitcherside M.A. , Keirby J.R. , Hall P.A.
Published: June 2019

A method is described for the description of feeds and feed mixtures in terms of their ability to provide truly digestible amino nitrogen (N) for cattle. Total basal endogenous N (TEN) loss is assumed to be 0.35g N/kg bodyweight0.75 (Report of A.R.C, Protein Working Group).

Feedstuffs are analysed for total N (TN), non-protein N and detergent-insoluble N (neutral detergent, NDIN and acid detergent, ADIN, van Soest, 1982). The disappearance of N is measured from samples incubated in nylon bags in the rumen of dairy cows for 0, 4, 8, 18, 24 and (for forages) 48 hr. Residual N in nylon bags after 18 hr incubation is subjected to 48 hr pepsin digestion to give pepsin-insoluble undegraded dietary N (PSUDN). Digestibility trials are run using three sheep for each test feed and faecal N analysed according to a modification of the method of Mason (1969) into detergent-insoluble faecal N, soluble faecal N and bacterial and endogenous debris N. Urinary N has also been measured since 1983.
Trends in Liquid Milk Consumption
Authors: Verner Wheelock J , Fallows Stephen J
Published: June 2019

Sales of semi-skimmed milk in the USA and in many European countries are increasing, while those of whole milk are decreasing. Although consumption of whole milk in the U.K. is much higher than in other EC countries, sales have been declining in recent years. The amount of semi-skimmed milk sold in the U.K. is very small and in many parts of the country can only be obtained with difficulty. The object of this paper Is to compare changes in demands for liquid milk in the U.K. with those of other countries in an attempt to understand the relationship between the market for semi-skimmed milk and for whole milk.
Urea supplementation of two forms of barley for intensively fed Friesian bulls
Authors: Edwards I.E. , Topps J.H. , Paterson G.F.M
Published: June 2019

Previous work has shown that treating moist grain with ‘Farmline’, a formalin acetic acid mixture, affords some protection of protein and perhaps starch from rumen degradation. A comparison with and without ‘Farmline’ treatment investigated the protection afforded to dried barley.
Effects of Feeding Level, Air Speed and Temperature on digestibility and Growth in the Calf
Authors: Cockram M. S. , Rowan T. G.
Published: June 2019

In the first 3 weeks of age the calf is most susceptible to diarrhoea. In a review of the literature, Williams (1977) concluded that the lower critical temperature of 3-day-old calves on restricted levels of feeding was between 9°and 13°C and by approximately one month of age was between 0° and 5°C. these temperatures can be increased by air movement (Blaxter and Wainmann, 1964). Grimble (1982) suggested that calves should not be exposed to air speeds greater than 0.25 m/s. Studies in older cattle and sheep, with a functional rumen, have shown that exposure to cold was associated with a lower apparent digestibility of feed, irrespective of changes in feed intake (Christopherson, 1976). Williams and Innes (1982) fed a milk substitute diet to calves from 24 to 38 days of age and compared housing the calves in air temperatures of 3° and 18°C. There were no significant differences between air temperatures in the apparent digestibilities of dry matter (DM), fat and nitrogen (N) (p>0.05) but there were significant increases in faecal water excretion and significant decreases in water intakes and urine volumes at 3° compared to 18°C (p<0.05). The present experiment was designed to determine the effects, at different feeding levels, of continuous exposure to cold (10°C) compared with warm (25°C) air and to low (<0.2 m/s) compared with high (>3.0 m/s) air speeds on (a) the apparent digestibility of a high fat milk substitute diet, (b) water intakes and faecal water excretions and (c) growth rates, in calves from 2 to 24 days of age.
Does straw reduce the hunger of pigs on restricted food allowances?
Authors: Lawrence A.B. , Appleby M.C. , Illius A.W. , MacLeod H.A.
Published: June 2019

There is increasing evidence that hunger and frustration of feeding motivation are potential sources of stress for pigs on restricted food levels such as tethered, pregnant sows. However, it is not clear what factor(s) of feeding regimes are critical in this respect. It has been suggested that the hunger of pigs on restricted food allowances may result in part from the use of concentrated foods lacking dietary bulk. This paper reports on 2 experiments conducted to examine the effect of straw as dietary bulk on hunger as measured by operant response rate.
Digestibilities of amino acids in soya-bean, sunflower, meat and rapeseed meals for pigs, and assessment of lysine digestibility as a measure of lysine availability for growth
Authors: Green S. , Kiener T.
Published: June 2019

Information on the digestibilities of amino acids in soya-bean, sunflower, meat and low-glucosinolate rapeseed. meals, and effects of manufacturing methods, should be useful when interchanging these foodstuffs in pig diets. Also of interest is the extent the determined digestibility values provide adequate measures of amino acid availability for growth.
Early-Weaning and Immunity in Piglets
Authors: Varley M.A.
Published: June 2019

Neonatal and post-weaning losses represent significant economic loss to the pig industry and in terms of animal welfare the loss of one in ten piglets within the first four weeks of life seems unacceptable. Many losses occur within hours of birth due to a variety of causes, such as overlying, chilling, starvation and disease. More losses occur in the first few days after weaning and the principal cause of these losses is disease. Enteric and systemic infections are therefore responsible for many of the deaths that occur in the early weeks of life. In addition to the pathogenic density in the environment the piglets immune responses determine susceptibility or resistance to disease challenge.

