bluuebunny/crossref_metadata_2025_split huggingface dataset:
Anomalous Pulsation of Field RR Lyrae Variables: Photometric and Spectroscopic Study of CM Leo, BS Com, and CU Com
Authors: Bragaglia A. , Clementini G. , Fabrizio L. Di , Tomaso S. Di , Merighi R. , Tosi M. , Evans I. , Sneden C. , Wilhelm R. , Smith H. 
Published: June 2019

AbstractWe present results on three presumed “anomalous” RRab stars: one is found to be an RRc variable, and the two others need further study.
A New Look at the Blazhko Effect in RR Lyrae Stars with High-Quality Data from the MACHO Project
Authors: Kurtz D. W. , Alcock C. , Allsman R. A. , Alves D. , Axelrod T. S. , Becker A. C. , Bennett D. P. , Cook K. H. , Freeman K. C. , Griest K. , Lehner M. J. , Marshall S. L. , Minniti D. , Peterson B. A. , Pratt M. R. , Quinn P. J. , Rodgers A. W. , Stubbs C. W. , Sutherland W. , Tomaney A. , Welch D. L. ,   The MACHO CoUaboration
Published: June 2019

AbstractWe present the first results of the analysis of 22 Blazhko stars. We find: 1) Blazhko RRab stars that are nearly pure amplitude modulators; 2) Blazhko RRab stars that have both amplitude and phase modulation; 3) A Blazhko RRab star that has an abrupt period change; 4) Proof of the Blazhko effect in RRc stars. Our data show the character of the amplitude and phase modulations of the light curves over the Blazhko cycles far better than has been previously possible.
Frequency Analysis of the RRc Variables of the MACHO Database for the LMC
Authors: Kovács G. , Alcock C. , Allsman R. , Alves D. , Axelrod T. , Becker A. , Bennett D. , Clement C. , Cook K. H. , Drake A. , Freeman K. , Geha M. , Griest K. , Kurtz D. W. , Lehner M. , Marshall S. , Minniti D. , Nelson C. , Peterson B. , Popowski P. , Pratt M. , Quinn P. , Rodgers A. , Rowe J. , Stubbs C. , Sutherland W. , Tomaney A. , Vandehei T. , Welch D. L. ,   The MACHO Collaboration
Published: June 2019

AbstractWe present the first massive frequency analysis of the 1200 first overtone RR Lyrae stars in the Large Magellanic Cloud observed in the first 4.3 yr of the MACHO project. Besides the many new double-mode variables, we also discovered stars with closely spaced frequencies. These variables are most probably nonradial pulsators.
RR Lyrae Variables in the Globular Cluster M55. The First Evidence for Nonradial Pulsations in RR Lyr Stars
Authors: Olech A. , Kaluzny J. , Thompson I. B. , Pych W. , Krzemiński W. , Schwarzenberg-Czerny A. 
Published: June 2019

AbstractWe present the results of a photometric study of RR Lyrae variables in the field of the globular cluster M55. We have discovered nine new RR Lyrae stars, increasing the number of known variables in this cluster to 15 objects. Five of the newly discovered variables belong to Bailey type RRc and two to type RRab. Two background RRab stars are probable members of the Sagittarius dwarf galaxy. Fourier decomposition of the light curves was used to derive basic properties of the present sample of RR Lyrae variables. From an analysis of the RRc variables we obtain a mean mass of M = 0.53 ± 0.03 M⊙, luminosity log L = 1.75 ± 0.01 L⊙, Teff = 7193 ± 27 K, and helium abundance Y = 0.27 ± 0.01. We also derive the value of the color excess for M55 to be equal to E(B − V) = 0.11 ± 0.03. We estimate the values of the visual apparent distance moduli to be 13.65 ± 0.11 from RRab stars and 13.91 ± 0.08 from RRc stars. The light curves of three of the RRc variables exhibit changes in amplitude of over 0.1 mag on time scales of less than a week, rather short for the Blazhko effect, but with no evidence for another radial pulsational frequency. However, we do detect other periodicities which are clearly visible in the light curve after removing variations with the first overtone radial frequency. This is strong evidence for the presence of nonradial pulsations, a behavior common for 8 Scuti stars, but not yet observed among RR Lyr variables.
Blazhko Effect and Magnetic Field in RR Lyrae
Authors: Chadid M. , Gillet D. , Kolenberg K. , Aerts C. 
Published: June 2019

