bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Temperature on Densification and Deformation Behaviour of Pure Aluminium Powders Processed by Equal Channel Angular Densification and Pressing
Authors: İpekçi Melih Turan , Tekeli Süleyman , Esme Ugur , Kulekci Mustafa Kemal
Published: April 2014

In this study, a dense bulk material was produced from pure aluminum powders by the equal channel angular densification (ECAD) and the equal channel angular pressing (ECAP) method. The combination of densification and ECAD/ECAP tests were carried out at temperatures of 50 °C, 100 °C, and 200 °C, a pressing speed of 1 mms−1, and a pressure in the range of 10–30 metric tons. By using these parameters, for the first time pure aluminum powders were successfully densified into fully bulk materials without additional sintering process. After the ECAD/ECAP tests, the specimens were characterized regarding microstructure, grain size, hardness, and density. The mean grain size was remarkably decreased with an increasing ECAP pass number. With the application of the ECAD/ECAP process, the severe plastic deformation entails that the particles are consolidated into fully dense materials at much lower temperatures and shorter times, as compared to the conventional sintering process. Finally, determining the effective ECAP temperature was very important to control the nano-scaled microstructure, hardness, and density, repectively.
Synthesis and Application of Esterified Starch-g-Polylactic Acid as Drug Carriers
Authors: Yang Xiaolin , Jiang Yufeng , Li Wen , Chen Yanning , Chen Yue
Published: April 2014

A novel copolymer was synthesized by modifying starch-g-polylactic acid (MSt-g-PLA). The results indicated that the starch was efficiently esterified by maleic anhydride (MAH) (2 wt.-%) with polyethylene glycol-400 (PEG-400, 1 wt.-%) as dispersant. Then MSt-g-PLA was synthesized by the reaction of modified starch with D,L-lactic acid. The copolymer was amphiphilic and its molecular weight was 4.789 × 104 (Mn), molecular weight distribution was 6.921 × 104 (Mw), and polydispersity index was 1.445 (PDI), respectively. Subsequently, CTX/MSt-g-PLA microspheres containing the model drug and cefotaxime sodium (CTX) were prepared. The appearance of the microspheres was smooth and regular. 90 % of particle size was under 150.3 μm and mean diameter was 99.3 μm. The degradation rates of microspheres increased with the increase of pH-value of the buffer. With the amphiphilic copolymer MSt-g-PLA as drug carrier, the microspheres had no burst during drug release, and had the similar sustainable release as the PLA carriers.
Effect of Residual Stresses and Inclusion Size on Fatigue Resistance of Parabolic Steel Springs
Authors: Gubeljak Nenad , Predan Jožef , Senčič Bojan , Chapetti Mirco Daniel
Published: April 2014

The effect of inclusion size and residual stresses of spring steel grade 51CrV4 on fatigue lifetime in high cycle was investigated by experimental results obtained by fatigue testing. Since spring with obvious surface defects or inclusions at the surface are failed during pre-stress, the residual stress profile under surface becomes relevant for fatigue crack initiation and failure. Investigation shows that fatigue threshold for high cycle fatigue depends, besides residual stresses, on inclusion size and material hardness. In order to determine allowed size of inclusions in spring steel and the influence of residual stresses, the Murakami's and Chapetti's models and concepts have been used. The stress loading limit regarding inclusion size and applied stress has been determined for loading ratio R = −1 and 0.1 on specimens with and without residual stresses.
Sheffield's Great Flood of 1864: Engineering Failure and the Municipalisation of Water
Authors: Ewen Shane
Published: April 2014

Recent scholarly research at the intersection of the histories of technology and the built environment has revealed many tensions surrounding the design, building and management of major socio-technologies like urban waterworks. There remains much scope for research into the interdependence of socio-technological systems, engineering knowledge and the political and commercial agendas of municipal governments and private water suppliers respectively. In particular, the short- and long-term impact of reservoir disasters - examined in detail here through the case of Sheffield's 'great flood' of March 1864, in which over 250 people lost their lives - on the ownership and control of urban waterworks reveals many conflicts within the engineering profession, as well as the urban community itself, about the causes and consequences of socio-technological failure in the mid-nineteenth century. Using a rich variety of municipal, legal and commercial archival records, as well as contemporary newspapers, this article examines the competing interests involved in negotiating the long-term municipalisation of water supplies and concludes that greater attention should be paid to the influence of man-made disasters and engineering actors in this political game.
'Never such weather known in these seas': Climatic Fluctuations and the Anglo-Dutch Wars of the Seventeenth Century, 1652-1674
Authors: Degroot Dagomar
Published: April 2014

In the North Sea region, the so-called Little Ice Age reached a cold, stormy nadir between 1560 and 1720, with a three-decade interruption of warmer, more tranquil weather between 1629 and 1662. Newly considered ship logbooks, diaries and other documentary evidence suggest that a rise in the frequency of easterly winds accompanied the coldest phases of the Little Ice Age, and these decadal climatic trends had consequences for regional warfare. Fought between 1652 and 1674, the Anglo-Dutch wars at sea were contested in a period of transition between decade-scale climatic regimes and consequently provide useful case studies into the relationship between meteorological trends and early modern military operations. In the first war, persistent westerly winds born of a warmer climate frequently helped crews aboard larger English warships set the terms of most naval engagements. However, during the second and third wars more frequent easterlies stimulated by a cooler climate granted critical advantages to Dutch fleets that had adopted elements of English tactics and technology. Ultimately, the changing climate of the Little Ice Age must be considered alongside human agency and the political, economic or cultural influences typically examined by military historians to explain the course of early modern warfare.
Challenges and Prospects for Helper-Dependent Adenoviral Vector-Mediated Gene Therapy
Authors: Piccolo Pasquale , Brunetti-Pierri Nicola
Published: April 2014

