bluuebunny/crossref_metadata_2025 huggingface dataset:
Pneumatic transport is critical for leukaemic patients with major leukocytosis: what precautions to measure lactate dehydrogenase, potassium and aspartate aminotransferase?
Authors: Guiheneuf Raphael , Vuillaume Isabelle , Mangalaboyi Jacques , Launay David , Berthon Céline , Maury J-Claude , Maboudou Patrice , Rousseaux Jean
Published: November 2009

False elevations of plasma lactate dehydrogenase (LDH), potassium and aspartate aminotransferase (AST) have been described, in relation to haemolysis, occurring most often by mechanical release during phlebotomy or specimen processing. We present the cases of two leukaemic patients with severe hyperleukocytosis for whom LDH, potassium and AST were dramatically but falsely elevated. This false elevation was not caused by haemolysis but could be related to white cells lysis during transport through a pneumatic transportation system, enhanced by a specific fragility of leukaemic cells. Interestingly, this interference almost completely disappeared when serum rather than plasma was used, or when leukocytosis came back to normal. This work is meant to alert clinicians to the risks of errors in LDH, potassium and AST in leukaemic patients and suggest what precautions to take.
Comparison between transcutaneous bilirubinometry and total serum bilirubin measurements in preterm infants <35 weeks gestation
Authors: Ahmed M , Mostafa S , Fisher G , Reynolds T M
Published: November 2009

Background

Neonatal hyperbilirubinaemia is a common treatable cause of brain injury. The treatment for this condition is phototherapy. The decision whether to use phototherapy is currently dependent upon serum bilirubin assay results. However, repeated blood sampling is not only traumatic but may also be a cause of anaemia in neonates. We evaluated a transcutaneous bilirubin assay method to determine whether it was suitable for routine use in preterm infants.

Methods

One hundred and eighty-three transcutaneous bilirubin measurements were taken contemporaneously with blood samples for laboratory measurement of serum bilirubin. The study was carried out with informed parental consent and approval by the local research ethics committee.

Results

The transcutaneous bilirubin method (Bili Chek®) exhibited a consistent positive bias compared with the laboratory bilirubin assay. Consequently, for a given detection rate, the transcutaneous method had a higher screen positive rate, i.e. more neonates would be given phototherapy if transcutaneous bilirubin results were used to decide. There was a margin of safety in the transcutaneous bilirubin assay calibration.

Conclusion

The BiliChek transcutaneous bilirubin assay is a safe alternative to laboratory bilirubin assay in deciding whether to give preterm neonates phototherapy.
Central pontine myelinolysis secondary to hypokalaemic nephrogenic diabetes insipidus
Authors: Davenport C , Liew A , Vic Lau P , Smith D , Thompson C J , Kearns G , Agha A
Published: November 2009

Central pontine myelinolysis (CPM) has been described in alcoholic patients and in the aftermath of rapid correction of chronic hyponatraemia. We describe a case of CPM occurring secondary to nephrogenic diabetes insipidus (DI), which developed as a consequence of severe hypokalaemia. A 63-year-old man with alcohol dependence was admitted to hospital with severe pulmonary sepsis and type 1 respiratory failure. On admission, he had euvolaemic hyponatraemia of 127 mmol/L, consistent with a syndrome of inappropriate antidiuretic hormone secondary to his pneumonia. Following admission, his plasma potassium dropped from 3.2 to a nadir of 2.3 mmol/L. Mineralocorticoid excess, ectopic adrenocorticotrophic hormone production and other causes of hypokalaemia were excluded. The hypokalaemia provoked significant hypotonic polyuria and a slow rise in plasma sodium to 161 mmol/L over several days. Plasma glucose, calcium and creatinine were normal. The polyuria did not respond to desmopressin, and subsequent correction of his polyuria and hypernatraemia after normalization of plasma potassium confirmed the diagnosis of nephrogenic DI due to hypokalaemia. The patient remained obtunded, and the clinical suspicion of osmotic demyelination was confirmed on magnetic resonance imaging. The patient remained comatose and passed away 10 days later. This is the first reported case of nephrogenic DI resulting in the development of CPM, despite a relatively slow rise in plasma sodium of less than 12 mmol/L/24 h. Coexisting alcohol abuse, hypoxaemia and hypokalaemia may have contributed significantly to the development of CPM in this patient.
Difference between total and intact assays for N-terminal propeptide of type I procollagen reflects degradation of pN-collagen rather than denaturation of intact propeptide
Authors: Koivula Marja-Kaisa , Ruotsalainen Vesa , Björkman Mikko , Nurmenniemi Sini , Ikäheimo Risto , Savolainen Kari , Sorva Antti , Risteli Juha
Published: November 2009

Background

The concentration of N-terminal propeptide of type I procollagen (PINP) in the serum reflects the rate of type I collagen formation. Intact PINP assay measures the trimeric propeptide while total P1NP assay measures both trimeric and monomeric forms. In this study we compared these two assays emphasizing the possible differences.

Methods

Intact and total PINP were measured from serum in healthy Finnish blood donors ( n = 34) and in the patients with chronic renal failure before and after haemodialysis ( n = 39). In addition, the serum of a normal man, pooled hospital serum samples and the serum of a patient with haemodialysis treatment were fractioned by gel filtration and trimeric and monomeric forms were located. Fractions were lyophilized and intact and total PINP were measured in each fraction. Samples from bedridden geriatric patients ( n = 173) were also measured using intact and total PINP assays and a degradation marker of type I collagen (ICTP).

