bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chemometrics can be applied to mechanical testing data to characterise stem toughness and stiffness in crop plants
Authors: Kemsley EK , Swinhoe RR , Smith AC , McCann MC , Wang TL 
Published: May 2004

AbstractMechanical tests have been used to assess the engineering properties of pea (Pisum sativum L) stems. Measurements were made on plants of three different genotypes at four different stages of development and at five defined locations along the stem. The force–displacement curves obtained were used to estimate values of the engineering properties of toughness and flexural modulus, from cutting and flexure mechanical tests respectively. Specimens of all genotypes showed an increase in toughness with age and generally also with stem height. However, there were marked differences in flexural modulus between genotypes. One genotype, known to exhibit a ‘stiff straw’ characteristic, showed a consistent increase in modulus with age and stem height, and at and beyond fruiting had substantially the greatest flexural modulus. The remaining genotypes showed decreasing flexural modulus with age. Chemometric methods were used to analyse sets of complete force–displacement curves, following suitable pre‐processing to allow the application of linear algebra methods. Whereas univariate consideration of the engineering quantities allowed trends to be observed, multivariate analysis of force–distance curves was able to model empirically the genotype differences so that individual specimens could be largely correctly classified. Examination of some of the model coefficients suggested that the ability to discriminate between genotypes is related to structural features of the specimens and that cutting tests in particular are sensitive to the anatomy of the specimen. This is the first time that chemometric methods have been applied to such data and suggests the potential of mechanical tests combined with multivariate analysis to form the basis of a screening system for phenotypic properties of new lines and varieties. Copyright © 2004 Society of Chemical Industry
Effect of variety and crude protein content on nutrients and certain antinutrients in field peas (Pisum sativum)
Authors: Wang Ning , Daun James K 
Published: May 2004

AbstractProtein content was used as an indicator of environmental conditions for a study on varietal and environmental variation in proximate composition, minerals, amino acids and certain antinutrients of field peas. Four field pea varieties, each with three levels of protein content, were selected. Crude protein content overall ranged from 20.2 to 26.7%. Analysis of variance showed that both variety and environmental conditions had a significant effect on starch, acid detergent fibre (ADF), neutral detergent fibre (NDF) and fat content, but ash content was only affected by variety. Significant varietal and environmental differences in potassium (K), manganese (Mn) and phosphorus (P) were noted. Calcium (Ca) and copper (Cu) showed significant varietal differences, while iron (Fe), magnesium (Mg) and zinc (Zn) had significant environmental differences. Environmental conditions showed significant effects on alanine, glycine, isoleucine, lysine and threonine content. Variety had a significant effect on sucrose, raffinose and phytic acid content, whereas environmental conditions had an influence on trypsin inhibitor activity (TIA). The major pea components protein and starch were inversely correlated. ADF, NDF, Fe, Mg, Zn and the amino acid arginine were positively correlated with protein content. The amino acids glycine, histidine, isoleucine, lysine and threonine were negatively correlated with protein content. It was found that tryptophan was the most deficient amino acid and the sulphur‐containing amino acids were the second limiting amino acids in peas. Raffinose was positively correlated with sucrose but negatively correlated with verbascose. There were significant correlations between mineral contents and some of the proximate components. Copyright © 2004 Society of Chemical Industry
Effect of applying formic acid, heterolactic bacteria or homolactic and heterolactic bacteria on the fermentation of bi‐crops of peas and wheat
Authors: Adesogan Adegbola T , Salawu Mustapha B 
Published: May 2004

