bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamic Characteristics and Dynamic Instability of Magnetorheological Material-based Adaptive Beams
Authors: Yeh Zi-Fong , Shih Yan-Shin
Published: July 2006

The theoretical model of a simply supported magnetorheological material-based adaptive beam under an axial harmonic load is modified based on the DiTaranto sandwich beam theory for a symmetric three-layer beam. A differential equation for extensional motion of a freely vibrating beam is derived. This study considers an axially forced vibration of asymmetric magnetorheological material-based beam and derives a sixth-order equation for transverse motion. The derived governing equation of motion is then simplified using Galerkin’s method to yield the Mathieu equation. The formulae for buckling load, natural frequency, and loss factor of a simply supported adaptive beam are developed. Numerical results demonstrated from the formulae are highly consistent with the published results. The incremental harmonic balance (IHB) method is utilized to study the regions of dynamic instability, which are demonstrated graphically. The dynamic responses of the adaptive beam are assessed via the fourth-order Runge-Kutta method. The effects of magnetic field, core thickness ratio and beam length on the buckling load, natural frequency, loss factor, and dynamic instability are also presented. The influence of the static load parameter factor on natural frequency, loss factor, and dynamic instability is considered.
Assessing Risk and Opportunity in Conflict Studies
Authors: Poe Steven C. , Rost Nicolas , Carey Sabine C.
Published: July 2006

Over the past two decades, substantial progress has been made toward a theoretical understanding of why physical integrity abuses are committed. Unfortunately, these theoretical developments have been devoid of much practical application. In this article, the authors explore the feasibility of risk assessment in the study of these human rights. Borrowing an approach by Gurr and Moore, they construct a risk assessment vehicle that uses existing models and data to develop expectations about future increases and decreases in human rights abuses. Their results indicate that we can isolate a set of cases that are at a higher risk of experiencing increased human rights abuse in the following year, as well as those that are ripe for better protection of human rights. The authors expect these risk and opportunity assessments to be of interest to students of conflict and peace studies, as well as to human rights activists and policy makers.
Sensitivity Analysis of Empirical Results on Civil War Onset
Authors: Hegre Håvard , Sambanis Nicholas
Published: July 2006

In the literature on civil war onset, several empirical results are not robust or replicable across studies. Studies use different definitions of civil war and analyze different time periods, so readers cannot easily determine if differences in empirical results are due to those factors or if most empirical results are just not robust. The authors apply a methodology for organized specification tests to check the robustness of empirical results. They isolate causes of variation in empirical results by using the same definition of civil war and analyzing the same time period while systematically exploring the sensitivity of eighty-eight variables used to explain civil war in the literature. Several relationships with the onset of civil wars prove robust: large population and low income levels, low rates of economic growth, recent political instability and inconsistent democratic institutions, small military establishments and rough terrain, and war-prone and undemocratic neighbors. Variables representing ethnic difference in the population are robust only in relation to lower level armed conflict.
Not Only Whether but Whom
Authors: Quackenbush Stephen L.
Published: July 2006

Although in reality, states simultaneously pursue direct and extended deterrence, extant theories of deterrence have considered direct and extended deterrence situations separately. Furthermore, extended deterrence theories have not modeled all three actors in extended deterrence situations. To overcome these limitations in the literature, the author develops the three-party extended deterrence game and analyzes it with both complete and incomplete information, allowing conclusions to be drawn regarding deterrence and the related areas of alliance reliability and war expansion. For example, the findings indicate that deterrence is most likely to succeed when the alliance between Defender and Protégé is reliable. However, neither Defender nor Protégé wishes to be a more reliable ally than the other; if there is an asymmetry in reliability, Challenger will chose the more reliable state to attack in order to avoid a multilateral war. This counterintuitive conclusion was only reached by considering all three actors in extended deterrence.
English Language Instruction in the Philippine Basic Education Program
Authors: Vizconde Camilla
Published: July 2006

The study discusses the dynamics English language instruction in the Philippine basic education curriculum. Although English enjoyed immense popularity as early as 1900s during the American entry to the country, its role in Philippine education has transformed gradually as the country undergoes political, social and economic reconstruction in the past decades. This paper analyzes the English instruction in secondary education in the framework of systems thinking. It discusses in detail how English instruction in the Philippines can be understood in the context of its role in education.
Naturalistic Decision Making and Organizations: Reviewing Pragmatic Science
Authors: Gore Julie , Banks Adrian , Millward Lynne , Kyriakidou Olivia
Published: July 2006

This article examines the similarities and differences between the traditions of naturalistic decision making and organizational decision making. Illustrative examples of successful NDM inquiry in healthcare organizations are reviewed, highlighting an area where these two pragmatic research paradigms overlap. Not only do researchers in these areas aim to improve our understanding of decision making, they provide practical and realistic alternatives to laboratory-based research on decision making. The article presents a number of propositions for future research on NDM and organizations.
Shared Situation Awareness as a Contributor to High Reliability Performance in Railroad Operations
Authors: Roth Emilie M. , Multer Jordan , Raslear Thomas
Published: July 2006

