Particular Solutions in Four body problem with solar wind drag

NASA Astrophysics Data System (ADS)

Kumari, Reena; Singh Kushvah, Badam

2012-07-01

To study the motion of a group of celestial objects/bodies interacting with each other under gravitational attraction. We formulated a four body problem with solar wind drag of one radiating body, rotating about their common center of mass with central configuration. We suppose that the governing forces of the motion of four body problems are mutual gravitational attractions of bodies and drag force of radiating body. Firstly, we derive the equations of motion using new co-ordinates for the four body problem. Again, we find the integrals of motions under different cases regarding to the mass of the bodies. Then we find the zero velocity surfaces and particular solutions. Finally, we examined the effect of solar wind drag on the motion of the four body problem. Keywords: Four Body Problem; Particular Solutions; Radiation Force; Zero Velocity Surfaces.

Assessing User Needs and Requirements for Assistive Robots at Home.

PubMed

Werner, Katharina; Werner, Franz

2015-01-01

'Robots in healthcare' is a very trending topic. This paper gives an overview of currently and commonly used methods to gather user needs and requirements in research projects in the field of assistive robotics. Common strategies between authors are presented as well as examples of exceptions, which can help future researchers to find methods suitable for their own work. Typical problems of the field are discussed and partial solutions are proposed.

Supersymmetric solutions of N =(1 ,1 ) general massive supergravity

NASA Astrophysics Data System (ADS)

Deger, N. S.; Nazari, Z.; Sarıoǧlu, Ö.

2018-05-01

We construct supersymmetric solutions of three-dimensional N =(1 ,1 ) general massive supergravity (GMG). Solutions with a null Killing vector are, in general, pp-waves. We identify those that appear at critical points of the model, some of which do not exist in N =(1 ,1 ) new massive supergravity (NMG). In the timelike case, we find that many solutions are common with NMG, but there is a new class that is genuine to GMG, two members of which are stationary Lifshitz and timelike squashed AdS spacetimes. We also show that in addition to the fully supersymmetric AdS vacuum, there is a second AdS background with a nonzero vector field that preserves 1 /4 supersymmetry.

Double power series method for approximating cosmological perturbations

NASA Astrophysics Data System (ADS)

Wren, Andrew J.; Malik, Karim A.

2017-04-01

We introduce a double power series method for finding approximate analytical solutions for systems of differential equations commonly found in cosmological perturbation theory. The method was set out, in a noncosmological context, by Feshchenko, Shkil' and Nikolenko (FSN) in 1966, and is applicable to cases where perturbations are on subhorizon scales. The FSN method is essentially an extension of the well known Wentzel-Kramers-Brillouin (WKB) method for finding approximate analytical solutions for ordinary differential equations. The FSN method we use is applicable well beyond perturbation theory to solve systems of ordinary differential equations, linear in the derivatives, that also depend on a small parameter, which here we take to be related to the inverse wave-number. We use the FSN method to find new approximate oscillating solutions in linear order cosmological perturbation theory for a flat radiation-matter universe. Together with this model's well-known growing and decaying Mészáros solutions, these oscillating modes provide a complete set of subhorizon approximations for the metric potential, radiation and matter perturbations. Comparison with numerical solutions of the perturbation equations shows that our approximations can be made accurate to within a typical error of 1%, or better. We also set out a heuristic method for error estimation. A Mathematica notebook which implements the double power series method is made available online.

Sensitivity-Based Guided Model Calibration

NASA Astrophysics Data System (ADS)

Semnani, M.; Asadzadeh, M.

2017-12-01

A common practice in automatic calibration of hydrologic models is applying the sensitivity analysis prior to the global optimization to reduce the number of decision variables (DVs) by identifying the most sensitive ones. This two-stage process aims to improve the optimization efficiency. However, Parameter sensitivity information can be used to enhance the ability of the optimization algorithms to find good quality solutions in a fewer number of solution evaluations. This improvement can be achieved by increasing the focus of optimization on sampling from the most sensitive parameters in each iteration. In this study, the selection process of the dynamically dimensioned search (DDS) optimization algorithm is enhanced by utilizing a sensitivity analysis method to put more emphasis on the most sensitive decision variables for perturbation. The performance of DDS with the sensitivity information is compared to the original version of DDS for different mathematical test functions and a model calibration case study. Overall, the results show that DDS with sensitivity information finds nearly the same solutions as original DDS, however, in a significantly fewer number of solution evaluations.

Our current approach to root cause analysis: is it contributing to our failure to improve patient safety?

PubMed

Kellogg, Kathryn M; Hettinger, Zach; Shah, Manish; Wears, Robert L; Sellers, Craig R; Squires, Melissa; Fairbanks, Rollin J

2017-05-01

Despite over a decade of efforts to reduce the adverse event rate in healthcare, the rate has remained relatively unchanged. Root cause analysis (RCA) is a process used by hospitals in an attempt to reduce adverse event rates; however, the outputs of this process have not been well studied in healthcare. This study aimed to examine the types of solutions proposed in RCAs over an 8-year period at a major academic medical institution. All state-reportable adverse events were gathered, and those for which an RCA was performed were analysed. A consensus rating process was used to determine a severity rating for each case. A qualitative approach was used to categorise the types of solutions proposed by the RCA team in each case and descriptive statistics were calculated. 302 RCAs were reviewed. The most common event types involved a procedure complication, followed by cardiopulmonary arrest, neurological deficit and retained foreign body. In 106 RCAs, solutions were proposed. A large proportion (38.7%) of RCAs with solutions proposed involved a patient death. Of the 731 proposed solutions, the most common solution types were training (20%), process change (19.6%) and policy reinforcement (15.2%). We found that multiple event types were repeated in the study period, despite repeated RCAs. This study found that the most commonly proposed solutions were weaker actions, which were less likely to decrease event recurrence. These findings support recent attempts to improve the RCA process and to develop guidance for the creation of effective and sustainable solutions to be used by RCA teams. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

FAST TRACK COMMUNICATION: Two interacting atoms in a cavity: exact solutions, entanglement and decoherence

NASA Astrophysics Data System (ADS)

Torres, J. M.; Sadurní, E.; Seligman, T. H.

2010-05-01

We address the problem of two interacting atoms of different species inside a cavity and find the explicit solutions of the corresponding eigenvalues and eigenfunctions using a new variant. This model encompasses various commonly used models. By way of example we obtain closed expressions for concurrence and purity as a function of time for the case where the cavity is prepared in a number state. We discuss the behaviour of these quantities and their relative behaviour in the concurrence-purity plane.

Strengthening Multidisciplinary Research on Climate and Environmental Change

NASA Astrophysics Data System (ADS)

Beer, Tom; Li, Jianping; Alverson, Keith

2014-08-01

The difficulty with multidisciplinary research is finding common ground for scientists, whose approach to a particular scientific problem can differ radically. For example, there is agreement between the geophysical community and the food science and technology community that food security is an important issue. However, the climate change community sees possible solutions coming from more detailed studies on the links between climate change and agriculture, whereas the food science community sees possible solutions emerging from studies of food logistics and supply chains.

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

Han, Cheongho; Jung, Youn Kil; Bennett, David P.

Recently, the discovery of a Venus-mass planet orbiting a brown-dwarf host in a binary system was reported from the analysis of the microlensing event OGLE-2013-BLG-0723. We reanalyze the event considering the possibility of other interpretations. From this, we find a new solution where the lens is composed of two bodies, in contrast to the three-body solution of the previous analysis. The new solution better explains the observed light curve than the previous solution with Δ χ {sup 2} ∼ 202, suggesting that the new solution is a correct model for the event. From the estimation of the physical parameters basedmore » on the new interpretation, we find that the lens system is composed of two low-mass stars with ∼0.2 M {sub ⊙} and ∼0.1 M {sub ⊙} and located at a distance of ∼3 kpc. The fact that the physical parameters correspond to those of the most common lens population located at a distance with a large lensing probability further supports the likelihood of the new interpretation. Considering that two dramatically different solutions can approximately explain the observed light curve, the event suggests the need for carefully testing all possible lens-system geometries.« less

Are You Your Friends' Friend? Poor Perception of Friendship Ties Limits the Ability to Promote Behavioral Change.

PubMed

Almaatouq, Abdullah; Radaelli, Laura; Pentland, Alex; Shmueli, Erez

2016-01-01

Persuasion is at the core of norm creation, emergence of collective action, and solutions to 'tragedy of the commons' problems. In this paper, we show that the directionality of friendship ties affect the extent to which individuals can influence the behavior of each other. Moreover, we find that people are typically poor at perceiving the directionality of their friendship ties and that this can significantly limit their ability to engage in cooperative arrangements. This could lead to failures in establishing compatible norms, acting together, finding compromise solutions, and persuading others to act. We then suggest strategies to overcome this limitation by using two topological characteristics of the perceived friendship network. The findings of this paper have significant consequences for designing interventions that seek to harness social influence for collective action.

