bluuebunny/crossref_metadata_2025 huggingface dataset:
Physical Properties of Yarn from Paper Mulberry
Authors: Chonsakorn Sakorn , Piromthamsiri Kajijarus , Sirikasemlert Chanchai
Published: November 2013

This research were examined the spinning processes of paper mulberry yarn and also investigated the physical properties of paper mulberry yarn. The results show that a possibilities of spinning of paper mulberry fiber into yarn which is a longitudinal view similar to that of cotton. An average yarn count, tenacity and elongation are 1,022 tex, 66.39 cN/tex, and 17.80%, respectively. These results represent the beginning of the research to rescue traditional knowledge, combined with the possibility of the introduction of a new textile fiber on the market.
Numerical Investigation of Natural Convection of Nanofluids in L-Shaped Enclosures
Authors: Che Sidik Nor Azwadi , Safdari Arman
Published: November 2013

This paper presents numerical investigations of the thermal and fluid flow behavior in an L-shaped of cavity filled with nanofluid. For this purpose, five different water based Cu nanoparticles were selected with concentration of 1%, 3% and 5% were used. Effects of the presence of nanoparticles on the thermal and fluid flow in the enclosure were investigated in different Rayleigh number (Ra = 103, 104 and 105). Results show that the characteristic of flow and heat transfer are mainly dependent on the dimensionless Rayleigh number. We also found that the presence of nanoparticle enhances the heat transfer rate in the enclosure.
Utilization of Tannery Wastewaters Sludge Ash in Waterproofing Membrane: A Technical and Environmental Feasibility Study
Authors: Puccini Monica , Seggiani Maurizia , Castiello Domenico , Vitolo Sandra
Published: November 2013

Sludge from tannery effluent treatment processes is a by-product of leather-making industry, in which chrome compounds are the most common used materials. The objective of this work was to investigate the effects and feasibility in the use of tannery sludge ash as a partial or total replacement of usual mineral filler such as in manufacture of waterproofing membranes. The effects of sludge ash on the morphology and mechanical properties of membranes were investigated. Leaching tests were carried out in order to guarantee that the fulfilment of filler function was done in respect with environmental criteria. Besides, a Life Cycle Assessment (LCA) analysis was performed in order to assess the environmental performance of the waterproofing membrane filled by tannery sludge ash in comparison with the conventionally filled membrane. The performances of the membranes and the results of environmental assessment indicate that tannery sludge ash may be used as total replacement of CaCO3 for waterproofing membranes.
Analysis of Mechanical Behaviour of the Concreat Filled Double Skin Steel TubesK-Joint
Authors: Jia Yu Zhuo , Zhou Chen Feng , Li Cheng Cheng , Zhang Liang
Published: November 2013

In recent years, a new kind struct of concreat-filled skin steel tubesConcrete-Filled Double Skin Steel Tubes (CFDST),are more used in transmission line constructions. It is a kind of hollow structs, which concentric placed the double skin steel tubes, and filling with concrete between the two steel tubes[.CFDST K-joints on power transmission tower must be finite element simulated to research the capacity of bond-slip between the steel and concrete by the finite element analysis software-ANSYS 10.0 in this paper, and finally gets the ultimate bearing capacity and failure modes of K-joints.
Preparation of Silk Fibroin/Gelatine Blend Nanofibresby Roller Electrospinning Method
Authors: Sasithorn Nongnut , Martinová Lenka
Published: November 2013

This study was focused on the preparation of electrospunnanofibres from silk fibroin (SF)/gelatin (GP) blends solution using a roller electro spinning method. The effects of mixing ratio in SF/GP blend solution on properties of spinning solution (e.g., viscosity, conductivity and surface tension) and morphology of electrospunfibres were studied. The SF/GP blends solution containing up to the gelatin content of 30% could be electro spun into the continuous fibrous structure. Average diameter of SF/GP electrospunfibres were increased by increasing the amount of gelatin in spinning solution. The SF/GP electrospunfibres showed bigger diameter and broader diameter distribution than pure silk fibroin electrospunfibres. The SF/GP nanofibres had diameters ranging from 400 to 1300 nm.
Study of Microstructure and Mechanical Properties of Sintered Aluminum Alloy Composite Reinforced with Al2O3 Nanoparticles
Authors: Senthilkumar R. , Arunkumar N. , Manzoor Hussain Mohammed , Vijayaraj R.
Published: November 2013

In this research, aluminum alloy AA2014 matrix composites reinforced with micron (10% wt 5% wt) and nanoparticles (1% wt 5% wt) of Al2O3 were fabricated through powder metallurgy method. Optimum amount of reinforcement were determined by evaluating mechanical properties like micro-hardness and compressive strength of composites. The composite samples were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results reveal that the composites containing 2% wt of nanoAl2O3 and 8 % micro Al2O3 reinforcement has homogenous microstructure as well as superior mechanical properties.
AISI H13 Hot-Work Steel with Hard Chromium Plating Thermal Fatigue Behavior Evaluation
Authors: Yeh Shu Hung , Chiu Liu Ho , Lin Shou Chi , Pan Yeong Tsuen
Published: November 2013

