bluuebunny/crossref_metadata_2025 huggingface dataset:
Delayed-shot 3D depth migration
Authors: Zhang Yu , Sun James , Notfors Carl , Gray Samuel H. , Chernis Leon , Young Jerry
Published: September 2005

For 3D seismic imaging in structurally complex areas, the use of migration by wavefield extrapolation has become widespread. By its very nature, this family of migration methods operates on data sets that satisfy a wave equation in the context of a single, physically realizable field experiment, such as a common-shot record. However, common-shot migration of data recorded over dipping structures requires a migration aperture much larger than the recording aperture, resulting in extra computations. A different type of wave-equation record, the response to a linear or planar source, can be synthesized from all the common-shot records. Synthesizing these records from common-shot records involves slant-stack processing, or applying delays to the various shots; we call these records delayed-shot records. Delayed-shot records don't suffer from the aperture problems of common-shot records since their recording aperture is the length of the seismic survey. Consequently, delayed-shot records hold potential for efficient, accurate imaging by wavefield extrapolation. We present a formulation of delayed-shot migration in 2D and 3D (linear sources) and its application to 3D marine streamer data. This formulation includes a discussion of sampling theory issues associated with the formation of delayed-shot records. For typical marine data, 2D and 3D delayed-shot migration can be significantly more efficient than common-shot migration. Synthetic and real data examples show that delayed-shot migration produces images comparable to those from common-shot migration.
Marine self-potential gradient exploration of the continental margin
Authors: Heinson Graham , White Antony , Robinson David , Fathianpour Nader
Published: September 2005

The self-potential (SP) method for mineral exploration is seldom used on land, primarily because of electrode noise problems and nonunique interpretations. Marine measurements of the horizontal gradient of the SP field, on the other hand, are relatively simple to make with an array of electrodes towed behind a ship. With low ship speeds of 5 to 10 km/hour, dense spatial sampling (∼1 m) can be obtained with resolution of better than 1 μV/m. In this paper we report on gradient SP data recorded on the continental shelf of South Australia by a horizontal array of towed electrodes approximately 20 m above the seafloor. Ocean waves and swells with periods of 5 to 15 s yielded large amplitude signals ±20 μV/m, but subseafloor mineralization produced SP gradient anomalies of ±50 μV/m and widths of 2 km or more in a number of parallel traverses. Integrating the observed SP gradients along each line delineated SP anomalies of amplitude up to −100 mV. Self-potential and magnetic anomaly data show limited spatial correlation and have different wavelengths, suggesting that SP sources are probably nonferrous minerals, such as graphite, and are deeper than the magnetic sources. The source of the SP signal is probably reduction-oxidation (redox) potential ([Formula: see text]) variations across a conducting body below the seafloor. We approximate the source as being two dimensional and find the most probable locations of line sources by an image reconstruction method. Numerical finite-element modeling of more realistic source regions suggests shallow, easterly dipping (∼15°) conductors of 1 Ω.m in the uppermost 2 km.
Combined application of surface geoelectrical methods for groundwater flow modeling: A case history
Authors: Titov Konstantin V. , Levitski Alexander , Konosavski Pavel K. , Tarasov Andrey V. , Ilyin Yuri T. , Buès Michel A.
Published: September 2005

Electrical methods [electrical profiling and sounding, induced polarization (IP), and self-potential (SP)], combined with geochemical and hydrochemical surveys, were applied to characterize shallow sediments at a site contaminated by oil-related brines. The site is located within the Romashkinskoye oil field (Tatarstan Republic, Russian Federation). Results of geochemical and hydrochemical surveys, as well as those of electrical profiling, revealed no individual haloes of contaminant in the soil and groundwater, which suggests that the entire site is contaminated. Vertical electrical IP soundings (VES-IP) allowed us to obtain the stratigraphic characteristics of the site and to distinguish a shallow aquifer among clayey aquitards. Interpretation of SP data on the basis of forward numerical modeling helped us to develop a groundwater-flow model of the site. To reduce ambiguities, we kept fixed the values of layer resistivity derived from the inverted VES-IP data. Boundary conditions on water head and water flow were based on drilling and sampling data. We varied only the values of hydraulic conductivity to fit the calculated SP values to the measured SP values. We found a strong misfit between the measured and calculated SP values for the one-aquifer model. By inferring a second, deeper-seated aquifer, we computed a two-aquifer model that produced a satisfactory SP fit.
Seismic attributes — A historical perspective
Authors: Chopra Satinder , Marfurt Kurt J.
Published: September 2005

