bluuebunny/crossref_metadata_2025 huggingface dataset:
Workload and transmission data for the installation of a digital breast tomosynthesis system
Authors: Li Xinhua , Zhang Da , Liu Bob
Published: May 2013

Purpose:

Digital breast tomosynthesis (DBT) differs from conventional mammography in target/filter, kVp range, and imaging geometry. The aim of this study was to assess the breast input exposure of a DBT system by completing a workload survey of DBT installations, and to determine the parameters α, β, and γ in the Archer equation for the primary radiation generated by the clinical workload distributions.

Methods:

The authors conducted a retrospective survey of the x‐ray breast imaging performed between September 2011 and September 2012 in three clinical DBT rooms equipped with Selenia Dimensions systems (Hologic Inc., Bedford, MA). A total of 343 examinations were analyzed to calculate the workload (mA‐minute) and the primary air kerma at 1 m from the source (K1). Transmission curves were calculated for the primary radiation generated by the workload distributions of the DBT rooms, and were fitted to the Archer equation.

Results:

There were large variations in patient volume and workload in the three examination rooms. In all these rooms, the average tube voltage (kVp) was about 31, the average K1 per patient was 16–21 mGy, and the average mA‐minute per patient was 1.4–2.2 times higher than that of the mammography room described in NCRP Report No. 147. Most DBT screening examinations consisted of four two‐dimensional mammographic views plus four tomosynthesis scans; the numbers of views acquired in diagnostic examinations varied widely. Tomosynthesis scans contributed about 30% of total mA‐minute and about 50% of K1. For the primary radiation generated by the clinical workload distributions, α was similar to that of 40–45 kVp W/Al (target/filter), and α + β was similar to that of 30 kVp W/Al.

Conclusions:

The workload (mA‐minute and K1) distributions of mammographic examinations with DBT differ from conventional mammography. A field survey of patient volume and x‐ray tube usage is important for the shielding design of DBT facilities. The clinical workloads and transmission data presented in this paper may be useful for clinical medical physicists.
Longitudinal trends in speech tempo: The case of Queen Beatrix
Authors: Quené Hugo
Published: May 2013

Older talkers speak slower than young ones, but speech tempo has increased in the last decades. Have present-day older talkers slowed down with age or have they sped up with their community? This study investigates longitudinal patterns in articulation rate in formal speeches presented annually by Queen Beatrix between her ages 42 and 74. Her tempo decreased first and then increased in the last decade. Within a speech, acceleration and shortening increased longitudinally. These results suggest that this talker's preferred tempo has not decreased but increased longitudinally, presumably in accommodation to an increasing tempo in the Dutch language community.
Complex N-Heterocycle Synthesis via Iron-Catalyzed, Direct C–H Bond Amination
Authors: Hennessy Elisabeth T. , Betley Theodore A.
Published: May 2013

Closing the Cycle

Cyclic hydrocarbons that incorporate nitrogen in the ring are among the most heavily investigated compounds in medicinal chemistry.
Hennessy and Betley
(p.
591
) demonstrate an iron catalyst that forms a range of such cyclic compounds by inducing linear alkyl azides to curl back on themselves, inserting the nitrogen at one end into a carbon-hydrogen bond further down the chain. The reaction furthers a trend of C-H bond activation chemistry that forms elaborate products from relatively simple precursors, without the need to install activating groups at unreactive sites.
Seeing Gravitational Waves
Authors: Kasliwal Mansi M.
Published: May 2013

A suite of observatories will be needed to detect the visible electromagnetic counterpart of gravitational waves.
Widespread Production of Extracellular Superoxide by Heterotrophic Bacteria
Authors: Diaz Julia M. , Hansel Colleen M. , Voelker Bettina M. , Mendes Chantal M. , Andeer Peter F. , Zhang Tong
Published: May 2013

Sending Out an ROS

The global imprint of biological activity in aquatic environments is often considered a consequence of enzyme-mediated redox reactions that support metabolic activity, such as reducing oxygen during respiration. But some organisms also release redox-active reactive oxygen species (ROS) into the environment—to acquire trace metals or to prevent viral infections—which can influence global processes like nutrient availability and contaminant transport. Photosynthetic organisms like phytoplankton are thought to be the primary biological source of ROS in freshwater and marine environments. However,

Diaz
et al.

(p.
1223
, published online 2 May; see the Perspective by

Shaked and Rose

) now show that a broad range of ecologically and phylogenetically diverse heterotrophic bacteria also produce large quantities of superoxide. Production rates vary widely across 30 common bacterial isolates but in some cases were greater than production rates of phytoplankton. Because these bacteria do not require light to grow, they may be the dominant source of ROS in dark environments like the deep ocean, terrestrial soils, or lake sediments.
As Good as Chocolate
Authors: Palczewski Krzysztof , Kiser Philip D.
Published: May 2013

Structural details of how ligands bind to serotonin receptors should guide the development of pharmaceuticals with fewer side effects.

[Also see Reports by

Wang
et al.

and

Wacker
et al.

