bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessing control of postural stability in community-living older adults using performance-based limits of stability
Authors: Jbabdi Myriam , Boissy Patrick , Hamel Mathieu
Published: April 2008

Background

Balance disability measurements routinely used to identify fall risks in frail populations have limited value in the early detection of postural stability deficits in community-living older adults. The objectives of the study were to 1) measure performance-based limits of stability (LOS) in community-living older adults and compare them to theoretical LOS computed from data proposed by the Balance Master® system, 2) explore the feasibility of a new measurement approach based on the assessment of postural stability during weight-shifting tasks at performance-based LOS, 3) quantify intra-session performance variability during multiple trials using the performance-based LOS paradigm.

Methods

Twenty-four healthy community-living older adults (10 men, 14 women) aged between 62 to 85 (mean age ± sd, 71.5 ± 6 yrs) participated in the study. Subjects' performance-based LOS were established by asking them to transfer their body weight as far as possible in three directions (forward, right and left) without changing their base of support. LOS were computed as the maximal excursion of the COP in each direction among three trials. Participants then performed two experimental tasks that consisted in controlling, with the assistance of visual feedback, their centre of pressure (COP) within two predefined targets set at 100% of their performance-based LOS. For each tasks 8 trials were performed. Ground reaction forces and torques during performance-based LOS evaluation and experimental tasks were recorded with a force plate. Sway area and medio-lateral mean COP displacement speed variables were extracted from force plate recordings.

Results

Significant differences between theoretical LOS computed from maximum leaning angles derived from anthropometric characteristics and performance-based LOS were observed. Results showed that a motor learning effect was present as the participants optimized their weight-shifting strategy through the first three trials of each task using the visual biofeedback provided on their COP. Reliable measures of control of postural stability at performance-based LOS can be obtained after two additional trials after the learning phase (0.69 > ICC > 1.0).

Conclusion

Establishing performance-based LOS instead of relying on estimations of theoretical LOS offers a more individualized and realistic insight on the true LOS of an individual. Performance-based LOS can be used as targets during weight-shifting postural tasks with real time visual feedback of the COP displacement to assess postural stability of community-living older adults. In order to obtain reliable results, a learning phase allowing subjects to learn how to control their COP displacement is needed.
Primary breast lymphoma: Patient profile, outcome and prognostic factors. A multicentre Rare Cancer Network study
Authors: Jeanneret-Sozzi Wendy , Taghian Alphonse , Epelbaum Ron , Poortmans Philip , Zwahlen Daniel , Amsler Beat , Villette Sylviane , Belkacémi Yazid , Nguyen Tan , Scalliet Pierre , Maingon Philippe , Gutiérrez Cristina , Gastelblum Pauline , Krengli Marco , Raad Rita Abi , Ozsahin Mahmut , Mirimanoff René-Olivier
Published: April 2008

Background

To asses the clinical profile, treatment outcome and prognostic factors in primary breast lymphoma (PBL).

Methods

Between 1970 and 2000, 84 consecutive patients with PBL were treated in 20 institutions of the Rare Cancer Network. Forty-six patients had Ann Arbor stage IE, 33 stage IIE, 1 stage IIIE, 2 stage IVE and 2 an unknown stage. Twenty-one underwent a mastectomy, 39 conservative surgery and 23 biopsy; 51 received radiotherapy (RT) with (n = 37) or without (n = 14) chemotherapy. Median RT dose was 40 Gy (range 12–55 Gy).

Results

Ten (12%) patients progressed locally and 43 (55%) had a systemic relapse. Central nervous system (CNS) was the site of relapse in 12 (14%) cases. The 5-yr overall survival, lymphoma-specific survival, disease-free survival and local control rates were 53%, 59%, 41% and 87% respectively. In the univariate analyses, favorable prognostic factors were early stage, conservative surgery, RT administration and combined modality treatment. Multivariate analysis showed that early stage and the use of RT were favorable prognostic factors.

Conclusion

The outcome of PBL is fair. Local control is excellent with RT or combined modality treatment but systemic relapses, including that in the CNS, occurs frequently.
The HIM (Health for Izhevsk Men) trial protocol
Authors: Tomkins Susannah , Allen Elizabeth , Savenko Olga , McCambridge Jim , Saburova Lyudmila , Kiryanov Nikolay , Oralov Alexey , Gil Artyom , Leon David A , McKee Martin , Elbourne Diana
Published: April 2008

Background

Russia is one of the very few industrialised countries in the world where life expectancy has been declining. Alcohol has been implicated as a major contributor to the rapid fluctuations observed in male life expectancy since 1985 that have been particularly marked among working-age men.

One approach to reducing the alcohol problem in Russia is 'brief interventions' which seek to change views of the personal acceptability of excessive drinking and to encourage self-directed behaviour change. There is limited understanding in Russia of the salience and applicability of Motivational Interviewing (MI), a well-defined brief intervention commonly used to target alcohol-related behaviour, but MI may have important potential for success within the Russian context.

