bluuebunny/crossref_metadata_2025 huggingface dataset:
Engineering monomeric streptavidin and its ligands with infinite affinity in binding but reversibility in interaction
Authors: Wu Sau‐Ching , Ng Kenneth K.‐S. , Wong Sui‐Lam
Published: March 2009

Natural tetrameric streptavidin captures and immobilizes biotinylated molecules with ultra‐tight binding (Kd ∼ 10−13 to 10−14 M). In contrast, engineered monomeric streptavidin offers reversible binding (Kd ∼ 10−7 M). To develop an ideal engineered streptavidin which possesses both the immobilization capability of the natural streptavidin and the reversible interaction reactivity of the monomeric streptavidin, a pair of engineered biomaterials was designed through molecular modeling. This system consists of two recombinant components: an engineered monomeric streptavidin M6, which has a cysteine residue (C118) near the biotin binding site, and a cysteine containing biotinylation tag. Interactions between M6 and the biotinylated peptide tag go through a two‐stage process (capture and immobilization) to generate a covalently linked complex. Biotinylation is essential in the capture stage. Once the biotin moiety in the biotinylated tag is captured by M6, the biotinylated tag can fold back and rotate on the surface of the complex with the biotinylated lysine in the peptide tag as the axis until the formationof a disulfide bond. Consequently, cysteine residue in different positions flanking the biotin residue in the biotinylation tag can successfully form a disulfide bond with M6. Intermolecular disulfide bond formation between M6 and the tag containing protein offers the immobilization capability to M6. In the presence of reducing agent and biotin, bound ligands can be dissociated. This system has the potential to extend the biotin‐streptavidin technology to develop reusable biosensor/protein chips and bioreactors. Proteins 2009. © 2009 Wiley‐Liss, Inc.
Liquid chromatography coupled to quadruple time‐of‐flight tandem mass spectrometry for microcystin analysis in freshwaters: method performances and characterisation of a novel variant of microcystin‐RR
Authors: Ferranti Pasquale , Fabbrocino Serena , Nasi Antonella , Caira Simonetta , Bruno Milena , Serpe Luigi , Gallo Pasquale
Published: March 2009

Cyanobacteria, also called blue‐green algae, occur worldwide within water blooms in eutrophic lakes and drinking water reservoirs, producing several biotoxins (cyanotoxins). Among these, microcystins (MCs) are a group of cyclic heptapeptides showing potent hepatotoxicity and activity as tumour promoters. So far, at least 89 MCs from different cyanobacteria genera have been characterised. Herein, ion trap, matrix‐assisted laser desorption/ionisation time‐of‐flight (MALDI‐ToF) and quadruple time‐of‐flight (Q‐ToF) mass spectrometry (MS)‐based methods were tested and compared for analysing MCs in freshwaters. Method performances in terms of limit of detection, limit of quantification, mean recoveries, repeatability, and specificity were evaluated. In particular, a liquid chromatography/electrospray ionisation (LC/ESI)‐Q‐ToF‐MS/MS method was firstly described to analyse MCs in freshwaters; this technique is highly selective and sensitive, and allowed us to characterise the molecular structure of an unknown compound. Indeed, the full structural characterisation of a novel microcystin variant from a bloom of Planktothrix rubescens in the Lake Averno, near Naples, was attained by the study of the fragmentation pattern. The new cyanotoxin was identified as the 9‐acetyl‐Adda variant of microcystin‐RR. Copyright © 2009 John Wiley & Sons, Ltd.
Fully automated chip‐based negative mode nanoelectrospray mass spectrometry of fructooligosaccharides produced by heterologously expressed levansucrase from Pseudomonassyringae pv. tomato DC3000
Authors: Visnapuu Triinu , Zamfir Alina D. , Mosoarca Cristina , Stanescu Michaela D. , Alamäe Tiina
Published: March 2009

Pseudomonas syringae pathovars possess multiple levansucrases with still unclear specific roles for bacteria. We have cloned and expressed three levansucrase genes, lsc1, lsc2 and lsc3, from P. syringae DC3000 in Escherichia coli. Levansucrases synthesize a high molecular weight fructan polymer, levan, from sucrose and in the case of some levansucrases, fructooligosaccharides (FOS) with potential prebiotic effects are also produced. The ability of purified Lsc3 protein of DC3000 to synthesize FOS was tested using prolonged incubation time and varied concentrations of sugar substrates. Thin‐layer chromatography (TLC) analysis of reaction products disclosed formation of FOS from both sucrose and raffinose, revealing a new catalytic property for P. syringae levansucrases. In order to analyze Lsc3‐produced FOS in underivatized form, we optimized a novel method recently introduced in carbohydrate research, based on fully automated chip‐based nanoelectrospray ionization (nanoESI) high‐capacity ion trap mass spectrometry (HCT‐MS). Uding chip‐based nanoESI MS in negative ion mode, FOS, with degrees of polymerization up to five, were detected in reaction mixtures of Lsc3 with sucrose and raffinose. For confirmation, further structural analysis by tandem mass spectrometry (MS/MS) employing collision‐induced dissociation at low energies was performed. To validate the method, commercial inulin‐derived FOS preparations Orafti®P95 and Orafti®Synergy1, which are currently used as prebiotics, were used as controls. By chip‐based nanoESI HCT‐MS, similar FOS distribution was observed in these reference mixtures. Thereby, the obtained data allowed us to postulate that FOS produced by the Lsc3 protein of P. syringae DC3000 may be prebiotic as well. Copyright © 2009 John Wiley & Sons, Ltd.
Ductus venosus Doppler in screening for trisomies 21, 18 and 13 and Turner syndrome at 11–13 weeks of gestation
Authors: Maiz N. , Valencia C. , Kagan K. O. , Wright D. , Nicolaides K. H.
Published: March 2009

Objectives

To investigate the performance of first‐trimester screening for aneuploidies by including assessment of ductus venosus flow in the combined test of maternal age, fetal nuchal translucency thickness, fetal heart rate, and serum free β‐human chorionic gonadotropin and pregnancy‐associated plasma protein‐A.

