Assembling large, complex environmental metagenomes

Energy Technology Data Exchange (ETDEWEB)

Howe, A. C. [Michigan State Univ., East Lansing, MI (United States). Microbiology and Molecular Genetics, Plant Soil and Microbial Sciences; Jansson, J. [USDOE Joint Genome Institute (JGI), Walnut Creek, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Earth Sciences Division; Malfatti, S. A. [USDOE Joint Genome Institute (JGI), Walnut Creek, CA (United States); Tringe, S. G. [USDOE Joint Genome Institute (JGI), Walnut Creek, CA (United States); Tiedje, J. M. [Michigan State Univ., East Lansing, MI (United States). Microbiology and Molecular Genetics, Plant Soil and Microbial Sciences; Brown, C. T. [Michigan State Univ., East Lansing, MI (United States). Microbiology and Molecular Genetics, Computer Science and Engineering

2012-12-28

The large volumes of sequencing data required to sample complex environments deeply pose new challenges to sequence analysis approaches. De novo metagenomic assembly effectively reduces the total amount of data to be analyzed but requires significant computational resources. We apply two pre-assembly filtering approaches, digital normalization and partitioning, to make large metagenome assemblies more computationaly tractable. Using a human gut mock community dataset, we demonstrate that these methods result in assemblies nearly identical to assemblies from unprocessed data. We then assemble two large soil metagenomes from matched Iowa corn and native prairie soils. The predicted functional content and phylogenetic origin of the assembled contigs indicate significant taxonomic differences despite similar function. The assembly strategies presented are generic and can be extended to any metagenome; full source code is freely available under a BSD license.

Determining Complex Structures using Docking Method with Single Particle Scattering Data

Directory of Open Access Journals (Sweden)

Haiguang Liu

2017-04-01

Full Text Available Protein complexes are critical for many molecular functions. Due to intrinsic flexibility and dynamics of complexes, their structures are more difficult to determine using conventional experimental methods, in contrast to individual subunits. One of the major challenges is the crystallization of protein complexes. Using X-ray free electron lasers (XFELs, it is possible to collect scattering signals from non-crystalline protein complexes, but data interpretation is more difficult because of unknown orientations. Here, we propose a hybrid approach to determine protein complex structures by combining XFEL single particle scattering data with computational docking methods. Using simulations data, we demonstrate that a small set of single particle scattering data collected at random orientations can be used to distinguish the native complex structure from the decoys generated using docking algorithms. The results also indicate that a small set of single particle scattering data is superior to spherically averaged intensity profile in distinguishing complex structures. Given the fact that XFEL experimental data are difficult to acquire and at low abundance, this hybrid approach should find wide applications in data interpretations.

Large branched self-assembled DNA complexes

International Nuclear Information System (INIS)

Tosch, Paul; Waelti, Christoph; Middelberg, Anton P J; Davies, A Giles

2007-01-01

Many biological molecules have been demonstrated to self-assemble into complex structures and networks by using their very efficient and selective molecular recognition processes. The use of biological molecules as scaffolds for the construction of functional devices by self-assembling nanoscale complexes onto the scaffolds has recently attracted significant attention and many different applications in this field have emerged. In particular DNA, owing to its inherent sophisticated self-organization and molecular recognition properties, has served widely as a scaffold for various nanotechnological self-assembly applications, with metallic and semiconducting nanoparticles, proteins, macromolecular complexes, inter alia, being assembled onto designed DNA scaffolds. Such scaffolds may typically contain multiple branch-points and comprise a number of DNA molecules selfassembled into the desired configuration. Previously, several studies have used synthetic methods to produce the constituent DNA of the scaffolds, but this typically constrains the size of the complexes. For applications that require larger self-assembling DNA complexes, several tens of nanometers or more, other techniques need to be employed. In this article, we discuss a generic technique to generate large branched DNA macromolecular complexes

Single-molecule magnetism in a single-ion triamidoamine uranium(V) terminal mono-oxo complex

Energy Technology Data Exchange (ETDEWEB)

King, David M.; McMaster, Jonathan; Lewis, William; Blake, Alexander J.; Liddle, Stephen T. [School of Chemistry, University of Nottingham (United Kingdom); Tuna, Floriana; McInnes, Eric J.L. [School of Chemistry and Photon Science Institute, University of Manchester (United Kingdom)

2013-04-26

Straightforward oxidation of a triamidoamine uranium(III) complex with trimethyl-N-oxide affords a uranium(V) terminal mono-oxo complex which is the first clear-cut example of a uranium(V) single-molecule magnet (SMM). This monometallic complex unambiguously shows that a strongly axially ligated and thus anisotropic ligand field can be used to overcome the limited magnetic anisotropy of uranium(V). (Copyright copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Single-molecule magnetism in a single-ion triamidoamine uranium(V) terminal mono-oxo complex

International Nuclear Information System (INIS)

King, David M.; McMaster, Jonathan; Lewis, William; Blake, Alexander J.; Liddle, Stephen T.; Tuna, Floriana; McInnes, Eric J.L.

2013-01-01

Straightforward oxidation of a triamidoamine uranium(III) complex with trimethyl-N-oxide affords a uranium(V) terminal mono-oxo complex which is the first clear-cut example of a uranium(V) single-molecule magnet (SMM). This monometallic complex unambiguously shows that a strongly axially ligated and thus anisotropic ligand field can be used to overcome the limited magnetic anisotropy of uranium(V). (Copyright copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Single molecule magnet behaviour in robust dysprosium-biradical complexes.

Science.gov (United States)

Bernot, Kevin; Pointillart, Fabrice; Rosa, Patrick; Etienne, Mael; Sessoli, Roberta; Gatteschi, Dante

2010-09-21

A Dy-biradical complex was synthesized and characterized down to very low temperature. ac magnetic measurements reveal single molecule magnet behaviour visible without any application of dc field. The transition to the quantum tunneling regime is evidenced. Photophysical and EPR measurements provide evidence of the excellent stability of these complexes in solution.

Complex single gene disorders and epilepsy.

LENUS (Irish Health Repository)

Merwick, Aine

2012-09-01

Epilepsy is a heterogeneous group of disorders, often associated with significant comorbidity, such as intellectual disability and skin disorder. The genetic underpinnings of many epilepsies are still being elucidated, and we expect further advances over the coming 5 years, as genetic technology improves and prices fall for whole exome and whole genome sequencing. At present, there are several well-characterized complex epilepsies associated with single gene disorders; we review some of these here. They include well-recognized syndromes such as tuberous sclerosis complex, epilepsy associated with Rett syndrome, some of the progressive myoclonic epilepsies, and novel disorders such as epilepsy associated with mutations in the PCDH 19 gene. These disorders are important in informing genetic testing to confirm a diagnosis and to permit better understanding of the variability in phenotype-genotype correlation.

Large-scale computing techniques for complex system simulations

CERN Document Server

Dubitzky, Werner; Schott, Bernard

2012-01-01

Complex systems modeling and simulation approaches are being adopted in a growing number of sectors, including finance, economics, biology, astronomy, and many more. Technologies ranging from distributed computing to specialized hardware are explored and developed to address the computational requirements arising in complex systems simulations. The aim of this book is to present a representative overview of contemporary large-scale computing technologies in the context of complex systems simulations applications. The intention is to identify new research directions in this field and

Automated X-ray television complex for testing large dynamic objects

International Nuclear Information System (INIS)

Gusev, E.A.; Luk'yanenko, Eh.A.; Chelnokov, V.B.; Kuleshov, V.K.; Alkhimov, Yu.V.

1992-01-01

An automated X-ray television complex on the base of matrix gas-dischage large-area (2.1x1.0 m) converter for testing large cargoes and containers, as well as for inductrial article diagnostics is described. The complex pulsed operation with the 512 kbytes television digital memory unit provides for testing dynamic objects under minimal doses (20-100 μR)

Pilot Study of Topical Copper Chlorophyllin Complex in Subjects With Facial Acne and Large Pores.

Science.gov (United States)

Stephens, Thomas J; McCook, John P; Herndon, James H

2015-06-01

Acne vulgaris is one of the most common skin diseases treated by dermatologists. Salts of copper chlorophyllin complex are semi-synthetic naturally-derived compounds with antioxidant, anti-inflammatory and wound healing activity that have not been previously tested topically in the treatment of acne-prone skin with enlarged pores. This single-center pilot study was conducted to assess the efficacy and safety of a liposomal dispersion of topically applied sodium copper chlorophyllin complex in subjects with mild-moderate acne and large, visible pores over a course of 3 weeks. Subjects were supplied with the test product, a topical gel containing a liposomal dispersion of sodium copper chlorophyllin complex (0.1%) with directions to apply a small amount to the facial area twice daily. Clinical assessments were performed at screening/baseline and at week 3. VISIA readings were taken and self-assessment questionnaires were conducted. 10 subjects were enrolled and completed the 3-week study. All clinical efficacy parameters showed statistically significant improvements over baseline at week 3. The study product was well tolerated. Subject questionnaires showed the test product was highly rated. In this pilot study, a topical formulation containing a liposomal dispersion of sodium copper chlorophyllin complex was shown to be clinically effective and well tolerated for the treatment of mild-moderate acne and large, visible pores when used for 3 weeks.

White OLED with a single-component europium complex.

Science.gov (United States)

Law, Ga-Lai; Wong, Ka-Leung; Tam, Hoi-Lam; Cheah, Kok-Wai; Wong, Wing-Tak

2009-11-16

A new direction for white organic light-emitting devices is shown, fabricated from a novel europium complex; this single component contains a double emission center of bluish-green and red, combined to a give a pure white emission (CIE x = 0.34 and y = 0.35).

Control protocol: large scale implementation at the CERN PS complex - a first assessment

International Nuclear Information System (INIS)

Abie, H.; Benincasa, G.; Coudert, G.; Davydenko, Y.; Dehavay, C.; Gavaggio, R.; Gelato, G.; Heinze, W.; Legras, M.; Lustig, H.; Merard, L.; Pearson, T.; Strubin, P.; Tedesco, J.

1994-01-01

The Control Protocol is a model-based, uniform access procedure from a control system to accelerator equipment. It was proposed at CERN about 5 years ago and prototypes were developed in the following years. More recently, this procedure has been finalized and implemented at a large scale in the PS Complex. More than 300 pieces of equipment are now using this protocol in normal operation and another 300 are under implementation. These include power converters, vacuum systems, beam instrumentation devices, RF equipment, etc. This paper describes how the single general procedure is applied to the different kinds of equipment. The advantages obtained are also discussed. ((orig.))

Management of Large Erupting Complex Odontoma in Maxilla

Directory of Open Access Journals (Sweden)

Colm Murphy

2014-01-01

Full Text Available We present the unusual case of a large complex odontoma erupting in the maxilla. Odontomas are benign developmental tumours of odontogenic origin. They are characterized by slow growth and nonaggressive behaviour. Complex odontomas, which erupt, are rare. They are usually asymptomatic and are identified on routine radiograph but may present with erosion into the oral cavity with subsequent cellulitis and facial asymmetry. This present paper describes the presentation and management of an erupting complex odontoma, occupying the maxillary sinus with extension to the infraorbital rim. We also discuss various surgical approaches used to access this anatomic area.

Large single-crystal diamond substrates for ionizing radiation detection

Energy Technology Data Exchange (ETDEWEB)

Girolami, Marco; Bellucci, Alessandro; Calvani, Paolo; Trucchi, Daniele M. [Istituto di Struttura della Materia (ISM), Consiglio Nazionale delle Ricerche (CNR), Sede Secondaria di Montelibretti, Monterotondo Stazione, Roma (Italy)

2016-10-15

The need for large active volume detectors for ionizing radiations and particles, with both large area and thickness, is becoming more and more compelling in a wide range of applications, spanning from X-ray dosimetry to neutron spectroscopy. Recently, 8.0 x 8.0 mm{sup 2} wide and 1.2 mm thick single-crystal diamond plates have been put on the market, representing a first step to the fabrication of large area monolithic diamond detectors with optimized charge transport properties, obtainable up to now only with smaller samples. The more-than-double thickness, if compared to standard plates (typically 500 μm thick), demonstrated to be effective in improving the detector response to highly penetrating ionizing radiations, such as γ-rays. Here we report on the first measurements performed on large active volume single-crystal diamond plates, both in the dark and under irradiation with optical wavelengths (190-1100 nm), X-rays, and radioactive γ-emitting sources ({sup 57}Co and {sup 22}Na). (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Recent progress in large grain/single crystal high RRR niobium

International Nuclear Information System (INIS)

Ganapati Rao Myneni; Peter Kneisel; Tadeu Carneiro; S.R. Agnew; F. Stevie

2005-01-01

High RRR bulk niobium Superconducting Radio Frequency (SRF) cavity technology is chosen for the International Linear Collider (ILC). The SRF community was convinced until now that fine grain polycrystalline RRR niobium sheets obtained via forging and cross rolling are essential for forming the SRF Cavities. However, it was recently discovered under a joint Reference Metals Company, Inc., - JLAB CRADA that large grain/single crystal RRR niobium sliced directly from ingots is highly ductile reaching 100 percent elongation. This discovery led to the successful fabrication of several SRF single and/or multi cell structures, formed with sliced RRR discs from the ingots, operating at 2.3, 1.5 and 1.3 GHz. This new exciting development is expected to offer high performance accelerator structures not only at reduced costs but also with simpler fabrication and processing conditions. As a result there is a renewed interest in the evaluation and understanding of the large grain and single crystal niobium with respect to their mechanical and physical properties as well as the oxidation behavior and the influence of impurities such as hydrogen and Ta. In this paper the results of many collaborative studies on large grain and single crystal high RRR niobium between JLAB, Universities and Industry are presented

Single-molecule magnetism in a single-ion triamidoamine uranium(V) terminal mono-oxo complex

Energy Technology Data Exchange (ETDEWEB)

King, David M.; McMaster, Jonathan; Lewis, William; Blake, Alexander J.; Liddle, Stephen T. [Nottingham Univ. (United Kingdom). School of Chemistry; Tuna, Floriana; McInnes, Eric J.L. [Manchester Univ. (United Kingdom). School of Chemistry

2013-04-26

Straightforward oxidation of a triamidoamine uranium(III) complex with trimethyl-N-oxide affords a uranium(V) terminal mono-oxo complex which is the first clear-cut example of a uranium(V) single-molecule magnet (SMM). This monometallic complex unambiguously shows that a strongly axially ligated and thus anisotropic ligand field can be used to overcome the limited magnetic anisotropy of uranium(V). [German] Die direkte Oxidation eines Triamidoamin-Uran(III)-Komplexes mit Trimethyl-N-oxid liefert einen terminalen Uran(V)-Mono(oxo)komplex, der das erste gesicherte Beispiel eines Uran(V)-Einzelmolekuelmagnets ist. Dieser monometallische Komplex zeigt eindeutig, dass ein starkes axiales und somit anisotropes Ligandenfeld die begrenzte magnetische Anisotropie von Uran(V) beseitigen kann.

Low-Temperature and Rapid Growth of Large Single-Crystalline Graphene with Ethane.

Science.gov (United States)

Sun, Xiao; Lin, Li; Sun, Luzhao; Zhang, Jincan; Rui, Dingran; Li, Jiayu; Wang, Mingzhan; Tan, Congwei; Kang, Ning; Wei, Di; Xu, H Q; Peng, Hailin; Liu, Zhongfan

2018-01-01

Future applications of graphene rely highly on the production of large-area high-quality graphene, especially large single-crystalline graphene, due to the reduction of defects caused by grain boundaries. However, current large single-crystalline graphene growing methodologies are suffering from low growth rate and as a result, industrial graphene production is always confronted by high energy consumption, which is primarily caused by high growth temperature and long growth time. Herein, a new growth condition achieved via ethane being the carbon feedstock to achieve low-temperature yet rapid growth of large single-crystalline graphene is reported. Ethane condition gives a growth rate about four times faster than methane, achieving about 420 µm min -1 for the growth of sub-centimeter graphene single crystals at temperature about 1000 °C. In addition, the temperature threshold to obtain graphene using ethane can be reduced to 750 °C, lower than the general growth temperature threshold (about 1000 °C) with methane on copper foil. Meanwhile ethane always keeps higher graphene growth rate than methane under the same growth temperature. This study demonstrates that ethane is indeed a potential carbon source for efficient growth of large single-crystalline graphene, thus paves the way for graphene in high-end electronical and optoelectronical applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Single stage reconstruction of complex anterior urethral strictures

Directory of Open Access Journals (Sweden)

Deepak Dubey

2001-01-01

Full Text Available Purpose: Single stage reconstruction of long, com-plex urethral strictures is technically demanding and may require the use of more than one tissue transfer technique. We describe our experience in the manage-ment of such strictures with a variety of urethroplasty techniques. Materials and Methods: Between 1989 and 1999, 25 men (mean age 38.5 years underwent single stage re-construction of panurethral, multiple segment or focally dense strictures [mean length 11.2 cm (range 8-17 cm]. 8 patients had combined substitution urethroplasty with a circumpenile fasciocutaneous flap and a free graft of bladder/buccal mucosa or tunica vaginalis . flap. In 10 patients a single tissue transfer technique was used. 3 patients underwent an augmented roof/floor strip ure-throplasty with a penile skin flap. 4 patients with multi-ple segment strictures (separate pendulous and bulbar underwent distal onlay flap and proximal anastomotic urethroplasty. Results: The median ,follow-up was 46.5 months (range 6-88 months. The mean postoperative flow rate improved to 22.5 ml/sec. 2 patients developed fistulae requiring repair. Recurrent stricture developed in 5 (20.8% patients, of which 2 were managed with visual internal urethrotomy, 2 with anastomotic urethroplasty and 1 with a two-stage procedure. Pseudodiverticulum and post-void dribbling were seen in 6 (25% patients. Conclusions: Successful outcome of single stage re-construction of long complex strictures can be achieved with a combination of various tissue transfer methods. The urologist who has a thorough knowledge of penile skin and urethral vascular anatomy and a wide array of substitution techniques in his armamentarium can un-dertake approach to such strictures.

Complex Pattern Formation from Current-Driven Dynamics of Single-Layer Homoepitaxial Islands on Crystalline Conducting Substrates

Science.gov (United States)

Kumar, Ashish; Dasgupta, Dwaipayan; Maroudas, Dimitrios

2017-07-01

We report a systematic study of complex pattern formation resulting from the driven dynamics of single-layer homoepitaxial islands on surfaces of face-centered-cubic (fcc) crystalline conducting substrates under the action of an externally applied electric field. The analysis is based on an experimentally validated nonlinear model of mass transport via island edge atomic diffusion, which also accounts for edge diffusional anisotropy. We analyze the morphological stability and simulate the field-driven evolution of rounded islands for an electric field oriented along the fast edge diffusion direction. For larger-than-critical island sizes on {110 } and {100 } fcc substrates, we show that multiple necking instabilities generate complex island patterns, including not-simply-connected void-containing islands mediated by sequences of breakup and coalescence events and distributed symmetrically with respect to the electric field direction. We analyze the dependence of the formed patterns on the original island size and on the duration of application of the external field. Starting from a single large rounded island, we characterize the evolution of the number of daughter islands and their average size and uniformity. The evolution of the average island size follows a universal power-law scaling relation, and the evolution of the total edge length of the islands in the complex pattern follows Kolmogorov-Johnson-Mehl-Avrami kinetics. Our study makes a strong case for the use of electric fields, as precisely controlled macroscopic forcing, toward surface patterning involving complex nanoscale features.

Single photon emission computed tomography in AIDS dementia complex

International Nuclear Information System (INIS)

Pohl, P.; Vogl, G.; Fill, H.; Roessler, H.Z.; Zangerle, R.; Gerstenbrand, F.

1988-01-01

Single photon emission computed tomography (SPECT) studies were performed in AIDS dementia complex using IMP in 12 patients (and HM-PAO in four of these same patients). In all patients, SPECT revealed either multiple or focal uptake defects, the latter corresponding with focal signs or symptoms in all but one case. Computerized tomography showed a diffuse cerebral atrophy in eight of 12 patients, magnetic resonance imaging exhibited changes like atrophy and/or leukoencephalopathy in two of five cases. Our data indicate that both disturbance of cerebral amine metabolism and alteration of local perfusion share in the pathogenesis of AIDS dementia complex. SPECT is an important aid in the diagnosis of AIDS dementia complex and contributes to the understanding of the pathophysiological mechanisms of this disorder

Single Molecule Spectroscopy on Photosynthetic Pigment-Protein Complexes

CERN Document Server

Jelezko, F; Schuler, S; Thews, E; Tietz, C; Wechsler, A; Wrachtrup, J

2001-01-01

Single molecule spectroscopy was applied to unravel the energy transfer pathway in photosynthetic pigment-protein complexes. Detailed analysis of excitation and fluorescence emission spectra has been made for peripheral plant antenna LHC II and Photosystem I from cyanobacterium Synechococcus elongatus. Optical transitions of individual pigments were resolved under nonselective excitation of antenna chlorophylls. High-resolution fluorescence spectroscopy of individual plant antenna LHC II indicates that at low temperatures, the excitation energy is localized on the red-most Chl a pool absorbing at 680 nm. More than one pigment molecule is responsible for the fluorescence emission of the LHC II trimer. The spectral lines of single Chl a molecules absorbing at 675 nm are broadened because of the Foerster energy transfer towards the red-most pigments. Low-temperature spectroscopy on single PS I trimers indicates that two subgroups of pigments, which are present in the red antenna pool, differ by the strength of t...

Protein dynamics revealed in the excitonic spectra of single LH2 complexes

International Nuclear Information System (INIS)

Valkunas, Leonas; Janusonis, Julius; Rutkauskas, Danielis; Grondelle, Rienk van

2007-01-01

The fluorescence emission spectrum of single peripheral light-harvesting (LH2) complexes of the photosynthetic purple bacterium Rhodopseudomonas acidophila exhibits remarkable dynamics on a time scale of several minutes. Often the spectral properties are quasi-stable; sometimes large spectral jumps to the blue or to the red are observed. To explain the dynamics, every pigment is proposed to be in two conformational substates with different excitation energies, which originate from the conformational state of the protein as a result of pigment-protein interaction. Due to the excitonic coupling in the ring of 18 pigments, the two-state assumption generates a substantial amount of distinct spectroscopic states, which reflect part of the inhomogeneous distributed spectral properties of LH2. To describe the observed dynamics, spontaneous and light-induced transitions are introduced between the two states. For each 'realization of the disorder', the spectral properties are calculated using a disordered exciton model combined with the modified Redfield theory to obtain realistic spectral line shapes. The single-molecule fluorescence peak (FLP) distribution, the distribution dependence on the excitation intensity, and the FLP time traces are well described within the framework of this model

Defining Execution Viewpoints for a Large and Complex Software-Intensive System

OpenAIRE

Callo Arias, Trosky B.; America, Pierre; Avgeriou, Paris

2009-01-01

An execution view is an important asset for developing large and complex systems. An execution view helps practitioners to describe, analyze, and communicate what a software system does at runtime and how it does it. In this paper, we present an approach to define execution viewpoints for an existing large and complex software-intensive system. This definition approach enables the customization and extension of a set of predefined viewpoints to address the requirements of a specific developme...

Role of optometry school in single day large scale school vision testing

Science.gov (United States)

Anuradha, N; Ramani, Krishnakumar

2015-01-01

Background: School vision testing aims at identification and management of refractive errors. Large-scale school vision testing using conventional methods is time-consuming and demands a lot of chair time from the eye care professionals. A new strategy involving a school of optometry in single day large scale school vision testing is discussed. Aim: The aim was to describe a new approach of performing vision testing of school children on a large scale in a single day. Materials and Methods: A single day vision testing strategy was implemented wherein 123 members (20 teams comprising optometry students and headed by optometrists) conducted vision testing for children in 51 schools. School vision testing included basic vision screening, refraction, frame measurements, frame choice and referrals for other ocular problems. Results: A total of 12448 children were screened, among whom 420 (3.37%) were identified to have refractive errors. 28 (1.26%) children belonged to the primary, 163 to middle (9.80%), 129 (4.67%) to secondary and 100 (1.73%) to the higher secondary levels of education respectively. 265 (2.12%) children were referred for further evaluation. Conclusion: Single day large scale school vision testing can be adopted by schools of optometry to reach a higher number of children within a short span. PMID:25709271

A Single-Cell Biochemistry Approach Reveals PAR Complex Dynamics during Cell Polarization.

Science.gov (United States)

Dickinson, Daniel J; Schwager, Francoise; Pintard, Lionel; Gotta, Monica; Goldstein, Bob

2017-08-21

Regulated protein-protein interactions are critical for cell signaling, differentiation, and development. For the study of dynamic regulation of protein interactions in vivo, there is a need for techniques that can yield time-resolved information and probe multiple protein binding partners simultaneously, using small amounts of starting material. Here we describe a single-cell protein interaction assay. Single-cell lysates are generated at defined time points and analyzed using single-molecule pull-down, yielding information about dynamic protein complex regulation in vivo. We established the utility of this approach by studying PAR polarity proteins, which mediate polarization of many animal cell types. We uncovered striking regulation of PAR complex composition and stoichiometry during Caenorhabditis elegans zygote polarization, which takes place in less than 20 min. PAR complex dynamics are linked to the cell cycle by Polo-like kinase 1 and govern the movement of PAR proteins to establish polarity. Our results demonstrate an approach to study dynamic biochemical events in vivo. Copyright © 2017 Elsevier Inc. All rights reserved.

Multi-kW single fiber laser based on an extra large mode area fiber design

Science.gov (United States)

Langner, Andreas; Such, Mario; Schötz, Gerhard; Just, Florian; Leich, Martin; Schwuchow, Anka; Grimm, Stephan; Zimer, Hagen; Kozak, Marcin; Wedel, Björn; Rehmann, Georg; Bachert, Charley; Krause, Volker

2012-02-01

The quality of Yb-doped fused bulk silica produced by sintering of Yb-doped fused silica granulates has improved greatly in the past five years [1 - 4]. In particular, the refractive index and doping level homogeneity of such materials are excellent and we achieved excellent background fiber attenuation of the active core material down to about 20 dB/km at 1200 nm. The improvement of the Yb-doped fused bulk silica has enabled the development of multi-kW fiber laser systems based on a single extra large multimode laser fiber (XLMA fiber). When a single active fiber is used in combination with the XLMA multimode fiber of 1200 μm diameter simple and robust high power fiber laser setups without complex fiber coupling and fiber combiner systems become possible. In this papper, we will discuss in detail the development of the core material based on Yb-doped bulk silica and the characterization of Yb-doped fibers with different core compositions. We will also report on the excellent performance of a 4 kW fiber laser based on a single XLMA-fiber and show the first experimental welding results of steel sheets achieved with such a laser.

Assembly and control of large microtubule complexes

Science.gov (United States)

Korolev, Kirill; Ishihara, Keisuke; Mitchison, Timothy

Motility, division, and other cellular processes require rapid assembly and disassembly of microtubule structures. We report a new mechanism for the formation of asters, radial microtubule complexes found in very large cells. The standard model of aster growth assumes elongation of a fixed number of microtubules originating from the centrosomes. However, aster morphology in this model does not scale with cell size, and we found evidence for microtubule nucleation away from centrosomes. By combining polymerization dynamics and auto-catalytic nucleation of microtubules, we developed a new biophysical model of aster growth. The model predicts an explosive transition from an aster with a steady-state radius to one that expands as a travelling wave. At the transition, microtubule density increases continuously, but aster growth rate discontinuously jumps to a nonzero value. We tested our model with biochemical perturbations in egg extract and confirmed main theoretical predictions including the jump in the growth rate. Our results show that asters can grow even though individual microtubules are short and unstable. The dynamic balance between microtubule collapse and nucleation could be a general framework for the assembly and control of large microtubule complexes. NIH GM39565; Simons Foundation 409704; Honjo International 486 Scholarship Foundation.

Fluorescence spectroscopy of conformational changes of single LH2 complexes

NARCIS (Netherlands)

Rutkauskas, D.; Novoderezhkin, V.; Cogdell, R.J.; van Grondelle, R.

2005-01-01

We have investigated the energy landscape of the bacterial photosynthetic peripheral light-harvesting complex LH2 of purple bacterium Rhodopseudomonas acidophila by monitoring sequences of fluorescence spectra of single LH2 assemblies, at room temperature, with different excitation intensities as

Ideas for future large single dish radio telescopes

Science.gov (United States)

Kärcher, Hans J.; Baars, Jacob W. M.

2014-07-01

The existing large single dish radio telescopes of the 100m class (Effelsberg, Green Bank) were built in the 1970s and 1990s. With some active optics they work now down to 3 millimeter wavelength where the atmospheric quality of the site is also a limiting factor. Other smaller single dish telescopes (50m LMT Mexico, 30m IRAM Spain) are located higher and reach sub-millimeter quality, and the much smaller 12m antennas of the ALMA array reach at a very high site the Terahertz region. They use advanced technologies as carbon fiber structures and flexible body control. We review natural limits to telescope design and use the examples of a number of telescopes for an overview of the available state-of-the-art in design, engineering and technologies. Without considering the scientific justification we then offer suggestions to realize ultimate performance of huge single dish telescopes (up to 160m). We provide an outlook on design options, technological frontiers and cost estimates.

Processing of complex shapes with single-mode resonant frequency microwave applicators

International Nuclear Information System (INIS)

Fellows, L.A.; Delgado, R.; Hawley, M.C.

1994-01-01

Microwave processing is an alternative to conventional composite processing techniques. Single-mode microwave applicators efficiently couple microwave energy into the composite. The application of the microwave energy is greatly affected by the geometry of the composite. In the single mode microwave applicator, two types of modes are available. These modes are best suited to processing flat planar samples or cylindrical samples with geometries that align with the electric fields. Mode-switching is alternating between different electromagnetic modes with the intelligent selection of the modes to alleviate undesirable temperature profiles. This method has improved the microwave heating profiles of materials with complex shapes that do not align with either type of electric field. Parts with two different complex geometries were fabricated from a vinyl toluene/vinyl ester resin with a continuous glass fiber reinforcement by autoclaving and by microwave techniques. The flexural properties of the microwave processed samples were compared to the flexural properties of autoclaved samples. The trends of the mechanical properties for the complex shapes were consistent with the results of experiments with flat panels. This demonstrated that mode-switching techniques are as applicable for the complex shapes as they are for the simpler flat panel geometry

Low-Complexity Transmit Antenna Selection and Beamforming for Large-Scale MIMO Communications

Directory of Open Access Journals (Sweden)

Kun Qian

2014-01-01

Full Text Available Transmit antenna selection plays an important role in large-scale multiple-input multiple-output (MIMO communications, but optimal large-scale MIMO antenna selection is a technical challenge. Exhaustive search is often employed in antenna selection, but it cannot be efficiently implemented in large-scale MIMO communication systems due to its prohibitive high computation complexity. This paper proposes a low-complexity interactive multiple-parameter optimization method for joint transmit antenna selection and beamforming in large-scale MIMO communication systems. The objective is to jointly maximize the channel outrage capacity and signal-to-noise (SNR performance and minimize the mean square error in transmit antenna selection and minimum variance distortionless response (MVDR beamforming without exhaustive search. The effectiveness of all the proposed methods is verified by extensive simulation results. It is shown that the required antenna selection processing time of the proposed method does not increase along with the increase of selected antennas, but the computation complexity of conventional exhaustive search method will significantly increase when large-scale antennas are employed in the system. This is particularly useful in antenna selection for large-scale MIMO communication systems.

Risk Management and Uncertainty in Large Complex Public Projects

DEFF Research Database (Denmark)

Neerup Themsen, Tim; Harty, Chris; Tryggestad, Kjell

Governmental actors worldwide are promoting risk management as a rational approach to man-age uncertainty and improve the abilities to deliver large complex projects according to budget, time plans, and pre-set project specifications: But what do we know about the effects of risk management...... on the abilities to meet such objectives? Using Callon’s (1998) twin notions of framing and overflowing we examine the implementation of risk management within the Dan-ish public sector and the effects this generated for the management of two large complex pro-jects. We show how the rational framing of risk...... management have generated unexpected costly outcomes such as: the undermining of the longer-term value and societal relevance of the built asset, the negligence of the wider range of uncertainties emerging during project processes, and constraining forms of knowledge. We also show how expert accountants play...

Probing Single Pt Atoms in Complex Intermetallic Al13Fe4.

Science.gov (United States)

Yamada, Tsunetomo; Kojima, Takayuki; Abe, Eiji; Kameoka, Satoshi; Murakami, Yumi; Gille, Peter; Tsai, An Pang

2018-03-21

The atomic structure of a 0.2 atom % Pt-doped complex metallic alloy, monoclinic Al 13 Fe 4 , was investigated using a single crystal prepared by the Czochralski method. High-angle annular dark-field scanning transmission electron microscopy showed that the Pt atoms were dispersed as single atoms and substituted at Fe sites in Al 13 Fe 4 . Single-crystal X-ray structural analysis revealed that the Pt atoms preferentially substitute at Fe(1). Unlike those that have been reported, Pt single atoms in the surface layers showed lower activity and selectivity than those of Al 2 Pt and bulk Pt for propyne hydrogenation, indicating that the active state of a given single-atom Pt site is strongly dominated by the bonding to surrounding Al atoms.

Single-molecule spectroscopy reveals photosynthetic LH2 complexes switch between emissive states.

Science.gov (United States)

Schlau-Cohen, Gabriela S; Wang, Quan; Southall, June; Cogdell, Richard J; Moerner, W E

2013-07-02

Photosynthetic organisms flourish under low light intensities by converting photoenergy to chemical energy with near unity quantum efficiency and under high light intensities by safely dissipating excess photoenergy and deleterious photoproducts. The molecular mechanisms balancing these two functions remain incompletely described. One critical barrier to characterizing the mechanisms responsible for these processes is that they occur within proteins whose excited-state properties vary drastically among individual proteins and even within a single protein over time. In ensemble measurements, these excited-state properties appear only as the average value. To overcome this averaging, we investigate the purple bacterial antenna protein light harvesting complex 2 (LH2) from Rhodopseudomonas acidophila at the single-protein level. We use a room-temperature, single-molecule technique, the anti-Brownian electrokinetic trap, to study LH2 in a solution-phase (nonperturbative) environment. By performing simultaneous measurements of fluorescence intensity, lifetime, and spectra of single LH2 complexes, we identify three distinct states and observe transitions occurring among them on a timescale of seconds. Our results reveal that LH2 complexes undergo photoactivated switching to a quenched state, likely by a conformational change, and thermally revert to the ground state. This is a previously unobserved, reversible quenching pathway, and is one mechanism through which photosynthetic organisms can adapt to changes in light intensities.

Large complex ovarian cyst managed by laparoscopy

OpenAIRE

Dipak J. Limbachiya; Ankit Chaudhari; Grishma P. Agrawal

2017-01-01

Complex ovarian cyst with secondary infection is a rare disease that hardly responds to the usual antibiotic treatment. Most of the times, it hampers day to day activities of women. It is commonly known to cause pain and fever. To our surprise, in our case the cyst was large enough to compress the ureter and it was adherent to the surrounding structures. Laparoscopic removal of the cyst was done and specimen was sent for histopathological examination.

Value of spatial planning for large mining and energy complexes. [Yugoslavia

Energy Technology Data Exchange (ETDEWEB)

Matko, Z; Spasic, N

1982-01-01

In the example of the Kosovo complex (Socialist Federated Republic of Yugoslovia) an examination is made of the value of developing a spatial plan for the territory of large mining-energy complexes. The goals and expected results of spatial planning are discussed. The open method of working lignite, fuel shale and other fossil energy raw material fields at the modern level of development of technology, in addition to large-volume physical interferences in space, causes considerable structural changes of functional-economic, socioeconomic and psychological-sociological nature in the direct zone of influence of the mining-energy complex. Improvement in technology of working a lignite field does not guarantee in the near future any solutions in developing the mining-energy complexes, and therefore it is necessary to count on considerable volume of degradation of space which is governed by the existing technology. Under these conditions detailed planning and regulation of space is especially important, if one views them as a component part of long term policy for development of the mining energy complex and the zones of its influence.

Large rotating magnetocaloric effect in ErAlO3 single crystal

Directory of Open Access Journals (Sweden)

X. Q. Zhang

2017-05-01

Full Text Available Magnetic and magnetocaloric properties of ErAlO3 single crystal were investigated. Magnetization of ErAlO3 shows obvious anisotropy when magnetic field is applied along the a, b and c axes, which leads to large anisotropic magnetic entropy change. In particular, large rotating field entropy change from the b to c axis within the bc plane is obtained and reaches 9.7 J/kg K at 14 K in a field of 5 T. This suggests the possibility of using ErAlO3 single crystal for magnetic refrigerators by rotating its magnetization vector rather than moving it in and out of the magnet.

Organizational Influences on Interdisciplinary Interactions during Research and Design of Large-Scale Complex Engineered Systems

Science.gov (United States)

McGowan, Anna-Maria R.; Seifert, Colleen M.; Papalambros, Panos Y.

2012-01-01

The design of large-scale complex engineered systems (LaCES) such as an aircraft is inherently interdisciplinary. Multiple engineering disciplines, drawing from a team of hundreds to thousands of engineers and scientists, are woven together throughout the research, development, and systems engineering processes to realize one system. Though research and development (R&D) is typically focused in single disciplines, the interdependencies involved in LaCES require interdisciplinary R&D efforts. This study investigates the interdisciplinary interactions that take place during the R&D and early conceptual design phases in the design of LaCES. Our theoretical framework is informed by both engineering practices and social science research on complex organizations. This paper provides preliminary perspective on some of the organizational influences on interdisciplinary interactions based on organization theory (specifically sensemaking), data from a survey of LaCES experts, and the authors experience in the research and design. The analysis reveals couplings between the engineered system and the organization that creates it. Survey respondents noted the importance of interdisciplinary interactions and their significant benefit to the engineered system, such as innovation and problem mitigation. Substantial obstacles to interdisciplinarity are uncovered beyond engineering that include communication and organizational challenges. Addressing these challenges may ultimately foster greater efficiencies in the design and development of LaCES and improved system performance by assisting with the collective integration of interdependent knowledge bases early in the R&D effort. This research suggests that organizational and human dynamics heavily influence and even constrain the engineering effort for large-scale complex systems.

Complex mineralization at large ore deposits in the Russian Far East

Science.gov (United States)

Schneider, A. A.; Malyshev, Yu. F.; Goroshko, M. V.; Romanovsky, N. P.

2011-04-01

Genetic and mineralogical features of large deposits with complex Sn, W, and Mo mineralization in the Sikhote-Alin and Amur-Khingan metallogenic provinces are considered, as well as those of raremetal, rare earth, and uranium deposits in the Aldan-Stanovoi province. The spatiotemporal, geological, and mineralogical attributes of large deposits are set forth, and their geodynamic settings are determined. These attributes are exemplified in the large Tigriny Sn-W greisen-type deposit. The variation of regional tectonic settings and their spatial superposition are the main factor controlling formation of large deposits. Such a variation gives rise to multiple reactivation of the ore-magmatic system and long-term, multistage formation of deposits. Pulsatory mineralogical zoning with telescoped mineral assemblages related to different stages results in the formation of complex ores. The highest-grade zones of mass discharge of hydrothermal solutions are formed at the deposits. The promising greisen-type mineralization with complex Sn-W-Mo ore is suggested to be an additional source of tungsten and molybdenum. The Tigriny, Pravourminsky, and Arsen'evsky deposits, as well as deposits of the Komsomol'sk and Khingan-Olonoi ore districts are examples. Large and superlarge U, Ta, Nb, Be, and REE deposits are localized in the southeastern Aldan-Stanovoi Shield. The Ulkan and Arbarastakh ore districts attract special attention. The confirmed prospects of new large deposits with Sn, W, Mo, Ta, Nb, Be, REE, and U mineralization in the south of the Russian Far East assure expediency of further geological exploration in this territory.

Large-scale membrane transfer process: its application to single-crystal-silicon continuous membrane deformable mirror

International Nuclear Information System (INIS)

Wu, Tong; Sasaki, Takashi; Hane, Kazuhiro; Akiyama, Masayuki

2013-01-01

This paper describes a large-scale membrane transfer process developed for the construction of large-scale membrane devices via the transfer of continuous single-crystal-silicon membranes from one substrate to another. This technique is applied for fabricating a large stroke deformable mirror. A bimorph spring array is used to generate a large air gap between the mirror membrane and the electrode. A 1.9 mm × 1.9 mm × 2 µm single-crystal-silicon membrane is successfully transferred to the electrode substrate by Au–Si eutectic bonding and the subsequent all-dry release process. This process provides an effective approach for transferring a free-standing large continuous single-crystal-silicon to a flexible suspension spring array with a large air gap. (paper)

Complex Pattern Formation from Current-Driven Dynamics of Single-Layer Epitaxial Islands on Crystalline Conducting Substrates

Science.gov (United States)

Kumar, Ashish; Dasgupta, Dwaipayan; Maroudas, Dimitrios

We report a systematic study of complex pattern formation resulting from the driven dynamics of single-layer homoepitaxial islands on face-centered cubic (FCC) crystalline conducting substrate surfaces under the action of an externally applied electric field. The analysis is based on an experimentally validated nonlinear model of mass transport via island edge atomic diffusion, which also accounts for edge diffusional anisotropy. We analyze the morphological stability and simulate the field-driven evolution of rounded islands for an electric field oriented along the fast diffusion direction. For larger than critical island sizes on {110} and {100} FCC substrates, we show that multiple necking instabilities generate complex island patterns, including void-containing islands, mediated by sequences of breakup and coalescence events and distributed symmetrically with respect to the electric field direction. We analyze the dependence of the formed patterns on the original island size and on the duration of application of the external field. Starting from a single large rounded island, we characterize the evolution of the number of daughter islands and their average size and uniformity. The analysis reveals that the pattern formation kinetics follows a universal scaling relation. Division of Materials Sciences & Engineering, Office of Basic Energy Sciences, U.S. Department of Energy (Award No.: DE-FG02-07ER46407).

Energy transfer from natural photosynthetic complexes to single-wall carbon nanotubes

Energy Technology Data Exchange (ETDEWEB)

Wiwatowski, Kamil [Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Grudziadzka 5, 87-100 Torun (Poland); Dużyńska, Anna; Świniarski, Michał [Faculty of Physics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw (Poland); Szalkowski, Marcin [Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Grudziadzka 5, 87-100 Torun (Poland); Zdrojek, Mariusz; Judek, Jarosław [Faculty of Physics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw (Poland); Mackowski, Sebastian, E-mail: mackowski@fizyka.umk.pl [Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Grudziadzka 5, 87-100 Torun (Poland); Wroclaw Research Center EIT+, Stablowicka 147, Wroclaw (Poland); Kaminska, Izabela [Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Grudziadzka 5, 87-100 Torun (Poland)

2016-02-15

Combination of fluorescence imaging and spectroscopy results indicates that single-walled carbon nanotubes are extremely efficient quenchers of fluorescence emission associated with chlorophylls embedded in a natural photosynthetic complex, peridinin-chlorophyll-protein. When deposited on a network of the carbon nanotubes forming a thin film, the emission of the photosynthetic complexes diminishes almost completely. This strong reduction of fluorescence intensity is accompanied with dramatic shortening of the fluorescence lifetime. Concluding, such thin films of carbon nanotubes can be extremely efficient energy acceptors in structures involving biologically functional complexes. - Highlights: • Fluorescence imaging of carbon nanotube - based hybrid structure. • Observation of efficient energy transfer from chlorophylls to carbon nanotubes.

Large-scale single-chirality separation of single-wall carbon nanotubes by simple gel chromatography

Science.gov (United States)

Liu, Huaping; Nishide, Daisuke; Tanaka, Takeshi; Kataura, Hiromichi

2011-01-01

Monostructured single-wall carbon nanotubes (SWCNTs) are important in both scientific research and electronic and biomedical applications; however, the bulk separation of SWCNTs into populations of single-chirality nanotubes remains challenging. Here we report a simple and effective method for the large-scale chirality separation of SWCNTs using a single-surfactant multicolumn gel chromatography method utilizing one surfactant and a series of vertically connected gel columns. This method is based on the structure-dependent interaction strength of SWCNTs with an allyl dextran-based gel. Overloading an SWCNT dispersion on the top column results in the adsorption sites of the column becoming fully occupied by the nanotubes that exhibit the strongest interaction with the gel. The unbound nanotubes flow through to the next column, and the nanotubes with the second strongest interaction with the gel are adsorbed in this stage. In this manner, 13 different (n, m) species were separated. Metallic SWCNTs were finally collected as unbound nanotubes because they exhibited the lowest interaction with the gel. PMID:21556063

Large-Scale Optimization for Bayesian Inference in Complex Systems

Energy Technology Data Exchange (ETDEWEB)

Willcox, Karen [MIT; Marzouk, Youssef [MIT

2013-11-12

The SAGUARO (Scalable Algorithms for Groundwater Uncertainty Analysis and Robust Optimization) Project focused on the development of scalable numerical algorithms for large-scale Bayesian inversion in complex systems that capitalize on advances in large-scale simulation-based optimization and inversion methods. The project was a collaborative effort among MIT, the University of Texas at Austin, Georgia Institute of Technology, and Sandia National Laboratories. The research was directed in three complementary areas: efficient approximations of the Hessian operator, reductions in complexity of forward simulations via stochastic spectral approximations and model reduction, and employing large-scale optimization concepts to accelerate sampling. The MIT--Sandia component of the SAGUARO Project addressed the intractability of conventional sampling methods for large-scale statistical inverse problems by devising reduced-order models that are faithful to the full-order model over a wide range of parameter values; sampling then employs the reduced model rather than the full model, resulting in very large computational savings. Results indicate little effect on the computed posterior distribution. On the other hand, in the Texas--Georgia Tech component of the project, we retain the full-order model, but exploit inverse problem structure (adjoint-based gradients and partial Hessian information of the parameter-to-observation map) to implicitly extract lower dimensional information on the posterior distribution; this greatly speeds up sampling methods, so that fewer sampling points are needed. We can think of these two approaches as ``reduce then sample'' and ``sample then reduce.'' In fact, these two approaches are complementary, and can be used in conjunction with each other. Moreover, they both exploit deterministic inverse problem structure, in the form of adjoint-based gradient and Hessian information of the underlying parameter-to-observation map, to

Large-Eddy Simulations of Flows in Complex Terrain

Science.gov (United States)

Kosovic, B.; Lundquist, K. A.

2011-12-01

Large-eddy simulation as a methodology for numerical simulation of turbulent flows was first developed to study turbulent flows in atmospheric by Lilly (1967). The first LES were carried by Deardorff (1970) who used these simulations to study atmospheric boundary layers. Ever since, LES has been extensively used to study canonical atmospheric boundary layers, in most cases flat plate boundary layers under the assumption of horizontal homogeneity. Carefully designed LES of canonical convective and neutrally stratified and more recently stably stratified atmospheric boundary layers have contributed significantly to development of better understanding of these flows and their parameterizations in large scale models. These simulations were often carried out using codes specifically designed and developed for large-eddy simulations of horizontally homogeneous flows with periodic lateral boundary conditions. Recent developments in multi-scale numerical simulations of atmospheric flows enable numerical weather prediction (NWP) codes such as ARPS (Chow and Street, 2009), COAMPS (Golaz et al., 2009) and Weather Research and Forecasting model, to be used nearly seamlessly across a wide range of atmospheric scales from synoptic down to turbulent scales in atmospheric boundary layers. Before we can with confidence carry out multi-scale simulations of atmospheric flows, NWP codes must be validated for accurate performance in simulating flows over complex or inhomogeneous terrain. We therefore carry out validation of WRF-LES for simulations of flows over complex terrain using data from Askervein Hill (Taylor and Teunissen, 1985, 1987) and METCRAX (Whiteman et al., 2008) field experiments. WRF's nesting capability is employed with a one-way nested inner domain that includes complex terrain representation while the coarser outer nest is used to spin up fully developed atmospheric boundary layer turbulence and thus represent accurately inflow to the inner domain. LES of a

Parameter and State Estimation of Large-Scale Complex Systems Using Python Tools

Directory of Open Access Journals (Sweden)

M. Anushka S. Perera

2015-07-01

Full Text Available This paper discusses the topics related to automating parameter, disturbance and state estimation analysis of large-scale complex nonlinear dynamic systems using free programming tools. For large-scale complex systems, before implementing any state estimator, the system should be analyzed for structural observability and the structural observability analysis can be automated using Modelica and Python. As a result of structural observability analysis, the system may be decomposed into subsystems where some of them may be observable --- with respect to parameter, disturbances, and states --- while some may not. The state estimation process is carried out for those observable subsystems and the optimum number of additional measurements are prescribed for unobservable subsystems to make them observable. In this paper, an industrial case study is considered: the copper production process at Glencore Nikkelverk, Kristiansand, Norway. The copper production process is a large-scale complex system. It is shown how to implement various state estimators, in Python, to estimate parameters and disturbances, in addition to states, based on available measurements.

madSTORM: a superresolution technique for large-scale multiplexing at single-molecule accuracy

Science.gov (United States)

Yi, Jason; Manna, Asit; Barr, Valarie A.; Hong, Jennifer; Neuman, Keir C.; Samelson, Lawrence E.

2016-01-01

Investigation of heterogeneous cellular structures using single-molecule localization microscopy has been limited by poorly defined localization accuracy and inadequate multiplexing capacity. Using fluorescent nanodiamonds as fiducial markers, we define and achieve localization precision required for single-molecule accuracy in dSTORM images. Coupled with this advance, our new multiplexing strategy, madSTORM, allows accurate targeting of multiple molecules using sequential binding and elution of fluorescent antibodies. madSTORM is used on an activated T-cell to localize 25 epitopes, 14 of which are on components of the same multimolecular T-cell receptor complex. We obtain an average localization precision of 2.6 nm, alignment error of 2.0 nm, and molecules within structures. Probing the molecular topology of complex signaling cascades and other heterogeneous networks is feasible with madSTORM. PMID:27708141

Enumeration of Combinatorial Classes of Single Variable Complex Polynomial Vector Fields

DEFF Research Database (Denmark)

Dias, Kealey

A vector field in the space of degree d monic, centered single variable complex polynomial vector fields has a combinatorial structure which can be fully described by a combinatorial data set consisting of an equivalence relation and a marked subset on the integers mod 2d-2, satisfying certain...

Hydrogen-related complexes in Li-diffused ZnO single crystals

Science.gov (United States)

Corolewski, Caleb D.; Parmar, Narendra S.; Lynn, Kelvin G.; McCluskey, Matthew D.

2016-07-01

Zinc oxide (ZnO) is a wide band gap semiconductor and a potential candidate for next generation white solid state lighting applications. In this work, hydrogen-related complexes in lithium diffused ZnO single crystals were studied. In addition to the well-known Li-OH complex, several other hydrogen defects were observed. When a mixture of Li2O and ZnO is used as the dopant source, zinc vacancies are suppressed and the bulk Li concentration is very high (>1019 cm-3). In that case, the predominant hydrogen complex has a vibrational frequency of 3677 cm-1, attributed to surface O-H species. When Li2CO3 is used, a structured blue luminescence band and O-H mode at 3327 cm-1 are observed at 10 K. These observations, along with positron annihilation measurements, suggest a zinc vacancy-hydrogen complex, with an acceptor level ˜0.3 eV above the valence-band maximum. This relatively shallow acceptor could be beneficial for p-type ZnO.

Hydrogen-related complexes in Li-diffused ZnO single crystals

International Nuclear Information System (INIS)

Corolewski, Caleb D.; Parmar, Narendra S.; Lynn, Kelvin G.; McCluskey, Matthew D.

2016-01-01

Zinc oxide (ZnO) is a wide band gap semiconductor and a potential candidate for next generation white solid state lighting applications. In this work, hydrogen-related complexes in lithium diffused ZnO single crystals were studied. In addition to the well-known Li-OH complex, several other hydrogen defects were observed. When a mixture of Li_2O and ZnO is used as the dopant source, zinc vacancies are suppressed and the bulk Li concentration is very high (>10"1"9" cm"−"3). In that case, the predominant hydrogen complex has a vibrational frequency of 3677 cm"−"1, attributed to surface O-H species. When Li_2CO_3 is used, a structured blue luminescence band and O-H mode at 3327 cm"−"1 are observed at 10 K. These observations, along with positron annihilation measurements, suggest a zinc vacancy–hydrogen complex, with an acceptor level ∼0.3 eV above the valence-band maximum. This relatively shallow acceptor could be beneficial for p-type ZnO.

Tetracoordinate Co(II) complexes containing bathocuproine and single molecule magnetism

Czech Academy of Sciences Publication Activity Database

Smolko, L.; Černák, J.; Dušek, Michal; Titiš, J.; Boča, R.

2016-01-01

Roč. 40, č. 8 (2016), s. 6593-6598 ISSN 1144-0546 R&D Projects: GA MŠk LO1603; GA ČR(CZ) GA15-12653S EU Projects: European Commission(XE) CZ.2.16/3.1.00/24510 Institutional support: RVO:68378271 Keywords : crystal structure * single molecule magnetism * Cu(II) complexes Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.269, year: 2016

Optimal number of coarse-grained sites in different components of large biomolecular complexes.

Science.gov (United States)

Sinitskiy, Anton V; Saunders, Marissa G; Voth, Gregory A

2012-07-26

The computational study of large biomolecular complexes (molecular machines, cytoskeletal filaments, etc.) is a formidable challenge facing computational biophysics and biology. To achieve biologically relevant length and time scales, coarse-grained (CG) models of such complexes usually must be built and employed. One of the important early stages in this approach is to determine an optimal number of CG sites in different constituents of a complex. This work presents a systematic approach to this problem. First, a universal scaling law is derived and numerically corroborated for the intensity of the intrasite (intradomain) thermal fluctuations as a function of the number of CG sites. Second, this result is used for derivation of the criterion for the optimal number of CG sites in different parts of a large multibiomolecule complex. In the zeroth-order approximation, this approach validates the empirical rule of taking one CG site per fixed number of atoms or residues in each biomolecule, previously widely used for smaller systems (e.g., individual biomolecules). The first-order corrections to this rule are derived and numerically checked by the case studies of the Escherichia coli ribosome and Arp2/3 actin filament junction. In different ribosomal proteins, the optimal number of amino acids per CG site is shown to differ by a factor of 3.5, and an even wider spread may exist in other large biomolecular complexes. Therefore, the method proposed in this paper is valuable for the optimal construction of CG models of such complexes.

Large-scale image-based profiling of single-cell phenotypes in arrayed CRISPR-Cas9 gene perturbation screens.

Science.gov (United States)

de Groot, Reinoud; Lüthi, Joel; Lindsay, Helen; Holtackers, René; Pelkmans, Lucas

2018-01-23

High-content imaging using automated microscopy and computer vision allows multivariate profiling of single-cell phenotypes. Here, we present methods for the application of the CISPR-Cas9 system in large-scale, image-based, gene perturbation experiments. We show that CRISPR-Cas9-mediated gene perturbation can be achieved in human tissue culture cells in a timeframe that is compatible with image-based phenotyping. We developed a pipeline to construct a large-scale arrayed library of 2,281 sequence-verified CRISPR-Cas9 targeting plasmids and profiled this library for genes affecting cellular morphology and the subcellular localization of components of the nuclear pore complex (NPC). We conceived a machine-learning method that harnesses genetic heterogeneity to score gene perturbations and identify phenotypically perturbed cells for in-depth characterization of gene perturbation effects. This approach enables genome-scale image-based multivariate gene perturbation profiling using CRISPR-Cas9. © 2018 The Authors. Published under the terms of the CC BY 4.0 license.

Structuring and assessing large and complex decision problems using MCDA

DEFF Research Database (Denmark)

Barfod, Michael Bruhn

This paper presents an approach for the structuring and assessing of large and complex decision problems using multi-criteria decision analysis (MCDA). The MCDA problem is structured in a decision tree and assessed using the REMBRANDT technique featuring a procedure for limiting the number of pair...

Large erupted complex odontoma

Directory of Open Access Journals (Sweden)

Vijeev Vasudevan

2009-01-01

Full Text Available Odontomas are a heterogeneous group of jaw bone lesions, classified as odontogenic tumors which usually include well-diversified dental tissues. Odontoma is a term introduced to the literature by Broca in 1867. Trauma, infection and hereditary factors are the possible causes of forming this kind of lesions. Among odontogenic tumors, they constitute about 2/3 of cases. These lesions usually develop slowly and asymptomatically, and in most cases they do not cross the bone borders. Two types of odontoma are recognized: compound and complex. Complex odontomas are less common than the compound variety in the ratio 1:2.3. Eruption of an odontoma in the oral cavity is rare. We present a case of complex odontoma, in which apparent eruption has occurred in the area of the right maxillary second molar region.

Large Scale Emerging Properties from Non Hamiltonian Complex Systems

Directory of Open Access Journals (Sweden)

Marco Bianucci

2017-06-01

Full Text Available The concept of “large scale” depends obviously on the phenomenon we are interested in. For example, in the field of foundation of Thermodynamics from microscopic dynamics, the spatial and time large scales are order of fraction of millimetres and microseconds, respectively, or lesser, and are defined in relation to the spatial and time scales of the microscopic systems. In large scale oceanography or global climate dynamics problems the time scales of interest are order of thousands of kilometres, for space, and many years for time, and are compared to the local and daily/monthly times scales of atmosphere and ocean dynamics. In all the cases a Zwanzig projection approach is, at least in principle, an effective tool to obtain class of universal smooth “large scale” dynamics for few degrees of freedom of interest, starting from the complex dynamics of the whole (usually many degrees of freedom system. The projection approach leads to a very complex calculus with differential operators, that is drastically simplified when the basic dynamics of the system of interest is Hamiltonian, as it happens in Foundation of Thermodynamics problems. However, in geophysical Fluid Dynamics, Biology, and in most of the physical problems the building block fundamental equations of motions have a non Hamiltonian structure. Thus, to continue to apply the useful projection approach also in these cases, we exploit the generalization of the Hamiltonian formalism given by the Lie algebra of dissipative differential operators. In this way, we are able to analytically deal with the series of the differential operators stemming from the projection approach applied to these general cases. Then we shall apply this formalism to obtain some relevant results concerning the statistical properties of the El Niño Southern Oscillation (ENSO.

Single-shot parallel full range complex Fourier-domain optical coherence tomography

International Nuclear Information System (INIS)

Huang Bingjie; Bu Peng; Nan Nan; Wang Xiangzhao

2011-01-01

We present a method of parallel full range complex Fourier-domain optical coherence tomography (FDOCT) that is capable of acquiring an artifacts-free two-dimensional (2-D) cross-sectional image, i.e. a full range B-scan tomogram, by a single shot of 2-D CCD camera. This method is based on a spatial carrier technique, in which the spatial carrier-frequency is instantaneously introduced into the 2-D spectral interferogram registered in parallel FDOCT by using a grating-generated reference beam. The spatial-carrier-contained 2-D spectral interferogram is processed through Fourier transformation to obtain a complex 2-D spectral interferogram. From the 2-D complex spectral interferomgram, a full range B-scan tomogram is reconstructed. The principle of our method is confirmed by imaging an onion sample.

Resolving the Complexity of Human Skin Metagenomes Using Single-Molecule Sequencing

Directory of Open Access Journals (Sweden)

Yu-Chih Tsai

2016-02-01

Full Text Available Deep metagenomic shotgun sequencing has emerged as a powerful tool to interrogate composition and function of complex microbial communities. Computational approaches to assemble genome fragments have been demonstrated to be an effective tool for de novo reconstruction of genomes from these communities. However, the resultant “genomes” are typically fragmented and incomplete due to the limited ability of short-read sequence data to assemble complex or low-coverage regions. Here, we use single-molecule, real-time (SMRT sequencing to reconstruct a high-quality, closed genome of a previously uncharacterized Corynebacterium simulans and its companion bacteriophage from a skin metagenomic sample. Considerable improvement in assembly quality occurs in hybrid approaches incorporating short-read data, with even relatively small amounts of long-read data being sufficient to improve metagenome reconstruction. Using short-read data to evaluate strain variation of this C. simulans in its skin community at single-nucleotide resolution, we observed a dominant C. simulans strain with moderate allelic heterozygosity throughout the population. We demonstrate the utility of SMRT sequencing and hybrid approaches in metagenome quantitation, reconstruction, and annotation.