Methods/Design

The study will be an individually randomised two-armed parallel group exploratory trial. The primary hypothesis is that a brief adaptation of MI will be effective in reducing self-reported hazardous drinking at 3 months. The secondary hypothesis is that it will be effective in reducing self-reported past week beverage alcohol consumption, alcohol dependence and related problems at 3 months and at 12 months. MI will also be effective at 12 months in reducing self-reported hazardous drinking, alcohol dependence and related problems, proxy reported hazardous drinking, and recent alcohol use as indicated by bio-markers.

Participants are drawn from the Izhevsk Family Study II, with eligibility determined based on proxy reports of hazardous drinking in the past year. All participants undergo a health check, with MI subsequently delivered to those in the intervention arm. Signed consent is obtained from those in the intervention arm at this point. Both groups are then invited for 3 and 12 month follow ups. The control group will not receive any additional intervention.

Trial Registration

ISRCTN82405938
Bionomics of Anopheles latens in Kapit, Sarawak, Malaysian Borneo in relation to the transmission of zoonotic simian malaria parasite Plasmodium knowlesi
Authors: Tan Cheong H , Vythilingam Indra , Matusop Asmad , Chan Seng T , Singh Balbir
Published: April 2008

Background

A large focus of human infections with Plasmodium knowlesi, a simian parasite naturally found in long-tailed and pig-tailed macaques was discovered in the Kapit Division of Sarawak, Malaysian Borneo. A study was initiated to identify the vectors of malaria, to elucidate where transmission is taking place and to understand the bionomics of the vectors in Kapit.

Methods

Three different ecological sites in the forest, farm and longhouse in the Kapit district were selected for the study. Mosquitoes were collected by human landing collection at all sites and at the forest also by monkey-baited-traps situated on three different levels. All mosquitoes were identified and salivary glands and midguts of anopheline mosquitoes were dissected to determine the presence of malaria parasites.

Results and Discussions

Over an 11-month period, a total of 2,504 Anopheles mosquitoes comprising 12 species were caught; 1,035 at the farm, 774 at the forest and 425 at the longhouse. Anopheles latens (62.3%) and Anopheles watsonii (30.6%) were the predominant species caught in the forested ecotypes, while in the farm Anopheles donaldi (49.9%) and An. latens (35.6%) predominated. In the long house, An. latens (29.6%) and An. donaldi (22.8%) were the major Anopheline species. However, An. latens was the only mosquito positive for sporozoites and it was found to be attracted to both human and monkey hosts. In monkey-baited net traps, it preferred to bite monkeys at the canopy level than at ground level. An. latens was found biting early as 18.00 hours.

Conclusion

Anopheles latens is the main vector for P. knowlesi malaria parasites in the Kapit District of Sarawak, Malaysian Borneo. The study underscores the relationship between ecology, abundance and bionomics of anopheline fauna. The simio-anthropophagic and acrodendrophilic behaviour of An. latens makes it an efficient vector for the transmission of P. knowlesi parasites to both human and monkey hosts.
Effects of electromagnetic fields of low frequency and low intensity on rat metabolism
Authors: Gerardi Gabriele , De Ninno Antonella , Prosdocimi Marco , Ferrari Vanni , Barbaro Filippo , Mazzariol Sandro , Bernardini Daniele , Talpo Getullio
Published: April 2008

A series of experiments on rats have been performed, to study the effects of long time (50 days) exposure to electromagnetic fields of extremely low frequency (ELF, i.e. less than 100 Hz) and amplitude (non thermal), testing whether the metabolic processes would be affected. The background lies on recent observations on the behaviour of isolated enzymes in vitro exposed to EFL fields. In these experiments, the cyclotron (or Larmor) frequency of the metallic ion has been used to "stimulate" the metalloproteins redox-active site, thus obtaining a clear variation of the enzyme functionality. In this paper we have extended for the first time the check to more complex animal metabolism. The novelty of this approach implies that a large amount of data had to be analyzed since it was not possible, in principle, to select only a few parameters among all the potential effects. Several biochemical parameters have been evaluated by comparing their values during the periods of exposure (field ON) and non exposure (field OFF). The evidence that long term exposure to electromagnetic fields with a well defined frequency may have relevant effects on parameters such as body weight, blood glucose and fatty acid metabolism has been obtained.
Evolutionary primacy of sodium bioenergetics
Authors: Mulkidjanian Armen Y , Galperin Michael Y , Makarova Kira S , Wolf Yuri I , Koonin Eugene V
Published: April 2008

Background

The F- and V-type ATPases are rotary molecular machines that couple translocation of protons or sodium ions across the membrane to the synthesis or hydrolysis of ATP. Both the F-type (found in most bacteria and eukaryotic mitochondria and chloroplasts) and V-type (found in archaea, some bacteria, and eukaryotic vacuoles) ATPases can translocate either protons or sodium ions. The prevalent proton-dependent ATPases are generally viewed as the primary form of the enzyme whereas the sodium-translocating ATPases of some prokaryotes are usually construed as an exotic adaptation to survival in extreme environments.

