bluuebunny/crossref_metadata_2025 huggingface dataset:
Retinoic Acid Metabolism and Signaling Pathways in the Adult and Developing Mouse Testis
Authors: Vernet Nadège , Dennefeld Christine , Rochette-Egly Cécile , Oulad-Abdelghani Mustapha , Chambon Pierre , Ghyselinck Norbert B. , Mark Manuel
Published: October 2005

As a first step in investigating the role of retinoic acid (RA) in mouse testis, we analyzed the distribution pattern of the enzymes involved in vitamin A storage (lecithin:retinol acyltransferase), RA synthesis (β-carotene 15,15′-monoxygenase and retinaldehyde dehydrogenases) and RA degradation (cytochrome P450 hydroxylases) as well as those of all isotypes of receptors transducing the RA signal [RA receptors (RARs) and rexinoid receptors (RXRs)]. Our data indicate that in adult testis 1) cytochrome P450 hydroxylase enzymes may generate in peritubular myoid cells a catabolic barrier that prevents circulating RA and RA synthesized by Leydig cells to enter the seminiferous epithelium; 2) the compartmentalization of RA synthesis within this epithelium may modulate, through paracrine mechanisms, the coupling between spermatogonia proliferation and spermatogenesis; 3) retinyl esters synthesized in round spermatids by lecithin:retinol acyltransferase may be transferred and stored in Sertoli cells, in the form of adipose differentiation-related protein-coated lipid droplets. We also show that RARα and RXRβ are confined to Sertoli cells, whereas RARγ is expressed in spermatogonia and RARβ, RXRα, and RXRγ are colocalized in step 7–8 spermatids. Correlating these expression patterns with the pathological phenotypes generated in response to RAR and RXR mutations and to postnatal vitamin A deficiency suggests that spermiation requires RXRβ/RARα heterodimers in Sertoli cells, whereas spermatogonia proliferation involves, independently of RXR, two distinct RAR-mediated signaling pathways in both Sertoli cells and spermatogonia. Our data also suggest that the involvement of RA in testis development starts when primary spermatogonia first appear.
Corticotropin-Releasing Hormone Directly Stimulates Thermogenesis in Skeletal Muscle Possibly through Substrate Cycling between de Novo Lipogenesis and Lipid Oxidation
Authors: Solinas G. , Summermatter S. , Mainieri D. , Gubler M. , Montani J. P. , Seydoux J. , Smith S. R. , Dulloo A. G.
Published: October 2005

The mechanisms by which CRH and related peptides (i.e. the CRH/urocortin system) exert their control over thermogenesis and weight regulation have until now focused only upon their effects on brain centers controlling sympathetic outflow. Using a method that involves repeated oxygen uptake determinations in intact mouse skeletal muscle, we report here that CRH can act directly on skeletal muscle to stimulate thermogenesis, an effect that is more pronounced in oxidative than in glycolytic muscles and that can be inhibited by a selective CRH-R2 antagonist or blunted by a nonselective CRH receptor antagonist. This thermogenic effect of CRH can also be blocked by interference along pathways of de novo lipogenesis and lipid oxidation, as well as by inhibitors of phosphatidylinositol 3-kinase or AMP-activated protein kinase. Taken together, these studies demonstrate that CRH can directly stimulate thermogenesis in skeletal muscle, and in addition raise the possibility that this thermogenic effect, which requires both phosphatidylinositol 3-kinase and AMP-activated protein kinase signaling, might occur via substrate cycling between de novo lipogenesis and lipid oxidation. The effect of CRH in directly stimulating thermogenesis in skeletal muscle underscores a potentially important peripheral role for the CRH/urocortin system in the control of thermogenesis in this tissue, in its protection against excessive intramyocellular lipid storage, and hence against skeletal muscle lipotoxicity and insulin resistance.
Characterization of crosslinking effects on the physicochemical and drug diffusional properties of cationic hydrogels designed as bioactive urological biomaterials
Authors: Jones David S , Andrews Gavin P , Gorman Sean P
Published: October 2005

This study examined the effects of concentration and type of crosslinker (tetraethyleneglycol diacrylate, TEGDA; diethyleneglycol dimethacrylate, DEGDMA; and polyethyleneglycol dimethacrylate, PEGDMA) on the mechanical and drug diffusional properties of hydrogels that had been selected as candidate coatings for bioactive medical devices. Hydrogels (dimethylaminoethylmethacrylate-covinylpyrrolidone; 1:1) were prepared by free radical polymerization and characterized using tensile analysis, dynamic contact angle analysis and analysis of swelling at pH 6.0. The release of fusidic acid and chlorhexidine was evaluated using buffered medium at pH 6.0 and, in addition, using dissolution medium that had been buffered to pH 9 in the presence and absence of elevated concentrations of calcium, representative of urinary encrustation. Crosslinker concentration, but not type, affected the advancing and receding contact angles. Conversely, both crosslinker type and concentration affected the mechanical and swelling properties of the hydrogels. Maximum swelling and elongation at break were associated with the PEGDMA-crosslinked hydrogels whereas TEGDA-crosslinked hydrogels exhibited the maximum ultimate tensile strength and Young's modulus. Drug release from all systems occurred by diffusion. The mass of chlorhexidine and fusidic acid released was dependent on crosslinker type and concentration, with hydrogels crosslinked with PEGDMA offering the greatest mass of drug released at each sampling period. The mass of fusidic acid but not chlorhexidine released at pH 9.0 in a calcium augmented medium was lower than that released in the same medium devoid of elevated calcium, due to the formation of the poorly soluble calcium salt. In conclusion, this study has uniquely examined the effects of crosslinker type and concentration on physicochemical and drug release properties essential to the clinical and non-clinical performance of bioactive hydrogels for medical device application.
Differential molecular interactions between the crystalline and the amorphous phases of celecoxib
Authors: Gupta Piyush , Bansal Arvind K , Thilagavathi R , Chakraborti Asit K
Published: October 2005