Resolving the Complexity of Human Skin Metagenomes Using Single-Molecule Sequencing

Science.gov (United States)

Tsai, Yu-Chih; Deming, Clayton; Segre, Julia A.; Kong, Heidi H.; Korlach, Jonas

2016-01-01

ABSTRACT Deep metagenomic shotgun sequencing has emerged as a powerful tool to interrogate composition and function of complex microbial communities. Computational approaches to assemble genome fragments have been demonstrated to be an effective tool for de novo reconstruction of genomes from these communities. However, the resultant “genomes” are typically fragmented and incomplete due to the limited ability of short-read sequence data to assemble complex or low-coverage regions. Here, we use single-molecule, real-time (SMRT) sequencing to reconstruct a high-quality, closed genome of a previously uncharacterized Corynebacterium simulans and its companion bacteriophage from a skin metagenomic sample. Considerable improvement in assembly quality occurs in hybrid approaches incorporating short-read data, with even relatively small amounts of long-read data being sufficient to improve metagenome reconstruction. Using short-read data to evaluate strain variation of this C. simulans in its skin community at single-nucleotide resolution, we observed a dominant C. simulans strain with moderate allelic heterozygosity throughout the population. We demonstrate the utility of SMRT sequencing and hybrid approaches in metagenome quantitation, reconstruction, and annotation. PMID:26861018

Single-molecule magnet behavior in 2,2’-bipyrimidine-bridged dilanthanide complexes

Directory of Open Access Journals (Sweden)

Wen Yu

2016-01-01

Full Text Available A series of 2,2’-bipyrimidine-bridged dinuclear lanthanide complexes with the general formula [Ln(tmhd3]2bpm (tmhd = 2,2,6,6-tetramethyl-3,5-heptanedionate, bpm = 2,2’-bipyrimidine, Ln = Gd(III, 1; Tb(III, 2; Dy(III, 3; Ho(III, 4 and Er(III, 5 has been synthesized and characterized. Sublimation of [Tb(tmhd3]2bpm onto a Au(111 surface leads to the formation of a homogeneous film with hexagonal pattern, which was studied by scanning tunneling microscopy (STM. The bulk magnetic properties of all complexes have been studied comprehensively. The dynamic magnetic behavior of the Dy(III and Er(III compounds clearly exhibits single molecule magnet (SMM characteristics with an energy barrier of 97 and 25 K, respectively. Moreover, micro-SQUID measurements on single crystals confirm their SMM behavior with the presence of hysteresis loops.

Evaluation model of project complexity for large-scale construction projects in Iran - A Fuzzy ANP approach

Directory of Open Access Journals (Sweden)

Aliyeh Kazemi

2016-09-01

Full Text Available Construction projects have always been complex. By growing trend of this complexity, implementations of large-scale constructions become harder. Hence, evaluating and understanding these complexities are critical. Correct evaluation of a project complication can provide executives and managers with good source to use. Fuzzy analytic network process (ANP is a logical and systematic approach toward defining, evaluation, and grading. This method allows for analyzing complex systems, and determining complexity of them. In this study, by taking advantage of fuzzy ANP, effective indexes for development of complications in large-scale construction projects in Iran have been determined and prioritized. The results show socio-political, project system interdependencies, and technological complexity indexes ranked top to three. Furthermore, in comparison of three main huge projects: commercial-administrative, hospital, and skyscrapers, the hospital project had been evaluated as the most complicated. This model is beneficial for professionals in managing large-scale projects.

Hydrogen-related complexes in Li-diffused ZnO single crystals

Energy Technology Data Exchange (ETDEWEB)

Corolewski, Caleb D. [Materials Science and Engineering Program, Washington State University, Pullman, Washington 99164-2814 (United States); Parmar, Narendra S.; Lynn, Kelvin G. [Center for Materials Research, Washington State University, Pullman, Washington 99164-2814 (United States); McCluskey, Matthew D., E-mail: mattmcc@wsu.edu [Materials Science and Engineering Program, Washington State University, Pullman, Washington 99164-2814 (United States); Department of Physics and Astronomy, Washington State University, Pullman, Washington 99164-2814 (United States)

2016-07-21

Zinc oxide (ZnO) is a wide band gap semiconductor and a potential candidate for next generation white solid state lighting applications. In this work, hydrogen-related complexes in lithium diffused ZnO single crystals were studied. In addition to the well-known Li-OH complex, several other hydrogen defects were observed. When a mixture of Li{sub 2}O and ZnO is used as the dopant source, zinc vacancies are suppressed and the bulk Li concentration is very high (>10{sup 19 }cm{sup −3}). In that case, the predominant hydrogen complex has a vibrational frequency of 3677 cm{sup −1}, attributed to surface O-H species. When Li{sub 2}CO{sub 3} is used, a structured blue luminescence band and O-H mode at 3327 cm{sup −1} are observed at 10 K. These observations, along with positron annihilation measurements, suggest a zinc vacancy–hydrogen complex, with an acceptor level ∼0.3 eV above the valence-band maximum. This relatively shallow acceptor could be beneficial for p-type ZnO.

Promising results after single-stage reconstruction of the nipple and areola complex

DEFF Research Database (Denmark)

Børsen-Koch, Mikkel; Bille, Camilla; Thomsen, Jørn B

2013-01-01

Introduction: Reconstruction of the nipple-areola complex (NAC) traditionally marks the end of breast reconstruction. Several different surgical techniques have been described, but most are staged procedures. This paper describes a simple single-stage approach. Material and Methods: We used...... reconstruction was 43 min. (30-50 min.). Conclusion: This simple single-stage NAC reconstruction seems beneficial for both patient and surgeon as it seems to be associated with faster reconstruction and reduced procedure-related time without compromising the aesthetic outcome or the morbidity associated...

The spectra of type IIB flux compactifications at large complex structure

International Nuclear Information System (INIS)

Brodie, Callum; Marsh, M.C. David

2016-01-01

We compute the spectra of the Hessian matrix, H, and the matrix M that governs the critical point equation of the low-energy effective supergravity, as a function of the complex structure and axio-dilaton moduli space in type IIB flux compactifications at large complex structure. We find both spectra analytically in an h − 1,2 +3 real-dimensional subspace of the moduli space, and show that they exhibit a universal structure with highly degenerate eigenvalues, independently of the choice of flux, the details of the compactification geometry, and the number of complex structure moduli. In this subspace, the spectrum of the Hessian matrix contains no tachyons, but there are also no critical points. We show numerically that the spectra of H and M remain highly peaked over a large fraction of the sampled moduli space of explicit Calabi-Yau compactifications with 2 to 5 complex structure moduli. In these models, the scale of the supersymmetric contribution to the scalar masses is strongly linearly correlated with the value of the superpotential over almost the entire moduli space, with particularly strong correlations arising for g s <1. We contrast these results with the expectations from the much-used continuous flux approximation, and comment on the applicability of Random Matrix Theory to the statistical modelling of the string theory landscape.

Synthesis of Large-Scale Single-Crystalline Monolayer WS2 Using a Semi-Sealed Method

Directory of Open Access Journals (Sweden)

Feifei Lan

2018-02-01

Full Text Available As a two-dimensional semiconductor, WS2 has attracted great attention due to its rich physical properties and potential applications. However, it is still difficult to synthesize monolayer single-crystalline WS2 at larger scale. Here, we report the growth of large-scale triangular single-crystalline WS2 with a semi-sealed installation by chemical vapor deposition (CVD. Through this method, triangular single-crystalline WS2 with an average length of more than 300 µm was obtained. The largest one was about 405 μm in length. WS2 triangles with different sizes and thicknesses were analyzed by optical microscope and atomic force microscope (AFM. Their optical properties were evaluated by Raman and photoluminescence (PL spectra. This report paves the way to fabricating large-scale single-crystalline monolayer WS2, which is useful for the growth of high-quality WS2 and its potential applications in the future.

Large-core single-mode rib SU8 waveguide using solvent-assisted microcontact molding.

Science.gov (United States)

Huang, Cheng-Sheng; Wang, Wei-Chih

2008-09-01

This paper describes a novel fabrication technique for constructing a polymer-based large-core single-mode rib waveguide. A negative tone SU8 photoresist with a high optical transmission over a large wavelength range and stable mechanical properties was used as a waveguide material. A waveguide was constructed by using a polydimethylsiloxane stamp combined with a solvent-assisted microcontact molding technique. The effects on the final pattern's geometry of four different process conditions were investigated. Optical simulations were performed using beam propagation method software. Single-mode beam propagation was observed at the output of the simulated waveguide as well as the actual waveguide through the microscope image.

Research status of large mode area single polarization active fiber

Science.gov (United States)

Xiao, Chun; Zhang, Ge; Yang, Bin-hua; Cheng, Wei-feng; Gu, Shao-yi

2018-03-01

As high power fiber laser used more and more widely, to increase the output power of fiber laser and beam quality improvement have become an important goal for the development of high power fiber lasers. The use of large mode fiber is the most direct and effective way to solve the nonlinear effect and fiber damage in the fiber laser power lifting process. In order to reduce the effect of polarization of the fiber laser system, the study found that when introduces a birefringence in the single-mode fiber, the polarization state changes caused by the birefringence is far greater than the random polarization state changes, then the external disturbance is completely submerged, finally the polarization can be controlled and stabilized. Through the fine design of the fiber structure, if the birefringence is high enough to achieve the separation of the two polarization states, the fiber will have a different cut-off mechanism to eliminate polarization which is not need, which will realize single mode single polarization transmission in a band. In this paper, different types of single polarization fiber design are presented and the application of these fibers are also discussed.

Software quality assurance: in large scale and complex software-intensive systems

NARCIS (Netherlands)

Mistrik, I.; Soley, R.; Ali, N.; Grundy, J.; Tekinerdogan, B.

2015-01-01

Software Quality Assurance in Large Scale and Complex Software-intensive Systems presents novel and high-quality research related approaches that relate the quality of software architecture to system requirements, system architecture and enterprise-architecture, or software testing. Modern software

European accelerator facilities for single event effects testing

Energy Technology Data Exchange (ETDEWEB)

Adams, L; Nickson, R; Harboe-Sorensen, R [ESA-ESTEC, Noordwijk (Netherlands); Hajdas, W; Berger, G

1997-03-01

Single event effects are an important hazard to spacecraft and payloads. The advances in component technology, with shrinking dimensions and increasing complexity will give even more importance to single event effects in the future. The ground test facilities are complex and expensive and the complexities of installing a facility are compounded by the requirement that maximum control is to be exercised by users largely unfamiliar with accelerator technology. The PIF and the HIF are the result of experience gained in the field of single event effects testing and represent a unique collaboration between space technology and accelerator experts. Both facilities form an essential part of the European infrastructure supporting space projects. (J.P.N.)

Protein complex prediction in large ontology attributed protein-protein interaction networks.

Science.gov (United States)

Zhang, Yijia; Lin, Hongfei; Yang, Zhihao; Wang, Jian; Li, Yanpeng; Xu, Bo

2013-01-01

Protein complexes are important for unraveling the secrets of cellular organization and function. Many computational approaches have been developed to predict protein complexes in protein-protein interaction (PPI) networks. However, most existing approaches focus mainly on the topological structure of PPI networks, and largely ignore the gene ontology (GO) annotation information. In this paper, we constructed ontology attributed PPI networks with PPI data and GO resource. After constructing ontology attributed networks, we proposed a novel approach called CSO (clustering based on network structure and ontology attribute similarity). Structural information and GO attribute information are complementary in ontology attributed networks. CSO can effectively take advantage of the correlation between frequent GO annotation sets and the dense subgraph for protein complex prediction. Our proposed CSO approach was applied to four different yeast PPI data sets and predicted many well-known protein complexes. The experimental results showed that CSO was valuable in predicting protein complexes and achieved state-of-the-art performance.

Influence of the large-small split effect on strategy choice in complex subtraction.

Science.gov (United States)

Xiang, Yan Hui; Wu, Hao; Shang, Rui Hong; Chao, Xiaomei; Ren, Ting Ting; Zheng, Li Ling; Mo, Lei

2018-04-01

Two main theories have been used to explain the arithmetic split effect: decision-making process theory and strategy choice theory. Using the inequality paradigm, previous studies have confirmed that individuals tend to adopt a plausibility-checking strategy and a whole-calculation strategy to solve large and small split problems in complex addition arithmetic, respectively. This supports strategy choice theory, but it is unknown whether this theory also explains performance in solving different split problems in complex subtraction arithmetic. This study used small, intermediate and large split sizes, with each split condition being further divided into problems requiring and not requiring borrowing. The reaction times (RTs) for large and intermediate splits were significantly shorter than those for small splits, while accuracy was significantly higher for large and middle splits than for small splits, reflecting no speed-accuracy trade-off. Further, RTs and accuracy differed significantly between the borrow and no-borrow conditions only for small splits. This study indicates that strategy choice theory is suitable to explain the split effect in complex subtraction arithmetic. That is, individuals tend to choose the plausibility-checking strategy or the whole-calculation strategy according to the split size. © 2016 International Union of Psychological Science.

GraDeR: Membrane Protein Complex Preparation for Single-Particle Cryo-EM.

Science.gov (United States)

Hauer, Florian; Gerle, Christoph; Fischer, Niels; Oshima, Atsunori; Shinzawa-Itoh, Kyoko; Shimada, Satoru; Yokoyama, Ken; Fujiyoshi, Yoshinori; Stark, Holger

2015-09-01

We developed a method, named GraDeR, which substantially improves the preparation of membrane protein complexes for structure determination by single-particle cryo-electron microscopy (cryo-EM). In GraDeR, glycerol gradient centrifugation is used for the mild removal of free detergent monomers and micelles from lauryl maltose-neopentyl glycol detergent stabilized membrane complexes, resulting in monodisperse and stable complexes to which standard processes for water-soluble complexes can be applied. We demonstrate the applicability of the method on three different membrane complexes, including the mammalian FoF1 ATP synthase. For this highly dynamic and fragile rotary motor, we show that GraDeR allows visualizing the asymmetry of the F1 domain, which matches the ground state structure of the isolated domain. Therefore, the present cryo-EM structure of FoF1 ATP synthase provides direct structural evidence for Boyer's binding change mechanism in the context of the intact enzyme. Copyright © 2015 Elsevier Ltd. All rights reserved.

Contribution of Large Region Joint Associations to Complex Traits Genetics

Science.gov (United States)

Paré, Guillaume; Asma, Senay; Deng, Wei Q.

2015-01-01

A polygenic model of inheritance, whereby hundreds or thousands of weakly associated variants contribute to a trait’s heritability, has been proposed to underlie the genetic architecture of complex traits. However, relatively few genetic variants have been positively identified so far and they collectively explain only a small fraction of the predicted heritability. We hypothesized that joint association of multiple weakly associated variants over large chromosomal regions contributes to complex traits variance. Confirmation of such regional associations can help identify new loci and lead to a better understanding of known ones. To test this hypothesis, we first characterized the ability of commonly used genetic association models to identify large region joint associations. Through theoretical derivation and simulation, we showed that multivariate linear models where multiple SNPs are included as independent predictors have the most favorable association profile. Based on these results, we tested for large region association with height in 3,740 European participants from the Health and Retirement Study (HRS) study. Adjusting for SNPs with known association with height, we demonstrated clustering of weak associations (p = 2x10-4) in regions extending up to 433.0 Kb from known height loci. The contribution of regional associations to phenotypic variance was estimated at 0.172 (95% CI 0.063-0.279; p < 0.001), which compared favorably to 0.129 explained by known height variants. Conversely, we showed that suggestively associated regions are enriched for known height loci. To extend our findings to other traits, we also tested BMI, HDLc and CRP for large region associations, with consistent results for CRP. Our results demonstrate the presence of large region joint associations and suggest these can be used to pinpoint weakly associated SNPs. PMID:25856144

Anisotropic charge transport in large single crystals of π-conjugated organic molecules.

Science.gov (United States)

Hourani, Wael; Rahimi, Khosrow; Botiz, Ioan; Koch, Felix Peter Vinzenz; Reiter, Günter; Lienerth, Peter; Heiser, Thomas; Bubendorff, Jean-Luc; Simon, Laurent

2014-05-07

The electronic properties of organic semiconductors depend strongly on the nature of the molecules, their conjugation and conformation, their mutual distance and the orientation between adjacent molecules. Variations of intramolecular distances and conformation disturb the conjugation and perturb the delocalization of charges. As a result, the mobility considerably decreases compared to that of a covalently well-organized crystal. Here, we present electrical characterization of large single crystals made of the regioregular octamer of 3-hexyl-thiophene (3HT)8 using a conductive-atomic force microscope (C-AFM) in air. We find a large anisotropy in the conduction with charge mobility values depending on the crystallographic orientation of the single crystal. The smaller conduction is in the direction of π-π stacking (along the long axis of the single crystal) with a mobility value in the order of 10(-3) cm(2) V(-1) s(-1), and the larger one is along the molecular axis (in the direction normal to the single crystal surface) with a mobility value in the order of 0.5 cm(2) V(-1) s(-1). The measured current-voltage (I-V) curves showed that along the molecular axis, the current followed an exponential dependence corresponding to an injection mode. In the π-π stacking direction, the current exhibits a space charge limited current (SCLC) behavior, which allows us to estimate the charge carrier mobility.

Large Variability in the Diversity of Physiologically Complex Surgical Procedures Exists Nationwide Among All Hospitals Including Among Large Teaching Hospitals.

Science.gov (United States)

Dexter, Franklin; Epstein, Richard H; Thenuwara, Kokila; Lubarsky, David A

2017-11-22

Multiple previous studies have shown that having a large diversity of procedures has a substantial impact on quality management of hospital surgical suites. At hospitals with substantial diversity, unless sophisticated statistical methods suitable for rare events are used, anesthesiologists working in surgical suites will have inaccurate predictions of surgical blood usage, case durations, cost accounting and price transparency, times remaining in late running cases, and use of intraoperative equipment. What is unknown is whether large diversity is a feature of only a few very unique set of hospitals nationwide (eg, the largest hospitals in each state or province). The 2013 United States Nationwide Readmissions Database was used to study heterogeneity among 1981 hospitals in their diversities of physiologically complex surgical procedures (ie, the procedure codes). The diversity of surgical procedures performed at each hospital was quantified using a summary measure, the number of different physiologically complex surgical procedures commonly performed at the hospital (ie, 1/Herfindahl). A total of 53.9% of all hospitals commonly performed 3-fold larger diversity (ie, >30 commonly performed physiologically complex procedures). Larger hospitals had greater diversity than the small- and medium-sized hospitals (P 30 procedures (lower 99% CL, 71.9% of hospitals). However, there was considerable variability among the large teaching hospitals in their diversity (interquartile range of the numbers of commonly performed physiologically complex procedures = 19.3; lower 99% CL, 12.8 procedures). The diversity of procedures represents a substantive differentiator among hospitals. Thus, the usefulness of statistical methods for operating room management should be expected to be heterogeneous among hospitals. Our results also show that "large teaching hospital" alone is an insufficient description for accurate prediction of the extent to which a hospital sustains the

Parasitic neutron bragg reflections from large imperfect single crystals

Energy Technology Data Exchange (ETDEWEB)

Naguib, K.; Adib, M

1998-12-01

A formula is given which allows to calculate the contribution of the total Bragg scattering from different (hkl) planes to the neutron transmission through a large imperfect single crystals. The formula takes into account the crystal structure type, its mosaic spread value, the plane along which the crystal surface is cut along and its orientation with respect to the neutron beam direction. A computer program ISCANF-1 was developed to calculate the total parasitic scattering cross-section from different (hkl) planes as well as the nuclear and diffuse scattering cross-sections. The ISCANF-1 program was applied to calculate the neutron attenuation through Cu and Zn single crystals, each of them cut along (002) planes. The calculated values of the neutron transmission through Cu and Zn crystals were compared with the measured ones in the wavelength range 0.21-0.47 nm and 0.04-0.52 nm respectively. The measured and calculated values were found to be in reasonable agreement within the statistical accuracy. The computer program ISCANF-1 was also applied to investigate the effect of parasitic Bragg scattering on the neutron filtering characteristics of both Zn and Cu single crystals as a function of their physical parameters.

Parasitic neutron bragg reflections from large imperfect single crystals

International Nuclear Information System (INIS)

Naguib, K.; Adib, M.

1998-01-01

A formula is given which allows to calculate the contribution of the total Bragg scattering from different (hkl) planes to the neutron transmission through a large imperfect single crystals. The formula takes into account the crystal structure type, its mosaic spread value, the plane along which the crystal surface is cut along and its orientation with respect to the neutron beam direction. A computer program ISCANF-1 was developed to calculate the total parasitic scattering cross-section from different (hkl) planes as well as the nuclear and diffuse scattering cross-sections. The ISCANF-1 program was applied to calculate the neutron attenuation through Cu and Zn single crystals, each of them cut along (002) planes. The calculated values of the neutron transmission through Cu and Zn crystals were compared with the measured ones in the wavelength range 0.21-0.47 nm and 0.04-0.52 nm respectively. The measured and calculated values were found to be in reasonable agreement within the statistical accuracy. The computer program ISCANF-1 was also applied to investigate the effect of parasitic Bragg scattering on the neutron filtering characteristics of both Zn and Cu single crystals as a function of their physical parameters

Control Algorithms for Large-scale Single-axis Photovoltaic Trackers

Directory of Open Access Journals (Sweden)

Dorian Schneider

2012-01-01

Full Text Available The electrical yield of large-scale photovoltaic power plants can be greatly improved by employing solar trackers. While fixed-tilt superstructures are stationary and immobile, trackers move the PV-module plane in order to optimize its alignment to the sun. This paper introduces control algorithms for single-axis trackers (SAT, including a discussion for optimal alignment and backtracking. The results are used to simulate and compare the electrical yield of fixed-tilt and SAT systems. The proposed algorithms have been field tested, and are in operation in solar parks worldwide.

Fluorescence spectral fluctuations of single LH2 complexes from Rhodopseudomonas acidophila strain 10050

NARCIS (Netherlands)

Rutkauskas, D.; Novoderezkhin, V.; Cogdell, R.J.; van Grondelle, R.

2004-01-01

We have investigated the energy landscape of the bacterial photosynthetic peripheral light-harvesting complex LH2 of purple bacterium Rhodopseudomonas acidophila by monitoring sequences of fluorescence spectra of single LH2 assemblies, at room temperature, with different excitation intensities as

Single Crystal Piezomotor for Large Stroke, High Precision and Cryogenic Actuations, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — TRS Technologies proposes a novel single crystal piezomotor for large stroke, high precision, and cryogenic actuations with capability of position set-hold with...

GraMi: Generalized Frequent Pattern Mining in a Single Large Graph

KAUST Repository

Saeedy, Mohammed El

2011-11-01

Mining frequent subgraphs is an important operation on graphs. Most existing work assumes a database of many small graphs, but modern applications, such as social networks, citation graphs or protein-protein interaction in bioinformatics, are modeled as a single large graph. Interesting interactions in such applications may be transitive (e.g., friend of a friend). Existing methods, however, search for frequent isomorphic (i.e., exact match) subgraphs and cannot discover many useful patterns. In this paper the authors propose GRAMI, a framework that generalizes frequent subgraph mining in a large single graph. GRAMI discovers frequent patterns. A pattern is a graph where edges are generalized to distance-constrained paths. Depending on the definition of the distance function, many instantiations of the framework are possible. Both directed and undirected graphs, as well as multiple labels per vertex, are supported. The authors developed an efficient implementation of the framework that models the frequency resolution phase as a constraint satisfaction problem, in order to avoid the costly enumeration of all instances of each pattern in the graph. The authors also implemented CGRAMI, a version that supports structural and semantic constraints; and AGRAMI, an approximate version that supports very large graphs. The experiments on real data demonstrate that the authors framework is up to 3 orders of magnitude faster and discovers more interesting patterns than existing approaches.

Defining Execution Viewpoints for a Large and Complex Software-Intensive System

NARCIS (Netherlands)

Callo Arias, Trosky B.; America, Pierre; Avgeriou, Paris

2009-01-01

An execution view is an important asset for developing large and complex systems. An execution view helps practitioners to describe, analyze, and communicate what a software system does at runtime and how it does it. In this paper, we present an approach to define execution viewpoints for an

Large eddy simulation modeling of particle-laden flows in complex terrain

Science.gov (United States)

Salesky, S.; Giometto, M. G.; Chamecki, M.; Lehning, M.; Parlange, M. B.

2017-12-01

The transport, deposition, and erosion of heavy particles over complex terrain in the atmospheric boundary layer is an important process for hydrology, air quality forecasting, biology, and geomorphology. However, in situ observations can be challenging in complex terrain due to spatial heterogeneity. Furthermore, there is a need to develop numerical tools that can accurately represent the physics of these multiphase flows over complex surfaces. We present a new numerical approach to accurately model the transport and deposition of heavy particles in complex terrain using large eddy simulation (LES). Particle transport is represented through solution of the advection-diffusion equation including terms that represent gravitational settling and inertia. The particle conservation equation is discretized in a cut-cell finite volume framework in order to accurately enforce mass conservation. Simulation results will be validated with experimental data, and numerical considerations required to enforce boundary conditions at the surface will be discussed. Applications will be presented in the context of snow deposition and transport, as well as urban dispersion.

Single-cell technologies in environmental omics

KAUST Repository

Kodzius, Rimantas

2015-10-22

Environmental studies are primarily done by culturing isolated microorganisms or by amplifying and sequencing conserved genes. Difficulties understanding the complexity of large numbers of various microorganisms in an environment led to the development of techniques to enrich specific microorganisms for upstream analysis, ultimately leading to single-cell isolation and analyses. We discuss the significance of single-cell technologies in omics studies with focus on metagenomics and metatranscriptomics. We propose that by reducing sample heterogeneity using single-cell genomics, metaomic studies can be simplified.

Single-cell technologies in environmental omics

KAUST Repository

Kodzius, Rimantas; Gojobori, Takashi

2015-01-01

Environmental studies are primarily done by culturing isolated microorganisms or by amplifying and sequencing conserved genes. Difficulties understanding the complexity of large numbers of various microorganisms in an environment led to the development of techniques to enrich specific microorganisms for upstream analysis, ultimately leading to single-cell isolation and analyses. We discuss the significance of single-cell technologies in omics studies with focus on metagenomics and metatranscriptomics. We propose that by reducing sample heterogeneity using single-cell genomics, metaomic studies can be simplified.

Complex singularities of the critical potential in the large-N limit

International Nuclear Information System (INIS)

Meurice, Y.

2003-01-01

We show with two numerical examples that the conventional expansion in powers of the field for the critical potential of 3-dimensional O(N) models in the large-N limit does not converge for values of φ 2 larger than some critical value. This can be explained by the existence of conjugated branch points in the complex φ 2 plane. Pade approximants [L+3/L] for the critical potential apparently converge at large φ 2 . This allows high-precision calculation of the fixed point in a more suitable set of coordinates. We argue that the singularities are generic and not an artifact of the large-N limit. We show that ignoring these singularities may lead to inaccurate approximations

Sedimentation Velocity Analysis of Large Oligomeric Chromatin Complexes Using Interference Detection.

Science.gov (United States)

Rogge, Ryan A; Hansen, Jeffrey C

2015-01-01

Sedimentation velocity experiments measure the transport of molecules in solution under centrifugal force. Here, we describe a method for monitoring the sedimentation of very large biological molecular assemblies using the interference optical systems of the analytical ultracentrifuge. The mass, partial-specific volume, and shape of macromolecules in solution affect their sedimentation rates as reflected in the sedimentation coefficient. The sedimentation coefficient is obtained by measuring the solute concentration as a function of radial distance during centrifugation. Monitoring the concentration can be accomplished using interference optics, absorbance optics, or the fluorescence detection system, each with inherent advantages. The interference optical system captures data much faster than these other optical systems, allowing for sedimentation velocity analysis of extremely large macromolecular complexes that sediment rapidly at very low rotor speeds. Supramolecular oligomeric complexes produced by self-association of 12-mer chromatin fibers are used to illustrate the advantages of the interference optics. Using interference optics, we show that chromatin fibers self-associate at physiological divalent salt concentrations to form structures that sediment between 10,000 and 350,000S. The method for characterizing chromatin oligomers described in this chapter will be generally useful for characterization of any biological structures that are too large to be studied by the absorbance optical system. © 2015 Elsevier Inc. All rights reserved.

Simplified paraboloid phase model-based phase tracker for demodulation of a single complex fringe.

Science.gov (United States)

He, A; Deepan, B; Quan, C

2017-09-01

A regularized phase tracker (RPT) is an effective method for demodulation of single closed-fringe patterns. However, lengthy calculation time, specially designed scanning strategy, and sign-ambiguity problems caused by noise and saddle points reduce its effectiveness, especially for demodulating large and complex fringe patterns. In this paper, a simplified paraboloid phase model-based regularized phase tracker (SPRPT) is proposed. In SPRPT, first and second phase derivatives are pre-determined by the density-direction-combined method and discrete higher-order demodulation algorithm, respectively. Hence, cost function is effectively simplified to reduce the computation time significantly. Moreover, pre-determined phase derivatives improve the robustness of the demodulation of closed, complex fringe patterns. Thus, no specifically designed scanning strategy is needed; nevertheless, it is robust against the sign-ambiguity problem. The paraboloid phase model also assures better accuracy and robustness against noise. Both the simulated and experimental fringe patterns (obtained using electronic speckle pattern interferometry) are used to validate the proposed method, and a comparison of the proposed method with existing RPT methods is carried out. The simulation results show that the proposed method has achieved the highest accuracy with less computational time. The experimental result proves the robustness and the accuracy of the proposed method for demodulation of noisy fringe patterns and its feasibility for static and dynamic applications.

Synthesis and structure of large single crystalline silver hexagonal microplates suitable for micromachining

Energy Technology Data Exchange (ETDEWEB)

Lyutov, Dimitar L.; Genkov, Kaloyan V.; Zyapkov, Anton D.; Tsutsumanova, Gichka G.; Tzonev, Atanas N. [Department of Solid State Physics and Microelectronics, Faculty of Physics, University of Sofia, 5, J. Bouchier Blvd, Sofia (Bulgaria); Lyutov, Lyudmil G. [Department of General and Inorganic Chemistry, Faculty of Chemistry, University of Sofia, 1, J. Bouchier Blvd, Sofia (Bulgaria); Russev, Stoyan C., E-mail: scr@phys.uni-sofia.bg [Department of Solid State Physics and Microelectronics, Faculty of Physics, University of Sofia, 5, J. Bouchier Blvd, Sofia (Bulgaria)

2014-01-15

We report a simple one-step synthesis method of large single crystalline Ag (111) hexagonal microplates with sharp edges and a size of up to tens of microns. Single silver crystals were produced by reduction silver nitrate aqueous solution with 4-(methylamino)phenol sulfate. Scanning and transmission electron microscopy, energy-dispersive X-ray spectroscopy, selected area electron diffraction and optical microscopy techniques were combined to characterize the crystals. It is shown that the microplates can be easily dispersed and transferred as single objects onto different substrates and subsequently used as a high quality plasmonic starting material for micromachining of future nanocomponents, using modern top-down techniques like focused-ion beam milling and gas injection deposition. - Highlights: • Synthesis of large Ag hexagonal microplates with high crystallinity. • It is shown and discussed the role of twinning for the anisotropic 2D growth. • The Ag plates are stable in water and can be dispersed onto different substrates. • Their positioning and subsequent micromachining with FIB/GIS is demonstrated. • Suitable starting material for future plasmonic nanocomponents.

Universal properties of type IIB and F-theory flux compactifications at large complex structure

International Nuclear Information System (INIS)

Marsh, M.C. David; Sousa, Kepa

2016-01-01

We consider flux compactifications of type IIB string theory and F-theory in which the respective superpotentials at large complex structure are dominated by cubic or quartic terms in the complex structure moduli. In this limit, the low-energy effective theory exhibits universal properties that are insensitive to the details of the compactification manifold or the flux configuration. Focussing on the complex structure and axio-dilaton sector, we show that there are no vacua in this region and the spectrum of the Hessian matrix is highly peaked and consists only of three distinct eigenvalues (0, 2m 3/2 2 and 8m 3/2 2 ), independently of the number of moduli. We briefly comment on how the inclusion of Kähler moduli affect these findings. Our results generalise those of Brodie & Marsh http://dx.doi.org/10.1007/JHEP01(2016)037, in which these universal properties were found in a subspace of the large complex structure limit of type IIB compactifications.

Statistical analysis of error rate of large-scale single flux quantum logic circuit by considering fluctuation of timing parameters

International Nuclear Information System (INIS)

Yamanashi, Yuki; Masubuchi, Kota; Yoshikawa, Nobuyuki

2016-01-01

The relationship between the timing margin and the error rate of the large-scale single flux quantum logic circuits is quantitatively investigated to establish a timing design guideline. We observed that the fluctuation in the set-up/hold time of single flux quantum logic gates caused by thermal noises is the most probable origin of the logical error of the large-scale single flux quantum circuit. The appropriate timing margin for stable operation of the large-scale logic circuit is discussed by taking the fluctuation of setup/hold time and the timing jitter in the single flux quantum circuits. As a case study, the dependence of the error rate of the 1-million-bit single flux quantum shift register on the timing margin is statistically analyzed. The result indicates that adjustment of timing margin and the bias voltage is important for stable operation of a large-scale SFQ logic circuit.

Statistical analysis of error rate of large-scale single flux quantum logic circuit by considering fluctuation of timing parameters

Energy Technology Data Exchange (ETDEWEB)

Yamanashi, Yuki, E-mail: yamanasi@ynu.ac.jp [Department of Electrical and Computer Engineering, Yokohama National University, Tokiwadai 79-5, Hodogaya-ku, Yokohama 240-8501 (Japan); Masubuchi, Kota; Yoshikawa, Nobuyuki [Department of Electrical and Computer Engineering, Yokohama National University, Tokiwadai 79-5, Hodogaya-ku, Yokohama 240-8501 (Japan)

2016-11-15

The relationship between the timing margin and the error rate of the large-scale single flux quantum logic circuits is quantitatively investigated to establish a timing design guideline. We observed that the fluctuation in the set-up/hold time of single flux quantum logic gates caused by thermal noises is the most probable origin of the logical error of the large-scale single flux quantum circuit. The appropriate timing margin for stable operation of the large-scale logic circuit is discussed by taking the fluctuation of setup/hold time and the timing jitter in the single flux quantum circuits. As a case study, the dependence of the error rate of the 1-million-bit single flux quantum shift register on the timing margin is statistically analyzed. The result indicates that adjustment of timing margin and the bias voltage is important for stable operation of a large-scale SFQ logic circuit.

Studies on combined model based on functional objectives of large scale complex engineering

Science.gov (United States)

Yuting, Wang; Jingchun, Feng; Jiabao, Sun

2018-03-01

As various functions were included in large scale complex engineering, and each function would be conducted with completion of one or more projects, combined projects affecting their functions should be located. Based on the types of project portfolio, the relationship of projects and their functional objectives were analyzed. On that premise, portfolio projects-technics based on their functional objectives were introduced, then we studied and raised the principles of portfolio projects-technics based on the functional objectives of projects. In addition, The processes of combined projects were also constructed. With the help of portfolio projects-technics based on the functional objectives of projects, our research findings laid a good foundation for management of large scale complex engineering portfolio management.

A large scale analysis of information-theoretic network complexity measures using chemical structures.

Directory of Open Access Journals (Sweden)

Matthias Dehmer

Full Text Available This paper aims to investigate information-theoretic network complexity measures which have already been intensely used in mathematical- and medicinal chemistry including drug design. Numerous such measures have been developed so far but many of them lack a meaningful interpretation, e.g., we want to examine which kind of structural information they detect. Therefore, our main contribution is to shed light on the relatedness between some selected information measures for graphs by performing a large scale analysis using chemical networks. Starting from several sets containing real and synthetic chemical structures represented by graphs, we study the relatedness between a classical (partition-based complexity measure called the topological information content of a graph and some others inferred by a different paradigm leading to partition-independent measures. Moreover, we evaluate the uniqueness of network complexity measures numerically. Generally, a high uniqueness is an important and desirable property when designing novel topological descriptors having the potential to be applied to large chemical databases.

Single incision pediatric endoscopic surgery: advantages of relatively large incision

International Nuclear Information System (INIS)

Yilmaz, E.; Afsarlar, E.; Karaman, I.

2015-01-01

To describe Single Incision Pediatric Endoscopic Surgery (SIPES) performed on children with various diagnoses, emphasizing its advantages. Study Design: An observational case series. Place and Duration of Study: Department of Pediatric Surgery, Dr. Sami Ulus Maternity and Child Health Hospital, Ankara, Turkey, from January 2011 to November 2014. Methodology: A review of patient charts was conducted in which SIPES was preferred as the surgical procedure. Patient demographics, operative details, operative time, clinical outcomes, postoperative pain and cosmesis were analyzed. Results: SIPES was performed on 45 patients (21 girls, 24 boys). Thirty-three appendectomies, 5 varicocelectomies, 3 oophorectomies, 2 ovarian and one paratubal cyst excision, and one fallopian tube excision were performed. All except one procedures were performed through our standard 2cm umbilical vertical or smile incision. In 18 cases, abdominal irrigation/aspiration was easily performed through the existing larger incision, as is done with open surgical technique. None of the patients had early postoperative shoulder/back pain since complete disinflation of CO/sub 2/ could be ensured. All of the patients/parents were satisfied with the cosmesis. Conclusion: SIPES has the advantages of limiting the surgical scar to within the umbilicus and providing easy disinflation of CO/sub 2/, allowing intraabdominal cleaning and extraction of large volume tissue samples through a single large umbilical incision. (author)

Interaction of complexes I, III, and IV within the bovine respirasome by single particle cryoelectron tomography

NARCIS (Netherlands)

Dudkina, Natalya V.; Kudryashev, Mikhail; Stahlberg, Henning; Boekema, Egbert J.

2011-01-01

The respirasome is a multisubunit supercomplex of the respiratory chain in mitochondria. Here we report the 3D reconstruction of the bovine heart respirasome, composed of dimeric complex III and single copies of complex I and IV, at about 2.2-nm resolution, determined by cryoelectron tomography and

Spin-polarized transport through single-molecule magnet Mn6 complexes

KAUST Repository

Cremades, Eduard; Pemmaraju, C. D.; Sanvito, Stefano; Ruiz, Eliseo

2013-01-01

The coherent transport properties of a device, constructed by sandwiching a Mn6 single-molecule magnet between two gold surfaces, are studied theoretically by using the non-equilibrium Green's function approach combined with density functional theory. Two spin states of such Mn6 complexes are explored, namely the ferromagnetically coupled configuration of the six MnIII cations, leading to the S = 12 ground state, and the low S = 4 spin state. For voltages up to 1 volt the S = 12 ground state shows a current one order of magnitude larger than that of the S = 4 state. Furthermore this is almost completely spin-polarized, since the Mn6 frontier molecular orbitals for S = 12 belong to the same spin manifold. As such the high-anisotropy Mn6 molecule appears as a promising candidate for implementing, at the single molecular level, both spin-switches and low-temperature spin-valves. © 2013 The Royal Society of Chemistry.

Spin-polarized transport through single-molecule magnet Mn6 complexes

KAUST Repository

Cremades, Eduard

2013-01-01

The coherent transport properties of a device, constructed by sandwiching a Mn6 single-molecule magnet between two gold surfaces, are studied theoretically by using the non-equilibrium Green\\'s function approach combined with density functional theory. Two spin states of such Mn6 complexes are explored, namely the ferromagnetically coupled configuration of the six MnIII cations, leading to the S = 12 ground state, and the low S = 4 spin state. For voltages up to 1 volt the S = 12 ground state shows a current one order of magnitude larger than that of the S = 4 state. Furthermore this is almost completely spin-polarized, since the Mn6 frontier molecular orbitals for S = 12 belong to the same spin manifold. As such the high-anisotropy Mn6 molecule appears as a promising candidate for implementing, at the single molecular level, both spin-switches and low-temperature spin-valves. © 2013 The Royal Society of Chemistry.

Max-min SINR low complexity transceiver design for single cell massive MIMO

KAUST Repository

Sifaou, Houssem; Kammoun, Abla; Sanguinetti, Luca; Debbah, Mé rouane; Alouini, Mohamed-Slim

2016-01-01

This work focuses on large scale multi-user MIMO systems in which the base station (BS) outfitted with M antennas communicates with K single antenna user equipments (UEs). In particular, we aim at designing the linear precoder and receiver

Final Report: Large-Scale Optimization for Bayesian Inference in Complex Systems

Energy Technology Data Exchange (ETDEWEB)

Ghattas, Omar [The University of Texas at Austin

2013-10-15

The SAGUARO (Scalable Algorithms for Groundwater Uncertainty Analysis and Robust Optimiza- tion) Project focuses on the development of scalable numerical algorithms for large-scale Bayesian inversion in complex systems that capitalize on advances in large-scale simulation-based optimiza- tion and inversion methods. Our research is directed in three complementary areas: efficient approximations of the Hessian operator, reductions in complexity of forward simulations via stochastic spectral approximations and model reduction, and employing large-scale optimization concepts to accelerate sampling. Our efforts are integrated in the context of a challenging testbed problem that considers subsurface reacting flow and transport. The MIT component of the SAGUARO Project addresses the intractability of conventional sampling methods for large-scale statistical inverse problems by devising reduced-order models that are faithful to the full-order model over a wide range of parameter values; sampling then employs the reduced model rather than the full model, resulting in very large computational savings. Results indicate little effect on the computed posterior distribution. On the other hand, in the Texas-Georgia Tech component of the project, we retain the full-order model, but exploit inverse problem structure (adjoint-based gradients and partial Hessian information of the parameter-to- observation map) to implicitly extract lower dimensional information on the posterior distribution; this greatly speeds up sampling methods, so that fewer sampling points are needed. We can think of these two approaches as "reduce then sample" and "sample then reduce." In fact, these two approaches are complementary, and can be used in conjunction with each other. Moreover, they both exploit deterministic inverse problem structure, in the form of adjoint-based gradient and Hessian information of the underlying parameter-to-observation map, to achieve their speedups.

Large-area aligned growth of single-crystalline organic nanowire arrays for high-performance photodetectors

International Nuclear Information System (INIS)

Wu Yiming; Zhang Xiujuan; Pan Huanhuan; Zhang Xiwei; Zhang Yuping; Zhang Xiaozhen; Jie Jiansheng

2013-01-01

Due to their extraordinary properties, single-crystalline organic nanowires (NWs) are important building blocks for future low-cost and efficient nano-optoelectronic devices. However, it remains a critical challenge to assemble organic NWs rationally in an orientation-, dimensionality- and location-controlled manner. Herein, we demonstrate a feasible method for aligned growth of single-crystalline copper phthalocyanine (CuPc) NW arrays with high density, large-area uniformity and perfect crossed alignment by using Au film as a template. The growth process was investigated in detail. The Au film was found to have a critical function in the aligned growth of NWs, but may only serve as the active site for NW nucleation because of the large surface energy, as well as direct the subsequent aligned growth. The as-prepared NWs were then transferred to construct single NW-based photoconductive devices, which demonstrated excellent photoresponse properties with robust stability and reproducibility; the device showed a high switching ratio of ∼180, a fast response speed of ∼100 ms and could stand continuous operation up to 2 h. Importantly, this strategy can be extended to other organic molecules for their synthesis of NW arrays, revealing great potential for use in the construction of large-scale high-performance functional nano-optoelectronic devices. (paper)

Towards controlled innovation of complex objects.: A sociotechnical approach to describing ship design

OpenAIRE

van Bruinessen, T.M.

2016-01-01

Within the ship design industry, and in particular in the development of large, complex and innovative vessels experienced ship designers play an important role in organizing and structuring the design process. How this actually happens within projects that develop such large, complex and innovative vessels for a single client is not clear. This observation lead to a broad, initial research question as the starting point for further research. How are innovative, large and complex vessels deve...

Enhanced photoluminescence from single nitrogen-vacancy defects in nanodiamonds coated with phenol-ionic complexes

Science.gov (United States)

Bray, Kerem; Previdi, Rodolfo; Gibson, Brant C.; Shimoni, Olga; Aharonovich, Igor

2015-03-01

Fluorescent nanodiamonds are attracting major attention in the field of bio-sensing and bio-labeling. In this work we demonstrate a robust approach to achieve an encapsulation of individual nanodiamonds with phenol-ionic complexes that enhance the photoluminescence from single nitrogen vacancy (NV) centers. We show that single NV centres in the coated nanodiamonds also exhibit shorter lifetimes, opening another channel for high resolution sensing. We propose that the nanodiamond encapsulation reduces the non-radiative decay pathways of the NV color centers. Our results provide a versatile and assessable way to enhance photoluminescence from nanodiamond defects that can be used in a variety of sensing and imaging applications.Fluorescent nanodiamonds are attracting major attention in the field of bio-sensing and bio-labeling. In this work we demonstrate a robust approach to achieve an encapsulation of individual nanodiamonds with phenol-ionic complexes that enhance the photoluminescence from single nitrogen vacancy (NV) centers. We show that single NV centres in the coated nanodiamonds also exhibit shorter lifetimes, opening another channel for high resolution sensing. We propose that the nanodiamond encapsulation reduces the non-radiative decay pathways of the NV color centers. Our results provide a versatile and assessable way to enhance photoluminescence from nanodiamond defects that can be used in a variety of sensing and imaging applications. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr07510b

Understanding large multiprotein complexes: applying a multiple allosteric networks model to explain the function of the Mediator transcription complex.

Science.gov (United States)

Lewis, Brian A

2010-01-15

The regulation of transcription and of many other cellular processes involves large multi-subunit protein complexes. In the context of transcription, it is known that these complexes serve as regulatory platforms that connect activator DNA-binding proteins to a target promoter. However, there is still a lack of understanding regarding the function of these complexes. Why do multi-subunit complexes exist? What is the molecular basis of the function of their constituent subunits, and how are these subunits organized within a complex? What is the reason for physical connections between certain subunits and not others? In this article, I address these issues through a model of network allostery and its application to the eukaryotic RNA polymerase II Mediator transcription complex. The multiple allosteric networks model (MANM) suggests that protein complexes such as Mediator exist not only as physical but also as functional networks of interconnected proteins through which information is transferred from subunit to subunit by the propagation of an allosteric state known as conformational spread. Additionally, there are multiple distinct sub-networks within the Mediator complex that can be defined by their connections to different subunits; these sub-networks have discrete functions that are activated when specific subunits interact with other activator proteins.

The magnetic g-tensors for ion complexes with large spin-orbit coupling

International Nuclear Information System (INIS)

Chang, P.K.L.; Liu, Y.S.

1977-01-01

A nonperturbative method for calculating the magnetic g-tensors is presented and discussed for complexes of transition metal ions of large spin-orbit coupling, in the ground term 2 D. A numerical example for CuCl 2 .2H 2 O is given [pt

Valid knowledge for the professional design of large and complex design processes

NARCIS (Netherlands)

Aken, van J.E.

2004-01-01

The organization and planning of design processes, which we may regard as design process design, is an important issue. Especially for large and complex design-processes traditional approaches to process design may no longer suffice. The design literature gives quite some design process models. As

A multistep single-crystal-to-single-crystal bromodiacetylene dimerization

Science.gov (United States)

Hoheisel, Tobias N.; Schrettl, Stephen; Marty, Roman; Todorova, Tanya K.; Corminboeuf, Clémence; Sienkiewicz, Andrzej; Scopelliti, Rosario; Schweizer, W. Bernd; Frauenrath, Holger

2013-04-01

Packing constraints and precise placement of functional groups are the reason that organic molecules in the crystalline state often display unusual physical or chemical properties not observed in solution. Here we report a single-crystal-to-single-crystal dimerization of a bromodiacetylene that involves unusually large atom displacements as well as the cleavage and formation of several bonds. Density functional theory computations support a mechanism in which the dimerization is initiated by a [2 + 1] photocycloaddition favoured by the nature of carbon-carbon short contacts in the crystal structure. The reaction proceeded up to the theoretical degree of conversion without loss of crystallinity, and it was also performed on a preparative scale with good yield. Moreover, it represents the first synthetic pathway to (E)-1,2-dibromo-1,2-diethynylethenes, which could serve as synthetic intermediates for the preparation of molecular carbon scaffolds. Our findings both extend the scope of single-crystal-to-single-crystal reactions and highlight their potential as a synthetic tool for complex transformations.

Single channel recording of a mitochondrial calcium uniporter.

Science.gov (United States)

Wu, Guangyan; Li, Shunjin; Zong, Guangning; Liu, Xiaofen; Fei, Shuang; Shen, Linda; Guan, Xiangchen; Yang, Xue; Shen, Yuequan

2018-01-29

Mitochondrial calcium uniporter (MCU) is the pore-forming subunit of the entire uniporter complex and plays an important role in mitochondrial calcium uptake. However, the single channel recording of MCU remains controversial. Here, we expressed and purified different MCU proteins and then reconstituted them into planar lipid bilayers for single channel recording. We showed that MCU alone from Pyronema omphalodes (pMCU) is active with prominent single channel Ca 2+ currents. In sharp contrast, MCU alone from Homo sapiens (hMCU) is inactive. The essential MCU regulator (EMRE) activates hMCU, and therefore, the complex (hMCU-hEMRE) shows prominent single channel Ca 2+ currents. These single channel currents are sensitive to the specific MCU inhibitor Ruthenium Red. Our results clearly demonstrate that active MCU can conduct large amounts of calcium into the mitochondria. Copyright © 2018 Elsevier Inc. All rights reserved.

An introduction to complex systems society, ecology, and nonlinear dynamics

CERN Document Server

Fieguth, Paul

2017-01-01

This undergraduate text explores a variety of large-scale phenomena - global warming, ice ages, water, poverty - and uses these case studies as a motivation to explore nonlinear dynamics, power-law statistics, and complex systems. Although the detailed mathematical descriptions of these topics can be challenging, the consequences of a system being nonlinear, power-law, or complex are in fact quite accessible. This book blends a tutorial approach to the mathematical aspects of complex systems together with a complementary narrative on the global/ecological/societal implications of such systems. Nearly all engineering undergraduate courses focus on mathematics and systems which are small scale, linear, and Gaussian. Unfortunately there is not a single large-scale ecological or social phenomenon that is scalar, linear, and Gaussian. This book offers students insights to better understand the large-scale problems facing the world and to realize that these cannot be solved by a single, narrow academic field or per...

In Planta Single-Molecule Pull-Down Reveals Tetrameric Stoichiometry of HD-ZIPIII:LITTLE ZIPPER Complexes.

Science.gov (United States)

Husbands, Aman Y; Aggarwal, Vasudha; Ha, Taekjip; Timmermans, Marja C P

2016-08-01

Deciphering complex biological processes markedly benefits from approaches that directly assess the underlying biomolecular interactions. Most commonly used approaches to monitor protein-protein interactions typically provide nonquantitative readouts that lack statistical power and do not yield information on the heterogeneity or stoichiometry of protein complexes. Single-molecule pull-down (SiMPull) uses single-molecule fluorescence detection to mitigate these disadvantages and can quantitatively interrogate interactions between proteins and other compounds, such as nucleic acids, small molecule ligands, and lipids. Here, we establish SiMPull in plants using the HOMEODOMAIN LEUCINE ZIPPER III (HD-ZIPIII) and LITTLE ZIPPER (ZPR) interaction as proof-of-principle. Colocalization analysis of fluorophore-tagged HD-ZIPIII and ZPR proteins provides strong statistical evidence of complex formation. In addition, we use SiMPull to directly quantify YFP and mCherry maturation probabilities, showing these differ substantially from values obtained in mammalian systems. Leveraging these probabilities, in conjunction with fluorophore photobleaching assays on over 2000 individual complexes, we determined HD-ZIPIII:ZPR stoichiometry. Intriguingly, these complexes appear as heterotetramers, comprising two HD-ZIPIII and two ZPR molecules, rather than heterodimers as described in the current model. This surprising result raises new questions about the regulation of these key developmental factors and is illustrative of the unique contribution SiMPull is poised to make to in planta protein interaction studies. © 2016 American Society of Plant Biologists. All rights reserved.

Dye molecules as single-photon sources and large optical nonlinearities on a chip

International Nuclear Information System (INIS)

Hwang, J; Hinds, E A

2011-01-01

We point out that individual organic dye molecules, deposited close to optical waveguides on a photonic chip, can act as single-photon sources. A thin silicon nitride strip waveguide is expected to collect 28% of the photons from a single dibenzoterrylene molecule. These molecules can also provide large, localized optical nonlinearities, which are enough to discriminate between one photon or two through a differential phase shift of 2 0 per photon. This new atom-photon interface may be used as a resource for processing quantum information.

Lupus-related single nucleotide polymorphisms and risk of diffuse large B-cell lymphoma

NARCIS (Netherlands)

Bernatsky, Sasha; Velásquez García, Héctor A; Spinelli, John; Gaffney, Patrick; Smedby, Karin E; Ramsey-Goldman, Rosalind; Wang, Sophia S.; Adami, Hans-Olov; Albanes, Demetrius; Angelucci, Emanuele; Ansell, Stephen M.; Asmann, Yan W.; Becker, Nikolaus; Benavente, Yolanda; Berndt, Sonja I.; Bertrand, Kimberly A.; Birmann, Brenda M.; Boeing, Heiner; Boffetta, Paolo; Bracci, Paige M.; Brennan, Paul; Brooks-Wilson, Angela R.; Cerhan, James R.; Chanock, Stephen J.; Clavel, Jacqueline; Conde, Lucia; Cotenbader, Karen H; Cox, David G; Cozen, Wendy; Crouch, Simon; De Roos, Anneclaire J.; De Sanjose, Silvia; Di Lollo, Simonetta; Diver, W. Ryan; Dogan, Ahmet; Foretova, Lenka; Ghesquières, Hervé; Giles, Graham G.; Glimelius, Bengt; Habermann, Thomas M.; Haioun, Corinne; Hartge, Patricia; Hjalgrim, Henrik; Holford, Theodore R.; Holly, Elizabeth A.; Jackson, Rebecca D.; Kaaks, Rudolph; Kane, Eleanor; Kelly, Rachel S.; Klein, Robert J.; Kraft, Peter; Kricker, Anne; Lan, Qing; Lawrence, Charles; Liebow, Mark; Lightfoot, Tracy; Link, Brian K.; Maynadie, Marc; McKay, James; Melbye, Mads; Molina, Thierry Jo; Monnereau, Alain; Morton, Lindsay M.; Nieters, Alexandra; North, Kari E.; Novak, Anne J.; Offit, Kenneth; Purdue, Mark P.; Rais, Marco; Riby, Jacques; Roman, Eve; Rothman, Nathaniel; Salles, Gilles; Severi, Gianluca; Severson, Richard K.; Skibola, Christine F.; Slager, Susan L.; Smith, Alex; Smith, Martyn T.; Southey, Melissa C.; Staines, Anthony; Teras, Lauren R.; Thompson, Carrie A.; Tilly, Hervé; Tinker, Lesley F.; Tjonneland, Anne; Turner, Jenny; Vajdic, Claire M.; Vermeulen, Roel C H; Vijai, Joseph; Vineis, Paolo; Virtamo, Jarmo; Wang, Zhaoming; Weinstein, Stephanie; Witzig, Thomas E.; Zelenetz, Andrew; Zeleniuch-Jacquotte, Anne; Zhang, Yawei; Zheng, Tongzhang; Zucca, Mariagrazia; Clarke, Ann E

2017-01-01

Objective: Determinants of the increased risk of diffuse large B-cell lymphoma (DLBCL) in SLE are unclear. Using data from a recent lymphoma genome-wide association study (GWAS), we assessed whether certain lupus-related single nucleotide polymorphisms (SNPs) were also associated with DLBCL.

GRAMI: Frequent subgraph and pattern mining in a single large graph

KAUST Repository

Elseidy, M.

2014-01-01

Mining frequent subgraphs is an important operation on graphs; it is defined as finding all subgraphs that appear frequently in a database according to a given frequency threshold. Most existing work assumes a database of many small graphs, but modern applications, such as social networks, citation graphs, or proteinprotein interactions in bioinformatics, are modeled as a single large graph. In this paper we present GRAMI, a novel framework for frequent subgraph mining in a single large graph. GRAMI undertakes a novel approach that only finds the minimal set of instances to satisfy the frequency threshold and avoids the costly enumeration of all instances required by previous approaches. We accompany our approach with a heuristic and optimizations that significantly improve performance. Additionally, we present an extension of GRAMI that mines frequent patterns. Compared to subgraphs, patterns offer a more powerful version of matching that captures transitive interactions between graph nodes (like friend of a friend) which are very common in modern applications. Finally, we present CGRAMI, a version supporting structural and semantic constraints, and AGRAMI, an approximate version producing results with no false positives. Our experiments on real data demonstrate that our framework is up to 2 orders of magnitude faster and discovers more interesting patterns than existing approaches. 2014 VLDB Endowment.

Megacities and Large Urban Complexes - WMO Role in Addressing Challenges and Opportunities

Science.gov (United States)

Terblanche, Deon; Jalkanen, Liisa

2013-04-01

Megacities and Large Urban Complexes - WMO Role in Addressing Challenges and Opportunities Deon E. Terblanche and Liisa Jalkanen dterblanche@wmo.int ljalkanen@wmo.int World Meteorological Organization, Geneva, Switzerland The 21st Century could amongst others, become known as the century in which our species has evolved from Homo sapiens to Homo urbanus. By now the urban population has surpassed the rural population and the rate of urbanization will continue at such a pace that by 2050 urban dwellers could outnumber their rural counterpart by more than two to one. Most of this growth in urban population will occur in developing countries and along coastal areas. Urbanization is to a large extent the outcome of humans seeking a better life through improved opportunities presented by high-density communities. Megacities and large urban complexes provide more job opportunities and social structures, better transport and communication links and a relative abundance of physical goods and services when compared to most rural areas. Unfortunately these urban complexes also present numerous social and environmental challenges. Urban areas differ from their surroundings by morphology, population density, and with high concentration of industrial activities, energy consumption and transport. They also pose unique challenges to atmospheric modelling and monitoring and create a multi-disciplinary spectrum of potential threats, including air pollution, which need to be addressed in an integrated way. These areas are also vulnerable to the changing climate and its implications to sea-level and extreme events, air quality and related health impacts. Many urban activities are significantly impacted by weather events that would not be considered to be of high impact in less densely populated areas. For instance, moderate precipitation events can cause flooding and landslides as modified urban catchments generally have higher run-off to rainfall ratios than their more pristine rural

Hierarchical modeling and robust synthesis for the preliminary design of large scale complex systems

Science.gov (United States)

Koch, Patrick Nathan

Large-scale complex systems are characterized by multiple interacting subsystems and the analysis of multiple disciplines. The design and development of such systems inevitably requires the resolution of multiple conflicting objectives. The size of complex systems, however, prohibits the development of comprehensive system models, and thus these systems must be partitioned into their constituent parts. Because simultaneous solution of individual subsystem models is often not manageable iteration is inevitable and often excessive. In this dissertation these issues are addressed through the development of a method for hierarchical robust preliminary design exploration to facilitate concurrent system and subsystem design exploration, for the concurrent generation of robust system and subsystem specifications for the preliminary design of multi-level, multi-objective, large-scale complex systems. This method is developed through the integration and expansion of current design techniques: (1) Hierarchical partitioning and modeling techniques for partitioning large-scale complex systems into more tractable parts, and allowing integration of subproblems for system synthesis, (2) Statistical experimentation and approximation techniques for increasing both the efficiency and the comprehensiveness of preliminary design exploration, and (3) Noise modeling techniques for implementing robust preliminary design when approximate models are employed. The method developed and associated approaches are illustrated through their application to the preliminary design of a commercial turbofan turbine propulsion system; the turbofan system-level problem is partitioned into engine cycle and configuration design and a compressor module is integrated for more detailed subsystem-level design exploration, improving system evaluation.

Edge field emission of large-area single layer graphene

Energy Technology Data Exchange (ETDEWEB)

Kleshch, Victor I., E-mail: klesch@polly.phys.msu.ru [Department of Physics, M.V. Lomonosov Moscow State University, Moscow 119991 (Russian Federation); Bandurin, Denis A. [Department of Physics, M.V. Lomonosov Moscow State University, Moscow 119991 (Russian Federation); Orekhov, Anton S. [Department of Physics, M.V. Lomonosov Moscow State University, Moscow 119991 (Russian Federation); A.V. Shubnikov Institute of Crystallography, RAS, Moscow 119333 (Russian Federation); Purcell, Stephen T. [ILM, Université Claude Bernard Lyon 1 et CNRS, UMR 5586, 69622 Villeurbanne (France); Obraztsov, Alexander N. [Department of Physics, M.V. Lomonosov Moscow State University, Moscow 119991 (Russian Federation); Department of Physics and Mathematics, University of Eastern Finland, Joensuu 80101 (Finland)

2015-12-01

Graphical abstract: - Highlights: • Stable field emission was observed from the edge of large-area graphene on quartz. • A strong hysteresis in current–voltage characteristics was observed. • The hysteresis was explained by mechanical peeling of graphene edge from substrate. • Reversible peeling of graphene edge may be used in microelectromechanical systems. - Abstract: Field electron emission from the edges of large-area (∼1 cm × 1 cm) graphene films deposited onto quartz wafers was studied. The graphene was previously grown by chemical vapour deposition on copper. An extreme enhancement of electrostatic field at the edge of the films with macroscopically large lateral dimensions and with single atom thickness was achieved. This resulted in the creation of a blade type electron emitter, providing stable field emission at low-voltage with linear current density up to 0.5 mA/cm. A strong hysteresis in current–voltage characteristics and a step-like increase of the emission current during voltage ramp up were observed. These effects were explained by the local mechanical peeling of the graphene edge from the quartz substrate by the ponderomotive force during the field emission process. Specific field emission phenomena exhibited in the experimental study are explained by a unique combination of structural, electronic and mechanical properties of graphene. Various potential applications ranging from linear electron beam sources to microelectromechanical systems are discussed.

