Dynamics of the brain: Mathematical models and non-invasive experimental studies
NASA Astrophysics Data System (ADS)
Toronov, V.; Myllylä, T.; Kiviniemi, V.; Tuchin, V. V.
2013-10-01
Dynamics is an essential aspect of the brain function. In this article we review theoretical models of neural and haemodynamic processes in the human brain and experimental non-invasive techniques developed to study brain functions and to measure dynamic characteristics, such as neurodynamics, neurovascular coupling, haemodynamic changes due to brain activity and autoregulation, and cerebral metabolic rate of oxygen. We focus on emerging theoretical biophysical models and experimental functional neuroimaging results, obtained mostly by functional magnetic resonance imaging (fMRI) and near-infrared spectroscopy (NIRS). We also included our current results on the effects of blood pressure variations on cerebral haemodynamics and simultaneous measurements of fast processes in the brain by near-infrared spectroscopy and a very novel functional MRI technique called magnetic resonance encephalography. Based on a rapid progress in theoretical and experimental techniques and due to the growing computational capacities and combined use of rapidly improving and emerging neuroimaging techniques we anticipate during next decade great achievements in the overall knowledge of the human brain.
Experimental Mathematics and Computational Statistics
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bailey, David H.; Borwein, Jonathan M.
2009-04-30
The field of statistics has long been noted for techniques to detect patterns and regularities in numerical data. In this article we explore connections between statistics and the emerging field of 'experimental mathematics'. These includes both applications of experimental mathematics in statistics, as well as statistical methods applied to computational mathematics.
Engineering metallic nanostructures for plasmonics and nanophotonics
Lindquist, Nathan C; Nagpal, Prashant; McPeak, Kevin M; Norris, David J; Oh, Sang-Hyun
2012-01-01
Metallic nanostructures now play an important role in many applications. In particular, for the emerging fields of plasmonics and nanophotonics, the ability to engineer metals on nanometric scales allows the development of new devices and the study of exciting physics. This review focuses on top-down nanofabrication techniques for engineering metallic nanostructures, along with computational and experimental characterization techniques. A variety of current and emerging applications are also covered. PMID:22790420
Engineering metallic nanostructures for plasmonics and nanophotonics
NASA Astrophysics Data System (ADS)
Lindquist, Nathan C.; Nagpal, Prashant; McPeak, Kevin M.; Norris, David J.; Oh, Sang-Hyun
2012-03-01
Metallic nanostructures now play an important role in many applications. In particular, for the emerging fields of plasmonics and nanophotonics, the ability to engineer metals on nanometric scales allows the development of new devices and the study of exciting physics. This review focuses on top-down nanofabrication techniques for engineering metallic nanostructures, along with computational and experimental characterization techniques. A variety of current and emerging applications are also covered.
Toward a Community of Seekers: A Report on Experimental Higher Education.
ERIC Educational Resources Information Center
Tubbs, Walter E. Jr., Ed.
Many experimental higher education programs have emerged in the past decade as an attempt to answer the educational needs of new students in higher education and the manpower requirements of society. New techniques of instruction, curriculum and governance have evolved and new ways of managing human, plant, and financial resources have been…
New fluorescence techniques for high-throughput drug discovery.
Jäger, S; Brand, L; Eggeling, C
2003-12-01
The rapid increase of compound libraries as well as new targets emerging from the Human Genome Project require constant progress in pharmaceutical research. An important tool is High-Throughput Screening (HTS), which has evolved as an indispensable instrument in the pre-clinical target-to-IND (Investigational New Drug) discovery process. HTS requires machinery, which is able to test more than 100,000 potential drug candidates per day with respect to a specific biological activity. This calls for certain experimental demands especially with respect to sensitivity, speed, and statistical accuracy, which are fulfilled by using fluorescence technology instrumentation. In particular the recently developed family of fluorescence techniques, FIDA (Fluorescence Intensity Distribution Analysis), which is based on confocal single-molecule detection, has opened up a new field of HTS applications. This report describes the application of these new techniques as well as of common fluorescence techniques--such as confocal fluorescence lifetime and anisotropy--to HTS. It gives experimental examples and presents advantages and disadvantages of each method. In addition the most common artifacts (auto-fluorescence or quenching by the drug candidates) emerging from the fluorescence detection techniques are highlighted and correction methods for confocal fluorescence read-outs are presented, which are able to circumvent this deficiency.
[Development and Application of an Overcoming Compassion Fatigue Program for Emergency Nurses].
Kim, Yeong Ah; Park, Jeong Sook
2016-04-01
This study was conducted to develop a program to help emergency nurses overcome compassion fatigue, and to analyze the effects of the program. A nonequivalent control group pretest-posttest design was used. There were 14 participants in the experimental group and 18 subjects in the control group. The program was comprised of five, weekly 80-minute sessions including understanding and assessment of compassion fatigue, enhancing positive affect, balancing work-life, planning self care, training in relaxation techniques and cognitive restructuring, and getting social support. Research variables were ego-resiliency, compassion satisfaction and compassion fatigue of the ProQOL 5, and salivary cortisol. Data were analyzed using Chi-square test, independent t-test, and paired t-test. The first hypothesis, "There will be a difference in scores for ego resiliency between the experimental group and the control group". was not supported. The second hypothesis, "There will be a difference in scores for compassion satisfaction between the experimental group and the control group" was supported (t=2.15, p=.046). The third hypothesis, "There will be a difference in scores for compassion fatigue between the experimental group and the control group" was not supported. The first program for emergency nurses to overcome compassion fatigue in Korea was effective in increasing emergency nurses' compassion satisfaction and decreasing salivary cortisol level in the experimental group. Therefore, this program for overcoming compassion fatigue is useful to increase emergency nurses' compassion satisfaction. However replication studies of short-term intensive program reflecting emergency nurses' opinion are needed.
Data-Mining Techniques in Detecting Factors Linked to Academic Achievement
ERIC Educational Resources Information Center
Martínez Abad, Fernando; Chaparro Caso López, Alicia A.
2017-01-01
In light of the emergence of statistical analysis techniques based on data mining in education sciences, and the potential they offer to detect non-trivial information in large databases, this paper presents a procedure used to detect factors linked to academic achievement in large-scale assessments. The study is based on a non-experimental,…
NASA Astrophysics Data System (ADS)
Lee, Sehwook; Livan, Michele; Wigmans, Richard
2018-04-01
In the past 20 years, dual-readout calorimetry has emerged as a technique for measuring the properties of high-energy hadrons and hadron jets that offers considerable advantages compared with the instruments that are currently used for this purpose in experiments at the high-energy frontier. The status of this experimental technique and the challenges faced for its further development are reviewed.
Modems for emerging digital cellular-mobile radio system
NASA Technical Reports Server (NTRS)
Feher, Kamilo
1991-01-01
Digital modem techniques for emerging digital cellular telecommunications-mobile radio system applications are described and analyzed. In particular, theoretical performance, experimental results, principles of operation, and various architectures of pi/4-QPSK (pi/4-shifted coherent or differential QPSK) modems for second-generation US digital cellular radio system applications are presented. The spectral/power efficiency and performance of the pi/4-QPSK modems (American and Japanese digital cellular emerging standards) are studied and briefly compared to GMSK (Gaussian minimum-shift keying) modems (proposed for European DECT and GSM cellular standards). Improved filtering strategies and digital pilot-aided (digital channel sounding) techniques are also considered for pi/4-QPSK and other digital modems. These techniques could significantly improve the performance of digital cellular and other digital land mobile and satellite mobile radio systems. More spectrally efficient modem trends for future cellular/mobile (land mobile) and satellite communication systems applications are also highlighted.
NASA Astrophysics Data System (ADS)
Pirsalami, Sedigheh; Zebarjad, Seyed Mojtaba; Daneshmanesh, Habib
2017-08-01
Transparent conductors (TCs) have a wide range of applications in numerous electronic and optoelectronic devices. This review provides an overview of the emergence of metallic nanowire networks (MNNs) as promising building blocks for the next generation transparent conductors. The fundamental aspects, structure-property relations, fabrication techniques and the corresponding challenges are reviewed. Theoretical and experimental researches suggest that nanowires with smaller diameter, longer length and higher aspect ratio have higher performance. Yet, the development of an efficient synthesis technique for the production of MNNs has remained a challenge. The synthesis method is also crucial to the scalability and the commercial potential of these emerging TCs. The most promising techniques for the synthesis together with their advantages, limitations and the recent findings are here discussed. Finally, we will try to show the promising future research trends in MNNs to have an approach to design the next generation TCs.
ERIC Educational Resources Information Center
Bagdadi, Andrea; Orona, Nadia; Fernandez, Eugenio; Altamirano, Anibal; Amorena, Carlos
2010-01-01
We have realized that our Biology undergraduate students learn biological concepts as established truths without awareness of the body of experimental evidence supporting the emerging models as usually presented in handbooks and texts in general. Therefore, we have implemented a laboratory practice in our course of Physiology and Biophysics, aimed…
Modeling Emergence in Neuroprotective Regulatory Networks
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sanfilippo, Antonio P.; Haack, Jereme N.; McDermott, Jason E.
2013-01-05
The use of predictive modeling in the analysis of gene expression data can greatly accelerate the pace of scientific discovery in biomedical research by enabling in silico experimentation to test disease triggers and potential drug therapies. Techniques that focus on modeling emergence, such as agent-based modeling and multi-agent simulations, are of particular interest as they support the discovery of pathways that may have never been observed in the past. Thus far, these techniques have been primarily applied at the multi-cellular level, or have focused on signaling and metabolic networks. We present an approach where emergence modeling is extended to regulatorymore » networks and demonstrate its application to the discovery of neuroprotective pathways. An initial evaluation of the approach indicates that emergence modeling provides novel insights for the analysis of regulatory networks that can advance the discovery of acute treatments for stroke and other diseases.« less
[Application of hand-use ProTaper instruments in endodontic treatment of molar canals].
Ma, Sui-qi; Xie, Qian; Zhou, Yin-feng
2010-07-01
To evaluate the application of hand-use ProTaper instruments in endodontic treatment of molar canals. A total of 203 permanent molars were randomly divided into the experimental group (99 molars) and control group (104 molars) prepared by hand-use ProTaper instruments and standard stainless steel K-file, respectively. The molars in the two groups were obturated by cold lateral condensation technique. The root canal preparation and obturation were evaluated by radiograph, and the working time of preparation and post-operative emergencies were analyzed. The preparation time in the experimental group was obviously shorter than that in the control group (P<0.01). The rate of satisfactory effect was significantly higher in the experimental group than in the control group (P<0.01), and the rate of post-operative emergencies was significantly lower in the experimental group (P<0.01). The application of hand-use ProTaper instruments may improve the effect of root canal treatment of the molars and shorten the working time and reduce the post-operative emergencies.
Shaban, Ramon Z; Considine, Julie; Fry, Margaret; Curtis, Kate
2017-02-01
Generating knowledge through quality research is fundamental to the advancement of professional practice in emergency nursing and care. There are multiple paradigms, designs and methods available to researchers to respond to challenges in clinical practice. Systematic reviews, randomised control trials and other forms of experimental research are deemed the gold standard of evidence, but there are comparatively few such trials in emergency care. In some instances it is not possible or appropriate to undertake experimental research. When exploring new or emerging problems where there is limited evidence available, non-experimental methods are required and appropriate. This paper provides the theoretical foundations and an exemplar of the use of case study and case-based research to explore a new and emerging problem in the context of emergency care. It examines pre-hospital clinical judgement and decision-making of mental illness by paramedics. Using an exemplar the paper explores the theoretical foundations and conceptual frameworks of case study, it explains how cases are defined and the role researcher in this form of inquiry, it details important principles and the procedures for data gathering and analysis, and it demonstrates techniques to enhance trustworthiness and credibility of the research. Moreover, it provides theoretically and practical insights into using case study in emergency care. Copyright © 2017 College of Emergency Nursing Australasia. Published by Elsevier Ltd. All rights reserved.
Does Angling Technique Selectively Target Fishes Based on Their Behavioural Type?
Wilson, Alexander D. M.; Brownscombe, Jacob W.; Sullivan, Brittany; Jain-Schlaepfer, Sofia; Cooke, Steven J.
2015-01-01
Recently, there has been growing recognition that fish harvesting practices can have important impacts on the phenotypic distributions and diversity of natural populations through a phenomenon known as fisheries-induced evolution. Here we experimentally show that two common recreational angling techniques (active crank baits versus passive soft plastics) differentially target wild largemouth bass (Micropterus salmoides) and rock bass (Ambloplites rupestris) based on variation in their behavioural tendencies. Fish were first angled in the wild using both techniques and then brought back to the laboratory and tested for individual-level differences in common estimates of personality (refuge emergence, flight-initiation-distance, latency-to-recapture and with a net, and general activity) in an in-lake experimental arena. We found that different angling techniques appear to selectively target these species based on their boldness (as characterized by refuge emergence, a standard measure of boldness in fishes) but not other assays of personality. We also observed that body size was independently a significant predictor of personality in both species, though this varied between traits and species. Our results suggest a context-dependency for vulnerability to capture relative to behaviour in these fish species. Ascertaining the selective pressures angling practices exert on natural populations is an important area of fisheries research with significant implications for ecology, evolution, and resource management. PMID:26284779
Probing cytoskeleton organisation of neuroblastoma cells with single-cell force spectroscopy.
Mescola, Andrea; Vella, Serena; Scotto, Marco; Gavazzo, Paola; Canale, Claudio; Diaspro, Alberto; Pagano, Aldo; Vassalli, Massimo
2012-05-01
Single-cell force spectroscopy is an emerging technique in the field of biomedicine because it has proved to be a unique tool to obtain mechanical and functional information on living cells, with force resolution up to single molecular bonds. This technique was applied to the study of the cytoskeleton organisation of neuroblastoma cells, a life-threatening cancer typically developing during childhood, and the results were interpreted on the basis of reference experiments on human embryonic kidney cell line. An intimate connection emerges among cellular state, cytoskeleton organisation and experimental outcome that can be potentially exploited towards a new method for cancer stadiation of neuroblastoma cells. Copyright © 2012 John Wiley & Sons, Ltd.
Mission Systems Open Architecture Science and Technology (MOAST) program
NASA Astrophysics Data System (ADS)
Littlejohn, Kenneth; Rajabian-Schwart, Vahid; Kovach, Nicholas; Satterthwaite, Charles P.
2017-04-01
The Mission Systems Open Architecture Science and Technology (MOAST) program is an AFRL effort that is developing and demonstrating Open System Architecture (OSA) component prototypes, along with methods and tools, to strategically evolve current OSA standards and technical approaches, promote affordable capability evolution, reduce integration risk, and address emerging challenges [1]. Within the context of open architectures, the program is conducting advanced research and concept development in the following areas: (1) Evolution of standards; (2) Cyber-Resiliency; (3) Emerging Concepts and Technologies; (4) Risk Reduction Studies and Experimentation; and (5) Advanced Technology Demonstrations. Current research includes the development of methods, tools, and techniques to characterize the performance of OMS data interconnection methods for representative mission system applications. Of particular interest are the OMS Critical Abstraction Layer (CAL), the Avionics Service Bus (ASB), and the Bulk Data Transfer interconnects, as well as to develop and demonstrate cybersecurity countermeasures techniques to detect and mitigate cyberattacks against open architecture based mission systems and ensure continued mission operations. Focus is on cybersecurity techniques that augment traditional cybersecurity controls and those currently defined within the Open Mission System and UCI standards. AFRL is also developing code generation tools and simulation tools to support evaluation and experimentation of OSA-compliant implementations.
NASA Astrophysics Data System (ADS)
Omenzetter, Piotr; de Lautour, Oliver R.
2010-04-01
Developed for studying long, periodic records of various measured quantities, time series analysis methods are inherently suited and offer interesting possibilities for Structural Health Monitoring (SHM) applications. However, their use in SHM can still be regarded as an emerging application and deserves more studies. In this research, Autoregressive (AR) models were used to fit experimental acceleration time histories from two experimental structural systems, a 3- storey bookshelf-type laboratory structure and the ASCE Phase II SHM Benchmark Structure, in healthy and several damaged states. The coefficients of the AR models were chosen as damage sensitive features. Preliminary visual inspection of the large, multidimensional sets of AR coefficients to check the presence of clusters corresponding to different damage severities was achieved using Sammon mapping - an efficient nonlinear data compression technique. Systematic classification of damage into states based on the analysis of the AR coefficients was achieved using two supervised classification techniques: Nearest Neighbor Classification (NNC) and Learning Vector Quantization (LVQ), and one unsupervised technique: Self-organizing Maps (SOM). This paper discusses the performance of AR coefficients as damage sensitive features and compares the efficiency of the three classification techniques using experimental data.
A Comparison of Techniques for Camera Selection and Hand-Off in a Video Network
NASA Astrophysics Data System (ADS)
Li, Yiming; Bhanu, Bir
Video networks are becoming increasingly important for solving many real-world problems. Multiple video sensors require collaboration when performing various tasks. One of the most basic tasks is the tracking of objects, which requires mechanisms to select a camera for a certain object and hand-off this object from one camera to another so as to accomplish seamless tracking. In this chapter, we provide a comprehensive comparison of current and emerging camera selection and hand-off techniques. We consider geometry-, statistics-, and game theory-based approaches and provide both theoretical and experimental comparison using centralized and distributed computational models. We provide simulation and experimental results using real data for various scenarios of a large number of cameras and objects for in-depth understanding of strengths and weaknesses of these techniques.
Emergent quantum mechanics without wavefunctions
NASA Astrophysics Data System (ADS)
Mesa Pascasio, J.; Fussy, S.; Schwabl, H.; Grössing, G.
2016-03-01
We present our model of an Emergent Quantum Mechanics which can be characterized by “realism without pre-determination”. This is illustrated by our analytic description and corresponding computer simulations of Bohmian-like “surreal” trajectories, which are obtained classically, i.e. without the use of any quantum mechanical tool such as wavefunctions. However, these trajectories do not necessarily represent ontological paths of particles but rather mappings of the probability density flux in a hydrodynamical sense. Modelling emergent quantum mechanics in a high-low intesity double slit scenario gives rise to the “quantum sweeper effect” with a characteristic intensity pattern. This phenomenon should be experimentally testable via weak measurement techniques.
Fonseca, Antonio F B DA; Scheffer, Jussara P; Coelho, Barbara P; Aiello, Graciane; Guimarães, Arthur G; Gama, Carlos R B; Vescovini, Victor; Cabral, Paula G A; Oliveira, André L A
2016-09-01
The most common cause of spinal cord injury are high impact trauma, which often result in some motor impairment, sensory or autonomic a greater or lesser extent in the distal areas the level of trauma. In terms of survival and complications due to sequelae, veterinary patients have a poor prognosis unfavorable. Therefore justified the study of experimental models of spinal cord injury production that could provide more support to research potential treatments for spinal cord injuries in medicine and veterinary medicine. Preclinical studies of acute spinal cord injury require an experimental animal model easily reproducible. The most common experimental animal model is the rat, and several techniques for producing a spinal cord injury. The objective of this study was to describe and evaluate the effectiveness of acute spinal cord injury production technique through inflation of Fogarty(r) catheter using rabbits as an experimental model because it is a species that has fewer conclusive publications and contemplating. The main requirements of a model as low cost, handling convenience, reproducibility and uniformity. The technique was adequate for performing preclinical studies in neuro-traumatology area, effectively leading to degeneration and necrosis of the nervous tissue fostering the emergence of acute paraplegia.
Critical phenomena of emergent monopoles in a chiral magnet
NASA Astrophysics Data System (ADS)
Zhang, Xiao-Xiao; Nagaosa, Naoto
A three-dimensional cubic Skyrmion crystal in the bulk, which is simultaneously a lattice of monopole-antimonopole pairs predicted theoretically, has been recently identified experimentally in MnGe. Adopting appropriate temperature Green's function technique for optical conductivity and devising a solvable phonon-magnon interaction, we systematically developed the theory of coupling spin-waves to both itinerant electrons and mechanical degrees of freedom in this chiral magnet, describing the latest experimental observations including anomalies and critical phenomena in magnetotransport and magnetoelasticity, which are identified as hallmarks of fluctuations of the emergent monopolar fields upon the nontrivial monopole dynamics and especially a topological phase transition signifying strong correlation. As a whole, they speak for a crucial role played by the monopole defects and hence the real-space spin topology in this material.
Nanopores formed by DNA origami: a review.
Bell, Nicholas A W; Keyser, Ulrich F
2014-10-01
Nanopores have emerged over the past two decades to become an important technique in single molecule experimental physics and biomolecule sensing. Recently DNA nanotechnology, in particular DNA origami, has been used for the formation of nanopores in insulating materials. DNA origami is a very attractive technique for the formation of nanopores since it enables the construction of 3D shapes with precise control over geometry and surface functionality. DNA origami has been applied to nanopore research by forming hybrid architectures with solid state nanopores and by direct insertion into lipid bilayers. This review discusses recent experimental work in this area and provides an outlook for future avenues and challenges. Copyright © 2014 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.
Application of additive laser technologies in the gas turbine blades design process
NASA Astrophysics Data System (ADS)
Shevchenko, I. V.; Rogalev, A. N.; Osipov, S. K.; Bychkov, N. M.; Komarov, I. I.
2017-11-01
An emergence of modern innovative technologies requires delivering new and modernization existing design and production processes. It is especially relevant for designing the high-temperature turbines of gas turbine engines, development of which is characterized by a transition to higher parameters of working medium in order to improve their efficient performance. A design technique for gas turbine blades based on predictive verification of thermal and hydraulic models of their cooling systems by testing of a blade prototype fabricated using the selective laser melting technology was presented in this article. Technique was proven at the time of development of the first stage blade cooling system for the high-pressure turbine. An experimental procedure for verification of a thermal model of the blades with convective cooling systems based on the comparison of heat-flux density obtained from the numerical simulation data and results of tests in a liquid-metal thermostat was developed. The techniques makes it possible to obtain an experimentally tested blade version and to exclude its experimental adjustment after the start of mass production.
Gelman, Hannah; Gruebele, Martin
2014-01-01
Fast folding proteins have been a major focus of computational and experimental study because they are accessible to both techniques: they are small and fast enough to be reasonably simulated with current computational power, but have dynamics slow enough to be observed with specially developed experimental techniques. This coupled study of fast folding proteins has provided insight into the mechanisms which allow some proteins to find their native conformation well less than 1 ms and has uncovered examples of theoretically predicted phenomena such as downhill folding. The study of fast folders also informs our understanding of even “slow” folding processes: fast folders are small, relatively simple protein domains and the principles that govern their folding also govern the folding of more complex systems. This review summarizes the major theoretical and experimental techniques used to study fast folding proteins and provides an overview of the major findings of fast folding research. Finally, we examine the themes that have emerged from studying fast folders and briefly summarize their application to protein folding in general as well as some work that is left to do. PMID:24641816
Detection of bremsstrahlung radiation of 90Sr-90Y for emergency lung counting.
Ho, A; Hakmana Witharana, S S; Jonkmans, G; Li, L; Surette, R A; Dubeau, J; Dai, X
2012-09-01
This study explores the possibility of developing a field-deployable (90)Sr detector for rapid lung counting in emergency situations. The detection of beta-emitters (90)Sr and its daughter (90)Y inside the human lung via bremsstrahlung radiation was performed using a 3″ × 3″ NaI(Tl) crystal detector and a polyethylene-encapsulated source to emulate human lung tissue. The simulation results show that this method is a viable technique for detecting (90)Sr with a minimum detectable activity (MDA) of 1.07 × 10(4) Bq, using a realistic dual-shielded detector system in a 0.25-µGy h(-1) background field for a 100-s scan. The MDA is sufficiently sensitive to meet the requirement for emergency lung counting of Type S (90)Sr intake. The experimental data were verified using Monte Carlo calculations, including an estimate for internal bremsstrahlung, and an optimisation of the detector geometry was performed. Optimisations in background reduction techniques and in the electronic acquisition systems are suggested.
Cytological Analysis of Meiosis in Caenorhabditis elegans
Phillips, Carolyn M.; McDonald, Kent L.; Dernburg, Abby F.
2011-01-01
The nematode Caenorhabditis elegans has emerged as an informative experimental system for analysis of meiosis, in large part because of the advantageous physical organization of meiotic nuclei as a gradient of stages within the germline. Here we provide tools for detailed observational studies of cells within the worm gonad, including techniques for light and electron microscopy. PMID:19685325
NASA Technical Reports Server (NTRS)
Sanchez, Jose Enrique; Auge, Estanislau; Santalo, Josep; Blanes, Ian; Serra-Sagrista, Joan; Kiely, Aaron
2011-01-01
A new standard for image coding is being developed by the MHDC working group of the CCSDS, targeting onboard compression of multi- and hyper-spectral imagery captured by aircraft and satellites. The proposed standard is based on the "Fast Lossless" adaptive linear predictive compressor, and is adapted to better overcome issues of onboard scenarios. In this paper, we present a review of the state of the art in this field, and provide an experimental comparison of the coding performance of the emerging standard in relation to other state-of-the-art coding techniques. Our own independent implementation of the MHDC Recommended Standard, as well as of some of the other techniques, has been used to provide extensive results over the vast corpus of test images from the CCSDS-MHDC.
Aircraft Drag Prediction and Reduction
1985-07-01
Figure 10 with their subsources. The major source groups are the airfiame noise sources, the propulsion system noise sources, and the lamirar-flow control ...the emerging areas of non -planar geometry and large-eddy alteration. Turbulent control techniques for air generally result in modest (but...17. 57. Ketchem, Jeffery J.; and Velkoff, Henry R.: An Experimental Investigation of the Effect of Electrically Induced Controlled Frequency
Real-time intravital microscopy of individual nanoparticle dynamics in liver and tumors of live mice
van de Ven, Anne L; Kim, Pilhan; Ferrari, Mauro; Yun, Seok Hyun
2013-01-01
Intravital microscopy is emerging as an important experimental tool for the research and development of multi-functional therapeutic nanoconstructs. The direct visualization of nanoparticle dynamics within live animals provides invaluable insights into the mechanisms that regulate nanotherapeutics transport and cell-particle interactions. Here we present a protocol to image the dynamics of nanoparticles within the liver and tumors of live mice immediately following systemic injection using a high-speed (30-400 fps) confocal or multi-photon laser-scanning fluorescence microscope. Techniques for quantifying the real-time accumulation and cellular association of individual particles with a size ranging from several tens of nanometers to micrometers are described, as well as an experimental strategy for labeling Kupffer cells in the liver in vivo. Experimental design considerations and controls are provided, as well as minimum equipment requirements. The entire protocol takes approximately 4-8 hours and yields quantitative information. These techniques can serve to study a wide range of kinetic parameters that drive nanotherapeutics delivery, uptake, and treatment response. PMID:25383179
Reality, locality and all that: "experimental metaphysics" and the quantum foundations
NASA Astrophysics Data System (ADS)
Cavalcanti, Eric G.
2008-10-01
In recent decades there has been a resurge of interest in the foundations of quantum theory, partly motivated by new experimental techniques, partly by the emerging field of quantum information science. Old questions, asked since the seminal article by Einstein, Podolsky and Rosen (EPR), are being revisited. The work of John Bell has changed the direction of investigation by recognising that those fundamental philosophical questions can have, after all, input from experiment. Abner Shimony has aptly termed this new field of enquiry "experimental metaphysics". The objective of this Thesis is to contribute to that body of research, by formalising old concepts, proposing new ones, and finding new results in well-studied areas. Without losing from sight that the appeal of experimental metaphysics comes from the adjective, every major result is followed by clear experimental proposals for quantum-atom optical setups.
Canon, Abbey J; Lauterbach, Nicholas; Bates, Jessica; Skoland, Kristin; Thomas, Paul; Ellingson, Josh; Ruston, Chelsea; Breuer, Mary; Gerardy, Kimberlee; Hershberger, Nicole; Hayman, Kristen; Buckley, Alexis; Holtkamp, Derald; Karriker, Locke
2017-06-15
OBJECTIVE To develop and evaluate a pyramid training method for teaching techniques for collection of diagnostic samples from swine. DESIGN Experimental trial. SAMPLE 45 veterinary students. PROCEDURES Participants went through a preinstruction assessment to determine their familiarity with the equipment needed and techniques used to collect samples of blood, nasal secretions, feces, and oral fluid from pigs. Participants were then shown a series of videos illustrating the correct equipment and techniques for collecting samples and were provided hands-on pyramid-based instruction wherein a single swine veterinarian trained 2 or 3 participants on each of the techniques and each of those participants, in turn, trained additional participants. Additional assessments were performed after the instruction was completed. RESULTS Following the instruction phase, percentages of participants able to collect adequate samples of blood, nasal secretions, feces, and oral fluid increased, as did scores on a written quiz assessing participants' ability to identify the correct equipment, positioning, and procedures for collection of samples. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that the pyramid training method may be a feasible way to rapidly increase diagnostic sampling capacity during an emergency veterinary response to a swine disease outbreak.
Beta-Delayed Neutron Spectroscopy with Trapped Fission Products
NASA Astrophysics Data System (ADS)
Czeszumska, A.; Scielzo, N. D.; Norman, E. B.; Savard, G.; Aprahamian, A.; Burkey, M.; Caldwell, S. A.; Chiara, C. J.; Clark, J. A.; Harker, J.; Marley, S. T.; Morgan, G.; Orford, R.; Padgett, S.; Perez Galvan, A.; Segel, R. E.; Sharma, K. S.; Siegl, K.; Strauss, S.; Yee, R. M.
2014-09-01
Characterizing β-delayed neutron emission (βn) is of importance in reactor safety modeling, understanding of r-process nucleosynthesis, and nuclear structure studies. A newly developed technique enables a reliable measurement of βn branching ratios and neutron energy spectra without directly detecting neutrons. Ions of interest are loaded into a Paul trap surrounded by an array of radiation detectors. Upon decay, recoiling daughter nuclei and emitted particles emerge from the center of the trap with minimal scattering. The neutron energy is then determined from the time-of-flight, and hence momentum, of the recoiling ions. I will explain the details of the technique, and present the results from the most recent experimental campaign at the CARIBU facility at Argonne National Laboratory. Characterizing β-delayed neutron emission (βn) is of importance in reactor safety modeling, understanding of r-process nucleosynthesis, and nuclear structure studies. A newly developed technique enables a reliable measurement of βn branching ratios and neutron energy spectra without directly detecting neutrons. Ions of interest are loaded into a Paul trap surrounded by an array of radiation detectors. Upon decay, recoiling daughter nuclei and emitted particles emerge from the center of the trap with minimal scattering. The neutron energy is then determined from the time-of-flight, and hence momentum, of the recoiling ions. I will explain the details of the technique, and present the results from the most recent experimental campaign at the CARIBU facility at Argonne National Laboratory. This work was supported under contracts DE-NA0000979 (NSSC), DE-AC52-07NA27344 (LLNL), DE-AC02-06CH11357 (ANL), DE-FG02-94ER40834 (U. Maryland), DE-FG02-98ER41086 (Northwestern U.), NSERC, Canada, under Application No. 216974, and DHS.
The dynamical crossover phenomenon in bulk water, confined water and protein hydration water.
Mallamace, Francesco; Corsaro, Carmelo; Baglioni, Piero; Fratini, Emiliano; Chen, Sow-Hsin
2012-02-15
We discuss a phenomenon regarding water that was until recently a subject of scientific controversy, i.e. the dynamical crossover from fragile-to-strong glass-forming material, for both bulk and protein hydration water. Such a crossover is characterized by a temperature T(L) at which significant dynamical changes occur, such as violation of the Stokes-Einstein relation and changes of behaviour of homologous transport parameters such as the density relaxation time and the viscosity. In this respect we will consider carefully the dynamic properties of water-protein systems. More precisely, we will study proteins and their hydration water as far as bulk and confined water. In order to clarify the controversy we will discuss in a comparative way many previous and new experimental data that have emerged using different techniques and molecular dynamic simulation (MD). We point out the reasons for the different dynamical findings from the use of different experimental techniques.
Population growth rates: issues and an application.
Godfray, H Charles J; Rees, Mark
2002-01-01
Current issues in population dynamics are discussed in the context of The Royal Society Discussion Meeting 'Population growth rate: determining factors and role in population regulation'. In particular, different views on the centrality of population growth rates to the study of population dynamics and the role of experiments and theory are explored. Major themes emerging include the role of modern statistical techniques in bringing together experimental and theoretical studies, the importance of long-term experimentation and the need for ecology to have model systems, and the value of population growth rate as a means of understanding and predicting population change. The last point is illustrated by the application of a recently introduced technique, integral projection modelling, to study the population growth rate of a monocarpic perennial plant, its elasticities to different life-history components and the evolution of an evolutionarily stable strategy size at flowering. PMID:12396521
Orbital engineering of nickelates in three-component heterostructures
NASA Astrophysics Data System (ADS)
Disa, Ankit; Kumah, Divine; Malashevich, Andrei; Chen, Hanghui; Ismail-Beigi, Sohrab; Walker, Fred; Ahn, Charles; Specht, Eliot; Arena, Dario
2015-03-01
The orbital configuration of complex oxides dictates the emergence of a wide range of properties, including metal-insulator transitions, interfacial magnetism, and high-temperature superconductivity. In this work, we experimentally demonstrate a novel method for achieving large and tunable orbital polarizations in nickelates. The technique is based on leveraging three-component, atomically layered superlattices to yield a combination of inversion symmetry breaking, charge transfer, and polar distortions. In the system we studied, composed of LaTiO3/LaNiO3/LaAlO3, we use synchrotron x-ray diffraction and spectroscopy to characterize these properties and show that they lead to fully broken orbital degeneracy in the nickelate layer consistent with a single-band Fermi surface. Furthermore, we show that this system is widely tunable and enables quasi-continuous orbital control unachievable by conventional strain and confinement-based approaches. This technique provides an experimentally realizable route for accessing and studying novel orbitally dependent quantum phenomena.
Wind-instrument reflection function measurements in the time domain.
Keefe, D H
1996-04-01
Theoretical and computational analyses of wind-instrument sound production in the time domain have emerged as useful tools for understanding musical instrument acoustics, yet there exist few experimental measurements of the air-column response directly in the time domain. A new experimental, time-domain technique is proposed to measure the reflection function response of woodwind and brass-instrument air columns. This response is defined at the location of sound regeneration in the mouthpiece or double reed. A probe assembly comprised of an acoustic source and microphone is inserted directly into the air column entryway using a foam plug to ensure a leak-free fit. An initial calibration phase involves measurements on a single cylindrical tube of known dimensions. Measurements are presented on an alto saxophone and euphonium. The technique has promise for testing any musical instrument air columns using a single probe assembly and foam plugs over a range of diameters typical of air-column entryways.
An overview of clinical and experimental treatment modalities for port wine stains
Chen, Jennifer K.; Ghasri, Pedram; Aguilar, Guillermo; van Drooge, Anne Margreet; Wolkerstorfer, Albert; Kelly, Kristen M.; Heger, Michal
2014-01-01
Port wine stains (PWS) are the most common vascular malformation of the skin, occurring in 0.3% to 0.5% of the population. Noninvasive laser irradiation with flashlamp-pumped pulsed dye lasers (selective photothermolysis) currently comprises the gold standard treatment of PWS; however, the majority of PWS fail to clear completely after selective photothermolysis. In this review, the clinically used PWS treatment modalities (pulsed dye lasers, alexandrite lasers, neodymium:yttrium-aluminum-garnet lasers, and intense pulsed light) and techniques (combination approaches, multiple passes, and epidermal cooling) are discussed. Retrospective analysis of clinical studies published between 1990 and 2011 was performed to determine therapeutic efficacies for each clinically used modality/technique. In addition, factors that have resulted in the high degree of therapeutic recalcitrance are identified, and emerging experimental treatment strategies are addressed, including the use of photodynamic therapy, immunomodulators, angiogenesis inhibitors, hypobaric pressure, and site-specific pharmaco-laser therapy. PMID:22305042
Protecting against cyber threats in networked information systems
NASA Astrophysics Data System (ADS)
Ertoz, Levent; Lazarevic, Aleksandar; Eilertson, Eric; Tan, Pang-Ning; Dokas, Paul; Kumar, Vipin; Srivastava, Jaideep
2003-07-01
This paper provides an overview of our efforts in detecting cyber attacks in networked information systems. Traditional signature based techniques for detecting cyber attacks can only detect previously known intrusions and are useless against novel attacks and emerging threats. Our current research at the University of Minnesota is focused on developing data mining techniques to automatically detect attacks against computer networks and systems. This research is being conducted as a part of MINDS (Minnesota Intrusion Detection System) project at the University of Minnesota. Experimental results on live network traffic at the University of Minnesota show that the new techniques show great promise in detecting novel intrusions. In particular, during the past few months our techniques have been successful in automatically identifying several novel intrusions that could not be detected using state-of-the-art tools such as SNORT.
Mechanistic Studies in Friction and Wear of Bulk Materials
NASA Astrophysics Data System (ADS)
Sawyer, W. Gregory; Argibay, Nicolas; Burris, David L.; Krick, Brandon A.
2014-07-01
From the context of a contemporary understanding of the phenomenological origins of friction and wear of materials, we review insightful contributions from recent experimental investigations of three classes of materials that exhibit uniquely contrasting tribological behaviors: metals, polymers, and ionic solids. We focus on the past decade of research by the community to better understand the correlations between environment parameters, materials properties, and tribological behavior in systems of increasingly greater complexity utilizing novel synthesis and in situ experimental techniques. In addition to such review, and a half-century after seminal publications on the subject, we present recently acquired evidence linking anisotropy in friction response with anisotropy in wear behavior of crystalline ionic solids as a function of crystallographic orientation. Although the tribological behaviors of metals, polymers, and ionic solids differ widely, it is increasingly more evident that the mechanistic origins (such as fatigue, corrosion, abrasion, and adhesion) are essentially the same. However, we hope to present a clear and compelling argument favoring the prominent and irreplaceable role of in situ experimental techniques as a bridge between fundamental atomistic and molecular processes and emergent behaviors governing tribological contacts.
Susaki, Etsuo A; Ueda, Hiroki R
2016-01-21
Organism-level systems biology aims to identify, analyze, control and design cellular circuits in organisms. Many experimental and computational approaches have been developed over the years to allow us to conduct these studies. Some of the most powerful methods are based on using optical imaging in combination with fluorescent labeling, and for those one of the long-standing stumbling blocks has been tissue opacity. Recently, the solutions to this problem have started to emerge based on whole-body and whole-organ clearing techniques that employ innovative tissue-clearing chemistry. Here, we review these advancements and discuss how combining new clearing techniques with high-performing fluorescent proteins or small molecule tags, rapid volume imaging and efficient image informatics is resulting in comprehensive and quantitative organ-wide, single-cell resolution experimental data. These technologies are starting to yield information on connectivity and dynamics in cellular circuits at unprecedented resolution, and bring us closer to system-level understanding of physiology and diseases of complex mammalian systems. Copyright © 2016 Elsevier Ltd. All rights reserved.
Challinor, Kirsten L; Mond, Jonathan; Stephen, Ian D; Mitchison, Deborah; Stevenson, Richard J; Hay, Phillipa; Brooks, Kevin R
2017-12-01
Although body size and shape misperception (BSSM) is a common feature of anorexia nervosa, bulimia nervosa and muscle dysmorphia, little is known about its underlying neural mechanisms. Recently, a new approach has emerged, based on the long-established non-invasive technique of perceptual adaptation, which allows for inferences about the structure of the neural apparatus responsible for alterations in visual appearance. Here, we describe several recent experimental examples of BSSM, wherein exposure to "extreme" body stimuli causes visual aftereffects of biased perception. The implications of these studies for our understanding of the neural and cognitive representation of human bodies, along with their implications for clinical practice are discussed.
Experimentally evaluating the origin of dilute magnetism in nanomaterials
NASA Astrophysics Data System (ADS)
Pereira, L. M. C.
2017-10-01
Reports of room-temperature ferromagnetism continue to emerge for an ever-growing range of nanomaterials with a small or even vanishing concentration of magnetic atoms. Dilute magnetic semiconductors (DMS) are the most representative class of such materials, but similar magnetic properties have been reported in many others. Challenging our understanding of magnetic order in solids, as well as our ability to experimentally assess it, these remarkable magnetic phenomena have become one of the most controversial topics in magnetism. Various non-intrinsic sources of ferromagnetism (e.g. instrumental artifacts and magnetic contamination) are becoming well documented, and rarely are all of them taken into account when room-temperature ferromagnetism is reported. This topical review is intended to serve as a guide when evaluating to what extent a given data set supports the claim of intrinsic ferromagnetism in dilute nanomaterials. It compiles the most relevant sources of non-intrinsic ferromagnetism which have been reported, as well as guidelines for how to minimize them. It also provides an overview of complementary structural and magnetic characterization techniques which can be combined to provide different levels of scrutiny of the intrinsic nature of experimentally observed ferromagnetism. In particular, it gives some notable examples of how comprehensive studies based on those techniques have led to a remarkably detailed understanding of model DMS materials, with strong evidence of absence of room-temperature ferromagnetism. Although mostly based on DMS research, this review provides a set of guidelines and cautionary notes of broader relevance, including some emerging new fields of dilute nanomagnetism such as magnetically doped 3D topological insulators, 3D Dirac semimetals, and 2D materials.
Nakstad, Anders R; Bredmose, Per P; Sandberg, Mårten
2013-07-26
A large number of techniques and devices for cricothyroidotomy have been developed. In this study, the Portex™ Cricothyroidotomy Kit (PCK, Smiths Medical Ltd, Hythe, UK) was compared with the bougie assisted emergency surgical cricothyrotomy technique (BACT). Twenty air ambulance anaesthesiologists performed emergency cricothyrotomy on a cadaveric porcine airway model using both PCK and BACT. Baseline performance and performance after the intensive training package were recorded. Success rate, time to secured airway and tracheal damage were the primary endpoints, and confidence rating was a secondary endpoint. During baseline testing, success rates for PCK and BACT were 60% and 95%, respectively. Tracheal injury rate with PCK was 60% while no such injury was found in BACT. A lecture was given and skills were trained until the participants were able to perform five consecutive successful procedures with both techniques. In the post-training test, all participants were successful with either technique. The mean time to successful insertion was reduced by 15.7 seconds (from 36.3 seconds to 20.6 seconds, p< 0.001) for PCK and by 7.8 seconds (from 44.9 seconds to 37.1 seconds, p=0.021) for BACT. In the post-training scenario, securing the airway with PCK was significantly faster than with BACT (p<0.001). Post-training tracheal laceration occurred in six (30%) of the PCK procedures and in none of the BACT procedures (p=0.028). Testing the base-line PCK skills of prehospital anaesthesiologists revealed low confidence, sub-optimal performance and a very high failure rate. The BACT technique demonstrated a significantly higher success rate and no tracheal damage. In spite of PCK being a significantly faster technique in the post-training test, the anaesthesiologists still reported a higher confidence in BACT. Limitations of the cadaveric porcine airway may have influenced this study because the airway did not challenge the clinicians with realistic tissue bleeding.
Emerging bacterial pathogens: the past and beyond.
Vouga, M; Greub, G
2016-01-01
Since the 1950s, medical communities have been facing with emerging and reemerging infectious diseases, and emerging pathogens are now considered to be a major microbiologic public health threat. In this review, we focus on bacterial emerging diseases and explore factors involved in their emergence as well as future challenges. We identified 26 major emerging and reemerging infectious diseases of bacterial origin; most of them originated either from an animal and are considered to be zoonoses or from water sources. Major contributing factors in the emergence of these bacterial infections are: (1) development of new diagnostic tools, such as improvements in culture methods, development of molecular techniques and implementation of mass spectrometry in microbiology; (2) increase in human exposure to bacterial pathogens as a result of sociodemographic and environmental changes; and (3) emergence of more virulent bacterial strains and opportunistic infections, especially affecting immunocompromised populations. A precise definition of their implications in human disease is challenging and requires the comprehensive integration of microbiological, clinical and epidemiologic aspects as well as the use of experimental models. It is now urgent to allocate financial resources to gather international data to provide a better understanding of the clinical relevance of these waterborne and zoonotic emerging diseases. Copyright © 2015. Published by Elsevier Ltd.
Biophysics of cadherin adhesion.
Leckband, Deborah; Sivasankar, Sanjeevi
2012-01-01
Since the identification of cadherins and the publication of the first crystal structures, the mechanism of cadherin adhesion, and the underlying structural basis have been studied with a number of different experimental techniques, different classical cadherin subtypes, and cadherin fragments. Earlier studies based on biophysical measurements and structure determinations resulted in seemingly contradictory findings regarding cadherin adhesion. However, recent experimental data increasingly reveal parallels between structures, solution binding data, and adhesion-based biophysical measurements that are beginning to both reconcile apparent differences and generate a more comprehensive model of cadherin-mediated cell adhesion. This chapter summarizes the functional, structural, and biophysical findings relevant to cadherin junction assembly and adhesion. We emphasize emerging parallels between findings obtained with different experimental approaches. Although none of the current models accounts for all of the available experimental and structural data, this chapter discusses possible origins of apparent discrepancies, highlights remaining gaps in current knowledge, and proposes challenges for further study.
Cheng, Gui-Juan; Zhang, Xinhao; Chung, Lung Wa; Xu, Liping; Wu, Yun-Dong
2015-02-11
Understanding the mechanisms of chemical reactions, especially catalysis, has been an important and active area of computational organic chemistry, and close collaborations between experimentalists and theorists represent a growing trend. This Perspective provides examples of such productive collaborations. The understanding of various reaction mechanisms and the insight gained from these studies are emphasized. The applications of various experimental techniques in elucidation of reaction details as well as the development of various computational techniques to meet the demand of emerging synthetic methods, e.g., C-H activation, organocatalysis, and single electron transfer, are presented along with some conventional developments of mechanistic aspects. Examples of applications are selected to demonstrate the advantages and limitations of these techniques. Some challenges in the mechanistic studies and predictions of reactions are also analyzed.
Traffic Management for Emergency Vehicle Priority Based on Visual Sensing.
Nellore, Kapileswar; Hancke, Gerhard P
2016-11-10
Vehicular traffic is endlessly increasing everywhere in the world and can cause terrible traffic congestion at intersections. Most of the traffic lights today feature a fixed green light sequence, therefore the green light sequence is determined without taking the presence of the emergency vehicles into account. Therefore, emergency vehicles such as ambulances, police cars, fire engines, etc. stuck in a traffic jam and delayed in reaching their destination can lead to loss of property and valuable lives. This paper presents an approach to schedule emergency vehicles in traffic. The approach combines the measurement of the distance between the emergency vehicle and an intersection using visual sensing methods, vehicle counting and time sensitive alert transmission within the sensor network. The distance between the emergency vehicle and the intersection is calculated for comparison using Euclidean distance, Manhattan distance and Canberra distance techniques. The experimental results have shown that the Euclidean distance outperforms other distance measurement techniques. Along with visual sensing techniques to collect emergency vehicle information, it is very important to have a Medium Access Control (MAC) protocol to deliver the emergency vehicle information to the Traffic Management Center (TMC) with less delay. Then only the emergency vehicle is quickly served and can reach the destination in time. In this paper, we have also investigated the MAC layer in WSNs to prioritize the emergency vehicle data and to reduce the transmission delay for emergency messages. We have modified the medium access procedure used in standard IEEE 802.11p with PE-MAC protocol, which is a new back off selection and contention window adjustment scheme to achieve low broadcast delay for emergency messages. A VANET model for the UTMS is developed and simulated in NS-2. The performance of the standard IEEE 802.11p and the proposed PE-MAC is analysed in detail. The NS-2 simulation results have shown that the PE-MAC outperforms the IEEE 802.11p in terms of average end-to-end delay, throughput and energy consumption. The performance evaluation results have proven that the proposed PE-MAC prioritizes the emergency vehicle data and delivers the emergency messages to the TMC with less delay compared to the IEEE 802.11p. The transmission delay of the proposed PE-MAC is also compared with the standard IEEE 802.15.4, and Enhanced Back-off Selection scheme for IEEE 802.15.4 protocol [EBSS, an existing protocol to ensure fast transmission of the detected events on the road towards the TMC] and the comparative results have proven the effectiveness of the PE-MAC over them. Furthermore, this research work will provide an insight into the design of an intelligent urban traffic management system for the effective management of emergency vehicles and will help to save lives and property.
Combustion Characterization and Model Fuel Development for Micro-tubular Flame-assisted Fuel Cells.
Milcarek, Ryan J; Garrett, Michael J; Baskaran, Amrish; Ahn, Jeongmin
2016-10-02
Combustion based power generation has been accomplished for many years through a number of heat engine systems. Recently, a move towards small scale power generation and micro combustion as well as development in fuel cell research has created new means of power generation that combine solid oxide fuel cells with open flames and combustion exhaust. Instead of relying upon the heat of combustion, these solid oxide fuel cell systems rely on reforming of the fuel via combustion to generate syngas for electrochemical power generation. Procedures were developed to assess the combustion by-products under a wide range of conditions. While theoretical and computational procedures have been developed for assessing fuel-rich combustion exhaust in these applications, experimental techniques have also emerged. The experimental procedures often rely upon a gas chromatograph or mass spectrometer analysis of the flame and exhaust to assess the combustion process as a fuel reformer and means of heat generation. The experimental techniques developed in these areas have been applied anew for the development of the micro-tubular flame-assisted fuel cell. The protocol discussed in this work builds on past techniques to specify a procedure for characterizing fuel-rich combustion exhaust and developing a model fuel-rich combustion exhaust for use in flame-assisted fuel cell testing. The development of the procedure and its applications and limitations are discussed.
Birgül, Ozlem; Eyüboğlu, B Murat; Ider, Y Ziya
2003-11-07
Magnetic resonance electrical impedance tomography (MR-EIT) is an emerging imaging technique that reconstructs conductivity images using magnetic flux density measurements acquired employing MRI together with conventional EIT measurements. In this study, experimental MR-EIT images from phantoms with conducting and insulator objects are presented. The technique is implemented using the 0.15 T Middle East Technical University MRI system. The dc current method used in magnetic resonance current density imaging is adopted. A reconstruction algorithm based on the sensitivity matrix relation between conductivity and only one component of magnetic flux distribution is used. Therefore, the requirement for object rotation is eliminated. Once the relative conductivity distribution is found, it is scaled using the peripheral voltage measurements to obtain the absolute conductivity distribution. Images of several insulator and conductor objects in saline filled phantoms are reconstructed. The L2 norm of relative error in conductivity values is found to be 13%, 17% and 14% for three different conductivity distributions.
An overview of clinical and experimental treatment modalities for port wine stains.
Chen, Jennifer K; Ghasri, Pedram; Aguilar, Guillermo; van Drooge, Anne Margreet; Wolkerstorfer, Albert; Kelly, Kristen M; Heger, Michal
2012-08-01
Port wine stains (PWS) are the most common vascular malformation of the skin, occurring in 0.3% to 0.5% of the population. Noninvasive laser irradiation with flashlamp-pumped pulsed dye lasers (selective photothermolysis) currently comprises the gold standard treatment of PWS; however, the majority of PWS fail to clear completely after selective photothermolysis. In this review, the clinically used PWS treatment modalities (pulsed dye lasers, alexandrite lasers, neodymium:yttrium-aluminum-garnet lasers, and intense pulsed light) and techniques (combination approaches, multiple passes, and epidermal cooling) are discussed. Retrospective analysis of clinical studies published between 1990 and 2011 was performed to determine therapeutic efficacies for each clinically used modality/technique. In addition, factors that have resulted in the high degree of therapeutic recalcitrance are identified, and emerging experimental treatment strategies are addressed, including the use of photodynamic therapy, immunomodulators, angiogenesis inhibitors, hypobaric pressure, and site-specific pharmaco-laser therapy. Copyright © 2011 American Academy of Dermatology, Inc. Published by Mosby, Inc. All rights reserved.
Ultrasonic nondestructive evaluation, microstructure, and mechanical property interrelations
NASA Technical Reports Server (NTRS)
Vary, A.
1984-01-01
Ultrasonic techniques for mechanical property characterizations are reviewed and conceptual models are advanced for explaining and interpreting the empirically based results. At present, the technology is generally empirically based and is emerging from the research laboratory. Advancement of the technology will require establishment of theoretical foundations for the experimentally observed interrelations among ultrasonic measurements, mechanical properties, and microstructure. Conceptual models are applied to ultrasonic assessment of fracture toughness to illustrate an approach for predicting correlations found among ultrasonic measurements, microstructure, and mechanical properties.
Effects of pupil filter patterns in line-scan focal modulation microscopy
NASA Astrophysics Data System (ADS)
Shen, Shuhao; Pant, Shilpa; Chen, Rui; Chen, Nanguang
2018-03-01
Line-scan focal modulation microscopy (LSFMM) is an emerging imaging technique that affords high imaging speed and good optical sectioning at the same time. We present a systematic investigation into optimal design of the pupil filter for LSFMM in an attempt to achieve the best performance in terms of spatial resolutions, optical sectioning, and modulation depth. Scalar diffraction theory was used to compute light propagation and distribution in the system and theoretical predictions on system performance, which were then compared with experimental results.
Behavioural cues of reproductive status in seahorses Hippocampus abdominalis.
Whittington, C M; Musolf, K; Sommer, S; Wilson, A B
2013-07-01
A method is described to assess the reproductive status of male Hippocampus abdominalis on the basis of behavioural traits. The non-invasive nature of this technique minimizes handling stress and reduces sampling requirements for experimental work. It represents a useful tool to assist researchers in sample collection for studies of reproduction and development in viviparous syngnathids, which are emerging as important model species. © 2013 The Authors. Journal of Fish Biology © 2013 The Fisheries Society of the British Isles.
Experimental study on internal cooling system in hard turning of HCWCI using CBN tools
NASA Astrophysics Data System (ADS)
Ravi, A. M.; Murigendrappa, S. M.
2018-04-01
In recent times, hard turning became most emerging technique in manufacturing processes, especially to cut high hard materials like high chrome white cast iron (HCWCI). Use of Cubic boron nitride (CBN), pCBN and Carbide tools are most appropriate to shear the metals but are uneconomical. Since hard turning carried out in dry condition, lowering the tool wear by minimizing tool temperature is the only solution. Study reveals, no effective cooling systems are available so for in order to enhance the tool life of the cutting tools and to improve machinability characteristics. The detrimental effect of cutting parameters on cutting temperature is generally controlled by proper selections. The objective of this paper is to develop a new cooling system to control tool tip temperature, thereby minimizing the cutting forces and the tool wear rates. The materials chosen for this work was HCWCI and cutting tools are CBN inserts. Intricate cavities were made on the periphery of the tool holder for easy flow of cold water. Taguchi techniques were adopted to carry out the experimentations. The experimental results confirm considerable reduction in the cutting forces and tool wear rates.
Mante, Pierre-Adrien; Lehmann, Sebastian; Anttu, Nicklas; Dick, Kimberly A; Yartsev, Arkady
2016-08-10
We have developed and demonstrated an experimental method, based on the picosecond acoustics technique, to perform nondestructive complete mechanical characterization of nanowires, that is, the determination of the complete elasticity tensor. By means of femtosecond pump-probe spectroscopy, coherent acoustic phonons were generated in an ensemble of nanowires and their dynamics was resolved. Specific phonon modes were identified and the detection mechanism was addressed via wavelength dependent experiments. We calculated the exact phonon dispersion relation of the nanowires by fitting the experimentally observed frequencies, thus allowing the extraction of the complete elasticity tensor. The elasticity tensor and the nanowire diameter were determined for zinc blende GaAs nanowires and were found to be in a good agreement with literature data and independent measurements. Finally, we have applied this technique to characterize wurtzite GaAs nanowires, a metastable phase in bulk, for which no experimental values of elastic constants are currently available. Our results agree well with previous first principle calculations. The proposed approach to the complete and nondestructive mechanical characterization of nanowires will allow the efficient mechanical study of new crystal phases emerging in nanostructures, as well as size-dependent properties of nanostructured materials.
Characterizing nonconstant instrumental variance in emerging miniaturized analytical techniques.
Noblitt, Scott D; Berg, Kathleen E; Cate, David M; Henry, Charles S
2016-04-07
Measurement variance is a crucial aspect of quantitative chemical analysis. Variance directly affects important analytical figures of merit, including detection limit, quantitation limit, and confidence intervals. Most reported analyses for emerging analytical techniques implicitly assume constant variance (homoskedasticity) by using unweighted regression calibrations. Despite the assumption of constant variance, it is known that most instruments exhibit heteroskedasticity, where variance changes with signal intensity. Ignoring nonconstant variance results in suboptimal calibrations, invalid uncertainty estimates, and incorrect detection limits. Three techniques where homoskedasticity is often assumed were covered in this work to evaluate if heteroskedasticity had a significant quantitative impact-naked-eye, distance-based detection using paper-based analytical devices (PADs), cathodic stripping voltammetry (CSV) with disposable carbon-ink electrode devices, and microchip electrophoresis (MCE) with conductivity detection. Despite these techniques representing a wide range of chemistries and precision, heteroskedastic behavior was confirmed for each. The general variance forms were analyzed, and recommendations for accounting for nonconstant variance discussed. Monte Carlo simulations of instrument responses were performed to quantify the benefits of weighted regression, and the sensitivity to uncertainty in the variance function was tested. Results show that heteroskedasticity should be considered during development of new techniques; even moderate uncertainty (30%) in the variance function still results in weighted regression outperforming unweighted regressions. We recommend utilizing the power model of variance because it is easy to apply, requires little additional experimentation, and produces higher-precision results and more reliable uncertainty estimates than assuming homoskedasticity. Copyright © 2016 Elsevier B.V. All rights reserved.
Jet Substructure at the Large Hadron Collider : Experimental Review
DOE Office of Scientific and Technical Information (OSTI.GOV)
Asquith, Lily; Campanelli, Mario; Delitzsch, Chris
Jet substructure has emerged to play a central role at the Large Hadron Collider (LHC), where it has provided numerous innovative new ways to search for new physics and to probe the Standard Model, particularly in extreme regions of phase space. In this article we focus on a review of the development and use of state-of-the-art jet substructure techniques by the ATLAS and CMS experiments. ALICE and LHCb have been probing fragmentation functions since the start of the LHC and have also recently started studying other jet substructure techniques. It is likely that in the near future all LHC collaborationsmore » will make significant use of jet substructure and grooming techniques. Much of the work in this field in recent years has been galvanized by the Boost Workshop Series, which continues to inspire fruitful collaborations between experimentalists and theorists. We hope that this review will prove a useful introduction and reference to experimental aspects of jet substructure at the LHC. A companion overview of recent progress in theory and machine learning approaches is given in 1709.04464, the complete review will be submitted to Reviews of Modern Physics.« less
Phase retrieval with tunable phase transfer function based on the transport of intensity equation
NASA Astrophysics Data System (ADS)
Martinez-Carranza, J.; Stepien, P.; Kozacki, T.
2017-06-01
Recovering phase information with Deterministic approaches as the Transport of Intensity Equation (TIE) has recently emerged as an alternative tool to the interferometric techniques because it is experimentally easy to implement and provides fast and accurate results. Moreover, the potential of employing partially coherent illumination (PCI) in such techniques allow obtaining high quality phase reconstructions providing that the estimation of the corresponding Phase Transfer Function (PTF) is carried out correctly. Hence, accurate estimation of the PTF requires that the physical properties of the optical system are well known. Typically, these parameters are assumed constant in all the set of measurements, which might not be optimal. In this work, we proposed the use of an amplitude Spatial Light Modulator (aSLM) for tuning the degree of coherence of the optical system. The aSLM will be placed at the Fourier plane of the optical system, and then, band pass filters will be displayed. This methodology will perform amplitude modulation of the propagated field and as a result, the state of coherence of the optical system can be modified. Theoretical and experimental results that validate our proposed technique will be shown.
NASA Astrophysics Data System (ADS)
Scheffold, Frank
2014-08-01
To characterize the structural and dynamic properties of soft materials and small particles, information on the relevant mesoscopic length scales is required. Such information is often obtained from traditional static and dynamic light scattering (SLS/DLS) experiments in the single scattering regime. In many dense systems, however, these powerful techniques frequently fail due to strong multiple scattering of light. Here I will discuss some experimental innovations that have emerged over the last decade. New methods such as 3D static and dynamic light scattering (3D LS) as well as diffusing wave spectroscopy (DWS) can cover a much extended range of experimental parameters ranging from dilute polymer solutions, colloidal suspensions to extremely opaque viscoelastic emulsions.
DNA-based construction at the nanoscale: emerging trends and applications
NASA Astrophysics Data System (ADS)
Lourdu Xavier, P.; Chandrasekaran, Arun Richard
2018-02-01
The field of structural DNA nanotechnology has evolved remarkably—from the creation of artificial immobile junctions to the recent DNA-protein hybrid nanoscale shapes—in a span of about 35 years. It is now possible to create complex DNA-based nanoscale shapes and large hierarchical assemblies with greater stability and predictability, thanks to the development of computational tools and advances in experimental techniques. Although it started with the original goal of DNA-assisted structure determination of difficult-to-crystallize molecules, DNA nanotechnology has found its applications in a myriad of fields. In this review, we cover some of the basic and emerging assembly principles: hybridization, base stacking/shape complementarity, and protein-mediated formation of nanoscale structures. We also review various applications of DNA nanostructures, with special emphasis on some of the biophysical applications that have been reported in recent years. In the outlook, we discuss further improvements in the assembly of such structures, and explore possible future applications involving super-resolved fluorescence, single-particle cryo-electron (cryo-EM) and x-ray free electron laser (XFEL) nanoscopic imaging techniques, and in creating new synergistic designer materials.
DNA-based construction at the nanoscale: emerging trends and applications.
Xavier, P Lourdu; Chandrasekaran, Arun Richard
2018-02-09
The field of structural DNA nanotechnology has evolved remarkably-from the creation of artificial immobile junctions to the recent DNA-protein hybrid nanoscale shapes-in a span of about 35 years. It is now possible to create complex DNA-based nanoscale shapes and large hierarchical assemblies with greater stability and predictability, thanks to the development of computational tools and advances in experimental techniques. Although it started with the original goal of DNA-assisted structure determination of difficult-to-crystallize molecules, DNA nanotechnology has found its applications in a myriad of fields. In this review, we cover some of the basic and emerging assembly principles: hybridization, base stacking/shape complementarity, and protein-mediated formation of nanoscale structures. We also review various applications of DNA nanostructures, with special emphasis on some of the biophysical applications that have been reported in recent years. In the outlook, we discuss further improvements in the assembly of such structures, and explore possible future applications involving super-resolved fluorescence, single-particle cryo-electron (cryo-EM) and x-ray free electron laser (XFEL) nanoscopic imaging techniques, and in creating new synergistic designer materials.
NASA Astrophysics Data System (ADS)
Secchi, Eleonora; Marbach, Sophie; Siria, Alessandro; Bocquet, Lyderic
2015-11-01
Over the last decade, nanometric sized channels have been intensively investigated since new model of fluid transport are expected due to the flow confinement at the nanometric scale. Nanoconfinement generates new phenomena, such as superfast flows in carbon nanotubes and slippage over smooth surfaces. However, a major challenge of nanofluidics lies in fabricating nanoscale fluidic devices and developing new velocimetry techniques able to measure flow rates down to femtoL/s. In this work we report the experimental study of the velocity fields generated by pressure driven flow from glass nanochannel with a diameter ranging from 1 μm to 100nm. The flow emerging from these channels can be described by the classical Landau-Squire solution of the Navier-Stokes equation for a point jet. We show that due to the peculiarity of this flow, it can be used as an efficient probe to characterize the permeability of nanochannels. Velocity field is measured experimentally seeding the fluid in the reservoir with 500 nm Polystyrene particles and measuring the velocity with a standard PIV algorithm. Predictions are tested for nanochannels of several dimensions and supported by ionic current measurement. This demonstrates that this technique is a powerful tool to characterize the flow through nanochannels. We finally apply this method to the measurement of the flow emerging from a single carbon nanotube inserted in the nanochannels and present first data of permeability measurement through a single nanotube.
Simon, S; Smith, A J
2014-03-01
Significant advances in our understanding of the biological processes involved in tooth development and repair at the cellular and molecular levels have underpinned the newly emerging area of regenerative endodontics. Development of treatment protocols based on exploiting the natural wound healing properties of the dental pulp and applying tissue engineering principles has allowed reporting of case series showing preservation of tissue vitality and apexogenesis. To review current case series reporting regenerative endodontics. Current treatment approaches tend to stimulate more reparative than regenerative responses in respect of the new tissue generated, which often does not closely resemble the physiological structure of dentine-pulp. However, despite these biological limitations, such techniques appear to offer significant promise for improved treatment outcomes. Improved biological outcomes will likely emerge from the many experimental studies being reported and will further contribute to improvements in clinical treatment protocols.
Mapping Social Interactions: The Science of Proxemics.
McCall, Cade
Interpersonal distance and gaze provide a wealth of information during face-to-face social interactions. These "proxemic" behaviors offer a window into everyday social cognition by revealing interactants' affective states (e.g., interpersonal attitudes) and cognitive responses (e.g., social attention). Here we provide a brief overview of the social psychological literature in this domain. We focus on new techniques for experimentally manipulating and measuring proxemics, including the use of immersive virtual environments and digital motion capture. We also discuss ways in which these approaches can be integrated with psychophysiological and neuroimaging techniques. Throughout, we argue that contemporary proxemics research provides psychology and neuroscience with a means to study social cognition and behavior as they naturally emerge and unfold in vivo.
