bluuebunny/crossref_metadata_2025 huggingface dataset:
Anti-angiogenesis therapy based on the bone marrow-derived stromal cells genetically engineered to express sFlt-1 in mouse tumor model
Authors: Hu M , Yang J-L , Teng H , Jia Y-Q , Wang R , Zhang X-W , Wu Y , Luo Y , Chen X-C , Zhang R , Tian L , Zhao X , Wei Y-Q
Published: November 2008

Background

Bone marrow-derived stromal cells (BMSCs) are important for development, tissue cell replenishment, and wound healing in physiological and pathological conditions. BMSCs were found to preferably reach sites undergoing the process of cell proliferation, such as wound and tumor, suggesting that BMSCs may be used as a vehicle for gene therapy of tumor.

Methods

Mouse BMSCs were loaded with recombinant adenoviruses which express soluble Vascular Endothelial Growth Factor Receptor-1 (sFlt-1). The anti-angiogenesis of sFlt-1 in BMSCs was determined using endothelial cells proliferation inhibition assay and alginate encapsulation assay. The anti-tumor effects of BMSCs expressing sFlt-1 through tail-vein infusion were evaluated in two mouse tumor metastases models.

Results

BMSCs genetically modified with Adv-GFP-sFlt-1 could effectively express and secret sFlt-1. BMSCs loaded with sFlt-1 gene could preferentially home to tumor loci and decrease lung metastases and prolong lifespan in mouse tumor model through inducing anti-angiogenesis and apoptosis in tumors.

Conclusion

We demonstrated that BMSCs might be employed as a promising vehicle for tumor gene therapy which can effectively not only improve the concentration of anticancer therapeutics in tumors, but also modify the tumor microenvironment.
A new scoring system in Cystic Fibrosis: statistical tools for database analysis – a preliminary report
Authors: Hafen GM , Hurst C , Yearwood J , Smith J , Dzalilov Z , Robinson PJ
Published: November 2008

Background

Cystic fibrosis is the most common fatal genetic disorder in the Caucasian population. Scoring systems for assessment of Cystic fibrosis disease severity have been used for almost 50 years, without being adapted to the milder phenotype of the disease in the 21stcentury. The aim of this current project is to develop a new scoring system using a database and employing various statistical tools. This study protocol reports the development of the statistical tools in order to create such a scoring system.

Methods

The evaluation is based on the Cystic Fibrosis database from the cohort at the Royal Children's Hospital in Melbourne. Initially, unsupervised clustering of the all data records was performed using a range of clustering algorithms. In particular incremental clustering algorithms were used. The clusters obtained were characterised using rules from decision trees and the results examined by clinicians. In order to obtain a clearer definition of classes expert opinion of each individual's clinical severity was sought. After data preparation including expert-opinion of an individual's clinical severity on a 3 point-scale (mild, moderate and severe disease), two multivariate techniques were used throughout the analysis to establish a method that would have a better success in feature selection and model derivation: 'Canonical Analysis of Principal Coordinates' and 'Linear Discriminant Analysis'. A 3-step procedure was performed with (1) selection of features, (2) extracting 5 severity classes out of a 3 severity class as defined per expert-opinion and (3) establishment of calibration datasets.

Results

(1) Feature selection: CAP has a more effective "modelling" focus than DA.

(2) Extraction of 5 severity classes: after variables were identified as important in discriminating contiguous CF severity groups on the 3-point scale as mild/moderate and moderate/severe, Discriminant Function (DF) was used to determine the new groups mild, intermediate moderate, moderate, intermediate severe and severe disease. (3) Generated confusion tables showed a misclassification rate of 19.1% for males and 16.5% for females, with a majority of misallocations into adjacent severity classes particularly for males.

Conclusion

Our preliminary data show that using CAP for detection of selection features and Linear DA to derive the actual model in a CF database might be helpful in developing a scoring system. However, there are several limitations, particularly more data entry points are needed to finalize a score and the statistical tools have further to be refined and validated, with re-running the statistical methods in the larger dataset.
The impact of SARS on hospital performance
Authors: Chu Dachen , Chen Ran-Chou , Ku Chia-Yu , Chou Pesus
Published: November 2008

Background

During the SARS epidemic, healthcare utilization and medical services decreased significantly. However, the long-term impact of SARS on hospital performance needs to be further discussed.

Methods

A municipal hospital in Taipei City was shut down for a month due to SARS and then became the designated SARS and infectious disease hospital for the city. This study collected the outpatient, inpatient and emergency service volumes for every year from April to March over four years. Average monthly service amount ± standard deviation were used to compare patient volume for the whole hospital, as well as the outpatient numbers accessing different departments. The ARIMA model of outpatient volume in the pre-SARS year was developed.

Results

The average monthly service volume of outpatient visits for the base year 2002 was 52317 ± 4204 visits per month, and number for 2003 and the following two years were 55%, 82% and 84% of the base year respectively. The average emergency service volume was 4382 ± 356 visits per month at the base year and this became 45%, 77% and 87% of the base year for the following three years respectively. Average inpatient service volume was 8520 ± 909 inpatient days per month at the base year becoming 43%, 81% and 87% of the base year for the following three years respectively. Only the emergency service volume had recovered to the level of a non-significant difference at the second year after SARS. In addition, the departments of family medicine, metabolism and nephrology reached the 2002 patient number in 2003. The ARIMA (2,1,0) model was the most suitable for outpatient volume in pre-SARS year. The MAPE of the ARIMA (2,1,0) model for the pre-SARS year was 6.9%, and 43.2%, 10.6%, 6.2% for following 3 years.

