bluuebunny/crossref_metadata_2025 huggingface dataset:
Variants within MECP2, a key transcription regulator, are associated with increased susceptibility to lupus and differential gene expression in patients with systemic lupus erythematosus
Authors: Webb Ryan , Wren Jonathan D. , Jeffries Matlock , Kelly Jennifer A. , Kaufman Kenneth M. , Tang Yuhong , Frank Mark Barton , Merrill Joan , Kimberly Robert P. , Edberg Jeffrey C. , Ramsey‐Goldman Rosalind , Petri Michelle , Reveille John D. , Alarcón Graciela S. , Vilá Luis M. , Alarcón‐Riquelme Marta E. , James Judith A. , Vyse Timothy J. , Moser Kathy L. , Gaffney Patrick M. , Gilkeson Gary S. , Harley John B. , Sawalha Amr H.
Published: March 2009

Objective

Both genetic and epigenetic factors play an important role in the pathogenesis of lupus. The aim of this study was to examine methyl‐CpG–binding protein 2 gene (MECP2) polymorphisms in a large cohort of patients with lupus and control subjects, and to determine the functional consequences of the lupus‐associated MECP2 haplotype.

Methods

We genotyped 18 single‐nucleotide polymorphisms within MECP2, located on chromosome Xq28, in a large cohort of patients with lupus and control subjects of European descent. We studied the functional effects of the lupus‐associated MECP2 haplotype by determining gene expression profiles in B cell lines in female lupus patients with and those without the lupus‐associated MECP2 risk haplotype.

Results

We confirmed, replicated, and extended the genetic association between lupus and genetic markers within MECP2 in a large independent cohort of lupus patients and control subjects of European descent (odds ratio 1.35, P = 6.65 × 10−11). MECP2 is a dichotomous transcription regulator that either activates or represses gene expression. We identified 128 genes that are differentially expressed in lupus patients with the disease‐associated MECP2 haplotype; most (∼81%) were up‐regulated. Genes that were up‐regulated had significantly more CpG islands in their promoter regions compared with genes that were down‐regulated. Gene ontology analysis using the differentially expressed genes revealed significant association with epigenetic regulatory mechanisms, suggesting that these genes are targets for MECP2 regulation in B cells. Furthermore, at least 13 of the 104 up‐regulated genes are regulated by interferon. The disease‐risk MECP2 haplotype was associated with increased expression of the MECP2 transcription coactivator CREB1 and decreased expression of the corepressor histone deacetylase 1.

Conclusion

Polymorphism in the MECP2 locus is associated with lupus and, at least in part, contributes to the interferon signature observed in lupus patients.
Defining incident radiographic hip osteoarthritis for epidemiologic studies in women
Authors: Arden Nigel K. , Lane Nancy E. , Parimi Neeta , Javaid Kassim M. , Lui Li‐Yung , Hochberg Marc C. , Nevitt Michael
Published: March 2009

Objective

To evaluate definitions of radiographic hip osteoarthritis (RHOA) for use in longitudinal epidemiologic studies of disease incidence in women.

Methods

We studied 5,839 women from the Study of Osteoporotic Fractures who had had serial pelvic radiographs obtained (mean of 8.3 years apart) and who were followed up (mean followup 7.1 years from the time of the second radiograph) for evaluation of clinical outcomes. Definitions of RHOA were assessed for construct validity (association with symptoms and signs at the time of the second radiograph) and predictive validity (association with total hip replacement [THR] and signs and symptoms a mean of 7.1 years later). Odds ratios (ORs) and 95% confidence intervals were calculated to assess the strength of association using logistic regression.

Results

The cumulative incidence of RHOA ranged from 2.2% to 11.7%. All definitions displayed significant construct validity; the most consistent was found for composite definitions that required the concurrent presence of 2 or more individual radiographic features and definitions based on stringent criteria for joint space narrowing. All definitions except minimum joint space ≤2.5 mm displayed consistent predictive validity. Composite definitions had the strongest associations with THR (OR 10.5–18.5) and hip pain (OR 2.6–2.9). The hips identified as having OA by each definition varied, with especially small overlap between findings using definitions based on osteophytes and those using definitions based on joint space narrowing alone.

Conclusion

Most definitions of incident RHOA display good construct and predictive validity. Composite definitions have the best overall performance, and definitions requiring the presence of both osteophytes (in particular, femoral osteophytes) and joint space narrowing would be recommended for most epidemiologic and genetic studies.
Quantitative heritability of anti–citrullinated protein antibody–positive and anti–citrullinated protein antibody–negative rheumatoid arthritis
Authors: van der Woude Diane , Houwing‐Duistermaat Jeanine J. , Toes René E. M. , Huizinga Tom W. J. , Thomson Wendy , Worthington Jane , van der Helm‐van Mil Annette H. M. , de Vries René R. P.
Published: March 2009

Objective

The majority of genetic risk factors for rheumatoid arthritis (RA) are associated with anti–citrullinated protein antibody (ACPA)–positive RA, while far fewer genetic risk factors have been identified for ACPA‐negative RA. This study was undertaken to quantify the contribution of genetic risk factors in general, and of the predisposing HLA–DRB1 shared epitope (SE) alleles in particular, to the ACPA‐positive and ACPA‐negative subsets of RA, by computing their heritability and assessing the contribution of the HLA SE alleles.