Heike Kamerlingh Onnes: Master of Experimental Technique and Quantitative Research
NASA Astrophysics Data System (ADS)
Reif-Acherman, Simón
Heike Kamerlingh Onnes (1853-1926), born a century and a half ago, was a major protagonist in the so-called Second Golden Age of Dutch Science. He devoted his career to the emerging field of low-temperature physics. His particular concern was to test the theories of his older compatriot Johannes Diderik van der Waals (1837-1923) by creating a style of research that was characterized by meticulous planning, precise measurement, and constant improvement of techniques and instruments. He made numerous contributions to low-temperature physics, but I focus on his liquefaction of helium, for which he received the Nobel Prize in Physics for 1913, and on his discovery of superconductivity. He became known internationally as le gentleman du zéro absolu.
Traffic Management for Emergency Vehicle Priority Based on Visual Sensing
Nellore, Kapileswar; Hancke, Gerhard P.
2016-01-01
Vehicular traffic is endlessly increasing everywhere in the world and can cause terrible traffic congestion at intersections. Most of the traffic lights today feature a fixed green light sequence, therefore the green light sequence is determined without taking the presence of the emergency vehicles into account. Therefore, emergency vehicles such as ambulances, police cars, fire engines, etc. stuck in a traffic jam and delayed in reaching their destination can lead to loss of property and valuable lives. This paper presents an approach to schedule emergency vehicles in traffic. The approach combines the measurement of the distance between the emergency vehicle and an intersection using visual sensing methods, vehicle counting and time sensitive alert transmission within the sensor network. The distance between the emergency vehicle and the intersection is calculated for comparison using Euclidean distance, Manhattan distance and Canberra distance techniques. The experimental results have shown that the Euclidean distance outperforms other distance measurement techniques. Along with visual sensing techniques to collect emergency vehicle information, it is very important to have a Medium Access Control (MAC) protocol to deliver the emergency vehicle information to the Traffic Management Center (TMC) with less delay. Then only the emergency vehicle is quickly served and can reach the destination in time. In this paper, we have also investigated the MAC layer in WSNs to prioritize the emergency vehicle data and to reduce the transmission delay for emergency messages. We have modified the medium access procedure used in standard IEEE 802.11p with PE-MAC protocol, which is a new back off selection and contention window adjustment scheme to achieve low broadcast delay for emergency messages. A VANET model for the UTMS is developed and simulated in NS-2. The performance of the standard IEEE 802.11p and the proposed PE-MAC is analysed in detail. The NS-2 simulation results have shown that the PE-MAC outperforms the IEEE 802.11p in terms of average end-to-end delay, throughput and energy consumption. The performance evaluation results have proven that the proposed PE-MAC prioritizes the emergency vehicle data and delivers the emergency messages to the TMC with less delay compared to the IEEE 802.11p. The transmission delay of the proposed PE-MAC is also compared with the standard IEEE 802.15.4, and Enhanced Back-off Selection scheme for IEEE 802.15.4 protocol [EBSS, an existing protocol to ensure fast transmission of the detected events on the road towards the TMC] and the comparative results have proven the effectiveness of the PE-MAC over them. Furthermore, this research work will provide an insight into the design of an intelligent urban traffic management system for the effective management of emergency vehicles and will help to save lives and property. PMID:27834924
Mechanical impedance measurements for improved cost-effective process monitoring
NASA Astrophysics Data System (ADS)
Clopet, Caroline R.; Pullen, Deborah A.; Badcock, Rodney A.; Ralph, Brian; Fernando, Gerard F.; Mahon, Steve W.
1999-06-01
The aerospace industry has seen a considerably growth in composite usage over the past ten years, especially with the development of cost effective manufacturing techniques such as Resin Transfer Molding and Resin Infusion under Flexible Tooling. The relatively high cost of raw material and conservative processing schedules has limited their growth further in non-aerospace technologies. In-situ process monitoring has been explored for some time as a means to improving the cost efficiency of manufacturing with dielectric spectroscopy and optical fiber sensors being the two primary techniques developed to date. A new emerging technique is discussed here making use of piezoelectric wafers with the ability to sense not only aspects of resin flow but also to detect the change in properties of the resin as it cures. Experimental investigations to date have shown a correlation between mechanical impedance measurements and the mechanical properties of cured epoxy systems with potential for full process monitoring.
Machine-Learning Techniques Applied to Antibacterial Drug Discovery
Durrant, Jacob D.; Amaro, Rommie E.
2014-01-01
The emergence of drug-resistant bacteria threatens to catapult humanity back to the pre-antibiotic era. Even now, multi-drug-resistant bacterial infections annually result in millions of hospital days, billions in healthcare costs, and, most importantly, tens of thousands of lives lost. As many pharmaceutical companies have abandoned antibiotic development in search of more lucrative therapeutics, academic researchers are uniquely positioned to fill the resulting vacuum. Traditional high-throughput screens and lead-optimization efforts are expensive and labor intensive. Computer-aided drug discovery techniques, which are cheaper and faster, can accelerate the identification of novel antibiotics in an academic setting, leading to improved hit rates and faster transitions to pre-clinical and clinical testing. The current review describes two machine-learning techniques, neural networks and decision trees, that have been used to identify experimentally validated antibiotics. We conclude by describing the future directions of this exciting field. PMID:25521642
O'Rourke, Matthew B; Padula, Matthew P
2016-01-01
Since emerging in the late 19(th) century, formaldehyde fixation has become a standard method for preservation of tissues from clinical samples. The advantage of formaldehyde fixation is that fixed tissues can be stored at room temperature for decades without concern for degradation. This has led to the generation of huge tissue banks containing thousands of clinically significant samples. Here we review techniques for proteomic analysis of formalin-fixed, paraffin-embedded (FFPE) tissue samples with a specific focus on the methods used to extract and break formaldehyde crosslinks. We also discuss an error-of-interpretation associated with the technique known as "antigen retrieval." We have discovered that this term has been mistakenly applied to two disparate molecular techniques; therefore, we argue that a terminology change is needed to ensure accurate reporting of experimental results. Finally, we suggest that more investigation is required to fully understand the process of formaldehyde fixation and its subsequent reversal.
Volumetric velocimetry for fluid flows
NASA Astrophysics Data System (ADS)
Discetti, Stefano; Coletti, Filippo
2018-04-01
In recent years, several techniques have been introduced that are capable of extracting 3D three-component velocity fields in fluid flows. Fast-paced developments in both hardware and processing algorithms have generated a diverse set of methods, with a growing range of applications in flow diagnostics. This has been further enriched by the increasingly marked trend of hybridization, in which the differences between techniques are fading. In this review, we carry out a survey of the prominent methods, including optical techniques and approaches based on medical imaging. An overview of each is given with an example of an application from the literature, while focusing on their respective strengths and challenges. A framework for the evaluation of velocimetry performance in terms of dynamic spatial range is discussed, along with technological trends and emerging strategies to exploit 3D data. While critical challenges still exist, these observations highlight how volumetric techniques are transforming experimental fluid mechanics, and that the possibilities they offer have just begun to be explored.
NASA Astrophysics Data System (ADS)
Remington, Bruce A.
2014-10-01
Over the past 3 decades there has been an exponential increase in the newly emerging field of matter at extreme states of deformation and compression. This has been due to the confluence of new experimental facilities, new experimental techniques, new theory, and new multiscale simulation techniques. Regimes of science and research hitherto thought out of reach in terrestrial settings are now being accessed routinely. High energy lasers and pulsed power facilities are accessing high pressure macroscopic states of matter, and next generation light sources combined with smaller drive lasers are probing the quantum response of matter at the atomistic level. Combined, this gives multiscale experimental access of the properties and dynamics of matter from femtoseconds to microseconds and from kilobars to gigabars of pressure. There are a multitude of new regimes of science and research that these new developments make possible. Examples include planetary formation dynamics, asteroid and meteor impact dynamics, space hardware response to hypervelocity interplanetary dust impacts, reactor component response to prolonged exposure to radiation damage, advanced research into light weight armor, and capsule dynamics in inertial confinement fusion (ICF). I will review highlights and advances in this rapidly developing field of science and research, touching on experiments at a wide range of facilities (NIF, Z, Omega, Jupiter, Trident, Vulcan, Orion, LULI, LIL, Gekko, Shenguang, LCLS, DCS). I will also review a wide variety of sophisticated new experimental techniques being developed and new developments in theory and multiscale modeling. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
Engineering topological defect patterns of Bose condensates in shaken optical lattices
NASA Astrophysics Data System (ADS)
Feng, Lei; Clark, Logan W.; Gaj, Anita; Chin, Cheng
2017-04-01
Topological defects emerge and play an essential role in the dynamics of systems undergoing continuous, symmetry-breaking phase transitions. Here, we study the topological defects (domain walls) which form when a Bose condensate in a shaken optical lattice undergoes a quantum phase transition and separates into domains of superfluid with finite momentum. Here, we experimentally demonstrate the ability to control the pattern of domain walls using a digital micromirror device. We further explore implementations of this technique to study dynamics near the phase transition and the evolution of topological defects.
Lapierre-Landry, Maryse; Tucker-Schwartz, Jason M.; Skala, Melissa C.
2016-01-01
Photothermal OCT (PT-OCT) is an emerging molecular imaging technique that occupies a spatial imaging regime between microscopy and whole body imaging. PT-OCT would benefit from a theoretical model to optimize imaging parameters and test image processing algorithms. We propose the first analytical PT-OCT model to replicate an experimental A-scan in homogeneous and layered samples. We also propose the PT-CLEAN algorithm to reduce phase-accumulation and shadowing, two artifacts found in PT-OCT images, and demonstrate it on phantoms and in vivo mouse tumors. PMID:27446693
Pereira, Jorge; Câmara, José S; Colmsjö, Anders; Abdel-Rehim, Mohamed
2014-06-01
Sample preparation is an important analytical step regarding the isolation and concentration of desired components from complex matrices and greatly influences their reliable and accurate analysis and data quality. It is the most labor-intensive and error-prone process in analytical methodology and, therefore, may influence the analytical performance of the target analytes quantification. Many conventional sample preparation methods are relatively complicated, involving time-consuming procedures and requiring large volumes of organic solvents. Recent trends in sample preparation include miniaturization, automation, high-throughput performance, on-line coupling with analytical instruments and low-cost operation through extremely low volume or no solvent consumption. Micro-extraction techniques, such as micro-extraction by packed sorbent (MEPS), have these advantages over the traditional techniques. This paper gives an overview of MEPS technique, including the role of sample preparation in bioanalysis, the MEPS description namely MEPS formats (on- and off-line), sorbents, experimental and protocols, factors that affect the MEPS performance, and the major advantages and limitations of MEPS compared with other sample preparation techniques. We also summarize MEPS recent applications in bioanalysis. Copyright © 2014 John Wiley & Sons, Ltd.
Tomographic Aperture-Encoded Particle Tracking Velocimetry: A New Approach to Volumetric PIV
NASA Astrophysics Data System (ADS)
Troolin, Dan; Boomsma, Aaron; Lai, Wing; Pothos, Stamatios; Fluid Mechanics Research Instruments Team
2016-11-01
Volumetric velocity fields are useful in a wide variety of fluid mechanics applications. Several types of three-dimensional imaging methods have been used in the past to varying degrees of success, for example, 3D PTV (Maas et al., 1993), DDPIV (Peireira et al., 2006), Tomographic PIV (Elsinga, 2006), and V3V (Troolin and Longmire, 2009), among others. Each of these techniques has shown advantages and disadvantages in different areas. With the advent of higher resolution and lower noise cameras with higher stability levels, new techniques are emerging that combine the advantages of the existing techniques. This talk describes a new technique called Tomographic Aperture-Encoded Particle Tracking Velocimetry (TAPTV), in which segmented triangulation and diameter tolerance are used to achieve three-dimensional particle tracking with extremely high particle densities (on the order of ppp = 0.2 or higher) without the drawbacks normally associated with ghost particles (for example in TomoPIV). The results are highly spatially-resolved data with very fast processing times. A detailed explanation of the technique as well as plots, movies, and experimental considerations will be discussed.
Photoacoustic spectroscopic studies of polycyclic aromatic hydrocarbons
NASA Astrophysics Data System (ADS)
Zaidi, Zahid H.; Kumar, Pardeep; Garg, R. K.
1999-02-01
Because of their involvement in environmental pollutants, in carcinogenic activity, plastics, pharmaceuticals, synthesis of some laser dyes and presence in interstellar space etc., Polycyclic aromatic hydrocarbons (PAHs) are important. As their structure and properties can be varied systematically, they form a beautiful class of molecules for experimental and quantum chemical investigations. These molecules are being studied for last several years by using conventional spectroscopy. In recent years, Photoacoustic (PA) spectroscopy has emerged as a new non-destructive technique with unique capability and sensitivity. The PA effect is the process of generation of acoustic waves in a sample resulting from the absorption of photons. This technique not only reveals non- radiative transitions but also provides information about forbidden singlet-triplet transitions which are not observed normally by the conventional spectroscopy. The present paper deals with the spectroscopic studies of some PAH molecules by PA spectroscopy in the region 250 - 400 nm. The CNDO/S-CI method is used to calculate the electronic transitions with the optimized geometries. A good agreement is found between the experimental and calculated results.
Vrahatis, Aristidis G; Rapti, Angeliki; Sioutas, Spyros; Tsakalidis, Athanasios
2017-01-01
In the era of Systems Biology and growing flow of omics experimental data from high throughput techniques, experimentalists are in need of more precise pathway-based tools to unravel the inherent complexity of diseases and biological processes. Subpathway-based approaches are the emerging generation of pathway-based analysis elucidating the biological mechanisms under the perspective of local topologies onto a complex pathway network. Towards this orientation, we developed PerSub, a graph-based algorithm which detects subpathways perturbed by a complex disease. The perturbations are imprinted through differentially expressed and co-expressed subpathways as recorded by RNA-seq experiments. Our novel algorithm is applied on data obtained from a real experimental study and the identified subpathways provide biological evidence for the brain aging.
Siegel, Nathan A; Kobayashi, Leo; Dunbar-Viveiros, Jennifer A; Devine, Jeffrey; Al-Rasheed, Rakan S; Gardiner, Fenwick G; Olsson, Krister; Lai, Stella; Jones, Mark S; Dannecker, Max; Overly, Frank L; Gosbee, John W; Portelli, David C; Jay, Gregory D
2015-06-01
Patient safety during emergency department procedural sedation (EDPS) can be difficult to study. Investigators sought to delineate and experimentally assess EDPS performance and safety practices of senior-level emergency medicine residents through in situ simulation. Study sessions used 2 pilot-tested EDPS scenarios with critical action checklists, institutional forms, embedded probes, and situational awareness questionnaires. An experimental informatics system was separately developed for bedside EDPS process guidance. Postgraduate year 3 and 4 subjects completed both scenarios in randomized order; only experimental subjects were provided with the experimental system during second scenarios. Twenty-four residents were recruited into a control group (n = 12; 6.2 ± 7.4 live EDPS experience) and experimental group (n = 12; 11.3 ± 8.2 live EDPS experience [P = 0.10]). Critical actions for EDPS medication selection, induction, and adverse event recognition with resuscitation were correctly performed by most subjects. Presedation evaluations, sedation rescue preparation, equipment checks, time-outs, and documentation were frequently missed. Time-outs and postsedation assessments increased during second scenarios in the experimental group. Emergency department procedural sedation safety probe detection did not change across scenarios in either group. Situational awareness scores were 51% ± 7% for control group and 58% ± 12% for experimental group. Subjects using the experimental system completed more time-outs and scored higher Simulation EDPS Safety Composite Scores, although without comprehensive improvements in EDPS practice or safety. Study simulations delineated EDPS and assessed safety behaviors in senior emergency medicine residents, who exhibited the requisite medical knowledge base and procedural skill set but lacked some nontechnical skills that pertain to emergency department microsystem functions and patient safety. The experimental system exhibited limited impact only on in-simulation time-out compliance.
Summary of: Regenerative endodontics.
Clark, Stephen J
2014-03-01
Significant advances in our understanding of the biological processes involved in tooth development and repair at the cellular and molecular levels have underpinned the newly emerging area of regenerative endodontics. Development of treatment protocols based on exploiting the natural wound healing properties of the dental pulp and applying tissue engineering principles has allowed reporting of case series showing preservation of tissue vitality and apexogenesis. To review current case series reporting regenerative endodontics. Current treatment approaches tend to stimulate more reparative than regenerative responses in respect of the new tissue generated, which often does not closely resemble the physiological structure of dentine-pulp. However, despite these biological limitations, such techniques appear to offer significant promise for improved treatment outcomes. Improved biological outcomes will likely emerge from the many experimental studies being reported and will further contribute to improvements in clinical treatment protocols.
Hosseinabadi, Reza; Karampourian, Arezou; Beiranvand, Shoorangiz; Pournia, Yadollah
2013-10-01
Quality circles, as a participatory management technique, offer one alternative for dealing with frustration and discontent of today's workers. This study was conducted to investigate the effect of implementation of quality circles on nurses' quality of work-life and job satisfaction. In this study, two emergency medical services (EMS) of Hamedan province were selected and randomly assigned as the experimental and control groups. After the experimental group was trained and quality circles were established in this group, the levels of quality of work-life and job satisfaction were measured in the two groups. Then, the statistical analyses were performed using t-test. After the intervention, the results showed significant differences between the scores of motivational factors (p=0.001), the total scores of job satisfaction (p=0.003), and the scores of some quality of work life (QWL) conceptual categories including the use and development of capacities (p=0.008), the total space of life (p=0.003), and the total scores of QWL (p=0.031) in the experimental group compared to those in the control group. This study confirms the effectiveness of quality circles in improving quality of work-life and job satisfaction of nurses working in EMS, and offers their application as a management method that can be used by EMS managers. Copyright © 2012 Elsevier Ltd. All rights reserved.
Blood oxygenation level-dependent MRI for assessment of renal oxygenation
Neugarten, Joel; Golestaneh, Ladan
2014-01-01
Blood oxygen level-dependent magnetic resonance imaging (BOLD MRI) has recently emerged as an important noninvasive technique to assess intrarenal oxygenation under physiologic and pathophysiologic conditions. Although this tool represents a major addition to our armamentarium of methodologies to investigate the role of hypoxia in the pathogenesis of acute kidney injury and progressive chronic kidney disease, numerous technical limitations confound interpretation of data derived from this approach. BOLD MRI has been utilized to assess intrarenal oxygenation in numerous experimental models of kidney disease and in human subjects with diabetic and nondiabetic chronic kidney disease, acute kidney injury, renal allograft rejection, contrast-associated nephropathy, and obstructive uropathy. However, confidence in conclusions based on data derived from BOLD MRI measurements will require continuing advances and technical refinements in the use of this technique. PMID:25473304
Development of the nervus terminalis: origin and migration.
Whitlock, Kathleen E
2004-09-01
The origin of the nervus terminalis is one of the least well understood developmental events involved in generating the cranial ganglia of the forebrain in vertebrate animals. This cranial nerve forms at the formidable interface of the anteriormost limits of migrating cranial neural crest cells, the terminal end of the neural tube and the differentiating olfactory and adenohypophyseal placodes. The complex cellular interactions that give rise to the various structures associated with the sensory placode (olfactory) and endocrine placode (adenohypophysis) surround and engulf this enigmatic cranial nerve. The tortured history of nervus terminalis development (see von Bartheld, this issue, pages 13-24) reflects the lack of consensus on the origin (or origins), as well as the experimental difficulties in uncovering the origin, of the nervus terminalis. Recent technical advances have allowed us to make headway in understanding the origin(s) of this nerve. The emergence of the externally fertilized zebrafish embryo as a model system for developmental biology and genetics has shed new light on this century-old problem. Coupled with new developmental models are techniques that allow us to trace lineage, visualize gene expression, and genetically ablate cells, adding to our experimental tools with which to follow up on studies provided by our scientific predecessors. Through these techniques, a picture is emerging in which the origin of at least a subset of the nervus terminalis cells lies in the cranial neural crest. In this review, the data surrounding this finding will be discussed in light of recent findings on neural crest and placode origins. Copyright 2004 Wiley-Liss, Inc.
A secure and robust information hiding technique for covert communication
NASA Astrophysics Data System (ADS)
Parah, S. A.; Sheikh, J. A.; Hafiz, A. M.; Bhat, G. M.
2015-08-01
The unprecedented advancement of multimedia and growth of the internet has made it possible to reproduce and distribute digital media easier and faster. This has given birth to information security issues, especially when the information pertains to national security, e-banking transactions, etc. The disguised form of encrypted data makes an adversary suspicious and increases the chance of attack. Information hiding overcomes this inherent problem of cryptographic systems and is emerging as an effective means of securing sensitive data being transmitted over insecure channels. In this paper, a secure and robust information hiding technique referred to as Intermediate Significant Bit Plane Embedding (ISBPE) is presented. The data to be embedded is scrambled and embedding is carried out using the concept of Pseudorandom Address Vector (PAV) and Complementary Address Vector (CAV) to enhance the security of the embedded data. The proposed ISBPE technique is fully immune to Least Significant Bit (LSB) removal/replacement attack. Experimental investigations reveal that the proposed technique is more robust to various image processing attacks like JPEG compression, Additive White Gaussian Noise (AWGN), low pass filtering, etc. compared to conventional LSB techniques. The various advantages offered by ISBPE technique make it a good candidate for covert communication.
Experimental Photogrammetric Techniques Used on Five Full-Scale Aircraft Crash Tests
NASA Technical Reports Server (NTRS)
Littell, Justin D.
2016-01-01
Between 2013 and 2015, full-scale crash tests were conducted on five aircraft at the Landing and Impact Research Facility (LandIR) at NASA Langley Research Center (LaRC). Two tests were conducted on CH-46E airframes as part of the Transport Rotorcraft Airframe Crash Testbed (TRACT) project, and three tests were conduced on Cessna 172 aircraft as part of the Emergency Locator Transmitter Survivability and Reliability (ELTSAR) project. Each test served to evaluate a variety of crashworthy systems including: seats, occupants, restraints, composite energy absorbing structures, and Emergency Locator Transmitters. As part of each test, the aircraft were outfitted with a variety of internal and external cameras that were focused on unique aspects of the crash event. A subset of three camera was solely used in the acquisition of photogrammetric test data. Examples of this data range from simple two-dimensional marker tracking for the determination of aircraft impact conditions to entire full-scale airframe deformation to markerless tracking of Anthropomorphic Test Devices (ATDs, a.k.a. crash test dummies) during the crash event. This report describes and discusses the techniques used and implications resulting from the photogrammetric data acquired from each of the five tests.
van Ruymbeke, E; Lee, H; Chang, T; Nikopoulou, A; Hadjichristidis, N; Snijkers, F; Vlassopoulos, D
2014-07-21
An emerging challenge in polymer physics is the quantitative understanding of the influence of a macromolecular architecture (i.e., branching) on the rheological response of entangled complex polymers. Recent investigations of the rheology of well-defined architecturally complex polymers have determined the composition in the molecular structure and identified the role of side-products in the measured samples. The combination of different characterization techniques, experimental and/or theoretical, represents the current state-of-the-art. Here we review this interdisciplinary approach to molecular rheology of complex polymers, and show the importance of confronting these different tools for ensuring an accurate characterization of a given polymeric sample. We use statistical tools in order to relate the information available from the synthesis protocols of a sample and its experimental molar mass distribution (typically obtained from size exclusion chromatography), and hence obtain precise information about its structural composition, i.e. enhance the existing sensitivity limit. We critically discuss the use of linear rheology as a reliable quantitative characterization tool, along with the recently developed temperature gradient interaction chromatography. The latter, which has emerged as an indispensable characterization tool for branched architectures, offers unprecedented sensitivity in detecting the presence of different molecular structures in a sample. Combining these techniques is imperative in order to quantify the molecular composition of a polymer and its consequences on the macroscopic properties. We validate this approach by means of a new model asymmetric comb polymer which was synthesized anionically. It was thoroughly characterized and its rheology was carefully analyzed. The main result is that the rheological signal reveals fine molecular details, which must be taken into account to fully elucidate the viscoelastic response of entangled branched polymers. It is important to appreciate that, even optimal model systems, i.e., those synthesized with high-vacuum anionic methods, need thorough characterization via a combination of techniques. Besides helping to improve synthetic techniques, this methodology will be significant in fine-tuning mesoscopic tube-based models and addressing outstanding issues such as the quantitative description of the constraint release mechanism.
Direct experimental determination of the topological winding number of skyrmions in Cu2OSeO3
NASA Astrophysics Data System (ADS)
Zhang, S. L.; van der Laan, G.; Hesjedal, T.
2017-02-01
The mathematical concept of topology has brought about significant advantages that allow for a fundamental understanding of the underlying physics of a system. In magnetism, the topology of spin order manifests itself in the topological winding number which plays a pivotal role for the determination of the emergent properties of a system. However, the direct experimental determination of the topological winding number of a magnetically ordered system remains elusive. Here, we present a direct relationship between the topological winding number of the spin texture and the polarized resonant X-ray scattering process. This relationship provides a one-to-one correspondence between the measured scattering signal and the winding number. We demonstrate that the exact topological quantities of the skyrmion material Cu2OSeO3 can be directly experimentally determined this way. This technique has the potential to be applicable to a wide range of materials, allowing for a direct determination of their topological properties.
Gimenez-Pinto, Vianney; Ye, Fangfu; Mbanga, Badel; Selinger, Jonathan V.; Selinger, Robin L. B.
2017-01-01
Various experimental and theoretical studies demonstrate that complex stimulus-responsive out-of-plane distortions such as twist of different chirality, emergence of cones, simple and anticlastic bending can be engineered and pre-programmed in a liquid crystalline rubbery material given a well-controlled director microstructure. Via 3-d finite element simulation studies, we demonstrate director-encoded chiral shape actuation in thin-film nematic polymer networks under external stimulus. Furthermore, we design two complex director fields with twisted nematic domains and nematic disclinations that encode a pattern of folds for an auto-origami box. This actuator will be flat at a reference nematic state and form four well-controlled bend distortions as orientational order changes. Device fabrication is applicable via current experimental techniques. These results are in qualitative agreement with theoretical predictions, provide insight into experimental observations, and demonstrate the value of finite element methods at the continuum level for designing and engineering liquid crystal polymeric devices. PMID:28349949
Microbial Communities as Experimental Units
DAY, MITCH D.; BECK, DANIEL; FOSTER, JAMES A.
2011-01-01
Artificial ecosystem selection is an experimental technique that treats microbial communities as though they were discrete units by applying selection on community-level properties. Highly diverse microbial communities associated with humans and other organisms can have significant impacts on the health of the host. It is difficult to find correlations between microbial community composition and community-associated diseases, in part because it may be impossible to define a universal and robust species concept for microbes. Microbial communities are composed of potentially thousands of unique populations that evolved in intimate contact, so it is appropriate in many situations to view the community as the unit of analysis. This perspective is supported by recent discoveries using metagenomics and pangenomics. Artificial ecosystem selection experiments can be costly, but they bring the logical rigor of biological model systems to the emerging field of microbial community analysis. PMID:21731083
Economical analysis of saturation mutagenesis experiments
Acevedo-Rocha, Carlos G.; Reetz, Manfred T.; Nov, Yuval
2015-01-01
Saturation mutagenesis is a powerful technique for engineering proteins, metabolic pathways and genomes. In spite of its numerous applications, creating high-quality saturation mutagenesis libraries remains a challenge, as various experimental parameters influence in a complex manner the resulting diversity. We explore from the economical perspective various aspects of saturation mutagenesis library preparation: We introduce a cheaper and faster control for assessing library quality based on liquid media; analyze the role of primer purity and supplier in libraries with and without redundancy; compare library quality, yield, randomization efficiency, and annealing bias using traditional and emergent randomization schemes based on mixtures of mutagenic primers; and establish a methodology for choosing the most cost-effective randomization scheme given the screening costs and other experimental parameters. We show that by carefully considering these parameters, laboratory expenses can be significantly reduced. PMID:26190439
Human recognition in a video network
NASA Astrophysics Data System (ADS)
Bhanu, Bir
2009-10-01
Video networks is an emerging interdisciplinary field with significant and exciting scientific and technological challenges. It has great promise in solving many real-world problems and enabling a broad range of applications, including smart homes, video surveillance, environment and traffic monitoring, elderly care, intelligent environments, and entertainment in public and private spaces. This paper provides an overview of the design of a wireless video network as an experimental environment, camera selection, hand-off and control, anomaly detection. It addresses challenging questions for individual identification using gait and face at a distance and present new techniques and their comparison for robust identification.
2016-01-01
The development of thoracoscopy has more than one hundred years of history since Jacobaeus described the first procedure in 1910. He used the thoracoscope to lyse adhesions in tuberculosis patients. This technique was adopted throughout Europe in the early decades of the 20th century for minor and diagnostic procedures. It is only in the last two decades that interest in minimally invasive thoracic surgery was reintroduced by two key technological improvements: the development of better thoracoscopic cameras and the availability of endoscopic linear mechanical staplers. From these advances the first video-assisted thoracic surgery (VATS) major pulmonary resection was performed in 1992. In the following years, the progress of VATS was slow until studies showing clear benefits of VATS over open surgery started to be published. From that point on, the technique spread throughout the world and variations of the technique started to emerge. The information available on internet, live surgery events and experimental courses has contributed to the rapid learning of minimally invasive surgery during the last decade. While initially slow to catch on, the traditional multi-port approach has evolved into a uniportal approach that mimics open surgical vantage points while utilizing a non-rib-spreading single small incision. The early period of uniportal VATS development was focused on minor procedures until 2010 with the adoption of the technique for major pulmonary resections. Currently, experts in the technique are able to use uniportal VATS to encompass the most complex procedures such as bronchial sleeve, vascular reconstructions or carinal resections. In contrast, non-intubated and awake thoracic surgery techniques, described since the early history of thoracic surgery, peaked in the decades before the invention of the double lumen endotracheal tube and have failed to gain widespread acceptance following their re-emergence over a decade ago thanks to the improvements in VATS techniques. PMID:27134833
Kunstler, Breanne E; Cook, Jill L; Freene, Nicole; Finch, Caroline F; Kemp, Joanne L; O'Halloran, Paul D; Gaida, James E
2018-06-01
Physiotherapists promote physical activity as part of their practice. This study reviewed the behaviour change techniques physiotherapists use when promoting physical activity in experimental and observational studies. Systematic review of experimental and observational studies. Twelve databases were searched using terms related to physiotherapy and physical activity. We included experimental studies evaluating the efficacy of physiotherapist-led physical activity interventions delivered to adults in clinic-based private practice and outpatient settings to individuals with, or at risk of, non-communicable diseases. Observational studies reporting the techniques physiotherapists use when promoting physical activity were also included. The behaviour change techniques used in all studies were identified using the Behaviour Change Technique Taxonomy. The behaviour change techniques appearing in efficacious and inefficacious experimental interventions were compared using a narrative approach. Twelve studies (nine experimental and three observational) were retained from the initial search yield of 4141. Risk of bias ranged from low to high. Physiotherapists used seven behaviour change techniques in the observational studies, compared to 30 behaviour change techniques in the experimental studies. Social support (unspecified) was the most frequently identified behaviour change technique across both settings. Efficacious experimental interventions used more behaviour change techniques (n=29) and functioned in more ways (n=6) than did inefficacious experimental interventions (behaviour change techniques=10 and functions=1). Physiotherapists use a small number of behaviour change techniques. Less behaviour change techniques were identified in observational studies compared to experimental studies, suggesting physiotherapists use less BCTs clinically than experimentally. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.
Agbangla, Nounagnon F; Audiffren, Michel; Albinet, Cédric T
2017-09-01
The cognitive neuroscience of aging is a growing and stimulating research area. The development of neuroimaging techniques in the past two decades has considerably increased our understanding of the brain mechanisms that might underlie cognitive performance and resulting changes due to normal aging. Beside traditional metabolic neuroimaging techniques, such as Positron Emission Tomography and functional Magnetic Resonance Imaging, near infrared spectroscopy (NIRS), an optical imaging technique allowing to monitor real-time cerebral blood oxygenation, has gained recent interest in this field. The aim of the present review paper, after briefly presenting the NIRS technique, is to review and to summarize the recent results of neuroimaging studies using this technique in the field of cognitive aging. The reviewed literature shows that, despite low spatial resolution and cerebral depth penetration, this technique provides consistent findings on the reduced hemodynamic activity as a function of chronological age, mainly in the prefrontal cortex. Important moderators of brain hemodynamics, such as cognitive load, subjects' characteristics and experimental conditions, for which the NIRS technique is sensitive, are discussed. Strengths and weaknesses of functional NIRS in the field of cognitive aging are presented and finally, novel perspectives of research are proposed. Copyright © 2017 Elsevier B.V. All rights reserved.
NASA Astrophysics Data System (ADS)
Albertsen, Anders N.; Szymański, Jan K.; Pérez-Mercader, Juan
2017-01-01
Giant micrometer sized vesicles are of obvious interest to the natural sciences as well as engineering, having potential application in fields ranging from drug delivery to synthetic biology. Their formation often requires elaborate experimental techniques and attempts to obtain giant vesicles from chemical media in a one-pot fashion have so far led to much smaller nanoscale structures. Here we show that a tailored medium undergoing controlled radical polymerization is capable of forming giant polymer vesicles. Using a protocol which allows for an aqueous reaction under mild conditions, we observe the macroscale consequences of amphiphilic polymer synthesis and the resulting molecular self-assembly using fluorescence microscopy. The polymerization process is photoinitiated by blue light granting complete control of the reaction, including on the microscope stage. The self-assembly process leads to giant vesicles with radii larger than 10 microns, exhibiting several emergent properties, including periodic growth and collapse as well as phototaxis.
Influence of emergency physician's tying technique on knot security.
Batra, E K; Franz, D A; Towler, M A; Rodeheaver, G T; Thacker, J G; Zimmer, C A; Edlich, R F
1992-01-01
The purpose of this study was to determine the influence of emergency physician's tying technique on knot security using 2-0 and 4-0 monofilament and multifilament nylon sutures. Using an Instron Tensile Tester and a portable tensiometer, knot security was achieved with these sutures using four-throw square knots (1 = 1 = 1 = 1). After didactic and psychomotor skill training, medical students were taught to construct the four-throw square knot using either a two-hand tie or an instrument tie. Using the portable tensiometer, their knot tying techniques were judged to be superior to those used by emergency physicians. The emergency physician's faulty technique can easily be corrected by didactic information and psychomotor skill training.
String theory--the physics of string-bending and other electric guitar techniques.
Grimes, David Robert
2014-01-01
Electric guitar playing is ubiquitous in practically all modern music genres. In the hands of an experienced player, electric guitars can sound as expressive and distinct as a human voice. Unlike other more quantised instruments where pitch is a discrete function, guitarists can incorporate micro-tonality and, as a result, vibrato and sting-bending are idiosyncratic hallmarks of a player. Similarly, a wide variety of techniques unique to the electric guitar have emerged. While the mechano-acoustics of stringed instruments and vibrating strings are well studied, there has been comparatively little work dedicated to the underlying physics of unique electric guitar techniques and strings, nor the mechanical factors influencing vibrato, string-bending, fretting force and whammy-bar dynamics. In this work, models for these processes are derived and the implications for guitar and string design discussed. The string-bending model is experimentally validated using a variety of strings and vibrato dynamics are simulated. The implications of these findings on the configuration and design of guitars is also discussed.
A Review of Computational Methods for Finding Non-Coding RNA Genes
Abbas, Qaisar; Raza, Syed Mansoor; Biyabani, Azizuddin Ahmed; Jaffar, Muhammad Arfan
2016-01-01
Finding non-coding RNA (ncRNA) genes has emerged over the past few years as a cutting-edge trend in bioinformatics. There are numerous computational intelligence (CI) challenges in the annotation and interpretation of ncRNAs because it requires a domain-related expert knowledge in CI techniques. Moreover, there are many classes predicted yet not experimentally verified by researchers. Recently, researchers have applied many CI methods to predict the classes of ncRNAs. However, the diverse CI approaches lack a definitive classification framework to take advantage of past studies. A few review papers have attempted to summarize CI approaches, but focused on the particular methodological viewpoints. Accordingly, in this article, we summarize in greater detail than previously available, the CI techniques for finding ncRNAs genes. We differentiate from the existing bodies of research and discuss concisely the technical merits of various techniques. Lastly, we review the limitations of ncRNA gene-finding CI methods with a point-of-view towards the development of new computational tools. PMID:27918472
String Theory - The Physics of String-Bending and Other Electric Guitar Techniques
Grimes, David Robert
2014-01-01
Electric guitar playing is ubiquitous in practically all modern music genres. In the hands of an experienced player, electric guitars can sound as expressive and distinct as a human voice. Unlike other more quantised instruments where pitch is a discrete function, guitarists can incorporate micro-tonality and, as a result, vibrato and sting-bending are idiosyncratic hallmarks of a player. Similarly, a wide variety of techniques unique to the electric guitar have emerged. While the mechano-acoustics of stringed instruments and vibrating strings are well studied, there has been comparatively little work dedicated to the underlying physics of unique electric guitar techniques and strings, nor the mechanical factors influencing vibrato, string-bending, fretting force and whammy-bar dynamics. In this work, models for these processes are derived and the implications for guitar and string design discussed. The string-bending model is experimentally validated using a variety of strings and vibrato dynamics are simulated. The implications of these findings on the configuration and design of guitars is also discussed. PMID:25054880
Somatic Embryogenesis: Still a Relevant Technique in Citrus Improvement.
Omar, Ahmad A; Dutt, Manjul; Gmitter, Frederick G; Grosser, Jude W
2016-01-01
The genus Citrus contains numerous fresh and processed fruit cultivars that are economically important worldwide. New cultivars are needed to battle industry threatening diseases and to create new marketing opportunities. Citrus improvement by conventional methods alone has many limitations that can be overcome by applications of emerging biotechnologies, generally requiring cell to plant regeneration. Many citrus genotypes are amenable to somatic embryogenesis, which became a key regeneration pathway in many experimental approaches to cultivar improvement. This chapter provides a brief history of plant somatic embryogenesis with focus on citrus, followed by a discussion of proven applications in biotechnology-facilitated citrus improvement techniques, such as somatic hybridization, somatic cybridization, genetic transformation, and the exploitation of somaclonal variation. Finally, two important new protocols that feature plant regeneration via somatic embryogenesis are provided: protoplast transformation and Agrobacterium-mediated transformation of embryogenic cell suspension cultures.
From experimental imaging techniques to virtual embryology.
Weninger, Wolfgang J; Tassy, Olivier; Darras, Sébastien; Geyer, Stefan H; Thieffry, Denis
2004-01-01
Modern embryology increasingly relies on descriptive and functional three dimensional (3D) and four dimensional (4D) analysis of physically, optically, or virtually sectioned specimens. To cope with the technical requirements, new methods for high detailed in vivo imaging, as well as the generation of high resolution digital volume data sets for the accurate visualisation of transgene activity and gene product presence, in the context of embryo morphology, were recently developed and are under construction. These methods profoundly change the scientific applicability, appearance and style of modern embryo representations. In this paper, we present an overview of the emerging techniques to create, visualise and administrate embryo representations (databases, digital data sets, 3-4D embryo reconstructions, models, etc.), and discuss the implications of these new methods on the work of modern embryologists, including, research, teaching, the selection of specific model organisms, and potential collaborators.
Non-thermal plasma technologies: new tools for bio-decontamination.
Moreau, M; Orange, N; Feuilloley, M G J
2008-01-01
Bacterial control and decontamination are crucial to industrial safety assessments. However, most recently developed materials are not compatible with standard heat sterilization treatments. Advanced oxidation processes, and particularly non-thermal plasmas, are emerging and promising technologies for sanitation because they are both efficient and cheap. The applications of non-thermal plasma to bacterial control remain poorly known for several reasons: this technique was not developed for biological applications and most of the literature is in the fields of physics and chemistry. Moreover, the diversity of the devices and complexity of the plasmas made any general evaluation of the potential of the technique difficult. Finally, no experimental equipment for non-thermal plasma sterilization is commercially available and reference articles for microbiologists are rare. The present review aims to give an overview of the principles of action and applications of plasma technologies in biodecontamination.
Systems Biology in Immunology – A Computational Modeling Perspective
Germain, Ronald N.; Meier-Schellersheim, Martin; Nita-Lazar, Aleksandra; Fraser, Iain D. C.
2011-01-01
Systems biology is an emerging discipline that combines high-content, multiplexed measurements with informatic and computational modeling methods to better understand biological function at various scales. Here we present a detailed review of the methods used to create computational models and conduct simulations of immune function, We provide descriptions of the key data gathering techniques employed to generate the quantitative and qualitative data required for such modeling and simulation and summarize the progress to date in applying these tools and techniques to questions of immunological interest, including infectious disease. We include comments on what insights modeling can provide that complement information obtained from the more familiar experimental discovery methods used by most investigators and why quantitative methods are needed to eventually produce a better understanding of immune system operation in health and disease. PMID:21219182
Neural electrical activity and neural network growth.
Gafarov, F M
2018-05-01
The development of central and peripheral neural system depends in part on the emergence of the correct functional connectivity in its input and output pathways. Now it is generally accepted that molecular factors guide neurons to establish a primary scaffold that undergoes activity-dependent refinement for building a fully functional circuit. However, a number of experimental results obtained recently shows that the neuronal electrical activity plays an important role in the establishing of initial interneuronal connections. Nevertheless, these processes are rather difficult to study experimentally, due to the absence of theoretical description and quantitative parameters for estimation of the neuronal activity influence on growth in neural networks. In this work we propose a general framework for a theoretical description of the activity-dependent neural network growth. The theoretical description incorporates a closed-loop growth model in which the neural activity can affect neurite outgrowth, which in turn can affect neural activity. We carried out the detailed quantitative analysis of spatiotemporal activity patterns and studied the relationship between individual cells and the network as a whole to explore the relationship between developing connectivity and activity patterns. The model, developed in this work will allow us to develop new experimental techniques for studying and quantifying the influence of the neuronal activity on growth processes in neural networks and may lead to a novel techniques for constructing large-scale neural networks by self-organization. Copyright © 2018 Elsevier Ltd. All rights reserved.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Xie, Qingge; Song, Gian; Gorti, Sarma B.
Bragg-edge imaging, which is also known as neutron radiography, has recently emerged as a novel crystalline characterization technique. Modelling of this novel technique by incorporating various features of the underlying microstructure (including the crystallographic texture, the morphological texture, and the grain size) of the material remains a subject of considerable research and development. In this paper, Inconel 718 samples made by additive manufacturing were investigated by neutron diffraction and neutron radiography techniques. The specimen features strong morphological and crystallographic textures and a highly heterogeneous microstructure. A 3D statistical full-field model is introduced by taking details of the microstructure into accountmore » to understand the experimental neutron radiography results. The Bragg-edge imaging and the total cross section were calculated based on the neutron transmission physics. A good match was obtained between the model predictions and experimental results at different incident beam angles with respect to the sample build direction. The current theoretical approach has the ability to incorporate 3D spatially resolved microstructural heterogeneity information and shows promise in understanding the 2D neutron radiography of bulk samples. With further development to incorporate the heterogeneity in lattice strain in the model, it can be used as a powerful tool in the future to better understand the neutron radiography data.« less
Xie, Qingge; Song, Gian; Gorti, Sarma B.; ...
2018-02-21
Bragg-edge imaging, which is also known as neutron radiography, has recently emerged as a novel crystalline characterization technique. Modelling of this novel technique by incorporating various features of the underlying microstructure (including the crystallographic texture, the morphological texture, and the grain size) of the material remains a subject of considerable research and development. In this paper, Inconel 718 samples made by additive manufacturing were investigated by neutron diffraction and neutron radiography techniques. The specimen features strong morphological and crystallographic textures and a highly heterogeneous microstructure. A 3D statistical full-field model is introduced by taking details of the microstructure into accountmore » to understand the experimental neutron radiography results. The Bragg-edge imaging and the total cross section were calculated based on the neutron transmission physics. A good match was obtained between the model predictions and experimental results at different incident beam angles with respect to the sample build direction. The current theoretical approach has the ability to incorporate 3D spatially resolved microstructural heterogeneity information and shows promise in understanding the 2D neutron radiography of bulk samples. With further development to incorporate the heterogeneity in lattice strain in the model, it can be used as a powerful tool in the future to better understand the neutron radiography data.« less
Systematic Molecular Phenotyping: A Path Toward Precision Emergency Medicine?
Limkakeng, Alexander T; Monte, Andrew A; Kabrhel, Christopher; Puskarich, Michael; Heitsch, Laura; Tsalik, Ephraim L; Shapiro, Nathan I
2016-10-01
Precision medicine is an emerging approach to disease treatment and prevention that considers variability in patient genes, environment, and lifestyle. However, little has been written about how such research impacts emergency care. Recent advances in analytical techniques have made it possible to characterize patients in a more comprehensive and sophisticated fashion at the molecular level, promising highly individualized diagnosis and treatment. Among these techniques are various systematic molecular phenotyping analyses (e.g., genomics, transcriptomics, proteomics, and metabolomics). Although a number of emergency physicians use such techniques in their research, widespread discussion of these approaches has been lacking in the emergency care literature and many emergency physicians may be unfamiliar with them. In this article, we briefly review the underpinnings of such studies, note how they already impact acute care, discuss areas in which they might soon be applied, and identify challenges in translation to the emergency department (ED). While such techniques hold much promise, it is unclear whether the obstacles to translating their findings to the ED will be overcome in the near future. Such obstacles include validation, cost, turnaround time, user interface, decision support, standardization, and adoption by end-users. © 2016 by the Society for Academic Emergency Medicine.
Systematic Molecular Phenotyping: A Path Towards Precision Emergency Medicine?
Limkakeng, Alexander T.; Monte, Andrew; Kabrhel, Christopher; Puskarich, Michael; Heitsch, Laura; Tsalik, Ephraim L.; Shapiro, Nathan I.
2016-01-01
Precision medicine is an emerging approach to disease treatment and prevention that considers variability in patient genes, environment, and lifestyle. However, little has been written about how such research impacts emergency care. Recent advances in analytical techniques have made it possible to characterize patients in a more comprehensive and sophisticated fashion at the molecular level, promising highly individualized diagnosis and treatment. Among these techniques are various systematic molecular phenotyping analyses (e.g., genomics, transcriptomics, proteomics, and metabolomics). Although a number of emergency physicians use such techniques in their research, widespread discussion of these approaches has been lacking in the emergency care literature and many emergency physicians may be unfamiliar with them. In this article, we briefly review the underpinnings of such studies, note how they already impact acute care, discuss areas in which they might soon be applied, and identify challenges in translation to the emergency department. While such techniques hold much promise, it is unclear whether the obstacles to translating their findings to the emergency department will be overcome in the near future. Such obstacles include validation, cost, turnaround time, user interface, decision support, standardization, and adoption by end users. PMID:27288269
Molecular Imaging of Experimental Abdominal Aortic Aneurysms
Ramaswamy, Aneesh K.; Hamilton, Mark; Joshi, Rucha V.; Kline, Benjamin P.; Li, Rui; Wang, Pu; Goergen, Craig J.
2013-01-01
Current laboratory research in the field of abdominal aortic aneurysm (AAA) disease often utilizes small animal experimental models induced by genetic manipulation or chemical application. This has led to the use and development of multiple high-resolution molecular imaging modalities capable of tracking disease progression, quantifying the role of inflammation, and evaluating the effects of potential therapeutics. In vivo imaging reduces the number of research animals used, provides molecular and cellular information, and allows for longitudinal studies, a necessity when tracking vessel expansion in a single animal. This review outlines developments of both established and emerging molecular imaging techniques used to study AAA disease. Beyond the typical modalities used for anatomical imaging, which include ultrasound (US) and computed tomography (CT), previous molecular imaging efforts have used magnetic resonance (MR), near-infrared fluorescence (NIRF), bioluminescence, single-photon emission computed tomography (SPECT), and positron emission tomography (PET). Mouse and rat AAA models will hopefully provide insight into potential disease mechanisms, and the development of advanced molecular imaging techniques, if clinically useful, may have translational potential. These efforts could help improve the management of aneurysms and better evaluate the therapeutic potential of new treatments for human AAA disease. PMID:23737735
Emergency department management of shoulder dystocia.
Del Portal, Daniel A; Horn, Amanda E; Vilke, Gary M; Chan, Theodore C; Ufberg, Jacob W
2014-03-01
Precipitous obstetric deliveries can occur outside of the labor and delivery suite, often in the emergency department (ED). Shoulder dystocia is an obstetric emergency with significant risk of adverse outcome. To review multiple techniques for managing a shoulder dystocia in the ED. We review various techniques and approaches for achieving delivery in the setting of shoulder dystocia. These include common maneuvers, controversial interventions, and interventions of last resort. Emergency physicians should be familiar with multiple techniques for managing a shoulder dystocia to reduce the chances of fetal and maternal morbidity and mortality. Copyright © 2014 Elsevier Inc. All rights reserved.
Amat-Valero, M; Calero-Torralbo, M A; Valera, F
2013-09-01
Understanding the population dynamics and co-evolution of host–parasite systems requires detailed knowledge of their phenology which, in turn, requires a deep knowledge of the effect of abiotic factors on the life cycles of organisms. Temperature is known to be a key environmental influence that participates in the regulation of diapause. Yet, not much is known about the effect of temperature on the free-living stages of true parasites and how it may influence host–parasite interactions. Here we experimentally study the effect of ambient temperature on overwintering pupae of Carnus hemapterus (Diptera, Carnidae), an ectoparasitic fly of various bird species. We also test whether chilling is a prerequisite for completion of diapause in this species. In the course of three winter seasons we experimentally exposed carnid pupae from nests of various host species to spring temperatures with and without chilling and recorded the emergence patterns in experimental and control groups. Experimental groups showed an advanced emergence date, a lower emergence rate and, consequently, a protracted emergence period. Chilling had no obvious effect on the start of emergence but it did advance the mean emergence date, shortened the length of the emergence period when compared with the control treatment and increased the emergence rate when compared with the spring treatment. This study identifies an environmental cue, namely temperature during the free-living stage, affecting the emergence of a widespread parasite and demonstrates the plasticity of diapause in this parasite. Our findings are of potential significance in understanding host–parasite interactions.
Carey, Rachel N.; McDermott, Daragh T.; Sarma, Kiran M.
2013-01-01
The existing empirical research exploring the impact of threat appeals on driver behavior has reported inconsistent findings. In an effort to provide an up-to-date synthesis of the experimental findings, meta-analytic techniques were employed to examine the impact of threat-based messages on fear arousal and on lab-based indices of driving behavior. Experimental studies (k = 13, N = 3044), conducted between 1990 and 2011, were included in the analyses. The aims of the current analysis were (a) to examine whether or not the experimental manipulations had a significant impact on evoked fear, (b) to examine the impact of threat appeals on three distinct indices of driving, and (c) to identify moderators and mediators of the relationship between fear and driving outcomes. Large effects emerged for the level of fear evoked, with experimental groups reporting increased fear arousal in comparison to control groups (r = .64, n = 619, p<.01). The effect of threat appeals on driving outcomes, however, was not significant (r = .03, p = .17). This analysis of the experimental literature indicates that threat appeals can lead to increased fear arousal, but do not appear to have the desired impact on driving behavior. We discuss these findings in the context of threat-based road safety campaigns and future directions for experimental research in this area. PMID:23690955
Carey, Rachel N; McDermott, Daragh T; Sarma, Kiran M
2013-01-01
The existing empirical research exploring the impact of threat appeals on driver behavior has reported inconsistent findings. In an effort to provide an up-to-date synthesis of the experimental findings, meta-analytic techniques were employed to examine the impact of threat-based messages on fear arousal and on lab-based indices of driving behavior. Experimental studies (k = 13, N = 3044), conducted between 1990 and 2011, were included in the analyses. The aims of the current analysis were (a) to examine whether or not the experimental manipulations had a significant impact on evoked fear, (b) to examine the impact of threat appeals on three distinct indices of driving, and (c) to identify moderators and mediators of the relationship between fear and driving outcomes. Large effects emerged for the level of fear evoked, with experimental groups reporting increased fear arousal in comparison to control groups (r = .64, n = 619, p<.01). The effect of threat appeals on driving outcomes, however, was not significant (r = .03, p = .17). This analysis of the experimental literature indicates that threat appeals can lead to increased fear arousal, but do not appear to have the desired impact on driving behavior. We discuss these findings in the context of threat-based road safety campaigns and future directions for experimental research in this area.
Sizemore, Kayla M; Olmstead, Spencer B
2017-01-01
Research on consensual nonmonogamy (CNM) has increased over the past decade. However, willingness to engage in CNM is an understudied phenomenon within this body of literature. Little research has examined the correlates of this aspect of CNM or focused on individuals in the developmental period of emerging adulthood. This study used multigroup structural equation modeling (SEM) to test a conceptual model of emerging adults' (ages 18 to 29; N = 890) willingness to engage in CNM. Results indicated that emerging adult experimentation/possibilities, sexual identity exploration, and permissive attitudes toward casual sex were all related to willingness to engage in CNM. Results also showed that the pathway from emerging adult experimentation/possibilities to willingness to engage in CNM was differentially mediated across gender. Specifically, for women there was an indirect (and positive) pathway from experimentation/possibilities to willingness to engage in CNM through sexual identity exploration. For men there was an indirect (and positive) pathway from experimentation/possibilities to willingness to engage in CNM through permissive attitudes toward casual sex. Implications for future studies on CNM among emerging adults are discussed.
Novel techniques for optical performance monitoring in optical systems
NASA Astrophysics Data System (ADS)
Ku, Yuen Ching
The tremendous increase of data traffic in the worldwide Internet has driven the rapid development of optical networks to migrate from numerous point-to-point links towards meshed, transparent optical networks with dynamically routed light paths. This increases the need for appropriate network supervision methods. In view of this, optical performance monitoring (OPM) has emerged as an indispensable element for the quality assurance of an optical network. This thesis is devoted to the proposal of several new and accurate techniques to monitor different optical impairments so as to enhance proper network management. When the optical signal is carried on fiber links with optical amplifiers, the accumulated amplified spontaneous emission (ASE) noise will result in erroneous detection of the received signals. The first part of the thesis presents a novel, simple, and robust in-band optical signal to noise ratio (OSNR) monitoring technique using phase modulator embedded fiber loop mirror (PM-FLM). This technique measures the in-band OSNR accurately by observing the output power of a fiber loop mirror filter, where the transmittance is adjusted by an embedded phase modulator driven by a low-frequency periodic signal. The robustness against polarization mode dispersion, chromatic dispersion, bit-rate, and partially polarized noise is experimentally demonstrated. Chromatic dispersion (CD) is due to the fact that light with different frequencies travel at different speeds inside fiber. It causes pulse spreading and intersymbol interference (ISI) which would severely degrade the transmission performance. By feeding a signal into a fiber loop which consists of a high-birefringence (Hi-Bi) fiber, we experimentally show that the amount of experienced dispersion can be deduced from the RF power at a specific selected frequency which is determined by the length of the Hi-Bi fiber. Experimental results show that this technique can provide high monitoring resolution and dynamic range. Polarization mode dispersion (PMD) splits an optical pulse into two orthogonally polarized pulses traveling along the fiber at different speeds, causing crosstalk and ISI. The third part of the thesis demonstrates two different PMD monitoring schemes. The first one is based on the analysis of frequency-resolved state-of-polarization (SOP) rotation, with signal spectrum broadened by self-phase modulation (SPM) effect. Experimental results show that the use of broadened signal spectrum induced by SPM not only relaxes the filter requirement and reduces the computational complexity, but also improves the estimation accuracy, and extends the monitoring range of the pulsewidth. The second one is based on the delay-tap asynchronous waveform sampling technique. By examining the statistical distribution of the measured scatter plot, unambiguous PMD measurement range up to 50% of signal bit-period is demonstrated. The final part of the thesis focuses on the monitoring of alignment status between the pulse carver and data modulator in an optical system. We again employ the two-tap asynchronous sampling technique to perform such kind of monitoring in RZ-OOK transmission system. Experimental results show that both the misalignment direction and magnitude can be successfully determined. Besides, we propose and experimentally demonstrate the use of off-center optical filtering technique to capture the amount of spectrum broadening induced by the misalignment between the pulse-carver and the data modulator in RZ-DPSK transmission system. The same technique was also applied to monitor the synchronization between the old and the new data in synchronized phase re-modulation (SPRM) system.
Xiong, Zhenjie; Sun, Da-Wen; Pu, Hongbin; Gao, Wenhong; Dai, Qiong
2017-03-04
With improvement in people's living standards, many people nowadays pay more attention to quality and safety of meat. However, traditional methods for meat quality and safety detection and evaluation, such as manual inspection, mechanical methods, and chemical methods, are tedious, time-consuming, and destructive, which cannot meet the requirements of modern meat industry. Therefore, seeking out rapid, non-destructive, and accurate inspection techniques is important for the meat industry. In recent years, a number of novel and noninvasive imaging techniques, such as optical imaging, ultrasound imaging, tomographic imaging, thermal imaging, and odor imaging, have emerged and shown great potential in quality and safety assessment. In this paper, a detailed overview of advanced applications of these emerging imaging techniques for quality and safety assessment of different types of meat (pork, beef, lamb, chicken, and fish) is presented. In addition, advantages and disadvantages of each imaging technique are also summarized. Finally, future trends for these emerging imaging techniques are discussed, including integration of multiple imaging techniques, cost reduction, and developing powerful image-processing algorithms.
Rejniak, Katarzyna A.; Gerlee, Philip
2013-01-01
Summary In this review we summarize our recent efforts using mathematical modeling and computation to simulate cancer invasion, with a special emphasis on the tumor microenvironment. We consider cancer progression as a complex multiscale process and approach it with three single-cell based mathematical models that examine the interactions between tumor microenvironment and cancer cells at several scales. The models exploit distinct mathematical and computational techniques, yet they share core elements and can be compared and/or related to each other. The overall aim of using mathematical models is to uncover the fundamental mechanisms that lend cancer progression its direction towards invasion and metastasis. The models effectively simulate various modes of cancer cell adaptation to the microenvironment in a growing tumor. All three point to a general mechanism underlying cancer invasion: competition for adaptation between distinct cancer cell phenotypes, driven by a tumor microenvironment with scarce resources. These theoretical predictions pose an intriguing experimental challenge: test the hypothesis that invasion is an emergent property of cancer cell populations adapting to selective microenvironment pressure, rather than culmination of cancer progression producing cells with the “invasive phenotype”. In broader terms, we propose that fundamental insights into cancer can be achieved by experimentation interacting with theoretical frameworks provided by computational and mathematical modeling. PMID:18524624
Influenza A Virus Isolation, Culture and Identification
Eisfeld, Amie J.; Neumann, Gabriele; Kawaoka, Yoshihiro
2017-01-01
SUMMARY Influenza A viruses (IAV) cause epidemics and pandemics that result in considerable financial burden and loss of human life. To manage annual IAV epidemics and prepare for future pandemics, improved understanding of how IAVs emerge, transmit, cause disease, and acquire pandemic potential is urgently needed. Fundamental techniques essential for procuring such knowledge are IAV isolation and culture from experimental and surveillance samples. Here, we present a detailed protocol for IAV sample collection and processing, amplification in chicken eggs and mammalian cells, and identification from samples containing unknown pathogens. This protocol is robust, and allows for generation of virus cultures that can be used for downstream analyses. Once experimental or surveillance samples are obtained, virus cultures can be generated and the presence of IAV can be verified in 3–5 days. Increased time-frames may be required for less experienced laboratory personnel, or when large numbers of samples will be processed. PMID:25321410
Spontaneous formation and dynamics of half-skyrmions in a chiral liquid-crystal film
NASA Astrophysics Data System (ADS)
Nych, Andriy; Fukuda, Jun-Ichi; Ognysta, Uliana; Žumer, Slobodan; Muševič, Igor
2017-12-01
Skyrmions are coreless vortex-like excitations emerging in diverse condensed-matter systems, and real-time observation of their dynamics is still challenging. Here we report the first direct optical observation of the spontaneous formation of half-skyrmions. In a thin film of a chiral liquid crystal, depending on experimental conditions including film thickness, they form a hexagonal lattice whose lattice constant is a few hundred nanometres, or appear as isolated entities with topological defects compensating their charge. These half-skyrmions exhibit intriguing dynamical behaviour driven by thermal fluctuations. Numerical calculations of real-space images successfully corroborate the experimental observations despite the challenge because of the characteristic scale of the structures close to the optical resolution limit. A thin film of a chiral liquid crystal thus offers an intriguing platform that facilitates a direct investigation of the dynamics of topological excitations such as half-skyrmions and their manipulation with optical techniques.
Complexities in Ferret Influenza Virus Pathogenesis and Transmission Models
Eckert, Alissa M.; Tumpey, Terrence M.; Maines, Taronna R.
2016-01-01
SUMMARY Ferrets are widely employed to study the pathogenicity, transmissibility, and tropism of influenza viruses. However, inherent variations in inoculation methods, sampling schemes, and experimental designs are often overlooked when contextualizing or aggregating data between laboratories, leading to potential confusion or misinterpretation of results. Here, we provide a comprehensive overview of parameters to consider when planning an experiment using ferrets, collecting data from the experiment, and placing results in context with previously performed studies. This review offers information that is of particular importance for researchers in the field who rely on ferret data but do not perform the experiments themselves. Furthermore, this review highlights the breadth of experimental designs and techniques currently available to study influenza viruses in this model, underscoring the wide heterogeneity of protocols currently used for ferret studies while demonstrating the wealth of information which can benefit risk assessments of emerging influenza viruses. PMID:27412880
Complexities in Ferret Influenza Virus Pathogenesis and Transmission Models.
Belser, Jessica A; Eckert, Alissa M; Tumpey, Terrence M; Maines, Taronna R
2016-09-01
Ferrets are widely employed to study the pathogenicity, transmissibility, and tropism of influenza viruses. However, inherent variations in inoculation methods, sampling schemes, and experimental designs are often overlooked when contextualizing or aggregating data between laboratories, leading to potential confusion or misinterpretation of results. Here, we provide a comprehensive overview of parameters to consider when planning an experiment using ferrets, collecting data from the experiment, and placing results in context with previously performed studies. This review offers information that is of particular importance for researchers in the field who rely on ferret data but do not perform the experiments themselves. Furthermore, this review highlights the breadth of experimental designs and techniques currently available to study influenza viruses in this model, underscoring the wide heterogeneity of protocols currently used for ferret studies while demonstrating the wealth of information which can benefit risk assessments of emerging influenza viruses. Copyright © 2016, American Society for Microbiology. All Rights Reserved.
Dynamic fluctuation of proteins watched in real time
Ormos, Pál
2008-01-01
The dynamic nature of protein function is a fundamental concept in the physics of proteins. Although the basic general ideas are well accepted most experimental evidence has an indirect nature. The detailed characterization of the dynamics is necessary for the understanding in detail. The dynamic fluctuations thought crucial for the function span an extremely broad time, starting from the picosecond regime. Recently, a few new experimental techniques emerged that permit the observation of dynamical phenomena directly. Notably, pulsed infrared (IR) spectroscopy has been applied with great success to observe structural changes with picosecond time resolution. Using two-dimensional-IR vibrational echo chemical exchange spectroscopy Ishikawa and co-workers [Ishikawa et al. (2008), Proc. Natl. Acad. Sci. U.S.A. 101, 14402–14407] managed to observe the transition between well defined conformational substrates of carbonmonoxy myoglobin directly. This is an important step in improving our insight into the details of protein function. PMID:19436491
Diffusion of novel foraging behaviour in Amazon parrots through social learning.
Morales Picard, Alejandra; Hogan, Lauren; Lambert, Megan L; Wilkinson, Anna; Seed, Amanda M; Slocombe, Katie E
2017-03-01
While social learning has been demonstrated in species across many taxa, the role it plays in everyday foraging decisions is not well understood. Investigating social learning during foraging could shed light on the emergence of cultural variation in different groups. We used an open diffusion experiment to examine the spread of a novel foraging technique in captive Amazon parrots. Three groups were tested using a two-action foraging box, including experimental groups exposed to demonstrators using different techniques and control birds. We also examined the influence of agonistic and pilfering behaviour on task acquisition. We found evidence of social learning: more experimental birds than control birds interacted with and opened the box. The birds were, however, no more likely to use the demonstrated technique than the non-demonstrated one, making local or stimulus enhancement the most likely mechanism. Exhibiting aggression was positively correlated with box opening, whilst receiving aggression did not reduce motivation to engage with the box, indicating that willingness to defend access to the box was important in task acquisition. Pilfering food and success in opening the box were also positively correlated; however, having food pilfered did not affect victims' motivation to interact with the box. In a group context, pilfering may promote learning of new foraging opportunities. Although previous studies have demonstrated that psittacines are capable of imitation, in this naturalistic set-up there was no evidence that parrots copied the demonstrated opening technique. Foraging behaviour in wild populations of Amazons could therefore be facilitated by low-fidelity social learning mechanisms.
