bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of different coloured luminous surrounds on LED discomfort glare perception
Authors: Sweater-Hickcox K , Narendran N , Bullough JD , Freyssinier JP
Published: February 2013

Recently, there has been increased interest in energy-efficient lighting as energy resources become higher in demand. Anecdotal evidence suggests that certain populations believe light-emitting diodes (LED) produce more glare than traditional technologies. This may be due to a number of factors such as spectral power distribution (SPD), source luminance, or beam intensity distribution. A study was conducted to assess the effect of different SPDs on the perception of discomfort glare from an LED source. For the range of conditions evaluated, the presence of any luminous surround significantly reduced the perception of discomfort glare from the LED array. The blue luminous surround reduced discomfort glare perception significantly less than the white or the yellow luminous surrounds. The implications for solid-state lighting systems are discussed.
How I treat patients with indolent and smoldering mastocytosis (rare conditions but difficult to manage)
Authors: Pardanani Animesh
Published: February 2013

Indolent systemic mastocytosis (SM) patients have a varied clinical presentation, ranging from predominantly cutaneous symptoms to recurrent systemic symptoms (eg, flushing, palpitations, dyspepsia, diarrhea, bone pain) that can be severe and potentially life threatening (anaphylaxis). Mastocytosis patients without skin involvement pose a diagnostic challenge; a high index of suspicion is needed in those with mast cell–degranulation symptoms, including anaphylaxis following Hymenoptera stings or other triggers. Modern-era molecular and flow-cytometric diagnostic methods are very sensitive and can detect minimal involvement of bone marrow with atypical/clonal mast cells; in some cases, full diagnostic criteria for SM are not fulfilled. An important aspect of treatment is avoidance of known symptom triggers; other treatment principles include a stepwise escalation of antimediator therapies and consideration of cytoreductive therapies for those with treatment-refractory symptoms. The perioperative management of mastocytosis patients is nontrivial; a multidisciplinary preoperative assessment, adequate premedications, and close intra- and postoperative monitoring are critical. Smoldering mastocytosis is a variant with high systemic mast cell burden. While its clinical course can be variable, there is greater potential need for cytoreductive therapies (eg, interferon-alpha, cladribine) in this setting. A systematic approach to the diagnosis and treatment of indolent SM using a case-based approach of representative clinical scenarios is presented here.
Genome sequence-based species delimitation with confidence intervals and improved distance functions
Authors: Meier-Kolthoff Jan P , Auch Alexander F , Klenk Hans-Peter , Göker Markus
Published: February 2013

Background

For the last 25 years species delimitation in prokaryotes (ArchaeaandBacteria) was to a large extent based on DNA-DNA hybridization (DDH), a tedious lab procedure designed in the early 1970s that served its purpose astonishingly well in the absence of deciphered genome sequences. With the rapid progress in genome sequencing time has come to directly use the now available and easy to generate genome sequences for delimitation of species. (Genome Blast Distance Phylogeny) infers genome-to-genome distances between pairs of entirely or partially sequenced genomes, a digital, highly reliable estimator for the relatedness of genomes. Its application as an in-silico replacement for DDH was recently introduced. The main challenge in the implementation of such an application is to produce digital DDH values that must mimic the wet-lab DDH values as close as possible to ensure consistency in the Prokaryotic species concept.

Results

Correlation and regression analyses were used to determine the best-performing methods and the most influential parameters. was further enriched with a set of new features such as confidence intervals for intergenomic distances obtained via resampling or via the statistical models for DDH prediction and an additional family of distance functions. As in previous analyses, obtained the highest agreement with wet-lab DDH among all tested methods, but improved models led to a further increase in the accuracy of DDH prediction. Confidence intervals yielded stable results when inferred from the statistical models, whereas those obtained via resampling showed marked differences between the underlying distance functions.

Conclusions

Despite the high accuracy of -based DDH prediction, inferences from limited empirical data are always associated with a certain degree of uncertainty. It is thus crucial to enrich in-silico DDH replacements with confidence-interval estimation, enabling the user to statistically evaluate the outcomes. Such methodological advancements, easily accessible through the web service athttp://ggdc.dsmz.de, are crucial steps towards a consistent and truly genome sequence-based classification of microorganisms.
Are family practice trainers and their host practices any better? comparing practice trainers and non-trainers and their practices
Authors: van den Hombergh Pieter , Schalk-Soekar Saskia , Kramer Anneke , Bottema Ben , Campbell Stephen , Braspenning Jozé
Published: February 2013

Background

Family Physician (FP) trainees are expected to be provided with high quality training in well organized practice settings. This study examines differences between FP trainers and non-trainers and their practices to see whether there are differences in trainers and non-trainers and in how their practices are organized and their services are delivered.

Method

203 practices (88 non-training and 115 training) with 512 FPs (335 non-trainers and 177 trainers) were assessed using the “Visit Instrument Practice organization (VIP)” on 369 items (142 FP-level; 227 Practice level). Analyses (ANOVA, ANCOVA) were conducted for each level by calculating differences between FP trainees and non-trainees and their host practices.

Results

Trainers scored higher on all but one of the items, and significantly higher on 47 items, of which 13 remained significant after correcting for covariates. Training practices scored higher on all items and significantly higher on 61 items, of which 23 remained significant after correcting for covariates. Trainers (and training practices) provided more diagnostic and therapeutic services, made better use of team skills and scored higher on practice organization, chronic care services and quality management than non-training practices. Trainers reported more job satisfaction and commitment and less job stress than non-trainers.