Helper-dependent adenoviral (HDAd) vectors that are devoid of all viral coding sequences are promising non-integrating vectors for gene therapy because they efficiently transduce a variety of cell types in vivo, have a large cloning capacity, and drive long-term transgene expression without chronic toxicity. The main obstacle preventing clinical applications of HDAd vectors is the host innate inflammatory response against the vector capsid proteins that occurs shortly after intravascular vector administration and result in acute toxicity, the severity of which is dose dependent. Intense efforts have been focused on elucidating adenoviral vector–host interactions and the factors involved in the acute toxicity. This review focuses on the recent acquisition of data on such interactions and on strategies investigated to improve the therapeutic index of HDAd vectors.
Precipitation of Phosphate Minerals by Microorganisms Isolated from a Fixed-Biofilm Reactor Used for the Treatment of Domestic Wastewater
Authors: Rivadeneyra Almudena , Gonzalez-Martinez Alejandro , Gonzalez-Lopez Jesus , Martin-Ramos Daniel , Martinez-Toledo Maria , Rivadeneyra Maria
Published: April 2014

The ability of bacteria isolated from a fixed-film bioreactor to precipitate phosphate crystals for the treatment of domestic wastewater in both artificial and natural media was studied. When this was demonstrated in artificial solid media for crystal formation, precipitation took place rapidly, and crystal formation began 3 days after inoculation. The percentage of phosphate-forming bacteria was slightly higher than 75%. Twelve major colonies with phosphate precipitation capacity were the dominant heterotrophic platable bacteria growing aerobically in artificial media. According to their taxonomic affiliations (based on partial sequencing of the 16S rRNA), the 12 strains belonged to the following genera of Gram-negative bacteria: Rhodobacter, Pseudoxanthobacter, Escherichia, Alcaligenes, Roseobacter, Ochrobactrum, Agromyce, Sphingomonas and Paracoccus. The phylogenetic tree shows that most of the identified populations were evolutionarily related to the Alphaproteobacteria (91.66% of sequences). The minerals formed were studied by X-ray diffraction, scanning electron microscopy (SEM), and energy dispersive X-ray microanalysis (EDX). All of these strains formed phosphate crystals and precipitated struvite (MgNH4PO4·6H2O), bobierrite [Mg3(PO4)2·8H2O] and baricite [(MgFe)3(PO4)2·8H2O]. The results obtained in this study show that struvite and spherulite crystals did not show any cell marks. Moreover, phosphate precipitation was observed in the bacterial mass but also near the colonies. Our results suggest that the microbial population contributed to phosphate precipitation by changing the media as a consequence of their metabolic activity. Moreover, the results of this research suggest that bacteria play an active role in the mineral precipitation of soluble phosphate from urban wastewater in submerged fixed-film bioreactors.
Effects of Pansharpening on Vegetation Indices
Authors: Johnson Brian
Published: April 2014

This study evaluated the effects of image pansharpening on Vegetation Indices (VIs), and found that pansharpening was able to downscale single-date and multi-temporal Landsat 8 VI data without introducing significant distortions in VI values. Four fast pansharpening methods—Fast Intensity-Hue-Saturation (FIHS), Brovey Transform (BT), Additive Wavelet Transform (AWT), and Smoothing Filter-based Intensity Modulation (SFIM)—and two VIs—Normalized Difference Vegetation Index (NDVI) and Simple Ratio (SR)—were tested. The NDVI and SR formulas were both found to cause some spatial information loss in the pansharpened multispectral (MS) bands, and this spatial information loss from VI transformations was not specific to Landsat 8 imagery (it will occur for any type of imagery). BT, SFIM, and other similar pansharpening methods that inject spatial information from the panchromatic (Pan) band by multiplication, lose all of the injected spatial information after the VI calculations. FIHS, AWT, and other similar pansharpening methods that inject spatial information by addition, lose some spatial information from the Pan band after VI calculations as well. Nevertheless, for all of the single- and multi-date VI images, the FIHS and AWT pansharpened images were more similar to the higher resolution reference data than the unsharpened VI images were, indicating that pansharpening was effective in downscaling the VI data. FIHS best enhanced the spectral and spatial information of the single-date and multi-date VI images, followed by AWT, and neither significantly over- or under-estimated VI values.
Interleukin-6 Receptor rs7529229 T/C Polymorphism Is Associated with Left Main Coronary Artery Disease Phenotype in a Chinese Population
Authors: He Feng , Teng Xiao , Gu Haiyong , Liu Hanning , Zhou Zhou , Zhao Yan , Hu Shengshou , Zheng Zhe
Published: April 2014