Gundupalli, Sathish Paulraj; Hait, Subrata; Thakur, Atul
2017-12-01
There has been a significant rise in municipal solid waste (MSW) generation in the last few decades due to rapid urbanization and industrialization. Due to the lack of source segregation practice, a need for automated segregation of recyclables from MSW exists in the developing countries. This paper reports a thermal imaging based system for classifying useful recyclables from simulated MSW sample. Experimental results have demonstrated the possibility to use thermal imaging technique for classification and a robotic system for sorting of recyclables in a single process step. The reported classification system yields an accuracy in the range of 85-96% and is comparable with the existing single-material recyclable classification techniques. We believe that the reported thermal imaging based system can emerge as a viable and inexpensive large-scale classification-cum-sorting technology in recycling plants for processing MSW in developing countries. Copyright © 2017 Elsevier Ltd. All rights reserved.
Federico, Alejandro; Kaufmann, Guillermo H
2003-12-10
We evaluate the use of a smoothed space-frequency distribution (SSFD) to retrieve optical phase maps in digital speckle pattern interferometry (DSPI). The performance of this method is tested by use of computer-simulated DSPI fringes. Phase gradients are found along a pixel path from a single DSPI image, and the phase map is finally determined by integration. This technique does not need the application of a phase unwrapping algorithm or the introduction of carrier fringes in the interferometer. It is shown that a Wigner-Ville distribution with a smoothing Gaussian kernel gives more-accurate results than methods based on the continuous wavelet transform. We also discuss the influence of filtering on smoothing of the DSPI fringes and some additional limitations that emerge when this technique is applied. The performance of the SSFD method for processing experimental data is then illustrated.
Plasmonic nanoparticles for a bottom-up approach to fabricate optical metamaterials
NASA Astrophysics Data System (ADS)
Dintinger, José; Scharf, Toralf
2012-03-01
We investigate experimentally metallic nanoparticle composites fabricated by bottom-up techniques as potential candidates for optical metamaterials. Depending on the plasmonic resonances sustained by individual NPs and their nanoscale organization into larger meta-atoms, various properties might emerge. Here, the focus of our contribution is on the fabrication and optical characterization of silver NP clusters with a spherical shape. We start with the characterisation of the "bulk" dielectric constants of silver NP inks by spectroscopic ellipsometry for different nanoparticle densities (i.e from strongly diluted dispersions to solid randomly packed films). The inks are then used to prepare spherical nanoparticle clusters by an oil-in water emulsion technique. The study of their optical properties demonstrates their ability to support Mie resonances in the visible. These resonances are associated with the excitation of a magnetic dipole, which constitutes a prerequisite to the realization of metamaterials with negative permeability.
T-L Plane Abstraction-Based Energy-Efficient Real-Time Scheduling for Multi-Core Wireless Sensors.
Kim, Youngmin; Lee, Ki-Seong; Pham, Ngoc-Son; Lee, Sun-Ro; Lee, Chan-Gun
2016-07-08
Energy efficiency is considered as a critical requirement for wireless sensor networks. As more wireless sensor nodes are equipped with multi-cores, there are emerging needs for energy-efficient real-time scheduling algorithms. The T-L plane-based scheme is known to be an optimal global scheduling technique for periodic real-time tasks on multi-cores. Unfortunately, there has been a scarcity of studies on extending T-L plane-based scheduling algorithms to exploit energy-saving techniques. In this paper, we propose a new T-L plane-based algorithm enabling energy-efficient real-time scheduling on multi-core sensor nodes with dynamic power management (DPM). Our approach addresses the overhead of processor mode transitions and reduces fragmentations of the idle time, which are inherent in T-L plane-based algorithms. Our experimental results show the effectiveness of the proposed algorithm compared to other energy-aware scheduling methods on T-L plane abstraction.
Characterising laser beams with liquid crystal displays
NASA Astrophysics Data System (ADS)
Dudley, Angela; Naidoo, Darryl; Forbes, Andrew
2016-02-01
We show how one can determine the various properties of light, from the modal content of laser beams to decoding the information stored in optical fields carrying orbital angular momentum, by performing a modal decomposition. Although the modal decomposition of light has been known for a long time, applied mostly to pattern recognition, we illustrate how this technique can be implemented with the use of liquid-crystal displays. We show experimentally how liquid crystal displays can be used to infer the intensity, phase, wavefront, Poynting vector, and orbital angular momentum density of unknown optical fields. This measurement technique makes use of a single spatial light modulator (liquid crystal display), a Fourier transforming lens and detector (CCD or photo-diode). Such a diagnostic tool is extremely relevant to the real-time analysis of solid-state and fibre laser systems as well as mode division multiplexing as an emerging technology in optical communication.
Cell-based therapies and imaging in cardiology.
Bengel, Frank M; Schachinger, Volker; Dimmeler, Stefanie
2005-12-01
Cell therapy for cardiac repair has emerged as one of the most exciting and promising developments in cardiovascular medicine. Evidence from experimental and clinical studies is increasing that this innovative treatment will influence clinical practice in the future. But open questions and controversies with regard to the basic mechanisms of this therapy continue to exist and emphasise the need for specific techniques to visualise the mechanisms and success of therapy in vivo. Several non-invasive imaging approaches which aim at tracking of transplanted cells in the heart have been introduced. Among these are direct labelling of cells with radionuclides or paramagnetic agents, and the use of reporter genes for imaging of cell transplantation and differentiation. Initial studies have suggested that these molecular imaging techniques have great potential. Integration of cell imaging into studies of cardiac cell therapy holds promise to facilitate further growth of the field towards a broadly clinically useful application.
Cerebrovascular-Reactivity Mapping Using MRI: Considerations for Alzheimer's Disease.
Chen, J J
2018-01-01
Alzheimer's disease (AD) is associated with well-established macrostructural and cellular markers, including localized brain atrophy and deposition of amyloid. However, there is growing recognition of the link between cerebrovascular dysfunction and AD, supported by continuous experimental evidence in the animal and human literature. As a result, neuroimaging studies of AD are increasingly aiming to incorporate vascular measures, exemplified by measures of cerebrovascular reactivity (CVR). CVR is a measure that is rooted in clinical practice, and as non-invasive CVR-mapping techniques become more widely available, routine CVR mapping may open up new avenues of investigation into the development of AD. This review focuses on the use of MRI to map CVR, paying specific attention to recent developments in MRI methodology and on the emerging stimulus-free approaches to CVR mapping. It also summarizes the biological basis for the vascular contribution to AD, and provides critical perspective on the choice of CVR-mapping techniques amongst frail populations.
Dimension reduction techniques for the integrative analysis of multi-omics data
Zeleznik, Oana A.; Thallinger, Gerhard G.; Kuster, Bernhard; Gholami, Amin M.
2016-01-01
State-of-the-art next-generation sequencing, transcriptomics, proteomics and other high-throughput ‘omics' technologies enable the efficient generation of large experimental data sets. These data may yield unprecedented knowledge about molecular pathways in cells and their role in disease. Dimension reduction approaches have been widely used in exploratory analysis of single omics data sets. This review will focus on dimension reduction approaches for simultaneous exploratory analyses of multiple data sets. These methods extract the linear relationships that best explain the correlated structure across data sets, the variability both within and between variables (or observations) and may highlight data issues such as batch effects or outliers. We explore dimension reduction techniques as one of the emerging approaches for data integration, and how these can be applied to increase our understanding of biological systems in normal physiological function and disease. PMID:26969681
A decade of innovation with laser speckle metrology
NASA Astrophysics Data System (ADS)
Ettemeyer, Andreas
2003-05-01
Speckle Pattern Interferometry has emerged from the experimental substitution of holographic interferometry to become a powerful problem solving tool in research and industry. The rapid development of computer and digital imaging techniques in combination with minaturization of the optical equipment led to new applications which had not been anticipated before. While classical holographic interferometry had always required careful consideration of the environmental conditions such as vibration, noise, light, etc. and could generally only be performed in the optical laboratory, it is now state of the art, to handle portable speckle measuring equipment at almost any place. During the last decade, the change in design and technique has dramatically influenced the range of applications of speckle metrology and opened new markets. The integration of recent research results into speckle measuring equipment has led to handy equipment, simplified the operation and created high quality data output.
Towards adaptive, streaming analysis of x-ray tomography data
DOE Office of Scientific and Technical Information (OSTI.GOV)
Thomas, Mathew; Kleese van Dam, Kerstin; Marshall, Matthew J.
2015-03-04
Temporal and spatial resolution of chemical imaging methodologies such as x-ray tomography are rapidly increasing, leading to more complex experimental procedures and fast growing data volumes. Automated analysis pipelines and big data analytics are becoming essential to effectively evaluate the results of such experiments. Offering those data techniques in an adaptive, streaming environment can further substantially improve the scientific discovery process, by enabling experimental control and steering based on the evaluation of emerging phenomena as they are observed by the experiment. Pacific Northwest National Laboratory (PNNL)’ Chemical Imaging Initiative (CII - http://imaging.pnnl.gov/ ) has worked since 2011 towards developing amore » framework that allows users to rapidly compose and customize high throughput experimental analysis pipelines for multiple instrument types. The framework, named ‘Rapid Experimental Analysis’ (REXAN) Framework [1], is based on the idea of reusable component libraries and utilizes the PNNL developed collaborative data management and analysis environment ‘Velo’, to provide a user friendly analysis and data management environment for experimental facilities. This article will, discuss the capabilities established for X-Ray tomography, discuss lessons learned, and provide an overview of our more recent work in the Analysis in Motion Initiative (AIM - http://aim.pnnl.gov/ ) at PNNL to provide REXAN capabilities in a streaming environment.« less
USDA-ARS?s Scientific Manuscript database
Parametric non-linear regression (PNR) techniques commonly are used to develop weed seedling emergence models. Such techniques, however, require statistical assumptions that are difficult to meet. To examine and overcome these limitations, we compared PNR with a nonparametric estimation technique. F...
Excitation-resolved cone-beam x-ray luminescence tomography.
Liu, Xin; Liao, Qimei; Wang, Hongkai; Yan, Zhuangzhi
2015-07-01
Cone-beam x-ray luminescence computed tomography (CB-XLCT), as an emerging imaging technique, plays an important role in in vivo small animal imaging studies. However, CB-XLCT suffers from low-spatial resolution due to the ill-posed nature of reconstruction. We improve the imaging performance of CB-XLCT by using a multiband excitation-resolved imaging scheme combined with principal component analysis. To evaluate the performance of the proposed method, the physical phantom experiment is performed with a custom-made XLCT/XCT imaging system. The experimental results validate the feasibility of the method, where two adjacent nanophosphors (with an edge-to-edge distance of 2.4 mm) can be located.
NASA Astrophysics Data System (ADS)
Leitão, João; Pereira, José; Rodrigues, Luís
Gossip, or epidemic, protocols have emerged as a powerful strategy to implement highly scalable and resilient reliable broadcast primitives on large scale peer-to-peer networks. Epidemic protocols are scalable because they distribute the load among all nodes in the system and resilient because they have an intrinsic level of redundancy that masks node and network failures. This chapter provides an introduction to gossip-based broadcast on large-scale unstructured peer-to-peer overlay networks: it surveys the main results in the field, discusses techniques to build and maintain the overlays that support efficient dissemination strategies, and provides an in-depth discussion and experimental evaluation of two concrete protocols, named HyParView and Plumtree.
Scanning Tunneling Microscopy analysis of space-exposed polymer films
NASA Technical Reports Server (NTRS)
Kalil, Carol R.; Young, Philip R.
1993-01-01
The characterization of the surface of selected space-exposed polymer films by Scanning Tunneling Microscopy (STM) is reported. Principles of STM, an emerging new technique for materials analysis, are reviewed. The analysis of several films which received up to 5.8 years of low Earth orbital (LEO) exposure onboard the NASA Long Duration Exposure Facility (LDEF) is discussed. Specimens included FEP Teflon thermal blanket material, Kapton film, and several experimental polymer films. Ultraviolet and atomic oxygen-induced crazing and erosion are described. The intent of this paper is to demonstrate how STM is enhancing the understanding of LEO space environmental effects on polymer films.
2013-08-27
ISS036-E-037288 (27 Aug. 2013) --- In the International Space Station?s Kibo laboratory, NASA astronaut Karen Nyberg, Expedition 36 flight engineer, conducts a session with a pair of bowling-ball-sized free-flying satellites known as Synchronized Position Hold, Engage, Reorient, Experimental Satellites, or SPHERES. Surrounding the two SPHERES mini-satellites with ring-shaped hardware known as the Resonant Inductive Near-field Generation System, or RINGS, Nyberg performed a demonstration of how power can be transferred between two satellites without physical contact. Station crews beginning with Expedition 8 have operated these robots to test techniques that could lead to advancements in automated dockings, satellite servicing, spacecraft assembly and emergency repairs.
CE-BLAST makes it possible to compute antigenic similarity for newly emerging pathogens.
Qiu, Tianyi; Yang, Yiyan; Qiu, Jingxuan; Huang, Yang; Xu, Tianlei; Xiao, Han; Wu, Dingfeng; Zhang, Qingchen; Zhou, Chen; Zhang, Xiaoyan; Tang, Kailin; Xu, Jianqing; Cao, Zhiwei
2018-05-02
Major challenges in vaccine development include rapidly selecting or designing immunogens for raising cross-protective immunity against different intra- or inter-subtypic pathogens, especially for the newly emerging varieties. Here we propose a computational method, Conformational Epitope (CE)-BLAST, for calculating the antigenic similarity among different pathogens with stable and high performance, which is independent of the prior binding-assay information, unlike the currently available models that heavily rely on the historical experimental data. Tool validation incorporates influenza-related experimental data sufficient for stability and reliability determination. Application to dengue-related data demonstrates high harmonization between the computed clusters and the experimental serological data, undetectable by classical grouping. CE-BLAST identifies the potential cross-reactive epitope between the recent zika pathogen and the dengue virus, precisely corroborated by experimental data. The high performance of the pathogens without the experimental binding data suggests the potential utility of CE-BLAST to rapidly design cross-protective vaccines or promptly determine the efficacy of the currently marketed vaccine against emerging pathogens, which are the critical factors for containing emerging disease outbreaks.
Yasmin, Ephia; Balachandren, Neerujah; Davies, Melanie C; Jones, Georgina L; Lane, Sheila; Mathur, Raj; Webber, Lisa; Anderson, Richard A
2018-04-01
Fertility preservation in the female poses several challenges due to the invasive nature of the techniques available to achieve it. The guideline aims to bring together the evidence available for the measures for fertility preservation and their outcome. The guideline addresses fertility preservation for medical reasons and includes both oncological and non-oncological causes. The techniques that the guideline considers are: (i) embryo and oocyte cryopreservation; (ii) ovarian tissue cryopreservation; (iii) GnRH agonist suppression and (iv) ovarian transposition. Although ovarian tissue cryopreservation is still considered experimental, the availability of this technique is gaining momentum as more live births from auto-transplanted tissue are reported. The guideline also highlights use of current treatment modalities for benign and malignant conditions that have a better fertility sparing profile. The guideline recommends a multidisciplinary approach in counselling women and girls about the risk to their fertility and available techniques. The role of psychological support in assisting women and girls with decision-making is highlighted. The guideline also highlights the risks associated with these techniques. Women need to be medically fit to undergo invasive procedures. Fertility preservation techniques are appropriate when treatment has curative intent. Fertility preservation is a subject of on-going research on outcomes of different techniques and at the time of publication, studies are still likely to emerge adding to the available literature.
The use of nuclear medicine techniques in the emergency department
McGlone, B; Balan, K
2001-01-01
Nuclear medicine techniques have received little attention in the practice of emergency medicine, yet radionuclide imaging can provide valuable and unique information in the management of acutely ill patients. In this review, emphasis is placed on the role of these techniques in patients with bone injuries, non-traumatic bone pain and in those with pleuritic chest pain. New developments such as single photon emission computed tomography (SPECT) in myocardial infarction are outlined and older techniques such as scrotal scintigraphy are reviewed. Radionuclide techniques are discussed in a clinical context and in relation to alternative imaging modalities or strategies that may be available to the emergency medicine physician. Aspects of a 24 hour nuclear medicine service are considered. PMID:11696487
Numerical simulation of turbulent gas flames in tubes.
Salzano, E; Marra, F S; Russo, G; Lee, J H S
2002-12-02
Computational fluid dynamics (CFD) is an emerging technique to predict possible consequences of gas explosion and it is often considered a powerful and accurate tool to obtain detailed results. However, systematic analyses of the reliability of this approach to real-scale industrial configurations are still needed. Furthermore, few experimental data are available for comparison and validation. In this work, a set of well documented experimental data related to the flame acceleration obtained within obstacle-filled tubes filled with flammable gas-air mixtures, has been simulated. In these experiments, terminal steady flame speeds corresponding to different propagation regimes were observed, thus, allowing a clear and prompt characterisation of the numerical results with respect to numerical parameters, as grid definition, geometrical parameters, as blockage ratio and to mixture parameters, as mixture reactivity. The CFD code AutoReagas was used for the simulations. Numerical predictions were compared with available experimental data and some insights into the code accuracy were determined. Computational results are satisfactory for the relatively slower turbulent deflagration regimes and became fair when choking regime is observed, whereas transition to quasi-detonation or Chapman-Jogouet (CJ) were never predicted.
Contreras-Torres, Flavio F; Basiuk, Elena V; Basiuk, Vladimir A; Meza-Laguna, Víctor; Gromovoy, Taras Yu
2012-02-16
Nanostructure derivatives of fullerene C(60) are used in emerging applications of composite matrices, including protective and decorative coating, superadsorbent material, thin films, and lightweight high-strength fiber-reinforced materials, etc. In this study, quantum chemical calculations and experimental studies were performed to analyze the derivatives of diamine-fullerene prepared by the gas-phase solvent-free functionalization technique. In particular, the aliphatic 1,8-diamino-octane and the aromatic 1,5-diaminonaphthalene, which are diamines volatile in vacuum, were studied. We addressed two alternative mechanisms of the amination reaction via polyaddition and cross-linking of C(60) with diamines, using the pure GGA BLYP, PW91, and PBE functionals; further validation calculations were performed using the semiempirical dispersion GGA B97-D functional which contains parameters that have been specially adjusted by a more realistic view on dispersion contributions. In addition, we looked for experimental evidence for the covalent functionalization by using laser desorption/ionization time-of-flight mass spectrometry, thermogravimetric analysis, and atomic force microscopy.
On the evolution of cured voxel in bulk photopolymerization upon focused Gaussian laser exposure
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bhole, Kiran, E-mail: kirandipali@gmail.com; Gandhi, Prasanna; Kundu, T.
Unconstrained depth photopolymerization is emerging as a promising technique for fabrication of several polymer microstructures such as self propagating waveguides, 3D freeform structures by bulk lithography, and polymer nanoparticles by flash exposure. Experimental observations reveal governing physics beyond Beer Lambert's law and scattering effects. This paper seeks to model unconstrained depth photopolymerization using classical nonlinear Schrödinger equation coupled with transient diffusion phenomenon. The beam propagation part of the proposed model considers scattering effects induced due to spatial variation of the refractive index as a function of the beam intensity. The critical curing energy model is used to further predict profilemore » of polymerized voxel. Profiles of photopolymerized voxel simulated using proposed model are compared with the corresponding experimental results for several cases of exposure dose and duration. The comparison shows close match leading to conclusion that the experimentally observed deviation from Beer Lambert's law is indeed due to combined effect of diffusion of photoinitiator and scattering of light because of change in the refractive index.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Yan, Fangyong; Lartey, Michael; Damodaran, Krishnan
2013-01-01
Ionic liquids are an emerging class of materials with applications in a variety of fields. Steady progress has been made in the creation of ionic liquids tailored to specific applications. However, the understanding of the underlying structure–property relationships has been slower to develop. As a step in the effort to alleviate this deficiency, the influence of side groups on ionic liquid properties has been studied through an integrated approach utilizing synthesis, experimental determination of properties, and simulation techniques. To achieve this goal, a classical force field in the framework of OPLS/Amber force fields has been developed to predict ionic liquidmore » properties accurately. Cu(I)-catalyzed click chemistry was employed to synthesize triazolium-based ionic liquids with diverse side groups. Values of densities were predicted within 3% of experimental values, whereas self-diffusion coefficients were underestimated by about an order of magnitude though the trends were in excellent agreement, the activation energy calculated in simulation correlates well with experimental values. The predicted Henry coefficient for CO{sub 2} solubility reproduced the experimentally observed trends. This study highlights the importance of integrating experimental and computational approaches in property prediction and materials development, which is not only useful in the development of ionic liquids for CO{sub 2} capture but has application in many technological fields.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Yan, Fangyong; Lartey, Michael; Damodaran, Krishnan
Ionic liquids are an emerging class of materials with applications in a variety of fields. Steady progress has been made in the creation of ionic liquids tailored to specific applications. However, the understanding of the underlying structure–property relationships has been slower to develop. As a step in the effort to alleviate this deficiency, the influence of side groups on ionic liquid properties has been studied through an integrated approach utilizing synthesis, experimental determination of properties, and simulation techniques. To achieve this goal, a classical force field in the framework of OPLS/Amber force fields has been developed to predict ionic liquidmore » properties accurately. Cu(I)-catalyzed click chemistry was employed to synthesize triazolium-based ionic liquids with diverse side groups. Values of densities were predicted within 3% of experimental values, whereas self-diffusion coefficients were underestimated by about an order of magnitude though the trends were in excellent agreement, the activation energy calculated in simulation correlates well with experimental values. The predicted Henry coefficient for CO{sub 2} solubility reproduced the experimentally observed trends. This study highlights the importance of integrating experimental and computational approaches in property prediction and materials development, which is not only useful in the development of ionic liquids for CO{sub 2} capture but has application in many technological fields.« less
Roy F. Shepherd
1983-01-01
A technique is described to relate seasonal development of buds of Douglas-fir, Pseudotsuga menziesii (Mirt.) Franco, to larval emergence and survival of western spruce budworm (Choristoneura occidentalis Freeman) (Tortricidae). Losses of larvae due to asynchrony of emergence and bud swelling and the reduced protection of the...
Ye, Xiaoduan; O'Neil, Patrick K; Foster, Adrienne N; Gajda, Michal J; Kosinski, Jan; Kurowski, Michal A; Bujnicki, Janusz M; Friedman, Alan M; Bailey-Kellogg, Chris
2004-12-01
Emerging high-throughput techniques for the characterization of protein and protein-complex structures yield noisy data with sparse information content, placing a significant burden on computation to properly interpret the experimental data. One such technique uses cross-linking (chemical or by cysteine oxidation) to confirm or select among proposed structural models (e.g., from fold recognition, ab initio prediction, or docking) by testing the consistency between cross-linking data and model geometry. This paper develops a probabilistic framework for analyzing the information content in cross-linking experiments, accounting for anticipated experimental error. This framework supports a mechanism for planning experiments to optimize the information gained. We evaluate potential experiment plans using explicit trade-offs among key properties of practical importance: discriminability, coverage, balance, ambiguity, and cost. We devise a greedy algorithm that considers those properties and, from a large number of combinatorial possibilities, rapidly selects sets of experiments expected to discriminate pairs of models efficiently. In an application to residue-specific chemical cross-linking, we demonstrate the ability of our approach to plan experiments effectively involving combinations of cross-linkers and introduced mutations. We also describe an experiment plan for the bacteriophage lambda Tfa chaperone protein in which we plan dicysteine mutants for discriminating threading models by disulfide formation. Preliminary results from a subset of the planned experiments are consistent and demonstrate the practicality of planning. Our methods provide the experimenter with a valuable tool (available from the authors) for understanding and optimizing cross-linking experiments.
Real-time emergency forecasting technique for situation management systems
NASA Astrophysics Data System (ADS)
Kopytov, V. V.; Kharechkin, P. V.; Naumenko, V. V.; Tretyak, R. S.; Tebueva, F. B.
2018-05-01
The article describes the real-time emergency forecasting technique that allows increasing accuracy and reliability of forecasting results of any emergency computational model applied for decision making in situation management systems. Computational models are improved by the Improved Brown’s method applying fractal dimension to forecast short time series data being received from sensors and control systems. Reliability of emergency forecasting results is ensured by the invalid sensed data filtering according to the methods of correlation analysis.
Russell, Shane R; Claridge, Shelley A
2016-04-01
Because noncovalent interface functionalization is frequently required in graphene-based devices, biomolecular self-assembly has begun to emerge as a route for controlling substrate electronic structure or binding specificity for soluble analytes. The remarkable diversity of structures that arise in biological self-assembly hints at the possibility of equally diverse and well-controlled surface chemistry at graphene interfaces. However, predicting and analyzing adsorbed monolayer structures at such interfaces raises substantial experimental and theoretical challenges. In contrast with the relatively well-developed monolayer chemistry and characterization methods applied at coinage metal surfaces, monolayers on graphene are both less robust and more structurally complex, levying more stringent requirements on characterization techniques. Theory presents opportunities to understand early binding events that lay the groundwork for full monolayer structure. However, predicting interactions between complex biomolecules, solvent, and substrate is necessitating a suite of new force fields and algorithms to assess likely binding configurations, solvent effects, and modulations to substrate electronic properties. This article briefly discusses emerging analytical and theoretical methods used to develop a rigorous chemical understanding of the self-assembly of peptide-graphene interfaces and prospects for future advances in the field.
Xu, Jian; Vik, Alexandra; Groote, Inge R; Lagopoulos, Jim; Holen, Are; Ellingsen, Oyvind; Håberg, Asta K; Davanger, Svend
2014-01-01
Nondirective meditation techniques are practiced with a relaxed focus of attention that permits spontaneously occurring thoughts, images, sensations, memories, and emotions to emerge and pass freely, without any expectation that mind wandering should abate. These techniques are thought to facilitate mental processing of emotional experiences, thereby contributing to wellness and stress management. The present study assessed brain activity by functional magnetic resonance imaging (fMRI) in 14 experienced practitioners of Acem meditation in two experimental conditions. In the first, nondirective meditation was compared to rest. Significantly increased activity was detected in areas associated with attention, mind wandering, retrieval of episodic memories, and emotional processing. In the second condition, participants carried out concentrative practicing of the same meditation technique, actively trying to avoid mind wandering. The contrast nondirective meditation > concentrative practicing was characterized by higher activity in the right medial temporal lobe (parahippocampal gyrus and amygdala). In conclusion, the present results support the notion that nondirective meditation, which permits mind wandering, involves more extensive activation of brain areas associated with episodic memories and emotional processing, than during concentrative practicing or regular rest.
NASA Astrophysics Data System (ADS)
Anitha, J.; Vijila, C. Kezi Selva; Hemanth, D. Jude
2010-02-01
Diabetic retinopathy (DR) is a chronic eye disease for which early detection is highly essential to avoid any fatal results. Image processing of retinal images emerge as a feasible tool for this early diagnosis. Digital image processing techniques involve image classification which is a significant technique to detect the abnormality in the eye. Various automated classification systems have been developed in the recent years but most of them lack high classification accuracy. Artificial neural networks are the widely preferred artificial intelligence technique since it yields superior results in terms of classification accuracy. In this work, Radial Basis function (RBF) neural network based bi-level classification system is proposed to differentiate abnormal DR Images and normal retinal images. The results are analyzed in terms of classification accuracy, sensitivity and specificity. A comparative analysis is performed with the results of the probabilistic classifier namely Bayesian classifier to show the superior nature of neural classifier. Experimental results show promising results for the neural classifier in terms of the performance measures.
Rajasekhar, Achanta; Gimi, Barjor; Hu, Walter
2013-01-01
We live in a world of convergence where scientific techniques from a variety of seemingly disparate fields are being applied cohesively to the study and solution of biomedical problems. For instance, the semiconductor processing field has been primarily developed to cater to the needs of the ever decreasing transistor size and cost while increasing functionality of electronic circuits. In recent years, pioneers in this field have equipped themselves with a powerful understanding of how the same techniques can be applied in the biomedical field to develop new and efficient systems for the diagnosis, analysis and treatment of various conditions in the human body. In this paper, we review the major inventions and experimental methods which have been developed for nano/micro fluidic channels, nanoparticles fabricated by top-down methods, and in-vivo nanoporous microcages for effective drug delivery. This paper focuses on the information contained in patents as well as the corresponding technical publications. The goal of the paper is to help emerging scientists understand and improvise over these inventions. PMID:24312161
Photoacoustic tomography: applications for atherosclerosis imaging
NASA Astrophysics Data System (ADS)
Sangha, Gurneet S.; Goergen, Craig J.
2016-08-01
Atherosclerosis is a debilitating condition that increases a patient’s risk for intermittent claudication, limb amputation, myocardial infarction, and stroke, thereby causing approximately 50% of deaths in the western world. Current diagnostic imaging techniques, such as ultrasound, digital subtraction angiography, computed tomography angiography, magnetic resonance angiography, and optical imaging remain suboptimal for detecting development of early stage plaques. This is largely due to the lack of compositional information, penetration depth, and/or clinical efficiency of these traditional imaging techniques. Photoacoustic imaging has emerged as a promising modality that could address some of these limitations to improve the diagnosis and characterization of atherosclerosis-related diseases. Photoacoustic imaging uses near-infrared light to induce acoustic waves, which can be used to recreate compositional images of tissue. Recent developments in photoacoustic techniques show its potential in noninvasively characterizing atherosclerotic plaques deeper than traditional optical imaging approaches. In this review, we discuss the significance and development of atherosclerosis, current and novel clinical diagnostic methods, and recent works that highlight the potential of photoacoustic imaging for both experimental and clinical studies of atherosclerosis.
“Almost invisible scars”: medical tourism to Brazil.
Edmonds, Alexander
2011-01-01
Along with a handful of other nations in the developing world, Brazil has emerged as a top destination for medical tourism. Drawing on the author's ethnographic fieldwork in plastic surgery wards, this article examines diverse factors - some explicitly promoted in medical marketing and news sources, others less visible - contributing to Brazil's international reputation for excellence in cosmetic plastic surgery. Brazil's plastic surgery residency programs, some of which are housed within its public health system, attract overseas surgeons, provide ample opportunities for valuable training in cosmetic techniques, and create a clinical environment that favors experimentation with innovative techniques. Many graduates of these programs open private clinics that, in turn, attract overseas patients. High demand for Brazilian plastic surgery also reflects an expansive notion of female health that includes sexual realization, mental health, and cosmetic techniques that manage reproduction. Medical tourism is sometimes represented as being market-driven: patients in wealthier nations travel to obtain quality services at lower prices. This article ends by reflecting on how more complex local and transnational dynamics also contribute to demand for elective medical procedures such as cosmetic surgery.
Xu, Jian; Vik, Alexandra; Groote, Inge R.; Lagopoulos, Jim; Holen, Are; Ellingsen, Øyvind; Håberg, Asta K.; Davanger, Svend
2014-01-01
Nondirective meditation techniques are practiced with a relaxed focus of attention that permits spontaneously occurring thoughts, images, sensations, memories, and emotions to emerge and pass freely, without any expectation that mind wandering should abate. These techniques are thought to facilitate mental processing of emotional experiences, thereby contributing to wellness and stress management. The present study assessed brain activity by functional magnetic resonance imaging (fMRI) in 14 experienced practitioners of Acem meditation in two experimental conditions. In the first, nondirective meditation was compared to rest. Significantly increased activity was detected in areas associated with attention, mind wandering, retrieval of episodic memories, and emotional processing. In the second condition, participants carried out concentrative practicing of the same meditation technique, actively trying to avoid mind wandering. The contrast nondirective meditation > concentrative practicing was characterized by higher activity in the right medial temporal lobe (parahippocampal gyrus and amygdala). In conclusion, the present results support the notion that nondirective meditation, which permits mind wandering, involves more extensive activation of brain areas associated with episodic memories and emotional processing, than during concentrative practicing or regular rest. PMID:24616684
Comandini, A; Malewicki, T; Brezinsky, K
2012-03-01
The implementation of techniques aimed at improving engine performance and reducing particulate matter (PM) pollutant emissions is strongly influenced by the limited understanding of the polycyclic aromatic hydrocarbons (PAH) formation chemistry, in combustion devices, that produces the PM emissions. New experimental results which examine the formation of multi-ring compounds are required. The present investigation focuses on two techniques for such an experimental examination by recovery of PAH compounds from a typical combustion oriented experimental apparatus. The online technique discussed constitutes an optimal solution but not always feasible approach. Nevertheless, a detailed description of a new online sampling system is provided which can serve as reference for future applications to different experimental set-ups. In comparison, an offline technique, which is sometimes more experimentally feasible but not necessarily optimal, has been studied in detail for the recovery of a variety of compounds with different properties, including naphthalene, biphenyl, and iodobenzene. The recovery results from both techniques were excellent with an error in the total carbon balance of around 10% for the online technique and an uncertainty in the measurement of the single species of around 7% for the offline technique. Although both techniques proved to be suitable for measurement of large PAH compounds, the online technique represents the optimal solution in view of the simplicity of the corresponding experimental procedure. On the other hand, the offline technique represents a valuable solution in those cases where the online technique cannot be implemented.
Overcoming barriers to the use of osteopathic manipulation techniques in the emergency department.
Roberge, Raymond J; Roberge, Marc R
2009-08-01
Osteopathic Manipulation Techniques (OMT) have been shown to be effective therapeutic modalities in various clinical settings, but appear to be underutilized in the emergency department (ED) setting. To examine barriers to the use of OMT in the ED and provide suggestions to ameliorate these barriers. Literature review While the medical literature cites numerous obstacles to the use of OMT in the ED setting, most can be positively addressed through education, careful planning, and ongoing research into use of these techniques. Recent prospective clinical trials of OMT have demonstrated the utility of these modalities. Osteopathic Manipulation Techniques are useful therapeutic modalities that could be utilized to a greater degree in the ED. As the number of osteopathic emergency physicians increases, the opportunity to employ these techniques should increase.
Agent-based modeling in ecological economics.
Heckbert, Scott; Baynes, Tim; Reeson, Andrew
2010-01-01
Interconnected social and environmental systems are the domain of ecological economics, and models can be used to explore feedbacks and adaptations inherent in these systems. Agent-based modeling (ABM) represents autonomous entities, each with dynamic behavior and heterogeneous characteristics. Agents interact with each other and their environment, resulting in emergent outcomes at the macroscale that can be used to quantitatively analyze complex systems. ABM is contributing to research questions in ecological economics in the areas of natural resource management and land-use change, urban systems modeling, market dynamics, changes in consumer attitudes, innovation, and diffusion of technology and management practices, commons dilemmas and self-governance, and psychological aspects to human decision making and behavior change. Frontiers for ABM research in ecological economics involve advancing the empirical calibration and validation of models through mixed methods, including surveys, interviews, participatory modeling, and, notably, experimental economics to test specific decision-making hypotheses. Linking ABM with other modeling techniques at the level of emergent properties will further advance efforts to understand dynamics of social-environmental systems.
Evidence-based pain management: is the concept of integrative medicine applicable?
2012-01-01
This article is dedicated to the concept of predictive, preventive, and personalized (integrative) medicine beneficial and applicable to advance pain management, overviews recent insights, and discusses novel minimally invasive tools, performed under ultrasound guidance, enhanced by model-guided approach in the field of musculoskeletal pain and neuromuscular diseases. The complexity of pain emergence and regression demands intellectual-, image-guided techniques personally specified to the patient. For personalized approach, the combination of the modalities of ultrasound, EMG, MRI, PET, and SPECT gives new opportunities to experimental and clinical studies. Neuromuscular imaging should be crucial for emergence of studies concerning advanced neuroimaging technologies to predict movement disorders, postural imbalance with integrated application of imaging, and functional modalities for rehabilitation and pain management. Scientific results should initiate evidence-based preventive movement programs in sport medicine rehabilitation. Traditional medicine and mathematical analytical approaches and education challenges are discussed in this review. The physiological management of exactly assessed pathological condition, particularly in movement disorders, requires participative medical approach to gain harmonized and sustainable effect. PMID:23088743
Structural damage diagnostics via wave propagation-based filtering techniques
NASA Astrophysics Data System (ADS)
Ayers, James T., III
Structural health monitoring (SHM) of aerospace components is a rapidly emerging field due in part to commercial and military transport vehicles remaining in operation beyond their designed life cycles. Damage detection strategies are sought that provide real-time information of the structure's integrity. One approach that has shown promise to accurately identify and quantify structural defects is based on guided ultrasonic wave (GUW) inspections, where low amplitude attenuation properties allow for long range and large specimen evaluation. One drawback to GUWs is that they exhibit a complex multi-modal response, such that each frequency corresponds to at least two excited modes, and thus intelligent signal processing is required for even the simplest of structures. In addition, GUWs are dispersive, whereby the wave velocity is a function of frequency, and the shape of the wave packet changes over the spatial domain, requiring sophisticated detection algorithms. Moreover, existing damage quantification measures are typically formulated as a comparison of the damaged to undamaged response, which has proven to be highly sensitive to changes in environment, and therefore often unreliable. As a response to these challenges inherent to GUW inspections, this research develops techniques to locate and estimate the severity of the damage. Specifically, a phase gradient based localization algorithm is introduced to identify the defect position independent of excitation frequency and damage size. Mode separation through the filtering technique is central in isolating and extracting single mode components, such as reflected, converted, and transmitted modes that may arise from the incident wave impacting a damage. Spatially-integrated single and multiple component mode coefficients are also formulated with the intent to better characterize wave reflections and conversions and to increase the signal to noise ratios. The techniques are applied to damaged isotropic finite element plate models and experimental data obtained from Scanning Laser Doppler Vibrometry tests. Numerical and experimental parametric studies are conducted, and the current strengths and weaknesses of the proposed approaches are discussed. In particular, limitations to the damage profiling characterization are shown for low ultrasonic frequency regimes, whereas the multiple component mode conversion coefficients provide excellent noise mitigation. Multiple component estimation relies on an experimental technique developed for the estimation of Lamb wave polarization using a 1D Laser Vibrometer. Lastly, suggestions are made to apply the techniques to more structurally complex geometries.
Hu, J; Obayemi, J D; Malatesta, K; Košmrlj, A; Soboyejo, W O
2018-07-01
Targeted therapy is an emerging technique in cancer detection and treatment. This paper presents the results of a combined experimental and theoretical study of the specific targeting and entry of luteinizing hormone releasing hormone (LHRH)-conjugated PEG-coated magnetite nanoparticles into triple negative breast cancer (TNBC) cells and normal breast cells. The conjugated nanoparticles structures, cellular uptake of PEG-coated magnetite nanoparticles (MNPs) and LHRH-conjugated PEG-coated magnetite nanoparticles (LHRH-MNPs) into breast cancer cells and normal breast cells were investigated using a combination of transmission electron microscope, optical and confocal fluorescence microscopy techniques. The results show that the presence of LHRH enhances the uptake of LHRH-MNPs into TNBC cells. Nanoparticle entry into breast cancer cells is also studied using a combination of thermodynamics and kinetics models. The trends in the predicted nanoparticle entry times (into TNBC cells) and the size ranges of the engulfed nanoparticles (within the TNBC cells) are shown to be consistent with experimental observations. The implications of the results are then discussed for the specific targeting of TNBCs with LHRH-conjugated PEG-coated magnetite nanoparticles for the early detection and treatment of TNBC. Copyright © 2018. Published by Elsevier B.V.
Surface transport and stable trapping of particles and cells by an optical waveguide loop.
Hellesø, Olav Gaute; Løvhaugen, Pål; Subramanian, Ananth Z; Wilkinson, James S; Ahluwalia, Balpreet Singh
2012-09-21
Waveguide trapping has emerged as a useful technique for parallel and planar transport of particles and biological cells and can be integrated with lab-on-a-chip applications. However, particles trapped on waveguides are continuously propelled forward along the surface of the waveguide. This limits the practical usability of the waveguide trapping technique with other functions (e.g. analysis, imaging) that require particles to be stationary during diagnosis. In this paper, an optical waveguide loop with an intentional gap at the centre is proposed to hold propelled particles and cells. The waveguide acts as a conveyor belt to transport and deliver the particles/cells towards the gap. At the gap, the diverging light fields hold the particles at a fixed position. The proposed waveguide design is numerically studied and experimentally implemented. The optical forces on the particle at the gap are calculated using the finite element method. Experimentally, the method is used to transport and trap micro-particles and red blood cells at the gap with varying separations. The waveguides are only 180 nm thick and thus could be integrated with other functions on the chip, e.g. microfluidics or optical detection, to make an on-chip system for single cell analysis and to study the interaction between cells.
Tattiyapong, P; Sirikanchana, K; Surachetpong, W
2018-02-01
Tilapia lake virus (TiLV) is an emerging pathogen associated with high mortalities of wild and farm-raised tilapia in different countries. In this study, a SYBR green-based reverse transcription quantitative polymerase chain reaction (RT-qPCR) assay targeting segment three of the virus was developed to detect and quantify TiLV in clinical samples and experimentally challenged fish. All 30 field samples with clinical signs and history consistent with TiLV infection were positive for TiLV as detected by the developed RT-qPCR method. The RT-qPCR technique provided 100 and 10,000 times more sensitive for virus detection than those offered by the RT-PCR and virus isolation in cell culture methods, respectively. The detection limit of the RT-qPCR method was as low as two viral copies/μl. Moreover, the RT-qPCR technique could be applied for TiLV detection in various fish tissues including gills, liver, brain, heart, anterior kidney and spleen. Significantly, this study delivered an accurate and reliable method for rapid detection of TiLV viruses that facilitates active surveillance programme and disease containment. © 2017 John Wiley & Sons Ltd.
Accelerated 2D magnetic resonance spectroscopy of single spins using matrix completion
NASA Astrophysics Data System (ADS)
Scheuer, Jochen; Stark, Alexander; Kost, Matthias; Plenio, Martin B.; Naydenov, Boris; Jelezko, Fedor
2015-12-01
Two dimensional nuclear magnetic resonance (NMR) spectroscopy is one of the major tools for analysing the chemical structure of organic molecules and proteins. Despite its power, this technique requires long measurement times, which, particularly in the recently emerging diamond based single molecule NMR, limits its application to stable samples. Here we demonstrate a method which allows to obtain the spectrum by collecting only a small fraction of the experimental data. Our method is based on matrix completion which can recover the full spectral information from randomly sampled data points. We confirm experimentally the applicability of this technique by performing two dimensional electron spin echo envelope modulation (ESEEM) experiments on a two spin system consisting of a single nitrogen vacancy (NV) centre in diamond coupled to a single 13C nuclear spin. The signal to noise ratio of the recovered 2D spectrum is compared to the Fourier transform of randomly subsampled data, where we observe a strong suppression of the noise when the matrix completion algorithm is applied. We show that the peaks in the spectrum can be obtained with only 10% of the total number of the data points. We believe that our results reported here can find an application in all types of two dimensional spectroscopy, as long as the measured matrices have a low rank.
Dynamic Tensile Experimental Techniques for Geomaterials: A Comprehensive Review
NASA Astrophysics Data System (ADS)
Heard, W.; Song, B.; Williams, B.; Martin, B.; Sparks, P.; Nie, X.
2018-01-01
This review article is dedicated to the Dynamic Behavior of Materials Technical Division for celebrating the 75th anniversary of the Society for Experimental Mechanics (SEM). Understanding dynamic behavior of geomaterials is critical for analyzing and solving engineering problems of various applications related to underground explosions, seismic, airblast, and penetration events. Determining the dynamic tensile response of geomaterials has been a great challenge in experiments due to the nature of relatively low tensile strength and high brittleness. Various experimental approaches have been made in the past century, especially in the most recent half century, to understand the dynamic behavior of geomaterials in tension. In this review paper, we summarized the dynamic tensile experimental techniques for geomaterials that have been developed. The major dynamic tensile experimental techniques include dynamic direct tension, dynamic split tension, and spall tension. All three of the experimental techniques are based on Hopkinson or split Hopkinson (also known as Kolsky) bar techniques and principles. Uniqueness and limitations for each experimental technique are also discussed.
Dynamic Tensile Experimental Techniques for Geomaterials: A Comprehensive Review
Heard, W.; Song, B.; Williams, B.; ...
2018-01-03
Here, this review article is dedicated to the Dynamic Behavior of Materials Technical Division for celebrating the 75th anniversary of the Society for Experimental Mechanics (SEM). Understanding dynamic behavior of geomaterials is critical for analyzing and solving engineering problems of various applications related to underground explosions, seismic, airblast, and penetration events. Determining the dynamic tensile response of geomaterials has been a great challenge in experiments due to the nature of relatively low tensile strength and high brittleness. Various experimental approaches have been made in the past century, especially in the most recent half century, to understand the dynamic behavior ofmore » geomaterials in tension. In this review paper, we summarized the dynamic tensile experimental techniques for geomaterials that have been developed. The major dynamic tensile experimental techniques include dynamic direct tension, dynamic split tension, and spall tension. All three of the experimental techniques are based on Hopkinson or split Hopkinson (also known as Kolsky) bar techniques and principles. Finally, uniqueness and limitations for each experimental technique are also discussed.« less
Dynamic Tensile Experimental Techniques for Geomaterials: A Comprehensive Review
DOE Office of Scientific and Technical Information (OSTI.GOV)
Heard, W.; Song, B.; Williams, B.
Here, this review article is dedicated to the Dynamic Behavior of Materials Technical Division for celebrating the 75th anniversary of the Society for Experimental Mechanics (SEM). Understanding dynamic behavior of geomaterials is critical for analyzing and solving engineering problems of various applications related to underground explosions, seismic, airblast, and penetration events. Determining the dynamic tensile response of geomaterials has been a great challenge in experiments due to the nature of relatively low tensile strength and high brittleness. Various experimental approaches have been made in the past century, especially in the most recent half century, to understand the dynamic behavior ofmore » geomaterials in tension. In this review paper, we summarized the dynamic tensile experimental techniques for geomaterials that have been developed. The major dynamic tensile experimental techniques include dynamic direct tension, dynamic split tension, and spall tension. All three of the experimental techniques are based on Hopkinson or split Hopkinson (also known as Kolsky) bar techniques and principles. Finally, uniqueness and limitations for each experimental technique are also discussed.« less
Review of Surgical Techniques of Experimental Renal Transplantation in Rats.
Shrestha, Badri; Haylor, John
2017-08-01
Microvascular surgical techniques of renal transplant in rats have evolved over the past 5 decades to achieve successful rat renal transplant; these modifications have included surgical techniques to address the anatomic variations in the renal blood vessels and those to reduce ischemic and operation durations. Here, we review the surgical techniques of renal transplant in rats and evaluate the advantages and disadvantages of individual techniques of vascular and ureteric anastomoses. For this review, we performed a systematic literature search using relevant medical subject heading terms and included appropriate publications in the review. Since the first description of a rat model of renal transplant by Bernard Fisher and his colleagues in 1965, which used end-to-side anastomosis between the renal vein and renal artery to the recipient inferior vena cava and aorta, several vascular and ureteric anastomosis techniques have been modified. Vascular anastomosis techniques now include end-to-end anastomosis, use of donor aortic and inferior vena cava conduits, sleeve and cuff anastomoses, and application of fibrin glue. Likewise, restoration of the urinary tract can now be achieved by direct anastomosis of the donor ureter to the recipient bladder, end-to-end anastomosis between the donor and recipient ureters, and donor bladder cuff to the recipient bladder. There are advantages and disadvantages attributable to individual techniques. The range of vascular and ureteric anastomosis techniques that has emerged reflects the need for mastering more than one technique to suit the vascular anatomy of individual animals and to reduce operating time for achieving successful outcomes after renal transplant.
Heidari, Mohammad; Shahbazi, Sara
2016-01-01
Background: The aim of this study was to determine the effect of problem-solving training on decision-making skill and critical thinking in emergency medical personnel. Materials and Methods: This study is an experimental study that performed in 95 emergency medical personnel in two groups of control (48) and experimental (47). Then, a short problem-solving course based on 8 sessions of 2 h during the term, was performed for the experimental group. Of data gathering was used demographic and researcher made decision-making and California critical thinking skills questionnaires. Data were analyzed using SPSS software. Results: The finding revealed that decision-making and critical thinking score in emergency medical personnel are low and problem-solving course, positively affected the personnel’ decision-making skill and critical thinking after the educational program (P < 0.05). Conclusions: Therefore, this kind of education on problem-solving in various emergency medicine domains such as education, research, and management, is recommended. PMID:28149823
Nanotechnology research: applications in nutritional sciences.
Srinivas, Pothur R; Philbert, Martin; Vu, Tania Q; Huang, Qingrong; Kokini, Josef L; Saltos, Etta; Saos, Etta; Chen, Hongda; Peterson, Charles M; Friedl, Karl E; McDade-Ngutter, Crystal; Hubbard, Van; Starke-Reed, Pamela; Miller, Nancy; Betz, Joseph M; Dwyer, Johanna; Milner, John; Ross, Sharon A
2010-01-01
The tantalizing potential of nanotechnology is to fabricate and combine nanoscale approaches and building blocks to make useful tools and, ultimately, interventions for medical science, including nutritional science, at the scale of approximately 1-100 nm. In the past few years, tools and techniques that facilitate studies and interventions in the nanoscale range have become widely available and have drawn widespread attention. Recently, investigators in the food and nutrition sciences have been applying the tools of nanotechnology in their research. The Experimental Biology 2009 symposium entitled "Nanotechnology Research: Applications in Nutritional Sciences" was organized to highlight emerging applications of nanotechnology to the food and nutrition sciences, as well as to suggest ways for further integration of these emerging technologies into nutrition research. Speakers focused on topics that included the problems and possibilities of introducing nanoparticles in clinical or nutrition settings, nanotechnology applications for increasing bioavailability of bioactive food components in new food products, nanotechnology opportunities in food science, as well as emerging safety and regulatory issues in this area, and the basic research applications such as the use of quantum dots to visualize cellular processes and protein-protein interactions. The session highlighted several emerging areas of potential utility in nutrition research. Nutrition scientists are encouraged to leverage ongoing efforts in nanomedicine through collaborations. These efforts could facilitate exploration of previously inaccessible cellular compartments and intracellular pathways and thus uncover strategies for new prevention and therapeutic modalities.
Nanotechnology Research: Applications in Nutritional Sciences12
Srinivas, Pothur R.; Philbert, Martin; Vu, Tania Q.; Huang, Qingrong; Kokini, Josef L.; Saos, Etta; Chen, Hongda; Peterson, Charles M.; Friedl, Karl E.; McDade-Ngutter, Crystal; Hubbard, Van; Starke-Reed, Pamela; Miller, Nancy; Betz, Joseph M.; Dwyer, Johanna; Milner, John; Ross, Sharon A.
2010-01-01
The tantalizing potential of nanotechnology is to fabricate and combine nanoscale approaches and building blocks to make useful tools and, ultimately, interventions for medical science, including nutritional science, at the scale of ∼1–100 nm. In the past few years, tools and techniques that facilitate studies and interventions in the nanoscale range have become widely available and have drawn widespread attention. Recently, investigators in the food and nutrition sciences have been applying the tools of nanotechnology in their research. The Experimental Biology 2009 symposium entitled “Nanotechnology Research: Applications in Nutritional Sciences” was organized to highlight emerging applications of nanotechnology to the food and nutrition sciences, as well as to suggest ways for further integration of these emerging technologies into nutrition research. Speakers focused on topics that included the problems and possibilities of introducing nanoparticles in clinical or nutrition settings, nanotechnology applications for increasing bioavailability of bioactive food components in new food products, nanotechnology opportunities in food science, as well as emerging safety and regulatory issues in this area, and the basic research applications such as the use of quantum dots to visualize cellular processes and protein-protein interactions. The session highlighted several emerging areas of potential utility in nutrition research. Nutrition scientists are encouraged to leverage ongoing efforts in nanomedicine through collaborations. These efforts could facilitate exploration of previously inaccessible cellular compartments and intracellular pathways and thus uncover strategies for new prevention and therapeutic modalities. PMID:19939997
ERIC Educational Resources Information Center
Sager, Naomi
This investigation matches the emerging techniques in computerized natural language processing against emerging needs for such techniques in the information field to evaluate and extend such techniques for future applications and to establish a basis and direction for further research toward these goals. An overview describes developments in the…
Ding, Yuzhe; Huang, Eric; Lam, Kit S.; Pan, Tingrui
2015-01-01
Biopatterning has been increasingly used for well-defined cellular microenvironment, patterned surface topology, and guided biological cues; however, it meets additional challenges on biocompatibility, temperature and chemical sensitivity and limited reagent volume. In this paper, we target at combining the desired features from the non-contact inkjet printing and the dot-matrix impact printing to establish a versatile multiplexed micropatterning platform, referred to as Microfluidic Impact Printer (MI-Printer), for emerging biomedical applications. Using this platform, we can achieve the distinct features of no cross-contamination, minute volume manipulation with minimal dead volume, high-throughput and biocompatible printing process, multiplexed patterning with automatic alignment, printing availability for complex medium (cell suspension or colloidal solutions), interchangeable/disposable microfluidic cartridge design with out-of-cleanroom microfabrication, simple printing system assembly and configuration, all highly desirable towards biological applications. Specifically, the printing resolution of the MI-printer platform has been experimentally characterized and theoretically analyzed. Printed droplets with 80µm in diameter have been repeatedly obtained. Furthermore, two unique features of MI-printer platform, multiplexed printing and self-alignment printing, have been successfully experimentally demonstrated (less than 10µm misalignment). In addition, combinatorial patterning and biological patterning, which utilizes the multiplexed and self-alignment printing nature of the MI-printer, have been devised to demonstrate the applicability of this robust printing technique for emerging biomedical applications. PMID:23525299
Overcoming Barriers to the Use of Osteopathic Manipulation Techniques in the Emergency Department
Roberge, Raymond J.; Roberge, Marc R.
2009-01-01
Background: Osteopathic Manipulation Techniques (OMT) have been shown to be effective therapeutic modalities in various clinical settings, but appear to be underutilized in the emergency department (ED) setting. Objective: To examine barriers to the use of OMT in the ED and provide suggestions to ameliorate these barriers. Methods: Literature review Results: While the medical literature cites numerous obstacles to the use of OMT in the ED setting, most can be positively addressed through education, careful planning, and ongoing research into use of these techniques. Recent prospective clinical trials of OMT have demonstrated the utility of these modalities. Conclusion: Osteopathic Manipulation Techniques are useful therapeutic modalities that could be utilized to a greater degree in the ED. As the number of osteopathic emergency physicians increases, the opportunity to employ these techniques should increase. PMID:19718381
DOE Office of Scientific and Technical Information (OSTI.GOV)
Savic, Vesna; Hector, Louis G.; Ezzat, Hesham
This paper presents an overview of a four-year project focused on development of an integrated computational materials engineering (ICME) toolset for third generation advanced high-strength steels (3GAHSS). Following a brief look at ICME as an emerging discipline within the Materials Genome Initiative, technical tasks in the ICME project will be discussed. Specific aims of the individual tasks are multi-scale, microstructure-based material model development using state-of-the-art computational and experimental techniques, forming, toolset assembly, design optimization, integration and technical cost modeling. The integrated approach is initially illustrated using a 980 grade transformation induced plasticity (TRIP) steel, subject to a two-step quenching andmore » partitioning (Q&P) heat treatment, as an example.« less
Fluorescence Lifetime Imaging Microscopy (FLIM) of quantum dots in living cells
NASA Astrophysics Data System (ADS)
Nadeau, Jay; Carlini, Lina
2013-02-01
Fluorescence lifetime imaging microscopy (FLIM) is an emerging imaging technique that can indicate environmental factors such as pH and redox potential by the effect of these factors on the fluorescence lifetimes of fluorophores. Semiconductor quantum dots (QDs) are highly sensitive to environment and so are ideal for use in FLIM, although certain experimental parameters must be carefully considered for QD imaging to account for their long lifetimes and two-photon behavior. We image the uptake of three types of QDs in cultured fibroblasts and show some preliminary results on the effects of endosomes and lysosomes on QD lifetimes. These results indicate the feasibility of FLIM for studies using QDs in live cells.
Lessons from non-canonical splicing
Ule, Jernej
2016-01-01
Recent improvements in experimental and computational techniques used to study the transcriptome have enabled an unprecedented view of RNA processing, revealing many previously unknown non-canonical splicing events. This includes cryptic events located far from the currently annotated exons, and unconventional splicing mechanisms that have important roles in regulating gene expression. These non-canonical splicing events are a major source of newly emerging transcripts during evolution, especially when they involve sequences derived from transposable elements. They are therefore under precise regulation and quality control, which minimises their potential to disrupt gene expression. While non-canonical splicing can lead to aberrant transcripts that cause many diseases, we also explain how it can be exploited for new therapeutic strategies. PMID:27240813
Proteomics for understanding miRNA biology
Huang, Tai-Chung; Pinto, Sneha M.; Pandey, Akhilesh
2013-01-01
MicroRNAs (miRNAs) are small noncoding RNAs that play important roles in posttranscriptional regulation of gene expression. Mature miRNAs associate with the RNA interference silencing complex to repress mRNA translation and/or degrade mRNA transcripts. Mass spectrometry-based proteomics has enabled identification of several core components of the canonical miRNA processing pathway and their posttranslational modifications which are pivotal in miRNA regulatory mechanisms. The use of quantitative proteomic strategies has also emerged as a key technique for experimental identification of miRNA targets by allowing direct determination of proteins whose levels are altered because of translational suppression. This review focuses on the role of proteomics and labeling strategies to understand miRNA biology. PMID:23125164
Identifying and quantifying interactions in a laboratory swarm
NASA Astrophysics Data System (ADS)
Puckett, James; Kelley, Douglas; Ouellette, Nicholas
2013-03-01
Emergent collective behavior, such as in flocks of birds or swarms of bees, is exhibited throughout the animal kingdom. Many models have been developed to describe swarming and flocking behavior using systems of self-propelled particles obeying simple rules or interacting via various potentials. However, due to experimental difficulties and constraints, little empirical data exists for characterizing the exact form of the biological interactions. We study laboratory swarms of flying Chironomus riparius midges, using stereoimaging and particle tracking techniques to record three-dimensional trajectories for all the individuals in the swarm. We describe methods to identify and quantify interactions by examining these trajectories, and report results on interaction magnitude, frequency, and mutuality.
Renal denervation for resistant hypertension.
Almeida, Manuel de Sousa; Gonçalves, Pedro de Araújo; Oliveira, Eduardo Infante de; Carvalho, Henrique Cyrne de
2015-02-01
There is a marked contrast between the high prevalence of hypertension and the low rates of adequate control. A subset of patients with suboptimal blood pressure control have drug-resistant hypertension, in the pathophysiology of which chronic sympathetic hyperactivation is significantly involved. Sympathetic renal denervation has recently emerged as a device-based treatment for resistant hypertension. In this review, the pathophysiological mechanisms linking the sympathetic nervous system and cardiovascular disease are reviewed, focusing on resistant hypertension and the role of sympathetic renal denervation. An update on experimental and clinical results is provided, along with potential future indications for this device-based technique in other cardiovascular diseases. Copyright © 2014 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.
In search of a consensus model of the resting state of a voltage-sensing domain.
Vargas, Ernesto; Bezanilla, Francisco; Roux, Benoît
2011-12-08
Voltage-sensing domains (VSDs) undergo conformational changes in response to the membrane potential and are the critical structural modules responsible for the activation of voltage-gated channels. Structural information about the key conformational states underlying voltage activation is currently incomplete. Through the use of experimentally determined residue-residue interactions as structural constraints, we determine and refine a model of the Kv channel VSD in the resting conformation. The resulting structural model is in broad agreement with results that originate from various labs using different techniques, indicating the emergence of a consensus for the structural basis of voltage sensing. Copyright © 2011 Elsevier Inc. All rights reserved.
Focusing on optic tectum circuitry through the lens of genetics.
Nevin, Linda M; Robles, Estuardo; Baier, Herwig; Scott, Ethan K
2010-09-28
The visual pathway is tasked with processing incoming signals from the retina and converting this information into adaptive behavior. Recent studies of the larval zebrafish tectum have begun to clarify how the 'micro-circuitry' of this highly organized midbrain structure filters visual input, which arrives in the superficial layers and directs motor output through efferent projections from its deep layers. The new emphasis has been on the specific function of neuronal cell types, which can now be reproducibly labeled, imaged and manipulated using genetic and optical techniques. Here, we discuss recent advances and emerging experimental approaches for studying tectal circuits as models for visual processing and sensorimotor transformation by the vertebrate brain.
2017-06-01
physicochemical properties of complex organic chemicals. The CTS has capabilities for estimating chemical-specific properties in the absence of experimentally ...obtained properties; thus, CTS can help fill data gaps for properties, particularly for emerging MC that have limited experimental data. This report...specific properties in the absence of experimentally obtained properties; thus, CTS can help fill data gaps for properties, particularly for emerging
Nonlinear optical response and its theoretical modelling of Sb2S3 nanorod
NASA Astrophysics Data System (ADS)
Yadav, Rajesh Kumar; Barik, A. R.; Das, Amlan; Adarsh, K. V.
2018-05-01
Light-matter interaction in nanoscale regime have unprecedented and accelerating demand in optoelectronics, valley electronics and device applications. Such interaction in 1-dimention (1D) metal chalcogenides has emerged as an important research topic because of its possibility to custom design optical properties, implying enormous application including optical computers, communications, bioimaging, and so on. However, understanding of nonlinear optical response of these nanostructures is still lacking, although it constitutes an interesting problem on the light-matter interaction. Here, we have presented the nonlinear optical response in Sb2S3 nanorod using Z-scan technique. Our experimental findings show a strong saturable absorption (SA). In this context, we have numerically simulated the experimental result using two level rate equation. The solutions of these two-level rate equation for a Gaussian shaped pulse exactly replicated the experimental data. From the best numerical fit, we found excited state decay time (τ ≈ 0.15ns) and saturation intensity (IS ≈ 0.01 GW/cm2). Additionally, we have calculated number of career density (N ≈ 5.31 × 10-17 cm-3), ground state absorption cross section (σ1 ≈ 1.63 × 10-17 cm2). Our experimental finding indicates that they can be employed as saturable absorbers.
NASA Astrophysics Data System (ADS)
Remington, Bruce A.; Rudd, Robert E.; Wark, Justin S.
2015-09-01
Over the past 3 decades, there has been an exponential increase in work done in the newly emerging field of matter at extreme states of deformation and compression. This accelerating progress is due to the confluence of new experimental facilities, experimental techniques, theory, and simulations. Regimes of science hitherto thought out of reach in terrestrial settings are now being accessed routinely. High-pressure macroscopic states of matter are being experimentally studied on high-power lasers and pulsed power facilities, and next-generation light sources are probing the quantum response of matter at the atomic level. Combined, this gives experimental access to the properties and dynamics of matter from femtoseconds to microseconds in time scale and from kilobars to gigabars in pressure. There are a multitude of new regimes of science that are now accessible in laboratory settings. Examples include planetary formation dynamics, asteroid and meteor impact dynamics, space hardware response to hypervelocity dust and debris impacts, nuclear reactor component response to prolonged exposure to radiation damage, advanced research into light weight armor, capsule dynamics in inertial confinement fusion research, and the basic high energy density properties of matter. We review highlights and advances in this rapidly developing area of science and research.
Tan, Kei X; Lau, Sie Yon; Danquah, Michael K
2018-05-01
Targeted drug delivery is a promising strategy to promote effective delivery of conventional and emerging pharmaceuticals. The emergence of aptamers as superior targeting ligands to direct active drug molecules specifically to desired malignant cells has created new opportunities to enhance disease therapies. The application of biodegradable polymers as delivery carriers to develop aptamer-navigated drug delivery system is a promising approach to effectively deliver desired drug dosages to target cells. This study reports the development of a layer-by-layer aptamer-mediated drug delivery system (DPAP) via a w/o/w double emulsion technique homogenized by ultrasonication or magnetic stirring. Experimental results showed no significant differences in the biophysical characteristics of DPAP nanoparticles generated using the two homogenization techniques. The DPAP formulation demonstrated a strong targeting performance and selectivity towards its target receptor molecules in the presence of non-targets. The DPAP formulation demonstrated a controlled and sustained drug release profile under the conditions of pH 7 and temperature 37 °C. Also, the drug release rate of DPAP formulation was successfully accelerated under an endosomal acidic condition of ∼pH 5.5, indicating the potential to enhance drug delivery within the endosomal micro-environment. The findings from this work are useful to understanding polymer-aptamer-drug relationship and their impact on developing effective targeted delivery systems. Copyright © 2018 Elsevier Masson SAS. All rights reserved.
A formula for evaluating colour differences for thread sewn into fabric samples
NASA Astrophysics Data System (ADS)
Steder, Thorsten
In-service rails can develop several types of structural defects due to fatigue and wear caused by rolling stock passing over them. Most rail defects will develop gradually over time thus permitting inspection engineers to detect them in time before final failure occurs. In the UK, certain types of severe rail defects such as tache ovales, require the fitting of emergency clamps and the imposing of an Emergency Speed Restriction (ESR) until the defects are removed. Acoustic emission (AE) techniques can be applied for the detection and continuous monitoring of defect growth therefore removing the need of imposing strict ESRs. The work reported herewith aims to develop a sound methodology for the application of AE in order to detect and subsequently monitor damage evolution in rails. To validate the potential of the AE technique, tests have been carried out under laboratory conditions on three and four-point bending samples manufactured from 260 grade rail steel. Further tests, simulating the background noise conditions caused by passing rolling stock have been carried out using special experimental setups. The crack growth events have been simulated using a pencil tip break..