]
People Have Been Faking It for Years
Faking It
Manipulated Photography Before Photoshop

Mia Fineman, curator

Metropolitan Museum of Art, New York, through 27 January 2013. National Gallery of Art, Washington, DC, through 5 May. Museum of Fine Arts, Houston, 2 June to 25 August 2013. http://www.nga.gov/content/ngaweb/exhibitions/2013/faking.html
Faking It
Manipulated Photography Before Photoshop

by Mia Fineman

Metropolitan Museum of Art, New York, 2012. 296 pp. $60. ISBN 9780300185010.
Authors: Fitzpatrick Yael
Published: May 2013

Using examples from art, journalism, politics, commerce, and entertainment, the exhibition explores the manipulation of photographs from the 1840s through the early 1990s.
Toll-Like Receptor 4 Agonistic Antibody Promotes Innate Immunity against Severe Pneumonia Induced by Coinfection with Influenza Virus and Streptococcus pneumoniae
Authors: Tanaka Akitaka , Nakamura Shigeki , Seki Masafumi , Fukudome Kenji , Iwanaga Naoki , Imamura Yoshifumi , Miyazaki Taiga , Izumikawa Koichi , Kakeya Hiroshi , Yanagihara Katsunori , Kohno Shigeru
Published: May 2013

Coinfection with bacteria is a major cause of mortality during influenza epidemics. Recently, Toll-like receptor (TLR) agonists were shown to have immunomodulatory functions. In the present study, we investigated the effectiveness and mechanisms of the new TLR4 agonistic monoclonal antibody UT12 against secondary pneumococcal pneumonia induced by coinfection with influenza virus in a mouse model. Mice were intranasally inoculated withStreptococcus pneumoniae2 days after influenza virus inoculation. UT12 was intraperitoneally administered 2 h before each inoculation. Survival rates were significantly increased and body weight loss was significantly decreased by UT12 administration. Additionally, the production of inflammatory mediators was significantly suppressed by the administration of UT12. In a histopathological study, pneumonia in UT12-treated mice was very mild compared to that in control mice. UT12 increased antimicrobial defense through the acceleration of macrophage recruitment into the lower respiratory tract induced by c-Jun N-terminal kinase (JNK) and nuclear factor kappaB (NF-κB) pathway-dependent monocyte chemoattractant protein 1 (MCP-1) production. Collectively, these findings indicate that UT12 promoted pulmonary innate immunity and may reduce the severity of severe pneumonia induced by coinfection with influenza virus andS. pneumoniae. This immunomodulatory effect of UT12 improves the prognosis of secondary pneumococcal pneumonia and makes UT12 an attractive candidate for treating severe infectious diseases.
Characterization of the Native Form of Anthrax Lethal Factor for Use in the Toxin Neutralization Assay
Authors: Lu Hang , Catania Jason , Baranji Katalin , Feng Jie , Gu Mili , Lathey Janet , Sweeny Diane , Sanford Hannah , Sapru Kavita , Patamawenu Terry , Chen June-Home , Ng Alan , Fesseha Zenbework , Kluepfel-Stahl Stefanie , Minang Jacob , Alleva David
Published: May 2013

The cell-based anthrax toxin neutralization assay (TNA) is used to determine functional antibody titers of sera from animals and humans immunized with anthrax vaccines. The anthrax lethal toxin is a critical reagent of the TNA composed of protective antigen (PA) and lethal factor (LF), which are neutralization targets of serum antibodies. Cytotoxic potency of recombinant LF (rLF) lots can vary substantially, causing a challenge in producing a renewable supply of this reagent for validated TNAs. To address this issue, we characterized a more potent rLF variant (rLF-A) with the exact native LF amino acid sequence that lacks the additional N-terminal histidine and methionine residues present on the commonly used form of rLF (rLF-HMA) as a consequence of the expression vector. rLF-A can be used at 4 to 6 ng/ml (in contrast to 40 ng/ml rLF-HMA) with 50 ng/ml recombinant PA (rPA) to achieve 95 to 99% cytotoxicity. In the presence of 50 ng/ml rPA, both rLF-A and rLF-HMA allowed for similar potencies (50% effective dilution) among immune sera in the TNA. rPA, but not rLF, was the dominant factor in determining potency of serum samples containing anti-PA antibodies only or an excess of anti-PA relative to anti-rLF antibodies. Such anti-PA content is reflected in immune sera derived from most anthrax vaccines in development. These results support that 7- to 10-fold less rLF-A can be used in place of rLF-HMA without changing TNA serum dilution curve parameters, thus extending the use of a single rLF lot and a consistent, renewable supply.
Complete Genome Sequence of Glaciecola psychrophila Strain 170
T
Authors: Yin Jinlong , Chen Jing , Liu Guiming , Yu Yong , Song Lai , Wang Xumin , Qu Xiaobo
Published: May 2013

Here, we report the complete genome sequence of
Glaciecola psychrophila
strain 170
T
, a novel species of the genus
Glaciecola
, isolated from sea ice at high-latitude Arctic locations. The genome consists of a single chromosome (5,413,691 bp) and 5,363 genes. The genomics information will facilitate the study of the physiology, cold adaptation, and evolution of this genus.
Whole-Genome Sequences of Streptococcus tigurinus Type Strain AZ_3a and
S
.
tigurinus
1366, a Strain Causing Prosthetic Joint Infection
Authors: Gizard Yann , Zbinden Andrea , Schrenzel Jacques , François Patrice
Published: May 2013

Streptococcus tigurinus
, a novel member of the
Streptococcus mitis
group, was recently identified as a causative agent of invasive infections. We report the complete genome sequences of the
S. tigurinus
type strain AZ_3a and
S. tigurinus
strain 1366. The genome sequences assist in the characterization of virulence determinants of
S. tigurinus.
Structural and Functional Characterization of the Mumps Virus Phosphoprotein
Authors: Cox Robert , Green Todd J. , Purushotham Sangeetha , Deivanayagam Champion , Bedwell Gregory J. , Prevelige Peter E. , Luo Ming
Published: May 2013

