bluuebunny/crossref_metadata_2025 huggingface dataset:
Reaction of 3,3,5,5‐Tetraphenyl‐1,2,4‐trithiolane with Pt0(bisphosphane)(η2‐nbe) Complexes Bearing Bridged Bisphosphane Ligands with Various Bite Angles
Authors: Weisheit Thomas , Petzold Holm , Görls Helmar , Mloston Grzegorz , Weigand Wolfgang
Published: March 2009

A series of Pt0(η2‐nbe) complexes [nbe = norbornene (bicyclo[2.2.1]hept‐2‐ene)] bearing bridged bisphosphane ligands with various bite angles (5a–c) was treated with 3,3,5,5‐tetraphenyl‐1,2,4‐trithiolane (1) at 50 °C in a toluene solution. These reactions resulted in the formation of the appropriate dithiolato complexes 6a–c as well as the η2‐thioketone complexes 7a–c with respect to the 31P{1H} NMR spectroscopic data. All isolated complexes were fully characterized. Kinetic investigations using 31P{1H} NMR spectroscopy revealed first‐order kinetics in 1, pointing to the known cycloreversion of 1 as the initial and rate‐determining step for these reactions. The formation of dithiolato complexes 6a–c suggests 1,3‐dipolar electrocyclization of diphenylthiosulfine (3) to diphenyldithiirane (4) in solution. On the basis of these results a plausible mechanism for the overall reaction is developed.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Variational generation of prismatic boundary‐layer meshes for biomedical computing
Authors: Dyedov Volodymyr , Einstein Daniel R. , Jiao Xiangmin , Kuprat Andrew P. , Carson James P. , del Pin Facundo
Published: March 2009

Boundary‐layer meshes are important for numerical simulations in computational fluid dynamics, including computational biofluid dynamics of air flow in lungs and blood flow in hearts. Generating boundary‐layer meshes is challenging for complex biological geometries. In this paper, we propose a novel technique for generating prismatic boundary‐layer meshes for such complex geometries. Our method computes a feature size of the geometry, adapts the surface mesh based on the feature size, and then generates the prismatic layers by propagating the triangulated surface using the face‐offsetting method. We derive a new variational method to optimize the prismatic layers to improve the triangle shapes and edge orthogonality of the prismatic elements and also introduce simple and effective measures to guarantee the validity of the mesh. Coupled with a high‐quality tetrahedral mesh generator for the interior of the domain, our method generates high‐quality hybrid meshes for accurate and efficient numerical simulations. We present comparative study to demonstrate the robustness and quality of our method for complex biomedical geometries. Copyright © 2009 John Wiley & Sons, Ltd.
Oral rapamycin reduces tumour burden and vascularization in Lkb1+/− mice
Authors: Robinson James , Lai Cecilia , Martin Alison , Nye Emma , Tomlinson Ian , Silver Andrew
Published: March 2009

Patients with Peutz–Jeghers syndrome (PJS) are affected by hamartomatous intestinal polyposis and increased risk of cancers in multiple organs caused by germline mutations in the tumour suppressor gene LKB1. Murine models that recapitulate aspects of PJS have been created. Here we examine the therapeutic effect of rapamycin, a macrolide with anti‐tumourigenic and anti‐angiogenic properties, in reducing tumour incidence in a large cohort of Lkb1+/− mice. To study the influence of early intervention, the animals were dosed with rapamycin from the age of 8 weeks, well before the onset of polyposis. These mice continued to receive the drug, which was well tolerated, throughout their lives. At sacrifice, we observed a reduction in gastric tumour burden in the rapamycin‐treated mice (p = 0.0001) compared with age‐ and sex‐matched controls. Treated animals also have a lower number of polyps per mouse than controls. In the polyps from the treated mice, phosphorylation of ribosomal p70 S6 kinase was maintained, while the phosphorylation of AKT at serine‐473 was elevated, suggesting that mTORC1 function is maintained at this dosage. Despite this, a significant reduction in microvessel density was seen in polyps from the rapamycin‐treated mice compared to those from the control mice (p = 5 × 10−5), suggesting that the anti‐angiogenic effect of rapamycin played a role in polyp reduction. Overall, we demonstrated that prolonged oral administration of rapamycin from an early age is effective in lowering tumour burden in the Lkb1+/− mice without evident side effects. Copyright © 2009 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Identification of biomarkers for risk stratification of cardiovascular events using genetic algorithm with recursive local floating search
Authors: Zhou Xiaobo , Wang Honghui , Wang Jun , Wang Yuan , Hoehn Gerard , Azok Joseph , Brennan Marie‐Luise , Hazen Stanley L. , Li King , Chang Shih‐Fu , Wong Stephen T. C.
Published: March 2009

