bluuebunny/crossref_metadata_2025 huggingface dataset:
Proteins in ecotoxicology – How, why and why not?
Authors: Lemos Marco F. L. , Soares Amadeu M. V. M. , Correia António C. , Esteves Ana C.
Published: December 2009

The growing interest in the application of proteomic technologies to solve toxicology issues and its relevance in ecotoxicology research has resulted in the emergence of “ecotoxicoproteomics”. There is a general consensus that ecotoxicoproteomics is a powerful tool to spot early molecular events involved in toxicant responses, which are responsible for the adverse effects observed at higher levels of biological organization, thus contributing to elucidate the mode of action of stressors and to identify specific biomarkers. Ultimately, early‐warning indicators can then be developed and deployed in “in situ” bioassays and in environmental risk assessment. The number of field experiments or laboratory trials using ecologically relevant test‐species and involving proteomics has been, until recently, insufficient to allow a critical analysis of the real benefits of the application of this approach to ecotoxicology. This article intends to present an overview on the applications of proteomics in the context of ecotoxicology, focusing mainly on the prospective research to be done in invertebrates. Although these represent around 95% of all animal species and in spite of the key structural and functional roles they play in ecosystems, proteomic research in invertebrates is still in an incipient stage. We will review applications of ecotoxicoproteomics by evaluating the technical methods employed, the organisms and the contexts studied, the advances achieved until now and lastly the limitations yet to overcome will be discussed.
Plant secretome: Unlocking secrets of the secreted proteins
Authors: Agrawal Ganesh Kumar , Jwa Nam‐Soo , Lebrun Marc‐Henri , Job Dominique , Rakwal Randeep
Published: December 2009

Plant secretomics is a newly emerging area of the plant proteomics field. It basically describes the global study of secreted proteins into the extracellular space of plant cell or tissue at any given time and under certain conditions through various secretory mechanisms. A combination of biochemical, proteomics and bioinformatics approaches has been developed to isolate, identify and profile secreted proteins using complementary in vitro suspension‐cultured cells and in planta systems. Developed inventories of secreted proteins under normal, biotic and abiotic conditions revealed several different types of novel secreted proteins, including the leaderless secretory proteins (LSPs). On average, LSPs can account for more than 50% of the total identified secretome, supporting, as in other eukaryotes, the existence of novel secretory mechanisms independent of the classical endoplasmic reticulum‐Golgi secretory pathway, and suggesting that this non‐classical mechanism of protein expression is, for as yet unknown reasons, more massively used than in other eukaryotic systems. Plants LSPs, which seem to be potentially involved in the defense/stress responses, might have dual (extracellular and/or intracellular) roles as most of them have established intracellular functions, yet presently unknown extracellular functions. Evidence is emerging on the role of glycosylation in the apical sorting and trafficking of secretory proteins. These initial secretome studies in plants have considerably advanced our understanding on secretion of different types of proteins and their underlying mechanisms, and opened a door for comparative analyses of plant secretomes with those of other organisms. In this first review on plant secretomics, we summarize and discuss the secretome definition, the applied approaches for unlocking secrets of the secreted proteins in the extracellular fluid, the possible functional significance and secretory mechanisms of LSPs, as well as glycosylation of secreted proteins and challenges involved ahead. Further improvements in existing and developing strategies and techniques will continue to drive forward plant secretomics research to building comprehensive and confident data sets of secreted proteins. This will lead to an increased understanding on how cells couple the concerted action of secreted protein networks to their internal and external environments.
The Microbicidal Effect of Low‐Temperature Plasma Generated by Corona Discharge: Comparison of Various Microorganisms on an Agar Surface or in Aqueous Suspension
Authors: Scholtz Vladimír , Julák Jaroslav , Kříha Vítězslav
Published: December 2009

The sensitivity of various microbes to the low temperature plasma generated by negative corona discharge in the point‐to‐plane mode was tested. On the surface of agar semisolid cultivation media, the inhibition zones in microbial cultures were obtained and their areas were compared as a measure of microbicidal effect for nine microbial species including bacterial spores and a yeast species. This experimental arrangement resembles the testing of antibiotic sensitivity by the well‐known disc diffusion technique. The effect of comparable magnitude was found for all vegetative forms, but Candida albicans and Deinococcus radiodurans appeared to be the most and Geobacillus stearothermophilus the least susceptible. The effect on spores was in order of magnitude lesser than on vegetative forms. Following the action of the same plasma on bacteria in aqueous suspensions, the complete sterilization of Escherichia coli was achieved within 120 s and Staphylococcus epidermidis within 4–5 min. On the other hand, the yeast Candida albicans in water appeared to be less susceptible requiring 30 min for its complete inactivation.

