bluuebunny/crossref_metadata_2025 huggingface dataset:
SiC Current Limiting FETs (CLFs) for DC Applications
Authors: Tournier Dominique , Godignon Philippe , Niu Shi Qin , de Palma Jean François
Published: February 2014

To address safety issue of DC networks in distribution and generation plants, a specific Current Limiting FET has been design. The fabricated power switch is able to operate in both forward and reverse conduction mode. Short-circuit time to failure has been adjust and a current sensing electrode as been added to ease the monitoring and the drive of this switch. Fabricated devices have been packaged in TO3 metal can, providing good heat conduction and durability. A maximum short circuit energy of 70J/cm2 as been measured for a IN = 6 A VBR = 1800 V rated device, corresponding to a short-circuit time before failure of tCC = 21ms under VDC = 300 V .
A Novel Truncated V-Groove 4H-SiC MOSFET with High Avalanche Breakdown Voltage and Low Specific on-Resistance
Authors: Masuda Takeyoshi , Wada Keiji , Hiyoshi Toru , Saito Yu , Tamaso Hideto , Sakai Mitsuhiko , Hiratsuka Kenji , Mikamura Yasuki , Nishiguchi Masanori , Hatayama Tomoaki , Yano Hiroshi
Published: February 2014

A breakdown of a conventional trench SiC-MOSFET is caused by oxide breakdown at the bottom of the trench. We have fabricated a novel trench SiC-MOSFET with buried p+ regions and demonstrated the high breakdown voltage of 1700 V and the specific on-resistance of 3.5 mΩcm2.
SiC Trench MOSFET with an Integrated Low Von Unipolar Heterojunction Diode
Authors: Ni Wei , Emori Kenta , Marui Toshiharu , Saito Yuji , Yamagami Shigeharu , Hayashi Tetsuya , Hoshi Masakatsu
Published: February 2014

We demonstrate a SiC trench MOSFET with an integrated low Von unipolar heterojunction diode (MOSHJD). A region of the heterojunction diode (HJD) was fabricated in a trench with p+-type poly-crystalline silicon on an n--type epitaxial layer of 4H-SiC. The measured on-resistance (Ron) of the transistor action was 15 mΩcm2. The measured Von of the diode action was 2.2 V at a forward current density of 100 A/cm2. The fabrication process of the MOSHJD is simple. First, the trenches of the MOSFET region and the HJD region are formed simultaneously; then poly-crystalline silicon is deposited to form the gate electrode of the MOSFET region and the anode electrode of the HJD region at the same time.
600 V -Class V-Groove SiC MOSFETs
Authors: Saito Yu , Furumai Masaki , Hiyoshi Toru , Wada Keiji , Masuda Takeyoshi , Hiratsuka Kenji , Mikamura Yasuki , Hatayama Tomoaki
Published: February 2014

The authors applied a thick gate oxide layer at the trench bottoms to 600 V class truncated V-groove MOSFETs of which MOS channels were formed on 4H-SiC (0-33-8) facets and validated the static and switching characteristics. The specific on-resistance and the threshold voltage were 3.6 mΩ cm2 (VGS=18 V, VDS=1 V) and about 1 V (normally-off), respectively. The breakdown voltage of the MOSFET with a thick oxide layer was 1,125 V (IDS=1 μA). The switching losses during turn-on and turn-off operations were estimated to be 105.8 μJ and 82.5 μJ (300 V, 10 A) at room temperature. The switching characteristics exhibited low temperature dependence for turn-on/off time.
1200 V 4H-SiC DMOSFET with an Integrated Gate Buffer
Authors: Ryu Sei Hyung , Jonas Charlotte , Capell Craig , Lemma Yemane , Agarwal Anant , McNutt Ty , Grider Dave , Allen Scott T. , Palmour John W.
Published: February 2014

For the first time, a 1200 V 4H-SiC power MOSFET with a monolithically integrated gate buffer circuit has been demonstrated successfully. The device used a 6x1015 cm-3 doped, 10 μm thick n-type drift layer to support 1200 V. The gate buffer circuit was built in a p-well, formed by boron ion implantation. The integrated device provided sufficient voltage isolation for the control circuit from the drain of the power MOSFET, and supported internal supply voltages up to 20 V. The operation of the integrated devices was demonstrated. A specific on-resistance (Ron,sp) of 20 mΩ-cm2 was observed. The high Ron,sp was due to the limitations in NMOS pull-up circuit topology and the body effect in the 4H-SiC NMOSFET. Development of PMOS pull-up devices is recommended for future integration efforts.
Effects of the Growth Rate on the Quality of 4H Silicon Carbide Films for MOSFET Applications
Authors: Camarda Massimo , Privitera Stefania , Anzalone Ruggero , Piluso Nicolò , Fiorenza Patrick , Alberti Alessandra , Pellegrino Giovanna , La Magna Antonino , La Via Francesco , Vecchio Carmelo , Mauceri Marco , Litrico Grazia , Pecora Antonino , Crippa Danilo
Published: February 2014