Conventional biomarker discovery focuses mostly on the identification of single markers and thus often has limited success in disease diagnosis and prognosis. This study proposes a method to identify an optimized protein biomarker panel based on MS studies for predicting the risk of major adverse cardiac events (MACE) in patients. Since the simplicity and concision requirement for the development of immunoassays can only tolerate the complexity of the prediction model with a very few selected discriminative biomarkers, established optimization methods, such as conventional genetic algorithm (GA), thus fails in the high‐dimensional space. In this paper, we present a novel variant of GA that embeds the recursive local floating enhancement technique to discover a panel of protein biomarkers with far better prognostic value for prediction of MACE than existing methods, including the one approved recently by FDA (Food and Drug Administration). The new pragmatic method applies the constraints of MACE relevance and biomarker redundancy to shrink the local searching space in order to avoid heavy computation penalty resulted from the local floating optimization. The proposed method is compared with standard GA and other variable selection approaches based on the MACE prediction experiments. Two powerful classification techniques, partial least squares logistic regression (PLS‐LR) and support vector machine classifier (SVMC), are deployed as the MACE predictors owing to their ability in dealing with small scale and binary response data. New preprocessing algorithms, such as low‐level signal processing, duplicated spectra elimination, and outliner patient's samples removal, are also included in the proposed method. The experimental results show that an optimized panel of seven selected biomarkers can provide more than 77.1% MACE prediction accuracy using SVMC. The experimental results empirically demonstrate that the new GA algorithm with local floating enhancement (GA‐LFE) can achieve the better MACE prediction performance comparing with the existing techniques. The method has been applied to SELDI/MALDI MS datasets to discover an optimized panel of protein biomarkers to distinguish disease from control.
Multi‐string theories, massive gravity and the AdS/CFT correspondence
Authors: Niarchos V.
Published: March 2009

Infrared modifications of gravity have been proposed over the years as potentially useful phenomenological models. Massive (multi)‐gravity is an interesting class of such theories. The true nature and the ultimate consistency of many of these models remains, however, unclear as one is frequently faced with important problems, e.g. classical instabilities and strong coupling problems which are hard to resolve without a known UV completion of the theory. In this note, we review a recent attempt to study some of these well known problems with the use of the AdS/CFT correspondence. In this context, products of large‐N conformal field theories coupled by multi‐trace interactions in diverse dimensions are used to define quantum multi‐gravity (multi‐string/M theory) on a union of (asymptotically) AdS spaces. One‐loop effects generate a small O(1/N) mass for the gravitons and provide non‐trivial examples of massive multi‐graviton theories.
Could the photon dispersion relation be non‐linear?
Authors: Bietenholz W.
Published: March 2009

The free photon dispersion relation is a reference quantity for high precision tests of Lorentz Invariance. We first outline theoretical approaches to a conceivable Lorentz Invariance Violation (LIV). Next we address phenomenological tests based on the propagation of cosmic rays, in particular in Gamma Ray Bursts (GRBs). As a specific concept, which could imply LIV, we then focus on field theory in a non‐commutative (NC) space, and we present non‐perturbative results for the dispersion relation of the NC photon.
Mass spectrometry fingerprinting of media used for in vitro production of bovine embryos
Authors: Ferreira Christina Ramires , Souza Gustavo Henrique Martins Ferreira , Riccio Maria Francesca , Catharino Rodrigo Ramos , Pontes José Henrique Fortes , Basso Andréa Cristina , Júnior José Carlos Ereno , Perecin Felipe , Eberlin Marcos Nogueira
Published: March 2009

Using the bovine species as a biological model, direct infusion chip‐based nano‐electrospray ionization mass spectrometry (nano‐ESI‐MS) fingerprinting in the positive ion mode is used to obtain fast chemical profiles of media used for in vitro production of bovine embryos. Nano‐ESI‐MS fingerprinting is useful for characterization and routine quality control requiring no sample pre‐separation, being able to differentiate four different media (IVM, IVF, SOF and HSOF) via principal component analysis (PCA). For media stored at +4°C for up to 45 days, no significant (p > 0.05) variation was observed in cleavage and blastocyst rate development, as well as in the nano‐ESI‐MS chemical profiles. For media exposed to a heat shock (60°C for 3 h), no significant decrease (p > 0.05) in embryo development rates was observed, but nano‐ESI‐MS profiles were quite distant from fresh control media in the PCA. For frozen media (−70°C for 2 months), again no significant variation (p > 0.05) in embryo development was noticed, but nano‐ESI‐MS profiles from all media were significantly affected. These results indicate that nano‐ESI(+)‐MS fingerprinting was able to characterize different media based on their specific chemical profile. The technique seems therefore applicable as a routine quality control assay, detecting, for example, compositional changes after temperature variations that may affect post‐transfer embryo viability. Copyright © 2009 John Wiley & Sons, Ltd.
PREDICTOR–CORRECTOR SMOOTHING NEWTON METHOD FOR SOLVING SEMIDEFINITE PROGRAMMING
Authors: WU CAIYING , CHEN GUOQING
Published: March 2009

There has been much interest recently in smoothing methods for solving semidefinite programming (SDP). In this paper, based on the equivalent transformation for the optimality conditions of SDP, we present a predictor–corrector smoothing Newton algorithm for SDP. Issues such as the existence of Newton directions, boundedness of iterates, global convergence, and local superlinear convergence of our algorithm are studied under suitable assumptions.
Association between folate intake from different food sources in Norway and homocysteine status in a dietary intervention among young male adults
Authors: Stea Tonje Holte , Uglem Solveig , Wandel Margareta , Mansoor Mohammad Azam , Frølich Wenche
Published: March 2009

