bluuebunny/crossref_metadata_2025 huggingface dataset:
PIK3CA mutations in Peruvian patients with HER2-amplified and triple negative non-metastatic breast cancers
Authors: Castaneda Carlos A , Lopez-Ilasaca Marco , Pinto Joseph A , Chirinos-Arias Michelle , Doimi Franco , Neciosup Silvia P , Rojas Katerin I , Vidaurre Tatiana , Balko Justin M , Arteaga Carlos L , Gomez Henry L
Published: October 2014

PURPOSE:

To determine the frequency of PIK3CA mutations in a Peruvian cohort with HER2-amplified and triple negative breast cancers (TNBC).

METHODS:

We analyzed two cohorts of 134 primary non-metastatic breast cancer patients from Peru. Cohorts consisted of 51 hormone receptors (+)/HER2-amplified breast tumor patients surgically resected as first treatment included in the ALTTO trial (ALTTO cohort) and 81 TNBC patients with residual disease after neoadjuvant treatment (neoadjuvant cohort). Genomic DNA was extracted from paraffin-embedded tumor samples. Samples from the ALTTO and neoadjuvant cohorts were taken at biopsies and from residual tumors, respectively. PIK3CA mutations were detected by sequencing DNA fragments obtained by PCR amplification of exons and their flanking introns. All of the detected PIK3CA mutations were confirmed in a second independent run of sample testing.

RESULTS:

PIK3CA mutations were present in 21/134 cases (15.7%). Mutations in exon 9 and 20 were present in 10/134 (7.5%) and 11/134 (8.2%), respectively. No cases had mutations in both exons. Mutations in exon 9 consisted of E545A (seven cases), E545K (two cases) and E545Q (one case); while in exon 20, mutations consisted of H1047R (10 cases) and H1047L (one case). Compared to TNBC patients, HER2-amplified patients were more likely to have PIK3CA mutated (23% vs 9.6%; P = 0.034). There were no associations between mutational status of PIK3CA with estrogen receptor status (P = 0.731), progesterone receptor status (P = 0.921), age (P = 0.646), nodal status (P = 0.240) or histological grade (P = 1.00). No significant associations were found between PIK3CA mutational status and clinicopathological features.

CONCLUSIONS:

We found a similar frequency of PIK3CA mutations to that reported in other series. Although we did not include HR+/HER2 patients, those with HER2-amplified tumors were more likely to present PIK3CA mutations compared to patients with triple negative tumors.
Identify, Isolate, Inform: A 3-pronged Approach to Management of Public Health Emergencies
Authors: Koenig Kristi L.
Published: October 2014

During an evolving public health emergency, a simple algorithm for initial patient identification and management is essential for providers on the front lines. This article recommends a 3-pronged system of Identify, Isolate, Inform to describe the actions necessary in the first few minutes of encountering a potential Ebola patient. Application of the “vital sign zero” triage concept of early recognition of potential threats coupled with this novel algorithm will optimize protection of health care workers and the public health while concurrently providing a safe method for individual patient care. (Disaster Med Public Health Preparedness. 2014;0:1-2)
Evaluation of a Two-Phase Implementation of a Tier-2 (Small Group) Reading Intervention for Young Low-Progress Readers
Authors: Buckingham Jennifer , Wheldall Kevin , Beaman-Wheldall Robyn
Published: October 2014

In a response to intervention (RtI) model, reading is taught in increasingly intensive tiers of instruction. The aim of the study was to examine the efficacy of a Tier-2 (small group) literacy intervention for young struggling readers. This article focuses on the second phase of a randomised control trial involving 14 students in kindergarten as participants. In Phase 1 of the randomised control trial, the experimental group (E1) received the intervention for 1 hour, 4 days per week, for 3 school terms. The control group received regular classroom instruction. Large and statistically significant mean differences between groups were evident after 3 terms on 2 of 4 measures — the Martin and Pratt Nonword Reading Test and the Burt Reading Test, which measure phonological recoding and single word reading, respectively. Very large effect sizes were found. In Phase 2, the original control group received the intervention in the same way (E2). Testing at the end of Phase 2 confirmed the intervention's large effect on phonological recoding, but the results for the 3 other tests showed no acceleration in the Phase 2 experimental group (E2). This study evaluates the efficacy of the trialled intervention, adds to the research literature on Tier-2 interventions for young struggling readers, and yields practical implications for schools that offer literacy interventions without a strong RtI framework.
Rethinking “Great Commerce” and the Hometown Economy
Authors: Spaulding Robert Mark
Published: October 2014

This essay examines home towns in the “Third Germany,” and suggests that important assumptions about the insularity of the hometown economy might need revision. Ironically, a revised understanding of hometown economies that sees them as active participants in long-distance trade networks can help to confirm Mack Walker's core insights about the resilient strength of German home towns.
Bilingualism in Medieval Europe: Germans and Slavs in Helmold of Bosau'sChronicle
Authors: Rossignol Sébastien
Published: October 2014