We have investigated the differences in molecular interactions between the crystalline (ordered) and amorphous (disordered) phase of a poorly soluble drug, celecoxib. Molecular interactions in the crystalline phase were investigated with the help of Mercury software, using single crystal X-ray diffracto-metric data for celecoxib. A simulated annealing molecular dynamics approach was used for the assessment of altered molecular interactions in the amorphous phase. Crystalline celecoxib was found to contain an ordered network of H-bonding between all its electron donors (-S=O group, 2-N of pyrazole ring and -C-F) and the acceptor (-N-H). Amorphous celecoxib retained all these interactions in its disordered molecular arrangement, with a relatively stronger H-bonding between the interacting groups, as compared with crystalline celecoxib. However, these inter-molecular interactions differed in strength in the two solid-state forms. The altered configurations of the molecular arrangement in the two phases were supported by the shifts observed in the Fourier-transform infra-red vibrational spectra of respective states. These interactions could have strong implications on devitrification kinetics of amorphous celecoxib, and could further guide the choice of stabilizers for the amorphous form.
In-vitro cytotoxicity, in-vivo biodistribution and anti-tumour effect of PEGylated liposomal topotecan
Authors: Hao Yan-Li , Deng Ying-Jie , Chen Yan , Hao Ai-Jun , Zhang Yong , Wang Ke-Zhan
Published: October 2005

In attempt to increase the accumulation of topotecan in tumours and improve its anti-cancer activity, PEGylated liposome (H-PEG) containing topotecan was prepared. The in-vitro cytotoxicity, in-vivo biodistribution pattern and anti-tumour effect of H-PEG were studied systemically. Compared with free topotecan or conventional liposome (H-Lip), H-PEG improved the cytotoxic effect of topotecan against human ovarian carcinoma A2780 and human colon carcinoma HCT-8 cells. The IC50 value (concentration leading to 50% cell-killing) of H-PEG decreased 5 fold (P<0.01) and 9 fold (P<0.01) against A2780 and HCT-8 cells compared with H-Lip, respectively. The results of biodistribution studies in sarcoma S180 tumour-bearing mice showed that liposomal encapsulation increased the concentration of total topotecan and the ratio of lactone form in plasma. H-PEG resulted in a 70-fold and 3.7-fold increase in AUC0→24h compared with free topotecan and H-Lip, respectively. Moreover, H-PEG increased the accumulation of topotecan in tumours and the relative tumour uptake ratio compared with free topotecan was 5.2, and higher than that of H-Lip. The anti-cancer effect studies in murine heptocarcinoma H22 tumour-bearing mice showed that H-PEG improved the therapeutic efficiency of topotecan and decreased the toxicity of topotecan to a certain extent compared with H-Lip. These results indicated that PEG-modified liposome might be an efficient carrier of topotecan.
The modulus of elasticity of fibrillin-containing elastic fibres in the mesoglea of the hydromedusaPolyorchis penicillatus
Authors: Megill William M. , Gosline John M. , Blake Robert W.
Published: October 2005

Hydromedusan jellyfish swim by rhythmic pulsation of their mesogleal bells. A single swimming muscle contracts to create thrust by ejecting water from the subumbrellar cavity. At the end of the contraction, energy stored in the deformation of the mesogleal bell powers the refilling stage, during which water is sucked back into the subumbrellar cavity. The mesoglea is a mucopolysaccharide gel reinforced with radially oriented fibres made primarily of a protein homologous to mammalian fibrillin. Most of the energy required to power the refill stroke is thought to be stored by stretching these fibres. The elastic modulus of similar fibrillin-rich fibres has been measured in other systems and found to be in the range of 0.2 to 1.1 MPa. In this paper,we measured the diameters of the fibres, their density throughout the bell,and the mechanical behaviour of the mesoglea, both in isolated samples and in an intact bell preparation. Using this information, we calculated the stiffness of the fibres of the hydromedusa Polyorchis penicillatus,which we found to be approximately 0.9 MPa, similar in magnitude to other species. This value is two orders of magnitude more compliant than the stiffness of the component fibrillin microfibrils previously reported. We show that the structure of the radial fibres can be modelled as a parallel fibre-reinforced composite and reconcile the stiffness difference by reinterpreting the previously reported data. We separate the contributions to the bell elasticity of the fibres and mesogleal matrix and calculate the energy storage capacity of the fibres using the calculated value of their stiffness and measured densities and diameters. We conclude that there is enough energy potential in the fibres alone to account for the energy required to refill the subumbrellar cavity.
Functional and structural optimization of the respiratory system of the batTadarida brasiliensis(Chiroptera, Molossidae): does airway geometry matter?
Authors: Canals Mauricio , Atala Cristian , Olivares Ricardo , Guajardo Francisco , Figueroa Daniela P. , Sabat Pablo , Rosenmann Mario
Published: October 2005