Cooperative strategies of individuals within a distributed organization can contribute to increased efficiency of operations and safety. We examine these processes in the context of a particular work domain: railroad operations. Analyses revealed a variety of informal cooperative strategies that railroad workers have developed that span across multiple railroad crafts including roadway workers, train crews, and railroad dispatchers. These informal, proactive communications foster shared situation awareness across the distributed organization, facilitate work, and contribute to the overall efficiency, safety, and resilience to error of railroad operations. We discuss design implications for leveraging new digital technologies and location-finding systems to more effectively support these informal strategies, enhance shared situation awareness, and promote high reliability performance.
Extending Naturalistic Decision Making to Complex Organizations: A Dynamic Model of Situated Cognition
Authors: Shattuck Lawrence G. , Miller Nita Lewis
Published: July 2006

Naturalistic decision making (NDM) has become established as a methodological and theoretical perspective. It describes how practitioners actually make decisions in complex domains. However, NDM theories tend to focus on the human agents in the system. We extend the NDM perspective to include the technological agents in complex systems and introduce the dynamic model of situated cognition. We describe the general characteristics of NDM and the field of situated cognition, and provide a detailed description of our model. We then apply the model to a recent accident in which a US Navy submarine (USS Greeneville) collided with a Japanese fishing vessel ( Ehime Maru). The discussion of the accident illustrates how decisions made are often a result of the interaction between a variety of technological and human agents and how errors introduced into the complex system can propagate through it in unintended ways. We argue that the dynamic model of situated cognition can be used to describe activities in virtually any complex domain.
Discovering Healthcare Cognition: The Use of Cognitive Artifacts to Reveal Cognitive Work
Authors: Nemeth Christopher , O’Connor Michael , Klock P. Allan , Cook Richard
Published: July 2006

Healthcare systems, especially hospital operating room suites, have properties that make them ideal for the study of the cognitive work using the naturalistic decision-making (NDM) approach. This variable, complex, high-tempo setting provides a unique opportunity to examine the ways that clinicians plan, monitor, and cope with the irreducible uncertainty that underlies this work domain. As frontline managers, anesthesia coordinators plan and manage anesthesia assignments for surgical procedures. As frontline managers, coordinators develop and use cognitive artifacts to distribute cognition across time and among members of the acute care staff. Examination of these cognitive artifacts and their use reveals the hidden subtleties of the coordinators’ work. The use of NDM methods including cognitive artifact analysis to understand cognitive work generates insights that extend beyond the operator level to the study of team-level cognition. Results can be used to create computer-based artifacts that aid individual and team cognition.
Naturalistic Decision Making and Organizational Learning in Nuclear Power Plants: Negotiating Meaning Between Managers and Problem Investigation Teams
Authors: Carroll John S. , Hatakenaka Sachi , Rudolph Jenny W.
Published: July 2006

We explore the linkages between naturalistic decision making, which examines decisions in context, and team and organizational learning, which examines how feedback from decisions affects context. We study 27 problem investigation teams in three nuclear power plants, a setting that combines complex team decisions with organizational learning. Further, managers who commission the teams and receive team reports are a key aspect of context for the teams and a critical conduit for organizational learning and change. Questionnaires were given to both team members and manager recipients of written team reports, and team reports were coded for qualities of their analyses and recommendations. We find that team members value reports in which the team discovered causes or lessons that could be used in other contexts, whereas managers appreciate reports with logical corrective actions from teams with investigation experience. Teams with managers or supervisors as team members are better able to reach shared understanding with their manager customers. Teams with more diverse departmental backgrounds produce deeper and more creative analyses. Teams need access to information and analytical skills in order to learn effectively, but they also need management support and boundary-spanning skills in order to diffuse their learning.
Representations of Use and Practice-Bound Imaginaries in Automating the Safety of the Elderly
Authors: Hyysalo Sampsa
Published: July 2006

The present paper examines how representations of prospective use became designed in a novel healthcare technology for elderly people. The case lends support to studies arguing that explicit investigations provide only a part of the representations of prospective use for technology design. It draws attention to a source of representations of use that is at once obvious and under-explored: the professional traditions of developers of technology. To examine this, the concept of practice-bound imaginary is introduced as an alternative to existing terms, such as technological frame. The concept enables better understanding of the interplay of multiple professional practices, the orientation of technology projects and the dynamics of how traditions affect the ideas about prospective use. These analytical possibilities were needed in the case-analysis, as the project was informed by several professional practices, each with their own sets of representations of use. Moreover, in many cases the representations of use were at once representations of viability, medical validity or manufacturability. They were often also inter-animated by adjoining representations from the same practice and compatible assumptions from other practices. Use was not only planned, configured or implicitly assumed, but also was inscribed by the models for conducting design, routine procedures and the messy interactions between people and materials. Designers themselves became aware of the implications of their solutions only after the artefact was reshaped by the resistance of the eventual users and refusers of the device.
Strain-rate Dependence of Interlaminar Stress Fields in the Vicinity of Free Edges of AS4-PEEK Composite Laminates Under Uniaxial Tension
Authors: Ding Shurong , Tong J. W. , Shen M. , Li H. Q. , Huo Y. Z.
Published: July 2006