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Cyanosis revealing hepatopulmonary syndrome in a child with dyskeratosis congenita
Authors: Renoux M.C. , Mazars N. , Tichit R. , Counil F.
Published: December 2009

We report the case of a 5‐year‐old child with dyskeratosis congenita who presented cyanosis and dyspnea at exertion. He had severe hypoxemia with elevated alveolar‐arterial oxygen gradient in the setting of liver disease. Technetium‐99m‐labeled macroaggregated albumin scan showed abnormally high uptake in the brain, confirming hepatopulmonary syndrome. Pediatr Pulmonol. 2010; 45:99–102. © 2009 Wiley‐Liss, Inc.
Acute pulmonary toxicity following intralesional administration of bleomycin for a lymphovenous malformation
Authors: Atwa Khalid , Abuhasna Said , Shihab Zuhair , Hashaykeh Nidal , Hasan Rashed
Published: December 2009

Objective

To describe the clinical course and treatment of an infant with acute pulmonary toxicity following intralesional administration of bleomycin for a lymphovenous malformation.

Design

Case report.

Setting

A tertiary care University‐affiliated hospital.

Patient, Intervention, and Results

An 8‐month‐old girl developed acute respiratory distress with profound hypoxemia complicated by pneumothorax and pneumomediastinum 1 day following intralesional administration of bleomycin. She was treated with bilateral chest tube insertion, systemic corticosteroids, pentoxifylline, and supportive care. At the most recent follow‐up 5 months after the onset of the respiratory event, the patient is active, walks, and talks without any evidence of pulmonary diseases clinically. This is the youngest infant reported, to date, with acute bleomycin pulmonary toxicity following intralesional administration of bleomycin resulting in acute respiratory insufficiency followed by complete recovery.

Conclusions

This case illustrates the importance of early recognition and aggressive treatment of acute bleomycin toxicity resulting from intralesional administration of this medication for lymphovenous malformations. Pediatr Pulmonol. 2010; 45:192–196. © 2009 Wiley‐Liss, Inc.
Croup presentations to emergency departments in Alberta, Canada: A large population‐based study
Authors: Rosychuk Rhonda J. , Klassen Terry P. , Metes Dan , Voaklander Donald C. , Senthilselvan Ambikaipakan , Rowe Brian H.
Published: December 2009

Background

Croup is a common pediatric respiratory illness. While croup is generally a mild disease, exacerbations may be seen in the Emergency Department (ED) setting. The objective of this study was to describe the epidemiology of croup presentations to EDs made by infants (≤2 years old) in the province of Alberta, Canada.

Methods

The Ambulatory Care Classification System and other Alberta provincial administrative databases were used to obtain all ED encounters for croup during six fiscal years (April 1999 to March 2005). Information extracted included demographics, ED visit timing, and subsequent visits to non‐ED settings. Data analysis included descriptive summaries and directly standardized visit rates.

Results

There were 27,355 ED visits for croup made by 20,019 infants. Most (78.2%) had only one croup‐related ED visit; males (62.3% of ED visits) more commonly presented than females. Biennial trends were apparent in the sex standardized visit rates which increased from 43.4/1,000 in 1999/2000 to 49.6/1,000 in 2003/2004 for odd fiscal years, and from 30.9/1,000 in 2000/2001 to 34.1/1,000 in 2004/2005 for even years. The directly standardized visit rates varied by socio‐economic proxy: generally Welfare recipients had the highest rates, Aboriginals the lowest. Admission occurred in 8.0% of the cases; 5.4% had a repeat ED visit within 7 days following discharge. Overall, 71.9% of individuals had yet to have a non‐ED follow‐up visit by 1 week; the estimated median time to the first follow‐up visit was 33 days (95% CI: 31–36).

Conclusion

Croup is a common presenting problem in Alberta EDs. The important findings include an overall increase in the rates of presentation over the study period, disparities based on age, sex, and socio‐economic/cultural status, and the low rate of early follow‐up. Targeted interventions could be implemented to address specific groups and reduce croup‐related ED visits. Pediatr Pulmonol. 2010; 45:83–91. © 2009 Wiley‐Liss, Inc.
pH‐dependent stability of neuroserpin is mediated by histidines 119 and 138; Implications for the control of β‐sheet A and polymerization
Authors: Belorgey Didier , Hägglöf Peter , Onda Maki , Lomas David A.
Published: December 2009

Neuroserpin is a member of the serpin superfamily. Point mutations in the neuroserpin gene underlie the autosomal dominant dementia, familial encephalopathy with neuroserpin inclusion bodies. This is characterized by the retention of ordered polymers of neuroserpin within the endoplasmic reticulum of neurons. pH has been shown to affect the propensity of several serpins to form polymers. In particular, low pH favors the formation of polymers of both α1‐antitrypsin and antithrombin. We report here opposite effects in neuroserpin, with a striking resistance to polymer formation at acidic pH. Mutation of specific histidine residues showed that this effect is not attributable to the shutter domain histidine as would be predicted by analogy with other serpins. Indeed, mutation of the shutter domain His338 decreased neuroserpin stability but had no effect on the pH dependence of polymerization when compared with the wild‐type protein. In contrast, mutation of His119 or His138 reduced the polymerization of neuroserpin at both acidic and neutral pH. These residues are at the lower pole of neuroserpin and provide a novel mechanism to control the opening of β‐sheet A and hence polymerization. This mechanism is likely to have evolved to protect neuroserpin from the acidic environment of the secretory granules.
Myoglobin strikes back
Authors: Brunori Maurizio
Published: December 2009