Left main coronary artery disease (LMCAD) is a particular severe phenotype of coronary artery disease (CAD) and heritability. Interleukin (IL) may play important roles in the pathogenesis of CAD. Although several single nucleotide polymorphisms (SNPs) identified in IL related genes have been evaluated for their roles in inflammatory diseases and CAD predisposition, the investigations between genetic variants and CAD phenotype are limited. We hypothesized that some of these gene SNPs may contribute to LMCAD phenotype susceptibility compared with more peripheral coronary artery disease (MPCAD). In a hospital-based case-only study, we studied IL-1A rs1800587 C/T, IL-1B rs16944 G/A, IL-6 rs1800796 C/G, IL-6R rs7529229 T/C, IL-8 rs4073 T/A, IL-10 rs1800872 A/C, and IL-10 rs1800896 A/G SNPs in 402 LMCAD patients and 804 MPCAD patients in a Chinese population. Genotyping was done using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and ligation detection reaction (LDR) method. When the IL-6R rs7529229 TT homozygote genotype was used as the reference group, the CC or TC/CC genotypes were associated with the increased risk for LMCAD (CC vs. TT, adjusted odds ratio(OR) = 1.46, 95% confidence interval (CI) = 1.02–2.11, p = 0.042; CC + TC vs. TT, adjusted OR = 1.31, 95% CI = 1.02–1.69, p = 0.037). None of the other six SNPs achieved any significant differences between LMCAD and MPCAD. The present study suggests that IL-6R rs7529229 T/C functional SNP may contribute to the risk of LMCAD in a Chinese population. However, our results were limited. Validation by a larger study from a more diverse ethnic population is needed.
l-Leucine Supplementation Worsens the Adiposity of Already Obese Rats by Promoting a Hypothalamic Pattern of Gene Expression that Favors Fat Accumulation
Authors: Zampieri Thais , Torres-Leal Francisco , Campaña Amanda , Lima Fabio , Donato Jose
Published: April 2014

Several studies showed that l-leucine supplementation reduces adiposity when provided before the onset of obesity. We studied rats that were exposed to a high-fat diet (HFD) for 10 weeks before they started to receive l-leucine supplementation. Fat mass was increased in l-leucine-supplemented rats consuming the HFD. Accordingly, l-leucine produced a hypothalamic pattern of gene expression that favors fat accumulation. In conclusion, l-leucine supplementation worsened the adiposity of rats previously exposed to HFD possibly by central mechanisms.
Monocular SLAM for Autonomous Robots with Enhanced Features Initialization
Authors: Guerra Edmundo , Munguia Rodrigo , Grau Antoni
Published: April 2014

This work presents a variant approach to the monocular SLAM problem focused in exploiting the advantages of a human-robot interaction (HRI) framework. Based upon the delayed inverse-depth feature initialization SLAM (DI-D SLAM), a known monocular technique, several but crucial modifications are introduced taking advantage of data from a secondary monocular sensor, assuming that this second camera is worn by a human. The human explores an unknown environment with the robot, and when their fields of view coincide, the cameras are considered a pseudo-calibrated stereo rig to produce estimations for depth through parallax. These depth estimations are used to solve a related problem with DI-D monocular SLAM, namely, the requirement of a metric scale initialization through known artificial landmarks. The same process is used to improve the performance of the technique when introducing new landmarks into the map. The convenience of the approach taken to the stereo estimation, based on SURF features matching, is discussed. Experimental validation is provided through results from real data with results showing the improvements in terms of more features correctly initialized, with reduced uncertainty, thus reducing scale and orientation drift. Additional discussion in terms of how a real-time implementation could take advantage of this approach is provided.
Time-Resolved Photoluminescence Spectroscopy and Imaging: New Approaches to the Analysis of Cultural Heritage and Its Degradation
Authors: Nevin Austin , Cesaratto Anna , Bellei Sara , D'Andrea Cosimo , Toniolo Lucia , Valentini Gianluca , Comelli Daniela
Published: April 2014

Applications of time-resolved photoluminescence spectroscopy (TRPL) and fluorescence lifetime imaging (FLIM) to the analysis of cultural heritage are presented. Examples range from historic wall paintings and stone sculptures to 20th century iconic design objects. A detailed description of the instrumentation developed and employed for analysis in the laboratory or in situ is given. Both instruments rely on a pulsed laser source coupled to a gated detection system, but differ in the type of information they provide. Applications of FLIM to the analysis of model samples and for the in-situ monitoring of works of art range from the analysis of organic materials and pigments in wall paintings, the detection of trace organic substances on stone sculptures, to the mapping of luminescence in late 19th century paintings. TRPL and FLIM are employed as sensors for the detection of the degradation of design objects made in plastic. Applications and avenues for future research are suggested.
Tracing Monotreme Venom Evolution in the Genomics Era
Authors: Whittington Camilla , Belov Katherine
Published: April 2014

The monotremes (platypuses and echidnas) represent one of only four extant venomous mammalian lineages. Until recently, monotreme venom was poorly understood. However, the availability of the platypus genome and increasingly sophisticated genomic tools has allowed us to characterize platypus toxins, and provides a means of reconstructing the evolutionary history of monotreme venom. Here we review the physiology of platypus and echidna crural (venom) systems as well as pharmacological and genomic studies of monotreme toxins. Further, we synthesize current ideas about the evolution of the venom system, which in the platypus is likely to have been retained from a venomous ancestor, whilst being lost in the echidnas. We also outline several research directions and outstanding questions that would be productive to address in future research. An improved characterization of mammalian venoms will not only yield new toxins with potential therapeutic uses, but will also aid in our understanding of the way that this unusual trait evolves.
La substitution de l’exposition à l’oeuvre
Authors: Montagnon Florence
Published: April 2014

Tratamos en este texto del fenómeno siguiente : la exposición no solo presenta obras, sino que se muestra ella misma. Revela esto un cambio paradigmatico en el arte contemporáneo. Analizamos las nuevas prácticas de los comisarios de exposiciones cuando son también artistas. Esto interroga las fronteras entre obra y exposición ¿ Puede un artista olvidar sus competencias plásticas cuando actúa como comisario ? Antes, los artistas parecían controlar su práctica y su producción final. Pero ahora, la obra siempre parece escapar al artista como persona individual, para volverse en una producción colectiva que nadie domina completamente. La evolución de las prácticas de comisarios de exposiciones sigue la transformación de la obra y de la exposición, y el traspaso de atención, del contenido hasta el dispositivo de muestra.

