bluuebunny/crossref_metadata_2025 huggingface dataset:
Property Rights and Information
Authors: Wunderlich Gene
Published: June 2007

Information may be contained and governed by rules of property. Patents, copyrights and trademarks are forms of intellectual property which affect not only individual behavior, but the performance of an economy or society. Property, itself, can be viewed as an information system of right holders. So conceived, it is possible to cut across traditional legal compartments and examine the performance of the property system. The patent system is supposed to encourage inventiveness, but does it? The land title system is supposed to assure efficient transfer and firm possession of land, but does it? Ultimately, a property system, however conceived, must be measured in terms of broader issues of efficiency, equitability, privacy and freedom.
Will Information Technologies Help Learning?
Authors: Oettinger Anthony G. , Zapol Nikki
Published: June 2007

How to meet the varied learning needs of people of all ages is a burning question of public policy. In the past two decades faith in advanced technology as an answer peaked, then receded. The question remains, and so does the potential of technology. The question is worth asking only if it is granted that technology can serve learning at all. This is by no means self-evident. Our analysis shows that the manner in which technology can help learning is a far more complex question than most discussions of the subject have taken it to be. The continuing importance, in the long run, of basic research on learning will be self-evident to anyone who shares our faith in rationality and the fruitfulness of scientific search for knowledge. No-significant-difference findings, however, leave us with very little guidance from that quarter in the short term. What emerges as crucial in the short term is the question of betting on custom-tailored or on standardized learning situations. Given unfettered and economical access to the means for distributing information, varied private and public patterns of mediating learning can continue to evolve with changing preferences under whatever guidance advancing knowledge of learning can provide. Otherwise, talk of technology helping learning in a democratic society will be academic, in the most pejorative sense of the word.
Telecommunication and the City
Authors: Warthman Forrest
Published: June 2007

Telecommunication has historically been interrelated with transportation. Since railroads first used the telegraph as a scheduling aid, this interrelationship has affected almost every mode of point-to-point and broadcast telecommunication. For example, commercial radio and television depend on advertising which, in turn, is dependent on the transportation of goods to and from urban market centers. Telecommunication also serves as a substitute for travel, greatly increasing the speed of information consumption and processing and greatly broadening the availability of information and entertainment to individual homes and moving vehicles. As long distance communication continues to decrease in cost, major urban centers will become more international, since they are the focal points of travel. Telecommunication will also assist the outward spread of metropolitan areas, but social and transportation factors will constrain this outward movement.
The Development and Application of a Computerized Information-Processing Test Battery
Authors: Barrett Gerald V. , Alexander Ralph A. , Doverspike Dennis , Cellar Douglas , Thomas Jay C.
Published: June 2007

To bridge the gap between computerized testing and information-processing-based measurement, a battery of computerized information-processing-based ability and preference measures was developed. The information-processing and preference measures and a battery of paper-and-pencil tests were administered to 64 college students. Although the internal-consistency reliabilities of the computerized information-processing measures were adequate, test-retest reliabilities were lower than desirable for ability measures. The computerized information-processing measures possessed moderate convergent validity but had low correlations with traditional paper-and-pencil measures. Of the computerized preference measures, the most promising results were obtained with the Stimulus Pace measure. A major problem with the use of the computerized information-processing measures in applied settings would be administration time, as the battery took approximately 4 hours. In addition, problems with the stability of results over time and substantial practice effects suggest that even longer testing sessions would be required to obtain reliable measures. Although information-processing measures of short-term memory have, at best, low correlations with traditional intelligence tests, their ability to predict real-world tasks has yet to be sufficiently researched.
Dimensional Analysis of Rank-Order and Categorical Data
Authors: Skinner Harvey A. , Sheu Wen-Jenn
Published: June 2007

Skinner (1979) has described a generalized principal components model for classification research that assumes interval or quasi-interval data. First, a parsimonious set of typal dimensions is sought through a multiple replication design, and then relatively homogeneous subgroups are identified within this low dimensional space. The purpose of this paper is to describe preliminary transformations whereby the model may be extended to situations where the data are of either categorical or rank-order metric.
Personality Construct Similarity in Israel and the United States
Authors: Montag I. , Comrey Andrew L.
Published: June 2007

A translated version of the Comrey Personality Scales was administered to 185 male applicants for motor vehicle operator's license in Israel after special measures were taken to reduce response distortion. Total scores were computed for these subjects over each of the 40 homogeneous item subgroups that define the eight personality factors in the taxonomy underlying the Comrey Personality Scales. Factor analysis of the intercorrelations among these 40 subvariables resulted in substantial confirmation of seven of the eight hypothesized factors. Failure of the eighth factor to emerge may have been due to higher average scores and lower standard deviations for the item groups defining this particular factor, possibly caused by the special conditions under which the subjects were tested. The overall results of this study provide further evidence confirming the robustness of the taxonomy of personality traits underlying the Comrey Personality Scales across language and cultural boundaries.
Interpersonal Competence Instrument: Development and Preliminary Findings
Authors: Stricker Lawrence J.
Published: June 2007