Conclusion

This study demonstrates that if a hospital is completely shut down due to SARS or a similar disease, the impact is longer than previous reported and different departments may experience different recover periods. The findings of this study identify subspecialties that are particularly vulnerable in an infectious disease designated hospital and such hospitals need to consider which subspecialties should be included in their medical structure.
Auditory assessment of patients with acute uncomplicated Plasmodium falciparum malaria treated with three-day mefloquine-artesunate on the north-western border of Thailand
Authors: Carrara Verena I , Phyo Aung P , Nwee Paw , Soe Ma , Htoo Hsar , Arunkamomkiri Jaruwan , Singhasivanon Pratap , Nosten François
Published: November 2008

Background

The use of artemisinin derivatives has increased exponentially with the deployment of artemisinin combination therapy (ACT) in all malarious areas. They are highly effective and are considered safe, but in animal studies artemisinin derivatives produce neurotoxicity targeting mainly the auditory and vestibular pathways. The debate remains as to whether artemisinin derivatives induce similar toxicity in humans.

Methods

This prospective study assessed the effects on auditory function of a standard 3-day oral dose of artesunate (4 mg/kg/day) combined with mefloquine (25 mg/kg) in patients with acute uncomplicated falciparum malaria treated at the Shoklo Malaria Research Unit, on the Thai-Burmese border. A complete auditory evaluation with tympanometry, audiometry and auditory brainstem responses (ABR) was performed before the first dose and seven days after initiation of the antimalarial treatment.

Results

Complete auditory tests at day 0 (D0) and day 7 (D7) were obtained for 93 patients. Hearing loss (threshold > 25 dB) on admission was common (57%) and associated with age only. No patient had a threshold change exceeding 10 dB between D0 and D7 at any tested frequency. No patient showed a shift in Wave III peak latency of more than 0.30 msec between baseline and D7.

Conclusion

Neither audiometric or the ABR tests showed clinical evidence of auditory toxicity seven days after receiving oral artesunate and mefloquine.
Flow cytometric immunophenotyping (FCI) of lymphoma: correlation with histopathology and immunohistochemistry
Authors: El-Sayed Abeer M , El-Borai Mohammad H , Bahnassy Abeer A , El-Gerzawi Shadia MS
Published: November 2008

Background

To evaluate the role of flow cytometric immunophenotyping (FCI) in diagnosis and characterization of lymphoma tissue specimens from Egyptian patients.

Methods

FCI using 2 and 3 color staining approaches, was performed on 50 fresh lymph nodes specimen from Cairo NCI patients with suspected lymphoma presenting with either localized or generalized lymphadenopathy.

FCI results were correlated with histopathologic as well as immunophenotypic[by immunohistochemistry (IHC)] findings.

Results

By FCI, cases were diagnosed as follows: 9(18%) reactive hyperplasia (RH), 32(64%) B-cell non-Hodgkin's lymphoma (B-NHL) [24 diffuse large (DLBCL), 2 follicular, 3 small lymphocytic, 2 mantle cell lymphoma and a case of T cell rich B cell lymphoma], 3 (6%) T cell NHL [2 peripheral T cell lymphoma and a case of anaplastic large cell lymphoma], 2(4%) Hodgkin's lymphoma (HL) while 4 (8%) were non-lymphomatous tumors (NLT). Light chain restriction (LCR) was detected in the 32 FCI diagnosed B-NHL. The overall concordance between FCI versus histopathology and IHC was 88%. The sensitivity and specificity of FCI in diagnosis of NHL was 94.9% and 100% respectively; in HL they were 40% and 100% respectively and in NLT, both sensitivity and specificity were 100% while for RH were 100% and 89.1% respectively.

Conclusion

FCI is a sensitive and specific method in diagnosis and classification of NHL as well as in detection of monoclonality. False negative results could be due to the presence of heterogeneous populations of lymphocytes in special types of lymphoma.
Virtual karyotyping with SNP microarrays reduces uncertainty in the diagnosis of renal epithelial tumors
Authors: Hagenkord Jill M , Parwani Anil V , Lyons-Weiler Maureen A , Alvarez Karla , Amato Robert , Gatalica Zoran , Gonzalez-Berjon Jose M , Peterson Leif , Dhir Rajiv , Monzon Federico A
Published: November 2008

Background

Renal epithelial tumors are morphologically, biologically, and clinically heterogeneous. Different morphologic subtypes require specific management due to markedly different prognosis and response to therapy. Each common subtype has characteristic chromosomal gains and losses, including some with prognostic value. However, copy number information has not been readily accessible for clinical purposes and thus has not been routinely used in the diagnostic evaluation of these tumors. This information can be useful for classification of tumors with complex or challenging morphology. 'Virtual karyotypes' generated using SNP arrays can readily detect characteristic chromosomal lesions in paraffin embedded renal tumors and can be used to correctly categorize the common subtypes with performance characteristics that are amenable for routine clinical use.