A seismic attribute is a quantitative measure of a seismic characteristic of interest. Analysis of attributes has been integral to reflection seismic interpretation since the 1930s when geophysicists started to pick traveltimes to coherent reflections on seismic field records. There are now more than 50 distinct seismic attributes calculated from seismic data and applied to the interpretation of geologic structure, stratigraphy, and rock/pore fluid properties. The evolution of seismic attributes is closely linked to advances in computer technology. As examples, the advent of digital recording in the 1960s produced improved measurements of seismic amplitude and pointed out the correlation between hydrocarbon pore fluids and strong amplitudes (“bright spots”). The introduction of color printers in the early 1970s allowed color displays of reflection strength, frequency, phase, and interval velocity to be overlain routinely on black-and-white seismic records. Interpretation workstations in the 1980s provided interpreters with the ability to interact quickly with data to change scales and colors and to easily integrate seismic traces with other information such as well logs. Today, very powerful computer workstations capable of integrating large volumes of diverse data and calculating numerous seismic attributes are a routine tool used by seismic interpreters seeking geologic and reservoir engineering information from seismic data. In this review paper celebrating the 75th anniversary of the Society of Exploration Geophysicists, we reconstruct the key historical events that have lead to modern seismic attribute analysis.
Alteration of Transforming Growth Factor-β Signaling System Expression in Adult Rat Germ Cells with a Chronic Apoptotic Cell Death Process after Fetal Androgen Disruption
Authors: Maire Magali , Florin Anne , Kaszas Krisztian , Regnier Daniel , Contard Pierre , Tabone Eric , Mauduit Claire , Bars Remi , Benahmed Mohamed
Published: September 2005

In utero exposure to chemicals with antiandrogen activity induces undescended testis, hypospadias, and sub- or infertility. The hypospermatogenesis observed in the adult rat testis exposed in utero to the antiandrogen flutamide has been reported to be a result of a long-term apoptotic cell death process in mature germ cells. However, little if anything is known about the upstream signaling mechanisms controlling this apoptosis. In the present study, we have investigated the possibility that the TGF-β signaling pathway may be at play in this control of the apoptotic germ cell death process. By using a model of adult rat exposed in utero to 0, 0.4, 2, or 10 mg/kg·d flutamide, we observed that pro-TGF-β signaling members, such as the three isoforms of TGF-β ligands (TGF-β1–3), the two TGF-β receptors (TGF-βRI and -RII) and the R-Smads Smad 1, Smad 2, Smad 3, and Smad 5 were inhibited at the mRNA and protein levels, whereas the anti-TGF-β signaling member Smad 7 was overexpressed. Furthermore, we report that the overexpression of Smad 7 mRNA could induce an activation of c-Jun N-terminal kinase, because of the observed c-Jun overexpression, activation, and nuclear translocation leading to an increase in the transcription of the proapoptotic factor Fas-L. Together, the alterations of TGF-β signaling may represent upstream mechanisms underlying the adult germ cell apoptotic process evidenced in adult rat testis exposed in utero to antiandrogenic compounds such as flutamide.
Cutaneous water loss and lipids of the stratum corneum in house sparrowsPasser domesticusfrom arid and mesic environments
Authors: Muñoz-Garcia Agustí , Williams Joseph B.
Published: September 2005

Birds that live in hot, dry environments must balance water intake with losses in order to maintain water homeostasis. The outer layer of the integument, called the stratum corneum (SC), consists of corneocytes embedded in a matrix of lipids. The SC serves as a barrier to water vapor diffusion through the skin. We measured cutaneous water loss (CWL) in two populations of house sparrow Passer domesticus L., one living in a desert environment in Saudi Arabia, and another living in a mesic environment in Ohio, USA. We found that CWL rates at 30°C were lower in desert individuals (11.9±2.2 mg H2O cm-2day-1; N=11) than in mesic birds (16.0±2.6 mg H2O cm-2 day-1; N=14). We hypothesized that changes in the lipid composition of the SC could affect CWL. We analyzed four classes of lipids in the SC: ceramides, cerebrosides,cholesterol and free fatty acids, by thin layer chromatography. Compared to mesic sparrows, desert birds had a higher amount of ceramides(49.2±10.3 mg g-1 SC dry mass in Saudi Arabia;38.2±18.0 mg g-1 SC dry mass in Ohio) and cerebrosides(101.2±48.9 mg g-1 SC dry mass in Saudi Arabia;56.5±34.0 mg g-1 SC dry mass in Ohio), and a lower percentage of cholesterol (4.1±3.6% in Saudi Arabia; 5.4±2.5% in Ohio) in their SC.

Although CWL was lower in sparrows from Arabia, and lipid composition of their SC differed, we could not detect differences between rates of water loss through non-living skin attached to glass vials (46.0±15.7 mg H2O cm-2 day-1 for sparrows in Saudi Arabia;45.8±27.2 mg H2O cm-2 day-1 for sparrows in Ohio). These results suggest that biological control mechanisms interact with layers of lipids in the stratum corneum to adjust CWL to the environment.
Identification of sex-specific transcripts of theAnopheles gambiae doublesexgene
Authors: Scali Christina , Catteruccia Flaminia , Li Qiuxiang , Crisanti Andrea
Published: September 2005

