bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on Direct Reduction of Vanadium Slag
Authors: Wang Neng Wei , Li Guo Wei , Fang Min Xian
Published: March 2015

In this paper the process of direct reduction of vanadium slag was adopted. The main factor was determined by uniform experimental design and single factor analysis, and then the optimum process condition was drawn by the test. The test results showed that the regression equation curve fitting of the experiment data was very significant, the main factors affecting the vanadium slag reduction (according to the primary and secondary order) was the content of anhydrous sodium carbonate, roasting temperature, roasting time and reduction of carbon content. The factors for the reduction of the optimum process conditions are the carbon coefficient 1.04, roasting temperature 1100°C, roasting reduction time 4h, 4% mass percent of anhydrous sodium carbonate and slag. Under the optimum conditions, the actual rate of weight loss and theory rate of weight were close to 0, the results could be reproduced, and the vanadium slag metallization rate was 75%~83%.
Characterization of Hot Deformation Behavior of TC18 Titanium Alloy
Authors: Yang Qing Chuan , Qiu Ke Hui , Jiang Ren Gui , Huang De Ming , He Hua Lin
Published: March 2015

In this work, hot compression tests on columniform TC18 titanium alloy specimens were performed with a Gleeble® 3500 thermal and mechanical simulator in the temperature range of 820-875 °C and at constant strain rates of 0.01, 0.1 and 1 s−1. Relationship model of true stress versus true strain as well as peak stress versus deformation temperature were established, and microstructural micrographs of TC18 titanium alloy were analyzed. The results showed that the flow stress decreased as the deformation temperature increased or the strain rate decreased. Besides, the deformation resistance at temperature above Tβ (β transus temperature) was obviously lower than that at below Tβ. In addition, flow stresses kept almost constant when it deformed in β region where hot deformation mechanism is DRV, but significant flow softening occurred in α+β region, where deformation mechanism is mainly dominated by DRX. And in α+β region, DRX is prone to occur at a low strain rate, and it is difficult for DRX to occur at high strain rate.
Study on the Magnetic Properties and Microstructure of Single-Stage Hot-Deformed Nd-Fe-B Magnets
Authors: Ma Yi Long , Shen Qian , Zhou An Ruo , Sun Jian Chun , Li Chun Hong , Chen Deng Ming
Published: March 2015

The Nd-Fe-B powder was prepared to bulk by cold pressing, and then was hot-deformed by the vacuum hot-pressing machine. Effects of hot-deformation temperature and rate on the density, anisotropy, performance and microstructure were studied. The results showed that the grain size was small, but the density and orientation degree was low, thus leading to poor performance when the deformation temperature was too low or deformation rate was too large. When the temperature was higher than 750 °C or the rate was lower than 0.1mm/s, the anisotropic magnets with good density and texture could be obtained. However, the magnetic properties of hot-deformed magnets deteriorated due to the present of coarse grains. From the microstructure of hot-deformed magnets it could be seen that there were plenty of coarse and irregular grains, which have a higher Nd content than the plate-like grains. The optimum magnetic properties could be obtained at deformation temperature of 700 °C and rate of 0.1 mm/s.
Corneal Matrix Repair Carrier with Composite Silk Protein Membrane
Authors: Zhang Shan Shan , Li Jiao Jiao , Zhang Xiao Feng , Lu Shen Zhou
Published: March 2015

Corneal transplantation is the only effective way to repair the damaged corneal tissue and solve the problem of insufficient donor cornea and immune rejection. Biocompatibility and stable transparent are necessary conditions of corneal stromal cells carrier. In this paper, the acetamide/silk (AC/SF) composite membranes are studied to be applied in corneal repair material. AC/SF membranes with different blending proportions had stable transparency, good cell compatibility. X-ray diffraction was used to investigate the structure of the composite films. The acetamide inhibited the formation of large crystalline particles, changed the crystal structure of silk fibroin and made the random coil structure convert to Silk I or Silk II. Therefore, acetamide was not only crosslinking agent but also crystallization inhibitor. The corneal stromal cells were seeded on sterilized composite membranes. After 5 h, the adhesion rate of stromal cells was more than 90%, cell could proliferate regularly on the composite membrane. There was no obvious difference in contrast to control plate. These results demonstrated that the composite membrane could promote corneal stromal cell proliferation.
Preparation of Collagen/Hydroxyapatite Composite Coating on Porous Titanium Substrate and its Cellular Response
Authors: Li Ting , Li Jin Shan , Kou Hong Chao , Li Fu Ping , Lu Ting Li
Published: March 2015

In this article, the layered deposition method is adopted to prepare the collagen/hydroxyapatite (COL/HA) composite coating. The morphology and elements of the COL/HA composite coating are observed using a scanning electron microscope (SEM) with an energy dispersive spectrometer (EDS), the optical density (O.D.) values are obtained by MTT assay to assess the cellular viabilityof composite coating. The experimental results showed that the addition of collagen not only improve the bonding strength of composite coating and porous titanium substrate, but also combine the osteoconduction of inorganic coating HA and the osteoinduction of organic coating COL, effectively enhance the cellular adhesion, proliferation and differentiation. The cellular viability cultured in COL/HA composite coating is much higher than the pure HA modified coating.
Chirality Synthesis of N-Shaped ZnO Nanorods by Glacial Acetic Acid Assisted Annealing Process and Ethanol Sensing Properties
Authors: Yang Zao , Liu Quan Hui , Wang Tai Hong , Wang Yun Bing
Published: March 2015

