bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical Simulation and Investigation of High Frequency Tube Welding Process
Authors: Nikanorov Aleksandr , Baake Egbert , Neumeyer Jörg
Published: December 2014

Welding processes and installations used nowadays are mainly developed on practical experience and analytical calculations. Nevertheless, high frequency induction tube welding is a very complex three-dimensional dynamic process, where the electromagnetic and thermal characteristics are distributed not only in space but in time as well. A more profound detailed investigation of the induction tube welding process can be only done by numerical modeling. Full and local three-dimensional transient numerical models of induction tube welding process with continuous movement of the welded tube have been developed and tested. Coupled electromagnetic and thermal analyses are carried out at each time step of simulation for correction of temperature dependent material properties. Voltage or current of the induction coil can be individually input into electromagnetic analysis at each time step. This approach allows simulating “quasi” steady-state and transient operation modes.
Microstructural and Tribological Characterization of Atmospheric Plasma-Nitrided HS6-5-2C Tool Steel
Authors: Lizunkova Yana , Tyurin Andrey , Hassel Thomas
Published: December 2014

The nitriding process is well known as a method to improve wear, strength and corrosion characteristics of materials surface. The Institute of Materials Science of Leibniz Universität Hannover is on a stage of development of a new nitriding process under atmospheric conditions. The main purpose of the research work is formation of a nitrided layer on the locally loaded areas of a tool (e.g. forging die) under atmospheric conditions to increase wear resistance and durability of operating tools. Nitride layers were generated on the tool steel HS6-5-2C using the transmitted plasma arc. After atmospheric plasma nitriding the samples were investigated using optical microscopy, transmission electron microscopy (TEM), X-Ray diffraction (XRD) and microhardness testing techniques. It has been revealed that the modified zone thickness after atmospheric plasma nitriding reaches 200 μm. TEM and XRD analysis have shown that new phases corresponding to iron nitrides were formed in the surface zone. Microhardness of the surface layer is increased by 10% and friction coefficient has been reduced by approximately 50% in comparison with base material.
Study of the Temperature Effect on the Structure and Thickness of Hot-Dip Zinc Coatings on Fixing Products
Authors: Bondareva Olga
Published: December 2014

Hot-dip galvanizing of steels is usually performed by immersing the metal in a bath with molten zinc in the temperature range from 450 to 460 °C. In some cases it is necessary to obtain a minimal coating thickness. For example, high-strength bolts and other fixing products require a minimal thickness of the coating because a too thick zinc coating requires additional work on re-threading, which leads to spalling of coatings, a loss of corrosion resistance and, consequently, failure of the entire product. The main aim of this work was to study the influence of elevated temperatures of hot-dip galvanizing on the thickness and microstructure of zinc coatings on bolts and nut preform. The microstructure and elemental composition of the coating were studied by scanning electron microscopy and energy dispersion X-ray microanalysis. It was found that the coating thickness obtained in the range between 475 and 535°C decreases with temperature and reaches a minimum at 535°C. The structure of the coating after high-temperature hot-dip galvanizing was fundamentally different from the structure of the coating made at standard temperatures 450-460°C. This coating formed at 535°C was dense, homogeneous, non-porous and composed of a mixture of the δ and ζ-phases without distinct phase boundaries. That’s why it was recommended to maintain the bath temperature in the range between 533°C and 537°C. It allows us to obtain a hot-dip galvanized coating of a minimal thickness and a good quality on fixing products.
Combined Thermomechanical Treatment for the Mining Industry
Authors: Popelyukh Albert , Yurkevich Maria , Popelyukh Pavel
Published: December 2014

A new method for combined thermo-mechanical treatment of steel 0.4 % C, 1.5 % Cr, 1.5 % Ni, 0.5 % Mo is developed. Thermo-mechanical processing includes hot forging and rapid cooling to the temperature range between the beginning and end of martensitic transformation. The final stage of heat treatment is heating up to the temperature of bainite transformation in which the remaining austenite transforms into a bainite structure and previously formed martensite tempers. In comparison with well known techniques of thermal treatment, the developed thermo-mechanical treatment increases the impact toughness of the steel by 2 times and fatigue crack resistance by 6 times (with equal values of strength parameters). The technological process of high-temperature thermo-mechanical treatment is recommended for treatment of high-strength blank forging.
Researches Structure and Properties of Self-Fluxing Coating, Obtained by Air-Plasma Spraying
Authors: Kornienko Elena , Smirnov Aleksandr , Kuz'min Victor
Published: December 2014

The structural features of self-fluxing coatings obtained by air-plasma spraying with a unit of annular injection of powder are discussed in the article. It is shown that the application of an annular injection unit makes it possible to increase significantly the efficiency of particle heating in contrast to the point injection of a powder into the plasma jet. It is shown by optical and scanning electron microscopy that the major part of particles which form the coating is in a molten or plasticized condition in the plasma jet. It is revealed by transmission electron microscopy that a high cooling rate of these particles contributes to the formation of the γ-submicrocrystalline supersaturated Ni-based solid solution with an average grain size of 80 nm. To provide high technological and tribological properties it is necessary to carry out plasma spraying at an arc current less than 170 A.
Design Optimization of Small Shaped Charges with the Use of Complex Casing
Authors: Nurmukhametov A.T. , Popov A.G. , Demoretsky D.A.
Published: December 2014

A new design of shaped charges with a complex cumulative casing was proposed. The casing consists of two parts: conical and spherical. Mathematical modeling is conducted to determine the optimum shape of the cumulative casing. The feasibility of increasing the inlet area formed at detonation of the proposed shaped charge up to 2.8 times has been demonstrated.
Microgrid Operation under Frequency Control Method
Authors: Armeev D.V. , Arestova A.Y. , Abramova Y.A.
Published: December 2014