Does reef architectural complexity influence resource availability for a large reef-dwelling invertebrate?

Science.gov (United States)

Lozano-Álvarez, Enrique; Luviano-Aparicio, Nelia; Negrete-Soto, Fernando; Barradas-Ortiz, Cecilia; Aguíñiga-García, Sergio; Morillo-Velarde, Piedad S.; Álvarez-Filip, Lorenzo; Briones-Fourzán, Patricia

2017-10-01

In coral reefs, loss of architectural complexity and its associated habitat degradation is expected to affect reef specialists in particular due to changes in resource availability. We explored whether these features could potentially affect populations of a large invertebrate, the spotted spiny lobster Panulirus guttatus, which is an obligate Caribbean coral reef-dweller with a limited home range. We selected two separate large coral reef patches in Puerto Morelos (Mexico) that differed significantly in structural complexity and level of degradation, as assessed via the rugosity index, habitat assessment score, and percent cover of various benthic components. On each reef, we estimated density of P. guttatus and sampled lobsters to analyze their stomach contents, three different condition indices, and stable isotopes (δ15N and δ13C) in muscle. Lobster density did not vary with reef, suggesting that available crevices in the less complex patch still provided adequate refuge to these lobsters. Lobsters consumed many food types, dominated by mollusks and crustaceans, but proportionally more crustaceans (herbivore crabs) in the less complex patch, which had more calcareous macroalgae and algal turf. Lobsters from both reefs had a similar condition (all three indices) and mean δ15N, suggesting a similar quality of diet between reefs related to their opportunistic feeding, but differed in mean δ13C values, reflecting the different carbon sources between reefs and providing indirect evidence of individuals of P. guttatus foraging exclusively over their home reef. Overall, we found no apparent effects of architectural complexity, at least to the degree observed in our less complex patch, on density, condition, or trophic level of P. guttatus.

Low-Complexity Model Predictive Control of Single-Phase Three-Level Rectifiers with Unbalanced Load

DEFF Research Database (Denmark)

Ma, Junpeng; Song, Wensheng; Wang, Xiongfei

2018-01-01

The fluctuation of the neutral-point potential in single-phase three-level rectifiers leads to coupling between the line current regulation and dc-link voltage balancing, deteriorating the quality of line current. For addressing this issue, this paper proposes a low-complexity model predictive...

Measuring kinetics of complex single ion channel data using mean-variance histograms.

Science.gov (United States)

Patlak, J B

1993-07-01

The measurement of single ion channel kinetics is difficult when those channels exhibit subconductance events. When the kinetics are fast, and when the current magnitudes are small, as is the case for Na+, Ca2+, and some K+ channels, these difficulties can lead to serious errors in the estimation of channel kinetics. I present here a method, based on the construction and analysis of mean-variance histograms, that can overcome these problems. A mean-variance histogram is constructed by calculating the mean current and the current variance within a brief "window" (a set of N consecutive data samples) superimposed on the digitized raw channel data. Systematic movement of this window over the data produces large numbers of mean-variance pairs which can be assembled into a two-dimensional histogram. Defined current levels (open, closed, or sublevel) appear in such plots as low variance regions. The total number of events in such low variance regions is estimated by curve fitting and plotted as a function of window width. This function decreases with the same time constants as the original dwell time probability distribution for each of the regions. The method can therefore be used: 1) to present a qualitative summary of the single channel data from which the signal-to-noise ratio, open channel noise, steadiness of the baseline, and number of conductance levels can be quickly determined; 2) to quantify the dwell time distribution in each of the levels exhibited. In this paper I present the analysis of a Na+ channel recording that had a number of complexities. The signal-to-noise ratio was only about 8 for the main open state, open channel noise, and fast flickers to other states were present, as were a substantial number of subconductance states. "Standard" half-amplitude threshold analysis of these data produce open and closed time histograms that were well fitted by the sum of two exponentials, but with apparently erroneous time constants, whereas the mean

Single-mode regime in large-mode-area rare-earth-doped rod-type PCFs

DEFF Research Database (Denmark)

Poli, F.; Cucinotta, A.; Passaro, D.

2009-01-01

In this paper, large-mode-area, double-cladding, rare-earth-doped photonic crystal fibers are investigated in order to understand how the refractive index distribution and the mode competition given by the amplification can assure single-mode propagation. Fibers with different core diameters, i...

Detailed Investigation of the Structural, Thermal, and Electronic Properties of Gold Isocyanide Complexes with Mechano-Triggered Single-Crystal-to-Single-Crystal Phase Transitions.

Science.gov (United States)

Seki, Tomohiro; Sakurada, Kenta; Muromoto, Mai; Seki, Shu; Ito, Hajime

2016-02-01

Mechano-induced phase transitions in organic crystalline materials, which can alter their properties, have received much attention. However, most mechano-responsive molecular crystals exhibit crystal-to-amorphous phase transitions, and the intermolecular interaction patterns in the daughter phase are difficult to characterize. We have investigated phenyl(phenylisocyanide)gold(I) (1) and phenyl(3,5-dimethylphenylisocyanide)gold(I) (2) complexes, which exhibit a mechano-triggered single-crystal-to-single-crystal phase transition. Previous reports of complexes 1 and 2 have focused on the relationships between the crystalline structures and photoluminescence properties; in this work we have focused on other aspects. The face index measurements of complexes 1 and 2 before and after the mechano-induced phase transitions have indicated that they undergo non-epitaxial phase transitions without a rigorous orientational relationship between the mother and daughter phases. Differential scanning calorimetry analyses revealed the phase transition of complex 1 to be enthalpically driven by the formation of new aurophilic interactions. In contrast, the phase transition of complex 2 was found to be entropically driven, with the closure of an empty void in the mother phase. Scanning electron microscopy observation showed that the degree of the charging effect of both complexes 1 and 2 was changed by the phase transitions, which suggests that the formation of the aurophilic interactions affords more effective conductive pathways. Moreover, flash-photolysis time-resolved microwave conductivity measurements revealed that complex 1 increased in conductivity after the phase change, whereas the conductivity of complex 2 decreased. These contrasting results were explained by the different patterns in the aurophilic interactions. Finally, an intriguing disappearing polymorphism of complex 2 has been reported, in which a polymorph form could not be obtained again after some period of time

LEGO-NMR spectroscopy: a method to visualize individual subunits in large heteromeric complexes.

Science.gov (United States)

Mund, Markus; Overbeck, Jan H; Ullmann, Janina; Sprangers, Remco

2013-10-18

Seeing the big picture: Asymmetric macromolecular complexes that are NMR active in only a subset of their subunits can be prepared, thus decreasing NMR spectral complexity. For the hetero heptameric LSm1-7 and LSm2-8 rings NMR spectra of the individual subunits of the complete complex are obtained, showing a conserved RNA binding site. This LEGO-NMR technique makes large asymmetric complexes accessible to detailed NMR spectroscopic studies. © 2013 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA. This is an open access article under the terms of Creative Commons the Attribution Non-Commercial NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

Synthesis and Characterization of Hexahapto-Chromium Complexes of Single-Walled Carbon Nanotubes

KAUST Repository

Kalinina, Irina

2016-12-17

This chapter employs purified pristine single-walled carbon nanotubes (SWNTs) and octadecylaminefunctionalized-SWNTs. These SWNTs are employed for investigate the potential of the SWNT sidewall to function as a hexahapto ligand for chromium (Cr), with in-depth characterization of the products using some of the techniques, such as thermogravimetric analysis (TGA), transmission electron microscopy (TEM), x-ray photoelectron spectroscopy (XPS). Purified electric arc (EA)-produced SWNTs (P2-SWNT) and octadecylaminefunctionalized SWNTs were obtained from Carbon Solutions, Inc. The TEM images show the removal of the Cr particles from the outer surface of the SWNT bundles in the SWNT-Cr complexes after decomplexation; Cr attachment to the surface of the as-prepared complexes (η6-SWNT)Cr(CO)3 and (η6-SWNT-CONH(CH2)17CH3)Cr(CO)3 is clearly evident. The positions of the bands in the Raman spectra of SWNTs are sensitive to doping and thus the chapter examines the effect of complexation of the Cr(CO)3 and Cr(η6-benzene) units on the position of the G and 2D bands in the (η6-SWNT)Cr(CO)3 and (η6-SWNT)Cr(η6-benzene) complexes.

Large curvature and background scale independence in single-metric approximations to asymptotic safety

Energy Technology Data Exchange (ETDEWEB)

Morris, Tim R. [STAG Research Centre & Department of Physics and Astronomy, University of Southampton,Highfield, Southampton, SO17 1BJ (United Kingdom)

2016-11-25

In single-metric approximations to the exact renormalization group (RG) for quantum gravity, it has been not been clear how to treat the large curvature domain beyond the point where the effective cutoff scale k is less than the lowest eigenvalue of the appropriate modified Laplacian. We explain why this puzzle arises from background dependence, resulting in Wilsonian RG concepts being inapplicable. We show that when properly formulated over an ensemble of backgrounds, the Wilsonian RG can be restored. This in turn implies that solutions should be smooth and well defined no matter how large the curvature is taken. Even for the standard single-metric type approximation schemes, this construction can be rigorously derived by imposing a modified Ward identity (mWI) corresponding to rescaling the background metric by a constant factor. However compatibility in this approximation requires the space-time dimension to be six. Solving the mWI and flow equation simultaneously, new variables are then derived that are independent of overall background scale.

Design of a Large Single-Aperture Dipole Magnet for HL-LHC Upgrade

CERN Document Server

Qingjin, Xu; Iio, Masami; Ogitsu, Toru; Sasaki, Kenichi; Yamamoto, Akira; Todesco, Ezio

2013-01-01

An upgrade of the low-beta insertion system for the ATLAS and Compact Muon Solenoid experiments is proposed in the high luminosity Large Hadron Collider upgrade project. It includes final beam focusing quadrupoles, beam separation and recombination dipoles, and larger aperture matching section quadrupoles. KEK is in charge of the conceptual design of the large aperture separation dipole D1. The latest design parameters are a main field of ~ 5 T at 1.9 K with Nb-Ti superconducting technology, a coil aperture of 160 mm, and a cos-theta one-layer coil with Large Hadron Collider dipole cable. Because the new D1 is expected to be operated in a very high radiation environment, radiation resistance and a cooling scheme are being carefully considered. The collaring-yoke structure is adopted to provide the mechanical support for the single-layer Nb-Ti coil. We summarize the design study of this magnet, including i) the very large iron saturation effect on field quality due to the large aperture and limited size of the...

Polynomial expansion of the precoder for power minimization in large-scale MIMO systems

KAUST Repository

Sifaou, Houssem

2016-07-26

This work focuses on the downlink of a single-cell large-scale MIMO system in which the base station equipped with M antennas serves K single-antenna users. In particular, we are interested in reducing the implementation complexity of the optimal linear precoder (OLP) that minimizes the total power consumption while ensuring target user rates. As most precoding schemes, a major difficulty towards the implementation of OLP is that it requires fast inversions of large matrices at every new channel realizations. To overcome this issue, we aim at designing a linear precoding scheme providing the same performance of OLP but with lower complexity. This is achieved by applying the truncated polynomial expansion (TPE) concept on a per-user basis. To get a further leap in complexity reduction and allow for closed-form expressions of the per-user weighting coefficients, we resort to the asymptotic regime in which M and K grow large with a bounded ratio. Numerical results are used to show that the proposed TPE precoding scheme achieves the same performance of OLP with a significantly lower implementation complexity. © 2016 IEEE.

Resolving dual binding conformations of cellulosome cohesin-dockerin complexes using single-molecule force spectroscopy.

Science.gov (United States)

Jobst, Markus A; Milles, Lukas F; Schoeler, Constantin; Ott, Wolfgang; Fried, Daniel B; Bayer, Edward A; Gaub, Hermann E; Nash, Michael A

2015-10-31

Receptor-ligand pairs are ordinarily thought to interact through a lock and key mechanism, where a unique molecular conformation is formed upon binding. Contrary to this paradigm, cellulosomal cohesin-dockerin (Coh-Doc) pairs are believed to interact through redundant dual binding modes consisting of two distinct conformations. Here, we combined site-directed mutagenesis and single-molecule force spectroscopy (SMFS) to study the unbinding of Coh:Doc complexes under force. We designed Doc mutations to knock out each binding mode, and compared their single-molecule unfolding patterns as they were dissociated from Coh using an atomic force microscope (AFM) cantilever. Although average bulk measurements were unable to resolve the differences in Doc binding modes due to the similarity of the interactions, with a single-molecule method we were able to discriminate the two modes based on distinct differences in their mechanical properties. We conclude that under native conditions wild-type Doc from Clostridium thermocellum exocellulase Cel48S populates both binding modes with similar probabilities. Given the vast number of Doc domains with predicted dual binding modes across multiple bacterial species, our approach opens up new possibilities for understanding assembly and catalytic properties of a broad range of multi-enzyme complexes.

Quantifying the Assembly of Multicomponent Molecular Machines by Single-Molecule Total Internal Reflection Fluorescence Microscopy.

Science.gov (United States)

Boehm, E M; Subramanyam, S; Ghoneim, M; Washington, M Todd; Spies, M

2016-01-01

Large, dynamic macromolecular complexes play essential roles in many cellular processes. Knowing how the components of these complexes associate with one another and undergo structural rearrangements is critical to understanding how they function. Single-molecule total internal reflection fluorescence (TIRF) microscopy is a powerful approach for addressing these fundamental issues. In this article, we first discuss single-molecule TIRF microscopes and strategies to immobilize and fluorescently label macromolecules. We then review the use of single-molecule TIRF microscopy to study the formation of binary macromolecular complexes using one-color imaging and inhibitors. We conclude with a discussion of the use of TIRF microscopy to examine the formation of higher-order (i.e., ternary) complexes using multicolor setups. The focus throughout this article is on experimental design, controls, data acquisition, and data analysis. We hope that single-molecule TIRF microscopy, which has largely been the province of specialists, will soon become as common in the tool box of biophysicists and biochemists as structural approaches have become today. © 2016 Elsevier Inc. All rights reserved.

Knowledge Sharing Strategies for Large Complex Building Projects.

Directory of Open Access Journals (Sweden)

Esra Bektas

2013-06-01

Full Text Available The construction industry is a project-based sector with a myriad of actors such as architects, construction companies, consultants, producers of building materials (Anumba et al., 2005. The interaction between the project partners is often quite limited, which leads to insufficient knowledge sharing during the project and knowledge being unavailable for reuse (Fruchter et al. 2002. The result can be a considerable amount of extra work, delays and cost overruns. Design outcomes that are supposed to function as boundary objects across different disciplines can lead to misinterpretation of requirements, project content and objectives. In this research, knowledge is seen as resulting from social interactions; knowledge resides in communities and it is generated through social relationships (Wenger 1998, Olsson et al. 2008. Knowledge is often tacit, intangible and context-dependent and it is articulated in the changing responsibilities, roles, attitudes and values that are present in the work environment (Bresnen et al., 2003. In a project environment, knowledge enables individuals to solve problems, take decisions, and apply these decisions to actions. In order to achieve a shared understanding and minimize the misunderstanding and misinterpretations among project actors, it is necessary to share knowledge (Fong 2003. Sharing knowledge is particularly crucial in large complex building projects (LCBPs in order to accelerate the building process, improve architectural quality and prevent mistakes or undesirable results. However, knowledge sharing is often hampered through professional or organizational boundaries or contractual concerns. When knowledge is seen as an organizational asset, there is little willingness among project organizations to share their knowledge. Individual people may recognize the need to promote knowledge sharing throughout the project, but typically there is no deliberate strategy agreed by all project partners to address

Comparative Performance in Single-Port Versus Multiport Minimally Invasive Surgery, and Small Versus Large Operative Working Spaces: A Preclinical Randomized Crossover Trial.

Science.gov (United States)

Marcus, Hani J; Seneci, Carlo A; Hughes-Hallett, Archie; Cundy, Thomas P; Nandi, Dipankar; Yang, Guang-Zhong; Darzi, Ara

2016-04-01

Surgical approaches such as transanal endoscopic microsurgery, which utilize small operative working spaces, and are necessarily single-port, are particularly demanding with standard instruments and have not been widely adopted. The aim of this study was to compare simultaneously surgical performance in single-port versus multiport approaches, and small versus large working spaces. Ten novice, 4 intermediate, and 1 expert surgeons were recruited from a university hospital. A preclinical randomized crossover study design was implemented, comparing performance under the following conditions: (1) multiport approach and large working space, (2) multiport approach and intermediate working space, (3) single-port approach and large working space, (4) single-port approach and intermediate working space, and (5) single-port approach and small working space. In each case, participants performed a peg transfer and pattern cutting tasks, and each task repetition was scored. Intermediate and expert surgeons performed significantly better than novices in all conditions (P Performance in single-port surgery was significantly worse than multiport surgery (P performance in the intermediate versus large working space. In single-port surgery, there was a converse trend; performances in the intermediate and small working spaces were significantly better than in the large working space. Single-port approaches were significantly more technically challenging than multiport approaches, possibly reflecting loss of instrument triangulation. Surprisingly, in single-port approaches, in which triangulation was no longer a factor, performance in large working spaces was worse than in intermediate and small working spaces. © The Author(s) 2015.

Techniques for extracting single-trial activity patterns from large-scale neural recordings

Science.gov (United States)

Churchland, Mark M; Yu, Byron M; Sahani, Maneesh; Shenoy, Krishna V

2008-01-01

Summary Large, chronically-implanted arrays of microelectrodes are an increasingly common tool for recording from primate cortex, and can provide extracellular recordings from many (order of 100) neurons. While the desire for cortically-based motor prostheses has helped drive their development, such arrays also offer great potential to advance basic neuroscience research. Here we discuss the utility of array recording for the study of neural dynamics. Neural activity often has dynamics beyond that driven directly by the stimulus. While governed by those dynamics, neural responses may nevertheless unfold differently for nominally identical trials, rendering many traditional analysis methods ineffective. We review recent studies – some employing simultaneous recording, some not – indicating that such variability is indeed present both during movement generation, and during the preceding premotor computations. In such cases, large-scale simultaneous recordings have the potential to provide an unprecedented view of neural dynamics at the level of single trials. However, this enterprise will depend not only on techniques for simultaneous recording, but also on the use and further development of analysis techniques that can appropriately reduce the dimensionality of the data, and allow visualization of single-trial neural behavior. PMID:18093826

Design of an omnidirectional single-point photodetector for large-scale spatial coordinate measurement

Science.gov (United States)

Xie, Hongbo; Mao, Chensheng; Ren, Yongjie; Zhu, Jigui; Wang, Chao; Yang, Lei

2017-10-01

In high precision and large-scale coordinate measurement, one commonly used approach to determine the coordinate of a target point is utilizing the spatial trigonometric relationships between multiple laser transmitter stations and the target point. A light receiving device at the target point is the key element in large-scale coordinate measurement systems. To ensure high-resolution and highly sensitive spatial coordinate measurement, a high-performance and miniaturized omnidirectional single-point photodetector (OSPD) is greatly desired. We report one design of OSPD using an aspheric lens, which achieves an enhanced reception angle of -5 deg to 45 deg in vertical and 360 deg in horizontal. As the heart of our OSPD, the aspheric lens is designed in a geometric model and optimized by LightTools Software, which enables the reflection of a wide-angle incident light beam into the single-point photodiode. The performance of home-made OSPD is characterized with working distances from 1 to 13 m and further analyzed utilizing developed a geometric model. The experimental and analytic results verify that our device is highly suitable for large-scale coordinate metrology. The developed device also holds great potential in various applications such as omnidirectional vision sensor, indoor global positioning system, and optical wireless communication systems.

Properties and modeling of GWAS when complex disease risk is due to non-complementing, deleterious mutations in genes of large effect.

Directory of Open Access Journals (Sweden)

Kevin R Thornton

Full Text Available Current genome-wide association studies (GWAS have high power to detect intermediate frequency SNPs making modest contributions to complex disease, but they are underpowered to detect rare alleles of large effect (RALE. This has led to speculation that the bulk of variation for most complex diseases is due to RALE. One concern with existing models of RALE is that they do not make explicit assumptions about the evolution of a phenotype and its molecular basis. Rather, much of the existing literature relies on arbitrary mapping of phenotypes onto genotypes obtained either from standard population-genetic simulation tools or from non-genetic models. We introduce a novel simulation of a 100-kilobase gene region, based on the standard definition of a gene, in which mutations are unconditionally deleterious, are continuously arising, have partially recessive and non-complementing effects on phenotype (analogous to what is widely observed for most Mendelian disorders, and are interspersed with neutral markers that can be genotyped. Genes evolving according to this model exhibit a characteristic GWAS signature consisting of an excess of marginally significant markers. Existing tests for an excess burden of rare alleles in cases have low power while a simple new statistic has high power to identify disease genes evolving under our model. The structure of linkage disequilibrium between causative mutations and significantly associated markers under our model differs fundamentally from that seen when rare causative markers are assumed to be neutral. Rather than tagging single haplotypes bearing a large number of rare causative alleles, we find that significant SNPs in a GWAS tend to tag single causative mutations of small effect relative to other mutations in the same gene. Our results emphasize the importance of evaluating the power to detect associations under models that are genetically and evolutionarily motivated.

Large Complex Odontoma of Mandible in a Young Boy: A Rare and Unusual Case Report

Directory of Open Access Journals (Sweden)

G. Siva Prasad Reddy

2014-01-01

Full Text Available Odontomas are the most common odontogenic tumors. They are broadly classified in to Compound Odontoma and Complex Odontoma. Among them complex odontoma is a rare tumor. Occasionally this tumor becomes large, causing expansion of bone followed by facial asymmetry. Otherwise these tumors are asymptomatic and are generally diagnosed on radiographic examination. We report a rare case of complex odontoma of mandible in a young boy. The tumor was treated by surgical excision under general anesthesia.

Cleavage and formation of molecular dinitrogen in a single system assisted by molybdenum complexes bearing ferrocenyldiphosphine.

Science.gov (United States)

Miyazaki, Takamasa; Tanaka, Hiromasa; Tanabe, Yoshiaki; Yuki, Masahiro; Nakajima, Kazunari; Yoshizawa, Kazunari; Nishibayashi, Yoshiaki

2014-10-20

The N≡N bond of molecular dinitrogen bridging two molybdenum atoms in the pentamethylcyclopentadienyl molybdenum complexes that bear ferrocenyldiphosphine as an auxiliary ligand is homolytically cleaved under visible light irradiation at room temperature to afford two molar molybdenum nitride complexes. Conversely, the bridging molecular dinitrogen is reformed by the oxidation of the molybdenum nitride complex at room temperature. This result provides a successful example of the cleavage and formation of molecular dinitrogen induced by a pair of two different external stimuli using a single system assisted by molybdenum complexes bearing ferrocenyldiphosphine under ambient conditions. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Lower extremity fatigue increases complexity of postural control during a single-legged stance

Directory of Open Access Journals (Sweden)

Bailey Jerry J

2011-08-01

Full Text Available Abstract Background Non-linear approaches to assessment of postural control can provide insight that compliment linear approaches. Control entropy (CE is a recently developed statistical tool from non-linear dynamical systems used to assess the complexity of non-stationary signals. We have previously used CE of high resolution accelerometry in running to show decreased complexity with exhaustive exercise. The purpose of this study was to determine if complexity of postural control decreases following fatiguing exercise using CE. Methods Ten subjects (5 M/5 F; 25 ± 3 yr; 169.4 ± 11.7 cm; 79.0 ± 16.9 kg consented to participation approved by Western Oregon University IRB and completed two trials separated by 2-7 days. Trials consisted of two single-legged balance tests separated by two Wingate anaerobic tests (WAnT; PreFat/PostFat, or rest period (PreRest/PostRest. Balance tests consisted of a series of five single-legged stances, separated by 30 s rest, performed while standing on the dominant leg for 15-s with the participant crossing the arms over the chest and flexing the non-dominant knee to 90 degrees. High resolution accelerometers (HRA were fixed superficial to L3/L4 at the approximate center of mass (COM. Triaxial signals from the HRA were streamed in real time at 625 Hz. COM accelerations were recorded in g's for vertical (VT, medial/lateral (ML, and anterior/posterior (AP axes. A newly developed statistic (R-test was applied to group response shapes generated by Karhunen Loeve (KL transform modes resulting from Control Entropy (CE analysis. Results R-tests showed a significant mean vector difference (p p p p Conclusions These data indicate that fatiguing exercise eliminates the differential complexity response between axes, but increases complexity in all axes compared to the non-fatigued condition. This has implications with regard to the effects of fatigue on strategies of the control system to maintain postural control.

Solution coating of large-area organic semiconductor thin films with aligned single-crystalline domains

KAUST Repository

Diao, Ying

2013-06-02

Solution coating of organic semiconductors offers great potential for achieving low-cost manufacturing of large-area and flexible electronics. However, the rapid coating speed needed for industrial-scale production poses challenges to the control of thin-film morphology. Here, we report an approach - termed fluid-enhanced crystal engineering (FLUENCE) - that allows for a high degree of morphological control of solution-printed thin films. We designed a micropillar-patterned printing blade to induce recirculation in the ink for enhancing crystal growth, and engineered the curvature of the ink meniscus to control crystal nucleation. Using FLUENCE, we demonstrate the fast coating and patterning of millimetre-wide, centimetre-long, highly aligned single-crystalline organic semiconductor thin films. In particular, we fabricated thin films of 6,13-bis(triisopropylsilylethynyl) pentacene having non-equilibrium single-crystalline domains and an unprecedented average and maximum mobilities of 8.1±1.2 cm2 V-1 s -1 and 11 cm2 V-1 s-1. FLUENCE of organic semiconductors with non-equilibrium single-crystalline domains may find use in the fabrication of high-performance, large-area printed electronics. © 2013 Macmillan Publishers Limited. All rights reserved.

Reorganizing Complex Network to Improve Large-Scale Multiagent Teamwork

Directory of Open Access Journals (Sweden)

Yang Xu

2014-01-01

Full Text Available Large-scale multiagent teamwork has been popular in various domains. Similar to human society infrastructure, agents only coordinate with some of the others, with a peer-to-peer complex network structure. Their organization has been proven as a key factor to influence their performance. To expedite team performance, we have analyzed that there are three key factors. First, complex network effects may be able to promote team performance. Second, coordination interactions coming from their sources are always trying to be routed to capable agents. Although they could be transferred across the network via different paths, their sources and sinks depend on the intrinsic nature of the team which is irrelevant to the network connections. In addition, the agents involved in the same plan often form a subteam and communicate with each other more frequently. Therefore, if the interactions between agents can be statistically recorded, we are able to set up an integrated network adjustment algorithm by combining the three key factors. Based on our abstracted teamwork simulations and the coordination statistics, we implemented the adaptive reorganization algorithm. The experimental results briefly support our design that the reorganized network is more capable of coordinating heterogeneous agents.

Some thoughts on the management of large, complex international space ventures

Science.gov (United States)

Lee, T. J.; Kutzer, Ants; Schneider, W. C.

1992-01-01

Management issues relevant to the development and deployment of large international space ventures are discussed with particular attention given to previous experience. Management approaches utilized in the past are labeled as either simple or complex, and signs of efficient management are examined. Simple approaches include those in which experiments and subsystems are developed for integration into spacecraft, and the Apollo-Soyuz Test Project is given as an example of a simple multinational approach. Complex approaches include those for ESA's Spacelab Project and the Space Station Freedom in which functional interfaces cross agency and political boundaries. It is concluded that individual elements of space programs should be managed by individual participating agencies, and overall configuration control is coordinated by level with a program director acting to manage overall objectives and project interfaces.

Geophysical mapping of complex glaciogenic large-scale structures

DEFF Research Database (Denmark)

Høyer, Anne-Sophie

2013-01-01

This thesis presents the main results of a four year PhD study concerning the use of geophysical data in geological mapping. The study is related to the Geocenter project, “KOMPLEKS”, which focuses on the mapping of complex, large-scale geological structures. The study area is approximately 100 km2...... data types and co-interpret them in order to improve our geological understanding. However, in order to perform this successfully, methodological considerations are necessary. For instance, a structure indicated by a reflection in the seismic data is not always apparent in the resistivity data...... information) can be collected. The geophysical data are used together with geological analyses from boreholes and pits to interpret the geological history of the hill-island. The geophysical data reveal that the glaciotectonic structures truncate at the surface. The directions of the structures were mapped...

Surgical Treatment of a Large Complex Odontoma

Directory of Open Access Journals (Sweden)

Burak Cezairli

2017-08-01

Full Text Available The treatment modalities for odontomas are generally depend on the tumors size. Small and medium lesions can usually be removed easily allowing preservation of surrounding anatomical structures. In our study, we reported a conservative surgical treatment of a large complex odontoma. A 19-year-old woman was referred to our clinic after an incidentally observed lesion on her right mandibular angle. The patient was symptom-free at the time of visit. Computed tomography (CT images showed a mass with a size of 3.5 cm x 3 cm x 2 cm. CT sections and tridimensional images showed partially eroded buccal and lingual cortex. Surgical treatment was indicated with an initial diagnosis of compound odontoma. The lesion removed after sectioning with bur and maxillo-mandibular fixation (MMF were not thought to be necessary while the buccal and lingual cortexes were mostly reliable for preventing a fracture. In our case, the size of the odontoma was suitable for a conservative treatment method and with this modality we managed to prevent a possible fracture and eliminate the disadvantages of MMF.

Tunable complex-valued multi-tap microwave photonic filter based on single silicon-oninsulator microring resonator

DEFF Research Database (Denmark)

Lloret, Juan; Sancho, Juan; Pu, Minhao

2011-01-01

A complex-valued multi-tap tunable microwave photonic filter based on single silicon-on-insulator microring resonator is presented. The degree of tunability of the approach involving two, three and four taps is theoretical and experimentally characterized, respectively. The constraints of exploit...

Statistical Methods for Single-Particle Electron Cryomicroscopy

DEFF Research Database (Denmark)

Jensen, Katrine Hommelhoff

Electron cryomicroscopy (cryo-EM) is a form of transmission electron microscopy, aimed at reconstructing the 3D structure of a macromolecular complex from a large set of 2D projection images, as they exhibit a very low signal-to-noise ratio (SNR). In the single-particle reconstruction (SPR) probl...

Complex Formation Control of Large-Scale Intelligent Autonomous Vehicles

Directory of Open Access Journals (Sweden)

Ming Lei

2012-01-01

Full Text Available A new formation framework of large-scale intelligent autonomous vehicles is developed, which can realize complex formations while reducing data exchange. Using the proposed hierarchy formation method and the automatic dividing algorithm, vehicles are automatically divided into leaders and followers by exchanging information via wireless network at initial time. Then, leaders form formation geometric shape by global formation information and followers track their own virtual leaders to form line formation by local information. The formation control laws of leaders and followers are designed based on consensus algorithms. Moreover, collision-avoiding problems are considered and solved using artificial potential functions. Finally, a simulation example that consists of 25 vehicles shows the effectiveness of theory.

Large-scale modelling of neuronal systems

International Nuclear Information System (INIS)

Castellani, G.; Verondini, E.; Giampieri, E.; Bersani, F.; Remondini, D.; Milanesi, L.; Zironi, I.

2009-01-01

The brain is, without any doubt, the most, complex system of the human body. Its complexity is also due to the extremely high number of neurons, as well as the huge number of synapses connecting them. Each neuron is capable to perform complex tasks, like learning and memorizing a large class of patterns. The simulation of large neuronal systems is challenging for both technological and computational reasons, and can open new perspectives for the comprehension of brain functioning. A well-known and widely accepted model of bidirectional synaptic plasticity, the BCM model, is stated by a differential equation approach based on bistability and selectivity properties. We have modified the BCM model extending it from a single-neuron to a whole-network model. This new model is capable to generate interesting network topologies starting from a small number of local parameters, describing the interaction between incoming and outgoing links from each neuron. We have characterized this model in terms of complex network theory, showing how this, learning rule can be a support For network generation.

Large linear magnetoresistance and shubnikov-de hass oscillations in single crystals of YPdBi heusler topological insulators

KAUST Repository

Wang, Wenhong; Du, Yin; Xu, Guizhou; Zhang, Xiaoming; Liu, Enke; Liu, Zhongyuan; Shi, Youguo; Chen, Jinglan; Wu, Guangheng; Zhang, Xixiang

2013-01-01

We report the observation of a large linear magnetoresistance (MR) and Shubnikov-de Hass (SdH) quantum oscillations in single crystals of YPdBi Heusler topological insulators. Owning to the successfully obtained the high-quality YPdBi single crystals, large non-saturating linear MR of as high as 350% at 5K and over 120% at 300K under a moderate magnetic field of 7T is observed. In addition to the large, field-linear MR, the samples exhibit pronounced SdH quantum oscillations at low temperature. Analysis of the SdH data manifests that the high-mobility bulk electron carriers dominate the magnetotransport and are responsible for the observed large linear MR in YPdBi crystals. These findings imply that the Heusler-based topological insulators have superiorities for investigating the novel quantum transport properties and developing the potential applications.

Large linear magnetoresistance and shubnikov-de hass oscillations in single crystals of YPdBi heusler topological insulators

KAUST Repository

Wang, Wenhong

2013-07-12

We report the observation of a large linear magnetoresistance (MR) and Shubnikov-de Hass (SdH) quantum oscillations in single crystals of YPdBi Heusler topological insulators. Owning to the successfully obtained the high-quality YPdBi single crystals, large non-saturating linear MR of as high as 350% at 5K and over 120% at 300K under a moderate magnetic field of 7T is observed. In addition to the large, field-linear MR, the samples exhibit pronounced SdH quantum oscillations at low temperature. Analysis of the SdH data manifests that the high-mobility bulk electron carriers dominate the magnetotransport and are responsible for the observed large linear MR in YPdBi crystals. These findings imply that the Heusler-based topological insulators have superiorities for investigating the novel quantum transport properties and developing the potential applications.

Imaging large cohorts of single ion channels and their activity

Directory of Open Access Journals (Sweden)

Katia eHiersemenzel

2013-09-01

Full Text Available As calcium is the most important signaling molecule in neurons and secretory cells, amongst many other cell types, it follows that an understanding of calcium channels and their regulation of exocytosis is of vital importance. Calcium imaging using calcium dyes such as Fluo3, or FRET-based dyes that have been used widely has provided invaluable information, which combined with modeling has estimated the sub-types of channels responsible for triggering the exocytotic machinery as well as inferences about the relative distances away from vesicle fusion sites these molecules adopt. Importantly, new super-resolution microscopy techniques, combined with novel Ca2+ indicators and imaginative imaging approaches can now define directly the nanoscale locations of very large cohorts of single channel molecules in relation to single vesicles. With combinations of these techniques the activity of individual channels can be visualized and quantified using novel Ca2+ indicators. Fluorescently labeled specific channel toxins can also be used to localize endogenous assembled channel tetramers. Fluorescence lifetime imaging microscopy and other single-photon-resolution spectroscopic approaches offer the possibility to quantify protein-protein interactions between populations of channels and the SNARE protein machinery for the first time. Together with simultaneous electrophysiology, this battery of quantitative imaging techniques has the potential to provide unprecedented detail describing the locations, dynamic behaviours, interactions and conductance activities of many thousands of channel molecules and vesicles in living cells.

Sensemaking in a Value Based Context for Large Scale Complex Engineered Systems

Science.gov (United States)

Sikkandar Basha, Nazareen

The design and the development of Large-Scale Complex Engineered Systems (LSCES) requires the involvement of multiple teams and numerous levels of the organization and interactions with large numbers of people and interdisciplinary departments. Traditionally, requirements-driven Systems Engineering (SE) is used in the design and development of these LSCES. The requirements are used to capture the preferences of the stakeholder for the LSCES. Due to the complexity of the system, multiple levels of interactions are required to elicit the requirements of the system within the organization. Since LSCES involves people and interactions between the teams and interdisciplinary departments, it should be socio-technical in nature. The elicitation of the requirements of most large-scale system projects are subjected to creep in time and cost due to the uncertainty and ambiguity of requirements during the design and development. In an organization structure, the cost and time overrun can occur at any level and iterate back and forth thus increasing the cost and time. To avoid such creep past researches have shown that rigorous approaches such as value based designing can be used to control it. But before the rigorous approaches can be used, the decision maker should have a proper understanding of requirements creep and the state of the system when the creep occurs. Sensemaking is used to understand the state of system when the creep occurs and provide a guidance to decision maker. This research proposes the use of the Cynefin framework, sensemaking framework which can be used in the design and development of LSCES. It can aide in understanding the system and decision making to minimize the value gap due to requirements creep by eliminating ambiguity which occurs during design and development. A sample hierarchical organization is used to demonstrate the state of the system at the occurrence of requirements creep in terms of cost and time using the Cynefin framework. These

Large or small angle MSW from single right-handed neutrino dominance

International Nuclear Information System (INIS)

King, S.F

2000-01-01

In this talk we discuss a natural explanation of both neutrino mass hierarchies and large neutrino mixing angles, as required by the atmospheric neutrino data, in terms of a single right-handed neutrino giving the dominant contribution to the 23 block of the light effective neutrino matrix, and illustrate this mechanism in the framework of models with U(1) family symmetries. Sub-dominant contributions from other right-handed neutrinos are required to give small mass splittings appropriate to the MSW solution to the solar neutrino problem. We present three explicit examples for achieving the small angle MSW solution in the framework of U(1) family symmetry models containing three right-handed neutrinos, which can naturally describe all quark and lepton masses and mixing angles. In this talk we also extend the analysis to the large angle MSW solution

Synthesis and characterization of p-type boron-doped IIb diamond large single crystals

International Nuclear Information System (INIS)

Li Shang-Sheng; Li Xiao-Lei; Su Tai-Chao; Jia Xiao-Peng; Ma Hong-An; Huang Guo-Feng; Li Yong

2011-01-01

High-quality p-type boron-doped IIb diamond large single crystals are successfully synthesized by the temperature gradient method in a china-type cubic anvil high-pressure apparatus at about 5.5 GPa and 1600 K. The morphologies and surface textures of the synthetic diamond crystals with different boron additive quantities are characterized by using an optical microscope and a scanning electron microscope respectively. The impurities of nitrogen and boron in diamonds are detected by micro Fourier transform infrared technique. The electrical properties including resistivities, Hall coefficients, Hall mobilities and carrier densities of the synthesized samples are measured by a four-point probe and the Hall effect method. The results show that large p-type boron-doped diamond single crystals with few nitrogen impurities have been synthesized. With the increase of quantity of additive boron, some high-index crystal faces such as {113} gradually disappear, and some stripes and triangle pits occur on the crystal surface. This work is helpful for the further research and application of boron-doped semiconductor diamond. (cross-disciplinary physics and related areas of science and technology)

Lutzomyia longipalpis in Brazil: a complex or a single species? A mini-review

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Luiz GSR Bauzer

2007-02-01

Full Text Available Lutzomyia longipalpis is the main vector of Leishmania infantum chagasi, the causative agent of American visceral leishmaniasis (AVL. Although there is strong evidence that Lu. longipalpis is a species complex, not all data concerning populations from Brazil support this hypothesis. The issue is still somewhat controversial for this large part of Lu. longipalpis distribution range even though that it is the Latin American region contributing to most of the cases of AVL. In this mini-review we consider in detail the current data for the Brazilian populations and conclude that Lu. longipalpis is a complex of incipient vector species with a complexity similar to Anopheles gambiae s.s. in Africa.

Hematological changes after single large dose half-body irradiation

International Nuclear Information System (INIS)

Herrmann, T.; Friedrich, S.; Jochem, I.; Eberhardt, H.J.; Koch, R.; Knorr, A.

1981-01-01

The determination of different peripheral blood parameters aimed at the study of side effects on the hematological cellular system following a 5 - 8 Gy single large dose half-body irradiation in 20 patients. Compared to the initial values the leukocytes between the 6. and 14., the thrombocytes between the 14. and 21. postirradiation day as well as the lymphocytes between 3 hours and 4 weeks postirradiation were significantly decreased without exhibiting complications such as hemorrhages or infections. The hemoglobin, hematocrit and reticulocyte values revealed but a slight decrease normalized within a 28 days postirradiation period. Transfusions were necessary when a tumor-caused anemia was present prior to irradiation. Changes in serum activity of aminotransferases and lactate dehydrogenase occured during the first hours after irradiation and were due to enzyme release from destroyed tumor cells

First Indian single center experience with pipeline embolization device for complex intracranial aneurysms.

Science.gov (United States)

Cherian, Mathew P; Yadav, Manish Kumar; Mehta, Pankaj; Vijayan, K; Arulselvan, V; Jayabalan, Suresh

2014-01-01

Flow diversion is a novel method of therapy wherein an endoluminal sleeve, the flow diverter stent is placed across the neck of complex aneurysms to curatively reconstruct abnormal vasculature. We present the first Indian single center experience with the pipeline embolization device (PED) and 6 months follow-up results of 5 patients. Five complex or recurrent intracranial aneurysms in five patients were treated with PED. The patients were followed-up with magnetic resonance angiography (MRA) after 4 weeks and conventional angiography after 6 months. Feasibility, complications, clinical outcome, early 1-month MRA and 6 months conventional angiographic follow-up results were analyzed. Of the five aneurysms treated, four were in the anterior circulation and one in the posterior circulation. All five patients were treated with a single PED in each, and additionally coils were used in one patient. At 1-month MRA follow-up, complete occlusion was seen in 2 (40%) of the five cases. Post 6 months conventional angiography showed complete occlusion of the aneurysm sac in all five cases (100%). Side branch ostia were covered in three patients, all of which were patent (100%). There was no incidence of major neurological morbidity or mortality. One patient (20%) who had basilar top aneurysm experienced minor neurological disability after 5 days which partially improved. Pipeline embolization device for complex and recurrent aneurysms is technically feasible, safe, offers low complication rate, and definitive vascular reconstruction. PED can be used without fear of occlusion of covered eloquent side branches and perforators.

Multiple plastic biliary stent placement in the management of large and multiple choledochal stones: single center experience and review of the literature.

Science.gov (United States)

Bektaş, Hasan; Gürbulak, Bünyamin; Şahin, Zeynep Deniz; Düzköylü, Yiğit; Çolak, Şükrü; Gürbulak, Esin Kabul; Güneş, Mehmet Emin; Çakar, Ekrem

2017-09-01

Endoscopic retrograde cholangiopancreatography (ERCP) with sphincterotomy is the first step treatment modality of choledocholithiasis. In spite of an extended sphincterotomy, 10-15% of complex choledochal stones (larger than 15 mm and/or more than 3 stones) cannot be removed and recurrent ERCP procedures may be needed. To evaluate the role and efficiency of multiple biliary stent application in the treatment of large and multiple choledochal stones. Patients with complex choledochal stones and patients with inadequate choledochal clearance during ERCP were included in the study. The study group was divided into 2 groups as the placement of single (n = 27 patients) or multiple stents (n = 58 patients). After a mean time interval of 21 days (10-28), the ERCP procedure was tried for the second time and a stent was placed in case of recurrence. Successful biliary drainage was provided in both groups. The decrease in the longitudinal or transverse size of the stones after stent placement was found to be statistically significant in both groups (p = 0.001). Cholestatic enzymes (alkaline phosphatase (ALP), γ-glutamyltransferase (GGT)) and bilirubin levels decreased significantly in both groups following stenting (p = 0.001). Additionally, multiple stents functioned as a bridge starting from the first ERCP to full clearance in patients with large and multiple stones which could not be removed at once and saved them from the possible morbidities of an invasive operation. Endoscopic multiple biliary stent placement should be preferred in the treatment of patients with complex choledochal stones and high rates of co-morbidity, as a safe alternative to surgery.

Management of large complex multi-stakeholders projects: a bibliometric approach

Directory of Open Access Journals (Sweden)

Aline Sacchi Homrich

2017-06-01

Full Text Available The growing global importance of large infrastructure projects has piqued the interest of many researchers in a variety of issues related to the management of large, multi-stakeholder projects, characterized by their high complexity and intense interaction among numerous stake-holders with distinct levels of responsibility. The objective of this study is to provide an overview of the academic literature focused on the management of these kinds of projects, describing the main themes considered, the lines of research identified and prominent trends. Bibliometric analysis techniques were used as well as network and content analysis. Research for information was performed in the scientific database, ISI Web of Knowledge and Scopus. The initial sample analysis consisted of 144 papers published between 1984 and 2014 and expanded to the references cited in these papers. The models identified in the literature converge with the following key-processes: project delivery systems; risk-management models; project cost management; public-private partnership.

Generating functional analysis of complex formation and dissociation in large protein interaction networks

International Nuclear Information System (INIS)

Coolen, A C C; Rabello, S

2009-01-01

We analyze large systems of interacting proteins, using techniques from the non-equilibrium statistical mechanics of disordered many-particle systems. Apart from protein production and removal, the most relevant microscopic processes in the proteome are complex formation and dissociation, and the microscopic degrees of freedom are the evolving concentrations of unbound proteins (in multiple post-translational states) and of protein complexes. Here we only include dimer-complexes, for mathematical simplicity, and we draw the network that describes which proteins are reaction partners from an ensemble of random graphs with an arbitrary degree distribution. We show how generating functional analysis methods can be used successfully to derive closed equations for dynamical order parameters, representing an exact macroscopic description of the complex formation and dissociation dynamics in the infinite system limit. We end this paper with a discussion of the possible routes towards solving the nontrivial order parameter equations, either exactly (in specific limits) or approximately.

Excess electron is trapped in a large single molecular cage C60F60.

Science.gov (United States)

Wang, Yin-Feng; Li, Zhi-Ru; Wu, Di; Sun, Chia-Chung; Gu, Feng-Long

2010-01-15

A new kind of solvated electron systems, sphere-shaped e(-)@C60F60 (I(h)) and capsule-shaped e(-)@C60F60 (D6h), in contrast to the endohedral complex M@C60, is represented at the B3LYP/6-31G(d) + dBF (diffusive basis functions) density functional theory. It is proven, by examining the singly occupied molecular orbital (SOMO) and the spin density map of e(-)@C60F60, that the excess electron is indeed encapsulated inside the C60F60 cage. The shape of the electron cloud in SOMO matches with the shape of C60F60 cage. These cage-like single molecular solvated electrons have considerably large vertical electron detachment energies VDE of 4.95 (I(h)) and 4.67 eV (D6h) at B3LYP/6-31+G(3df) + dBF level compared to the VDE of 3.2 eV for an electron in bulk water (Coe et al., Int Rev Phys Chem 2001, 20, 33) and that of 3.66 eV for e(-)@C20F20 (Irikura, J Phys Chem A 2008, 112, 983), which shows their higher stability. The VDE of the sphere-shaped e(-)@C60F60 (I(h)) is greater than that of the capsule-shaped e(-)@C60F60 (D6h), indicating that the excess electron prefers to reside in the cage with the higher symmetry to form the more stable solvated electron. It is also noticed that the cage size [7.994 (I(h)), 5.714 and 9.978 A (D6h) in diameter] is much larger than that (2.826 A) of (H2O)20- dodecahedral cluster (Khan, Chem Phys Lett 2005, 401, 85). Copyright 2009 Wiley Periodicals, Inc.

Can Effective Field Theory of inflation generate large tensor-to-scalar ratio within Randall–Sundrum single braneworld?

International Nuclear Information System (INIS)

Choudhury, Sayantan

2015-01-01

In this paper my prime objective is to explain the generation of large tensor-to-scalar ratio from the single field sub-Planckian inflationary paradigm within Randall–Sundrum (RS) single braneworld scenario in a model independent fashion. By explicit computation I have shown that the effective field theory prescription of brane inflation within RS single brane setup is consistent with sub-Planckian excursion of the inflaton field, which will further generate large value of tensor-to-scalar ratio, provided the energy density for inflaton degrees of freedom is high enough compared to the brane tension in high energy regime. Finally, I have mentioned the stringent theoretical constraint on positive brane tension, cut-off of the quantum gravity scale and bulk cosmological constant to get sub-Planckian field excursion along with large tensor-to-scalar ratio as recently observed by BICEP2 or at least generates the tensor-to-scalar ratio consistent with the upper bound of Planck (2013 and 2015) data and Planck+BICEP2+Keck Array joint constraint

Enhanced photoluminescence from single nitrogen-vacancy defects in nanodiamonds coated with phenol-ionic complexes.

Science.gov (United States)

Bray, Kerem; Previdi, Rodolfo; Gibson, Brant C; Shimoni, Olga; Aharonovich, Igor

2015-03-21

Fluorescent nanodiamonds are attracting major attention in the field of bio-sensing and bio-labeling. In this work we demonstrate a robust approach to achieve an encapsulation of individual nanodiamonds with phenol-ionic complexes that enhance the photoluminescence from single nitrogen vacancy (NV) centers. We show that single NV centres in the coated nanodiamonds also exhibit shorter lifetimes, opening another channel for high resolution sensing. We propose that the nanodiamond encapsulation reduces the non-radiative decay pathways of the NV color centers. Our results provide a versatile and assessable way to enhance photoluminescence from nanodiamond defects that can be used in a variety of sensing and imaging applications.

Fast and accurate detection of spread source in large complex networks.

Science.gov (United States)

Paluch, Robert; Lu, Xiaoyan; Suchecki, Krzysztof; Szymański, Bolesław K; Hołyst, Janusz A

2018-02-06

Spread over complex networks is a ubiquitous process with increasingly wide applications. Locating spread sources is often important, e.g. finding the patient one in epidemics, or source of rumor spreading in social network. Pinto, Thiran and Vetterli introduced an algorithm (PTVA) to solve the important case of this problem in which a limited set of nodes act as observers and report times at which the spread reached them. PTVA uses all observers to find a solution. Here we propose a new approach in which observers with low quality information (i.e. with large spread encounter times) are ignored and potential sources are selected based on the likelihood gradient from high quality observers. The original complexity of PTVA is O(N α ), where α ∈ (3,4) depends on the network topology and number of observers (N denotes the number of nodes in the network). Our Gradient Maximum Likelihood Algorithm (GMLA) reduces this complexity to O (N 2 log (N)). Extensive numerical tests performed on synthetic networks and real Gnutella network with limitation that id's of spreaders are unknown to observers demonstrate that for scale-free networks with such limitation GMLA yields higher quality localization results than PTVA does.

Large Out-of-Plane Displacement Bistable Electromagnetic Microswitch on a Single Wafer.

Science.gov (United States)

Miao, Xiaodan; Dai, Xuhan; Huang, Yi; Ding, Guifu; Zhao, Xiaolin

2016-05-05

This paper presents a bistable microswitch fully batch-fabricated on a single glass wafer, comprising of a microactuator, a signal transformer, a microspring and a permanent magnet. The bistable mechanism of the microswitch with large displacement of 160 μm depends on the balance of the magnetic force and elastic force. Both the magnetic force and elastic force were optimized by finite-element simulation to predict the reliable of the device. The prototype was fabricated and characterized. By utilizing thick laminated photoresist sacrificial layer, the large displacement was obtained to ensure the insulation of the microswitch. The testing results show that the microswitch realized the bistable mechanism at a 3-5 V input voltage and closed in 0.96 ms, which verified the simulation.

Assessing the validity of single-item life satisfaction measures: results from three large samples.

Science.gov (United States)

Cheung, Felix; Lucas, Richard E

2014-12-01

The present paper assessed the validity of single-item life satisfaction measures by comparing single-item measures to the Satisfaction with Life Scale (SWLS)-a more psychometrically established measure. Two large samples from Washington (N = 13,064) and Oregon (N = 2,277) recruited by the Behavioral Risk Factor Surveillance System and a representative German sample (N = 1,312) recruited by the Germany Socio-Economic Panel were included in the present analyses. Single-item life satisfaction measures and the SWLS were correlated with theoretically relevant variables, such as demographics, subjective health, domain satisfaction, and affect. The correlations between the two life satisfaction measures and these variables were examined to assess the construct validity of single-item life satisfaction measures. Consistent across three samples, single-item life satisfaction measures demonstrated substantial degree of criterion validity with the SWLS (zero-order r = 0.62-0.64; disattenuated r = 0.78-0.80). Patterns of statistical significance for correlations with theoretically relevant variables were the same across single-item measures and the SWLS. Single-item measures did not produce systematically different correlations compared to the SWLS (average difference = 0.001-0.005). The average absolute difference in the magnitudes of the correlations produced by single-item measures and the SWLS was very small (average absolute difference = 0.015-0.042). Single-item life satisfaction measures performed very similarly compared to the multiple-item SWLS. Social scientists would get virtually identical answer to substantive questions regardless of which measure they use.

Large system change challenges: addressing complex critical issues in linked physical and social domains

Science.gov (United States)

Waddell, Steve; Cornell, Sarah; Hsueh, Joe; Ozer, Ceren; McLachlan, Milla; Birney, Anna

2015-04-01

Most action to address contemporary complex challenges, including the urgent issues of global sustainability, occurs piecemeal and without meaningful guidance from leading complex change knowledge and methods. The potential benefit of using such knowledge is greater efficacy of effort and investment. However, this knowledge and its associated tools and methods are under-utilized because understanding about them is low, fragmented between diverse knowledge traditions, and often requires shifts in mindsets and skills from expert-led to participant-based action. We have been engaged in diverse action-oriented research efforts in Large System Change for sustainability. For us, "large" systems can be characterized as large-scale systems - up to global - with many components, of many kinds (physical, biological, institutional, cultural/conceptual), operating at multiple levels, driven by multiple forces, and presenting major challenges for people involved. We see change of such systems as complex challenges, in contrast with simple or complicated problems, or chaotic situations. In other words, issues and sub-systems have unclear boundaries, interact with each other, and are often contradictory; dynamics are non-linear; issues are not "controllable", and "solutions" are "emergent" and often paradoxical. Since choices are opportunity-, power- and value-driven, these social, institutional and cultural factors need to be made explicit in any actionable theory of change. Our emerging network is sharing and building a knowledge base of experience, heuristics, and theories of change from multiple disciplines and practice domains. We will present our views on focal issues for the development of the field of large system change, which include processes of goal-setting and alignment; leverage of systemic transitions and transformation; and the role of choice in influencing critical change processes, when only some sub-systems or levels of the system behave in purposeful ways

A large collapsed-state RNA can exhibit simple exponential single-molecule dynamics.

Science.gov (United States)

Smith, Glenna J; Lee, Kang Taek; Qu, Xiaohui; Xie, Zheng; Pesic, Jelena; Sosnick, Tobin R; Pan, Tao; Scherer, Norbert F

2008-05-09

The process of large RNA folding is believed to proceed from many collapsed structures to a unique functional structure requiring precise organization of nucleotides. The diversity of possible structures and stabilities of large RNAs could result in non-exponential folding kinetics (e.g. stretched exponential) under conditions where the molecules have not achieved their native state. We describe a single-molecule fluorescence resonance energy transfer (FRET) study of the collapsed-state region of the free energy landscape of the catalytic domain of RNase P RNA from Bacillus stearothermophilus (C(thermo)). Ensemble measurements have shown that this 260 residue RNA folds cooperatively to its native state at >or=1 mM Mg(2+), but little is known about the conformational dynamics at lower ionic strength. Our measurements of equilibrium conformational fluctuations reveal simple exponential kinetics that reflect a small number of discrete states instead of the expected inhomogeneous dynamics. The distribution of discrete dwell times, collected from an "ensemble" of 300 single molecules at each of a series of Mg(2+) concentrations, fit well to a double exponential, which indicates that the RNA conformational changes can be described as a four-state system. This finding is somewhat unexpected under [Mg(2+)] conditions in which this RNA does not achieve its native state. Observation of discrete well-defined conformations in this large RNA that are stable on the seconds timescale at low [Mg(2+)] (<0.1 mM) suggests that even at low ionic strength, with a tremendous number of possible (weak) interactions, a few critical interactions may produce deep energy wells that allow for rapid averaging of motions within each well, and yield kinetics that are relatively simple.

Axiomatic design in large systems complex products, buildings and manufacturing systems

CERN Document Server

Suh, Nam

2016-01-01

This book provides a synthesis of recent developments in Axiomatic Design theory and its application in large complex systems. Introductory chapters provide concise tutorial materials for graduate students and new practitioners, presenting the fundamentals of Axiomatic Design and relating its key concepts to those of model-based systems engineering. A mathematical exposition of design axioms is also provided. The main body of the book, which represents a concentrated treatment of several applications, is divided into three parts covering work on: complex products; buildings; and manufacturing systems. The book shows how design work in these areas can benefit from the scientific and systematic underpinning provided by Axiomatic Design, and in so doing effectively combines the state of the art in design research with practice. All contributions were written by an international group of leading proponents of Axiomatic Design. The book concludes with a call to action motivating further research into the engineeri...

Decay dynamics of neutral and charged excitonic complexes in single InAs/GaAs QDs

International Nuclear Information System (INIS)

Feucker, Max; Seguin, Robert; Rodt, Sven; Poetschke, Konstantin; Bimberg, Dieter

2008-01-01

Across the inhomogeneously broadened lineshape of a quantum dot (QD) ensemble the decay times are expected to vary since the wavefunctions and the oscillator strengths are sensitive to the actual geometry of the QD. We performed time-resolved cathodoluminescence spectroscopy of 26 different single InAs/GaAs QDs to investigate the decay dynamics of neutral and charged excitonic complexes. The largest decay rate was found for the XX + , followed by XX, X + and finally the X. We will show that the ratios of lifetimes of the different excitonic complexes are mainly governed by the number of involved recombination channels. There is excellent agreement between the measured and predicted values for the lifetime ratios of the neutral (X/XX) and the positively charged (X + /XX + ) complexes. Surprisingly the lifetime of the exciton (X) shows a much larger yet unexplained scatter than that of all the other complexes

Optimizing liquid effluent monitoring at a large nuclear complex.

Science.gov (United States)

Chou, Charissa J; Barnett, D Brent; Johnson, Vernon G; Olson, Phil M

2003-12-01

Effluent monitoring typically requires a large number of analytes and samples during the initial or startup phase of a facility. Once a baseline is established, the analyte list and sampling frequency may be reduced. Although there is a large body of literature relevant to the initial design, few, if any, published papers exist on updating established effluent monitoring programs. This paper statistically evaluates four years of baseline data to optimize the liquid effluent monitoring efficiency of a centralized waste treatment and disposal facility at a large defense nuclear complex. Specific objectives were to: (1) assess temporal variability in analyte concentrations, (2) determine operational factors contributing to waste stream variability, (3) assess the probability of exceeding permit limits, and (4) streamline the sampling and analysis regime. Results indicated that the probability of exceeding permit limits was one in a million under normal facility operating conditions, sampling frequency could be reduced, and several analytes could be eliminated. Furthermore, indicators such as gross alpha and gross beta measurements could be used in lieu of more expensive specific isotopic analyses (radium, cesium-137, and strontium-90) for routine monitoring. Study results were used by the state regulatory agency to modify monitoring requirements for a new discharge permit, resulting in an annual cost savings of US dollars 223,000. This case study demonstrates that statistical evaluation of effluent contaminant variability coupled with process knowledge can help plant managers and regulators streamline analyte lists and sampling frequencies based on detection history and environmental risk.

Assessing the Validity of Single-item Life Satisfaction Measures: Results from Three Large Samples

Science.gov (United States)

Cheung, Felix; Lucas, Richard E.

2014-01-01

Purpose The present paper assessed the validity of single-item life satisfaction measures by comparing single-item measures to the Satisfaction with Life Scale (SWLS) - a more psychometrically established measure. Methods Two large samples from Washington (N=13,064) and Oregon (N=2,277) recruited by the Behavioral Risk Factor Surveillance System (BRFSS) and a representative German sample (N=1,312) recruited by the Germany Socio-Economic Panel (GSOEP) were included in the present analyses. Single-item life satisfaction measures and the SWLS were correlated with theoretically relevant variables, such as demographics, subjective health, domain satisfaction, and affect. The correlations between the two life satisfaction measures and these variables were examined to assess the construct validity of single-item life satisfaction measures. Results Consistent across three samples, single-item life satisfaction measures demonstrated substantial degree of criterion validity with the SWLS (zero-order r = 0.62 – 0.64; disattenuated r = 0.78 – 0.80). Patterns of statistical significance for correlations with theoretically relevant variables were the same across single-item measures and the SWLS. Single-item measures did not produce systematically different correlations compared to the SWLS (average difference = 0.001 – 0.005). The average absolute difference in the magnitudes of the correlations produced by single-item measures and the SWLS were very small (average absolute difference = 0.015 −0.042). Conclusions Single-item life satisfaction measures performed very similarly compared to the multiple-item SWLS. Social scientists would get virtually identical answer to substantive questions regardless of which measure they use. PMID:24890827

Diffusion, capture and recycling of SCAR/WAVE and Arp2/3 complexes observed in cells by single-molecule imaging

Science.gov (United States)

Millius, Arthur; Watanabe, Naoki; Weiner, Orion D.