Using finite element program generator (FEPG) of Beijing Feijian Software Corporation, a relative finite element procedure is developed for the three-dimensional viscoplasticity model which can characterize well the nonlinear behavior and strain-rate dependence behavior of thermoplastic composite, AS4-PEEK. Interlaminar stresses of angle-ply laminates []s for different strain rates under uniaxial tension are calculated. The effects of the variation of strain rates on interlaminar stresses in the vicinity of free edges of AS4-PEEK composite laminates are investigated. From the three-dimensional plots of the interlaminar stresses, it can be seen that distant free-edge effects and end-edge effects exist in the angle-ply laminates []s. The interlaminar stresses in free-edges and two ends increase with increasing strain rates. The extents to which the strain rates affect interlaminar stresses are depicted.
The Basal Ganglia in Human Learning
Authors: Seger Carol A.
Published: July 2006

For many years, the basal ganglia were described in anatomy courses as strictly motor structures. Certainly, some of the most obvious and debilitating symptoms shown by persons with basal ganglia disorders are problems in motor control. However, the basal ganglia are not limited to motoric aspects of behavior: recent research shows that they are involved in most areas of cognitive and emotional functioning, consistent with their anatomical connections with all areas of the cortex. This review will focus on the roles of the basal ganglia in human learning, particularly sequence learning and category learning. Current areas of research that are discussed include the differing roles of different basal ganglia regions, patterns of interaction between the cortex and basal ganglia, differences in positive and negative association learning, effects of dopaminergic medication on learning, whether basal ganglia–mediated learning is implicit or explicit, and how the basal ganglia learning systems interact with other learning systems, particularly within the medial temporal lobe.
Gene Expression Profiling in Schizophrenia and Related Mental Disorders
Authors: Iwamoto Kazuya , Kato Tadafumi
Published: July 2006

The etiology and pathophysiology of schizophrenia and related mental disorders such as bipolar disorder and major depression remain largely unclear. Recent advances in mRNA profiling techniques made it possible to perform genome-wide gene expression analysis in a hypothesis-free manner. It was thought that this large-scale data mining approach would reveal unknown molecular cascades involved in mental disorders. Contrary to this initial expectation, however, DNA microarray results in psychiatric fields have been notoriously discordant. Here the authors review the findings of DNA microarray analysis, focusing on systematic gene expression changes in schizophrenia, as well as alterations in the expression of specific genes, that have been reported and replicated. The authors also address the probable causes for the discordance among studies, possible ways to solve the problem, and their preferred approach for data interpretation.
Mitochondria at the Synapse
Authors: Ly Cindy V. , Verstreken Patrik
Published: July 2006

Synapses are packed with mitochondria, complex organelles with roles in energy metabolism, cell signaling, and calcium homeostasis. However, the precise mechanisms by which mitochondria influence neurotrans mission remain undefined. In this review, the authors discuss pharmacological and genetic analyses of synaptic mitochondrial function, focusing on their role in Ca2+ buffering and ATP production. Additionally, they will summarize recent data that implicate synaptic mitochondria in the regulation of neurotransmitter release during intense neuronal activity and link these findings to the pathogenesis of neurodegenerative diseases that feature disrupted synaptic mitochondria, including amyotrophic lateral sclerosis and hereditary spastic paraplegia.
Multisensory Processing in Sensory-Specific Cortical Areas
Authors: Macaluso Emiliano
Published: July 2006

The anatomical organization of the brain is such that incoming signals from different sensory modalities are initially processed in anatomically separate regions of the cortex. When these signals originate from a single event or object in the external world, it is essential that the inputs are integrated to form a coherent representation of the multisensory event. This review discusses recent data indicating that the integration of multisensory signals relies not only on anatomical convergence from sensory-specific cortices to multi-sensory brain areas but also on reciprocal influences between cortical regions that are traditionally considered as sensory-specific. These findings highlight integration mechanisms that go beyond traditional models based on a hierarchical convergence of sensory processing.
Is Huntington's a Glutamine Storage Disease?
Authors: Brusilow William S. A.
Published: July 2006

Huntington's disease is a neurological disorder caused by the expansion of a polyglutamine tract in the protein huntingtin. Several other neurological diseases also result from the expansion of polyglutamine regions in different proteins. Despite intense efforts, no definitive biochemical or physiological role for huntingtin has been described, nor has a function been assigned to the polyglutamine region in unaffected individuals. This article presents the hypothesis that polyglutamine expansions within huntingtin and other polyglutamine proteins provide a function in and of themselves. Incorporating multiple glutamine residues into a protein during synthesis, and releasing them during protein turnover, may represent a means of minimizing interruptions in brain levels of glutamine and glutamate during periods of malnutrition. The number and variety of different proteins containing polyglutamine expansions can be interpreted as a series of evolutionary “experiments” toward a nontoxic form for glutamine storage.
Assessment of Working Memory in Children With Attention-Deficit/Hyperactivity Disorder
Authors: Messina Lucinete de Freitas , Tiedemann Klaus Bruno , de Andrade Enio Roberto , Primi Ricardo
Published: July 2006

