bluuebunny/crossref_metadata_2025 huggingface dataset:
An Overview of the use of Mollusks in Biostratigraphy
Authors: Sohl Norman F.
Published: June 2019

One of the prime objectives of the earth scientist is the delineation of the sequential history of the physical and biological evolution of the planet. Biostratigraphy provides one framework of reference for ordering the sequence of events for a large portion of earth history. Representatives of the Phylum Mollusca have played a central role in the development of this frame of reference and indeed in the development of the discipline itself. Molluscs have had an important role since the earliest efforts to utilize fossils for purposes other than as objects of beauty, veneration or commerce. Indeed, William Smith's observations in the 1790's, that certain fossils were characteristically restricted to specific rock units in the vicinity of Bath, England, was primarily a delineation of molluscan species that to this day are recognized as distinctive of the Jurassic Bathonian Stage. Although the term biostratigraphy was not coined by Dollo until the early 1900's, the guiding principles and practices that evolved much earlier through the efforts of such pioneer biostratigraphers as d'Orbigny, Quenstedt, Oppel and Buckman were based primarily upon the study of the stratigraphic and spatial distribution of Jurassic molluscs. The part played by molluscs in these early studies is amply demonstrated by the fact that local Jurassic stages were named after fossil rather than place names by French and Swiss geologists - the Pterocerien and Strombien Stages for snails and the Astartien, Diceratien and Pholadomyen Stages for clams. Although subsequent work has seen the demise of such local nomenclature, these units remain recognizable as defined. In spite of later refinement, the principles and many of the zonations developed by these founders have stood the test of time for over a century and a half.
A comparison of twin and triplet lamb rearing
Authors: Gallo C. B. , Davies D. A. R.
Published: June 2019

In high prolificacy sheep production many ewes produce more than 2 lambs. The trial reported here was designed to look at triplet rearing as a system of dealing with the extra lamb. The effects of the method on both ewe and lamb performance were recorded.

The trial involved 32 Cambridge and Suffolk x Cambridge ewes, aged 3 to 5 years, and their progenies (32 twin and 48 triplet lambs). From 8 to 36 days post partum the effect of rearing type was investigated in combination with the feeding of the ewe with a complete diet containing either 25% or 40% coarsely milled hay (table 1).
The effect of pattern of feed distribution during late pregnancy and lactation on sow productivity
Authors: Harker A.J. , Cole D.J.A.
Published: June 2019

Catabolism of the sows’ maternal body tissues which commonly occurs during lactation starts not at parturition but during the latter part of the preceding pregnancy. An experiment was conducted to study the response of sows to the same amount of feed distributed differently between pregnancy and lactation.

Two patterns of feed distribution taking account of the anabolic/catabolic change in late pregnancy were compared with a conventional system which makes the major change in feed level at parturition.
The way Ahead in Milk Marketing
Authors: Groves C R
Published: June 2019

The paper sets out to stress that although marketing is often put forward as one of agriculture's weaknesses (or even failures) it is wrong to assume that good marketing is a panacea. It can in fact be argued that the emphasis on the importance and relevance of marketing in agriculture today is in the circumstances merely a natural development. The way ahead in milk marketing as much as agricultural marketing is for this development to continue gradually. Dramatic results should not be expected in the short terra but in time may be expected to contribute significantly to the survival of the dairy and agricultural industry in the UK.
Selection for prolificacy in pigs
Authors: Avalos E. , Smith C. , Bichard M.
Published: June 2019

Pigs can be bred at 6 months of age. By this time it is possible for their dams to have two litter records (at 12 months and 18 months of age) on which selection for litter size can be based. Hence, a generation interval of one year for both males and females can be achieved. Ollivier (1974), has shown that this system maximizes the rates of response. The accuracy with which replacements are chosen can be increased further by including information from other relatives (dam and sire family) in a selection index.
Responses by beef cattle to increases in either silage digestibility or proportion of rolled barley - comparative slaughter study
Authors: Thomas C. , Gibbs B.G. , Thurnham B. , Beever D.E.
Published: June 2019

The objective of the trial was to examine the effect on live-weight (LW) gain and its components of increasing the supply of nutrients either through an increase in the digestibility of silage or by increasing the proportion of rolled barley given with a low-digestibility silage made from late-cut herbage.
Effects of level of maize gluten feed in the diet on pig performance and carcass quality
Authors: Edwards S.A. , Prescott N.J. , MacDougall D.B.
Published: June 2019

Maize gluten feed is a by-product available as an alternative ingredient in pig rations. This trial examined the effects of different inclusion levels of the product to determine the quantity which could be fed without detrimental effects.