Methods

One hundred forty‐eight RA twin pairs, in which at least 1 twin of each pair had RA, were tested for ACPAs and typed for HLA–DRB1 genotypes. Heritability was assessed in a logistic regression model including a bivariate, normally distributed random effect, representing the contribution of unobserved genetic factors to RA susceptibility, with the correlation of the random effects fixed according to twin zygosity. The contribution of the HLA SE alleles to genetic variance was assessed using a similar model, except that estimates were based on genotype‐specific population prevalences.

Results

The heritability of RA among the twin pairs was 66% (95% confidence interval [95% CI] 44–75%). For ACPA‐positive RA, the heritability was 68% (95% CI 55–79%), and for ACPA‐negative RA it was 66% (95% CI 21–82%). Presence of the HLA SE alleles explained 18% (95% CI 16–19%) of the genetic variance of ACPA‐positive RA but only 2.4% (95% CI 1.6–10%) of the genetic variance of ACPA‐negative RA.

Conclusion

The heritability of ACPA‐positive RA is comparable with that of ACPA‐negative RA. These data indicate that genetic predisposition plays an important role in the pathogenesis of ACPA‐negative RA, for which most individual genetic risk factors remain to be identified.
Notochordal intervertebral disc cells: Sensitivity to nutrient deprivation
Authors: Guehring Thorsten , Wilde Geoff , Sumner Matthew , Grünhagen Thijs , Karney Graeme B. , Tirlapur Uday K. , Urban Jill P. G.
Published: March 2009

Objective

The nucleus pulposus (NP) of the intervertebral disc develops from the notochord. Humans and other species in which notochordal cells (NCs) disappear to be replaced by chondrocyte‐like mature NP cells (MNPCs) frequently develop disc degeneration, unlike other species that retain NCs. The reasons for NC disappearance are unknown. In humans, the change in cell phenotype (to MNPCs) coincides with changes that decrease nutrient supply to the avascular disc. We undertook this study to test the hypothesis that the consequent nutrient stress could be associated with NC disappearance.

Methods

We measured cell densities and metabolic rates in 3‐dimensional cultures of porcine NCs and bovine MNPCs, and we determined survival rates under conditions of nutrient deprivation. We used scanning electron microscopy to examine end plate porosity of discs with NCs and those with MNPCs. Nutrient–metabolite profiles and cell viability were calculated as a function of cell density and disc size in a consumption/diffusion mathematical model.

Results

NCs were more active metabolically and more susceptible to nutrient deprivation than were MNPCs. Hypoxia increased rates of glycolysis in NCs but not in MNPCs. Higher end plate porosity in discs with NCs suggested greater nutrient supply in keeping with higher nutritional demands. Mathematical simulations and experiments using an analog disc diffusion chamber indicated that a fall in nutrient concentrations resulting from increased diffusion distance during growth and/or a fall in blood supply through end plate changes could instigate NC disappearance.

Conclusion

NCs demand more energy and are less resistant to nutritional stress than MNPCs, which may shed light on the fate of NCs in humans. This provides important information about prospective NC tissue engineering approaches.
HLA type and immune response to Borrelia burgdorferi outer surface protein a in people in whom arthritis developed after Lyme disease vaccination
Authors: Ball Robert , Shadomy Sean V. , Meyer Abbie , Huber Brigitte T. , Leffell Mary S. , Zachary Andrea , Belotto Michael , Hilton Eileen , Bryant‐Genevier Marthe , Schriefer Martin E. , Miller Frederick W. , Braun M. Miles
Published: March 2009

Objective

To investigate whether persons with treatment‐resistant Lyme arthritis–associated HLA alleles might develop arthritis as a result of an autoimmune reaction triggered by Borrelia burgdorferi outer surface protein A (OspA), the Lyme disease vaccine antigen.

Methods

Persons in whom inflammatory arthritis had developed after Lyme disease vaccine (cases) were compared with 3 control groups: 1) inflammatory arthritis but not Lyme disease vaccine (arthritis controls), 2) Lyme disease vaccine but not inflammatory arthritis (vaccine controls), and 3) neither Lyme disease vaccine nor inflammatory arthritis (normal controls). HLA–DRB1 allele typing, Western blotting for Lyme antigen, and T cell reactivity testing were performed.

Results

Twenty‐seven cases were matched with 162 controls (54 in each control group). Odds ratios (ORs) for the presence of 1 or 2 treatment‐resistant Lyme arthritis alleles were 0.8 (95% confidence interval [95% CI] 0.3‐2.1), 1.6 (95% CI 0.5–4.4), and 1.75 (95% CI 0.6–5.3) in cases versus arthritis controls, vaccine controls, and normal controls, respectively. There were no significant differences in the frequency of DRB1 alleles. T cell response to OspA was similar between cases and vaccine controls, as measured using the stimulation index (OR 1.6 [95% CI 0.5–5.1]) or change in uptake of tritiated thymidine (counts per minute) (OR 0.7 [95% CI 0.2–2.3]), but cases were less likely to have IgG antibodies to OspA (OR 0.3 [95% CI 0.1–0.8]). Cases were sampled closer to the time of vaccination (median 3.59 years versus 5.48 years), and fewer cases had received 3 doses of vaccine (37% versus 93%).