A prototype measure of interpersonal competence, designed to measure effectiveness in dealing with other people, was developed-the Interpersonal Competence Instrument (ICI). The ICI is based on the videotape presentation of scenes of subordinates talking to a superior in a business setting. The examinee takes the role of the superior, his or her tape-recorded replies are assessed for effectiveness and originality, and his or her written judgments are evaluated for accuracy. In a pilot study (1) the three scores for the ICI were reliable, in terms of both interrater agreement and internal consistency; (2) the effectiveness and originality scores for replies were only moderately correlated with the accuracy scores for judgments, but the two replies scores were highly intercorrelated ; and (3) the correlations of the scores with background measures and other instruments, including measures of verbal ability and accuracy in social perception, generally supported the ICI's construct validity.
A Simple and Effective Method to Test the Dimensionality Axiom of the Rasch Model
Authors: van den Wollenberg Arnold L.
Published: June 2007

A simple method is introduced to test the dimensionality axiom in the Rasch model. The method consists of a suitable partitioning of the data set. This partitioning is based on the responses to some of the items being investigated. The items used for this purpose are called the external criterion items. data are presented indicating the effectiveness of the method in instances where the traditional test procedures fail.
The J-Index as a Measure of Nominal Scale Response Agreement
Authors: Janson Svants , Vegelius Jan
Published: June 2007

Some characteristics of Hubert's Г, as a measure of nominal scale response agreement, are shown, including the characteristic that in a contingency table with equal frequencies its value will normally not be zero. By making a slight modification of its definition, some of these characteristics can be eliminated. As another alternative, the J-index is suggested. It is closely related to Г but does not have the same problematic characteristics. Some asymptotic variance formulas for the J-index are given, together with a numerical example.
Robustness of Estimators of the Squared Multiple Correlation and Squared Cross-Validity Coefficient to Violations of Multivariate Normality
Authors: Drasgow Fritz , Dorans Neil J.
Published: June 2007

A monte carlo experiment was conducted to evaluate the robustness of two estimators of the population squared multiple correlation ( R2p) and one estimator of the population squared cross-validity coefficient ( R2 cv) to a common violation of multivariate normality. Previous research has shown that these estimators are approximately unbiased when independent and dependent variables follow a joint multivariate normal distribution. The particular violation of multivariate normality studied here consisted of a dependent variable that may assume only a few discrete values. The discrete dependent variable was simulated by categorizing an underlying continuous variable that did satisfy the multivariate normality condition. Results illustrate the attenuating effects of categorization upon R2p and R2cv. In addition, the distributions of sample squared multiple correlations and sample squared cross-validity coefficients are affected by categorization mainly through the attenuations of R 2P and R2cv. Consequently, the formula estimators of R2p and R2cv were found to be as accurate and unbiased with discrete dependent variables as they were with continuous dependent variables. Substantive researchers who use categorical dependent variables, perhaps obtained by rating scale judgments, can justifiably employ any of the three estimators examined here.
Standardized versus Unstandardized Regression Weights
Authors: Richards James M.
Published: June 2007

Behavioral scientists appear widely divided about the merits of standardized versus unstandardized regression weights. The present paper has therefore attempted to clarify the issue by illustrating how the two kinds of weights respond to the following circumstances: selection, or sampling variation, on the independent variable; presence of measurement error; changes in units of measurement; scales that are relative to norms rather than absolute; changes in test length; and selection on dependent and mediating variables. Standardized weights are invariant over changes in the units of measurement; unstandardized weights are invariant over selection on the independent variable (but only on the independent variable) and in the presence of dependent variable error. In general, however, the illustrated circumstances affected both kinds of weights, sometimes quite strongly. Therefore, neither kind of weight appears very robust, neither can be recommended unequivocally for comparing groups, and neither provides a panacea for overcoming problems of analyzing behavioral data.
Bounds on the k out of n Reliability of a Test, and an Exact Test for Hierarchically Related Items
Authors: Wilcox Rand R.
Published: June 2007

Consider an n-item multiple-choice test where it is decided that an examinee knows the answer if and only if he/she gives the correct response. The k out of n reliability of the test, Qk, is defined to be the probability that, for a randomly sampled examinee, at least k correct decisions are made about whether the examinee knows the answer to an item. The paper describes and illustrates how an extension of a recently proposed latent structure model can be used in conjunction with results in Sathe, Pradhan, and Shah (1980) to estimate upper and lower bounds on Qk. A method of empirically checking the model is discussed.
Sequential Testing for Selection
Authors: Weitzman R.A.
Published: June 2007