Results

We combine structural and phylogenetic analyses to clarify the evolutionary relation between the proton- and sodium-translocating ATPases. A comparison of the structures of the membrane-embedded oligomeric proteolipid rings of sodium-dependent F- and V-ATPases reveals nearly identical sets of amino acids involved in sodium binding. We show that the sodium-dependent ATPases are scattered among proton-dependent ATPases in both the F- and the V-branches of the phylogenetic tree.

Conclusion

Barring convergent emergence of the same set of ligands in several lineages, these findings indicate that the use of sodium gradient for ATP synthesis is the ancestral modality of membrane bioenergetics. Thus, a primitive, sodium-impermeable but proton-permeable cell membrane that harboured a set of sodium-transporting enzymes appears to have been the evolutionary predecessor of the more structurally demanding proton-tight membranes. The use of proton as the coupling ion appears to be a later innovation that emerged on several independent occasions.

Reviewers

This article was reviewed by J. Peter Gogarten, Martijn A. Huynen, and Igor B. Zhulin. For the full reviews, please go to the Reviewers' comments section.
A scoring matrix approach to detecting miRNA target sites
Authors: Moxon Simon , Moulton Vincent , Kim Jan T
Published: April 2008

Background

Experimental identification of microRNA (miRNA) targets is a difficult and time consuming process. As a consequence several computational prediction methods have been devised in order to predict targets for follow up experimental validation. Current computational target prediction methods use only the miRNA sequence as input. With an increasing number of experimentally validated targets becoming available, utilising this additional information in the search for further targets may help to improve the specificity of computational methods for target site prediction.

Results

We introduce a generic target prediction method, the Stacking Binding Matrix (SBM) that uses both information about the miRNA as well as experimentally validated target sequences in the search for candidate target sequences. We demonstrate the utility of our method by applying it to both animal and plant data sets and compare it with miRanda, a commonly used target prediction method.

Conclusion

We show that SBM can be applied to target prediction in both plants and animals and performs well in terms of sensitivity and specificity. Open source code implementing the SBM method, together with documentation and examples are freely available for download from the address in the Availability and Requirements section.
Gluten-free vegan diet induces decreased LDL and oxidized LDL levels and raised atheroprotective natural antibodies against phosphorylcholine in patients with rheumatoid arthritis: a randomized study
Authors: Elkan Ann-Charlotte , Sjöberg Beatrice , Kolsrud Björn , Ringertz Bo , Hafström Ingiäld , Frostegård Johan
Published: April 2008

Introduction

The purpose of this study was to investigate the effects of vegan diet in patients with rheumatoid arthritis (RA) on blood lipids oxidized low-density lipoprotein (oxLDL) and natural atheroprotective antibodies against phosphorylcholine (anti-PCs).

Methods

Sixty-six patients with active RA were randomly assigned to either a vegan diet free of gluten (38 patients) or a well-balanced non-vegan diet (28 patients) for 1 year. Thirty patients in the vegan group completed more than 3 months on the diet regimen. Blood lipids were analyzed by routine methods, and oxLDL and anti-PCs were analyzed by enzyme-linked immunosorbent assay. Data and serum samples were obtained at baseline and after 3 and 12 months.

Results

Mean ages were 50.0 years for the vegan group and 50.8 years for controls. Gluten-free vegan diet induced lower body mass index (BMI) and low-density lipoprotein (LDL) and higher anti-PC IgM than control diet (p < 0.005). In the vegan group, BMI, LDL, and cholesterol decreased after both 3 and 12 months (p < 0.01) and oxLDL after 3 months (p = 0.021) and trendwise after 12 months (p = 0.090). Triglycerides and high-density lipoprotein did not change. IgA anti-PC levels increased after 3 months (p = 0.027) and IgM anti-PC levels increased trendwise after 12 months (p = 0.057). There was no difference in IgG anti-PC levels. In the control diet group, IgM anti-PC levels decreased both after 3 and 12 months (p < 0.01). When separating vegan patients into clinical responders and non-responders at 12 months, the effects on oxLDL and anti-PC IgA were seen only in responders (p < 0.05).

Conclusion

A gluten-free vegan diet in RA induces changes that are potentially atheroprotective and anti-inflammatory, including decreased LDL and oxLDL levels and raised anti-PC IgM and IgA levels.
Exogenous tumour necrosis factor α induces suppression of autoimmune arthritis
Authors: Kim Eugene Y , Chi Howard H , Rajaiah Rajesh , Moudgil Kamal D
Published: April 2008

Introduction

Our previous studies showed that arthritic Lewis (LEW) rats produced the highest levels of tumour necrosis factor (TNF)α in the recovery phase of adjuvant arthritis (AA), suggesting a correlation between high TNFα levels and reduced severity of arthritis. To further explore this correlation, we compared the TNFα secretion profile of the AA-resistant Wistar Kyoto (WKY) rats with that of LEW rats, determined the effect of exogenous TNFα on the course of AA in LEW rats, and examined various mechanisms involved in TNFα-induced disease modulation.