Conclusion

Treatment‐resistant Lyme arthritis alleles were not found more commonly in persons who developed arthritis after Lyme disease vaccination, and immune responses to OspA were not significantly more common in arthritis cases. These results suggest that Lyme disease vaccine is not a major factor in the development of arthritis in these cases.
Inflation of Type I error rate in multiple regression when independent variables are measured with error
Authors: Brunner Jerry , Austin Peter C.
Published: March 2009

When independent variables are measured with error, ordinary least squares regression can yield parameter estimates that are biased and inconsistent. This article documents an inflation of Type I error rate that can also occur. In addition to analytic results, a large‐scale Monte Carlo study shows unacceptably high Type I error rates under circumstances that could easily be encountered in practice. A set of smaller‐scale simulations indicate that the problem applies to various types of regression and various types of measurement error. The Canadian Journal of Statistics 37: 33‐46; 2009 © 2009 Statistical Society of Canada
New aspects of Bregman divergence in regression and classification with parametric and nonparametric estimation
Authors: Zhang Chunming , Jiang Yuan , Shang Zuofeng
Published: March 2009

In statistical learning, regression and classification concern different types of the output variables, and the predictive accuracy is quantified by different loss functions. This article explores new aspects of Bregman divergence (BD), a notion which unifies nearly all of the commonly used loss functions in regression and classification. The authors investigate the duality between BD and its generating function. They further establish, under the framework of BD, asymptotic consistency and normality of parametric and nonparametric regression estimators, derive the lower bound of their asymptotic covariance matrices, and demonstrate the role that parametric and nonparametric regression estimation play in the performance of classification procedures and related machine learning techniques. These theoretical results and new numerical evidence show that the choice of loss function affects estimation procedures, whereas has an asymptotically relatively negligible impact on classification performance. Applications of BD to statistical model building and selection with non‐Gaussian responses are also illustrated. The Canadian Journal of Statistics 37: 119‐139; 2009 © 2009 Statistical Society of Canada
Production of phytosterol esters from soybean oil deodorizer distillates
Authors: Torres Carlos F. , Fornari Tiziana , Torrelo Guzmán , Señoráns F. Javier , Reglero Guillermo
Published: March 2009

Enzymatic esterification and supercritical fluid extraction was used to produce phytosterol esters from soybean oil deodorizer distillates. The raw material was first subjected to a two‐step enzymatic reaction; the product obtained mainly comprised fatty acid ethyl esters, tocopherols and phytosterol esters, together with minor amounts of squalene, free fatty acids, free sterols and triacylglycerols. The phytosterol esters were then purified from this mixture using supercritical carbon dioxide. Experimental extractions were carried out in an isothermal countercurrent column (without reflux), with pressures ranging from 200 to 280 bar, temperatures of 45–55 °C and solvent‐to‐feed ratios from 15 to 35 kg/kg. Using these extraction conditions, the fatty acid esters were completely extracted and, thus, the fractionation of tocopherols and phytosterol esters was studied. At 250 bar, 55 °C and a solvent‐to‐feed ratio of 35, the phytosterol esters were concentrated in the raffinate up to 82.4 wt‐% with satisfactory yield (72%).
Effect of Thymus haussknechtii and Origanum acutidens essential oils on the stability of cow milk butter
Authors: Dagdemir Elif , Cakmakci Songul , Gundogdu Engin
Published: March 2009

The aim of this study was to investigate the effects of different essential oils (from Thymus haussknechtii Velen and Origanum acutidens Hand.‐Mazz. Letswaart; endemic species in Turkey) on butter stability. These essential oils were added to butter at two concentrations (0.1 and 0.2 wt‐%). The antioxidant activities of the essential oils were compared with control samples (without antioxidant) and containing butylated hydroxytoluene (BHT). All samples were stored at 4 ± 1 °C for 90 days and their peroxide values (PV), thiobarbituric acid (TBA) values, % titratable acidity and some microbiological properties were analyzed. As a result, the lowest PV and TBA values were determined in the samples containing BHT and 0.2% essential oils; however, TBA and PV were at the highest levels in the control samples during storage. The amount of 0.2% of essential oils exhibited strong antioxidant activity, which was almost equal to that of BHT. T. haussknechtii essential oil showed a stronger antioxidant effect as compared to O. acutidens. None of the essential oils showed remarkable antifungal activity. However, the antimicrobial activity of O. acutidens on coliform bacteria was found to be higher than that of T. haussknechtii. Sensory analysis of the butter showed that the samples containing 0.2% essential oils had lower flavor scores than those with 0.1% essential oils. The present results indicate that these essential oils can be considered as an alternative source of natural antioxidants in the manufacture of butter.
Cytochrome P450 2E1 and head and neck cancer: Interaction with genetic and environmental risk factors
Authors: Ruwali Munindra , Khan Anwar Jamal , Shah Parag P. , Singh Arvind Pratap , Pant Mohan C. , Parmar Devendra
Published: March 2009