Passive and active immunity are related in a number of ways in their expression but both are profoundly affected by the various stressors that piglets are confronted with in the first few weeks of life. Stress stimulates increased concentrations of plasma Cortisol and this in turn depresses the various components of an immune response.

Amongst the stressors, weaning, mixing into new social groups and relocation may have the biggest effects. In modern systems of pig production piglets are weaned at 3-4 weeks of age and there is constant pressure on the use of expensive buildings, there is often a compaction of these stressors.
Sensory and Consumer Testing of Heat from Ram Lambs
Authors: Uransfield E. , Nute G.R. , Walters B.
Published: June 2019

Consumption of lamb in the UK has declined from 149g per person per week in 1970 to 93g in 1985 despite a reduction, in real terms, in its cost. Circumstantial evidence suggests that the decline is, in part, due to its excessive fatness. The use of entire male cattle and pigs increases the efficient production of lean meat and boars are now widely used. Although a similar potential has been recognised for lamb, British producers have maintained a policy of castration of lambs and butchers seem reluctant to sell meat from ram lambs because they suspect it may be inferior in eating quality. This work on sensory and consumer evaluation of meat from ram, castrate and ewe lambs was therefore conducted and forms part of an assessment of carcass and meat quality of entire Down cross lambs from crossbred ewes on improved hill grazing.

Forty-two lambs, comprising a balance of seven of each of entire male, castrate and ewe lambs from both Dorset Down and Suffolk sires, were reared at Redesdale EHF and slaughtered in August in a commercial abattoir. Hot carcasses ranged from 13 to 22 kg. To avoid the likelihood of induced toughness using conventional chilling conditions, all the carcasses were placed, at 2 hours after slaughter in a refrigerated vehicle operating at 10°C for transportation to Bristol.
Production of cattle embryos by in vitro and in vivo culture
Authors: K.H. Lu  , I. Gordon  , M. Gallagher  , H. McGovern
Published: June 2019

A previous report from this laboratory recorded a yield of 60 per cent of embryos recovered at the morulae/blastocyst stage of development after the in vitro maturation and fertilization of bovine follicular oocytes and their subsequent culture in vivo in the sheep oviduct (Lu et al., 1987). When these embryos were transferred by non-surgical procedures to recipient heifers, they established normal pregnancy rates (12/18, 67%) which resulted in the birth of seven sets of twins and five single calves. The objective of the present study was to examine the possibility of large-scale production of cattle embryos using the oocyte maturation and IVF procedures previously employed. A further objective was to determine the effect on embryo yield of transferring varying numbers of fertilized eggs (zygotes) to the sheep oviduct for in vivo culture.

Ovaries were collected fran beef heifers shortly after slaughter and brought to the laboratory within one hour, held at 30°C in phosphate buffered saline supplemented with 0.3 per cent bovine serun albumin and 0.05 mg kanemycin/ml. Non-atretic vesicular follicles (2 - 6 mm diameter) were dissected fran the ovaries and the oocytes liberated by follicule rupture, particular care being taken to preserve the integrity of the oocyte-cumulus-corplex.
Factors affect the performance and carcass characteristics of finishing grazed cattle within a 20 month beef system
Authors: Lowman B.G. , Hinks C.E. , Swift C. , Neilson D.R. , Hunter E.A.
Published: June 2019

The increasing sales of beef through retail supermarket outlets has been reflected in specification buying by wholesalers being more apparent. The objective of supermarket buyers is to obtain continuity of supplies throughout the year and this trend is likely to increase. Faced with these requirements producers of grass finished cattle (representing 40 per cent of beef supplies) have little objective information on which to plan their production systems. The limited scientific data available tends to be short-term with little, if any, information available on eventual carcass and eating quality.

