bluuebunny/crossref_metadata_2025 huggingface dataset:
Endothelin-1 Promotes Myofibroblast Induction through the ETA Receptor via a rac/Phosphoinositide 3-Kinase/Akt-dependent Pathway and Is Essential for the Enhanced Contractile Phenotype of Fibrotic Fibroblasts
Authors: Shi-Wen Xu , Chen Yunliang , Denton Christopher P. , Eastwood Mark , Renzoni Elisabetta A. , Bou-Gharios George , Pearson Jeremy D. , Dashwood Michael , du Bois Roland M. , Black Carol M. , Leask Andrew , Abraham David J
Published: March 2004

The endothelins are a family of endothelium-derived peptides that possess a variety of functions, including vasoconstriction. Endothelin-1 (ET-1) is up-regulated during tissue repair and promotes myofibroblast contraction and migration, hence contributing to matrix remodeling during tissue repair. Here, we show that addition of ET-1 to normal lung fibroblasts induces expression of proteins that contribute to a contractile phenotype, including α-smooth muscle actin (α-SMA), ezrin, moesin, and paxillin. We confirm that ET-1 enhances the ability of lung fibroblasts to contract extracellular matrix, a function essential for tissue repair, through induction of de novo protein synthesis. Blockade of the Akt/phosphoinositide 3-kinase (PI3-kinase) pathway with LY294002 and wortmannin prevents the ability of ET-1 to induce α-SMA, ezrin, paxillin, and moesin and to promote matrix contraction. Dominant negative rac and Akt blocked the ability of ET-1 to promote formation of α-SMA stress fibers. Using specific ET-1 receptor inhibitors, we show that ET-1 induces collagen matrix contraction through the ETA, but not the ETB, receptor. Relative to normal pulmonary fibroblasts, fibroblasts cultured from scars of patients with the fibrotic disease systemic sclerosis (scleroderma) show enhanced ET-1 expression and binding. Systemic sclerosis lung fibroblasts show increased ability to contract a collagen matrix and elevated expression of the procontractile proteins α-SMA, ezrin, paxillin, and moesin, which are greatly reduced by antagonizing endogenous ET-1 signaling. Thus, blocking ET-1 or the PI3-kinase/Akt cascades might be beneficial in reducing scar formation in pulmonary fibrosis.
The Mitochondrial Message-specific mRNA Protectors Cbp1 and Pet309 Are Associated in a High-Molecular Weight Complex
Authors: Krause Kirsten , Lopes de Souza Renata , Roberts Douglas G.W. , Dieckmann Carol L.
Published: March 2004

In Saccharomyces cerevisiae, the nuclear-encoded protein Cbp1 promotes stability and translation of mitochondrial cytochrome b transcripts through interaction with the 5′ untranslated region. Fusion of a biotin binding peptide tag to the C terminus of Cbp1 has now allowed detection in mitochondrial extracts by using peroxidase-coupled avidin. Cbp1 is associated with the mitochondrial membranes when high ionic strength extraction conditions are used. However, the protein is easily solubilized by omitting salt from the extraction buffer, which suggests Cbp1 is loosely associated with the membrane through weak hydrophobic interactions. Gel filtration analysis and blue native PAGE showed that Cbp1 is part of a single 900,000-Da complex. The complex was purified using the biotin tag and a sequence-specific protease cleavage site. In addition to Cbp1, the complex contains several polypeptides of molecular weights between 113 and 40 kDa. Among these, we identified another message-specific factor, Pet309, which promotes the stability and translation of mitochondrial cytochrome oxidase subunit I mRNA. A hypothesis is presented in which the Cbp1–Pet309 complex contains several message-specific RNA binding proteins and links transcription to translation of the mRNAs at the membrane.
Performance of an iterated T-HMM for homology detection
Authors: Qian Bin , Goldstein Richard A.
Published: March 2004

Motivation: Much information about new protein sequences is derived from identifying homologous proteins. Such tasks are difficult when the evolutionary relationships are distant. Some modern methods achieve better results by building a model of a set of related sequences, and then identifying new proteins that fit the model. A further advance was the development of iterative methods that refine the model as more homologs are discovered. These methods are generally limited by ad hoc methods of sequence weighting, neglect of underlying evolutionary relationships and the representation of the set with a single one-size-fits-all model. These limitations are avoided through the use of a Tree hidden Markov model (T-HMM) approach. Our previous work described how a non-iterative version of the T-HMM method could identify distant homologs with superior performance compared with other non-iterated approaches, and described how this method was particularly appropriate for being implemented as an iterative algorithm.

Results: We describe an iterative version of the T-HMM algorithm, and evaluate its performance for the detection of distant homologs. Significant improvement over other commonly used methods is found.

Availability: The software (C++, Perl) is available from the corresponding author.
Exploiting the kernel trick to correlate fragment ions for peptide identification via tandem mass spectrometry
Authors: Fu Yan , Yang Qiang , Sun Ruixiang , Li Dequan , Zeng Rong , Ling Charles X. , Gao Wen
Published: March 2004

Motivation: The correlation among fragment ions in a tandem mass spectrum is crucial in reducing stochastic mismatches for peptide identification by database searching. Until now, an efficient scoring algorithm that considers the correlative information in a tunable and comprehensive manner has been lacking.