A hard-coating on hot work tool steel can be used to obtain higher corrosion resistance, as well as better wear resistance. This study investigates the thermal fatigue performance of AISI H13 hot work tool steel with and without hard chromium plating. Treated specimens were characterized using microstructural analysis, X-ray diffraction analysis and microhardness measurement. The thermal fatigue test is based on cyclic induction heating and water cooling. The specimen was heated to the maximum surface temperature of 670°C followed with water injection to bring the specimen down to a minimum temperature of 25°C. The thermal fatigue testing in this study was conducted using 500 cycles. A vacuum heat treated specimen with a hardness of 47 HRC was used as the reference material. The hard chromium plated layer with a thickness 35 μm had a hardness of 930 HV0.1. The damage factor, defined as crack depth × crack width, of quenched and tempered H13 specimens and hard chromium plated specimens were 800 and 1760, respectively. The damage factor evaluation verified the vacuum heat treated specimen thermal fatigue resistance is superior to that of the hard chromium plated specimen.
Positron Annihilation Lifetime Spectroscopy Measurement of Ge5As37S58 Glass
Authors: Stronski Alexander
Published: November 2013

Defect configuration of Ge5As37S58chalcogenide glasses was studied by positron annihilation lifetime spectra (PALS). Size of nanovoids was determined using Liaos formula for radius of nanovoids in spherical approximation. Peculiarities of structural features were obtained from Raman spectra.
Peculiarities of the Impurity Redistribution under Ultra-Shallow Junction Formation in Silicon
Authors: Litovchenko V.G. , Romanyuk B. , Oberemok O. , Popov V. , Melnik V. , Rudenko K. , Vyurkov V.
Published: November 2013

Ultra-shallow junctions (USJs) were formed by low-energy As ion implantation with the subsequent furnace annealing. It was found that the significant amount of oxygen is redistributed from the silicon bulk to the arsenic-implanted region. We present the effect of oxygen gettering at the creation of arsenic-doped USJs using the marker layer created by ion implantation of 18O isotope.
Acoustic Phonon and Surface Roughness Spin Relaxation Mechanisms in Strained Ultra-Scaled Silicon Films
Authors: Osintsev Dmitry , Sverdlov V. , Selberherr Siegfried
Published: November 2013

We consider the impact of the surface roughness and phonon induced relaxation on transport and spin characteristics in ultra-thin SOI MOSFET devices. We show that the regions in the momentum space, which are responsible for strong spin relaxation, can be efficiently removed by applying uniaxial strain. The spin lifetime in strained films can be improved by orders of magnitude, while the momentum relaxation time determining the electron mobility can only be increased by a factor of two.
On the Mobility Behavior in Highly Doped Junctionless Nanowire SOI MOSFETs
Authors: Rudenko Tamara , Yu R. , Barraud S. , Cherkaoui K. , Razavi P. , Fagas G. , Nazarov A.N.
Published: November 2013

The electron mobility in highly-doped junctionless (JL) nanowire (NW) silicon-on-isulator (SOI) MOSFETs with various nanowire widths is experimentally studied and analyzed. The evidence for the considerable enhancement of the effective electron mobility in narrow NW devices as compared to counterpart planar (wide) devices, having the same film thickness and doping, and as compared to the bulk silicon mobility with the same doping is presented. This mobility enhancement increases with decreasing the NW width. The reason for this effect is considered to be reduction of the impurity Coulomb scattering in narrow NW MOSFETs due to: (i) the reduced depletion-layer width; (ii) stronger screening of ionized impurities; (iii) the reduced number of neighbor ionized doping atoms per each free carrier in very narrow NWs. These results are of great importance since mobility degradation due to high doping was considered to be one of the most important limitations of the JL NW MOSFETs.
Carbon-Rich Nanostructurated a-SiC on Si Heterostructures for Field-Effect Electron Emission
Authors: Nazarov A.N. , Gordienko S.O. , Lytvyn P.M. , Stadnik A.A. , Gomeniuk Y.Y. , Vasin A.V. , Rusavsky A.V. , Nazarova T.M. , Lysenko V.S.
Published: November 2013

The paper describes emission properties of a new nanostructured material carbon-rich amorphous silicon carbide (a-SiC) deposited on silicon wafer. Proposed material technology demonstrates that the field enhancement factor of the electron emission of this material can reach 1000 with the current density of about 1x10-3A/cm2 and efficiency of electron emission ~10%. A good correlation between the charge transfer through the a-SiC layer and electron emission from the material in high vacuum is observed.
Characterisation of Residual Stress State and Distortion in Welded Plates Stress Engineered by Local Mechanical Tensioning
Authors: Ganguly Supriyo , Wescott Andrew , Nagy T. , Colegrove P. , Williams Stewart W.
Published: November 2013

Local mechanical tensioning is one of the most efficient and industrially relevant stress engineering techniques to modify weld residual stress field and subsequently reduce buckling distortion. However, application of rolling load and its magnitude need to be optimised for an energy efficient rolling process. In the present study gas metal arc butt welded plates of low carbon mild steel were rolled by a dual roller in different rolling configuration (top and reverse side rolling) and with different magnitude of rolling load. All the plates were rolled post welding. Residual strain profiles of the post weld rolled plates were measured, using the SALSA strain scanner, and the in-plane stress were characterized. Average distortion of the rolled plates was correlated with the residual stress. Reverse rolling was found to be more effective in removing distortion while the stress profiles did not show any significant reduction of the peak stress.
In Situ Neutron Diffraction Measurements of the Deformation Behavior in High Manganese Steels
Authors: Kang Mihyun , Woo Wan Chuck , Em Vyacheslav , Lee Young Kook , Seong Baek Seok
Published: November 2013

