[Postextubation laryngeal edema seven years after undergoing neck dissection].

PubMed

Daijo, Hiroki; Habara, Toshie; Katagawa, Tomoko; Yoshikawa, Yukiko; Shinomura, Tetsutaro

2008-05-01

We report a case of upper airway obstruction after extubation in a 69-year-old female patient who underwent transurethral ureterolithotripsy (TUL). She had underwent bilateral modified radical neck dissection 7 years previously. TUL went smoothly in Trenderenburg position, and the extubation was performed after antagonism of neuromuscular block. The patient was closely observed in the operating theater, but about 10 minutes after extubation, she was noted to have dyspnea and tracheal tug. Dexamathasone 2 mg IV was given but was unsuccessful. Although we could support the airway with bag-mask ventilation, continuous stridor required re-intubation. Direct laryngoscopy revealed severe obstruction caused by laryngeal edema. An otolaryngologist was consulted and he performed tracheostomy. We transferred the patient to the intensive care unit for observation. Flexible fiberoptic scope examination performed on postoperative day (POD) 1 showed the decrease of the laryngeal edema. Tacheal tube was removed on POD 7 and she was discharged from the hospital POD 10 without further complications. Patients after a neck dissection may be at elevated risk for postoperative laryngeal edema caused by lymphatic destruction or venous congestion of the neck.

U.S. EPA, Pesticide Product Label, TOMBSTONE, 07/31/2006

EPA Pesticide Factsheets

2011-04-21

... ('If ,Ille8b1 onr:., rIQhHlI19:,-1 turr' In rna:l! stream 1',:;. t,U::!l Urcl\\ UlOfOugt) m»IY,l ~~,t ... IO "". 1lf"')'r]"'C'!',,j rll.' l\\rll!tJ\\',<~lu' CI:Ji I',"" ' t,';-ttC-:II'l'I'!" I:f ...

Total angular momenta of high-lying odd levels of U I at ∼ 4 eV using resonance ionization laser polarization spectroscopy

NASA Astrophysics Data System (ADS)

Rath, Asawari D.; Kundu, S.; Ray, A. K.

2018-02-01

Laser induced photoionization of atoms shows significant dependence on the choice of polarizations of lasers. In multi-step, multi-photon excitation and subsequent ionization of atoms different polarization combinations of the exciting lasers lead to distinctly different ion yields. This fact is exploited in this work to determine total angular momenta of odd-parity energy levels of U I lying at ∼ 4 eV from its ground level using resonance ionization laser polarization spectroscopy in time of flight mass spectrometer. These levels are populated by two-step resonant excitation using two pulsed dye lasers with preset polarizations of choice followed by nonresonant ionization by third laser. The dependence of ionization yield on specific polarizations of the first two lasers is studied experimentally for each level under consideration. This dependence when compared to simulations makes possible unambiguous assignment of J angular momenta to these levels.

Expression of metastasis suppressor BRMS1 in breast cancer cells results in a marked delay in cellular adhesion to matrix

USDA-ARS?s Scientific Manuscript database

Metastatic dissemination is a multi-step process that depends on cancer cells’ ability to respond to microenvironmental cues by adapting adhesion abilities and undergoing cytoskeletal rearrangement. Breast Cancer Metastasis Suppressor 1 (BRMS1) affects several steps of the metastatic cascade: it dec...

Microbial shifts in the swine nasal microbiota in response to parenteral antimicrobial administration.

PubMed

Zeineldin, Mohamed; Aldridge, Brian; Blair, Benjamin; Kancer, Katherine; Lowe, James

2018-05-24

The continuous administration of antimicrobials in swine production has been widely criticized with the increase of antimicrobial-resistant bacteria and dysbiosis of the beneficial microbial communities. While an increasing number of studies investigate the effects of antimicrobial administration on swine gastrointestinal microbiota biodiversity, the impact of their use on the composition and diversity of nasal microbial communities has not been widely explored. The objective of this study was to characterize the short-term impact of different parenteral antibiotics administration on the composition and diversity of nasal microbial communities in growing pigs. Five antimicrobial treatment groups, each consisting of four, eight-week old piglets, were administered one of the antimicrobials; Ceftiofur Crystalline free acid (CCFA), Ceftiofur hydrochloride (CHC), Tulathromycin (TUL), Oxytetracycline (OTC), and Procaine Penicillin G (PPG) at label dose and route. Individual deep nasal swabs were collected immediately before antimicrobial administration (control = day 0), and again on days 1, 3, 7, and 14 after dosing. The nasal microbiota across all the samples were dominated by Firmicutes, proteobacteria and Bacteroidetes. While, the predominant bacterial genera were Moraxella, Clostridium and Streptococcus. Linear discriminant analysis, showed a pronounced, antimicrobial-dependent microbial shift in the composition of nasal microbiota and over time from day 0. By day 14, the nasal microbial compositions of the groups receiving CCFA and OTC had returned to a distribution that closely resembled that observed on day 0. In contrast, pigs that received CHC, TUL and PPG appeared to deviate away from the day 0 composition by day 14. Based on our results, it appears that the impact of parenteral antibiotics on the swine nasal microbiota is variable and has a considerable impact in modulating the nasal microbiota structure. Our results will aid in developing alternative strategies for antibiotics to improve swine health and consequently production. Published by Elsevier Ltd.

[Isolation of the ergot (Claviceps purpurea (Fr.) Tul., strain VKM-F-366D), producing the lactamic alkaloid ergocornam].

PubMed

Komarova, E L; Shain, S S; Sheĭchenko, V I

2002-01-01

A new ergot strain VKM-F-3662D producing lactamic alkaloid ergocornam with concomitant alkaloids valinamide and ergometrine was isolated during selective works with sclerotium MS-462, which was obtained from ergocryptine ergot strain VKM-F-2642D. The structure of these alkaloids was determined by 1H and 13C NMR.

U.S. EPA, Pesticide Product Label, PRENTOX 35% MALATHION OIL SOLUBLE CONC. - REFINED, 10/03/1983

EPA Pesticide Factsheets

2011-04-14

... 1. ~':}l.lt .tt.%r C1lP llll dat.a leciulrfA(~ tul It.'(ji&t.Illtiull/ It!rt:'glf;:tldt.lOH (It Y0UI l·rOduct und~r i·l ... ..A t;ec .. )(c) (~) "t.er. tl.e I .. (.:t I.('j' lef';\\lllt.! .. :li. ...

The ability of individuals to assess population density influences the evolution of emigration propensity and dispersal distance.

PubMed

Poethke, Hans Joachim; Gros, Andreas; Hovestadt, Thomas

2011-08-07

We analyze the simultaneous evolution of emigration and settlement decisions for actively dispersing species differing in their ability to assess population density. Using an individual-based model we simulate dispersal as a multi-step (patch to patch) movement in a world consisting of habitat patches surrounded by a hostile matrix. Each such step is associated with the same mortality risk. Our simulations show that individuals following an informed strategy, where emigration (and settlement) probability depends on local population density, evolve a lower (natal) emigration propensity but disperse over significantly larger distances - i.e. postpone settlement longer - than individuals performing density-independent emigration. This holds especially when variation in environmental conditions is spatially correlated. Both effects can be traced to the informed individuals' ability to better exploit existing heterogeneity in reproductive chances. Yet, already moderate distance-dependent dispersal costs prevent the evolution of multi-step (long-distance) dispersal, irrespective of the dispersal strategy. Copyright © 2011 Elsevier Ltd. All rights reserved.

Modeling Stepped Leaders Using a Time Dependent Multi-dipole Model and High-speed Video Data

NASA Astrophysics Data System (ADS)

Karunarathne, S.; Marshall, T.; Stolzenburg, M.; Warner, T. A.; Orville, R. E.

2012-12-01

In summer of 2011, we collected lightning data with 10 stations of electric field change meters (bandwidth of 0.16 Hz - 2.6 MHz) on and around NASA/Kennedy Space Center (KSC) covering nearly 70 km × 100 km area. We also had a high-speed video (HSV) camera recording 50,000 images per second collocated with one of the electric field change meters. In this presentation we describe our use of these data to model the electric field change caused by stepped leaders. Stepped leaders of a cloud to ground lightning flash typically create the initial path for the first return stroke (RS). Most of the time, stepped leaders have multiple complex branches, and one of these branches will create the ground connection for the RS to start. HSV data acquired with a short focal length lens at ranges of 5-25 km from the flash are useful for obtaining the 2-D location of these multiple branches developing at the same time. Using HSV data along with data from the KSC Lightning Detection and Ranging (LDAR2) system and the Cloud to Ground Lightning Surveillance System (CGLSS), the 3D path of a leader may be estimated. Once the path of a stepped leader is obtained, the time dependent multi-dipole model [ Lu, Winn,and Sonnenfeld, JGR 2011] can be used to match the electric field change at various sensor locations. Based on this model, we will present the time-dependent charge distribution along a leader channel and the total charge transfer during the stepped leader phase.

TEACH-M: A pilot study evaluating an instructional sequence for persons with impaired memory and executive functions.

PubMed

Ehlhardt, L A; Sohlberg, M M; Glang, A; Albin, R

2005-08-10

The purpose of this pilot study was to evaluate an instructional package that facilitates learning and retention of multi-step procedures for persons with severe memory and executive function impairments resulting from traumatic brain injury. The study used a multiple baseline across participants design. Four participants, two males and two females, ranging in age from 36-58 years, were taught a 7-step e-mail task. The instructional package (TEACH-M) was the experimental intervention and the number of correct e-mail steps learned was the dependent variable. Treatment effects were replicated across the four participants and maintained at 30 days post-treatment. Generalization and social validity data further supported the treatment programme. The results suggest that individuals with severe cognitive impairments are capable of learning new skills. Directions for future research include application of the instructional package to other multi-step procedures.

Asynchronous adaptive time step in quantitative cellular automata modeling

PubMed Central

Zhu, Hao; Pang, Peter YH; Sun, Yan; Dhar, Pawan

2004-01-01

Background The behaviors of cells in metazoans are context dependent, thus large-scale multi-cellular modeling is often necessary, for which cellular automata are natural candidates. Two related issues are involved in cellular automata based multi-cellular modeling: how to introduce differential equation based quantitative computing to precisely describe cellular activity, and upon it, how to solve the heavy time consumption issue in simulation. Results Based on a modified, language based cellular automata system we extended that allows ordinary differential equations in models, we introduce a method implementing asynchronous adaptive time step in simulation that can considerably improve efficiency yet without a significant sacrifice of accuracy. An average speedup rate of 4–5 is achieved in the given example. Conclusions Strategies for reducing time consumption in simulation are indispensable for large-scale, quantitative multi-cellular models, because even a small 100 × 100 × 100 tissue slab contains one million cells. Distributed and adaptive time step is a practical solution in cellular automata environment. PMID:15222901

Congenital malformations and other reproductive losses in goats due to poisoning by Poincianella pyramidalis (Tul.) L.P. Queiroz (=Caesalpinia pyramidalis Tul.).

PubMed

Santos Dos Reis, Suélen Dias; de Oliveira, Ricardo Santana; Correia Marcelino, Sóstenes Apolo; Silva Almeida E Macêdo, Juliana Targino; Riet-Correa, Franklin; da Anunciação Pimentel, Luciano; Ocampos Pedroso, Pedro Miguel

2016-08-01

In the semiarid region of Brazil, in areas with vegetation composed mainly of Poincianella pyramidalis, several cases of congenital malformation and reproductive losses were observed in goats and sheep from 2012 to 2014. To determine the teratogenic effect of P. pyramidalis, two groups of eight goats each were used. Goats from Group 1 received fresh P. pyramidalis, harvested daily, as the only roughage during the whole breeding and pregnancy period. Goats in Group 2 (control) received Cynodon dactylon (tifton) hay free choice. Ultrasound examination for pregnancy diagnosis was performed every 28 days. Four goats from Group 1 were pregnant on day 28 but not on day 56, suggesting embryonic death or abortion. Another goat from Group 1 died at day 70 of pregnancy, and the fetuses exhibited micrognathia. The other three goats bore six kids, three of which showed bone malformations in the limbs, spine, ribs, sternum, and head, including arthrogryposis, scoliosis and micrognathia. One kid also showed hypoplasia of the left pulmonary lobes. In the control group, all goats bore a total of 13 kids and none of them exhibited malformations. These results demonstrated that P. pyramidalis causes congenital malformations and other reproductive losses in goats. Copyright © 2016 Elsevier Ltd. All rights reserved.

Unifying Temporal and Structural Credit Assignment Problems

NASA Technical Reports Server (NTRS)

Agogino, Adrian K.; Tumer, Kagan

2004-01-01

Single-agent reinforcement learners in time-extended domains and multi-agent systems share a common dilemma known as the credit assignment problem. Multi-agent systems have the structural credit assignment problem of determining the contributions of a particular agent to a common task. Instead, time-extended single-agent systems have the temporal credit assignment problem of determining the contribution of a particular action to the quality of the full sequence of actions. Traditionally these two problems are considered different and are handled in separate ways. In this article we show how these two forms of the credit assignment problem are equivalent. In this unified frame-work, a single-agent Markov decision process can be broken down into a single-time-step multi-agent process. Furthermore we show that Monte-Carlo estimation or Q-learning (depending on whether the values of resulting actions in the episode are known at the time of learning) are equivalent to different agent utility functions in a multi-agent system. This equivalence shows how an often neglected issue in multi-agent systems is equivalent to a well-known deficiency in multi-time-step learning and lays the basis for solving time-extended multi-agent problems, where both credit assignment problems are present.

Inverting the planning gradient: adjustment of grasps to late segments of multi-step object manipulations.

PubMed

Mathew, Hanna; Kunde, Wilfried; Herbort, Oliver

2017-05-01

When someone grasps an object, the grasp depends on the intended object manipulation and usually facilitates it. If several object manipulation steps are planned, the first step has been reported to primarily determine the grasp selection. We address whether the grasp can be aligned to the second step, if the second step's requirements exceed those of the first step. Participants grasped and rotated a dial first by a small extent and then by various extents in the opposite direction, without releasing the dial. On average, when the requirements of the first and the second step were similar, participants mostly aligned the grasp to the first step. When the requirements of the second step were considerably higher, participants aligned the grasp to the second step, even though the first step still had a considerable impact. Participants employed two different strategies. One subgroup initially aligned the grasp to the first step and then ceased adjusting the grasp to either step. Another group also initially aligned the grasp to the first step and then switched to aligning it primarily to the second step. The data suggest that participants are more likely to switch to the latter strategy when they experienced more awkward arm postures. In summary, grasp selections for multi-step object manipulations can be aligned to the second object manipulation step, if the requirements of this step clearly exceed those of the first step and if participants have some experience with the task.

Critical induction a key quantity for the optimisation of transformer core operation

NASA Astrophysics Data System (ADS)

Ilo, A.; Pfützner, H.; Nakata, T.

2000-06-01

No-load losses P of transformers core have been considerably decreased through introduction of the so-called multi-step-lap designs. However, profound guidelines for the optimum step-number N do not exist. This study shows that the combination of both N and working induction B characterises the flux distribution. Transformer cores can operate in an over or an under-critical way depending on N and B.

What are the socioeconomic implications of the value chain of biodiversity products? A case study in Northeastern Brazil.

PubMed

da Silva, Rafael Ricardo Vasconcelos; Gomes, Laura Jane; Albuquerque, Ulysses Paulino

2017-02-01

The trade in biodiversity products has gained increasing importance in conservation and livelihood strategies. The aim of this study is to describe and analyze the socioeconomic aspects and dynamics of the production and commercialization of two important products of Brazilian biodiversity from the fruits of Caryocar coriaceum Wittm. and Dimorphandra gardneriana Tul. Interviews were conducted with who were involved in the various stages of value chains. Data were analyzed under an analytical/descriptive approach. It was found that the two value chains under study, although they share the same production environment and workforce, are different models of the commercial appropriation of the forest environment: one is related to local traditions, whereas the other seeks to meet an industry-related demand originating from a multinational pharmaceutical company. Harvesters become highly dependent on the trends imposed by these markets. Thus, it is clear that promoting these products as a conservation strategy requires an understanding of how their value chains arise, are established, and operate.

Essential oil from the leaves of Xylopia langsdorfiana (Annonaceae) as a possible spasmolytic agent.

PubMed

Correia, Ana Carolina de C; Ferreira, Tamyris F; Martins, Italo Rossi R; Macêdo, Cibério L; Monteiro, Fabio de S; Costa, Vicente Carlos O; Tavares, Josean F; Silva, Marcelo S; Paredes-Gamero, Edgar J; Buri, Marcus V; Rigoni, Vera L S; Nouailhetas, Viviane L A; Da Silva, Bagnólia A

2015-01-01

Xylopia langsdorfiana A. St.-Hil. &Tul. (Annonaceae) is popularly known in the northeast of Brazil as 'pimenteira da terra', and an essential oil (XL-OE) was extracted from its leaves. Since Xylopia species are cited in folk medicine and diterpenes from X. langsdorfiana have spasmolytic activity, this study aimed to investigate a possible spasmolytic action of XL-OE on smooth muscle models. XL-OE (243 and 729 μg/mL) showed low pharmacologic efficacy on guinea pig trachea and rat aorta and uterus. However, in guinea pig ileum, XL-OE (27-729 μg/mL) inhibited carbachol or histamine-induced phasic contractions (1 μM) in a significant and concentration-dependent manner. In addition, XL-OE (81 μg/mL) reduced fluorescence intensity in ileal myocytes stimulated by histamine, indicating a decrease in cytosolic calcium concentration, which could explain the spasmolytic activity. Thus, XL-OE proved to be a promising natural product to be used in gastrointestinal diseases acting by modulating the cytosolic calcium concentration.

Underground structure pattern and multi AO reaction with step feed concept for upgrading an large wastewater treatment plant

NASA Astrophysics Data System (ADS)

Peng, Yi; Zhang, Jie; Li, Dong

2018-03-01

A large wastewater treatment plant (WWTP) could not meet the new demand of urban environment and the need of reclaimed water in China, using a US treatment technology. Thus a multi AO reaction process (Anaerobic/oxic/anoxic/oxic/anoxic/oxic) WWTP with underground structure was proposed to carry out the upgrade project. Four main new technologies were applied: (1) multi AO reaction with step feed technology; (2) deodorization; (3) new energy-saving technology such as water resource heat pump and optical fiber lighting system; (4) dependable old WWTP’s water quality support measurement during new WWTP’s construction. After construction, upgrading WWTP had saved two thirds land occupation, increased 80% treatment capacity and improved effluent standard by more than two times. Moreover, it had become a benchmark of an ecological negative capital changing to a positive capital.

Genetic variation for resistance to ergot (Claviceps purpurea [Fr.] Tul.) among full-sib families of five populations of winter rye (Secale cereale L.).

PubMed

Mirdita, V; Dhillon, B S; Geiger, H H; Miedaner, T

2008-12-01

Ergot (Claviceps purpurea [Fr.] Tul.) is a serious disease of rye (Secale cereale L.) and it adversely affects the quality of grain. The present investigation was undertaken to study genotypic variability among full-sib families (FSF) of five open-pollinated (OP) winter rye populations of highly diverse origin, namely Dankovskie Selekcyine (Poland), Charkovskaja (Ukraine), NEM4 (Russia), Halo and Carokurz, both from Germany. About 50 FSF were developed at random in each population, and the FSF of each population were evaluated in separate but adjacent experiments conducted in four environments under artificial inoculation. A mixture of conidia of C. purpurea isolates was sprayed thrice during the flowering period. The materials were manually harvested at yellow-ripe stage. Resistance trait recorded was disease severity, i.e. percent ergot sclerotia in grain by weight. Mean ergot severity ranged from 2.29 to 4.08% for the five populations across environments. Significant genotypic variation (P < 0.01) due to FSF and FSF x environment interaction was observed within each population. Genotypic variation within all populations was higher than that among five populations. All populations showed high estimates of heritability (0.72-0.89). The study indicated that the evaluated OP populations are rich reservoirs of genetic variation that should also be used in hybrid breeding. Recurrent selection to further improve ergot resistance should be successful.

Evaluation of the Interaction between the Poincianella pyramidalis (Tul.) LP Queiroz Extract and Antimicrobials Using Biological and Analytical Models.

PubMed

Chaves, Thiago P; Fernandes, Felipe Hugo A; Santana, Cleildo P; Santos, Jocimar S; Medeiros, Francinalva D; Felismino, Délcio C; Santos, Vanda L; Catão, Raïssa Mayer R; Coutinho, Henrique Douglas M; Medeiros, Ana Cláudia D

2016-01-01

Poincianella pyramidalis (Tul.) LP Queiroz (Fabaceae) is an endemic tree of northeastern Brazil, occurring mainly in the Caatinga. Its medicinal use is widespread and is an important therapeutic option against diarrhea, dysentery, and respiratory and urinary infections, among other diseases. In this study we determined the chemical marker and evaluated the interaction between P. pyramidalis extract and a commercial antimicrobial through the use of biological and analytical models. To obtain the extract, an ethanol-water mixture (50:50 v/v) was used as solvent. It was nebulized in a spray dryer using colloidal silicon dioxide as a drying adjuvant. The extract (ENPp) was subjected to HPLC analysis to verify the presence of certain secondary metabolites. The Minimum Inhibitory Concentration (MIC) of the extract against Gram-negative bacteria was determined by broth microdilution and the MIC of synthetic antimicrobial drugs in the presence and absence of the extract. The antioxidant activity of ENPp was evaluated by the DPPH method. The compatibility between the antimicrobial and the extract was evaluated by thermal analysis (TG/DTA). The acute toxicity of the extract was evaluated in vivo in rodents. The results indicate significant additive action of the extract on synthetic antibiotics, considerable antioxidant activity and absence of toxicity. This extract shows high potential for the development of formulations for antimicrobial therapy when used with a vegetable-active ingredient.

Evaluation of the Interaction between the Poincianella pyramidalis (Tul.) LP Queiroz Extract and Antimicrobials Using Biological and Analytical Models

PubMed Central

Santana, Cleildo P.; Medeiros, Francinalva D.; Felismino, Délcio C.; Santos, Vanda L.; Catão, Raïssa Mayer R.; Coutinho, Henrique Douglas M.

2016-01-01

Poincianella pyramidalis (Tul.) LP Queiroz (Fabaceae) is an endemic tree of northeastern Brazil, occurring mainly in the Caatinga. Its medicinal use is widespread and is an important therapeutic option against diarrhea, dysentery, and respiratory and urinary infections, among other diseases. In this study we determined the chemical marker and evaluated the interaction between P. pyramidalis extract and a commercial antimicrobial through the use of biological and analytical models. To obtain the extract, an ethanol-water mixture (50:50 v/v) was used as solvent. It was nebulized in a spray dryer using colloidal silicon dioxide as a drying adjuvant. The extract (ENPp) was subjected to HPLC analysis to verify the presence of certain secondary metabolites. The Minimum Inhibitory Concentration (MIC) of the extract against Gram-negative bacteria was determined by broth microdilution and the MIC of synthetic antimicrobial drugs in the presence and absence of the extract. The antioxidant activity of ENPp was evaluated by the DPPH method. The compatibility between the antimicrobial and the extract was evaluated by thermal analysis (TG/DTA). The acute toxicity of the extract was evaluated in vivo in rodents. The results indicate significant additive action of the extract on synthetic antibiotics, considerable antioxidant activity and absence of toxicity. This extract shows high potential for the development of formulations for antimicrobial therapy when used with a vegetable-active ingredient. PMID:27192209

The Ethanol Extract of the Inner Bark of Caesalpinia pyramidalis (Tul.) Reduces Urinary Bladder Damage during Cyclophosphamide-Induced Cystitis in Rats

PubMed Central

Moraes, Janaína P.; Pereira, Denyson S.; Matos, Alexandre S.; Santana, Danielle G.; Santos, Cliomar A.; Estevam, Charles S.; Fakhouri, Ricardo; de Lucca Junior, Waldecy; Camargo, Enilton A.

2013-01-01

Hemorrhagic cystitis (HC) is a common side effect of cyclophosphamide therapy, which deserves new therapeutic strategies, such as those based on natural products. The ethanol extract of the inner bark of Caesalpinia pyramidalis (Tul.) (EECp) possesses anti-inflammatory, antinociceptive, and antioxidant activities as previously showed by our group. We have investigated the effect of EECp on the cyclophosphamide-induced HC. Cystitis was induced in male Wistar rats by the injection of cyclophosphamide. These animals were pretreated with EECp (100–400 mg/kg), vehicle, or mesna. Myeloperoxidase activity and malondialdehyde formation were measured in urinary bladder and other tissues. Bladder edema and histopathological alterations and serum nitric oxide metabolites concentration NOx − were also evaluated. Treatment with EECp (100–400 mg/kg) or mesna impaired the increase of myeloperoxidase activity in urinary bladder and the serum NOx − induced by cyclophosphamide but did not reduce edema in this tissue, as did mesna. Total histological score was reduced by EECp (100 mg/kg). Lung myeloperoxidase activity, which was increased by cyclophosphamide, was decreased significantly by EECp (400 mg/kg). EECp also diminished the malondialdehyde formation in bladder, lung, and spleen, although these parameters were not affected by cyclophosphamide. These results indicate that EECp reduced urinary bladder damage during cyclophosphamide-induced HC in rats. PMID:24348180

Seismic data enhancement and regularization using finite offset Common Diffraction Surface (CDS) stack

NASA Astrophysics Data System (ADS)

Garabito, German; Cruz, João Carlos Ribeiro; Oliva, Pedro Andrés Chira; Söllner, Walter

2017-01-01

The Common Reflection Surface stack is a robust method for simulating zero-offset and common-offset sections with high accuracy from multi-coverage seismic data. For simulating common-offset sections, the Common-Reflection-Surface stack method uses a hyperbolic traveltime approximation that depends on five kinematic parameters for each selected sample point of the common-offset section to be simulated. The main challenge of this method is to find a computationally efficient data-driven optimization strategy for accurately determining the five kinematic stacking parameters on which each sample of the stacked common-offset section depends. Several authors have applied multi-step strategies to obtain the optimal parameters by combining different pre-stack data configurations. Recently, other authors used one-step data-driven strategies based on a global optimization for estimating simultaneously the five parameters from multi-midpoint and multi-offset gathers. In order to increase the computational efficiency of the global optimization process, we use in this paper a reduced form of the Common-Reflection-Surface traveltime approximation that depends on only four parameters, the so-called Common Diffraction Surface traveltime approximation. By analyzing the convergence of both objective functions and the data enhancement effect after applying the two traveltime approximations to the Marmousi synthetic dataset and a real land dataset, we conclude that the Common-Diffraction-Surface approximation is more efficient within certain aperture limits and preserves at the same time a high image accuracy. The preserved image quality is also observed in a direct comparison after applying both approximations for simulating common-offset sections on noisy pre-stack data.

48 CFR 15.202 - Advisory multi-step process.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Advisory multi-step... Information 15.202 Advisory multi-step process. (a) The agency may publish a presolicitation notice (see 5.204... participate in the acquisition. This process should not be used for multi-step acquisitions where it would...

Introduction to Remote Sensing Image Registration

NASA Technical Reports Server (NTRS)

Le Moigne, Jacqueline

2017-01-01

For many applications, accurate and fast image registration of large amounts of multi-source data is the first necessary step before subsequent processing and integration. Image registration is defined by several steps and each step can be approached by various methods which all present diverse advantages and drawbacks depending on the type of data, the type of applications, the a prior information known about the data and the type of accuracy that is required. This paper will first present a general overview of remote sensing image registration and then will go over a few specific methods and their applications

Multi-exponential analysis of magnitude MR images using a quantitative multispectral edge-preserving filter.

PubMed

Bonny, Jean Marie; Boespflug-Tanguly, Odile; Zanca, Michel; Renou, Jean Pierre

2003-03-01

A solution for discrete multi-exponential analysis of T(2) relaxation decay curves obtained in current multi-echo imaging protocol conditions is described. We propose a preprocessing step to improve the signal-to-noise ratio and thus lower the signal-to-noise ratio threshold from which a high percentage of true multi-exponential detection is detected. It consists of a multispectral nonlinear edge-preserving filter that takes into account the signal-dependent Rician distribution of noise affecting magnitude MR images. Discrete multi-exponential decomposition, which requires no a priori knowledge, is performed by a non-linear least-squares procedure initialized with estimates obtained from a total least-squares linear prediction algorithm. This approach was validated and optimized experimentally on simulated data sets of normal human brains.

Analysis of the phosphorescent dye concentration dependence of triplet-triplet annihilation in organic host-guest systems

NASA Astrophysics Data System (ADS)

Zhang, L.; van Eersel, H.; Bobbert, P. A.; Coehoorn, R.

2016-10-01

Using a novel method for analyzing transient photoluminescence (PL) experiments, a microscopic description is obtained for the dye concentration dependence of triplet-triplet annihilation (TTA) in phosphorescent host-guest systems. It is demonstrated that the TTA-mechanism, which could be a single-step dominated process or a diffusion-mediated multi-step process, can be deduced for any given dye concentration from a recently proposed PL intensity analysis. A comparison with the results of kinetic Monte Carlo simulations provides the TTA-Förster radius and shows that the TTA enhancement due to triplet diffusion can be well described in a microscopic manner assuming Förster- or Dexter-type energy transfer.

Antiplasmodial, cytotoxic activities and characterization of a new naturally occurring quinone methide pentacyclic triterpenoid derivative isolated from Salacia leptoclada Tul. (Celastraceae) originated from Madagascar

PubMed Central

Ruphin, Fatiany Pierre; Baholy, Robijaona; Emmanue, Andrianarivo; Amelie, Raharisololalao; Martin, Marie-Therese; Koto-te-Nyiwa, Ngbolua

2013-01-01

Objective To validate scientifically the traditional use of Salacia leptoclada Tul. (Celastraceae) (S. leptoclada) and to isolate and elucidate the structure of the biologically active compound. Methods Bioassay-guided fractionation of the acetonic extract of the stem barks of S. leptoclada was carried out by a combination of chromatography technique and biological experiments in viro using Plasmodium falciparum and P388 leukemia cell lines as models. The structure of the biologically active pure compound was elucidated by 1D and 2D NMR spectroscopy and mass spectrometry. Results Biological screening of S. leptoclada extracts resulted in the isolation of a pentacyclic triterpenic quinone methide. The pure compound exhibited both in vitro a cytotoxic effect on murine P388 leukemia cells with IC50 value of (0.041±0.020) µg/mL and an antiplasmodial activity against the chloroquine-resistant strain FC29 of Plasmodium falciparum with an IC50 value of (0.052±0.030) µg/mL. Despite this interesting anti-malarial property of the lead compound, the therapeutic index was weak (0.788). In the best of our knowledge, the quinone methide pentacyclic triterpenoid derivative compound is reported for the first time in S. leptoclada. Conclusions The results suggest that furthers studies involving antineoplastic activity is needed for the development of this lead compound as anticancer drug. PMID:24075342

Antiplasmodial, cytotoxic activities and characterization of a new naturally occurring quinone methide pentacyclic triterpenoid derivative isolated from Salacia leptoclada Tul. (Celastraceae) originated from Madagascar.

PubMed

Ruphin, Fatiany Pierre; Baholy, Robijaona; Emmanue, Andrianarivo; Amelie, Raharisololalao; Martin, Marie-Therese; Koto-te-Nyiwa, Ngbolua

2013-10-01

To validate scientifically the traditional use of Salacia leptoclada Tul. (Celastraceae) (S. leptoclada) and to isolate and elucidate the structure of the biologically active compound. Bioassay-guided fractionation of the acetonic extract of the stem barks of S. leptoclada was carried out by a combination of chromatography technique and biological experiments in viro using Plasmodium falciparum and P388 leukemia cell lines as models. The structure of the biologically active pure compound was elucidated by 1D and 2D NMR spectroscopy and mass spectrometry. Biological screening of S. leptoclada extracts resulted in the isolation of a pentacyclic triterpenic quinone methide. The pure compound exhibited both in vitro a cytotoxic effect on murine P388 leukemia cells with IC50 value of (0.041±0.020) μg/mL and an antiplasmodial activity against the chloroquine-resistant strain FC29 of Plasmodium falciparum with an IC50 value of (0.052±0.030) μg/mL. Despite this interesting anti-malarial property of the lead compound, the therapeutic index was weak (0.788). In the best of our knowledge, the quinone methide pentacyclic triterpenoid derivative compound is reported for the first time in S. leptoclada. The results suggest that furthers studies involving antineoplastic activity is needed for the development of this lead compound as anticancer drug. Copyright © 2013 Asian Pacific Tropical Biomedical Magazine. Published by Elsevier B.V. All rights reserved.

Genetic diversity in a Poincianella pyramidalis (Tul.) L.P. Queiroz population assessed by RAPD molecular markers.

PubMed

Belarmino, K S; Rêgo, M M; Bruno, R L A; Medeiros, G D A; Andrade, A P; Rêgo, E R

2017-08-31

Poincianella pyramidalis (Tul.) L.P. Queiroz is an endemic Caatinga (Brazilian savannah biome) species that has been exploited for different purposes, although information is necessary about still existing natural populations. The objective of this study was to evaluate the genetic diversity among 20 P. pyramidalis individuals occurring in a population localized in the Caatinga biome of Paraíba State, aiming at seed collection, using RAPD markers. For the DNA extraction, young shoots of the individuals were used, and amplification was carried out using 20 primers. The obtained markers were converted to a binary matrix, from which a genetic dissimilarity matrix was built using the arithmetic complement of Jaccard's coefficient, and the dendrogram was built by the UPGMA analysis. No amplified fragment was monomorphic, resulting in 100% polymorphism of the analyzed population. The mean genetic diversity among the matrices was 63.28%, ranging from 30.9 to 97.7%. Individuals 09 and 17 showed relevant genetic proximity, and thus planting their seedlings at close sites would not be indicated. The population evaluated in this study showed high genetic diversity, originating twelve groups from the UPGMA hierarchical cluster analysis. Based on the results, individuals 09 and 17 can provide plant material for the evaluation of the physiological performance of P. pyramidalis seeds, and the set of individuals of this population has a high genetic diversity that characterizes them as adequate matrices for projects of restoration and conservation of the seed species.

Failure Analysis of a Complex Learning Framework Incorporating Multi-Modal and Semi-Supervised Learning

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pullum, Laura L; Symons, Christopher T

2011-01-01

Machine learning is used in many applications, from machine vision to speech recognition to decision support systems, and is used to test applications. However, though much has been done to evaluate the performance of machine learning algorithms, little has been done to verify the algorithms or examine their failure modes. Moreover, complex learning frameworks often require stepping beyond black box evaluation to distinguish between errors based on natural limits on learning and errors that arise from mistakes in implementation. We present a conceptual architecture, failure model and taxonomy, and failure modes and effects analysis (FMEA) of a semi-supervised, multi-modal learningmore » system, and provide specific examples from its use in a radiological analysis assistant system. The goal of the research described in this paper is to provide a foundation from which dependability analysis of systems using semi-supervised, multi-modal learning can be conducted. The methods presented provide a first step towards that overall goal.« less

Multi-Step Attack Detection via Bayesian Modeling under Model Parameter Uncertainty

ERIC Educational Resources Information Center

Cole, Robert

2013-01-01

Organizations in all sectors of business have become highly dependent upon information systems for the conduct of business operations. Of necessity, these information systems are designed with many points of ingress, points of exposure that can be leveraged by a motivated attacker seeking to compromise the confidentiality, integrity or…

The evolution of lifespan and age-dependent cancer risk.

PubMed

Rozhok, Andrii I; DeGregori, James

2016-10-01

The Armitage-Doll multi-stage model of carcinogenesis tremendously refocused cancer science by postulating that carcinogenesis is driven by a sequence of genetic changes in cells. Age-dependent cancer incidence thus has been explained in terms of the time necessary for oncogenic mutations to occur. While the multi-step nature of cancer evolution is well-supported by evidence, the mutation-centric theory is unable to explain a number of phenomena, such as the disproportion between cancer frequency and animal body size or the scaling of cancer incidence to animal lifespan. In this paper, we present a theoretical review of the current paradigm and discuss some fundamental evolutionary theory postulates that explain why cancer incidence is a function of lifespan and physiological, not chronological, aging.

Summary of Research, Academic Departments, 1983-1984.

DTIC Science & Technology

1984-10-01

miagnetoelast ic strain gauiges. hydraulic (ollrols svsteiiis, robotics, aiiol gas tul-ili( engine (lilic(’. Th’lis wear, e’Ii phasis has beent placed...gatige, the( gifligV id~ itsSsigiifI Co(lifltioflihlg. High Level Real-Time Software for Hydraulic Control Systems in Deep Submergence Vehicles h~iSiAt...Simulation of a Hydraulic Control System At )VISUMt: ASSOCIATII PiiOtISSOt1 IAIU IIB V. I I)L SKA\\ Theo Jriluialrv pourpose of’ this l’C51’drch is to) wxIihi

Initial and long-term bond strengths of one-step self-etch adhesives with silane coupling agent to enamel-dentin-composite in combined situation.

PubMed

Mamanee, Teerapong; Takahashi, Masahiro; Nakajima, Masatoshi; Foxton, Richard M; Tagami, Junji

2015-01-01

This study evaluated the effect of adding silane coupling agent on initial and long-term bond strengths of one-step self-etch adhesives to enamel-dentin-composite in combined situation. Cervical cavities were prepared on extracted molars and filled with Clearfil AP-X. After water-storage for one-week, the filled teeth were sectioned in halves to expose enamel, dentin and composite surfaces and then enamel-dentin-composite surface was totally applied with one of adhesive treatments (Clearfil SE One, Clearfil SE One with Clearfil Porcelain Bond Activator, Beautibond Multi, Beautibond Multi with Beautibond Multi PR Plus and Scotchbond Universal). After designed period, micro-shear bond strengths (µSBSs) to each substrate were determined. For each period of water-storage, additive silane treatments significantly increased µSBS to composite (p<0.001). On the other hand, they significantly decreased µSBS to dentin (p<0.001), although did not have adverse effect on µSBS to enamel (p>0.05). Moreover, the stability of µSBS was depended on materials and substrates used.

A novel design solution to the fraenal notch of maxillary dentures.

PubMed

White, J A P; Bond, I P; Jagger, D C

2013-09-01

This study investigates a novel design feature for the fraenal notch of maxillary dentures, using computational and experimental methods, and shows that its use could significantly increase the longevity of the prosthesis. A two-step process can be used to create the design feature with current denture base materials, but would be highly dependent on the individual skill of the dental technician. Therefore, an alternative form of manufacture, multi-material additive layer manufacture (or '3D printing'), has been proposed as a future method for the direct production of complete dentures with multi-material design features.

Models of Alcohol and Other Drug Treatment for Consideration When Working with Deaf and Hard of Hearing Individuals.

ERIC Educational Resources Information Center

Guthmann, Debra

This paper discusses several models for treating chemical dependency in individuals who are deaf or hard of hearing. It begins by describing the 12-step model, a comprehensive, multi-disciplinary approach to the treatment of addiction which is abstinence oriented and based on the principles of Alcoholics Anonymous. This model includes group…

Parallel Multi-Step/Multi-Rate Integration of Two-Time Scale Dynamic Systems

NASA Technical Reports Server (NTRS)

Chang, Johnny T.; Ploen, Scott R.; Sohl, Garett. A,; Martin, Bryan J.

2004-01-01

Increasing demands on the fidelity of simulations for real-time and high-fidelity simulations are stressing the capacity of modern processors. New integration techniques are required that provide maximum efficiency for systems that are parallelizable. However many current techniques make assumptions that are at odds with non-cascadable systems. A new serial multi-step/multi-rate integration algorithm for dual-timescale continuous state systems is presented which applies to these systems, and is extended to a parallel multi-step/multi-rate algorithm. The superior performance of both algorithms is demonstrated through a representative example.

Analysis of Critical Infrastructure Dependencies and Interdependencies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Petit, Frederic; Verner, Duane; Brannegan, David

2015-06-01

The report begins by defining dependencies and interdependencies and exploring basic concepts of dependencies in order to facilitate a common understanding and consistent analytical approaches. Key concepts covered include; Characteristics of dependencies: upstream dependencies, internal dependencies, and downstream dependencies; Classes of dependencies: physical, cyber, geographic, and logical; and Dimensions of dependencies: operating environment, coupling and response behavior, type of failure, infrastructure characteristics, and state of operations From there, the report proposes a multi-phase roadmap to support dependency and interdependency assessment activities nationwide, identifying a range of data inputs, analysis activities, and potential products for each phase, as well as keymore » steps needed to progress from one phase to the next. The report concludes by outlining a comprehensive, iterative, and scalable framework for analyzing dependencies and interdependencies that stakeholders can integrate into existing risk and resilience assessment efforts.« less

On the Changes in Lift of Hydrofoils Due to Surface Injections of Polymer Additives

DTIC Science & Technology

1978-02-01

detailed dese rip tion oVi oh- J ectives . A discuosl on of’ the var~ous phyviva mechnnisms ILhat have boen pos tul a td i~n the U.1. Le ro uy to vxp 1 a...C’. C, .C’, CN 40 ’ 0 ’ ft V2 *Scn CN 0 .P. C, C, C. 0~ V, C3s0 0 s0S) -4 it 0kI l t (- to 55551 C. C!, 4" C, C .* ik kI4 4~~~ ~ *: it c 4 L 1% It

A time to search: finding the meaning of variable activation energy.

PubMed

Vyazovkin, Sergey

2016-07-28

This review deals with the phenomenon of variable activation energy frequently observed when studying the kinetics in the liquid or solid phase. This phenomenon commonly manifests itself through nonlinear Arrhenius plots or dependencies of the activation energy on conversion computed by isoconversional methods. Variable activation energy signifies a multi-step process and has a meaning of a collective parameter linked to the activation energies of individual steps. It is demonstrated that by using appropriate models of the processes, the link can be established in algebraic form. This allows one to analyze experimentally observed dependencies of the activation energy in a quantitative fashion and, as a result, to obtain activation energies of individual steps, to evaluate and predict other important parameters of the process, and generally to gain deeper kinetic and mechanistic insights. This review provides multiple examples of such analysis as applied to the processes of crosslinking polymerization, crystallization and melting of polymers, gelation, and solid-solid morphological and glass transitions. The use of appropriate computational techniques is discussed as well.

Multi-electrolyte-step anodic aluminum oxide method for the fabrication of self-organized nanochannel arrays

PubMed Central

2012-01-01

Nanochannel arrays were fabricated by the self-organized multi-electrolyte-step anodic aluminum oxide [AAO] method in this study. The anodization conditions used in the multi-electrolyte-step AAO method included a phosphoric acid solution as the electrolyte and an applied high voltage. There was a change in the phosphoric acid by the oxalic acid solution as the electrolyte and the applied low voltage. This method was used to produce self-organized nanochannel arrays with good regularity and circularity, meaning less power loss and processing time than with the multi-step AAO method. PMID:22333268

Mechanical and Metallurgical Evolution of Stainless Steel 321 in a Multi-step Forming Process

NASA Astrophysics Data System (ADS)

Anderson, M.; Bridier, F.; Gholipour, J.; Jahazi, M.; Wanjara, P.; Bocher, P.; Savoie, J.

2016-04-01

This paper examines the metallurgical evolution of AISI Stainless Steel 321 (SS 321) during multi-step forming, a process that involves cycles of deformation with intermediate heat treatment steps. The multi-step forming process was simulated by implementing interrupted uniaxial tensile testing experiments. Evolution of the mechanical properties as well as the microstructural features, such as twins and textures of the austenite and martensite phases, was studied as a function of the multi-step forming process. The characteristics of the Strain-Induced Martensite (SIM) were also documented for each deformation step and intermediate stress relief heat treatment. The results indicated that the intermediate heat treatments considerably increased the formability of SS 321. Texture analysis showed that the effect of the intermediate heat treatment on the austenite was minor and led to partial recrystallization, while deformation was observed to reinforce the crystallographic texture of austenite. For the SIM, an Olson-Cohen equation type was identified to analytically predict its formation during the multi-step forming process. The generated SIM was textured and weakened with increasing deformation.

Analyzing the dependence of oxygen incorporation current density on overpotential and oxygen partial pressure in mixed conducting oxide electrodes.

PubMed

Guan, Zixuan; Chen, Di; Chueh, William C

2017-08-30

The oxygen incorporation reaction, which involves the transformation of an oxygen gas molecule to two lattice oxygen ions in a mixed ionic and electronic conducting solid, is a ubiquitous and fundamental reaction in solid-state electrochemistry. To understand the reaction pathway and to identify the rate-determining step, near-equilibrium measurements have been employed to quantify the exchange coefficients as a function of oxygen partial pressure and temperature. However, because the exchange coefficient contains contributions from both forward and reverse reaction rate constants and depends on both oxygen partial pressure and oxygen fugacity in the solid, unique and definitive mechanistic assessment has been challenging. In this work, we derive a current density equation as a function of both oxygen partial pressure and overpotential, and consider both near and far from equilibrium limits. Rather than considering specific reaction pathways, we generalize the multi-step oxygen incorporation reaction into the rate-determining step, preceding and following quasi-equilibrium steps, and consider the number of oxygen ions and electrons involved in each. By evaluating the dependence of current density on oxygen partial pressure and overpotential separately, one obtains the reaction orders for oxygen gas molecules and for solid-state species in the electrode. We simulated the oxygen incorporation current density-overpotential curves for praseodymium-doped ceria for various candidate rate-determining steps. This work highlights a promising method for studying the exchange kinetics far away from equilibrium.

Surface Modified Particles By Multi-Step Addition And Process For The Preparation Thereof

DOEpatents

Cook, Ronald Lee; Elliott, Brian John; Luebben, Silvia DeVito; Myers, Andrew William; Smith, Bryan Matthew

2006-01-17

The present invention relates to a new class of surface modified particles and to a multi-step surface modification process for the preparation of the same. The multi-step surface functionalization process involves two or more reactions to produce particles that are compatible with various host systems and/or to provide the particles with particular chemical reactivities. The initial step comprises the attachment of a small organic compound to the surface of the inorganic particle. The subsequent steps attach additional compounds to the previously attached organic compounds through organic linking groups.

Powerful Voter Selection for Making Multistep Delegate Ballot Fair

NASA Astrophysics Data System (ADS)

Yamakawa, Hiroshi

For decision by majority, each voter often exercises his right by delegating to trustable other voters. Multi-step delegates rule allows indirect delegating through more than one voter, and this helps each voter finding his delegate voters. In this paper, we propose powerful voter selection method depending on the multi-step delegate rule. This method sequentially selects voters who is most delegated indirectly. Multi-agent simulation demonstrate that we can achieve highly fair poll results from small number of vote by using proposed method. Here, fairness is prediction accuracy to sum of all voters preferences for choices. In simulation, each voter selects choices arranged on one dimensional preference axis for voting. Acquaintance relationships among voters were generated as a random network, and each voter delegates some of his acquaintances who has similar preferences. We obtained simulation results from various acquaintance networks, and then averaged these results. Firstly, if each voter has enough acquaintances in average, proposed method can help predicting sum of all voters' preferences of choices from small number of vote. Secondly, if the number of each voter's acquaintances increases corresponding to an increase in the number of voters, prediction accuracy (fairness) from small number of vote can be kept in appropriate level.

Performance implications from sizing a VM on multi-core systems: A Data analytic application s view

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lim, Seung-Hwan; Horey, James L; Begoli, Edmon

In this paper, we present a quantitative performance analysis of data analytics applications running on multi-core virtual machines. Such environments form the core of cloud computing. In addition, data analytics applications, such as Cassandra and Hadoop, are becoming increasingly popular on cloud computing platforms. This convergence necessitates a better understanding of the performance and cost implications of such hybrid systems. For example, the very rst step in hosting applications in virtualized environments, requires the user to con gure the number of virtual processors and the size of memory. To understand performance implications of this step, we benchmarked three Yahoo Cloudmore » Serving Benchmark (YCSB) workloads in a virtualized multi-core environment. Our measurements indicate that the performance of Cassandra for YCSB workloads does not heavily depend on the processing capacity of a system, while the size of the data set is critical to performance relative to allocated memory. We also identi ed a strong relationship between the running time of workloads and various hardware events (last level cache loads, misses, and CPU migrations). From this analysis, we provide several suggestions to improve the performance of data analytics applications running on cloud computing environments.« less

Tracking Virus Particles in Fluorescence Microscopy Images Using Multi-Scale Detection and Multi-Frame Association.

PubMed

Jaiswal, Astha; Godinez, William J; Eils, Roland; Lehmann, Maik Jorg; Rohr, Karl

2015-11-01

Automatic fluorescent particle tracking is an essential task to study the dynamics of a large number of biological structures at a sub-cellular level. We have developed a probabilistic particle tracking approach based on multi-scale detection and two-step multi-frame association. The multi-scale detection scheme allows coping with particles in close proximity. For finding associations, we have developed a two-step multi-frame algorithm, which is based on a temporally semiglobal formulation as well as spatially local and global optimization. In the first step, reliable associations are determined for each particle individually in local neighborhoods. In the second step, the global spatial information over multiple frames is exploited jointly to determine optimal associations. The multi-scale detection scheme and the multi-frame association finding algorithm have been combined with a probabilistic tracking approach based on the Kalman filter. We have successfully applied our probabilistic tracking approach to synthetic as well as real microscopy image sequences of virus particles and quantified the performance. We found that the proposed approach outperforms previous approaches.

SHARP User Manual

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yu, Y. Q.; Shemon, E. R.; Thomas, J. W.

SHARP is an advanced modeling and simulation toolkit for the analysis of nuclear reactors. It is comprised of several components including physical modeling tools, tools to integrate the physics codes for multi-physics analyses, and a set of tools to couple the codes within the MOAB framework. Physics modules currently include the neutronics code PROTEUS, the thermal-hydraulics code Nek5000, and the structural mechanics code Diablo. This manual focuses on performing multi-physics calculations with the SHARP ToolKit. Manuals for the three individual physics modules are available with the SHARP distribution to help the user to either carry out the primary multi-physics calculationmore » with basic knowledge or perform further advanced development with in-depth knowledge of these codes. This manual provides step-by-step instructions on employing SHARP, including how to download and install the code, how to build the drivers for a test case, how to perform a calculation and how to visualize the results. Since SHARP has some specific library and environment dependencies, it is highly recommended that the user read this manual prior to installing SHARP. Verification tests cases are included to check proper installation of each module. It is suggested that the new user should first follow the step-by-step instructions provided for a test problem in this manual to understand the basic procedure of using SHARP before using SHARP for his/her own analysis. Both reference output and scripts are provided along with the test cases in order to verify correct installation and execution of the SHARP package. At the end of this manual, detailed instructions are provided on how to create a new test case so that user can perform novel multi-physics calculations with SHARP. Frequently asked questions are listed at the end of this manual to help the user to troubleshoot issues.« less

Characterization and multi-step transketolase-ω-transaminase bioconversions in an immobilized enzyme microreactor (IEMR) with packed tube.

PubMed

Halim, Amanatuzzakiah Abdul; Szita, Nicolas; Baganz, Frank

2013-12-01

The concept of de novo metabolic engineering through novel synthetic pathways offers new directions for multi-step enzymatic synthesis of complex molecules. This has been complemented by recent progress in performing enzymatic reactions using immobilized enzyme microreactors (IEMR). This work is concerned with the construction of de novo designed enzyme pathways in a microreactor synthesizing chiral molecules. An interesting compound, commonly used as the building block in several pharmaceutical syntheses, is a single diastereoisomer of 2-amino-1,3,4-butanetriol (ABT). This chiral amino alcohol can be synthesized from simple achiral substrates using two enzymes, transketolase (TK) and transaminase (TAm). Here we describe the development of an IEMR using His6-tagged TK and TAm immobilized onto Ni-NTA agarose beads and packed into tubes to enable multi-step enzyme reactions. The kinetic parameters of both enzymes were first determined using single IEMRs evaluated by a kinetic model developed for packed bed reactors. The Km(app) for both enzymes appeared to be flow rate dependent, while the turnover number kcat was reduced 3 fold compared to solution-phase TK and TAm reactions. For the multi-step enzyme reaction, single IEMRs were cascaded in series, whereby the first enzyme, TK, catalyzed a model reaction of lithium-hydroxypyruvate (HPA) and glycolaldehyde (GA) to L-erythrulose (ERY), and the second unit of the IEMR with immobilized TAm converted ERY into ABT using (S)-α-methylbenzylamine (MBA) as amine donor. With initial 60mM (HPA and GA each) and 6mM (MBA) substrate concentration mixture, the coupled reaction reached approximately 83% conversion in 20 min at the lowest flow rate. The ability to synthesize a chiral pharmaceutical intermediate, ABT in relatively short time proves this IEMR system as a powerful tool for construction and evaluation of de novo pathways as well as for determination of enzyme kinetics. Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

Alternative to Ritt's pseudodivision for finding the input-output equations of multi-output models.

PubMed

Meshkat, Nicolette; Anderson, Chris; DiStefano, Joseph J

2012-09-01

Differential algebra approaches to structural identifiability analysis of a dynamic system model in many instances heavily depend upon Ritt's pseudodivision at an early step in analysis. The pseudodivision algorithm is used to find the characteristic set, of which a subset, the input-output equations, is used for identifiability analysis. A simpler algorithm is proposed for this step, using Gröbner Bases, along with a proof of the method that includes a reduced upper bound on derivative requirements. Efficacy of the new algorithm is illustrated with several biosystem model examples. Copyright © 2012 Elsevier Inc. All rights reserved.

Understanding/Modelling of Thermal and Radiation Benefits of Quantum Dot Solar Cells

DTIC Science & Technology

2008-07-11

GaAs solar cells have been investigated. Strain compensation is a key step in realizing high- efficiency quantum dots solar cells (QDSC). InAs...factor. A strong correlation between the temperature dependent quantum dot electroluminescence peak emission wavelength and the sub-GaAs bandgap...increased efficiency and radiation resistance devices. The incorporation of quantum dots (QDs) into traditional single or multi-junction crystalline solar

The drivers of wildfire enlargement do not exhibit scale thresholds in southeastern Australian forests.

PubMed

Price, Owen F; Penman, Trent; Bradstock, Ross; Borah, Rittick

2016-10-01

Wildfires are complex adaptive systems, and have been hypothesized to exhibit scale-dependent transitions in the drivers of fire spread. Among other things, this makes the prediction of final fire size from conditions at the ignition difficult. We test this hypothesis by conducting a multi-scale statistical modelling of the factors determining whether fires reached 10 ha, then 100 ha then 1000 ha and the final size of fires >1000 ha. At each stage, the predictors were measures of weather, fuels, topography and fire suppression. The objectives were to identify differences among the models indicative of scale transitions, assess the accuracy of the multi-step method for predicting fire size (compared to predicting final size from initial conditions) and to quantify the importance of the predictors. The data were 1116 fires that occurred in the eucalypt forests of New South Wales between 1985 and 2010. The models were similar at the different scales, though there were subtle differences. For example, the presence of roads affected whether fires reached 10 ha but not larger scales. Weather was the most important predictor overall, though fuel load, topography and ease of suppression all showed effects. Overall, there was no evidence that fires have scale-dependent transitions in behaviour. The models had a predictive accuracy of 73%, 66%, 72% and 53% accuracy at 10 ha, 100 ha, 1000 ha and final size scales. When these steps were combined, the overall accuracy for predicting the size of fires was 62%, while the accuracy of the one step model was only 20%. Thus, the multi-scale approach was an improvement on the single scale approach, even though the predictive accuracy was probably insufficient for use as an operational tool. The analysis has also provided further evidence of the important role of weather, compared to fuel, suppression and topography in driving fire behaviour. Copyright © 2016. Published by Elsevier Ltd.

Dynamic implicit 3D adaptive mesh refinement for non-equilibrium radiation diffusion

NASA Astrophysics Data System (ADS)

Philip, B.; Wang, Z.; Berrill, M. A.; Birke, M.; Pernice, M.

2014-04-01

The time dependent non-equilibrium radiation diffusion equations are important for solving the transport of energy through radiation in optically thick regimes and find applications in several fields including astrophysics and inertial confinement fusion. The associated initial boundary value problems that are encountered often exhibit a wide range of scales in space and time and are extremely challenging to solve. To efficiently and accurately simulate these systems we describe our research on combining techniques that will also find use more broadly for long term time integration of nonlinear multi-physics systems: implicit time integration for efficient long term time integration of stiff multi-physics systems, local control theory based step size control to minimize the required global number of time steps while controlling accuracy, dynamic 3D adaptive mesh refinement (AMR) to minimize memory and computational costs, Jacobian Free Newton-Krylov methods on AMR grids for efficient nonlinear solution, and optimal multilevel preconditioner components that provide level independent solver convergence.

Statistical properties of multi-theta polymer chains

NASA Astrophysics Data System (ADS)

Uehara, Erica; Deguchi, Tetsuo

2018-04-01

We study statistical properties of polymer chains with complex structures whose chemical connectivities are expressed by graphs. The multi-theta curve of m subchains with two branch points connected by them is one of the simplest graphs among those graphs having closed paths, i.e. loops. We denoted it by θm , and for m  =  2 it is given by a ring. We derive analytically the pair distribution function and the scattering function for the θm -shaped polymer chains consisting of m Gaussian random walks of n steps. Surprisingly, it is shown rigorously that the mean-square radius of gyration for the Gaussian θm -shaped polymer chain does not depend on the number m of subchains if each subchain has the same fixed number of steps. For m  =  3 we show the Kratky plot for the theta-shaped polymer chain consisting of hard cylindrical segments by the Monte-Carlo method including reflection at trivalent vertices.

A ruthenium dimer complex with a flexible linker slowly threads between DNA bases in two distinct steps.

PubMed

Bahira, Meriem; McCauley, Micah J; Almaqwashi, Ali A; Lincoln, Per; Westerlund, Fredrik; Rouzina, Ioulia; Williams, Mark C

2015-10-15

Several multi-component DNA intercalating small molecules have been designed around ruthenium-based intercalating monomers to optimize DNA binding properties for therapeutic use. Here we probe the DNA binding ligand [μ-C4(cpdppz)2(phen)4Ru2](4+), which consists of two Ru(phen)2dppz(2+) moieties joined by a flexible linker. To quantify ligand binding, double-stranded DNA is stretched with optical tweezers and exposed to ligand under constant applied force. In contrast to other bis-intercalators, we find that ligand association is described by a two-step process, which consists of fast bimolecular intercalation of the first dppz moiety followed by ∼10-fold slower intercalation of the second dppz moiety. The second step is rate-limited by the requirement for a DNA-ligand conformational change that allows the flexible linker to pass through the DNA duplex. Based on our measured force-dependent binding rates and ligand-induced DNA elongation measurements, we are able to map out the energy landscape and structural dynamics for both ligand binding steps. In addition, we find that at zero force the overall binding process involves fast association (∼10 s), slow dissociation (∼300 s), and very high affinity (Kd ∼10 nM). The methodology developed in this work will be useful for studying the mechanism of DNA binding by other multi-step intercalating ligands and proteins. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

Adaptive multi-step Full Waveform Inversion based on Waveform Mode Decomposition

NASA Astrophysics Data System (ADS)

Hu, Yong; Han, Liguo; Xu, Zhuo; Zhang, Fengjiao; Zeng, Jingwen

2017-04-01

Full Waveform Inversion (FWI) can be used to build high resolution velocity models, but there are still many challenges in seismic field data processing. The most difficult problem is about how to recover long-wavelength components of subsurface velocity models when seismic data is lacking of low frequency information and without long-offsets. To solve this problem, we propose to use Waveform Mode Decomposition (WMD) method to reconstruct low frequency information for FWI to obtain a smooth model, so that the initial model dependence of FWI can be reduced. In this paper, we use adjoint-state method to calculate the gradient for Waveform Mode Decomposition Full Waveform Inversion (WMDFWI). Through the illustrative numerical examples, we proved that the low frequency which is reconstructed by WMD method is very reliable. WMDFWI in combination with the adaptive multi-step inversion strategy can obtain more faithful and accurate final inversion results. Numerical examples show that even if the initial velocity model is far from the true model and lacking of low frequency information, we still can obtain good inversion results with WMD method. From numerical examples of anti-noise test, we see that the adaptive multi-step inversion strategy for WMDFWI has strong ability to resist Gaussian noise. WMD method is promising to be able to implement for the land seismic FWI, because it can reconstruct the low frequency information, lower the dominant frequency in the adjoint source, and has a strong ability to resist noise.

The Multi-Step CADIS method for shutdown dose rate calculations and uncertainty propagation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ibrahim, Ahmad M.; Peplow, Douglas E.; Grove, Robert E.

2015-12-01

Shutdown dose rate (SDDR) analysis requires (a) a neutron transport calculation to estimate neutron flux fields, (b) an activation calculation to compute radionuclide inventories and associated photon sources, and (c) a photon transport calculation to estimate final SDDR. In some applications, accurate full-scale Monte Carlo (MC) SDDR simulations are needed for very large systems with massive amounts of shielding materials. However, these simulations are impractical because calculation of space- and energy-dependent neutron fluxes throughout the structural materials is needed to estimate distribution of radioisotopes causing the SDDR. Biasing the neutron MC calculation using an importance function is not simple becausemore » it is difficult to explicitly express the response function, which depends on subsequent computational steps. Furthermore, the typical SDDR calculations do not consider how uncertainties in MC neutron calculation impact SDDR uncertainty, even though MC neutron calculation uncertainties usually dominate SDDR uncertainty.« less

Multi-step routes of capuchin monkeys in a laser pointer traveling salesman task.

PubMed

Howard, Allison M; Fragaszy, Dorothy M

2014-09-01

Prior studies have claimed that nonhuman primates plan their routes multiple steps in advance. However, a recent reexamination of multi-step route planning in nonhuman primates indicated that there is no evidence for planning more than one step ahead. We tested multi-step route planning in capuchin monkeys using a pointing device to "travel" to distal targets while stationary. This device enabled us to determine whether capuchins distinguish the spatial relationship between goals and themselves and spatial relationships between goals and the laser dot, allocentrically. In Experiment 1, two subjects were presented with identical food items in Near-Far (one item nearer to subject) and Equidistant (both items equidistant from subject) conditions with a laser dot visible between the items. Subjects moved the laser dot to the items using a joystick. In the Near-Far condition, one subject demonstrated a bias for items closest to self but the other subject chose efficiently. In the second experiment, subjects retrieved three food items in similar Near-Far and Equidistant arrangements. Both subjects preferred food items nearest the laser dot and showed no evidence of multi-step route planning. We conclude that these capuchins do not make choices on the basis of multi-step look ahead strategies. © 2014 Wiley Periodicals, Inc.

Multi-objective optimization of process parameters of multi-step shaft formed with cross wedge rolling based on orthogonal test

NASA Astrophysics Data System (ADS)

Han, S. T.; Shu, X. D.; Shchukin, V.; Kozhevnikova, G.

2018-06-01

In order to achieve reasonable process parameters in forming multi-step shaft by cross wedge rolling, the research studied the rolling-forming process multi-step shaft on the DEFORM-3D finite element software. The interactive orthogonal experiment was used to study the effect of the eight parameters, the first section shrinkage rate φ1, the first forming angle α1, the first spreading angle β1, the first spreading length L1, the second section shrinkage rate φ2, the second forming angle α2, the second spreading angle β2 and the second spreading length L2, on the quality of shaft end and the microstructure uniformity. By using the fuzzy mathematics comprehensive evaluation method and the extreme difference analysis, the influence degree of the process parameters on the quality of the multi-step shaft is obtained: β2>φ2L1>α1>β1>φ1>α2L2. The results of the study can provide guidance for obtaining multi-stepped shaft with high mechanical properties and achieving near net forming without stub bar in cross wedge rolling.

Discovery of multi-ring basins - Gestalt perception in planetary science

NASA Technical Reports Server (NTRS)

Hartmann, W. K.

1981-01-01

Early selenographers resolved individual structural components of multi-ring basin systems but missed the underlying large-scale multi-ring basin patterns. The recognition of multi-ring basins as a general class of planetary features can be divided into five steps. Gilbert (1893) took a first step in recognizing radial 'sculpture' around the Imbrium basin system. Several writers through the 1940's rediscovered the radial sculpture and extended this concept by describing concentric rings around several circular maria. Some reminiscences are given about the fourth step - discovery of the Orientale basin and other basin systems by rectified lunar photography at the University of Arizona in 1961-62. Multi-ring basins remained a lunar phenomenon until the fifth step - discovery of similar systems of features on other planets, such as Mars (1972), Mercury (1974), and possibly Callisto and Ganymede (1979). This sequence is an example of gestalt recognition whose implications for scientific research are discussed.

Application of Toxicity Identification and Evaluation Procedures for Dredged Material Management

DTIC Science & Technology

2017-02-01

that may pose a risk to human health and the environment. The potential for risk ultimately depends on the final disposition of the dredged material... human health and ecological receptors. This information is also useful when evaluating dredged material for open water disposal since it could eliminate...and potential for exposure to humans or ecological receptors. The Inland Testing and Ocean Disposal Manuals establish a multi-step testing protocol

Single nucleotide polymorphisms and haplotypes associated with feed efficiency in beef cattle

PubMed Central

2013-01-01

Background General, breed- and diet-dependent associations between feed efficiency in beef cattle and single nucleotide polymorphisms (SNPs) or haplotypes were identified on a population of 1321 steers using a 50 K SNP panel. Genomic associations with traditional two-step indicators of feed efficiency – residual feed intake (RFI), residual average daily gain (RADG), and residual intake gain (RIG) – were compared to associations with two complementary one-step indicators of feed efficiency: efficiency of intake (EI) and efficiency of gain (EG). Associations uncovered in a training data set were evaluated on independent validation data set. A multi-SNP model was developed to predict feed efficiency. Functional analysis of genes harboring SNPs significantly associated with feed efficiency and network visualization aided in the interpretation of the results. Results For the five feed efficiency indicators, the numbers of general, breed-dependent, and diet-dependent associations with SNPs (P-value < 0.0001) were 31, 40, and 25, and with haplotypes were six, ten, and nine, respectively. Of these, 20 SNP and six haplotype associations overlapped between RFI and EI, and five SNP and one haplotype associations overlapped between RADG and EG. This result confirms the complementary value of the one and two-step indicators. The multi-SNP models included 89 SNPs and offered a precise prediction of the five feed efficiency indicators. The associations of 17 SNPs and 7 haplotypes with feed efficiency were confirmed on the validation data set. Nine clusters of Gene Ontology and KEGG pathway categories (mean P-value < 0.001) including, 9nucleotide binding; ion transport, phosphorous metabolic process, and the MAPK signaling pathway were overrepresented among the genes harboring the SNPs associated with feed efficiency. Conclusions The general SNP associations suggest that a single panel of genomic variants can be used regardless of breed and diet. The breed- and diet-dependent associations between SNPs and feed efficiency suggest that further refinement of variant panels require the consideration of the breed and management practices. The unique genomic variants associated with the one- and two-step indicators suggest that both types of indicators offer complementary description of feed efficiency that can be exploited for genome-enabled selection purposes. PMID:24066663

Impact of user influence on information multi-step communication in a micro-blog

NASA Astrophysics Data System (ADS)

Wu, Yue; Hu, Yong; He, Xiao-Hai; Deng, Ken

2014-06-01

User influence is generally considered as one of the most critical factors that affect information cascading spreading. Based on this common assumption, this paper proposes a theoretical model to examine user influence on the information multi-step communication in a micro-blog. The multi-steps of information communication are divided into first-step and non-first-step, and user influence is classified into five dimensions. Actual data from the Sina micro-blog is collected to construct the model by means of an approach based on structural equations that uses the Partial Least Squares (PLS) technique. Our experimental results indicate that the dimensions of the number of fans and their authority significantly impact the information of first-step communication. Leader rank has a positive impact on both first-step and non-first-step communication. Moreover, global centrality and weight of friends are positively related to the information non-first-step communication, but authority is found to have much less relation to it.

Surface Modified Particles By Multi-Step Michael-Type Addition And Process For The Preparation Thereof

DOEpatents

Cook, Ronald Lee; Elliott, Brian John; Luebben, Silvia DeVito; Myers, Andrew William; Smith, Bryan Matthew

2005-05-03

A new class of surface modified particles and a multi-step Michael-type addition surface modification process for the preparation of the same is provided. The multi-step Michael-type addition surface modification process involves two or more reactions to compatibilize particles with various host systems and/or to provide the particles with particular chemical reactivities. The initial step comprises the attachment of a small organic compound to the surface of the inorganic particle. The subsequent steps attach additional compounds to the previously attached organic compounds through reactive organic linking groups. Specifically, these reactive groups are activated carbon—carbon pi bonds and carbon and non-carbon nucleophiles that react via Michael or Michael-type additions.

Impact of multi-resolution analysis of artificial intelligence models inputs on multi-step ahead river flow forecasting

NASA Astrophysics Data System (ADS)

Badrzadeh, Honey; Sarukkalige, Ranjan; Jayawardena, A. W.

2013-12-01

Discrete wavelet transform was applied to decomposed ANN and ANFIS inputs.Novel approach of WNF with subtractive clustering applied for flow forecasting.Forecasting was performed in 1-5 step ahead, using multi-variate inputs.Forecasting accuracy of peak values and longer lead-time significantly improved.

Directivity pattern of the sound radiated from axisymmetric stepped plates.

PubMed

He, Xiping; Yan, Xiuli; Li, Na

2016-08-01

For the purpose of optimal design and efficient utilization of the kind of stepped plate radiator in air, in this contribution, an approach for calculation of the directivity pattern of the sound radiated from a stepped plate in flexural vibration with a free edge is developed based on Kirchhoff-Love hypothesis and Rayleigh integral principle. Experimental tests of directivity pattern for a fabricated flat plate and two fabricated plates with one and two step radiators were carried out. It shows that the configuration of the measured directivity patterns by the proposed analytic approach is similar to those of the calculated approach. Comparison of the agreement between the calculated directivity pattern of a stepped plate and its corresponding theoretical piston show that the former radiator is equivalent to the latter, and the diffraction field generated by the unbaffled upper surface may be small. It also shows that the directivity pattern of a stepped radiator is independent of the metallic material but dependent on the thickness of base plate and resonant frequency. The thicker the thickness of base plate, the more directive the radiation is. The proposed analytic approach in this work may be adopted for any other plates with multi-steps.