2012-01-01

The SCAR/WAVE complex drives lamellipodium formation by enhancing actin nucleation by the Arp2/3 complex. Phosphoinositides and Rac activate the SCAR/WAVE complex, but how SCAR/WAVE and Arp2/3 complexes converge at sites of nucleation is unknown. We analyzed the single-molecule dynamics of WAVE2 and p40 (subunits of the SCAR/WAVE and Arp2/3 complexes, respectively) in XTC cells. We observed lateral diffusion of both proteins and captured the transition of p40 from diffusion to network incorporation. These results suggest that a diffusive 2D search facilitates binding of the Arp2/3 complex to actin filaments necessary for nucleation. After nucleation, the Arp2/3 complex integrates into the actin network and undergoes retrograde flow, which results in its broad distribution throughout the lamellipodium. By contrast, the SCAR/WAVE complex is more restricted to the cell periphery. However, with single-molecule imaging, we also observed WAVE2 molecules undergoing retrograde motion. WAVE2 and p40 have nearly identical speeds, lifetimes and sites of network incorporation. Inhibition of actin retrograde flow does not prevent WAVE2 association and disassociation with the membrane but does inhibit WAVE2 removal from the actin cortex. Our results suggest that membrane binding and diffusion expedites the recruitment of nucleation factors to a nucleation site independent of actin assembly, but after network incorporation, ongoing actin polymerization facilitates recycling of SCAR/WAVE and Arp2/3 complexes. PMID:22349699

Adjoint-Based Aerodynamic Design of Complex Aerospace Configurations

Science.gov (United States)

Nielsen, Eric J.

2016-01-01

An overview of twenty years of adjoint-based aerodynamic design research at NASA Langley Research Center is presented. Adjoint-based algorithms provide a powerful tool for efficient sensitivity analysis of complex large-scale computational fluid dynamics (CFD) simulations. Unlike alternative approaches for which computational expense generally scales with the number of design parameters, adjoint techniques yield sensitivity derivatives of a simulation output with respect to all input parameters at the cost of a single additional simulation. With modern large-scale CFD applications often requiring millions of compute hours for a single analysis, the efficiency afforded by adjoint methods is critical in realizing a computationally tractable design optimization capability for such applications.

Life history of a large flake biface

Science.gov (United States)

Baena Preysler, Javier; Torres Navas, Concepción; Sharon, Gonen

2018-06-01

Bifaces, primarily handaxes and cleavers, are the hallmark of the Acheulian techno-complex lithic industry. They spread across Africa and Eurasia during the Early to Middle Pleistocene. While many attempts have been made to define and describe the typology and technology of these tools, most focus on a single stage in their manufacture and usage, from quarry to discard. These attempts are fragmented, primarily due to the fact that at no single site are all stages of biface manufacture and use represented. An additional factor that appears to impede attempts to present the full "life cycle" of bifaces is the view of all Acheulian assemblages as belonging to a single cultural entity. While all assemblages belong to the same techno-complex, distinct stages and phases should be recognized, each different in typology, technology, and probably also in chronology. This research focuses on the large flake stage of the Acheulian. Data accumulated over many years of research from different regions are analyzed together in an attempt to present a holistic view of the life cycle of a biface. The study of particular Acheulian sites from the Levant and Western Europe enables us to reconstruct all stages of the biface, from raw material exploitation to final discard. The result is a model more comprehensive and precise than those suggested previously for understanding the Large Flake Acheulian.

Methods Dealing with Complexity in Selecting Joint Venture Contractors for Large-Scale Infrastructure Projects

Directory of Open Access Journals (Sweden)

Ru Liang

2018-01-01

Full Text Available The magnitude of business dynamics has increased rapidly due to increased complexity, uncertainty, and risk of large-scale infrastructure projects. This fact made it increasingly tough to “go alone” into a contractor. As a consequence, joint venture contractors with diverse strengths and weaknesses cooperatively bid for bidding. Understanding project complexity and making decision on the optimal joint venture contractor is challenging. This paper is to study how to select joint venture contractors for undertaking large-scale infrastructure projects based on a multiattribute mathematical model. Two different methods are developed to solve the problem. One is based on ideal points and the other one is based on balanced ideal advantages. Both of the two methods consider individual difference in expert judgment and contractor attributes. A case study of Hong Kong-Zhuhai-Macao-Bridge (HZMB project in China is used to demonstrate how to apply these two methods and their advantages.

A single frequency component-based re-estimated MUSIC algorithm for impact localization on complex composite structures

International Nuclear Information System (INIS)

Yuan, Shenfang; Bao, Qiao; Qiu, Lei; Zhong, Yongteng

2015-01-01

The growing use of composite materials on aircraft structures has attracted much attention for impact monitoring as a kind of structural health monitoring (SHM) method. Multiple signal classification (MUSIC)-based monitoring technology is a promising method because of its directional scanning ability and easy arrangement of the sensor array. However, for applications on real complex structures, some challenges still exist. The impact-induced elastic waves usually exhibit a wide-band performance, giving rise to the difficulty in obtaining the phase velocity directly. In addition, composite structures usually have obvious anisotropy, and the complex structural style of real aircrafts further enhances this performance, which greatly reduces the localization precision of the MUSIC-based method. To improve the MUSIC-based impact monitoring method, this paper first analyzes and demonstrates the influence of measurement precision of the phase velocity on the localization results of the MUSIC impact localization method. In order to improve the accuracy of the phase velocity measurement, a single frequency component extraction method is presented. Additionally, a single frequency component-based re-estimated MUSIC (SFCBR-MUSIC) algorithm is proposed to reduce the localization error caused by the anisotropy of the complex composite structure. The proposed method is verified on a real composite aircraft wing box, which has T-stiffeners and screw holes. Three typical categories of 41 impacts are monitored. Experimental results show that the SFCBR-MUSIC algorithm can localize impact on complex composite structures with an obviously improved accuracy. (paper)

From isolated light-harvesting complexes to the thylakoid membrane: a single-molecule perspective

Science.gov (United States)

Gruber, J. Michael; Malý, Pavel; Krüger, Tjaart P. J.; Grondelle, Rienk van

2018-01-01

The conversion of solar radiation to chemical energy in plants and green algae takes place in the thylakoid membrane. This amphiphilic environment hosts a complex arrangement of light-harvesting pigment-protein complexes that absorb light and transfer the excitation energy to photochemically active reaction centers. This efficient light-harvesting capacity is moreover tightly regulated by a photoprotective mechanism called non-photochemical quenching to avoid the stress-induced destruction of the catalytic reaction center. In this review we provide an overview of single-molecule fluorescence measurements on plant light-harvesting complexes (LHCs) of varying sizes with the aim of bridging the gap between the smallest isolated complexes, which have been well-characterized, and the native photosystem. The smallest complexes contain only a small number (10-20) of interacting chlorophylls, while the native photosystem contains dozens of protein subunits and many hundreds of connected pigments. We discuss the functional significance of conformational dynamics, the lipid environment, and the structural arrangement of this fascinating nano-machinery. The described experimental results can be utilized to build mathematical-physical models in a bottom-up approach, which can then be tested on larger in vivo systems. The results also clearly showcase the general property of biological systems to utilize the same system properties for different purposes. In this case it is the regulated conformational flexibility that allows LHCs to switch between efficient light-harvesting and a photoprotective function.

Complex Parts, Complex Data: Why You Need to Understand What Radiation Single Event Testing Data Does and Doesn't Show and the Implications Thereof

Science.gov (United States)

LaBel, Kenneth A.; Berg, Melanie D.

2015-01-01

Electronic parts (integrated circuits) have grown in complexity such that determining all failure modes and risks from single particle event testing is impossible. In this presentation, the authors will present why this is so and provide some realism on what this means. Its all about understanding actual risks and not making assumptions.

Angularly-resolved elastic scatter from single particles collected over a large solid angle and with high resolution

International Nuclear Information System (INIS)

Aptowicz, Kevin B; Chang, Richard K

2005-01-01

Elastic light scattering from a single non-spherical particle of various morphologies has been measured simultaneously with a large angular range (90 deg. < θ < 165 deg. and 0 deg. < φ < 360 deg.) and with high angular resolution (1024 pixels in θ and 512 pixels in φ). Because the single-shot laser pulse is short (pulse duration of 70 ns), the tumbling and flowing particle can be treated as frozen in space. The large angle two-dimensional angular optical scattering (hereafter referred to as LA TAOS) intensity pattern, I(θ,φ), has been measured for a variety of particle morphology, such as the following: (1) single polystyrene latex (PSL) sphere; (2) cluster of PSL spheres; (3) single Bacillus subtilis (BG) spore; (4) cluster of BG spores; (5) dried aggregates of bio-aerosols as well as background clutter aerosols. All these measurements were made using the second harmonic of a Nd:YAG laser (0.532 μm). Islands structures in the LA TAOS patterns seem to be the prominent feature. Efforts are being made to extract metrics from these islands and compare them to theoretical results based on the T-matrix method

Single conversion audio amplifier and DC-AC converters with high performance and low complexity control scheme

DEFF Research Database (Denmark)

Poulsen, Søren; Andersen, Michael Andreas E.

2004-01-01

This paper proposes a novel control topology for a mains isolated single conversion audio amplifier and DC-AC converters. The topology is made for use in audio applications, and differs from prior art in terms of significantly reduced distortion as well as lower system complexity. The topology can...

DNA-Directed Assembly of Capture Tools for Constitutional Studies of Large Protein Complexes.

Science.gov (United States)

Meyer, Rebecca; Faesen, Alex; Vogel, Katrin; Jeganathan, Sadasivam; Musacchio, Andrea; Niemeyer, Christof M

2015-06-10

Large supramolecular protein complexes, such as the molecular machinery involved in gene regulation, cell signaling, or cell division, are key in all fundamental processes of life. Detailed elucidation of structure and dynamics of such complexes can be achieved by reverse-engineering parts of the complexes in order to probe their interactions with distinctive binding partners in vitro. The exploitation of DNA nanostructures to mimic partially assembled supramolecular protein complexes in which the presence and state of two or more proteins are decisive for binding of additional building blocks is reported here. To this end, four-way DNA Holliday junction motifs bearing a fluorescein and a biotin tag, for tracking and affinity capture, respectively, are site-specifically functionalized with centromeric protein (CENP) C and CENP-T. The latter serves as baits for binding of the so-called KMN component, thereby mimicking early stages of the assembly of kinetochores, structures that mediate and control the attachment of microtubules to chromosomes in the spindle apparatus. Results from pull-down experiments are consistent with the hypothesis that CENP-C and CENP-T may bind cooperatively to the KMN network. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Impacts of large dams on the complexity of suspended sediment dynamics in the Yangtze River

Science.gov (United States)

Wang, Yuankun; Rhoads, Bruce L.; Wang, Dong; Wu, Jichun; Zhang, Xiao

2018-03-01

The Yangtze River is one of the largest and most important rivers in the world. Over the past several decades, the natural sediment regime of the Yangtze River has been altered by the construction of dams. This paper uses multi-scale entropy analysis to ascertain the impacts of large dams on the complexity of high-frequency suspended sediment dynamics in the Yangtze River system, especially after impoundment of the Three Gorges Dam (TGD). In this study, the complexity of sediment dynamics is quantified by framing it within the context of entropy analysis of time series. Data on daily sediment loads for four stations located in the mainstem are analyzed for the past 60 years. The results indicate that dam construction has reduced the complexity of short-term (1-30 days) variation in sediment dynamics near the structures, but that complexity has actually increased farther downstream. This spatial pattern seems to reflect a filtering effect of the dams on the on the temporal pattern of sediment loads as well as decreased longitudinal connectivity of sediment transfer through the river system, resulting in downstream enhancement of the influence of local sediment inputs by tributaries on sediment dynamics. The TGD has had a substantial impact on the complexity of sediment series in the mainstem of the Yangtze River, especially after it became fully operational. This enhanced impact is attributed to the high trapping efficiency of this dam and its associated large reservoir. The sediment dynamics "signal" becomes more spatially variable after dam construction. This study demonstrates the spatial influence of dams on the high-frequency temporal complexity of sediment regimes and provides valuable information that can be used to guide environmental conservation of the Yangtze River.

Single-row versus double-row capsulolabral repair: a comparative evaluation of contact pressure and surface area in the capsulolabral complex-glenoid bone interface.

Science.gov (United States)

Kim, Doo-Sup; Yoon, Yeo-Seung; Chung, Hoi-Jeong

2011-07-01

Despite the attention that has been paid to restoration of the capsulolabral complex anatomic insertion onto the glenoid, studies comparing the pressurized contact area and mean interface pressure at the anatomic insertion site between a single-row repair and a double-row labral repair have been uncommon. The purpose of our study was to compare the mean interface pressure and pressurized contact area at the anatomic insertion site of the capsulolabral complex between a single-row repair and a double-row repair technique. Controlled laboratory study. Thirty fresh-frozen cadaveric shoulders (mean age, 61 ± 8 years; range, 48-71 years) were used for this study. Two types of repair were performed on each specimen: (1) a single-row repair and (2) a double-row repair. Using pressure-sensitive films, we examined the interface contact area and contact pressure. The mean interface pressure was greater for the double-row repair technique (0.29 ± 0.04 MPa) when compared with the single-row repair technique (0.21 ± 0.03 MPa) (P = .003). The mean pressurized contact area was also significantly greater for the double-row repair technique (211.8 ± 18.6 mm(2), 78.4% footprint) compared with the single-row repair technique (106.4 ± 16.8 mm(2), 39.4% footprint) (P = .001). The double-row repair has significantly greater mean interface pressure and pressurized contact area at the insertion site of the capsulolabral complex than the single-row repair. The double-row repair may be advantageous compared with the single-row repair in restoring the native footprint area of the capsulolabral complex.

Etoile Project : Social Intelligent ICT-System for very large scale education in complex systems

Science.gov (United States)

Bourgine, P.; Johnson, J.

2009-04-01

The project will devise new theory and implement new ICT-based methods of delivering high-quality low-cost postgraduate education to many thousands of people in a scalable way, with the cost of each extra student being negligible (Socially Intelligent Resource Mining system to gather large volumes of high quality educational resources from the internet; new methods to deconstruct these to produce a semantically tagged Learning Object Database; a Living Course Ecology to support the creation and maintenance of evolving course materials; systems to deliver courses; and a ‘socially intelligent assessment system'. The system will be tested on one to ten thousand postgraduate students in Europe working towards the Complex System Society's title of European PhD in Complex Systems. Étoile will have a very high impact both scientifically and socially by (i) the provision of new scalable ICT-based methods for providing very low cost scientific education, (ii) the creation of new mathematical and statistical theory for the multiscale dynamics of complex systems, (iii) the provision of a working example of adaptation and emergence in complex socio-technical systems, and (iv) making a major educational contribution to European complex systems science and its applications.

Development of a Single Locus Sequence Typing (SLST) Scheme for Typing Bacterial Species Directly from Complex Communities.

Science.gov (United States)

Scholz, Christian F P; Jensen, Anders

2017-01-01

The protocol describes a computational method to develop a Single Locus Sequence Typing (SLST) scheme for typing bacterial species. The resulting scheme can be used to type bacterial isolates as well as bacterial species directly from complex communities using next-generation sequencing technologies.

SV40 large T-p53 complex: evidence for the presence of two immunologically distinct forms of p53

International Nuclear Information System (INIS)

Milner, J.; Gamble, J.

1985-01-01

The transforming protein of SV40 is the large T antigen. Large T binds a cellular protein, p53, which is potentially oncogenic by virtue of its functional involvement in the control of cell proliferation. This raises the possibility that p53 may mediate, in part, the transforming function of SV40 large T. Two immunologically distinct forms of p53 have been identified in normal cells: the forms are cell-cycle dependent, one being restricted to nondividing cells (p53-Go) and the second to dividing cells (p53-G divided by). The authors have now dissociated and probed the multimeric complex of SV40 large T-p53 for the presence of immunologically distinct forms of p53. Here they present evidence for the presence of p53-Go and p53-G divided by complexed with SV40 large T

Single-molecule magnetism in three related {Co(III)2Dy(III)2}-acetylacetonate complexes with multiple relaxation mechanisms.

Science.gov (United States)

Langley, Stuart K; Chilton, Nicholas F; Moubaraki, Boujemaa; Murray, Keith S

2013-06-17

Three new heterometallic complexes with formulas of [Dy(III)2Co(III)2(OMe)2(teaH)2(acac)4(NO3)2] (1), [Dy(III)2Co(III)2(OH)2(teaH)2(acac)4(NO3)2]·4H2O (2), and [Dy(III)2Co(III)2(OMe)2(mdea)2(acac)4(NO3)2] (3) were characterized by single-crystal X-ray diffraction and by dc and ac magnetic susceptibility measurements. All three complexes have an identical "butterfly"-type metallic core that consists of two Dy(III) ions occupying the "body" position and two diamagnetic low-spin Co(III) ions occupying the outer "wing-tips". Each complex displays single-molecule magnet (SMM) behavior in zero applied magnetic field, with thermally activated anisotropy barriers of 27, 28, and 38 K above 7.5 K for 1-3, respectively, as well as observing a temperature-independent mechanism of relaxation below 5 K for 1 and 2 and at 3 K for 3, indicating fast quantum tunneling of magnetization (QTM). A second, faster thermally activated relaxation mechanism may also be active under a zero applied dc field as derived from the Cole-Cole data. Interestingly, these complexes demonstrate further relaxation modes that are strongly dependent upon the application of a static dc magnetic field. Dilution experiments that were performed on 1, in the {Y(III)2Co(III)2} diamagnetic analog, show that the slow magnetic relaxation is of a single-ion origin, but it was found that the neighboring ion also plays an important role in the overall relaxation dynamics.

Single-section mines carve out a market

International Nuclear Information System (INIS)

Sanda, A.P.

1991-01-01

In the Appalachian states of Pennsylvania, West Virginia, Kentucky and Virginia there are large operations whose complexes are an agglomeration of one and two-section mines; large operators whose own mines are augmented by small contractors; small contractors whose one-section mines collectively make them large operators within this genre; and independent, sole-owner operators of single-contract mines. Finally, there is the totally independent operator who negotiates his own leases, mines his own coal and searches for his own markets. The article profiles 6 single section mines. Mines were chosen on criteria including: the equipment in use; obtaining a representive sample of the states with many small coal mines particularly West Virginia, Virginia and Kentucky; the divergence of operators and situations. The mines chosen were: Elk Run; Kinney Branch Coal Co. No. 5 mine; A ampersand G No. 1 mine; Dotson and Rife Coal Co.; Bullion Hollow Coal Co.; and Bruce Coal. The article includes production rates and mine specifications. 1 tab

Automated NMR fragment based screening identified a novel interface blocker to the LARG/RhoA complex.

Directory of Open Access Journals (Sweden)

Jia Gao

Full Text Available The small GTPase cycles between the inactive GDP form and the activated GTP form, catalyzed by the upstream guanine exchange factors. The modulation of such process by small molecules has been proven to be a fruitful route for therapeutic intervention to prevent the over-activation of the small GTPase. The fragment based approach emerging in the past decade has demonstrated its paramount potential in the discovery of inhibitors targeting such novel and challenging protein-protein interactions. The details regarding the procedure of NMR fragment screening from scratch have been rarely disclosed comprehensively, thus restricts its wider applications. To achieve a consistent screening applicable to a number of targets, we developed a highly automated protocol to cover every aspect of NMR fragment screening as possible, including the construction of small but diverse libray, determination of the aqueous solubility by NMR, grouping compounds with mutual dispersity to a cocktail, and the automated processing and visualization of the ligand based screening spectra. We exemplified our streamlined screening in RhoA alone and the complex of the small GTPase RhoA and its upstream guanine exchange factor LARG. Two hits were confirmed from the primary screening in cocktail and secondary screening over individual hits for LARG/RhoA complex, while one of them was also identified from the screening for RhoA alone. HSQC titration of the two hits over RhoA and LARG alone, respectively, identified one compound binding to RhoA.GDP at a 0.11 mM affinity, and perturbed the residues at the switch II region of RhoA. This hit blocked the formation of the LARG/RhoA complex, validated by the native gel electrophoresis, and the titration of RhoA to ¹⁵N labeled LARG in the absence and presence the compound, respectively. It therefore provides us a starting point toward a more potent inhibitor to RhoA activation catalyzed by LARG.

Multi-tap complex-coefficient incoherent microwave photonic filters based on optical single-sideband modulation and narrow band optical filtering.

Science.gov (United States)

Sagues, Mikel; García Olcina, Raimundo; Loayssa, Alayn; Sales, Salvador; Capmany, José

2008-01-07

We propose a novel scheme to implement tunable multi-tap complex coefficient filters based on optical single sideband modulation and narrow band optical filtering. A four tap filter is experimentally demonstrated to highlight the enhanced tuning performance provided by complex coefficients. Optical processing is performed by the use of a cascade of four phase-shifted fiber Bragg gratings specifically fabricated for this purpose.

Electrical manipulation of spin states in a single electrostatically gated transition-metal complex

DEFF Research Database (Denmark)

Osorio, Edgar A; Moth-Poulsen, Kasper; van der Zant, Herre S J

2010-01-01

-field on the Mn-atom. Adding a single electron thus stabilizes the low-spin configuration and the corresponding sequential tunnelling current is suppressed by spin-blockade. From low-temperature inelastic cotunneling spectroscopy, we infer the magnetic excitation spectrum of the molecule and uncover also...... a strongly gate-dependent singlet-triplet splitting on the low-spin side. The measured bias-spectroscopy is shown to be consistent with an exact diagonalization of the Mn-complex, and an interpretation of the data is given in terms of a simplified effective model....

Extracting Models in Single Molecule Experiments

Science.gov (United States)

Presse, Steve

2013-03-01

Single molecule experiments can now monitor the journey of a protein from its assembly near a ribosome to its proteolytic demise. Ideally all single molecule data should be self-explanatory. However data originating from single molecule experiments is particularly challenging to interpret on account of fluctuations and noise at such small scales. Realistically, basic understanding comes from models carefully extracted from the noisy data. Statistical mechanics, and maximum entropy in particular, provide a powerful framework for accomplishing this task in a principled fashion. Here I will discuss our work in extracting conformational memory from single molecule force spectroscopy experiments on large biomolecules. One clear advantage of this method is that we let the data tend towards the correct model, we do not fit the data. I will show that the dynamical model of the single molecule dynamics which emerges from this analysis is often more textured and complex than could otherwise come from fitting the data to a pre-conceived model.

A dynamic globalization model for large eddy simulation of complex turbulent flow

Energy Technology Data Exchange (ETDEWEB)

Choi, Hae Cheon; Park, No Ma; Kim, Jin Seok [Seoul National Univ., Seoul (Korea, Republic of)

2005-07-01

A dynamic subgrid-scale model is proposed for large eddy simulation of turbulent flows in complex geometry. The eddy viscosity model by Vreman [Phys. Fluids, 16, 3670 (2004)] is considered as a base model. A priori tests with the original Vreman model show that it predicts the correct profile of subgrid-scale dissipation in turbulent channel flow but the optimal model coefficient is far from universal. Dynamic procedures of determining the model coefficient are proposed based on the 'global equilibrium' between the subgrid-scale dissipation and viscous dissipation. An important feature of the proposed procedures is that the model coefficient determined is globally constant in space but varies only in time. Large eddy simulations with the present dynamic model are conducted for forced isotropic turbulence, turbulent channel flow and flow over a sphere, showing excellent agreements with previous results.

Outcomes of the single-stent versus kissing-stents technique in asymmetric complex aortoiliac bifurcation lesions.

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Suh, Yongsung; Ko, Young-Guk; Shin, Dong-Ho; Kim, Jung-Sun; Kim, Byeong-Keuk; Choi, Donghoon; Hong, Myeong-Ki; Jang, Yangsoo

2015-07-01

This study investigated the outcomes of single-stent vs kissing-stents techniques in asymmetric complex aortoiliac bifurcation (ACAB) lesions. We retrospectively investigated 80 consecutive patients (69 males, 66.6 ± 8.7 years) treated with a single stent and 30 patients (26 males, 67.1 ± 7.7 years) treated with kissing stents for ACAB between January 2005 and December 2012 from a single-center cohort. A ACAB lesion was defined as a symptomatic unilateral common iliac artery stenosis (>50%) combined with intermediate stenosis (30%-50%) in the contralateral common iliac artery ostium. The primary end point was the primary patency of the ACAB. The baseline clinical characteristics did not differ significantly between the single-stent and the kissing-stents group. Technical success was achieved in all patients. The single-stent group required fewer stents (1.3 ± 0.5 vs 2.3 ± 0.8; P stent group (3%) required bailout kissing stents because of plaque shift to the contralateral side. The major complication rates were 8% in single-stent vs 13% in the kissing-stent group, which was similar (P = .399). At 3 years, the single-stent and kissing-stents group had similar rates of primary patency (89% vs 87%; P = .916) and target lesion revascularization-free survival (93% vs 87%; P = .462). The single-stent technique in ACAB was safe and showed midterm outcomes comparable with those of kissing stents. Considering the benefits, such as fewer stents, less bilateral femoral access, and the availability of contralateral access for future intervention, the single-stent technique may be an advantageous treatment option in ACAB. Copyright © 2015 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

Space Situational Awareness of Large Numbers of Payloads From a Single Deployment

Science.gov (United States)

Segerman, A.; Byers, J.; Emmert, J.; Nicholas, A.

2014-09-01

The nearly simultaneous deployment of a large number of payloads from a single vehicle presents a new challenge for space object catalog maintenance and space situational awareness (SSA). Following two cubesat deployments last November, it took five weeks to catalog the resulting 64 orbits. The upcoming Kicksat mission will present an even greater SSA challenge, with its deployment of 128 chip-sized picosats. Although all of these deployments are in short-lived orbits, future deployments will inevitably occur at higher altitudes, with a longer term threat of collision with active spacecraft. With such deployments, individual scientific payload operators require rapid precise knowledge of their satellites' locations. Following the first November launch, the cataloguing did not initially associate a payload with each orbit, leaving this to the satellite operators. For short duration missions, the time required to identify an experiment's specific orbit may easily be a large fraction of the spacecraft's lifetime. For a Kicksat-type deployment, present tracking cannot collect enough observations to catalog each small object. The current approach is to treat the chip cloud as a single catalog object. However, the cloud dissipates into multiple subclouds and, ultimately, tiny groups of untrackable chips. One response to this challenge may be to mandate installation of a transponder on each spacecraft. Directional transponder transmission detections could be used as angle observations for orbit cataloguing. Of course, such an approach would only be employable with cooperative spacecraft. In other cases, a probabilistic association approach may be useful, with the goal being to establish the probability of an element being at a given point in space. This would permit more reliable assessment of the probability of collision of active spacecraft with any cloud element. This paper surveys the cataloguing challenges presented by large scale deployments of small spacecraft

Low-temperature protein dynamics of the B800 molecules in the LH2 light-harvesting complex: spectral hole burning study and comparison with single photosynthetic complex spectroscopy.

Science.gov (United States)

Grozdanov, Daniel; Herascu, Nicoleta; Reinot, Tõnu; Jankowiak, Ryszard; Zazubovich, Valter

2010-03-18

Previously published and new spectral hole burning (SHB) data on the B800 band of LH2 light-harvesting antenna complex of Rps. acidophila are analyzed in light of recent single photosynthetic complex spectroscopy (SPCS) results (for a review, see Berlin et al. Phys. Life Rev. 2007, 4, 64.). It is demonstrated that, in general, SHB-related phenomena observed for the B800 band are in qualitative agreement with the SPCS data and the protein models involving multiwell multitier protein energy landscapes. Regarding the quantitative agreement, we argue that the single-molecule behavior associated with the fastest spectral diffusion (smallest barrier) tier of the protein energy landscape is inconsistent with the SHB data. The latter discrepancy can be attributed to SPCS probing not only the dynamics of of the protein complex per se, but also that of the surrounding amorphous host and/or of the host-protein interface. It is argued that SHB (once improved models are developed) should also be able to provide the average magnitudes and probability distributions of light-induced spectral shifts and could be used to determine whether SPCS probes a set of protein complexes that are both intact and statistically relevant. SHB results are consistent with the B800 --> B850 energy-transfer models including consideration of the whole B850 density of states.

Characterization of Aftershock Sequences from Large Strike-Slip Earthquakes Along Geometrically Complex Faults

Science.gov (United States)

Sexton, E.; Thomas, A.; Delbridge, B. G.

2017-12-01

Large earthquakes often exhibit complex slip distributions and occur along non-planar fault geometries, resulting in variable stress changes throughout the region of the fault hosting aftershocks. To better discern the role of geometric discontinuities on aftershock sequences, we compare areas of enhanced and reduced Coulomb failure stress and mean stress for systematic differences in the time dependence and productivity of these aftershock sequences. In strike-slip faults, releasing structures, including stepovers and bends, experience an increase in both Coulomb failure stress and mean stress during an earthquake, promoting fluid diffusion into the region and further failure. Conversely, Coulomb failure stress and mean stress decrease in restraining bends and stepovers in strike-slip faults, and fluids diffuse away from these areas, discouraging failure. We examine spatial differences in seismicity patterns along structurally complex strike-slip faults which have hosted large earthquakes, such as the 1992 Mw 7.3 Landers, the 2010 Mw 7.2 El-Mayor Cucapah, the 2014 Mw 6.0 South Napa, and the 2016 Mw 7.0 Kumamoto events. We characterize the behavior of these aftershock sequences with the Epidemic Type Aftershock-Sequence Model (ETAS). In this statistical model, the total occurrence rate of aftershocks induced by an earthquake is λ(t) = λ_0 + \\sum_{i:t_i

The method of measurement and synchronization control for large-scale complex loading system

International Nuclear Information System (INIS)

Liao Min; Li Pengyuan; Hou Binglin; Chi Chengfang; Zhang Bo

2012-01-01

With the development of modern industrial technology, measurement and control system was widely used in high precision, complex industrial control equipment and large-tonnage loading device. The measurement and control system is often used to analyze the distribution of stress and displacement in the complex bearing load or the complex nature of the mechanical structure itself. In ITER GS mock-up with 5 flexible plates, for each load combination, detect and measure potential slippage between the central flexible plate and the neighboring spacers is necessary as well as the potential slippage between each pre-stressing bar and its neighboring plate. The measurement and control system consists of seven sets of EDC controller and board, computer system, 16-channel quasi-dynamic strain gauge, 25 sets of displacement sensors, 7 sets of load and displacement sensors in the cylinders. This paper demonstrates the principles and methods of EDC220 digital controller to achieve synchronization control, and R and D process of multi-channel loading control software and measurement software. (authors)

A measurement system for large, complex software programs

Science.gov (United States)

Rone, Kyle Y.; Olson, Kitty M.; Davis, Nathan E.

1994-01-01

This paper describes measurement systems required to forecast, measure, and control activities for large, complex software development and support programs. Initial software cost and quality analysis provides the foundation for meaningful management decisions as a project evolves. In modeling the cost and quality of software systems, the relationship between the functionality, quality, cost, and schedule of the product must be considered. This explicit relationship is dictated by the criticality of the software being developed. This balance between cost and quality is a viable software engineering trade-off throughout the life cycle. Therefore, the ability to accurately estimate the cost and quality of software systems is essential to providing reliable software on time and within budget. Software cost models relate the product error rate to the percent of the project labor that is required for independent verification and validation. The criticality of the software determines which cost model is used to estimate the labor required to develop the software. Software quality models yield an expected error discovery rate based on the software size, criticality, software development environment, and the level of competence of the project and developers with respect to the processes being employed.

Retrograde Ureteroscopic Management of Large Renal Calculi: A Single Institutional Experience and Concise Literature Review.

Science.gov (United States)

Scotland, Kymora B; Rudnick, Benjamin; Healy, Kelly A; Hubosky, Scott G; Bagley, Demetrius H

2018-06-06

Advances in flexible ureteroscope design and accessory instrumentation have allowed for more challenging cases to be treated ureteroscopically. Here, we evaluate our experience with ureteroscopy (URS) for the management of large renal calculi (≥2 cm) and provide a concise review of recent reports. A retrospective review was undertaken of all URS cases between 2004 and 2014 performed by the endourologic team at a single academic tertiary care institution. We identified patients with at least one stone ≥2 cm managed with retrograde URS. Stone size was defined as the largest linear diameter of the index stone. Small diameter flexible ureteroscopes were used primarily with holmium laser. Patient demographics, intraoperative data, and postoperative outcomes were evaluated. We evaluated 167 consecutive patients who underwent URS for large renal stones ≥2 cm. The initial reason for choosing URS included patient preference (29.5%), failure of other therapies (8.2%), anatomic considerations/body habitus (30.3%), and comorbidities (28.8%). Mean patient age was 55.5 years (22-84). The mean stone size was 2.75 cm with mean number of procedures per patient of 1.65 (1-6). The single session stone-free rate was 57.1%, two-stage procedure stone-free rate was 90.2% and three-stage stone-free rate was 94.0%. Access sheaths were used in 47% of patients. An association was identified between stone size and patient outcomes; smaller stones correlated with decreased number of procedures. Postoperative complications were minor. Single or multi-stage retrograde ureteroscopic lithotripsy is a safe and effective mode of surgical management of large renal calculi. Total stone burden is a reliable predictor of the need for a staged procedure and of stone-free rate.

Size-dependent binding energies and fine-structure splitting of excitonic complexes in single InAs/GaAs quantum dots

International Nuclear Information System (INIS)

Rodt, S.; Seguin, R.; Schliwa, A.; Guffarth, F.; Poetschke, K.; Pohl, U.W.; Bimberg, D.

2007-01-01

A systematic study of excitonic complexes confined in single InAs/GaAs quantum dots is presented. Emphasis is placed on the recombination energies of the excitonic complexes and on the fine-structure splitting of the bright exciton ground state. The values depend in a characteristic way on the size of the respective quantum dot which controls the number of bound hole states and the piezoelectric potential

Characterize kinematic rupture history of large earthquakes with Multiple Haskell sources

Science.gov (United States)

Jia, Z.; Zhan, Z.

2017-12-01

Earthquakes are often regarded as continuous rupture along a single fault, but the occurrence of complex large events involving multiple faults and dynamic triggering challenges this view. Such rupture complexities cause difficulties in existing finite fault inversion algorithms, because they rely on specific parameterizations and regularizations to obtain physically meaningful solutions. Furthermore, it is difficult to assess reliability and uncertainty of obtained rupture models. Here we develop a Multi-Haskell Source (MHS) method to estimate rupture process of large earthquakes as a series of sub-events of varying location, timing and directivity. Each sub-event is characterized by a Haskell rupture model with uniform dislocation and constant unilateral rupture velocity. This flexible yet simple source parameterization allows us to constrain first-order rupture complexity of large earthquakes robustly. Additionally, relatively few parameters in the inverse problem yields improved uncertainty analysis based on Markov chain Monte Carlo sampling in a Bayesian framework. Synthetic tests and application of MHS method on real earthquakes show that our method can capture major features of large earthquake rupture process, and provide information for more detailed rupture history analysis.

The method of arbitrarily large moments to calculate single scale processes in quantum field theory

Energy Technology Data Exchange (ETDEWEB)

Bluemlein, Johannes [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Schneider, Carsten [Johannes Kepler Univ., Linz (Austria). Research Inst. for Symbolic Computation (RISC)

2017-01-15

We device a new method to calculate a large number of Mellin moments of single scale quantities using the systems of differential and/or difference equations obtained by integration-by-parts identities between the corresponding Feynman integrals of loop corrections to physical quantities. These scalar quantities have a much simpler mathematical structure than the complete quantity. A sufficiently large set of moments may even allow the analytic reconstruction of the whole quantity considered, holding in case of first order factorizing systems. In any case, one may derive highly precise numerical representations in general using this method, which is otherwise completely analytic.

Large-scale single-crystal growth of (CH3)2NH2CuCl3 for neutron scattering experiments

Science.gov (United States)

Park, Garam; Oh, In-Hwan; Park, J. M. Sungil; Park, Seong-Hun; Hong, Chang Seop; Lee, Kwang-Sei

2016-05-01

Neutron scattering studies on low-dimensional quantum spin systems require large-size single-crystals. Single-crystals of (CH3)2NH2CuCl3 showing low-dimensional magnetic behaviors were grown by a slow solvent evaporation method in a two-solvent system at different temperature settings. The best results were obtained for the bilayer solution of methanol and isopropanol with a molar ratio of 2:1 at 35 °C. The quality of the obtained single-crystals was tested by powder and single-crystal X-ray diffraction and single-crystal neutron diffraction. In addition, to confirm structural phase transitions (SPTs), thermal analysis and single-crystal X-ray diffraction at 300 K and 175 K, respectively, were conducted, confirming the presence of a SPT at Tup=288 K on heating and Tdown=285 K on cooling.

A structural investigation of complex I and I+III2 supercomplex from Zea mays at 11-13 angstrom resolution : Assignment of the carbonic anhydrase domain and evidence for structural heterogeneity within complex I

NARCIS (Netherlands)

Peters, Katrin; Dudkina, Natalya V.; Jaensch, Lothar; Braun, Hans-Peter; Boekema, Egbert J.; Jänsch, Lothar

The projection structures of complex I and the I+III2 supercomplex from the C-4 plant Zea mays were determined by electron microscopy and single particle image analysis to a resolution of up to 11 angstrom. Maize complex I has a typical L-shape. Additionally, it has a large hydrophilic, extra-domain

"Switching on" the properties of single-molecule magnetism in triangular manganese(III) complexes.

Science.gov (United States)

Stamatatos, Theocharis C; Foguet-Albiol, Dolos; Lee, Sheng-Chiang; Stoumpos, Constantinos C; Raptopoulou, Catherine P; Terzis, Aris; Wernsdorfer, Wolfgang; Hill, Stephen O; Perlepes, Spyros P; Christou, George

2007-08-01

The reaction between oxide-centered, triangular [MnIII3O(O2CR)6(py)3](ClO4) (R = Me (1), Et (2), Ph (3)) compounds and methyl 2-pyridyl ketone oxime (mpkoH) affords a new family of Mn/carboxylato/oximato complexes, [MnIII3O(O2CR)3(mpko)3](ClO4) [R = Me (4), Et (5), and Ph (6)]. As in 1-3, the cations of 4-6 contain an [MnIII3(mu3-O)]7+ triangular core, but with each Mn2 edge now bridged by an eta1:eta1:mu-RCO2- and an eta1:eta1:eta1:mu-mpko- group. The tridentate binding mode of the latter causes a buckling of the formerly planar [MnIII3(mu3-O)]7+ core, resulting in a relative twisting of the three MnIII octahedra and the central O2- ion now lying approximately 0.3 A above the Mn3 plane. This structural distortion leads to ferromagnetic exchange interactions within the molecule and a resulting S = 6 ground state. Fits of dc magnetization data for 4-6 collected in the 1.8-10.0 K and 10-70 kG ranges confirmed S = 6 ground states, and gave the following D and g values: -0.34 cm(-1) and 1.92 for 4, -0.34 cm(-1) and 1.93 for 5, and -0.35 cm(-1) and 1.99 for 6, where D is the axial zero-field splitting (anisotropy) parameter. Complexes 4-6 all exhibit frequency-dependent out-of-phase (chi" M) ac susceptibility signals suggesting them possibly to be single-molecule magnets (SMMs). Relaxation rate vs T data for complex 4 down to 1.8 K obtained from the chi" M vs T studies were supplemented with rate vs T data measured to 0.04 K via magnetization vs time decay studies, and these were used to construct Arrhenius plots from which was obtained the effective barrier to relaxation (Ueff) of 10.9 K. Magnetization vs dc field sweeps on single-crystals of 4.3CH2Cl2 displayed hysteresis loops exhibiting steps due to quantum tunneling of magnetization (QTM). The loops were essentially temperature-independent below approximately 0.3 K, indicating only ground-state QTM between the lowest-lying Ms = +/-6 levels. Complexes 4-6 are thus confirmed as the first triangular SMMs. High

Validation of single-plane fluoroscopy and 2D/3D shape-matching for quantifying shoulder complex kinematics.

Science.gov (United States)

Lawrence, Rebekah L; Ellingson, Arin M; Ludewig, Paula M

2018-02-01

Fluoroscopy and 2D/3D shape-matching has emerged as the standard for non-invasively quantifying kinematics. However, its accuracy has not been well established for the shoulder complex when using single-plane fluoroscopy. The purpose of this study was to determine the accuracy of single-plane fluoroscopy and 2D/3D shape-matching for quantifying full shoulder complex kinematics. Tantalum markers were implanted into the clavicle, humerus, and scapula of four cadaveric shoulders. Biplane radiographs were obtained with the shoulder in five humerothoracic elevation positions (arm at the side, 30°, 60°, 90°, maximum). Images from both systems were used to perform marker tracking, while only those images acquired with the primary fluoroscopy system were used to perform 2D/3D shape-matching. Kinematics errors due to shape-matching were calculated as the difference between marker tracking and 2D/3D shape-matching and expressed as root mean square (RMS) error, bias, and precision. Overall RMS errors for the glenohumeral joint ranged from 0.7 to 3.3° and 1.2 to 4.2 mm, while errors for the acromioclavicular joint ranged from 1.7 to 3.4°. Errors associated with shape-matching individual bones ranged from 1.2 to 3.2° for the humerus, 0.5 to 1.6° for the scapula, and 0.4 to 3.7° for the clavicle. The results of the study demonstrate that single-plane fluoroscopy and 2D/3D shape-matching can accurately quantify full shoulder complex kinematics in static positions. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.

Bend compensated large-mode-area fibers: achieving robust single-modedness with transformation optics.

Science.gov (United States)

Fini, John M; Nicholson, Jeffrey W

2013-08-12

Fibers with symmetric bend compensated claddings are proposed, and demonstrate performance much better than conventional designs. These fibers can simultaneously achieve complete HOM suppression, negligible bend loss, and mode area >1000 square microns. The robust single-modedness of these fibers offers a path to overcoming mode instability limits on high-power amplifiers and lasers. The proposed designs achieve many of the advantages of our previous (asymmetric) bend compensation strategy in the regime of moderately large area, and are much easier to fabricate and utilize.

Structures of human Golgi-resident glutaminyl cyclase and its complexes with inhibitors reveal a large loop movement upon inhibitor binding.

Science.gov (United States)

Huang, Kai-Fa; Liaw, Su-Sen; Huang, Wei-Lin; Chia, Cho-Yun; Lo, Yan-Chung; Chen, Yi-Ling; Wang, Andrew H-J

2011-04-08

Aberrant pyroglutamate formation at the N terminus of certain peptides and proteins, catalyzed by glutaminyl cyclases (QCs), is linked to some pathological conditions, such as Alzheimer disease. Recently, a glutaminyl cyclase (QC) inhibitor, PBD150, was shown to be able to reduce the deposition of pyroglutamate-modified amyloid-β peptides in brain of transgenic mouse models of Alzheimer disease, leading to a significant improvement of learning and memory in those transgenic animals. Here, we report the 1.05-1.40 Å resolution structures, solved by the sulfur single-wavelength anomalous dispersion phasing method, of the Golgi-luminal catalytic domain of the recently identified Golgi-resident QC (gQC) and its complex with PBD150. We also describe the high-resolution structures of secretory QC (sQC)-PBD150 complex and two other gQC-inhibitor complexes. gQC structure has a scaffold similar to that of sQC but with a relatively wider and negatively charged active site, suggesting a distinct substrate specificity from sQC. Upon binding to PBD150, a large loop movement in gQC allows the inhibitor to be tightly held in its active site primarily by hydrophobic interactions. Further comparisons of the inhibitor-bound structures revealed distinct interactions of the inhibitors with gQC and sQC, which are consistent with the results from our inhibitor assays reported here. Because gQC and sQC may play different biological roles in vivo, the different inhibitor binding modes allow the design of specific inhibitors toward gQC and sQC.

Tunable complex-valued multi-tap microwave photonic filter based on single silicon-on-insulator microring resonator.

Science.gov (United States)

Lloret, Juan; Sancho, Juan; Pu, Minhao; Gasulla, Ivana; Yvind, Kresten; Sales, Salvador; Capmany, José

2011-06-20

A complex-valued multi-tap tunable microwave photonic filter based on single silicon-on-insulator microring resonator is presented. The degree of tunability of the approach involving two, three and four taps is theoretical and experimentally characterized, respectively. The constraints of exploiting the optical phase transfer function of a microring resonator aiming at implementing complex-valued multi-tap filtering schemes are also reported. The trade-off between the degree of tunability without changing the free spectral range and the number of taps is studied in-depth. Different window based scenarios are evaluated for improving the filter performance in terms of the side-lobe level.

Demonstration of acoustic source localization in air using single pixel compressive imaging

Science.gov (United States)

Rogers, Jeffrey S.; Rohde, Charles A.; Guild, Matthew D.; Naify, Christina J.; Martin, Theodore P.; Orris, Gregory J.

2017-12-01

Acoustic source localization often relies on large sensor arrays that can be electronically complex and have large data storage requirements to process element level data. Recently, the concept of a single-pixel-imager has garnered interest in the electromagnetics literature due to its ability to form high quality images with a single receiver paired with shaped aperture screens that allow for the collection of spatially orthogonal measurements. Here, we present a method for creating an acoustic analog to the single-pixel-imager found in electromagnetics for the purpose of source localization. Additionally, diffraction is considered to account for screen openings comparable to the acoustic wavelength. A diffraction model is presented and incorporated into the single pixel framework. In this paper, we explore the possibility of applying single pixel localization to acoustic measurements. The method is experimentally validated with laboratory measurements made in an air waveguide.

An Improved Conceptually-Based Method for Analysis of Communication Network Structure of Large Complex Organizations.

Science.gov (United States)

Richards, William D., Jr.

Previous methods for determining the communication structure of organizations work well for small or simple organizations, but are either inadequate or unwieldy for use with large complex organizations. An improved method uses a number of different measures and a series of successive approximations to order the communication matrix such that…

A Proactive Complex Event Processing Method for Large-Scale Transportation Internet of Things

OpenAIRE

Wang, Yongheng; Cao, Kening

2014-01-01

The Internet of Things (IoT) provides a new way to improve the transportation system. The key issue is how to process the numerous events generated by IoT. In this paper, a proactive complex event processing method is proposed for large-scale transportation IoT. Based on a multilayered adaptive dynamic Bayesian model, a Bayesian network structure learning algorithm using search-and-score is proposed to support accurate predictive analytics. A parallel Markov decision processes model is design...

Focusing of white synchrotron radiation using large-acceptance cylindrical refractive lenses made of single – crystal diamond

Energy Technology Data Exchange (ETDEWEB)

Polikarpov, M., E-mail: polikarpov.maxim@mail.ru [Immanuel Kant Baltic Federal University, Nevskogo 14a, 23600 Kaliningrad (Russian Federation); Snigireva, I. [European Synchrotron Radiation Facility, 71 avenue des Martyrs, Grenoble 38043 (France); Snigirev, A. [Immanuel Kant Baltic Federal University, Nevskogo 14a, 23600 Kaliningrad (Russian Federation); European Synchrotron Radiation Facility, 71 avenue des Martyrs, Grenoble 38043 (France)

2016-07-27

Large-aperture cylindrical refractive lenses were manufactured by laser cutting of single-crystal diamond. Five linear single lenses with apertures of 1 mm and the depth of the structure of 1.2 mm were fabricated and tested at the ESRF ID06 beamline performing the focusing of white-beam synchrotron radiation. Uniform linear focus was stable during hours of exposure, representing such lenses as pre-focusing and collimating devices suitable for the front-end sections of today synchrotron radiation sources.

Focusing of white synchrotron radiation using large-acceptance cylindrical refractive lenses made of single – crystal diamond

International Nuclear Information System (INIS)

Polikarpov, M.; Snigireva, I.; Snigirev, A.

2016-01-01

Large-aperture cylindrical refractive lenses were manufactured by laser cutting of single-crystal diamond. Five linear single lenses with apertures of 1 mm and the depth of the structure of 1.2 mm were fabricated and tested at the ESRF ID06 beamline performing the focusing of white-beam synchrotron radiation. Uniform linear focus was stable during hours of exposure, representing such lenses as pre-focusing and collimating devices suitable for the front-end sections of today synchrotron radiation sources.

POD-Galerkin Model for Incompressible Single-Phase Flow in Porous Media

KAUST Repository

Wang, Yi

2017-01-25

Fast prediction modeling via proper orthogonal decomposition method combined with Galerkin projection is applied to incompressible single-phase fluid flow in porous media. Cases for different configurations of porous media, boundary conditions and problem scales are designed to examine the fidelity and robustness of the model. High precision (relative deviation 1.0 x 10(-4)% similar to 2.3 x 10(-1)%) and large acceleration (speed-up 880 similar to 98454 times) of POD model are found in these cases. Moreover, the computational time of POD model is quite insensitive to the complexity of problems. These results indicate POD model is especially suitable for large-scale complex problems in engineering.

Reaction factoring and bipartite update graphs accelerate the Gillespie Algorithm for large-scale biochemical systems.

Science.gov (United States)

Indurkhya, Sagar; Beal, Jacob

2010-01-06

ODE simulations of chemical systems perform poorly when some of the species have extremely low concentrations. Stochastic simulation methods, which can handle this case, have been impractical for large systems due to computational complexity. We observe, however, that when modeling complex biological systems: (1) a small number of reactions tend to occur a disproportionately large percentage of the time, and (2) a small number of species tend to participate in a disproportionately large percentage of reactions. We exploit these properties in LOLCAT Method, a new implementation of the Gillespie Algorithm. First, factoring reaction propensities allows many propensities dependent on a single species to be updated in a single operation. Second, representing dependencies between reactions with a bipartite graph of reactions and species requires only storage for reactions, rather than the required for a graph that includes only reactions. Together, these improvements allow our implementation of LOLCAT Method to execute orders of magnitude faster than currently existing Gillespie Algorithm variants when simulating several yeast MAPK cascade models.

Electron localization in a mixed-valence diniobium benzene complex.

Science.gov (United States)

Gianetti, Thomas L; Nocton, Grégory; Minasian, Stefan G; Kaltsoyannis, Nikolas; Kilcoyne, A L David; Kozimor, Stosh A; Shuh, David K; Tyliszczak, Tolek; Bergman, Robert G; Arnold, John

2015-02-01

Reaction of the neutral diniobium benzene complex {[Nb(BDI)N t Bu] 2 (μ-C 6 H 6 )} (BDI = N , N '-diisopropylbenzene-β-diketiminate) with Ag[B(C 6 F 5 ) 4 ] results in a single electron oxidation to produce a cationic diniobium arene complex, {[Nb(BDI)N t Bu] 2 (μ-C 6 H 6 )}{B(C 6 F 5 ) 4 }. Investigation of the solid state and solution phase structure using single-crystal X-ray diffraction, cyclic voltammetry, magnetic susceptibility, and multinuclear NMR spectroscopy indicates that the oxidation results in an asymmetric molecule with two chemically inequivalent Nb atoms. Further characterization using density functional theory (DFT) calculations, UV-visible, Nb L 3,2 -edge X-ray absorption near-edge structure (XANES), and EPR spectroscopies supports assignment of a diniobium complex, in which one Nb atom carries a single unpaired electron that is not largely delocalized on the second Nb atom. During the oxidative transformation, one electron is removed from the δ-bonding HOMO, which causes a destabilization of the molecule and formation of an asymmetric product. Subsequent reactivity studies indicate that the oxidized product allows access to metal-based chemistry with substrates that did not exhibit reactivity with the starting neutral complex.

Terbutaline causes immobilization of single β2-adrenergic receptor-ligand complexes in the plasma membrane of living A549 cells as revealed by single-molecule microscopy

Science.gov (United States)

Sieben, Anne; Kaminski, Tim; Kubitscheck, Ulrich; Häberlein, Hanns

2011-02-01

G-protein-coupled receptors are important targets for various drugs. After signal transduction, regulatory processes, such as receptor desensitization and internalization, change the lateral receptor mobility. In order to study the lateral diffusion of β2-adrenergic receptors (β2AR) complexed with fluorescently labeled noradrenaline (Alexa-NA) in plasma membranes of A549 cells, trajectories of single receptor-ligand complexes were monitored using single-particle tracking. We found that a fraction of 18% of all β2ARs are constitutively immobile. About 2/3 of the β2ARs moved with a diffusion constant of D2 = 0.03+/-0.001 μm2/s and about 17% were diffusing five-fold faster (D3 = 0.15+/-0.02 μm2/s). The mobile receptors moved within restricted domains and also showed a discontinuous diffusion behavior. Analysis of the trajectory lengths revealed two different binding durations with τ1 = 77+/-1 ms and τ2 = 388+/-11 ms. Agonistic stimulation of the β2AR-Alexa-NA complexes with 1 μM terbutaline caused immobilization of almost 50% of the receptors within 35 min. Simultaneously, the mean area covered by the mobile receptors decreased significantly. Thus, we demonstrated that agonistic stimulation followed by cell regulatory processes results in a change in β2AR mobility suggesting that different receptor dynamics characterize different receptor states.

Single-particle motion in large-amplitude quadrupole shape transition

International Nuclear Information System (INIS)

Yamada, Kazuya

1991-01-01

The microscopic structure of the single-particle motion for the spherical-deformed transitional nuclei is analysed by using the self-consistent collective-coordinate method (SCC method). The single-particle motion in the moving-frame of reference called the collective vibrating coordinate frame is introduced by the generalized Bogoliubov transformation depending on the collective coordinate. The numerical calculations of the single-particle (quasi-particle) energy level diagrams and their occupation probabilities for the static deformation are carried out for the Sm isotopes. A clear change of the single-particle distribution structure appears in the course of deformation. (author)

Par@Graph - a parallel toolbox for the construction and analysis of large complex climate networks

NARCIS (Netherlands)

Tantet, A.J.J.

2015-01-01

In this paper, we present Par@Graph, a software toolbox to reconstruct and analyze complex climate networks having a large number of nodes (up to at least 106) and edges (up to at least 1012). The key innovation is an efficient set of parallel software tools designed to leverage the inherited hybrid

Deterministic patterned growth of high-mobility large-crystal graphene: a path towards wafer scale integration

Science.gov (United States)

Miseikis, Vaidotas; Bianco, Federica; David, Jérémy; Gemmi, Mauro; Pellegrini, Vittorio; Romagnoli, Marco; Coletti, Camilla

2017-06-01

We demonstrate rapid deterministic (seeded) growth of large single-crystals of graphene by chemical vapour deposition (CVD) utilising pre-patterned copper substrates with chromium nucleation sites. Arrays of graphene single-crystals as large as several hundred microns are grown with a periodicity of up to 1 mm. The graphene is transferred to target substrates using aligned and contamination- free semi-dry transfer. The high quality of the synthesised graphene is confirmed by Raman spectroscopy and transport measurements, demonstrating room-temperature carrier mobility of 21 000 cm2 V-1 s-1 when transferred on top of hexagonal boron nitride. By tailoring the nucleation of large single-crystals according to the desired device geometry, it will be possible to produce complex device architectures based on single-crystal graphene, thus paving the way to the adoption of CVD graphene in wafer-scale fabrication.

Improved Peak Detection and Deconvolution of Native Electrospray Mass Spectra from Large Protein Complexes.

Science.gov (United States)

Lu, Jonathan; Trnka, Michael J; Roh, Soung-Hun; Robinson, Philip J J; Shiau, Carrie; Fujimori, Danica Galonic; Chiu, Wah; Burlingame, Alma L; Guan, Shenheng

2015-12-01

Native electrospray-ionization mass spectrometry (native MS) measures biomolecules under conditions that preserve most aspects of protein tertiary and quaternary structure, enabling direct characterization of large intact protein assemblies. However, native spectra derived from these assemblies are often partially obscured by low signal-to-noise as well as broad peak shapes because of residual solvation and adduction after the electrospray process. The wide peak widths together with the fact that sequential charge state series from highly charged ions are closely spaced means that native spectra containing multiple species often suffer from high degrees of peak overlap or else contain highly interleaved charge envelopes. This situation presents a challenge for peak detection, correct charge state and charge envelope assignment, and ultimately extraction of the relevant underlying mass values of the noncovalent assemblages being investigated. In this report, we describe a comprehensive algorithm developed for addressing peak detection, peak overlap, and charge state assignment in native mass spectra, called PeakSeeker. Overlapped peaks are detected by examination of the second derivative of the raw mass spectrum. Charge state distributions of the molecular species are determined by fitting linear combinations of charge envelopes to the overall experimental mass spectrum. This software is capable of deconvoluting heterogeneous, complex, and noisy native mass spectra of large protein assemblies as demonstrated by analysis of (1) synthetic mononucleosomes containing severely overlapping peaks, (2) an RNA polymerase II/α-amanitin complex with many closely interleaved ion signals, and (3) human TriC complex containing high levels of background noise. Graphical Abstract ᅟ.

Dysphagia is prevalent in patients with CPEO and single, large-scale deletions in mtDNA

DEFF Research Database (Denmark)

Pedersen, Gitte Hedermann; Løkken, Nicoline; Dahlqvist, Julia R.

2017-01-01

Background  The aim of this study was to assess the frequency of subjective and objective dysphagia in patients with chronic progressive external ophthalmoplegia (CPEO) due to single, large-scale deletions (LSDs) of mitochondrial DNA (mtDNA). Methods  Sixteen patients with CPEO and single LSDs...... and single LSDs of mtDNA had a prolonged cold-water test, including one with a PEG-tube, who was unable to perform the test, and nine patients reported subjective swallowing problems (56.3%). All mitochondrial myopathy patients in the control group had a normal duration of the cold-water test.  Conclusions......  The study shows that dysphagia is a common problem in patients with CPEO and LSDs of mtDNA. Dysphagia seems to be progressive with age as abnormal swallowing occurred preferentially in persons ≥ 45 years. The study shows that increased awareness of this symptom should be given to address appropriate...

Single lipid vesicle assay for characterizing single-enzyme kinetics of phospholipid hydrolysis in a complex biological fluid.

Science.gov (United States)

Tabaei, Seyed R; Rabe, Michael; Zetterberg, Henrik; Zhdanov, Vladimir P; Höök, Fredrik

2013-09-25

Imaging of individual lipid vesicles is used to track single-enzyme kinetics of phospholipid hydrolysis. The method is employed to quantify the catalytic activity of phospholipase A2 (PLA2) in both pure and complex biological fluids. The measurements are demonstrated to offer a subpicomolar limit of detection (LOD) of human secretory PLA2 (sPLA2) in up to 1000-fold-diluted cerebrospinal fluid (CSF). An additional new feature provided by the single-enzyme sensitivity is that information about both relative concentration variations of active sPLA2 in CSF and the specific enzymatic activity can be simultaneously obtained. When CSF samples from healthy controls and individuals diagnosed with Alzheimer's disease (AD) are analyzed, the specific enzymatic activity is found to be preserved within 7% in the different CSF samples whereas the enzyme concentration differs by up to 56%. This suggests that the previously reported difference in PLA2 activity in CSF samples from healthy and AD individuals originates from differences in the PLA2 expression level rather than from the enzyme activity. Conventional ensemble averaging methods used to probe sPLA2 activity do not allow one to obtain such information. Together with an improvement in the LOD of at least 1 order of magnitude compared to that of conventional assays, this suggests that the method will become useful in furthering our understanding of the role of PLA2 in health and disease and in detecting the pharmacodynamic effects of PLA2-targeting drug candidates.

The method of arbitrarily large moments to calculate single scale processes in quantum field theory

Directory of Open Access Journals (Sweden)

Johannes Blümlein

2017-08-01

Full Text Available We devise a new method to calculate a large number of Mellin moments of single scale quantities using the systems of differential and/or difference equations obtained by integration-by-parts identities between the corresponding Feynman integrals of loop corrections to physical quantities. These scalar quantities have a much simpler mathematical structure than the complete quantity. A sufficiently large set of moments may even allow the analytic reconstruction of the whole quantity considered, holding in case of first order factorizing systems. In any case, one may derive highly precise numerical representations in general using this method, which is otherwise completely analytic.

Single-Arc IMRT?

International Nuclear Information System (INIS)

Bortfeld, Thomas; Webb, Steve

2009-01-01

The idea of delivering intensity-modulated radiation therapy (IMRT) with a multileaf collimator in a continuous dynamic mode during a single rotation of the gantry has recently gained momentum both in research and industry. In this note we investigate the potential of this Single-Arc IMRT technique at a conceptual level. We consider the original theoretical example case from Brahme et al that got the field of IMRT started. Using analytical methods, we derive deliverable intensity 'landscapes' for Single-Arc as well as standard IMRT and Tomotherapy. We find that Tomotherapy provides the greatest flexibility in shaping intensity landscapes and that it allows one to deliver IMRT in a way that comes close to the ideal case in the transverse plane. Single-Arc and standard IMRT make compromises in different areas. Only in relatively simple cases that do not require substantial intensity modulation will Single-Arc be dosimetrically comparable to Tomotherapy. Compared with standard IMRT, Single-Arc could be dosimetrically superior in certain cases if one is willing to accept the spreading of low dose values over large volumes of normal tissue. In terms of treatment planning, Single-Arc poses a more challenging optimization problem than Tomotherapy or standard IMRT. We conclude that Single-Arc holds potential as an efficient IMRT technique especially for relatively simple cases. In very complex cases, Single-Arc may unduly compromise the quality of the dose distribution, if one tries to keep the treatment time below 2 min or so. As with all IMRT techniques, it is important to explore the tradeoff between plan quality and the efficiency of its delivery carefully for each individual case. (note)

Engineering a large application software project: the controls of the CERN PS accelerator complex

International Nuclear Information System (INIS)

Benincasa, G.P.; Daneels, A.; Heymans, P.; Serre, Ch.