In sequential testing for selection, an applicant for school or work responds via a computer terminal to one item at a time until an acceptance or rejection decision can be made with a preset probability of error. The test statistic, as a function of item difficulties for standardization subgroups scoring within successive quantiles of the criterion, is an approximation of a Waldian probability ratio that should improve as the number of quantiles increases. Monte carlo simulation of 1,000 first-year college students under 96 different testing conditions indicated that a quantile number as low as four could yield observed error rates that are close to their nominal values with mean test lengths between 5 and 47. Application to real data, for which interpolative estimation of the quantile item difficulties was necessary, produced, with quantile numbers of four and five, even more accurate observed error rates than the monte carlo studies did. Truncation at 70 items narrowed the range of mean test lengths for the real data to between 5 and 19. Important for use in selection, the critical values of the test statistics are functions not only of the nominal error rates but also, alternatively, of the selection ratio, the base-rate success probability, and the success probability among selectees, which a test user is free to choose.
A Comparison of the Accuracy of Four Methods for Clustering Jobs
Authors: Zimmerman Ray , Jacobs Rick , Farr James
Published: June 2007

Four methods of cluster analysis were examined for their accuracy in clustering simulated job analytic data. The methods included hierarchical mode analysis, Ward's method, k-means method from a random start, and k-means based on the results of Ward's method. Thirty data sets, which differed according to number of jobs, number of population clusters, number of job dimensions, degree of cluster separation, and size of population clusters, were generated using a monte carlo technique. The results from each of the four methods were then compared to actual classifications. The performance of hierarchical mode analysis was significantly poorer than that of the other three methods. Correlations were computed to determine the effects of the five data set variables on the accuracy of each method. From an applied perspective, these relationships indicate which method is most appropriate for a given data set. These results are discussed in the context of certain limitations of this investigation. Suggestions are also made regarding future directions for cluster analysis research.
Infrastructure and the Rural—urban Divide in High-speed Residential Internet Access
Authors: Whitacre Brian E. , Mills Bradford F.
Published: June 2007

As residential Internet access in the United States shifts toward high-speed connections, a gap has emerged in rural high-speed access relative to urban high-speed access. Potential causes of this high-speed ``digital divide'' include rural—urban differences in people, place, and infrastructure. In this article, Current Population Survey data from 2000, 2001, and 2003 are combined with novel infrastructure data to determine the relative roles of these factors in the rural—urban divide. Bootstrapped decompositions of logit model results demonstrate that rural—urban differences in income and in network externalities, but not in infrastructure, are the dominant causes of the high-speed gap.
The Influence of Geopolitics and Foreign Policy on the U.S. and Canadian Media: An Analysis of Newspaper Coverage of Sudan's Darfur Conflict
Authors: Jang Hyun Kim  , Tuo-Yu Su  , Junhao Hong
Published: June 2007

Considerations of two facts, (1) Canadian media's strong dependence on the U.S. media, and (2) salient differences in foreign policy between the two nations (multilateralism— Canada, unilateralism—the U.S.) raise the question of whether Canadian major media's coverage reflects this difference.With content analysis and semantic network analysis of The New York Times (U.S.) and Globe and Mail (Canada) on the issue of Sudan's Darfur conflict, the authors found that (1) both newspapers focused on the facts of the conflict and Sudan's need of international aid, but (2) the Canadian newspaper's coverage focused more on multilateral/international help and people's suffering from the conflict than the U.S. media.Therefore, it may be concluded that geopolitical status and the U.S. media's influence exert a limited effect on the coverage of Canadian foreign policy: Canadian media have their own voice.
The Israeli—Hezbollah War of 2006: The Media as a Weapon in Asymmetrical Conflict
Authors: Kalb Marvin , Saivetz Carol
Published: June 2007

Based on content analysis of global media and interviews with many diplomats and journalists, this article describes the trajectory of the media from objective observer to fiery advocate, becoming in fact a weapon of modern warfare.The article also shows how an open society, Israel, is victimized by its own openness and how a closed sect, Hezbollah, can retain almost total control of the daily message of journalism and propaganda.
Effects of Contracting Out Engineering Services Over Time in a State Department of Transportation
Authors: Gen Sheldon , Kingsley Gordon
Published: June 2007

Perhaps the most prevalent form of privatization, in terms of incidents of its use, is contracting out for services. This is especially true in state departments of transportation (DOTs), which have seen a rapidly growing reliance on contracted professional services in recent years. With this growth has come a variety of managerial issues that speak to the efficacy of this mode of service production. In this article we identify and analyze these issues by first reviewing the literature on managing contracted professional services, with a focus on the experiences of DOTs. We complement the review with an in-depth, multicase examination of the experiences of one state DOT over the span of a decade, to better understand their changing conditions, motives, and impacts of large-scale contracting out. We conclude that problems associated with contracting out could be avoided with planned changes in procedures, organizational structures, and human resource demands.
Explaining Local Government Cooperation on Public Works
Authors: Leroux Kelly , Carr Jered B.
Published: June 2007