Efficient Multi-Stage Time Marching for Viscous Flows via Local Preconditioning

NASA Technical Reports Server (NTRS)

Kleb, William L.; Wood, William A.; vanLeer, Bram

1999-01-01

A new method has been developed to accelerate the convergence of explicit time-marching, laminar, Navier-Stokes codes through the combination of local preconditioning and multi-stage time marching optimization. Local preconditioning is a technique to modify the time-dependent equations so that all information moves or decays at nearly the same rate, thus relieving the stiffness for a system of equations. Multi-stage time marching can be optimized by modifying its coefficients to account for the presence of viscous terms, allowing larger time steps. We show it is possible to optimize the time marching scheme for a wide range of cell Reynolds numbers for the scalar advection-diffusion equation, and local preconditioning allows this optimization to be applied to the Navier-Stokes equations. Convergence acceleration of the new method is demonstrated through numerical experiments with circular advection and laminar boundary-layer flow over a flat plate.

Non-aqueous Electrode Processing and Construction of Lithium-ion Coin Cells.

PubMed

Stein, Malcolm; Chen, Chien-Fan; Robles, Daniel J; Rhodes, Christopher; Mukherjee, Partha P

2016-02-01

Research into new and improved materials to be utilized in lithium-ion batteries (LIB) necessitates an experimental counterpart to any computational analysis. Testing of lithium-ion batteries in an academic setting has taken on several forms, but at the most basic level lies the coin cell construction. In traditional LIB electrode preparation, a multi-phase slurry composed of active material, binder, and conductive additive is cast out onto a substrate. An electrode disc can then be punched from the dried sheet and used in the construction of a coin cell for electrochemical evaluation. Utilization of the potential of the active material in a battery is critically dependent on the microstructure of the electrode, as an appropriate distribution of the primary components are crucial to ensuring optimal electrical conductivity, porosity, and tortuosity, such that electrochemical and transport interaction is optimized. Processing steps ranging from the combination of dry powder, wet mixing, and drying can all critically affect multi-phase interactions that influence the microstructure formation. Electrochemical probing necessitates the construction of electrodes and coin cells with the utmost care and precision. This paper aims at providing a step-by-step guide of non-aqueous electrode processing and coin cell construction for lithium-ion batteries within an academic setting and with emphasis on deciphering the influence of drying and calendaring.

Non-aqueous Electrode Processing and Construction of Lithium-ion Coin Cells

PubMed Central

Stein, Malcolm; Chen, Chien-Fan; Robles, Daniel J.; Rhodes, Christopher; Mukherjee, Partha P.

2016-01-01

Research into new and improved materials to be utilized in lithium-ion batteries (LIB) necessitates an experimental counterpart to any computational analysis. Testing of lithium-ion batteries in an academic setting has taken on several forms, but at the most basic level lies the coin cell construction. In traditional LIB electrode preparation, a multi-phase slurry composed of active material, binder, and conductive additive is cast out onto a substrate. An electrode disc can then be punched from the dried sheet and used in the construction of a coin cell for electrochemical evaluation. Utilization of the potential of the active material in a battery is critically dependent on the microstructure of the electrode, as an appropriate distribution of the primary components are crucial to ensuring optimal electrical conductivity, porosity, and tortuosity, such that electrochemical and transport interaction is optimized. Processing steps ranging from the combination of dry powder, wet mixing, and drying can all critically affect multi-phase interactions that influence the microstructure formation. Electrochemical probing necessitates the construction of electrodes and coin cells with the utmost care and precision. This paper aims at providing a step-by-step guide of non-aqueous electrode processing and coin cell construction for lithium-ion batteries within an academic setting and with emphasis on deciphering the influence of drying and calendaring. PMID:26863503

A Conductometric Indium Oxide Semiconducting Nanoparticle Enzymatic Biosensor Array

PubMed Central

Lee, Dongjin; Ondrake, Janet; Cui, Tianhong

2011-01-01

We report a conductometric nanoparticle biosensor array to address the significant variation of electrical property in nanomaterial biosensors due to the random network nature of nanoparticle thin-film. Indium oxide and silica nanoparticles (SNP) are assembled selectively on the multi-site channel area of the resistors using layer-by-layer self-assembly. To demonstrate enzymatic biosensing capability, glucose oxidase is immobilized on the SNP layer for glucose detection. The packaged sensor chip onto a ceramic pin grid array is tested using syringe pump driven feed and multi-channel I–V measurement system. It is successfully demonstrated that glucose is detected in many different sensing sites within a chip, leading to concentration dependent currents. The sensitivity has been found to be dependent on the channel length of the resistor, 4–12 nA/mM for channel lengths of 5–20 μm, while the apparent Michaelis-Menten constant is 20 mM. By using sensor array, analytical data could be obtained with a single step of sample solution feeding. This work sheds light on the applicability of the developed nanoparticle microsensor array to multi-analyte sensors, novel bioassay platforms, and sensing components in a lab-on-a-chip. PMID:22163696

Shadowing effects on multi-step Langmuir probe array on HL-2A tokamak

NASA Astrophysics Data System (ADS)

Ke, R.; Xu, M.; Nie, L.; Gao, Z.; Wu, Y.; Yuan, B.; Chen, J.; Song, X.; Yan, L.; Duan, X.

2018-05-01

Multi-step Langmuir probe arrays have been designed and installed on the HL-2A tokamak [1]–[2] to study the turbulent transport in the edge plasma, especially for the measurement of poloidal momentum flux, Reynolds stress Rs. However, except the probe tips on the top step, all other tips on lower steps are shadowed by graphite skeleton. It is necessary to estimate the shadowing effects on equilibrium and fluctuation measurement. In this paper, comparison of shadowed tips to unshadowed ones is presented. The results show that shadowing can strongly reduce the ion and electron effective collection area. However, its effect is negligible for the turbulence intensity and coherence measurement, confirming that the multi-step LP array is proper for the turbulent transport measurement.

Efficient Machine Learning Approach for Optimizing Scientific Computing Applications on Emerging HPC Architectures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arumugam, Kamesh

Efficient parallel implementations of scientific applications on multi-core CPUs with accelerators such as GPUs and Xeon Phis is challenging. This requires - exploiting the data parallel architecture of the accelerator along with the vector pipelines of modern x86 CPU architectures, load balancing, and efficient memory transfer between different devices. It is relatively easy to meet these requirements for highly structured scientific applications. In contrast, a number of scientific and engineering applications are unstructured. Getting performance on accelerators for these applications is extremely challenging because many of these applications employ irregular algorithms which exhibit data-dependent control-ow and irregular memory accesses. Furthermore,more » these applications are often iterative with dependency between steps, and thus making it hard to parallelize across steps. As a result, parallelism in these applications is often limited to a single step. Numerical simulation of charged particles beam dynamics is one such application where the distribution of work and memory access pattern at each time step is irregular. Applications with these properties tend to present significant branch and memory divergence, load imbalance between different processor cores, and poor compute and memory utilization. Prior research on parallelizing such irregular applications have been focused around optimizing the irregular, data-dependent memory accesses and control-ow during a single step of the application independent of the other steps, with the assumption that these patterns are completely unpredictable. We observed that the structure of computation leading to control-ow divergence and irregular memory accesses in one step is similar to that in the next step. It is possible to predict this structure in the current step by observing the computation structure of previous steps. In this dissertation, we present novel machine learning based optimization techniques to address the parallel implementation challenges of such irregular applications on different HPC architectures. In particular, we use supervised learning to predict the computation structure and use it to address the control-ow and memory access irregularities in the parallel implementation of such applications on GPUs, Xeon Phis, and heterogeneous architectures composed of multi-core CPUs with GPUs or Xeon Phis. We use numerical simulation of charged particles beam dynamics simulation as a motivating example throughout the dissertation to present our new approach, though they should be equally applicable to a wide range of irregular applications. The machine learning approach presented here use predictive analytics and forecasting techniques to adaptively model and track the irregular memory access pattern at each time step of the simulation to anticipate the future memory access pattern. Access pattern forecasts can then be used to formulate optimization decisions during application execution which improves the performance of the application at a future time step based on the observations from earlier time steps. In heterogeneous architectures, forecasts can also be used to improve the memory performance and resource utilization of all the processing units to deliver a good aggregate performance. We used these optimization techniques and anticipation strategy to design a cache-aware, memory efficient parallel algorithm to address the irregularities in the parallel implementation of charged particles beam dynamics simulation on different HPC architectures. Experimental result using a diverse mix of HPC architectures shows that our approach in using anticipation strategy is effective in maximizing data reuse, ensuring workload balance, minimizing branch and memory divergence, and in improving resource utilization.« less

Tracking children's mental states while solving algebra equations.

PubMed

Anderson, John R; Betts, Shawn; Ferris, Jennifer L; Fincham, Jon M

2012-11-01

Behavioral and function magnetic resonance imagery (fMRI) data were combined to infer the mental states of students as they interacted with an intelligent tutoring system. Sixteen children interacted with a computer tutor for solving linear equations over a six-day period (days 0-5), with days 1 and 5 occurring in an fMRI scanner. Hidden Markov model algorithms combined a model of student behavior with multi-voxel imaging pattern data to predict the mental states of students. We separately assessed the algorithms' ability to predict which step in a problem-solving sequence was performed and whether the step was performed correctly. For day 1, the data patterns of other students were used to predict the mental states of a target student. These predictions were improved on day 5 by adding information about the target student's behavioral and imaging data from day 1. Successful tracking of mental states depended on using the combination of a behavioral model and multi-voxel pattern analysis, illustrating the effectiveness of an integrated approach to tracking the cognition of individuals in real time as they perform complex tasks. Copyright © 2011 Wiley Periodicals, Inc.

A numerical analysis of GeO2-doped multi-step index single-mode fiber for stimulated Brillouin scattering

NASA Astrophysics Data System (ADS)

Xiao, H.; Ren, G.; Dong, Y.; Li, H.; Xiao, S.; Wu, B.; Jian, S.

2018-06-01

A numerical analysis of a GeO2-doped single-mode optical fiber with a multi-step index core toward stimulated Brillouin scattering (SBS) based dual-parameter sensing applications is proposed. Adjusting the parameters in the fiber design, higher-order acoustic modes are sufficiently enhanced, making the fiber feasible for discriminative measurements of temperature and strain in the meantime. Numerical simulations indicate that the Brillouin frequency shifts and peak SBS efficiencies are strongly dependent on the doping concentration and the thickness of low-index ring in the proposed fiber. With appropriate structural and optical parameters, this fiber could support two distinct acoustic modes with comparable peak SBS efficiencies and well-spaced Brillouin frequency shifts. The sensing characteristics contributed by the dual-peak feature in the Brillouin gain spectrum are explored. Calculated accuracies of temperature and strain in simultaneous measurements can be up to 0.64 °C and 15.4 με, respectively. The proposed fiber might have potential applications for long-haul distributed dual-parameter simultaneous measurements.

Objectively Measured Patterns of Activities of Different Intensity Categories and Steps Taken Among Working Adults in a Multi-ethnic Asian Population.

PubMed

Müller-Riemenschneider, Falk; Ng, Sheryl Hui Xian; Koh, David; Chu, Anne Hin Yee

2016-06-01

To objectively assess sedentary behavior (SB), light- and moderate-to-vigorous intensity physical activity (MVPA), and steps among Singaporean office-based workers across days of the week. A convenience sample of office-based employees of a public University was recruited. Time spent for SB, light-, and MVPA using different validated accelerometry counts per minute (CPM), and step count were determined. Depending on applied CPM for SB (less than 100, less than 150 and less than 200 CPM), 107 working adults spent between 69.2% and 76.4% of their daily wakeful time in SB. Time spent in SB and MVPA were higher on weekdays than weekends. The hourly analysis highlights patterns of greater SB during usual working hours on weekdays but not on weekends. SB at work contributes greatly toward total daily sitting time. Low PA levels and high SB levels were found on weekends.

Distributed optimisation problem with communication delay and external disturbance

NASA Astrophysics Data System (ADS)

Tran, Ngoc-Tu; Xiao, Jiang-Wen; Wang, Yan-Wu; Yang, Wu

2017-12-01

This paper investigates the distributed optimisation problem for the multi-agent systems (MASs) with the simultaneous presence of external disturbance and the communication delay. To solve this problem, a two-step design scheme is introduced. In the first step, based on the internal model principle, the internal model term is constructed to compensate the disturbance asymptotically. In the second step, a distributed optimisation algorithm is designed to solve the distributed optimisation problem based on the MASs with the simultaneous presence of disturbance and communication delay. Moreover, in the proposed algorithm, each agent interacts with its neighbours through the connected topology and the delay occurs during the information exchange. By utilising Lyapunov-Krasovskii functional, the delay-dependent conditions are derived for both slowly and fast time-varying delay, respectively, to ensure the convergence of the algorithm to the optimal solution of the optimisation problem. Several numerical simulation examples are provided to illustrate the effectiveness of the theoretical results.

[Safety culture: definition, models and design].

PubMed

Pfaff, Holger; Hammer, Antje; Ernstmann, Nicole; Kowalski, Christoph; Ommen, Oliver

2009-01-01

Safety culture is a multi-dimensional phenomenon. Safety culture of a healthcare organization is high if it has a common stock in knowledge, values and symbols in regard to patients' safety. The article intends to define safety culture in the first step and, in the second step, demonstrate the effects of safety culture. We present the model of safety behaviour and show how safety culture can affect behaviour and produce safe behaviour. In the third step we will look at the causes of safety culture and present the safety-culture-model. The main hypothesis of this model is that the safety culture of a healthcare organization strongly depends on its communication culture and its social capital. Finally, we will investigate how the safety culture of a healthcare organization can be improved. Based on the safety culture model six measures to improve safety culture will be presented.

Ultra-fast consensus of discrete-time multi-agent systems with multi-step predictive output feedback

NASA Astrophysics Data System (ADS)

Zhang, Wenle; Liu, Jianchang

2016-04-01

This article addresses the ultra-fast consensus problem of high-order discrete-time multi-agent systems based on a unified consensus framework. A novel multi-step predictive output mechanism is proposed under a directed communication topology containing a spanning tree. By predicting the outputs of a network several steps ahead and adding this information into the consensus protocol, it is shown that the asymptotic convergence factor is improved by a power of q + 1 compared to the routine consensus. The difficult problem of selecting the optimal control gain is solved well by introducing a variable called convergence step. In addition, the ultra-fast formation achievement is studied on the basis of this new consensus protocol. Finally, the ultra-fast consensus with respect to a reference model and robust consensus is discussed. Some simulations are performed to illustrate the effectiveness of the theoretical results.

Resolution of singularities for multi-loop integrals

NASA Astrophysics Data System (ADS)

Bogner, Christian; Weinzierl, Stefan

2008-04-01

We report on a program for the numerical evaluation of divergent multi-loop integrals. The program is based on iterated sector decomposition. We improve the original algorithm of Binoth and Heinrich such that the program is guaranteed to terminate. The program can be used to compute numerically the Laurent expansion of divergent multi-loop integrals regulated by dimensional regularisation. The symbolic and the numerical steps of the algorithm are combined into one program. Program summaryProgram title: sector_decomposition Catalogue identifier: AEAG_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEAG_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 47 506 No. of bytes in distributed program, including test data, etc.: 328 485 Distribution format: tar.gz Programming language: C++ Computer: all Operating system: Unix RAM: Depending on the complexity of the problem Classification: 4.4 External routines: GiNaC, available from http://www.ginac.de, GNU scientific library, available from http://www.gnu.org/software/gsl Nature of problem: Computation of divergent multi-loop integrals. Solution method: Sector decomposition. Restrictions: Only limited by the available memory and CPU time. Running time: Depending on the complexity of the problem.

Multi-off-grid methods in multi-step integration of ordinary differential equations

NASA Technical Reports Server (NTRS)

Beaudet, P. R.

1974-01-01

Description of methods of solving first- and second-order systems of differential equations in which all derivatives are evaluated at off-grid locations in order to circumvent the Dahlquist stability limitation on the order of on-grid methods. The proposed multi-off-grid methods require off-grid state predictors for the evaluation of the n derivatives at each step. Progressing forward in time, the off-grid states are predicted using a linear combination of back on-grid state values and off-grid derivative evaluations. A comparison is made between the proposed multi-off-grid methods and the corresponding Adams and Cowell on-grid integration techniques in integrating systems of ordinary differential equations, showing a significant reduction in the error at larger step sizes in the case of the multi-off-grid integrator.

Real-time forecasts of tomorrow's earthquakes in California: a new mapping tool

USGS Publications Warehouse

Gerstenberger, Matt; Wiemer, Stefan; Jones, Lucy

2004-01-01

We have derived a multi-model approach to calculate time-dependent earthquake hazard resulting from earthquake clustering. This file report explains the theoretical background behind the approach, the specific details that are used in applying the method to California, as well as the statistical testing to validate the technique. We have implemented our algorithm as a real-time tool that has been automatically generating short-term hazard maps for California since May of 2002, at http://step.wr.usgs.gov

Real-Time Visualization of an HPF-based CFD Simulation

NASA Technical Reports Server (NTRS)

Kremenetsky, Mark; Vaziri, Arsi; Haimes, Robert; Chancellor, Marisa K. (Technical Monitor)

1996-01-01

Current time-dependent CFD simulations produce very large multi-dimensional data sets at each time step. The visual analysis of computational results are traditionally performed by post processing the static data on graphics workstations. We present results from an alternate approach in which we analyze the simulation data in situ on each processing node at the time of simulation. The locally analyzed results, usually more economical and in a reduced form, are then combined and sent back for visualization on a graphics workstation.

Multi-step Monte Carlo calculations applied to nuclear reactor instrumentation - source definition and renormalization to physical values

DOE Office of Scientific and Technical Information (OSTI.GOV)

Radulovic, Vladimir; Barbot, Loic; Fourmentel, Damien

Significant efforts have been made over the last few years in the French Alternative Energies and Atomic Energy Commission (CEA) to adopt multi-step Monte Carlo calculation schemes in the investigation and interpretation of the response of nuclear reactor instrumentation detectors (e.g. miniature ionization chambers - MICs and self-powered neutron or gamma detectors - SPNDs and SPGDs). The first step consists of the calculation of the primary data, i.e. evaluation of the neutron and gamma flux levels and spectra in the environment where the detector is located, using a computational model of the complete nuclear reactor core and its surroundings. Thesemore » data are subsequently used to define sources for the following calculation steps, in which only a model of the detector under investigation is used. This approach enables calculations with satisfactory statistical uncertainties (of the order of a few %) within regions which are very small in size (the typical volume of which is of the order of 1 mm{sup 3}). The main drawback of a calculation scheme as described above is that perturbation effects on the radiation conditions caused by the detectors themselves are not taken into account. Depending on the detector, the nuclear reactor and the irradiation position, the perturbation in the neutron flux as primary data may reach 10 to 20%. A further issue is whether the model used in the second step calculations yields physically representative results. This is generally not the case, as significant deviations may arise, depending on the source definition. In particular, as presented in the paper, the injudicious use of special options aimed at increasing the computation efficiency (e.g. reflective boundary conditions) may introduce unphysical bias in the calculated flux levels and distortions in the spectral shapes. This paper presents examples of the issues described above related to a case study on the interpretation of the signal from different types of SPNDs, which were recently irradiated in the Jozef Stefan Institute TRIGA Mark II reactor in Ljubljana, Slovenia, and provides recommendations on how they can be overcome. The paper concludes with a discussion on the renormalization of the results from the second step calculations, to obtain accurate physical values. (authors)« less

Multi-step prediction for influenza outbreak by an adjusted long short-term memory.

PubMed

Zhang, J; Nawata, K

2018-05-01

Influenza results in approximately 3-5 million annual cases of severe illness and 250 000-500 000 deaths. We urgently need an accurate multi-step-ahead time-series forecasting model to help hospitals to perform dynamical assignments of beds to influenza patients for the annually varied influenza season, and aid pharmaceutical companies to formulate a flexible plan of manufacturing vaccine for the yearly different influenza vaccine. In this study, we utilised four different multi-step prediction algorithms in the long short-term memory (LSTM). The result showed that implementing multiple single-output prediction in a six-layer LSTM structure achieved the best accuracy. The mean absolute percentage errors from two- to 13-step-ahead prediction for the US influenza-like illness rates were all <15%, averagely 12.930%. To the best of our knowledge, it is the first time that LSTM has been applied and refined to perform multi-step-ahead prediction for influenza outbreaks. Hopefully, this modelling methodology can be applied in other countries and therefore help prevent and control influenza worldwide.

Effects of low energy E-beam irradiation on graphene and graphene field effect transistors and raman metrology of graphene on split gate test structures

NASA Astrophysics Data System (ADS)

Rao, Gayathri S.

2011-12-01

Apart from its compelling performance in conventional nanoelectronic device geometries, graphene is an appropriate candidate to study certain interesting phenomenon (e.g. the Veselago lens effect) predicted on the basis of its linear electron dispersion relation. A key requirement for the observation of such phenomenon in graphene and for its use in conventional field-effect transistor (FET) devices is the need to minimize defects such as consisting of -- or resulting from -- adsorbates and lattice non-uniformities, and reduce deleterious substrate effects. Consequently the investigation of the origin and interaction of defects in the graphene lattice is essential to improve and tailor graphene-based device performance. In this thesis, optical spectroscopic studies on the influence of low-energy electron irradiation on adsorbate-induced defectivity and doping for substrate supported and suspended graphene were carried out along with spectroscopic and transport measurements on graphene FETs. A comparative investigation of the effects of single-step versus multi-step, low-energy electron irradiation (500 eV) on suspended, substrate supported graphene and on graphene FETs is reported. E-beam irradiation (single-step and multi-step) of substrate-supported graphene resulted in an increase in the Raman ID/IG ratio largely from hydrogenation due to radiolysis of the interfacial water layer between the graphene and the SiO2 substrate and from irradiated surface adsorbates. GFETs subjected to single and multi-step irradiation showed n-doping from CNP (charge neutrality point) shift of ˜ -8 and ˜ -16 V respectively. Correlation of this data with Raman analysis of suspended and supported graphene samples implied a strong role of the substrate and irradiation sequence in determining the level of doping. A correspondingly higher reduction in mobility per incident electron was also observed for GFETs subjected to multi-step irradiation compared to single step, in line with measured Raman ID/IG ratios. Additionally, the Raman G-band DeltaFWHM variation was strongly dependent on the nature of the e-beam irradiation and the presence of the substrate. Single-step irradiated, substrate-supported graphene exhibited substantial broadening while multi-step irradiation resulted in G-band narrowing. This behavior was not observed for suspended graphene which indicated the addition or elimination of substrate-induced phonon-relaxation mechanisms in response to each type of irradiation. The narrowing of the FWHM (G) in the multi-step case is attributed to doping consistent with the Dirac point shift of ˜ -16V and the removal of Landau phonon damping above Ef > ℏwG2 . In strong contrast, single step irradiation of substrate supported graphene yielded a broadening of the FWHM (G) accompanied by a CNP shift of ˜ -8V indicating appreciable n-doping. This reveals the presence of alternate phonon decay channels even when Landau damping above Ef > ℏwG2 is removed. It is proposed in this dissertation that this phenomenon is linked to hybridization of silicon oxide defect states (induced by single-step e-beam irradiation) and graphene electron states. This hybridization promotes a graphene phonon decay channel distinct from Landau damping, the latter being forbidden under sufficient doping. It is proposed that the alternate phonon decay channel involves two-component inelastic scattering, wherein the graphene phonons transfer energy to the carriers in the lattice which in turn couple to the polar phonons of the substrate resulting in mobility reduction. Furthermore, it is proposed that this defect-induced, graphene phonon decay channel is inhibited in multi-step e-beam irradiation due to the presence of adsorbates on the graphene introduced during ambient exposure between radiation cycles. On e-beam irradiation the adsorbates induce polar orientation of water dipoles at the graphene/SiO2 interface. This polar layer shifts the hybridized defect bands closer to the graphene Dirac bands thereby reducing the inelastic scattering and inhibiting the phonon decay medicated by SiO2 surface polar phonons (SPP). This model also explains the enhancement of n-type doping in GFETS observed for multi-step irradiation. These results highlight the impact of substrate defects and interaction of induced defectivity with the e-beam along with the role of interfacial water in impacting graphene device performance. The thesis also presents data on Raman-based characterization of graphene including layer number determination and carrier concentration measurement. Determination of layer number for graphene exfoliates focused on the splitting of the 2D Raman band. In addition, an alternate Raman-based thickness metrology was evaluated for CVD-based, polycrystalline graphene. Both were carried out on split gate test structures as a method for monolayer or bilayer confirmation in device geometries. In addition, carrier concentration measurements of exfoliates on 300nm SiO2 and split-gate test structure substrate have also been characterized with back gate biasing. These measurements made use of the stiffening of the Raman G-band with doping and the narrowing of the G-band FWHM. These results were important for validating conclusions from the e-beam irradiation experiments mentioned above regarding carrier doping.

Measurement of intrahepatic pressure during radiofrequency ablation in porcine liver.

PubMed

Kawamoto, Chiaki; Yamauchi, Atsushi; Baba, Yoko; Kaneko, Keiko; Yakabi, Koji

2010-04-01

To identify the most effective procedures to avoid increased intrahepatic pressure during radiofrequency ablation, we evaluated different ablation methods. Laparotomy was performed in 19 pigs. Intrahepatic pressure was monitored using an invasive blood pressure monitor. Radiofrequency ablation was performed as follows: single-step standard ablation; single-step at 30 W; single-step at 70 W; 4-step at 30 W; 8-step at 30 W; 8-step at 70 W; and cooled-tip. The array was fully deployed in single-step methods. In the multi-step methods, the array was gradually deployed in four or eight steps. With the cooled-tip, ablation was performed by increasing output by 10 W/min, starting at 40 W. Intrahepatic pressure was as follows: single-step standard ablation, 154.5 +/- 30.9 mmHg; single-step at 30 W, 34.2 +/- 20.0 mmHg; single-step at 70 W, 46.7 +/- 24.3 mmHg; 4-step at 30 W, 42.3 +/- 17.9 mmHg; 8-step at 30 W, 24.1 +/- 18.2 mmHg; 8-step at 70 W, 47.5 +/- 31.5 mmHg; and cooled-tip, 114.5 +/- 16.6 mmHg. The radiofrequency ablation-induced area was spherical with single-step standard ablation, 4-step at 30 W, and 8-step at 30 W. Conversely, the ablated area was irregular with single-step at 30 W, single-step at 70 W, and 8-step at 70 W. The ablation time was significantly shorter for the multi-step method than for the single-step method. Increased intrahepatic pressure could be controlled using multi-step methods. From the shapes of the ablation area, 30-W 8-step expansions appear to be most suitable for radiofrequency ablation.

Enhanced sensitivity of self-assembled-monolayer-based SPR immunosensor for detection of benzaldehyde using a single-step multi-sandwich immunoassay.

PubMed

Gobi, K Vengatajalabathy; Matsumoto, Kiyoshi; Toko, Kiyoshi; Ikezaki, Hidekazu; Miura, Norio

2007-04-01

This paper describes the fabrication and sensing characteristics of a self-assembled monolayer (SAM)-based surface plasmon resonance (SPR) immunosensor for detection of benzaldehyde (BZ). The functional sensing surface was fabricated by the immobilization of a benzaldehyde-ovalbumin conjugate (BZ-OVA) on Au-thiolate SAMs containing carboxyl end groups. Covalent binding of BZ-OVA on SAM was found to be dependent on the composition of the base SAM, and it is improved very much with the use of a mixed monolayer strategy. Based on SPR angle measurements, the functional sensor surface is established as a compact monolayer of BZ-OVA bound on the mixed SAM. The BZ-OVA-bound sensor surface undergoes immunoaffinity binding with anti-benzaldehyde antibody (BZ-Ab) selectively. An indirect inhibition immunoassay principle has been applied, in which analyte benzaldehyde solution was incubated with an optimal concentration of BZ-Ab for 5 min and injected over the sensor chip. Analyte benzaldehyde undergoes immunoreaction with BZ-Ab and makes it inactive for binding to BZ-OVA on the sensor chip. As a result, the SPR angle response decreases with an increase in the concentration of benzaldehyde. The fabricated immunosensor demonstrates a low detection limit (LDL) of 50 ppt (pg mL(-1)) with a response time of 5 min. Antibodies bound to the sensor chip during an immunoassay could be detached by a brief exposure to acidic pepsin. With this surface regeneration, reusability of the same sensor chip for as many as 30 determination cycles has been established. Sensitivity has been enhanced further with the application of an additional single-step multi-sandwich immunoassay step, in which the BZ-Ab bound to the sensor chip was treated with a mixture of biotin-labeled secondary antibody, streptavidin and biotin-bovine serum albumin (Bio-BSA) conjugate. With this approach, the SPR sensor signal increased by ca. 12 times and the low detection limit improved to 5 ppt with a total response time of no more than ca. 10 min. Figure A single-step multi-sandwich immunoassay step increases SPR sensor signal by ca. 12 times affording a low detection limit for benzaldehyde of 5 ppt.

Modulation format dependence of digital nonlinearity compensation performance in optical fibre communication systems.

PubMed

Xu, Tianhua; Shevchenko, Nikita A; Lavery, Domaniç; Semrau, Daniel; Liga, Gabriele; Alvarado, Alex; Killey, Robert I; Bayvel, Polina

2017-02-20

The relationship between modulation format and the performance of multi-channel digital back-propagation (MC-DBP) in ideal Nyquist-spaced optical communication systems is investigated. It is found that the nonlinear distortions behave independent of modulation format in the case of full-field DBP, in contrast to the cases of electronic dispersion compensation and partial-bandwidth DBP. It is shown that the minimum number of steps per span required for MC-DBP depends on the chosen modulation format. For any given target information rate, there exists a possible trade-off between modulation format and back-propagated bandwidth, which could be used to reduce the computational complexity requirement of MC-DBP.

A new fossil peccary from the Pleistocene-Holocene boundary of the eastern Yucatán Peninsula, Mexico

NASA Astrophysics Data System (ADS)

Stinnesbeck, Sarah R.; Frey, Eberhard; Stinnesbeck, Wolfgang; Avíles Olguín, Jeronimo; Zell, Patrick; Terrazas Mata, Alejandro; Benavente Sanvicente, Martha; González González, Arturo; Rojas Sandoval, Carmen; Acevez Nuñez, Eugenio

2017-08-01

Here we describe the left mandibular ramus of a fossil peccary from the submerged karst cave system in the southeastern Mexican state of Quintana Roo. The specimen, which was discovered in the Muknal cave northwest of Tulúm, is a new genus and species of peccary termed Muknalia minima. The taxon likely dates from the latest Pleistocene and differs significantly from all extant peccaries and their Pleistocene relatives by a concave notch at the caudal edge of the mandibular ramus and prominent ventrally directed angular process. These diagnostic osteological differences suggest that the masticatory apparatus differed from all other peccaries, which may hint to an ecological isolation on the late Pleistocene Yucatán Peninsula.

[Molecular marker mapping of the gene resistant to common bunt transferred from Aegilops cylindrica into bread wheat].

PubMed

Galaev, A V; Babaiants, L T; Sivolap, Iu M

2006-01-01

Introgression lines 5/55-91 and 378/2000 of bread wheat contain the gene of resistance to Tilletia caries (DC.) Tul. transferred from Aegilops cylindrica Host. Using bulked segregant analysis with ISSR and SSR PCR the lincage of microsatellite locus Xgwm 259 with the gene of common bunt resistance has been identified in F2 population of 378/2000 x Lutestens 23397. DNA mapping made it possible to localize this highly effective gene in the intercalary region of the long arm of wheat chromosome 1B at the distance of 7.6-8.5 cM of the microsatellite Xgwm 259 locus which thus can be used in wheat breeding for selection of genotype resistance to common bunt.

A transition from using multi-step procedures to a fully integrated system for performing extracorporeal photopheresis: A comparison of costs and efficiencies.

PubMed

Azar, Nabih; Leblond, Veronique; Ouzegdouh, Maya; Button, Paul

2017-12-01

The Pitié Salpêtrière Hospital Hemobiotherapy Department, Paris, France, has been providing extracorporeal photopheresis (ECP) since November 2011, and started using the Therakos ® CELLEX ® fully integrated system in 2012. This report summarizes our single-center experience of transitioning from the use of multi-step ECP procedures to the fully integrated ECP system, considering the capacity and cost implications. The total number of ECP procedures performed 2011-2015 was derived from department records. The time taken to complete a single ECP treatment using a multi-step technique and the fully integrated system at our department was assessed. Resource costs (2014€) were obtained for materials and calculated for personnel time required. Time-driven activity-based costing methods were applied to provide a cost comparison. The number of ECP treatments per year increased from 225 (2012) to 727 (2015). The single multi-step procedure took 270 min compared to 120 min for the fully integrated system. The total calculated per-session cost of performing ECP using the multi-step procedure was greater than with the CELLEX ® system (€1,429.37 and €1,264.70 per treatment, respectively). For hospitals considering a transition from multi-step procedures to fully integrated methods for ECP where cost may be a barrier, time-driven activity-based costing should be utilized to gain a more comprehensive understanding the full benefit that such a transition offers. The example from our department confirmed that there were not just cost and time savings, but that the time efficiencies gained with CELLEX ® allow for more patient treatments per year. © 2017 The Authors Journal of Clinical Apheresis Published by Wiley Periodicals, Inc.

Dissolvable fluidic time delays for programming multi-step assays in instrument-free paper diagnostics.

PubMed

Lutz, Barry; Liang, Tinny; Fu, Elain; Ramachandran, Sujatha; Kauffman, Peter; Yager, Paul

2013-07-21

Lateral flow tests (LFTs) are an ingenious format for rapid and easy-to-use diagnostics, but they are fundamentally limited to assay chemistries that can be reduced to a single chemical step. In contrast, most laboratory diagnostic assays rely on multiple timed steps carried out by a human or a machine. Here, we use dissolvable sugar applied to paper to create programmable flow delays and present a paper network topology that uses these time delays to program automated multi-step fluidic protocols. Solutions of sucrose at different concentrations (10-70% of saturation) were added to paper strips and dried to create fluidic time delays spanning minutes to nearly an hour. A simple folding card format employing sugar delays was shown to automate a four-step fluidic process initiated by a single user activation step (folding the card); this device was used to perform a signal-amplified sandwich immunoassay for a diagnostic biomarker for malaria. The cards are capable of automating multi-step assay protocols normally used in laboratories, but in a rapid, low-cost, and easy-to-use format.

Dissolvable fluidic time delays for programming multi-step assays in instrument-free paper diagnostics

PubMed Central

Lutz, Barry; Liang, Tinny; Fu, Elain; Ramachandran, Sujatha; Kauffman, Peter; Yager, Paul

2013-01-01

Lateral flow tests (LFTs) are an ingenious format for rapid and easy-to-use diagnostics, but they are fundamentally limited to assay chemistries that can be reduced to a single chemical step. In contrast, most laboratory diagnostic assays rely on multiple timed steps carried out by a human or a machine. Here, we use dissolvable sugar applied to paper to create programmable flow delays and present a paper network topology that uses these time delays to program automated multi-step fluidic protocols. Solutions of sucrose at different concentrations (10-70% of saturation) were added to paper strips and dried to create fluidic time delays spanning minutes to nearly an hour. A simple folding card format employing sugar delays was shown to automate a four-step fluidic process initiated by a single user activation step (folding the card); this device was used to perform a signal-amplified sandwich immunoassay for a diagnostic biomarker for malaria. The cards are capable of automating multi-step assay protocols normally used in laboratories, but in a rapid, low-cost, and easy-to-use format. PMID:23685876

The design of a multi-harmonic step-tunable gyrotron

NASA Astrophysics Data System (ADS)

Qi, Xiang-Bo; Du, Chao-Hai; Zhu, Juan-Feng; Pan, Shi; Liu, Pu-Kun

2017-03-01

The theoretical study of a step-tunable gyrotron controlled by successive excitation of multi-harmonic modes is presented in this paper. An axis-encircling electron beam is employed to eliminate the harmonic mode competition. Physics images are depicted to elaborate the multi-harmonic interaction mechanism in determining the operating parameters at which arbitrary harmonic tuning can be realized by magnetic field sweeping to achieve controlled multiband frequencies' radiation. An important principle is revealed that a weak coupling coefficient under a high-harmonic interaction can be compensated by a high Q-factor. To some extent, the complementation between the high Q-factor and weak coupling coefficient makes the high-harmonic mode potential to achieve high efficiency. Based on a previous optimized magnetic cusp gun, the multi-harmonic step-tunable gyrotron is feasible by using harmonic tuning of first-to-fourth harmonic modes. Multimode simulation shows that the multi-harmonic gyrotron can operate on the 34 GHz first-harmonic TE11 mode, 54 GHz second-harmonic TE21 mode, 74 GHz third-harmonic TE31 mode, and 94 GHz fourth-harmonic TE41 mode, corresponding to peak efficiencies of 28.6%, 35.7%, 17.1%, and 11.4%, respectively. The multi-harmonic step-tunable gyrotron provides new possibilities in millimeter-terahertz source development especially for advanced terahertz applications.

Improved perovskite phototransistor prepared using multi-step annealing method

NASA Astrophysics Data System (ADS)

Cao, Mingxuan; Zhang, Yating; Yu, Yu; Yao, Jianquan

2018-02-01

Organic-inorganic hybrid perovskites with good intrinsic physical properties have received substantial interest for solar cell and optoelectronic applications. However, perovskite film always suffers from a low carrier mobility due to its structural imperfection including sharp grain boundaries and pinholes, restricting their device performance and application potential. Here we demonstrate a straightforward strategy based on multi-step annealing process to improve the performance of perovskite photodetector. Annealing temperature and duration greatly affects the surface morphology and optoelectrical properties of perovskites which determines the device property of phototransistor. The perovskite films treated with multi-step annealing method tend to form highly uniform, well-crystallized and high surface coverage perovskite film, which exhibit stronger ultraviolet-visible absorption and photoluminescence spectrum compare to the perovskites prepared by conventional one-step annealing process. The field-effect mobilities of perovskite photodetector treated by one-step direct annealing method shows mobility as 0.121 (0.062) cm2V-1s-1 for holes (electrons), which increases to 1.01 (0.54) cm2V-1s-1 for that treated with muti-step slow annealing method. Moreover, the perovskite phototransistors exhibit a fast photoresponse speed of 78 μs. In general, this work focuses on the influence of annealing methods on perovskite phototransistor, instead of obtains best parameters of it. These findings prove that Multi-step annealing methods is feasible to prepared high performance based photodetector.

A Multi-stage Carcinogenesis Model to Investigate Caloric Restriction as a Potential Tool for Post-irradiation Mitigation of Cancer Risk

PubMed Central

Tani, Shusuke; Blyth, Benjamin John; Shang, Yi; Morioka, Takamitsu; Kakinuma, Shizuko; Shimada, Yoshiya

2016-01-01

The risk of radiation-induced cancer adds to anxiety in low-dose exposed populations. Safe and effective lifestyle changes which can help mitigate excess cancer risk might provide exposed individuals the opportunity to pro-actively reduce their cancer risk, and improve mental health and well-being. Here, we applied a mathematical multi-stage carcinogenesis model to the mouse lifespan data using adult-onset caloric restriction following irradiation in early life. We re-evaluated autopsy records with a veterinary pathologist to determine which tumors were the probable causes of death in order to calculate age-specific mortality. The model revealed that in both irradiated and unirradiated mice, caloric restriction reduced the age-specific mortality of all solid tumors and hepatocellular carcinomas across most of the lifespan, with the mortality rate dependent more on age owing to an increase in the number of predicted rate-limiting steps. Conversely, irradiation did not significantly alter the number of steps, but did increase the overall transition rate between the steps. We show that the extent of the protective effect of caloric restriction is independent of the induction of cancer from radiation exposure, and discuss future avenues of research to explore the utility of caloric restriction as an example of a potential post-irradiation mitigation strategy. PMID:27390741

Controlling charge transport mechanisms in molecular junctions: Distilling thermally induced hopping from coherent-resonant conduction.

PubMed

Kim, Hyehwang; Segal, Dvira

2017-04-28

The electrical conductance of molecular junctions may depend strongly on the temperature and weakly on molecular length, under two distinct mechanisms: phase-coherent resonant conduction, with charges proceeding via delocalized molecular orbitals, and incoherent thermally assisted multi-step hopping. While in the case of coherent conduction, the temperature dependence arises from the broadening of the Fermi distribution in the metal electrodes, in the latter case it corresponds to electron-vibration interaction effects on the junction. With the objective to distill the thermally activated hopping component, thus exposing intrinsic electron-vibration interaction phenomena on the junction, we suggest the design of molecular junctions with "spacers," extended anchoring groups that act to filter out phase-coherent resonant electrons. Specifically, we study the electrical conductance of fixed-gap and variable-gap junctions that include a tunneling block, with spacers at the boundaries. Using numerical simulations and analytical considerations, we demonstrate that in our design, resonant conduction is suppressed. As a result, the electrical conductance is dominated by two (rather than three) mechanisms: superexchange (deep tunneling) and multi-step thermally induced hopping. We further exemplify our analysis on DNA junctions with an A:T block serving as a tunneling barrier. Here, we show that the electrical conductance is insensitive to the number of G:C base-pairs at the boundaries. This indicates that the tunneling-to-hopping crossover revealed in such sequences truly corresponds to the properties of the A:T barrier.

Transient multi-physics analysis of a magnetorheological shock absorber with the inverse Jiles-Atherton hysteresis model

NASA Astrophysics Data System (ADS)

Zheng, Jiajia; Li, Yancheng; Li, Zhaochun; Wang, Jiong

2015-10-01

This paper presents multi-physics modeling of an MR absorber considering the magnetic hysteresis to capture the nonlinear relationship between the applied current and the generated force under impact loading. The magnetic field, temperature field, and fluid dynamics are represented by the Maxwell equations, conjugate heat transfer equations, and Navier-Stokes equations. These fields are coupled through the apparent viscosity and the magnetic force, both of which in turn depend on the magnetic flux density and the temperature. Based on a parametric study, an inverse Jiles-Atherton hysteresis model is used and implemented for the magnetic field simulation. The temperature rise of the MR fluid in the annular gap caused by core loss (i.e. eddy current loss and hysteresis loss) and fluid motion is computed to investigate the current-force behavior. A group of impulsive tests was performed for the manufactured MR absorber with step exciting currents. The numerical and experimental results showed good agreement, which validates the effectiveness of the proposed multi-physics FEA model.

Optical pattern recognition algorithms on neural-logic equivalent models and demonstration of their prospects and possible implementations

NASA Astrophysics Data System (ADS)

Krasilenko, Vladimir G.; Nikolsky, Alexander I.; Zaitsev, Alexandr V.; Voloshin, Victor M.

2001-03-01

Historic information regarding the appearance and creation of fundamentals of algebra-logical apparatus-`equivalental algebra' for description of neuro-nets paradigms and algorithms is considered which is unification of theory of neuron nets (NN), linear algebra and the most generalized neuro-biology extended for matrix case. A survey is given of `equivalental models' of neuron nets and associative memory is suggested new, modified matrix-tenzor neurological equivalental models (MTNLEMS) are offered with double adaptive-equivalental weighing (DAEW) for spatial-non- invariant recognition (SNIR) and space-invariant recognition (SIR) of 2D images (patterns). It is shown, that MTNLEMS DAEW are the most generalized, they can describe the processes in NN both within the frames of known paradigms and within new `equivalental' paradigm of non-interaction type, and the computing process in NN under using the offered MTNLEMs DAEW is reduced to two-step and multi-step algorithms and step-by-step matrix-tenzor procedures (for SNIR) and procedures of defining of space-dependent equivalental functions from two images (for SIR).

Recent progress on understanding the mechanisms of amyloid nucleation.

PubMed

Chatani, Eri; Yamamoto, Naoki

2018-04-01

Amyloid fibrils are supramolecular protein assemblies with a fibrous morphology and cross-β structure. The formation of amyloid fibrils typically follows a nucleation-dependent polymerization mechanism, in which a one-step nucleation scheme has widely been accepted. However, a variety of oligomers have been identified in early stages of fibrillation, and a nucleated conformational conversion (NCC) mechanism, in which oligomers serve as a precursor of amyloid nucleation and convert to amyloid nuclei, has been proposed. This development has raised the need to consider more complicated multi-step nucleation processes in addition to the simplest one-step process, and evidence for the direct involvement of oligomers as nucleation precursors has been obtained both experimentally and theoretically. Interestingly, the NCC mechanism has some analogy with the two-step nucleation mechanism proposed for inorganic and organic crystals and protein crystals, although a more dramatic conformational conversion of proteins should be considered in amyloid nucleation. Clarifying the properties of the nucleation precursors of amyloid fibrils in detail, in comparison with those of crystals, will allow a better understanding of the nucleation of amyloid fibrils and pave the way to develop techniques to regulate it.

Magnesite Step Growth Rates as a Function of the Aqueous Magnesium:Carbonate Ratio

DOE PAGES

Bracco, Jacquelyn N.; Stack, Andrew G.; Higgins, Steven R.

2014-10-01

Step velocities of monolayer-height steps on the (101 ⁻4) magnesite surface have been measured as functions of the aqueous magnesium-to-carbonate ratio and saturation index (SI) using a hydrothermal atomic force microscope (HAFM). At SI ≤ 1.9 and 80-90 °C, step velocities were found to be invariant with changes in the magnesium-to-carbonate ratio, an observation in contrast with standard models for growth and dissolution of ionically-bonded, multi-component crystals. However, at high saturation indices (SI = 2.15), step velocities displayed a ratio dependence, maximized at magnesium-to-carbonate ratios slightly greater than 1:1. Traditional affinity-based models were unable to describe growth rates at themore » higher saturation index. Step velocities also could not be modeled solely through nucleation of kink sites, in contrast to other minerals whose bonding between constituent ions is also dominantly ionic in nature, such as calcite and barite. Instead, they could be described only by a model that incorporates both kink nucleation and propagation. Based on observed step morphological changes at these higher saturation indices, the step velocity maximum at SI = 2.15 is likely due to the rate of attachment to propagating kink sites overcoming the rate of detachment from kink sites as the latter becomes less significant under far from equilibrium conditions.« less

A Systems Approach towards an Intelligent and Self-Controlling Platform for Integrated Continuous Reaction Sequences**

PubMed Central

Ingham, Richard J; Battilocchio, Claudio; Fitzpatrick, Daniel E; Sliwinski, Eric; Hawkins, Joel M; Ley, Steven V

2015-01-01

Performing reactions in flow can offer major advantages over batch methods. However, laboratory flow chemistry processes are currently often limited to single steps or short sequences due to the complexity involved with operating a multi-step process. Using new modular components for downstream processing, coupled with control technologies, more advanced multi-step flow sequences can be realized. These tools are applied to the synthesis of 2-aminoadamantane-2-carboxylic acid. A system comprising three chemistry steps and three workup steps was developed, having sufficient autonomy and self-regulation to be managed by a single operator. PMID:25377747

Scale effect challenges in urban hydrology highlighted with a Fully Distributed Model and High-resolution rainfall data

NASA Astrophysics Data System (ADS)

Ichiba, Abdellah; Gires, Auguste; Tchiguirinskaia, Ioulia; Schertzer, Daniel; Bompard, Philippe; Ten Veldhuis, Marie-Claire

2017-04-01

Nowadays, there is a growing interest on small-scale rainfall information, provided by weather radars, to be used in urban water management and decision-making. Therefore, an increasing interest is in parallel devoted to the development of fully distributed and grid-based models following the increase of computation capabilities, the availability of high-resolution GIS information needed for such models implementation. However, the choice of an appropriate implementation scale to integrate the catchment heterogeneity and the whole measured rainfall variability provided by High-resolution radar technologies still issues. This work proposes a two steps investigation of scale effects in urban hydrology and its effects on modeling works. In the first step fractal tools are used to highlight the scale dependency observed within distributed data used to describe the catchment heterogeneity, both the structure of the sewer network and the distribution of impervious areas are analyzed. Then an intensive multi-scale modeling work is carried out to understand scaling effects on hydrological model performance. Investigations were conducted using a fully distributed and physically based model, Multi-Hydro, developed at Ecole des Ponts ParisTech. The model was implemented at 17 spatial resolutions ranging from 100 m to 5 m and modeling investigations were performed using both rain gauge rainfall information as well as high resolution X band radar data in order to assess the sensitivity of the model to small scale rainfall variability. Results coming out from this work demonstrate scale effect challenges in urban hydrology modeling. In fact, fractal concept highlights the scale dependency observed within distributed data used to implement hydrological models. Patterns of geophysical data change when we change the observation pixel size. The multi-scale modeling investigation performed with Multi-Hydro model at 17 spatial resolutions confirms scaling effect on hydrological model performance. Results were analyzed at three ranges of scales identified in the fractal analysis and confirmed in the modeling work. The sensitivity of the model to small-scale rainfall variability was discussed as well.

Evaluation of accuracy in implant site preparation performed in single- or multi-step drilling procedures.

PubMed

Marheineke, Nadine; Scherer, Uta; Rücker, Martin; von See, Constantin; Rahlf, Björn; Gellrich, Nils-Claudius; Stoetzer, Marcus

2018-06-01

Dental implant failure and insufficient osseointegration are proven results of mechanical and thermal damage during the surgery process. We herein performed a comparative study of a less invasive single-step drilling preparation protocol and a conventional multiple drilling sequence. Accuracy of drilling holes was precisely analyzed and the influence of different levels of expertise of the handlers and additional use of drill template guidance was evaluated. Six experimental groups, deployed in an osseous study model, were representing template-guided and freehanded drilling actions in a stepwise drilling procedure in comparison to a single-drill protocol. Each experimental condition was studied by the drilling actions of respectively three persons without surgical knowledge as well as three highly experienced oral surgeons. Drilling actions were performed and diameters were recorded with a precision measuring instrument. Less experienced operators were able to significantly increase the drilling accuracy using a guiding template, especially when multi-step preparations are performed. Improved accuracy without template guidance was observed when experienced operators were executing single-step versus multi-step technique. Single-step drilling protocols have shown to produce more accurate results than multi-step procedures. The outcome of any protocol can be further improved by use of guiding templates. Operator experience can be a contributing factor. Single-step preparations are less invasive and are promoting osseointegration. Even highly experienced surgeons are achieving higher levels of accuracy by combining this technique with template guidance. Hereby template guidance enables a reduction of hands-on time and side effects during surgery and lead to a more predictable clinical diameter.

Enzyme reversal to explore the function of yeast E3 ubiquitin-ligases.

PubMed

MacDonald, Chris; Winistorfer, Stanley; Pope, Robert M; Wright, Michael E; Piper, Robert C

2017-07-01

The covalent attachment of ubiquitin onto proteins can elicit a variety of downstream consequences. Attachment is mediated by a large array of E3 ubiquitin ligases, each thought be subject to regulatory control and to have a specific repertoire of substrates. Assessing the biological roles of ligases, and in particular, identifying their biologically relevant substrates has been a persistent yet challenging question. In this study, we describe tools that may help achieve both of these goals. We describe a strategy whereby the activity of a ubiquitin ligase has been enzymatically reversed, accomplished by fusing it to a catalytic domain of an exogenous deubiquitinating enzyme. We present a library of 72 "anti-ligases" that appear to work in a dominant-negative fashion to stabilize their cognate substrates against ubiquitin-dependent proteasomal and lysosomal degradation. We then used the ligase-deubiquitinating enzyme (DUb) library to screen for E3 ligases involved in post-Golgi/endosomal trafficking. We identify ligases previously implicated in these pathways (Rsp5 and Tul1), in addition to ligases previously localized to endosomes (Pib1 and Vps8). We also document an optimized workflow for isolating and analyzing the "ubiquitome" of yeast, which can be used with mass spectrometry to identify substrates perturbed by expression of particular ligase-DUb fusions. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bowman, Adam J.; Scherrer, Joseph R.; Reiserer, Ronald S., E-mail: ron.reiserer@vanderbilt.edu

We present a simple apparatus for improved surface modification of polydimethylsiloxane (PDMS) microfluidic devices. A single treatment chamber for plasma activation and chemical/physical vapor deposition steps minimizes the time-dependent degradation of surface activation that is inherent in multi-chamber techniques. Contamination and deposition irregularities are also minimized by conducting plasma activation and treatment phases in the same vacuum environment. An inductively coupled plasma driver allows for interchangeable treatment chambers. Atomic force microscopy confirms that silane deposition on PDMS gives much better surface quality than standard deposition methods, which yield a higher local roughness and pronounced irregularities in the surface.

Method to Improve Indium Bump Bonding via Indium Oxide Removal Using a Multi-Step Plasma Process

NASA Technical Reports Server (NTRS)

Dickie, Matthew R. (Inventor); Nikzad, Shouleh (Inventor); Greer, H. Frank (Inventor); Jones, Todd J. (Inventor); Vasquez, Richard P. (Inventor); Hoenk, Michael E. (Inventor)

2012-01-01

A process for removing indium oxide from indium bumps in a flip-chip structure to reduce contact resistance, by a multi-step plasma treatment. A first plasma treatment of the indium bumps with an argon, methane and hydrogen plasma reduces indium oxide, and a second plasma treatment with an argon and hydrogen plasma removes residual organics. The multi-step plasma process for removing indium oxide from the indium bumps is more effective in reducing the oxide, and yet does not require the use of halogens, does not change the bump morphology, does not attack the bond pad material or under-bump metallization layers, and creates no new mechanisms for open circuits.

Interplay of wavelength, fluence and spot-size in free-electron laser ablation of cornea.

PubMed

Hutson, M Shane; Ivanov, Borislav; Jayasinghe, Aroshan; Adunas, Gilma; Xiao, Yaowu; Guo, Mingsheng; Kozub, John

2009-06-08

Infrared free-electron lasers ablate tissue with high efficiency and low collateral damage when tuned to the 6-microm range. This wavelength-dependence has been hypothesized to arise from a multi-step process following differential absorption by tissue water and proteins. Here, we test this hypothesis at wavelengths for which cornea has matching overall absorption, but drastically different differential absorption. We measure etch depth, collateral damage and plume images and find that the hypothesis is not confirmed. We do find larger etch depths for larger spot sizes--an effect that can lead to an apparent wavelength dependence. Plume imaging at several wavelengths and spot sizes suggests that this effect is due to increased post-pulse ablation at larger spots.

Electron correlations and pre-collision in the re-collision picture of high harmonic generation

NASA Astrophysics Data System (ADS)

Mašín, Zdeněk; Harvey, Alex G.; Spanner, Michael; Patchkovskii, Serguei; Ivanov, Misha; Smirnova, Olga

2018-07-01

We discuss the seminal three-step model and the re-collision picture in the context of high harmonic generation in molecules. In particular, we stress the importance of multi-electron correlation during the first and the third of the three steps of the process: (1) the strong-field ionization and (3) the recombination. We point out how an accurate account of multi-electron correlations during the third recombination step allows one to gauge the importance of pre-collision: the term coined by Eberly (n.d. private communication) to describe unusual pathways during the first, ionization, step.

Description of bioremediation of soils using the model of a multistep system of microorganisms

NASA Astrophysics Data System (ADS)

Lubysheva, A. I.; Potashev, K. A.; Sofinskaya, O. A.

2018-01-01

The paper deals with the development of a mathematical model describing the interaction of a multi-step system of microorganisms in soil polluted with oil products. Each step in this system uses products of vital activity of the previous step to feed. Six different models of the multi-step system are considered. The equipping of the models with coefficients was carried out from the condition of minimizing the residual of the calculated and experimental data using an original algorithm based on the Levenberg-Marquardt method in combination with the Monte Carlo method for the initial approximation finding.

Multi-camera sensor system for 3D segmentation and localization of multiple mobile robots.

PubMed

Losada, Cristina; Mazo, Manuel; Palazuelos, Sira; Pizarro, Daniel; Marrón, Marta

2010-01-01

This paper presents a method for obtaining the motion segmentation and 3D localization of multiple mobile robots in an intelligent space using a multi-camera sensor system. The set of calibrated and synchronized cameras are placed in fixed positions within the environment (intelligent space). The proposed algorithm for motion segmentation and 3D localization is based on the minimization of an objective function. This function includes information from all the cameras, and it does not rely on previous knowledge or invasive landmarks on board the robots. The proposed objective function depends on three groups of variables: the segmentation boundaries, the motion parameters and the depth. For the objective function minimization, we use a greedy iterative algorithm with three steps that, after initialization of segmentation boundaries and depth, are repeated until convergence.

Full-color, large area, transmissive holograms enabled by multi-level diffractive optics.

PubMed

Mohammad, Nabil; Meem, Monjurul; Wan, Xiaowen; Menon, Rajesh

2017-07-19

We show that multi-level diffractive microstructures can enable broadband, on-axis transmissive holograms that can project complex full-color images, which are invariant to viewing angle. Compared to alternatives like metaholograms, diffractive holograms utilize much larger minimum features (>10 µm), much smaller aspect ratios (<0.2) and thereby, can be fabricated in a single lithography step over relatively large areas (>30 mm ×30 mm). We designed, fabricated and characterized holograms that encode various full-color images. Our devices demonstrate absolute transmission efficiencies of >86% across the visible spectrum from 405 nm to 633 nm (peak value of about 92%), and excellent color fidelity. Furthermore, these devices do not exhibit polarization dependence. Finally, we emphasize that our devices exhibit negligible absorption and are phase-only holograms with high diffraction efficiency.

Mechanochemical coupling and bi-phasic force-velocity dependence in the ultra-fast ring ATPase SpoIIIE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Ninning; Chistol, Gheorghe; Cui, Yuanbo

Multi-subunit ring-shaped ATPases are molecular motors that harness chemical free energy to perform vital mechanical tasks such as polypeptide translocation, DNA unwinding, and chromosome segregation. Previously we reported the intersubunit coordination and stepping behavior of the hexameric ring-shaped ATPase SpoIIIE (Liu et al., 2015). Here we use optical tweezers to characterize the motor’s mechanochemistry. Analysis of the motor response to external force at various nucleotide concentrations identifies phosphate release as the likely force-generating step. Analysis of SpoIIIE pausing indicates that pauses are off-pathway events. Characterization of SpoIIIE slipping behavior reveals that individual motor subunits engage DNA upon ATP binding. Furthermore,more » we find that SpoIIIE’s velocity exhibits an intriguing bi-phasic dependence on force. We hypothesize that this behavior is an adaptation of ultra-fast motors tasked with translocating DNA from which they must also remove DNA-bound protein roadblocks. Based on these results, we formulate a comprehensive mechanochemical model for SpoIIIE.« less

Mechanochemical coupling and bi-phasic force-velocity dependence in the ultra-fast ring ATPase SpoIIIE

DOE PAGES

Liu, Ninning; Chistol, Gheorghe; Cui, Yuanbo; ...

2018-03-05

Multi-subunit ring-shaped ATPases are molecular motors that harness chemical free energy to perform vital mechanical tasks such as polypeptide translocation, DNA unwinding, and chromosome segregation. Previously we reported the intersubunit coordination and stepping behavior of the hexameric ring-shaped ATPase SpoIIIE (Liu et al., 2015). Here we use optical tweezers to characterize the motor’s mechanochemistry. Analysis of the motor response to external force at various nucleotide concentrations identifies phosphate release as the likely force-generating step. Analysis of SpoIIIE pausing indicates that pauses are off-pathway events. Characterization of SpoIIIE slipping behavior reveals that individual motor subunits engage DNA upon ATP binding. Furthermore,more » we find that SpoIIIE’s velocity exhibits an intriguing bi-phasic dependence on force. We hypothesize that this behavior is an adaptation of ultra-fast motors tasked with translocating DNA from which they must also remove DNA-bound protein roadblocks. Based on these results, we formulate a comprehensive mechanochemical model for SpoIIIE.« less

Overview of Sentinel-2

NASA Astrophysics Data System (ADS)

Fernandez, Valerie; Martimort, Philippe; Spoto, Francois; Sy, Omar; Laberinti, Paolo

2013-10-01

GMES is a joint initiative of the European Commission (EC) and the European Space Agency (ESA), designed to establish a European capacity for the provision and use of operational monitoring information for environment and security applications. ESA's role in GMES is to provide the definition and the development of the space- and ground-related system elements. GMES Sentinel-2 mission provides continuity to services relying on multi-spectral highresolution optical observations over global terrestrial surfaces. The key mission objectives for Sentinel-2 are: (1) to provide systematic global acquisitions of high-resolution multi-spectral imagery with a high revisit frequency, (2) to provide enhanced continuity of multi-spectral imagery provided by the SPOT series of satellites, and (3) to provide observations for the next generation of operational products such as landcover maps, land change detection maps, and geophysical variables. Consequently, Sentinel-2 will directly contribute to the Land Monitoring, Emergency Response, and Security services. The corresponding user requirements have driven the design towards a dependable multi-spectral Earthobservation system featuring the MSI with 13 spectral bands spanning from the visible and the near infrared to the short wave infrared. The spatial resolution varies from 10 m to 60 m depending on the spectral band with a 290 km field of view. This unique combination of high spatial resolution, wide field of view and large spectral coverage will represent a major step forward compared to current multi-spectral missions. The mission foresees a series of satellites, each having a 7.25-year lifetime (extendable to 12 years) over a 20-year period starting with the launch of Sentinel-2A foreseen by mid-2014. During full operations two identical satellites will be maintained in the same sun synchronous orbit with a phase delay of 180° providing a revisit time of five days at the equator.

Mass dependent stable isotope fractionation of mercury during mer mediated microbial degradation of monomethylmercury

NASA Astrophysics Data System (ADS)

Kritee, K.; Barkay, Tamar; Blum, Joel D.

2009-03-01

Controlling bioaccumulation of toxic monomethylmercury (MMHg) in aquatic food chains requires differentiation between biotic and abiotic pathways that lead to its production and degradation. Recent mercury (Hg) stable isotope measurements of natural samples suggest that Hg isotope ratios can be a powerful proxy for tracing dominant Hg transforming pathways in aquatic ecosystems. Specifically, it has been shown that photo-degradation of MMHg causes both mass dependent (MDF) and mass independent fractionation (MIF) of Hg isotopes. Because the extent of MDF and MIF observed in natural samples (e.g., fish, soil and sediments) can potentially be used to determine the relative importance of pathways leading to MMHg accumulation, it is important to determine the potential role of microbial pathways in contributing to the fractionation, especially MIF, observed in these samples. This study reports the extent of fractionation of Hg stable isotopes during degradation of MMHg to volatile elemental Hg and methane via the microbial Hg resistance ( mer) pathway in Escherichia coli carrying a mercury resistance ( mer) genetic system on a multi-copy plasmid. During experimental microbial degradation of MMHg, MMHg remaining in reactors became progressively heavier (increasing δ202Hg) with time and underwent mass dependent Rayleigh fractionation with a fractionation factor α202/198 = 1.0004 ± 0.0002 (2SD). However, MIF was not observed in any of the microbial MMHg degradation experiments indicating that the isotopic signature left by mer mediated MMHg degradation is significantly different from fractionation observed during DOC mediated photo-degradation of MMHg. Additionally, a clear suppression of Hg isotope fractionation, both during reduction of Hg(II) and degradation of MMHg, was observed when the cell densities increased, possibly due to a reduction in substrate bioavailability. We propose a multi-step framework for understanding the extent of fractionation seen in our MMHg degradation experiments and, based on estimates of the rates of the various steps involved in this mer mediated pathway, suggest which steps in the process could contribute towards the observed extent of fractionation. This framework suggests that at lower cell densities catalysis by MerB was the rate limiting step while at higher cell densities transport into the cell, which does not cause fractionation, became the rate limiting step. In addition to presenting evidence for absence of MIF during mer mediated Hg transformations, based on the nature of Hg compounds and microbe-Hg interactions, we suggest that the nuclear spin dependent MIF (i.e., the magnetic isotope effect) is also unlikely to occur during other non mer mediated 'dark' microbial Hg transformations (e.g., formation of MMHg and oxidative degradation of MMHg). Because of the important implications of the absence of MIF during biological processes on Hg isotope systematics, we discuss theoretical considerations and experimental strategies that could be used to confirm this suggestion.

Multi-Step Deep Reactive Ion Etching Fabrication Process for Silicon-Based Terahertz Components

NASA Technical Reports Server (NTRS)

Reck, Theodore (Inventor); Perez, Jose Vicente Siles (Inventor); Lee, Choonsup (Inventor); Cooper, Ken B. (Inventor); Jung-Kubiak, Cecile (Inventor); Mehdi, Imran (Inventor); Chattopadhyay, Goutam (Inventor); Lin, Robert H. (Inventor); Peralta, Alejandro (Inventor)

2016-01-01

A multi-step silicon etching process has been developed to fabricate silicon-based terahertz (THz) waveguide components. This technique provides precise dimensional control across multiple etch depths with batch processing capabilities. Nonlinear and passive components such as mixers and multipliers waveguides, hybrids, OMTs and twists have been fabricated and integrated into a small silicon package. This fabrication technique enables a wafer-stacking architecture to provide ultra-compact multi-pixel receiver front-ends in the THz range.

Stable aqueous dispersions of functionalized multi-layer graphene by pulsed underwater plasma exfoliation of graphite

NASA Astrophysics Data System (ADS)

Meyer-Plath, Asmus; Beckert, Fabian; Tölle, Folke J.; Sturm, Heinz; Mülhaupt, Rolf

2016-02-01

A process was developed for graphite particle exfoliation in water to stably dispersed multi-layer graphene. It uses electrohydraulic shockwaves and the functionalizing effect of solution plasma discharges in water. The discharges were excited by 100 ns high voltage pulsing of graphite particle chains that bridge an electrode gap. The underwater discharges allow simultaneous exfoliation and chemical functionalization of graphite particles to partially oxidized multi-layer graphene. Exfoliation is caused by shockwaves that result from rapid evaporation of carbon and water to plasma-excited gas species. Depending on discharge energy and locus of ignition, the shockwaves cause stirring, erosion, exfoliation and/or expansion of graphite flakes. The process was optimized to produce long-term stable aqueous dispersions of multi-layer graphene from graphite in a single process step without requiring addition of intercalants, surfactants, binders or special solvents. A setup was developed that allows continuous production of aqueous dispersions of flake size-selected multi-layer graphenes. Due to the well-preserved sp2-carbon structure, thin films made from the dispersed graphene exhibited high electrical conductivity. Underwater plasma discharge processing exhibits high innovation potential for morphological and chemical modifications of carbonaceous materials and surfaces, especially for the generation of stable dispersions of two-dimensional, layered materials.

A successful backward step correlates with hip flexion moment of supporting limb in elderly people.

PubMed

Takeuchi, Yahiko

2018-01-01

The objective of this study was to determine the positional relationship between the center of mass (COM) and the center of pressure (COP) at the time of step landing, and to examine their relationship with the joint moments exerted by the supporting limb, with regard to factors of the successful backward step response. The study population comprised 8 community-dwelling elderly people that were observed to take successive multi steps after the landing of a backward stepping. Using a motion capture system and force plate, we measured the COM, COP and COM-COP deviation distance on landing during backward stepping. In addition, we measured the moment of the supporting limb joint during backward stepping. The multi-step data were compared with data from instances when only one step was taken (single-step). Variables that differed significantly between the single- and multi-step data were used as objective variables and the joint moments of the supporting limb were used as explanatory variables in single regression analyses. The COM-COP deviation in the anteroposterior was significantly larger in the single-step. A regression analysis with COM-COP deviation as the objective variable obtained a significant regression equation in the hip flexion moment (R2 = 0.74). The hip flexion moment of supporting limb was shown to be a significant explanatory variable in both the PS and SS phases for the relationship with COM-COP distance. This study found that to create an appropriate backward step response after an external disturbance (i.e. the ability to stop after 1 step), posterior braking of the COM by a hip flexion moment are important during the single-limbed standing phase.

Numerical prediction of fire resistance of RC beams

NASA Astrophysics Data System (ADS)

Serega, Szymon; Wosatko, Adam

2018-01-01

Fire resistance of different structural members is an important issue of their strength and durability. A simple but effective tool to investigate multi-span reinforced concrete beams exposed to fire is discussed in the paper. Assumptions and simplifications of the theory as well as numerical aspects are briefly reviewed. Two steps of nonlinear finite element analysis and two levels of observation are distinguished. The first step is the solution of transient heat transfer problem in representative two-dimensional reinforced concrete cross-section of a beam. The second part is a nonlinear mechanical analysis of the whole beam. All spans are uniformly loaded, but an additional time-dependent thermal load due to fire acts on selected ones. Global changes of curvature and bending moment functions induce deterioration of the stiffness. Benchmarks are shown to confirm the correctness of the model.

Complex Degradation Processes Lead to Non-Exponential Decay Patterns and Age-Dependent Decay Rates of Messenger RNA

PubMed Central

Deneke, Carlus; Lipowsky, Reinhard; Valleriani, Angelo

2013-01-01

Experimental studies on mRNA stability have established several, qualitatively distinct decay patterns for the amount of mRNA within the living cell. Furthermore, a variety of different and complex biochemical pathways for mRNA degradation have been identified. The central aim of this paper is to bring together both the experimental evidence about the decay patterns and the biochemical knowledge about the multi-step nature of mRNA degradation in a coherent mathematical theory. We first introduce a mathematical relationship between the mRNA decay pattern and the lifetime distribution of individual mRNA molecules. This relationship reveals that the mRNA decay patterns at steady state expression level must obey a general convexity condition, which applies to any degradation mechanism. Next, we develop a theory, formulated as a Markov chain model, that recapitulates some aspects of the multi-step nature of mRNA degradation. We apply our theory to experimental data for yeast and explicitly derive the lifetime distribution of the corresponding mRNAs. Thereby, we show how to extract single-molecule properties of an mRNA, such as the age-dependent decay rate and the residual lifetime. Finally, we analyze the decay patterns of the whole translatome of yeast cells and show that yeast mRNAs can be grouped into three broad classes that exhibit three distinct decay patterns. This paper provides both a method to accurately analyze non-exponential mRNA decay patterns and a tool to validate different models of degradation using decay data. PMID:23408982

Investigation of multi-stage cold forward extrusion process using coupled thermo-mechanical finite element analysis

NASA Astrophysics Data System (ADS)

Görtan, Mehmet Okan

2018-05-01

Cold extrusion processes are distinguished by their low material usage as well as great efficiency in the production of mid-range and large component series. Although majority of the cold extruded parts are produced using die systems containing multiple forming stages, this subject has rarely been investigated so far. Therefore, the characteristics of multi-stage cold forward rod extrusion is studied in the current work using thermo-mechanically coupled finite element (FE) analysis. A case hardening steel, 16MnCr5 (1.7131) was used as experimental material. Its strain, strain rate and temperature dependent mechanical characteristics were determined using compression testing and modeled in FE simulations via a Johnson-Cook material model. Friction coefficients for the same material while in contact with a tool steel (1.2379) were determined dependent on temperature and contact pressure using sliding compression test (SCT) and modeled by an adaptive friction model developed by the author. In the first set of simulations, rod material with a diameter of 14.9 mm was extruded down to a diameter of 9.6 mm in a single step using three different die opening angles (2α); 20°, 40° and 60°. In the second set of investigations, the same rod was reduced first to 12 mm and then to 9.6 mm in two steps within the same forming die. Press forces, contact normal stresses between extruded material and forming die, material temperature and axial stresses are compared in these two set of simulations and the differences are discussed.

