bluuebunny/crossref_metadata_2025_split huggingface dataset:
Meteorites from Comets? Recent Observational Developments
Authors: Campins Humberto 
Published: June 2019

AbstractAlthough most meteorites come from asteroids, some could originate from short-period comets. The identification of comet-asteroid transition object 4015 Wilson-Harrington as the first Apollo object known to have a cometary origin, confirms that short-period comets leave behind nonvolatile residues, from which meteoroids with low Earth-encounter velocities can originate. Studies of cometary fireballs suggest that some cometary meteoroids have high enough strengths to have survived atmospheric entry as cometary meteorites, which have either not been found or recognized. The presence of unequilibrated anhydrous silicates in cometary dust represents a significant difference between cometary material and CI and CM meteorites.
Laboratory Measurements of Light Scattering by Dust Particles
Authors: Combet Patrick P. , Lamy Philippe L. 
Published: June 2019

AbstractWe have set up an experimental device to optically study the scattering properties of dust particles. Measurements over the 8 — 174° interval of scattering angles are performed on a continuously flowing dust loaded jet illuminated by a polarized red HeNe laser beam. The scattering is averaged over the population of the dust particles in the jet, which can be determined independently, and give the “volume scattering function” for the two directions of polarization directly. While results for spherical particles are in good agreement with Mie theory, those for arbitrary particles show conspicuous deviations.
Coherent Backscatter Opposition Effect from Saturn Ring Particles and Their Regoliths
Authors: Horn L. J. , Nelson R. M. , Smythe W. D. , Hapke B. W. 
Published: June 2019

AbstractThe photometric phase curves of Saturn's A and B rings exhibit a sharp peak in reflectance when the phase angle approaches zero, commonly known as the opposition effect. Recent work has suggested that the width and amplitude of the opposition effect may be consistent with coherent backscattering from wavelength-sized grains which cover the surfaces of macroscopic ring particles.
Improvement of ion acceleration in radiation pressure acceleration regime by using an external strong magnetic field
Authors: Cheng H. , Cao L. H. , Gong J. X. , Xie R. , Zheng C. Y. , Liu Z. J. 
Published: June 2019

AbstractTwo-dimensional particle-in-cell (PIC) simulations have been used to investigate the interaction between a laser pulse and a foil exposed to an external strong longitudinal magnetic field. Compared with that in the absence of the external magnetic field, the divergence of proton with the magnetic field in radiation pressure acceleration (RPA) regimes has improved remarkably due to the restriction of the electron transverse expansion. During the RPA process, the foil develops into a typical bubble-like shape resulting from the combined action of transversal ponderomotive force and instabilities. However, the foil prefers to be in a cone-like shape by using the magnetic field. The dependence of proton divergence on the strength of magnetic field has been studied, and an optimal magnetic field of nearly 60 kT is achieved in these simulations.
Oscillation Reduction and Frequency Analysis of Under-Constrained Cable-Driven Parallel Robot with Three Cables
Authors: Hwang Sung Wook , Bak Jeong-Hyeon , Yoon Jonghyun , Park Jong Hyeon 
Published: June 2019

SummaryCable-driven parallel robots (CDPRs) possess a lot of advantages over conventional parallel manipulators and link-based robot manipulators in terms of acceleration due to their low inertia. This paper deals with under-constrained CDPRs, which manipulate the end-effector to carrying the payload by using a number of cables less than six, often used preferably owing to their simple structures. Since a smaller number of cables than six are used, the end-effector of CDPR has uncontrollable degrees of freedom and that causes swaying motion and oscillations. In this paper, a scheme to curb on the unwanted oscillation of the end-effector of the CDPR with three cables is proposed based on multimode input shaping. The precise dynamic model of the under-constrained CDPR is obtained to find natural frequencies, which depends on the position of the end-effector. The advantage of the proposed method is that it is practicable to generate the trajectories for vibration suppression based on multi-mode input-shaping scheme in spite of the complexity in the dynamics and the difficulty in computing the natural frequencies of the CDPR, which are required in any input-shaping scheme. To prove the effectiveness of the proposed method, computer simulations and experiments were carried out by using 3-D motion for CDPR with three cables.
Milk compositional quality and the rôle of forages
Authors: Thomas C. 
Published: June 2019

