bluuebunny/crossref_metadata_2025 huggingface dataset:
Increased Regulatory T-Cell Fraction Amidst a Diminished CD4 Compartment Explains Cellular Immune Defects in Patients with Malignant Glioma
Authors: Fecci Peter E. , Mitchell Duane A. , Whitesides John F. , Xie Weihua , Friedman Allan H. , Archer Gary E. , Herndon James E. , Bigner Darell D. , Dranoff Glenn , Sampson John H.
Published: March 2006

Immunosuppression is frequently associated with malignancy and is particularly severe in patients with malignant glioma. Anergy and counterproductive shifts toward TH2 cytokine production are long-recognized T-cell defects in these patients whose etiology has remained elusive for >30 years. We show here that absolute counts of both CD4+ T cells and CD4+CD25+FOXP3+CD45RO+ T cells (Tregs) are greatly diminished in patients with malignant glioma, but Tregs frequently represent an increased fraction of the remaining CD4 compartment. This increased Treg fraction, despite reduced counts, correlates with and is sufficient to elicit the characteristic manifestations of impaired patient T-cell responsiveness in vitro. Furthermore, Treg removal eradicates T-cell proliferative defects and reverses TH2 cytokine shifts, allowing T cells from patients with malignant glioma to function in vitro at levels equivalent to those of normal, healthy controls. Such restored immune function may give license to physiologic antiglioma activity, as in vivo, Treg depletion proves permissive for spontaneous tumor rejection in a murine model of established intracranial glioma. These findings dramatically alter our understanding of depressed cellular immune function in patients with malignant glioma and advance a role for Tregs in facilitating tumor immune evasion in the central nervous system. (Cancer Res 2006; 66(6): 3294-302)
A Factor Analytic Study of the Cross-Cultural Adaptability Inventory
Authors: Davis Susan L. , Finney Sara J.
Published: March 2006

The Cross-Cultural Adaptability Inventory (CCAI) was developed as a tool to assess an individual's effectiveness in cross-cultural interaction and communication. Because limited validity evidence had been published regarding the CCAI, the purpose of the current study is to evaluate the psychometric properties of CCAI scores, specifically focusing on the replicability of the proposed four-factor structure. This study is based on responses from a sample of 709, primarily Caucasian, college sophomores at a mid-Atlantic university. Confirmatory factor analysis indicated poor fit of the four-factor structure and follow-up exploratory factor analyses failed to reveal an interpretable structure. Possible explanations of poor fit are discussed, and recommendations for further research are suggested.
Misclassification Rates for Four Methods of Group Classification
Authors: Finch W. Holmes , Schneider Mercedes K.
Published: March 2006

This study compares the classification accuracy of linear discriminant analysis (LDA), quadratic discriminant analysis (QDA), logistic regression (LR), and classification and regression trees (CART) under a variety of data conditions. Past research has generally found comparable performance of LDA and LR, with relatively less research on QDA and virtually none on CART. This study uses Monte Carlo simulations to assess the crossvalidated predictive accuracy of these methods, while manipulating such factors as predictor distribution, sample size, covariance matrix inequality, group separation, and group size ratio. The results indicate that QDA performs as well as or better than the other alternatives in virtually all conditions. Suggestions for practitioners are provided.
Loss of Power in Logistic, Ordinal Logistic, and Probit Regression When an Outcome Variable Is Coarsely Categorized
Authors: Taylor Aaron B. , West Stephen G. , Aiken Leona S.
Published: March 2006

Variables that have been coarsely categorized into a small number of ordered categories are often modeled as outcome variables in psychological research. The authors employ a Monte Carlo study to investigate the effects of this coarse categorization of dependent variables on power to detect true effects using three classes of regression models: ordinary least squares (OLS) regression, ordinal logistic regression, and ordinal probit regression. Both the loss of power and the increase in required sample size to regain the lost power are estimated. The loss of power and required sample size increase were substantial under conditions in which the coarsely categorized variable is highly skewed, has few categories (e.g., 2, 3), or both. Ordinal logistic and ordinal probit regression protect marginally better against power loss than does OLS regression.
Bayesian Factor Analysis When Only a Sample Covariance Matrix Is Available
Authors: Hayashi Kentaro , Arav Marina
Published: March 2006

In traditional factor analysis, the variance-covariance matrix or the correlation matrix has often been a form of inputting data. In contrast, in Bayesian factor analysis, the entire data set is typically required to compute the posterior estimates, such as Bayes factor loadings and Bayes unique variances. We propose a simple method for computing the posterior estimates of Bayesian factor analysis using only the sample variance-covariance matrix without the entire data set. The method is verified in terms of an existing data set. With our method, researchers will be able to apply Bayesian factor analysis when they find either a variance-covariance or a correlation matrix with standard deviations in the existing literature.
Long-Term Stability and Reliability of Scores on the Peer-Relations Subscale of the Self-Esteem Questionnaire
Authors: Hunter Simon C. , Boyle James M. E. , Warden David
Published: March 2006