In this paper we investigate the role of the growth rate (varied by changing the Si/H2 ratio and using TCS to avoid Si droplet formation) on the surface roughness (Rq), the density of single Shockley stacking faults (SSSF) and 3C-inclusions (i.e. epi-stacking faults, ESF). We find that optimized processes with higher growth rates allow to improve the films in all the considered aspects. This result, together with the reduced cost of growth processes, indicates that high growth rates should always be used to improve the overall quality of 4H-SiC homoepitaxial growths. Furthermore we analyze the connection between surface morphology and density of traps (Dit) at the SiO2/SiC interface in fabricated MOS devices finding consistent indications that higher surface roughness (step-bunched surfaces) can improve the quality of the interface by reducing the Dit value.
Impact of Hot Carrier Degradation and Positive Bias Temperature Stress on Lateral 4H-SiC nMOSFETs
Authors: Pobegen Gregor , Aichinger Thomas , Salinaro Alberto , Grasser Tibor
Published: February 2014

We study the impact of positive bias temperature stress and hot carrier stress on lateral 4H-SiC nMOSFETs. These degradation mechanisms are prominent in silicon based devices where both create oxide as well as interface traps. For SiC MOSFETs only limited information regarding these mechanisms is available. We transfer the charge pumping technique, known from Si MOSFETs, reliably to SiC MOSFETs to learn about the nature of the stress induced defects.
Comparison of 600V Si, SiC and GaN Power Devices
Authors: Chowdhury Sauvik , Stum Zachary , Li Zhong Da , Ueno Katsunori , Chow T. Paul
Published: February 2014

In this paper the DC and switching performance of 600V Si, SiC and GaN power devices using device simulation. The devices compared are Si superjunction MOSFET, Si field stop IGBT, SiC UMOSFET and GaN HEMT.
Electrical Characteristics/Reliability Affected by Defects Analyzed by the Integrated Evaluation Platform for SiC Epitaxial Films
Authors: Kitabatake Makoto , Sako Hideki , Sasaki Masayuki , Yamashita Tamotsu , Tamura Kentaro , Yamada Keiichi , Ishiyama Osamu , Senzaki Junji , Matsuhata Hirohumi
Published: February 2014

The Integrated Evaluation Platform for SiC wafers and epitaxial films is established and provide TDDB reliability data such as Qbd. Accumulated numerous Qbd data derived from the platform shows three discrete universal distributions (D1>D2>D3) mainly affected by step bunching. On the fairly flat surface, locally spreading step-bunching area formation is caused by the scratches on the CMP surface. The step-bunching area contains large number of step-bunching lines, which correspond to trapezoid-shape defects, stretching in a low along the scratches. Only the downstream bases of the trapezoid-shape defects degrade the Qbd into D2 from D1 on the flat surface without step bunching.
Novel Gate Oxide Process for Realization of High Threshold Voltage in 4H-SiC MOSFET
Authors: Furuhashi Masayuki , Tanioka Toshikazu , Imaizumi Masayuki , Miura Naruhisa , Yamakawa Satoshi
Published: February 2014

We found that threshold voltage (Vth) of a 4H-SiC MOSFET increases drastically by performing low temperature wet oxidation after nitridation in a gate oxide process. The increment of Vth depends on the wet oxidation conditions. Wet oxidation increases the interface trap density (Dit) at deep level of SiC bandgap and decreases positive charge density inside the gate oxide layer. The amount change of the interface traps and the positive charges in the gate oxide makes Vth higher without a decrease in the channel mobility. We improved the trade-off between Vth and effective carrier mobility (μeff) in the MOSFET channel, and realized a low specific on-resistance (Ron,sp) SiC-MOSFET with Vth over 5 V by using the newly developed process.
Comparative Study of 4H-SiC DMOSFETs with N2O Thermal Oxide and Deposit Oxide with Post Oxidation Anneal
Authors: Yen Cheng Tyng , Hung Chien Chung , Mikhaylov Aleksey , Lee Chwan Ying , Lee Lurng Shehng , Wei Jeng Hua , Chiu Ting Yu , Huang Chih Fang , Reshanov Sergey A. , Schöner Adolf
Published: February 2014

Two kinds of gate oxides, direct thermal oxidation in a nitrous oxide ambient at 1250°C(TGO) and a PECVD oxide followed by a post deposition oxidation in nitrous at 1150°C (DGO) were studied. DGO showed a lower interface trap density and was able to provide a higher current as being implemented in MOSFETs through the improved channel mobility. However the 6.45 MV/cm average breakdown field of DGO is lower than the 10.1 MV/cm breakdown field of TGO. The lower breakdown field, more leaky behavior and the existence of multiple breakdown mechanisms suggest that DGO needs further improvements before it can be used in real applications.
Conversion of Basal Plane Dislocations to Threading Edge Dislocations in Growth of Epitaxial Layers on 4H-SiC Substrates with a Vicinal Off-Angle
Authors: Masumoto Keiko , Ito Sachiko , Goto Hideto , Yamaguchi Hirotaka , Tamura Kentaro , Kudou Chiaki , Nishio Johji , Kojima Kazutoshi , Ohno Toshiyuki , Okumura Hajime
Published: February 2014

We have investigated a conversion of basal plane dislocation (BPD) to threading edge dislocation (TED) in growth of epitaxial layers (epi-layers) on 4H-SiC vicinal substrates with an off-angle of 0.85° at low C/Si ratio of 0.7 by using deep KOH etching and X-ray topography observations. Deep KOH etching indicated that BPDs in the substrates converted to TEDs in the epi-layers. X-ray topography observations suggested that the conversion occurred during epitaxial growth when the thickness of epi-layers was less than 1.5 μm. We found that the conversion ratio obtained from counting deep KOH etch pits was over 99%.
Engine Control Unit Testing by Hardware-in-the-Loop Simulation
Authors: Mamala Jarosław , Brol Sebastian , Graba Mariusz
Published: February 2014