Deformation behavior of high Mn TWIP (twinning induced plasticity) steels was observed using neutron diffraction. Two kinds of specimens were prepared; 0 and 2 wt% of Al TWIP steels. The lattice strains and peak widths of hkl grains were measured under tensile loading. The results provide an insight into the influence of the Al contents on the deformation behavior associated with the microstructure changes in TWIP steels.
Osteomas of the craniofacial region: A case series and review of literature
Authors: Gundewar Sagar , Kothari Deepak S. , Mokal Nitin J. , Ghalme Amol
Published: November 2013

Objective: 0 To discuss the clinical presentation, diagnosis and management of osteomas involving the craniomaxillofacial region. Materials and Methods: This study was conducted from June 2004 to March 2012 at our institute. A total of 12 cases between the ages of 10 and 50 years were managed with surgical excision and reconstruction. The criteria used to diagnose osteoma included radiographic and clinical features and histological confirmation of the specimen. The total follow-up period ranged from 6 to 24 months. Results: Out of 12 osteomas, 10 were peripheral and 2 were centrally located. Mandible involvement was seen in six patients, four involved the orbit, one the frontal bone and one the frontal bone with the skull base. All patients undergoing excision and reconstruction had a favourable aesthetic and functional outcome. There were no recurrences and no post-operative complications. Conclusion: Osteomas affect all age groups with no sex predilection and are usually clinically asymptomatic till they become large in size. Surgical excision and appropriate reconstruction is the mainstay of management. Surgery is indicated when lesion is symptomatic or actively growing and the surgical approach for exposure of the lesion should be case specific.
The effect of different positions on lower limbs skin perfusion pressure
Authors: Kawasaki Tota , Uemura Tetsuji , Matsuo Kiyomi , Masumoto Kazuyuki , Harada Yoshimi , Chuman Takahiro , Murata Tomoyuki
Published: November 2013

We have encountered situations of patients with critical limb ischemia accompanied by pain at rest and necrosis, who hang their legs down from the bed during sleep. This lower limb position is known to be a natural position, which reduces pain in the lower extremity induced by ischemia. However, the effect of this position on blood flow of the lower extremity is poorly understood. We studied whether measurements of skin perfusion pressure (SPP) changes by leg position and the difference between healthy adults and patients with critical limb ischemia. The subjects of this study were 10 healthy adults and 11 patients with critical limb ischemia. Patients with critical limb ischemia, including both dorsum of foot and plantar of foot, having SPP of lower limbs of less than 40 mmHg (supine position) were the object of this study. SPP was measured on four positions (supine position, lower limbs elevation position, sitting position, and reclining bed elevation of 20° position). In sitting position, both the number of healthy adults and critical patients show significant increases in SPP compared with the other three positions. These results suggest that sitting position is effective to keep good blood stream of lower limbs not only in healthy adults but also in patients with critical limb ischemia. However, an appropriate leg position should not have lower limbs hang downwards for long periods time because edema is caused by the fall in venous return in lower limbs, and the wound healing is prolonged.

Our clinical research could be more useful in the future, particularly in developing countries, for surgeons managing wounds in leg and foot and preserving ischemic limbs.
Aesthetical outcome after breast reconstruction using deep inferior epigastric perforator flap: Personal techniques
Authors: Gelati Chiara , Negosanti Luca , Fabbri Erich , Cipriani Riccardo
Published: November 2013

Background: Now-a-days, deep inferior epigastric perforator (DIEP) flap breast reconstruction is widespread throughout the world. The aesthetical result is very important in breast reconstruction and its improvement is mandatory for plastic surgeons. Materials and Methods: The most frequent problems, we have observed in breast reconstruction with DIEP flap are breast asymmetry in terms of volume and shape, the bulkiness of the inferior lateral quadrant of the new breast, the loss of volume of the upper pole and the lack of projection of the inferior pole. We proposed our personal techniques to improve the aesthetical result in DIEP flap breast reconstruction. Our experience consists of more than 220 DIEP flap breast reconstructions. Results: The methods mentioned for improving the aesthetics of the reconstructed breast reported good results in all cases. Conclusion: The aim of our work is to describe our personal techniques in order to correct the mentioned problems and improve the final aesthetical outcome in DIEP flap breast reconstruction.
Proceedings of the 2013 Meeting of the Animal Science Modelling Group
Authors: France J. , Kebreab E. , Metcalf J. A. , Hanigan M. D.
Published: November 2013

This group meets yearly for one-day meetings. The 2013 meeting was sponsored by Nutreco Canada, Inc., Guelph, ON, Canada; ADM, Decatur, IL, USA; Cargill Animal Nutrition, Elk River, MN, USA; Ajinomoto Heartland, Inc., Chicago, IL, USA; Adisseo, Alpharetta, GA, USA; Lallemand Specialties, Inc., Milwaukee, WI, USA and Evonik Industries AG, Hanau, Germany. It was held on July 7 at the Hyatt Regency Indianapolis, One South Capital Avenue, Indianapolis, Indiana, USA, prior to the ADSA/ASAS Joint Annual Meeting. Summaries of the papers presented follow. Each summary has been peer reviewed and edited for clarity. The person who presented the paper is identified with an e-mail address.
Effect of maturity on physicochemical and cooking characteristics in yellow peas (Pisum sativum)
Authors: Wang N. , Castonguay G.
Published: November 2013