The phosphoprotein (P) is virally encoded by the
Rhabdoviridae
and
Paramyxoviridae
in the order
Mononegavirales
. P is a self-associated oligomer and forms complexes with the large viral polymerase protein (L), the nucleocapsid protein (N), and the assembled nucleocapsid. P from different viruses has shown structural diversities even though their essential functions are the same. We systematically mapped the domains in mumps virus (MuV) P and investigated their interactions with nucleocapsid-like particles (NLPs). Similar to other P proteins, MuV P contains N-terminal, central, and C-terminal domains with flexible linkers between neighboring domains. By pulldown assays, we discovered that in addition to the previously proposed nucleocapsid binding domain (residues 343 to 391), the N-terminal region of MuV P (residues 1 to 194) could also bind NLPs. Further analysis of binding kinetics was conducted using surface plasmon resonance. This is the first observation that both the N- and C-terminal regions of a negative-strand RNA virus P are involved in binding the nucleocapsid. In addition, we defined the oligomerization domain (P
OD
) of MuV P as residues 213 to 277 and determined its crystal structure. The tetrameric MuV P
OD
is formed by one pair of long parallel α-helices with another pair in opposite orientation. Unlike the parallel orientation of each α-helix in the tetramer of Sendai virus P
OD
, this represents a novel orientation of a P
OD
where both the N- and the C-terminal domains are at either end of the tetramer. This is consistent with the observation that both the N- and the C-terminal domains are involved in binding the nucleocapsid.
Hypervariable Domain of Nonstructural Protein nsP3 of Venezuelan Equine Encephalitis Virus Determines Cell-Specific Mode of Virus Replication
Authors: Foy Niall J. , Akhrymuk Maryna , Shustov Alexander V. , Frolova Elena I. , Frolov Ilya
Published: May 2013

Venezuelan equine encephalitis virus (VEEV) is one of the most pathogenic members of the
Alphavirus
genus in the
Togaviridae
family. This genus is divided into the Old World and New World alphaviruses, which demonstrate profound differences in pathogenesis, replication, and virus-host interactions. VEEV is a representative member of the New World alphaviruses. The biology of this virus is still insufficiently understood, particularly the function of its nonstructural proteins in RNA replication and modification of the intracellular environment. One of these nonstructural proteins, nsP3, contains a hypervariable domain (HVD), which demonstrates very low overall similarity between different alphaviruses, suggesting the possibility of its function in virus adaptation to different hosts and vectors. The results of our study demonstrate the following. (i) Phosphorylation of the VEEV nsP3-specific HVD does not play a critical role in virus replication in cells of vertebrate origin but is important for virus replication in mosquito cells. (ii) The VEEV HVD is not required for viral RNA replication in the highly permissive BHK-21 cell line. In fact, it can be either completely deleted or replaced by a heterologous protein sequence. These variants require only one or two additional adaptive mutations in nsP3 and/or nsP2 proteins to achieve an efficiently replicating phenotype. (iii) However, the carboxy-terminal repeat in the VEEV HVD is indispensable for VEEV replication in the cell lines other than BHK-21 and plays a critical role in formation of VEEV-specific cytoplasmic protein complexes. Natural VEEV variants retain at least one of the repeated elements in their nsP3 HVDs.
The Interaction of the Cellular Export Adaptor Protein Aly/REF with ICP27 Contributes to the Efficiency of Herpes Simplex Virus 1 mRNA Export
Authors: Tian Xiaochen , Devi-Rao Gayathri , Golovanov Alexander P. , Sandri-Goldin Rozanne M.
Published: May 2013

Herpes simplex virus 1 (HSV-1) protein ICP27 enables viral mRNA export by accessing the cellular mRNA export receptor TAP/NXF, which guides mRNA through the nuclear pore complex. ICP27 binds viral mRNAs and interacts with TAP/NXF, providing a link to the cellular mRNA export pathway. ICP27 also interacts with the mRNA export adaptor protein Aly/REF, which binds cellular mRNAs and also interacts with TAP/NXF. Studies using small interfering RNA (siRNA) knockdown indicated that Aly/REF is not required for cellular mRNA export, and similar knockdown studies during HSV-1 infection led us to conclude that Aly/REF may be dispensable for viral RNA export. Recently, the structural basis of the interaction of ICP27 with Aly/REF was elucidated at atomic resolution, and it was shown that three ICP27 residues, W105, R107, and L108, interface with the RNA recognition motif (RRM) domain of Aly/REF. Here, to determine the role the interaction of ICP27 and Aly/REF plays during infection, these residues were mutated to alanine, and a recombinant virus, WRL-A, was constructed. Virus production was reduced about 10-fold during WRL-A infection, and export of ICP27 protein and most viral mRNAs was less efficient. We conclude that interaction of ICP27 with Aly/REF contributes to efficient viral mRNA export.
Response of Hepatitis C Virus to Long-Term Passage in the Presence of Alpha Interferon: Multiple Mutations and a Common Phenotype
Authors: Perales Celia , Beach Nathan M. , Gallego Isabel , Soria Maria Eugenia , Quer Josep , Esteban Juan Ignacio , Rice Charles , Domingo Esteban , Sheldon Julie
Published: May 2013