N-shaped ZnO nanorods were first chirality synthesized by glacial acetic acid assisted annealing process. X-ray powder diffraction results show that these nanorods are of ZnO wurtzite-structure. These nanorods grow from a thin platelet base and are parallel to each other to form n-shaped ZnO nanorods. The width of thin platelet bases range from 50 to 130 nm. The diameters of the nanorods rang from 25 to 60nm, and their lengths are 0.2—0.6um. Gas sensors fabricated from these n-shaped ZnO nanorods show a very high sensitivity to ethanol gas and the sensitivity is up to about 35 against 1000 ppm ethanol gas at the operating temperature of 300°C.
Phase Compositions of a Mg-Dy-Zn Alloy Containing LPSO Structures
Authors: Cai Xue Cheng , Peng Qiu Ming , Fang Da Qing
Published: March 2015

The phase compositions of a Mg-2Dy-0.5Zn (at.%) alloy under different solid solution temperature was investigated by differential thermal analysis (DSC), X-ray diffraction (XRD), optical microscope (OM), scanning electron microscope (SEM) and transmission electron microscope (TEM). The results indicated that the as-cast sample was mainly composed of an 18R long period stacking ordered (LPSO) phase and Mg matrix. The disappearance of 18R-LPSO phase, together with the presence of 14H-LPSO phase, occurred when solid solution treatment (SST) was at 535 °C. When the temperature was higher than 535 °C, the 18R-LPSO phase was detected again companied with a new Mg8ZnDy eutectic phase.
Preparation and Mechanical Properties of Poly (arylene sulfide sulfone)/Glass Fiber Cloth Composites
Authors: Kong Yu , Yang Jia Cao , Wang Xiao Jun , Zhang Gang , Long Sheng Ru , Yang Jie
Published: March 2015

Poly (arylene sulfide sulfone)/glass fiber cloth composites (PASS/GFC) were prepared through compression moulding. The optimum processing conditions including temperature, time and pressure were discussed in detail. The cross-linking reaction, mechanical and dynamic mechanical properties were also characterized. The results showed that the optimum processing temperature, pressure and time were 325 °C, 5 MPa and 15 min, respectively. The thioether group (-S-) was oxidized and converted to sulfoxide (-SO-) and sulfone (-SO2-) groups during the crosslinking reaction proved by Fourier transform infrared spectrometer. The mechanical and dynamic mechanical analysis measurements showed that mechanical properties, including tensile, bending, impact and storage modulus increased continuously with an increase of the GFC contents.
Effect of Plasticizer (DOP) on Cell Structure and Mechanical Properties of Extrusion-Foamed PVC Sheet
Authors: Wang Ming Yi , Zhou Nan Qiao , Hu Jun
Published: March 2015

Using supercritical CO2 as the foaming agent, rigid polyvinyl chloride (R-PVC) foam sheets were prepared in a continuous extrusion foaming system. The effects of dioctyl phthalate (DOP) on the rheological properties of PVC were investigated using a Brabender torque rheometer while other basic formula remained unchanged. The influences of DOP content on microstructure, mechanical properties and density of PVC micro foamed sheet were investigated with scanning electron microscopy (SEM). The results showed that the addition of DOP resulted in increased flexibility and the elongation at break of the foamed PVC sheet, while the mechanical properties of foamed PVC sheet decreased with the increase of DOP content, implying that excessive addition of DOP will cause gas escape and bubble coalescence in the foaming process. Low density PVC foam sheets with fine cell morphology were obtained when 2 phr DOP was added in PVCformula.
Graphene–Epoxy Composites with High Dielectric Constant Prepared by Cryomilling
Authors: Hou Qing , Fan Run Hua , Zhang Zi Dong , Yan Ke Lan , Cheng Chuan Bing , Chen Min , Sun Kai , Liu Gui Fang , Xie Pei Tao
Published: March 2015

The microstructure and dielectric properties of the graphene–epoxy composites prepared by cryomilling at liquid nitrogen temperature were studied by SEM and RF impedance material analyzer. The result indicated that both the dielectric constant and conductivity of the composites increased with the increase of the graphene content. The value of the dielectric constant of the composite with about 8 wt % of graphene was as high as 200. Moreover, the frequency dispersion behaviors of the conductivity within a certain frequency range accorded with the Jonscher's power law demonstrating that the conductive mechanism is hopping conduction. The negative reactance decreased with the increase of the testing frequency which indicated a capacitive character
Impurity Detection Method for High-Purity BCl3
Authors: Shi Yi Ni , Pei Kai , Zhao Yin Feng , Tan Yun , Tai Zhen , Zhang Lin , Ji Yan Qiu
Published: March 2015

A method for detecting impurities in high purity BCl3 was described in the present work. GC, ICP-MS, FTIR and colorimetric method were applied to analyze high-purity BCl3. The quantitative results of the impurities such as N2, CO, CO2 and Fe demonstrated that these methods had excellent repeatability (RSD<3%), reproducibility. The ICP-MS detection accuracy can achieve ppb limiter. The FTIR method provided opportunities for the determination of HCl, COCl2, which have difficulties in quantification with other method.
The Effect of Short-Term Musical Training on Speech Perception in Noise
Authors: Jain Chandni , Mohamed Hijas , Kumar U. Ajith
Published: March 2015