Diets containing 0, 10, 20 or 30% of maize gluten feed were formulated to have similar levels of digestible energy (12.9 MJ/kg) and lysine (0.9%).
A comparison of sequential implantation with Zeranol or a single implant with Oestradiol 17β
Authors: Kay M. , Reith T. L. , Hunter E. A.
Published: June 2019

Implants are widely used with both steers and heifers over the 100 days before slaughter. They are known to increase the growth rate and improve the carcasses of the cattle. Results were presented to this Society last year (Proceeding Winter Meeting 1983 paper 102) which showed that repeat implantation with Zeranol in steers weighing initially 55 or 175 kg produced worthwhile improvements in daily gain. The object of this work was to obtain information on the effect of a single implant of oestradiol 17 β with repeat implantation using Zeranol at 90 day intervals.
Growth rates and daily feed intakes of early weaned piglets fed either an ad libitum or restricted feeding regime on a commercial unit
Authors: Shepherd C M
Published: June 2019

An investigation was carried out to study feed intakes between 3 and 7 weeks of age for 3 week weaned piglets weaned into flat deck accommodation. Research has concentrated on the dietary requirements of early weaned piglets. Little information is available on the daily feed intake and liveweight gain of young piglets, on commercial units, over the initial post-weaning period.
D.I.Y. Cattle Pregnancy Detection using Doppler Ultrasound
Authors: Hooper P.N. , Jeenes P. R.
Published: June 2019

The isolation of non pregnant cows in a commercial dairy herd represents a substantial cost to the farmer. The majority of cattle pregnancy diagnoses (PD)'s in the U.K. are made from rectal palpation or by the use of (a) milk progesterone (b) milk oestrone sulphate or ( c) blood progesterone tests. A D.I.Y. pregnancy test has obvious advantages, namely:-

1.

Tests can be performed by farm stockmen at their own convenience.

2.

Diagnosis is made immediately.

3.

Tests can be made through complete pregnancy term.

4.

After initial capital outlay for equipment, the cost of tests is negligible.

Such an alternative is the doppler ultrasound (DOP) system (per rectum) which utilises audible changes in frequency of ultrasound between the transmitted signals and their echoes when moving surfaces are contacted.
The use of an ultrasound pregnancy detector for dairy cows
Authors: Rowlinson P.
Published: June 2019

Reduced performance may result from the failure to confirm pregnancy in dairy cows. The earlier after service that pregnancy can be reliably detected the more useful the method of detection is. Both milk progesterone and veterinary rectal palpation are useful for very early and mid pregnancy confirmation respectively but both have limitations. The BOVEQ (FarmKey Ltd.) detects pregnancy using ultrasonics. Ultrasound waves have the property of travelling through liquids and solids but not air (or any other gas). When they meet an interface between different materials (e.g. fat/muscle, muscle/bone or a pregnant uterus and its contents) thry produce an echo, the strength of which is dependant on how much difference there is at the interface. The uterus of a pregnant animal changes in “tone” and fluid content shortly after breeding and this change is characterised by a specific pattern of ultrasound echoes.
A model of pasture utilisation and ewe performance at mating in an upland flock
Authors: Sibbald A.R. , Gunn R.G. , Maxwell T.J. , Agnew R.D.M. , McFarlane D.N.
Published: June 2019

The amount of grass 8 weeks prior to mating, the condition of the ewe at that time, the stocking rate and the rate of herbage growth in the late summer and autumn will determine the condition score and ewe liveweight achieved at mating and during the post-mating period. Evidence suggests that for Greyface ewes, lambing rate increases with an increase in condition score at mating up to 3 provided that the achieved condition score can be held for 4-6 weeks post-mating.
The effect of recombinant bovine somatotrophin on milk production, reproduction and health of dairy cows
Authors: Thomas C. , Johnsson I.D. , Fisher W.J. , Bloomfield G.A. , Morant S.V.
Published: June 2019

The objective of the trial was to examine the effect of recombitant bovine somatotrophin (bSTH) on voluntary intake, milk solids output, body weight change, health and reproduction in lactating dairy cows given either a complete mixed diet or fed concentrate at a flat rate and forage ad libitum.
The application of new techniques for the control of growth in farm livestock
Authors: Lamming G.E.
Published: June 2019

The recent EEC Directive banning the use of anabolic agents as growth promoters in animal production in countries of the EEC and, by implication, prohibiting imports of fresh and processed meats from countries not applying a similar ban, has raised undue concern by research scientists involved in studies of the biochemistry and physiology of growth promoters. In addition to the well established growth response and improved carcass composition obtained from using anabolic agents (both naturally occurring hormones and zenobiotic compounds), there are exciting developments involving new pharmacological agents, new immunological techniques and the possibility of direct manipulation of the genome.
Fat growth and its partition between depots in crossbred steers by different sire breeds
Authors: Solly K J , Kempster A J , Southgate J R
Published: June 2019

Consumer resistance to overfat meat is growing because of its wastefulness and increasing concern about the probable link between fat consumption and health. Despite this, there is little evidence to indicate any material change in the fatness of British beef carcasses over the past 10 years. The average separable fat content of beef carcasses in both 1974/76 and 1984 is estimated to be 220g/kg (Kempster, Cook and Grantley-Smith, 1986).
Use of allantoin excretion to assess the energetic efficiency of rumen microbial protein yield in sheep
Authors: Dewhurst R.J. , Waters C.J. , Webster A.J.F.
Published: June 2019