The stability of scores on the Peer-Relations subscale of the Self-Esteem Questionnaire (SEQ) was examined over 11 to 13 months, longer than in previous research. Participants were 839 mainstream Scottish pupils aged 8 to 14 years old (48% male), allowing for the psychometric qualities of the scale to be assessed in a younger sample than previously examined. The subscale scores displayed good internal reliability and moderate testretest stability. Stability did not differ statistically significantly according to gender or school stage, and there were no gender or school-stage effects in relation to actual scores on the subscale. The Peer-Relations subscale of the SEQ appears to yield reliable scores for use with children as young as 8 years old.
Evaluating the Predictive Validity of Graduate Management Admission Test Scores
Authors: Sireci Stephen G. , Talento-Miller Eileen
Published: March 2006

Admissions data and first-year grade point average (GPA) data from 11 graduate management schools were analyzed to evaluate the predictive validity of Graduate Management Admission Test® (GMAT®) scores and the extent to which predictive validity held across sex and race/ethnicity. The results indicated GMAT verbal and quantitative scores had substantial predictive validity, accounting for about 16% of the variance in graduate GPA beyond that predicted by undergraduate GPA. When these scores and undergraduate GPA were used together, they accounted for approximately 25% of the variation in first-year graduate GPA. Correcting correlations for restriction of range improved the predictive power. No statistical differences were found across examinee groups defined by race/ethnicity and sex, which suggests a lack of bias in these scores. The predictive utility of GMAT analytical writing scores was relatively low, accounting for only about 1% of the variation in graduate GPA, after accounting for undergraduate GPA and GMAT verbal and quantitative scores.
Goal Orientations
Authors: Attenweiler William J. , Moore DeWayne
Published: March 2006

Goal orientation research has developed two branches. One branch uses a two-factor dispositional model. The other branch uses a three-factor domain-specific model. The present multiwave study examines dispositional goal orientation constructs through both two and three-factor models using repeated-measure confirmatory factor analysis. Results indicate dispositional performance goal orientation of the two-factor model can be better partitioned into the Prove and Avoid factors of the three-factor model. Further evidence is presented indicating the potential for more than three factors by further partitioning the Avoid factor into two separate constructs. Consistent with both branches of goal orientation research, learning goal orientation is largely independent of Performance, Prove, and Avoid factors in all tested models.
Assessing the Dimensionality and Factor Structure of Multiple-Choice Exams
Authors: Stone Clement A. , Yeh Chien-Chi
Published: March 2006

Examination of a test's internal structure can be used to identify what domains or dimensions are being measured, identify relationships between the dimensions, provide evidence for hypothesized multidimensionality and test score interpretations, and identify construct-irrelevant variance. The purpose of this research is to provide a methodological comparison of three methods for assessing the dimensionality and factor structure for binary scored exams in which guessing may be operating. The factor analytic methods in Mplus, NOHARM, and TESTFACT are compared in the context of analyzing the Multistate Bar Examination, a multiple-choice exam reflecting a number of complex integrated content domains. Results indicate that the methods support similar factor solutions. However, support for solutions with more factors and more indicators per factor is only obtained when guessing is modeled. The implications for evaluating the internal structure of multiple-choice tests are discussed.
A Reliability Generalization Study of the Self-Description Questionnaire
Authors: Leach Lesley F. , Henson Robin K. , Odom Leslie R. , Cagle Lynne S.
Published: March 2006

The use of reliability generalization methodology promises to, among other things, inform researchers about the importance of reporting reliability coefficients and their use in result interpretation. This study presents results from a reliability generalization study of the Self-Description Questionnaire (SDQ). The average score reliabilities produced by the instrument as well as sample and instrument characteristics that may affect those reliabilities are presented. Results varied somewhat across the three SDQ instruments and their various subscales, but internal consistency estimates were generally strong for the SDQ.
Introduction to the Special Issue. In Search of Organizational Virtue: Moral Agency in Organizations
Authors: Nielsen Richard P.
Published: March 2006

This editorial provides an introduction to the themes of this ‘Special Issue on Organizational Virtue and Moral Agency in Organizations’. MacIntyre, in After Virtue (1981), critically observed that, under the severe pressures of narrowly focused, system-driven, utilitarian financial and bureaucratic calculation, it can be very difficult both for organizations and individuals in their organizational lives to realize and express moral agency and virtue. The articles contained here trace the development of MacIntyre’s analysis of this possibility and consider how organizational pressures against moral agency can be an important problem. In addition, the special issue considers how both philosophical and social-behavioral science approaches reveal similar problems and diagnoses. Further, there is discussion of how the possibilities of and constraints on virtue vary and are more and less severe in different types of organizational systems and situations. The special issue also considers what degrees of freedom, and even methods, organizational members may have available to them in different types of constrained organizational circumstances.
MacIntyre on Virtue and Organization
Authors: Beadle Ron , Moore Geoff
Published: March 2006