In most experiments in which the influence of forage to concentrate ratios on milk quality have been examined, the composition of the forage has been incidental to the purpose of the trial. Legumes have resulted in higher yields of milk than grasses of similar digestibility. However, these increases were a reflexion of higher outputs of protein and lactose, since the feeding of legumes resulted in lower contents of milk fat. Changes in the digestibility of forage have shown considerable variability in response, in terms of the concentration of milk solids. However, an increase in digestibility of forage has not resulted in decreases in the yield of fat and, further, the yield of protein has been increased.There is no indication that there is a requirement for ‘long hay’ to maintain milk quality and that a reduction in the chop length of silage has any influence on milk composition. However, the fine grinding of grass, which was the sole forage component of the diet, has caused a marked decrease in milk fat content. This effect was not apparent when finely ground and pelleted dried grass was used as a supplement but only in ad libitum feeding regimes.Attempts to increase the content of milk fat in May and June by the supplementation of grazed grass with small quantities of hay have had little influence on milk yield and fat content. A much greater effect was observed when grazing was restricted and silage offered ad libitum overnight. The increase in fat content may be overcome by a reduction in milk and protein yield.In general, the changes in milk composition have been small and this is likely to be a result of the high proportion of forage in the diets examined. The quantification of response in yield and content of fat and protein to changes in forage composition requires a change in approach. More emphasis should be given to the examination of the interaction between level or type of concentrate and the composition of the forage. Further, these trials should be accompanied by experiments to examine the effects of the dietary changes on the end products of digestion.
2.6 Packages for Intensive Farm Enterprises
Authors: Filmer D. G. 
Published: June 2019

The number of computer “packages” now being offered to farmers is growing rapidly and this paper does not present an exhaustive or critical account of these. Rather, it concentrates on packages offered by the feed trade to the intensive animal production sector of British agriculture. The paper will deal with the cattle, pig and poultry sectors, in that order, and then examine computer applications as they have developed, are now, and how they may become. Finally, the important criteria when considering the potential success of new computer packages will be described.Though some may consider the cattle sector to be less progressive than the pig and poultry sectors, as far as the application of the computer is concerned, cattle led the way. The earliest application was in the late 50's and early 60's, when the feed trade abandoned hand formulation of cattle feeds and provided one of the first commercial applications of linear programming—least-cost feed formulation. Though in those days, diet specifications were heavily constrained by raw material limits (for example, 5% fixed linseed cake and 5% copra cake in a well known high performance dairy feed), the effects were to reduce formulation costs by about 5% (£1 per ton in those days!). Cattle feeds were soon universally computer formulated, closely followed by pig feeds. Broiler and turkey foods remained as fixed formulae for some time but, as nutritional knowledge increased, these too fell into line. Currently, only a few specialized diets, such as baby pig foods, remain as fixed formulae. The remaining products now have very few raw material constraints left but many are tightly constrained on amino acids, undegradable protein, fatty acid levels and rations, various descriptions of energy components, etc.
2.7 Hill Resource Management
Authors: Eadie J. , Maxwell T. J. 
Published: June 2019

For the purpose of this paper ‘hill resources’ will be interpreted to mean the land resources of the hills and uplands. ‘Management’ will be assumed to include strategic and tactical decision making. It will further be assumed that the invitation is to discuss computers in animal production in relation to farming practice and not to research aimed at improving farming practice. In fact, computers will hardly be discussed at all. Computers are tools in this context and are aids to decision making. It seems much more likely that they will be more effectively used if we can be clear about decision making and its nature in relation to current knowledge and understanding and to the needs of farming systems based on the land resources of the hills and uplands.The official statistical deposition of hill sheep farms in Scotland includes reference to land resources; these farms have more than 90% of the land in rough grazings and less than 15% in crop. The definition includes reference to the allocation of man-days among sheep and cattle. The Scottish upland farm description also includes reference to land resources and there are, for example, constraints in the relationship of crop and rough grazing areas. Hill and upland farms in England and Wales come into the category known as Livestock Rearing farms, where distinction between hill sheep and upland farms is made on the distribution of man-days among cattle and sheep.
Effect of environmental temperature on brown adipose tissue development in the neonatal lamb
Authors: Darby C. J. , van de Waal S. , Lomax M. A. , Symonds M. E. 
Published: June 2019

A major financial and welfare problem is the loss of 1 to 4 million lambs annually in the United Kingdom (Slee, 1979) with many of these deaths being caused by failure of the lamb to maintain normal thermoregulatory responses in the cold. This may be associated with a change in the response to cold exposure from non-shivering thermogenesis (NST) to shivering thermogenesis (ST) as brown adipose tissue (BAT) is replaced by white adipose tissue over the first 2 weeks of life in the lamb (Symonds, Andrews and Johnson, 1989).It has been shown that environmental temperature can affect BAT development in the lamb (Gemmel, Bell and Alexander, 1972) and calf (Casteilla, Champigny, Bouilland, Robelin and Riquier, 1989) but it is not known what effect this has on the thermogenic capacity of BAT or how it may alter the ability of the lamb to thermoregulate.This study investigated the effect of artificially rearing lambs at warm or cold ambient temperatures on the thermogenic capacity of BAT and the extent to which metabolic rate and the ability to respond to warm and cold challenges was altered by these treatments over the first 9 days of life.
6.15 The Effects of Soil Cobalt on Rumen Vitamin B12 Synthesis
Authors: McDonald P. , Suttle N. F. 
Published: June 2019