AbstractThis work aimed to compare the effectiveness of bacterial inoculants or a chemical additive for preserving whole‐crop silages made from wheat, two pea varieties (cv Magnus or Setchey) or intercrops of wheat and both pea varieties. The forages were harvested when the wheat and peas were at the late milk and yellow wrinkled stages respectively, and conserved in five replicate mini silos without treatment (control) or after treatment with 2.5 g kg−1 of formic acid (FA) or 1 × 106 cfu g−1 fresh forage of either of two bacterial inoculants (WholeCrop Gold (WCG) or WholeCrop Legume (WCL), Biotal Ltd, Cardiff, UK). WCG contained Lactobacillus buchneri, while WCL contained L buchneri, L plantarum and Pediococcus pentosaceus. Chemical composition, fermentation characteristics and in vitro digestibility were measured after 65 days of ensiling. Additive‐treated bi‐crops had lower (P < 0.05) concentrations of soluble N, ammonia N and lactic acid than the controls. Inoculant‐treated bi‐crops had higher (P < 0.001) acetic acid and lower (P < 0.001) residual water‐soluble carbohydrate (WSC) concentrations than FA‐treated bi‐crops. WCL‐treated bi‐crops had similar residual WSC concentrations to and higher (P < 0.05) starch concentrations than WCG‐treated bi‐crops. Unlike Magnus pea bi‐crops, Setchey pea bi‐crops treated with WCL had lower concentrations of ammonia N (P < 0.01) and acetic acid (P < 0.001) and higher concentrations of starch (P < 0.001) and lactic acid (P < 0.05) than those treated with WCG. For both bi‐crops, FA‐treated bi‐crops were more stable (P < 0.05) than inoculant‐treated or untreated silages, and the stability of inoculant‐treated and untreated silages was similar. Formic acid treatment was also the most effective at reducing WSC losses in the bi‐crop and pea silages. Inoculant treatment reduced proteolysis in these forages but did not prevent spoilage in the bi‐crops. Additive treatment reduced yeast counts but did not improve the fermentation in wheat silages. Copyright © 2004 Society of Chemical Industry
Nutrient utilisation in response to dietary supplementation of chicory inulin in growing pigs
Authors: Rideout Todd C , Fan Ming Z 
Published: May 2004

AbstractThe digestive and post‐absorptive utilisation of dietary crude protein (CP), calcium (Ca) and phosphorus (P) in response to dietary supplementation of chicory inulin extract was investigated with six Yorkshire barrows with an average initial body weight of 30 kg. The barrows were fed a corn (maize) and soybean meal‐based diet containing 0 or 50 g kg−1 chicory inulin extract according to a two‐period crossover design. The digestive utilisation of CP, Ca and P did not differ (P > 0.05) between the control and the inulin‐fed pigs. Furthermore, the post‐absorptive urinary loss of CP and Ca was not affected (P > 0.05) by 50 g kg−1 chicory inulin supplementation. However, inulin supplementation improved post‐absorptive P utilisation through a reduction (P = 0.01) in urinary P loss by 1.6 percentage units compared with the control group. In conclusion, dietary supplementation of 50 g kg−1 chicory inulin does not affect dietary CP and Ca utilisation but does reduce urinary P loss in growing pigs. Copyright © 2004 Society of Chemical Industry
The significance of critical processing steps in the production of dried egg albumen powder on gel textural and foaming properties
Authors: Hammershøj Marianne , Peters Lars V , Andersen Henrik J 
Published: May 2004

AbstractThe purpose of the present work was to study the variation in egg albumen functional properties as a function of seven selected processing steps from the initially raw liquid albumen to the final dried egg albumen powder. Albumen samples in six replicates were analysed for dry matter, pH, glucose, triglycerides, albumen gel properties (ie textural stress and Hencky strain, water‐ and protein‐binding capacity and gel colour L*, a*, b*), foaming properties (ie overrun, stability against drainage and bubble breakdown) and surface tension. The gel texture and water‐holding capacity significantly decreased during the processing steps from raw albumen through storage, centrifugation and ion exchange, whereas the final dry‐pasteurisation resulted in increased gel properties. Covalently linked protein polymers formed during the dry‐pasteurisation, as revealed by SDS‐PAGE, may explain this improvement. The foam overrun increased twofold during the three final steps of ultrafiltration, spray‐drying and dry‐pasteurisation compared with the raw albumen; however, the foam stability decreased, ie drainage and foam volume breakdown rates increased. The surface pressure increase was positively correlated with the foam overrun. This paper reveals at which processing steps the control of functional properties of egg albumen powder can take place. Copyright © 2004 Society of Chemical Industry
Influence of the stage of ripeness of plantains and some cooking bananas on the sensory and physicochemical characteristics of processed products
Authors: Yomeni MO , Njoukam J , Tchango Tchango J 
Published: May 2004