This paper introduces the work of moral philosopher Alasdair MacIntyre in the area of virtue and organization. It aims to provide one point of entry to MacIntyre’s work for readers who have not been introduced to it and makes some novel suggestions about its development for those who have. Following some initial comments on MacIntyre’s approach to social science, it traces the development of his ideas on organization from 1953 to 1980, before outlining the general theory of virtues, goods, practices and institutions which emerged in the publication of his seminal After Virtue in 1981. Finally, the paper outlines some of the uses to which these ideas have been put in the organizational literature.
In Search of Organizational Virtue in Business: Agents, Goods, Practices, Institutions and Environments
Authors: Moore Geoff , Beadle Ron
Published: March 2006

In this paper we argue that MacIntyre’s virtues-goods-practice-institution schema (MacIntyre 1985) provides a conceptual framework within which organizational virtue in general, and virtue in business in particular, can be explored. A heuristic device involving levels of individual agency, mode of institutionalization and environment is used to discuss why some businesses protect practices, develop virtues and encourage the exercise of moral agency in their decision making, while others struggle or fail to do so. In relation to conventional shareholder-owned capitalist business, both the mode of institutionalization and the environment are shown to be largely antithetical to the development of practices. Other businesses may meet the necessary internal conditions for the sustenance of practice-like features but remain dependent upon features within their environments. To illustrate this, we use participant observation to show how one particular organization—Traidcraft plc—meets the relevant conditions.
The Ethics of the Node versus the Ethics of the Dyad? Reconciling Virtue Ethics and Contractualism
Authors: Heugens Pursey P.M.A.R. , Kaptein Muel , Oosterhout J. (Hans) van
Published: March 2006

Some centers of gravity are finally emerging in the field of business ethics after a decades-long search for action-guiding theories. Among the foremost of these are contractualism and virtue ethics. The former focuses on the morals of economic exchange, the latter on the moral qualities of economic actors. We demonstrate that these dyadic and nodal ethics are not competing contenders to the throne of business ethics, but complementary approaches that are best used in tandem if we want to identify the generic normative core of the field. Specifically, virtue ethicists benefit from contractualists’ aptitude for highlighting the conditions that exchange relationships must meet in order to become vehicles for the pursuit of excellence. In turn, contractualists profit from virtue ethicists’ ability to identify the qualities actors must possess to efficaciously engage in exchange transactions.
Conventional versus Radical Moral Agents: An Exploratory Empirical Look at Weber’s Moral-points-of-view and Virtues
Authors: Dyck Bruno , Weber J. Mark
Published: March 2006

Max Weber’s work suggests that conventional management theory and practice is underpinned by a moral-point-of-view that places relatively high emphasis on both materialism and individualism. He calls for the development of radical management theory and practices to serve as a counterpoint. Both the conventional and radical moral-points-of-view are associated with specific virtues and practices. Weber suggests that, from a conventional moral-point-of-view, four primary virtues—mercy, submission, obedience and non-worldliness—give rise to specialization, centralization, formalization and standardization. In contrast, from a radical moral-point-of-view, these same four primary virtues are expected to give rise to sensitization, dignification, participation and experimentation (Dyck and Schroeder 2005). Our study contrasts and compares a sample of conventional and radical managers, to provide an empirical look at these expected differences, as well as testing for differences in their personal and spiritual virtues. Implications are discussed.
The Essential Leadership Model
Authors: Knuth Richard K. , Banks Patricia Anne
Published: March 2006

This article introduces the reader to the Essential Leadership Model (ELM). The ELM provides a vocabulary and framework for clarifying and prioritizing the many complex and competing demands of the principalship. The ELM supports principals in identifying the critical needs of a school and the leadership knowledge, skills, and dispositions to meet these needs. The model assumes an order of operations that effective principals employ to create the preconditions or structures that facilitate the work necessary for meaningful school improvement.
“We Can't Afford to Rest on Our Laurels”: Creating a District-Wide Content Literacy Instructional Plan
Authors: Frey Nancy
Published: March 2006

Districts in communities experiencing population shifts are being challenged to address three concerns simultaneously: be responsive to the strengths and educational needs of students from increasingly diverse backgrounds, provide meaningful professional development for an expanding or contracting workforce to meet those needs, and ensure that state and federal accountability targets are met. This study reports on the efforts of one such district to design and implement a district-wide content literacy instructional plan for its middle and high schools. The results of the study show that the district was able to meet all accountability targets despite shifts in student demographics and a 16% increase in the number of teachers on staff.
Texas Middle School Principals' Perceptions of Bullying on Campus
Authors: Harris Sandra , Hathorn Conley
Published: March 2006