In recent years, analysts have begun to study cooperation on public services among local governments. These studies often have concluded that services with scale economies are likely candidates for shared service delivery. This article contributes to the emerging literature on this topic by examining interlocal service arrangements for 10 public works services in Michigan. Despite the fact that public works exhibit substantial scale economies, many local governments do not cooperate on these services. Empirical studies of local government contracting suggest four groups of factors that may help explain why local governments opt to collaborate on public services: local economic factors, characteristics of the communities in areas adjacent to the local government, demographic characteristics of the local government, and the influence of policy and planning networks. The authors use data on the service delivery arrangements from 468 general-purpose local governments in Michigan to examine the role played by the factors in explaining interlocal cooperation on public works.
Metropolitan Transportation Funding
Authors: Sciara Gian-Claudia , Wachs Martin
Published: June 2007

Recent efforts to implement regional-level funding sources in Las Vegas, Nevada; California's San Francisco Bay Area; and the state of Texas indicate that some states and regions are responding to transportation needs with institutional innovations that could allow greater metropolitan-level involvement in transportation finance. In light of the waning revenue-generating capacity of federal and state transportation user fees—historically, the main source of U.S. transportation funds—this article discusses different models for providing metropolitan planning organizations (MPOs) with revenue-generating authority, the conditions under which different models may be more or less attractive, and what characteristics may make some MPOs candidates for such innovation. Institutional and practical considerations are also examined. A view of current transportation finance and policy trends provides context for the discussion, as does an account of how MPOs and their transportation projects are funded today.
Lack of evidence for increased genetic loading for autism among families of affected females
Authors: Goin-Kochel Robin P. , Abbacchi Anna , Constantino John N. , Autism Genetic Resource Exchange Consortium
Published: June 2007

Both the broad and narrow phenotypes of autism have been consistently observed in family members of affected individuals. Additionally, autism spectrum disorders (ASDs) present four times more often in males than in females, for reasons that are currently unknown. In this study, we examined whether there were differences in familial loading of ASD among families of male versus female probands. Analyses were conducted with existing data from two distinct samples. The first sample contained 417 individuals with autism and Asperger's disorder and included information on the ASD diagnoses of their first- and second-degree relatives. The second sample consisted of 405 sibships participating in the Autism Genetic Resource Exchange, of which one or more siblings had an ASD diagnosis. Results from both samples did not suggest significant differences in the prevalence of ASD among relatives of affected males versus females.
Memory and generativity in very high functioning autism
Authors: Boucher Jill
Published: June 2007

JS is a highly able person with Asperger syndrome whose language and intellectual abilities are, and always have been, superior. The first part of this short article consists of JS's analytical account of his atypical memory abilities, and the strategies he uses for memorizing and learning. JS has also described specific difficulties with creative writing, which are outlined here. The second part of the article consists of an interpretation of the problems JS describes in terms of their implications for understanding the problems of generativity that contribute to the diagnostic impairments of imagination and creativity in autism.
Safety and clinical activity of the combination of 5-azacytidine, valproic acid, and all-trans retinoic acid in acute myeloid leukemia and myelodysplastic syndrome
Authors: Soriano Andres O. , Yang Hui , Faderl Stefan , Estrov Zeev , Giles Francis , Ravandi Farhad , Cortes Jorge , Wierda William G. , Ouzounian Souzanne , Quezada Andres , Pierce Sherry , Estey Elihu H. , Issa Jean-Pierre J. , Kantarjian Hagop M. , Garcia-Manero Guillermo
Published: June 2007

The combination of a DNA hypomethylating agent with a histone deacetylase inhibitor has synergistic antileukemia activity and may restore sensitivity to all-trans retinoic acid (ATRA). We conducted a phase 1/2 study of the combination of 5-azacitidine (5-AZA), valproic acid (VPA), and ATRA in patients with acute myeloid leukemia or high-risk myelodysplastic syndrome. 5-AZA was administered subcutaneously at a fixed dose of 75 mg/m2 daily for 7 days. VPA was dose-escalated and given orally daily for 7 days concomitantly with 5-AZA. ATRA was given at 45 mg/m2 orally daily for 5 days, starting on day 3. A total of 53 patients were treated. Their median age was 69 years (range, 5-84 years). The maximum tolerated dose of VPA in this combination was 50 mg/kg daily for 7 days. Dose-limiting toxicity was reversible neurotoxicity. The overall response rate was 42%. In previously untreated older patients, the response rate was 52%. Median number of courses to response was 1 (range, 1-3 courses). Median remission duration was 26 weeks, and median survival has not been reached. A significant decrease in global DNA methylation and induction of histone acetylation were achieved. VPA blood levels were higher in responders (P < .005). In conclusion, the combination studied is safe and has significant clinical activity. This clinical trial was registered at www.clinicaltrials.gov as no. NCT00326170.
The entire organization of transcription units on the Bacillus subtilis genome
Authors: Kobayashi Hirokazu , Akitomi Joe , Fujii Nobuyuki , Kobayashi Kazuo , Altaf-Ul-Amin Md , Kurokawa Ken , Ogasawara Naotake , Kanaya Shigehiko
Published: June 2007

Background

In the post-genomic era, comprehension of cellular processes and systems requires global and non-targeted approaches to handle vast amounts of biological information.