Cell culture-produced hepatitis C virus (HCV) has been subjected to up to 100 serial passages in human hepatoma cells in the absence or presence of different doses of alpha interferon (IFN-α). Virus survival, genetic changes, fitness levels, and phenotypic traits have been examined. While high initial IFN-α doses (increasing from 1 to 4 IU/ml) did not allow HCV survival beyond passage 40, a gradual exposure (from 0.25 to 10 IU/ml) allowed the virus to survive for at least 100 passages. The virus passaged in the presence of IFN-α acquired IFN-α resistance as evidenced by enhanced progeny production and viral protein expression in an IFN-α environment. A partial IFN-α resistance was also noted in populations passaged in the absence of IFN-α. All lineages acquired adaptative mutations, and multiple, nonsynonymous mutations scattered throughout the genome were present in IFN-α-selected populations. Comparison of consensus sequences indicates a dominance of synonymous versus nonsynonymous substitutions. IFN-α-resistant populations displayed decreased sensitivity to a combination of IFN-α and ribavirin. A phenotypic trait common to all assayed viral populations is the ability to increase shutoff host cell protein synthesis, accentuated in infections with IFN-α-selected populations carried out in the presence of IFN-α. The trait was associated with enhanced phosphorylation of protein kinase R (PKR) and eIF2α, although other contributing factors are likely. The results suggest that multiple, independent mutational pathways can confer IFN-α resistance to HCV and might explain why no unified picture has been obtained regarding IFN-α resistancein vivo.
Cellular Chaperonin CCTγ Contributes to Rabies Virus Replication during Infection
Authors: Zhang Jinyang , Wu Xiaopeng , Zan Jie , Wu Yongping , Ye Chengjin , Ruan Xizhen , Zhou Jiyong
Published: May 2013

Rabies, as the oldest known infectious disease, remains a serious threat to public health worldwide. The eukaryotic cytosolic chaperonin TRiC/CCT complex facilitates the folding of proteins through ATP hydrolysis. Here, we investigated the expression, cellular localization, and function of neuronal CCTγ during neurotropic rabies virus (RABV) infection using mouse N2a cells as a model. Following RABV infection, 24 altered proteins were identified by using two-dimensional electrophoresis and mass spectrometry, including 20 upregulated proteins and 4 downregulated proteins. In mouse N2a cells infected with RABV or cotransfected with RABV genes encoding nucleoprotein (N) and phosphoprotein (P), confocal microscopy demonstrated that upregulated cellular CCTγ was colocalized with viral proteins N and P, which formed a hollow cricoid inclusion within the region around the nucleus. These inclusions, which correspond to Negri bodies (NBs), did not form in mouse N2a cells only expressing the viral protein N or P. Knockdown of CCTγ by lentivirus-mediated RNA interference led to significant inhibition of RABV replication. These results demonstrate that the complex consisting of viral proteins N and P recruits CCTγ to NBs and identify the chaperonin CCTγ as a host factor that facilitates intracellular RABV replication. This work illustrates how viruses can utilize cellular chaperonins and compartmentalization for their own benefit.
Coexistence of allergic bronchopulmonary aspergillosis and allergic aspergillus sinusitis in a patient without clinical asthma
Authors: Ghosh Gopal , Sharma Brijesh , Chauhan Ajay , Chawla M P S
Published: May 2013

All patients with prolonged cough with a history of atopy, even if not clinically asthmatic, should be evaluated for allergic bronchopulmonary aspergillosis (ABPA); also, we suspect that we may miss the early diagnosis of ABPA if bronchial asthma is considered as a major criteria for the diagnosis of ABPA
The use of rituximab and bendamustine in treating chronic lymphocytic leukaemia (CLL) in end-stage renal disease (ESRD)
Authors: Shoji Jun , Lew Susie Q
Published: May 2013

A patient with a history of type 2 diabetes mellitus and chronic lymphocytic leukaemia has renal failure with large kidneys. The patient refused kidney biopsy to determine the aetiology of her renal failure. She uses peritoneal dialysis to treat renal failure. She received rituximab and bendamustine to treat chronic lymphocytic leukaemia. Adenopathy resolves with treatment and she does not experience any electrolyte disturbances or decrease in urine output as a result of chemotherapy in the setting of renal failure. Renal function did not recover with chemotherapy.
CLIMATE EFFECT ON WILDFIRE BURNED AREA IN ALBERTA (1961–2010)
Authors: LEE HUNG-I , WANG SHIH-LUEN , LI SAI-PING
Published: May 2013

The spread and burned areas of wildfires in Alberta, Canada during a 50 year period, from 1961 through 2010 are studied here. Meteorological factors that control the spread and burn area have been discussed for a long time. In this paper, we analyze the temperature rise that could drastically enhance the spread and average burned area of wildfires. A simple lattice model that mimics meteorological factors is also introduced to simulate the temperature effect on the spread and burned areas of wildfires. The numerical results demonstrate the temperature effects on wildfires when compared to the empirical data.
SYNCHRONIZATION BETWEEN TWO DIFFERENT HYPERCHAOTIC SYSTEMS WITH UNCERTAIN PARAMETERS
Authors: WANG XING-YUAN , YANG YU-HONG , FENG MING-KU
Published: May 2013

This paper studies the problem of chaos synchronization between two different hyperchaotic systems with uncertain parameters. Based on the Lyapunov stability theory, we obtain the sufficient condition of synchronization between two different hyperchaotic systems with uncertain parameters. A new adaptive controller with parameter update laws is designed to synchronize these chaotic systems. We proved it in theory with an uncertain hyperchaotic Lorenz system and an uncertain hyperchaotic Rössler system. Numerical results verified the validation of the proposed scheme.
CUMULANT ANALYSIS OF DETECTION OF RANDOM PROCESS USING A SCHOTTKY DIODE WITH δ-DOPING
Authors: KLYUEV A. V.
Published: May 2013

We present the results of cumulant analysis for detection of random process using a Schottky diode with δ-doping. The statistical characteristics of the output process of the detector, based on a Schottky diode with δ-doping, are investigated. We discuss noninertial and inertial detection mode. It was shown that at a relatively large dispersion of the input noise a noninertial detection mode occurs.
STUDY ON QUANTUM CORRELATIONS FOR CIRCUIT QED STATES
Authors: JI Y. H. , LIU Y. M.
Published: May 2013