Wang, N. and Castonguay, G. 2014. Effect of maturity on physicochemical and cooking characteristics in yellow peas (Pisum sativum). Can. J. Plant Sci. 94: 565–571. The effect of maturity on physicochemical and cooking properties of yellow peas was investigated. Results indicated that when compared with mature yellow peas, immature yellow peas exhibited significantly lower seed weight (16.4–18.1% less) and smaller seed size (5.9–6.9% less), but higher water hydration capacity (3.7–11.5% more). Significant shorter cooking time but higher firmness value of cooked seeds was observed for immature yellow peas than for mature yellow peas. Immature yellow peas contained significantly higher mean protein content (254.2 vs. 234.6 g kg−1 DM), higher mean crude fiber (67.8 vs. 63.0 g kg−1 DM), and higher mean ash content (31.5 vs. 29.4 g kg−1 DM), but significantly lower mean starch content (432.5 vs. 451.3 g kg−1 DM) as compared with mature yellow peas. Sucrose content was significantly higher in immature yellow peas than that in mature yellow peas, whereas stachyose and verbascose contents were significantly higher in mature yellow peas than in immature yellow peas. Phytic acid content in immature yellow peas was significantly higher than that in mature yellow peas, while trypsin inhibitor activity was not significant. This information will be useful in setting the grading standards for yellow peas in Canada.
Comparación de la anticoagulación medida con el dispositivo Inratio®, en muestras obtenidasde la fístula arteriovenosa frente a muestras capilares
Authors: Sáenz Santolaya José Alfredo , Herrera Martín Elena , Díaz de Argote-Cervera Pilar , Cerrajero Calero Raquel , López Puerta Cristina , Arribas-Cobo Patricia
Published: November 2013

Los controles a pacientes tratados con Sintrom® han evolucionado hacia métodos de determinación en sangre capilar por ser más fácil de extraer, menos cruento, más barato y tener resultados inmediatos.En cada sesión de hemodiálisis extraemos sangre de una fístula arteriovenosa lo que facilita una muestra para el control del tratamiento con Sintrom® disminuyendo el número de punciones venosas sin aumentar la carga de trabajo de enfermería.
Objetivo: Comparar los resultados de INR determinados con el método INRatio® en muestras sanguíneas capilares y arteriovenosa.Material y métodosSe estudiaron 7 pacientes anticoagulados con Sin-trom®, portadores de fístula arteriovenosa. Se compararon 3 muestras, una periférica, analizada en el laboratorio y otras 2 utilizando el método INRATIO® para análisis de INR en sangre capilar. Una de las muestras fue extraída según recomen-daciones del fabricante, y otra extraída del acceso vascular según protocolo de la unidad. Resultados: El INR medio determinado en la muestra capilar fue 2.5 ±1; Fístula arteriovenosa 2.1 ±0.4 y labo-ratorio 2.1 ±0.4. No existieron diferencias ni estadísticas ni clínicas signifi cativas. Conclusión: La utilización del método INRatio® de determinación de INR capilar con muestras del acceso vascular sería adecuado en hemodiálisis al ser igual de fiable que los métodos tradicionales. El uso del medidor INRATIO con muestra extraída de la fístula arteriovenosa presenta unos benefi cios de facilidad de acceso a la muestra, sencillez en la determinación, inmediatez en los resultados, comodidad y un ahorro económico para el sistema sanitario.
Estudio comparativo en pacientes en Hemodiafiltración en línea postdilucional de alta eficacia con diferentes flujos de líquido dializante, tiempo programado y tiempo real
Authors: Aznar Barbero Sonia , Bel Cegarra Ramón , Badallo Mira Mª Magdalena , Pagán Escribano David , García Nicolás Asensio Bartolomé
Published: November 2013

La dosis de diálisis es un elemento fundamental en la diálisis adecuada y en la supervivencia del paciente. Entre los elementos que infl uyen en la misma destacan: tiempo, flujo sanguíneo (Qb), coeficiente de transferencia de masa de urea (KoA) y fl ujo del baño (Qd). El objetivo es evaluar si con Qd 800 ml/min y tiempo programado 240 minutos conseguimos mayor eficacia que con Qd 500 ml/min y tiempo programado 240 minutos y con Qd 500 l/min y tiempo efectivo 240 minutos.
Pacientes y métodos
Estudio prospectivo sobre población prevalente en hemodiálisis, con criterio de inclusión pacientes mayores de edad en hemodiafi ltración on-line postdilucional con flujo sanguíneo adecuado.
En cada paciente se realizan 18 sesiones consecutivas variando Qd y tiempo con siguiente esquema:
Fase 1: 6 sesiones con Qd 800 ml/min y tiempo programado
240 minutos.
Fase 2: 6 sesiones con Qd 500 ml/min y tiempo programado
240 minutos,
Fase 3: 6 sesiones con Qd 500 ml/min y tiempo
efectivo 240 minutos.
El análisis estadístico se realiza mediante SPSS 13.0 para Windows.
Las variables cuantitativas se expresan como media, desviación estándar y rango. Las variables cualitativas, como frecuencia y porcentaje.
Resultados
Analizamos 432 sesiones obteniendo Kt y Volumen total de reinfusión (VTR) mayores en la fase 3 del estudio con respecto a las otras dos, no existiendo diferencias signifi cativas entre la fase 1 y 2.
Discusión y conclusiones
No existen diferencias en la efi cacia dialítica entre Qd 500 ml/min y Qd 800 ml/min, mientras que con el aumento de 10 minutos de media en cada sesión, se incrementa la dosis de diálisis en 2,77 litros y el VTR en un 9%, reduciendo a la mitad el número de pacientes que no logran los 20 litros de volumen de reinfusión. Y esto, con un menor coste adicional especialmente por las diferencias de envasado del bicarbonato.
Catéter transhepático: última opción de acceso vascular en mujer de 26 años
Authors: Aznar Barbero Sonia , Bel Cegarra Ramón , Badallo Mira Mª Magdalena , Pagán Escribano David , Chica Arellano Josefina , García Nicolás Asensio Bartolomé
Published: November 2013