Results

The present study predicts transcription units (TUs) inBacillus subtilis, based on an integrated approach involving DNA sequence and transcriptome analyses. First, co-expressed gene clusters are predicted by calculating the Pearson correlation coefficients of adjacent genes for all the genes in a series that are transcribed in the same direction with no intervening gene transcribed in the opposite direction. Transcription factor (TF) binding sites are then predicted by detecting statistically significant TF binding sequences on the genome using a position weight matrix. This matrix is a convenient way to identify sites that are more highly conserved than others in the entire genome because any sequence that differs from a consensus sequence has a lower score. We identify genes regulated by each of the TFs by comparing gene expression between wild-type and TF mutants using a one-sided test. By applying the integrated approach to 11 σ factors and 17 TFs ofB. subtilis, we are able to identify fewer candidates for genes regulated by the TFs than were identified using any single approach, and also detect the known TUs efficiently.

Conclusion

This integrated approach is, therefore, an efficient tool for narrowing searches for candidate genes regulated by TFs, identifying TUs, and estimating roles of the σ factors and TFs in cellular processes and functions of genes composing the TUs.
External influences and priority-setting for anti-cancer agents: a case study of media coverage in adjuvant trastuzumab for breast cancer
Authors: Booth Christopher M , Dranitsaris George , Gainford M Corona , Berry Scott , Fralick Michael , Fralick John , Sue Joanna , Clemons Mark
Published: June 2007

Background

Setting priorities for the funding of new anti-cancer agents is becoming increasingly complex. The funding of adjuvant trastuzumab for breast cancer has brought this dilemma to the fore. In this paper we review external factors that may influence decision-making bodies and present a case study of media response in Ontario, Canada to adjuvant trastuzumab for breast cancer.

Methods

A comprehensive search of the databases of Canadian national and local newspapers and television was performed. Articles pertaining to trastuzumab in adjuvant breast cancer as well as 17 other anti-cancer drugs and indications were retrieved. The search period was from the date when individual trial results were announced to the date funding was made available in Ontario.

Results

During the 2.6 months between the release of the trastuzumab results to funding approval in Ontario, we identified 51 episodes of media coverage. For the 17 other drugs/indications (7 breast and 10 non-breast), the median time to funding approval was 31 months (range 14–46). Other recent major advances in oncology such as adjuvant vinorelbine/cisplatin for resected NSCLC and docetaxel for advanced prostate cancer received considerably less media attention (17 media reports for each) than trastuzumab. The median number of media reports for breast cancer drugs was 4.5 compared to 2.5 for non-breast cancer drugs (p = 0.56).

Conclusion

Priority-setting for novel anti-cancer agents is a complex process that tries to ensure fair use of constrained resources to fund therapies with the best evidence of clinical benefit. However, this process is subject to external factors including the influence of media, patient advocates, politicians, and industry. The data in this case study serve to illustrate the significant involvement one (or all) of these external factors may play in the debate over priority-setting.
Vitamin D and oestrogen receptor polymorphisms in developmental dysplasia of the hip and primary protrusio acetabuli – A preliminary study
Authors: Kapoor Birender , Dunlop Colin , Wynn-Jones Charles , Fryer Anthony A , Strange Richard C , Maffulli Nicola
Published: June 2007

We investigated the association of developmental dysplasia of the hip (DDH) and primary protrusion acetabuli (PPA) with Vitamin D receptor polymorphisms Taq I and Fok I and oestrogen receptor polymorphisms Pvu II and Xba I. 45 patients with DDH and 20 patients with PPA were included in the study. Healthy controls (n = 101) aged 18–60 years were recruited from the same geographical area. The control subjects had a normal acetabular morphology based on a recent pelvic radiograph performed for an unrelated cause. DNA was obtained from all the subjects from peripheral blood. Genotype frequencies were compared in the three groups. The relationship between the genotype and morphology of the hip joint, severity of the disease, age at onset of disease and gender were examined. The oestrogen receptor Xba I wild-type genotype (XX, compared with Xx and xx combined) was more common in the DDH group (55.8%) than controls (37.9%), though this just failed to achieve statistical significance (p = 0.053, odds ratio = 2.1, 95% CI = 0.9–4.6). In the DDH group, homozygosity for the mutant Taq I Vitamin D receptortallele was associated with higher acetabular index (Mann-Whitney U-test, p = 0.03). Pvu II pp oestrogen receptor genotype was associated with low centre edge angle (p = 0.07). This study suggests a possible correlation between gene polymorphism in the oestrogen and vitamin D receptors and susceptibility to, and severity of DDH. The Taq I vitamin D receptor polymorphisms may be associated with abnormal acetabular morphology leading to DDH while the Xba I oestrogen receptor XX genotype may be associated with increased risk of developing DDH. No such correlations were found in the group with PPA.
Placentation in dolphins from the Amazon River Basin: the Boto, Inia geoffrensis, and the Tucuxi, Sotalia fluviatilis
Authors: da Silva Vera MF , Carter Anthony M , Ambrosio Carlos E , Carvalho Ana F , Bonatelli Marina , Lima Marcelo C , Miglino Maria Angelica
Published: June 2007