Methods

Screening by the combined test was performed in singleton pregnancies, including 19 614 with euploid fetuses, 122 with trisomy 21, 36 with trisomy 18, 20 with trisomy 13 and eight with Turner syndrome. In all cases the a‐wave in the fetal ductus venosus flow was assessed. We examined the performance of two screening strategies: first, assessment of the a‐wave in all patients and, second, first‐stage screening using the combined test in all patients followed by second‐stage assessment of the a‐wave only in those with an intermediate risk of one in 51 to one in 1000 after the first stage

Results

Reversed a‐wave was observed in 3.2% of the euploid fetuses, and in 66.4%, 58.3%, 55.0% and 75.0% of fetuses with trisomies 21, 18 and 13 and Turner syndrome, respectively. Inclusion of ductus venosus flow in all pregnancies would detect 96%, 92%, 100% and 100% of trisomies 21, 18 and 13 and Turner syndrome, respectively, at a false‐positive rate of 3%. The same detection rates were achieved with the two‐stage strategy at a false‐positive rate of 2.6%, in which it was necessary to assess the ductus venosus in only 15% of the total population.

Conclusions

Assessment of ductus venosus flow improves the performance of first‐trimester screening for aneuploidies. Copyright © 2009 ISUOG. Published by John Wiley & Sons, Ltd.
Multilevel Community‐Based Culturally Situated Interventions and Community Impact: An Ecological Perspective
Authors: Trickett Edison J.
Published: March 2009

The purpose of this paper is to apply an ecological perspective to the conduct of multilevel community‐based culturally‐situated interventions. After a discussion of the emerging consensus about the value of approaching such interventions ecologically, the paper outlines a series of questions stimulated by an ecological perspective that can guide further theory development in conducting multilevel interventions. These questions all derive from the importance of assessing the local community ecology where the intervention occurs. The paper concludes with a series of topics which, taken together, provide a roadmap for further conceptual development of multilevel interventions as vehicles for long‐range community impact.
A Social Disorganization Perspective on Bullying‐Related Attitudes and Behaviors: The Influence of School Context
Authors: Bradshaw Catherine P. , Sawyer Anne L. , O'Brennan Lindsey M.
Published: March 2009

Social disorganization theory suggests that certain school‐level indictors of disorder may be important predictors of bullying‐related attitudes and behaviors. Multilevel analyses were conducted on bullying‐related attitudes and experiences among 22,178 students in 95 elementary and middle schools. The intraclass correlation coefficients indicated that 0.6–2% of the variance in victimization, 5–10% of the variance in retaliatory attitudes, 5–6% of the variance in perceptions of safety, and 0.9% of the variance in perpetration of bullying was associated with the clustering of students within schools. Although the specific associations varied somewhat for elementary schools as compared to middle schools, the hierarchical linear modeling analyses generally suggested that school‐level indicators of disorder (e.g., student–teacher ratio, concentration of student poverty, suspension rate, and student mobility) were significant predictors of bullying‐related attitudes and experiences. Student‐level characteristics (i.e., sex, ethnicity, status in school) were also relevant to students' retaliatory attitudes, perceptions of safety, and involvement in bullying. Implications for school‐based research and violence prevention are provided.
Optimal waist cutpoint for screening for dysglycaemia and metabolic risk: evidence from a Maori cohort
Authors: Rush Elaine C. , Crook Nic , Simmons David
Published: March 2009

We sought to identify the sex-specific cut-off in waist circumference which best identifies those with metabolic abnormalities consistent with the metabolic syndrome (MS) among Maori, the indigenous people of New Zealand of Polynesian origin. In 3816 self-identified Maori (2742 women, 1344 men) a 75 g oral glucose tolerance test, fasting lipid, anthropometric and blood pressure measurements were made. MS components were defined by Adult Treatment Panel (ATP) III criteria. Waist cut-off was defined using receiver operating characteristic (ROC) curve analysis to define the presence of at least two of the other MS components ( ≥ 2MS). Prevalence of ≥ 2MS was high (42·1 %). In males and females, waist was as good, or better, a predictor of ≥ 2MS (area under ROC 0·73 women, 0·68 men) as waist:hip ratio (0·66, 0·67), BMI (0·72, 0·68) or percentage body fat (0·70, 0·68). The prediction of dysglycaemia using anthropometric variables followed a similar pattern to ≥ 2MS. Waist circumference to predict ≥ 2MS or dysglycaemia in Maori women and men was 98 cm and 103 cm. Applying this cut-off to the International Diabetes Federation (IDF) criteria would identify 27·8 % (34·0 % males, 25·5 % females) with the MS with an OR for ≥ 2MS (adjusted for sex, smoking and age) of 3·5 (95 % CI 3·1, 4·0). Age >48 years, smoking and being male increased the odds of the MS. These waist cut-offs should be considered in both clinical practice and to optimise the definition of the MS for Maori. The validity of these criteria in other Polynesian groups should be confirmed.
Vitamin D deficiency and insufficiency in pregnant women: a longitudinal study
Authors: Holmes Valerie A. , Barnes Maria S. , Alexander H. Denis , McFaul Peter , Wallace Julie M. W.
Published: March 2009