Objective: This research investigated the cognitive abilities and the working memory in children and youngsters with three different types of attention-deficit/hyperactivity disorder (ADHD): (a) mainly with attention-deficit, (b) hyperactive and impulsive, and (c) combined. Method: A computerized test called Infant Cognitive Abilities Test, which measures five cognitive abilities based on the Cattell-Horn-Carroll model, was used. Thirty-two children from both sexes, aged 7 to 15 years, from the Hospital das Clínicas, suffering from ADHD and a control group with 30 children from a state elementary school (first through eighth grades) were submitted to the test. Results: The results showed that there were significant differences with regard to the reaction time of the working memory of the different types of ADHD. Conclusion: Children suffering from ADHD had high test scores for the visual memory items of the test, when compared with the results in the auditory memory items.
Driving Anger and Driving Behavior in Adults With ADHD
Authors: Richards Tracy L. , Deffenbacher Jerry L. , Rosén Lee A. , Barkley Russell A. , Rodricks Trisha
Published: July 2006

Objective: This study assesses whether anger in the context of driving is associated with the negative driving outcomes experienced by individuals with ADHD. Method: ADHD adults ( n = 56) complete measures of driving anger, driving anger expression, angry thoughts behind the wheel, and aggressive, risky, and crash-related behavior. Results are compared to two non-ADHD control groups: one from the same community as the ADHD sample ( n = 106) but that did not complete all instruments and the other from college students ( n = 432) who completed all instruments. Results: ADHD participants report more driving anger and aggressive expression through the use of their vehicle and less adaptive and constructive anger expression than their non-ADHD peers. Adult ADHD drivers rate themselves as more angry, risky, and unsafe drivers and report experiencing more losses of concentration and vehicular control than college students. Conclusion: Results are discussed with regard to drivingrelated problems for drivers with ADHD.
The Prevalence of ADHD Among Primary School Children in an Arabian Society
Authors: Bener Abdulbari , Qahtani Razna Al , Abdelaal Ibrahim
Published: July 2006

Objective: The aim of this study is to identify Attention Deficit Hyperactivity Disorders among primary school children in the State of Qatar. Method: A cross-sectional descriptive study is conducted from March 2004 to February 2005. A total of 2,000 primary school students, ages 6 to 12, are selected, and 1,541 students (77.1%) give consent to participate in this study. An Arabic questionnaire is used to collect the sociodemographic variables and a standardized Arabic version of the Conners’ Classroom Rating Scale for ADHD symptoms. Of the students surveyed, 51.7% are males and 48.3% females. Results: The data reveal that 112 boys (14.1%) and 33 girls (4.4%) scored above the cutoff for ADHD symptoms, thus giving an overall prevalence of 9.4%. Children who have a higher score for ADHD symptoms have school performance poorer than those with lower scores ( p = .003). Conclusion: The study reveals that ADHD is found to be a common problem among school children in Qatar.
Hemispheric Functioning in Children With Subtypes of Attention-Deficit/Hyperactivity Disorder
Authors: Rolfe Mei Hsin Suzanne , Hausmann Markus , Waldie Karen E.
Published: July 2006

Objective: The authors investigated line bisection performance in children with Attention-Deficit/Hyperactivity Disorder (AD/HD) subtypes. Previous research with neurotypical children found a rightward bias with right-hand use and a leftward bias with left-hand use; however, research with AD/HD participants has failed to similarly measure the effects of hand use, which was the focus of this study. Method: Line bisection was used to measure differences in right hemisphere functioning in children (7 to 12 years) with AD/HD-I and AD/HD-C. Results: Initial AD/HD group findings (without subtype differentiation) replicated previous research. However, further subtype analyses showed that the ADHD-I and ADHD-C groups perform significantly differently. Specifically, the ADHD-I group showed a leftward bias, irrespective of hand use, and the ADHD-C group showed a rightward bias, irrespective of hand use. Conclusion: These findings suggest that the subtypes represent two distinct disorders and that, unlike ADHD-C, ADHD-I may not be the result of right hemisphere dysfunction.
ADHD and Infant Disorganized Attachment
Authors: Pinto Carmen , Turton Penelope , Hughes Patricia , White Sarah , Gillberg Christopher
Published: July 2006

Objective: To examine whether infant disorganized attachment predicts ADHD at school age. Method: A cohort of 53 children who had been identified as having significant levels of disorganized attachment in infancy is compared to a control group. Symptoms and signs of ADHD at age 7 are evaluated together with a range of relevant maternal variables. Results: An association is found between infant disorganized attachment scores and teacher-rated symptoms of ADHD (but not ADHD caseness). Probable ADHD caseness in the child is associated with self-rated retrospective ADHD scores in mothers. Possible ADHD caseness is associated with a measure of unresolved mourning in mothers. Mother-rated ADHD in the child was associated with low overall maternal psychosocial functioning. Conclusion: The finding of a link between scores for disorganized attachment at 1 year and later teacher-rated symptoms of ADHD suggests the need for further studies.
ADHD in College Students
Authors: Weyandt Lisa L. , DuPaul George
Published: July 2006