Use of Chiral Oxazolidinones for a Multi-Step Synthetic Laboratory Module

ERIC Educational Resources Information Center

Betush, Matthew P.; Murphree, S. Shaun

2009-01-01

Chiral oxazolidinone chemistry is used as a framework for an advanced multi-step synthesis lab. The cost-effective and robust preparation of chiral starting materials is presented, as well as the use of chiral auxiliaries in a synthesis scheme that is appropriate for students currently in the second semester of the organic sequence. (Contains 1…

Controllable 3D architectures of aligned carbon nanotube arrays by multi-step processes

NASA Astrophysics Data System (ADS)

Huang, Shaoming

2003-06-01

An effective way to fabricate large area three-dimensional (3D) aligned CNTs pattern based on pyrolysis of iron(II) phthalocyanine (FePc) by two-step processes is reported. The controllable generation of different lengths and selective growth of the aligned CNT arrays on metal-patterned (e.g., Ag and Au) substrate are the bases for generating such 3D aligned CNTs architectures. By controlling experimental conditions 3D aligned CNT arrays with different lengths/densities and morphologies/structures as well as multi-layered architectures can be fabricated in large scale by multi-step pyrolysis of FePc. These 3D architectures could have interesting properties and be applied for developing novel nanotube-based devices.

Contribution of lower limb eccentric work and different step responses to balance recovery among older adults.

PubMed

Nagano, Hanatsu; Levinger, Pazit; Downie, Calum; Hayes, Alan; Begg, Rezaul

2015-09-01

Falls during walking reflect susceptibility to balance loss and the individual's capacity to recover stability. Balance can be recovered using either one step or multiple steps but both responses are impaired with ageing. To investigate older adults' (n=15, 72.5±4.8 yrs) recovery step control a tether-release procedure was devised to induce unanticipated forward balance loss. Three-dimensional position-time data combined with foot-ground reaction forces were used to measure balance recovery. Dependent variables were; margin of stability (MoS) and available response time (ART) for spatial and temporal balance measures in the transverse and sagittal planes; lower limb joint angles and joint negative/positive work; and spatio-temporal gait parameters. Relative to multi-step responses, single-step recovery was more effective in maintaining balance, indicated by greater MoS and longer ART. MoS in the sagittal plane measure and ART in the transverse plane distinguished single step responses from multiple steps. When MoS and ART were negative (<0), balance was not secured and additional steps would be required to establish the new base of support for balance recovery. Single-step responses demonstrated greater step length and velocity and when the recovery foot landed, greater centre of mass downward velocity. Single-step strategies also showed greater ankle dorsiflexion, increased knee maximum flexion and more negative work at the ankle and knee. Collectively these findings suggest that single-step responses are more effective in forward balance recovery by directing falling momentum downward to be absorbed as lower limb eccentric work. Copyright © 2015 Elsevier B.V. All rights reserved.

Multi-criteria decision making to support waste management: A critical review of current practices and methods.

PubMed

Goulart Coelho, Lineker M; Lange, Liséte C; Coelho, Hosmanny Mg

2017-01-01

Solid waste management is a complex domain involving the interaction of several dimensions; thus, its analysis and control impose continuous challenges for decision makers. In this context, multi-criteria decision-making models have become important and convenient supporting tools for solid waste management because they can handle problems involving multiple dimensions and conflicting criteria. However, the selection of the multi-criteria decision-making method is a hard task since there are several multi-criteria decision-making approaches, each one with a large number of variants whose applicability depends on information availability and the aim of the study. Therefore, to support researchers and decision makers, the objectives of this article are to present a literature review of multi-criteria decision-making applications used in solid waste management, offer a critical assessment of the current practices, and provide suggestions for future works. A brief review of fundamental concepts on this topic is first provided, followed by the analysis of 260 articles related to the application of multi-criteria decision making in solid waste management. These studies were investigated in terms of the methodology, including specific steps such as normalisation, weighting, and sensitivity analysis. In addition, information related to waste type, the study objective, and aspects considered was recorded. From the articles analysed it is noted that studies using multi-criteria decision making in solid waste management are predominantly addressed to problems related to municipal solid waste involving facility location or management strategy.

Multi-functional surface acoustic wave sensor for monitoring enviromental and structural condition

NASA Astrophysics Data System (ADS)

Furuya, Y.; Kon, T.; Okazaki, T.; Saigusa, Y.; Nomura, T.

2006-03-01

As a first step to develop a health monitoring system with active and embedded nondestructive evaluation devices for the machineries and structures, multi-functional SAW (surface acoustic wave) device was developed. A piezoelectric LiNbO3(x-y cut) materials were used as a SAW substrate on which IDT(20μm pitch) was produced by lithography. On the surface of a path of SAW between IDTs, environmentally active material films of shape memory Ti50Ni41Cu(at%) with non-linear hysteresis and superelastic Ti48Ni43Cu(at%) with linear deformation behavior were formed by magnetron-sputtering technique. In this study, these two kinds of shape memory alloys SMA) system were used to measure 1) loading level, 2) phase transformation and 3)stress-strain hysteresis under cyclic loading by utilizing their linearity and non-linearity deformation behaviors. Temperature and stress dependencies of SAW signal were also investigated in the non-sputtered film state. Signal amplitude and phase change of SAW were chosen to measure as the sensing parameters. As a result, temperature, stress level, phase transformation in SMA depending on temperature and mechanical damage accumulation could be measured by the proposed multi-functional SAW sensor. Moreover, the wireless SAW sensing system which has a unique feature of no supplying electric battery was constructed, and the same characteristic evaluation is confirmed in comparison with wired case.

Twitchin can regulate the ATPase cycle of actomyosin in a phosphorylation-dependent manner in skinned mammalian skeletal muscle fibres.

PubMed

Avrova, Stanislava V; Rysev, Nikita A; Matusovsky, Oleg S; Shelud'ko, Nikolay S; Borovikov, Yurii S

2012-05-01

The effect of twitchin, a thick filament protein of molluscan muscles, on the actin-myosin interaction at several mimicked sequential steps of the ATPase cycle was investigated using the polarized fluorescence of 1.5-IAEDANS bound to myosin heads, FITC-phalloidin attached to actin and acrylodan bound to twitchin in the glycerol-skinned skeletal muscle fibres of mammalian. The phosphorylation-dependent multi-step changes in mobility and spatial arrangement of myosin SH1 helix, actin subunit and twitchin during the ATPase cycle have been revealed. It was shown that nonphosphorylated twitchin inhibited the movements of SH1 helix of the myosin heads and actin subunits and decreased the affinity of myosin to actin by freezing the position and mobility of twitchin in the muscle fibres. The phosphorylation of twitchin reverses this effect by changing the spatial arrangement and mobility of the actin-binding portions of twitchin. In this case, enhanced movements of SH1 helix of the myosin heads and actin subunits are observed. The data imply a novel property of twitchin incorporated into organized contractile system: its ability to regulate the ATPase cycle in a phosphorylation-dependent fashion by changing the affinity and spatial arrangement of the actin-binding portions of twitchin. Copyright © 2012 Elsevier Inc. All rights reserved.

Optimization of magnetic flux density measurement using multiple RF receiver coils and multi-echo in MREIT.

PubMed

Jeong, Woo Chul; Chauhan, Munish; Sajib, Saurav Z K; Kim, Hyung Joong; Serša, Igor; Kwon, Oh In; Woo, Eung Je

2014-09-07

Magnetic Resonance Electrical Impedance Tomography (MREIT) is an MRI method that enables mapping of internal conductivity and/or current density via measurements of magnetic flux density signals. The MREIT measures only the z-component of the induced magnetic flux density B = (Bx, By, Bz) by external current injection. The measured noise of Bz complicates recovery of magnetic flux density maps, resulting in lower quality conductivity and current-density maps. We present a new method for more accurate measurement of the spatial gradient of the magnetic flux density gradient (∇ Bz). The method relies on the use of multiple radio-frequency receiver coils and an interleaved multi-echo pulse sequence that acquires multiple sampling points within each repetition time. The noise level of the measured magnetic flux density Bz depends on the decay rate of the signal magnitude, the injection current duration, and the coil sensitivity map. The proposed method uses three key steps. The first step is to determine a representative magnetic flux density gradient from multiple receiver coils by using a weighted combination and by denoising the measured noisy data. The second step is to optimize the magnetic flux density gradient by using multi-echo magnetic flux densities at each pixel in order to reduce the noise level of ∇ Bz and the third step is to remove a random noise component from the recovered ∇ Bz by solving an elliptic partial differential equation in a region of interest. Numerical simulation experiments using a cylindrical phantom model with included regions of low MRI signal to noise ('defects') verified the proposed method. Experimental results using a real phantom experiment, that included three different kinds of anomalies, demonstrated that the proposed method reduced the noise level of the measured magnetic flux density. The quality of the recovered conductivity maps using denoised ∇ Bz data showed that the proposed method reduced the conductivity noise level up to 3-4 times at each anomaly region in comparison to the conventional method.

Dynamics of Metabolite Induction in Fungal Co-cultures by Metabolomics at Both Volatile and Non-volatile Levels

PubMed Central

Azzollini, Antonio; Boggia, Lorenzo; Boccard, Julien; Sgorbini, Barbara; Lecoultre, Nicole; Allard, Pierre-Marie; Rubiolo, Patrizia; Rudaz, Serge; Gindro, Katia; Bicchi, Carlo; Wolfender, Jean-Luc

2018-01-01

Fungal co-cultivation has emerged as a promising way for activating cryptic biosynthetic pathways and discovering novel antimicrobial metabolites. For the success of such studies, a key element remains the development of standardized co-cultivation methods compatible with high-throughput analytical procedures. To efficiently highlight induction processes, it is crucial to acquire a holistic view of intermicrobial communication at the molecular level. To tackle this issue, a strategy was developed based on the miniaturization of fungal cultures that allows for a concomitant survey of induction phenomena in volatile and non-volatile metabolomes. Fungi were directly grown in vials, and each sample was profiled by head space solid phase microextraction gas chromatography mass spectrometry (HS-SPME-GC-MS), while the corresponding solid culture medium was analyzed by liquid chromatography high resolution mass spectrometry (LC-HRMS) after solvent extraction. This strategy was implemented for the screening of volatile and non-volatile metabolite inductions in an ecologically relevant fungal co-culture of Eutypa lata (Pers.) Tul. & C. Tul. (Diatrypaceae) and Botryosphaeria obtusa (Schwein.) Shoemaker (Botryosphaeriaceae), two wood-decaying fungi interacting in the context of esca disease of grapevine. For a comprehensive evaluation of the results, a multivariate data analysis combining Analysis of Variance and Partial Least Squares approaches, namely AMOPLS, was used to explore the complex LC-HRMS and GC-MS datasets and highlight dynamically induced compounds. A time-series study was carried out over 9 days, showing characteristic metabolite induction patterns in both volatile and non-volatile dimensions. Relevant links between the dynamics of expression of specific metabolite production were observed. In addition, the antifungal activity of 2-nonanone, a metabolite incrementally produced over time in the volatile fraction, was assessed against Eutypa lata and Botryosphaeria obtusa in an adapted bioassay set for volatile compounds. This compound has shown antifungal activity on both fungi and was found to be co-expressed with a known antifungal compound, O-methylmellein, induced in solid media. This strategy could help elucidate microbial inter- and intra-species cross-talk at various levels. Moreover, it supports the study of concerted defense/communication mechanisms for efficiently identifying original antimicrobials. PMID:29459851

Identifying sources of groundwater nitrate contamination in a large alluvial groundwater basin with highly diversified intensive agricultural production

NASA Astrophysics Data System (ADS)

Lockhart, K. M.; King, A. M.; Harter, T.

2013-08-01

Groundwater quality is a concern in alluvial aquifers underlying agricultural areas worldwide. Nitrate from land applied fertilizers or from animal waste can leach to groundwater and contaminate drinking water resources. The San Joaquin Valley, California, is an example of an agricultural landscape with a large diversity of field, vegetable, tree, nut, and citrus crops, but also confined animal feeding operations (CAFOs, here mostly dairies) that generate, store, and land apply large amounts of liquid manure. As in other such regions around the world, the rural population in the San Joaquin Valley relies almost exclusively on shallow domestic wells (≤ 150 m deep), of which many have been affected by nitrate. Variability in crops, soil type, and depth to groundwater contribute to large variability in nitrate occurrence across the underlying aquifer system. The role of these factors in controlling groundwater nitrate contamination levels is examined. Two hundred domestic wells were sampled in two sub-regions of the San Joaquin Valley, Stanislaus and Merced (Stan/Mer) and Tulare and Kings (Tul/Kings) Counties. Forty six percent of well water samples in Tul/Kings and 42% of well water samples in Stan/Mer exceeded the MCL for nitrate (10 mg/L NO3-N). For statistical analysis of nitrate contamination, 78 crop and landuse types were considered by grouping them into ten categories (CAFO, citrus, deciduous fruits and nuts, field crops, forage, native, pasture, truck crops, urban, and vineyards). Vadose zone thickness, soil type, well construction information, well proximity to dairies, and dominant landuse near the well were considered. In the Stan/Mer area, elevated nitrate levels in domestic wells most strongly correlate with the combination of very shallow (≤ 21 m) water table and the presence of either CAFO derived animal waste applications or deciduous fruit and nut crops (synthetic fertilizer applications). In Tulare County, statistical data indicate that elevated nitrate levels in domestic well water are most strongly associated with citrus orchards when located in areas with a very shallow (≤ 21 m) water table. Kings County had relatively few nitrate MCL exceedances in domestic wells, probably due to the deeper water table in Kings County.

Unstable vicinal crystal growth from cellular automata

NASA Astrophysics Data System (ADS)

Krasteva, A.; Popova, H.; KrzyŻewski, F.; Załuska-Kotur, M.; Tonchev, V.

2016-03-01

In order to study the unstable step motion on vicinal crystal surfaces we devise vicinal Cellular Automata. Each cell from the colony has value equal to its height in the vicinal, initially the steps are regularly distributed. Another array keeps the adatoms, initially distributed randomly over the surface. The growth rule defines that each adatom at right nearest neighbor position to a (multi-) step attaches to it. The update of whole colony is performed at once and then time increases. This execution of the growth rule is followed by compensation of the consumed particles and by diffusional update(s) of the adatom population. Two principal sources of instability are employed - biased diffusion and infinite inverse Ehrlich-Schwoebel barrier (iiSE). Since these factors are not opposed by step-step repulsion the formation of multi-steps is observed but in general the step bunches preserve a finite width. We monitor the developing surface patterns and quantify the observations by scaling laws with focus on the eventual transition from diffusion-limited to kinetics-limited phenomenon. The time-scaling exponent of the bunch size N is 1/2 for the case of biased diffusion and 1/3 for the case of iiSE. Additional distinction is possible based on the time-scaling exponents of the sizes of multi-step Nmulti, these are 0.36÷0.4 (for biased diffusion) and 1/4 (iiSE).

Comparing Multi-Step IMAC and Multi-Step TiO2 Methods for Phosphopeptide Enrichment

PubMed Central

Yue, Xiaoshan; Schunter, Alissa; Hummon, Amanda B.

2016-01-01

Phosphopeptide enrichment from complicated peptide mixtures is an essential step for mass spectrometry-based phosphoproteomic studies to reduce sample complexity and ionization suppression effects. Typical methods for enriching phosphopeptides include immobilized metal affinity chromatography (IMAC) or titanium dioxide (TiO2) beads, which have selective affinity and can interact with phosphopeptides. In this study, the IMAC enrichment method was compared with the TiO2 enrichment method, using a multi-step enrichment strategy from whole cell lysate, to evaluate their abilities to enrich for different types of phosphopeptides. The peptide-to-beads ratios were optimized for both IMAC and TiO2 beads. Both IMAC and TiO2 enrichments were performed for three rounds to enable the maximum extraction of phosphopeptides from the whole cell lysates. The phosphopeptides that are unique to IMAC enrichment, unique to TiO2 enrichment, and identified with both IMAC and TiO2 enrichment were analyzed for their characteristics. Both IMAC and TiO2 enriched similar amounts of phosphopeptides with comparable enrichment efficiency. However, phosphopeptides that are unique to IMAC enrichment showed a higher percentage of multi-phosphopeptides, as well as a higher percentage of longer, basic, and hydrophilic phosphopeptides. Also, the IMAC and TiO2 procedures clearly enriched phosphopeptides with different motifs. Finally, further enriching with two rounds of TiO2 from the supernatant after IMAC enrichment, or further enriching with two rounds of IMAC from the supernatant TiO2 enrichment does not fully recover the phosphopeptides that are not identified with the corresponding multi-step enrichment. PMID:26237447

Multi-contrast MRI registration of carotid arteries based on cross-sectional images and lumen boundaries

NASA Astrophysics Data System (ADS)

Wu, Yu-Xia; Zhang, Xi; Xu, Xiao-Pan; Liu, Yang; Zhang, Guo-Peng; Li, Bao-Juan; Chen, Hui-Jun; Lu, Hong-Bing

2017-02-01

Ischemic stroke has great correlation with carotid atherosclerosis and is mostly caused by vulnerable plaques. It's particularly important to analysis the components of plaques for the detection of vulnerable plaques. Recently plaque analysis based on multi-contrast magnetic resonance imaging has attracted great attention. Though multi-contrast MR imaging has potentials in enhanced demonstration of carotid wall, its performance is hampered by the misalignment of different imaging sequences. In this study, a coarse-to-fine registration strategy based on cross-sectional images and wall boundaries is proposed to solve the problem. It includes two steps: a rigid step using the iterative closest points to register the centerlines of carotid artery extracted from multi-contrast MR images, and a non-rigid step using the thin plate spline to register the lumen boundaries of carotid artery. In the rigid step, the centerline was extracted by tracking the crosssectional images along the vessel direction calculated by Hessian matrix. In the non-rigid step, a shape context descriptor is introduced to find corresponding points of two similar boundaries. In addition, the deterministic annealing technique is used to find a globally optimized solution. The proposed strategy was evaluated by newly developed three-dimensional, fast and high resolution multi-contrast black blood MR imaging. Quantitative validation indicated that after registration, the overlap of two boundaries from different sequences is 95%, and their mean surface distance is 0.12 mm. In conclusion, the proposed algorithm has improved the accuracy of registration effectively for further component analysis of carotid plaques.

Self-Regulated Strategy Development Instruction for Teaching Multi-Step Equations to Middle School Students Struggling in Math

ERIC Educational Resources Information Center

Cuenca-Carlino, Yojanna; Freeman-Green, Shaqwana; Stephenson, Grant W.; Hauth, Clara

2016-01-01

Six middle school students identified as having a specific learning disability or at risk for mathematical difficulties were taught how to solve multi-step equations by using the self-regulated strategy development (SRSD) model of instruction. A multiple-probe-across-pairs design was used to evaluate instructional effects. Instruction was provided…

Age and gender estimation using Region-SIFT and multi-layered SVM

NASA Astrophysics Data System (ADS)

Kim, Hyunduk; Lee, Sang-Heon; Sohn, Myoung-Kyu; Hwang, Byunghun

2018-04-01

In this paper, we propose an age and gender estimation framework using the region-SIFT feature and multi-layered SVM classifier. The suggested framework entails three processes. The first step is landmark based face alignment. The second step is the feature extraction step. In this step, we introduce the region-SIFT feature extraction method based on facial landmarks. First, we define sub-regions of the face. We then extract SIFT features from each sub-region. In order to reduce the dimensions of features we employ a Principal Component Analysis (PCA) and a Linear Discriminant Analysis (LDA). Finally, we classify age and gender using a multi-layered Support Vector Machines (SVM) for efficient classification. Rather than performing gender estimation and age estimation independently, the use of the multi-layered SVM can improve the classification rate by constructing a classifier that estimate the age according to gender. Moreover, we collect a dataset of face images, called by DGIST_C, from the internet. A performance evaluation of proposed method was performed with the FERET database, CACD database, and DGIST_C database. The experimental results demonstrate that the proposed approach classifies age and performs gender estimation very efficiently and accurately.

The Relationship Between Non-Symbolic Multiplication and Division in Childhood

PubMed Central

McCrink, Koleen; Shafto, Patrick; Barth, Hilary

2016-01-01

Children without formal education in addition and subtraction are able to perform multi-step operations over an approximate number of objects. Further, their performance improves when solving approximate (but not exact) addition and subtraction problems that allow for inversion as a shortcut (e.g., a + b − b = a). The current study examines children’s ability to perform multi-step operations, and the potential for an inversion benefit, for the operations of approximate, non-symbolic multiplication and division. Children were trained to compute a multiplication and division scaling factor (*2 or /2, *4 or /4), and then tested on problems that combined two of these factors in a way that either allowed for an inversion shortcut (e.g., 8 * 4 / 4) or did not (e.g., 8 * 4 / 2). Children’s performance was significantly better than chance for all scaling factors during training, and they successfully computed the outcomes of the multi-step testing problems. They did not exhibit a performance benefit for problems with the a * b / b structure, suggesting they did not draw upon inversion reasoning as a logical shortcut to help them solve the multi-step test problems. PMID:26880261

Pulsed depressed collector

DOEpatents

Kemp, Mark A

2015-11-03

A high power RF device has an electron beam cavity, a modulator, and a circuit for feed-forward energy recovery from a multi-stage depressed collector to the modulator. The electron beam cavity include a cathode, an anode, and the multi-stage depressed collector, and the modulator is configured to provide pulses to the cathode. Voltages of the electrode stages of the multi-stage depressed collector are allowed to float as determined by fixed impedances seen by the electrode stages. The energy recovery circuit includes a storage capacitor that dynamically biases potentials of the electrode stages of the multi-stage depressed collector and provides recovered energy from the electrode stages of the multi-stage depressed collector to the modulator. The circuit may also include a step-down transformer, where the electrode stages of the multi-stage depressed collector are electrically connected to separate taps on the step-down transformer.

Multi-step optimization strategy for fuel-optimal orbital transfer of low-thrust spacecraft

NASA Astrophysics Data System (ADS)

Rasotto, M.; Armellin, R.; Di Lizia, P.

2016-03-01

An effective method for the design of fuel-optimal transfers in two- and three-body dynamics is presented. The optimal control problem is formulated using calculus of variation and primer vector theory. This leads to a multi-point boundary value problem (MPBVP), characterized by complex inner constraints and a discontinuous thrust profile. The first issue is addressed by embedding the MPBVP in a parametric optimization problem, thus allowing a simplification of the set of transversality constraints. The second problem is solved by representing the discontinuous control function by a smooth function depending on a continuation parameter. The resulting trajectory optimization method can deal with different intermediate conditions, and no a priori knowledge of the control structure is required. Test cases in both the two- and three-body dynamics show the capability of the method in solving complex trajectory design problems.

Parallel Monte Carlo transport modeling in the context of a time-dependent, three-dimensional multi-physics code

DOE Office of Scientific and Technical Information (OSTI.GOV)

Procassini, R.J.

1997-12-31

The fine-scale, multi-space resolution that is envisioned for accurate simulations of complex weapons systems in three spatial dimensions implies flop-rate and memory-storage requirements that will only be obtained in the near future through the use of parallel computational techniques. Since the Monte Carlo transport models in these simulations usually stress both of these computational resources, they are prime candidates for parallelization. The MONACO Monte Carlo transport package, which is currently under development at LLNL, will utilize two types of parallelism within the context of a multi-physics design code: decomposition of the spatial domain across processors (spatial parallelism) and distribution ofmore » particles in a given spatial subdomain across additional processors (particle parallelism). This implementation of the package will utilize explicit data communication between domains (message passing). Such a parallel implementation of a Monte Carlo transport model will result in non-deterministic communication patterns. The communication of particles between subdomains during a Monte Carlo time step may require a significant level of effort to achieve a high parallel efficiency.« less

High temperature thermochromic polydiacetylenes: Design and colorimetric properties

NASA Astrophysics Data System (ADS)

Huo, Jingpei; Hu, Zhudong; He, Guozhang; Hong, Xiaxiao; Yang, Zhihao; Luo, Shihe; Ye, Xiufang; Li, Yanli; Zhang, Yubo; Zhang, Min; Chen, Hong; Fan, Ting; Zhang, Yuyuan; Xiong, Bangyun; Wang, Zhaoyang; Zhu, Zhibo; Chen, Dongchu

2017-11-01

Three novel polydiacetylenes (PDAs) are synthesized through the self-assembly followed by the topochemical polymerization via controllable electrophoretic deposition. All the samples could undergo a multi-step thermochromic process, turning purple and red successively over a wide range from room temperature to above 250 °C. Resulting PDAs are studied by UV-vis, IR, Raman spectroscopies, and chromoisomerism by naked eye visualization; their stabilities by thermogravimetric method, and emission behavior by fluorescence spectroscopy. To study the mechanism of the thermochromic response, temperature-dependent UV-vis spectra, the results of which successfully highlighted the close relationship between chromatic transitions and the conformational changes.

Multi-step-ahead Method for Wind Speed Prediction Correction Based on Numerical Weather Prediction and Historical Measurement Data

NASA Astrophysics Data System (ADS)

Wang, Han; Yan, Jie; Liu, Yongqian; Han, Shuang; Li, Li; Zhao, Jing

2017-11-01

Increasing the accuracy of wind speed prediction lays solid foundation to the reliability of wind power forecasting. Most traditional correction methods for wind speed prediction establish the mapping relationship between wind speed of the numerical weather prediction (NWP) and the historical measurement data (HMD) at the corresponding time slot, which is free of time-dependent impacts of wind speed time series. In this paper, a multi-step-ahead wind speed prediction correction method is proposed with consideration of the passing effects from wind speed at the previous time slot. To this end, the proposed method employs both NWP and HMD as model inputs and the training labels. First, the probabilistic analysis of the NWP deviation for different wind speed bins is calculated to illustrate the inadequacy of the traditional time-independent mapping strategy. Then, support vector machine (SVM) is utilized as example to implement the proposed mapping strategy and to establish the correction model for all the wind speed bins. One Chinese wind farm in northern part of China is taken as example to validate the proposed method. Three benchmark methods of wind speed prediction are used to compare the performance. The results show that the proposed model has the best performance under different time horizons.

Both hands at work: the effect of aging on upper-limb kinematics in a multi-step activity of daily living.

PubMed

Gulde, Philipp; Hermsdörfer, Joachim

2017-05-01

The kinematic performance of basic motor tasks shows a clear decrease with advancing age. This study examined if the rules known from such tasks can be generalized to activities of daily living. We examined the end-effector kinematics of 13 young and 13 elderly participants in the multi-step activity of daily living of tea-making. Furthermore, we analyzed bimanual behavior and hand dominance in the task using different conditions of execution. The elderly sample took substantially longer to complete the activity (almost 50%) with longer trajectories compared with the young sample. Models of multiple linear regression revealed that the longer trajectories prolonged the trial duration in both groups, and while movement speed influenced the trial duration of young participants, phases of inactivity negatively affected how long the activity took the elderly subjects. No differences were found regarding bimanual performance or hand dominance. We assume that in self-paced activities of daily living, the age-dependent differences in the kinematics are more likely to be based on the higher cognitive demands of the task rather than on pure motor capability. Furthermore, it seems that not all of the rules known from basic motor tasks can be generalized to activities of daily living.

A Study on Segmented Multiple-Step Forming of Doubly Curved Thick Plate by Reconfigurable Multi-Punch Dies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ko, Young Ho; Han, Myoung Soo; Han, Jong Man

2007-05-17

Doubly curved thick plate forming in shipbuilding industries is currently performed by a thermal forming process, called as Line Heating by using gas flame torches. Due to the empirical manual work of it, the industries are eager for an alternative way to manufacture curved thick plates for ships. It was envisaged in this study to manufacture doubly curved thick plates by the multi-punch die forming. Experiments and finite element analyses were conducted to evaluate the feasibility of the reconfigurable discrete die forming to the thick plates. Single and segmented multiple step forming procedures were considered from both forming efficiency andmore » accuracy. Configuration of the multi-punch dies suitable for the segmented multiple step forming was also explored. As a result, Segmented multiple step forming with matched dies had a limited formability when the objective shapes become complicate, while a unmatched die configuration provided better possibility to manufacture large curved plates for ships.« less

Quantitative framework for ordered degradation of APC/C substrates.

PubMed

Lu, Dan; Girard, Juliet R; Li, Weihan; Mizrak, Arda; Morgan, David O

2015-11-16

During cell-cycle progression, substrates of a single master regulatory enzyme can be modified in a specific order. Here, we used experimental and computational approaches to dissect the quantitative mechanisms underlying the ordered degradation of the substrates of the ubiquitin ligase APC/C(Cdc20), a key regulator of chromosome segregation in mitosis. We show experimentally that the rate of catalysis varies with different substrates of APC/C(Cdc20). Using a computational model based on multi-step ubiquitination, we then show how changes in the interaction between a single substrate and APC/C(Cdc20) can alter the timing of degradation onset relative to APC/C(Cdc20) activation, while ensuring a fast degradation rate. Degradation timing and dynamics depend on substrate affinity for the enzyme as well as the catalytic rate at which the substrate is modified. When two substrates share the same pool of APC/C(Cdc20), their relative enzyme affinities and rates of catalysis influence the partitioning of APC/C(Cdc20) among substrates, resulting in substrate competition. Depending on how APC/C(Cdc20) is partitioned among its substrates, competition can have minor or major effects on the degradation of certain substrates. We show experimentally that increased expression of the early APC/C(Cdc20) substrate Clb5 does not delay the degradation of the later substrate securin, arguing against a role for competition with Clb5 in establishing securin degradation timing. The degradation timing of APC/C(Cdc20) substrates depends on the multi-step nature of ubiquitination, differences in substrate-APC/C(Cdc20) interactions, and competition among substrates. Our studies provide a conceptual framework for understanding how ordered modification can be established among substrates of the same regulatory enzyme, and facilitate our understanding of how precise temporal control is achieved by a small number of master regulators to ensure a successful cell division cycle.

First report of Maconellicoccus hirsutus (Green, 1908) (Hemiptera: Coccoidea: Pseudococcidae) and the associated parasitoid Anagyrus kamali Moursi, 1948 (Hymenoptera: Encyrtidae), in Brazil.

PubMed

Marsaro Júnior, A L; Peronti, A L B G; Penteado-Dias, A M; Morais, E G F; Pereira, P R V S

2013-05-01

The pink hibiscus mealybug (PHM), Maconellicoccus hirsutus (Green) (Hemiptera: Pseudococcidae) and the associated hymenopterous parasitoid, Anagyrus kamali Moursi, 1948 (Hymenoptera: Encyrtidae), are reported for the first time in Brazil. Specimens of the PHM were collected on nine hosts plants, Annona muricata L. (Anonnaceae), Glycine max (L.) Merr. (Fabaceae), Centrolobium paraensis Tul. (Fabaceae), Inga edulis Mart. (Fabaceae), Hibiscus rosa-sinensis L. (Malvaceae), Psidium guajava L. (Myrtaceae), Averrhoa carambola L. (Oxalidaceae), Citrus sinensis (L.) Osbeck (Rutaceae) and Solanum lycopersicum L. (Solanaceae), in four municipalities in the north-northeast of the state of Roraima. The plants C. paraensis, I. edulis and C. sinensis are recorded for the first time as a hosts for PHM. Characteristic injuries observed on the host plants infested by PHM and suggestions for its management are presented.

Continuous Video Modeling to Assist with Completion of Multi-Step Home Living Tasks by Young Adults with Moderate Intellectual Disability

ERIC Educational Resources Information Center

Mechling, Linda C.; Ayres, Kevin M.; Bryant, Kathryn J.; Foster, Ashley L.

2014-01-01

The current study evaluated a relatively new video-based procedure, continuous video modeling (CVM), to teach multi-step cleaning tasks to high school students with moderate intellectual disability. CVM in contrast to video modeling and video prompting allows repetition of the video model (looping) as many times as needed while the user completes…

Maoism in India

DTIC Science & Technology

2010-03-24

COIN response contributed to the movement’s growth. Conclusion: A multi-pronged COIN strategy that combines the use of force with concrete steps to...excesses provided the spark that tumed the agitation into a conflagration of a violent struggle. The resultant violence soon spread to other areas and...coordinate a comprehensive COIN approach against the Maoists. A multi-pronged COIN strategy that combines the use of force with concrete steps to

Immobilised enzyme microreactor for screening of multi-step bioconversions: characterisation of a de novo transketolase-ω-transaminase pathway to synthesise chiral amino alcohols.

PubMed

Matosevic, S; Lye, G J; Baganz, F

2011-09-20

Complex molecules are synthesised via a number of multi-step reactions in living cells. In this work, we describe the development of a continuous flow immobilized enzyme microreactor platform for use in evaluation of multi-step bioconversion pathways demonstrating a de novo transketolase/ω-transaminase-linked asymmetric amino alcohol synthesis. The prototype dual microreactor is based on the reversible attachment of His₆-tagged enzymes via Ni-NTA linkage to two surface derivatised capillaries connected in series. Kinetic parameters established for the model transketolase (TK)-catalysed conversion of lithium-hydroxypyruvate (Li-HPA) and glycolaldehyde (GA) to L-erythrulose using a continuous flow system with online monitoring of reaction output was in good agreement with kinetic parameters determined for TK in stop-flow mode. By coupling the transketolase catalysed chiral ketone forming reaction with the biocatalytic addition of an amine to the TK product using a transaminase (ω-TAm) it is possible to generate chiral amino alcohols from achiral starting compounds. We demonstrated this in a two-step configuration, where the TK reaction was followed by the ω-TAm-catalysed amination of L-erythrulose to synthesise 2-amino-1,3,4-butanetriol (ABT). Synthesis of the ABT product via the dual reaction and the on-line monitoring of each component provided a full profile of the de novo two-step bioconversion and demonstrated the utility of this microreactor system to provide in vitro multi-step pathway evaluation. Copyright © 2011 Elsevier B.V. All rights reserved.

The role of Myc-induced protein synthesis in cancer

PubMed Central

Ruggero, Davide

2009-01-01

Deregulation in different steps of translational control is an emerging mechanism for cancer formation. One example of an oncogene with a direct role in control of translation is the Myc transcription factor. Myc directly increases protein synthesis rates by controlling the expression of multiple components of the protein synthetic machinery, including ribosomal proteins, initiation factors of translation, Pol III and rDNA. However, the contribution of Myc-dependent increases in protein synthesis towards the multi-step process leading to cancer has remained unknown. Recent evidence strongly suggests that Myc oncogenic signaling may monopolize the translational machinery to elicit cooperative effects on cell growth, cell cycle progression, and genome instability as a mechanism for cancer initiation. Moreover, new genetic tools to restore aberrant increases in protein synthesis control are now available, which should enable the dissection of important mechanisms in cancer that rely on the translational machinery. PMID:19934336

A higher-speed compressive sensing camera through multi-diode design

NASA Astrophysics Data System (ADS)

Herman, Matthew A.; Tidman, James; Hewitt, Donna; Weston, Tyler; McMackin, Lenore

2013-05-01

Obtaining high frame rates is a challenge with compressive sensing (CS) systems that gather measurements in a sequential manner, such as the single-pixel CS camera. One strategy for increasing the frame rate is to divide the FOV into smaller areas that are sampled and reconstructed in parallel. Following this strategy, InView has developed a multi-aperture CS camera using an 8×4 array of photodiodes that essentially act as 32 individual simultaneously operating single-pixel cameras. Images reconstructed from each of the photodiode measurements are stitched together to form the full FOV. To account for crosstalk between the sub-apertures, novel modulation patterns have been developed to allow neighboring sub-apertures to share energy. Regions of overlap not only account for crosstalk energy that would otherwise be reconstructed as noise, but they also allow for tolerance in the alignment of the DMD to the lenslet array. Currently, the multi-aperture camera is built into a computational imaging workstation configuration useful for research and development purposes. In this configuration, modulation patterns are generated in a CPU and sent to the DMD via PCI express, which allows the operator to develop and change the patterns used in the data acquisition step. The sensor data is collected and then streamed to the workstation via an Ethernet or USB connection for the reconstruction step. Depending on the amount of data taken and the amount of overlap between sub-apertures, frame rates of 2-5 frames per second can be achieved. In a stand-alone camera platform, currently in development, pattern generation and reconstruction will be implemented on-board.

Temperature dependence of frequency dispersion in III–V metal-oxide-semiconductor C-V and the capture/emission process of border traps

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vais, Abhitosh, E-mail: Abhitosh.Vais@imec.be; Martens, Koen; DeMeyer, Kristin

2015-08-03

This paper presents a detailed investigation of the temperature dependence of frequency dispersion observed in capacitance-voltage (C-V) measurements of III-V metal-oxide-semiconductor (MOS) devices. The dispersion in the accumulation region of the capacitance data is found to change from 4%–9% (per decade frequency) to ∼0% when the temperature is reduced from 300 K to 4 K in a wide range of MOS capacitors with different gate dielectrics and III-V substrates. We show that such significant temperature dependence of C-V frequency dispersion cannot be due to the temperature dependence of channel electrostatics, i.e., carrier density and surface potential. We also show that the temperaturemore » dependence of frequency dispersion, and hence, the capture/emission process of border traps can be modeled by a combination of tunneling and a “temperature-activated” process described by a non-radiative multi-phonon model, instead of a widely believed single-step elastic tunneling process.« less

PLE in the analysis of plant compounds. Part II: One-cycle PLE in determining total amount of analyte in plant material.

PubMed

Dawidowicz, Andrzej L; Wianowska, Dorota

2005-04-29

Pressurised liquid extraction (PLE) is recognised as one of the most effective sample preparation methods. Despite the enhanced extraction power of PLE, the full recovery of an analyte from plant material may require multiple extractions of the same sample. The presented investigations show the possibility of estimating the true concentration value of an analyte in plant material employing one-cycle PLE in which plant samples of different weight are used. The performed experiments show a linear dependence between the reciprocal value of the analyte amount (E*), extracted in single-step PLE from a plant matrix, and the ratio of plant material mass to extrahent volume (m(p)/V(s)). Hence, time-consuming multi-step PLE can be replaced by a few single-step PLEs performed at different (m(p)/V(s)) ratios. The concentrations of rutin in Sambucus nigra L. and caffeine in tea and coffee estimated by means of the tested procedure are almost the same as their concentrations estimated by multiple PLE.

Mechanical Behavior of Brittle Rock-Like Specimens with Pre-existing Fissures Under Uniaxial Loading: Experimental Studies and Particle Mechanics Approach

NASA Astrophysics Data System (ADS)

Cao, Ri-hong; Cao, Ping; Lin, Hang; Pu, Cheng-zhi; Ou, Ke

2016-03-01

Joints and fissures with similar orientation or characteristics are common in natural rocks; the inclination and density of the fissures affect the mechanical properties and failure mechanism of the rock mass. However, the strength, crack coalescence pattern, and failure mode of rock specimens containing multi-fissures have not been studied comprehensively. In this paper, combining similar material testing and discrete element numerical method (PFC2D), the peak strength and failure characteristics of rock-like materials with multi-fissures are explored. Rock-like specimens were made of cement and sand and pre-existing fissures created by inserting steel shims into cement mortar paste and removing them during curing. The peak strength of multi-fissure specimens depends on the fissure angle α (which is measured counterclockwise from horizontal) and fissure number ( N f). Under uniaxial compressional loading, the peak strength increased with increasing α. The material strength was lowest for α = 25°, and highest for α = 90°. The influence of N f on the peak strength depended on α. For α = 25° and 45°, N f had a strong effect on the peak strength, while for higher α values, especially for the 90° sample, there were no obvious changes in peak strength with different N f. Under uniaxial compression, the coalescence modes between the fissures can be classified into three categories: S-mode, T-mode, and M-mode. Moreover, the failure mode can be classified into four categories: mixed failure, shear failure, stepped path failure, and intact failure. The failure mode of the specimen depends on α and N f. The peak strength and failure modes in the numerically simulated and experimental results are in good agreement.

Region-based multi-step optic disk and cup segmentation from color fundus image

NASA Astrophysics Data System (ADS)

Xiao, Di; Lock, Jane; Manresa, Javier Moreno; Vignarajan, Janardhan; Tay-Kearney, Mei-Ling; Kanagasingam, Yogesan

2013-02-01

Retinal optic cup-disk-ratio (CDR) is a one of important indicators of glaucomatous neuropathy. In this paper, we propose a novel multi-step 4-quadrant thresholding method for optic disk segmentation and a multi-step temporal-nasal segmenting method for optic cup segmentation based on blood vessel inpainted HSL lightness images and green images. The performance of the proposed methods was evaluated on a group of color fundus images and compared with the manual outlining results from two experts. Dice scores of detected disk and cup regions between the auto and manual results were computed and compared. Vertical CDRs were also compared among the three results. The preliminary experiment has demonstrated the robustness of the method for automatic optic disk and cup segmentation and its potential value for clinical application.

Model predictive control design for polytopic uncertain systems by synthesising multi-step prediction scenarios

NASA Astrophysics Data System (ADS)

Lu, Jianbo; Xi, Yugeng; Li, Dewei; Xu, Yuli; Gan, Zhongxue

2018-01-01

A common objective of model predictive control (MPC) design is the large initial feasible region, low online computational burden as well as satisfactory control performance of the resulting algorithm. It is well known that interpolation-based MPC can achieve a favourable trade-off among these different aspects. However, the existing results are usually based on fixed prediction scenarios, which inevitably limits the performance of the obtained algorithms. So by replacing the fixed prediction scenarios with the time-varying multi-step prediction scenarios, this paper provides a new insight into improvement of the existing MPC designs. The adopted control law is a combination of predetermined multi-step feedback control laws, based on which two MPC algorithms with guaranteed recursive feasibility and asymptotic stability are presented. The efficacy of the proposed algorithms is illustrated by a numerical example.

A linearly frequency-swept high-speed-rate multi-wavelength laser for optical coherence tomography

NASA Astrophysics Data System (ADS)

Wang, Qiyu; Wang, Zhaoying; Yuan, Quan; Ma, Rui; Du, Tao; Yang, Tianxin

2017-02-01

We proposed and demonstrated a linearly frequency-swept multi-wavelength laser source for optical coherence tomography (OCT) eliminating the need of wavenumber space resampling in the postprocessing progress. The source consists of a multi-wavelength fiber laser source (MFS) and an optical sweeping loop. In this novel laser source, an equally spaced multi-wavelength laser is swept simultaneously by a certain step each time in the frequency domain in the optical sweeping loop. The sweeping step is determined by radio frequency (RF) signal which can be precisely controlled. Thus the sweeping behavior strictly maintains a linear relationship between time and frequency. We experimentally achieved linear time-frequency sweeping at a sweeping rate of 400 kHz with our laser source.

Accurate identification of microseismic P- and S-phase arrivals using the multi-step AIC algorithm

NASA Astrophysics Data System (ADS)

Zhu, Mengbo; Wang, Liguan; Liu, Xiaoming; Zhao, Jiaxuan; Peng, Ping'an

2018-03-01

Identification of P- and S-phase arrivals is the primary work in microseismic monitoring. In this study, a new multi-step AIC algorithm is proposed. This algorithm consists of P- and S-phase arrival pickers (P-picker and S-picker). The P-picker contains three steps: in step 1, a preliminary P-phase arrival window is determined by the waveform peak. Then a preliminary P-pick is identified using the AIC algorithm. Finally, the P-phase arrival window is narrowed based on the above P-pick. Thus the P-phase arrival can be identified accurately by using the AIC algorithm again. The S-picker contains five steps: in step 1, a narrow S-phase arrival window is determined based on the P-pick and the AIC curve of amplitude biquadratic time-series. In step 2, the S-picker automatically judges whether the S-phase arrival is clear to identify. In step 3 and 4, the AIC extreme points are extracted, and the relationship between the local minimum and the S-phase arrival is researched. In step 5, the S-phase arrival is picked based on the maximum probability criterion. To evaluate of the proposed algorithm, a P- and S-picks classification criterion is also established based on a source location numerical simulation. The field data tests show a considerable improvement of the multi-step AIC algorithm in comparison with the manual picks and the original AIC algorithm. Furthermore, the technique is independent of the kind of SNR. Even in the poor-quality signal group which the SNRs are below 5, the effective picking rates (the corresponding location error is <15 m) of P- and S-phase arrivals are still up to 80.9% and 76.4% respectively.

Rotational paper-based electrochemiluminescence immunodevices for sensitive and multiplexed detection of cancer biomarkers.

PubMed

Sun, Xiange; Li, Bowei; Tian, Chunyuan; Yu, Fabiao; Zhou, Na; Zhan, Yinghua; Chen, Lingxin

2018-05-12

This paper describes a novel rotational paper-based analytical device (RPAD) to implement multi-step electrochemiluminescence (ECL) immunoassays. The integrated paper-based rotational valves can be easily controlled by rotating paper discs manually and this advantage makes it user-friendly to untrained users to carry out the multi-step assays. In addition, the rotational valves are reusable and the response time can be shortened to several seconds, which promotes the rotational paper-based device to have great advantages in multi-step operations. Under the control of rotational valves, multi-step ECL immunoassays were conducted on the rotational device for the multiplexed detection of carcinoembryonic antigen (CEA) and prostate specific antigen (PSA). The rotational device exhibited excellent analytical performance for CEA and PSA, and they could be detected in the linear ranges of 0.1-100 ng mL -1 and 0.1-50 ng mL -1 with detection limits down to 0.07 ng mL -1 and 0.03 ng mL -1 , respectively, which were within the ranges of clinical concentrations. We hope this technique will open a new avenue for the fabrication of paper-based valves and provide potential application in clinical diagnostics. Copyright © 2017 Elsevier B.V. All rights reserved.

Contaminant source and release history identification in groundwater: A multi-step approach

NASA Astrophysics Data System (ADS)

Gzyl, G.; Zanini, A.; Frączek, R.; Kura, K.

2014-02-01

The paper presents a new multi-step approach aiming at source identification and release history estimation. The new approach consists of three steps: performing integral pumping tests, identifying sources, and recovering the release history by means of a geostatistical approach. The present paper shows the results obtained from the application of the approach within a complex case study in Poland in which several areal sources were identified. The investigated site is situated in the vicinity of a former chemical plant in southern Poland in the city of Jaworzno in the valley of the Wąwolnica River; the plant has been in operation since the First World War producing various chemicals. From an environmental point of view the most relevant activity was the production of pesticides, especially lindane. The application of the multi-step approach enabled a significant increase in the knowledge of contamination at the site. Some suspected contamination sources have been proven to have minor effect on the overall contamination. Other suspected sources have been proven to have key significance. Some areas not taken into consideration previously have now been identified as key sources. The method also enabled estimation of the magnitude of the sources and, a list of the priority reclamation actions will be drawn as a result. The multi-step approach has proven to be effective and may be applied to other complicated contamination cases. Moreover, the paper shows the capability of the geostatistical approach to manage a complex real case study.

CORRECTING FOR INTERSTELLAR SCATTERING DELAY IN HIGH-PRECISION PULSAR TIMING: SIMULATION RESULTS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Palliyaguru, Nipuni; McLaughlin, Maura; Stinebring, Daniel

2015-12-20

Light travel time changes due to gravitational waves (GWs) may be detected within the next decade through precision timing of millisecond pulsars. Removal of frequency-dependent interstellar medium (ISM) delays due to dispersion and scattering is a key issue in the detection process. Current timing algorithms routinely correct pulse times of arrival (TOAs) for time-variable delays due to cold plasma dispersion. However, none of the major pulsar timing groups correct for delays due to scattering from multi-path propagation in the ISM. Scattering introduces a frequency-dependent phase change in the signal that results in pulse broadening and arrival time delays. Any methodmore » to correct the TOA for interstellar propagation effects must be based on multi-frequency measurements that can effectively separate dispersion and scattering delay terms from frequency-independent perturbations such as those due to a GW. Cyclic spectroscopy, first described in an astronomical context by Demorest (2011), is a potentially powerful tool to assist in this multi-frequency decomposition. As a step toward a more comprehensive ISM propagation delay correction, we demonstrate through a simulation that we can accurately recover impulse response functions (IRFs), such as those that would be introduced by multi-path scattering, with a realistic signal-to-noise ratio (S/N). We demonstrate that timing precision is improved when scatter-corrected TOAs are used, under the assumptions of a high S/N and highly scattered signal. We also show that the effect of pulse-to-pulse “jitter” is not a serious problem for IRF reconstruction, at least for jitter levels comparable to those observed in several bright pulsars.« less

Reynolds-averaged Navier-Stokes based ice accretion for aircraft wings

NASA Astrophysics Data System (ADS)

Lashkajani, Kazem Hasanzadeh

This thesis addresses one of the current issues in flight safety towards increasing icing simulation capabilities for prediction of complex 2D and 3D glaze ice shapes over aircraft surfaces. During the 1980's and 1990's, the field of aero-icing was established to support design and certification of aircraft flying in icing conditions. The multidisciplinary technologies used in such codes were: aerodynamics (panel method), droplet trajectory calculations (Lagrangian framework), thermodynamic module (Messinger model) and geometry module (ice accretion). These are embedded in a quasi-steady module to simulate the time-dependent ice accretion process (multi-step procedure). The objectives of the present research are to upgrade the aerodynamic module from Laplace to Reynolds-Average Navier-Stokes equations solver. The advantages are many. First, the physical model allows accounting for viscous effects in the aerodynamic module. Second, the solution of the aero-icing module directly provides the means for characterizing the aerodynamic effects of icing, such as loss of lift and increased drag. Third, the use of a finite volume approach to solving the Partial Differential Equations allows rigorous mesh and time convergence analysis. Finally, the approaches developed in 2D can be easily transposed to 3D problems. The research was performed in three major steps, each providing insights into the overall numerical approaches. The most important realization comes from the need to develop specific mesh generation algorithms to ensure feasible solutions in very complex multi-step aero-icing calculations. The contributions are presented in chronological order of their realization. First, a new framework for RANS based two-dimensional ice accretion code, CANICE2D-NS, is developed. A multi-block RANS code from U. of Liverpool (named PMB) is providing the aerodynamic field using the Spalart-Allmaras turbulence model. The ICEM-CFD commercial tool is used for the iced airfoil remeshing and field smoothing. The new coupling is fully automated and capable of multi-step ice accretion simulations via a quasi-steady approach. In addition, the framework allows for flow analysis and aerodynamic performance prediction of the iced airfoils. The convergence of the quasi-steady algorithm is verified and identifies the need for an order of magnitude increase in the number of multi-time steps in icing simulations to achieve solver independent solutions. Second, a Multi-Block Navier-Stokes code, NSMB, is coupled with the CANICE2D icing framework. Attention is paid to the roughness implementation of the ONERA roughness model within the Spalart-Allmaras turbulence model, and to the convergence of the steady and quasi-steady iterative procedure. Effects of uniform surface roughness in quasi-steady ice accretion simulation are analyzed through different validation test cases. The results of CANICE2D-NS show good agreement with experimental data both in terms of predicted ice shapes as well as aerodynamic analysis of predicted and experimental ice shapes. Third, an efficient single-block structured Navier-Stokes CFD code, NSCODE, is coupled with the CANICE2D-NS icing framework. Attention is paid to the roughness implementation of the Boeing model within the Spalart-Allmaras turbulence model, and to acceleration of the convergence of the steady and quasi-steady iterative procedures. Effects of uniform surface roughness in quasi-steady ice accretion simulation are analyzed through different validation test cases, including code to code comparisons with the same framework coupled with the NSMB Navier-Stokes solver. The efficiency of the J-multigrid approach to solve the flow equations on complex iced geometries is demonstrated. Since it was noted in all these calculations that the ICEM-CFD grid generation package produced a number of issues such as inefficient mesh quality and smoothing deficiencies (notably grid shocks), a fourth study proposes a new mesh generation algorithm. A PDE based multi-block structured grid generation code, NSGRID, is developed for this purpose. The study includes the developments of novel mesh generation algorithms over complex glaze ice shapes containing multi-curvature ice accretion geometries, such as single/double ice horns. The twofold approaches tackle surface geometry discretization as well as field mesh generation. An adaptive curvilinear curvature control algorithm is constructed solving a 1D elliptic PDE equation with periodic source terms. This method controls the arclength grid spacing so that high convex and concave curvature regions around ice horns are appropriately captured and is shown to effectively treat the grid shock problem. Then, a novel blended method is developed by defining combinations of source terms with 2D elliptic equations. The source terms include two common control functions, Sorenson and Spekreijse, and an additional third source term to improve orthogonality. This blended method is shown to be very effective for improving grid quality metrics for complex glaze ice meshes with RANS resolution. The performance in terms of residual reduction per non-linear iteration of several solution algorithms (Point-Jacobi, Gauss-Seidel, ADI, Point and Line SOR) are discussed within the context of a full Multi-grid operator. Details are given on the various formulations used in the linearization process. It is shown that the performance of the solution algorithm depends on the type of control function used. Finally, the algorithms are validated on standard complex experimental ice shapes, demonstrating the applicability of the methods. Finally, the automated framework of RANS based two-dimensional multi-step ice accretion, CANICE2D-NS is developed, coupled with a Multi-Block Navier-Stokes CFD code, NSCODE2D, a Multi-Block elliptic grid generation code, NSGRID2D, and a Multi-Block Eulerian droplet solver, NSDROP2D (developed at Polytechnique Montreal). The framework allows Lagrangian and Eulerian droplet computations within a chimera approach treating multi-elements geometries. The code was tested on public and confidential validation test cases including standard NATO cases. In addition, up to 10 times speedup is observed in the mesh generation procedure by using the implicit line SOR and ADI smoothers within a multigrid procedure. The results demonstrate the benefits and robustness of the new framework in predicting ice shapes and aerodynamic performance parameters.

Multi-step resistive switching behavior of Li-doped ZnO resistance random access memory device controlled by compliance current

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lin, Chun-Cheng; Department of Mathematic and Physical Sciences, R.O.C. Air Force Academy, Kaohsiung 820, Taiwan; Tang, Jian-Fu

2016-06-28

The multi-step resistive switching (RS) behavior of a unipolar Pt/Li{sub 0.06}Zn{sub 0.94}O/Pt resistive random access memory (RRAM) device is investigated. It is found that the RRAM device exhibits normal, 2-, 3-, and 4-step RESET behaviors under different compliance currents. The transport mechanism within the device is investigated by means of current-voltage curves, in-situ transmission electron microscopy, and electrochemical impedance spectroscopy. It is shown that the ion transport mechanism is dominated by Ohmic behavior under low electric fields and the Poole-Frenkel emission effect (normal RS behavior) or Li{sup +} ion diffusion (2-, 3-, and 4-step RESET behaviors) under high electric fields.

Fast dye salts provide fast access to azidoarene synthons in multi-step one-pot tandem click transformations

PubMed Central

Fletcher, James T.; Reilly, Jacquelline E.

2012-01-01

This study examined whether commercially available diazonium salts could be used as efficient aromatic azide precursors in one-pot multi-step click transformations. Seven different diazonium salts, including Fast Red RC, Fast Blue B, Fast Corinth V and Variamine Blue B were surveyed under aqueous click reaction conditions of CuSO4/Na ascorbate catalyst with 1:1 t-BuOH:H2O solvent. Two-step tandem reactions with terminal alkyne and diyne co-reactants led to 1,2,3-triazole products in 66%-88% yields, while three-step tandem reactions with trimethylsilyl-protected alkyne and diyne co-reactants led to 1,2,3-triazole products in 61%-78% yields. PMID:22368306

Multi-objective optimization for generating a weighted multi-model ensemble

NASA Astrophysics Data System (ADS)

Lee, H.

2017-12-01

Many studies have demonstrated that multi-model ensembles generally show better skill than each ensemble member. When generating weighted multi-model ensembles, the first step is measuring the performance of individual model simulations using observations. There is a consensus on the assignment of weighting factors based on a single evaluation metric. When considering only one evaluation metric, the weighting factor for each model is proportional to a performance score or inversely proportional to an error for the model. While this conventional approach can provide appropriate combinations of multiple models, the approach confronts a big challenge when there are multiple metrics under consideration. When considering multiple evaluation metrics, it is obvious that a simple averaging of multiple performance scores or model ranks does not address the trade-off problem between conflicting metrics. So far, there seems to be no best method to generate weighted multi-model ensembles based on multiple performance metrics. The current study applies the multi-objective optimization, a mathematical process that provides a set of optimal trade-off solutions based on a range of evaluation metrics, to combining multiple performance metrics for the global climate models and their dynamically downscaled regional climate simulations over North America and generating a weighted multi-model ensemble. NASA satellite data and the Regional Climate Model Evaluation System (RCMES) software toolkit are used for assessment of the climate simulations. Overall, the performance of each model differs markedly with strong seasonal dependence. Because of the considerable variability across the climate simulations, it is important to evaluate models systematically and make future projections by assigning optimized weighting factors to the models with relatively good performance. Our results indicate that the optimally weighted multi-model ensemble always shows better performance than an arithmetic ensemble mean and may provide reliable future projections.

Automatic Structural Parcellation of Mouse Brain MRI Using Multi-Atlas Label Fusion

PubMed Central

Ma, Da; Cardoso, Manuel J.; Modat, Marc; Powell, Nick; Wells, Jack; Holmes, Holly; Wiseman, Frances; Tybulewicz, Victor; Fisher, Elizabeth; Lythgoe, Mark F.; Ourselin, Sébastien

2014-01-01

Multi-atlas segmentation propagation has evolved quickly in recent years, becoming a state-of-the-art methodology for automatic parcellation of structural images. However, few studies have applied these methods to preclinical research. In this study, we present a fully automatic framework for mouse brain MRI structural parcellation using multi-atlas segmentation propagation. The framework adopts the similarity and truth estimation for propagated segmentations (STEPS) algorithm, which utilises a locally normalised cross correlation similarity metric for atlas selection and an extended simultaneous truth and performance level estimation (STAPLE) framework for multi-label fusion. The segmentation accuracy of the multi-atlas framework was evaluated using publicly available mouse brain atlas databases with pre-segmented manually labelled anatomical structures as the gold standard, and optimised parameters were obtained for the STEPS algorithm in the label fusion to achieve the best segmentation accuracy. We showed that our multi-atlas framework resulted in significantly higher segmentation accuracy compared to single-atlas based segmentation, as well as to the original STAPLE framework. PMID:24475148

Composite-composite repair bond strength: effect of different adhesion primers.

PubMed

Tezvergil, A; Lassila, L V J; Vallittu, P K

2003-11-01

Recently, new products have been introduced to repair composite restorations that may be used as 'one-step' primers or monomers and silane compounds which are used separately as 'multi-step' primers. The aim of this study was to compare the shear bond strength of the new composite resin to aged composite, by using different adhesion primers. The substrates were particulate filler composite (Z250, 3M-ESPE), which was aged by boiling for 8 h and storing at 37 degrees C in water for 3 weeks. The aged substrate surfaces were wet-ground flat with 320-grit silicon carbide paper and subjected randomly (n=8) to either one-step adhesion primer: Compoconnect (CC) (Heraus Kulzer), or multi-step: Clearfil Repair (CF) (Kuraray) or an intermediate resin: Scothchbond Multi-purpose adhesive resin (3M-ESPE) according to the manufacturers' recommendations. Specimens with no surface treatment were used as control (C). New composite resin (Z250) was added to the substrate using 2 mm layer increments and light cured. The specimens were either water stored for 48 h or water stored for 24 h and then thermocycled for 6000 cycles. The shear bond strengths were measured with a crosshead speed of 1.0 mm/min using a universal testing machine. Data were analysed by two-way ANOVA and Tukey's post-hoc tests (p=0.05). All surface treatment methods showed significant difference compared to control (p<0.05). CF showed higher bond strength than CC and MP (p<0.05). Storage condition did not show a significant difference (p>0.05) in bond strength values. It was concluded that multi-step adhesion primer yielded higher bond strength compared to one-step primer or intermediate resin.

Integration of topological modification within the modeling of multi-physics systems: Application to a Pogo-stick

NASA Astrophysics Data System (ADS)

Abdeljabbar Kharrat, Nourhene; Plateaux, Régis; Miladi Chaabane, Mariem; Choley, Jean-Yves; Karra, Chafik; Haddar, Mohamed

2018-05-01

The present work tackles the modeling of multi-physics systems applying a topological approach while proceeding with a new methodology using a topological modification to the structure of systems. Then the comparison with the Magos' methodology is made. Their common ground is the use of connectivity within systems. The comparison and analysis of the different types of modeling show the importance of the topological methodology through the integration of the topological modification to the topological structure of a multi-physics system. In order to validate this methodology, the case of Pogo-stick is studied. The first step consists in generating a topological graph of the system. Then the connectivity step takes into account the contact with the ground. During the last step of this research; the MGS language (Modeling of General System) is used to model the system through equations. Finally, the results are compared to those obtained by MODELICA. Therefore, this proposed methodology may be generalized to model multi-physics systems that can be considered as a set of local elements.

The effects of multi-disciplinary psycho-social care on socio-economic problems in cancer patients: a cluster-randomized trial.

PubMed

Singer, Susanne; Roick, Julia; Meixensberger, Jürgen; Schiefke, Franziska; Briest, Susanne; Dietz, Andreas; Papsdorf, Kirsten; Mössner, Joachim; Berg, Thomas; Stolzenburg, Jens-Uwe; Niederwieser, Dietger; Keller, Annette; Kersting, Anette; Danker, Helge

2018-06-01

We examined whether multi-disciplinary stepped psycho-social care decreases financial problems and improves return-to-work in cancer patients. In a university hospital, wards were randomly allocated to either stepped or standard care. Stepped care comprised screening for financial problems, consultation between doctor and patient, and the provision of social service. Outcomes were financial problems at the time of discharge and return-to-work in patients < 65 years old half a year after baseline. The analysis employed mixed-effect multivariate regression modeling. Thirteen wards were randomized and 1012 patients participated (n = 570 in stepped care and n = 442 in standard care). Those who reported financial problems at baseline were less likely to have financial problems at discharge when they had received stepped care (odds ratio (OR) 0.2, 95% confidence interval (CI) 0.1, 0.7; p = 0.01). There was no evidence for an effect of stepped care on financial problems in patients without such problems at baseline (OR 1.1, CI 0.5, 2.6; p = 0.82). There were 399 patients < 65 years old who were not retired at baseline. In this group, there was no evidence for an effect of stepped care on being employed half a year after baseline (OR 0.7, CI 0.3, 2.0; p = 0.52). NCT01859429 CONCLUSIONS: Financial problems can be avoided more effectively with multi-disciplinary stepped psycho-social care than with standard care in patients who have such problems.

A WENO-Limited, ADER-DT, Finite-Volume Scheme for Efficient, Robust, and Communication-Avoiding Multi-Dimensional Transport

DOE Office of Scientific and Technical Information (OSTI.GOV)

Norman, Matthew R

2014-01-01

The novel ADER-DT time discretization is applied to two-dimensional transport in a quadrature-free, WENO- and FCT-limited, Finite-Volume context. Emphasis is placed on (1) the serial and parallel computational properties of ADER-DT and this framework and (2) the flexibility of ADER-DT and this framework in efficiently balancing accuracy with other constraints important to transport applications. This study demonstrates a range of choices for the user when approaching their specific application while maintaining good parallel properties. In this method, genuine multi-dimensionality, single-step and single-stage time stepping, strict positivity, and a flexible range of limiting are all achieved with only one parallel synchronizationmore » and data exchange per time step. In terms of parallel data transfers per simulated time interval, this improves upon multi-stage time stepping and post-hoc filtering techniques such as hyperdiffusion. This method is evaluated with standard transport test cases over a range of limiting options to demonstrate quantitatively and qualitatively what a user should expect when employing this method in their application.« less

SAMI: Sydney-AAO Multi-object Integral field spectrograph pipeline

NASA Astrophysics Data System (ADS)

Allen, J. T.; Green, A. W.; Fogarty, L. M. R.; Sharp, R.; Nielsen, J.; Konstantopoulos, I.; Taylor, E. N.; Scott, N.; Cortese, L.; Richards, S. N.; Croom, S.; Owers, M. S.; Bauer, A. E.; Sweet, S. M.; Bryant, J. J.

2014-07-01

The SAMI (Sydney-AAO Multi-object Integral field spectrograph) pipeline reduces data from the Sydney-AAO Multi-object Integral field spectrograph (SAMI) for the SAMI Galaxy Survey. The python code organizes SAMI data and, along with the AAO 2dfdr package, carries out all steps in the data reduction, from raw data to fully calibrated datacubes. The principal steps are: data management, use of 2dfdr to produce row-stacked spectra, flux calibration, correction for telluric absorption, removal of atmospheric dispersion, alignment of dithered exposures, and drizzling onto a regular output grid. Variance and covariance information is tracked throughout the pipeline. Some quality control routines are also included.

A Successful Attempt to Obtain the Linear Dependence Between One-Photon and Two-Photon Spectral Properties and Hammett Parameters of Various Aromatic Substituents in New π-Extended Asymmetric Organic Chromophores.

PubMed

Hu, Nvdan; Gong, Yulong; Wang, Xinchao; Lu, Yao; Peng, Guangyue; Yang, Long; Zhang, Shengtao; Luo, Ziping; Li, Hongru; Gao, Fang

2015-11-01

A series of new asymmetric chromophores containing aromatic substituents and possessing the excellent π-extension in space were prepared through multi-steps routes. One-photon and two-photon spectral properties of these new chromophores could be tuned by these substituents finely and simultaneously. The linear correlation of the wave numbers of the one-photon absorption and emission maxima to Hammett parameters of these substituents was presented. Near infrared two-photon absorption emission integrated areas of the target chromophores were correlated linearly to Hammett constants of these substituted groups.

Toward quantum plasmonic networks

DOE PAGES

Holtfrerich, M. W.; Dowran, M.; Davidson, R.; ...

2016-08-30

Here, we demonstrate the transduction of macroscopic quantum entanglement by independent, distant plasmonic structures embedded in separate thin silver films. In particular, we show that the plasmon-mediated transmission through each film conserves spatially dependent, entangled quantum images, opening the door for the implementation of parallel quantum protocols, super-resolution imaging, and quantum plasmonic sensing geometries at the nanoscale level. The conservation of quantum information by the transduction process shows that continuous variable multi-mode entanglement is momentarily transferred from entangled beams of light to the space-like separated, completely independent plasmonic structures, thus providing a first important step toward establishing a multichannel quantummore » network across separate solid-state substrates.« less

Conduction quantization in monolayer MoS2

NASA Astrophysics Data System (ADS)

Li, T. S.

2016-10-01

We study the ballistic conduction of a monolayer MoS2 subject to a spatially modulated magnetic field by using the Landauer-Buttiker formalism. The band structure depends sensitively on the field strength, and its change has profound influence on the electron conduction. The conductance is found to demonstrate multi-step behavior due to the discrete number of conduction channels. The sharp peak and rectangular structures of the conductance are stretched out as temperature increases, due to the thermal broadening of the derivative of the Fermi-Dirac distribution function. Finally, quantum behavior in the conductance of MoS2 can be observed at temperatures below 10 K.

CAPS and Munc13: CATCHRs that SNARE Vesicles.

PubMed

James, Declan J; Martin, Thomas F J

2013-12-04

CAPS (Calcium-dependent Activator Protein for Secretion, aka CADPS) and Munc13 (Mammalian Unc-13) proteins function to prime vesicles for Ca(2+)-triggered exocytosis in neurons and neuroendocrine cells. CAPS and Munc13 proteins contain conserved C-terminal domains that promote the assembly of SNARE complexes for vesicle priming. Similarities of the C-terminal domains of CAPS/Munc13 proteins with Complex Associated with Tethering Containing Helical Rods domains in multi-subunit tethering complexes (MTCs) have been reported. MTCs coordinate multiple interactions for SNARE complex assembly at constitutive membrane fusion steps. We review aspects of these diverse tethering and priming factors to identify common operating principles.

Nonlinear Conservation Laws and Finite Volume Methods

NASA Astrophysics Data System (ADS)

Leveque, Randall J.

Introduction Software Notation Classification of Differential Equations Derivation of Conservation Laws The Euler Equations of Gas Dynamics Dissipative Fluxes Source Terms Radiative Transfer and Isothermal Equations Multi-dimensional Conservation Laws The Shock Tube Problem Mathematical Theory of Hyperbolic Systems Scalar Equations Linear Hyperbolic Systems Nonlinear Systems The Riemann Problem for the Euler Equations Numerical Methods in One Dimension Finite Difference Theory Finite Volume Methods Importance of Conservation Form - Incorrect Shock Speeds Numerical Flux Functions Godunov's Method Approximate Riemann Solvers High-Resolution Methods Other Approaches Boundary Conditions Source Terms and Fractional Steps Unsplit Methods Fractional Step Methods General Formulation of Fractional Step Methods Stiff Source Terms Quasi-stationary Flow and Gravity Multi-dimensional Problems Dimensional Splitting Multi-dimensional Finite Volume Methods Grids and Adaptive Refinement Computational Difficulties Low-Density Flows Discrete Shocks and Viscous Profiles Start-Up Errors Wall Heating Slow-Moving Shocks Grid Orientation Effects Grid-Aligned Shocks Magnetohydrodynamics The MHD Equations One-Dimensional MHD Solving the Riemann Problem Nonstrict Hyperbolicity Stiffness The Divergence of B Riemann Problems in Multi-dimensional MHD Staggered Grids The 8-Wave Riemann Solver Relativistic Hydrodynamics Conservation Laws in Spacetime The Continuity Equation The 4-Momentum of a Particle The Stress-Energy Tensor Finite Volume Methods Multi-dimensional Relativistic Flow Gravitation and General Relativity References

Texas two-step: a framework for optimal multi-input single-output deconvolution.

PubMed

Neelamani, Ramesh; Deffenbaugh, Max; Baraniuk, Richard G

2007-11-01

Multi-input single-output deconvolution (MISO-D) aims to extract a deblurred estimate of a target signal from several blurred and noisy observations. This paper develops a new two step framework--Texas Two-Step--to solve MISO-D problems with known blurs. Texas Two-Step first reduces the MISO-D problem to a related single-input single-output deconvolution (SISO-D) problem by invoking the concept of sufficient statistics (SSs) and then solves the simpler SISO-D problem using an appropriate technique. The two-step framework enables new MISO-D techniques (both optimal and suboptimal) based on the rich suite of existing SISO-D techniques. In fact, the properties of SSs imply that a MISO-D algorithm is mean-squared-error optimal if and only if it can be rearranged to conform to the Texas Two-Step framework. Using this insight, we construct new wavelet- and curvelet-based MISO-D algorithms with asymptotically optimal performance. Simulated and real data experiments verify that the framework is indeed effective.

