bluuebunny/crossref_metadata_2025_split huggingface dataset:
The form of mechanical composition curves of soils, clays, and other granular substances
Authors: Robinson G. W. 
Published: March 2009

1. The mechanical analysis of a number of soils, clays, and other granular materials has been carried out by the writer's method and the results have been set out in the form of curves showing the relationship between summation percentages and logarithm of settling velocity.2. The curves obtained are smooth. This suggests that all the necessary information as to the mechanical composition of a material can be obtained by using a relatively small number of experimental points and drawing the appropriate curve. Results obtained on one scale can readily be transferred to another scale by interpolation.3. The most common type of curve is a sigmoid. The steepest portion of the curve represents the fraction present in greatest frequency. This has been termed by the writer the modal fraction. Two sub-types were found. In the case of certain heavy clays, the modal fraction appears to be at the lower end of the curve, whilst in the case of materials mechanically disintegrated the modal fraction is at the upper limit of particle size.4. Composite curves are obtained in certain cases. They may represent mixtures of different materials, or soils in the earlier stages of formation from rock.5. The lower limit of particle size appears to be represented by log in the case of normal soils and clays. In the case of certain finely divided but non-plastic materials, the lower limit appears to be in the region of . It is suggested that a better picture of the properties of soils would be obtained by taking the limit for clay at this poiDt instead of at log .6. The use of the logarithm of settling velocity as a measure of particle size is discussed and it is suggested that the use of negative logarithms might be avoided by using log (v × 107), for which the symbol Lv is proposed.
A quantitative relation between soil and the soil solution brought out by freezing-point determinations
Authors: Keen Bernard A. 
Published: March 2009

An examination has been made of some of the extensive experimental data obtained by Bouyoucos and his associates on the freezing-point depression of soil solution at varying moisture contents, examined in situ.These workers find that the soil solution in quartz sand and extreme types of sandy soil obeys approximately the same law as dilute solutions—the freezing-point depression varying as the concentration, or in the present case, inversely as the moisture content. In other wordswhere K is a constant, and Dn is the freezing-point depression, at a moisture content of Mn. Soils do not obey this law, the freezing-point depression rapidly increasing as the moisture content decreases.
Studies of growth and development in the young pig Part II. A comparison of the performance to 200 lb. of pigs reared along different growth curves to 56 days of age
Authors: Elsley F. W. H. 
Published: March 2009

1. Twenty blocks of four litter-mates were individually fed under standard conditions from 56 days of age to 200 lb. Each block consisted of three early-weaned pigs reared to 50, 40 and 30 lb. live weight, respectively, at 56 days of age and a suckled pig reared to 50 lb. live weight at 56 days of age.2. There was no difference in the growth rate and feed conversion from 56 days of age to 200 lb. of the early-weaned and suckled pigs reared to 50 lb. at 56 days of age.The age at 200 lb. of the 30, 40 and 50 lb. early-weaned pigs were 169·8, 176·8 and 182·7 days and the lb. of meal per lb. live-weight gain 3·3, 3·2 and 3·1 lb., respectively. A reduction in 56-day weight led to an increase in growth rate and feed conversion from 50 to 200 lb. live weight.3. The conformation and composition of the bacon carcasses of the 50 lb. early-weaned pigs were not significantly different from the carcasses of the suckled pigs which also weighed 50 lb. at 56 days of age.An extensive examination of the carcasses of early-weaned pigs showed that an increase in 56-day weight from 30 to 50 lb. live weight signifieantly reduced the weight of muscle present and significantly increased the amount of subcutaneous fat. The conformation of the carcasses was not affected.
Meiotic irregularities in hexaploid oats: II. A cytological survey of the variety Picton
Authors: Howard H. W. 
Published: March 2009

SUMMARY1. Picton, a winter-hardy variety of oats selected from the cross Argentine x Grey Winter, contains plants which have irregular meiotic divisions.2. Two types of irregularities were observed: first, univalents and the products of their division; and secondly, bridges and fragments at both first and second divisions.3. Plants selected for a low frequency of irregularities produced offspring with a low frequency of irregular divisions. On the other hand, plants with regular divisions were also obtained from parents which had a high frequency of irregularities.4. It is pointed out that the genetical effects of bridge chromatid formation and breakage is the production of gametes deficient for chromosome segments. There is some evidence that chlorotic plants are produced when such deficiencies become homozygous.5. It is suggested that the meiotic irregularities produce a certain degree of heterozygosity which may make Picton more adaptable, and at the same time give it a certain degree of hybrid vigour.
The inception of lactation in the cow and goat
Authors: Asdell S. A. 
Published: March 2009