Results

The correlation between intact and total PINP in controls was 0.89 and their PINP concentrations were similar. In haemodialysis or bedridden geriatric patients, the PINP methods gave significantly different results. In gel filtration studies, intact PINP hardly measured monomeric form even if its concentration was disproportionately increased in haemodialysis patients. In bedridden geriatric patients, the difference of total and intact PINP correlated significantly to degradation marker ICTP.

Conclusions

Difference between total and intact assays for PINP seem to reflect degradation of pN-collagen rather than denaturation of intact propeptide.
Biological variation of glycated haemoglobin in a paediatric population and its application to calculation of significant change between results
Authors: Desmeules Philippe , Cousineau Jocelyne , Allard Pierre
Published: November 2009

Background

To determine precisely the probability that a change between two glycated haemoglobin A1c (HbA1c) results is significant and that clinical actions may be required, the biological variation of HbA1c must be known. However, it has not been evaluated in a paediatric population. We therefore determined the long-term biological variation of HbA1c in a paediatric population and used it to generate a probability curve for significant changes between two consecutive HbA1c measurements.

Methods

A group of 24 boys and 14 girls with cystic fibrosis (CF) but without diabetes or impaired glucose tolerance has been selected. HbA1c has been measured at least five times over five consecutive years for all subjects. We have used the Fraser and Harris method to calculate within-subject biological variation (CVI), which allowed the determination of the probability that a change is significant between results.

Results

As within-subject variances are equivalent for girls and boys ( P > 0.1), both genders were merged for biological variation analysis. The CVI calculated for HbA1c was 4.8% and the between-subject variation (CVG) was 12.8%. Then, a probability curve based on the CVI found was generated and showed that a change of 14% between two consecutive HbA1c results corresponding to a probability of 95% was significant.

Conclusions

We determined for the first time the biological variation of HbA1c in a paediatric population, which is higher than the ones found for adult populations. The probability curves generated from these data could be invaluable tools for clinicians to balance HbA1c results with other clinical parameters.
Serum vitamin A and E analysis: comparison of methods between laboratories enrolled in an external quality assurance programme
Authors: Greaves Ronda , Jolly Lisa , Woollard Gerald , Hoad Kirsten
Published: November 2009

Aim

To survey laboratories enrolled in the Royal College of Pathologists of Australasia (RCPA) Chemical Pathology Quality Assurance Programme (QAP) for vitamin A and E testing to determine differences between methods of analysis.

Methods

A detailed questionnaire covering the major aspects of serum vitamin A and E analysis was sent to all participating laboratories in 2007.

Results

Thirteen out of the 22 laboratories completed the questionnaire. Methods between laboratories showed a great deal of commonality. All respondents performed a liquid extraction step, which included the addition of an internal standard, followed by high-performance liquid chromatography (C18 columns with predominantly methanol-based mobile phases) with spectrophotometric detection. Major inter-laboratory differences were whether the sample was protected from light, the extraction solvents and ratios used, the drying down temperature used post-liquid extraction and choice of calibrator.

Conclusions

The questionnaire highlighted discrete methodological differences between laboratories. These findings provide direction to enable the Vitamins Working Party of the Australasian Association of Clinical Biochemists to further investigate the dispersion in results between participants of the RCPA QAP vitamin programme.
Postpartum increase of serum thioredoxin concentrations and the relation to CD8 lymphocytes
Authors: Kuroda Shoko , Watanabe Mikio , Santo Tomoko , Shimizuishi Yu , Takano Toru , Hidaka Yoh , Kimura Tadashi , Iwatani Yoshinori
Published: November 2009

Background

There are few data on oxidative stresses during and after pregnancy, although aggravation of autoimmune disease is implicated in oxidative stress and occurs frequently in the postpartum period. Thioredoxin (TRX) is a stress-inducible protein, and is used as a good biomarker for oxidative stress. To clarify the changes in the levels of oxidative stress during and after pregnancy, we examined serum TRX levels and the numbers of lymphocyte subsets.

Methods

We measured serum TRX levels by enzyme-linked immunosorbent assay (ELISA), and neutrophils, lymphocytes, and CD4 and CD8 lymphocytes by flow cytometry in peripheral blood from 88 healthy pregnant women, 26 just after delivery women, 77 healthy postpartum women and 19 healthy non-pregnant women.

Results

The serum levels of TRX did not change during pregnancy, but increased in four, seven and 10 months postpartum. Serum TRX levels were correlated with the percentages of neutrophils in normal non-pregnant women and women one month postpartum, and with those of CD8 lymphocytes in early pregnant women and women one and four months postpartum.