Most bullying data to date have been gathered through student reports. This study surveyed 59 middle school principals to better understand their perceptions of bullying on their campus. The study found that compared to students, principals have a different awareness of bullying. In addition, nearly all of the principals considered the school very safe and felt that they were highly supportive of reducing bullying. This is not in agreement with other research that has found that students do not always consider their schools safe, nor do students view administration as supportive of reducing bullying.
Interactive service work and performative metaphors
Authors: Weaver Adam
Published: March 2006

This article analyses the use of performative metaphors in studies that examine interactive service work in the tourism industry. That these metaphors provide a valuable means to conceptualize this type of work is not disputed. Performative metaphors aptly capture the nature of service work, with its unpredictability and audience scrutiny. However, performative metaphors can be extended so that they address not only the embodied actions of service employees but also the social relations that shape ‘theatrical’ production. Tourism researchers could deploy these metaphors in ways that exhibit the broader power structures that affect the enactment of interactive service work. In this article, it is demonstrated that performative metaphors can be used to articulate the often difficult conditions and circumstances under which cruise-ship service employees work.
Bridging the interdisciplinary divide
Authors: Jamal Tazim , Kim Hyounggon
Published: March 2006

This study draws upon recent learnings of the dynamic context of travel, tourism and touristic practices to propose an interdisciplinary framework for heritage tourism research. Interdisciplinary barriers and intradisciplinary ‘prejudices’ have instilled fragmented, dualistic either/or approaches to heritage tourism research that perpetuate a micro-macro divide. Studies that decontextualize the individual (micro-level) from social structures (macro-level) belie the complexity of heritage and tourism. Production-consumption, local-global and economic supply-demand binaries are pointed out in the article, and theoretical attempts to bridge the binaries are discussed. It is argued that viewing heritage and tourism as performative practices involving relational forms of power, agency and dialogue helps bridge the micro-macro divide. The research challenges are illustrated using the example of a festival representing a medieval heritage: the Texas Renaissance Festival, USA. This case illustrates the importance of identifying the global, historical and postcolonial context in which the local festival and the individual tourist are situated. Directions are offered for developing an integrated knowledge base of the sociopolitical context, structures and practices that constitute heritage tourism.
‘Who is a tourist?’
Authors: McCabe Scott
Published: March 2006

This article discusses the concept of the ‘tourist’ within tourist studies. It critiques the conceptual category of tourist in recent literature on typologies of tourists and tourist experiences. Although greater understanding of the tourist has been identified as one of the principal research issues for tourism research, the focus is on types and forms of touristic experience rather than uses of the concept of ‘tourist’ as a lay category, thereby taking for granted its function within a wider cultural discourse of holidaymaking and travelling. The article raises questions concerning the construct ‘tourist’ and discusses the implications of such ambiguities for theory and empirical analysis of interview data on tourist experiences. This discussion reviews the literature on tourist experience and typologies, a discussion of the use of the concept of ‘tourist’ as a members’ category, and proposes a tentative clarification of the issues as a basis from which to direct future empirical research questions.
Crime and Criminal Policy in Iceland
Authors: Ólafsdóttir Hildigunnur , Bragadóttir Ragnheidur
Published: March 2006

Icelandic criminologists have classified Iceland as a country in which offences are rare. Despite an increase in crime during the 1990s, the incarceration figures are among the lowest in Europe. An overview of Icelandic research on crime and criminal justice over the past five years shows diversity in the topics chosen but also indicates that in certain areas there is no research to be found. The chief topics addressed in recent Icelandic work include the formation of boundaries between deviance and conformity, fear of crime, problems in the city centre, recidivism, the social status of inmates, youth crime and long-term trends in punishment for violent offences. This article traces how public discussion of criminal policy in recent years has centred on making punishments more severe. It will be shown that the demand for more severe punishment for drug offences is driven by utilitarian motives, whereas the arguments for punishment for sexual offences are based on the principle of retribution. At the end of the 20th century, attitudes toward crime and punishment were characterized by a consensus that is seen clearly in attitudes toward drug offences, whereas political divisions have recently emerged in discussion of sexual offences.
A prospective clinical study of cerebral microemboli and neuropsychological outcome comparing vent-line and auto-venting arterial line filters: both filters are equally safe
Authors: Whitaker Donald C , Stygall Jan , Hope-Wynne Chris , Walesby Robin K , Harrison Michael JG , Newman Stanton P
Published: March 2006

Introduction: Microemboli are the main implicated cause of neuropsychological (NP) impairment after cardiac surgery. This prospective clinical trial compared the effect of an auto-venting arterial line filter on intraoperative cerebral microemboli and NP outcome compared to an arterial line filter with a vent line, in patients undergoing elective coronary artery bypass graft (CABG) surgery.

Methods: One hundred and ten patients received either an Avecor Affinity ( n = 73) or Pall AV-6 ( n = 37) control filter. Cerebral microemboli during cardiopulmonary bypass were recorded by transcranial Doppler monitoring of the right middle cerebral artery. Evidence of cerebral impairment was obtained by comparing patients’ performance in a NP test battery (nine tests) administered 6-8 weeks postoperatively with their pre-operative scores.