Discussion

There are positive differences between FP trainers and non-trainers in both the level and the quality of services provided by their host practices. Training institutions can use this information to promote the advantages of becoming a FP trainer and training practice as well as to improve the quality of training settings for FPs.
Neurogenesis in zebrafish – from embryo to adult
Authors: Schmidt Rebecca , Strähle Uwe , Scholpp Steffen
Published: February 2013

Neurogenesis in the developing central nervous system consists of the induction and proliferation of neural progenitor cells and their subsequent differentiation into mature neurons. External as well as internal cues orchestrate neurogenesis in a precise temporal and spatial way. In the last 20 years, the zebrafish has proven to be an excellent model organism to study neurogenesis in the embryo. Recently, this vertebrate has also become a model for the investigation of adult neurogenesis and neural regeneration. Here, we summarize the contributions of zebrafish in neural development and adult neurogenesis.
Gedruckte Filmbatterien
Authors: Hübner Gunter , Krebs Martin
Published: February 2013

Die Siebdrucktechnologie erlaubt es, Stromableiter-, Elektroden- und Separator/Elektrolyt-Materialien in mehreren Schichten auf ein Foliensubstrat übereinander zu drucken und damit eine flache, flexible Filmbatterie in Einzel- oder Multizellen-Reihenschaltung aufzubauen. Zum ersten Mal werden gedruckte, wieder aufladbare Ni-MH-Zellen realisiert, die eine Kapazität von ca. 32 mAh aufweisen bei einer aktiven Fläche von 20×20 mm2 und einer Gesamtdicke von rund 0,6 mm. Die Verkapselungsproblematik konnte mit Hilfe thermisch aktivierbarer, verdruckbarer Siegelschichten gelöst werden. In Langzeit-Zyklisierungen wurde die Langzeitstabilität der Zellen geprüft. Ein druckbarer Elektrolyt/Separator wurde entwickelt.
The pathogenesis of non-alcoholic fatty liver disease is closely related to the metabolic syndrome components
Authors: Hurjui Daniela Maria , Niţă Otilia , Graur Lidia Iuliana , Popescu Dana Ştefana , Mihalache Laura , Huţanaşu Cătălin Ilie , Graur Mariana
Published: February 2013

Non-alcoholic fatty liver disease (NAFLD) is closely associated with all features ofthe metabolic syndrome (MS). This strongly supports the notion that NAFLD may bethe hepatic manifestation of the MS. NAFLD is currently the most common cause ofabnormal liver function tests and affects approximatively 15-25% of the generalpopulation. NAFLD covers a spectrum of liver disease, from steatosis to nonalcoholicsteatohepatitis (NASH) and cirrhosis. Insulin resistance (IR) has centraletiologic roles in the development of MS and NAFLD, usually related to obesity. MSis frequently associated with chronic inflammation, having as principal mediatorsthe adipocytokines and free fatty acids (FFA), but also CRP, TNF-a and IL-6.Chronic inflammation results in more IR and lipolysis of adipose tissue triglyceridestores, in enhanced hepatic glucose and VLDL production. The steatotic liver isthought to be vulnerable to secondary injuries including adipocytokines,mitochondrial dysfunctions, oxidative stress which lead to hepatocellularinflammation and fibrosis.
Immediate Effects of Region-Specific and Non–Region-Specific Spinal Manipulative Therapy in Patients With Chronic Low Back Pain: A Randomized Controlled Trial
Authors: de Oliveira Ronaldo Fernando , Liebano Richard Eloin , Costa Lucíola da Cunha Menezes , Rissato Lívia Leticia , Costa Leonardo Oliveira Pena
Published: February 2013

Background

Manual therapists typically advocate the need for a detailed clinical examination to decide which vertebral level should be manipulated in patients with low back pain. However, it is unclear whether spinal manipulation needs to be specific to a vertebral level.

Objective

The purpose of this study was to analyze the immediate effects of a single, region-specific spinal manipulation defined during the clinical examination versus a single non–region-specific spinal manipulation (applied on an upper thoracic vertebra) in patients with chronic nonspecific low back pain for the outcome measures of pain intensity and pressure pain threshold at the time of the assessment.

Design

This was a 2-arm, prospectively registered, randomized controlled trial with a blinded assessor.

Setting

The study was conducted in an outpatient physical therapy clinic in Brazil.

Patients

The study participants were 148 patients with chronic nonspecific low back pain (with pain duration of at least 12 weeks).

Randomization

The randomization schedule was generated by an independent statistician and was concealed by using consecutively numbered, sealed, opaque envelopes.

Interventions

A single high-velocity manipulation was administered to the upper thoracic region of the participants allocated to the non–region-specific manipulation group and to the painful lumbar levels of the participants allocated to the region-specific manipulation group.

Measurements

Pain intensity was measured by a 0 to 10 numeric pain rating scale. Pressure pain threshold was measured using a pressure algometer.

Limitations

It was not possible to blind the therapist and participants.

Results

A total of 148 patients participated in the study (74 in each group). There was no loss to follow-up. Both groups improved in terms of immediate decrease of pain intensity; however, no between-group differences were observed. The between-group difference for pain intensity and pressure pain threshold were 0.50 points (95% confidence interval=−0.10 to 1.10) and −1.78 points (95% confidence interval=−6.40 to 2.82), respectively. No adverse reactions were observed.

