bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characteristics of skeletal muscle growth and protein turnover in a fast-growing rat strain
Authors: Bates P. C. , Millward D. J. 
Published: May 2005

1. Protein turnover and muscle composition has been studied in rat skeletal muscle throughout development in a relatively-fast-growing rat strain.2. Muscle growth involved an increase in the total DNA and in the DNA-unit size as indicated by protein: DNA. As a result of the latter increase together with no change in RNA: DNA, the RNA concentration fell throughout development.3. Rates of protein synthesis measured in vivo by the continuous intravenous infusion method fell throughout development from 15.6%/d at 25 d to 4.46%/d at 320 d, and these changes reflected mainly the fall in RNA concentration, since there was no marked change in the rate of protein synthesis per unit RNA.4. The rate of protein degradation, measured as the difference between rates of protein synthesis and growth, fell from 9.82%/d at 25 d to 4.46%/d at 320 d.5. When these changes in protein turnover throughout development are compared with measurements made previously in a slow-growing strain it would appear that the faster growth was achieved as a result of increased efficiency of protein synthesis (defined as net synthesis: over-all synthesis) and this occurred mainly because of lower rate of protein degradation.
Characteristics of the rumen proteolysis of fraction I (18S) leaf protein from lucerne (Medicago sativa L)
Authors: Nugent J. H. A. , Mangan J. L. 
Published: May 2005

1. The rate of proteolysis of fraction 1 (18S) leaf protein in the rumen of sheep and cattle was affected by diet and the rate on fresh lucerne (Medicago sativa L) was three to nine times the rate on a hay + concentrate diet.2. Simultaneous rumen fermentations in vivo and in an artificial rumen showed that the rates of proteolysis of fraction I in vitro was approximately 80% of the rates in sheep.3. Using 14C uniformly-labelled fraction I protein at low concentrations, proteolysis exhibited 1st-order kinetics. Over a wide range of protein concentrations the velocity v. substrate concentration curve showed Michaelis–Menten characteristics typical of an enzyme-catalysed reaction. With rumen fluid from a hay + concentrate-fed sheep the maximum velocity was 2.6 mg protein nitrogen/1 per min and the Michaelis constant was 75 mg nitrogen/1.4. Rapid adsorption of 14C-labelled fraction I protein onto bacterial cells preceded proteolysis.5. Sucrose-density-gradient analysis showed initial incorporation of 14C from protein into rumen bacteria followed by partial transfer to rumen protozoa.6. No peptides were detected during proteoiysis showing that the rate-limiting step occurred during the initial stages of proteolysis. Only small amounts of free amino acids were released except for leucine, isoleucine, valine and ornithine, which showed significantly increased levels.7. Volatile fatty acids were the main 14C-labelied end products and were rapidly produced in descending concentrations: acetate > propionate > 3-methyl + 2-methyl butyrate > butyrate > isobutyrate > valerate.
Utilization of amino acid analogues in diets of young turkeys
Authors: Parsons C. M. , Potter L. M. 
Published: May 2005

1. The relative potencies of three lysine, one tryptophan and six methionine analogues to their corresponding L-amino acids were determined.2. Male poults, 9 d of age, were used in five 14 d experiments. Experimental diets were formed by adding increasing levels of an amino acid (L-isomer) or its analogues to a basal diet deficient in the test amino acid. Multiple-regression analyses of body-weight gainv. level of added or amount of consumed amino acid supplement were computed. Relative potencies of the analogues were calculated using the slope-ratio technique.3. Type of independent variable used in the regression analyses did not significantly affect relative potency values.4. From regression analyses with level of added amino acid supplement as the independent variable, relative potencies (with 95% confidence intervals) on a molar basis of each analogue as a percentage of the respective amino acid were: hydroxymethyl-L-tryptophan monohydrate 9 (−12, 22), DL-methionine sulphone 3 (−68, 36), DL-methionine hydantoin −10 (−63, 29), L-cystine 8 (−31. 40), DL-methionine sulphoxide 59 (24, 95) and 46 (18, 74), oleoyl-DL-methionine 77 (37, 138), methionine hydroxy analogue calcium 93 (65, 128), dicocoyl-L-lysine 23 (5, 41). bis-hydroxymethyl-L-lysine-calcium 69 (54, 82) and 41 (−1, 80), mono-hydroxymethyl-L-lysine-calcium 89(77, 101) and 99(65, 134).5. The first four analogues appeared to have little or no amino acid activity. DL-methionine sulphoxide, dicocoyl-L-lysine, and bis-hydroxymethyl-L-lysine-calcium were partially active. Relative potencies of oleoyl-DL-methionine, methionine hydroxy analogue calcium, and mono-hydroxytmethyl-L-lysine-calcium were not significantly different from those of their corresponding amino acids.
Zinc transport proteins in plasma
Authors: Chesters J. K. , Will Marie 
Published: May 2005