Results: During cardiopulmonary bypass, the median number and range of microemboli were 67 (5-846) and 55 (2-773) for the Avecor and AV-6 groups, respectively ( p = 0.47). There was no difference in NP outcome.

Conclusion: There is no difference in the filtering ability of vent-line and auto-vent filters as assessed by cerebral microemboli. This, together with the similar NP outcome, suggests that both types of filter are equally safe for clinical use.
Cardiopulmonary bypass for a coronary artery bypass graft patient with heterozygous protein C deficiency and protein S deficiency
Authors: Schneider Susan , Sakert Tamara , Lucke John , McKeown Peter , Sharma Ajeet
Published: March 2006

Cardiopulmonary bypass (CPB) poses great risks for hypercoagulable patients and requires management techniques to ensure an optimal outcome free from thrombotic events. This case report reviews perfusion management techniques that may contribute to a safer CPB experience for a patient deficient in both protein C and protein S. A patient with heterozygous protein C deficiency is at increased risk of thrombosis, especially in the venous circulation. Since it is an essential cofactor for activated protein C, deficiency of free protein S is also linked to a hypercoagulable condition.

A 52-year-old male presented to our institution with a past medical history of hypercoagulable state, multiple deep vein thromboses, pulmonary embolisms, and stroke. He was scheduled for two-vessel coronary artery bypass graft surgery to be followed by right carotid endarterectomy (RCEA) before discharge.

The anesthesia and perfusion teams worked closely together to ensure that fresh frozen plasma (FFP) was given intraoperatively at appropriate times. Heparin dose response and protamine dosage was determined with hemostasis management system (HMS) analysis. The closed CPB circuit and cannulae were Carmeda bonded. Rapid autologous priming, along with the use of a hemoconcentrator, kept the hematocrit above 21 during CPB. Zero-balance ultrafiltration and leukocyte depletion were initiated during rewarming to aid in attenuation of the inflammatory response. To conserve coagulation factors, all pump blood was ultrafiltrated post-CPB and returned to the patient.

Laboratory samples drawn on postoperative day (POD) one measured normal protein C activity with subnormal protein S activity. On POD six, the patient underwent RCEA and he was discharged on POD eight without complications.
A recovery model of minimally invasive cardiopulmonary bypass in the rat
Authors: Modine T , Azzaoui R , Fayad G , Lacroix D , Bordet R , Warembourg H , Gourlay T
Published: March 2006

This study was undertaken to develop a rodent (rat) model of cardiopulmonary bypass (CPB) that has been designed to mimic functionally the minimally invasive clinical setting. The circuit is similar to the clinical model in terms of its construction, configuration, material surface area to blood volume ratio, and priming volume to blood ratio. The overall priming volume was 10 mL. Thirty-six male Sprague-Dawley rats (422±32 g) were anaesthetized while maintaining spontaneous ventilation. Anticoagulation was achieved with heparin (500 IU/kg). Blood arterial pressure was monitored continuously. Normal central temperature was maintained throughout. Intermittent arterial blood gas levels also were monitored. All animals were cannulated in preparation for CPB; however, CPB, utilizing a double roller pump and a flow rate of 100 mL/kg/minute for 60 min, was initiated in only 18 animals, the remaining 18 animals acting as non-CPB controls (Sham). The animals were haemodynamically stable.

After the operative procedure, the animals were allowed to recover from the anaesthesia and, after transfer to a recovery facility, were monitored for a period of 1 week.

There were no differences between the groups in terms of blood gas analysis and blood pressure data; all animals survived the procedure and had an uneventful follow-up. Differences were found between the CPB animals and the Sham group in terms of TNFα, used as a marker of inflammatory processes. This trend tends to support this model as an analogue for the clinical scenario for future studies of CPB-related inflammation.

Overall, the CPB procedure was easy to perform and was associated with excellent survival. This recovery model is an effective tool to perform pathophysiological studies associated with minimally invasive CPB.
A statistical analysis of factors predisposing patients to heparin resistance
Authors: Chan Tanee , Hwang Nian Chih , Lim Chong Hee
Published: March 2006

Heparin resistance (HR) is occasionally encountered in cardiac surgery. The objective of this study is to identify possible factors predisposing patients to heparin resistance. Four hundred patients scheduled for elective cardiac surgery requiring the use of cardiopulmonary bypass (CPB) were enrolled in this study. Data collection included: demographic data, types of preoperative anti-coagulant/antiplatelet therapy, preoperative haematological and biochemical laboratory results, medical condition, baseline activated clotting time (ACT) and infusion volume prior to heparinisation. Patients who require 5 mg/kg or more to achieve ACT greater than 400 seconds before CPB were considered to be heparin resistant. All data was tested with a preliminary univariate analysis and factors associated with HR ( p value <0.05) were entered into a multivariate logistic regression analysis. Factors associated with HR with a p value <0.05 are considered predictors for HR. Thirty-two (8.0%) of the 400 patients fulfilled the criteria for HR. Preoperative heparin ( p = 0.025), low molecular weight heparin ( p = 0.049), plateletcount ≥ 300,000/ml ( p = 0.022) and albumin plasma concentration ≤ 35 g/dl 0, = 0.044) are significantly associated with HR. HR patients also tend to require more volume replacement prior to CPB to maintain haemodynamic stability p=0.007).
Testing of heat exchangers in membrane oxygenators using air pressure
Authors: Hamilton Carole , Stein Jutta , Seidler Rainer , Kind Robert , Beck Karin , Tosok Jürgen , Upterfofel Jörg
Published: March 2006