Report on Quality Control Review of Grant Thornton, LLP FY 2009 Single Audit of Concurrent Technologies Corporation

DTIC Science & Technology

2011-12-05

F t:deral Aw:uds IJ󈧏it. Jl~r fllllfifM> /Jltfoi7J/I’Ii ,md/1 pwmfttt’!J Jr/.tf••tf Jo / ht tul’lliTitf otlll/ tVJIIJj>/eknW nf //Ito rtft•du/t 1/J(J...1111/. f ht ll lld/111!’> IWI~<II’Cd !4 .t l/bt/1/~Jirb I~ •~>tfrlllll ( fi/11’(1/7>/d I rrllwnlt~gitJ’ omtrl/011 lf•.JIIII~fi!IIJI/1 ciiMI’il )iotJ...fiJI> tt’l’l<ll’ C1\\IHI T/JqmMIIti»Y/’fttl (i,mllrmti ’l’t~lllml.>~m · •ll•rtfilltl "’"’ "" mb,mwTit we;r ;Udtln 111 tvu, 6m ’,,m/ tl,tlrjlllr

Effect of genotyped cows in the reference population on the genomic evaluation of Holstein cattle.

PubMed

Uemoto, Y; Osawa, T; Saburi, J

2017-03-01

This study evaluated the dependence of reliability and prediction bias on the prediction method, the contribution of including animals (bulls or cows), and the genetic relatedness, when including genotyped cows in the progeny-tested bull reference population. We performed genomic evaluation using a Japanese Holstein population, and assessed the accuracy of genomic enhanced breeding value (GEBV) for three production traits and 13 linear conformation traits. A total of 4564 animals for production traits and 4172 animals for conformation traits were genotyped using Illumina BovineSNP50 array. Single- and multi-step methods were compared for predicting GEBV in genotyped bull-only and genotyped bull-cow reference populations. No large differences in realized reliability and regression coefficient were found between the two reference populations; however, a slight difference was found between the two methods for production traits. The accuracy of GEBV determined by single-step method increased slightly when genotyped cows were included in the bull reference population, but decreased slightly by multi-step method. A validation study was used to evaluate the accuracy of GEBV when 800 additional genotyped bulls (POPbull) or cows (POPcow) were included in the base reference population composed of 2000 genotyped bulls. The realized reliabilities of POPbull were higher than those of POPcow for all traits. For the gain of realized reliability over the base reference population, the average ratios of POPbull gain to POPcow gain for production traits and conformation traits were 2.6 and 7.2, respectively, and the ratios depended on heritabilities of the traits. For regression coefficient, no large differences were found between the results for POPbull and POPcow. Another validation study was performed to investigate the effect of genetic relatedness between cows and bulls in the reference and test populations. The effect of genetic relationship among bulls in the reference population was also assessed. The results showed that it is important to account for relatedness among bulls in the reference population. Our studies indicate that the prediction method, the contribution ratio of including animals, and genetic relatedness could affect the prediction accuracy in genomic evaluation of Holstein cattle, when including genotyped cows in the reference population.

Abnormal bias dependence of magnetoresistance in CoFeB/MgO/Si spin-injection tunnel contacts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, June-Young; Park, Byong-Guk, E-mail: bgpark@kaist.ac.kr; Baek, Seung-heon Chris

We report a strong bias voltage dependence of magnetoresistance (MR) in CoFeB/MgO/Si spin-injection tunnel contacts using the three-terminal Hanle geometry. When a bias voltage is relatively large, the MR is composed of two characteristic signals: a conventional Hanle signal observed at a low magnetic field, which is due to the precession of injected spins, and another signal originating from the rotation of the magnetization at a larger magnetic field. In contrast, for a small bias voltage, additional signals appear at a wide range of magnetic fields, which occasionally overwhelms the conventional Hanle signals. Because the additional signals are pronounced atmore » a low bias and are significantly reduced by annealing at moderate temperatures, they can be attributed to multi-step tunneling via defect states at the interfaces or tunnel barrier. Our results demonstrate that the spin injection signal caused by the defect states can be evaluated by its bias voltage dependence.« less

Tirandamycin biosynthesis is mediated by co-dependent oxidative enzymes

NASA Astrophysics Data System (ADS)

Carlson, Jacob C.; Li, Shengying; Gunatilleke, Shamila S.; Anzai, Yojiro; Burr, Douglas A.; Podust, Larissa M.; Sherman, David H.

2011-08-01

Elucidation of natural product biosynthetic pathways provides important insights into the assembly of potent bioactive molecules, and expands access to unique enzymes able to selectively modify complex substrates. Here, we show full reconstitution, in vitro, of an unusual multi-step oxidative cascade for post-assembly-line tailoring of tirandamycin antibiotics. This pathway involves a remarkably versatile and iterative cytochrome P450 monooxygenase (TamI) and a flavin adenine dinucleotide-dependent oxidase (TamL), which act co-dependently through the repeated exchange of substrates. TamI hydroxylates tirandamycin C (TirC) to generate tirandamycin E (TirE), a previously unidentified tirandamycin intermediate. TirE is subsequently oxidized by TamL, giving rise to the ketone of tirandamycin D (TirD), after which a unique exchange back to TamI enables successive epoxidation and hydroxylation to afford, respectively, the final products tirandamycin A (TirA) and tirandamycin B (TirB). Ligand-free, substrate- and product-bound crystal structures of bicovalently flavinylated TamL oxidase reveal a likely mechanism for the C10 oxidation of TirE.

A two-column formalism for time-dependent modelling of stellar convection. I. Description of the method

NASA Astrophysics Data System (ADS)

Stökl, A.

2008-11-01

Context: In spite of all the advances in multi-dimensional hydrodynamics, investigations of stellar evolution and stellar pulsations still depend on one-dimensional computations. This paper devises an alternative to the mixing-length theory or turbulence models usually adopted in modelling convective transport in such studies. Aims: The present work attempts to develop a time-dependent description of convection, which reflects the essential physics of convection and that is only moderately dependent on numerical parameters and far less time consuming than existing multi-dimensional hydrodynamics computations. Methods: Assuming that the most extensive convective patterns generate the majority of convective transport, the convective velocity field is described using two parallel, radial columns to represent up- and downstream flows. Horizontal exchange, in the form of fluid flow and radiation, over their connecting interface couples the two columns and allows a simple circulating motion. The main parameters of this convective description have straightforward geometrical meanings, namely the diameter of the columns (corresponding to the size of the convective cells) and the ratio of the cross-section between up- and downdrafts. For this geometrical setup, the time-dependent solution of the equations of radiation hydrodynamics is computed from an implicit scheme that has the advantage of being unaffected by the Courant-Friedrichs-Lewy time-step limit. This implementation is part of the TAPIR-Code (short for The adaptive, implicit RHD-Code). Results: To demonstrate the approach, results for convection zones in Cepheids are presented. The convective energy transport and convective velocities agree with expectations for Cepheids and the scheme reproduces both the kinetic energy flux and convective overshoot. A study of the parameter influence shows that the type of solution derived for these stars is in fact fairly robust with respect to the constitutive numerical parameters.

Hybrid Pareto artificial bee colony algorithm for multi-objective single machine group scheduling problem with sequence-dependent setup times and learning effects.

PubMed

Yue, Lei; Guan, Zailin; Saif, Ullah; Zhang, Fei; Wang, Hao

2016-01-01

Group scheduling is significant for efficient and cost effective production system. However, there exist setup times between the groups, which require to decrease it by sequencing groups in an efficient way. Current research is focused on a sequence dependent group scheduling problem with an aim to minimize the makespan in addition to minimize the total weighted tardiness simultaneously. In most of the production scheduling problems, the processing time of jobs is assumed as fixed. However, the actual processing time of jobs may be reduced due to "learning effect". The integration of sequence dependent group scheduling problem with learning effects has been rarely considered in literature. Therefore, current research considers a single machine group scheduling problem with sequence dependent setup times and learning effects simultaneously. A novel hybrid Pareto artificial bee colony algorithm (HPABC) with some steps of genetic algorithm is proposed for current problem to get Pareto solutions. Furthermore, five different sizes of test problems (small, small medium, medium, large medium, large) are tested using proposed HPABC. Taguchi method is used to tune the effective parameters of the proposed HPABC for each problem category. The performance of HPABC is compared with three famous multi objective optimization algorithms, improved strength Pareto evolutionary algorithm (SPEA2), non-dominated sorting genetic algorithm II (NSGAII) and particle swarm optimization algorithm (PSO). Results indicate that HPABC outperforms SPEA2, NSGAII and PSO and gives better Pareto optimal solutions in terms of diversity and quality for almost all the instances of the different sizes of problems.

A real-time extension of density matrix embedding theory for non-equilibrium electron dynamics

NASA Astrophysics Data System (ADS)

Kretchmer, Joshua S.; Chan, Garnet Kin-Lic

2018-02-01

We introduce real-time density matrix embedding theory (DMET), a dynamical quantum embedding theory for computing non-equilibrium electron dynamics in strongly correlated systems. As in the previously developed static DMET, real-time DMET partitions the system into an impurity corresponding to the region of interest coupled to the surrounding environment, which is efficiently represented by a quantum bath of the same size as the impurity. In this work, we focus on a simplified single-impurity time-dependent formulation as a first step toward a multi-impurity theory. The equations of motion of the coupled impurity and bath embedding problem are derived using the time-dependent variational principle. The accuracy of real-time DMET is compared to that of time-dependent complete active space self-consistent field (TD-CASSCF) theory and time-dependent Hartree-Fock (TDHF) theory for a variety of quantum quenches in the single impurity Anderson model (SIAM), in which the Hamiltonian is suddenly changed (quenched) to induce a non-equilibrium state. Real-time DMET shows a marked improvement over the mean-field TDHF, converging to the exact answer even in the non-trivial Kondo regime of the SIAM. However, as expected from analogous behavior in static DMET, the constrained structure of the real-time DMET wavefunction leads to a slower convergence with respect to active space size, in the single-impurity formulation, relative to TD-CASSCF. Our initial results suggest that real-time DMET provides a promising framework to simulate non-equilibrium electron dynamics in which strong electron correlation plays an important role, and lays the groundwork for future multi-impurity formulations.

A real-time extension of density matrix embedding theory for non-equilibrium electron dynamics.

PubMed

Kretchmer, Joshua S; Chan, Garnet Kin-Lic

2018-02-07

We introduce real-time density matrix embedding theory (DMET), a dynamical quantum embedding theory for computing non-equilibrium electron dynamics in strongly correlated systems. As in the previously developed static DMET, real-time DMET partitions the system into an impurity corresponding to the region of interest coupled to the surrounding environment, which is efficiently represented by a quantum bath of the same size as the impurity. In this work, we focus on a simplified single-impurity time-dependent formulation as a first step toward a multi-impurity theory. The equations of motion of the coupled impurity and bath embedding problem are derived using the time-dependent variational principle. The accuracy of real-time DMET is compared to that of time-dependent complete active space self-consistent field (TD-CASSCF) theory and time-dependent Hartree-Fock (TDHF) theory for a variety of quantum quenches in the single impurity Anderson model (SIAM), in which the Hamiltonian is suddenly changed (quenched) to induce a non-equilibrium state. Real-time DMET shows a marked improvement over the mean-field TDHF, converging to the exact answer even in the non-trivial Kondo regime of the SIAM. However, as expected from analogous behavior in static DMET, the constrained structure of the real-time DMET wavefunction leads to a slower convergence with respect to active space size, in the single-impurity formulation, relative to TD-CASSCF. Our initial results suggest that real-time DMET provides a promising framework to simulate non-equilibrium electron dynamics in which strong electron correlation plays an important role, and lays the groundwork for future multi-impurity formulations.

Ascending Stairway Modeling: A First Step Toward Autonomous Multi-Floor Exploration

DTIC Science & Technology

2012-10-01

Many robotics platforms are capable of ascending stairways, but all existing approaches for autonomous stair climbing use stairway detection as a...the rich potential of an autonomous ground robot that can climb stairs while exploring a multi-floor building. Our proposed solution to this problem is...over several steps. However, many ground robots are not capable of traversing tight spiral stairs , and so we do not focus on these types. The stairway is

Hot Forging of a Cladded Component by Automated GMAW Process

NASA Astrophysics Data System (ADS)

Rafiq, Muhammad; Langlois, Laurent; Bigot, Régis

2011-01-01

Weld cladding is employed to improve the service life of engineering components by increasing corrosion and wear resistance and reducing the cost. The acceptable multi-bead cladding layer depends on single bead geometry. Hence, in first step, the relationship between input process parameters and the single bead geometry is studied and in second step a comprehensive study on multi bead clad layer deposition is carried out. This paper highlights an experimental study carried out to get single layer cladding deposited by automated Gas Metal Arc Welding (GMAW) process and to find the possibility of hot forming of the cladded work piece to get the final hot formed improved structure. GMAW is an arc welding process that uses an arc between a consumable electrode and the welding pool with an external shielding gas and the cladding is done by alongside deposition of weld beads. The experiments for single bead were conducted by varying the three main process parameters wire feed rate, arc voltage and welding speed while keeping other parameters like nozzle to work distance, shielding gas and its flow rate and torch angle constant. The effect of bead spacing and torch orientation on the cladding quality of single layer from the results of single bead deposition was studied. Effect of the dilution rate and nominal energy on the cladded layer hot bending quality was also performed at different temperatures.

Multi-time Scale Coordination of Distributed Energy Resources in Isolated Power Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mayhorn, Ebony; Xie, Le; Butler-Purry, Karen

2016-03-31

In isolated power systems, including microgrids, distributed assets, such as renewable energy resources (e.g. wind, solar) and energy storage, can be actively coordinated to reduce dependency on fossil fuel generation. The key challenge of such coordination arises from significant uncertainty and variability occurring at small time scales associated with increased penetration of renewables. Specifically, the problem is with ensuring economic and efficient utilization of DERs, while also meeting operational objectives such as adequate frequency performance. One possible solution is to reduce the time step at which tertiary controls are implemented and to ensure feedback and look-ahead capability are incorporated tomore » handle variability and uncertainty. However, reducing the time step of tertiary controls necessitates investigating time-scale coupling with primary controls so as not to exacerbate system stability issues. In this paper, an optimal coordination (OC) strategy, which considers multiple time-scales, is proposed for isolated microgrid systems with a mix of DERs. This coordination strategy is based on an online moving horizon optimization approach. The effectiveness of the strategy was evaluated in terms of economics, technical performance, and computation time by varying key parameters that significantly impact performance. The illustrative example with realistic scenarios on a simulated isolated microgrid test system suggests that the proposed approach is generalizable towards designing multi-time scale optimal coordination strategies for isolated power systems.« less

Volume 2: Explicit, multistage upwind schemes for Euler and Navier-Stokes equations

NASA Technical Reports Server (NTRS)

Elmiligui, Alaa; Ash, Robert L.

1992-01-01

The objective of this study was to develop a high-resolution-explicit-multi-block numerical algorithm, suitable for efficient computation of the three-dimensional, time-dependent Euler and Navier-Stokes equations. The resulting algorithm has employed a finite volume approach, using monotonic upstream schemes for conservation laws (MUSCL)-type differencing to obtain state variables at cell interface. Variable interpolations were written in the k-scheme formulation. Inviscid fluxes were calculated via Roe's flux-difference splitting, and van Leer's flux-vector splitting techniques, which are considered state of the art. The viscous terms were discretized using a second-order, central-difference operator. Two classes of explicit time integration has been investigated for solving the compressible inviscid/viscous flow problems--two-state predictor-corrector schemes, and multistage time-stepping schemes. The coefficients of the multistage time-stepping schemes have been modified successfully to achieve better performance with upwind differencing. A technique was developed to optimize the coefficients for good high-frequency damping at relatively high CFL numbers. Local time-stepping, implicit residual smoothing, and multigrid procedure were added to the explicit time stepping scheme to accelerate convergence to steady-state. The developed algorithm was implemented successfully in a multi-block code, which provides complete topological and geometric flexibility. The only requirement is C degree continuity of the grid across the block interface. The algorithm has been validated on a diverse set of three-dimensional test cases of increasing complexity. The cases studied were: (1) supersonic corner flow; (2) supersonic plume flow; (3) laminar and turbulent flow over a flat plate; (4) transonic flow over an ONERA M6 wing; and (5) unsteady flow of a compressible jet impinging on a ground plane (with and without cross flow). The emphasis of the test cases was validation of code, and assessment of performance, as well as demonstration of flexibility.

Two- and multi-step annealing of cereal starches in relation to gelatinization.

PubMed

Shi, Yong-Cheng

2008-02-13

Two- and multi-step annealing experiments were designed to determine how much gelatinization temperature of waxy rice, waxy barley, and wheat starches could be increased without causing a decrease in gelatinization enthalpy or a decline in X-ray crystallinity. A mixture of starch and excess water was heated in a differential scanning calorimeter (DSC) pan to a specific temperature and maintained there for 0.5-48 h. The experimental approach was first to anneal a starch at a low temperature so that the gelatinization temperature of the starch was increased without causing a decrease in gelatinization enthalpy. The annealing temperature was then raised, but still was kept below the onset gelatinization temperature of the previously annealed starch. When a second- or third-step annealing temperature was high enough, it caused a decrease in crystallinity, even though the holding temperature remained below the onset gelatinization temperature of the previously annealed starch. These results support that gelatinization is a nonequilibrium process and that dissociation of double helices is driven by the swelling of amorphous regions. Small-scale starch slurry annealing was also performed and confirmed the annealing results conducted in DSC pans. A three-phase model of a starch granule, a mobile amorphous phase, a rigid amorphous phase, and a crystalline phase, was used to interpret the annealing results. Annealing seems to be an interplay between a more efficient packing of crystallites in starch granules and swelling of plasticized amorphous regions. There is always a temperature ceiling that can be used to anneal a starch without causing a decrease in crystallinity. That temperature ceiling is starch-specific, dependent on the structure of a starch, and is lower than the original onset gelatinization of a starch.

Performance of conventional multi-barrier drinking water treatment plants for the removal of four artificial sweeteners.

PubMed

Scheurer, Marco; Storck, Florian R; Brauch, Heinz-J; Lange, Frank T

2010-06-01

Due to incomplete removal of artificial sweeteners in wastewater treatment plants some of these compounds end up in receiving surface waters, which are used for drinking water production. The sum of removal efficiency of single treatment steps in multi-barrier treatment systems affects the concentrations of these compounds in the provided drinking water. This is the first systematic study revealing the effectiveness of single treatment steps in laboratory experiments and in waterworks. Six full-scale waterworks using surface water influenced raw water were sampled up to ten times to study the fate of acesulfame, saccharin, cyclamate and sucralose. For the most important treatment technologies the results were confirmed by laboratory batch experiments. Saccharin and cyclamate proved to play a minor role for drinking water treatment plants as they were eliminated by nearly 100% in all waterworks with biologically active treatment units like river bank filtration (RBF) or artificial groundwater recharge. Acesulfame and sucralose were not biodegraded during RBF and their suitability as wastewater tracers under aerobic conditions was confirmed. Sucralose proved to be persistent against ozone and its transformation was < 20% in lab and field investigations. Remaining traces were completely removed by subsequent granular activated carbon (GAC) filters. Acesulfame readily reacts with ozone (pseudo first-order rate constant k = 1.3 x 10(-3) s(-1) at 1 mg L(-1) ozone concentration). However, the applied ozone concentrations and contact times under typical waterworks conditions only led to an incomplete removal (18-60%) in the ozonation step. Acesulfame was efficiently removed by subsequent GAC filters with a low throughput of less than 30 m(3) kg(-1), but removal strongly depended on the GAC preload. Thus, acesulfame was detected up to 0.76 microg L(-1) in finished water. 2010 Elsevier Ltd. All rights reserved.

The noni anthraquinone damnacanthal is a multi-kinase inhibitor with potent anti-angiogenic effects.

PubMed

García-Vilas, Javier A; Pino-Ángeles, Almudena; Martínez-Poveda, Beatriz; Quesada, Ana R; Medina, Miguel Ángel

2017-01-28

The natural bioactive compound damnacanthal inhibits several tyrosine kinases. Herein, we show that -in fact- damancanthal is a multi kinase inhibitor. A docking and molecular dynamics simulation approach allows getting further insight on the inhibitory effect of damnacanthal on three different kinases: vascular endothelial growth factor receptor-2, c-Met and focal adhesion kinase. Several of the kinases targeted and inhibited by damnacanthal are involved in angiogenesis. Ex vivo and in vivo experiments clearly demonstrate that, indeed, damnacanthal is a very potent inhibitor of angiogenesis. A number of in vitro assays contribute to determine the specific effects of damnacanthal on each of the steps of the angiogenic process, including inhibition of tubulogenesis, endothelial cell proliferation, survival, migration and production of extracellular matrix remodeling enzyme. Taken altogether, these results suggest that damancanthal could have potential interest for the treatment of cancer and other angiogenesis-dependent diseases. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Measuring multivariate association and beyond

PubMed Central

Josse, Julie; Holmes, Susan

2017-01-01

Simple correlation coefficients between two variables have been generalized to measure association between two matrices in many ways. Coefficients such as the RV coefficient, the distance covariance (dCov) coefficient and kernel based coefficients are being used by different research communities. Scientists use these coefficients to test whether two random vectors are linked. Once it has been ascertained that there is such association through testing, then a next step, often ignored, is to explore and uncover the association’s underlying patterns. This article provides a survey of various measures of dependence between random vectors and tests of independence and emphasizes the connections and differences between the various approaches. After providing definitions of the coefficients and associated tests, we present the recent improvements that enhance their statistical properties and ease of interpretation. We summarize multi-table approaches and provide scenarii where the indices can provide useful summaries of heterogeneous multi-block data. We illustrate these different strategies on several examples of real data and suggest directions for future research. PMID:29081877

Multi-objective evolutionary algorithms for fuzzy classification in survival prediction.

PubMed

Jiménez, Fernando; Sánchez, Gracia; Juárez, José M

2014-03-01

This paper presents a novel rule-based fuzzy classification methodology for survival/mortality prediction in severe burnt patients. Due to the ethical aspects involved in this medical scenario, physicians tend not to accept a computer-based evaluation unless they understand why and how such a recommendation is given. Therefore, any fuzzy classifier model must be both accurate and interpretable. The proposed methodology is a three-step process: (1) multi-objective constrained optimization of a patient's data set, using Pareto-based elitist multi-objective evolutionary algorithms to maximize accuracy and minimize the complexity (number of rules) of classifiers, subject to interpretability constraints; this step produces a set of alternative (Pareto) classifiers; (2) linguistic labeling, which assigns a linguistic label to each fuzzy set of the classifiers; this step is essential to the interpretability of the classifiers; (3) decision making, whereby a classifier is chosen, if it is satisfactory, according to the preferences of the decision maker. If no classifier is satisfactory for the decision maker, the process starts again in step (1) with a different input parameter set. The performance of three multi-objective evolutionary algorithms, niched pre-selection multi-objective algorithm, elitist Pareto-based multi-objective evolutionary algorithm for diversity reinforcement (ENORA) and the non-dominated sorting genetic algorithm (NSGA-II), was tested using a patient's data set from an intensive care burn unit and a standard machine learning data set from an standard machine learning repository. The results are compared using the hypervolume multi-objective metric. Besides, the results have been compared with other non-evolutionary techniques and validated with a multi-objective cross-validation technique. Our proposal improves the classification rate obtained by other non-evolutionary techniques (decision trees, artificial neural networks, Naive Bayes, and case-based reasoning) obtaining with ENORA a classification rate of 0.9298, specificity of 0.9385, and sensitivity of 0.9364, with 14.2 interpretable fuzzy rules on average. Our proposal improves the accuracy and interpretability of the classifiers, compared with other non-evolutionary techniques. We also conclude that ENORA outperforms niched pre-selection and NSGA-II algorithms. Moreover, given that our multi-objective evolutionary methodology is non-combinational based on real parameter optimization, the time cost is significantly reduced compared with other evolutionary approaches existing in literature based on combinational optimization. Copyright © 2014 Elsevier B.V. All rights reserved.

DEPENDENCE OF X-RAY BURST MODELS ON NUCLEAR REACTION RATES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cyburt, R. H.; Keek, L.; Schatz, H.

2016-10-20

X-ray bursts are thermonuclear flashes on the surface of accreting neutron stars, and reliable burst models are needed to interpret observations in terms of properties of the neutron star and the binary system. We investigate the dependence of X-ray burst models on uncertainties in (p, γ ), ( α , γ ), and ( α , p) nuclear reaction rates using fully self-consistent burst models that account for the feedbacks between changes in nuclear energy generation and changes in astrophysical conditions. A two-step approach first identified sensitive nuclear reaction rates in a single-zone model with ignition conditions chosen to matchmore » calculations with a state-of-the-art 1D multi-zone model based on the Kepler stellar evolution code. All relevant reaction rates on neutron-deficient isotopes up to mass 106 were individually varied by a factor of 100 up and down. Calculations of the 84 changes in reaction rate with the highest impact were then repeated in the 1D multi-zone model. We find a number of uncertain reaction rates that affect predictions of light curves and burst ashes significantly. The results provide insights into the nuclear processes that shape observables from X-ray bursts, and guidance for future nuclear physics work to reduce nuclear uncertainties in X-ray burst models.« less

Multi-Age Classrooms. NEA Teacher-to-Teacher Books.

ERIC Educational Resources Information Center

Gutloff, Karen, Ed.

This guide is designed for elementary school teachers to assist them in developing multi-age classrooms as part of their school restructuring efforts. Each of six sections presents a story from teachers who describe the challenges and joys of multi-age teaching, from parent backlash to school district support and praise. Section 1, "Step by…

Continuous-Time Random Walk with multi-step memory: an application to market dynamics

NASA Astrophysics Data System (ADS)

Gubiec, Tomasz; Kutner, Ryszard

2017-11-01

An extended version of the Continuous-Time Random Walk (CTRW) model with memory is herein developed. This memory involves the dependence between arbitrary number of successive jumps of the process while waiting times between jumps are considered as i.i.d. random variables. This dependence was established analyzing empirical histograms for the stochastic process of a single share price on a market within the high frequency time scale. Then, it was justified theoretically by considering bid-ask bounce mechanism containing some delay characteristic for any double-auction market. Our model appeared exactly analytically solvable. Therefore, it enables a direct comparison of its predictions with their empirical counterparts, for instance, with empirical velocity autocorrelation function. Thus, the present research significantly extends capabilities of the CTRW formalism. Contribution to the Topical Issue "Continuous Time Random Walk Still Trendy: Fifty-year History, Current State and Outlook", edited by Ryszard Kutner and Jaume Masoliver.

Anti-apoptotic effect of hyperglycemia can allow survival of potentially autoreactive T cells.

PubMed

Ramakrishnan, P; Kahn, D A; Baltimore, D

2011-04-01

Thymocyte development is a tightly controlled multi-step process involving selective elimination of self-reactive and non-functional T cells by apoptosis. This developmental process depends on signaling by Notch, IL-7 and active glucose metabolism. In this study, we explored the requirement of glucose for thymocyte survival and found that in addition to metabolic regulation, glucose leads to the expression of anti-apoptotic genes. Under hyperglycemic conditions, both mouse and human thymocytes demonstrate enhanced survival. We show that glucose-induced anti-apoptotic genes are dependent on NF-κB p65 because high glucose is unable to attenuate normal ongoing apoptosis of thymocytes isolated from p65 knockout mice. Furthermore, we demonstrate that in vivo hyperglycemia decreases apoptosis of thymocytes allowing for survival of potentially self-reactive thymocytes. These results imply that hyperglycemic conditions could contribute to the development of autoimmunity through dysregulated thymic selection. © 2011 Macmillan Publishers Limited

Multigrid methods for isogeometric discretization

PubMed Central

Gahalaut, K.P.S.; Kraus, J.K.; Tomar, S.K.

2013-01-01

We present (geometric) multigrid methods for isogeometric discretization of scalar second order elliptic problems. The smoothing property of the relaxation method, and the approximation property of the intergrid transfer operators are analyzed. These properties, when used in the framework of classical multigrid theory, imply uniform convergence of two-grid and multigrid methods. Supporting numerical results are provided for the smoothing property, the approximation property, convergence factor and iterations count for V-, W- and F-cycles, and the linear dependence of V-cycle convergence on the smoothing steps. For two dimensions, numerical results include the problems with variable coefficients, simple multi-patch geometry, a quarter annulus, and the dependence of convergence behavior on refinement levels ℓ, whereas for three dimensions, only the constant coefficient problem in a unit cube is considered. The numerical results are complete up to polynomial order p=4, and for C0 and Cp-1 smoothness. PMID:24511168

Three is a crowd in iterated prisoner's dilemmas: experimental evidence on reciprocal behavior

NASA Astrophysics Data System (ADS)

Grujić, Jelena; Eke, Burcu; Cabrales, Antonio; Cuesta, José A.; Sánchez, Angel

2012-09-01

Reciprocity or conditional cooperation is one of the most prominent mechanisms proposed to explain the emergence of cooperation in social dilemmas. Recent experimental findings on networked games suggest that conditional cooperation may also depend on the previous action of the player. We here report on experiments on iterated, multi-player Prisoner's dilemma, on groups of 2 to 5 people. We confirm the dependence on the previous step and that memory effects for earlier periods are not significant. We show that the behavior of subjects in pairwise dilemmas is qualitatively different from the cases with more players; After an initial decay, cooperation increases significantly reaching values above 80%. The strategy of the players is rather universal as far as their willingness to reciprocate cooperation is concerned, whereas there is much diversity in their initial propensity to cooperate. Our results indicate that, for cooperation to emerge and thrive, three is a crowd.

Mobile Genome Express (MGE): A comprehensive automatic genetic analyses pipeline with a mobile device.

PubMed

Yoon, Jun-Hee; Kim, Thomas W; Mendez, Pedro; Jablons, David M; Kim, Il-Jin

2017-01-01

The development of next-generation sequencing (NGS) technology allows to sequence whole exomes or genome. However, data analysis is still the biggest bottleneck for its wide implementation. Most laboratories still depend on manual procedures for data handling and analyses, which translates into a delay and decreased efficiency in the delivery of NGS results to doctors and patients. Thus, there is high demand for developing an automatic and an easy-to-use NGS data analyses system. We developed comprehensive, automatic genetic analyses controller named Mobile Genome Express (MGE) that works in smartphones or other mobile devices. MGE can handle all the steps for genetic analyses, such as: sample information submission, sequencing run quality check from the sequencer, secured data transfer and results review. We sequenced an Actrometrix control DNA containing multiple proven human mutations using a targeted sequencing panel, and the whole analysis was managed by MGE, and its data reviewing program called ELECTRO. All steps were processed automatically except for the final sequencing review procedure with ELECTRO to confirm mutations. The data analysis process was completed within several hours. We confirmed the mutations that we have identified were consistent with our previous results obtained by using multi-step, manual pipelines.

Effects of the Acrylic Polyol Structure and the Selectivity of the Employed Catalyst on the Performance of Two-Component Aqueous Polyurethane Coatings

PubMed Central

Cakic, Suzana; Lacnjevac, Caslav; Stamenkovic, Jakov; Ristic, Nikola; Takic, Ljiljana; Barac, Miroljub; Gligoric, Miladin

2007-01-01

Two kinds of aqueous acrylic polyols (single step and multi step synthesis type) have been investigated for their performance in the two-component aqueous polyurethane application, by using more selective catalysts. The aliphatic polyfunctional isocyanates based on hexamethylen diisocyanates have been employed as suitable hardeners. The complex of zirconium, commercially known as K-KAT®XC-6212, and manganese (III) complexes with mixed ligands based on the derivative of maleic acid have been used as catalysts in this study. Both of the aqueous polyols give good results, in terms of application and hardness, when elevated temperatures and more selective catalysts are applied. A more selective catalyst promotes the reaction between the isocyanate and polyol component. This increases the percentage of urethane bonds and the degree of hardness in the films formed from the two components of aqueous polyurethane lacquers. The polyol based on the single step synthesis route is favourable concerning potlife and hardness. The obtained results show that the performance of the two-component aqueous polyurethane coatings depends on the polymer structure of the polyols as well as on the selectivity of the employed catalyst.

Analysis of a multi-wavelength multi-camera phase-shifting profilometric system for real-time operation

NASA Astrophysics Data System (ADS)

Stoykova, Elena; Gotchev, Atanas; Sainov, Ventseslav

2011-01-01

Real-time accomplishment of a phase-shifting profilometry through simultaneous projection and recording of fringe patterns requires a reliable phase retrieval procedure. In the present work we consider a four-wavelength multi-camera system with four sinusoidal phase gratings for pattern projection that implements a four-step algorithm. Successful operation of the system depends on overcoming two challenges which stem out from the inherent limitations of the phase-shifting algorithm, namely the demand for a sinusoidal fringe profile and the necessity to ensure equal background and contrast of fringes in the recorded fringe patterns. As a first task, we analyze the systematic errors due to the combined influence of the higher harmonics and multi-wavelength illumination in the Fresnel diffraction zone considering the case when the modulation parameters of the four gratings are different. As a second task we simulate the system performance to evaluate the degrading effect of the speckle noise and the spatially varying fringe modulation at non-uniform illumination on the overall accuracy of the profilometric measurement. We consider the case of non-correlated speckle realizations in the recorded fringe patterns due to four-wavelength illumination. Finally, we apply a phase retrieval procedure which includes normalization, background removal and denoising of the recorded fringe patterns to both simulated and measured data obtained for a dome surface.

A mass, momentum, and energy conserving, fully implicit, scalable algorithm for the multi-dimensional, multi-species Rosenbluth-Fokker-Planck equation

NASA Astrophysics Data System (ADS)

Taitano, W. T.; Chacón, L.; Simakov, A. N.; Molvig, K.

2015-09-01

In this study, we demonstrate a fully implicit algorithm for the multi-species, multidimensional Rosenbluth-Fokker-Planck equation which is exactly mass-, momentum-, and energy-conserving, and which preserves positivity. Unlike most earlier studies, we base our development on the Rosenbluth (rather than Landau) form of the Fokker-Planck collision operator, which reduces complexity while allowing for an optimal fully implicit treatment. Our discrete conservation strategy employs nonlinear constraints that force the continuum symmetries of the collision operator to be satisfied upon discretization. We converge the resulting nonlinear system iteratively using Jacobian-free Newton-Krylov methods, effectively preconditioned with multigrid methods for efficiency. Single- and multi-species numerical examples demonstrate the advertised accuracy properties of the scheme, and the superior algorithmic performance of our approach. In particular, the discretization approach is numerically shown to be second-order accurate in time and velocity space and to exhibit manifestly positive entropy production. That is, H-theorem behavior is indicated for all the examples we have tested. The solution approach is demonstrated to scale optimally with respect to grid refinement (with CPU time growing linearly with the number of mesh points), and timestep (showing very weak dependence of CPU time with time-step size). As a result, the proposed algorithm delivers several orders-of-magnitude speedup vs. explicit algorithms.

On the Development of Multi-Step Inverse FEM with Shell Model

NASA Astrophysics Data System (ADS)

Huang, Y.; Du, R.

2005-08-01

The inverse or one-step finite element approach is increasingly used in the sheet metal stamping industry to predict strain distribution and the initial blank shape in the preliminary design stage. Based on the existing theory, there are two types of method: one is based on the principle of virtual work and the other is based on the principle of extreme work. Much research has been conducted to improve the accuracy of simulation results. For example, based on the virtual work principle, Batoz et al. developed a new method using triangular DKT shell elements. In this new method, the bending and unbending effects are considered. Based on the principle of extreme work, Majlessi and et al. proposed the multi-step inverse approach with membrane elements and applied it to an axis-symmetric part. Lee and et al. presented an axis-symmetric shell element model to solve the similar problem. In this paper, a new multi-step inverse method is introduced with no limitation on the workpiece shape. It is a shell element model based on the virtual work principle. The new method is validated by means of comparing to the commercial software system (PAMSTAMP®). The comparison results indicate that the accuracy is good.

Adaptive Numerical Algorithms in Space Weather Modeling

NASA Technical Reports Server (NTRS)

Toth, Gabor; vanderHolst, Bart; Sokolov, Igor V.; DeZeeuw, Darren; Gombosi, Tamas I.; Fang, Fang; Manchester, Ward B.; Meng, Xing; Nakib, Dalal; Powell, Kenneth G.;

WAKES: Wavelet Adaptive Kinetic Evolution Solvers

NASA Astrophysics Data System (ADS)

Mardirian, Marine; Afeyan, Bedros; Larson, David

2016-10-01

We are developing a general capability to adaptively solve phase space evolution equations mixing particle and continuum techniques in an adaptive manner. The multi-scale approach is achieved using wavelet decompositions which allow phase space density estimation to occur with scale dependent increased accuracy and variable time stepping. Possible improvements on the SFK method of Larson are discussed, including the use of multiresolution analysis based Richardson-Lucy Iteration, adaptive step size control in explicit vs implicit approaches. Examples will be shown with KEEN waves and KEEPN (Kinetic Electrostatic Electron Positron Nonlinear) waves, which are the pair plasma generalization of the former, and have a much richer span of dynamical behavior. WAKES techniques are well suited for the study of driven and released nonlinear, non-stationary, self-organized structures in phase space which have no fluid, limit nor a linear limit, and yet remain undamped and coherent well past the drive period. The work reported here is based on the Vlasov-Poisson model of plasma dynamics. Work supported by a Grant from the AFOSR.

Process Simulation of Aluminium Sheet Metal Deep Drawing at Elevated Temperatures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Winklhofer, Johannes; Trattnig, Gernot; Lind, Christoph

Lightweight design is essential for an economic and environmentally friendly vehicle. Aluminium sheet metal is well known for its ability to improve the strength to weight ratio of lightweight structures. One disadvantage of aluminium is that it is less formable than steel. Therefore complex part geometries can only be realized by expensive multi-step production processes. One method for overcoming this disadvantage is deep drawing at elevated temperatures. In this way the formability of aluminium sheet metal can be improved significantly, and the number of necessary production steps can thereby be reduced. This paper introduces deep drawing of aluminium sheet metalmore » at elevated temperatures, a corresponding simulation method, a characteristic process and its optimization. The temperature and strain rate dependent material properties of a 5xxx series alloy and their modelling are discussed. A three dimensional thermomechanically coupled finite element deep drawing simulation model and its validation are presented. Based on the validated simulation model an optimised process strategy regarding formability, time and cost is introduced.« less

RISC assembly: Coordination between small RNAs and Argonaute proteins.

PubMed

Kobayashi, Hotaka; Tomari, Yukihide

2016-01-01

Non-coding RNAs generally form ribonucleoprotein (RNP) complexes with their partner proteins to exert their functions. Small RNAs, including microRNAs, small interfering RNAs, and PIWI-interacting RNAs, assemble with Argonaute (Ago) family proteins into the effector complex called RNA-induced silencing complex (RISC), which mediates sequence-specific target gene silencing. RISC assembly is not a simple binding between a small RNA and Ago; rather, it follows an ordered multi-step pathway that requires specific accessory factors. Some steps of RISC assembly and RISC-mediated gene silencing are dependent on or facilitated by particular intracellular platforms, suggesting their spatial regulation. In this review, we summarize the currently known mechanisms for RISC assembly of each small RNA class and propose a revised model for the role of the chaperone machinery in the duplex-initiated RISC assembly pathway. This article is part of a Special Issue entitled: Clues to long noncoding RNA taxonomy1, edited by Dr. Tetsuro Hirose and Dr. Shinichi Nakagawa. Copyright © 2015 Elsevier B.V. All rights reserved.

Practical multipeptide synthesis: dedicated software for the definition of multiple, overlapping peptides covering polypeptide sequences.

PubMed

Heegaard, P M; Holm, A; Hagerup, M

1993-01-01

A personal computer program for the conversion of linear amino acid sequences to multiple, small, overlapping peptide sequences has been developed. Peptide lengths and "jumps" (the distance between two consecutive overlapping peptides) are defined by the user. To facilitate the use of the program for parallel solid-phase chemical peptide syntheses for the synchronous production of multiple peptides, amino acids at each acylation step are laid out by the program in a convenient standard multi-well setup. Also, the total number of equivalents, as well as the derived amount in milligrams (depend-ending on user-defined equivalent weights and molar surplus), of each amino acid are given. The program facilitates the implementation of multipeptide synthesis, e.g., for the elucidation of polypeptide structure-function relationships, and greatly reduces the risk of introducing mistakes at the planning step. It is written in Pascal and runs on any DOS-based personal computer. No special graphic display is needed.

Microarc oxidation coating covered Ti implants with micro-scale gouges formed by a multi-step treatment for improving osseointegration.

PubMed

Bai, Yixin; Zhou, Rui; Cao, Jianyun; Wei, Daqing; Du, Qing; Li, Baoqiang; Wang, Yaming; Jia, Dechang; Zhou, Yu

2017-07-01

The sub-microporous microarc oxidation (MAO) coating covered Ti implant with micro-scale gouges has been fabricated via a multi-step MAO process to overcome the compromised bone-implant integration. The as-prepared implant has been further mediated by post-heat treatment to compare the effects of -OH functional group and the nano-scale orange peel-like morphology on osseointegration. The bone regeneration, bone-implant contact interface, and biomechanical push-out force of the modified Ti implant have been discussed thoroughly in this work. The greatly improved push-out force for the MAO coated Ti implants with micro-scale gouges could be attributed to the excellent mechanical interlocking effect between implants and biologically meshed bone tissues. Attributed to the -OH functional group which promotes synostosis between the biologically meshed bone and the gouge surface of implant, the multi-step MAO process could be an effective strategy to improve the osseointegration of Ti implant. Copyright © 2017 Elsevier B.V. All rights reserved.

Long-term memory-based control of attention in multi-step tasks requires working memory: evidence from domain-specific interference

PubMed Central

Foerster, Rebecca M.; Carbone, Elena; Schneider, Werner X.

2014-01-01

Evidence for long-term memory (LTM)-based control of attention has been found during the execution of highly practiced multi-step tasks. However, does LTM directly control for attention or are working memory (WM) processes involved? In the present study, this question was investigated with a dual-task paradigm. Participants executed either a highly practiced visuospatial sensorimotor task (speed stacking) or a verbal task (high-speed poem reciting), while maintaining visuospatial or verbal information in WM. Results revealed unidirectional and domain-specific interference. Neither speed stacking nor high-speed poem reciting was influenced by WM retention. Stacking disrupted the retention of visuospatial locations, but did not modify memory performance of verbal material (letters). Reciting reduced the retention of verbal material substantially whereas it affected the memory performance of visuospatial locations to a smaller degree. We suggest that the selection of task-relevant information from LTM for the execution of overlearned multi-step tasks recruits domain-specific WM. PMID:24847304

A novel class sensitive hashing technique for large-scale content-based remote sensing image retrieval

NASA Astrophysics Data System (ADS)

Reato, Thomas; Demir, Begüm; Bruzzone, Lorenzo

2017-10-01

This paper presents a novel class sensitive hashing technique in the framework of large-scale content-based remote sensing (RS) image retrieval. The proposed technique aims at representing each image with multi-hash codes, each of which corresponds to a primitive (i.e., land cover class) present in the image. To this end, the proposed method consists of a three-steps algorithm. The first step is devoted to characterize each image by primitive class descriptors. These descriptors are obtained through a supervised approach, which initially extracts the image regions and their descriptors that are then associated with primitives present in the images. This step requires a set of annotated training regions to define primitive classes. A correspondence between the regions of an image and the primitive classes is built based on the probability of each primitive class to be present at each region. All the regions belonging to the specific primitive class with a probability higher than a given threshold are highly representative of that class. Thus, the average value of the descriptors of these regions is used to characterize that primitive. In the second step, the descriptors of primitive classes are transformed into multi-hash codes to represent each image. This is achieved by adapting the kernel-based supervised locality sensitive hashing method to multi-code hashing problems. The first two steps of the proposed technique, unlike the standard hashing methods, allow one to represent each image by a set of primitive class sensitive descriptors and their hash codes. Then, in the last step, the images in the archive that are very similar to a query image are retrieved based on a multi-hash-code-matching scheme. Experimental results obtained on an archive of aerial images confirm the effectiveness of the proposed technique in terms of retrieval accuracy when compared to the standard hashing methods.

Multi-Time Step Service Restoration for Advanced Distribution Systems and Microgrids

DOE PAGES

Chen, Bo; Chen, Chen; Wang, Jianhui; ...

2017-07-07

Modern power systems are facing increased risk of disasters that can cause extended outages. The presence of remote control switches (RCSs), distributed generators (DGs), and energy storage systems (ESS) provides both challenges and opportunities for developing post-fault service restoration methodologies. Inter-temporal constraints of DGs, ESS, and loads under cold load pickup (CLPU) conditions impose extra complexity on problem formulation and solution. In this paper, a multi-time step service restoration methodology is proposed to optimally generate a sequence of control actions for controllable switches, ESSs, and dispatchable DGs to assist the system operator with decision making. The restoration sequence is determinedmore » to minimize the unserved customers by energizing the system step by step without violating operational constraints at each time step. The proposed methodology is formulated as a mixed-integer linear programming (MILP) model and can adapt to various operation conditions. Furthermore, the proposed method is validated through several case studies that are performed on modified IEEE 13-node and IEEE 123-node test feeders.« less

Multi-Time Step Service Restoration for Advanced Distribution Systems and Microgrids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Bo; Chen, Chen; Wang, Jianhui

Modern power systems are facing increased risk of disasters that can cause extended outages. The presence of remote control switches (RCSs), distributed generators (DGs), and energy storage systems (ESS) provides both challenges and opportunities for developing post-fault service restoration methodologies. Inter-temporal constraints of DGs, ESS, and loads under cold load pickup (CLPU) conditions impose extra complexity on problem formulation and solution. In this paper, a multi-time step service restoration methodology is proposed to optimally generate a sequence of control actions for controllable switches, ESSs, and dispatchable DGs to assist the system operator with decision making. The restoration sequence is determinedmore » to minimize the unserved customers by energizing the system step by step without violating operational constraints at each time step. The proposed methodology is formulated as a mixed-integer linear programming (MILP) model and can adapt to various operation conditions. Furthermore, the proposed method is validated through several case studies that are performed on modified IEEE 13-node and IEEE 123-node test feeders.« less

Self-etch and etch-and-rinse adhesive systems in clinical dentistry.

PubMed

Ozer, Fusun; Blatz, Markus B

2013-01-01

Current adhesive systems follow either an "etch-and-rinse" or "self-etch" approach, which differ in how they interact with natural tooth structures. Etch-and-rinse systems comprise phosphoric acid to pretreat the dental hard tissues before rinsing and subsequent application of an adhesive. Self-etch adhesives contain acidic monomers, which etch and prime the tooth simultaneously. Etch-and-rinse adhesives are offered as two- or three-step systems, depending on whether primer and bonding are separate or combined in a single bottle. Similarly, self-etch adhesives are available as one- or two-step systems. Both etch-and-rinse and self-etch systems form a hybrid layer as a result of resins impregnating the porous enamel or dentin. Despite current trends toward fewer and simpler clinical application steps, one-step dentin bonding systems exhibit bonding agent lower bond strengths and seem less predictable than multi-step etch-and-rinse and self-etch systems. The varying evidence available today suggests that the choice between etch-and-rinse and self-etch systems is often a matter of personal preference. In general, however, phosphoric acid creates a more pronounced and retentive etching pattern in enamel. Therefore, etch-and-rinse bonding systems are often preferred for indirect restorations and when large areas of enamel are still present. Conversely, self-etch adhesives provide superior and more predictable bond strength to dentin and are, consequently, recommended for direct composite resin restorations, especially when predominantly supported by dentin.

Quantification of soil water retention parameters using multi-section TDR-waveform analysis

NASA Astrophysics Data System (ADS)

Baviskar, S. M.; Heimovaara, T. J.

2017-06-01

Soil water retention parameters are important for describing flow in variably saturated soils. TDR is one of the standard methods used for determining water content in soil samples. In this study, we present an approach to estimate water retention parameters of a sample which is initially saturated and subjected to an incremental decrease in boundary head causing it to drain in a multi-step fashion. TDR waveforms are measured along the height of the sample at assumed different hydrostatic conditions at daily interval. The cumulative discharge outflow drained from the sample is also recorded. The saturated water content is obtained using volumetric analysis after the final step involved in multi-step drainage. The equation obtained by coupling the unsaturated parametric function and the apparent dielectric permittivity is fitted to a TDR wave propagation forward model. The unsaturated parametric function is used to spatially interpolate the water contents along TDR probe. The cumulative discharge outflow data is fitted with cumulative discharge estimated using the unsaturated parametric function. The weight of water inside the sample estimated at the first and final boundary head in multi-step drainage is fitted with the corresponding weights calculated using unsaturated parametric function. A Bayesian optimization scheme is used to obtain optimized water retention parameters for these different objective functions. This approach can be used for samples with long heights and is especially suitable for characterizing sands with a uniform particle size distribution at low capillary heads.

Improved multi-level capability in Si3N4-based resistive switching memory using continuous gradual reset switching

NASA Astrophysics Data System (ADS)

Kim, Sungjun; Park, Byung-Gook

2017-01-01

In this letter, we compare three different types of reset switching behavior in a bipolar resistive random-access memory (RRAM) system that is housed in a Ni/Si3N4/Si structure. The abrupt, step-like gradual and continuous gradual reset transitions are largely determined by the low-resistance state (LRS). For abrupt reset switching, the large conducting path shows ohmic behavior or has a weak nonlinear current-voltage (I-V) characteristics in the LRS. For gradual switching, including both the step-like and continuous reset types, trap-assisted direct tunneling is dominant in the low-voltage regime, while trap-assisted Fowler-Nordheim tunneling is dominant in the high-voltage regime, thus causing nonlinear I-V characteristics. More importantly, we evaluate the multi-level capabilities of the two different gradual switching types, including both step-like and continuous reset behavior, using identical and incremental voltage conditions. Finer control of the conductance level with good uniformity is achieved in continuous gradual reset switching when compared to that in step-like gradual reset switching. For continuous reset switching, a single conducting path, which initially has a tunneling gap, gradually responds to pulses with even and identical amplitudes, while for step-like reset switching, the multiple conducting paths only respond to incremental pulses to obtain effective multi-level states.

Toward a Model Framework of Generalized Parallel Componential Processing of Multi-Symbol Numbers

ERIC Educational Resources Information Center

Huber, Stefan; Cornelsen, Sonja; Moeller, Korbinian; Nuerk, Hans-Christoph

2015-01-01

In this article, we propose and evaluate a new model framework of parallel componential multi-symbol number processing, generalizing the idea of parallel componential processing of multi-digit numbers to the case of negative numbers by considering the polarity signs similar to single digits. In a first step, we evaluated this account by defining…

Variation of nanopore diameter along porous anodic alumina channels by multi-step anodization.

PubMed

Lee, Kwang Hong; Lim, Xin Yuan; Wai, Kah Wing; Romanato, Filippo; Wong, Chee Cheong

2011-02-01

In order to form tapered nanocapillaries, we investigated a method to vary the nanopore diameter along the porous anodic alumina (PAA) channels using multi-step anodization. By anodizing the aluminum in either single acid (H3PO4) or multi-acid (H2SO4, oxalic acid and H3PO4) with increasing or decreasing voltage, the diameter of the nanopore along the PAA channel can be varied systematically corresponding to the applied voltages. The pore size along the channel can be enlarged or shrunken in the range of 20 nm to 200 nm. Structural engineering of the template along the film growth direction can be achieved by deliberately designing a suitable voltage and electrolyte together with anodization time.

Dynamic Neuromuscular Control of the Lower Limbs in Response to Unexpected Single-Planar versus Multi-Planar Support Perturbations in Young, Active Adults.

PubMed

Malfait, Bart; Staes, Filip; de Vries, Aijse; Smeets, Annemie; Hawken, Malcolm; Robinson, Mark A; Vanrenterghem, Jos; Verschueren, Sabine

2015-01-01

An anterior cruciate ligament (ACL) injury involves a multi-planar injury mechanism. Nevertheless, unexpected multi-planar perturbations have not been used to screen athletes in the context of ACL injury prevention yet could reveal those more at risk. The objective of this study was to compare neuromuscular responses to multi-planar (MPP) and single-planar perturbations (SPP) during a stepping-down task. These results might serve as a basis for future implementation of external perturbations in ACL injury screening programs. Thirteen young adults performed a single leg stepping-down task in eight conditions (four MPP and four SPP with a specified amplitude and velocity). The amplitudes of vastus lateralis (VL), vastus medialis (VM), hamstrings lateralis (HL), hamstrings medialis (HM) EMG activity, medio-lateral and anterior-posterior centre of mass (COM) displacements, the peak knee flexion and abduction angles were compared between conditions using an one-way ANOVA. Number of stepping responses were monitored during all conditions. Significantly greater muscle activity levels were found in response to the more challenging MPP and SPP compared to the less challenging conditions (p < 0.05). No differences in neuromuscular activity were found between the MPP conditions and their equivalents in the SPP. Eighteen stepping responses were monitored in the SPP versus nine in the MPP indicating that the overall neuromuscular control was even more challenged during the SPP which was supported by greater COM displacements in the SPP. The more intense MPP and SPP evoked different neuromuscular responses resulting in greater muscle activity levels compared to small perturbations. Based on the results of COM displacements and based on the amount of stepping responses, dynamic neuromuscular control of the knee joint appeared less challenged during the MPP. Therefore, future work should investigate extensively if other neuromuscular differences (i.e. co-activation patterns and kinetics) exist between MPP and SPP. In addition, future work should examine the influence on the neuromuscular control of the magnitude of the perturbations and the magnitude of stepping height and stepping distance.

Single-step reinitialization and extending algorithms for level-set based multi-phase flow simulations

NASA Astrophysics Data System (ADS)

Fu, Lin; Hu, Xiangyu Y.; Adams, Nikolaus A.

2017-12-01

We propose efficient single-step formulations for reinitialization and extending algorithms, which are critical components of level-set based interface-tracking methods. The level-set field is reinitialized with a single-step (non iterative) "forward tracing" algorithm. A minimum set of cells is defined that describes the interface, and reinitialization employs only data from these cells. Fluid states are extrapolated or extended across the interface by a single-step "backward tracing" algorithm. Both algorithms, which are motivated by analogy to ray-tracing, avoid multiple block-boundary data exchanges that are inevitable for iterative reinitialization and extending approaches within a parallel-computing environment. The single-step algorithms are combined with a multi-resolution conservative sharp-interface method and validated by a wide range of benchmark test cases. We demonstrate that the proposed reinitialization method achieves second-order accuracy in conserving the volume of each phase. The interface location is invariant to reapplication of the single-step reinitialization. Generally, we observe smaller absolute errors than for standard iterative reinitialization on the same grid. The computational efficiency is higher than for the standard and typical high-order iterative reinitialization methods. We observe a 2- to 6-times efficiency improvement over the standard method for serial execution. The proposed single-step extending algorithm, which is commonly employed for assigning data to ghost cells with ghost-fluid or conservative interface interaction methods, shows about 10-times efficiency improvement over the standard method while maintaining same accuracy. Despite their simplicity, the proposed algorithms offer an efficient and robust alternative to iterative reinitialization and extending methods for level-set based multi-phase simulations.

78 FR 13868 - New England Fishery Management Council; Public Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-01

.... It is an important early step in what will be a multi-step process to develop the policy. The agenda... opportunity for communications between participants about management and science issues that relate to the ABC...

How to use multi-criteria decision analysis methods for reimbursement decision-making in healthcare: a step-by-step guide.

PubMed

Diaby, Vakaramoko; Goeree, Ron

2014-02-01

In recent years, the quest for more comprehensiveness, structure and transparency in reimbursement decision-making in healthcare has prompted the research into alternative decision-making frameworks. In this environment, multi-criteria decision analysis (MCDA) is arising as a valuable tool to support healthcare decision-making. In this paper, we present the main MCDA decision support methods (elementary methods, value-based measurement models, goal programming models and outranking models) using a case study approach. For each family of methods, an example of how an MCDA model would operate in a real decision-making context is presented from a critical perspective, highlighting the parameters setting, the selection of the appropriate evaluation model as well as the role of sensitivity and robustness analyses. This study aims to provide a step-by-step guide on how to use MCDA methods for reimbursement decision-making in healthcare.

Long range personalized cancer treatment strategies incorporating evolutionary dynamics.

PubMed

Yeang, Chen-Hsiang; Beckman, Robert A

2016-10-22

Current cancer precision medicine strategies match therapies to static consensus molecular properties of an individual's cancer, thus determining the next therapeutic maneuver. These strategies typically maintain a constant treatment while the cancer is not worsening. However, cancers feature complicated sub-clonal structure and dynamic evolution. We have recently shown, in a comprehensive simulation of two non-cross resistant therapies across a broad parameter space representing realistic tumors, that substantial improvement in cure rates and median survival can be obtained utilizing dynamic precision medicine strategies. These dynamic strategies explicitly consider intratumoral heterogeneity and evolutionary dynamics, including predicted future drug resistance states, and reevaluate optimal therapy every 45 days. However, the optimization is performed in single 45 day steps ("single-step optimization"). Herein we evaluate analogous strategies that think multiple therapeutic maneuvers ahead, considering potential outcomes at 5 steps ahead ("multi-step optimization") or 40 steps ahead ("adaptive long term optimization (ALTO)") when recommending the optimal therapy in each 45 day block, in simulations involving both 2 and 3 non-cross resistant therapies. We also evaluate an ALTO approach for situations where simultaneous combination therapy is not feasible ("Adaptive long term optimization: serial monotherapy only (ALTO-SMO)"). Simulations utilize populations of 764,000 and 1,700,000 virtual patients for 2 and 3 drug cases, respectively. Each virtual patient represents a unique clinical presentation including sizes of major and minor tumor subclones, growth rates, evolution rates, and drug sensitivities. While multi-step optimization and ALTO provide no significant average survival benefit, cure rates are significantly increased by ALTO. Furthermore, in the subset of individual virtual patients demonstrating clinically significant difference in outcome between approaches, by far the majority show an advantage of multi-step or ALTO over single-step optimization. ALTO-SMO delivers cure rates superior or equal to those of single- or multi-step optimization, in 2 and 3 drug cases respectively. In selected virtual patients incurable by dynamic precision medicine using single-step optimization, analogous strategies that "think ahead" can deliver long-term survival and cure without any disadvantage for non-responders. When therapies require dose reduction in combination (due to toxicity), optimal strategies feature complex patterns involving rapidly interleaved pulses of combinations and high dose monotherapy. This article was reviewed by Wendy Cornell, Marek Kimmel, and Andrzej Swierniak. Wendy Cornell and Andrzej Swierniak are external reviewers (not members of the Biology Direct editorial board). Andrzej Swierniak was nominated by Marek Kimmel.

Numerical study of the direct pressure effect of acoustic waves in planar premixed flames

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schmidt, H.; Jimenez, C.

Recently the unsteady response of 1-D premixed flames to acoustic pressure waves for the range of frequencies below and above the inverse of the flame transit time was investigated experimentally using OH chemiluminescence Wangher (2008). They compared the frequency dependence of the measured response to the prediction of an analytical model proposed by Clavin et al. (1990), derived from the standard flame model (one-step Arrhenius kinetics) and to a similar model proposed by McIntosh (1991). Discrepancies between the experimental results and the model led to the conclusion that the standard model does not provide an adequate description of the unsteadymore » response of real flames and that it is necessary to investigate more realistic chemical models. Here we follow exactly this suggestion and perform numerical studies of the response of lean methane flames using different reaction mechanisms. We find that the global flame response obtained with both detailed chemistry (GRI3.0) and a reduced multi-step model by Peters (1996) lies slightly above the predictions of the analytical model, but is close to experimental results. We additionally used an irreversible one-step Arrhenius reaction model and show the effect of the pressure dependence of the global reaction rate in the flame response. Our results suggest first that the current models have to be extended to capture the amplitude and phase results of the detailed mechanisms, and second that the correlation between the heat release and the measured OH* chemiluminescence should be studied deeper. (author)« less

Multi-step contrast sensitivity gauge

DOEpatents

Quintana, Enrico C; Thompson, Kyle R; Moore, David G; Heister, Jack D; Poland, Richard W; Ellegood, John P; Hodges, George K; Prindville, James E

2014-10-14

An X-ray contrast sensitivity gauge is described herein. The contrast sensitivity gauge comprises a plurality of steps of varying thicknesses. Each step in the gauge includes a plurality of recesses of differing depths, wherein the depths are a function of the thickness of their respective step. An X-ray image of the gauge is analyzed to determine a contrast-to-noise ratio of a detector employed to generate the image.

New methodology for mechanical characterization of human superficial facial tissue anisotropic behaviour in vivo.

PubMed

Then, C; Stassen, B; Depta, K; Silber, G

2017-07-01

Mechanical characterization of human superficial facial tissue has important applications in biomedical science, computer assisted forensics, graphics, and consumer goods development. Specifically, the latter may include facial hair removal devices. Predictive accuracy of numerical models and their ability to elucidate biomechanically relevant questions depends on the acquisition of experimental data and mechanical tissue behavior representation. Anisotropic viscoelastic behavioral characterization of human facial tissue, deformed in vivo with finite strain, however, is sparse. Employing an experimental-numerical approach, a procedure is presented to evaluate multidirectional tensile properties of superficial tissue layers of the face in vivo. Specifically, in addition to stress relaxation, displacement-controlled multi-step ramp-and-hold protocols were performed to separate elastic from inelastic properties. For numerical representation, an anisotropic hyperelastic material model in conjunction with a time domain linear viscoelasticity formulation with Prony series was employed. Model parameters were inversely derived, employing finite element models, using multi-criteria optimization. The methodology provides insight into mechanical superficial facial tissue properties. Experimental data shows pronounced anisotropy, especially with large strain. The stress relaxation rate does not depend on the loading direction, but is strain-dependent. Preconditioning eliminates equilibrium hysteresis effects and leads to stress-strain repeatability. In the preconditioned state tissue stiffness and hysteresis insensitivity to strain rate in the applied range is evident. The employed material model fits the nonlinear anisotropic elastic results and the viscoelasticity model reasonably reproduces time-dependent results. Inversely deduced maximum anisotropic long-term shear modulus of linear elasticity is G ∞,max aniso =2.43kPa and instantaneous initial shear modulus at an applied rate of ramp loading is G 0,max aniso =15.38kPa. Derived mechanical model parameters constitute a basis for complex skin interaction simulation. Copyright © 2017. Published by Elsevier Ltd.

Bradyrhizobium centrolobii and Bradyrhizobium macuxiense sp. nov. isolated from Centrolobium paraense grown in soil of Amazonia, Brazil.

PubMed

Michel, Daniele C; Passos, Samuel R; Simões-Araujo, Jean L; Baraúna, Alexandre C; da Silva, Krisle; Parma, Marcia M; Melo, Itamar S; De Meyer, Sofie E; O'Hara, Graham; Zilli, Jerri E

2017-07-01

Thirteen Gram-negative, aerobic, motile with polar flagella, rod-shaped bacteria were isolated from root nodules of Centrolobium paraense Tul. grown in soils from the Amazon region of Brazil. Growth of strains was observed at temperature range 20-36 °C (optimal 28 °C), pH ranges 5-11 (optimal 6.0-7.0), and 0.1-0.5%NaCl (optimal 0.1-0.3%). Analysis of 16S rRNA gene placed the strains into two groups within Bradyrhizobium. Closest neighbouring species (98.8%) for group I was B. neotropicale while for group II were 12 species with more than 99% of similarity. Multi-locus sequence analysis (MLSA) with dnaK, glnII, recA, and rpoB confirmed B. neotropicale BR 10247 T as the closest type strain for the group I and B. elkanii USDA 76 T and B. pachyrhizi PAC 48 T for group II. Average Nucleotide Identity (ANI) differentiated group I from the B. neotropicale BR 10247 T (79.6%) and group II from B. elkanii USDA 76 T and B. pachyrhizi PAC 48 T (88.1% and 87.9%, respectively). Fatty acid profiles [majority C 16:0 and Summed feature 8 (18:1ω6c/18:1ω7c) for both groups], DNA G + C content, and carbon compound utilization supported the placement of the novel strains in the genus Bradyrhizobium. Gene nodC and nifH of the new strains have in general low similarity with other Bradyrhizobium species. Both groups nodulated plants from the tribes Crotalarieae, Dalbergiae, Genisteae, and Phaseoleae. Based on the presented data, two novel species which the names Bradyrhizobium centrolobii and Bradyrhizobium macuxiense are proposed, with BR 10245 T (=HAMBI 3597 T ) and BR 10303 T (=HAMBI 3602 T ) as the respective-type strains.

Multi-Step Ka/Ka Dichroic Plate with Rounded Corners for NASA's 34m Beam Waveguide Antenna

NASA Technical Reports Server (NTRS)

Veruttipong, Watt; Khayatian, Behrouz; Hoppe, Daniel; Long, Ezra

2013-01-01

A multi-step Ka/Ka dichroic plate Frequency Selective Surface (FSS structure) is designed, manufactured and tested for use in NASA's Deep Space Network (DSN) 34m Beam Waveguide (BWG) antennas. The proposed design allows ease of manufacturing and ability to handle the increased transmit power (reflected off the FSS) of the DSN BWG antennas from 20kW to 100 kW. The dichroic is designed using HFSS and results agree well with measured data considering the manufacturing tolerances that could be achieved on the dichroic.

Rapid habitability assessment of Mars samples by pyrolysis-FTIR

NASA Astrophysics Data System (ADS)

Gordon, Peter R.; Sephton, Mark A.

2016-02-01

Pyrolysis Fourier transform infrared spectroscopy (pyrolysis FTIR) is a potential sample selection method for Mars Sample Return missions. FTIR spectroscopy can be performed on solid and liquid samples but also on gases following preliminary thermal extraction, pyrolysis or gasification steps. The detection of hydrocarbon and non-hydrocarbon gases can reveal information on sample mineralogy and past habitability of the environment in which the sample was created. The absorption of IR radiation at specific wavenumbers by organic functional groups can indicate the presence and type of any organic matter present. Here we assess the utility of pyrolysis-FTIR to release water, carbon dioxide, sulfur dioxide and organic matter from Mars relevant materials to enable a rapid habitability assessment of target rocks for sample return. For our assessment a range of minerals were analyzed by attenuated total reflectance FTIR. Subsequently, the mineral samples were subjected to single step pyrolysis and multi step pyrolysis and the products characterised by gas phase FTIR. Data from both single step and multi step pyrolysis-FTIR provide the ability to identify minerals that reflect habitable environments through their water and carbon dioxide responses. Multi step pyrolysis-FTIR can be used to gain more detailed information on the sources of the liberated water and carbon dioxide owing to the characteristic decomposition temperatures of different mineral phases. Habitation can be suggested when pyrolysis-FTIR indicates the presence of organic matter within the sample. Pyrolysis-FTIR, therefore, represents an effective method to assess whether Mars Sample Return target rocks represent habitable conditions and potential records of habitation and can play an important role in sample triage operations.

Employing Simulation to Evaluate Designs: The APEX Approach

NASA Technical Reports Server (NTRS)

Freed, Michael A.; Shafto, Michael G.; Remington, Roger W.; Null, Cynthia H. (Technical Monitor)

1998-01-01

The key innovations of APEX are its integrated approaches to task analysis, procedure definition, and intelligent, resource-constrained multi-tasking. This paper presents a step-by-step description of how APEX is used, from scenario development through trace analysis.

Two-Step Multi-Physics Analysis of an Annular Linear Induction Pump for Fission Power Systems

NASA Technical Reports Server (NTRS)

Geng, Steven M.; Reid, Terry V.

2016-01-01

One of the key technologies associated with fission power systems (FPS) is the annular linear induction pump (ALIP). ALIPs are used to circulate liquid-metal fluid for transporting thermal energy from the nuclear reactor to the power conversion device. ALIPs designed and built to date for FPS project applications have not performed up to expectations. A unique, two-step approach was taken toward the multi-physics examination of an ALIP using ANSYS Maxwell 3D and Fluent. This multi-physics approach was developed so that engineers could investigate design variations that might improve pump performance. Of interest was to determine if simple geometric modifications could be made to the ALIP components with the goal of increasing the Lorentz forces acting on the liquid-metal fluid, which in turn would increase pumping capacity. The multi-physics model first calculates the Lorentz forces acting on the liquid metal fluid in the ALIP annulus. These forces are then used in a computational fluid dynamics simulation as (a) internal boundary conditions and (b) source functions in the momentum equations within the Navier-Stokes equations. The end result of the two-step analysis is a predicted pump pressure rise that can be compared with experimental data.

Multi-step cure kinetic model of ultra-thin glass fiber epoxy prepreg exhibiting both autocatalytic and diffusion-controlled regimes under isothermal and dynamic-heating conditions

NASA Astrophysics Data System (ADS)

Kim, Ye Chan; Min, Hyunsung; Hong, Sungyong; Wang, Mei; Sun, Hanna; Park, In-Kyung; Choi, Hyouk Ryeol; Koo, Ja Choon; Moon, Hyungpil; Kim, Kwang J.; Suhr, Jonghwan; Nam, Jae-Do

2017-08-01

As packaging technologies are demanded that reduce the assembly area of substrate, thin composite laminate substrates require the utmost high performance in such material properties as the coefficient of thermal expansion (CTE), and stiffness. Accordingly, thermosetting resin systems, which consist of multiple fillers, monomers and/or catalysts in thermoset-based glass fiber prepregs, are extremely complicated and closely associated with rheological properties, which depend on the temperature cycles for cure. For the process control of these complex systems, it is usually required to obtain a reliable kinetic model that could be used for the complex thermal cycles, which usually includes both the isothermal and dynamic-heating segments. In this study, an ultra-thin prepreg with highly loaded silica beads and glass fibers in the epoxy/amine resin system was investigated as a model system by isothermal/dynamic heating experiments. The maximum degree of cure was obtained as a function of temperature. The curing kinetics of the model prepreg system exhibited a multi-step reaction and a limited conversion as a function of isothermal curing temperatures, which are often observed in epoxy cure system because of the rate-determining diffusion of polymer chain growth. The modified kinetic equation accurately described the isothermal behavior and the beginning of the dynamic-heating behavior by integrating the obtained maximum degree of cure into the kinetic model development.

Correction of phase errors in quantitative water-fat imaging using a monopolar time-interleaved multi-echo gradient echo sequence.

