bluuebunny/crossref_metadata_2025 huggingface dataset:
Ultrastructural characteristics of 5BrdU labeling retention cells including stem cells of regenerating feathers in chicken
Authors: Alibardi Lorenzo , Wu Ping , Chuong Cheng‐Ming
Published: February 2014

Feathers regenerate from stem cells localized in a region of the follicle indicated as the bulge of the collar. Stem cells are slow cycling cells and some of these cells can be identified after labeling experiments using 5‐bromo‐deoxyuridine to detect label retaining cells (5BrdU LRCs). The present electron microscopic analysis of 5BrdU LRCs has described the ultrastructural characteristics of small cells present in the bulge region of the follicle in regenerating feathers of chickens that include stem cells. Labeled feather stem cells are smaller than 10 μm in average diameter, possess large nuclei with high nuclear/cytoplasmic ratio, and contain evenly distributed ribosomes, sparse bundles of intermediate filaments, scarce or no endoplasmic reticulum, and few mitochondria. The nuclei are mainly euchromatic with a variable amount of heterochromatin clumps and the nucleoli show developed granular and fibrillar components. These features indicate that feather stem cells are transcriptionally active cells for ribosomal and proteins synthesis. The cell surface of feather stem cells often shows small and irregular folds resembling microvilli in contact with the surrounding cells. The latter characteristics may be related to the exchange of molecules and/or with the migration of stem cells among other epithelial cells of the collar epithelium. J. Morphol. 275:768–774, 2014. © 2014 Wiley Periodicals, Inc.
Nutrient limitation of alpine plants: Implications from leaf N : P stoichiometry and leaf δ15N
Authors: Xu Xingliang , Wanek Wolfgang , Zhou Caiping , Richter Andreas , Song Minghua , Cao Guangmin , Ouyang Hua , Kuzyakov Yakov
Published: February 2014

Nitrogen (N) deposition can affect grassland ecosystems by altering biomass production, plant species composition and abundance. Therefore, a better understanding of the response of dominant plant species to N input is a prerequisite for accurate prediction of future changes and interactions within plant communities. We evaluated the response of seven dominant plant species on the Tibetan Plateau to N input at two levels: individual species and plant functional group. This was achieved by assessing leaf N : P stoichiometry, leaf δ15N and biomass production for the plant functional groups. Seven dominant plant species—three legumes, two forbs, one grass, one sedge—were analyzed for N, P, and δ15N 2 years after fertilization with one of the three N forms: NO$ _3^- $, NH$ _4^+ $, or NH4NO3 at four application rates (0, 7.5, 30, and 150 kg N ha–1 y–1). On the basis of biomass production and leaf N : P ratios, we concluded that grasses were limited by available N or co‐limited by available P. Unlike for grasses, leaf N : P and biomass production were not suitable indicators of N limitation for legumes and forbs in alpine meadows. The poor performance of legumes under high N fertilization was mainly due to strong competition with grasses. The total above‐ground biomass was not increased by N fertilization. However, species composition shifted to more productive grasses. A significant negative correlation between leaf N : P and leaf δ15N indicated that the two forbs Gentiana straminea and Saussurea superba switched from N deficiency to P limitation (e.g., N excess) due to N fertilization. These findings imply that alpine meadows will be more dominated by grasses under increased atmospheric N deposition.
Effects of tillage and application of cattle slurry on carbon pools and aggregate distribution in temperate grassland soils
Authors: Linsler Deborah , Geisseler Daniel , Loges Ralf , Taube Friedhelm , Ludwig Bernard
Published: February 2014

The objective was to study the effects of tillage and cattle slurry application on organic C dynamics in grassland soils. Treatments included long‐term grassland and reinstalled grassland (after tillage and winter wheat cropping) with and without cattle slurry application (240 kg N ha–1 y–1). A period of 4 y slurry application sufficed to increase microbial activity 1.6‐fold in surface soil (0–10 cm). Tillage affected aggregate distribution and basal respiration in the surface soil.
Modeling of Network Formation in Reversible Addition‐Fragmentation Transfer (RAFT) Copolymerization of Vinyl/Divinyl Monomers Using a Multifunctional Polymer Molecule Approach
Authors: Hernández‐Ortiz Julio César , Vivaldo‐Lima Eduardo , Dubé Marc Arnold , Penlidis Alexander
Published: February 2014

A mathematical model for the kinetics of copolymerization with crosslinking of vinyl/divinyl monomers in the presence of RAFT controllers is developed. A reaction scheme considering multifunctional polymer molecules, which results in a multidimensional problem, is proposed. Molecular weight development during the pre‐gelation period was calculated using the method of moments. Flory–Stockmayer's theory is used for the post‐gelation period. The case of RAFT homopolymerization is also studied, as an example of model reduction, with identical results as those obtained with an existing model based on a simplifying premise. Good agreement between predicted profiles, our own experimental data, and data from other groups is obtained in most of the analyzed cases despite the occasional use of certain simplifying assumptions.
Robust 4D flow denoising using divergence‐free wavelet transform
Authors: Ong Frank , Uecker Martin , Tariq Umar , Hsiao Albert , Alley Marcus T , Vasanawala Shreyas S. , Lustig Michael
Published: February 2014

Purpose

To investigate four‐dimensional flow denoising using the divergence‐free wavelet (DFW) transform and compare its performance with existing techniques.

