bluuebunny/crossref_metadata_2025 huggingface dataset:
Evolution of the β‐propeller fold
Authors: Chaudhuri Indronil , Söding Johannes , Lupas Andrei N.
Published: November 2007

β‐Propellers are toroidal folds, in which repeated, four‐stranded β‐meanders are arranged in a circular and slightly tilted fashion, like the blades of a propeller. They are found in all domains of life, with a strong preponderance among eukaryotes. Propellers show considerable sequence diversity and are classified into six separate structural groups by the SCOP and CATH databases. Despite this diversity, they often show similarities across groups, not only in structure but also in sequence, raising the possibility of a common origin. In agreement with this hypothesis, most propellers group together in a cluster map of all‐β folds generated by sequence similarity, because of numerous pairwise matches, many of which are individually nonsignificant. In total, 45 of 60 propellers in the SCOP25 database, covering four SCOP folds, are clustered in this group and analysis with sensitive sequence comparison methods shows that they are similar at a level indicative of homology. Two mechanisms appear to contribute to the evolution of β‐propellers: amplification from single blades and subsequent functional differentiation. The observation of propellers with nearly identical blades in genomic sequences show that these mechanisms are still operating today. Proteins 2008. © 2007 Wiley‐Liss, Inc.
Strategies for the cost‐effective use of oral antidiabetic drugs
Authors: Burrill Peter , Krentz Andrew
Published: November 2007

The UK prevalence of diabetes continues to increase, alongside the development of new drug classes and management guidelines. As a result, prescriptions for and spending on antidiabetic drugs continue to grow. In this article the authors discuss how to maximise treatment results and minimise spending by optimising each step in the diabetes management pathway. Copyright © 2007 Wiley Interface Ltd
A framework for capturing and analyzing the failures due to system/component interactions
Authors: Nepal Bimal P. , Yadav Om P. , Monplaisir Leslie , Murat Alper
Published: November 2007

To keep up with the speed of globalization and growing customer demands for more technology‐oriented products, modern systems are becoming increasingly more complex. This complexity gives rise to unpredictable failure patterns. While there are a number of well‐established failure analysis (physics‐of‐failure) models for individual components, these models do not hold good for complex systems as their failure behaviors may be totally different. Failure analysis
of individual components does consider the environmental interactions but is unable to capture the system interaction effects on failure behavior. These models are based on the assumption of independent failure mechanisms. Dependency relationships and interactions of components in a complex system might give rise to some new types of failures that are not considered during the individual failure analysis of that component. This paper presents a general framework for failure modes and effects analysis (FMEA) to capture and analyze component interaction failures. The advantage of the proposed methodology is that it identifies and analyzes the system failure modes due to the interaction between the components. An example is presented to demonstrate the application of the proposed framework for a specific product architecture (PA) that captures interaction failures between different modules. However, the proposed framework is generic and can also be used in other types of PA. Copyright © 2007 John Wiley & Sons, Ltd.
Analysis of perfluoroalkyl anion fragmentation pathways for perfluoroalkyl carboxylates and sulfonates during liquid chromatography/tandem mass spectrometry: evidence for fluorine migration prior to secondary and tertiary fragmentation
Authors: Arsenault Gilles , McAlees Alan , McCrindle Robert , Riddell Nicole
Published: November 2007

It is known that under liquid chromatography/electrospray tandem mass spectrometry (LC/ES‐MS/MS) conditions, the perfluorocarboxylate anion [RFCO2]− first loses CO2 to give a perfluoroalkyl anion R, [(MH)CO2]−, which can subsequently fragment to give inter alia lower mass carbanions. It has been suggested in a previous study that such secondary fragmentation involves cleavage of CnF2n segments. Our study of the LC/ES‐MS/MS of a series of 13C‐labeled perfluoroalkyl carboxylic acids (PFCAs) indicates that fragmentation of the R anion does not involve simple 'unzipping' of a primary perfluoroalkyl anion of the type F3C(CF2)xCF. For example, we have discovered that the secondary transition for the mass‐labeled PFOA, perfluoro‐1,2,3,4‐13C4‐octanoic acid (MPFOA), gives two signals of equal intensity at m/z 169 and 172. We propose a mechanism of fragmentation that involves rapid fluorine shifts, after the initial decarboxylation, which generate a series of new anions prior to secondary and tertiary fragmentation. Copyright © 2007 John Wiley & Sons, Ltd.
Differential ionisation of natural antioxidant polyenes in electrospray and nanospray mass spectrometry
Authors: Guaratini Thais , Gates Paul J. , Pinto Ernani , Colepicolo Pio , Lopes Norberto P.
Published: November 2007

Carotenoids are natural products with high economic relevance for the pharmaceutical industries and are a common subject for biochemical research. Reported here is a comparative study of the ionisation of carotenoids by electrospray mass spectrometry (ESI‐MS) and nanospray mass spectrometry (nanoESI‐MS). The results demonstrate that, along with solvent choice, the influence of the different ionisation processes of ESI and nanoESI are fundamental in determining how ionisation is achieved and which ions (molecular ion or protonated molecule) are observed in MS. The increased understanding afforded by this study will help in the development of unequivocal microanalytical methods for carotenoids and related antioxidant polyenes. Copyright © 2007 John Wiley & Sons, Ltd.
Metal–ligand solution equilibria studied by electrospray ionization mass spectrometry: correlation between ion intensity and acid–base equilibria in solution
Authors: Di Marco Valerio B. , Bombi G. Giorgio , Ranaldo Martina , Traldi Pietro
Published: November 2007