Conclusions

Oxidative stress increased in the postpartum period, and the levels at one and four months postpartum were related to CD8 lymphocytes.
Differential diagnosis of chylothorax in a patient on parenteral nutrition: a case report
Authors: Vincent Royce P , Barron Jeffrey L , Mulleague Larry
Published: November 2009

Parenteral nutrition (PN) is widely used when enteral feeding is contraindicated or not possible in patients who are malnourished or at risk of malnutrition, but it is not without complications. We describe the rare complication of PN-related chylothorax that can lead to extensive investigations if not picked up early with clinical suspicion and simple biochemical tests.
Glycated albumin levels are higher relative to glycated haemoglobin levels in gastrectomized subjects
Authors: Koga Masafumi , Murai Jun , Saito Hiroshi , Mukai Mikio , Matsumoto Soeko , Kasayama Soji
Published: November 2009

Background

In gastrectomized subjects, oral glucose tolerance test often shows marked hyperglycaemia (oxyhyperglycaemia) after glucose loading. Because serum glycated albumin (GA) has been shown to better reflect postprandial and maximum plasma glucose levels, we investigated whether or not the clinical significance of serum GA and glycated haemoglobin (HbA1C) in non-diabetic gastrectomized subjects differs.

Methods

During health examinations, 62 non-diabetic subjects with a history of gastrectomy and 87 non-diabetic control subjects were selected in the present study. Body mass index (BMI) in the gastrectomy group was significantly lower than in the control group.

Results

Fasting plasma glucose levels were significantly lower in the gastrectomized subjects than in the control subjects. Although both HbA1C and serum GA were significantly higher in the gastrectomized subjects, there was a significant difference in GA/HbA1C ratio between the gastrectomized subjects and the control subjects. BMI-adjusted serum GA, based on our previous finding of inverse influence of BMI on serum GA, was also significantly higher in the gastrectomized subjects than in the controls.

Conclusions

Serum GA is higher relative to HbA1C in gastrectomized subjects. This suggests that serum GA may be a better marker than HbA1C for glycaemic excursion in these subjects.
Non-specific interference in the measurement of plasma ammonia: importance of using a sample blank
Authors: Herrera Daniel Juan , Hutchin Tim , Fullerton Donna , Gray George
Published: November 2009

Background

Enzymatic assays using glutamate dehydrogenase (GLDH) to monitor the transformation of NAD(P)H to NAD(P)+ by a spectrophotometric technique are the most common methods to measure plasma ammonia (PA) in routine laboratories worldwide. However, these assays can potentially be subject to interference by substances in plasma able to oxidize NAD(P)H at a substantial rate, thereby providing falsely high results.

Methods

To study this potential interference, we spiked a plasma pool with a liver homogenate and measured the ammonia concentration using a dry chemistry system (Vitros 250, Ortho Clinical Diagnostic, Raritan, NJ, USA), an enzymatic assay without a sample blanking step (Infinity Ammonia Liquid Stable Reagent, Thermo Fisher Scientific, Waltham, USA) and an enzymatic assay that corrects for the non-specific oxidation of NADPH (Ammonia kit, RANDOX Laboratories Ltd, Crumlin, UK).

Results

This experiment shows that the Infinity™ ammonia reagent kit is subject to a clinically significant interference and explains the discrepancies previously reported between these methods in patients with acute liver failure (ALF).

Conclusion

When using enzymatic methods for the assessment of PA, we recommend including a sample blanking correction and this should be mandatory when monitoring patients with ALF.
Extreme hyperalphalipoproteinaemia in a patient with a solitary paraspinal lipoma
Authors: Musaad Samarina , Robertson Ken , Clarke Michael W , Hooper Amanda J , French Gary , Chiu Weldon , Burnett John R
Published: November 2009

Increased high-density lipoprotein (HDL)-cholesterol (hyperalphalipoproteinaemia; HALP) is commonly genetic, but may have secondary causes. An association between multiple lipomatosis and HALP has been reported; however, the mechanism for this is unclear. We report the case of a 69-year-old Cook Island woman with extreme HALP who presented with a large paraspinal lipoma. Magnetic resonance imaging showed no other lipomas. She had the metabolic syndrome, a family history suggestive of lipomas and was on lipid-lowering and antihypertensive therapy. Her plasma HDL-cholesterol concentration was 4.9 mmol/L (>95th percentile for age and sex) and was not explained by typical secondary causes. HDL2 and HDL3 subfractions were increased, with HDL2 predominance. The excised lipoma histology demonstrated benign tissue and normal karyotype. Postoperative lipid profiles showed no change in HDL-cholesterol concentrations. In summary, we report a case of extreme HALP that persisted after excision of a solitary paraspinal lipoma.
The biochemistry, measurement and current clinical significance of asymmetric dimethylarginine
Authors: Blackwell Scott
Published: November 2009

Asymmetric dimethylarginine (ADMA) is an endogenous competitive inhibitor of nitric oxide synthase and an important cause of endothelial dysfunction. Its increased plasma concentration is associated with a variety of traditional cardiovascular risk factors, and may mediate their effects on the vascular endothelium. ADMA is also an independent predictor of cardiovascular events and mortality, and predicts outcomes in critically ill patients in the intensive care unit. This work has provided insights into the role of ADMA as an endogenous regulator of nitric oxide synthesis. At present there is no specific therapy to modify ADMA concentration, but increasing interest and work on protein arginine methyltransferases and dimethylarginine dimethylaminohydrolase, which synthesize and metabolize ADMA, respectively, might provide novel therapeutic targets.
An intelligent videomonitoring system for fall detection at home: perceptions of elderly people
Authors: Londei Sophie Turgeon , Rousseau Jacqueline , Ducharme Francine , St-Arnaud Alain , Meunier Jean , Saint-Arnaud Jocelyne , Giroux Francine
Published: November 2009