Methods

To investigate the use of virtual karyotypes for diagnostically challenging renal epithelial tumors, we evaluated 25 archived renal neoplasms where sub-classification could not be definitively rendered based on morphology and other ancillary studies. We generated virtual karyotypes with the Affymetrix 10 K 2.0 mapping array platform and identified the presence of genomic lesions across all 22 autosomes.

Results

In 91% of challenging cases the virtual karyotype unambiguously detected the presence or absence of chromosomal aberrations characteristic of one of the common subtypes of renal epithelial tumors, while immunohistochemistry and fluorescent in situ hybridization had no or limited utility in the diagnosis of these tumors.

Conclusion

These results show that virtual karyotypes generated by SNP arrays can be used as a practical ancillary study for the classification of renal epithelial tumors with complex or ambiguous morphology.
Osseointegration of zirconia implants: an SEM observation of the bone-implant interface
Authors: Depprich Rita , Zipprich Holger , Ommerborn Michelle , Mahn Eduardo , Lammers Lydia , Handschel Jörg , Naujoks Christian , Wiesmann Hans-Peter , Kübler Norbert R , Meyer Ulrich
Published: November 2008

Background

The successful use of zirconia ceramics in orthopedic surgery led to a demand for dental zirconium-based implant systems. Because of its excellent biomechanical characteristics, biocompatibility, and bright tooth-like color, zirconia (zirconium dioxide, ZrO2) has the potential to become a substitute for titanium as dental implant material. The present study aimed at investigating the osseointegration of zirconia implants with modified ablative surface at an ultrastructural level.

Methods

A total of 24 zirconia implants with modified ablative surfaces and 24 titanium implants all of similar shape and surface structure were inserted into the tibia of 12 Göttinger minipigs. Block biopsies were harvested 1 week, 4 weeks or 12 weeks (four animals each) after surgery. Scanning electron microscopy (SEM) analysis was performed at the bone implant interface.

Results

Remarkable bone attachment was already seen after 1 week which increased further to intimate bone contact after 4 weeks, observed on both zirconia and titanium implant surfaces. After 12 weeks, osseointegration without interposition of an interfacial layer was detected. At the ultrastructural level, there was no obvious difference between the osseointegration of zirconia implants with modified ablative surfaces and titanium implants with a similar surface topography.

Conclusion

The results of this study indicate similar osseointegration of zirconia and titanium implants at the ultrastructural level.
Confronting TB/HIV in the era of increasing anti‐TB drug resistance
Authors: Chakaya Jeremiah , Getahun Haileyesus , Granich Reuben , Havlir Diane
Published: November 2008

HIV associated TB is a major public health problem. In 2006, it was estimated that there were over 700,000 people who suffered from HIV associated TB, of whom about 200, 000 have died. The burden of HIV associated TB is greatest in Sub‐Saharan Africa where the TB epidemic is primarily driven by HIV. There has been steady progress made in reducing the burden of HIV in TB patients with an increasing number of TB patients tested for HIV and provided with cotrimoxazole preventive therapy (CPT) and anti‐retroviral treatment (ART). Less progress is being made to reduce the burden of TB in people living with HIV. The number of HIV infected persons reported to have been screened for TB was less than 1% while Isoniazid preventive therapy was reported to have been provided to less than 0.1% of eligible persons in 2006. A major push is urgently needed to accelerate the implementation of three important interventions. The three are Intensified TB Screening (ICF) among people living with HIV, the provision of Isoniazid Preventive Therapy (IPT) and TB Infection Control(IC). These interventions are best carried out by HIV control programmes which should therefore be encouraged to take greater responsibility in implementing these interventions.
The genesis of cartilage size and shape during development and evolution
Authors: Eames B. Frank , Schneider Richard A.
Published: November 2008

How do cartilaginous elements attain their characteristic size and shape?Two intimately coupled processes underlie the patterned growth of cartilage. The first is histogenesis, which entails the production of cartilage as a discrete tissue; the second is morphogenesis, which pertains to the origins of three-dimensional form. Histogenesis relies on cues that promote the chondrogenic differentiation of mesenchymal cells, whereas morphogenesis requires information that imbues cartilage with stage-specific (e.g. embryonic versus adult), region-specific (e.g. cranial versus appendicular) and species-specific size and shape. Previous experiments indicate that early programmatic events and subsequent signaling interactions enable chondrogenic mesenchyme to undergo histogenesis and morphogenesis, but precise molecular and cellular mechanisms that generate cartilage size and shape remain unclear. In the face and jaws, neural crest-derived mesenchyme clearly plays an important role, given that this embryonic population serves as the source of chondrocytes and of species-specific patterning information. To elucidate mechanisms through which neural crest-derived mesenchyme affects cartilage size and shape, we made chimeras using quail and duck embryos, which differ markedly in their craniofacial anatomy and rates of maturation. Transplanting neural crest cells from quail to duck demonstrates that mesenchyme imparts both stage-specific and species-specific size and shape to cartilage by controlling the timing of preceding and requisite molecular and histogenic events. In particular, we find that mesenchyme regulates FGF signaling and the expression of downstream effectors such as sox9 and col2a1. The capacity of neural crest-derived mesenchyme to orchestrate spatiotemporal programs for chondrogenesis autonomously, and to implement cartilage size and shape across embryonic stages and between species simultaneously, provides a novel mechanism linking ontogeny and phylogeny.
A methodology for the implementation of production assurance programmes in production plants
Authors: Barabady J , Aven T
Published: November 2008