AbstractThe recent detection of a frequency splitting around the pulsation frequency and its harmonics points towards the magnetic model to explain the Blazhko effect. Here we show that it is urgent to confirm with modern observational techniques the existence of the magnetic field in RR Lyrae.
Nonlinear Pulsations of Convective Stellar Models
Authors: Buchler J. Robert 
Published: June 2019

AbstractWe review the numerical modeling of the nonlinear pulsations of classical variable stars with hydro-codes that include the effects of turbulent convection. Despite their simplicity these turbulent convective recipes appear to remove many of the difficulties that radiative codes faced. In particular, the numerical modeling of double mode pulsations has become possible.
Convection-Induced Oscillatory Thermal Modes in Red Giants: A New Type of Stellar Oscillation
Authors: Wood P. R. 
Published: June 2019

AbstractA new type of oscillatory thermal mode has been found in red giant stars. The modes arise because of the interaction of stellar oscillations and convective energy transport. All the modes found are highly damped. However, it is possible that a different treatment of convection could lead to unstable modes capable of explaining the long secondary periods observed in some red giants.
The Newly-DiscoveredγDoradus Variables
Authors: Kaye Anthony B. , Handler Gerald , Krisciunas Kevin , Poretti Ennio , Zerbi Filippo M. 
Published: June 2019

AbstractIn this contribution we describe a new class of pulsating stars, the prototype of which is the bright, early F-type dwarf,γDoradus. These stars typically have between 1 and 5 periods ranging from 0.4 to 3 d with photometric amplitudes up to 0ṃ1 in JohnsonV. The mechanism for these observed variations is high-order, low-degree, nonradial, gravity-mode pulsation. A recent theoretical development describing a proposed driving mechanism for these new variables is discussed.
Results and Future Uses of Heterodyne Spatial Interferometry at 11 Microns
Authors: Sutton Edmund C. 
Published: June 2019

AbstractHeterodyne spatial interferometry at a wavelength of 11 microns has been used to examine properties of circumstellar dust shells. Among the objects which have been observed are several M-type supergiants and Mira variables as well as several peculiar infrared stars. These measurements provide information on the temperature and spatial distribution of dust grains. Possible future developments in heterodyne interferometry include longer baselines for higher resolution and the use of larger telescopes for greater sensitivity.
On Astrometric Applications Of The Very Long Baseline Amplitude Interferometer
Authors: Currie Douglas G. 
Published: June 2019

AbstractThe possible use of the Very Long Amplitude Interferometer in several programs of astrometric measurements and observations will be described. These programs include short-arc or differential astrometry, large-arc astrometry for zonal corrections in the FK-4 datalog and absolute astrometry primarily for the study of earth rotation. The basic techniques for these different applications, the relevant measurement precision and accuracy, and the related signal-to-noise ratios will be discussed. The role of the atmosphere and the critical atmospheric parameters, as they relate to the astrometric measurements, will be discussed including the atmospheric delay correction by the use of two separate wavelengths. The role of various types of ground motion i.e. seismic disturbance for the different types of astrometry will be discussed and data presented as to the possible effects. Measurements on the stability of equipment will also be included. In addition the use of a two color refractometer for site surveys and the evaluation of gravity waves in the atmosphere will be considered. The procedure for references to the vertical (which is required for earth rotation) will be considered.
Searching Evidences for Spiral Shocks in the Quiescent Accretion Disk of U Gem
Authors: Neustroev V. V. , Chavushyan V. , Valdés J. R. 
Published: June 2019