1985-01-01

The CERN PS accelerator complex has been progressively converted to full computer controls without interrupting its full-time operation (more than 6000 hours per year with on average not more than 1% of the total down-time due to controls). The application software amounts to 120 man-years and 450'000 instructions: it compares with other large software projects, also outside the accelerator world: e.g. Skylab's ground support software. This paper outlines the application software structure which takes into account technical requirements and constraints (resulting from the complexity of the process and its operation) and economical and managerial ones. It presents the engineering and management techniques used to promote implementation, testing and commissioning within budget, manpower and time constraints and concludes with experience gained

Clean Transfer of Large Graphene Single Crystals for High-Intactness Suspended Membranes and Liquid Cells.

Science.gov (United States)

Zhang, Jincan; Lin, Li; Sun, Luzhao; Huang, Yucheng; Koh, Ai Leen; Dang, Wenhui; Yin, Jianbo; Wang, Mingzhan; Tan, Congwei; Li, Tianran; Tan, Zhenjun; Liu, Zhongfan; Peng, Hailin

2017-07-01

The atomically thin 2D nature of suspended graphene membranes holds promising in numerous technological applications. In particular, the outstanding transparency to electron beam endows graphene membranes great potential as a candidate for specimen support of transmission electron microscopy (TEM). However, major hurdles remain to be addressed to acquire an ultraclean, high-intactness, and defect-free suspended graphene membrane. Here, a polymer-free clean transfer of sub-centimeter-sized graphene single crystals onto TEM grids to fabricate large-area and high-quality suspended graphene membranes has been achieved. Through the control of interfacial force during the transfer, the intactness of large-area graphene membranes can be as high as 95%, prominently larger than reported values in previous works. Graphene liquid cells are readily prepared by π-π stacking two clean single-crystal graphene TEM grids, in which atomic-scale resolution imaging and temporal evolution of colloid Au nanoparticles are recorded. This facile and scalable production of clean and high-quality suspended graphene membrane is promising toward their wide applications for electron and optical microscopy. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

TTT and PIKK Complex Genes Reverted to Single Copy Following Polyploidization and Retain Function Despite Massive Retrotransposition in Maize.

Science.gov (United States)

Garcia, Nelson; Messing, Joachim

2017-01-01

The TEL2, TTI1, and TTI2 proteins are co-chaperones for heat shock protein 90 (HSP90) to regulate the protein folding and maturation of phosphatidylinositol 3-kinase-related kinases (PIKKs). Referred to as the TTT complex, the genes that encode them are highly conserved from man to maize. TTT complex and PIKK genes exist mostly as single copy genes in organisms where they have been characterized. Members of this interacting protein network in maize were identified and synteny analyses were performed to study their evolution. Similar to other species, there is only one copy of each of these genes in maize which was due to a loss of the duplicated copy created by ancient allotetraploidy. Moreover, the retained copies of the TTT complex and the PIKK genes tolerated extensive retrotransposon insertion in their introns that resulted in increased gene lengths and gene body methylation, without apparent effect in normal gene expression and function. The results raise an interesting question on whether the reversion to single copy was due to selection against deleterious unbalanced gene duplications between members of the complex as predicted by the gene balance hypothesis, or due to neutral loss of extra copies. Uneven alteration of dosage either by adding extra copies or modulating gene expression of complex members is being proposed as a means to investigate whether the data supports the gene balance hypothesis or not.

TTT and PIKK Complex Genes Reverted to Single Copy Following Polyploidization and Retain Function Despite Massive Retrotransposition in Maize

Directory of Open Access Journals (Sweden)

Nelson Garcia

2017-11-01

Full Text Available The TEL2, TTI1, and TTI2 proteins are co-chaperones for heat shock protein 90 (HSP90 to regulate the protein folding and maturation of phosphatidylinositol 3-kinase-related kinases (PIKKs. Referred to as the TTT complex, the genes that encode them are highly conserved from man to maize. TTT complex and PIKK genes exist mostly as single copy genes in organisms where they have been characterized. Members of this interacting protein network in maize were identified and synteny analyses were performed to study their evolution. Similar to other species, there is only one copy of each of these genes in maize which was due to a loss of the duplicated copy created by ancient allotetraploidy. Moreover, the retained copies of the TTT complex and the PIKK genes tolerated extensive retrotransposon insertion in their introns that resulted in increased gene lengths and gene body methylation, without apparent effect in normal gene expression and function. The results raise an interesting question on whether the reversion to single copy was due to selection against deleterious unbalanced gene duplications between members of the complex as predicted by the gene balance hypothesis, or due to neutral loss of extra copies. Uneven alteration of dosage either by adding extra copies or modulating gene expression of complex members is being proposed as a means to investigate whether the data supports the gene balance hypothesis or not.

Structural Complexity and Ecosystem Functions in a Natural Mixed Forest under a Single-Tree Selection Silviculture

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Toshiya Yoshida

2017-11-01

Full Text Available The objective of forest management has become broader, and it is essential to harmonize timber production with conservation of the forest ecosystem. Selection cutting is recognized as a major alternative of clear-cutting, because it can maintain the complexity and heterogeneity of a natural forest; however, its long-term evaluations are limited. This study compared various attributes of stand structures, which are indicators of biodiversity and ecosystem carbon stock between managed and unmanaged blocks (12.6 ha area in total in a natural mixed forest in Hokkaido, the northernmost island of Japan. We found that 30 years’ implementation of single-tree selection did not affect the volume, size structure, species diversity nor spatial distribution of overstory trees in the managed stands. Also, the total carbon stock in the managed stands was almost equal to that of the unmanaged stands. In contrast, several structural attributes and indicator elements that are significant for biodiversity (such as large-diameter live trees, dead trees, cavities, epiphytic bryophytes, and some avian guilds showed marked decrease in the managed stands. We conclude that it is required to leave these structures and elements to some extent for deriving the merit of the management as an alternative silvicultural regime in the region.

Surface growth mechanisms and structural faulting in the growth of large single and spherulitic titanosilicate ETS-4 crystals

Science.gov (United States)

Miraglia, Peter Q.; Yilmaz, Bilge; Warzywoda, Juliusz; Sacco, Albert

2004-10-01

Morphological, surface and crystallographic analyses of titanosilicate ETS-4 products, with diverse habits ranging from spherulitic particles composed of submicron crystallites to large single crystals, are presented. Pole figures revealed that crystal surfaces with a-, b- and c- axes corresponded to , and directions, respectively. Thus, technologically important 8-membered ring pores and titania chains in ETS-4 run along the b-axis of single crystals and terminate at the smallest crystal face. Height of the spiral growth steps observed on {1 0 0} and {0 0 1} surfaces corresponded to the interplanar spacings associated with their crystallographic orientation, and is equivalent to the thickness of building units that form the ETS-4 framework. Data suggest that the more viscous synthesis mixtures, with a large driving force for growth, increased the two- and three-dimensional nucleation, while limiting the transport of nutrients to the growth surface. These conditions increase the tendency for stacking fault formation on {1 0 0} surfaces and small angle branching, which eventually results in spherulitic growth. The growth of high quality ETS-4 single crystals (from less viscous synthesis mixtures) occurred at lower surface nucleation rates. Data suggest that these high quality, large crystals grew due to one-dimensional nucleation at spiral hillocks, and indicate that under these conditions un-faulted growth is preferred.

Gcn4-Mediator Specificity Is Mediated by a Large and Dynamic Fuzzy Protein-Protein Complex.

Science.gov (United States)

Tuttle, Lisa M; Pacheco, Derek; Warfield, Linda; Luo, Jie; Ranish, Jeff; Hahn, Steven; Klevit, Rachel E

2018-03-20

Transcription activation domains (ADs) are inherently disordered proteins that often target multiple coactivator complexes, but the specificity of these interactions is not understood. Efficient transcription activation by yeast Gcn4 requires its tandem ADs and four activator-binding domains (ABDs) on its target, the Mediator subunit Med15. Multiple ABDs are a common feature of coactivator complexes. We find that the large Gcn4-Med15 complex is heterogeneous and contains nearly all possible AD-ABD interactions. Gcn4-Med15 forms via a dynamic fuzzy protein-protein interface, where ADs bind the ABDs in multiple orientations via hydrophobic regions that gain helicity. This combinatorial mechanism allows individual low-affinity and specificity interactions to generate a biologically functional, specific, and higher affinity complex despite lacking a defined protein-protein interface. This binding strategy is likely representative of many activators that target multiple coactivators, as it allows great flexibility in combinations of activators that can cooperate to regulate genes with variable coactivator requirements. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

An Atypical Human Induced Pluripotent Stem Cell Line With a Complex, Stable, and Balanced Genomic Rearrangement Including a Large De Novo 1q Uniparental Disomy

Science.gov (United States)

Steichen, Clara; Maluenda, Jérôme; Tosca, Lucie; Luce, Eléanor; Pineau, Dominique; Dianat, Noushin; Hannoun, Zara; Tachdjian, Gérard; Melki, Judith

2015-01-01

Human induced pluripotent stem cells (hiPSCs) hold great promise for cell therapy through their use as vital tools for regenerative and personalized medicine. However, the genomic integrity of hiPSCs still raises some concern and is one of the barriers limiting their use in clinical applications. Numerous articles have reported the occurrence of aneuploidies, copy number variations, or single point mutations in hiPSCs, and nonintegrative reprogramming strategies have been developed to minimize the impact of the reprogramming process on the hiPSC genome. Here, we report the characterization of an hiPSC line generated by daily transfections of modified messenger RNAs, displaying several genomic abnormalities. Karyotype analysis showed a complex genomic rearrangement, which remained stable during long-term culture. Fluorescent in situ hybridization analyses were performed on the hiPSC line showing that this karyotype is balanced. Interestingly, single-nucleotide polymorphism analysis revealed the presence of a large 1q region of uniparental disomy (UPD), demonstrating for the first time that UPD can occur in a noncompensatory context during nonintegrative reprogramming of normal fibroblasts. PMID:25650439

Complex Security System for Premises Under Conditions of Large Volume of Passenger Traffic

Directory of Open Access Journals (Sweden)

Yakubov Vladimir

2016-01-01

Full Text Available Subsystems of the design of a complex security system for premises under conditions of large volume of passenger traffic are considered. These subsystems provide video- and thermal imaging control, radio wave tomography, and gas analysis. Simultaneous application of all examined variants will essentially increase the probability of timely prevention of dangerous situations with the probability of false alarm as low as possible. It is important that finally, this will provide protection of population and will facilitate the work of intelligence services.

Single neuron computation

CERN Document Server

McKenna, Thomas M; Zornetzer, Steven F

1992-01-01

This book contains twenty-two original contributions that provide a comprehensive overview of computational approaches to understanding a single neuron structure. The focus on cellular-level processes is twofold. From a computational neuroscience perspective, a thorough understanding of the information processing performed by single neurons leads to an understanding of circuit- and systems-level activity. From the standpoint of artificial neural networks (ANNs), a single real neuron is as complex an operational unit as an entire ANN, and formalizing the complex computations performed by real n

Single Photon Avalanche Diodes: Towards the Large Bidimensional Arrays

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Emilio Sciacca

2008-08-01

Full Text Available Single photon detection is one of the most challenging goals of photonics. In recent years, the study of ultra-fast and/or low-intensity phenomena has received renewed attention from the academic and industrial communities. Intense research activity has been focused on bio-imaging applications, bio-luminescence, bio-scattering methods, and, more in general, on several applications requiring high speed operation and high timing resolution. In this paper we present design and characterization of bi-dimensional arrays of a next generation of single photon avalanche diodes (SPADs. Single photon sensitivity, dark noise, afterpulsing and timing resolution of the single SPAD have been examined in several experimental conditions. Moreover, the effects arising from their integration and the readout mode have also been deeply investigated.

Iterative methods for the solution of very large complex symmetric linear systems of equations in electrodynamics

Energy Technology Data Exchange (ETDEWEB)

Clemens, M.; Weiland, T. [Technische Hochschule Darmstadt (Germany)

1996-12-31

In the field of computational electrodynamics the discretization of Maxwell`s equations using the Finite Integration Theory (FIT) yields very large, sparse, complex symmetric linear systems of equations. For this class of complex non-Hermitian systems a number of conjugate gradient-type algorithms is considered. The complex version of the biconjugate gradient (BiCG) method by Jacobs can be extended to a whole class of methods for complex-symmetric algorithms SCBiCG(T, n), which only require one matrix vector multiplication per iteration step. In this class the well-known conjugate orthogonal conjugate gradient (COCG) method for complex-symmetric systems corresponds to the case n = 0. The case n = 1 yields the BiCGCR method which corresponds to the conjugate residual algorithm for the real-valued case. These methods in combination with a minimal residual smoothing process are applied separately to practical 3D electro-quasistatical and eddy-current problems in electrodynamics. The practical performance of the SCBiCG methods is compared with other methods such as QMR and TFQMR.

Single-particle fusion of influenza viruses reveals complex interactions with target membranes

Science.gov (United States)

van der Borg, Guus; Braddock, Scarlett; Blijleven, Jelle S.; van Oijen, Antoine M.; Roos, Wouter H.

2018-05-01

The first step in infection of influenza A virus is contact with the host cell membrane, with which it later fuses. The composition of the target bilayer exerts a complex influence on both fusion efficiency and time. Here, an in vitro, single-particle approach is used to study this effect. Using total internal reflection fluorescence (TIRF) microscopy and a microfluidic flow cell, the hemifusion of single virions is visualized. Hemifusion efficiency and kinetics are studied while altering target bilayer cholesterol content and sialic-acid donor. Cholesterol ratios tested were 0%, 10%, 20%, and 40%. Sialic-acid donors GD1a and GYPA were used. Both cholesterol ratio and sialic-acid donors proved to have a significant effect on hemifusion efficiency. Furthermore, comparison between GD1a and GYPA conditions shows that the cholesterol dependence of the hemifusion time is severely affected by the sialic-acid donor. Only GD1a shows a clear increasing trend in hemifusion efficiency and time with increasing cholesterol concentration of the target bilayer with maximum rates for GD1A and 40% cholesterol. Overall our results show that sialic acid donor and target bilayer composition should be carefully chosen, depending on the desired hemifusion time and efficiency in the experiment.

Rapid Growth of Large Single-Crystalline Graphene via Second Passivation and Multistage Carbon Supply.

Science.gov (United States)

Lin, Li; Sun, Luzhao; Zhang, Jincan; Sun, Jingyu; Koh, Ai Leen; Peng, Hailin; Liu, Zhongfan

2016-06-01

A second passivation and a multistage carbon-source supply (CSS) allow a 50-fold enhancement of the growth rate of large single-crystalline graphene with a record growth rate of 101 μm min(-1) , almost 10 times higher than for pure copper. To this end the CSS is tailored at separate stages of graphene growth on copper foil, combined with an effective suppression of new spontaneous nucleation via second passivation. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Microglomerular Synaptic Complexes in the Sky-Compass Network of the Honeybee Connect Parallel Pathways from the Anterior Optic Tubercle to the Central Complex.

Science.gov (United States)

Held, Martina; Berz, Annuska; Hensgen, Ronja; Muenz, Thomas S; Scholl, Christina; Rössler, Wolfgang; Homberg, Uwe; Pfeiffer, Keram

2016-01-01

While the ability of honeybees to navigate relying on sky-compass information has been investigated in a large number of behavioral studies, the underlying neuronal system has so far received less attention. The sky-compass pathway has recently been described from its input region, the dorsal rim area (DRA) of the compound eye, to the anterior optic tubercle (AOTU). The aim of this study is to reveal the connection from the AOTU to the central complex (CX). For this purpose, we investigated the anatomy of large microglomerular synaptic complexes in the medial and lateral bulbs (MBUs/LBUs) of the lateral complex (LX). The synaptic complexes are formed by tubercle-lateral accessory lobe neuron 1 (TuLAL1) neurons of the AOTU and GABAergic tangential neurons of the central body's (CB) lower division (TL neurons). Both TuLAL1 and TL neurons strongly resemble neurons forming these complexes in other insect species. We further investigated the ultrastructure of these synaptic complexes using transmission electron microscopy. We found that single large presynaptic terminals of TuLAL1 neurons enclose many small profiles (SPs) of TL neurons. The synaptic connections between these neurons are established by two types of synapses: divergent dyads and divergent tetrads. Our data support the assumption that these complexes are a highly conserved feature in the insect brain and play an important role in reliable signal transmission within the sky-compass pathway.

Towards electromechanical computation: An alternative approach to realize complex logic circuits

KAUST Repository

Hafiz, Md Abdullah Al; Kosuru, Lakshmoji; Younis, Mohammad I.

2016-01-01

Electromechanical computing based on micro/nano resonators has recently attracted significant attention. However, full implementation of this technology has been hindered by the difficulty in realizing complex logic circuits. We report here an alternative approach to realize complex logic circuits based on multiple MEMS resonators. As case studies, we report the construction of a single-bit binary comparator, a single-bit 4-to-2 encoder, and parallel XOR/XNOR and AND/NOT logic gates. Toward this, several microresonators are electrically connected and their resonance frequencies are tuned through an electrothermal modulation scheme. The microresonators operating in the linear regime do not require large excitation forces, and work at room temperature and at modest air pressure. This study demonstrates that by reconfiguring the same basic building block, tunable resonator, several essential complex logic functions can be achieved.

Towards electromechanical computation: An alternative approach to realize complex logic circuits

KAUST Repository

Hafiz, M. A. A.

2016-08-18

Electromechanical computing based on micro/nano resonators has recently attracted significant attention. However, full implementation of this technology has been hindered by the difficulty in realizing complex logic circuits. We report here an alternative approach to realize complex logic circuits based on multiple MEMS resonators. As case studies, we report the construction of a single-bit binary comparator, a single-bit 4-to-2 encoder, and parallel XOR/XNOR and AND/NOT logic gates. Toward this, several microresonators are electrically connected and their resonance frequencies are tuned through an electrothermal modulation scheme. The microresonators operating in the linear regime do not require large excitation forces, and work at room temperature and at modest air pressure. This study demonstrates that by reconfiguring the same basic building block, tunable resonator, several essential complex logic functions can be achieved.

Single ICMEs and Complex Transient Structures in the Solar Wind in 2010 - 2011

Science.gov (United States)

Rodkin, D.; Slemzin, V.; Zhukov, A. N.; Goryaev, F.; Shugay, Y.; Veselovsky, I.

2018-05-01

the single-source and multi-source solar wind structures and compared them with the ICME signatures determined from the kinematic and magnetic field parameters of the solar wind. In single-source events, the ion charge state, as a rule, has a one-peak enhancement with an average duration of about one day, which is similar to the mean ICME duration of 1.12 days derived from the Richardson and Cane list. In the multi-source events, the total profile of the ion charge state consists of a sequence of enhancements that is associated with the interaction between the participating streams. On average, the total duration of the complex structures that appear as a result of the CME-CME and CME-HSS interactions as determined from their ion composition is 2.4 days, which is more than twice longer than that of the single-source events.

Single-Sided Deafness: Impact of Cochlear Implantation on Speech Perception in Complex Noise and on Auditory Localization Accuracy.

Science.gov (United States)

Döge, Julia; Baumann, Uwe; Weissgerber, Tobias; Rader, Tobias

2017-12-01

To assess auditory localization accuracy and speech reception threshold (SRT) in complex noise conditions in adult patients with acquired single-sided deafness, after intervention with a cochlear implant (CI) in the deaf ear. Nonrandomized, open, prospective patient series. Tertiary referral university hospital. Eleven patients with late-onset single-sided deafness (SSD) and normal hearing in the unaffected ear, who received a CI. All patients were experienced CI users. Unilateral cochlear implantation. Speech perception was tested in a complex multitalker equivalent noise field consisting of multiple sound sources. Speech reception thresholds in noise were determined in aided (with CI) and unaided conditions. Localization accuracy was assessed in complete darkness. Acoustic stimuli were radiated by multiple loudspeakers distributed in the frontal horizontal plane between -60 and +60 degrees. In the aided condition, results show slightly improved speech reception scores compared with the unaided condition in most of the patients. For 8 of the 11 subjects, SRT was improved between 0.37 and 1.70 dB. Three of the 11 subjects showed deteriorations between 1.22 and 3.24 dB SRT. Median localization error decreased significantly by 12.9 degrees compared with the unaided condition. CI in single-sided deafness is an effective treatment to improve the auditory localization accuracy. Speech reception in complex noise conditions is improved to a lesser extent in 73% of the participating CI SSD patients. However, the absence of true binaural interaction effects (summation, squelch) impedes further improvements. The development of speech processing strategies that respect binaural interaction seems to be mandatory to advance speech perception in demanding listening situations in SSD patients.

Single-molecule exploration of photoprotective mechanisms in light-harvesting complexes

Science.gov (United States)

Yang, Hsiang-Yu; Schlau-Cohen, Gabriela S.; Gwizdala, Michal; Krüger, Tjaart; Xu, Pengqi; Croce, Roberta; van Grondelle, Rienk; Moerner, W. E.

2015-03-01

Plants harvest sunlight by converting light energy to electron flow through the primary events in photosynthesis. One important question is how the light harvesting machinery adapts to fluctuating sunlight intensity. As a result of various regulatory processes, efficient light harvesting and photoprotection are balanced. Some of the biological steps in the photoprotective processes have been extensively studied and physiological regulatory factors have been identified. For example, the effect of lumen pH in changing carotenoid composition has been explored. However, the importance of photophysical dynamics in the initial light-harvesting steps and its relation to photoprotection remain poorly understood. Conformational and excited-state dynamics of multi-chromophore pigment-protein complexes are often difficult to study and limited information can be extracted from ensemble-averaged measurements. To address the problem, we use the Anti-Brownian ELectrokinetic (ABEL) trap to investigate the fluorescence from individual copies of light-harvesting complex II (LHCII), the primary antenna protein in higher plants, in a solution-phase environment. Perturbative surface immobilization or encapsulation schemes are avoided, and therefore the intrinsic dynamics and heterogeneity in the fluorescence of individual proteins are revealed. We perform simultaneous measurements of fluorescence intensity (brightness), excited-state lifetime, and emission spectrum of single trapped proteins. By analyzing the correlated changes between these observables, we identify forms of LHCII with different fluorescence intensities and excited-state lifetimes. The distinct forms may be associated with different energy dissipation mechanisms in the energy transfer chain. Changes of relative populations in response to pH and carotenoid composition are observed, which may extend our understanding of the molecular mechanisms of photoprotection.

Single-molecule conductance of a chemically modified, π-extended tetrathiafulvalene and its charge-transfer complex with F4TCNQ

Directory of Open Access Journals (Sweden)

Raúl García

2015-06-01

Full Text Available We describe the synthesis and single-molecule electrical transport properties of a molecular wire containing a π-extended tetrathiafulvalene (exTTF group and its charge-transfer complex with F4TCNQ. We form single-molecule junctions using the in situ break junction technique using a homebuilt scanning tunneling microscope with a range of conductance between 10 G0 down to 10−7 G0. Within this range we do not observe a clear conductance signature of the neutral parent molecule, suggesting either that its conductance is too low or that it does not form a stable junction. Conversely, we do find a clear conductance signature in the experiments carried out on the charge-transfer complex. Due to the fact we expected this species to have a higher conductance than the neutral molecule, we believe this supports the idea that the conductance of the neutral molecule is very low, below our measurement sensitivity. This idea is further supported by theoretical calculations. To the best of our knowledge, these are the first reported single-molecule conductance measurements on a molecular charge-transfer species.

Rolling cycle amplification based single-color quantum dots–ruthenium complex assembling dyads for homogeneous and highly selective detection of DNA

Energy Technology Data Exchange (ETDEWEB)

Su, Chen; Liu, Yufei; Ye, Tai; Xiang, Xia; Ji, Xinghu; He, Zhike, E-mail: zhkhe@whu.edu.cn

2015-01-01

Graphical abstract: A universal, label-free, homogeneous, highly sensitive, and selective fluorescent biosensor for DNA detection is developed by using rolling-circle amplification (RCA) based single-color quantum dots–ruthenium complex (QDs–Ru) assembling dyads. - Highlights: • The single-color QDs–Ru assembling dyads were applied in homogeneous DNA assay. • This biosensor exhibited high selectivity against base mismatched sequences. • This biosensor could be severed as universal platform for the detection of ssDNA. • This sensor could be used to detect the target in human serum samples. • This DNA sensor had a good selectivity under the interference of other dsDNA. - Abstract: In this work, a new, label-free, homogeneous, highly sensitive, and selective fluorescent biosensor for DNA detection is developed by using rolling-circle amplification (RCA) based single-color quantum dots–ruthenium complex (QDs–Ru) assembling dyads. This strategy includes three steps: (1) the target DNA initiates RCA reaction and generates linear RCA products; (2) the complementary DNA hybridizes with the RCA products to form long double-strand DNA (dsDNA); (3) [Ru(phen){sub 2}(dppx)]{sup 2+} (dppx = 7,8-dimethyldipyrido [3,2-a:2′,3′-c] phenanthroline) intercalates into the long dsDNA with strong fluorescence emission. Due to its strong binding propensity with the long dsDNA, [Ru(phen){sub 2}(dppx)]{sup 2+} is removed from the surface of the QDs, resulting in restoring the fluorescence of the QDs, which has been quenched by [Ru(phen){sub 2}(dppx)]{sup 2+} through a photoinduced electron transfer process and is overlaid with the fluorescence of dsDNA bonded Ru(II) polypyridyl complex (Ru-dsDNA). Thus, high fluorescence intensity is observed, and is related to the concentration of target. This sensor exhibits not only high sensitivity for hepatitis B virus (HBV) ssDNA with a low detection limit (0.5 pM), but also excellent selectivity in the complex matrix. Moreover

A Forward Dynamic Modelling Investigation of Cause-and-Effect Relationships in Single Support Phase of Human Walking

Directory of Open Access Journals (Sweden)

Michael McGrath

2015-01-01

Full Text Available Mathematical gait models often fall into one of two categories: simple and complex. There is a large leap in complexity between model types, meaning the effects of individual gait mechanisms get overlooked. This study investigated the cause-and-effect relationships between gait mechanisms and resulting kinematics and kinetics, using a sequence of mathematical models of increasing complexity. The focus was on sagittal plane and single support only. Starting with an inverted pendulum (IP, extended to include a HAT (head-arms-trunk segment and an actuated hip moment, further complexities were added one-by-one. These were a knee joint, an ankle joint with a static foot, heel rise, and finally a swing leg. The presence of a knee joint and an ankle moment (during foot flat were shown to largely influence the initial peak in the vertical GRF curve. The second peak in this curve was achieved through a combination of heel rise and the presence of a swing leg. Heel rise was also shown to reduce errors in the horizontal GRF prediction in the second half of single support. The swing leg is important for centre-of-mass (CM deceleration in late single support. These findings provide evidence for the specific effects of each gait mechanism.

Complex researches on substantiation of construction and seismic stability of large dams in seismic region

International Nuclear Information System (INIS)

Negmatullaev, S.Kh.; Yasunov, P.A.

2001-01-01

This article is devoted to complex researches on substantiation of construction and seismic stability of large dams (Nurec hydroelectric power station) in seismic region. Geological, seismological, model, and engineering investigations are discussed in this work. At construction of Nurec hydroelectric power station the rich experience is accumulated. This experience can be used in analogous seismically active regions at construction similar hydroelectric power stations.

Trigonal Prismatic Tris-pyridineoximate Transition Metal Complexes: A Cobalt(II) Compound with High Magnetic Anisotropy.

Science.gov (United States)

Pavlov, Alexander A; Savkina, Svetlana A; Belov, Alexander S; Nelyubina, Yulia V; Efimov, Nikolay N; Voloshin, Yan Z; Novikov, Valentin V

2017-06-19

High magnetic anisotropy is a key property of paramagnetic shift tags, which are mostly studied by NMR spectroscopy, and of single molecule magnets, for which magnetometry is usually used. We successfully employed both these methods in analyzing magnetic properties of a series of transition metal complexes, the so-called clathrochelates. A cobalt complex was found to be both a promising paramagnetic shift tag and a single molecule magnet because of it having large axial magnetic susceptibility tensor anisotropy at room temperature (22.5 × 10 -32 m 3 mol -1 ) and a high effective barrier to magnetization reversal (up to 70.5 cm -1 ). The origin of this large magnetic anisotropy is a negative value of zero-field splitting energy that reaches -86 cm -1 according to magnetometry and NMR measurements.

Tetralogy of Fallot and Hypoplastic Left Heart Syndrome – Complex Clinical Phenotypes Meet Complex Genetic Networks

Science.gov (United States)

Lahm, Harald; Schön, Patric; Doppler, Stefanie; Dreßen, Martina; Cleuziou, Julie; Deutsch, Marcus-André; Ewert, Peter; Lange, Rüdiger; Krane, Markus

2015-01-01

In many cases congenital heart disease (CHD) is represented by a complex phenotype and an array of several functional and morphological cardiac disorders. These malformations will be briefly summarized in the first part focusing on two severe CHD phenotypes, hypoplastic left heart syndrome (HLHS) and tetralogy of Fallot (TOF). In most cases of CHD the genetic origin remains largely unknown, though the complexity of the clinical picture strongly argues against a dysregulation which can be attributed to a single candidate gene but rather suggests a multifaceted polygenetic origin with elaborate interactions. Consistent with this idea, genome-wide approaches using whole exome sequencing, comparative sequence analysis of multiplex families to identify de novo mutations and global technologies to identify single nucleotide polymorphisms, copy number variants, dysregulation of the transcriptome and epigenetic variations have been conducted to obtain information about genetic alterations and potential predispositions possibly linked to the occurrence of a CHD phenotype. In the second part of this review we will summarize and discuss the available literature on identified genetic alterations linked to TOF and HLHS. PMID:26069455

Formation of a dinuclear copper(II) complex through the cleavage of CSingle-Bond' name='Single-Bond' value='Single-Bond'/>N bond of 1-benzoyl-3-(pyridin-2-yl)-1H-pyrazole

Energy Technology Data Exchange (ETDEWEB)

Shardin, Rosidah; Pui, Law Kung; Yamin, Bohari M. [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, UKM 43600 Bangi, Selangor (Malaysia); Kassim, Mohammad B. [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, UKM 43600 Bangi, Selangor, Malaysia and Fuel Cell Institute, Universiti Kebangsaan Malaysia, UKM 43600 Bangi, Selangor (Malaysia)

2014-09-03

A simple mononuclear octahedral copper(II) complex was attempted from the reaction of three moles of 1-benzoyl-3-(pyridin-2-yl)-1H-pyrazole and one mole of copper(II) perchlorate hexahydrate in methanol. However, the product of the reaction was confirmed to be a dinuclear copper(II) complex with μ-(3-(pyridin-2-yl)-pyrazolato) and 3-(pyridin-2-yl)-1H-pyrazole ligands attached to each of the Cu(II) centre atom. The copper(II) ion assisted the cleavage of the C{sub benzoyl}Single-Bond' name='Single-Bond' value='Single-Bond'/>N bond afforded a 3-(pyridin-2-yl)-1H-pyrazole molecule. Deprotonation of the 3-(pyridin-2-yl)-1H-pyrazole gave a 3-(pyridin-2-yl)-pyrazolato, which subsequently reacted with the Cu(II) ion to give the (3-(pyridin-2-yl)-pyrazolato)(3-(pyridin-2-yl)-1H-pyrazole)Cu(II) product moiety. The structure of the dinuclear complex was confirmed by x-ray crystallography. The complex crystallized in a monoclinic crystal system with P2(1)/n space group and cell dimensions of a = 12.2029(8) Å, b = 11.4010(7) Å, c = 14.4052(9) Å and β = 102.414(2)°. The compound was further characterized by mass spectrometry, CHN elemental analysis, infrared and UV-visible spectroscopy and the results concurred with the x-ray structure. The presence of d-d transition at 671 nm (ε = 116 dm{sup 3} mol{sup −1} cm{sup −1}) supports the presence of Cu(II) centres.

Large-scale grid-enabled lattice-Boltzmann simulations of complex fluid flow in porous media and under shear

NARCIS (Netherlands)

Harting, J.D.R.; Venturoli, M.; Coveney, P.V.

2004-01-01

Well–designed lattice Boltzmann codes exploit the essentially embarrassingly parallel features of the algorithm and so can be run with considerable efficiency on modern supercomputers. Such scalable codes permit us to simulate the behaviour of increasingly large quantities of complex condensed

Large-Scale Mixed Temperate Forest Mapping at the Single Tree Level using Airborne Laser Scanning

Science.gov (United States)

Scholl, V.; Morsdorf, F.; Ginzler, C.; Schaepman, M. E.

2017-12-01

Monitoring vegetation on a single tree level is critical to understand and model a variety of processes, functions, and changes in forest systems. Remote sensing technologies are increasingly utilized to complement and upscale the field-based measurements of forest inventories. Airborne laser scanning (ALS) systems provide valuable information in the vertical dimension for effective vegetation structure mapping. Although many algorithms exist to extract single tree segments from forest scans, they are often tuned to perform well in homogeneous coniferous or deciduous areas and are not successful in mixed forests. Other methods are too computationally expensive to apply operationally. The aim of this study was to develop a single tree detection workflow using leaf-off ALS data for the canton of Aargau in Switzerland. Aargau covers an area of over 1,400km2 and features mixed forests with various development stages and topography. Forest type was classified using random forests to guide local parameter selection. Canopy height model-based treetop maxima were detected and maintained based on the relationship between tree height and window size, used as a proxy to crown diameter. Watershed segmentation was used to generate crown polygons surrounding each maximum. The location, height, and crown dimensions of single trees were derived from the ALS returns within each polygon. Validation was performed through comparison with field measurements and extrapolated estimates from long-term monitoring plots of the Swiss National Forest Inventory within the framework of the Swiss Federal Institute for Forest, Snow, and Landscape Research. This method shows promise for robust, large-scale single tree detection in mixed forests. The single tree data will aid ecological studies as well as forest management practices. Figure description: Height-normalized ALS point cloud data (top) and resulting single tree segments (bottom) on the Laegeren mountain in Switzerland.

Large-scale synthesis of single-crystalline MgO with bone-like nanostructures

International Nuclear Information System (INIS)

Niu Haixia; Yang Qing; Tang Kaibin; Xie Yi

2006-01-01

Uniform bone-like MgO nanocrystals have been prepared via a solvothermal process using commercial Mg powders as the starting material in the absence of any catalyst or surfactant followed by a subsequent calcination. Field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) measurements indicate that the product consists of a large quantity of bone-like nanocrystals with lengths of 120-200 nm. The widths of these nanocrystals at both ends are in the range of 20-50 nm, which are 3-20 nm wider than those of the middle parts. Explorations of X-ray diffraction (XRD) and selected area electronic diffraction (SAED) exhibit that the product is high-quality cubic single-crystalline nanocrystals. The photoluminescence (PL) measurement suggests that the product has an intensive emission centered at 410 nm, showing that the product has potential application in optical devices. The advantages of our method lie in high yield, the easy availability of the starting materials and permitting large-scale production at low cost. The growth mechanism was proposed to be related with solvent's oxidation in the precursor formation process and following nucleation and mass-transfer in the decomposition of the precursor

Thorium–phosphorus triamidoamine complexes containing Th–P single- and multiple-bond interactions

Science.gov (United States)

Wildman, Elizabeth P.; Balázs, Gábor; Wooles, Ashley J.; Scheer, Manfred; Liddle, Stephen T.

2016-01-01

Despite the burgeoning field of uranium-ligand multiple bonds, analogous complexes involving other actinides remain scarce. For thorium, under ambient conditions only a few multiple bonds to carbon, nitrogen, oxygen, sulfur, selenium and tellurium are reported, and no multiple bonds to phosphorus are known, reflecting a general paucity of synthetic methodologies and also problems associated with stabilising these linkages at the large thorium ion. Here we report structurally authenticated examples of a parent thorium(IV)–phosphanide (Th–PH2), a terminal thorium(IV)–phosphinidene (Th=PH), a parent dithorium(IV)–phosphinidiide (Th–P(H)-Th) and a discrete actinide–phosphido complex under ambient conditions (Th=P=Th). Although thorium is traditionally considered to have dominant 6d-orbital contributions to its bonding, contrasting to majority 5f-orbital character for uranium, computational analyses suggests that the bonding of thorium can be more nuanced, in terms of 5f- versus 6d-orbital composition and also significant involvement of the 7s-orbital and how this affects the balance of 5f- versus 6d-orbital bonding character. PMID:27682617

Recurrence in Benign Paroxysmal Positional Vertigo: A Large, Single-Institution Study.

Science.gov (United States)

Luryi, Alexander L; Lawrence, Juliana; Bojrab, Dennis I; LaRouere, Michael; Babu, Seilesh; Zappia, John; Sargent, Eric W; Chan, Eleanor; Naumann, Ilka; Hong, Robert S; Schutt, Christopher A

2018-04-11

To report rates of recurrence in benign paroxysmal positional vertigo (BPPV) and associated patient and disease factors. Retrospective chart review. Single high-volume otology practice. Patients diagnosed with BPPV from 2007 to 2016 with documented resolution of symptoms. Diagnostic and particle repositioning maneuvers for BPPV. BPPV recurrence, time to recurrence, and ear(s) affected at recurrence. A total of 1,105 patients meeting criteria were identified. Of this population, 37% had recurrence of BPPV in either ear or both ears. Overall same-ear recurrence rate was 28%; 76% of recurrences involved the same ear(s) as initial presentation. Recurrences that occurred after longer disease-free intervals were more likely to involve the opposite ear than early recurrences (p = 0.02). Female sex (40.4% versus 32.7%, p = 0.01) and history of previous BPPV (57.5% versus 32.4%, p diabetes mellitus, and traumatic etiology were not. Approximately, half (56%) of recurrences occurred within 1 year of resolution. A large single-institution study of recurrence in BPPV is presented along with Kaplan-Meier disease-free survival curves. Female sex and history of previous BPPV were associated with increased recurrence, while previously suspected risk factors for recurrence including history of Menière's disease, diabetes, and trauma were not. Remote recurrence is more likely to involve the contralateral ear than early recurrence. These data solidify the expected course of treated BPPV allowing for improved clinical care and patient counseling.

Wall modeled large eddy simulations of complex high Reynolds number flows with synthetic inlet turbulence

International Nuclear Information System (INIS)

Patil, Sunil; Tafti, Danesh

2012-01-01

Highlights: ► Large eddy simulation. ► Wall layer modeling. ► Synthetic inlet turbulence. ► Swirl flows. - Abstract: Large eddy simulations of complex high Reynolds number flows are carried out with the near wall region being modeled with a zonal two layer model. A novel formulation for solving the turbulent boundary layer equation for the effective tangential velocity in a generalized co-ordinate system is presented and applied in the near wall zonal treatment. This formulation reduces the computational time in the inner layer significantly compared to the conventional two layer formulations present in the literature and is most suitable for complex geometries involving body fitted structured and unstructured meshes. The cost effectiveness and accuracy of the proposed wall model, used with the synthetic eddy method (SEM) to generate inlet turbulence, is investigated in turbulent channel flow, flow over a backward facing step, and confined swirling flows at moderately high Reynolds numbers. Predictions are compared with available DNS, experimental LDV data, as well as wall resolved LES. In all cases, there is at least an order of magnitude reduction in computational cost with no significant loss in prediction accuracy.

Therapeutic Assessment of Complex Trauma: A Single-Case Time-Series Study.

Science.gov (United States)

Tarocchi, Anna; Aschieri, Filippo; Fantini, Francesca; Smith, Justin D

2013-06-01

The cumulative effect of repeated traumatic experiences in early childhood incrementally increases the risk of adjustment problems later in life. Surviving traumatic environments can lead to the development of an interrelated constellation of emotional and interpersonal symptoms termed complex posttraumatic stress disorder (CPTSD). Effective treatment of trauma begins with a multimethod psychological assessment and requires the use of several evidence-based therapeutic processes, including establishing a safe therapeutic environment, reprocessing the trauma, constructing a new narrative, and managing emotional dysregulation. Therapeutic Assessment (TA) is a semistructured, brief intervention that uses psychological testing to promote positive change. The case study of Kelly, a middle-aged woman with a history of repeated interpersonal trauma, illustrates delivery of the TA model for CPTSD. Results of this single-case time-series experiment indicate statistically significant symptom improvement as a result of participating in TA. We discuss the implications of these findings for assessing and treating trauma-related concerns, such as CPTSD.

Reaction factoring and bipartite update graphs accelerate the Gillespie Algorithm for large-scale biochemical systems.

Directory of Open Access Journals (Sweden)

Sagar Indurkhya

Full Text Available ODE simulations of chemical systems perform poorly when some of the species have extremely low concentrations. Stochastic simulation methods, which can handle this case, have been impractical for large systems due to computational complexity. We observe, however, that when modeling complex biological systems: (1 a small number of reactions tend to occur a disproportionately large percentage of the time, and (2 a small number of species tend to participate in a disproportionately large percentage of reactions. We exploit these properties in LOLCAT Method, a new implementation of the Gillespie Algorithm. First, factoring reaction propensities allows many propensities dependent on a single species to be updated in a single operation. Second, representing dependencies between reactions with a bipartite graph of reactions and species requires only storage for reactions, rather than the required for a graph that includes only reactions. Together, these improvements allow our implementation of LOLCAT Method to execute orders of magnitude faster than currently existing Gillespie Algorithm variants when simulating several yeast MAPK cascade models.

Reaction Factoring and Bipartite Update Graphs Accelerate the Gillespie Algorithm for Large-Scale Biochemical Systems

Science.gov (United States)

Indurkhya, Sagar; Beal, Jacob

2010-01-01

ODE simulations of chemical systems perform poorly when some of the species have extremely low concentrations. Stochastic simulation methods, which can handle this case, have been impractical for large systems due to computational complexity. We observe, however, that when modeling complex biological systems: (1) a small number of reactions tend to occur a disproportionately large percentage of the time, and (2) a small number of species tend to participate in a disproportionately large percentage of reactions. We exploit these properties in LOLCAT Method, a new implementation of the Gillespie Algorithm. First, factoring reaction propensities allows many propensities dependent on a single species to be updated in a single operation. Second, representing dependencies between reactions with a bipartite graph of reactions and species requires only storage for reactions, rather than the required for a graph that includes only reactions. Together, these improvements allow our implementation of LOLCAT Method to execute orders of magnitude faster than currently existing Gillespie Algorithm variants when simulating several yeast MAPK cascade models. PMID:20066048

The challenge for genetic epidemiologists: how to analyze large numbers of SNPs in relation to complex diseases

NARCIS (Netherlands)

Heidema, A.G.; Boer, J.M.A.; Nagelkerke, N.; Mariman, E.C.M.; A, van der D.L.; Feskens, E.J.M.

2006-01-01

Genetic epidemiologists have taken the challenge to identify genetic polymorphisms involved in the development of diseases. Many have collected data on large numbers of genetic markers but are not familiar with available methods to assess their association with complex diseases. Statistical methods

A Parallel Approach for Frequent Subgraph Mining in a Single Large Graph Using Spark

Directory of Open Access Journals (Sweden)

Fengcai Qiao

2018-02-01

Full Text Available Frequent subgraph mining (FSM plays an important role in graph mining, attracting a great deal of attention in many areas, such as bioinformatics, web data mining and social networks. In this paper, we propose SSiGraM (Spark based Single Graph Mining, a Spark based parallel frequent subgraph mining algorithm in a single large graph. Aiming to approach the two computational challenges of FSM, we conduct the subgraph extension and support evaluation parallel across all the distributed cluster worker nodes. In addition, we also employ a heuristic search strategy and three novel optimizations: load balancing, pre-search pruning and top-down pruning in the support evaluation process, which significantly improve the performance. Extensive experiments with four different real-world datasets demonstrate that the proposed algorithm outperforms the existing GraMi (Graph Mining algorithm by an order of magnitude for all datasets and can work with a lower support threshold.

Large Conization and Laparoendoscopic Single-Port Pelvic Lymphadenectomy in Early-Stage Cervical Cancer for Fertility Preservation

Directory of Open Access Journals (Sweden)

Polat Dursun

2013-01-01

Full Text Available Fertility preservation in early-stage cervical cancer is a hot topic in gynecologic oncology. Although radical vaginal trachelectomy (RVT is suggested as a fertility preserving approach, there are some serious concerns like cervical stenosis, second trimester loss, preterm delivery in survivors, and lack of residual tumor in the majority of the surgical specimens. Therefore, less radical surgical operations have been proposed in early-stage cervical carcinomas. On the other hand, single-incision laparoscopic surgery (SILS is an evolving endoscopic approach for minimal access surgery. In this report, we present a case with early-stage cervical cancer who wishes to preserve fertility. We successfully performed single-port pelvic lymphadenectomy and large conization to preserve fertility potential of the patient. We think that combination of less radical approach like conization and single-port pelvic lymphadenectomy might be less minimally invasive and is still an effective surgical approach in well-selected cases with cervical carcinomas. Incorporation of single-port laparoscopy into the minimally invasive fertility sparing management of the cervical cancer will improve patients outcome with less complications and better cosmesis. Further studies are needed to reach a clear conclusion.

Heritability and demographic analyses in the large isolated population of Val Borbera suggest advantages in mapping complex traits genes.

Directory of Open Access Journals (Sweden)

Michela Traglia

2009-10-01

Full Text Available Isolated populations are a useful resource for mapping complex traits due to shared stable environment, reduced genetic complexity and extended Linkage Disequilibrium (LD compared to the general population. Here we describe a large genetic isolate from the North West Apennines, the mountain range that runs through Italy from the North West Alps to the South.The study involved 1,803 people living in 7 villages of the upper Borbera Valley. For this large population cohort, data from genealogy reconstruction, medical questionnaires, blood, anthropometric and bone status QUS parameters were evaluated. Demographic and epidemiological analyses indicated a substantial genetic component contributing to each trait variation as well as overlapping genetic determinants and family clustering for some traits.The data provide evidence for significant heritability of medical relevant traits that will be important in mapping quantitative traits. We suggest that this population isolate is suitable to identify rare variants associated with complex phenotypes that may be difficult to study in larger but more heterogeneous populations.

ZnS, CdS and HgS Nanoparticles via Alkyl-Phenyl Dithiocarbamate Complexes as Single Source Precursors

OpenAIRE

Onwudiwe, Damian C.; Ajibade, Peter A.

2011-01-01

The synthesis of II-VI semiconductor nanoparticles obtained by the thermolysis of certain group 12 metal complexes as precursors is reported. Thermogravimetric analysis of the single source precursors showed sharp decomposition leading to their respective metal sulfides. The structural and optical properties of the prepared nanoparticles were characterized by means of X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) UV-Vis and photoluminescen...

Single cells from human primary colorectal tumors exhibit polyfunctional heterogeneity in secretions of ELR+ CXC chemokines.

Science.gov (United States)

Adalsteinsson, Viktor A; Tahirova, Narmin; Tallapragada, Naren; Yao, Xiaosai; Campion, Liam; Angelini, Alessandro; Douce, Thomas B; Huang, Cindy; Bowman, Brittany; Williamson, Christina A; Kwon, Douglas S; Wittrup, K Dane; Love, J Christopher

2013-10-01

Cancer is an inflammatory disease of tissue that is largely influenced by the interactions between multiple cell types, secreted factors, and signal transduction pathways. While single-cell sequencing continues to refine our understanding of the clonotypic heterogeneity within tumors, the complex interplay between genetic variations and non-genetic factors ultimately affects therapeutic outcome. Much has been learned through bulk studies of secreted factors in the tumor microenvironment, but the secretory behavior of single cells has been largely uncharacterized. Here we directly profiled the secretions of ELR+ CXC chemokines from thousands of single colorectal tumor and stromal cells, using an array of subnanoliter wells and a technique called microengraving to characterize both the rates of secretion of several factors at once and the numbers of cells secreting each chemokine. The ELR+ CXC chemokines are highly redundant, pro-angiogenic cytokines that signal via the CXCR1 and CXCR2 receptors, influencing tumor growth and progression. We find that human primary colorectal tumor and stromal cells exhibit polyfunctional heterogeneity in the combinations and magnitudes of secretions for these chemokines. In cell lines, we observe similar variance: phenotypes observed in bulk can be largely absent among the majority of single cells, and discordances exist between secretory states measured and gene expression for these chemokines among single cells. Together, these measures suggest secretory states among tumor cells are complex and can evolve dynamically. Most importantly, this study reveals new insight into the intratumoral phenotypic heterogeneity of human primary tumors.

Systematic methods for defining coarse-grained maps in large biomolecules.

Science.gov (United States)

Zhang, Zhiyong

2015-01-01

Large biomolecules are involved in many important biological processes. It would be difficult to use large-scale atomistic molecular dynamics (MD) simulations to study the functional motions of these systems because of the computational expense. Therefore various coarse-grained (CG) approaches have attracted rapidly growing interest, which enable simulations of large biomolecules over longer effective timescales than all-atom MD simulations. The first issue in CG modeling is to construct CG maps from atomic structures. In this chapter, we review the recent development of a novel and systematic method for constructing CG representations of arbitrarily complex biomolecules, in order to preserve large-scale and functionally relevant essential dynamics (ED) at the CG level. In this ED-CG scheme, the essential dynamics can be characterized by principal component analysis (PCA) on a structural ensemble, or elastic network model (ENM) of a single atomic structure. Validation and applications of the method cover various biological systems, such as multi-domain proteins, protein complexes, and even biomolecular machines. The results demonstrate that the ED-CG method may serve as a very useful tool for identifying functional dynamics of large biomolecules at the CG level.

Growing vertical ZnO nanorod arrays within graphite: efficient isolation of large size and high quality single-layer graphene.

Science.gov (United States)

Ding, Ling; E, Yifeng; Fan, Louzhen; Yang, Shihe

2013-07-18

We report a unique strategy for efficiently exfoliating large size and high quality single-layer graphene directly from graphite into DMF dispersions by growing ZnO nanorod arrays between the graphene layers in graphite.

Modern possibilities of radiotherapy in the complex and single treatment of panaris

International Nuclear Information System (INIS)

Kolipiliev, V.; Momchev, M.

1979-01-01

Results are reported of the treatment of 282 patients with different forms of panaris: 39 per cent received radiotherapy alone, in the remaining radiotherapy was combined with surgical management, antibiotics and local treatment. Two different radiotherapy schemes were attempted: 49% of the patients received rather high single (50-80 rad) and total (300-600 rad) doses in the local site at a regimen of superficial (100 kV, 4 mm Al) or deep (180-200 kV, 0.5-1 mm Cu) roentgentherapy, with size of field 4/4 cm or 4/6 cm and 30-40 cm distance. In the remaining 51% of patients radiotherapy was characterized by dynamic fractionation and longer duration of procedures with significantly lower single (30-40 rad) and total (160-320 rad) doses. In recent years the second scheme has been preferred and has gain wide acceptance. Irradiation dose and rate invariably conformed to the type of inflammatory process. Patients with panaritium paronychium and panaritium subcutaneum admitted for treatment in the first few days of development of the digital infection required only several procedures on alternate days to achieve complete cure in a week. In the event of pus collection, 1 or 2 irradiation procedures accelerated abscess formation; this was followed by surgical intervention with postoperative radiotherapy to hasten the granulation process. Treatment of bone-and-joint forms of panaris was complex with initially higher single doses, followed by lower ones, applied up to twice weekly. The following advantages of the method are pointed out: shortening of treatment, respectively of the disability period; easy to perform, painless and practically innocuous manipulation. Complete cure could not be achieved only in advanced, torpid cases. (A.B.)

How Project Managers Really Manage: An Indepth Look at Some Managers of Large, Complex NASA Projects

Science.gov (United States)

Mulenburg, Gerald M.; Impaeilla, Cliff (Technical Monitor)

2000-01-01

This paper reports on a research study by the author that examined ten contemporary National Aeronautics and Space Administration (NASA) complex projects. In-depth interviews with the project managers of these projects provided qualitative data about the inner workings of the project and the methodologies used in establishing and managing the projects. The inclusion of a variety of space, aeronautics, and ground based projects from several different NASA research centers helped to reduce potential bias in the findings toward any one type of project, or technical discipline. The findings address the participants and their individual approaches. The discussion includes possible implications for project managers of other large, complex, projects.

Direct measurement and modulation of single-molecule coordinative bonding forces in a transition metal complex

DEFF Research Database (Denmark)

Hao, Xian; Zhu, Nan; Gschneidtner, Tina

2013-01-01

remain a daunting challenge. Here we demonstrate an interdisciplinary and systematic approach that enables measurement and modulation of the coordinative bonding forces in a transition metal complex. Terpyridine is derived with a thiol linker, facilitating covalent attachment of this ligand on both gold...... substrate surfaces and gold-coated atomic force microscopy tips. The coordination and bond breaking between terpyridine and osmium are followed in situ by electrochemically controlled atomic force microscopy at the single-molecule level. The redox state of the central metal atom is found to have...

Cp2 TiX Complexes for Sustainable Catalysis in Single-Electron Steps.

Science.gov (United States)

Richrath, Ruben B; Olyschläger, Theresa; Hildebrandt, Sven; Enny, Daniel G; Fianu, Godfred D; Flowers, Robert A; Gansäuer, Andreas

2018-04-25

We present a combined electrochemical, kinetic, and synthetic study with a novel and easily accessible class of titanocene catalysts for catalysis in single-electron steps. The tailoring of the electronic properties of our Cp 2 TiX-catalysts that are prepared in situ from readily available Cp 2 TiX 2 is achieved by varying the anionic ligand X. Of the complexes investigated, Cp 2 TiOMs proved to be either equal or substantially superior to the best catalysts developed earlier. The kinetic and thermodynamic properties pertinent to catalysis have been determined. They allow a mechanistic understanding of the subtle interplay of properties required for an efficient oxidative addition and reduction. Therefore, our study highlights that efficient catalysts do not require the elaborate covalent modification of the cyclopentadienyl ligands. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Carcinoma of the large bowel after a single massive dose of radiation in healthy teenagers

International Nuclear Information System (INIS)

Rotmensch, S.; Avigad, I.; Soffer, E.E.; Horowitz, A.; Bar-Meir, S.; Confino, R.; Czerniak, A.; Wolfstein, I.

1986-01-01

Three healthy teenagers were exposed to a single pelvic x-ray irradiation as part of sterilization experiments performed in the Auschwitz concentration camp in 1943. Single and multiple carcinomas of the colon and rectum developed 40 years later in the radiation field. Histologic examination of surgical specimens revealed severe radiation-induced changes in all layers of tumor-adjacent areas. In contrast to previous reports of radiation-induced large bowel cancers, these women had not undergone repeated courses of radiation, had no known co-existing disease that might raise the risk for colonic and rectal malignancies, and had an extremely long and remarkably similar latency period. These cases emphasize the need for long-term surveillance in previously radiated patients. Since thousands of teenagers were subjected to similar sterilization experiments, awareness of this association might help in the early diagnosis of additional cases

Complex antioxidants in a randomized single-blinded study of memory in seniors.

Science.gov (United States)

Summers, William K; Martin, Roy L; Liu, Yimeng; Peña, Bernice; Marsh, Gary M

2018-04-01

Oxidative injury to the brain and aging are theoretical co-causes of Alzheimer's Disease (AD). Amyloid plaques and tangles are then secondary phenomenon. The preclinical state would then be 'normal' elderly. A potent complex antioxidant (antiOx) was tested against a popular one-a-day multivitamin (mV) in a randomized single blind design in 'normal' senior subjects over 6 months. Memory testing was done at baseline, 1, 3, and 6 months. The generalized estimating equation (GEE) approach was used to compare the change score of NLT 100 and 20 WR between two groups over time. Analysis of the antiOx group (30 subjects) demonstrated significant improvement in declarative memory (change score for NLT 100 at month 6 = 6.36 p working memory (change score for 20 WR at month 6 = 3.23, p < 0.0001). A change-score analysis over 6 months suggests possible neurogenesis in the antiOx group. The mV group (33 subjects) had a change score of the NLT 100 and 20WR on the sixth month of 2.20 and 0.32 (p = 0.07, 0.35). A complex antioxidant blend, sold as an over-the-counter (OTC) supplement, can improve memory in elder subjects. Antioxidants may be beneficial in AD and other neurodegerative diseases.

Packaging Concerns and Techniques for Large Devices: Challenges for Complex Electronics

Science.gov (United States)

LaBel, Kenneth A.; Sampson, Michael J.

2010-01-01

NASA is going to have to accept the use of non-hermetic packages for complex devices. There are a large number of packaging options available. Space application subjects the packages to stresses that they were probably not designed for (vacuum for instance). NASA has to find a way of having assurance in the integrity of the packages. There are manufacturers interested in qualifying non-hermetic packages to MIL-PRF-38535 Class V. Government space users are agreed that Class V should be for hermetic packages only. NASA is working on a new Class for non-hermetic packages for M38535 Appendix B, "Class Y". Testing for package integrity will be required but can be package specific as described by a Package Integrity Test Plan. The plan is developed by the manufacturer and approved by DSCC and government space.

Observing the Sun with the Atacama Large Millimeter/submillimeter Array (ALMA): Fast-Scan Single-Dish Mapping

Science.gov (United States)

White, S. M.; Iwai, K.; Phillips, N. M.; Hills, R. E.; Hirota, A.; Yagoubov, P.; Siringo, G.; Shimojo, M.; Bastian, T. S.; Hales, A. S.; Sawada, T.; Asayama, S.; Sugimoto, M.; Marson, R. G.; Kawasaki, W.; Muller, E.; Nakazato, T.; Sugimoto, K.; Brajša, R.; Skokić, I.; Bárta, M.; Kim, S.; Remijan, A. J.; de Gregorio, I.; Corder, S. A.; Hudson, H. S.; Loukitcheva, M.; Chen, B.; De Pontieu, B.; Fleishmann, G. D.; Gary, D. E.; Kobelski, A.; Wedemeyer, S.; Yan, Y.

2017-07-01

The Atacama Large Millimeter/submillimeter Array (ALMA) radio telescope has commenced science observations of the Sun starting in late 2016. Since the Sun is much larger than the field of view of individual ALMA dishes, the ALMA interferometer is unable to measure the background level of solar emission when observing the solar disk. The absolute temperature scale is a critical measurement for much of ALMA solar science, including the understanding of energy transfer through the solar atmosphere, the properties of prominences, and the study of shock heating in the chromosphere. In order to provide an absolute temperature scale, ALMA solar observing will take advantage of the remarkable fast-scanning capabilities of the ALMA 12 m dishes to make single-dish maps of the full Sun. This article reports on the results of an extensive commissioning effort to optimize the mapping procedure, and it describes the nature of the resulting data. Amplitude calibration is discussed in detail: a path that uses the two loads in the ALMA calibration system as well as sky measurements is described and applied to commissioning data. Inspection of a large number of single-dish datasets shows significant variation in the resulting temperatures, and based on the temperature distributions, we derive quiet-Sun values at disk center of 7300 K at λ = 3 mm and 5900 K at λ = 1.3 mm. These values have statistical uncertainties of about 100 K, but systematic uncertainties in the temperature scale that may be significantly larger. Example images are presented from two periods with very different levels of solar activity. At a resolution of about 25'', the 1.3 mm wavelength images show temperatures on the disk that vary over about a 2000 K range. Active regions and plages are among the hotter features, while a large sunspot umbra shows up as a depression, and filament channels are relatively cool. Prominences above the solar limb are a common feature of the single-dish images.

Rational design of single-ion magnets and spin qubits based on mononuclear lanthanoid complexes.

Science.gov (United States)

Baldoví, José J; Cardona-Serra, Salvador; Clemente-Juan, Juan M; Coronado, Eugenio; Gaita-Ariño, Alejandro; Palii, Andrew

2012-11-19

Here we develop a general approach to calculating the energy spectrum and the wave functions of the low-lying magnetic levels of a lanthanoid ion submitted to the crystal field created by the surrounding ligands. This model allows us to propose general criteria for the rational design of new mononuclear lanthanoid complexes behaving as single-molecule magnets (SMMs) or acting as robust spin qubits. Three typical environments exhibited by these metal complexes are considered, namely, (a) square antiprism, (b) triangular dodecahedron, and (c) trigonal prism. The developed model is used to explain the properties of some representative examples showing these geometries. Key questions in this area, such as the chemical tailoring of the superparamagnetic energy barrier, tunneling gap, or spin relaxation time, are discussed. Finally, in order to take into account delocalization and/or covalent effects of the ligands, this point-charge model is complemented with ab initio calculations, which provide accurate information on the charge distribution around the metal, allowing for an explanation of the SMM behavior displayed by some sandwich-type organometallic compounds.