There is an increased use of production assurance programmes in various industries, especially in the petroleum sector. The programme describes the production assurance activities necessary to fulfil the objectives, how they will be carried out, by whom, and when. The activities provide input to decisions regarding concept, design, manufacturing, construction, installation, operation, and maintenance. However, production assurance programmes have not yet been sufficiently developed for general use. It is a challenge to implement and apply such programmes in a practical setting. There is a lack of implementation guidelines. The purpose of the current paper is to meet these challenges; the paper describes and discusses a methodology that facilitates implementation of production assurance programmes in a production plant. The starting point is the offshore oil and gas industry, but the methodology and discussion are to a large extent general and could also be applied in other industries.
An approach for evaluating and selecting methods for risk and vulnerability assessments
Authors: Ford E P , Aven T , Røed W , Wiencke H S
Published: November 2008

This paper presents and discusses an approach for evaluating and selecting methods for risk and vulnerability assessments, covering both accidental events and security issues. The approach provides guidance on the selection of one specific, suitable method for various types of decision situations, reflecting different levels of potential consequences and associated uncertainties. The evaluation addresses the various stages of the risk assessment process, covering planning, execution, and use of the risk and vulnerability analyses. An example from information and communication technology (ICT) is used to illustrate the method.
Risk analysis of level crossing accidents based on systems control for safety
Authors: Kohda T , Fujihara H
Published: November 2008

Train protection systems in Japan such as signalling systems and level crossing protection systems have been mostly developed by the improvement of individual subsystems in their performance as well as specific post-accident measures to prevent similar accidents from happening again. However, level crossing accidents are still a major contributor to the total number of railway accidents. The importance of prior risk assessment of the total railway system increases, and risk management is to be desired for taking efficient measures without any degradation of the present safety level. This paper, with consideration of accident sequences and multilayered safety functions, presents a simple feasibility study for quantitative risk assessment of level crossing accidents with the aim of efficient and effective safety management for Japanese railway systems. Accident scenarios are described which initiate from a trapped motorcar through the failure of protection systems, including human actions. A simple phenomenal model is introduced in evaluating the accident occurrence probability. The positive correlation between the train velocity and accident frequency is derived, which can be considered acceptable as common sense.
Safety-barrier diagrams
Authors: Duijm N J
Published: November 2008

Safety-barrier diagrams and the related so-called ‘bow-tie’ diagrams have become popular methods in risk analysis. This paper describes the syntax and principles for constructing consistent and valid safety-barrier diagrams. The relation of safety-barrier diagrams to other methods such as fault trees and Bayesian networks is discussed. A simple method for quantification of safety-barrier diagrams is proposed. It is concluded that safety-barrier diagrams provide a useful framework for an electronic data structure that integrates information from risk analysis with operational safety management.
Events group risk importance by genetic algorithms
Authors: Podofillini L , Zio E
Published: November 2008

In this paper, the power of genetic algorithms is exploited to search for the most important groups of events in a risk/reliability model. To this end a two-objective search is formulated in which the decision variables are the groups of events, and the objectives are to maximize the importance of the groups, while minimizing their dimension. This allows the identification of the most important single events, couples of events, triplets, and so forth. Three case studies concerning network systems of increasing complexity are analysed.
Safety and inspection planning of older installations
Authors: Sørensen J D , Ersdal G
Published: November 2008

A basic assumption often made in risk- and reliability-based inspection planning is that a Bayesian approach can be used. This implies that probabilities of failure can be updated in a consistent way when new information (from inspections and repairs) becomes available. The Bayesian approach and a no-crack detection assumption imply that the inspection time intervals usually become longer and longer with time. For ageing platforms several small cracks should be expected to be observed according to the bath-tub curve development often assumed – implying an increased risk for crack initiation (and coalescence of small cracks) and increased crack growth. This should imply shorter inspection time intervals for ageing structures. Different approaches for updating inspection plans for older installations are proposed. The most promising method consists of increasing the rate of crack initiations at the end of the expected lifetime – corresponding to a bath-tub hazard rate effect. The approach illustrated is for welded steel details in platforms. Systems effects are considered, including the use of dependence between inspection and failure events in different components for inspection planning.
Maintenance decision rule with embedded online Bayesian change detection for gradually non-stationary deteriorating systems
Authors: Grall A , Fouladirad M
Published: November 2008