We investigate the dynamic evolution behaviors of entanglement and geometric quantum discord of coupled superconducting qubits in circuit QED system. We carefully analyze the effect of cavity field quantum state on the quantum entanglement and quantum correlations dynamic behaviors of coupling superconducting qubits. The results show that when the cavity field is in coherent state, with the average photon number increasing, the quantum discord death (including entanglement death) would become more difficult to appear, that is to say prolonging the survival time of quantum correlations will be a benefit for keeping the quantum correlations. When the cavity field is in squeezed state, the squeezed amplitude parameters are all too big or too small to keep the system quantum correlations. However, the further study results show that with the initial relative phase of coupling superconducting increasing, qubits can also keep the quantum correlations.
EXTENDED SPHERICAL COLLAPSE AND THE ACCELERATING UNIVERSE
Authors: DEL POPOLO A. , PACE F. , LIMA J. A. S.
Published: May 2013

The influence of the shear stress and angular momentum on the nonlinear spherical collapse model is discussed in the framework of the Einstein–de Sitter and ΛCDM models. By assuming that the vacuum component is not clustering within the homogeneous nonspherical overdensities, we show how the local rotation and shear affect the linear density threshold for collapse of the nonrelativistic component (δc) and its virial overdensity (ΔV). It is also found that the net effect of shear and rotation in galactic scale is responsible for higher values of the linear overdensity parameter as compared with the standard spherical collapse model (no shear and rotation).
A HIGH-LEVEL TECHNIQUE FOR ESTIMATION AND OPTIMIZATION OF LEAKAGE POWER FOR FULL ADDER
Authors: SHRIVAS JAYRAM , AKASHE SHYAM , TIWARI NITESH
Published: May 2013

Optimization of power is a very important issue in low-voltage and low-power application. In this paper, we have proposed power gating technique to reduce leakage current and leakage power of one-bit full adder. In this power gating technique, we use two sleep transistors i.e., PMOS and NMOS. PMOS sleep transistor is inserted between power supply and pull up network. And NMOS sleep transistor is inserted between pull down network and ground terminal. These sleep transistors (PMOS and NMOS) are turned on when the circuit is working in active mode. And sleep transistors (PMOS and NMOS) are turned off when circuit is working in standby mode. We have simulated one-bit full adder and compared with the power gating technique using cadence virtuoso tool in 45 nm technology at 0.7 V at 27°C. By applying this technique, we have reduced leakage current from 2.935 pA to 1.905 pA and leakage power from 25.04μw to 9.233μw. By using this technique, we have reduced leakage power up to 63.12%.
SIMPLIFIED ANALYSIS OF LOW VELOCITY IMPACT ACTIONS ON SHALLOW DOMES
Authors: YANG YI , LAM NELSON , ZHANG LIHAI , GAD EMAD
Published: May 2013

This paper is concerned with a simplified approach of estimating the effects of the impact of a projectile on a circular dome. The procedure to be introduced involves simplifying the impactor (projectile) and the target (the dome) by a two-degree-of-freedom (2DOF) system which is made up of two lumped masses connected by elastic springs. This modeling approach has only been adapted for analyzing the impact response behavior of beams and plates. The original contributions of this paper is the development of equations and charts for estimating the value of the lumped mass and spring stiffness in the 2DOF lumped mass model to emulate the response behavior of circular domes. Linear elastic behavior of the dome is assumed but nonlinear behavior of the impactor has been taken into account. The developed calculation procedure has been validated and illustrated by case studies.
MODELING THE CHANGE OF BEACH PROFILE UNDER TSUNAMI WAVES: A COMPARISON OF SELECTED SEDIMENT TRANSPORT MODELS
Authors: LI LINLIN , HUANG ZHENHUA
Published: May 2013

In contrast to the efforts made to develop hydrodynamic models for large-scale tsunami propagation and run-up, little has been done to develop, test, and validate sediment transport models used to simulate tsunami-induced sediment movement. In this study, the performances of six widely-used sediment transport formulas are evaluated through case studies using an open source code XBeach, which is based on 2D depth-averaged nonlinear shallow water equations. Another open source code, Delft3D, is also used to see to what extent XBeach can give reliable results. The benchmarks used for case studies include three laboratory experiments and one field observation from a post-tsunami field survey conducted after the 2004 Indian tsunami. Our results show that most of the surveyed sediment transport formulas can give good results for laboratory-scale problems, but for real-scale problems, all six formulas failed to produce good results compared to those found in laboratory conditions. For laboratory-scale problems, both XBeach and Delft3D can predict satisfactory results with properly-chosen model parameters. For real tsunamis, high suspended sediment concentration may occur, and density stratification and hindered settling effect play an important role; therefore, Delft3D, with both hindered settling and density stratification being considered, may perform better than XBeach. The findings reported here will be useful for researchers and practitioners working on tsunami hazard mitigation.
INTERACTIVE DATA ENCRYPTION STRATEGY FOR DISTRIBUTED SIMULATION SYSTEM
Authors: LIN XIN , SHI WEIHUI , DU YONGXIANG
Published: May 2013

The distributed simulation system interoperation can be divided into six levels. Interactive data encryption can be completed in each level, lead to six encryption strategies: data field encryption, data package encryption, program module encryption, simulation application encryption, simulation node encryption, and simulation system encryption. There are four basic Encryption/decryption realization modes: serial modes with software or hardware realization, parallel modes based on embedded processor or FPGA/ASIC system. Large and Complex distributed simulation system may employ one or several encryption strategies and realization modes.
Geological controls on tunnelling in the chalk of Southwick Hill, Brighton
Authors: Bowden Andrew J.
Published: May 2013