Over the last half century, myoglobin (Mb) has been an excellent model system to test a number of concepts, theories, and new experimental methods that proved valuable to investigate protein structure, function, evolution, and dynamics. Mb's function, most often considered just an oxygen repository, has considerably diversified over the last 15 years, especially because it was shown to have a role in the biochemistry of quenching and synthesizing nitric oxide in the red muscle, thereby protecting the cell. To tackle protein's structural dynamics by innovative biophysical methods, Mb has been the best prototype; laser flash technology made it possible to obtain molecular movies by time‐resolved Laue crystallography (with ps resolution). This approach unveiled the complexity of the energy landscape and the structural basis of the stretched interconversion between conformational substates of a protein.
A new structure‐based classification of sulfide:quinone oxidoreductases
Authors: Marcia Marco , Ermler Ulrich , Peng Guohong , Michel Hartmut
Published: December 2009

Sulfide:quinone oxidoreductases (SQR) are ubiquitous membrane‐bound flavoproteins involved in sulfide detoxification, in sulfide‐dependent energy conservation processes and potenatially in the homeostasis of the neurotransmitter sulfide. The first 2 structures of SQRs from the bacterium Aquifex aeolicus (Marcia et al., Proc Natl Acad Sci USA 2009; 106:9625–9630) and the archaeon Acidianus ambivalens (Brito et al., Biochemistry 2009; 48:5613–5622) were determined recently by X‐ray crystallography revealing unexpected differences in the active sites and in flavin adenine dinucleotide binding. Besides the reciprocal differences, they show a different conformation of the active site compared with another sulfide oxidizing enzyme, the flavocytochrome c:sulfide dehydrogenase (FCSD) from Allochromatium vinosum (protein data bank id: 1FCD). In addition to the new structural data, the number of available SQR‐like protein sequences is continuously increasing (Pham et al., Microbiology 2008; 154:3112–3121) and the SQR activity of new members of this protein family was recently proven too (Chan et al., J Bacteriol 2009; 191:1026–1034). In the light of the new data, here we revisit the previously proposed contradictory SQR classification and we define new structure‐based sequence fingerprints that support a subdivision of the SQR family into six groups. Our report summarizes the state‐of‐art knowledge about SQRs and highlights the questions that still remain unanswered. Despite two decades of work already done on these enzymes, new and most exciting discoveries can be expected in the future. Proteins 2010. © 2009 Wiley‐Liss, Inc.
Temperature dependent stability of self‐assembled molecular rows
Authors: Blankenburg S. , Schmidt W. G.
Published: December 2009

Monte Carlo simulations on the basis of first‐principles total‐energy calculations are used to rationalize the formation of well‐separated (∼11 Å) molecular rows of phenylglycine upon co‐adsorption of adenine and phenylglycine on Cu(110) [Chen and Richardson, Nature Materials 2, 324 (2003)].

Adsorption‐induced Friedel oscillations of the substrate charge density give rise a lateral modulation of the adsorption energy sufficiently large to explain the experimental observation of well separated molecular rows at room temperature (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Photoluminescence and surface photovoltage of ethynyl derivative‐terminated Si(111) surfaces
Authors: Yang Florent , Hunger Ralf , Rademann Klaus , Rappich Jörg
Published: December 2009

The electrochemical grafting of ethynyl derivatives on Si(111) surfaces has been investigated by means of pulsed photoluminescence (PL) and surface photovoltage (SPV) techniques. Ethynyl derivatives (ethynyl‐MgCl, ethynyl‐MgBr, propynyl‐MgBr, and phenylethynyl‐MgBr) from Grignard compounds were used. By SPV, a high surface photovoltage signal, UPh, is observed. The halogene in the Grignard reagents influences strongly the electronic properties and the polymerisation process, i.e. Br in the Grignard compound leads to better electronic properties than Cl. The propynyl‐terminated Si surface shows the highest PL intensity and at the same time the weakest UPh signal, i.e. this polymeric layer induces the smallest amount of recombination active defects at the interface but also the smallest change in surface band bending. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Canonical Hamiltonian representation of pseudoenergy in shear flows using counter‐propagating Rossby waves
Authors: Heifetz E. , Harnik N. , Tamarin T.
Published: December 2009

Pseudoenergy serves as a non‐canonical Eulerian Hamiltonian of linearized shear flow systems. It is non‐canonical in the sense that the canonical Hamilton equations cannot be written when the dynamical variable is taken as the (potential) vorticity. Here we apply the counter‐propagating Rossby wave kernel (KRW) perspective to obtain a compact form of the pseudoenergy as a domain integral of the local KRW pseudomomentum carried by the instantaneous KRW phase speed in the mean flow frame of reference. Written this way, with the generalized momenta taken as the KRW pseudomomenta and the generalized coordinates as the instantaneous KRW locations, canonical Hamilton equations can be derived both in their continuous (using functional derivatives) and discrete (using function derivatives) forms.