Having described the countries of the “numerous peoples of the Slavs,” the late twelfth-century chronicler Helmold of Bosau added, “If you consider Hungary as a part of Slavania, as some would suggest, because it does not differ by customs or by language, the area of the Slavic language extends so far that a proper estimate is quite lacking.” These few words indicate how clearly local the chronicler's horizon was—the farther away from Wagria, the fuzzier his information. At the same time, though, Helmold made plain that the Slavic language was for him an essential element of what Slavania was. As a parish priest at the forefront of missionary and settlement activities, Helmold wrote a chronicle that is a unique source of information for intercultural interactions between Germans and Slavs during the high medieval colonization period.
Effect of dietary extruded linseed, verbascoside and vitamin E supplements on yield and quality of milk in Lacaune ewes
Authors: Casamassima Donato , Nardoia Maria , Palazzo Marisa , Vizzarri Francesco , D‘Alessandro Angela Gabriella , Corino Carlo
Published: October 2014

Milk yield and milk qualitative parameters were evaluated in Lacaune ewes on a diet supplemented with extruded linseed, verbascoside and vitamin E. A 98 d-trial was conducted on 44 ewes and started 40±2 d post partum. The animals were divided into four homogeneous groups of eleven animals each; one control group (CON) without extruded linseed and dietary supplements, and the diet of the other three experimental groups was enhanced with extruded linseed (L group), extruded linseed-verbascoside (LVB group), and extruded linseed-verbascoside-vitamin E (LVBE group). All animals individually received an isoenergetic diet, consisting of 700 g concentrated feed and meadow hay ad libitum. Body weight, body condition score, milk yield and milk qualitative parameters were assessed. LVB and LVBE groups resulted in a significant improvement (P<0·05) in milk yield due to the verbascoside supplementation. The extruded linseed supplementation L, LVB and LVBE groups produced a milk fat increase and a better milk fatty acid profile in terms of a higher monounsaturated fatty acid (MUFA), polyunsaturated fatty acid (PUFA) and conjugated linoleic acid (CLA) content and a reduced saturated fatty acid (SFA) content, a lowern-6/n-3 ratio and atherogenic and thrombogenic index. The dietary verbascoside supplementation in the LVB and LVBE group resulted in a better milk quality due to the low cholesterol level and higher vitamin A and E contents, in addition to an increased oxidative stability highlighted by the lower thiobarbituric acid reactive substances (TBARS) level. Thus, the addition of extruded linseed and verbascoside supplements improved milk yield and quality both from a chemical and nutritive point of view.
Robust and fast 3-D scan registration using normal distributions transform with supervoxel segmentation
Authors: Kim Ji W. , Lee Beom H.
Published: October 2014

This paper presents what is termed as the supervoxel normal distributions transform (SV-NDT), a novel three-dimensional (3-D) registration algorithm which improves the performance of the three-dimensional normal distributions transform (3-D NDT) significantly. The 3-D NDT partitions a model scan using a 3-D regular grid. Generating normal distributions using the 3-D regular grid causes considerable information loss because the 3-D regular grid does not use any information pertaining to the local surface structures of the model scan. The best type of surface (the constituent unit of each scan) for modeling with one normal distribution is known to be the plane. The SV-NDT reduces the loss of information using a supervoxel-generating algorithm at the partitioning stage. In addition, it uses the information of the local surface structures from the data scan by replacing the Euclidean distance with a function that uses local geometries as well as the Euclidean distance when each point in the data scan is matched to the corresponding normal distribution. Experiments demonstrate that the use of the supervoxel-generating algorithm increases the modeling accuracy of the normal distributions and that the proposed 3-D registration algorithm outperforms the 3-D NDT and other widely used 3-D registration algorithms in terms of robustness and speed on both synthetic and real-world datasets. Additionally, the effect of changing the function to create correspondences is also verified.
NUMBER ATTRACTION EFFECTS IN NEAR-NATIVE SPANISH SENTENCE COMPREHENSION
Authors: Jegerski Jill
Published: October 2014

Grammatical agreement phenomena such as verbal number have long been of fundamental interest in the study of second language (L2) acquisition. Previous research from the perspective of sentence processing has documented nativelike behavior among nonnative participants but has also relied almost exclusively on grammar violation paradigms. The present investigation examined the online comprehension of subject-verb number agreement by native and nonnative speakers of Mexican Spanish using the more subtle agreement attraction paradigm, with stimuli grammatical in both conditions, in addition to a nonlocal grammaticality paradigm. The results of a self-paced reading experiment confirmed that nonnatives can acquire nativelike online sensitivity to verbal number agreement, even without grammar errors, and that such sensitivity develops only at very high levels of L2 proficiency.
Review of BRD pathogenesis: the old and the new
Authors: Mosier Derek
Published: October 2014

The pathogenesis of bovine respiratory disease (BRD) is determined by a complex interaction of environmental, infectious, and host factors. Environment trends could impact feedlot cattle by increasing their level of stress. The polymicrobial nature of BRD produces synergies between infectious agents that can alter pathogenesis. However, the nature of the host response to these environmental and infectious challenges largely determines the characteristics of the progression and outcome of BRD.
Optimal measures for characterizing water-rich super-Earths
Authors: Madhusudhan Nikku , Redfield Seth
Published: October 2014