Part I. The changes in amount and composition of the mammary secretions of a heifer in its first pregnancy are recorded.The most striking feature is the abrupt appearance at half-way through pregnancy of a viscous secretion consisting largely of globulin.These results are extended to the primiparous and to the multiparous “dry” goat.Colostrum is shown to be normal milk admixed with the globulin secretion.The significance of the globulin is discussed. Reasons are advanced indicating that it may be an excretion of the cell when it changes from the growth phase to the secretory phase of life.The stimulus to mammary growth is briefly discussed.A partial analysis is given of the secretion from the tubercular udder of a cow. This secretion resembles somewhat the secretions of mid-pregnancy.Part II. Instances are given of cases of premature lactation in the goat, and analyses are recorded of these secretions.These cases are discussed in the light of Part I of this paper, and their bearing on the corpus luteum theory of mammary development is considered. The sexual precocity of the goat is such that the mammary growth may in all cases have been due to luteal influences.A few cases of premature lactation in the cow are also reported.The theory that the foetus produces a hormone inhibiting lactation is shown to be unnecessary.
Control of ovulation in the cow
Authors: Hammond J. , Bhattacharya P. 
Published: March 2009

1. Cows and heifers were injected shortly before slaughter with an extract of horse pituitary or with pregnant mare serum gonadotrophin.2. These substances were administered at different times of the cycle or in pregnancy; various doses were given simultaneously with removal of the corpus luteum.3. A series of animals were given 1500 or 5000 i.u. at intervals from 5 days before to 3 days after expression of the corpus luteum; up to thirty ovulations were so obtained.4. A small number of cows have been treated and left to calve; there have been several twin and triplet births.
Observations On the Characteristics of the Semen in Relation to Fertility in the Bull
Authors: Laing J. A 
Published: March 2009

1. The characters of the semen of twenty-one bulls were compared with their fertility as expressed by the service rate—the number of services required for each conception.2. It was found that, on the basis of the density of the semen, the total number of spermatozoa ejaculated, the motility and change inpH of the semen on incubation at 37° C, the animals could be divided into a higher fertility group with service rates from slightly more than 1·0 to about 3·5, and a lower fertility group with service rates from above 3·5 to ∞. Totally sterile animals could be detected.3. It is suggested that other factors than the quality of the semen can vary fertility so as to give service rates at different levels from 1·0 to about 3·5. Below a certain level of semen quality fertility appears to be impaired no matter what other factors operate.4. No relationship could be detected between the percentage of abnormal spermatozoa ejaculated and the service rate.5. Standards for use in diagnosis of fertility are suggested.
Studies in Tropical Soils I. Identification and Approximate Estimation of Sesquioxide Components by Adsorption of Alizarin
Authors: Hardy F. 
Published: March 2009

1. An alizarin-adsorption method discovered by Schmelev has been successfully applied, with suitable modification, to the identification and approximate estimation of the free sesquioxide components of clays and soils.2. Details of the tested procedure are presented, together with some preliminary results obtained.3. The free alumina component of clays and soils appears to adsorb alizarin only after ignition, whereas the free iron oxide component adsorbs it only in the fresh, unignited state. Hence, by applying the procedure to the fresh, as well as to the ignited material, an approximate estimate of both components may be accomplished in a relatively short time.
The variation in the copper content of the blood of normal sheep
Authors: McDougall E. I. 
Published: March 2009

The blood copper of normal sheep from the Institute flock at Cambridge was studied over the period October-April for three lambing seasons and showed no changes characteristic of pregnancy; in contrast to the behaviour of human beings and possibly sheep of low copper status. What changes there were took place in both pregnant and nonpregnant sheep, did not reflect the transfer of copper to the foetus and appeared to be due to extrinsic factors.Comparison of the blood copper of the lamb with that of its dam for four lambing seasons showed that it was a changing quantity at birth, being lower in the foetus, variable a few hours after birth and higher some days later than in the ewe.The blood copper of suckling lambs was studied from birth in February-March until June, for three seasons. There tended to be high values in the first 1 or 2 weeks of life, which decreased in the course of approximately 10 weeks.
Chick Rearing III. The effect of diet on vitamin A, xanthophyll and carotene metabolism
Authors: Mann T. Barton 
Published: March 2009

Evidence is presented, based on feeding tests, that vitamin A metabolism is adversely affected when meat meal having a vitamin A consuming power in vitro is included in the diet of chicks.Evidence is presented, based on feeding tests, that when fish meal having no vitamin A consuming power in vitro is fed to chicks in a basal ration which produces negligible mortality, the addition of such fish meal to the ration does not appreciably increase mortality.Evidence is presented, based on feeding tests, that when fish meal having a vitamin A consuming power in vitro is fed to chicks in a basal ration which produces negligible mortality, the addition of such fish meal to the ration causes appreciable mortality.
The Sticky Point Water of Soils. Part II
Authors: Marchand B. De C. 
Published: March 2009