The aim of a condition-based maintenance policy is to manage the available online information about a component or a (sub)system, usually its degradation level, in order to improve the maintenance decision-making. This paper tackles the problem of maintenance decision rules for stochastically deteriorating systems that are subject to changes of their degradation rate during a life cycle. A well-suited control-limit maintenance decision rule is considered with an embedded online change detection algorithm. The maintenance decision and change detection parameters are optimized with respect to the same global maintenance cost and according to the available information about the degradation process. The obtained policy is compared with more classical control limit condition-based maintenance policies without online change detection. The use of the embedded online detection algorithm shows its efficiency especially for systems subject to significantly different degradation rates.
Modelling uncertainty in fault tree analyses using evidence theory
Authors: Limbourg P , Savić R , Petersen J , Kochs H-D
Published: November 2008

The Dempster—Shafer Theory of Evidence (DST) has been considered as an alternative to probabilistic modelling if both a large amount of uncertainty and a conservative treatment of this uncertainty are necessary. Both requirements are normally met in early design stages. Expert estimates replace field data and hardly any accurate test results are available. Therefore, a conservative uncertainty treatment is beneficial to assure a reliable and safe design. The present paper explores the applicability of DST which merges interval-based and probabilistic uncertainty modelling on a fault tree analysis from the automotive area. The system under investigation, an automatic transmission from the ZF AS Tronic series is still in the development stage. Expert estimates and the Monte Carlo propagation of the resulting mass function through the system model are used to obtain the uncertainty on the system failure probability. An exploratory sensitivity based on a non-specifity measure indicates which components contribute to the overall model uncertainty. The results are used to predict if the system complies with a given target failure measure.
A snapshot of methods and tools to assess safety integrity levels of high-integrity protection systems
Authors: Dutuit Y , Rauzy A B , Signoret J-P
Published: November 2008

In the oil industry, high-integrity protection systems tend to replace traditional safety systems. In this paper, a snapshot is provided of the methods and tools designed by the authors to evaluate efficiently safety integrity levels of high-integrity protection systems, as required by IEC 61508 and 61511 standards. These standards provide rigorous processes to build the safety of safety-instrumented systems. They are very efficient from an organizational point of view. However, difficulties arise with definitions and probabilistic calculations. To overcome these difficulties, the existing methods and tools were extended. These extensions are presented by means of simple examples. The focus is on the treatment of high-integrity protection systems working in low-demand mode (that is, with less than one demand per year according to the standards), e.g. systems such as high-integrity pressure protection systems. Some indications for safety systems working in continuous mode are given. Some practical conclusions are drawn from the various experiments performed. First, fault trees, when properly used, are very efficient for low-demand safety systems. Second, multi-phase Markov processes provide accurate results, even if only very small systems are tractable with this approach. Finally, behavioural modelling coupled with Monte Carlo simulation on Petri nets is both efficient and accurate. From the authors’ point of view, these approaches are simpler to handle than the informative formulae proposed in the present issue of IEC 61508 and 61511 standards.
Design allocation of multistate series-parallel systems for power systems planning: A multiple objective evolutionary approach
Authors: Taboada H A , Espiritu J F , Coit D W
Published: November 2008

This paper presents an extension and application of a recent developed multiple objective evolutionary algorithm to solve design allocation problems commonly found in the power systems area. The evolutionary algorithm introduced is called MOMS-GA, a multiobjective genetic algorithm developed to solve multistate design allocation problems. MOMS-GA works under the assumption that both the system and its components can experience more than two possible states of performance. MOMS-GA uses the universal moment generating function (UMGF) approach to evaluate the different reliability indices of the system. Therefore, system availability is represented by a multistate availability function which extends the traditional binary state availability. Three different design allocation problems commonly found in power systems planning are solved to show the performance of the algorithm. The multiobjective formulation considered in the first two examples corresponds to the maximization of system availability, minimization of system investment cost, and maximization of expected system capacity. In the third example the multiobjective formulation seeks to maximize system availability, minimize system investment cost, and minimize expected unsupplied demand.
Efficient Conjoint Choice Designs in the Presence of Respondent Heterogeneity
Authors: Yu Jie , Goos Peter , Vandebroek Martina
Published: November 2008

Random effects or mixed logit models are often used to model differences in consumer preferences. Data from choice experiments are needed to estimate the mean vector and the variances of the multivariate heterogeneity distribution involved. In this paper, an efficient algorithm is proposed to construct semi-Bayesian D-optimal mixed logit designs that take into account the uncertainty about the mean vector of the distribution. These designs are compared to locally D-optimal mixed logit designs, Bayesian and locally D-optimal designs for the multinomial logit model and to nearly orthogonal designs (Sawtooth (CBC)) for a wide range of parameter values. It is found that the semi-Bayesian mixed logit designs outperform the competing designs not only in terms of estimation efficiency but also in terms of prediction accuracy. In particular, it is shown that assuming large prior values for the variance parameters for constructing semi-Bayesian mixed logit designs is most robust against the misspecification of the prior mean vector. In addition, the semi-Bayesian mixed logit designs are compared to the fully Bayesian mixed logit designs, which take also into account the uncertainty about the variances in the heterogeneity distribution and which can be constructed only using prohibitively large computing power. The differences in estimation and prediction accuracy turn out to be rather small in most cases, which indicates that the semi-Bayesian approach is currently the most appropriate one if one needs to estimate mixed logit models.
Research Note—The Researcher as a Consumer of Scientific Publications: How Do Name-Ordering Conventions Affect Inferences About Contribution Credits?
Authors: Maciejovsky Boris , Budescu David V. , Ariely Dan
Published: November 2008

When researchers from different fields with different norms collaborate, the question arises of how name-ordering conventions are chosen and how they affect contribution credits. In this paper, we answer these questions by studying two disciplines that exemplify the two cornerstones of name-ordering conventions: lexicographical ordering (i.e., alphabetical ordering, endorsed in economics) and nonlexicographical ordering (i.e., ordering according to individual contributions, endorsed in psychology). Inferences about credits are unambiguous in the latter arrangement but imperfect in the former, because alphabetical listing can reflect ordering according to individual contributions by chance.