Theory and Methods

DFW is a vector‐wavelet that provides a sparse representation of flow in a generally divergence‐free field and can be used to enforce “soft” divergence‐free conditions when discretization and partial voluming result in numerical nondivergence‐free components. Efficient denoising is achieved by appropriate shrinkage of divergence‐free wavelet and nondivergence‐free coefficients. SureShrink and cycle spinning are investigated to further improve denoising performance.

Results

DFW denoising was compared with existing methods on simulated and phantom data and was shown to yield better noise reduction overall while being robust to segmentation errors. The processing was applied to in vivo data and was demonstrated to improve visualization while preserving quantifications of flow data.

Conclusion

DFW denoising of four‐dimensional flow data was shown to reduce noise levels in flow data both quantitatively and visually. Magn Reson Med 73:828–842, 2015. © 2014 Wiley Periodicals, Inc.
The modified rankin scale to assess disability in myasthenia gravis: Comparing with other tools
Authors: Farrugia Maria E. , Carmichael Caroline , Cupka Bryan J. , Warder Judy , Brennan Kathryn M. , Burns Ted M.
Published: February 2014

Introduction: We explored the modified Rankin scale (mRS) as a tool to quantitate disability in myasthenia gravis (MG). Our aim was to correlate patients' perception of their disability with that of the care provider and determine its relationship with other MG‐related scores. Methods: We evaluated 107 MG patients at 2 neurological centers. Patients were assessed over the telephone before and after clinic visits using the 15‐item Myasthenia Gravis Quality‐of‐Life index (MG‐QOL15) and mRS. At the clinic, patients were assessed using the MG‐QOL15, MG Composite (MGC), and mRS. Results: The MG‐QOL15 correlated with the MGC, mRS, and assessors' scores of patients. Assessors' perception of disease burden was in line with that of the patients' scoring. MG‐QOL15 scores obtained over the telephone were consistent with those obtained in the clinic. Scores were generally higher in patients receiving steroids at >5 mg/day and in those receiving or seeking benefits. Conclusion: The MG‐QOL15 and mRS are useful for estimating disability in MG. Muscle Nerve 50: 501–507, 2014
Dispersion analysis of plane wave discontinuous Galerkin methods
Authors: Gittelson Claude J. , Hiptmair Ralf
Published: February 2014

The plane wave DG (PWDG) method for the Helmholtz equation was introduced and analyzed in [GITTELSON, C., HIPTMAIR, R., AND PERUGIA, I. Plane wave discontinuous Galerkin methods: analysis of the h‐version. Math. Model. Numer. Anal. 43 (2009), 297–331] as a generalization of the so‐called ultra‐weak variational formulation, see [O. CESSENAT AND B. DESPRéS, Application of an ultra weak variational formulation of elliptic PDEs to the two‐dimensional Helmholtz equation, SIAM J. Numer. Anal., 35 (1998), pp. 255–299]. The method relies on Trefftz‐type local trial spaces spanned by plane waves of different directions, and links cells of the mesh through numerical fluxes in the spirit of DG methods.

We conduct a partly empirical dispersion analysis of the method in a discrete translation‐invariant setting by studying the mismatch of wave numbers of discrete and continuous plane waves traveling in the same direction. We find agreement of the wave numbers for directions represented in the local trial spaces. For other directions, the PWDG methods turn out to incur both phase and amplitude errors. This manifests itself as a pollution effect haunting the h‐version of the method. Our dispersion analysis allows a quantitative prediction of the strength of this effect and its dependence on the wave number and number of plane waves. Copyright © 2014 John Wiley & Sons, Ltd.
The incorporation of gradient damage models in shell elements
Authors: Hosseini Saman , Remmers Joris J.C. , de Borst René
Published: February 2014

An approach is proposed to incorporate gradient‐enhanced damage models in shell elements. The approach is elaborated for a solid‐like shell element, which is advantageous because of the availability of nodes at the top and bottom shell surfaces, and the presence of a three‐dimensional strain state. Some simple examples are given to demonstrate the versatility and the convergence of the method. Copyright © 2014 John Wiley & Sons, Ltd.
Synthesis and characterization of rutile titanium dioxide/polyacrylate nanocomposites for applications in ultraviolet light‐shielding materials
Authors: Man Yake , Mu Luye , Wang Yun , Lin Shaohui , Rempel Garry L. , Pan Qinmin
Published: February 2014

Rutile titanium dioxide (TiO2)/poly(methyl methacrylate‐acrylic acid‐butyl acrylate) nanocomposites were synthesized via seeded emulsion polymerization and characterized by Fourier transmission infrared, dynamic light scattering, X‐ray diffraction, ultraviolet–visible (UV–vis) spectroscopy, scanning electron microscopy, transmission electron microscopy, and thermogravimetric analysis to study their UV‐shielding property. The effects of the nanoseed types, surfactant concentrations, and functional monomer amounts on the polymerization conversion, particle size, emulsion stability, and morphologies of the resulting nanocomposites were investigated. The dependence of UV‐shielding performance on the nanoparticle content and dispersion was also explored. The optimized results are obtained with 2 wt% of TiO2nanoparticles addition, and the effectiveness of UV shielding is significantly increased by using the synthesized rutile nano‐TiO2/polyacrylates, for which the nanocomposite coating with a thickness of 200 μm could block up to 99.99% of UV light (≤350 nm) as confirmed by UV–vis spectrometry. POLYM. COMPOS., 36:8–16, 2015. © 2014 Society of Plastics Engineers
Soft nanoparticles assembled from linear poly(ethylene glycol) and linear brush polydimethylsiloxane diblock copolymers
Authors: Halim Andri , Reid Timothy D. , Ren Jing M. , Fu Qiang , Gurr Paul A. , Blencowe Anton , Kentish Sandra E. , Qiao Greg G.
Published: February 2014