As a simple example of the insight such a formulation can yield, we reexamine the classical stability transition from Rayleigh to Couette flow. In this transition the instability is lost even though the classical necessary conditions of Fjørtoft and Rayleigh are still satisfied. The pseudoenergy‐KRW formulation allows to interpret the stabilization both as an inability of the KRWs to phase lock constructively, and in terms of the pseudoenergy becoming negative. These two apparent different rationalizations are shown to be essentially one and the same. Copyright © 2009 Royal Meteorological Society
Multi‐metal shell coated with surface modification of polystyrene bead cores to improve its adhesion metal shell
Authors: Lee Jun‐Ho , Lee Youngkwan , Nam Jae‐Do
Published: December 2009

We investigated the delamination problem at the metal‐polymer interface and the mechanical buckling of the metal layer at a localized area of the metallic shell under compression between two parallel plates. First, polystyrene (PS) beads were synthesized by dispersion polymerization and then their sulfonation process. After sequential electroless deposition, the average size of multi‐metal coated sulfonated polystyrene (SPS) bead was ca 4.95 µm. Using the electromechanical indentation, the electrical resistance of a single metal‐coated SPS bead decreased with increasing compressive strain without delamination at the metal‐polymer interface, and its electrical resistance showed 5.65 Ω. Copyright © 2009 John Wiley & Sons, Ltd.
Subzero Glass Transition of Waxy Maize Starch Studied by Differential Scanning Calorimetry
Authors: Sang Yijun , Alavi Sajid , Shi Yong‐Cheng
Published: December 2009

A mixture of waxy maize starch and water (1:2, w/w) was heated in a differential scanning calorimeter (DSC) pan to different temperatures to obtain different degrees of gelatinization. Each pan was then quenched to ‐30°C and rescanned, and the subzero glass transition temperature (Tg′) of the content was determined. A three‐phase model of a starch granule—a mobile amorphous phase, a rigid amorphous phase, and a crystalline phase—was used to interpret results and explain the glass transitions in starch. Waxy maize starch had an onset gelatinization temperature (To) of 61.5°C, peak temperature (Tp) of 70.3°C, and completion temperature (Tc) of 81.7°C. The Tg′ was clearly noted after the starch and water mixture was heated to Tp and Tc, but was small and barely observable when the mixture was heated up to To and immediately cooled to ‐30°C. When the starch and water mixture was heated to 55°C, which was 6°C below the To, and held for 2 h, a Tg′ was observed. Moreover, Tg′ began to appear and was observable if the starch and water mixture was heated to 10°C below gelatinization onset temperature (51°C) and annealed for 2 h without any gelatinization. Further holding at ‐7°C showed a clear subzero glass transition of annealed native starch granules.
Learner error, affectual stimulation, and conceptual change
Authors: Allen Michael
Published: December 2009

Pupils' expectation‐related errors oppose the development of an appropriate scientific attitude towards empirical evidence and the learning of accepted science content, representing a hitherto neglected area of research in science education. In spite of these apparent drawbacks, a pedagogy is described that encourages pupils to allow their biases to improperly influence data collection and interpretation during practical work, in order to provoke emotional responses and subsequent engagement with the science. The usefulness of this approach is borne out quantitatively by findings from a series of three randomized experiments (n = 158) which show superior gains using this pedagogy that are still significant 2 and 3 years after the initial treatment. In addition, pupils who experienced more intense emotions during treatment demonstrated the most gains after 6 weeks. This research is one element of a large‐scale study of expectation‐related observation in school science whose findings impact generally on the proper consideration of empirical evidence and the learning of science content. © 2009 Wiley Periodicals, Inc. J Res Sci Teach 47:151–173, 2010
How “scientific” is science education research?
Authors: Lawson Anton E.
Published: December 2009

The research articles published in the Journal of Research in Science Teaching in 1965, 1975, 1985, 1995, and in 2005 were surveyed to discover the extent to which they were theory driven. Carey and Smith's theory of the development of science epistemologies was used to frame the study. Specifically their theory posits that science epistemologies develop through three developmental levels. Persons at Level 1 view science as an inductive and descriptive enterprise. Persons at Level 2 view science in terms of hypothesis generation and test. Persons at Level 3 see science as theory driven. That is, theories are generated and their postulates are tested via planned tests with predicted consequences and theories are used to generate specific hypotheses, which in turn are tested in a similar manner. Three computer‐generated surveys were conducted on each article identifying articles that contained the words theory, hypothesis, and prediction. The surveys assumed that if the reported research was guided by Level 3 epistemology, then these key terms would be likely to appear somewhere in the article. The term theory was found in only 18.0% of the 1965 articles. Percentages increased in subsequent decades, that is, to 36.5% in 1975, to 44.3% in 1985, to 58.3% in 1995, and then to 86.7% in 2005. Similar, though less dramatic, increases were also found for the terms hypothesis and prediction. Relatively few articles contained two or all three of the terms. Nevertheless, analysis of all 45 research articles appearing in 2005 revealed that most authors were generating and testing hypotheses and/or theories (presumably guided by Levels 2 or 3 epistemology) albeit in a largely implicit and sometimes inconsistent way. Suggestions for improving the quality of research and its reporting are made. © 2009 Wiley Periodicals, Inc. J Res Sci Teach 47:257–275, 2010
Improving teacher questioning in science inquiry discussions through professional development
Authors: Oliveira Alandeom W.
Published: December 2009