The aim of the present investigation was to study the effect of a dietary intervention which combined nutrition information with increased availability of vegetables, fruits and wholegrain bread. The effect of the intervention was determined by changes in the intake of vegetables, fruits, wholegrain bread and estimated nutrients. Furthermore, the study investigated whether changes in relative contribution from different food sources of folate were related to changes in the concentration of plasma total homocysteine (p-tHcy). The 5-month intervention study included 376 male recruits from the Norwegian National Guard, Vaernes (intervention group) and 105 male recruits from the Norwegian National Guard, Heggelia (control group). The study resulted in an increase in the total consumption of vegetables, fruits, berries and juice (P < 0·001) and of wholegrain bread (P < 0·001). The participants in the intervention group showed a higher increase in the intake of dietary fibre (P < 0·001) and folate (P < 0·001) compared with the control group. The relative contribution of folate intake from fruits, vegetables and wholegrain bread was higher in the intervention group compared with the control group (P < 0·001 for all). The increased intake of folate from wholegrain bread was inversely associated with a reduced concentration of p-tHcy (P = 0·017). In summary, the dietary intervention resulted in an increased intake of vegetables, fruits and wholegrain bread and a subsequent increase in folate intake from these food components. Reduction in the concentration of p-tHcy was significantly related to an increased folate intake due to an increased consumption of wholegrain bread.
The moisture equivalent of heavy soils
Authors: Joseph A. F. , Martin F. J.
Published: March 2009

(1) The moisture equivalent of a normal soil diminishes as the weight of soil taken for the determination increases.

(2) Some soils are particularly impermeable to water in thick layers: in these cases the moisture equivalent increases with the weight of soil taken and may become very large owing to waterlogging. A soil may, however, have a very high moisture equivalent without showing waterlogging.

(3) Dilute solutions of flocculating salts such as calcium sulphate, or ammonium nitrate or sulphate, reduce the moisture equivalent, and sodium carbonate increases it.

(4) The effect of sodium carbonate is complicated: with gradually increasing concentration, the moisture equivalent first diminishes and then increases to a maximum, after which there is further diminution.

(5) The soil samples which easily showed waterlogging in the Briggs-McLane apparatus had a higher concentration of hydroxyl-ions (pH) than those which did not.

(6) Whilst the colloidal content of a clay seems related to its moisture equivalent, no such connection appears to exist for substances such as kaolin or aluminium hydroxide.
Breeding cold hardy sweet corn in Britain
Authors: Mather K. , Haskell G.
Published: March 2009

1. Sweet corn is adjusted to the conditions of North America. British climatic conditions differ from American in the longer summer day-length and in lower spring soil temperature. Cold hardiness, i.e. the ability of the seed to germinate after lying in cold, wet soil, is therefore an important factor when introducing sweet corn into Britain.

2. Varieties germinate differently according to when they are sown. Furthermore some varieties germinate better than others in March and even April, thus demonstrating the genetic nature of cold hardiness.

3. Selections were first made from plants surviving March sowings and in later years, as hardiness increased, from those surviving February sowings.

4. Selections for hardiness were made in (i) Canada Gold, (ii) Early Golden Market sweet corn, (iii) Golden Standard Maize dent corn and (iv) derivatives of Peruvian crossed sweet corn.

5. All responded rapidly in their increased ability to germinate from February sowings except the Peruvian sweet derivatives which failed to show much improvement.

6. Future breeding work in Britain depends on establishing from our selections cold hardy inbreds able to combine well in giving good F1's for commercial use.
The breeding history of Picton oats and observations on the behaviour of certain oat crosses
Authors: Hunter H. , Carson G. P.
Published: March 2009

A general account of investigations carried out at the Plant Breeding Institute, Cambridge, on winter oats was published by Hunter (1935). In it brief mention is made of the origin of a series of oats designated the ‘ex 109/1 series’. It is the purpose of this article to give a more detailed account of the origin and behaviour of this series, from which the winter variety Picton was selected, and to detail a further number of anomalous features which have arisen in the course of breeding work at Cambridge.
The vitamin content of Romney ewes' milk
Authors: McGillivray W. A.
Published: March 2009

Using microbiological methods, thiamin, riboflavin and niacin have been determined in individual milk samples taken from a number of ewes at intervals during their lactation. Although considerable individual variations were found, the average values of 0.67μg./ml. for thiamin, 5.68μg./ml. for riboflavin and 4.80μg./ml. for niacin in New Zealand ewes' milk are somewhat higher than those reported by overseas workers. No lactational effects are apparent from the results presented.
The carotene content of dried grass
Authors: Waite R. , Sastry K. N. S.
Published: March 2009

1. Losses in carotene from fresh grass have been studied during the operations of wilting and drying and from bales of dried grass and dried grass meal during storage.

2. With good management wilting and drying need cause only 15–20% reduction in the carotene content of the fresh grass. In fine, sunny weather field wilting is likely to cause serious loss, and the period of wilting should not exceed 2–3 hr.

3. Production of dried grass meal by efficiently run commercial driers is unlikely to cause more than 5–10% loss in carotene content, whereas during storage for 6 months 30–40% of the carotene initially present in the dried product may be lost, depending on the temperature.

4. Exposure of the dried grass to sunlight quickly bleaches it, but carotene losses due to photochemical action will be confined to a thin surface layer.
Sperm survival in the genital tract of the mare
Authors: Burkhardt John
Published: March 2009

1. Seven matings in which there were sperm survival times of 66–76 hr. in a mixed group of pony mares resulted in seven pregnancies. Of six matings with an interval of 90–100 hr., five proved pregnant. One mare, mated with an interval of 126–138 hr., also became pregnant.