We studied structure and function of the respiratory system in the bat Tadarida brasiliensis and compared it with those of two species of rodents, Abrothrix andinus and A. olivaceus. Tadarida brasiliensis had lower resting oxygen consumption, but higher maximum oxygen consumption and aerobic scope, than the rodents. The blood–gas barrier of the bat was thinner and its relative lung size was larger; however,alveolar surface density was similar among the three species. In consequence, T. brasiliensis has an oxygen diffusion capacity two or three times higher than that of the rodents. In Tadarida brasiliensis the characteristics of the lung were accompanied by geometrical changes in the proximal airway, such as high physical optimization as a consequence of small variations in the symmetry and the scaling ratio of the bronchial diameters. These may constitute an efficient way to save energy in respiratory mechanics and are the first report of airway adjustments to decrease entropy generation in bats.
Chloride turnover and ion-transporting activities of yolk-sac preparations (yolk balls) separated from Mozambique tilapia embryos and incubated in freshwater and seawater
Authors: Hiroi Junya , Miyazaki Hiroaki , Katoh Fumi , Ohtani-Kaneko Ritsuko , Kaneko Toyoji
Published: October 2005

We have recently established a unique in vitro experimental model for mitochondrion-rich cell (MRC) research, a `yolk-ball' incubation system,in which the yolk sac is separated from the embryonic body of Mozambique tilapia embryos and subjected to in vitro incubation. To evaluate the ion-transporting property of the yolk balls, we examined Cl–content and turnover in yolk balls incubated in freshwater and seawater for 48 h, and distribution patterns of three ion transporters,Na+/K+-ATPase,Na+/K+/2Cl– cotransporter (NKCC) and cystic fibrosis transmembrane conductance regulator (CFTR), in MRCs in the yolk-sac membrane. The Cl– turnover rate measured by whole-body influx of 36Cl– was about 60 times higher in yolk balls in seawater than in freshwater, while there was no essential difference in Cl– content between them. Na+/K+-ATPase-immunoreactive MRCs were larger in yolk balls from seawater than yolk balls from freshwater. Distribution patterns of ion-transporting proteins allowed us to classify MRCs in freshwater yolk balls into three types: cells showing only basolateral Na+/K+-ATPase, cells showing basolateral Na+/K+-ATPase and apical NKCC, and cells showing basolateral Na+/K+-ATPase and basolateral NKCC. The seawater yolk balls, on the other hand, were characterized by the appearance of MRCs possessing basolateral Na+/K+-ATPase,basolateral NKCC and apical CFTR. Those seawater-type MRCs were considered to secrete Cl– through the CFTR-positive apical opening to cope with diffusional Cl– influx. These findings indicate that the yolk balls preserve the Cl– transporting property of intact embryos, ensuring the propriety of the yolk ball as an in vitroexperimental model for the yolk-sac membrane that contains MRCs.
Differential freshwater adaptation in juvenile sea-bassDicentrarchus labrax: involvement of gills and urinary system
Authors: Nebel Catherine , Romestand Bernard , Nègre-Sadargues Geneviève , Grousset Evelyse , Aujoulat Fabien , Bacal Julien , Bonhomme François , Charmantier Guy
Published: October 2005

The effects of long-term freshwater acclimatization were investigated in juvenile sea-bass Dicentrarchus labrax to determine whether all sea-bass juveniles are able to live in freshwater and to investigate the physiological basis of a successful adaptation to freshwater. This study particularly focused on the ability of sea-bass to maintain their hydromineral balance in freshwater and on their ion (re)absorbing abilities through the gills and kidneys. Two different responses were recorded after a long-term freshwater acclimatization. (1) Successfully adapted sea-bass displayed standard behavior; their blood osmolality was maintained almost constant after the freshwater challenge, attesting to their efficient hyperosmoregulation. Their branchial and renal Na+/K+-ATPase abundance and activity were high compared to seawater fish due to a high number of branchial ionocytes and to the involvement of the urinary system in active ion reabsorption, producing hypotonic urine. (2) Sea-bass that had not successfully adapted to freshwater were recognized by abnormal schooling behavior. Their blood osmolality was low (30% lower than in the successfully adapted sea-bass), which is a sign of acute osmoregulatory failure. High branchial Na+/K+-ATPase abundance and activity compared to successfully adapted fish were coupled to a proliferation of gill chloride cells, whose ultrastructure did not display pathological signs. The large surface used by the gill chloride cells might negatively interfere with respiratory gas exchanges. In their urinary system, enzyme abundance and activity were low, in accordance with the observed lower density of the kidney tubules. Urine was isotonic to blood in unsuccessfully adapted fish, ruling out any participation of the kidney in hyperosmoregulation. The kidney failure seems to generate a compensatory ion absorption through increased gill activity, but net ion loss through urine seems higher than ion absorption by the gills, leading to lower hyper-osmoregulatory performance and to death.
Active valvetrain for homogeneous charge compression ignition
Authors: Milovanovic N , Turner J G W , Kenchington S A , Pitcher G , Blundell D W
Published: October 2005