1. Both albumin and transferrin have been suggested as carriers of zinc in plasma. Their relative importance in Zn transport was therefore investigated as a preliminary to a study of the rates of passage of Zn through plasma.2. The apparent log stability constant for Zn binding to human apotransferrin at pH 7·4 was estimated to be approximately 5·9 which is substantially lower than previous reports of 7·0 for the corresponding value for Zn binding to albumin (Giroux & Henkin, 1972).3. When the relative abilities of human albumin and apotransferrin to compete for Zn with low-molecular-weight chelators were compared at the same relative concentrations of these proteins as are found in plasma, albumin retained substantially more Zn than transferrin.4. It seems likely that albumin acts as the major transport protein for Zn in plasma of most species, Zn also being present firmly bound to α2-macroglobulin.5. In porcine plasma or serum however, there were three major Zn-binding proteins, two of which were probably albumin and α2-macroglobulin. The nature of the third component remains unknown but it appeared to have a molecular weight of between 100000–140000, it was precipitated by 2·2 M-ammonium sulphate and by 150 gpolyethylene glycol/l.6. There were no significant differences in Zn distribution in plasma of porcine blood obtained from the aorta, the posterior vena cava or from the hepatic portal vein but use of heparin as an anticoagulant altered the normal pattern of distribution of Zn in plasma.
A vailability to pigs of amino acids in cereal grains
Authors: Taverner M. R. , Hume I. D. , Farrell D. J. 
Published: May 2005

1. Endogenous levels of amino acids in ileal digests were determined as the output from pigs given protein-free diets and by extrapolation to zero intake of linear regressions of ileal amino acid outputv. dietary amino acid intake. The protein-free diets included 0 or 50 g cellulose/kg and extrapolations were made from two series of four diets which contained graded levels of wheat or barley as the only source of protein. Within each series, dietary fibre level (mg/g) was maintained at approximately 140 or 190 neutral-detergent fibre (NDF) respectively. Endogenous amino acid levels in faeces were also determined.2. Endogenous amino acid output in faeces was linearly related to dietary fibre level; endogenous ileal output increased with dietary fibre up to approximately 100 mg NDF/g, after which endogenous output no longer increased.3. The amino acid composition of endogenous ileal protein varied little among levels of output and among different experiments. The composition appears to be determined by the predominance of mucin protein, the slow absorption of some amino acids and the methods commonly used to measure output. The very high levels of proline and glycine in ileal digesta seemed characteristic only of protein-free and low-protein diets.4. The amino acid composition of endogenous faecal protein also varied little among different estimates, but was considerably different from that of endogenous ileal protein. Furthermore, the similarity of bacterial and faecal proteins suggested that much of the endogenous faecal protein was of bacterial origin.
The digestion by cattle of grass silage made with formic acid and formic acid–formaldehyde
Authors: Thompson D. J. , Beever D. E. , Lonsdale C. R. , Haines M. J. , Cammell S. B. , Austin A. R. 
Published: May 2005