We explored the perception and receptivity of elderly people regarding the introduction of an intelligent videomonitoring system (IVS) at home. Using a mixed methods design, 25 elderly people with a history of falls completed a structured interview (two questionnaires). In the year preceding the interview, 72% of the participants fell as many as seven times. Open-ended questions (qualitative data) were used to supplement the quantitative data. A content analysis (qualitative data) and a descriptive analysis (quantitative data) were carried out. The participants were 84% favourable or partially favourable to technologies which ensured home security and 96% favourable or partially favourable to the IVS. About half (48%) said that they would use it. The other participants did not wish to use it unless they had been left to live alone or if their health condition worsened. Thus the living conditions of the elderly appear to influence their perception and receptivity regarding the acceptance and use of an IVS.
Chronic lymphocytic leukaemia in pregnancy: a case report and literature review
Authors: Maxwell Cynthia , Grady Rosheen , Crump Michael
Published: November 2009

Chronic lymphocytic leukaemia is a rare condition reported in pregnancy. We review a case of a woman presenting for pregnancy care with active disease and review the literature on this condition. This case raises several important issues with regard to managing complex medical diseases such as leukaemia in pregnant women, including the role of multidisciplinary care.
A longitudinal study of the effect of heparin thromboprophylaxis during pregnancy on maternal bone metabolism
Authors: Ogueh O , Johnson M R , Benjamin A
Published: November 2009

The aim of this study was to determine the effect of heparin thromboprophylaxis during pregnancy on maternal biochemical markers of bone metabolism. This was a prospective longitudinal study of carboxy terminal pro-peptide of type I collagen (PICP) and cross-linked carboxyterminal telopeptide of type I collagen (ICTP) levels in 15 women, who had heparin thromboprophylaxis during pregnancy compared with those of 18 normal pregnant controls. During pregnancy, the rate of change of PICP and ICTP in women who had heparin thromboprophylaxis was similar to those of women who did not ( P = 0.184 for PICP, and P = 0.129 for ICTP), and PICP and ICTP levels at individual time points were similar in both groups. Therefore, heparin thromboprophylaxis during pregnancy does not affect maternal biochemical markers of bone metabolism.
Basics in Tension Structures
Authors: Wagner Rosemarie
Published: November 2009

Tensioned structures are made of cable nets, fabrics or foils, the surfaces are plane, singe curved or double curved and are mechanically tensioned or inflated. Depending on the material the design process is different Designers and manufacturer have to know the common properties and differences creating optimized structures for each material and avoiding mistakes and failures. In the following the typical design procedure is pointed out of the different materials, the capability and features of the different materials are shown in examples.
Industrial Design and Analysis of Structural Membranes
Authors: Haug E. , De Kermel P. , Gawenat B. , Michalski A.
Published: November 2009

This overview paper summarizes the status of design and analysis of small and large, complex, flexible and adaptable industrial membrane structures in architecture, automotive and space industries, with the numerical tools developed and implemented by the authors and their affiliations. Examples from aero-space membranes, airbag simulations used by car makers, and from impact biomechanics, enlarge the field of application beyond structural engineering.
Air Supported Membrane Structure Applications for Large-Scale Disaster Response Shelters
Authors: Bell Larry
Published: November 2009

Air-supported membrane structures can potentially offer important and unique advantages as emergency shelters and community service facility applications. Key among these benefit features are that they can be transported to remote locations in small, lightweight packages; they can be rapidly deployed at the site without large construction equipment, special tools or skills; and they can provide spacious, environmentally-protected interior volumes that are versatile and can be adapted for a variety of needs. This paper will present a variety of systems concepts, including an example of a large-scale air-supported membrane structure that is applicable for providing emergency shelter for community groups and support accommodations exceeding capacities of conventional module approaches. This work is part of an ongoing design exploration study that is being undertaken at the University of Houston's Sasakawa International Center for Space Architecture (SICSA).
Virtual Design Methodology for Lightweight Structures — Aerodynamic Response of Membrane Structures
Authors: Michalski A. , Haug E. , Bradatsch J. , Bletzinger K.-U.
Published: November 2009

This paper presents the current application of numerical Fluid-Structure Interaction (FSI) simulation to the architectural and structural design of large umbrella structures and the work on generating atmospheric wind inflow conditions for numerical simulations. This article outlines a virtual design methodology for structures under the impact of fluctuating wind loads and provides results on worked examples
A Monolithic FE Formulation for the Analysis of Membranes in Fluids
Authors: Rossi Riccardo , Ryzhakov Pavel B. , Oñate E.
Published: November 2009

We propose here an efficient approach for treating the interaction between membranes and fluids. Slight compressibility of the fluid is assumed. Classical total Lagrangian formulation including wrinkling is adopted for the membrane representation, whereas fluid is treated in an updated Lagrangian manner, developed in the current work. Assumption of slight compressibility of the fluid enables one to define the monolithic fluid-membrane system in a natural way. The displacements are the primary variables of both the fluid and the membrane domains. The formulation adopts the Particle Finite Element Method (PFEM) philosophy for free-surface identification and mesh regeneration. Three examples illustrate the functionality of the formulation in application to FSI problems involving motion of membranes in water.
Multiple determinants within iron-responsive elements dictate iron regulatory protein binding and regulatory hierarchy
Authors: Goforth Jeremy B. , Anderson Sheila A. , Nizzi Christopher P. , Eisenstein Richard S.
Published: November 2009

