bluuebunny/crossref_metadata_2025 huggingface dataset:
Preparation of Waterborne Polyurethane‐OMt Nanocomposites and Effect of Clay on UV Degradation
Authors: Açıkalın Engin , Atıcı Oya
Published: April 2014

Waterborne polyurethane polymers (WPU) have gained importance for some decades because of their environmentally friendly characteristics due to low or zero content of solvents. Polyurethane properties can be modified by changing segmental structure or incorporating inorganic fillers into the polymer matrix. Montmorillonite (Mt) clay which is a member of smectite family is widely used in polymer clay composites as a filler. In this work, linear WPU nanocomposites were synthesized using different polyols as soft segment via acetone process which has many advantages over the prepolymer mixing process in terms of reliable reproducibility and convenience for obtaining linear polyurethanes. Sodium modified montmorillonite (NaMt) clay was used without any chemical pretreatment. WPU nanocomposites were prepared via in‐situ polymerization method by modification of sodium modified montmorillonite (NaMt) clay in polyol and following polyurethane reaction. Finally, spectroscopic, thermal, morphological characterizations and UV weathering tests carried out. As a result, different thermal and mechanical properties were observed due to different soft and hard segment content. Furthermore, increasing clay content caused lowering of resistance against UV degradation.
Non‐Linear Viscoelasticity of Filled Polymer Melts: Stress and Strain Amplification Approach
Authors: Domurath J. , Saphiannikova M. , Heinrich G.
Published: April 2014

The aim of the present study is to develop an analytical stress and strain amplification approach (SSAA) for description of non‐linear mechanical response in polymer melts containing spherical hard inclusions in a non‐dilute regime. The main presumption of this approach is that non‐aggregating filler particles reinforce a polymer matrix purely hydrodynamically. The SSAA is verified by comparison with two other approaches existing in literature, when only stress or strain is amplified, and selected experimental results.
Flow Micro‐Calorimetry and FTIR Spectroscopy Study of Interfacial Interactions in Uncoated and Coated Calcium Carbonate Filled Polyurethane Adhesives
Authors: Donate‐Robles Jessica , Liauw Christopher M. , Martín‐Martínez José Miguel
Published: April 2014

Thermoplastic polyurethane (TPU) ‐ calcium carbonate interactions were studied using flow micro‐calorimetry (FMC) and diffuse reflectance Fourier transform infrared spectroscopy (DRIFTS). FMC enabled the determination of adsorption and desorption energies; in this study a model compound approach was used to acquire insight in to the effect of calcium carbonate type and presence of stearate coating on polymer – filler interactions. It was anticipated that this data will assist in the understanding of differing responses obtained from parallel plate rheometry and viscoelastic measurements of the filled polyurethanes. Three calcium carbonates (coated and uncoated precipitated calcium carbonate, and natural ultramicronized uncoated calcium carbonate) were used. A stronger TPU‐filler interaction was shown in the uncoated precipitated calcium carbonate due to the fact that more of the surface was available for interaction.
New Silica Fillers for Polymers used in Food Packaging
Authors: Arreche Romina , Blanco Mirta , Martín‐Martínez José Miguel , Vázquez Patricia
Published: April 2014

Several nanosilicas with different degree of hydrophobicity were prepared from tetraethyl orthosilicate (TEOS) by using the sol‐gel method. Two modifiers, 3‐aminopropyl triethoxysilane (APS) and 1,1,1,3,3,3–hexamethyldisilazane (HMDS), were added during the synthesis. The nanosilicas were added to commercial biopolymer (Hexamoll Dinch, BASF) intended for packaging of apples and pears. The nanosilicas were characterized by X‐ray diffraction, transmission and scanning electron microscopies, potentiometric titration, porosity and specific surface area, and hydrophobicity/hydrophilicity by wetting tests. Colorimetry was used to assess the effect of the nanosilica in contact with apple pulp as the change in color with time was related to the efficiency of the packaging material. Addition of nanosilicas obtained with HMDS and APS increased the hydrophobicity of the biopolymer. The APS modified nanosilica showed an abrupt decrease in acidity as compared to the unmodified silica (i.e. the one prepared with only TEOS). On the other hand, the increase in HMDS maintained the spherical shape of the silica which also was maintained into the biopolymer. On the other hand, the nanosilica morphology was similar in the biopolymer materials, forming clusters or agglomerates. Finally, the brightness of the pieces of apple pulp in contact with the modified nanosilicas slightly increased with respect to the unmodified silica, and similar behavior was observed in the Hue angle.
Fracture toughness and failure assessment for particulate reinforced composites considering viscoelasticity
Authors: Kim J. H. , Ha J. S. , Seo B. H.
Published: April 2014

Fracture mechanics models which are appropriate to describe failure behavior of highly filled elastomers were discussed, and then the strip‐yield and the inherent flaw models were applied to them. In order to generate failure assessment diagrams, the two models were moderately modified, and the experiments of fracture mechanics were conducted using center cracked tension (CCT) specimens made of a highly filled elastomer applying the ASTM E399 standard. The failure assessment diagram of the modified inherent flaw model was normalized to compare with that of the modified strip‐yield model. From the comparison between two failure assessment diagrams, it was found that the failure assessment diagram of the modified inherent flaw model more conservatively assesses the failure than that of the modified strip‐yield model.
Microstructure and mechanical properties of high power diode laser (HPDL) treated cast aluminium alloys
Authors: Labisz K.
Published: April 2014

The appliance and development of modern technologies in the areas of surface engineering can be extended by laser surface treatment, especially using high power diode laser (HPDL) for remelting, feeding and/or alloying. The purpose of this work was to determine technological and technical conditions for tungsten carbide (WC) ceramic powder feeding into the surface layer of the laser treated Al–Si–Cu cast aluminium alloys with high power diode laser, as well as to investigate the microstructure and ceramic powder particle distribution in the surface layer.