ESR study of irradiated single crystals of the cocrystalline complex of cytidine: Salicylic acid

International Nuclear Information System (INIS)

Close, D.M.; Sagstuen, E.

1983-01-01

Irradiation at 77 K of single crystals of the 1:1 complex of cytidine and salicylic acid produces a phenoxyl radical formed by oxidation of the salicylic acid. Anisotropic hyperfine coupling tensors have been determined for this radical which are associated with the para and ortho hydrogens. No cytidine oxidation products (alkoxy or hydroxyalkyl radicals) were observed at 77 K. Following the decay of the phenoxyl radical at room temperature, four radicals were detected. These include the cytosine 5--yl and 6--yl radicals, formed by H addition to the cytosine ring, and an anisotropic doublet. By UV irradiation at room temperature, it is possible to convert a significant fraction of 6-yl radicals into 5-yl radicals. Hyperfine coupling and g tensors determined for the anisotropic doublet indicate that this radical is formed in the C/sub 1'/-C/sub 2'/ region of the sugar moiety. These results indicate a shift in radiation damage away from the salicylic acid upon warming, and show that the radiation chemistry of the cocrystalline complex is different from that of the isolated bases

Three-Year Major Clinical Outcomes of Angiography-Guided Single Stenting Technique in Non-Complex Left Main Coronary Artery Diseases.

Science.gov (United States)

Kim, Yong Hoon; Her, Ae-Young; Rha, Seung-Woon; Choi, Byoung Geol; Shim, Minsuk; Choi, Se Yeon; Byun, Jae Kyeong; Li, Hu; Kim, Woohyeun; Kang, Jun Hyuk; Choi, Jah Yeon; Park, Eun Jin; Park, Sung Hun; Lee, Sunki; Na, Jin Oh; Choi, Cheol Ung; Lim, Hong Euy; Kim, Eung Ju; Park, Chang Gyu; Seo, Hong Seog; Oh, Dong Joo

2017-10-12

There is limited long-term comparative clinical outcome data concerning angiography- versus intravascular ultrasound (IVUS)-guided percutaneous coronary intervention (PCI) in non-complex left main coronary artery (LMCA) disease treated with the single stenting technique in the drug-eluting stent (DES) era.The aim of this study was to investigate whether angiography-guided stenting is comparable to IVUS-guided stenting during 3-year clinical follow-up periods in patients with non-complex LM disease treated with the single stenting technique.A total of 196 patients treated with either angiography-guided (n = 74) or IVUS-guided (n = 122) PCI were included. The primary outcome was the occurrence of major adverse cardiac events (MACE) defined as total death, non-fatal myocardial infarction (MI), target lesion revascularization (TLR), target vessel revascularization (TVR), and non-target vessel revascularization (Non-TVR). To adjust for any potential confounders, propensity score (PS) adjusted analysis was performed.During 3-year follow-up, the PS adjusted Cox-proportional hazard ratio (HR) was not significantly different between the two groups for total death, cardiac death, and MI. Also, TLR and the combined rates of TVR and non-TVR were not significantly different. Finally, MACE was not significantly different between the two groups (HR: 0.63, 95% Confidence interval (CI): 0.33-1.17; P = 0.149).Angiography-guided PCI for non-complex LMCA diseases treated with the single stenting technique showed comparable results compared with IVUS-guided PCI in reducing clinical events during 3-year clinical follow-up in the DES era. Although IVUS guided PCI is the ideal strategy, angiography-guided PCI can be an option for LMCA PCI in some selected cases.

SPECTROSCOPIC STUDY OF THE N159/N160 COMPLEX IN THE LARGE MAGELLANIC CLOUD

International Nuclear Information System (INIS)

Farina, Cecilia; Bosch, Guillermo L.; Morrell, Nidia I.; Barba, Rodolfo H.; Walborn, Nolan R.

2009-01-01

We present a spectroscopic study of the N159/N160 massive star-forming region south of 30 Doradus in the Large Magellanic Cloud, classifying a total of 189 stars in the field of the complex. Most of them belong to O and early B spectral classes; we have also found some uncommon and very interesting spectra, including members of the Onfp class, a Be P Cygni star, and some possible multiple systems. Using spectral types as broad indicators of evolutionary stages, we considered the evolutionary status of the region as a whole. We infer that massive stars at different evolutionary stages are present throughout the region, favoring the idea of a common time for the origin of recent star formation in the N159/N160 complex as a whole, while sequential star formation at different rates is probably present in several subregions.

Single-molecule chemical reactions on DNA origami

DEFF Research Database (Denmark)

Voigt, Niels Vinther; Tørring, Thomas; Rotaru, Alexandru

2010-01-01

as templates for building materials with new functional properties. Relatively large nanocomponents such as nanoparticles and biomolecules can also be integrated into DNA nanostructures and imaged. Here, we show that chemical reactions with single molecules can be performed and imaged at a local position...... on a DNA origami scaffold by atomic force microscopy. The high yields and chemoselectivities of successive cleavage and bond-forming reactions observed in these experiments demonstrate the feasibility of post-assembly chemical modification of DNA nanostructures and their potential use as locally......DNA nanotechnology and particularly DNA origami, in which long, single-stranded DNA molecules are folded into predetermined shapes, can be used to form complex self-assembled nanostructures. Although DNA itself has limited chemical, optical or electronic functionality, DNA nanostructures can serve...

Burnout of pulverized biomass particles in large scale boiler - Single particle model approach

Energy Technology Data Exchange (ETDEWEB)

Saastamoinen, Jaakko; Aho, Martti; Moilanen, Antero [VTT Technical Research Centre of Finland, Box 1603, 40101 Jyvaeskylae (Finland); Soerensen, Lasse Holst [ReaTech/ReAddit, Frederiksborgsveij 399, Niels Bohr, DK-4000 Roskilde (Denmark); Clausen, Soennik [Risoe National Laboratory, DK-4000 Roskilde (Denmark); Berg, Mogens [ENERGI E2 A/S, A.C. Meyers Vaenge 9, DK-2450 Copenhagen SV (Denmark)

2010-05-15

Burning of coal and biomass particles are studied and compared by measurements in an entrained flow reactor and by modelling. The results are applied to study the burning of pulverized biomass in a large scale utility boiler originally planned for coal. A simplified single particle approach, where the particle combustion model is coupled with one-dimensional equation of motion of the particle, is applied for the calculation of the burnout in the boiler. The particle size of biomass can be much larger than that of coal to reach complete burnout due to lower density and greater reactivity. The burner location and the trajectories of the particles might be optimised to maximise the residence time and burnout. (author)

Retention of habitat complexity minimizes disassembly of reef fish communities following disturbance: a large-scale natural experiment.

Directory of Open Access Journals (Sweden)

Michael J Emslie

Full Text Available High biodiversity ecosystems are commonly associated with complex habitats. Coral reefs are highly diverse ecosystems, but are under increasing pressure from numerous stressors, many of which reduce live coral cover and habitat complexity with concomitant effects on other organisms such as reef fishes. While previous studies have highlighted the importance of habitat complexity in structuring reef fish communities, they employed gradient or meta-analyses which lacked a controlled experimental design over broad spatial scales to explicitly separate the influence of live coral cover from overall habitat complexity. Here a natural experiment using a long term (20 year, spatially extensive (∼ 115,000 kms(2 dataset from the Great Barrier Reef revealed the fundamental importance of overall habitat complexity for reef fishes. Reductions of both live coral cover and habitat complexity had substantial impacts on fish communities compared to relatively minor impacts after major reductions in coral cover but not habitat complexity. Where habitat complexity was substantially reduced, species abundances broadly declined and a far greater number of fish species were locally extirpated, including economically important fishes. This resulted in decreased species richness and a loss of diversity within functional groups. Our results suggest that the retention of habitat complexity following disturbances can ameliorate the impacts of coral declines on reef fishes, so preserving their capacity to perform important functional roles essential to reef resilience. These results add to a growing body of evidence about the importance of habitat complexity for reef fishes, and represent the first large-scale examination of this question on the Great Barrier Reef.

Laparoendoscopic Single-Site Surgery (LESS for a Large Ovarian Tumour: First Clinical Case Report

Directory of Open Access Journals (Sweden)

Yao Dong Chua

2011-01-01

Main Outcome Measure(s. Conversion to standard laparoscopic technique or laparotomy, estimated blood loss, operative time , extent of scarring, occurrence of intra- and perioperative surgical complications, technical adequacy, and clinical outcome. Result(s. No conversion to standard laparoscopic technique or laparotomy, and no intraoperative or postoperative complications were observed. Total operative time was 99 minutes. The patient was discharged home on postoperative day one. Conclusion(s. Laparoendoscopic single-site bilateral salpingo-oophorectomy of a large ovarian tumour is feasible with standard laparoscopic instruments. It is safe and effective, with good results in terms of excellent cosmesis and minimal postoperative pain.

Expanded Large-Scale Forcing Properties Derived from the Multiscale Data Assimilation System and Its Application to Single-Column Models

Science.gov (United States)

Feng, S.; Li, Z.; Liu, Y.; Lin, W.; Toto, T.; Vogelmann, A. M.; Fridlind, A. M.

2013-12-01

We present an approach to derive large-scale forcing that is used to drive single-column models (SCMs) and cloud resolving models (CRMs)/large eddy simulation (LES) for evaluating fast physics parameterizations in climate models. The forcing fields are derived by use of a newly developed multi-scale data assimilation (MS-DA) system. This DA system is developed on top of the NCEP Gridpoint Statistical Interpolation (GSI) System and is implemented in the Weather Research and Forecasting (WRF) model at a cloud resolving resolution of 2 km. This approach has been applied to the generation of large scale forcing for a set of Intensive Operation Periods (IOPs) over the Atmospheric Radiation Measurement (ARM) Climate Research Facility's Southern Great Plains (SGP) site. The dense ARM in-situ observations and high-resolution satellite data effectively constrain the WRF model. The evaluation shows that the derived forcing displays accuracies comparable to the existing continuous forcing product and, overall, a better dynamic consistency with observed cloud and precipitation. One important application of this approach is to derive large-scale hydrometeor forcing and multiscale forcing, which is not provided in the existing continuous forcing product. It is shown that the hydrometeor forcing poses an appreciable impact on cloud and precipitation fields in the single-column model simulations. The large-scale forcing exhibits a significant dependency on domain-size that represents SCM grid-sizes. Subgrid processes often contribute a significant component to the large-scale forcing, and this contribution is sensitive to the grid-size and cloud-regime.

Underestimated effect sizes in GWAS: fundamental limitations of single SNP analysis for dichotomous phenotypes.

Directory of Open Access Journals (Sweden)

Sven Stringer

Full Text Available Complex diseases are often highly heritable. However, for many complex traits only a small proportion of the heritability can be explained by observed genetic variants in traditional genome-wide association (GWA studies. Moreover, for some of those traits few significant SNPs have been identified. Single SNP association methods test for association at a single SNP, ignoring the effect of other SNPs. We show using a simple multi-locus odds model of complex disease that moderate to large effect sizes of causal variants may be estimated as relatively small effect sizes in single SNP association testing. This underestimation effect is most severe for diseases influenced by numerous risk variants. We relate the underestimation effect to the concept of non-collapsibility found in the statistics literature. As described, continuous phenotypes generated with linear genetic models are not affected by this underestimation effect. Since many GWA studies apply single SNP analysis to dichotomous phenotypes, previously reported results potentially underestimate true effect sizes, thereby impeding identification of true effect SNPs. Therefore, when a multi-locus model of disease risk is assumed, a multi SNP analysis may be more appropriate.

Analysis of free-surface flows through energy considerations: Single-phase versus two-phase modeling.

Science.gov (United States)

Marrone, Salvatore; Colagrossi, Andrea; Di Mascio, Andrea; Le Touzé, David

2016-05-01

The study of energetic free-surface flows is challenging because of the large range of interface scales involved due to multiple fragmentations and reconnections of the air-water interface with the formation of drops and bubbles. Because of their complexity the investigation of such phenomena through numerical simulation largely increased during recent years. Actually, in the last decades different numerical models have been developed to study these flows, especially in the context of particle methods. In the latter a single-phase approximation is usually adopted to reduce the computational costs and the model complexity. While it is well known that the role of air largely affects the local flow evolution, it is still not clear whether this single-phase approximation is able to predict global flow features like the evolution of the global mechanical energy dissipation. The present work is dedicated to this topic through the study of a selected problem simulated with both single-phase and two-phase models. It is shown that, interestingly, even though flow evolutions are different, energy evolutions can be similar when including or not the presence of air. This is remarkable since, in the problem considered, with the two-phase model about half of the energy is lost in the air phase while in the one-phase model the energy is mainly dissipated by cavity collapses.

Task Phase Recognition for Highly Mobile Workers in Large Building Complexes

DEFF Research Database (Denmark)

Stisen, Allan; Mathisen, Andreas; Krogh, Søren

2016-01-01

requirements on the accuracy of the indoor positioning, and thus come with low deployment and maintenance effort in real-world settings. We evaluated the proposed methods in a large hospital complex, where the highly mobile workers were recruited among the non-clinical workforce. The evaluation is based......-scale indoor work environments, namely from a WiFi infrastructure providing coarse grained indoor positioning, from inertial sensors in the workers’ mobile phones, and from a task management system yielding information about the scheduled tasks’ start and end locations. The methods presented have low...... on manually labelled real-world data collected over 4 days of regular work life of the mobile workforce. The collected data yields 83 tasks in total involving 8 different orderlies from a major university hospital with a building area of 160, 000 m2. The results show that the proposed methods can distinguish...

Overview of ESO Large Single Dish Study

Science.gov (United States)

Testi, Leonardo

2018-01-01

In this talk I will briefly summarize the motivation, methodology and outcome of the ESO Submm Single Dish Strategy WG. The WG was established by the ESO Director for Science and completed its work at the end of 2015. I will summarize the status of the report recommendations, which, among other things, led to the organization of the AtLAST workshop.

Data mining in large sets of complex data

CERN Document Server

Cordeiro, Robson L F; Júnior, Caetano Traina

2013-01-01

The amount and the complexity of the data gathered by current enterprises are increasing at an exponential rate. Consequently, the analysis of Big Data is nowadays a central challenge in Computer Science, especially for complex data. For example, given a satellite image database containing tens of Terabytes, how can we find regions aiming at identifying native rainforests, deforestation or reforestation? Can it be made automatically? Based on the work discussed in this book, the answers to both questions are a sound "yes", and the results can be obtained in just minutes. In fact, results that

Stability and Hopf Bifurcation of Fractional-Order Complex-Valued Single Neuron Model with Time Delay

Science.gov (United States)

Wang, Zhen; Wang, Xiaohong; Li, Yuxia; Huang, Xia

2017-12-01

In this paper, the problems of stability and Hopf bifurcation in a class of fractional-order complex-valued single neuron model with time delay are addressed. With the help of the stability theory of fractional-order differential equations and Laplace transforms, several new sufficient conditions, which ensure the stability of the system are derived. Taking the time delay as the bifurcation parameter, Hopf bifurcation is investigated and the critical value of the time delay for the occurrence of Hopf bifurcation is determined. Finally, two representative numerical examples are given to show the effectiveness of the theoretical results.

Noise characteristics of single-walled carbon nanotube network transistors

International Nuclear Information System (INIS)

Kim, Un Jeong; Kim, Kang Hyun; Kim, Kyu Tae; Min, Yo-Sep; Park, Wanjun

2008-01-01

The noise characteristics of randomly networked single-walled carbon nanotubes grown directly by plasma enhanced chemical vapor deposition (PECVD) are studied with field effect transistors (FETs). Due to the geometrical complexity of nanotube networks in the channel area and the large number of tube-tube/tube-metal junctions, the inverse frequency, 1/f, dependence of the noise shows a similar level to that of a single single-walled carbon nanotube transistor. Detailed analysis is performed with the parameters of number of mobile carriers and mobility in the different environment. This shows that the change in the number of mobile carriers resulting in the mobility change due to adsorption and desorption of gas molecules (mostly oxygen molecules) to the tube surface is a key factor in the 1/f noise level for carbon nanotube network transistors

Building a pseudo-atomic model of the anaphase-promoting complex

International Nuclear Information System (INIS)

Kulkarni, Kiran; Zhang, Ziguo; Chang, Leifu; Yang, Jing; Fonseca, Paula C. A. da; Barford, David

2013-01-01

This article describes an example of molecular replacement in which atomic models are used to interpret electron-density maps determined using single-particle electron-microscopy data. The anaphase-promoting complex (APC/C) is a large E3 ubiquitin ligase that regulates progression through specific stages of the cell cycle by coordinating the ubiquitin-dependent degradation of cell-cycle regulatory proteins. Depending on the species, the active form of the APC/C consists of 14–15 different proteins that assemble into a 20-subunit complex with a mass of approximately 1.3 MDa. A hybrid approach of single-particle electron microscopy and protein crystallography of individual APC/C subunits has been applied to generate pseudo-atomic models of various functional states of the complex. Three approaches for assigning regions of the EM-derived APC/C density map to specific APC/C subunits are described. This information was used to dock atomic models of APC/C subunits, determined either by protein crystallography or homology modelling, to specific regions of the APC/C EM map, allowing the generation of a pseudo-atomic model corresponding to 80% of the entire complex

Multi-physics modeling of single/multiple-track defect mechanisms in electron beam selective melting

International Nuclear Information System (INIS)

Yan, Wentao; Ge, Wenjun; Qian, Ya; Lin, Stephen; Zhou, Bin; Liu, Wing Kam; Lin, Feng; Wagner, Gregory J.

2017-01-01

Metallic powder bed-based additive manufacturing technologies have many promising attributes. The single track acts as one fundamental building unit, which largely influences the final product quality such as the surface roughness and dimensional accuracy. A high-fidelity powder-scale model is developed to predict the detailed formation processes of single/multiple-track defects, including the balling effect, single track nonuniformity and inter-track voids. These processes are difficult to observe in experiments; previous studies have proposed different or even conflicting explanations. Our study clarifies the underlying formation mechanisms, reveals the influence of key factors, and guides the improvement of fabrication quality of single tracks. Additionally, the manufacturing processes of multiple tracks along S/Z-shaped scan paths with various hatching distance are simulated to further understand the defects in complex structures. The simulations demonstrate that the hatching distance should be no larger than the width of the remelted region within the substrate rather than the width of the melted region within the powder layer. Thus, single track simulations can provide valuable insight for complex structures.

Detecting gait abnormalities after concussion or mild traumatic brain injury: A systematic review of single-task, dual-task, and complex gait.

Science.gov (United States)

Fino, Peter C; Parrington, Lucy; Pitt, Will; Martini, Douglas N; Chesnutt, James C; Chou, Li-Shan; King, Laurie A

2018-05-01

While a growing number of studies have investigated the effects of concussion or mild traumatic brain injury (mTBI) on gait, many studies use different experimental paradigms and outcome measures. The path for translating experimental studies for objective clinical assessments of gait is unclear. This review asked 2 questions: 1) is gait abnormal after concussion/mTBI, and 2) what gait paradigms (single-task, dual-task, complex gait) detect abnormalities after concussion. Data sources included MEDLINE/PubMed, Scopus, Web of Science, and Cumulative Index to Nursing and Allied Health Literature (CINAHL) accessed on March 14, 2017. Original research articles reporting gait outcomes in people with concussion or mTBI were included. Studies of moderate, severe, or unspecified TBI, and studies without a comparator were excluded. After screening 233 articles, 38 studies were included and assigned to one or more sections based on the protocol and reported outcomes. Twenty-six articles reported single-task simple gait outcomes, 24 reported dual-task simple gait outcomes, 21 reported single-task complex gait outcomes, and 10 reported dual-task complex gait outcomes. Overall, this review provides evidence for two conclusions: 1) gait is abnormal acutely after concussion/mTBI but generally resolves over time; and 2) the inconsistency of findings, small sample sizes, and small number of studies examining homogenous measures at the same time-period post-concussion highlight the need for replication across independent populations and investigators. Future research should concentrate on dual-task and complex gait tasks, as they showed promise for detecting abnormal locomotor function outside of the acute timeframe. Additionally, studies should provide detailed demographic and clinical characteristics to enable more refined comparisons across studies. Copyright © 2018 Elsevier B.V. All rights reserved.

Fast and Accurate Identification of Cross-Linked Peptides for the Structural Analysis of Large Protein Complexes and Elucidation of Interaction Networks. / Tahir, Salman; Bukowski-Wills, Jimi-Carlo; Rasmussen, Morten; Rappsilber, Juri

DEFF Research Database (Denmark)

Rasmussen, Morten

to investigate protein structure and protein-protein interactions. When applied to single proteins or small purified protein complexes, this methodology works well. However certain challenges arise when applied to more complex samples. One of the main problems is the combinatorial increase in the search space...... simplify a spectrum because we remove all peaks that are accounted for by the fragmentation of peptide one. This approach is highly sensitive and scales well as revealed by searching our data of synthetic cross-links against a large sequence database. Currently, against a protein database of >1300 proteins...... a spectrum is searched in 0.35 seconds - a vast improvement when compared to the exhaustive search method of combining every potential cross-link for each spectrum(60 hours). In fact the search time is comparable, if not better, than existing linear search engines. Furthermore, we auto-validate the results...

Three-dimensional coupled Monte Carlo-discrete ordinates computational scheme for shielding calculations of large and complex nuclear facilities

International Nuclear Information System (INIS)

Chen, Y.; Fischer, U.

2005-01-01

Shielding calculations of advanced nuclear facilities such as accelerator based neutron sources or fusion devices of the tokamak type are complicated due to their complex geometries and their large dimensions, including bulk shields of several meters thickness. While the complexity of the geometry in the shielding calculation can be hardly handled by the discrete ordinates method, the deep penetration of radiation through bulk shields is a severe challenge for the Monte Carlo particle transport technique. This work proposes a dedicated computational scheme for coupled Monte Carlo-Discrete Ordinates transport calculations to handle this kind of shielding problems. The Monte Carlo technique is used to simulate the particle generation and transport in the target region with both complex geometry and reaction physics, and the discrete ordinates method is used to treat the deep penetration problem in the bulk shield. The coupling scheme has been implemented in a program system by loosely integrating the Monte Carlo transport code MCNP, the three-dimensional discrete ordinates code TORT and a newly developed coupling interface program for mapping process. Test calculations were performed with comparison to MCNP solutions. Satisfactory agreements were obtained between these two approaches. The program system has been chosen to treat the complicated shielding problem of the accelerator-based IFMIF neutron source. The successful application demonstrates that coupling scheme with the program system is a useful computational tool for the shielding analysis of complex and large nuclear facilities. (authors)

RESEARCH ON COMPLEX, LARGE INDUSTRIAL PROJECTS IN TRANSNATIONAL ENVIRONMENT

Directory of Open Access Journals (Sweden)

Florin POPESCU

2016-12-01

Full Text Available More and more projects from different industrial sectors developed in transnational environment are becoming more characterized as "complex". In recent years, there has been much discussion and controversy about the complexity of the projects, and, despite what has been written and said in various papers, journals and professional conferences, more confusion than clarification was created, complexity of projects being interpreted differently from one author to another. Most of the literature studied is based on linear, analytical and rational approach, focusing on the size of project management planning and control and actually less on projects that are characterized as taking place and grow into a dynamic socio-human environment in a continuous change. This study represents a critical review of existing theoretical models found in literature, highlighting their limitations. The output of this literature study represents an integration of different approaches concerning complexity under one umbrella to provide a common understanding of the evolution of this concept.

Dynamics of water around the complex structures formed between the KH domains of far upstream element binding protein and single-stranded DNA molecules

Energy Technology Data Exchange (ETDEWEB)

Chakraborty, Kaushik; Bandyopadhyay, Sanjoy, E-mail: sanjoy@chem.iitkgp.ernet.in [Molecular Modeling Laboratory, Department of Chemistry, Indian Institute of Technology, Kharagpur 721302 (India)

2015-07-28

Single-stranded DNA (ss-DNA) binding proteins specifically bind to the single-stranded regions of the DNA and protect it from premature annealing, thereby stabilizing the DNA structure. We have carried out atomistic molecular dynamics simulations of the aqueous solutions of two DNA binding K homology (KH) domains (KH3 and KH4) of the far upstream element binding protein complexed with two short ss-DNA segments. Attempts have been made to explore the influence of the formation of such complex structures on the microscopic dynamics and hydrogen bond properties of the interfacial water molecules. It is found that the water molecules involved in bridging the ss-DNA segments and the protein domains form a highly constrained thin layer with extremely retarded mobility. These water molecules play important roles in freezing the conformational oscillations of the ss-DNA oligomers and thereby forming rigid complex structures. Further, it is demonstrated that the effect of complexation on the slow long-time relaxations of hydrogen bonds at the interface is correlated with hindered motions of the surrounding water molecules. Importantly, it is observed that the highly restricted motions of the water molecules bridging the protein and the DNA components in the complexed forms originate from more frequent hydrogen bond reformations.

Genetic and biochemical identification of a novel single-stranded DNA binding complex in Haloferax volcanii

Directory of Open Access Journals (Sweden)

Amy eStroud

2012-06-01

Full Text Available Single-stranded DNA binding proteins play an essential role in DNA replication and repair. They use oligosaccharide-binding folds, a five-stranded ß-sheet coiled into a closed barrel, to bind to single-stranded DNA thereby protecting and stabilizing the DNA. In eukaryotes the single-stranded DNA binding protein is known as replication protein A (RPA and consists of three distinct subunits that function as a heterotrimer. The bacterial homolog is termed single-stranded DNA-binding protein (SSB and functions as a homotetramer. In the archaeon Haloferax volcanii there are three genes encoding homologs of RPA. Two of the rpa genes (rpa1 and rpa3 exist in operons with a novel gene specific to Euryarchaeota, this gene encodes a protein that we have termed rpa-associated protein (RPAP. The rpap genes encode proteins belonging to COG3390 group and feature oligosaccharide-binding folds, suggesting that they might cooperate with RPA in binding to single-stranded DNA. Our genetic analysis showed that rpa1 and rpa3 deletion mutants have differing phenotypes; only ∆rpa3 strains are hypersensitive to DNA damaging agents. Deletion of the rpa3-associated gene rpap3 led to similar levels of DNA damage sensitivity, as did deletion of the rpa3 operon, suggesting that RPA3 and RPAP3 function in the same pathway. Protein pull-downs involving recombinant hexahistidine-tagged RPAs showed that RPA3 co-purifies with RPAP3, and RPA1 co-purifies with RPAP1. This indicates that the RPAs interact only with their respective associated proteins; this was corroborated by the inability to construct rpa1 rpap3 and rpa3 rpap1 double mutants. This is the first report investigating the individual function of the archaeal COG3390 RPA-associated proteins. We have shown genetically and biochemically that the RPAPs interact with their respective RPAs, and have uncovered a novel single-stranded DNA binding complex that is unique to Euryarchaeota.

Large-sub(pT) production of single and double photons in proton-proton and pion-proton collisions

International Nuclear Information System (INIS)

Berger, E.L.; Argonne National Lab., IL; Braaten, E.; Field, R.D.

1984-01-01

Quantum chromodynamic (QCD) predictions are made for the large transverse momentum production of single and double photons in proton-proton, proton-antiproton, and pion-proton collisions. In π - p collisions at center-of-mass energy W=27.4 GeV and psub(T)=4.0 GeV, it is estimated that about 0.3% of the 90 0 single photon triggers will be balanced on the 'away-side' by a single photon with roughly the same transverse momentum. In π + p collisions this fraction drops to about 0.09%. These fractions increase with psub(T). In addition to the pure QED annihilation term qanti q -> γγ, it is found that the QCD-induced subprocess gg -> γγ provides an important source of double photons. Photon bremsstrahlung contributions are also examined. Experimental study of the systematics of single and double photon production in hadron-hadron collisions will provide information on the size of the strong interaction coupling constant, αsub(s)(Q), and on the charges of the quarks. Knowledge of the gluon distributions within hadrons and of the effective transverse momentum of partons in hadrons can also be gained. (orig.)

Gcn4-Mediator Specificity Is Mediated by a Large and Dynamic Fuzzy Protein-Protein Complex

Directory of Open Access Journals (Sweden)

Lisa M. Tuttle

2018-03-01

Full Text Available Summary: Transcription activation domains (ADs are inherently disordered proteins that often target multiple coactivator complexes, but the specificity of these interactions is not understood. Efficient transcription activation by yeast Gcn4 requires its tandem ADs and four activator-binding domains (ABDs on its target, the Mediator subunit Med15. Multiple ABDs are a common feature of coactivator complexes. We find that the large Gcn4-Med15 complex is heterogeneous and contains nearly all possible AD-ABD interactions. Gcn4-Med15 forms via a dynamic fuzzy protein-protein interface, where ADs bind the ABDs in multiple orientations via hydrophobic regions that gain helicity. This combinatorial mechanism allows individual low-affinity and specificity interactions to generate a biologically functional, specific, and higher affinity complex despite lacking a defined protein-protein interface. This binding strategy is likely representative of many activators that target multiple coactivators, as it allows great flexibility in combinations of activators that can cooperate to regulate genes with variable coactivator requirements. : Tuttle et al. report a “fuzzy free-for-all” interaction mechanism that explains how seemingly unrelated transcription activators converge on a limited number of coactivator targets. The mechanism provides a rationale for the observation that individually weak and low-specificity interactions can combine to produce biologically critical function without requiring highly ordered structure. Keywords: transcription activation, intrinsically disordered proteins, fuzzy binding

Effects of artificial holes in very large single-grain Y_1_._5Ba_2Cu_3O_7_-_y bulk superconductors

International Nuclear Information System (INIS)

Park, S. D.; Jun, B. H.; Kim, C. J.; Park, H. W.

2017-01-01

The effects of artificial holes on the trapped magnetic fields and magnetic levitation forces of very large single-grain Y_1_._5Ba_2Cu_3O_7_-_y (Y1.5) bulk superconductors were studied. Artificial holes were made for Y1.5 powder compacts by die pressing using cylindrical dies with a diameter of 30 mm or 40 m, or rectangular dies with a side length of 50 mm. The single grain Y1.5 bulk superconductors (25 mm, 33 mm in diameter and 42 mm in side length) with artificial holes were fabricated using a top-seeded melt growth (TSMG) process for the die-pressed Y1.5 powder compacts. The magnetic levitation forces at 77 K of the 25 mm single grain Y1.5 samples with one (diameters of 4.2 mm) or six artificial holes (diameters of 2.5 mm) were 10-17% higher than that of the Y1.5 sample without artificial holes. The trapped magnetic fields at 77 K of the Y1.5 samples with artificial holes were also 9.6-18% higher than that of the Y1.5 sample without artificial holes. The 33 mm and 42 mm single grain Y1.5 samples with artificial holes (2.5 mm and 4.2 mm in diameter) also showed trapped magnetic fields 10-13% higher than that of the Y1.5 samples without artificial holes in spite of the reduced superconducting volume fraction due to the presence of artificial holes. The property enhancement in the large single grain Y1.5 bulk superconductors appears to be attributed to the formation of the pore-free regions near the artificial holes and the homogeneous oxygen distribution in the large Y123 grains

Improving the SMM and luminescence properties of lanthanide complexes with LnO9 cores in the presence of ZnII: an emissive Zn2Dy single ion magnet.

Science.gov (United States)

Fondo, Matilde; Corredoira-Vázquez, Julio; Herrera-Lanzós, Antía; García-Deibe, Ana M; Sanmartín-Matalobos, Jesús; Herrera, Juan Manuel; Colacio, Enrique; Nuñez, Cristina

2017-12-12

Mononuclear complexes of stoichiometry [Ln(H 3 L)(H 2 O)(NO 3 )](NO 3 ) 2 (Ln = Tb, 1; Dy, 2, Er, 3), which crystallise with different solvates, and the heterotrinuclear compound [Zn 2 Dy(L)(NO 3 ) 3 (OH)] (4) can be obtained with the same H 3 L compartmental ligand. The single X-ray crystal structure of the mononuclear complexes shows a LnO 9 core with a muffin-like disposition while the geometry of the DyO 9 core in 4 seems to be closer to spherical capped square antiprism. The analysis of the magnetic properties of all the complexes demonstrates that the mononuclear lanthanide compounds do not show slow relaxation of the magnetization, even when the samples are diluted with a diamagnetic matrix and subjected to a dc applied field of 1000 Oe. Nevertheless, the heterotrinuclear dysprosium complex 4·3H 2 O is a field-induced single ion magnet, with an estimated U eff barrier of 59 K. The luminescence characterisation of all the metal complexes in methanol solution at 298 K also shows a notable increase in the fluorescence emission of the heterotrinuclear complex with respect to the mononuclear ones, in such a way that 4 can be defined as a fluorescent single ion magnet.

THE GOULD's BELT VERY LARGE ARRAY SURVEY. I. THE OPHIUCHUS COMPLEX

International Nuclear Information System (INIS)

Dzib, Sergio A.; Loinard, Laurent; Rodríguez, Luis F.; Ortiz-León, Gisela N.; Pech, Gerardo; Rivera, Juana L.; Mioduszewski, Amy J.; Torres, Rosa M.; Boden, Andrew F.; Hartmann, Lee; Evans, Neal J. II; Briceño, Cesar; Tobin, John

2013-01-01

We present large-scale (∼2000 arcmin 2 ), deep (∼20 μJy), high-resolution (∼1'') radio observations of the Ophiuchus star-forming complex obtained with the Karl G. Jansky Very Large Array at λ = 4 and 6 cm. In total, 189 sources were detected, 56 of them associated with known young stellar sources, and 4 with known extragalactic objects; the other 129 remain unclassified, but most of them are most probably background quasars. The vast majority of the young stars detected at radio wavelengths have spectral types K or M, although we also detect four objects of A/F/B types and two brown dwarf candidates. At least half of these young stars are non-thermal (gyrosynchrotron) sources, with active coronas characterized by high levels of variability, negative spectral indices, and (in some cases) significant circular polarization. As expected, there is a clear tendency for the fraction of non-thermal sources to increase from the younger (Class 0/I or flat spectrum) to the more evolved (Class III or weak line T Tauri) stars. The young stars detected both in X-rays and at radio wavelengths broadly follow a Güdel-Benz relation, but with a different normalization than the most radioactive types of stars. Finally, we detect a ∼70 mJy compact extragalactic source near the center of the Ophiuchus core, which should be used as gain calibrator for any future radio observations of this region

Complex dewetting scenarios of ultrathin silicon films for large-scale nanoarchitectures.

Science.gov (United States)

Naffouti, Meher; Backofen, Rainer; Salvalaglio, Marco; Bottein, Thomas; Lodari, Mario; Voigt, Axel; David, Thomas; Benkouider, Abdelmalek; Fraj, Ibtissem; Favre, Luc; Ronda, Antoine; Berbezier, Isabelle; Grosso, David; Abbarchi, Marco; Bollani, Monica

2017-11-01

Dewetting is a ubiquitous phenomenon in nature; many different thin films of organic and inorganic substances (such as liquids, polymers, metals, and semiconductors) share this shape instability driven by surface tension and mass transport. Via templated solid-state dewetting, we frame complex nanoarchitectures of monocrystalline silicon on insulator with unprecedented precision and reproducibility over large scales. Phase-field simulations reveal the dominant role of surface diffusion as a driving force for dewetting and provide a predictive tool to further engineer this hybrid top-down/bottom-up self-assembly method. Our results demonstrate that patches of thin monocrystalline films of metals and semiconductors share the same dewetting dynamics. We also prove the potential of our method by fabricating nanotransfer molding of metal oxide xerogels on silicon and glass substrates. This method allows the novel possibility of transferring these Si-based patterns on different materials, which do not usually undergo dewetting, offering great potential also for microfluidic or sensing applications.

Synthesis, crystal growth and characterization of bioactive material: 2-amino-1H-benzo[d]imidazol-3-ium salicylate single crystal-a proton transfer molecular complex

Science.gov (United States)

Fathima, K. Saiadali; Anitha, K.

2017-05-01

The 1:1 molecular adducts 2-aminobenzimidazolium salicylate (ABIS) single crystal was synthesized and grown from 2-aminobenzimidazole (ABI) as a donor and salicylic acid (SA) as an acceptor. The cell parameter was determined using single crystal X-Ray diffraction method and the complex ABIS belongs to monoclinic system. The spectroscopic studies showed that ABIS crystal was an ion pair complex. The FTIR and Raman spectra showed that the presence of O-H, C=N, C=O vibration which confirms the proton transfer from SA to ABI. The UV-Vis spectrum exhibited a visible band at 359nm for ABIS due to the salicylate anion of the molecule. Further the antimicrobial activity of ABIS complex against Staphylococcus aureus, klebsiella pneumonia, Pseudomonas eruginos and E.coli pathogens was investigated. So the complex molecule inhibits both Gram positive and Gram negative bacterial. It is found that benzimidazole with aminogroup at position 2 increases the general antimicrobial activities of ABIS crystal.

Collectives and the design of complex systems

CERN Document Server

Wolpert, David

2004-01-01

Increasingly powerful computers are making possible distributed systems comprised of many adaptive and self-motivated computational agents. Such systems, when distinguished by system-level performance criteria, are known as "collectives." Collectives and the Design of Complex Systems lays the foundation for a science of collectives and describes how to design them for optimal performance. An introductory survey chapter is followed by descriptions of information-processing problems that can only be solved by the joint actions of large communities of computers, each running its own complex, decentralized machine-learning algorithm. Subsequent chapters analyze the dynamics and structures of collectives, as well as address economic, model-free, and control-theory approaches to designing complex systems. The work assumes a modest understanding of basic statistics and calculus. Topics and Features: Introduces the burgeoning science of collectives and its practical applications in a single useful volume Combines ap...

Self-assembly of a 3d-5f trinuclear single-molecule magnet from a pentavalent uranyl complex

International Nuclear Information System (INIS)

Chatelain, Lucile; Pecaut, Jacques; Walsh, James P.S.; Tuna, Floriana; Mazzanti, Marinella

2014-01-01

Mixed-metal uranium compounds are very attractive candidates in the design of single-molecule magnets (SMMs), but only one 3d-5f hetero-polymetallic SMM containing a uranium center is known. Herein, we report two trimeric heterodimetallic 3d-5f complexes self-assembled by cation-cation interactions between a uranyl(V) complex and a TPA-capped M II complex (M=Mn (1), Cd (2); TPA=tris(2-pyridylmethyl)amine). The metal centers were strategically chosen to promote the formation of discrete molecules rather than extended chains. Compound 1, which contains an almost linear {Mn-O=U=O-Mn} core, exhibits SMM behavior with a relaxation barrier of 81±0.5 K - the highest reported for a mono-uranium system - arising from intramolecular Mn-U exchange interactions combined with the high Ising anisotropy of the uranyl(V) moiety. Compound 1 also exhibits an open magnetic hysteresis loop at temperatures less than 3 K, with a significant coercive field of 1.9 T at 1.8 K.

Self-assembly of a 3d-5f trinuclear single-molecule magnet from a pentavalent uranyl complex

Energy Technology Data Exchange (ETDEWEB)

Chatelain, Lucile; Pecaut, Jacques [CEA-Grenoble (France). Lab. de Reconnaissance Ionique et Chimie de Coordination SCIB; Walsh, James P.S.; Tuna, Floriana [Manchester Univ. (United Kingdom). School of Chemistry and Photon Science Inst.; Mazzanti, Marinella [Ecole Polytechnique Federale de Lausanne (EPFL) (Switzerland). Inst. de Sciences et Ingenierie Chimiques

2014-12-01

Mixed-metal uranium compounds are very attractive candidates in the design of single-molecule magnets (SMMs), but only one 3d-5f hetero-polymetallic SMM containing a uranium center is known. Herein, we report two trimeric heterodimetallic 3d-5f complexes self-assembled by cation-cation interactions between a uranyl(V) complex and a TPA-capped M{sup II} complex (M=Mn (1), Cd (2); TPA=tris(2-pyridylmethyl)amine). The metal centers were strategically chosen to promote the formation of discrete molecules rather than extended chains. Compound 1, which contains an almost linear {Mn-O=U=O-Mn} core, exhibits SMM behavior with a relaxation barrier of 81±0.5 K - the highest reported for a mono-uranium system - arising from intramolecular Mn-U exchange interactions combined with the high Ising anisotropy of the uranyl(V) moiety. Compound 1 also exhibits an open magnetic hysteresis loop at temperatures less than 3 K, with a significant coercive field of 1.9 T at 1.8 K.

Uniform, dense arrays of vertically aligned, large-diameter single-walled carbon nanotubes.

Science.gov (United States)

Han, Zhao Jun; Ostrikov, Kostya

2012-04-04

Precisely controlled reactive chemical vapor synthesis of highly uniform, dense arrays of vertically aligned single-walled carbon nanotubes (SWCNTs) using tailored trilayered Fe/Al(2)O(3)/SiO(2) catalyst is demonstrated. More than 90% population of thick nanotubes (>3 nm in diameter) can be produced by tailoring the thickness and microstructure of the secondary catalyst supporting SiO(2) layer, which is commonly overlooked. The proposed model based on the atomic force microanalysis suggests that this tailoring leads to uniform and dense arrays of relatively large Fe catalyst nanoparticles on which the thick SWCNTs nucleate, while small nanotubes and amorphous carbon are effectively etched away. Our results resolve a persistent issue of selective (while avoiding multiwalled nanotubes and other carbon nanostructures) synthesis of thick vertically aligned SWCNTs whose easily switchable thickness-dependent electronic properties enable advanced applications in nanoelectronic, energy, drug delivery, and membrane technologies.

SCAP-82, Single Scattering, Albedo Scattering, Point-Kernel Analysis in Complex Geometry

International Nuclear Information System (INIS)

Disney, R.K.; Vogtman, S.E.

1987-01-01

1 - Description of problem or function: SCAP solves for radiation transport in complex geometries using the single or albedo scatter point kernel method. The program is designed to calculate the neutron or gamma ray radiation level at detector points located within or outside a complex radiation scatter source geometry or a user specified discrete scattering volume. Geometry is describable by zones bounded by intersecting quadratic surfaces within an arbitrary maximum number of boundary surfaces per zone. Anisotropic point sources are describable as pointwise energy dependent distributions of polar angles on a meridian; isotropic point sources may also be specified. The attenuation function for gamma rays is an exponential function on the primary source leg and the scatter leg with a build- up factor approximation to account for multiple scatter on the scat- ter leg. The neutron attenuation function is an exponential function using neutron removal cross sections on the primary source leg and scatter leg. Line or volumetric sources can be represented as a distribution of isotropic point sources, with un-collided line-of-sight attenuation and buildup calculated between each source point and the detector point. 2 - Method of solution: A point kernel method using an anisotropic or isotropic point source representation is used, line-of-sight material attenuation and inverse square spatial attenuation between the source point and scatter points and the scatter points and detector point is employed. A direct summation of individual point source results is obtained. 3 - Restrictions on the complexity of the problem: - The SCAP program is written in complete flexible dimensioning so that no restrictions are imposed on the number of energy groups or geometric zones. The geometric zone description is restricted to zones defined by boundary surfaces defined by the general quadratic equation or one of its degenerate forms. The only restriction in the program is that the total

Analysis of Magnetic Anisotropy and the Role of Magnetic Dilution in Triggering Single-Molecule Magnet (SMM) Behavior in a Family of CoII YIII Dinuclear Complexes with Easy-Plane Anisotropy.

Science.gov (United States)

Palacios, María A; Nehrkorn, Joscha; Suturina, Elizaveta A; Ruiz, Eliseo; Gómez-Coca, Silvia; Holldack, Karsten; Schnegg, Alexander; Krzystek, Jurek; Moreno, José M; Colacio, Enrique

2017-08-25

Three new closely related Co II Y III complexes of general formula [Co(μ-L)(μ-X)Y(NO 3 ) 2 ] (X - =NO 3 - 1, benzoate 2, or 9-anthracenecarboxylato 3) have been prepared with the compartmental ligand N,N',N''-trimethyl-N,N''-bis(2-hydroxy-3-methoxy-5-methylbenzyl)diethylenetriamine (H 2 L). In these complexes, Co II and Y III are triply bridged by two phenoxide groups belonging to the di-deprotonated ligand (L 2- ) and one ancillary anion X - . The change of the ancillary bridging group connecting Co II and Y III ions induces small differences in the trigonally distorted CoN 3 O 3 coordination sphere with a concomitant tuning of the magnetic anisotropy and intermolecular interactions. Direct current magnetic, high-frequency and -field EPR (HFEPR), frequency domain Fourier transform THz electron paramagnetic resonance (FD-FT THz-EPR) measurements, and ab initio theoretical calculations demonstrate that Co II ions in compounds 1-3 have large and positive D values (≈50 cm -1 ), which decrease with increasing the distortion of the pseudo-octahedral Co II coordination sphere. Dynamic ac magnetic susceptibility measurements indicate that compound 1 exhibits field-induced single-molecule magnet (SMM) behavior, whereas compounds 2 and 3 only display this behavior when they are magnetically diluted with diamagnetic Zn II (Zn/Co=10:1). In view of this, it is always advisable to use magnetically diluted complexes, in which intermolecular interactions and quantum tunneling of magnetism (QTM) would be at least partly suppressed, so that "hidden single-ion magnet (SIM)" behavior could emerge. Field- and temperature-dependence of the relaxation times indicate the prevalence of the Raman process in all these complexes above approximately 3 K. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Diethylenetriamine/diamines/copper (II complexes [Cu(dien(NN]Br2: Synthesis, solvatochromism, thermal, electrochemistry, single crystal, Hirshfeld surface analysis and antibacterial activity

Directory of Open Access Journals (Sweden)

Fatima Abu Saleemh

2017-09-01

Full Text Available Two dicationic water soluble mixed triamine/diamine copper (II complexes, of general formula [Cu(dienNN]Br2 (1–2 [dien = diethelenetriamine and NN is en = ethylenediamine or Me4en = N,N′,N,N′-tetramethylethylenediamine] were prepared under ultrasonic mode with a relatively high yield. These complexes were characterized by elemental microanalysis, UV visible IR spectroscopy, and thermal and electrochemical techniques. In addition, complex 2 structure was solved by X-ray single crystal and Hirshfeld surface analysis. The complex exhibits a distorted square pyramidal coordination environment around Cu(II centre. The solvatochromism of the desired complexes was investigated in water and other suitable organic solvents. The results show that the Guttmann’s DN parameter values of the solvents have mainly contributed to the shift of the d–d absorption band towards the linear increase in the wavelength of the absorption maxima of the complexes. The complex 1 showed higher antibacterial activity against the studied microorganisms compared to complex 2. Both complexes revealed promising antibacterial activities.

Microarray-based large scale detection of single feature ...

Indian Academy of Sciences (India)

2015-12-08

Dec 8, 2015 ... mental stages was used to identify single feature polymorphisms (SFPs). ... on a high-density oligonucleotide expression array in which. ∗ ..... The sign (+/−) with SFPs indicates direction of polymorphism. In the. (−) sign (i.e. ...

Direct Observation of Very Large Zero-Field Splitting in a Tetrahedral Ni(II)Se4 Coordination Complex.

Science.gov (United States)

Jiang, Shang-Da; Maganas, Dimitrios; Levesanos, Nikolaos; Ferentinos, Eleftherios; Haas, Sabrina; Thirunavukkuarasu, Komalavalli; Krzystek, J; Dressel, Martin; Bogani, Lapo; Neese, Frank; Kyritsis, Panayotis

2015-10-14

The high-spin (S = 1) tetrahedral Ni(II) complex [Ni{(i)Pr2P(Se)NP(Se)(i)Pr2}2] was investigated by magnetometry, spectroscopic, and quantum chemical methods. Angle-resolved magnetometry studies revealed the orientation of the magnetization principal axes. The very large zero-field splitting (zfs), D = 45.40(2) cm(-1), E = 1.91(2) cm(-1), of the complex was accurately determined by far-infrared magnetic spectroscopy, directly observing transitions between the spin sublevels of the triplet ground state. These are the largest zfs values ever determined--directly--for a high-spin Ni(II) complex. Ab initio calculations further probed the electronic structure of the system, elucidating the factors controlling the sign and magnitude of D. The latter is dominated by spin-orbit coupling contributions of the Ni ions, whereas the corresponding effects of the Se atoms are remarkably smaller.

Tele-operation of the electric power generation and transmission in large complex; Teleoperacao da geracao e transmissao de energia eletrica em complexo de grande porte

Energy Technology Data Exchange (ETDEWEB)

Martini, Jose Sidnei Colombo

1992-07-01

This work presents the specification and development outstanding aspects of a large supervisory and control power system. The engineering experiment, named SSCH - Hierarchical Supervision and Control System, occurred between 1982 and 1992 at Sao Paulo State and is an industrial automation power system most expressive cases carried out in this decade. More than complex development technical details, important management aspects concerning with large project execution are discussed. The SSCHs special characteristics are its dimension, complexity and realtime network analysis resources, applied to large power systems. (author)

Quantum Query Complexity for Searching Multiple Marked States from an Unsorted Database

International Nuclear Information System (INIS)

Shang Bin

2007-01-01

An important and usual sort of search problems is to find all marked states from an unsorted database with a large number of states. Grover's original quantum search algorithm is for finding single marked state with uncertainty, and it has been generalized to the case of multiple marked states, as well as been modified to find single marked state with certainty. However, the query complexity for finding all multiple marked states has not been addressed. We use a generalized Long's algorithm with high precision to solve such a problem. We calculate the approximate query complexity, which increases with the number of marked states and with the precision that we demand. In the end we introduce an algorithm for the problem on a 'duality computer' and show its advantage over other algorithms.

Isotopic shifts in chemical exchange systems. 1. Large isotope effects in the complexation of Na+ isotopes by macrocyclic polyethers

International Nuclear Information System (INIS)

Knoechel, A.; Wilken, R.D.

1981-01-01

The complexation of 24 Na + and 22 Na + by 18 of the most widely used macrocyclic polyethers (crown ethers and monocyclic and bicyclic aminopolyethers) has been investigated in view of possible equilibrium isotope shifts. Solvated salts and polyether complexes were distributed differently into two phases and isotope ratios determined in both phases. Chloroform/water systems were shown to be particularly suitable to the investigations allowing favorable distribution for Na + and 13 of the 18 polyethers employed. With crown ethers 24 Na + enrichment varied from nonsignficant values (for large crown ethers) up to 3.1 +- 0.4% (18-crown-6). In the case of bicyclic aminopolyethers, ligands with cages of optimum size to accommodate Na + showed 24 Na + enrichment between O (nonsignificant) (2.2/sub B/2./sub B/) and 5.2 +- 1.8% (2.2.1). In contrast, for 2.2.2. and its derivatives, being too large for Na + , 22 Na + enrichment varying from O (nonsignificant) (2.2.2.p) up to 5.4 +- 0.5% (2.2.2.) has been observed. These values are remarkably high. They are explained by different bonding in solvate structure and polyether complex by using the theoretical approach of Bigeleisen

An Efficient Monte Carlo Approach to Compute PageRank for Large Graphs on a Single PC

Directory of Open Access Journals (Sweden)

Sonobe Tomohiro

2016-03-01

Full Text Available This paper describes a novel Monte Carlo based random walk to compute PageRanks of nodes in a large graph on a single PC. The target graphs of this paper are ones whose size is larger than the physical memory. In such an environment, memory management is a difficult task for simulating the random walk among the nodes. We propose a novel method that partitions the graph into subgraphs in order to make them fit into the physical memory, and conducts the random walk for each subgraph. By evaluating the walks lazily, we can conduct the walks only in a subgraph and approximate the random walk by rotating the subgraphs. In computational experiments, the proposed method exhibits good performance for existing large graphs with several passes of the graph data.

Single-shot ultrabroadband two-dimensional electronic spectroscopy of the light-harvesting complex LH2.

Science.gov (United States)

Harel, Elad; Long, Phillip D; Engel, Gregory S

2011-05-01

Here we present two-dimensional (2D) electronic spectra of the light-harvesting complex LH2 from purple bacteria using coherent pulses with bandwidth of over 100 nm FWHM. This broadband excitation and detection has allowed the simultaneous capture of both the B800 and B850 bands using a single light source. We demonstrate that one laser pulse is sufficient to capture the entire 2D electronic spectrum with a high signal-to-noise ratio. At a waiting time of 800 fs, we observe population transfer from the B800 to B850 band as manifested by a prominent cross peak. These results will enable observation of the dynamics of biological systems across both ultrafast (1 ms) timescales simultaneously.

Singlet-triplet annihilation in single LHCII complexes

NARCIS (Netherlands)

Gruber, J.M.; Chmeliov, J.; Kruger, T.P.J.; Valkunas, L.; van Grondelle, R.

2015-01-01

In light harvesting complex II (LHCII) of higher plants and green algae, carotenoids (Cars) have an important function to quench chlorophyll (Chl) triplet states and therefore avoid the production of harmful singlet oxygen. The resulting Car triplet states lead to a non-linear self-quenching

"Best Practices in Using Large, Complex Samples: The Importance of Using Appropriate Weights and Design Effect Compensation"

Directory of Open Access Journals (Sweden)

Jason W. Osborne

2011-09-01

Full Text Available Large surveys often use probability sampling in order to obtain representative samples, and these data sets are valuable tools for researchers in all areas of science. Yet many researchers are not formally prepared to appropriately utilize these resources. Indeed, users of one popular dataset were generally found not to have modeled the analyses to take account of the complex sample (Johnson & Elliott, 1998 even when publishing in highly-regarded journals. It is well known that failure to appropriately model the complex sample can substantially bias the results of the analysis. Examples presented in this paper highlight the risk of error of inference and mis-estimation of parameters from failure to analyze these data sets appropriately.

BEND-INDUCED LOSSES IN A SINGLE-MODE MICROSTRUCTURED FIBER WITH A LARGE CORE

Directory of Open Access Journals (Sweden)

Y. A. Gatchin

2015-03-01

Full Text Available A study of bend-induced losses in a silica-based single-mode microstructured fiber with a core diameter ranging from 20 to 35 microns and increased relative air content in the holey cladding has been conducted. With the use of the equivalent step-index profile method in approximation of waveguide parameters of microstructured fiber (normalized frequency and normalized transverse attenuation constant the effect of bending on the spectral position of the fundamentalmode short-wavelength leakage boundary has been analyzed. Upon measurement of spectral characteristics of attenuation in the considered fibers good accordance of numerical and experimental data has been found out. It is shown that increase of the air content in the holey cladding leads to expansion of the mentioned boundary to lower wavelengths for the value from 150 to 800 nm depending on the core size and bending conditions. A single-transverse-mode propagation is achieved on fiber length of 5-10 meters due to a substantial difference in losses of fundamental and higher-order guided modes attained by bending. Optical losses in all studied samples are less than 10 dB/km at the wavelength λ = 1550 nm. The results of the study can be applied in the design of high-power laser systems having such basic requirements as a relatively large mode spot and high beam quality.

Very Large Inflammatory Odontogenic Cyst with Origin on a Single Long Time Traumatized Lower Incisor

Science.gov (United States)

Freitas, Filipe; Andre, Saudade; Moreira, Andre; Carames, Joao

2015-01-01

One of the consequences of traumatic injuries is the chance of aseptic pulp necrosis to occur which in time may became infected and give origin to periapical pathosis. Although the apical granulomas and cysts are a common condition, there appearance as an extremely large radiolucent image is a rare finding. Differential diagnosis with other radiographic-like pathologies, such as keratocystic odontogenic tumour or unicystic ameloblastoma, is mandatory. The purpose of this paper is to report a very large radicular cyst caused by a single mandibular incisor traumatized long back, in a 60-year-old male. Medical and clinical histories were obtained, radiographic and cone beam CT examinations performed and an initial incisional biopsy was done. The final decision was to perform a surgical enucleation of a lesion, 51.4 mm in length. The enucleated tissue biopsy analysis was able to render the diagnosis as an inflammatory odontogenic cyst. A 2 year follow-up showed complete bone recovery. PMID:26393219

Synthesis and temperature dependent Raman studies of large crystalline faces topological GeBi4Te7 single crystal

Science.gov (United States)

Mal, Priyanath; Bera, G.; Turpu, G. R.; Srivastava, Sunil K.; Das, Pradip

2018-05-01

We present a study of structural and vibrational properties of topological insulator GeBi4Te7. Modified Bridgeman technique is employed to synthesize the single crystal with relatively large crystalline faces. Sharp (0 0 l) reflection confirms the high crystallinity of the single crystal. We have performed temperature dependent Raman measurement for both parallel and perpendicular to crystallographic c axis geometry. In parallel configuration we have observed seven Raman modes whereas in perpendicular geometry only four of these are identified. Appearance and disappearance of Raman modes having different intensities for parallel and perpendicular to c measurement attribute to the mode polarization. Progressive blue shift is observed with lowering temperature, reflects the increase in internal stress.

Single failure effects of reactor coolant system large bore hydraulic snubbers for Korean Standard Nuclear Power Plant

International Nuclear Information System (INIS)

Choi, T.S.; Park, S.H.; Sung, K.K.; Kim, T.W.; Jheon, J.H.

1996-01-01

A potential snubber single failure is one of the safety significances identified in General Safety Issue 113 for Large Bore Hydraulic Snubber (LBHS) dynamic qualification. This paper investigates dynamic structural effects of single failures of the steam generator and reactor coolant pump snubbers in Korean Standard Nuclear Power Plant by performing the time history dynamic analyses for the reactor coolant system under seismic and postulated pipe break events. The seismic input motions considered are the synthesized ground time histories conforming to SRP 3.7.1, and he postulated pipe break input loadings result from steam generator main seam line and feedwater line pipe breaks which govern pipe breaks remaining after applying LBB to the main coolant line and primary side ranch lines equal to and greater than 12 inch nominal pipe size

A high-throughput 2D-analytical technique to obtain single protein parameters from complex cell lysates for in silico process development of ion exchange chromatography.

Science.gov (United States)

Kröner, Frieder; Elsäßer, Dennis; Hubbuch, Jürgen

2013-11-29

The accelerating growth of the market for biopharmaceutical proteins, the market entry of biosimilars and the growing interest in new, more complex molecules constantly pose new challenges for bioseparation process development. In the presented work we demonstrate the application of a multidimensional, analytical separation approach to obtain the relevant physicochemical parameters of single proteins in a complex mixture for in silico chromatographic process development. A complete cell lysate containing a low titre target protein was first fractionated by multiple linear salt gradient anion exchange chromatography (AEC) with varying gradient length. The collected fractions were subsequently analysed by high-throughput capillary gel electrophoresis (HT-CGE) after being desalted and concentrated. From the obtained data of the 2D-separation the retention-volumes and the concentration of the single proteins were determined. The retention-volumes of the single proteins were used to calculate the related steric-mass action model parameters. In a final evaluation experiment the received parameters were successfully applied to predict the retention behaviour of the single proteins in salt gradient AEC. Copyright © 2013 Elsevier B.V. All rights reserved.

Scanning, Multibeam, Single Photon Lidars for Rapid, Large Scale, High Resolution, Topographic and Bathymetric Mapping

Directory of Open Access Journals (Sweden)

John J. Degnan

2016-11-01

Full Text Available Several scanning, single photon sensitive, 3D imaging lidars are herein described that operate at aircraft above ground levels (AGLs between 1 and 11 km, and speeds in excess of 200 knots. With 100 beamlets and laser fire rates up to 60 kHz, we, at the Sigma Space Corporation (Lanham, MD, USA, have interrogated up to 6 million ground pixels per second, all of which can record multiple returns from volumetric scatterers such as tree canopies. High range resolution has been achieved through the use of subnanosecond laser pulsewidths, detectors and timing receivers. The systems are presently being deployed on a variety of aircraft to demonstrate their utility in multiple applications including large scale surveying, bathymetry, forestry, etc. Efficient noise filters, suitable for near realtime imaging, have been shown to effectively eliminate the solar background during daytime operations. Geolocation elevation errors measured to date are at the subdecimeter level. Key differences between our Single Photon Lidars, and competing Geiger Mode lidars are also discussed.

Combining eastern and western practices for safe and effective endoscopic resection of large complex colorectal lesions.

Science.gov (United States)

Emmanuel, Andrew; Gulati, Shraddha; Burt, Margaret; Hayee, Bu'Hussain; Haji, Amyn

2018-05-01

Endoscopic resection of large colorectal polyps is well established. However, significant differences in technique exist between eastern and western interventional endoscopists. We report the results of endoscopic resection of large complex colorectal lesions from a specialist unit that combines eastern and western techniques for assessment and resection. Endoscopic resections of colorectal lesions of at least 2 cm were included. Lesions were assessed using magnification chromoendoscopy supplemented by colonoscopic ultrasound in selected cases. A lesion-specific approach to resection with endoscopic mucosal resection or endoscopic submucosal dissection (ESD) was used. Surveillance endoscopy was performed at 3 (SC1) and 12 (SC2) months. Four hundred and sixty-six large (≥20 mm) colorectal lesions (mean size 54.8 mm) were resected. Three hundread and fifty-six were resected using endoscopic mucosal resection and 110 by ESD or hybrid ESD. Fifty-one percent of lesions had been subjected to previous failed attempts at resection or heavy manipulation (≥6 biopsies). Nevertheless, endoscopic resection was deemed successful after an initial attempt in 98%. Recurrence occurred in 15% and could be treated with endoscopic resection in most. Only two patients required surgery for perforation. Nine patients had postprocedure bleeding; only two required endoscopic clips. Ninety-six percent of patients without invasive cancer were free from recurrence and had avoided surgery at last follow-up. Combining eastern and western practices for assessment and resection results in safe and effective organ-conserving treatment of complex colorectal lesions. Accurate assessment before and after resection using magnification chromoendoscopy and a lesion-specific approach to resection, incorporating ESD where appropriate, are important factors in achieving these results.