Keen and Coutts(8) and Coutts(1) have suggested that the percentage of water in a soil at the sticky point is related to the colloidal content of the soil, as measured by “loss on ignition,” in the following manner:S = mI + c,i.e. by a rectilinear equation, and point out that the figure obtained for c approximates to the theoretical percentage of water held in the interstitial spaces of an ideal soil.
Effect of the level and concentration of liquid milk substitutes fed to early weaned calves
Authors: Burt A. W. A. , Bell E. O. 
Published: March 2009

1. The effects of feeding 6 or 9 oz. of milk substitute in 2 or 3 pints of water per feed were studied in Ayrshire calves weaned at 5 weeks, and of feeding 6 or 9 oz. in 3 pints with calves weaned at 3 weeks.2. In both experiments higher milk substitute intakes significantly improved growth rate without detriment to the consumption of dry food.3. Restriction of water to 2 pints per feed tended to reduce live-weight gain and concentrate consumption and increased free water intake, although not sufficiently to compensate for the restriction.4. In calves weaned at 3 weeks the higher amount of milk substitute produced an effect which was still present at 88 days and this indicated that underfeeding in very early life may be permanently detrimental.5. Regressions of live-weight gain upon concentrate and free water consumption and the progressive increase in live-weight gain and concentrate intake before weaning indicate the importance of this intake in providing energy for the calf before weaning and the beneficial effects of individual vigour.6. The marked effects of the various systems of use of similar foods upon the distribution of liveweight gain during the first month and upon cost are described and discussed.
The mechanism of cellulose digestion in the ruminant organism
Authors: Woodman H. E. 
Published: March 2009

During the carrying out of the series of researches which led to the formulation of the well-known expression for calculating the starch equivalent of a feeding stuff, Kellner(1) was led to investigate the value of crude fibre in the fattening ration of oxen. For this purpose he used material which had resulted from the boiling of rye straw with an alkaline solution under pressure, the object of this treatment being to free the cellulose of the straw from incrusting substances. This fibre-rich preparation was added to a basal ration which was slightly in excess of maintenance requirements. The result produced by the addition to the basal ration of the digestible matter derived from the fibre of the treated straw was found by Kellner to be equal to that produced by the addition of an equal weight of pure starch. The conclusion was therefore warranted that the digestion products of cellulose in the ruminant organism are equal, for purposes of fat formation in the body, to those derived from the digestion of starch. This finding is given practical expression in Kellner1s formula for calculating the starch value of a feeding stuff, an equal value being attached to digestible fibre and digestible carbohydrate.It is clear that any theory which is put forward to explain the breakdown of cellulose in the ruminant tract must be compatible with the experimentally demonstrated fact that the products of such digestion of a given weight of digestible fibre are equal in nutritive value to the products derived from the digestion of the same weight of starch.
A new method for the determination of total phosphoric acid in soils
Authors: Shrikhande J. G. 
Published: March 2009

McLean's shorter method of H2SO4-HNO3 digestion of the soil for total P2O5 failed on some red soils from Ceylon, although Hall's HC1 method gave satisfactory results. The cause of failure of the McLean method was interference by the larger quantities of various bases extracted by H2SO4-HNO3.After first separating the total phosphoric acid as ferric phosphate, McLean's method produced results closely agreeing with those obtained by Hall's method. Total phosphates were separated by first neutralizing the acids in the soil digest and then precipitating the HC1 solutions of the neutralized product by sodium acetate and acetic acid. On boiling, all the phosphoric acid in the soil extract was separated as ferric phosphate. HNO3 solution of this ferric phosphate when precipitated in the usual way gave a clean yellow precipitate of ammonium phospho-molybdate.H2SO4-Se served as a good substitute for H2SO4-HNO3 in soil digestions and the results obtained were substantially the same as by Hall's method or by the modified McLean's method. H2SO4-Se digestion has certain advantages, such as the possibility of determining both nitrogen and phosphoric acid on the same soil digest.When selenium is used as catalyst and the phosphate separated by ammonium acetate and acetic acid, the HNO3 solution of total phosphates produces a white precipitate of a complex ammonium selenito-molybdate along with ammonium phospho-molybdate when precipitated by ammonium molybdate. This defect was eliminated after replacing ammonium acetate by sodium acetate.Attention is drawn to the unexpected behaviour of selenium compounds of phosphoric acid formed during soil digestion towards the reagents used for precipitating total phosphates.
Observations on the Mineral Metabolism of Pullets
Authors: Common R. H. 
Published: March 2009

1. Previous observations on the calcium and phosphorus metabolism of the pullet are confirmed.2. Calcium and phosphorus retention are shown to be related to the amount of sodium chloride in the food.3. The extra phosphorus excretion which accompanies egg laying involves no marked concomitant change of the amount of potassium in the droppings. Small concomitant increases in the sodium in the droppings were observed where the food contained only small amounts of sodium and chloride; potassium retention was observed on the succeeding day in every case but one.
Liming as a factor in the amelioration of deteriorated tropical soils
Authors: Turner P. E. 
Published: March 2009