Objective: According to the American Psychiatric Association, 3% to 7% of the school-age population has ADHD and many children continue to display significant symptoms throughout adolescences and adulthood. Relative to the childhood literature, less is known about ADHD in adults, especially college students with ADHD. The principle purpose of this review articles is to summarize the major research findings concerning ADHD in the college student population with regard to prevalence of symptoms, neuropsychological and psychological functioning. Overall, findings suggest that college students with ADHD are at greater risk for academic and psychological difficulties, and they perform similar to non-ADHD controls on many neuropsychological tasks. These findings are preliminary, however, and are tempered by the small number of studies that have been conducted as well as the methodological limitations of these studies. Conclusion: Future research using larger sample sizes, rigorous assessment criteria, and a longitudinal design is needed to better understand the psychological, academic, and neuropsychological functioning of college students with ADHD. Studies are also needed to elucidate the effects of pharmacological and nonpharmacological effects of treatment on the functioning of college students with this disorder.
Training Attention-Switching Ability in Adults With ADHD
Authors: White Holly A. , Shah Priti
Published: July 2006

Objective: Children with ADHD show attention-switching impairment. The present study assessed attention-switching ability in adults with ADHD, the extent to which this ability can be improved via targeted training, and the degree to which training extends to novel tasks of attention-switching. Method: Adults with ADHD (n = 16) and adults without ADHD (n = 18) were divided into training and non-training groups. Training groups performed six blocks of four different attention-switching tasks, while non-training groups completed non-switching, “filler” tasks. Lastly, the four groups were tested on two novel attention-switching tasks. Results: Adults with ADHD showed impaired attention-switching, relative to non-ADHD adults, but training significantly improved attention-switching in both ADHD and non-ADHD training groups. Finally, training effects transferred to new tasks of attention-switching. Conclusion: Adults with ADHD show attention-switching impairments, but deficits may be ameliorated with short-term, targeted training. Research has implications for cognitive training in ADHD.
Literacy development of linguistically diverse first graders in a mainstream English classroom: Connecting speaking and writing
Authors: Kennedy Eileen
Published: July 2006

Children who speak different home languages and dialects in a monolingual classroom often carry the challenge of having to develop literacy in a different language. This article presents a qualitative study of five first graders who speak different home languages in an inner city mainstream English classroom. Through interviews, classroom writing, field notes, and recorded classroom interaction, I present findings that indicate that writing in mainstream English can be problematic cognitively and emotionally for these children. I also offer some ways to foster an intercultural space for these children in a monolingual classroom and help find a way of validating diverse students’ language and culture.
Soluble triggering receptor expressed on myeloid cells-1 in acute respiratory infections
Authors: Phua J. , Koay E. S. C. , Zhang D. , Tai L. K. , Boo X. L. , Lim K. C. , Lim T. K.
Published: July 2006

Levels of the soluble form of the triggering receptor expressed on myeloid cells (sTREM)-1 are elevated in severe sepsis. However, it is not known whether sTREM-1 measurements can distinguish milder bacterial infections from noninfectious inflammation. The present authors studied whether serum sTREM-1 levels differ in community-acquired pneumonia, exacerbations of chronic obstructive pulmonary disease (COPD), asthma and controls, and whether sTREM-1 may be used as a surrogate marker for the need for antibiotics.

Serum sTREM-1 levels in 150 patients with pneumonia, COPD and asthma exacerbations and 62 healthy controls were measured.

Serum sTREM-1 levels were significantly elevated in pneumonia (median 295.2 ng·mL-1), COPD (280.3 ng·mL-1) and asthma exacerbations (184.0 ng·mL-1) compared with controls (83.1 ng·mL-1). Levels were higher in pneumonia and Anthonisen type 1 COPD exacerbations than in type 2 and 3 COPD and asthma exacerbations. The area under the receiver operating characteristics curve for sTREM-1 as a surrogate marker for the need for antibiotics was 0.77.

Serum levels of the soluble form of the triggering receptor expressed on myeloid cells-1 were elevated predominantly in pneumonia and Anthonisen type 1 COPD exacerbationsversustype 2 and 3 chronic obstructive pulmonary disease exacerbations, asthma and controls. Serum levels of the soluble form of the triggering receptor expressed on myeloid cells-1 has moderate but insufficient accuracy as a surrogate marker for the need for antibiotics in lower respiratory tract infections.
Chest radiography and pneumonia in primary care: diagnostic yield and consequences for patient management
Authors: Speets A. M. , Hoes A. W. , van der Graaf Y. , Kalmijn S. , Sachs A. P. E. , Mali W. P. Th. M.
Published: July 2006

The current prospective cohort study assessed the diagnostic yield of chest radiography (CXR) in primary-care patients suspected of pneumonia.

In total, 192 patients with a clinical suspicion of pneumonia aged ≥18 yrs were referred by their general practitioner (GP) for CXR to one of the three participating hospitals in the Netherlands. All GPs were asked to complete a standardised form before and after CXR.

Pneumonia was diagnosed by GPs in 35 (18%) patients, of whom 27 (14%) patients had a positive CXR, and eight (4%) patients a negative CXR, but with an assumed high probability of pneumonia by the GP. CXR clearly influenced the diagnosis of pneumonia by the GP in 53% of the patients. CXR ruled out pneumonia in 47% and the probability of pneumonia substantially increased in 6% of the patients. Patient management changed after CXR in 69% of the patients, mainly caused by a reduction in medication prescription (from 43 to 17%) and more frequent reassurance of the patient (from 8 to 35%).