The understanding of the molecular mechanisms of sex differentiation in the mosquito Anopheles gambiae could identify important candidate genes for inducing selective male sterility in transgenic lines or for sex-controlled expression of lethal genes. In many insects, doublesex(dsx) is the double-switch gene at the bottom of the somatic sex-determination cascade that determines the differentiation of sexually dimorphic traits. We report here on the identification of the dsxhomologue in A. gambiae and on the characterization of its sex-specific transcripts. Agdsx consists of seven exons, distributed over an 85 kb region on chromosome 2R, which are sex-specifically spliced to produce the female and male AgdsxF and AgdsxM transcripts. AgdsxF contains a 795 bp ORF, coding for a protein of 265 amino acids, while AgdsxM comprises a much longer (1866 bp) ORF, coding for a 622 aa protein. Differences in the exon/intron organization suggest that Agdsx sex-specific splicing results from a different mechanism from Drosophila melanogaster dsx. These findings represent an important step towards the understanding of sex differentiation in Anophelesand will facilitate the use of gene transfer technologies to manipulate sex ratios for vector control programs based on the sterile insect technique.
Induction of branchial ion transporter mRNA expression during acclimation to salinity change in the euryhaline crabChasmagnathus granulatus
Authors: Luquet Carlos M. , Weihrauch Dirk , Senek Mihaela , Towle David W.
Published: September 2005

Using quantitative real-time PCR, the expression of mRNAs encoding three transport-related proteins and one putative housekeeping protein was analyzed in anterior and posterior gills of the euryhaline crab Chasmagnathus granulatus following transfer from isosmotic conditions (30‰salinity) to either dilute (2‰) or concentrated (45‰) seawater. Modest changes were observed in the abundance of mRNAs encoding the housekeeping protein arginine kinase and the vacuolar-type H+-ATPase B-subunit, both of which were highly expressed under all conditions. By contrast, the expression of Na+/K+-ATPaseα-subunit mRNA and Na+/K+/2Cl-cotransporter mRNA was strongly responsive to external salinity. During acclimation to dilute seawater, cotransporter mRNA increased 10-20-fold in posterior gills within the first 24 h while Na+/K+-ATPase α-subunit mRNA increased 35-55-fold. During acclimation to concentrated seawater, cotransporter mRNA increased 60-fold by 96 h and Na+/K+-ATPase α-subunit increased approximately 25-fold in posterior gills. Our results indicate a complex pattern of transcriptional regulation dependent upon the direction of salinity change and the developmental background of the gills.
Venous tone and cardiac function in the South American rattlesnakeCrotalus durissus: mean circulatory filling pressure during adrenergic stimulation in anaesthetised and fully recovered animals
Authors: Skals Marianne , Skovgaard Nini , Abe Augusto S. , Wang Tobias
Published: September 2005

The effects of adrenergic stimulation on mean circulatory filling pressure(MCFP), central venous pressure (PCV) and stroke volume(Vs), as well as the effects of altered MCFP through changes of blood volume were investigated in rattlesnakes (Crotalus durissus). MCFP is an estimate of the upstream pressure driving blood towards the heart and is determined by blood volume and the activity of the smooth muscle cells in the veins (venous tone). MCFP can be determined as the plateau in PCV during a total occlusion of blood flow from the heart.

V s decreased significantly when MCFP was lowered by reducing blood volume in anaesthetised snakes, whereas increased MCFP through infusion of blood (up to 3 ml kg-1) only led to a small rise in Vs. Thus, it seems that end-diastolic volume is not affected by an elevated MCFP in rattlesnakes. To investigate adrenergic regulation on venous tone, adrenaline as well as phenylephrine and isoproterenol (α- and β-adrenergic agonists, respectively) were infused as bolus injections (2 and 10 μg kg-1). Adrenaline and phenylephrine caused large increases in MCFP and PCV,whereas isoproterenol decreased both parameters. This was also the case in fully recovered snakes. Therefore, adrenaline affects venous tone through bothα- and β-adrenergic receptors, but the α-adrenergic receptor dominates at the dosages used in the present study. Injection of the nitric oxide donor SNP caused a significant decrease in PCV and MCFP. Thus, nitric oxide seems to affect venous tone.
Extreme impact and cavitation forces of a biological hammer: strike forces of the peacock mantis shrimpOdontodactylus scyllarus
Authors: Patek S. N. , Caldwell R. L.
Published: September 2005

Mantis shrimp are renowned for their unusual method of breaking shells with brief, powerful strikes of their raptorial appendages. Due to the extreme speeds of these strikes underwater, cavitation occurs between their appendages and hard-shelled prey. Here we examine the magnitude and relative contribution of the impact and cavitation forces generated by the peacock mantis shrimp Odontodactylus scyllarus. We present the surprising finding that each strike generates two brief, high-amplitude force peaks, typically 390–480 μs apart. Based on high-speed imaging, force measurements and acoustic analyses, it is evident that the first force peak is caused by the limb's impact and the second force peak is due to the collapse of cavitation bubbles. Peak limb impact forces range from 400 to 1501 N and peak cavitation forces reach 504 N. Despite their small size, O. scyllarus can generate impact forces thousands of times their body weight. Furthermore, on average, cavitation peak forces are 50% of the limb's impact force, although cavitation forces may exceed the limb impact forces by up to 280%. The rapid succession of high peak forces used by mantis shrimp suggests that mantis shrimp use a potent combination of cavitation forces and extraordinarily high impact forces to fracture shells. The stomatopod's hammer is fundamentally different from typical shell-crushing mechanisms such as fish jaws and lobster claws, and may have played an important and as yet unexamined role in the evolution of shell form.
Hewlett-Packard Company Unlocks the Value Potential from Time-Sensitive Returns
Authors: Guide V. Daniel R. , Muyldermans Luc , Van Wassenhove Luk N.
Published: September 2005