The energetic efficiency of microbial protein yield from the rumen (E) is a major element of uncertainty in systems describing the supply and utilisation of dietary protein in ruminants. The relationship between microbial growth rate and E can be described with some precision in vitro but the situation is complicated in vivo by the necessity to determine microbial outflow rate from the rumen. The Agricultural Research Council (ARC 1984) assumed a fixed value of 32g microbial N/kg DOMR (organic matter apparently digested in the rumen) or 1.34g microbial N/MJ Metabolizable Energy (1.34g MN/MJME) while recognising that there are sound theoretical reasons why the relationship might better be described by a variable function.
The Effect of Sward Surface Height on Ewe and Lamb Performance
Authors: Keeling B J , Mackie C K , King M E , Watt C W
Published: June 2019

Sward Surface Height (SSH) can be used as a guide for grazing control and recommendations are available for target SSH at various times of the year and at different levels of performance (Hodgson et al 1986).

188 mule ewes with Suffolk cross lambs were allocated to 2 target SSH, 1-6 cm and 6-8 cm. Each treatment was replicated twice and balanced for ewe age, liveweight and condition score and the age, sex and rearing status of the lambs. The areas grazed were under permanent grass (mainly perennial ryegrass) and received 255 kg N/ha applied in 4 dressings with balancing P. and K. The initial stocking rate was 14.7 ewes/ha with 23.2 lambs/ha. SSH was measured weekly using an HFRO swardstlck with 40 readings taken per area. SSH was maintained using a temporary electric fence to adjust the size of the grazing area. Adjustments were made on a pre-set pattern which took into account any difference between current and target SSH and any change in SSH over the previous week. The area adjustments are shown in Table 1.

Lambs were weighed at fortnightly intervals initially and at weekly intervals from the beginning of July. Lambs were drawn for slaughter at constant condition (3L). Ewes were condition scored and weighed at turnout (12th May), 6 weeks after turnout and at weaning (11th August).
Evaluation of hunger In pigs using operant conditioning
Authors: Lawrence A B , Appleby M C , Macleod H C
Published: June 2019

Rules for feeding pigs have been derived from nutritional and economic considerations with little if any awareness of their behavioural consequences. Pregnant sows generally receive sufficient of a standard sow diet to allow medium growth during pregnancy. This quantity of food is, however, in the order of 0.5 of their (preferred) ad libitum intake (Whittemore et al., 1977). Recent results at Edinburgh have suggested a strong relationship between the food level and the development of stress-related activities, such as repetitive chain chewing, in tethered pregnant gilts (Appleby and Lawrence, 1987). Gilts on low feed levels performed significantly more repetitive behaviour than those on higher levels. These results suggest a link between the motivation to feed (hunger) and stress. There is, however, no information available regarding the hunger of pigs maintained on restricted food levels.
The effect of pre-weaning diet on post-weaning health and performance of 3 week weaned pigs
Authors: Lightfoot A.L. , Miller B.G. , Spechter H.H.
Published: June 2019

An experiment was carried out at Terrington to investigate the effect of pre-weaning solid feed or no pre-weaning feed for suckling piglets using diets of either high or low protein levels. Previous work at Terrington with 3 week weaned pigs showed that post-weaning performance had a big effect on subsequent performance so the trial pigs were monitored through to slaughter. Research at Bristol University showed that “abrupt weaning”, i.e. no pre-weaning feed can reduce post-weaning diarrhoea.
The ‘Cervuli’ and ‘Anniculae’ in Caesarius of Arles
Authors: Arbesmann Rudolph
Published: June 2019

Two passages in the sermons of Bishop Caesarius of Arles († 542) have aroused the special interest of philologists and students of the history of religion alike. The first passage is found in the concluding section of a sermon in which the bishop scathingly criticizes some superstitions and heathen customs which, to all appearances, were still rife among the common people of his day.
Air Transport in New Zealand and the South Pacific
Authors: Isitt Leonard
Published: June 2019

The Seventh British Commonwealth and Empire Lecture, “Air Transport in New Zealand and the South Pacific,” by Air Vice-Marshal Sir Leonard Isitt, K.B.E., R.N.Z.A.F. (Ret'd.), was read before the Royal Aeronautical Society by Mr. T. A. Barrow, J.P., on 4th October 1951 at the Institution of Civil Engineers, Great George Street, London, S.W.I. Major G. P. Bulman, C.B.E., F.R.Ae.S., Past-President, presided.

Major Bulman: He was sure that they would all regret that Major Halford was unable to be present; immediately after the reception following the Wilbur Wright Lecture, he had had an operation, and although it was successful he had to undergo a course of treatment which would keep him out of circulation for another five or six weeks. They hoped that at the end of that time they would enjoy his presence and leadership for the rest of his year of office.

It was for him a very real pleasure, despite the sad reason, to take the chair for the second time at a British Commonwealth and Empire Lecture. These lectures—instituted originally by Mr. G. H. Dowty—were given alternately by a distinguished representative from the Mother Country and from the Dominions and Empire. They had had one from Australia, two from Canada and now New Zealand.