Special attention was devoted to monitoring of the layer morphology of the investigated material and on the particle occurred. Light and scanning electron microscopy as well as X‐Ray diffraction were used to characterize the microstructure of the remelted zone. A wide range of laser powers was choose and implicated by different process speed rates. Also one powder in form of tungsten carbide was used for feeding with the middle particle size of 80 µm.

As the main findings there was found that, the obtained surface layer is without cracks and defects as well as has a comparably higher hardness value compared to the non remelted material. The hardness value increases according to the laser power used so that the highest power applied gives the highest hardness value in the remelted layer. Also the distribution of the tungsten carbide particles is good, but there are still possibilities for further modelling. The major purpose of this work is to study the effect of a high power diode laser melting on the cast Al–Si–Cu alloys structure to provide application possibilities for automotive and aviation industry.
Entire CAPN3 gene deletion in a patient with limb‐girdle muscular dystrophy type 2A
Authors: Jaka Oihane , Azpitarte Margarita , Paisán‐Ruiz Coro , Zulaika Miren , Casas‐Fraile Leire , Sanz Raúl , Trevisiol Nathalie , Levy Nicolas , Bartoli Marc , Krahn Martin , López de Munain Adolfo , Sáenz Amets
Published: April 2014

Limb‐girdle muscular dystrophy type 2A (LGMD2A) due to mutations in the CAPN3 gene is one of the most common of autosomal recessive limb‐girdle muscular dystrophies. We describe a patient who had a typical LGMD2A phenotype and posterior compartment involvement on MRI. Different genetic analyses were performed, including microarray analysis. There was an apparently homozygous mutation in exon 24, c.2465G>T, p.(*822Leuext62*), and a lack of correlation in the disease segregation analyses. This suggested the presence of a genomic rearrangement. In fact, a heterozygous deletion of the entire CAPN3 gene was found. This novel deletion comprised the terminal region of the GANC gene and the entire CAPN3 gene. This finding points out the need to reconsider and adapt our current strategy of molecular diagnosis in order to detect these types of genomic rearrangements that escape standard mutation screening procedures. Muscle Nerve 50: 448–453, 2014
Validation of a self‐administered instrument to measure adherence to anticholinergic drugs in women with overactive bladder
Authors: Andy Uduak U. , Harvie Heidi S. , Smith Ariana L. , Propert Kathleen J. , Bogner Hillary R. , Arya Lily A.
Published: April 2014

Aim

To validate a self‐administered instrument, the Medication Adherence Self‐Report Inventory (MASRI) for measuring adherence to anti‐cholinergic medication for overactive bladder (OAB).

Methods

Prospective study in 131 women with OAB treated with fesoterodine. Adherence was measured at 8 and 12 weeks using an interviewer administered brief medication questionnaire (BMQ) that assesses barriers to adherence (criterion standard), the MASRI, and pill count. Construct, concurrent and discriminant validity of the MASRI was assessed. We hypothesized that women who were non‐adherent as measured by the MASRI would be more likely to have a belief barrier than women who were adherent to medication.

Results

Women diagnosed as non‐adherent by the MASRI were more likely to report a belief barrier to taking medication as compared to adherent women at 8 weeks (80% vs. 38%,P < 0.001) and at 12 weeks (70% vs. 40%,P = 0.003). Significant correlations were noted between adherence rates measured by the MASRI and the BMQ at 8 weeks (r = 0.87,P < 0.001) and 12 weeks (r = 0.90,P < 0.001). Moderate correlation was noted between the adherence rate as measured by the MASRI and pill count at 8 weeks (r = 0.49,P = 0.02) but not at 12 weeks (r = 0.05,P = 0.87). The MASRI correctly identified 93% and 96% of non‐adherent women at 8 and 12 weeks, respectively. Sensitivity, specificity, and positive likelihood ratio of the MASRI for predicting non‐adherence was 91%, 82%, and 5.1 at 8 weeks and 90%, 85% and 6.1 at 12 weeks.