Handbook of emergency management for state-level transportation agencies.
DOT National Transportation Integrated Search
2010-03-01
The Department of Homeland Security has mandated specific systems and techniques for the management of emergencies in the United States, including the Incident Command System, the National Incident Management System, Emergency Operations Plans, Emerg...
ERIC Educational Resources Information Center
Kieran, Carolyn; Drijvers, Paul
2006-01-01
This paper addresses the dialectical relation between theoretical thinking and technique, as they co-emerge in a combined computer algebra (CAS) and paper-and-pencil environment. The theoretical framework in this ongoing study consists of the instrumental approach to tool use and an adaptation of Chevallard's anthropological theory. The main aim…
Kim, Sunghee; Shin, Gisoo
2016-02-01
Since previous studies on simulation-based education have been focused on fundamental nursing skills for nursing students in South Korea, there is little research available that focuses on clinical nurses in simulation-based training. Further, there is a paucity of research literature related to the integration of the nursing process into simulation training particularly in the emergency nursing care of high-risk maternal and neonatal patients. The purpose of this study was to identify the effects of nursing process-based simulation on knowledge, attitudes, and skills for maternal and child emergency nursing care in clinical nurses in South Korea. Data were collected from 49 nurses, 25 in the experimental group and 24 in the control group, from August 13 to 14, 2013. This study was an equivalent control group pre- and post-test experimental design to compare the differences in knowledge, attitudes, and skills for maternal and child emergency nursing care between the experimental group and the control group. The experimental group was trained by the nursing process-based simulation training program, while the control group received traditional methods of training for maternal and child emergency nursing care. The experimental group was more likely to improve knowledge, attitudes, and skills required for clinical judgment about maternal and child emergency nursing care than the control group. Among five stages of nursing process in simulation, the experimental group was more likely to improve clinical skills required for nursing diagnosis and nursing evaluation than the control group. These results will provide valuable information on developing nursing process-based simulation training to improve clinical competency in nurses. Further research should be conducted to verify the effectiveness of nursing process-based simulation with more diverse nurse groups on more diverse subjects in the future. Copyright © 2015 Elsevier Ltd. All rights reserved.
Cellular-based preemption system
NASA Technical Reports Server (NTRS)
Bachelder, Aaron D. (Inventor)
2011-01-01
A cellular-based preemption system that uses existing cellular infrastructure to transmit preemption related data to allow safe passage of emergency vehicles through one or more intersections. A cellular unit in an emergency vehicle is used to generate position reports that are transmitted to the one or more intersections during an emergency response. Based on this position data, the one or more intersections calculate an estimated time of arrival (ETA) of the emergency vehicle, and transmit preemption commands to traffic signals at the intersections based on the calculated ETA. Additional techniques may be used for refining the position reports, ETA calculations, and the like. Such techniques include, without limitation, statistical preemption, map-matching, dead-reckoning, augmented navigation, and/or preemption optimization techniques, all of which are described in further detail in the above-referenced patent applications.
Emergency cricothyrotomy-a comparative study of different techniques in human cadavers.
Schober, Patrick; Hegemann, Martina C; Schwarte, Lothar A; Loer, Stephan A; Noetges, Peter
2009-02-01
Emergency cricothyrotomy is the final lifesaving option in "cannot intubate-cannot ventilate" situations. Fast, efficient and safe management is indispensable to reestablish oxygenation, thus the quickest, most reliable and safest technique should be used. Several cricothyrotomy techniques exist, which can be grouped into two categories: anatomical-surgical and puncture. We studied success rate, tracheal tube insertion time and complications of different techniques, including a novel cricothyrotomy scissors technique in human cadavers. Sixty-three inexperienced health care providers were randomly assigned to apply either an anatomical-surgical technique (standard surgical technique, n=18; novel cricothyrotomy scissors technique, n=14) or a puncture technique (catheter-over-needle technique, n=17; wire-guided technique, n=14). Airway access was almost always successful with the anatomical-surgical techniques (success rate in standard surgical group 94%, scissors group 100%). In contrast, the success rate was smaller (p<0.05) with the puncture techniques (catheter-over-needle group 82%, wire-guided technique 71%). Tracheal tube insertion time was faster overall (p<0.05) with anatomical-surgical techniques (standard surgical 78s [54-135], novel cricothyrotomy scissors technique 60s [42-82]; median [IQR]) than with puncture techniques (catheter-over-needle technique 74s [48-145], wire-guided technique 135s [116-307]). We observed fewer complications with anatomical-surgical techniques than with puncture techniques (p<0.001). In inexperienced health care personnel, anatomical-surgical techniques showed a higher success rate, a faster tracheal tube insertion time and a lower complication rate compared with puncture techniques, suggesting that they may be the techniques of choice in emergencies.
Computational micromechanics of fatigue of microstructures in the HCF–VHCF regimes
DOE Office of Scientific and Technical Information (OSTI.GOV)
Castelluccio, Gustavo M.; Musinski, William D.; McDowell, David L.
Advances in higher resolution experimental techniques have shown that metallic materials can develop fatigue cracks under cyclic loading levels significantly below the yield stress. Indeed, the traditional notion of a fatigue limit can be recast in terms of limits associated with nucleation and arrest of fatigue cracks at the microstructural scale. Though fatigue damage characteristically emerges from irreversible dislocation processes at sub-grain scales, the specific microstructure attributes, environment, and loading conditions can strongly affect the apparent failure mode and surface to subsurface transitions. This paper discusses multiple mechanisms that occur during fatigue loading in the high cycle fatigue (HCF) tomore » very high cycle fatigue (VHCF) regimes. We compare these regimes, focusing on strategies to bridge experimental and modeling approaches exercised at multiple length scales and discussing particular challenges to modeling and simulation regarding microstructure-sensitive fatigue driving forces and thresholds. Finally, we discuss some of the challenges in predicting the transition of failure mechanisms at different stress and strain amplitudes.« less
Aoun, Fouad; Marcelis, Quentin; Roumeguère, Thierry
2015-01-01
Benign prostatic hyperplasia (BPH) represents a spectrum of related lower urinary tract symptoms (LUTS). The cost of currently recommended medications and the discontinuation rate due to side effects are significant drawbacks limiting their long-term use in clinical practice. Interventional procedures, considered as the definitive treatment for BPH, carry a significant risk of treatment-related complications in frail patients. These issues have contributed to the emergence of new approaches as alternative options to standard therapies. This paper reviews the recent literature regarding the experimental treatments under investigation and presents the currently available experimental devices and techniques used under local anesthesia for the treatment of LUTS/BPH in the vast majority of cases. Devices for delivery of thermal treatment (microwaves, radiofrequency, high-intensity focused ultrasound, and the Rezum system), mechanical devices (prostatic stent and urethral lift), fractionation of prostatic tissue (histotripsy and aquablation), prostate artery embolization, and intraprostatic drugs are discussed. Evidence for the safety, tolerability, and efficacy of these “minimally invasive procedures” is analyzed. PMID:26317083
The center for expanded data annotation and retrieval
Bean, Carol A; Cheung, Kei-Hoi; Dumontier, Michel; Durante, Kim A; Gevaert, Olivier; Gonzalez-Beltran, Alejandra; Khatri, Purvesh; Kleinstein, Steven H; O’Connor, Martin J; Pouliot, Yannick; Rocca-Serra, Philippe; Sansone, Susanna-Assunta; Wiser, Jeffrey A
2015-01-01
The Center for Expanded Data Annotation and Retrieval is studying the creation of comprehensive and expressive metadata for biomedical datasets to facilitate data discovery, data interpretation, and data reuse. We take advantage of emerging community-based standard templates for describing different kinds of biomedical datasets, and we investigate the use of computational techniques to help investigators to assemble templates and to fill in their values. We are creating a repository of metadata from which we plan to identify metadata patterns that will drive predictive data entry when filling in metadata templates. The metadata repository not only will capture annotations specified when experimental datasets are initially created, but also will incorporate links to the published literature, including secondary analyses and possible refinements or retractions of experimental interpretations. By working initially with the Human Immunology Project Consortium and the developers of the ImmPort data repository, we are developing and evaluating an end-to-end solution to the problems of metadata authoring and management that will generalize to other data-management environments. PMID:26112029
Gene expression profiling--Opening the black box of plant ecosystem responses to global change
DOE Office of Scientific and Technical Information (OSTI.GOV)
Leakey, A.D.B.; Ainsworth, E.A.; Bernard, S.M.
The use of genomic techniques to address ecological questions is emerging as the field of genomic ecology. Experimentation under environmentally realistic conditions to investigate the molecular response of plants to meaningful changes in growth conditions and ecological interactions is the defining feature of genomic ecology. Since the impact of global change factors on plant performance are mediated by direct effects at the molecular, biochemical and physiological scales, gene expression analysis promises important advances in understanding factors that have previously been consigned to the 'black box' of unknown mechanism. Various tools and approaches are available for assessing gene expression in modelmore » and non-model species as part of global change biology studies. Each approach has its own unique advantages and constraints. A first generation of genomic ecology studies in managed ecosystems and mesocosms have provided a testbed for the approach and have begun to reveal how the experimental design and data analysis of gene expression studies can be tailored for use in an ecological context.« less
Probing noncommutative theories with quantum optical experiments
NASA Astrophysics Data System (ADS)
Dey, Sanjib; Bhat, Anha; Momeni, Davood; Faizal, Mir; Ali, Ahmed Farag; Dey, Tarun Kumar; Rehman, Atikur
2017-11-01
One of the major difficulties of modern science underlies at the unification of general relativity and quantum mechanics. Different approaches towards such theory have been proposed. Noncommutative theories serve as the root of almost all such approaches. However, the identification of the appropriate passage to quantum gravity is suffering from the inadequacy of experimental techniques. It is beyond our ability to test the effects of quantum gravity thorough the available scattering experiments, as it is unattainable to probe such high energy scale at which the effects of quantum gravity appear. Here we propose an elegant alternative scheme to test such theories by detecting the deformations emerging from the noncommutative structures. Our protocol relies on the novelty of an opto-mechanical experimental setup where the information of the noncommutative oscillator is exchanged via the interaction with an optical pulse inside an optical cavity. We also demonstrate that our proposal is within the reach of current technology and, thus, it could uncover a feasible route towards the realization of quantum gravitational phenomena thorough a simple table-top experiment.
Directed Nanopatterning with Nonlinear Laser Lithography
NASA Astrophysics Data System (ADS)
Tokel, Onur; Yavuz, Ozgun; Ergecen, Emre; Pavlov, Ihor; Makey, Ghaith; Ilday, Fatih Omer
In spite of the successes of maskless optical nanopatterning methods, it remains extremely challenging to create any isotropic, periodic nanopattern. Further, available optical techniques lack the long-range coverage and high periodicity demanded by photonics and photovoltaics applications. Here, we provide a novel solution with Nonlinear Laser Lithography (NLL) approach. Notably, we demonstrate that self-organized nanopatterns can be produced in all possible Bravais lattice types. Further, we show that carefully chosen defects or structued noise can direct NLL symmetries. Exploitation of directed self-organizatio to select or guide to predetermined symmetries is a new capability. Predictive capabilities for such far-from-equilibrium, dissipative systems is very limited due to a lack of experimental systems with predictive models. Here we also present a completely predictive model, and experimentally confirm that the emergence of motifs can be regulated by engineering defects, while the polarization of the ultrafast laser prescribes lattice symmetry, which in turn reinforces translational invariance. Thus, NLL enables a novel, maskless nanofabrication approach, where laser-induced nanopatterns can be rapidly created in any lattice symmetry
Computational micromechanics of fatigue of microstructures in the HCF–VHCF regimes
Castelluccio, Gustavo M.; Musinski, William D.; McDowell, David L.
2016-05-19
Advances in higher resolution experimental techniques have shown that metallic materials can develop fatigue cracks under cyclic loading levels significantly below the yield stress. Indeed, the traditional notion of a fatigue limit can be recast in terms of limits associated with nucleation and arrest of fatigue cracks at the microstructural scale. Though fatigue damage characteristically emerges from irreversible dislocation processes at sub-grain scales, the specific microstructure attributes, environment, and loading conditions can strongly affect the apparent failure mode and surface to subsurface transitions. This paper discusses multiple mechanisms that occur during fatigue loading in the high cycle fatigue (HCF) tomore » very high cycle fatigue (VHCF) regimes. We compare these regimes, focusing on strategies to bridge experimental and modeling approaches exercised at multiple length scales and discussing particular challenges to modeling and simulation regarding microstructure-sensitive fatigue driving forces and thresholds. Finally, we discuss some of the challenges in predicting the transition of failure mechanisms at different stress and strain amplitudes.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Fox, Zachary; Neuert, Gregor; Department of Pharmacology, School of Medicine, Vanderbilt University, Nashville, Tennessee 37232
2016-08-21
Emerging techniques now allow for precise quantification of distributions of biological molecules in single cells. These rapidly advancing experimental methods have created a need for more rigorous and efficient modeling tools. Here, we derive new bounds on the likelihood that observations of single-cell, single-molecule responses come from a discrete stochastic model, posed in the form of the chemical master equation. These strict upper and lower bounds are based on a finite state projection approach, and they converge monotonically to the exact likelihood value. These bounds allow one to discriminate rigorously between models and with a minimum level of computational effort.more » In practice, these bounds can be incorporated into stochastic model identification and parameter inference routines, which improve the accuracy and efficiency of endeavors to analyze and predict single-cell behavior. We demonstrate the applicability of our approach using simulated data for three example models as well as for experimental measurements of a time-varying stochastic transcriptional response in yeast.« less
Rotational Spectra of Adrenaline and Noradrenaline
NASA Astrophysics Data System (ADS)
Cortijo, V.; López, J. C.; Alonso, J. L.
2009-06-01
The emergence of Laser Ablation Molecular Beam Fourier Transform Microwave (LA-MB-FTMW) spectroscopy has rendered accessible the gas-phase study of solid biomolecules with high melting points. Among the biomolecules to benefit from this technique, neurotransmitters have received special attention due to the lack of experimental information and their biological relevance. As a continuation of the we present the study of adrenaline and noradrenaline. The comparison between the experimental rotational and ^{14}N nuclear quadrupole coupling constants and those calculated ab initio provide a definitive test for molecular structures and confirm unambiguously the identification of four conformers of adrenaline and three conformers of noradrenaline. Their relative population in the jet has been evaluated by relative intensity measurements of selected rotational transitions. The most abundant conformer in both neurotransmitters present an extended AG configuration with a O-H\\cdotsN hydrogen bond in the side chain. J.L. Alonso, M.E. Sanz, J.C. López and V. Cortijo, J. Am. Chem. Soc. (in press), 2009
NASA Astrophysics Data System (ADS)
Akaki, Mitsuru; Yoshizawa, Daichi; Okutani, Akira; Kida, Takanori; Romhányi, Judit; Penc, Karlo; Hagiwara, Masayuki
2017-12-01
Exotic spin-multipolar ordering in spin transition metal insulators has so far eluded unambiguous experimental observation. A less studied, but perhaps more feasible fingerprint of multipole character emerges in the excitation spectrum in the form of quadrupolar transitions. Such multipolar excitations are desirable as they can be manipulated with the use of light or electric field and can be captured by means of conventional experimental techniques. Here we study single crystals of multiferroic Sr2CoGe2O7 and observe a two-magnon spin excitation appearing above the saturation magnetic field in electron spin resonance (ESR) spectra. Our analysis of the selection rules reveals that this spin excitation mode does not couple to the magnetic component of the light, but it is excited by the electric field only, in full agreement with the theoretical calculations. Due to the nearly isotropic nature of Sr2CoGe2O7 , we identify this excitation as a purely spin-quadrupolar two-magnon mode.
Simma, Leopold; Cincotta, Domenic; Sabato, Stefan; Long, Elliot
2017-09-01
Airway emergencies presenting to the emergency department (ED) are usually managed with conventional equipment and techniques. The patient group managed urgently in the operating room (OR) has not been described. This study aims to describe a case series of children presenting to the ED with airway emergencies managed urgently in the OR, particularly the anaesthetic equipment and techniques used and airway findings. A retrospective cohort study undertaken at The Royal Children's Hospital, Melbourne, Australia. All patients presenting to the ED between 1 January 2012 and 30 July 2015 (42 months) with an airway emergency who were subsequently managed in the OR were included. Patient characteristics, anaesthetic equipment and technique and airway findings were recorded. Twenty-two airway emergencies in 21 patients were included over the study period, on average one every 2 months. Median age was 18 months and 43% were male. Inhalational induction was used in 77.3%, combined inhalational and intravenous induction in 9.1%, and intravenous induction alone in 13.6%. The most commonly used inhalational induction agent was sevoflurane, and the most commonly used intravenous induction agents were ketamine and propofol. Ten airway emergencies did not require intubation, seven for removal of inhaled foreign body, two with progressive tracheal stenosis requiring emergent dilatation and one examination under anaesthesia to rule out inhaled foreign body. Of the 12 airway emergencies that required immediate intubation, direct laryngoscopy was used in 9 and fibre-optic intubating bronchoscopy in 3. For intubations performed by direct laryngoscopy, one was difficult (Cormack and Lehane grade 3). First pass success was 83.3%. Adverse events occurred in 3/22 (13.6%) cases. Advanced airway techniques, including inhalational induction and intubation via fibre-optic intubating bronchoscope, are rarely but predictably required in the management of patients presenting to the ED. Institutions caring for children should prepare in advance where such patients should be managed, by whom, and provide equipment and training for their care. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
Architectural-level power estimation and experimentation
NASA Astrophysics Data System (ADS)
Ye, Wu
With the emergence of a plethora of embedded and portable applications and ever increasing integration levels, power dissipation of integrated circuits has moved to the forefront as a design constraint. Recent years have also seen a significant trend towards designs starting at the architectural (or RT) level. Those demand accurate yet fast RT level power estimation methodologies and tools. This thesis addresses issues and experiments associate with architectural level power estimation. An execution driven, cycle-accurate RT level power simulator, SimplePower, was developed using transition-sensitive energy models. It is based on the architecture of a five-stage pipelined RISC datapath for both 0.35mum and 0.8mum technology and can execute the integer subset of the instruction set of SimpleScalar . SimplePower measures the energy consumed in the datapath, memory and on-chip buses. During the development of SimplePower , a partitioning power modeling technique was proposed to model the energy consumed in complex functional units. The accuracy of this technique was validated with HSPICE simulation results for a register file and a shifter. A novel, selectively gated pipeline register optimization technique was proposed to reduce the datapath energy consumption. It uses the decoded control signals to selectively gate the data fields of the pipeline registers. Simulation results show that this technique can reduce the datapath energy consumption by 18--36% for a set of benchmarks. A low-level back-end compiler optimization, register relabeling, was applied to reduce the on-chip instruction cache data bus switch activities. Its impact was evaluated by SimplePower. Results show that it can reduce the energy consumed in the instruction data buses by 3.55--16.90%. A quantitative evaluation was conducted for the impact of six state-of-art high-level compilation techniques on both datapath and memory energy consumption. The experimental results provide a valuable insight for designers to develop future power-aware compilation frameworks for embedded systems.
Zhang, Fan; Allen, Andrew J; Levine, Lyle E; Mancini, Derrick C; Ilavsky, Jan
2015-05-01
The needs both for increased experimental throughput and for in operando characterization of functional materials under increasingly realistic experimental conditions have emerged as major challenges across the whole of crystallography. A novel measurement scheme that allows multiplexed simultaneous measurements from multiple nearby sample volumes is presented. This new approach enables better measurement statistics or direct probing of heterogeneous structure, dynamics or elemental composition. To illustrate, the submicrometer precision that optical lithography provides has been exploited to create a multiplexed form of ultra-small-angle scattering based X-ray photon correlation spectroscopy (USAXS-XPCS) using micro-slit arrays fabricated by photolithography. Multiplexed USAXS-XPCS is applied to follow the equilibrium dynamics of a simple colloidal suspension. While the dependence of the relaxation time on momentum transfer, and its relationship with the diffusion constant and the static structure factor, follow previous findings, this measurements-in-parallel approach reduces the statistical uncertainties of this photon-starved technique to below those associated with the instrument resolution. More importantly, we note the potential of the multiplexed scheme to elucidate the response of different components of a heterogeneous sample under identical experimental conditions in simultaneous measurements. In the context of the X-ray synchrotron community, this scheme is, in principle, applicable to all in-line synchrotron techniques. Indeed, it has the potential to open a new paradigm for in operando characterization of heterogeneous functional materials, a situation that will be even further enhanced by the ongoing development of multi-bend achromat storage ring designs as the next evolution of large-scale X-ray synchrotron facilities around the world.
NASA Astrophysics Data System (ADS)
Chun, Chan; Haohua, Wen; Lanyuan, Lu; Jun, Fan
2016-01-01
Membrane curvature is no longer thought of as a passive property of the membrane; rather, it is considered as an active, regulated state that serves various purposes in the cell such as between cells and organelle definition. While transport is usually mediated by tiny membrane bubbles known as vesicles or membrane tubules, such communication requires complex interplay between the lipid bilayers and cytosolic proteins such as members of the Bin/Amphiphysin/Rvs (BAR) superfamily of proteins. With rapid developments in novel experimental techniques, membrane remodeling has become a rapidly emerging new field in recent years. Molecular dynamics (MD) simulations are important tools for obtaining atomistic information regarding the structural and dynamic aspects of biological systems and for understanding the physics-related aspects. The availability of more sophisticated experimental data poses challenges to the theoretical community for developing novel theoretical and computational techniques that can be used to better interpret the experimental results to obtain further functional insights. In this review, we summarize the general mechanisms underlying membrane remodeling controlled or mediated by proteins. While studies combining experiments and molecular dynamics simulations recall existing mechanistic models, concurrently, they extend the role of different BAR domain proteins during membrane remodeling processes. We review these recent findings, focusing on how multiscale molecular dynamics simulations aid in understanding the physical basis of BAR domain proteins, as a representative of membrane-remodeling proteins. Project supported by the National Natural Science Foundation of China (Grant No. 21403182) and the Research Grants Council of Hong Kong, China (Grant No. CityU 21300014).
ERIC Educational Resources Information Center
Reese-Weber, Marla
2008-01-01
The present study provides experimental data comparing emerging adults' attitudes toward dating and sibling violence in adolescence using a new methodology in which participants observe a violent interaction between adolescents. The reported amount of violence experienced in dating and sibling relationships among emerging adults is also compared.…
2016 Emerging Technology Domains Risk Survey
2016-04-05
2016 Emerging Technology Domains Risk Survey Christopher King Dan Klinedinst Todd Lewellen Garret Wassermann April 2016 TECHNICAL REPORT...Unlimited [Checkoway 2011] Checkoway, Stephen; McCoy, Damon; Kantor, Brian; Anderson, Danny; Shacham, Hovav; Savage, Stefan. Comprehensive Experimental ...Koscher 2010] Koscher, Karl et al. “ Experimental Security Analysis of a Modern Automobile,” 447-462. IEEE Symposium on Security and Privacy
Demography and Public Health Emergency Preparedness: Making the Connection
Katz, Rebecca
2009-01-01
The tools and techniques of population sciences are extremely relevant to the discipline of public health emergency preparedness: protecting and securing the population’s health requires information about that population. While related fields such as security studies have successfully integrated demographic tools into their research and literature, the theoretical and practical connection between the methods of demography and the practice of public health emergency preparedness is weak. This article suggests the need to further the interdisciplinary use of demography by examining the need for a systematic use of population science techniques in public health emergency preparedness. Ultimately, we demonstrate how public health emergency preparedness can incorporate demography to develop more effective preparedness plans. Important policy implications emerge: demographers and preparedness experts need to collaborate more formally in order to facilitate community resilience and mitigate the consequences of public health emergencies. PMID:20694030
Measurement and control of detailed electronic properties in a single molecule break junction.
Wang, Kun; Hamill, Joseph; Zhou, Jianfeng; Guo, Cunlan; Xu, Bingqian
2014-01-01
The lack of detailed experimental controls has been one of the major obstacles hindering progress in molecular electronics. While large fluctuations have been occurring in the experimental data, specific details, related mechanisms, and data analysis techniques are in high demand to promote our physical understanding at the single-molecule level. A series of modulations we recently developed, based on traditional scanning probe microscopy break junctions (SPMBJs), have helped to discover significant properties in detail which are hidden in the contact interfaces of a single-molecule break junction (SMBJ). For example, in the past we have shown that the correlated force and conductance changes under the saw tooth modulation and stretch-hold mode of PZT movement revealed inherent differences in the contact geometries of a molecular junction. In this paper, using a bias-modulated SPMBJ and utilizing emerging data analysis techniques, we report on the measurement of the altered alignment of the HOMO of benzene molecules with changing the anchoring group which coupled the molecule to metal electrodes. Further calculations based on Landauer fitting and transition voltage spectroscopy (TVS) demonstrated the effects of modulated bias on the location of the frontier molecular orbitals. Understanding the alignment of the molecular orbitals with the Fermi level of the electrodes is essential for understanding the behaviour of SMBJs and for the future design of more complex devices. With these modulations and analysis techniques, fruitful information has been found about the nature of the metal-molecule junction, providing us insightful clues towards the next step for in-depth study.
Yi, Doogab
2008-01-01
The existing literature on the development of recombinant DNA technology and genetic engineering tends to focus on Stanley Cohen and Herbert Boyer's recombinant DNA cloning technology and its commercialization starting in the mid-1970s. Historians of science, however, have pointedly noted that experimental procedures for making recombinant DNA molecules were initially developed by Stanford biochemist Paul Berg and his colleagues, Peter Lobban and A. Dale Kaiser in the early 1970s. This paper, recognizing the uneasy disjuncture between scientific authorship and legal invention in the history of recombinant DNA technology, investigates the development of recombinant DNA technology in its full scientific context. I do so by focusing on Stanford biochemist Berg's research on the genetic regulation of higher organisms. As I hope to demonstrate, Berg's new venture reflected a mass migration of biomedical researchers as they shifted from studying prokaryotic organisms like bacteria to studying eukaryotic organisms like mammalian and human cells. It was out of this boundary crossing from prokaryotic to eukaryotic systems through virus model systems that recombinant DNA technology and other significant new research techniques and agendas emerged. Indeed, in their attempt to reconstitute 'life' as a research technology, Stanford biochemists' recombinant DNA research recast genes as a sequence that could be rewritten thorough biochemical operations. The last part of this paper shifts focus from recombinant DNA technology's academic origins to its transformation into a genetic engineering technology by examining the wide range of experimental hybridizations which occurred as techniques and knowledge circulated between Stanford biochemists and the Bay Area's experimentalists. Situating their interchange in a dense research network based at Stanford's biochemistry department, this paper helps to revise the canonized history of genetic engineering's origins that emerged during the patenting of Cohen-Boyer's recombinant DNA cloning procedures.
Review of the Potential of the Ni/Cu Plating Technique for Crystalline Silicon Solar Cells
Rehman, Atteq ur; Lee, Soo Hong
2014-01-01
Developing a better method for the metallization of silicon solar cells is integral part of realizing superior efficiency. Currently, contact realization using screen printing is the leading technology in the silicon based photovoltaic industry, as it is simple and fast. However, the problem with metallization of this kind is that it has a lower aspect ratio and higher contact resistance, which limits solar cell efficiency. The mounting cost of silver pastes and decreasing silicon wafer thicknesses encourages silicon solar cell manufacturers to develop fresh metallization techniques involving a lower quantity of silver usage and not relying pressing process of screen printing. In recent times nickel/copper (Ni/Cu) based metal plating has emerged as a metallization method that may solve these issues. This paper offers a detailed review and understanding of a Ni/Cu based plating technique for silicon solar cells. The formation of a Ni seed layer by adopting various deposition techniques and a Cu conducting layer using a light induced plating (LIP) process are appraised. Unlike screen-printed metallization, a step involving patterning is crucial for opening the masking layer. Consequently, experimental procedures involving patterning methods are also explicated. Lastly, the issues of adhesion, back ground plating, process complexity and reliability for industrial applications are also addressed. PMID:28788516
Review of the Potential of the Ni/Cu Plating Technique for Crystalline Silicon Solar Cells.
Rehman, Atteq Ur; Lee, Soo Hong
2014-02-18
Developing a better method for the metallization of silicon solar cells is integral part of realizing superior efficiency. Currently, contact realization using screen printing is the leading technology in the silicon based photovoltaic industry, as it is simple and fast. However, the problem with metallization of this kind is that it has a lower aspect ratio and higher contact resistance, which limits solar cell efficiency. The mounting cost of silver pastes and decreasing silicon wafer thicknesses encourages silicon solar cell manufacturers to develop fresh metallization techniques involving a lower quantity of silver usage and not relying pressing process of screen printing. In recent times nickel/copper (Ni/Cu) based metal plating has emerged as a metallization method that may solve these issues. This paper offers a detailed review and understanding of a Ni/Cu based plating technique for silicon solar cells. The formation of a Ni seed layer by adopting various deposition techniques and a Cu conducting layer using a light induced plating (LIP) process are appraised. Unlike screen-printed metallization, a step involving patterning is crucial for opening the masking layer. Consequently, experimental procedures involving patterning methods are also explicated. Lastly, the issues of adhesion, back ground plating, process complexity and reliability for industrial applications are also addressed.
NASA Astrophysics Data System (ADS)
Pramodini, S.; Sudhakar, Y. N.; SelvaKumar, M.; Poornesh, P.
2014-04-01
We present the synthesis and characterization of third-order optical nonlinearity and optical limiting of the conducting polymers poly (aniline-co-o-anisidine) and poly (aniline-co-pyrrole). Nonlinear optical studies were carried out by employing the z-scan technique using a He-Ne laser operating in continuous wave mode at 633 nm. The copolymers exhibited a reverse saturable absorption process and self-defocusing properties under the experimental conditions. The estimated values of βeff, n2 and χ(3) were found to be of the order of 10-2 cm W-1, 10-5 esu and 10-7 esu respectively. Self-diffraction rings were observed due to refractive index change when exposed to the laser beam. The copolymers possess a lower limiting threshold and clamping level, which is essential to a great extent for power limiting devices. Therefore, copolymers of aniline emerge as a potential candidate for nonlinear optical device applications.
T-L Plane Abstraction-Based Energy-Efficient Real-Time Scheduling for Multi-Core Wireless Sensors
Kim, Youngmin; Lee, Ki-Seong; Pham, Ngoc-Son; Lee, Sun-Ro; Lee, Chan-Gun
2016-01-01
Energy efficiency is considered as a critical requirement for wireless sensor networks. As more wireless sensor nodes are equipped with multi-cores, there are emerging needs for energy-efficient real-time scheduling algorithms. The T-L plane-based scheme is known to be an optimal global scheduling technique for periodic real-time tasks on multi-cores. Unfortunately, there has been a scarcity of studies on extending T-L plane-based scheduling algorithms to exploit energy-saving techniques. In this paper, we propose a new T-L plane-based algorithm enabling energy-efficient real-time scheduling on multi-core sensor nodes with dynamic power management (DPM). Our approach addresses the overhead of processor mode transitions and reduces fragmentations of the idle time, which are inherent in T-L plane-based algorithms. Our experimental results show the effectiveness of the proposed algorithm compared to other energy-aware scheduling methods on T-L plane abstraction. PMID:27399722
Experimental Study of Flow Through Carotid Aneurysms
NASA Astrophysics Data System (ADS)
Masoomi, Faezeh; Mejia-Alvarez, Ricardo
2017-11-01
There is evidence that traditional endovascular techniques like coiling are not effective for treatment of wide-neck cerebral aneurysms. Flow Diverter Stents (FDS) have emerged as promising devices for treating complex aneurysms since they enable treatment of aneurysms that were considered untreatable before. Recent studies suggest a number of associated risks with FDS, including in-stent thrombosis, perianeurysmal edema, delayed hemorrhage, and perforator occlusions. Chong et al. simulated hemodynamic behavior using patient-specific data. From their study, it is possible to infer that the standard deviation of energy loss could be a good predictor for intervention success. The aim of this study is to investigate the flow in models of cerebral aneurysms before and after FDS insertion using PIV. These models will be based on actual clinical studies and will be fabricated with advanced additive manufacturing techniques. These data will then be used to explore flow parameters that could inform the likelihood of post-intervention aneurysm rupture, and help determine FDS designs that better suit any particular patient before its procedure.
NASA Astrophysics Data System (ADS)
Shen, Feng; Wayn Cheong, Joon; Dempster, Andrew G.
2015-04-01
Relative position awareness is a vital premise for the implementation of emerging intelligent transportation systems, such as collision warning. However, commercial global navigation satellite systems (GNSS) receivers do not satisfy the requirements of these applications. Fortunately, cooperative positioning (CP) techniques, through sharing the GNSS measurements between vehicles, can improve the performance of relative positioning in a vehicular ad hoc network (VANET). In this paper, while assuming there are no obstacles between vehicles, a new enhanced tightly coupled CP technique is presented by adding ultra-wide bandwidth (UWB)-based inter-vehicular range measurements. In the proposed CP method, each vehicle fuses the GPS measurements and the inter-vehicular range measurements. Based on analytical and experimental results, in the full GPS coverage environment, the new tight integration CP method outperforms the INS-aided tight CP method, tight CP method, and DGPS by 11%, 15%, and 24%, respectively; in the GPS outage scenario, the performance improvement achieves 60%, 65%, and 73%, respectively.
A Parallel 2D Numerical Simulation of Tumor Cells Necrosis by Local Hyperthermia
NASA Astrophysics Data System (ADS)
Reis, R. F.; Loureiro, F. S.; Lobosco, M.
2014-03-01
Hyperthermia has been widely used in cancer treatment to destroy tumors. The main idea of the hyperthermia is to heat a specific region like a tumor so that above a threshold temperature the tumor cells are destroyed. This can be accomplished by many heat supply techniques and the use of magnetic nanoparticles that generate heat when an alternating magnetic field is applied has emerged as a promise technique. In the present paper, the Pennes bioheat transfer equation is adopted to model the thermal tumor ablation in the context of magnetic nanoparticles. Numerical simulations are carried out considering different injection sites for the nanoparticles in an attempt to achieve better hyperthermia conditions. Explicit finite difference method is employed to solve the equations. However, a large amount of computation is required for this purpose. Therefore, this work also presents an initial attempt to improve performance using OpenMP, a parallel programming API. Experimental results were quite encouraging: speedups around 35 were obtained on a 64-core machine.
Alignment of an acoustic manipulation device with cepstral analysis of electronic impedance data.
Hughes, D A; Qiu, Y; Démoré, C; Weijer, C J; Cochran, S
2015-02-01
Acoustic particle manipulation is an emerging technology that uses ultrasonic standing waves to position objects with pressure gradients and acoustic radiation forces. To produce strong standing waves, the transducer and the reflector must be aligned properly such that they are parallel to each other. This can be a difficult process due to the need to visualise the ultrasound waves and as higher frequencies are introduced, this alignment requires higher accuracy. In this paper, we present a method for aligning acoustic resonators with cepstral analysis. This is a simple signal processing technique that requires only the electrical impedance measurement data of the resonator, which is usually recorded during the fabrication process of the device. We first introduce the mathematical basis of cepstral analysis and then demonstrate and validate it using a computer simulation of an acoustic resonator. Finally, the technique is demonstrated experimentally to create many parallel linear traps for 10 μm fluorescent beads inside an acoustic resonator. Copyright © 2014 Elsevier B.V. All rights reserved.
The basolateral amygdala in reward learning and addiction
Wassum, Kate M.; Izquierdo, Alicia
2015-01-01
Sophisticated behavioral paradigms partnered with the emergence of increasingly selective techniques to target the basolateral amygdala (BLA) have resulted in an enhanced understanding of the role of this nucleus in learning and using reward information. Due to the wide variety of behavioral approaches many questions remain on the circumscribed role of BLA in appetitive behavior. In this review, we integrate conclusions of BLA function in reward-related behavior using traditional interference techniques (lesion, pharmacological inactivation) with those using newer methodological approaches in experimental animals that allow in vivo manipulation of cell type-specific populations and neural recordings. Secondly, from a review of appetitive behavioral tasks in rodents and monkeys and recent computational models of reward procurement, we derive evidence for BLA as a neural integrator of reward value, history, and cost parameters. Taken together, BLA codes specific and temporally dynamic outcome representations in a distributed network to orchestrate adaptive responses. We provide evidence that experiences with opiates and psychostimulants alter these outcome representations in BLA, resulting in long-term modified action. PMID:26341938
Experimental implementation of acoustic impedance control by a 2D network of distributed smart cells
NASA Astrophysics Data System (ADS)
David, P.; Collet, M.; Cote, J.-M.
2010-03-01
New miniaturization and integration capabilities available from emerging microelectromechanical system (MEMS) technology will allow silicon-based artificial skins involving thousands of elementary actuators to be developed in the near future. Smart structures combining large arrays of elementary motion pixels are thus being studied so that fundamental properties could be dynamically adjusted. This paper investigates the acoustical capabilities of a network of distributed transducers connected with a suitable controlling strategy. The research aims at designing an integrated active interface for sound attenuation by using suitable changes of acoustical impedance. The control strategy is based on partial differential equations (PDE) and the multiscaled physics of electromechanical elements. Specific techniques based on PDE control theory have provided a simple boundary control equation able to annihilate the reflections of acoustic waves. To experimentally implement the method, the control strategy is discretized as a first order time-space operator. The obtained quasi-collocated architecture, composed of a large number of sensors and actuators, provides high robustness and stability. The experimental results demonstrate how a well controlled active skin can substantially modify sound reflectivity of the acoustical interface and reduce the propagation of acoustic waves.
Delayed Gamma-ray Spectroscopy for Safeguards Applications
DOE Office of Scientific and Technical Information (OSTI.GOV)
Mozin, Vladimir
The delayed gamma-ray assay technique utilizes an external neutron source (D-D, D-T, or electron accelerator-driven), and high-resolution gamma-ray spectrometers to perform characterization of SNM materials behind shielding and in complex configurations such as a nuclear fuel assembly. High-energy delayed gamma-rays (2.5 MeV and above) observed following the active interrogation, provide a signature for identification of specific fissionable isotopes in a mixed sample, and determine their relative content. Potential safeguards applications of this method are: 1) characterization of fresh and spent nuclear fuel assemblies in wet or dry storage; 2) analysis of uranium enrichment in shielded or non-characterized containers or inmore » the presence of a strong radioactive background and plutonium contamination; 3) characterization of bulk and waste and product streams at SNM processing plants. Extended applications can include warhead confirmation and warhead dismantlement confirmation in the arms control area, as well as SNM diagnostics for the emergency response needs. In FY16 and prior years, the project has demonstrated the delayed gamma-ray measurement technique as a robust SNM assay concept. A series of empirical and modeling studies were conducted to characterize its response sensitivity, develop analysis methodologies, and analyze applications. Extensive experimental tests involving weapons-grade Pu, HEU and depleted uranium samples were completed at the Idaho Accelerator Center and LLNL Dome facilities for various interrogation time regimes and effects of the neutron source parameters. A dedicated delayed gamma-ray response modeling technique was developed and its elements were benchmarked in representative experimental studies, including highresolution gamma-ray measurements of spent fuel at the CLAB facility in Sweden. The objective of the R&D effort in FY17 is to experimentally demonstrate the feasibility of the delayed gamma-ray interrogation of shielded SNM samples with portable neutron sources suitable for field applications.« less
ERIC Educational Resources Information Center
Agaku, Israel T.; Ayo-Yusuf, Olalekan A.
2014-01-01
Introduction: This study assessed the influence of exposure to pro-tobacco advertisements on experimentation with emerging tobacco products among U.S. adolescents aged =9 years, in Grades 6 to 12. Method: Data were obtained from the 2011 National Youth Tobacco Survey. Multivariate logistic regression was used to measure the association between…
ERIC Educational Resources Information Center
Kim, Shin-Jeong; Cho, Haeryun
2017-01-01
This study examined the effect of an intervention on coping knowledge among fifth- and sixth-grade elementary schoolchildren who received smartphone-delivered emergency preparedness education. This was a quasi-experimental study using a pre-/posttest design. Eighty-six children were recruited to participate. The children in the experimental group…
From gristle to chondrocyte transplantation: treatment of cartilage injuries
Lindahl, Anders
2015-01-01
This review addresses the progress in cartilage repair technology over the decades with an emphasis on cartilage regeneration with cell therapy. The most abundant cartilage is the hyaline cartilage that covers the surface of our joints and, due to avascularity, this tissue is unable to repair itself. The cartilage degeneration seen in osteoarthritis causes patient suffering and is a huge burden to society. The surgical approach to cartilage repair was non-existing until the 1950s when new surgical techniques emerged. The use of cultured cells for cell therapy started as experimental studies in the 1970s that developed over the years to a clinical application in 1994 with the introduction of the autologous chondrocyte transplantation technique (ACT). The technology is now spread worldwide and has been further refined by combining arthroscopic techniques with cells cultured on matrix (MACI technology). The non-regenerating hypothesis of cartilage has been revisited and we are now able to demonstrate cell divisions and presence of stem-cell niches in the joint. Furthermore, cartilage derived from human embryonic stem cells and induced pluripotent stem cells could be the base for new broader cell treatments for cartilage injuries and the future technology base for prevention and cure of osteoarthritis. PMID:26416680
Automated reuseable components system study results
NASA Technical Reports Server (NTRS)
Gilroy, Kathy
1989-01-01
The Automated Reusable Components System (ARCS) was developed under a Phase 1 Small Business Innovative Research (SBIR) contract for the U.S. Army CECOM. The objectives of the ARCS program were: (1) to investigate issues associated with automated reuse of software components, identify alternative approaches, and select promising technologies, and (2) to develop tools that support component classification and retrieval. The approach followed was to research emerging techniques and experimental applications associated with reusable software libraries, to investigate the more mature information retrieval technologies for applicability, and to investigate the applicability of specialized technologies to improve the effectiveness of a reusable component library. Various classification schemes and retrieval techniques were identified and evaluated for potential application in an automated library system for reusable components. Strategies for library organization and management, component submittal and storage, and component search and retrieval were developed. A prototype ARCS was built to demonstrate the feasibility of automating the reuse process. The prototype was created using a subset of the classification and retrieval techniques that were investigated. The demonstration system was exercised and evaluated using reusable Ada components selected from the public domain. A requirements specification for a production-quality ARCS was also developed.
Diagnostic imaging advances in murine models of colitis.
Brückner, Markus; Lenz, Philipp; Mücke, Marcus M; Gohar, Faekah; Willeke, Peter; Domagk, Dirk; Bettenworth, Dominik
2016-01-21
Inflammatory bowel diseases (IBD) such as Crohn's disease and ulcerative colitis are chronic-remittent inflammatory disorders of the gastrointestinal tract still evoking challenging clinical diagnostic and therapeutic situations. Murine models of experimental colitis are a vital component of research into human IBD concerning questions of its complex pathogenesis or the evaluation of potential new drugs. To monitor the course of colitis, to the present day, classical parameters like histological tissue alterations or analysis of mucosal cytokine/chemokine expression often require euthanasia of animals. Recent advances mean revolutionary non-invasive imaging techniques for in vivo murine colitis diagnostics are increasingly available. These novel and emerging imaging techniques not only allow direct visualization of intestinal inflammation, but also enable molecular imaging and targeting of specific alterations of the inflamed murine mucosa. For the first time, in vivo imaging techniques allow for longitudinal examinations and evaluation of intra-individual therapeutic response. This review discusses the latest developments in the different fields of ultrasound, molecularly targeted contrast agent ultrasound, fluorescence endoscopy, confocal laser endomicroscopy as well as tomographic imaging with magnetic resonance imaging, computed tomography and fluorescence-mediated tomography, discussing their individual limitations and potential future diagnostic applications in the management of human patients with IBD.
High accuracy switched-current circuits using an improved dynamic mirror
NASA Technical Reports Server (NTRS)
Zweigle, G.; Fiez, T.
1991-01-01
The switched-current technique, a recently developed circuit approach to analog signal processing, has emerged as an alternative/compliment to the well established switched-capacitor circuit technique. High speed switched-current circuits offer potential cost and power savings over slower switched-capacitor circuits. Accuracy improvements are a primary concern at this stage in the development of the switched-current technique. Use of the dynamic current mirror has produced circuits that are insensitive to transistor matching errors. The dynamic current mirror has been limited by other sources of error including clock-feedthrough and voltage transient errors. In this paper we present an improved switched-current building block using the dynamic current mirror. Utilizing current feedback the errors due to current imbalance in the dynamic current mirror are reduced. Simulations indicate that this feedback can reduce total harmonic distortion by as much as 9 dB. Additionally, we have developed a clock-feedthrough reduction scheme for which simulations reveal a potential 10 dB total harmonic distortion improvement. The clock-feedthrough reduction scheme also significantly reduces offset errors and allows for cancellation with a constant current source. Experimental results confirm the simulated improvements.
Density-cluster NMA: A new protein decomposition technique for coarse-grained normal mode analysis.
Demerdash, Omar N A; Mitchell, Julie C
2012-07-01
Normal mode analysis has emerged as a useful technique for investigating protein motions on long time scales. This is largely due to the advent of coarse-graining techniques, particularly Hooke's Law-based potentials and the rotational-translational blocking (RTB) method for reducing the size of the force-constant matrix, the Hessian. Here we present a new method for domain decomposition for use in RTB that is based on hierarchical clustering of atomic density gradients, which we call Density-Cluster RTB (DCRTB). The method reduces the number of degrees of freedom by 85-90% compared with the standard blocking approaches. We compared the normal modes from DCRTB against standard RTB using 1-4 residues in sequence in a single block, with good agreement between the two methods. We also show that Density-Cluster RTB and standard RTB perform well in capturing the experimentally determined direction of conformational change. Significantly, we report superior correlation of DCRTB with B-factors compared with 1-4 residue per block RTB. Finally, we show significant reduction in computational cost for Density-Cluster RTB that is nearly 100-fold for many examples. Copyright © 2012 Wiley Periodicals, Inc.
NASA Astrophysics Data System (ADS)
Zhao, Yang; Zhang, Lei; Zhao, Shu-Xia; Li, Yu-Fang; Gong, Yao; Dong, Lei; Ma, Wei-Guang; Yin, Wang-Bao; Yao, Shun-Chun; Lu, Ji-Dong; Xiao, Lian-Tuan; Jia, Suo-Tang
2016-12-01
Laser-induced breakdown spectroscopy (LIBS) is an emerging analytical spectroscopy technique. This review presents the main recent developments in China regarding the implementation of LIBS for coal analysis. The paper mainly focuses on the progress of the past few years in the fundamentals, data pretreatment, calibration model, and experimental issues of LIBS and its application to coal analysis. Many important domestic studies focusing on coal quality analysis have been conducted. For example, a proposed novel hybrid quantification model can provide more reproducible quantitative analytical results; the model obtained the average absolute errors (AREs) of 0.42%, 0.05%, 0.07%, and 0.17% for carbon, hydrogen, volatiles, and ash, respectively, and a heat value of 0.07 MJ/kg. Atomic/ionic emission lines and molecular bands, such as CN and C2, have been employed to generate more accurate analysis results, achieving an ARE of 0.26% and a 0.16% limit of detection (LOD) for the prediction of unburned carbon in fly ashes. Both laboratory and on-line LIBS apparatuses have been developed for field application in coal-fired power plants. We consider that both the accuracy and the repeatability of the elemental and proximate analysis of coal have increased significantly and further efforts will be devoted to realizing large-scale commercialization of coal quality analyzer in China.
Autonomous stress imaging cores: from concept to reality
NASA Astrophysics Data System (ADS)
van der Velden, Stephen; Rajic, Nik; Brooks, Chris; Galea, Steve
2016-04-01
The historical reliance of thermoelastic stress analysis on cooled infrared detection has created significant cost and practical impediments to the widespread use of this powerful full-field stress measurement technique. The emergence of low-cost microbolometers as a practical alternative has allowed for an expansion of the traditional role of thermoelastic stress analysis, and raises the possibility that it may in future become a viable structural health monitoring modality. Experimental results are shown to confirm that high resolution stress imagery can be obtained from an uncooled thermal camera core significantly smaller than any infrared imaging device previously applied to TSA. The paper provides a summary of progress toward the development of an autonomous stress-imaging capability based on this core.
NASA Technical Reports Server (NTRS)
Reid, Concha M.; Dobley, Arthur; Seymour, Frasier W.
2014-01-01
Lithium-air (Li-air) primary batteries have a theoretical specific capacity of 11,400 Wh/kg, the highest of any common metal-air system. NASA is developing Li-air technology for a Mobile Oxygen Concentrator for Spacecraft Emergencies, an application which requires an extremely lightweight primary battery that can discharge over 24 hours continuously. Several vendors were funded through the NASA SBIR program to develop Li-air technology to fulfill the requirements of this application. New catalysts and carbon cathode structures were developed to enhance the oxygen reduction reaction and increase surface area to improve cell performance. Techniques to stabilize the lithium metal anode surface were explored. Experimental results for prototype laboratory cells are given. Projections are made for the performance of hypothetical cells constructed from the materials that were developed.
Interfacial Magnetism in Complex Oxide Heterostructures Probed by Neutrons and X-rays
Liu, Yaohua; Ke, Xianglin
2015-09-02
Magnetic complex-oxide heterostructures are of keen interest because a wealth of phenomena at the interface of dissimilar materials can give rise to fundamentally new physics and potentially valuable functionalities. Altered magnetization, novel magnetic coupling and emergent interfacial magnetism at the epitaxial layered-oxide interfaces have all been intensively investigated, which shapes our understanding on how to utilize those materials, particularly for spintronics. Neutron and x-ray based techniques have played a decisive role in characterizing interfacial magnetic structures and clarifying the underlying physics in this rapidly developing field. Here we review some recent experimental results, with an emphasis on those studied viamore » polarized neutron reflectometery and polarized x-ray absorption spectroscopy. We conclude with some perspectives.« less
Interfacial magnetism in complex oxide heterostructures probed by neutrons and x-rays.
Liu, Yaohua; Ke, Xianglin
2015-09-23
Magnetic complex-oxide heterostructures are of keen interest because a wealth of phenomena at the interface of dissimilar materials can give rise to fundamentally new physics and potentially valuable functionalities. Altered magnetization, novel magnetic coupling and emergent interfacial magnetism at the epitaxial layered-oxide interfaces are under intensive investigation, which shapes our understanding on how to utilize those materials, particularly for spintronics. Neutron and x-ray based techniques have played a decisive role in characterizing interfacial magnetic structures and clarifying the underlying physics in this rapidly developing field. Here we review some recent experimental results, with an emphasis on those studied via polarized neutron reflectometery and polarized x-ray absorption spectroscopy. We conclude with some perspectives.
Face liveness detection for face recognition based on cardiac features of skin color image
NASA Astrophysics Data System (ADS)
Suh, Kun Ha; Lee, Eui Chul
2016-07-01
With the growth of biometric technology, spoofing attacks have been emerged a threat to the security of the system. Main spoofing scenarios in the face recognition system include the printing attack, replay attack, and 3D mask attack. To prevent such attacks, techniques that evaluating liveness of the biometric data can be considered as a solution. In this paper, a novel face liveness detection method based on cardiac signal extracted from face is presented. The key point of proposed method is that the cardiac characteristic is detected in live faces but not detected in non-live faces. Experimental results showed that the proposed method can be effective way for determining printing attack or 3D mask attack.
The Impact of Immigration on the Internal Processes and Developmental Tasks of Emerging Adulthood
ERIC Educational Resources Information Center
Walsh, Sophie; Shulman, Shmuel; Feldman, Benny; Maurer, Offer
2005-01-01
This study examines the experience of emerging adult immigrants, a group simultaneously attempting to navigate the developmental period of exploration and experimentation of emerging adulthood, together with the need for re-organization of the self, following immigration. In this study, in-depth interviews were conducted, with 41 emerging adult…
McIntosh, Mark S; Konzelmann, Jason; Smith, Jeffrey; Kalynych, Colleen J; Wears, Robert L; Schneider, Howard; Wylie, Todd; Kaminski, Anne; Matar-Joseph, Madeline
2009-10-01
The objective of this investigation is to use a dental simulation model to compare splinting and bandaging methods for managing tooth avulsions and fractures, as measured by dentist evaluators for quality and time to complete each stabilization procedure. This was a randomized crossover study comparing 3 splinting techniques for managing a traumatically avulsed tooth (periodontal pack, wire, and bondable reinforcement ribbon) and 2 bandage techniques for managing a fractured tooth (calcium hydroxide paste and light-cured composite). After viewing a Just-in-Time training video, a convenience sample of emergency physicians performed the 5 stabilization techniques on dental models containing extracted teeth embedded in clay to simulate a segment of the human dentition. Data collected included time to complete each procedure, the evaluation of dentists about whether the procedure was performed satisfactorily or unsatisfactorily, and the ranking of dentists' and participants' preferred technique. Twenty-five emergency physicians participated in the study: 17 residents, 2 pediatric emergency medicine fellows, and 6 attending physicians. Reported median time, as well as minimum and maximum times to complete each splinting technique for an avulsed tooth, was as follows: periodontal pack 4.4 minutes (2.5 to 6.5 minutes), wire 8.6 minutes (5.8 to 12.9 minutes), and bondable reinforcement ribbon 8.9 minutes (5.6 to 15 minutes). Median time (and minimum and maximum times) to complete each protective bandaging technique for a fractured tooth was calcium hydroxide paste 4.6 minutes (3 to 9.6 minutes) and light-cured composite 7.1 minutes (5.5 to 14.1 minutes). When asked to choose a preferred splinting and bandaging technique according to the performance of the physicians, the dentists chose the bondable reinforcement ribbon 96% (24/25) and the light-cured composite 100% (25/25) of the time. Study participants had no measurable or agreeable preference for a particular splinting or bandaging technique. The results of this study suggest that of the stabilization procedures completed by emergency physicians, dentists preferred the bondable reinforcement ribbon for managing an avulsed tooth and the light-cured composite technique for managing a fractured tooth over the commonly taught and more frequently used procedures in emergency medicine.
Techniques in Experimental Mechanics Applicable to Forest Products Research
Leslie H. Groom; Audrey G. Zink
1994-01-01
The title of this publication-Techniques in Experimental Mechanics Applicable to Forest Products Research-is the theme of this plenary session from the 1994 Annual Meeting of the Forest Products Society (FPS). Although this session focused on experimental techniques that can be of assistance to researchers in the field of forest products, it is hoped that the...
Control of growth of juvenile leaves of Eucalyptus globulus: effects of leaf age.
Metcalfe, J C; Davies, W J; Pereira, J S
1991-12-01
Biophysical variables influencing the expansion of plant cells (yield threshold, cell wall extensibility and turgor) were measured in individual Eucalyptus globulus leaves from the time of emergence until cessation of growth. Leaf water relations variables and growth rates were determined as relative humidity was changed on an hourly basis. Yield threshold and cell wall extensibility were estimated from plots of leaf growth rate versus turgor. Cell wall extensibility was also measured by the Instron technique, and yield threshold was determined experimentally both by stress relaxation in a psychrometer chamber and by incubation in a range of polyethylene glycol solutions. Once emerging leaves reached approximately 5 cm(2) in size, increases in leaf area were rapid throughout the expansive phase and varied little between light and dark periods. Both leaf growth rate and turgor were sensitive to changes in humidity, and in the longer term, both yield threshold and cell wall extensibility changed as the leaf aged. Rapidly expanding leaves had a very low yield threshold and high cell wall extensibility, whereas mature leaves had low cell wall extensibility. Yield threshold increased with leaf age.
Fu, Gang; Shih, Frank Y; Wang, Haimin
2008-11-01
In this paper, we present a novel method to detect Emerging Flux Regions (EFRs) in the solar atmosphere from consecutive full-disk Michelson Doppler Imager (MDI) magnetogram sequences. To our knowledge, this is the first developed technique for automatically detecting EFRs. The method includes several steps. First, the projection distortion on the MDI magnetograms is corrected. Second, the bipolar regions are extracted by applying multiscale circular harmonic filters. Third, the extracted bipolar regions are traced in consecutive MDI frames by Kalman filter as candidate EFRs. Fourth, the properties, such as positive and negative magnetic fluxes and distance between two polarities, are measured in each frame. Finally, a feature vector is constructed for each bipolar region using the measured properties, and the Support Vector Machine (SVM) classifier is applied to distinguish EFRs from other regions. Experimental results show that the detection rate of EFRs is 96.4% and of non-EFRs is 98.0%, and the false alarm rate is 25.7%, based on all the available MDI magnetograms in 2001 and 2002.
NASA Astrophysics Data System (ADS)
Meyer, Ryan M.; Komura, Ichiro; Kim, Kyung-cho; Zetterwall, Tommy; Cumblidge, Stephen E.; Prokofiev, Iouri
2016-02-01
In February 2012, the U.S. Nuclear Regulatory Commission (NRC) executed agreements with VTT Technical Research Centre of Finland, Nuclear Regulatory Authority of Japan (NRA, former JNES), Korea Institute of Nuclear Safety (KINS), Swedish Radiation Safety Authority (SSM), and Swiss Federal Nuclear Safety Inspectorate (ENSI) to establish the Program to Assess the Reliability of Emerging Nondestructive Techniques (PARENT). The goal of PARENT is to investigate the effectiveness of current emerging and perspective novel nondestructive examination procedures and techniques to find flaws in nickel-alloy welds and base materials. This is done by conducting a series of open and blind international round-robin tests on a set of large-bore dissimilar metal welds (LBDMW), small-bore dissimilar metal welds (SBDMW), and bottom-mounted instrumentation (BMI) penetration weld test blocks. The purpose of blind testing is to study the reliability of more established techniques and included only qualified teams and procedures. The purpose of open testing is aimed at a more basic capability assessment of emerging and novel technologies. The range of techniques applied in open testing varied with respect to maturity and performance uncertainty and were applied to a variety of simulated flaws. This paper will include a brief overview of the PARENT blind and open testing techniques and test blocks and present some of the blind testing results.
Emerging MRI Methods in Translational Cardiovascular Research
Vandsburger, Moriel H; Epstein, Frederick H
2011-01-01
Cardiac magnetic resonance imaging (CMR) has become a reference standard modality for imaging of left ventricular (LV) structure and function, and, using late gadolinium enhancement, for imaging myocardial infarction. Emerging CMR techniques enable a more comprehensive examination of the heart, making CMR an excellent tool for use in translational cardiovascular research. Specifically, emerging CMR methods have been developed to measure the extent of myocardial edema, changes in ventricular mechanics, changes in tissue composition as a result of fibrosis, and changes in myocardial perfusion as a function of both disease and infarct healing. New CMR techniques also enable the tracking of labeled cells, molecular imaging of biomarkers of disease, and changes in calcium flux in cardiomyocytes. In addition, MRI can quantify blood flow velocity and wall shear stress in large blood vessels. Almost all of these techniques can be applied in both pre-clinical and clinical settings, enabling both the techniques themselves and the knowledge gained using such techniques in pre-clinical research to be translated from the lab bench to the patient bedside. PMID:21452060
Chi, Albert; Curi, Sebastian; Clayton, Kevin; Luciano, David; Klauber, Kameron; Alexander-Katz, Alfredo; D'hers, Sebastian; Elman, Noel M
2014-08-01
Rapid Reconstitution Packages (RRPs) are portable platforms that integrate microfluidics for rapid reconstitution of lyophilized drugs. Rapid reconstitution of lyophilized drugs using standard vials and syringes is an error-prone process. RRPs were designed using computational fluid dynamics (CFD) techniques to optimize fluidic structures for rapid mixing and integrating physical properties of targeted drugs and diluents. Devices were manufactured using stereo lithography 3D printing for micrometer structural precision and rapid prototyping. Tissue plasminogen activator (tPA) was selected as the initial model drug to test the RRPs as it is unstable in solution. tPA is a thrombolytic drug, stored in lyophilized form, required in emergency settings for which rapid reconstitution is of critical importance. RRP performance and drug stability were evaluated by high-performance liquid chromatography (HPLC) to characterize release kinetics. In addition, enzyme-linked immunosorbent assays (ELISAs) were performed to test for drug activity after the RRPs were exposed to various controlled temperature conditions. Experimental results showed that RRPs provided effective reconstitution of tPA that strongly correlated with CFD results. Simulation and experimental results show that release kinetics can be adjusted by tuning the device structural dimensions and diluent drug physical parameters. The design of RRPs can be tailored for a number of applications by taking into account physical parameters of the active pharmaceutical ingredients (APIs), excipients, and diluents. RRPs are portable platforms that can be utilized for reconstitution of emergency drugs in time-critical therapies.
Embedded DSP-based telehealth radar system for remote in-door fall detection.
Garripoli, Carmine; Mercuri, Marco; Karsmakers, Peter; Jack Soh, Ping; Crupi, Giovanni; Vandenbosch, Guy A E; Pace, Calogero; Leroux, Paul; Schreurs, Dominique
2015-01-01
Telehealth systems and applications are extensively investigated nowadays to enhance the quality-of-care and, in particular, to detect emergency situations and to monitor the well-being of elderly people, allowing them to stay at home independently as long as possible. In this paper, an embedded telehealth system for continuous, automatic, and remote monitoring of real-time fall emergencies is presented and discussed. The system, consisting of a radar sensor and base station, represents a cost-effective and efficient healthcare solution. The implementation of the fall detection data processing technique, based on the least-square support vector machines, through a digital signal processor and the management of the communication between radar sensor and base station are detailed. Experimental tests, for a total of 65 mimicked fall incidents, recorded with 16 human subjects (14 men and two women) that have been monitored for 320 min, have been used to validate the proposed system under real circumstances. The subjects' weight is between 55 and 90 kg with heights between 1.65 and 1.82 m, while their age is between 25 and 39 years. The experimental results have shown a sensitivity to detect the fall events in real time of 100% without reporting false positives. The tests have been performed in an area where the radar's operation was not limited by practical situations, namely, signal power, coverage of the antennas, and presence of obstacles between the subject and the antennas.
Mesenchymal stem cell mechanobiology and emerging experimental platforms
MacQueen, Luke; Sun, Yu; Simmons, Craig A.
2013-01-01
Experimental control over progenitor cell lineage specification can be achieved by modulating properties of the cell's microenvironment. These include physical properties of the cell adhesion substrate, such as rigidity, topography and deformation owing to dynamic mechanical forces. Multipotent mesenchymal stem cells (MSCs) generate contractile forces to sense and remodel their extracellular microenvironments and thereby obtain information that directs broad aspects of MSC function, including lineage specification. Various physical factors are important regulators of MSC function, but improved understanding of MSC mechanobiology requires novel experimental platforms. Engineers are bridging this gap by developing tools to control mechanical factors with improved precision and throughput, thereby enabling biological investigation of mechanics-driven MSC function. In this review, we introduce MSC mechanobiology and review emerging cell culture platforms that enable new insights into mechanobiological control of MSCs. Our main goals are to provide engineers and microtechnology developers with an up-to-date description of MSC mechanobiology that is relevant to the design of experimental platforms and to introduce biologists to these emerging platforms. PMID:23635493
Ptáčková, Renata; Ječmen, Tomáš; Novák, Petr; Hudeček, Jiří; Stiborová, Marie; Šulc, Miroslav
2014-01-01
Protein–protein interaction was investigated using a protein nanoprobe capable of photo-initiated cross-linking in combination with high-resolution and tandem mass spectrometry. This emerging experimental approach introduces photo-analogs of amino acids within a protein sequence during its recombinant expression, preserves native protein structure and is suitable for mapping the contact between two proteins. The contact surface regions involved in the well-characterized interaction between two molecules of human 14-3-3ζ regulatory protein were used as a model. The employed photo-initiated cross-linking techniques extend the number of residues shown to be within interaction distance in the contact surface of the 14-3-3ζ dimer (Gln8–Met78). The results of this study are in agreement with our previously published data from molecular dynamic calculations based on high-resolution chemical cross-linking data and Hydrogen/Deuterium exchange mass spectrometry. The observed contact is also in accord with the 14-3-3ζ X-ray crystal structure (PDB 3dhr). The results of the present work are relevant to the structural biology of transient interaction in the 14-3-3ζ protein, and demonstrate the ability of the chosen methodology (the combination of photo-initiated cross-linking protein nanoprobes and mass spectrometry analysis) to map the protein-protein interface or regions with a flexible structure. PMID:24865487
A study of emergency American football helmet removal techniques.
Swartz, Erik E; Mihalik, Jason P; Decoster, Laura C; Hernandez, Adam E
2012-09-01
The purpose was to compare head kinematics between the Eject Helmet Removal System and manual football helmet removal. This quasi-experimental study was conducted in a controlled laboratory setting. Thirty-two certified athletic trainers (sex, 19 male and 13 female; age, 33 ± 10 years; height, 175 ± 12 cm; mass, 86 ± 20 kg) removed a football helmet from a healthy model under 2 conditions: manual helmet removal and Eject system helmet removal. A 6-camera motion capture system recorded 3-dimensional head position. Our outcome measures consisted of the average angular velocity and acceleration of the head in each movement plane (sagittal, frontal, and transverse), the resultant angular velocity and acceleration, and total motion. Paired-samples t tests compared each variable across the 2 techniques. Manual helmet removal elicited greater average angular velocity in the sagittal and transverse planes and greater resultant angular velocity compared with the Eject system. No differences were observed in average angular acceleration in any single plane of movement; however, the resultant angular acceleration was greater during manual helmet removal. The Eject Helmet Removal System induced greater total head motion. Although the Eject system created more motion at the head, removing a helmet manually resulted in more sudden perturbations as identified by resultant velocity and acceleration of the head. The implications of these findings relate to the care of all cervical spine-injured patients in emergency medical settings, particularly in scenarios where helmet removal is necessary. Copyright © 2012 Elsevier Inc. All rights reserved.