Maternal vitamin D insufficiency is associated with childhood rickets and longer-term problems including schizophrenia and type 1 diabetes. Whilst maternal vitamin D insufficiency is common in mothers with highly pigmented skin, little is known about vitamin D status of Caucasian pregnant women. The aim was to investigate vitamin D status in healthy Caucasian pregnant women and a group of age-matched non-pregnant controls living at 54–55°N. In a longitudinal study, plasma 25-hydroxyvitamin D (25(OH)D) was assessed in ninety-nine pregnant women at 12, 20 and 35 weeks of gestation, and in thirty-eight non-pregnant women sampled concurrently. Plasma 25(OH)D concentrations were lower in pregnant women compared to non-pregnant women (P < 0·0001). Of the pregnant women, 35, 44 and 16 % were classified as vitamin D deficient (25(OH)D < 25 nmol/l), and 96, 96 and 75 % were classified as vitamin D insufficient (25(OH)D < 50 nmol/l) at 12, 20 and 35 weeks gestation, respectively. Vitamin D status was higher in pregnant women who reported taking multivitamin supplements at 12 (P < 0·0001), 20 (P = 0·001) and 35 (P = 0·001) weeks gestation than in non-supplement users. Vitamin D insufficiency is evident in pregnant women living at 54–55°N. Women reporting use of vitamin D-containing supplements had higher vitamin D status, however, vitamin D insufficiency was still evident even in the face of supplement use. Given the potential consequences of hypovitaminosis D on health outcomes, vitamin D supplementation, perhaps at higher doses than currently available, is needed to improve maternal vitamin D nutriture.
A gluten-free diet score to evaluate dietary compliance in patients with coeliac disease
Authors: Biagi Federico , Andrealli Alida , Bianchi Paola Ilaria , Marchese Alessandra , Klersy Catherine , Corazza Gino Roberto
Published: March 2009

A dietary interview performed by expert personnel is considered to be the most appropriate tool to check whether patients with coeliac disease follow a strict gluten-free diet. However, we currently have no straightforward and non-subjective method for performing such a dietary interview. We therefore developed a fast questionnaire based on four simple questions with a five-level score (0–IV). To verify whether our questionnaire is an efficient tool, we applied it to 168 coeliac patients (126 females and 42 males; mean age 42·4 (sd 12·9) years) on a gluten-free diet (median 82, 25th–75th percentile 50–108, range 15–389 months). The score we obtained was compared with the persistence of both villous atrophy and endomysial antibodies while on a gluten-free diet. A comparison with survival of the patients was also performed. Patients were interviewed over the phone by non-expert personnel. The questionnaire was completed in less than 1 min. The lowest results were significantly more frequent among the patients with a persistence of both villous atrophy and positive endomysial antibodies. Death risk was also significantly correlated with the lowest score results. We conclude that our questionnaire is a reliable and simple method of verifying compliance with a gluten-free diet.
The value of mineralogical examination in determining soil types, with a method of examination and a comparison of certain English and Scottish soils
Authors: Hendrick James , Newlands George
Published: March 2009

Accounts have already been published by this department of investigations made as to the origin, nature and properties of the glacial drift soils of the north-east of Scotland; in particular, the soil as found at the Experimental Farm of Craibstone, near Aberdeen, has been studied by means of mechanical analysis and the determination of the chemical composition of the fractions resulting therefrom (4). The results obtained have brought out some characteristic features of the Craibstone soil, and have indicated that important differences may exist between a glacial drift soil, derived mainly from rocks of granitic nature, and such a soil as that of Rothamsted, arising from the “Clay with flints” formation.
Plasma cortisol levels in pregnant ewes
Authors: Saba N.
Published: March 2009

Pregnancy toxaemia in ewes is a metabolic disorder which may occur during the last month of pregnancy. Typical symptoms are anorexia, hypoglycaemia, hyperketonaemia, blindness, ataxia and recumbency. The condition usually proves fatal. Reid & Hogan (1959) have put forward the suggestion that pregnancy toxaemia is an adrenal steroid diabetes. However, pregnancy toxaemia in ewes is generally associated with starvation or severe undernutrition, and McClymont & Setchell (1955) have suggested that under these conditions the symptoms of pregnancy toxaemia are due to cerebral depression caused by hypoglycaemia. As part of investigations on pregnancy toxaemia, adrenal steroid metabolism in ewes was studied. This paper presents data on plasma cortisol levels during the last month of pregnancy in ewes, and the possible effects of undernutrition and cold on these levels.
Field experiments comparing winter and spring applications of ammonium sulphate, ammonium nitrate, calcium nitrate and urea to grassland
Authors: Devine J. R. , Holmes M. R. J.
Published: March 2009

Fourteen experiments were carried out in various parts of England to compare ammoniumsulphate, ammonium nitrate, calcium nitrate andurea applied to grassland in early winter, latewinter and spring at rates supplying 40 and 80lb./acre of nitrogen. Yield of herbage and of nitrogen were recorded at one cut in spring..
Shorn and unshorn Awassi sheep II. Pulse rate
Authors: Eyal E.
Published: March 2009

1. A comparison was made between the pulse rate of shorn and unshorn sheep maintained in the shade and direct sunlight during the various seasons of the year.