A series of novel amphiphilic diblock copolymers composed of hydrophilic linear poly(ethylene glycol) (PEG) and linear brush hydrophobic polydimethylsiloxane (PDMS) were synthesized. Three different molecular weights of monomethyl ether PEG were initially functionalized with 2‐bromoisobutyryl bromide to afford macroinitiators suitable for atom‐transfer radical polymerization. The macroinitiators were characterized by gel permeation chromatography, 1H and 13C nuclear magnetic resonance spectroscopic analysis and matrix‐assisted laser desorption ionization time‐of‐flight mass spectroscopy. The three different molecular weight macroinitiators were then chain extended with monomethacryloxypropyl‐terminated PDMS and photoactive 2‐(methylacyloyloxy)ethyl anthracene‐9‐carboxylate in different molar ratios to afford a series of photoresponsive amphiphilic diblock copolymers with high conversions. Self‐assembly of these linear–linear brush diblock copolymers in N,N‐dimethylformamide afforded nanoparticles with hydrodynamic diameters (dH) ranging from 41 to 268 nm, as determined by dynamic light scattering analysis. Crosslinking and stabilization of the nanoparticles was achieved via [4+4] photodimerization of the anthracene moieties upon exposure to UV radiation at 365 nm with the reverse reaction studied at a wavelength of 254 nm. Transmission electron microscopy revealed that the self‐assembled nanoparticles and their crosslinked derivatives had spherical morphologies. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 1251–1262
Hydrophobic Zeolite‐Filled Polymeric Films with High Ethylene Permselectivity for Fresh Produce Packaging Applications
Authors: Fuongfuchat Asira , Sirikittikul Doungporn , Booncharoen Warintorn , Raksa Phatchareeya , Ritvirulh Chonlada , Sooknoi Tawan
Published: February 2014

Gas permselective plastic films have been in a great deal of attention in the area of modified atmosphere packaging of fresh produces. Such films must allow transport of the respiring gases, i.e. oxygen and carbon dioxide, in a controlled manner and, moreover, should efficiently remove ethylene gas. Therefore, the development of highly permeable films with high ethylene permselectivity, i.e. high in both permeability and selectivity, was carried out. The concept of ‘mixed matrix membrane’, by which enhanced gas permselectivity can be obtained by incorporation of zeolite particles into the polymeric film, was applied. Fine particles of hydrophobic zeolites, i.e. zeolite beta and ZSM‐5, and the surface‐modified zeolites were used in this study. The films with uniform distribution of zeolite particles (10% w/w) in 70LDPE/30SEBS (styrene‐b‐(ethylene‐ran‐butylene)‐b‐styrene block copolymer) matrix can be prepared by blow film extrusion. Significantly high ethylene permselectivity, i.e. ethylene permeability of 1.78–2.67 × 103 cm3 ∙ mm/m2 ∙ day ∙ atm and ethylene/O2 selectivity of 4.67–8.26, was obtained from the films containing octyl‐modified and phenyl‐modified zeolites. Particular enhancement was observed on the films containing phenyl‐modified zeolites. Crystallinity of polyethylene, transition temperatures and decomposition temperature were, however, indifferent among the studied films. Nevertheless, elongation at break and toughness of the films containing surface‐modified zeolites were superior. Particle–polymer interface could thus be improved. Copyright © 2014 John Wiley & Sons, Ltd.
Migration Processes of Metal Elements from Carbon Steel Cylinders to Food Gases
Authors: Tassi Franco , Capecchiacci Francesco , Vaselli Orlando
Published: February 2014

This study is aimed to provide a protocol for sampling and analysis of metal elements migrating from carbon steel cylinders, used for gas storage and distribution, to food gases, i.e. those gases, such as CO2, N2 and O2, employed by food and beverage industries. The concentrations of 23 selected elements, analysed by inductively coupled plasma mass spectrometry, in the three food gases collected from steel cylinders after a storage period of 50 days, were re‐calculated considering (a) the initial concentrations (i.e. the concentrations of these elements in food gases before being packaged in carbon steel cylinders) and (b) a migration process of 5 years that proceeds in time following a linear trend.