The present case‐control study investigates the association of polymorphisms in cytochrome P450 2E1 (CYP2E1), involved in the metabolism of tobacco carcinogens and alcohol, with Head and Neck Squamous Cell Carcinoma (HNSCC). In addition, the interaction of CYP2E1 (CYP2E1*5B and CYP2E1*6) with other genetic factors (null genotype of glutathione‐S‐Transferase M1, GSTM1, X‐Ray Repair Cross Complementing Group I, XRCC1 (Arg194Trp), and environmental risk factors such as alcohol and tobacco in modifying HNSCC risk were investigated. Genotypes were determined by the polymerase chain reaction‐restriction fragment length polymorphism (PCR‐RFLP) assay in a total of 350 male cases of HNSCC and an equal number of healthy male controls. Statistical analysis showed a significant increase in HNSCC risk in cases with variant genotypes of CYP2E1*5B (RsaI) (O.R. 3.44; 95% C.I. 1.45–8.14) and CYP2E1*6 (DraI) (O.R. 1.76; 95% C.I. 1.28–2.41). Haplotype analysis revealed that haplotype T‐A was associated with a greater than 10‐fold increase in risk for HNSCC. Our data also revealed a several fold increase in HNSCC risk in cases carrying a combination of variant genotypes of CYP2E1 with the null genotype of GSTM1 or XRCC1 variant genotypes. Alcohol or tobacco use (both smoking and chewing) were also found to interact with variant genotypes of CYP2E1 in significantly enhancing HNSCC risk. This increase in risk associated with an interaction of CYP2E1 genotypes with GSTM1 or XRCC1 or with tobacco and alcohol use demonstrates the importance of gene–gene and gene–environment interactions in the development of HNSCC. Environ. Mol. Mutagen. 2009. © 2009 Wiley‐Liss, Inc.
Case‐control association testing in the presence of unknown relationships
Authors: Choi Yoonha , Wijsman Ellen M. , Weir Bruce S.
Published: March 2009

Genome‐wide association studies result in inflated false‐positive results when unrecognized cryptic relatedness exists. A number of methods have been proposed for testing association between markers and disease with a correction for known pedigree‐based relationships. However, in most case‐control studies, relationships are generally unknown, yet the design is predicated on the assumption of at least ancestral relatedness among cases. Here, we focus on adjusting cryptic relatedness when the genealogy of the sample is unknown, particularly in the context of samples from isolated populations where cryptic relatedness may be problematic. We estimate cryptic relatedness using maximum‐likelihood methods and use a corrected χ2test with estimated kinship coefficients for testing in the context of unknown cryptic relatedness. Estimated kinship coefficients characterize precisely the relatedness between truly related people, but are biased for unrelated pairs. The proposed test substantially reduces spurious positive results, producing a uniform null distribution ofP‐values. Especially with missing pedigree information, estimated kinship coefficients can still be used to correct non‐independence among individuals. The corrected test was applied to real data sets from genetic isolates and created a distribution ofP‐value that was close to uniform. Thus, the proposed test corrects the non‐uniform distribution ofP‐values obtained with the uncorrected test and illustrates the advantage of the approach on real data.Genet. Epidemiol. 33:668–678, 2009. © 2009 Wiley‐Liss, Inc.
Estrogen modulates sexually dimorphic contextual fear extinction in rats through estrogen receptor β
Authors: Chang Yao‐Ju , Yang Chih‐Hao , Liang Ying‐Ching , Yeh Che‐Ming , Huang Chiung‐Chun , Hsu Kuei‐Sen
Published: March 2009

Females and males are different in brain and behavior. These sex differences occur early during development due to a combination of genetic and hormonal factors and continue throughout the lifespan. Previous studies revealed that male rats exhibited significantly higher levels of contextual fear memory than female rats. However, it remains unknown whether a sex difference exists in the contextual fear extinction. To address this issue, male, normally cycling female, and ovariectomized (OVX) female Sprague‐Dawley rats were subjected to contextual fear conditioning and extinction trials. Here we report that although male rats exhibited higher levels of freezing than cycling female rats after contextual fear conditioning, female rats subjected to conditioning in the proestrus and estrus stage exhibited an enhancement of fear extinction than male rats. An estrogen receptor (ER) β agonist diarylpropionitrile but not an ERα agonist propyl‐pyrazole‐triol administration also enhanced extinction of contextual fear in OVX female rats, suggesting that estrogen‐mediated facilitation of extinction involves the activation of ERβ. Intrahippocampal injection of estradiol or diarylpropionitrile before extinction training in OVX female rats remarkably reduced the levels of freezing response during extinction trials. In addition, the locomotion or anxiety state of female rats does not vary across the ovarian cycle. These results reveal a crucial role for estrogen in mediating sexually dimorphic contextual fear extinction, and that estrogen‐mediated enhancement of fear extinction involves the activation of ERβ. © 2009 Wiley‐Liss, Inc.
Glutamate spillover augments GABA synthesis and release from axodendritic synapses in rat hippocampus
Authors: Stafford Misty M. , Brown Molly N. , Mishra Puneet , Stanwood Gregg D. , Mathews Gregory C.
Published: March 2009

Tight coupling between gamma‐aminobutyric acid (GABA) synthesis and vesicle filling suggests that the presynaptic supply of precursor glutamate could dynamically regulate inhibitory synapses. Although the neuronal glutamate transporter excitatory amino acid transporter 3 (EAAT3) has been proposed to mediate such a metabolic role, highly efficient astrocytic uptake of synaptically released glutamate normally maintains low‐extracellular glutamate levels. We examined whether axodendritic inhibitory synapses instratum radiatumof hippocampal area CA1, which are closely positioned among excitatory glutamatergic synapses, are regulated by synaptic glutamate release via presynaptic uptake. Under conditions of spatially and temporally coordinated release of glutamate and GABA within pyramidal cell dendrites, blocking glial glutamate uptake enhanced quantal release of GABA in a transporter‐dependent manner. These physiological findings correlated with immunohistochemical studies revealing expression of EAAT3 by interneurons and uptake of D‐asparate into putative axodendritic inhibitory terminals only when glial uptake was blocked. These results indicate that spillover of glutamate between adjacent excitatory and inhibitory synapses can occur under conditions when glial uptake incompletely clears synaptically released glutamate. Our anatomical studies also suggest that perisomatic inhibitory synapses, unlike synapses within dendritic layers of hippocampus, are not capable of glutamate uptake and therefore transporter‐mediated dynamic regulation of inhibition is a unique feature of axodendritic synapses that may play a role in maintaining a homeostatic balance of inhibition and excitation. © 2009 Wiley‐Liss, Inc.
Application of the fuzzy‐oil‐drop model to membrane protein simulation
Authors: Zobnina Veronica , Roterman Irena
Published: March 2009