The detection and atmospheric characterization of super-Earths is one of the major frontiers of exoplanetary science. Currently, extensive efforts are underway to detect molecules, particularly H2O, in super-Earth atmospheres. In the present work, we develop a systematic set of strategies to identify and observe potentially H2O-rich super-Earths that provide the best prospects for characterizing their atmospheres using existing instruments. First, we provide analytic prescriptions and discuss factors that need to be taken into account while planning and interpreting observations of super-Earth radii and spectra. We discuss how observations in different spectral bandpasses constrain different atmospheric properties of a super-Earth, including radius and temperature of the planetary surface as well as the mean molecular mass, the chemical composition and thermal profile of the atmosphere. In particular, we caution that radii measured in certain bandpasses can induce biases in the interpretation of the interior compositions. Second, we investigate the detectability of H2O-rich super-Earth atmospheres using the Hubble Space Telescope Wide Field Camera 3 spectrograph as a function of the planetary properties and stellar brightness. We find that highly irradiated super-Earths orbiting bright stars, such as 55 Cancri e, present better candidates for atmospheric characterization compared to cooler planets such as GJ 1214b even if the latter orbit lower-mass stars. Besides being better candidates for both transmission and emission spectroscopy, hotter planets offer higher likelihood of cloud-free atmospheres which aid tremendously in the observation and interpretation of spectra. Finally, we present case studies of two super-Earths, GJ 1214b and 55 Cancri e, using available data and models of their interiors and atmospheres.
Genomic catastrophes frequently arise in esophageal adenocarcinoma and drive tumorigenesis
Authors: Nones Katia , Waddell Nicola , Wayte Nicci , Patch Ann-Marie , Bailey Peter , Newell Felicity , Holmes Oliver , Fink J. Lynn , Quinn Michael C. J. , Tang Yue Hang , Lampe Guy , Quek Kelly , Loffler Kelly A. , Manning Suzanne , Idrisoglu Senel , Miller David , Xu Qinying , Waddell Nick , Wilson Peter J. , Bruxner Timothy J. C. , Christ Angelika N. , Harliwong Ivon , Nourse Craig , Nourbakhsh Ehsan , Anderson Matthew , Kazakoff Stephen , Leonard Conrad , Wood Scott , Simpson Peter T. , Reid Lynne E. , Krause Lutz , Hussey Damian J. , Watson David I. , Lord Reginald V. , Nancarrow Derek , Phillips Wayne A. , Gotley David , Smithers B. Mark , Whiteman David C. , Hayward Nicholas K. , Campbell Peter J. , Pearson John V. , Grimmond Sean M. , Barbour Andrew P.
Published: October 2014

Oesophageal adenocarcinoma (EAC) incidence is rapidly increasing in Western countries. A better understanding of EAC underpins efforts to improve early detection and treatment outcomes. While large EAC exome sequencing efforts to date have found recurrent loss-of-function mutations, oncogenic driving events have been underrepresented. Here we use a combination of whole-genome sequencing (WGS) and single-nucleotide polymorphism-array profiling to show that genomic catastrophes are frequent in EAC, with almost a third (32%, n=40/123) undergoing chromothriptic events. WGS of 22 EAC cases show that catastrophes may lead to oncogene amplification through chromothripsis-derived double-minute chromosome formation (MYC and MDM2) or breakage-fusion-bridge (KRAS, MDM2 and RFC3). Telomere shortening is more prominent in EACs bearing localized complex rearrangements. Mutational signature analysis also confirms that extreme genomic instability in EAC can be driven by somatic BRCA2 mutations. These findings suggest that genomic catastrophes have a significant role in the malignant transformation of EAC.
Vesicle-based artificial cells as chemical microreactors with spatially segregated reaction pathways
Authors: Elani Yuval , Law Robert V. , Ces Oscar
Published: October 2014

In the discipline of bottom-up synthetic biology, vesicles define the boundaries of artificial cells and are increasingly being used as biochemical microreactors operating in physiological environments. As the field matures, there is a need to compartmentalize processes in different spatial localities within vesicles, and for these processes to interact with one another. Here we address this by designing and constructing multi-compartment vesicles within which an engineered multi-step enzymatic pathway is carried out. The individual steps are isolated in distinct compartments, and their products traverse into adjacent compartments with the aid of transmembrane protein pores, initiating subsequent steps. Thus, an engineered signalling cascade is recreated in an artificial cellular system. Importantly, by allowing different steps of a chemical pathway to be separated in space, this platform bridges the gap between table-top chemistry and chemistry that is performed within vesicles.
Comparing near-infrared conventional diffuse reflectance spectroscopy and hyperspectral imaging for determination of the bulk properties of solid samples by multivariate regression: determination of Mooney viscosity and plasticity indices of natural rubber
Authors: Juliano da Silva Carlos , Pasquini Celio
Published: October 2014

Bulk properties of natural rubber are determined by hyperspectral imaging and conventional spectroscopy in the near-infrared region.
Ultrasensitive electrochemical biosensing for DNA using quantum dots combined with restriction endonuclease
Authors: Zhang Can , Lou Jing , Tu Wenwen , Bao Jianchun , Dai Zhihui
Published: October 2014

A sensitive platform using endonuclease and AuNPs as well as environmental Bi film for the detection of DNA has been developed.
Out of the active site binding pocket for carbonic anhydrase inhibitors
Authors: D'Ambrosio Katia , Carradori Simone , Monti Simona M. , Buonanno Martina , Secci Daniela , Vullo Daniela , Supuran Claudiu T. , De Simone Giuseppina
Published: October 2014

2-Benzylsulfinylbenzoic acid binds to human carbonic anhydrase II in a mode completely different from any other class of carbonic anhydrase inhibitors investigated so far.
Molecular characterization of organic content of soot along the centerline of a coflow diffusion flame
Authors: Cain Jeremy , Laskin Alexander , Kholghy Mohammad Reza , Thomson Murray J. , Wang Hai
Published: October 2014