Homogeneous charge compression ignition (HCCI), also known as controlled autoignition (CAI) or the premixed charge compression ignition (PCCI) engine concept, has the potential to be highly efficient and to produce low NOx, carbon dioxide, and particulate matter emissions. However, it experiences problems with cold start in a gasoline HCCI engine, running at idle and at high loads, which, together with controlling the combustion over the entire speed/load range, limits its practical application. A way to overcome these problems is to operate the engine in ‘hybrid mode’, where the engine operates in HCCI mode at low, medium, and cruising loads and can switch to or from spark ignition (SI) or diesel (CI) mode for a cold start, idle, and higher loads. Such an engine will have frequent changes in engine load and speeds and therefore frequent transitions between HCCI and SI combustion modes. The valvetrain and engine management system (EMS) have to provide a successful control of HCCI mode and a fast and smooth transition keeping all relevant engine parameters within an acceptable range. Consequently, this leads to high demands on the valvetrain and therefore a need for a very high degree of flexibility. The aim of this paper is to present the potential of a fully variable valvetrain (FVVT) system, the Lotus active valvetrain (AVT™), for controlling HCCI combustion and enabling fast and smooth mode transitions in a HCCI/SI engine fuelled with commercially available gasoline (95 RON) and in a HCCI/DI engine fuelled with diesel (50 CN) fuel.
Controlling mechanism of ignition enhancing and suppressing additives in premixed compression ignition
Authors: Yamada H , Ohtomo M , Yoshii M , Tezaki A
Published: October 2005

Controlling ignition timing in the homogeneous charge compression ignition (HCCI) of dimethyl ether (DME) by adding methanol and ozone has been studied in a motored engine. In the standard pressure profile analysis, reduction of the first stage (cool ignition) heat release with methanol addition and consequent retardation of the second stage (hot ignition) was confirmed. Composition analysis, conducted under moderate, single cool ignition conditions, exhibited liner reductions of fuel consumption and formaldehyde formation. These observations were well reproduced by the detailed chemical kinetic model of Curran et al. for DME. A simple formulation accounting for the retarding effect was established. In contrast, acceleration with ozone addition is caused by the increase of heat release in the cool ignition taking place at a lower temperature. The cool ignition composition analysis showed increases of fuel consumption that are remarkable in lower equivalence ratio. Inclusions of ozone decomposition forming O + O2 into the model enabled good reproduction of these features. It was inferred that the early radical supply from ozone reduced the cool ignition onset temperature significantly, where a stable intermediate accumulates owing to slow decomposition, and that the resultant reduction of formaldehyde formation induced the longer chain duration.
Mixture formation and controlled auto-ignition combustion in four-stroke gasoline engines with port and direct fuel injections
Authors: Cao L , Zhao H , Jiang X , Kalian N
Published: October 2005

Controlled auto-ignition (CAI) combustion, also known as homogeneous charge compression ignition (HCCI) can be achieved by trapping residuals with early exhaust valve closure in both port and direct fuel injection four-stroke gasoline engines. A multi-cycle three-dimensional engine simulation program has been developed and applied to study the effect of injection on in-cylinder mixing and CAI combustion. The full engine cycle simulation, including complete gas exchange and combustion processes, was carried out over several cycles in order to obtain the stable cycle for analysis. The combustion models used in the present study are based on the Shell auto-ignition model and the characteristic-time combustion model, both of which have been modified to take the high level of residual gas into consideration. A liquid sheet break-up spray model was used for the droplet break-up processes. The analyses show that the injection timing plays an important role in affecting the in-cylinder air/fuel mixing and mixture temperature, which in turn affects the CAI combustion and engine performance. In comparison with the port fuel injection case, an early direct injection at exhaust valve closure can lead to higher load and lower fuel consumption.
Quality of medical care during and shortly after acute care restructuring in Newfoundland and Labrador
Authors: Curtis Bryan , Gregory Deborah , Parfrey Patrick , Kent Gloria , Jelinski Susan , Kraft Scott , O'reilly Daria , Barrett Brendan
Published: October 2005

Objectives

To critically evaluate the quality of hospital medical care at the beginning, during and shortly after regionalization of health boards in Newfoundland and Labrador, and aggregation of hospitals in the StJohn's region.