El acceso vascular (AV) es la base fundamental de todo tratamiento extracorpóreo de diálisis, su funcionamiento adecuado infl uye directamente en la calidad de vida del paciente y en su morbi-mortalidad. El AV vascular ideal debe permitir el abordaje seguro y continuado del sistema vascular, proporcionar fl ujos sufi cientes para alcanzar una dosis de diálisis adecuada y carecer de complicaciones. Según las guías SEN la primera opción de AV es la fístula arteriovenosa (FAV): nativa preferentemente, protésica, etc. Sin embargo, cuando estas posibilidades se agotan, se recurre a catéteres permanentes tunelizados.
Meteor smoke influences on the D-region charge balance – review of recent in situ measurements and one-dimensional model results
Authors: Baumann C. , Rapp M. , Kero A. , Enell C.-F.
Published: November 2013

Abstract. This work investigates the influence of meteoric smoke particles (MSP) on the charge balance in the D-region ionosphere. Both experimental in situ measurements and a one-dimensional ionospheric model reveal a clear impact of MSP on the ionospheric composition of the D-region. The study reviews rocket-borne in situ measurements of electron and positive ion density, which show a distinct deficit of electrons in comparison to positive ions between 80 and 95 km. This deficit can be explained by the ambient negatively charged MSP measured simultaneously with a Faraday cup. The influence of MSP on the D-region charge balance is addressed with a simplified ionospheric model with only six components, i.e. electrons, positive and negative ions and neutral and charged MSP (both signs). The scheme includes reactions of plasma captured by MSP and MSP photo reactions as well as the standard ionospheric processes, e.g. ion-ion recombination. The model shows that the capture of plasma constituents by MSP is an important process leading to scavenging of electrons. Since Faraday cup measurements are biased towards heavy MSP because of aerodynamical filtering, we have applied an estimate of this filter on the modelled MSP densities. By doing that, we find good qualitative agreement between the experimental data and our model results. In addition, the model study reveals an increase of positive ions in the presence of MSP. That is primarily caused by the reduced dissociative recombination with electrons which have been removed from the gas phase by the MSP.
Distribution of phytoplankton functional types in high-nitrate, low-chlorophyll waters in a new diagnostic ecological indicator model
Authors: Palacz A. P. , John M. A. St. , Brewin R. J. W. , Hirata T. , Gregg W. W.
Published: November 2013

Abstract. Modeling and monitoring plankton functional types (PFTs) is challenged by the insufficient amount of field measurements of ground truths in both plankton models and bio-optical algorithms. In this study, we combine remote sensing data and a dynamic plankton model to simulate an ecologically sound spatial and temporal distribution of phyto-PFTs. We apply an innovative ecological indicator approach to modeling PFTs and focus on resolving the question of diatom–coccolithophore coexistence in the subpolar high-nitrate and low-chlorophyll regions. We choose an artificial neural network as our modeling framework because it has the potential to interpret complex nonlinear interactions governing complex adaptive systems, of which marine ecosystems are a prime example. Using ecological indicators that fulfill the criteria of measurability, sensitivity and specificity, we demonstrate that our diagnostic model correctly interprets some basic ecological rules similar to ones emerging from dynamic models. Our time series highlight a dynamic phyto-PFT community composition in all high-latitude areas and indicate seasonal coexistence of diatoms and coccolithophores. This observation, though consistent with in situ and remote sensing measurements, has so far not been captured by state-of-the-art dynamic models, which struggle to resolve this "paradox of the plankton". We conclude that an ecological indicator approach is useful for ecological modeling of phytoplankton and potentially higher trophic levels. Finally, we speculate that it could serve as a powerful tool in advancing ecosystem-based management of marine resources.
Pan-Arctic linkages between snow accumulation and growing-season air temperature, soil moisture and vegetation
Authors: Luus K. A. , Gel Y. , Lin J. C. , Kelly R. E. J. , Duguay C. R.
Published: November 2013