Methods

A cohort each of LEW and WKY rats was immunised subcutaneously with heat-killed Mycobacterium tuberculosis H37Ra (Mtb). At different time points thereafter, subgroups of rats were killed and their draining lymph node cells were tested for cytokine production. Another group of LEW rats was injected with TNFα intraperitoneally daily for a total of 10 injections, 3 before and 6 after Mtb challenge, and then observed for signs of AA. In parallel, TNFα-treated rats were examined for changes in other cytokines, in CD4+CD25+ T cell frequency, and in indoleamine 2,3-dioxygenase (IDO) mRNA expression levels.

Results

LEW rats displayed a TNFα secretion profile that was opposite to that of the WKY rats. Furthermore, TNFα treatment significantly downmodulated the severity of AA in LEW rats, and decreased the interferon (IFN)-γ secretion in response to the pathogenic determinant of the disease-related antigen. No significant alterations were observed in other parameters tested.

Conclusion

The role of endogenous TNFα in the induction and propagation of arthritis is well established. However, exogenous TNFα can downmodulate the course of AA, displaying an immunoregulatory functional attribute of this cytokine.
Clinical response after two cycles compared to HER2, Ki-67, p53, and bcl-2 in independently predicting a pathological complete response after preoperative chemotherapy in patients with operable carcinoma of the breast
Authors: von Minckwitz Gunter , Sinn Hans-Peter , Raab Günter , Loibl Sibylle , Blohmer Jens-Uwe , Eidtmann Holger , Hilfrich Jörn , Merkle Elisabeth , Jackisch Christian , Costa Serban D , Caputo Angelika , Kaufmann Manfred ,   the German Breast Group (GBG)
Published: April 2008

Introduction

To investigate the predictive value of clinical and biological markers for a pathological complete remission after a preoperative dose-dense regimen of doxorubicin and docetaxel, with or without tamoxifen, in primary operable breast cancer.

Methods

Patients with a histologically confirmed diagnosis of previously untreated, operable, and measurable primary breast cancer (tumour (T), nodes (N) and metastases (M) score: T2-3(≥ 3 cm) N0-2 M0) were treated in a prospectively randomised trial with four cycles of dose-dense (bi-weekly) doxorubicin and docetaxel (ddAT) chemotherapy, with or without tamoxifen, prior to surgery. Clinical and pathological parameters (menopausal status, clinical tumour size and nodal status, grade, and clinical response after two cycles) and a panel of biomarkers (oestrogen and progesterone receptors, Ki-67, human epidermal growth factor receptor 2 (HER2), p53, bcl-2, all detected by immunohistochemistry) were correlated with the detection of a pathological complete response (pCR).

Results

A pCR was observed in 9.7% in 248 patients randomised in the study and in 8.6% in the subset of 196 patients with available tumour tissue. Clinically negative axillary lymph nodes, poor tumour differentiation, negative oestrogen receptor status, negative progesterone receptor status, and loss of bcl-2 were significantly predictive for a pCR in a univariate logistic regression model, whereas in a multivariate analysis only the clinical nodal status and hormonal receptor status provided significantly independent information. Backward stepwise logistic regression revealed a response after two cycles, with hormone receptor status and lymph-node status as significant predictors. Patients with a low percentage of cells stained positive for Ki-67 showed a better response when treated with tamoxifen, whereas patients with a high percentage of Ki-67 positive cells did not have an additional benefit when treated with tamoxifen. Tumours overexpressing HER2 showed a similar response to that in HER2-negative patients when treated without tamoxifen, but when HER2-positive tumours were treated with tamoxifen, no pCR was observed.

Conclusion

Reliable prediction of a pathological complete response after preoperative chemotherapy is not possible with clinical and biological factors routinely determined before start of treatment. The response after two cycles of chemotherapy is a strong but dependent predictor. The only independent factor in this subset of patients was bcl-2.

Trial registration number

NCT00543829
Reduced reliance on the trace element selenium during evolution of mammals
Authors: Lobanov Alexey V , Hatfield Dolph L , Gladyshev Vadim N
Published: April 2008

Background

Selenium (Se) is an essential trace element that occurs in proteins in the form of selenocysteine (Sec). It is transported throughout the body in the form of Sec residues in Selenoprotein P (SelP), a plasma protein of unclear origin recently proposed as an experimental marker of dietary Se status.

Results

Here, we report that the amino-terminal domain of SelP is distantly related to ancestral bacterial thiol oxidoreductases of the thioredoxin superfamily, and that its carboxy-terminal Se transport domain may have originated in early metazoan evolution by de novo accumulation of Sec residues. Reconstruction of evolutionary changes in the Se transport domain indicates a decrease in Sec content of SelP specifically in the mammalian lineage via replacement of Sec with cysteine (Cys). Sec content of mammalian SelPs varies more than two-fold and is lowest in rodents and primates. Compared to mammals, fish show higher Sec content of SelP, larger selenoproteomes, elevated SelP gene expression, and higher levels of tissue Se. In addition, mammals replaced Sec with Cys in several proteins and lost several selenoproteins altogether, whereas such events are not found in fish.