Methods

Retrospective chart audits for the years 1995/96, 1998/99 and 2000/01 (at the beginning, during and after restructuring) focused on outcomes in cardiology, respiratory medicine, neurology, nephrology, psychiatry, surgery andwomen's health programmes. Where possible, quality of care was judged on measurable outcomes in relation to published statements of likely optimal care. Comparisons were made over time within the StJohn's region, and separately for hospitals in the rest of the province.

Results

There was improvement in the use of thrombolytics and secondary measures post-myocardial infarction in both regions. Mortality and appropriateness of initial antibiotic choice for community-acquired pneumonia remained stable in both regions, with an improvement in admission appropriateness based on the severity in St John's. Aspects of stroke management (referral and time to see allied health professionals, imaging and discharge home) improved in both regions, while mortality remained stable. There was improvement in fistula rate, quality of dialysis and anaemia management in haemodialysis patients, and improvement in the peritoneal dialysis patient peritonitis rate. Readmission rate for schizophrenia remained unchanged. Stable mortality rates were observed for frequently performed surgical procedures. The post-coronaryartery by pass grafting (CABG) morbid event rate improved, although access to CABG was not optimal.

Conclusions

Aggregation of acute care hospitals was feasible without attendant deterioration in patient care, and in some areas care improved. However, access to services continued to be a major problem in all regions.
Regionalization of health services in Newfoundland and Labrador: perceptions of the planning, implementation and consequences of regional governance
Authors: Neville Doreen , Barrowman Gwynedd , Fitzgerald Brenda , Tomblin Stephen
Published: October 2005

Objectives

To describe the context and key drivers for regionalization of one provincial health care system in Canada; to document the original expectations of regionalization on governance and the extent to which these expectations were met; to identify the perceived successes and weaknesses of the process; and to examine the key issues and concerns that warrant further consideration and action in the future.

Methods

Forty-five CEO/senior administrator or senior health department officials in the period 1993-2001 were invited to participate, of whom 35 were interviewed (67% of senior health officials and 85% of CEOs/ senior administrators).

Results

For the most part, key informants felt that expectations of reform with respect to reduction in the number of boards and integration of services under each board's mandate did occur. However, ongoing financial restraint, failure to include the full range of health services under the regional board mandate (including physician and pharmaceutical services), uncertainty regarding the level of authority the regional boards had for decision-making, and unclear accountability mechanisms between the regional boards and the provincial Ministry of Health limited the extent to which broader expectations related to development of a population health focus, and improved continuity of care for individuals and families was achieved.

Conclusions

Implications for policy-makers were identified in four main areas: alignment between health policy goals and the governance structure; clarification of authority and accountability relationships; clarification of roles and responsibilities among all key actors; and strengthening of mechanisms that support accountability.
Book Reviews
Authors: Lev Benjamin
Published: October 2005

The range of books reviewed is wide, covering theory and applications in operations research, statistics, management science, econometrics, mathematics, computers, and information systems (no software is reviewed). In addition, we include books in other fields that emphasize technical applications. Publishers who wish to have their books reviewed should send them to Professor Benjamin Lev. We list the books received; not all books received can be reviewed because space is limited. Those who would like to review books are urged to send me their names, addresses, and specific areas of expertise. We commission all reviews and do not accept unsolicited book reviews. Readers are encouraged to suggest books that might be reviewed or to ask publishers to send me copies of such books.

The authors or editors of the books reviewed in this issue are Navneet Bhushan, Kanwal Rai, Harold R. Booher, H. A. Eiselt, C.-L. Sandblom, Jatinder N. D. Gupta, Sushil K. Sharma, Joao Jose, and Pinto Ferreira.
Hewlett-Packard Combined OR and Expert Knowledge to Design Its Supply Chains
Authors: Laval Claude , Feyhl Marc , Kakouros Steve
Published: October 2005

Although one can eliminate human bias from scenario definitions when modeling supply chain networks by using a pure operations research approach, the resources, data, and time needed for this approach may prohibit its use in fast-paced business environments. Hewlett-Packard’s (HP’s) strategic planning and modeling (SPaM) team refined an approach using true optimization coupled with scenario analysis, selectively focused on the most critical parameters of the design equation, and used this approach to solve a complex supply chain design problem for HP’s imaging and printing group. The clear and easily demonstrable results helped management to understand their derivation and act confidently. The combined approach gave equal emphasis to optimization and to scenario analysis.
Is Out of Sight, Out of Mind? An Empirical Study of Social Loafing in Technology-Supported Groups
Authors: Chidambaram Laku , Tung Lai Lai
Published: October 2005