2. Where pregnancy urine extract is injected to bring about ovulation, the injection-ovulation interval can be accurately forecast at 40–48 hr. If the interval is longer the follicle was not sufficiently advanced to warrant injection, if shorter the follicle would have ovulated naturally in the same time.
The water intake of milking cows grazing Pangola grass (Digitaria decumbens Stent.) under wet- and dry-season conditions in Trinidad
Authors: Wilson P. N. , Barratt M. A. , Butterworth M. H.
Published: March 2009

1. The water intakes of ten Holstein × Zebu milking cows, yielding between one and two gallons of milk a day, were analysed on the basis of (a) freewater drunk, and (b) feed-water consumed with the herbage. Trials took place during a 10-day period in both the wet season, 1959 and the dry season, 1960. During both seasons the cows were rotationally grazed on Pangola grass pastures.

2. The results showed a difference of only 24% in total water intake between seasons. However, the mean intake of free water increased from 18·5 lb. per cow in the wet season to 81·5 lb. per cow per day in the dry season, and the intake of feed water decreased from 94·9 to 59·2 lb. per cow per day, respectively. The between cow coefficients of variation were 9·7 and 8·7%, respectively.

3. Results are presented for the drinking habits of Holstein × Zebu cattle grazing Pangola grass pastures. For 567 observed cow-days in the wet season, the cattle were found to drink water on average 0·8 times per day from troughs present in the pastures. For 332 observed cow-days in the dry season, the cattle increased their drinking habits to a mean figure of 1·4 times each day.
The protein and energy nutrition of the bacon pig:IV. Digestible energy values of cereals in pig diets
Authors: Robinson D. W. , Prescott J. H. D. , Lewis D.
Published: March 2009

For optimal growth and production animals require an adequate supply of each nutrient in the diet. This means that within the total of the ration every constituent is allocated its own appropriate proportion and that all the components fit into an ideal balance one with the other. It is reasonably straightforward to define the principles of allocation for vitamins and minerals where a particular chemical entity serves a reasonably well-defined specific function. The definition of the protein component reflects a requirement for certain essential amino acids and for the materials necessary to synthesize the non-essential ones. There remains, however, a major portion of the diet that is not amenable to such specific definition. This fraction includes various chemical entities—fats, carbohydrates and fibrous materials—which are not in themselves indispensable nutrients. It is now accepted, however, that the nutritive value of these components can for convenience be expressed as a whole in terms of their capacity to release energy upon oxidation.
Seasonal fluctuations in the sexual activity of Awassi, German Mutton Merino, Corriedale, Border-Leicester and Dorset Horn rams:IV. Seasonal changes in the spermatogenic activity of Awassi rams and their relationship to the fructose and citric acid contents of semen
Authors: Amir D. , Volcani R.
Published: March 2009

Exhaustion tests were carried out with two Awassi rams 4 times a year for 2 years. The maximum sperm number was obtained in October and the minimum in January. If we consider that the time needed for one spermatogenic cycle and for the migration of the sperm cells through the epid i dymal canal is over 2 months, we may assume that the spermatogenic activity changes with the length of day and reaches its maximum and minimum values during the longest and shortest days, respectively, whereas its androgenic activity is delayed by 3–4 months after the length of daylight changes.
Evaluation of phosphate fertilizers: II. Residual value of nitrophosphates, Gafsa rock phosphate, basic slag and potassium metaphosphate for potatoes, barley and swedes grown in rotation, with special reference to changes in soil phosphorus status
Authors: Mattingly G. E. G.
Published: March 2009

The residual value of three nitrophosphates, potassium metaphosphate, basic slag and rock phosphate was compared with that of superphosphate in two experiments with potatoes, barley and swedes grown in rotation. The residual value of the fertilizers was also compared with that of (a) six cumulative annual dressings of superphosphate supplying either one-half or the same total amounts of phosphate and (b) single fresh applications of superphosphate applied once in each rotation. Yields and phosphorus uptakes are discussed in relation to the amounts of soil phosphate soluble in 0·5 M-NaHCO3.

In the first rotation residues of rock phosphate produced about 1 ton/acre less potato tubers than residues of other fertilizers and cumulative annual applications of superphosphate produced 0·6–0·9 tons/acre less tubers than all residues except rock phosphate. In the second rotation residues of fertilizers increased tuber yields less than cumulative dressings of superphosphate. Over two rotations mean yields from residues and from cumulative dressings were the same. Mean yields of barley over two rotations were 1–3 cwt/acre greater from residues than from cumulative annual dressings; the residual value of the different phosphates was the same. For swedes residues from the alternative phosphates, including basic slag and rock phosphate, were equivalent to those from superphosphate and gave the same mean yields as six cumulative dressings of superphosphate broadcast at planting.

Average residual values of alternative phosphate fertilizers, calculated from (a) yield response, (b) P uptake, and (c) soil analysis were: superphosphate, 100; nitrophosphates, 100–102; potassium metaphosphate, 95; basic slag, 94; Gafsa rock phosphate, 92. Mean percentage ‘fresh’ superphosphate equivalents of residues from all fertilizers were 17 and 26% after the first rotation and 11 and 15% after the second rotation for potatoes and swedes respectively.