Conclusions

The MASRI is a valid self‐administered tool for measuring adherence to anti‐cholinergic medication in women with OAB.Neurourol. Urodynam. 34:424–428, 2015. © 2014 Wiley Periodicals, Inc.
Scurvy‐related Morbidity and Death among Christopher Columbus' Crew at La Isabela, the First European Town in the New World (1494–1498): An Assessment of the Skeletal and Historical Information
Authors: Tiesler V. , Coppa A. , Zabala P. , Cucina A.
Published: April 2014

This article explores the living conditions and specifically the possible etiologies of subperiosteal reactions among those seafarers who did not survive Christopher Columbus' second voyage to the Americas and died at La Isabela, the first permanent European settlement in the New World, which is located in the present‐day Dominican Republic. The town was founded in 1494 by Christopher Columbus (1451–1506) and occupied for only 4 years. This study analyses the macroscopic and histological evidence of the skeletal series excavated from this contact cemetery, which is presently curated at the Museo del Hombre Dominicano. Twenty of the 27 systematically scored individuals reveal subperiosteal bone accretions, and in at least 15 individuals, these accretions appear bilaterally. The morphology, distribution and healing stages of the majority of these lesions provide new, direct evidence suggesting severe adult scurvy, a condition caused by sustained vitamin C deprivation, which was common among seafarers before the 18th century. The historical context surrounding the individuals' death at the European contact settlement and the conditions and duration of Christopher Columbus' second transatlantic voyage to the New World represent key elements in the interpretation of these lesions. In this case, the evidence also corroborates the known failure of Columbus' crew to exploit the locally available foods rich in vitamin C. Scurvy probably contributed significantly to the outbreak of sickness and collective death within the first months of La Isabela's settlement, an aspect that inflects the current discussion about the degree of virulence of New World infections that decimated the European newcomers, who we conclude to have been already debilitated and exhausted by scurvy and general malnutrition. Copyright © 2014 John Wiley & Sons, Ltd.
Synthesis of polydiphenylamine with tunable size and shape via emulsion polymerization
Authors: Permpool Tharaporn , Sirivat Anuvat , Aussawasathien Darunee
Published: April 2014

The emulsion polymerization process was used in the synthesis of polydiphenylamine (PDPA) to obtain new morphologies, and the effects of surfactant types − anionic, cationic, non‐ionic − and surfactant concentrations were investigated with the roles of a template and a dopant. Scanning electron microscopy images indicated differentPDPAmorphologies depending on the surfactant type. The new morphological structures of the obtained PDPA were leaf‐like, coral‐reef‐like and red‐blood‐cell‐like, which have not been synthesized or seen before. The agglomeration of each nanoparticle is in the range of 50 nm to 500 nm depending on the surfactant type. The structure characterizations carried out by Fourier transform infrared spectroscopy, X‐ray diffractometry andUV−visible spectroscopy confirm the incorporation of surfactant in thePDPA. The electrical conductivity values of thePDPAwith surfactants are higher than that without a surfactant by four orders of magnitude and are consistent with the resultant smaller particle sizes and narrower optical band gap as calculated fromUV−visible data. To induce higher electrical conductivity ofPDPA, various dopants were used. However, the thermal stability of thePDPAis lower than that of conventional microscopicPDPA(cPDPA) due to the larger surface area ofPDPAwhich can decompose more easily. © 2014 Society of Chemical Industry
Synthesis and microphase separation of polystyrene‐b‐polylactide block copolymers aimed at preparation of ordered nanoparticle/block copolymer hybrid materials
Authors: Hou Xiaodong , Li Qiaobo , Cao Amin
Published: April 2014

A new nanoparticle/block copolymer (NP/BCP) hybrid material combining the unique properties of BCP poly(styrene)‐b‐poly(d‐lactide) (PS‐b‐PDLA) and inorganic NP quantum dots CdSe was developed. A systematic study on the microphase separation of a series of PS‐b‐PDLAs by small‐angle X‐ray scattering showed that the degree of order of the separated microdomains depended on the initial state of the BCP and the measurement temperature and can be improved through isothermal crystallization of PDLA, thermal annealing and shear field etc. Incorporating a small amount of NPs into the BCP matrix can improve the mobility of the polymer chains and thus promote self‐assembly of the BCP, which leads to hierarchically ordered structures. Excess NPs, however, cannot be completely incorporated into the PDLA domains, resulting in the phase transformation of the BCP, destruction of the ordered structure and even macroscopic phase separation due to the aggregation of NPs. An important observation is that stereocomplexation between PDLA and poly(l‐lactide) could provide a driving force to promote microphase separation of the BCP. The strategy presented in the current work has potential applications for developing highly ordered NP/BCP hybrid materials. © 2014 Society of Chemical Industry
Morphology Transformations of Platelets on Plasma Activated Surfaces
Authors: Modic Martina , Junkar Ita , Stana‐Kleinschek Karin , Kostanjšek Rok , Mozetič Miran
Published: April 2014

Improved hemocompatibility from the perspective of platelets adhesion and activation on polyethylene terephthalate surfaces has been addressed. The activation stage of platelets has been determined from their size and morphology using scanning electron microscopy (SEM). The activation of platelets on untreated polymer materials was very intensive. Polymer materials were treated with weakly ionized oxygen plasma in order to repel platelet adhesion. Already short treatment times (3s) showed significant reduction of the total number and of highly activated forms of adhered platelets. Possible mechanisms of different behaviour of blood platelets on plasma treated polymer were discussed in terms of surface adhesion and changes in morphology.
Condensed Phase Behavior in the Combustion of Ammonium Dinitramide
Authors: Fujisato Koji , Habu Hiroto , Hori Keiichi
Published: April 2014