Air Vice Marshal Sir Leonard Isitt had had a distinguished career in the Air Force, first with the R.F.C. and Royal Air Force and then with the Royal New Zealand Air Force, and had now turned his attention to civil aviation. He was Chairman of New Zealand National Airways Corporation and of Tasman Empire Airways and a Director of British Commonwealth Pacific Airlines. Unfortunately, because of the recent election in New Zealand he had found it impossible at the last minute to be with them. They had just received a cable from him: “Regret inability to be with you in England today. Please accept apology and best wishes.”

In place of Sir Leonard Isitt they had the pleasure and privilege of welcoming Mr. T. A. Barrow, J.P., who would read Sir Leonard's paper. Mr. Barrow had been Secretary of the New Zealand Air Board since 1937. He was also Vice-Chairman of Tasman Empire Airways.
Experience in establishing a herd book for the local Nguni breed in South Africa
Authors: Scholtz M.M. , Ramsay K.A.
Published: June 2019

For many years the performance of the indigenous livestock of Africa was regarded as inferior. It was only when the results of research and performance recording were published that the value of a breed such as the Nguni was acknowledged. This resulted in an interest in the breed from commercial farmers, which lead to the establishment of a breeder's society in 1986, but with no official pedigrees it was a challenge to establish a herd book.

This article describes how the principles of upgrading were initially used to develop a herd book until the Nguni was recognized as an established breed in 1996. Subsequently a system of first registration was implemented. This system caters for emerging black farmers in South Africa who want to become seed stock breeders and allows for the good quality Nguni genetic material available to the communal black farmers to enter the seed stock industry.
Integrating policies for the management of animal genetic resources with demand for livestock products and environmental sustainability
Authors: Blackburn H.D.
Published: June 2019

Global recognition of the need to conserve animal genetic resources comes at a time when the livestock sector faces significant challenges in meeting the growing demand for livestock products and the mitigation of negative environmental impacts caused by livestock. In developing regions it would seem that portions of the growing demand for livestock products are being met by increasing animal numbers instead of achieving increases in production efficiency. Concurrently, extensive grazing and mixed crop-livestock production systems are largely responsible for significant greenhouse gas emissions and other forms of environmental degradation. Under the growing demand and environmental sustainability rubric there exists a need to garner maximum benefit from diverse animal genetic resources. These three areas; growing demand on animal products, environmental issues, and conservation of AnGR form a nexus that national policies must simultaneously consider. To advance this integration, a policy framework is proposed that consists of incentives to produce, a secure resource base (e.g., genetic resources, land tenure) and access to markets for outputs and inputs including technology. Within this framework a set of potential policies are suggested that promote conservation, livestock sector growth and environmental sustainability.
Regulatory options for exchange, use and conservation of animal genetic resources: a closer look at property right issues
Authors: Tvedt M.W. , Hiemstra S.J. , Drucker A.G. , Louwaars N. , Oldenbroek J.K.
Published: June 2019

Three main areas for further development of policies or regulatory options for animal genetic resources (AnGR) were identified in a study on the exchange, use and conservation of AnGR (Hiemstra et al., 2006):

1. how to halt the further erosion of genetic diversity and promote sustainable breeding and use,

2. whether there is a need to further regulate the exchange of genetic material and

3 how to balance different systems of property and use rights.

This paper provides an in-depth analysis regarding the third challenge, that of addressing the problems and options available for balancing the different property right systems for AnGR.
Teaching Evolution within an Advanced-Undergraduate Paleontology Course
Authors: Cuffey Roger J.
Published: June 2019

Evolution seems most convincingly presented as a final unit in a comprehensive paleontology course, because the students by then will have learned about the procedures and data necessary to understand the relevant evidence. Transitional fossils, their logical implications, and the mechanisms of evolution should be particularly emphasized. Questions may still remain in some students' minds after presentation of the evidence, and devoting a full day to student questions helps them resolve many issues.
Examining the Creation-Evolution Issue as a Humanities Course
Authors: Manger Walter L.
Published: June 2019

In early 1981, the 73rd General Assembly of the State of Arkansas in regular session passed Senate Bill 482 without debate. Governor Frank White, immediately signed the bill, admitting that he hadn't read it, and it became state law as Act 590, the “Balanced Treatment for Creation-Science and Evolution-Science Act.” A suit on behalf of 23 plaintiffs was filed by the American Civil Liberties Union (ACLU) on May 27, 1981, and a trial before Federal Judge William Overton was scheduled for October and then postponed until December, 1981. The trial began on December 7, 1981, and it received national attention. The ACLU called well-known expert witnesses in both religion (Bruce Vawter, George Marsden, and Langdon Gilkey) and science (Francisco Ayala, G. Brent Dalrymple, Stephen Jay Gould, and Carl Sagan). The state's witnesses were creationists associated with the Geoscience Research Institute, Loma Linda University, California (Harold Coffin, Ariel Roth), and the Creation Research Society, Ann Arbor, Michigan (Wayne Friar, Margaret Helder, Donald Chittick, Robert Gentry). Its “star” witness, at least in the eyes of the press, was Chandra Wickramasinghe, University College of Wales. The trial did not involve any of the high profile creationists, such as Henry Morris or Duane Gish, from the Institute for Creation Research (ICR) in San Diego, even though it was disclosed that Wendall R. Bird, an attorney associated with (ICR), had written the act. Both sides called local educators. Judge Overton issued his ruling and an injunction permanently prohibiting enforcement of Act 590 on January 5, 1982. The state did not appeal his ruling.
The Fossil Record of Predation: An Overview of Analytical Methods
Authors: Kowalewski Michal
Published: June 2019