The percentage of the total variance in crop yields accounted for by linear regression on NaHCO3-soluble P ranged from 38 to 70% for potatoes, 9 to 28% for barley grain and 42 to 92% for swedes. Mean yields of the crops increased by 0·24 ± 0·037 tons/acre (potatoes), 0·22 ± 0·08 cwt/acre (barley) and 1·16 ±0·148 tons/acre (swedes) for each ppm NaHCO3-soluble phosphorus in the soil at harvest.
Some observations on the lactation of Blackhead ewes and the growth of lambs: the composition and yield of milk
Authors: Butterworth M. H. , Houghton T. R. , Macartney J. C. , Prior A. J. , Middlemiss C. P. , Edmond D. E.
Published: March 2009

Using Persian Blackhead ewes, milk composition and the effect of diet on content of milk fat and milk yield were investigated. Analysis of the milk of nine ewes for fat, protein, ash and lactose (by difference) throughout a twelve-week lactation gave results which were compared with those in the literature. Average values were 5·9, 5·6, 1·0 and 4·8 % respectively. The milk of nine ewes fed on a high plane of nutrition contained significantly more fat than that of ewes fed on a low plane of nutrition; values were 8·8 and 8·3 % respectively. High plane ewes gave significantly more milk than low plane ewes. Ewes suckling twins gave significantly more milk than those suckling singles. Lambs suckling high plane ewes gained significantly more weight than those suckling low plane ewes both from birth to 3 weeks as well as from birth to 12 weeks. Male lambs gained significantly more weight than females.

Highly significant correlation coefficients were obtained between milk consumed by the lamb and its gain in weight. Conversion efficiencies of milk to gain in weight were calculated and compared with literature values.
Upgrading the indigenous poultry of Uganda II. Fertility, hatchability and chick mortality
Authors: Trail J. C. M.
Published: March 2009

An investigation was carried out into the fertility, hatchability and chick mortality levels of the progeny of indigenous poultry of Uganda crossed with cockerels of four imported breeds, these being Light Sussex, Rhode Island Red, White Leghorn and Black Australorp.

Altogether 11,888 eggs were incubated and 1584 day-old chicks reared in the production of these data.

The percentage fertility of eggs from females of all four cross-breeds both when mated to cross-bred and pure-bred imported cockerels was significantly higher than that of eggs from the pure Rhode Island Red breed. Among the four cross-breeds, the Light Sussex × indigenous birds gave the highest fertility figures.

The percentage hatchability of eggs from females of all four cross-breeds when mated with cross-bred males was significantly higher than that of eggs from the Rhode Island Red breed and when mated with cockerels of imported breeds was higher, but not significantly so, than that of the Rhode Island Red. Among the four cross-breeds, the Black Australorp × indigenous birds produced eggs with the highest hatchability figures.

Chick mortality rates of the four cross-breeds from 0 to 20 weeks ranged from 15·7 to 20·0%, the causes of mortality being listed.
Failure of lactating ewes with low plasma magnesium values to respond to large daily magnesium supplements
Authors: Ritchie N. S. , Hemingway R. G.
Published: March 2009

1. 4 g. of Mg per day given as either magnesium oxide or magnesium nitrate failed to increase plasma magnesium levels of fourteen lactating ewes which had initial values of about 1·0 mg. Mg/100 ml.

2. Increases which were recorded 4 hr. after drenching were not sustained for the full 24 hr. period between drenches.
The mineral element content of spring pasture in relation to the occurrence of grass tetany and hypomagnesaemia in dairy cows
Authors: Butler E. J.
Published: March 2009

1. A survey was carried out on dairy farms in the south of Scotland during the period 1958–59 to obtain information on: (a) the mineral element composition of spring pastures associated with grass tetany or staggers and hypomagnesaemia, and (b) the influence of magnesium supplements on the incidence of these conditions and on serum magnesium levels.

2. Pastures associated with grass tetany had a significantly lower average magnesium and sodium content and a higher potassium content than those which were classed as normal. These differences were magnified in the values of the ratios K/(Ca + Mg) and (K + Ca + P)/(Mg + Na) which were considerably higher in tetany pastures. The incidence of tetany was positively correlated with the value of the former ratio. These results are similar to those obtained in Holland.

3. The analytical results for pastures associated with hypomagnesaemia in clinically normal cows were not significantly different from those for normal pastures and there was no evidence of any association between the composition of the pasture and the incidence or severity of the hypomagnesaemia or the serum magnesium levels.

4. The magnesium and sodium contents of the majority of the pastures examined would be judged as inadequate in the light of available information on the requirement of these elements.

5. There was no evidence of any correlation between the magnesium content of the pasture and that of any of the other elements studied.

6. Cases of grass tetany occurred in 25% of the 108 herds studied, the mean incidence in affected herds being 4·5 ± 0·65%. The overall incidence was 1·1 ± 0·25% and was significantly lower when a magnesium supplement was given as a prophylactic measure.

7. Hypomagnesaemia was detected in clinically normal cows after turning out in 41·2% of the herds, the overall incidence being 8·7 ± 1·0%. On tetany free farms the feeding of calcined magnesite or magnesium-rich mineral mixtures did not appear to reduce the incidence of hypomagnesaemia or the fall in serum magnesium levels which occurred after turning out.