White, Claire E.; Olds, Daniel P.; Hartl, Monika; ...
2017-02-01
The long-term durability of cement-based materials is influenced by the pore structure and associated permeability at the sub-micrometre length scale. With the emergence of new types of sustainable cements in recent decades, there is a pressing need to be able to predict the durability of these new materials, and therefore nondestructive experimental techniques capable of characterizing the evolution of the pore structure are increasingly crucial for investigating cement durability. Here, small-angle neutron scattering is used to analyze the evolution of the pore structure in alkali-activated materials over the initial 24 h of reaction in order to assess the characteristic poremore » sizes that emerge during these short time scales. By using a unified fitting approach for data modeling, information on the pore size and surface roughness is obtained for a variety of precursor chemistries and morphologies (metakaolin- and slag-based pastes). Furthermore, the impact of activator chemistry is elucidatedviathe analysis of pastes synthesized using hydroxide- and silicate-based activators. It is found that the main aspect influencing the size of pores that are accessible using small-angle neutron scattering analysis (approximately 10–500 Å in diameter) is the availability of free silica in the activating solution, which leads to a more refined pore structure with smaller average pore size. Furthermore, as the reaction progresses the gel pores visible using this scattering technique are seen to increase in size.« less
Lee, Seung Min; Sung, Kyung Mi
2017-06-01
The purpose of this study was to examine the effects of a violence coping program (VCP) based on Polk's middle-range theory of resilience on nursing competency, resilience, burnout, and the ability to cope with violence in nurses working in emergency rooms. A quasi-experimental study, with a nonequivalent control group and a pretest-posttest design, was conducted. Participants were 36 nurses who worked in emergency rooms and had experienced violence; 18 nurses from D hospital and 18 nurses from C hospital were assigned to the experimental and control groups, respectively. The experimental group received the VCP twice per week for 8 weeks. Levels of resilience, F=59.41, p<.001, active coping behavior, χ²=33.09, p<.001, and nursing competency, F=59.41 p<.001, increased significantly and levels of passive coping behavior, χ²=22.92, p<.001, and burnout, F=52.74, p<.001, decreased significantly in the experimental group. The results suggest that the VCP could be an effective strategy for reducing burnout and improving resilience, active coping behavior, and nursing competency. Therefore, it would be a useful intervention for improving the quality of nursing care provided in emergency rooms. © 2017 Korean Society of Nursing Science
Arfin-Khan, M A S; Vetter, V M S; Reshi, Z A; Dar, P A; Jentsch, A
2018-05-01
Successful germination and seedling emergence in new environments are crucial first steps in the life history of global plant invaders and thus play a key role in processes of range expansion. We examined the germination and seedling emergence success of three global plant invaders - Lupinus polyphyllus, Senecio inaequidens and Verbascum thapsus - in greenhouses and climate chambers under climate regimes corresponding to seven eco-regions. Seed materials were collected from one non-native population for L. polyphyllus and S. inaequidens, and from 12 populations for V. thapsus (six natives and six non-natives). Experimental climates had significant effects on species responses. No species germinated in the dry (humidity ≤ 50%) and cool (≤ 5 °C) experimental climates. But all species germinated and emerged in two moderately cool (12-19 °C) and in three warm (24-27 °C) experimental climates. In general, V. thapsus showed higher fitness than S. inaequidens and L. polyphyllus. The climate of the seed source region influenced responses of native and non-native populations of V. thapsus. Non-native populations of V. thapsus, originating from the warmer seed source, showed higher performance in warm experimental climates and lower performance in moderately cool experimental climates compared to native populations. Responses of V. thapsus populations were also related to precipitation of the seed source region in moderately dry experimental climates. The warm, semi-arid and humid experimental climates are suitable for the crucial first steps of invasion success for L. polyphyllus, S. inaequidens and V. thapsus. The species adaptation to its source region modified the responses of our studied plants under different experimental climates representing major eco-regions of the world. © 2018 German Society for Plant Sciences and The Royal Botanical Society of the Netherlands.
Hybrid Clustering-GWO-NARX neural network technique in predicting stock price
NASA Astrophysics Data System (ADS)
Das, Debashish; Safa Sadiq, Ali; Mirjalili, Seyedali; Noraziah, A.
2017-09-01
Prediction of stock price is one of the most challenging tasks due to nonlinear nature of the stock data. Though numerous attempts have been made to predict the stock price by applying various techniques, yet the predicted price is not always accurate and even the error rate is high to some extent. Consequently, this paper endeavours to determine an efficient stock prediction strategy by implementing a combinatorial method of Grey Wolf Optimizer (GWO), Clustering and Non Linear Autoregressive Exogenous (NARX) Technique. The study uses stock data from prominent stock market i.e. New York Stock Exchange (NYSE), NASDAQ and emerging stock market i.e. Malaysian Stock Market (Bursa Malaysia), Dhaka Stock Exchange (DSE). It applies K-means clustering algorithm to determine the most promising cluster, then MGWO is used to determine the classification rate and finally the stock price is predicted by applying NARX neural network algorithm. The prediction performance gained through experimentation is compared and assessed to guide the investors in making investment decision. The result through this technique is indeed promising as it has shown almost precise prediction and improved error rate. We have applied the hybrid Clustering-GWO-NARX neural network technique in predicting stock price. We intend to work with the effect of various factors in stock price movement and selection of parameters. We will further investigate the influence of company news either positive or negative in stock price movement. We would be also interested to predict the Stock indices.
Presentation and Impact of Experimental Techniques in Chemistry
ERIC Educational Resources Information Center
Sojka, Zbigniew; Che, Michel
2008-01-01
Laboratory and practical courses, where students become familiar with experimental techniques and learn to interpret data and relate them to appropriate theory, play a vital role in chemical education. In the large panoply of currently available techniques, it is difficult to find a rational and easy way to classify the techniques in relation to…
Code of Federal Regulations, 2012 CFR
2012-10-01
... 44 Emergency Management and Assistance 1 2012-10-01 2011-10-01 true Applicability. 13.4 Section 13.4 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT OF HOMELAND... expenses under The Food Stamp Act of 1977 (section 16 of the Act). (7) A grant for an experimental, pilot...
Allem, Jon-Patrick; Sussman, Steve; Unger, Jennifer B
2017-12-01
Transition-to-adulthood themes, or thoughts and feelings about emerging adulthood, have been measured by the Inventory of the Dimensions of Emerging Adulthood (IDEA) and found to be associated with substance use among emerging adults. It has been suggested, however, that the IDEA is lengthy and may not include the most unique and theoretically relevant constructs of emerging adulthood. The Revised Inventory of the Dimensions of Emerging Adulthood (IDEA-R) was developed as an alternative instrument, but research has yet to determine the relationship between the IDEA-R and substance use among emerging adults (ages 18-25 years). College students completed surveys indicating their identification with transition-to-adulthood themes and substance use. Logistic regression models examined the associations between transition-to-adulthood themes and marijuana use and binge drinking, respectively. Participants who felt emerging adulthood was a time of identity exploration were less likely to report marijuana use, while feelings of experimentation/possibility were positively associated with marijuana use and binge drinking. The IDEA-R may be useful for identifying correlates of substance use among emerging adults. Future research should evaluate the IDEA-R among representative samples of emerging adults to confirm the findings of this study. Health professionals working in substance use prevention may consider targeting the themes of identity exploration and experimentation/possibility in programs intended for emerging adults.
ERIC Educational Resources Information Center
National Highway Traffic Safety Administration (DOT), Washington, DC.
This student study guide is one of three documents prepared for the Emergency Medical Technician (EMT), National Standard Curriculum. The course is designed to develop skills in symptom recognition and in all emergency care procedures and techniques currently considered to be within the responsibilities of an EMT providing emergency medical care…
The Effectiveness of an Emergent Literacy Intervention for Teenage Parents
ERIC Educational Resources Information Center
Scott, Amy; van Bysterveldt, Anne; McNeill, Brigid
2016-01-01
This study determined the effectiveness of an experimental emergent literacy intervention, targeting teenage mothers attending an educational facility. Using a pretest/posttest research design, 27 participants completed a 7-week intervention based in the classroom, targeting a range of emergent literacy skills that they could utilize when reading…
Rasmussen, Peter M.; Smith, Amy F.; Sakadžić, Sava; Boas, David A.; Pries, Axel R.; Secomb, Timothy W.; Østergaard, Leif
2017-01-01
Objective In vivo imaging of the microcirculation and network-oriented modeling have emerged as powerful means of studying microvascular function and understanding its physiological significance. Network-oriented modeling may provide the means of summarizing vast amounts of data produced by high-throughput imaging techniques in terms of key, physiological indices. To estimate such indices with sufficient certainty, however, network-oriented analysis must be robust to the inevitable presence of uncertainty due to measurement errors as well as model errors. Methods We propose the Bayesian probabilistic data analysis framework as a means of integrating experimental measurements and network model simulations into a combined and statistically coherent analysis. The framework naturally handles noisy measurements and provides posterior distributions of model parameters as well as physiological indices associated with uncertainty. Results We applied the analysis framework to experimental data from three rat mesentery networks and one mouse brain cortex network. We inferred distributions for more than five hundred unknown pressure and hematocrit boundary conditions. Model predictions were consistent with previous analyses, and remained robust when measurements were omitted from model calibration. Conclusion Our Bayesian probabilistic approach may be suitable for optimizing data acquisition and for analyzing and reporting large datasets acquired as part of microvascular imaging studies. PMID:27987383
NASA Astrophysics Data System (ADS)
Scalise, Emilio; Wippermann, Stefan; Galli, Giulia; Talapin, Dmitri
Colloidal nanocrystals (NCs) are emerging as cost-effective materials offering exciting prospects for solar energy conversion, light emission and electronic applications. Recent experimental advances demonstrate the synthesis of fully inorganic nanocrystal solids from chemical solution processing. The properties of the NC-solids are heavily determined by the NCs surface and their interactions with the host matrix. However, information on the atomistic structure of such composites is hard to obtain, due to the complexity of the synthesis conditions and the unavailability of robust experimental techniques to probe nanointerfaces at the microscopic level. Here we present a systematic theoretical study of the interaction between InAs and InP NCs with Sn2S64- ligands. Employing a grand canonical ab initio thermodynamic approach we investigate the relative stability of a multitude of configurations possibly realized at the NC-ligand interface. Our study highlights the importance of different structural details and their strong impact on the resulting composite's properties. We show that to obtain a detailed understanding of experimental data it is necessary to take into account complex interfacial structures beyond simplified NC-ligand model interfaces. S. W. acknowledges BMBF NanoMatFutur Grant No. 13N12972. G.G. acknowledges DOE-BES for funding part of this work.
Spike-train spectra and network response functions for non-linear integrate-and-fire neurons.
Richardson, Magnus J E
2008-11-01
Reduced models have long been used as a tool for the analysis of the complex activity taking place in neurons and their coupled networks. Recent advances in experimental and theoretical techniques have further demonstrated the usefulness of this approach. Despite the often gross simplification of the underlying biophysical properties, reduced models can still present significant difficulties in their analysis, with the majority of exact and perturbative results available only for the leaky integrate-and-fire model. Here an elementary numerical scheme is demonstrated which can be used to calculate a number of biologically important properties of the general class of non-linear integrate-and-fire models. Exact results for the first-passage-time density and spike-train spectrum are derived, as well as the linear response properties and emergent states of recurrent networks. Given that the exponential integrate-fire model has recently been shown to agree closely with the experimentally measured response of pyramidal cells, the methodology presented here promises to provide a convenient tool to facilitate the analysis of cortical-network dynamics.
Computational approaches to protein inference in shotgun proteomics
2012-01-01
Shotgun proteomics has recently emerged as a powerful approach to characterizing proteomes in biological samples. Its overall objective is to identify the form and quantity of each protein in a high-throughput manner by coupling liquid chromatography with tandem mass spectrometry. As a consequence of its high throughput nature, shotgun proteomics faces challenges with respect to the analysis and interpretation of experimental data. Among such challenges, the identification of proteins present in a sample has been recognized as an important computational task. This task generally consists of (1) assigning experimental tandem mass spectra to peptides derived from a protein database, and (2) mapping assigned peptides to proteins and quantifying the confidence of identified proteins. Protein identification is fundamentally a statistical inference problem with a number of methods proposed to address its challenges. In this review we categorize current approaches into rule-based, combinatorial optimization and probabilistic inference techniques, and present them using integer programing and Bayesian inference frameworks. We also discuss the main challenges of protein identification and propose potential solutions with the goal of spurring innovative research in this area. PMID:23176300
MALDI, AP/MALDI and ESI techniques for the MS detection of amyloid [beta]-peptides
NASA Astrophysics Data System (ADS)
Grasso, Giuseppe; Mineo, Placido; Rizzarelli, Enrico; Spoto, Giuseppe
2009-04-01
Amyloid [beta]-peptides (A[beta]s) are involved in several neuropathological conditions such as Alzheimer's disease and considerable experimental evidences have emerged indicating that different proteases play a major role in regulating the accumulation of A[beta]s in the brain. Particularly, insulin-degrading enzyme (IDE) has been shown to degrade A[beta]s at different cleavage sites, but the experimental results reported in the literature and obtained by mass spectrometry methods are somehow fragmentary. The detection of A[beta]s is often complicated by solubility issues, oxidation artifacts and spontaneous aggregation/cleavage and, in order to rationalize the different reported results, we analyzed A[beta]s solutions by three different MS approaches: matrix assisted laser desorption ionization-time of flight (MALDI-TOF), atmospheric pressure (AP) MALDI ion trap and electrospray ionization (ESI) ion trap. Differences in the obtained results are discussed and ESI is chosen as the most suitable MS method for A[beta]s detection. Finally, cleavage sites produced by interaction of A[beta]s with IDE are identified, two of which had never been reported in the literature.
Achieving High Throughput for Data Transfer over ATM Networks
NASA Technical Reports Server (NTRS)
Johnson, Marjory J.; Townsend, Jeffrey N.
1996-01-01
File-transfer rates for ftp are often reported to be relatively slow, compared to the raw bandwidth available in emerging gigabit networks. While a major bottleneck is disk I/O, protocol issues impact performance as well. Ftp was developed and optimized for use over the TCP/IP protocol stack of the Internet. However, TCP has been shown to run inefficiently over ATM. In an effort to maximize network throughput, data-transfer protocols can be developed to run over UDP or directly over IP, rather than over TCP. If error-free transmission is required, techniques for achieving reliable transmission can be included as part of the transfer protocol. However, selected image-processing applications can tolerate a low level of errors in images that are transmitted over a network. In this paper we report on experimental work to develop a high-throughput protocol for unreliable data transfer over ATM networks. We attempt to maximize throughput by keeping the communications pipe full, but still keep packet loss under five percent. We use the Bay Area Gigabit Network Testbed as our experimental platform.
Towards sub-nanometer real-space observation of spin and orbital magnetism at the Fe/MgO interface
Thersleff, Thomas; Muto, Shunsuke; Werwiński, Mirosław; Spiegelberg, Jakob; Kvashnin, Yaroslav; Hjӧrvarsson, Björgvin; Eriksson, Olle; Rusz, Ján; Leifer, Klaus
2017-01-01
While the performance of magnetic tunnel junctions based on metal/oxide interfaces is determined by hybridization, charge transfer, and magnetic properties at the interface, there are currently only limited experimental techniques with sufficient spatial resolution to directly observe these effects simultaneously in real-space. In this letter, we demonstrate an experimental method based on Electron Magnetic Circular Dichroism (EMCD) that will allow researchers to simultaneously map magnetic transitions and valency in real-space over interfacial cross-sections with sub-nanometer spatial resolution. We apply this method to an Fe/MgO bilayer system, observing a significant enhancement in the orbital to spin moment ratio that is strongly localized to the interfacial region. Through the use of first-principles calculations, multivariate statistical analysis, and Electron Energy-Loss Spectroscopy (EELS), we explore the extent to which this enhancement can be attributed to emergent magnetism due to structural confinement at the interface. We conclude that this method has the potential to directly visualize spin and orbital moments at buried interfaces in magnetic systems with unprecedented spatial resolution. PMID:28338011
NASA Astrophysics Data System (ADS)
El-Mahallawy, Nahed; Atia, Mostafa R. A.; Khaled, Amany; Shoeib, Madiha
2018-04-01
Research has adopted lately the improvement of solar collectors’ efficiency and durability by coating its surface with special selective coatings. The selectivity of any coat is governed by the ratio between the absorptivity of this coat in the UV range to its emissivity in the IR range (named selectivity). There emerged a need of using simulation software to estimate the effect of different elements and compounds on the optical properties before getting into experimental analysis. Several research has discussed the stability and durability of the coats under high temperature conditions since it was proved that the coat efficiency increases at high temperature; i.e. being more selective. This research has approached the simulation of different metal(M) / metal oxide (MOx) based tandems in order to obtain promising selective properties that can be taken into further experimental investigation. Five metals and six metal oxides were chosen based on previous literature to be simulated using OpenFilters open source software and results were analyzed. Oxides of tungsten, copper and silicon have shown superior selective results through different layering techniques than others.
Towards sub-nanometer real-space observation of spin and orbital magnetism at the Fe/MgO interface
NASA Astrophysics Data System (ADS)
Thersleff, Thomas; Muto, Shunsuke; Werwiński, Mirosław; Spiegelberg, Jakob; Kvashnin, Yaroslav; Hjӧrvarsson, Björgvin; Eriksson, Olle; Rusz, Ján; Leifer, Klaus
2017-03-01
While the performance of magnetic tunnel junctions based on metal/oxide interfaces is determined by hybridization, charge transfer, and magnetic properties at the interface, there are currently only limited experimental techniques with sufficient spatial resolution to directly observe these effects simultaneously in real-space. In this letter, we demonstrate an experimental method based on Electron Magnetic Circular Dichroism (EMCD) that will allow researchers to simultaneously map magnetic transitions and valency in real-space over interfacial cross-sections with sub-nanometer spatial resolution. We apply this method to an Fe/MgO bilayer system, observing a significant enhancement in the orbital to spin moment ratio that is strongly localized to the interfacial region. Through the use of first-principles calculations, multivariate statistical analysis, and Electron Energy-Loss Spectroscopy (EELS), we explore the extent to which this enhancement can be attributed to emergent magnetism due to structural confinement at the interface. We conclude that this method has the potential to directly visualize spin and orbital moments at buried interfaces in magnetic systems with unprecedented spatial resolution.
Music Performance As an Experimental Approach to Hyperscanning Studies
Acquadro, Michaël A. S.; Congedo, Marco; De Riddeer, Dirk
2016-01-01
Humans are fundamentally social and tend to create emergent organizations when interacting with each other; from dyads to families, small groups, large groups, societies, and civilizations. The study of the neuronal substrate of human social behavior is currently gaining momentum in the young field of social neuroscience. Hyperscanning is a neuroimaging technique by which we can study two or more brains simultaneously while participants interact with each other. The aim of this article is to discuss several factors that we deem important in designing hyperscanning experiments. We first review hyperscanning studies performed by means of electroencephalography (EEG) that have been relying on a continuous interaction paradigm. Then, we provide arguments for favoring ecological paradigms, for studying the emotional component of social interactions and for performing longitudinal studies, the last two aspects being largely neglected so far in the hyperscanning literature despite their paramount importance in social sciences. Based on these premises, we argue that music performance is a suitable experimental setting for hyperscanning and that for such studies EEG is an appropriate choice as neuroimaging modality. PMID:27252641
Satellite SAR interferometric techniques applied to emergency mapping
NASA Astrophysics Data System (ADS)
Stefanova Vassileva, Magdalena; Riccardi, Paolo; Lecci, Daniele; Giulio Tonolo, Fabio; Boccardo Boccardo, Piero; Chiesa, Giuliana; Angeluccetti, Irene
2017-04-01
This paper aim to investigate the capabilities of the currently available SAR interferometric algorithms in the field of emergency mapping. Several tests have been performed exploiting the Copernicus Sentinel-1 data using the COTS software ENVI/SARscape 5.3. Emergency Mapping can be defined as "creation of maps, geo-information products and spatial analyses dedicated to providing situational awareness emergency management and immediate crisis information for response by means of extraction of reference (pre-event) and crisis (post-event) geographic information/data from satellite or aerial imagery". The conventional differential SAR interferometric technique (DInSAR) and the two currently available multi-temporal SAR interferometric approaches, i.e. Permanent Scatterer Interferometry (PSI) and Small BAseline Subset (SBAS), have been applied to provide crisis information useful for the emergency management activities. Depending on the considered Emergency Management phase, it may be distinguished between rapid mapping, i.e. fast provision of geospatial data regarding the area affected for the immediate emergency response, and monitoring mapping, i.e. detection of phenomena for risk prevention and mitigation activities. In order to evaluate the potential and limitations of the aforementioned SAR interferometric approaches for the specific rapid and monitoring mapping application, five main factors have been taken into account: crisis information extracted, input data required, processing time and expected accuracy. The results highlight that DInSAR has the capacity to delineate areas affected by large and sudden deformations and fulfills most of the immediate response requirements. The main limiting factor of interferometry is the availability of suitable SAR acquisition immediately after the event (e.g. Sentinel-1 mission characterized by 6-day revisiting time may not always satisfy the immediate emergency request). PSI and SBAS techniques are suitable to produce monitoring maps for risk prevention and mitigation purposes. Nevertheless, multi-temporal techniques require large SAR temporal datasets, i.e. 20 and more images. Being the Sentinel-1 missions operational only since April 2014, multi-mission SAR datasets should be therefore exploited to carry out historical analysis.
Introducing Emergency Preparedness in Childbirth Education Classes
DeWald, Lauren; Fountain, Lily
2006-01-01
In the wake of recent natural and man-made disasters and emergency situations, pregnant women are especially vulnerable. The authors of this column encourage childbirth educators to include disaster preparedness instruction and emergency childbirth techniques in their class content. PMID:17322945
NASA Astrophysics Data System (ADS)
Wehling, T. O.; Black-Schaffer, A. M.; Balatsky, A. V.
2014-01-01
A wide range of materials, like d-wave superconductors, graphene, and topological insulators, share a fundamental similarity: their low-energy fermionic excitations behave as massless Dirac particles rather than fermions obeying the usual Schrodinger Hamiltonian. This emergent behavior of Dirac fermions in condensed matter systems defines the unifying framework for a class of materials we call "Dirac materials''. In order to establish this class of materials, we illustrate how Dirac fermions emerge in multiple entirely different condensed matter systems and we discuss how Dirac fermions have been identified experimentally using electron spectroscopy techniques (angle-resolved photoemission spectroscopy and scanning tunneling spectroscopy). As a consequence of their common low-energy excitations, this diverse set of materials shares a significant number of universal properties in the low-energy (infrared) limit. We review these common properties including nodal points in the excitation spectrum, density of states, specific heat, transport, thermodynamic properties, impurity resonances, and magnetic field responses, as well as discuss many-body interaction effects. We further review how the emergence of Dirac excitations is controlled by specific symmetries of the material, such as time-reversal, gauge, and spin-orbit symmetries, and how by breaking these symmetries a finite Dirac mass is generated. We give examples of how the interaction of Dirac fermions with their distinct real material background leads to rich novel physics with common fingerprints such as the suppression of back scattering and impurity-induced resonant states.
Experimental Procedures for Sensitive and Reproducible In Situ EPR Tooth Dosimetry
Williams, Benjamin B.; Sucheta, Artur; Dong, Ruhong; Sakata, Yasuko; Iwasaki, Akinori; Burke, Gregory; Grinberg, Oleg; Lesniewski, Piotr; Kmiec, Maciej; Swartz, Harold M.
2007-01-01
In vivo electron paramagnetic resonance (EPR) tooth dosimetry provides a means for non-invasive retrospective assessment of personal radiation exposure. While there is a clear need for such capabilities following radiation accidents, the most pressing need for the development of this technology is the heightened likelihood of terrorist events or nuclear conflicts. This technique will enable such measurements to be made at the site of an incident, while the subject is present, to assist emergency personnel as they perform triage for the affected population. At Dartmouth Medical School this development is currently being tested with normal volunteers with irradiated teeth placed in their mouths and with patients who have undergone radiation therapy. Here we describe progress in practical procedures to provide accurate and reproducible in vivo dose estimates. PMID:18591989
Comparison of multiobjective evolutionary algorithms: empirical results.
Zitzler, E; Deb, K; Thiele, L
2000-01-01
In this paper, we provide a systematic comparison of various evolutionary approaches to multiobjective optimization using six carefully chosen test functions. Each test function involves a particular feature that is known to cause difficulty in the evolutionary optimization process, mainly in converging to the Pareto-optimal front (e.g., multimodality and deception). By investigating these different problem features separately, it is possible to predict the kind of problems to which a certain technique is or is not well suited. However, in contrast to what was suspected beforehand, the experimental results indicate a hierarchy of the algorithms under consideration. Furthermore, the emerging effects are evidence that the suggested test functions provide sufficient complexity to compare multiobjective optimizers. Finally, elitism is shown to be an important factor for improving evolutionary multiobjective search.
Tennant, Joanne M.; Haley, Nicholas J.; Denkers, Nathaniel D.; Mathiason, Candace K.; Hoover, Edward A.
2017-01-01
Chronic wasting disease (CWD) is an emergent prion disease affecting cervid species in North America, Canada, South Korea, and recently, Norway. Detection of CWD has been advanced by techniques that rely on amplification of low levels of prion amyloid to a detectable level. However, the increased sensitivity of amplification assays is often compromised by inhibitors and/or activators in complex biologic samples including body fluids, excreta, or the environment. Here, we adapt real-time quaking-induced conversion conditions to specifically detect CWD prions in fecal samples from both experimentally infected deer and naturally infected elk and estimate environmental contamination. The results have application to detection, surveillance and management of CWD, and potentially to other protein-misfolding diseases. PMID:28703697
Decades of Data: Extracting Trends from Microgravity Crystallization History
NASA Technical Reports Server (NTRS)
Judge, R. A.; Snell, E. H.; Kephart, R.; vanderWoerd, M.
2004-01-01
The reduced acceleration environment of an orbiting spacecraft has been proposed as an ideal environment for biological crystal growth as the first sounding rocket flight in 1981 many crystallization experiments have flown with some showing improvement and others not. To further explore macromolecule crystal improvement in microgravity we have accumulated data from published reports and reports submitted by 63 missions including the Space Shuttle program, unmanned satellites, the Russian Space Station MIR and sounding rocket experiments. While it is not at this point in time a comprehensive record of all flight crystallization experimental results, there is however sufficient information for emerging trends to be identified. In this study the effects of the acceleration environment, the techniques of crystallization, sample molecular weight and the response of individual macromolecules to microgravity crystallization will be investigated.
A review of microelectromechanical systems for nanoscale mechanical characterization
NASA Astrophysics Data System (ADS)
Zhu, Yong; Chang, Tzu-Hsuan
2015-09-01
A plethora of nanostructures with outstanding properties have emerged over the past decades. Measuring their mechanical properties and understanding their deformation mechanisms is of paramount importance for many of their device applications. To address this need innovative experimental techniques have been developed, among which a promising one is based upon microelectromechanical systems (MEMS). This article reviews the recent advances in MEMS platforms for the mechanical characterization of one-dimensional (1D) nanostructures over the past decade. A large number of MEMS platforms and related nanomechanics studies are presented to demonstrate the unprecedented capabilities of MEMS for nanoscale mechanical characterization. Focusing on key design considerations, this article aims to provide useful guidelines for developing MEMS platforms. Finally, some of the challenges and future directions in the area of MEMS-enabled nanomechanical characterization are discussed.
Activated persulfate for organic chemical degradation: A review.
Matzek, Laura W; Carter, Kimberly E
2016-05-01
Activated persulfate reactions have widespread application for groundwater and environmental remediation, as many of these reactions involve destruction of environmental contaminants. Within the last five years, knowledge of activated persulfate degradation reactions has grown to include novel means of activating persulfate for enhanced removal of organic species. These current studies cover a long list of organic analytes, including pharmaceuticals, pesticides, halogenated compounds and dyes. An extensive review of recently published experimental parameters and results for the destruction of organic compounds via activated persulfate is presented. Focus is placed on emerging methodologies and manipulation of traditional activation techniques. Knowledge gaps are identified and discussed, as despite the number of publications on this subject, more broad-reaching guidelines are needed for optimizing applications of activated persulfate in water treatment. Copyright © 2016 Elsevier Ltd. All rights reserved.
Proteomics for understanding miRNA biology.
Huang, Tai-Chung; Pinto, Sneha M; Pandey, Akhilesh
2013-02-01
MicroRNAs (miRNAs) are small noncoding RNAs that play important roles in posttranscriptional regulation of gene expression. Mature miRNAs associate with the RNA interference silencing complex to repress mRNA translation and/or degrade mRNA transcripts. Mass spectrometry-based proteomics has enabled identification of several core components of the canonical miRNA processing pathway and their posttranslational modifications which are pivotal in miRNA regulatory mechanisms. The use of quantitative proteomic strategies has also emerged as a key technique for experimental identification of miRNA targets by allowing direct determination of proteins whose levels are altered because of translational suppression. This review focuses on the role of proteomics and labeling strategies to understand miRNA biology. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Basins of attraction in human balance
NASA Astrophysics Data System (ADS)
Smith, Victoria A.; Lockhart, Thurmon E.; Spano, Mark L.
2017-12-01
Falls are a recognized risk factor for unintentional injuries among older adults, accounting for a large proportion of fractures, emergency department visits, and urgent hospitalizations. Human balance and gait research traditionally uses linear or qualitative tests to assess and describe human motion; however, human motion is neither a simple nor a linear process. The objective of this research is to identify and to learn more about what factors affect balance using nonlinear dynamical techniques, such as basin boundaries. Human balance data was collected using dual force plates for leans using only ankle movements as well as for unrestricted leans. Algorithms to describe the basin boundary were created and compared based on how well each method encloses the experimental data points as well as captures the differences between the two leaning conditions.
Expert systems for automated maintenance of a Mars oxygen production system
NASA Technical Reports Server (NTRS)
Ash, Robert L.; Huang, Jen-Kuang; Ho, Ming-Tsang
1989-01-01
A prototype expert system was developed for maintaining autonomous operation of a Mars oxygen production system. Normal operation conditions and failure modes according to certain desired criteria are tested and identified. Several schemes for failure detection and isolation using forward chaining, backward chaining, knowledge-based and rule-based are devised to perform several housekeeping functions. These functions include self-health checkout, an emergency shut down program, fault detection and conventional control activities. An effort was made to derive the dynamic model of the system using Bond-Graph technique in order to develop the model-based failure detection and isolation scheme by estimation method. Finally, computer simulations and experimental results demonstrated the feasibility of the expert system and a preliminary reliability analysis for the oxygen production system is also provided.
Towards memory-aware services and browsing through lifelogging sensing.
Arcega, Lorena; Font, Jaime; Cetina, Carlos
2013-11-05
Every day we receive lots of information through our senses that is lost forever, because it lacked the strength or the repetition needed to generate a lasting memory. Combining the emerging Internet of Things and lifelogging sensors, we believe it is possible to build up a Digital Memory (Dig-Mem) in order to complement the fallible memory of people. This work shows how to realize the Dig-Mem in terms of interactions, affinities, activities, goals and protocols. We also complement this Dig-Mem with memory-aware services and a Dig-Mem browser. Furthermore, we propose a RFID Tag-Sharing technique to speed up the adoption of Dig-Mem. Experimentation reveals an improvement of the user understanding of Dig-Mem as time passes, compared to natural memories where the level of detail decreases over time.
Biddle, D; Macintire, D K
2000-05-01
This article discusses different techniques that can be used in the diagnosis and treatment of obstetrical emergencies. Female reproductive emergencies commonly encountered by small animal practitioners include pyometra, dystocia, cesarean section, mastitis, eclampsia, uterine torsion, and uterine prolapse. A thorough knowledge of normal and abnormal reproductive behavior will aid the emergency veterinarian in successfully managing such cases. Timely diagnosis and treatment of these emergencies will often give a good outcome.
Choi, Insook
2018-01-01
Sonification is an open-ended design task to construct sound informing a listener of data. Understanding application context is critical for shaping design requirements for data translation into sound. Sonification requires methodology to maintain reproducibility when data sources exhibit non-linear properties of self-organization and emergent behavior. This research formalizes interactive sonification in an extensible model to support reproducibility when data exhibits emergent behavior. In the absence of sonification theory, extensibility demonstrates relevant methods across case studies. The interactive sonification framework foregrounds three factors: reproducible system implementation for generating sonification; interactive mechanisms enhancing a listener's multisensory observations; and reproducible data from models that characterize emergent behavior. Supramodal attention research suggests interactive exploration with auditory feedback can generate context for recognizing irregular patterns and transient dynamics. The sonification framework provides circular causality as a signal pathway for modeling a listener interacting with emergent behavior. The extensible sonification model adopts a data acquisition pathway to formalize functional symmetry across three subsystems: Experimental Data Source, Sound Generation, and Guided Exploration. To differentiate time criticality and dimensionality of emerging dynamics, tuning functions are applied between subsystems to maintain scale and symmetry of concurrent processes and temporal dynamics. Tuning functions accommodate sonification design strategies that yield order parameter values to render emerging patterns discoverable as well as rehearsable, to reproduce desired instances for clinical listeners. Case studies are implemented with two computational models, Chua's circuit and Swarm Chemistry social agent simulation, generating data in real-time that exhibits emergent behavior. Heuristic Listening is introduced as an informal model of a listener's clinical attention to data sonification through multisensory interaction in a context of structured inquiry. Three methods are introduced to assess the proposed sonification framework: Listening Scenario classification, data flow Attunement, and Sonification Design Patterns to classify sound control. Case study implementations are assessed against these methods comparing levels of abstraction between experimental data and sound generation. Outcomes demonstrate the framework performance as a reference model for representing experimental implementations, also for identifying common sonification structures having different experimental implementations, identifying common functions implemented in different subsystems, and comparing impact of affordances across multiple implementations of listening scenarios. PMID:29755311
Communications in public health emergency preparedness: a systematic review of the literature.
Savoia, Elena; Lin, Leesa; Viswanath, Kasisomayajula
2013-09-01
During a public health crisis, public health agencies engage in a variety of public communication efforts to inform the population, encourage the adoption of preventive behaviors, and limit the impact of adverse events. Given the importance of communication to the public in public health emergency preparedness, it is critical to examine the extent to which this field of study has received attention from the scientific community. We conducted a systematic literature review to describe current research in the area of communication to the public in public health emergency preparedness, focusing on the association between sociodemographic and behavioral factors and communication as well as preparedness outcomes. Articles were searched in PubMed and Embase and reviewed by 2 independent reviewers. A total of 131 articles were included for final review. Fifty-three percent of the articles were empirical, of which 74% were population-based studies, and 26% used information environment analysis techniques. None had an experimental study design. Population-based studies were rarely supported by theoretical models and mostly relied on a cross-sectional study design. Consistent results were reported on the association between population socioeconomic factors and public health emergency preparedness communication and preparedness outcomes. Our findings show the need for empirical research to determine what type of communication messages can be effective in achieving preparedness outcomes across various population groups. They suggest that a real-time analysis of the information environment is valuable in knowing what is being communicated to the public and could be used for course correction of public health messages during a crisis.
Communications in Public Health Emergency Preparedness: A Systematic Review of the Literature
Savoia, Elena; Viswanath, Kasisomayajula
2013-01-01
During a public health crisis, public health agencies engage in a variety of public communication efforts to inform the population, encourage the adoption of preventive behaviors, and limit the impact of adverse events. Given the importance of communication to the public in public health emergency preparedness, it is critical to examine the extent to which this field of study has received attention from the scientific community. We conducted a systematic literature review to describe current research in the area of communication to the public in public health emergency preparedness, focusing on the association between sociodemographic and behavioral factors and communication as well as preparedness outcomes. Articles were searched in PubMed and Embase and reviewed by 2 independent reviewers. A total of 131 articles were included for final review. Fifty-three percent of the articles were empirical, of which 74% were population-based studies, and 26% used information environment analysis techniques. None had an experimental study design. Population-based studies were rarely supported by theoretical models and mostly relied on a cross-sectional study design. Consistent results were reported on the association between population socioeconomic factors and public health emergency preparedness communication and preparedness outcomes. Our findings show the need for empirical research to determine what type of communication messages can be effective in achieving preparedness outcomes across various population groups. They suggest that a real-time analysis of the information environment is valuable in knowing what is being communicated to the public and could be used for course correction of public health messages during a crisis. PMID:24041193
Experimental scrambling and noise reduction applied to the optical encryption of QR codes.
Barrera, John Fredy; Vélez, Alejandro; Torroba, Roberto
2014-08-25
In this contribution, we implement two techniques to reinforce optical encryption, which we restrict in particular to the QR codes, but could be applied in a general encoding situation. To our knowledge, we present the first experimental-positional optical scrambling merged with an optical encryption procedure. The inclusion of an experimental scrambling technique in an optical encryption protocol, in particular dealing with a QR code "container", adds more protection to the encoding proposal. Additionally, a nonlinear normalization technique is applied to reduce the noise over the recovered images besides increasing the security against attacks. The opto-digital techniques employ an interferometric arrangement and a joint transform correlator encrypting architecture. The experimental results demonstrate the capability of the methods to accomplish the task.
Biological treatment strategies for disc degeneration: potentials and shortcomings
Nerlich, Andreas G.; Boos, Norbert
2006-01-01
Recent advances in molecular biology, cell biology and material sciences have opened a new emerging field of techniques for the treatment of musculoskeletal disorders. These new treatment modalities aim for biological repair of the affected tissues by introducing cell-based tissue replacements, genetic modifications of resident cells or a combination thereof. So far, these techniques have been successfully applied to various tissues such as bone and cartilage. However, application of these treatment modalities to cure intervertebral disc degeneration is in its very early stages and mostly limited to experimental studies in vitro or in animal studies. We will discuss the potential and possible shortcomings of current approaches to biologically cure disc degeneration by gene therapy or tissue engineering. Despite the increasing number of studies examining the therapeutic potential of biological treatment strategies, a practicable solution to routinely cure disc degeneration might not be available in the near future. However, knowledge gained from these attempts might be applied in a foreseeable future to cure the low back pain that often accompanies disc degeneration and therefore be beneficial for the patient. PMID:16983559
Efficient Feature Selection and Classification of Protein Sequence Data in Bioinformatics
Faye, Ibrahima; Samir, Brahim Belhaouari; Md Said, Abas
2014-01-01
Bioinformatics has been an emerging area of research for the last three decades. The ultimate aims of bioinformatics were to store and manage the biological data, and develop and analyze computational tools to enhance their understanding. The size of data accumulated under various sequencing projects is increasing exponentially, which presents difficulties for the experimental methods. To reduce the gap between newly sequenced protein and proteins with known functions, many computational techniques involving classification and clustering algorithms were proposed in the past. The classification of protein sequences into existing superfamilies is helpful in predicting the structure and function of large amount of newly discovered proteins. The existing classification results are unsatisfactory due to a huge size of features obtained through various feature encoding methods. In this work, a statistical metric-based feature selection technique has been proposed in order to reduce the size of the extracted feature vector. The proposed method of protein classification shows significant improvement in terms of performance measure metrics: accuracy, sensitivity, specificity, recall, F-measure, and so forth. PMID:25045727
Speckle reduction in optical coherence tomography images based on wave atoms
Du, Yongzhao; Liu, Gangjun; Feng, Guoying; Chen, Zhongping
2014-01-01
Abstract. Optical coherence tomography (OCT) is an emerging noninvasive imaging technique, which is based on low-coherence interferometry. OCT images suffer from speckle noise, which reduces image contrast. A shrinkage filter based on wave atoms transform is proposed for speckle reduction in OCT images. Wave atoms transform is a new multiscale geometric analysis tool that offers sparser expansion and better representation for images containing oscillatory patterns and textures than other traditional transforms, such as wavelet and curvelet transforms. Cycle spinning-based technology is introduced to avoid visual artifacts, such as Gibbs-like phenomenon, and to develop a translation invariant wave atoms denoising scheme. The speckle suppression degree in the denoised images is controlled by an adjustable parameter that determines the threshold in the wave atoms domain. The experimental results show that the proposed method can effectively remove the speckle noise and improve the OCT image quality. The signal-to-noise ratio, contrast-to-noise ratio, average equivalent number of looks, and cross-correlation (XCOR) values are obtained, and the results are also compared with the wavelet and curvelet thresholding techniques. PMID:24825507
The basolateral amygdala in reward learning and addiction.
Wassum, Kate M; Izquierdo, Alicia
2015-10-01
Sophisticated behavioral paradigms partnered with the emergence of increasingly selective techniques to target the basolateral amygdala (BLA) have resulted in an enhanced understanding of the role of this nucleus in learning and using reward information. Due to the wide variety of behavioral approaches many questions remain on the circumscribed role of BLA in appetitive behavior. In this review, we integrate conclusions of BLA function in reward-related behavior using traditional interference techniques (lesion, pharmacological inactivation) with those using newer methodological approaches in experimental animals that allow in vivo manipulation of cell type-specific populations and neural recordings. Secondly, from a review of appetitive behavioral tasks in rodents and monkeys and recent computational models of reward procurement, we derive evidence for BLA as a neural integrator of reward value, history, and cost parameters. Taken together, BLA codes specific and temporally dynamic outcome representations in a distributed network to orchestrate adaptive responses. We provide evidence that experiences with opiates and psychostimulants alter these outcome representations in BLA, resulting in long-term modified action. Copyright © 2015 Elsevier Ltd. All rights reserved.
Mass Spectrometry Imaging, an Emerging Technology in Neuropsychopharmacology
Shariatgorji, Mohammadreza; Svenningsson, Per; Andrén, Per E
2014-01-01
Mass spectrometry imaging is a powerful tool for directly determining the distribution of proteins, peptides, lipids, neurotransmitters, metabolites and drugs in neural tissue sections in situ. Molecule-specific imaging can be achieved using various ionization techniques that are suited to different applications but which all yield data with high mass accuracies and spatial resolutions. The ability to simultaneously obtain images showing the distributions of chemical species ranging from metal ions to macromolecules makes it possible to explore the chemical organization of a sample and to correlate the results obtained with specific anatomical features. The imaging of biomolecules has provided new insights into multiple neurological diseases, including Parkinson's and Alzheimer's disease. Mass spectrometry imaging can also be used in conjunction with other imaging techniques in order to identify correlations between changes in the distribution of important chemical species and other changes in the properties of the tissue. Here we review the applications of mass spectrometry imaging in neuroscience research and discuss its potential. The results presented demonstrate that mass spectrometry imaging is a useful experimental method with diverse applications in neuroscience. PMID:23966069
Towed-grid system for production and calorimetric study of homogenous quantum turbulence
NASA Astrophysics Data System (ADS)
Ciapurin, Roman; Thompson, Kyle; Ihas, Gary G.
2011-10-01
The decay of quantum turbulence is not fully understood in superfluid helium at milikelvin temperatures where the viscous normal component is absent. Vibrating grid experiments performed periously produced inhomogeneous turbulence, making the results hard to interpret. We have developed experimental methods to produce homogeneous isotropic turbulence by pulling a grid at a variable constant velocity through superfluid 4He. While using calorimetric technique to measure the energy dissipation, the Meissner effect was employed to eliminate all heat sources except from turbulent decay. A controlled divergent magnetic field provides the lift to a hollow cylindrical superconducting actuator to which the grid is attached. Position sensing is performed by measuring the inductance change of a coil when a superconductor, similar to that of the actuator, is moved inside it. This position sensing technique proved to be reliable under varying temperatures and magnetic fields, making it perfect for use in the towed-grid experiment where a rise in temperature emerges from turbulent decay. Additionally, the reproducible dependency of the grid's position on the applied magnetic field enables complete control of the actuator's motion.
Predicting the binding preference of transcription factors to individual DNA k-mers.
Alleyne, Trevis M; Peña-Castillo, Lourdes; Badis, Gwenael; Talukder, Shaheynoor; Berger, Michael F; Gehrke, Andrew R; Philippakis, Anthony A; Bulyk, Martha L; Morris, Quaid D; Hughes, Timothy R
2009-04-15
Recognition of specific DNA sequences is a central mechanism by which transcription factors (TFs) control gene expression. Many TF-binding preferences, however, are unknown or poorly characterized, in part due to the difficulty associated with determining their specificity experimentally, and an incomplete understanding of the mechanisms governing sequence specificity. New techniques that estimate the affinity of TFs to all possible k-mers provide a new opportunity to study DNA-protein interaction mechanisms, and may facilitate inference of binding preferences for members of a given TF family when such information is available for other family members. We employed a new dataset consisting of the relative preferences of mouse homeodomains for all eight-base DNA sequences in order to ask how well we can predict the binding profiles of homeodomains when only their protein sequences are given. We evaluated a panel of standard statistical inference techniques, as well as variations of the protein features considered. Nearest neighbour among functionally important residues emerged among the most effective methods. Our results underscore the complexity of TF-DNA recognition, and suggest a rational approach for future analyses of TF families.
Magnetic resonance spectroscopic imaging at superresolution: Overview and perspectives
NASA Astrophysics Data System (ADS)
Kasten, Jeffrey; Klauser, Antoine; Lazeyras, François; Van De Ville, Dimitri
2016-02-01
The notion of non-invasive, high-resolution spatial mapping of metabolite concentrations has long enticed the medical community. While magnetic resonance spectroscopic imaging (MRSI) is capable of achieving the requisite spatio-spectral localization, it has traditionally been encumbered by significant resolution constraints that have thus far undermined its clinical utility. To surpass these obstacles, research efforts have primarily focused on hardware enhancements or the development of accelerated acquisition strategies to improve the experimental sensitivity per unit time. Concomitantly, a number of innovative reconstruction techniques have emerged as alternatives to the standard inverse discrete Fourier transform (DFT). While perhaps lesser known, these latter methods strive to effect commensurate resolution gains by exploiting known properties of the underlying MRSI signal in concert with advanced image and signal processing techniques. This review article aims to aggregate and provide an overview of the past few decades of so-called "superresolution" MRSI reconstruction methodologies, and to introduce readers to current state-of-the-art approaches. A number of perspectives are then offered as to the future of high-resolution MRSI, with a particular focus on translation into clinical settings.
Information recovery in propagation-based imaging with decoherence effects
NASA Astrophysics Data System (ADS)
Froese, Heinrich; Lötgering, Lars; Wilhein, Thomas
2017-05-01
During the past decades the optical imaging community witnessed a rapid emergence of novel imaging modalities such as coherent diffraction imaging (CDI), propagation-based imaging and ptychography. These methods have been demonstrated to recover complex-valued scalar wave fields from redundant data without the need for refractive or diffractive optical elements. This renders these techniques suitable for imaging experiments with EUV and x-ray radiation, where the use of lenses is complicated by fabrication, photon efficiency and cost. However, decoherence effects can have detrimental effects on the reconstruction quality of the numerical algorithms involved. Here we demonstrate propagation-based optical phase retrieval from multiple near-field intensities with decoherence effects such as partially coherent illumination, detector point spread, binning and position uncertainties of the detector. Methods for overcoming these systematic experimental errors - based on the decomposition of the data into mutually incoherent modes - are proposed and numerically tested. We believe that the results presented here open up novel algorithmic methods to accelerate detector readout rates and enable subpixel resolution in propagation-based phase retrieval. Further the techniques are straightforward to be extended to methods such as CDI, ptychography and holography.
Mass spectrometry imaging, an emerging technology in neuropsychopharmacology.
Shariatgorji, Mohammadreza; Svenningsson, Per; Andrén, Per E
2014-01-01
Mass spectrometry imaging is a powerful tool for directly determining the distribution of proteins, peptides, lipids, neurotransmitters, metabolites and drugs in neural tissue sections in situ. Molecule-specific imaging can be achieved using various ionization techniques that are suited to different applications but which all yield data with high mass accuracies and spatial resolutions. The ability to simultaneously obtain images showing the distributions of chemical species ranging from metal ions to macromolecules makes it possible to explore the chemical organization of a sample and to correlate the results obtained with specific anatomical features. The imaging of biomolecules has provided new insights into multiple neurological diseases, including Parkinson's and Alzheimer's disease. Mass spectrometry imaging can also be used in conjunction with other imaging techniques in order to identify correlations between changes in the distribution of important chemical species and other changes in the properties of the tissue. Here we review the applications of mass spectrometry imaging in neuroscience research and discuss its potential. The results presented demonstrate that mass spectrometry imaging is a useful experimental method with diverse applications in neuroscience.
78 FR 20330 - Agency Information Collection Activities: Proposed Collection; Comment Request
Federal Register 2010, 2011, 2012, 2013, 2014
2013-04-04
... instruction of emergency preparedness officials and other persons in the organization, operation, and techniques of emergency preparedness, and to conduct or operate schools or classes. The Administrator... DEPARTMENT OF HOMELAND SECURITY Federal Emergency Management Agency [Docket ID: FEMA-2013-0009...
Prediction of physical protein protein interactions
NASA Astrophysics Data System (ADS)
Szilágyi, András; Grimm, Vera; Arakaki, Adrián K.; Skolnick, Jeffrey
2005-06-01
Many essential cellular processes such as signal transduction, transport, cellular motion and most regulatory mechanisms are mediated by protein-protein interactions. In recent years, new experimental techniques have been developed to discover the protein-protein interaction networks of several organisms. However, the accuracy and coverage of these techniques have proven to be limited, and computational approaches remain essential both to assist in the design and validation of experimental studies and for the prediction of interaction partners and detailed structures of protein complexes. Here, we provide a critical overview of existing structure-independent and structure-based computational methods. Although these techniques have significantly advanced in the past few years, we find that most of them are still in their infancy. We also provide an overview of experimental techniques for the detection of protein-protein interactions. Although the developments are promising, false positive and false negative results are common, and reliable detection is possible only by taking a consensus of different experimental approaches. The shortcomings of experimental techniques affect both the further development and the fair evaluation of computational prediction methods. For an adequate comparative evaluation of prediction and high-throughput experimental methods, an appropriately large benchmark set of biophysically characterized protein complexes would be needed, but is sorely lacking.
Cheluvappa, Rajkumar; Scowen, Paul; Eri, Rajaraman
2017-08-01
Animals have been used in research and teaching for a long time. However, clear ethical guidelines and pertinent legislation were instated only in the past few decades, even in developed countries with Judeo-Christian ethical roots. We compactly cover the basics of animal research ethics, ethical reviewing and compliance guidelines for animal experimentation across the developed world, "our" fundamentals of institutional animal research ethics teaching, and emerging alternatives to animal research. This treatise was meticulously constructed for scientists interested/involved in animal research. Herein, we discuss key animal ethics principles - Replacement/Reduction/Refinement. Despite similar undergirding principles across developed countries, ethical reviewing and compliance guidelines for animal experimentation vary. The chronology and evolution of mandatory institutional ethical reviewing of animal experimentation (in its pioneering nations) are summarised. This is followed by a concise rendition of the fundamentals of teaching animal research ethics in institutions. With the advent of newer methodologies in human cell-culturing, novel/emerging methods aim to minimise, if not avoid the usage of animals in experimentation. Relevant to this, we discuss key extant/emerging alternatives to animal use in research; including organs on chips, human-derived three-dimensional tissue models, human blood derivates, microdosing, and computer modelling of various hues. © 2017 The Authors. Pharmacology Research & Perspectives published by John Wiley & Sons Ltd, British Pharmacological Society and American Society for Pharmacology and Experimental Therapeutics.
ERIC Educational Resources Information Center
Ellis, Kellie Coldiron
2012-01-01
The acquisition of emergent literacy skills has become a prominent focus of early childhood education programs in recent years as research has demonstrated the significance of emergent literacy ability in the process of learning to read. The effectiveness of use of varied instructional techniques targeting the emergent literacy domains of…
Thermal neutron detector based on COTS CMOS imagers and a conversion layer containing Gadolinium
NASA Astrophysics Data System (ADS)
Pérez, Martín; Blostein, Juan Jerónimo; Bessia, Fabricio Alcalde; Tartaglione, Aureliano; Sidelnik, Iván; Haro, Miguel Sofo; Suárez, Sergio; Gimenez, Melisa Lucía; Berisso, Mariano Gómez; Lipovetzky, Jose
2018-06-01
In this work we will introduce a novel low cost position sensitive thermal neutron detection technique, based on a Commercial Off The Shelf CMOS image sensor covered with a Gadolinium containing conversion layer. The feasibility of the neutron detection technique implemented in this work has been experimentally demonstrated. A thermal neutron detection efficiency of 11.3% has been experimentally obtained with a conversion layer of 11.6 μm. It was experimentally verified that the thermal neutron detection efficiency of this technique is independent on the intensity of the incident thermal neutron flux, which was confirmed for conversion layers of different thicknesses. Based on the experimental results, a spatial resolution better than 25 μm is expected. This spatial resolution makes the proposed technique specially useful for neutron beam characterization, neutron beam dosimetry, high resolution neutron imaging, and several neutron scattering techniques.
NDE Techniques Used in PARENT Open Round Robin Testing
DOE Office of Scientific and Technical Information (OSTI.GOV)
Meyer, Ryan M.
2014-11-05
This is a draft technical letter report for NRC client describing the NDE techniques used in the open testing portion of the Program to Assess the Reliability of Emerging Nondestructive Techniques (PARENT).
NASA Technical Reports Server (NTRS)
Vary, A.; Klima, S. J.
1985-01-01
An overview of nondestructive evaluation (NDE) is presented to indicate the availability and application potentials of techniques for quantitative characterization of the mechanical properties of structural materials. The purpose is to review NDE techniques that go beyond the usual emphasis on flaw detection and characterization. Discussed are current and emerging NDE techniques that can verify and monitor entrinsic properties (e.g., tensile, shear, and yield strengths; fracture toughness, hardness, ductility; elastic moduli) and underlying microstructural and morphological factors. Most of the techniques described are, at present, neither widely applied nor widely accepted in commerce and industry because they are still emerging from the laboratory. The limitations of the techniques may be overcome by advances in applications research and instrumentation technology and perhaps by accommodations for their use in the design of structural parts.
Patel, Trushar R; Chojnowski, Grzegorz; Astha; Koul, Amit; McKenna, Sean A; Bujnicki, Janusz M
2017-04-15
The diverse functional cellular roles played by ribonucleic acids (RNA) have emphasized the need to develop rapid and accurate methodologies to elucidate the relationship between the structure and function of RNA. Structural biology tools such as X-ray crystallography and Nuclear Magnetic Resonance are highly useful methods to obtain atomic-level resolution models of macromolecules. However, both methods have sample, time, and technical limitations that prevent their application to a number of macromolecules of interest. An emerging alternative to high-resolution structural techniques is to employ a hybrid approach that combines low-resolution shape information about macromolecules and their complexes from experimental hydrodynamic (e.g. analytical ultracentrifugation) and solution scattering measurements (e.g., solution X-ray or neutron scattering), with computational modeling to obtain atomic-level models. While promising, scattering methods rely on aggregation-free, monodispersed preparations and therefore the careful development of a quality control pipeline is fundamental to an unbiased and reliable structural determination. This review article describes hydrodynamic techniques that are highly valuable for homogeneity studies, scattering techniques useful to study the low-resolution shape, and strategies for computational modeling to obtain high-resolution 3D structural models of RNAs, proteins, and RNA-protein complexes. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.
From gristle to chondrocyte transplantation: treatment of cartilage injuries.
Lindahl, Anders
2015-10-19
This review addresses the progress in cartilage repair technology over the decades with an emphasis on cartilage regeneration with cell therapy. The most abundant cartilage is the hyaline cartilage that covers the surface of our joints and, due to avascularity, this tissue is unable to repair itself. The cartilage degeneration seen in osteoarthritis causes patient suffering and is a huge burden to society. The surgical approach to cartilage repair was non-existing until the 1950s when new surgical techniques emerged. The use of cultured cells for cell therapy started as experimental studies in the 1970s that developed over the years to a clinical application in 1994 with the introduction of the autologous chondrocyte transplantation technique (ACT). The technology is now spread worldwide and has been further refined by combining arthroscopic techniques with cells cultured on matrix (MACI technology). The non-regenerating hypothesis of cartilage has been revisited and we are now able to demonstrate cell divisions and presence of stem-cell niches in the joint. Furthermore, cartilage derived from human embryonic stem cells and induced pluripotent stem cells could be the base for new broader cell treatments for cartilage injuries and the future technology base for prevention and cure of osteoarthritis. © 2015 The Author(s).
Influence of vapor deposition on structural and charge transport properties of ethylbenzene films
Antony, Lucas W.; Jackson, Nicholas E.; Lyubimov, Ivan; ...
2017-04-14
Organic glass films formed by physical vapor deposition exhibit enhanced stability relative to those formed by conventional liquid cooling and aging techniques. Recently, experimental and computational evidence has emerged indicating that the average molecular orientation can be tuned by controlling the substrate temperature at which these “stable glasses” are grown. In this work, we present a comprehensive all-atom simulation study of ethylbenzene, a canonical stable-glass former, using a computational film formation procedure that closely mimics the vapor deposition process. Atomistic studies of experimentally formed vapor-deposited glasses have not been performed before, and this study therefore begins by verifying that themore » model and method utilized here reproduces key structural features observed experimentally. Having established agreement between several simulated and experimental macroscopic observables, simulations are used to examine the substrate temperature dependence of molecular orientation. The results indicate that ethylbenzene glasses are anisotropic, depending upon substrate temperature, and that this dependence can be understood from the orientation present at the surface of the equilibrium liquid. By treating ethylbenzene as a simple model for molecular semiconducting materials, a quantum-chemical analysis is then used to show that the vapor-deposited glasses exhibit decreased energetic disorder and increased magnitude of the mean-squared transfer integral relative to isotropic, liquid-cooled films, an effect that is attributed to the anisotropic ordering of the molecular film. Finally, these results suggest a novel structure–function simulation strategy capable of tuning the electronic properties of organic semiconducting glasses prior to experimental deposition, which could have considerable potential for organic electronic materials design.« less
Influence of vapor deposition on structural and charge transport properties of ethylbenzene films
DOE Office of Scientific and Technical Information (OSTI.GOV)
Antony, Lucas W.; Jackson, Nicholas E.; Lyubimov, Ivan
Organic glass films formed by physical vapor deposition exhibit enhanced stability relative to those formed by conventional liquid cooling and aging techniques. Recently, experimental and computational evidence has emerged indicating that the average molecular orientation can be tuned by controlling the substrate temperature at which these “stable glasses” are grown. In this work, we present a comprehensive all-atom simulation study of ethylbenzene, a canonical stable-glass former, using a computational film formation procedure that closely mimics the vapor deposition process. Atomistic studies of experimentally formed vapor-deposited glasses have not been performed before, and this study therefore begins by verifying that themore » model and method utilized here reproduces key structural features observed experimentally. Having established agreement between several simulated and experimental macroscopic observables, simulations are used to examine the substrate temperature dependence of molecular orientation. The results indicate that ethylbenzene glasses are anisotropic, depending upon substrate temperature, and that this dependence can be understood from the orientation present at the surface of the equilibrium liquid. By treating ethylbenzene as a simple model for molecular semiconducting materials, a quantum-chemical analysis is then used to show that the vapor-deposited glasses exhibit decreased energetic disorder and increased magnitude of the mean-squared transfer integral relative to isotropic, liquid-cooled films, an effect that is attributed to the anisotropic ordering of the molecular film. Finally, these results suggest a novel structure–function simulation strategy capable of tuning the electronic properties of organic semiconducting glasses prior to experimental deposition, which could have considerable potential for organic electronic materials design.« less
Influence of Vapor Deposition on Structural and Charge Transport Properties of Ethylbenzene Films
2017-01-01
Organic glass films formed by physical vapor deposition exhibit enhanced stability relative to those formed by conventional liquid cooling and aging techniques. Recently, experimental and computational evidence has emerged indicating that the average molecular orientation can be tuned by controlling the substrate temperature at which these “stable glasses” are grown. In this work, we present a comprehensive all-atom simulation study of ethylbenzene, a canonical stable-glass former, using a computational film formation procedure that closely mimics the vapor deposition process. Atomistic studies of experimentally formed vapor-deposited glasses have not been performed before, and this study therefore begins by verifying that the model and method utilized here reproduces key structural features observed experimentally. Having established agreement between several simulated and experimental macroscopic observables, simulations are used to examine the substrate temperature dependence of molecular orientation. The results indicate that ethylbenzene glasses are anisotropic, depending upon substrate temperature, and that this dependence can be understood from the orientation present at the surface of the equilibrium liquid. By treating ethylbenzene as a simple model for molecular semiconducting materials, a quantum-chemical analysis is then used to show that the vapor-deposited glasses exhibit decreased energetic disorder and increased magnitude of the mean-squared transfer integral relative to isotropic, liquid-cooled films, an effect that is attributed to the anisotropic ordering of the molecular film. These results suggest a novel structure–function simulation strategy capable of tuning the electronic properties of organic semiconducting glasses prior to experimental deposition, which could have considerable potential for organic electronic materials design. PMID:28573203
Experimental and analytical determination of stability parameters for a balloon tethered in a wind
NASA Technical Reports Server (NTRS)
Redd, L. T.; Bennett, R. M.; Bland, S. R.
1973-01-01
Experimental and analytical techniques for determining stability parameters for a balloon tethered in a steady wind are described. These techniques are applied to a particular 7.64-meter-long balloon, and the results are presented. The stability parameters of interest appear as coefficients in linearized stability equations and are derived from the various forces and moments acting on the balloon. In several cases the results from the experimental and analytical techniques are compared and suggestions are given as to which techniques are the most practical means of determining values for the stability parameters.
Psychometric Profile of an Experimental Emergent Literacy Screener for Preschoolers
ERIC Educational Resources Information Center
Bailet, Laura L.; Zettler-Greeley, Cynthia; Lewis, Kandia
2018-01-01
Home literacy activities influence children's emergent literacy progress and readiness for reading instruction. To help parents fulfill this opportunity, we developed a new Emergent Literacy Screener (ELS) and conducted 2 studies of its psychometric properties with independent prekindergarten samples. For Study 1 (n = 812, M[subscript age] = 54.4…
ERIC Educational Resources Information Center
Soltero-González, Lucinda; Sparrow, Wendy; Butvilofsky, Sandra; Escamilla, Kathy; Hopewell, Susan
2016-01-01
This longitudinal study examined whether the implementation of a Spanish-English paired literacy approach provides an academic advantage to emerging bilingual students over a sequential literacy approach. The study employed a quasi-experimental design. It compared the biliteracy outcomes of third-grade emerging bilingual learners participating in…
Cancer in light of experimental evolution.
Sprouffske, Kathleen; Merlo, Lauren M F; Gerrish, Philip J; Maley, Carlo C; Sniegowski, Paul D
2012-09-11
Cancer initiation, progression, and the emergence of therapeutic resistance are evolutionary phenomena of clonal somatic cell populations. Studies in microbial experimental evolution and the theoretical work inspired by such studies are yielding deep insights into the evolutionary dynamics of clonal populations, yet there has been little explicit consideration of the relevance of this rapidly growing field to cancer biology. Here, we examine how the understanding of mutation, selection, and spatial structure in clonal populations that is emerging from experimental evolution may be applicable to cancer. Along the way, we discuss some significant ways in which cancer differs from the model systems used in experimental evolution. Despite these differences, we argue that enhanced prediction and control of cancer may be possible using ideas developed in the context of experimental evolution, and we point out some prospects for future research at the interface between these traditionally separate areas. Copyright © 2012 Elsevier Ltd. All rights reserved.
Cancer in Light of Experimental Evolution
Sprouffske, Kathleen; Merlo, Lauren M.F.; Gerrish, Philip J.; Maley, Carlo C.; Sniegowski, Paul D.
2012-01-01
Cancer initiation, progression, and the emergence of therapeutic resistance are evolutionary phenomena of clonal somatic cell populations. Studies in microbial experimental evolution and the theoretical work inspired by such studies are yielding deep insights into the evolutionary dynamics of clonal populations, yet there has been little explicit consideration of the relevance of this rapidly growing field to cancer biology. Here, we examine how the understanding of mutation, selection, and spatial structure in clonal populations that is emerging from experimental evolution may be applicable to cancer. Along the way, we discuss some significant ways in which cancer differs from the model systems used in experimental evolution. Despite these differences, we argue that enhanced prediction and control of cancer may be possible using ideas developed in the context of experimental evolution, and we point out some prospects for future research at the interface between these traditionally separate areas. PMID:22975007
In-situ identification of anti-personnel mines using acoustic resonant spectroscopy
DOE Office of Scientific and Technical Information (OSTI.GOV)
Perry, R L; Roberts, R S
1999-02-01
A new technique for identifying buried Anti-Personnel Mines is described, and a set of preliminary experiments designed to assess the feasibility of this technique is presented. Analysis of the experimental results indicates that the technique has potential, but additional work is required to bring the technique to fruition. In addition to the experimental results presented here, a technique used to characterize the sensor employed in the experiments is detailed.