The article presents simulator of injection-ignition system of internal combustion engine with spark ignition developed at the Technical University of Opole. This system is based on Bosch series engine ECU with software 7.5. It allows to analyze of motor parameters using both on-board diagnostic system, and data network CAN BUS under different operating conditions of the system. For this purpose, the simulator is equipped with a number of additional devices enable to generate repetitive input signals for the ECU, allowing to open the actual working conditions. Crucial for the simulator was to generate the signals informing ECU about the instantaneous position of the crankshaft and camshaft. For this purpose, the module Arduino was used. This type of solution allows, to recreate momentary engine operating conditions. This article also presents the concept of development with new features and sentences feasible for this type of device and simulation mode.
Technique for Analysis of the Spatial Field Distribution in Tapered Wire Medium
Authors: Kozhara Liubov I. , Polevoy Sergey Y. , Popov I.V.
Published: February 2014

The paper is devoted to experimental investigation of the spatial distribution of electromagnetic field in the vicinity of the tapered wire medium formed by copper wires conductors in the millimeter waveband. The experimental technique, based on the small perturbations method and used the special software has been elaborated for electromagnetic field distribution registering. The optimal type of probe has been determined. The electromagnetic energy concentration in the vicinity of the narrow planes of the tapered wire medium has been demonstrated experimentally. It is shown that the width of the wave beam behind the narrow facet of the lens insignificantly increases with distance. The field patterns with resolution ± 0.01dB in the vicinity of wide planes of lens have been registered.
Protective CD4 T Cells Targeting Cryptic Epitopes of Mycobacterium tuberculosis Resist Infection-Driven Terminal Differentiation
Authors: Woodworth Joshua S. , Aagaard Claus Sindbjerg , Hansen Paul R. , Cassidy Joseph P. , Agger Else Marie , Andersen Peter
Published: February 2014

CD4 T cells are crucial to the control of Mycobacterium tuberculosis infection and are a key component of current vaccine strategies. Conversely, immune-mediated pathology drives disease, and recent evidence suggests that adaptive and innate responses are evolutionarily beneficial to M. tuberculosis. We compare the functionality of CD4 T cell responses mounted against dominant and cryptic epitopes of the M. tuberculosis 6-kDa early secreted Ag (ESAT-6) before and postinfection. Protective T cells against cryptic epitopes not targeted during natural infection were induced by vaccinating mice with a truncated ESAT-6 protein, lacking the dominant epitope. The ability to generate T cells that recognize multiple cryptic epitopes was MHC-haplotype dependent, including increased potential via heterologous MHC class II dimers. Before infection, cryptic epitope–specific T cells displayed enhanced proliferative capacity and delayed cytokine kinetics. After aerosol M. tuberculosis challenge, vaccine-elicited CD4 T cells expanded and recruited to the lung. In chronic infection, dominant epitope–specific T cells developed a terminal differentiated KLRG1+/PD-1lo surface phenotype that was significantly reduced in the cryptic epitope–specific T cell populations. Dominant epitope-specific T cells in vaccinated animals developed into IFN-γ– and IFN-γ,TNF-α–coproducing effector cells, characteristic of the endogenous response. In contrast, cryptic epitope–specific CD4 T cells maintained significantly greater IFN-γ+TNF-α+IL-2+ and TNF-α+IL-2+ memory-associated polyfunctionality and enhanced proliferative capacity. Vaccine-associated IL-17A production by cryptic CD4 T cells was also enhanced, but without increased neutrophilia/pathology. Direct comparison of dominant/cryptic epitope–specific CD4 T cells within covaccinated mice confirmed the superior ability of protective cryptic epitope–specific T cells to resist M. tuberculosis infection–driven T cell differentiation.
Identification of Two Forms of TNF Tolerance in Human Monocytes: Differential Inhibition of NF-κB/AP-1– and PP1-Associated Signaling
Authors: Günther Johannes , Vogt Nico , Hampel Katharina , Bikker Rolf , Page Sharon , Müller Benjamin , Kandemir Judith , Kracht Michael , Dittrich-Breiholz Oliver , Huber René , Brand Korbinian
Published: February 2014

The molecular basis of TNF tolerance is poorly understood. In human monocytes we detected two forms of TNF refractoriness, as follows: absolute tolerance was selective, dose dependently affecting a small group of powerful effector molecules; induction tolerance represented a more general phenomenon. Preincubation with a high TNF dose induces both absolute and induction tolerance, whereas low-dose preincubation predominantly mediates absolute tolerance. In cells preincubated with the high TNF dose, we observed blockade of IκBα phosphorylation/proteolysis and nuclear p65 translocation. More prominent in cells preincubated with the high dose, reduced basal IκBα levels were found, accompanied by increased IκBα degradation, suggesting an increased IκBα turnover. In addition, a nuclear elevation of p50 was detected in tolerant cells, which was more visible following high-dose preincubation. TNF-induced phosphorylation of p65-Ser536, p38, and c-jun was inhibited, and basal inhibitory p65-Ser468 phosphorylation was increased in tolerant cells. TNF tolerance induced by the low preincubation dose is mediated by glycogen synthesis kinase-3, whereas high-dose preincubation-mediated tolerance is regulated by A20/glycogen synthesis kinase-3 and protein phosphatase 1–dependent mechanisms. To our knowledge, we present the first genome-wide analysis of TNF tolerance in monocytic cells, which differentially inhibits NF-κB/AP-1–associated signaling and shifts the kinase/phosphatase balance. These forms of refractoriness may provide a cellular paradigm for resolution of inflammation and may be involved in immune paralysis.
Ovine pulmonary adenocarcinoma in slaughtered sheep: A pathological and polymerase chain reaction study
Authors: Azizi Shahrzad , Tajbakhsh Elahe , Fathi Farzad
Published: February 2014