HR-MS speciation of young soot produced in a coflow diffusion flame reveal an array of ‘aliphatic’ and ‘aromatic’ CxHyOzconstituents.
Nanoscale Co-based catalysts for low-temperature CO oxidation
Authors: Wang Xi , Zhong Wei , Li Yingwei
Published: October 2014

A novel MOF-derived metallic cobalt-based catalyst for low-temperature CO oxidation was developed. This catalyst exhibited high catalytic activity even at a temperature as low as −30 °C and improved tolerance of moisture as compared to other Co-based materials.
Hydration and ion pair formation in common aqueous La(iii) salt solutions – a Raman scattering and DFT study
Authors: Rudolph Wolfram W. , Irmer Gert
Published: October 2014

Left hand side: Raman spectrum of a 0.622 mol L−1La(ClO4)3(aq). Weak, polarized band at 343 cm−1assigned to symmetric La–O stretch of [La(OH2)9]3+. Bands at 463 and 630 cm−1due to ClO4−(aq). The inset shows the isotropic band in more detail. Right hand side: Structure of [La(OH2)9]3+(symmetryD3).
Fluorescence axial nanotomography with plasmonics
Authors: Cade Nicholas I. , Fruhwirth Gilbert O. , Krasavin Alexey V. , Ng Tony , Richards David
Published: October 2014

We present a novel imaging technique with super-resolution axial sensitivity, exploiting the changes in fluorescence lifetime above a plasmonic substrate. Using conventional confocal fluorescence lifetime imaging, we show that it is possible to deliver down to 6 nm axial position sensitivity of fluorophores in whole biological cell imaging. We employ this technique to map the topography of the cellular membrane, and demonstrate its application in an investigation of receptor-mediated endocytosis in carcinoma cells.
Decomposition of RNA methylome reveals co-methylation patterns induced by latent enzymatic regulators of the epitranscriptome
Authors: Liu Lian , Zhang Shao-Wu , Zhang Yu-Chen , Liu Hui , Zhang Lin , Chen Runsheng , Huang Yufei , Meng Jia
Published: October 2014

Biochemical modifications to mRNA, especially N6-methyladenosine (m6A) and 5-methylcytosine (m5C), have been recently shown to be associated with crucial biological functions.
Distinguishing the influence of structural and energetic disorder on electron transport in fullerene multi-adducts
Authors: Steiner Florian , Foster Samuel , Losquin Arthur , Labram John , Anthopoulos Thomas D. , Frost Jarvist M. , Nelson Jenny
Published: October 2014

A combination of coarse-grained molecular dynamics and kinetic Monte-Carlo modeling shows that electron transport in fullerene multi-adducts is limited by energetic disorder due to different isomers rather than by structural disorder.
The role of ozone in the ozonation process of graphene oxide: oxidation or decomposition?
Authors: Yang Feng , Zhao Meilian , Wang Zhen , Ji Hongyun , Zheng Baozhan , Xiao Dan , Wu Li , Guo Yong
Published: October 2014

We took ozonation as an effective method to re-oxidize graphene oxide (GO) and discussed the behaviour of ozone in ozonation process of graphene oxide according to the changes of optical properties, compositions and structure. The results indicated that the ozonation process may involve the oxidation stage and decomposition stage. The fluorescence shifted blue with prolonging ozonation time.
One step cathodically electrodeposited [Tb2(BDC)3(H2O)4]n thin film as a luminescent probe for Cu2+ detection
Authors: Wang Yi , Chu Tianshu , Yu Minghao , Liu Huiping , Yang Yangyi
Published: October 2014

A luminescent [Tb2(BDC)3(H2O)4]n film with a leaf-like morphology is fabricated on FTO by electrochemical method, the film exhibits highly selective detection of Cu2+.
Ligand substitution and electron transfer reactions of trans-(diaqua)(salen)manganese(iii) with oxalate: an experimental and computational study
Authors: Kar Akshaya K. , Acharya Achyut N. , Mundlapati V. Rao , Pradhan Guru C. , Biswal Himansu S. , Dash Anadi C.
Published: October 2014

MnIII(salen)(OH2)2+ undergoes reversible anation by HOX−via Ia mechanism followed by proton controlled electron transfer involving MnIII(salen)(HOX) and H2OX.
A highly sensitive gold nanoparticle bioprobe based electrochemical immunosensor using screen printed graphene biochip
Authors: Lim Syazana Abdullah , Yoshikawa Hiroyuki , Tamiya Eiichi , Yasin Hartini Mohd , Ahmed Minhaz Uddin
Published: October 2014

This study describes a highly sensitive electrochemical immunosensor for the detection of human chorionic gonadotropin (hCG) that uses gold nanoparticles (AuNP) as the electrochemical label and graphene as electrode material.
Transition-metal-free controlled polymerization for poly(p-aryleneethynylene)s
Authors: Sanji Takanobu , Motoshige Asahi , Komiyama Hideaki , Kakinuma Junko , Ushikubo Rie , Watanabe Satoru , Iyoda Tomokazu
Published: October 2014

A catalytic amount of fluoride anions promoted the polymerization of 1-pentafluorophenyl-4-[(trimethylsilyl)ethynyl]benzene, providing a high-molecular-weight polymer in a chain-growth-like manner.
A CMP-based method for tunable, cell-mediated gene delivery from collagen scaffolds
Authors: Urello M. A. , Kiick K. L. , Sullivan M. O.
Published: October 2014