Intensive development of cogeneration and SmartGrid technologies provide an opportunity to form Microgrid within a distribution system. Microgrid can act as part of an interconnected power system or operate in isolated mode. Islanding is performed under faults, power interruption, etc. There are several technical problems when Microgrid resynchronizes to the grid. This paper presents three control strategies to be used to reconnect with the utility: 1. without any emergency control actions; 2. frequency load shedding; 3. frequency control method.
Proceedings of the 24th National Congress of the "Gruppo Italiano per lo Studio della Neuromorfologia" G.I.S.N., Bologna, November 28-29, 2014
Authors: Marina Del Fiacco President:
Published: December 2014

Proceedings of the 24th National Congress of the "Gruppo Italiano per lo Studio della Neuromorfologia" G.I.S.N., Bologna, November 28-29, 2014
Aligning Web content and organisational strategy: Towards increasing funding
Authors: Maahlo Khutso , Ratsoana Molefe , Mearns Martie A.
Published: December 2014

Background: The effectiveness with which the Aurum Institute manages to communicate its organisational strategic objectives through its website was investigated. Despite its ground breaking research and programs which have made a positive impact on the community, the major problem that it faces is funding its core.Objectives: An investigation of the website’s content was carried out to determine the extent to which the organisational strategy is reflected to potential funders visiting the site. Requirements for aligning the content with the organisational strategy were identified.Method: Content analysis was used where secondary data, such as website content and organisational strategic objectives, was analysed. An interview was also conducted with Aurum’s knowledge manager to gain an in-depth understanding of the organisation’s strategic objectives and to validate the initial findings.Results: The results show that the website content was not effectively representative of Aurum’s strategic objectives, and that the website structure did not effectively share the information that supports the decision-making process of potential investors. Recommendations were presented to the organisation in the form of a prototype website which reflects the desired website content that is representative of Aurum’s strategic objectives.Conclusion: Further research is required in determining the effect that a strategically driven website could possibly exert on the funding potential of the organisation. The theoretical approach used in this study can be used as a scoping exercise in organisations of a similar business nature.
Preserving traditional medical knowledge through modes of transmission: A post-positivist enquiry
Authors: Adekannbi Janet , Olatokun Wole M. , Ajiferuke Isola
Published: December 2014

Background: In Nigeria, most rural communities lack access to orthodox medical facilities despite an expansion of orthodox health care facilities and an increase in the number of orthodox health care providers. Over 90% of Nigerians in rural areas thus depend wholly or partly on traditional medicine. This situation has led to a call for the utilisation of Traditional medical practitioners in primary-healthcare delivery. Hence, the persistence of the knowledge of traditional medicine, especially in the rural communities where it is the only means of primary health care, has been a concern to information professionals.Objectives: This study investigated the role which the mode of transmission plays in the preservation of traditional medical knowledge.Method: A post-positivist methodology was adopted. A purposive sampling technique was used to select three communities from each of the six states in South-Western Nigeria. The snowball technique was used in selecting 228 traditional medical practitioners, whilst convenience sampling was adopted in selecting 529 apprentices and 120 children who were not learning the profession. A questionnaire with a five-point Likert scale, key-informant interviews and focus-group discussions were used to collect data. The quantitative data was analysed using descriptive statistics whilst qualitative data was analysed thematically.Results: The dominant mode of knowledge transmission was found to be oblique (66.5%) whilst vertical transmission (29.3%) and horizontal transmission (4.2%) occurred much less.Conclusion: Traditional medical knowledge is at risk of being lost in the study area because most of the apprentices were children from other parents, whereas most traditional medical practitioners preferred to transmit knowledge only to their children.
Deep Sequencing of Serum Small RNAs Identifies Patterns of 5′ tRNA Half and YRNA Fragment Expression Associated with Breast Cancer
Authors: Dhahbi Joseph M. , Spindler Stephen R. , Atamna Hani , Boffelli Dario , Martin David I.K.
Published: December 2014

Small noncoding RNAs circulating in the blood may serve as signaling molecules because of their ability to carry out a variety of cellular functions. We have previously described tRNA- and YRNA-derived small RNAs circulating as components of larger complexes in the blood of humans and mice; the characteristics of these small RNAs imply specific processing, secretion, and physiological regulation. In this study, we have asked if changes in the serum abundance of these tRNA and YRNA fragments are associated with a diagnosis of cancer. We used deep sequencing and informatics analysis to catalog small RNAs in the sera of breast cancer cases and normal controls. 5′ tRNA halves and YRNA fragments are abundant in both groups, but we found that a breast cancer diagnosis is associated with changes in levels of specific subtypes. This prompted us to look at existing sequence datasets of serum small RNAs from 42 breast cancer cases, taken at the time of diagnosis. We find significant changes in the levels of specific 5′ tRNA halves and YRNA fragments associated with clinicopathologic characteristics of the cancer. Although these findings do not establish causality, they suggest that circulating 5′ tRNA halves and YRNA fragments with known cellular functions may participate in breast cancer syndromes and have potential as circulating biomarkers. Larger studies with multiple types of cancer are needed to adequately evaluate their potential use for the development of noninvasive cancer screening.
Quality assurance systems of higher education - The case of european institutions: origin, evolution and trends
Authors: Corengia Ángela , Del Bello Juan Carlos , Pita Carranza María , Adrogué Cecilia
Published: December 2014