Título : La substitución de la obra por la exposición.
Structure elucidation of female-specific volatiles released by the parasitoid wasp Trichogramma turkestanica (Hymenoptera: Trichogrammatidae)
Authors: Tröger Armin , van Beek Teris A , Huigens Martinus E , Silva Isabel M M S , Posthumus Maarten A , Francke Wittko
Published: April 2014

Females of the parasitoid wasp Trichogramma turkestanica produce the putative polydeoxypropionates (2E,4E,6S,8S,10S)-4,6,8,10-tetramethyltrideca-2,4-diene and (2E,4E,6S,8S,10S)-4,6,8,10-tetramethyltrideca-2,4-dien-1-ol or their enantiomers as sex specific volatiles. The structures were assigned on the basis of GC–MS investigations using synthetic reference compounds.
Arthroplasty Rates Are Increased Among US Patients with Systemic Lupus Erythematosus: 1991–2005
Authors: Mertelsmann-Voss Christina , Lyman Stephen , Pan Ting Jung , Goodman Susan , Figgie Mark P. , Mandl Lisa A.
Published: April 2014

Objective.

To evaluate population-based systemic lupus erythematosus (SLE) arthroplasty rates and compare them with rates in patients with no inflammatory or autoimmune conditions.

Methods.

Administrative hospital discharge databases from 10 American states were used to compare knee, hip, and shoulder arthroplasty rates from 1991 to 2005 in patients with SLE and in patients with no inflammatory or autoimmune conditions.

Results.

Arthroplasties were performed on patients with SLE (n = 4253) and patients with noninflammatory conditions (n = 2,762,660). Arthroplasty rates for patients with noninflammatory conditions almost doubled from 1991 to 2005 (124.5 cases/100,000 persons vs 247.5/100,000; p < 0.001). A similar trend was observed for SLE (0.17/100,000 vs 0.38/100,000; p < 0.001). The mean age at arthroplasty in patients with noninflammatory conditions decreased (71.5 ± 11.8 vs 69.0 ± 12.0; p < 0.001), whereas the mean age in patients with SLE increased (47.3 ± 17.0 vs 56.8 ± 16.0; p < 0.001). When stratified by age and sex, arthroplasty in cases of SLE increased in all groups except for women < 44 years old. In 1991, osteonecrosis accounted for 53% and osteoarthritis (OA) 23% of cases of SLE; by 2005 this relationship had reversed, with osteonecrosis accounting for 24% and OA 61% of cases of SLE.

Conclusion.

From 1991 to 2005, arthroplasty rates increased in patients with SLE in similar proportions to overall joint replacement rates. The age of patients with SLE arthroplasty increased and fewer cases were due to osteonecrosis. These data suggest significant changes are occurring — patients with SLE are now living long enough to develop OA and are healthy enough to undergo elective surgery.
Longterm Treatment with Endothelin Receptor Antagonist Bosentan and Iloprost Improves Fingertip Blood Perfusion in Systemic Sclerosis
Authors: Cutolo Maurizio , Ruaro Barbara , Pizzorni Carmen , Ravera Francesca , Smith Vanessa , Zampogna Giuseppe , Paolino Sabrina , Seriolo Bruno , Cimmino Marco , Sulli Alberto
Published: April 2014

Objective.

To evaluate the longterm effects of endothelin-1 (ET-1) antagonism on peripheral blood perfusion (PBP) in patients with systemic sclerosis (SSc).

Methods.

Twenty-six patients with SSc already receiving cyclic intravenous iloprost (ILO) for severe Raynaud phenomenon were enrolled. Thirteen patients continued the treatment for a further 3 years (ILO group) and 13 patients, because of the appearance of digital ulcers, received in addition bosentan (BOS; 125 mg twice/day) for 3 years (ILO + BOS group). Both PBP at fingertips and nailfold microangiopathy were evaluated yearly by laser Doppler flowmetry and nailfold videocapillaroscopy, respectively.

Results.

A progressive significant increase of PBP was observed in the ILO + BOS group during the 3 followup years (p = 0.0007, p = 0.0002, p = 0.01, respectively). In contrast, an insignificant progressive decrease of PBP was observed in the ILO group. Difference of perfusion between the PBP evaluations at basal temperature and at 36°C (to test capillary dilation capacity), was found progressively decreased during the 3-year followup only in the ILO group (p = 0.05, p = 0.26, p = 0.09, respectively). A progressive increase of nailfold capillary number was observed only in the ILO + BOS group after 2 and 3 years of followup (p = 0.05).

Conclusion.