This paper reports on the thermal and combustion behaviors of ammonium dinitramide (ADN). The thermal behavior is measured by a pressure thermogravimetric analysis (TGA) at pressures below 8 MPa. The burning rates of pure ADN and ADN/ammonium nitrate (AN) mixtures are measured in the range 0.2–12 MPa, and the burning temperature profiles are obtained using thermocouples with diameters of 5 and 25 μm. This report mainly focuses on the condensed‐phase behavior in the vicinity of a burning surface. The temperature profiles are complicated because the ADN decomposition and AN dissociation compete during the condensed phase, and the bubbles of the decomposition gas and gas‐phase flame also affect the surface temperature. AN addition helps to understand the effects of AN during the condensed phase, and it was shown that the burning temperature rises to the critical temperature of AN. Based on these experimental results, the pressure dependency of the burning rates is also discussed.
Assessment of differences in the conformational flexibility of hepatitis B virus core‐antigen and e‐antigen by hydrogen deuterium exchange‐mass spectrometry
Authors: Bereszczak Jessica Z. , Watts Norman R. , Wingfield Paul T. , Steven Alasdair C. , Heck Albert J. R.
Published: April 2014

Hepatitis B virus core‐antigen (capsid protein) and e‐antigen (an immune regulator) have almost complete sequence identity, yet the dimeric proteins (termed Cp149d and Cp(−10)149d, respectively) adopt quite distinct quaternary structures. Here we use hydrogen deuterium exchange‐mass spectrometry (HDX‐MS) to study their structural properties. We detect many regions that differ substantially in their HDX dynamics. Significantly, whilst all regions in Cp(−10)149d exchange by EX2‐type kinetics, a number of regions in Cp149d were shown to exhibit a mixture of EX2‐ and EX1‐type kinetics, hinting at conformational heterogeneity in these regions. Comparison of the HDX of the free Cp149d with that in assembled capsids (Cp149c) indicated increased resistance to exchange at the C‐terminus where the inter‐dimer contacts occur. Furthermore, evidence of mixed exchange kinetics were not observed in Cp149c, implying a reduction in flexibility upon capsid formation. Cp(−10)149d undergoes a drastic structural change when the intermolecular disulphide bridge is reduced, adopting a Cp149d‐like structure, as evidenced by the detected HDX dynamics being more consistent with Cp149d in many, albeit not all, regions. These results demonstrate the highly dynamic nature of these similar proteins. To probe the effect of these structural differences on the resulting antigenicity, we investigated binding of the antibody fragment (Fab E1) that is known to bind a conformational epitope on the four‐helix bundle. Whilst Fab E1 binds to Cp149c and Cp149d, it does not bind non‐reduced and reduced Cp(−10)149d, despite unhindered access to the epitope. These results imply a remarkable sensitivity of this epitope to its structural context.
Vaccine for human contraception targeting sperm Izumo protein and YLP12 dodecamer peptide
Authors: Naz Rajesh K.
Published: April 2014

There is an urgent need to develop a better method of contraception which is non‐steroidal and reversible to control world population explosion and unintended pregnancies. Contraceptive vaccines (CV), especially targeting sperm‐specific proteins, can provide an ideal contraceptive modality. Sperm‐specific proteins can induce an immune response in women as well as men, thus can be used for CV development in both sexes. In this article, we will review two sperm‐specific proteins, namely Izumo protein and YLP12 dodecamer peptide. Gene‐knockout studies indicate that Izumo protein is essential for sperm–egg membrane fusion. Vaccination with Izumo protein or its cDNA causes a significant reduction in fertility of female mice. The antibodies to human Izumo inhibit human sperm penetration assay. Recently, our laboratory found that a significant percentage of infertile women have antibodies to Izumo protein. The second sperm‐specific protein is YLP12, a peptide mimetic sequence present on human sperm involved in recognition and binding to the human oocyte zona pellucida. Vaccination with YLP12 or its cDNA causes long‐term, reversible contraception, without side effects, in female mice. Infertile, but not fertile, men and women have antibodies to YLP12 peptide. Our laboratory has isolated, cloned, and sequenced cDNA encoding human single chain variable fragment (scFv) antibody from infertile men which reacts with YLP12 peptide. The human YLP12 scFv antibody may provide a novel passive immunocontraceptive, the first of its kind. In conclusion, sperm‐specific Izumo protein and YLP12 peptide can provide exciting candidates for antisperm CV development.
Clinical presentation of prostate cancer in Black South Africans
Authors: Tindall Elizabeth A. , Monare L. Richard , Petersen Desiree C. , van Zyl Smit , Hardie Rae‐Anne , Segone Alpheus M. , Venter Philip A. , Bornman M.S. Riana , Hayes Vanessa M.
Published: April 2014

BACKGROUND

Compared with White Americans, Black American men are at a significant increased risk of presenting with prostate cancer (PCa) and associated mortality, suggesting a link to African‐ancestry. However, PCa status within Africa is largely unknown. We address the clinical presentation of PCa within Black South African men.

METHODS

Over 1,000 participants with or without PCa have enrolled in the Southern African Prostate Cancer Study (SAPCS). Using genome‐wide profiling we establish a unique within Africa population substructure. Adjusting for age, clinical variables were assessed, compared against Black Americans and between rural and urban localities while addressing potential socio‐demographic confounders.