Finding common ground in large carnivore conservation: mapping contending perspectives

USGS Publications Warehouse

Mattson, D.J.; Byrd, K.L.; Rutherford, M.B.; Brown, S.R.; Clark, T.W.

2006-01-01

Reducing current conflict over large carnivore conservation and designing effective strategies that enjoy broad public support depend on a better understanding of the values, beliefs, and demands of those who are involved or affected. We conducted a workshop attended by diverse participants involved in conservation of large carnivores in the northern U.S. Rocky Mountains, and used Q methodology to elucidate participant perspectives regarding "problems" and "solutions". Q methodology employs qualitative and quantitative techniques to reveal the subjectivity in any situation. We identified four general perspectives for both problems and solutions, three of which (Carnivore Advocates, Devolution Advocates, and Process Reformers) were shared by participants across domains. Agency Empathizers (problems) and Economic Pragmatists (solutions) were not clearly linked. Carnivore and Devolution Advocates expressed diametrically opposed perspectives that legitimized different sources of policy-relevant information ("science" for Carnivore Advocates and "local knowledge" for Devolution Advocates). Despite differences, we identified potential common ground focused on respectful, persuasive, and creative processes that would build understanding and tolerance. ?? 2006 Elsevier Ltd. All rights reserved.

Comparing IndexedHBase and Riak for Serving Truthy: Performance of Data Loading and Query Evaluation

DTIC Science & Technology

2013-08-01

Research Triangle Park, NC 27709-2211 15. SUBJECT TERMS performance evaluation, distributed database, noSQL , HBase, indexing Xiaoming Gao, Judy Qiu...common hashtags created during a given time window. With the purpose of finding a solution for these challenges, we evaluate NoSQL databases such as

A Fruitful Activity for Finding the Greatest Common Factor

ERIC Educational Resources Information Center

Bell, Carol J.; Leisner, Heather J.; Shelley, Kristina

2011-01-01

Posing mathematics problems in different ways will raise students' level of cognitive demand because it will push them to think more deeply about mathematics. By engaging students in a task that requires them to determine their own solution strategies, students will gain a deeper understanding of the mathematical concept explored through the task.…

Insights into electrodeposition of an inhibitor film and its inhibitive effects on calcium carbonate deposition.

PubMed

Morizot, Arnaud P; Neville, Anne

2002-01-01

Polycarboxylic acid (PAA), a common scale inhibitor has demonstrated adsorption properties on stainless steel surfaces. An electrochemically based technique has been used to assess the extent of film formation. The presence of calcium and magnesium ions in the solution and the cathodic electrochemical activity at the metal surface have been shown to enhance the inhibitor film formation by promoting the transport of the inhibitor from the solution to the metal surface. The effect of the inhibitor film in retarding scale deposition is assessed using measurement of the deposition onto metal electrodes immersed in a supersaturated solution of CaCO(3). The practical implications of these findings are discussed.

Environmental Research Infrastructures providing shared solutions for science and society (ENVRIplus)

NASA Astrophysics Data System (ADS)

Kutsch, Werner Leo; Asmi, Ari; Laj, Paolo; Brus, Magdalena; Sorvari, Sanna

2016-04-01

ENVRIplus is a Horizon 2020 project bringing together Environmental and Earth System Research Infrastructures, projects and networks together with technical specialist partners to create a more coherent, interdisciplinary and interoperable cluster of Environmental Research Infrastructures (RIs) across Europe. The objective of ENVRIplus is to provide common solutions to shared challenges for these RIs in their efforts to deliver new services for science and society. To reach this overall goal, ENVRIplus brings together the current ESFRI roadmap environmental and associate fields RIs, leading I3 projects, key developing RI networks and specific technical specialist partners to build common synergic solutions for pressing issues in RI construction and implementation. ENVRIplus will be organized along 6 main objectives, further on called "Themes": 1) Improve the RI's abilities to observe the Earth System, particularly in developing and testing new sensor technologies, harmonizing observation methodologies and developing methods to overcome common problems associated with distributed remote observation networks; 2) Generate common solutions for shared information technology and data related challenges of the environmental RIs in data and service discovery and use, workflow documentation, data citations methodologies, service virtualization, and user characterization and interaction; 3) Develop harmonized policies for access (physical and virtual) for the environmental RIs, including access services for the multidisciplinary users; 4) Investigate the interactions between RIs and society: Find common approaches and methodologies how to assess the RIs' ability to answer the economical and societal challenges, develop ethics guidelines for RIs and investigate the possibility to enhance the use Citizen Science approaches in RI products and services; 5) Ensure the cross-fertilisation and knowledge transfer of new technologies, best practices, approaches and policies of the RIs by generating training material for RI personnel to use the new observational, technological and computational tools and facilitate inter-RI knowledge transfer via a staff exchange program; 6) Create RI communication and cooperation framework to coordinate activities of the environmental RIs towards common strategic development, improved user interaction and interdisciplinary cross-RI products and services. The produced solutions, services, systems and other project results are made available to all environmental research infrastructure initiatives.

Metabolic bone diseases during long-term total parenteral nutrition.

PubMed

Acca, M; Ragno, A; Francucci, C M; D'Erasmo, E

2007-01-01

Long-term total parenteral nutrition (TPN) is a procedure commonly applied to patients with advanced forms of intestinal malabsorption. Among TPN complications, bone metabolic diseases, such as osteoporosis and osteomalacia, are a common finding. Initially considered to be a manifestation of aluminium toxicity which followed massive contamination with the element of the solutions used in TPN, metabolic osteopathy during TPN is currently considered a multiform syndrome, with a multifactorial pathogenesis, which may manifest itself with vague or clear clinical pictures. In this review, we analyse clinical, pathogenetic, and therapeutic aspects of the most common bone metabolic diseases in patients undergoing long-term TPN.

Solution Structures of Highly Active Molecular Ir Water-Oxidation Catalysts from Density Functional Theory Combined with High-Energy X-ray Scattering and EXAFS Spectroscopy.

PubMed

Yang, Ke R; Matula, Adam J; Kwon, Gihan; Hong, Jiyun; Sheehan, Stafford W; Thomsen, Julianne M; Brudvig, Gary W; Crabtree, Robert H; Tiede, David M; Chen, Lin X; Batista, Victor S

2016-05-04

The solution structures of highly active Ir water-oxidation catalysts are elucidated by combining density functional theory, high-energy X-ray scattering (HEXS), and extended X-ray absorption fine structure (EXAFS) spectroscopy. We find that the catalysts are Ir dimers with mono-μ-O cores and terminal anionic ligands, generated in situ through partial oxidation of a common catalyst precursor. The proposed structures are supported by (1)H and (17)O NMR, EPR, resonance Raman and UV-vis spectra, electrophoresis, etc. Our findings are particularly valuable to understand the mechanism of water oxidation by highly reactive Ir catalysts. Importantly, our DFT-EXAFS-HEXS methodology provides a new in situ technique for characterization of active species in catalytic systems.

Short-Term Faculty Members: A National Dilemma and a Local Solution.

ERIC Educational Resources Information Center

Killingsworth, M. Jimmie; And Others

1989-01-01

Surveys English department chairs nationwide, examining the status of full-time non-tenure-track teachers in English departments of PhD-granting institutions. Finds that universities commonly hire short-term lecturers to teach when regular faculty members are "too expensive" for the job. Reports a plan adopted by Texas Tech University to deal with…

Contextualizing Mathematics Related Affect: Significance of Students' Individual and Social Level Affect in Finland and Chile

ERIC Educational Resources Information Center

Tuohilampi, Laura

2016-01-01

Mathematics related affect turn from positive to negative during comprehensive school years worldwide. There is a clear need to find solutions to the problem. However, some gaps and problems appear in the methodologies and the common approaches used in the field. This article discusses five studies addressing affective development, challenges some…

Noisy Spins and the Richardson-Gaudin Model

NASA Astrophysics Data System (ADS)

Rowlands, Daniel A.; Lamacraft, Austen

2018-03-01

We study a system of spins (qubits) coupled to a common noisy environment, each precessing at its own frequency. The correlated noise experienced by the spins implies long-lived correlations that relax only due to the differing frequencies. We use a mapping to a non-Hermitian integrable Richardson-Gaudin model to find the exact spectrum of the quantum master equation in the high-temperature limit and, hence, determine the decay rate. Our solution can be used to evaluate the effect of inhomogeneous splittings on a system of qubits coupled to a common bath.

Inorganic and Protein Crystal Assembly in Solutions

NASA Technical Reports Server (NTRS)

Chernov, A. A.

2005-01-01

The basic kinetic and thermodynamic concepts of crystal growth will be revisited in view of recent AFM and interferometric findings. These concepts are as follows: 1) The Kossel crystal model that allows only one kink type on the crystal surface. The modern theory is developed overwhelmingly for the Kessel model; 2) Presumption that intensive step fluctuations maintain kink density sufficiently high to allow applicability of Gibbs-Thomson law; 3) Common experience that unlimited step bunching (morphological instability) during layer growth from solutions and supercooled melts always takes place if the step flow direction coincides with that of the fluid.