The analysis of structural properties and biological activity of membrane proteins requires long lasting simulation of molecular dynamics. The large number of atoms present in protein molecule, membrane (phospholipids), and water environment makes the simulation of large scale. The implementation of simplified model representing the natural environment for membrane proteins is presented and compared with the vacuum simulation and simulation in the presence of water molecules and membrane phospholipids presented explicite. The comparative structural analysis and computational times for these three models makes the simplified model promising. Proteins 2009. © 2009 Wiley‐Liss, Inc.
Electrochemically initiated tagging of thiols using an electrospray ionization based liquid microjunction surface sampling probe two‐electrode cell
Authors: Van Berkel Gary J. , Kertesz Vilmos
Published: March 2009

This paper reports on the conversion of a liquid microjunction surface sampling probe (LMJ‐SSP) into a two‐electrode electrochemical cell using a conductive sample surface and the probe as the two electrodes with an appropriate battery powered circuit. With this LMJ‐SSP, two‐electrode cell arrangement, tagging of analyte thiol functionalities (in this case peptide cysteine residues) with hydroquinone tags was initiated electrochemically using a hydroquinone‐doped solution when the analyte either was initially in solution or was sampled from a surface. Efficient tagging (∼90%), at flow rates of 5–10 µL/min, could be achieved for up to at least two cysteines on a peptide. The high tagging efficiency observed was explained with a simple kinetic model. In general, the incorporation of a two‐electrode electrochemical cell, or other multiple electrode arrangement, into the LMJ‐SSP is expected to add to the versatility of this approach for surface sampling and ionization coupled with mass spectrometric detection. Published in 2009 by John Wiley & Sons, Ltd.
Sugar Cane Policosanols do not Reduce LDL Oxidation in Hypercholesterolemic Individuals
Authors: Kassis Amira N. , Kubow Stan , Jones Peter J. H.
Published: March 2009

Sugar cane policosanols (SCP) have been shown to exert antioxidant properties in various studies conducted in Cuba. Independent studies have since reported no significant effect of SCP consumption on oxidized LDL levels. The objective of the present study was to confirm the effects of Cuban SCP on LDL oxidation using a high‐precision capture ELISA procedure in hypercholesterolemic individuals. Twenty‐one otherwise healthy hypercholesterolemic men and post‐menopausal women participated in a randomized double blind crossover study where they received 10 mg/day of policosanol or a placebo incorporated in margarine as an evening snack for a period of 28 days. Subjects maintained their usual dietary and exercise habits throughout the duration of the study. Blood was collected on the first as well as the last 2 days of the trial. LDL oxidation was measured from plasma using a solid phase two‐site enzyme immunoassay. A lack of effect of SCP was observed on LDL cholesterol levels, as well as no difference in LDL oxidation between the SCP treatment and placebo at the end of the intervention period. Subject body weights remained stable throughout the study and showed no significant correlation with LDL oxidation levels. Absolute levels of plasma LDL cholesterol were significantly (P < 0.05) correlated with plasma concentrations of oxidized LDL. The findings of the present study suggest that SCP do not significantly affect LDL oxidation. Our results align with results of recent policosanol research questioning the efficacy of these natural extracts as cardio‐protective agents.
SOME CHARACTERIZATIONS OF HARDY SPACES ASSOCIATED WITH TWISTED CONVOLUTION
Authors: HUANG JIZHENG
Published: March 2009

In this paper, we shall give some characterizations of the Hardy space associated with twisted convolution, including Lusin area integral, Littlewood–Paleyg-function and heat maximal function.
ELEMENTARY PROOFS OF VARIOUS FACTS ABOUT 3-CORES
Authors: HIRSCHHORN MICHAEL D. , SELLERS JAMES A.
Published: March 2009

Using elementary means, we derive an explicit formula for a3(n), the number of 3-core partitions of n, in terms of the prime factorization of 3n+1. Based on this result, we are able to prove several infinite families of arithmetic results involving a3(n), one of which specializes to the recent result of Baruah and Berndt which states that, for all n≥0, a3(4n+1)=a3(n).
On the estimation of nitrates in soils by the phenol disulphonic acid method
Authors: Gimingham C. T. , Carter R. H.
Published: March 2009

So many papers on the use of the phenol disulphonic acid method for estimating nitrates in soils have been published in this country and in America in the last few years, that some apology seems needed for adding yet another note to the literature of the subject. The method possesses great advantages as regards rapidity and convenience over the methods involving distillation and yet in the writers' experience, in spite of the numerous studies already made, it has failed to give entirely satisfactory results; in particular when small quantities of nitrate have to be estimated in soils containing much organic matter, the strong sulphuric acid in the reagent chars the organic matter and makes it exceedingly difficult to match exactly the tints from the soil extracts with those given by the standard nitrate solutions.
Studies on follicle population in relation to fleece changes in lambs of the English Leicester and Romney breeds
Authors: Marca Burns
Published: March 2009