PubMed

Ruschke, Stefan; Eggers, Holger; Kooijman, Hendrik; Diefenbach, Maximilian N; Baum, Thomas; Haase, Axel; Rummeny, Ernst J; Hu, Houchun H; Karampinos, Dimitrios C

2017-09-01

To propose a phase error correction scheme for monopolar time-interleaved multi-echo gradient echo water-fat imaging that allows accurate and robust complex-based quantification of the proton density fat fraction (PDFF). A three-step phase correction scheme is proposed to address a) a phase term induced by echo misalignments that can be measured with a reference scan using reversed readout polarity, b) a phase term induced by the concomitant gradient field that can be predicted from the gradient waveforms, and c) a phase offset between time-interleaved echo trains. Simulations were carried out to characterize the concomitant gradient field-induced PDFF bias and the performance estimating the phase offset between time-interleaved echo trains. Phantom experiments and in vivo liver and thigh imaging were performed to study the relevance of each of the three phase correction steps on PDFF accuracy and robustness. The simulation, phantom, and in vivo results showed in agreement with the theory an echo time-dependent PDFF bias introduced by the three phase error sources. The proposed phase correction scheme was found to provide accurate PDFF estimation independent of the employed echo time combination. Complex-based time-interleaved water-fat imaging was found to give accurate and robust PDFF measurements after applying the proposed phase error correction scheme. Magn Reson Med 78:984-996, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

In situ UV curable 3D printing of multi-material tri-legged soft bot with spider mimicked multi-step forward dynamic gait

NASA Astrophysics Data System (ADS)

Zeb Gul, Jahan; Yang, Bong-Su; Yang, Young Jin; Chang, Dong Eui; Choi, Kyung Hyun

2016-11-01

Soft bots have the expedient ability of adopting intricate postures and fitting in complex shapes compared to mechanical robots. This paper presents a unique in situ UV curing three-dimensional (3D) printed multi-material tri-legged soft bot with spider mimicked multi-step dynamic forward gait using commercial bio metal filament (BMF) as an actuator. The printed soft bot can produce controllable forward motion in response to external signals. The fundamental properties of BMF, including output force, contractions at different frequencies, initial loading rate, and displacement-rate are verified. The tri-pedal soft bot CAD model is designed inspired by spider’s legged structure and its locomotion is assessed by simulating strain and displacement using finite element analysis. A customized rotational multi-head 3D printing system assisted with multiple wavelength’s curing lasers is used for in situ fabrication of tri-pedal soft-bot using two flexible materials (epoxy and polyurethane) in three layered steps. The size of tri-pedal soft-bot is 80 mm in diameter and each pedal’s width and depth is 5 mm × 5 mm respectively. The maximum forward speed achieved is 2.7 mm s-1 @ 5 Hz with input voltage of 3 V and 250 mA on a smooth surface. The fabricated tri-pedal soft bot proved its power efficiency and controllable locomotion at three input signal frequencies (1, 2, 5 Hz).

Multi-step process for concentrating magnetic particles in waste sludges

DOEpatents

Watson, John L.

1990-01-01

This invention involves a multi-step, multi-force process for dewatering sludges which have high concentrations of magnetic particles, such as waste sludges generated during steelmaking. This series of processing steps involves (1) mixing a chemical flocculating agent with the sludge; (2) allowing the particles to aggregate under non-turbulent conditions; (3) subjecting the mixture to a magnetic field which will pull the magnetic aggregates in a selected direction, causing them to form a compacted sludge; (4) preferably, decanting the clarified liquid from the compacted sludge; and (5) using filtration to convert the compacted sludge into a cake having a very high solids content. Steps 2 and 3 should be performed simultaneously. This reduces the treatment time and increases the extent of flocculation and the effectiveness of the process. As partially formed aggregates with active flocculating groups are pulled through the mixture by the magnetic field, they will contact other particles and form larger aggregates. This process can increase the solids concentration of steelmaking sludges in an efficient and economic manner, thereby accomplishing either of two goals: (a) it can convert hazardous wastes into economic resources for recycling as furnace feed material, or (b) it can dramatically reduce the volume of waste material which must be disposed.

Multi-step process for concentrating magnetic particles in waste sludges

DOEpatents

Watson, J.L.

1990-07-10

This invention involves a multi-step, multi-force process for dewatering sludges which have high concentrations of magnetic particles, such as waste sludges generated during steelmaking. This series of processing steps involves (1) mixing a chemical flocculating agent with the sludge; (2) allowing the particles to aggregate under non-turbulent conditions; (3) subjecting the mixture to a magnetic field which will pull the magnetic aggregates in a selected direction, causing them to form a compacted sludge; (4) preferably, decanting the clarified liquid from the compacted sludge; and (5) using filtration to convert the compacted sludge into a cake having a very high solids content. Steps 2 and 3 should be performed simultaneously. This reduces the treatment time and increases the extent of flocculation and the effectiveness of the process. As partially formed aggregates with active flocculating groups are pulled through the mixture by the magnetic field, they will contact other particles and form larger aggregates. This process can increase the solids concentration of steelmaking sludges in an efficient and economic manner, thereby accomplishing either of two goals: (a) it can convert hazardous wastes into economic resources for recycling as furnace feed material, or (b) it can dramatically reduce the volume of waste material which must be disposed. 7 figs.

Image Description with Local Patterns: An Application to Face Recognition

NASA Astrophysics Data System (ADS)

Zhou, Wei; Ahrary, Alireza; Kamata, Sei-Ichiro

In this paper, we propose a novel approach for presenting the local features of digital image using 1D Local Patterns by Multi-Scans (1DLPMS). We also consider the extentions and simplifications of the proposed approach into facial images analysis. The proposed approach consists of three steps. At the first step, the gray values of pixels in image are represented as a vector giving the local neighborhood intensity distrubutions of the pixels. Then, multi-scans are applied to capture different spatial information on the image with advantage of less computation than other traditional ways, such as Local Binary Patterns (LBP). The second step is encoding the local features based on different encoding rules using 1D local patterns. This transformation is expected to be less sensitive to illumination variations besides preserving the appearance of images embedded in the original gray scale. At the final step, Grouped 1D Local Patterns by Multi-Scans (G1DLPMS) is applied to make the proposed approach computationally simpler and easy to extend. Next, we further formulate boosted algorithm to extract the most discriminant local features. The evaluated results demonstrate that the proposed approach outperforms the conventional approaches in terms of accuracy in applications of face recognition, gender estimation and facial expression.

QUICR-learning for Multi-Agent Coordination

NASA Technical Reports Server (NTRS)

Agogino, Adrian K.; Tumer, Kagan

2006-01-01

Coordinating multiple agents that need to perform a sequence of actions to maximize a system level reward requires solving two distinct credit assignment problems. First, credit must be assigned for an action taken at time step t that results in a reward at time step t > t. Second, credit must be assigned for the contribution of agent i to the overall system performance. The first credit assignment problem is typically addressed with temporal difference methods such as Q-learning. The second credit assignment problem is typically addressed by creating custom reward functions. To address both credit assignment problems simultaneously, we propose the "Q Updates with Immediate Counterfactual Rewards-learning" (QUICR-learning) designed to improve both the convergence properties and performance of Q-learning in large multi-agent problems. QUICR-learning is based on previous work on single-time-step counterfactual rewards described by the collectives framework. Results on a traffic congestion problem shows that QUICR-learning is significantly better than a Q-learner using collectives-based (single-time-step counterfactual) rewards. In addition QUICR-learning provides significant gains over conventional and local Q-learning. Additional results on a multi-agent grid-world problem show that the improvements due to QUICR-learning are not domain specific and can provide up to a ten fold increase in performance over existing methods.

Flow control using audio tones in resonant microfluidic networks: towards cell-phone controlled lab-on-a-chip devices.

PubMed

Phillips, Reid H; Jain, Rahil; Browning, Yoni; Shah, Rachana; Kauffman, Peter; Dinh, Doan; Lutz, Barry R

2016-08-16

Fluid control remains a challenge in development of portable lab-on-a-chip devices. Here, we show that microfluidic networks driven by single-frequency audio tones create resonant oscillating flow that is predicted by equivalent electrical circuit models. We fabricated microfluidic devices with fluidic resistors (R), inductors (L), and capacitors (C) to create RLC networks with band-pass resonance in the audible frequency range available on portable audio devices. Microfluidic devices were fabricated from laser-cut adhesive plastic, and a "buzzer" was glued to a diaphragm (capacitor) to integrate the actuator on the device. The AC flowrate magnitude was measured by imaging oscillation of bead tracers to allow direct comparison to the RLC circuit model across the frequency range. We present a systematic build-up from single-channel systems to multi-channel (3-channel) networks, and show that RLC circuit models predict complex frequency-dependent interactions within multi-channel networks. Finally, we show that adding flow rectifying valves to the network creates pumps that can be driven by amplified and non-amplified audio tones from common audio devices (iPod and iPhone). This work shows that RLC circuit models predict resonant flow responses in multi-channel fluidic networks as a step towards microfluidic devices controlled by audio tones.

Analysis of shockless dynamic compression data on solids to multi-megabar pressures: Application to tantalum

DOE PAGES

Davis, Jean -Paul; Brown, Justin L.; Knudson, Marcus D.; ...

2014-11-26

In this research, magnetically-driven, planar shockless-compression experiments to multi-megabar pressures were performed on tantalum samples using a stripline target geometry. Free-surface velocity waveforms were measured in 15 cases; nine of these in a dual-sample configuration with two samples of different thicknesses on opposing electrodes, and six in a single-sample configuration with a bare electrode opposite the sample. Details are given on the application of inverse Lagrangian analysis (ILA) to these data, including potential sources of error. The most significant source of systematic error, particularly for single-sample experiments, was found to arise from the pulse-shape dependent free-surface reflected wave interactions withmore » the deviatoric-stress response of tantalum. This could cause local, possibly temporary, unloading of material from a ramp compressed state, and thus multi-value response in wave speed that invalidates the free-surface to in-material velocity mapping step of ILA. By averaging all 15 data sets, a final result for the principal quasi-isentrope of tantalum in stress-strain was obtained to a peak longitudinal stress of 330 GPa with conservative uncertainty bounds of ±4.5% in stress. The result agrees well with a tabular equation of state developed at Los Alamos National Laboratory.« less

A Spectral Multi-Domain Penalty Method for Elliptic Problems Arising From a Time-Splitting Algorithm For the Incompressible Navier-Stokes Equations

NASA Astrophysics Data System (ADS)

Diamantopoulos, Theodore; Rowe, Kristopher; Diamessis, Peter

2017-11-01

The Collocation Penalty Method (CPM) solves a PDE on the interior of a domain, while weakly enforcing boundary conditions at domain edges via penalty terms, and naturally lends itself to high-order and multi-domain discretization. Such spectral multi-domain penalty methods (SMPM) have been used to solve the Navier-Stokes equations. Bounds for penalty coefficients are typically derived using the energy method to guarantee stability for time-dependent problems. The choice of collocation points and penalty parameter can greatly affect the conditioning and accuracy of a solution. Effort has been made in recent years to relate various high-order methods on multiple elements or domains under the umbrella of the Correction Procedure via Reconstruction (CPR). Most applications of CPR have focused on solving the compressible Navier-Stokes equations using explicit time-stepping procedures. A particularly important aspect which is still missing in the context of the SMPM is a study of the Helmholtz equation arising in many popular time-splitting schemes for the incompressible Navier-Stokes equations. Stability and convergence results for the SMPM for the Helmholtz equation will be presented. Emphasis will be placed on the efficiency and accuracy of high-order methods.

A multi-level analysis of counselor attitudes toward the use of buprenorphine in substance abuse treatment.

PubMed

Rieckmann, Traci R; Kovas, Anne E; McFarland, Bentson H; Abraham, Amanda J

2011-12-01

Despite evidence that buprenorphine is effective and safe and offers greater access as compared with methadone, implementation for treatment of opiate dependence continues to be weak. Research indicates that legal and regulatory factors, state policies, and organizational and provider variables affect adoption of buprenorphine. This study uses hierarchical linear modeling to examine National Treatment Center Study data to identify counselor characteristics (attitudes, training, and beliefs) and organizational factors (accreditation, caseload, access to buprenorphine, and other evidence-based practices) that influence implementation of buprenorphine for treatment of opiate dependence. Analyses showed that provider training about buprenorphine, higher prevalence of opiate-dependent clients, and less treatment program emphasis on a 12-step model predicted greater counselor acceptance and perceived effectiveness of buprenorphine. Results also indicate that program use of buprenorphine for any treatment purpose (detoxification, maintenance, and/or pain management) and time (calendar year in data collection) was associated with increased diffusion of knowledge about buprenorphine among counselors and with more favorable counselor attitudes toward buprenorphine. Copyright © 2011 Elsevier Inc. All rights reserved.

Counselor Attitudes toward the Use of Buprenorphine in Substance Abuse Treatment: A Multi-level Modeling Approach

PubMed Central

Kovas, Anne E.; McFarland, Bentson H.; Abraham, Amanda J.

2012-01-01

In spite of evidence that buprenorphine is effective, safe, and offers greater access as compared with methadone, implementation for treatment of opiate dependence continues to be weak. Research indicates that legal and regulatory factors, state policies, and organizational and provider variables affect adoption of buprenorphine. This study uses hierarchical linear modeling (HLM) to examine National Treatment Center Study (NTCS) data to identify counselor characteristics (attitudes, training, beliefs) and organizational factors (accreditation, caseload, access to buprenorphine and other evidence-based practices) that influence implementation of buprenorphine for treatment of opiate dependence. Analyses showed that provider training about buprenorphine, higher prevalence of opiate dependent clients, and less treatment program emphasis on a 12-step model predicted greater counselor acceptance and perceived effectiveness of buprenorphine. Results also indicate that program use of buprenorphine for any treatment purpose (detoxification, maintenance, and/or pain management) and time (calendar year in data collection) were associated with increased diffusion of knowledge about buprenorphine among counselors and with more favorable counselor attitudes toward buprenorphine. PMID:21821379

Computationally efficient approach for solving time dependent diffusion equation with discrete temporal convolution applied to granular particles of battery electrodes

NASA Astrophysics Data System (ADS)

Senegačnik, Jure; Tavčar, Gregor; Katrašnik, Tomaž

2015-03-01

The paper presents a computationally efficient method for solving the time dependent diffusion equation in a granule of the Li-ion battery's granular solid electrode. The method, called Discrete Temporal Convolution method (DTC), is based on a discrete temporal convolution of the analytical solution of the step function boundary value problem. This approach enables modelling concentration distribution in the granular particles for arbitrary time dependent exchange fluxes that do not need to be known a priori. It is demonstrated in the paper that the proposed method features faster computational times than finite volume/difference methods and Padé approximation at the same accuracy of the results. It is also demonstrated that all three addressed methods feature higher accuracy compared to the quasi-steady polynomial approaches when applied to simulate the current densities variations typical for mobile/automotive applications. The proposed approach can thus be considered as one of the key innovative methods enabling real-time capability of the multi particle electrochemical battery models featuring spatial and temporal resolved particle concentration profiles.

A multi-step strategy to obtain crystals of the dengue virus RNA-dependent RNA polymerase that diffract to high resolution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yap, Thai Leong; School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551; Chen, Yen Liang

Crystals of the RNA-dependent RNA polymerase catalytic domain from the dengue virus NS5 protein have been obtained using a strategy that included expression screening of naturally occurring serotype variants of the protein, the addition of divalent metal ions and crystal dehydration. These crystals diffract to 1.85 Å resolution and are thus suitable for a structure-based drug-design program. Dengue virus, a member of the Flaviviridae genus, causes dengue fever, an important emerging disease with several million infections occurring annually for which no effective therapy exists. The viral RNA-dependent RNA polymerase NS5 plays an important role in virus replication and represents anmore » interesting target for the development of specific antiviral compounds. Crystals that diffract to 1.85 Å resolution that are suitable for three-dimensional structure determination and thus for a structure-based drug-design program have been obtained using a strategy that included expression screening of naturally occurring serotype variants of the protein, the addition of divalent metal ions and crystal dehydration.« less

Metaphase II oocytes from human unilaminar follicles grown in a multi-step culture system.

PubMed

McLaughlin, M; Albertini, D F; Wallace, W H B; Anderson, R A; Telfer, E E

2018-03-01

Can complete oocyte development be achieved from human ovarian tissue containing primordial/unilaminar follicles and grown in vitro in a multi-step culture to meiotic maturation demonstrated by the formation of polar bodies and a Metaphase II spindle? Development of human oocytes from primordial/unilaminar stages to resumption of meiosis (Metaphase II) and emission of a polar body was achieved within a serum free multi-step culture system. Complete development of oocytes in vitro has been achieved in mouse, where in vitro grown (IVG) oocytes from primordial follicles have resulted in the production of live offspring. Human oocytes have been grown in vitro from the secondary/multi-laminar stage to obtain fully grown oocytes capable of meiotic maturation. However, there are no reports of a culture system supporting complete growth from the earliest stages of human follicle development through to Metaphase II. Ovarian cortical biopsies were obtained with informed consent from women undergoing elective caesarean section (mean age: 30.7 ± 1.7; range: 25-39 years, n = 10). Laboratory setting. Ovarian biopsies were dissected into thin strips, and after removal of growing follicles were cultured in serum free medium for 8 days (Step 1). At the end of this period secondary/multi-laminar follicles were dissected from the strips and intact follicles 100-150 μm in diameter were selected for further culture. Isolated follicles were cultured individually in serum free medium in the presence of 100 ng/ml of human recombinant Activin A (Step 2). Individual follicles were monitored and after 8 days, cumulus oocyte complexes (COCs) were retrieved by gentle pressure on the cultured follicles. Complexes with complete cumulus and adherent mural granulosa cells were selected and cultured in the presence of Activin A and FSH on membranes for a further 4 days (Step 3). At the end of Step 3, complexes containing oocytes >100 μm diameter were selected for IVM in SAGE medium (Step 4) then fixed for analysis. Pieces of human ovarian cortex cultured in serum free medium for 8 days (Step 1) supported early follicle growth and 87 secondary follicles of diameter 120 ± 6 μm (mean ± SEM) could be dissected for further culture. After a further 8 days, 54 of the 87 follicles had reached the antral stage of development. COCs were retrieved by gentle pressure from the cultured follicles and those with adherent mural granulosa cells (n = 48) were selected and cultured for a further 4 days (Step 3). At the end of Step 3, 32 complexes contained oocytes >100 μm diameter were selected for IVM (Step 4). Nine of these complexes contained polar bodies within 24 h and all polar bodies were abnormally large. Confocal immuno-histochemical analysis showed the presence of a Metaphase II spindle confirming that these IVG oocytes had resumed meiosis but their developmental potential is unknown. This is a small number of samples but provides proof of concept that complete development of human oocytes can occur in vitro. Further optimization with morphological evaluation and fertilization potential of IVG oocytes is required to determine whether they are normal. The ability to develop human oocytes from the earliest follicular stages in vitro through to maturation and fertilization would benefit fertility preservation practice. Funded by MRC Grants (G0901839 and MR/L00299X/1). No competing interests.

Multi-Species Fluxes for the Parallel Quiet Direct Simulation (QDS) Method

NASA Astrophysics Data System (ADS)

Cave, H. M.; Lim, C.-W.; Jermy, M. C.; Krumdieck, S. P.; Smith, M. R.; Lin, Y.-J.; Wu, J.-S.

2011-05-01

Fluxes of multiple species are implemented in the Quiet Direct Simulation (QDS) scheme for gas flows. Each molecular species streams independently. All species are brought to local equilibrium at the end of each time step. The multi species scheme is compared to DSMC simulation, on a test case of a Mach 20 flow of a xenon/helium mixture over a forward facing step. Depletion of the heavier species in the bow shock and the near-wall layer are seen. The multi-species QDS code is then used to model the flow in a pulsed-pressure chemical vapour deposition reactor set up for carbon film deposition. The injected gas is a mixture of methane and hydrogen. The temporal development of the spatial distribution of methane over the substrate is tracked.

Efficient high-order structure-preserving methods for the generalized Rosenau-type equation with power law nonlinearity

NASA Astrophysics Data System (ADS)

Cai, Jiaxiang; Liang, Hua; Zhang, Chun

2018-06-01

Based on the multi-symplectic Hamiltonian formula of the generalized Rosenau-type equation, a multi-symplectic scheme and an energy-preserving scheme are proposed. To improve the accuracy of the solution, we apply the composition technique to the obtained schemes to develop high-order schemes which are also multi-symplectic and energy-preserving respectively. Discrete fast Fourier transform makes a significant improvement to the computational efficiency of schemes. Numerical results verify that all the proposed schemes have satisfactory performance in providing accurate solution and preserving the discrete mass and energy invariants. Numerical results also show that although each basic time step is divided into several composition steps, the computational efficiency of the composition schemes is much higher than that of the non-composite schemes.

Multi-Object Tracking with Correlation Filter for Autonomous Vehicle.

PubMed

Zhao, Dawei; Fu, Hao; Xiao, Liang; Wu, Tao; Dai, Bin

2018-06-22

Multi-object tracking is a crucial problem for autonomous vehicle. Most state-of-the-art approaches adopt the tracking-by-detection strategy, which is a two-step procedure consisting of the detection module and the tracking module. In this paper, we improve both steps. We improve the detection module by incorporating the temporal information, which is beneficial for detecting small objects. For the tracking module, we propose a novel compressed deep Convolutional Neural Network (CNN) feature based Correlation Filter tracker. By carefully integrating these two modules, the proposed multi-object tracking approach has the ability of re-identification (ReID) once the tracked object gets lost. Extensive experiments were performed on the KITTI and MOT2015 tracking benchmarks. Results indicate that our approach outperforms most state-of-the-art tracking approaches.

Automated Geo/Co-Registration of Multi-Temporal Very-High-Resolution Imagery.

PubMed

Han, Youkyung; Oh, Jaehong

2018-05-17

For time-series analysis using very-high-resolution (VHR) multi-temporal satellite images, both accurate georegistration to the map coordinates and subpixel-level co-registration among the images should be conducted. However, applying well-known matching methods, such as scale-invariant feature transform and speeded up robust features for VHR multi-temporal images, has limitations. First, they cannot be used for matching an optical image to heterogeneous non-optical data for georegistration. Second, they produce a local misalignment induced by differences in acquisition conditions, such as acquisition platform stability, the sensor's off-nadir angle, and relief displacement of the considered scene. Therefore, this study addresses the problem by proposing an automated geo/co-registration framework for full-scene multi-temporal images acquired from a VHR optical satellite sensor. The proposed method comprises two primary steps: (1) a global georegistration process, followed by (2) a fine co-registration process. During the first step, two-dimensional multi-temporal satellite images are matched to three-dimensional topographic maps to assign the map coordinates. During the second step, a local analysis of registration noise pixels extracted between the multi-temporal images that have been mapped to the map coordinates is conducted to extract a large number of well-distributed corresponding points (CPs). The CPs are finally used to construct a non-rigid transformation function that enables minimization of the local misalignment existing among the images. Experiments conducted on five Kompsat-3 full scenes confirmed the effectiveness of the proposed framework, showing that the georegistration performance resulted in an approximately pixel-level accuracy for most of the scenes, and the co-registration performance further improved the results among all combinations of the georegistered Kompsat-3 image pairs by increasing the calculated cross-correlation values.

A multi-layer steganographic method based on audio time domain segmented and network steganography

NASA Astrophysics Data System (ADS)

Xue, Pengfei; Liu, Hanlin; Hu, Jingsong; Hu, Ronggui

2018-05-01

Both audio steganography and network steganography are belong to modern steganography. Audio steganography has a large capacity. Network steganography is difficult to detect or track. In this paper, a multi-layer steganographic method based on the collaboration of them (MLS-ATDSS&NS) is proposed. MLS-ATDSS&NS is realized in two covert layers (audio steganography layer and network steganography layer) by two steps. A new audio time domain segmented steganography (ATDSS) method is proposed in step 1, and the collaboration method of ATDSS and NS is proposed in step 2. The experimental results showed that the advantage of MLS-ATDSS&NS over others is better trade-off between capacity, anti-detectability and robustness, that means higher steganographic capacity, better anti-detectability and stronger robustness.

Comparison of microbial community shifts in two parallel multi-step drinking water treatment processes.

PubMed

Xu, Jiajiong; Tang, Wei; Ma, Jun; Wang, Hong

2017-07-01

Drinking water treatment processes remove undesirable chemicals and microorganisms from source water, which is vital to public health protection. The purpose of this study was to investigate the effects of treatment processes and configuration on the microbiome by comparing microbial community shifts in two series of different treatment processes operated in parallel within a full-scale drinking water treatment plant (DWTP) in Southeast China. Illumina sequencing of 16S rRNA genes of water samples demonstrated little effect of coagulation/sedimentation and pre-oxidation steps on bacterial communities, in contrast to dramatic and concurrent microbial community shifts during ozonation, granular activated carbon treatment, sand filtration, and disinfection for both series. A large number of unique operational taxonomic units (OTUs) at these four treatment steps further illustrated their strong shaping power towards the drinking water microbial communities. Interestingly, multidimensional scaling analysis revealed tight clustering of biofilm samples collected from different treatment steps, with Nitrospira, the nitrite-oxidizing bacteria, noted at higher relative abundances in biofilm compared to water samples. Overall, this study provides a snapshot of step-to-step microbial evolvement in multi-step drinking water treatment systems, and the results provide insight to control and manipulation of the drinking water microbiome via optimization of DWTP design and operation.

Scale effect challenges in urban hydrology highlighted with a distributed hydrological model

NASA Astrophysics Data System (ADS)

Ichiba, Abdellah; Gires, Auguste; Tchiguirinskaia, Ioulia; Schertzer, Daniel; Bompard, Philippe; Ten Veldhuis, Marie-Claire

2018-01-01

Hydrological models are extensively used in urban water management, development and evaluation of future scenarios and research activities. There is a growing interest in the development of fully distributed and grid-based models. However, some complex questions related to scale effects are not yet fully understood and still remain open issues in urban hydrology. In this paper we propose a two-step investigation framework to illustrate the extent of scale effects in urban hydrology. First, fractal tools are used to highlight the scale dependence observed within distributed data input into urban hydrological models. Then an intensive multi-scale modelling work is carried out to understand scale effects on hydrological model performance. Investigations are conducted using a fully distributed and physically based model, Multi-Hydro, developed at Ecole des Ponts ParisTech. The model is implemented at 17 spatial resolutions ranging from 100 to 5 m. Results clearly exhibit scale effect challenges in urban hydrology modelling. The applicability of fractal concepts highlights the scale dependence observed within distributed data. Patterns of geophysical data change when the size of the observation pixel changes. The multi-scale modelling investigation confirms scale effects on hydrological model performance. Results are analysed over three ranges of scales identified in the fractal analysis and confirmed through modelling. This work also discusses some remaining issues in urban hydrology modelling related to the availability of high-quality data at high resolutions, and model numerical instabilities as well as the computation time requirements. The main findings of this paper enable a replacement of traditional methods of model calibration by innovative methods of model resolution alteration based on the spatial data variability and scaling of flows in urban hydrology.

Multi-scale Slip Inversion Based on Simultaneous Spatial and Temporal Domain Wavelet Transform

NASA Astrophysics Data System (ADS)

Liu, W.; Yao, H.; Yang, H. Y.

2017-12-01

Finite fault inversion is a widely used method to study earthquake rupture processes. Some previous studies have proposed different methods to implement finite fault inversion, including time-domain, frequency-domain, and wavelet-domain methods. Many previous studies have found that different frequency bands show different characteristics of the seismic rupture (e.g., Wang and Mori, 2011; Yao et al., 2011, 2013; Uchide et al., 2013; Yin et al., 2017). Generally, lower frequency waveforms correspond to larger-scale rupture characteristics while higher frequency data are representative of smaller-scale ones. Therefore, multi-scale analysis can help us understand the earthquake rupture process thoroughly from larger scale to smaller scale. By the use of wavelet transform, the wavelet-domain methods can analyze both the time and frequency information of signals in different scales. Traditional wavelet-domain methods (e.g., Ji et al., 2002) implement finite fault inversion with both lower and higher frequency signals together to recover larger-scale and smaller-scale characteristics of the rupture process simultaneously. Here we propose an alternative strategy with a two-step procedure, i.e., firstly constraining the larger-scale characteristics with lower frequency signals, and then resolving the smaller-scale ones with higher frequency signals. We have designed some synthetic tests to testify our strategy and compare it with the traditional one. We also have applied our strategy to study the 2015 Gorkha Nepal earthquake using tele-seismic waveforms. Both the traditional method and our two-step strategy only analyze the data in different temporal scales (i.e., different frequency bands), while the spatial distribution of model parameters also shows multi-scale characteristics. A more sophisticated strategy is to transfer the slip model into different spatial scales, and then analyze the smooth slip distribution (larger scales) with lower frequency data firstly and more detailed slip distribution (smaller scales) with higher frequency data subsequently. We are now implementing the slip inversion using both spatial and temporal domain wavelets. This multi-scale analysis can help us better understand frequency-dependent rupture characteristics of large earthquakes.

Lignocellulose hydrolysis by multienzyme complexes

USDA-ARS?s Scientific Manuscript database

Lignocellulosic biomass is the most abundant renewable resource on the planet. Converting this material into a usable fuel is a multi-step process, the rate-limiting step being enzymatic hydrolysis of organic polymers into monomeric sugars. While the substrate can be complex and require a multitud...

GIST Clinic Application 2018 | Center for Cancer Research

Cancer.gov

Clinic date: June 20-22, 2018 This Application is the first step in a multi-step process for being considered for participation in our upcoming Pediatric and wild-type GIST clinic. Please review all 3 pages and complete all questions in full.

Influence of tryptophan and related compounds on ergot alkaloid formation in Claviceps purpurea (FR.) Tul.

PubMed

Erge, D; Schumann, B; Gröger, D

1984-01-01

L-Tryptophan did not exert any influence on peptide alkaloid formation in an ergotamine and in an ergosine-accumulating C. purpurea strain. A different picture was observed in a series of related C. purpurea strains. Tryptophan showed a slight stimulatory effect on the ergotoxine producer Pepty 695/S. A blocked mutant of it, designated as Pepty 695/ch which was able to accumulate secoclavines gave similar results. In a high-yielding elymoclavine strain Pepty 695/e, the progeny of the former one, tryptophan up to a concentration of 25 mM stimulated remarkably clavine biosynthesis. Furthermore, tryptophan could overcome the block of synthesis by inorganic phosphate. Increased specific activities of chanoclavine cyclase but not DMAT synthetase were observed in cultures of strain Pepty 695/e supplemented with tryptophan. 5-Methyltryptophan and bioisosteres of tryptophan were ineffective in alkaloid stimulation. These results are compared with those obtained with the grass ergot strain SD 58 and discussed with the relation to other induction phenomena.

Technical note: Equivalent genomic models with a residual polygenic effect.

PubMed

Liu, Z; Goddard, M E; Hayes, B J; Reinhardt, F; Reents, R

2016-03-01

Routine genomic evaluations in animal breeding are usually based on either a BLUP with genomic relationship matrix (GBLUP) or single nucleotide polymorphism (SNP) BLUP model. For a multi-step genomic evaluation, these 2 alternative genomic models were proven to give equivalent predictions for genomic reference animals. The model equivalence was verified also for young genotyped animals without phenotypes. Due to incomplete linkage disequilibrium of SNP markers to genes or causal mutations responsible for genetic inheritance of quantitative traits, SNP markers cannot explain all the genetic variance. A residual polygenic effect is normally fitted in the genomic model to account for the incomplete linkage disequilibrium. In this study, we start by showing the proof that the multi-step GBLUP and SNP BLUP models are equivalent for the reference animals, when they have a residual polygenic effect included. Second, the equivalence of both multi-step genomic models with a residual polygenic effect was also verified for young genotyped animals without phenotypes. Additionally, we derived formulas to convert genomic estimated breeding values of the GBLUP model to its components, direct genomic values and residual polygenic effect. Third, we made a proof that the equivalence of these 2 genomic models with a residual polygenic effect holds also for single-step genomic evaluation. Both the single-step GBLUP and SNP BLUP models lead to equal prediction for genotyped animals with phenotypes (e.g., reference animals), as well as for (young) genotyped animals without phenotypes. Finally, these 2 single-step genomic models with a residual polygenic effect were proven to be equivalent for estimation of SNP effects, too. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Using the Binary Phase-Field Crystal Model to Describe Non-Classical Nucleation Pathways in Gold Nanoparticles

NASA Astrophysics Data System (ADS)

Smith, Nathan; Provatas, Nikolas

Recent experimental work has shown that gold nanoparticles can precipitate from an aqueous solution through a non-classical, multi-step nucleation process. This multi-step process begins with spinodal decomposition into solute-rich and solute-poor liquid domains followed by nucleation from within the solute-rich domains. We present a binary phase-field crystal theory that shows the same phenomology and examine various cross-over regimes in the growth and coarsening of liquid and solid domains. We'd like to the thank Canada Research Chairs (CRC) program for funding this work.

Multi-catalysis cascade reactions based on the methoxycarbonylketene platform: diversity-oriented synthesis of functionalized non-symmetrical malonates for agrochemicals and pharmaceuticals.

PubMed

Ramachary, Dhevalapally B; Venkaiah, Chintalapudi; Reddy, Y Vijayendar; Kishor, Mamillapalli

2009-05-21

In this paper we describe new multi-catalysis cascade (MCC) reactions for the one-pot synthesis of highly functionalized non-symmetrical malonates. These metal-free reactions are either five-step (olefination/hydrogenation/alkylation/ketenization/esterification) or six-step (olefination/hydrogenation/alkylation/ketenization/esterification/alkylation), and employ aldehydes/ketones, Meldrum's acid, 1,4-dihydropyridine/o-phenylenediamine, diazomethane, alcohols and active ethylene/acetylenes, and involve iminium-, self-, self-, self- and base-catalysis, respectively. Many of the products have direct application in agricultural and pharmaceutical chemistry.

Cryo-EM image alignment based on nonuniform fast Fourier transform.

PubMed

Yang, Zhengfan; Penczek, Pawel A

2008-08-01

In single particle analysis, two-dimensional (2-D) alignment is a fundamental step intended to put into register various particle projections of biological macromolecules collected at the electron microscope. The efficiency and quality of three-dimensional (3-D) structure reconstruction largely depends on the computational speed and alignment accuracy of this crucial step. In order to improve the performance of alignment, we introduce a new method that takes advantage of the highly accurate interpolation scheme based on the gridding method, a version of the nonuniform fast Fourier transform, and utilizes a multi-dimensional optimization algorithm for the refinement of the orientation parameters. Using simulated data, we demonstrate that by using less than half of the sample points and taking twice the runtime, our new 2-D alignment method achieves dramatically better alignment accuracy than that based on quadratic interpolation. We also apply our method to image to volume registration, the key step in the single particle EM structure refinement protocol. We find that in this case the accuracy of the method not only surpasses the accuracy of the commonly used real-space implementation, but results are achieved in much shorter time, making gridding-based alignment a perfect candidate for efficient structure determination in single particle analysis.

Detecting uniaxial single domain grains with a modified IRM technique

NASA Astrophysics Data System (ADS)

Mitra, R.; Tauxe, L.; Gee, J. S.

2011-12-01

Mid-ocean ridge basalt (MORB) specimens have often been found to have high ratios of saturation remanence to saturation magnetization (Mrs/Ms). This has been attributed either to dominant cubic anisotropy or to insufficient saturating field leading to overestimation of Mrs/Ms of a dominantly uniaxial single domain (USD) assemblage. To resolve this debate, we develop an independent technique to detect USD assemblages. The experimental protocol involves subjecting the specimen to bidirectional impulse fields at each step. The experiment is similar to the conventional isothermal remanent magnetization (IRM) acquisition experiment but the field is applied twice, in antiparallel directions. We define a new parameter, IRAT, as the ratio of the remanences at each field step and show it to have characteristic behaviour for the two assemblages; IRAT ˜1 at all field steps for USD and <1 with a strong field dependence for multi-axial single domain (MSD) grains. We verified the theoretical predictions experimentally with representative USD and MSD specimens. Experiments with MORBs gave low IRATs for specimens having high Mrs/Ms. This argues for a dominant MSD assemblage in the MORBs, possibly cubic in nature. Although undersaturation of the samples can indeed be a contributing factor to the exceptionally high Mrs/Ms, this study shows that the nature of the assemblage cannot be dominantly USD.

Verification of kinetic schemes of hydrogen ignition and combustion in air

NASA Astrophysics Data System (ADS)

Fedorov, A. V.; Fedorova, N. N.; Vankova, O. S.; Tropin, D. A.

2018-03-01

Three chemical kinetic models for hydrogen combustion in oxygen and three gas-dynamic models for reactive mixture flow behind the initiating SW front were analyzed. The calculated results were compared with experimental data on the dependences of the ignition delay on the temperature and the dilution of the mixture with argon or nitrogen. Based on detailed kinetic mechanisms of nonequilibrium chemical transformations, a mathematical technique for describing the ignition and combustion of hydrogen in air was developed using the ANSYS Fluent code. The problem of ignition of a hydrogen jet fed coaxially into supersonic flow was solved numerically. The calculations were carried out using the Favre-averaged Navier-Stokes equations for a multi-species gas taking into account chemical reactions combined with the k-ω SST turbulence model. The problem was solved in several steps. In the first step, verification of the calculated and experimental data for the three kinetic schemes was performed without considering the conicity of the flow. In the second step, parametric calculations were performed to determine the influence of the conicity of the flow on the mixing and ignition of hydrogen in air using a kinetic scheme consisting of 38 reactions. Three conical supersonic nozzles for a Mach number M = 2 with different expansion angles β = 4°, 4.5°, and 5° were considered.

Techniques of stapler-based navigational thoracoscopic segmentectomy using virtual assisted lung mapping (VAL-MAP)

PubMed Central

Murayama, Tomonori; Nakajima, Jun

2016-01-01

Anatomical segmentectomies play an important role in oncological lung resection, particularly for ground-glass types of primary lung cancers. This operation can also be applied to metastatic lung tumors deep in the lung. Virtual assisted lung mapping (VAL-MAP) is a novel technique that allows for bronchoscopic multi-spot dye markings to provide “geometric information” to the lung surface, using three-dimensional virtual images. In addition to wedge resections, VAL-MAP has been found to be useful in thoracoscopic segmentectomies, particularly complex segmentectomies, such as combined subsegmentectomies or extended segmentectomies. There are five steps in VAL-MAP-assisted segmentectomies: (I) “standing” stitches along the resection lines; (II) cleaning hilar anatomy; (III) confirming hilar anatomy; (IV) going 1 cm deeper; (V) step-by-step stapling technique. Depending on the anatomy, segmentectomies can be classified into linear (lingular, S6, S2), V- or U-shaped (right S1, left S3, S2b + S3a), and three dimensional (S7, S8, S9, S10) segmentectomies. Particularly three dimensional segmentectomies are challenging in the complexity of stapling techniques. This review focuses on how VAL-MAP can be utilized in segmentectomy, and how this technique can assist the stapling process in even the most challenging ones. PMID:28066675

Cryo-EM Image Alignment Based on Nonuniform Fast Fourier Transform

PubMed Central

Yang, Zhengfan; Penczek, Pawel A.

2008-01-01

In single particle analysis, two-dimensional (2-D) alignment is a fundamental step intended to put into register various particle projections of biological macromolecules collected at the electron microscope. The efficiency and quality of three-dimensional (3-D) structure reconstruction largely depends on the computational speed and alignment accuracy of this crucial step. In order to improve the performance of alignment, we introduce a new method that takes advantage of the highly accurate interpolation scheme based on the gridding method, a version of the nonuniform Fast Fourier Transform, and utilizes a multi-dimensional optimization algorithm for the refinement of the orientation parameters. Using simulated data, we demonstrate that by using less than half of the sample points and taking twice the runtime, our new 2-D alignment method achieves dramatically better alignment accuracy than that based on quadratic interpolation. We also apply our method to image to volume registration, the key step in the single particle EM structure refinement protocol. We find that in this case the accuracy of the method not only surpasses the accuracy of the commonly used real-space implementation, but results are achieved in much shorter time, making gridding-based alignment a perfect candidate for efficient structure determination in single particle analysis. PMID:18499351

Tuning the resistive switching properties of TiO2-x films

NASA Astrophysics Data System (ADS)

Ghenzi, N.; Rozenberg, M. J.; Llopis, R.; Levy, P.; Hueso, L. E.; Stoliar, P.

2015-03-01

We study the electrical characteristics of TiO2-x-based resistive switching devices fabricated with different oxygen/argon flow ratio during the oxide thin film sputtering deposition. Upon minute changes in this fabrication parameter, three qualitatively different device characteristics were accessed in the same system, namely, standard bipolar resistive switching, electroforming-free devices, and devices with multi-step breakdown. We propose that small variations in the oxygen/ argon flow ratio result in relevant changes of the oxygen vacancy concentration, which is the key parameter determining the resistive switching behavior. The coexistence of percolative or non-percolative conductive filaments is also discussed. Finally, the hypothesis is verified by means of the temperature dependence of the devices in low resistance state.

Unsteady flows in rotor-stator cascades

NASA Astrophysics Data System (ADS)

Lee, Yu-Tai; Bein, Thomas W.; Feng, Jin Z.; Merkle, Charles L.

1991-03-01

A time-accurate potential-flow calculation method has been developed for unsteady incompressible flows through two-dimensional multi-blade-row linear cascades. The method represents the boundary surfaces by distributing piecewise linear-vortex and constant-source singularities on discrete panels. A local coordinate is assigned to each independently moving object. Blade-shed vorticity is traced at each time step. The unsteady Kutta condition applied is nonlinear and requires zero blade trailing-edge loading at each time. Its influence on the solutions depends on the blade trailing-edge shapes. Steady biplane and cascade solutions are presented and compared to exact solutions and experimental data. Unsteady solutions are validated with the Wagner function for an airfoil moving impulsively from rest and the Theodorsen function for an oscillating airfoil. The shed vortex motion and its interaction with blades are calculated and compared to an analytic solution. For multi-blade-row cascade, the potential effect between blade rows is predicted using steady and quasi unsteady calculations. The accuracy of the predictions is demonstrated using experimental results for a one-stage turbine stator-rotor.

Informing Aerosol Transport Models With Satellite Multi-Angle Aerosol Measurements

NASA Technical Reports Server (NTRS)

Limbacher, J.; Patadia, F.; Petrenko, M.; Martin, M. Val; Chin, M.; Gaitley, B.; Garay, M.; Kalashnikova, O.; Nelson, D.; Scollo, S.

2011-01-01

As the aerosol products from the NASA Earth Observing System's Multi-angle Imaging SpectroRadiometer (MISR) mature, we are placing greater focus on ways of using the aerosol amount and type data products, and aerosol plume heights, to constrain aerosol transport models. We have demonstrated the ability to map aerosol air-mass-types regionally, and have identified product upgrades required to apply them globally, including the need for a quality flag indicating the aerosol type information content, that varies depending upon retrieval conditions. We have shown that MISR aerosol type can distinguish smoke from dust, volcanic ash from sulfate and water particles, and can identify qualitative differences in mixtures of smoke, dust, and pollution aerosol components in urban settings. We demonstrated the use of stereo imaging to map smoke, dust, and volcanic effluent plume injection height, and the combination of MISR and MODIS aerosol optical depth maps to constrain wildfire smoke source strength. This talk will briefly highlight where we stand on these application, with emphasis on the steps we are taking toward applying the capabilities toward constraining aerosol transport models, planet-wide.

Uncovering the stoichiometry of Pyrococcus furiosus RNase P, a multi-subunit catalytic ribonucleoprotein complex, by surface-induced dissociation and ion mobility mass spectrometry.

PubMed

Ma, Xin; Lai, Lien B; Lai, Stella M; Tanimoto, Akiko; Foster, Mark P; Wysocki, Vicki H; Gopalan, Venkat

2014-10-20

We demonstrate that surface-induced dissociation (SID) coupled with ion mobility mass spectrometry (IM-MS) is a powerful tool for determining the stoichiometry of a multi-subunit ribonucleoprotein (RNP) complex assembled in a solution containing Mg(2+). We investigated Pyrococcus furiosus (Pfu) RNase P, an archaeal RNP that catalyzes tRNA 5' maturation. Previous step-wise, Mg(2+)-dependent reconstitutions of Pfu RNase P with its catalytic RNA subunit and two interacting protein cofactor pairs (RPP21⋅RPP29 and POP5⋅RPP30) revealed functional RNP intermediates en route to the RNase P enzyme, but provided no information on subunit stoichiometry. Our native MS studies with the proteins showed RPP21⋅RPP29 and (POP5⋅RPP30)2 complexes, but indicated a 1:1 composition for all subunits when either one or both protein complexes bind the cognate RNA. These results highlight the utility of SID and IM-MS in resolving conformational heterogeneity and yielding insights on RNP assembly. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effective Multi-Query Expansions: Collaborative Deep Networks for Robust Landmark Retrieval.

PubMed

Wang, Yang; Lin, Xuemin; Wu, Lin; Zhang, Wenjie

2017-03-01

Given a query photo issued by a user (q-user), the landmark retrieval is to return a set of photos with their landmarks similar to those of the query, while the existing studies on the landmark retrieval focus on exploiting geometries of landmarks for similarity matches between candidate photos and a query photo. We observe that the same landmarks provided by different users over social media community may convey different geometry information depending on the viewpoints and/or angles, and may, subsequently, yield very different results. In fact, dealing with the landmarks with low quality shapes caused by the photography of q-users is often nontrivial and has seldom been studied. In this paper, we propose a novel framework, namely, multi-query expansions, to retrieve semantically robust landmarks by two steps. First, we identify the top- k photos regarding the latent topics of a query landmark to construct multi-query set so as to remedy its possible low quality shape. For this purpose, we significantly extend the techniques of Latent Dirichlet Allocation. Then, motivated by the typical collaborative filtering methods, we propose to learn a collaborative deep networks-based semantically, nonlinear, and high-level features over the latent factor for landmark photo as the training set, which is formed by matrix factorization over collaborative user-photo matrix regarding the multi-query set. The learned deep network is further applied to generate the features for all the other photos, meanwhile resulting into a compact multi-query set within such space. Then, the final ranking scores are calculated over the high-level feature space between the multi-query set and all other photos, which are ranked to serve as the final ranking list of landmark retrieval. Extensive experiments are conducted on real-world social media data with both landmark photos together with their user information to show the superior performance over the existing methods, especially our recently proposed multi-query based mid-level pattern representation method [1].

Large-scale automated image analysis for computational profiling of brain tissue surrounding implanted neuroprosthetic devices using Python.

PubMed

Rey-Villamizar, Nicolas; Somasundar, Vinay; Megjhani, Murad; Xu, Yan; Lu, Yanbin; Padmanabhan, Raghav; Trett, Kristen; Shain, William; Roysam, Badri

2014-01-01

In this article, we describe the use of Python for large-scale automated server-based bio-image analysis in FARSIGHT, a free and open-source toolkit of image analysis methods for quantitative studies of complex and dynamic tissue microenvironments imaged by modern optical microscopes, including confocal, multi-spectral, multi-photon, and time-lapse systems. The core FARSIGHT modules for image segmentation, feature extraction, tracking, and machine learning are written in C++, leveraging widely used libraries including ITK, VTK, Boost, and Qt. For solving complex image analysis tasks, these modules must be combined into scripts using Python. As a concrete example, we consider the problem of analyzing 3-D multi-spectral images of brain tissue surrounding implanted neuroprosthetic devices, acquired using high-throughput multi-spectral spinning disk step-and-repeat confocal microscopy. The resulting images typically contain 5 fluorescent channels. Each channel consists of 6000 × 10,000 × 500 voxels with 16 bits/voxel, implying image sizes exceeding 250 GB. These images must be mosaicked, pre-processed to overcome imaging artifacts, and segmented to enable cellular-scale feature extraction. The features are used to identify cell types, and perform large-scale analysis for identifying spatial distributions of specific cell types relative to the device. Python was used to build a server-based script (Dell 910 PowerEdge servers with 4 sockets/server with 10 cores each, 2 threads per core and 1TB of RAM running on Red Hat Enterprise Linux linked to a RAID 5 SAN) capable of routinely handling image datasets at this scale and performing all these processing steps in a collaborative multi-user multi-platform environment. Our Python script enables efficient data storage and movement between computers and storage servers, logs all the processing steps, and performs full multi-threaded execution of all codes, including open and closed-source third party libraries.

Photoacoustic assay for probing amyloid formation: feasibility study

NASA Astrophysics Data System (ADS)

Petrova, Elena; Yoon, Soon Joon; Pelivanov, Ivan; O'Donnell, Matthew

2018-02-01

The formation of amyloid - aggregate of misfolded proteins - is associated with more than 50 human pathologies, including Alzheimer's disease, Parkinson's disease, and Type 2 diabetes mellitus. Investigating protein aggregation is a critical step in drug discovery and development of therapeutics targeted to these pathologies. However, screens to identify protein aggregates are challenging due to the stochastic character of aggregate nucleation. Here we employ photoacoustics (PA) to screen thermodynamic conditions and solution components leading to formation of protein aggregates. Particularly, we study the temperature dependence of the Gruneisen parameter in optically-contrasted, undersaturated and supersaturated solutions of glycoside hydrolase (lysozyme). As nucleation of protein aggregates proceeds in two steps, where the first is liquid-liquid separation (rearrangement of solute's density), the PA response from complex solutions and its temperature-dependence monitor nucleation and differentiate undersaturated and supersaturated protein solutions. We demonstrate that in the temperature range from 22 to 0° C the PA response of contrasted undersaturated protein solution behaves similar to water and exhibits zero thermal expansion at 4°C or below, while the response of contrasted supersaturated protein solution is nearly temperature independent, similar to the behavior of oils. These results can be used to develop a PA assay for high-throughput screening of multi-parametric conditions (pH, ionic strength, chaperone, etc.) for protein aggregation that can become a key tool in drug discovery, targeting aggregate formation for a variety of amyloids.

A Student Synthesis of the Housefly Sex Attractant.

ERIC Educational Resources Information Center

Cormier, Russell; And Others

1979-01-01

A novel and efficient (34 percent overall) multi-step synthesis of the housefly sex attractant, muscalure, is described. Each of the steps involves types of reactions with which the undergraduate student would be familiar after one-and-one-half semesters of organic chemistry. (BB)

Heat damaged forages: effects on forage energy content

USDA-ARS?s Scientific Manuscript database

Traditionally, educational materials describing the effects of heat damage within baled hays have focused on reduced bioavailability of crude protein as a result of Maillard reactions. These reactions are not simple, but actually occur in complex, multi-step pathways. Typically, the initial step inv...

Macro-fingerprint analysis-through-separation of licorice based on FT-IR and 2DCOS-IR

NASA Astrophysics Data System (ADS)

Wang, Yang; Wang, Ping; Xu, Changhua; Yang, Yan; Li, Jin; Chen, Tao; Li, Zheng; Cui, Weili; Zhou, Qun; Sun, Suqin; Li, Huifen

2014-07-01

In this paper, a step-by-step analysis-through-separation method under the navigation of multi-step IR macro-fingerprint (FT-IR integrated with second derivative IR (SD-IR) and 2DCOS-IR) was developed for comprehensively characterizing the hierarchical chemical fingerprints of licorice from entirety to single active components. Subsequently, the chemical profile variation rules of three parts (flavonoids, saponins and saccharides) in the separation process were holistically revealed and the number of matching peaks and correlation coefficients with standards of pure compounds was increasing along the extracting directions. The findings were supported by UPLC results and a verification experiment of aqueous separation process. It has been demonstrated that the developed multi-step IR macro-fingerprint analysis-through-separation approach could be a rapid, effective and integrated method not only for objectively providing comprehensive chemical characterization of licorice and all its separated parts, but also for rapidly revealing the global enrichment trend of the active components in licorice separation process.

Self-regenerating column chromatography

DOEpatents

Park, Woo K.

1995-05-30

The present invention provides a process for treating both cations and anions by using a self-regenerating, multi-ionic exchange resin column system which requires no separate regeneration steps. The process involves alternating ion-exchange chromatography for cations and anions in a multi-ionic exchange column packed with a mixture of cation and anion exchange resins. The multi-ionic mixed-charge resin column works as a multi-function column, capable of independently processing either cationic or anionic exchange, or simultaneously processing both cationic and anionic exchanges. The major advantage offered by the alternating multi-function ion exchange process is the self-regeneration of the resins.

Multi-Sided Markets for Transforming Healthcare Service Delivery.

PubMed

Kuziemsky, Craig; Vimarlund, Vivian

2018-01-01

Changes in healthcare delivery needs have necessitated the design of new models for connecting providers and consumers of services. While healthcare delivery has traditionally been a push market, multi-sided markets offer the potential for transitioning to a pull market for service delivery. However, there is a need to better understand the business model for multi-sided markets as a first step to using them in healthcare. This paper addressed that need and describes a multi-sided market evaluation framework. Our framework identifies patient, governance and service delivery as three levels of brokerage consideration for evaluating multi-sided markets in healthcare.

Quasi-multi-pulse voltage source converter design with two control degrees of freedom

NASA Astrophysics Data System (ADS)

Vural, A. M.; Bayindir, K. C.

2015-05-01

In this article, the design details of a quasi-multi-pulse voltage source converter (VSC) switched at line frequency of 50 Hz are given in a step-by-step process. The proposed converter is comprised of four 12-pulse converter units, which is suitable for the simulation of single-/multi-converter flexible alternating current transmission system devices as well as high voltage direct current systems operating at the transmission level. The magnetic interface of the converter is originally designed with given all parameters for 100 MVA operation. The so-called two-angle control method is adopted to control the voltage magnitude and the phase angle of the converter independently. PSCAD simulation results verify both four-quadrant converter operation and closed-loop control of the converter operated as static synchronous compensator (STATCOM).

The General Base in the Thymidylate Synthase Catalyzed Proton Abstraction

PubMed Central

Ghosh, Ananda K.; Islam, Zahidul; Krueger, Jonathan; Abeysinghe, Don Thelma; Kohen, Amnon

2015-01-01

The enzyme thymidylate synthase (TSase), an important chemotherapeutic drug target, catalyzes the formation of 2′-deoxythymidine-5′-monophosphate (dTMP), a precursor of one of the DNA building blocks. TSase catalyzes a multi-step mechanism that includes the abstraction of a proton from the C5 of the substrate 2′-deoxyuridine-5′-monophosphate (dUMP). Previous studies on ecTSase proposed that an active-site residue, Y94 serves the role of the general base abstracting this proton. However, since Y94 is neither very basic, nor connected to basic residues, nor located close enough to the pyrimidine proton to be abstracted, the actual identity of this base remains enigmatic. Based on crystal structures, an alternative hypothesis is that the nearest potential proton-acceptor of C5 of dUMP is a water molecule that is part of a hydrogen bond (H-bond) network comprised of several water molecules and several protein residues including H147, E58, N177, and Y94. Here, we examine the role of the residue Y94 in the proton abstraction step by removing its hydroxyl group (Y94F mutant). We investigated the effect of the mutation on the temperature dependence of intrinsic kinetic isotope effects (KIEs) and found that these KIEs are more temperature dependent than those of the wild-type enzyme (WT). These results suggest that the phenolic –OH of Y94 is a component of the transition state for the proton abstraction step. The findings further support the hypothesis that no single functional group is the general base, but a network of bases and hydroxyls (from water molecules and tyrosine) sharing H-bonds across the active site can serve the role of the general base to remove the pyrimidine proton. PMID:25912171

Simplified Helium Refrigerator Cycle Analysis Using the `Carnot Step'

DOE Office of Scientific and Technical Information (OSTI.GOV)

P. Knudsen; V. Ganni

2006-05-01

An analysis of the Claude form of an idealized helium liquefier for the minimum input work reveals the ''Carnot Step'' for helium refrigerator cycles. As the ''Carnot Step'' for a multi-stage polytropic compression process consists of equal pressure ratio stages; similarly for an idealized helium liquefier the ''Carnot Step'' consists of equal temperature ratio stages for a given number of expansion stages. This paper presents the analytical basis and some useful equations for the preliminary examination of existing and new Claude helium refrigeration cycles.

How Different kinds of Communication and the Mass Media Affect Tourism.

DTIC Science & Technology

1984-12-01

C. Criticism of the Two-Step Flow Model------------------------------ 38 3. The Multi-Step Flow Model or Theory------- 39 4. One-Step Flow Model or... Criticism of the Two-Step Flow Model Researchers have identified deficiencies in the r,,c-w:er :low-model. McNelly, for instance, se,7s mass...evidence of the relative importance of cc munication on the diffusion flow. 38 Rogers ’as criticized ] the theor-y on the grounds that: neither its

Reconstructing targetable pathways in lung cancer by integrating diverse omics data

PubMed Central

Balbin, O. Alejandro; Prensner, John R.; Sahu, Anirban; Yocum, Anastasia; Shankar, Sunita; Malik, Rohit; Fermin, Damian; Dhanasekaran, Saravana M.; Chandler, Benjamin; Thomas, Dafydd; Beer, David G.; Cao, Xuhong; Nesvizhskii, Alexey I.; Chinnaiyan, Arul M.

2014-01-01

Global ‘multi-omics’ profiling of cancer cells harbours the potential for characterizing the signaling networks associated with specific oncogenes. Here we profile the transcriptome, proteome and phosphoproteome in a panel of non-small cell lung cancer (NSCLC) cell lines in order to reconstruct targetable networks associated with KRAS dependency. We develop a two-step bioinformatics strategy addressing the challenge of integrating these disparate data sets. We first define an ‘abundance-score’ combining transcript, protein and phospho-protein abundances to nominate differentially abundant proteins and then use the Prize Collecting Steiner Tree algorithm to identify functional sub-networks. We identify three modules centered on KRAS and MET, LCK and PAK1 and b-Catenin. We validate activation of these proteins in KRAS-dependent (KRAS-Dep) cells and perform functional studies defining LCK as a critical gene for cell proliferation in KRAS-Dep but not KRAS-independent NSCLCs. These results suggest that LCK is a potential druggable target protein in KRAS-Dep lung cancers. PMID:24135919

Step-By-Step Instructions for Retina Recordings with Perforated Multi Electrode Arrays

PubMed Central

Idrees, Saad; Mutter, Marion; Benkner, Boris; Münch, Thomas A.

2014-01-01

Multi-electrode arrays are a state-of-the-art tool in electrophysiology, also in retina research. The output cells of the retina, the retinal ganglion cells, form a monolayer in many species and are well accessible due to their proximity to the inner retinal surface. This structure has allowed the use of multi-electrode arrays for high-throughput, parallel recordings of retinal responses to presented visual stimuli, and has led to significant new insights into retinal organization and function. However, using conventional arrays where electrodes are embedded into a glass or ceramic plate can be associated with three main problems: (1) low signal-to-noise ratio due to poor contact between electrodes and tissue, especially in the case of strongly curved retinas from small animals, e.g. rodents; (2) insufficient oxygen and nutrient supply to cells located on the bottom of the recording chamber; and (3) displacement of the tissue during recordings. Perforated multi-electrode arrays (pMEAs) have been found to alleviate all three issues in brain slice recordings. Over the last years, we have been using such perforated arrays to study light evoked activity in the retinas of various species including mouse, pig, and human. In this article, we provide detailed step-by-step instructions for the use of perforated MEAs to record visual responses from the retina, including spike recordings from retinal ganglion cells and in vitro electroretinograms (ERG). In addition, we provide in-depth technical and methodological troubleshooting information, and show example recordings of good quality as well as examples for the various problems which might be encountered. While our description is based on the specific equipment we use in our own lab, it may also prove useful when establishing retinal MEA recordings with other equipment. PMID:25165854

High-performance liquid chromatography with fluorescence detection for the rapid analysis of pheophytins and pyropheophytins in virgin olive oil.

PubMed

Li, Xueqi; Woodman, Michael; Wang, Selina C

2015-08-01

Pheophytins and pyropheophytin are degradation products of chlorophyll pigments, and their ratios can be used as a sensitive indicator of stress during the manufacturing and storage of olive oil. They increase over time depending on the storage condition and if the oil is exposed to heat treatments during the refining process. The traditional analysis method includes solvent- and time-consuming steps of solid-phase extraction followed by analysis by high-performance liquid chromatography with ultraviolet detection. We developed an improved dilute/fluorescence method where multi-step sample preparation was replaced by a simple isopropanol dilution before the high-performance liquid chromatography injection. A quaternary solvent gradient method was used to include a fourth strong solvent wash on a quaternary gradient pump, which avoided the need to premix any solvents and greatly reduced the oil residues on the column from previous analysis. This new method not only reduces analysis cost and time but shows reliability, repeatability, and improved sensitivity, especially important for low-level samples. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A Multi-step Transcriptional and Chromatin State Cascade Underlies Motor Neuron Programming from Embryonic Stem Cells.

PubMed

Velasco, Silvia; Ibrahim, Mahmoud M; Kakumanu, Akshay; Garipler, Görkem; Aydin, Begüm; Al-Sayegh, Mohamed Ahmed; Hirsekorn, Antje; Abdul-Rahman, Farah; Satija, Rahul; Ohler, Uwe; Mahony, Shaun; Mazzoni, Esteban O

2017-02-02

Direct cell programming via overexpression of transcription factors (TFs) aims to control cell fate with the degree of precision needed for clinical applications. However, the regulatory steps involved in successful terminal cell fate programming remain obscure. We have investigated the underlying mechanisms by looking at gene expression, chromatin states, and TF binding during the uniquely efficient Ngn2, Isl1, and Lhx3 motor neuron programming pathway. Our analysis reveals a highly dynamic process in which Ngn2 and the Isl1/Lhx3 pair initially engage distinct regulatory regions. Subsequently, Isl1/Lhx3 binding shifts from one set of targets to another, controlling regulatory region activity and gene expression as cell differentiation progresses. Binding of Isl1/Lhx3 to later motor neuron enhancers depends on the Ebf and Onecut TFs, which are induced by Ngn2 during the programming process. Thus, motor neuron programming is the product of two initially independent transcriptional modules that converge with a feedforward transcriptional logic. Copyright © 2017 Elsevier Inc. All rights reserved.

Continuous-Time Bilinear System Identification

NASA Technical Reports Server (NTRS)

Juang, Jer-Nan

2003-01-01

The objective of this paper is to describe a new method for identification of a continuous-time multi-input and multi-output bilinear system. The approach is to make judicious use of the linear-model properties of the bilinear system when subjected to a constant input. Two steps are required in the identification process. The first step is to use a set of pulse responses resulting from a constant input of one sample period to identify the state matrix, the output matrix, and the direct transmission matrix. The second step is to use another set of pulse responses with the same constant input over multiple sample periods to identify the input matrix and the coefficient matrices associated with the coupling terms between the state and the inputs. Numerical examples are given to illustrate the concept and the computational algorithm for the identification method.

Novel Intersection Type Recognition for Autonomous Vehicles Using a Multi-Layer Laser Scanner.

PubMed

An, Jhonghyun; Choi, Baehoon; Sim, Kwee-Bo; Kim, Euntai

2016-07-20

There are several types of intersections such as merge-roads, diverge-roads, plus-shape intersections and two types of T-shape junctions in urban roads. When an autonomous vehicle encounters new intersections, it is crucial to recognize the types of intersections for safe navigation. In this paper, a novel intersection type recognition method is proposed for an autonomous vehicle using a multi-layer laser scanner. The proposed method consists of two steps: (1) static local coordinate occupancy grid map (SLOGM) building and (2) intersection classification. In the first step, the SLOGM is built relative to the local coordinate using the dynamic binary Bayes filter. In the second step, the SLOGM is used as an attribute for the classification. The proposed method is applied to a real-world environment and its validity is demonstrated through experimentation.

Novel Intersection Type Recognition for Autonomous Vehicles Using a Multi-Layer Laser Scanner

PubMed Central

An, Jhonghyun; Choi, Baehoon; Sim, Kwee-Bo; Kim, Euntai

2016-01-01

There are several types of intersections such as merge-roads, diverge-roads, plus-shape intersections and two types of T-shape junctions in urban roads. When an autonomous vehicle encounters new intersections, it is crucial to recognize the types of intersections for safe navigation. In this paper, a novel intersection type recognition method is proposed for an autonomous vehicle using a multi-layer laser scanner. The proposed method consists of two steps: (1) static local coordinate occupancy grid map (SLOGM) building and (2) intersection classification. In the first step, the SLOGM is built relative to the local coordinate using the dynamic binary Bayes filter. In the second step, the SLOGM is used as an attribute for the classification. The proposed method is applied to a real-world environment and its validity is demonstrated through experimentation. PMID:27447640

MultiDrizzle: An Integrated Pyraf Script for Registering, Cleaning and Combining Images

NASA Astrophysics Data System (ADS)

Koekemoer, A. M.; Fruchter, A. S.; Hook, R. N.; Hack, W.

We present the new PyRAF-based `MultiDrizzle' script, which is aimed at providing a one-step approach to combining dithered HST images. The purpose of this script is to allow easy interaction with the complex suite of tasks in the IRAF/STSDAS `dither' package, as well as the new `PyDrizzle' task, while at the same time retaining the flexibility of these tasks through a number of parameters. These parameters control the various individual steps, such as sky subtraction, image registration, `drizzling' onto separate output images, creation of a clean median image, transformation of the median with `blot' and creation of cosmic ray masks, as well as the final image combination step using `drizzle'. The default parameters of all the steps are set so that the task will work automatically for a wide variety of different types of images, while at the same time allowing adjustment of individual parameters for special cases. The script currently works for both ACS and WFPC2 data, and is now being tested on STIS and NICMOS images. We describe the operation of the script and the effect of various parameters, particularly in the context of combining images from dithered observations using ACS and WFPC2. Additional information is also available at the `MultiDrizzle' home page: http://www.stsci.edu/~koekemoe/multidrizzle/

Molecular detection assay of five Salmonella serotypes of public interest: Typhimurium, Enteritidis, Newport, Heidelberg, and Hadar.

PubMed

Bugarel, M; Tudor, A; Loneragan, G H; Nightingale, K K

2017-03-01

Foodborne illnesses due to Salmonella represent an important public-health concern worldwide. In the United States, a majority of Salmonella infections are associated with a small number of serotypes. Furthermore, some serotypes that are overrepresented among human disease are also associated with multi-drug resistance phenotypes. Rapid detection of serotypes of public-health concern might help reduce the burden of salmonellosis cases and limit exposure to multi-drug resistant Salmonella. We developed a two-step real-time PCR-based rapid method for the identification and detection of five Salmonella serotypes that are either overrepresented in human disease or frequently associated with multi-drug resistance, including serotypes Enteritidis, Typhimurium, Newport, Hadar, and Heidelberg. Two sets of four markers were developed to detect and differentiate the five serotypes. The first set of markers was developed as a screening step to detect the five serotypes; whereas, the second set was used to further distinguish serotypes Heidelberg, Newport and Hadar. The utilization of these markers on a two-step investigation strategy provides a diagnostic specificity of 97% for the detection of Typhimurium, Enteritidis, Heidelberg, Infantis, Newport and Hadar. The diagnostic sensitivity of the detection makers is >96%. The availability of this two-step rapid method will facilitate specific detection of Salmonella serotypes that contribute to a significant proportion of human disease and carry antimicrobial resistance. Published by Elsevier B.V.

Governance for public health and health equity: The Tröndelag model for public health work.

PubMed

Lillefjell, Monica; Magnus, Eva; Knudtsen, Margunn SkJei; Wist, Guri; Horghagen, Sissel; Espnes, Geir Arild; Maass, Ruca; Anthun, Kirsti Sarheim

2018-06-01

Multi-sectoral governance of population health is linked to the realization that health is the property of many societal systems. This study aims to contribute knowledge and methods that can strengthen the capacities of municipalities regarding how to work more systematically, knowledge-based and multi-sectoral in promoting health and health equity in the population. Process evaluation was conducted, applying a mixed-methods research design, combining qualitative and quantitative data collection methods. Processes strengthening systematic and multi-sectoral development, implementation and evaluation of research-based measures to promote health, quality of life, and health equity in, for and with municipalities were revealed. A step-by-step model, that emphasizes the promotion of knowledge-based, systematic, multi-sectoral public health work, as well as joint ownership of local resources, initiatives and policies has been developed. Implementation of systematic, knowledge-based and multi-sectoral governance of public health measures in municipalities demand shared understanding of the challenges, updated overview of the population health and impact factors, anchoring in plans, new skills and methods for selection and implementation of measures, as well as development of trust, ownership, shared ethics and goals among those involved.

Use of Curricular and Extracurricular Assessments to Predict Performance on the United States Medical Licensing Examination (USMLE) Step 1: A Multi-Year Study

ERIC Educational Resources Information Center

Gandy, Robyn A.; Herial, Nabeel A.; Khuder, Sadik A.; Metting, Patricia J.

2008-01-01

This paper studies student performance predictions based on the United States Medical Licensure Exam (USMLE) Step 1. Subjects were second-year medical students from academic years of 2002 through 2006 (n = 711). Three measures of basic science knowledge (two curricular and one extracurricular) were evaluated as predictors of USMLE Step 1 scores.…

A Multi-touch Tool for Co-creation

NASA Astrophysics Data System (ADS)

Ludden, Geke D. S.; Broens, Tom

Multi-touch technology provides an attractive way for knowledge workers to collaborate. Co-creation is an important collaboration process in which collecting resources, creating results and distributing these results is essential. We propose a wall-based multi-touch system (called CoCreate) in which these steps are made easy due to the notion of connected private spaces and a shared co-create space. We present our ongoing work, expert evaluation of interaction scenarios and future plans.

Central Schemes for Multi-Dimensional Hamilton-Jacobi Equations

NASA Technical Reports Server (NTRS)

Bryson, Steve; Levy, Doron; Biegel, Bryan (Technical Monitor)

2002-01-01

We present new, efficient central schemes for multi-dimensional Hamilton-Jacobi equations. These non-oscillatory, non-staggered schemes are first- and second-order accurate and are designed to scale well with an increasing dimension. Efficiency is obtained by carefully choosing the location of the evolution points and by using a one-dimensional projection step. First-and second-order accuracy is verified for a variety of multi-dimensional, convex and non-convex problems.

Developing a Mind-Body Exercise Programme for Stressed Children

ERIC Educational Resources Information Center

Wang, Claudia; Seo, Dong-Chul; Geib, Roy W

2017-01-01

Objective: To describe the process of developing a Health Qigong programme for stressed children using a formative evaluation approach. Methods: A multi-step formative evaluation method was utilised. These steps included (1) identifying programme content and drafting the curriculum, (2) synthesising effective and age-appropriate pedagogies, (3)…

Steps Toward Innovative Childbirth Education: Selected Strategies From the Blueprint for Action

PubMed Central

Jolivet, R. Rima; Corry, Maureen P.