The purpose of this research is to analyze the origin, evolution, performance and trends of higher education quality assurance systems in the following European countries: Denmark, Norway, Sweden, Finland, Austria, Italy, Switzerland, Germany, Netherlands, United Kingdom and France. It also studies the performance and impact of the organizations that join the European Quality Assurance Agencies together. The main sources of data collection were in situ semi-structured interviews to members of these agencies. It was found that in higher education institutions there is a strong trend towards the development of ‘internal quality assurance systems' in response to the public policies known as 'quality audits'. This overview about what is taking place in Europe may provide innovative instruments that could be considered for higher education quality evaluation and accreditation in Latin-American countries: quality audits, disciplinary agencies, evaluation of the quality assurance agencies, among others.
Dependence of the cyclization of branched tetraethers on soil moisture in alkaline soils from arid–subhumid China: implications for palaeorainfall reconstructions on the Chinese Loess Plateau
Authors: Wang H. , Liu W. , Zhang C. L.
Published: December 2014

Abstract. The use of branched glycerol dialkyl glycerol tetraethers (bGDGTs) in loess–palaeosol sequences (LPSs) has shown promises in continental palaeotemperature reconstructions. Thus far, however, little is known about the effect of soil moisture on their distributions in the water-limited Chinese Loess Plateau (CLP). In this study, the relationships between environmental variables and the cyclization of branched tetraethers (CBT) were investigated in arid–subhumid China using 97 surface soils in the CLP and its vicinity, as well as 78 soils with pH > 7 which have been previously published. We find that CBT correlates best with soil water content (SWC) or mean annual precipitation (MAP) for the overall data set. This indicates that CBT is mainly controlled by soil moisture instead of soil pH in alkaline soils from arid–subhumid regions, where water availability is a limiting factor for the producers of bGDGTs. Therefore, we suggest that CBT can potentially be used as a palaeorainfall proxy on the alkaline CLP. According to the preliminary CBT–MAP relationship for modern CLP soils (CBT = −0.0021 × MAP + 1.7, n = 37, r = −0.93), palaeorainfall history was reconstructed from three LPSs (Yuanbao, Lantian, and Mangshan) with published bGDGT data spanning the past 70 ka. The CBT-derived MAP records of the three sites consistently show precession-driven variation resembling the monsoon record based on speleothem δ18O, supporting CBT as a reasonable proxy for palaeorainfall reconstruction in LPS. The direct application of CBT as a palaeorainfall proxy in corroboration with the bGDGT-based temperature proxy may enable us to further assess the temperature/hydrological association for palaeoclimate studies on the CLP.
A multi-layer land surface energy budget model for implicit coupling with global atmospheric simulations
Authors: Ryder J. , Polcher J. , Peylin P. , Ottlé C. , Chen Y. , van Gorsel E. , Haverd V. , McGrath M. J. , Naudts K. , Otto J. , Valade A. , Luyssaert S.
Published: December 2014

Abstract. In Earth system modelling, a description of the energy budget of the vegetated surface layer is fundamental as it determines the meteorological conditions in the planetary boundary layer and as such contributes to the atmospheric conditions and its circulation. The energy budget in most Earth system models has long been based on a "big-leaf approach", with averaging schemes that represent in-canopy processes. Such models have difficulties in reproducing consistently the energy balance in field observations. We here outline a newly developed numerical model for energy budget simulation, as a component of the land surface model ORCHIDEE-CAN (Organising Carbon and Hydrology In Dynamic Ecosystems – CANopy). This new model implements techniques from single-site canopy models in a practical way. It includes representation of in-canopy transport, a multilayer longwave radiation budget, height-specific calculation of aerodynamic and stomatal conductance, and interaction with the bare soil flux within the canopy space. Significantly, it avoids iterations over the height of tha canopy and so maintains implicit coupling to the atmospheric model LMDz. As a first test, the model is evaluated against data from both an intensive measurement campaign and longer term eddy covariance measurements for the intensively studied Eucalyptus stand at Tumbarumba, Australia. The model performs well in replicating both diurnal and annual cycles of fluxes, as well as the gradients of sensible heat fluxes. However, the model overestimates sensible heat flux against an underestimate of the radiation budget. Improved performance is expected through the implementation of a more detailed calculation of stand albedo and a more up-to-date stomatal conductance calculation.
MEMBRANA BIOLÓGICA (Biofill ) - ESTUDO COMPARATIVO COM OUTROS AGENTES PROMOTORES DA CICATRIZAÇÃO DA PELE EM SUÍNOS: ASPECTOS CLÍNICOS, HISTOPATOLÓGICOS E MORFOMÉTRICOS
Authors: WOUK ANTÔNIO FELIPE PAULINO DE FIGUEIREDO , DINIZ JOÃO MARIA , CÍRIO SILVANA MARIS , DOS SANTOS HUDSON , BALTAZAR ELISA LETÍCIA , ACCO ALEXANDRA
Published: December 2014