Collagen mimetic peptides (CMP)s were used to tailor release vs. retention of DNA polyplexes from collagen while preserving polyplex activity.
New sulfone-based electron-transport materials with high triplet energy for highly efficient blue phosphorescent organic light-emitting diodes
Authors: Jeon Soon Ok , Earmme Taeshik , Jenekhe Samson A.
Published: October 2014

Highly efficient blue phosphorescent organic light emitting diodes have been developed using novel sulfone-based electron transport materials (SPDP, SPDQ, and SPPP) with high triplet energy. The blue phosphorescent devices combine high quantum efficiency (19.6%) with high current efficiency (33.6 cd A−1).
TransCap: a monolithically integrated supercapacitor and electrolyte-gated transistor
Authors: Sayago J. , Shafique U. , Soavi F. , Cicoira F. , Santato C.
Published: October 2014

We report the proof-of-concept of the TransCap, a monolithically integrated device that exhibits the storage properties of a supercapacitor and the low-voltage operation of an electrolyte-gated transistor.
Impedance spectroscopic characterization of gadolinium substituted cobalt ferrite ceramics
Authors: Rahman Md. T. , Ramana C. V.
Published: October 2014

Gadolinium (Gd) substituted cobalt ferrites (CoFe2−xGdxO4, referred to CFGO) with variable Gd content (x = 0.0–0.4) have been synthesized by solid state ceramic method. The crystal structure and impedance properties of CFGO compounds have been evaluated. X-ray diffraction measurements indicate that CFGO crystallize in the inverse spinel phase. The CFGO compounds exhibit lattice expansion due to substitution of larger Gd ions into the crystal lattice. Impedance spectroscopy analysis was performed under a wide range of frequency (f = 20 Hz–1 MHz) and temperature (T = 303–573 K). Electrical properties of Gd incorporated Co ferrite ceramics are enhanced compared to pure CoFe2O4 due to the lattice distortion. Impedance spectroscopic analysis illustrates the variation of bulk grain and grain-boundary contributions towards the electrical resistance and capacitance of CFGO materials with temperature. A two-layer heterogeneous model consisting of moderately conducting grain interior (ferrite-phase) regions separated by insulating grain boundaries (resistive-phase) accurately account for the observed temperature and frequency dependent electrical characteristic of CFGO ceramics.
Determining conductivity and mobility values of individual components in multiphase composite Cu1.97Ag0.03Se
Authors: Day Tristan W. , Zeier Wolfgang G. , Brown David R. , Melot Brent C. , Snyder G. Jeffrey
Published: October 2014

The intense interest in phase segregation in thermoelectrics as a means to reduce the lattice thermal conductivity and to modify the electronic properties from nanoscale size effects has not been met with a method for separately measuring the properties of each phase assuming a classical mixture. Here, we apply effective medium theory for measurements of the in-line and Hall resistivity of a multiphase composite, in this case Cu1.97Ag0.03Se. The behavior of these properties with magnetic field as analyzed by effective medium theory allows us to separate the conductivity and charge carrier mobility of each phase. This powerful technique can be used to determine the matrix properties in the presence of an unwanted impurity phase, to control each phase in an engineered composite, and to determine the maximum carrier concentration change by a given dopant, making it the first step toward a full optimization of a multiphase thermoelectric material and distinguishing nanoscale effects from those of a classical mixture.
Physical origin of nonlinear transport in organic semiconductor at high carrier densities
Authors: Li Ling , Lu Nianduan , Liu Ming
Published: October 2014

The charge transport in some organic semiconductors exhibits nonlinear properties and further universal power-law scaling with both bias and temperature. The physical origin of this behavior is investigated here by using variable-range hopping theory. The results indicate that this nonlinear behavior can be well explained by variable-range hopping theory. In the high temperature regime, charge transport is thermally activated. However, for the low temperature case, field-assisted tunneling will be dominant, which is responsible for the nonlinear characteristics observed by experiment. The comparison between the theoretical calculation and recent experimental data is also presented.
Pulse widths dependence of programming and erasing behaviors for diamond like carbon based resistive switching memories
Authors: Xu Jianlong , Xie Dan , Zhang Chenhui , Zhang Xiaowen , Peng Pinggang , Fu Di , Qian He , Ren Tian-ling , Liu Litian
Published: October 2014

We report the influences of pulse widths on the programming and erasing characteristics of diamond-like carbon films based resistive random access memory. The device can be only programmed with pulses wider than 50 ns for SET operations when the pulse voltage is 1.2 V and erased with pulses narrower than 25 ns for RESET operations when the pulse voltage is 0.4 V. The formation, rupture, and re-growth of the conductive sp2-like graphitic filaments are proposed to be responsible for the resistive switching behaviors, based on which the pulse widths dependences on its programming and erasing properties can be further explained.
Subgrid-scale modeling for implicit large eddy simulation of compressible flows and shock-turbulence interaction
Authors: Hickel Stefan , Egerer Christian P. , Larsson Johan
Published: October 2014