The aim of the study was to assess the effect of short-term musical training on speech perception in noise. In the present study speech perception in noise was measured pre- and post- short-term musical training. The musical training involved auditory perceptual training for raga identification of two Carnatic ragas. The training was given for eight sessions. A total of 18 normal hearing adults in the age range of 18-25 years participated in the study wherein group 1 consisted of ten individuals who underwent musical training and group 2 consisted of eight individuals who did not undergo any training. Results revealed that post training, speech perception in noise improved significantly in group 1, whereas group 2 did not show any changes in speech perception scores. Thus, short-term musical training shows an enhancement of speech perception in the presence of noise. However, generalization and long-term maintenance of these benefits needs to be evaluated.
The Impact of Chlorhexidine Mouth Rinse on the Bond Strength of Polycarbonate Orthodontic Brackets
Authors: Anil Sukumaran , Hussein Farouk Ahmed , Hashem Mohammed Ibrahim , Chalisserry Elna P
Published: March 2015

Objective

The purpose of the current in-vivo study was to assess the effect of using 0.12% chlorhexidine (CHX) mouth rinse, before bonding, on shear bond strength of polycarbonate brackets bonded with composite adhesive.

Subjects and methods

Eighteen orthodontic patients with a mean age 21.41 ± 1.2 years, who were scheduled to have 2 or more first premolars extracted, were included in this study. Patients were referred for an oral prophylaxis program which included, in part, the use of a mouth rinse. Patients were divided into 2 groups, a test group of 9 patients who used 0.12% CHX gluconate mouth rinse twice daily and a control group of 9 patients who used a mouth rinse without CHX, but with same color. After 1 week, polycarbonate brackets were bonded to first premolars with Transbond XT composite adhesive. Premolars were extracted after 28 days and tested for shear bond strength on a universal testing machine. Student's t-test was used to compare shear bond strengths of both groups.

Results

No statistically significant difference was found in bond strengths’ values between both groups. The test group (with CHX) has mean shear bond strength of 14.21 ± 2.42 MPa whereas the control group (without CHX) revealed a mean strength of 14.52 ± 2.31 MPa.

Conclusion

The use of 0.12% CHX mouth rinse, for one week before bonding, did not affect the shear bond strength of polycarbonate brackets bonded with Transbond composite. Furthermore, these brackets showed clinically acceptable bond strength.

How to cite this article

Hussein FA, Hashem MI, Chalisserry EP, Anil S. The Impact of Chlorhexidine Mouth Rinse on the Bond Strength of Polycarbonate Orthodontic Brackets. J Contemp Dent Pract 2014;15(6):688-692.
Mandibular First Molar with Vertucci Type I Canal Configuration diagnosed with the Help of Cone Beam Computed Tomography: A Rare Case Report
Authors: Agarwal Manoj , Trivedi HP , Gaur Ankit , Gupta Manju , Sharma Anuradha , Likhyani Lalit
Published: March 2015

The knowledge of root canal morphology and the existing anatomical variations is essential for successful endodontic therapy. This report presents an extraordinary case of unusual tooth morphology involving the mandibular first molar with a single root and a single canal in a patient. Endodontic treatment of the affected tooth 36 was performed. Cone beam computed tomography (CBCT) images confirmed our diagnostic and therapeutic measures after endodontic management of the teeth. This morphologic variation has been reported once in the literature. The availability of three-dimensional images further provided the opportunity for the precise description of the anatomy of mandibular first molar with single roots and single canals.

How to cite this article

Gaur A, Trivedi HP, Gupta M, Sharma A, Likhyani L, Agarwal M. Mandibular First Molar with Vertucci Type I Canal Configuration diagnosed with the Help of Cone Beam Computed Tomography: A Rare Case Report. J Contemp Dent Pract 2014;15(6):784-787.
Osseointegrated Silicone Finger Prosthesis using Dental Implants: A Renovated Technique
Authors: Vinnakota Dileep Nag , Sankar V Vijay , Chirumamilla Naveen , Reddy V Vamsikrishna
Published: March 2015

Aim and background

In clinical practice, we come across patients with traumatically amputated or congenitally missing partial or complete fingers that can be restored using microsurgical replantation or transplantation procedures. However, in some cases this might not be possible due to systemic or local factors and the lost or missing part has to be replaced prosthetically to offer psychological and functional wellbeing. These prostheses can be constructed with various materials like acrylics or silicone retained with the help of auxiliary aids. However, these prostheses cause some hindrance in performing functions like writing, typing, etc. The aim of the present trial was to ameliorate the existing design of implant supported finger prosthesis.

Technique

Distal phalange of middle finger replaced with implant supported silicone finger prosthesis is modified by utilizing a metal framework to support silicone material to improve rigidity while working.

Conclusion and clinical significance

We could achieve a good function, esthetics and tactile sensibility with this modified design. Whenever, feasible this design can improve the performance and patients feel a deep sense of satisfaction and improved self-esteem with this modified prosthesis.