Electrospray ionization mass spectrometry (ESI‐MS) is increasingly used in the study of metal–ligand equilibria in aqueous solutions. However, the correlation between conditions in solution and mass spectra in the gas phase is far from being completely established. In the present work the equation i = kC0f was used to correlate relative ion intensity (i) in an ESI mass spectrum, the stoichiometric concentration (C0) in solution of the complex which produced this ion, and the fraction (f) of complex having the same protonation state as that of the ion detected in the spectrum. This equation takes into account that metal–ligand complexes have acid–base properties, and that these properties affect the efficiency by which the ions are brought from the solution to the gas phase. The equation was experimentally checked by electrospraying solutions containing aluminium(III) and any of the four ligands 3,4‐dihydroxybenzoic acid, 3‐hydroxy‐2‐(1H)pyridinone, citric acid, and ethylenediaminetetramethylenephosphonic acid at different pH values. ESI‐MS experimental i values and C0f values calculated from literature data were plotted versus the solution pH. Values are correlated in the majority of cases, thus confirming the validity of the approach proposed. Correlation is lost, as expected, for low f or C0 values, and when extensive gas‐phase reactions occur. The equation i = kC0f can be used to estimate quantitative data for unknown metal–ligand solutions analyzed by ESI‐MS. Copyright © 2007 John Wiley & Sons, Ltd.
Quantification of rat brain neurotransmitters and metabolites using liquid chromatography/electrospray tandem mass spectrometry and comparison with liquid chromatography/electrochemical detection
Authors: Tareke Eden , Bowyer John F. , Doerge Daniel R.
Published: November 2007

Analytical methodology based on solid‐phase extraction, polar reversed‐phase liquid chromatography, and electrospray tandem mass spectrometry (LC/MS/MS) with isotope dilution was developed and validated for quantifying the neurotransmitters, dopamine and serotonin, and their major metabolites in brain tissue. Limits of detection (0.1–20 pg/mg tissue) were sufficient for analysis of multiple neurotransmitters in rat brain regions, including parietal cortex, hypothalamus, pituitary, substantia nigra, and striatum. Method performance was compared with contemporaneous measurements using a well‐established procedure based on ion‐pairing reversed‐phase liquid chromatography and amperometric detection. The principal advantages of the LC/MS/MS method include a more robust sample purification procedure, an optimized chromatographic separation, and the qualitative and quantitative assurance that comes from coeluting isotopically labeled internal standards; however, sensitivity did not consistently improve upon that provided by amperometric detection. This methodology may be particularly useful for applications in which simultaneous determinations are required for drugs and their affected neurotransmitters in specific brain regions. Published in 2007 by John Wiley & Sons, Ltd.
Development of a rapid and validated method for investigating the metabolism of scoparone in rat using ultra‐performance liquid chromatography/electrospray ionization quadruple time‐of‐flight mass spectrometry
Authors: Wang Xijun , Lv Haitao , Sun Hui , Liu Lian , Sun Wenjun , Cao Hongxin
Published: November 2007

Scoparone (6,7‐dimethoxycoumarin) is known to have a wide range of pharmacological properties. In this study, a rapid and validated ultra‐performance liquid chromatography/electrospray ionization quadruple time‐of‐flight mass spectrometry (UPLC/ESI‐QTof‐MS) method was developed to investigate the metabolism of scoparone in rat for the first time. The new method reduced the sample handling and analytical time by three‐ to six‐fold, and the detection limit by five‐ to 1000‐fold, compared to published methods. Far more metabolites were detected and identified compared to published data, which were preliminarily identified as scopoletin, isoscopoletin, isofraxidin, and fraxidin, respectively, when subjected to tandem mass spectrometry analyses. It is found that the metabolic trajectory of scoparone in rat focused on phase I metabolism which is obviously different from published results, and revealed a wide range of pharmacological properties of scoparone partly attributed to the bioactivities of its metabolites. Copyright © 2007 John Wiley & Sons, Ltd.
Adjusting for verification bias in diagnostic test evaluation: A Bayesian approach
Authors: Buzoianu Manuela , Kadane Joseph B.
Published: November 2007

Obtaining accurate estimates of the performance of a diagnostic test for some population of patients might be difficult when the sample of subjects used for this purpose is not representative for the whole population. Thus, in the motivating example of this paper a test is evaluated by comparing its results with those given by a gold standard procedure, which yields the disease status verification. However, this procedure is invasive and has a non‐negligible risk of serious complications. Moreover, subjects are selected to undergo the gold standard based on some risk factors and the results of the test under study. The test performance estimates based on the selected sample of subjects are biased. This problem was presented in previous studies under the name of verification bias. The current paper introduces a Bayesian method to adjust for this bias, which can be regarded as a missing data problem. In addition, it addresses the case of non‐ignorable verification bias. The proposed Bayesian estimation approach provides test performance estimates that are consistent with the results obtained using likelihood‐based approach. In addition, the paper studies how valuable the statistical findings are from the perspective of clinical decision making. Copyright © 2007 John Wiley & Sons, Ltd.
A false‐discovery‐rate‐based loss framework for selection of interactions
Authors: Chen Wei , Ghosh Debashis , Raghunathan Trivellore E. , Sargent Daniel J.
Published: November 2007