Results: This paper provides a promising approach to utilizing the correlative information for improving the peptide identification accuracy. The kernel trick, rooted in the statistical learning theory, is exploited to address this issue with low computational effort. The common scoring method, the tandem mass spectral dot product (SDP), is extended to the kernel SDP (KSDP). Experiments on a dataset reported previously demonstrate the effectiveness of the KSDP. The implementation on consecutive fragments shows a decrease of 10% in the error rate compared with the SDP. Our software tool, pFind, using a simple scoring function based on the KSDP, outperforms two SDP-based software tools, SEQUEST and Sonar MS/MS, in terms of identification accuracy.

Supplementary Information:  http://www.jdl.ac.cn/user/yfu/pfind/index.html
Bayesian hierarchical error model for analysis of gene expression data
Authors: Cho HyungJun , Lee Jae K.
Published: March 2004

Motivation: Analysis of genome-wide microarray data requires the estimation of a large number of genetic parameters for individual genes and their interaction expression patterns under multiple biological conditions. The sources of microarray error variability comprises various biological and experimental factors, such as biological and individual replication, sample preparation, hybridization and image processing. Moreover, the same gene often shows quite heterogeneous error variability under different biological and experimental conditions, which must be estimated separately for evaluating the statistical significance of differential expression patterns. Widely used linear modeling approaches are limited because they do not allow simultaneous modeling and inference on the large number of these genetic parameters and heterogeneous error components on different genes, different biological and experimental conditions, and varying intensity ranges in microarray data.

Results: We propose a Bayesian hierarchical error model (HEM) to overcome the above restrictions. HEM accounts for heterogeneous error variability in an oligonucleotide microarray experiment. The error variability is decomposed into two components (experimental and biological errors) when both biological and experimental replicates are available. Our HEM inference is based on Markov chain Monte Carlo to estimate a large number of parameters from a single-likelihood function for all genes. An F-like summary statistic is proposed to identify differentially expressed genes under multiple conditions based on the HEM estimation. The performance of HEM and its F-like statistic was examined with simulated data and two published microarray datasets—primate brain data and mouse B-cell development data. HEM was also compared with ANOVA using simulated data.

Availability: The software for the HEM is available from the authors upon request.
The DISOPRED server for the prediction of protein disorder
Authors: Ward Jonathan J. , McGuffin Liam J. , Bryson Kevin , Buxton Bernard F. , Jones David T.
Published: March 2004

Summary: Dynamically disordered regions appear to be relatively abundant in eukaryotic proteomes. The DISOPRED server allows users to submit a protein sequence, and returns a probability estimate of each residue in the sequence being disordered. The results are sent in both plain text and graphical formats, and the server can also supply predictions of secondary structure to provide further structural information.

Availability: The server can be accessed by non-commercial users at http://bioinf.cs.ucl.ac.uk/disopred/
Prognostic Value of Resection Margins in Supracricoid Laryngectomy
Authors: Gallo Andrea , Manciocco Valentina , Tropiano Maria Luisa , Simonelli Marilia , Marvaso Vincenzo , D'Arcangelo Enzo , de Vincentiis Marco
Published: March 2004

ObjectivesThe objective was to assess the prognostic value of surgical margin involvement in patients treated for squamous cell carcinoma of the larynx.

Study DesignRetrospective study.

MethodsA review was made of 253 patients treated with supracricoid laryngectomy between 1984 and 2001. A histopathological study on the surgical resection margins was performed in all cases. The incidence of local recurrence was correlated with the histological features of resection margins.

ResultsForty patients (15.8%) were identified as having positive margins: 29 had invasive carcinoma and 11 had dysplastic lesions. The remaining 213 patients (84.2%) had negative margins. Subsequent follow‐up showed that 19 of 253 patients developed local recurrence and 3 patients developed regional recurrence. Nine of these patients had positive resection margins (six with invasive carcinoma and three with dysplastic lesions), and 10 had negative resection margins. Overall survival at 3 years was significantly higher for patients without recurrence than for patients with local or regional failure (89.9% vs. 45.5% [P< .05]).

ConclusionAccording to results of the study, patients with positive resection margins developed local recurrence more frequently than those with clear resection margins (P< .05).
Reconstruction of Anterior Nasal Septum: Back‐to‐Back Autogenous Ear Cartilage Graft
Authors: Pirsig Wolfgang , Kern Eugene B. , Verse Thomas
Published: March 2004

Objectives/Hypothesis The ideal material for reconstructing the nasal septum in the deficient nose has not been found. Since 1986, the authors have used autogenous cartilage from the cavum conchae to successfully correct the anterior septum and the associated cartilaginous saddle. The long‐term results in 26 patients with a destroyed septum and a saddle nose are reported.

Study Design Retrospective study.

