Field lab Jeronimo Martins: optimization of retail operations - a cluster-based approach to market basket analysis

In the context of retail analytics, market basket analysis serves as a powerful technique to extract valuable knowledge about consumer preferences and shopping habits. Through its application to a Portuguese retailer, the following study examines purchase transaction data and clusters it based on the product categories in consumers’ baskets. With the goal of mining product relationships, this study compares a heuristic and an association rule-based approach for a cluster-based identification of product substitutes and complements. The paper concludes that for finding substitutes, the heuristic fares the best results. For the discovery of product complementarity, an association rule learning-based approach is suited best. Beyond its theoretical contribution, the insights gained through the analyses are utilized to increase customer satisfaction and sales by providing recommendations on managerial decisions, ranging from determining the timing of product promotions, possible improvements to the store’s design, informing product placement decisions, to suggestions regarding customer communication

"Who receives statins? Variations in physicians’ prescribing patterns for patients with coronary heart disease, dyslipidemia, and diabetes"

Our objective is to estimate the extent to which clinical and non-clinical factors are associated with physicians’ prescribing patterns for statins. The data are from the National Ambulatory Medical Care Survey for the period 1992 through 2004. The three samples examined included more than 14,000 patients who were diagnosed with coronary heart disease, high cholesterol, or diabetes, individuals who are most likely to benefit from being prescribed a statin drug. Using a multinomial logit framework, we find disparities in prescribing patterns based on non-clinical factors. Namely, whites and patients who have private insurance are more likely to be prescribed a statin than nonwhites and those with public insurance. Also, even though a large increase occurred in the uptake of statins over the period 1992 to 2004, our results for 2004 show that only about 50 percent of patients diagnosed with coronary heart disease were prescribed a statin. Because coronary heart disease is the leading cause of death in the U.S. and currently is estimated to cost over $150 billion annually in the U.S. in direct and indirect costs, observed differences in prescribing patterns along these dimensions is troubling and should be part of discussions dealing with health care reform.Pharmaceuticals; Statins; Equity in Physician Prescribing Patterns; Insurance

A Comparative Study of Adult Learners’ Motivation for Learning English as a Foreign Language According to Their Instruction by Single or Multiple Instructors at Geos Language Centre, Thailand

The purpose of this quantitative study was to compare adult learners’ motivation for learning English as a foreign language according to their instruction by either a single instructor or by multiple instructors over a period of six weeks at Geos Language Centre in Bangkok, Thailand. The sample population of this study consisted of 67 adult-learner students enrolled in private English as a foreign language courses during the period of April to July 2020. These students comprised two groups under investigation during the period of this study: 1) Those who received instruction from a single instructor, and 2) Those who received instruction from multiple instructors. The Questionnaire for Measuring Motivation for Learning English as a Foreign Language (QMMLEFL), adapted from the Attitude / Motivation Test Battery (AMTB) by Gardner (2004), was used to measure the level of adult learners’ motivation for learning English as a foreign language (EFL). Descriptive statistics (means and standard deviations) were calculated, and statistical hypothesis testing (comparative analysis using paired samples t-tests and an independent samples t-test) was performed from data collected to pursue the research objectives and accept or reject the research hypotheses of this study. The research findings did not indicate that there was a statistically significant difference in the gain in motivation for learning English as a foreign language over a six-week period of study between adult learners who studied with a single instructor and adult learners who studied with multiple instructors. Recommendations for adult learners and instructors of English as a foreign language and language institute administrators and future researchers are provided

Evaluation of radiological workstations and web-browser-based image distribution clients for a PACS project in hands-on workshops