Interaction effects have been consistently found important in explaining the variation in outcomes in many scientific research fields. Yet, in practice, variable selection including interactions is complicated due to the limited sample size, conflicting philosophies regarding model interpretability, and accompanying amplified multiple‐testing problems. The lack of statistically sound algorithms for automatic variable selection with interactions has discouraged activities in exploring important interaction effects. In this article, we investigated issues of selecting interactions from three aspects: (1) What is the model space to be searched? (2) How is the hypothesis‐testing performed? (3) How to address the multiple‐testing issue? We propose loss functions and corresponding decision rules that control FDR in a Bayesian context. Properties of the decision rules are discussed and their performance in terms of power and FDR is compared through simulations. Methods are illustrated on data from a colorectal cancer study assessing the chemotherapy treatments and data from a diffuse large‐B‐cell lymphoma study assessing the prognostic effect of gene expressions. Copyright © 2007 John Wiley & Sons, Ltd.
Parkhaussysteme in Stahlverbundbauweise
Authors: Kurz Wolfgang
Published: November 2007

Bei offenen Parkhäusern hat sich die Stahl‐ und Stahlverbundbauweise aus technischen und wirtschaftlichen Gründen als Regelbauweise etabliert. Die Besonderheiten der gebräuchlichen Systeme von Stahlverbundparkhäusern werden vorgestellt und erläutert. Bewährte Maßnahmen zur Sicherung der Dauerhaftigkeit der Bauwerke und ihrer Tragglieder werden vorgestellt.
Synthesis and Preparation of Crosslinked Allylglycidyl Ether‐Modified Starch‐Wood Fibre Composites
Authors: Duanmu Jie , Gamstedt E. Kristofer , Rosling Ari
Published: November 2007

Native potato starch has been modified with allylglycidyl ether (AGE) under various reaction conditions including different sodium hydroxide and AGE concentrations, reaction temperatures and times. 1H‐NMR and FT‐IR were used to analyze the products. AGE‐modified starch, with two degrees of substitution (DS), namely DS = 1.3 and DS = 2.3, was synthesized and used for preparation of a new family of crosslinked composites reinforced with various amounts of bleached softwood fibres. Composite premixes of modified starch, wood fibres and ethylene glycol dimethacrylate (EGDA) were cured in a hot press using 2% (w/w) of benzoyl peroxide at 150°C under high pressure for 10 min. The matrix with high degree of substitution exhibited good processability and was easily processed even for the highest fibre contents, up to 70% (w/w). In addition, scanning electron micrographs showed good dispersion and adhesion between the starch matrix with high degree of substitution and fibre. The original poor mechanical properties of the cured modified starch were markedly improved by the addition of wood fibres. In the extractions tests cured high‐DS and low‐DS composite samples showed weight losses in the range of 1 and 15% (w/w), respectively. No unreacted crosslinker ethylene glycol dimethacrylate was detected in the solutes as determined by NMR.
Space systems verification program and management process
Authors: Nagano Satoshi
Published: November 2007

Having a solid verification program that ensures a “system is built right” plays a crucial role in both government and commercial space programs, since even the smallest error in a requirement, design/analysis, test, or inspection at every level of a system development could cause a major system malfunction and would be almost impossible to troubleshoot and repair once in space. According to the space/launch vehicles (SV/LVs) failure related data that have been collected by Aerospace Corporation since the 1960s, almost all of the post‐launch failures could have been prevented if their problems had been discovered prior to the shipment of these vehicles to their launch sites. In particular, it was found that the majority of these vehicles could have been successful if deficiencies were corrected during early phase (requirement and design phases) or lower system level of their systems development. In general, any latent problems discovered later on in system development would significantly impact cost and schedule of space programs, even if they were successfully corrected prior to launch. This paper presents a systematic approach to planning and executing verification of space systems based on a distributed‐space system verification program. It enforces a standardized set of modular‐management processes at every level and phase of space system development activities. This distributed verification program approach tries to enforce a standard set of management processes in order to prevent Total System Program Responsibility (TSPR) philosophy, a “faster, better, cheaper” approach, from being unintentionally adopted at any level of space system development due to schedule and cost pressures. This space systems verification approach is now explained in an U.S. DoD best practice document and also included in The Aerospace Corporation's specification and standard list. It has also been adopted as a compliance document in some major U.S. space programs, such as GPS Block III, and national security space programs. © 2007 Wiley Periodicals, Inc. Syst Eng
The damped outrigger concept for tall buildings
Authors: Smith Rob J. , Willford Michael R.
Published: November 2007