Systematic Analysis of Theses in the Field of Emergency Medicine in Turkey.
Cevik, Erdem; Karakus Yilmaz, Banu; Acar, Yahya Ayhan; Dokur, Mehmet
2015-03-01
The aim of this study is to systematically evaluate the theses in the field of emergency medicine in Turkey and to determine whether they were published as a scientific paper. This is a retrospective observational study. Theses in the field of emergency medicine between 1998 and 2013 were browsed from the internet database of National Thesis Center (Council of Higher Education). Study type, both if it was in the field of emergency, or if it was published and the journal's scope of published studies were assessed and recorded in the study chart. 579 theses were included in the study. 27.1% of them were published and 14.9% of them were published in SCI/SCI-E journals. Advisors of theses were emergency medicine specialists in 67.6% of theses and 493 (85.1%) of them were in the field of emergency medicine. 77.4% of theses were observational and 20.9% were experimental study. Most of the experimental studies (72.7%, n=88) were animal studies. It was concluded that very few theses in the field of emergency medicine were published in journals that were indexed in SCI/SCI-E.
Real-time analysis application for identifying bursty local areas related to emergency topics.
Sakai, Tatsuhiro; Tamura, Keiichi
2015-01-01
Since social media started getting more attention from users on the Internet, social media has been one of the most important information source in the world. Especially, with the increasing popularity of social media, data posted on social media sites are rapidly becoming collective intelligence, which is a term used to refer to new media that is displacing traditional media. In this paper, we focus on geotagged tweets on the Twitter site. These geotagged tweets are referred to as georeferenced documents because they include not only a short text message, but also the documents' posting time and location. Many researchers have been tackling the development of new data mining techniques for georeferenced documents to identify and analyze emergency topics, such as natural disasters, weather, diseases, and other incidents. In particular, the utilization of geotagged tweets to identify and analyze natural disasters has received much attention from administrative agencies recently because some case studies have achieved compelling results. In this paper, we propose a novel real-time analysis application for identifying bursty local areas related to emergency topics. The aim of our new application is to provide new platforms that can identify and analyze the localities of emergency topics. The proposed application is composed of three core computational intelligence techniques: the Naive Bayes classifier technique, the spatiotemporal clustering technique, and the burst detection technique. Moreover, we have implemented two types of application interface: a Web application interface and an android application interface. To evaluate the proposed application, we have implemented a real-time weather observation system embedded the proposed application. we used actual crawling geotagged tweets posted on the Twitter site. The weather observation system successfully detected bursty local areas related to observed emergency weather topics.
Experimental Validation Techniques for the Heleeos Off-Axis Laser Propagation Model
2010-03-01
EXPERIMENTAL VALIDATION TECHNIQUES FOR THE HELEEOS OFF-AXIS LASER PROPAGATION MODEL THESIS John Haiducek, 1st Lt, USAF AFIT/GAP/ENP/10-M07 DEPARTMENT...Department of Defense, or the United States Government. AFIT/GAP/ENP/10-M07 EXPERIMENTAL VALIDATION TECHNIQUES FOR THE HELEEOS OFF-AXIS LASER ...BS, Physics 1st Lt, USAF March 2010 APPROVED FOR PUBLIC RELEASE; DISTRIBUTION UNLIMITED. AFIT/GAP/ENP/10-M07 Abstract The High Energy Laser End-to-End
Nuclear fission: a review of experimental advances and phenomenology
NASA Astrophysics Data System (ADS)
Andreyev, A. N.; Nishio, K.; Schmidt, K.-H.
2018-01-01
In the last two decades, through technological, experimental and theoretical advances, the situation in experimental fission studies has changed dramatically. With the use of advanced production and detection techniques both much more detailed and precise information can now be obtained for the traditional regions of fission research and, crucially, new regions of nuclei have become routinely accessible for fission studies. This work first of all reviews the recent developments in experimental fission techniques, in particular the resurgence of transfer-induced fission reactions with light and heavy ions, the emerging use of inverse-kinematic approaches, both at Coulomb and relativistic energies, and of fission studies with radioactive beams. The emphasis on the fission-fragment mass and charge distributions will be made in this work, though some of the other fission observables, such as prompt neutron and γ-ray emission will also be reviewed. A particular attention will be given to the low-energy fission in the so far scarcely explored nuclei in the very neutron-deficient lead region. They recently became the focus for several complementary experimental studies, such as β-delayed fission with radioactive beams at ISOLDE(CERN), Coulex-induced fission of relativistic secondary beams at FRS(GSI), and several prompt fusion–fission studies. The synergy of these approaches allows a unique insight in the new region of asymmetric fission around {\\hspace{0pt}}180 Hg, recently discovered at ISOLDE. Recent extensive theoretical efforts in this region will also be outlined. The unprecedented high-quality data for fission fragments, completely identified in Z and A, by means of reactions in inverse kinematics at FRS(GSI) and VAMOS(GANIL) will be also reviewed. These experiments explored an extended range of mercury-to-californium elements, spanning from the neutron-deficient to neutron-rich nuclides, and covering both asymmetric, symmetric and transitional fission regions. Some aspects of heavy-ion induced fusion–fission and quasifission reactions will be also discussed, which reveal their dynamical features, such as the fission time scale. The crucial role of the multi-chance fission, probed by means of multinucleon-transfer induced fission reactions, will be highlighted. The review will conclude with the discussion of the new experimental fission facilities which are presently being brought into operation, along with promising ‘next-generation’ fission approaches, which might become available within the next decade.
NASA Astrophysics Data System (ADS)
Grogan, Joseph M.
There are many scientifically interesting and technologically relevant nanoscale phenomena that take place in liquid media. Examples include aggregation and assembly of nanoparticles; colloidal crystal formation; liquid phase growth of structures such as nanowires; electrochemical deposition and etching for fabrication processes and battery applications; interfacial phenomena; boiling and cavitation; and biological interactions. Understanding of these fields would benefit greatly from real-time, in situ transmission electron microscope (TEM) imaging with nanoscale resolution. Most liquids cannot be imaged by traditional TEM due to evaporation in the high vacuum environment and the requirement that samples be very thin. Liquid-cell in situ TEM has emerged as an exciting new experimental technique that hermetically seals a thin slice of liquid between two electron transparent membranes to enable TEM imaging of liquid-based processes. This work presents details of the fabrication of a custom-made liquid-cell in situ TEM device, dubbed the nanoaquarium. The nanoaquarium's highlights include an exceptionally thin sample cross section (10s to 100s of nm); wafer scale processing that enables high-yield mass production; robust hermetic sealing that provides leak-free operation without use of glue, epoxy, or any polymers; compatibility with lab-on-chip technology; and on-chip integrated electrodes for sensing and actuation. The fabrication process is described, with an emphasis on direct wafer bonding. Experimental results involving direct observation of colloid aggregation using an aqueous solution of gold nanoparticles are presented. Quantitative analysis of the growth process agrees with prior results and theory, indicating that the experimental technique does not radically alter the observed phenomenon. For the first time, in situ observations of nanoparticles at a contact line and in an evaporating thin film of liquid are reported, with applications for techniques such as dip-coating and drop-casting, commonly used for depositing nanoparticles on a surface via convective-capillary assembly. Theoretical analysis suggests that the observed particle motion and aggregation are caused by gradients in surface tension and disjoining pressure in the thin liquid film.
Emerging nondestructive inspection methods for aging aircraft
DOE Office of Scientific and Technical Information (OSTI.GOV)
Beattie, A; Dahlke, L; Gieske, J
This report identifies and describes emerging nondestructive inspection (NDI) methods that can potentially be used to inspect commercial transport and commuter aircraft for structural damage. The nine categories of emerging NDI techniques are: acoustic emission, x-ray computed tomography, backscatter radiation, reverse geometry x-ray, advanced electromagnetics, including magnetooptic imaging and advanced eddy current techniques, coherent optics, advanced ultrasonics, advanced visual, and infrared thermography. The physical principles, generalized performance characteristics, and typical applications associated with each method are described. In addition, aircraft inspection applications are discussed along with the associated technical considerations. Finally, the status of each technique is presented, with amore » discussion on when it may be available for use in actual aircraft maintenance programs. It should be noted that this is a companion document to DOT/FAA/CT-91/5, Current Nondestructive Inspection Methods for Aging Aircraft.« less
Light-Front Hamiltonian Approach to the Bound-State Problem in Quantum Electrodynamics
NASA Astrophysics Data System (ADS)
Jones, Billy D.
1997-10-01
Why is the study of the Lamb shift in hydrogen, which at the level of detail found in this paper was largely completed by Bethe in 1947, of any real interest today? While completing such a calculation using new techniques may be very interesting for formal and academic reasons, our primary motivation is to lay groundwork for precision bound-state calculations in QCD. The Lamb shift provides an excellent pedagogical tool for illustrating light-front Hamiltonian techniques, which are not widely known; but more importantly it presents three of the central dynamical and computational problems that we must face to make these techniques useful for solving QCD: How does a constituent picture emerge in a gauge field theory? How do bound-state energy scales emerge non-perturbatively? How does rotational symmetry emerge in a non-perturbative light-front calculation?
Emerging Heterogeneities in Italian Customs and Comparison with Nearby Countries
Agliari, Elena; Barra, Adriano; Galluzzi, Andrea; Javarone, Marco Alberto; Pizzoferrato, Andrea; Tantari, Daniele
2015-01-01
In this work we apply techniques and modus operandi typical of Statistical Mechanics to a large dataset about key social quantifiers and compare the resulting behaviors of five European nations, namely France, Germany, Italy, Spain and Switzerland. The social quantifiers considered are i. the evolution of the number of autochthonous marriages (i.e., between two natives) within a given territorial district and ii. the evolution of the number of mixed marriages (i.e., between a native and an immigrant) within a given territorial district. Our investigations are twofold. From a theoretical perspective, we develop novel techniques, complementary to classical methods (e.g., historical series and logistic regression), in order to detect possible collective features underlying the empirical behaviors; from an experimental perspective, we evidence a clear outline for the evolution of the social quantifiers considered. The comparison between experimental results and theoretical predictions is excellent and allows speculating that France, Italy and Spain display a certain degree of internal heterogeneity, that is not found in Germany and Switzerland; such heterogeneity, quite mild in France and in Spain, is not negligible in Italy and highlights quantitative differences in the habits of Northern and Southern regions. These findings may suggest the persistence of two culturally distinct communities, long-term lasting heritages of different and well-established customs. Also, we find qualitative differences between the evolution of autochthonous and of mixed marriages: for the former imitation in decisional mechanisms seems to play a key role (and this results in a square root relation between the number of autochthonous marriages versus the percentage of possible couples inside that country), while for the latter the emerging behavior can be recovered (in most cases) with elementary models with no interactions, suggesting weak imitation patterns between natives and migrants (and this translates in a linear growth for the number of mixed marriages versus the percentage of possible mixed couples in the country). However, the case of mixed marriages displays a more complex phenomenology, where further details (e.g., the provenance and the status of migrants, linguistic barriers, etc.) should also be accounted for. PMID:26713615
Emerging Heterogeneities in Italian Customs and Comparison with Nearby Countries.
Agliari, Elena; Barra, Adriano; Galluzzi, Andrea; Javarone, Marco Alberto; Pizzoferrato, Andrea; Tantari, Daniele
2015-01-01
In this work we apply techniques and modus operandi typical of Statistical Mechanics to a large dataset about key social quantifiers and compare the resulting behaviors of five European nations, namely France, Germany, Italy, Spain and Switzerland. The social quantifiers considered are i. the evolution of the number of autochthonous marriages (i.e., between two natives) within a given territorial district and ii. the evolution of the number of mixed marriages (i.e., between a native and an immigrant) within a given territorial district. Our investigations are twofold. From a theoretical perspective, we develop novel techniques, complementary to classical methods (e.g., historical series and logistic regression), in order to detect possible collective features underlying the empirical behaviors; from an experimental perspective, we evidence a clear outline for the evolution of the social quantifiers considered. The comparison between experimental results and theoretical predictions is excellent and allows speculating that France, Italy and Spain display a certain degree of internal heterogeneity, that is not found in Germany and Switzerland; such heterogeneity, quite mild in France and in Spain, is not negligible in Italy and highlights quantitative differences in the habits of Northern and Southern regions. These findings may suggest the persistence of two culturally distinct communities, long-term lasting heritages of different and well-established customs. Also, we find qualitative differences between the evolution of autochthonous and of mixed marriages: for the former imitation in decisional mechanisms seems to play a key role (and this results in a square root relation between the number of autochthonous marriages versus the percentage of possible couples inside that country), while for the latter the emerging behavior can be recovered (in most cases) with elementary models with no interactions, suggesting weak imitation patterns between natives and migrants (and this translates in a linear growth for the number of mixed marriages versus the percentage of possible mixed couples in the country). However, the case of mixed marriages displays a more complex phenomenology, where further details (e.g., the provenance and the status of migrants, linguistic barriers, etc.) should also be accounted for.
Predicting field weed emergence with empirical models and soft computing techniques
USDA-ARS?s Scientific Manuscript database
Seedling emergence is the most important phenological process that influences the success of weed species; therefore, predicting weed emergence timing plays a critical role in scheduling weed management measures. Important efforts have been made in the attempt to develop models to predict seedling e...
Brodeur, Jacques; Fournier, François; Martel, Véronique; Vreysen, Marc; Cáceres, Carlos; Firlej, Annabelle
2017-01-01
The spotted wing drosophila Drosophila suzukii Matsumura (Diptera: Drosophilidae), a pest of berries stone fruits, invaded North America and Europe in 2008. Current control methods rely mainly on insecticides. The sterile insect technique (SIT) has potential as an additional control tactic for the integrated management of D. suzukii. As a step towards the development of the SIT, this study aimed at finding the optimum irradiation dose to sterilize D. suzukii under controlled laboratory conditions. Four-day-old D. suzukii pupae were irradiated 12 to 24 hours prior to adult emergence in a 60Co Gamma Cell 220 and in a 137Cs Gamma Cell 3000 with doses of 30, 50, 70, 80, 90, 100 or 120 Gy. Emergence rate (88.1%), percent of deformed flies (4.0%) and survival curves were not affected by the tested irradiation doses. However, some reproductive parameters of the flies were affected by irradiation. Females irradiated with a dose of 50 Gy or more had almost no fecundity. When non-irradiated females were mated with irradiated males, egg hatch decreased exponentially with irradiation dose from 82.6% for the untreated control males to 4.0% for males irradiated with 120 Gy. Mortality of F1 individuals from the irradiated treatment also occurred during larval and pupal stages, with an egg to adult survival of 0.2%. However, descendants produced by the irradiated generation were fertile. These results are an encouraging first experimental step towards the development of the SIT for the management of D. suzukii populations. PMID:28957331
Nonlinear optimization-based device-free localization with outlier link rejection.
Xiao, Wendong; Song, Biao; Yu, Xiting; Chen, Peiyuan
2015-04-07
Device-free localization (DFL) is an emerging wireless technique for estimating the location of target that does not have any attached electronic device. It has found extensive use in Smart City applications such as healthcare at home and hospitals, location-based services at smart spaces, city emergency response and infrastructure security. In DFL, wireless devices are used as sensors that can sense the target by transmitting and receiving wireless signals collaboratively. Many DFL systems are implemented based on received signal strength (RSS) measurements and the location of the target is estimated by detecting the changes of the RSS measurements of the wireless links. Due to the uncertainty of the wireless channel, certain links may be seriously polluted and result in erroneous detection. In this paper, we propose a novel nonlinear optimization approach with outlier link rejection (NOOLR) for RSS-based DFL. It consists of three key strategies, including: (1) affected link identification by differential RSS detection; (2) outlier link rejection via geometrical positional relationship among links; (3) target location estimation by formulating and solving a nonlinear optimization problem. Experimental results demonstrate that NOOLR is robust to the fluctuation of the wireless signals with superior localization accuracy compared with the existing Radio Tomographic Imaging (RTI) approach.
NASA Astrophysics Data System (ADS)
White, Scott R.
This dissertation is a report of an attempt to critically evaluate a novel laboratory course from within the context of a chemical engineering curriculum. The research was done in a college classroom-laboratory setting, entrenched in the everydayness of classroom activities. All of the students, instructors, and educational researchers were knowing participants in this Action Research study. The students, a mixture of juniors, seniors, & graduate students, worked together on semester-long projects in groups that were mixed by age, gender and academic level. Qualitative techniques were used to gather different forms of representations of the students and instructors' experiences. Emergent patterns from the data gave strength to emergent knowledge claims that informed the instructors and the researcher about what the students were learning about performing experimental work and communicating results with their peers and instructor. The course challenged and in some cases changed the conceptions of instruction previously held by the students and the instructors. The course did not proceed without problems, yet the majority of these problems were overcome by the design of the course. Assertions and recommendations for improvement and application to other educational contexts are suggested.
Large scale analysis of the mutational landscape in HT-SELEX improves aptamer discovery
Hoinka, Jan; Berezhnoy, Alexey; Dao, Phuong; Sauna, Zuben E.; Gilboa, Eli; Przytycka, Teresa M.
2015-01-01
High-Throughput (HT) SELEX combines SELEX (Systematic Evolution of Ligands by EXponential Enrichment), a method for aptamer discovery, with massively parallel sequencing technologies. This emerging technology provides data for a global analysis of the selection process and for simultaneous discovery of a large number of candidates but currently lacks dedicated computational approaches for their analysis. To close this gap, we developed novel in-silico methods to analyze HT-SELEX data and utilized them to study the emergence of polymerase errors during HT-SELEX. Rather than considering these errors as a nuisance, we demonstrated their utility for guiding aptamer discovery. Our approach builds on two main advancements in aptamer analysis: AptaMut—a novel technique allowing for the identification of polymerase errors conferring an improved binding affinity relative to the ‘parent’ sequence and AptaCluster—an aptamer clustering algorithm which is to our best knowledge, the only currently available tool capable of efficiently clustering entire aptamer pools. We applied these methods to an HT-SELEX experiment developing aptamers against Interleukin 10 receptor alpha chain (IL-10RA) and experimentally confirmed our predictions thus validating our computational methods. PMID:25870409
Cheng, Lina; Sun, Da-Wen; Zhu, Zhiwei; Zhang, Zi
2017-03-04
Freezing plays an important role in food preservation and the emergence of rapid freezing technologies can be highly beneficial to the food industry. This paper reviews some novel food freezing technologies, including high-pressure freezing (HPF), ultrasound-assisted freezing (UAF), electrically disturbed freezing (EF) and magnetically disturbed freezing (MF), microwave-assisted freezing (MWF), and osmo-dehydro-freezing (ODF). HPF and UAF can initiate ice nucleation rapidly, leading to uniform distribution of ice crystals and the control of their size and shape. Specifically, the former is focused on increasing the degree of supercooling, whereas the latter aims to decrease it. Direct current electric freezing (DC-EF) and alternating current electric freezing (AC-EF) exhibit different effects on ice nucleation. DC-EF can promote ice nucleation and AC-EF has the opposite effect. Furthermore, ODF has been successfully used for freezing various vegetables and fruit. MWF cannot control the nucleation temperature, but can decrease supercooling degree, thus decreasing the size of ice crystals. The heat and mass transfer processes during ODF have been investigated experimentally and modeled mathematically. More studies should be carried out to understand the effects of these technologies on food freezing process.
Qualitative Flow Visualization of a 110-N Hydrogen/Oxygen Laboratory Model Thruster
NASA Technical Reports Server (NTRS)
deGroot, Wim A.; McGuire, Thomas J.; Schneider, Steven J.
1997-01-01
The flow field inside a 110 N gaseous hydrogen/oxygen thruster was investigated using an optically accessible, two-dimensional laboratory test model installed in a high altitude chamber. The injector for this study produced an oxidizer-rich core flow, which was designed to fully mix and react inside a fuel-film sleeve insert before emerging into the main chamber section, where a substantial fuel film cooling layer was added to protect the chamber wall. Techniques used to investigate the flow consisted of spontaneous Raman spectra measurements, visible emission imaging, ultraviolet hydroxyl spectroscopy, and high speed schlieren imaging. Experimental results indicate that the oxygen rich core flow continued to react while emerging from the fuel-film sleeve, suggesting incomplete mixing of the hydrogen in the oxygen rich core flow. Experiments also showed that the fuel film cooling protective layer retained its integrity throughout the straight section of the combustion chamber. In the converging portion of the chamber, however, a turbulent reaction zone near the wall destroyed the integrity of the film layer, a result which implies that a lower contraction angle may improve the fuel film cooling in the converging section and extend the hardware lifetime.
Mac A. Callaham; Matt R. Whiles; John M. Blair
2002-01-01
In tallgrass prairie, cicadas emerge annually, are abundant and their emergence can be an important flux of energy and nutrients. However, factors influencing the distribution and abundance of these cicadas are virtually unknown. We examined cicada emergence in plots from a long-term (13 y) experimental manipulation involving common tallgrass prairie management...
NASA Astrophysics Data System (ADS)
Kurban, Mustafa; Gündüz, Bayram
2017-06-01
In this study, 4-(dicyanomethylene)-2-tert-butyl-6-(1,1,7,7-tetramethyljulolidin-4-yl-vinyl)-4H-pyran (DCJTB) was achieved using the experimental and theoretical studies. The electronic, optical and spectroscopic properties of DCJTB molecule were first investigated by performing experimental both solution and thin film techniques and then theoretical calculations. Theoretical results showed that one intense electronic transition is 505.26 nm a quite reasonable and agreement with the measured experimental data 505.00 and 503 nm with solution technique and film technique, respectively. Experimental and simple models were also taken into consideration to calculate the optical refractive index (n) of DCJTB molecule. The structural and electronic properties were next calculated using density functional theory (DFT) with B3LYP/6-311G (d, p) basis set. UV, FT-IR spectra characteristics and the electronic properties, such as frontier orbitals, and band gap energy (Eg) of DCJTB were also recorded time-dependent (TD) DFT approach. The theoretical Eg value were found to be 2.269 eV which is consistent with experimental results obtained from solution technique for THF solvent (2.155 eV) and literature (2.16 eV). The results herein obtained reveal that solution is simple, cost-efficient and safe for optoelectronic applications when compared with film technique.
Outcomes in Patients Treated with a Novel, Simple Method for Hemostasis of Dermal Avulsion Injuries.
Dowling, Sean Taylor; Lin, Brian Wai
2017-10-01
A recently described technique proposes a simple method to achieve permanent hemostasis of distal fingertip dermal avulsion injuries. It is simple to learn and easy to perform with readily available materials found in most emergency departments. However, long-term outcomes for patients treated with this technique have not yet been evaluated. A primary objective of the current article is to provide safety data for the technique using an off-label product indication. Emergency department of Kaiser Permanente Medical Center, San Francisco, California. Six patients were treated in the emergency department for fingertip dermal avulsion injuries using a tourniquet and tissue adhesive glue (Dermabond by Ethicon, Somerville, New Jersey). Patients were subsequently contacted to assess healing and satisfaction with cosmetic outcome through interview and photographs of their wounds at 9 months following the date of injury. All 6 patients were satisfied with the cosmetic outcome of treatment, and none received a diagnosis of serious complications. This series demonstrates cosmetic outcomes for injuries treated with the technique, highlights potential problems that may be perceived by patients during their clinical course, and creates the groundwork for a larger clinical study examining the use of the technique.
Emergency revegetation to rehabilitate burned watersheds in southern California
Edward S. Corbett; Lisle R. Green
1965-01-01
Reports 4-year results of revegetation measures tested for emergency erosion control after fire denuded the San Dimas Experimental Forest in 1960, including establishment of seeded grasses and their influence on recovery of native vegetation.
Recommended Procedures for Handling Emergency Illnesses and Accidents at School.
ERIC Educational Resources Information Center
North Dakota State Dept. of Health, Bismarck.
Recommended procedures for handling emergency illnesses and accidents are provided in this guide for school personnel prepared by the North Dakota State Department of Health. Following five general recommendations for steps to take in emergency situations, advice and techniques are given for handling: nose bleeds; abdominal pain; toothaches and…
Experimental Evidence for Reduced Rodent Diversity Causing Increased Hantavirus Prevalence
Suzán, Gerardo; Marcé, Erika; Giermakowski, J. Tomasz; Mills, James N.; Ceballos, Gerardo; Ostfeld, Richard S.; Armién, Blas; Pascale, Juan M.; Yates, Terry L.
2009-01-01
Emerging and re-emerging infectious diseases have become a major global environmental problem with important public health, economic, and political consequences. The etiologic agents of most emerging infectious diseases are zoonotic, and anthropogenic environmental changes that affect wildlife communities are increasingly implicated in disease emergence and spread. Although increased disease incidence has been correlated with biodiversity loss for several zoonoses, experimental tests in these systems are lacking. We manipulated small-mammal biodiversity by removing non-reservoir species in replicated field plots in Panama, where zoonotic hantaviruses are endemic. Both infection prevalence of hantaviruses in wild reservoir (rodent) populations and reservoir population density increased where small-mammal species diversity was reduced. Regardless of other variables that affect the prevalence of directly transmitted infections in natural communities, high biodiversity is important in reducing transmission of zoonotic pathogens among wildlife hosts. Our results have wide applications in both conservation biology and infectious disease management. PMID:19421313
Parametric studies and characterization measurements of x-ray lithography mask membranes
NASA Astrophysics Data System (ADS)
Wells, Gregory M.; Chen, Hector T. H.; Engelstad, Roxann L.; Palmer, Shane R.
1991-08-01
The techniques used in the experimental characterization of thin membranes are considered for their potential use as mask blanks for x-ray lithography. Among the parameters of interest for this evaluation are the film's stress, fracture strength, uniformity of thickness, absorption in the x-ray and visible spectral regions and the modulus and grain structure of the material. The experimental techniques used for measuring these properties are described. The accuracy and applicability of the assumptions used to derive the formulas that relate the experimental measurements to the parameters of interest are considered. Experimental results for silicon carbide and diamond films are provided. Another characteristic needed for an x-ray mask carrier is radiation stability. The number of x-ray exposures expected to be performed in the lifetime of an x-ray mask on a production line is on the order of 107. The dimensional stability requirements placed on the membranes during this period are discussed. Interferometric techniques that provide sufficient sensitivity for these stability measurements are described. A comparison is made between the different techniques that have been developed in term of the information that each technique provides, the accuracy of the various techniques, and the implementation issues that are involved with each technique.
Chen, Jie; Yang, Jian; Hu, Fen; Yu, Si-Hong; Yang, Bing-Xiang; Liu, Qian; Zhu, Xiao-Ping
2018-06-01
Simulation-based curriculum has been demonstrated as crucial to nursing education in the development of students' critical thinking and complex clinical skills during a resuscitation simulation. Few studies have comprehensively examined the effectiveness of a standardised simulation-based emergency and intensive care nursing curriculum on the performance of students in a resuscitation simulation. To evaluate the impact of a standardised simulation-based emergency and intensive care nursing curriculum on nursing students' response time in a resuscitation simulation. Two-group, non-randomised quasi-experimental design. A simulation centre in a Chinese University School of Nursing. Third-year nursing students (N = 39) in the Emergency and Intensive Care course were divided into a control group (CG, n = 20) and an experimental group (EG, n = 19). The experimental group participated in a standardised high-technology, simulation-based emergency and intensive care nursing curriculum. The standardised simulation-based curriculum for third-year nursing students consists of three modules: disaster response, emergency care, and intensive care, which include clinical priorities (e.g. triage), basic resuscitation skills, airway/breathing management, circulation management and team work with eighteen lecture hours, six skill-practice hours and twelve simulation hours. The control group took part in the traditional curriculum. This course included the same three modules with thirty-four lecture hours and two skill-practice hours (trauma). Perceived benefits included decreased median (interquartile ranges, IQR) seconds to start compressions [CG 32 (25-75) vs. EG 20 (18-38); p < 0.001] and defibrillation [CG 204 (174-240) vs. EG 167 (162-174); p < 0.001] at the end of the course, compared with compressions [CG 41 (32-49) vs. EG 42 (33-46); p > 0.05] and defibrillation [CG 222 (194-254) vs. EG 221 (214-248); p > 0.05] at the beginning of the course. A simulation-based emergency and intensive care nursing curriculum was created and well received by third-year nursing students and associated with decreased response time in a resuscitation simulation. Copyright © 2018 Elsevier Ltd. All rights reserved.
Research on Group Decision-Making Mechanism of Internet Emergency Management
NASA Astrophysics Data System (ADS)
Xie, Kefan; Chen, Gang; Qian, Wu; Shi, Zhao
With the development of information technology, internet has become a popular term and internet emergency has an intensive influence on people's life. This article offers a short history of internet emergency management. It discusses the definition, characteristics, and factor of internet emergency management. A group decision-making mechanism of internet emergency is presented based on the discussion. The authors establish a so-called Rough Set Scenario Flow Graphs (RSSFG) of group decision-making mechanism of internet emergency management and make an empirical analysis based on the RSSFG approach. The experimental results confirm that this approach is effective in internet emergency decision-making.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Yan, Guanhua; Eidenbenz, Stephan; Ha, Duc T
Botnets, which are networks of compromised machines that are controlled by one or a group of attackers, have emerged as one of the most serious security threats on the Internet. With an army of bots at the scale of tens of thousands of hosts or even as large as 1.5 million PCs, the computational power of botnets can be leveraged to launch large-scale DDoS (Distributed Denial of Service) attacks, sending spamming emails, stealing identities and financial information, etc. As detection and mitigation techniques against botnets have been stepped up in recent years, attackers are also constantly improving their strategies tomore » operate these botnets. The first generation of botnets typically employ IRC (Internet Relay Chat) channels as their command and control (C&C) centers. Though simple and easy to deploy, the centralized C&C mechanism of such botnets has made them prone to being detected and disabled. Against this backdrop, peer-to-peer (P2P) based botnets have emerged as a new generation of botnets which can conceal their C&C communication. Recently, P2P networks have emerged as a covert communication platform for malicious programs known as bots. As popular distributed systems, they allow bots to communicate easily while protecting the botmaster from being discovered. Existing work on P2P-based hotnets mainly focuses on measurement of botnet sizes. In this work, through simulation, we study extensively the structure of P2P networks running Kademlia, one of a few widely used P2P protocols in practice. Our simulation testbed incorporates the actual code of a real Kademlia client software to achieve great realism, and distributed event-driven simulation techniques to achieve high scalability. Using this testbed, we analyze the scaling, reachability, clustering, and centrality properties of P2P-based botnets from a graph-theoretical perspective. We further demonstrate experimentally and theoretically that monitoring bot activities in a P2P network is difficult, suggesting that the P2P mechanism indeed helps botnets hide their communication effectively. Finally, we evaluate the effectiveness of some potential mitigation techniques, such as content poisoning, Sybil-based and Eclipse-based mitigation. Conclusions drawn from this work shed light on the structure of P2P botnets, how to monitor bot activities in P2P networks, and how to mitigate botnet operations effectively.« less
Assessing dynamics, spatial scale, and uncertainty in task-related brain network analyses
Stephen, Emily P.; Lepage, Kyle Q.; Eden, Uri T.; Brunner, Peter; Schalk, Gerwin; Brumberg, Jonathan S.; Guenther, Frank H.; Kramer, Mark A.
2014-01-01
The brain is a complex network of interconnected elements, whose interactions evolve dynamically in time to cooperatively perform specific functions. A common technique to probe these interactions involves multi-sensor recordings of brain activity during a repeated task. Many techniques exist to characterize the resulting task-related activity, including establishing functional networks, which represent the statistical associations between brain areas. Although functional network inference is commonly employed to analyze neural time series data, techniques to assess the uncertainty—both in the functional network edges and the corresponding aggregate measures of network topology—are lacking. To address this, we describe a statistically principled approach for computing uncertainty in functional networks and aggregate network measures in task-related data. The approach is based on a resampling procedure that utilizes the trial structure common in experimental recordings. We show in simulations that this approach successfully identifies functional networks and associated measures of confidence emergent during a task in a variety of scenarios, including dynamically evolving networks. In addition, we describe a principled technique for establishing functional networks based on predetermined regions of interest using canonical correlation. Doing so provides additional robustness to the functional network inference. Finally, we illustrate the use of these methods on example invasive brain voltage recordings collected during an overt speech task. The general strategy described here—appropriate for static and dynamic network inference and different statistical measures of coupling—permits the evaluation of confidence in network measures in a variety of settings common to neuroscience. PMID:24678295
Assessing dynamics, spatial scale, and uncertainty in task-related brain network analyses.
Stephen, Emily P; Lepage, Kyle Q; Eden, Uri T; Brunner, Peter; Schalk, Gerwin; Brumberg, Jonathan S; Guenther, Frank H; Kramer, Mark A
2014-01-01
The brain is a complex network of interconnected elements, whose interactions evolve dynamically in time to cooperatively perform specific functions. A common technique to probe these interactions involves multi-sensor recordings of brain activity during a repeated task. Many techniques exist to characterize the resulting task-related activity, including establishing functional networks, which represent the statistical associations between brain areas. Although functional network inference is commonly employed to analyze neural time series data, techniques to assess the uncertainty-both in the functional network edges and the corresponding aggregate measures of network topology-are lacking. To address this, we describe a statistically principled approach for computing uncertainty in functional networks and aggregate network measures in task-related data. The approach is based on a resampling procedure that utilizes the trial structure common in experimental recordings. We show in simulations that this approach successfully identifies functional networks and associated measures of confidence emergent during a task in a variety of scenarios, including dynamically evolving networks. In addition, we describe a principled technique for establishing functional networks based on predetermined regions of interest using canonical correlation. Doing so provides additional robustness to the functional network inference. Finally, we illustrate the use of these methods on example invasive brain voltage recordings collected during an overt speech task. The general strategy described here-appropriate for static and dynamic network inference and different statistical measures of coupling-permits the evaluation of confidence in network measures in a variety of settings common to neuroscience.
Single-molecule fluorescence microscopy review: shedding new light on old problems
Shashkova, Sviatlana
2017-01-01
Fluorescence microscopy is an invaluable tool in the biosciences, a genuine workhorse technique offering exceptional contrast in conjunction with high specificity of labelling with relatively minimal perturbation to biological samples compared with many competing biophysical techniques. Improvements in detector and dye technologies coupled to advances in image analysis methods have fuelled recent development towards single-molecule fluorescence microscopy, which can utilize light microscopy tools to enable the faithful detection and analysis of single fluorescent molecules used as reporter tags in biological samples. For example, the discovery of GFP, initiating the so-called ‘green revolution’, has pushed experimental tools in the biosciences to a completely new level of functional imaging of living samples, culminating in single fluorescent protein molecule detection. Today, fluorescence microscopy is an indispensable tool in single-molecule investigations, providing a high signal-to-noise ratio for visualization while still retaining the key features in the physiological context of native biological systems. In this review, we discuss some of the recent discoveries in the life sciences which have been enabled using single-molecule fluorescence microscopy, paying particular attention to the so-called ‘super-resolution’ fluorescence microscopy techniques in live cells, which are at the cutting-edge of these methods. In particular, how these tools can reveal new insights into long-standing puzzles in biology: old problems, which have been impossible to tackle using other more traditional tools until the emergence of new single-molecule fluorescence microscopy techniques. PMID:28694303
Safe emergency department removal of a hardened steel penile constriction ring.
Peay, Jeremy; Smithson, James; Nelson, James; Witucki, Peter
2009-10-01
Penile constriction devices are used for the enhancement of sexual performance. These devices have the potential to become incarcerated, leading to necrosis and amputation if not removed promptly. This article presents a step-by-step approach for the safe removal of a hardened steel penile constriction device using somewhat unorthodox tools found in a hospital. We present a case of an incarcerated hardened steel penile constriction ring that was not able to be removed with conventional techniques. We describe a novel technique using an electric grinder and laryngoscope blade. The technique described in this article is a valuable and relatively safe technique for the Emergency Physician to facilitate the timely removal of a hardened steel constriction device.
Emerging applications of fluorescence spectroscopy in medical microbiology field.
Shahzad, Aamir; Köhler, Gottfried; Knapp, Martin; Gaubitzer, Erwin; Puchinger, Martin; Edetsberger, Michael
2009-11-26
There are many diagnostic techniques and methods available for diagnosis of medically important microorganisms like bacteria, viruses, fungi and parasites. But, almost all these techniques and methods have some limitations or inconvenience. Most of these techniques are laborious, time consuming and with chances of false positive or false negative results. It warrants the need of a diagnostic technique which can overcome these limitations and problems. At present, there is emerging trend to use Fluorescence spectroscopy as a diagnostic as well as research tool in many fields of medical sciences. Here, we will critically discuss research studies which propose that Fluorescence spectroscopy may be an excellent diagnostic as well as excellent research tool in medical microbiology field with high sensitivity and specificity.
Real-time spectral interferometry probes the internal dynamics of femtosecond soliton molecules
NASA Astrophysics Data System (ADS)
Herink, G.; Kurtz, F.; Jalali, B.; Solli, D. R.; Ropers, C.
2017-04-01
Solitons, particle-like excitations ubiquitous in many fields of physics, have been shown to exhibit bound states akin to molecules. The formation of such temporal soliton bound states and their internal dynamics have escaped direct experimental observation. By means of an emerging time-stretch technique, we resolve the evolution of femtosecond soliton molecules in the cavity of a few-cycle mode-locked laser. We track two- and three-soliton bound states over hundreds of thousands of consecutive cavity roundtrips, identifying fixed points and periodic and aperiodic molecular orbits. A class of trajectories acquires a path-dependent geometrical phase, implying that its dynamics may be topologically protected. These findings highlight the importance of real-time detection in resolving interactions in complex nonlinear systems, including the dynamics of soliton bound states, breathers, and rogue waves.
INITIAL ASSESSMENT OF SURFACE PRESSURE CHARACTERISTICS OF TWO ROTARY WING UAV DESIGNS
NASA Technical Reports Server (NTRS)
Jones, Henry E.; Wong, Oliver D.; Watkins, A. Neal; Noonan, Kevin W.; Reis, Deane G.; Malovrh, Brendon D.; Ingram, Joanne L.
2006-01-01
This paper presents results of an experimental investigation of two rotary-wing UAV designs. The primary goal of the investigation was to provide a set of interactional aerodynamic data for an emerging class of rotorcraft. The present paper provides an overview of the test and an introduction to the test articles, and instrumentation. Sample data in the form of fixed system pressure coefficient response to changes in configuration attitude and flight condition for both rotor off and on conditions are presented. The presence of the rotor is seen to greatly affect the magnitude of the response. Pressure coefficients were measured using both conventional pressure taps and via pressure sensitive paint. Comparisons between the two methods are presented and demonstrate that the pressure sensitive paint is a promising method; however, further work on the technique is required.
Towards Memory-Aware Services and Browsing through Lifelogging Sensing
Arcega, Lorena; Font, Jaime; Cetina, Carlos
2013-01-01
Every day we receive lots of information through our senses that is lost forever, because it lacked the strength or the repetition needed to generate a lasting memory. Combining the emerging Internet of Things and lifelogging sensors, we believe it is possible to build up a Digital Memory (Dig-Mem) in order to complement the fallible memory of people. This work shows how to realize the Dig-Mem in terms of interactions, affinities, activities, goals and protocols. We also complement this Dig-Mem with memory-aware services and a Dig-Mem browser. Furthermore, we propose a RFID Tag-Sharing technique to speed up the adoption of Dig-Mem. Experimentation reveals an improvement of the user understanding of Dig-Mem as time passes, compared to natural memories where the level of detail decreases over time. PMID:24196436
Podgorny, Irina
2011-01-01
By considering the work of American embalmer, lawyer, and physician Carl Lewis Barnes (1872-1927), this paper analyzes the emergence of modern embalming in America. Barnes experimented with and exhibited the techniques by which embalming fluids travelled into the most remote cavities of the human body. In this sense, modem embalmers based their skills and methods on experimental medicine, turning the anatomy of blood vessels, physiology of circulation, and composition of blood into a circuit that allowed embalming fluids to move throughout the corpse. Embalmers in the late 19th century took ownership of the laws of hydrodynamics and the physiology of blood circulation to market their fluids and equipment, thus playing the role of physiologists of death, performing and demonstrating physiological experiments with dead bodies.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Roberts, Scott A.; Mendoza, Hector; Brunini, Victor E.
Battery performance, while observed at the macroscale, is primarily governed by the bicontinuous mesoscale network of the active particles and a polymeric conductive binder in its electrodes. Manufacturing processes affect this mesostructure, and therefore battery performance, in ways that are not always clear outside of empirical relationships. Directly studying the role of the mesostructure is difficult due to the small particle sizes (a few microns) and large mesoscale structures. Mesoscale simulation, however, is an emerging technique that allows the investigation into how particle-scale phenomena affect electrode behavior. In this manuscript, we discuss our computational approach for modeling electrochemical, mechanical, andmore » thermal phenomena of lithium-ion batteries at the mesoscale. Here, we review our recent and ongoing simulation investigations and discuss a path forward for additional simulation insights.« less
Laser post-processing of halide perovskites for enhanced photoluminescence and absorbance
NASA Astrophysics Data System (ADS)
Tiguntseva, E. Y.; Saraeva, I. N.; Kudryashov, S. I.; Ushakova, E. V.; Komissarenko, F. E.; Ishteev, A. R.; Tsypkin, A. N.; Haroldson, R.; Milichko, V. A.; Zuev, D. A.; Makarov, S. V.; Zakhidov, A. A.
2017-11-01
Hybrid halide perovskites have emerged as one of the most promising type of materials for thin-film photovoltaic and light-emitting devices. Further boosting their performance is critically important for commercialization. Here we use femtosecond laser for post-processing of organo-metalic perovskite (MAPbI3) films. The high throughput laser approaches include both ablative silicon nanoparticles integration and laser-induced annealing. By using these techniques, we achieve strong enhancement of photoluminescence as well as useful light absorption. As a result, we observed experimentally 10-fold enhancement of absorbance in a perovskite layer with the silicon nanoparticles. Direct laser annealing allows for increasing of photoluminescence over 130%, and increase absorbance over 300% in near-IR range. We believe that the developed approaches pave the way to novel scalable and highly effective designs of perovskite based devices.
Wang, Luda; Boutilier, Michael S H; Kidambi, Piran R; Jang, Doojoon; Hadjiconstantinou, Nicolas G; Karnik, Rohit
2017-06-06
Graphene and other two-dimensional materials offer a new approach to controlling mass transport at the nanoscale. These materials can sustain nanoscale pores in their rigid lattices and due to their minimum possible material thickness, high mechanical strength and chemical robustness, they could be used to address persistent challenges in membrane separations. Here we discuss theoretical and experimental developments in the emerging field of nanoporous atomically thin membranes, focusing on the fundamental mechanisms of gas- and liquid-phase transport, membrane fabrication techniques and advances towards practical application. We highlight potential functional characteristics of the membranes and discuss applications where they are expected to offer advantages. Finally, we outline the major scientific questions and technological challenges that need to be addressed to bridge the gap from theoretical simulations and proof-of-concept experiments to real-world applications.
Roberts, Scott A.; Mendoza, Hector; Brunini, Victor E.; ...
2016-10-20
Battery performance, while observed at the macroscale, is primarily governed by the bicontinuous mesoscale network of the active particles and a polymeric conductive binder in its electrodes. Manufacturing processes affect this mesostructure, and therefore battery performance, in ways that are not always clear outside of empirical relationships. Directly studying the role of the mesostructure is difficult due to the small particle sizes (a few microns) and large mesoscale structures. Mesoscale simulation, however, is an emerging technique that allows the investigation into how particle-scale phenomena affect electrode behavior. In this manuscript, we discuss our computational approach for modeling electrochemical, mechanical, andmore » thermal phenomena of lithium-ion batteries at the mesoscale. Here, we review our recent and ongoing simulation investigations and discuss a path forward for additional simulation insights.« less
NASA Astrophysics Data System (ADS)
Annetta, Leonard A.; Cheng, Meng-Tzu; Holmes, Shawn
2010-07-01
As twenty-first century skills become a greater focus in K-12 education, an infusion of technology that meets the needs of today's students is paramount. This study looks at the design and creation of a Multiplayer Educational Gaming Application (MEGA) for high school biology students. The quasi-experimental, qualitative design assessed the twenty-first century skills of digital age literacy, inventive thinking, high productivity, and effective communication techniques of the students exposed to a MEGA. Three factors, as they pertained to these skills, emerged from classroom observations. Interaction with the teacher, discussion with peers, and engagement/time-on-task while playing the MEGA suggested that students playing an educational video game exhibited all of the projected twenty-first century skills while being engrossed in the embedded science content.
Transcranial direct current stimulation: a noninvasive tool to facilitate stroke recovery
Schlaug, Gottfried; Renga, Vijay
2011-01-01
Electrical brain stimulation, a technique developed many decades ago and then largely forgotten, has re-emerged recently as a promising tool for experimental neuroscientists, clinical neurologists and psychiatrists in their quest to causally probe cortical representations of sensorimotor and cognitive functions and to facilitate the treatment of various neuropsychiatric disorders. In this regard, a better understanding of adaptive and maladaptive plasticity in natural stroke recovery over the last decade and the idea that brain polarization may modulate neuroplasticity has led to the use of transcranial direct current stimulation (tDCS) as a potential enhancer of natural stroke recovery. We will review tDCS’s successful utilization in pilot and proof-of-principle stroke recovery studies, the different modes of tDCS currently in use, and the potential mechanisms underlying the neural effects of tDCS. PMID:19025351
DOE Office of Scientific and Technical Information (OSTI.GOV)
Galperin, Michael
The progress of experimental techniques at the nanoscale in the last decade made optical measurements in current-carrying nanojunctions a reality, thus indicating the emergence of a new field of research coined optoelectronics. Optical spectroscopy of open nonequilibrium systems is a natural meeting point for (at least) two research areas: nonlinear optical spectroscopy and quantum transport, each with its own theoretical toolbox. We review recent progress in the field comparing theoretical treatments of optical response in nanojunctions as is accepted in nonlinear spectroscopy and quantum transport communities. A unified theoretical description of spectroscopy in nanojunctions is presented. Here, we argue thatmore » theoretical approaches of the quantum transport community (and in particular, the Green function based considerations) yield a convenient tool for optoelectronics when the radiation field is treated classically, and that differences between the toolboxes may become critical when studying the quantum radiation field in junctions.« less
Learning Compositional Simulation Models
2010-01-01
techniques developed by social scientists, economists, and medical researchers over the past four decades. Quasi-experimental designs (QEDs) are...statistical techniques from the social sciences known as quasi- experimental design (QED). QEDs allow a researcher to exploit unique characteristics...can be grouped under the rubric “quasi-experimental design ” (QED), and they attempt to exploit inherent characteristics of observational data sets
Emergency Services at NCI at Frederick | Poster
Despite precautions and preventive techniques, injuries and emergencies can happen at NCI at Frederick. When they occur, employees should call the same number as they would when they are off-campus: 911.
Fundamentals of functional imaging II: emerging MR techniques and new methods of analysis.
Luna, A; Martín Noguerol, T; Mata, L Alcalá
2018-05-01
Current multiparameter MRI protocols integrate structural, physiological, and metabolic information about cancer. Emerging techniques such as arterial spin-labeling (ASL), blood oxygen level dependent (BOLD), MR elastography, chemical exchange saturation transfer (CEST), and hyperpolarization provide new information and will likely be integrated into daily clinical practice in the near future. Furthermore, there is great interest in the study of tumor heterogeneity as a prognostic factor and in relation to resistance to treatment, and this interest is leading to the application of new methods of analysis of multiparametric protocols. In parallel, new oncologic biomarkers that integrate the information from MR with clinical, laboratory, genetic, and histologic findings are being developed, thanks to the application of big data and artificial intelligence. This review analyzes different emerging MR techniques that are able to evaluate the physiological, metabolic, and mechanical characteristics of cancer, as well as the main clinical applications of these techniques. In addition, it summarizes the most novel methods of analysis of functional radiologic information in oncology. Copyright © 2018 SERAM. Publicado por Elsevier España, S.L.U. All rights reserved.
Karen L. Pope; Jonah Piovia-Scott; Sharon P. Lawler
2009-01-01
1.âInsects emerging from mountain lakes provide an important food source for many terrestrial predators. The amount of insect subsidy that emerges from lakes is influenced by predator composition, but predator effects could be ameliorated by greater habitat complexity. We conducted a replicated whole-lake experiment to test the effects of introduced fish...
ERIC Educational Resources Information Center
Elrick, Mike
2003-01-01
Traditional techniques and gear are better suited for comfortable extended wilderness trips with high school students than are emerging technologies and techniques based on low-impact camping and petroleum-based clothing, which send students the wrong messages about ecological relatedness and sustainability. Traditional travel techniques and…
Robust dynamical decoupling for quantum computing and quantum memory.
Souza, Alexandre M; Alvarez, Gonzalo A; Suter, Dieter
2011-06-17
Dynamical decoupling (DD) is a popular technique for protecting qubits from the environment. However, unless special care is taken, experimental errors in the control pulses used in this technique can destroy the quantum information instead of preserving it. Here, we investigate techniques for making DD sequences robust against different types of experimental errors while retaining good decoupling efficiency in a fluctuating environment. We present experimental data from solid-state nuclear spin qubits and introduce a new DD sequence that is suitable for quantum computing and quantum memory.
ERIC Educational Resources Information Center
National Highway Traffic Safety Administration (DOT), Washington, DC.
This set of instructor's lesson plans is one of three documents prepared for the Emergency Medical Technician (EMT) National Standard Curriculum. It contains detailed outlines of course content and guidance for teaching each course lesson. The training course contains 33 lessons covering all emergency medical techniques currently considered to be…
Basic Training Course/Emergency Medical Technician (Second Edition). Instructor's Lesson Plan.
ERIC Educational Resources Information Center
National Highway Traffic Safety Administration (DOT), Washington, DC.
This document containing instructor lesson plans is one of three prepared to update a basic training program for emergency medical technicians (EMTs). (A course guide containing planning and management information and a study guide are available separately.) Material covers all emergency medical techniques currently considered to be within the…
NASA Blue Team: Determining Operational Security Posture of Critical Systems and Networks
NASA Technical Reports Server (NTRS)
Alley, Adam David
2016-01-01
Emergence of Cybersecurity has increased the focus on security risks to Information Technology (IT) assets going beyond traditional Information Assurance (IA) concerns: More sophisticated threats have emerged from increasing sources as advanced hacker tools and techniques have emerged and proliferated to broaden the attack surface available across globally interconnected networks.
Using the Technique of Journal Writing to Learn Emergency Psychiatry
ERIC Educational Resources Information Center
Bhuvaneswar, Chaya; Stern, Theodore; Beresin, Eugene
2009-01-01
Objective: The authors discuss journal writing in learning emergency psychiatry. Methods: The journal of a psychiatry intern rotating through an emergency department is used as sample material for analysis that could take place in supervision or a resident support group. A range of articles are reviewed that illuminate the relevance of journal…
ERIC Educational Resources Information Center
Ohio State Dept. of Education, Columbus. Div. of Vocational Education.
This student manual, the fifth in a set of 14 modules, is designed to train emergency medical technicians (EMTs) in Ohio. The module contains two sections covering the following course content; cardiopulmonary resuscitation (CPR) (including artificial ventilation, foreign body obstructions, adjunctive equipment and special techniques, artificial…
Culp, Joseph M; Cash, Kevin J; Glozier, Nancy E; Brua, Robert B
2003-12-01
We used mesocosms to examine the impact of different concentrations of pulp mill effluent (PME) on structural and functional endpoints of a benthic assemblage in the Saint John River (NB, Canada) during 1999 and 2000. Previous studies on this effluent's effects produced conflicting results, with field surveys suggesting a pattern of mild nutrient enrichment, while laboratory toxicity tests linked effluent exposure to moderate contaminant effects. Experimental treatments included three concentrations of sulfite pulp mill effluent (0, 5, 10% v/v PME). Endpoints for the assessment included algal biomass and taxonomic composition, benthic invertebrate abundance and composition, and insect emergence. Low concentrations of PME increased periphyton biomass and caused changes in community structure within the diatom-dominated community. Pulp mill effluent addition had little effect on several structural endpoints measured for benthic invertebrates, including abundance and taxonomic richness, but significantly changed community composition. For both periphyton and benthic invertebrates, community composition endpoints were more sensitive indicators of PME exposure. Insect emergence was a highly relevant functional endpoint. When benthic and emerged insects were combined, total abundance increased with PME addition. Results from two trophic levels, which provided multiple lines of evidence, indicated that the main impact of these PME concentrations is nutrient enrichment rather than effluent toxicity. Our findings also suggest that benthic invertebrate and periphyton assemblages, algal biomass production, and insect emergence are sensitive response measures. Future studies may confirm this observation. The consideration of both functional and structural endpoints at different trophic levels can greatly improve our understanding the effects of discharges to rivers. Such an understanding could not have been obtained using standard assessment techniques and illustrates the value of mesocosms and the benthic community assemblage approach in environmental assessment.
Soviet ionospheric modification research
DOE Office of Scientific and Technical Information (OSTI.GOV)
Duncan, L.M.; Carlson, H.C.; Djuth, F.T.
1988-07-01
Soviet published literature in ionospheric modification research by high-power radio waves is assessed, including an evaluation of its impact on and applications to future remote-sensing and telecommunications systems. This assessment is organized to place equal emphasis on basic research activities, designed to investigate both the natural geophysical environment and fundamental plasma physics; advanced research programs, such as those studying artificial ionization processes and oblique high-power radio propagation and practical system applications and operational limitations addressed by this research. The assessment indicates that the Soviet Union sustains high-quality theoretical and experimental research programs in ionospheric modification, with a breadth and levelmore » of effort greatly exceeding comparable Western programs. Soviet theoretical research tends to be analytical and intuitive, as compared to the Western emphasis on numerical simulation techniques. The Soviet experimental approach is less exploratory, designed principally to confirm theoretical predictions. Although limited by inferior diagnostic capabilities, Soviet experimental facilities are more numerous, operate on a more regular basis, and transmit radio wave powers exceeding those os Western facilities. Because of its broad scope of activity, the Soviet Union is better poised to quickly exploit new technologies and system applications as they are developed. This panel has identified several key areas of Soviet research activity and emerging technology that may offer long-term opportunities for remote-sensing and telecommunications advantages. However, we have found no results that suggest imminent breakthrough discoveries in these fields.« less
Ennouri, Karim; Ayed, Rayda Ben; Hassen, Hanen Ben; Mazzarello, Maura; Ottaviani, Ennio
2015-12-01
Bacillus thuringiensis (Bt) is a Gram-positive bacterium. The entomopathogenic activity of Bt is related to the existence of the crystal consisting of protoxins, also called delta-endotoxins. In order to optimize and explain the production of delta-endotoxins of Bacillus thuringiensis kurstaki, we studied seven medium components: soybean meal, starch, KH₂PO₄, K₂HPO₄, FeSO₄, MnSO₄, and MgSO₄and their relationships with the concentration of delta-endotoxins using an experimental design (Plackett-Burman design) and Bayesian networks modelling. The effects of the ingredients of the culture medium on delta-endotoxins production were estimated. The developed model showed that different medium components are important for the Bacillus thuringiensis fermentation. The most important factors influenced the production of delta-endotoxins are FeSO₄, K2HPO₄, starch and soybean meal. Indeed, it was found that soybean meal, K₂HPO₄, KH₂PO₄and starch also showed positive effect on the delta-endotoxins production. However, FeSO4 and MnSO4 expressed opposite effect. The developed model, based on Bayesian techniques, can automatically learn emerging models in data to serve in the prediction of delta-endotoxins concentrations. The constructed model in the present study implies that experimental design (Plackett-Burman design) joined with Bayesian networks method could be used for identification of effect variables on delta-endotoxins variation.
Single-cell epigenomics: techniques and emerging applications.
Schwartzman, Omer; Tanay, Amos
2015-12-01
Epigenomics is the study of the physical modifications, associations and conformations of genomic DNA sequences, with the aim of linking these with epigenetic memory, cellular identity and tissue-specific functions. While current techniques in the field are characterizing the average epigenomic features across large cell ensembles, the increasing interest in the epigenetics within complex and heterogeneous tissues is driving the development of single-cell epigenomics. We review emerging single-cell methods for capturing DNA methylation, chromatin accessibility, histone modifications, chromosome conformation and replication dynamics. Together, these techniques are rapidly becoming a powerful tool in studies of cellular plasticity and diversity, as seen in stem cells and cancer.
Emergency treatment of exertional heatstroke and comparison of whole body cooling techniques.
Costrini, A
1990-02-01
This manuscript compares the whole body cooling techniques in the emergency treatment of heatstroke. Historically, the use of cold water immersion with skin massage has been quite successful in rapidly lowering body temperature and in avoiding severe complications or death. Recent studies have suggested alternative therapies, including the use of a warm air spray, the use of helicopter downdraft, and pharmacological agents. While evidence exists to support these methods, they have not been shown to reduce fatalities as effectively as ice water immersion. Although several cooling methods may have clinical use, all techniques rely on the prompt recognition of symptoms and immediate action in the field.
Beliaev, A M; Bagnenko, S F; Kabanov, M Iu; Vashetko, R V; Surov, D A; Zakharenko, A A; Babkov, O V; Koshevoĭ, A A; Novitskaia, N Iu; Rumiantsev, V N
2011-01-01
In order to improve radicalism of emergency surgical interventions an appropriate method of total mesocolonectomy and D3-lymph node dissection in the medial-lateral direction and the principle of "no-touch technique" were used in 14 patients. This technique is safe, effective, does not prolong the duration of operation and postoperative period, is not followed by increased number of complications and lethality.
An Experimental Study for Effectiveness of Super-Learning Technique at Elementary Level in Pakistan
ERIC Educational Resources Information Center
Shafqat, Hussain; Muhammad, Sarwar; Imran, Yousaf; Naemullah; Inamullah
2010-01-01
The objective of the study was to experience the effectiveness of super-learning technique of teaching at elementary level. The study was conducted with 8th grade students at a public sector school. Pre-test and post-test control group designs were used. Experimental and control groups were formed randomly, the experimental group (N = 62),…
Numerical model updating technique for structures using firefly algorithm
NASA Astrophysics Data System (ADS)
Sai Kubair, K.; Mohan, S. C.
2018-03-01
Numerical model updating is a technique used for updating the existing experimental models for any structures related to civil, mechanical, automobiles, marine, aerospace engineering, etc. The basic concept behind this technique is updating the numerical models to closely match with experimental data obtained from real or prototype test structures. The present work involves the development of numerical model using MATLAB as a computational tool and with mathematical equations that define the experimental model. Firefly algorithm is used as an optimization tool in this study. In this updating process a response parameter of the structure has to be chosen, which helps to correlate the numerical model developed with the experimental results obtained. The variables for the updating can be either material or geometrical properties of the model or both. In this study, to verify the proposed technique, a cantilever beam is analyzed for its tip deflection and a space frame has been analyzed for its natural frequencies. Both the models are updated with their respective response values obtained from experimental results. The numerical results after updating show that there is a close relationship that can be brought between the experimental and the numerical models.
NASA Astrophysics Data System (ADS)
Klemens Zaplata, Markus; Veste, Maik; Pohle, Ina; Schümberg, Sabine; Abreu Schonert, Iballa; Hinz, Christoph
2016-04-01
While there are hints that biological soil crusts (BSCs) can constitute physical barriers for the emergence of vascular plants, a conceptual approach for the quantitative evaluation of these effects is still missing. Here we present an experimental design to test the emergence of seedlings in situ with (i) capping natural intact, (ii) destroyed and (iii) removed BSC. The selected field site is directly adjacent to the constructed Hühnerwasser catchment (Lusatia, Germany). This site exists since the end of 2008 and consists of loamy sand. Serving as proxy for seedling thrust, we inserted pre-germinated seeds of three confamiliar plant species with different seed masses (members of the Fabaceae family: Lotus corniculatus L., Ornithopus sativus Brot., and Glycine max (L.) Merr.). In each treatment as well as in the control group planting depths were 10 mm. We took care that experimental plots had identical crust thickness, slightly less than 4 mm, serving as proxy for mechanical resistance. A plot became established as follows: Firstly, the pristine crusted surface was vertically cut. To the windward side the BSC remained intact (i: "with BSC" stripe). To the downwind side soil material was temporarily excavated for laterally inserting the seeds beneath the surface of the first stripe. Then at the thereby disturbed second stripe pulverised BSC material became filled as a top layer (ii: "BSC mix" stripe). From the next stripe the BSC was removed (iii: "no BSC" stripe). Thus each plot had each experimental group in spatial contiguity (within 50 cm × 50 cm). The overall 50 plots were distributed across an area of 40 m × 12 m. When individuals of a species either emerged at all stripes, "× × ×", or at no stripe of a plot, "- - -", there was no reason to suppose any effect of a crust. The "- × ×" emergence pattern (depicting the appearance of seedlings in both stripes possessing manipulated surfaces) points towards hindrance more clearly than "- × -" or "- - ×". Altogether eight possible combinations exist. Combinatorial analysis turned out that seedling emergence had been notably impeded for light-weighted seeds but little for heavy seeds. Repeated recordings enable to account for adaptable emergence of seedlings according to varying crust conditions - in spatial as well as temporal terms. The proposed experimental procedure hence is highly recommended as a viable instrument to further investigate filter and facilitation processes between BSCs and vascular plants.
Goldsborough, S. Scott; Hochgreb, Simone; Vanhove, Guillaume; ...
2017-07-10
Rapid compression machines (RCMs) are widely-used to acquire experimental insights into fuel autoignition and pollutant formation chemistry, especially at conditions relevant to current and future combustion technologies. RCM studies emphasize important experimental regimes, characterized by low- to intermediate-temperatures (600–1200 K) and moderate to high pressures (5–80 bar). At these conditions, which are directly relevant to modern combustion schemes including low temperature combustion (LTC) for internal combustion engines and dry low emissions (DLE) for gas turbine engines, combustion chemistry exhibits complex and experimentally challenging behaviors such as the chemistry attributed to cool flame behavior and the negative temperature coefficient regime. Challengesmore » for studying this regime include that experimental observations can be more sensitive to coupled physical-chemical processes leading to phenomena such as mixed deflagrative/autoignitive combustion. Experimental strategies which leverage the strengths of RCMs have been developed in recent years to make RCMs particularly well suited for elucidating LTC and DLE chemistry, as well as convolved physical-chemical processes. Specifically, this work presents a review of experimental and computational efforts applying RCMs to study autoignition phenomena, and the insights gained through these efforts. A brief history of RCM development is presented towards the steady improvement in design, characterization, instrumentation and data analysis. Novel experimental approaches and measurement techniques, coordinated with computational methods are described which have expanded the utility of RCMs beyond empirical studies of explosion limits to increasingly detailed understanding of autoignition chemistry and the role of physical-chemical interactions. Fundamental insight into the autoignition chemistry of specific fuels is described, demonstrating the extent of knowledge of low-temperature chemistry derived from RCM studies, from simple hydrocarbons to multi-component blends and full-boiling range fuels. In conclusion, emerging needs and further opportunities are suggested, including investigations of under-explored fuels and the implementation of increasingly higher fidelity diagnostics.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Goldsborough, S. Scott; Hochgreb, Simone; Vanhove, Guillaume
Rapid compression machines (RCMs) are widely-used to acquire experimental insights into fuel autoignition and pollutant formation chemistry, especially at conditions relevant to current and future combustion technologies. RCM studies emphasize important experimental regimes, characterized by low- to intermediate-temperatures (600–1200 K) and moderate to high pressures (5–80 bar). At these conditions, which are directly relevant to modern combustion schemes including low temperature combustion (LTC) for internal combustion engines and dry low emissions (DLE) for gas turbine engines, combustion chemistry exhibits complex and experimentally challenging behaviors such as the chemistry attributed to cool flame behavior and the negative temperature coefficient regime. Challengesmore » for studying this regime include that experimental observations can be more sensitive to coupled physical-chemical processes leading to phenomena such as mixed deflagrative/autoignitive combustion. Experimental strategies which leverage the strengths of RCMs have been developed in recent years to make RCMs particularly well suited for elucidating LTC and DLE chemistry, as well as convolved physical-chemical processes. Specifically, this work presents a review of experimental and computational efforts applying RCMs to study autoignition phenomena, and the insights gained through these efforts. A brief history of RCM development is presented towards the steady improvement in design, characterization, instrumentation and data analysis. Novel experimental approaches and measurement techniques, coordinated with computational methods are described which have expanded the utility of RCMs beyond empirical studies of explosion limits to increasingly detailed understanding of autoignition chemistry and the role of physical-chemical interactions. Fundamental insight into the autoignition chemistry of specific fuels is described, demonstrating the extent of knowledge of low-temperature chemistry derived from RCM studies, from simple hydrocarbons to multi-component blends and full-boiling range fuels. In conclusion, emerging needs and further opportunities are suggested, including investigations of under-explored fuels and the implementation of increasingly higher fidelity diagnostics.« less
Manganas, A; Tsiknakis, M; Leisch, E; Ponder, M; Molet, T; Herbelin, B; Magnetat-Thalmann, N; Thalmann, D; Fato, M; Schenone, A
2004-01-01
This paper reports the results of the second of the two systems developed by JUST, a collaborative project supported by the European Union under the Information Society Technologies (IST) Programme. The most innovative content of the project has been the design and development of a complementary training course for non-professional health emergency operators, which supports the traditional learning phase, and which purports to improve the retention capability of the trainees. This was achieved with the use of advanced information technology techniques, which provide adequate support and can help to overcome the present weaknesses of the existing training mechanisms.