Abstract. Arctic field studies have indicated that the air temperature, soil moisture and vegetation at a site influence the quantity of snow accumulated, and that snow accumulation can alter growing-season soil moisture and vegetation. Climate change is predicted to bring about warmer air temperatures, greater snow accumulation and northward movements of the shrub and tree lines. Understanding the responses of northern environments to changes in snow and growing-season land surface characteristics requires: (1) insights into the present-day linkages between snow and growing-season land surface characteristics; and (2) the ability to continue to monitor these associations over time across the vast pan-Arctic. The objective of this study was therefore to examine the pan-Arctic (north of 60° N) linkages between two temporally distinct data products created from AMSR-E satellite passive microwave observations: GlobSnow snow water equivalent (SWE), and NTSG growing-season AMSR-E Land Parameters (air temperature, soil moisture and vegetation transmissivity). Due to the complex and interconnected nature of processes determining snow and growing-season land surface characteristics, these associations were analyzed using the modern nonparametric technique of alternating conditional expectations (ACE), as this approach does not impose a predefined analytic form. Findings indicate that regions with lower vegetation transmissivity (more biomass) at the start and end of the growing season tend to accumulate less snow at the start and end of the snow season, possibly due to interception and sublimation. Warmer air temperatures at the start and end of the growing season were associated with diminished snow accumulation at the start and end of the snow season. High latitude sites with warmer mean annual growing-season temperatures tended to accumulate more snow, probably due to the greater availability of water vapor for snow season precipitation at warmer locations. Regions with drier soils preceding snow onset tended to accumulate greater quantities of snow, likely because drier soils freeze faster and more thoroughly than wetter soils. Understanding and continuing to monitor these linkages at the regional scale using the ACE approach can allow insights to be gained into the complex response of Arctic ecosystems to climate-driven shifts in air temperature, vegetation, soil moisture and snow accumulation.
Benthic fluxes of dissolved organic nitrogen in the lower St. Lawrence estuary and implications for selective organic matter degradation
Authors: Alkhatib M. , del Giorgio P. A. , Gelinas Y. , Lehmann M. F.
Published: November 2013

Abstract. The distribution of dissolved organic nitrogen (DON) and carbon (DOC) in sediment porewaters was determined at nine locations along the St. Lawrence estuary and in the gulf of St. Lawrence. In a previous manuscript (Alkhatib et al., 2012a), we have shown that this study area is characterized by gradients in the sedimentary particulate organic matter (POM) reactivity, bottom water oxygen concentrations, and benthic respiration rates. Based on the porewater profiles, we estimated the benthic diffusive fluxes of DON and DOC in the same area. Our results show that DON fluxed out of the sediments at significant rates (110 to 430 μmol m−2 d−1). DON fluxes were positively correlated with sedimentary POM reactivity and varied inversely with sediment oxygen exposure time (OET), suggesting direct links between POM quality, aerobic remineralization and the release of DON to the water column. DON fluxes were on the order of 30 to 64% of the total benthic inorganic fixed N loss due to denitrification, and often exceeded the diffusive nitrate fluxes into the sediments. Hence they represented a large fraction of the total benthic N exchange, a result that is particularly important in light of the fact that DON fluxes are usually not accounted for in estuarine and coastal zone nutrient budgets. In contrast to DON, DOC fluxes out of the sediments did not show any significant spatial variation along the Laurentian Channel (LC) between the estuary and the gulf (2100 ± 100 μmol m−2 d−1). The molar C / N ratio of dissolved organic matter (DOM) in porewater and the overlying bottom water varied significantly along the transect, with lowest C / N in the lower estuary (5–6) and highest C / N (> 10) in the gulf. Large differences between the C / N ratios of porewater DOM and POM are mainly attributed to a combination of selective POM hydrolysis and elemental fractionation during subsequent DOM mineralization, but selective adsorption of DOM to mineral phases could not be excluded as a potential C / N fractionating process. The extent of this C- versus N- element partitioning seems to be linked to POM reactivity and redox conditions in the sediment porewaters. Our results thus highlight the variable effects selective organic matter (OM) preservation can have on bulk sedimentary C / N ratios, decoupling the primary source C / N signatures from those in sedimentary paleoenvironmental archives. Our study further underscores that the role of estuarine sediments as efficient sinks of bioavailable nitrogen is strongly influenced by the release of DON during early diagenetic reactions, and that DON fluxes from continental margin sediments represent an important internal source of N to the ocean.
A journey of a thousand miles begins with one small step – human agency, hydrological processes and time in socio-hydrology
Authors: Ertsen M. W. , Murphy J. T. , Purdue L. E. , Zhu T.
Published: November 2013

Abstract. When simulating social action in modeling efforts, as in socio-hydrology, an issue of obvious importance is how to ensure that social action by human agents is well-represented in the analysis and the model. Generally, human decision-making is either modeled on a yearly basis or lumped together as collective social structures. Both responses are problematic, as human decision making is more complex and organizations are the result of human agency and cannot be used as explanatory forces. A way out of the dilemma how to include human agency is to go to the largest societal and environmental clustering possible: society itself and climate, with time steps of years or decades. In the paper, the other way out is developed: to face human agency squarely, and direct the modeling approach to the human agency of individuals and couple this with the lowest appropriate hydrological level and time step. This approach is supported theoretically by the work of Bruno Latour, the French sociologist and philosopher. We discuss irrigation archaeology, as it is in this discipline that the issues of scale and explanatory force are well discussed. The issue is not just what scale to use: it is what scale matters. We argue that understanding the arrangements that permitted the management of irrigation over centuries, requires modeling and understanding the small-scale, day-to-day operations and personal interactions upon which they were built. This effort, however, must be informed by the longer-term dynamics as these provide the context within which human agency, is acted out.
Risk assessment of debris flow in Yushu seismic area in China: a perspective for the reconstruction
Authors: Lan H. X. , Li L. P. , Zhang Y. S. , Gao X. , Liu H. J.
Published: November 2013