Conclusion

The immediate changes in pain intensity and pressure pain threshold after a single high-velocity manipulation do not differ by region-specific versus non–region-specific manipulation techniques in patients with chronic low back pain.
Lipid Nanotechnology
Authors: Mashaghi Samaneh , Jadidi Tayebeh , Koenderink Gijsje , Mashaghi Alireza
Published: February 2013

Nanotechnology is a multidisciplinary field that covers a vast and diverse array of devices and machines derived from engineering, physics, materials science, chemistry and biology. These devices have found applications in biomedical sciences, such as targeted drug delivery, bio-imaging, sensing and diagnosis of pathologies at early stages. In these applications, nano-devices typically interface with the plasma membrane of cells. On the other hand, naturally occurring nanostructures in biology have been a source of inspiration for new nanotechnological designs and hybrid nanostructures made of biological and non-biological, organic and inorganic building blocks. Lipids, with their amphiphilicity, diversity of head and tail chemistry, and antifouling properties that block nonspecific binding to lipid-coated surfaces, provide a powerful toolbox for nanotechnology. This review discusses the progress in the emerging field of lipid nanotechnology.
Enteral and Parenteral Nutrition in the Perioperative Period: State of the Art
Authors: Abunnaja Salim , Cuviello Andrea , Sanchez Juan
Published: February 2013

Nutritional support of surgical and critically ill patients has undergone significant advances since 1936 when Studley demonstrated a direct relationship between pre-operative weight loss and operative mortality. The advent of total parenteral nutrition followed by the extraordinary progress in parenteral and enteral feedings, in addition to the increased knowledge of cellular biology and biochemistry, have allowed clinicians to treat malnutrition and improve surgical patient’s outcomes. We reviewed the literature for the current status of perioperative nutrition comparing parenteral nutrition with enteral nutrition. In a surgical patient with established malnutrition, nutritional support should begin at least 7–10 days prior to surgery. Those patients in whom eating is not anticipated beyond the first five days following surgery should receive the benefits of early enteral or parenteral feeding depending on whether the gut can be used. Compared to parenteral nutrition, enteral nutrition is associated with fewer complications, a decrease in the length of hospital stay, and a favorable cost-benefit analysis. In addition, many patients may benefit from newer enteral formulations such as Immunonutrition as well as disease-specific formulations.
A Neuro-Fuzzy System for Characterization of Arm Movements
Authors: Balbinot Alexandre , Favieiro Gabriela
Published: February 2013

The myoelectric signal reflects the electrical activity of skeletal muscles and contains information about the structure and function of the muscles which make different parts of the body move. Advances in engineering have extended electromyography beyond the traditional diagnostic applications to also include applications in diverse areas such as rehabilitation, movement analysis and myoelectric control of prosthesis. This paper aims to study and develop a system that uses myoelectric signals, acquired by surface electrodes, to characterize certain movements of the human arm. To recognize certain hand-arm segment movements, was developed an algorithm for pattern recognition technique based on neuro-fuzzy, representing the core of this research. This algorithm has as input the preprocessed myoelectric signal, to disclosed specific characteristics of the signal, and as output the performed movement. The average accuracy obtained was 86% to 7 distinct movements in tests of long duration (about three hours).
Management of Lens Dislocation and Iris Cyst After Iris Sutured Intraocular Lens Implantation in Children With Marfan Syndrome
Authors: Salchow Daniel J. , Sinard John
Published: February 2013

The authors describe two brothers with Marfan syndrome who developed severe complications after iris-suture fixation of an intraocular lens (IOL). A secondary iris cyst developed in one and the IOL dislocated into the vitreous in the other, requiring pars plana vitrectomy and IOL removal. Although the visual outcome was good in both cases, severe complications of iris-suture fixated IOLs must be considered when surgical correction of aphakia is attempted in children with Marfan syndrome.
A Logic-Based Approach to Activity Recognition
Authors: Artikis Alexander , Sergot Marek , Paliouras Georgios
Published: February 2013

The authors have been developing a system for recognising human activities given a symbolic representation of video content. The input of the system is a stream of time-stamped short-term activities detected on video frames. The output of the system is a set of recognised long-term activities, which are pre-defined spatio-temporal combinations of short-term activities. The constraints on the short-term activities that, if satisfied, lead to the recognition of a long-term activity, are expressed using a dialect of the Event Calculus. The authors illustrate the expressiveness of the dialect by showing the representation of several typical complex activities. Furthermore, they present a detailed evaluation of the system through experimentation on a benchmark dataset of surveillance videos.
Monitoring Social Life and Interactions
Authors: Odella Francesca
Published: February 2013

The chapter describes the sociological perspective of monitoring technologies and debates its method for analysing social implications of scientific and technical developments. It is articulated in five sections dedicated to social and privacy aspects involved in social analysis of technologies. Particular attention is devoted to social network analysis, an emergent area of sociological research that focuses on the relational implications of technologies in organizations, small groups, and other contexts of social participation. The text integrates examples of technology implementation from healthcare automated assistance to mobile communication devices, video-surveillance, RFID, and smart-meter technology. Case studies, illustrated in separate textboxes, describe the advancements in this field of enquiry and highlight the main elements of the structure of interactions in virtual and technology-mediated communications. Finally, ethical implications of behaviour monitoring technologies are discussed together with recent perspectives of sociological research.
Tuning Innate Immune Activation by Surface Texturing of Polymer Microparticles: The Role of Shape in Inflammasome Activation
Authors: Vaine Christine A. , Patel Milan K. , Zhu Jintao , Lee Eunji , Finberg Robert W. , Hayward Ryan C. , Kurt-Jones Evelyn A.
Published: February 2013