Paleontological research on predation has been expanding rapidly in scope, methods, and goals. The growing assortment of research strategies and goals has led to increasing differences in sampling strategies, types of data collected, definition of variables, and even reporting style. This methodological overview serves as a starting point for erecting some general methodological guidelines for studying the fossil record of predation. I focus here on trace fossils left by predators in the skeleton of their prey, arguably one of the most powerful sources of direct data on predator-prey interactions available in the fossil record. A critical survey of sampling protocols (data collecting strategy, sieve size, and sample size) and analytical approaches (predation intensity metrics, strategies for evaluating behavioral selectivity of predators, and taphonomic tests) reveals that various approaches can be fruitful depending on logistic circumstances and scientific goals of paleoecological projects. Despite numerous caveats and uncertainties, trace fossils left by predators on skeletons of their prey remain one of the most promising directions of research in paleoecology and evolutionary paleobiology.
Analyses of Coprolites Produced by Carnivorous Vertebrates
Authors: Chin Karen
Published: June 2019

The fossil record contains far more coprolites produced by carnivorous animals than by herbivores. This inequity reflects the fact that feces generated by diets of flesh and bone (and other skeletal materials) contain chemical constituents that may precipitate out under certain conditions as permineralizing phosphates. Thus, although coprolites are usually less common than fossil bones, they provide a significant source of information about ancient patterns of predation. The identity of a coprolite producer often remains unresolved, but fossil feces can provide new perspectives on prey selection patterns, digestive efficiency, and the occurrence of previously unknown taxa in a paleoecosystem. Dietary residues are often embedded in the interior of coprolites, but much can be learned from analyses of intact specimens. When ample material is available, however, destructive analyses such as petrography or coprolite dissolution may be used to extract additional paleobiological information.
Environmental determinism and archaeology. Understanding and evaluating determinism in research design
Authors: Arponen V. P. J. , Dörfler Walter , Feeser Ingo , Grimm Sonja , Groß Daniel , Hinz Martin , Knitter Daniel , Müller-Scheeßel Nils , Ott Konrad , Ribeiro Artur
Published: June 2019

With the emergence of modern techniques of environmental analysis and widespread availability of accessible tools and quantitative data, the question of environmental determinism is once again on the agenda. This paper is theoretical in character, attempting, for the benefit of drawing up research designs, to understand and evaluate the character of environmental determinism. We reach three main conclusions: (1) in a typical pattern of research design, studies seek to detect simultaneous shifts in the environmental and archaeological records, variously positing the former to have influenced, triggered or caused the latter; (2) the question of determinism involves uncertainty about the justification for the above research design in particular in what comes to biologism and the concept of environmental thresholds on the one hand and the externality of the drivers of transformation in human groups and societies on the other; (3) adapting the concepts of the social production of vulnerability and the social basis of hazards from anthropology may help to clarify the available research design choices at hand.
Genetic changes in ruminants: Historic trends and future prospects
Authors: McGuirk Brian
Published: June 2019

The major ruminant species, dairy and beef cattle and sheep, represent a rather heterogeneous group as regards genetic improvement, which to a large extent reflects their respective breeding structures. In the UK, the beef cattle and sheep industries still span many different breeds, have small herds/flocks, and have been relatively unaffected by agribusiness investment, and are assumed to have a traditional pyramid breeding structure, in which progress is determined by a small number of breeders. Recording of production information, which to date has focussed on terminal sire characteristics, is relatively recent, and until the use of across herd evaluations, genetic progress was probably limited. However in recent years there have been gains in both growth and muscling. There is little evidence or concern for undesired consequences in commercial flocks, partly because of the extensive use of crossbreeding in these industries, which exploits both breed complementarity and heterosis.

By contrast, the dairy industry is now dominated by purebred Holsteins. Increasingly breeding activities are both global in scope and dominated by a small number of large breeding companies. Because most traits of interest are only expressed in the female, improvement programmes have continued to focus on progeny testing, with test daughters in many herds. Most recording schemes and promotional activities emphasise production and type traits. The dairy industry is also notable for the publication of bull progeny test results, so that top bulls can then be used as sires of the next generation of by all companies. These bull evaluations now extend to international rankings.