Hewlett-Packard (HP) and other companies producing short life-cycle products with rapid value erosion squander the opportunity to profit from returned time-sensitive products when they treat them as a nuisance. Instead of focusing on cost minimization and technical quality, they should recognize returns as a value stream and maximize the revenue from smart and fast disposition, proper refurbishment, and prompt resale through the appropriate channels. We worked on a project with Hewlett-Packard’s remarketing group to unlock the value potential of time-sensitive returns. We analyzed data using simple calculations to reveal the major drivers and magnitude of potential value recovery, and we used simple operations research flow models to evaluate new design and policy options for the reverse supply chain. HP benefited from an integrated end-to-end business approach to product returns.
ASP, The Art and Science of Practice: Elements of a Theory of the Practice of Operations Research: Expertise in Practice
Authors: Murphy Frederic H.
Published: September 2005

This is the second paper in a series of three (Murphy 2005a, b) on the practice of operations research. In the first paper I described an overall framework for a theory of practice and discussed the potential of cognitive science as an organizing framework of the knowledge and skills that make for good practice. Expertise in the context of OR practice consists of technical knowledge, institutional knowledge, and procedures and heuristics for bringing that knowledge to bear on the problem at hand and organizational issues. I illustrate technical expertise and heuristics using linear programming modeling and infeasibility analysis. Soft-OR techniques are useful for developing an understanding of the more complex and ill-formed issues an organization faces.
Model World: The Great Debate—MAUT Versus AHP
Authors: Gass Saul I.
Published: September 2005

The analytic hierarchy process has gained wide acceptance among academics and practitioners.
System-Optimal Routing of Traffic Flows with User Constraints in Networks with Congestion
Authors: Jahn Olaf , Möhring Rolf H. , Schulz Andreas S. , Stier-Moses Nicolás E.
Published: September 2005

The design of route guidance systems faces a well-known dilemma. The approach that theoretically yields the system-optimal traffic pattern may discriminate against some users in favor of others. Proposed alternate models, however, do not directly address the system perspective and may result in inferior performance. We propose a novel model and corresponding algorithms to resolve this dilemma. We present computational results on real-world instances and compare the new approach with the well-established traffic assignment model. The essence of this study is that system-optimal routing of traffic flow with explicit integration of user constraints leads to a better performance than the user equilibrium, while simultaneously guaranteeing superior fairness compared to the pure system optimum.
Rendezvous-Evasion Search in Two Boxes
Authors: Gal S. , Howard J. V.
Published: September 2005

An agent (who may or may not want to be found) is located in one of two boxes. At time 0 suppose that he is in box B. With probability p he wishes to be found, in which case he has been asked to stay in box B. With probability 1−p he tries to evade the searcher, in which case he may move between boxes A and B. The searcher looks into one of the boxes at times 1, 2, 3, … . Between each search the agent may change boxes if he wants. The searcher is trying to minimise the expected time to discovery. The agent is trying to minimise this time if he wants to be found, but trying to maximise it otherwise. This paper finds a solution to this game (in a sense defined in the paper), associated strategies for the searcher and each type of agent, and a continuous value function v(p) giving the expected time for the agent to be discovered. The solution method (which is to solve an associated zero-sum game) would apply generally to this type of game of incomplete information.
Production Control Policies in Supply Chains with Selective-Information Sharing
Authors: Huang Boray , Iravani Seyed M. R.
Published: September 2005

We consider a supply chain consisting of one manufacturer (capacitated supplier) and two retailers. We characterize the manufacturer’s optimal production policy under selective-information sharing, in which the manufacturer receives demand and inventory information from only one of the two retailers. We show that the manufacturer’s optimal production policy is a state-dependent base-stock policy and that the base-stock levels have a monotonic structure. We also perform an extensive numerical study to examine how system factors affect the benefit of information sharing and the relative values of information from each retailer. In addition, we identify cases where the cost saving due to receiving information from only one retailer captures most of the saving that can be obtained when the information is received from both retailers. Finally, we investigate the cost effectiveness of echelon-stock policies in systems with full-information sharing and introduce the “information pooling effect” as well as economies of scale with respect to information sharing.
Generation Capacity Expansion in Imperfectly Competitive Restructured Electricity Markets
Authors: Murphy Frederic H. , Smeers Yves
Published: September 2005