Ovine pulmonary adenocarcinoma (OPA) is a contagious tumour in sheep caused by jaagsiekte sheep retrovirus (JSRV). This tumour originates from the pneumocyte type II and Clara cells and grossly appears as hard, prominent nodules in different lobes. The clinical signs of the disease are similar to those of other chronic respiratory diseases and are not pathogonomic. Therefore, post mortem examinations and histopathological studies are the most reliable ways to diagnose OPA, particularly subclinical cases of this neoplasm. In this study, out of 1000 sheep lungs grossly inspected, 50 animals were suspected of OPA. The suspected lungs as well as 25 apparently normal lungs were examined by histopathological and PCR methods. The proviral DNA was detected in 1/25 apparently normal lungs and 8/50 of the suspected lungs and subsequently confirmed by histopathological studies. The PCR-positive lung samples from five sheep revealed lesions of ’atypical’ OPA and those from three sheep showed the ’classic’ form of the disease. The tumours were multifocal and the masses were distributed throughout the cranioventral and diaphragmatic lung lobes. The stroma of the tumours in the atypical cases was more severely affected with inflammatory cell infiltration and connective tissue proliferation. The histopathological characteristics of maedi including hyperplasia of the perivascular and peribronchiolar lymphoid cells, interstitial lymphoplasmacytic infiltration and smooth muscle hyperplasia were also associated with OPA, especially the atypical form of this adenocarcinoma. Atypical OPA was more prevalent than the classic form. Geographic and climatic conditions, duration of exposure to the virus and the immune status of individual animals might be responsible for the differences between the two pathological entities of OPA.
Prairie Thunder flax
Authors: Duguid S. D. , Rashid K. Y. , Kenaschuk E. O.
Published: February 2014

Duguid, S. D., Rashid, K. Y. and Kenaschuk, E. O. 2014. Prairie Thunder flax. Can. J. Plant Sci. 94: 445–449. Prairie Thunder, medium-maturing oilseed flax (Linum usitatissimum L.), was released in 2006 by Agriculture and Agri-Food Canada, Morden Research Station, Morden, Manitoba. Developed from the cross AC Watson/FP1043 made in 1995, Prairie Thunder was evaluated in the Flax Cooperative Trials (2002–2004) before being registered in 2006. Prairie Thunder's desirable combination of improved agronomic traits, seed quality and superior wilt (Fusarium oxysporum Schlecht. f. sp. lini (Bolley) Snyder & Hansen) resistance should make this cultivar useful for producers and the flax industry.
CTH8 flue-cured tobacco hybrid
Authors: Amankwa G. A. , Mishra S. , Shearer A. D. , Brammall R. , Van Hooren D. L.
Published: February 2014

Amankwa, G. A., Mishra, S., Shearer, A. D., Brammall, R. and Van Hooren, D. L. 2014. CTH8 flue-cured tobacco hybrid. Can. J. Plant Sci. 94: 461–463. CTH8 is a new flue-cured tobacco (Nicotiana tabacum L.) hybrid recommended for commercial release in Canada. It has superior grade index compared to the check varieties Delgold and CT157, and its yield potential is intermediate between the two checks.
TransCom N2O model inter-comparison, Part II: Atmospheric inversion estimates of N2O emissions
Authors: Thompson R. L. , Ishijima K. , Saikawa E. , Corazza M. , Karstens U. , Patra P. K. , Bergamaschi P. , Chevallier F. , Dlugokencky E. , Prinn R. G. , Weiss R. F. , O'Doherty S. , Fraser P. J. , Steele L. P. , Krummel P. B. , Vermeulen A. , Tohjima Y. , Jordan A. , Haszpra L. , Steinbacher M. , Van der Laan S. , Aalto T. , Meinhardt F. , Popa M. E. , Moncrieff J. , Bousquet P.
Published: February 2014

Abstract. This study examines N2O emission estimates from 5 different atmospheric inversion frameworks. The 5 frameworks differ in the choice of atmospheric transport model, meteorological data, prior uncertainties and inversion method but use the same prior emissions and observation dataset. The mean emissions for 2006 to 2008 are compared in terms of the spatial distribution and seasonality. Overall, there is a good agreement among the inversions for the mean global total emission, which ranges from 16.1 to 18.7 Tg N yr−1 and is consistent with previous estimates. Ocean emissions represent between 31% and 38% of the global total compared to widely varying previous estimates of 24% to 38%. Emissions from the northern mid to high latitudes are likely to be more important, with a consistent shift in emissions from the tropics and subtropics to the mid to high latitudes in the Northern Hemisphere; the emission ratio for 0–30° N to 30–90° N ranges from 1.5 to 1.9 compared with 2.9 to 3.0 in previous estimates. The largest discrepancies across inversions are seen for the regions of South and East Asia and for tropical and South America owing to the poor observational constraint for these areas and to considerable differences in the modelled transport, especially inter-hemispheric exchange rates and tropical convection. Estimates of the seasonal cycle in N2O emissions are also sensitive to errors in modelled stratosphere-to-troposphere transport in the tropics and southern extra-tropics. Overall, the results show a convergence in the global and regional emissions compared to previous independent studies.
Can the heterogeneity in stream dissolved organic carbon be explained by contributing landscape elements?
Authors: Ågren A. M. , Buffam I. , Cooper D. M. , Tiwari T. , Evans C. D. , Laudon H.
Published: February 2014