A recent reassessment of the phylogenetic affinities of cetaceans makes it timely to compare their placentation with that of the artiodactyls. We studied the placentae of two sympatric species of dolphin from the Amazon River Basin, representing two distinct families. The umbilical cord branched to supply a bilobed allantoic sac. Small blood vessels and smooth muscle bundles were found within the stroma of the cord. Foci of squamous metaplasia occurred in the allanto-amnion and allantochorion. The interhemal membrane of the placenta was of the epitheliochorial type. Two different types of trophoblastic epithelium were seen. Most was of the simple columnar type and indented by fetal capillaries. However, there were also areolar regions with tall columnar trophoblast and these were more sparsely supplied with capillaries. The endometrium was well vascularised and richly supplied with actively secreting glands. These findings are consistent with the current view that Cetacea are nested within Artiodactyla as sister group to the hippopotamids.
HIV-associated adipose redistribution syndrome (HARS): etiology and pathophysiological mechanisms
Authors: Lichtenstein Kenneth , Balasubramanyam Ashok , Sekhar Rajagopal , Freedland Eric
Published: June 2007

Human immunodeficiency virus (HIV)-associated adipose redistribution syndrome (HARS) is a fat accumulation disorder characterized by increases in visceral adipose tissue. Patients with HARS may also present with excess truncal fat and accumulation of dorsocervical fat ("buffalo hump"). The pathophysiology of HARS appears multifactorial and is not fully understood at present. Key pathophysiological influences include adipocyte dysfunction and an excessive free fatty acid release by adipocyte lipolysis. The contributory roles of free fatty acids, cytokines, hormones including cortisol, insulin and the growth hormone-adipocyte axis are significant. Other potential humoral, paracrine, endocrine, and neural influences are also discussed.
Neutral genetic drift can alter promiscuous protein functions, potentially aiding functional evolution
Authors: Bloom Jesse D , Romero Philip A , Lu Zhongyi , Arnold Frances H
Published: June 2007

Background

Many of the mutations accumulated by naturally evolving proteins are neutral in the sense that they do not significantly alter a protein's ability to perform its primary biological function. However, new protein functions evolve when selection begins to favor other, "promiscuous" functions that are incidental to a protein's original biological role. If mutations that are neutral with respect to a protein's primary biological function cause substantial changes in promiscuous functions, these mutations could enable future functional evolution.

Results

Here we investigate this possibility experimentally by examining how cytochrome P450 enzymes that have evolved neutrally with respect to activity on a single substrate have changed in their abilities to catalyze reactions on five other substrates. We find that the enzymes have sometimes changed as much as four-fold in the promiscuous activities. The changes in promiscuous activities tend to increase with the number of mutations, and can be largely rationalized in terms of the chemical structures of the substrates. The activities on chemically similar substrates tend to change in a coordinated fashion, potentially providing a route for systematically predicting the change in one activity based on the measurement of several others.

Conclusion

Our work suggests that initially neutral genetic drift can lead to substantial changes in protein functions that are not currently under selection, in effect poising the proteins to more readily undergo functional evolution should selection favor new functions in the future.

Reviewers

This article was reviewed by Martijn Huynen, Fyodor Kondrashov, and Dan Tawfik (nominated by Christoph Adami).
Efficacy of and tolerance to mild induced hypothermia after out-of-hospital cardiac arrest using an endovascular cooling system
Authors: Pichon Nicolas , Amiel Jean Bernard , François Bruno , Dugard Anthony , Etchecopar Caroline , Vignon Philippe
Published: June 2007

Introduction

We evaluated the efficacy of and tolerance to mild therapeutic hypothermia achieved using an endovascular cooling system, and its ability to reach and maintain a target temperature of 33°C after cardiac arrest.

Methods

This study was conducted in the medical-surgical intensive care unit of an urban university hospital. Forty patients admitted to the intensive care unit following out-of-hospital cardiac arrest underwent mild induced hypothermia (MIH). Core temperature was monitored continuously for five days using a Foley catheter equipped with a temperature sensor. Any equipment malfunction was noted and all adverse events attributable to MIH were recorded. Neurological status was evaluated daily using the Pittsburgh Cerebral Performance Category (CPC). We also recorded the mechanism of cardiac arrest, the Simplified Acute Physiologic Score II on admission, standard biological variables, and the estimated time of anoxia. Nosocomial infections during and after MIH until day 28 were recorded.

Results

Six patients (15%) died during hypothermia. Among the 34 patients who completed the period of MIH, hypothermia was steadily maintained in 31 patients (91%). Post-rewarming 'rebound hyperthermia', defined as a temperature of 38.5°C or greater, was observed in 25 patients (74%) during the first 24 hours after cessation of MIH. Infectious complications were observed in 18 patients (45%), but no patient developed severe sepsis or septic shock. The biological changes that occurred during MIH manifested principally as hypokalaemia (< 3.5 mmol/l; in 75% of patients).