We consider three models of investments in generation capacity in restructured electricity systems that differ with respect to their underlying economic assumptions. The first model assumes a perfect, competitive equilibrium. It is very similar to the traditional capacity expansion models even if its economic interpretation is different. The second model (open-loop Cournot game) extends the Cournot model to include investments in new generation capacities. This model can be interpreted as describing investments in an oligopolistic market where capacity is simultaneously built and sold in long-term contracts when there is no spot market. The third model (closed-loop Cournot game) separates the investment and sales decision with investment in the first stage and sales in the second stage—that is, a spot market. This two-stage game corresponds to investments in merchant plants where the first-stage equilibrium problem is solved subject to equilibrium constraints. We show that despite some important differences, the open- and closed-loop games share many properties. One of the important results is that the prices and quantities produced in the closed-loop game, when the solution exists, fall between the prices and quantities in the open-loop game and the competitive equilibrium.
Portfolio Optimization with Factors, Scenarios, and Realistic Short Positions
Authors: Jacobs Bruce I. , Levy Kenneth N. , Markowitz Harry M.
Published: September 2005

This paper presents fast algorithms for calculating mean-variance efficient frontiers when the investor can sell securities short as well as buy long, and when a factor and/or scenario model of covariance is assumed. Currently, fast algorithms for factor, scenario, or mixed (factor and scenario) models exist, but (except for a special case of the results reported here) apply only to portfolios of long positions. Factor and scenario models are used widely in applied portfolio analysis, and short sales have been used increasingly as part of large institutional portfolios. Generally, the critical line algorithm (CLA) traces out mean-variance efficient sets when the investor’s choice is subject to any system of linear equality or inequality constraints. Versions of CLA that take advantage of factor and/or scenario models of covariance gain speed by greatly simplifying the equations for segments of the efficient set. These same algorithms can be used, unchanged, for the long-short portfolio selection problem provided a certain condition on the constraint set holds. This condition usually holds in practice.
Lot Sizing with Inventory Bounds and Fixed Costs: Polyhedral Study and Computation
Authors: Atamtürk Alper , Küçükyavuz Simge
Published: September 2005

We investigate the polyhedral structure of the lot-sizing problem with inventory bounds. We consider two models, one with linear cost on inventory, the other with linear and fixed costs on inventory. For both models, we identify facet-defining inequalities that make use of the inventory bounds explicitly and give exact separation algorithms. We also describe a linear programming formulation of the problem when the order and inventory costs satisfy the Wagner-Whitin nonspeculative property. We present computational experiments that show the effectiveness of the results in tightening the linear programming relaxations of the lot-sizing problem with inventory bounds and fixed costs.
Novel Protein Markers of Acute Coronary Syndrome Complications in Low-Risk Outpatients: A Systematic Review of Potential Use in the Emergency Department
Authors: Mitchell Alice M , Brown Michael D , Menown Ian BA , Kline Jeffery A
Published: September 2005

Background: Published literature was systematically reviewed to determine the diagnostic accuracy of new protein markers of acute coronary syndromes (ACS) in symptomatic outpatients at low risk of ACS and related complications comparable to patients evaluated in emergency department chest pain units.

Methods: Studies were identified by a MEDLINE® (1966 to May week 3, 2005) search. Abstracts were reviewed for relevance, and manuscripts were included by the independent consensus of 2 observers based on explicit criteria restricting the analysis to studies relevant to screening ambulatory patients with symptoms suggesting ACS. Publication bias was identified by a modified funnel plot analysis [study size (y) vs the inverse of the negative likelihood ratio (x)]. Results of individual markers were reported separately. When 3 or more eligible studies were identified, data were aggregated by use of the summary ROC (SROC) curve.

Results: Twenty-two protein markers in 10 unique populations met the inclusion criteria. Data required for SROC analysis (true- and false-positive rates) were available for 17 markers, in 9 unique populations, from publications and personal communications. Of these, only C-reactive protein was published in more than 2 populations to allow aggregation (6 studies total). C-Reactive protein demonstrated poor diagnostic performance on SROC curve analysis, with an area under the curve of 0.61 and a pooled diagnostic odds ratio of 1.81 (95% confidence interval, 1.06–3.07).

Conclusion: Published evidence is not sufficient to support the routine use of new protein markers in screening for ACS in the emergency department setting.
Clinical Applications of Whole-Blood PCR with Real-Time Instrumentation
Authors: Castley Alison , Higgins Melinda , Ivey John , Mamotte Cyril , Sayer David C , Christiansen Frank T
Published: September 2005

Background: As the genetic basis of many human diseases is being discovered, there is increasing need for the detection of single-nucleotide polymorphisms/mutations in medical laboratories. We describe an innovative approach that combines PCR amplification directly on whole blood and real-time detection PCR technology (WB-RTD PCR).

Methods: We compared WB-RTD PCR with the method for extracted DNA-RTD PCR for the detection of mutations in the prothrombin (n = 94), factor V Leiden (n = 49), and hemochromatosis (n = 22) genes. Mutation detection on the Roche LightCycler was based on use of fluorescence resonance energy transfer (FRET) probes and melting curve analysis. We also compared the WB-RTD PCR on the LightCycler and the ABI Prism™ 7700 sequence detection system with minor groove– binding nonfluorescent quencher probes.