Probing pH difference between micellar solution and nanoscale water within common black film by fluorescent dye

NASA Astrophysics Data System (ADS)

Fu, Jingni; Zhang, Luning

2018-03-01

The protonation/deprotonation equilibrium of a fluorescent pH probe (carboxy-seminaphthorhodafluor-1, SNARF-1) within the nanoscale water layer confined in common black films (CBFs) has been studied. We find that SNARF-1 molecules feel a more acidic environment in CBFs than when they are in the bulk micellar solution, using the base/acid peak area ratio of the dye to indicate its microenvironment pH. Three surfactants are used to study the dependence of the pH drop versus charge: cationic (cetyltrimethylammonium bromide, CTAB), anionic (sodium dodecylsulphate, SDS) and nonionic (Triton X-100) species. The decrease of CBFs pH versus the pH of the micellar solution is the following: ΔpH ≈ 1.5 for CTAB (pH: 7.0-9.0), ΔpH ≈ 0.8 for SDS, and ΔpH ≈ 0.4 for Triton X-100. With the addition of electrolyte in CBFs, we observe large decrease the amplitude of the pH anomaly, thus suggesting an electrostatic origin of the pH change at nanoscale environment.

Finding Common Ground: Creating the Library of the Future without Diminishing the Library of the Past. The New Library Series.

ERIC Educational Resources Information Center

LaGuardia, Cheryl, Ed.; Mitchell, Barbara A., Ed.

Adapting today's libraries to better serve tomorrow's needs challenges even the most forward-thinking library staff. This book offers practical, workable solutions from several authorities in the industry. Fifty-five conference papers are included and divided into the following subject areas: "Technology and the Network: Daimons or Demons?";…

Multiple stakeholders in multi-criteria decision-making in the context of Municipal Solid Waste Management: A review.

PubMed

Soltani, Atousa; Hewage, Kasun; Reza, Bahareh; Sadiq, Rehan

2015-01-01

Municipal Solid Waste Management (MSWM) is a complicated process that involves multiple environmental and socio-economic criteria. Decision-makers look for decision support frameworks that can guide in defining alternatives, relevant criteria and their weights, and finding a suitable solution. In addition, decision-making in MSWM problems such as finding proper waste treatment locations or strategies often requires multiple stakeholders such as government, municipalities, industries, experts, and/or general public to get involved. Multi-criteria Decision Analysis (MCDA) is the most popular framework employed in previous studies on MSWM; MCDA methods help multiple stakeholders evaluate the often conflicting criteria, communicate their different preferences, and rank or prioritize MSWM strategies to finally agree on some elements of these strategies and make an applicable decision. This paper reviews and brings together research on the application of MCDA for solving MSWM problems with more focus on the studies that have considered multiple stakeholders and offers solutions for such problems. Results of this study show that AHP is the most common approach in consideration of multiple stakeholders and experts and governments/municipalities are the most common participants in these studies. Copyright © 2014 Elsevier Ltd. All rights reserved.

Eco-analytical Methodology in Environmental Problems Monitoring

NASA Astrophysics Data System (ADS)

Agienko, M. I.; Bondareva, E. P.; Chistyakova, G. V.; Zhironkina, O. V.; Kalinina, O. I.

2017-01-01

Among the problems common to all mankind, which solutions influence the prospects of civilization, the problem of ecological situation monitoring takes very important place. Solution of this problem requires specific methodology based on eco-analytical comprehension of global issues. Eco-analytical methodology should help searching for the optimum balance between environmental problems and accelerating scientific and technical progress. The fact that Governments, corporations, scientists and nations focus on the production and consumption of material goods cause great damage to environment. As a result, the activity of environmentalists is developing quite spontaneously, as a complement to productive activities. Therefore, the challenge posed by the environmental problems for the science is the formation of geo-analytical reasoning and the monitoring of global problems common for the whole humanity. So it is expected to find the optimal trajectory of industrial development to prevent irreversible problems in the biosphere that could stop progress of civilization.

Capacitive touch sensing : signal and image processing algorithms

NASA Astrophysics Data System (ADS)

Baharav, Zachi; Kakarala, Ramakrishna

2011-03-01

Capacitive touch sensors have been in use for many years, and recently gained center stage with the ubiquitous use in smart-phones. In this work we will analyze the most common method of projected capacitive sensing, that of absolute capacitive sensing, together with the most common sensing pattern, that of diamond-shaped sensors. After a brief introduction to the problem, and the reasons behind its popularity, we will formulate the problem as a reconstruction from projections. We derive analytic solutions for two simple cases: circular finger on a wire grid, and square finger on a square grid. The solutions give insight into the ambiguities of finding finger location from sensor readings. The main contribution of our paper is the discussion of interpolation algorithms including simple linear interpolation , curve fitting (parabolic and Gaussian), filtering, general look-up-table, and combinations thereof. We conclude with observations on the limits of the present algorithmic methods, and point to possible future research.

Characterization of Nanoparticles and Colloids in Aquatic Systems 1. Small Angle Neutron Scattering Investigations of Suwannee River Fulvic Acid Aggregates in Aqueous Solutions

NASA Astrophysics Data System (ADS)

Diallo, Mamadou S.; Glinka, Charles J.; Goddard, William A.; Johnson, James H.

2005-10-01

Fulvic acids (FA) and humic acids (HA) constitute 30-50% of dissolved organic matter in natural aquatic systems. In aqueous solutions, a commonly accepted view is that FA and HA exist as soluble macroligands at low concentration and as supramolecular aggregates at higher concentration. The size, shape and structure of these aggregates are still the subject of ongoing debate in the environmental chemistry literature. In this article, we use small angle neutron scattering (SANS) to assess the effects of solute concentration, solution pH and background electrolyte (NaCl) concentration on the structures of Suwannee River FA (SRFA) aggregates in D2O. The qualitative features of the SANS curves and data analysis are not consistent with the view point that SRFA forms micelle-like aggregates as its concentration in aqueous solution increases. We find that SRFA forms fractal aggregates in D20 with size greater than 242 nm. The SRFA aggregates undergo a significant degree of restructuring in compactness as solution pH, solute concentration and NaCl concentration increase.

Multistate outbreak of toxic anterior segment syndrome, 2005.

PubMed

Kutty, Preeta K; Forster, Terri S; Wood-Koob, Carol; Thayer, Nancy; Nelson, Robert B; Berke, Stanley J; Pontacolone, Lillian; Beardsley, Thomas L; Edelhauser, Henry F; Arduino, Matthew J; Mamalis, Nick; Srinivasan, Arjun

2008-04-01

To present the findings of an outbreak of toxic anterior segment syndrome (TASS). Six states, 7 ophthalmology surgical centers, United States. Cases were identified through electronic communication networks and via reports to a national TASS referral center. Information on the procedure, details of instrument reprocessing, and products used during cataract surgery were also collected. Medications used during the procedures were tested for endotoxin using a kinetic assay. The search identified 112 case patients (median age 74 years) from 7 centers from July 19, 2005, through November 28, 2005. Common presenting clinical features included blurred vision (60%), anterior segment inflammation (49%), and cell deposition (56%). Of the patients, 100 (89%) had been exposed to a single brand of balanced salt solution manufactured by Cytosol Laboratories and distributed by Advanced Medical Optics as AMO Endosol. Two patients continued to have residual symptoms. There were no reports of significant breaches in sterile technique or instrument reprocessing. Of 14 balanced salt solution lots, 5 (35%) had levels exceeding the endotoxin limit (0.5 EU/mL). Based on these findings, the balanced salt solution product was withdrawn, resulting in a termination of the outbreak. This is the first known report of an outbreak of TASS caused by intrinsic contamination of a product with endotoxin. Ophthalmologists and epidemiologists should be aware of TASS and its common causes. To facilitate investigations of adverse outcomes such as TASS, those performing cataract surgeries should document the type and lot numbers of products used intraoperatively.

Common and Innovative Visuals: A sparsity modeling framework for video.

PubMed

Abdolhosseini Moghadam, Abdolreza; Kumar, Mrityunjay; Radha, Hayder

2014-05-02

Efficient video representation models are critical for many video analysis and processing tasks. In this paper, we present a framework based on the concept of finding the sparsest solution to model video frames. To model the spatio-temporal information, frames from one scene are decomposed into two components: (i) a common frame, which describes the visual information common to all the frames in the scene/segment, and (ii) a set of innovative frames, which depicts the dynamic behaviour of the scene. The proposed approach exploits and builds on recent results in the field of compressed sensing to jointly estimate the common frame and the innovative frames for each video segment. We refer to the proposed modeling framework by CIV (Common and Innovative Visuals). We show how the proposed model can be utilized to find scene change boundaries and extend CIV to videos from multiple scenes. Furthermore, the proposed model is robust to noise and can be used for various video processing applications without relying on motion estimation and detection or image segmentation. Results for object tracking, video editing (object removal, inpainting) and scene change detection are presented to demonstrate the efficiency and the performance of the proposed model.