Research on group behavior has identified social loafing, i.e., the tendency of members to do less than their potential, as a particularly serious problem plaguing groups. Social Impact Theory (SIT) helps explain social loafing in terms of two theoretical dimensions—the dilution effect (where an individual feels submerged in the group) and the immediacy gap (where an individual feels isolated from the group). In this study, which employed a controlled experiment, we investigated these dimensions of social loafing in the context of group decision making, using collocated and distributed teams of varying sizes. Our results—in line with SIT—indicate that small groups, signifying a small dilution effect, had increased individual contributions and better group outcomes compared to their larger counterparts. However, support for SIT's arguments about the immediacy gap was mixed: Members contributed visibly more when they were collocated, but no significant differences in group outcomes were evident. Regardless of dimension, the quality of the input (ideas generated) determined the quality of the output (decisions made). Also, contrary to the literature on brainstorming, having more ideas to work with resulted in poorer-quality decisions. This apparent paradox is explained using the notion of integrative complexity, which challenges conventional wisdom regarding the relationship between individual inputs and group outputs. The implications of these results for practice and research are examined.
Imprecise DEA via Standard Linear DEA Models with a Revisit to a Korean Mobile Telecommunication Company
Authors: Zhu Joe
Published: October 2005

Data Envelopment Analysis (DEA) requires that the data for all inputs and outputs are known exactly. When some outputs and inputs are unknown decision variables, such as bounded and ordinal data, the DEA model becomes a nonlinear programming problem and is called imprecise DEA (IDEA). The nonlinear IDEA program can be converted into a linear program by an algorithm based upon scale transformations and variable alterations. Such an algorithm requires a set of special computational codes for each evaluation, because a different objective function and a different constraint with a set of new variables are present for each unit under evaluation. The current paper revisits a published Korean telecommunication analysis, and, by so doing, presents a new and simple approach to execute the IDEA through the standard linear DEA models. This greatly enhances the applicability of IDEA in applications, and the IDEA analysis is no longer limited to obtaining the efficiency scores. The key to the new approach lies in the finding that imprecise data can be easily converted into exact data. Based upon the exact data, models can be developed to determine all possible multiple optimal solutions in imprecise data, and to perform efficiency sensitivity analysis in IDEA.
Production Control in the Face of Storable Raw Material, Random Supply, and an Outside Market
Authors: Yang Jian
Published: October 2005

We study a periodic-review production/inventory control problem where both the supply of raw material and demand for the finished product are exogenous and random, the raw material can be stored for future use, can be purchased from or sold to an outside market. We study both the lost sales and backlogging cases under both strict convex and linear raw material purchasing/selling costs. Convexity of the purchasing/selling cost implies that the more the firm purchases from or sells to the outside market, the more expensive or less valuable the raw material becomes. For all cases, we find the partial characterizations for the optimal policies, which all turn out to be very intuitively appealing. In particular, for each of the linear-cost cases, the optimal policy degenerates into a combination of two base-stock policies: one for the raw material inventory and the other for the finished product inventory.
Scheduling Problems with Two Competing Agents
Authors: Agnetis Allesandro , Mirchandani Pitu B. , Pacciarelli Dario , Pacifici Andrea
Published: October 2005

We consider the scheduling problems arising when two agents, each with a set of nonpreemptive jobs, compete to perform their respective jobs on a common processing resource. Each agent wants to minimize a certain objective function, which depends on the completion times of its jobs only. The objective functions we consider in this paper are maximum of regular functions (associated with each job), number of late jobs, and total weighted completion times. We obtain different scenarios, depending on the objective function of each agent, and on the structure of the processing system (single machine or shop). For each scenario, we address the complexity of various problems, namely, finding the optimal solution for one agent with a constraint on the other agent's cost function, finding single nondominated schedules (i.e., such that a better schedule for one of the two agents necessarily results in a worse schedule for the other agent), and generating all nondominated schedules.
Bioinformatics and Management Science: Some Common Tools and Techniques
Authors: Abbas Ali E. , Holmes Susan P.
Published: October 2005

In April of 2003, Science (2003) and Nature (2003) published special issues marking two significant achievements in the history of science: the 50th anniversary of discovering the double helical structure of the DNA, and the completion of the Human Genome Project. The first discovery led to a new age in genetics, and the second event marked the beginning of a new era that uses the genome in medicine. The international efforts to determine the human DNA sequence and assess its ethical, legal, and social implications started in 1990. Since then, the data from the project has been available in public databases for researchers and scientists around the world. The vast increase in biological data led to increasing interest in computational biology and an emerging multidisciplinary research area known as bioinformatics. Most people working in this area have mathematics, biology, biochemistry, or computer science backgrounds and have learned about the field by using tools from another discipline to answer questions in biology. The current challenge is to utilize the genome data to its full extent and to develop tools that improve our understanding of biological pathways and accelerate drug discovery. Many of the algorithms needed to solve these problems have management science and operations research aspects. This paper introduces some of the fundamental problems in bioinformatics to an operations research audience and demonstrates the application of management science tools in their formulation and solution.
Nested Partitions Method for Global Optimization
Authors: Shi Leyuan , Ólafsson Sigurdur
Published: October 2005

We propose a new randomized method for solving global optimization problems. This method, the Nested Partitions (NP) method, systematically partitions the feasible region and concentrates the search in regions that are the most promising. The most promising region is selected in each iteration based on information obtained from random sampling of the entire feasible region and local search. The method hence combines global and local search. We first develop the method for discrete problems and then show that the method can be extended to continuous global optimization. The method is shown to converge with probability one to a global optimum in finite time. In addition, we provide bounds on the expected number of iterations required for convergence, and we suggest two stopping criteria. Numerical examples are also presented to demonstrate the effectiveness of the method.
Adjustment Strategies for a Fixed Delivery Contract
Authors: Moinzadeh Kamran , Nahmias Steven
Published: October 2005