AbstractWe find that the quiescent accretion disk of U Gem has a complicated structure. Along to the bright spot originating in the region of interaction between the stream and the disk particles, there are also explicit indications of spiral shocks. The Doppler map and the variations of the peak separation of the emission lines are indicative.
The effect of changes in the payment scheme on individual farmers
Authors: Warren M. E. , Amies S. J. , Robinson T. G. 
Published: June 2019

The changes in the payment scheme proposed by the Milk Marketing Board from 1 April 1984 cover a number of issues relating to compositional quality, seasonality of pricing and the monthly distribution of production. Although the changes in total must be financially self-balancing on a national basis, the effect on individual farms may be significant.A computer program has been used on the records from a number of farms to investigate the effect of the changes, separately and together, on annual and monthly income from milk. The effects on three herds were as follows.Herd 1 was a Jersey herd that showed an overall increase in income per cow, due mainly to the higher price of protein. Herds with a high protein to lactose ratio in the milk will stand to gain from the new price of protein.Herd 2 was a Friesian/Holstein herd with a low protein and low milk fat content in the milk. The herd was also calving seasonally and had a low output of milk during August and September. A substantial decrease in income of approximately £29 per cow was due principally to the low protein to lactose ratio but also to the low fat content and the seasonal pattern of milk production on the farm.
Remarks on donor support to animal production research
Authors: Ndiritu C. G. 
Published: June 2019

AbstractIn spite of being the home of a significant number of the world's flocks and herds, the productivity per head and per ha of the livestock sector in sub-Saharan Africa continues to be so low that the total output does not meet the domestic demand. Indeed, there is evidence that there has been little or no increase in output of animal products in this region during the 1980s. On the other hand, the human population has increased at a rate of more than 3% per annum. This has been associated with an escalating demand for food thus adding pressure on natural resources which are already threatened.There is therefore a need for technical innovations to increase output of livestock products to at least a level of self-sufficiency. This increase must be obtained in a manner which is consistent with protection of the environment and conservation of natural resources for sustainable performance.In this endeavour to develop technologies to support the livestock industries, developing countries of Africa are faced with inadequate resources to carry out research programmes, addressing a multiplicity of produciton problems. Towards this end, the donor countries have contributed resources including capital goods, technical assistance, operational finance for agreed projects and manpower development. However it is important that the national scientists are involved in the conceptualization, formulation and implementation of research programmes. The donor inputs are therefore expended in execution of projects generated by the local personnel. In this connexion, it is hoped that the level of support will be increased and sustained for a reasonable period to bear impact at the farm level. However it should be noted that research alone cannot bring about increase in output of meat and milk, etc. Rather the new technology from research is one of the inputs which must be mixed with other inputs to improve production.
Use of crop residues and agro-industrial by-products in ruminant production systems in developing countries
Authors: Jayasuriya M. C. N. 
Published: June 2019

AbstractRuminant production systems in developing countries could be classified into three categories: the extensive systems, systems incorporating arable cropping and systems integrated with tree cropping. Systems have evolved in response to the agro-ecological environment, the availability and type of land, nature of cropping patterns, frequency and intensity of cropping, area of uncultivated land and animal species and animal numbers.Smallholder livestock farmers in most developing countries appear to have adopted a mixed system that incorporates the traditional extensive system and the system that combines arable cropping with livestock. Both in Africa and in Asia, livestock production is an important component of traditional agriculture, complementing arable cropping. Livestock utilize existing food resources such as communal grazing lands which are marginal for arable cropping, crop residues and agro-industrial by-products. Besides supplying meat and milk, organic manure and draft power, livestock are an investment and an insurance against crop failure.Crop residues and agro-industrial by-products are a major source of nutrients for ruminant livestock in developing countries, especially during periods of fodder shortage. Despite the large research effort on upgrading crop residues in recent years, there has been little improvement in the utilization of crop residues in developing countries. Reasons for this are many but include, the absence of detailed production patterns of crop residues within countries, including when and where they are produced, the difficulties of transporting and storing crop residues, inappropriate technology and the near absence of extension services.Both in the African and Asian continents, smallholder farmers who rear livestock for supplementary income are rather reluctant to change their traditional practices, when new technologies call for extra labour, time and capital, since the methods may be too demanding in relation to the benefit produced. The more likely application of any new technology will be with larger-scale operations where benefits are clearer and sufficiently large to warrant the extra efforts.
Resource requirements for draught animal power
Authors: Pearson R. A. 
Published: June 2019