RESULTS

We report a significant difference in the distribution of prostate specific antigen (PSA) levels skewed towards higher PSA levels in the PCa cases (83.0% present with a PSA ≥ 20 µg/L; median PSA = 98.8 µg/L) relative to men with no detectable PCa (18.5% present with a PSA ≥ 20 µg/L; median PSA = 9.1 µg/L). Compared with Black Americans, Black South Africans presented with significantly more aggressive disease defined by Gleason score >7 (17% and 36%, respectively) and PSA ≥ 20 µg/L (17.2% and 83.2%, respectively). We report exasperated disease aggression defined by Gleason score >7 (P = 0.0042) and poorly differentiated tumor grade (P < 0.0001) within rural versus urban localities.

CONCLUSION

Black South African men present with higher PSA levels and histopathological tumor grade compared with Black Americans, which is further escalated in men from rural localities. Our data suggests that lack of PSA testing may be contributing to an aggressive PCa disease phenotype within South African men. Prostate 74:880–891, 2014. © 2014 The Authors. Prostate published by Wiley Periodicals, Inc.
The 20th Annual Prostate Cancer Foundation Scientific Retreat report
Authors: Miyahira Andrea K. , Simons Jonathan W. , Soule Howard R.
Published: April 2014

The 20th Annual Prostate Cancer Foundation (PCF) Scientific Retreat was held from October 24 to 26, 2013, in National Harbor, Maryland. This event is held annually for the purpose of convening a diverse group of leading experimental and clinical researchers from academia, industry, and government to present and discuss critical and emerging topics relevant to prostate cancer (PCa) biology, and the diagnosis, prognosis, and treatment of PCa patients, with a focus on results that will lend to treatments for the most life‐threatening stages of this disease. The themes that were highlighted at this year's event included: (i) mechanisms of PCa initiation and progression: cellular origins, neurons and neuroendocrine PCa, long non‐coding RNAs, epigenetics, tumor cell metabolism, tumor–immune interactions, and novel molecular mechanisms; (ii) advancements in precision medicine strategies and predictive biomarkers of progression, survival, and drug sensitivities, including the analysis of circulating tumor cells and cell‐free tumor DNA—new methods for liquid biopsies; (iii) new treatments including epigenomic therapy and immunotherapy, discovery of new treatment targets, and defining and targeting mechanisms of resistance to androgen‐axis therapeutics; and (iv) new experimental and clinical epidemiology methods and techniques, including PCa population studies using patho‐epidemiology. Prostate 74:811–819, 2014. © 2014 Wiley Periodicals, Inc.
Assessment of fully automated antibody homology modeling protocols in molecular operating environment
Authors: Maier Johannes K. X. , Labute Paul
Published: April 2014

The success of antibody‐based drugs has led to an increased demand for predictive computational tools to assist antibody engineering efforts surrounding the six hypervariable loop regions making up the antigen binding site. Accurate computational modeling of isolated protein loop regions can be quite difficult; consequently, modeling an antigen binding site that includes six loops is particularly challenging. In this work, we present a method for automatic modeling of the FV region of an immunoglobulin based upon the use of a precompiled antibody x‐ray structure database, which serves as a source of framework and hypervariable region structural templates that are grafted together. We applied this method (on common desktop hardware) to the Second Antibody Modeling Assessment (AMA‐II) target structures as well as an experimental specialized CDR‐H3 loop modeling method. The results of the computational structure predictions will be presented and discussed. Proteins 2014; 82:1599–1610. © 2014 The Authors. Proteins published by Wiley Periodicals, Inc.
CoFeCu electroplated nanowire arrays: Role of composition and annealing on structure and magnetic properties
Authors: Bran Cristina , Palmero Ester M. , del Real Rafael P. , Vazquez Manuel
Published: April 2014

CoxFe100−x and CoxFe95−xCu5, with 30 < x < 90, arrays of nanowire, around 20 nm in diameter and about 5 μm long, have been prepared by electrodeposition filling the self‐assembled nanopores of anodic alumina templates. These samples were later thermally annealed for 2 h in the range of temperatures up to 600 °C. Crystalline anisotropy was confirmed to exhibit bcc cubic structure with [110] texture in as‐prepared state. First structural changes are observed after annealing at 450 °C when a refinement of such cubic phase is observed. Annealing at higher temperatures promotes the appearance of Co and Fe oxides. Small addition of Cu to CoFe alloys induces only limited variations in the magnetic properties for as‐prepared samples. Nevertheless, the presence of small Cu content promotes a significant magnetic hardening in comparison with the effect observed in CoFe nanowires. From the temperature dependence of magnetic properties in as‐prepared and annealed samples we conclude a complex contribution of various anisotropy energy terms coming from the annealing and from the presence of Cu.