This study explores questioning practices adopted by elementary teachers while facilitating science inquiry discussions prior and subsequent to their participation in a summer institute in which they were provided with scholarly descriptions of inquiry‐based teacher questioning (i.e., typologies of questions used by discourse analysts to categorize and understand teacher questioning) and conducted video‐based discourse analysis. Teachers' questioning is examined in light of their social understandings (i.e., how teachers understand social aspects of oral questioning in inquiry‐based science classrooms). The reported findings show that, as a result of developing an increased awareness of social aspects of teacher questioning during the institute, teachers' referential questions (oral queries aimed at encouraging students to articulate their own ideas, understandings, experiences and personal opinions) were twice as frequent after the institute as they were before, hence suggesting an increased degree of student‐centeredness. Furthermore, their student‐centered questions prompted longer and more articulated student responses, promoted higher‐level student thinking, positioned students as complementary experts, prompted students to provide tentative responses, and encouraged students to conduct authentic investigations. Based on these findings, it is argued that educators who set out to prepare teachers to become effective questioners in the context of science inquiry discussions ought to go beyond cognitive issues and the simple provision of static and ill‐defined labels such as “guide” and “active inquirer.” © 2009 Wiley Periodicals, Inc. J Res Sci Teach 47: 422–453, 2010
School trips and classroom lessons: An investigation into teacher–student talk in two settings
Authors: DeWitt Jennifer , Hohenstein Jill
Published: December 2009

Although school trips to informal science institutions can result in conceptual and affective gains, the processes by which they do so are not yet clearly understood. Taking a sociocultural perspective that highlights the importance of discourse for learning, this work focuses on the talk that occurred in teacher–pupil interactions, both during a museum visit and during pre‐ and post‐visit lessons in the classroom. The museum setting affords many experiences not available in a classroom—does it also afford different types of discourse? Transcripts from one secondary and three primary school classes provide evidence of the extent to which teachers' talk conformed to a triadic pattern, with discourse during the pre‐ and post‐visit lessons more closely adhering to this pattern than that during the visit. However, a closer look at teacher–student discourse revealed further complexities, including greater use of open‐ended questions during triadic than during non‐triadic discourse. Overall, the findings from this research indicate that museum visits may enable pupils to assert more authority temporarily and provide insight into processes by which such experiences may contribute to learning. © 2009 Wiley Periodicals, Inc. J Res Sci Teach 47: 454–473, 2010
Gravity wave effects on wind farm efficiency
Authors: Smith R. B.
Published: December 2009

A theory of the atmospheric disturbance caused by a large wind farm is developed using a simple boundary layer (BL) representation. The model includes pressure gradients and gravity wave generation associated with a temperature inversion at the top of the BL and the normal tropospheric lapse rate aloft. The pattern of wind disturbance is computed using a Fast Fourier Transform. The slowing of the winds by turbine drag and the resulting loss of wind farm efficiency is controlled by two factors. First is the size of the wind farm in relation to the restoring effect of friction at the top and bottom of the BL. Second is the role of static stability and gravity waves in the atmosphere above the BL. The effect of the pressure perturbation is to decelerate the wind upstream and to prevent further deceleration over the wind farm with a favorable pressure gradient. As a result, the wind speed reduction is approximately uniform over the wind farm. In spite of the uniform wind over the farm, the average wind reduction is still very sensitive to the farm aspect ratio. In the special case of weak stability aloft, weak friction and the Froude Number $Fr = U\sqrt{g'H}\approx 1$ the wind speed near the farm can suddenly decrease; a phenomenon we call ‘choking’. Copyright © 2009 John Wiley & Sons, Ltd.
Continuous animation and simulation
Authors: Chen Jim X.
Published: December 2009

This paper provides a general introduction to continuous animation and simulation for scientists and engineers who have little background in computer graphics. Topics covered include real‐time animation, simulation, efficiency of animation and simulation, synchronization, physics‐based simulation, and software simulation tools. At the end, an example of continuous simulation of a spider climbing on a spider web is discussed with implementation detail. Copyright © 2009 John Wiley & Sons, Inc.

This article is categorized under:

Statistical and Graphical Methods of Data Analysis > Virtual Reality
Reliability in the 21st century
Authors: Wilson Simon P.
Published: December 2009

This article discusses some current trends in statistical reliability research, many of which have arisen from developments in computational methods. It highlights areas of both methodology and application, where the author believes that there are excellent prospects for interesting and fruitful research in the future, in terms of both methodology and new applications. Copyright © 2009 John Wiley & Sons, Inc.

This article is categorized under:

Statistical and Graphical Methods of Data Analysis > Reliability, Survivability, and Quality Control
Journal of Statistical Computation and Simulation
Authors: Krutchkoff Richard G.
Published: December 2009

Herein you will find the history of the Journal of Statistical Computation and Simulation (JSCS), how it came into being, and what has happened to it from then to now. Copyright © 2009 John Wiley & Sons, Inc.