Abstract. The controls on stream dissolved organic carbon (DOC) concentrations were investigated in a 68 km2 catchment by applying a landscape-mixing model to test if downstream concentrations could be predicted from contributing landscape elements. The landscape-mixing model reproduced the DOC concentration well throughout the stream network during times of high and intermediate discharge. The landscape-mixing model approach is conceptually simple and easy to apply, requiring relatively few field measurements and minimal parameterisation. Our interpretation is that the higher degree of hydrological connectivity during high flows, combined with shorter stream residence times, increased the predictive power of this whole watershed-based mixing model. The model was also useful for providing a baseline for residual analysis, which highlighted areas for further conceptual model development. The residual analysis indicated areas of the stream network that were not well represented by simple mixing of headwaters, as well as flow conditions during which simple mixing based on headwater watershed characteristics did not apply. Specifically, we found that during periods of baseflow the larger valley streams had much lower DOC concentrations than would be predicted by simple mixing. Longer stream residence times during baseflow and changing hydrological flow paths were suggested as potential reasons for this pattern. This study highlights how a simple landscape-mixing model can be used for predictions as well as providing a baseline for residual analysis, which suggest potential mechanisms to be further explored using more focused field and process-based modelling studies.
Technical Note: Approximate Bayesian parameterization of a process-based tropical forest model
Authors: Hartig F. , Dislich C. , Wiegand T. , Huth A.
Published: February 2014

Abstract. Inverse parameter estimation of process-based models is a long-standing problem in many scientific disciplines. A key question for inverse parameter estimation is how to define the metric that quantifies how well model predictions fit to the data. This metric can be expressed by general cost or objective functions, but statistical inversion methods require a particular metric, the probability of observing the data given the model parameters, known as the likelihood. For technical and computational reasons, likelihoods for process-based stochastic models are usually based on general assumptions about variability in the observed data, and not on the stochasticity generated by the model. Only in recent years have new methods become available that allow the generation of likelihoods directly from stochastic simulations. Previous applications of these approximate Bayesian methods have concentrated on relatively simple models. Here, we report on the application of a simulation-based likelihood approximation for FORMIND, a parameter-rich individual-based model of tropical forest dynamics. We show that approximate Bayesian inference, based on a parametric likelihood approximation placed in a conventional Markov chain Monte Carlo (MCMC) sampler, performs well in retrieving known parameter values from virtual inventory data generated by the forest model. We analyze the results of the parameter estimation, examine its sensitivity to the choice and aggregation of model outputs and observed data (summary statistics), and demonstrate the application of this method by fitting the FORMIND model to field data from an Ecuadorian tropical forest. Finally, we discuss how this approach differs from approximate Bayesian computation (ABC), another method commonly used to generate simulation-based likelihood approximations. Our results demonstrate that simulation-based inference, which offers considerable conceptual advantages over more traditional methods for inverse parameter estimation, can be successfully applied to process-based models of high complexity. The methodology is particularly suitable for heterogeneous and complex data structures and can easily be adjusted to other model types, including most stochastic population and individual-based models. Our study therefore provides a blueprint for a fairly general approach to parameter estimation of stochastic process-based models.
Icehouse–greenhouse variations in marine denitrification
Authors: Algeo T. J. , Meyers P. A. , Robinson R. S. , Rowe H. , Jiang G. Q.
Published: February 2014

Abstract. Long-term secular variation in the isotopic composition of seawater fixed nitrogen (N) is poorly known. Here, we document variation in the N-isotopic composition of marine sediments (δ15Nsed) since 660 Ma (million years ago) in order to understand major changes in the marine N cycle through time and their relationship to first-order climate variation. During the Phanerozoic, greenhouse climate modes were characterized by low δ15Nsed (∼−2 to +2‰) and icehouse climate modes by high δ15Nsed (∼+4 to +8‰). Shifts toward higher δ15Nsed occurred rapidly during the early stages of icehouse modes, prior to the development of major continental glaciation, suggesting a potentially important role for the marine N cycle in long-term climate change. Reservoir box modeling of the marine N cycle demonstrates that secular variation in δ15Nsed was likely due to changes in the dominant locus of denitrification, with a shift in favor of sedimentary denitrification during greenhouse modes owing to higher eustatic (global sea-level) elevations and greater on-shelf burial of organic matter, and a shift in favor of water-column denitrification during icehouse modes owing to lower eustatic elevations, enhanced organic carbon sinking fluxes, and expanded oceanic oxygen-minimum zones. The results of this study provide new insights into operation of the marine N cycle, its relationship to the global carbon cycle, and its potential role in modulating climate change at multimillion-year timescales.
Response of CH4 emission to moss removal and N addition in boreal peatland of Northeast China
Authors: Meng H. N. , Song C. C. , Miao Y. Q. , Mao R. , Wang X. W.
Published: February 2014