Abstract. The 14 April 2010 Ms = 7.1 Yushu Earthquake (YE) had caused severe damage in the Jiegu township, the residential centre of Yushu Tibetan Autonomous Prefecture, Qinghai Province, China. In view of the fragile geological conditions after YE, risk assessment of secondary geohazards becomes an important concern for the reconstruction. A quantitative methodology was developed to assess the risk of debris flow by taking into account important intensity information. Debris flow scenarios were simulated with respect to rainfall events with 10, 50 and 100 yr returning period, respectively. The possible economic loss and fatalities caused by damage to buildings were assessed both in the settlement area and in the low hazard settlement area regarding the simulated debris flow events. Three modelled building types were adopted, i.e. hollow brick wood (HBW), hollow brick concrete (HBC) and reinforced concrete (RC) buildings. The results suggest that HBC structure achieves a good balance for the cost-benefit relationship compared with HBW and RC structures and thus could be an optimal choice for most of the new residential buildings in the Jiegu township. The low hazard boundary presents significant risk reduction efficiency in the 100 yr returning debris flow event. In addition, the societal risk for the settlement area is unacceptable when the 100 yr returning event occurs but reduces to ALARP (as low as reasonably practicable) level as the low hazard area is considered. Therefore, the low hazard area was highly recommended to be taken into account in the reconstruction. Yet, the societal risk might indeed approach an unacceptable level if one considers that YE has inevitably increased the occurrence frequency of debris flow. The quantitative results should be treated as a perspective for the reconstruction rather than precise numbers of future losses, owing to the complexity of the problem and the deficiency of data.
Correlation between quality of life and disease severity in children with atopic dermatitis in the State of Qatar
Authors: Al Bouainain Hessa , Allam Mohamed Ibrahim
Published: November 2013

Correlation between quality of life and disease severity in children with atopic dermatitis in the state of Qatar Background: Atopic dermatitis (AD) is an itchy, chronic or chronically relapsing, inflammatory skin condition which is most prevalent in childhood. It is known to affect 10-20% of children. The prevalence of AD has increased during the past 3 decades and is probably due to modification of lifestyles and environment. Atopic dermatitis (AD) can affect the behavior, life and development of children. Little is known regarding the effect of AD on the quality of life (QoL) in children of the Gulf region and especially in the state of Qatar. Objectives: To study the impact of AD on the QoL in children and its relation to disease severity in the state of Qatar. Methods: This study was conducted on 45 patients with atopic dermatitis aged from 5 to 16 years who attended the outpatient clinic of the Dermatology Department, Rummilah and Al Khor Hospitals, Hamad Medical Corporation, Doha, Qatar. The UK diagnostic criteria of AD were used for the diagnosis of atopic dermatitis. Disease severity was assessed using modified SCORAD (SCORing Atopic Dermatitis) measuring only objective criteria .The Children Dermatology Life Quality Index (CDLQI) was used to quantify the impact of AD on children's quality of life. SPSS 14.0 statistical package has been used for the analysis. Correlation coefficient (Pearson) was calculated to see associations between variables. Results: There were a positive significant correlation between objective SCORAD and each question from 1 to 10 as well as the total score of CDLQI except for question 2, the strongest relation between objective SCORAD and CDLQI was found in question 1 (symptoms) and question 9 (sleep). It was statistically evident that as the SCORAD index increases the CDLQI increases. Conclusion: The study has shown adverse effects of AD on children QoL especially on symptoms and feelings and a positive correlation between CDLQI and modified SCORAD which denote the effect of AD on the lives and development of children. We recommend the use of CDLQI in research work as an additional subjective measure to the clinical objective scoring tools used in chronic skin diseases. Health economists and caregivers should put the impact of skin diseases (non-life threatening diseases) on the QoL of patients, especially children and its implications for psychology, development, social functioning and school outcome.
Anti-allergic effects by arginase inhibitors: Role of nitric oxide
Authors: Meurs Herman , Sopi Ramadan , Simoons Mirjam , Jackson Paul , Maarsingh Harm
Published: November 2013

Anti-allergic effects by arginase inhibitors: role of nitric oxide Herman Meurs¹, Ramadan Sopi¹´², Mirjam Simoons¹, Paul Jackson³, Harm Maarsingh¹´³ ¹Department of Molecular Pharmacology, Groningen Research Institute for Pharmacy and Groningen Research Institute for Asthma and COPD, University of Groningen, Groningen, The Netherlands, ²Faculty of Medicine, University of Prishtina, Prishtina, Kosovo, ³Department of Pharmaceutical Sciences, Gregory School of Pharmacy, Palm Beach Atlantic University, West Palm Beach, FL, USA Using animal models for acute and chronic asthma, we demonstrated that inhaled arginase inhibitors attenuate allergen-induced early and late asthmatic reactions, airway hyperresponsiveness, airway inflammation and airway remodeling. Moreover, it was found that arginase inhibition greatly reduces the sensitivity of the airways to the inhaled allergen, suggesting that arginase inhibitors may have an anti-allergic effect by inhibition of mediator release from mast cells. Since arginase activity regulates nitric oxide (NO) synthesis via competition with NO synthase (NOS) for the common substrate L-arginine, and activation of mast cells is inhibited by NO, we hypothesized that the anti-allergic effect of arginase inhibition involves increased NO synthesis. This hypothesis was investigated in precision-cut lung slices from actively ovalbumin (OVA)-sensitized guinea pigs, by using video-assisted microscopy to measure allergen (OVA)-induced airway constriction. OVA induced a dose-dependent airway constriction with a mean maximal effect (Emax) of 98% and a mean EC50 of 0.039 µg/ml. The arginase inhibitor 2(S)-amino-6-boronohexanoic acid (ABH, 1 µM) significantly reduced the sensitivity towards OVA by >100-fold to 5 µg/ml, whereas the Emax of OVA was reduced to 50%. The effects of ABH were mimicked by the arginase inhibitor N?-hydroxy-nor-L-arginine (nor-NOHA, 5 µM). The NOS inhibitor N?-nitro-L-arginine methyl ester (L-NAME, 100 µM) largely reversed the inhibitory effect of ABH, indicating the involvement of NO. Remarkably, inhibition of arginase and/or NOS did not affect airway constriction towards exogenous histamine, the primary contractile mediator released by mast cells upon allergen challenge. This indicates that ABH reduces the histamine release from mast cells rather than the responsiveness to this mediator. In conclusion, inhibition of arginase greatly reduces airway responsiveness towards allergen by increased NO synthesis, most likely preventing mediator release from mast cells and subsequent airway constriction. Supported by the European Erasmus Mundus partnership JoinEU-SEE
Calcineurin-NFAT signaling pathway mediates NHE1 induced cardiac hypertrophy
Authors: Mlih Mohamed Salem
Published: November 2013