We consider a long term contractual agreement between buyer and seller in which Q units are delivered to the buyer at regular time intervals. It must be true that the delivery quantity, Q, is less than the mean demand per period. In order to manage the inventory, the buyer has the option of adjusting the delivery quantity upwards just prior to a delivery, but must pay a premium to do so. Demand is assumed random, and we model the system in a continuous review setting. We show that the equations one must solve to find optimal adjustment strategies are intractable. A diffusion approximation is developed which when coupled with the solution to an even simpler deterministic version of the problem yields very simple but effective approximations. Extensive computations are included to compare the performance of the optimal and approximate policies. We also empirically derive a formula for computing Q whose accuracy is established computationally. We prove that the fixed delivery contract results in lower variance of orders to the seller. We also include a computational study to find the unit cost discount that equalizes the expected costs for the fixed delivery contract and the base stock contract for a large parameter set.
Marketable Pollution Permits in Oligopolistic Markets with Transaction Costs
Authors: Nagurney Anna , Dhanda Kanwalroop Kathy
Published: October 2005

In this paper, we present a variational inequality framework for the modeling, qualitative analysis, and computation of equilibrium patterns in multiproduct, multipollutant oligopolistic markets with marketable pollution permits in the presence of transaction costs. The model deals explicitly with spatial differentiation and also guarantees that the imposed environmental quality standards are met through the initial allocation of licenses. An algorithm is proposed, with convergence results, to compute the profit-maximized quantities of the oligopolistic firms' products and the quantities of emissions, along with the equilibrium allocation of licenses and their prices. Numerical examples are included to illustrate this approach.
Scheduling of Multi-Class Single-Server Queues Under Nontraditional Performance Measures
Authors: Ayhan Hayriye , Olsen Tava Lennon
Published: October 2005

We consider a multi-class production system without setups where many job classes share a single server. The traditional performance measure used for scheduling these systems is that of mean throughput time (i.e., the time spent in the system). However, mean throughput time may not be the only measure of importance in real systems. In particular, throughput time variance and the outer percentiles of throughput time may be equally important. We present two heuristics for scheduling multi-class single-server queues that are based on heavy-traffic analysis and perform well with respect to these nontraditional measures in a wide variety of cases. An approximation is given for the throughput time distribution under both scheduling methods.
The Multistage Service Facility Start-Up and Capacity Model
Authors: Li Lode , Zhang Hongtao
Published: October 2005

In service industries, operations are often split into the “front office” and the “back room.” The front office deals directly with customers, whereas the back room engages in manufacturing-like operations. While such an arrangement may enjoy many benefits including reduced customer participation and back room efficiency, it gives rise to the possibility of communication and coordination problems between the front office and the back room. To address such coordination problems, we work from one popular piece of case material in operations management, the National Cranberry Cooperative (NCC) case, and develop and analyze a service facility start-up and capacity model based on a finite-horizon, multistage queueing system. The model allows for general variability that can be either stationary or nonstationary, predictable or unpredictable. We derive the relationships between job start and finish times and primitive parameters and control variables using a sample path construction. We then show that two performance measures, the expected waiting and operating costs, have desirable convexity properties with respect to the control variables; namely, the starting time and the processing capacity of each stage. We also show how to perform marginal analysis on start-up times. Numerical examples based on the NCC case are presented and discussed. The model can be extended and applied to many service and manufacturing situations.
Murder in the Criminal Law of Iran and Islam
Authors: Ghodsi Ebrahim
Published: October 2005

Wilful murder, the deliberate killing of another human being, is considered a crime in the criminal law of Iran and Islam, and the consequential penalty invoked is retaliation. The offence, as in English law, requires proof of both actus reus (external element) and mens rea (fault element). The statutory offence may be found in Articles 14 and 204–268 of the 1991 version of the Islamic Penal Code and in Articles 612–615 of 1996 Code.

In Islam there are many verses and precedents (of the Prophet and the Shiite Imams) condemning the crime of murder as illegal and retaliation as the appropriate punishment for this crime provided the legal elements are established. The requisite elements of the offence have been subjected to varied review in Iran and Islam. The focus of this article is to study the key ingredients in more depth.