The high level of cobalt (Co) in soil relative to herbage means that soil accidentally ingested with herbage may constitute the larger source of the element for vitamin B12 synthesis by rumen microbes.A continuous culture simulation of rumen fermentation (Rusitec: Czerkawski and Breckenridge. 1977) was used to determine the extent to which soil Co was used for microbial vitamin B12 synthesis. A low Co hay (0.044 mg/kg DM), 7.25 g DM/day, was “fed” to each of four vessels for a period of 8 days to provide resting values for vitamin production. A chalk, a sand, a clay or a loam, with Co concentrations ranging from 0.70 to 64.5 mg/kg DM (see Table 6.15.1), were then added at 0.70 g/day, to the hay in separate vessels each morning for 14 days. For a further period of 10 days, the hay in two vessels was supplemented with either chalk or loam at 1.4 g/day. Daily vitamin B12 production was measured by analysis of each vessel's effluent for cobalamin (cbl.), using a modification of the method of Green (1980). Vitamin B12 analogue production was assessed from the Lactobacillus leichmannii microbial assay of the effluent. All vessels produced a “roughage” fermentation (acetate c. 50% and propionate c. 20% of the total volatile fatty acids) with the soil supplements.
8.4 The Effect of the Quantity and Composition of Ruminally Degraded Nitrogen on Microbial Nitrogen Synthesis and Diet Formulation
Authors: Beever D. E. , Cottrill B. R. , Osbourn D. F. 
Published: June 2019

Recent proposals (ARC, 1980) have clearly identified the need to supply adequate ruminally degradarle nitrogen (RDN) if rumen microbial protein yields are to be optimized and they provide a basis on which the required quantities of RDN can be calculated. However, apart from the suggestion that urea is used with only 80% of the efficiency of degraded protein N as a source of RDN in the synthesis of microbial protein, the present scheme fails to qualify the RDN composition (i.e. protein N (PN) vs. NPN) most likely to promote optimal microbial synthesis.Cottrill, Beever and Osbourn (1982) examined the isonitrogenous supplementation of maize silage fed to growing calves with four different NPN:PN ratios in the supplement and showed a 29% increase in total duodenal amino acid (DAA) flow at the first increment of PN (fish meal). Of this increase, almost 87% could be accounted for by an increased duodenal microbial protein (DMP) flow. Higher levels of PN inclusion did not promote any further increases in DAA, despite increases in undegraded dietary protein (UDP) flow, due to a significant reduction in DMP flow. From these data, a further examination of total RDN supply and its composition in relation to MP synthesis was undertaken and the results are presented in this paper.
In vitro techniques to replace in vivo methods for estimating amino acid supply
Authors: Hvelplund T. , Weisbjerg M. R. 
Published: June 2019

Abstract
Expressing the protein value of a food involves measurements of several of its characteristics. Many in vivo studies have shown, that the protein degradability in the rumen varies substantially both between and within foods and therefore estimation of protein degradability in the rumen is an important task in protein evaluation. The most common method used has been the in situ (in sacco, nylon bag) method but many in vitro methods have been introduced and are based on use of either buffer solubility, chemical methods, rumen fluid or enzymes. None of these in vitro methods has proven to be of general use. In further development of in vitro methods as well as the in situ method a major problem is lack of a set of samples with a ‘true’ in vivo degradability which can be used for calibration of alternative methods. Microbial protein synthesis in the rumen has to be related to food characteristics which can be analysed easily. In vitro methods which can predict organic matter digestibility in foods are available and can be used to predict microbial protein synthesis in the rumen. Intestinal digestibility of undegraded dietary protein varies substantially both between and within foods and easy methods to estimate intestinal digestibility are therefore essential. The mobile bag method is easy to use and seems to give reliable results on most foods but requires access to duodenal cannulated animals which prevents this method from being routine. Alternative in vitro methods have been developed but further research is required for validation of these methods on a wide range of foods before they can be accepted for general use.
In vitro techniques for modelling rumen transformation and syntheses
Authors: Sauvant D. , Broudiscou L. , Giger-Reverdin S. 
Published: June 2019