We contrast the fields of economics and psychology with marketing, a discipline heavily influenced by both. Based on archival data, consisting of more than 38,000 journal articles, we show that the three fields have different ordering practices. In two empirical studies with 351 faculty and graduate student participants from all three disciplines, as well as in a computer simulation, we show that ordering practices systematically affect and shape the allocation of perceived contributions and credit. Whereas strong disciplinary norms in economics and psychology govern the allocation of contribution credits, a more heterogeneous picture emerges for marketing. This lack of strong norms has detrimental effects in terms of assigned contribution credits.
Voluntary Quality Disclosure and Market Interaction
Authors: Guo Liang , Zhao Ying
Published: November 2008

Marketers disclose quality information directly to potential consumers using a variety of communication channels. This study investigates how competition may influence duopoly firms' incentive to voluntarily reveal quality information. We show that firms in competitive markets reveal less information than a monopoly firm. In addition, sequential disclosure leads to asymmetric equilibrium disclosure behavior: the disclosure leader reveals unambiguously less information than in the simultaneous disclosure case, whereas the follower ex ante reveals less (more) private information than that released by the leader or by the firms in the simultaneous case when the disclosure cost is sufficiently low (high). We also examine the equilibrium firm profits and social welfare. We demonstrate that there may be a U-shaped relationship between equilibrium monopoly profits (or social welfare under both monopoly and duopoly) and the disclosure cost. Moreover, in comparison to the simultaneous disclosure case, sequential disclosure can lead to increasingly softened competition, improving both firm profitability and social welfare.
Speaking Up to Higher-Ups: How Supervisors and Skip-Level Leaders Influence Employee Voice
Authors: Detert James R. , Treviño Linda K.
Published: November 2008

In this qualitative research, we enhance understanding of leader influences on employee voice perceptions by examining which leaders influence these perceptions and why these influences occur. We conducted 89 interviews in a high-tech multinational corporation with employees at multiple levels in two manufacturing and two R&D units that differed significantly on “speak up”-related items on a company-wide employee survey. Systematic analysis of the interview data led us to conclude that a broad spectrum of leaders from supervisors to senior managers influences individual employee voice perceptions in both direct and indirect ways. For example, informants referred to “skip-level leaders,” those leaders two to five levels above themselves, as reasons to view voice as risky or futile nearly as often as they referred to immediate bosses. We present evidence related to “how” and “why” these patterns of influence occur by reviewing the direct and indirect modes of influence identified and by outlining the managerial functions that provide occasions for skip-level leaders to have direct influences on employee voice perceptions. We also point to differences in the specific echelons of leadership that were most influential across the units studied. We propose that multilevel, multileader influences on voice perceptions result naturally from modern workflows, the essential functions performed by skip-level leaders, and deep-seated employee attitudes about authority in hierarchical organizations. We propose further that differences in which levels of skip-level leadership are most critical to employee voice perceptions in different units depend on which leaders have the power to handle strategic contingencies and to resolve key uncertainties within particular work environments. Finally, we delve into the theoretical implications of our findings to offer a set of research propositions that can be tested in future research. Collectively, our findings point to a complex and nuanced picture of multilevel leader influences on employee voice perceptions with important practical implications for management.
Soda-AQ delignification of poplar wood. Part 2: Further degradation of initially dissolved lignins
Authors: Venica Albert D. , Chen Chen-Loung , Gratzl Josef S.
Published: November 2008

Degraded lignin fragments dissolved in pulping liquor during the soda AQ pulping of poplar (Populus deltoides) wood with a flow through reactor were divided in two fractions. The first one (LF-1) was collected during the heating-up period (100°C until the final temperature t
max=170°C); the second one (LF-2) was collected at t
max with 60 min cooking time. These two liquors were then treated at 170°C for 70 min (leading to a liquor LF-1A) and 10 min (leading to a liquor LF-2A). By these post-treatments, pulping liquors of batch pulpings were simulated. From the four liquors, lignins were isolated and after purification the chemical and physical properties were characterized by Gel Permeation Chromatography (GPC: to obtain their molecular weight distribution), nitrobenzene oxidation, permanganate oxidation, and 13C NMR spectroscopy. By these means, the reaction mechanisms of dissolved and degraded lignin fragments in pulping liquors was elucidated and insight was gained concerning the effectiveness of the anthraquinone-anthrahydroquinone (AQ-AHQ) redox system using the corresponding batch lignin preparation as reference. The simulated batch fractions LF-1A, LF-2A, and true batch lignin preparations are similar. They have a high content of condensed arylpropane units. Among them, syringylpropane units are most severely degraded, in particular, etherified β-aryl ether bonds are cleaved to a great extent after dissolution in pulping liquor. The structure of the remaining degraded lignin fragments was changed seriously, particularly on their side chains. Oxidation and disproportionation reactions are typical. In the presence of fibers, xylans tend preferentially to simple deposition on fibers instead of grafting with the degraded lignin fragments. Dissolution of carbohydrates is not affected by higher alkali concentration at the end of the pulping, and the yield losses are caused by a better lignin removal.
Fenton-induced degradation of polyethylene glycol and oak holocellulose. A model experiment in comparison to changes observed in conserved waterlogged wood
Authors: Almkvist Gunnar , Persson Ingmar
Published: November 2008

