bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of dietary fatty acids on the intestinal permeability of marker drug compounds in excised rat jejunum
Authors: Vine D F , Charman S A , Gibson P R , Sinclair A J , Porter C J H 
Published: October 2002

Abstract
The aim of this study was to explore the effects of diets containing saturated fatty acids (SFA), monounsaturated fatty acids (MUFA), and ω-3 and ω-6 polyunsaturated fatty acids (ω-3 and ω-6 PUFA, respectively) on the passive and active transport properties of rat jejunum using marker compounds. Rats were fed diets supplemented with 18.4% (w/w) lipid (4 groups) or standard rat chow (1 group) for a period of 30 days. At the end of the dietary period, mucosal scrapings were taken for the determination of membrane phospholipids, and the apparent jejunal permeability of radiolabelled marker compounds was determined using modified Ussing chambers. Changes in the phospholipid content of the brush border membrane reflected the different lipid content of the diets. The passive paracellular permeability of mannitol was not significantly affected by the fatty acid composition of the diet, although there was a trend toward decreased mannitol permeability in the rats fed both the ω-3 and ω-6 PUFA diets. In comparison, the transcellular diffusion of diazepam was reduced by 20% (P &lt; 0.05) in rats fed diets supplemented with ω-3 and ω-6 PUFA. In the lipid-fed rats, the serosal to mucosal flux of digoxin, an intestinal P-glycoprotein substrate, was reduced by 20% (P &lt; 0.05) relative to the chow-fed group, however there were no significant differences between the different lipid groups. The active absorption of D-glucose via the Na+-dependent transport pathway was highest in the SFA, MUFA and PUFA ω-3 dietary groups, intermediate in the low-fat chow group and lowest in the PUFA ω-6 group, and was positively correlated with short-circuit current. These studies indicate that dietary fatty acid changes can result in moderate changes to the active and passive transport properties of excised rat jejunum.
Selective and sustained occupancy of prostatic α1-adrenoceptors by oral administration of KMD-3213 and its plasma concentration in rats
Authors: Okura T , Yamada S , Abe Y , Kimura R 
Published: October 2002

Abstract
This study examined the ex-vivo occupancy by KMD-3213 of α1-adrenoceptors in the prostate and other tissues of rats in terms of tissue selectivity and duration of occupancy in relation to plasma concentration. Oral administration of KMD-3213 (0.2–20.2μmol kg−1, 0.5 h) dose-dependently decreased [3H]prazosin binding sites (Bmax) in the prostate (42–74%) and submaxillary gland (54–88%) compared with the control value. In contrast, there was only a slight change in the Bmax values in the spleen and cerebral cortex of KMD-3213-treatedrats. The α1-adrenoceptor occupancy in the prostate and submaxillary gland was increased, with plasma free concentration of KMD-3213 at 0.5 h after oral administration of KMD-3213 (0.6–20.2 μ mol kg−1). The receptor occupancy in these tissues was much greater than that in the spleen, heart or cerebral cortex. After oral administration of KMD-3213 (6.1 μ mol kg−1), the α1-adrenoceptor occupancy in the prostate and submaxillary gland occurred rapidly, in parallel with the rise in the plasma concentration of the drug, and it lasted for at least 24 h, despite a remarkable decrease in the plasma concentration. It is concluded that KMD-3213 may produce fairly selective and sustained occupancy of α1-adrenoceptors in the prostate, a target organ for treatment of bladder outlet obstruction in patients with benign prostatic hyperplasia.
Genetic loci for pathological myopia are not associated with juvenile myopia
Authors: Mutti Donald O. , Semina Elena , Marazita Mary , Cooper Margaret , Murray Jeffrey C. , Zadnik Karla 
Published: October 2002

AbstractThe purpose of this study was to evaluate chromosomal regions previously linked to pathological myopia for linkage to juvenile myopia in a sample of myopic children and their families. Of 125 families with a myopic child participating in the Orinda longitudinal study of myopia, 53 submitted 221 buccal swab samples for genetic analysis. Myopia in proband children was defined as −0.75 D or more myopia in both meridians on cycloplegic autorefraction (1% tropicamide). Affected status in parents and siblings was obtained by survey. DNA was extracted from buccal mucosal cells, amplified by polymerase chain reaction (PCR), and then analyzed with seven markers for chromosome 12 and five markers for chromosome 18 in the regions previously associated with pathological myopia. LOD scores were not significant for any marker tested. The largest positive LOD score was 0.15 for GATA30F04. Model‐free methods using a SimIBD approach suggested a possible linkage at one marker, GATA6H09 (P = 0.003), but these results were not supported by transmission disequilibrium test (TDT) analysis. The statistical power to detect LOD scores of ≥1.0, assuming homogeneity, was estimated at 93.2%. We found no confirmatory evidence of linkage between juvenile myopia and regions of chromosomes 12 and 18 previously associated with pathological myopia. © 2002 Wiley‐Liss, Inc.
Real‐time quantitation of hepatitis B virus (HBV) DNA in tumorous and surrounding tissue from patients with hepatocellular carcinoma
Authors: Zanella Isabella , Rossini Angelo , Domenighini Daniela , Albertini Alberto , Cariani Elisabetta 
Published: October 2002