2. The variability of the pulse rate during the day generally agreed with the daily changes in body temperature and presumed level of metabolism. Fluctuations were greater in unshorn sheep.

3. Pulse rate was lower during summer (60–100 for unshorn and 63–100 for shorn sheep) than in winter (90–130 for unshorn and 90–115 for shorn sheep). It tended to increase with a rise in ambient temperature, especially during winter and spring. A lower pulse rate accompanied a rise in environmental temperature, during summer. The slowest pulse rate of 42 per minute was observed during summer in the hot dry area.

4. The pulse rate of both groups increased with a rise in rectal temperature, particularly at low ambient temperatures. At comparable rectal temperatures, a higher average pulse rate was observed in shorn sheep during winter and spring. With elevated summer temperatures, equal pulse rates were noted in both groups of equal rectal temperatures. Since the rectal temperatures of the shorn exceeded that of unshorn sheep, in high environmental temperatures, and in the sun, their pulse rate under these conditions was also higher.

5. The differences in pulse rate between the two groups appeared to reflect the combined effects of metabolic rate, body temperature and the vasomotor activity, all of which vary with season and environmental temperatures.
Comparison of several ways of measuring soil phosphorus availability
Authors: Hagin J. , Hillinger J. , Olmert A.
Published: March 2009

Laboratory indices of P availability were compared for six soils. Phosphorus soluble in sodium bicarbonate, ammonium fluoride and citric acid solutions, and in water was determined. Maximum P adsorption capacity was calculated from data by a batch method obtained from equations using the Langmuir isotherm. Adsorbed P values were derived from the same equations. Measurements of P adsorption obtained by leaching soil samples with a phosphate solution yielded asymptotic curves which also allowed the maximum adsorption capacity to be calculated. Results obtained by the two methods were very similar. Leaching of soil samples by water was the basis for calculating maximum P desorption values; these agreed well with the adsorbed P values obtained from the Langmuir isotherm.

Phosphorus uptake by plants, determined in a greenhouse experiment, was correlated with the various data and parameters obtained in the laboratory; there were no significant correlations with the P values from extraction methods, but there were good correlations with some of the parameters from the equilibration and leaching experiments.
The effects of magnesium compounds and of fertilizers on the mineral composition of herbage and on the incidence of hypomagnesaemia in dairy cows
Authors: McConaghy S. , McAllister J. S. V. , Todd J. R. , Rankin J. E. F. , Kerr J.
Published: March 2009

1. An experiment, lasting 3 years, was carried out to investigate the control of hypomagnesaemia on a medium-heavy loam soil in Northern Ireland, using as criteria herbage analysis and analysis of blood sera of grazing dairy cows.

2. Applications of calcined magnesite and magnesian limestone as soil treatments raised the magnesium contents of herbage slightly but not to levels judged to be safe. Low blood sorum magnesium levels were recorded for cows grazing this herbage although no cases of tetany occurred.

3. Magnesium sulphate, appliedas a spray, temporarily raised the ‘apparent’ magnesium content of the herbage but was easily washed off by rain.

4. Finely powdered calcined magnesite applied as a dust to the herbage immediately before grazing appeared to be a promising method of control under Northern Ireland conditions.
Digestibility trials on forages in Trinidad and their use in the prediction of nutritive value
Authors: Butterworth M. H.
Published: March 2009

Twenty-nine digestibility trials were carried out on various tropical forages and the results obtained were used to investigate possible prediction of nutritive value from chemical composition.

1. The digestibility coefficient of crude protein could be predicted from the level of dietary crude protein. This prediction could be slightly improved by the incorporation of crude fibre in the expression. Results were somewhat higher than those reported from temperate areas.

2. In order to investigate the above phenomena, a value for metabolic faecal protein was calculated. This was found to be similar to values reported from temperate areas. There was no correlation between faecal crude protein and either level of dietary crude fibre or undigested crude fibre.

3. No significant relationships could be obtained to predict total digestible nutrients from either crude fibre or crude protein.

4. There was a low (non-significant) negative correlation between the content of dietary crude fibre and the digestibility coefficient of organic matter; comparison of this value with those in the literature suggested that the effect of crude fibre in tropical areas was different to that reported from temperate areas.

5. Results obtained were compared with standards of intake and nutrient requirements as recommended by the N.R.C. It was concluded that the factor most frequently limiting was digestible crude protein whilst total digestible nutrients were adequate in the greater part of the samples considered.
Water use by irrigated Arabica coffee in Kenya
Authors: Wallis J. A. N.
Published: March 2009

The methods proposed by Pereira for unirrigated coffee have been followed in a study of water use by this crop for the 12 years 1950–62. Soil sampling has shown that the procedure provides a reliable measure of evapotranspiration from unirrigated coffee.