This article is categorized under:

Applications of Computational Statistics > Organizations and Publications
Coding theory
Authors: Stine Robert A.
Published: December 2009

Coding theory is a portion of information theory concerned with the explicit representation of data as a sequence of symbols, usually a sequence of bits. The entropy of a probability distribution measures the information content of data, giving a lower bound on the number of bits necessary to encode data. Source coding also defines a measure, the divergence, of the cost of using a suboptimal representation. Channel coding describes representations that maximize the rate at which information can be communicated through a noisy medium. Important applications of coding theory include data compression, signal processing, and the comparison of statistical models. Copyright © 2009 Wiley Periodicals, Inc.

This article is categorized under:

Applications of Computational Statistics > Signal and Image Processing and Coding
Combining information
Authors: Piegorsch Walter W. , John Bailer A.
Published: December 2009

The combination of information from diverse sources is a common task encountered in computational statistics. A popular label for analyses involving the combination of results from independent studies is meta‐analysis. The goal of the methodology is to bring together the results of different studies, reanalyze the disparate results within the context of their common endpoints, synthesize where possible into a single summary endpoint, increase the sensitivity of the analysis to detect the presence of adverse effects, and provide a quantitative analysis of the phenomenon of interest based on the combined data. This article discusses some basic methods in meta‐analytic calculations and includes commentary on how to combine or average results from multiple models applied to the same set of data. Copyright © 2009 John Wiley & Sons, Inc.

This article is categorized under:

Applications of Computational Statistics > Defense and National Security
Support vector machines
Authors: Mammone Alessia , Turchi Marco , Cristianini Nello
Published: December 2009

Support vector machines (SVMs) are a family of machine learning methods, originally introduced for the problem of classification and later generalized to various other situations. They are based on principles of statistical learning theory and convex optimization, and are currently used in various domains of application, including bioinformatics, text categorization, and computer vision. Copyright © 2009 John Wiley & Sons, Inc.

This article is categorized under:

Statistical Learning and Exploratory Methods of the Data Sciences > Clustering and Classification
Proximal Interphalangeal Joint Replacement with Surface Replacement Arthroplasty (SR–PIP): Functional Results and Complications
Authors: Luther Christina , Germann Guenter , Sauerbier Michael
Published: December 2009

The purpose of the study was to investigate patients with proximal interphalangeal (PIP) joint replacements regarding postoperative function, pain, complications and incidence of reoperations. From 2000 to 2007, 23 patients (11 male, 12 female) with an average age of 47 years (19–72 years) who had symptomatic posttraumatic (15) or idiopathic arthritis (nine) in 24 PIP joints underwent unconstrained PIP joint replacements (formerly AVANTA, now Small Bone Innovations™). All 23 patients were instructed in special hand exercises starting the first postoperative day. Thirteen of 23 patients had previous operations. The median history of pain was 12 months (2–120). Fourteen of 24 prostheses needed reoperations (58%): teno-arthrolysis (9×), PIP tenodesis (one in three with swan neck deformity) and explantation (four with infections/loosening). The four explantations resulted in a PIP joint arthrodesis in all cases. Twenty-two patients were available for follow-up at an average of 27 months (4–73 months) postoperatively. The median postoperative pinch grip was 7.6 lbs (4–28 lbs), and the disabilities of the arm, shoulder and hand score was 24 (1–58). The active range of motion of the PIP joint was 33° preoperatively (min 0°, max 75°) and 54° postoperatively (min 0°, max 90°). On the Visual Analogue Pain Scale (VAS, range 0–10), seven patients had mild (VAS 1–3) and four moderate pain (VAS 4–7) in the finger on exercise. Seventy percent were overall satisfied with operation and functional results. The results of surface replacement arthroplasty of the PIP joint are overall satisfying; however, postoperative complications and incidence of reoperations are noticeable and should be mentioned to the patients in the preoperative setting.
Elastic intramedullary nailing in unstable fractures of the paediatric tibial diaphysis: A systematic review
Authors: Swindells Mark G. , Rajan R. A.
Published: December 2009

Purpose

The majority of paediatric tibial fractures can be managed conservatively. However, there is a small but significant group of patients that require surgical intervention for several indications, most notably, unstable fractures. There are various surgical options, each with its own advantages and risks. This review establishes the current available evidence for the use of elastic intramedullary nails in this group.

Methods

A systematic review of the currently available literature was performed. The relevant studies were then critically appraised.

Results

Seven applicable retrospective case series were identified, with the outcomes from a total of 210 (range 16–60) patients considered. The mean time to union ranged from 7 to 21 weeks. Reported complications included small numbers each of delayed union, non-union, malunion, leg length discrepancy and infection.