Com o objetivo de comparar a ação de diferentes agentes terapêuticos promotores da cicatrização da pele, foi realizado um estudo clínico, histopatológico e morfométrico em suíno. Utilizou-se seis animais mestiços provenientes de uma mesma leitegada com 90 dias de idade. Foram produzidas seis lesões experimentais quadrangulares do mesmo tamanho na região dorso-lombar e uma delas permaneceu como controle. Em cada animal, foram testados cinco tratamentos: Biofill humano, Biofill veterinário, Tegaderm, Duoderm e Nitrofurazona. Foram realizadas biópsias aos 7, 14, 21, 45 e 60 dias da evolução cicatricial, seguidas de análise histopatológica. No período de 7 a 45 dias, realizou-se morfometria - perímetro e superfície inscrita - dos leitos cicatriciais. Foram as seguintes as membranas, pela ordem de eficiência, não só quanto à cicatrização mas também com relação à adesão ao leito da ferida: Biofill Humano, Biofill Veterinário, Tegaderm e Duoderm. A Nitrofurazona comportou-se, em relação ao aspecto cicatricial, de uma forma muito próxima à do Biofill; contanto, a necessidade de trocas diárias de curativos tornou o tratamento difícil. Abstract In order to compare different skin healing promoters, it was conducted a clinical, histopathological and morphometric study in swine. Six cross bred 90 days old animals from the same parturition were employed. Six experimental quadrangular wounds were made over the back region of each animal, one of them remaing as control. Five treatments were tested: Human Biofill, Veterinary Biofill, Tegaderm, Duoderm and Nitrofurazone At days 7, 14, 21, 45 and 60, biopsies for histopathological analysis were carried out. From de 7th to the 45th day, a morphometric study (perimeter and area) of the healing wounds beds was achieved. With the criteria of healing quality and adhesion to the wound the occlusive dressings in order of efficiency were: Human Biofill, Veterinary Biofill, Tegaderm and Duoderm. Nitrofurazone showed good healing qualities needing however daily changes of dressings.
INSEMINAÇÃO ARTIFICIAL EM ÉGUAS COM SÊMEN "IN NATURA" E DILUÍDO
Authors: WEISS R.R. , VIANNA B.C. , MURADÁS P.R.
Published: December 2014

Na pesquisa objetivou-se comparar a eficiência reprodutiva de dois métodos distintos de Inseminação Artificial (IA), através de espéculo de Polansky e condução manual de pipeta, com diferentes características de sêmen ("in natura" e diluído). Foram utilizadas 302 éguas da raça Crioula, com idades variando entre 3 e 14 anos, oriundas de propriedades da região Metropolitana de Curitiba. Os animais foram divididos em dois grupos experimentais: A - aqueles que foram inseminados com sêmen "in natura" (n=160); através da técnica com espéculo de Polansky (n=80) e pipeta orientada manualmente (n=80); B - animais inseminados com sêmen diluído (n=142). O acompanhamento do ciclo estral foi realizado através de ultrassonagrafia e palpação retal bem como o diagnóstico de gestação que foi realizado entre os dias 16-45 pós-ovulação. A eficiência reprodutiva das duas técnicas de inseminação (Polansky e Manual) foi de 76,2% e 75% respectivamente, não diferindo significativamente entre si, bem como a eficiência reprodutiva dos resultados da inseminação com sêmen diluído e "in natura" foram 74,3% e 75,5% respectivamente. Artificial insemination in mares with in natura and diluted semen Abstract With the aim to compare the reproductive efficiency of two different methods for articial insemination, namely through the Polanskyís speculum and by a manual directed pipette, with semen either îin naturaî or diluted, 302 mares of the Creole race, ageing from 3 to 14 years, all of them belonging to properties from the Metropolitan Area of Curitiba, were used divided in two experimental groups: A ñ those that would be inseminated with semen ìin naturaî (n=160), being 80 with Polanskyís spectrum and 80 by means of a manual directed pipette; B ñ animals inseminated with diluted semen (n=142). The following up of the estral cycle was accomplished by means of ultrasonography and rectal palpation as well as the gestation diagnosis, which was accomplished at 16 to 45 days after the ovulation. The reproductive efficiency of the two insemination techniques (Polansky and Manual) was 76,25% and 75%, respectively, not differing significantly between each other. The reproductive efficiency of the results of the insemination with diluted semen and ìin naturaî was 74,3% and 75,5%, respectively.
The High-pressure Thallium Triborate HP-TlB3O5
Authors: Sohr Gerhard , Perfler Lukas , Huppertz Hubert
Published: December 2014

The thallium triborate HP-TlB3O5 (HP=high-pressure) was synthesized in a Walker-type multianvil apparatus under high-pressure=high-temperature conditions of 6 GPa and 1400°C. A mixture of thallium carbonate Tl2CO3 and boric acid H3BO3 initially heated at 850°C under ambient-pressure conditions was used as a precursor for the high-pressure experiment. Single-crystal X-ray diffraction data revealed that HP-TlB3O5 is isotypic to HP-M′B3O5 (M′ =K, Rb). Furthermore the B-O network is identical to the substitutional variants HP-M″B3O5 [M″ =Cs1-x(H3O)x (x=0.5 - 0.7), NH4]. HP-TlB3O5 crystallizes with eight formula units (Z =8) in the monoclinic space group C2=c (no. 15). The lattice parameters are a=996.3(2), b=884.0(2), c=913.1(2) pm, β =103:3(1)°, and V =782.5(3) Å3. Trigonal-planar BO3 groups, corner-sharing BO4 tetrahedra, and B2O6 groups consisting of two edge-sharing BO4 tetrahedra are present in the structure, forming a three-dimensional network. The thallium ions are located in channels of the boron-oxygen network being tenfold coordinated by oxygen atoms and do not show any lone pair effect at all. IR and Raman spectroscopic investigations were performed on single crystals of the compound.
Synthesis and Characterization of Silver(I) and Gold(I) Complexes Bearing a Pyrido-annelated N-Heterocyclic Carbene: A Rare Example of a Cocrystal Containing Two Different Gold(I) Complexes
Authors: Kriechbaum Margit , Otte Daniela , List Manuela , Monkowius Uwe
Published: December 2014