Iron regulatory proteins (IRPs) are iron-regulated RNA binding proteins that, along with iron-responsive elements (IREs), control the translation of a diverse set of mRNA with 5′ IRE. Dysregulation of IRP action causes disease with etiology that may reflect differential control of IRE-containing mRNA. IREs are defined by a conserved stem–loop structure including a midstem bulge at C8 and a terminal CAGUGH sequence that forms an AGU pseudo-triloop and N19 bulge. C8 and the pseudo-triloop nucleotides make the majority of the 22 identified bonds with IRP1. We show that IRP1 binds 5′ IREs in a hierarchy extending over a ninefold range of affinities that encompasses changes in IRE binding affinity observed with human L-ferritin IRE mutants. The limits of this IRE binding hierarchy are predicted to arise due to small differences in binding energy (e.g., equivalent to one H-bond). We demonstrate that multiple regions of the IRE stem not predicted to contact IRP1 help establish the binding hierarchy with the sequence and structure of the C8 region displaying a major role. In contrast, base-pairing and stacking in the upper stem region proximal to the terminal loop had a minor role. Unexpectedly, an N20 bulge compensated for the lack of an N19 bulge, suggesting the existence of novel IREs. Taken together, we suggest that a regulatory binding hierarchy is established through the impact of the IRE stem on the strength, not the number, of bonds between C8 or pseudo-triloop nucleotides and IRP1 or through their impact on an induced fit mechanism of binding.
Generalized Diagonal Band Copulas with Two-Sided Generating Densities
Authors: Kotz Samuel , van Dorp Johan René
Published: November 2009

Copulas are joint continuous distributions with uniform marginals and have been proposed to capture probabilistic dependence between random variables. Maximum-entropy copulas introduced by Bedford and Meeuwissen (Bedford, T., A. M. H. Meeuwissen. 1997. Minimally informative distributions with given rank correlations for use in uncertainty analysis. J. Statist. Comput. Simulation 57(1–4) 143–175) provide the option of making minimally informative assumptions given a degree-of-dependence constraint between two random variables. Unfortunately, their distribution functions are not available in a closed form, and their application requires the use of numerical methods. In this paper, we study a subfamily of generalized diagonal band (GDB) copulas, separately introduced by Ferguson (Ferguson, T. F. 1995. A class of symmetric bivariate uniform distributions. Statist. Papers 36(1) 31–40) and Bojarski (Bojarski, J. 2001. A new class of band copulas—Distributions with uniform marginals. Technical report, Institute of Mathematics, Technical University of Zielona Góra, Zielona Góra, Poland). Similar to Archimedean copulas, GDB copula construction requires a generator function. Bojarski's GDB copula generator functions are symmetric probability density functions. In this paper, symmetric members of a two-sided framework of distributions introduced by van Dorp and Kotz (van Dorp, J. R., S. Kotz. 2003. Generalizations of two-sided power distributions and their convolution. Comm. Statist.: Theory and Methods 32(9) 1703–1723) shall be considered. This flexible setup allows for derivations of GDB copula properties resulting in novel convenient expressions. A straightforward elicitation procedure for the GDB copula dependence parameter is proposed. Closed-form expressions for specific examples in the subfamily of GDB copulas are presented, which enhance their transparency and facilitate their application. These examples closely approximate the entropy of maximum-entropy copulas. Application of GDB copulas is illustrated via a value-of-information decision analysis example.
Information Variability Impacts in Auctions
Authors: Jia Justin , Harstad Ronald M. , Rothkopf Michael H.
Published: November 2009

A wide variety of auction models exhibit close relationships between expected revenue and the second-highest order statistic of bidders' expected asset values. Similarly close relationships between the winner's expected profit and the expected difference between the highest and second-highest order statistics of bidders' information are also common. We use stochastic orderings to see when greater environmental variability of bidders' information enhances expected profit and expected revenue.
An Empirical Analysis of Mobile Voice Service and SMS: A Structural Model
Authors: Kim Youngsoo , Telang Rahul , Vogt William B. , Krishnan Ramayya
Published: November 2009

In addition to the wireless telephony boom, a similar exponentially increasing trend in wireless data service—for example, short message service (SMS)—is visible as technology advances. We develop a structural model to examine user demand for voice service and SMS. Specifically, we measure the own- and cross-price elasticities of these services. The cross-price elasticity is of significant importance because marketing activities are critically influenced by whether the goods are substitutes or complements. The research context poses significant econometric challenges due to three-part tariffs and sequential discrete plan choice and continuous quantity choice decisions. Using detailed individual consumption data of more than 6,000 customers, we find that SMS and voice service are small substitutes. A 10% increase in the price of voice minutes will induce about a 0.8% increase in the demand for SMS. The own-price elasticity of voice is also low, to the order of approximately −0.1. Younger users' demand is far more inelastic than that of older users. We then conduct counterfactual policy experiments that fully capture the effects of changes in key parameters on the firm's revenues. Finally, we discuss the generalizability of our framework.
Drivers of Finished-Goods Inventory in the U.S. Automobile Industry
Authors: Cachon Gérard P. , Olivares Marcelo
Published: November 2009