Longterm treatment of SSc patients with ET-1 antagonism, in combination with ILO, seems to increase fingertip blood perfusion, as well as both capillary dilation capacity and number.
Minutes finales : la représentation du Brésil lors de la cérémonie de clôture des Jeux olympiques 2012
Authors: Freitas Ricardo Ferreira , Lins Flávio , Carmo dos Santos Maria Helena
Published: April 2014

Cet article analyse la présentation du Brésil lors de la cérémonie de clôture des Jeux olympiques de Londres 2012. Pendant près de huit minutes, divers artistes brésiliens se sont relayés dans un spectacle fait de clichés qui montraient des chansons, des costumes et des chorégraphies, tous représentatifs, du point de vue médiatique, de la culture nationale. Selon nous, les sons et les images de la méga-manifestation à laquelle ont assisté des millions de personnes autour du monde, jouent un rôle important dans la (re)construction d’imaginaires sur le Brésil, premier pays d’Amérique du Sud à abriter les Jeux olympiques.
Mouvement étudiant québécois et mythe du pouvoir. L'énigme du Sphinx et l'entrée en société
Authors: Boudreault Pierre-W.
Published: April 2014

La lutte étudiante du printemps 2012 au Québec ne peut pas être considérée comme une révolte de la jeunesse réduite à l’expression typique de la génération des « enfants-rois ». Par sa durée et son effervescence politique, ne révèle-t-elle pas une transformation sociale dont il faut détecter les signes spécifiques par l’étude de leur action collective que l’on a nommée « Printemps érable » ?
Totem et technologie communielle
Authors: Huguet Thibault
Published: April 2014

Nous ne pouvons saisir ce qui est en jeu dans les relations humaines contemporaines sans approcher les Nouvelles Technologies de l’Information et de la Communication sous un angle anthropologique. À ce titre, nous interrogeons ici le rôle et les fonctions des écrans numériques, dans ce qu’ils ont d’universel et de particulier : tout comme le totem se révèle être l’essence d’institutions totales particulières, les écrans sont aujourd’hui au cœur d’un processus instituant. La technologie numérique révolutionne l’être-ensemble et l’être-au-monde lorsque les pratiques sociales sont investies de significations imaginaires particulières ; et les différentes composantes de nos identités sociales prennent corps, à travers l’expression de nos craintes, de nos désirs, de nos aspirations, dans des structures de pertinence dont l’écran est le principal médium.
A laboratory study to determine the effect of surface area and bead diameter on NMR relaxation rates of glass bead packs
Authors: Keating Kristina
Published: April 2014

A laboratory study was conducted to explore the relationship between pore size, pore surface‐area‐to‐volume ratio and NMR relaxation rates and to determine which geometric parameter best predicts the average NMR relaxation rate. NMR relaxation measurements were collected on water‐saturated glass beads with controlled sets of bead diameters and surface areas. Four sets of beads were used with average diameters ranging from 55‐1125 m. The surface areas of the glass beads were altered by chemically treating the beads with a weak acid, a strong base and a cream commonly used to etch glass surfaces. Following the chemical treatments, the surface areas of the beads were quantified with krypton BET gas adsorption measurements. It was found that, for the range of bead diameters used in this study, relaxation did not strictly occur in the fast diffusion regime and, as such, the relaxation time associated with the peak of the largest mode in the distribution was found to more accurately represent the pore‐scale geometry than the mean log relaxation time. Using the relaxation time associated with this peak, the results from this study show that the pore surface‐area‐to‐volume ratio is a significantly better predictor of the surface relaxation rate than the mean grain radius ( = 0.014).
The Rise of Telcos and Africa's Knowledge Society
Authors: Amoah Lloyd G. Adu
Published: April 2014

The growing penetration of mobile telephony in Africa reflects arguably the continent's increasing embeddedness into the concourses of the rapidly evolving global high technology environment. The mobile telephony sphere in Africa therefore holds the greatest potential for connecting people, government, business, and the third sector in the ways contemplated by the idea of societies in which knowledge creation, manipulation, storage, and transmission is central for growth and development. It should be clear then that the sophistication of mobile telephony policy takes on a peculiar salience for Africa's high technological leap in the coming decades. This chapter argues that the recent emergence of telecommunication chambers in African countries must be seen as a key loop in crafting mobile telephony policies that respond deftly to current developmental challenges and positions Africa for the future. Focusing on existing African telchambs, the chapter surveys their emergence, analyzes the empirics of their interface with policymakers, and provides directions for the future.
Towards an Interactive E-Government System in Sub-Saharan Africa
Authors: Conteh Charles , Smith Greg
Published: April 2014

Governments worldwide, including those in Africa, are embracing the promises and prospects of electronic service delivery (or e-government). In particular, countries in Sub-Saharan Africa are moving towards adopting system-wide Integrated Communication Technology (ICT) and Enterprise Content Management (ECM) systems to support Electronic Government (EG) services. There are reasons to believe that Africa stands at the threshold of a new experience in this century, but there are also considerable challenges ahead. This chapter examines some of the prospects and challenges of the continent's adoption of Electronic Government. The discussion focuses on the rationale and characteristics of e-government in Africa, as well as its strengths and weaknesses, with particular reference to two countries in the region – Ghana and Kenya. The chapter concludes with a synopsis of some of the key issues as well as salient lessons to highlight the broader future challenges and prospects of e-government in Africa.
Evolution and hydrocarbon potential of the Queen Charlotte Basin, British Columbia
Authors: Woodsworth G J
Published: April 2014