How to cite this article

Vinnakota DN, Sankar VV, Chirumamilla N, Reddy VV. Osseointegrated Silicone Finger Prosthesis using Dental Implants: A Renovated Technique. J Contemp Dent Pract 2014;15(6):818-820.
Modifying Gummy Smile: A Minimally Invasive Approach
Authors: Abdullah Walid Ahmed , Khalil Hesham S , Alhindi Maryam M , Marzook Hamdy
Published: March 2015

Aim

Excessive gingival display is a problem that can be managed by variety of procedures. These procedures include non-surgical and surgical methods. The underlying cause of gummy smile can affect the type of procedure to be selected. Most patients prefer minimally invasive procedures with outstanding results. The authors describe a minimally invasive lip repositioning technique for management of gummy smile.

Materials and methods

Twelve patients (10 females, 2 males) with gingival display of 4 mm or more were operated under local anesthesia using a modified lip repositioning technique. Patients were followed up for 1, 3, 6 and 12 months and gingival display was measured at each follow up visit. The gingival mucosa was dissected and levator labii superioris and depressor septi muscles were freed and repositioned in a lower position. The levator labii superioris muscles were pulled in a lower position using circumdental sutures for 10 days. Both surgeon's and patient's satisfaction of surgical outcome was recorded at each follow-up visit.

Results

At early stage of follow-up the main complaints of patients were the feeling of tension in the upper lip and circum oral area, mild pain which was managed with analgesics. One month postoperatively, the gingival display in all patients was recorded to be between 2 and 4 mm with a mean of (2.6 mm). Patient satisfaction records after 1 month showed that 10 patients were satisfied with the results. Three months postoperatively, the gingival display in all patients was recorded and found to be between 2 and 5 mm with a mean of 3 mm. Patient satisfaction records showed that 8 patients were satisfied with the results as they gave scores between. Surgeon's satisfaction at three months follow up showed that the surgeons were satisfied in 8 patients. The same results were found in the 6 and 12 months follow-up periods without any changes. Complete relapse was recorded only in one case at the third postoperative month.

Conclusion

This study showed that the proposed lip repositioning technique is an acceptable minimally invasive procedure in managing gummy smile.

Clinical significance

A non-invasive procedure to avoid other complicated surgical procedures.

How to cite this article

Abdullah WA, Khalil HS, Alhindi MM, Marzook H. Modifying Gummy Smile: A Minimally Invasive Approach. J Contemp Dent Pract 2014;15(6):821-826.
Sources and contributions of wood smoke during winter in London: assessing local and regional influences
Authors: Crilley L. R. , Bloss W. J. , Yin J. , Beddows D. C. S. , Harrison R. M. , Allan J. D. , Young D. E. , Flynn M. , Williams P. , Zotter P. , Prevot A. S. H. , Heal M. R. , Barlow J. F. , Halios C. H. , Lee J. D. , Szidat S. , Mohr C.
Published: March 2015

Abstract. Determining the contribution of wood smoke to air pollution in large cities such as London is becoming increasingly important due to the changing nature of domestic heating in urban areas. During winter, biomass burning emissions have been identified as a major cause of exceedances of European air quality limits. The aim of this work was to quantify the contribution of biomass burning in London to concentrations of PM2.5 and determine whether local emissions or regional contributions were the main source of biomass smoke. To achieve this, a number of biomass burning chemical tracers were analysed at a site within central London and two sites in surrounding rural areas. Concentrations of levoglucosan, elemental carbon (EC), organic carbon (OC) and K+ were generally well correlated across the three sites. At all the sites, biomass burning was found to be a source of OC and EC, with the largest contribution of EC from traffic emissions, while for OC the dominant fraction included contributions from secondary organic aerosols, primary biogenic and cooking sources. Source apportionment of the EC and OC was found to give reasonable estimation of the total carbon from non-fossil and fossil fuel sources based upon comparison with estimates derived from 14C analysis. Aethalometer-derived black carbon data were also apportioned into the contributions from biomass burning and traffic and showed trends similar to those observed for EC. Mean wood smoke mass at the sites was estimated to range from 0.78 to 1.0 μg m−3 during the campaign in January–February 2012. Measurements on a 160 m tower in London suggested a similar ratio of brown to black carbon (reflecting wood burning and traffic respectively) in regional and London air. Peaks in the levoglucosan and K+ concentrations were observed to coincide with low ambient temperature, consistent with domestic heating as a major contributing local source in London. Overall, the source of biomass smoke in London was concluded to be a background regional source overlaid by contributions from local domestic burning emissions. This could have implications when considering future emission control strategies during winter and may be the focus of future work in order to better determine the contributing local sources.
A novel inlet system for online chemical analysis of semi-volatile submicron particulate matter
Authors: Eichler P. , Müller M. , D'Anna B. , Wisthaler A.
Published: March 2015