The cyclohexyl-substituted imidazo[1,5-a]pyridin-2-ium hexafluorophosphate, 2a, has been prepared as precursor for the respective pyrido-annelated N-heterocyclic carbene. [(NHC)2Ag]PF6, 3, has been synthesized by the reaction of 2a with AgCl=KOH in dichloromethane (DCM). Unexpectedly, the reaction of 3 with (tht)AuBr yielded both (NHC)AuBr and [(NHC)Au(tht)]PF6 which formed a 1 : 1 cocrystal (4a,b). The complexes are aggregated to infinite chains, which are governed by both π-π stacking and weak aurophilic interactions. Subsequent oxidation of the co-crystalline material with CsBr3 gave (NHC)AuBr3, 5. All compounds were characterized by NMR spectroscopy, mass spectrometry and elemental analysis. Additionally, compounds 2a and 5 were investigated by electronic spectroscopy: 2a behaves like a typical aromatic compound exhibiting absorption and fluorescence bands attributable to π-π* transitions. The Au(III) complex 5 exhibits ligand-centered fluorescence at room temperature and both ligand-centered fluorescence and a weak phosphorescence at 77 K.
Imine-coordinated 2-Aminoazole Complexes of Au(I): Complicating Reactions and Verification of Products by Crystal Structure Determination
Authors: de Jongh Leigh-Anne , Dobrzańska Liliana , Strasser Christoph E. , Raubenheimer Helgard G. , Cronje Stephanie
Published: December 2014

When Au(I) is provided with endocyclic soft thioether or endocyclic hard amine, endocyclic borderline imine and exocyclic hard amine coordination sites, the softer borderline endocyclic imine coordination site is favored. This is demonstrated by the synthesis and structural characterization (IR, MS, 1H, 13C and 31P NMR experiments and single-crystal X-ray diffraction analysis) of 2-aminoazole (2-amino-4-methylthiazole, 2-aminobenzothiazole and 2- aminobenzimidazole) complexes of [AuPPh3]+ (1-3). An unusual ring opening is observed for the reaction of 2-aminothiazoline with [Au(NO3)PPh3] yielding μ2-(2-mercapto-ethyl-cyanamide- k,S)bis(triphenylphosphine)gold(I) nitrate (4). Reactions of 2-aminoazoles with Au(C6F5)THT (THT=tetrahydrothiophene) yield [Au(C6F5)2]- stabilized by various cations. The formation of Au(2-aminothiazoline)C6F5 is again the exception
Los múltiples usos de la diversidad cultural: la diversidad cultural ante el racismo, el desarrollo y la globalización en los documentos UNESCO
Authors: Velasco Honorio M.
Published: December 2014

Más que el concepto de diversidad cultural interesa el análisis de los usos de ella. En particular resulta relevante el empleo primero débil y luego, firme, casi profuso por parte de instituciones culturales como la UNESCO con numerosos documentos generados para que sirvan de criterio de las políticas culturales de los estados que los suscriben. Se muestra que a lo largo del tiempo la diversidad cultural ha sido empleada para contrarrestar, subvertir, reorientar, resistir fenómenos sociales tan potentes como el racismo, el desarrollo, la globalización, con distinta suerte y muy variados cambios en su concepción.
Professional Noticing: Developing Responsive Mathematics Teaching
Authors: Thomas Jonathan N. , Eisenhardt Sara , Fisher Molly H. , Schack Edna O. , Tassell Janet , Yoder Margaret
Published: December 2014

Learn how to coordinate the use of CCSSM with this emerging framework to attend to children's actions, make interpretations, and respond with robust instruction.
The export receptor Crm1 forms a dimer to promote nuclear export of HIV RNA
Authors: Booth David S , Cheng Yifan , Frankel Alan D
Published: December 2014

The HIV Rev protein routes viral RNAs containing the Rev Response Element (RRE) through the Crm1 nuclear export pathway to the cytoplasm where viral proteins are expressed and genomic RNA is delivered to assembling virions. The RRE assembles a Rev oligomer that displays nuclear export sequences (NESs) for recognition by the Crm1-RanGTP nuclear receptor complex. Here we provide the first view of an assembled HIV-host nuclear export complex using single-particle electron microscopy. Unexpectedly, Crm1 forms a dimer with an extensive interface that enhances association with Rev-RRE and poises NES binding sites to interact with a Rev oligomer. The interface between Crm1 monomers explains differences between Crm1 orthologs that alter nuclear export and determine cellular tropism for viral replication. The arrangement of the export complex identifies a novel binding surface to possibly target an HIV inhibitor and may point to a broader role for Crm1 dimerization in regulating host gene expression.
Avaliadores, autores e informações editoriais
Authors: Anjos Sara Joana Gadotti dos
Published: December 2014

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Petit Lumbar Hernia—a Double-Layer Technique for Tension-Free Repair
Authors: Bigolin André Vicente , Rodrigues André Petter , Trevisan Camila Gueresi , Geist Ana Brochado , Coral Roberto Viña , Rinaldi Natalino , Coral Roberto Pelegrini
Published: December 2014

This report describes an alternative technique for Petit hernia repair. The treatment of lumbar hernias should follow the concept of tension-free surgery, and the preperitoneal space can be the best place for prosthesis placement. An obese patient had a bulge in the right lumbar region, which gradually grew and became symptomatic, limiting her daily activities and jeopardizing her quality of life. She had previously undergone 2 surgical procedures with different incisions. We created a preperitoneal space and attached a mesh in this position. Another prosthesis was placed on the muscles, with a suitable edge beyond the limits of the defect. There were no complications. It has been described as a safe and tension-free repair for Petit hernia. In larger defects, a second mesh can be used to prevent further enlargement of the triangle and also to provide additional protection beyond the bone limits.
Changes in the Frequencies of Abdominal Wall Hernias and the Preferences for Their Repair: A Multicenter National Study From Turkey
Authors: Şeker Gaye , Kulacoglu Hakan , Öztuna Derya , Topgül Koray , Akyol Cihangir , Çakmak Atıl , Karateke Faruk , Özdoğan Mehmet , Ersoy Eren , Gürer Ahmet , Zerbaliyev Elbrus , Seker Duray , Yorgancı Kaya , Pergel Ahmet , Aydın İbrahim , Ensari Cemal , Bilecik Tuna , Kahraman İzzettin , Reis Erhan , Kalaycı Murat , Canda Aras Emre , Demirağ Alp , Kesicioğlu Tuğrul , Malazgirt Zafer , Gündoğdu Haldun , Terzi Cem
Published: December 2014