The presence of Cu in small amount induces significant changes in the magnetic properties of annealed CoFeCu nanowires.
The ICON (ICOsahedral Non‐hydrostatic) modelling framework of DWD and MPI‐M: Description of the non‐hydrostatic dynamical core
Authors: Zängl Günther , Reinert Daniel , Rípodas Pilar , Baldauf Michael
Published: April 2014

This article describes the non‐hydrostatic dynamical core developed for the ICOsahedral Non‐hydrostatic (ICON) modelling framework. ICON is a joint project of the German Weather Service (DWD) and the Max Planck Institute for Meteorology (MPI‐M), targeting a unified modelling system for global numerical weather prediction (NWP) and climate modelling. Compared with the existing models at both institutions, the main achievements of ICON are exact local mass conservation, mass‐consistent tracer transport, a flexible grid nesting capability and the use of non‐hydrostatic equations on global domains. The dynamical core is formulated on an icosahedral‐triangular Arakawa C grid. Achieving mass conservation is facilitated by a flux‐form continuity equation with density as the prognostic variable. Time integration is performed with a two‐time‐level predictor–corrector scheme that is fully explicit, except for the terms describing vertical sound‐wave propagation. To achieve competitive computational efficiency, time splitting is applied between the dynamical core on the one hand and tracer advection, physics parametrizations and horizontal diffusion on the other hand. A sequence of tests with varying complexity indicates that the ICON dynamical core combines high numerical stability over steep mountain slopes with good accuracy and reasonably low diffusivity. Preliminary NWP test suites initialized with interpolated analysis data reveal that the ICON modelling system already achieves better skill scores than its predecessor at DWD, the operational hydrostatic Global Model Europe (GME), and at the same time requires significantly fewer computational resources.
Semiconducting Carbon Nanotube Aerogel Bulk Heterojunction Solar Cells
Authors: Ye Yumin , Bindl Dominick J. , Jacobberger Robert M. , Wu Meng‐Yin , Roy Susmit Singha , Arnold Michael S.
Published: April 2014

Using a novel two‐step fabrication scheme, we create highly semiconducting‐enriched single‐walled carbon nanotube (sSWNT) bulk heterojunctions (BHJs) by first creating highly porous interconnected sSWNT aerogels (sSWNT‐AEROs), followed by back‐filling the pores with [6,6]‐phenyl‐C71‐butyric acid methyl ester (PC71BM). We demonstrate sSWNT‐AERO structures with density as low as 2.5 mg cm−3, porosity as high as 99.8%, and diameter of sSWNT fibers ≤10 nm. Upon spin coating with PC71BM, the resulting sSWNT‐AERO‐PC71BM nanocomposites exhibit highly quenched sSWNT photoluminescence, which is attributed to the large interfacial area between the sSWNT and PC71BM phases, and an appropriate sSWNT fiber diameter that matches the inter‐sSWNT exciton migration length. Employing the sSWNT‐AERO‐PC71BM BHJ structure, we report optimized solar cells with a power conversion efficiency of 1.7%, which is exceptional among polymer‐like solar cells in which sSWNTs are designed to replace either the polymer or fullerene component. A fairly balanced photocurrent is achieved with 36% peak external quantum efficiency (EQE) in the visible and 19% peak EQE in the near‐infrared where sSWNTs serve as electron donors and photoabsorbers. Our results prove the effectiveness of this new method in controlling the sSWNT morphology in BHJ structures, suggesting a promising route towards highly efficient sSWNT photoabsorbing solar cells.
Against Fragmentation
Authors: Norby Aaron ,   Philosophy Documentation Center
Published: April 2014

I criticize the idea that theories of ‘fragmented’ or ‘compartmentalized’ belief (as found in, e.g., Lewis 1982, Egan 2008) can help to account for the puzzling phenomena they are often taken to account for. After introducing fragmentationalism and a paradigm case that purportedly motivates it, I criticize the view primarily on the grounds that themodels and explanations it offers are at best trivial—as witnessed by examples of over-generation—and should be seen as merely re-describing in figurative terms the phenomena it is designed to account for. I also point out that fragments, as used in these theories, are not likely to be psychologically real in any robust sense and so cannot be appealed to on such grounds.
Existence result for a fluid structure interaction problem with friction type slip boundary condition
Authors: Baffico L. , Sassi T.
Published: April 2014

We study the stationary interaction between a 2D viscous fluid, governed by the Stokes equation, and a rigid structure that can move following rigid displacements. The displacements of the structure are determined using an algebraic equation. A slip boundary condition of friction type is used on the fluid–solid interface. An existence result is proved and numerical tests are presented.
Redefining Neighborhoods Using Common Destinations: Social Characteristics of Activity Spaces and Home Census Tracts Compared
Authors: Jones Malia , Pebley Anne R.
Published: April 2014

Research on neighborhood effects has focused largely on residential neighborhoods, but people are exposed to many other places in the course of their daily lives—at school, at work, when shopping, and so on. Thus, studies of residential neighborhoods consider only a subset of the social-spatial environment affecting individuals. In this article, we examine the characteristics of adults’ “activity spaces”—spaces defined by locations that individuals visit regularly—in Los Angeles County, California. Using geographic information system (GIS) methods, we define activity spaces in two ways and estimate their socioeconomic characteristics. Our research has two goals. First, we determine whether residential neighborhoods represent the social conditions to which adults are exposed in the course of their regular activities. Second, we evaluate whether particular groups are exposed to a broader or narrower range of social contexts in the course of their daily activities. We find that activity spaces are substantially more heterogeneous in terms of key social characteristics, compared to residential neighborhoods. However, the characteristics of both home neighborhoods and activity spaces are closely associated with individual characteristics. Our results suggest that most people experience substantial segregation across the range of spaces in their daily lives, not just at home.
RISK ANALYSIS OF ANNUITY CONVERSION OPTIONS IN A STOCHASTIC MORTALITY ENVIRONMENT
Authors: Kling Alexander , Ruß Jochen , Schilling Katja
Published: April 2014