Conclusion

The intravascular cooling system is effective, safe and allows a target temperature to be reached fairly rapidly and steadily over a period of 36 hours.
CD4+ T lymphocyte subsets express connexin 43 and establish gap junction channel communication with macrophages in vitro
Authors: Bermudez-Fajardo Alexandra , Ylihärsilä Minna , Evans W Howard , Newby Andrew C , Oviedo-Orta Ernesto
Published: June 2007

Gap junction channels constructed of connexins (Cxs) are expressed by peripheral and secondary lymphoid organ-derived lymphocytes. These channels in the plasma membrane play key roles in a range of lymphocyte functions exemplified by the synthesis and secretion of Igs and cytokines and during transmigration across the endothelium. Most recently, their involvement in antigen cross-presentation has also been established. We report here for the first time the expression of mRNA and protein encoding Cx43 in mouse-derived CD4+ Th0, Th1, and Th2 lymphocyte subpopulations and demonstrate the establishment gap junction channel formation with primary macrophages in vitro. We show that this mode of direct communication is particularly favored in Th1-macrophage interactions and that LPS inhibits lymphocyte-macrophage cross-talk independently of the subset of lymphocyte involved. Our work suggests that gap junction-mediated communication can be modulated in the absence of specific antigenic stimulation. Therefore, a further mechanism featuring gap junction-mediated communication may be implicated in immune regulation.
Zebrafishrelatively relaxedmutants have a ryanodine receptor defect, show slow swimming and provide a model of multi-minicore disease
Authors: Hirata Hiromi , Watanabe Takaki , Hatakeyama Jun , Sprague Shawn M. , Saint-Amant Louis , Nagashima Ayako , Cui Wilson W. , Zhou Weibin , Kuwada John Y.
Published: June 2007

Wild-type zebrafish embryos swim away in response to tactile stimulation. By contrast, relatively relaxed mutants swim slowly due to weak contractions of trunk muscles. Electrophysiological recordings from muscle showed that output from the CNS was normal in mutants, suggesting a defect in the muscle. Calcium imaging revealed that Ca2+ transients were reduced in mutant fast muscle. Immunostaining demonstrated that ryanodine and dihydropyridine receptors, which are responsible for Ca2+ release following membrane depolarization, were severely reduced at transverse-tubule/sarcoplasmic reticulum junctions in mutant fast muscle. Thus, slow swimming is caused by weak muscle contractions due to impaired excitation-contraction coupling. Indeed, most of the ryanodine receptor 1b(ryr1b) mRNA in mutants carried a nonsense mutation that was generated by aberrant splicing due to a DNA insertion in an intron of the ryr1b gene, leading to a hypomorphic condition in relatively relaxed mutants. RYR1 mutations in humans lead to a congenital myopathy,multi-minicore disease (MmD), which is defined by amorphous cores in muscle. Electron micrographs showed minicore structures in mutant fast muscles. Furthermore, following the introduction of antisense morpholino oligonucleotides that restored the normal splicing of ryr1b, swimming was recovered in mutants. These findings suggest that zebrafish relatively relaxed mutants may be useful for understanding the development and physiology of MmD.
Geometric coupling in the wheel/rail contact formulations: A comparative study
Authors: Shabana A A , Rathod C
Published: June 2007

The wheel/rail contact conditions can be formulated using three- or two-dimensional theories. In the three-dimensional theory, four geometric parameters that describe the wheel and rail surfaces are introduced. The contact conditions, which are formulated in terms of these four surface parameters, are used to predict online the location of the points of contact between the wheels and rails. In the two-dimensional theory, which is used in most specialized railroad vehicle computer algorithms, the contact conditions are formulated in terms of only two geometric parameters that describe the wheel and rail profiles. These contact conditions are defined by a projection on a wheel plane that intersects the rail surface, thereby defining a curve on which the contact point lies. In this study, the planar and spatial contact conditions are implemented in a general multi-body system algorithm that can be used in the computer-aided analysis of railroad vehicle systems. This computer algorithm is used to compare between the results obtained using the planar and spatial contact conditions. The comparative study presented in this paper will be focused on two important specific issues related to the non-linear dynamics of railroad vehicles; the first is the prediction of the critical speed, while the second is the accuracy of predicting the location of the contact point using the two-dimensional theory. A two-dimensional formulation predetermines the contact plane and then searches for the contact points in that plane, while in the three-dimensional contact model all the surface parameters (coordinates of the contact points) are solved for simultaneously. In the contact formulations used in this paper, the kinematic and dynamic equations are expressed in terms of a mixed set of generalized and non-generalized coordinates. The non-generalized coordinates, which represent the surface parameters of the wheel and the rail, are used in the formulation of the kinematic and dynamic equations and also used to define geometric vectors such as the normal and tangent vectors as well as their derivatives at arbitrary points on the wheel and rail surfaces. The contact points are predicted online during the dynamic simulation by solving a set of non-linear algebraic equations instead of using look-up tables. A full vehicle model is used to obtain the numerical results in this comparative study. The results obtained based on the particular vehicle model used in this investigation show that the accuracy of predicting the vehicle critical speed is not affected when the simpler planar contact conditions are used. On the other hand, the comparison shows that there are differences between the dynamic force results obtained using the two methods due to small differences in the prediction of the locations of the contact points.
Complete shaking force and shaking moment balancing of RSS'R spatial linkages
Authors: Arakelian V H
Published: June 2007