On the Oxidation State of Manganese Ions in Li-Ion Battery Electrolyte Solutions.

PubMed

Banerjee, Anjan; Shilina, Yuliya; Ziv, Baruch; Ziegelbauer, Joseph M; Luski, Shalom; Aurbach, Doron; Halalay, Ion C

2017-02-08

We demonstrate herein that Mn 3+ and not Mn 2+ , as commonly accepted, is the dominant dissolved manganese cation in LiPF 6 -based electrolyte solutions of Li-ion batteries with lithium manganate spinel positive and graphite negative electrodes chemistry. The Mn 3+ fractions in solution, derived from a combined analysis of electron paramagnetic resonance and inductively coupled plasma spectroscopy data, are ∼80% for either fully discharged (3.0 V hold) or fully charged (4.2 V hold) cells, and ∼60% for galvanostatically cycled cells. These findings agree with the average oxidation state of dissolved Mn ions determined from X-ray absorption near-edge spectroscopy data, as verified through a speciation diagram analysis. We also show that the fractions of Mn 3+ in the aprotic nonaqueous electrolyte solution are constant over the duration of our experiments and that disproportionation of Mn 3+ occurs at a very slow rate.

Predicting vacancy-mediated diffusion of interstitial solutes in α -Fe

NASA Astrophysics Data System (ADS)

Barouh, Caroline; Schuler, Thomas; Fu, Chu-Chun; Jourdan, Thomas

2015-09-01

Based on a systematic first-principles study, the lowest-energy migration mechanisms and barriers for small vacancy-solute clusters (VnXm ) are determined in α -Fe for carbon, nitrogen, and oxygen, which are the most frequent interstitial solutes in several transition metals. We show that the dominant clusters present at thermal equilibrium (V X and V X2 ) have very reduced mobility compared to isolated solutes, while clusters composed of a solute bound to a small vacancy cluster may be significantly more mobile. In particular, V3X is found to be the fastest cluster for all three solutes. This result relies on the large diffusivity of the most compact trivacancy in a bcc lattice. Therefore, it may also be expected for interstitial solutes in other bcc metals. In the case of iron, we find that V3X may be as fast as or even more mobile than an interstitial solute. At variance with common assumptions, the trapping of interstitial solutes by vacancies does not necessarily decrease the mobility of the solute. Additionally, cluster dynamics simulations are performed considering a simple iron system with supersaturation of vacancies, in order to investigate the impacts of small mobile vacancy-solute clusters on properties such as the transport of solute and the cluster size distributions.

What about False Insights? Deconstructing the Aha! Experience along Its Multiple Dimensions for Correct and Incorrect Solutions Separately

PubMed Central

Danek, Amory H.; Wiley, Jennifer

2017-01-01

The subjective Aha! experience that problem solvers often report when they find a solution has been taken as a marker for insight. If Aha! is closely linked to insightful solution processes, then theoretically, an Aha! should only be experienced when the correct solution is found. However, little work has explored whether the Aha! experience can also accompany incorrect solutions (“false insights”). Similarly, although the Aha! experience is not a unitary construct, little work has explored the different dimensions that have been proposed as its constituents. To address these gaps in the literature, 70 participants were presented with a set of difficult problems (37 magic tricks), and rated each of their solutions for Aha! as well as with regard to Suddenness in the emergence of the solution, Certainty of being correct, Surprise, Pleasure, Relief, and Drive. Solution times were also used as predictors for the Aha! experience. This study reports three main findings: First, false insights exist. Second, the Aha! experience is multidimensional and consists of the key components Pleasure, Suddenness and Certainty. Third, although Aha! experiences for correct and incorrect solutions share these three common dimensions, they are also experienced differently with regard to magnitude and quality, with correct solutions emerging faster, leading to stronger Aha! experiences, and higher ratings of Pleasure, Suddenness, and Certainty. Solution correctness proffered a slightly different emotional coloring to the Aha! experience, with the additional perception of Relief for correct solutions, and Surprise for incorrect ones. These results cast some doubt on the assumption that the occurrence of an Aha! experience can serve as a definitive signal that a true insight has taken place. On the other hand, the quantitative and qualitative differences in the experience of correct and incorrect solutions demonstrate that the Aha! experience is not a mere epiphenomenon. Strong Aha! experiences are clearly, but not exclusively linked to correct solutions. PMID:28163687

What about False Insights? Deconstructing the Aha! Experience along Its Multiple Dimensions for Correct and Incorrect Solutions Separately.

PubMed

Danek, Amory H; Wiley, Jennifer

2016-01-01

The subjective Aha! experience that problem solvers often report when they find a solution has been taken as a marker for insight. If Aha! is closely linked to insightful solution processes, then theoretically, an Aha! should only be experienced when the correct solution is found. However, little work has explored whether the Aha! experience can also accompany incorrect solutions ("false insights"). Similarly, although the Aha! experience is not a unitary construct, little work has explored the different dimensions that have been proposed as its constituents. To address these gaps in the literature, 70 participants were presented with a set of difficult problems (37 magic tricks), and rated each of their solutions for Aha! as well as with regard to Suddenness in the emergence of the solution, Certainty of being correct, Surprise, Pleasure, Relief, and Drive. Solution times were also used as predictors for the Aha! This study reports three main findings: First, false insights exist. Second, the Aha! experience is multidimensional and consists of the key components Pleasure, Suddenness and Certainty. Third, although Aha! experiences for correct and incorrect solutions share these three common dimensions, they are also experienced differently with regard to magnitude and quality, with correct solutions emerging faster, leading to stronger Aha! experiences, and higher ratings of Pleasure, Suddenness, and Certainty. Solution correctness proffered a slightly different emotional coloring to the Aha! experience, with the additional perception of Relief for correct solutions, and Surprise for incorrect ones. These results cast some doubt on the assumption that the occurrence of an Aha! experience can serve as a definitive signal that a true insight has taken place. On the other hand, the quantitative and qualitative differences in the experience of correct and incorrect solutions demonstrate that the Aha! experience is not a mere epiphenomenon. Strong Aha! experiences are clearly, but not exclusively linked to correct solutions.

The air-bubble method of locking central-vein catheters with acidified, concentrated sodium chloride as a bactericidal agent: in vitro studies.

PubMed

Moore, Harold L; Twardowski, Zbylut J

2003-10-01

Soft, cuffed indwelling catheters are used for hemodialysis access and intravenous infusions. The majority of these catheters are removed as a result of infection caused by contamination of the catheter hub during the connection/disconnection procedures. To prevent clot formation in the lumen, these catheters are routinely "locked" with heparin or some other anticoagulant. None of the anticoagulants commonly used as locking solutions demonstrates any significant bactericidal properties. The primary goal of this study was the development of a catheter locking method that retains anticoagulant properties at the catheter tip and bactericidal properties at the catheter hub. The second goal was to find a solution that possesses excellent bactericidal properties but is not detrimental in the event of injection into the patient's blood stream. The bactericidal properties of acidified, concentrated saline (ACS) were compared to concentrated trisodium citrate and to commonly used bactericidal agents such as povidone iodine, sodium hypochlorite, and chlorhexidine. In preliminary studies, the rate of diffusion of solutes was measured in glass tubes. In another set of experiments, the mixing of two solutions (anticoagulant and bactericide) separated by an air bubble ("air-bubble method") was observed in stationary and moving systems. The final series of studies compared the bactericidal properties of ACS to other bactericidal solutions mentioned above. The solutions diffused swiftly in the glass tubes, and by the third day, both solutions were mixed. The air-bubble method prevented mixing in both stationary and moving systems. The bactericidal properties of ACS were superior to all other tested solutions. The proposed method of catheter locking with anticoagulant at the catheter tip and ACS at the catheter hub separated by an air bubble is a promising technique and clinical studies are warranted.

Block Architecture Problem with Depth First Search Solution and Its Application

NASA Astrophysics Data System (ADS)

Rahim, Robbi; Abdullah, Dahlan; Simarmata, Janner; Pranolo, Andri; Saleh Ahmar, Ansari; Hidayat, Rahmat; Napitupulu, Darmawan; Nurdiyanto, Heri; Febriadi, Bayu; Zamzami, Z.

2018-01-01

Searching is a common process performed by many computer users, Raita algorithm is one algorithm that can be used to match and find information in accordance with the patterns entered. Raita algorithm applied to the file search application using java programming language and the results obtained from the testing process of the file search quickly and with accurate results and support many data types.

"Two Souls, Alas, Reside within My Breast": Reflections on German and American Music Education Regarding the Internationalization of Music Education

ERIC Educational Resources Information Center

Kertz-Welzel, Alexandra

2013-01-01

In recent years, the internationalization of music education has become an important topic. Scholars of various research traditions try to find the best solutions for problems in music education theory and practice by taking a look at what other countries do. English as common language seems to facilitate this recent development. However, in spite…

Numerical modeling of pollutant transport using a Lagrangian marker particle technique

NASA Technical Reports Server (NTRS)

Spaulding, M.