All heat exchangers (HE) in membrane oxygenators are tested by the manufacturer for water leaks during the production phase. However, for safety reasons, it is highly recommended that HEs be tested again before clinical use. The most common method is to attach the heater-cooler to the HE and allow the water to recirculate for at least 10 min, during which time a water leak should be evident. To improve the detection of water leaks, a test was devised using a pressure manometer with an integrated bulb used to pressurize the HE with air.

The cardiopulmonary bypass system is set up as per protocol. A pressure manometer adapted to a 1/2″ tubing is connected to the water inlet side of the oxygenator. The water outlet side is blocked with a short piece of 1/2″ dead-end tubing. The HE is pressurized with 250 mmHg for at least 30 sec and observed for any drop.

Over the last 2 years, only one oxygenator has been detected with a water leak in which the air-method leak-test was performed. This unit was sent back to the manufacturer who confirmed the failure.

Even though the incidence of water leaks is very low, it does occur and it is, therefore, important that all HEs are tested before they are used clinically. This method of using a pressure manometer offers many advantages, as the HE can be tested outside of the operating room (OR), allowing earlier testing of the oxygenator, no water contact is necessary, and it is simple, easy and quick to perform.
Systemic arterial waveform analysis and assessment of blood flow during extracorporeal circulation
Authors: Romano Salvatore M , Scolletta Sabino , Olivotto Iacopo , Biagioli Bonizella , Gensini Gian Franco , Chiostri Marco , Giomarelli Pierpaolo
Published: March 2006

Background: The pressure recording analytical method (PRAM) is a method for real-time beat-to-beat quantification of peripheral blood flow based on the analysis of arterial waveform morphology. Since PRAM can be implemented in any conditions of flow, whether physiological or artificial, we assessed its accuracy in patients undergoing cardiac surgery during extracorporeal circulation (ECC), using the roller-pump device as the reference gold standard.

Methods: We prospectively studied 32 patients undergoing elective coronary surgery. Flow values obtained by PRAM from the radial artery were compared with simultaneous values by thermodilution in physiological conditions of flow and with the roller-pump device readings during ECC.

Results: Before and after ECC, the overall estimates of flow measured by PRAM closely agreed with thermodilution (mean difference 0.07±0.40 L/min). During ECC, PRAM estimates of flow also closely correlated with simultaneous pump readings (mean difference 0.11±0.33 L/min). At time of weaning from ECC, two patterns of hemodynamic adaptation were documented by PRAM following resumption of cardiac contraction: in most patients ( n = 26; 80%), cardiac output (CO) was stable (reduction ≤ 10% compared to the steady ECC phase); six patients (20%) showed a fall in CO exceeding 10% and up to 38%.

Conclusions: PRAM provided accurate, continuous quantification of peripheral blood flow during each phase of cardiac surgery, including ECC, and allowed early recognition of patients with low CO during weaning from the pump.
Patterning the earlyXenopusembryo
Authors: Heasman Janet
Published: March 2006

Developmental biology teachers use the example of the frog embryo to introduce young scientists to the wonders of vertebrate development, and to pose the crucial question, `How does a ball of cells become an exquisitely patterned embryo?'. Classical embryologists also recognized the power of the amphibian model and used extirpation and explant studies to explore early embryo polarity and to define signaling centers in blastula and gastrula stage embryos. This review revisits these early stages of Xenopusdevelopment and summarizes the recent explosion of information on the intrinsic and extrinsic factors that are responsible for the first phases of embryonic patterning.
p63 regulates multiple signalling pathways required for ectodermal organogenesis and differentiation
Authors: Laurikkala Johanna , Mikkola Marja L. , James Martyn , Tummers Mark , Mills Alea A. , Thesleff Irma
Published: March 2006