2010-01-01

To mark the 50th anniversary of Lamaze International, Childbirth Connection celebrates landmark accomplishments in education for childbearing women and families, and takes stock of the changing educational needs and preferences of current childbearing families in looking toward the future. Childbirth Connection's multi-year, multi-stakeholder Transforming Maternity Care initiative resulted in two landmark reports: 2020 Vision for a High-Quality, High-Value Maternity Care System and Blueprint for Action: Steps Toward a High-Quality, High-Value Maternity Care System. Selected recommendations of greatest relevance to the field of childbirth education are discussed, and the new Transforming Maternity Care Partnership is introduced. PMID:21629389

Multi-step splicing of sphingomyelin synthase linear and circular RNAs.

PubMed

Filippenkov, Ivan B; Sudarkina, Olga Yu; Limborska, Svetlana A; Dergunova, Lyudmila V

2018-05-15

The SGMS1 gene encodes the enzyme sphingomyelin synthase 1 (SMS1), which is involved in the regulation of lipid metabolism, apoptosis, intracellular vesicular transport and other significant processes. The SGMS1 gene is located on chromosome 10 and has a size of 320 kb. Previously, we showed that dozens of alternative transcripts of the SGMS1 gene are present in various human tissues. In addition to mRNAs that provide synthesis of the SMS1 protein, this gene participates in the synthesis of non-coding transcripts, including circular RNAs (circRNAs), which include exons of the 5'-untranslated region (5'-UTR) and are highly represented in the brain. In this study, using the high-throughput technology RNA-CaptureSeq, many new SGMS1 transcripts were identified, including both intronic unspliced RNAs (premature RNAs) and RNAs formed via alternative splicing. Recursive exons (RS-exons) that can participate in the multi-step splicing of long introns of the gene were also identified. These exons participate in the formation of circRNAs. Thus, multi-step splicing may provide a variety of linear and circular RNAs of eukaryotic genes in tissues. Copyright © 2018 Elsevier B.V. All rights reserved.

Long-Life and High-Power Binder-Free Cathode Based on One-Step Synthesis of Radical Polymers with Multi-Pendant Groups.

PubMed

Chen, Yaoguang; Zhang, Yangfan; Liu, Xiu; Fan, Xuliang; Bai, Bing; Yang, Kang; Liang, Zhongxin; Zhang, Zishou; Mai, Kancheng

2018-05-16

The main bottlenecks for the widespread application of radical polymers in organic radical batteries are poor cycling stability, due to the dissolution of radical polymers into the electrolyte, and the low efficiency of multi-step synthesis strategies. Herein, a kind of electrolyte-resistant radical polymer bearing multi-pendant groups (poly(ethylene-alt-TEMPO maleate) (PETM)) is designed and synthesized through a one-step esterification reaction to graft 4-hydroxy-2,2,6,6-teramethylpiperidinyl-1-oxy into the commercially available poly(ethylene-alt-maleic anhydride). Interestingly, PETM is hardly soluble in the ethylene carbonate/dimethyl carbonate/ethyl methyl carbonate-based electrolyte, showing an extremely low solubility of 0.59 mg mL -1 , but is easily soluble in tetrahydrofuran and N-Methyl pyrrolidone. The derived binder-free PETM cathode exhibits nearly 100% utilization of the grafted nitroxide radicals (88 mA h g -1 ) and excellent rate capability with almost invariant capacitance from 10 C to 40 C. Significantly, the PETM cathodes retain 94% of the initial capacity after 1000 cycles, outperforming most reported radical polymer-based cathodes. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Influence of multi-step washing using Na2EDTA, oxalic acid and phosphoric acid on metal fractionation and spectroscopy characteristics from contaminated soil.

PubMed

Wei, Meng; Chen, Jiajun

2016-11-01

A multi-step soil washing test using a typical chelating agent (Na 2 EDTA), organic acid (oxalic acid), and inorganic weak acid (phosphoric acid) was conducted to remediate soil contaminated with heavy metals near an arsenic mining area. The aim of the test was to improve the heavy metal removal efficiency and investigate its influence on metal fractionation and the spectroscopy characteristics of contaminated soil. The results indicated that the orders of the multi-step washing were critical for the removal efficiencies of the metal fractions, bioavailability, and potential mobility due to the different dissolution levels of mineral fractions and the inter-transformation of metal fractions by XRD and FT-IR spectral analyses. The optimal soil washing options were identified as the Na 2 EDTA-phosphoric-oxalic acid (EPO) and phosphoric-oxalic acid-Na 2 EDTA (POE) sequences because of their high removal efficiencies (approximately 45 % for arsenic and 88 % for cadmium) and the minimal harmful effects that were determined by the mobility and bioavailability of the remaining heavy metals based on the metal stability (I R ) and modified redistribution index ([Formula: see text]).

Retrieval of Aerosol Absorption Properties from Satellite Observations

NASA Technical Reports Server (NTRS)

Torres, Omar; Bhartia, Pawan K.; Jethva, H.; Ahn, Chang-Woo

2012-01-01

The Angstrom Absorption Exponent (AAE) is a parameter commonly used to characterize the wavelength-dependence of aerosol absorption optical depth (AAOD). It is closely related to aerosol composition. Black carbon (BC) containing aerosols yield AAE values near unity whereas Organic carbon (OC) aerosol particles are associated with values larger than 2. Even larger AAE values have been reported for desert dust aerosol particles. Knowledge of spectral AAOD is necessary for the calculation of direct radiative forcing effect of aerosols and for inferring aerosol composition. We have developed a satellitebased method of determining the spectral AAOD of absorbing aerosols. The technique uses multi-spectral measurements of upwelling radiation from scenes where absorbing aerosols lie above clouds as indicated by the UV Aerosol Index. For those conditions, the satellite measurement can be explained, using an approximations of Beer's Law (BL), as the upwelling reflectance at the cloud top attenuated by the absorption effects of the overlying aerosol layer. The upwelling reflectance at the cloud-top in an aerosol-free atmospheric column is mainly a function of cloud optical depth (COD). In the proposed method of AAE derivation, the first step is determining COD which is retrieved using a previously developed color-ratio based approach. In the second step, corrections for molecular scattering effects are applied to both the observed ad the calculated cloud reflectance terms, and the spectral AAOD is then derived by an inversion of the BL approximation. The proposed technique will be discussed in detail and application results making use of OMI multi-spectral measurements in the UV-Vis. will be presented.

Fully chip-embedded automation of a multi-step lab-on-a-chip process using a modularized timer circuit.

PubMed

Kang, Junsu; Lee, Donghyeon; Heo, Young Jin; Chung, Wan Kyun

2017-11-07

For highly-integrated microfluidic systems, an actuation system is necessary to control the flow; however, the bulk of actuation devices including pumps or valves has impeded the broad application of integrated microfluidic systems. Here, we suggest a microfluidic process control method based on built-in microfluidic circuits. The circuit is composed of a fluidic timer circuit and a pneumatic logic circuit. The fluidic timer circuit is a serial connection of modularized timer units, which sequentially pass high pressure to the pneumatic logic circuit. The pneumatic logic circuit is a NOR gate array designed to control the liquid-controlling process. By using the timer circuit as a built-in signal generator, multi-step processes could be done totally inside the microchip without any external controller. The timer circuit uses only two valves per unit, and the number of process steps can be extended without limitation by adding timer units. As a demonstration, an automation chip has been designed for a six-step droplet treatment, which entails 1) loading, 2) separation, 3) reagent injection, 4) incubation, 5) clearing and 6) unloading. Each process was successfully performed for a pre-defined step-time without any external control device.

Data-based control of a multi-step forming process

NASA Astrophysics Data System (ADS)

Schulte, R.; Frey, P.; Hildenbrand, P.; Vogel, M.; Betz, C.; Lechner, M.; Merklein, M.

2017-09-01

The fourth industrial revolution represents a new stage in the organization and management of the entire value chain. However, concerning the field of forming technology, the fourth industrial revolution has only arrived gradually until now. In order to make a valuable contribution to the digital factory the controlling of a multistage forming process was investigated. Within the framework of the investigation, an abstracted and transferable model is used to outline which data have to be collected, how an interface between the different forming machines can be designed tangible and which control tasks must be fulfilled. The goal of this investigation was to control the subsequent process step based on the data recorded in the first step. The investigated process chain links various metal forming processes, which are typical elements of a multi-step forming process. Data recorded in the first step of the process chain is analyzed and processed for an improved process control of the subsequent process. On the basis of the gained scientific knowledge, it is possible to make forming operations more robust and at the same time more flexible, and thus create the fundament for linking various production processes in an efficient way.

Multi-objective optimization for an automated and simultaneous phase and baseline correction of NMR spectral data

NASA Astrophysics Data System (ADS)

Sawall, Mathias; von Harbou, Erik; Moog, Annekathrin; Behrens, Richard; Schröder, Henning; Simoneau, Joël; Steimers, Ellen; Neymeyr, Klaus

2018-04-01

Spectral data preprocessing is an integral and sometimes inevitable part of chemometric analyses. For Nuclear Magnetic Resonance (NMR) spectra a possible first preprocessing step is a phase correction which is applied to the Fourier transformed free induction decay (FID) signal. This preprocessing step can be followed by a separate baseline correction step. Especially if series of high-resolution spectra are considered, then automated and computationally fast preprocessing routines are desirable. A new method is suggested that applies the phase and the baseline corrections simultaneously in an automated form without manual input, which distinguishes this work from other approaches. The underlying multi-objective optimization or Pareto optimization provides improved results compared to consecutively applied correction steps. The optimization process uses an objective function which applies strong penalty constraints and weaker regularization conditions. The new method includes an approach for the detection of zero baseline regions. The baseline correction uses a modified Whittaker smoother. The functionality of the new method is demonstrated for experimental NMR spectra. The results are verified against gravimetric data. The method is compared to alternative preprocessing tools. Additionally, the simultaneous correction method is compared to a consecutive application of the two correction steps.

SPAR-H Step-by-Step Guidance

DOE Office of Scientific and Technical Information (OSTI.GOV)

W. J. Galyean; A. M. Whaley; D. L. Kelly

This guide provides step-by-step guidance on the use of the SPAR-H method for quantifying Human Failure Events (HFEs). This guide is intended to be used with the worksheets provided in: 'The SPAR-H Human Reliability Analysis Method,' NUREG/CR-6883, dated August 2005. Each step in the process of producing a Human Error Probability (HEP) is discussed. These steps are: Step-1, Categorizing the HFE as Diagnosis and/or Action; Step-2, Rate the Performance Shaping Factors; Step-3, Calculate PSF-Modified HEP; Step-4, Accounting for Dependence, and; Step-5, Minimum Value Cutoff. The discussions on dependence are extensive and include an appendix that describes insights obtained from themore » psychology literature.« less

A liposome-based energy conversion system for accelerating the multi-enzyme reactions.

PubMed

Matsumoto, Ryuhei; Kakuta, Masaya; Sugiyama, Taiki; Goto, Yoshio; Sakai, Hideki; Tokita, Yuichi; Hatazawa, Tsuyonobu; Tsujimura, Seiya; Shirai, Osamu; Kano, Kenji

2010-11-14

We report the first example of a liposome-based energy conversion system that is useful for entrapping enzymes and NAD coenzyme to accelerate multi-step enzymatic reactions. The liposome generates a much higher catalytic current compared with the non-liposome system, which is in good consistency with numerical simulations.

Systematic Approach to Calculate the Concentration of Chemical Species in Multi-Equilibrium Problems

ERIC Educational Resources Information Center

Baeza-Baeza, Juan Jose; Garcia-Alvarez-Coque, Maria Celia

2011-01-01

A general systematic approach is proposed for the numerical calculation of multi-equilibrium problems. The approach involves several steps: (i) the establishment of balances involving the chemical species in solution (e.g., mass balances, charge balance, and stoichiometric balance for the reaction products), (ii) the selection of the unknowns (the…

Measurement Invariance of the "Servant Leadership Questionnaire" across K-12 Principal Gender

ERIC Educational Resources Information Center

Xu, Lihua; Stewart, Trae; Haber-Curran, Paige

2015-01-01

Measurement invariance of the five-factor "Servant Leadership Questionnaire" between female and male K-12 principals was tested using multi-group confirmatory factor analysis. A sample of 956 principals (56.9% were females and 43.1% were males) was analysed in this study. The hierarchical multi-step measurement invariance test supported…

Synthetic Biology for Cell-Free Biosynthesis: Fundamentals of Designing Novel In Vitro Multi-Enzyme Reaction Networks.

PubMed

Morgado, Gaspar; Gerngross, Daniel; Roberts, Tania M; Panke, Sven

Cell-free biosynthesis in the form of in vitro multi-enzyme reaction networks or enzyme cascade reactions emerges as a promising tool to carry out complex catalysis in one-step, one-vessel settings. It combines the advantages of well-established in vitro biocatalysis with the power of multi-step in vivo pathways. Such cascades have been successfully applied to the synthesis of fine and bulk chemicals, monomers and complex polymers of chemical importance, and energy molecules from renewable resources as well as electricity. The scale of these initial attempts remains small, suggesting that more robust control of such systems and more efficient optimization are currently major bottlenecks. To this end, the very nature of enzyme cascade reactions as multi-membered systems requires novel approaches for implementation and optimization, some of which can be obtained from in vivo disciplines (such as pathway refactoring and DNA assembly), and some of which can be built on the unique, cell-free properties of cascade reactions (such as easy analytical access to all system intermediates to facilitate modeling).

The parallel algorithm for the 2D discrete wavelet transform

NASA Astrophysics Data System (ADS)

Barina, David; Najman, Pavel; Kleparnik, Petr; Kula, Michal; Zemcik, Pavel

2018-04-01

The discrete wavelet transform can be found at the heart of many image-processing algorithms. Until now, the transform on general-purpose processors (CPUs) was mostly computed using a separable lifting scheme. As the lifting scheme consists of a small number of operations, it is preferred for processing using single-core CPUs. However, considering a parallel processing using multi-core processors, this scheme is inappropriate due to a large number of steps. On such architectures, the number of steps corresponds to the number of points that represent the exchange of data. Consequently, these points often form a performance bottleneck. Our approach appropriately rearranges calculations inside the transform, and thereby reduces the number of steps. In other words, we propose a new scheme that is friendly to parallel environments. When evaluating on multi-core CPUs, we consistently overcome the original lifting scheme. The evaluation was performed on 61-core Intel Xeon Phi and 8-core Intel Xeon processors.

Very low dose naltrexone addition in opioid detoxification: a randomized, controlled trial.

PubMed

Mannelli, Paolo; Patkar, Ashwin A; Peindl, Kathi; Gorelick, David A; Wu, Li-Tzy; Gottheil, Edward

2009-04-01

Although current treatments for opioid detoxification are not always effective, medical detoxification remains a required step before long-term interventions. The use of opioid antagonist medications to improve detoxification has produced inconsistent results. Very low dose naltrexone (VLNTX) was recently found to reduce opioid tolerance and dependence in animal and clinical studies. We decided to evaluate safety and efficacy of VLNTX adjunct to methadone in reducing withdrawal during detoxification. In a multi-center, double-blind, randomized study at community treatment programs, where most detoxifications are performed, 174 opioid-dependent subjects received NTX 0.125 mg, 0.250 mg or placebo daily for 6 days, together with methadone in tapering doses. VLNTX-treated individuals reported attenuated withdrawal symptoms [F = 7.24 (2,170); P = 0.001] and reduced craving [F = 3.73 (2,107); P = 0.03]. Treatment effects were more pronounced at discharge and were not accompanied by a significantly higher retention rate. There were no group differences in use of adjuvant medications and no treatment-related adverse events. Further studies should explore the use of VLNTX, combined with full and partial opioid agonist medications, in detoxification and long-term treatment of opioid dependence.

Mechanisms of autophagy and relevant small-molecule compounds for targeted cancer therapy.

PubMed

Zhang, Jin; Wang, Guan; Zhou, Yuxin; Chen, Yi; Ouyang, Liang; Liu, Bo

2018-05-01

Autophagy is an evolutionarily conserved, multi-step lysosomal degradation process for the clearance of damaged or superfluous proteins and organelles. Accumulating studies have recently revealed that autophagy is closely related to a variety of types of cancer; however, elucidation of its Janus role of either tumor-suppressive or tumor-promoting still remains to be discovered. In this review, we focus on summarizing the context-dependent role of autophagy and its complicated molecular mechanisms in different types of cancer. Moreover, we discuss a series of small-molecule compounds targeting autophagy-related proteins or the autophagic process for potential cancer therapy. Taken together, these findings would shed new light on exploiting the intricate mechanisms of autophagy and relevant small-molecule compounds as potential anti-cancer drugs to improve targeted cancer therapy.

Centrality and collision system dependence of antiproton production from p+A to Au+Au collisions at AGS energies

NASA Technical Reports Server (NTRS)

Sako, H.; Ahle, L.; Akiba, Y.; Ashktorab, K.; Baker, M. D.; Beavis, D.; Britt, H. C.; Chang, J.; Chasman, C.; Chen, Z.;

Optical Probe of the Density of Defect States in Organic Thin-Film Transistors

NASA Astrophysics Data System (ADS)

Breban, Mihaela; Romero, Danilo; Ballarotto, Vincent; Williams, Ellen

2006-03-01

We investigate the role of defect states associated with different gate dielectric materials on charge transport in organic thin film transistors. Using a modulation technique we measure the magnitude and the phase of the photocurrent^1 in pentacene thin film transistors as a function of the modulation frequency. The photocurrent generation process is modeled as exciton dissociation due to interaction with localized traps. A time domain analyses of this multi-step process allows us to extract the density of defect states. We use this technique to compare the physical mechanism underlying performances of pentacene devices fabricated with different dielectric materials. *Supported by the Laboratory for Physical Science ^1 M. Breban, et al. ``Photocurrent probe of field-dependent mobility in organic thin-film transistors'' Appl. Phys. Letts. 87, 203503 (2005)

Machine Learning Techniques for Global Sensitivity Analysis in Climate Models

NASA Astrophysics Data System (ADS)

Safta, C.; Sargsyan, K.; Ricciuto, D. M.

2017-12-01

Climate models studies are not only challenged by the compute intensive nature of these models but also by the high-dimensionality of the input parameter space. In our previous work with the land model components (Sargsyan et al., 2014) we identified subsets of 10 to 20 parameters relevant for each QoI via Bayesian compressive sensing and variance-based decomposition. Nevertheless the algorithms were challenged by the nonlinear input-output dependencies for some of the relevant QoIs. In this work we will explore a combination of techniques to extract relevant parameters for each QoI and subsequently construct surrogate models with quantified uncertainty necessary to future developments, e.g. model calibration and prediction studies. In the first step, we will compare the skill of machine-learning models (e.g. neural networks, support vector machine) to identify the optimal number of classes in selected QoIs and construct robust multi-class classifiers that will partition the parameter space in regions with smooth input-output dependencies. These classifiers will be coupled with techniques aimed at building sparse and/or low-rank surrogate models tailored to each class. Specifically we will explore and compare sparse learning techniques with low-rank tensor decompositions. These models will be used to identify parameters that are important for each QoI. Surrogate accuracy requirements are higher for subsequent model calibration studies and we will ascertain the performance of this workflow for multi-site ALM simulation ensembles.

Using Sudoku to Introduce Proof Techniques

ERIC Educational Resources Information Center

Snyder, Brian A.

2010-01-01

In this article we show how the Sudoku puzzle and the three simple rules determining its solution can be used as an introduction to proof-based mathematics. In the completion of the puzzle, students can construct multi-step solutions that involve sequencing of steps, use methods such as backtracking and proof by cases, and proof by contradiction…

Implementing the Indiana Model. Indiana Leadership Consortium: Equity through Change.

ERIC Educational Resources Information Center

Indiana Leadership Consortium.

This guide, which was developed as a part of a multi-year, statewide effort to institutionalize gender equity in various educational settings throughout Indiana, presents a step-by-step process model for achieving gender equity in the state's secondary- and postsecondary-level vocational programs through coalition building and implementation of a…

Cross-cultural adaptation of instruments assessing breastfeeding determinants: a multi-step approach

PubMed Central

2014-01-01

Background Cross-cultural adaptation is a necessary process to effectively use existing instruments in other cultural and language settings. The process of cross-culturally adapting, including translation, of existing instruments is considered a critical set to establishing a meaningful instrument for use in another setting. Using a multi-step approach is considered best practice in achieving cultural and semantic equivalence of the adapted version. We aimed to ensure the content validity of our instruments in the cultural context of KwaZulu-Natal, South Africa. Methods The Iowa Infant Feeding Attitudes Scale, Breastfeeding Self-Efficacy Scale-Short Form and additional items comprise our consolidated instrument, which was cross-culturally adapted utilizing a multi-step approach during August 2012. Cross-cultural adaptation was achieved through steps to maintain content validity and attain semantic equivalence in the target version. Specifically, Lynn’s recommendation to apply an item-level content validity index score was followed. The revised instrument was translated and back-translated. To ensure semantic equivalence, Brislin’s back-translation approach was utilized followed by the committee review to address any discrepancies that emerged from translation. Results Our consolidated instrument was adapted to be culturally relevant and translated to yield more reliable and valid results for use in our larger research study to measure infant feeding determinants effectively in our target cultural context. Conclusions Undertaking rigorous steps to effectively ensure cross-cultural adaptation increases our confidence that the conclusions we make based on our self-report instrument(s) will be stronger. In this way, our aim to achieve strong cross-cultural adaptation of our consolidated instruments was achieved while also providing a clear framework for other researchers choosing to utilize existing instruments for work in other cultural, geographic and population settings. PMID:25285151

Multistep cascade annihilations of dark matter and the Galactic Center excess

DOE PAGES

Elor, Gilly; Rodd, Nicholas L.; Slatyer, Tracy R.

2015-05-26

If dark matter is embedded in a non-trivial dark sector, it may annihilate and decay to lighter dark-sector states which subsequently decay to the Standard Model. Such scenarios - with annihilation followed by cascading dark-sector decays - can explain the apparent excess GeV gamma-rays identified in the central Milky Way, while evading bounds from dark matter direct detection experiments. Each 'step' in the cascade will modify the observable signatures of dark matter annihilation and decay, shifting the resulting photons and other final state particles to lower energies and broadening their spectra. We explore, in a model-independent way, the effect ofmore » multi-step dark-sector cascades on the preferred regions of parameter space to explain the GeV excess. We find that the broadening effects of multi-step cascades can admit final states dominated by particles that would usually produce too sharply peaked photon spectra; in general, if the cascades are hierarchical (each particle decays to substantially lighter particles), the preferred mass range for the dark matter is in all cases 20-150 GeV. Decay chains that have nearly-degenerate steps, where the products are close to half the mass of the progenitor, can admit much higher DM masses. We map out the region of mass/cross-section parameter space where cascades (degenerate, hierarchical or a combination) can fit the signal, for a range of final states. In the current paper, we study multi-step cascades in the context of explaining the GeV excess, but many aspects of our results are general and can be extended to other applications.« less

Enhancing multi-step quantum state tomography by PhaseLift

NASA Astrophysics Data System (ADS)

Lu, Yiping; Zhao, Qing

2017-09-01

Multi-photon system has been studied by many groups, however the biggest challenge faced is the number of copies of an unknown state are limited and far from detecting quantum entanglement. The difficulty to prepare copies of the state is even more serious for the quantum state tomography. One possible way to solve this problem is to use adaptive quantum state tomography, which means to get a preliminary density matrix in the first step and revise it in the second step. In order to improve the performance of adaptive quantum state tomography, we develop a new distribution scheme of samples and extend it to three steps, that is to correct it once again based on the density matrix obtained in the traditional adaptive quantum state tomography. Our numerical results show that the mean square error of the reconstructed density matrix by our new method is improved to the level from 10-4 to 10-9 for several tested states. In addition, PhaseLift is also applied to reduce the required storage space of measurement operator.

Vesselness propagation: a fast interactive vessel segmentation method

NASA Astrophysics Data System (ADS)

Cai, Wenli; Dachille, Frank; Harris, Gordon J.; Yoshida, Hiroyuki

2006-03-01

With the rapid development of multi-detector computed tomography (MDCT), resulting in increasing temporal and spatial resolution of data sets, clinical use of computed tomographic angiography (CTA) is rapidly increasing. Analysis of vascular structures is much needed in CTA images; however, the basis of the analysis, vessel segmentation, can still be a challenging problem. In this paper, we present a fast interactive method for CTA vessel segmentation, called vesselness propagation. This method is a two-step procedure, with a pre-processing step and an interactive step. During the pre-processing step, a vesselness volume is computed by application of a CTA transfer function followed by a multi-scale Hessian filtering. At the interactive stage, the propagation is controlled interactively in terms of the priority of the vesselness. This method was used successfully in many CTA applications such as the carotid artery, coronary artery, and peripheral arteries. It takes less than one minute for a user to segment the entire vascular structure. Thus, the proposed method provides an effective way of obtaining an overview of vascular structures.

Mediator directs co-transcriptional heterochromatin assembly by RNA interference-dependent and -independent pathways.

PubMed

Oya, Eriko; Kato, Hiroaki; Chikashige, Yuji; Tsutsumi, Chihiro; Hiraoka, Yasushi; Murakami, Yota

2013-01-01

Heterochromatin at the pericentromeric repeats in fission yeast is assembled and spread by an RNAi-dependent mechanism, which is coupled with the transcription of non-coding RNA from the repeats by RNA polymerase II. In addition, Rrp6, a component of the nuclear exosome, also contributes to heterochromatin assembly and is coupled with non-coding RNA transcription. The multi-subunit complex Mediator, which directs initiation of RNA polymerase II-dependent transcription, has recently been suggested to function after initiation in processes such as elongation of transcription and splicing. However, the role of Mediator in the regulation of chromatin structure is not well understood. We investigated the role of Mediator in pericentromeric heterochromatin formation and found that deletion of specific subunits of the head domain of Mediator compromised heterochromatin structure. The Mediator head domain was required for Rrp6-dependent heterochromatin nucleation at the pericentromere and for RNAi-dependent spreading of heterochromatin into the neighboring region. In the latter process, Mediator appeared to contribute to efficient processing of siRNA from transcribed non-coding RNA, which was required for efficient spreading of heterochromatin. Furthermore, the head domain directed efficient transcription in heterochromatin. These results reveal a pivotal role for Mediator in multiple steps of transcription-coupled formation of pericentromeric heterochromatin. This observation further extends the role of Mediator to co-transcriptional chromatin regulation.

Multi-step high-throughput conjugation platform for the development of antibody-drug conjugates.

PubMed

Andris, Sebastian; Wendeler, Michaela; Wang, Xiangyang; Hubbuch, Jürgen

2018-07-20

Antibody-drug conjugates (ADCs) form a rapidly growing class of biopharmaceuticals which attracts a lot of attention throughout the industry due to its high potential for cancer therapy. They combine the specificity of a monoclonal antibody (mAb) and the cell-killing capacity of highly cytotoxic small molecule drugs. Site-specific conjugation approaches involve a multi-step process for covalent linkage of antibody and drug via a linker. Despite the range of parameters that have to be investigated, high-throughput methods are scarcely used so far in ADC development. In this work an automated high-throughput platform for a site-specific multi-step conjugation process on a liquid-handling station is presented by use of a model conjugation system. A high-throughput solid-phase buffer exchange was successfully incorporated for reagent removal by utilization of a batch cation exchange step. To ensure accurate screening of conjugation parameters, an intermediate UV/Vis-based concentration determination was established including feedback to the process. For conjugate characterization, a high-throughput compatible reversed-phase chromatography method with a runtime of 7 min and no sample preparation was developed. Two case studies illustrate the efficient use for mapping the operating space of a conjugation process. Due to the degree of automation and parallelization, the platform is capable of significantly reducing process development efforts and material demands and shorten development timelines for antibody-drug conjugates. Copyright © 2018 Elsevier B.V. All rights reserved.

Earth As An Unstructured Mesh and Its Recovery from Seismic Waveform Data

NASA Astrophysics Data System (ADS)

De Hoop, M. V.

2015-12-01

We consider multi-scale representations of Earth's interior from thepoint of view of their possible recovery from multi- andhigh-frequency seismic waveform data. These representations areintrinsically connected to (geologic, tectonic) structures, that is,geometric parametrizations of Earth's interior. Indeed, we address theconstruction and recovery of such parametrizations using localiterative methods with appropriately designed data misfits andguaranteed convergence. The geometric parametrizations containinterior boundaries (defining, for example, faults, salt bodies,tectonic blocks, slabs) which can, in principle, be obtained fromsuccessive segmentation. We make use of unstructured meshes. For the adaptation and recovery of an unstructured mesh we introducean energy functional which is derived from the Hausdorff distance. Viaan augmented Lagrangian method, we incorporate the mentioned datamisfit. The recovery is constrained by shape optimization of theinterior boundaries, and is reminiscent of Hausdorff warping. We useelastic deformation via finite elements as a regularization whilefollowing a two-step procedure. The first step is an update determinedby the energy functional; in the second step, we modify the outcome ofthe first step where necessary to ensure that the new mesh isregular. This modification entails an array of techniques includingtopology correction involving interior boundary contacting andbreakup, edge warping and edge removal. We implement this as afeed-back mechanism from volume to interior boundary meshesoptimization. We invoke and apply a criterion of mesh quality controlfor coarsening, and for dynamical local multi-scale refinement. Wepresent a novel (fluid-solid) numerical framework based on theDiscontinuous Galerkin method.

Numerical simulation of machining distortions on a forged aerospace component following a one and a multi-step approaches

NASA Astrophysics Data System (ADS)

Prete, Antonio Del; Franchi, Rodolfo; Antermite, Fabrizio; Donatiello, Iolanda

2018-05-01

Residual stresses appear in a component as a consequence of thermo-mechanical processes (e.g. ring rolling process) casting and heat treatments. When machining these kinds of components, distortions arise due to the redistribution of residual stresses due to the foregoing process history inside the material. If distortions are excessive, they can lead to a large number of scrap parts. Since dimensional accuracy can affect directly the engines efficiency, the dimensional control for aerospace components is a non-trivial issue. In this paper, the problem related to the distortions of large thin walled aeroengines components in nickel superalloys has been addressed. In order to estimate distortions on inner diameters after internal turning operations, a 3D Finite Element Method (FEM) analysis has been developed on a real industrial test case. All the process history, has been taken into account by developing FEM models of ring rolling process and heat treatments. Three different strategies of ring rolling process have been studied and the combination of related parameters which allows to obtain the best dimensional accuracy has been found. Furthermore, grain size evolution and recrystallization phenomena during manufacturing process has been numerically investigated using a semi empirical Johnson-Mehl-Avrami-Kohnogorov (JMAK) model. The volume subtractions have been simulated by boolean trimming: a one step and a multi step analysis have been performed. The multi-step procedure has allowed to choose the best material removal sequence in order to reduce machining distortions.

Physical activity promotion in the primary care setting in pre- and type 2 diabetes - the Sophia step study, an RCT.

PubMed

Rossen, Jenny; Yngve, Agneta; Hagströmer, Maria; Brismar, Kerstin; Ainsworth, Barbara E; Iskull, Christina; Möller, Peter; Johansson, Unn-Britt

2015-07-12

Physical activity prevents or delays progression of impaired glucose tolerance in high-risk individuals. Physical activity promotion should serve as a basis in diabetes care. It is necessary to develop and evaluate health-promoting methods that are feasible as well as cost-effective within diabetes care. The aim of Sophia Step Study is to evaluate the impact of a multi-component and a single component physical activity intervention aiming at improving HbA1c (primary outcome) and other metabolic and cardiovascular risk factors, physical activity levels and overall health in patients with pre- and type 2 diabetes. Sophia Step Study is a randomized controlled trial and participants are randomly assigned to either a multi-component intervention group (A), a pedometer group (B) or a control group (C). In total, 310 patients will be included and followed for 24 months. Group A participants are offered pedometers and a website to register steps, physical activity on prescription with yearly follow-ups, motivational interviewing (10 occasions) and group consultations (including walks, 12 occasions). Group B participants are offered pedometers and a website to register steps. Group C are offered usual care. The theoretical framework underpinning the interventions is the Health Belief Model, the Stages of Change Model, and the Social Cognitive Theory. Both the multi-component intervention (group A) and the pedometer intervention (group B) are using several techniques for behavior change such as self-monitoring, goal setting, feedback and relapse prevention. Measurements are made at week 0, 8, 12, 16, month 6, 9, 12, 18 and 24, including metabolic and cardiovascular biomarkers (HbA1c as primary health outcome), accelerometry and daily steps. Furthermore, questionnaires were used to evaluate dietary intake, physical activity, perceived ability to perform physical activity, perceived support for being active, quality of life, anxiety, depression, well-being, perceived treatment, perceived stress and diabetes self- efficacy. This study will show if a multi-component intervention using pedometers with group- and individual consultations is more effective than a single- component intervention using pedometers alone, in increasing physical activity and improving HbA1c, other metabolic and cardiovascular risk factors, physical activity levels and overall health in patients with pre- and type 2 diabetes. ClinicalTrials.gov Identifier: NCT02374788 . Registered 28 January 2015.

Communication: An efficient approach to compute state-specific nuclear gradients for a generic state-averaged multi-configuration self consistent field wavefunction.

PubMed

Granovsky, Alexander A

2015-12-21

We present a new, very efficient semi-numerical approach for the computation of state-specific nuclear gradients of a generic state-averaged multi-configuration self consistent field wavefunction. Our approach eliminates the costly coupled-perturbed multi-configuration Hartree-Fock step as well as the associated integral transformation stage. The details of the implementation within the Firefly quantum chemistry package are discussed and several sample applications are given. The new approach is routinely applicable to geometry optimization of molecular systems with 1000+ basis functions using a standalone multi-core workstation.

Communication: An efficient approach to compute state-specific nuclear gradients for a generic state-averaged multi-configuration self consistent field wavefunction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Granovsky, Alexander A., E-mail: alex.granovsky@gmail.com

We present a new, very efficient semi-numerical approach for the computation of state-specific nuclear gradients of a generic state-averaged multi-configuration self consistent field wavefunction. Our approach eliminates the costly coupled-perturbed multi-configuration Hartree-Fock step as well as the associated integral transformation stage. The details of the implementation within the Firefly quantum chemistry package are discussed and several sample applications are given. The new approach is routinely applicable to geometry optimization of molecular systems with 1000+ basis functions using a standalone multi-core workstation.

Kinematic Validation of a Multi-Kinect v2 Instrumented 10-Meter Walkway for Quantitative Gait Assessments.

PubMed

Geerse, Daphne J; Coolen, Bert H; Roerdink, Melvyn

2015-01-01

Walking ability is frequently assessed with the 10-meter walking test (10MWT), which may be instrumented with multiple Kinect v2 sensors to complement the typical stopwatch-based time to walk 10 meters with quantitative gait information derived from Kinect's 3D body point's time series. The current study aimed to evaluate a multi-Kinect v2 set-up for quantitative gait assessments during the 10MWT against a gold-standard motion-registration system by determining between-systems agreement for body point's time series, spatiotemporal gait parameters and the time to walk 10 meters. To this end, the 10MWT was conducted at comfortable and maximum walking speed, while 3D full-body kinematics was concurrently recorded with the multi-Kinect v2 set-up and the Optotrak motion-registration system (i.e., the gold standard). Between-systems agreement for body point's time series was assessed with the intraclass correlation coefficient (ICC). Between-systems agreement was similarly determined for the gait parameters' walking speed, cadence, step length, stride length, step width, step time, stride time (all obtained for the intermediate 6 meters) and the time to walk 10 meters, complemented by Bland-Altman's bias and limits of agreement. Body point's time series agreed well between the motion-registration systems, particularly so for body points in motion. For both comfortable and maximum walking speeds, the between-systems agreement for the time to walk 10 meters and all gait parameters except step width was high (ICC ≥ 0.888), with negligible biases and narrow limits of agreement. Hence, body point's time series and gait parameters obtained with a multi-Kinect v2 set-up match well with those derived with a gold standard in 3D measurement accuracy. Future studies are recommended to test the clinical utility of the multi-Kinect v2 set-up to automate 10MWT assessments, thereby complementing the time to walk 10 meters with reliable spatiotemporal gait parameters obtained objectively in a quick, unobtrusive and patient-friendly manner.

Kinematic Validation of a Multi-Kinect v2 Instrumented 10-Meter Walkway for Quantitative Gait Assessments

PubMed Central

Geerse, Daphne J.; Coolen, Bert H.; Roerdink, Melvyn

2015-01-01

Walking ability is frequently assessed with the 10-meter walking test (10MWT), which may be instrumented with multiple Kinect v2 sensors to complement the typical stopwatch-based time to walk 10 meters with quantitative gait information derived from Kinect’s 3D body point’s time series. The current study aimed to evaluate a multi-Kinect v2 set-up for quantitative gait assessments during the 10MWT against a gold-standard motion-registration system by determining between-systems agreement for body point’s time series, spatiotemporal gait parameters and the time to walk 10 meters. To this end, the 10MWT was conducted at comfortable and maximum walking speed, while 3D full-body kinematics was concurrently recorded with the multi-Kinect v2 set-up and the Optotrak motion-registration system (i.e., the gold standard). Between-systems agreement for body point’s time series was assessed with the intraclass correlation coefficient (ICC). Between-systems agreement was similarly determined for the gait parameters’ walking speed, cadence, step length, stride length, step width, step time, stride time (all obtained for the intermediate 6 meters) and the time to walk 10 meters, complemented by Bland-Altman’s bias and limits of agreement. Body point’s time series agreed well between the motion-registration systems, particularly so for body points in motion. For both comfortable and maximum walking speeds, the between-systems agreement for the time to walk 10 meters and all gait parameters except step width was high (ICC ≥ 0.888), with negligible biases and narrow limits of agreement. Hence, body point’s time series and gait parameters obtained with a multi-Kinect v2 set-up match well with those derived with a gold standard in 3D measurement accuracy. Future studies are recommended to test the clinical utility of the multi-Kinect v2 set-up to automate 10MWT assessments, thereby complementing the time to walk 10 meters with reliable spatiotemporal gait parameters obtained objectively in a quick, unobtrusive and patient-friendly manner. PMID:26461498

The dependency structure of coordinate phrases: a corpus approach.

PubMed

Temperley, David

2005-11-01

Hudson (1990) proposes that each conjunct in a coordinate phrase forms dependency relations with heads or dependents outside the coordinate phrase (the "multi-head" view). This proposal is tested through corpus analysis of Wall Street Journal text. For right-branching constituents (such as direct-object NPs), a short-long preference for conjunct ordering is observed; this is predicted by the multi-head view, under the assumption that structures resulting in shorter dependencies are preferred. A short-long preference is also observed for left-branching constituents (such as subject NPs), which is less obviously accommodated by the multi-head view but not incompatible with it. The repetition of determiners was also examined (the dog and cat versus the dog and the cat), and a stronger preference was found for repetition with singular count nouns as opposed to mass or plural nouns; this accords well with the multi-head view, under the reasoning that single-determiner constructions require crossing dependencies with count nouns but not with plural or mass nouns.

A Dimensionality Reduction-Based Multi-Step Clustering Method for Robust Vessel Trajectory Analysis

PubMed Central

Liu, Jingxian; Wu, Kefeng

2017-01-01

The Shipboard Automatic Identification System (AIS) is crucial for navigation safety and maritime surveillance, data mining and pattern analysis of AIS information have attracted considerable attention in terms of both basic research and practical applications. Clustering of spatio-temporal AIS trajectories can be used to identify abnormal patterns and mine customary route data for transportation safety. Thus, the capacities of navigation safety and maritime traffic monitoring could be enhanced correspondingly. However, trajectory clustering is often sensitive to undesirable outliers and is essentially more complex compared with traditional point clustering. To overcome this limitation, a multi-step trajectory clustering method is proposed in this paper for robust AIS trajectory clustering. In particular, the Dynamic Time Warping (DTW), a similarity measurement method, is introduced in the first step to measure the distances between different trajectories. The calculated distances, inversely proportional to the similarities, constitute a distance matrix in the second step. Furthermore, as a widely-used dimensional reduction method, Principal Component Analysis (PCA) is exploited to decompose the obtained distance matrix. In particular, the top k principal components with above 95% accumulative contribution rate are extracted by PCA, and the number of the centers k is chosen. The k centers are found by the improved center automatically selection algorithm. In the last step, the improved center clustering algorithm with k clusters is implemented on the distance matrix to achieve the final AIS trajectory clustering results. In order to improve the accuracy of the proposed multi-step clustering algorithm, an automatic algorithm for choosing the k clusters is developed according to the similarity distance. Numerous experiments on realistic AIS trajectory datasets in the bridge area waterway and Mississippi River have been implemented to compare our proposed method with traditional spectral clustering and fast affinity propagation clustering. Experimental results have illustrated its superior performance in terms of quantitative and qualitative evaluations. PMID:28777353

Iterative reconstruction methods in atmospheric tomography: FEWHA, Kaczmarz and Gradient-based algorithm

NASA Astrophysics Data System (ADS)

Ramlau, R.; Saxenhuber, D.; Yudytskiy, M.

2014-07-01

The problem of atmospheric tomography arises in ground-based telescope imaging with adaptive optics (AO), where one aims to compensate in real-time for the rapidly changing optical distortions in the atmosphere. Many of these systems depend on a sufficient reconstruction of the turbulence profiles in order to obtain a good correction. Due to steadily growing telescope sizes, there is a strong increase in the computational load for atmospheric reconstruction with current methods, first and foremost the MVM. In this paper we present and compare three novel iterative reconstruction methods. The first iterative approach is the Finite Element- Wavelet Hybrid Algorithm (FEWHA), which combines wavelet-based techniques and conjugate gradient schemes to efficiently and accurately tackle the problem of atmospheric reconstruction. The method is extremely fast, highly flexible and yields superior quality. Another novel iterative reconstruction algorithm is the three step approach which decouples the problem in the reconstruction of the incoming wavefronts, the reconstruction of the turbulent layers (atmospheric tomography) and the computation of the best mirror correction (fitting step). For the atmospheric tomography problem within the three step approach, the Kaczmarz algorithm and the Gradient-based method have been developed. We present a detailed comparison of our reconstructors both in terms of quality and speed performance in the context of a Multi-Object Adaptive Optics (MOAO) system for the E-ELT setting on OCTOPUS, the ESO end-to-end simulation tool.

Video Processes in Teacher Education Programs; Scope, Techniques, and Assessment. Multi-State Teacher Education Project, Monograph III.

ERIC Educational Resources Information Center

Bosley, Howard E.; And Others

"Video Processes Are Changing Teacher Education" by Howard Bosley (the first of five papers comprising this document) discusses the Multi-State Teacher Education Project (M-STEP) experimentation with media; it lists various uses of video processes, concentrating specifically on microteaching and the use of simulation and critical…

3-D Wave-Structure Interaction with Coastal Sediments - A Multi-Physics/Multi-Solution Techniques Approach

DTIC Science & Technology

2007-01-01

Stokes (RANS) and the particle finite element method ( PFEM ) will be used in the water/mine/sand domain. Sand and the geomaterials around the sand will...wave propagation over a bottom mine at various time steps (Soil and Foam model) 8 SOLID/FEM SAND/SPH GEOMATERIALS FNPF/BEM FNPF/BEM RANS/ PFEM

Effect of Turbulent Fluctuations on Infrared Radiation from a Tactical Missile Plume

DTIC Science & Technology

1982-02-01

Reacting Flows ...... 21 Reacting Flow Calculations ..................................... 21 Turbulence- Chemistry Interaction...a two-equation, turbulence kinetic energy model. The code is capable of handling multi-species, multi-step chemistry . However, it does not calculate...that are expected to be important in turbulence- chemistry and turbulence-radiation interactions. The program calculates only two turbulence guantities

[Research progress of multi-model medical image fusion and recognition].

PubMed

Zhou, Tao; Lu, Huiling; Chen, Zhiqiang; Ma, Jingxian

2013-10-01

Medical image fusion and recognition has a wide range of applications, such as focal location, cancer staging and treatment effect assessment. Multi-model medical image fusion and recognition are analyzed and summarized in this paper. Firstly, the question of multi-model medical image fusion and recognition is discussed, and its advantage and key steps are discussed. Secondly, three fusion strategies are reviewed from the point of algorithm, and four fusion recognition structures are discussed. Thirdly, difficulties, challenges and possible future research direction are discussed.

12-step affiliation and attendance following treatment for comorbid substance dependence and depression: a latent growth curve mediation model.

PubMed

Worley, Matthew J; Tate, Susan R; McQuaid, John R; Granholm, Eric L; Brown, Sandra A

2013-01-01

Among substance-dependent individuals, comorbid major depressive disorder (MDD) is associated with greater severity and poorer treatment outcomes, but little research has examined mediators of posttreatment substance use outcomes within this population. Using latent growth curve models, the authors tested relationships between individual rates of change in 12-step involvement and substance use, utilizing posttreatment follow-up data from a trial of group Twelve-Step Facilitation (TSF) and integrated cognitive-behavioral therapy (ICBT) for veterans with substance dependence and MDD. Although TSF patients were higher on 12-step affiliation and meeting attendance at end-of-treatment as compared with ICBT, they also experienced significantly greater reductions in these variables during the year following treatment, ending at similar levels as ICBT. Veterans in TSF also had significantly greater increases in drinking frequency during follow-up, and this group difference was mediated by their greater reductions in 12-step affiliation and meeting attendance. Patients with comorbid depression appear to have difficulty sustaining high levels of 12-step involvement after the conclusion of formal 12-step interventions, which predicts poorer drinking outcomes over time. Modifications to TSF and other formal 12-step protocols or continued therapeutic contact may be necessary to sustain 12-step involvement and reduced drinking for patients with substance dependence and MDD.

The performance of a reduced-order adaptive controller when used in multi-antenna hyperthermia treatments with nonlinear temperature-dependent perfusion.

PubMed

Cheng, Kung-Shan; Yuan, Yu; Li, Zhen; Stauffer, Paul R; Maccarini, Paolo; Joines, William T; Dewhirst, Mark W; Das, Shiva K

2009-04-07

In large multi-antenna systems, adaptive controllers can aid in steering the heat focus toward the tumor. However, the large number of sources can greatly increase the steering time. Additionally, controller performance can be degraded due to changes in tissue perfusion which vary non-linearly with temperature, as well as with time and spatial position. The current work investigates whether a reduced-order controller with the assumption of piecewise constant perfusion is robust to temperature-dependent perfusion and achieves steering in a shorter time than required by a full-order controller. The reduced-order controller assumes that the optimal heating setting lies in a subspace spanned by the best heating vectors (virtual sources) of an initial, approximate, patient model. An initial, approximate, reduced-order model is iteratively updated by the controller, using feedback thermal images, until convergence of the heat focus to the tumor. Numerical tests were conducted in a patient model with a right lower leg sarcoma, heated in a 10-antenna cylindrical mini-annual phased array applicator operating at 150 MHz. A half-Gaussian model was used to simulate temperature-dependent perfusion. Simulated magnetic resonance temperature images were used as feedback at each iteration step. Robustness was validated for the controller, starting from four approximate initial models: (1) a 'standard' constant perfusion lower leg model ('standard' implies a model that exactly models the patient with the exception that perfusion is considered constant, i.e., not temperature dependent), (2) a model with electrical and thermal tissue properties varied from 50% higher to 50% lower than the standard model, (3) a simplified constant perfusion pure-muscle lower leg model with +/-50% deviated properties and (4) a standard model with the tumor position in the leg shifted by 1.5 cm. Convergence to the desired focus of heating in the tumor was achieved for all four simulated models. The controller accomplished satisfactory therapeutic outcomes: approximately 80% of the tumor was heated to temperatures 43 degrees C and approximately 93% was maintained at temperatures <41 degrees C. Compared to the controller without model reduction, a approximately 9-25 fold reduction in convergence time was accomplished using approximately 2-3 orthonormal virtual sources. In the situations tested, the controller was robust to the presence of temperature-dependent perfusion. The results of this work can help to lay the foundation for real-time thermal control of multi-antenna hyperthermia systems in clinical situations where perfusion can change rapidly with temperature.

Is There a Critical Distance for Fickian Transport? - a Statistical Approach to Sub-Fickian Transport Modelling in Porous Media

NASA Astrophysics Data System (ADS)

Most, S.; Nowak, W.; Bijeljic, B.

2014-12-01

Transport processes in porous media are frequently simulated as particle movement. This process can be formulated as a stochastic process of particle position increments. At the pore scale, the geometry and micro-heterogeneities prohibit the commonly made assumption of independent and normally distributed increments to represent dispersion. Many recent particle methods seek to loosen this assumption. Recent experimental data suggest that we have not yet reached the end of the need to generalize, because particle increments show statistical dependency beyond linear correlation and over many time steps. The goal of this work is to better understand the validity regions of commonly made assumptions. We are investigating after what transport distances can we observe: A statistical dependence between increments, that can be modelled as an order-k Markov process, boils down to order 1. This would be the Markovian distance for the process, where the validity of yet-unexplored non-Gaussian-but-Markovian random walks would start. A bivariate statistical dependence that simplifies to a multi-Gaussian dependence based on simple linear correlation (validity of correlated PTRW). Complete absence of statistical dependence (validity of classical PTRW/CTRW). The approach is to derive a statistical model for pore-scale transport from a powerful experimental data set via copula analysis. The model is formulated as a non-Gaussian, mutually dependent Markov process of higher order, which allows us to investigate the validity ranges of simpler models.

Dependability and Treatment Sensitivity of Multi-Item Direct Behavior Rating Scales for Interpersonal Peer Conflict

ERIC Educational Resources Information Center

Daniels, Brian; Volpe, Robert J.; Briesch, Amy M.; Gadow, Kenneth D.

2017-01-01

Direct behavior rating (DBR) represents a feasible method for monitoring student behavior in the classroom; however, limited work to date has focused on the use of multi-item scales. The purposes of the study were to examine the (a) dependability of data obtained from a multi-item DBR designed to assess peer conflict and (b) treatment sensitivity…

Transient Calibration of a Variably-Saturated Groundwater Flow Model By Iterative Ensemble Smoothering: Synthetic Case and Application to the Flow Induced During Shaft Excavation and Operation of the Bure Underground Research Laboratory

NASA Astrophysics Data System (ADS)

Lam, D. T.; Kerrou, J.; Benabderrahmane, H.; Perrochet, P.

2017-12-01

The calibration of groundwater flow models in transient state can be motivated by the expected improved characterization of the aquifer hydraulic properties, especially when supported by a rich transient dataset. In the prospect of setting up a calibration strategy for a variably-saturated transient groundwater flow model of the area around the ANDRA's Bure Underground Research Laboratory, we wish to take advantage of the long hydraulic head and flowrate time series collected near and at the access shafts in order to help inform the model hydraulic parameters. A promising inverse approach for such high-dimensional nonlinear model, and which applicability has been illustrated more extensively in other scientific fields, could be an iterative ensemble smoother algorithm initially developed for a reservoir engineering problem. Furthermore, the ensemble-based stochastic framework will allow to address to some extent the uncertainty of the calibration for a subsequent analysis of a flow process dependent prediction. By assimilating the available data in one single step, this method iteratively updates each member of an initial ensemble of stochastic realizations of parameters until the minimization of an objective function. However, as it is well known for ensemble-based Kalman methods, this correction computed from approximations of covariance matrices is most efficient when the ensemble realizations are multi-Gaussian. As shown by the comparison of the updated ensemble mean obtained for our simplified synthetic model of 2D vertical flow by using either multi-Gaussian or multipoint simulations of parameters, the ensemble smoother fails to preserve the initial connectivity of the facies and the parameter bimodal distribution. Given the geological structures depicted by the multi-layered geological model built for the real case, our goal is to find how to still best leverage the performance of the ensemble smoother while using an initial ensemble of conditional multi-Gaussian simulations or multipoint simulations as conceptually consistent as possible. Performance of the algorithm including additional steps to help mitigate the effects of non-Gaussian patterns, such as Gaussian anamorphosis, or resampling of facies from the training image using updated local probability constraints will be assessed.

Modeling human faces with multi-image photogrammetry

NASA Astrophysics Data System (ADS)

D'Apuzzo, Nicola

2002-03-01

Modeling and measurement of the human face have been increasing by importance for various purposes. Laser scanning, coded light range digitizers, image-based approaches and digital stereo photogrammetry are the used methods currently employed in medical applications, computer animation, video surveillance, teleconferencing and virtual reality to produce three dimensional computer models of the human face. Depending on the application, different are the requirements. Ours are primarily high accuracy of the measurement and automation in the process. The method presented in this paper is based on multi-image photogrammetry. The equipment, the method and results achieved with this technique are here depicted. The process is composed of five steps: acquisition of multi-images, calibration of the system, establishment of corresponding points in the images, computation of their 3-D coordinates and generation of a surface model. The images captured by five CCD cameras arranged in front of the subject are digitized by a frame grabber. The complete system is calibrated using a reference object with coded target points, which can be measured fully automatically. To facilitate the establishment of correspondences in the images, texture in the form of random patterns can be projected from two directions onto the face. The multi-image matching process, based on a geometrical constrained least squares matching algorithm, produces a dense set of corresponding points in the five images. Neighborhood filters are then applied on the matching results to remove the errors. After filtering the data, the three-dimensional coordinates of the matched points are computed by forward intersection using the results of the calibration process; the achieved mean accuracy is about 0.2 mm in the sagittal direction and about 0.1 mm in the lateral direction. The last step of data processing is the generation of a surface model from the point cloud and the application of smooth filters. Moreover, a color texture image can be draped over the model to achieve a photorealistic visualization. The advantage of the presented method over laser scanning and coded light range digitizers is the acquisition of the source data in a fraction of a second, allowing the measurement of human faces with higher accuracy and the possibility to measure dynamic events like the speech of a person.

Indoor Multi-Sensor Acquisition System for Projects on Energy Renovation of Buildings.

PubMed

Armesto, Julia; Sánchez-Villanueva, Claudio; Patiño-Cambeiro, Faustino; Patiño-Barbeito, Faustino

2016-05-28

Energy rehabilitation actions in buildings have become a great economic opportunity for the construction sector. They also constitute a strategic goal in the European Union (EU), given the energy dependence and the compromises with climate change of its member states. About 75% of existing buildings in the EU were built when energy efficiency codes had not been developed. Approximately 75% to 90% of those standing buildings are expected to remain in use in 2050. Significant advances have been achieved in energy analysis, simulation tools, and computer fluid dynamics for building energy evaluation. However, the gap between predictions and real savings might still be improved. Geomatics and computer science disciplines can really help in modelling, inspection, and diagnosis procedures. This paper presents a multi-sensor acquisition system capable of automatically and simultaneously capturing the three-dimensional geometric information, thermographic, optical, and panoramic images, ambient temperature map, relative humidity map, and light level map. The system integrates a navigation system based on a Simultaneous Localization and Mapping (SLAM) approach that allows georeferencing every data to its position in the building. The described equipment optimizes the energy inspection and diagnosis steps and facilitates the energy modelling of the building.

Generalized fourier analyses of the advection-diffusion equation - Part II: two-dimensional domains

NASA Astrophysics Data System (ADS)

Voth, Thomas E.; Martinez, Mario J.; Christon, Mark A.

2004-07-01

Part I of this work presents a detailed multi-methods comparison of the spatial errors associated with the one-dimensional finite difference, finite element and finite volume semi-discretizations of the scalar advection-diffusion equation. In Part II we extend the analysis to two-dimensional domains and also consider the effects of wave propagation direction and grid aspect ratio on the phase speed, and the discrete and artificial diffusivities. The observed dependence of dispersive and diffusive behaviour on propagation direction makes comparison of methods more difficult relative to the one-dimensional results. For this reason, integrated (over propagation direction and wave number) error and anisotropy metrics are introduced to facilitate comparison among the various methods. With respect to these metrics, the consistent mass Galerkin and consistent mass control-volume finite element methods, and their streamline upwind derivatives, exhibit comparable accuracy, and generally out-perform their lumped mass counterparts and finite-difference based schemes. While this work can only be considered a first step in a comprehensive multi-methods analysis and comparison, it serves to identify some of the relative strengths and weaknesses of multiple numerical methods in a common mathematical framework. Published in 2004 by John Wiley & Sons, Ltd.

Separation of non-stationary multi-source sound field based on the interpolated time-domain equivalent source method

NASA Astrophysics Data System (ADS)

Bi, Chuan-Xing; Geng, Lin; Zhang, Xiao-Zheng

2016-05-01

In the sound field with multiple non-stationary sources, the measured pressure is the sum of the pressures generated by all sources, and thus cannot be used directly for studying the vibration and sound radiation characteristics of every source alone. This paper proposes a separation model based on the interpolated time-domain equivalent source method (ITDESM) to separate the pressure field belonging to every source from the non-stationary multi-source sound field. In the proposed method, ITDESM is first extended to establish the relationship between the mixed time-dependent pressure and all the equivalent sources distributed on every source with known location and geometry information, and all the equivalent source strengths at each time step are solved by an iterative solving process; then, the corresponding equivalent source strengths of one interested source are used to calculate the pressure field generated by that source alone. Numerical simulation of two baffled circular pistons demonstrates that the proposed method can be effective in separating the non-stationary pressure generated by every source alone in both time and space domains. An experiment with two speakers in a semi-anechoic chamber further evidences the effectiveness of the proposed method.

Indoor Multi-Sensor Acquisition System for Projects on Energy Renovation of Buildings

PubMed Central

Armesto, Julia; Sánchez-Villanueva, Claudio; Patiño-Cambeiro, Faustino; Patiño-Barbeito, Faustino

2016-01-01

Energy rehabilitation actions in buildings have become a great economic opportunity for the construction sector. They also constitute a strategic goal in the European Union (EU), given the energy dependence and the compromises with climate change of its member states. About 75% of existing buildings in the EU were built when energy efficiency codes had not been developed. Approximately 75% to 90% of those standing buildings are expected to remain in use in 2050. Significant advances have been achieved in energy analysis, simulation tools, and computer fluid dynamics for building energy evaluation. However, the gap between predictions and real savings might still be improved. Geomatics and computer science disciplines can really help in modelling, inspection, and diagnosis procedures. This paper presents a multi-sensor acquisition system capable of automatically and simultaneously capturing the three-dimensional geometric information, thermographic, optical, and panoramic images, ambient temperature map, relative humidity map, and light level map. The system integrates a navigation system based on a Simultaneous Localization and Mapping (SLAM) approach that allows georeferencing every data to its position in the building. The described equipment optimizes the energy inspection and diagnosis steps and facilitates the energy modelling of the building. PMID:27240379

Characterisation of temperature dependent parameters of multi-quantum well (MQW) Ti/Au/n-AlGaAs/n-GaAs/n-AlGaAs Schottky diodes

NASA Astrophysics Data System (ADS)

Filali, Walid; Sengouga, Nouredine; Oussalah, Slimane; Mari, Riaz H.; Jameel, Dler; Al Saqri, Noor Alhuda; Aziz, Mohsin; Taylor, David; Henini, Mohamed

2017-11-01

Forward and reverse current-voltage (Isbnd V) of Ti/Au/n-Al0.33Ga0.67As/n-GaAs/n-Al0.33Ga0.67As multi-quantum well (MQW) Schottky diodes were measured over a range of temperatures from 20 to 400 K by a step of 20 K. The Schottky diodes parameters were then extracted from these characteristics. The Cheung method is used for this purpose, assuming a thermionic conduction mechanism. The extracted ideality factor decrease with increasing temperatures. But their values at low temperatures were found to be unrealistic. In order to explain this uncertainty, three assumptions were explored. Firstly an assumed inhomogeneous barrier height gave better parameters especially the Richardson constant but the ideality factor is still unrealistic at low temperatures. Secondly, by using numerical simulation, it was demonstrated that defects including interface states are not responsible for the apparent unrealistic Schottky diode parameters. The third assumption is the tunnelling mechanism through the barrier in the low temperature range. At these lower temperatures, the tunnelling mechanism was more suitable to explain the extracted parameters values.

Biomimetic surface structuring using cylindrical vector femtosecond laser beams

NASA Astrophysics Data System (ADS)

Skoulas, Evangelos; Manousaki, Alexandra; Fotakis, Costas; Stratakis, Emmanuel

2017-03-01

We report on a new, single-step and scalable method to fabricate highly ordered, multi-directional and complex surface structures that mimic the unique morphological features of certain species found in nature. Biomimetic surface structuring was realized by exploiting the unique and versatile angular profile and the electric field symmetry of cylindrical vector (CV) femtosecond (fs) laser beams. It is shown that, highly controllable, periodic structures exhibiting sizes at nano-, micro- and dual- micro/nano scales can be directly written on Ni upon line and large area scanning with radial and azimuthal polarization beams. Depending on the irradiation conditions, new complex multi-directional nanostructures, inspired by the Shark’s skin morphology, as well as superhydrophobic dual-scale structures mimicking the Lotus’ leaf water repellent properties can be attained. It is concluded that the versatility and features variations of structures formed is by far superior to those obtained via laser processing with linearly polarized beams. More important, by exploiting the capabilities offered by fs CV fields, the present technique can be further extended to fabricate even more complex and unconventional structures. We believe that our approach provides a new concept in laser materials processing, which can be further exploited for expanding the breadth and novelty of applications.

Measurement needs guided by synthetic radar scans in high-resolution model output

NASA Astrophysics Data System (ADS)

Varble, A.; Nesbitt, S. W.; Borque, P.

2017-12-01

Microphysical and dynamical process interactions within deep convective clouds are not well understood, partly because measurement strategies often focus on statistics of cloud state rather than cloud processes. While processes cannot be directly measured, they can be inferred with sufficiently frequent and detailed scanning radar measurements focused on the life cycleof individual cloud regions. This is a primary goal of the 2018-19 DOE ARM Cloud, Aerosol, and Complex Terrain Interactions (CACTI) and NSF Remote sensing of Electrification, Lightning, And Mesoscale/microscale Processes with Adaptive Ground Observations (RELAMPAGO) field campaigns in central Argentina, where orographic deep convective initiation is frequent with some high-impact systems growing into the tallest and largest in the world. An array of fixed and mobile scanning multi-wavelength dual-polarization radars will be coupled with surface observations, sounding systems, multi-wavelength vertical profilers, and aircraft in situ measurements to characterize convective cloud life cycles and their relationship with environmental conditions. While detailed cloud processes are an observational target, the radar scan patterns that are most ideal for observing them are unclear. They depend on the locations and scales of key microphysical and dynamical processes operating within the cloud. High-resolution simulations of clouds, while imperfect, can provide information on these locations and scales that guide radar measurement needs. Radar locations are set in the model domain based on planned experiment locations, and simulatedorographic deep convective initiation and upscale growth are sampled using a number of different scans involving RHIs or PPIs with predefined elevation and azimuthal angles that approximately conform with radar range and beam width specifications. Each full scan pattern is applied to output atsingle model time steps with time step intervals that depend on the length of time required to complete each scan in the real world. The ability of different scans to detect key processes within the convective cloud life cycle are examined in connection with previous and subsequent dynamical and microphysical transitions. This work will guide strategic scan patterns that will be used during CACTI and RELAMPAGO.

Rapid discrimination of sea buckthorn berries from different H. rhamnoides subspecies by multi-step IR spectroscopy coupled with multivariate data analysis

NASA Astrophysics Data System (ADS)

Liu, Yue; Zhang, Ying; Zhang, Jing; Fan, Gang; Tu, Ya; Sun, Suqin; Shen, Xudong; Li, Qingzhu; Zhang, Yi

2018-03-01

As an important ethnic medicine, sea buckthorn was widely used to prevent and treat various diseases due to its nutritional and medicinal properties. According to the Chinese Pharmacopoeia, sea buckthorn was originated from H. rhamnoides, which includes five subspecies distributed in China. Confusion and misidentification usually occurred due to their similar morphology, especially in dried and powdered forms. Additionally, these five subspecies have vital differences in quality and physiological efficacy. This paper focused on the quick classification and identification method of sea buckthorn berry powders from five H. rhamnoides subspecies using multi-step IR spectroscopy coupled with multivariate data analysis. The holistic chemical compositions revealed by the FT-IR spectra demonstrated that flavonoids, fatty acids and sugars were the main chemical components. Further, the differences in FT-IR spectra regarding their peaks, positions and intensities were used to identify H. rhamnoides subspecies samples. The discrimination was achieved using principal component analysis (PCA) and partial least square-discriminant analysis (PLS-DA). The results showed that the combination of multi-step IR spectroscopy and chemometric analysis offered a simple, fast and reliable method for the classification and identification of the sea buckthorn berry powders from different H. rhamnoides subspecies.

Unconditionally energy stable time stepping scheme for Cahn–Morral equation: Application to multi-component spinodal decomposition and optimal space tiling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tavakoli, Rouhollah, E-mail: rtavakoli@sharif.ir

An unconditionally energy stable time stepping scheme is introduced to solve Cahn–Morral-like equations in the present study. It is constructed based on the combination of David Eyre's time stepping scheme and Schur complement approach. Although the presented method is general and independent of the choice of homogeneous free energy density function term, logarithmic and polynomial energy functions are specifically considered in this paper. The method is applied to study the spinodal decomposition in multi-component systems and optimal space tiling problems. A penalization strategy is developed, in the case of later problem, to avoid trivial solutions. Extensive numerical experiments demonstrate themore » success and performance of the presented method. According to the numerical results, the method is convergent and energy stable, independent of the choice of time stepsize. Its MATLAB implementation is included in the appendix for the numerical evaluation of algorithm and reproduction of the presented results. -- Highlights: •Extension of Eyre's convex–concave splitting scheme to multiphase systems. •Efficient solution of spinodal decomposition in multi-component systems. •Efficient solution of least perimeter periodic space partitioning problem. •Developing a penalization strategy to avoid trivial solutions. •Presentation of MATLAB implementation of the introduced algorithm.« less

The Effect of a Multi-Strategy Workplace Physical Activity Intervention Promoting Pedometer Use and Step Count Increase

ERIC Educational Resources Information Center

De Cocker, Katrien A.; De Bourdeaudhuij, Ilse M.; Cardon, Greet M.

2010-01-01

Pedometer use and step count goals have become popular in physical activity (PA) interventions in different settings. Previous pedometer-based workplace interventions were short term, uncontrolled and executed outside Europe. This European quasi-experimental study evaluated the effects of a 20-week pedometer-based PA workplace intervention.…

Multi-Dimensional Education: A Common Sense Approach to Data-Driven Thinking

ERIC Educational Resources Information Center

Corrigan, Michael W.; Grove, Doug; Vincent, Philip F.

2011-01-01

Schools aren't one dimensional. Your decision making shouldn't be either. If you want to look beyond student test scores to identify the specific areas that need improvement in your school, you will find practical tools for assessing multiple areas with confidence here. The authors detail a step-by-step framework for identifying, collecting,…

The Synthesis of 2-acetyl-1,4-naphthoquinone: A Multi-step Synthesis.

ERIC Educational Resources Information Center

Green, Ivan R.

1982-01-01

Outlines 2 procedures for synthesizing 2-acetyl-1,4-naphthoquinone to compare relative merits of the two pathways. The major objective of the exercise is to demonstrate that certain factors should be considered when selecting a pathway for synthesis including availability of starting materials, cost of reagents, number of steps involved,…

Comparison of Methods for Demonstrating Passage of Time When Using Computer-Based Video Prompting

ERIC Educational Resources Information Center

Mechling, Linda C.; Bryant, Kathryn J.; Spencer, Galen P.; Ayres, Kevin M.

2015-01-01

Two different video-based procedures for presenting the passage of time (how long a step lasts) were examined. The two procedures were presented within the framework of video prompting to promote independent multi-step task completion across four young adults with moderate intellectual disability. The two procedures demonstrating passage of the…

Automatic Road Gap Detection Using Fuzzy Inference System

NASA Astrophysics Data System (ADS)

Hashemi, S.; Valadan Zoej, M. J.; Mokhtarzadeh, M.

2011-09-01

Automatic feature extraction from aerial and satellite images is a high-level data processing which is still one of the most important research topics of the field. In this area, most of the researches are focused on the early step of road detection, where road tracking methods, morphological analysis, dynamic programming and snakes, multi-scale and multi-resolution methods, stereoscopic and multi-temporal analysis, hyper spectral experiments, are some of the mature methods in this field. Although most researches are focused on detection algorithms, none of them can extract road network perfectly. On the other hand, post processing algorithms accentuated on the refining of road detection results, are not developed as well. In this article, the main is to design an intelligent method to detect and compensate road gaps remained on the early result of road detection algorithms. The proposed algorithm consists of five main steps as follow: 1) Short gap coverage: In this step, a multi-scale morphological is designed that covers short gaps in a hierarchical scheme. 2) Long gap detection: In this step, the long gaps, could not be covered in the previous stage, are detected using a fuzzy inference system. for this reason, a knowledge base consisting of some expert rules are designed which are fired on some gap candidates of the road detection results. 3) Long gap coverage: In this stage, detected long gaps are compensated by two strategies of linear and polynomials for this reason, shorter gaps are filled by line fitting while longer ones are compensated by polynomials.4) Accuracy assessment: In order to evaluate the obtained results, some accuracy assessment criteria are proposed. These criteria are obtained by comparing the obtained results with truly compensated ones produced by a human expert. The complete evaluation of the obtained results whit their technical discussions are the materials of the full paper.

Event-triggered logical flow control for comprehensive process integration of multi-step assays on centrifugal microfluidic platforms.

PubMed

Kinahan, David J; Kearney, Sinéad M; Dimov, Nikolay; Glynn, Macdara T; Ducrée, Jens

2014-07-07

The centrifugal "lab-on-a-disc" concept has proven to have great potential for process integration of bioanalytical assays, in particular where ease-of-use, ruggedness, portability, fast turn-around time and cost efficiency are of paramount importance. Yet, as all liquids residing on the disc are exposed to the same centrifugal field, an inherent challenge of these systems remains the automation of multi-step, multi-liquid sample processing and subsequent detection. In order to orchestrate the underlying bioanalytical protocols, an ample palette of rotationally and externally actuated valving schemes has been developed. While excelling with the level of flow control, externally actuated valves require interaction with peripheral instrumentation, thus compromising the conceptual simplicity of the centrifugal platform. In turn, for rotationally controlled schemes, such as common capillary burst valves, typical manufacturing tolerances tend to limit the number of consecutive laboratory unit operations (LUOs) that can be automated on a single disc. In this paper, a major advancement on recently established dissolvable film (DF) valving is presented; for the very first time, a liquid handling sequence can be controlled in response to completion of preceding liquid transfer event, i.e. completely independent of external stimulus or changes in speed of disc rotation. The basic, event-triggered valve configuration is further adapted to leverage conditional, large-scale process integration. First, we demonstrate a fluidic network on a disc encompassing 10 discrete valving steps including logical relationships such as an AND-conditional as well as serial and parallel flow control. Then we present a disc which is capable of implementing common laboratory unit operations such as metering and selective routing of flows. Finally, as a pilot study, these functions are integrated on a single disc to automate a common, multi-step lab protocol for the extraction of total RNA from mammalian cell homogenate.