The methodology and outcome of a hands-on workshop for the evaluation of PACS (picture archiving and communication system) software for a multihospital PACS project are described. The following radiological workstations and web-browser-based image distribution software clients were evaluated as part of a multistep evaluation of PACS vendors in March 2001: Impax DS 3000 V 4.1/Impax Web1000 (Agfa-Gevaert, Mortsel, Belgium); PathSpeed V 8.0/PathSpeed Web (GE Medical Systems, Milwaukee, Wis., USA); ID Report/ID Web (Image Devices, Idstein, Germany); EasyVision DX/EasyWeb (Philips Medical Systems, Eindhoven, Netherlands); and MagicView 1000 VB33a/MagicWeb (Siemens Medical Systems, Erlangen, Germany). A set of anonymized DICOM test data was provided to enable direct image comparison. Radiologists (n=44) evaluated the radiological workstations and nonradiologists (n=53) evaluated the image distribution software clients using different questionnaires. One vendor was not able to import the provided DICOM data set. Another vendor had problems in displaying imported cross-sectional studies in the correct stack order. Three vendors (Agfa-Gevaert, GE, Philips) presented server-client solutions with web access. Two (Siemens, Image Devices) presented stand-alone solutions. The highest scores in the class of radiological workstations were achieved by ID Report from Image Devices (p<0.005). In the class of image distribution clients, the differences were statistically not significant. Questionnaire-based evaluation was shown to be useful for guaranteeing systematic assessment. The workshop was a great success in raising interest in the PACS project in a large group of future clinical users. The methodology used in the present study may be useful for other hospitals evaluating PAC

Evaluation of radiological workstations and web-browser-based image distribution clients for a PACS project in hands-on workshops

The methodology and outcome of a hands-on workshop for the evaluation of PACS (picture archiving and communication system) software for a multihospital PACS project are described. The following radiological workstations and web-browser-based image distribution software clients were evaluated as part of a multistep evaluation of PACS vendors in March 2001: Impax DS 3000 V 4.1/Impax Web1000 (Agfa-Gevaert, Mortsel, Belgium); PathSpeed V 8.0/PathSpeed Web (GE Medical Systems, Milwaukee, Wis., USA); ID Report/ID Web (Image Devices, Idstein, Germany); EasyVision DX/EasyWeb (Philips Medical Systems, Eindhoven, Netherlands); and MagicView 1000 VB33a/MagicWeb (Siemens Medical Systems, Erlangen, Germany). A set of anonymized DICOM test data was provided to enable direct image comparison. Radiologists (n=44) evaluated the radiological workstations and nonradiologists (n=53) evaluated the image distribution software clients using different questionnaires. One vendor was not able to import the provided DICOM data set. Another vendor had problems in displaying imported cross-sectional studies in the correct stack order. Three vendors (Agfa-Gevaert, GE, Philips) presented server-client solutions with web access. Two (Siemens, Image Devices) presented stand-alone solutions. The highest scores in the class of radiological workstations were achieved by ID Report from Image Devices (p<0.005). In the class of image distribution clients, the differences were statistically not significant. Questionnaire-based evaluation was shown to be useful for guaranteeing systematic assessment. The workshop was a great success in raising interest in the PACS project in a large group of future clinical users. The methodology used in the present study may be useful for other hospitals evaluating PAC

Supercritical fluid extraction-supercritical fluid chromatography of saliva: Single-quadrupole mass spectrometry monitoring of caffeine for gastric emptying studies†

Saliva is an attractive sampling matrix for measuring various endogenous and exogeneous substances but requires sample treatment prior to chromatographic analysis. Exploiting supercritical CO2 for both extraction and chromatography simplifies sample preparation, reduces organic solvent consumption, and minimizes exposure to potentially infectious samples, but has not yet been applied to oral fluid. Here, we demonstrate the feasibility and benefits of online supercritical fluid extraction coupled to supercritical fluid chromatography and single-quadrupole mass spectrometry for monitoring the model salivary tracer caffeine. A comparison of 13C- and 32S-labeled internal standards with external standard calibration confirmed the superiority of stable isotope-labeled caffeine over nonanalogous internal standards. As proof of concept, the validated method was applied to saliva from a magnetic resonance imaging study of gastric emptying. After administration of 35 mg caffeine via ice capsule, salivary levels correlated with magnetic resonance imaging data, corroborating caffeine's usefulness as tracer of gastric emptying (R2 = 0.945). In contrast to off-line methods, online quantification required only minute amounts of organic solvents and a single manual operation prior to online bioanalysis of saliva, thus demonstrating the usefulness of CO2-based extraction and separation techniques for potentially infective biomatrices

Supercritical fluid extraction–supercritical fluid chromatography of saliva: Single‐quadrupole mass spectrometry monitoring of caffeine for gastric emptying studies †