The stratigraphic succession of the Queen Charlotte Islands is composed of two, lithologically distinct, tectonostratigraphic packages. The older package comprises the classic Wrangellian succession: a thick sequence of Upper Triassic vol
Shopper typologies amongst a Generation Y consumer cohort and variations in terms of age in the fashion apparel market
Authors: Mafini Chengedzai , Dhurup Manillall , Mandhlazi Lawrence
Published: April 2014

Purpose: The primary purpose of the study was to examine Generation Y consumer shopper typologies. The secondary purpose was to establish the influence of age in the identified shopper typologies.Rational: Marketers have ever been concerned with the behaviour of consumers. Generation Y consumers have emerged as an important marketing segment. Consequently, a need exists to investigate behavioural issues pertaining to this age cohort on a continuous basis.Methodology: A survey questionnaire was administered to a convenient sample of 230 Generation Y consumers of fashion apparel. Exploratory factor analysis was used to identify shopper typologies. The Kruskal-Wallis test was used to examine the influence of age on the identified shopper typologies.Findings: The study identified seven shopper typologies that are applicable to the Generation Y cohort. These are quality conscious, brand conscious, novelty seeking, hedonistic, confused by over-choice, habitual, brand loyal and fashion conscious shopper typologies. The study also revealed that younger consumers were found to be more confused by over-choice than their older counterparts.Value of research: These findings may enable marketers to understand and predict the purchase behaviour of Generation Y consumers, thereby facilitating the development and implementation of more effective marketing strategies.
Role of cyanoacrylate glue therapy in enteral SEMS bleeding - A nightmare
Authors: Mohanprasad Virukalpatti Goparathinam , Patil Praveen , Prasad Madhura , Shanker Gokul Kruba
Published: April 2014

Over the past century, the use of stents has evolved to a point where they are now used extensively throughout the gastrointestinal tract. Endoscopic stenting has become widely used for treatment of gastrointestinal and hepatobiliary strictures. Metallic stents are deployed in malignant strictures as a palliative procedure. Adverse events of stenting include perforation, migration, bleeding, occlusion, and pain. Finally, the use of multidisciplinary teams which include endoscopists, interventional radiologists, and surgeons allows for the exchange of ideas and procedural planning necessary for successful innovation. We present a case of successful cessation of bleeding by using cyanoacrylate glue therapy in post-enteral self-expandable metallic stent bleeding. In conclusion, glue therapy may also be considered as a mode of treatment other than conservative approach and angiographic coil embolization.
Open safety pin ingestion - Usual method of removal in an unusual way
Authors: G. Sathya , R. Balamurali , P. Ganesh , S. Jeevankumar
Published: April 2014

Single foreign body ingestion is a common scenario that is commonly encountered by gastroenterologists. The symptoms tend to be nonspecific and most of the foreign bodies pass spontaneously. Ingestion of sharp foreign bodies is also not uncommon. It can lead to complications like impaction or perforation. Most of these ingested foreign bodies can be retrieved with endoscopy. We report a 25-year-old patient who underwent successful endoscopic removal of an open safety pin that was ingested accidentally 3 months previously and was impacted at the junction of first and second parts of the duodenum, using a side-view duodenoscope. The presentation of a sharp foreign body without complications which is impacted for 3 months is unusual and its endoscopic extraction without complication is equally uncommon.
Nonlinear Optical Microscopy Signal Processing Strategies in Cancer
Authors: Adur Javier , Carvalho Hernandes F. , Cesar Carlos L. , Casco Victor H.
Published: April 2014

This work reviews the most relevant present-day processing methods used to improve the accuracy of multimodal nonlinear images in the detection of epithelial cancer and the supporting stroma. Special emphasis has been placed on methods of non linear optical (NLO) microscopy image processing such as: second harmonic to autofluorescence ageing index of dermis (SAAID), tumor-associated collagen signatures (TACS), fast Fourier transform (FFT) analysis, and gray level co-occurrence matrix (GLCM)-based methods. These strategies are presented as a set of potential valuable diagnostic tools for early cancer detection. It may be proposed that the combination of NLO microscopy and informatics based image analysis approaches described in this review (all carried out on free software) may represent a powerful tool to investigate collagen organization and remodeling of extracellular matrix in carcinogenesis processes.
The Brauer group and the Brauer–Manin set of products of varieties
Authors: Skorobogatov Alexei N. , Zarhin Yuri G.
Published: April 2014

Let

X

and

Y

be smooth and projective varieties over a field

k

finitely generated over

\mathbb Q

, and let $$ and

\bar Y

be the varieties over an algebraic closure of

k

obtained from

X

and

Y

, respectively, by extension of the ground field. We show that the Galois invariant subgroup of

\mathrm{Br}(\bar X)\oplus \mathrm{Br}(\bar Y)

has finite index in the Galois invariant subgroup of

\mathrm{Br}(\bar X\times\bar Y)

. This implies that the cokernel of the natural map

\mathrm{Br} (X)\oplus\mathrm{Br} (Y)\to \mathrm{Br}(X\times Y)

is finite when

k

is a number field. In this case we prove that the Brauer–Manin set of the product of varieties is the product of their Brauer–Manin sets.
Barenblatt solutions and asymptotic behaviour for a nonlinear fractional heat equation of porous medium type
Authors: Vázquez Juan Luis
Published: April 2014