Polymeric microparticles have been widely investigated as platforms for delivery of drugs, vaccines, and imaging contrast agents and are increasingly used in a variety of clinical applications. Microparticles activate the inflammasome complex and induce the processing and secretion of IL-1β, a key innate immune cytokine. Recent work suggests that although receptors are clearly important for particle phagocytosis, other physical characteristics, especially shape, play an important role in the way microparticles activate cells. We examined the role of particle surface texturing not only on uptake efficiency but also on the subsequent immune cell activation of the inflammasome. Using a method based on emulsion processing of amphiphilic block copolymers, we prepared microparticles with similar overall sizes and surface chemistries but having either smooth or highly microtextured surfaces. In vivo, textured (budding) particles induced more rapid neutrophil recruitment to the injection site. In vitro, budding particles were more readily phagocytosed than smooth particles and induced more lipid raft recruitment to the phagosome. Remarkably, budding particles also induced stronger IL-1β secretion than smooth particles through activation of the NLRP3 inflammasome. These findings demonstrate a pronounced role of particle surface topography in immune cell activation, suggesting that shape is a major determinant of inflammasome activation.
A Dynamic Dual Role of IL-2 Signaling in the Two-Step Differentiation Process of Adaptive Regulatory T Cells
Authors: Guo Zhiyong , Khattar Mithun , Schroder Paul M. , Miyahara Yoshihiro , Wang Guohua , He Xiaoshung , Chen Wenhao , Stepkowski Stanislaw M.
Published: February 2013

The molecular mechanism of the extrathymic generation of adaptive, or inducible, CD4+Foxp3+ regulatory T cells (iTregs) remains incompletely defined. We show that exposure of splenic CD4+CD25+Foxp3− cells to IL-2, but not other common γ-chain cytokines, resulted in Stat5 phosphorylation and induced Foxp3 expression in ∼10% of the cells. Thus, IL-2/Stat5 signaling may be critical for Foxp3 induction in peripheral CD4+CD25+Foxp3– iTreg precursors. In this study, to further define the role of IL-2 in the formation of iTreg precursors as well as their subsequent Foxp3 expression, we designed a two-step iTreg differentiation model. During the initial “conditioning” step, CD4+CD25−Foxp3− naive T cells were activated by TCR stimulation. Inhibition of IL-2 signaling via Jak3–Stat5 was required during this step to generate CD4+CD25+Foxp3− cells containing iTreg precursors. During the subsequent Foxp3-induction step driven by cytokines, IL-2 was the most potent cytokine to induce Foxp3 expression in these iTreg precursors. This two-step method generated a large number of iTregs with relatively stable expression of Foxp3, which were able to prevent CD4+CD45RBhigh cell–mediated colitis in Rag1−/− mice. In consideration of this information, whereas initial inhibition of IL-2 signaling upon T cell priming generates iTreg precursors, subsequent activation of IL-2 signaling in these precursors induces the expression of Foxp3. These findings advance the understanding of iTreg differentiation and may facilitate the therapeutic use of iTregs in immune disorders.
Requirement for Dicer in Survival of Proliferating Thymocytes Experiencing DNA Double-Strand Breaks
Authors: Brady Brenna L. , Rupp Levi J. , Bassing Craig H.
Published: February 2013

The Dicer nuclease generates small RNAs that regulate diverse biological processes through posttranscriptional gene repression and epigenetic silencing of transcription and recombination. Dicer-deficient cells exhibit impaired differentiation, activity, proliferation, and survival. Dicer inactivation in developing mouse lymphocytes impairs their proliferation and survival and alters Ag receptor gene repertoires for largely undefined reasons. To elucidate functions of Dicer in lymphocyte development and Ag receptor locus transcription and recombination, we analyzed mice with conditional Dicer deletion in thymocytes containing unrearranged or prerearranged TCRβ loci. Expression of either a preassembled functional TCRβ gene (Vβ1NT) or the prosurvival BCL2 protein inhibited death and partially rescued proliferative expansion of Dicer-deficient thymocytes. Notably, combined expression of Vβ1NT and BCL2 completely rescued proliferative expansion of Dicer-deficient thymocytes and revealed that Dicer promotes survival of cells attempting TCRβ recombination. Finally, inclusion of an endogenous preassembled DJβ complex that enhances Vβ recombination increased death and impaired proliferative expansion of Dicer-deficient thymocytes. These data demonstrate a critical role for Dicer in promoting survival of thymocytes experiencing DNA double-strand breaks (DSBs) during TCRβ recombination. Because DSBs are common and ubiquitous in cells, our findings indicate that impaired cellular survival in response to DSBs should be considered when interpreting Dicer-deficient phenotypes.
Gene Deletion of Gabarap Enhances Nlrp3 Inflammasome-Dependent Inflammatory Responses
Authors: Zhang Zhirong , Xu Xiaozheng , Ma Jianhui , Wu Jianfeng , Wang Yanhai , Zhou Rongbin , Han Jiahuai
Published: February 2013