While extensive literature exists on the valuation and risk management of financial guarantees embedded in insurance contracts, both the corresponding longevity guarantees and interactions between financial and longevity guarantees are often ignored. The present paper provides a framework for a joint analysis of financial and longevity guarantees, and applies this framework to different annuity conversion options in deferred unit-linked annuities. In particular, we analyze and compare different versions of so-called guaranteed annuity options and guaranteed minimum income benefits with respect to the value of the option and the resulting risk for the insurer. Furthermore, we examine whether and to what extent an insurance company is able to reduce the risk by typical risk management strategies. The analysis is based on a combined stochastic model for both financial market and future survival probabilities. We show that different annuity conversion options have significantly different option values, and that different risk management strategies lead to a significantly different risk for the insurance company.
Ali A. Mazrui, the Postcolonial Theorist
Authors: Adem Seifudein
Published: April 2014

The primary goal of this article is to examine why Ali A. Mazrui is a relatively obscure figure in postcolonial theory despite the outstanding contributions he has made to it. It argues that the explanation can be found in the nature of postcolonial theory itself, and in Mazrui’s perceived ideology and cultural identity. The article, then, introduces Mazrui’s theory of the “triple heritage,” his most innovative and, possibly, most enduring contribution to scholarship. It also explains the specificity of Mazrui’s brand of postcolonial theory as well as the complexity and breadth of his thinking about Africa in general.
Julius Nyerere, Ujamaa, and Political Morality in Contemporary Tanzania
Authors: Fouéré Marie-Aude
Published: April 2014

Since the 2000s, Tanzania has witnessed the return in the public sphere of a reconfigured version of Ujamaa as a set of moral principles embodied in the figure of the first president of Tanzania, Julius Kambarage Nyerere. The persisting traces of Nyerere and Ujamaa are not so evident in actual political practices or economic policies, but rather in collective debates about politics and morality—in short, in contemporary imaginaries of the nation. Contributing to a long-standing discussion of the moral stature of Tanzania’s “father of the nation,” the article explores how and why a shared historical memory of Nyerere is being built or contested to define, mediate, and construct Tanzanian conceptions of morality, belonging, and citizenship in the polis today.
Radio Call-In Shows on Intimate Issues in Benin: “Crossroads of Sentiments”
Authors: Grätz Tilo
Published: April 2014

The article focuses on the growing prevalence of radio call-in shows in the Republic of Benin that discuss topics such as sexuality and intimacy that are taboo in other settings. The popularity of this emerging format exemplifies current processes of appropriation of electronic media in West Africa, including its impact on contemporary public communication. The article argues that the current public prominence of these programs corresponds to considerable shifts in the media landscape that are enabled by a variety of factors, including an increasing expertise among presenters and technicians and the influence of mobile phones.
The Politics of Decentralization in Ghana’s Fourth Republic
Authors: Debrah Emmanuel
Published: April 2014

This article assesses how the District Assemblies in Ghana’s Fourth Republic have exercised political, administrative, and fiscal powers transferred to them by the central government. It notes that the creation of the assemblies has promoted popular participation and boosted the autonomy of front-line officials in terms of decision-making and the allocation of financial resources at the local level. However, the central government retains the authority to appoint the District Chief Executive and 30 percent of the assembly members. Local governments experience delays in the transfer of funds, an inability to absorb civil servants of decentralized departments into the local culture, and a lack of capacity to raise revenue for development. The article argues that local election of the District Chief Executive and increased allocation of funds to the rural districts would attract entrepreneurs and skilled civil servants who would be able to implement effective decentralization.
WELCOMING THE ‘FON OF FONS’: ANGLOPHONE ELITES AND THE POLITICS OF HOSTING CAMEROON'S HEAD OF STATE
Authors: Orock Rogers Tabe Egbe
Published: April 2014

This article draws on a political ethnography of the hosting of state ceremonies to engage with erstwhile theoretical accounts of African politics as highly patrimonial and built on a social complicity between African rulers and their citizens. The article examines the patrimonial relationship between Cameroon's head of state, Paul Biya, and political elites of local ethno-regional communities who support the president within the framework of the Cameroon People's Democratic Movement (CPDM) in Anglophone Cameroon. It approaches such elite politics of hosting as part of the vast cultural repertoire of patrimonial domination that emphasizes a spectacularization of proximity and intimacy between the head of state and his coterie of supporting elites as the latter seek development resources for their local and regional communities in exchange for their political support. To account for hosting as a practice of patrimonial elite politics, the article demonstrates the complex logics and pragmatics of ethnic and regional competition as well as the deployment of symbolic idioms of hierarchical relations, mutuality and interdependence in the cultural performance and legitimation of Biya's patrimonial domination of Cameroon.
RETHINKING POLITICAL RHETORIC AND AUTHORITY DURING RWANDA'S FIRST AND SECOND REPUBLICS
Authors: Desrosiers Marie-Eve
Published: April 2014