We establish the existence, uniqueness and main properties of the fundamental solutions for the fractional porous medium equation introduced in [51]. They are self-similar functions of the form

u(x,t) = t^{–\alpha} f(|x| t^{–\beta})

with suitable

α

and

β

. As a main application of this construction, we prove that the asymptotic behaviour of general solutions is represented by such special solutions. Very singular solutions are also constructed. Among other interesting qualitative properties of the equation we prove an Aleksandrov reflection principle.
On the singular values of random matrices
Authors: Mendelson Shahar , Paouris Grigoris
Published: April 2014

We present an approach that allows one to bound the largest and smallest singular values of an

N \times n

random matrix with iid rows, distributed according to a measure on

\mathbb R^n

that is supported in a relatively small ball and linear functionals are uniformly bounded in

L_p

for some

p>8

, in a quantitative (non-asymptotic) fashion. Among the outcomes of this approach are optimal estimates of

1 \pm c\sqrt{n/N}

not only in the case of the above mentioned measure, but also when the measure is log-concave or when it a product measure of iid random variables with "heavy tails".
Erythema Exsudativum Multiforme after a Leishmania Skin Test
Authors: Wind Bas S. , Guimarães Luiz H. , Machado Paulo R. L.
Published: April 2014

A 45-year-old otherwise healthy male from an endemic region for Leishmania braziliensis infection in Bahia, Brazil, presented with three erosive hemorrhagic infiltrated plaques on the left shin accompanied with lymphadenopathy in the groin since one month (Figure 1). A Leishmania skin test performed on the left forearm was strongly positive (20 × 18 mm).1 Two days later, the patient felt sick and feverish. Painful erythematous target lesions developed on the palms and scapula together with conjunctivitis (Figure 2). Histopathology confirmed erythema exsudativum multiforme (EEM) (Figure 3). Both EEM and cutaneous leishmaniasis were successfully treated with a 5-day course of prednisone 20 mg, and a 20-day course of intravenous pentavalent antimony, respectively.
Residents-as-Teachers Publications: What Can Programs Learn From the Literature When Starting a New or Refining an Established Curriculum?
Authors: Bree Kelly K. , Whicker Shari A. , Fromme H. Barrett , Paik Steve , Greenberg Larrie
Published: April 2014

Background

Teaching residents how to teach is a critical part of resident education because residents are often the major teachers of medical students. The importance of formal residents-as-teachers (RAT) curricula has been emphasized throughout the literature, yet not all residency programs have such a curriculum in place.

Objective

The purpose of our study was to (1) review the medical education literature for established RAT curricula, (2) assess published curricula's reproducibility, (3) evaluate the type of outcomes achieved using the Kirkpatrick model of evaluation, and (4) identify curricula that training programs could feasibly adopt.

Methods

We performed a literature review using PubMed, Medline, Scopus, PsycINFO, ERIC, and Embase. Key search words included residents, residents as teachers, teaching, internship and residency, and curriculum. In addition, a search of MedEdPORTAL was performed using the same key terms. Articles were evaluated based on the reproducibility of curricula and the assessment tools. Evaluation of educational outcomes was performed using the Kirkpatrick model.

Results

Thirty-nine articles were deemed appropriate for review. Interventions and evaluation techniques varied greatly. Only 1 article from the literature was deemed to have both curricula and assessments that would be fully reproducible by other programs.

Conclusions

A literature review on RAT curricula found few articles that would be easily reproduced for residency programs that want to start or improve their own RAT curricula. It also demonstrated the difficulty and lack of rigorous outcome measurements for most curricula.
Ultrasonography and Color Doppler in the Differential Diagnosis of Periapical Cyst and Granuloma
Authors: Arora Vimal , Tiwari Brijesh , Krishnan Manu , Popli Manju , Iyer Satish R
Published: April 2014

Background and objectives

Though ultrasonography and color Doppler are well established diagnostic techniques in medical sciences, it is not so popular in dentistry. Aim of the study was to evaluate the diagnostic value of ultrasonography and color Doppler in periapical cysts and granulomas in the anterior region of the jaws.

Materials and Methods

Thirty patients aged between 30 and 50 years with periapical lesions in anterior teeth were selected and consented for ultrasonography and color Doppler examinations. Shape, boundary, echo intensity, echo pattern, acoustic enhancement and vascularity of the periapical lesions and adjacent tissues were studied. After endodontic filling, lesions were enucleated and histopathology was done. Ultrasonographic/color Doppler findings and histopathology were statistically evaluated with Chi-square tests at p < 0.001. Sensitivity, specificity, positive and negative predictive values and accuracy of the method were then determined.

Results

Noninfected cysts showed as anechoic areas while infected cysts appeared as hypoechoic. Vascular hypoechoic areas proved to be periapical granulomas. Periapical infected and noninfected cysts maintained 100% correlation with histopathology, while periapical granuloma had only 70% relation due to thick overlying cortical bones. It implied an accuracy of 90% for this method with overall positive and negative predictive values of 86.96% and 100% respectively.

Conclusion

The study demonstrated efficacy of USG in combination with color Doppler as a safe, noninvasive option to diagnose solid/cystic periapical lesions. However, it also highlighted the need for further investigations in resolving diagnostic issues of periapical lesions covered with thick cortical bones.