8. These results emphasize the wide individual variation in the susceptibility of different cows to the factors causing hypomagnesaemia and grass tetany and also the differences between the two conditions in their dietary relationships. It is suggested that dietary factors may be responsible for producing the clinical signs of grass tetany in hypo-magnesaemic cows.
Results of an experiment at Rothamsted testing farmyard manure and N, P and K fertilizers on five arable crops I. Yields
Authors: Widdowson F. V. , Penny A. , Cooke G. W.
Published: March 2009

1. A ‘reference plot’ rotation experiment was begun at Rothamsted in 1956 on a field where grass had grown for many years. The soil contained very little HCl-soluble P and K but much N. The soil had been acid, but was limed to pH 6·5 immediately before the experiment started; this pH has been maintained. Very small individual plots (0·00128 acre) were used and nearly all work was done by hand. The results showed that such small plots can be used to do complicated rotation experiments satisfactorily provided that all work is done carefully and movement of soil over plot boundaries is prevented.

2. Responses to combinations of N, P and K fertilizers and farmyard manure (FYM) were measured on wheat, kale, barley, grass-clover ley, and potatoes grown in rotation. Two rates of N were tested. A strip of permanent grass had the same treatments as the arable crops.

3. Winter wheat yielded most dry matter, but wheat yields were increased least, proportionally, by added nutrients. Potatoes gave the smallest yield without manure and responded most to nutrients, yields being increased almost sixfold by NPK fertilizer plus FYM. Kale, barley and grass-clover ley were intermediate in their unmanured yields and in their responses.

4. All crops except the grass-clover ley responded to N; kale responded most and wheat least. Potatoes kale and barley responded roughly equally to P and needed this nutrient more than did wheat and the ley. Potatoes responded most to K, yields of wheat and clover ley were also small without K, but barley and kale needed K less. Interactions between nutrients were large with most crops, particularly with N on kale and K on potatoes, wheat and clover.

5. FYM greatly increased yields of all crops but responses were less when fertilizers were also given. Potatoes responded most to FYM whether or not fertilizers were also used. FYM also caused large increases in yields of grass-clover ley, kale, and permanent grass.
Viability of axillary buds of white clover (Trifolium repens) in grazed pasture
Authors: Newton P. C. D. , Hay M. J. M. , Thomas V. J. , Dick H. B.
Published: March 2009

Stolon nodes of white clover were sampled monthly for 18 months from continuously grazed (set stocked) and rotationally grazed pastures in New Zealand. Both pastures were stocked at 22·5 ewes plus lambs/ha. Axillary buds were classified into viability categories using an incubation technique. On average, 54% of nodes had non-viable or dormant buds, 25% had axillary buds that were viable but non-active and 0·1% bore reproductive buds. Although 21% of buds emerged, only 8·5% of nodes bore live branches. Bud activity was strongly inhibited during the spring period of both years and this inhibition could not be removed by incubation.

The greatest bud viability occurred at node 4 (from the apex) although 30–40% of the buds at this position were non-viable. This pattern of variation changed somewhat with season. Some viable buds were present at nodes more than 20 from the apex but these were of low vigour. Secondary stolons had different patterns of bud activity from those of primary stolons until they comprised more than 16 nodes.
Experiments on the effects of phosphate applied to a Buganda soil: III. A chemical study of the soil phosphate, the fate of fertilizer phosphate and the relationship with iron and aluminium
Authors: Le Mare P. H.
Published: March 2009

Solubility products (pKsp) for iron and aluminium hydroxides and phosphates have been determined in a Buganda acid clay loam. Significantly greater values, i.e. lower solubility products occurred when determined at a soil:solution ratio of 0·4 than at 0–8. In the most acid soils, pH 4·8–5·0, values of pKsp) were consistent with the possibility that iron and aluminium concentrations were controlled by goethite and gibbsite. Above pH 5 the data indicated that these minerals were not effective. The maximum pKsp) value for iron phosphate was too small to be consistent with that for strengite, indicating that this mineral did not affect phosphate concentration in the soil; the maximum value for aluminium phosphate was consistent with that for variscite but the occurrence of this mineral cannot be deduced from the data. Triple superphosphate applied at 8 cwt per acre or less was converted within 2 years to a very insoluble form, having a solubility similar to that of variscite; with 16 cwt per acre the phosphate concentration was much greater than with the smaller dressings after this period and the soils appeared supersaturated with variscite.
Chemical composition and cold hardiness of the pith in marrow-stem kale
Authors: Thompson K. F. , Taylor J. P.
Published: March 2009

Percentages of soluble dry matter (S.D.M.), determined in expressed sap from the pith of kale stems by using a hand refractometer, were higher near the vascular bundles than in the centre of the pith and also varied from the top to the base of any one stem. Sampling errors were minimized by taking vertical borings midway between the vascular bundles and the pith centre and by taking two bores per stem (base and top). Inbred lines varied for mean S.D.M. Relative S.D.M. values for two inbred lines were maintained through wet and dry periods in the autumn, and values for fifty-eight inbred lines were significantly correlated in the successive years, one with a dry autumn and the other with a wet.