Computed data were compared with the limit concentrations for mineral waters (CEE/CEEA/CE no. 83, 03‐11‐1998; D.Lgs no. 3, 2001; D.M. 29‐12‐2003), considering that the quantity of CO2 commonly added to 1 L of mineral water is 5 g. Although no reference values indicating the concentration limits of metal contaminants in food gases are currently promulgated, the results of this comparison have evidenced that the highest concentrations of the most abundant elements among those selected for the test, i.e. Al, Cd, Cr, Cu, Fe, Mn, Ni and Pb, are up to 4 orders of magnitude lower that the previously cited limits. This suggests that the effects of migration of contaminants from carbon steel cylinders do not have a significant influence on the quality of food gases, independently on the type of food gas and carbon steel composition. Copyright © 2014 John Wiley & Sons, Ltd.
What matters in college for retaining aspiring scientists and engineers from underrepresented racial groups
Authors: Chang Mitchell J. , Sharkness Jessica , Hurtado Sylvia , Newman Christopher B.
Published: February 2014

This longitudinal study examined factors that contribute to the persistence of underrepresented racial minority (URM) undergraduates in STEM fields. The primary source of data came from the Cooperative Institutional Research Program's 2004The Freshman Survey(TFS) and 2008College Senior Survey(CSS). The sample included 3,670 students at 217 institutions who indicated on the TFS that they intended to major in a STEM field, 1,634 of whom were underrepresented minority (URM) students. Findings indicate that Black and Latino undergraduates were significantly less likely to persist in STEM majors than were their White and Asian American counterparts. Background characteristics and college experiences moderated this race effect, suggesting both that pre‐college factors may explain some of the observed racial disparities and that individual institutions can take more concrete actions to improve science achievement. Findings from the follow‐up analysis of the sample of URMs suggest that institutions can improve URM STEM persistence by increasing the likelihood that those students will engage in key academic experiences: studying frequently with others, participating in undergraduate research, and involvement in academic clubs or organizations. © 2014 Wiley Periodicals, Inc. J Res Sci Teach 51: 555–580, 2014
Large‐eddy simulations of the Lillgrund wind farm
Authors: Nilsson Karl , Ivanell Stefan , Hansen Kurt S. , Mikkelsen Robert , Sørensen Jens N. , Breton Simon‐Philippe , Henningson Dan
Published: February 2014

The power production of the Lillgrund wind farm is determined numerically using large‐eddy simulations and compared with measurements. In order to simulate realistic atmospheric conditions, pre‐generated turbulence and wind shear are imposed in the computational domain. The atmospheric conditions are determined from data extracted from a met mast, which was erected prior to the establishment of the farm. In order to allocate most of the computational power to the simulations of the wake flow, the turbines are modeled using an actuator disc method where the discs are imposed in the computational domain as body forces which for every time step are calculated from tabulated airfoil data. A study of the influence of imposed upstream ambient turbulence is performed and shows that higher levels of turbulence results in slightly increased total power production and that it is of great importance to include ambient turbulence in the simulations. By introducing ambient atmospheric turbulence, the simulations compare very well with measurements at the studied inflow angles. A final study aiming at increasing the farm production by curtailing the power output of the front row turbines and thus letting more kinetic energy pass downstream is performed. The results, however, show that manipulating only the front row turbines has no positive effect on the farm production, and therefore, more complex curtailment strategies are needed to be tested. Copyright © 2014 John Wiley & Sons, Ltd.
K2S6, a Potassium Polysulfide with Long Sulfur Chain
Authors: Getzschmann Jürgen , Kaskel Stefan
Published: February 2014

K2S6 was prepared in high purity and the crystal structure solved from X‐ray powder data. K2S6 represents the most sulfur rich compound in the K‐S‐phase diagram. The dominating species in the crystal structure are six membered sulfur chains in an all‐trans arrangement.
Species spatial distribution analysis using nearest neighbor methods: aggregation and self‐similarity
Authors: Gao Meng , Wang Xinxiu , Wang De
Published: February 2014

Spatial aggregation and self‐similarity are two important properties in species spatial distribution analysis and modeling. The aggregation parameter k in the negative binomial distribution model and fractal dimension are two widely used measures of spatial aggregation and self‐similarity, respectively. In this paper, we attempt to describe spatial aggregation and self‐similarity using nearest neighbor methods. Specifically, nearest neighbor methods are used to calculate k and box‐counting fractal dimension of species spatial distribution. First, five scaling patterns of k are identified for tree species in a tropical rainforest on Barro Colorado Island (BCI), Panama. Based on the scaling patterns and the means of the nth nearest neighbor distance (NND), the mean NND of higher ranks can be accurately predicted. Second, we describe how to use the theoretical probability distribution model of the nth NND for a homogeneous Poisson process on regular fractals to estimate the fractal dimension. The results indicate that the fractal dimensions estimated using the nearest neighbor method are consistent with those estimated using the scale–area method for 85 tree species on BCI (abundance ≥ 100 individuals and ≤ 5000 individuals). For other tree species, the breakdown of self‐similarity in estimates of fractal dimension causes these two methods to be inconsistent. The applicability of the nearest neighbor method is also discussed.
Differential ability to resist to complement lysis and invade host cells mediated by MBL in R4 and 860 strains of Trypanosoma cruzi
Authors: Evans-Osses Ingrid , Mojoli Andres , Beltrame Marcia Holsbach , da Costa Denise Endo , DaRocha Wanderson Duarte , Velavan Thirumalaisamy P. , de Messias-Reason Iara , Ramirez Marcel Ivan
Published: February 2014