Abdominal wall hernias are a common problem in the general population. A Western estimate reveals that the lifetime risk of developing a hernia is about 2%.1–3 As a result, hernia repairs likely comprise the most frequent general surgery operations. More than 20 million hernias are estimated to be repaired every year around the world.4 Numerous repair techniques have been described to date however tension-free mesh repairs are widely used today because of their low hernia recurrence rates. Nevertheless, there are some ongoing debates regarding the ideal approach (open or laparoscopic),5,6 the ideal anesthesia (general, local, or regional),7,8 and the ideal mesh (standard polypropylene or newer meshes).9,10
Trends in the Brazil/Malvinas Confluence region
Authors: Combes Vincent , Matano Ricardo P.
Published: December 2014

Observations show abrupt changes in the oceanic circulation of the southwestern Atlantic. These studies report a southward drift of the Brazil/Malvinas Confluence (BMC) and a change in the spectral characteristics of the Malvinas Current (MC) transport. We address the cause of these changes using the result of a high‐resolution numerical experiment. The experiment, which is consistent with observations, shows a southward BMC displacement at a rate of 0.62°/decade between 1993 and 2008, and a shift of the spectral characteristics of the MC transport after 1999. We find that these changes are driven by a weakening of the northern branch of the Antarctic Circumpolar Current, which translates to a weakening of the MC transport and a southward BMC drift. The drift changes the spectral characteristics of the MC transport, which becomes more influenced by annual and semiannual variations associated with the BMC.
History of Correlational Measurement
Authors: Cowles Michael
Published: December 2014

The beginnings of attempts to index the relationship between two or more variables began in the nineteenth century. A number of mathematicians produced theoretical underpinnings that lead to the concept of correlation, but none appreciated the practical applications of the method. Galton looked at correlation in the context of heredity with the aim of providing objective mathematical descriptions that would bolster his belief in, and demonstrate the truth of the social philosophy of planned heredity that he named
eugenics
. Pearson, a mathematician and also a eugenist, arrived at the best formula for the coefficient of correlation and it was named after him. Later, the methods of partial and multiple correlation followed. The methods of factor analysis were introduced and techniques for handling relationships among ordinal and nominal data added to the growing collection of statistical methods in the behavioral and biological sciences.
Multilingualism and Memory
Authors: Kazanas Stephanie A. , Altarriba Jeanette
Published: December 2014

Research with multilinguals has highlighted the general memory advantages of knowing more than one language. For example, Schroeder and Marian have cited better executive functioning in bilinguals than monolinguals, and research in the medical field has found a buffering effect of multilingualism on memory loss in the elderly. Other research has emphasized the differences in memory capacity or memory effects in a native language (L1) versus a second (L2) or third language. Although the focus of this entry is on the more applied areas of memory research with bilinguals and multilinguals, a brief primer on some basic findings with these populations is useful
Wilson,Deirdre and Relevance Theory
Authors: Allott Nicholas
Published: December 2014

Deirdre Wilson (born 1941) is one of the key figures in the history of pragmatics since its emergence as a distinct field of research in the 1970s. She is professor of linguistics (now emerita) at the Division of Psychology and Language Sciences at University College London, and, since 2007, a research director of the Centre for the Study of Mind in Nature at the University of Oslo. With Dan Sperber she is the co‐founder of relevance theory, a theory of cognition and communication that is one of the leading programs of research in linguistic pragmatics and related areas.
Grammar and Institutional Discourse
Authors: Diani Giuliana
Published: December 2014

Institutional discourse is the specialized discourse used by social actors in various institutional contexts, such as law courts, universities, and public administrations, among others. This type of discourse can, of course, vary widely: it can be written or oral, formal/informal, use various channels (e.g., e‐mail, Web site), and exploit various registers and genres. In all these varieties, the discourse is very “managed” in the sense that lexical, grammatical, and rhetorical choices made by speakers and writers are crucial in implementing their goals.
Conversation Analysis of Computer‐Mediated Interactions
Authors: Tudini Vincenza
Published: December 2014

This entry provides a brief overview of research which has been conducted using a conversation analysis (CA) approach to understand computer‐mediated interactions (henceforth CMIs). An increasing number of researchers use CA to investigate CMIs, because this methodology engages in systematic analysis of talk in everyday naturally occurring situations of social and institutional interaction. CA's central concern with interaction between human beings has provided researchers with a robust methodological foundation, based on previous work on phone and face‐to‐face conversation, to investigate new and unique forms of interaction in online settings, where participants are using either their first, additional or a foreign language (L1 or L2).
Insights into the Catalytic Activity of Nitridated Fibrous Silica (KCC‐1) Nanocatalysts from 15N and 29Si NMR Spectroscopy Enhanced by Dynamic Nuclear Polarization
Authors: Lilly Thankamony Aany Sofia , Lion Cédric , Pourpoint Frédérique , Singh Baljeet , Perez Linde Angel J. , Carnevale Diego , Bodenhausen Geoffrey , Vezin Hervé , Lafon Olivier , Polshettiwar Vivek
Published: December 2014