Conclusions

There is only a small body of evidence currently published on this topic. The evidence published so far concludes that elastic intramedullary nailing represents an effective and reliable method to treat an unstable fracture of the tibial diaphysis in the paediatric patient, where conservative management is not appropriate.
The Politics of Skin Color in Brazil
Authors: Mitchell Gladys
Published: December 2009

Race in Brazil was constructed differently than race in the United States. This article traces the historical making of race in Brazil. I also examine recent notions of race and color that acknowledge that blacks and browns are distinctly different than whites when considering social and economic inequalities between the two. Current racial discourse in Brazil includes addressing illnesses such as anemia and diabetes as illnesses that disproportionately affect Afro–Brazilians. Such discourse was unimaginable 30 years ago. A similar racial discourse is present in American society, despite that the two have distinct racial histories. Such a discourse is potentially harmful as social meanings of race are applied to the medical field. By tracing Brazil's history of race, this article sheds light on how race is made in a non north-American context as well as show how such constructions are dangerous at times and useful and pragmatic in other cases.
Biological V. Social Definitions of Race: Implications for Modern Biomedical Research
Authors: Graves Joseph L.
Published: December 2009

Misconceptions concerning the concordance of biological and social definitions of race are ongoing in American society. This problem extends beyond that of the lay public into the professional arena, especially that of biomedical research. This continues, in part, because of the lack of training of many biomedical practitioners in evolutionary thinking. This essay reviews the biological and social definitions of race, examining how understanding the evolutionary mechanisms of disease is crucial to addressing ongoing health disparities. Finally it concludes by laying bear the fallacies of “race-specific” medicine.
Race, Genetics and Health: An Introduction
Authors: Darity William , Royal Charmaine , Whitfield Keith
Published: December 2009

The emergence of putative race-specific or ethnic-specific medicines appears to be overturning a new consensus reached by physical anthropologists that race is a biological fiction. This article examines whether there is substance to the notion that conventional norms of race classification have utility in medical diagnosis and prescription, whether there is legitimacy to notions of race-specific diseases, and whether the genomics revolution promises individualized or racialized medicine. Correspondingly, the article asks how far genetics really can take us in understanding racial health disparities. Finally, the article provides a foreword to four foundational articles in the new field of race, genetics and health.
Antecedents of Ethical Consumption Activities in Germany and the United States
Authors: Witkowski Terrence H. , Reddy Sabine
Published: December 2009

This study developed an index of ethical consumption activities, applied it to samples of young consumers from Germany ( n=225) and the United States ( n=267), and explored the role of national culture and other factors that theoretically determine these behaviors. Contrary to expectations, the German respondents reported fewer ethical consumption activities than did those from the US and female subjects did not consume more ethically than males. Religiosity had only a weak relationship with ethical consumption activities. Consistent with the hypotheses, both respondent idealism and social engagement behaviors were significant predictors of ethical consumption. These findings add to the literature on sustainable consumption and consumer responsibility by challenging conventional understanding of cross-national and gendered differences.
Estradiol and testosterone differently affect visceral pain‐related behavioural responses in male and female rats
Authors: Aloisi Anna Maria , Affaitati Giannapia , Ceccarelli Ilaria , Fiorenzani Paolo , Lerza Rosanna , Rossi Cosmo , Pace Maria Caterina , Chiefari Maria , Aurilio Caterina , Giamberardino Maria Adele
Published: December 2009

In the study of pain, the presence of sex differences is well known, with female subjects being more affected in a number of chronic painful conditions; however, the underlying mechanisms and the involvement of gonadal hormones, are still controversial. This study evaluated visceral pain in a validated rat model of artificial calculosis and the effects of estradiol and testosterone administration. Adult male and female rats were divided into groups and treated with one of the substances or Oil (vehicle) for 5 days, starting 2 days before surgery, with half receiving an artificial calculosis (Stone) and half only a sham (Sham) procedure. The animals’ behaviour (ureteral crises, frequency and duration) were recorded for 72 h; estradiol and testosterone plasma levels were determined in all groups at the end of the observation period. After surgery, only Stone rats showed ureteral pain crises, with a significant sex difference in the Oil‐treated groups in which the number and duration of crises were higher in females than in males. This difference was not present in the estradiol‐treated groups in which ureteral crises were decreased only in females while testosterone treatment had no effect in either sex. Estradiol and testosterone plasma levels were affected by treatments in both sexes. These results confirm that, also in this model of visceral pain, females experience more pain than males; moreover, they show that supraphysiological levels of estradiol, but not of testosterone, are analgesic only in females. A dose and sex‐dependent efficacy of gonadal hormones is suggested and discussed.
Combined effects of endurance training and dietary unsaturated fatty acids on physical performance, fat oxidation and insulin sensitivity
Authors: Boss Andreas , Lecoultre Virgile , Ruffieux Christiane , Tappy Luc , Schneiter Philippe
Published: December 2009