1976-01-01

A derivation and code were developed for the three-dimensional mass transport equation, using a particle-in-cell solution technique, to solve coastal zone waste discharge problems where particles are a major component of the waste. Improvements in the particle movement techniques are suggested and typical examples illustrated. Preliminary model comparisons with analytic solutions for an instantaneous point release in a uniform flow show good results in resolving the waste motion. The findings to date indicate that this computational model will provide a useful technique to study the motion of sediment, dredged spoils, and other particulate waste commonly deposited in coastal waters.

Common Ground on Climate Change: Pairing Opposing Viewpoints for Conversations about Climate Change

NASA Astrophysics Data System (ADS)

Kirk, K. B.; Duggan-Haas, D.; Hayhoe, K.

2017-12-01

In American public discourse, people tend to strongly identify with the viewpoints held by their cultural and political tribes. However, entrenched positions do little to advance understanding, or work toward solving problems constructively. Worse yet, it has become commonplace to dismiss or demonize those coming from a different point of view - leading to the vitriolic stalemate that often characterizes social media and comment threads when it comes to climate change. One way to break this pattern is to invite people with opposing opinions to actually talk to one another. This presentation describes the lessons learned during the Common Ground on Climate Change project, in which people with contrasting views about climate change engage in a moderated interview with each other. Prior to the interview, participants complete a set of values-based questions. The goal is to reveal areas of common ground between apparent opposites, such as a sense of stewardship for Earth's resources, or an opinion that solutions to climate change will be more beneficial than harmful. The structure of the interviews is based on the hypothesis that if a conversation begins with an appreciation of common values, it becomes easier to broach areas of disagreement. Participants are matched up in one-on-one moderated interviews where they are encouraged to share their concerns, ideas, and priorities about the validity of climate science, the need for urgent action, and the types of solutions they find most tenable. Emerging themes from this series of interviews include the value of a diversity of outlooks, and the ability for moderated conversations to find surprising areas of agreement. Articles about the interviews also appear on the Yale Climate Connections website, https://www.yaleclimateconnections.org/author/karin/.

Next Space Race is in IT

NASA Technical Reports Server (NTRS)

Alger, George; Santiago, S. Scott (Technical Monitor)

2001-01-01

The next Space Race will be in the economic applications from space and science technology. As NASA science and technology has global application; IT is global, economics is global; surely there are great untapped potentials in finding the IT links of commonality among these three. The Economics of IT will continue to depend upon solution providers creating new methods that capitalize on linking information and information centers with the applications community for business and economic functions.. New and innovative IT vendors whose increased efforts to apply evolving technologies and principles that power the e-business revolution are now seeing the business of government being transformed in a similar fashion. NASA will be a prime example of IT transformation. Potential benefits of e-government are identical to the benefits of e-commerce, which start from value derived from capabilities and assets. The capability and asset wealth of NASA technology and data mass scattered through hundreds of archives will one day provide incredible economic benefit across international and corporate boundaries. Yet the ability to economically benefit from bridging the gap between capability to billable service has yet to find it's first major market. Ultimately the role of government, science, and technology linking to the business world will find greater dependence from this increasingly common ground of IT solutions and technologies. Therefore the future role of the IT industry may be as much administrative as technical, ultimately of critical importance furthering the role of science into application.

A visual analysis of multi-attribute data using pixel matrix displays

NASA Astrophysics Data System (ADS)

Hao, Ming C.; Dayal, Umeshwar; Keim, Daniel; Schreck, Tobias

2007-01-01

Charts and tables are commonly used to visually analyze data. These graphics are simple and easy to understand, but charts show only highly aggregated data and present only a limited number of data values while tables often show too many data values. As a consequence, these graphics may either lose or obscure important information, so different techniques are required to monitor complex datasets. Users need more powerful visualization techniques to digest and compare detailed multi-attribute data to analyze the health of their business. This paper proposes an innovative solution based on the use of pixel-matrix displays to represent transaction-level information. With pixelmatrices, users can visualize areas of importance at a glance, a capability not provided by common charting techniques. We present our solutions to use colored pixel-matrices in (1) charts for visualizing data patterns and discovering exceptions, (2) tables for visualizing correlations and finding root-causes, and (3) time series for visualizing the evolution of long-running transactions. The solutions have been applied with success to product sales, Internet network performance analysis, and service contract applications demonstrating the benefits of our method over conventional graphics. The method is especially useful when detailed information is a key part of the analysis.

Multiple stakeholders in multi-criteria decision-making in the context of Municipal Solid Waste Management: A review

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

Soltani, Atousa; Hewage, Kasun; Reza, Bahareh

2015-01-15

Highlights: • We review Municipal Solid Waste Management studies with focus on multiple stakeholders. • We focus on studies with multi-criteria decision analysis methods and discover their trends. • Most studies do not offer solutions for situations where stakeholders compete for more benefits or have unequal voting powers. • Governments and experts are the most participated stakeholders and AHP is the most dominant method. - Abstract: Municipal Solid Waste Management (MSWM) is a complicated process that involves multiple environmental and socio-economic criteria. Decision-makers look for decision support frameworks that can guide in defining alternatives, relevant criteria and their weights, andmore » finding a suitable solution. In addition, decision-making in MSWM problems such as finding proper waste treatment locations or strategies often requires multiple stakeholders such as government, municipalities, industries, experts, and/or general public to get involved. Multi-criteria Decision Analysis (MCDA) is the most popular framework employed in previous studies on MSWM; MCDA methods help multiple stakeholders evaluate the often conflicting criteria, communicate their different preferences, and rank or prioritize MSWM strategies to finally agree on some elements of these strategies and make an applicable decision. This paper reviews and brings together research on the application of MCDA for solving MSWM problems with more focus on the studies that have considered multiple stakeholders and offers solutions for such problems. Results of this study show that AHP is the most common approach in consideration of multiple stakeholders and experts and governments/municipalities are the most common participants in these studies.« less

Optimality versus stability in water resource allocation.

PubMed

Read, Laura; Madani, Kaveh; Inanloo, Bahareh

2014-01-15

Water allocation is a growing concern in a developing world where limited resources like fresh water are in greater demand by more parties. Negotiations over allocations often involve multiple groups with disparate social, economic, and political status and needs, who are seeking a management solution for a wide range of demands. Optimization techniques for identifying the Pareto-optimal (social planner solution) to multi-criteria multi-participant problems are commonly implemented, although often reaching agreement for this solution is difficult. In negotiations with multiple-decision makers, parties who base decisions on individual rationality may find the social planner solution to be unfair, thus creating a need to evaluate the willingness to cooperate and practicality of a cooperative allocation solution, i.e., the solution's stability. This paper suggests seeking solutions for multi-participant resource allocation problems through an economics-based power index allocation method. This method can inform on allocation schemes that quantify a party's willingness to participate in a negotiation rather than opt for no agreement. Through comparison of the suggested method with a range of distance-based multi-criteria decision making rules, namely, least squares, MAXIMIN, MINIMAX, and compromise programming, this paper shows that optimality and stability can produce different allocation solutions. The mismatch between the socially-optimal alternative and the most stable alternative can potentially result in parties leaving the negotiation as they may be too dissatisfied with their resource share. This finding has important policy implications as it justifies why stakeholders may not accept the socially optimal solution in practice, and underlies the necessity of considering stability where it may be more appropriate to give up an unstable Pareto-optimal solution for an inferior stable one. Authors suggest assessing the stability of an allocation solution as an additional component to an analysis that seeks to distribute water in a negotiated process. Copyright © 2013 Elsevier Ltd. All rights reserved.

Psychometric properties of the Body Checking Questionnaire in college women.

PubMed

White, Emily K; Claudat, Kim; Jones, Sarah C; Barchard, Kimberly A; Warren, Cortney S

2015-03-01

While the Body Checking Questionnaire (BCQ; Reas et al., 2002) is the most commonly-used measure of body checking behaviors, findings on the factor structure in nonclinical samples are mixed. This study investigated the factor structure and psychometric properties of the BCQ among nonclinical college women. In Study 1 (n=326), an exploratory factor analysis indicated factors corresponding to (a) behavioral and (b) visual checking. In Study 2 (n=1013), a confirmatory factor analysis revealed adequate fit for these factors, better than the original or total score solutions. Scales based upon the two factors demonstrated good internal consistency, convergent validity with measures of eating pathology, and sensitivity for detecting at-risk eating pathology. Results suggest an alternate two-factor solution that differs from the original three-factor solution. Copyright © 2015. Published by Elsevier Ltd.

Verbal problem solving in high functioning autistic individuals.

PubMed

Minshew, N J; Siegel, D J; Goldstein, G; Weldy, S

1994-01-01

The verbal problem-solving and abstract reasoning ability of 25 high-functioning autistic individuals ages 11 to 41 was compared with normal controls individually matched on age, gender, race, IQ, and educational level. The Twenty Questions Procedure was administered using a grid of 42 common objects. Time to complete the task, number of correct solutions, and number and type of questions asked were analyzed. Results indicated that controls were more often successful in achieving solutions, and in formulating constraint seeking questions that conceptually grouped, ordered, and sorted the objects. In contrast, the autistics relied primarily on guessing. Findings are consistent with prior studies reporting a core deficit in autism involving abstract reasoning ability.