Cost-effectiveness Analysis in R Using a Multi-state Modeling Survival Analysis Framework: A Tutorial.

PubMed

Williams, Claire; Lewsey, James D; Briggs, Andrew H; Mackay, Daniel F

2017-05-01

This tutorial provides a step-by-step guide to performing cost-effectiveness analysis using a multi-state modeling approach. Alongside the tutorial, we provide easy-to-use functions in the statistics package R. We argue that this multi-state modeling approach using a package such as R has advantages over approaches where models are built in a spreadsheet package. In particular, using a syntax-based approach means there is a written record of what was done and the calculations are transparent. Reproducing the analysis is straightforward as the syntax just needs to be run again. The approach can be thought of as an alternative way to build a Markov decision-analytic model, which also has the option to use a state-arrival extended approach. In the state-arrival extended multi-state model, a covariate that represents patients' history is included, allowing the Markov property to be tested. We illustrate the building of multi-state survival models, making predictions from the models and assessing fits. We then proceed to perform a cost-effectiveness analysis, including deterministic and probabilistic sensitivity analyses. Finally, we show how to create 2 common methods of visualizing the results-namely, cost-effectiveness planes and cost-effectiveness acceptability curves. The analysis is implemented entirely within R. It is based on adaptions to functions in the existing R package mstate to accommodate parametric multi-state modeling that facilitates extrapolation of survival curves.

CorRECTreatment: A Web-based Decision Support Tool for Rectal Cancer Treatment that Uses the Analytic Hierarchy Process and Decision Tree

PubMed Central

Karakülah, G.; Dicle, O.; Sökmen, S.; Çelikoğlu, C.C.

2015-01-01

Summary Background The selection of appropriate rectal cancer treatment is a complex multi-criteria decision making process, in which clinical decision support systems might be used to assist and enrich physicians’ decision making. Objective The objective of the study was to develop a web-based clinical decision support tool for physicians in the selection of potentially beneficial treatment options for patients with rectal cancer. Methods The updated decision model contained 8 and 10 criteria in the first and second steps respectively. The decision support model, developed in our previous study by combining the Analytic Hierarchy Process (AHP) method which determines the priority of criteria and decision tree that formed using these priorities, was updated and applied to 388 patients data collected retrospectively. Later, a web-based decision support tool named corRECTreatment was developed. The compatibility of the treatment recommendations by the expert opinion and the decision support tool was examined for its consistency. Two surgeons were requested to recommend a treatment and an overall survival value for the treatment among 20 different cases that we selected and turned into a scenario among the most common and rare treatment options in the patient data set. Results In the AHP analyses of the criteria, it was found that the matrices, generated for both decision steps, were consistent (consistency ratio<0.1). Depending on the decisions of experts, the consistency value for the most frequent cases was found to be 80% for the first decision step and 100% for the second decision step. Similarly, for rare cases consistency was 50% for the first decision step and 80% for the second decision step. Conclusions The decision model and corRECTreatment, developed by applying these on real patient data, are expected to provide potential users with decision support in rectal cancer treatment processes and facilitate them in making projections about treatment options. PMID:25848413

CorRECTreatment: a web-based decision support tool for rectal cancer treatment that uses the analytic hierarchy process and decision tree.

PubMed

Suner, A; Karakülah, G; Dicle, O; Sökmen, S; Çelikoğlu, C C

2015-01-01

The selection of appropriate rectal cancer treatment is a complex multi-criteria decision making process, in which clinical decision support systems might be used to assist and enrich physicians' decision making. The objective of the study was to develop a web-based clinical decision support tool for physicians in the selection of potentially beneficial treatment options for patients with rectal cancer. The updated decision model contained 8 and 10 criteria in the first and second steps respectively. The decision support model, developed in our previous study by combining the Analytic Hierarchy Process (AHP) method which determines the priority of criteria and decision tree that formed using these priorities, was updated and applied to 388 patients data collected retrospectively. Later, a web-based decision support tool named corRECTreatment was developed. The compatibility of the treatment recommendations by the expert opinion and the decision support tool was examined for its consistency. Two surgeons were requested to recommend a treatment and an overall survival value for the treatment among 20 different cases that we selected and turned into a scenario among the most common and rare treatment options in the patient data set. In the AHP analyses of the criteria, it was found that the matrices, generated for both decision steps, were consistent (consistency ratio<0.1). Depending on the decisions of experts, the consistency value for the most frequent cases was found to be 80% for the first decision step and 100% for the second decision step. Similarly, for rare cases consistency was 50% for the first decision step and 80% for the second decision step. The decision model and corRECTreatment, developed by applying these on real patient data, are expected to provide potential users with decision support in rectal cancer treatment processes and facilitate them in making projections about treatment options.

[Optimum design of imaging spectrometer based on toroidal uniform-line-spaced (TULS) spectrometer].

PubMed

Xue, Qing-Sheng; Wang, Shu-Rong

2013-05-01

Based on the geometrical aberration theory, a optimum-design method for designing an imaging spectrometer based on toroidal uniform grating spectrometer is proposed. To obtain the best optical parameters, twice optimization is carried out using genetic algorithm(GA) and optical design software ZEMAX A far-ultraviolet(FUV) imaging spectrometer is designed using this method. The working waveband is 110-180 nm, the slit size is 50 microm x 5 mm, and the numerical aperture is 0.1. Using ZEMAX software, the design result is analyzed and evaluated. The results indicate that the MTF for different wavelengths is higher than 0.7 at Nyquist frequency 10 lp x mm(-1), and the RMS spot radius is less than 14 microm. The good imaging quality is achieved over the whole working waveband, the design requirements of spatial resolution 0.5 mrad and spectral resolution 0.6 nm are satisfied. It is certificated that the optimum-design method proposed in this paper is feasible. This method can be applied in other waveband, and is an instruction method for designing grating-dispersion imaging spectrometers.

76 FR 75539 - Intent To Prepare an Environmental Impact Statement for the Central Everglades Planning Project...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-02

... the Federal government, in partnership with the State of Florida, to embark upon a multi-decade, multi... Spreader Canal Western Project. All of these CERP projects utilize lands that were acquired by the State... flows to the interior of the system will not cause adverse effects. The next step for implementation of...

Capacity planning for electronic waste management facilities under uncertainty: multi-objective multi-time-step model development.

PubMed

Poonam Khanijo Ahluwalia; Nema, Arvind K

2011-07-01

Selection of optimum locations for locating new facilities and decision regarding capacities at the proposed facilities is a major concern for municipal authorities/managers. The decision as to whether a single facility is preferred over multiple facilities of smaller capacities would vary with varying priorities to cost and associated risks such as environmental or health risk or risk perceived by the society. Currently management of waste streams such as that of computer waste is being done using rudimentary practices and is flourishing as an unorganized sector, mainly as backyard workshops in many cities of developing nations such as India. Uncertainty in the quantification of computer waste generation is another major concern due to the informal setup of present computer waste management scenario. Hence, there is a need to simultaneously address uncertainty in waste generation quantities while analyzing the tradeoffs between cost and associated risks. The present study aimed to address the above-mentioned issues in a multi-time-step, multi-objective decision-support model, which can address multiple objectives of cost, environmental risk, socially perceived risk and health risk, while selecting the optimum configuration of existing and proposed facilities (location and capacities).

CXTFIT/Excel A modular adaptable code for parameter estimation, sensitivity analysis and uncertainty analysis for laboratory or field tracer experiments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tang, Guoping; Mayes, Melanie; Parker, Jack C

2010-01-01

We implemented the widely used CXTFIT code in Excel to provide flexibility and added sensitivity and uncertainty analysis functions to improve transport parameter estimation and to facilitate model discrimination for multi-tracer experiments on structured soils. Analytical solutions for one-dimensional equilibrium and nonequilibrium convection dispersion equations were coded as VBA functions so that they could be used as ordinary math functions in Excel for forward predictions. Macros with user-friendly interfaces were developed for optimization, sensitivity analysis, uncertainty analysis, error propagation, response surface calculation, and Monte Carlo analysis. As a result, any parameter with transformations (e.g., dimensionless, log-transformed, species-dependent reactions, etc.) couldmore » be estimated with uncertainty and sensitivity quantification for multiple tracer data at multiple locations and times. Prior information and observation errors could be incorporated into the weighted nonlinear least squares method with a penalty function. Users are able to change selected parameter values and view the results via embedded graphics, resulting in a flexible tool applicable to modeling transport processes and to teaching students about parameter estimation. The code was verified by comparing to a number of benchmarks with CXTFIT 2.0. It was applied to improve parameter estimation for four typical tracer experiment data sets in the literature using multi-model evaluation and comparison. Additional examples were included to illustrate the flexibilities and advantages of CXTFIT/Excel. The VBA macros were designed for general purpose and could be used for any parameter estimation/model calibration when the forward solution is implemented in Excel. A step-by-step tutorial, example Excel files and the code are provided as supplemental material.« less

a Global Registration Algorithm of the Single-Closed Ring Multi-Stations Point Cloud

NASA Astrophysics Data System (ADS)

Yang, R.; Pan, L.; Xiang, Z.; Zeng, H.

2018-04-01

Aimed at the global registration problem of the single-closed ring multi-stations point cloud, a formula in order to calculate the error of rotation matrix was constructed according to the definition of error. The global registration algorithm of multi-station point cloud was derived to minimize the error of rotation matrix. And fast-computing formulas of transformation matrix with whose implementation steps and simulation experiment scheme was given. Compared three different processing schemes of multi-station point cloud, the experimental results showed that the effectiveness of the new global registration method was verified, and it could effectively complete the global registration of point cloud.

Multi-Level Sequential Pattern Mining Based on Prime Encoding

NASA Astrophysics Data System (ADS)

Lianglei, Sun; Yun, Li; Jiang, Yin

Encoding is not only to express the hierarchical relationship, but also to facilitate the identification of the relationship between different levels, which will directly affect the efficiency of the algorithm in the area of mining the multi-level sequential pattern. In this paper, we prove that one step of division operation can decide the parent-child relationship between different levels by using prime encoding and present PMSM algorithm and CROSS-PMSM algorithm which are based on prime encoding for mining multi-level sequential pattern and cross-level sequential pattern respectively. Experimental results show that the algorithm can effectively extract multi-level and cross-level sequential pattern from the sequence database.

One-step synthesis of NaLu80-xGdxF4:Yb183+/Er23+(Tm3+) upconversion nanoparticles for in vitro cell imaging.

PubMed

Gerelkhuu, Zayakhuu; Huy, Bui The; Sharipov, Mirkomil; Jung, Dasom; Phan, The-Long; Conte, Eric D; Lee, Yong-Ill

2018-05-01

Upconversion nanoparticles (UCNPs) possess a unique type of photoluminescence (PL) in which lower-energy excitation is converted into higher-energy emission via multi-photon absorption processes. In this work, we have used a facile one-step hydrothermal method promoted water solubility to synthesis NaLuGdF 4 :Yb 3+ /Er 3+ (Tm 3+ ) UCNPs coated with malonic acid (MA). Scanning electron microscopy images and X-ray diffraction patterns reveal sphere-shaped UCNPs with an average size of ~80nm crystallized in the cubic NaLuF 4 structure. The characteristic vibrations of cubic UCNPs have been taken into account by using Fourier-transform infrared spectroscopy. Based on PL studies, we have determined an optimal concentration of Gd 3+ doping. The dependence of upconversion PL intensity on Gd 3+ concentration is discussed via the results of magnetization measurements, which is related to the coupling/uncoupling of Gd 3+ ions. Particularly, our study reveals that carboxyl-functionalized NaLuGdF 4 :Yb 3+ /Er 3+ (Tm 3+ ) UCNPs have a relatively high cell viability with HeLa cells. Copyright © 2017 Elsevier B.V. All rights reserved.

A quantum dynamics study of the benzopyran ring opening guided by laser pulses

NASA Astrophysics Data System (ADS)

Saab, Mohamad; Doriol, Loïc Joubert; Lasorne, Benjamin; Guérin, Stéphane; Gatti, Fabien

2014-10-01

The ring-opening photoisomerization of benzopyran, which occurs via a photochemical route involving a conical intersection, has been studied with quantum dynamics calculations using the multi-configuration time-dependent Hartree method (MCTDH). We introduce a mechanistic strategy to control the conversion of benzopyran to merocyanine with laser pulses. We use a six-dimensional model developed in a previous work for the potential energy surfaces (PES) based on an extension of the vibronic-coupling Hamiltonian model (diabatization method by ansatz), which depends on the most active degrees of freedom. The main objective of these quantum dynamics simulations is to provide a set of strategies that could help experimentalists to control the photoreactivity vs. photostability ratio (selectivity). In this work we present: (i) a pump-dump technique used to control the photostability, (ii) a two-step strategy to enhance the reactivity of the system: first, a pure vibrational excitation in the electronic ground state that prepares the system and, second, an ultraviolet excitation that brings the system to the first adiabatic electronic state; (iii) finally the effect of a non-resonant pulse (Stark effect) on the dynamics.

Further developments in cloud statistics for computer simulations

NASA Technical Reports Server (NTRS)

Chang, D. T.; Willand, J. H.

1972-01-01

This study is a part of NASA's continued program to provide global statistics of cloud parameters for computer simulation. The primary emphasis was on the development of the data bank of the global statistical distributions of cloud types and cloud layers and their applications in the simulation of the vertical distributions of in-cloud parameters such as liquid water content. These statistics were compiled from actual surface observations as recorded in Standard WBAN forms. Data for a total of 19 stations were obtained and reduced. These stations were selected to be representative of the 19 primary cloud climatological regions defined in previous studies of cloud statistics. Using the data compiled in this study, a limited study was conducted of the hemogeneity of cloud regions, the latitudinal dependence of cloud-type distributions, the dependence of these statistics on sample size, and other factors in the statistics which are of significance to the problem of simulation. The application of the statistics in cloud simulation was investigated. In particular, the inclusion of the new statistics in an expanded multi-step Monte Carlo simulation scheme is suggested and briefly outlined.

MESOSCALE MODELING OF DEFLAGRATION-INDUCED DECONSOLIDATION IN POLYMER-BONDED EXPLOSIVES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Springer, H K; Glascoe, E A; Reaugh, J E

Initially undamaged polymer-bonded explosives can transition from conductive burning to more violent convective burning via rapid deconsolidation at higher pressures. The pressure-dependent infiltration of cracks and pores, i.e., damage, by product gases at the burn-front is a key step in the transition to convective burning. However, the relative influence of pre-existing damage and the evolution of deflagration-induced damage during the transition to convective burning is not well understood. The objective of this study is to investigate the role of microstructure and initial pressurization on deconsolidation. We performed simulations using the multi-physics hydrocode, ALE3D. HMX-Viton A served as our model explosive.more » A Prout-Tompkins chemical kinetic model, Vielle's Law pressure-dependent burning, Gruneisen equation-of-state, and simplified strength model were used for the HMX. The propensity for deconsolidation increased with increasing defect size and decreasing initial pressurization, as measured by the increase in burning surface area. These studies are important because they enable the development of continuum-scale damage models and the design of inherently safer explosives.« less

A multi-criteria assessment of scenarios on thermal processing of infectious hospital wastes: A case study for Central Macedonia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Karagiannidis, A.; Papageorgiou, A., E-mail: apapa@auth.g; Perkoulidis, G.

In Greece more than 14,000 tonnes of infectious hospital waste are produced yearly; a significant part of it is still mismanaged. Only one off-site licensed incineration facility for hospital wastes is in operation, with the remaining of the market covered by various hydroclave and autoclave units, whereas numerous problems are still generally encountered regarding waste segregation, collection, transportation and management, as well as often excessive entailed costs. Everyday practices still include dumping the majority of solid hospital waste into household disposal sites and landfills after sterilization, still largely without any preceding recycling and separation steps. Discussed in the present papermore » are the implemented and future treatment practices of infectious hospital wastes in Central Macedonia; produced quantities are reviewed, actual treatment costs are addressed critically, whereas the overall situation in Greece is discussed. Moreover, thermal treatment processes that could be applied for the treatment of infectious hospital wastes in the region are assessed via the multi-criteria decision method Analytic Hierarchy Process. Furthermore, a sensitivity analysis was performed and the analysis demonstrated that a centralized autoclave or hydroclave plant near Thessaloniki is the best performing option, depending however on the selection and weighing of criteria of the multi-criteria process. Moreover the study found that a common treatment option for the treatment of all infectious hospital wastes produced in the Region of Central Macedonia, could offer cost and environmental benefits. In general the multi-criteria decision method, as well as the conclusions and remarks of this study can be used as a basis for future planning and anticipation of the needs for investments in the area of medical waste management.« less

Finite Macro-Element Mesh Deformation in a Structured Multi-Block Navier-Stokes Code

NASA Technical Reports Server (NTRS)

Bartels, Robert E.

2005-01-01

A mesh deformation scheme is developed for a structured multi-block Navier-Stokes code consisting of two steps. The first step is a finite element solution of either user defined or automatically generated macro-elements. Macro-elements are hexagonal finite elements created from a subset of points from the full mesh. When assembled, the finite element system spans the complete flow domain. Macro-element moduli vary according to the distance to the nearest surface, resulting in extremely stiff elements near a moving surface and very pliable elements away from boundaries. Solution of the finite element system for the imposed boundary deflections generally produces smoothly varying nodal deflections. The manner in which distance to the nearest surface has been found to critically influence the quality of the element deformation. The second step is a transfinite interpolation which distributes the macro-element nodal deflections to the remaining fluid mesh points. The scheme is demonstrated for several two-dimensional applications.

Pre-eruptive magmatic processes re-timed using a non-isothermal approach to magma chamber dynamics.

PubMed

Petrone, Chiara Maria; Bugatti, Giuseppe; Braschi, Eleonora; Tommasini, Simone

2016-10-05

Constraining the timescales of pre-eruptive magmatic processes in active volcanic systems is paramount to understand magma chamber dynamics and the triggers for volcanic eruptions. Temporal information of magmatic processes is locked within the chemical zoning profiles of crystals but can be accessed by means of elemental diffusion chronometry. Mineral compositional zoning testifies to the occurrence of substantial temperature differences within magma chambers, which often bias the estimated timescales in the case of multi-stage zoned minerals. Here we propose a new Non-Isothermal Diffusion Incremental Step model to take into account the non-isothermal nature of pre-eruptive processes, deconstructing the main core-rim diffusion profiles of multi-zoned crystals into different isothermal steps. The Non-Isothermal Diffusion Incremental Step model represents a significant improvement in the reconstruction of crystal lifetime histories. Unravelling stepwise timescales at contrasting temperatures provides a novel approach to constraining pre-eruptive magmatic processes and greatly increases our understanding of magma chamber dynamics.

Pre-eruptive magmatic processes re-timed using a non-isothermal approach to magma chamber dynamics

PubMed Central

Petrone, Chiara Maria; Bugatti, Giuseppe; Braschi, Eleonora; Tommasini, Simone

2016-01-01

Constraining the timescales of pre-eruptive magmatic processes in active volcanic systems is paramount to understand magma chamber dynamics and the triggers for volcanic eruptions. Temporal information of magmatic processes is locked within the chemical zoning profiles of crystals but can be accessed by means of elemental diffusion chronometry. Mineral compositional zoning testifies to the occurrence of substantial temperature differences within magma chambers, which often bias the estimated timescales in the case of multi-stage zoned minerals. Here we propose a new Non-Isothermal Diffusion Incremental Step model to take into account the non-isothermal nature of pre-eruptive processes, deconstructing the main core-rim diffusion profiles of multi-zoned crystals into different isothermal steps. The Non-Isothermal Diffusion Incremental Step model represents a significant improvement in the reconstruction of crystal lifetime histories. Unravelling stepwise timescales at contrasting temperatures provides a novel approach to constraining pre-eruptive magmatic processes and greatly increases our understanding of magma chamber dynamics. PMID:27703141

Method for network analyzation and apparatus

DOEpatents

Bracht, Roger B.; Pasquale, Regina V.

2001-01-01

A portable network analyzer and method having multiple channel transmit and receive capability for real-time monitoring of processes which maintains phase integrity, requires low power, is adapted to provide full vector analysis, provides output frequencies of up to 62.5 MHz and provides fine sensitivity frequency resolution. The present invention includes a multi-channel means for transmitting and a multi-channel means for receiving, both in electrical communication with a software means for controlling. The means for controlling is programmed to provide a signal to a system under investigation which steps consecutively over a range of predetermined frequencies. The resulting received signal from the system provides complete time domain response information by executing a frequency transform of the magnitude and phase information acquired at each frequency step.

A volume-of-fluid method for simulation of compressible axisymmetric multi-material flow

NASA Astrophysics Data System (ADS)

de Niem, D.; Kührt, E.; Motschmann, U.

2007-02-01

A two-dimensional Eulerian hydrodynamic method for the numerical simulation of inviscid compressible axisymmetric multi-material flow in external force fields for the situation of pure fluids separated by macroscopic interfaces is presented. The method combines an implicit Lagrangian step with an explicit Eulerian advection step. Individual materials obey separate energy equations, fulfill general equations of state, and may possess different temperatures. Material volume is tracked using a piecewise linear volume-of-fluid method. An overshoot-free logically simple and economic material advection algorithm for cylinder coordinates is derived, in an algebraic formulation. New aspects arising in the case of more than two materials such as the material ordering strategy during transport are presented. One- and two-dimensional numerical examples are given.

Automatic Registration of GF4 Pms: a High Resolution Multi-Spectral Sensor on Board a Satellite on Geostationary Orbit

NASA Astrophysics Data System (ADS)

Gao, M.; Li, J.

2018-04-01

Geometric correction is an important preprocessing process in the application of GF4 PMS image. The method of geometric correction that is based on the manual selection of geometric control points is time-consuming and laborious. The more common method, based on a reference image, is automatic image registration. This method involves several steps and parameters. For the multi-spectral sensor GF4 PMS, it is necessary for us to identify the best combination of parameters and steps. This study mainly focuses on the following issues: necessity of Rational Polynomial Coefficients (RPC) correction before automatic registration, base band in the automatic registration and configuration of GF4 PMS spatial resolution.

How to Start, Build and Sustain a Multi-Credit Integrated Curriculum Package

ERIC Educational Resources Information Center

Wilson, Andrew Kerr

2011-01-01

Over the last 17 years, the author has been asked many times for help starting Integrated Curriculum Programs (ICPs). Visiting teachers are instantly engaged and enthused by the possibilities they see in his program. In this article, he provides a step-by-step road map to a full ICP continuum. By distilling the lessons of almost 20 years of…

A Hybrid, Large-Scale Wireless Sensor Network for Real-Time Acquisition and Tracking

DTIC Science & Technology

2007-06-01

multicolor, Quantum Well Infrared Photodetector ( QWIP ), step-stare, large-format Focal Plane Array (FPA) is proposed and evaluated through performance...Photodetector ( QWIP ), step-stare, large-format Focal Plane Array (FPA) is proposed and evaluated through performance analysis. The thesis proposes...7 1. Multi-color IR Sensors - Operational Advantages ...........................8 2. Quantum-Well IR Photodetector ( QWIP

Individualized In-Service Teacher Education. (Project IN-STEP). Evaluation Report, Phase II.

ERIC Educational Resources Information Center

Thurber, John C.

Phase 2 of Project IN-STEP was conducted to revise, refine, and conduct further field testing of a new inservice teacher education model. The method developed (in Phase 1--see ED 003 905 for report) is an individualized, multi-media approach. Revision activities, based on feedback provided for Phase 1, include the remaking of six videotape…

Challenging Behavior Step-by-Step Sifting: Part 4--Critical Needs

ERIC Educational Resources Information Center

Duffy, Roslyn Ann

2010-01-01

What causes challenging behavior and what can adults do about it? That is a basic question parents and caregivers face everyday. Some needs are easy to meet, others take more work, and some require outside help. This article is the fourth and final segment of a multi-part series about dealing with Challenging Behavior, both at home and school. The…

76 FR 39898 - In the Matter of Certain Electronic Devices With Multi-Touch Enabled Touchpads and Touchscreens...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-07

... take no position on the ALJ's claim construction ruling that the ``scanning'' step of independent claim... to review and take no position on the ALJ's finding that the ``scanning'' step of independent claim 1... further determined to adopt the remainder of the ID to the extent it is not based on these claim...

English for Everyday Activities: A Picture Process Dictionary.

ERIC Educational Resources Information Center

Zwier, Lawrence J.

These books are designed to help English-as-a-Second-Language (ESL) students learn the skills they need to communicate the step-by-step aspects of daily activities. Unlike most picture dictionaries, this is a verb-based multi-skills program that uses a student text with a clear and colorful pictorial detail as a starting point and focuses on the…

Detonation Diffraction in a Multi-Step Channel

DTIC Science & Technology

2010-12-01

openings. This allowed the detonation wave diffraction transmission limits to be determined for hydrogen/air mixtures and to better understand...imaging systems to provide shock wave detail and velocity information. The images were observed through a newly designed explosive proof optical section...stepped openings. This allowed the detonation wave diffraction transmission limits to be determined for hydrogen/air mixtures and to better

A self-consistent first-principle based approach to model carrier mobility in organic materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meded, Velimir; Friederich, Pascal; Symalla, Franz

2015-12-31

Transport through thin organic amorphous films, utilized in OLEDs and OPVs, has been a challenge to model by using ab-initio methods. Charge carrier mobility depends strongly on the disorder strength and reorganization energy, both of which are significantly affected by the details in environment of each molecule. Here we present a multi-scale approach to describe carrier mobility in which the materials morphology is generated using DEPOSIT, a Monte Carlo based atomistic simulation approach, or, alternatively by molecular dynamics calculations performed with GROMACS. From this morphology we extract the material specific hopping rates, as well as the on-site energies using amore » fully self-consistent embedding approach to compute the electronic structure parameters, which are then used in an analytic expression for the carrier mobility. We apply this strategy to compute the carrier mobility for a set of widely studied molecules and obtain good agreement between experiment and theory varying over several orders of magnitude in the mobility without any freely adjustable parameters. The work focuses on the quantum mechanical step of the multi-scale workflow, explains the concept along with the recently published workflow optimization, which combines density functional with semi-empirical tight binding approaches. This is followed by discussion on the analytic formula and its agreement with established percolation fits as well as kinetic Monte Carlo numerical approaches. Finally, we skatch an unified multi-disciplinary approach that integrates materials science simulation and high performance computing, developed within EU project MMM@HPC.« less

Individual-specific multi-scale finite element simulation of cortical bone of human proximal femur

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ascenzi, Maria-Grazia, E-mail: mgascenzi@mednet.ucla.edu; Kawas, Neal P., E-mail: nealkawas@ucla.edu; Lutz, Andre, E-mail: andre.lutz@hotmail.de

2013-07-01

We present an innovative method to perform multi-scale finite element analyses of the cortical component of the femur using the individual’s (1) computed tomography scan; and (2) a bone specimen obtained in conjunction with orthopedic surgery. The method enables study of micro-structural characteristics regulating strains and stresses under physiological loading conditions. The analysis of the micro-structural scenarios that cause variation of strain and stress is the first step in understanding the elevated strains and stresses in bone tissue, which are indicative of higher likelihood of micro-crack formation in bone, implicated in consequent remodeling or macroscopic bone fracture. Evidence that micro-structuremore » varies with clinical history and contributes in significant, but poorly understood, ways to bone function, motivates the method’s development, as does need for software tools to investigate relationships between macroscopic loading and micro-structure. Three applications – varying region of interest, bone mineral density, and orientation of collagen type I, illustrate the method. We show, in comparison between physiological loading and simple compression of a patient’s femur, that strains computed at the multi-scale model’s micro-level: (i) differ; and (ii) depend on local collagen-apatite orientation and degree of calcification. Our findings confirm the strain concentration role of osteocyte lacunae, important for mechano-transduction. We hypothesize occurrence of micro-crack formation, leading either to remodeling or macroscopic fracture, when the computed strains exceed the elastic range observed in micro-structural testing.« less

Joint Labeling Of Multiple Regions of Interest (Rois) By Enhanced Auto Context Models.

PubMed

Kim, Minjeong; Wu, Guorong; Guo, Yanrong; Shen, Dinggang

2015-04-01

Accurate segmentation of a set of regions of interest (ROIs) in the brain images is a key step in many neuroscience studies. Due to the complexity of image patterns, many learning-based segmentation methods have been proposed, including auto context model (ACM) that can capture high-level contextual information for guiding segmentation. However, since current ACM can only handle one ROI at a time, neighboring ROIs have to be labeled separately with different ACMs that are trained independently without communicating each other. To address this, we enhance the current single-ROI learning ACM to multi-ROI learning ACM for joint labeling of multiple neighboring ROIs (called e ACM). First, we extend current independently-trained single-ROI ACMs to a set of jointly-trained cross-ROI ACMs, by simultaneous training of ACMs for all spatially-connected ROIs to let them to share their respective intermediate outputs for coordinated labeling of each image point. Then, the context features in each ACM can capture the cross-ROI dependence information from the outputs of other ACMs that are designed for neighboring ROIs. Second, we upgrade the output labeling map of each ACM with the multi-scale representation, thus both local and global context information can be effectively used to increase the robustness in characterizing geometric relationship among neighboring ROIs. Third, we integrate ACM into a multi-atlases segmentation paradigm, for encompassing high variations among subjects. Experiments on LONI LPBA40 dataset show much better performance by our e ACM, compared to the conventional ACM.

Implementation of Pass Through PPTP Relay System with Authentication at Each Gateway and Its Performance Evaluations

NASA Astrophysics Data System (ADS)

Saito, Shoichi; Uehara, Tetsutaro; Izumi, Yutaka; Kunieda, Yoshitoshi

The VPN (Virtual Private Network) technique becomes more and more popular to protect contents of messages and to achieve secure communication from incidents, such as tapping. However, it grow in usage that a VPN server is used on a sub-network in part of an office-wide network. But, a PPTP system included in Windows operating systems cannot establish nested VPN links. Moreover encrypted communication by VPN hides a user of the VPN connection. Consequently, any administrators of network systems can’t find out the users of the VPN connection via firewall, moreover can’t decide whether if the user is legal or not. In order to solve this problem, we developed a multi step PPTP relay system on a firewall. This system solves all the problems of our previously developed PPTP relay system(1). The new relay system improves security by encrypting through the whole end-to-end communication and abolishing of prior registration of passwords for the next step. Furthermore, transport speed is accelerated, and the restriction of the number of steps on relay is also abolished. By these features the multi step PPTP relay system expands usability.

Design and Processing of a Novel Chaos-Based Stepped Frequency Synthesized Wideband Radar Signal.

PubMed

Zeng, Tao; Chang, Shaoqiang; Fan, Huayu; Liu, Quanhua

2018-03-26

The linear stepped frequency and linear frequency shift keying (FSK) signal has been widely used in radar systems. However, such linear modulation signals suffer from the range-Doppler coupling that degrades radar multi-target resolution. Moreover, the fixed frequency-hopping or frequency-coded sequence can be easily predicted by the interception receiver in the electronic countermeasures (ECM) environments, which limits radar anti-jamming performance. In addition, the single FSK modulation reduces the radar low probability of intercept (LPI) performance, for it cannot achieve a large time-bandwidth product. To solve such problems, we propose a novel chaos-based stepped frequency (CSF) synthesized wideband signal in this paper. The signal introduces chaotic frequency hopping between the coherent stepped frequency pulses, and adopts a chaotic frequency shift keying (CFSK) and phase shift keying (PSK) composited coded modulation in a subpulse, called CSF-CFSK/PSK. Correspondingly, the processing method for the signal has been proposed. According to our theoretical analyses and the simulations, the proposed signal and processing method achieve better multi-target resolution and LPI performance. Furthermore, flexible modulation is able to increase the robustness against identification of the interception receiver and improve the anti-jamming performance of the radar.

Multi-Model Combination techniques for Hydrological Forecasting: Application to Distributed Model Intercomparison Project Results

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ajami, N K; Duan, Q; Gao, X

2005-04-11

This paper examines several multi-model combination techniques: the Simple Multi-model Average (SMA), the Multi-Model Super Ensemble (MMSE), Modified Multi-Model Super Ensemble (M3SE) and the Weighted Average Method (WAM). These model combination techniques were evaluated using the results from the Distributed Model Intercomparison Project (DMIP), an international project sponsored by the National Weather Service (NWS) Office of Hydrologic Development (OHD). All of the multi-model combination results were obtained using uncalibrated DMIP model outputs and were compared against the best uncalibrated as well as the best calibrated individual model results. The purpose of this study is to understand how different combination techniquesmore » affect the skill levels of the multi-model predictions. This study revealed that the multi-model predictions obtained from uncalibrated single model predictions are generally better than any single member model predictions, even the best calibrated single model predictions. Furthermore, more sophisticated multi-model combination techniques that incorporated bias correction steps work better than simple multi-model average predictions or multi-model predictions without bias correction.« less

Influence of Natural Convection and Thermal Radiation Multi-Component Transport in MOCVD Reactors

NASA Technical Reports Server (NTRS)

Lowry, S.; Krishnan, A.; Clark, I.

1999-01-01

The influence of Grashof and Reynolds number in Metal Organic Chemical Vapor (MOCVD) reactors is being investigated under a combined empirical/numerical study. As part of that research, the deposition of Indium Phosphide in an MOCVD reactor is modeled using the computational code CFD-ACE. The model includes the effects of convection, conduction, and radiation as well as multi-component diffusion and multi-step surface/gas phase chemistry. The results of the prediction are compared with experimental data for a commercial reactor and analyzed with respect to the model accuracy.

A Fuzzy Goal Programming for a Multi-Depot Distribution Problem

NASA Astrophysics Data System (ADS)

Nunkaew, Wuttinan; Phruksaphanrat, Busaba

2010-10-01

A fuzzy goal programming model for solving a Multi-Depot Distribution Problem (MDDP) is proposed in this research. This effective proposed model is applied for solving in the first step of Assignment First-Routing Second (AFRS) approach. Practically, a basic transportation model is firstly chosen to solve this kind of problem in the assignment step. After that the Vehicle Routing Problem (VRP) model is used to compute the delivery cost in the routing step. However, in the basic transportation model, only depot to customer relationship is concerned. In addition, the consideration of customer to customer relationship should also be considered since this relationship exists in the routing step. Both considerations of relationships are solved using Preemptive Fuzzy Goal Programming (P-FGP). The first fuzzy goal is set by a total transportation cost and the second fuzzy goal is set by a satisfactory level of the overall independence value. A case study is used for describing the effectiveness of the proposed model. Results from the proposed model are compared with the basic transportation model that has previously been used in this company. The proposed model can reduce the actual delivery cost in the routing step owing to the better result in the assignment step. Defining fuzzy goals by membership functions are more realistic than crisps. Furthermore, flexibility to adjust goals and an acceptable satisfactory level for decision maker can also be increased and the optimal solution can be obtained.

Robust model predictive control for multi-step short range spacecraft rendezvous

NASA Astrophysics Data System (ADS)

Zhu, Shuyi; Sun, Ran; Wang, Jiaolong; Wang, Jihe; Shao, Xiaowei

2018-07-01

This work presents a robust model predictive control (MPC) approach for the multi-step short range spacecraft rendezvous problem. During the specific short range phase concerned, the chaser is supposed to be initially outside the line-of-sight (LOS) cone. Therefore, the rendezvous process naturally includes two steps: the first step is to transfer the chaser into the LOS cone and the second step is to transfer the chaser into the aimed region with its motion confined within the LOS cone. A novel MPC framework named after Mixed MPC (M-MPC) is proposed, which is the combination of the Variable-Horizon MPC (VH-MPC) framework and the Fixed-Instant MPC (FI-MPC) framework. The M-MPC framework enables the optimization for the two steps to be implemented jointly rather than to be separated factitiously, and its computation workload is acceptable for the usually low-power processors onboard spacecraft. Then considering that disturbances including modeling error, sensor noise and thrust uncertainty may induce undesired constraint violations, a robust technique is developed and it is attached to the above M-MPC framework to form a robust M-MPC approach. The robust technique is based on the chance-constrained idea, which ensures that constraints can be satisfied with a prescribed probability. It improves the robust technique proposed by Gavilan et al., because it eliminates the unnecessary conservativeness by explicitly incorporating known statistical properties of the navigation uncertainty. The efficacy of the robust M-MPC approach is shown in a simulation study.

RIBEYE(B)-domain binds to lipid components of synaptic vesicles in an NAD(H)-dependent, redox-sensitive manner.

PubMed

Schwarz, Karin; Schmitz, Frank

2017-03-20

Synaptic ribbons are needed for fast and continuous exocytosis in ribbon synapses. RIBEYE is a main protein component of synaptic ribbons and is necessary to build the synaptic ribbon. RIBEYE consists of a unique A-domain and a carboxyterminal B-domain, which binds NAD(H). Within the presynaptic terminal, the synaptic ribbons are in physical contact with large numbers of synaptic vesicle (SV)s. How this physical contact between ribbons and synaptic vesicles is established at a molecular level is not well understood. In the present study, we demonstrate that the RIBEYE(B)-domain can directly interact with lipid components of SVs using two different sedimentation assays with liposomes of defined chemical composition. Similar binding results were obtained with a SV-containing membrane fraction. The binding of liposomes to RIBEYE(B) depends upon the presence of a small amount of lysophospholipids present in the liposomes. Interestingly, binding of liposomes to RIBEYE(B) depends on NAD(H) in a redox-sensitive manner. The binding is enhanced by NADH, the reduced form, and is inhibited by NAD + , the oxidized form. Lipid-mediated attachment of vesicles is probably part of a multi-step process that also involves additional, protein-dependent processes. © 2017 The Author(s); published by Portland Press Limited on behalf of the Biochemical Society.

Development of a time-dependent incompressible Navier-Stokes solver based on a fractional-step method

NASA Technical Reports Server (NTRS)

Rosenfeld, Moshe

1990-01-01

The main goals are the development, validation, and application of a fractional step solution method of the time-dependent incompressible Navier-Stokes equations in generalized coordinate systems. A solution method that combines a finite volume discretization with a novel choice of the dependent variables and a fractional step splitting to obtain accurate solutions in arbitrary geometries is extended to include more general situations, including cases with moving grids. The numerical techniques are enhanced to gain efficiency and generality.

A DACE study on a three stage metal forming process made of Sandvik Nanoflex™

NASA Astrophysics Data System (ADS)

Post, J.; Klaseboer, G.; Stinstra, E.; Huétink, J.

2004-06-01

Sandvik Nanoflex™ combines good corrosion resistance with high strength. The steel has good deformability in austenitic conditions. This material belongs to the group of metastable austenites, so during deformation a strain-induced transformation into martensite takes place. After deformation, the transformation continues as a result of internal residual stresses. Depending on the heat treatment, this stress-assisted transformation is more or less autocatalytic. Both transformations are stress-state, temperature and crystal orientation dependent. This article presents a constitutive model for this steel, based on the macroscopic material behaviour measured by inductive measurements. Both the stress-assisted and the strain-induced transformation to martensite are incorporated in this model. Path-dependent work hardening is also taken into account, together with the inheritance of the dislocations from one phase to the other. The model is implemented in an internal Philips code called CRYSTAL for doing simulations. A multi-stage metal forming process is simulated. The process consists of different forming steps with intervals between them to simulate the waiting time between the different metal forming steps. During the engineering process of a high precision metal formed product often questions arise about the relation between the scatter on the initial parameters, like standard deviation on the strip thickness, yield stress etc, and the product accuracy. This becomes even more complex if the material is: • instable, • the transformation rate depends on the stress state, which is related to friction, • the transformation rate depends on the temperature, which is related to deformation heat and the heat distribution during the entire process. A way to get more understanding in these phenomena in relation to the process is doing a process window study, using DACE (Design and Analysis of Computer Experiments). In this article an example is given how to make a DACE study on a a three stage metal forming process, using a distributed computing technique. The method is shown, together with some results. The problem is focused on the influence of the transformation rate, transformation plasticity and dilatation strain on the product accuracy.

Discovering the Past through Data: Promoting the Design and Analysis of Original Data-Sets in History Undergraduate Courses in Hong Kong

ERIC Educational Resources Information Center

Kim, Loretta; Wong, Shun Han Rebekah

2015-01-01

This article discusses the objectives and outcomes of a project to enhance digital humanities training at the undergraduate level in a Hong Kong university. The co-investigators re-designed a multi-source data-set as an example and then taught a multi-step curriculum about gathering, organizing, and presenting original data to an introductory…

Books Only Got Us so Far: The Need for Multi-Genre Inquiry

ERIC Educational Resources Information Center

Jewett, Pamela

2010-01-01

This study examines the instructional steps I took, based on gaps between what was happening in a graduate literacy class I taught and what I had intended to happen. This study describes the ways that I re-imagined the class and what came about when I created a pedagogical approach that featured multi-genre inquiry. I define inter-discursivity as…

The Role of School and Individual Differences in the Academic Attainment of Learners with Special Educational Needs and Disabilities: A Multi-Level Analysis

ERIC Educational Resources Information Center

Humphrey, Neil; Wigelsworth, Michael; Barlow, Alexandra; Squires, Garry

2013-01-01

Students with special educational needs and disabilities (SEND) are at a greatly increased risk of poor academic outcomes. Understanding the factors that influence their attainment is a crucial first step towards developing more effective provision. In the current study we present a multi-level, natural variation analysis which highlights…

Multi-object investigation using two-wavelength phase-shift interferometry guided by an optical frequency comb

NASA Astrophysics Data System (ADS)

Ibrahim, Dahi Ghareab Abdelsalam; Yasui, Takeshi

2018-04-01

Two-wavelength phase-shift interferometry guided by optical frequency combs is presented. We demonstrate the operation of the setup with a large step sample simultaneously with a resolution test target with a negative pattern. The technique can investigate multi-objects simultaneously with high precision. Using this technique, several important applications in metrology that require high speed and precision are demonstrated.

Multi-scale modelling of non-uniform consolidation of uncured toughened unidirectional prepregs

NASA Astrophysics Data System (ADS)

Sorba, G.; Binetruy, C.; Syerko, E.; Leygue, A.; Comas-Cardona, S.; Belnoue, J. P.-H.; Nixon-Pearson, O. J.; Ivanov, D. S.; Hallett, S. R.; Advani, S. G.

2018-05-01

Consolidation is a crucial step in manufacturing of composite parts with prepregs because its role is to eliminate inter- and intra-ply gaps and porosity. Some thermoset prepreg systems are toughened with thermoplastic particles. Depending on their size, thermoplastic particles can be either located in between plies or distributed within the inter-fibre regions. When subjected to transverse compaction, resin will bleed out of low-viscosity unidirectional prepregs along the fibre direction, whereas one would expect transverse squeeze flow to dominate for higher viscosity prepregs. Recent experimental work showed that the consolidation of uncured toughened prepregs involves complex flow and deformation mechanisms where both bleeding and squeeze flow patterns are observed [1]. Micrographs of compacted and cured samples confirm these features as shown in Fig.1. A phenomenological model was proposed [2] where bleeding flow and squeeze flow are combined. A criterion for the transition from shear flow to resin bleeding was also proposed. However, the micrographs also reveal a resin rich layer between plies which may be contributing to the complex flow mechanisms during the consolidation process. In an effort to provide additional insight into these complex mechanisms, this work focuses on the 3D numerical modelling of the compaction of uncured toughened prepregs in the cross-ply configuration described in [1]. A transversely isotropic fluid model is used to describe the flow behaviour of the plies coupled with interplay resin flow of an isotropic fluid. The multi-scale flow model used is based on [3, 4]. A numerical parametric study is carried out where the resin viscosity, permeability and inter-ply thickness are varied to identify the role of important variables. The squeezing flow and the bleeding flow are compared for a range of process parameters to investigate the coupling and competition between the two flow mechanisms. Figure 4 shows the predicted displacement of the sample edge with the multi-scale compaction model after one time step [3]. The ply distortion and resin flow observed in Fig.1 is qualitatively retrieved by the computational model.

Waste Heat Approximation for Understanding Dynamic Compression in Nature and Experiments

NASA Astrophysics Data System (ADS)

Jeanloz, R.

2015-12-01

Energy dissipated during dynamic compression quantifies the residual heat left in a planet due to impact and accretion, as well as the deviation of a loading path from an ideal isentrope. Waste heat ignores the difference between the pressure-volume isentrope and Hugoniot in approximating the dissipated energy as the area between the Rayleigh line and Hugoniot (assumed given by a linear dependence of shock velocity on particle velocity). Strength and phase transformations are ignored: justifiably, when considering sufficiently high dynamic pressures and reversible transformations. Waste heat mis-estimates the dissipated energy by less than 10-20 percent for volume compressions under 30-60 percent. Specific waste heat (energy per mass) reaches 0.2-0.3 c02 at impact velocities 2-4 times the zero-pressure bulk sound velocity (c0), its maximum possible value being 0.5 c02. As larger impact velocities are implied for typical orbital velocities of Earth-like planets, and c02 ≈ 2-30 MJ/kg for rock, the specific waste heat due to accretion corresponds to temperature rises of about 3-15 x 103 K for rock: melting accompanies accretion even with only 20-30 percent waste heat retained. Impact sterilization is similarly quantified in terms of waste heat relative to the energy required to vaporize H2O (impact velocity of 7-8 km/s, or 4.5-5 c0, is sufficient). Waste heat also clarifies the relationship between shock, multi-shock and ramp loading experiments, as well as the effect of (static) pre-compression. Breaking a shock into 2 steps significantly reduces the dissipated energy, with minimum waste heat achieved for two equal volume compressions in succession. Breaking a shock into as few as 4 steps reduces the waste heat to within a few percent of zero, documenting how multi-shock loading approaches an isentrope. Pre-compression, being less dissipative than an initial shock to the same strain, further reduces waste heat. Multi-shock (i.e., high strain-rate) loading of pre-compressed samples may thus offer the closest approach to an isentrope, and therefore the most extreme compression at which matter can be studied at the "warm" temperatures of planetary interiors.

Selecting a climate model subset to optimise key ensemble properties

NASA Astrophysics Data System (ADS)

Herger, Nadja; Abramowitz, Gab; Knutti, Reto; Angélil, Oliver; Lehmann, Karsten; Sanderson, Benjamin M.

2018-02-01

End users studying impacts and risks caused by human-induced climate change are often presented with large multi-model ensembles of climate projections whose composition and size are arbitrarily determined. An efficient and versatile method that finds a subset which maintains certain key properties from the full ensemble is needed, but very little work has been done in this area. Therefore, users typically make their own somewhat subjective subset choices and commonly use the equally weighted model mean as a best estimate. However, different climate model simulations cannot necessarily be regarded as independent estimates due to the presence of duplicated code and shared development history. Here, we present an efficient and flexible tool that makes better use of the ensemble as a whole by finding a subset with improved mean performance compared to the multi-model mean while at the same time maintaining the spread and addressing the problem of model interdependence. Out-of-sample skill and reliability are demonstrated using model-as-truth experiments. This approach is illustrated with one set of optimisation criteria but we also highlight the flexibility of cost functions, depending on the focus of different users. The technique is useful for a range of applications that, for example, minimise present-day bias to obtain an accurate ensemble mean, reduce dependence in ensemble spread, maximise future spread, ensure good performance of individual models in an ensemble, reduce the ensemble size while maintaining important ensemble characteristics, or optimise several of these at the same time. As in any calibration exercise, the final ensemble is sensitive to the metric, observational product, and pre-processing steps used.

Multi-residue determination of seventeen sulfonamides and five tetracyclines in fish tissue using a multi-stage LC-ESI-MS/MS approach based on advanced mass spectrometric techniques.

PubMed

Dasenaki, Marilena E; Thomaidis, Nikolaos S

2010-07-05

A strategy was newly developed to rapidly screen seventeen sulfonamides and five tetracyclines in a single run from fish tissues using ultra-high performance liquid chromatography (UHPLC) coupled with comprehensive mass spectrometric approaches, including precursor-ion scan and data dependent scan. The product ions for precursor-ion scanning were selected by studying the MS/MS fragmentation of the analytes. All sulfonamides share the same diagnostic product ion at m/z 156 in positive MS/MS scan, while for tetracycline antibiotics the diagnostic product ion was proved to be at m/z 153.8. Further characterization of each compound was performed using a data dependent scan. Separation was performed on a Zorbax Eclipse Plus C18 column with a gradient elution using acetonitrile - 0.1% formic acid mobile phase at a flow rate of 0.1 mL min(-1). This approach has proven to be a powerful, highly selective, and sensitive tool for rapid screening and detection of non-targeted components in fish tissue and requires a minimum sample preparation such as one generic extraction step with MeOH:ACN 50:50 (v/v) acidified with 0.05% formic acid. The method has also been applied successfully to porcine and poultry meat. The validation of such a screening method was performed for the first time according to Commission Decision 2002/657/EC and satisfactory method performance characteristics were achieved. Copyright 2010 Elsevier B.V. All rights reserved.

Managing Multi-center Flow Cytometry Data for Immune Monitoring

PubMed Central

White, Scott; Laske, Karoline; Welters, Marij JP; Bidmon, Nicole; van der Burg, Sjoerd H; Britten, Cedrik M; Enzor, Jennifer; Staats, Janet; Weinhold, Kent J; Gouttefangeas, Cécile; Chan, Cliburn

2014-01-01

With the recent results of promising cancer vaccines and immunotherapy1–5, immune monitoring has become increasingly relevant for measuring treatment-induced effects on T cells, and an essential tool for shedding light on the mechanisms responsible for a successful treatment. Flow cytometry is the canonical multi-parameter assay for the fine characterization of single cells in solution, and is ubiquitously used in pre-clinical tumor immunology and in cancer immunotherapy trials. Current state-of-the-art polychromatic flow cytometry involves multi-step, multi-reagent assays followed by sample acquisition on sophisticated instruments capable of capturing up to 20 parameters per cell at a rate of tens of thousands of cells per second. Given the complexity of flow cytometry assays, reproducibility is a major concern, especially for multi-center studies. A promising approach for improving reproducibility is the use of automated analysis borrowing from statistics, machine learning and information visualization21–23, as these methods directly address the subjectivity, operator-dependence, labor-intensive and low fidelity of manual analysis. However, it is quite time-consuming to investigate and test new automated analysis techniques on large data sets without some centralized information management system. For large-scale automated analysis to be practical, the presence of consistent and high-quality data linked to the raw FCS files is indispensable. In particular, the use of machine-readable standard vocabularies to characterize channel metadata is essential when constructing analytic pipelines to avoid errors in processing, analysis and interpretation of results. For automation, this high-quality metadata needs to be programmatically accessible, implying the need for a consistent Application Programming Interface (API). In this manuscript, we propose that upfront time spent normalizing flow cytometry data to conform to carefully designed data models enables automated analysis, potentially saving time in the long run. The ReFlow informatics framework was developed to address these data management challenges. PMID:26085786

A scale-entropy diffusion equation to describe the multi-scale features of turbulent flames near a wall

NASA Astrophysics Data System (ADS)

Queiros-Conde, D.; Foucher, F.; Mounaïm-Rousselle, C.; Kassem, H.; Feidt, M.

2008-12-01

Multi-scale features of turbulent flames near a wall display two kinds of scale-dependent fractal features. In scale-space, an unique fractal dimension cannot be defined and the fractal dimension of the front is scale-dependent. Moreover, when the front approaches the wall, this dependency changes: fractal dimension also depends on the wall-distance. Our aim here is to propose a general geometrical framework that provides the possibility to integrate these two cases, in order to describe the multi-scale structure of turbulent flames interacting with a wall. Based on the scale-entropy quantity, which is simply linked to the roughness of the front, we thus introduce a general scale-entropy diffusion equation. We define the notion of “scale-evolutivity” which characterises the deviation of a multi-scale system from the pure fractal behaviour. The specific case of a constant “scale-evolutivity” over the scale-range is studied. In this case, called “parabolic scaling”, the fractal dimension is a linear function of the logarithm of scale. The case of a constant scale-evolutivity in the wall-distance space implies that the fractal dimension depends linearly on the logarithm of the wall-distance. We then verified experimentally, that parabolic scaling represents a good approximation of the real multi-scale features of turbulent flames near a wall.

Two-dimensional correlation and codistribution spectroscopy (2DCOS and 2DCDS) analyses of time-dependent ATR IR spectra of D-glucose anomers undergoing mutarotation process in water

NASA Astrophysics Data System (ADS)

Noda, Isao

2018-05-01

Two cyclic diastereoisomeric structures, known as α- and β-anomers of D-glucose with different configurations around C1 with OH groups in axial or equitroial positions, undergo the mutarotation conversion to each other in water. Two-dimensional correlation and codistribution spectroscopy (2DCOS and 2DCDS) analyses were applied to the time-dependent ATR IR spectra of aqueous solutions of α- and β-D-glucose undergoing such mutarotation conversion. 2DCOS analysis reveals that the increase and decrease in the IR intensities after the dissolution of α- or β-D-glucose are not fully synchronized, suggesting the mutarotation of D-glucose in water is not a simple binary conversion process but a multi-step reaction involving an intermediate species with a finite and observable concentration level and lifetime. 2DCDS analysis of the time-dependent ATR IR spectra clearly demonstrated the presence of intermediate species contributing to the band positions overlapped close to bands for α- and β-D-glucose. The fact that band positions identified for the intermediate species for α- to β-D-glucose conversion are the same for the reverse reaction suggests that they arise from the same species, most likely the open-ring structure produced by the hydrolysis.

Multi-step Variable Height Photolithography for Valved Multilayer Microfluidic Devices.

PubMed

Brower, Kara; White, Adam K; Fordyce, Polly M

2017-01-27

Microfluidic systems have enabled powerful new approaches to high-throughput biochemical and biological analysis. However, there remains a barrier to entry for non-specialists who would benefit greatly from the ability to develop their own microfluidic devices to address research questions. Particularly lacking has been the open dissemination of protocols related to photolithography, a key step in the development of a replica mold for the manufacture of polydimethylsiloxane (PDMS) devices. While the fabrication of single height silicon masters has been explored extensively in literature, fabrication steps for more complicated photolithography features necessary for many interesting device functionalities (such as feature rounding to make valve structures, multi-height single-mold patterning, or high aspect ratio definition) are often not explicitly outlined. Here, we provide a complete protocol for making multilayer microfluidic devices with valves and complex multi-height geometries, tunable for any application. These fabrication procedures are presented in the context of a microfluidic hydrogel bead synthesizer and demonstrate the production of droplets containing polyethylene glycol (PEG diacrylate) and a photoinitiator that can be polymerized into solid beads. This protocol and accompanying discussion provide a foundation of design principles and fabrication methods that enables development of a wide variety of microfluidic devices. The details included here should allow non-specialists to design and fabricate novel devices, thereby bringing a host of recently developed technologies to their most exciting applications in biological laboratories.

Development of a multi-criteria evaluation system to assess growing pig welfare.

PubMed

Martín, P; Traulsen, I; Buxadé, C; Krieter, J

2017-03-01

The aim of this paper was to present an alternative multi-criteria evaluation model to assess animal welfare on farms based on the Welfare Quality® (WQ) project, using an example of welfare assessment of growing pigs. The WQ assessment protocol follows a three-step aggregation process. Measures are aggregated into criteria, criteria into principles and principles into an overall assessment. This study focussed on the first step of the aggregation. Multi-attribute utility theory (MAUT) was used to produce a value of welfare for each criterion. The utility functions and the aggregation function were constructed in two separated steps. The Measuring Attractiveness by a Categorical Based Evaluation Technique (MACBETH) method was used for utility function determination and the Choquet Integral (CI) was used as an aggregation operator. The WQ decision-makers' preferences were fitted in order to construct the utility functions and to determine the CI parameters. The methods were tested with generated data sets for farms of growing pigs. Using the MAUT, similar results were obtained to the ones obtained applying the WQ protocol aggregation methods. It can be concluded that due to the use of an interactive approach such as MACBETH, this alternative methodology is more transparent and more flexible than the methodology proposed by WQ, which allows the possibility to modify the model according, for instance, to new scientific knowledge.

Stall/surge dynamics of a multi-stage air compressor in response to a load transient of a hybrid solid oxide fuel cell-gas turbine system

NASA Astrophysics Data System (ADS)

Azizi, Mohammad Ali; Brouwer, Jacob

2017-10-01

A better understanding of turbulent unsteady flows in gas turbine systems is necessary to design and control compressors for hybrid fuel cell-gas turbine systems. Compressor stall/surge analysis for a 4 MW hybrid solid oxide fuel cell-gas turbine system for locomotive applications is performed based upon a 1.7 MW multi-stage air compressor. Control strategies are applied to prevent operation of the hybrid SOFC-GT beyond the stall/surge lines of the compressor. Computational fluid dynamics tools are used to simulate the flow distribution and instabilities near the stall/surge line. The results show that a 1.7 MW system compressor like that of a Kawasaki gas turbine is an appropriate choice among the industrial compressors to be used in a 4 MW locomotive SOFC-GT with topping cycle design. The multi-stage radial design of the compressor enhances the ability of the compressor to maintain air flow rate during transient step-load changes. These transient step-load changes are exhibited in many potential applications for SOFC/GT systems. The compressor provides sustained air flow rate during the mild stall/surge event that occurs due to the transient step-load change that is applied, indicating that this type of compressor is well-suited for this hybrid application.

Abundance and composition of indigenous bacterial communities in a multi-step biofiltration-based drinking water treatment plant.

PubMed

Lautenschlager, Karin; Hwang, Chiachi; Ling, Fangqiong; Liu, Wen-Tso; Boon, Nico; Köster, Oliver; Egli, Thomas; Hammes, Frederik

2014-10-01

Indigenous bacterial communities are essential for biofiltration processes in drinking water treatment systems. In this study, we examined the microbial community composition and abundance of three different biofilter types (rapid sand, granular activated carbon, and slow sand filters) and their respective effluents in a full-scale, multi-step treatment plant (Zürich, CH). Detailed analysis of organic carbon degradation underpinned biodegradation as the primary function of the biofilter biomass. The biomass was present in concentrations ranging between 2-5 × 10(15) cells/m(3) in all filters but was phylogenetically, enzymatically and metabolically diverse. Based on 16S rRNA gene-based 454 pyrosequencing analysis for microbial community composition, similar microbial taxa (predominantly Proteobacteria, Planctomycetes, Acidobacteria, Bacteriodetes, Nitrospira and Chloroflexi) were present in all biofilters and in their respective effluents, but the ratio of microbial taxa was different in each filter type. This change was also reflected in the cluster analysis, which revealed a change of 50-60% in microbial community composition between the different filter types. This study documents the direct influence of the filter biomass on the microbial community composition of the final drinking water, particularly when the water is distributed without post-disinfection. The results provide new insights on the complexity of indigenous bacteria colonizing drinking water systems, especially in different biofilters of a multi-step treatment plant. Copyright © 2014 Elsevier Ltd. All rights reserved.

A Novel Multi-Sensor Environmental Perception Method Using Low-Rank Representation and a Particle Filter for Vehicle Reversing Safety

PubMed Central

Zhang, Zutao; Li, Yanjun; Wang, Fubing; Meng, Guanjun; Salman, Waleed; Saleem, Layth; Zhang, Xiaoliang; Wang, Chunbai; Hu, Guangdi; Liu, Yugang

2016-01-01

Environmental perception and information processing are two key steps of active safety for vehicle reversing. Single-sensor environmental perception cannot meet the need for vehicle reversing safety due to its low reliability. In this paper, we present a novel multi-sensor environmental perception method using low-rank representation and a particle filter for vehicle reversing safety. The proposed system consists of four main steps, namely multi-sensor environmental perception, information fusion, target recognition and tracking using low-rank representation and a particle filter, and vehicle reversing speed control modules. First of all, the multi-sensor environmental perception module, based on a binocular-camera system and ultrasonic range finders, obtains the distance data for obstacles behind the vehicle when the vehicle is reversing. Secondly, the information fusion algorithm using an adaptive Kalman filter is used to process the data obtained with the multi-sensor environmental perception module, which greatly improves the robustness of the sensors. Then the framework of a particle filter and low-rank representation is used to track the main obstacles. The low-rank representation is used to optimize an objective particle template that has the smallest L-1 norm. Finally, the electronic throttle opening and automatic braking is under control of the proposed vehicle reversing control strategy prior to any potential collisions, making the reversing control safer and more reliable. The final system simulation and practical testing results demonstrate the validity of the proposed multi-sensor environmental perception method using low-rank representation and a particle filter for vehicle reversing safety. PMID:27294931

A Novel Multi-Sensor Environmental Perception Method Using Low-Rank Representation and a Particle Filter for Vehicle Reversing Safety.

PubMed

Zhang, Zutao; Li, Yanjun; Wang, Fubing; Meng, Guanjun; Salman, Waleed; Saleem, Layth; Zhang, Xiaoliang; Wang, Chunbai; Hu, Guangdi; Liu, Yugang

2016-06-09

Environmental perception and information processing are two key steps of active safety for vehicle reversing. Single-sensor environmental perception cannot meet the need for vehicle reversing safety due to its low reliability. In this paper, we present a novel multi-sensor environmental perception method using low-rank representation and a particle filter for vehicle reversing safety. The proposed system consists of four main steps, namely multi-sensor environmental perception, information fusion, target recognition and tracking using low-rank representation and a particle filter, and vehicle reversing speed control modules. First of all, the multi-sensor environmental perception module, based on a binocular-camera system and ultrasonic range finders, obtains the distance data for obstacles behind the vehicle when the vehicle is reversing. Secondly, the information fusion algorithm using an adaptive Kalman filter is used to process the data obtained with the multi-sensor environmental perception module, which greatly improves the robustness of the sensors. Then the framework of a particle filter and low-rank representation is used to track the main obstacles. The low-rank representation is used to optimize an objective particle template that has the smallest L-1 norm. Finally, the electronic throttle opening and automatic braking is under control of the proposed vehicle reversing control strategy prior to any potential collisions, making the reversing control safer and more reliable. The final system simulation and practical testing results demonstrate the validity of the proposed multi-sensor environmental perception method using low-rank representation and a particle filter for vehicle reversing safety.

Contributions of dopamine-related genes and environmental factors to highly sensitive personality: a multi-step neuronal system-level approach.

PubMed

Chen, Chunhui; Chen, Chuansheng; Moyzis, Robert; Stern, Hal; He, Qinghua; Li, He; Li, Jin; Zhu, Bi; Dong, Qi

2011-01-01

Traditional behavioral genetic studies (e.g., twin, adoption studies) have shown that human personality has moderate to high heritability, but recent molecular behavioral genetic studies have failed to identify quantitative trait loci (QTL) with consistent effects. The current study adopted a multi-step approach (ANOVA followed by multiple regression and permutation) to assess the cumulative effects of multiple QTLs. Using a system-level (dopamine system) genetic approach, we investigated a personality trait deeply rooted in the nervous system (the Highly Sensitive Personality, HSP). 480 healthy Chinese college students were given the HSP scale and genotyped for 98 representative polymorphisms in all major dopamine neurotransmitter genes. In addition, two environment factors (stressful life events and parental warmth) that have been implicated for their contributions to personality development were included to investigate their relative contributions as compared to genetic factors. In Step 1, using ANOVA, we identified 10 polymorphisms that made statistically significant contributions to HSP. In Step 2, these polymorphism's main effects and interactions were assessed using multiple regression. This model accounted for 15% of the variance of HSP (p<0.001). Recent stressful life events accounted for an additional 2% of the variance. Finally, permutation analyses ascertained the probability of obtaining these findings by chance to be very low, p ranging from 0.001 to 0.006. Dividing these loci by the subsystems of dopamine synthesis, degradation/transport, receptor and modulation, we found that the modulation and receptor subsystems made the most significant contribution to HSP. The results of this study demonstrate the utility of a multi-step neuronal system-level approach in assessing genetic contributions to individual differences in human behavior. It can potentially bridge the gap between the high heritability estimates based on traditional behavioral genetics and the lack of reproducible genetic effects observed currently from molecular genetic studies.

Star sub-pixel centroid calculation based on multi-step minimum energy difference method

NASA Astrophysics Data System (ADS)

Wang, Duo; Han, YanLi; Sun, Tengfei

2013-09-01

The star's centroid plays a vital role in celestial navigation, star images which be gotten during daytime, due to the strong sky background, have a low SNR, and the star objectives are nearly submerged in the background, takes a great trouble to the centroid localization. Traditional methods, such as a moment method, weighted centroid calculation method is simple but has a big error, especially in the condition of a low SNR. Gaussian method has a high positioning accuracy, but the computational complexity. Analysis of the energy distribution in star image, a location method for star target centroids based on multi-step minimum energy difference is proposed. This method uses the linear superposition to narrow the centroid area, in the certain narrow area uses a certain number of interpolation to pixels for the pixels' segmentation, and then using the symmetry of the stellar energy distribution, tentatively to get the centroid position: assume that the current pixel is the star centroid position, and then calculates and gets the difference of the sum of the energy which in the symmetric direction(in this paper we take the two directions of transverse and longitudinal) and the equal step length(which can be decided through different conditions, the paper takes 9 as the step length) of the current pixel, and obtain the centroid position in this direction when the minimum difference appears, and so do the other directions, then the validation comparison of simulated star images, and compare with several traditional methods, experiments shows that the positioning accuracy of the method up to 0.001 pixel, has good effect to calculate the centroid of low SNR conditions; at the same time, uses this method on a star map which got at the fixed observation site during daytime in near-infrared band, compare the results of the paper's method with the position messages which were known of the star, it shows that :the multi-step minimum energy difference method achieves a better effect.

Contributions of Dopamine-Related Genes and Environmental Factors to Highly Sensitive Personality: A Multi-Step Neuronal System-Level Approach

PubMed Central

Chen, Chunhui; Chen, Chuansheng; Moyzis, Robert; Stern, Hal; He, Qinghua; Li, He; Li, Jin; Zhu, Bi; Dong, Qi

2011-01-01

Traditional behavioral genetic studies (e.g., twin, adoption studies) have shown that human personality has moderate to high heritability, but recent molecular behavioral genetic studies have failed to identify quantitative trait loci (QTL) with consistent effects. The current study adopted a multi-step approach (ANOVA followed by multiple regression and permutation) to assess the cumulative effects of multiple QTLs. Using a system-level (dopamine system) genetic approach, we investigated a personality trait deeply rooted in the nervous system (the Highly Sensitive Personality, HSP). 480 healthy Chinese college students were given the HSP scale and genotyped for 98 representative polymorphisms in all major dopamine neurotransmitter genes. In addition, two environment factors (stressful life events and parental warmth) that have been implicated for their contributions to personality development were included to investigate their relative contributions as compared to genetic factors. In Step 1, using ANOVA, we identified 10 polymorphisms that made statistically significant contributions to HSP. In Step 2, these polymorphism's main effects and interactions were assessed using multiple regression. This model accounted for 15% of the variance of HSP (p<0.001). Recent stressful life events accounted for an additional 2% of the variance. Finally, permutation analyses ascertained the probability of obtaining these findings by chance to be very low, p ranging from 0.001 to 0.006. Dividing these loci by the subsystems of dopamine synthesis, degradation/transport, receptor and modulation, we found that the modulation and receptor subsystems made the most significant contribution to HSP. The results of this study demonstrate the utility of a multi-step neuronal system-level approach in assessing genetic contributions to individual differences in human behavior. It can potentially bridge the gap between the high heritability estimates based on traditional behavioral genetics and the lack of reproducible genetic effects observed currently from molecular genetic studies. PMID:21765900

Computational Analysis of Multi-Rotor Flows

NASA Technical Reports Server (NTRS)

Yoon, Seokkwan; Lee, Henry C.; Pulliam, Thomas H.

2016-01-01

Interactional aerodynamics of multi-rotor flows has been studied for a quadcopter representing a generic quad tilt-rotor aircraft in hover. The objective of the present study is to investigate the effects of the separation distances between rotors, and also fuselage and wings on the performance and efficiency of multirotor systems. Three-dimensional unsteady Navier-Stokes equations are solved using a spatially 5th order accurate scheme, dual-time stepping, and the Detached Eddy Simulation turbulence model. The results show that the separation distances as well as the wings have significant effects on the vertical forces of quadroror systems in hover. Understanding interactions in multi-rotor flows would help improve the design of next generation multi-rotor drones.

Multi-enzyme logic network architectures for assessing injuries: digital processing of biomarkers.

PubMed

Halámek, Jan; Bocharova, Vera; Chinnapareddy, Soujanya; Windmiller, Joshua Ray; Strack, Guinevere; Chuang, Min-Chieh; Zhou, Jian; Santhosh, Padmanabhan; Ramirez, Gabriela V; Arugula, Mary A; Wang, Joseph; Katz, Evgeny

2010-12-01

A multi-enzyme biocatalytic cascade processing simultaneously five biomarkers characteristic of traumatic brain injury (TBI) and soft tissue injury (STI) was developed. The system operates as a digital biosensor based on concerted function of 8 Boolean AND logic gates, resulting in the decision about the physiological conditions based on the logic analysis of complex patterns of the biomarkers. The system represents the first example of a multi-step/multi-enzyme biosensor with the built-in logic for the analysis of complex combinations of biochemical inputs. The approach is based on recent advances in enzyme-based biocomputing systems and the present paper demonstrates the potential applicability of biocomputing for developing novel digital biosensor networks.

(Semi-)Automated landform mapping of the alpine valley Gradental (Austria) based on LiDAR data

NASA Astrophysics Data System (ADS)

Strasser, T.; Eisank, C.