Abstract. We herein present a novel modular inlet system designed to be coupled to low-pressure gas analyzers for online chemical characterization of semi-volatile submicron particles. The "chemical analysis of aerosol online" (CHARON) inlet consists of a gas-phase denuder for stripping off gas-phase analytes, an aerodynamic lens for particle collimation combined with an inertial sampler for the particle-enriched flow and a thermodesorption unit for particle volatilization prior to chemical analysis. The denuder was measured to remove gas-phase organics with an efficiency > 99.999% and to transmit particles in the 100–750 nm size range with a 75–90% efficiency. The measured average particle enrichment factor in the subsampling flow from the aerodynamic lens was 25.6, which is a factor of 3 lower than the calculated theoretical optimum. We coupled the CHARON inlet to a proton-transfer-reaction time-of-flight mass spectrometer (PTR-ToF-MS) which quantitatively detects most organic analytes and ammonia. The combined CHARON-PTR-ToF-MS setup is thus capable of measuring both the organic and the ammonium fraction in submicron particles in real time. Individual organic compounds can be detected down to levels of 10–20 ng m−3. Two proof-of-principle studies were carried out for demonstrating the analytical power of this new instrumental setup: (i) oxygenated organics and their partitioning between the gas and the particulate phase were observed from the reaction of limonene with ozone and (ii) nicotine was measured in cigarette smoke particles demonstrating that selected organic target compounds can be detected in submicron particles in real time.
A spectral method for discriminating thermodynamic phase and retrieving cloud optical thickness and effective radius using transmitted solar radiance spectra
Authors: LeBlanc S. E. , Pilewskie P. , Schmidt K. S. , Coddington O.
Published: March 2015

Abstract. A new retrieval scheme for cloud optical thickness, effective radius, and thermodynamic phase was developed for ground-based measurements of cloud shortwave solar spectral transmittance. Fifteen parameters were derived to quantify spectral variations in shortwave transmittance due to absorption and scattering of liquid water and ice clouds, manifested by shifts in spectral slopes, curvatures, maxima, and minima. To retrieve cloud optical thickness and effective particle radius, a weighted least square fit that matched the modeled parameters was applied. The measurements for this analysis were made with the ground-based Solar Spectral Flux Radiometer in Boulder, Colorado, between May 2012 and January 2013. We compared the cloud optical thickness and effective radius from the new retrieval to two other retrieval methods. By using multiple spectral features, we find a closer fit (with a root mean square difference over the entire spectra of 3.1% for a liquid water cloud and 5.9% for an ice cloud) between measured and modeled spectra compared to two other retrieval methods which diverge by a root mean square of up to 6.4% for a liquid water cloud and 22.5% for an ice cloud. The new retrieval introduced here has an average uncertainty in effective radius (± 1.2 μm) smaller by factor of at least 2.5 than two other methods when applied to an ice cloud.
Forests, savannas, and grasslands: bridging the knowledge gap between ecology and Dynamic Global Vegetation Models
Authors: Baudena M. , Dekker S. C. , van Bodegom P. M. , Cuesta B. , Higgins S. I. , Lehsten V. , Reick C. H. , Rietkerk M. , Scheiter S. , Yin Z. , Zavala M. A. , Brovkin V.
Published: March 2015

Abstract. The forest, savanna, and grassland biomes, and the transitions between them, are expected to undergo major changes in the future due to global climate change. Dynamic global vegetation models (DGVMs) are very useful for understanding vegetation dynamics under the present climate, and for predicting its changes under future conditions. However, several DGVMs display high uncertainty in predicting vegetation in tropical areas. Here we perform a comparative analysis of three different DGVMs (JSBACH, LPJ-GUESS-SPITFIRE and aDGVM) with regard to their representation of the ecological mechanisms and feedbacks that determine the forest, savanna, and grassland biomes, in an attempt to bridge the knowledge gap between ecology and global modeling. The outcomes of the models, which include different mechanisms, are compared to observed tree cover along a mean annual precipitation gradient in Africa. By drawing on the large number of recent studies that have delivered new insights into the ecology of tropical ecosystems in general, and of savannas in particular, we identify two main mechanisms that need improved representation in the examined DGVMs. The first mechanism includes water limitation to tree growth, and tree–grass competition for water, which are key factors in determining savanna presence in arid and semi-arid areas. The second is a grass–fire feedback, which maintains both forest and savanna presence in mesic areas. Grasses constitute the majority of the fuel load, and at the same time benefit from the openness of the landscape after fires, since they recover faster than trees. Additionally, these two mechanisms are better represented when the models also include tree life stages (adults and seedlings), and distinguish between fire-prone and shade-tolerant forest trees, and fire-resistant and shade-intolerant savanna trees. Including these basic elements could improve the predictive ability of the DGVMs, not only under current climate conditions but also and especially under future scenarios.
Generalized background error covariance matrix model (GEN_BE v2.0)
Authors: Descombes G. , Auligné T. , Vandenberghe F. , Barker D. M. , Barré J.
Published: March 2015