Endurance training improves exercise performance and insulin sensitivity, and these effects may be in part mediated by an enhanced fat oxidation. Since n-3 and n-9 unsaturated fatty acids may also increase fat oxidation, we hypothesised that a diet enriched in these fatty acids may enhance the effects of endurance training on exercise performance, insulin sensitivity and fat oxidation. To assess this hypothesis, sixteen normal-weight sedentary male subjects were randomly assigned to an isoenergetic diet enriched with fish and olive oils (unsaturated fatty acid group (UFA): 52 % carbohydrates, 34 % fat (12 % SFA, 12 % MUFA, 5 % PUFA), 14 % protein), or a control diet (control group (CON): 62 % carbohydrates, 24 % fat (12 % SFA, 6 % MUFA, 2 % PUFA), 14 % protein) and underwent a 10 d gradual endurance training protocol. Exercise performance was evaluated by measuring VO2max and the time to exhaustion during a cycling exercise at 80 % VO2max; glucose homeostasis was assessed after ingestion of a test meal. Fat oxidation was assessed by indirect calorimetry at rest and during an exercise at 50 % VO2max. Training significantly increased time to exhaustion, but not VO2max, and lowered incremental insulin area under the curve after the test meal, indicating improved insulin sensitivity. Those effects were, however, of similar magnitude in UFA and CON. Fat oxidation tended to increase in UFA, but not in CON. This difference was, however, not significant. It is concluded that a diet enriched with fish- and olive oil does not substantially enhance the effects of a short-term endurance training protocol in healthy young subjects.
Insulin release, peripheral insulin resistance and muscle function in protein malnutrition: a role of tricarboxylic acid cycle anaplerosis
Authors: Zoppi Claudio C. , Silveira Leonardo R. , Oliveira Camila A. M. , Boschero Antonio C. , Curi Rui , Carneiro Everardo M.
Published: December 2009

Pancreatic β-cells and skeletal muscle act in a synergic way in the control of systemic glucose homeostasis. Several pyruvate-dependent and -independent shuttles enhance tricarboxylic acid cycle intermediate (TACI) anaplerosis and increase β-cell ATP:ADP ratio, triggering insulin exocytotic mechanisms. In addition, mitochondrial TACI cataplerosis gives rise to the so-called metabolic coupling factors, which are also related to insulin release. Peripheral insulin resistance seems to be related to skeletal muscle fatty acid (FA) accumulation and oxidation imbalance. In this sense, exercise has been shown to enhance skeletal muscle TACI anaplerosis, increasing FA oxidation and by this manner restores insulin sensitivity. Protein malnutrition reduces β-cell insulin synthesis, release and peripheral sensitivity. Despite little available data concerning mitochondrial metabolism under protein malnutrition, evidence points towards reduced β-cell and skeletal muscle mitochondrial capacity. The observed decrease in insulin synthesis and release may reflect reduced anaplerotic and cataplerotic capacity. Furthermore, insulin release is tightly coupled to ATP:ADP rise which in turn is related to TACI anaplerosis. The effect of protein malnutrition upon peripheral insulin resistance is time-dependent and directly related to FA oxidation capacity. In contrast to β-cells, TACI anaplerosis and cataplerosis pathways in skeletal muscle seem to control FA oxidation and regulate insulin resistance.
Tightly-coupled GPS/UWB Integration
Authors: MacGougan Glenn , O'Keefe Kyle , Klukas Richard
Published: December 2009

Ultra-wideband (UWB) ranging radios, an emerging technology that offers precise, short distance range measurements are investigated as a method to augment carrier-phase GPS positioning. A commercially available UWB ranging system is used in a tightly-coupled GPS and UWB real-time kinematic (RTK) system. The performance of the tightly-coupled system is evaluated in static and kinematic testing. This work demonstrates that UWB errors can be successfully estimated in a real-time filter. The results of static testing show that the integrated solution provides better accuracy, better ability to resolve integer ambiguities and enhanced fixed ambiguity solution availability compared with GPS alone. In kinematic testing in a degraded GPS environment, sub-decimetre accuracy was maintained.
Distribution Diagram of Ship Tracks Based on Radar Observation in Marine Traffic Survey
Authors: Yao Cai , Zhengjiang Liu , Zhaolin Wu
Published: December 2009

Marine traffic survey is a fundamental part of marine traffic engineering. In the assessment of the safety or effectiveness in particular water areas, the distribution of ship tracks is always included as one of the most significant results of a marine traffic survey. In this paper, methods of marine traffic survey are discussed and an appropriate method is selected to obtain the traffic data considering the available research circumstances in China. A semi-automatic artificial way of plotting a distribution diagram of ship tracks is presented with illustrations. Details of the diagram plotted by using the collected traffic data are described for reference.
Land Vehicle Navigation with the Integration of GPS and Reduced INS: Performance Improvement with Velocity Aiding
Authors: Han Songlai , Wang Jinling
Published: December 2009

The movement of a land vehicle is constrained because the vehicle always remains on the Earth's surface and only experiences small pitch and roll angles. So the GPS/INS integrated system for land vehicle navigation could be reconfigured to be the integration of GPS and reduced INS to cut down the costs. In a reduced INS, the vertical accelerometer and two horizontal gyros could be omitted from the system. But both theoretical analysis and experimental results show that this configuration may result in the divergence of height solution and large velocity errors. To improve the system performances, precise velocity derived from GPS carrier phase measurements, together with the GPS single point positioning solution, is used to aid the reduced INS. Field test results have demonstrated that first, the aiding from GPS precise velocity overcomes the divergence problem of the integrated height solutions and improves the integrated velocity and secondly the proposed novel integration scheme could achieve comparable navigation accuracy with that from the GPS and full INS integrated system.