2012-04-01

Alpine valleys are typically characterised as complex, hierarchical structured systems with rapid landform changes. Detection of landform changes can be supported by automated geomorphological mapping. Especially, the analysis over short time scales require a method for standardised, unbiased geomorphological map reproduction, which is delivered by automated mapping techniques. In general, digital geomorphological mapping is a challenging task, since knowledge about landforms with respect to their natural boundaries as well as their hierarchical and scaling relationships, has to be integrated in an objective way. A combination of very-high spatial resolution data (VHSR) such as LiDAR and new methods like object based image analysis (OBIA) allow for a more standardised production of geomorphological maps. In OBIA the processing units are spatially configured objects that are created by multi-scale segmentation. Therefore, not only spectral information can be used for assigning the objects to geomorphological classes, but also spatial and topological properties can be exploited. In this study we focus on the detection of landforms, especially bedrock sediment deposits (alluvion, debris cone, talus, moraine, rockglacier), as well as glaciers. The study site Gradental [N 46°58'29.1"/ E 12°48'53.8"] is located in the Schobergruppe (Austria, Carinthia) and is characterised by heterogenic geology conditions and high process activity. The area is difficult to access and dominated by steep slopes, thus hindering a fast and detailed geomorphological field mapping. Landforms are identified using aerial and terrestrial LiDAR data (1 m spatial resolution). These DEMs are analysed by an object based hierarchical approach, which is structured in three main steps. The first step is to define occurring landforms by basic land surface parameters (LSPs), topology and hierarchy relations. Based on those definitions a semantic model is created. Secondly, a multi-scale segmentation is performed on a three-band LSP that integrates slope, aspect and plan curvature, which expresses the driving forces of geomorphological processes. In the third step, the generated multi-level object structures are classified in order to produce the geomorphological map. The classification rules are derived from the semantic model. Due to landform type-specific scale dependencies of LSPs, the values of LSPs used in the classification are calculated in a multi-scale manner by constantly enlarging the size of the moving window. In addition, object form properties (density, compactness, rectangular fit) are utilised as additional information for landform characterisation. Validation of classification is performed by intersecting a visually interpreted reference map with the classification output map and calculating accuracy matrices. Validation shows an overall accuracy of 78.25 % and a Kappa of 0.65. The natural borders of landforms can be easily detected by the use of slope, aspect and plan curvature. This study illustrates the potential of OBIA for a more standardised and automated mapping of surface units (landforms, landcover). Therefore, the presented methodology features a prospective automated geomorphological mapping approach for alpine regions.

Individualized Inservice Teacher Education (Project In-Step). Evaluation Report. Phase III.

ERIC Educational Resources Information Center

Thurber, John C.

This is a report on the third phase of Project IN-STEP, which was intended to develop a viable model for individualized, multi-media in-service teacher education programs. (Phase I and II are reported in ED 033 905, and ED 042 709). The rationale for Phase III was to see if the model could be successfully transferred to an area other than teaching…

Decision tree-based method for integrating gene expression, demographic, and clinical data to determine disease endotypes

PubMed Central

2013-01-01

Background Complex diseases are often difficult to diagnose, treat and study due to the multi-factorial nature of the underlying etiology. Large data sets are now widely available that can be used to define novel, mechanistically distinct disease subtypes (endotypes) in a completely data-driven manner. However, significant challenges exist with regard to how to segregate individuals into suitable subtypes of the disease and understand the distinct biological mechanisms of each when the goal is to maximize the discovery potential of these data sets. Results A multi-step decision tree-based method is described for defining endotypes based on gene expression, clinical covariates, and disease indicators using childhood asthma as a case study. We attempted to use alternative approaches such as the Student’s t-test, single data domain clustering and the Modk-prototypes algorithm, which incorporates multiple data domains into a single analysis and none performed as well as the novel multi-step decision tree method. This new method gave the best segregation of asthmatics and non-asthmatics, and it provides easy access to all genes and clinical covariates that distinguish the groups. Conclusions The multi-step decision tree method described here will lead to better understanding of complex disease in general by allowing purely data-driven disease endotypes to facilitate the discovery of new mechanisms underlying these diseases. This application should be considered a complement to ongoing efforts to better define and diagnose known endotypes. When coupled with existing methods developed to determine the genetics of gene expression, these methods provide a mechanism for linking genetics and exposomics data and thereby accounting for both major determinants of disease. PMID:24188919

Mechanisms of mononuclear phagocyte recruitment in Alzheimer's disease.

PubMed

Hickman, Suzanne E; El Khoury, Joseph

2010-04-01

Alzheimer's disease (AD) is associated with a significant neuroinflammatory component. Mononuclear phagocytes including monocytes and microglia are the principal cells involved, and they accumulate at perivascular sites of beta-amyloid (Abeta) deposition and in senile plaques. Recent evidence suggests that mononuclear phagocyte accumulation in the AD brain is dependent on chemokines. CCL2, a major monocyte chemokine, is upregulated in the AD brain. Interaction of CCL2 with its receptor CCR2 regulates mononuclear phagocyte accumulation in a mouse model of AD. CCR2 deficiency leads to lower mononuclear phagocyte accumulation and is associated with higher brain Abeta levels, specifically around blood vessels, suggesting that monocytes accumulate at sites of Abeta deposition in an initial attempt to clear these deposits and stop or delay their neurotoxic effects. Indeed, enhancing mononuclear phagocyte accumulation delays progression of AD. Here we review the mechanisms of mononuclear phagocyte accumulation in AD and discuss the potential roles of additional chemokines and their receptors in this process. We also propose a multi-step model for recruitment of mononuclear phagocytes into the brain. The first step involves egress of monocyte/microglial precursors from the bone marrow into the blood. The second step is crossing the blood-brain barrier to the perivascular areas and into the brain parenchyma. The final step includes movement of monocytes/microglia from areas of the brain that lack any amyloid deposition to senile plaques. Understanding the mechanism of recruitment of mononuclear phagocytes to the AD brain is necessary to further understand the role of these cells in the pathogenesis of AD and to identify any potential therapeutic use of these cells for the treatment of this disease.

Multi-criteria objective based climate change impact assessment for multi-purpose multi-reservoir systems

NASA Astrophysics Data System (ADS)

Müller, Ruben; Schütze, Niels

2014-05-01

Water resources systems with reservoirs are expected to be sensitive to climate change. Assessment studies that analyze the impact of climate change on the performance of reservoirs can be divided in two groups: (1) Studies that simulate the operation under projected inflows with the current set of operational rules. Due to non adapted operational rules the future performance of these reservoirs can be underestimated and the impact overestimated. (2) Studies that optimize the operational rules for best adaption of the system to the projected conditions before the assessment of the impact. The latter allows for estimating more realistically future performance and adaption strategies based on new operation rules are available if required. Multi-purpose reservoirs serve various, often conflicting functions. If all functions cannot be served simultaneously at a maximum level, an effective compromise between multiple objectives of the reservoir operation has to be provided. Yet under climate change the historically preferenced compromise may no longer be the most suitable compromise in the future. Therefore a multi-objective based climate change impact assessment approach for multi-purpose multi-reservoir systems is proposed in the study. Projected inflows are provided in a first step using a physically based rainfall-runoff model. In a second step, a time series model is applied to generate long-term inflow time series. Finally, the long-term inflow series are used as driving variables for a simulation-based multi-objective optimization of the reservoir system in order to derive optimal operation rules. As a result, the adapted Pareto-optimal set of diverse best compromise solutions can be presented to the decision maker in order to assist him in assessing climate change adaption measures with respect to the future performance of the multi-purpose reservoir system. The approach is tested on a multi-purpose multi-reservoir system in a mountainous catchment in Germany. A climate change assessment is performed for climate change scenarios based on the SRES emission scenarios A1B, B1 and A2 for a set of statistically downscaled meteorological data. The future performance of the multi-purpose multi-reservoir system is quantified and possible intensifications of trade-offs between management goals or reservoir utilizations are shown.

"Cast Your Net Widely": Three Steps to Expanding and Refining Your Problem before Action Learning Application

ERIC Educational Resources Information Center

Reese, Simon R.

2015-01-01

This paper reflects upon a three-step process to expand the problem definition in the early stages of an action learning project. The process created a community-powered problem-solving approach within the action learning context. The simple three steps expanded upon in the paper create independence, dependence, and inter-dependence to aid the…

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wemhoff, A P; Burnham, A K; Nichols III, A L

The reduction of the number of reactions in kinetic models for both the HMX beta-delta phase transition and thermal cookoff provides an attractive alternative to traditional multi-stage kinetic models due to reduced calibration effort requirements. In this study, we use the LLNL code ALE3D to provide calibrated kinetic parameters for a two-reaction bidirectional beta-delta HMX phase transition model based on Sandia Instrumented Thermal Ignition (SITI) and Scaled Thermal Explosion (STEX) temperature history curves, and a Prout-Tompkins cookoff model based on One-Dimensional Time to Explosion (ODTX) data. Results show that the two-reaction bidirectional beta-delta transition model presented here agrees as wellmore » with STEX and SITI temperature history curves as a reversible four-reaction Arrhenius model, yet requires an order of magnitude less computational effort. In addition, a single-reaction Prout-Tompkins model calibrated to ODTX data provides better agreement with ODTX data than a traditional multi-step Arrhenius model, and can contain up to 90% less chemistry-limited time steps for low-temperature ODTX simulations. Manual calibration methods for the Prout-Tompkins kinetics provide much better agreement with ODTX experimental data than parameters derived from Differential Scanning Calorimetry (DSC) measurements at atmospheric pressure. The predicted surface temperature at explosion for STEX cookoff simulations is a weak function of the cookoff model used, and a reduction of up to 15% of chemistry-limited time steps can be achieved by neglecting the beta-delta transition for this type of simulation. Finally, the inclusion of the beta-delta transition model in the overall kinetics model can affect the predicted time to explosion by 1% for the traditional multi-step Arrhenius approach, while up to 11% using a Prout-Tompkins cookoff model.« less

Military Personnel: Joint Officer Development Has Improved, But a Strategic Approach Is Needed. Report to the Subcommittee on Military Personnel, Committee on Armed Services, House of Representatives.

ERIC Educational Resources Information Center

General Accounting Office, Washington, DC.

In response to the need of military leaders to be better prepared to plan, support, and conduct joint (multi-service and multi-national) operations, Congress enacted the Goldwater- Nichols Department of Defense Reorganization Act of 1986. Positive steps were taken to implement provisions in the Act that address the education, assignment, and…

Are Physics-Based Simulators Ready for Prime Time? Comparisons of RSQSim with UCERF3 and Observations.

NASA Astrophysics Data System (ADS)

Milner, K. R.; Shaw, B. E.; Gilchrist, J. J.; Jordan, T. H.

2017-12-01

Probabilistic seismic hazard analysis (PSHA) is typically performed by combining an earthquake rupture forecast (ERF) with a set of empirical ground motion prediction equations (GMPEs). ERFs have typically relied on observed fault slip rates and scaling relationships to estimate the rate of large earthquakes on pre-defined fault segments, either ignoring or relying on expert opinion to set the rates of multi-fault or multi-segment ruptures. Version 3 of the Uniform California Earthquake Rupture Forecast (UCERF3) is a significant step forward, replacing expert opinion and fault segmentation with an inversion approach that matches observations better than prior models while incorporating multi-fault ruptures. UCERF3 is a statistical model, however, and doesn't incorporate the physics of earthquake nucleation, rupture propagation, and stress transfer. We examine the feasibility of replacing UCERF3, or components therein, with physics-based rupture simulators such as the Rate-State Earthquake Simulator (RSQSim), developed by Dieterich & Richards-Dinger (2010). RSQSim simulations on the UCERF3 fault system produce catalogs of seismicity that match long term rates on major faults, and produce remarkable agreement with UCERF3 when carried through to PSHA calculations. Averaged over a representative set of sites, the RSQSim-UCERF3 hazard-curve differences are comparable to the small differences between UCERF3 and its predecessor, UCERF2. The hazard-curve agreement between the empirical and physics-based models provides substantial support for the PSHA methodology. RSQSim catalogs include many complex multi-fault ruptures, which we compare with the UCERF3 rupture-plausibility metrics as well as recent observations. Complications in generating physically plausible kinematic descriptions of multi-fault ruptures have thus far prevented us from using UCERF3 in the CyberShake physics-based PSHA platform, which replaces GMPEs with deterministic ground motion simulations. RSQSim produces full slip/time histories that can be directly implemented as sources in CyberShake, without relying on the conditional hypocenter and slip distributions needed for the UCERF models. We also compare RSQSim with time-dependent PSHA calculations based on multi-fault renewal models.

Stability analysis of implicit time discretizations for the Compton-scattering Fokker-Planck equation

NASA Astrophysics Data System (ADS)

Densmore, Jeffery D.; Warsa, James S.; Lowrie, Robert B.; Morel, Jim E.

2009-09-01

The Fokker-Planck equation is a widely used approximation for modeling the Compton scattering of photons in high energy density applications. In this paper, we perform a stability analysis of three implicit time discretizations for the Compton-Scattering Fokker-Planck equation. Specifically, we examine (i) a Semi-Implicit (SI) scheme that employs backward-Euler differencing but evaluates temperature-dependent coefficients at their beginning-of-time-step values, (ii) a Fully Implicit (FI) discretization that instead evaluates temperature-dependent coefficients at their end-of-time-step values, and (iii) a Linearized Implicit (LI) scheme, which is developed by linearizing the temperature dependence of the FI discretization within each time step. Our stability analysis shows that the FI and LI schemes are unconditionally stable and cannot generate oscillatory solutions regardless of time-step size, whereas the SI discretization can suffer from instabilities and nonphysical oscillations for sufficiently large time steps. With the results of this analysis, we present time-step limits for the SI scheme that prevent undesirable behavior. We test the validity of our stability analysis and time-step limits with a set of numerical examples.

Application of the Multi-Doorway Continuum Shell Model to the Magnetic Dipole Strength Distribution in 58Ni

NASA Astrophysics Data System (ADS)

Spangenberger, H.; Beck, F.; Richter, A.

The usual continuum shell model is extended so as to include a statistical treatment of multi-doorway processes. The total configuration space of the nuclear reaction problem is subdivided into the primary doorway states which are coupled by the initial excitation to the nuclear ground state and the secondary doorway states which represent the complicated nature of multi-step reactions. The latter are evaluated within the exciton model which gives the coupling widths between the various finestructure subspaces. This coupling is determined by a statistical factor related to the exciton model and a dynamical factor given by the interaction matrix elements of the interacting excitons. The whole structure defines the multi-doorway continuum shell model. In this work it is applied to the highly fragmented magnetic dipole strength in 58Ni observed in high resolution electron scattering.Translated AbstractAnwendung des Multi-Doorway-Kontinuum-Schalenmodells auf die Verteilung der magnetischen Dipolstärke von 58NiDas Kontinuum-Schalenmodell wurde so erweitert, daß auch statistische Multi-Doorway-Prozesse berücksichtigt werden können. Hierzu wird der Konfigurationsraum unterteilt in den Raum der primären Doorway-Zustände, die direkt aus dem Grundzustand angeregt werden, und den der sekundären Doorway-Zustände, die die komplizierte Struktur der Multi-Step-Reaktionen repräsentieren. Während die primären Doorway-Zustände inclusive ihrer Anregungen mittels üblicher Schalenmodellmethoden beschrieben werden können, werden die sekundären Doorway-Zustände sowie ihre verschiedenen Kopplungen im Rahmen des Exciton-Modells behandelt. Diese Kopplungen sind durch einen aus dem Exciton-Modell resultierenden Faktor sowie durch einen dynamischen Faktor bestimmt, der sich aus dem Matrixelement der wechselwirkenden Excitonen berechnet. Die Struktur der Kopplungen definiert das Multi-Doorway-Kontinuum-Schalenmodell, das hier auf die Beschreibung der stark fragmentierten magnetischen Dipolstärke in 58Ni angewendet wird.

Cardiac imaging with multi-sector data acquisition in volumetric CT: variation of effective temporal resolution and its potential clinical consequences

NASA Astrophysics Data System (ADS)

Tang, Xiangyang; Hsieh, Jiang; Taha, Basel H.; Vass, Melissa L.; Seamans, John L.; Okerlund, Darin R.

2009-02-01

With increasing longitudinal detector dimension available in diagnostic volumetric CT, step-and-shoot scan is becoming popular for cardiac imaging. In comparison to helical scan, step-and-shoot scan decouples patient table movement from cardiac gating/triggering, which facilitates the cardiac imaging via multi-sector data acquisition, as well as the administration of inter-cycle heart beat variation (arrhythmia) and radiation dose efficiency. Ideally, a multi-sector data acquisition can improve temporal resolution at a factor the same as the number of sectors (best scenario). In reality, however, the effective temporal resolution is jointly determined by gantry rotation speed and patient heart beat rate, which may significantly lower than the ideal or no improvement (worst scenario). Hence, it is clinically relevant to investigate the behavior of effective temporal resolution in cardiac imaging with multi-sector data acquisition. In this study, a 5-second cine scan of a porcine heart, which cascades 6 porcine cardiac cycles, is acquired. In addition to theoretical analysis and motion phantom study, the clinical consequences due to the effective temporal resolution variation are evaluated qualitative or quantitatively. By employing a 2-sector image reconstruction strategy, a total of 15 (the permutation of P(6, 2)) cases between the best and worst scenarios are studied, providing informative guidance for the design and optimization of CT cardiac imaging in volumetric CT with multi-sector data acquisition.

Structural setting and kinematics of Nubian fault system, SE Western Desert, Egypt: An example of multi-reactivated intraplate strike-slip faults

NASA Astrophysics Data System (ADS)

Sakran, Shawky; Said, Said Mohamed

2018-02-01

Detailed surface geological mapping and subsurface seismic interpretation have been integrated to unravel the structural style and kinematic history of the Nubian Fault System (NFS). The NFS consists of several E-W Principal Deformation Zones (PDZs) (e.g. Kalabsha fault). Each PDZ is defined by spectacular E-W, WNW and ENE dextral strike-slip faults, NNE sinistral strike-slip faults, NE to ENE folds, and NNW normal faults. Each fault zone has typical self-similar strike-slip architecture comprising multi-scale fault segments. Several multi-scale uplifts and basins were developed at the step-over zones between parallel strike-slip fault segments as a result of local extension or contraction. The NNE faults consist of right-stepping sinistral strike-slip fault segments (e.g. Sin El Kiddab fault). The NNE sinistral faults extend for long distances ranging from 30 to 100 kms and cut one or two E-W PDZs. Two nearly perpendicular strike-slip tectonic regimes are recognized in the NFS; an inactive E-W Late Cretaceous - Early Cenozoic dextral transpression and an active NNE sinistral shear.

The multi-layer multi-configuration time-dependent Hartree method for bosons: theory, implementation, and applications.

PubMed

Cao, Lushuai; Krönke, Sven; Vendrell, Oriol; Schmelcher, Peter

2013-10-07

We develop the multi-layer multi-configuration time-dependent Hartree method for bosons (ML-MCTDHB), a variational numerically exact ab initio method for studying the quantum dynamics and stationary properties of general bosonic systems. ML-MCTDHB takes advantage of the permutation symmetry of identical bosons, which allows for investigations of the quantum dynamics from few to many-body systems. Moreover, the multi-layer feature enables ML-MCTDHB to describe mixed bosonic systems consisting of arbitrary many species. Multi-dimensional as well as mixed-dimensional systems can be accurately and efficiently simulated via the multi-layer expansion scheme. We provide a detailed account of the underlying theory and the corresponding implementation. We also demonstrate the superior performance by applying the method to the tunneling dynamics of bosonic ensembles in a one-dimensional double well potential, where a single-species bosonic ensemble of various correlation strengths and a weakly interacting two-species bosonic ensemble are considered.

Dependency graph for code analysis on emerging architectures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shashkov, Mikhail Jurievich; Lipnikov, Konstantin

Direct acyclic dependency (DAG) graph is becoming the standard for modern multi-physics codes.The ideal DAG is the true block-scheme of a multi-physics code. Therefore, it is the convenient object for insitu analysis of the cost of computations and algorithmic bottlenecks related to statistical frequent data motion and dymanical machine state.

Step edge sputtering yield at grazing incidence ion bombardment.

PubMed

Hansen, Henri; Polop, Celia; Michely, Thomas; Friedrich, Andreas; Urbassek, Herbert M

2004-06-18

The surface morphology of Pt(111) was investigated by scanning tunneling microscopy after 5 keV Ar+ ion bombardment at grazing incidence in dependence of the ion fluence and in the temperature range between 625 and 720 K. The average erosion rate was found to be strongly dependent on the ion fluence and the substrate temperature during bombardment. This dependence is traced back to the variation of step concentration with temperature and fluence. We develop a simple model allowing us to determine separately the constant sputtering yields for terraces and for impact area stripes in front of ascending steps. The experimentally determined yield of these stripes--the step-edge sputtering yield--is in excellent agreement with our molecular dynamics simulations performed for the experimental situation.

Structures to Resist the Effects of Accidental Explosions. Volume 3. Principles of Dynamic Analysis

DTIC Science & Technology

1984-06-01

multi-degree-of-freedom systems) is presented. A step-by-step numerical integration of an element’s motion under dynamic loads using the...structural arrangements; providing closures, and preventing damage to interior portions of structures due to structual motion , shock, and fragment...an element’s motion under dynamic loads utilizing the Acceleration-Impulse- Extrapolation Method or the Average Acceleration Method and design charts

Stepping Stones Triple P: The Theoretical Basis and Development of an Evidence-Based Positive Parenting Program for Families with a Child Who Has a Disability

ERIC Educational Resources Information Center

Sanders, Matthew; Mazzucchelli, Trevor; Studman, Lisa

2004-01-01

Stepping Stones Triple P is the first in a series of programs based on the Triple P--Positive Parenting Program that has been specifically designed for families who have a child with a disability. This paper presents the rationale, theoretical foundations, historical development and distinguishing features of the program. The multi-level…

Look and Feel: Haptic Interaction for Biomedicine

DTIC Science & Technology

1995-10-01

algorithm that is evaluated within the topology of the model. During each time step, forces are summed for each mobile atom based on external forces...volumetric properties; (b) conserving computation power by rendering media local to the interaction point; and (c) evaluating the simulation within...alteration of the model topology. Simulation of the DSM state is accomplished by a multi-step algorithm that is evaluated within the topology of the

Strategic disruption of nuclear pores structure, integrity and barrier for nuclear apoptosis.

PubMed

Shahin, Victor

2017-08-01

Apoptosis is a programmed cell death playing key roles in physiology and pathophysiology of multi cellular organisms. Its nuclear manifestation requires transmission of the death signals across the nuclear pore complexes (NPCs). In strategic sequential steps apoptotic factors disrupt NPCs structure, integrity and barrier ultimately leading to nuclear breakdown. The present review reflects on these steps. Copyright © 2017 Elsevier Ltd. All rights reserved.

A Lyapunov and Sacker–Sell spectral stability theory for one-step methods

DOE PAGES

Steyer, Andrew J.; Van Vleck, Erik S.

2018-04-13

Approximation theory for Lyapunov and Sacker–Sell spectra based upon QR techniques is used to analyze the stability of a one-step method solving a time-dependent (nonautonomous) linear ordinary differential equation (ODE) initial value problem in terms of the local error. Integral separation is used to characterize the conditioning of stability spectra calculations. The stability of the numerical solution by a one-step method of a nonautonomous linear ODE using real-valued, scalar, nonautonomous linear test equations is justified. This analysis is used to approximate exponential growth/decay rates on finite and infinite time intervals and establish global error bounds for one-step methods approximating uniformly,more » exponentially stable trajectories of nonautonomous and nonlinear ODEs. A time-dependent stiffness indicator and a one-step method that switches between explicit and implicit Runge–Kutta methods based upon time-dependent stiffness are developed based upon the theoretical results.« less

A Lyapunov and Sacker–Sell spectral stability theory for one-step methods

DOE Office of Scientific and Technical Information (OSTI.GOV)

Steyer, Andrew J.; Van Vleck, Erik S.

Approximation theory for Lyapunov and Sacker–Sell spectra based upon QR techniques is used to analyze the stability of a one-step method solving a time-dependent (nonautonomous) linear ordinary differential equation (ODE) initial value problem in terms of the local error. Integral separation is used to characterize the conditioning of stability spectra calculations. The stability of the numerical solution by a one-step method of a nonautonomous linear ODE using real-valued, scalar, nonautonomous linear test equations is justified. This analysis is used to approximate exponential growth/decay rates on finite and infinite time intervals and establish global error bounds for one-step methods approximating uniformly,more » exponentially stable trajectories of nonautonomous and nonlinear ODEs. A time-dependent stiffness indicator and a one-step method that switches between explicit and implicit Runge–Kutta methods based upon time-dependent stiffness are developed based upon the theoretical results.« less

Live single cell functional phenotyping in droplet nano-liter reactors

NASA Astrophysics Data System (ADS)

Konry, Tania; Golberg, Alexander; Yarmush, Martin

2013-11-01

While single cell heterogeneity is present in all biological systems, most studies cannot address it due to technical limitations. Here we describe a nano-liter droplet microfluidic-based approach for stimulation and monitoring of surfaceand secreted markers of live single immune dendritic cells (DCs) as well as monitoring the live T cell/DC interaction. This nano-liter in vivo simulating microenvironment allows delivering various stimuli reagents to each cell and appropriate gas exchanges which are necessary to ensure functionality and viability of encapsulated cells. Labeling bioassay and microsphere sensors were integrated into nano-liter reaction volume of the droplet to monitor live single cell surface markers and secretion analysis in the time-dependent fashion. Thus live cell stimulation, secretion and surface monitoring can be obtained simultaneously in distinct microenvironment, which previously was possible using complicated and multi-step in vitro and in vivo live-cell microscopy, together with immunological studies of the outcome secretion of cellular function.

SERS- and Electrochemically Active 3D Plasmonic Liquid Marbles for Molecular-Level Spectroelectrochemical Investigation of Microliter Reactions.

PubMed

Koh, Charlynn Sher Lin; Lee, Hiang Kwee; Phan-Quang, Gia Chuong; Han, Xuemei; Lee, Mian Rong; Yang, Zhe; Ling, Xing Yi

2017-07-17

Liquid marbles are emergent microreactors owing to their isolated environment and the flexibility of materials used. Plasmonic liquid marbles (PLMs) are demonstrated as the smallest spectroelectrochemical microliter-scale reactor for concurrent spectro- and electrochemical analyses. The three-dimensional Ag shell of PLMs are exploited as a bifunctional surface-enhanced Raman scattering (SERS) platform and working electrode for redox process modulation. The combination of SERS and electrochemistry (EC) capabilities enables in situ molecular read-out of transient electrochemical species, and elucidate the potential-dependent and multi-step reaction dynamics. The 3D configuration of our PLM-based EC-SERS system exhibits 2-fold and 10-fold superior electrochemical and SERS performance than conventional 2D platforms. The rich molecular-level electrochemical insights and excellent EC-SERS capabilities offered by our 3D spectroelectrochemical system are pertinent in charge transfer processes. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Inclusion dynamics in PC12 is comparable between amphetamines and MPTP.

PubMed

Gesi, Marco; Lazzeri, Gloria; Ferrucci, Michela; Pellegrini, Antonio; Lenzi, Paola; Ruggieri, Stefano; Fornai, Francesco; Paparelli, Antonio

2006-08-01

In previous studies it was demonstrated that amphetamine derivatives and 1-methyl article-4-phenylpyridinium produce neuronal cell bodies. In the present work, we compared the fine ultrastructure of the intracellular inclusions induced by these different neurotoxic treatments. In particular, we compared the dynamical changes occurring when a mild toxic stimulus acts for different time intervals. For this purpose, we exposed catecholamine-synthesizing PC12 cells to different amphetamine derivatives (methamphetamine and 3,4-methylenedioxymethamphetamine), or 1-methyl-4-phenylpyridinium ion, which represents the active metabolite of the neurotoxin 1-methyl-4-phenyl-1,3,4,6-tetrahydropyridine. Despite inclusions that are elicited by different mechanisms depending on the specific neurotoxin, their ultrastructural features are similar and there is a high parallelism in their temporal evolution. This suggests that formation of inclusions is a multi-step process that might be elicited by different stimuli and, once triggered, leads to the same final effect.

Integrated explosive preconcentrator and electrochemical detection system for 2,4,6-trinitrotoluene (TNT) vapor.

PubMed

Cizek, Karel; Prior, Chad; Thammakhet, Chongdee; Galik, Michal; Linker, Kevin; Tsui, Ray; Cagan, Avi; Wake, John; La Belle, Jeff; Wang, Joseph

2010-02-19

This article reports on an integrated explosive-preconcentration/electrochemical detection system for 2,4,6-trinitrotoluene (TNT) vapor. The challenges involved in such system integration are discussed. A hydrogel-coated screen-printed electrode is used for the detection of the thermally desorbed TNT from a preconcentration device using rapid square wave voltammetry. Optimization of the preconcentration system for desorption of TNT and subsequent electrochemical detection was conducted yielding a desorption temperature of 120 degrees C under a flow rate of 500 mL min(-1). Such conditions resulted in a characteristic electrochemical signal for TNT representing the multi-step reduction process. Quantitative measurements produced a linear signal dependence on TNT quantity exposed to the preconcentrator from 0.25 to 10 microg. Finally, the integrated device was successfully demonstrated using a sample of solid TNT located upstream of the preconcentrator. Copyright 2009 Elsevier B.V. All rights reserved.

Ignition improvement by injector arrangement in a multi-fuel combustor for micro gas turbine

NASA Astrophysics Data System (ADS)

Antoshkiv, O.; Poojitganont, T.; Jeansirisomboon, S.; Berg, H. P.

2018-01-01

The novel combustor design also has an impact on the ignitor arrangement. The conventional ignitor system cannot guarantee optimal ignition performance in the usual radial position. The difficult ignitability of gaseous fuels was the main challenge for the ignitor system improvement. One way to improve the ignition performance significantly is a torch ignitor system in which the gaseous fuel is directly mixed with a large amount of the combustor air. To reach this goal, the ignition process was investigated in detail. The micro gas turbine (MGT) ignition was optimised considering three main procedures: torch ignitor operation, burner ignition and flame propagation between the neighbour injectors. A successful final result of the chain of ignition procedures depends on multiple aspects of the combustor design. Performed development work shows an important step towards designing modern high-efficiency low-emission combustors.

Restarting and recentering genetic algorithm variations for DNA fragment assembly: The necessity of a multi-strategy approach.

PubMed

Hughes, James Alexander; Houghten, Sheridan; Ashlock, Daniel

2016-12-01

DNA Fragment assembly - an NP-Hard problem - is one of the major steps in of DNA sequencing. Multiple strategies have been used for this problem, including greedy graph-based algorithms, deBruijn graphs, and the overlap-layout-consensus approach. This study focuses on the overlap-layout-consensus approach. Heuristics and computational intelligence methods are combined to exploit their respective benefits. These algorithm combinations were able to produce high quality results surpassing the best results obtained by a number of competitive algorithms specially designed and tuned for this problem on thirteen of sixteen popular benchmarks. This work also reinforces the necessity of using multiple search strategies as it is clearly observed that algorithm performance is dependent on problem instance; without a deeper look into many searches, top solutions could be missed entirely. Copyright © 2016. Published by Elsevier Ireland Ltd.

Structure and Function of the Mind bomb E3 ligase in the context of Notch Signal Transduction

PubMed Central

Guo, Bingqian; McMillan, Brian J.; Blacklow, Stephen C.

2016-01-01

The Notch signaling pathway has a critical role in cell fate determination and tissue homeostasis in a variety of different lineages. In the context of normal Notch signaling, the Notch receptor of the “signal-receiving” cell is activated in trans by a Notch ligand from a neighboring “signal-sending” cell. Genetic studies in several model organisms have established that ubiquitination of the Notch ligand, and its regulated endocytosis, is essential for transmission of this activation signal. In mammals, this ubiquitination step is dependent on the protein Mind bomb 1 (Mib1), a large multi-domain RING-type E3 ligase, and its direct interaction with the intracellular tails of Notch ligand molecules. Here, we discuss our current understanding of Mind bomb structure and mechanism in the context of Notch signaling and beyond. PMID:27285058

A conserved Mediator–CDK8 kinase module association regulates Mediator–RNA polymerase II interaction

PubMed Central

Tsai, Kuang-Lei; Sato, Shigeo; Tomomori-Sato, Chieri; Conaway, Ronald C.; Conaway, Joan W.; Asturias, Francisco J.

2013-01-01

The CDK8 kinase module (CKM) is a conserved, dissociable Mediator subcomplex whose component subunits were genetically linked to the RNA polymerase II (RNAPII) carboxy-terminal domain (CTD) and individually recognized as transcriptional repressors before Mediator was identified as a preeminent complex in eukaryotic transcription regulation. We used macromolecular electron microscopy and biochemistry to investigate the subunit organization, structure, and Mediator interaction of the Saccharomyces cerevisiae CKM. We found that interaction of the CKM with Mediator’s Middle module interferes with CTD-dependent RNAPII binding to a previously unknown Middle module CTD-binding site targeted early on in a multi-step holoenzyme formation process. Taken together, our results reveal the basis for CKM repression, clarify the origin of the connection between CKM subunits and the CTD, and suggest that a combination of competitive interactions and conformational changes that facilitate holoenzyme formation underlie the Mediator mechanism. PMID:23563140

Hot Fusion: an efficient method to clone multiple DNA fragments as well as inverted repeats without ligase.

PubMed

Fu, Changlin; Donovan, William P; Shikapwashya-Hasser, Olga; Ye, Xudong; Cole, Robert H

2014-01-01

Molecular cloning is utilized in nearly every facet of biological and medical research. We have developed a method, termed Hot Fusion, to efficiently clone one or multiple DNA fragments into plasmid vectors without the use of ligase. The method is directional, produces seamless junctions and is not dependent on the availability of restriction sites for inserts. Fragments are assembled based on shared homology regions of 17-30 bp at the junctions, which greatly simplifies the construct design. Hot Fusion is carried out in a one-step, single tube reaction at 50 °C for one hour followed by cooling to room temperature. In addition to its utility for multi-fragment assembly Hot Fusion provides a highly efficient method for cloning DNA fragments containing inverted repeats for applications such as RNAi. The overall cloning efficiency is in the order of 90-95%.

Hot Fusion: An Efficient Method to Clone Multiple DNA Fragments as Well as Inverted Repeats without Ligase

PubMed Central

Fu, Changlin; Donovan, William P.; Shikapwashya-Hasser, Olga; Ye, Xudong; Cole, Robert H.

2014-01-01

Molecular cloning is utilized in nearly every facet of biological and medical research. We have developed a method, termed Hot Fusion, to efficiently clone one or multiple DNA fragments into plasmid vectors without the use of ligase. The method is directional, produces seamless junctions and is not dependent on the availability of restriction sites for inserts. Fragments are assembled based on shared homology regions of 17–30 bp at the junctions, which greatly simplifies the construct design. Hot Fusion is carried out in a one-step, single tube reaction at 50°C for one hour followed by cooling to room temperature. In addition to its utility for multi-fragment assembly Hot Fusion provides a highly efficient method for cloning DNA fragments containing inverted repeats for applications such as RNAi. The overall cloning efficiency is in the order of 90–95%. PMID:25551825

Proximity correction of high-dosed frame with PROXECCO

NASA Astrophysics Data System (ADS)

Eisenmann, Hans; Waas, Thomas; Hartmann, Hans

1994-05-01

Usefulness of electron beam lithography is strongly related to the efficiency and quality of methods used for proximity correction. This paper addresses the above issue by proposing an extension to the new proximity correction program PROXECCO. The combination of a framing step with PROXECCO produces a pattern with a very high edge accuracy and still allows usage of the fast correction procedure. Making a frame with a higher dose imitates a fine resolution correction where the coarse part is disregarded. So after handling the high resolution effect by means of framing, an additional coarse correction is still needed. Higher doses have a higher contribution to the proximity effect. This additional proximity effect is taken into account with the help of the multi-dose input of PROXECCO. The dose of the frame is variable, depending on the deposited energy coming from backscattering of the proximity. Simulation proves the very high edge accuracy of the applied method.

Non-Gaussian Analysis of Turbulent Boundary Layer Fluctuating Pressure on Aircraft Skin Panels

NASA Technical Reports Server (NTRS)

Rizzi, Stephen A.; Steinwolf, Alexander

2005-01-01

The purpose of the study is to investigate the probability density function (PDF) of turbulent boundary layer fluctuating pressures measured on the outer sidewall of a supersonic transport aircraft and to approximate these PDFs by analytical models. Experimental flight results show that the fluctuating pressure PDFs differ from the Gaussian distribution even for standard smooth surface conditions. The PDF tails are wider and longer than those of the Gaussian model. For pressure fluctuations in front of forward-facing step discontinuities, deviations from the Gaussian model are more significant and the PDFs become asymmetrical. There is a certain spatial pattern of the skewness and kurtosis behavior depending on the distance upstream from the step. All characteristics related to non-Gaussian behavior are highly dependent upon the distance from the step and the step height, less dependent on aircraft speed, and not dependent on the fuselage location. A Hermite polynomial transform model and a piecewise-Gaussian model fit the flight data well both for the smooth and stepped conditions. The piecewise-Gaussian approximation can be additionally regarded for convenience in usage after the model is constructed.

Incorporating evolution of transcription factor binding sites into annotated alignments.

PubMed

Bais, Abha S; Grossmann, Stefen; Vingron, Martin

2007-08-01

Identifying transcription factor binding sites (TFBSs) is essential to elucidate putative regulatory mechanisms. A common strategy is to combine cross-species conservation with single sequence TFBS annotation to yield "conserved TFBSs". Most current methods in this field adopt a multi-step approach that segregates the two aspects. Again, it is widely accepted that the evolutionary dynamics of binding sites differ from those of the surrounding sequence. Hence, it is desirable to have an approach that explicitly takes this factor into account. Although a plethora of approaches have been proposed for the prediction of conserved TFBSs, very few explicitly model TFBS evolutionary properties, while additionally being multi-step. Recently, we introduced a novel approach to simultaneously align and annotate conserved TFBSs in a pair of sequences. Building upon the standard Smith-Waterman algorithm for local alignments, SimAnn introduces additional states for profiles to output extended alignments or annotated alignments. That is, alignments with parts annotated as gaplessly aligned TFBSs (pair-profile hits)are generated. Moreover,the pair- profile related parameters are derived in a sound statistical framework. In this article, we extend this approach to explicitly incorporate evolution of binding sites in the SimAnn framework. We demonstrate the extension in the theoretical derivations through two position-specific evolutionary models, previously used for modelling TFBS evolution. In a simulated setting, we provide a proof of concept that the approach works given the underlying assumptions,as compared to the original work. Finally, using a real dataset of experimentally verified binding sites in human-mouse sequence pairs,we compare the new approach (eSimAnn) to an existing multi-step tool that also considers TFBS evolution. Although it is widely accepted that binding sites evolve differently from the surrounding sequences, most comparative TFBS identification methods do not explicitly consider this.Additionally, prediction of conserved binding sites is carried out in a multi-step approach that segregates alignment from TFBS annotation. In this paper, we demonstrate how the simultaneous alignment and annotation approach of SimAnn can be further extended to incorporate TFBS evolutionary relationships. We study how alignments and binding site predictions interplay at varying evolutionary distances and for various profile qualities.

Multi-instrument assessment of physical activity in female office workers.

PubMed

Can, Sema; Gündüz, Nevin; Arslan, Erşan; Biernat, Elżbieta; Ersöz, Gülfem; Kilit, Bülent

2016-11-18

The aim of this study was to examine the multi-instrument assessment of physical activity in female office workers. Fifty healthy women (age (mean ± standard deviation): 34.8±5.9 years, body height: 158±0.4 cm, body weight: 61.8±7.5 kg, body mass index: 24.6±2.7 kg/m²) workers from the same workplace volunteered to participate in the study. Physical activity was measured with the 7-day Physical Activity Assessment Questionnaire (7-d PAAQ), an objective multi-sensor armband tool, and also a waist-mounted pedometer, which were both worn for 7 days. A significant correlation between step numbers measured by armband and pedometer was observed (r = 0.735), but the step numbers measured by these 2 methods were significantly different (10 941±2236 steps/ day and 9170±2377 steps/day, respectively; p < 0.001). There was a weak correlation between the value of 7-d PAAQ total energy expenditure and the value of armband total energy expenditure (r = 0.394, p = 0.005). However, total energy expenditure values measured by armband and 7-d PAAQ were not significantly different (2081±370 kcal/ day and 2084±197 kcal/day, respectively; p = 0.96). In addition, physical activity levels (average daily metabolic equivalents (MET)) measured by armband and 7-d PAAQ were not significantly different (1.45±0.12 MET/day and 1.47±0.24 MET/day, respectively; p = 0.44). The results of this study showed that the correlation between pedometer and armband measurements was higher than that between armband measurements and 7-d PAAQ selfreports. Our results suggest that none of the assessment methods examined here, 7-d PAAQ, pedometer, or armband, is sufficient when used as a single tool for physical activity level determination. Therefore, multi-instrument assessment methods are preferable. Int J Occup Med Environ Health 2016;29(6):937-945. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

Multi-shape active composites by 3D printing of digital shape memory polymers

NASA Astrophysics Data System (ADS)

Wu, Jiangtao; Yuan, Chao; Ding, Zhen; Isakov, Michael; Mao, Yiqi; Wang, Tiejun; Dunn, Martin L.; Qi, H. Jerry

2016-04-01

Recent research using 3D printing to create active structures has added an exciting new dimension to 3D printing technology. After being printed, these active, often composite, materials can change their shape over time; this has been termed as 4D printing. In this paper, we demonstrate the design and manufacture of active composites that can take multiple shapes, depending on the environmental temperature. This is achieved by 3D printing layered composite structures with multiple families of shape memory polymer (SMP) fibers - digital SMPs - with different glass transition temperatures (Tg) to control the transformation of the structure. After a simple single-step thermomechanical programming process, the fiber families can be sequentially activated to bend when the temperature is increased. By tuning the volume fraction of the fibers, bending deformation can be controlled. We develop a theoretical model to predict the deformation behavior for better understanding the phenomena and aiding the design. We also design and print several flat 2D structures that can be programmed to fold and open themselves when subjected to heat. With the advantages of an easy fabrication process and the controllable multi-shape memory effect, the printed SMP composites have a great potential in 4D printing applications.

Multi-shape active composites by 3D printing of digital shape memory polymers.

PubMed

Wu, Jiangtao; Yuan, Chao; Ding, Zhen; Isakov, Michael; Mao, Yiqi; Wang, Tiejun; Dunn, Martin L; Qi, H Jerry

2016-04-13

Recent research using 3D printing to create active structures has added an exciting new dimension to 3D printing technology. After being printed, these active, often composite, materials can change their shape over time; this has been termed as 4D printing. In this paper, we demonstrate the design and manufacture of active composites that can take multiple shapes, depending on the environmental temperature. This is achieved by 3D printing layered composite structures with multiple families of shape memory polymer (SMP) fibers - digital SMPs - with different glass transition temperatures (Tg) to control the transformation of the structure. After a simple single-step thermomechanical programming process, the fiber families can be sequentially activated to bend when the temperature is increased. By tuning the volume fraction of the fibers, bending deformation can be controlled. We develop a theoretical model to predict the deformation behavior for better understanding the phenomena and aiding the design. We also design and print several flat 2D structures that can be programmed to fold and open themselves when subjected to heat. With the advantages of an easy fabrication process and the controllable multi-shape memory effect, the printed SMP composites have a great potential in 4D printing applications.

Multi-shape active composites by 3D printing of digital shape memory polymers

PubMed Central

Wu, Jiangtao; Yuan, Chao; Ding, Zhen; Isakov, Michael; Mao, Yiqi; Wang, Tiejun; Dunn, Martin L.; Qi, H. Jerry

2016-01-01

Recent research using 3D printing to create active structures has added an exciting new dimension to 3D printing technology. After being printed, these active, often composite, materials can change their shape over time; this has been termed as 4D printing. In this paper, we demonstrate the design and manufacture of active composites that can take multiple shapes, depending on the environmental temperature. This is achieved by 3D printing layered composite structures with multiple families of shape memory polymer (SMP) fibers – digital SMPs - with different glass transition temperatures (Tg) to control the transformation of the structure. After a simple single-step thermomechanical programming process, the fiber families can be sequentially activated to bend when the temperature is increased. By tuning the volume fraction of the fibers, bending deformation can be controlled. We develop a theoretical model to predict the deformation behavior for better understanding the phenomena and aiding the design. We also design and print several flat 2D structures that can be programmed to fold and open themselves when subjected to heat. With the advantages of an easy fabrication process and the controllable multi-shape memory effect, the printed SMP composites have a great potential in 4D printing applications. PMID:27071543

Penalized spline estimation for functional coefficient regression models.

PubMed

Cao, Yanrong; Lin, Haiqun; Wu, Tracy Z; Yu, Yan

2010-04-01

The functional coefficient regression models assume that the regression coefficients vary with some "threshold" variable, providing appreciable flexibility in capturing the underlying dynamics in data and avoiding the so-called "curse of dimensionality" in multivariate nonparametric estimation. We first investigate the estimation, inference, and forecasting for the functional coefficient regression models with dependent observations via penalized splines. The P-spline approach, as a direct ridge regression shrinkage type global smoothing method, is computationally efficient and stable. With established fixed-knot asymptotics, inference is readily available. Exact inference can be obtained for fixed smoothing parameter λ, which is most appealing for finite samples. Our penalized spline approach gives an explicit model expression, which also enables multi-step-ahead forecasting via simulations. Furthermore, we examine different methods of choosing the important smoothing parameter λ: modified multi-fold cross-validation (MCV), generalized cross-validation (GCV), and an extension of empirical bias bandwidth selection (EBBS) to P-splines. In addition, we implement smoothing parameter selection using mixed model framework through restricted maximum likelihood (REML) for P-spline functional coefficient regression models with independent observations. The P-spline approach also easily allows different smoothness for different functional coefficients, which is enabled by assigning different penalty λ accordingly. We demonstrate the proposed approach by both simulation examples and a real data application.

Early and Late Damages in Chromosome 3 of Human Lymphocytes After Radiation Exposure

NASA Technical Reports Server (NTRS)

Sunagawa, Mayumi; Mangala, Lingegowda; Zhang, Ye; Kahdim, Munira; Wilson, Bobby; Cucinotta, Francis A.; Wu, Honglu

2011-01-01

Tumor formation in humans or animals is a multi-step process. An early stage of cancer development is believed to be genomic instability (GI) which accelerates the mutation rate in the descendants of the cells surviving radiation exposure. GI is defined as elevated or persistent genetic damages occurring many generations after the cells are exposed. While early studies have demonstrated radiation-induced GI in several cell types as detected in endpoints such as mutation, apoptosis and damages in chromosomes, the dependence of GI on the quality of radiation remains uncertain. To investigate GI in human lymphocytes induced by both low- and high-LET radiation, we initially exposed white blood cells collected from healthy subjects to gamma rays in vitro, and cultured the cells for multiple generations. Chromosome aberrations were analyzed in cells collected at first mitosis post irradiation and at several intervals during the culture period. Among a number of biological endpoints planned for the project, the multi-color banding fluorescent in situ hybridization (mBAND) allows identification of inversions that were expected to be stable. We present here early and late chromosome aberrations detected with mBAND in chromosome 3 after gamma exposure. Comparison of chromosome damages in between human lymphocytes and human epithelial cells is also discussed

Multi-scale simulation of quantum dot formation in Al/Al (110) homoepitaxy

NASA Astrophysics Data System (ADS)

Tiwary, Yogesh; Fichthorn, Kristen

2007-03-01

In experimental studies of Al(110) homoepitaxy, it is observed that over a certain temperature window (330-500K), 3D huts, up to 50 nm high with well defined and smooth (111) and (100) facets, form and self-organize over the micron scale [1]. The factors leading to this kinetic self-organization are currently unclear. To understand how these structures form and evolve, we simulated multi-layer, homoepitaxial growth on Al(110) using ab initio kinetic Monte Carlo (KMC). At the high temperatures, where nano-huts form, the KMC simulations are slow. To tackle this problem, we use a technique developed by Devita & Sander [2], in which isolated adatoms make multiple moves in one step. We achieve high efficiency with this algorithm and we explore very high temperatures on large simulation lattices. We uncover a variety of interesting morphologies (Ripples, mounds, smooth surface, huts) that depend on the growth temperature. By varying the barriers for various rate processes, we discern the factors that determine hut sizes, aspect ratios, and self-organization. [1] F. Buatier de Mongeot, W. Zhu, A. Molle, R. Buzio, C. Boragno, U. Valbusa, E. Wang, and Z. Zhang, Phys. Rev. Lett. 91, 016102 (2003). [2] J.P. Devita & L.M. Sander, Phys. Rev. B 72, 205421 (2005).

Biomimetic surface structuring using cylindrical vector femtosecond laser beams

PubMed Central

Skoulas, Evangelos; Manousaki, Alexandra; Fotakis, Costas; Stratakis, Emmanuel

2017-01-01

We report on a new, single-step and scalable method to fabricate highly ordered, multi-directional and complex surface structures that mimic the unique morphological features of certain species found in nature. Biomimetic surface structuring was realized by exploiting the unique and versatile angular profile and the electric field symmetry of cylindrical vector (CV) femtosecond (fs) laser beams. It is shown that, highly controllable, periodic structures exhibiting sizes at nano-, micro- and dual- micro/nano scales can be directly written on Ni upon line and large area scanning with radial and azimuthal polarization beams. Depending on the irradiation conditions, new complex multi-directional nanostructures, inspired by the Shark’s skin morphology, as well as superhydrophobic dual-scale structures mimicking the Lotus’ leaf water repellent properties can be attained. It is concluded that the versatility and features variations of structures formed is by far superior to those obtained via laser processing with linearly polarized beams. More important, by exploiting the capabilities offered by fs CV fields, the present technique can be further extended to fabricate even more complex and unconventional structures. We believe that our approach provides a new concept in laser materials processing, which can be further exploited for expanding the breadth and novelty of applications. PMID:28327611

Towards more reliable automated multi-dose dispensing: retrospective follow-up study on medication dose errors and product defects.

PubMed

Palttala, Iida; Heinämäki, Jyrki; Honkanen, Outi; Suominen, Risto; Antikainen, Osmo; Hirvonen, Jouni; Yliruusi, Jouko

2013-03-01

To date, little is known on applicability of different types of pharmaceutical dosage forms in an automated high-speed multi-dose dispensing process. The purpose of the present study was to identify and further investigate various process-induced and/or product-related limitations associated with multi-dose dispensing process. The rates of product defects and dose dispensing errors in automated multi-dose dispensing were retrospectively investigated during a 6-months follow-up period. The study was based on the analysis of process data of totally nine automated high-speed multi-dose dispensing systems. Special attention was paid to the dependence of multi-dose dispensing errors/product defects and pharmaceutical tablet properties (such as shape, dimensions, weight, scored lines, coatings, etc.) to profile the most suitable forms of tablets for automated dose dispensing systems. The relationship between the risk of errors in dose dispensing and tablet characteristics were visualized by creating a principal component analysis (PCA) model for the outcome of dispensed tablets. The two most common process-induced failures identified in the multi-dose dispensing are predisposal of tablet defects and unexpected product transitions in the medication cassette (dose dispensing error). The tablet defects are product-dependent failures, while the tablet transitions are dependent on automated multi-dose dispensing systems used. The occurrence of tablet defects is approximately twice as common as tablet transitions. Optimal tablet preparation for the high-speed multi-dose dispensing would be a round-shaped, relatively small/middle-sized, film-coated tablet without any scored line. Commercial tablet products can be profiled and classified based on their suitability to a high-speed multi-dose dispensing process.

Advanced real-time multi-display educational system (ARMES): An innovative real-time audiovisual mentoring tool for complex robotic surgery.

PubMed

Lee, Joong Ho; Tanaka, Eiji; Woo, Yanghee; Ali, Güner; Son, Taeil; Kim, Hyoung-Il; Hyung, Woo Jin

2017-12-01

The recent scientific and technologic advances have profoundly affected the training of surgeons worldwide. We describe a novel intraoperative real-time training module, the Advanced Robotic Multi-display Educational System (ARMES). We created a real-time training module, which can provide a standardized step by step guidance to robotic distal subtotal gastrectomy with D2 lymphadenectomy procedures, ARMES. The short video clips of 20 key steps in the standardized procedure for robotic gastrectomy were created and integrated with TilePro™ software to delivery on da Vinci Surgical Systems (Intuitive Surgical, Sunnyvale, CA). We successfully performed the robotic distal subtotal gastrectomy with D2 lymphadenectomy for patient with gastric cancer employing this new teaching method without any transfer errors or system failures. Using this technique, the total operative time was 197 min and blood loss was 50 mL and there were no intra- or post-operative complications. Our innovative real-time mentoring module, ARMES, enables standardized, systematic guidance during surgical procedures. © 2017 Wiley Periodicals, Inc.

A comparative theoretical study of the catalytic activities of Au2(-) and AuAg(-) dimers for CO oxidation.

PubMed

Liu, Peng; Song, Ke; Zhang, Dongju; Liu, Chengbu

2012-05-01

The detailed mechanisms of catalytic CO oxidation over Au(2)(-) and AuAg(-) dimers, which represent the simplest models for monometal Au and bimetallic Au-Ag nanoparticles, have been studied by performing density functional theory calculations. It is found that both Au(2)(-) and AuAg(-) dimers catalyze the reaction according to the similar mono-center Eley-Rideal mechanism. The catalytic reaction is of the multi-channel and multi-step characteristic, which can proceed along four possible pathways via two or three elementary steps. In AuAg(-), the Au site is more active than the Ag site, and the calculated energy barrier values for the rate-determining step of the Au-site catalytic reaction are remarkably smaller than those for both the Ag-site catalytic reaction and the Au(2)(-) catalytic reaction. The better catalytic activity of bimetallic AuAg(-) dimer is attributed to the synergistic effect between Au and Ag atom. The present results provide valuable information for understanding the higher catalytic activity of Au-Ag nanoparticles and nanoalloys for low-temperature CO oxidation than either pure metallic catalyst.

A Multi-Scale, Multi-Physics Optimization Framework for Additively Manufactured Structural Components

NASA Astrophysics Data System (ADS)

El-Wardany, Tahany; Lynch, Mathew; Gu, Wenjiong; Hsu, Arthur; Klecka, Michael; Nardi, Aaron; Viens, Daniel

This paper proposes an optimization framework enabling the integration of multi-scale / multi-physics simulation codes to perform structural optimization design for additively manufactured components. Cold spray was selected as the additive manufacturing (AM) process and its constraints were identified and included in the optimization scheme. The developed framework first utilizes topology optimization to maximize stiffness for conceptual design. The subsequent step applies shape optimization to refine the design for stress-life fatigue. The component weight was reduced by 20% while stresses were reduced by 75% and the rigidity was improved by 37%. The framework and analysis codes were implemented using Altair software as well as an in-house loading code. The optimized design was subsequently produced by the cold spray process.

Multi-frame partially saturated images blind deconvolution

NASA Astrophysics Data System (ADS)

Ye, Pengzhao; Feng, Huajun; Xu, Zhihai; Li, Qi; Chen, Yueting

2016-12-01

When blurred images have saturated or over-exposed pixels, conventional blind deconvolution approaches often fail to estimate accurate point spread function (PSF) and will introduce local ringing artifacts. In this paper, we propose a method to deal with the problem under the modified multi-frame blind deconvolution framework. First, in the kernel estimation step, a light streak detection scheme using multi-frame blurred images is incorporated into the regularization constraint. Second, we deal with image regions affected by the saturated pixels separately by modeling a weighted matrix during each multi-frame deconvolution iteration process. Both synthetic and real-world examples show that more accurate PSFs can be estimated and restored images have richer details and less negative effects compared to state of art methods.

The Impact of Alcoholics Anonymous on other substance abuse related Twelve Step programs

PubMed Central

Laudet, Alexandre B.

2008-01-01

This chapter explores the influence of the AA model on self-help fellowships addressing problems of drug dependence. Fellowships that have adapted the 12-step recovery model to other substances of abuse are reviewed; next similarities and differences between AA and drug-recovery 12-step organizations are examined; finally, we present empirical findings on patterns of attendance and perceptions of AA and Narcotics Anonymous (NA) among polydrug dependent populations, many of whom are cross-addicted to alcohol. Future directions in 12-step research are noted in closing. PMID:19115764

Slip Continuity in Explicit Crystal Plasticity Simulations Using Nonlocal Continuum and Semi-discrete Approaches

DTIC Science & Technology

2013-01-01

Based Micropolar Single Crystal Plasticity: Comparison of Multi - and Single Criterion Theories. J. Mech. Phys. Solids 2011, 59, 398–422. ALE3D ...element boundaries in a multi -step constitutive evaluation (Becker, 2011). The results showed the desired effects of smoothing the deformation field...Implementation The model was implemented in the large-scale parallel, explicit finite element code ALE3D (2012). The crystal plasticity

Combined Economic and Hydrologic Modeling to Support Collaborative Decision Making Processes

NASA Astrophysics Data System (ADS)

Sheer, D. P.

2008-12-01

For more than a decade, the core concept of the author's efforts in support of collaborative decision making has been a combination of hydrologic simulation and multi-objective optimization. The modeling has generally been used to support collaborative decision making processes. The OASIS model developed by HydroLogics Inc. solves a multi-objective optimization at each time step using a mixed integer linear program (MILP). The MILP can be configured to include any user defined objective, including but not limited too economic objectives. For example, an estimated marginal value for water for crops and M&I use were included in the objective function to drive trades in a model of the lower Rio Grande. The formulation of the MILP, constraints and objectives, in any time step is conditional: it changes based on the value of state variables and dynamic external forcing functions, such as rainfall, hydrology, market prices, arrival of migratory fish, water temperature, etc. It therefore acts as a dynamic short term multi-objective economic optimization for each time step. MILP is capable of solving a general problem that includes a very realistic representation of the physical system characteristics in addition to the normal multi-objective optimization objectives and constraints included in economic models. In all of these models, the short term objective function is a surrogate for achieving long term multi-objective results. The long term performance for any alternative (especially including operating strategies) is evaluated by simulation. An operating rule is the combination of conditions, parameters, constraints and objectives used to determine the formulation of the short term optimization in each time step. Heuristic wrappers for the simulation program have been developed improve the parameters of an operating rule, and are initiating research on a wrapper that will allow us to employ a genetic algorithm to improve the form of the rule (conditions, constraints, and short term objectives) as well. In the models operating rules represent different models of human behavior, and the objective of the modeling is to find rules for human behavior that perform well in terms of long term human objectives. The conceptual model used to represent human behavior incorporates economic multi-objective optimization for surrogate objectives, and rules that set those objectives based on current conditions and accounting for uncertainty, at least implicitly. The author asserts that real world operating rules follow this form and have evolved because they have been perceived as successful in the past. Thus, the modeling efforts focus on human behavior in much the same way that economic models focus on human behavior. This paper illustrates the above concepts with real world examples.

GPU accelerated population annealing algorithm

NASA Astrophysics Data System (ADS)

Barash, Lev Yu.; Weigel, Martin; Borovský, Michal; Janke, Wolfhard; Shchur, Lev N.

2017-11-01

Population annealing is a promising recent approach for Monte Carlo simulations in statistical physics, in particular for the simulation of systems with complex free-energy landscapes. It is a hybrid method, combining importance sampling through Markov chains with elements of sequential Monte Carlo in the form of population control. While it appears to provide algorithmic capabilities for the simulation of such systems that are roughly comparable to those of more established approaches such as parallel tempering, it is intrinsically much more suitable for massively parallel computing. Here, we tap into this structural advantage and present a highly optimized implementation of the population annealing algorithm on GPUs that promises speed-ups of several orders of magnitude as compared to a serial implementation on CPUs. While the sample code is for simulations of the 2D ferromagnetic Ising model, it should be easily adapted for simulations of other spin models, including disordered systems. Our code includes implementations of some advanced algorithmic features that have only recently been suggested, namely the automatic adaptation of temperature steps and a multi-histogram analysis of the data at different temperatures. Program Files doi:http://dx.doi.org/10.17632/sgzt4b7b3m.1 Licensing provisions: Creative Commons Attribution license (CC BY 4.0) Programming language: C, CUDA External routines/libraries: NVIDIA CUDA Toolkit 6.5 or newer Nature of problem: The program calculates the internal energy, specific heat, several magnetization moments, entropy and free energy of the 2D Ising model on square lattices of edge length L with periodic boundary conditions as a function of inverse temperature β. Solution method: The code uses population annealing, a hybrid method combining Markov chain updates with population control. The code is implemented for NVIDIA GPUs using the CUDA language and employs advanced techniques such as multi-spin coding, adaptive temperature steps and multi-histogram reweighting. Additional comments: Code repository at https://github.com/LevBarash/PAising. The system size and size of the population of replicas are limited depending on the memory of the GPU device used. For the default parameter values used in the sample programs, L = 64, θ = 100, β0 = 0, βf = 1, Δβ = 0 . 005, R = 20 000, a typical run time on an NVIDIA Tesla K80 GPU is 151 seconds for the single spin coded (SSC) and 17 seconds for the multi-spin coded (MSC) program (see Section 2 for a description of these parameters).

Label-aligned Multi-task Feature Learning for Multimodal Classification of Alzheimer’s Disease and Mild Cognitive Impairment

PubMed Central

Zu, Chen; Jie, Biao; Liu, Mingxia; Chen, Songcan

2015-01-01

Multimodal classification methods using different modalities of imaging and non-imaging data have recently shown great advantages over traditional single-modality-based ones for diagnosis and prognosis of Alzheimer’s disease (AD), as well as its prodromal stage, i.e., mild cognitive impairment (MCI). However, to the best of our knowledge, most existing methods focus on mining the relationship across multiple modalities of the same subjects, while ignoring the potentially useful relationship across different subjects. Accordingly, in this paper, we propose a novel learning method for multimodal classification of AD/MCI, by fully exploring the relationships across both modalities and subjects. Specifically, our proposed method includes two subsequent components, i.e., label-aligned multi-task feature selection and multimodal classification. In the first step, the feature selection learning from multiple modalities are treated as different learning tasks and a group sparsity regularizer is imposed to jointly select a subset of relevant features. Furthermore, to utilize the discriminative information among labeled subjects, a new label-aligned regularization term is added into the objective function of standard multi-task feature selection, where label-alignment means that all multi-modality subjects with the same class labels should be closer in the new feature-reduced space. In the second step, a multi-kernel support vector machine (SVM) is adopted to fuse the selected features from multi-modality data for final classification. To validate our method, we perform experiments on the Alzheimer’s Disease Neuroimaging Initiative (ADNI) database using baseline MRI and FDG-PET imaging data. The experimental results demonstrate that our proposed method achieves better classification performance compared with several state-of-the-art methods for multimodal classification of AD/MCI. PMID:26572145

Spatial accessibility to healthcare services in Shenzhen, China: improving the multi-modal two-step floating catchment area method by estimating travel time via online map APIs.

PubMed

Tao, Zhuolin; Yao, Zaoxing; Kong, Hui; Duan, Fei; Li, Guicai

2018-05-09

Shenzhen has rapidly grown into a megacity in the recent decades. It is a challenging task for the Shenzhen government to provide sufficient healthcare services. The spatial configuration of healthcare services can influence the convenience for the consumers to obtain healthcare services. Spatial accessibility has been widely adopted as a scientific measurement for evaluating the rationality of the spatial configuration of healthcare services. The multi-modal two-step floating catchment area (2SFCA) method is an important advance in the field of healthcare accessibility modelling, which enables the simultaneous assessment of spatial accessibility via multiple transport modes. This study further develops the multi-modal 2SFCA method by introducing online map APIs to improve the estimation of travel time by public transit or by car respectively. As the results show, the distribution of healthcare accessibility by multi-modal 2SFCA shows significant spatial disparity. Moreover, by dividing the multi-modal accessibility into car-mode and transit-mode accessibility, this study discovers that the transit-mode subgroup is disadvantaged in the competition for healthcare services with the car-mode subgroup. The disparity in transit-mode accessibility is the main reason of the uneven pattern of healthcare accessibility in Shenzhen. The findings suggest improving the public transit conditions for accessing healthcare services to reduce the disparity of healthcare accessibility. More healthcare services should be allocated in the eastern and western Shenzhen, especially sub-districts in Dapeng District and western Bao'an District. As these findings cannot be drawn by the traditional single-modal 2SFCA method, the advantage of the multi-modal 2SFCA method is significant to both healthcare studies and healthcare system planning.

Development of a time-dependent incompressible Navier-Stokes solver based on a fractional-step method

NASA Technical Reports Server (NTRS)

Rosenfeld, Moshe

1990-01-01

The development, validation and application of a fractional step solution method of the time-dependent incompressible Navier-Stokes equations in generalized coordinate systems are discussed. A solution method that combines a finite-volume discretization with a novel choice of the dependent variables and a fractional step splitting to obtain accurate solutions in arbitrary geometries was previously developed for fixed-grids. In the present research effort, this solution method is extended to include more general situations, including cases with moving grids. The numerical techniques are enhanced to gain efficiency and generality.

Gastroprotective activity of the ethanol extract from the inner bark of Caesalpinia pyramidalis in rats.

PubMed

Ribeiro, Ana Roseli S; Diniz, Polyana B F; Estevam, Charles S; Pinheiro, Malone S; Albuquerque-Júnior, Ricardo L C; Thomazzi, Sara M

2013-05-20

Caesalpinia pyramidalis Tul. (Fabaceae), known as "catingueira", has been used in folk medicine in the treatment of various disorders such as gastritis, heartburn, indigestion, and stomach ache. However, the gastroprotective properties of this species have not yet been studied. The ethanol extract of Caesalpinia pyramidalis inner bark was used in rats via oral route, at the doses of 30, 100, and 300 mg/kg. The antiulcer assays were performed using the ethanol- and nonsteroidal anti-inflammatory drug-induced ulcer models. Gastric secretion parameters (volume, pH, and total acidity) were also evaluated by the pylorus ligated model, and the mucus in the gastric content was determined. The anti-Helicobacter pylori activity of the ethanol extract of Caesalpinia pyramidalis was performed using the agar-well diffusion and broth microdilution methods. The ethanol extract (30, 100, and 300 mg/kg) produced dose dependent inhibition (P<0.01) on the ulcer lesion index, the total lesion area, and the percentage of lesion area in the ethanol-induced ulcer model. The ethanol extract (30, 100, and 300 mg/kg) also reduced (P<0.001) the ulcer index in the indomethacin-induced ulcer model. In the model ligature pylorus, the treatment with Caesalpinia pyramidalis ethanol extract failed to significantly change the gastric secretion parameters. However, after treatment with the ethanol extract of Caesalpinia pyramidalis (30, 100, and 300 mg/kg), there was a significant increase (P<0.05) in mucus production. The ethanol extract showed anti-Helicobacter pylori activity, with inhibition halos of 12.0 ± 1.7 mm at 10,000 μg/mL. The minimum inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) values of the ethanol extract were of 625 and 10,000 μg/mL, respectively. Collectively, the present results suggest that the ethanol extract of Caesalpinia pyramidalis displays gastroprotective actions, supporting the folkloric usage of the plant to treat various gastrointestinal disturbances. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Distributed micro-radar system for detection and tracking of low-profile, low-altitude targets

NASA Astrophysics Data System (ADS)

Gorwara, Ashok; Molchanov, Pavlo

2016-05-01

Proposed airborne surveillance radar system can detect, locate, track, and classify low-profile, low-altitude targets: from traditional fixed and rotary wing aircraft to non-traditional targets like unmanned aircraft systems (drones) and even small projectiles. Distributed micro-radar system is the next step in the development of passive monopulse direction finder proposed by Stephen E. Lipsky in the 80s. To extend high frequency limit and provide high sensitivity over the broadband of frequencies, multiple angularly spaced directional antennas are coupled with front end circuits and separately connected to a direction finder processor by a digital interface. Integration of antennas with front end circuits allows to exclude waveguide lines which limits system bandwidth and creates frequency dependent phase errors. Digitizing of received signals proximate to antennas allows loose distribution of antennas and dramatically decrease phase errors connected with waveguides. Accuracy of direction finding in proposed micro-radar in this case will be determined by time accuracy of digital processor and sampling frequency. Multi-band, multi-functional antennas can be distributed around the perimeter of a Unmanned Aircraft System (UAS) and connected to the processor by digital interface or can be distributed between swarm/formation of mini/micro UAS and connected wirelessly. Expendable micro-radars can be distributed by perimeter of defense object and create multi-static radar network. Low-profile, lowaltitude, high speed targets, like small projectiles, create a Doppler shift in a narrow frequency band. This signal can be effectively filtrated and detected with high probability. Proposed micro-radar can work in passive, monostatic or bistatic regime.

Biology meets physics: Reductionism and multi-scale modeling of morphogenesis.

PubMed

Green, Sara; Batterman, Robert

2017-02-01

A common reductionist assumption is that macro-scale behaviors can be described "bottom-up" if only sufficient details about lower-scale processes are available. The view that an "ideal" or "fundamental" physics would be sufficient to explain all macro-scale phenomena has been met with criticism from philosophers of biology. Specifically, scholars have pointed to the impossibility of deducing biological explanations from physical ones, and to the irreducible nature of distinctively biological processes such as gene regulation and evolution. This paper takes a step back in asking whether bottom-up modeling is feasible even when modeling simple physical systems across scales. By comparing examples of multi-scale modeling in physics and biology, we argue that the "tyranny of scales" problem presents a challenge to reductive explanations in both physics and biology. The problem refers to the scale-dependency of physical and biological behaviors that forces researchers to combine different models relying on different scale-specific mathematical strategies and boundary conditions. Analyzing the ways in which different models are combined in multi-scale modeling also has implications for the relation between physics and biology. Contrary to the assumption that physical science approaches provide reductive explanations in biology, we exemplify how inputs from physics often reveal the importance of macro-scale models and explanations. We illustrate this through an examination of the role of biomechanical modeling in developmental biology. In such contexts, the relation between models at different scales and from different disciplines is neither reductive nor completely autonomous, but interdependent. Copyright © 2016 Elsevier Ltd. All rights reserved.

Multi-model groundwater-management optimization: reconciling disparate conceptual models

NASA Astrophysics Data System (ADS)

Timani, Bassel; Peralta, Richard

2015-09-01

Disagreement among policymakers often involves policy issues and differences between the decision makers' implicit utility functions. Significant disagreement can also exist concerning conceptual models of the physical system. Disagreement on the validity of a single simulation model delays discussion on policy issues and prevents the adoption of consensus management strategies. For such a contentious situation, the proposed multi-conceptual model optimization (MCMO) can help stakeholders reach a compromise strategy. MCMO computes mathematically optimal strategies that simultaneously satisfy analogous constraints and bounds in multiple numerical models that differ in boundary conditions, hydrogeologic stratigraphy, and discretization. Shadow prices and trade-offs guide the process of refining the first MCMO-developed `multi-model strategy into a realistic compromise management strategy. By employing automated cycling, MCMO is practical for linear and nonlinear aquifer systems. In this reconnaissance study, MCMO application to the multilayer Cache Valley (Utah and Idaho, USA) river-aquifer system employs two simulation models with analogous background conditions but different vertical discretization and boundary conditions. The objective is to maximize additional safe pumping (beyond current pumping), subject to constraints on groundwater head and seepage from the aquifer to surface waters. MCMO application reveals that in order to protect the local ecosystem, increased groundwater pumping can satisfy only 40 % of projected water demand increase. To explore the possibility of increasing that pumping while protecting the ecosystem, MCMO clearly identifies localities requiring additional field data. MCMO is applicable to other areas and optimization problems than used here. Steps to prepare comparable sub-models for MCMO use are area-dependent.