This paper describes new concepts for the structural design of high‐rise buildings, in which a system is introduced to increase the dependable structural damping by a factor of 5–10. By so doing the dynamic response of the building to wind effects (buffeting and vortex shedding) is virtually eliminated, leading to substantially reduced lateral design forces and assured occupant comfort. Substantial reductions in structural member size and construction cost savings can be realized in many cases. This may significantly improve the economic viability and sustainability of a development. The paper describes some means by which high levels of damping may be achieved and is illustrated by an implementation on a building, currently under construction, subjected to wind and seismic excitation. Copyright © 2007 John Wiley & Sons, Ltd.
Burj Dubai: engineering the world's tallest building
Authors: Baker William F. , Korista D. Stanton , Novak Lawrence C.
Published: November 2007

As with all super‐tall projects, difficult structural engineering problems needed to be addressed and resolved. This paper presents the approach to the structural system for the Burj Dubai Tower. Copyright © 2007 John Wiley & Sons, Ltd.
Contextualizing instruction: Leveraging students' prior knowledge and experiences to foster understanding of middle school science
Authors: Rivet Ann E. , Krajcik Joseph S.
Published: November 2007

Contextualizing science instruction involves utilizing students' prior knowledge and everyday experiences as a catalyst for understanding challenging science concepts. This study of two middle school science classrooms examined how students utilized the contextualizing aspects of project‐based instruction and its relationship to their science learning. Observations of focus students' participation during instruction were described in terms of a contextualizing score for their use of the project features to support their learning. Pre/posttests were administered and students' final artifacts were collected and evaluated. The results of these assessments were compared with students' contextualizing scores, demonstrating a strong positive correlation between them. These findings provide evidence to support claims of contextualizing instruction as a means to facilitate student learning, and point toward future consideration of this instructional method in broader research studies and the design of science learning environments. © 2007 Wiley Periodicals, Inc. J Res Sci Teach 45: 79–100, 2008
Interactive patterns and conceptual convergence during student collaborations in science
Authors: Oliveira Alandeom W. , Sadler Troy D.
Published: November 2007

This study examines cognitive and social processes in group interactions that shape collaborative learning in science classrooms. Three small groups of students were observed while working collaboratively on explaining the burning of a candle under a jar. The learning environment served as a context for examination of conceptual convergence, a process wherein students construct shared meanings for science concepts through gradual refinement of ambiguous, partial meanings presented in group space. Despite engaging in the same activity with very similar instructional supports, the groups displayed very different patterns of interaction and achieved varied degrees of conceptual convergence. One group collaborated effectively and displayed evidence of individual conceptualizations of science content converging to establish a more well‐informed shared conceptualization. The other groups were not as successful, each for unique reasons. Problems demonstrated in one group included lack of self‐confidence, poor monitoring of group learning, and active avoidance of potentially fruitful conceptual conflicts. The other group struggled primarily because of a combative social context. The major educational significance of this study was the identification of social context and interactive patterns, group approaches to conceptual conflicts, and instructors' roles in collaborative activities as crucial aspects of productive group learning. © 2007 Wiley Periodicals, Inc. J Res Sci Teach 45: 634–658, 2008
A longitudinal study of junior high school students' conceptions of the structure of materials
Authors: Margel Hannah , Eylon Bat‐Sheva , Scherz Zahava
Published: November 2007

This longitudinal study investigated the progression in junior high school (JHS) students' conceptions of the structure of matter while studying a new instructional approach dealing with “Materials.” In particular, we studied the progression of students' learning along two dimensions: (a) the conceptual model; and (b) the context of application. Students were asked to draw the structure of several materials and to write their explanations about the structure of these materials in questionnaires administered five times during a 3‐year period. Results indicate students' progression in their microscopic conceptualization of materials. Toward the end of the instruction about 85% of the students used a microscopic model in their representations, and 36% were able to give a molecular model. About 83% of the students retained a microscopic model. Different profiles of JHS students' progression in the conception of the structure of matter were identified. The study suggests that a long‐term development of the particulate model requires: (a) constructing a solid foundation of knowledge about microscopic structure of materials; and (b) a spiral instruction. © 2007 Wiley Periodicals, Inc. J Res Sci Teach 45: 132–152, 2008
Hypertrophic cardiomyopathy‐like changes in monochorionic twin pregnancies with selective intrauterine growth restriction and intermittent absent/reversed end‐diastolic flow in the umbilical artery
Authors: Muñoz‐Abellana B. , Hernandez‐Andrade E. , Figueroa‐Diesel H. , Ferrer Q. , Acosta‐Rojas R. , Cabero L. , Gratacos E.
Published: November 2007

Objective

To evaluate the prevalence of hypertrophic cardiomyopathy‐like (HCL) changes in monochorionic twins with selective intrauterine growth restriction (sIUGR) and intermittent absent/reversed end‐diastolic flow (iAREDF), also defined as Type III sIUGR, and the clinical relevance of this condition.

Methods

A total of 80 pregnancies with sIUGR were studied, 40 with, and 40 without iAREDF. HCL changes were defined as an increased thickness of either left or right ventricular wall (mean > 2 SD) estimated with M‐mode ultrasonography. Data were plotted on normal reference values constructed from 75 uncomplicated monochorionic twin pregnancies (150 fetuses) at 22–34 weeks' gestation. Perinatal outcomes in pregnancies with and without HCL changes were compared.