1. There exist in Trinidad large areas of deteriorated soils which have been under cultivation with a single short-term crop for generations. It has previously been established that these soils differ but little from those which still retain their fertility in their content of organic matter. By comparison with the latter, however, they are markedly acidic and so deficient in exchangeable calcium that a material improvement in their lime status appears to be a necessary preliminary to their amelioration. An examination has therefore been made of the means by which this may most successfully be accomplished.2. Determinations of the contents of exchangeable calcium and the pH values of a series of liming experimental plots indicate that:(a) Contrary to experience in England, finely ground limestone has proved a more efficient soil ameliorant than slaked lime.(b) Single relatively large applications of lime fertilisers have given more immediate beneficial results than small annual dressings.(c) The effect of liming appears to have been almost entirely restricted to the depth to which the soil is worked. This is doubtless due to the impermeability and lack of aeration which characterises heavy deteriorated soils.3. A significant increase in crop yield was obtained only on those plots which were later shown to have been rendered neutral in reaction by liming, and on which the degree of saturation of the top 6 in. of soil has been raised to 80 per cent. This value is comparable with that of the fertile soils of Trinidad.4. The experience of liming methods gained in Trinidad may be applicable to other areas of alluvial soils under cultivation in the tropics.
Blood potassium and haemoǵlobin polymorphism in Indian sheep
Authors: Agar N. S. , Rawat J. S. , Roy A. 
Published: March 2009

SUMMARYBlood potassium and haemoglobin types were investigated in three breeds of sheep in India. Both high and low blood potassium types and all three haemoglobin types—A, B, and AB—were found to be present in two of the breeds examined, namely Bikaneri and Corriedale x Bikaneri. Mandia sheep had both potassium types but only two haemoglobin types—B and AB. Haemoglobin B and high potassium types predominated in all the three breeds; this would clearly point to the comparative suitability of these animals for relatively drier parts of India.
Effect of placement of liquid and solid fertilizer on the growth and yield of potatoes
Authors: Holliday R. , Draycott A. P. 
Published: March 2009

SUMMARYThree field experiments in 1963–5 compared the effects of three methods of fertilizer application, each at four rates, on the growth and yield of main-crop potatoes. Solid fertilizer was broadcast over the furrows and then concentrated round the seed tubers by splitting the ridges during machine planting. Liquid fertilizer was injected immediately after planting either 2 in below and 2 in to the side (shallow placement), or 6 in below and 2 in to the side of the seed tubers (deep placement). Solid and liquid supplied the same quantity of nutrients.In two years deep placement of liquid gave larger yields than the solid fertilizer and in all three years larger yields than shallow placement of liquid. Results from growth analysis of the 1963 crop indicated that deep placement of liquid gave the largest yield after a dry period. Growth analysis on an additional experiment in 1964 showed that when the soil moisture deficit was limited by irrigation to 1-6 in, both the yield and nitrogen uptake from shallowly and from deeply placed liquids were similar. However, without irrigation deep placement gave a larger yield and nitrogen uptake than shallow placement. An artificial 'dry climate' emphasized that the magnitude of the response to deep placement was related to the soil-moisture regime. It is concluded that the deepplaced fertilizer was in a region of the soil which remained moist, whereas the shallower fertilizer was in drier soil where it was less available to the potato roots.
The ammonification and nitrification in soil of urea with and without biuret
Authors: Low A. J. , Piper F. J. 
Published: March 2009

SUMMARYA laboratory investigation was made of the ammonification and nitrification in soil of pure urea with and without pure biuret and pure biuret alone. The soils ranged from acid (pH 5·1) to calcareous (pH 7·9). The work was done at two temperatures 5 and 25°C. The time between adding urea to the soil and the first analysis was from 1 h to 1 week. The soil moisture contents ranged from the wilting percentage to field capacity. In all work involving urea, ammonium sulphate was used as a standard to compare rates of nitrification.Biuret had no detectable effect on the rates of ammonification and nitrification of urea. Biuret by itself nitrified in all the soils at both temperatures being slowest at 5 °C in the acid soil and fastest in the calcareous at 25°C.Neither pH nor temperature appreciably affected the ammonification of urea but both had a marked effect on nitrification. The lower the pH and the lower the temperature the slower the nitrification. Ammonium from urea nitrified faster than ammonium sulphate and on the acid soil only ammonium from the urea nitrified.The moisture content of the soil only affected ammonification of urea slightly but had a marked effect on the nitrification, the drier the soil the slower the nitrification. The same observation applied to ammonium sulphate.