We derive and analyze a model for implicit Large Eddy Simulation (LES) of compressible flows that is applicable to a broad range of Mach numbers and particularly efficient for LES of shock-turbulence interaction. Following a holistic modeling philosophy, physically sound turbulence modeling and numerical modeling of unresolved subgrid scales (SGS) are fully merged, in a manner quite different from that of traditional implicit LES approaches. The implicit subgrid model is designed in such a way that asymptotic consistency with incompressible turbulence theory is maintained in the low Mach number limit. Compressibility effects are properly accounted for by a novel numerical flux function, which can capture strong shock waves in supersonic flows and also ensures an accurate representation of smooth waves and turbulence without excessive numerical dissipation. Simulations of shock-tube problems, Noh's three-dimensional implosion problem, large-scale forced and decaying three-dimensional homogeneous isotropic turbulence, supersonic turbulent boundary layer flows, and a Mach = 2.88 compression-expansion ramp flow demonstrate the good performance of the SGS model; across this range of flows, predictions are in excellent agreement with theory, direct numerical simulations, and experimental reference data. Results for implicit LES of canonical shock-turbulence interaction are compared with results of explicit LES using the dynamic Smagorinsky model. The analysis shows that details of the numerical method used for shock capturing clearly outweigh the effect of different turbulence modeling strategies in explicit and implicit LES. The implicit LES model recovers the ideal 2nd-order grid convergence of shock-capturing errors that has been predicted using Rapid Distortion Theory. The dynamic Smagorinsky model in conjunction with a hybrid method that combines sixth-order central differences with a seventh-order weighted essentially non-oscillatory scheme yields turbulence statistics that are very similar to the implicit LES results. However, while the explicit LES requires a tailored high-order low-dissipative numerical method that applies numerical dissipation only in shock normal direction, no such ad hoc adjustments are necessary with the proposed implicit LES method.
Networks of coupled circuits: From a versatile toggle switch to collective coherent behavior
Authors: Labavić Darka , Meyer-Ortmanns Hildegard
Published: October 2014

We study the versatile performance of networks of coupled circuits. Each of these circuits is composed of a positive and a negative feedback loop in a motif that is frequently found in genetic and neural networks. When two of these circuits are coupled with mutual repression, the system can function as a toggle switch. The variety of its states can be controlled by two parameters as we demonstrate by a detailed bifurcation analysis. In the bistable regimes, switches between the coexisting attractors can be induced by noise. When we couple larger sets of these units, we numerically observe collective coherent modes of individual fixed-point and limit-cycle behavior. It is there that the monotonic change of a single bifurcation parameter allows one to control the onset and arrest of the synchronized oscillations. This mechanism may play a role in biological applications, in particular, in connection with the segmentation clock. While tuning the bifurcation parameter, also a variety of transient patterns emerges upon approaching the stationary states, in particular, a self-organized pacemaker in a completely uniformly equipped ensemble, so that the symmetry breaking happens dynamically.
A matter of quantum voltages
Authors: Sellner Bernhard , Kathmann Shawn M.
Published: October 2014

Voltages inside matter are relevant to crystallization, materials science, biology, catalysis, and aqueous chemistry. The variation of voltages in matter can be measured by experiment, however, modern supercomputers allow the calculation of accurate quantum voltages with spatial resolutions of bulk systems well beyond what can currently be measured provided a sufficient level of theory is employed. Of particular interest is the Mean Inner Potential (Vo) – the spatial average of these quantum voltages referenced to the vacuum. Here we establish a protocol to reliably evaluate Vo from quantum calculations. Voltages are very sensitive to the distribution of electrons and provide metrics to understand interactions in condensed phases. In the present study, we find excellent agreement with measurements of Vo for vitrified water and salt crystals and demonstrate the impact of covalent and ionic bonding as well as intermolecular/atomic interactions. Certain aspects in this regard are highlighted making use of simple model systems/approximations. Furthermore, we predict Vo as well as the fluctuations of these voltages in aqueous NaCl electrolytes and characterize the changes in their behavior as the resolution increases below the size of atoms.
Nonreciprocal wave scattering on nonlinear string-coupled oscillators
Authors: Lepri Stefano , Pikovsky Arkady
Published: October 2014

We study scattering of a periodic wave in a string on two lumped oscillators attached to it. The equations can be represented as a driven (by the incident wave) dissipative (due to radiation losses) system of delay differential equations of neutral type. Nonlinearity of oscillators makes the scattering non-reciprocal: The same wave is transmitted differently in two directions. Periodic regimes of scattering are analyzed approximately, using amplitude equation approach. We show that this setup can act as a nonreciprocal modulator via Hopf bifurcations of the steady solutions. Numerical simulations of the full system reveal nontrivial regimes of quasiperiodic and chaotic scattering. Moreover, a regime of a “chaotic diode,” where transmission is periodic in one direction and chaotic in the opposite one, is reported.
An analytical study on the diffraction quality factor of open cavities
Authors: Huang Y. J. , Yeh L. H. , Chu K. R.
Published: October 2014

Open cavities are often employed as interaction structures in a new generation of coherent millimeter, sub-millimeter, and terahertz (THz) radiation sources called the gyrotron. One of the open ends of the cavity is intended for rapid extraction of the radiation generated by a powerful electron beam. Up to the sub-THz regime, the diffraction loss from this open end dominates over the Ohmic losses on the walls, which results in a much lower diffraction quality factor (Qd) than the Ohmic quality factor (Qohm). Early analytical studies have led to various expressions for Qd and shed much light on its properties. In this study, we begin with a review of these studies, and then proceed with the derivation of an analytical expression for Qd accurate to high order. Its validity is verified with numerical solutions for a step-tunable cavity commonly employed for the development of sub-THz and THz gyrotrons. On the basis of the results, a simplified equation is obtained which explicitly expresses the scaling laws of Qd with respect to mode indices and cavity dimensions.
Grain and the concomitant ferroelectric domain size dependent physical properties of Ba0.85Ca0.15Zr0.1Ti0.9O3 ceramics fabricated using powders derived from oxalate precursor route
Authors: Bharathi P. , Varma K. B. R.
Published: October 2014