Results

In the group with iAREDF, 8/40 of the larger twins (20%) had HCL changes (five bilaterally, two in the right, and one in the left ventricle) as compared with 1/40 (2.5%) in fetuses without iAREDF (P = 0.03). No differences were observed in the smaller twin (1/40 in both groups). HCL changes were not associated with a significant increment in perinatal mortality as only one large fetus from the group with iAREDF died in utero. In the remaining 10 cases, no differences in the intertwin weight discordance, placental surface discordance, or rate of neonatal neurological damage were observed. However, all 10 presented mildly abnormal neonatal cardiac findings that resolved over time with no apparent short‐term impact on cardiac function.

Conclusions

HCL changes in the larger twin should be regarded as part of the spectrum of findings in Type III monochorionic‐sIUGR (presenting iAREDF). This finding does not seem to be associated with an increased rate of short‐term neurological or cardiac complications. Copyright © 2007 ISUOG. Published by John Wiley & Sons, Ltd.
Dynamic key management for secure routing in MANET
Authors: Peng Wuxu , Wang Yalin , Park E. K. , Makki Kia
Published: November 2007

A secure key management scheme for the locality caching multi‐root multi‐generation (LCMRMG) MANET routing algorithm is proposed. The scheme takes advantage of the multi‐root nature of LCMRMG and successfully integrates public key, certification and threshold technologies. The scheme is hierarchical and fully distributed. The key management operations are flexible in secure share distribution and scalable well to large MANET. Extensive simulations have shown that the scheme is secure, robust, efficient, and scalable. Copyright © 2007 John Wiley & Sons, Ltd.
A review of EDXRS in the study of human lead metabolism
Authors: Brito J. A. A. , Fleming D. E. B. , Chettle D. R.
Published: November 2007

Energy dispersive x‐ray spectrometry (EDXRS) techniques have been developed to measure in vivo the concentration of lead (Pb) in the bone of human subjects. One important effect that this use of EDXRS has had is to highlight the ways in which the previous best understanding of how Pb behaves in the human body is having to be adjusted. In particular, models of Pb metabolism that have been shown to account well for short‐term Pb exposures and blood Pb require modification of rates of transfer to and from bone in order to account for the long‐term aspects of the behavior of Pb in the body. Further, both the input function (the rate of build up of bone Pb concentration from blood Pb) and the output function (the rate of release of Pb from bone back into blood) show nonlinearity. That is, the rates are not constant; they vary with the extent of Pb exposure and age. Copyright © 2007 John Wiley & Sons, Ltd.
The localisation of biologically important metals in soft and calcified tissues using a synchrotron x‐ray fluorescence technique
Authors: Geraki K. , Farquharson M. J. , Bradley D. A. , Gundogdu O. , Falkenberg G.
Published: November 2007

A microbeam synchrotron x‐ray fluorescence (µ‐SXRF) technique has been employed in investigating the localisation of metals in two biological systems, soft and calcified tissue. Breast carcinoma is the focus of the former investigations, and osteoarthritis, that of the latter. Copper has been the metal of particular interest in breast tissue work, although 2D maps of other elements of importance have also been produced in present studies. Elemental maps were obtained at 18 µm spatial resolution and compared with light transmission images of histological sections. The comparison was successful when the sections were stained for cancer cells, revealing, in most cases, elevated metal levels in the cancer cells, with a possible exception of iron. With regard to a synovial joint in which an osteoarthritic lesion was found, the samples were taken from the equine joint allowing study of the distribution of calcium and zinc in cartilage and subchondral bone. Here, a particular question concerns the extent to which links can be established between the well‐delineated contours of elemental presence that are observed within this surface and the structural deformation characteristic of the osteoarthritic lesion. µ‐SXRF mappings, of depth resolution 15 µm, have been obtained from the joint surface, up‐to and just beyond the cement‐line that forms the bond between subchondral bone and cartilage. Outside of the immediate area of the lesion, the presence of Ca and Zn each display a peak at the cartilage surface and also at the tidemark; within the lesion there is significant loss of surface elemental enhancement. Copyright © 2007 John Wiley & Sons, Ltd.
Rhonda M. Williams: Competition, Race, Agency, and Community
Authors: Dymski Gary , Nembhard Jessica Gordon
Published: November 2007

As the United States approaches the twenty-first century … in an information-based, transnational and managerial economy, it is becoming increasingly apparent that if we do not better negotiate race and ethnicity in our society, we will not adequately solve the problems of economic inequality and discrimination. Racial and/or ethnic divisions and competition shape our efforts to understand and challenge hierarchy and inequity. As long as we ignore those issues, we cannot solve the problems of poverty, unemployment, and crime, nor effect productive job creation and economic justice. Absent a cultural and economic reckoning with racism's legacies, we will fail to revitalize our cities and to recover from the socioeconomic costs of “ending welfare as we knew it.” Although masked behind pronouncements of a “color-blind” society, unfinished racial business weakens our national will to provide one another the portfolio of social and economic rights essential to the sustenance of humane community in the post-industrial global economy. (Nembhard and Williams 1998)
CT Angiography in Pediatric Extremity Trauma: Preoperative Evaluation Prior to Reconstructive Surgery
Authors: Hsu Charles S. , Hellinger Jeffrey C. , Rubin Geoffrey D. , Chang James
Published: November 2007