Data from the US indicates continuing genetic progress for production traits in the Holstein, particularly since the 1960s, by when progeny testing had been established, frozen semen widely used, and adequate statistical procedures in place for evaluating bulls. Genetic progress is also evident for type traits. There is now growing concern and evidence of undesirable genetic changes in fertility, disease incidence and overall stress, despite improved nutrition and general management. Altering this situation will require both the recording of such traits and the use of that information by breeding companies, especially in sire selection.
Financing the livestock revolution in the developing world: givers and getters
Authors: Wilson R. T.
Published: June 2019

The call for products of animal origin increased dramatically in the Developing World in the last twenty years of the twentieth century. It is expected to double again in the first twenty years of the twenty-first century. The massive demand fuelled a concomitant increase in supply. This combination of events, being increasingly dubbed the “livestock revolution”, is certain to have an effect on the global environment. The changes that are occurring can be a force for good: helping to relieve human poverty, hunger and disease and being a driving force in intensification and improved efficiency of livestock production over wide areas.
The Use of the Hubble Space Telescope for Global Reference Frame Work
Authors: Hemenway P. D.
Published: June 2019

The Hubble Space Telescope (HST) will have the capability of making relative astrometric measurements with an accuracy of four to ten times better than similar ground based measurements. The instruments of choice will be the Fine Guidance Sensors (FGS’s). Details of the instrumentation have been given elsewhere (c.f. Jefferys, 1980). Each FGS consists of two interferometer detectors which look at a small aperture located within a larger field of view (FOV). The raw data consist of encoder readings, from “star selectors”, and error signals derived from the interferometer transfer functions. The star selector positions determine the position of the small aperture within the pickles. The precision is always less than 0.001 arcsec, with an expected accuracy of 0.002 to 0.003 arcsec per observation. Under optimum conditions, the best expected accuracy is 0.0016 arcsec per observation. An observation will consist of the relative positions of several objects in one pickle. Thus the highest accuracy observations will be relative observations within a relatively small field of view.
The Promise of Optical/IR Interferometry and Space Astrometry
Authors: Hughes J.A.
Published: June 2019

Referring to the “promise” of something is likely to imply that little has been accomplished. This is not true in the present case however. In optical interferometry, for example, there has been a steady development during the last decade or so after somewhat of a lapse subsequent to Michelson and Pease’s work some 65 years ago. Most of the work to date, however, has been directed towards the measurement of stellar diameters and binary stars and is hence not germane to the present topic of reference frames. What is required for the latter is the analog of the phase coherent interferometers used with such conspicuous success in radio interferometry. The important point is that such analogs are now available in both the optical and infrared (10u) wavelength regions.
Observation and Interpretation of Zeta Aurigae Stars
Authors: Chapman Robert D.
Published: June 2019

The ultraviolet observations of four Zeta Aurigau stars are reviewed. A, probably oversimplified, interpretation of the observations points to a straight forward connection between the spectral type of the B star and the amount of high temperature plasma in the systems.
The Angular Distribution of the Cosmic Background Radiation
Authors: Partridge R. B.
Published: June 2019

Crucial cosmological information is provided by the observed angular distribution (isotropy) of the cosmic microwave background radiation. This report treats the current status of searches for anisotroples in this radiation on all angular scales from 180° (the dipole component) to 6″. With the exception of the dipole component, only upper limits (at ~ 10-4 in ΔT/T) are available, yet these upper limits have played an important role in refining models of the early Universe and of the origin of structure within it.
Is the Upturn in the Source Counts Caused by Primeval Radio Galaxies?
Authors: Windhorst Rogier A.
Published: June 2019

During the last decade several deep surveys have been made with various aperture synthesis radio telescopes. At milliJansky levels important contributions were made with the WSRT 3 km array and the Cambridge One Mile Telescope. At sub-milliJansky levels surveys have been done with the VLA and the WSRT down to rms noise values of ~10 μJy.
Stellar Activity Cycles
Authors: Dravins Dainis
Published: June 2019

The main features of solar and stellar activity cycles are summarized, followed by a discussion of some outstanding observational problems for the future.
Starspots and Plages
Authors: Rodono Marcello
Published: June 2019

The general methodology to detect and study solar-like surface inhomogeneities on stars is presented. The most significant observations and typical results are discussed with particular emphasis on the inferred physical characteristics of starspots and plages and differential rotation, as compared to solar values. On account of the present observation and modelling limits, the need for complementary photometry and spectroscopy with space-born instruments is stressed, as well as the scientific relevance of the so-called solar-stellar connection studies in today’s Astrophysics.
On Active Stars, Coronal Loops, Magnetic Braking and All That
Authors: Vilhu Osmi
Published: June 2019

Coronal scaling laws and magnetic braking are discussed. The importance of future EUV and X-ray spectroscopy missions is emphasized.
The Concept of Young Populations
Authors: Lyngå Gösta
Published: June 2019

At the last General Assembly of the IAU, in Patras, we had a Joint Discussion about the evolution in old stellar populations in galaxies. Then, as will be the case today, the great emphasis was placed on star formation and stellar evolution, on luminosity functions and mass functions. Today our theme does not include the word stellar. This is intentional. The young populations we are going to discuss will to a large extent concern the gaseous component in galaxies. The gas and the dust may from some points of view be considered old. However, when it takes part in star formation we discuss it as a part of the young population.
Molecular Clouds in M51 and in the Galaxy
Authors: Friberg Per , Hjalmarson Åke
Published: June 2019