Conclusion

These data suggest that evolution from fish to mammals was accompanied by decreased use of Sec and that analyses of SelP, selenoproteomes and Sec/Cys transitions provide a genetic marker of utilization of this trace element in vertebrates. The evolved reduced reliance on Se raises questions regarding the need to maximize selenoprotein expression by Se dietary supplements in situations when pathology is not imminent, a currently accepted practice.
Prediction Model for Estimating the Survival Benefit of Adjuvant Radiotherapy for Gallbladder Cancer
Authors: Wang Samuel J. , Fuller C. David , Kim Jong-Sung , Sittig Dean F. , Thomas Charles R. , Ravdin Peter M.
Published: April 2008

Purpose

The benefit of adjuvant radiotherapy (RT) for gallbladder cancer remains controversial because most published data are from small, single-institution studies. The purpose of this study was to construct a survival prediction model to enable individualized predictions of the net survival benefit of adjuvant RT for gallbladder cancer patients based on specific tumor and patient characteristics.

Methods

A multivariate Cox proportional hazards model was constructed using data from 4,180 patients with resected gallbladder cancer diagnosed from 1988 to 2003 from the Surveillance, Epidemiology, and End Results database. Patient and tumor characteristics were included as covariates and assessed for association with overall survival (OS) with and without adjuvant RT. The model was internally validated for discrimination and calibration using bootstrap resampling.

Results

On multivariate regression analysis, the model showed that age, sex, papillary histology, stage, and adjuvant RT were significant predictors of OS. The survival prediction model demonstrated good calibration and discrimination, with a bootstrap-corrected concordance index of 0.71. The model predicts that adjuvant RT provides a survival benefit in node-positive or ≥ T2 disease. A nomogram and a browser-based software tool were built from the model that can calculate individualized estimates of predicted net survival gain attributable to adjuvant RT, given specific input parameters.

Conclusion

In the absence of large, prospective, randomized, clinical trial data, a regression model can be used to make individualized predictions of the expected survival improvement from the addition of adjuvant RT after gallbladder cancer resection.
Individual Physician Practice Variation in Hematopoietic Cell Transplantation
Authors: Lee Stephanie J. , Joffe Steven , Artz Andrew S. , Champlin Richard E. , Davies Stella M. , Jagasia Madan , Kernan Nancy A. , Loberiza Fausto R. , Soiffer Robert J. , Eapen Mary
Published: April 2008

Purpose

Previous studies have evaluated practice variation in hematopoietic cell transplantation (HCT) among transplant centers and countries. There are no studies investigating individual physician practice variation in HCT.

Methods

An international Internet-based survey of transplant physicians collected data on medical decisions made by adult and pediatric HCT physicians. Multivariable analyses identified practitioner and transplant center characteristics predictive of medical decision making.

Results

Analysis of 526 assessable respondents showed a wide variation in management approaches to specific clinical scenarios. Pediatric and adult transplant physicians differed significantly in their management strategies for chronic myeloid leukemia, acute and chronic graft-versus-host disease, and choice of graft source for patients with aplastic anemia. Among adult transplant physicians, there was little agreement on the patient factors favoring reduced intensity conditioning or myeloablative conditioning.

Conclusion

These results emphasize the heterogeneity of worldwide transplant practices. Local preferences or biases likely result in similar patients being offered different transplant and treatment procedures. The degree of practice variation also highlights the need for clinical trials to clarify areas of controversy. Where clinical trials are not feasible, data from observational studies may be the best available evidence to guide practice.
Invited Commentary—Net Promoter, Recommendations, and Business Performance: A Clarification on Morgan and Rego
Authors: Keiningham Timothy L. , Aksoy Lerzan , Cooil Bruce , Andreassen Tor Wallin
Published: April 2008

One of the most controversial findings in Morgan and Rego (2006) was that two widely advocated loyalty metrics, “Net Promoter” and “Number of Recommendations,” have little or no value in predicting the financial outcomes of firms. We argue that neither measure was actually examined and that conclusions about the predictive value of these measures cannot be drawn from their analysis. A primary problem is that the measures used in Morgan and Rego (2006) do not adequately adjust for the presence of neutral word-of-mouth activity. Nevertheless, Morgan and Rego (2006) provide important information regarding other common customer metrics and firm financial outcomes. We are unaware of another longitudinal study that examines the predictive value of satisfaction and loyalty metrics in such a comprehensive way.
Offering Online Recommendations with Minimum Customer Input Through Conjoint-Based Decision Aids
Authors: De Bruyn Arnaud , Liechty John C. , Huizingh Eelko K. R. E. , Lilien Gary L.
Published: April 2008

In their purchase decisions, online customers seek to improve decision quality while limiting search efforts. In practice, many merchants have understood the importance of helping customers in the decision-making process and provide online decision aids to their visitors. In this paper, we show how preference models which are common in conjoint analysis can be leveraged to design a questionnaire-based decision aid that elicits customers' preferences based on simple demographics, product usage, and self-reported preference questions. Such a system can offer relevant recommendations quickly and with minimal customer input. We compare three algorithms—cluster classification, Bayesian treed regression, and stepwise componential regression—to develop an optimal sequence of questions and predict online visitors' preferences. In an empirical study, stepwise componential regression, relying on many fewer and easier-to-answer questions, achieved predictive accuracy equivalent to a traditional conjoint approach.
Probabilistic Goods: A Creative Way of Selling Products and Services
Authors: Fay Scott , Xie Jinhong
Published: April 2008