Automobile manufacturers in the U.S. supply chain exhibit significant differences in their days of supply of finished vehicles (average inventory divided by average daily sales rate). For example, from 1995 to 2004, Toyota consistently carried approximately 30 fewer days of supply than General Motors. This suggests that Toyota's well-documented advantage in manufacturing efficiency, product design, and upstream supply chain management extends to their finished-goods inventory in their downstream supply chain from their assembly plants to their dealerships. Our objective in this research is to measure for this industry the effect of several factors on inventory holdings. We find that two factors, the number of dealerships in a manufacturer's distribution network and a manufacturer's production flexibility, explain essentially all of the difference in finished-goods inventory between Toyota and three other manufacturers: Chrysler, Ford, and General Motors.
Managing Know-How
Authors: Lee Deishin , Van den Steen Eric
Published: November 2009

We study how firms can use a knowledge management system to optimally leverage employee-generated know-how. In particular, we consider the following practical strategic questions for the manager of a knowledge-intensive firm: Should her firm develop a formal knowledge system? And if so, how should it be managed, particularly in terms of what information to record? We find that firms benefit more from a knowledge system when they are larger, face the same issues more frequently, have higher turnover, and face problems about which there is less general knowledge. In terms of what information to record, a key insight is that recording moderately successful practices can be counterproductive, because doing so may inefficiently reduce employees' incentives to experiment. This “strong-form competency trap” forces firms into an exploration–exploitation trade-off. Firms that value a knowledge system most should also be most selective in recording information. We further find that recording successes is more valuable than recording failures, which supports firms' focus on best practice. Beyond these main principles, we also show that it may be optimal to disseminate know-how on a plant level but not on a firm level, and that recording backup solutions is most valuable at medium levels of environmental change.
Cross-Function and Same-Function Alliances: How Does Alliance Structure Affect the Behavior of Partnering Firms?
Authors: Amaldoss Wilfred , Staelin Richard
Published: November 2009

Firms collaborate to develop and deliver new products. These collaborations vary in terms of the similarity of the competencies that partnering firms bring to the alliance. In same-function alliances, partnering firms have similar competencies, whereas in cross-function alliances, partners have very different competencies. On examining managers' view of these alliances, we find that, on average, same-function alliances are expected to perform better than cross-function alliances, holding fixed the level of inputs. A game-theoretic analysis shows that this apprehension about cross-function alliances is consistent with a Pareto-inferior equilibrium. A Pareto-superior equilibrium, however, suggests that partners in cross-function alliances may invest more in their alliances than those in same-function alliances. It is also often believed that increasing the number of partnering firms is not conducive for collaborative effort. Our analysis shows that this belief is correct for same-function alliances, but not for cross-function alliances. We test these equilibrium predictions in an experiment where we exogenously vary the type of alliance and the number of partnering firms. The experimental results lend support for the Pareto-superior equilibrium. Partners in cross-function alliances invested more than their counterparts in same-function alliances, and this difference in investment levels increased with the number of partnering firms. We extend our model to consider alliances where firms have an opportunity to learn from their partners and later leverage this knowledge outside the scope of their alliance. Though such learning increases the resources committed by alliance partners in the learning phase, it decreases investment in the subsequent competition and also dampens the overall investment across the two stages. In addition, an increase in interalliance competition decreases investments in the focal alliance but increases investment in the competition outside the scope of the alliance.
Reproduction and life history of the green alga Prasiola linearis Jao (Trebouxiophyceae, Chlorophyta)
Authors: Rindi Fabio
Published: November 2009

Marine species of Prasiola are most common on rocky shores of the North Atlantic and North Pacific Oceans. Prasiola linearis is a little-known member of this group, whose known distribution is restricted to coastal marshes of Pacific North America. The little information available on this species is mostly based on the original description; its life history has not been previously reported. Reproduction and life history were investigated in a series of experiments conducted in different combinations of culture medium, temperature, daylength and photon irradiance. The alga reproduced by aplanospores that were produced in the apical part of the blade. Upon release, each aplanospore reproduced a new thallus; sexual reproduction, which occurs in other marine species of Prasiola (P. stipitata and P. meridionalis) was not observed in P. linearis. No variation in reproductive patterns was observed between different combinations of factors tested; however, the alga showed very weak growth at 20°C. The life history of Prasiola linearis consists of a repetition of the same morphological phase reproducing by aplanospores. The diversity of life histories observed in marine species of Prasiola is illustrated and discussed.
Elevated serum γ-glutamyltransferase activity is associated with increased risk of mortality, incident type 2 diabetes, cardiovascular events, chronic kidney disease and cancer – a narrative review
Authors: Targher Giovanni
Published: November 2009

In clinical practice, increased serum γ-glutamyltransferase (GGT) activity is usually interpreted as a marker of alcohol abuse and liver dysfunction. The knowledge of the GGT's physiological functions has expanded and several important epidemiological associations have been reported. This review examines evidence for an association of high normal serum GGT enzyme activity, mostly within the reference range, with the risk of mortality and major vascular (i.e., cardiovascular morbidity and mortality) and non-vascular outcomes (i.e., incident type 2 diabetes, chronic kidney disease and cancer), independent of alcohol consumption and other prognostic factors.