S.D.M. values were positively and significantly correlated with dry-matter percentage (D.M.) of the pith and with total water soluble carbohydrates (W.S.C). Close correlations were also found between S.D.M. and resistance to cold damage, both in the field and in freezing cabinets for inbred lines of marrow-stem kale and for other cultivars of Brassica oleracea. Although there are some exceptions to these correlations, the rapid method for determining S.D.M. should be very useful in screening breeding material for cold resistance. The combination of high percentage digestibility of the dry matter of stems and improved winter-hardiness can be achieved by selecting in addition for low fibre content using penetrometer tests.
The use of biochemical parameters in controlling nutritional state in pregnant ewes, and the effect of undernourishment during pregnancy on lamb birth-weight
Authors: Russel A. J. F. , Doney J. M. , Reid R. L.
Published: March 2009

1. Fifty-one Scottish Blackface ewes were divided into three groups and individually fed throughout the latter half of pregnancy: (I) in excess of nutrient requirements, (II) to produce a uniformly moderate degree of undernourishment during the last 6 weeks of pregnancy, and (III) to produce a uniformly severe degree of undernourishment during the last 6 weeks of pregnancy,

2. The prescribed levels of undernourishment were maintained by weekly adjustments of feed intake based on plasma FFA levels (group II) and plasma ketone levels (group III). The use of the technique is discussed.

3. Undernourishment during the latter half of pregnancy reduced birth weights of single and twin lambs after adjustment for weight of the dams to the same extent. In the moderately undernourished ewes the reduction was approximately 10%, and, in the severely undernourished ewes, approximately 25%.
Some effects of infection with yellowing viruses and of fungicide applications on bolting in sugar beet
Authors: Russell G. E.
Published: March 2009

Sugar-beet plants require an appropriate sequence of environmental conditions to change from the vegetative to the reproductive phase during the first year of growth. When plants bolt, the stem lengthens and bears flowers and the stem and root become lignified. Bolting is normally induced by a period of low temperature followed by higher temperatures and long-day conditions. The minimum time necessary, under these conditions, for initiation of bolting varies greatly with individual plants, susceptibility to bolting being genetically controlled. Intensive selection for resistance to bolting has resulted in the production of varieties which are highly resistant to bolting (e.g. Bell & Bauer, 1942; Campbell, 1953; Campbell & Russell, 1964). Elongation of the stem can be induced, without normal vernalization, by spraying beet plants with the naturally occurring growth substance gibberellic acid (Gaskill, 1957; Campbell, 1958). It has also been reported that infection with virus yellows sometimes affects the incidence of bolting (Desprez, 1959), although it has not been recorded which of the two common yellowing viruses in Europe is responsible.
The use of faecal nitrogen as an index for estimating the consumption of herbage by grazing animals
Authors: Arnold G. W. , Dudzinski M. L.
Published: March 2009

Data from thirty-five digestibility trials with sheep in metabolism cages were used to investigate statistically the relationships between organic matter intake (I), faecal organic matter output (F), and the nitrogen concentration in faecal organic matter (N).

The data fell easily into groups due to botanical or seasonal differences in the feed. These groups of data were homogeneous and provided highly significant linear equations of the forms I = bF + cFN and I = a + cFN. When compared these groups of data sometimes showed differences in slope, position or both. A quadratic expression

I = bF + cFN + dFN2

was found to accommodate a majority of the data but to be less precise than I = a + cFN.

A further expression incorporating N as an independent variable was also examined,

I = a + cFN2 + eN.

This expression, although far from being universally adequate, proved to be generally better than existing formulae. When applied to the data of Greenhalgh et. al. (1960), it substantially reduced heterogeneity between data for spring and data for summer pastures.

Causes of variation in the relationship between organic-matter intake and nitrogen in faeces, and some of the hazards of extrapolation from empirical regression relations, are discussed.
The decline of a pea root eelworm (Heterodera göttingiana Liebscher) population in the absence of host plants
Authors: Moriarty F.
Published: March 2009

1. The decline of a pea root eelworm (Heterodera göttingiana Liebscher) population, of which most eggs were formed in 1955, was measured annually from 1955 to 1958 in twenty-two microplots containing loamy sand, and measurements were continued in one of these microplots from 1960 to 1962.

2. Sampling errors increased when egg populations were more than 4 years old.

3. Two crop rotations (fallow, and maize, fallow, carrots) had no effect on decline rate from 1955 to 1958, nor did initial eelworm density.

4. After 3 years the egg population was still 48% of that in 1955. Subsequently the population declined on average by more than 50% per annum. It is suggested that host crops should not be grown more than once every five years.

5. Cysts declined more slowly, with a mean annual rate of 26%.

6. A sharp decline in eggs during the first year followed by at least one year's relative quiescence may be general in Heterodera species; with H. göttingiana unexpected crop failures may be associated in part with the prolongation of this relative quiescence for more than 1 year.
Genetic aspects of appetite and feed choice in animals
Authors: Owen J. B.
Published: March 2009

Body composition in wild animals is regulated within a band that encompasses variations due to seasonal food supply and physiological state (e.g. that of the reproducing, lactating female and the growing juvenile). This body composition is characteristic of the genotype and is notable for the avoidance of obesity (Pitts & Bullard 1968). Urgent behavioural responses are also invoked to minimize weight loss. Figure 1 illustrates this homeostasis diagrammatically for the non-lactating, mature animal.

In this integrated complex, both food intake (quantity) and diet choice (quality) play a major role in achieving the required balance between food-energy intake and ‘net output’ of energy in its various forms such as activity, growth, lactation and change in body reserves. The development of such a system, through evolution, to achieve optimum reproductive fitness in a given environment, is consistent with the theory of optimal foraging which is characteristic of many animals in the wild. Newman (1991) has used such an approach in modelling diet selection by sheep.