A long-term project has therefore been initiated at Edinburgh to examine the effects of production variables on the performance and carcass characteristics of grass-finished cattle within a 20 month beef system. One aspect of this work has centred its attention on providing information on the rates of change (with time) of carcass characteristics, during the grazing season, in relation to breed, sex and variation in grass availability.
Effect of breed and sex on the deposition of branched-chain fatty acids in lamb fat
Authors: Enser M , Wood J D , Sinnett-Smith P , Woolliams J
Published: June 2019

The presence of high concentrations of branched-chain fatty acids in lamb fat results in soft discoloured tissue and objectionable flavours and odours. However, the factors regulating their synthesis and deposition are Incompletely understood. In some studies, but not others, excessive deposition is associated with high cereal diets. Their concentrations may be higher in rams than wethers and there is circumstantial evidence for differences between breeds. We have Investigated their concentration in ewe and ram lambs of three breeds: East Friesland, Oxford and Texel.

Ten lambs of each breed and sex, born in March, were fed to appetite twice daily a concentrate (barley 683 g/kg, crude protein 170 g/kg DM ME 12.1 MJ/kg D.M) with hay available ad libitum. Animals were slaughtered together, by conventional procedures, at 27 weeks of age (± 4 days) and the hind loin was removed and dissected. The subcutaneous fat was analysed for fatty acid composition by capillary gas-liquid chromatography on Chrompack CP Sil 88 and CP wax 57 CB.
The influence of dietary linoleic acid on backfat firmness in bacon weight pigs
Authors: Prescott N.J. , Wood J.D.
Published: June 2019

There is a growing concern in the UK meat industry over carcasses containing soft fat, which prove difficult to cut and process. This may be caused by the feeding of high levels of unsaturated fatty acids resulting in high levels in carcass fat, and hence soft fat. This trial examined the critical levels of linoleic acid affecting fat firmness.
Reproductive success of ewe lambs after a period of exposure to vasectomised rams
Authors: Al-Mauly N.Z. , Bryant M.J. , Cunningham F.J.
Published: June 2019

The fertility of ewe lambs is usually lower than that of mature ewes. Early embryo loss has been implicated as a cause of reduced fertility, especially when matings occur at the pubertal oestrus (Hare and Bryant, 1985). The Introduction of vasectomised rams to ewe lambs may hasten the occurrence of puberty and, if the introduction of fertile rams is not advanced, mating may occur later in the breeding season with possible advantages to fertility. This experiment investigated the effects of a period of association with vasectomised rams preceding the introduction of entire rams upon (1) the occurrence of puberty, and (2) the fertility of ewe lambs.
The effect of pre-treatment with progesterone upon the response of seasonally anovular ewes to the introduction of rams
Authors: Rekik M. , Bryant M.J. , Cunningham F.J.
Published: June 2019

The introduction of rams to seasonally anovular ewes, pre-conditioned by a period of isolation, may induce the episodic release of LH, follicular development and ovulation in the ewes. The CL formed after ovulation induced by the introduction of rams may not persist for a full luteal phase; some ewes may ovulate again, while others may lapse back into seasonal anoestrus. An injection of progesterone at the time of ram introduction has been shown to overcome the premature regression of CL (Martin et al., 1986). This experiment investigated the effects of giving progesterone at the time of ram introduction upon the response of two types of ewe treated during June and July.
Effect of barley, sugar beet pulp and protein level in the diet on growth, body composition and blood metabolites and insulin concentrations of entire male lambs
Authors: Galbraith H. , McCulloch T. , Scaife J.R. , Keeling B.J. , Atkinson T.
Published: June 2019

There is a continuing requirement to improve the lean content of meat, efficiently produced, as food for human consumers. Hormonal anabolic compounds which stimulate the deposition of lean tissue and reduce fat accretion in ruminant animals are not permitted in the UK. In the absence of the use of such exogenous compounds, alternative currently practical means of manipulating body composition include the use of genetic selection and alterations in nutrition. The objective of the present study was to investigate the effect of diets differing in the source of carbohydrate and in protein level. The diets chosen were based on barley (diet B) in which starch predominates and sugar beet pulp (diet P) which contains greater quantities of cellulose and hemi-cellulose.

Twenty-eight crossbred (Suffolk ♂ x mule ♀ )entire male lambs were used in the experiment. They were housed at approximately eight weeks of age in individual slatted-floor pens and gradually introduced to experimental diets over a period of three weeks prior to the commencement of the study. Four pelleted diets were offered.
Lactobacillus acidophilus fed as a probiotic in the rearing of purchased calves
Authors: Kay R.M. , Poole P.
Published: June 2019

For successful rearing of purchased calves, healthy animals with good utiization of feed are main objectives for profitability. Growth rate feed conversion efficiency (FCE) and health are adversely affected by pathogenic bacteria and antibiotics or chemotheraputic agents have been used as feed additives for several years. These may depress useful, non pathogenic bacteria and certain strains of pathogenic bacteria may become resistant to antibiotics. Probiotics are becoming increasingly advocated as being of benefit to calf rearers as a feed additive to improve the growth rates and health of rearing calves. An experiment at Drayton E.H.F. investigated the use of Lactobacillus acidophilus as a probiotic agent during the rearing period of purchased calves.
Carcass classification in the marketing of meat animals
Authors: Kempster A J
Published: June 2019