To produce an infection Trypanosoma cruzi must evade lysis by the complement system. During early stages of infection, the lectin pathway plays an important role in host defense and can be activated by binding of mannan‐binding lectin (MBL) to carbohydrates on the surface of pathogens. We hypothesized that MBL has a dual role during parasite‐host cell interaction as lectin complement pathway activator and as binding molecule to invade the host cell. We used two polarized strains of T. cruzi, R4 (susceptible) and 860 (resistant) strains, to investigate the role of MBL in complement‐mediated lysis. Interestingly R4, but not 860 metacyclic strain, markedly increases the invasion of host cells, suggesting that MBL drives the invasion process while the parasite deactivates the Lectin complement pathway.
Autotaxin in the crosshairs: Taking aim at cancer and other inflammatory conditions
Authors: Benesch Matthew G.K. , Ko Yi M. , McMullen Todd P.W. , Brindley David N.
Published: February 2014

Autotaxin is a secreted enzyme that produces most of the extracellular lysophosphatidate from lysophosphatidylcholine, the most abundant phospholipid in blood plasma. Lysophosphatidate mediates many physiological and pathological processes by signaling through at least six G‐protein coupled receptors to promote cell survival, proliferation and migration. The autotaxin/lysophosphatidate signaling axis is involved in wound healing and tissue remodeling, and it drives many chronic inflammatory conditions from fibrosis to colitis, asthma and cancer. In cancer, lysophosphatidate signaling promotes resistance to chemotherapy and radiotherapy, and increases both angiogenesis and metastasis. Research into autotaxin inhibitors is accelerating, both as primary and adjuvant therapy. Historically, autotaxin inhibitors had poor bioavailability profiles and thus had limited efficacy in vivo. This situation is now changing, especially since the recent crystal structure of autotaxin is now enabling rational inhibitor design. In this review, we will summarize current knowledge on autotaxin‐mediated disease processes including cancer, and discuss recent advancements in the development of autotaxin‐targeting strategies. We will also provide new insights into autotaxin as an inflammatory mediator in the tumor microenvironment that promotes cancer progression and therapy resistance.
Incidence of Nonelective Removal of Single-Lumen Silicone and Dual-Lumen Polyurethane Percutaneously Inserted Central Catheters in Neonates
Authors: Costa Priscila , Dorea Eny Paiva , Kimura Amélia Fumiko , Yamamoto Larissa Yumi , Damiani Lucas Petri
Published: February 2014

Objective: To compare the incidence of nonelective removal of single-lumen silicone and dual-lumen polyurethane percutaneously inserted central catheters (PICCs).

Study Design: A prospective cohort study was conducted with neonates in whom 247 PICC lines had been successfully inserted. Patients were assigned to either the single-lumen silicone group or the dual-lumen polyurethane group and nonelective removal incidence was compared using a logistic regression model.

Results: Incidence of nonelective removal in dual-lumen polyurethane PICCs (n =91) was 48.3% versus 34% in single-lumen silicone PICCs (n =156). Thus, dual-lumen polyurethane catheters had a significantly increased chance of nonelective removal compared with single-lumen silicone PICCs (P =.004). The most usual complication in dual-lumen polyurethane PICCs was suspected catheter-related bloodstream infection; in single-lumen silicone PICCs it was external rupture.

Conclusions: Dual-lumen polyurethane PICCs are associated with higher rates of nonelective removal and complications such as suspected catheter-related bloodstream infection. Cautious nursing care is necessary to prevent complications.
Murder! in Thailand's Vernacular Press
Authors: Lim Samson W.
Published: February 2014

A cursory examination of the Thai press reveals two things: A history of censorship, at times violently repressive, and sensational content centered on crime news. Reporters, editors, and publishers have been threatened, intimidated, and murdered in an effort to control the print media while front pages are filled with stories of violent crime and gory photographs. This paper explores both these forms of violence, censorship and crime news, to understand the relationship between the two. It argues that the prevalence of the latter—sensationalism—has resulted in part from the former, a historical process of increasingly murderous repression. So while the form and content of the print media in Thailand, as elsewhere, follow the financial imperatives of the market and reflect trends in current events, they do so within a framework of legal, professional, and informal relationships established over time with seemingly unrelated institutions, including the police.
Epidemiology of vestibular vertigo in a neuro-otology clinic population in Thailand
Authors: Tungvachirakul V , Lisnichuk H , O'Leary S J
Published: February 2014

Objective:

To assess the epidemiology of vestibular vertigo, including the new entity of vestibular migraine, in a neuro-otology clinic population in the biggest public hospital in Thailand.

Study design and setting:

A prospective study involving all patients presenting to the neuro-otology clinic in the Rajavithi Hospital in Bangkok between November 2007 and November 2008.

Subjects and methods:

The population studied consisted of adults referred to the neuro-otology clinic. Accepted international criteria and standardised otological and, when necessary, psychiatric assessment were applied to establish each diagnosis. The association between diagnoses and potential triggers was explored.

Results:

Of the 167 patients assessed, the most prevalent conditions encountered were benign paroxysmal positional vertigo and vestibular migraine. The prevalence of vestibular migraine was 29.3 per cent. No cases of Ménière's disease were encountered. An association was found between vestibular migraine and inadequate sleep, insomnia and changes of head position.