Twin 12.5 m diameter, 470 m long road tunnels were constructed in the Newhaven Chalk Formation of Southwick Hill, NW of Brighton, UK. The tunnel was supported using shotcrete and untensioned bolts, the support being adjusted on site using the Q classification system and deformation monitoring. Other than some grade B4 chalk at one portal the ground conditions were similar to the optimistic prediction and significantly better than the conditions used for design, which were greatly influenced by poor quality core. Six metres of heading advance per 24 h day was normal in the 7 m by 12.5 m heading, peaking at 8 m in 24 h. This paper discusses the attempts to deal with conflicts in the site investigation data and the assessment of the ground reference conditions, and compares these with the actual ground conditions encountered. A summary of the main geological features affecting tunnel stability is presented.
Simulating liquids and solid-liquid interactions with lagrangian meshes
Authors: Clausen Pascal , Wicke Martin , Shewchuk Jonathan R. , O'Brien James F.
Published: May 2013

This article describes a Lagrangian finite element method that simulates the behavior of liquids and solids in a unified framework. Local mesh improvement operations maintain a high-quality tetrahedral discretization even as the mesh is advected by fluid flow. We conserve volume and momentum, locally and globally, by assigning to each element an independent rest volume and adjusting it to correct for deviations during remeshing and collisions. Incompressibility is enforced with per-node pressure values, and extra degrees of freedom are selectively inserted to prevent pressure locking. Topological changes in the domain are explicitly treated with local mesh splitting and merging. Our method models surface tension with an implicit formulation based on surface energies computed on the boundary of the volume mesh.

With this method we can model elastic, plastic, and liquid materials in a single mesh, with no need for explicit coupling. We also model heat diffusion and thermoelastic effects, which allow us to simulate phase changes. We demonstrate these capabilities in several fluid simulations at scales from millimeters to meters, including simulations of melting caused by external or thermoelastic heating.
Power-Efficient Predication Techniques for Acceleration of Control Flow Execution on CGRA
Authors: Han Kyuseung , Ahn Junwhan , Choi Kiyoung
Published: May 2013

Coarse-grained reconfigurable architecture typically has an array of processing elements which are controlled by a centralized unit. This makes it difficult to execute programs having control divergence among PEs without predication. However, conventional predication techniques have a negative impact on both performance and power consumption due to longer instruction words and unnecessary instruction-fetching decoding nullifying steps. This article reveals performance and power issues in predicated execution which have not been well-addressed yet. Furthermore, it proposes fast and power-efficient predication mechanisms. Experiments conducted through gate-level simulation show that our mechanism improves energy-delay product by 11.9% to 23.8% on average.
Functional Attachment of Soft Tissues to Bone: Development, Healing, and Tissue Engineering
Authors: Lu Helen H. , Thomopoulos Stavros
Published: May 2013

Connective tissues such as tendons or ligaments attach to bone across a multitissue interface with spatial gradients in composition, structure, and mechanical properties. These gradients minimize stress concentrations and mediate load transfer between the soft and hard tissues. Given the high incidence of tendon and ligament injuries and the lack of integrative solutions for their repair, interface regeneration remains a significant clinical challenge. This review begins with a description of the developmental processes and the resultant structure-function relationships that translate into the functional grading necessary for stress transfer between soft tissue and bone. It then discusses the interface healing response, with a focus on the influence of mechanical loading and the role of cell-cell interactions. The review continues with a description of current efforts in interface tissue engineering, highlighting key strategies for the regeneration of the soft tissue–to-bone interface, and concludes with a summary of challenges and future directions.
Kin Conflict in Seed Development: An Interdependent but Fractious Collective
Authors: Haig David
Published: May 2013

Seeds are complex structures that unite diploid maternal tissues with filial tissues that may be haploid (gametophyte), diploid (embryo), or triploid (endosperm). Maternal tissues are predicted to favor smaller seeds than are favored by filial tissues, and filial genes of maternal origin are predicted to favor smaller seeds than are favored by filial genes of paternal origin. Consistent with these predictions, seed size is determined by an interplay between growth of maternal integuments, which limits seed size, and of filial endosperm, which promotes larger seeds. Within endosperm, genes of paternal origin favor delayed cellularization of endosperm and larger seeds, whereas genes of maternal origin favor early cellularization and smaller seeds. The ratio of maternal and paternal gene products in endosperm contributes to the failure of crosses between different ploidy levels of the same species and crosses between species. Maternally expressed small-interfering RNAs (siRNAs) are predicted to associate with growth-enhancing genes.
(Invited) Growth Kinetics and Uniform Scaling-up of Graphene Synthesis
Authors: Celebi Kemal , Cole Matthew T. , Rupesinghe Nalin , Greenwood Paul , Tao Li , Akinwande Deji , Robertson John , Park Hyung Gyu , Teo Kenneth B.K.
Published: May 2013

Chemical vapor deposition on copper is the most widely used method to synthesize graphene at large scale. However, the clear understanding of the fundamental mechanisms that govern this synthesis is lacking. Using a vertical-flow, cold-wall reactor with short gas residence time we observe the early growths to study the kinetics of chemical vapor deposition of graphene on copper foils and demonstrate uniform synthesis at wafer scale. Our results indicate that the growth is limited by the catalytic dissociative dehydrogenation on the surface and copper sublimation hinders the graphene growth. We report an activation energy of 3.1 eV for ethylene-based graphene synthesis.
(Invited) Carbon 1D/2D Nanoelectronics: Advances in Synthesis and Integration
Authors: Parker Jason M. , Chen Xiangyu , Liyanage Luckshitha , Tang Alvin , Wong H.-S. Philip
Published: May 2013