Studies of molecular clouds in nearby galaxies require high angular resolution. Ten arcseconds corresponds to 0.5 kpc at the distance of M51. Typical gigant molecular clouds (GMC:s) have a size of 5-30 pc (Solomon et al. 1985). However complexes of GMC: s (Superclouds) can be several hundred parsecs (Elmegreen 1985; Rivolo et al. 1985). The higest angular resolution achived in CO(J=1-0) line observations of external galaxies is 7” (Lo et al 1984,1985). The resolution problem can be eased by observing M31 with a distance of only ⋍ 690 kpc (10” corresponds to 34 pc), which has been done by Combes et al. 1977a,b; Boulanger et al. 1984; Ryden and Stark 1985; Stark 1985; Blitz 1985; Ichikawa et al. 1985. In M31 the CO emission is strongly concetrated to the spiral arms with a arm interarm ratio of ≥ 25 (Ryden and Stark 1985; Stark 1985). The emission is caused by many small clouds unresolved with present resolution together with some larger clouds. Streaming is observed to occur across the arms. Extragalatic studies have the advantage of being more easy to interpret in terms of arm interarm contrast, noncircular motion, and galatic structure. They also make possible studies of the mass fraction of gas as a function of radius in different morphological types of galxies. Answers to questions like “Do any relation exist between galaxy type and molecular abundance?” are very important for our understanding of galatic evolution.
Problems of Observing Nearby Galaxies Visually
Authors: Evans Robert
Published: June 2019

A review of progress made by amateurs in visual searching for supernovae in other galaxies reveals twelve discoveries made so far. A comparison between photographic and visual search methods reveals that each type of method has certain advantages and disadvantages. There are three minor problems and three major problems confronting visual searching. The main problem is the poor availability of good Survey photographs of many galaxies to amateurs and the restricted range of galaxies covered by available charts.
Some Possible Identification between Chinese Guest Stars and Supernova Remnents
Authors: Wang Z.R. , Liu J. Y. , Gorenstein P. , Zombeck M. V.
Published: June 2019

There are a lot of records concerning ancient Guest Stars (AGS) in Chinese historical books. Two catalogues of ancient nova or supernova were compiled (Xi 1955, Xi and Bo 1965, 1966) that listed 90 probable nova or supernova observed between 14 BC and 17 AD. The identify of AD. 1054 Guest star with Crab Nebula proved that the historical records are valuable to astrophysics. Since the discovery of the Crab pulsar in 1967, much attention has been paid to the relation between AGS and supernova remnants (SNR). Eight pairs of identification were suggested by Clark and Stephenson (1977). The number of SNR identified is two few to compare with the expectation from the frequency of supernova. In fact a lot of SNR or AGS have not been identified. It seems necessary, important and possible to look for further identification.
Supernovae in Flocculent and Grand Design Galaxies
Authors: McCall Marshall L. , Schmidt Fred H.
Published: June 2019

The arm structure of supernova host galaxies has been studied in order to ascertain whether or not spiral density waves have an impact on supernovae frequencies. The ensembles of Type I and Type II supernova hosts were found to contain identical fractions of grand design spirals consistent with the representations in control samples chosen without regard to supernovae production. The results suggest that a density wave does not greatly enhance the massive star formation rate per unit luminosity of a galaxy. Instead, star formation in most galaxies may be dominated by stochastic processes.
Gravitational Radiation by a Collapsing Rotating Stellar Core
Authors: Yunqiang Yu
Published: June 2019

The reduction of the ratio between specific angular momentum and mass (a/m) due to gravitational radiation has been investigated for a model of collapsing rotating stellar core in a post-newtonian scheme. Results show that if the initial value of the ratio is significantly greater than one, it tends towards one and if the initial ratio is nearly one, no sharp reduction happens as the core collapses to the neutron star or black hole size.
Hipparcos – Activities of the Input Catalogue Consortium
Authors: Turon C. , Crifo F.
Published: June 2019

The Input Catalogue Consortium (INCA) is in charge of selecting the 100 000 stars to be observed by Hipparcos. In this paper the organisation of the Consortium is described, and the technical requirements to be met by the Input Catalogue for optimal scientific return are summarised. The various tasks of this long collective work are then reviewed including the identification process of the proposed stars, the progressive construction of a list without redundancies, and the definition of the ‘survey’. The final selection of the stars which will be observed by Hipparcos is being made using a numerical simulation which takes into account the observing constraints of the satellite, and a parameter called the ‘pressure’ which is calculated for each star. Finally, the organisation of working groups set up to deal with special objects (multiple stars, variable stars, minor planets, stars in dense areas, and stars for linking the Hipparcos system to an extragalactic reference system) are described. New photometric and astrometric programmes undertaken for stars with unsatisfactory precision on magnitudes and/or coordinates, a major part of the Consortium’s work, will be presented elsewhere.
Hipparcos – Preparation of the Mission: Earth-Based Photometry
Authors: Grenon M.
Published: June 2019