The development of the follicle population in lambs of the English Leicester and Romney breeds has been studied in relation to the developing fleece, skin and fibre samples being taken at four ages, namely at 1, 3, 6 and 9 months after birth. The technique used in obtaining skin samples and preparing them for examination, and of obtaining estimates of the follicle population, and the data thus obtained, are presented and discussed in the foregoing pages. Although as a result of technical difficulties and other misfortunes the complete set (1943). The follicle group in the samples taken at 1 month old showed primary follicles on the ental side, large secondary follicles along the ectal margin, and smaller secondaries, or secondary follicle primordia, situated towards the centre of the group. Accessory structures (sweat gland, arrector muscles) usually associated with primary follicles only, may occasionally be found in connexion with follicles situated on the ectal side of the follicle bundle, and apparently corresponding to large secondary follicles. Attention is drawn to the fact that a group of secondary follicles normally develops around the ectal aspect of each primary follicle, whether the latter is solitary or one of a couplet or trio. It is suggested that the ‘primary group’ (one primary and its associated secondaries) is a fundamental unit of the fleece, although generally included within the trio group.
Studies on Soil manganese
Authors: Heintze S. G. , Mann P. J. G.
Published: March 2009

1. The presence and distribution of divalent and trivalent manganese in pyrophosphate extracts of mineral and highly organic soils were studied.
The pantothenic acid content of poultry feeding stuffs
Authors: Bondi A. , Etinger R. , Meyer H.
Published: March 2009

A suitable modification of the microbiological method for assaying pantothenic acid was developed and the pantothenic acid content in various kinds of poultry-feeding stuffs determined by its use. To assure quantitative liberation of the total amount of the pantothenic acid from the samples it is recommended to digest the samples first with Clarase.

Pantothenic acid content was determined in poultry feeds of animal origin, such as fish-meal, meat-scrap, liver-meal and different kinds of milk-powder. It is remarkable that different kinds of fish-meal differ markedly in their pantothenic acid content.
Mortality, weight and body measurements at birth of Dairy Shorthorn calves
Authors: Braude R. , Walker D. M.
Published: March 2009

1. Records of mortality of Dairy Shorthorn heifer calves in the N.I.R.D. herd from 1924 to 1946 were analysed and show a total loss of 16·3%. Losses due to abortions amounted to 5·1%, to stillbirths 6·3%, and post-natal losses in calves up to 6 months of age, 4·8%.

2. The mean adjusted length of gestation period for 230 Dairy Shorthorn cows was 285·6 days.

3. Calves carried longer were heavier at birth, the average increase in weight amounting to 0·91 lb. per day of gestation.

4. The adjusted mean birth weight of the calves was 81·68 lb. Bull calves are carried longer than heifer calves by about 1·68 days and they are heavier at birth by about 3·29 lb.

5. The birth weight of 111 heifer calves born between 1940 and 1947 was 79·9 lb. as compared with the value obtained before the war of 87·0 lb. for 285 heifer calves.

Some factors affecting the weight of the calf at birth were studied; including the effect of artificial mating.
The growth of lambs before and after birth in relation to the level of nutrition
Authors: Wallace L. R.
Published: March 2009

In the investigation described in this third part of the work, we have studied the effect of imposing two extreme levels of diet upon the pregnant ewe during two periods, one of early and one of late, gestation. In order to build up a comprehensive picture of the effect of these treatments we have been concerned, first, with the changes that they have wrought in the tissues and organs of the mother's body; secondly, with the effect upon the growth and development of the genital tract and its major components, and lastly with the way in which the growth of the tissues and organs of the foetus have responded to the different nutritive levels. While the latter has been our primary concern, the former have been studied in some detail so that we may view the effects produced as a whole, and gain an understanding of any competition that may have occurred between maternal and foetal tissues.
The changing of treatments in a long-term trial
Authors: Pearce S. C. , Taylor J.
Published: March 2009

The changing of treatments during the course of an experiment is discussed both from the point of view of designing trials in which changes are anticipated and of modifying trials that have fulfilled their original purpose. Cases are distinguished according to whether the interactions of original and new treatments are or are not important and recommendations are made for each case.

We are indebted to Miss J. M. S. Thom for preparing the diagrams fot publication.
The effects of singling and advancing season on the composition of thousand-headed kale
Authors: Jones D. J. C.
Published: March 2009

1. Five varieties of thousand-headed kale, grown in singled and unsingled plots, were sampled three times during the winter at monthly intervals. The plants were divided into leaf, top half of the stem and bottom half. Dry matter, the proximate constituents and minerals were determined in the samples.

2. The differences in the composition of the leaf and stem of the plant were similar to those found previously and the top half of the stem was intermediate in composition between the leaf and the bottom half of the stem for all the constituents except potassium.

3. The proportions of the various constituents occurring in the three portions of the plant were calculated and considered in terms of the incomplete utilization of the crop by grazing animals.

4. There were significant increases in the percentage of dry matter in all three portions of the plant as the season advanced. The only other significant changes in composition with advancing season were in the leaf in which the levels of crude protein, crude fibre, ash, calcium, phosphorus and sulphate varied.