Solving the linear inviscid shallow water equations in one dimension, with variable depth, using a recursion formula

NASA Astrophysics Data System (ADS)

Hernandez-Walls, R.; Martín-Atienza, B.; Salinas-Matus, M.; Castillo, J.

2017-11-01

When solving the linear inviscid shallow water equations with variable depth in one dimension using finite differences, a tridiagonal system of equations must be solved. Here we present an approach, which is more efficient than the commonly used numerical method, to solve this tridiagonal system of equations using a recursion formula. We illustrate this approach with an example in which we solve for a rectangular channel to find the resonance modes. Our numerical solution agrees very well with the analytical solution. This new method is easy to use and understand by undergraduate students, so it can be implemented in undergraduate courses such as Numerical Methods, Lineal Algebra or Differential Equations.

Graft preservation solutions in cardiovascular surgery.

PubMed

Winkler, Bernhard; Reineke, David; Heinisch, Paul Philip; Schönhoff, Florian; Huber, Christoph; Kadner, Alexander; Englberger, Lars; Carrel, Thierry

2016-08-01

Vein grafts are still the most commonly used graft material in cardiovascular surgery and much effort has been spent in recent years on investigating the optimal harvesting technique. One other related topic of similar importance remained more or less an incidental one. The storage solutions of vein grafts following procurement and prior to implantation are, despite their assumed impact, a relatively neglected theme. There is no doubt that the endothelium plays a key role in long-term patency of vein grafts, but the effects of the different storage solutions on the endothelium remain unclear : In a review of the literature, we could find 20 specific papers that addressed the question, of which the currently available preservation solutions are superior, harmless, damaging or ineffective. The focus lies on saline and autologous whole blood. Besides these two storage media, novel or alternative solutions have been investigated with surprising findings. In addition, a few words will be spent on potential alternatives and novel solutions on the market. As there is currently no randomized clinical trial regarding saline versus autologous whole blood available, this review compares all previous studies and methods of analysis to provide a certain level of evidence on this topic. In summary, saline has negative effects on the endothelial layers and therefore may compromise graft patency. Related factors, such as distension pressure, may outbalance the initial benefit of autologous whole blood or storage solutions and intensify the harmful effects of warm saline. In addition, there is no uniform consent on the superiority of autologous whole blood for vein graft storage. This may open the door to alternatives such as the University of Wisconsin solution or one of the specific designed storage solutions like TiProtec™ or Somaluthion™. Whether these preservation solutions are superior or advantageous remains the subject of further studies. © The Author 2016. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Managing wilderness recreation use: common problems and potential solutions

Treesearch

David N. Cole; Margaret E. Petersen; Robert C. Lucas

1987-01-01

Describes pros and cons of potential solutions to common wilderness recreation problems. Covers the purpose of each potential solution, costs to visitors and management, effectiveness, other considerations, and sources of additional information.

Building Common Ground for Environmental Flows using Traditional Techniques and Novel Engagement Approaches.

PubMed

Mott Lacroix, Kelly E; Xiu, Brittany C; Megdal, Sharon B

2016-04-01

Despite increased understanding of the science of environmental flows, identification and implementation of effective environmental flow policies remains elusive. Perhaps the greatest barrier to implementing flow policies is the framework for water management. An alternative management approach is needed when legal rights for environmental flows do not exist, or are ineffective at protecting ecosystems. The research presented here, conducted in the U.S. state of Arizona, provides an empirical example of engagement to promote social learning as an approach to finding ways to provide water for the environment where legal rights for environmental flows are inadequate. Based on our engagement process we propose that identifying and then building common ground require attention to the process of analyzing qualitative data and the methods for displaying complex information, two aspects not frequently discussed in the social learning or stakeholder engagement literature. The results and methods from this study can help communities develop an engagement process that will find and build common ground, increase stakeholder involvement, and identify innovative solutions to provide water for the environment that reflect the concerns of current water users.

Using MD simulations to calculate how solvents modulate solubility

PubMed Central

Liu, Shuai; Cao, Shannon; Hoang, Kevin; Young, Kayla L.; Paluch, Andrew S.; Mobley, David L.

2016-01-01

Here, our interest is in predicting solubility in general, and we focus particularly on predicting how the solubility of particular solutes is modulated by the solvent environment. Solubility in general is extremely important, both for theoretical reasons – it provides an important probe of the balance between solute-solute and solute-solvent interactions – and for more practical reasons, such as how to control the solubility of a given solute via modulation of its environment, as in process chemistry and separations. Here, we study how the change of solvent affects the solubility of a given compound. That is, we calculate relative solubilities. We use MD simulations to calculate relative solubility and compare our calculated values with experiment as well as with results from several other methods, SMD and UNIFAC, the latter of which is commonly used in chemical engineering design. We find that straightforward solubility calculations based on molecular simulations using a general small-molecule force field outperform SMD and UNIFAC both in terms of accuracy and coverage of the relevant chemical space. PMID:26878198

Biomimetic Branched Hollow Fibers Templated by Self-assembled Fibrous Polyvinylpyrrolidone (PVP) Structures in Aqueous Solution

PubMed Central

Qiu, Penghe; Mao, Chuanbin

2010-01-01

Branched hollow fibers are common in nature, but to form artificial fibers with a similar branched hollow structure is still a challenge. We discovered that polyvinylpyrrolidone (PVP) could self-assemble into branched hollow fibers in an aqueous solution after aging the PVP solution for about two weeks. Based on this finding, we demonstrated two approaches by which the self-assembly of PVP into branched hollow fibers could be exploited to template the formation of branched hollow inorganic fibers. First, inorganic material such as silica with high affinity against the PVP could be deposited on the surface of the branched hollow PVP fibers to form branched hollow silica fibers. To extend the application of PVP self-assembly in templating the formation of hollow branched fibers, we then adopted a second approach where the PVP molecules bound to inorganic nanoparticles (using gold nanoparticles as a model) co-self-assemble with the free PVP molecules in an aqueous solution, resulting in the formation of the branched hollow fibers with the nanoparticles embedded in the PVP matrix constituting the walls of the fibers. Heating the resultant fibers above the glass transition temperature of PVP led to the formation of branched hollow gold fibers. Our work suggests that the self-assembly of the PVP molecules in the solution can serve as a general method for directing the formation of branched hollow inorganic fibers. The branched hollow fibers may find potential applications in microfluidics, artificial blood vessel generation, and tissue engineering. PMID:20158250

Important nonurgent imaging findings: use of a hybrid digital and administrative support tool for facilitating clinician communication.

PubMed

Johnson, Evan; Sanger, Joseph; Rosenkrantz, Andrew B

2015-01-01

A departmental tool that provides a digital/administrative solution for communication of important imaging findings was evaluated. The tool allows the radiologist to click a button to mark an examination for ordering physician follow-up with subsequent fax and confirmation. The tool's log was reviewed. Of 466 entries; 99.4% were successfully faxed with phone confirmation. Most common reasons for usage were lung nodule/mass (29.2%) and osseous fracture (12.4%). Subsequent clinical action was documented in 41.0% of entries. Our data show the reliability of the tool in assisting the communication of findings, as well as providing documentation of notification, with minimal workflow disruption. Copyright © 2015 Elsevier Inc. All rights reserved.

Vasoactive intestinal polypeptide (VIP) innervation of the human eyelid glands.

PubMed

Seifert, P; Spitznas, M

1999-06-01

This study was conducted to obtain morphological proof of innervating nerve fibres in the glands of the human eyelid (accessory lacrimal glands of Wolfring, meibomian glands, goblet cells, glands of Zeis, glands of Moll, sweat glands, glands of lanugo hair follicles) and identification of the secretomotorically active neuropeptide vasoactive intestinal polypeptide (VIP) as a common transmitter. Epoxy-embedded ultrathin sections of tissue samples from human eyelids were studied using electron microscopy. Paraffin sections fixed in Bouin-Hollande solution were immunostained with rabbit antiserum against VIP. With the electron microscope we were able to identify nerves in the glandular stroma of all the glands examined with the exception of goblet cells. Intraepithelial single axons were only seen in the parenchyma of Wolfring glands. The morphological findings corresponded with the immunological finding of VIP-positive, nerve-like structures in the same locations, with the exception of lanugo hair follicle glands, and goblet cells. Our findings indicate that the glands of the eyelids and main lacrimal gland represent a functional unit with VIP as a possible common stimulating factor. Copyright 1999 Academic Press.

Multimicrometer Noncovalent Monolayer Domains on Layered Materials through Thermally Controlled Langmuir-Schaefer Conversion for Noncovalent 2D Functionalization.