Abstract. The specification of state background error statistics is a key component of data assimilation since it affects the impact observations will have on the analysis. In the variational data assimilation approach, applied in geophysical sciences, the dimensions of the background error covariance matrix (B) are usually too large to be explicitly determined and B needs to be modeled. Recent efforts to include new variables in the analysis such as cloud parameters and chemical species have required the development of the code to GENerate the Background Errors (GEN_BE) version 2.0 for the Weather Research and Forecasting (WRF) community model. GEN_BE allows for a simpler, flexible, robust, and community-oriented framework that gathers methods used by some meteorological operational centers and researchers. We present the advantages of this new design for the data assimilation community by performing benchmarks of different modeling of B and showing some of the new features in data assimilation test cases. As data assimilation for clouds remains a challenge, we present a multivariate approach that includes hydrometeors in the control variables and new correlated errors. In addition, the GEN_BE v2.0 code is employed to diagnose error parameter statistics for chemical species, which shows that it is a tool flexible enough to implement new control variables. While the generation of the background errors statistics code was first developed for atmospheric research, the new version (GEN_BE v2.0) can be easily applied to other domains of science and chosen to diagnose and model B. Initially developed for variational data assimilation, the model of the B matrix may be useful for variational ensemble hybrid methods as well.
Technical Note: Watershed strategy for oceanic mesoscale eddy splitting
Authors: Li Q. Y. , Sun L.
Published: March 2015

Abstract. To identify oceanic mononuclear mesoscale eddies, a threshold-free splitting method was developed based on the watershed. Because oceanic eddies are similar to plateaus and basins in the map of the sea level anomaly (SLA) data, the natural divisions of the basins are the watersheds between them. The splitting algorithm is based on identifying these watersheds by finding the path of steepest descent. Compared to previous splitting methods, the proposed splitting algorithm has some advantages. First, there are no artificial parameters. Second, the algorithm is robust; the splitting strategy is independent of the algorithm and procedure and automatically guarantees that the split mononuclear eddies are simply connected pixel sets. Third, the new method is very fast, and the time complexity is O(N), where N is the number of multinuclear eddy pixels; each pixel is scanned only once for splitting, regardless of how many extremes there are. Fourth, the algorithm is independent of parameters; the strategy can potentially be applied to any possible physical parameters (e.g. SLA, geostrophic potential vorticity, Okubo–Weiss parameter). Besides, the present strategy can also be applied to automatic identification of troughs and ridges from weather charts. Because this general method can be applied to a variety of eddy parameter fields, we denoted it the Universal Splitting Technology for Circulations (USTC) method.
New electronic apex locator Romiapex A-15 presented accuracy for working length determination in permanent teeth
Authors: Maia Filho Etevaldo Matos , Rizzi Cláudia de Castro , Oliveira Daniela Silva Barroso de , Filho Paulo Nelson , Silva Raquel Assed Bezerra da , Silva Léa Assed Bezerra da
Published: March 2015

Purpose: The present study aims to evaluate, ex vivo, the accuracy of electronic apex locators Root ZX II and Romiapex-15, for working length (WL) determination in permanent teeth. Materials and Methods: Fourteen single-rooted teeth (incisors and canines), with their apices fully formed were used. The dental crowns were removed. The anatomic length of the tooth (real measurement) was visually determined through the insertion of a size 10 K-file until the tip of the instrument could be observed in the apical foramen under a microscope (20X). Teeth were fixed in a model of resin and adapted into alginate soaked with saline solution, which was used as an  electrical conductor. Using a K-file, root canals were measured electronically using both devices. The results obtained for each apex locator were compared to the real measurements. The accuracy between the devices was statistically analyzed using the Bland-Altman graph, Intraclass Correlation Coefficient (ICC), and Student’s t-test. Results: The mean difference between the measurements using the Root ZX II was 0.277mm greater than the real measurement, while the measurements from the Romiapex-15 were 0.308mm higher on average. The comparison between Root ZX II and Romiapex-15 had no significant difference (p= 0.868). Conclusion: It was concluded that Root ZX II and Romiapex-15 had similar accuracy. Romiapex-15 could be an option for WL determination in permanent teeth.
Cinéma et imaginaire social en venant de Ricœur
Authors: Lelièvre Samuel
Published: March 2015

Le cinéma peut être considéré comme un exemple particulièrement pertinent et instructif d’un discours et d’une pratique rapportables à chacun des trois grands domaines de l’imagination selon Ricœur – discours, articulation entre un niveau théorique et un niveau pratique, et imaginaire social. Tout en ayant pour objectif de se concentrer sur ce dernier niveau, une approche plus complète des notions de récit filmique et d’imaginaire social en venant de Ricœur requiert de traverser de nouveau les deux autres niveaux. Il est notamment nécessaire de retrouver les termes d’une philosophie ricœurienne de l’imagination dans l’articulation entre mise en intrigue et représentation qui s’opère depuis Temps et récit et une approche ultérieure de la notion de récit filmique. Un rapport critique à l’imaginaire social et politique peut finalement être retrouvé à travers le cinéma. Il s’agit toutefois de comprendre le passage d’un positionnement critique hérité de la tradition philosophique à un mouvement critique interne aux pratiques cinématographiques: tout en prenant en compte la notion de récit, ce mouvement critique peut mettre en avant, de manière nouvelle, la notion d’image, contribuant à sa revalorisation au sein d’une philosophie de l’imagination. La dernière partie de cet article s’intéresse notamment au rapport privilégié entre cinéma et historicité.
Teaching Nazi Culture
Authors: Parmalee Patty Lee
Published: March 2015

Nazi Culture would seem at first to be a very esoteric subject to teach to the rather practical-minded and not very cosmopolitan students of a northern New Jersey state college. But of course it is really a distancing technique, a Verfremdungseffekt a la Brecht. Teaching fascism is not really teaching fascism per se, but an angle for teaching capitalism and socialism. And teaching Nazi culture is an angle for teaching some of the purposes of capitalist ideology.
Poetry of the Colorado Miners: 1903-1906
Authors: Tannacito Dan
Published: March 2015