Macroscopic, pathologic and immunologic investigations of ten patients with carcinoma of oral cavity treated by a single large dose irradiation

International Nuclear Information System (INIS)

Mikuriya, Shuichi; Saito, Tsutomu; Konoeda, Koichi; Igarashi, Seishi; Hirohashi, Hitoshi

1979-01-01

The immunosuppressive effect of radiation has been emphasized. Although the irradiated cancer cells die gradually during the treatment, it is understood that they keep cancer specific antigenecity in that process. Another words, we assume that the immunologic capacity participates in the dying process of cancer cells by radiotherapy. We have been preferring to treat carcinoma by a single large dose irradiation method because this method does not impair the patient's immunologic capacity. On this time, we treated ten patients with carcinoma of oral cavity by this method and could obtain favorable results. 1) Ten patients with carcinoma of oral cavity classified in T1N0M0-T3N0M0 were irradiated by 4 - 10 MeV betatron electron. In seven patients, 2,500 - 3,000 rads were given at once and other three patients were irradiated with fractionated dose of 1,000 rads three times within two weeks (total 3,000 rads per two weeks). 2) Effects of a single large dose irradiation were remarkable and almost all cancer cells in these patients disappeared both macroscopically and pathologically. 3) According to the results of cellular immunity tests, numbers of peripheral lymphocytes, absolute numbers of fractionated T and B cells, and blastoid formation rate of lymphocytes stimulated by PHA in vitro were all increased and values obtained by four kinds of skin tests were also elevated after the radiations. These results indicate that the single large dose irradiation for these patients does not impair the immunologic capacity of the patients. (author)

Chequered surfaces and complex matrices

International Nuclear Information System (INIS)

Morris, T.R.; Southampton Univ.

1991-01-01

We investigate a large-N matrix model involving general complex matrices. It can be reinterpreted as a model of two hermitian matrices with specific couplings, and as a model of positive definite hermitian matrices. Large-N perturbation theory generates dynamical triangulations in which the triangles can be chequered (i.e. coloured so that neighbours are opposite colours). On a sphere there is a simple relation between such triangulations and those generated by the single hermitian matrix model. For the torus (and a quartic potential) we solve the counting problem for the number of triangulations that cannot be quechered. The critical physics of chequered triangulations is the same as that of the hermitian matrix model. We show this explicitly by solving non-perturbatively pure two-dimensional ''chequered'' gravity. The interpretative framework given here applies to a number of other generalisations of the hermitian matrix model. (orig.)

The composing technique of fast and large scale nuclear data acquisition and control system with single chip microcomputers and PC computers

International Nuclear Information System (INIS)

Xu Zurun; Wu Shiying; Liu Haitao; Yao Yangsen; Wang Yingguan; Yang Chaowen

1998-01-01

The technique of employing single-chip microcomputers and PC computers to compose a fast and large scale nuclear data acquisition and control system was discussed in detail. The optimum composition mode of this kind of system, the acquisition and control circuit unit based on single-chip microcomputers, the real-time communication methods and the software composition under the Windows 3.2 were also described. One, two and three dimensional spectra measured by this system were demonstrated

The composing technique of fast and large scale nuclear data acquisition and control system with single chip microcomputers and PC computers

International Nuclear Information System (INIS)

Xu Zurun; Wu Shiying; Liu Haitao; Yao Yangsen; Wang Yingguan; Yang Chaowen

1997-01-01

The technique of employing single-chip microcomputers and PC computers to compose a fast and large scale nuclear data acquisition and control system was discussed in detail. The optimum composition mode of this kind of system, the acquisition and control circuit unit based on single-chip microcomputers, the real-time communication methods and the software composition under the Windows 3.2 were also described. One, two and three dimensional spectra measured by this system were demonstrated

On the use of single large-area photodiodes in scintillation counters

International Nuclear Information System (INIS)

Morrell, C.

1989-12-01

The compilation of this review was originally intended to assess the possibility of using photodiode-based scintillation counters in fluorescence EXAFS (or FLEXAFS) systems as a low-cost alternative to photomultiplier-based counters. The X-ray energies encountered in FLEXAFS experiments range from a few keV to a few tens of keV, and detectors are required to have some energy resolution and/or high count-rate capability in order to optimize the quality of data collected. The results presented in the reviewed literature imply strongly that photodiodes do not compete successfully with photomultipliers in scintillation counting systems for X-ray energies below the order of 100keV, at least at the present stage of photodiode technology. Nevertheless it is likely that there are other applications requiring X-ray detectors for which a photodiode-based scintillation counter may be perfectly adequate, and it is therefore felt that such a review is still useful. In addition, large-area single photodiodes have much to offer as X-ray detectors in their own right, and several of the considerations regarding their use in scintillation counters are highly relevant to this application. (author)

Estimating large complex projects Estimando proyectos grandes y complejos

Directory of Open Access Journals (Sweden)

Cliff Schexnayder

2007-08-01

Full Text Available Managing large capital construction projects requires the coordination of a multitude of human, organizational, technical, and natural resources. Quite often, the engineering and construction complexities of such projects are overshadowed by economic, societal, and political challenges. The ramifications and effects, which result from differences between early project cost estimates and the bid price or the final project cost, are significant. Over the time span between the initiation of a project and the completion of construction many factors influence a project's final costs. This time span is normally several years in duration but for highly complex and technologically challenging projects, project duration can easily exceed a decade. Over that period, changes to the project scope often occur. The subject here is a presentation of strategies that support realistic cost estimating. Through literature review and interviews with transportation agencies in the U.S. and internationally the authors developed a database of the factors that are the root causes of cost estimation problemsGestionar proyectos de construcción de grandes capitales requiere de la coordinación de una multitud de recursos humanos, organizacionales, técnicos y naturales. Frecuentemente, las complejidades del diseño y construcción de esos grandes proyectos son tapadas por sus desafíos económicos, políticos y sociales. Las ramificaciones y efectos que resultan de las diferencias entre la estimación de costo inicial, el costo de la propuesta adjudicada y el costo final del proyecto son significativas. Hay numerosos factores que inciden en el costo final del proyecto entre su inicio y finalización. La duración es generalmente de varios años y puede incluso superar la década para aquellos especialmente complejos y desafiantes. En ese período de tiempo, cambios en los alcances del proyecto cambian frecuentemente. El tópico del presente artículo es mostrar

Single-Molecule Interfacial Electron Transfer

Energy Technology Data Exchange (ETDEWEB)

Lu, H. Peter [Bowling Green State Univ., Bowling Green, OH (United States). Dept. of Chemistry and Center for Photochemical Sciences

2017-11-28

This project is focused on the use of single-molecule high spatial and temporal resolved techniques to study molecular dynamics in condensed phase and at interfaces, especially, the complex reaction dynamics associated with electron and energy transfer rate processes. The complexity and inhomogeneity of the interfacial ET dynamics often present a major challenge for a molecular level comprehension of the intrinsically complex systems, which calls for both higher spatial and temporal resolutions at ultimate single-molecule and single-particle sensitivities. Combined single-molecule spectroscopy and electrochemical atomic force microscopy approaches are unique for heterogeneous and complex interfacial electron transfer systems because the static and dynamic inhomogeneities can be identified and characterized by studying one molecule at a specific nanoscale surface site at a time. The goal of our project is to integrate and apply these spectroscopic imaging and topographic scanning techniques to measure the energy flow and electron flow between molecules and substrate surfaces as a function of surface site geometry and molecular structure. We have been primarily focusing on studying interfacial electron transfer under ambient condition and electrolyte solution involving both single crystal and colloidal TiO₂ and related substrates. The resulting molecular level understanding of the fundamental interfacial electron transfer processes will be important for developing efficient light harvesting systems and broadly applicable to problems in fundamental chemistry and physics. We have made significant advancement on deciphering the underlying mechanism of the complex and inhomogeneous interfacial electron transfer dynamics in dyesensitized TiO₂ nanoparticle systems that strongly involves with and regulated by molecule-surface interactions. We have studied interfacial electron transfer on TiO₂ nanoparticle surfaces by using ultrafast single

ComplexRec 2017

DEFF Research Database (Denmark)

a single step in the user's more complex background need. These background needs can often place a variety of constraints on which recommendations are interesting to the user and when they are appropriate. However, relatively little research has been done on these complex recommendation scenarios....... The ComplexRec 2017 workshop addressed this by providing an interactive venue for discussing approaches to recommendation in complex scenarios that have no simple one-size-fits-all-solution....

Identification of Zn-vacancy-hydrogen complexes in ZnO single crystals: A challenge to positron annihilation spectroscopy

Science.gov (United States)

Brauer, G.; Anwand, W.; Grambole, D.; Grenzer, J.; Skorupa, W.; Čížek, J.; Kuriplach, J.; Procházka, I.; Ling, C. C.; So, C. K.; Schulz, D.; Klimm, D.

2009-03-01

A systematic study of various, nominally undoped ZnO single crystals, either hydrothermally grown (HTG) or melt grown (MG), has been performed. The crystal quality has been assessed by x-ray diffraction, and a comprehensive estimation of the detailed impurity and hydrogen contents by inductively coupled plasma mass spectrometry and nuclear reaction analysis, respectively, has been made also. High precision positron lifetime experiments show that a single positron lifetime is observed in all crystals investigated, which clusters at 180-182 ps and 165-167 ps for HTG and MG crystals, respectively. Furthermore, hydrogen is detected in all crystals in a bound state with a high concentration (at least 0.3at.% ), whereas the concentrations of other impurities are very small. From ab initio calculations it is suggested that the existence of Zn-vacancy-hydrogen complexes is the most natural explanation for the given experimental facts at present. Furthermore, the distribution of H at a metal/ZnO interface of a MG crystal, and the H content of a HTG crystal upon annealing and time afterward has been monitored, as this is most probably related to the properties of electrical contacts made at ZnO and the instability in p -type conductivity observed at ZnO nanorods in literature. All experimental findings and presented theoretical considerations support the conclusion that various types of Zn-vacancy-hydrogen complexes exist in ZnO and need to be taken into account in future studies, especially for HTG materials.

Infinite Multiple Membership Relational Modeling for Complex Networks

DEFF Research Database (Denmark)

Mørup, Morten; Schmidt, Mikkel Nørgaard; Hansen, Lars Kai

Learning latent structure in complex networks has become an important problem fueled by many types of networked data originating from practically all fields of science. In this paper, we propose a new non-parametric Bayesian multiplemembership latent feature model for networks. Contrary to existing...... multiplemembership models that scale quadratically in the number of vertices the proposedmodel scales linearly in the number of links admittingmultiple-membership analysis in large scale networks. We demonstrate a connection between the single membership relational model and multiple membership models and show...

Capturing complex human behaviors in representative sports contexts with a single camera.

Science.gov (United States)

Duarte, Ricardo; Araújo, Duarte; Fernandes, Orlando; Fonseca, Cristina; Correia, Vanda; Gazimba, Vítor; Travassos, Bruno; Esteves, Pedro; Vilar, Luís; Lopes, José

2010-01-01

In the last years, several motion analysis methods have been developed without considering representative contexts for sports performance. The purpose of this paper was to explain and underscore a straightforward method to measure human behavior in these contexts. Procedures combining manual video tracking (with TACTO device) and bidimensional reconstruction (through direct linear transformation) using a single camera were used in order to capture kinematic data required to compute collective variable(s) and control parameter(s). These procedures were applied to a 1vs1 association football task as an illustrative subphase of team sports and will be presented in a tutorial fashion. Preliminary analysis of distance and velocity data identified a collective variable (difference between the distance of the attacker and the defender to a target defensive area) and two nested control parameters (interpersonal distance and relative velocity). Findings demonstrated that the complementary use of TACTO software and direct linear transformation permit to capture and reconstruct complex human actions in their context in a low dimensional space (information reduction).

The challenge for genetic epidemiologists: how to analyze large numbers of SNPs in relation to complex diseases.

Science.gov (United States)

Heidema, A Geert; Boer, Jolanda M A; Nagelkerke, Nico; Mariman, Edwin C M; van der A, Daphne L; Feskens, Edith J M

2006-04-21

Genetic epidemiologists have taken the challenge to identify genetic polymorphisms involved in the development of diseases. Many have collected data on large numbers of genetic markers but are not familiar with available methods to assess their association with complex diseases. Statistical methods have been developed for analyzing the relation between large numbers of genetic and environmental predictors to disease or disease-related variables in genetic association studies. In this commentary we discuss logistic regression analysis, neural networks, including the parameter decreasing method (PDM) and genetic programming optimized neural networks (GPNN) and several non-parametric methods, which include the set association approach, combinatorial partitioning method (CPM), restricted partitioning method (RPM), multifactor dimensionality reduction (MDR) method and the random forests approach. The relative strengths and weaknesses of these methods are highlighted. Logistic regression and neural networks can handle only a limited number of predictor variables, depending on the number of observations in the dataset. Therefore, they are less useful than the non-parametric methods to approach association studies with large numbers of predictor variables. GPNN on the other hand may be a useful approach to select and model important predictors, but its performance to select the important effects in the presence of large numbers of predictors needs to be examined. Both the set association approach and random forests approach are able to handle a large number of predictors and are useful in reducing these predictors to a subset of predictors with an important contribution to disease. The combinatorial methods give more insight in combination patterns for sets of genetic and/or environmental predictor variables that may be related to the outcome variable. As the non-parametric methods have different strengths and weaknesses we conclude that to approach genetic association

Crash problem definition and safety benefits methodology for stability control for single-unit medium and heavy trucks and large-platform buses

Science.gov (United States)

2009-10-01

This report presents the findings of a comprehensive engineering analysis of electronic stability control (ESC) and roll stability control (RSC) systems for single-unit medium and heavy trucks and large-platform buses. This report details the applica...

A constraint logic programming approach to associate 1D and 3D structural components for large protein complexes.

Science.gov (United States)

Dal Palù, Alessandro; Pontelli, Enrico; He, Jing; Lu, Yonggang

2007-01-01

The paper describes a novel framework, constructed using Constraint Logic Programming (CLP) and parallelism, to determine the association between parts of the primary sequence of a protein and alpha-helices extracted from 3D low-resolution descriptions of large protein complexes. The association is determined by extracting constraints from the 3D information, regarding length, relative position and connectivity of helices, and solving these constraints with the guidance of a secondary structure prediction algorithm. Parallelism is employed to enhance performance on large proteins. The framework provides a fast, inexpensive alternative to determine the exact tertiary structure of unknown proteins.

Local progression and pseudo progression after single fraction or fractionated stereotactic radiotherapy for large brain metastases. A single centre study

Energy Technology Data Exchange (ETDEWEB)

Wiggenraad, R.; Verbeek-de Kanter, A.; Mast, M. [Radiotherapy Centre West, The Hague (Netherlands); Molenaar, R. [Diaconessenhuis, Leiden (Netherlands). Dept. of Neurology; Lycklama a Nijeholt, G. [Medical Centre Haagladen, The Hague (Netherlands). Dept. of Radiology; Vecht, C. [Medical Centre Haagladen, The Hague (Netherlands). Dept. of Neurology; Struikmans, H. [Radiotherapy Centre West, The Hague (Netherlands); Leiden Univ. Medical Centre (Netherlands). Dept. of Radiotherapy; Kal, H.B.

2012-08-15

Purpose: The 1-year local control rates after single-fraction stereotactic radiotherapy (SRT) for brain metastases > 3 cm diameter are less than 70%, but with fractionated SRT (FSRT) higher local control rates have been reported. The purpose of this study was to compare our treatment results with SRT and FSRT for large brain metastases. Materials and methods: In two consecutive periods, 41 patients with 46 brain metastases received SRT with 1 fraction of 15 Gy, while 51 patients with 65 brain metastases received FSRT with 3 fractions of 8 Gy. We included patients with brain metastases with a planning target volume of > 13 cm{sup 3} or metastases in the brainstem. Results: The minimum follow-up of patients still alive was 22 months. Comparing 1 fraction of 15 Gy with 3 fractions of 8 Gy, the 1-year rates of freedom from any local progression (54% and 61%, p = 0.93) and pseudo progression (85% and 75%, p = 0.25) were not significantly different. Overall survival rates were also not different. Conclusion: The 1-year local progression and pseudo progression rates after 1 fraction of 15 Gy or 3 fractions of 8 Gy for large brain metastases and metastases in the brainstem are similar. For better local control rates, FSRT schemes with a higher biological equivalent dose may be necessary. (orig.)

Local progression and pseudo progression after single fraction or fractionated stereotactic radiotherapy for large brain metastases. A single centre study

International Nuclear Information System (INIS)

Wiggenraad, R.; Verbeek-de Kanter, A.; Mast, M.; Molenaar, R.; Lycklama a Nijeholt, G.; Vecht, C.; Struikmans, H.; Leiden Univ. Medical Centre; Kal, H.B.

2012-01-01

Purpose: The 1-year local control rates after single-fraction stereotactic radiotherapy (SRT) for brain metastases > 3 cm diameter are less than 70%, but with fractionated SRT (FSRT) higher local control rates have been reported. The purpose of this study was to compare our treatment results with SRT and FSRT for large brain metastases. Materials and methods: In two consecutive periods, 41 patients with 46 brain metastases received SRT with 1 fraction of 15 Gy, while 51 patients with 65 brain metastases received FSRT with 3 fractions of 8 Gy. We included patients with brain metastases with a planning target volume of > 13 cm 3 or metastases in the brainstem. Results: The minimum follow-up of patients still alive was 22 months. Comparing 1 fraction of 15 Gy with 3 fractions of 8 Gy, the 1-year rates of freedom from any local progression (54% and 61%, p = 0.93) and pseudo progression (85% and 75%, p = 0.25) were not significantly different. Overall survival rates were also not different. Conclusion: The 1-year local progression and pseudo progression rates after 1 fraction of 15 Gy or 3 fractions of 8 Gy for large brain metastases and metastases in the brainstem are similar. For better local control rates, FSRT schemes with a higher biological equivalent dose may be necessary. (orig.)

Failure of large transformation projects from the viewpoint of complex adaptive systems: Management principles for dealing with project dynamics

NARCIS (Netherlands)

Janssen, M.; Voort, H. van der; Veenstra, A.F.E. van

2015-01-01

Many large transformation projects do not result in the outcomes desired or envisioned by the stakeholders. This type of project is characterised by dynamics which are both caused by and result of uncertainties and unexpected behaviour. In this paper a complex adaptive system (CAS) view was adopted

Monte Carlo simulations of flexible polyanions complexing with whey proteins at their isoelectric point.

Science.gov (United States)

de Vries, R

2004-02-15

Electrostatic complexation of flexible polyanions with the whey proteins alpha-lactalbumin and beta-lactoglobulin is studied using Monte Carlo simulations. The proteins are considered at their respective isoelectric points. Discrete charges on the model polyelectrolytes and proteins interact through Debye-Huckel potentials. Protein excluded volume is taken into account through a coarse-grained model of the protein shape. Consistent with experimental results, it is found that alpha-lactalbumin complexes much more strongly than beta-lactoglobulin. For alpha-lactalbumin, strong complexation is due to localized binding to a single large positive "charge patch," whereas for beta-lactoglobulin, weak complexation is due to diffuse binding to multiple smaller charge patches. Copyright 2004 American Institute of Physics

Effect of the single-scattering phase function on light transmission through disordered media with large inhomogeneities

International Nuclear Information System (INIS)

Marinyuk, V V; Sheberstov, S V

2017-01-01

We calculate the total transmission coefficient (transmittance) of a disordered medium with large (compared to the light wavelength) inhomogeneities. To model highly forward scattering in the medium we take advantage of the Gegenbauer kernel phase function. In a subdiffusion thickness range, the transmittance is shown to be sensitive to the specific form of the single-scattering phase function. The effect reveals itself at grazing angles of incidence and originates from small-angle multiple scattering of light. Our results are in a good agreement with numerical solutions to the radiative transfer equation. (paper)

Cascade-based attacks on complex networks

Science.gov (United States)

Motter, Adilson E.; Lai, Ying-Cheng

2002-12-01

We live in a modern world supported by large, complex networks. Examples range from financial markets to communication and transportation systems. In many realistic situations the flow of physical quantities in the network, as characterized by the loads on nodes, is important. We show that for such networks where loads can redistribute among the nodes, intentional attacks can lead to a cascade of overload failures, which can in turn cause the entire or a substantial part of the network to collapse. This is relevant for real-world networks that possess a highly heterogeneous distribution of loads, such as the Internet and power grids. We demonstrate that the heterogeneity of these networks makes them particularly vulnerable to attacks in that a large-scale cascade may be triggered by disabling a single key node. This brings obvious concerns on the security of such systems.

Large-sized SmBCO single crystals with T sub c over 93 K grown in atmospheric ambient by crystal pulling

CERN Document Server

Yao Xin; Shiohara, Y

2003-01-01

Sm sub 1 sub + sub x Ba sub 2 sub - sub x Cu sub 3 O sub z (SmBCO) single crystals were grown under atmospheric ambient by the top-seeded solution growth method. Inductively coupled plasma results indicate that there is negligible Sm substitution for Ba sites in the grown SmBCO crystals, although they crystallized from different Ba-Cu-O solvents with a wide composition range (Ba/Cu ratio of 0.5-0.6). As a result, these crystals show high superconducting critical transition temperature values (T sub c) of over 93 K with a sharp transition width after oxygenation. A large-sized crystal with an a-b plane of 23 x 22 mm sup 2 and a c-axis of 19 mm was obtained at a high growth rate of nearly 0.13 mm h sup - sup 1. In short, with more controllable thermodynamic parameters, SmBCO single crystals can readily achieve both large size and high superconducting properties. (rapid communication)

Benchmarking of London Dispersion-Accounting Density Functional Theory Methods on Very Large Molecular Complexes.

Science.gov (United States)

Risthaus, Tobias; Grimme, Stefan

2013-03-12

A new test set (S12L) containing 12 supramolecular noncovalently bound complexes is presented and used to evaluate seven different methods to account for dispersion in DFT (DFT-D3, DFT-D2, DFT-NL, XDM, dDsC, TS-vdW, M06-L) at different basis set levels against experimental, back-corrected reference energies. This allows conclusions about the performance of each method in an explorative research setting on "real-life" problems. Most DFT methods show satisfactory performance but, due to the largeness of the complexes, almost always require an explicit correction for the nonadditive Axilrod-Teller-Muto three-body dispersion interaction to get accurate results. The necessity of using a method capable of accounting for dispersion is clearly demonstrated in that the two-body dispersion contributions are on the order of 20-150% of the total interaction energy. MP2 and some variants thereof are shown to be insufficient for this while a few tested D3-corrected semiempirical MO methods perform reasonably well. Overall, we suggest the use of this benchmark set as a "sanity check" against overfitting to too small molecular cases.

Three Cyanide-Bridged One-Dimensional Single Chain Co"I"I"I-Mn"I"I Complexes: Rational Design, Synthesis, Crystal Structures and Magnetic Properties

International Nuclear Information System (INIS)

Zhang, Daopeng; Zhao, Zengdian; Wang, Ping; Chen, Xia

2012-01-01

Two pyridinecarboxamide dicyanidecobalt(III) building blocks and two mononuclear seven-coordinated macrocycle manganese(II) compounds have been rationally selected to assemble cyanide-bridged heterobimetallic complexes, resulting in three cyanide-bridged Co"I"I"I-Mn"I"I complexes. Single X-ray diffraction analysis show that these complexes {[Mn(L"1)][Co(bpb)]}ClO_4·CH_3OH·0.5H_2O (1), {[Mn(L"2)][Co(bpb)]}ClO_4·0.5CH_3OH (2) and {[Mn(L"1)][Cobpmb]}ClO_4·H_2O (3) (L"1 = 3,6-diazaoctane-1,8-diamine, L"2 = 3,6-dioxaoctano-1,8- diamine: bpb"2"- = 1,2-bis(pyridine-2-carboxamido)benzenate, bpmb"2"- = 1,2-bis(pyridine-2-carboxamido)-4- methyl-benzenate) all present predictable one-dimensional single chain structures. The molecular structures of these one-dimensional complexes consists of alternating units of [Mn(L)]"2"+ (L = L"1 or L"2) and [Co(L')(CN)_2]"- (L' = bpb"2"-, or bpmb"2"-), forming a cyanide-bridged cationic polymeric chain with free ClO_4"- as the balance anion. The coordination geometry of manganese(II) ion in the three one-dimensional complexes is a slightly distorted pentagonal-bipyrimidal with two cyanide nitrogen atoms at the trans positions and N_5 or N_3O_2 coordinating mode at the equatorial plane from ligand L"1 or L"2. Investigation over magnetic properties of these complexes reveals that the very weak magnetic coupling between neighboring Mn(II) ions connected by the diamagnetic dicyanidecobalt(III) building block. A best-fit to the magnetic susceptibility of complex 1 leads to the magnetic coupling constants J = .0.084(3) cm"-"1

A single point acupuncture treatment at large intestine meridian: a randomized controlled trial in acute tonsillitis and pharyngitis.

Science.gov (United States)

Fleckenstein, Johannes; Lill, Christian; Lüdtke, Rainer; Gleditsch, Jochen; Rasp, Gerd; Irnich, Dominik

2009-09-01

One out of 4 patients visiting a general practitioner reports of a sore throat associated with pain on swallowing. This study was established to examine the immediate pain alleviating effect of a single point acupuncture treatment applied to the large intestine meridian of patients with sore throat. Sixty patients with acute tonsillitis and pharyngitis were enrolled in this randomized placebo-controlled trial. They either received acupuncture, or sham laser acupuncture, directed to the large intestine meridian section between acupuncture points LI 8 and LI 10. The main outcome measure was the change of pain intensity on swallowing a sip of water evaluated by a visual analog scale 15 minutes after treatment. A credibility assessment regarding the respective treatment was performed. The pain intensity for the acupuncture group before and immediately after therapy was 5.6+/-2.8 and 3.0+/-3.0, and for the sham group 5.6+/-2.5 and 3.8+/-2.5, respectively. Despite the articulation of a more pronounced improvement among the acupuncture group, there was no significant difference between groups (Delta=0.9, confidence interval: -0.2-2.0; P=0.12; analysis of covariance). Patients' satisfaction was high in both treatment groups. The study was prematurely terminated due to a subsequent lack of suitable patients. A single acupuncture treatment applied to a selected area of the large intestine meridian was no more effective in the alleviation of pain associated with clinical sore throat than sham laser acupuncture applied to the same area. Hence, clinically relevant improvement could be achieved. Pain alleviation might partly be due to the intense palpation of the large intestine meridian. The benefit of a comprehensive acupuncture treatment protocol in this condition should be subject to further trials.

A novel non-enzymatic hydrogen peroxide sensor based on single walled carbon nanotubes-manganese complex modified glassy carbon electrode

International Nuclear Information System (INIS)

Salimi, Abdollah; Mahdioun, Monierosadat; Noorbakhsh, Abdollah; Abdolmaleki, Amir; Ghavami, Raoof

2011-01-01

A simple procedure was developed to prepare a glassy carbon (GC) electrode modified with single wall carbon nanotubes (SWCNTs) and phenazine derivative of Mn-complex. With immersing the GC/CNTs modified electrode into Mn-complex solution for a short period of time 20-100 s, a stable thin layer of the complex was immobilized onto electrode surface. Modified electrode showed a well defined redox couples at wide pH range (1-12). The surface coverages and heterogeneous electron transfer rate constants (k s ) of immobilized Mn-complex were approximately 1.58 x 10 -10 mole cm -2 and 48.84 s -1 . The modified electrode showed excellent electrocatalytic activity toward H 2 O 2 reduction. Detection limit, sensitivity, linear concentration range and k cat for H 2 O 2 were, 0.2 μM and 692 nA μM -1 cm -2 , 1 μM to 1.5 mM and 7.96(±0.2) x 10 3 M -1 s -1 , respectively. Compared to other modified electrodes, this electrode has many advantageous such as remarkable catalytic activity, good reproducibility, simple preparation procedure and long term stability.

A new large-scale manufacturing platform for complex biopharmaceuticals.

Science.gov (United States)

Vogel, Jens H; Nguyen, Huong; Giovannini, Roberto; Ignowski, Jolene; Garger, Steve; Salgotra, Anil; Tom, Jennifer

2012-12-01

Complex biopharmaceuticals, such as recombinant blood coagulation factors, are addressing critical medical needs and represent a growing multibillion-dollar market. For commercial manufacturing of such, sometimes inherently unstable, molecules it is important to minimize product residence time in non-ideal milieu in order to obtain acceptable yields and consistently high product quality. Continuous perfusion cell culture allows minimization of residence time in the bioreactor, but also brings unique challenges in product recovery, which requires innovative solutions. In order to maximize yield, process efficiency, facility and equipment utilization, we have developed, scaled-up and successfully implemented a new integrated manufacturing platform in commercial scale. This platform consists of a (semi-)continuous cell separation process based on a disposable flow path and integrated with the upstream perfusion operation, followed by membrane chromatography on large-scale adsorber capsules in rapid cycling mode. Implementation of the platform at commercial scale for a new product candidate led to a yield improvement of 40% compared to the conventional process technology, while product quality has been shown to be more consistently high. Over 1,000,000 L of cell culture harvest have been processed with 100% success rate to date, demonstrating the robustness of the new platform process in GMP manufacturing. While membrane chromatography is well established for polishing in flow-through mode, this is its first commercial-scale application for bind/elute chromatography in the biopharmaceutical industry and demonstrates its potential in particular for manufacturing of potent, low-dose biopharmaceuticals. Copyright © 2012 Wiley Periodicals, Inc.

Single particle ICP-MS combined with a data evaluastion tool as a routine techique for the analysis of nanoparticles in complex matrices

NARCIS (Netherlands)

Peters, R.J.B.; Herrera-Rivera, Z.; Undas, A.K.; Lee, van der M.K.; Marvin, H.J.P.; Bouwmeester, H.; Weigel, S.

2015-01-01

Detection and characterization of nanoparticles (NPs) in complex media as consumer products, food and toxicological test media is an essential part of understanding the potential benefits and risks of the application of nanoparticles. Single particle ICP-MS (spICP-MS) was studied as a screening tool

Design, Fabrication and Initial Testing of a Large Bore Single Aperture 1 m Long Superconducting Dipole Made with Phenolic Inserts

CERN Document Server

Boschmann, H; Kirby, G A; Lucas, J; Ostojic, R; Russenschuck, Stephan; Siemko, A; Vanenkov, I; Weterings, W

1997-01-01

In the framework of the LHC magnet development programme, a large bore single aperture 1-meter long superconducting dipole has been built in collaboration with HOLEC. The magnet features a single layer coil wound using the LHC main dipole outer layer cable, phenolic inserts, and a keyed two part structural iron yoke. This paper presents the magnetic and mechanical design and optimisation of the magnet. We describe the coil winding and curing, and present the construction and assembly procedures. Finally we report on the mechanical behaviour during assembly and cooling, and present the magnet training behaviour.

Emergence of biological complexity: Criticality, renewal and memory

International Nuclear Information System (INIS)

Grigolini, Paolo

2015-01-01

The key purpose of this article is to establish a connection between two emerging fields of research in theoretical biology. The former focuses on the concept of criticality borrowed from physics that is expected to be extensible to biology through a robust theoretical approach that although not yet available shall eventually shed light into the origin of cognition. The latter, largely based on the tracking of single molecules diffusing in biological cells, is bringing to the general attention the need to go beyond the ergodic assumption currently done in the traditional statistical physics. We show that replacing critical slowing down with temporal complexity explains why biological systems at criticality are resilient and why long-range correlations are compatible with the free-will condition necessary for the emergence of cognition. Temporal complexity generates ergodicity breakdown and requires new forms of response of complex systems to external stimuli. We concisely illustrate these new forms of information transport and we also address the challenging issue of combining temporal complexity with coherence and renewal with infinite memory.

Complex Networks

CERN Document Server

Evsukoff, Alexandre; González, Marta

2013-01-01

In the last decade we have seen the emergence of a new inter-disciplinary field focusing on the understanding of networks which are dynamic, large, open, and have a structure sometimes called random-biased. The field of Complex Networks is helping us better understand many complex phenomena such as the spread of  deseases, protein interactions, social relationships, to name but a few. Studies in Complex Networks are gaining attention due to some major scientific breakthroughs proposed by network scientists helping us understand and model interactions contained in large datasets. In fact, if we could point to one event leading to the widespread use of complex network analysis is the availability of online databases. Theories of Random Graphs from Erdös and Rényi from the late 1950s led us to believe that most networks had random characteristics. The work on large online datasets told us otherwise. Starting with the work of Barabási and Albert as well as Watts and Strogatz in the late 1990s, we now know th...

Compressive Force Spectroscopy: From Living Cells to Single Proteins.

Science.gov (United States)

Wang, Jiabin; Liu, Meijun; Shen, Yi; Sun, Jielin; Shao, Zhifeng; Czajkowsky, Daniel Mark

2018-03-23

One of the most successful applications of atomic force microscopy (AFM) in biology involves monitoring the effect of force on single biological molecules, often referred to as force spectroscopy. Such studies generally entail the application of pulling forces of different magnitudes and velocities upon individual molecules to resolve individualistic unfolding/separation pathways and the quantification of the force-dependent rate constants. However, a less recognized variation of this method, the application of compressive force, actually pre-dates many of these "tensile" force spectroscopic studies. Further, beyond being limited to the study of single molecules, these compressive force spectroscopic investigations have spanned samples as large as living cells to smaller, multi-molecular complexes such as viruses down to single protein molecules. Correspondingly, these studies have enabled the detailed characterization of individual cell states, subtle differences between seemingly identical viral structures, as well as the quantification of rate constants of functionally important, structural transitions in single proteins. Here, we briefly review some of the recent achievements that have been obtained with compressive force spectroscopy using AFM and highlight exciting areas of its future development.

Hybrid Nanomaterials with Single-Site Catalysts by Spatially Controllable Immobilization of Nickel Complexes via Photoclick Chemistry for Alkene Epoxidation.

Science.gov (United States)

Ghosh, Dwaipayan; Febriansyah, Benny; Gupta, Disha; Ng, Leonard Kia-Sheun; Xi, Shibo; Du, Yonghua; Baikie, Tom; Dong, ZhiLi; Soo, Han Sen

2018-05-22

Catalyst deactivation is a persistent problem not only for the scientific community but also in industry. Isolated single-site heterogeneous catalysts have shown great promise to overcome these problems. Here, a versatile anchoring strategy for molecular complex immobilization on a broad range of semiconducting or insulating metal oxide ( e. g., titanium dioxide, mesoporous silica, cerium oxide, and tungsten oxide) nanoparticles to synthesize isolated single-site catalysts has been studied systematically. An oxidatively stable anchoring group, maleimide, is shown to form covalent linkages with surface hydroxyl functionalities of metal oxide nanoparticles by photoclick chemistry. The nanocomposites have been thoroughly characterized by techniques including UV-visible diffuse reflectance spectroscopy, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, infrared spectroscopy, and X-ray absorption spectroscopy (XAS). The IR spectroscopic studies confirm the covalent linkages between the maleimide group and surface hydroxyl functionalities of the oxide nanoparticles. The hybrid nanomaterials function as highly efficient catalysts for essentially quantitative oxidations of terminal and internal alkenes and show molecular catalyst product selectivities even in more eco-friendly solvents. XAS studies verify the robustness of the catalysts after several catalytic cycles. We have applied the photoclick anchoring methodology to precisely control the deposition of a luminescent variant of our catalyst on the metal oxide nanoparticles. Overall, we demonstrate a general approach to use irradiation to anchor molecular complexes on oxide nanoparticles to create recyclable, hybrid, single-site catalysts that function with high selectivity in a broad range of solvents. We have achieved a facile, spatially and temporally controllable photoclick method that can potentially be extended to other ligands, catalysts, functional molecules, and surfaces.

Workshop on Recommendation in Complex Scenarios (ComplexRec 2017)

DEFF Research Database (Denmark)

Bogers, Toine; Koolen, Marijn; Mobasher, Bamshad

2017-01-01

Recommendation algorithms for ratings prediction and item ranking have steadily matured during the past decade. However, these state-of-the-art algorithms are typically applied in relatively straightforward scenarios. In reality, recommendation is often a more complex problem: it is usually just...... a single step in the user's more complex background need. These background needs can often place a variety of constraints on which recommendations are interesting to the user and when they are appropriate. However, relatively little research has been done on these complex recommendation scenarios....... The ComplexRec 2017 workshop addressed this by providing an interactive venue for discussing approaches to recommendation in complex scenarios that have no simple one-size-fits-all-solution....

Growth of large size lithium niobate single crystals of high quality by tilting-mirror-type floating zone method

Energy Technology Data Exchange (ETDEWEB)

Sarker, Abdur Razzaque, E-mail: razzaque_ru2000@yahoo.com [Department of Physics, University of Rajshahi (Bangladesh)

2016-05-15

Large size high quality LiNbO{sub 3} single crystals were grown successfully by tilting-mirror-type floating zone (TMFZ) technique. The grown crystals were characterized by X-ray diffraction, etch pits density measurement, Impedance analysis, Vibrating sample magnetometry (VSM) and UV-Visible spectrometry. The effect of mirror tilting during growth on the structural, electrical, optical properties and defect density of the LiNbO{sub 3} crystals were investigated. It was found that the defect density in the crystals reduced for tilting the mirror in the TMFZ method. The chemical analysis revealed that the grown crystals were of high quality with uniform composition. The single crystals grown by TMFZ method contains no low-angle grain boundaries, indicating that they can be used for high efficiency optoelectronic devices. (author)

A terminal fluoride ligand generates axial magnetic anisotropy in dysprosium complexes

Energy Technology Data Exchange (ETDEWEB)

Norel, Lucie [Department of Chemistry, University of California, Berkeley, CA (United States); Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) - UMR 6226, Rennes (France); Darago, Lucy E.; Chakarawet, Khetpakorn; Gonzalez, Miguel I.; Olshansky, Jacob H.; Long, Jeffrey R. [Department of Chemistry, University of California, Berkeley, CA (United States); Le Guennic, Boris; Rigaut, Stephane [Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) - UMR 6226, Rennes (France)

2018-02-12

The first dysprosium complexes with a terminal fluoride ligand are obtained as air-stable compounds. The strong, highly electrostatic dysprosium-fluoride bond generates a large axial crystal-field splitting of the J=15/2 ground state, as evidenced by high-resolution luminescence spectroscopy and correlated with the single-molecule magnet behavior through experimental magnetic susceptibility data and ab initio calculations. (copyright 2018 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

World, We Have Problems: Simulation for Large Complex, Risky Projects, and Events

Science.gov (United States)

Elfrey, Priscilla

2010-01-01

Prior to a spacewalk during the NASA STS/129 mission in November 2009, Columbia Broadcasting System (CBS) correspondent William Harwood reported astronauts, "were awakened again", as they had been the day previously. Fearing something not properly connected was causing a leak, the crew, both on the ground and in space, stopped and checked everything. The alarm proved false. The crew did complete its work ahead of schedule, but the incident reminds us that correctly connecting hundreds and thousands of entities, subsystems and systems, finding leaks, loosening stuck valves, and adding replacements to very large complex systems over time does not occur magically. Everywhere major projects present similar pressures. Lives are at - risk. Responsibility is heavy. Large natural and human-created disasters introduce parallel difficulties as people work across boundaries their countries, disciplines, languages, and cultures with known immediate dangers as well as the unexpected. NASA has long accepted that when humans have to go where humans cannot go that simulation is the sole solution. The Agency uses simulation to achieve consensus, reduce ambiguity and uncertainty, understand problems, make decisions, support design, do planning and troubleshooting, as well as for operations, training, testing, and evaluation. Simulation is at the heart of all such complex systems, products, projects, programs, and events. Difficult, hazardous short and, especially, long-term activities have a persistent need for simulation from the first insight into a possibly workable idea or answer until the final report perhaps beyond our lifetime is put in the archive. With simulation we create a common mental model, try-out breakdowns of machinery or teamwork, and find opportunity for improvement. Lifecycle simulation proves to be increasingly important as risks and consequences intensify. Across the world, disasters are increasing. We anticipate more of them, as the results of global warming

Construction Method Study For Installation Of A Large Riser In A Single-Shell Tank

International Nuclear Information System (INIS)

Adkisson, D.A.

2010-01-01

This study evaluates and identifies a construction method for cutting a hole in a single-shell tank dome. This study also identifies and evaluates vendors for performing the cut. Single-shell tanks (SST) in the 241-C tank farm are currently being retrieved using various retrieval technologies (e.g., modified sluicing). The Hanford Federal Facility Agreement and Consent Order require that the SSTs be retrieved to less than 360 cubic feet of radioactive waste. The current technologies identified and deployed for tank retrieval have not been able to retrieve waste in accordance with the Hanford Federal Facility Agreement and Consent Order. As such, alternative retrieval systems have been proposed and are currently under construction that will have the ability to retrieve waste to this defined level. The proposed retrieval systems will not fit down existing risers. New risers will need to be installed to provide the retrieval systems access to the inside of the SSTs. The purpose of this study is two-fold. The first objective is to identify multiple concrete cutting technologies and perform an initial pre-screening, evaluate the technologies identified for more in-depth analysis, and recommend a technology/methodology for cutting a hole in the tank dome. The identified/pre-screened methods will be evaluated based on the following criteria: (1) Maturity/complexity; (2) Waste generation; (3) Safety; (4) Cost; and (5) Schedule. Once the preferred method is identified to cut the hole in the tank dome, the second objective is to identify, evaluate, and recommend a vendor for the technology selected that will perform the cutting process.

Laser desorption single-conformation UV and IR spectroscopy of the sulfonamide drug sulfanilamide, the sulfanilamide-water complex, and the sulfanilamide dimer.

Science.gov (United States)

Uhlemann, Thomas; Seidel, Sebastian; Müller, Christian W

2017-06-07

We have studied the conformational preferences of the sulfonamide drug sulfanilamide, its dimer, and its monohydrated complex through laser desorption single-conformation UV and IR spectroscopy in a molecular beam. Based on potential energy curves for the inversion of the anilinic and the sulfonamide NH 2 groups calculated at DFT level, we suggest that the zero-point level wave function of the sulfanilamide monomer is appreciably delocalized over all four conformer wells. The sulfanilamide dimer, and the monohydrated complex each exhibit a single isomer in the molecular beam. The isomeric structures of the sulfanilamide dimer and the monohydrated sulfanilamide complex were assigned based on their conformer-specific IR spectra in the NH and OH stretch region. Quantum Theory of Atoms in Molecules (QTAIM) analysis of the calculated electron density in the water complex suggests that the water molecule is bound side-on in a hydrogen bonding pocket, donating one O-HO[double bond, length as m-dash]S hydrogen bond and accepting two hydrogen bonds, a NHO and a CHO hydrogen bond. QTAIM analysis of the dimer electron density suggests that the C i symmetry dimer structure exhibits two dominating N-HO[double bond, length as m-dash]S hydrogen bonds, and three weaker types of interactions: two CHO bonds, two CHN bonds, and a chalcogen OO interaction. Most interestingly, the molecular beam dimer structure closely resembles the R dimer unit - the dimer unit with the greatest interaction energy - of the α, γ, and δ crystal polymorphs. Interacting Quantum Atoms analysis provides evidence that the total intermolecular interaction in the dimer is dominated by the short-range exchange-correlation contribution.

Large Differences in the Optical Spectrum Associated with the Same Complex: The Effect of the Anisotropy of the Embedding Lattice

DEFF Research Database (Denmark)

Aramburu, José Antonio; García-Fernández, Pablo; García Lastra, Juan Maria

2017-01-01

of the electric field created by the rest of lattice ions over the complex. To illustrate this concept we analyze the origin of the surprisingly large differences in the d–d optical transitions of two systems containing square-planar CuF42– complexes, CaCuF4, and center II in Cu2+-doped Ba2ZnF6, even though...... the Cu2+–F–distance difference is just found to be 1%. Using a minimalist first-principles model we show that the different morphology of the host lattices creates an anisotropic field that red-shifts the in vacuo complex transitions to the 1.25–1.70 eV range in CaCuF4, while it blue-shifts them to the 1...

Gold and Nickel Extended Thiophenic-TTF Bisdithiolene Complexes

Directory of Open Access Journals (Sweden)

Rafaela A. L. Silva

2018-02-01

Full Text Available Gold and nickel bisdithiolene complexes with methyl and tert-butyl substituted thiophenetetrathiafulavalenedithiolate ligands (α-mtdt and α-tbtdt were prepared and characterized. These complexes were obtained, under anaerobic conditions, as tetrabutylammonium salts. The diamagnetic gold monoanion (n-Bu4N[Au(α-mtdt2] (3 and nickel dianionic species (n-Bu4Nx[Ni(α-mtdt2] (x = 1,2 (4 were similar to the related non-substituted extended thiophenic-TTF (TTF = tetrathiafulvalene bisdithiolenes. However the introduction of the large, bulky substituent tert-butyl, led to the formation of a Au (I dinuclear complex, (n-Bu4N2[Au2(α-tbtdt2] (5. The neutral methyl substituted gold and nickel complexes were easily obtained through air or iodine exposure as polycrystalline or amorphous fine powder. [Au(α-mtdt2] (6 and [Ni(α-mtdt2] (7 polycrystalline samples display properties of a metallic system with a room temperature electrical conductivity of 0.32 S/cm and ≈4 S/cm and a thermoelectric power of ≈5 µV/K and ≈32 µV/K, respectively. While [Au(α-mtdt2] (6 presented a Pauli-like magnetic susceptibility typical of conducting systems, in [Ni(α-mtdt2] (7 large magnetic susceptibilities indicative of high spin states were observed. Both electric transport properties and magnetic properties for gold and nickel [M(α-mtdt2] are indicative that these compounds are single component molecular conductors.

The Detection of Hot Cores and Complex Organic Molecules in the Large Magellanic Cloud

Science.gov (United States)

Sewiło, Marta; Indebetouw, Remy; Charnley, Steven B.; Zahorecz, Sarolta; Oliveira, Joana M.; van Loon, Jacco Th.; Ward, Jacob L.; Chen, C.-H. Rosie; Wiseman, Jennifer; Fukui, Yasuo; Kawamura, Akiko; Meixner, Margaret; Onishi, Toshikazu; Schilke, Peter

2018-02-01

We report the first extragalactic detection of the complex organic molecules (COMs) dimethyl ether (CH3OCH3) and methyl formate (CH3OCHO) with the Atacama Large Millimeter/submillimeter Array (ALMA). These COMs, together with their parent species methanol (CH3OH), were detected toward two 1.3 mm continuum sources in the N 113 star-forming region in the low-metallicity Large Magellanic Cloud (LMC). Rotational temperatures ({T}{rot}∼ 130 K) and total column densities ({N}{rot}∼ {10}16 cm‑2) have been calculated for each source based on multiple transitions of CH3OH. We present the ALMA molecular emission maps for COMs and measured abundances for all detected species. The physical and chemical properties of two sources with COMs detection, and the association with H2O and OH maser emission, indicate that they are hot cores. The fractional abundances of COMs scaled by a factor of 2.5 to account for the lower metallicity in the LMC are comparable to those found at the lower end of the range in Galactic hot cores. Our results have important implications for studies of organic chemistry at higher redshift.

Self-assembly of Terbium(III)-based metal-organic complexes with two-photon absorbing active

Science.gov (United States)

Li, Dandan; Shao, Nanqi; Sun, Xianshun; Zhang, Guocui; Li, Shengli; Zhou, Hongping; Wu, Jieying; Tian, Yupeng

2014-12-01

Hybrid complexes based on D-π-A type dyes p-aminostyryl-pyridinum and Terbium(III) complex anion (1, 2) have been synthesized by ionic exchange reaction. Meanwhile two different alkyl-substituted amino groups were used as electron donors in organic dyes cations. The synthesized complexes were characterized by element analysis. In addition, the structural features of them were systematic studied by single crystal X-ray diffraction analysis. Their linear properties have been systematically investigated by absorption spectra and fluorescence, the results show that the energy transfer takes place from the trans-4-[4‧-(N,N-diethylamino)styryl]-N-methyl pyridinium (2‧) cation to Tb(III). In addition, complex 2 exhibit a large two-photon absorption coefficient β: 0.044 cm/GW at 710 nm.

Application of X-ray single crystal diffractometry to investigation of Np(5) complexes with n-donor ligands

International Nuclear Information System (INIS)

Andreev, G.

2007-01-01

Full text of publication follows. We present here some results of application of conventional X-ray single crystal diffractometry to the research on the interaction of Np(V) with N-donor ligands. Compounds that can coordinate to actinides through one or several nitrogen atoms are of a great variety and occur widely in the biosphere. For example, imidazole, pyridine and their derivatives are the building blocks of many biologically important molecules; triazines are known to occur in some aquatic plants. The presence of anthropogenic organic agents like amine-N-carboxylic acids in surface waters has the potential to re-mobilize metals from sediments and aquifers and to influence their bioavailability. The interaction of radionuclides with such ligands needs to be studied in detail to give fundamental understanding the conditions of the incorporation of long lived a-emitters (Np and Pu primarily) into the food chain. Another aspect of the same problem is the design of new chelating ligands for selective co-ordination of actinide ions as an alternative to the traditional sequestering agents. The problem of the separation of long-lived minor actinides and their transmutation also calls for design of new highly selective ligands for solvent extraction. Polydentate N-donor ligands are now considered to be very promising. A detailed study of structural chemistry is crucial for understanding the relationship between the architecture of the ligands and their binding affinity for actinides. The X-ray single crystal diffractometry became conventional technique as applied to the investigation of actinides in spite of difficulties regarding safe handling of radionuclides. This technique provides unambiguous information about modes of the ligand co-ordination to the metal ion and geometrical parameters of complexes. Moreover, the employment of a synchrotron radiation shows considerable promise for determination of solid state structures as well as obtaining structural

A novel non-enzymatic hydrogen peroxide sensor based on single walled carbon nanotubes-manganese complex modified glassy carbon electrode

Energy Technology Data Exchange (ETDEWEB)

Salimi, Abdollah, E-mail: absalimi@uok.ac.i [Department of Chemistry, University of Kurdistan, P.O. Box 416, Sanandaj (Iran, Islamic Republic of); Research Center for Nanotechnology, University of Kurdistan, P.O. Box 416, Sanandaj (Iran, Islamic Republic of); Mahdioun, Monierosadat; Noorbakhsh, Abdollah [Department of Chemistry, University of Kurdistan, P.O. Box 416, Sanandaj (Iran, Islamic Republic of); Abdolmaleki, Amir [Department of Chemistry, Isfahan University of Technology, Isfahan, 84156/83111 (Iran, Islamic Republic of); Ghavami, Raoof [Department of Chemistry, University of Kurdistan, P.O. Box 416, Sanandaj (Iran, Islamic Republic of)

2011-03-30

A simple procedure was developed to prepare a glassy carbon (GC) electrode modified with single wall carbon nanotubes (SWCNTs) and phenazine derivative of Mn-complex. With immersing the GC/CNTs modified electrode into Mn-complex solution for a short period of time 20-100 s, a stable thin layer of the complex was immobilized onto electrode surface. Modified electrode showed a well defined redox couples at wide pH range (1-12). The surface coverages and heterogeneous electron transfer rate constants (k{sub s}) of immobilized Mn-complex were approximately 1.58 x 10{sup -10} mole cm{sup -2} and 48.84 s{sup -1}. The modified electrode showed excellent electrocatalytic activity toward H{sub 2}O{sub 2} reduction. Detection limit, sensitivity, linear concentration range and k{sub cat} for H{sub 2}O{sub 2} were, 0.2 {mu}M and 692 nA {mu}M{sup -1} cm{sup -2}, 1 {mu}M to 1.5 mM and 7.96({+-}0.2) x 10{sup 3} M{sup -1} s{sup -1}, respectively. Compared to other modified electrodes, this electrode has many advantageous such as remarkable catalytic activity, good reproducibility, simple preparation procedure and long term stability.

Single-Sex Classrooms

Science.gov (United States)

Protheroe, Nancy

2009-01-01

Although single-sex education was once the norm in the U.S., the practice has largely been confined to private schools for more than a century. However, with the introduction of the final version of the U.S. Department of Education's so-called single-sex regulations in 2006, public schools were allowed greater flexibility to offer single-sex…

Magnetic phase transitions and large mass enhancement in single crystal CaFe4As3

International Nuclear Information System (INIS)

Zhang Xiao-Dong; Wu Wei; Zheng Ping; Wang Nan-Lin; Luo Jian-Lin

2012-01-01

High quality single crystal CaFe 4 As 3 was grown by using the Sn flux method. Unlike layered CaFe 2 As 2 , CaFe 4 As 3 crystallizes in an orthorhombic three-dimensional structure. Two magnetic ordering transitions are observed at ∼ 90 K and ∼ 27 K, respectively. The high temperature transition is an antiferromagnetic(AF) ordering transition. However, the low temperature transition shows complex properties. It shows a ferromagnetic-like transition when a field is applied along b-axis, while antiferromagnetism-like transition when a field is applied perpendicular to b-axis. These results suggest that the low temperature transition at 27 K is a first-order transition from an AF state to a canted AF state. In addition, the low temperature electron specific heat coefficient reaches as high as 143 mJ/mol·K 2 , showing a heavy fermion behavior. (rapid communication)

Application of plant metabonomics in quality assessment for large-scale production of traditional Chinese medicine.

Science.gov (United States)

Ning, Zhangchi; Lu, Cheng; Zhang, Yuxin; Zhao, Siyu; Liu, Baoqin; Xu, Xuegong; Liu, Yuanyan

2013-07-01

The curative effects of traditional Chinese medicines are principally based on the synergic effect of their multi-targeting, multi-ingredient preparations, in contrast to modern pharmacology and drug development that often focus on a single chemical entity. Therefore, the method employing a few markers or pharmacologically active constituents to assess the quality and authenticity of the complex preparations has a number of severe challenges. Metabonomics can provide an effective platform for complex sample analysis. It is also reported to be applied to the quality analysis of the traditional Chinese medicine. Metabonomics enables comprehensive assessment of complex traditional Chinese medicines or herbal remedies and sample classification of diverse biological statuses, origins, or qualities in samples, by means of chemometrics. Identification, processing, and pharmaceutical preparation are the main procedures in the large-scale production of Chinese medicinal preparations. Through complete scans, plants metabonomics addresses some of the shortfalls of single analyses and presents a considerable potential to become a sharp tool for traditional Chinese medicine quality assessment. Georg Thieme Verlag KG Stuttgart · New York.

Power efficient low complexity precoding for massive MIMO systems

KAUST Repository

Sifaou, Houssem

2014-12-01

This work aims at designing a low-complexity precoding technique in the downlink of a large-scale multiple-input multiple-output (MIMO) system in which the base station (BS) is equipped with M antennas to serve K single-antenna user equipments. This is motivated by the high computational complexity required by the widely used zero-forcing or regularized zero-forcing precoding techniques, especially when K grows large. To reduce the computational burden, we adopt a precoding technique based on truncated polynomial expansion (TPE) and make use of the asymptotic analysis to compute the deterministic equivalents of its corresponding signal-to-interference-plus-noise ratios (SINRs) and transmit power. The asymptotic analysis is conducted in the regime in which M and K tend to infinity with the same pace under the assumption that imperfect channel state information is available at the BS. The results are then used to compute the TPE weights that minimize the asymptotic transmit power while meeting a set of target SINR constraints. Numerical simulations are used to validate the theoretical analysis. © 2014 IEEE.

Physics of Complex Polymeric Molecules

Science.gov (United States)

Kelly, Joshua Walter

The statistical physics of complex polymers with branches and circuits is the topic of this dissertation. An important motivation are large, single-stranded (ss) RNA molecules. Such molecules form complex ``secondary" and ``tertiary" structures that can be represented as branched polymers with circuits. Such structures are in part directly determined by the nucleotide sequence and in part subject to thermal fluctuations. The polymer physics literature on molecules in this class has mostly focused on randomly branched polymers without circuits while there has been minimal research on polymers with specific structures and on polymers that contain circuits. The dissertation is composed of three parts: Part I studies branched polymers with thermally fluctuating structure confined to a potential well as a simple model for the encapsidation of viral RNA. Excluded volume interactions were ignored. In Part II, I apply Flory theory to the study of the encapsidation of viral ss RNA molecules with specific branched structures, but without circuits, in the presence of excluded volume interaction. In Part III, I expand on Part II and consider complex polymers with specific structure including both branching and circuits. I introduce a method based on the mathematics of Laplacian matrices that allows me to calculate density profiles for such molecules, which was not possible within Flory theory.

The MARVEL domain protein, Singles Bar, is required for progression past the pre-fusion complex stage of myoblast fusion.

Science.gov (United States)

Estrada, Beatriz; Maeland, Anne D; Gisselbrecht, Stephen S; Bloor, James W; Brown, Nicholas H; Michelson, Alan M

2007-07-15

Multinucleated myotubes develop by the sequential fusion of individual myoblasts. Using a convergence of genomic and classical genetic approaches, we have discovered a novel gene, singles bar (sing), that is essential for myoblast fusion. sing encodes a small multipass transmembrane protein containing a MARVEL domain, which is found in vertebrate proteins involved in processes such as tight junction formation and vesicle trafficking where--as in myoblast fusion--membrane apposition occurs. sing is expressed in both founder cells and fusion competent myoblasts preceding and during myoblast fusion. Examination of embryos injected with double-stranded sing RNA or embryos homozygous for ethane methyl sulfonate-induced sing alleles revealed an identical phenotype: replacement of multinucleated myofibers by groups of single, myosin-expressing myoblasts at a stage when formation of the mature muscle pattern is complete in wild-type embryos. Unfused sing mutant myoblasts form clusters, suggesting that early recognition and adhesion of these cells are unimpaired. To further investigate this phenotype, we undertook electron microscopic ultrastructural studies of fusing myoblasts in both sing and wild-type embryos. These experiments revealed that more sing mutant myoblasts than wild-type contain pre-fusion complexes, which are characterized by electron-dense vesicles paired on either side of the fusing plasma membranes. In contrast, embryos mutant for another muscle fusion gene, blown fuse (blow), have a normal number of such complexes. Together, these results lead to the hypothesis that sing acts at a step distinct from that of blow, and that sing is required on both founder cell and fusion-competent myoblast membranes to allow progression past the pre-fusion complex stage of myoblast fusion, possibly by mediating fusion of the electron-dense vesicles to the plasma membrane.

Single-electron transfer in palladium complexes of 1,4-naphthoquinone-containing bis(pyrazol-1-yl)methane ligands.

Science.gov (United States)

Scheuermann, Sebastian; Sarkar, Biprajit; Bolte, Michael; Bats, Jan W; Lerner, Hans-Wolfram; Wagner, Matthias

2009-10-05

A 1,4-naphthoquinone-substituted bis(pyrazol-1-yl)methane ligand (N--N) has been synthesized and transformed into its corresponding Pd(II) chelate complex [(N--N)PdCl(2)]. Both N--N and [(N--N)PdCl(2)] have been fully characterized by NMR spectroscopy, spectro-electrochemistry, and X-ray crystallography. After treatment of [(N--N)PdCl(2)] with NEt(3), the signature of a 1,4-naphthosemiquinonate radical is visible in the UV-vis- and electron paramagnetic resonance (EPR) spectrum of the reaction mixture; the free ligand N--N does not react with NEt(3) under the conditions applied. It is therefore concluded that NEt(3) first reduces the Pd(II)-ion of [(N--N)PdCl(2)] to the zero-valent state and that this reaction is followed by a single-electron transfer from the metal atom to the 1,4-naphthoquinone moiety. The complex has been specifically designed to disfavor any direct Pd-to-naphthoquinone coordination. Electron transfer thus proceeds through space or, less likely, via sigma-bonds of the ligand framework.

Highly selective single-use fluoride ion optical sensor based on aluminum(III)-salen complex in thin polymeric film

International Nuclear Information System (INIS)

Badr, Ibrahim H.A.; Meyerhoff, Mark E.