1. A primary growth crop of perennial ryegrass (Lolium perenneL., cv. S23) was partially wilted and ensiled after the application of eitherformic acid–water (1:3, w/v; 7.1 1/t fresh herbage; control diet C) or formic acid–formaldehyde (1:1, w/w; 8·81/t fresh herbage; formaldehyde treated diet F) which supplied 50gHCHO/kg crude protein (nitrogen (N) × 6·25). The two silages were fed separately and a third diet comprising formaldehyde-treated silage, supplemented with urea (20 g/kg dry matter dm) at the time of feeding was also examined (dietFU).2. The three diets were fed at a level of 16 g dm/kg live weight to six 3- to six-month-old cattle fitted with rumen and re-entrant duodenal cannulas in two 3 × 3 LatinSquare experiments, and measurements were made of the digestion of energy, carbohydrateand N.3. The formaldehyde-treated silage had a lower content of fermentation acids and ammoma-N and a higher content of water-soluble carbohydrate and total amino acids. The apparent digestibility of organic matter, energy and N were depressed (P < 0·05, P < 0·05 and P < 0·01 respectively) by treatment with formaldehyde, but cellulose and neutral-detergent fibre digestibility were unaffected.4. Within the rumen the digestion of organic matter, cellulose and neutral-detergent fibre were unaffected by formaldehyde treatment or supplementation with urea. Microbial protein synthesis in the rumen was similar for the three diets (average 131 g/kg apparently digested organic matter in the rumen).5. The application of formic acid-formaldehyde increased (P < 0·05) the amount of food protein escaping degradation in the rumen (4·76 diet C, 6·89 diet F; 7·07 diet FU g/kg protein intake). The contribution of amino acidsof dietary origin al the duodenum increased (P < 0·05) from 50 (diet C) to 80 (diet F) and 82 (diet FU) g/kg DM intake, and the flow of total amino acids at the duodenum was 33% higher (P < 0·001) in cattle fed formic acid–form aldehyde silage diets compared withthe control silage due to the reduction in degradation of protein at ensiling and in therumen.
The digestive capacity of the caecum-colon and the value of the nitrogen absorbed from the hind gut for protein synthesis in pigs
Authors: Just A. , Jørgensen H. , Fernández J. A. 
Published: May 2005

1. The aim of the investigation was to study the effects of lysine, methionine, crude protein, a complete balanced diet, maize starch and potato starch infused continuously into the caecum on the digeslibilly of the nutrients, urinary nitrogen excretion and N balance in the presence of a normal or a depressed (modified) microflora.2. The effects of the infused nutrients on digestibility differed when diets supplemented with antibiotics were compared with unsupplemented diets.3. Infused lysine improved the digestibility of crude protein (0·004/g lysine), crude fibre (0·01/g lysine), gross energy (0·003/g lysine) and lysine (0·03g lysine) when the diets were not supplemented with antibiotics.Infused lysine, methionine and crude protein seemed to be of very little value for protein synthesis in the pigs, as the effects on N balance, although positive, were very small.5. Despite the fact that a part of the infused lysine passed through the caecum-colon and into the faeces intact, the effect on N balance was negligible, indicating that the ability to absorb amino acids through the gut wall in the caecum-colon was very poor.6. Crude protein, a complete balanced diet, maize starch and potato starch infused into the caecum were digested almost as well as if they had been given orally, thus demonstrating the large digestive capacity of the caecum-colon.
Crystallization and preliminary X-ray analysis of strictosidine synthase and its complex with the substrate tryptamine
Authors: Koepke Juergen , Ma Xueyan , Fritzsch Günter , Michel Hartmut , Stöckigt Joachim 
Published: June 2005

Strictosidine synthase (STR1) is a central enzyme that participates in the biosynthesis of almost all plant monoterpenoid indole alkaloids. After heterologous expression in Escherichia coli, crystals of STR1 and its substrate complex with tryptamine were obtained by the hanging-drop technique at 302–304 K with potassium sodium tartrate tetrahydrate as precipitant. All crystals belong to space group R3. The native STR1 crystals diffract to 2.95 Å and have unit-cell parameters a = b = 150.3, c = 122.4 Å. The tryptamine complex crystals diffract to 2.38 Å, with unit-cell parameters a = b = 147.3, c = 122.3 Å.
Closed‐form solution of monocular vision‐based relative pose determination for RVD spacecrafts
Authors: Zhang Shijie , Cao Xibin 
Published: June 2005