Conclusion:

This study provides current data on the epidemiology of vestibular vertigo in a Thai neuro-otology out-patient population. The results include data on the prevalence of the new diagnostic entity of vestibular migraine, and on its association with potential triggers.
New Left Experiences in Bolivia and Ecuador and the Challenge to Theories of Populism
Authors: COLLINS JENNIFER N.
Published: February 2014

This article explores a paradox at the heart of New Left populism in Bolivia and Ecuador – namely, the election of populist leaders in movement societies. Employing Laclau's theory about the emergence of populism, it demonstrates how social movements, not charismatic leaders, first constructed the popular identities that laid the foundations for these regimes. In re-examining theories of populism in light of these cases, this article suggests that populism's transformative and counter-hegemonic potential needs to be given renewed attention, and that the central role of charismatic leadership should be qualified in terms of the origins of populist identity formation.
A Time of Closure? Participatory Budgeting in Porto Alegre, Brazil, after the Workers' Party Era
Authors: MELGAR TERESA R.
Published: February 2014

Participatory budgeting in Porto Alegre, Brazil, has long been held up as a model of how grassroots social movements, in alliance with a Left party in power, have deepened democracy in a highly clientelistic context. But what happened to this democratic reform when the Partido dos Trabalhadores (Workers' Party, PT), which supported this initiative while it held the mayorship of Porto Alegre for 16 years, lost political power? This article examines the shifting fortunes of the participatory budgeting process following the defeat of the Workers' Party in the 2004 local elections. It explores how and why succeeding local administrations weakened participatory budgeting amid the changing political configuration of Porto Alegre, underscoring the critical role played by considerable executive branch powers in the process. The article concludes by examining what questions this raises for the sustainability of local democratic reforms.
Non-Markovian dynamics of dust charge fluctuations in dusty plasmas
Authors: Asgari H. , Muniandy S. V. , Ghalee Amir
Published: February 2014

Dust charge fluctuates even in steady-state uniform plasma due to the discrete nature of the charge carriers and can be described using standard Langevin equation. In this work, two possible approaches in order to introduce the memory effect in dust charging dynamics are proposed. The first part of the paper provides the generalization form of the fluctuation-dissipation relation for non-Markovian systems based on generalized Langevin equations to determine the amplitudes of the dust charge fluctuations for two different kinds of colored noises under the assumption that the fluctuation-dissipation relation is valid. In the second part of the paper, aiming for dusty plasma system out of equilibrium, the fractionalized Langevin equation is used to derive the temporal two-point correlation function of grain charge fluctuations which is shown to be non-stationary due to the dependence on both times and not the time difference. The correlation function is used to derive the amplitude of fluctuations for early transient time.
Solution of Grad–Shafranov equation by the method of fundamental solutions
Authors: Nath D. , Kalra M. S.
Published: February 2014

In this paper we have used the Method of Fundamental Solutions (MFS) to solve the Grad–Shafranov (GS) equation for the axisymmetric equilibria of tokamak plasmas with monomial sources. These monomials are the individual terms appearing on the right-hand side of the GS equation if one expands the nonlinear terms into polynomials. Unlike the Boundary Element Method (BEM), the MFS does not involve any singular integrals and is a meshless boundary-alone method. Its basic idea is to create a fictitious boundary around the actual physical boundary of the computational domain. This automatically removes the involvement of singular integrals. The results obtained by the MFS match well with the earlier results obtained using the BEM. The method is also applied to Solov'ev profiles and it is found that the results are in good agreement with analytical results.
Revision of genusCrassostrea(Bivalvia: Ostreidae) of Brazil
Authors: Amaral Vanessa Simão Do , Simone Luiz Ricardo L.
Published: February 2014

The Ostreidae are well known for their high intra-specific variation, which makes identification problematic. The present paper aims to provide a morpho-anatomical and taxonomic review of the Brazilian species ofCrassostrea, as well as some congeneric species from other relevant areas. The Brazilian species areCrassostrea manglesp.nov. andCrassostrea brasiliana. The exotic speciesCrassostrea gigas, cultivated in the southern region of the country, is also included in this study. Additional species are:Crassostrea virginica, from the Atlantic coast of the USA, the type species, andCrassostrea rhizophorae, a south-eastern Caribbean species that is supposed to occur in Brazil, but is here understood as a different entity endemic to that region. Taking into account their economic importance, the differentiation between these species is critical, and is essential for a better planning of production and preservation strategies. We point out the differences in almost all structures amongst these species, which are formally redescribed herein. The occurrence of the African speciesCrassostrea gasarin Brazil is established as false. The voucher specimens of previous studies responsible for this assumption were examined, evidencing a misidentification forCrassostrea brasilianafrom an estuarine environment. The geographical distribution of the studied species is recognized as follows:Crassostrea rhizophoraein the south-east Caribbean Sea;Crassostrea manglesp. nov. from Pará to the Santa Catarina, only in mangroves;Crassostrea brasilianafrom Paraíba to Santa Catarina, both in rocky shores and mangroves;Crassostrea virginicaranges from the Atlantic coast of Canada to the Caribbean; andCrassostrea gigasoriginates from the Indo-Pacific, but has been introduced in southern Brazil. This paper also deals with conchological aspects of the endemic speciesCrassostrea praia, from south Lagoa dos Patos, Rio Grande do Sul; after a more detailed definition, and considering the deleterious effects of the nearby port and construction sites, it can be classified as an endangered species.
Prognosis of schizophrenia in persons with and without a history of cannabis use
Authors: Manrique-Garcia E. , Zammit S. , Dalman C. , Hemmingsson T. , Andreasson S. , Allebeck P.
Published: February 2014

Background

The aim of the study was to determinate whether schizophrenia patients with a history of cannabis use have a different prognosis, with regards to readmission and hospital duration, compared with those without a history of cannabis use.