Degradation of polysaccharides and polyethylene glycol have recently been observed in the wood of the Swedish war-ship Vasa. The signs of degradation are highly correlated to the presence of iron compounds, indicating iron initiated reactions of Fenton type. In order to test this hypothesis pure polyethylene glycol (PEG, Mw
=1500 u) and prepared oak holocellulose were oxidized by hyddroxyl radicals induced by Fenton's reagent [Fe(II)/H2O2] in aqueous solution. The changes in molar weight distribution (MWD) were analysed by MALDI-TOF mass spectrometry and size exclusion chromatography. The changes in MWD were consistent to random scission of the polymers according to statistical simulations. By NMR analysis the main PEG degradation products formed were identified as PEG molecules with different end groups: alcohols, aldehydes and formate esters; the latter hydrolyse to formic acid. The all over results show close similarities to the situation observed in the Vasa wood and strengthen the hypothesis of oxidative degradation initiated by iron compounds in the wood.
Analysis of acids and degradation products related to iron and sulfur in the Swedish warship Vasa
Authors: Almkvist Gunnar , Persson Ingmar
Published: November 2008

Aqueous wood extracts from the historic Swedish warship Vasa have been analyzed by 1H-NMR spectroscopy, ion chromatography, and matrix assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry as part of studies on the chemical degradation related to increased levels of iron and sulfur. The results show that low molecular organic acids have accumulated in the Vasa wood after the 1961 salvage. The increased acidity was found in a context of chemical degradation of the wood polymers and the conservation agent polyethylene glycol (PEG) in iron-rich parts of the timber. Formic, glycolic and oxalic acid are all possible end-products of oxidative degradation of wood polymers, whereas hydrolysis of acetyl groups in xylan may have contributed to increased concentrations of acetic acid. MALDI-TOF spectra of PEG displaced towards low-molecular PEG oligomers, as reported earlier, were accompanied by increased levels of formic acid, indicating oxidative degradation of PEG. PEG with a carboxylic acid end group (PEGC) was observed to a minor degree in the wood. However, analysis of stored conservation treatment solutions showed high concentrations of PEGC yielding significant contributions to the acidity during the 1960s conservation period. PEGC was probably formed as a result of microbial processes during the early conservation regime. Calculations using concentrations and well-established acidity constants show that oxalic and formic acid are the primary contributors to a low pH in the wood. The increased acidity in the interior of the wood was found in the absence of sulfur compounds but in a context of iron. The majority of the sub-samples with significant levels of sulfate in the surface region with a prospective sulfur oxidation, however, showed neither a decreased pH nor significant depolymerization. This indicates that oxidation pathways of organically bound sulfur do not necessarily produce strong acids, and thereby free protons, as the final product. These observations imply opposing effects of iron and reduced sulfur species, with iron acting as a initiator in oxidative reactions of Fenton type, whereas the reduced organic sulfur compounds may act as anti-oxidants.
Laboratory diagnosis and clinical manifestations of patients with dysfibrinogenemia / Laboratoriumsdiagnostik und klinische Manifestation der Dysfribrinogenämie
Authors: Miesbach Wolfgang
Published: November 2008

Hereditary dysfibrinogenemia is a rare clotting disorder due to a structural defect in the fibrinogen molecule that results in a tendency for bleeding and thrombosis, as well as obstetric complications. We describe the laboratory results and clinical manifestations for 50 patients with a diagnosis of dysfibrinogenemia. Various different laboratory measurements of fibrinogen were performed on samples from these patients, including fibrinogen (Clauss), heat fibrinogen precipitation according to Schulz and immunological fibrinogen. Fifty patients were found with dysfibrinogenemia (52% female; median age 52, range 9–89 years). The fibrinogen level according to Clauss was low, with a median of 51 mg/dL (range 15–86 mg/dL; normal range 150–450 mg/dL). Determination of other fibrinogen levels revealed normal results: heat fibrinogen precipitation according to Schulz, 240 mg/dL; and immunological fibrinogen, 244 mg/dL. The median reptilase time was longer than normal, at 55 s (normal 20 s). Some 50% of the patients reported a distinct bleeding tendency, mostly a tendency for hematoma (60%) and secondary bleeding (44%). Thirteen patients had thrombotic events, of which 54% were located arterially. Some 12% of the patients reported a tendency for bleeding and for thrombosis, whereas 19% had miscarriages, sometimes recurrent. We found that functional fibrinogen levels (Clauss) were generally lower in patients with bleeding manifestations (43 vs. 57 mg/dL in other patients).
Procalcitonin und seine Bedeutung für die Diagnose bakterieller Infektionen / Procalcitonin: Importance for the diagnosis of bacterial infections
Authors: Christ-Crain Mirjam , Schuetz Philipp , Huber Andreas R. , Müller Beat
Published: November 2008

Procalcitonin ist das Pro-Hormon von Calcitonin. Im Gegensatz zu Calcitonin, welches primär in der Schilddrüse gebildet wird, wird Procalcitonin bei einer bakteriellen Infektion im Körper von allen infizierten parenchymatösen Organen produziert.