PurposeTo give a closed‐form solution of the relative pose determination problem based on monocular vision during final approach phase of spacecraft Rendzvous and Docking.Design/methodology/approachBased on the assumption of scaled orthographic projection, the model of perspective projection is simplified by representing the relative attitude using unit quaternion. Then a closed‐form solution is derived. Subsequently, this study correct the approximate solution to compensate the error caused by the assumption of scaled orthographic projection.FindingsExtensive simulation studies were conducted for the validation of the proposed algorithm using Matlab™. When there are no relative attitudes between RVD spacecrafts, target distance for camera=2‐20 m. The simulation results show that the largest relative error of corrected relative position parameters is about 0.12 percent. When distance between RVD spacecrafts exceeds 5 m, the largest error of corrected relative attitude parameters are less than 0.3°. When the distance between spacecrafts are constant, the relative attitude parameters are changed, respectively, the simulition results show the largest relative error of relative position is 1 percent, and largest error of estimated relative attitude is 1.2°, when a relative attitude angle reaches 20°.Originality/valueThe proposed algorithm avoids the multiple results problem in determining the relative position and attitude parameters and the closed‐form solution is simple and effective, is more suitable for on‐board implementation.
Control of longitudinal movement of a plane using combined model reference adaptive control
Authors: Duarte‐Mermoud Manuel A. , Rioseco Jaime S. , González Rodrigo I. 
Published: June 2005

PurposeTo apply and simulate under different conditions, the combined model reference adaptive control (CMRAC) technique to control the pitch angle in a subsonic plane. Comparisons with the classical PID controller and the adaptive direct MRAC are also performed.Design/methodology/approachThe methodology used in this work is the CMRAC. This is a relatively new adaptive control technique which combines the information coming from the identification procedure as well as that from the direct control scheme, and use it in the adaptive laws. The identification parameters and the controller parameters are simultaneously adjusted using the identification error, the control error and the so‐called close‐loop identification error. This combination has shown to improve the transient behavior of the adaptive systems.FindingsThis control scheme has been tested by simulation on a model of a CESSNA 182 plane, to control the pitch angle (longitudinal movement). The results have been compared with other control approaches such as the classical PID and the adaptive direct MRAC. Although the PID control satisfies all the control specifications as much as the CMRAC, it is not able to adapt when changes in the operating conditions occur, as in the case of the CMRAC. The direct MRAC does no perform well in this study.Research limitations/implicationsThe implementation at practical level remains to be studied and analyzed, to verify the theoretical and simulation results presented here.Practical implicationsThe main advantage of the proposed method is that it behaves well even under different operating conditions, which is one of the most important characteristics for an implementation at practical level.Originality/valueIt is the first time in the control literature that the CMRAC is applied to control the pitch angle of a plane in a longitudinal movement. The results are quite promising remaining the practical implementation to verify the performance of the proposed scheme under real conditions.
Hybrid design methods of cascade profile based on variational principles
Authors: Zheng Yao , Gao‐Lian Liu , Xiao‐Jiang Wu 
Published: June 2005

PurposeProvides two hybrid methods for the aerodynamic design of cascade profiles, of which the design constraints are the combination of aerodynamic and geometric conditions.Design/methodology/approachIn the first method, the design constrain is composed of the velocity (or pressure) distribution on part of the blade surface and the geometry of the rest part. In the second method, the aerodynamic load distribution, i.e. the pressure difference between the suction and pressure surfaces, and the blade thickness distribution are employed as the design constrain. These constraints, together with all the other boundary conditions, are involved in the stationary conditions of a variational principle. The solution domain, i.e. the blade‐to‐blade passage, is transformed into a square in the image plane, while the blade contour is projected to a straight line; thus, the difficulty caused by the unknown geometry of profile is avoided. Finite element method is employed to produce the calculation code.FindingsApplications show the accuracy and the flexibility of the two methods, which can satisfy the different needs from blade design. Finally, the possibility of combining the hybrid methods with the through‐flow method is discussed, which would develop the present methods to three‐dimensional design of cascades.Research limitations/implicationsThe design methods are limited to frictionless flow.Practical implicationsA design software of cascade profiles based on this method has been developed, and will be provided to the engineering users for cascade design.Originality/valueThe hybrid methods developed in this paper can satisfy the demands from different aspects of engineering designs: aerodynamics, strength, manufacture, etc.
Library participation in campus web portals: an initial survey
Authors: Stoffel Bruce , Cunningham Jim 
Published: June 2005