Results: We obtained complete concordance between both methods in assigning genotypes. We also demonstrated that the WB-RTD PCR method can be performed on real-time PCR instruments from Applied Biosystems and the LightCycler. Omission of the need for DNA extraction and gel electrophoresis allowed substantial labor and cost savings with this method.

Conclusion: This approach has applications for testing other medically relevant single-nucleotide polymorphisms.
Nonradioactive Vitamin B12 Absorption Test Evaluated in Controls and in Patients with Inherited Malabsorption of Vitamin B12
Authors: Bor Mustafa Vakur , Çetin Mualla , Aytaç Selin , Altay Çiğdem , Nexo Ebba
Published: September 2005

Background: Current tests for evaluation of vitamin B12 absorption are problematic because they involve the use of radioactively labeled vitamin B12. We describe a vitamin B12 absorption test that circumvents this problem.

Methods: We measured cobalamin or transcobalamin saturated with cobalamin (holo-TC) 24 h after three 9-μg doses of vitamin B12 given orally at 6-h intervals. We studied 17 patients with inherited malabsorption of vitamin B12 attributable to Imerslund–Grasbeck syndrome (n = 13) or intrinsic factor deficiency (n = 4), their obligate heterozygous biological parents (n = 19), and healthy controls (n = 44).

Results: In the patients, the median (range) change of holo-TC after the B12 load was not significant [1 (−42 to 5) pmol/L], nor was the change of cobalamin [−3 (−32 to 22) pmol/L], consistent with a lack of measurable active or passive absorption. In controls, however, the median (range) increases of holo-TC and cobalamin were 26 (−6 to 63) pmol/L and 41 (−37 to 109) pmol/L, respectively. Similarly, the parents showed increases of 23 (−2 to 47) pmol/L and 27 (−15 to 94) pmol/L. The mean areas under the ROC curves (95% confidence intervals) were 0.97 (0.93–1.0) for holo-TC and 0.87 (0.79–0.94) for cobalamin, distinguishing patients from controls. At a cutoff of 6 pmol/L for holo-TC, the diagnostic sensitivity (95% confidence interval) was 100 (81–100)%, and the diagnostic specificity was 92 (82–97)%.

Conclusion: Measurement of holo-TC after administration of vitamin B12 is a promising approach for evaluating vitamin B12 absorption.
The Formation of Buyer–Supplier Relationships: Detailed Contract Drafting and Close Partner Selection
Authors: Wuyts Stefan , Geyskens Inge
Published: September 2005

Firms face two strategic decisions when engaging in a new purchase transaction: the decision whether to draft a detailed contract and the decision whether to select a partner with which they share a close tie. The authors study how organizational culture affects these decisions and the effectiveness of these decisions in curtailing the partner's opportunistic behavior. The results suggest that organizational culture exerts an important but different influence on both decisions. Selecting a close partner shows a marked ability to hedge against partner opportunism, but beyond a certain point, it encourages the opportunism it is designed to discourage. Contracting becomes effective only when a nonclose partner is selected and when the focal relationship is embedded in a network of close mutual contacts.
The Role of Spokescharacters as Advertisement and Package Cues in Integrated Marketing Communications
Authors: Garretson Judith A. , Burton Scot
Published: September 2005

Marketers often use verbal claims to highlight brand benefits in marketing communication campaigns. However, spokescharacters may also be incorporated into campaigns and are often featured both in advertisements and on product packages. The authors use three studies to examine various integrated marketing communications (IMC) strategic combinations, including the effects related to the use of spokescharacters versus verbal attributes; advertisement–package coordination; character relevancy; and the presence of new, favorable brand information that may compete for cognitive resources on packages. Based on conceptual rationales drawn from encoding specificity, network associations, and the elaboration likelihood model, the findings offer empirical evidence that pertains to the potential benefits of including spokescharacters in IMC campaigns. Specifically, the use of spokescharacters results in more favorable brand attitudes, even when brand attribute recall is affected adversely by deviations from the primary message conveyed in the IMC campaigns. The authors offer some implications of these and other findings for marketers attempting to affect consumer evaluations favorably with spokescharacters in IMC campaigns.
Are the Drivers and Role of Online Trust the Same for All Web Sites and Consumers? A Large-Scale Exploratory Empirical Study
Authors: Bart Yakov , Shankar Venkatesh , Sultan Fareena , Urban Glen L.
Published: September 2005

The authors develop a conceptual model that links Web site and consumer characteristics, online trust, and behavioral intent. They estimate this model on data from 6831 consumers across 25 sites from eight Web site categories, using structural equation analysis with a priori and post hoc segmentation. The results show that the influences of the determinants of online trust are different across site categories and consumers. Privacy and order fulfillment are the most influential determinants of trust for sites in which both information risk and involvement are high, such as travel sites. Navigation is strongest for information-intensive sites, such as sports, portal, and community sites. Brand strength is critical for high-involvement categories, such as automobile and financial services sites. Online trust partially mediates the relationships between Web site and consumer characteristics and behavioral intent, and this mediation is strongest (weakest) for sites oriented toward infrequently (frequently) purchased, high-involvement items, such as computers (financial services).
Maximizing Profitability and Return on Investment: A Short Clarification on Reinartz, Thomas, and Kumar
Authors: Ambler Tim
Published: September 2005