A modification is proposed which has enabled the rate of water use by irrigated coffee to be followed satisfactorily for the 5 years 1957–62. Occasional soil sampling showed that the modified procedure provided an estimate of the soil moisture status sufficiently reliable and accurate for the regulation of irrigation timing and amount.

Irrigation to maintain a favourable soil moisture status has had a marked and beneficial effect on the production of Grade ‘A’ coffee in dry years.

The mean daily rate of evapotranspiration from irrigated coffee is estimated to range from 0·15 in. in hot weather to half this rate during the cool and cloudy season.

The maximum computed annual totals of supplementary irrigation which were required over a 12-year period ranged from 5·5 in. to 31·5 in. with a mean value of 16·0 in. per year.
The control of bacterial blight in rain-grown cotton I. Breeding for resistance in African Upland varieties
Authors: Arnold M. H.
Published: March 2009

Projects carried out in the Lake Province of Tanganyika for breeding Upland cotton resistant to bacterial blight are described.

A programme in which Albar 51 was used as resistant parent was more successful than one in which an attempt was made to transfer the major gene B6m to breeding stocks.

Backcrossing was found to be of limited value as a breeding technique with rain-grown cotton, line breeding in segregating stocks being preferred.

It is demonstrated that resistant types can be synthesized by the systematic exploitation of residual genetic variability in locally adapted populations.

Correlations between stem, boll andleaf resistance are discussed and some deviations attributable to environmental effects described. It is inferred that there is a basic resistance mechanism in all tissues which is under the same genetic control but that results may be confused by genotype-environment interactions and by other factors operating in particular tissues.

The approach to resistance breeding is discussed in relation to the evolution of resistance in African Upland cotton. It is concluded that improvement by straight selection should be given equal emphasis with improvement by hybridization in resistance breeding programmes.
The effect of plant density upon the growth and yield of barley
Authors: Kirby E. J. M.
Published: March 2009

1. Cereal plant density affects yield and growth parameters of fundamental importance. An experiment is described in which growth and development, and yield and yield components of barley grown over a wide range of density were examined.

2. Four varieties of barley—Proctor, Plumage-Archer, Domen, and Moore—were grown at densities approximately equivalent to 35, 70, 140 and 280 lb/acre. Density was found not to affect seedling establishment or plant survival, but there was a variety effect on seedling establishment.

3. Varietal differences were seen in maximum tiller number, and the percentage of tillers surviving to form ears. These differences were most marked between the six-row variety and two-row varieties. The effect of increasing density was to increase the maximum tiller number, but this was followed by different rates of tiller death until early June, after which there was no further compensation for tiller number. Ear emergence and ear number were affected both by variety and density.
The incorporation of the resistance ofAegilops ventricosatoCercosporella herpotrichoidesintoTriticum aestivum
Authors: Kimber G.
Published: March 2009

The introduction of resistance to eyespot (Cercosporella herpotrichoides) fromAegilops ventricosatoTriticum aestivumis described.

In the hybrids, amphiploids and in the amphiploid derivatives investigated, the eyespot resistance was apparently simply inherited. Furthermore, this character was controlled by a chromosome, or chromosomes of the D genome ofAe. ventricosaand thus could be introduced intoT. aestivumby recombination.
Normal variation in alanine aminotransferase activity in sheep and cattle
Authors: Boyd J. W. , Ford E. J. H.
Published: March 2009

The activity of alanine aminotransferase (Al. T) was determined in serum and liver biopsy samples collected from cows over a period of more than a year. There were statistically significant fluctuations in both liver and serum activities during the period of observation. On the whole serum and liver activities appeared to fluctuate independently of one another and of climatic changes. The only possible correlation was between the rate of increase in hours of daylight and the increases in serum and liver activities in the period January to March. The cows were calving at intervals throughout the year, and their liver and serum Al.T activities did not change significantly during the last three months of pregnancy and the first 3 months of lactation.
Tropical grass/legume pastures in Northern Rhodesia
Authors: Smith C. A.
Published: March 2009

Three grass/legume pastures were evaluated under Northern Rhodesian conditions.

A plot trial measured the herbage yields of Stylosanthes gracilis, velvet beans (Stizolobium deeringianum) and giant Rhodes grass (Chloris gayana) grown as pure stands, and in a mixed association with Rhodes grass. The herbage was harvested for 3 years, and the plots were then planted with a maize crop to test any residual effects.

After the establishment year, the D.M. yields, and especially the C.P. yields of the legume and grass/legume treatments, were markedly superior to grass alone. The increased yield of the grass/legume mixtures was due to the net gain contributed by legume herbage. There was no evidence of an underground transference of N from the legume to the associated grass.

Although there was no measurable treatment effect on soil N and C, the maize following the legume and grass/legume treatments had a higher leaf N level, and approximately double the yield, compared with the maize following the grass-alone treatments.

There were no significant differences in cattle weight gains when Rhodes grass alone, Rhodes grass/Stylosanthes, Rhodes grass/velvet beans, and Rhodes grass/pigeon peas (Cajanus cajan) were utilized as hay and foggage in the dry season.

Digestibility trials showed mature Rhodes grass hay to be a submaintenance feed, deficient in dietary protein. The addition of Stylosanthes raised the herbage digestible C.P. fourfold. The Rhodes grass/Stylosanthes hay was a maintenance feed.