Computed tomographic angiography (CTA) is a noninvasive modality for evaluating the vascular system and planning treatment strategies. The goal of this study was to validate the clinical utility of CTA in assessment of suspected pediatric extremity traumatic vascular injury, prior to emergent and delayed reconstructive surgery. A retrospective review was performed of all operative patients under 18 years of age who underwent multidetector-row CTA for evaluation of suspected extremity vascular injury. Parameters investigated included age, type of injury, referral source, temporal relationship between the injury and the CTA, CTA findings, operations performed, intraoperative findings, and clinical outcome. Between January 2002 and September 2005, 10 pediatric patients (6 males/4 females; mean age 8 years old, range 3–17) sustained either blunt ( N=8) or penetrating ( N=2) trauma and underwent CTA of the upper ( N=5) or lower extremities ( N=5). A total of 30% (3/10) of patients were referred from the emergency department acutely, 50% (5/10) were referred from the inpatient wards subacutely, and 20% (2/10) were referred from the outpatient clinics electively. Half ( N=5) underwent CTA to evaluate need for vascular repair, whereas half ( N=5) underwent CTA to evaluate local vasculature for flap reconstruction. Overall, 40% (4/10) of CTA findings were normal, whereas 60% (6/10) revealed traumatic vascular injuries. Pertinent nonvascular findings included soft tissue defects (60%, 6/10), fractures (40%, 4/10), and contracture deformities (20%, 2/10). In all cases, procedures were completed without complications, and intraoperative findings confirmed those from CTA. At a mean follow-up of 28 months, all injuries have healed without complications. CTA is a reliable noninvasive modality to evaluate pediatric patients with suspected traumatic extremity vascular injury and to plan treatment strategies for both vascular repair and extremity reconstruction.
Fine Splitting of Electron States in Silicon Nanocrystal with a Hydrogen-like Shallow Donor
Authors: Belyakov Vladimir A , Burdov Vladimir A
Published: November 2007

Electron structure of a silicon quantum dot doped with a shallow hydrogen-like donor has been calculated for the electron states above the optical gap. Within the framework of the envelope-function approach we have calculated the fine splitting of the ground sixfold degenerate electron state as a function of the donor position inside the quantum dot. Also, dependence of the wave functions and energies on the dot size was obtained.
New anchoring method for tarsal tendon transfers in myelomeningocele patients
Authors: Tomonori Kenmoku , Makoto Kamegaya , Takashi Saisu
Published: November 2007

We describe a new anchoring method for tarsal tendon transfers in myelomeningocele patients to protect the sole of the foot from pressure sores and skin necrosis and to loosen the tension of the transferred tendon.

Tendon transfer procedures were performed in 51 feet (33 patients) with myelomeningocele. We transferred tibialis anterior tendons to the second or third cuneiform in 19 with equinovarus deformities, and transferred tibialis anterior tendons to the calcaneus through the interosseous membrane in 32 with talipes calcaneus. Clinical results were evaluated with the muscle power of transferred tendons using manual muscle testing 6 months after surgery. The muscle test result was classified as good, fair, and poor.

After passing the tendon through the bony hole, a 2.0-mm Kirschner wire was inserted from the sole to the tibia through the ankle joint at neutral. (It extended from the sole through the posterior cortex of the tibia.) The remaining part of the wire was bent and formed into a loop shaped like the Greek letter “zeta” (ζ). The thread was then tied to the loop of the wire as tightly as possible. In this way, there was no contact with the sole during anchoring, thus avoiding ulcers. In addition, the transferred tendon could be kept stable because the patient's ankle was fixed by the Kirschner wire.

No cases of wound infection or skin necrosis of the sole occurred. In 49 of the 51 cases, transferred tendons were firmly anchored to tarsal bones. Muscle strength was good for 83%, fair for 13%, and poor for 4%. Consequently, 45 feet could obtain plantigrade pattern during their walking with shoe inserts or occasional use of ankle-foot orthoses.

Our anchoring method has the advantage of protecting the sole of the foot from pressure sores and skin necrosis, as well as maintaining tension on the transferred tendon until it settles down in an anchor hole.
Alternatively spliced forms of the P180 ribosome receptor differ in their ability to induce the proliferation of rough endoplasmic reticulum
Authors: Bai Ji‐Zhong , Leung Euphemia , Holloway Hilary , Krissansen Geoffrey W.
Published: November 2007

Expression of the canine 180‐kDa ribosome receptor p180 in yeast induces the synthesis of RER, and increases the mRNAs of secretory pathway proteins, and protein secretion. To assess whether p180 is a master regulator of cell secretion in mammalian cells, we stably expressed red fluorescent forms of the human p180 variants p180ΔR (no tandem repeats), p180R (26 repeats), and full‐length p180FR (54 repeats) containing different lengths of the tandem repeat ribosome‐binding domain in rat pancreatic RINm5F islet β‐cells. All three fluorescent p180 variants localized exclusively to the RER. Cells transfected with p180R were filled with ribosome‐studded karmellae, whereas p180ΔR and p180FR transfectants contained only increased amounts of mostly smooth ER. Unlike in yeast, over‐expression of p180R failed to increase the secretory pathway proteins calnexin, SEC61β, and calreticulin, or ribosome biogenesis. The data suggest that alternative splicing of the p180 tandem repeat domain is a means of regulating the ribosome‐binding activity of p180, and potentially the secretory activity of the cell. However, p180 is not a master regulator of mammalian cell secretion as it does not concomitantly trigger the synthesis of protein machinery required to enhance protein synthesis and cell secretion.
Long‐range organization of bacteriochlorophyll in chlorosomes of Chlorobium tepidum investigated by cryo‐electron microscopy
Authors: Oostergetel Gert T. , Reus Michael , Gomez Maqueo Chew Aline , Bryant Donald A. , Boekema Egbert J. , Holzwarth Alfred R.
Published: November 2007