NASA Astrophysics Data System (ADS)
Karimi, M.; Seraji, F. E.
2010-01-01
We report a new simple technique for the simultaneous measurements of absorption-, emission cross-sections, background loss coefficient, and dopant density of doped optical fibers with low dopant concentration. Using our proposed technique, the experimental characterization of a sample Ge-Er-doped optical fiber is presented, and the results are analyzed and compared with other reports. This technique is suitable for production line of doped optical fibers.
Flow in prosthetic heart valves: state-of-the-art and future directions.
Yoganathan, Ajit P; Chandran, K B; Sotiropoulos, Fotis
2005-12-01
Since the first successful implantation of a prosthetic heart valve four decades ago, over 50 different designs have been developed including both mechanical and bioprosthetic valves. Today, the most widely implanted design is the mechanical bileaflet, with over 170,000 implants worldwide each year. Several different mechanical valves are currently available and many of them have good bulk forward flow hemodynamics, with lower transvalvular pressure drops, larger effective orifice areas, and fewer regions of forward flow stasis than their earlier-generation counterparts such as the ball-and-cage and tilting-disc valves. However, mechanical valve implants suffer from complications resulting from thrombus deposition and patients implanted with these valves need to be under long-term anti-coagulant therapy. In general, blood thinners are not needed with bioprosthetic implants, but tissue valves suffer from structural failure with, an average life-time of 10-12 years, before replacement is needed. Flow-induced stresses on the formed elements in blood have been implicated in thrombus initiation within the mechanical valve prostheses. Regions of stress concentration on the leaflets during the complex motion of the leaflets have been implicated with structural failure of the leaflets with bioprosthetic valves. In vivo and in vitro experimental studies have yielded valuable information on the relationship between hemodynamic stresses and the problems associated with the implants. More recently, Computational Fluid Dynamics (CFD) has emerged as a promising tool, which, alongside experimentation, can yield insights of unprecedented detail into the hemodynamics of prosthetic heart valves. For CFD to realize its full potential, however, it must rely on numerical techniques that can handle the enormous geometrical complexities of prosthetic devices with spatial and temporal resolution sufficiently high to accurately capture all hemodynamically relevant scales of motion. Such algorithms do not exist today and their development should be a major research priority. For CFD to further gain the confidence of valve designers and medical practitioners it must also undergo comprehensive validation with experimental data. Such validation requires the use of high-resolution flow measuring tools and techniques and the integration of experimental studies with CFD modeling.
A Consensus-Driven Agenda for Emergency Medicine Firearm Injury Prevention Research.
Ranney, Megan L; Fletcher, Jonathan; Alter, Harrison; Barsotti, Christopher; Bebarta, Vikhyat S; Betz, Marian E; Carter, Patrick M; Cerdá, Magdalena; Cunningham, Rebecca M; Crane, Peter; Fahimi, Jahan; Miller, Matthew J; Rowhani-Rahbar, Ali; Vogel, Jody A; Wintemute, Garen J; Waseem, Muhammad; Shah, Manish N
2017-02-01
To identify critical emergency medicine-focused firearm injury research questions and develop an evidence-based research agenda. National content experts were recruited to a technical advisory group for the American College of Emergency Physicians Research Committee. Nominal group technique was used to identify research questions by consensus. The technical advisory group decided to focus on 5 widely accepted categorizations of firearm injury. Subgroups conducted literature reviews on each topic and developed preliminary lists of emergency medicine-relevant research questions. In-person meetings and conference calls were held to iteratively refine the extensive list of research questions, following nominal group technique guidelines. Feedback from external stakeholders was reviewed and integrated. Fifty-nine final emergency medicine-relevant research questions were identified, including questions that cut across all firearm injury topics and questions specific to self-directed violence (suicide and attempted suicide), intimate partner violence, peer (nonpartner) violence, mass violence, and unintentional ("accidental") injury. Some questions could be addressed through research conducted in emergency departments; others would require work in other settings. The technical advisory group identified key emergency medicine-relevant firearm injury research questions. Emergency medicine-specific data are limited for most of these questions. Funders and researchers should consider increasing their attention to firearm injury prevention and control, particularly to the questions identified here and in other recently developed research agendas. Copyright © 2016 American College of Emergency Physicians. Published by Elsevier Inc. All rights reserved.
Piekny, Jeanette; Maehler, Claudia
2013-06-01
According to Klahr's (2000, 2005; Klahr & Dunbar, 1988) Scientific Discovery as Dual Search model, inquiry processes require three cognitive components: hypothesis generation, experimentation, and evidence evaluation. The aim of the present study was to investigate (a) when the ability to evaluate perfect covariation, imperfect covariation, and non-covariation evidence emerges, (b) when experimentation emerges, (c) when hypothesis generation skills emerge, and (d), whether these abilities develop synchronously during childhood. We administered three scientific reasoning tasks referring to the three components to 223 children of five age groups (from age 4.0 to 13.5 years). Our results show that the three cognitive components of domain-general scientific reasoning emerge asynchronously. The development of domain-general scientific reasoning begins with the ability to handle unambiguous data, progresses to the interpretation of ambiguous data, and leads to a flexible adaptation of hypotheses according to the sufficiency of evidence. When children understand the relation between the level of ambiguity of evidence and the level of confidence in hypotheses, the ability to differentiate conclusive from inconclusive experiments accompanies this development. Implications of these results for designing science education concepts for young children are briefly discussed. © 2012 The British Psychological Society.
Zhang, Fan; Allen, Andrew J.; Levine, Lyle E.; ...
2015-01-01
Here, the needs both for increased experimental throughput and forin operandocharacterization of functional materials under increasingly realistic experimental conditions have emerged as major challenges across the whole of crystallography. A novel measurement scheme that allows multiplexed simultaneous measurements from multiple nearby sample volumes is presented. This new approach enables better measurement statistics or direct probing of heterogeneous structure, dynamics or elemental composition. To illustrate, the submicrometer precision that optical lithography provides has been exploited to create a multiplexed form of ultra-small-angle scattering based X-ray photon correlation spectroscopy (USAXS-XPCS) using micro-slit arrays fabricated by photolithography. Multiplexed USAXS-XPCS is applied to followmore » the equilibrium dynamics of a simple colloidal suspension. While the dependence of the relaxation time on momentum transfer, and its relationship with the diffusion constant and the static structure factor, follow previous findings, this measurements-in-parallel approach reduces the statistical uncertainties of this photon-starved technique to below those associated with the instrument resolution. More importantly, we note the potential of the multiplexed scheme to elucidate the response of different components of a heterogeneous sample underidenticalexperimental conditions in simultaneous measurements. Lastly, in the context of the X-ray synchrotron community, this scheme is, in principle, applicable to all in-line synchrotron techniques. Indeed, it has the potential to open a new paradigm for in operando characterization of heterogeneous functional materials, a situation that will be even further enhanced by the ongoing development of multi-bend achromat storage ring designs as the next evolution of large-scale X-ray synchrotron facilities around the world.« less
Spray vaccination: a method for the immunization of fish
Gould, R.W.; O'Leary, P. J.; Garrison, R. L.; Rohovec, J.S.; Fryer, J.L.
1978-01-01
The use of immunizing agents is emerging as a complement to other methods of disease control and has been used successfully both experimentally and commercially (FRYER et al., 1977). Two problems exist in the development of fish vaccines: first, to provide efficacious preparations; and second, to provide economic methods for mass vaccination. Vaccines for fish have been delivered by several methods to include: parenteral injection; orally, through incorporation of vaccines into the animal's diet; hyperosmotic infiltration, by placing fish in a hyperosmotic solution followed by a vaccine bath; direct immersion into vaccine suspensions; or by direct addition of vaccine to water in which fish are held (CORBEL, 1975; AMEND, 1976; AMEND and FENDER, 1976; SCHACTE, 1976; ANTIPA and AMEND, 1977; CROY and AMEND, 1977; FRYER, et al., 1977). Each of these techniques has its inherent advantages and disadvantages. Although intraperitoneal injection appears to be most effective, this method is time consuming and stresses the fish being vaccinated. Oral administration is perhaps the most desirable method of vaccine delivery, but in some cases has not provided high levels of resistance (GUNNELS, et al., 1976). Hyperosmotic infil tration and direct immersion are used to vac cinate small fish but may not be economical with larger animals. Addition of vaccine to water has been used experimentally only with an attenuated viral vaccine (FRYER et al., 1976). This report describes another method for mass immunization of fish. A bacterin against Vibrio anguillarum was administered by spraying fish with antigens prepared by selected methods. This technique provided a fast efficacious means of administering vibrio bacterin.
Osterhaus, Christopher; Koerber, Susanne; Sodian, Beate
2017-03-01
Do social cognition and epistemological understanding promote elementary school children's experimentation skills? To investigate this question, 402 children (ages 8, 9, and 10) in 2nd, 3rd, and 4th grades were assessed for their experimentation skills, social cognition (advanced theory of mind [AToM]), epistemological understanding (understanding the nature of science), and general information-processing skills (inhibition, intelligence, and language abilities) in a whole-class testing procedure. A multiple indicators multiple causes model revealed a significant influence of social cognition (AToM) on epistemological understanding, and a McNemar test suggested that children's development of AToM is an important precursor for the emergence of an advanced, mature epistemological understanding. Children's epistemological understanding, in turn, predicted their experimentation skills. Importantly, this relation was independent of the common influences of general information processing. Significant relations between experimentation skills and inhibition, and between epistemological understanding, intelligence, and language abilities emerged, suggesting that general information processing contributes to the conceptual development that is involved in scientific thinking. The model of scientific thinking that was tested in this study (social cognition and epistemological understanding promote experimentation skills) fitted the data significantly better than 2 alternative models, which assumed nonspecific, equally strong relations between all constructs under investigation. Our results support the conclusion that social cognition plays a foundational role in the emergence of children's epistemological understanding, which in turn is closely related to the development of experimentation skills. Our findings have significant implications for the teaching of scientific thinking in elementary school and they stress the importance of children's epistemological understanding in scientific-thinking processes. (PsycINFO Database Record (c) 2017 APA, all rights reserved).
The measure and significance of Bateman's principles
Collet, Julie M.; Dean, Rebecca F.; Worley, Kirsty; Richardson, David S.; Pizzari, Tommaso
2014-01-01
Bateman's principles explain sex roles and sexual dimorphism through sex-specific variance in mating success, reproductive success and their relationships within sexes (Bateman gradients). Empirical tests of these principles, however, have come under intense scrutiny. Here, we experimentally show that in replicate groups of red junglefowl, Gallus gallus, mating and reproductive successes were more variable in males than in females, resulting in a steeper male Bateman gradient, consistent with Bateman's principles. However, we use novel quantitative techniques to reveal that current methods typically overestimate Bateman's principles because they (i) infer mating success indirectly from offspring parentage, and thus miss matings that fail to result in fertilization, and (ii) measure Bateman gradients through the univariate regression of reproductive over mating success, without considering the substantial influence of other components of male reproductive success, namely female fecundity and paternity share. We also find a significant female Bateman gradient but show that this likely emerges as spurious consequences of male preference for fecund females, emphasizing the need for experimental approaches to establish the causal relationship between reproductive and mating success. While providing qualitative support for Bateman's principles, our study demonstrates how current approaches can generate a misleading view of sex differences and roles. PMID:24648220
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kharel, P.; Herran, J.; Lukashev, P.
Recent discovery of a new class of materials, spin-gapless semiconductors (SGS), has attracted considerable attention in the last few years, primarily due to potential applications in the emerging field of spin-based electronics (spintronics). Here, we investigate structural, electronic, and magnetic properties of one potential SGS compound, MnCrVAl, using various experimental and theoretical techniques. Our calculations show that this material exhibits ≈ 0.5 eV band gap for the majority-spin states, while for the minority-spin it is nearly gapless. The calculated magnetic moment for the completely ordered structure is 2.9 μB/f.u., which is different from our experimentally measured value of almost zero.more » Here, this discrepancy is explained by the structural disorder. In particular, A2 type disorder, where Mn or Cr atoms exchange their positions with Al atoms, results in induced antiferromagnetic exchange coupling, which, at a certain level of disorder, effectively reduces the total magnetic moment to zero. This is consistent with our x-ray diffraction measurements which indicate the presence of A2 disorder in all of our samples. In addition, we also show that B2 disorder does not result in antiferromagnetic exchange coupling and therefore does not significantly reduce the total magnetic moment.« less
Amadei, Carlo Alberto; Montessori, Andrea; Kadow, Julian P; Succi, Sauro; Vecitis, Chad D
2017-04-18
Active research in nanotechnology contemplates the use of nanomaterials for environmental engineering applications. However, a primary challenge is understanding the effects of nanomaterial properties on industrial device performance and translating unique nanoscale properties to the macroscale. One emerging example consists of graphene oxide (GO) membranes for separation processes. Thus, here we investigate how individual GO properties can impact GO membrane characteristics and water permeability. GO chemistry and morphology were controlled with easy-to-implement photoreduction and sonication techniques and were quantitatively correlated, offering a valuable tool for accelerating characterization. Chemical GO modification allows for fine control of GO oxidation state, allowing control of GO architectural laminate (GOAL) spacing and permeability. Water permeability was measured for eight GOALs characterized by different GOAL chemistry and morphology and indicates that GOAL nanochannel height dictates water transport. The experimental outputs were corroborated with mesoscale water transport simulations of relatively large domains (thousands of square nanometers) and indicate a no-slip Darcy-like behavior inside the GOAL nanochannels. The experimental and simulation evidence presented in this study helps create a clearer picture of water transport in GOAL and can be used to rationally design more effective and efficient GO membranes.
Software-aided automatic laser optoporation and transfection of cells
Georg Breunig, Hans; Uchugonova, Aisada; Batista, Ana; König, Karsten
2015-01-01
Optoporation, the permeabilization of a cell membrane by laser pulses, has emerged as a powerful non-invasive and highly efficient technique to induce transfection of cells. However, the usual tedious manual targeting of individual cells significantly limits the addressable cell number. To overcome this limitation, we present an experimental setup with custom-made software control, for computer-automated cell optoporation. The software evaluates the image contrast of cell contours, automatically designates cell locations for laser illumination, centres those locations in the laser focus, and executes the illumination. By software-controlled meandering of the sample stage, in principle all cells in a typical cell culture dish can be targeted without further user interaction. The automation allows for a significant increase in the number of treatable cells compared to a manual approach. For a laser illumination duration of 100 ms, 7-8 positions on different cells can be targeted every second inside the area of the microscope field of view. The experimental capabilities of the setup are illustrated in experiments with Chinese hamster ovary cells. Furthermore, the influence of laser power is discussed, with mention on post-treatment cell survival and optoporation-efficiency rates. PMID:26053047
Zhang, Xiaoming; Liu, Chang; Chen, Jinxiang; Zhang, Jiandong; Gu, Yueyan; Zhao, Yong
2016-12-01
The influence mechanism of processing holes on the flexural properties of fully integrated honeycomb plates (FIHPs) was analyzed using the finite element method (FEM), and the results were compared with experimental data, yielding the following findings: 1) Processing holes under tensile stress have a significant impact on the mechanical properties of FIHPs, which is particularly obvious when initial imperfections are formed during sample preparation. 2) A proposed design technique based on changing the shape of the processing holes from circular to elliptical effectively reduces the stress concentration when such holes must exist in skin or components under tension, and this method motivates a design concept for experimental tests of FIHPs bearing dynamic or fatigue loads. 3) The flexural failure modes of FIHPs were confirmed via FEM analysis, and the mechanism by which trabeculae in FIHPs can effectively prevent cracks from emerging and cause cracks to develop along certain paths was ascertained. Therefore, this paper provides a theoretical basis for the design of processing holes in bionic honeycomb plates and other similar components in practical engineering applications. Copyright © 2016 Elsevier B.V. All rights reserved.
The 20th Annual Prostate Cancer Foundation Scientific Retreat report.
Miyahira, Andrea K; Simons, Jonathan W; Soule, Howard R
2014-06-01
The 20th Annual Prostate Cancer Foundation (PCF) Scientific Retreat was held from October 24 to 26, 2013, in National Harbor, Maryland. This event is held annually for the purpose of convening a diverse group of leading experimental and clinical researchers from academia, industry, and government to present and discuss critical and emerging topics relevant to prostate cancer (PCa) biology, and the diagnosis, prognosis, and treatment of PCa patients, with a focus on results that will lend to treatments for the most life-threatening stages of this disease. The themes that were highlighted at this year's event included: (i) mechanisms of PCa initiation and progression: cellular origins, neurons and neuroendocrine PCa, long non-coding RNAs, epigenetics, tumor cell metabolism, tumor-immune interactions, and novel molecular mechanisms; (ii) advancements in precision medicine strategies and predictive biomarkers of progression, survival, and drug sensitivities, including the analysis of circulating tumor cells and cell-free tumor DNA-new methods for liquid biopsies; (iii) new treatments including epigenomic therapy and immunotherapy, discovery of new treatment targets, and defining and targeting mechanisms of resistance to androgen-axis therapeutics; and (iv) new experimental and clinical epidemiology methods and techniques, including PCa population studies using patho-epidemiology. © 2014 Wiley Periodicals, Inc.
Mapping the exciton diffusion in semiconductor nanocrystal solids.
Kholmicheva, Natalia; Moroz, Pavel; Bastola, Ebin; Razgoniaeva, Natalia; Bocanegra, Jesus; Shaughnessy, Martin; Porach, Zack; Khon, Dmitriy; Zamkov, Mikhail
2015-03-24
Colloidal nanocrystal solids represent an emerging class of functional materials that hold strong promise for device applications. The macroscopic properties of these disordered assemblies are determined by complex trajectories of exciton diffusion processes, which are still poorly understood. Owing to the lack of theoretical insight, experimental strategies for probing the exciton dynamics in quantum dot solids are in great demand. Here, we develop an experimental technique for mapping the motion of excitons in semiconductor nanocrystal films with a subdiffraction spatial sensitivity and a picosecond temporal resolution. This was accomplished by doping PbS nanocrystal solids with metal nanoparticles that force the exciton dissociation at known distances from their birth. The optical signature of the exciton motion was then inferred from the changes in the emission lifetime, which was mapped to the location of exciton quenching sites. By correlating the metal-metal interparticle distance in the film with corresponding changes in the emission lifetime, we could obtain important transport characteristics, including the exciton diffusion length, the number of predissociation hops, the rate of interparticle energy transfer, and the exciton diffusivity. The benefits of this approach to device applications were demonstrated through the use of two representative film morphologies featuring weak and strong interparticle coupling.
La mécanique des fluides à la Sorbonne entre les deux guerres
NASA Astrophysics Data System (ADS)
Fontanon, Claudine
2017-08-01
World War I opened the way to a restructuring of research in the field of aviation sciences in France as abroad. Technical advances were made possible under the impulse of a new science: aerodynamics, notably owing to Gustave Eiffel's works. Nevertheless, the experimental approach that most marked this foundational period was replaced, after the Great War, with a much more theoretical approach of aerodynamic phenomena. And it is under the name ;fluid mechanics; that both theoretical and experimental approaches were gathered together to constitute, with classical hydrodynamics, the basis of teaching and university research at the Faculty of Sciences in Paris. The patronage era that had anchored aeronautical teaching and research to the Faculty of Sciences in Paris was succeeded by an era when the government authorities directly intervened to institutionalize fluid mechanics and orientate it toward applications to aviation. In this article, we will analyse the steps and modalities of the emergence of this science, with the aim to determine how much the scientific policy deployed between the two wars by the public authorities influenced the evolution and the progress of aeronautical techniques, and met the expectations of its promoters.
NASA Technical Reports Server (NTRS)
Griffith, Wayland C.
1989-01-01
Possible experimental facilities appropriate to a university environment that could make meaningful contributions to the solution of problems in hypersonic aerodynamics are investigated. Needs for the National Aerospace Plane and interplanetary flights with atmospheric aerobraking are used to scope the problem. Relevant events of the past two decades in universities and at the national laboratories are examined for their implications regarding both problems and prospects. Most striking is the emergence of computational fluid dynamics, which is viewed here as an equal partner with laboratory experimentation and flight test in relating theory with reality. Also significant are major advances in instrumentation and data processing methods, especially optical techniques. The direction of the study was guided by the concept of a companion program, i.e., the university effort should complement a major area of endeavor at NASA-Langley. Through this, both faculty and student participants gain a natural and effective working relationship. Existing and proposed major hypersonic aerodynamic facilities in industry and at the national laboratories are examined by type; hypersonic wind tunnels, arc-heated tunnels, shock tubes and tunnels, and ballistic ranges. Of these, the free piston tunnel and shock tube/tunnel are most appropriate for a university.
A Course in Heterogeneous Catalysis: Principles, Practice, and Modern Experimental Techniques.
ERIC Educational Resources Information Center
Wolf, Eduardo E.
1981-01-01
Outlines a multidisciplinary course which comprises fundamental, practical, and experimental aspects of heterogeneous catalysis. The course structure is a combination of lectures and demonstrations dealing with the use of spectroscopic techniques for surface analysis. (SK)
Experimental Study of Residual Stresses in Rail by Moire Interferometry
DOT National Transportation Integrated Search
1993-09-01
The residual stresses in rails produced by rolling cycles are studied experimentally by moire interferometry. The dissection technique is adopted for this investigation. The basic principle of the dissection technique is that the residual stress is r...
Spectral Analysis and Experimental Modeling of Ice Accretion Roughness
NASA Technical Reports Server (NTRS)
Orr, D. J.; Breuer, K. S.; Torres, B. E.; Hansman, R. J., Jr.
1996-01-01
A self-consistent scheme for relating wind tunnel ice accretion roughness to the resulting enhancement of heat transfer is described. First, a spectral technique of quantitative analysis of early ice roughness images is reviewed. The image processing scheme uses a spectral estimation technique (SET) which extracts physically descriptive parameters by comparing scan lines from the experimentally-obtained accretion images to a prescribed test function. Analysis using this technique for both streamwise and spanwise directions of data from the NASA Lewis Icing Research Tunnel (IRT) are presented. An experimental technique is then presented for constructing physical roughness models suitable for wind tunnel testing that match the SET parameters extracted from the IRT images. The icing castings and modeled roughness are tested for enhancement of boundary layer heat transfer using infrared techniques in a "dry" wind tunnel.
Sahoo, Pravas Ranjan; Sethy, Kamadev; Mohapatra, Swagat; Panda, Debasis
2016-05-01
India being a developing country mainly depends on livestock sector for its economy. However, nowadays, there is emergence and reemergence of more transboundary animal diseases. The existing diagnostic techniques are not so quick and with less specificity. To reduce the economy loss, there should be a development of rapid, reliable, robust diagnostic technique, which can work with high degree of sensitivity and specificity. Loop mediated isothermal amplification assay is a rapid gene amplification technique that amplifies nucleic acid under an isothermal condition with a set of designed primers spanning eight distinct sequences of the target. This assay can be used as an emerging powerful, innovative gene amplification diagnostic tool against various pathogens of livestock diseases. This review is to highlight the basic concept and methodology of this assay in livestock disease.
NASA Technical Reports Server (NTRS)
Powers, E. J.; Kim, Y. C.; Hong, J. Y.; Roth, J. R.; Krawczonek, W. M.
1978-01-01
A diagnostic, based on fast Fourier-transform spectral analysis techniques, that provides experimental insight into the relationship between the experimentally observable spectral characteristics of the fluctuations and the fluctuation-induced plasma transport is described. The model upon which the diagnostic technique is based and its experimental implementation is discussed. Some characteristic results obtained during the course of an experimental study of fluctuation-induced transport in the electric field dominated NASA Lewis bumpy torus plasma are presented.
Variation and Defect Tolerance for Nano Crossbars
NASA Astrophysics Data System (ADS)
Tunc, Cihan
With the extreme shrinking in CMOS technology, quantum effects and manufacturing issues are getting more crucial. Hence, additional shrinking in CMOS feature size seems becoming more challenging, difficult, and costly. On the other hand, emerging nanotechnology has attracted many researchers since additional scaling down has been demonstrated by manufacturing nanowires, Carbon nanotubes as well as molecular switches using bottom-up manufacturing techniques. In addition to the progress in manufacturing, developments in architecture show that emerging nanoelectronic devices will be promising for the future system designs. Using nano crossbars, which are composed of two sets of perpendicular nanowires with programmable intersections, it is possible to implement logic functions. In addition, nano crossbars present some important features as regularity, reprogrammability, and interchangeability. Combining these features, researchers have presented different effective architectures. Although bottom-up nanofabrication can greatly reduce manufacturing costs, due to low controllability in the manufacturing process, some critical issues occur. Bottom- up nanofabrication process results in high variation compared to conventional top- down lithography used in CMOS technology. In addition, an increased failure rate is expected. Variation and defect tolerance methods used for conventional CMOS technology seem inadequate for adapting to emerging nano technology because the variation and the defect rate for emerging nano technology is much more than current CMOS technology. Therefore, variations and defect tolerance methods for emerging nano technology are necessary for a successful transition. In this work, in order to tolerate variations for crossbars, we introduce a framework that is established based on reprogrammability and interchangeability features of nano crossbars. This framework is shown to be applicable for both FET-based and diode-based nano crossbars. We present a characterization testing method which requires minimal number of test vectors. We formulate the variation optimization problem using Simulated Annealing with different optimization goals. Furthermore, we extend the framework for defect tolerance. Experimental results and comparison of proposed framework with exhaustive methods confirm its effectiveness for both variation and defect tolerance.
Computational Prediction of Metabolism: Sites, Products, SAR, P450 Enzyme Dynamics, and Mechanisms
2012-01-01
Metabolism of xenobiotics remains a central challenge for the discovery and development of drugs, cosmetics, nutritional supplements, and agrochemicals. Metabolic transformations are frequently related to the incidence of toxic effects that may result from the emergence of reactive species, the systemic accumulation of metabolites, or by induction of metabolic pathways. Experimental investigation of the metabolism of small organic molecules is particularly resource demanding; hence, computational methods are of considerable interest to complement experimental approaches. This review provides a broad overview of structure- and ligand-based computational methods for the prediction of xenobiotic metabolism. Current computational approaches to address xenobiotic metabolism are discussed from three major perspectives: (i) prediction of sites of metabolism (SOMs), (ii) elucidation of potential metabolites and their chemical structures, and (iii) prediction of direct and indirect effects of xenobiotics on metabolizing enzymes, where the focus is on the cytochrome P450 (CYP) superfamily of enzymes, the cardinal xenobiotics metabolizing enzymes. For each of these domains, a variety of approaches and their applications are systematically reviewed, including expert systems, data mining approaches, quantitative structure–activity relationships (QSARs), and machine learning-based methods, pharmacophore-based algorithms, shape-focused techniques, molecular interaction fields (MIFs), reactivity-focused techniques, protein–ligand docking, molecular dynamics (MD) simulations, and combinations of methods. Predictive metabolism is a developing area, and there is still enormous potential for improvement. However, it is clear that the combination of rapidly increasing amounts of available ligand- and structure-related experimental data (in particular, quantitative data) with novel and diverse simulation and modeling approaches is accelerating the development of effective tools for prediction of in vivo metabolism, which is reflected by the diverse and comprehensive data sources and methods for metabolism prediction reviewed here. This review attempts to survey the range and scope of computational methods applied to metabolism prediction and also to compare and contrast their applicability and performance. PMID:22339582
Nanomaterial-Enabled Neural Stimulation
Wang, Yongchen; Guo, Liang
2016-01-01
Neural stimulation is a critical technique in treating neurological diseases and investigating brain functions. Traditional electrical stimulation uses electrodes to directly create intervening electric fields in the immediate vicinity of neural tissues. Second-generation stimulation techniques directly use light, magnetic fields or ultrasound in a non-contact manner. An emerging generation of non- or minimally invasive neural stimulation techniques is enabled by nanotechnology to achieve a high spatial resolution and cell-type specificity. In these techniques, a nanomaterial converts a remotely transmitted primary stimulus such as a light, magnetic or ultrasonic signal to a localized secondary stimulus such as an electric field or heat to stimulate neurons. The ease of surface modification and bio-conjugation of nanomaterials facilitates cell-type-specific targeting, designated placement and highly localized membrane activation. This review focuses on nanomaterial-enabled neural stimulation techniques primarily involving opto-electric, opto-thermal, magneto-electric, magneto-thermal and acousto-electric transduction mechanisms. Stimulation techniques based on other possible transduction schemes and general consideration for these emerging neurotechnologies are also discussed. PMID:27013938
In situ health monitoring for bogie systems of CRH380 train on Beijing-Shanghai high-speed railway
NASA Astrophysics Data System (ADS)
Hong, Ming; Wang, Qiang; Su, Zhongqing; Cheng, Li
2014-04-01
Based on the authors' research efforts over the years, an in situ structural health monitoring (SHM) technique taking advantage of guided elastic waves has been developed and deployed via an online diagnosis system. The technique and the system were recently implemented on China's latest high-speed train (CRH380CL) operated on Beijing-Shanghai High-Speed Railway. The system incorporated modularized components including active sensor network, active wave generation, multi-channel data acquisition, signal processing, data fusion, and results presentation. The sensor network, inspired by a new concept—"decentralized standard sensing", was integrated into the bogie frames during the final assembly of CRH380CL, to generate and acquire bogie-guided ultrasonic waves, from which a wide array of signal features were extracted. Fusion of signal features through a diagnostic imaging algorithm led to a graphic illustration of the overall health state of the bogie in a real-time and intuitive manner. The in situ experimentation covered a variety of high-speed train operation events including startup, acceleration/deceleration, full-speed operation (300 km/h), emergency braking, track change, as well as full stop. Mock-up damage affixed to the bogie was identified quantitatively and visualized in images. This in situ testing has demonstrated the feasibility, effectiveness, sensitivity, and reliability of the developed SHM technique and the system towards real-world applications.
Prospects for therapeutic mitochondrial transplantation.
Gollihue, Jenna L; Rabchevsky, Alexander G
2017-07-01
Mitochondrial dysfunction has been implicated in a multitude of diseases and pathological conditions- the organelles that are essential for life can also be major players in contributing to cell death and disease. Because mitochondria are so well established in our existence, being present in all cell types except for red blood cells and having the responsibility of providing most of our energy needs for survival, then dysfunctional mitochondria can elicit devastating cellular pathologies that can be widespread across the entire organism. As such, the field of "mitochondrial medicine" is emerging in which disease states are being targeted therapeutically at the level of the mitochondrion, including specific antioxidants, bioenergetic substrate additions, and membrane uncoupling agents. New and compelling research investigating novel techniques for mitochondrial transplantation to replace damaged or dysfunctional mitochondria with exogenous healthy mitochondria has shown promising results, including tissue sparing accompanied by increased energy production and decreased oxidative damage. Various experimental techniques have been attempted and each has been challenged to accomplish successful transplantation. The purpose of this review is to present the history of mitochondrial transplantation, the different techniques used for both in vitro and in vivo delivery, along with caveats and pitfalls that have been discovered along the way. Results from such pioneering studies are promising and could be the next big wave of "mitochondrial medicine" once technical hurdles are overcome. Copyright © 2017 Elsevier B.V. and Mitochondria Research Society. All rights reserved.
Mapping Topological Magnetization and Magnetic Skyrmions
NASA Astrophysics Data System (ADS)
Chess, Jordan J.
A 2014 study by the US Department of Energy conducted at Lawrence Berkeley National Laboratory estimated that U.S. data centers consumed 70 billion kWh of electricity. This represents about 1.8% of the total U.S. electricity consumption. Putting this in perspective 70 billion kWh of electricity is the equivalent of roughly 8 big nuclear reactors, or around double the nation's solar panel output. Developing new memory technologies capable of reducing this power consumption would be greatly beneficial as our demand for connectivity increases in the future. One newly emerging candidate for an information carrier in low power memory devices is the magnetic skyrmion. This magnetic texture is characterized by its specific non-trivial topology, giving it particle-like characteristics. Recent experimental work has shown that these skyrmions can be stabilized at room temperature and moved with extremely low electrical current densities. This rapidly developing field requires new measurement techniques capable of determining the topology of these textures at greater speed than previous approaches. In this dissertation, I give a brief introduction to the magnetic structures found in Fe/Gd multilayered systems. I then present newly developed techniques that streamline the analysis of Lorentz Transmission Electron Microscopy (LTEM) data. These techniques are then applied to further the understanding of the magnetic properties of these Fe/Gd based multilayered systems. This dissertation includes previously published and unpublished co-authored material.
Prediction of mortality after radical cystectomy for bladder cancer by machine learning techniques.
Wang, Guanjin; Lam, Kin-Man; Deng, Zhaohong; Choi, Kup-Sze
2015-08-01
Bladder cancer is a common cancer in genitourinary malignancy. For muscle invasive bladder cancer, surgical removal of the bladder, i.e. radical cystectomy, is in general the definitive treatment which, unfortunately, carries significant morbidities and mortalities. Accurate prediction of the mortality of radical cystectomy is therefore needed. Statistical methods have conventionally been used for this purpose, despite the complex interactions of high-dimensional medical data. Machine learning has emerged as a promising technique for handling high-dimensional data, with increasing application in clinical decision support, e.g. cancer prediction and prognosis. Its ability to reveal the hidden nonlinear interactions and interpretable rules between dependent and independent variables is favorable for constructing models of effective generalization performance. In this paper, seven machine learning methods are utilized to predict the 5-year mortality of radical cystectomy, including back-propagation neural network (BPN), radial basis function (RBFN), extreme learning machine (ELM), regularized ELM (RELM), support vector machine (SVM), naive Bayes (NB) classifier and k-nearest neighbour (KNN), on a clinicopathological dataset of 117 patients of the urology unit of a hospital in Hong Kong. The experimental results indicate that RELM achieved the highest average prediction accuracy of 0.8 at a fast learning speed. The research findings demonstrate the potential of applying machine learning techniques to support clinical decision making. Copyright © 2015 Elsevier Ltd. All rights reserved.
In situ electrical and thermal monitoring of printed electronics by two-photon mapping.
Pastorelli, Francesco; Accanto, Nicolò; Jørgensen, Mikkel; van Hulst, Niek F; Krebs, Frederik C
2017-06-19
Printed electronics is emerging as a new, large scale and cost effective technology that will be disruptive in fields such as energy harvesting, consumer electronics and medical sensors. The performance of printed electronic devices relies principally on the carrier mobility and molecular packing of the polymer semiconductor material. Unfortunately, the analysis of such materials is generally performed with destructive techniques, which are hard to make compatible with in situ measurements, and pose a great obstacle for the mass production of printed electronics devices. A rapid, in situ, non-destructive and low-cost testing method is needed. In this study, we demonstrate that nonlinear optical microscopy is a promising technique to achieve this goal. Using ultrashort laser pulses we stimulate two-photon absorption in a roll coated polymer semiconductor and map the resulting two-photon induced photoluminescence and second harmonic response. We show that, in our experimental conditions, it is possible to relate the total amount of photoluminescence detected to important material properties such as the charge carrier density and the molecular packing of the printed polymer material, all with a spatial resolution of 400 nm. Importantly, this technique can be extended to the real time mapping of the polymer semiconductor film, even during the printing process, in which the high printing speed poses the need for equally high acquisition rates.
Davis, Jordan P; Dumas, Tara M; Briley, Daniel A; Sussman, Steve
2018-04-01
Much debate exists surrounding Arnett's theory of emerging adulthood in terms of its breadth and application. Researchers have attempted to capture dimensions of emerging adulthood (eg, experimentation, negativity/instability, other-focus, self-focus, and feeling in-between) through self report assessment, using variations of the Inventory of the Dimensions of Emerging Adulthood or IDEA. Results from studies investigating this relationship have been mixed. We conducted a meta-analysis on the association between substance use and the IDEA. Data were extracted to calculate correlational associations with substance use as well as typical moderators found in the literature. Twelve studies were meta-analyzed. We found small associations (range: ρ = -.03 to .15; d = .06 to 30) between the IDEA scores and substance use. We found higher severity (dependence diagnosis) of participants yielded larger associations across all dimensions (ρ = .16), and proportion of college students to be a subscale-specific moderator (experimentation, negativity/instability, other-focus, self-focus, and feeling in-between). Alcohol use outcomes also provided larger subscale-specific associations (experimentation, negativity/instability, other-focus, self-focus). The dimensions of emerging adulthood may be less effective in predicting substance use among non-college samples and those studies focusing on drug use. Further research should prioritize exploring variation in the transition to emerging adulthood among non-college samples and the longitudinal associations between IDEA and substance use. Important contributions include the modest association between IDEA and substance use as well as specific participant characteristics that amplify or mitigate the association between IDEA and substance use. (Am J Addict 2018;27:166-176). © 2018 American Academy of Addiction Psychiatry.
Cavitation nucleation in gelatin: Experiment and mechanism.
Kang, Wonmo; Adnan, Ashfaq; O'Shaughnessy, Thomas; Bagchi, Amit
2018-02-01
Dynamic cavitation in soft materials is becoming increasingly relevant due to emerging medical implications such as the potential of cavitation-induced brain injury or cavitation created by therapeutic medical devices. However, the current understanding of dynamic cavitation in soft materials is still very limited, mainly due to lack of robust experimental techniques. To experimentally characterize cavitation nucleation under dynamic loading, we utilize a recently developed experimental instrument, the integrated drop tower system. This technique allows quantitative measurements of the critical acceleration (a cr ) that corresponds to cavitation nucleation while concurrently visualizing time evolution of cavitation. Our experimental results reveal that a cr increases with increasing concentration of gelatin in pure water. Interestingly, we have observed the distinctive transition from a sharp increase (pure water to 1% gelatin) to a much slower rate of increase (∼10× slower) between 1% and 7.5% gelatin. Theoretical cavitation criterion predicts the general trend of increasing a cr , but fails to explain the transition rates. As a likely mechanism, we consider concentration-dependent material properties and non-spherical cavitation nucleation sites, represented by pre-existing bubbles in gels, due to possible interplay between gelatin molecules and nucleation sites. This analysis shows that cavitation nucleation is very sensitive to the initial configuration of a bubble, i.e., a non-spherical bubble can significantly increase a cr . This conclusion matches well with the experimentally observed liquid-to-gel transition in the critical acceleration for cavitation nucleation. From a medical standpoint, understanding dynamic cavitation within soft materials, i.e., tissues, is important as there are both potential injury implications (blast-induced cavitation within the brain) as well as treatments utilizing the phenomena (lithotripsy). In this regard, the main results of the present work are (1) quantitative characterization of cavitation nucleation in gelatin samples as a function of gel concentration utilizing well-controlled mechanical impacts and (2) mechanistic understanding of complex coupling between cavitation and liquid-/solid-like material properties of gel. The new capabilities of testing soft gels, which can be tuned to mimic material properties of target organs, at high loading rate conditions and accurately predicting their cavitation behavior are an important step towards developing reliable cavitation criteria in the scope of their biomedical applications. Copyright © 2017 Acta Materialia Inc. All rights reserved.
Energy transformation, transfer, and release dynamics in high speed turbulent flows
2017-03-01
experimental techniques developed allowed non -intrusive measurement of convecting velocity fields in supersonic flows and used for validation of LES of...by the absence of (near-)normal shocks that normal injection generates. New experimental techniques were developed that allowed the non -intrusive...and was comprised of several parts in which significant accomplishments were made: 1. An experimental effort focusing on investigations in: a
A refined electrofishing technique for collecting Silver Carp: Implications for management
Bouska, Wesley W.; Glover, David C.; Bouska, Kristen; Garvey, James E.
2017-01-01
Detecting nuisance species at low abundance or in newly established areas is critical to developing pest management strategies. Due to their sensitivity to disturbance and erratic jumping behavior, Silver Carp Hypophthalmichthys molitrix can be difficult to collect with traditional sampling methods. We compared catch per unit effort (CPUE) of all species from a Long Term Resource Monitoring (LTRM) electrofishing protocol to an experimental electrofishing technique designed to minimize Silver Carp evasion through tactical boat maneuvering and selective application of power. Differences in CPUE between electrofishing methods were detected for 2 of 41 species collected across 2 years of sampling at 20 sites along the Illinois River. The mean catch rate of Silver Carp using the experimental technique was 2.2 times the mean catch rate of the LTRM electrofishing technique; the increased capture efficiency at low relative abundance emphasizes the utility of this method for early detection. The experimental electrofishing also collected slightly larger Silver Carp (mean: 510.7 mm TL versus 495.2 mm TL), and nearly four times as many Silver Carp independently jumped into the boat during experimental transects. Novel sampling approaches, such as the experimental electrofishing technique used in this study, should be considered to increase probability of detection for aquatic nuisance species.
Ultrasound excited thermography: an efficient tool for the characterization of vertical cracks
NASA Astrophysics Data System (ADS)
Mendioroz, A.; Celorrio, R.; Salazar, A.
2017-11-01
Ultrasound excited thermography has gained a renewed interest in the last two decades as a nondestructive testing technique aimed at detecting and characterizing surface breaking and shallow subsurface discontinuities. It is based on measurement of the IR radiation emitted by the specimen surface to detect temperature rises produced by the heating of defects under high amplitude ultrasound excitation and is primarily addressed to flaws with contacting faces, such as kissing cracks or tight delaminations. The simplicity of application and the ability to detect small cracks in challenging media makes it an attractive emerging technology, which is still in a development stage. However, it has proven to provide an opportunity for the quantitative characterization of defects, mainly of vertical cracks. In this review, we present the principles of the technique and the different experimental implementations, we put it in context with other nondestructive tests and we summarize the work done in order to improve defect detectability and test reliability, with the final goal of determining the probability of detection. Then we review the contributions aimed at characterizing vertical cracks, i.e. retrieving the geometry and location of the crack from surface temperature data, generated by ultrasonic excitation.
Real-time imaging of subarachnoid hemorrhage in piglets with electrical impedance tomography.
Dai, Meng; Wang, Liang; Xu, Canhua; Li, Lianfeng; Gao, Guodong; Dong, Xiuzhen
2010-09-01
Subarachnoid hemorrhage (SAH) is one of the most severe medical emergencies in neurosurgery. Early detection or diagnosis would significantly reduce the rate of disability and mortality, and improve the prognosis of the patients. Although the present medical imaging techniques generally have high sensitivity to identify bleeding, the use of an additional, non-invasive imaging technique capable of continuously monitoring SAH is required to prevent contingent bleeding or re-bleeding. In this study, electrical impedance tomography (EIT) was applied to detect the onset of SAH modeled on eight piglets in real time, with the subsequent process being monitored continuously. The experimental SAH model was introduced by one-time injection of 5 ml fresh autologous arterial blood into the cisterna magna. Results showed that resistivity variations within the brain caused by the added blood could be detected using the EIT method and may be associated not only with the resistivity difference among brain tissues, but also with variations of cerebrospinal fluid dynamics. In conclusion, EIT has unique potential for use in clinical practice to provide invaluable real-time neuroimaging data for SAH after the improvement of electrode design, anisotropic realistic modeling and instrumentation.
Li, Weijie; Xu, Changhang; Ho, Siu Chun Michael; Wang, Bo; Song, Gangbing
2017-01-01
Corrosion of concrete reinforcement members has been recognized as a predominant structural deterioration mechanism for steel reinforced concrete structures. Many corrosion detection techniques have been developed for reinforced concrete structures, but a dependable one is more than desired. Acoustic emission technique and fiber optic sensing have emerged as new tools in the field of structural health monitoring. In this paper, we present the results of an experimental investigation on corrosion monitoring of a steel reinforced mortar block through combined acoustic emission and fiber Bragg grating strain measurement. Constant current was applied to the mortar block in order to induce accelerated corrosion. The monitoring process has two aspects: corrosion initiation and crack propagation. Propagation of cracks can be captured through corresponding acoustic emission whereas the mortar expansion due to the generation of corrosion products will be monitored by fiber Bragg grating strain sensors. The results demonstrate that the acoustic emission sources comes from three different types, namely, evolution of hydrogen bubbles, generation of corrosion products and crack propagation. Their corresponding properties are also discussed. The results also show a good correlation between acoustic emission activity and expansive strain measured on the specimen surface. PMID:28327510
Laser Techniques on Acoustically Levitated Droplets
NASA Astrophysics Data System (ADS)
Cannuli, Antonio; Caccamo, Maria Teresa; Castorina, Giuseppe; Colombo, Franco; Magazù, Salvatore
2018-01-01
This work reports the results of an experimental study where laser techniques are applied to acoustically levitated droplets of trehalose aqueous solutions in order to perform spectroscopic analyses as a function of concentration and to test the theoretical diameter law. The study of such systems is important in order to better understand the behaviour of trehalose-synthesizing extremophiles that live in extreme environments. In particular, it will be shown how acoustic levitation, combined with optical spectroscopic instruments allows to explore a wide concentration range and to test the validity of the diameter law as a function of levitation lag time, i.e. the D2 vs t law. On this purpose a direct diameter monitoring by a video camera and a laser pointer was first performed; then the diameter was also evaluated by an indirect measure through an OH/CH band area ratio analysis of collected Raman and Infrared spectra. It clearly emerges that D2 vs t follows a linear trend for about 20 minutes, reaching then a plateau at longer time. This result shows how trehalose is able to avoid total water evaporation, this property being essential for the surviving of organisms under extreme environmental conditions.
Li, Weijie; Xu, Changhang; Ho, Siu Chun Michael; Wang, Bo; Song, Gangbing
2017-03-22
Corrosion of concrete reinforcement members has been recognized as a predominant structural deterioration mechanism for steel reinforced concrete structures. Many corrosion detection techniques have been developed for reinforced concrete structures, but a dependable one is more than desired. Acoustic emission technique and fiber optic sensing have emerged as new tools in the field of structural health monitoring. In this paper, we present the results of an experimental investigation on corrosion monitoring of a steel reinforced mortar block through combined acoustic emission and fiber Bragg grating strain measurement. Constant current was applied to the mortar block in order to induce accelerated corrosion. The monitoring process has two aspects: corrosion initiation and crack propagation. Propagation of cracks can be captured through corresponding acoustic emission whereas the mortar expansion due to the generation of corrosion products will be monitored by fiber Bragg grating strain sensors. The results demonstrate that the acoustic emission sources comes from three different types, namely, evolution of hydrogen bubbles, generation of corrosion products and crack propagation. Their corresponding properties are also discussed. The results also show a good correlation between acoustic emission activity and expansive strain measured on the specimen surface.
Evolution of Islet Transplantation for the Last 30 Years.
Farney, Alan C; Sutherland, David E R; Opara, Emmanuel C
2016-01-01
In this article, we will review the changes that have occurred in islet transplantation at the birth of Pancreas 30 years ago. The first attempts at β-cell replacement in humans, pancreas and islet transplantation, were performed in the 1960s and 1970s. Although pancreas transplantation has been an accepted treatment for severe labile diabetes predating the emergence of the journal, allogeneic islet transplantation remains experimental. Current investigations within islet transplantation focus to improve islet function after transplantation. Improving islet viability during isolation, exploring ways to increase engraftment, and protection from the host immune system are some of the goals of these investigative efforts. The major barriers to clinical islet transplantation are shortage of human pancreas, the need for immunosuppression, and the inadequacy of the islet isolation process. It is generally accepted that islet encapsulation is an immunoisolation tool with good potential to address the first 2 of those barriers. We have therefore devoted a major part of this review to the critical factors needed to make it a clinical reality. With improved islet isolation techniques and determination of the best site of engraftment as well as improved encapsulation techniques, we hope that islet transplantation could someday achieve routine clinical use.
Fluorescent imaging of cancerous tissues for targeted surgery
Bu, Lihong; Shen, Baozhong; Cheng, Zhen
2014-01-01
To maximize tumor excision and minimize collateral damage is the primary goal of cancer surgery. Emerging molecular imaging techniques have to “image-guided surgery” developing into “molecular imaging-guided surgery”, which is termed “targeted surgery” in this review. Consequently, the precision of surgery can be advanced from tissue-scale to molecule-scale, enabling “targeted surgery” to be a component of “targeted therapy”. Evidence from numerous experimental and clinical studies has demonstrated significant benefits of fluorescent imaging in targeted surgery with preoperative molecular diagnostic screening. Fluorescent imaging can help to improve intraoperative staging and enable more radical cytoreduction, detect obscure tumor lesions in special organs, highlight tumor margins, better map lymph node metastases, and identify important normal structures intraoperatively. Though limited tissue penetration of fluorescent imaging and tumor heterogeneity are two major hurdles for current targeted surgery, multimodality imaging and multiplex imaging may provide potential solutions to overcome these issues, respectively. Moreover, though many fluorescent imaging techniques and probes have been investigated, targeted surgery remains at a proof-of-principle stage. The impact of fluorescent imaging on cancer surgery will likely be realized through persistent interdisciplinary amalgamation of research in diverse fields. PMID:25064553
MotifMark: Finding regulatory motifs in DNA sequences.
Hassanzadeh, Hamid Reza; Kolhe, Pushkar; Isbell, Charles L; Wang, May D
2017-07-01
The interaction between proteins and DNA is a key driving force in a significant number of biological processes such as transcriptional regulation, repair, recombination, splicing, and DNA modification. The identification of DNA-binding sites and the specificity of target proteins in binding to these regions are two important steps in understanding the mechanisms of these biological activities. A number of high-throughput technologies have recently emerged that try to quantify the affinity between proteins and DNA motifs. Despite their success, these technologies have their own limitations and fall short in precise characterization of motifs, and as a result, require further downstream analysis to extract useful and interpretable information from a haystack of noisy and inaccurate data. Here we propose MotifMark, a new algorithm based on graph theory and machine learning, that can find binding sites on candidate probes and rank their specificity in regard to the underlying transcription factor. We developed a pipeline to analyze experimental data derived from compact universal protein binding microarrays and benchmarked it against two of the most accurate motif search methods. Our results indicate that MotifMark can be a viable alternative technique for prediction of motif from protein binding microarrays and possibly other related high-throughput techniques.
NASA Astrophysics Data System (ADS)
Sim, Sung-Han; Spencer, Billie F., Jr.; Park, Jongwoong; Jung, Hyungjo
2012-04-01
Wireless Smart Sensor Networks (WSSNs) facilitates a new paradigm to structural identification and monitoring for civil infrastructure. Conventional monitoring systems based on wired sensors and centralized data acquisition and processing have been considered to be challenging and costly due to cabling and expensive equipment and maintenance costs. WSSNs have emerged as a technology that can overcome such difficulties, making deployment of a dense array of sensors on large civil structures both feasible and economical. However, as opposed to wired sensor networks in which centralized data acquisition and processing is common practice, WSSNs require decentralized computing algorithms to reduce data transmission due to the limitation associated with wireless communication. Thus, several system identification methods have been implemented to process sensor data and extract essential information, including Natural Excitation Technique with Eigensystem Realization Algorithm, Frequency Domain Decomposition (FDD), and Random Decrement Technique (RDT); however, Stochastic Subspace Identification (SSI) has not been fully utilized in WSSNs, while SSI has the strong potential to enhance the system identification. This study presents a decentralized system identification using SSI in WSSNs. The approach is implemented on MEMSIC's Imote2 sensor platform and experimentally verified using a 5-story shear building model.
A new solution to emulsion liquid membrane problems by non-Newtonian conversion
DOE Office of Scientific and Technical Information (OSTI.GOV)
Skelland, A.H.P.; Meng, X.
1996-02-01
Surfactant-stabilized emulsion liquid membrane processes constitute an emerging separation technology that has repeatedly been shown to be highly suited for such diverse separation processes as metal recovery or removal from dilute aqueous solutions; separations in the food industry; removal of organic bases and acids from water; and separation of hydrocarbons. Emulsion liquid membrane separation processes remain excessively vulnerable to one or more of four major problems. Difficulties lie in developing liquid membranes that combine high levels of both stability and permeability with acceptably low levels of swelling and ease of subsequent demulsification for membrane and solute recovery. This article providesmore » a new technique for simultaneously overcoming the first three problems, while identifying physical indications that the proposed solution may have little adverse effect on the fourth problem (demulsification) and may even alleviate it. Numerous benefits of optimized conversion of the membrane phase into suitable non-Newtonian form are identified, their mechanisms outlined, and experimental verifications provided. These include increased stability, retained (or enhanced) permeability, reduced swelling, increased internal phase volume, and increased stirrer speeds. The highly favorable responsiveness of both aliphatic and aromatic membranes to the new technique is demonstrated.« less
Callard, Felicity
2016-01-01
The category of panic disorder was significantly indebted to early psychopharmacological experiments (in the late 1950s and early 1960s) by the psychiatrist Donald Klein, in collaboration with Max Fink. Klein's technique of "psychopharmacological dissection" underpinned his transformation of clinical accounts of anxiety and was central in effecting the shift from agoraphobic anxiety (with its spatial imaginary of city squares and streets) to panic. This technique disaggregated the previously unitary affect of anxiety-as advanced in psychoanalytic accounts-into two physiological and phenomenological kinds. "Psychopharmacological dissection" depended on particular modes of clinical observation to assess drug action and to interpret patient behavior. The "intimate geographies" out of which panic disorder emerged comprised both the socio-spatial dynamics of observation on the psychiatric ward and Klein's use of John Bowlby's model of separation anxiety-as it played out between the dyad of infant and mother-to interpret his adult patients' affectively disordered behavior. This essay, in offering a historical geography of mid-twentieth-century anxiety and panic, emphasizes the importance of socio-spatial setting in understanding how clinical and scientific experimentation opens up new ways in which affects can be expressed, shaped, observed, and understood.
Brillouin light scattering studies of the mechanical properties of ultrathin low-k dielectric films
NASA Astrophysics Data System (ADS)
Link, A.; Sooryakumar, R.; Bandhu, R. S.; Antonelli, G. A.
2006-07-01
In an effort to reduce RC time delays that accompany decreasing feature sizes, low-k dielectric films are rapidly emerging as potential replacements for silicon dioxide (SiO2) at the interconnect level in integrated circuits. The main challenge in low-k materials is their substantially weaker mechanical properties that accompany the increasing pore volume content needed to reduce k. We show that Brillouin light scattering is an excellent nondestructive technique to monitor and characterize the mechanical properties of these porous films at thicknesses well below 200nm that are pertinent to present applications. Observation of longitudinal and transverse standing wave acoustic resonances and the dispersion that accompany their transformation into traveling waves with finite in-plane wave vectors provides for a direct measure of the principal elastic constants that completely characterize the mechanical properties of these ultrathin films. The mode amplitudes of the standing waves, their variation within the film, and the calculated Brillouin intensities account for most aspects of the spectra. We further show that the values obtained by this method agree well with other experimental techniques such as nanoindentation and picosecond laser ultrasonics.
Design and Manufacturing of Desalination System Powered by Solar Energy Using CDI Technique
NASA Astrophysics Data System (ADS)
Rostami, Mohammad Sajjad; Khashehchi, Morteza; Pipelzadeh, Ehsan
2017-11-01
Capacitive deionization (CDI) is an emerging energy efficient, low pressure and low capital intensive desalination process where ions are separated by a pure electrostatic force imposed by a small bias potential as low as 1 V That funded by an external Renewable (Solar) power supply to materials with high specific surface area. The main objective of this configuration is to separate the cation and anions on oppositely charged electrodes. One of the key parameters for commercial realization of CDI is the salt adsorption capacity of the electrodes. State-of-the-art electrode materials are based on porous activated carbon particles or carbon aerogels. Various electrode materials have been developed in the past, which have suffered from instability and lack of performance. Preliminary experimental results using carbon black, graphite powder, graphene ∖ graphite ∖ PTFE (Active ∖ Conductive ∖ binder) show that the graphene reduced via urea method is a suitable method to develop CDI electrode materials. Although some progress has been made, production of efficient and stable carbon based electrode materials for large scale desalination has not been fully realized. A new desalination technique using capacitive deionization.
Extracorporeal CO2 removal: Technical and physiological fundaments and principal indications.
Romay, E; Ferrer, R
2016-01-01
In recent years, technological improvements have reduced the complexity of extracorporeal membrane oxygenation devices. This have enabled the development of specific devices for the extracorporeal removal of CO2. These devices have a simpler configuration than extracorporeal membrane oxygenation devices and uses lower blood flows which could reduce the potential complications. Experimental studies have demonstrated the feasibility, efficacy and safety of extracorporeal removal of CO2 and some of its effects in humans. This technique was initially conceived as an adjunct therapy in patients with severe acute respiratory distress syndrome, as a tool to optimize protective ventilation. More recently, the use of this technique has allowed the emergence of a relatively new concept called "tra-protective ventilation"whose effects are still to be determined. In addition, the extracorporeal removal of CO2 has been used in patients with exacerbated hypercapnic respiratory failure with promising results. In this review we will describe the physiological and technical fundamentals of this therapy and its variants as well as an overview of the available clinical evidence, focused on its current potential. Copyright © 2015 Elsevier España, S.L.U. and SEMICYUC. All rights reserved.
Double Stokes-Mueller polarimetry in KTP (Potassium Titanyl Phosphate) crystal
NASA Astrophysics Data System (ADS)
Shaji, Chitra; S B, Sruthil Lal; Sharan, Alok
2017-04-01
Ultra-structural properties of material are being probed by Double Stokes-Mueller polarimetry (DSMP) technique. It makes use of higher dimensions of Stokes vector (9 X 1) and Mueller matrix (4 X9) to characterize the nonlinear optical properties of a material. Second harmonic generation (SHG) at 532nm using 1064nm as fundamental cw beam from Nd: YAG laser in type II phase matched KTP (Potassium Titanyl Phosphate) crystal is studied using DSMP. The experimental measurements for determining double Mueller matrix are carried out in the ``Polarization In Polarization Out'' (PIPO) arrangement. Nine input polarization states are incident on the sample and the linear Stokes vector of the emerging light from the sample is measured. The KTP crystal is oriented such that the SHG signal efficiency at the incident horizontal and vertical polarizations is high as compared to diagonal polarization states. The susceptibility tensor components and the phase difference between them at this orientation are determined from the double Mueller matrix elements. These determined values give information regarding the crystal axis orientations. To our knowledge, this is the first report of the use of DSMP technique to determine the crystal orientations of a biaxial crystal.
Magnetic resonance spectroscopic imaging at superresolution: Overview and perspectives.
Kasten, Jeffrey; Klauser, Antoine; Lazeyras, François; Van De Ville, Dimitri
2016-02-01
The notion of non-invasive, high-resolution spatial mapping of metabolite concentrations has long enticed the medical community. While magnetic resonance spectroscopic imaging (MRSI) is capable of achieving the requisite spatio-spectral localization, it has traditionally been encumbered by significant resolution constraints that have thus far undermined its clinical utility. To surpass these obstacles, research efforts have primarily focused on hardware enhancements or the development of accelerated acquisition strategies to improve the experimental sensitivity per unit time. Concomitantly, a number of innovative reconstruction techniques have emerged as alternatives to the standard inverse discrete Fourier transform (DFT). While perhaps lesser known, these latter methods strive to effect commensurate resolution gains by exploiting known properties of the underlying MRSI signal in concert with advanced image and signal processing techniques. This review article aims to aggregate and provide an overview of the past few decades of so-called "superresolution" MRSI reconstruction methodologies, and to introduce readers to current state-of-the-art approaches. A number of perspectives are then offered as to the future of high-resolution MRSI, with a particular focus on translation into clinical settings. Copyright © 2015 Elsevier Inc. All rights reserved.
Emerging optical nanoscopy techniques
Montgomery, Paul C; Leong-Hoi, Audrey
2015-01-01
To face the challenges of modern health care, new imaging techniques with subcellular resolution or detection over wide fields are required. Far field optical nanoscopy presents many new solutions, providing high resolution or detection at high speed. We present a new classification scheme to help appreciate the growing number of optical nanoscopy techniques. We underline an important distinction between superresolution techniques that provide improved resolving power and nanodetection techniques for characterizing unresolved nanostructures. Some of the emerging techniques within these two categories are highlighted with applications in biophysics and medicine. Recent techniques employing wider angle imaging by digital holography and scattering lens microscopy allow superresolution to be achieved for subcellular and even in vivo, imaging without labeling. Nanodetection techniques are divided into four subcategories using contrast, phase, deconvolution, and nanomarkers. Contrast enhancement is illustrated by means of a polarized light-based technique and with strobed phase-contrast microscopy to reveal nanostructures. Very high sensitivity phase measurement using interference microscopy is shown to provide nanometric surface roughness measurement or to reveal internal nanometric structures. Finally, the use of nanomarkers is illustrated with stochastic fluorescence microscopy for mapping intracellular structures. We also present some of the future perspectives of optical nanoscopy. PMID:26491270
Girolametto, Luigi; Weitzman, Elaine; Greenberg, Janice
2012-02-01
This study examined the efficacy of a professional development program for early childhood educators that facilitated emergent literacy skills in preschoolers. The program, led by a speech-language pathologist, focused on teaching alphabet knowledge, print concepts, sound awareness, and decontextualized oral language within naturally occurring classroom interactions. Twenty educators were randomly assigned to experimental and control groups. Educators each recruited 3 to 4 children from their classrooms to participate. The experimental group participated in 18 hr of group training and 3 individual coaching sessions with a speech-language pathologist. The effects of intervention were examined in 30 min of videotaped interaction, including storybook reading and a post-story writing activity. At posttest, educators in the experimental group used a higher rate of utterances that included print/sound references and decontextualized language than the control group. Similarly, the children in the experimental group used a significantly higher rate of utterances that included print/sound references and decontextualized language compared to the control group. These findings suggest that professional development provided by a speech-language pathologist can yield short-term changes in the facilitation of emergent literacy skills in early childhood settings. Future research is needed to determine the impact of this program on the children's long-term development of conventional literacy skills.
Emergence of complementarity and the Baconian roots of Niels Bohr's method
NASA Astrophysics Data System (ADS)
Perovic, Slobodan
2013-08-01
I argue that instead of a rather narrow focus on N. Bohr's account of complementarity as a particular and perhaps obscure metaphysical or epistemological concept (or as being motivated by such a concept), we should consider it to result from pursuing a particular method of studying physical phenomena. More precisely, I identify a strong undercurrent of Baconian method of induction in Bohr's work that likely emerged during his experimental training and practice. When its development is analyzed in light of Baconian induction, complementarity emerges as a levelheaded rather than a controversial account, carefully elicited from a comprehensive grasp of the available experimental basis, shunning hasty metaphysically motivated generalizations based on partial experimental evidence. In fact, Bohr's insistence on the "classical" nature of observations in experiments, as well as the counterintuitive synthesis of wave and particle concepts that have puzzled scholars, seem a natural outcome (an updated instance) of the inductive method. Such analysis clarifies the intricacies of early Schrödinger's critique of the account as well as Bohr's response, which have been misinterpreted in the literature. If adequate, the analysis may lend considerable support to the view that Bacon explicated the general terms of an experimentally minded strand of the scientific method, developed and refined by scientists in the following three centuries.
Volcano deformation--Geodetic monitoring techniques
Dzurisin, Daniel; Lu, Zhong
2007-01-01
This book describes the techniques used by volcanologists to successfully predict several recent volcanic eruptions by combining information from various scientific disciplines, including geodetic techniques. Many recent developments in the use of state-of-the-art and emerging techniques, including Global Positioning System and Synthetic Aperture Radar Interferometry, mean that most books on volcanology are out of date, and this book includes chapters devoted entirely to these two techniques.
Yang, Jun; Sudik, Andrea; Wolverton, Christopher; Siegel, Donald J
2010-02-01
Widespread adoption of hydrogen as a vehicular fuel depends critically upon the ability to store hydrogen on-board at high volumetric and gravimetric densities, as well as on the ability to extract/insert it at sufficiently rapid rates. As current storage methods based on physical means--high-pressure gas or (cryogenic) liquefaction--are unlikely to satisfy targets for performance and cost, a global research effort focusing on the development of chemical means for storing hydrogen in condensed phases has recently emerged. At present, no known material exhibits a combination of properties that would enable high-volume automotive applications. Thus new materials with improved performance, or new approaches to the synthesis and/or processing of existing materials, are highly desirable. In this critical review we provide a practical introduction to the field of hydrogen storage materials research, with an emphasis on (i) the properties necessary for a viable storage material, (ii) the computational and experimental techniques commonly employed in determining these attributes, and (iii) the classes of materials being pursued as candidate storage compounds. Starting from the general requirements of a fuel cell vehicle, we summarize how these requirements translate into desired characteristics for the hydrogen storage material. Key amongst these are: (a) high gravimetric and volumetric hydrogen density, (b) thermodynamics that allow for reversible hydrogen uptake/release under near-ambient conditions, and (c) fast reaction kinetics. To further illustrate these attributes, the four major classes of candidate storage materials--conventional metal hydrides, chemical hydrides, complex hydrides, and sorbent systems--are introduced and their respective performance and prospects for improvement in each of these areas is discussed. Finally, we review the most valuable experimental and computational techniques for determining these attributes, highlighting how an approach that couples computational modeling with experiments can significantly accelerate the discovery of novel storage materials (155 references).