Method

The present investigation was a cohort study of 50 087 Swedish men with data on cannabis use at the ages of 18–20 years. A total of 357 cases of schizophrenia were identified from in-patient care and followed up from 1973 to 2007.

Results

Schizophrenia patients with a history of cannabis use had a higher median duration of first hospital episode (59 days v. 30 days). Patients with a history of cannabis use had a higher median rate of readmission (10 times v. four times). Also, total number of hospital days was higher in patients with a history of cannabis use compared with those without (547 days v. 184 days). Patients with a history of cannabis use had an increased odds of having more than 20 hospital readmissions compared with non-users [3.1, 95% confidence interval (CI) 1.3–7.3] as well as an increased odds of hospital admission lasting more than 2 years (2.4, 95% CI 1.1–7.4) after controlling for diagnosis of personality disorders, family socio-economic position, IQ score, civil status, place of residence, risky use of alcohol and use of other drugs. Patients with a history of cannabis use were less likely to have paranoid schizophrenia compared with never users (8% v. 17%) in the first admission.

Conclusions

Schizophrenia patients with a history of cannabis use had a significantly higher burden of lifetime in-patient care than non-cannabis users. Not only does cannabis increase the risk of schizophrenia, but also our findings indicate that the course and prognosis of schizophrenia may be more severe than schizophrenia cases in general.
Collateral outcomes in e-mental health: a systematic review of the evidence for added benefits of computerized cognitive behavior therapy interventions for mental health
Authors: Musiat P. , Tarrier N.
Published: February 2014

Background.

E-mental health is a growing research field and an increasing number of computerized cognitive behavior therapy (cCBT) interventions are available for numerous mental health issues. Such interventions are often claimed to have added benefits, or collateral outcomes, when compared with traditional delivery platforms. Our aim was to systematically review the evidence of the cost-effectiveness, geographic flexibility, time flexibility, waiting time for treatment, stigma, therapist time, effects on help-seeking and treatment satisfaction of cCBT interventions for mental health.

Method.

The electronic databases Medline and Web of Science were searched for peer-reviewed controlled trials investigating collateral outcomes in computerized and internet-based CBT.

Results.

The literature search identified 101 published papers (95 studies), which were included in this review. The results suggest that cCBT interventions are cost-effective and often cheaper than usual care. Limited evidence was found with regard to geographic flexibility, time flexibility, waiting time for treatment, stigma and the effects on help-seeking. Personal support in cCBT was found to take many forms, was not limited only to therapists, and seemed to increase treatment adherence and reduce attrition. Treatment satisfaction with cCBT was found to be high, but more research on attrition due to dissatisfaction is required.

Conclusions.

Although the results of this systematic review on the collateral outcomes provide support for the potential of cCBT, these outcomes need to be better assessed within individual e-mental health studies.
Recusatioas Political Theatre: Horace's Letter to Augustus
Authors: Freudenburg Kirk
Published: February 2014

Among the most potent devices that Roman emperors had at their disposal to disavow autocratic aims and to put on display the consensus of ruler and ruled was the artful refusal of exceptional powers, orrecusatio imperii. The practice had a long history in Rome prior to the reign of Augustus, but it was Augustus especially who, over the course of several decades, perfected therecusatioas a means of performing his hesitancy towards power. The poets of the Augustan period were similarly well practised in the art of refusal, writing dozens of poeticrecusationesthat purported to refuse offers urged upon them by their patrons, or by the greater expectations of the Augustan age, to take on projects. It is the purpose of this paper to put the one type of refusal alongside the other, in order to show to what extent the refusals of the Augustan poets are informed not just by aesthetic principles that derive, most obviously, from Callimachus, but by the many, high-profile acts of denial that were performed as political art by the emperor himself.
Basic Old-Age Pension and financial wellbeing of older adults in South Korea
Authors: SHIN EUNHAE , DO YOUNG KYUNG
Published: February 2014

South Korea's old-age poverty rate is among the highest in the developed world. Confronted with the increasing demand for a social safety net for older people, the South Korean government introduced the Basic Old-Age Pension (BOAP) in 2008. The BOAP is a non-contributory, means-tested pension covering 70 per cent of the elderly population, with monthly benefits amounting to 84 kW (thousand Korean won, approximately equivalent to US $1) for singles and 139 kW for couples. Little empirical research has been conducted, however, to evaluate the effectiveness of the new pension programme in supporting the financial wellbeing of older people. Using data from the 2008–2010 Korea Welfare Panel Study, a panel data analysis is conducted to estimate the effects of the BOAP on three sets of financial wellbeing measures: financial difficulty, monthly consumption and overall financial satisfaction. The results suggest that the BOAP has beneficial effects on the financial wellbeing of older people by improving affordability of basic subsistence items such as heating and nutritious meals, particularly among the older-old group. However, the effects are limited to these few outcomes only; overall financial wellbeing and other important indicators remain unchanged.
Characterization of laser-driven electron and photon beams using the Monte Carlo code FLUKA
Authors: Fiorini F. , Neely D. , Clarke R.J. , Green S.
Published: February 2014