Reinartz, Thomas, and Kumar (2005) provide a valuable methodology for balancing resources between customer retention and acquisition. They also conclude that optimal profitability (net return) coincides with optimal return on investment. This article clarifies this perhaps surprising conclusion and shows that it arises from the authors' methodology rather than from the data. More conventional analysis of the same data indicates that maximum return on investment is reached with lower expenditure than maximum profitability.
A Customer Relationship Management Roadmap: What is Known, Potential Pitfalls, and Where to Go
Authors: Boulding William , Staelin Richard , Ehret Michael , Johnston Wesley J.
Published: September 2005

The goal of this preface is to describe how the special section on customer relationship management (CRM) was developed. In May 2003, Richard Staelin, Executive Director of the Teradata Center for Customer Relationship Management at Duke University, proposed that Journal of Marketing ( JM) publish a special section. The proposal included activities that were designed to promote interactions among marketing academics and practitioners; the goal was to stimulate dialogue and new research on CRM. I found the proposal attractive because CRM is a broad-based topic that interests many marketers. After extensive discussion, the American Marketing Association (AMA) and the Teradata Center formally agreed to cosponsor the special section. Subsequently, there was a conference on Relationship Marketing and Customer Relationship Management (cochaired by Michael Ehret, Wesley Johnston, Michael Kleinaltenkamp, and Lou Pelton) that took place at Freie Universität Berlin in the summer of 2003; 1 a conference on Customer Management (cosponsored by the Marketing Science Institute and the Teradata Center) that was held at Duke University in March 2004; and two special sessions on CRM that were featured at the AMA Winter Educators' Conference held in San Antonio, Tex., in February 2005. The conferences provided many opportunities for dialogue, and the response from marketers who attended these events was enthusiastic. I also invited Richard Staelin and William Boulding (Executive Codirector of the Teradata Center) to work with me as consulting editors for the special section, and they agreed. A call for papers requested that authors submit their manuscripts to JM by May 2004. The consulting editors and I evaluated every submission with the assistance of an expert panel that included Leonard Berry, John Deighton, Michael Ehret, Christian Grönroos, Sunil Gupta, Wayne Hoyer, Wagner Kamakura, Wesley Johnston, Donald R. Lehmann, Charlotte Mason, Carl Mela, Scott Neslin, Roland Rust, Michel Wedel, and Valarie Zeithaml. All submissions underwent JM's standard double-blind review process, and members of JM's editorial review board served as reviewers. I would like to express my appreciation to everyone who participated in the development of the special section. The culmination of our work together is a set of nine articles and two essays that advance the science and practice of CRM. I hope that these articles stimulate new intellectual discoveries.

—Ruth N. Bolton
A Strategic Framework for Customer Relationship Management
Authors: Payne Adrian , Frow Pennie
Published: September 2005

In this article, the authors develop a conceptual framework for customer relationship management (CRM) that helps broaden the understanding of CRM and its role in enhancing customer value and, as a result, shareholder value. The authors explore definitional aspects of CRM, and they identify three alternative perspectives of CRM. The authors emphasize the need for a cross-functional, process-oriented approach that positions CRM at a strategic level. They identify five key cross-functional CRM processes: a strategy development process, a value creation process, a multichannel integration process, an information management process, and a performance assessment process. They develop a new conceptual framework based on these processes and explore the role and function of each element in the framework. The synthesis of the diverse concepts within the literature on CRM and relationship marketing into a single, process-based framework should provide deeper insight into achieving success with CRM strategy and implementation.
The Role of Relational Information Processes and Technology Use in Customer Relationship Management
Authors: Jayachandran Satish , Sharma Subhash , Kaufman Peter , Raman Pushkala
Published: September 2005

Drawing on the relationship marketing and market information processing literature streams, the authors conceptualize and measure relational information processes, or organizational routines that are critical for customer relationship management (CRM). The authors examine the key drivers and outcome of relational information processes and the role of technology in implementing CRM using data collected from a diverse sample of firms. The results show that relational information processes play a vital role in enhancing an organization's customer relationship performance. By moderating the influence of relational information processes on customer relationship performance, technology used for CRM performs an important and supportive role. The study provides insights into why the use of CRM technology might not always deliver the expected customer relationship performance outcome.
The Effects of Customer Satisfaction, Relationship Commitment Dimensions, and Triggers on Customer Retention
Authors: Gustafsson Anders , Johnson Michael D. , Roos Inger
Published: September 2005