Heterozygous germline mutations in p63, a transcription factor of the p53 family, result in abnormal morphogenesis of the skin and its associated structures, including hair follicles and teeth. In mice lacking p63, all ectodermal organs fail to develop, and stratification of the epidermis is absent. We show that the ectodermal placodes that mark early tooth and hair follicle morphogenesis do not form in p63-deficient embryos, although the multilayered dental lamina that precedes tooth placode formation develops normally. The N-terminally truncated isoform of p63(ΔNp63) was expressed at high levels in embryonic ectoderm at all stages of tooth and hair development, and it was already dominant over the transactivating TAp63 isoform prior to epidermal stratification. Bmp7,Fgfr2b, Jag1 and Notch1 transcripts were co-expressed withΔNp63 in wild-type embryos, but were not detectable in the ectoderm of p63 mutants. In addition, β-catenin and Edartranscripts were significantly reduced in skin ectoderm. We also demonstrate that BMP2, BMP7 and FGF10 are potent inducers of p63 in cultured tissue explants. Hence, we suggest that p63 regulates the morphogenesis of surface ectoderm and its derivatives via multiple signalling pathways.
Why Beauty Matters
Authors: Mobius Markus M , Rosenblat Tanya S
Published: March 2006

We decompose the beauty premium in an experimental labor market where “employers” determine wages of “workers” who perform a maze-solving task. This task requires a true skill which we show to be unaffected by physical attractiveness. We find a sizable beauty premium and can identify three transmission channels: (a) physically attractive workers are more confident and higher confidence increases wages; (b) for a given level of confidence, physically attractive workers are (wrongly) considered more able by employers; (c) controlling for worker confidence, physically attractive workers have oral skills (such as communication and social skills) that raise their wages when they interact with employers. Our methodology can be adopted to study the sources of discriminatory pay differentials in other settings.
Do Labor Issues Matter in the Determination of U.S. Trade Policy? An Empirical Reevaluation
Authors: Matschke Xenia , Sherlund Shane M
Published: March 2006

Some recent empirical studies, motivated by Grossman and Helpman's (1994) “protection-for-sale” model, suggest that very few factors (none of them labor related) determine trade protection. This paper reexamines the roles that labor issues play in the determination of trade policy. We introduce collective bargaining, differences in inter industry labor mobility, and trade union lobbying into the protection-for-sale model, and show that the equilibrium protection rate in our model depends upon these labor market variables. We test our model predictions using data from U.S. manufacturing and find that labor market considerations do seem to matter for U.S. trade policy.
Inequality, Lobbying, and Resource Allocation
Authors: Esteban Joan , Ray Debraj
Published: March 2006

This paper describes how wealth inequality may distort public resource allocation. A government seeks to allocate limited resources to productive sectors, but sectoral productivity is privately known by agents with vested interests in those sectors. They lobby the government for preferential treatment. The government—even if it honestly seeks to maximize economic efficiency—may be confounded by the possibility that both high wealth and true economic desirability create loud lobbies. Broadly speaking, both poorer economies and unequal economies display greater public misallocation. The paper warns against the conventional wisdom that this is so because such governments are more “corrupt.”
Can Rational Expectations Sticky-Price Models Explain Inflation Dynamics?
Authors: Rudd Jeremy , Whelan Karl
Published: March 2006

The canonical inflation specification in sticky-price rational expectations models (the new-Keynesian Phillips curve) is often criticized for failing to account for the dependence of inflation on its own lags. In response, many studies employ a “hybrid” specification in which inflation depends on its lagged and expected future values, together with a driving variable such as the output gap. We consider some simple tests of the hybrid model that are derived from its closed form. We find that the hybrid model describes inflation dynamics poorly, and find little empirical evidence for the type of rational, forward-looking behavior that the model implies.
An Alternative Test of Racial Prejudice in Motor Vehicle Searches: Theory and Evidence
Authors: Anwar Shamena , Fang Hanming
Published: March 2006

We propose a simple model of trooper behavior to design empirical tests for whether troopers of different races are monolithic in their search behavior, and whether they exhibit relative racial prejudice in motor vehicle searches. Our test of relative racial prejudice provides a partial solution to the well-known inframarginality and omitted-variables problems associated with outcome tests. When applied to a unique dataset from Florida, our tests soundly reject the hypothesis that troopers of different races are monolithic in their search behavior, but the tests fail to reject the hypothesis that troopers of different races do not exhibit relative racial prejudice.
Managing Growth to Achieve Efficient Coordination in Large Groups
Authors: Weber Roberto A
Published: March 2006

Previous experiments using the minimum-effort coordination game reveal a striking regularity—large groups never coordinate efficiently. Given the frequency with which large real-world groups, such as firms, face similarly difficult coordination problems, this poses an important question: Why do we observe large, successfully coordinated groups in the real world when they are so difficult to create in the laboratory? This paper presents one reason. The experiments show that, even though efficient coordination does not occur in groups that start off large, efficiently coordinated large groups can be “grown.” By starting with small groups that find it easier to coordinate, we can add entrants—who are aware of the group's history—to create efficiently coordinated large groups. This represents the first experimental demonstration of large groups tacitly coordinated at high levels of efficiency.
Persistent Distortionary Policies with Asymmetric Information
Authors: Mitchell Matthew F , Moro Andrea
Published: March 2006