Methods The mean age of the patients at surgery was 40.2 years, and the mean number of previous nasal procedures was 1.6. Because 11 patients had septal perforations and insufficient septal cartilage or bone, ear cartilage grafts from the cavum conchae were harvested through an anterolateral approach. A special incision was used to divide the concave ear cartilage while preserving the posterior perichondrium. This produced a stable, balanced back‐to‐back graft. The graft was 2.5 to 3 cm long, long enough to allow reconstruction of the anterior septum and to correct part of the saddle nose deformity. The rest of the conchal cartilage was used to fill the remaining cartilaginous saddle. Follow‐up investigations included photographs and visual analogue scales of the patients' symptoms and satisfaction.

Results After a mean interval of 36.7 ± 22.3 months, the back‐to‐back grafts showed no macroscopic signs of resorption. Graft position and shape remained intact after transplantation. All noses were adequately projected and mobile. All patients but one were satisfied with the functional and esthetic result. With a score of 4 representing the level of satisfaction as “very good,” the mean score of the patients was 3.2 ± 0.79. The saddle of the nose completely disappeared in 65.4% of patients, was minimally visible in 23.1%, and was slightly present in 11.5%. Nasal breathing improved considerably in 21 patients, remained the same in 4 patients, and worsened in 1 patient. The mean score of all patients for nasal breathing was 7.3 ± 1.87 on a visual analogue scale of 0 to 10, with 10 representing satisfaction as “very good”.

Conclusion The back‐to‐back autogenous ear cartilage graft is a viable, stable, and balanced graft for functional and aesthetic reconstruction of the anterior nasal septum and cartilaginous saddle deformity in patients with a severely traumatized and deficient septum.
Vascular Leiomyoma of the Head and Neck
Authors: Wang Cheng‐Ping , Chang Yih‐Leong , Sheen Tzung‐Shiahn
Published: March 2004

Objectives/Hypothesis Vascular leiomyoma, a benign tumor composed of smooth muscle cell and vascular endothelium, is rare in the head and neck region. The authors report their experience with 21 patients.

Study Design Retrospective review.

Methods From 1988 to 2001, the clinical records of 21 patients with vascular leiomyoma of the head and neck were reviewed. The pathological material of each tumor was reviewed again for confirmation of the diagnosis and histological classification proposed by Morimoto.

Results Twelve male and 9 female patients were studied. The mean age was 48 years. The locations and numbers of cases of the tumors were as follows: auricle, five; nasal cavity, three; external nose, 3; neck, 3; lip, 3; inner canthus, 2; forehead, 1; and hard palate, 1. All tumors were painless, and most were less than 2 cm in diameter. Three vascular leiomyomas of the neck were larger than 2 cm. Two of the three tumors originating in the nasal cavity presented with nasal obstruction or epistaxis. Regarding histological subtype, 14 of 21 (67%) tumors were solid type; 6 (28%) were cavernous type, and only one (5%) was venous type. Only one tumor (5%) recurred after excision.

Conclusion Vascular leiomyoma usually presents as a small, painless mass. Auricle, nose, lip, and neck are the most common sites of occurrence. Unusually large vascular leiomyomas are developed in the deep space of the neck. Imaging study or cytological examination is not helpful for diagnosis. Histological classification is not necessary. Simple excision yields excellent results.
Location and Timing of Initial Osteoid Deposition in Postmeningitic Labyrinthitis Ossificans Determined by Multiple Fluorescent Labels
Authors: Tinling Steven P. , Colton J. , Brodie Hilary A.
Published: March 2004

Objectives/Hypothesis Variable amounts of fibrosis and neo‐ossification fill the cochlea following bacterial meningitis. The purpose of the study was to delineate the timing and location of initial ossification following pneumococcal meningitis, as well as subsequent remodeling and resorption, over the 3‐month period after infection.

Study Design Randomized, double‐blind study.

Methods Fluorochromes are compounds that specifically incorporate into ossifying bone. Sequential addition of different colored fluorochromes during osteoneogenesis define the timing and location of osteoid deposition and mineralization. Mongolian gerbils were infected by intrathecal injection of Streptococcus pneumoniae type 3, and control gerbils received saline. Both groups were injected with calcein on postoperative day 3, followed by xylenol orange, oxytetracycline, and alizarin red on days 7, 14, and 28 respectively. Ten experimental gerbils were killed 24 hours after each label, and an additional group at 84 days after infection. Two groups of 10 control gerbils were killed at 29 and 84 days after treatment. The temporal bones and tibias were harvested, embedded in plastic, and sliced with a diamond saw. Wafers at a thickness of 200 μm were mounted in sequence and examined.

Results Sixteen of 49 experimental animals (33%) were positive for at least one of the fluorescent labels. Fluorescent labeled osteoid was present at all sampling times. Label extended from the endosteal wall into the lumen of the scala tympani between the vestibule and the round window membrane. Discrete sites of fluorescence varied among specimens and were associated with the opening of the cochlear aqueduct, the scala tympani, organ of Corti, and the stria vascularis and spiral ligament in all turns from base to apex.