5. Singling the crop had no significant effects on its composition, but there was a tendency for the stems of the singled crop to be lower in crude fibre and higher in crude protein and several of the minerals.

6. There were very few differences in the composition of the varieties. They were mainly due to the higher mineral levels in one variety.

7. Samples of the two halves of the stem of thousand-headed kale were divided into their main tissues, e.g. rind, xylem and marrow. These were analysed in the same manner as the samples in the main investigation. The results were used in an attempt to explain the effects of singling, advancing season and variety in terms of different ratios of these tissues.
Comparison of three practical rations for growing pigs
Authors: Braude R. , Lyon Marilyn R. , Rowell J. G.
Published: March 2009

A co-ordinated trial has been carried out at twenty-six centres to compare the effects of three practical rations on performance and carcass quality of fattening pigs. The simplest of these was the ‘Shinfield ration’ (SR) and this was compared with the more elaborate National Pig Progeny Testing Station rations, the ‘old’ ration (OPT) as used until January 1963 and the ‘new’ ration (NPT) as used since January 1963.

The OPT ration was significantly worse than the SR and NPT rations in respect of growth rate and food conversion. The simpler and cheaper SR ration did not differ significantly from the NPT ration. Ration differences were not significant for any carcass measurements.
Effects of grazing management on plasma calcium and magnesium concentrations of ewes in early lactation
Authors: Hemingway R. G. , Ritchie N. S. , Brown Nora A. , Peart J. N.
Published: March 2009

The effects of rotational grazing (twice weekly pasture change) and two systems of set-stocking on plasma calcium and magnesium levels of lactating ewes have been studied.
Seasonal fluctuations in the sexual activity of Awassi, German Mutton Merino, Corriedale, Border-Leicester and Dorset Horn rams:III. Seasonal changes in the fructolytic and respiratory rate of spermatozoa
Authors: Amir D. , Genizi A. , Volcani R.
Published: March 2009

The metabolic activity of spermatozoa, obtained from Awassi, German Mutton Merino, Corriedale and Dorset Horn rams, waa measured every 2–4 weeks over a 2-year period.
A study of the voluntary intake of food and water and the lactation performance of cows given diets of varying roughage contentad libitum
Authors: Owen J. B. , Miller E. L. , Bridge P. S.
Published: March 2009

Twelve Friesian heifers were given four dietary treatments from 2 months before first calving to the end of the first lactation. Two of the treatments involved thead libitumfeeding of a complete diet consisting of a basal concentrate meal of rolled barley with supplements, incorporated into a mixture with either hay or barley straw both coarsely ground and included at a level of 25 % of the complete mix. In the other two treatments either the hay or the straw was givenad libitumin the long form and the concentrate mix fedad libitumfrom a separate self-feeder.

Full records were kept of the intake of food and water, the output and quality of the milk and of live weight. Detailed measurements were made of various aspects of rumen function using one cow on each treatment fitted with a cannula. Rumen samples were also obtained from non-fistulated cows by stomach tube.

The intake of long roughage, particularly straw, by the cow, when offered in conjunction with a separate supply of the concentrate mix, was very low and led to serious falls in milk butterfat content. Where the roughage was incorporated into the complete diet normal butterfat levels were maintained. However, apart from the depressed butterfat levels on the two long roughage treatments the health and condition of the cows remained good.

The very low intake of long straw was associated with a smaller volume of liquid in the rumen, a reduced rate of flow of liquid leaving the rumen, a lower proportion of acetic and butyric acids and a greater proportion of propionic acid in the rumen liquor and finally with a higher blood glucose content. The inclusion of milled roughage resulted in values within the normal range for volume of liquid in the rumen, flow rate of liquid from the rumen, V.F.A. proportions in the rumen liquor and blood glucose.

The intake of both food and water over the productive cycle showed a consistent pattern for all cows. Food intake reached its lowest point around calving followed by a sharp rise to a peak in the 4th month after calving and then a gradual but increasing decline. Water intake followed a similar pattern but the fluctuation was greater and the peak consumption occurred in the 3rd month of lactation. Water intake was more closely associated with D.M. intake than with milk output.

The efficiency of utilization of the complete diets containing the milled roughages is discussed in relation to comparable data from cattle fed conventionally.
Shorn and unshorn Awassi sheep IV. Skin temperature and changes in temperature and humidity in the fleece and its surface
Authors: Eyal E.
Published: March 2009

1. A comparison was made between the skin temperature, humidity and temperature within and on the surface of the fleece of unshorn and shorn sheep. This study was conducted during various seasons of the year, at different environmental temperatures, while sheep were maintained in the shade or subjected to direct sunlight.

2. Accompanying the rise of ambient temperature (in the shade) from 10 to 43° C. there was an increase in skin temperature from 34 to 40° C. and from 28 to 40° C. of the unshorn and shorn sheep, respectively.

3. The relationship between the rise in skin temperature and that of ambient temperature was not linear, but showed a stepwise pattern in which the ‘breaks’ occurred at similar environmental temperatures for both groups, although skin temperatures of shorn sheep were lower than the unshorn.

4. The diurnal change in skin temperature of the shorn sheep was similar to that of the ambient temperature. The decrease in skin temperature of unshorn sheep sometimes lagged behind the fall in environmental temperature. The seasonal variations between summer and winter were more significant in shorn than in unshorn sheep.