Intact chlorosomes of Chlorobium tepidum were embedded in amorphous ice layers and examined by cryo‐electron microscopy to study the long‐range organization of bacteriochlorophyll (BChl) layers. End‐on views reveal that chlorosomes are composed of several multi‐layer tubules of variable diameter (20–30 nm) with some locally undulating non‐tubular lamellae in between. The multi‐layered tubular structures are more regular and larger in a C. tepidum mutant that only synthesizes [8‐ethyl, 12‐methyl]‐BChl d. Our data show that wild‐type C. tepidum chlorosomes do not have a highly regular, long‐range BChl c layer organization and that they contain several multi‐layered tubules rather than single‐layer tubules or exclusively undulating lamellae as previously proposed.
Controllable self‐assembly from fibrinogen–gold (fibrinogen–Au) and thrombin–silver (thrombin–Ag) nanoparticle interaction
Authors: Roy Shibsekhar , Dasgupta Anjan Kumar
Published: November 2007

Fibrinogen conjugated gold nanoparticles (fibrinogen–Au) and thrombin conjugated silver nanoparticles (thrombin–Ag) were synthesized by heating (90 °C) the proteins (50 μg protein/ml) with 1 mM AgNO3 or AuCl3. The resultant particles were harvested and examined by flow cytometry, scanning electron microscopy (SEM), transmission emission microscopy (TEM), optical microscopy and dynamic light scattering. SEM and TEM images revealed that the fibrinogen–Au and thrombin–Ag particles interacted. The emergent bio‐nanoconjugate population could be controlled by addition of thrombin–Ag. The method may be exploited in parametrizing coagulation factors and other clinically important protein–protein interactions.
Histological mapping of biochemical changes in solid tumors by FT‐IR spectral imaging
Authors: Petibois Cyril , Drogat Benjamin , Bikfalvi Andreas , Déléris Gérard , Moenner Michel
Published: November 2007

Fourier‐transform infrared (FT‐IR) spectral imaging was used for analyzing biochemical changes in tumor cells. Metabolic parameters of human lung A549/8 adenocarcinoma and U87 glioma cells were compared under stress conditions in culture along with tumor progression after cell implantation onto the chick embryo chorio‐allantoic membrane. In cell culture, glucose consumption and lactic acid release were higher in U87 cells. A549/8 cells were less sensitive to oxidative stress as observed through changes in fatty acyl chains. In vivo biochemical mapping of highly (U87) vs. poorly (A549/8) angiogenic tumors provided results comparable to culture models. Therefore, FT‐IR imaging allows detecting subtle chemical changes in tumors, which might be useful for diagnosis.
The diacylglycerol forming pathways differ among floral organs of Petunia hybrida
Authors: Nakamura Yuki , Ohta Hiroyuki
Published: November 2007

The origin of diacylglycerol, a substrate for membrane lipid biosynthesis, is not fully understood. Here, we report that Petunia hybrida floral organs contain large amounts of diacylglycerol. Our data suggest that in stamens and pistils diacylglycerol is supplied both from phosphatidylcholine by non‐specific phospholipase C activity and de novo via the Kennedy pathway and phosphatidic acid phosphatase, whereas in petals the two‐step pathway catalyzed by phospholipase D and phosphatidic acid phosphatase predominates. Therefore, the pathways that supply diacylglycerol differ among floral reproductive organs, although large amounts of diacylglycerol are commonly accumulated in these organs.
Social fears and social phobia in the USA: results from the National Comorbidity Survey Replication
Authors: Ruscio A. M. , Brown T. A. , Chiu W. T. , Sareen J. , Stein M. B. , Kessler R. C.
Published: November 2007

Background

Despite heightened awareness of the clinical significance of social phobia, information is still lacking about putative subtypes, functional impairment, and treatment-seeking. New epidemiologic data on these topics are presented from the National Comorbidity Survey Replication (NCS-R).

Method

The NCS-R is a nationally representative household survey fielded in 2001–2003. The World Health Organization (WHO) Composite International Diagnostic Interview Version 3.0 (CIDI 3.0) was used to assess 14 performance and interactional fears and DSM-IV social phobia.

Results

The estimated lifetime and 12-month prevalence of social phobia are 12.1% and 7.1% respectively. Performance and interactional fears load onto a single latent factor, and there is little evidence for distinct subtypes based either on the content or the number of fears. Social phobia is associated with significant psychiatric co-morbidity, role impairment, and treatment-seeking, all of which have a dose–response relationship with number of social fears. However, social phobia is the focus of clinical attention in only about half of cases where treatment is obtained. Among non-co-morbid cases, those with the most fears were least likely to receive social phobia treatment.