The N yield of the grass/legume mixtures, although low by temperate standards, was 2½ times the N yield of grass alone. The potential value of a tropical grass/legume pasture will depend on the efficiency of the legume to fix N.
Effects of drilling date on the growth and yield of sunflower (Helianthus annum) in the UK
Authors: Dixon F. L. , Lutman P. J. W.
Published: March 2009

The growth and yield of five cultivars of sunflower (Frankasol, Cerflor, Sunbred 246, Sokota 2057 and Sigco EX 10), sown from the end of March to the beginning of May, were studied in three experiments at Long Ashton Research Station, UK, during 1986, 1987 and 1988. The time from sowing to emergence and to maturity (as assessed by seed moisture content) was shortened by later drilling, although earlier sown crops were still ready for harvest slightly before the later sown ones. Cultivars differed in speed of development; Frankasol and Cerflor were the slowest to develop and Sigco EX 10 the fastest. Plant heights, head diameters and yields were all affected more by cultivar than by sowing date. The slower maturing cultivars produced the highest yields. Infection levels with Botrytis cinerea seemed to be related to the date of flowering, as early sown and fast developing cultivars became infected earlier. There were few benefits from early sowing and the optimum time appeared to be mid- to late April. Overall, Sunbred 246 was the most successful cultivar in these experiments, combining reasonable yields with moderately early maturity.
Effect of centre of production, maturity and storage treatment of seed tubers on the growth of early potatoes: I. Sprout development in storage
Authors: Goodwin P. B. , Brown A. , Lennard J. H. , Milthorpe F. L.
Published: March 2009

The effect of three centres of production, two times of lifting and two post-harvest treatments of apparently virus-free seed tubers on sprout development at planting was studied over two seasons. Sprout length and degree of development were determined mainly by the light and temperature conditions during storage. Under similar storage conditions tubers from the most southern region, lifted early and allowed to sprout from lifting produced longer sprouts than those from the more northerly regions, lifted late and sprouted from midwinter. At planting all tubers had sprouts longer than 2·5 cm. Desprouted tubers from the more southern regions had the highest number of sprouts at planting and tubers 'greened' immediately on lifting had the least.

An index of sprout development at planting was defined. The conditions and duration of storage had most influence on the degree of development as measured by this index; sprouts were most developed on tubers sprouted over a long period and on those sprouted in a heated glasshouse. The effects of varying centres of production and times of lifting on sprout development at planting were small compared with those readily produced by varying the storage conditions.
Statistical research on the fate of dietary mineral elements in dry and lactating cows IV. Chloride
Authors: Paquay R. , Lomba F. , Lousse A. , Bienfet V.
Published: March 2009

Statistical analyses were carried out on the data obtained under very strict conditions in metabolism stalls with 41 different rations fed to 127 adult non-pregnant dry cows, and with 14 other different rations fed to 35 adult non-pregnant lactating cows that had calved 2–6 months earlier and whose daily milk production ranged from 11 to 20 kg.

The authors have calculated and studied the correlations between faecal and urinary losses of chloride, chloride excretion with the milk, digestible chloride and chloride balance and many other nutritive factors which were analysed for each of the 55 above mentioned experimental diets.

The results show that the digestion and utilization of chloride is not influenced by the amount of ingested chloride at the time of the trial. The digestion is generally very high, negatively correlated with dry matter, energy, and pentosans intakes, and positively with nitrogen and potassium intakes. But the most important factor in the fate of dietary chloride seems to be the necessity for the cow to eliminate most of the time high amounts of potassium in the urines.
Fertility in Scottish Blackface ewes as influenced by nutrition and body condition at mating
Authors: Gunn R. G. , Doney J. M. , Russel A. J. F.
Published: March 2009

Two-hundred-and-seventy-three Scottish Blackface ewes in three ages (5, 4 and 2 years) were differentially group fed over 6 weeks in such a manner that at 6 weeks before mating there were approximately equal numbers in each of six subjectively assessed body condition groups ranging from score 1 (lean) to score 3½ (moderately fat). Over the 6 weeks prior to mating these groups were either well fed, fed at about maintenance, or underfed so that at mating the maj ority of ewes were in either condition 1½ or 3.

A predetermined random sample of mature ewes from each of the six original condition groups was killed 2–3 days post-mating for ovulation counts. Surviving ewes were fed above maintenance post-mating and the number of lambs recorded at birth. Condition at mating had a significant, positive effect on both ovulation and lambing rates but had no effect on infertility measured as the difference between them.

The level of food intake prior to and at mating had no effect on either ovulation or lambing rates of moderately fat ewes (condition 3) but the results can be interpreted as indicating that the level of food intake had a positive effect on both ovulation and lambing rates of lean ewes (condition 1½).
The effect of rate of gain during the growing and finishing periods on the feed efficiency and carcass composition of the pig: I. Rate of gain during the growing period from 18 to 57 kg live weight
Authors: Walker N. , Holme D. W. , Forbes T. J.
Published: March 2009

Two experiments were carried out in which pigs were grown at controlled high, moderate or low growth rates from 18 kg to slaughter at 57 kg live weight. Linear measurements and density determinations were carried out on the carcasses. In the second experiment the right-hand side of each carcass was divided into four joints and each joint was physically dissected into three components, bone, subcutaneous fat plus skin and ‘lean’ meat. The boneless tissue of each joint was analysed for moisture, ether extractable fat and nitrogen.