Abstract. Boreal peatlands are an important natural source of atmospheric methane (CH4). Recently, boreal peatlands have been experiencing increased nitrogen (N) input and decreased moss production. However, little is known about the interactive effect of moss and N availability on CH4 emission in boreal peatlands. In this study, the effects of moss removal and N addition (6 g N m−2 yr−1) on CH4 emission were examined during the growing seasons of 2011 to 2013 in a boreal peatland in the Great Hinggan Mountain of Northeast China. Notably, the response of CH4 emission to moss removal and N addition varied with experimental duration. Moss removal and N addition did not affect CH4 emission in 2011 and 2012, but respectively declined CH4 emission by 50% and 66% in 2013. However, moss removal and N addition did not produce an interactive effect on CH4 emission. Specifically, moss removal plus N addition had no effect on CH4 emission in 2011 and 2012, but decreased CH4 emission by 68% in 2013. These results suggest that the effects of moss removal and N enrichment on CH4 emission are time-dependent in boreal peatlands, and also imply that increased N loading and decreased moss growth would independently inhibit CH4 emission in the boreal peatlands of Northeast China.
Estimating annual groundwater recharge coefficient for karst aquifers of the southern Apennines (Italy)
Authors: Allocca V. , Manna F. , De Vita P.
Published: February 2014

Abstract. To assess the mean annual groundwater recharge of the karst aquifers in the southern Apennines (Italy), the estimation of the mean annual groundwater recharge coefficient (AGRC) was conducted by means of an integrated approach based on hydrogeological, hydrological, geomorphological, land use and soil cover analyses. Starting from the hydrological budget equation, the coefficient was conceived as the ratio between the net groundwater outflow and the precipitation minus actual evapotranspiration (P − ETR) for a karst aquifer. A large part of the southern Apennines, which is covered by a meteorological network containing 40 principal karst aquifers, was studied. Using precipitation and air temperature time series gathered through monitoring stations operating in the period 1926–2012, the mean annual P − ETR was estimated, and its distribution was modelled at a regional scale by considering the orographic barrier and rain shadow effects of the Apennine chain, as well as the altitudinal control. Four sample karst aquifers with available long spring discharge time series were identified for estimating the AGRC. The resulting values were correlated with other parameters that control groundwater recharge, such as the extension of outcropping karst rocks, morphological settings, land use and covering soil type. A multiple linear regression between the AGRC, lithology and the summit plateau and endorheic areas was found. This empirical model was used to assess the AGRC and mean annual groundwater recharge in other regional karst aquifers. The coefficient was calculated as ranging between 50 and 79%, thus being comparable with other similar estimations carried out for karst aquifers of European and Mediterranean countries. The mean annual groundwater recharge for karst aquifers of the southern Apennines was assessed by these characterizations and validated by a comparison with available groundwater outflow measurements. These results represent a deeper understanding of an aspect of groundwater hydrology in karst aquifers which is fundamental for the formulation of appropriate management models of groundwater resources at a regional scale, also taking into account mitigation strategies for climate change impacts. Finally, the proposed hydrological characterizations are also supposed to be useful for the assessment of mean annual runoff over carbonate mountains, which is another important topic concerning water management in the southern Apennines.
Xenophobia and Racism
Authors: Sundstrom Ronald R. , Kim David Haekwon
Published: February 2014

Xenophobia is conceptually distinct from racism. Xenophobia is also distinct from nativism. Furthermore, theories of racism are largely ensconced in nationalized narratives of racism, which are often influenced by the black-white binary, which obscures xenophobia and shelters it from normative critiques; so, philosophical accounts of racism, rather than merely subsuming racism, end up neglecting this historically important category of exclusion and oppression. This paper addresses these claims, arguing for the first and last, and outlining the second. Just as philosophers have recently analyzed the concept of racism, clarifying it and pinpointing why it's immoral and the extent of its moral harm, so we will analyze xenophobia and offer a pluralist account of xenophobia, with important implications for racism. This analysis is guided by the discussion of racism in recent moral philosophy, social ontology, and research in the psychology of racism and implicit attitudes.
Xenoracism and Double Whiteness
Authors: Lee Kyoo
Published: February 2014

What unites Arizona's current xenophobic, border cultural politics and the exemplary life of Benjamin Franklin, “True-blue English/First American”? What transhistorical resonances and parallels are there in those states of affairs? Casting a double look at “the inside looking out” and “the outside looking in,” Anglo Americana vis-à-vis (Post-)Pax Britannica and vice versa, this piece (re)turns to the postcolonial identity disorder endured then by our dear Ben, a ghostly transitory figure here, as a way to initiate a critical philosophical discourse on transatlantic Anglocentrism and its psycho-geopolitical legacy of xeno-thinking in the cultural and historical imaginary of the United States, where a psycho-geopolitical reaction-formation of WAS (White Anglo-Saxon) self-identities has been the operative norm, a particular form and force of ethnonationalizing racial discourse in the United States, namely, “xenoracism”: the amalgamated categorical interactions of xenophobia and racism, a porous sub(terranean)genre rather than sealed subset of xenophobia or racism, where the foreign is racialized and particular “aliens” become further alienized at once with catalytic, categorical reciprocity. Presented as a preamble to a fuller conceptualization of U.S. xenoracism, this exposition spotlights the post/colonial complexity, including irony, of that “special” gray/grey tie between the two bound and “divided” by shared Anglophonocentrism, “Comyn Englysshe,” this wounded attachment.
Lymphangioleiomyomatosis: An unusual age of diagnosis with literature review
Authors: Youssef Alaoui Lamrani , Alami Badr , Sahnoun Ferdaous , Boubbou Meriem , Kamaoui Imane , Maâroufi Mustapha , Houssaini Nadia Sqalli , Amara Bouchra , Tizniti Siham
Published: February 2014