AbstractFew data are available on the levels of HBV DNA in liver tissue of patients with hepatocellular carcinoma. In this study, HBV DNA was quantitated by a TaqMan real‐time PCR method and results were normalised to an endogenous reference gene. The assay could detect reproducibly viral sequences from over 107 to less than 50 copies/μg of liver DNA. The HBV DNA content in liver samples from 11 HBsAg‐positive patients (median: 105 copies/μg of DNA) was significantly higher (P < 0.001) compared to the viral DNA concentration detected in liver samples from 15 of 25 HBsAg‐negative patients (median: 2.6 × 102 copies/μg). A liver DNA amount ≥1 HBV DNA copy per cell was detected in half of tissue samples from HBsAg‐positive patients, and in none from HBsAg‐negative ones. Liver tissue HBV DNA content was significantly higher in anti‐HCV‐negative than in anti‐HCV‐positive cases (P < 0.001). These results show that the quantitation of liver HBV DNA by real‐time PCR can be useful to understand HBV state in hepatocellular carcinoma and viral interplay in patients with multiple viral infections. J. Med. Virol. 68:494–499, 2002. © 2002 Wiley‐Liss, Inc.
Multiculturalism, universalism, and science education: In search of common ground
Authors: Siegel Harvey 
Published: October 2002

AbstractMulticulturalism's proper place in science education has been the subject of considerable controversy in the recent science education literature. It is the theme of a recent symposium in this journal, which raises and treats a wide range of issues with important ramifications for science education. A key issue—and the one on which I focus—is whether (and if so to what extent) a multicultural approach to science education is compatible with a “universalist” conception of science. My main aim is to show that there is actually much more agreement between “universalists” and multicultural “localists” concerning that compatibility than might be apparent at first glance. A second aim is to defend the former from criticisms made in the symposium papers. I first attempt to make clear what “universalism” does, and does not, involve. I then explore the justification of multicultural science education, and suggest both that that justification is moral (rather than epistemological) in nature; and that if science education is indeed obliged to embrace multiculturalism, that obligation must itself be understood to be a culturally transcendent one. Finally, I address several curricular issues treated in the symposium papers. The overall conclusion is that the most defensible conception of science education is one in which it is conceived to be both multicultural and universal. © 2002 Wiley Periodicals, Inc. Sci Ed 86:803–820, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/sce.1052
Designing production planning and control systems
Authors: Van Dierdonck Roland , Miller Jeffrey G. 
Published: October 2002

AbstractThis paper presents a contingency model designed to explain aggregate differences in the specifications for production planning and control systems across firms. The specifications for a firm's system, stated broadly in terms of the investment in information processing systems and organizational integrativeness, are related to that firm's competitive strategy and environment. An analysis of data from a limited sample of companies, and a panel of managers, provides insights into the applicability of the concepts used in the model, and its potential usefulness.
The effect of inventory costs on the LIFO layer liquidation decision
Authors: Cottell Philip G. , Patton Jon M. 
Published: October 2002

AbstractDue to double digit inflation during the latter part of the past decade, many companies have switched to the LIFO method of inventory valuation. LIFO layer liquidation occurs whenever a company which uses the LIFO inventory valuation method decides to reduce ending inventory to a level below beginning inventory. During inflationary periods, a company that allows this liquidation to occur will have to pay higher federal income taxes. This paper develops a decision rule of whether or not management should make a special purchase to avoid LIFO layer liquidation.The tradeoffs involved with this special purchase are reduced federal income taxes coupled with higher carrying costs and order or setup costs. Since some carrying costs are tax deductible and some are not, most of the carrying costs are considered individually in developing the decision model.The tax deductible costs that are considered are the cost of capital, property tax, insurance costs, handling costs, and warehouse costs. The carrying costs considered that are not tax deductible are the risk or probability of deterioration and obsolescence.Since the costs and tax payment occur at different points in time, the present value of each of these transactions are made for comparison purposes. The decision rule is based on a comparison between the present value of these costs and the present value of the cost of a LIFO layer liquidation. An example is then used to illustrate the decision rule.
Precedence diagramming method: Some unusual characteristics and their implications for project managers
Authors: Wiest Jerome D. 
Published: October 2002