Conclusion The results indicate that osteoid is deposited and begins mineralization by day 3 after infection, at least, and continues, at least, through the first 28 days after infection. There was no apparent resorption of new bone and remodeling by 84 days after infection.
Perioperative Parathyroid Hormone Levels in Thyroid Surgery: Preliminary Report
Authors: Warren Frank M. , Andersen Peter E. , Wax Mark K. , Cohen James I.
Published: March 2004

Objectives/Hypothesis An immediate method of accurately predicting postoperative hypocalcemia after total thyroidectomy would allow for selective early discharge of patients at low risk. The objective of the study was to determine the utility of perioperative parathyroid hormone measurement in predicting postoperative hypocalcemia after a thyroid surgery that places total parathyroid function at risk.

Study Design Prospective case series.

Methods Twenty‐seven patients undergoing total or completion thyroidectomy had three blood samples drawn for parathyroid hormone measurement before dissection, 10 minutes after specimen removal, and in the recovery room. Serial ionized calcium levels were measured in the postoperative period. Preoperative, postresection, and recovery room levels were compared with postoperative ionized calcium levels.

Results The average values before resection, after resection, and in the recovery room were 69.3 (range, 13–163), 42.3 (range, 0–120), and 37.4 (range 7–79) pg/mL, respectively. The incidence of hypocalcemia was 11% (3 of 27 patients). The rate of hypocalcemia was significantly higher (50%) in patients with recovery room parathyroid hormone values of 10 pg/mL or less relative to patients with recovery room parathyroid hormone values greater than 10 pg/mL (4%) in this setting (P = .01). Among patients with a parathyroid hormone value of less than 15 pg/mL in the recovery room, an increasing parathyroid hormone level in the recovery room relative to the level after resection predicted normocalcemia without calcium supplementation on χ2 analysis (P = .01).

Conclusion The study demonstrated that perioperative parathyroid hormone values can help predict patients who are at highest risk for postoperative hypocalcemia after thyroid surgery.
Hormonal and Antihormonal Therapy for Epistaxis in Hereditary Hemorrhagic Telangiectasia
Authors: Jameson John J. , Cave David R.
Published: March 2004

Objectives/Hypothesis Objectives were to assess available information on hormonal therapy for bleeding in hereditary hemorrhagic telangiectasia (HHT), to determine whether there is a role for hormonal therapy as an initial therapeutic option, and to report the second known case of response in HHT to antihormonal therapy. Study Design: Literature review and case report.

Methods The literature on hormonal and antihormonal therapy for HHT was reviewed. Medical records for the case reported in the present study were evaluated to confirm the diagnosis and assess responses to surgical and nonsurgical treatments.

Results All reports of success using hormonal therapy for HHT‐related bleeding were either retrospective or uncontrolled with the exception of two. Anecdotal evidence with high‐dose estrogen appeared to show success, but serious side effects have discouraged use. One controlled trial found no benefit for intermediate dose, single‐agent estrogen. The other controlled trial appeared to show benefit with low‐dose estrogen‐progesterone in HHT with gastrointestinal tract bleeding and was supported by an uncontrolled study showing efficacy in epistaxis. The case reported in the present study demonstrated long‐term cessation of epistaxis with tamoxifen in a postmenopausal woman.

Conclusions Systemic estrogen‐progesterone at doses used for oral contraception may eliminate bleeding in symptomatic HHT and is a reasonable initial option in fertile women. There is no information on possible effects of lower‐dose estrogen‐progesterone used in postmenopausal women for hormone replacement therapy. Tamoxifen has dramatically eliminated HHT‐related bleeding in two cases. It is well tolerated in postmenopausal women and should be considered for randomized clinical trials.
Origin of Nasal Polyps: An Endoscopic Autopsy Study
Authors: Larsen Per L. , Tos Mirko
Published: March 2004

Objectives/HypothesisTo further elucidate the natural history, etiology, and pathogenesis of nasal polyps, the present study of their anatomical site of origin was undertaken. The possibility for preferred areas or certain patterns in the places of origin was also considered.

Study DesignAutopsies were examined consecutively.

MethodsEndoscopic examination of the nasal cavity and paranasal sinuses, including endoscopic sinus surgery, was performed in 69 autopsies. The place of origin and attachment of each polyp was meticulously described. Polyps were photographically documented in situ and removed, together with the corresponding mucosa, for later histological examination. The cause of death of the patients was either cardiopulmonary disease or malignant diseases. Median age was 73 years (age range, 47–94 y).

ResultsNasal polyps were found in 22 of the 69 autopsies, corresponding to a frequency of 32%. In all, 54 polyps were found. Thirty‐nine polyps were small (length, 2–5 mm), 10 were medium‐sized, and 5 were large. No complaints of symptoms from the nasal polyps were registered. Most of the polyps (40 of 54 [74%]) originated in relation to sinus outlets. Most of these (34 of 54 [63%]) were found in the middle or superior meatus (13 of 54 [24%]).