We present a new simulation method to predict the maximum possible yield of X-rays produced by electron beams accelerated by petawatt lasers irradiating thick solid targets. The novelty of the method lies in the simulation of the electron refiluxing inside the target implemented with the Monte Carlo code Fluka. The mechanism uses initial theoretical electron spectra, cold targets and refiluxing electrons forced to re-enter the target iteratively. Collective beam plasma effects are not implemented in the simulation. Considering the maximum X-ray yield obtained for a given target thickness and material, the relationship between the irradiated target mass thickness and the initial electron temperature is determined, as well as the effect of the refiluxing on X-ray yield. The presented study helps to understand which electron temperature should be produced in order to generate a particular X-ray beam. Several applications, including medical and security imaging, could benefit from laser generated X-ray beams, so an understanding of the material and the thickness maximizing the yields or producing particular spectral characteristics is necessary. On the other more immediate hand, if this study is experimentally reproduced at the beginning of an experiment in which there is an interest in laser-driven electron and/or photon beams, it can be used to check that the electron temperature is as expected according to the laser parameters.
Secular trends in invasive meningococcal disease, Massachusetts, 1988–2011: what happened to invasive disease?
Authors: PERUSKI A. H. , KLUDT P. , PATEL R. S. , DeMARIA A.
Published: February 2014

Invasive meningococcal disease (IMD) reported to the Massachusetts Department of Public Health from 1988 to 2011 was reviewed. The average annual incidence of IMD/100 000 decreased from 1·57 [95% confidence interval (CI) 1·42–1·73] for 1988–1991 to 0·22 (95% CI 0·17–0·29) for 2008–2011. The pattern of decreasing incidence over time differed by age group. There was a decrease in IMD/100 000 in the 0–4 years age group after 1991 from 10·92 (95% CI 8·08–14·70) in 1991 to 5·76 (95% CI 3·78–8·72) in 1992. Incidence in the 0–4 years age group remained below 5/100 000 per year on average thereafter. A substantial reduction in incidence in all age groups was observed between 2000 and 2009, which began before the introduction of conjugate meningococcal vaccine in 2005. Marked reductions in incidence of IMD in Massachusetts, and elsewhere, deserve further investigation with respect to potential factors that go beyond the introduction and deployment of improved meningococcal vaccines.
EXOTICISM IN GERTRUDE BELL'SPERSIAN PICTURES
Authors: Ghaderi Farah , Wan Yahya Wan Roselezam
Published: February 2014

Victorian travelers in colonial contextsencountered differences in landscape, mores and manners, society, politics and culture, among other things, and registered their responses to the places visited in their published travel books for the home audience. Postcolonial critics contend that exoticism, i.e., a Western traveler's response to and description of the differences encountered in the context of travel, was deeply informed by the asymmetrical power relation between the representer/colonizer and the represented/colonized. As a result, these critics argue, exoticism in colonial travel writing was appropriative since it tended to construct the dichotomy of self/other in such a way as to justify imperial interventions in other countries (Forsdick, “Sa(L)Vaging Exoticism” 30–34; Said 1–28). As Graham Huggan rightly argues, difference of the colonial other in its various aspects was denigrated and dismissed as exotic when “translated into the master code of empire,” since it superimposed “a dominant way of seeing, speaking and thinking onto marginalised peoples” (24).
Simultaneous Hydrogen and Heavier Element Isotopic Ratio Images with a Scanning Submicron Ion Probe and Mass Resolved Polyatomic Ions
Authors: Slodzian Georges , Wu Ting-Di , Bardin Noémie , Duprat Jean , Engrand Cécile , Guerquin-Kern Jean-Luc
Published: February 2014

In situ microanalysis of solid samples is often performed using secondary ion mass spectrometry (SIMS) with a submicron ion probe. The destructive nature of the method makes it mandatory to prevent information loss by using instruments combining efficient collection of secondary ions and a mass spectrometer with parallel detection capabilities. The NanoSIMS meets those requirements with a magnetic spectrometer but its mass selectivity has to be improved for accessing opportunities expected from polyatomic secondary ions. We show here that it is possible to perform D/H ratio measurement images using 12CD−/12CH−, 16OD−/16OH−, or 12C2D−/12C2H− ratios. These polyatomic species allow simultaneous recording of D/H ratios and isotopic compositions of heavier elements like 15N/14N (via 12C15N−/12C14N−) and they provide a powerful tool to select the phase of interest (e.g., mineral versus organics). We present high mass resolution spectra and an example of isotopic imaging where D/H ratios were obtained via the 12C2D−/12C2H− ratio with 12C2D− free from neighboring mass interferences. Using an advanced mass resolution protocol, a “conventional” mass resolving power of 25,000 can be achieved. Those results open many perspectives for isotopic imaging at a fine scale in biology, material science, geochemistry, and cosmochemistry.