This paper deals with a solution of the problem of shaking force and shaking moment balancing of the RSS'R spatial linkage. Design equations and techniques are proposed, making possible the dynamic substitution of the mass of the connecting coupler by two concentrated masses. By applying this approach, the dynamic model of the coupler represents a weightless link with two concentrated masses. This allows for the transformation of the problem of shaking force and shaking moment balancing of the spatial linkage into a problem of balancing rotating links carrying concentrated masses. A simplified approach is developed for computation and minimization of the input torque of the balanced linkage. The suggested solution is illustrated by a numerical example.
The effect of piston friction on engine block dynamics
Authors: Guzzomi A L , Hesterman D C , Stone B J
Published: June 2007

When developing vibration models, so as to reduce model complexity, it is typically expected that good prediction accuracy can be achieved by ignoring the complication of friction. In this paper, the significance of friction between the piston and cylinder on engine block dynamics is shown through simulation in both the time and frequency domains. Simulations and experiments indicate that large differences exist between model predictions for the engine block moment if this friction is not accounted for. This is especially true at low crankshaft rotational speeds when dynamic inertia effects are small. Experiments on a motored single cylinder engine at different average rotational speeds confirm the theory and very good tie-up with predictions is obtained. It is expected that these findings will also have implications for the torsional vibration of the engine.
Dynamic behaviour of planar rigid multi-body systems including revolute joints with clearance
Authors: Flores P , Ambrósio J , Claro J C P , Lankarani H M
Published: June 2007

This paper deals with a general methodology to assess the influence of the clearance size and the friction coefficient on the dynamic response of planar rigid multi-body systems including revolute joints with clearance. When there is a clearance in a revolute joint, impacts between the journal and the bearing can occur, and consequently, local deformations take place. The impact is internal and the response of the system is performed using a continuous contact force model. The friction effect because of the contact between joint elements is also included. The dynamic response of the systems is obtained numerically by solving the constraint equations and the contact-impact forces produced in the clearance joint, simultaneously with the differential equations of motion and a set of initial conditions. Numerical results for two simple mechanisms with revolute clearance joints are presented and discussed. In the present work, the clearance size and friction effects are analysed separately. Through the use of Poincaré maps, both periodic and chaotic responses of the systems are observed. The results predict the existence of the periodic or regular motion at certain clearance sizes and friction coefficients and chaotic or non-linear in other cases.
A curved beam element in the analysis of flexible multi-body systems using the absolute nodal coordinates
Authors: Sugiyama H , Suda Y
Published: June 2007

In this investigation, a curved beam element is developed for the analysis of large deformation of flexible multi-body systems using the absolute nodal coordinate formulation. In the existing beam element in this formulation, because the elastic forces are defined using the Green-Lagrange strain tensor as a volume element, locking phenomenon associated with the shear and cross-section deformation leads to erroneously stiffer bending characteristics. In order to circumvent this drawback, the Hellinger-Reissner variational principle is applied to modify the shear stress distribution, whereas the assumed strain method is employed to alleviate the locking associated with the cross-section deformation. The consistent tangent stiffness matrices are derived for the curved beam element and used with implicit integration methods. Numerical examples are presented in order to demonstrate the performance of the curved beam element developed in this investigation.
Effect of Solvent Polarity on the One-electron Oxidation of Cyclic Nitroxyl Radicals
Authors: Manda Sushma , Nakanishi Ikuo , Ohkubo Kei , Kawashima Tomonori , Matsumoto Ken-ichiro , Ozawa Toshihiko , Fukuzumi Shunichi , Ikota Nobuo , Anzai Kazunori
Published: June 2007

The one-electron oxidation potentials of two cyclic nitroxyl radicals determined by the differential pulse voltammetry and cyclic voltammetry were found to shift negatively with the increased solvent polarity.
An Efficient Heterogeneous Pd Catalyst for the Suzuki Coupling: Pd/Al2O3
Authors: Kudo Daisuke , Masui Yoichi , Onaka Makoto
Published: June 2007

PdII-loading alumina catalyst, which is simply prepared through impregnation of γ–alumina with Pd(OAc)2 followed by calcination in the air, shows a high catalytic activity for the Suzuki coupling of aryl bromides with arylboronic acids under phosphine ligand-free conditions. Only 0.25 mol % of palladium is sufficient for the promotion of the couplings in ethanol.