Abstract Saliva is an attractive sampling matrix for measuring various endogenous and exogeneous substances but requires sample treatment prior to chromatographic analysis. Exploiting supercritical CO 2 for both extraction and chromatography simplifies sample preparation, reduces organic solvent consumption, and minimizes exposure to potentially infectious samples, but has not yet been applied to oral fluid. Here, we demonstrate the feasibility and benefits of online supercritical fluid extraction coupled to supercritical fluid chromatography and single‐quadrupole mass spectrometry for monitoring the model salivary tracer caffeine. A comparison of 13 C‐ and 32 S‐labeled internal standards with external standard calibration confirmed the superiority of stable isotope‐labeled caffeine over nonanalogous internal standards. As proof of concept, the validated method was applied to saliva from a magnetic resonance imaging study of gastric emptying. After administration of 35 mg caffeine via ice capsule, salivary levels correlated with magnetic resonance imaging data, corroborating caffeine's usefulness as tracer of gastric emptying ( R 2 = 0.945). In contrast to off‐line methods, online quantification required only minute amounts of organic solvents and a single manual operation prior to online bioanalysis of saliva, thus demonstrating the usefulness of CO 2 ‐based extraction and separation techniques for potentially infective biomatrices

Assessing fishery and ecological consequences of alternate management options for multispecies fisheries

Demands for management advice on mixed and multispecies fisheries pose many challenges, further complicated by corresponding requests for advice on the environmental impacts of alternate management options. Here, we develop, and apply to North Sea fisheries, a method for collectively assessing the effects of, and interplay between, technical interactions, multispecies interactions, and the environmental effects of fishing. Ecological interactions involving 21 species are characterized with an ensemble of 188 plausible parameterizations of size-based multispecies models, and four fleets (beam trawl, otter trawl, industrial, and pelagic) characterized with catch composition data. We use the method to evaluate biomass and economic yields, alongside the risk of stock depletion and changes in the value of community indicators, for 10 000 alternate fishing scenarios (combinations of rates of fishing mortality F and fleet configuration) and present the risk vs. reward trade-offs. Technical and multispecies interactions linked to the beam and otter trawl fleets were predicted to have the strongest effects on fisheries yield and value, risk of stock collapse and fish community indicators. Increasing beam trawl effort led to greater increases in beam trawl yield when otter trawl effort was low. If otter trawl effort was high, increases in beam trawl effort led to reduced overall yield. Given the high value of demersal species, permutations of fleet effort leading to high total yield (generated primarily by pelagic species) were not the same as permutations leading to high catch values. A transition from F for 1990 to 2010 to FMSY, but without changes in fleet configuration, reduced risk of stock collapse without affecting long-term weight or value of yield. Our approach directly addresses the need for assessment methods that treat mixed and multispecies issues collectively, address uncertainty, and take account of trade-offs between weight and value of yield, state of stocks and state of the environment

Determination of pyridoxal-5′-phosphate (PLP)-bonding sites in proteins: a peptide mass fingerprinting approach based on diagnostic tandem mass spectral features of PLP-modified peptides

Peptides modified by pyridoxal-5′-phosphate (PLP), linked to a lysine residue via reductive amination, exhibit distinct spectral characteristics in the collision-induced dissociation (CID) tandem mass (MS/MS) spectra that are described here. The MS/MS spectra typically display two dominant peaks whose m/z values correspond to neutral losses of [H 3 PO 4 ] (−98 Da) and the PLP moiety as [C 8 H 10 NO 5 P] (−231 Da) from the precursor peptide ion, respectively. Few other peaks are observed. Recognition of this distinct fragmentation behavior is imperative since determining sequences and sites of modifications relies on the formation of amide backbone cleavage products for subsequent interpretation via proteome database searching. Additionally, PLP-modified peptides exhibit suppressed precursor ionization efficiency which diminishes their detection in complex mixtures. Presented here is a protocol which describes an enrichment strategy for PLP-modified peptides combined with neutral loss screening and peptide mass fingerprinting to map the PLP-bonding site in a known PLP-dependent protein. This approach represents an efficient alternative to site-directed mutagenesis which has been the traditional method used for PLP-bonding site localization in proteins. Copyright © 2009 John Wiley & Sons, Ltd.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/64342/1/4270_ftp.pd