AbstractThe influence of the stage of ripening of the fruit of cultivars of plantain (French Sombre) and some cooking bananas (Dwarf Kalapua and Bluggoe) on the sensory and physico‐chemical characteristics of processed products was evaluated. Chips made from these cultivars at corresponding stages of ripeness had water contents less than 20 g kg−1 for fruits at stages 1 and 3 and less than 60 g kg−1 for those at stages 4 and 5. There was no significant difference (p > 0.05) between the ash contents of chips at different stages of ripeness for all the cultivars. Protein contents increased with increasing ripeness for all the cultivars; the fat contents decreased with increasing ripeness and varied from one cultivar to another. The available food energy was more than 4840 kcal kg−1 of chips for all the cultivars at all stages of ripeness. The best chips were obtained from fruits at stages 1 and 3. Flours obtained from the fruits of these cultivars at different stages of ripeness had water contents lower than 60 g kg−1. The fat, ash and protein contents were low, while the carbohydrate contents were high. For all the cultivars the yields of chips and flour were higher for the plantain cultivar (French Sombre) than for the cooking banana cultivars, irrespective of the stage of ripeness of the fruits. Cakes made from the different flours had good nutritional quality. The cakes and chips submitted for sensory evaluation were all accepted by consumers, although to differing extents. Fruits at stages 1 and 3 of ripeness which presented fewer problems during drying were the most suitable for the manufacture of flour for making cakes. Copyright © 2004 Society of Chemical Industry
Molecular Dynamics Simulations of Cellulose Oligomers: Conformational Analysis
Authors: Queyroy Séverine , Müller‐Plathe Florian , Brown David 
Published: May 2004

AbstractSummary: The results of classical molecular simulations of cellulose oligomers are presented here. The conformations of the chains in the high temperature melt, room temperature quenched melt and gas phase are compared with respect to various geometrical parameters including square end‐to‐end distances, glycosidic link torsion correlations, ring puckering and hydrogen bonding. The cellulose oligomer melts were relaxed at 800 K with molecular dynamics, and then cooled down in three different ways to obtain dense amorphous systems at 500 K and at room temperature. The sample resulting from the quench (step) shows too much similarity with the melt at 800 K. The two other cooling schemes (ramp, 2ramps) give very similar results for all quantities investigated. The relevance of previous single molecule calculations with respect to the dense amorphous systems is called into question. Comparisons between the chains in the dense systems and those in the gas phase reveal that, even for these relatively short stiff chains, differences exist in the preferred conformations. At high temperatures, where both systems are in equilibrium, the distribution of square end‐to‐end distances are both fairly smooth, but the gas phase clearly prefers more compact conformations. At 300 K, the differences are exacerbated as the equilibrium distribution for the gas phase shows a high proportion of folded conformers, whereas the nonequilibrium quenched systems necessarily retain the extended envelope of the higher temperature. Differences are also evident in the puckering, the rotation of the hydroxymethyl groups and the pattern of hydrogen bonds.The probability density distribution for the square end‐to‐end distance for octaose in the gas phase (light line) and in the dense phase (dark line) at 300 K.imageThe probability density distribution for the square end‐to‐end distance for octaose in the gas phase (light line) and in the dense phase (dark line) at 300 K.
Differential c‐myc expression profiles in normal human bronchial epithelial cells following treatment with benzo[a]pyrene, benzo[a]pyrene‐4,5 epoxide, and benzo[a]pyrene‐7,8‐9,10 diol epoxide
Authors: Fields Wanda R. , Desiderio Joseph G. , Leonard Randi M. , Burger Ellen E. , Brown Buddy G. , Doolittle David J. 
Published: May 2004