Fibrous nanosilica (KCC‐1) oxynitrides are promising solid‐base catalysts. Paradoxically, when their nitrogen content increases, their catalytic activity decreases. This counterintuitive observation is explained here for the first time using 15N‐solid‐state NMR spectroscopy enhanced by dynamic nuclear polarization.
An Organic Molecule with Asymmetric Structure Exhibiting Aggregation‐Induced Emission, Delayed Fluorescence, and Mechanoluminescence
Authors: Xu Shidang , Liu Tingting , Mu Yingxiao , Wang Yi‐Fan , Chi Zhenguo , Lo Chang‐Cheng , Liu Siwei , Zhang Yi , Lien Alan , Xu Jiarui
Published: December 2014

Compounds displaying delayed fluorescence (DF), from severe concentration quenching, have limited applications as nondoped organic light‐emitting diodes and material sciences. As a nondoped fluorescent emitter, aggregation‐induced emission (AIE) materials show high emission efficiency in their aggregated states. Reported herein is an AIE‐active, DF compound in which the molecular interaction is modulated, thereby promoting triplet harvesting in the solid state with a high photoluminescence quantum yield of 93.3 %, which is the highest quantum yield, to the best of our knowledge, for long‐lifetime emitters. Simultaneously, the compound with asymmetric molecular structure exhibited strong mechanoluminescence (ML) without pretreatment in the solid state, thus exploiting a design and synthetic strategy to integrate the features of DF, AIE, and ML into one compound.
High Catalytic Activity of Nitrogen and Sulfur Co‐Doped Nanoporous Graphene in the Hydrogen Evolution Reaction
Authors: Ito Yoshikazu , Cong Weitao , Fujita Takeshi , Tang Zheng , Chen Mingwei
Published: December 2014

Chemical doping has been demonstrated to be an effective way to realize new functions of graphene as metal‐free catalyst in energy‐related electrochemical reactions. Although efficient catalysis for the oxygen reduction reaction (ORR) has been achieved with doped graphene, its performance in the hydrogen evolution reaction (HER) is rather poor. In this study we report that nitrogen and sulfur co‐doping leads to high catalytic activity of nanoporous graphene in HER at low operating potential, comparable to the best Pt‐free HER catalyst, 2D MoS2. The interplay between the chemical dopants and geometric lattice defects of the nanoporous graphene plays the fundamental role in the superior HER catalysis.
Air‐Stable Cationic Gold(I) Catalyst Featuring a Z‐Type Ligand: Promoting Enyne Cyclizations
Authors: Inagaki Fuyuhiko , Matsumoto Chiaki , Okada Yasuhiko , Maruyama Naoya , Mukai Chisato
Published: December 2014

An air‐stable cationic AuI complex featuring a Z‐type ligand (boron atom) as a σ‐acceptor was developed for elucidating the effect of B on catalytic reactions. An enyne cyclization in the presence of either [Au→B]+ or [Au]+ showed that [Au→B]+ promotes the reactivity, which enabled the effective construction of not only five‐ and six‐membered rings, but also seven‐membered rings.
Hydrogen Storage Materials: Room‐Temperature Wet‐Chemistry Approach toward Mixed‐Metal Borohydrides
Authors: Jaroń Tomasz , Orłowski Piotr A. , Wegner Wojciech , Fijałkowski Karol J. , Leszczyński Piotr J. , Grochala Wojciech
Published: December 2014

The poor kinetics of hydrogen evolution and the irreversibility of the hydrogen discharge hamper the use of transition metal borohydrides as hydrogen storage materials, and the drawbacks of current synthetic methods obstruct the exploration of these systems. A wet‐chemistry approach, which is based on solvent‐mediated metathesis reactions of precursors containing bulky organic cations and weakly coordinating anions, leads to mixed‐metal borohydrides that contain only a small amount of “dead mass”. The applicability of this method is exemplified by Li[Zn2(BH4)5] and M[Zn(BH4)3] salts (M=Na, K), and its extension to other systems is discussed.
LED‐Illuminated NMR Studies of Flavin‐Catalyzed Photooxidations Reveal Solvent Control of the Electron‐Transfer Mechanism
Authors: Feldmeier Christian , Bartling Hanna , Magerl Kathrin , Gschwind Ruth M.
Published: December 2014

Mechanistic insights into chemical photocatalysis are mainly the domain of UV/Vis spectroscopy, because NMR spectroscopy has been limited by the type of illumination so far. An improved LED‐based illumination device can be used to obtain NMR reaction profiles of photocatalytic reactions under synthetic conditions and perform both photo‐CIDNP and intermediate studies. Flavin‐catalyzed photooxidations of alcohols show the potential of this setup. After identical initial photoreaction steps the stabilization of a downstream intermediate is the key to the further reaction mechanism and the reactivity. As a chemical photocatalyst flavin can act either as a one‐ or a two‐electron mediator when the stability of the zwitterionic radical pair is moldulated in different solvents. This demonstrates the importance of downstream intermediates and NMR‐accessible complementary information in photocatalytic reactions and suggests the control of photoorganic reactions by solvent effects.
Reply to Comment on “Breakdown of Crystallographic Site Symmetry in Lanthanide‐Doped NaYF4 Crystals”
Authors: Tu Datao , Zheng Wei , Chen Xueyuan
Published: December 2014

In this reply, the authors of the Communication “Breakdown of Crystallographic Site Symmetry in Lanthanide‐Doped NaYF4 Crystals” respond to the comment by Karbowiak et al., who criticized the crystal‐field (CF) analysis of Eu3+ in disordered NaYF4. The authors clarify their interpretations of the issues raised.
Direct α‐Arylation of Ethers through the Combination of Photoredox‐Mediated CH Functionalization and the Minisci Reaction
Authors: Jin Jian , MacMillan David W. C.
Published: December 2014