Retaliation as a punishment has three key aspects: it is personal; it should be equal with the crime; and to be performed according to the will and option of the avengers of blood.
Fighting Corruption and Embezzlement in Third World Countries
Authors: Fantaye Dawit Kiros
Published: October 2005

Economic crime is one of the most serious crimes endangering the national security and public safety of any country. It is directly associated with legal, political, social, human rights and development issues. In particular, economic crime harms Third World countries such as Ethiopia where poverty is prevalent and the economy is poor and supported by foreign aid and loans. White-collar employees like higher government officials and businessmen play a key role in creating and increasing economic crimes, namely corruption, embezzlement and fraud, all over the world. It is therefore important that any form of economic crime is identified and punished severely, by appropriate prison terms according to the seriousness of the offence. By applying these kinds of penalties to economic criminals, the rate and frequency of economic crime can be minimised and, simultaneously, pave a way to the fundamental practices of democracy, government transparency and the dominance of the rule of law in the country. The main purpose of this article is to explain the effect of corruption in Third World countries and ways in which it can be combated, in particular by the imposition of heavy penalties on those who choose to commit economic crimes in Third World countries. It is argued that this must be done to protect human rights, to bring about political and social stabilisation, to ensure effective and even distribution of national wealth and, eventually, to secure democracy and sustainable development in the Third World countries.
Association of Inosine Triphosphatase 94C>A and Thiopurine S-Methyltransferase Deficiency with Adverse Events and Study Drop-Outs under Azathioprine Therapy in a Prospective Crohn Disease Study
Authors: von Ahsen Nicolas , Armstrong Victor W , Behrens Christoph , von Tirpitz Christian , Stallmach Andreas , Herfarth Hans , Stein Jürgen , Bias Peter , Adler Guido , Shipkova Maria , Oellerich Michael , Kruis Wolfgang , Reinshagen Max
Published: October 2005

Background: Azathioprine (aza) therapy is beneficial in the treatment of inflammatory bowel disease, but 10%–30% of patients cannot tolerate aza therapy because of adverse drug reactions. Thiopurine S-methyltransferase (TPMT) deficiency predisposes to myelotoxicity, but its association with other side effects is less clear. Inosine triphosphatase (ITPA) mutations are other pharmacogenetic polymorphisms possibly involved in thiopurine metabolism and tolerance.

Methods: We analyzed data from a 6-month prospective study including 71 patients with Crohn disease undergoing first-time aza treatment with respect to aza intolerance. Patients were genotyped for common TPMT and ITPA mutations and had pretherapy TPMT activity measured.

Results: Early drop-out (within 2 weeks) from aza therapy was associated with ITPA 94C>A [P = 0.020; odds ratio (OR), 4.6; 95% confidence interval (95% CI), 1.2–17.4] and low TPMT activity [<10 nmol/(mL erythrocytes · h); P = 0.007; OR = 5.5; 95% CI, 1.6–19.2]. A high-risk group defined by ITPA 94C>A or TPMT <10 nmol/(mL erythrocytes · h) showed significant association with early drop-out (P = 0.001; OR = 11.3; 95% CI, 2.5–50.0) and all drop-outs (P = 0.002; OR = 4.8; 95% CI, 1.8–13.3). For only drop-outs attributable to aza-related side effects (n = 16), there was a significant association with ITPA 94C>A (P = 0.002; OR = 7.8; 95% CI, 2.1–29.1). Time-to-event analysis over the 24-week study period revealed a significant association (P = 0.031) between the time to drop-out and ITPA 94C>A mutant allele carrier status.

Conclusions: Patients with ITPA 94C>A mutations or low TPMT activity constitute a pharmacogenetic high-risk group for drop-out from aza therapy. ITPA 94C>A appears to be a promising marker indicating predisposition to aza intolerance.
Parental Monitoring: A Process Model of Parent-Adolescent Interaction
Authors: Hayes Louise , Hudson Alan , Matthews Jan
Published: October 2005

Empirical evidence supports parental monitoring as a moderator of adolescent problem behaviours. A methodological review shows that monitoring has been measured using self-report questions based on parental knowledge of adolescent free-time use; however, inconsistencies in the definition of monitoring have created confusion. A process model of parental monitoring is proposed. This proposed model conceptualises monitoring interactions in a temporal sequence. It proposes that parental monitoring occurs in two distinct stages: before the adolescent goes out and when they return home. Parental and adolescent responses to monitoring interactions impact on future monitoring episodes. The proposed model demonstrates that a functional understanding of parent and adolescent monitoring behaviours is essential to clinical prevention and intervention.
A Universal Prevention Trial of Anxiety Symptomology during Childhood: Results at 1-Year Follow-up
Authors: Lowry-Webster Hayley M. , Barrett Paula M. , Lock Sally
Published: October 2005

In 2001 we evaluated a universal prevention trial of anxiety during childhood, and also examined the effects of the program on levels of depression. Participants were 594 children aged 10—13 years from seven schools in Brisbane, Australia, who were randomly assigned to an intervention or control group on a school-by-school basis. The intervention was based on the group CBT program FRIENDS (Barrett, Lowry-Webster & Holmes, 1999a, 1999b, 1999c). Results were examined universally (for all children) and for children who scored above the clinical cut-off for anxiety at pre-test. At 12-month follow-up, intervention gains were maintained, as measured by self-reports and diagnostic interviews. Eighty-five per cent of children in the intervention group who were scoring above the clinical cut-off for anxiety and depression were diagnosis free in the intervention condition, compared to only 31.2% of children in the control group. Implications of these findings are examined, alongside limitations and directions for future research.