AbstractThe Precedence Diagramming Method, with its activity‐on‐node network and additional precedence relationships, offers an easier and more flexible network approach to modeling large projects than conventional PERT/CPM. But the new relationships (start‐to‐start and finish‐to‐finish constraints) can change some of the basic notions of critical path methodology, including the concept of a critical path itself. Calculations of early and late job start times are affected, along with total slack. Traditional methods of shortening a project by crashing jobs on the critical path can occasionally have anomalous effects. These little‐known characteristics of PDM are discussed, along with their implications for project managers, analysts, and other users of network methodology. Suggestions are made for improving the information available in computer printouts of PDM networks and for avoiding some of the anomalous effects. While PDM improves the project planner's ability to more simply and accurately model large projects, users should be aware of and able to effectively deal with its sometimes peculiar characteristics.
Emergency ambulance location using the contiguous zone search routine
Authors: Fitzsimmons James A. , Srikar Bellur N. 
Published: October 2002

AbstractThis paper reports on a study to select permanent emergency ambulance sites for the city of Austin, Texas. A facility location algorithm referred to as the contiguous zone search routine (CZSR) was developed to capitalize on the availability of a large data base of interzone travel times. This algorithm was coupled to an existing emergency medical system simulation model (CALL) to permit systematic evaluations of system performance directed at improving average response time. This combination of a simulation model and heuristicsearch routine permitted a degree of model realism not available with deterministic location algorithms currently in use. The output from the system simulation provided the city with a rich description of system performance to evaluate the desirability of locations selected by the heuristic search routine and a set of joint use sites selected by the city. A final analysis confined to the set of joint use sites identified, in priority order, twelve locations for EMS vehicles to be phased in over a five year period. The paper concludes with some observations on the process of public sector planning.
Requirements planning systems in the health care environment
Authors: Steinberg Earle , Khumawala Basheer , Scamell Richard 
Published: October 2002

AbstractAn important problem confronting health care administration is cost containment in hospitals. Much of the current high costs can be traced directly to outdated procedures in materials management leading to waste, excessive inventory and unnecessary obsolescence of expensive short shelf life items. In this paper, we illustrate how a modern requirements planning system for surgical supplies was developed for a private hospital in Houston and used to effectively hold inventory levels to the minimum required to support a detailed schedule of surgical procedures. We also discuss some specific problems involved in the transfer of manufacturing technology to the hospital setting.
The impact of a rolling schedule in a multi‐level MRP system
Authors: Blackburn Joseph D. , Millen Robert A. 
Published: October 2002

AbstractThis paper presents a cost performance comparison of different lot‐sizing algorithms under multi‐level rolling schedule conditions. Most multi‐level studies have focused on fixed horizon problems, omitting an important characteristic of an operating MRP system. The results indicate that, under certain conditions, the computationally simple Silver‐Meal heuristic provides lower lot‐sizing costs than the Wagner‐Whitin algorithm. In addition, cost modifications are introduced which greatly enhance the multi‐level performance of these single‐level lot‐sizing heuristics.
Learning curves and lot sizing for independent and dependent demand
Authors: Kopcso David P. , Nemitz William C. 
Published: October 2002

AbstractThis paper explores the effect of learning curve cost behavior, as opposed to linear, on lot sizing. The first portion of the paper develops optimizing models for the independent demand situation. The second portion examines lot sizing for dependent demand, developing a lot sizing rule similar to Part Period Balancing.After examining the shortcomings of previous attempts at the independent demand lot sizing problem, two models are derived. Excluding material costs (for an assembly operation, the cost of all components), the optimal lot size is seen to vary linearly with demand and inversely with the carrying cost rate.When material costs are included a smaller optimal lot size is derived. The difference between the two, expressed as a fraction of the smaller lot size, equals the material/labor ratio of the last unit produced in the smaller lot size. For dependent demand, the incremental model developed by Freeland and Colley as an improvement on Part Period Balancing is used as a beginning concept. An analogous model, called Assembly Period Balancing, is developed for learning curve cost behavior. The decision rule for combining lots is expressed as a comparison of the material/labor ratio of the lot considered for combining with another expression involving the carrying cost rate, relative lot size and the learning curve exponent.Finally, cost data from an electronics manufacturer are used to examine the cost penalties of failing to recognize learning curve cost behavior. It is shown that optimal lot sizes for learning curve costs can be much larger than those obtained assuming linear costs. It is also shown that much larger lots can be economically combined in the dependent demand case when costs follow a learning curve.
Achieving factory automation through Group Technology principles
Authors: Suresh Nallan C. , Meredith Jack R. 
Published: October 2002