This paper defines a unique type of product or service offering, termed probabilistic goods, and analyzes a novel selling strategy, termed probabilistic selling (PS). A probabilistic good is not a concrete product or service but an offer involving a probability of getting any one of a set of multiple distinct items. Under the probabilistic selling strategy, a multi-item seller creates probabilistic goods using the existing distinct products or services and offers such probabilistic goods as additional purchase choices. The probabilistic selling strategy allows sellers to benefit from introducing a new type of buyer uncertainty, i.e., uncertainty in product assignments. First, introducing such uncertainty enables sellers to create a “virtual” product or service (i.e., probabilistic good), which opens up a creative way to segment a market. We find that the probabilistic selling strategy is a general marketing tool that has the potential to benefit sellers in many different industries. Second, this paper shows that creating buyer uncertainty in product assignments is a new way for sellers to deal with their own market uncertainty. We illustrate two such benefits: (a) offering probabilistic goods can reduce the seller's information disadvantage and lessen the negative effect of demand uncertainty on profit, and (b) offering probabilistic goods can solve the mismatch between capacity and demand and enhance efficiency. Emerging technology is creating exciting (previously unfeasible) opportunities to implement PS and to obtain these many advantages.
An Efficient Method to Compute Traffic Assignment Problems with Elastic Demands
Authors: Babonneau Frédéric , Vial Jean-Philippe
Published: April 2008

The traffic assignment problem (TAP) with elastic demands can be formulated as an optimization problem, the objective of which is the sum of a congestion function and a disutility function. We propose to use a variant of the analytic center cutting plane method to solve this problem. We test the method on TAP instances with the Bureau of Public Roads congestion function and different demand functions (constant elasticity and linear). The results of the numerical experiments show that it is possible to solve large instances with high accuracy.
Tabu Search, Partial Elementarity, and Generalized k-Path Inequalities for the Vehicle Routing Problem with Time Windows
Authors: Desaulniers Guy , Lessard François , Hadjar Ahmed
Published: April 2008

The vehicle routing problem with time windows consists of delivering goods at minimum cost to a set of customers using an unlimited number of capacitated vehicles assigned to a single depot. Each customer must be visited within a prescribed time window. The most recent successful solution methods for this problem are branch-and-price-and-cut algorithms where the column generation subproblem is an elementary shortest-path problem with resource constraints (ESPPRC). In this paper, we propose new ideas having the potential to improve such a methodology. First, we develop a tabu search heuristic for the ESPPRC that allows, in most iterations, the generation of negative reduced cost columns in a short computation time. Second, to further accelerate the subproblem solution process, we propose to relax the elementarity requirements for a subset of the nodes. This relaxation, however, yields weaker lower bounds. Third, we introduce a generalization of the k-path inequalities and highlight that these generalized inequalities can, in theory, be stronger than the traditional ones. Finally, combining these ideas with the most recent advances published in the literature, we present a wide variety of computational results on the Solomon's 100-customer benchmark instances. In particular, we report solving five previously unsolved instances.
The Prominence Effect in Shanghai Apartment Prices
Authors: Hsee Christopher K. , Dubé Jean-Pierre , Zhang Yan
Published: April 2008

A field study conducted in Shanghai identified a robust inconsistency between real estate developers' desired sales pattern (selling all apartments in a building at similar rates) and the actual sales pattern (selling good apartments faster). The authors explain this inconsistency using Tversky, Sattath, and Slovic's (1988) prominence principle, according to which buyers, who were in a choice mode, weighed the desirability of floors more heavily than developers, who were in a matching mode when setting prices. This explanation is corroborated by controlled experiments involving potential home buyers and professional real estate price setters. The research relates an intriguing anomaly originally found in paper-and-pencil surveys to a real-world issue in one of the world's most active markets. These findings also have implications for issues beyond real estate markets.
The Role of Purchase Quantity in Assortment Choice: The Quantity-Matching Heuristic
Authors: Chernev Alexander
Published: April 2008

Consumers often purchase multiple items from a product category on a single shopping trip. In doing so, they must frequently choose among items that are grouped in assortments, such as those offered by a particular store or brand. This article examines how the number of to-be-purchased items influences consumer choice among assortments. It is argued that when consumers are uncertain about their preferences, they are more likely to prefer an assortment for which the number of available options matches the desired purchase quantity. This prediction is based on the notion that a match between the size of an assortment and the number of to-be-purchased items enables consumers to simplify the selection process by eliminating the need to trade off the benefits and costs of individual choice alternatives—a strategy referred to as the “quantity-matching heuristic.” The theoretical predictions are supported by data from five empirical studies that offer converging evidence for the role of purchase-quantity goals in assortment choice and identify moderating factors and boundary conditions.
The Effect of Competitive Advertising Interference on Sales for Packaged Goods
Authors: Danaher Peter J. , Bonfrer André , Dhar Sanjay
Published: April 2008