ConclusionThe results seemed to indicate that the frequency of nasal polyps is high and that most of the polyps originate from the mucosa of the ostia, clefts, and recesses in the ostiomeatal complex where the initial stage of sinonasal polyposis seems to take place. Continuous postmortem studies in autopsy materials and systematic endoscopic examinations for “silent,” asymptomatic nasal polyps in various groups of patients will lead to a better understanding of the natural history of nasal polyps.
Prevalence of Olfactory Dysfunction: The Skövde Population‐Based Study
Authors: Brämerson Annika , Johansson Leif , Ek Lars , Nordin Steven , Bende Mats
Published: March 2004

Objectives/Hypothesis Patients with olfactory dysfunction appear repeatedly in ear, nose, and throat practices, but the prevalence of such problems in the general adult population is not known. Therefore, the objectives were to investigate the prevalence of olfactory dysfunction in an adult Swedish population and to relate dysfunction to age, gender, diabetes mellitus, nasal polyps, and smoking habits.

Study Design Cross‐sectional, population‐based epidemiological study.

Methods A random sample of 1900 adult inhabitants, who were stratified for age and gender, was drawn from the municipal population register of Skövde, Sweden. Subjects were called to clinical visits that included questions about olfaction, diabetes, and smoking habits. Examination was performed with a smell identification test and nasal endoscopy.

Results In all, 1387 volunteers (73% of the sample) were investigated. The overall prevalence of olfactory dysfunction was 19.1%, composed of 13.3% with hyposmia and 5.8% with anosmia. A logistic regression analysis showed a significant relationship between impaired olfaction and aging, male gender, and nasal polyps, but not diabetes or smoking. In an analysis of a group composed entirely of individuals with anosmia, diabetes mellitus and nasal polyps were found to be risk factors, and gender and smoking were not.

Conclusion The sample size of the population‐based study was adequate, with a good fit to the entire population, which suggests that it was representative for the Swedish population. Prevalence data for various types of olfactory dysfunction could be given with reasonable precision, and suggested risk factors analyzed. The lack of a statistically significant relationship between olfactory dysfunction and smoking may be controversial.
Bacterial Infection After Endoscopic Sinus Surgery: A Controlled Prospective Study
Authors: Bhattacharyya Neil , Gopal Harsha V. , Lee Kun Hee
Published: March 2004

Objectives/Hypothesis The objective was to determine whether infections occurring after endoscopic sinus surgery represent overgrowth of sinonasal flora versus de novo bacterial infection.

Study Design Prospective controlled cohort study.

Methods A cohort of adult patients was prospectively followed after endoscopic sinus surgery. Baseline postoperative control cultures of the ethmoid sinus were obtained. Patients with acute infectious exacerbations of chronic rhinosinusitis had endoscopic culture, and these results were compared with baseline culture data.

Results One hundred thirteen patients were followed for a mean period of 14.5 months after endoscopic sinus surgery. Baseline postoperative culture data revealed that the ethmoid labyrinth was sterile in 23% of cases, carried oral flora in 18% of cases, and was colonized in 60% of cases. Gram‐positive cocci, particularly staphylococcal species, were the most common colonizing organisms (41% of cases). Twenty acute exacerbations were cultured in 17 patients during the follow‐up period. All infectious cultures recovered bacteria; one culture recovered only oral flora. Gram‐positive cocci predominated (56% of isolates) with Staphylococcus aureus being the most common isolate (28%). Of the 36 isolates, only 9 isolates (25%) corresponded to bacteria identified at the time of baseline culture.

Conclusion Although the postoperative sinonasal cavity may be colonized by bacteria after endoscopic sinus surgery, infections arising postoperatively most commonly represent de novo infections by bacteria other than colonizing bacteria. Empirical therapy based on baseline data may be misleading; acute exacerbations of chronic rhinosinusitis after endoscopic sinus surgery should be cultured to guide optimal antibiotic therapy.
Management of Descending Necrotizing Mediastinitis
Authors: Makeieff Marc , Gresillon Nicolas , Berthet Jean Philippe , Garrel Renaud , Crampette Louis , Marty‐Ane Charles , Guerrier Bernard
Published: March 2004

Objective/Hypothesis Descending necrotizing mediastinitis is caused by downward spread of neck infections and constitutes a highly lethal complication of oropharyngeal lesions. This infection previously had a much worse prognosis. In recent years, more aggressive management has been recommended. The aim of this study is to evaluate the results with the association of thoracotomy and cervicotomy, medical care in an intensive care unit, and daily washing of drained cervical and thoracic tissues.

Study Design Retrospective study of 17 patients treated from 1984 to 1998.

Method Descending necrotizing mediastinitis was consecutive to pharyngitis (6 cases), peritonsillar abscess (3 cases), dental abscess (6 cases), foreign body infection (1 case), and laryngitis (1 case). Corticotherapy was reported in seven cases. Twelve patients had no particular medical history. Mean age was 42 years. Mean duration of signs before diagnosis was 6 days. Thoracotomy was associated with the cervical approach in 14 cases, whereas 3 patients were treated by cervicotomy only.

Results Fourteen patients of 17 (82.3%) were successfully treated. Three deaths occurred. The mean duration of hospitalization in the intensive care unit was 30 days, and the mean total duration of hospitalization was 45 days.