The γ-aminobutyric acid A receptor–associated protein (Gabarap) functions in γ-aminobutyric acid A receptor trafficking and postsynaptic localization in neurons, but its physiological roles in other systems have not been studied. In this study, we report that Gabarap-deficient mice are more susceptible to mortality in two sepsis models. An underlying mechanism of this higher mortality rate in Gabarap−/− septic mice is the higher level of proinflammatory cytokine expression in Gabarap−/− mice versus wild-type mice. In vitro studies show that Nlrp3 inflammasome activation is enhanced by Gabarap deficiency, as evidenced by more casapse-1 activation, more IL-1β, and more IL-18 secretion in LPS- and ATP-treated Gabarap−/− macrophages. The Gabarap deficiency led to inefficient clearance of damaged mitochondria in LPS plus ATP–treated macrophages, resulting in more mitochondrial ROS and the release of mitochondrial DNA into cytosol. Both ROS and mitochondrial DNA are known to promote inflammasome activation. These results demonstrate that Gabarap functions in the immune system. It is involved in mitochondrial quality control in macrophages, and thus it influences Nlrp3 inflammasome-dependent inflammatory responses.
Cytoplasmic Overexpression of HER2: A Key Factor in Colorectal Cancer
Authors: Blok Erik J , Kuppen Peter JK , van Leeuwen Jeroen EM , Sier Cornelis FM
Published: February 2013

Trastuzumab, a humanized mouse monoclonal antibody directed against HER2 (Human Epidermal Growth Factor Receptor 2), is currently a keystone in the treatment of breast cancer. Meanwhile, trastuzumab has been validated for use in other types of cancer too. But the data on HER2 expression in colorectal cancer are ambiguous, with reported overexpression of HER2 varying between zero and 84%. In this review these studies are evaluated and compared. It shows that many factors influence the determination of HER2-expression, especially of the intracellular fraction of HER2. It is concluded that although membranous overexpression of HER2 is low in colorectal cancer with only 5% of all patients being positive, a significant proportion of the patients (30%) shows cytoplasmic HER2 overexpression. The clinical impact of enhanced intracellular HER2 is not known, because the nature and origin have not completely been revealed yet. Enlightening this process could be a stepping stone towards targeting of intracellular HER2 as a treatment option.
Regio- and Chemoselective Synthesis of 5-Aroyl-NH-1,3-oxazolidine-2- thiones
Authors: Sadegh-Malvajerd Soroor , Arzehgar Zeinab , Nikpour Farzad
Published: February 2013

A one-pot synthesis of 5-aroyl-NH-1,3-oxazolidine-2-thiones by a regio- and chemoselective reaction of α-epoxyketones with thiourea or sodium thiocyanate in the presence of p-toluenesulfonic acid as catalyst in tetra-n-butylammonium chloride is described.
Expérience de résolution de problèmes par une démarche créative dans la formation des enseignants en adaptation scolaire
Authors: Ouellet Sylvie
Published: February 2013

Cet article aborde la formation des enseignants en adaptation scolaire, à partir d’une expérience vécue dans le cours Résolution de problèmes et créativité. La difficile situation de l’insertion professionnelle met en évidence l’importance de préparer les futurs enseignants à être des intervenants créatifs afin de relever les défis de l’école contemporaine. Différents concepts sont présentés : la créativité, la pédagogie créative, l’enseignant créatif et, enfin, la pratique réflexive à partir d’une démarche de création. Le développement de la créativité, utilisant un espace de création et de réflexion chez les futurs enseignants, est exploré dans cette expérience d’apprentissage. La démarche créative est appuyée par des exercices artistiques stimulant la créativité, complétée par l’introduction à la recherche-action et à la résolution créative de problèmes. Le processus d’apprentissage des étudiants est illustré par deux exemples, un exercice et ses artéfacts (le masque), ainsi que par l’autoévaluation soutenue par la réalisation d’un carnet de dessins. Cet outil incite à prendre du recul pour exercer sa pratique réflexive. Les commentaires des étudiants précisent les effets de ces deux démarches, une meilleure réflexion sur la pratique et une prise de conscience de l’identité professionnelle en construction. La discussion vient alimenter une réflexion sur la créativité en milieu scolaire. La conclusion, enfin, formule des recommandations pour la formation des enseignants, entre autres celle de la concertation pour développer la créativité chez les enseignants.
Quantitating intraparticle O2 gradients in solid supported enzyme immobilizates: Experimental determination of their role in limiting the catalytic effectiveness of immobilized glucose oxidase
Authors: Bolivar Juan M. , Consolati Tanja , Mayr Torsten , Nidetzky Bernd
Published: February 2013