Competitive advertising interference can occur when viewers of advertising for a focal brand are also exposed to advertising messages for competing brands within a short period (e.g., one week for television advertising). Although competitive advertising interference has been shown to reduce advertising recall and recognition and brand evaluation measures, no studies have examined its impact on brand sales. In this research, the authors use a market response model of sales for two grocery categories for a large grocery chain in the Chicago area to study the extent to which competitive advertising interference influences sales. The model enables the authors to capture the “pure” own-brand advertising elasticities that would arise if there were no competitive interference. The results show that competitive interference effects on sales are strong. When one or more competing brands advertise in the same week as the focal brand, the advertising elasticity diminishes for the focal brand. The decrease depends on the number of competing brands advertising in a particular week and their total advertising volume. The authors find that having one more competitor advertise is often more harmful to a focal brand's advertising effectiveness than if the current number of advertising brands increase their total advertising volume.
Educational Perspectives
Authors: Halamek Louis P.
Published: April 2008

For more than 2 decades, the Neonatal Resuscitation Program (NRP) of the American Academy of Pediatrics (AAP) has set a national standard and international example for training in the resuscitation of the newborn. The concept of a standardized approach to neonatal resuscitation, based on the best available evidence, was revolutionary in 1987 when the NRP was officially launched. Because the NRP continues to adapt, it remains one of the most successful educational interventions in health care. This article describes its genesis, continuing adaptation, and prospects for evolution in the next decade.
Renal Developmental Physiology
Authors: Kelly Lisa K. , Seri Istvan
Published: April 2008

Effective management of fluid and electrolyte homeostasis for the critically ill neonate requires a general understanding of renal development and changes that occur during the transition from the intrauterine to extrauterine environment. The maturation of kidney function and differences in regulation of body fluid tonicity and volume as well as acid-base balance and homeostasis of individual elements between preterm and term infants can have a substantial impact on therapies administered to neonates and the effects of such therapies.
Epidemiologic Features of the Presentation of Critical Congenital Heart Disease: Implications for Screening
Authors: Schultz Amy H. , Localio A. Russell , Clark Bernard J. , Ravishankar Chitra , Videon Nancy , Kimmel Stephen E.
Published: April 2008

OBJECTIVE. Critical congenital heart disease has been proposed as a target of newborn screening. This study aimed to define the incidence and timing of significant physiologic compromise attributable to critical congenital heart disease as well as the distribution of vulnerable lesions. These descriptive parameters must be defined to evaluate the impact and feasibility of any proposed screening strategy.

METHODS. A retrospective cohort study of neonates who had critical congenital heart disease and were admitted to a single institution was conducted. Critical congenital heart disease was defined as congenital heart disease that required invasive intervention or resulted in death in the first 30 days of life. Significant physiologic compromise was defined by severe metabolic acidosis, seizure, cardiac arrest, or laboratory evidence of renal or hepatic injury before invasive intervention. Significant physiologic compromise was classified as potentially preventable when it occurred as a result of undiagnosed congenital heart disease after 12 hours of life.

RESULTS. Significant physiologic compromise occurred in 76 (15.5%) of 490 patients, and potentially preventable significant physiologic compromise occurred in 33 (6.7%) of 490 patients. Most (83%) significant physiologic compromise as a result of unrecognized congenital heart disease occurred after 12 hours of age. A total of 90.9% of cases of potentially preventable significant physiologic compromise had aortic arch obstruction. The incidence of potentially preventable significant physiologic compromise as a result of congenital heart disease in the general population is estimated to be 1 per 15000 to 1 per 26000 live births.

CONCLUSIONS. The incidence and timing of significant physiologic compromise as a result of critical congenital heart disease seems amenable to postnatal screening. Any viable screening strategy must be sensitive for lesions with aortic arch obstruction.
Prevalence and Risk Factors of Elevated Pulmonary Artery Pressures in Children With Sickle Cell Disease
Authors: Pashankar Farzana D. , Carbonella Judith , Bazzy-Asaad Alia , Friedman Alan
Published: April 2008

OBJECTIVES. The objectives of this study were (1) to determine the prevalence and risk factors of elevated pulmonary artery pressures in children with homozygous SS or Sβ° thalassemia using Doppler echocardiography and (2) to determine a correlation between abnormal transcranial Doppler examinations and elevated pulmonary artery pressures.

METHODS. Screening echocardiograms were prospectively performed during an annual comprehensive clinic visit on children who were older than 6 years and had homozygous SS or Sβ° thalassemia. Detailed history, examination, and laboratory tests were done, and transcranial Doppler examinations were obtained in children 2 to 14 years of age. Pulmonary hypertension was defined as pulmonary artery systolic pressure of at least 30 mmHg corresponding to a peak tricuspid regurgitant jet velocity of ≥2.5 m/second. Mild pulmonary hypertension was defined as tricuspid regurgitant jet velocity ≥2.5 to 2.9 m/second. Moderate pulmonary hypertension was defined as tricuspid regurgitant jet velocity ≥3 m/second. Patients with pulmonary stenosis or right outflow obstruction were excluded. Characteristics were compared between patients with mild, moderate, and no pulmonary hypertension using 1-way analysis of variance for continuous variable and Fisher's exact test for categorical variables.