The direct α‐arylation of cyclic and acyclic ethers with heteroarenes has been accomplished through the design of a photoredox‐mediated CH functionalization pathway. Transiently generated α‐oxyalkyl radicals, produced from a variety of widely available ethers through hydrogen atom transfer (HAT), were coupled with a range of electron‐deficient heteroarenes in a Minisci‐type mechanism. This mild, visible‐light‐driven protocol allows direct access to medicinal pharmacophores of broad utility using feedstock substrates and a commercial photocatalyst.
Potential Mechanisms Leading to the Abnormal Lipid Profile in Patients With Rheumatoid Arthritis Versus Healthy Volunteers and Reversal by Tofacitinib
Authors: Charles‐Schoeman Christina , Fleischmann Roy , Davignon Jean , Schwartz Howard , Turner Scott M. , Beysen Carine , Milad Mark , Hellerstein Marc K. , Luo Zhen , Kaplan Irina V. , Riese Richard , Zuckerman Andrea , McInnes Iain B.
Published: December 2014

Objective

Tofacitinib is an oral JAK inhibitor for the treatment of rheumatoid arthritis (RA). Systemic inflammation is proposed to play a fundamental role in the altered lipid metabolism associated with RA; however, the underlying mechanisms are unknown. We undertook this study to compare cholesterol and lipoprotein kinetics in patients with active RA with those in matched healthy volunteers.

Methods

This was a phase I open‐label mechanism‐of‐action study. Cholesterol and lipoprotein kinetics were assessed with 13C‐cholesterol and 13C‐leucine infusions. RA patients were reevaluated after receiving oral tofacitinib 10 mg twice daily for 6 weeks.

Results

Levels of high‐density lipoprotein (HDL) cholesterol, low‐density lipoprotein (LDL) cholesterol, total cholesterol, and apolipoprotein A‐I (Apo A‐I) as well as HDL cholesterol particle number were lower in RA patients (n = 36) than in healthy volunteers (n = 33). In contrast, the cholesterol ester fractional catabolic rate was higher in RA patients, but no differences were observed in cholesterol ester transfer protein, cholesterol ester production rate, HDL‐associated Apo A‐I fractional catabolic rate, or LDL‐associated Apo B fractional catabolic rate. Following tofacitinib treatment in RA patients, the cholesterol ester fractional catabolic rate decreased and cholesterol levels increased. The decrease in cholesterol ester fractional catabolic rate correlated significantly with the increase in HDL cholesterol. Additionally, HDL cholesterol particle number increased and markers of HDL cholesterol function improved.

Conclusion

This is the first study to assess cholesterol and lipoprotein kinetics in patients with active RA and matched healthy volunteers. The data suggest that low cholesterol levels in patients with active RA may be driven by increases in cholesterol ester catabolism. Tofacitinib treatment reduced cholesterol ester catabolism, thereby increasing cholesterol levels toward those in healthy volunteers, and markers of antiatherogenic HDL function improved.
Loss of SH3 Domain–Binding Protein 2 Function Suppresses Bone Destruction in Tumor Necrosis Factor–Driven and Collagen‐Induced Arthritis in Mice
Authors: Mukai Tomoyuki , Gallant Richard , Ishida Shu , Kittaka Mizuho , Yoshitaka Teruhito , Fox David A. , Morita Yoshitaka , Nishida Keiichiro , Rottapel Robert , Ueki Yasuyoshi
Published: December 2014

Objective

SH3 domain–binding protein 2 (SH3BP2) is a signaling adapter protein that regulates the immune and skeletal systems. The present study was undertaken to investigate the role of SH3BP2 in arthritis using 2 experimental mouse models, i.e., human tumor necrosis factor α–transgenic (hTNF‐Tg) mice and mice with collagen‐induced arthritis (CIA).

Methods

First, Sh3bp2−/− and wild‐type (Sh3bp2+/+) mice were crossed with hTNF‐Tg mice. Inflammation and bone loss were examined by clinical inspection and histologic and micro−computed tomography analysis, and osteoclastogenesis was evaluated using primary bone marrow–derived macrophage colony‐stimulating factor–dependent macrophages (BMMs). Second, CIA was induced in Sh3bp2−/− and Sh3bp2+/+ mice, and the incidence and severity of arthritis were evaluated. Anti–mouse type II collagen (CII) antibody levels were measured by enzyme‐linked immunosorbent assay, and lymph node cell responses to CII were determined.

Results

SH3BP2 deficiency did not alter the severity of joint swelling but did suppress bone erosion in the hTNF‐Tg mouse model. Bone loss at the talus and tibia was prevented in Sh3bp2−/−/hTNF‐Tg mice compared to Sh3bp2+/+/hTNF‐Tg mice. RANKL‐ and TNFα‐induced osteoclastogenesis was suppressed in Sh3bp2−/− mouse BMM cultures. NF‐ATc1 nuclear localization in response to TNFα was decreased in Sh3bp2−/− mouse BMMs compared to Sh3bp2+/+ mouse BMMs. In the CIA model, SH3BP2 deficiency suppressed the incidence of arthritis and this was associated with decreased anti‐CII antibody production, while antigen‐specific T cell responses in lymph nodes were not significantly different between Sh3bp2+/+ and Sh3bp2−/− mice.

Conclusion

SH3BP2 deficiency prevents loss of bone via impaired osteoclastogenesis in the hTNF‐Tg mouse model and suppresses the induction of arthritis via decreased autoantibody production in the CIA model. Therefore, SH3BP2 could potentially be a therapeutic target in rheumatoid arthritis.