Enzymatic O2‐dependent oxidations are receiving increased attention for use in fine chemicals synthesis. Solid supported oxidation catalysts often show poor efficiency due to pronounced O2 diffusion restriction. Internal O2 supply therefore constitutes a key parameter for optimizing the enzyme immobilization. We herein describe an optical sensing method for quantitation of space‐averaged intraparticle O2 concentrations in porous Sepabeads carriers. The method applies phosphorescence lifetime measurements on Sepabeads labeled with an O2 sensitive indicator dye. Using glucose oxidase immobilized at different loadings (0.005–12 mg/g) on labeled Sepabeads, we analyzed in real time during the enzymatic reaction the formation of O2 concentration differences between bulk liquid and the intraparticle environment. We show that the O2 gradient at apparent steady state increased with increasing enzyme loading, so that O2 eventually became totally depleted from inside the highly loaded carriers. We also show that the residual intraparticle O2 concentration was correlated with the catalytic effectiveness factor (η) of the enzyme immobilizate used, thus providing a direct measure of the magnitude of O2 diffusion limitation. Once corrected for diffusional effect, η was no longer dependent on enzyme loading and its constant value now described the intrinsic activity of immobilized glucose oxidase. Three common procedures of enzyme immobilization, involving adsorption, cross‐linking, and covalent attachment, are shown to differ widely concerning the obtained intrinsic activity. Therefore, intraparticle O2 concentration data enable distinction between diffusional restriction and activity loss as the two principal factors limiting the effectiveness of immobilized O2 dependent enzymes, and thus they inform rational design of an optimally active oxidation biocatalyst on solid support. Biotechnol. Bioeng. 2013; 110: 2086–2095. © 2013 Wiley Periodicals, Inc.
Indications for and efficacy of splenectomy for haematological disorders
Authors: Bickenbach K A , Gonen M , Labow D M , Strong V , Heaney M L , Zelenetz A D , Coit D G
Published: February 2013

Background

Splenectomy is performed for a variety of indications in haematological disorders. This study was undertaken to analyse outcomes, and morbidity and mortality rates associated with this procedure.

Methods

Patients undergoing splenectomy for the treatment or diagnosis of haematological disease were included. Indications for operation, preoperative risk, intraoperative variables and short-term outcomes were evaluated.

Results

From January 1997 to December 2010, 381 patients underwent splenectomy for diagnosis or treatment of haematological disease. Some 288 operations were performed by an open approach, 83 laparoscopically, and there were ten conversions. Overall 136 patients (35·7 per cent) experienced complications. Postoperative morbidity was predicted by age more than 65 years (odds ratio (OR) 1·63, 95 per cent confidence interval 1·05 to 2·55), a Karnofsky performance status (KPS) score lower than 60 (OR 2·74, 1·35 to 5·57) and a haemoglobin level of 9 g/dl or less (OR 1·74, 1·09 to 2·77). Twenty-four patients (6·3 per cent) died within 30 days of surgery. Postoperative mortality was predicted by a KPS score lower than 60 (OR 16·20, 6·10 to 42·92) and a platelet count of 50 000/µl or less (OR 3·34, 1·25 to 8·86). The objective of the operation was achieved in 309 patients (81·1 per cent). The success rate varied for each indication: diagnosis (106 of 110 patients, 96·4 per cent), thrombocytopenia (76 of 115, 66·1 per cent), anaemia (10 of 16, 63 per cent), to allow further treatment (46 of 59, 78 per cent) and primary treatment (16 of 18, 89 per cent).

Conclusion

Splenectomy is an effective procedure in the diagnosis and treatment of haematological disease in selected patients.
Sex differences in life history drive evolutionary transitions among maternal, paternal, and bi‐parental care
Authors: Klug Hope , Bonsall Michael B. , Alonzo Suzanne H.
Published: February 2013

Evolutionary transitions among maternal, paternal, and bi‐parental care have been common in many animal groups. We use a mathematical model to examine the effect of male and female life‐history characteristics (stage‐specific maturation and mortality) on evolutionary transitions among maternal, paternal, and bi‐parental care. When males and females are relatively similar – that is, when females initially invest relatively little into eggs and both sexes have similar mortality and maturation – transitions among different patterns of care are unlikely to be strongly favored. As males and females become more different, transitions are more likely. If females initially invest heavily into eggs and this reduces their expected future reproductive success, transitions to increased maternal care (paternal → maternal, paternal → bi‐parental, bi‐parental → maternal) are favored. This effect of anisogamy (i.e., the fact that females initially invest more into each individual zygote than males) might help explain the predominance of maternal care in nature and differs from previous work that found no effect of anisogamy on the origin of different sex‐specific patterns of care from an ancestral state of no care. When male mortality is high or male egg maturation rate is low, males have reduced future reproductive potential and transitions to increased paternal care (maternal → paternal, bi‐parental → paternal, maternal → bi‐parental) are favored. Offspring need (i.e., low offspring survival in the absence of care) also plays a role in transitions to paternal care. In general, basic life‐history differences between the sexes can drive evolutionary transitions among different sex‐specific patterns of care. The finding that simple life‐history differences can alone lead to transitions among maternal and paternal care suggests that the effect of inter‐sexual life‐history differences should be considered as a baseline scenario when attempting to understand how other factors (mate availability, sex differences in the costs of competing for mates) influence the evolution of parental care.
Convenient Access to Acyl‐Substituted Bis(styrylbenzenes) Based on Building Blocks Using Julia Olefination and Weinreb Amide Chemistry
Authors: Mukkamala Ramesh , Senthilmurugan Annamalai , Aidhen Indrapal Singh
Published: February 2013

In an effort to arrive at bis(styrylbenzene) derivatives, which are known for their importance in connection to Alzheimer's disease, two bifunctional building blocks that enable a C–C bond formation through a Julia–Kocienski reaction were synthesized. The orthogonal nature of the two functional groups in these building blocks allow the sequential olefination of commercially available aromatic aldehydes and the intermediate stilbene aldehydes to deliver an efficient and new route for bis(styrylbenzenes) with Weinreb amide (WA) functionality for the first time. The successful incorporation of the WA functionality has facilitated convenient access to unknown bis(styrylbenzenes) with acyl and formyl groups as substituents This strategy has also paved the way for highly functionalized bis(styrylbenzenes) with a tetrafluorophenyl core, which have potential as new contrast agents for MRI applications.
Analyses of the impact of climate change on water resources components, drought and wheat yield in semiarid regions: Karkheh River Basin in Iran
Authors: Ashraf Vaghefi S. , Mousavi S. J. , Abbaspour K. C. , Srinivasan R. , Yang H.
Published: February 2013