Why are distortionary policies used when seemingly Pareto improvements exist? According to a standard textbook argument, a Pareto improvement can be obtained by eliminating the distortions, compensating the losers with a lump sum transfer, and redistributing the gains that are left over. We relax the assumption that winners know the losses suffered by the losers and show that the informationally efficient method of compensating losers may involve the use of seemingly inefficient (but informationally efficient) distortionary policies. The risk of overcompensating losers may make distortions informationally efficient, as there are points on the Pareto frontier where distortions are used.
Wealth Concentration in a Developing Economy: Paris and France, 1807–1994
Authors: Piketty Thomas , Postel-Vinay Gilles , Rosenthal Jean-Laurent
Published: March 2006

Using large samples of estate tax returns, we construct new series on wealth concentration in Paris and France from 1807 to 1994. Inequality increased until 1914 because industrial and financial estates grew dramatically. Then, adverse shocks, rather than a Kuznets-type process, led to a massive decline in inequality. The very high wealth concentration prior to 1914 benefited retired individuals living off capital income (rentiers) rather than entrepreneurs. The very rich were in their seventies and eighties, whereas they had been in their fifties a half century earlier and would be so again after World War II. Our results shed new light on ongoing debates about wealth inequality and growth.
Advertising Content
Authors: Anderson Simon P , Renault Régis
Published: March 2006

Empirical evidence suggests that most advertisements contain little direct information. Many do not mention prices. We analyze a monopoly firm's choice of advertising content and the information disclosed to consumers. The firm advertises only product information, price information, or both, and prefers to convey only limited product information if possible. It is socially harmful to force it to provide full information if it has sufficient ability to parse the information imparted, nor does it help to restrict the information voluntarily provided.
Estimating Average and Local Average Treatment Effects of Education when Compulsory Schooling Laws Really Matter
Authors: Oreopoulos Philip
Published: March 2006

The change to the minimum school-leaving age in the United Kingdom from 14 to 15 had a powerful and immediate effect that redirected almost half the population of 14-year-olds in the mid-twentieth century to stay in school for one more year. The magnitude of this impact provides a rare opportunity to (a) estimate local average treatment effects (LATE) of high school that come close to population average treatment effects (ATE); and (b) estimate returns to education using a regression discontinuity design instead of previous estimates that rely on difference-in-differences methodology or relatively weak instruments. Comparing LATE estimates for the United States and Canada, where very few students were affected by compulsory school laws, to the United Kingdom estimates provides a test as to whether instrumental variables (IV) returns to schooling often exceed ordinary least squares (OLS) because gains are high only for small and peculiar groups among the more general population. I find, instead, that the benefits from compulsory schooling are very large whether these laws have an impact on a majority or minority of those exposed.
Were There Regime Switches in U.S. Monetary Policy?
Authors: Sims Christopher A , Zha Tao
Published: March 2006

A multivariate regime-switching model for monetary policy is confronted with U.S. data. The best fit allows time variation in disturbance variances only. With coefficients allowed to change, the best fit is with change only in the monetary policy rule and there are three estimated regimes corresponding roughly to periods when most observers believe that monetary policy actually differed. But the differences among regimes are not large enough to account for the rise, then decline, in inflation of the 1970s and 1980s. Our estimates imply monetary targeting was central in the early 1980s, but also important sporadically in the 1970s.
Do Technological Improvements in the Manufacturing Sector Raise or Lower Employment?
Authors: Chang Yongsung , Hong Jay H
Published: March 2006

We find that technology's effect on employment varies greatly across manufacturing industries. Some industries exhibit a temporary reduction in employment in response to a permanent increase in TFP, whereas many more industries exhibit an employment increase in response to a permanent TFP shock. This raises serious questions about existing work that finds a labor productivity shock has a strong negative effect on employment. There are tantalizing and interesting differences between TFP and labor productivity. We argue that TFP is a more natural measure of technology because labor productivity reflects shifts in the input mix as well as in technology.
Politically Connected Firms
Authors: Faccio Mara
Published: March 2006

Examination of firms in 47 countries shows a widespread overlap of controlling shareholders and top officers who are connected with national parliaments or governments, particularly in countries with higher levels of corruption, with barriers to foreign investment, and with more transparent systems. Connections are diminished when regulations set more limits on official behavior. Additionally, I show that the announcement of a new political connection results in a significant increase in value.
On the Workings of a Cartel: Evidence from the Norwegian Cement Industry
Authors: Röller Lars-Hendrik , Steen Frode
Published: March 2006

Using data on prices, production, and exports, we are able to identify marginal costs as well as the effectiveness of the Norwegian cement industry cartel. We find that our marginal cost estimates are very much in line with the detailed cost accounting data. We show that the cement cartel has been ineffective because the sharing rule induces “overproduction” and exporting below marginal costs. It is consumers — not firms — who benefit from the sharing rule. The ineffectiveness of the cartel was becoming so large that domestic welfare of a merger to monopoly would be positive around 1968, which is when the merger actually took place! We also show that competition would have resulted in even higher welfare gains over the entire sample.