AbstractThe place of draught animal power on farms in tropical agriculture is discussed. In some areas of the world draught animal power is traditional, in others it is a relatively new technology. There are situations which fall between the two, but when thinking about resolving technical and more particularly socio-economic constraints it is often useful to be aware of these two categories. While some of the problems encountered are universal, other problems can be more specific to a particular situation or country.In this paper some of the issues are discussed. These include the energy requirements for work, the provision of food, particularly in ‘new’ draught animal areas, the consequences of using draught cows in traditional systems, disease treatment and two examples of country specific problems. In some cases strategies to cope with these issues are available, largely as a result of research, in others it is apparent that more information is required.
Fibrous diets for pigs
Authors: Close W. H. 
Published: June 2019

AbstractThis paper reviews current knowledge on the feeding of fibrous foods to pigs. It attempts to explain why fibrous foods differ in their nutritional value by defining what constitutes ‘dietary fibre’ and by discussing aspects associated with digestion, absorption, fermentation and metabolism in the gastro-intestinal tract. Fibrous diets can contribute proportionately up to 0-3 of the energy requirements of the animal, but there are significant reductions in the digestibility of all nutrients. There is a reduction in energy intake with increase in fibre intake, and this reduces both growth and food utilization efficiency; carcasses may, however, be leaner. Sows are better able to utilize fibre than weaned or growing/ fattening pigs and there may be improvements in reproduction as well as health and welfare benefits. Nutritive values can be improved by processing and deficiencies overcome by the use of synthetic and other materials. There is considerable potential to incorporate fibrous and by-product materials into feeding strategies for pigs in developing countries, with both economic and productive advantages.
Selection and breeding strategies for sustainable livestock production in developing countries, with particular reference to dairy cattle production
Authors: Peters K. J. 
Published: June 2019

AbstractBreeding strategies for sustainable livestock production in developing countries are discussed with reference to breeding objectives in more uniform environments of temperate regions and to those in stressful and highly variable environments of the tropics. The relative importance of breeding objectives to be based not on single performance traits but also on fitness traits is discussed in relation to production efficiency. With particular reference to breeding strategies for dairy production the following aspects are referred to: assessment of scope for performance improvement; the rôle of local breeds in stressful environments; the need for potential assessment and options for breed improvement; the use of exotic breeds; and the need for comparative field performance test as part of improvement schemes.
Can genetics deliver?
Authors: Webb J 
Published: June 2019

For the past thirty years pig genetics has enjoyed a clear message from its end–users: reduce backfat and production costs. During that period, genetics, nutrition and health have together delivered improvements of some 60% in lean growth rate and feed efficiency. To compound the recent misfortunes of the UK industry, meat is now slipping further behind everything else on the supermarket shelf in quality, uniformity, and above all predictability. The notion of quality stretches far beyond the product into responsibility for animal welfare, human nutrition and food safety.The industry's present dilemma arises from five factors:1.uncertain market conditions with cyclical profitability2.poor communication of what constitutes good quality3.payment systems that no longer reflect what the market requires4.independent management of the different steps in the pork value chain5.possible effects of animal health on quality and uniformity.Meanwhile the understanding of gene function and the ability to detect potentially useful genetic variation is gathering momentum. This paper examines the role that genetics can play in adding value, reducing risk and differentiating the product, from the perspective of a large vertically coordinated pork producer.
Environmental sustainability – legislation, policy drivers and perks
Authors: Brewer Alan 
Published: June 2019