In conclusion, pneumonia was frequently over diagnosed clinically by general practitioners. Chest radiography is a valuable diagnostic tool to substantially reduce the number of patients misdiagnosed and is particularly important for the exclusion of pneumonia in general practice.
Outcome of pulmonary multidrug-resistant tuberculosis: a 6-yr follow-up study
Authors: Chiang C-Y. , Enarson D. A. , Yu M-C. , Bai K-J. , Huang R-M. , Hsu C-J. , Suo J. , Lin T-P.
Published: July 2006

A retrospective study was performed to determine factors associated with the outcome of pulmonary multidrug-resistant tuberculosis (MDR-TB) in Taipei, Taiwan.

All patients newly diagnosed with pulmonary MDR-TB in a referral centre from 1992–1996 were enrolled and their outcome over the subsequent 6 yrs was determined.

A total of 299 patients were identified, comprising 215 (71.9%) males and 84 (28.1%) females with a mean age of 47.3 yrs. The patients received a mean of 3.7 effective drugs. Out of the 299 patients, 153 (51.2%) were cured, 31 (10.4%) failed, 28 (9.4%) died and 87 (29.1%) defaulted. Of the 125 patients receiving second-line drugs with ofloxacin, 74 (59.2%) were cured. Those who received ofloxacin had a lower risk of relapse than those receiving only first-line drugs (hazard ratio (HR) 0.16, 95% confidence interval (CI) 0.03–0.81) and a lower risk of TB-related death than those receiving second-line drugs but not ofloxacin (adjusted HR 0.50, 95% CI 0.31–0.82).

In conclusion, multidrug-resistant tuberculosis patients who received ofloxacin were more likely to be cured, and were less likely to die, fail or relapse. The utility of new-generation fluoroquinolones, such as moxifloxacin, in the treatment of multidrug-resistant tuberculosis needs to be evaluated. Default from treatment is a major challenge in the treatment of multidrug-resistant tuberculosis.
Comparative EST analysis provides insights into the basal aquatic fungus Blastocladiella emersonii
Authors: Ribichich Karina F , Georg Raphaela C , Gomes Suely L
Published: July 2006

Background

Blastocladiella emersonii is an aquatic fungus of the Chytridiomycete class, which is at the base of the fungal phylogenetic tree. In this sense, some ancestral characteristics of fungi and animals or fungi and plants could have been retained in this aquatic fungus and lost in members of late-diverging fungal species. To identify in B. emersonii sequences associated with these ancestral characteristics two approaches were followed: (1) a large-scale comparative analysis between putative unigene sequences (uniseqs) from B. emersonii and three databases constructed ad hoc with fungal proteins, animal proteins and plant unigenes deposited in Genbank, and (2) a pairwise comparison between B. emersonii full-length cDNA sequences and their putative orthologues in the ascomycete Neurospora crassa and the basidiomycete Ustilago maydis.

Results

Comparative analyses of B. emersonii uniseqs with fungi, animal and plant databases through the two approaches mentioned above produced 166 B. emersonii sequences, which were identified as putatively absent from other fungi or not previously described. Through these approaches we found: (1) possible orthologues of genes previously identified as specific to animals and/or plants, and (2) genes conserved in fungi, but with a large difference in divergence rate in B. emersonii. Among these sequences, we observed cDNAs encoding enzymes from coenzyme B12-dependent propionyl-CoA pathway, a metabolic route not previously described in fungi, and validated their expression in Northern blots.

Conclusion

Using two different approaches involving comparative sequence analyses, we could identify sequences from the early-diverging fungus B. emersonii previously considered specific to animals or plants, and highly divergent sequences from the same fungus relative to other fungi.
Serum repressing efflux pump CDR1 in Candida albicans
Authors: Yang Yun-Liang , Lin Yi-Hsuan , Tsao Ming-Yang , Chen Chia-Geun , Shih Hsin-I , Fan Jen-Chung , Wang Jang-Shiun , Lo Hsiu-Jung
Published: July 2006

Background

In the past decades, the prevalence of candidemia has increased significantly and drug resistance has also become a pressing problem. Overexpression of CDR1, an efflux pump, has been proposed as a major mechanism contributing to the drug resistance in Candida albicans. It has been demonstrated that biological fluids such as human serum can have profound effects on antifungal pharmacodynamics. The aim of this study is to understand the effects of serum in drug susceptibility via monitoring the activity of CDR1 promoter of C. albicans.

Results

The wild-type C. albicans cells (SC5314) but not the cdr1/cdr1 mutant cells became more susceptible to the antifungal drug when the medium contained serum. To understand the regulation of CDR1 in the presence of serum, we have constructed CDR1 promoter-Renilla luciferase (CDR1p-RLUC) reporter to monitor the activity of the CDR1 promoter in C. albicans. As expected, the expression of CDR1p-RLUC was induced by miconazole. Surprisingly, it was repressed by serum. Consistently, the level of CDR1 mRNA was also reduced in the presence of serum but not N-acetyl-D-glucosamine, a known inducer for germ tube formation.