In a study of telecommunications services, the authors examine the effects of customer satisfaction, affective commitment, and calculative commitment on retention. The study further examines the potential for situational and reactional trigger conditions to moderate the satisfaction–retention relationship. The results support consistent effects of customer satisfaction, calculative commitment, and prior churn on retention. Prior churn also moderates the satisfaction–retention relationship. The results have implications for both customer relationship managers and researchers who use satisfaction surveys to predict behavior.
Incorporating Strategic Consumer Behavior into Customer Valuation
Authors: Lewis Michael
Published: September 2005

The calculation of customer value without regard to marketing policy is problematic because the value of managerial flexibility and the impact of consumer learning are neglected. This article develops a structural dynamic programming model of consumer demand that includes marketing variables and consumer expectations of promotions. The author uses the estimated parameters to conduct policy experiments that yield more accurate forecasts of customer value and to study the impact of alternative marketing policies.
Making Customer Relationship Management Work: The Measurement and Profitable Management of Customer Relationships
Authors: Ryals Lynette
Published: September 2005

Customer relationship management (CRM) is perceived to be failing, and there is an urgent need for some practical ways to address this issue. The research presented in this article demonstrates that the implementation of CRM activities delivers greater profits. Using calculations of the lifetime value of customers in two longitudinal case studies, the research finds that customer management strategies change as more is discovered about the value of the customer. These changes lead to better firm performance. The contribution of this article is to show that CRM works and that a relatively straightforward analysis of the value of the customer can make a real difference.
Do Satisfied Customers Buy More? Examining Moderating Influences in a Retailing Context
Authors: Seiders Kathleen , Voss Glenn B. , Grewal Dhruv , Godfrey Andrea L.
Published: September 2005

In this research, the authors propose that the relationship between satisfaction and repurchase behavior is moderated by customer, relational, and marketplace characteristics. They further hypothesize that the moderating effects emerge if repurchase is measured as objective behavior but not if it is measured as repurchase intentions. To test for systematic differences in effects, the authors estimate identical models using both longitudinal repurchase measures and survey measures as the dependent variable. The results suggest that the relationship between customer satisfaction and repurchase behavior is contingent on the moderating effects of convenience, competitive intensity, customer involvement, and household income. As the authors predicted, the results are significantly different for self-reported repurchase intentions and objective repurchase behavior. The conceptual framework and empirical findings reinforce the importance of moderating influences and offer new insights that enhance the understanding of what drives repurchase behavior.
Customer Strategy: Observations from the Trenches
Authors: Rogers Martha
Published: September 2005

This short article traces the evolution of customer relationship management from the perspective of an author who has written, researched, and worked in the field since the beginning of the relationship revolution in the early 1990s. Additional topics for research are suggested, especially in the area of understanding how companies can increase enterprise value by managing the rate of increase in customer equity.
Does Distance Still Matter? Geographic Proximity and New Product Development
Authors: Ganesan Shankar , Malter Alan J. , Rindfleisch Aric
Published: September 2005

Many firms rely on external organizations to acquire knowledge that is useful for developing creative new products and reducing the time needed to bring these products to market. Cluster theory suggests that this knowledge is often obtained from organizations located in close geographic proximity. Specifically, proximity is assumed to foster heightened face-to-face communication, strengthened relational ties, increased knowledge acquisition, and enhanced new product outcomes. The authors identify the limitations of these assumptions and offer an enriched model of the influence of geographic proximity on new product development, which they test using both a cross-sectional survey of 155 firms in the U.S. optics industry and a longitudinal follow-up survey of 73 of these firms. They find that firms located in close proximity engage in increased face-to-face communication, but this communication has little effect on the acquisition of the types of knowledge that lead to enhanced new product outcomes. In contrast, they find that e-mail communication leads to both enhanced new product creativity and development speed. In addition, they find that relational ties moderate rather than mediate the path connecting geographic proximity and new product outcomes. These findings imply that the new product development outcomes typically ascribed to close geographic proximity may actually be attributed to strong relational ties.
Resolving the Capability–Rigidity Paradox in New Product Innovation
Authors: Atuahene-Gima Kwaku
Published: September 2005

Managers face an important strategic dilemma in product innovation: how to exploit existing product innovation competencies (competence exploitation) while avoiding their dysfunctional rigidity effects by renewing and replacing them with entirely new competencies (competence exploration). Although the resolution of what is termed the “capability–rigidity paradox” is considered a fundamental managerial task in enhancing product innovation outcomes and the firm's competitive advantage, it has received little research attention. The author argues and finds support that market orientation provides a key to this paradox. Specifically, customer and competitor orientations ensure simultaneous investments in exploiting existing product innovation competencies and exploring new ones. The author also finds that the effects of these orientations on competence exploitation and exploration are differentially moderated by interfunctional coordination and perceived market opportunity. Regarding outcomes, competence exploitation and exploration have opposing relationships with incremental and radical innovation performance. However, the relationship between competence exploration and radical innovation performance is positively moderated by interfunctional coordination. Overall, the results of this study suggest that market orientation can prevent a firm from becoming operationally efficient but strategically inefficient by simultaneously engendering competence exploitation and exploration, which are differentially related to incremental and radical product innovation outcomes.