PubMed

Hayes, Tyler R; Bang, Jae Jin; Davis, Tyson C; Peterson, Caroline F; McMillan, David G; Claridge, Shelley A

2017-10-18

As functionalized 2D materials are incorporated into hybrid materials, ensuring large-area structural control in noncovalently adsorbed films becomes increasingly important. Noncovalent functionalization avoids disrupting electronic structure in 2D materials; however, relatively weak molecular interactions in such monolayers typically reduce stability toward solution processing and other common material handling conditions. Here, we find that controlling substrate temperature during Langmuir-Schaefer conversion of a standing phase monolayer of diynoic amphiphiles on water to a horizontally oriented monolayer on a 2D substrate routinely produces multimicrometer domains, at least an order of magnitude larger than those typically achieved through drop-casting. Following polymerization, these highly ordered monolayers retain their structures during vigorous washing with solvents including water, ethanol, tetrahydrofuran, and toluene. These findings point to a convenient and broadly applicable strategy for noncovalent functionalization of 2D materials in applications that require large-area structural control, for instance, to minimize desorption at defects during subsequent solution processing.

Time-dependent transport of energetic particles in magnetic turbulence: computer simulations versus analytical theory

NASA Astrophysics Data System (ADS)

Arendt, V.; Shalchi, A.

2018-06-01

We explore numerically the transport of energetic particles in a turbulent magnetic field configuration. A test-particle code is employed to compute running diffusion coefficients as well as particle distribution functions in the different directions of space. Our numerical findings are compared with models commonly used in diffusion theory such as Gaussian distribution functions and solutions of the cosmic ray Fokker-Planck equation. Furthermore, we compare the running diffusion coefficients across the mean magnetic field with solutions obtained from the time-dependent version of the unified non-linear transport theory. In most cases we find that particle distribution functions are indeed of Gaussian form as long as a two-component turbulence model is employed. For turbulence setups with reduced dimensionality, however, the Gaussian distribution can no longer be obtained. It is also shown that the unified non-linear transport theory agrees with simulated perpendicular diffusion coefficients as long as the pure two-dimensional model is excluded.

A methodology for commonality analysis, with applications to selected space station systems

NASA Technical Reports Server (NTRS)

Thomas, Lawrence Dale

1989-01-01

The application of commonality in a system represents an attempt to reduce costs by reducing the number of unique components. A formal method for conducting commonality analysis has not been established. In this dissertation, commonality analysis is characterized as a partitioning problem. The cost impacts of commonality are quantified in an objective function, and the solution is that partition which minimizes this objective function. Clustering techniques are used to approximate a solution, and sufficient conditions are developed which can be used to verify the optimality of the solution. This method for commonality analysis is general in scope. It may be applied to the various types of commonality analysis required in the conceptual, preliminary, and detail design phases of the system development cycle.

How do retired paramedics fit into remote, rural emergency departments?

PubMed

Eisenman, A

2013-01-01

The reluctance of physicians to stay in remote and rural hospitals has resulted in a shortage of doctors in these settings, and therefore a decline in the quality of care and an intolerable overload on functioning doctors. However, mature paramedics find it difficult to comply with the demands of ambulance work and look for easier tasks that suit their age. The two problems may have a common solution if senior paramedics are incorporated into in-hospital work. Paramedics' skills, education and experience enable them to become useful physician assistants who may relieve much of the doctors' burden, allowing physicians in remote hospitals to concentrate on genuine medical duties. However, the objection of doctors' and nurses' professional organizations constitute a substantial obstacle to this solution.

Black hole algorithm for determining model parameter in self-potential data

NASA Astrophysics Data System (ADS)

Sungkono; Warnana, Dwa Desa

2018-01-01

Analysis of self-potential (SP) data is increasingly popular in geophysical method due to its relevance in many cases. However, the inversion of SP data is often highly nonlinear. Consequently, local search algorithms commonly based on gradient approaches have often failed to find the global optimum solution in nonlinear problems. Black hole algorithm (BHA) was proposed as a solution to such problems. As the name suggests, the algorithm was constructed based on the black hole phenomena. This paper investigates the application of BHA to solve inversions of field and synthetic self-potential (SP) data. The inversion results show that BHA accurately determines model parameters and model uncertainty. This indicates that BHA is highly potential as an innovative approach for SP data inversion.

A simple and low-cost chip bonding solution for high pressure, high temperature and biological applications.

PubMed

Serra, M; Pereiro, I; Yamada, A; Viovy, J-L; Descroix, S; Ferraro, D

2017-02-14

The sealing of microfluidic devices remains a complex and time-consuming process requiring specific equipment and protocols: a universal method is thus highly desirable. We propose here the use of a commercially available sealing tape as a robust, versatile, reversible solution, compatible with cell and molecular biology protocols, and requiring only the application of manually achievable pressures. The performance of the seal was tested with regards to the most commonly used chip materials. For most materials, the bonding resisted 5 bars at room temperature and 1 bar at 95 °C. This method should find numerous uses, ranging from fast prototyping in the laboratory to implementation in low technology environments or industrial production.

Statistical process control charts for attribute data involving very large sample sizes: a review of problems and solutions.

PubMed

Mohammed, Mohammed A; Panesar, Jagdeep S; Laney, David B; Wilson, Richard

2013-04-01

The use of statistical process control (SPC) charts in healthcare is increasing. The primary purpose of SPC is to distinguish between common-cause variation which is attributable to the underlying process, and special-cause variation which is extrinsic to the underlying process. This is important because improvement under common-cause variation requires action on the process, whereas special-cause variation merits an investigation to first find the cause. Nonetheless, when dealing with attribute or count data (eg, number of emergency admissions) involving very large sample sizes, traditional SPC charts often produce tight control limits with most of the data points appearing outside the control limits. This can give a false impression of common and special-cause variation, and potentially misguide the user into taking the wrong actions. Given the growing availability of large datasets from routinely collected databases in healthcare, there is a need to present a review of this problem (which arises because traditional attribute charts only consider within-subgroup variation) and its solutions (which consider within and between-subgroup variation), which involve the use of the well-established measurements chart and the more recently developed attribute charts based on Laney's innovative approach. We close by making some suggestions for practice.

The influence of surface friction on the AA2024 microstructure

NASA Astrophysics Data System (ADS)

Eliseev, A. A.; Kolubaev, E. A.; Fortuna, S. V.

2017-12-01

This work is devoted to the study of the effect of sliding at velocities close to those achieved during friction stir welding or friction drilling on the microstructural evolution of 2024 aluminum alloy. The distribution of both solid solution grains and intermetallic precipitates is analyzed. No layers of recrystallized grains depleted by precipitates, which is a common finding in FSW or friction drilling, are found below the worn surface independently of the sliding velocity. A small precipitate content and size changes alone are observed.

Quantum algorithm for linear systems of equations.

PubMed

Harrow, Aram W; Hassidim, Avinatan; Lloyd, Seth

2009-10-09

Solving linear systems of equations is a common problem that arises both on its own and as a subroutine in more complex problems: given a matrix A and a vector b(-->), find a vector x(-->) such that Ax(-->) = b(-->). We consider the case where one does not need to know the solution x(-->) itself, but rather an approximation of the expectation value of some operator associated with x(-->), e.g., x(-->)(dagger) Mx(-->) for some matrix M. In this case, when A is sparse, N x N and has condition number kappa, the fastest known classical algorithms can find x(-->) and estimate x(-->)(dagger) Mx(-->) in time scaling roughly as N square root(kappa). Here, we exhibit a quantum algorithm for estimating x(-->)(dagger) Mx(-->) whose runtime is a polynomial of log(N) and kappa. Indeed, for small values of kappa [i.e., poly log(N)], we prove (using some common complexity-theoretic assumptions) that any classical algorithm for this problem generically requires exponentially more time than our quantum algorithm.

Status of the effectiveness of contact lens disinfectants in Malaysia against keratitis-causing pathogens.

PubMed

Abjani, Farhat; Khan, Naveed Ahmed; Jung, Suk Yul; Siddiqui, Ruqaiyyah

2017-12-01

The aim of this study was (i) to assess the antimicrobial effects of contact lens disinfecting solutions marketed in Malaysia against common bacterial eye pathogens and as well as eye parasite, Acanthamoeba castellanii, and (ii) to determine whether targeting cyst wall would improve the efficacy of contact lens disinfectants. Using ISO 14729 Stand-Alone Test for disinfecting solutions, bactericidal and amoebicidal assays of six different contact lens solutions including Oxysept ® , AO SEPT PLUS, OPTI-FREE ® pure moist ® , Renu ® fresh™, FreshKon ® CLEAR and COMPLETE RevitaLens™ were performed using Manufacturers Minimum recommended disinfection time (MRDT). The efficacy of contact lens solutions was determined against keratitis-causing microbes, namely: Pseudomonas aeruginosa, Methicillin-resistant Staphylococcus aureus, Streptococcus pyogenes, Streptococcus pneumoniae, and Acanthamoeba castellanii. In addition, using chlorhexidine as an antiamoebic compound and cellulase enzyme to disrupt cyst wall structure, we determined whether combination of both agents can enhance efficacy of marketed contact lens disinfectants against A. castellanii trophozoites and cysts, in vitro. The results revealed that all contact lens disinfectants tested showed potent bactericidal effects exhibiting 100% kill against all bacterial species tested. In contrast, none of the contact lens disinfectants had potent effects against Acanthamoeba cysts viability. When tested against trophozoites, two disinfectants, Oxysept Multipurpose and AO-sept Multipurpose showed partial amoebicidal effects. Using chlorhexidine as an antiamoebic compound and cellulase enzyme to disrupt cyst wall structure, the findings revealed that combination of both agents in contact lens disinfectants abolished viability of A. castellanii cysts and trophozoites. Given the inefficacy of contact lens disinfectants tested in this study, these findings present a significant concern to public health. These findings revealed that targeting cyst wall by using cyst wall degrading molecules in contact lens disinfecting solutions will enhance their efficacy against this devastating eye infection. Copyright © 2017 Elsevier Inc. All rights reserved.