We present incremental advances in carbon nanotube synthesis and in graphene applications. These advances include novel lateral growth of carbon nanotubes with fair alignment, demonstrations of limited control of carbon nanotube chirality distribution, a study of the reliability and robustness of graphene, and a characterization of atomic layer deposition onto carbon nanotubes.
(Invited) Theoretical Study of Silicene and Germanene
Authors: Houssa Michel , van den Broek Bas , Scalise Emilio , Pourtois Geoffrey , Afanas'ev Valery , Stesmans André
Published: May 2013

The structural and electronic properties of silicene and germanene on metallic and non-metallic substrates are investigated theoretically, using first-principles simulations. We first study the interaction of silicene with Ag(111) surfaces, focusing on the (4x4) silicene/Ag structure. Due to symmetry breaking in the silicene layer (nonequivalent number of top and bottom Si atoms), silicene is predicted to be semiconducting, with a computed energy gap of about 0.3 eV. However, the charge transfer occurring at the silicene/Ag(111) interface leads to an overall metallic system. We next investigate the interaction of silicene and germanene with hexagonal non-metallic substrates, namely ZnS and ZnSe. On reconstructed (semiconducting) (0001)ZnS or ZnSe surfaces, silicene and germanene are found to be semiconducting. Remarkably, the nature (indirect or direct) and magnitude of their energy band gap can be controlled by an out-of-plane electric field.
(Invited) Integration and Characterization of Graphene-Insulator-Graphene Junctions
Authors: Roy Tania , Joiner Corey , Hesabi Zohreh Razavi , Vogel Eric M.
Published: May 2013

Graphene-insulator-graphene tunnel junctions have been fabricated and characterized. The cleaning processes for chemical vapor deposited graphene and integration of barrier engineered atomic layer deposited tunnel dielectrics is presented. Initial results of device characterization demonstrate subthreshold slopes less than 100 mV/dec.
(Invited) Graphene Underneath Metals
Authors: Toriumi Akira , Nagashio Kosuke , Moriyama Takafumi , Ifuku Ryota
Published: May 2013

We discuss recent experimental observations of metal/graphene contacts in terms of intrinsic interfaces obtained with resist-free process by comparing with those made by the conventional lithographic fabrication steps.
(Invited) Graphene Based Tunable Schottky Diode for High Performance Devices
Authors: Heo Jinseong , Song Hyun Jae , Byun Kyung-Eun , Seo David S. , Park Seongjun
Published: May 2013

The unique physicochemical properties of graphene enable the various electronic applications, even it is a zero band gap semiconductor. To overcome the low on/off ratio of graphene device originated from zero band gap property, several types of graphene have been studied such as nanoribbon and bi-layered graphene. Here, we reported the new structural graphene transistor, tunable Schottky diode, with high on/off ratio. Since it does not accompanied with any structural deformation of graphene, intrinsic properties were also preserved. Schottky barrier was simply formed by transferring the CVD grown graphenes on hydrogenated silicon surfaces. By adjusting graphene’s work function, we got a threshold voltage shift with high on/off ratio, 105.
(Invited) Toward Ambient-Stable Molecular Gated Graphene-FET: A Donor/Acceptor Hybrid Architecture to Achieve Bandgap in Bilayer Graphene
Authors: Nourbakhsh Amirhasan , Cantoro Mirco , Heyns Marc M. , Sels Bert F , De Gendt Stefan
Published: May 2013

In this work we report a technique to improve the Ion/Ioff ratio in bilayer graphene FET by asymetrical doping of layers. Doping is achived by n-doping the bottom layer by depositing bilayer graphene flakes on NH2-SAM modified SiO2 substrate and hole doping the top layer via coating the device with a film of F4TCNQ-containing polystyrene. Asymmetric surface doping of bilayer graphene can induce an electric field between both layers which results in opening of an electronic bandgap due to symmetry breaking. DFT modelling shows an effective electric field of ~1.5 V/nm between the layers and field effect measurements show an increase of Ion/Ioff ratio in bilayer FET up to 135 due to opening of the bandgap also, a Schottky barrier of ~60 meV at the interface of the semiconducting bilayer graphene and the electric contact is observed.
Capacitance-Voltage Characteristics of Gate-All-Around InxGa1-XAs Nanowire Transistor
Authors: Khosru Quazi D. M. , Khan Saeed Uz Zaman , Hossain Md. Shafayat , Rahman Fahim Ur , Hossen Md. Obaidul , Zaman Rifat
Published: May 2013

This work demonstrates a self-consistent 2-D numerical model for calculating the charge profile and gate capacitance and therefore obtaining C-V characteristics of a gate-all-around III-V nanowire transistor with a high mobility In0.53Ga0.47As channel and atomic layer deposited Al2O3/20nm WN gate stacks which has recently been demonstrated experimentally. Finite element method is used to solve Poisson’s equation and Schrödinger’s equation in a coupled manner taking wave function penetration, energy level splitting and other quantum effects into account while calculating the charge profile and gate capacitance for different gate bias. The functional dependence of C-V characteristics on different physical/process parameters i.e. alloy composition, oxide thickness, fin-width, doping density are explored as well.
Improved Characteristics of GaSb MOS Capacitors by Ozone Post Deposition Treatment
Authors: Zhao Lianfeng , Tan Zhen , Wang Jing , Xu Jun
Published: May 2013