Fine powders comprising nanocrystallites of Ba0.85Ca0.15Zr0.1Ti0.9O3 (BCZT) were synthesized via oxalate precursor method, which facilitated to obtain homogenous and large grain sized ceramics at a lower sintering temperature. The compacted powders were sintered at various temperatures in the range of 1200 °C–1500 °C for an optimized duration of 10 h. Interestingly the one that was sintered at 1450 °C/10 h exhibited well resolved Morphotrophic Phase Boundary. The average grain size associated with this sample was 30 μm accompanied by higher domain density mostly with 90° twinning. These were believed to have significant contribution towards obtaining large strain of about 0.2% and piezoelectric coefficient as high as 563 pC/N. The maximum force that was generated by BCZT ceramic (having 30 μm grain size) was found to be 161 MPa, which is much higher than that of known actuator materials such as PZT (40 MPa) and NKN-5-LT (7 MPa).
Ab-initio study of donor-acceptor codoping for n-type CuO
Authors: Peng Yuan , Zheng Jianwei , Wu Ping , Wang Junling
Published: October 2014

Single n-type dopant in CuO has either a deep donor level or limited solubility, inefficient in generating free electrons. We have performed ab-initio study of the donor-acceptor codoping to obtain n-type CuO. Our results show that N codoping can slightly improve the donor level of Zr and In by forming shallower n-type complexes (ZrCu-NO and 2InCu-NO), but their formation energies are too high to be realized in experiments. However, Li codoping with Al and Ga is found to be relatively easy to achieve. 2AlCu-LiCu and 2GaCu-LiCu have shallower donor levels than single Al and Ga by 0.14 eV and 0.08 eV, respectively, and their formation energies are reasonably low to act as efficient codopants. Moreover, Li codoping with both Al and Ga produce an empty impurity band just below the host conduction band minimum, which may reduce the donor ionization energy at high codoping concentrations.
Magnetic interactions in CoCrPt-oxide based perpendicular magnetic recording media
Authors: Tan H. K. , Varghese B. , Piramanayagam S. N.
Published: October 2014

First order reversal curves (FORC) method has been reported to be an efficient tool to study interaction between grains and layers of magnetic materials. Although a few studies have been carried out on perpendicular recording media in the past, a study on the effect of systematic variation of exchange interaction in granular perpendicular magnetic recording media on FORC contours has not been carried out in detail. Such a study will help to understand the use of FORC better. In this paper, we have made a systematic set of samples in order to study the variation in exchange coupling and its effect on FORC contours. The pressure during the deposition of the second ruthenium layer and the magnetic layer was varied to alter the separation between the grains and hence the exchange interaction between the grains in the CoCrPt-oxide recording layer. In addition, the thickness of Co-alloy cap layer was used as an additional tool to control the exchange interaction between the magnetic grains. The results indicated that the interaction field obtained from the FORC does not vary in a significant manner when the changes in exchange interaction are small. In comparison, the peak intensity of the FORC shows a clear trend as the exchange coupling is varied, making it a more suitable parameter to study the exchange and magnetostatic interactions in systems such as magnetic recording media.
A feasibility study of in vivo applications of single beam acoustic tweezers
Authors: Li Ying , Lee Changyang , Chen Ruimin , Zhou Qifa , Shung K. Kirk
Published: October 2014

Tools that are capable of manipulating micro-sized objects have been widely used in such fields as physics, chemistry, biology, and medicine. Several devices, including optical tweezers, atomic force microscope, micro-pipette aspirator, and standing surface wave type acoustic tweezers have been studied to satisfy this need. However, none of them has been demonstrated to be suitable for in vivo and clinical studies. Single beam acoustic tweezers (SBAT) is a technology that uses highly focused acoustic beam to trap particles toward the beam focus. Its feasibility was first theoretically and experimentally demonstrated by Lee and Shung several years ago. Since then, much effort has been devoted to improving this technology. At present, the tool is capable of trapping a microparticle as small as 1 μm, as well as a single red blood cell. Although in comparing to other microparticles manipulating technologies, SBAT has advantages of providing stronger trapping force and deeper penetration depth in tissues, and producing less tissue damage, its potential for in vivo applications has yet been explored. It is worth noting that ultrasound has been used as a diagnostic tool for over 50 years and no known major adverse effects have been observed at the diagnostic energy level. This paper reports the results of an initial attempt to assess the feasibility of single beam acoustic tweezers to trap microparticles in vivo inside of a blood vessel. The acoustic intensity of SBAT under the trapping conditions that were utilized was measured. The mechanical index and thermal index at the focus of acoustic beam were found to be 0.48 and 0.044, respectively, which meet the standard of commercial diagnostic ultrasound system.
Fiber diameter control in electrospinning
Authors: Stepanyan R. , Subbotin A. , Cuperus L. , Boonen P. , Dorschu M. , Oosterlinck F. , Bulters M.
Published: October 2014