Vu, Trung Nghia; Mrzic, Aida; Valkenborg, Dirk; Maes, Evelyne; Lemière, Filip; Goethals, Bart; Laukens, Kris
2014-01-01
Mass spectrometry-based proteomics experiments generate spectra that are rich in information. Often only a fraction of this information is used for peptide/protein identification, whereas a significant proportion of the peaks in a spectrum remain unexplained. In this paper we explore how a specific class of data mining techniques termed "frequent itemset mining" can be employed to discover patterns in the unassigned data, and how such patterns can help us interpret the origin of the unexpected/unexplained peaks. First a model is proposed that describes the origin of the observed peaks in a mass spectrum. For this purpose we use the classical correlative database search algorithm. Peaks that support a positive identification of the spectrum are termed explained peaks. Next, frequent itemset mining techniques are introduced to infer which unexplained peaks are associated in a spectrum. The method is validated on two types of experimental proteomic data. First, peptide mass fingerprint data is analyzed to explain the unassigned peaks in a full scan mass spectrum. Interestingly, a large numbers of experimental spectra reveals several highly frequent unexplained masses, and pattern mining on these frequent masses demonstrates that subsets of these peaks frequently co-occur. Further evaluation shows that several of these co-occurring peaks indeed have a known common origin, and other patterns are promising hypothesis generators for further analysis. Second, the proposed methodology is validated on tandem mass spectrometral data using a public spectral library, where associations within the mass differences of unassigned peaks and peptide modifications are explored. The investigation of the found patterns illustrates that meaningful patterns can be discovered that can be explained by features of the employed technology and found modifications. This simple approach offers opportunities to monitor accumulating unexplained mass spectrometry data for emerging new patterns, with possible applications for the development of mass exclusion lists, for the refinement of quality control strategies and for a further interpretation of unexplained spectral peaks in mass spectrometry and tandem mass spectrometry.
NASA Astrophysics Data System (ADS)
Rossi, Francesca; Matteini, Paolo; Ratto, Fulvio; Pini, Roberto; Iacoangeli, Maurizio; Giannoni, Luca; Fortuna, Damiano; Di Cicco, Emiliano; Corbara, Sylwia; Dallari, Stefano
2014-05-01
Laser bonding is a promising minimally invasive approach, emerging as a valid alternative to conventional suturing techniques. It shows widely demonstrated advantages in wound treatment: immediate closuring effect, minimal inflammatory response and scar formation, reduced healing time. This laser based technique can overcome the difficulties in working through narrow surgical corridors (e.g. the modern "key-hole" surgery as well as the endoscopy setting) or in thin tissues that are impossible to treat with staples and/or stitches. We recently proposed the use of chitosan matrices, stained with conventional chromophores, to be used in laser bonding of vascular tissue. In this work we propose the same procedure to perform laser bonding of vocal folds and dura mater repair. Laser bonding of vocal folds is proposed to avoid the development of adhesions (synechiae), after conventional or CO2 laser surgery. Laser bonding application in neurosurgery is proposed for the treatment of dural defects being the Cerebro Spinal Fluid leaks still a major issue. Vocal folds and dura mater were harvested from 9-months old porks and used in the experimental sessions within 4 hours after sacrifice. In vocal folds treatment, an IdocyanineGreen-infused chitosan patch was applied onto the anterior commissure, while the dura mater was previously incised and then bonded. A diode laser emitting at 810 nm, equipped with a 600 μm diameter optical fiber was used to weld the patch onto the tissue, by delivering single laser spots to induce local patch/tissue adhesion. The result is an immediate adhesion of the patch to the tissue. Standard histology was performed, in order to study the induced photothermal effect at the bonding sites. This preliminary experimental activity shows the advantages of the proposed technique in respect to standard surgery: simplification of the procedure; decreased foreign-body reaction; reduced inflammatory response; reduced operating times and better handling in depth.
Pascacio-Villafán, Carlos; Birke, Andrea; Williams, Trevor; Aluja, Martín
2017-01-01
We modeled the cost-effectiveness of rearing Anastrepha ludens, a major fruit fly pest currently mass reared for sterilization and release in pest control programs implementing the sterile insect technique (SIT). An optimization model was generated by combining response surface models of artificial diet cost savings with models of A. ludens pupation, pupal weight, larval development time and adult emergence as a function of mixtures of yeast, a costly ingredient, with corn flour and corncob fractions in the diet. Our model revealed several yeast-reduced mixtures that could be used to prepare diets that were considerably cheaper than a standard diet used for mass rearing. Models predicted a similar production of insects (pupation and adult emergence), with statistically similar pupal weights and larval development times between yeast-reduced diets and the standard mass rearing diet formulation. Annual savings from using the modified diets could be up to 5.9% of the annual cost of yeast, corn flour and corncob fractions used in the standard diet, representing a potential saving of US $27.45 per ton of diet (US $47,496 in the case of the mean annual production of 1,730.29 tons of artificial diet in the Moscafrut mass rearing facility at Metapa, Chiapas, Mexico). Implementation of the yeast-reduced diet on an experimental scale at mass rearing facilities is still required to confirm the suitability of new mixtures of artificial diet for rearing A. ludens for use in SIT. This should include the examination of critical quality control parameters of flies such as adult flight ability, starvation resistance and male sexual competitiveness across various generations. The method used here could be useful for improving the cost-effectiveness of invertebrate or vertebrate mass rearing diets worldwide.
Birke, Andrea; Williams, Trevor; Aluja, Martín
2017-01-01
We modeled the cost-effectiveness of rearing Anastrepha ludens, a major fruit fly pest currently mass reared for sterilization and release in pest control programs implementing the sterile insect technique (SIT). An optimization model was generated by combining response surface models of artificial diet cost savings with models of A. ludens pupation, pupal weight, larval development time and adult emergence as a function of mixtures of yeast, a costly ingredient, with corn flour and corncob fractions in the diet. Our model revealed several yeast-reduced mixtures that could be used to prepare diets that were considerably cheaper than a standard diet used for mass rearing. Models predicted a similar production of insects (pupation and adult emergence), with statistically similar pupal weights and larval development times between yeast-reduced diets and the standard mass rearing diet formulation. Annual savings from using the modified diets could be up to 5.9% of the annual cost of yeast, corn flour and corncob fractions used in the standard diet, representing a potential saving of US $27.45 per ton of diet (US $47,496 in the case of the mean annual production of 1,730.29 tons of artificial diet in the Moscafrut mass rearing facility at Metapa, Chiapas, Mexico). Implementation of the yeast-reduced diet on an experimental scale at mass rearing facilities is still required to confirm the suitability of new mixtures of artificial diet for rearing A. ludens for use in SIT. This should include the examination of critical quality control parameters of flies such as adult flight ability, starvation resistance and male sexual competitiveness across various generations. The method used here could be useful for improving the cost-effectiveness of invertebrate or vertebrate mass rearing diets worldwide. PMID:28257496
Emerging Techniques 2: Architectural Programming.
ERIC Educational Resources Information Center
Evans, Benjamin H.; Wheeler, C. Herbert, Jr.
A selected collection of architectural programming techniques has been assembled to aid architects in building design. Several exciting and sophisticated techniques for determining a basis for environmental design have been developed in recent years. These extend to the logic of environmental design and lead to more appropriate and useful…
Experimental Techniques for Thermodynamic Measurements of Ceramics
NASA Technical Reports Server (NTRS)
Jacobson, Nathan S.; Putnam, Robert L.; Navrotsky, Alexandra
1999-01-01
Experimental techniques for thermodynamic measurements on ceramic materials are reviewed. For total molar quantities, calorimetry is used. Total enthalpies are determined with combustion calorimetry or solution calorimetry. Heat capacities and entropies are determined with drop calorimetry, differential thermal methods, and adiabatic calorimetry . Three major techniques for determining partial molar quantities are discussed. These are gas equilibration techniques, Knudsen cell methods, and electrochemical techniques. Throughout this report, issues unique to ceramics are emphasized. Ceramic materials encompass a wide range of stabilities and this must be considered. In general data at high temperatures is required and the need for inert container materials presents a particular challenge.
NASA Technical Reports Server (NTRS)
Erickson, Gary E.
2007-01-01
An overview is given of selected measurement techniques used in the NASA Langley Research Center (NASA LaRC) Unitary Plan Wind Tunnel (UPWT) to determine the aerodynamic characteristics of aerospace vehicles operating at supersonic speeds. A broad definition of a measurement technique is adopted in this paper and is any qualitative or quantitative experimental approach that provides information leading to the improved understanding of the supersonic aerodynamic characteristics. On-surface and off-surface measurement techniques used to obtain discrete (point) and global (field) measurements and planar and global flow visualizations are described, and examples of all methods are included. The discussion is limited to recent experiences in the UPWT and is, therefore, not an exhaustive review of existing experimental techniques. The diversity and high quality of the measurement techniques and the resultant data illustrate the capabilities of a ground-based experimental facility and the key role that it plays in the advancement of our understanding, prediction, and control of supersonic aerodynamics.
Thermoreflectance spectroscopy—Analysis of thermal processes in semiconductor lasers
NASA Astrophysics Data System (ADS)
Pierścińska, D.
2018-01-01
This review focuses on theoretical foundations, experimental implementation and an overview of experimental results of the thermoreflectance spectroscopy as a powerful technique for temperature monitoring and analysis of thermal processes in semiconductor lasers. This is an optical, non-contact, high spatial resolution technique providing high temperature resolution and mapping capabilities. Thermoreflectance is a thermometric technique based on measuring of relative change of reflectivity of the surface of laser facet, which provides thermal images useful in hot spot detection and reliability studies. In this paper, principles and experimental implementation of the technique as a thermography tool is discussed. Some exemplary applications of TR to various types of lasers are presented, proving that thermoreflectance technique provides new insight into heat management problems in semiconductor lasers and in particular, that it allows studying thermal degradation processes occurring at laser facets. Additionally, thermal processes and basic mechanisms of degradation of the semiconductor laser are discussed.
Micieli, Giuseppe; De Falco, Fabrizio A; Consoli, Domenico; Inzitari, Domenico; Sterzi, Roberto; Tedeschi, Gioacchino; Toni, Danilo
2012-04-01
A possible definition of clinical, educational and organizing aspects of emergency neurology in Italy is reported in this position paper of Emergency Neurology Intersociety Group, created in 2008 among the two neurological Societies in Italy: Società Italiana di Neurologia and Società di Neuroscienze Ospedaliere. The aim of this Group has been the evaluation of the role of neurologist in the emergency setting of Italian hospitals, as well as of the description of different scenarios in which a ward dedicated to a semi-intensive care of neurological emergencies could have a role in the actual organization of academic or general hospitals in our Country. The actual great relevance of neurologist activity in the inpatients treatment, in fact, is actually misleaded as it is the considerable significance of neurological expertise, techniques and support in hospital care pathways also involving neurological manifestations throughout the course of other diseases. Finally, the possible contents of educational programs orienting neurological specialty towards a better comprehension and management of emergency neurological problems either in terms of specific formation or of techniques to be learned by emergency neurologist, are reported as a results of the Consensus Workshop hold in Castiglioncello (LI) in September 12th, 2009.
Dormer, Nathan H.; Berkland, Cory J.; Detamore, Michael S.
2013-01-01
Interfacial tissue engineering is an emerging branch of regenerative medicine, where engineers are faced with developing methods for the repair of one or many functional tissue systems simultaneously. Early and recent solutions for complex tissue formation have utilized stratified designs, where scaffold formulations are segregated into two or more layers, with discrete changes in physical or chemical properties, mimicking a corresponding number of interfacing tissue types. This method has brought forth promising results, along with a myriad of regenerative techniques. The latest designs, however, are employing “continuous gradients” in properties, where there is no discrete segregation between scaffold layers. This review compares the methods and applications of recent stratified approaches to emerging continuously graded methods. PMID:20411333
EFSUMB guidelines 2011: comment on emergent indications and visions.
Dietrich, C F; Cui, X W; Barreiros, A P; Hocke, M; Ignee, A
2012-07-01
The focus of this article is the emergent and potential indications of contrast-enhanced ultrasound (CEUS). Emergent applications of CEUS techniques include extravascular and intracavitary contrast-enhanced ultrasound, quantitative assessment of microvascular circulation for tumor response assessment, and tumor characterization using dynamic contrast-enhanced ultrasound (DCE-US). Potential indications for microbubble agents include novel molecular imaging and drug and gene delivery techniques, which have been successfully tested in animal models. "Comments and Illustrations of the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) Non-Liver Guidelines 2011" which focus more on established applications are published in the same supplement to Ultraschall in der Medizin (European Journal of Ultrasound). © Georg Thieme Verlag KG Stuttgart · New York.
New experimental techniques for solar cells
NASA Technical Reports Server (NTRS)
Lenk, R.
1993-01-01
Solar cell capacitance has special importance for an array controlled by shunting. Experimental measurements of solar cell capacitance in the past have shown disagreements of orders of magnitude. Correct measurement technique depends on maintaining the excitation voltage less than the thermal voltage. Two different experimental methods are shown to match theory well, and two effective capacitances are defined for quantifying the effect of the solar cell capacitance on the shunting system.
Daniel G. Neary; Peter R. Robichaud; Jan L. Beyers
2000-01-01
Following wildfires, burned areas are assessed by special teams to determine if emergency watershed rehabilitation measures are required to restore watershed function and minimize damage to soil resources. The objective of burned area emergency rehabilitation (BAER) treatments is to restore watershed condition and reduce erosional losses on hillslopes, in channels, and...
Polarisation Dynamics of Vector Soliton Molecules in Mode Locked Fibre Laser
Tsatourian, Veronika; Sergeyev, Sergey V.; Mou, Chengbo; Rozhin, Alex; Mikhailov, Vitaly; Rabin, Bryan; Westbrook, Paul S.; Turitsyn, Sergei K.
2013-01-01
Two fundamental laser physics phenomena - dissipative soliton and polarisation of light are recently merged to the concept of vector dissipative soliton (VDS), viz. train of short pulses with specific state of polarisation (SOP) and shape defined by an interplay between anisotropy, gain/loss, dispersion, and nonlinearity. Emergence of VDSs is both of the fundamental scientific interest and is also a promising technique for control of dynamic SOPs important for numerous applications from nano-optics to high capacity fibre optic communications. Using specially designed and developed fast polarimeter, we present here the first experimental results on SOP evolution of vector soliton molecules with periodic polarisation switching between two and three SOPs and superposition of polarisation switching with SOP precessing. The underlying physics presents an interplay between linear and circular birefringence of a laser cavity along with light induced anisotropy caused by polarisation hole burning. PMID:24193374
Polarisation Dynamics of Vector Soliton Molecules in Mode Locked Fibre Laser
NASA Astrophysics Data System (ADS)
Tsatourian, Veronika; Sergeyev, Sergey V.; Mou, Chengbo; Rozhin, Alex; Mikhailov, Vitaly; Rabin, Bryan; Westbrook, Paul S.; Turitsyn, Sergei K.
2013-11-01
Two fundamental laser physics phenomena - dissipative soliton and polarisation of light are recently merged to the concept of vector dissipative soliton (VDS), viz. train of short pulses with specific state of polarisation (SOP) and shape defined by an interplay between anisotropy, gain/loss, dispersion, and nonlinearity. Emergence of VDSs is both of the fundamental scientific interest and is also a promising technique for control of dynamic SOPs important for numerous applications from nano-optics to high capacity fibre optic communications. Using specially designed and developed fast polarimeter, we present here the first experimental results on SOP evolution of vector soliton molecules with periodic polarisation switching between two and three SOPs and superposition of polarisation switching with SOP precessing. The underlying physics presents an interplay between linear and circular birefringence of a laser cavity along with light induced anisotropy caused by polarisation hole burning.
Photonics and spectroscopy in nanojunctions: a theoretical insight
Galperin, Michael
2017-04-11
The progress of experimental techniques at the nanoscale in the last decade made optical measurements in current-carrying nanojunctions a reality, thus indicating the emergence of a new field of research coined optoelectronics. Optical spectroscopy of open nonequilibrium systems is a natural meeting point for (at least) two research areas: nonlinear optical spectroscopy and quantum transport, each with its own theoretical toolbox. We review recent progress in the field comparing theoretical treatments of optical response in nanojunctions as is accepted in nonlinear spectroscopy and quantum transport communities. A unified theoretical description of spectroscopy in nanojunctions is presented. Here, we argue thatmore » theoretical approaches of the quantum transport community (and in particular, the Green function based considerations) yield a convenient tool for optoelectronics when the radiation field is treated classically, and that differences between the toolboxes may become critical when studying the quantum radiation field in junctions.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Merkley, Eric D.; Cort, John R.; Adkins, Joshua N.
2013-09-01
Multiprotein complexes, rather than individual proteins, make up a large part of the biological macromolecular machinery of a cell. Understanding the structure and organization of these complexes is critical to understanding cellular function. Chemical cross-linking coupled with mass spectrometry is emerging as a complementary technique to traditional structural biology methods and can provide low-resolution structural information for a multitude of purposes, such as distance constraints in computational modeling of protein complexes. In this review, we discuss the experimental considerations for successful application of chemical cross-linking-mass spectrometry in biological studies and highlight three examples of such studies from the recent literature.more » These examples (as well as many others) illustrate the utility of a chemical cross-linking-mass spectrometry approach in facilitating structural analysis of large and challenging complexes.« less
The speed-accuracy tradeoff: history, physiology, methodology, and behavior
Heitz, Richard P.
2014-01-01
There are few behavioral effects as ubiquitous as the speed-accuracy tradeoff (SAT). From insects to rodents to primates, the tendency for decision speed to covary with decision accuracy seems an inescapable property of choice behavior. Recently, the SAT has received renewed interest, as neuroscience approaches begin to uncover its neural underpinnings and computational models are compelled to incorporate it as a necessary benchmark. The present work provides a comprehensive overview of SAT. First, I trace its history as a tractable behavioral phenomenon and the role it has played in shaping mathematical descriptions of the decision process. Second, I present a “users guide” of SAT methodology, including a critical review of common experimental manipulations and analysis techniques and a treatment of the typical behavioral patterns that emerge when SAT is manipulated directly. Finally, I review applications of this methodology in several domains. PMID:24966810
Bovill, Estas; Banwell, Paul E; Teot, Luc; Eriksson, Elof; Song, Colin; Mahoney, Jim; Gustafsson, Ronny; Horch, Raymund; Deva, Anand; Whitworth, Ian
2008-10-01
Over the past two decades, topical negative pressure (TNP) wound therapy has gained wide acceptance as a genuine strategy in the treatment algorithm for a wide variety of acute and chronic wounds. Although extensive experimental and clinical evidence exists to support its use and despite the recent emergence of randomised control trials, its role and indications have yet to be fully determined. This article provides a qualitative overview of the published literature appertaining to the use of TNP therapy in the management of acute wounds by an international panel of experts using standard methods of appraisal. Particular focus is applied to the use of TNP for the open abdomen, sternal wounds, lower limb trauma, burns and tissue coverage with grafts and dermal substitutes. We provide evidence-based recommendations for indications and techniques in TNP wound therapy and, where studies are insufficient, consensus on best practice.
QSAR modeling of GPCR ligands: methodologies and examples of applications.
Tropsha, A; Wang, S X
2006-01-01
GPCR ligands represent not only one of the major classes of current drugs but the major continuing source of novel potent pharmaceutical agents. Because 3D structures of GPCRs as determined by experimental techniques are still unavailable, ligand-based drug discovery methods remain the major computational molecular modeling approaches to the analysis of growing data sets of tested GPCR ligands. This paper presents an overview of modern Quantitative Structure Activity Relationship (QSAR) modeling. We discuss the critical issue of model validation and the strategy for applying the successfully validated QSAR models to virtual screening of available chemical databases. We present several examples of applications of validated QSAR modeling approaches to GPCR ligands. We conclude with the comments on exciting developments in the QSAR modeling of GPCR ligands that focus on the study of emerging data sets of compounds with dual or even multiple activities against two or more of GPCRs.
Integrative Systems Models of Cardiac Excitation Contraction Coupling
Greenstein, Joseph L.; Winslow, Raimond L.
2010-01-01
Excitation-contraction coupling in the cardiac myocyte is mediated by a number of highly integrated mechanisms of intracellular Ca2+ transport. The complexity and integrative nature of heart cell electrophysiology and Ca2+-cycling has led to an evolution of computational models that have played a crucial role in shaping our understanding of heart function. An important emerging theme in systems biology is that the detailed nature of local signaling events, such as those that occur in the cardiac dyad, have important consequences at higher biological scales. Multi-scale modeling techniques have revealed many mechanistic links between micro-scale events, such as Ca2+ binding to a channel protein, and macro-scale phenomena, such as excitation-contraction coupling gain. Here we review experimentally based multi-scale computational models of excitation-contraction coupling and the insights that have been gained through their application. PMID:21212390
Charge-transfer crystallites as molecular electrical dopants
Méndez, Henry; Heimel, Georg; Winkler, Stefanie; Frisch, Johannes; Opitz, Andreas; Sauer, Katrein; Wegner, Berthold; Oehzelt, Martin; Röthel, Christian; Duhm, Steffen; Többens, Daniel; Koch, Norbert; Salzmann, Ingo
2015-01-01
Ground-state integer charge transfer is commonly regarded as the basic mechanism of molecular electrical doping in both, conjugated polymers and oligomers. Here, we demonstrate that fundamentally different processes can occur in the two types of organic semiconductors instead. Using complementary experimental techniques supported by theory, we contrast a polythiophene, where molecular p-doping leads to integer charge transfer reportedly localized to one quaterthiophene backbone segment, to the quaterthiophene oligomer itself. Despite a comparable relative increase in conductivity, we observe only partial charge transfer for the latter. In contrast to the parent polymer, pronounced intermolecular frontier-orbital hybridization of oligomer and dopant in 1:1 mixed-stack co-crystallites leads to the emergence of empty electronic states within the energy gap of the surrounding quaterthiophene matrix. It is their Fermi–Dirac occupation that yields mobile charge carriers and, therefore, the co-crystallites—rather than individual acceptor molecules—should be regarded as the dopants in such systems. PMID:26440403
Wolenski, Francis S; Layden, Michael J; Martindale, Mark Q; Gilmore, Thomas D; Finnerty, John R
2016-01-01
In an effort to reconstruct the early evolution of animal genes and proteins, there is an increasing focus on basal animal lineages such as sponges, cnidarians, ctenophores and placozoans. Among the basal animals, the starlet sea anemone Nematostella vectensis (phylum Cnidaria) has emerged as a leading laboratory model organism partly because it is well suited to experimental techniques for monitoring and manipulating gene expression. Here we describe protocols adapted for use in Nematostella to characterize the expression of RNAs by in situ hybridization using either chromogenic or fluorescence immunohistochemistry (~1 week), as well as to characterize protein expression by whole-mount immunofluorescence (~3 d). We also provide a protocol for labeling cnidocytes (~3 h), the phylum-specific sensory-effector cell type that performs a variety of functions in cnidarians, including the delivery of their venomous sting. PMID:23579779
Lintern, Melvyn; Anand, Ravi; Ryan, Chris; Paterson, David
2013-01-01
Eucalyptus trees may translocate Au from mineral deposits and support the use of vegetation (biogeochemical) sampling in mineral exploration, particularly where thick sediments dominate. However, biogeochemistry has not been routinely adopted partly because biotic mechanisms of Au migration are poorly understood. For example, although Au has been previously measured in plant samples, there has been doubt as to whether it was truly absorbed rather than merely adsorbed on the plant surface as aeolian contamination. Here we show the first evidence of particulate Au within natural specimens of living biological tissue (not from laboratory experimentation). This observation conclusively demonstrates active biogeochemical adsorption of Au and provides insight into its behaviour in natural samples. The confirmation of biogeochemical adsorption of Au, and of a link with abiotic processes, promotes confidence in an emerging technique that may lead to future exploration success and maintain continuity of supply. PMID:24149278
Chung, Seungjoon; Seo, Chang Duck; Choi, Jae-Hoon; Chung, Jinwook
2014-01-01
Membrane distillation (MD) is an emerging desalination technology as an energy-saving alternative to conventional distillation and reverse osmosis method. The selection of appropriate membrane is a prerequisite for the design of an optimized MD process. We proposed a simple approximation method to evaluate the performance of membranes for MD process. Three hollow fibre-type commercial membranes with different thicknesses and pore sizes were tested. Experimental results showed that one membrane was advantageous due to the highest flux, whereas another membrane was due to the lowest feed temperature drop. Regression analyses and multi-stage calculations were used to account for the trade-offeffects of flux and feed temperature drop. The most desirable membrane was selected from tested membranes in terms of the mean flux in a multi-stage process. This method would be useful for the selection of the membranes without complicated simulation techniques.
Stretchable inductor with liquid magnetic core
NASA Astrophysics Data System (ADS)
Lazarus, N.; Meyer, C. D.
2016-03-01
Adding magnetic materials is a well-established method for improving performance of inductors. However, traditional magnetic cores are rigid and poorly suited for the emerging field of stretchable electronics, where highly deformable inductors are used to wirelessly couple power and data signals. In this work, stretchable inductors are demonstrated based on the use of ferrofluids, magnetic liquids based on distributed magnetic particles, to create a compliant magnetic core. Using a silicone molding technique to create multi-layer fluidic channels, a liquid metal solenoid is fabricated around a ferrofluid channel. An analytical model is developed for the effects of mechanical strain, followed by experimental verification using two different ferrofluids with different permeabilities. Adding ferrofluid was found to increase the unstrained inductance by up to 280% relative to a similar inductor with a non-magnetic silicone core, while retaining the ability to survive uniaxial strains up to 100%.
Micro-PIV Study of Supercritical CO2-Water Interactions in Porous Micromodels
NASA Astrophysics Data System (ADS)
Kazemifar, Farzan; Blois, Gianluca; Christensen, Kenneth T.
2015-11-01
Multiphase flow of immiscible fluids in porous media is encountered in numerous natural systems and engineering applications such as enhanced oil recovery (EOR), and CO2 sequestration among others. Geological sequestration of CO2 in saline aquifers has emerged as a viable option for reducing CO2 emissions, and thus it has been the subject of numerous studies in recent years. A key objective is improving the accuracy of numerical models used for field-scale simulations by incorporation/better representation of the pore-scale flow physics. This necessitates experimental data for developing, testing and validating such models. We have studied drainage and imbibition processes in a homogeneous, two-dimensional porous micromodel with CO2 and water at reservoir-relevant conditions. Microscopic particle image velocimetry (micro-PIV) technique was applied to obtain spatially- and temporally-resolved velocity vector fields in the aqueous phase. The results provide new insight into the flow processes at the pore scale.
Habitat Management to Suppress Pest Populations: Progress and Prospects.
Gurr, Geoff M; Wratten, Steve D; Landis, Douglas A; You, Minsheng
2017-01-31
Habitat management involving manipulation of farmland vegetation can exert direct suppressive effects on pests and promote natural enemies. Advances in theory and practical techniques have allowed habitat management to become an important subdiscipline of pest management. Improved understanding of biodiversity-ecosystem function relationships means that researchers now have a firmer theoretical foundation on which to design habitat management strategies for pest suppression in agricultural systems, including landscape-scale effects. Supporting natural enemies with shelter, nectar, alternative prey/hosts, and pollen (SNAP) has emerged as a major research topic and applied tactic with field tests and adoption often preceded by rigorous laboratory experimentation. As a result, the promise of habitat management is increasingly being realized in the form of practical worldwide implementation. Uptake is facilitated by farmer participation in research and is made more likely by the simultaneous delivery of ecosystem services other than pest suppression.
NASA Astrophysics Data System (ADS)
Zare, Mohammad-Hossein; Biderang, Mehdi; Akbari, Alireza
2017-11-01
We study the symmetry of the potential superconducting order parameter in 5 d Mott insulators with an eye toward hole-doped Sr2IrO4 . Using a mean-field method, a mixed singlet-triplet superconductivity, d +p , is observed due to the antisymmetric exchange originating from a quasi-spin-orbit coupling. Our calculation on ribbon geometry shows the possible existence of the topologically protected edge states, because of the nodal structure of the superconducting gap. These edge modes are spin polarized and emerge as zero-energy flat bands, supporting a symmetry-protected Majorana state, verified by evaluation of the winding number and Z2 topological invariant. At the end, a possible experimental approach for observation of these edge states and determination of the superconducting gap symmetry is discussed based on the quasiparticle interference technique.
Unsteady flow past an airfoil pitched at constant rate
NASA Technical Reports Server (NTRS)
Lourenco, L.; Vandommelen, L.; Shib, C.; Krothapalli, A.
1992-01-01
The unsteady flow past a NACA 0012 airfoil that is undertaking a constant-rate pitching up motion is investigated experimentally by the PIDV technique in a water towing tank. The Reynolds number is 5000, based upon the airfoil's chord and the free-stream velocity. The airfoil is pitching impulsively from 0 to 30 deg. with a dimensionless pitch rate alpha of 0.131. Instantaneous velocity and associated vorticity data have been acquired over the entire flow field. The primary vortex dominates the flow behavior after it separates from the leading edge of the airfoil. Complete stall emerges after this vortex detaches from the airfoil and triggers the shedding of a counter-rotating vortex near the trailing edge. A parallel computational study using the discrete vortex, random walk approximation has also been conducted. In general, the computational results agree very well with the experiment.
Accelerating Full Configuration Interaction Calculations for Nuclear Structure
DOE Office of Scientific and Technical Information (OSTI.GOV)
Yang, Chao; Sternberg, Philip; Maris, Pieter
2008-04-14
One of the emerging computational approaches in nuclear physics is the full configuration interaction (FCI) method for solving the many-body nuclear Hamiltonian in a sufficiently large single-particle basis space to obtain exact answers - either directly or by extrapolation. The lowest eigenvalues and correspondingeigenvectors for very large, sparse and unstructured nuclear Hamiltonian matrices are obtained and used to evaluate additional experimental quantities. These matrices pose a significant challenge to the design and implementation of efficient and scalable algorithms for obtaining solutions on massively parallel computer systems. In this paper, we describe the computational strategies employed in a state-of-the-art FCI codemore » MFDn (Many Fermion Dynamics - nuclear) as well as techniques we recently developed to enhance the computational efficiency of MFDn. We will demonstrate the current capability of MFDn and report the latest performance improvement we have achieved. We will also outline our future research directions.« less
Defect generation in electronic devices under plasma exposure: Plasma-induced damage
NASA Astrophysics Data System (ADS)
Eriguchi, Koji
2017-06-01
The increasing demand for higher performance of ULSI circuits requires aggressive shrinkage of device feature sizes in accordance with Moore’s law. Plasma processing plays an important role in achieving fine patterns with anisotropic features in metal-oxide-semiconductor field-effect transistors (MOSFETs). This article comprehensively addresses the negative aspect of plasma processing — plasma-induced damage (PID). PID naturally not only modifies the surface morphology of materials but also degrades the performance and reliability of MOSFETs as a result of defect generation in the materials. Three key mechanisms of PID, i.e., physical, electrical, and photon-irradiation interactions, are overviewed in terms of modeling, characterization techniques, and experimental evidence reported so far. In addition, some of the emerging topics — control of parameter variability in ULSI circuits caused by PID and recovery of PID — are discussed as future perspectives.
From anatomy to function: diagnosis of atherosclerotic renal artery stenosis.
Odudu, Aghogho; Vassallo, Diana; Kalra, Philip A
2015-12-01
Atherosclerotic renal artery stenosis (ARAS) affects 7% of the over 65 s and will be increasingly common with an ageing population. ARAS obstructs normal renal perfusion with adverse renal and cardiovascular consequences. Drug therapy is directed at reducing atherosclerotic risk. Two recent major trials of revascularization for ARAS showed that clinical outcomes were not improved beyond those offered by optimal drug therapy in most patients. This reflects experimental data showing that restoration of blood flow alone may not attenuate a cascade of tissue injury. A shift from anatomic to functional imaging of ARAS coupled to novel therapies might improve clinical outcomes in selected patients. This review outlines the case for separately assessing hemodynamic significance of arterial stenosis and functional reserve of renal parenchymal tissue. The authors consider current and emerging diagnostic techniques for ARAS and their potential to allow individualized and functionally directed treatments.
A new way to make diamond tip hosting an atomic sized defect
NASA Astrophysics Data System (ADS)
Zhou, Tony; Stohr, Rainer; Dovzhenko, Yuliya; Casola, Francesco; Yacoby, Amir
The nitrogen-vacancy (NV) center in diamond has been fascinating people with its unique role in quantum information and magnetometry. NV magnetometry was used to investigate many fundamental physics studies and develop a number of industrial applications. One of the powerful aspects of NV magnetometry is the ability to scan in space to perform spatial magnetic field sensing with nano-meter resolution. As a new emerging scanning probe technique, it faces a huge challenge to be widely adopted due to its complexity in fabrication. Here, we report a new simple way of creating diamond tips with tools found in basic clean room facilities and mount the tips onto an experimental apparatus with common lab bench tools. Finally, scanning NV magnetometry was performed to demonstrate its application. This work is supported by the QuASAR project and the Gordon and Betty Moore Foundations EPiQS Initiative through Grant GBMF4531.
Acquisition of Fire Safety Knowledge and Skills With Virtual Reality Simulation.
Rossler, Kelly L; Sankaranarayanan, Ganesh; Duvall, Adrianne
2018-05-25
Prelicensure nursing students seeking to enter perioperative nursing need preparatory fire safety knowledge and skills training to participate as a member of an operating room (OR) team. This pilot study examined the effectiveness of the Virtual Electrosurgery Skill Trainer (VEST) on OR fire safety skills among prelicensure nursing students. An experimental pretest-posttest design was used in this study. Twenty nursing students were randomized to a control or an intervention group. Knowledge and skills acquisition of OR fire safety were assessed. There were no statistically significant findings in knowledge for either group. Fisher exact test demonstrated significant relationships between the skills performance criteria of following emergency procedures for a fire and demonstrating PASS (pull-aim-squeeze-sweep) technique (P = .001). Academic and hospital educators may consider incorporating virtual reality simulation to teach fire safety education or reinforce general fire safety practices to nursing students and novice nurses.
Nanoporous alumina as templates for multifunctional applications
NASA Astrophysics Data System (ADS)
Sousa, C. T.; Leitao, D. C.; Proenca, M. P.; Ventura, J.; Pereira, A. M.; Araujo, J. P.
2014-09-01
Due to its manufacturing and size tailoring ease, porous anodic alumina (PAA) templates are an elegant physical-chemical nanopatterning approach and an emergent alternative to more sophisticated and expensive methods currently used in nanofabrication. In this review, we will describe the ground work on the fabrication methods of PAA membranes and PAA-based nanostructures. We will present the specificities of the electrochemical growth processes of multifunctional nanomaterials with diversified shapes (e.g., nanowires and nanotubes), and the fabrication techniques used to grow ordered nanohole arrays. We will then focus on the fabrication, properties and applications of magnetic nanostructures grown on PAA and illustrate their dependence on internal (diameter, interpore distance, length, composition) and external (temperature and applied magnetic field intensity and direction) parameters. Finally, the most outstanding experimental findings on PAA-grown nanostructures and their trends for technological applications (sensors, energy harvesting, metamaterials, and biotechnology) will be addressed.
Computational resources for ribosome profiling: from database to Web server and software.
Wang, Hongwei; Wang, Yan; Xie, Zhi
2017-08-14
Ribosome profiling is emerging as a powerful technique that enables genome-wide investigation of in vivo translation at sub-codon resolution. The increasing application of ribosome profiling in recent years has achieved remarkable progress toward understanding the composition, regulation and mechanism of translation. This benefits from not only the awesome power of ribosome profiling but also an extensive range of computational resources available for ribosome profiling. At present, however, a comprehensive review on these resources is still lacking. Here, we survey the recent computational advances guided by ribosome profiling, with a focus on databases, Web servers and software tools for storing, visualizing and analyzing ribosome profiling data. This review is intended to provide experimental and computational biologists with a reference to make appropriate choices among existing resources for the question at hand. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
Lockey, D J; Crewdson, K; Davies, G; Jenkins, B; Klein, J; Laird, C; Mahoney, P F; Nolan, J; Pountney, A; Shinde, S; Tighe, S; Russell, M Q; Price, J; Wright, C
2017-03-01
Pre-hospital emergency anaesthesia with oral tracheal intubation is the technique of choice for trauma patients who cannot maintain their airway or achieve adequate ventilation. It should be carried out as soon as safely possible, and performed to the same standards as in-hospital emergency anaesthesia. It should only be conducted within organisations with comprehensive clinical governance arrangements. Techniques should be straightforward, reproducible, as simple as possible and supported by the use of checklists. Monitoring and equipment should meet in-hospital anaesthesia standards. Practitioners need to be competent in the provision of in-hospital emergency anaesthesia and have supervised pre-hospital experience before carrying out pre-hospital emergency anaesthesia. Training programmes allowing the safe delivery of pre-hospital emergency anaesthesia by non-physicians do not currently exist in the UK. Where pre-hospital emergency anaesthesia skills are not available, oxygenation and ventilation should be maintained with the use of second-generation supraglottic airways in patients without airway reflexes, or basic airway manoeuvres and basic airway adjuncts in patients with intact airway reflexes. © 2017 The Authors. Anaesthesia published by John Wiley & Sons Ltd on behalf of Association of Anaesthetists of Great Britain and Ireland.
NASA Astrophysics Data System (ADS)
Khatir, Samir; Dekemele, Kevin; Loccufier, Mia; Khatir, Tawfiq; Abdel Wahab, Magd
2018-02-01
In this paper, a technique is presented for the detection and localization of an open crack in beam-like structures using experimentally measured natural frequencies and the Particle Swarm Optimization (PSO) method. The technique considers the variation in local flexibility near the crack. The natural frequencies of a cracked beam are determined experimentally and numerically using the Finite Element Method (FEM). The optimization algorithm is programmed in MATLAB. The algorithm is used to estimate the location and severity of a crack by minimizing the differences between measured and calculated frequencies. The method is verified using experimentally measured data on a cantilever steel beam. The Fourier transform is adopted to improve the frequency resolution. The results demonstrate the good accuracy of the proposed technique.
Baptista, Fabricio G; Budoya, Danilo E; de Almeida, Vinicius A D; Ulson, Jose Alfredo C
2014-01-10
The electromechanical impedance (EMI) technique is considered to be one of the most promising methods for developing structural health monitoring (SHM) systems. This technique is simple to implement and uses small and inexpensive piezoelectric sensors. However, practical problems have hindered its application to real-world structures, and temperature effects have been cited in the literature as critical problems. In this paper, we present an experimental study of the effect of temperature on the electrical impedance of the piezoelectric sensors used in the EMI technique. We used 5H PZT (lead zirconate titanate) ceramic sensors, which are commonly used in the EMI technique. The experimental results showed that the temperature effects were strongly frequency-dependent, which may motivate future research in the SHM field.
Intermittency and emergence of coherent structures in wave turbulence of a vibrating plate.
Mordant, Nicolas; Miquel, Benjamin
2017-10-01
We report numerical investigations of wave turbulence in a vibrating plate. The possibility to implement advanced measurement techniques and long-time numerical simulations makes this system extremely valuable for wave turbulence studies. The purely 2D character of dynamics of the elastic plate makes it much simpler to handle compared to much more complex 3D physical systems that are typical of geo- and astrophysical issues (ocean surface or internal waves, magnetized plasmas or strongly rotating and/or stratified flows). When the forcing is small the observed wave turbulence is consistent with the predictions of the weak turbulent theory. Here we focus on the case of stronger forcing for which coherent structures can be observed. These structures look similar to the folds and D-cones that are commonly observed for strongly deformed static thin elastic sheets (crumpled paper) except that they evolve dynamically in our forced system. We describe their evolution and show that their emergence is associated with statistical intermittency (lack of self similarity) of strongly nonlinear wave turbulence. This behavior is reminiscent of intermittency in Navier-Stokes turbulence. Experimental data show hints of the weak to strong turbulence transition. However, due to technical limitations and dissipation, the strong nonlinear regime remains out of reach of experiments and therefore has been explored numerically.
Intermittency and emergence of coherent structures in wave turbulence of a vibrating plate
NASA Astrophysics Data System (ADS)
Mordant, Nicolas; Miquel, Benjamin
2017-10-01
We report numerical investigations of wave turbulence in a vibrating plate. The possibility to implement advanced measurement techniques and long-time numerical simulations makes this system extremely valuable for wave turbulence studies. The purely 2D character of dynamics of the elastic plate makes it much simpler to handle compared to much more complex 3D physical systems that are typical of geo- and astrophysical issues (ocean surface or internal waves, magnetized plasmas or strongly rotating and/or stratified flows). When the forcing is small the observed wave turbulence is consistent with the predictions of the weak turbulent theory. Here we focus on the case of stronger forcing for which coherent structures can be observed. These structures look similar to the folds and D-cones that are commonly observed for strongly deformed static thin elastic sheets (crumpled paper) except that they evolve dynamically in our forced system. We describe their evolution and show that their emergence is associated with statistical intermittency (lack of self similarity) of strongly nonlinear wave turbulence. This behavior is reminiscent of intermittency in Navier-Stokes turbulence. Experimental data show hints of the weak to strong turbulence transition. However, due to technical limitations and dissipation, the strong nonlinear regime remains out of reach of experiments and therefore has been explored numerically.
2018-01-01
The “long-life elixir” has long represented for humans a dream, a vanity's sin for remaining young and to long survive. Today, because of ageing population phenomenon, the research of antiageing interventions appears to be more important than ever, for preserving health in old age and retarding/or delaying the onset of age-related diseases. A hope is given by experimental data, which evidence the possibility of retarding ageing in animal models. In addition, it has been also demonstrated in animal life-extending studies not only the possibility of increasing longevity but also the ability to retard the onset of age-related diseases. Interestingly, this recent evidence is leading to promise of obtaining the same effects in humans and resulting in benefits for their health in old ages. In order to achieve this goal, different approaches have been used ranging from pharmacological targeting of ageing, basic biological assays, and big data analysis to the recent use of young blood, stem cells, cellular, genetic, and epigenetic reprogramming, or other techniques of regenerative medicine. However, only a little fraction of these approaches has the features for being tested in clinical applications. Here, new emerging molecules, drugs, and procedures will be described, by evidencing potential benefits and limitations. PMID:29576745
Analysis of Thermo-Diffusive Cellular Instabilities in Continuum Combustion Fronts
NASA Astrophysics Data System (ADS)
Azizi, Hossein; Gurevich, Sebastian; Provatas, Nikolas; Department of Physics, Centre Physics of Materials Team
We explore numerically the morphological patterns of thermo-diffusive instabilities in combustion fronts with a continuum solid fuel source, within a range of Lewis numbers, focusing on the cellular regime. Cellular and dendritic instabilities are found at low Lewis numbers. These are studied using a dynamic adaptive mesh refinement technique that allows very large computational domains, thus allowing us to reduce finite size effects that can affect or even preclude the emergence of these patterns. The distinct types of dynamics found in the vicinity of the critical Lewis number. These types of dynamics are classified as ``quasi-linear'' and characterized by low amplitude cells that may be strongly affected by the mode selection mechanism and growth prescribed by the linear theory. Below this range of Lewis number, highly non-linear effects become prominent and large amplitude, complex cellular and seaweed dendritic morphologies emerge. The cellular patterns simulated in this work are similar to those observed in experiments of flame propagation over a bed of nano-aluminum powder burning with a counter-flowing oxidizer conducted by Malchi et al. It is noteworthy that the physical dimension of our computational domain is roughly close to their experimental setup. This work was supported by a Canadian Space Agency Class Grant ''Percolating Reactive Waves in Particulate Suspensions''. We thank Compute Canada for computing resources.
A Survey of Shape Parameterization Techniques
NASA Technical Reports Server (NTRS)
Samareh, Jamshid A.
1999-01-01
This paper provides a survey of shape parameterization techniques for multidisciplinary optimization and highlights some emerging ideas. The survey focuses on the suitability of available techniques for complex configurations, with suitability criteria based on the efficiency, effectiveness, ease of implementation, and availability of analytical sensitivities for geometry and grids. The paper also contains a section on field grid regeneration, grid deformation, and sensitivity analysis techniques.
Nano-Computed Tomography: Technique and Applications.
Kampschulte, M; Langheinirch, A C; Sender, J; Litzlbauer, H D; Althöhn, U; Schwab, J D; Alejandre-Lafont, E; Martels, G; Krombach, G A
2016-02-01
Nano-computed tomography (nano-CT) is an emerging, high-resolution cross-sectional imaging technique and represents a technical advancement of the established micro-CT technology. Based on the application of a transmission target X-ray tube, the focal spot size can be decreased down to diameters less than 400 nanometers (nm). Together with specific detectors and examination protocols, a superior spatial resolution up to 400 nm (10 % MTF) can be achieved, thereby exceeding the resolution capacity of typical micro-CT systems. The technical concept of nano-CT imaging as well as the basics of specimen preparation are demonstrated exemplarily. Characteristics of atherosclerotic plaques (intraplaque hemorrhage and calcifications) in a murine model of atherosclerosis (ApoE (-/-)/LDLR(-/-) double knockout mouse) are demonstrated in the context of superior spatial resolution in comparison to micro-CT. Furthermore, this article presents the application of nano-CT for imaging cerebral microcirculation (murine), lung structures (porcine), and trabecular microstructure (ovine) in contrast to micro-CT imaging. This review shows the potential of nano-CT as a radiological method in biomedical basic research and discusses the application of experimental, high resolution CT techniques in consideration of other high resolution cross-sectional imaging techniques. Nano-computed tomography is a high resolution CT-technology for 3D imaging at sub-micrometer resolution. The technical concept bases on a further development of the established ex-vivo-micro-CT technology. By improvement of the spatial resolution, structures at a cellular level become visible (e.g. osteocyte lacunae). © Georg Thieme Verlag KG Stuttgart · New York.
Experimental flights using a small unmanned aircraft system for mapping emergent sandbars
Kinzel, Paul J.; Bauer, Mark A.; Feller, Mark R.; Holmquist-Johnson, Christopher; Preston, Todd
2015-01-01
The US Geological Survey and Parallel Inc. conducted experimental flights with the Tarantula Hawk (T-Hawk) unmanned aircraft system (UAS ) at the Dyer and Cottonwood Ranch properties located along reaches of the Platte River near Overton, Nebraska, in July 2013. We equipped the T-Hawk UAS platform with a consumer-grade digital camera to collect imagery of emergent sandbars in the reaches and used photogrammetric software and surveyed control points to generate orthophotographs and digital elevation models (DEMS ) of the reaches. To optimize the image alignment process, we retained and/or eliminated tie points based on their relative errors and spatial resolution, whereby minimizing the total error in the project. Additionally, we collected seven transects that traversed emergent sandbars concurrently with global positioning system location data to evaluate the accuracy of the UAS survey methodology. The root mean square errors for the elevation of emergent points along each transect across the DEMS ranged from 0.04 to 0.12 m. If adequate survey control is established, a UAS combined with photogrammetry software shows promise for accurate monitoring of emergent sandbar morphology and river management activities in short (1–2 km) river reaches.
Masonry structures built with fictile tubules: Experimental and numerical analyses
NASA Astrophysics Data System (ADS)
Tiberti, Simone; Scuro, Carmelo; Codispoti, Rosamaria; Olivito, Renato S.; Milani, Gabriele
2017-11-01
Masonry structures with fictile tubules were a distinctive building technique of the Mediterranean area. This technique dates back to Roman and early Christian times, used to build vaulted constructions and domes with various geometrical forms by virtue of their modular structure. In the present work, experimental tests were carried out to identify the mechanical properties of hollow clay fictile tubules and a possible reinforcing technique for existing buildings employing such elements. The experimental results were then validated by devising and analyzing numerical models with the FE software Abaqus, also aimed at investigating the structural behavior of an arch via linear and nonlinear static analyses.
Emergence of Lying in Very Young Children
ERIC Educational Resources Information Center
Evans, Angela D.; Lee, Kang
2013-01-01
Lying is a pervasive human behavior. Evidence to date suggests that from the age of 42 months onward, children become increasingly capable of telling lies in various social situations. However, there is limited experimental evidence regarding whether very young children will tell lies spontaneously. The present study investigated the emergence of…
Surface Chemistry in Heterogeneous Catalysis: An Emerging Discipline.
ERIC Educational Resources Information Center
White, J. M.; Campbell, Charles T.
1980-01-01
Provides background data on surface chemistry as an emerging discipline. Highlights the important role which surfaces play in catalysis by focusing on the catalyzed oxidation of carbon monoxide. Provides a demonstration of how surfaces exert their influences in heterogeneous phenomena and illustrates how experimental problems in this field are…
Pilot Decision-Making in Irreversible Emergencies
ERIC Educational Resources Information Center
Winter, Scott R.
2013-01-01
The purpose of this study was to determine if a reflexive learning treatment utilizing select case studies could enhance the decision-making of pilots who encounter an irreversible emergency. Participants, who consisted of members of the subject university's professional pilot program, were divided into either a control or experimental group and…
An Experimental Study of the Emergence of Human Communication Systems
ERIC Educational Resources Information Center
Galantucci, Bruno
2005-01-01
The emergence of human communication systems is typically investigated via 2 approaches with complementary strengths and weaknesses: naturalistic studies and computer simulations. This study was conducted with a method that combines these approaches. Pairs of participants played video games requiring communication. Members of a pair were…
Examiner Assessments of Clinical Performance: What Do They Tell Us About Clinical Competence?
ERIC Educational Resources Information Center
Maatsch, Jack L.
1987-01-01
This paper presents and interprets examiner and participant performance data obtained from an experimental field test of the test item and case simulation libraries of the American Board of Emergency Medicine Specialty Certificate Examination. Subjects were 94 medical students, residents, and emergency physicians. (Author/LMO)
Comportement dynamique d'alliages a memoire de forme et application aux composites-AMF
NASA Astrophysics Data System (ADS)
de Santis, Silvio
Meeting current industrial, governmental and international standards regarding vibration and noise levels is a challenging task facing many engineers. These specifications are present in just about all fields of engineering, from aerospace to marine transportation, from automotive to railway transportation, from computer equipment to industrial working environments. An appropriate use of the remarkable properties of high damping metals (HIDAMETS) and shape memory alloy (SMA) reinforced composites emerges as a possible solution to these problems. Among many obstacles to overcome in developing such a technology, the implementation of reliable and adequate characterization techniques to determine dynamic properties of these materials appears to be of prime importance. The research efforts presented in this thesis are aimed at developing advanced techniques to characterize the dynamic behavior of HIDAMETS and SMA reinforced composites. These characterization results lead to the enhancement of numerical (finite element) and/or analytical methods for the simulation of dynamic responses of structures made of these materials. In particular, the research work has focused on three themes: the numerical and experimental validation of applying a characterization procedure developed for traditional composites to SMA reinforced composites; the development of a test bench for uniaxial hysteresis characterization of HIDAMETS in the medium frequency range; the hysteresis characterization and modeling of manganese copper (MnCu) and nickel titanium samples. The results obtained in the course of these efforts show that the characterization technique developed for traditional composites at the University of Brussels is sufficiently precise to successfully predict natural frequencies of complex SMA reinforced composite structures. Using the characterization to predict structural damping ratios, we observe a bias error in the prediction with respect to experimental results although the relative values between modes are consistent. Regarding the development of the test bench for uniaxial hysteresis characterization of HIDAMETS, results suggest that with the introduction of a few minor enhancements and with particular experimental precautions, the test bench can play an important role in characterizing HIDAMETS dynamic properties at various frequencies and strain amplitudes and in understanding micro mechanical mechanisms responsible for energy dissipation. Finally, uniaxial hysteresis loops and related parameters have been obtained with MnCu and NiTi samples. A material model based on dual kriging interpolation that expresses the tangent stiffness along these hysteresis loops as a function of strain and strain amplitude has also been developed.
New International Program to Asses the Reliability of Emerging Nondestructive Techniques (PARENT)
DOE Office of Scientific and Technical Information (OSTI.GOV)
Prokofiev, Iouri; Cumblidge, Stephen E.; Csontos, Aladar A.
2013-01-25
The Nuclear Regulatory Commission (NRC) established the Program to Assess the Reliability of Emerging Nondestructive Techniques (PARENT) to follow on from the successful Program for the Inspection of Nickel alloy Components (PINC). The goal of the PARENT is to conduct a confirmatory assessment of the reliability of nondestructive evaluation (NDE) techniques for detecting and sizing primary water stress corrosion cracks (PWSCC) and applying the lessons learned from PINC to a series of round-robin tests. These open and blind round-robin tests will comprise a new set of typical pressure boundary components including dissimilar metal welds (DMWs) and bottom-mounted instrumentation penetrations. Openmore » round-robin tests will engage research and industry teams worldwide to investigate and demonstrate the reliability of emerging NDE techniques to detect and size flaws with a wide range of lengths, depths, orientations, and locations. Blind round-robin tests will utilize various testing organizations, whose inspectors and procedures are certified by the standards for the nuclear industry in their respective countries, to investigate the ability of established NDE techniques to detect and size flaws whose characteristics range from relatively easy to very difficult for detection and sizing. Blind and open round-robin testing started in late 2011 and early 2012, respectively. This paper will present the work scope with reports on progress, NDE methods evaluated, and project timeline for PARENT.« less
An Unobtrusive System to Measure, Assess, and Predict Cognitive Workload in Real-World Environments
NASA Technical Reports Server (NTRS)
Bracken, Bethany K.; Palmon, Noa; Elkin-Frankston, Seth; Irvin, Scott; Jenkins, Michael; Farry, Mike
2017-01-01
Across many careers, individuals face alternating periods of high and low attention and cognitive workload, which can result in impaired cognitive functioning and can be detrimental to job performance. For example, some professions (e.g., fire fighters, emergency medical personnel, doctors and nurses working in an emergency room, pilots) require long periods of low workload (boredom), followed by sudden, high-tempo operations during which they may be required to respond to an emergency and perform at peak cognitive levels. Conversely, other professions (e.g., air traffic controllers, market investors in financial industries, analysts) require long periods of high workload and multitasking during which the addition of just one more task results in cognitive overload resulting in mistakes. An unobtrusive system to measure, assess, and predict cognitive workload could warn individuals, their teammates, or their supervisors when steps should be taken to augment cognitive readiness. In this talk I will describe an approach to this problem that we have found to be successful across work domains including: (1) a suite of unobtrusive, field-ready neurophysiological, physiological, and behavioral sensors that are chosen to best suit the target environment; (2) custom algorithms and statistical techniques to process and time-align raw data originating from the sensor suite; (3) probabilistic and statistical models designed to interpret the data into the human state of interest (e.g., cognitive workload, attention, fatigue); (4) and machine-learning techniques to predict upcoming performance based on the current pattern of events, and (5) display of each piece of information depending on the needs of the target user who may or may not want to drill down into the functioning of the system to determine how conclusions about human state and performance are determined. I will then focus in on our experimental results from our custom functional near-infrared spectroscopy sensor, designed to operate in real-world environments to be worn comfortably (e.g., positioned into a baseball cap or a surgeons cap) to measure changes in brain blood oxygenation without adding burden to the individual being assessed.
NASA Technical Reports Server (NTRS)
Garmestai, H.; Harris, K.; Lourenco, L.
1997-01-01
Representation of morphology and evolution of the microstructure during processing and their relation to properties requires proper experimental techniques. Residual strains, lattice distortion, and texture (micro-texture) at the interface and the matrix of a layered structure or a functionally gradient material and their variation are among parameters important in materials characterization but hard to measure with present experimental techniques. Current techniques available to measure changes in interred material parameters (residual stress, micro-texture, microplasticity) produce results which are either qualitative or unreliable. This problem becomes even more complicated in the case of a temperature variation. These parameters affect many of the mechanical properties of advanced materials including stress-strain relation, ductility, creep, and fatigue. A review of some novel experimental techniques using recent advances in electron microscopy is presented here to measure internal stress, (micro)texture, interracial strength and (sub)grain formation and realignment. Two of these techniques are combined in the chamber of an Environmental Scanning Electron Microscope to measure strain and orientation gradients in advanced materials. These techniques which include Backscattered Kikuchi Diffractometry (BKD) and Microscopic Strain Field Analysis are used to characterize metallic and intermetallic matrix composites and superplastic materials. These techniques are compared with the more conventional x-ray diffraction and indentation techniques.
2014-12-01
Pre-hospital care, emergency department and critical care medicine are the key components of emergency medical service system. Two investigations about the pediatric critical care medicine in China mainland showed great progress. In recent years, most hospitals in China mainland have established emergency department, hardware configuration and staff status were gradually standardized. But most of the emergency departments mainly provide service to adult patients and pediatric emergency medicine lags behind. The purpose of this investigation was to understand the current situation and main problems of pediatric emergency in China mainland. A questionnaire developed by the Subspecialty Group of Pediatrics, Chinese Society of Emergency Medicine and the Subspecialty Group of Emergency Medicine, Chinese Society of Pediatrics was e-mailed to the members of the above-mentioned two subspecialty groups. The contents of the questionnaire included 46 items which were divided into 5 categories: the general situation of the hospital, the pediatric emergency setting and composition, key equipments and techniques, staff status, training program and running data from 2011 to 2012. Sixty-three questionnaires were delivered and 27 (42.9%) hospitals responded which located in 15 different provinces, municipalities and autonomous regions. Among the 27 hospitals, 10 (37.0%) had no pediatric resuscitation room; 25 (92.6%) had no equipments for cardiac output monitor and gastric lavage; 13 (48.1%) had no bedside fibrolaryngoscope or fiberbronchoscope; 5 (18.5%) had no blood gas analyzer; 4 (14.8%) without respirator, defibrillator, bedside radiography or ultrasonic equipment; 2 (7.4%) had no neonatal incubator; 9 (33.3%) could not do intraossous infusion. The average ratio of professional emergency pediatricians to all physicians was 43.5%. Twenty hospitals incompletely filled in the pediatric emergency running data. The main problems existing in pediatric emergency include: imperfect pediatric emergency settings; short of key equipment; key rescue techniques are not popularized, acute shortage of emergency pediatricians and inadequate monitoring and management of pediatric emergency. The major ways to solve the predicament in pediatric emergency should include: the policy and financial support from national and local government; training pediatricians, especially urgent training of emergency pediatricians; improving pediatric emergency development and management.
Designing smartphone mental health applications for emergency service workers.
Deady, M; Peters, D; Lang, H; Calvo, R; Glozier, N; Christensen, H; Harvey, S B
2017-08-01
Emergency service workers are often exposed to trauma and have increased risk of a range of mental health (MH) conditions. Smartphone applications have the potential to provide this group with effective psychological interventions; however, little is known about the acceptability and preferences regarding such initiatives. To describe the preferences and opinions of emergency service workers regarding the use of smartphone MH applications and to examine the impact of age on these preferences. Participants were recruited from four metropolitan Fire and Rescue NSW stations and responded to questionnaire items covering three key domains: current smartphone use, potential future use and preferences for design and content as well as therapeutic techniques. Overall, approximately half the sample (n = 106) claimed they would be interested in trying a tailored emergency-worker MH smartphone application. There were few differences between age groups on preferences. The majority of respondents claimed they would use an app for mental well-being daily and preferred terms such as 'well-being' and 'mental fitness' for referring to MH. Confidentiality, along with a focus on stress, sleep, exercise and resiliency were all considered key features. Behavioural therapeutic techniques were regarded most favourably, compared with other therapies. Emergency workers were interested in utilizing smartphone applications focused on MH, but expressed clear preferences regarding language used in promotion, features required and therapeutic techniques preferred. © The Author 2017. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com
ERIC Educational Resources Information Center
Wachob, David; Pesci, Louis J.
2017-01-01
In order to best respond to an emergency situation, professionals need to have an understanding about Autism Spectrum Disorder (ASD) and techniques that will ensure proper care. The purpose of this study was to determine the knowledge and confidence of EMS personnel on interacting and treating an individual with ASD. Emergency Medical Technicians…
Lavrik, N V; Taylor, L T; Sepaniak, M J
2011-05-23
Pressure driven liquid chromatography (LC) is a powerful and versatile separation technique particularly suitable for differentiating species present in extremely small quantities. This paper briefly reviews main historical trends and focuses on more recently developed technological approaches in miniaturization and on-chip integration of LC columns. The review emphasizes enabling technologies as well as main technological challenges specific to pressure driven separations and highlights emerging concepts that could ultimately overcome fundamental limitations of conventional LC columns. Copyright © 2011 Elsevier B.V. All rights reserved.
Method and apparatus for determination of mechanical properties of functionally-graded materials
Giannakopoulos, Antonios E.; Suresh, Subra
1999-01-01
Techniques for the determination of mechanical properties of homogenous or functionally-graded materials from indentation testing are presented. The technique is applicable to indentation on the nano-scale through the macro-scale including the geological scale. The technique involves creating a predictive load/depth relationship for a sample, providing an experimental load/depth relationship, comparing the experimental data to the predictive data, and determining a physical characteristic from the comparison.
Code of Federal Regulations, 2011 CFR
2011-10-01
... Purpose. The Emergency Management Training Program is designed to enhance the States' emergency management... give States the opportunity to develop new capabilities and techniques. The Program is an ongoing intergovernmental endeavor which combines financial and human resources to fill the unique training needs of local...
Code of Federal Regulations, 2010 CFR
2010-10-01
... Purpose. The Emergency Management Training Program is designed to enhance the States' emergency management... give States the opportunity to develop new capabilities and techniques. The Program is an ongoing intergovernmental endeavor which combines financial and human resources to fill the unique training needs of local...
A processing centre for the CNES CE-GPS experimentation
NASA Technical Reports Server (NTRS)
Suard, Norbert; Durand, Jean-Claude
1994-01-01
CNES is involved in a GPS (Global Positioning System) geostationary overlay experimentation. The purpose of this experimentation is to test various new techniques in order to select the optimal station synchronization method, as well as the geostationary spacecraft orbitography method. These new techniques are needed to develop the Ranging GPS Integrity Channel services. The CNES experimentation includes three transmitting/receiving ground stations (manufactured by IN-SNEC), one INMARSAT 2 C/L band transponder and a processing center named STE (Station de Traitements de l'Experimentation). Not all the techniques to be tested are implemented, but the experimental system has to include several functions; part of the future system simulation functions, such as a servo-loop function, and in particular a data collection function providing for rapid monitoring of system operation, analysis of existing ground station processes, and several weeks of data coverage for other scientific studies. This paper discusses system architecture and some criteria used in its design, as well as the monitoring function, the approach used to develop a low-cost and short-life processing center in collaboration with a CNES sub-contractor (ATTDATAID), and some results.
Single-Case Experimental Designs: A Systematic Review of Published Research and Current Standards
Smith, Justin D.
2013-01-01
This article systematically reviews the research design and methodological characteristics of single-case experimental design (SCED) research published in peer-reviewed journals between 2000 and 2010. SCEDs provide researchers with a flexible and viable alternative to group designs with large sample sizes. However, methodological challenges have precluded widespread implementation and acceptance of the SCED as a viable complementary methodology to the predominant group design. This article includes a description of the research design, measurement, and analysis domains distinctive to the SCED; a discussion of the results within the framework of contemporary standards and guidelines in the field; and a presentation of updated benchmarks for key characteristics (e.g., baseline sampling, method of analysis), and overall, it provides researchers and reviewers with a resource for conducting and evaluating SCED research. The results of the systematic review of 409 studies suggest that recently published SCED research is largely in accordance with contemporary criteria for experimental quality. Analytic method emerged as an area of discord. Comparison of the findings of this review with historical estimates of the use of statistical analysis indicates an upward trend, but visual analysis remains the most common analytic method and also garners the most support amongst those entities providing SCED standards. Although consensus exists along key dimensions of single-case research design and researchers appear to be practicing within these parameters, there remains a need for further evaluation of assessment and sampling techniques and data analytic methods. PMID:22845874
Magnetic Charge Organization and Screening in Thermalized Artificial Spin Ice
NASA Astrophysics Data System (ADS)
Gilbert, Ian
2014-03-01
Artificial spin ice is a material-by-design in which interacting single-domain ferromagnetic nanoislands are used to model Ising spins in frustrated spin systems. Artificial spin ice has proved a useful system in which to directly probe the physics of geometrical frustration, allowing us to better understand materials such as spin ice. Recently, several new experimental techniques have been developed that allow effective thermalization of artificial spin ice. Given the intense interest in magnetic monopole excitations in spin ice materials and artificial spin ice's success in modeling these materials, it should not come as a surprise that interesting monopole physics emerges here as well. The first experimental investigation of thermalized artificial square spin ice determined that the system's monopole-like excitations obeyed a Boltzmann distribution and also found evidence for monopole-antimonopole interactions. Further experiments have implicated these monopole excitations in the growth of ground state domains. Our recent study of artificial kagome spin ice, whose odd-coordinated vertices always possess a net magnetic charge, has revealed a theoretically-predicted magnetic charge ordering transition which has not been previously observed experimentally. We have also investigated the details of magnetic charge interactions in lattices of mixed coordination number. This work was done in collaboration with Sheng Zhang, Cristiano Nisoli, Gia-Wei Chern, Michael Erickson, Liam O'Brien, Chris Leighton, Paul Lammert, Vincent Crespi, and Peter Schiffer. This work was primarily funded by the US Department of Energy, Office of Basic Energy Sciences, Materials Science and Engineering Division, grant no. DE-SC0005313.