Conclusions

Social phobia is a common, under-treated disorder that leads to significant functional impairment. Increasing numbers of social fears are associated with increasingly severe manifestations of the disorder.
Health services use in eating disorders
Authors: Striegel-Moore R. H. , DeBar L. , Wilson G. T. , Dickerson J. , Rosselli F. , Perrin N. , Lynch F. , Kraemer H. C.
Published: November 2007

Background

This study examined healthcare services used by adults diagnosed with an eating disorder (ED) in a large health maintenance organization in the Pacific Northwest.

Method

Electronic medical records were used to collect information on all out-patient and in-patient visits and medication dispenses, from 2002 to 2004, for adults aged 18–55 years who received an ED diagnosis during 2003. Healthcare services received the year prior to, and following, the receipt of an ED diagnosis were examined. Cases were matched to five comparison health plan members who had a health plan visit close to the date of the matched case's ED diagnosis.

Results

Incidence of EDs (0.32% of the 104 130 females, and 0.02% of the 93 628 males) was consistent with prior research employing treatment-based databases, though less than community-based samples. Most cases (50%) were first identified during a primary-care visit and psychiatric co-morbidity was high. Health services use was significantly elevated in all service sectors among those with an ED when compared with matched controls both in the year preceding and that following the receipt of the incident ED diagnosis. Contrary to expectations, healthcare utilization was found to be similarly high across the spectrum of EDs (anorexia nervosa, bulimia nervosa, and eating disorders not otherwise specified).

Conclusions

The elevation in health service use among women both before and after diagnosis suggests that EDs merit identification and treatment efforts commensurate with other mental health disorders (e.g. depression) which have similar healthcare impact.
The relationship between prior psychiatric disorder and chronic fatigue: evidence from a national birth cohort study
Authors: Harvey S. B. , Wadsworth M. , Wessely S. , Hotopf M.
Published: November 2007

Background

Increased rates of psychiatric disorder have previously been reported in those diagnosed with chronic fatigue syndrome (CFS) or myalgic encephalomyelitis (ME), although the direction of causation in this relationship has not been established. We aimed to test the hypothesis that individuals with self-reported CFS/ME have increased levels of psychiatric disorder prior to the onset of their fatigue symptoms.

Method

A total of 5362 participants were prospectively followed with various measures of personality, psychiatric disorder and fatigue levels collected over the first 43 years of their life. CFS/ME was identified through self-report during a semi-structured interview at age 53 years.

Results

Thirty-four (1.1%) of the 3035 subjects assessed at age 53 years reported a diagnosis of CFS/ME. CFS/ME was more common among females, but there was no association between CFS/ME and either social class, social mobility or educational level. Those with psychiatric illness between the ages of 15 and 36 years were more likely to report CFS/ME later in life with an odds ratio (OR, adjusted for sex) of 2.65 [95% confidence interval (CI) 1.26–5.57,p=0.01]. Increased levels of psychiatric illness, in particular depression and anxiety, were present prior to the occurrence of fatigue symptoms. There was a dose–response relationship between the severity of psychiatric symptoms and the likelihood of later CFS/ME. Personality factors were not associated with a self-reported diagnosis of CFS/ME.

Conclusions

This temporal, dose–response relationship suggests that psychiatric disorders, or shared risk factors for psychiatric disorders, are likely to have an aetiological role in some cases of CFS/ME.
Omnidirectional vision and conformal geometric algebra for visual landmark identification
Authors: López-Franco C. , Bayro-Corrochano E.
Published: November 2007

The automatic landmark identification is very important in autonomous robot navigation tasks. In this paper, we use a monocular omnidirectional vision system to extract the image features and the conformal geometric algebra to compute the projective invariants from such features. We show how these features can be used to compute projective and permutationp2-invariantsfrom any kind of omnidirectional vision system. Thep2-invariantsrepresent scene sublandmarks, and a set of them characterize a landmark. The advantage of this representation is that the landmarks are more robust than the single cross-ratio.
Application of motor algebra to the analysis of human arm movements
Authors: Berman Sigal , Liebermann Dario G. , Flash Tamar
Published: November 2007

Motor algebra, a 4D degenerate geometric algebra, offers a rigorous yet simple representation of the 3D velocity of a rigid body. Using this representation, we study 3D extended arm pointing and reaching movements. We analyze the choice of arm orientation about the vector connecting the shoulder and the wrist, in cases for which this orientation is not prescribed by the task. Our findings show that the changes in this orientation throughout the movement were very small, possibly indicating an underlying motion planning strategy. We additionally examine the decomposition of movements into submovements and reconstruct the motion by assuming superposition of the velocity profiles of the underlying submovements by analyzing both the translational and rotational components of the 3D spatial velocity. This movement decomposition method reveals a larger number of submovement than is found using previously applied submovement extraction methods that are based only on the analysis of the hand tangential velocity. The reconstructed velocity profiles and final orientations are relatively close to the actual values, indicating that single-axis submovements may be the basic building blocks underlying 3D movement construction.