PurposeTo determine the extent and nature of library involvement in campus portal development.Design/methodology/approachCampus technology staff from US colleges and universities participating in the JA‐SIG uPortal open‐source software project were surveyed.FindingsAll respondents indicated having an active campus portal. A majority of respondents had at least one library feature on their campus portal. Some library features included automated display of information specific to the portal user such as library account information. Collaboration between campus and library staff was a common theme among institutions successfully deploying library features.Research limitations/implicationsFindings are based on a small sample of campuses currently deploying portals. Recommended follow‐up studies include surveys of institutions using proprietary portal software and surveys of library staff and end‐users.Originality/valueWhile considerable research has been done on library portals, this paper is unique in its exploration of library participation in broader campus portal initiatives. Portal features discussed and illustrated in this paper might serve as models for libraries interested in developing a presence on their campus portal.
Visibility as a factor in library selection of ready reference web resources
Authors: Sowards Steven W. 
Published: June 2005

PurposeTo determine the most popular entries on library ready reference web sites and the role of visibility in the selection of resources.Design/methodology/approachReady reference web sites of 100 American libraries were examined, for a census of the most frequently selected online resources. The dates of news, library and online media coverage were considered for specific tools, to explain their prominence.FindingsEarly publicity for web tools was found to be an important element in their relative popularity as choices for library web sites.Research limitations/implicationsThe date on which a given web resource became well known among librarians can only be estimated from media reports, not proved. Additional study could establish the frequency with which libraries modify their ready reference web sites and investigate why other resources of comparable quality have not become as popular.Originality/valueThe paper shows that early visibility plays a role in librarians' selection of web resources that is rarely mentioned in discussions of selection criteria.
Assessing Auburn University Library's Tiger Information Literacy Tutorial (TILT)
Authors: Noe Nancy W. , Bishop Barbara A. 
Published: June 2005

PurposeDuring Spring semester 2001, Auburn University Libraries launched the Tiger Information Literacy Tutorial (TILT), based on the Texas Information Literacy Tutorial, designed by librarians at the University of Texas at Austin. This work assesses the effectiveness of the tutorial.Design/methodology/approachIn‐depth analysis of data collected over three semesters is presented.FindingsFollowing the Texas model, Auburn's TILT is comprised of three modules, covering searching, selecting, and evaluating information resources. Overall student perceptions of the tutorial, including technology difficulties, is reviewed; and students' personal views of their own research skills are discussed. The online information tutorial was viewed as effective, with the data indicating a need for additional study and improvement.ValueAs advances are made in computer‐aided and hypermedia‐aided instruction, the tutorial will continue to evolve as a learning tool.
Was this guide helpful? Users' perceptions of subject guides
Authors: Courtois Martin P. , Higgins Martha E. , Kapur Aditya 
Published: June 2005

PurposeMost academic libraries make subject or research guides available on their web sites. Little is known, however, in terms of user satisfaction with guides. This study examines methods used to evaluate guides and reports on an online survey placed on each of more than 80 web‐based guides provided by Gelman Library, George Washington University.Design/methodology/approachThe survey, borrowing an approach used by Amazon.com and other web sites, consisted of a single question – Was this guide useful – and a comments box.FindingsTwo hundred ten responses were received during Fall semester 2003. Fifty two percent of responses rated guides as Very Helpful or Somewhat Helpful, while 40 percent gave ratings of Not Helpful or a Little Helpful.Originality/valueAlthough limited in scope, this simple survey revealed positive elements of the guides and identified problems that could be addressed immediately. The survey also helped to identify larger issues that will benefit from additional user input.