AbstractBronchial epithelial cells are often exposed to airborne mutagens that have the potential to induce genetic changes involved in the development of lung cancer. Although lung tumors often display alterations in the expression of oncogenes and/or tumor suppressor genes, the role of specific chemicals and/or metabolites in causing these alterations is not well defined. The polycyclic aromatic hydrocarbon (PAH) benzo[a]pyrene (B[a]P), a by‐product of combustion, is a prevalent airborne environmental mutagen and a constituent of cigarette smoke. The primary objective of this study was to compare the effect of B[a]P and two of its reactive metabolites, benzo[a]pyrene diol epoxide (BPDE or bay region epoxide) and benzo[a]pyrene‐4,5‐dihydroepoxide (BPE or K‐region epoxide), on expression of the proto‐oncogene c‐myc in normal human bronchial epithelial (NHBE) cells using a quantitative reverse transcriptase‐polymerase chain reaction (RT‐PCR) method. Changes in c‐myc gene expression were compared with DNA adduct formation, growth inhibition, and cell‐cycle progression as determined by 32P‐postlabelling, neutral red (NR), and flow cytometric analyses, respectively. None of the three test compounds altered the levels of 18S ribosomal RNA or β‐actin at the concentrations evaluated for c‐myc expression, indicating that nonspecific changes in gene expression induced by cytotoxicity, for example, were not present at the concentrations evaluated. Cells exposed to B[a]P exhibited a dose‐dependent increase in c‐myc expression; conversely, a dose‐dependent decrease in c‐myc expression was observed following BPDE exposure. A marginal but concentration‐dependent increase in c‐myc mRNA levels was observed following exposure to the K‐region epoxide. Our results demonstrated that, although B[a]P and its metabolites alter c‐myc expression, the parent compound and its metabolites produce unequal and contrasting effects on the expression of this gene. © 2004 Wiley‐Liss, Inc.
Reversible parkinsonism following heroin pyrolysate inhalation is associated with tetrahydrobiopterin deficiency
Authors: Heales Simon , Crawley Francesca , Rudge Peter 
Published: May 2004

AbstractA patient who inhaled heroin vapour (chasing the dragon), resulting in temporary parkinsonism, is described. A reversible deficiency of tetrahydrobiopterin, causing altered dopamine metabolism, is demonstrated as the metabolic basis of this aspect of the encephalopathy. © 2004 Movement Disorder Society
In vivo imaging of microglial activation with [11C](R)‐PK11195 PET in corticobasal degeneration
Authors: Gerhard Alexander , Watts Justin , Trender‐Gerhard Iris , Turkheimer Federico , Banati Richard B. , Bhatia Kailash , Brooks David J. 
Published: May 2004

AbstractCorticobasal degeneration (CBD) is a neurodegenerative parkinsonian disorder of unknown cause that shows considerable clinical heterogeneity. In CBD, activated microglia have been shown to be associated closely with the extensive tau pathology found in the affected basal ganglia, brainstem nuclei, and cortical regions. We report on the use of [11C](R)‐(1‐[2‐chlorophenyl]‐N‐methyl‐N‐[1‐methylpropyl]‐3‐isoquinoline carboxamide) (PK11195) positron emission tomography (PET), a marker of peripheral benzodiazepine binding sites (PBBS) that are expressed by activated microglia, to demonstrate in vivo the degree and distribution of glial response to the degenerative process in 4 patients with CBD. Compared with normal age‐matched controls, the CBD patient group showed significantly increased mean [11C](R)‐PK11195 binding in the caudate nucleus, putamen, substantia nigra, pons, pre‐ and postcentral gyrus, and the frontal lobe. [11C](R)‐PK11195 PET reveals a pattern of increased microglial activation in CBD patients involving cortical regions and the basal ganglia that corresponds well with the known distribution of neuropathological changes, which may therefore help to characterize in vivo the underlying disease activity in CBD. © 2004 Movement Disorder Society
NF‐κB p65 involves in reperfusion injury and iNOS gene regulation in skeletal muscle
Authors: Qi Wen‐Ning , Chaiyakit Pruk , Cai Yongting , Allen Diane M. , Chen Long‐En , Seaber Anthony V. , Urbaniak James R. 
Published: May 2004