It was found that an increase in the rate of live-weight gain tended to improve the efficiency with which feed was converted into live weight.

The percentage of fat in the side was significantly increased by more rapid growth rates.

The conformation of the side was altered by treatment, the proportion by weight of the middle region increased with increasing rate of live-weight gain and was accompanied by corresponding reductions in the proportions of the gammon and shoulder regions. These changes were largely due to an effect on the distribution of fat throughout the side, but there were also minor changes in the distributions of bone and fat-free lean.

The high rate of gain was associated with a greater proportion of belly in the side. This was due to an increase in the proportion of lean meat in this region, presumably a functional effect caused by an increased intestinal volume.

There was no treatment effect on the chemical composition of the fat-free boneless meat which was found to differ significantly between joints.
Experiments on the nutrition of the dairy heifer: V. Nutrition in late pregnancy
Authors: Broster W. H. , Tuck Valerie J. , Balch C. C.
Published: March 2009

A randomized block experiment has been carried out with 42 Friesian heifers over a 2-year period to examine the protein and energy requirements in late pregnancy. Rations were based on good quality hay fed to appetite plus various quantities and combinations of oats and decorticated groundnut meal. Minerals were given daily.
Observations on the onset of the breeding season and on the oestrous cycle of the Welsh Mountain ewe
Authors: Hutchinson J. S. M. , O'Connor P. J. , Robertson H. A.
Published: March 2009

1.Within a flock of 55 Welsh Mountain ewes maintained under lowland conditions the first ewe
came into oestrus on the 14th October. The mean cycle length of 44 normal cycles was 16 days 3 hr.

2. The onset of oestrus as assessed by the time of mounting of the ram does not appear to be
evenly distributed throughout the day (24 hr.).
The estimation of the intake of grazing sheep I. Establishment of faecal nitrogen regressions
Authors: Vercoe J. E. , Pearce G. R. , Tribe D. E.
Published: March 2009

1. Regression equations for the ratio of organic matter (O.M.) feed intake to O.M. faecal output on faecal N%, and the N% in the O.M. intake on faecal N% were established over a 52-week period by feeding caged Corriedale wethers on pasture cut from a Wimmera rye-grass (Lolium rigidum Gaud.), subterranean clover (Trifolium subterraneum) sward in a Mediterranean-type environment.

2. The regression equations and their application to grazing sheep together with the relation between O.M. intake and faecal N, are discussed.
The determination of chromic oxide in faeces samples by atomic absorption spectrophotometry
Authors: Williams C. H. , David D. J. , Iismaa O.
Published: March 2009

A rapid and accurate atomic absorption method for the determination of chromium in faeces samples from pasture experiments using chromic oxide ‘markers’ is described. Of the elements present after ashing and digesting the samples in a phosphoric acid—manganese sulphate—potassium bromate solution silicate, aluminium, calcium and magnesium were found to interfere in the determination. The effects of these interferences were overcome by the addition of calcium to the test solution and by the addition of silicate to the standards, which were prepared in ‘blank’ solutions.

The sensitivities of a number of alternate chromium resonance lines relative to that of Cr 3578·7 Å. are given. These lines may be used to increase the concentration range of the analysis.

The results of a comparison of the atomic absorption method with a chemical method are given.
Interpopulational and intervarietal hybridization inLolium perennebreeding: heterosis under non-competitive conditions
Authors: Foster C. A.
Published: March 2009

The current status of herbage grass breeding is considered in relation to the utilization of first-generation hybrid vigour. A breeding scheme is outlined by which it is suggested that interpopulationalF1hybrid varieties could be developed to provide a simple and effective means of exploiting heterotic potential in herbage grass species. A survey of interpopulationalF1heterosis expressed, under two levels of fertility in non-competitive spaced-plants conditions, by the hybrids of a group of six adapted perennial ryegrass varieties, is reported here.

Although theF1hybrid populations studied were not on average superior to the parental varieties there were large variations between specific hybrids. Two hybrids were particularly promising, exhibiting 25% and 31% heterosis over the higheryielding of their parents for total green-matter yield over two harvest years and two fertility levels. The bulk of this heterosis arose under high-fertility conditions, when the mean yield response of the interpopulationalF1hybrid was twice that of the parental varieties.

The effects of inherent relationships between the parental varieties on the observed levels of heterosis are considered, as are the possibilities for the practice of recurrent selection procedures for the enhancement of heterotic expression in some of these hybrids. It is concluded that there is sufficient evidence for the existence of interpopulational heterosis in this species to merit an extension and application of this approach to include a wider range of varieties and. populations, both adapted and introduced.
An investigation into the spacing of monogerm sugar beet seed in the development of the spring mechanization of the crop
Authors: Hanbury L. F. , Maughan G. L.
Published: March 2009

1. Over 3 years monogerm sugar beet seed spacings of up to 5 in apart produced sufficient plants to form an adequate plant population for maximum yields. In the first two seasons the braird from a 5 in seed spacing did not need to be thinned; but in the third it contained over 50,000 seedlings per acre and so had to be reduced by thinning to approximately 30,000 per acre.
Growth, Water use and nutrient uptake from the subsoil by grass swards
Authors: Garwood E. A. , Williams T. B.
Published: March 2009

1. Plant nutrients, N, P and K, were applied to the soil surface or injected at a depth of 18 in. or 30 in. in perennial ryegrass swards, when the upper horizons of the soil profile were dry.