2005-01-01

A highly selective optical sensor for fluoride ion based on the use of an aluminum(III)-salen complex as an ionophore within a thin polymeric film is described. The sensor is prepared by embedding the aluminum(III)-salen ionophore and a suitable lipophilic pH-sensitive indicator (ETH-7075) in a plasticized poly(vinyl chloride) (PVC) film. Optical response to fluoride occurs due to fluoride extraction into the polymer via formation of a strong complex with the aluminum(III)-salen species. Co-extraction of protons occurs simultaneously, with protonation of the indicator dye yielding the optical response at 529 nm. Films prepared using dioctylsebacate (DOS) are shown to exhibit better response (e.g., linear range, detection limit, and optical signal stability) compared to those prepared using ortho-nitrophenyloctyl ether (o-NPOE). Films formulated with aluminum(III)-salen and ETH-7075 indicator in 2 DOS:1 PVC, exhibit a significantly enhanced selectivity for fluoride over a wide range of lipophilic anions including salicylate, perchlorate, nitrate, and thiocyanate. The optimized films exhibit a sub-micromolar detection limit, using glycine-phosphate buffer, pH 3.00, as the test sample. The response times of the fluoride optical sensing films are in the range of 1-10 min depending on the fluoride ion concentration in the sample. The sensor exhibits very poor reversibility owing to a high co-extraction constant (log K = 8.5 ± 0.4), indicating that it can best be employed as a single-use transduction device. The utility of the aluminum(III)-salen based fluoride sensitive films as single-use sensors is demonstrated by casting polymeric films on the bottom of standard polypropylene microtiter plate wells (96 wells/plate). The modified microtiter plate optode format sensors exhibit response characteristics comparable to the classical optode films cast on quartz slides. The modified microtiter is utilized for the analysis of fluoride in diluted anti-cavity fluoride rinse

Investigation of the complexity of streamflow fluctuations in a large heterogeneous lake catchment in China

Science.gov (United States)

Ye, Xuchun; Xu, Chong-Yu; Li, Xianghu; Zhang, Qi

2018-05-01

The occurrence of flood and drought frequency is highly correlated with the temporal fluctuations of streamflow series; understanding of these fluctuations is essential for the improved modeling and statistical prediction of extreme changes in river basins. In this study, the complexity of daily streamflow fluctuations was investigated by using multifractal detrended fluctuation analysis (MF-DFA) in a large heterogeneous lake basin, the Poyang Lake basin in China, and the potential impacts of human activities were also explored. Major results indicate that the multifractality of streamflow fluctuations shows significant regional characteristics. In the study catchment, all the daily streamflow series present a strong long-range correlation with Hurst exponents bigger than 0.8. The q-order Hurst exponent h( q) of all the hydrostations can be characterized well by only two parameters: a (0.354 ≤ a ≤ 0.384) and b (0.627 ≤ b ≤ 0.677), with no pronounced differences. Singularity spectrum analysis pointed out that small fluctuations play a dominant role in all daily streamflow series. Our research also revealed that both the correlation properties and the broad probability density function (PDF) of hydrological series can be responsible for the multifractality of streamflow series that depends on watershed areas. In addition, we emphasized the relationship between watershed area and the estimated multifractal parameters, such as the Hurst exponent and fitted parameters a and b from the q-order Hurst exponent h( q). However, the relationship between the width of the singularity spectrum (Δ α) and watershed area is not clear. Further investigation revealed that increasing forest coverage and reservoir storage can effectively enhance the persistence of daily streamflow, decrease the hydrological complexity of large fluctuations, and increase the small fluctuations.

Robust Cell Detection for Large-Scale 3D Microscopy Using GPU-Accelerated Iterative Voting

Directory of Open Access Journals (Sweden)

Leila Saadatifard

2018-04-01

Full Text Available High-throughput imaging techniques, such as Knife-Edge Scanning Microscopy (KESM,are capable of acquiring three-dimensional whole-organ images at sub-micrometer resolution. These images are challenging to segment since they can exceed several terabytes (TB in size, requiring extremely fast and fully automated algorithms. Staining techniques are limited to contrast agents that can be applied to large samples and imaged in a single pass. This requires maximizing the number of structures labeled in a single channel, resulting in images that are densely packed with spatial features. In this paper, we propose a three-dimensional approach for locating cells based on iterative voting. Due to the computational complexity of this algorithm, a highly efficient GPU implementation is required to make it practical on large data sets. The proposed algorithm has a limited number of input parameters and is highly parallel.

Biased Brownian motion mechanism for processivity and directionality of single-headed myosin-VI.

Science.gov (United States)

Iwaki, Mitsuhiro; Iwane, Atsuko Hikikoshi; Ikebe, Mitsuo; Yanagida, Toshio

2008-01-01

Conventional form to function as a vesicle transporter is not a 'single molecule' but a coordinated 'two molecules'. The coordinated two molecules make it complicated to reveal its mechanism. To overcome the difficulty, we adopted a single-headed myosin-VI as a model protein. Myosin-VI is an intracellular vesicle and organelle transporter that moves along actin filaments in a direction opposite to most other known myosin classes. The myosin-VI was expected to form a dimer to move processively along actin filaments with a hand-over-hand mechanism like other myosin organelle transporters. However, wild-type myosin-VI was demonstrated to be monomer and single-headed, casting doubt on its processivity. Using single molecule techniques, we show that green fluorescent protein (GFP)-fused single-headed myosin-VI does not move processively. However, when coupled to a 200 nm polystyrene bead (comparable to an intracellular vesicle in size) at a ratio of one head per bead, single-headed myosin-VI moves processively with large (40 nm) steps. Furthermore, we found that a single-headed myosin-VI-bead complex moved more processively in a high-viscous solution (40-fold higher than water) similar to cellular environment. Because diffusion of the bead is 60-fold slower than myosin-VI heads alone in water, we propose a model in which the bead acts as a diffusional anchor for the myosin-VI, enhancing the head's rebinding following detachment and supporting processive movement of the bead-monomer complex. This investigation will help us understand how molecular motors utilize Brownian motion in cells.

Single Incision Laparoscopic Surgery for a Large Endometriotic Cyst

African Journals Online (AJOL)

In the last decade, laparoscopy has become the standard treatment for many gynecological conditions.[1,2] Today, laparoscopy is hailed as the standard approach in the surgical treatment of benign adnexal pathology.[1,2] Attempts to minimize access-related injuries and complications resulted in development of single port ...

A Project Management Approach to Using Simulation for Cost Estimation on Large, Complex Software Development Projects

Science.gov (United States)

Mizell, Carolyn; Malone, Linda

2007-01-01

It is very difficult for project managers to develop accurate cost and schedule estimates for large, complex software development projects. None of the approaches or tools available today can estimate the true cost of software with any high degree of accuracy early in a project. This paper provides an approach that utilizes a software development process simulation model that considers and conveys the level of uncertainty that exists when developing an initial estimate. A NASA project will be analyzed using simulation and data from the Software Engineering Laboratory to show the benefits of such an approach.

Large, cold, and unusual molecular cloud in Monoceros

International Nuclear Information System (INIS)

Maddalena, R.J.; Thaddeus, P.; and Columbia University)

1985-01-01

Observations of the J = 1 → 0 rotational transition of CO near the galactic plane in Monoceros (lroughly-equal216 0 ) reveal a molecular cloud with unusually low peak CO temperatures (T/sub R/ -1 ) typical of much warmer clouds. At the assumed distance of 3 kpc, the cloud is large (250 x 100 pc), has a mass of 7-11 x 10 5 M/sub sun/, and is well removed from the galactic midplane (130 pc). Except for a possible H II region, all the signs of star formation usually shown by clouds of comparable mass are missing. The cloud, unlike cloud complexes of similar size, is a single, continuous object that apparently has not been torn apart by star formation. Clouds with such properties are rare in the Galaxy; only one or two similar objects have been found. We discuss the possibility that the cloud is young and not yet forming stars but will evolve into a typical cloud complex once star formation begins

Ecological complexity buffers the impacts of future climate on marine consumers

Science.gov (United States)

Goldenberg, Silvan U.; Nagelkerken, Ivan; Marangon, Emma; Bonnet, Angélique; Ferreira, Camilo M.; Connell, Sean D.

2018-03-01

Ecological complexity represents a network of interacting components that either propagate or counter the effects of environmental change on individuals and communities1-3. Yet, our understanding of the ecological imprint of ocean acidification (elevated CO2) and climate change (elevated temperature) is largely based on reports of negative effects on single species in simplified laboratory systems4,5. By combining a large mesocosm experiment with a global meta-analysis, we reveal the capacity of consumers (fish and crustaceans) to resist the impacts of elevated CO2. While individual behaviours were impaired by elevated CO2, consumers could restore their performances in more complex environments that allowed for compensatory processes. Consequently, consumers maintained key traits such as foraging, habitat selection and predator avoidance despite elevated CO2 and sustained their populations. Our observed increase in risk-taking under elevated temperature, however, predicts greater vulnerability of consumers to predation. Yet, CO2 as a resource boosted the biomass of consumers through species interactions and may stabilize communities by countering the negative effects of elevated temperature. We conclude that compensatory dynamics inherent in the complexity of nature can buffer the impacts of future climate on species and their communities.

Single-stranded nucleic acids promote SAMHD1 complex formation.

Science.gov (United States)

Tüngler, Victoria; Staroske, Wolfgang; Kind, Barbara; Dobrick, Manuela; Kretschmer, Stefanie; Schmidt, Franziska; Krug, Claudia; Lorenz, Mike; Chara, Osvaldo; Schwille, Petra; Lee-Kirsch, Min Ae

2013-06-01

SAM domain and HD domain-containing protein 1 (SAMHD1) is a dGTP-dependent triphosphohydrolase that degrades deoxyribonucleoside triphosphates (dNTPs) thereby limiting the intracellular dNTP pool. Mutations in SAMHD1 cause Aicardi-Goutières syndrome (AGS), an inflammatory encephalopathy that mimics congenital viral infection and that phenotypically overlaps with the autoimmune disease systemic lupus erythematosus. Both disorders are characterized by activation of the antiviral cytokine interferon-α initiated by immune recognition of self nucleic acids. Here we provide first direct evidence that SAMHD1 associates with endogenous nucleic acids in situ. Using fluorescence cross-correlation spectroscopy, we demonstrate that SAMHD1 specifically interacts with ssRNA and ssDNA and establish that nucleic acid-binding and formation of SAMHD1 complexes are mutually dependent. Interaction with nucleic acids and complex formation do not require the SAM domain, but are dependent on the HD domain and the C-terminal region of SAMHD1. We finally demonstrate that mutations associated with AGS exhibit both impaired nucleic acid-binding and complex formation implicating that interaction with nucleic acids is an integral aspect of SAMHD1 function.

A large-eddy simulation based power estimation capability for wind farms over complex terrain

Science.gov (United States)

Senocak, I.; Sandusky, M.; Deleon, R.

2017-12-01

There has been an increasing interest in predicting wind fields over complex terrain at the micro-scale for resource assessment, turbine siting, and power forecasting. These capabilities are made possible by advancements in computational speed from a new generation of computing hardware, numerical methods and physics modelling. The micro-scale wind prediction model presented in this work is based on the large-eddy simulation paradigm with surface-stress parameterization. The complex terrain is represented using an immersed-boundary method that takes into account the parameterization of the surface stresses. Governing equations of incompressible fluid flow are solved using a projection method with second-order accurate schemes in space and time. We use actuator disk models with rotation to simulate the influence of turbines on the wind field. Data regarding power production from individual turbines are mostly restricted because of proprietary nature of the wind energy business. Most studies report percentage drop of power relative to power from the first row. There have been different approaches to predict power production. Some studies simply report available wind power in the upstream, some studies estimate power production using power curves available from turbine manufacturers, and some studies estimate power as torque multiplied by rotational speed. In the present work, we propose a black-box approach that considers a control volume around a turbine and estimate the power extracted from the turbine based on the conservation of energy principle. We applied our wind power prediction capability to wind farms over flat terrain such as the wind farm over Mower County, Minnesota and the Horns Rev offshore wind farm in Denmark. The results from these simulations are in good agreement with published data. We also estimate power production from a hypothetical wind farm in complex terrain region and identify potential zones suitable for wind power production.

Large Neighborhood Search

DEFF Research Database (Denmark)

Pisinger, David; Røpke, Stefan

2010-01-01

Heuristics based on large neighborhood search have recently shown outstanding results in solving various transportation and scheduling problems. Large neighborhood search methods explore a complex neighborhood by use of heuristics. Using large neighborhoods makes it possible to find better...... candidate solutions in each iteration and hence traverse a more promising search path. Starting from the large neighborhood search method,we give an overview of very large scale neighborhood search methods and discuss recent variants and extensions like variable depth search and adaptive large neighborhood...

PeptideNavigator: An interactive tool for exploring large and complex data sets generated during peptide-based drug design projects.

Science.gov (United States)

Diller, Kyle I; Bayden, Alexander S; Audie, Joseph; Diller, David J

2018-01-01

There is growing interest in peptide-based drug design and discovery. Due to their relatively large size, polymeric nature, and chemical complexity, the design of peptide-based drugs presents an interesting "big data" challenge. Here, we describe an interactive computational environment, PeptideNavigator, for naturally exploring the tremendous amount of information generated during a peptide drug design project. The purpose of PeptideNavigator is the presentation of large and complex experimental and computational data sets, particularly 3D data, so as to enable multidisciplinary scientists to make optimal decisions during a peptide drug discovery project. PeptideNavigator provides users with numerous viewing options, such as scatter plots, sequence views, and sequence frequency diagrams. These views allow for the collective visualization and exploration of many peptides and their properties, ultimately enabling the user to focus on a small number of peptides of interest. To drill down into the details of individual peptides, PeptideNavigator provides users with a Ramachandran plot viewer and a fully featured 3D visualization tool. Each view is linked, allowing the user to seamlessly navigate from collective views of large peptide data sets to the details of individual peptides with promising property profiles. Two case studies, based on MHC-1A activating peptides and MDM2 scaffold design, are presented to demonstrate the utility of PeptideNavigator in the context of disparate peptide-design projects. Copyright © 2017 Elsevier Ltd. All rights reserved.

Development of the mechanical engineering complex on the basis of the improvement of large and small businesses relations

Directory of Open Access Journals (Sweden)

Sokolova Svetlana

2017-01-01

Full Text Available Condition, pace and character of the development of the mechanical engineering complex is in many aspects a crucial factor for the social and economic situation of any country. The development of market relations, changes of the conditions of doing business encourage the enterprises to search new managerial methods and to improve the interaction forms. In this respect the display of the peculiarities of the interaction of large machine engineering enterprises and small business in this sphere and also the assessment of the relationship of their development is an important and crucial issue under modern conditions. The most widely spread forms of the cooperation of large scale mechanical engineering enterprises and small businesses of the industry are: outsourcing, franchising, leasing, subcontracting, venture financing, creation of regional forms of the cooperation of large and small firms. However cooperation processes of large scale and small entrepreneurship in Russia are not properly developed. The authors determine the factors hindering the growth of the machine building industry, suggest the recommendations for the development of the large scale enterprises and small business in the industry, substantiate the role of the government in this process. Besides the mechanism of the state support of the development of small business is described.

THE GOULD's BELT VERY LARGE ARRAY SURVEY. I. THE OPHIUCHUS COMPLEX

Energy Technology Data Exchange (ETDEWEB)

Dzib, Sergio A.; Loinard, Laurent; Rodríguez, Luis F.; Ortiz-León, Gisela N.; Pech, Gerardo; Rivera, Juana L. [Centro de Radioastronomía y Astrofísica, Universidad Nacional Autónoma de México Apartado Postal 3-72, 58090 Morelia, Michoacán (Mexico); Mioduszewski, Amy J. [National Radio Astronomy Observatory, Domenici Science Operations Center, 1003 Lopezville Road, Socorro, NM 87801 (United States); Torres, Rosa M. [Paul Harris 9065, Las Condes, Santiago (Chile); Boden, Andrew F. [Division of Physics, Math, and Astronomy, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Hartmann, Lee [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48105 (United States); Evans, Neal J. II [Department of Astronomy, The University of Texas at Austin, 1 University Station, C1400, Austin, TX 78712 (United States); Briceño, Cesar [Centro de Investigaciones de Astronomía, Mérida 5101-A (Venezuela, Bolivarian Republic of); Tobin, John, E-mail: s.dzib@crya.unam.mx [National Radio Astronomy Observatory, Charlottesville, VA 22903 (United States)

2013-09-20

We present large-scale (∼2000 arcmin{sup 2}), deep (∼20 μJy), high-resolution (∼1'') radio observations of the Ophiuchus star-forming complex obtained with the Karl G. Jansky Very Large Array at λ = 4 and 6 cm. In total, 189 sources were detected, 56 of them associated with known young stellar sources, and 4 with known extragalactic objects; the other 129 remain unclassified, but most of them are most probably background quasars. The vast majority of the young stars detected at radio wavelengths have spectral types K or M, although we also detect four objects of A/F/B types and two brown dwarf candidates. At least half of these young stars are non-thermal (gyrosynchrotron) sources, with active coronas characterized by high levels of variability, negative spectral indices, and (in some cases) significant circular polarization. As expected, there is a clear tendency for the fraction of non-thermal sources to increase from the younger (Class 0/I or flat spectrum) to the more evolved (Class III or weak line T Tauri) stars. The young stars detected both in X-rays and at radio wavelengths broadly follow a Güdel-Benz relation, but with a different normalization than the most radioactive types of stars. Finally, we detect a ∼70 mJy compact extragalactic source near the center of the Ophiuchus core, which should be used as gain calibrator for any future radio observations of this region.

Aryldiazo complexes. Syntheses and reactions of new complexes of osmium and ruthenium

International Nuclear Information System (INIS)

Haymore, B.L.; Ibers, J.A.

1975-01-01

Aryldiazo complexes, [M(CO) 2 (NNPh)(PPh 3 ) 2 ][PF 6 ](M = Os, Ru; Ph = C 6 H 5 ), were prepared by allowing diazonium salts to react with M(CO) 3 (PPh 3 ) 2 . Infrared spectra of the Ru complex suggest the presence of two isomers both in solution and in the solid state. These complexes react with a variety of coordinating anions (X - ), to form MX(CO) 2 (NNPh)(PPh 3 ) 2 . The osmium derivatives have ν(NN) near 1455 cm -1 , which is the lowest value yet reported for a nonbridging aryldiazo ligand. The first aryldiazo--hydrido complexes, MH(CO) 2 (NNPh)(PPh 3 ) 2 and MH(CO)(NNPh)(PPh 3 ) 2 , were prepared by deprotonation of the respective phenyldiazene complexes, MH(CO) 2 (HNNPh)(PPh 3 ) 2 + and MH(CO)(HNNPh)(PPh 3 ) 3 + . The compound OsCl 3 (NNPh)(PPh 3 ) 2 was also prepared. A large number of the foregoing complexes were synthesized with selective 2 H and 15 N labels. Infrared and NMR spectra show MX(CO) 2 (NNPh)(PPh 3 ) 2 and the analogous hydrido complex to be pseudooctahedral with trans phosphine ligands, cis carbonyl ligands, and a doubly bent phenyldiazenido (NNPh - ) ligand. Similarly, MH(CO)(NNPh)(PPh 3 ) 2 possesses a trigonal-bipyramidal geometry with trans phosphine ligands and an equatorial, singly bent phenyldiazoniumato (NNPh + ) ligand. Isotopic substitution of the diazo ligand shows that ν(NN) is often vibrationally coupled with phenyl vibrational modes and that two or three bands sometimes shift upon 15 N substitution. Vibrational coupling was also observed in the higher energy region (1850 to 1900 cm -1 ) in the compound RuCl 3 (NNC 6 D 5 )(PPh 3 ) 2 . The wide range in the values of ν(NN), RuCl 3 (NNPh)(PPh 3 ) 2 (1882 cm -1 ) vs. RuCl(CO) 2 (NNPh)(PPh 3 ) 2 (1462 cm -1 ), indicates that the N--N stretching frequencies are sensitive to the electronic and steric environment of the diazo ligand. The aryldiazo complexes are compared with analogous, isoelectronic nitrosyl complexes of Os and Ru

Fe-Ti-O based catalyst for large-chiral-angle single-walled carbon nanotube growth

DEFF Research Database (Denmark)

He, Maoshuai; Zhang, Lili; Jiang, Hua

2016-01-01

Catalyst selection is very crucial for controlled growth of single-walled carbon nanotubes (SWNTs). Here we introduce a well-designed Fe-Ti-O solid solution for SWNT growth with a high preference to large chiral angles. The Fe-Ti-O catalyst was prepared by combining Ti layer deposition onto premade...... Fe nanoparticles with subsequent high-temperature air calcination, which favours the formation of a homogeneous Fe-Ti-O solid solution. Using CO as the carbon feedstock, chemical vapour deposition growth of SWNTs at 800 °C was demonstrated on the Fe-Ti-O catalyst. Nanobeam electron diffraction...... characterization on a number of individual SWNTs revealed that more than 94% of SWNTs have chiral angles larger than 15°. In situ environmental transmission electron microscopy study was carried out to reveal the catalyst dynamics upon reduction. Our results identify that the phase segregation through reducing Fe...

Crystallization and preliminary crystallographic studies of the single-chain variable fragment of antibody chA21 in complex with an N-terminal fragment of ErbB2

International Nuclear Information System (INIS)

Liu, Yang; Zhou, Huihao; Zhu, Juanjuan; Gao, Yongxiang; Niu, Liwen; Liu, Jing; Teng, Maikun

2009-01-01

An antibody–antigen complex consisting of a single-chain variable fragment of the potential therapeutic antibody chA21 and an N-terminal fragment (residues 1–192) of the human ErbB2 extracellular domain was expressed, purified and crystallized. X-ray diffraction data were collected to 2.45 Å resolution. ErbB2 is a transmembrane tyrosine kinase, the overexpression of which causes abnormality and disorder in cell signalling and leads to cell transformation. Previously, an anti-ErbB2 single-chain chimeric antibody chA21 that specifically inhibits the growth of ErbB2-overexpressing cancer cells in vitro and in vivo was developed. Here, an antibody–antigen complex consisting of the single-chain variable fragment (scFv) of chA21 and an N-terminal fragment (residues 1–192, named EP I) of the ErbB2 extracellular domain was crystallized using the sitting-drop vapour-diffusion method. An X-ray diffraction data set was collected to 2.45 Å resolution from a single flash-cooled crystal; the crystal belonged to space group P2 1 2 1 2 1

Pathological mechanisms underlying single large‐scale mitochondrial DNA deletions

Science.gov (United States)

Rocha, Mariana C.; Rosa, Hannah S.; Grady, John P.; Blakely, Emma L.; He, Langping; Romain, Nadine; Haller, Ronald G.; Newman, Jane; McFarland, Robert; Ng, Yi Shiau; Gorman, Grainne S.; Schaefer, Andrew M.; Tuppen, Helen A.; Taylor, Robert W.

2018-01-01

Objective Single, large‐scale deletions in mitochondrial DNA (mtDNA) are a common cause of mitochondrial disease. This study aimed to investigate the relationship between the genetic defect and molecular phenotype to improve understanding of pathogenic mechanisms associated with single, large‐scale mtDNA deletions in skeletal muscle. Methods We investigated 23 muscle biopsies taken from adult patients (6 males/17 females with a mean age of 43 years) with characterized single, large‐scale mtDNA deletions. Mitochondrial respiratory chain deficiency in skeletal muscle biopsies was quantified by immunoreactivity levels for complex I and complex IV proteins. Single muscle fibers with varying degrees of deficiency were selected from 6 patient biopsies for determination of mtDNA deletion level and copy number by quantitative polymerase chain reaction. Results We have defined 3 “classes” of single, large‐scale deletion with distinct patterns of mitochondrial deficiency, determined by the size and location of the deletion. Single fiber analyses showed that fibers with greater respiratory chain deficiency harbored higher levels of mtDNA deletion with an increase in total mtDNA copy number. For the first time, we have demonstrated that threshold levels for complex I and complex IV deficiency differ based on deletion class. Interpretation Combining genetic and immunofluorescent assays, we conclude that thresholds for complex I and complex IV deficiency are modulated by the deletion of complex‐specific protein‐encoding genes. Furthermore, removal of mt‐tRNA genes impacts specific complexes only at high deletion levels, when complex‐specific protein‐encoding genes remain. These novel findings provide valuable insight into the pathogenic mechanisms associated with these mutations. Ann Neurol 2018;83:115–130 PMID:29283441

Thermodynamics of complex structures formed between single-stranded DNA oligomers and the KH domains of the far upstream element binding protein

Energy Technology Data Exchange (ETDEWEB)

Chakraborty, Kaushik; Sinha, Sudipta Kumar; Bandyopadhyay, Sanjoy, E-mail: sanjoy@chem.iitkgp.ernet.in [Molecular Modeling Laboratory, Department of Chemistry, Indian Institute of Technology, Kharagpur 721302 (India)

2016-05-28

The noncovalent interaction between protein and DNA is responsible for regulating the genetic activities in living organisms. The most critical issue in this problem is to understand the underlying driving force for the formation and stability of the complex. To address this issue, we have performed atomistic molecular dynamics simulations of two DNA binding K homology (KH) domains (KH3 and KH4) of the far upstream element binding protein (FBP) complexed with two single-stranded DNA (ss-DNA) oligomers in aqueous media. Attempts have been made to calculate the individual components of the net entropy change for the complexation process by adopting suitable statistical mechanical approaches. Our calculations reveal that translational, rotational, and configurational entropy changes of the protein and the DNA components have unfavourable contributions for this protein-DNA association process and such entropy lost is compensated by the entropy gained due to the release of hydration layer water molecules. The free energy change corresponding to the association process has also been calculated using the Free Energy Perturbation (FEP) method. The free energy gain associated with the KH4–DNA complex formation has been found to be noticeably higher than that involving the formation of the KH3–DNA complex.

Propensity of a single-walled carbon nanotube-peptide to mimic a KK10 peptide in an HLA-TCR complex

Science.gov (United States)

Feng, Mei; Bell, David R.; Zhou, Ruhong

2017-12-01

The application of nanotechnology to improve disease diagnosis, treatment, monitoring, and prevention is the goal of nanomedicine. We report here a theoretical study of a functionalized single-walled carbon nanotube (CNT) mimic binding to a human leukocyte antigen-T cell receptor (HLA-TCR) immune complex as a first attempt of a potential nanomedicine for human immunodeficiency virus (HIV) vaccine development. The carbon nanotube was coated with three arginine residues to imitate the HIV type 1 immunodominant viral peptide KK10 (gag 263-272: KRWIILGLNK), named CNT-peptide hereafter. Through molecular dynamics simulations, we explore the CNT-peptide and KK10 binding to an important HLA-TCR complex. Our results suggest that the CNT-peptide and KK10 bind comparably to the HLA-TCR complex, but the CNT-peptide forms stronger interactions with the TCR. Desorption simulations highlight the innate flexibility of KK10 over the CNT-peptide, resulting in a slightly higher desorption energy required for KK10 over the CNT-peptide. Our findings indicate that the designed CNT-peptide mimic has favorable propensity to activate TCR pathways and should be further explored to understand therapeutic potential.

Synthesis, characterization, single crystal X-ray determination, fluorescence and electrochemical studies of new dinuclear nickel(II) and oxovanadium(IV) complexes containing double Schiff base ligands

Science.gov (United States)

Shafaatian, Bita; Ozbakzaei, Zahra; Notash, Behrouz; Rezvani, S. Ahmad

2015-04-01

A series of new bimetallic complexes of nickel(II) and vanadium(IV) have been synthesized by the reaction of the new double bidentate Schiff base ligands with nickel acetate and vanadyl acetylacetonate in 1:1 M ratio. In nickel and also vanadyl complexes the ligands were coordinated to the metals via the imine N and enolic O atoms. The complexes have been found to possess 1:1 metals to ligands stoichiometry and the molar conductance data revealed that the metal complexes were non-electrolytes. The nickel and vanadyl complexes exhibited distorted square planar and square pyramidal coordination geometries, respectively. The emission spectra of the ligands and their complexes were studied in methanol. Electrochemical properties of the ligands and their metal complexes were also investigated in DMSO solvent at 150 mV s-1 scan rate. The ligands and metal complexes showed both quasi-reversible and irreversible processes at this scan rate. The Schiff bases and their complexes have been characterized by FT-IR, 1H NMR, UV/Vis spectroscopies, elemental analysis and conductometry. The crystal structure of the nickel complex has been determined by single crystal X-ray diffraction.

Anatrophic Nephrolithotomy in the Management of Large Staghorn Calculi - A Single Centre Experience.

Science.gov (United States)

Keshavamurthy, Ramaiah; Karthikeyan, Vilvapathy Senguttuvan; Mallya, Ashwin; Sreenivas, Jayaram; Nelivigi, Girish Gurubasappa; Kamath, Ananth Janarthan

2017-05-01

With advances in endourology, open stone surgery for staghorn calculi has markedly diminished. Anatrophic Nephrolithotomy (AN) is performed for complex staghorn stones which cannot be cleared by a reasonable number of Percutaneous Nephrolithotomy (PNL) attempts. To assess the indications and outcomes of AN in the modern era. Between April 2008 and July 2015, AN was done in 14 renal units in 13 patients. In this retrospective study, demography, stone characteristics, operative details, clearance and long term outcomes were assessed. AN was performed for complex staghorn calculi involving pelvis and all calyces in 10 patients, infundibular stenosis in two patients and failed PNL in one patient. Mean (SD) in situ cold ischemia time was 47.64 (5.27) minutes. Retroperitoneal drain and double J stent were placed in all 13 patients. Median (IQR) estimated blood loss was 130 (75) ml. There was no perioperative mortality. Surgical site infection was seen in 2 patients and urosepsis in 2 patients. Drain was removed at a mean (SD) of 9.11 (6.15) days. Mean (SD) postoperative length of hospitalization was 15.44 (7.14) days. Stent removal was done in all patients between 2-8 weeks. Median (IQR) clearance was 95 (7.5%). There was no renal failure or new calculi during the follow up period {median (IQR): 1(3) years}. AN is effective in management of large staghorn calculi failed minimally invasive approaches and achieves 80%-100% clearance without much need for secondary interventions. Renal function is preserved and with emergence of laparoscopy and robotics, postoperative stay is minimized with expedited recovery and comparable results with open surgery.

An integrated native mass spectrometry and top-down proteomics method that connects sequence to structure and function of macromolecular complexes

Science.gov (United States)

Li, Huilin; Nguyen, Hong Hanh; Ogorzalek Loo, Rachel R.; Campuzano, Iain D. G.; Loo, Joseph A.

2018-02-01

Mass spectrometry (MS) has become a crucial technique for the analysis of protein complexes. Native MS has traditionally examined protein subunit arrangements, while proteomics MS has focused on sequence identification. These two techniques are usually performed separately without taking advantage of the synergies between them. Here we describe the development of an integrated native MS and top-down proteomics method using Fourier-transform ion cyclotron resonance (FTICR) to analyse macromolecular protein complexes in a single experiment. We address previous concerns of employing FTICR MS to measure large macromolecular complexes by demonstrating the detection of complexes up to 1.8 MDa, and we demonstrate the efficacy of this technique for direct acquirement of sequence to higher-order structural information with several large complexes. We then summarize the unique functionalities of different activation/dissociation techniques. The platform expands the ability of MS to integrate proteomics and structural biology to provide insights into protein structure, function and regulation.

The PREP Pipeline: Standardized preprocessing for large-scale EEG analysis

Directory of Open Access Journals (Sweden)

Nima eBigdelys Shamlo

2015-06-01

Full Text Available The technology to collect brain imaging and physiological measures has become portable and ubiquitous, opening the possibility of large-scale analysis of real-world human imaging. By its nature, such data is large and complex, making automated processing essential. This paper shows how lack of attention to the very early stages of an EEG preprocessing pipeline can reduce the signal-to-noise ratio and introduce unwanted artifacts into the data, particularly for computations done in single precision. We demonstrate that ordinary average referencing improves the signal-to-noise ratio, but that noisy channels can contaminate the results. We also show that identification of noisy channels depends on the reference and examine the complex interaction of filtering, noisy channel identification, and referencing. We introduce a multi-stage robust referencing scheme to deal with the noisy channel-reference interaction. We propose a standardized early-stage EEG processing pipeline (PREP and discuss the application of the pipeline to more than 600 EEG datasets. The pipeline includes an automatically generated report for each dataset processed. Users can download the PREP pipeline as a freely available MATLAB library from http://eegstudy.org/prepcode/.

The PREP pipeline: standardized preprocessing for large-scale EEG analysis.

Science.gov (United States)

Bigdely-Shamlo, Nima; Mullen, Tim; Kothe, Christian; Su, Kyung-Min; Robbins, Kay A

2015-01-01

The technology to collect brain imaging and physiological measures has become portable and ubiquitous, opening the possibility of large-scale analysis of real-world human imaging. By its nature, such data is large and complex, making automated processing essential. This paper shows how lack of attention to the very early stages of an EEG preprocessing pipeline can reduce the signal-to-noise ratio and introduce unwanted artifacts into the data, particularly for computations done in single precision. We demonstrate that ordinary average referencing improves the signal-to-noise ratio, but that noisy channels can contaminate the results. We also show that identification of noisy channels depends on the reference and examine the complex interaction of filtering, noisy channel identification, and referencing. We introduce a multi-stage robust referencing scheme to deal with the noisy channel-reference interaction. We propose a standardized early-stage EEG processing pipeline (PREP) and discuss the application of the pipeline to more than 600 EEG datasets. The pipeline includes an automatically generated report for each dataset processed. Users can download the PREP pipeline as a freely available MATLAB library from http://eegstudy.org/prepcode.

How to Commission, Operate and Maintain a Large Future Accelerator Complex From Far Remote Sites

International Nuclear Information System (INIS)

Phinney, Nan

2001-01-01

A study on future large accelerators [1] has considered a facility, which is designed, built and operated by a worldwide collaboration of equal partner institutions, and which is remote from most of these institutions. The full range of operation was considered including commissioning, machine development, maintenance, trouble shooting and repair. Experience from existing accelerators confirms that most of these activities are already performed remotely. The large high-energy physics experiments and astronomy projects, already involve international collaborations of distant institutions. Based on this experience, the prospects for a machine operated remotely from far sites are encouraging. Experts from each laboratory would remain at their home institution but continue to participate in the operation of the machine after construction. Experts are required to be on site only during initial commissioning and for particularly difficult problems. Repairs require an on-site non-expert maintenance crew. Most of the interventions can be made without an expert and many of the rest resolved with remote assistance. There appears to be no technical obstacle to controlling an accelerator from a distance. The major challenge is to solve the complex management and communication problems

How to Commission, Operate and Maintain a Large Future Accelerator Complex From Far Remote Sites

Energy Technology Data Exchange (ETDEWEB)

Phinney, Nan

2001-12-07

A study on future large accelerators [1] has considered a facility, which is designed, built and operated by a worldwide collaboration of equal partner institutions, and which is remote from most of these institutions. The full range of operation was considered including commissioning, machine development, maintenance, troubleshooting and repair. Experience from existing accelerators confirms that most of these activities are already performed 'remotely'. The large high-energy physics experiments and astronomy projects, already involve international collaborations of distant institutions. Based on this experience, the prospects for a machine operated remotely from far sites are encouraging. Experts from each laboratory would remain at their home institution but continue to participate in the operation of the machine after construction. Experts are required to be on site only during initial commissioning and for particularly difficult problems. Repairs require an on-site non-expert maintenance crew. Most of the interventions can be made without an expert and many of the rest resolved with remote assistance. There appears to be no technical obstacle to controlling an accelerator from a distance. The major challenge is to solve the complex management and communication problems.

Effects of artificial holes in very large single-grain Y{sub 1.5}Ba{sub 2}Cu{sub 3}O{sub 7-y} bulk superconductors

Energy Technology Data Exchange (ETDEWEB)

Park, S. D.; Jun, B. H.; Kim, C. J. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Park, H. W. [Korea University of Technology and Education, Cheonan (Korea, Republic of)

2017-09-15

The effects of artificial holes on the trapped magnetic fields and magnetic levitation forces of very large single-grain Y{sub 1.5}Ba{sub 2}Cu{sub 3}O{sub 7-y} (Y1.5) bulk superconductors were studied. Artificial holes were made for Y1.5 powder compacts by die pressing using cylindrical dies with a diameter of 30 mm or 40 m, or rectangular dies with a side length of 50 mm. The single grain Y1.5 bulk superconductors (25 mm, 33 mm in diameter and 42 mm in side length) with artificial holes were fabricated using a top-seeded melt growth (TSMG) process for the die-pressed Y1.5 powder compacts. The magnetic levitation forces at 77 K of the 25 mm single grain Y1.5 samples with one (diameters of 4.2 mm) or six artificial holes (diameters of 2.5 mm) were 10-17% higher than that of the Y1.5 sample without artificial holes. The trapped magnetic fields at 77 K of the Y1.5 samples with artificial holes were also 9.6-18% higher than that of the Y1.5 sample without artificial holes. The 33 mm and 42 mm single grain Y1.5 samples with artificial holes (2.5 mm and 4.2 mm in diameter) also showed trapped magnetic fields 10-13% higher than that of the Y1.5 samples without artificial holes in spite of the reduced superconducting volume fraction due to the presence of artificial holes. The property enhancement in the large single grain Y1.5 bulk superconductors appears to be attributed to the formation of the pore-free regions near the artificial holes and the homogeneous oxygen distribution in the large Y123 grains.

Crystallization process of a three-dimensional complex plasma

Science.gov (United States)

Steinmüller, Benjamin; Dietz, Christopher; Kretschmer, Michael; Thoma, Markus H.

2018-05-01

Characteristic timescales and length scales for phase transitions of real materials are in ranges where a direct visualization is unfeasible. Therefore, model systems can be useful. Here, the crystallization process of a three-dimensional complex plasma under gravity conditions is considered where the system ranges up to a large extent into the bulk plasma. Time-resolved measurements exhibit the process down to a single-particle level. Primary clusters, consisting of particles in the solid state, grow vertically and, secondarily, horizontally. The box-counting method shows a fractal dimension of df≈2.72 for the clusters. This value gives a hint that the formation process is a combination of local epitaxial and diffusion-limited growth. The particle density and the interparticle distance to the nearest neighbor remain constant within the clusters during crystallization. All results are in good agreement with former observations of a single-particle layer.

Optimal hypofractionated conformal radiotherapy for large brain metastases in patients with high risk factors: a single-institutional prospective study

International Nuclear Information System (INIS)

Inoue, Hiroshi K; Sato, Hiro; Suzuki, Yoshiyuki; Saitoh, Jun-ichi; Noda, Shin-ei; Seto, Ken-ichi; Torikai, Kota; Sakurai, Hideyuki; Nakano, Takashi

2014-01-01

A single-institutional prospective study of optimal hypofractionated conformal radiotherapy for large brain metastases with high risk factors was performed based on the risk prediction of radiation-related complications. Eighty-eight patients with large brain metastases ≥10 cm 3 in critical areas treated from January 2010 to February 2014 using the CyberKnife were evaluated. The optimal dose and number of fractions were determined based on the surrounding brain volume circumscribed with a single dose equivalent (SDE) of 14 Gy (V14) to be less than 7 cm 3 for individual lesions. Univariate and multivariate analyses were conducted. As a result of optimal treatment, 92 tumors ranging from 10 to 74.6 cm 3 (median, 16.2 cm 3 ) in volume were treated with a median prescribed isodose of 57% and a median fraction number of five. In order to compare the results according to the tumor volume, the tumors were divided into the following three groups: 1) 10–19.9 cm 3 , 2) 20–29.9 cm 3 and 3) ≥30 cm 3 . The lesions were treated with a median prescribed isodose of 57%, 56% and 55%, respectively, and the median fraction number was five in all three groups. However, all tumors ≥20 cm 3 were treated with ≥ five fractions. The median SDE of the maximum dose in the three groups was 47.2 Gy, 48.5 Gy and 46.5 Gy, respectively. Local tumor control was obtained in 90.2% of the patients, and the median survival was nine months, with a median follow-up period of seven months (range, 3-41 months). There were no significant differences in the survival rates among the three groups. Six tumors exhibited marginal recurrence 7-36 months after treatment. Ten patients developed symptomatic brain edema or recurrence of pre-existing edema, seven of whom required osmo-steroid therapy. No patients developed radiation necrosis requiring surgical resection. Our findings demonstrate that the administration of optimal hypofractionated conformal radiotherapy based on the dose-volume prediction

Complex Dynamic Development of Poliovirus Membranous Replication Complexes

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Nair, Vinod; Hansen, Bryan T.; Hoyt, Forrest H.; Fischer, Elizabeth R.; Ehrenfeld, Ellie

2012-01-01

Replication of all positive-strand RNA viruses is intimately associated with membranes. Here we utilize electron tomography and other methods to investigate the remodeling of membranes in poliovirus-infected cells. We found that the viral replication structures previously described as “vesicles” are in fact convoluted, branching chambers with complex and dynamic morphology. They are likely to originate from cis-Golgi membranes and are represented during the early stages of infection by single-walled connecting and branching tubular compartments. These early viral organelles gradually transform into double-membrane structures by extension of membranous walls and/or collapsing of the luminal cavity of the single-membrane structures. As the double-membrane regions develop, they enclose cytoplasmic material. At this stage, a continuous membranous structure may have double- and single-walled membrane morphology at adjacent cross-sections. In the late stages of the replication cycle, the structures are represented mostly by double-membrane vesicles. Viral replication proteins, double-stranded RNA species, and actively replicating RNA are associated with both double- and single-membrane structures. However, the exponential phase of viral RNA synthesis occurs when single-membrane formations are predominant in the cell. It has been shown previously that replication complexes of some other positive-strand RNA viruses form on membrane invaginations, which result from negative membrane curvature. Our data show that the remodeling of cellular membranes in poliovirus-infected cells produces structures with positive curvature of membranes. Thus, it is likely that there is a fundamental divergence in the requirements for the supporting cellular membrane-shaping machinery among different groups of positive-strand RNA viruses. PMID:22072780

Response of single bacterial cells to stress gives rise to complex history dependence at the population level

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Mathis, Roland; Ackermann, Martin

2016-01-01

Most bacteria live in ever-changing environments where periods of stress are common. One fundamental question is whether individual bacterial cells have an increased tolerance to stress if they recently have been exposed to lower levels of the same stressor. To address this question, we worked with the bacterium Caulobacter crescentus and asked whether exposure to a moderate concentration of sodium chloride would affect survival during later exposure to a higher concentration. We found that the effects measured at the population level depended in a surprising and complex way on the time interval between the two exposure events: The effect of the first exposure on survival of the second exposure was positive for some time intervals but negative for others. We hypothesized that the complex pattern of history dependence at the population level was a consequence of the responses of individual cells to sodium chloride that we observed: (i) exposure to moderate concentrations of sodium chloride caused delays in cell division and led to cell-cycle synchronization, and (ii) whether a bacterium would survive subsequent exposure to higher concentrations was dependent on the cell-cycle state. Using computational modeling, we demonstrated that indeed the combination of these two effects could explain the complex patterns of history dependence observed at the population level. Our insight into how the behavior of single cells scales up to processes at the population level provides a perspective on how organisms operate in dynamic environments with fluctuating stress exposure. PMID:26960998

High-Accuracy Elevation Data at Large Scales from Airborne Single-Pass SAR Interferometry

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Guy Jean-Pierre Schumann

2016-01-01

Full Text Available Digital elevation models (DEMs are essential data sets for disaster risk management and humanitarian relief services as well as many environmental process models. At present, on the hand, globally available DEMs only meet the basic requirements and for many services and modeling studies are not of high enough spatial resolution and lack accuracy in the vertical. On the other hand, LiDAR-DEMs are of very high spatial resolution and great vertical accuracy but acquisition operations can be very costly for spatial scales larger than a couple of hundred square km and also have severe limitations in wetland areas and under cloudy and rainy conditions. The ideal situation would thus be to have a DEM technology that allows larger spatial coverage than LiDAR but without compromising resolution and vertical accuracy and still performing under some adverse weather conditions and at a reasonable cost. In this paper, we present a novel single pass In-SAR technology for airborne vehicles that is cost-effective and can generate DEMs with a vertical error of around 0.3 m for an average spatial resolution of 3 m. To demonstrate this capability, we compare a sample single-pass In-SAR Ka-band DEM of the California Central Valley from the NASA/JPL airborne GLISTIN-A to a high-resolution LiDAR DEM. We also perform a simple sensitivity analysis to floodplain inundation. Based on the findings of our analysis, we argue that this type of technology can and should be used to replace large regions of globally available lower resolution DEMs, particularly in coastal, delta and floodplain areas where a high number of assets, habitats and lives are at risk from natural disasters. We conclude with a discussion on requirements, advantages and caveats in terms of instrument and data processing.

Proposed method of producing large optical mirrors Single-point diamond crushing followed by polishing with a small-area tool

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Wright, G.; Bryan, J. B.

1986-01-01

Faster production of large optical mirrors may result from combining single-point diamond crushing of the glass with polishing using a small area tool to smooth the surface and remove the damaged layer. Diamond crushing allows a surface contour accurate to 0.5 microns to be generated, and the small area computer-controlled polishing tool allows the surface roughness to be removed without destroying the initial contour. Final contours with an accuracy of 0.04 microns have been achieved.

Descriptive Study of an Outbreak of Avian Urolithiasis in a Large Commercial Egg Complex in Algeria

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Hicham SID

2011-03-01

Full Text Available Avian urolithiasis is one of the major causes of mortality in poultry. However, in Algeria this condition has never been described. An outbreak of avian urolithiasis was observed on a large commercial egg complex in the department of Chlef (West of Algeria. The clinical features of this condition are to be described. Mortality associated to urolithiasis started at the onset of egg production, estimated to 0.7 % per week. Urolithiasis induced an egg drop estimated to 12%. Dead and live layers were both necropsied and examined for kidney lesions. Most of the birds examined presented enlarged ureters, renal atrophy and visceral gout deposition.

Continental pollution in the Western Mediterranean basin: large variability of the aerosol single scattering albedo and influence on the direct shortwave radiative effect

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C. Di Biagio

2016-08-01

Full Text Available Pollution aerosols strongly influence the composition of the Western Mediterranean basin, but at present little is known on their optical properties. We report in this study in situ observations of the single scattering albedo (ω of pollution aerosol plumes measured over the Western Mediterranean basin during the TRAQA (TRansport and Air QuAlity airborne campaign in summer 2012. Cases of pollution export from different source regions around the basin and at different altitudes between  ∼  160 and 3500 m above sea level were sampled during the flights. Data from this study show a large variability of ω, with values between 0.84–0.98 at 370 nm and 0.70–0.99 at 950 nm. The single scattering albedo generally decreases with the wavelength, with some exception associated to the mixing of pollution with sea spray or dust particles over the sea surface. The lowest values of ω (0.84–0.70 between 370 and 950 nm are measured in correspondence of a fresh plume possibly linked to ship emissions over the basin. The range of variability of ω observed in this study seems to be independent of the source region around the basin, as well as of the altitude and aging time of the plumes. The observed variability of ω reflects in a large variability for the complex refractive index of pollution aerosols, which is estimated to span in the large range 1.41–1.77 and 0.002–0.097 for the real and the imaginary parts, respectively, between 370 and 950 nm. Radiative calculations in clear-sky conditions were performed with the GAME radiative transfer model to test the sensitivity of the aerosol shortwave Direct Radiative Effect (DRE to the variability of ω as observed in this study. Results from the calculations suggest up to a 50 and 30 % change of the forcing efficiency (FE, i.e. the DRE per unit of optical depth, at the surface (−160/−235 W m−2 τ−1 at 60° solar zenith angle and at the Top-Of-Atmosphere (−137/−92�

Towards a Molecular Understanding of the Fanconi Anemia Core Complex

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Charlotte Hodson

2012-01-01

Full Text Available Fanconi Anemia (FA is a genetic disorder characterized by the inability of patient cells to repair DNA damage caused by interstrand crosslinking agents. There are currently 14 verified FA genes, where mutation of any single gene prevents repair of DNA interstrand crosslinks (ICLs. The accumulation of ICL damage results in genome instability and patients having a high predisposition to cancers. The key event of the FA pathway is dependent on an eight-protein core complex (CC, required for the monoubiquitination of each member of the FANCD2-FANCI complex. Interestingly, the majority of patient mutations reside in the CC. The molecular mechanisms underlying the requirement for such a large complex to carry out a monoubiquitination event remain a mystery. This paper documents the extensive efforts of researchers so far to understand the molecular roles of the CC proteins with regard to its main function in the FA pathway, the monoubiquitination of FANCD2 and FANCI.

Towards a Molecular Understanding of the Fanconi Anemia Core Complex

Science.gov (United States)

Hodson, Charlotte; Walden, Helen

2012-01-01

Fanconi Anemia (FA) is a genetic disorder characterized by the inability of patient cells to repair DNA damage caused by interstrand crosslinking agents. There are currently 14 verified FA genes, where mutation of any single gene prevents repair of DNA interstrand crosslinks (ICLs). The accumulation of ICL damage results in genome instability and patients having a high predisposition to cancers. The key event of the FA pathway is dependent on an eight-protein core complex (CC), required for the monoubiquitination of each member of the FANCD2-FANCI complex. Interestingly, the majority of patient mutations reside in the CC. The molecular mechanisms underlying the requirement for such a large complex to carry out a monoubiquitination event remain a mystery. This paper documents the extensive efforts of researchers so far to understand the molecular roles of the CC proteins with regard to its main function in the FA pathway, the monoubiquitination of FANCD2 and FANCI. PMID:22675617

Universal Poisson Statistics of mRNAs with Complex Decay Pathways.

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Thattai, Mukund

2016-01-19

Messenger RNA (mRNA) dynamics in single cells are often modeled as a memoryless birth-death process with a constant probability per unit time that an mRNA molecule is synthesized or degraded. This predicts a Poisson steady-state distribution of mRNA number, in close agreement with experiments. This is surprising, since mRNA decay is known to be a complex process. The paradox is resolved by realizing that the Poisson steady state generalizes to arbitrary mRNA lifetime distributions. A mapping between mRNA dynamics and queueing theory highlights an identifiability problem: a measured Poisson steady state is consistent with a large variety of microscopic models. Here, I provide a rigorous and intuitive explanation for the universality of the Poisson steady state. I show that the mRNA birth-death process and its complex decay variants all take the form of the familiar Poisson law of rare events, under a nonlinear rescaling of time. As a corollary, not only steady-states but also transients are Poisson distributed. Deviations from the Poisson form occur only under two conditions, promoter fluctuations leading to transcriptional bursts or nonindependent degradation of mRNA molecules. These results place severe limits on the power of single-cell experiments to probe microscopic mechanisms, and they highlight the need for single-molecule measurements. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

High-resolution AFM topographs of Rubrivivax gelatinosus light-harvesting complex LH2

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Scheuring, Simon; Reiss-Husson, Francoise; Engel, Andreas; Rigaud, Jean-Louis; Ranck, Jean-Luc

2001-01-01

Light-harvesting complexes 2 (LH2) are the accessory antenna proteins in the bacterial photosynthetic apparatus and are built up of αβ-heterodimers containing three bacteriochlorophylls and one carotenoid each. We have used atomic force microscopy (AFM) to investigate reconstituted LH2 from Rubrivivax gelatinosus, which has a C-terminal hydrophobic extension of 21 amino acids on the α-subunit. High-resolution topographs revealed a nonameric organization of the regularly packed cylindrical complexes incorporated into the membrane in both orientations. Native LH2 showed one surface which protruded by ∼6 Å and one that protruded by ∼14 Å from the membrane. Topographs of samples reconstituted with thermolysin-digested LH2 revealed a height reduction of the strongly protruding surface to ∼9 Å, and a change of its surface appearance. These results suggested that the α-subunit of R.gelatinosus comprises a single transmembrane helix and an extrinsic C-terminus, and allowed the periplasmic surface to be assigned. Occasionally, large rings (∼120 Å diameter) surrounded by LH2 rings were observed. Their diameter and appearance suggest the large rings to be LH1 complexes. PMID:11406579

Fluid-structure interaction simulation of floating structures interacting with complex, large-scale ocean waves and atmospheric turbulence with application to floating offshore wind turbines

Science.gov (United States)

Calderer, Antoni; Guo, Xin; Shen, Lian; Sotiropoulos, Fotis

2018-02-01

We develop a numerical method for simulating coupled interactions of complex floating structures with large-scale ocean waves and atmospheric turbulence. We employ an efficient large-scale model to develop offshore wind and wave environmental conditions, which are then incorporated into a high resolution two-phase flow solver with fluid-structure interaction (FSI). The large-scale wind-wave interaction model is based on a two-fluid dynamically-coupled approach that employs a high-order spectral method for simulating the water motion and a viscous solver with undulatory boundaries for the air motion. The two-phase flow FSI solver is based on the level set method and is capable of simulating the coupled dynamic interaction of arbitrarily complex bodies with airflow and waves. The large-scale wave field solver is coupled with the near-field FSI solver with a one-way coupling approach by feeding into the latter waves via a pressure-forcing method combined with the level set method. We validate the model for both simple wave trains and three-dimensional directional waves and compare the results with experimental and theoretical solutions. Finally, we demonstrate the capabilities of the new computational framework by carrying out large-eddy simulation of a floating offshore wind turbine interacting with realistic ocean wind and waves.

Real-Time Observation of Target Search by the CRISPR Surveillance Complex Cascade

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Chaoyou Xue

2017-12-01

Full Text Available CRISPR-Cas systems defend bacteria and archaea against infection by bacteriophage and other threats. The central component of these systems are surveillance complexes that use guide RNAs to bind specific regions of foreign nucleic acids, marking them for destruction. Surveillance complexes must locate targets rapidly to ensure timely immune response, but the mechanism of this search process remains unclear. Here, we used single-molecule FRET to visualize how the type I-E surveillance complex Cascade searches DNA in real time. Cascade rapidly and randomly samples DNA through nonspecific electrostatic contacts, pausing at short PAM recognition sites that may be adjacent to the target. We identify Cascade motifs that are essential for either nonspecific sampling or positioning and readout of the PAM. Our findings provide a comprehensive structural and kinetic model for the Cascade target-search mechanism, revealing how CRISPR surveillance complexes can rapidly search large amounts of genetic material en route to target recognition.

Single-Phase PLLs

DEFF Research Database (Denmark)

Golestan, Saeed; Guerrero, Josep M.; Quintero, Juan Carlos Vasquez

2017-01-01

Single-phase phase-locked loops (PLLs) are popular for the synchronization and control of single-phase gridconnected converters. They are also widely used for monitoring and diagnostic purposes in the power and energy areas. In recent years, a large number of single-phase PLLs with different stru......-PLLs). The members of each category are then described and their pros and cons are discussed. This work provides a deep insight into characteristics of different single-phase PLLs and, therefore, can be considered as a reference for researchers and engineers....

Single-port (OctoPort) assisted extracorporeal ovarian cystectomy for the treatment of large ovarian cysts: compare to conventional laparoscopy and laparotomy.

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Chong, Gun Oh; Hong, Dae Gy; Lee, Yoon Soon

2015-01-01

To evaluate single-port assisted extracorporeal cystectomy for treatment of large ovarian cysts and to compare its surgical outcomes, complications, and cystic content spillage rates with those of conventional laparoscopy and laparotomy. Retrospective study (Canadian Task Force classification II-2). University teaching hospital. Twenty-five patients who underwent single-port assisted extracorporeal cystectomy (group 1), 33 patients who underwent conventional laparoscopy (group 2), and 25 patients who underwent laparotomy (group 3). Surgical outcomes, complications, and spillage rates in group 1 were compared with those in groups 2 and 3. Patients characteristics and tumor histologic findings were similar in the 3 groups. The mean (SD) largest diameter of ovarian cysts was 11.4 (4.2) cm in group 1, 9.7 (2.3) cm in group 2, and 12.0 (3.4) cm in group 3. Operative time in groups 1 and 2 was similar at 69.3 (26.3) minutes vs 73.1 (36.3) minutes (p = .66); however, operative time in group 1 was shorter than in group 3, at 69.3 (26.3) minutes vs 87.5 (26.6) minutes (p =.02). Blood loss in group 1 was significantly lower than in groups 2 and 3, at 16.0 (19.4) mL vs 36.1 (20.7) mL (p < .001) and 16.0 (19.4) mL vs 42.2 (39.7) mL (p = .005). The spillage rate in group 1 was profoundly lower than in group 2, at 8.0% vs 69.7% (p < .001). Single-port assisted extracorporeal cystectomy offers an alternative to conventional laparoscopy and laparotomy for management of large ovarian cysts, with comparable surgical outcomes. Furthermore, cyst content spillage rate in single-port assisted extracorporeal cystectomy was remarkably lower than that in conventional laparoscopy. Copyright © 2015. Published by Elsevier Inc.

Large-Scale Synthesis of Single-Crystalline Iron Oxide Magnetic Nanorings

DEFF Research Database (Denmark)

Jia, Chun-Jiang; Sun, Ling-Dong; Luo, Feng

2008-01-01

We present an innovative approach to the production of single-crystal iron oxide nanorings employing a solution-based route. Single-crystal hematite (alpha-Fe2O3) nanorings were synthesized using a double anion-assisted hydrothermal method (involving phosphate and sulfate ions), which can...... an intriguing three-dimensional magnetic configuration. This work provides an easily scaled-up method for preparing tailor-made iron oxide nanorings that could meet the demands of a variety of applications ranging from medicine to magnetoelectronics....... able to control the size, morphology, and surface architecture to produce a variety of three-dimensional hollow nanostructures. These can then be converted to magnetite (Fe3O4) and maghemite (gamma-Fe2O3) by a reduction or reduction-oxidation process while preserving the same morphology. The structures...

Management of a Large Qualitative Data Set: Establishing Trustworthiness of the Data

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Debbie Elizabeth White RN, PhD

2012-07-01

Full Text Available Health services research is multifaceted and impacted by the multiple contexts and stakeholders involved. Hence, large data sets are necessary to fully understand the complex phenomena (e.g., scope of nursing practice being studied. The management of these large data sets can lead to numerous challenges in establishing trustworthiness of the study. This article reports on strategies utilized in data collection and analysis of a large qualitative study to establish trustworthiness. Specific strategies undertaken by the research team included training of interviewers and coders, variation in participant recruitment, consistency in data collection, completion of data cleaning, development of a conceptual framework for analysis, consistency in coding through regular communication and meetings between coders and key research team members, use of N6™ software to organize data, and creation of a comprehensive audit trail with internal and external audits. Finally, we make eight recommendations that will help ensure rigour for studies with large qualitative data sets: organization of the study by a single person; thorough documentation of the data collection and analysis process; attention to timelines; the use of an iterative process for data collection and analysis; internal and external audits; regular communication among the research team; adequate resources for timely completion; and time for reflection and diversion. Following these steps will enable researchers to complete a rigorous, qualitative research study when faced with large data sets to answer complex health services research questions.

Research on the Governance Mechanism of Aviation Complex Product Manufacturing Supply Chain Based on Dynamic Game Theory

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Wang Nan

2016-01-01

Full Text Available In the manufacturing process of aeronautical complex products, for the following problems: develop long production cycle, a large number of ancillary products, a plurality of participating units, etc, and the status of the frequency of quality problems, using single-phase static game model in the case of asymmetric information, study on Supplier Quality insufficient investment, which resulting in opportunistic behaviour reasons. And using KMRW dynamic game model, we quantitative analysis the mechanism and crucial role of reputation mechanisms to ensure aeronautical complex product manufacturing supply chain and effective operation.

Large Stroke High Fidelity PZN-PT Single-Crystal "Stake" Actuator.

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Huang, Yu; Xia, Yuexue; Lin, Dian Hua; Yao, Kui; Lim, Leong Chew

2017-10-01

A new piezoelectric actuator design, called "Stake" actuator, is proposed and demonstrated in this paper. As an example, the stake actuator is made of four d 32 -mode PZN-5.5%PT single crystals (SCs), each of 25 mm ( L ) ×8 mm ( W ) ×0.4 mm (T) in dimensions, bonded with the aid of polycarbonate edge guide-cum-stiffeners into a square-pipe configuration for improved bending and twisting strengths and capped with top and bottom pedestals made of 1.5-mm-thick anodized aluminum. The resultant stake actuator measured 9 mm ×9 mm ×28 mm. The hollow structure is a key design feature, which optimizes SC usage efficiency and lowers the overall cost of the actuator. The displacement-voltage responses, blocking forces, resonance characteristics of the fabricated stake actuator, as well as the load and temperature effects, are measured and discussed. Since d 32 is negative for [011]-poled SC, the "Stake" actuator contracts in the axial direction when a positive-polarity field is applied to the crystals. Biased drive is thus recommended when extensional displacement is desired. The SC stake actuator has negligible (0.13% when driven up to +300 V (i.e., 0.75 kV/mm), which is close to the rhombohedral-to-orthorhombic transformation field ( E RO ) of 0.85 kV/mm of the SC used. The stake actuator displays a stroke of [Formula: see text] (at +300 V) despite its small overall dimensions, and has a blocking force of 114 N. The SC d 32 stake actuator fabricated displays more than 30% larger axial strain than the state-of-the-art PZT stack actuators of comparable length as well as moderate blocking forces. Said actuators are thus ideal for applications when large displacements with simple open-loop control are preferred.

Examining Food Risk in the Large using a Complex, Networked System-of-sytems Approach