Calcineurin-NFAT Signaling Pathway Mediates NHE1 Induced Cardiac Hypertrophy Mohamed Mlih, Fatima Mraiche College of Pharmacy, Qatar University, Doha, Qatar In the myocardium, the Na+/H+ exchanger isoform 1 (NHE1), a plasma membrane protein that regulates intracellular pH has been shown to be critical in the development of cardiac hypertrophy. Inhibition of NHE1 activity/expression has previously been demonstrated to produce cardioprotective effects. Recent reports have reported that transgenic mice overexpressing active NHE1 developed spontaneous cardiac hypertrophy in association with elevated levels of osteopontin (OPN). Osteopontin is a secreted protein involved in many physiological pathways including bone formation, immune response, vascularization and cardiac hypertrophy. The physiological pathway in which active NHE1 induces OPN expression in the heart remains unknown. Recently, NHE1 was described as a key regulator of the calcineurin-NFAT pathway. The calcineurin-NFAT pathway is a hypertrophic pathway induced by intracellular increase in calcium concentration that induces NFAT translocation to the nucleus. In the nucleus, NFAT interacts with the transcription factor GATA-4 and together activate hypertrophic gene. Our hypothesis is that NHE1 through the calcineurin/Nfat pathway induces OPN expression leading to cardiac hypertrophy. To verify this hypothesis , rat cardiomyoblasts (H9c2 cells) were infected with activate NHE1 adenovirus in the presence and absence of a calcineurin inhibitor, FK506 . H9c2 cells infected with active NHE1 showed an increase of NHE1 activity (NHE1: 376.5%) and exhibit a 1.6 fold increase in cell area compared to the control, which was attenuated in the presence of FK506. Our preliminary results show that NHE1 activation increases osteopontin protein expression. In addition, H9c2 cells infected with active NHE1 also demonstrate a significant activation of the transcription factor GATA-4 (NHE1: 149% ±28% , p<0.05). The activation of GATA-4 induced by active NHE1 is inhibited by FK506 treatment. In conclusion, NHE1 through the calcineurin/NFAT pathway induces cardiac hypertrophy in H9c2 cells. This new finding will give us a better understanding of signaling pathway mediating NHE1 induced cardiac hypertrophy and allow us to identify alternative therapeutic targets for the treatment heart failure.
Intracranial aneurysm segmentation in 3D CT angiography
Authors: Dakua Sarada Prasad
Published: November 2013

Background & Objectives Aneurysm is a condition in which an abnormal dilation occurs in the wall of an artery or vein. Since cerebral aneurysm morphology is considered as a potential surrogate of rupture, clinicians often desire its segmentation before any pre-operative or interventional planning is performed. Also, segmentation of such images offers the potential of identifying the right treatment for a wide range of medical conundrums. This paper presents a simple and fast automatic algorithm based on active contour technique for cerebral aneurysm segmentation. Since the performance of active contour is highly dependent on the placement of the initial contour, the objective of this work is to automate this placement process to get the desired contour quickly. Methods: The active contour approach is a prime candidate for practical exploitation because active contours make effective use of specific prior information about objects and this makes them inherently efficient algorithms. In this work, we utilize gradient vector flow (GVF) snake, which is an extension of the active contour because it efficiently converges to boundary concavities. However, computational time remains a concern; therefore, we try to place the initial contour as close to the desired boundary of the object in the medical image as possible. For this, we use Otsu's adaptive thresholding method that is based on the histogram of the intensity distribution of the input image. As a post-processing step, the extracted contour is smoothened using linear regression. Results: The proposed method has been implemented on angiography datasets obtained from two different sources. The angiography CT datasets are collected from University of College of London and Hamad Medical Corporation (512x512x405 pixels at circa 0.5mm resolution). The original, ground truth and segmented intracranial aneurysms are shown in Figure 1, which clearly reflects the potential of the proposed algorithm. The average time taken for segmentation is 2 s per slice (without optimization) on MATLAB 7.5 on a PC with Pentium 4, 3 GHz dual core processor. Conclusion: Although our work might be a simplified approach, we envision that it could represent a necessary first step towards improving the performance of active contour that is dependent on the initial contour in a clinical setting.