Drawing on rarely analysed primary sources obtained during multi-site archival research, this article examines and proposes to reassesses the political rhetoric deployed in pre-genocide Rwanda (First and Second Republics). The article contends that the First and Second Republics' rhetoric was not as ethnocentric as often contended. It argues instead that this rhetoric, cautious and moderate, should be understood as part of regime resilience strategies. Born of questionable origins, the two regimes faced recurrent instability and only imposed their authority questionably on segments of the Rwandan population. Unlike ethnocentric rhetoric calling upon limited ethnic affinities, moderate rhetoric was meant to ‘persuade’ and ‘pre-empt’, in other words extend support for regimes that were uncertain of their grounding.
I TOOK AN ALLEGIANCE TO SECRECY: COMPLEXITIES OF CONDUCTING ETHNOGRAPHIC RESEARCH AT HOME
Authors: Setlhabi Keletso Gaone
Published: April 2014

Anthropological research was traditionally conducted by foreign researchers in ‘exotic’ places. However, the trend changed over the years due to various reasons such as less funding for research abroad, resistance from new independent states, and the realization that, after all, the ‘exotic’ could be found even ‘at home’. The research dynamics changed further when those who were studied earlier began to study their own. This paper is a reflection of my participatory observation in the 2009bojale(girls’ initiation) revival ceremony of Bakgatla-baga-Kgafela in Botswana. I enteredbojalewith dual roles of initiate and participant observer for my research. My ethnographic research was among my own and I was expected to adhere to the ceremony's rules in the same way as the other initiates. The discussion reflects on my dual identity experiences and relationships during initiation in order to interrogate ethnography among one's own culture. I conclude that, even though being ‘at home’ has advantages such as less travelling requirements and easy rapport, it is a complex process when it involves sacred ceremonies such asbojalebecause of the societal obligations such as adherence to secrecy that the researcher is bound by during and after the research.
Nation-State Science: Lappology and Sweden's Ethnoracial Purity
Authors: Mattson Greggor
Published: April 2014

This paper introduces the concept of “nation-state science” to describe the scientific work of ethnoracial classification that made possible the ideal of the homogenous nation-state. Swedish scientists implicitly defined their nation for Continental Europeans when they explicitly created knowledge about the “Lapps” (today's Sámi/Saami). Nation was coupled to state through such ethnoracial categories, the content of which were redefined as Sweden's geopolitical power rose and fell. These shifts sparked methodological innovations to redefine the Lapp, making it a durable category whose content was plastic enough to survive paradigm shifts in political and scientific thought. Idiosyncratic Swedish concerns thus became universalized through the scientific diffusion of empirical knowledge about Lapps and generalizable anthropometric techniques to distinguish among populations. What Sweden lost during the nineteenth century in terms of geopolitical power, it gained in terms of biopower: the knowledge and control of internal populations made possible by its widely adopted anthropometric innovations. Nation-state science helps unpack the interrelationships between state-building, nation-making, and scientific labor.
Ghosts in the Academy: Historians and Historical Consciousness in the Making of Modern Uganda
Authors: Reid Richard J.
Published: April 2014

The public and professional significance of precolonial History as a discipline has declined markedly across much of sub-Saharan Africa over the last forty years: History has been both demonized—depicted as deeply dangerous and the source of savagery and instability—and portrayed as irrelevant when set alongside the needs for economic modernization and “development.” This paper explores this trend in the context of Uganda, with a particular focus on the kingdom of Buganda, chosen for its particularly rich oral and literary heritage and the thematic opportunities offered by its complex and troubled twentieth century. The paper aims to explore how “the past”—with a focus on the precolonial era—has been understood there in several distinct periods. These include the era of imperial partition and the formation of the Uganda Protectorate between the 1880s and the 1910s; competition for political space within colonial society to the 1950s; decolonization and the struggle to create new nationhood in the mid-twentieth century; and political crises and partial recovery since the 1970s. Ultimately, the paper seeks to assess the role of History in a modern African society vis-à-vis the developmental agendas and notions of economic growth against which African “progress” and prospects for “stability” are currently measured.
Constructing Colonial Legality in Russian Central Asia: On Guardianship
Authors: Sartori Paolo
Published: April 2014

The history of Islamic law in Russian Central Asia defies many of the categorizations offered by both global and Russian imperial history. Recent studies of law in the age of colonialism have concluded that the attainment of legal hegemony in the colonies was consequent upon the initiative of indigenes that strategically manipulated jurisdictions; as colonial subjects increasingly involved the state in their private conflicts, they effectively pushed their masters to consolidate the institutional arrangements through which the state dispensed justice. Historians of the Russian Empire have reached a diametrically different conclusion: under tsarist rule, they argue, Muslims continued to access the services of the “native courts,” which remained mostly untouched following Russia's southeastward expansion. As the empire promoted a policy of differentiated jurisprudence, Russians effectively safeguarded the integrity of Islamic law. I argue that both of the aforementioned approaches are confined to the level of institutional history, and thus fail to consider that the creation of colonial hegemony rested on ways in which colonial subjects understood law and viewed themselves as legal subjects. I show that Russians, from the outset of their rule in Central Asia, initiated Muslims into colonial forms of legality by overcoming the jurisdictional separation they had themselves put in place. In allowing the local population to file their grievances with the military bureaucracy, the Russians effectively pushed Central Asians to reify colonial notions of justice, and thereby distance themselves from the tradition of Islamic legal practices.