Domesticated animals have inherited the complex genome of their progenitors, albeit modified in certain respects through natural and artificial selection, in their new circumstances. Many aspects of the physiology and behaviour of the domesticated animal still relate to the environment in which they evolved. For example Jensen & Redbo (1987) have demonstrated the complex nesting behaviour retained by the modern domestic pig, under free ranging conditions similar to those of its wild progenitor.

Two major non-genetic factors have emerged as major influences on the appetite of domesticated animals and man in modern times.
Effect of varying seed rates and transplanting clonal tillers on the performance of rice under intermediate deepwater conditions (0–80 cm)
Authors: Sharma A. R.
Published: March 2009

Under intermediate deepwater conditions (0–80 cm) at Cuttack, India, direct sowing of the semi-tall rice variety Utkalprabha with 200–800 seeds/m2 produced similar yields in 1989 when heavy rainfall (105 mm) after sowing resulted in more than 50% germination, followed by the gradual accumulation of water in the field. However, in 1990, which was characterized by drought in the initial stages, leading to poor germination (35–40%), followed by a sudden accumulation of water, the crops sown at 200 seeds/m2 produced a significantly lower grain yield than those sown at higher seed rates. Higher seed rates increased plant height, tillers/m2 and panicles/m2 but the associated decrease in panicle weight resulted in similar grain yield production. There was no decrease in the yield of crops sown at all seed rates in 1989 and at > 400 seeds/m2 in 1990 when clonal tillers were removed after 60 days to transplant either the equivalent of or double the uprooted plot area. The loss due to decrease in panicles/m2 with the removal of clonal tillers was compensated for by the resulting increase in panicle weight. The crop planted from clonal tillers produced a significantly higher grain yield than that planted from seedlings of equivalent age raised in a nursery seed-bed with or without fertilizer application. Furthermore, the clonal-propagated crop tolerated simulated flash-flooding better at the early vegetative stage, measured by less tiller mortality and relatively higher dry matter production than in the crop raised from nursery seedlings. Therefore, planting with clonal tillers uprooted from a well-established direct-sown crop is recommended under excess water conditions.
The retention of certain minerals in pigs from birth to 90 kg live weight
Authors: Mudd A. J. , Smith W. C. , Armstrong D. G.
Published: March 2009

A method of preparation of the whole bodies of pigs, suitable for the analyses of their mineral contents, has been described. Two litters of pigs were slaughtered at birth and another two at 8 weeks of age and each pig was analysed for whole body content, of Ca, P, Mg, Na, K and Cl. From another litter of pigs a gilt and castrated male were slaughtered at 23, 41, 54 and 90 kg live weight and their bodies analysed for the same elements. The data were used to derive a series of regression equations relating mineral contents to empty body weight for pigs at birth, 8 weeks of age and from 23 kg to 90 kg live weight. The regression coefficients, which provide a measure of the amount of a particular mineral retained in g/kg increase in empty body weight were, for pigs at birth Ca, 7·9; P, 6·3; Mg, 0·3; Na, 1·5; K, 1·9; Cl, 4·8; for pigs at eight weeks of age, Ca, 13·3; P, 7·4; Mg, 0·5; Na, 1·6; K, 2·3; Cl, 1·7; and for pigs from 23–90 kg live weight Mg, 0·4; Na, 1·3; K, 2·0; Cl, 1·1. For the older pigs Ca and P retentions (g/kg increase in empty body weight) ranged from 13·5 (Ca) and 7·6 (P) at 23 kg empty body weight to 4·3 (Ca) and 1·0 (P) at 90 kg empty body weight.
The concentration of minerals in the blood of genetically diverse groups of sheep. III. Correlations among calcium, phosphorus, magnesium, potassium, sodium, chlorine, and copper concentration
Authors: Wiener Gerald , Field A. C.
Published: March 2009

Two sets of correlations among blood mineral concentrations were calculated (1) those attributable to the effects of various factors (breed, age, lambing performance, etc.) and (2) those remaining (residual) when the effects of such factors had been removed as sources of variation in mineral concentration (the equivalent of correlations within subclasses).

Correlations arising from breed differences in mineral concentrations were highest for Ca.P (– 0·81), Ca.Cu (0·83) and P.Cu (–0·95). Correlations consequent on changes with the age of the sheep were most marked for Ca.Mg (0·97, P < 0·01) and Cu.K (–0·92, P < 0·05) and approximately 0·8 (P < 0·1) for Ca.K, P.Mg, P.K and K.C1.

Residual correlations were all below 0–2 (although seven of the twenty-one were statistically significant, P < 0·05) suggesting that within subclasses most of the variation in the concentration of anyjone mineral was independent of that in the other minerals. Simple and partial correlations were very similar in magnitude suggesting that the associations found between pairs of minerals were not attributable to joint co-variance with any of the other five minerals.

As the sheep grew older, changes in the concentrations of Ca, P and Mg were significantly correlated with the increases in live weight. Within subclasses, differences among the sheep in live weight were significantly (P < 0·05) and positively correlated with differences in the concentrations of Ca (r, 0·11), Mg (0·13) and Cu (0·11).