Conclusion Descending necrotizing mediastinitis must be detected as soon as possible by computed tomography (CT) scanning in patients with persistent symptomatologia after treatment for oropharyngeal infections. Prompt surgical drainage with thoracotomy and cervicotomy in all cases of mediastinal involvement below the tracheal carena, use of CT scanning to monitor the disease evolution, and medical management in an intensive care unit significantly reduces the mortality rate to less than 20%.
Generalization in Place Learning and Geometry Knowledge in Rats
Authors: Tommasi Luca , Thinus-Blanc Catherine
Published: March 2004

Rats were trained to search for a food reward hidden under sawdust in the
center of a square-shaped enclosure designed to force orientation on the basis
of the overall geometry of the environment. They were then tested in a number
of enclosures differing in shape and in size (rectangular-, double-side
square-, and equilateral triangle-shaped enclosures). Results showed that rats
transferred their place-finding ability to the novel enclosures. Our results
add evidence to the hypothesis that the evolutionary roots of spatial
cognition entail a primitive encoding of geometric relationships, as already
shown using other tasks in rats.
Learning During Stressful Times
Authors: Shors Tracey J.
Published: March 2004

Stressful life events can have profound effects on our cognitive and motor abilities, from those that could be construed as adaptive to those not so. In this review, I discuss the general notion that acute stressful experience necessarily impairs our abilities to learn and remember. The effects of stress on operant conditioning, that is, learned helplessness, as well as those on classical conditioning procedures are discussed in the context of performance and adaptation. Studies indicating sex differences in learning during stressful times are discussed, as are those attributing different responses to the existence of multiple memory systems and nonlinear relationships. The intent of this review is to highlight the apparent plasticity of the stress response, how it might have evolved to affect both performance and learning processes, and the potential problems with interpreting stress effects on learning as either good or bad. An appreciation for its plasticity may provide new avenues for investigating its underlying neuronal mechanisms.
ERK1/2 Activation Is Necessary for BDNF to Increase Dendritic Spine Density in Hippocampal CA1 Pyramidal Neurons
Authors: Alonso Mariana , Medina Jorge H. , Pozzo-Miller Lucas
Published: March 2004

Brain-derived neurotrophic factor (BDNF) is a potent modulator of synaptic
transmission and plasticity in the CNS, acting both pre- and postsynaptically.
We demonstrated recently that BDNF/TrkB signaling increases dendritic spine
density in hippocampal CA1 pyramidal neurons. Here, we tested whether
activation of the prominent ERK (MAPK) signaling pathway was responsible for
BDNF's effects on spine growth. Slice cultures were transfected with enhanced
yellow fluorescent protein (eYFP) by particle-mediated gene transfer, and CA1
pyramidal neurons were imaged by laser-scanning confocal microscopy. We
confirmed that BDNF (24 h) increases spine density in apical dendrites of CA1
neurons. The MEK (ERK kinase) inhibitors PD98059 and U0126 completely
prevented the increase in spine density induced by BDNF, without having an
effect on spine density by themselves. In contrast to its actions on cortical
pyramidal neurons, BDNF had minor and rather localized effects on dendritic
complexity in hippocampal pyramidal neurons, increasing the total length, but
not the branching of apical dendrites within CA1 stratum radiatum,
without affecting basal dendrites in stratum oriens. Our results
support the hypothesis that the ERK-signaling pathway not only mediates
long-term synaptic plasticity and hippocampal-dependent learning, but it is
also involved in the structural remodeling of excitatory spine synapses
triggered by neurotrophins.
Analysing knowledge requirements: a case study
Authors: Schwikkard D.B. , du Toit A.S.A.
Published: March 2004

This paper presents the findings of a knowledge audit conducted to determine the knowledge requirements of a large service‐based enterprise in South Africa. The objective of the knowledge audit was to identify and describe the current and future knowledge requirements of the enterprise. The results indicated that employees have some basic knowledge and information needs that must be satisfied before any further investigations take place. Once the fundamental building blocks of knowledge content are established, it is recommended that more sophisticated solutions can be developed. Broad recommendations for establishing a knowledge management strategy that will be a source of sustainable competitive advantage are proposed.
Elicitation purposes and tasks during mediated information search
Authors: Spink Amanda , Sollenberger Michelle
Published: March 2004

This paper provides an empirical characterization of elicitation purposes related to search tasks during mediated information retrieval. During retrieval, a human search intermediary consults with an information seeker about their information problem, and then conducts a search on the elicited topic, both elicit information from each other during the mediated search process. Elicitations during 30 mediated IR searches were examined. A total of 1,241 search intermediary elicitations within 17 IR elicitation categories and 485 information seeker elicitations within ten IR elicitations categories were identified. The paper provides an enhanced IR task model, including sub tasks, derived from our empirical findings. The implications of the findings are discussed.
Query exhaustivity, relevance feedback and search success in automatic and interactive query expansion
Authors: Vakkari Pertti , Jones Susan , MacFarlane Andy , Sormunen Eero
Published: March 2004