Abstract
There are two major ways to model the microbial activity in the rumen. The first is the material or physical modelling with in vitro systems and the other is mathematical modelling with sets of equations.The evaluation of the ability of in vitro devices is to mimic in vivo ruminal digestion needs to perform first a typology of the most known and published in vitro procedures. This typology is aimed at clustering them according to their basic function (batch or continuous), to their major targets (studies of food degradation, of microbial proteosynthesis, of volatile fatty acid (VFA) production and profile, of gas production and composition, of outflow influences, of interactions between microbe species … also of prediction of intake of food nutritive value), to their level of time integration (cumulative at a given time or kinetic values), to their actual validity to simulate one or several items of ruminal digestion. Another key of typology of in vitro procedures is also the nature of the active substance, microbes or enzymes.Rumen mathematical modelling can be variously used in connection with in vitro and in vivo experimentations. At least three main targets can be pursued in this perspective:To model in vivo ruminal digestion. This aspect already has a long history because the first actual mechanistic model of whole rumen digestion was that of Baldwin et al. (1970). Since this date around a tenth of whole rumen models were proposed. Their current limits are those of the knowledge on rumen digestion: proteosynthesis, VFA production, nutrient absorption, liquid and particle outflows. As far as we are aware, none of these published rumen models was checked against in vitro data. One reason could be that some of them were more or less built from in vitro data.To model in vitro devices. Surprisingly no such specific model seemed to be published until now. In our opinion it is urgent to develop such models because they could be highly useful: to compare analogies and discrepancies between the various in vitro procedures; to try to build a unique model of in vitro ruminal digestion which could be parameterized according to the type of device; to elucidate intrinsic properties of micro-organisms.To model both in vitro and in vivo digestion. This way is likely to be the most difficult but it is also potentially the most fruitful. Effectively the use of an intermediate mathematical model of the rumen seems to be a priori the best way to check the major areas of analogy and discrepancy between in vivo and in vitro events. Thus this approach could be an objective mean of validation of in vitro studies.
Emerging feed legislation and related issues
Authors: Millar Keith 
Published: June 2019

According to David Byrne, EU Commissioner for Health and Consumer Protection (DG SANCO), ‘Strengthening rules on the safety of animal feed is one of the cornerstones of the EU's food safety strategy’. The main EC developments affecting animal feed can be summarised under the following headings:•General Food Law Regulation•Proposal for Feed Additives Regulation•Proposal for Feed Hygiene Regulation•Positive List of Feed Materials•Official Food and Feed Controls•GM Food and Feed
Autofom – a new and improved technology for the UK pig industry?
Authors: Haighton M.W. 
Published: June 2019

No matter how specific an abattoir's requirement, and no matter how many different incentives are offered to pig producers to encourage them to send in a particular sort of carcase, the bottom line is that pigs do not come like nuts and bolts.Variable factors such as genetic make–up, nutrition, production system, feeding regime, environment and disease status all combine to result in decreasing the uniformity of the carcases found inside the chillers of UK abattoirs. This variation not only occurs in carcases from different units but also between carcases produced on the same unit, and it’s not uncommon to find a wide spread of carcase weights, lengths and fat deposition within one batch of pigs.This lack of uniformity provides a headache for all pig processors for the sole reason that, over the years, their customers have become a lot more specific with their meat requirement. For example, several years ago a third party processor would buy 500 loins of pork at a premium price for pork chop production.
Longitudinal study of adverse behaviour of undocked pigs in two different housing systems
Authors: Van de Weerd H. A. , Docking C. M. , Day J .E. L. , Breuer K. , Edwards S. A. 
Published: June 2019

AbstractThe development of adverse behaviour in group–housed growing/ finishing pigs with intact tails was studied in a straw–flow housing system and in a part–slatted system with a commercial enrichment object. Food intake, body weight and behaviour were monitored over the finishing period, with tail biting outbreaks defined as an occasion where three or more pigs within a group had freshly damaged tails and tail biting behaviour was ongoing. Data from the two systems were analysed to identify tail–biting outbreaks and behavioural changes over time. Levels of pig manipulation were higher in the part–slatted system. Over time, pigs in both systems showed reduced interest in the enrichment provided, but not in each other. Despite the presence of the enrichment device, tail biting occurred in all groups in the part–slatted system, but only 1/12 groups in the straw–flow system. The amount of time occupied by manipulation of the enrichment provided was very significantly higher for straw than for the commercial object. Better design of enrichment strategies is therefore needed and should be based on species–relevant requirements.