Water resources availability in the semiarid regions of Iran has experienced severe reduction because of increasing water use and lengthening of dry periods. To better manage this resource, we investigated the impact of climate change on water resources and wheat yield in the Karkheh River Basin (KRB) in the semiarid region of Iran. Future climate scenarios for 2020–2040 were generated from the Canadian Global Coupled Model for scenarios A1B, B1 and A2. We constructed a hydrological model of KRB using the Soil and Water Assessment Tool to project water resources availability. Blue and green water components were modeled with uncertainty ranges for both historic and future data. The Sequential Uncertainty Fitting Version 2 was used with parallel processing option to calibrate the model based on river discharge and wheat yield. Furthermore, a newly developed program called critical continuous day calculator was used to determine the frequency and length of critical periods for precipitation, maximum temperature and soil moisture. We found that in the northern part of KRB, freshwater availability will increase from 1716 to 2670 m3/capita/year despite an increase of 28% in the population in 2025 in the B1 scenario. In the southern part, where much of the agricultural lands are located, the freshwater availability will on the average decrease by 44%. The long‐term average irrigated wheat yield, however, will increase in the south by 1.2%–21% in different subbasins; but for rain‐fed wheat, this variation is from −4% to 38%. The results of critical continuous day calculator showed an increase of up to 25% in both frequency and length of dry periods in south Karkheh, whereas increasing flood events could be expected in the northern and western parts of the region. In general, there is variability in the impact of climate change in the region where some areas will experience net negative whereas other areas will experience a net positive impact. Copyright © 2013 John Wiley & Sons, Ltd.
Advances in fluorescence diagnosis to track footprints of cancer progression in vivo
Authors: Olivo Malini , Ho Chris Jun Hui , Fu Chit Yaw
Published: February 2013

Fluorescence spectroscopy and imaging have been widely used for in vivo cancer diagnosis and therapy monitoring in preclinical models, as well as clinical translation. Great attempts have been made to develop novel fluorescence techniques and improve on existing ones, which can now be used in conjunction with newly developed fluorescent probes for specific cancer imaging. In this review, a broad overview of fluorescence techniques is provided, including photodynamic diagnosis, laser confocal endomicroscopy and fluorescence lifetime imaging, coupled with endogenous and exogenous fluorophores. In particular, endogenous fluorophores, such as nicotinamide adenine dinucleotide (NADH) and flavin adenine dinucleotide (FAD), are highlighted as they are linked to cellular metabolism in precancer growth. The use of near‐infrared dyes, such as indocynanine green (ICG), for imaging deep‐tissue regions is also reviewed. In addition, diagnostic algorithms used for tissue classification and cancer detection will be discussed. Lastly, emerging technologies in fluorescence diagnosis will also be included.
Observations on the melt memory of high negative birefringence spherulites in polypropylene
Authors: Oliveira M. Jovita , Hemsley Derek A.
Published: February 2013

Previously reported work showed that high negative birefringence Type III polypropylene spherulites can occur in the weld zone of butt‐welded injection mouldings. Their occurrence under conditions not normally associated with their formation has been investigated further using a variety of thermal treatments. The behaviour proves to be complex but clear evidence emerges that β‐form nuclei remain active in the material for thermal treatments up to 200°C, although this is time dependent and the number of Type III spherulites steadily reduces.
Enhanced Field‐Emission Behavior of Layered MoS2 Sheets
Authors: Kashid Ranjit V. , Late Dattatray J. , Chou Stanley S. , Huang Yi‐Kai , De Mrinmoy , Joag Dilip S. , More Mahendra A. , Dravid Vinayak P.
Published: February 2013

Field emission studies are reported for the first time on layered MoS2 sheets at the base pressure of ∼1 × 10−8 mbar. The turn‐on field required to draw a field emission current density of 10 μA/cm2 is found to be 3.5 V/μm for MoS2 sheets. The turn‐on values are found to be significantly lower than the reported MoS2 nanoflowers, graphene, and carbon nanotube‐based field emitters due to the high field enhancement factor (∼1138) associated with nanometric sharp edges of MoS2 sheet emitter surface. The emission current–time plots show good stability over a period of 3 h. Owing to the low turn‐on field and planar (sheetlike) structure, the MoS2 could be utilized for future vacuum microelectronics/nanoelectronic and flat panel display applications.
Novel Stannylenes Stabilized with Diethylenetriamido and ­Related Amido Ligands: Synthesis, Structure, and Chemical Properties
Authors: Huang Mengmeng , Kireenko Marina M. , Lermontova El'mira Kh. , Churakov Andrei V. , Oprunenko Yuri F. , Zaitsev Kirill V. , Sorokin Denis , Harms Klaus , Sundermeyer Jörg , Zaitseva Galina S. , Karlov Sergey S.
Published: February 2013