Insbesondere bei der Diagnosestellung milder, lokalisierter oder beginnender Infektionen muss ein empfindliches Verfahren verwendet werden mit einer funktionellen Sensitivität, die idealerweise in dem Bereich gesunder Individuen messen kann (ca. 0,02 μg/L).

Procalcitonin konnte aufgrund seiner überlegenen diagnostischen Eigenschaften bei Atemwegsinfektionen die initiale Antibiotikaverschreibung sowie die Dauer der Antibiotikatherapie sowohl im stationären als auch im ambulanten Bereich in der Hausarztpraxis deutlich reduzieren (um 40–75%).

Obwohl prognostisch Procalcitonin anderen Infektionsmarkern überlegen ist, liegt jedoch eine eingeschränkte Aussagekraft bei der initialen Untersuchung bei Eintritt vor. Insbesondere der Verlauf von Procalcitonin kann aber über die Prognose Auskunft geben: sehr hohe und im Verlauf ansteigende Werte zeigen ein hohes Risiko für einen ungünstigen Verlauf an.

Trotz dieser Vorteile gegenüber anderen Infektionsmarkern ist Procalcitonin kein perfekter Marker für Infektionen. So kann es falsch hoch sein bei nicht-bakteriellen Erkrankungen (z.B. posttraumatisch, Malaria, schwerste Entzündungen, medulläres Schilddrüsenkarzinom) und bleibt bei streng lokalisierten Infektionen in einem relativ tiefen Bereich.

Wie jeder andere Biomarker sollte Procalcitonin deshalb immer im Kontext von Anamnese und klinischer Untersuchung interpretiert werden. Unter dieser Verantwortung kann mittels Procalcitonin die Diagnose einer bakteriellen Infektion deutlich verbessert werden.
Haben die Konzentrationen von Interleukin 6, Procalcitonin und CRP bei Intensivpatienten während des ersten Fieberanstieges eine prognostische Bedeutung? / Interleukin 6, procalcitonin and CRP levels during first increase of fever in intensive care patients
Authors: Fraunberger Peter , Holler Ernst , Parhofer Klaus G. , Walli Autar K. , Seidel Dietrich
Published: November 2008

Zur Untersuchung der klinischen Bedeutung von Biomarkern während intensivmedizinischer Betreuung wurden Interleukin-6 (IL-6), Procalcitonin (PCT) and C-reaktives Protein (CRP) bei 38 kritisch kranken Patienten während des ersten Fieberanstieges über 38,3°C gemessen. Bereits zum Zeitpunkt des Fieberanstieges konnten signifikant höhere IL-6-Konzentrationen bei Patienten verzeichnet werden, welche die Erkrankung nicht überlebten. Insbesondere IL-6-Werte >1000 pg/mL waren mit sehr hoher Mortalität assoziiert. Sensitivität, Spezifität, positive and negative Vorhersagewerte zur Beurteilung der Mortalität waren für IL-6 höher als für PCT und CRP. ROC-Analysen zeigten die höchste prognostische Wertigkeit für IL-6-Konzentrationen im Vergleich zu PCT und CRP-Konzentrationen. Diese Daten unterstützen die Hypothese, dass eine deutlich erhöhte IL-6-Konzentration bereits zum Zeitpunkt des ersten Fieberanstieges ein guter Frühmarker zur Erkennung von Hochrisikopatienten mit hoher Mortalität ist.
Update on Injury Trends in Alpine Skiing
Authors: Johnson Robert J. , Ettlinger Carl F. , Shealy Jasper E.
Published: November 2008

Over the 34 years from December of 1972 to April of 2006 the authors evaluated prospectively 18,696 injuries sustained by 17,193 skiers and reported to the injury clinic operated in the base lodge of a medium-sized northern Vermont ski area. Data from a total of 3966 randomly selected uninjured controls were also collected. Over the period approximately 6,780,940 skier-visits were accrued by the area. The overall injury rate dropped by 55 % over the 34 years of the study to 1.9 injuries per thousand skier visits. Among lower extremity injuries only tibial plateau fractures produced a statistically significant negative trend. Twist-related lower leg injuries improved the most with a net reduction of 87 % over 34 years. Bending-related lower leg injuries showed no improvement in the last half of the study. Overall, the incidence of knee ligament injuries changed very little. However, the incidence of minor to moderate sprains diminished by 77 % while severe knee sprains, usually involving the anterior cruciate ligament, increased by 268 % through the early 90s. Since then there has been a 37 % improvement. Among upper body injuries only clavicle and humerus fractures produced statistically significant negative trends.