RESULTS. Of the 75 patients who had homozygous SS/Sβ° thalassemia and were older than 6 years, echocardiograms were obtained for 62 (82.6%). Thirty percent (19 of 62) of patients had elevated tricuspid regurgitant jet velocity ≥2.5 m/second. One third of these patients had tricuspid regurgitant jet velocity ≥3 m/second. All patients with elevated tricuspid regurgitant jet velocity had SS disease. A high reticulocyte count, low oxygen saturation, and a high platelet count were significantly associated with elevated pulmonary artery pressures. There was no difference in age, gender, history of acute chest syndrome, hydroxyurea therapy, chronic blood transfusion, stroke, hemoglobin, and bilirubin between patients with and without elevated pulmonary artery pressures. A total of 47% patients with elevated tricuspid regurgitant jet velocity and 57% without elevated tricuspid regurgitant jet velocity had screening transcranial Doppler examinations. Transcranial Doppler examinations were normal for all patients.

CONCLUSIONS. High pulmonary artery pressures do occur in children with sickle cell disease. Screening by echocardiography can lead to early detection and intervention that may potentially reverse this disease process. There was no correlation between elevated pulmonary artery pressures and abnormal transcranial Doppler examination in our study.
Gymnastics-related Injuries to Children Treated in Emergency Departments in the United States, 1990–2005
Authors: Singh Shubha , Smith Gary A. , Fields Sarah K. , McKenzie Lara B.
Published: April 2008

OBJECTIVE. The objective of this study was to describe the epidemiology of gymnastics-related injuries among children in the United States.

METHODS. A retrospective analysis was conducted of data for children 6 through 17 years of age from the National Electronic Injury Surveillance System of the US Consumer Product Safety Commission for 1990 through 2005. Sample weights provided by the National Electronic Injury Surveillance System were used to calculate national estimates of gymnastics-related injuries. Injury rates were calculated for the most frequently occurring types of injury using gymnastics participation data.

RESULTS. An estimated 425900 children 6 through 17 years of age were treated in US hospital emergency departments for gymnastics-related injuries during the 16-year period of 1990–2005. The number of injuries averaged 26600 annually. The number of injuries sustained per 1000 gymnastics participants per year for the pediatric population was 4.8. The number of injuries sustained per 1000 participants per year was greater for the ages 12 to 17 years (7.4) than for the ages 6 to 11 years (3.6). The place where an injury occurred include school (40.0%), a place of recreation or sports (39.7%), home (14.5%), or on other public property (5.8%). The body parts injured were upper extremity (42.3%), lower extremity (33.8%), head/neck (12.9%), trunk (10.4%), and other (0.6%). Injury diagnoses were strain/sprain (44.5%), fracture/dislocation (30.4%), abrasion/contusion (15.6%), laceration/avulsion (3.7%), concussion/closed head injury (1.7%), and other (4.2%). The majority (97.1%) of patients with gymnastics-related injuries were treated and released from the emergency department.

CONCLUSIONS. Gymnastics has one of the highest injury rates of all girls' sports. Establishment of a national database for gymnastics-related injuries, including exposure data for direct calculation of injury rates, would permit better identification and monitoring of risk factors for gymnastics-related injuries and aid in the development, implementation, and evaluation of injury prevention strategies based on epidemiologic evidence.
Effect of a Pediatric Practice-Based Smoking Prevention and Cessation Intervention for Adolescents: A Randomized, Controlled Trial
Authors: Pbert Lori , Flint Alan J. , Fletcher Kenneth E. , Young Martin H. , Druker Susan , DiFranza Joseph R.
Published: April 2008

OBJECTIVE. The purpose of this work was to determine whether a pediatric practice-based smoking prevention and cessation intervention increases abstinence rates among adolescents.

METHODS. Eight pediatric primary care clinics were randomly assigned to either intervention or usual care control condition. The provider- and peer-delivered intervention tested was based on the 5A model recommended by the US Public Health Service clinical practice guidelines and the American Academy of Pediatrics and consisted of brief counseling by the pediatric provider followed by 1 visit and 4 telephone calls by older peer counselors aged 21 to 25 years. A consecutive sample of patients aged 13 to 17 years scheduled for an office visit was eligible regardless of smoking status. Of 2711 patients who agreed to participate, 2709 completed baseline assessments, and 2700 (99.6%) and 2690 (99.2%) completed 6- and 12-month assessments, respectively.

RESULTS. Compared with the usual care condition, nonsmokers who received the provider- and peer-delivered intervention were significantly more likely to self-report having remained abstinent at 6-month and 12-month follow-up; smokers who received the provider- and peer-delivered intervention were more likely to report having quit at the 6-month but not the 12-month follow-up. A number of adolescent characteristics (eg, age, peer smoking, tobacco dependence, and susceptibility) were found to be predictive of abstinence at follow-up.

CONCLUSIONS. A pediatric practice-based intervention delivered by pediatric providers and older peer counselors proved feasible and effective in discouraging the initiation of smoking among nonsmoking adolescents for 1 year and in increasing abstinence rates among smokers for 6 months.