Conclusion

Our finding that the expression of CDR1 is repressed by serum raises the question as to how does CDR1 contribute to the drug resistance in C. albicans causing candidemia. This also suggests that it is important to re-assess the prediction of in vivo therapeutic outcome of candidemia based on the results of standard in vitro antifungal susceptibility testing, conducted in the absence of serum.
Comparison of transcripts in Phalaenopsis bellina and Phalaenopsis equestris(Orchidaceae) flowers to deduce monoterpene biosynthesis pathway
Authors: Hsiao Yu-Yun , Tsai Wen-Chieh , Kuoh Chang-Sheng , Huang Tian-Hsiang , Wang Hei-Chia , Wu Tian-Shung , Leu Yann-Lii , Chen Wen-Huei , Chen Hong-Hwa
Published: July 2006

Background

Floral scent is one of the important strategies for ensuring fertilization and for determining seed or fruit set. Research on plant scents has hampered mainly by the invisibility of this character, its dynamic nature, and complex mixtures of components that are present in very small quantities. Most progress in scent research, as in other areas of plant biology, has come from the use of molecular and biochemical techniques. Although volatile components have been identified in several orchid species, the biosynthetic pathways of orchid flower fragrance are far from understood. We investigated how flower fragrance was generated in certainPhalaenopsisorchids by determining the chemical components of the floral scent, identifying floral expressed-sequence-tags (ESTs), and deducing the pathways of floral scent biosynthesis inPhalaneopsis bellinaby bioinformatics analysis.

Results

The main chemical components in theP. bellinaflower were shown by gas chromatography-mass spectrometry to be monoterpenoids, benzenoids and phenylpropanoids. The set of floral scent producing enzymes in the biosynthetic pathway from glyceraldehyde-3-phosphate (G3P) to geraniol and linalool were recognized through data mining of theP. bellinafloral EST database (dbEST). Transcripts preferentially expressed inP. bellinawere distinguished by comparing the scent floral dbEST to that of a scentless species,P. equestris, and included those encoding lipoxygenase, epimerase, diacylglycerol kinase and geranyl diphosphate synthase. In addition, EST filtering results showed that transcripts encoding signal transduction and Myb transcription factors and methyltransferase, in addition to those for scent biosynthesis, were detected byin silicohybridization of theP. bellinaunigene database against those of the scentless species, rice andArabidopsis. Altogether, we pinpointed 66% of the biosynthetic steps from G3P to geraniol, linalool and their derivatives.

Conclusion

This systems biology program combined chemical analysis, genomics and bioinformatics to elucidate the scent biosynthesis pathway and identify the relevant genes. It integrates the forward and reverse genetic approaches to knowledge discovery by which researchers can study non-model plants.
Improving preventive service delivery at adult complete health check-ups: the Preventive health Evidence-based Recommendation Form (PERFORM) cluster randomized controlled trial
Authors: Dubey Vinita , Mathew Roy , Iglar Karl , Moineddin Rahim , Glazier Richard
Published: July 2006

Background

To determine the effectiveness of a single checklist reminder form to improve the delivery of preventive health services at adult health check-ups in a family practice setting.

Methods

A prospective cluster randomized controlled trial was conducted at four urban family practice clinics among 38 primary care physicians affiliated with the University of Toronto. Preventive Care Checklist Forms© were created to be used by family physicians at adult health check-ups over a five-month period. The sex-specific forms incorporate evidence-based recommendations on preventive health services and documentation space for routine procedures such as physical examination. The forms were used in two intervention clinics and two control clinics. Rates and relative risks (RR) of the performance of 13 preventive health maneuvers at baseline and post-intervention and the percentage of up-to-date preventive health services delivered per patient were compared between the two groups.

Results

Randomly-selected charts were reviewed at baseline (n = 509) and post-intervention (n = 608). Baseline rates for provision of preventive health services ranged from 3% (fecal occult blood testing) to 93% (blood pressure measurement), similar to other settings. The percentage of up-to-date preventive health services delivered per patient at the end of the intervention was 48.9% in the control group and 71.7% in the intervention group. This is an overall 22.8% absolute increase (p = 0.0001), and 46.6% relative increase in the delivery of preventive health services per patient in the intervention group compared to controls. Eight of thirteen preventive health services showed a statistically significant change (p < 0.05) in favor of the intervention (adjusted RR (95% C.I.)): counseling on brushing/flossing teeth (9.2 (4.3–19.6)), folic acid counseling (7.5 (2.7–20.8)), fecal occult blood testing (6.7 (1.9–24.1)), smoking cessation counseling (3.9 (2.2–7.2)), tetanus immunization (3.0 (1.7–5.2)), history of alcohol intake (1.33 (1.2–1.5)), history of smoking habits (1.28 (1.2–1.4)) and blood pressure measurement (1.05 (1.00–1.10)).