AbstractThis article illustrates the use of Group Technology (GT) principles for integrating the various elements of Computer Integrated Manufacturing (CIM). Several observations are made regarding the current state of batch manufacturing in the U.S. in light of these principles. Following a brief historical background, the various elements of GT are described as they occur in the manufacturing cycle. Since the main prerequisite to GT is part family identification, the various classification and coding systems for identifying part families, and also non‐codification systems, are briefly described.The benefits of design rationalization and variety reduction are then explained in the context of CAD, CAM, and CAPP. Next, cellular manufacturing, currently the major problem area in the U.S. regarding GT, is discussed. The discussion includes new production technologies and concepts such as economies of scope. Materials management and operation scheduling are discussed next, highlighting the GT/MRP interface. The effect of GT and other new technologies on quality is then addressed and the significant impacts here are noted. Next, the effects on related areas such as personnel and accounting are described, including worker satisfaction, incentive schemes, and cost tracking.Last, an assessment of the current status of batch manufacturing is undertaken. Academic approaches, as well as industry crusades such as just‐in‐time (JIT) production, are reviewed and the current problems in adopting cellular layouts are addressed.
Stochastic unpaced line design: Review and further experimental results
Authors: Smunt Timothy L. , Perkins William C. 
Published: October 2002

AbstractPrevious design studies of unpaced assembly lines that exhibit stochastic task times indicate that an unbalanced allocation of task times results in optimal output rates. In this article, we present a comprehensive review of the previous literature on this topic and discuss the results of simulation experiments that test the bowl distribution for unbalancing unpaced lines. The simulation experiment was designed to test the bowl distribution in more realistic environments than previously tested and illustrates that a balanced line configuration is as good as or better than an unbalanced line configuration when task times are modeled with more typical values of variance.Stochastic unpaced assembly line research employs both simulation and analytical approaches to test the allocation of buffer capacity and task times to work stations. Analytical models are utilized to investigate simple line designs with exponential or Erlang task time distributions. Simulation is used for longer lines and for normal task time distributions. From the review of the previous research using both approaches, we note five major findings: 1) unbalancing task time allocation is optimal when task time variation is large; 2) unbalanced allocation of buffer storage capacity improves line output rate when task time variation is large; 3) output rate of an unpaced line decreases as the number of sequential workstations increases; 4) output rate increases as more buffer storage capacity is available; and 5) output rate decreases as the task time variation increases.Most of the previous research on unpaced lines investigated lines with few workstations and large task time variation. Empirical research by Dudley (6) suggests that variation of task times in practice is much less than variations employed in previous unpaced line studies. We present the results from simulation experiments that model longer unpaced lines with lower levels of task time variance of the magnitude that is likely to occur in practice.The results of our simulation experiments verify the benefits of using the bowl distribution for task time allocation when line lengths are short and task times experience large variance. However, when line lengths are extended or task time variation is reduced, the use of the bowl distribution for unbalancing the line degrades the line's efficiency. In these situations, the optimal task time allocation is a balanced line.Two important implications for managers follow from the results of our experiments: 1) that unpaced line output rate is relatively insensitive to moderate variations from optimal task time allocations when buffer storage is limited; and 2) that perfectly balanced line designs are optimal for most cases in practice.
Maintenance management: Keeping up with production's changing trends and technologies
Authors: Gilbert James P , Finch Byron J 
Published: October 2002

AbstractCurrent trends in manufacturing have led to reduced levels of work‐in‐process inventory and increased levels of automation and machine complexity. These changes have two important implications for maintenance management. First, machine breakdowns not only cause a loss of output from the down machine, but also result in lost production on downstream machines. This occurs because of the elimination of buffer stock between workstations. Second, the gap between the technological expertise of the operators and the technological sophistication of their machines has widened. This gap decreases the ability of operators to make adjustments and minor repairs to their own machines.These two factors cause an increase in maintenance costs associated with machine downtime and maintenance labor. Historically, the proportion of preventive and corrective maintenance has attempted to balance these costs. As buffer stock is reduced and more machines are coupled, the costs of downtime will increase, increasing the need for preventive maintenance and decreasing its cost compared to the cost of lost production.Increases in the use of computer‐based planning systems have resulted in the development of computerized preventive maintenance systems that have proven to be successful in planning for maintenance labor and materials. Integrating planning methods with corrective maintenance tasks will help reduce breakdowns, make more efficient use of maintenance craft labor, and provide information for inventory control of maintenance, repair, and operating (MRO) materials.This article examines methods of reducing machine downtime costs, maintenance labor costs, and MRO inventory costs in today's changing production environment. Techniques for reducing these costs are explored in the areas of maintenance planning, maintenance methods improvement, and MRO inventory control.