A simple model is proposed to predict the fiber diameter in electrospinning. We show that the terminal diameter is determined by the kinetics of the jet elongation—under the influence of the electric and viscous forces—and the solvent evaporation. Numerical and simple scaling analyses are performed, predicting the fiber diameter to scale as a power 1/3 of viscosity and 2/3 of polymer solution throughput divided by electrical current. Model predictions show a good agreement to our own electrospinning experiments on polyamide-6 solutions as well as to the data available in the literature.
Power and Contingency in Planning
Authors: Van Assche Kristof , Duineveld Martijn , Beunen Raoul
Published: October 2014

In this paper we analyse the role and reception of poststructuralist perspectives on power in planning since the 1990s, and then ask whether a renewed encounter with the works of poststructuralist theorists Foucault, Deleuze, and Luhmann could add something to the points that were already made. We make a distinction between the power of planning (the impact in society), power in planning (relations between players active in planning), and power on planning (the influence of broader society on the planning system), to refine the analysis of planning/power. It is argued that an interpretation of Deleuze, Luhmann, and Foucault, as thinkers of power in a theoretical framework that is based on the idea of contingency, can help to refine the analysis of power in planning. Planning then can be regarded as a system in other systems, with roles, values, procedures, and materialities in constant transformation, with the results of each operation serving as input for the next one. The different power relations constitute the possibilities, the forms, and the potential impact of planning.
Ideas, Interests, and Institutions: Explaining Dutch Transit-Oriented Development Challenges
Authors: Pojani Dorina , Stead Dominic
Published: October 2014

As a planning concept, transit-oriented development (TOD) has become popular in the Netherlands over the last few decades. However, the transition from planning concept to development practice has been fraught with difficulties. Where TOD projects have been implemented, they have often met with limited success in terms of livability and market viability. This paper examines TOD-related efforts in the Netherlands and the reasons for their difficulties up to now. The analysis is built around an analytical framework, which considers the role of ‘ideas’, ‘interests’, and ‘institutions’, as well as their interaction, in affecting the outcomes of these TOD efforts.
The Impact of Residential Location and Settlement Hierarchy on Ecological Footprint
Authors: Poom Age , Ahas Rein , Orru Kati
Published: October 2014

This study addresses the question of how residential location influences the ecological footprint (EF) of households. The type and location of settlements are considered one of the key determinants of the patterns of mobility and consumption, and their associated environmental load. As different settlement types bring different consumption intensities causing adverse environmental effects, the search for the best settlement structure is complicated. We study the environmental load of 16–17-year-old high school students from thirty randomly selected schools located across Estonia by means of a questionnaire survey. The study finds that the EF of high school students is significantly affected by the position of their residence in the settlement hierarchy as a result of different levels of affluence, density, and accessibility to goods and service, all of which vary spatially. Students from the metropolitan area of Tallinn tend to place a larger load on the environment and have higher EF values than students from the rest of Estonia. In addition, higher per capita income and larger living spaces tend to increase the footprint of these students. The results show that the strong sociospatial stratification of Estonian residents, symptomatic of a transitional society, is evident also in their environmental consumption load and mobility habits.
Everyday Expertise: Land Regularization and the Conditions for Land Grabs in Petén, Guatemala
Authors: Gould Kevin A
Published: October 2014

Advocates claim that market-assisted land reform (MALR) promotes economic development and reduces poverty by improving the security of private property rights and the efficiency of land markets. However, scholars argue that MALR often benefits elites at the expense of the disadvantaged and forces intended beneficiaries to resist or make difficult compromises. Nevertheless, this critical literature largely glosses everyday processes of implementation that help this policy get traction in particular locations. This paper examines the work of regularizing (titling) land in the context of a World-Bank-funded MALR project in northern Guatemala. Specifically, the focus is on the meaning-making work of field technicians who seek to convince campesinos (peasants) to participate in this regularization project. In their recruiting efforts, these technicians creatively link neoliberal slogans, human rights narratives, and exclusionary visions of nation, race, and property. By examining how technicians elaborate knowledge in the field and on the fly, this study reveals spheres of politics where regularization could be modestly contested or transformed. Such politics are worth attending to because in northern Guatemala and elsewhere, regularization contributes to conditions for land grabs.
A Mitofusin-2–dependent inactivating cleavage of Opa1 links changes in mitochondria
cristae
and ER contacts in the postprandial liver
Authors: Sood Aditi , Jeyaraju Danny Vijey , Prudent Julien , Caron Alexandre , Lemieux Philippe , McBride Heidi May , Laplante Mathieu , Tóth Katalin , Pellegrini Luca
Published: October 2014

Significance

We provide, to our knowledge, the first in vivo quantitative description of the adaptive response of the mitochondrial reticulum to the metabolic transition occurring in the liver in the hours after feeding. When nutrients become limiting, mitochondria size,
cristae
density, and respiratory capacity drop, but mitochondria–ER contacts, which control calcium and lipids fluxes between these organelles, double. A proteolytic inactivation of Optic atrophy 1 (Opa1), a major regulator of fusion and
cristae
architecture, accompanies these changes and found to depend on Mitofusin-2, a key regulator of mitochondria–ER contact biogenesis. Thus, mitochondria adapt to nutrient depletion by coupling the molecular machineries that organize
cristae
architecture and mitochondria–ER contact assembly, which were previously thought to operate independently of each other.