How to cite this article

Tiwari B, Krishnan M, Popli M, Iyer SR, Arora V. Ultrasonography and Color Doppler in the Differential Diagnosis of Periapical Cyst and Granuloma. J Contemp Dent 2014;4(1):17-21.
Dental Hand for Rural Population: Teledentistry
Authors: Jain Ankita , Bhaskar Dara John , Gupta Devanand , Agali Chandan , Mark Ruhi
Published: April 2014

Purpose

To know any alternate method for the provision of dental needs for the rural population.

Introduction

Teledentistry is an upcoming field in dentistry that combines telecommunication technology and dental care. It is an exciting field that has endless potential. Teledentistry increased patient access to dental care, improved quality of care and the cost effectiveness. Teledentistry is also useful in long-distance clinical training and continuing education, screening and dentistlaboratory communication.

Materials and Methods

This review article is formulated based on the available literature online. A thorough search was made on the pubmed and other reliable sources and then this review is formed.

Conclusion

Teledentistry may provide a possible solution to many prevailing problems related to dental care provision, like people living in rural areas and those who are not able to retrieve regular dental care. The future of teledentistry will depend on the efforts of the health authorities as on the collective efforts of the dental professionals. Most of the dentists are unaware about teledentistry, about its goals and advantages and how to get involved into it.

How to cite this article

Jain A, Bhaskar Dj, Gupta D, Agali C, Gupta V, Mark R. Dental Hand for Rural Population: Teledentistry. J Contemp Dent 2014;4(1):27-29.
Interimplant Papilla Reconstruction
Authors: Kanagotagi Sachin , Pathak Tushar Sakal , Gupta Himani Swatantrakumar , Rajguru Sneha Anil , Padhye Ashvini Mukul , Rathod Aditi Ashok
Published: April 2014

Background and objective

Pink gingival esthetics, especially in the anterior teeth, has been an important success criterion in implant-supported restoration. The factor vital to the esthetic success, in the anterior maxillary implants, is the soft tissue profile, which should replicate that of the natural healthy tooth. The absence of the interimplant papilla causes an interimplant black triangle thus leading to cosmetic deformities, phonetic difficulty and food impaction. True papilla regeneration is not possible because the peri-implant soft tissue does not have the same structure as that of the periodontium and, therefore, the term ‘papilla-like’ tissue formation or ‘implant papilla’ is used. This resultant ‘implant papilla’ is the product of soft tissue depth and volume and has to be skilfully surgically created. However, reconstructing a predictable peri-implant papilla is the most complex and challenging aspect of implant dentistry. This article presents a review of various innovative surgical techniques to reconstruct interimplant papilla.

How to cite this article

Rajguru SA, Pathak TS, Padhye AM, Kanagotagi S, Gupta HS, Rathod AA. Interimplant Papilla Reconstruction. J Contemp Dent 2014;4(1):30-40.
Retrieval of Separated Instrument using Ultrasonics in a Permanent Mandibular Second Molar: A Case Report
Authors: Shenoy Vanitha , Sokhi Rithima
Published: April 2014

Clinicians are frequently challenged by endodontically treated teeth that have obstructions, such as hard impenetrable pastes, separated instruments, silver points or posts in their root canals. Intracanal separation of endodontic instruments may hinder cleaning and shaping procedures within the root canal system, with a potential impact on the outcome of treatment. Broken instruments usually prevent access to the apex and the prognosis of teeth with broken instruments in the canals may be lower than for normal ones. The prognosis of these cases mainly depends on the preoperative condition of the periapical tissues. For these reasons, an attempt to remove broken instruments should be undertaken in every case.

Ultrasonics have often been advocated for the removal of broken instruments because the ultrasonic tips or endosonic files may be used deep in the root canal system. Furthermore, the use of an ultrasonic endodontic device is not restricted by the position of the fragment in the root canal or the tooth involved. This case report elaborates on retrieval of broken instrument lodged in the coronal third of the root canal using ultrasonics and dental operating microscope.

How to cite this article

Sokhi R, Sumanthini MV, Shenoy V. Retrieval of Separated Instrument using Ultrasonics in a Permanent Mandibular Second Molar: A Case Report. J Contemp Dent 2014;4(1):41-45.
Analysis of nucleation events in the European boundary layer using the regional aerosol-climate model REMO-HAM with a solar radiation-driven OH-proxy
Authors: Pietikäinen J.-P. , Mikkonen S. , Hamed A. , Hienola A. I. , Birmili W. , Kulmala M. , Laaksonen A.
Published: April 2014

Abstract. This work describes improvements in the regional aerosol-climate model REMO-HAM in order to simulate more realistically the process of atmospheric new particle formation (NPF). As a first modification, a new scheme was implemented to simulate OH radical concentrations, now using a proxy approach based on observations and also accounting for the effects of clouds upon OH concentrations. Second, the nucleation rate calculation was modified to directly simulate the formation rates of 3 nm particles, which removes some unnecessary steps in formation rate calculations used earlier in the model. Using the updated model version, the NPF over Europe was simulated for the comprehensive periods 2003–2004 and 2008–2009. The statistics of the simulated particle formation events were subsequently compared to observations from 13 ground-based measurement sites. The new model shows improved agreement with the observed NPF rates compared to former versions and can simulate the event statistics realistically for most parts of Europe. It is our conclusion that further modifications of the OH proxy that reflect the diverse atmospheric composition across Europe have the potential to further improvements.