Lymphangioleiomyomatosis (LAM) is a rare idiopathic disorder of unclear origin, which almost exclusively occurs to women before menopause. It is characterized by nonneoplastic diffuse proliferation of atypical immature smooth muscle cells around small airways and vessels. We report the case of a 64-year-old woman kept for chronic progressive dyspnea related to a diffuse LAM.The discussion includes a literature review that describes the physiopathology, clinical features, chest computed tomography aspects, and differential diagnosis regarding this rare disease.Through this case report, pulmonary LAM should be included in the list of differential diagnoses for cases of pulmonary cystic lesions, even in postmenopausal women.
Through the Lens of Loss: Marina Tsvetaeva's Elegiac Photo-Poetics
Authors: Blasing Molly Thomasy
Published: February 2014

Marina Tsvetaeva is often described as a poet of keen aural sensibilities, while the visual world has been thought to be of secondary importance to her. This study of the influence of photography on Tsvetaeva's poetic writing contributes new evidence of the role of visual culture in her creative world. In detailing Tsvetaeva's experiences with the material and metaphysical properties of photographic imagery, Molly Thomasy Blasing argues that photography played a significant role in shaping the poet's elegiac writings on death, loss, and separation. The article makes available a number of previously unpublished archival photographs taken by Tsvetaeva—images that are directly linked to her cycle of poems dedicated to Nikolai Gronskii, Nadgrobie. Blasing contextualizes this discovery within a network of other photo-poetic encounters in Tsvetaeva's life and works, revealing the extent to which the poet's thinking about photography relates to the goals of her poetic practice.
Selling Market Socialism: Hungary in the 1960s
Authors: Greene Beth
Published: February 2014

Beth Greene discusses the media portrayal of sales and marketing activities in the early phase of the Hungarian market reforms in the late 1960s. Using articles from the popular and specialist press and archive sources from Hungarian Radio and Television, the author argues that under the New Economic Mechanism (NEM), sellers were elevated as symbolic figures of market socialism and thus the modern socialist economy. The media portrayed sales activities as addressing endemic problems of the command economy, mediating production and consumption, and creating a buyer's market in which sellers would compete for customers. This article provides a unique approach in examining the role of sellers and selling under the market socialism, adding to the rich literature on state socialist consumption and challenging the traditional view that Soviet bloc governments sought to control production and consumption independently and irrespective of their connection to the market.
Five Important Advances in Hematopathology
Authors: Shi Min , Xiao Ruobing , Woda Bruce A. , Yu Hongbo
Published: February 2014

Context.—Hematopathology is a dynamic field that has always been on the frontier of clinical research within the scope of pathology. Several recent developments in hematopathology will likely affect its practice clinically.

Objective.—To review 5 important recent advances in hematopathology: (1) detection and prognostic implication of MYC in diffuse large B-cell lymphomas, (2) determining origin and prognosis through immunoglobulin gene usage in mature B-cell neoplasms, (3)detecting minimal residual disease in multiple myeloma, (4) using genome-wide analysis in myelodysplastic syndromes, and (5) employing whole-genome sequencing in acute myeloid leukemias.

Data Sources.—Literature review and the authors' experiences in an academic center.

Conclusions.—These advances will bring hematopathology into a new molecular era and help us to better understand the molecular, pathologic mechanisms of lymphomas, leukemias, myelomas, and myelodysplastic syndromes. They will help us to identify diagnostic and prognostic markers and eventually provide new therapeutic targets and treatments for these diseases.
MYB Gene Abnormalities t(6;9) in Adenoid Cystic Carcinoma Fine-Needle Aspiration Biopsy Using Fluorescence In Situ Hybridization
Authors: Hudson Jena B. , Collins Brian T.
Published: February 2014

Context.—Fine-needle aspiration (FNA) biopsy of salivary gland neoplasms can have a variety of overlapping appearances. Basaloid neoplasms can be a diagnostic challenge, and FNA cytomorphology alone cannot always provide a definitive diagnosis.

Objective.—To examine the incidence and potential utility of detecting a MYB translocation by fluorescence in situ hybridization (FISH) in adenoid cystic carcinomas (AdCCs) and pleomorphic adenoma FNA smears with known surgical outcomes.

Design.—Patients who underwent FNA biopsy for surgically confirmed AdCCs and pleomorphic adenomas were identified. Fluorescence in situ hybridization, using commercially available fluorescent-labeled probes, hybridizing to MYB-telomeric and MYB-centromeric, was used to identify the MYB gene and to evaluate it for abnormalities and translocation. Using a fluorescent microscope, 4′,6-diamidino-2-phenylindole (DAPI)-stained, nonoverlapping cells were counted, and 10% or greater abnormal cells were considered positive.

Results.—The 10 AdCC and 13 pleomorphic adenoma FNA cases had FISH evaluations performed; 50% (5 of 10) of the AdCC cases showed a MYB abnormality by FISH; 40% (4 of 10) AdCCs showed a positive break-apart signal in most cells (48%–84%). One case (10%) of AdCC showed a trisomy MYB signal pattern without the break-apart translocation pattern. Of the 13 pleomorphic adenomas, none (0%) of the cases showed a MYB translocation or abnormality by FISH. MYB FISH abnormalities showed a 100% positive predictive value, 50% sensitivity, and 100% specificity, when differentiating AdCC from pleomorphic adenoma.