5. Fleece surface temperatures measured at the same ambient temperatures ranged between 13 and

42° C. and 16·5–39·5° C. in the unshorn and shorn sheep, respectively. In the break points of the rise in skin temperature, there occurred a drop in temperature gradients between the skin and fleece surface. This probably indicates a rise in thermal conductivity of the fleece at these points.

6. The temperature gradient per unit of fleece thickness is inversely related to the depth of fleece and is greater the nearer to the skin.

7. With exposure to the sun, skin temperatures of both groups greatly increased and occasionally reached 47° C. Under these conditions the differences between shorn and unshorn groups were not consistent.

8. Fleece temperatures of unshorn sheep increased greatly upon exposure to the sun. The maximal temperatures were recorded midway between the fleece surface and skin. These temperatures generally reached 55° C. and sometimes even exceeded 60° C.

9. At ambient temperatures of 30–35° C. the vapour pressure close to the skin of unshorn sheep ranged between 35–40 mm. Hg. With shorn sheep, however, the vapour pressure close to the skin was similar to that of the environment. In Yotvata there was a rise in vapour pressure close to the skin when the ambient temperature increased to 40–43° C. This rise in humidity was paralleled by a rise of vapour pressure throughout the wool. It was not linear but rather showed a ‘step-wise’ pattern.

10. The vapour pressure in fleece and near the skin of sheep subjected to direct sunlight increased considerably (up to 80 mm. Hg). This rise showed a wave-like curve with various degrees of persistency. Appearance of fluid on the skin of Awassi sheep was observed on several occasions.
The threonine requirement of the weanling pig
Authors: Evans R. E.
Published: March 2009

The L-threonine requirement of the weanling pig is 0·45% of the air-dry food. This level supports as good growth and economy of food conversion and promotes as good retention of nitrogen as higher amounts.

It is unlikely, when pigs are fed normal rations, that L-threonine will be the limiting essential amino acid.

A comparison in the period 120–180 lb. live weight between diets supplying 0·47 and 0·87% L-lysine, respectively, showed no benefit from feeding the higher amount. It seems uneconomic to feed animal-protein to supply lysine after 1201b. live weight. The requirement can be met at less cost from vegetable sources.

In conclusion, the author desires to express his indebtedness to Messrs V. Thurlbourn and R. D. Willis for taking charge of the experimental animals during the N-balance trial. Also to Mr E. A. Porter for his care of the pigs during the growth trial.
The effect of tilth on the emergence of spring oats
Authors: Thow R. F.
Published: March 2009

1. A survey of commercial crops of spring oats suggested tilth as a major factor affecting emergence.

2. In field experiments conducted on clay and sandy soils, the surface tilth was regarded as a population of aggregates characterized by size which was analysed by means of a five-point quadrat. A tilth index was calculated from the data thus obtained. Under the rough tilths on the clay soil emergence and tilth were directly related, but on the sandy soil there was an optimum degree of cultivation, the plots with the finest tilth had been over-cultivated and gave a low rate of emergence (Fig. 2).

3. A greenhouse pot experiment examined the effect of a cover above the seed of 21 tilths, of varying proportions of 0·03–0·25 in., 0·25–1·25 in., 1·25–2·25 in. diameter aggregates, the soil below the seed being uniform in all treatments. This confirmed that emergence rates were higher under fine surface tilths than under very rough tilths (Fig. 3). An increase in the proportion of 0·03–0·25 in. fraction increased emergence regularly whereas an increase in the proportion of the 1·25–2·25 in. fraction reduced emergence regularly. The presence of 0·25–1·25 in. aggregates reduced emergence compared with that where 0·03–0·25 in. only were present, but the effect of an increase in the proportion was not regular (Fig. 4).

4. A second greenhouse pot experiment compared the effect of 3 tilths above the seed and 2 irrigation treatments. The low emergence rate (58%) caused by a very rough tilth under restricted irrigation was raised to 86% by liberal irrigation.

5. From the evidence of both pot experiments it is postulated that a covering tilth above the seed of 25% or more by weight of fine soil (0·03–0·25 in.) and not more than 40% of coarse aggregates (1·25–2·25 in.) will permit a rate of emergence of at least 80%.

6. As the fine covering tilths in the pot experiment gave high rates of emergence as compared with rougher tilths, it is suggested that the low rate of emergence, on the sandy soil field experiments, was due to a lack of soil moisture induced by over-cultivation.
Residual value of superphosphate and rock phosphate on an acid soil II. Soil analysis and greenhouse experiments
Authors: Mattingly G. E. G.
Published: March 2009

1. Analyses and a greenhouse experiment on soils taken from a field experiment to estimate residual values of phosphates were used to show changes in the amount and distribution of residual phosphate in the soil.

2. Total and NaHCO2-soluble P were large in the top 0–3 in. of soil after applying superphosphate. Total P was large, but NaHCO3-soluble P much less, where rock phosphate had been applied in the field. Ploughing distributed total and NaHCO3-soluble P more uniformly through the 0–6 in. layer of soil.

3. Soil analysis and crop yields in the greenhouse showed that the residual value of equal amounts of P2O5 as rock phosphate and superphosphate, three years after application, were very similar.

4. At the end of the field experiment the sand fraction of the soil (2000–75 μ) contained about 80% of the phosphate that was applied as rock phosphate in this particle-size range.