In this paper, we present the effects of Ozone post deposition treatment on Al2O3/GaSb MOS capacitors. It is found that after deposition of Al2O3 dielectrics by atomic layer deposition (ALD), in-situ Ozone post deposition treatment for five minutes can improve the interfacial and electrical properties of the Al2O3/GaSb MOS capacitors, reducing the interface state density (Dit) and gate leakage current. Dit near the mid-gap is reduced by ~10% after in-situ Ozone post deposition treatment. Explanations for the improved characteristics by in-situ Ozone post deposition treatment are proposed. It is believed that the effects of in-situ Ozone post deposition treatment is due to the reduction of oxygen vacancies and defects at the interface and in the dielectrics.
(Invited) Photoluminescence Efficiency of Germanium Dots Self-Assembled on Oxides
Authors: Lockwood David J. , Rowell Nelson L. , Barbagiovanni Eric G. , Goncharova Lyudmila V. , Simpson Peter J. , Berbezier Isabelle , Amiard Guillaume , Favre Luc , Ronda Antoine , Faustini Marco , Grosso David
Published: May 2013

Self-assembled Ge quantum dots were formed by in-situ thermal annealing of a thin amorphous Ge layer deposited by molecular beam epitaxy either on a thin porous TiO2 layer grown on SiO2 on Si(001) or directly on the SiO2 layer itself. For samples with dot diameters ranging from 10 to 35 nm, the dot photoluminescence (PL) appeared primarily as a wide near-infrared band peaked near 800 meV. The peak energy of the PL band reflects the average dot size and its shape depends on the dot size distribution. Using tight binding and effective mass theoretical models, we have analyzed the PL spectrum in terms of the dot size distribution. The observed size distribution determined from transmission electron and atomic force microscopy allowed the determination of the nonlinear increase in the PL efficiency with decreasing dot diameter. Although the absolute intensities of the PL from the samples vary, the calculated efficiency curves are all well fitted by straight lines on a log-log plot, with essentially the same slope for all samples, thereby demonstrating that under the weak confinement regime investigated here there is a universal power-law increase in PL efficiency with decreasing dot size. Knowing this generic PL efficiency, we show that it is possible to evaluate the size distribution of Ge dots from their PL energy dependence.
(Invited) Stress Simulations of Si- and Ge-Channel FinFETs for the 14 nm-Node and Beyond
Authors: Eneman Geert , Brunco David P. , Witters Liesbeth , Vincent Benjamin , Favia Paola , Hikavyy Andriy , De Keersgieter An , Mitard Jerome , Loo Roger , Veloso Anabela , Richard Olivier , Bender Hugo , Vandervorst Wilfried , Caymax Matty , Horiguchi Naoto , Collaert Nadine , Thean Aaron
Published: May 2013

This work studies the effectiveness of stressors for Si- and Ge-channel gate-last FinFETs in nested layouts with dimensions of the 14, 10 and 7 nm-nodes. P-type FinFETs with Si-channels can be efficiently boosted by SiGe source/drain (S/D) stressors, and provide higher mobility than relaxed Ge-channel pFinFETs. The highest pFET mobility is found for strained Ge-channels: in this case a SiGe Strain-Relaxed Buffer (SRB) with Ge < 90% leads to a channel mobility that is significantly higher than what is achievable with strained Si. For nFETs, a SiGe-SRB is the most efficient booster for Si-channels. Theoretically, the electron mobility of Ge fin sidewalls is very high, making Ge-channel nFinFETs a promising alternative, even without strain. SRBs are the most efficient stressors and are scalable beyond the 14 nm-node. Etching the fins in the S/D regions releases strain generated by the SRB, therefore raised S/D stressors are preferred over recessed for maximal mobility when combined with SRBs. Except for SRBs and S/D stressors, the other stressors studied in this work (contact etch-stop layers, stressed gates and contacts) are found to be inefficient in nested 14 nm-node layouts.
(Invited) Germanium Nanostructures in High-K Materials
Authors: Seidel Peter , Geyer Maximilian , Lehninger David , Schneider Frank , Klemm Volker , Heitmann Johannes
Published: May 2013

In this paper our recent research on Ge nanoparticles embedded in ZrO2 will be reviewed. Ge nanoparticles have been deposited by rf-cosputtering of Ge1.6ZrO2/ZrO2 superlattices and subse-quent annealing. TEM measurements confirmed the phase separation of the two compounds and the forming of ex-tended nanocrystalline Ge layers at 650°. These layers show a luminescence signal at 2.5 eV, which is contributed to defect luminescence.
GeSn Film Deposition Using Metal Organic Chemical Vapor Deposition
Authors: Suda Kohei , Uno Tomohiro , Miyakawa Tatsuya , Machida Hideaki , Ishikawa Masato , Sudo Hiroshi , Ohshita Yoshio , Ogura Atsushi
Published: May 2013

An approach of creating CMOS channel with GeSn is one of the post-scaling techniques and is widely considered to be promising to improve LSI performance. In this paper, we selected the metal-organic (MO) precursors to deposit GeSn and investigated their characteristics. We confirmed that it is possible to deposit GeSn on a substrate using the MOCVD technique.
(Invited) Indirect Conversion Digital X-Ray Imager Using an Amorphous Selenium Photoconductor
Authors: Abbaszadeh Shiva , Keshavarzi Rasoul , Wang Kai , Karim Karim S
Published: May 2013

In this work, we report preliminary results from a 32×32 pixel prototype array that integrates a-Si:H TFT pixels with optically sensitive lateral a-Se MSM detectors. The array was in-house fabricated and characterized. Recent advances in improving the wavelength sensitivity, dark current, photocurrent and quantum efficiency of the a-Se optically sensitive lateral device are also presented together with system-level characterization and the first image captured by the array.