The principle of classification is that carcasses are described, using a common language which is understood by everyone trading in the market. The language relates to characteristics of commercial importance to traders but does not normally impute value, the essence being that the individual trader is able to identify the relative value of different classes for his particular business and specify price differentials (grade) accordingly. This encourages the production of carcasses more suited to market requirements.
Patterns of Winter Feeding For Spring Born Suckled Calves in Relation To Their Subsequent Performance At Grass
Authors: Chapple D. G.
Published: June 2019

The growth rates of weaned spring born suckler calves can be poor during their first winter because of low silage intakes. Feeding high levels of supplements is expensive and the increased growth rate is largely lost with a check at turnout. The objective of this trial was to improve the winter liveweight gains of suckled calves without affecting subsequent performance at grass.
The effect on the digestibility of selecting cows with high or low particle outflow rate
Authors: Ørskov E.R. , Ojwang I.A.
Published: June 2019

Differences in rumen volume can have considerable effects on the digestibility and voluntary intake of ruminants. For instance Mould et al. 1982 showed that cattle in Bangladesh had a much greater rumen volume relative to live weight than reported values of Friesian cattle. They also consume much more straw per unit of live weight than Friesian cattle.

Differences between cows in the ability to consume roughage have often been observed. It is however possible that this strategy could be adopted simply by increasing outflow rate and not necessarily by a high rumen volume. Depending on the strategy adopted this would give rise to differences in the digestibility of the roughage consumed.

In order to investigate these aspects in more detail, 22 lactating Friesian cows were given doses of Cr-mordanted straw having been ground through a hammer mill with a 2 mm screen. The cows were fed completely mixed diets consisting of 50% ammonia treated straw and 50% concentrate.
Factors influencing the gross energy content of grass silage
Authors: Givens D I , Brunnen Jeannie M
Published: June 2019

The gross energy (GE) of a feed represents its total energy content and is measured by burning the material in an atmosphere of oxygen in a bomb calorimeter. The GE of many feeds is often taken to be 18.4 MJ/kg dry matter (DM) (MAFF et al, 1984). This assumption is likely to be doubtful for feeds which are for example high in lipid or which contain products of fermentation. The gross energy content of grass silages in particular has recently been reviewed by Edwards (1986).

The GE content of grass silage can account for some 50% of the variability in metabolisable energy (ME). It is however ignored in present laboratory methods used for the prediction of ME which largely depend on using fibre fractions (Givens, 1986) which are more closely related to digestibility. This paper presents the results of GE determinations made on 109 grass silages made in clamps and since GE cannot be measured routinely, examines a number of factors which may be helpful in its prediction.
Arianism and the Byzantine Army in Africa 533-546
Authors: Kaegi Walter Emil
Published: June 2019

One of the principal motivations for the Emperor Justinian's reconquest of Africa from the Vandal king Gelimer (Gelimer reigned from 15 June 530 to 15 September 533), was religious: the desire to liberate the African Catholic majority of the population from their Arian Vandal persecutors. No critical study exists, however, which assesses the extent to which the Byzantine expeditionary force of 533 actually treated its invasion of Africa as a Catholic war against Arianism. Such a study would also provide some information on the obscure problem of the relative significance of Arianism in North Africa after the Byzantine reconquest. Clarification of this question has become desirable, for in a recent article C. J. Speel argued that the disappearance of Christianity in the wake of the Islamic conquest is explained by the affinity of Islam and Arianism, which he claims was the religion of the majority of North Africans after the Byzantine reconquest. His thesis deserves to be tested by the Byzantine sources: according to the sources, how successfully did Arianism in Africa survive the collapse of the Vandal authority which had established it?
‘An Invasion of Guest Worker Children’: Welfare Reform and the Stigmatisation of Family Migration in West Germany
Authors: Stokes Lauren
Published: June 2019

This article examines the effects of the 1974 child allowance reform on guest worker families in West Germany. As part of a wider reform, West Germany implemented a two-tiered system of child allowances whereby migrant parents received more money for children who lived in the European Economic Community (EEC) than for children who lived outside the EEC. Migrants protested the reform and with it the assumptions of the guest worker programme. However, these parents had to contend with a popular narrative whereby foreign parents who brought their children to West Germany after the reform were in fact irresponsible ‘welfare migrants’ who placed their desire for financial gain over their children's need for a stable environment. The idea that this specific welfare reform had been the trigger for large-scale family migration not only discouraged further investigation of the causes of family migration but was also used to support new restrictions on that migration.