This study explored how the expression of search facets and relevance feedback (RF) by users was related to search success in interactive and automatic query expansion in the course of the search process. Search success was measured both in the number of relevant documents retrieved, whether identified by users or not. Research design consisted of 26 users searching for four TREC topics in Okapi IR system, half of the searchers using interactive and half automatic query expansion based on RF. The search logs were recorded, and the users filled in questionnaires for each topic concerning various features of searching. The results showed that the exhaustivity of the query was the most significant predictor of search success. Interactive expansion led to better search success than automatic expansion if all retrieved relevant items were counted, but there was no difference between the methods if only those items recognised relevant by users were observed. The analysis showed that the difference was facilitated by the liberal relevance criterion used in TREC not favouring highly relevant documents in evaluation.
Dancing with entropy: form attributes, children, and representation
Authors: Kearns Jodi , O'Connor Brian
Published: March 2004

This study explores the use of the information theory entropy equation in representations of videos for children. The calculated rates of information in the videos are calibrated to the corresponding perceived rates of information as elicited from the 12 seven‐ to ten‐year‐old girls who were shown video documents. Entropy measures are calculated for several video elements: set time, set incidence, verbal time, verbal incidence, set constraint, nonverbal dependence, and character appearance. As hypothesized, mechanically calculated entropy measure (CEM) was found to be sufficiently similar to perceived entropy measure (PEM) made by children so that they can be used as useful and predictive elements of representations of children's videos. The relationships between the CEM and the PEM show that CEM could stand for PEM in order to enrich representations for video documents for this age group.
Constraints management
Authors: Boyd Lynn , Gupta Mahesh
Published: March 2004

A number of attempts have been made to develop theories in operations management (OM) (e.g. trade‐off theory by Skinner, customer‐contact model by Chase and Tansik, product‐process matrix by Hayes and Wheelwright). Researchers in OM acknowledge that there is no widely‐accepted theory on which OM rests or which serves as a unified OM theory to integrate existing theory‐like principles or informal theories. Constraints management (CM) has been developed over the past 20 years by consultants and practitioners but has received little attention from OM researchers. The authors believe that constraints management may serve as a broad theory within operations that will allow integration of a great deal of existing OM research. The main objectives of this paper are to propose a construct, throughput orientation, discuss its core dimensions, and develop a theoretical model of CM. The paper also suggests several hypotheses that might be empirically tested to establish CM as a recognized theory in the field of operations management. The paper concludes with suggestions for future research.
Linking environmental scanning to total quality management through business planning
Authors: Temtime Z.T.
Published: March 2004

This paper investigates the relationship between scanning and planning, planning and TQM practices, and scanning and TQM practices by collecting primary data from 54 small and medium‐sized enterprises (SMEs) through questionnaire in the Republic of Botswana. Being explanatory in nature, the study used only descriptive statistics to analyze the data and indicate the nature and direction of the relationship. The study found a statistically significant relationship between scanning and planning; and between planning and TQM practices. However, scanning is indirectly related to TQM and has a moderating impact on TQM practices. Important implications of the findings for practitioners, future research and SME support agencies are also provided.
Developing optimism to improve performance: an approach for the manufacturing sector
Authors: Green Kenneth W. , Medlin Bobby , Whitten Dwayne
Published: March 2004

An organizational optimism model is developed and tested. The constructs of optimism subculture and goal setting process are investigated as antecedents to the level of employee optimism and individual and organizational performance are investigated as direct and indirect consequences of the level of employee optimism. Data relating to the constructs were collected from 133 manufacturers and subjected to structural equation modeling analysis. The proposed model fits the data well. Results indicate that managers may improve individual and organizational performance by raising levels of employee optimism and that levels of optimism may be raised through development of an optimism subculture and implementation of a goal setting process.
Searching advertising placement in cyberspace
Authors: Chuang Ta‐Tao , Pete Chong P.
Published: March 2004

The effective placement of ads is important, especially those placed on the World Wide Web. As a supplement to existing measure of visit count, proposes the use of “exposure” as a means to measure the effectiveness of the Web ad placement. Furthermore, based on the relationship among products placed on the same Web page and the purpose of the ad, proposes an analytical framework and guidelines on whether to make the ad a destination or a control site, in order to maximize the exposure and minimize the competition.
Economic theory as a human tool
Authors: Wellington Donald C.
Published: March 2004

The essay is a short analysis of the place of economic theory in the general social order. There is nothing strange and peculiar about its place. It rather fits in perfectly and is providing an exceptionally useful function in the social order.
Action research reviewed: a market‐oriented approach
Authors: Ballantyne David
Published: March 2004

The purpose of this article is to provide an understanding of the methodology of action research, especially its use in a marketing context. A retrospective account of a market‐oriented action research project in which the author was involved is provided in the form of a summative evaluation of the methodology used. The status of research claims for action research in scholarly publications is discussed and found to be problematic. A hermeneutic case research pathway is recommended as a solution. Links between action research as methodology and internal marketing as strategy are made. A conclusion is reached that the basis of market‐oriented action research is “knowledge renewal”. This is achieved through an iterative process of action and learning, facilitated by the relationships formed between those involved.
Action research in turbulent environments
Authors: Daniel Elizabeth , Wilson Hugh N.
Published: March 2004