Clin Chem Lab Med 2010;48:147–57.
The Effect of Structural and Performance Factors in the Perception of Anacruses
Authors: London Justin , Himberg Tommi , Cross Ian
Published: November 2009

WHEN A MELODY BEGINS WITH AN ANACRUSIS, (i.e.,"pick up" notes), rhythm and meter are out of phase. Three experiments were conducted to investigate the interactions between structural (rhythm and pitch) and performance (articulation and tempo) factors on the perception of anacruses. The independent variables were rhythmic figure, initial melodic direction, initial melodic interval, implied harmony, articulation, and tempo. Participants tapped "every other beat" to melodies composed for each experiment; the phase-alignment of taps with the stimulus was the dependent measure of anacrustic vs. non-anacrustic perception. Experiment 1 found a strong main effect for rhythmic figure and an interaction between rhythmic figure and tempo. Experiment 2 showed that as tempo increased there was a systematic shift toward anacrustic perception of some melodies. Experiment 3 found that in a rhythmically impoverished context, pitch-based structural factors had only a weak effect on the perception of anacrusis.
Perceptualism, Not Introspectionism: The Interpretation of Intuition-Based Theories
Authors: DeBellis Mark
Published: November 2009

DAVID TEMPERLEY HAS INTERPRETED INTUITION-BASED theories in music cognition, such as GTTM and his own theories, along introspectionist lines. Perception is a better model for such theories than introspection. It is obscure what introspective mechanism would make unconscious representations conscious while reliably preserving their content. The analyses that furnish data for intuition-based theories, moreover, must be in a public language for which there is a satisfactory account of meaning and understanding. It is unclear how this requirement is satisfied on an introspectionist model. A construal of intuition as perceptual judgment avoids these objections. The introspectionist model misleads us into thinking that intuition-based theories warrant conclusions about non-analytical listening. Limiting the data of intuition-based theories to appearances limits their scope and explanatory power, warranting complementation by other approaches in cognitive science.
In Defense of Introspectionism: A Response to DeBellis
Authors: Temperley David
Published: November 2009

DEBELLIS (2009) ARGUES THAT INTROSPECTIONIST music theory, as represented in my book The Cognition of Basic Musical Structures (CBMS; Temperley, 2001), makes an ungrounded assumption that the intuitions of the author are shared by other theorists and by experienced listeners generally. But this inductive leap is motivated by experimental and corpus evidence showing that, with regard to basic structures such as meter, listeners largely do hear things in the same way; and this assumption is confirmed in CBMS by corpus tests in which my analyses are compared to those of other listeners. DeBellis suggests that what I was doing in CBMS was not accessing unconscious representations, but rather bringing new representations into existence. But this implies either that experienced listeners in general do not represent meter at all, or that they arrive at metrical analyses by a pre-theoretic process that is not available to music theorists; neither of these options is plausible.
Music Training and Nonmusical Abilities: Commentary on Stoesz, Jakobson, Kilgour, and Lewycky (2007) and Jakobson, Lewycky, Kilgour, and Stoesz (2008)
Authors: Schellenberg E. Glenn
Published: November 2009

STOESZ, JAKOBSON, KILGOUR, AND LEWYCKY (2007) and Jakobson, Lewycky,Kilgour, and Stoesz (2008) examined whether music training is associated with nonmusical abilities. They concluded that their results provided evidence of "specific" associations between music training and local-processing abilities (Stoesz et al., 2007), and between music training and memory for verbal and visual stimuli (Jakobson et al., 2008). Closer inspection of their methods, consideration of the available literature, and a reanalysis of previous data reveal that these conclusions are debatable.Moreover, the causal direction of the observed associations could go either or both ways.
Bimusicalism: The Implicit Dual Enculturation of Cognitive and Affective Systems
Authors: Wong Patrick C. M. , Roy Anil K. , Margulis Elizabeth Hellmuth
Published: November 2009

ONE PROMINENT EXAMPLE OF GLOBALIZATION AND MASS cultural exchange is bilingualism, whereby world citizens learn to understand and speak multiple languages.Music, similar to language, is a human universal, and subject to the effects of globalization. In two experiments, we asked whether bimusicalism exists as a phenomenon, and whether it can occur even without explicit formal training and extensive music-making. Everyday music listeners who had significant exposure to music of both Indian (South Asian) and Western traditions (IW listeners) and listeners who had experience with only Indian or Western culture (I or W listeners) participated in recognition memory and tension judgment experiments where they listened to Western and Indian music. We found that while I and W listeners showed an in-culture bias, IW listeners showed equal responses to music from both cultures, suggesting that dual mental and affective sensitivities can be extended to a nonlinguistic domain.
A Distribution of Absolute Pitch Ability as Revealed by Computerized Testing
Authors: Bermudez Patrick , Zatorre Robert J.
Published: November 2009