The contribution of earth-based photometry to the preparation of the Input Catalogue for the Hipparcos mission is summarised for the pre-launch, the mission itself and the post-launch phases. An evaluation of the needs for new data and a progress report are also presented.
Hipparcos – Link with Extragalactic Reference Frames
Authors: Argue A.N.
Published: June 2019

The link of the Hipparcos Catalogue to an extragalactic reference system will be carried out on two time-scales: the first, coinciding with the duration of the mission, to provide data for immediate use by the data reduction consortia, and the second over a longer term to provide for subsequent reappraisal of the final Hipparcos catalogue. The first will be based on radio stars and on an indirect link to extragalactic objects by means of observations with the Hubble Space Telescope; for the second we hope for longer term programmes with the Hubble Space Telescope, together with a variety of ground-based links.
On the Absolute Energy Distributions of the Sun, of the “Solar Analogs” 16 CYG B, 16 CYG A, VB 64 and of Vega
Authors: Neckel H.
Published: June 2019

In 1984 Neckel and Labs (1984) published improved absolute solar radiation data which followed from an absolute calibration of the Fourier-transform-spectra (FTS) obtained by J. Brault at Kitt Peak. Fig. 1 shows two pages of that special solar spectrum atlas which served to derive the diverse published spectral data. The upper spectrum concerns the disk-center, the lower one the disk-averaged intensity. Both spectra are plotted in the same absolute scale (numbers on the left ordinate axis). The right ordinate axis refers to the full disk spectrum only; it yields the solar irradiance at 1 AU. These spectra, which extend from 3300 to 12500 Å and are stored on magnetic tape, allow an easy derivation of any desired spectral data; e. g. of the spectral averages for successive, rectangular passbands (10, 20 or 50 Å wide) or for any arbitrary passbands used by other observers. The maxima in successive passbands can be used to localize the level of the ‘continuum’ (dashed lines in Fig. 1).
A Search for Planetary-Mass Companions to Nearby Stars
Authors: Campbell Bruce
Published: June 2019

Nine of 18 stars observed with a high precision radial velocity technique show long term, low level variations which imply the presence of companions in the range of 1 to 10 Jupiter masses. These companions could represent the tip of the planetary-mass spectrum.
Brown Dwarfs in Binary Systems
Authors: Zuckerman B.
Published: June 2019

Searches for brown dwarf companions to known stars have revealed a number of tantalizing candidates.
Evolution of Cataclysmic Binaries
Authors: Paczyński Bohdan
Published: June 2019

The minimum period of hydrogen rich cataclysmic binaries at about 80 minutes is due to evolution driven by gravitational radiation. The nature of the gap between 2 and 3 hour periods is less clear. Magnetic braking may be responsible, but this would be in contradiction with the hibernating nova scenario. It is interesting that contact binaries of W UMa type are subject to little or no magnetic braking.
A New Progenitor Model of Type Ia Supernovae
Authors: Hachisu Izumi , Kato Mariko , Saio Hideyuki
Published: June 2019

A new progenitor model of Type la supernovae (SNe Ia) is proposed. The model consists of a carbon-oxygen white dwarf (0.8-1.2 M⊙) and a low-mass red giant star (0.8-1.5 M⊙) with a helium core (0.2-0.4 M⊙). When a red giant fills its inner critical Roche lobe and its mass transfer rate exceeds a critical value, a common envelope state is realized. Then the mass accretion rate onto the white dwarf, i.e., the mass transfer rate is tuned up to be Ṁ= 8.5 × 10−7 (MWD/M⊙-0.52) M⊙ yr−1, where MWD is the mass of the white dwarf. This rate is high enough to suppress the hydrogen shell flashes, but too low for carbon to be ignited off-center. When the carbon-oxygen core mass grows to the Chandrasekhar limit during the common envelope phase, a Type la supernova explosion is expected to occur.
Supernova 1987A: Light Curves and their Intepretation
Authors: Catchpole R M
Published: June 2019

The Type II supernova SN1987A which occurred in the LMC is the brightest and most completely observed supernova ever recorded. Objective prism and UBV observations were made of the blue supergiant progenitor Sanduleak −69°202 and indicate that the visual absorption lies in the range 0.4<AV<0.6. Furthermore, the distance to the LMC is known in absolute units with a precision of about ± 15% (m-M = 18.45, Feast 1988) which combined with the above data and subseguent photometric observations permits detailed comparison with theory.

Within 107 minutes of the Kamiokande 1MB neutrino event the region of the supernova was being observed by Albert Jones, although it was not until 0.8 days after the event that the supernova was officially discovered by Shelton. The first photoelectric observation was made at 1.1 days, by William Allen (1988) a New Zealand amateur. Other observations made during the first two days, have been conveniently tabulated by Arnett (1988). During this time the supernova steadily brightened in V, although theory predicts that it was rapidly fading bolometrically and cooling, after the intense heating that occurred when the shock wave reached the stellar surface about 3 hours after core collapse.