2. When the surface soil was dry and a soil water deficit of 2 in. existed there was no response to surface applied N but injection of N into moist soil at a depth of 18 in. produced a marked increase of growth. At this depth of injection there was a significant positive interaction between N and PK.

3. There was a substantial recovery in the herbage (59–80%) of the nitrogen applied to the subsoil, provided water was available in the soil horizon in which the nitrogen was applied.

4. Failure of a grass sward to regrow after cutting when the water available to the plant has been removed from the uppermost soil horizons is largely due to a deficiency of plant nutrients in the subsoil. The major deficiency is that of nitrogen.
Fertilizer and management responses on permanent downland pasture grazed by cattle
Authors: Kydd D. D.
Published: March 2009

1. The effect of rest during the autumn and winter on the dry-matter production and botanical composition of a cattle-grazed pasture was studied for four consecutive seasons.
The use of fats in pig feeding:I. Pig faecal fat not of immediate dietary origin
Authors: Bayley H. S. , Lewis D.
Published: March 2009

1. A technique has been established for the determination of fat and fatty acid intake and excretion in weaned pigs.
Inheritance of resistance to bacterial blight of cotton:II. Intra-herbaceum crosses
Authors: Innes N. L.
Published: March 2009

In a hybridization programme to study the genetics of resistance to bacterial blight of cotton within Gossypium herbaceum, a major gene, thought to be homologous with Knight's B9, was found in Wagad 8. The strain Chinese Indigenous was also found to possess a major gene for blight resistance but this gene was non-homologous with B9In addition genes there were strains of cotton. to the aforementioned major genes of small effect in both
The hydrolysis by rumen and caecal microbial enzymes of hemicellulose in plant and digesta particles
Authors: Bailey R. W. , Macrae J. C.
Published: March 2009

In sheep fed red clover hay nearly 40% of the feed hemicellulose left the rumen undigested and scarcely any of this hemicellulose was digested in the postruminal digestive tract. The caecal microflora from sheep fed the same diet did, however, yield enzyme extracts which readily hydrolysed isolated hemicellulose or xylan preparations. These caecal and rumen microbial extracts, were capable of hydrolysing the hemicellulose in undigested particulate plant material but were not capable of hydrolysing, to any extent, the hemicellulose in undelignified digesta particles from various parts of the postruminal digestive tract. The hemicellulose in delignified postruminal digesta and the hemicellulose polysaccharides isolated from the digesta were hydrolysed by both rumen and caecal hemicellulases. The results are discussed in the light of observations on the postruminal digestion of hemicellulosic material in roughage- and cerealfed animals.
Lactation studies with Blackface ewes and their lambs
Authors: Peart J. N.
Published: March 2009

Data collected from mid-pregnancy until the 5th week of lactation were used to select three nearly uniform groups each of nine ewes suckling single lambs. After 4 weeks of lactation, experimental treatments were applied to these selected groups as follows: Group I. Both ewes and lambs fed ad lib.throughout. Group II. Ewes fed ad lib. throughout. Lambs offered one-third the quantity of solid food being consumed by group I lambs. Group III. Food intake of ewes restricted to 9·2 g D.o.M./kg, based on their mid-pregnancy live weights. Lambs fed ad lib. throughout. The effects of these treatments were assessed in terms of milk production, food intakes and live-weight changes of ewes, and the solid food intake and growth rates of lambs. Mean total milk production of ewes of groups I and II remained similar until the 8th lactation week, but during the 8–12 week period milk production of the ewes in group II was 6·17 kg greater than that of ewes in group I. The data suggest this difference was due to a reduced intake of milk by the lambs suckling the ewes in group I during the weaning process. From week 4 the milk yield of group III ewes declined rapidly and though these ewes drew on body reserves for milk production, this process could not sustain milk yields. The average daily live-weight gains of lambs of groups I and III were both significantly greater than that of group II, and the gain of group I lambs was significantly greater than that of group III. All groups of ewes made similar live-weight gains during early lactation and after 4 weeks each group had attained a mean value of about 60 kg. Groups I and II continued to gain weight and during week 12 their respective mean weights were 67 and 65 kg. This difference was not statistically significant. The mean live weight of group III ewes declined rapidly after week 4, reaching a minimum value of 41·5 kg. The mean daily intake of dry matter by ewes of all groups reached a maximum value of about 2·9 kg/ewe in lactation week 3 and declined to about 2·6 kg in week 4. Intakes by ewes in groups I and II were almost identical throughout. During the period of restricted feeding the mean daily intake of group III ewes was 0·58 kg dry matter/ewe. During week 5 the mean daily intakes of solid food dry matter by lambs of groups I, II and III were 44, 32 and 158 g respectively. These increased to 1230, 418 and 1537 g respectively during week 12.
Yield and components of yield in diallel crosses between inbred lines of winter beans (Viciafaba)
Authors: Bond D. A.
Published: March 2009

1. Diallel crosses between six inbred lines of winter beans, the selfed parent lines and two commercial varieties were grown in a field trial in two years and records made of yield, number of steins, podded nodes, pods, weight of seed, plant height and width and flowering date. From these data four quotients representing components of yield were obtained.