BEHAVIORAL ASSESSMENT OF ABSOLUTE PITCH (AP) ability over the better part of the last century has strongly suggested that a variety of proficiency levels exists and can only be more comprehensively described with the use of rigorous testing providing precise and unbiased reaction times for all responses. This study describes the design, implementation and validation of a computerized test of absolute pitch and resulting data for 51 musicians, 27 of whom self-reported as AP possessors. The test was sensitive to previously reported differences in accuracy and timing for C major diatonic versus non-diatonic notes and showed a range of performance, from perfect to random, including a substantial number of intermediate levels of proficiency. We discuss the implications of detecting such a distribution of behavior as well as the effect of test design and scoring strategies on that distribution.
Presence and significance of a R110W mutation in the DNA-binding domain of GCM2 gene in patients with isolated hypoparathyroidism and their family members
Authors: Tomar Neeraj , Bora Hema , Singh Ratnakar , Gupta Nandita , Kaur Punit , Chauhan Shyam Singh , Sharma Yagya Dutta , Goswami Ravinder
Published: November 2009

Objective

Glial cells missing 2 (GCM2) gene encodes a parathyroid-specific transcription factor. We assessed GCM2 gene sequence in patients with isolated hypoparathyroidism (IH).

Design

Case–control study.

Methods

Complete DNA sequencing of the GCM2 gene including its exons, promoter, and 5′ and 3′ UTRs was performed in 24/101 patients with IH. PCR–restriction fragment length polymorphism was used to detect a novel R110W mutation in all 101 IH patients and 655 healthy controls. Significance of the mutation was assessed by electrophoretic mobility shift assay (EMSA) and nuclear localization on transfection.

Results

A heterozygous R110W mutation was present in DNA-binding domain in 11/101 patients (10.9%) and absent in 655 controls (P<10−7). Four of 13 nonaffected first-degree relatives for five of these index cases had R110W mutation. Four heterozygous single nucleotide polymorphisms were found in the 5′ region. One of the 11 patients with R110W also had T370M change in compound heterozygous form. Mutant R110W and T370M GCM2 proteins showed decreased binding with GCM recognition elements on EMSA indicating loss of function. Both wild-type and R110W mutant GCM2 proteins showed nuclear localization.

Conclusions

The present study indicates a significant association of R110W variant with IH. Absence of effect of heterozygous R110W mutation on DNA binding and presence of the same mutation in asymptomatic family members indicate that additional genetic (akin to T370M change) or nongenetic factors might contribute to the expression of diseases in IH. Alternatively, it is possible that association of R110W with IH could be due to linkage disequilibrium with the unidentified relevant genes in IH.
Short-term exposure to hydrogen peroxide during oocyte maturation improves bovine embryo development
Authors: Vandaele L , Thys M , Bijttebier J , Van Langendonckt A , Donnay I , Maes D , Meyer E , Van Soom A
Published: November 2009

Recent studies have shown that short-term exposure of oocytes to a stressor such as hydrostatic pressure or osmotic stress might induce stress tolerance in embryos. The aim of the present study was to investigate the consequences of short-term hydrogen peroxide (H2O2) exposure to bovinein vitromatured cumulus–oocyte complexes (COCs) on subsequent preimplantation embryo development and apoptosis. In the first experiment, mature COCs were incubated in H2O2at concentrations ranging between 0.01 and 100 μmol/l, and subsequently fertilized and cultured. Oocyte incubation with 50–100 μmol/l of H2O2resulted in a significantly higher blastocyst yield (47.3%) in comparison with control medium (31.8%), while apoptotic cell ratio was inversely related with H2O2concentration. In the second experiment, we showed that the stress tolerance after H2O2exposure was not mediated by increased glutathione content in treated oocytes nor by enhanced fertilization or penetration. Further research should concentrate on the potential role of players that have been associated with stress tolerance in somatic cell lines.
Recent Trends in State Children's Health Insurance Program Eligibility and Coverage for CSHCN
Authors: Yu Hao , Dick Andrew W.
Published: November 2009

OBJECTIVE: Policy makers and physicians need to understand recent trends in State Children's Health Insurance Program (SCHIP) eligibility and coverage given the ongoing debate on SCHIP. Although many studies have examined these issues, few have focused on children with special health care needs (CSHCN). With this study we aimed to fill this gap in the literature.

METHODS: Data on state-specific SCHIP eligibility criteria were merged with the National Survey of Children With Special Health Care Needs to determine SCHIP eligibility and coverage in 2001 and 2005. In addition to descriptive analysis, a multilevel analysis was performed to identify personal and state-level factors that significantly affected uninsurance among the SCHIP-eligible CSHCN.

RESULTS: Our analyses showed that there was a slight increase in SCHIP eligibility for CSHCN between 2001 and 2005 (8.44% vs 9.83%; P < .05, χ2 test). Among the SCHIP-eligible CSHCN, we found a substantial decrease in the uninsurance rate from 21.15% in 2001 to 10.87% in 2005 (P < .05, χ2 test). After controlling for covariates, our analyses indicated that CSHCN in 2005 were 57% less likely to be uninsured than those in 2001. Our multilevel analysis also identified state policies that significantly affected uninsurance among the SCHIP-eligible CSHCN, including asset tests (positive effects) and presumptive eligibility (negative effects).

CONCLUSION: Our results show a dramatic decrease in the uninsurance rate among SCHIP-eligible CSHCN between 2001 and 2005.