AbstractThis study investigated the effects of inhibition of NF‐κB activation on microcirculation and inducible NOS expression in reperfused rat cremaster muscle. The muscle from 16 rats underwent 5‐h ischemia and 90‐min reperfusion. Each rat received NF‐κB inhibitor pyrrolidine dithiocarbamate (PDTC, 150 mg/kg) or phosphate‐buffered saline 15 min before reperfusion. Results showed that PDTC treatment had a significant overall increase in muscle blood flow during reperfusion. Blood flow more rapidly recovered to and over baseline in the PDTC‐treated group than in controls, with a significant difference at 10–30 min and 70–90 min. Expression of iNOS mRNA had a 167‐fold increase from normal in controls, but was significantly (P < 0.05) reduced to a 63‐fold increase in PDTC‐treated muscles. In addition, PDTC treatment significantly (P < 0.05) decreased a reperfusion‐induced increase in activated NF‐κB p65 and nuclear p65 protein. Our results suggest that NF‐κB is involved in I/R injury and that inhibition of NF‐κB p65 activation affords protection against I/R injury, perhaps via downregulating expression of iNOS transcription. © 2004 Wiley‐Liss, Inc.
Existence and uniqueness of bounded weak solution for non‐linear parabolic boundary value problem with equivalued surface
Authors: Li Fengquan 
Published: May 2004

AbstractIn this paper, we discuss the existence and uniqueness of bounded weak solution for non‐linear parabolic boundary value problem with equivalued surface and correct the mistake in Zhang Xu (Math. Meth. Appl. Sci. 1999; 22: 259). The approach is based on L∞ estimate of solution. Copyright © 2004 John Wiley & Sons, Ltd.
A relaxed model and its homogenization for nematic liquid crystals in composite materials
Authors: Shen Quan , Calderer M. Carme 
Published: May 2004

AbstractWe analyse a model for equilibrium configurations of composite systems of nematic liquid crystal with polymer inclusions, in the presence of an external magnetic field. We assume that the system has a periodic structure, and consider the relaxed problem on the unit length constraint of the nematic director field. The relaxation of the Oseen–Frank energy functional is carried out by including bulk as well as surface energy penalty terms, rendering the problem fully non‐linear. We employ two‐scale convergence methods to obtain effective configurations of the system, as the size of the polymeric inclusions tends to zero. We discuss the minimizers of the effective energies for, both, the constrained as well as the unconstrained models. Copyright © 2004 John Wiley & Sons, Ltd.
A Kronecker product approximate preconditioner for SANs
Authors: Langville Amy N. , Stewart William J. 
Published: May 2004

AbstractMany very large Markov chains can be modelled efficiently as stochastic automata networks (SANs). A SAN is composed of individual automata which, for the most part, act independently, requiring only infrequent interaction. SANs represent the generator matrix Q of the underlying Markov chain compactly as the sum of Kronecker products of smaller matrices. Thus, storage savings are immediate. The benefit of a SAN's compact representation, known as the descriptor, is often outweighed by its tendency to make analysis of the underlying Markov chain tough. While iterative or projections methods have been used to solve the system πQ=0, the time until these methods converge to the stationary solution π is still unsatisfactory. SAN's compact representation has made the next logical research step of preconditioning thorny. Several preconditioners for SANs have been proposed and tested, yet each has enjoyed little or no success. Encouraged by the recent success of approximate inverses as preconditioners, we have explored their potential as SAN preconditioners. One particularly relevant finding on approximate inverse preconditioning is the nearest Kronecker product approximation discovered by Pitsianis and Van Loan. In this paper, we extend the nearest Kronecker product technique to approximate the Q matrix for an SAN with a Kronecker product, A1 ⊗ A2 ⊗…⊗ AN. Then, we take M = A ⊗ A ⊗…⊗ A as our SAN NKP preconditioner. Copyright © 2004 John Wiley & Sons, Ltd.
Quality improvements in extruded meshes using topologically adaptive generalized elements
Authors: Chalasani Satish , Thompson David 
Published: May 2004

AbstractThis paper describes a method to extrude near‐body volume meshes that exploits topologically adaptive generalized elements to improve local mesh quality. Specifically, an advancing layer algorithm for extruding volume meshes from surface meshes of arbitrary topology, appropriate for viscous fluid flows, is discussed. First, a two‐layer reference mesh is generated from the layer initial surface mesh by extruding along the local surface normals. The reference mesh is then smoothed using a Poisson equation. Local quality improvement operations such as edge collapse, face refinement, and local reconnection are performed in each layer to drive the mesh toward isotropy and improve the transition from the extruded mesh to a void‐filling tetrahedral mesh. A few example meshes along with quality plots are presented to demonstrate the efficacy of this approach. Copyright © 2004 John Wiley & Sons, Ltd.