Planning tools originating from logical rational models of strategy formation still have their place in e‐commerce, albeit complemented with elements of incrementalism and vision. Tools for prioritisation specifically, though, are unvalidated in this sphere. Action research would seem to be well suited to turbulent environments such as e‐commerce, due to its immediacy of outcome, its future orientation, its respect for practitioners as co‐producers of knowledge and its cyclical process. An action research study is described which modifies the directional policy matrix (DPM) to take account of competition between business models, not just between individual organisations. Conclusions are drawn on the wider applicability of the matrix, the role of strategy tools in situations of uncertainty, and the role of action research in reducing the gap between theory and practice.
There can be no learning without action and no action without learning
Authors: McLoughlin Damien
Published: March 2004

The purpose of this paper is to present an example of action learning in marketing – the unique postgraduate programme in marketing called the marketing development programme (MDP). This uniqueness arises in three main ways. First, the MDP is open only to those students with no work experience. Second, it employs action learning as the central pedagogy rather than an add‐on. Finally, it is a rolling programme with overlapping intakes and as such appears to have no beginning and no end. There are two important streams of learning to be harvested from such a programme. First, the MDP has for more than 20 years educated young marketers through affording them the opportunity to learn from marketing action within a supportive learning environment. The second is that there can be no action without learning, that is, the MDP has learned from its experience and created new learning for participants as a result. The paper concludes by considering the implications of the MDP for marketing education, theory and practice.
Managing customer expectations in the service encounter
Authors: Coye Ray W.
Published: March 2004

Consumers of services have expectations about what they will receive from the delivery system. These expectations are beliefs about future events which, when compared with the perceived actual service delivered, are presumed to influence satisfaction and assessments of overall service quality. The purpose of this paper is to propose a model that outlines the process through which expectations operate at the point of delivery and provide a framework for future investigations. Implications for management practice focus on service provider behavior at the point of delivery and on control of cues that may influence consumer expectations once they have entered the delivery system. Directions for research include verification of model relationships and identification of specific types of cues that relate to attributes commonly considered in consumers’ judgements of service quality.
What drives consumers to shop online? A literature review
Authors: Perea y Monsuwé Toñita , Dellaert Benedict G.C. , de Ruyter Ko
Published: March 2004

While a large number of consumers in the US and Europe frequently shop on the Internet, research on what drives consumers to shop online has typically been fragmented. This paper therefore proposes a framework to increase researchers’ understanding of consumers’ attitudes toward online shopping and their intention to shop on the Internet. The framework uses the constructs of the Technology Acceptance Model (TAM) as a basis, extended by exogenous factors and applies it to the online shopping context. The review shows that attitudes toward online shopping and intention to shop online are not only affected by ease of use, usefulness, and enjoyment, but also by exogenous factors like consumer traits, situational factors, product characteristics, previous online shopping experiences, and trust in online shopping.
People and information technology in the supply chain
Authors: Russell Dawn M. , Hoag Anne M.
Published: March 2004

Understanding people and how they factor into complex information technology (IT) implementations is critical to reversing the growing trend of costly IT implementation failures. Accordingly, this article presents an approach to dissecting the social and organizational influences impacting peoples’ acceptance of technology designed to improve business performance. This article applies the diffusion of innovation theoretical framework to understand and analyze IT innovation implementation challenges. The diffusion approach is applied to two recent cases of implementations of IT supply chain innovations at two aerospace firms, both with complex, global, inter‐firm supply chains. Results indicate that several social and organizational factors do affect the implementation's success. Those factors include users’ perceptions of the innovation, the firm's culture, the types of communication channels used to diffuse knowledge of the innovation and various leadership factors.
Positive brand extension trial and choice of parent brand
Authors: Chen Kuang‐Jung , Liu Chu‐Mei
Published: March 2004

This article focuses on the possible relationship between the parent brand and a new brand extension. In particular, the study focuses on the impact of a parent brand on the trial of the extension and the reciprocal effect of a successful trial of new brand extensions positioned horizontally and vertically on the parent brand. Results show positive influence of the parent brand on the trial of the extension. Successful trial also helped the parent brand on a reciprocal basis, particularly among the non‐loyal users and non‐users of the parent brand. Another finding is the moderating effect of category positioning on the magnitude of the reciprocal effect of the brand extension on the parent brand. There is also an indication that prior parent brand experience acts as a moderator of reciprocal effects.
The reciprocal effects of extension quality and fit on parent brand attitude
Authors: Zimmer Mary R. , Bhat Subodh
Published: March 2004

The evidence for the reciprocal effects of a brand extension on its parent brand is unclear. An experiment was conducted to investigate the impact of an extension's quality, its fit with the parent brand, and parent brand dominance, on parent brand evaluation. The paper finds that extension quality and fit did not dilute parent brand attitude; in other words, an extension either left parent brand attitude unchanged or enhanced it moderately. The only effect of brand dominance was that it enhanced parent brand attitude when the extension was a good fit. Further, the introduction of an extension, regardless of its fit or quality, enhanced parent brand attitude for a durable product relative to a control group. It seems that parent brand attitudes are held strongly enough to resist the new information that is associated with a newly introduced brand extension.