The poetry published in the Miners Magazine during the first decade of this century provides us with an illuminating case study of the characteristics and development of working-class literature in the United States. The creation of poetry by nonferrous metal miners in Colorado and surrounding areas illustrates the need for expression, affirmation, and communication on the part of the workers themselves and their allies during times of struggle.
Teaching Outside One’s Race: The Story of an Oakland Teacher
Authors: Picower Bree
Published: March 2015

“Oh, the District placed you at Prescott Elementary?  You better watch out ‒ they hate white people.  Especially that Carrie Secret ‒ she’s one of those black radicals, you know, the Ebonics people.”  This was the warning I was given multiple times in multiple ways when people found out that I had been assigned to Prescott Elementary School for my first teaching position, in Oakland, California in 1999.  The “warners” were other white folks who were trying to protect what they saw as a young, new teacher from what they perceived to be a hostile place.   However, I really didn’t fit the stereotype.  I had been involved with several organizations that explicitly addressed issues of race and education for several years, often as the only white person there.  I was thrilled to be placed at a school such as Prescott, whose reputation for high achievement for African American children and adoption of the “Ebonics” program had placed it at the forefront of national debate.
A Radical Critique of the Learning Outcomes Assessment Movement
Authors: Bennett Michael , Brady Jacqueline
Published: March 2015

The Learning Outcomes Assessment (LOA) movement seems rather innocuous.  Teachers and administrators at colleges and universities are asked to articulate the goals, objectives, measures, and outcomes of the educational process at every level:  from the classroom to the department to the institution as a whole.  Educators engage in this process with the help of curriculum mapping or educational matrices or a host of other tools and templates provided by any number of readily available frameworks (see the website of the National Institute for Learning Outcomes Assessment for many examples).  The information gathered is then used to evaluate curricula, programs, instructors, and institutions for purposes of internal review and external evaluation.
Contributors' Notes
Authors: Vogt Leonard
Published: March 2015

Information about contributors to Radical Teacher 100.
Assessment of Modifications in Thickness, Curvatures, and Volume upon the Cornea Caused by Disposable Soft Contact Lens Wear
Authors: Del Águila-Carrasco Antonio J. , Domínguez-Vicent Alberto , Pérez-Vives Cari , Ferrer-Blasco Teresa , Montés-Micó Robert
Published: March 2015

Purpose

To assess the effect of different disposable soft contact lenses on several corneal parameters–-thickness, anterior and posterior curvature, and volume–-by means of a Scheimpflug imaging-based device (Pentacam HR). Diurnal variations of these parameters were taken into account.

Methods

Twenty-one young, healthy subjects wore 4 different types of daily disposable soft contact lenses on 4 different days: Dailies AquaComfort Plus, SofLens, Dailies Total1, and Acuvue TruEye. The lenses had different material and water content. Pachymetry and curvature maps and corneal volume values were obtained using the Pentacam HR twice a day: one before putting the lens on and one after an 8-hour period of contact lens wear. Measurements were also taken without any contact lenses being worn.

Results

Regarding corneal thickness, the lens with the most similar behavior to the naked eye scenario was the Dailies Total1, causing a thickening of 0.2 ± 0.1% in the central zone and 0.6 ± 0.2% in the periphery. All 4 lenses caused a slight but not significant flattening in the anterior corneal curvature, whereas the posterior corneal curvature only experienced a significant but small steepening with the SofLens. The use of these lenses increased corneal volume slightly.

Conclusions

Variations in corneal parameters seem to depend on the type of contact lens used (material, oxygen transmissibility, water content). However, the magnitude of the changes introduced by the use of soft contact lenses over the 8-hour period was small and probably not large enough to influence either visual acuity or comfort.
Intravitreal Dexamethasone Implant for Cystoid Macular Edema and Inflammation after Scleral Buckling
Authors: Bonfiglio Vincenza , Fallico Matteo R. , Russo Andrea , De Grande Vittorio , Longo Antonio , Uva Maurizio G. , Reibaldi Michele , Avitabile Teresio
Published: March 2015

Purpose

Cystoid macular edema may occur following scleral buckling and therefore deteriorate the visual outcome. Inflammation may be the major causative factor in the development of postoperative cystoid macular edema. This case demonstrates the effectiveness of a dexamethasone implant as a treatment after the onset of choroidal inflammation and cystoid macular edema 6 months following scleral buckling and having visual acuity restored.

Methods

A 59-year-old phakic woman treated with scleral buckling for macula-off retinal detachment presented 2 months after surgery with cystoid macular edema with choroidal inflammation. Optical coherence tomography and fluorescein angiography were performed. From the time of the diagnosis, the patient's condition had been nonresponsive to medical therapy and only partially responsive to sub-Tenon triamcinolone acetonide. An intravitreal implant with a sustained release of 0.7 mg dexamethasone was implanted.

Results

Following an intravitreal injection with a dexamethasone implant, the macular edema subsided completely and optical coherence tomography showed decreased foveal thickness from 510 μm to 220 μm. Choroidal fluorescein leakage disappeared. Best-corrected visual acuity improved from 0.70 to 0.20 logMAR, a condition maintained throughout the 6 months of follow-up.