Conclusion

This simple, low cost, clinically relevant intervention improves the delivery of preventive health services by prompting physicians of evidence-based recommendations in a checklist format that incorporates existing practice patterns. Periodic updates of the Preventive Care Checklist Forms© will allow a feasible and easy-to-use tool for primary care physicians to provide evidence-based preventive health services to adults at routine health check-ups. The forms can also be incorporated into an electronic health record. The Preventive Care Checklist Forms© are accessible in English and French at the College of Family Physicians of Canada web site.
Glucose testing and insufficient follow-up of abnormal results: a cohort study
Authors: Kern Lisa M , Callahan Mark A , Brillon David J , Vargas Maryelena , Mushlin Alvin I
Published: July 2006

Background

More than 6 million Americans have undiagnosed diabetes. Several national organizations endorse screening for diabetes by physicians, but actual practice is poorly understood. Our objectives were to measure the rate, the predictors and the results of glucose testing in primary care, including rates of follow-up for abnormal values.

Methods

We conducted a retrospective cohort study of 301 randomly selected patients with no known diabetes who received care at a large academic general internal medicine practice in New York City. Using medical records, we collected patients' baseline characteristics in 1999 and followed patients through the end of 2002 for all glucose tests ordered. We used multivariate logistic regression to measure associations between diabetes risk factors and the odds of glucose testing.

Results

Three-fourths of patients (78%) had at least 1 glucose test ordered. Patient age (≥45 vs. <45 years), non-white ethnicity, family history of diabetes and having more primary care visits were each independently associated with having at least 1 glucose test ordered (p < 0.05), whereas hypertension and hyperlipidemia were not. Fewer than half of abnormal glucose values were followed up by the patients' physicians.

Conclusion

Although screening for diabetes appears to be common and informed by diabetes risk factors, abnormal values are frequently not followed up. Interventions are needed to trigger identification and further evaluation of abnormal glucose tests.
Anti-erbB2 treatment induces cardiotoxicity by interfering with cell survival pathways
Authors: Pugatsch Thea , Abedat Suzan , Lotan Chaim , Beeri Ronen
Published: July 2006

Introduction

Cardiac dysfunction is among the serious side effects of therapy with recombinant humanized anti-erbB2 monoclonal antibody. The antibody blocks ErbB-2, a receptor tyrosine kinase and co-receptor for other members of the ErbB and epidermal growth factor families, which is over-expressed on the surface of many malignant cells. ErbB-2 and its ligands neuregulin and ErbB-3/ErbB-4 are involved in survival and growth of cardiomyocytes in both postnatal and adult hearts, and therefore the drug may interrupt the correct functioning of the ErbB-2 pathway.

Methods

The effect of the rat-anti-erbB2 monoclonal antibody B-10 was studied in spontaneously beating primary myocyte cultures from rat neonatal hearts. Gene expression was determined by RT-PCR (reverse transcription polymerase chain reaction) and by rat stress-specific microarray analysis, protein levels by Western blot, cell contractility by video motion analysis, calcium transients by the FURA fluorescent method, and apoptosis using the TUNEL (terminal uridine nick-end labelling) assay.

Results

B-10 treatment induces significant changes in expression of 24 out of 207 stress genes analyzed using the microarray technique. Protein levels of ErbB-2, ErbB-3, ErbB-4 and neuregulin decreased after 1 day. However, both transcription and protein levels of ErbB-4 and gp130 increased several fold. Calreticulin and calsequestrin were overexpressed after three days, inducing a decrease in calcium transients, thereby influencing cell contractility. Apoptosis was induced in 20% cells after 24 hours.

Conclusion

Blocking ErbB-2 in cultured rat cardiomyocytes leads to changes that may influence the cell cycle and affects genes involved in heart functions. B-10 inhibits pro-survival pathways and reduces cellular contractility. Thus, it is conceivable that this process may impair the stress response of the heart.
Exposure of the Cervical Internal Carotid Artery: Surgical Steps to the Cranial Base and Morphometric Study
Authors: Beretta Federica , Hemida Salah A. , Andaluz Norberto , Zuccarello Mario , Keller Jeffrey T.
Published: July 2006

OBJECTIVE:

Several studies have reported on approaches to increase exposure of the distal cervical internal carotid artery (ICA), but these studies have neither systematically addressed the anatomic aspects nor quantified the additional exposure of each maneuver. We describe surgical steps to expose the ICA region, quantify the additional exposure of each operative step, and discuss ways to minimize surgical morbidity.

METHODS:

The ICA was exposed in 10 formalin-fixed cadaveric heads using the following four steps: 1) anterior sternocleidomastoid approach, 2) retroparotid dissection and division of the digastric muscle, 3) section of the styloid apparatus, and 4) mandibulotomy. After completion of each step, the most distal level of ICA exposure was marked with a hemoclip and segment lengths were measured between each clip.

RESULTS:

Sectioning of the digastric muscle and sectioning of the styloid apparatus provided the most significant exposure of the ICA (14.15 and 15.08 mm, respectively) with minimal risks. Mandibulotomy added 10.20 mm in length and 20.65 degrees in width, but is a maneuver that must be weighed against the heightened risk of morbidity.

CONCLUSION:

Surgical exposure of the distal cervical ICA is associated with relatively high morbidity that increases with higher levels of exposure. Staged maneuvers have been shown to increase ICA exposure, especially in our systematic approach. The number of steps required varies depending on the level of lesion. Complete understanding of the surgical anatomy is essential to minimize surgical morbidity and to develop surgical expertise.