Conclusions.— MYB gene abnormalities were present in 50% (5 of 10) of the AdCC cases. This corresponds to the reported prevalence in formalin-fixed, paraffin-embedded tissue for AdCC surgical resections. Using FISH testing for detecting MYB gene abnormalities in the salivary gland of FNA biopsies has the potential to provide additional, helpful ancillary information in diagnosing AdCC.
Breaking Conventions to Support Quantitative Reasoning
Authors: Moore Kevin C. , Silverman Jason , Paoletti Teo , LaForest Kevin
Published: February 2014

Quantitative reasoning is critical to developing understandings of function that are important for sustained success in mathematics. Unfortunately, preservice teachers often do not receive sufficient quantitative reasoning experiences during their schooling. In this paper, we illustrate consequences of underdeveloped quantitative reasoning abilities against the backdrop of central function concepts. We also illustrate tasks that can perturb preservice teachers' thinking in ways that produce opportunities for quantitative reasoning. By implementing strategically designed tasks, teacher educators can support preservice teachers–and students in general–in advancing their quantitative reasoning abilities and their understanding of secondary mathematics content.
Dangereusement drones : l’« Af-Pak » comme architecture d’un régime gouvernemental optique biopolitique
Authors: Grondin David , Munger1 Sylvain
Published: February 2014

Ce texte s’efforce de montrer que la stratégie de contre-terrorisme poursuivie par l’administration Obama a amplifié et normalisé la pratique contestée de mener des frappes militaires ciblées qu’avait adoptée l’administration précédente à l’aide de drones de combat pour éradiquer des sujets associés au réseau terroriste Al-Qaïda. En évoquant le continuum du régime précédent quant à la doctrine de « frappe préemptive » de l’administration Bush, nous avançons que la guerre des drones est bien en selle avec Barack Obama à ses commandes pour lutter contre le terrorisme. Dans un premier temps, nous retraçons les racines de l’utilisation des drones dans la stratégie militaire américaine, en illustrant comment les assassinats ciblés accompagnant l’avènement des drones s’insèrent dans la transformation du régime gouvernemental de sécurité nationale américain entamé dans le sillage de l’après-11 septembre et axé sur la frappe préemptive. Nous soutenons que l’instauration de ce régime basé sur la vision du chasseur technologique qu’est le drone nous permettra de mettre en relief comment, à travers une domination verticale, s’établit un régime optique capable de discipliner à distance les populations fonctionnant de concert avec la nouvelle stratégie de contre-insurrection. Dans un deuxième temps, nous passons en revue l’application de cette nouvelle tactique secrète de contre-terrorisme dans la zone géopolitique connue comme l’« Af-Pak » pour combattre les forces terroristes (insurgés talibans ou cadres d’Al-Qaïda). C’est devant le constat que l’utilisation des drones chasseurs/tueurs s’est généralisée en Af-Pak que nous interrogeons la dimension nécropolitique de cette stratégie militaire d’assassinats ciblés qui mise sur un régime gouvernemental optique biopolitique.
Du « Consensus de Washington » au « Consensus de Séoul » : quelle place pour l’État dans la gouvernance ?
Authors: Vercauteren Pierre
Published: February 2014

La conception initiale de la gouvernance telle que précisée par la Banque mondiale en 1992 et inspirée dans une perspective normative par le Consensus de Washington était porteuse d’une perspective de mise en retrait de l’État dans un processus auquel des acteurs de différentes natures étaient conviés afin d’apporter des réponses au déficit de légitimité et d’efficacité rencontré par plusieurs pays. Plus récemment, en 2010, l’adoption par les membres du G20 du Consensus de Séoul marque une nouvelle étape dans la conception de la gouvernance, s’éloignant ainsi de l’approche du Consensus de Washington. L’objet de cette contribution consiste à analyser les raisons du passage d’un consensus à l’autre et de préciser plus particulièrement ce que cette évolution implique pour la place de l’État dans la gouvernance. À cette fin, la présente analyse s’intéresse aux limites de la gouvernance appliquée selon sa conception initiale et relève certaines modifications du système international, notamment la survenance des puissances émergentes, dans un contexte de crises multiples, pour en retirer les conséquences sur les États. L’ensemble de ces éléments amène à reconsidérer la place de l’État dans la gouvernance globale, plus particulièrement à l’aune du Consensus de Séoul.
Observation of deep levels and their hole capture behavior in p-type 4H-SiC epilayers with and without electron irradiation
Authors: Kato Masashi , Yoshihara Kazuki , Ichimura Masaya , Hatayama Tomoaki , Ohshima Takeshi
Published: February 2014

To design SiC bipolar devices, information on deep levels acting as recombination centers is essential. In this paper, we report on the observation of deep levels in p-type 4H-SiC epilayers with and without electron irradiation before and after annealing at 1000 °C. We performed current deep level transient spectroscopy (I-DLTS) for the samples, and the observed deep levels were located near the valence band (with the activation energies less than 0.35 eV) in all the samples. Based on the change of I-DLTS spectra by the electron irradiation or the annealing, we discussed the origins of the deep levels. Then we estimated the time constants of hole capture by the deep levels and discussed the possibility that the observed deep levels behave as recombination centers.
Anterior Cruciate Ligament Injuries in Female Athletes
Authors: Napolitano Jonathan , Duerson Drew , MacDonald James
Published: July 2024

This JAMA Insights discusses anterior cruciate ligament (ACL) injuries in female athletes, including modifiable and nonmodifiable sex-based risk factors and the implementation of ACL injury prevention programs.