Conclusions

Cystoid macular edema and choroidal inflammation are difficult to treat, but the improvement observed in this case of post scleral buckling macular edema and choroidal inflammation showed how a dexamethasone implant proved to be useful during the 6-month follow-up.
Unique Genomic Profile Associated with Pediatric Uveal Melanoma
Authors: Blasi Maria Antonietta , Orteschi Daniela , Pagliara Monica M. , Coco Giulia , Asaro Alessia , Mulè Antonino , Petrone Gianluigi , Zollino Marcella
Published: March 2015

Purpose

To determine genetic features of a pediatric uveal melanoma in a 6-year-old girl by array-based comparative genomic hybridization (a-CGH) and assess prognosis, and to search for constitutional copy number variations (CNVs) encompassing oncosuppressor genes.

Methods

High-resolution a-CGH was performed on genomic DNA from cancer cells and from peripheral blood cells. Histopathology and clinical staging of the tumor were simultaneously assessed.

Results

Array-based CGH revealed no CNVs on tumor cells associated with poor prognosis; namely, no monosomy 3, losses of 1p, 6q, or 8p, and no gains of 8q. A unique genomic profile was observed, consisting mainly of partial terminal duplications affecting chromosomes 1, 4, 5, 9, 10, 11, 16, and 19, and complete trisomy of chromosomes 6, 7, and 20. The nonmetastatic tumor had predominantly epithelioid histology. No constitutional CNVs encompassing oncosuppressor genes were detected.

Conclusions

We report a very rare uveal melanoma characterized by low-risk genomic profile and poor prognostic histologic and clinical features. The child is relapse-free at 1-year follow-up. The unusual CNVs detected by a-CGH suggest specific pathogenic mechanisms.
Influence of the Two-Layer Preservation Method on Human Pancreatic Islet Isolation: A Meta-Analysis
Authors: Li Xiaohang , Zhang Jialin , Sang Lixuan , Chu Zhiqiang , Dong Ming
Published: March 2015

Introduction

There has been continuous debate on whether the Two-Layer Method (TLM) is superior to the University of Wisconsin solution (UW) for preserving human pancreas prior to islet isolation. The objective of the current meta-analysis is to assess which method is superior.

Methods

We searched electronic databases (MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials) for relevant human trials published in the English language from January 2000 to October 2013. Data on donor characteristics and islet isolation outcomes were extracted.

Results

14 articles containing 18 human studies were included in this meta-analysis. In comparison to UW alone, TLM alone produced a significantly higher islet yield (weighted mean difference, 776.32; 95% confidence interval; 370.82-1181.82; P = .0002). TLM alone also yielded higher proportion of transplantable preparations (odds ratio, 1.60; 95% confidence interval; 1.15-2.23; P = .005). The following measures did not differ: islet viability (weighted mean difference, 2.10; −2.41-6.60; P = .360), purity (weighted mean difference, −0.92; −3.75-1.91; P = .520) and function assessed by measuring the stimulation index (weighted mean difference, 0.17; −0.21-0.55; P = .380). When comparing TLM following UW storage with UW alone, the results were similar to the previous ones.

Conclusions

This data indicates that the TLM can improve islet yield and increase the opportunities of human pancreatic islet transplantation. Therefore, the TLM should be recommended for preserving human pancreas prior to islet isolation.
Identification of Biomarkers for the Prognosis of Pancreatic Ductal Adenocarcinoma with miRNA Microarray Data
Authors: Wang Song , Zhao Yanxun , Li Dongsheng , Zhu Liangchen , Shen Zugang
Published: March 2015

Background

The aim of this study was to explore the mechanism of chemotherapy resistance and to screen biomarkers of pancreatic ductal adenocarcinoma (PDAC).

Methods

MicroRNA (miRNA) expression profile data for GSE38781 were downloaded from the Gene Expression Omnibus database. Differentially expressed miRNAs between short–overall survival (OS) and long-OS patients were screened with the limma package in R. The function and protein–protein interaction (PPI) network of the miRNA target genes were further investigated. Finally, multivariate statistical analysis was performed to verify the significant miRNAs obtained in our work.

Results

In total, 66 miRNAs were identified to be differentially expressed. Gene ontology (GO) and pathway enrichment analysis showed that 163 miRNA target genes were mainly enriched in heart function, cancer development and angiogenesis. Ten nodes, including TGFBR1, TGFBR2, ACVR1 and SHC1, were found to be hub nodes in the PPI network. Multivariate statistical analysis showed 8 of the most significant miRNAs could completely distinguish the 2 groups of samples. Seven target genes (i.e., RET, ETS1, RHOA, NUMB, TIAM, ITGA5 and YY1) of the 8 significant miRNAs were found to be associated with control of cell fate decisions, T-cell lymphoma invasion and angiogenesis enhancement.

Conclusions

The heart function–related pathway, cell cycle, immune system and angiogenesis may be dysregulated in patients with poorer prognosis. The significant nodes (e.g., TGFBR1, TGFBR2, ACVR1 and SHC1) in the PPI network may be potential biomarkers for predicting outcomes for patients with pancreatic cancer. The significant miRNAs and gene targets may be potential biomarkers or therapeutic targets for PDAC.