Complexes of divalent tin 7–12 with diethylenetriamines 1–3 and related ligands 4–6 were prepared from Lappert's stannylene, Sn[N(SiMe3)2]2, and the corresponding ligands. Reactivity of the stannylenes in insertion, oxidation and [1+4] cycloaddition reactions were studied. Composition and structures of the products were confirmed by elemental analyses and multinuclear (1H, 13C, 19F, and 119Sn) NMR spectroscopy. Crystal structures of the diethylenetriamines 1, 2, stannylenes 7, 8 and the product of the reaction of stannylene 8 with an azide, which contains an eight‐membered (SnNPO)2 ring, were determined by X‐ray diffraction study.
Using Internet Behavior to Deliver Relevant Television Commercials
Authors: Bellman Steven , Murphy Jamie , Treleaven-Hassard Shiree , O'Farrell James , Qiu Lili , Varan Duane
Published: February 2013

Consumer footprints left on the Internet help advertisers show consumers relevant Web ads, which increase awareness and click-throughs. This “proof of concept” experiment illustrates how Internet behavior can identify relevant television commercials that increase ad-effectiveness by raising attention and ad exposure. Product involvement and prior brand exposure, however, complicate effective Internet-targeting. Ad relevance matters more for low-involvement products, which have a short pre-purchase search process. For the same reason, using Web browsing behavior to make inferences about current ad relevance is more accurate for low-involvement products. Prior brand exposure reduces information-value, even for relevant commercials, and therefore dampens ad relevance's effect on attention and ad exposure.
Measuring Arterial Oxygenation in a High Altitude Field Environment: Comparing Portable Pulse Oximetry With Blood Gas Analysis
Authors: Ross Elliot M. , Matteucci Michael J. , Shepherd Matthew , Barker Matthew , Orr Lance
Published: February 2013

Objective

High altitude environments present unique medical treatment challenges. Medical providers often use small portable pulse oximetry devices to help guide their clinical decision making. A significant body of high altitude research is based on the use of these devices to monitor hypoxia, yet there is a paucity of evidence that these devices are accurate in these environments. We studied whether these devices perform accurately and reliably under true mountain conditions.

Methods

Healthy unacclimatized active-duty military volunteers participating in mountain warfare training at 2100 m (6900 feet) above sea level were evaluated with several different pulse oximetry devices while in a cold weather, high altitude field environment and then had arterial blood gases (ABG) drawn using an i-STAT for comparison. The pulse oximeter readings were compared with the gold standard ABG readings.

Results

A total of 49 individuals completed the study. There was no statistically significant difference between any of the devices and the gold standard of ABG. The best performing device was the PalmSAT (PS) 8000SM finger probe with a mean difference of 2.17% and SD of 2.56 (95% CI, 1.42% to 2.92%). In decreasing order of performance were the PS 8000AA finger probe (mean ± SD, 2.54% ± 2.68%; 95% CI, 1.76% to 3.32%), the PS 8000Q ear probe (2.47% ± 4.36%; 95% CI, 1.21% to 3.75%), the Nonin Onyx 9500 (3.29% ± 3.12%; 95% CI, 2.39% to 4.20%), and finally the PS 8000R forehead reflectance sensor (5.15% ± 2.97%; 95% CI, 4.28% to 6.01%).

Conclusions

Based on the results of this study, results of the newer portable pulse oximeters appear to be closely correlated to that of the ABG measurements when tested in true mountain conditions.
Nonlinear wave propagation of large amplitude ion-acoustic solitary waves in negative ion plasmas with superthermal electrons
Authors: EL-LABANY S. K. , SABRY R. , EL-SHAMY E. F. , KHEDR D. M.
Published: February 2013

Investigation of arbitrary amplitude nonlinear ion-acoustic solitary waves which accompany collisionless positive–negative ion plasmas with high-energy electrons (represented by kappa distribution) is presented. Arbitrary amplitude solitary waves are investigated by deriving an energy-integral equation involving a Sagdeev-like pseudopotential. The existence regions of solitary pulses are, defined precisely, modified by the superthermality of energetic electrons. Furthermore, numerical calculations reveal that both compressive and rarefactive pulses may exist for negative ion mass groups in Titan's atmosphere. The superthermality of energetic electrons are found to modify the existence domains of large amplitude ion-acoustic waves in Titan's atmosphere. The dependence of solitary excitation characteristics on the superthermal parameter, the negative ion concentration, the positive-to-negative ions mass ratio, and the Mach number have been investigated. The present study might be helpful to understand the excitation of fully nonlinear ion-acoustic solitary pulses that may appear in the interplanetary medium and/or in the astrophysical plasmas in general.
RHODODENDRON MECHUKAE (ERICACEAE), A NEW SPECIES FROM INDIA
Authors: Mao A. A. , Bhaumik M. , Paul A. , Bharali S. , Khan M. L.
Published: February 2013

The new species Rhododendron mechukae A.A.Mao & A.Paul (Ericaceae) is described from India.
A REVISION OF RHYNCHOTECHUM BLUME (GESNERIACEAE)
Authors: Anderson B. M. , Middleton D. J.
Published: February 2013

The genus Rhynchotechum Blume (Gesneriaceae) is revised. It consists of 16 species, three of which are newly described here: Rhynchotechum burmanicum B.M.Anderson from Burma, R. gracile B.M.Anderson from Northeast India, and R. vietnamense B.M.Anderson from Vietnam. A new combination is made for Rhynchotechum hookeri (C.B.Clarke) B.M.Anderson. A key and descriptions of all species are provided.