In this context, legislation to protect the environment is taken to mean that affecting water, soil and air and excludes wildlife, habitats and bio–diversity. In practice, of course, resource protection impacts on wildlife, habitats and bio–diversity as well as on human health.Agriculture is responsible for over 70% of nitrates and over 40% of phosphates in English waters (Defra, 2002). Elevated levels of these nutrients can contribute to eutrophication of marine and freshwater and cause ecological harm. Agriculture is also responsible for around 80% of UK ammonia emissions to air, although the contribution from pig farming is about 9% (Defra 2002). This contributes to acid rain that can damage forests, lakes and rivers; and it adds nitrogen to nutrient–poor soils (e.g. heathland) that can change the type of vegetation. And each year there are many complaints to local authorities about odours from agricultural premises (Defra 2002).There are a number of pieces of legislation that affect or will affect pig production that seek to avoid, limit or minimise emissions to the environment: these include the Nitrates Directive, Integrated Pollution Prevention and Control (IPPC) Directive (larger pig units), Water Framework Directive, Control of Pollution (Silage, Slurry and Agricultural Fuel Oil) Regulations 1991, Animal By–products Regulation, and the proposed Waste from Mines and Quarries and Agricultural Premises (England and Wales) Regulations that will implement the Waste Framework Directive for agriculture.
Animal awareness
Authors: Kendrick K. M. 
Published: June 2019

AbstractThe problem of demonstrating that animals are consciously aware of their environment or themselves in a similar manner to ourselves has proved to be a relatively intractable one since we have mainly been constrained to rely upon observation of an animal’s behaviour as an index of its awareness. It can usually be argued that even complex behaviours need not necessarily involve an animal being aware of either environmental cues or its response to them. Indeed, simple organisms or computers can perform complex responses to environmental cues when they are clearly not aware of them in the sense that we are ourselves. What can particularly distinguish conscious awareness from simple stimulus-response guided behaviour is the ability of an animal to experience some form of emotional response to an environmental cue or to its own actions. In this review I will summarize some of our experiments on sheep which show that the way their brains process visual and olfactory social and non-social cues from the environment is integrally related to and organized by the emotional significance of what is perceived. I will also argue that the way their brains process complex social stimuli from the environment in order to recognize individuals is very similar to ourselves although these processes are very strongly influenced by changes in their motivational state. From these observations I will maintain that sheep are almost certainly capable of conscious awareness of their environment although perhaps this awareness is mainly restricted to present events and needs with a limited capacity to reflect on the past or future.
The biology of harpacticoid copepods in the meiofauna of shallow subtidal sands
Authors: Hardy B. L. S. , Barnett P. R. O. 
Published: June 2019

SynopisAn account is given of the benthic harpacticoid copepods of a medium grade subtidal sand at a depth of 8–5 m (below chart datum) off the Ayrshire coast at Hunterston. It is the first account of seasonal changes in subtidal harpacticoids in the Firth of Clyde.Most of the population is restricted to the top 1 cm layer of sand and this is considered to be related to food availability. There were considerable variations in total densities with largest numbers occurring in late June, as seawater temperatures increased rapidly towards the summer maxima.Two species examined in detail, Asellopsis hispida and Harpacticus flexus each had one distinct period of reproduction during the year. Gravid females appeared first during the coldest months (January and February) followed by large numbers of copepodites from late April to June, culminating in large numbers of adults in June. Adult males clasped female stages only in May and June, after the main period of egg production. It is thought that viable sperm is carried by the adult females for about six to seven months, supposedly until the next period of egg production the following year. Adults of Harpacticus flexus are thought to be an important source of food for juvenile and small fish, particularly during July.