Collaborative Help in Chronic Disease Management: Supporting Individualized Problems

PubMed Central

Huh, Jina; Ackerman, Mark S.

2013-01-01

Coping with chronic illness disease is a long and lonely journey, because the burden of managing the illness on a daily basis is placed upon the patients themselves. In this paper, we present our findings for how diabetes patient support groups help one another find individualized strategies for managing diabetes. Through field observations of face-to-face diabetes support groups, content analysis of an online diabetes community, and interviews, we found several help interactions that are critical in helping patients in finding individualized solutions. Those are: (1) patients operationalize their experiences to easily contextualize and share executable strategies; (2) operationalization has to be done within the larger context of sharing illness trajectories; and (3) the support groups develop common understanding towards diabetes management. We further discuss how our findings translate into design implications for supporting chronic illness patients in online community settings. PMID:25360442

Cryoprotectant redistribution along the frozen straw probed by Raman spectroscopy.

PubMed

Karpegina, Yu A; Okotrub, K A; Brusentsev, E Yu; Amstislavsky, S Ya; Surovtsev, N V

2016-04-01

The distribution of cryoprotectant (10% glycerol) and ice along the frozen plastic straw (the most useful container for freezing mammalian semen, oocytes and embryos) was studied by Raman scattering technique. Raman spectroscopy being a contactless, non-invasive tool was applied for the straws filled with the cryoprotectant solution and frozen by controlled rate programs commonly used for mammalian embryos freezing. Analysis of Raman spectra measured at different points along the straw reveals a non-uniform distribution of the cryoprotectant. The ratio between non-crystalline solution and ice was found to be increased by several times at the bottom side of the solution column frozen by the standard freezing program. The increase of the cryoprotectant fraction occurs in the area where embryos or oocytes are normally placed during their freezing. Possible effects of the cooling rate and the ice nucleation temperature on the cryoprotectant fraction at the bottom side of the solution column were considered. Our findings highlight that the ice fraction around cryopreserved embryos or oocytes can differ significantly from the averaged one in the frozen plastic straws. Copyright © 2016 Elsevier Inc. All rights reserved.

Surmounting the unique challenges in health disparities education: a multi-institution qualitative study.

PubMed

Carter-Pokras, Olivia; Bereknyei, Sylvia; Lie, Desiree; Braddock, Clarence H

2010-05-01

The National Consortium for Multicultural Education for Health Professionals (Consortium) comprises educators representing 18 US medical schools, funded by the National Institutes of Health. Collective lessons learned from curriculum implementation by principal investigators (PIs) have the potential to guide similar educational endeavors. Describe Consortium PI's self-reported challenges with curricular development, solutions and their new curricular products. Information was collected from PIs over 2 months using a 53-question structured three-part questionnaire. The questionnaire addressed PI demographics, curriculum implementation challenges and solutions, and newly created curricular products. Study participants were 18 Consortium PIs. Descriptive analysis was used for quantitative data. Narrative responses were analyzed and interpreted using qualitative thematic coding. Response rate was 100%. Common barriers and challenges identified by PIs were: finding administrative and leadership support, sustaining the momentum, continued funding, finding curricular space, accessing and engaging communities, and lack of education research methodology skills. Solutions identified included engaging stakeholders, project-sharing across schools, advocacy and active participation in committees and community, and seeking sustainable funding. All Consortium PIs reported new curricular products and extensive dissemination efforts outside their own institutions. The Consortium model has added benefits for curricular innovation and dissemination for cultural competence education to address health disparities. Lessons learned may be applicable to other educational innovation efforts.

Subjective Theories of Indonesian Agronomy and Biology Teacher Students on Environmental Commons Dilemmas

ERIC Educational Resources Information Center

Koch, Sebastian; Barkmann, Jan; Sundawati, Leti; Bogeholz, Susanne

2013-01-01

Fostering the cognitive skills to analyse environmental "commons dilemmas" is an urgent task of environmental education globally. Commons dilemmas are characterised by structural incentives to overexploit a natural resource; their solution is particularly pressing in threatened biodiversity "hotspot" areas. Solutions to these…

A Study to Identify the Critical Success Factors for ERP Implementation in an Indian SME: A Case Based Approach

NASA Astrophysics Data System (ADS)

Upadhyay, Parijat; Dan, Pranab K.

To achieve synergy across product lines, businesses are implementing a set of standard business applications and consistent data definitions across all business units. ERP packages are extremely useful in integrating a global company and provide a "common language" throughout the company. Companies are not only implementing a standardized application but is also moving to a common architecture and infrastructure. For many companies, a standardized software rollout is a good time to do some consolidation of their IT infrastructure across various locations. Companies are also finding that the ERP solutions help them get rid of their legacy systems, most of which may not be compliant with the modern day business requirements.

A speciation solver for cement paste modeling and the semismooth Newton method

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

Georget, Fabien, E-mail: fabieng@princeton.edu; Prévost, Jean H., E-mail: prevost@princeton.edu; Vanderbei, Robert J., E-mail: rvdb@princeton.edu

2015-02-15

The mineral assemblage of a cement paste may vary considerably with its environment. In addition, the water content of a cement paste is relatively low and the ionic strength of the interstitial solution is often high. These conditions are extreme conditions with respect to the common assumptions made in speciation problem. Furthermore the common trial and error algorithm to find the phase assemblage does not provide any guarantee of convergence. We propose a speciation solver based on a semismooth Newton method adapted to the thermodynamic modeling of cement paste. The strong theoretical properties associated with these methods offer practical advantages.more » Results of numerical experiments indicate that the algorithm is reliable, robust, and efficient.« less

Soil solution phosphorus turnover: derivation, interpretation, and insights from a global compilation of isotope exchange kinetic studies

NASA Astrophysics Data System (ADS)

Helfenstein, Julian; Jegminat, Jannes; McLaren, Timothy I.; Frossard, Emmanuel

2018-01-01

The exchange rate of inorganic phosphorus (P) between the soil solution and solid phase, also known as soil solution P turnover, is essential for describing the kinetics of bioavailable P. While soil solution P turnover (Km) can be determined by tracing radioisotopes in a soil-solution system, few studies have done so. We believe that this is due to a lack of understanding on how to derive Km from isotopic exchange kinetic (IEK) experiments, a common form of radioisotope dilution study. Here, we provide a derivation of calculating Km using parameters obtained from IEK experiments. We then calculated Km for 217 soils from published IEK experiments in terrestrial ecosystems, and also that of 18 long-term P fertilizer field experiments. Analysis of the global compilation data set revealed a negative relationship between concentrations of soil solution P and Km. Furthermore, Km buffered isotopically exchangeable P in soils with low concentrations of soil solution P. This finding was supported by an analysis of long-term P fertilizer field experiments, which revealed a negative relationship between Km and phosphate-buffering capacity. Our study highlights the importance of calculating Km for understanding the kinetics of P between the soil solid and solution phases where it is bioavailable. We argue that our derivation can also be used to calculate soil solution turnover of other environmentally relevant and strongly sorbing elements that can be traced with radioisotopes, such as zinc, cadmium, nickel, arsenic, and uranium.

Between the quills: Schopenhauer and Freud on sadism and masochism.

PubMed

Grimwade, Robert

2011-02-01

It is a matter of common knowledge that Sigmund Freud (1856-1939) and Arthur Schopenhauer (1788-1860) shared a common worldview. Everyone familiar with the works of these two thinkers should recognize their general philosophical affinities. Both men were pessimistic about the power of human reason and attributed human behavior to powerful unconscious forces and, as a result, both were deeply skeptical about the future of human society. Drawing from previous literature, this essay compares the philosophical theory of Schopenhauer with the psychoanalytic theory of Freud. We find that, while Schopenhauer and Freud share a common philosophical orientation and diagnosed the same fundamental problems with life in civilization, they proposed some ostensibly similar, yet ultimately very different solutions. Focusing on each thinker's respective notion of sadism and masochism, this paper tries to understand and come to terms with the dimensions of this radical pessimism. Copyright © 2011 Institute of Psychoanalysis.

Generalization of Solovev’s approach to finding equilibrium solutions for axisymmetric plasmas with flow

NASA Astrophysics Data System (ADS)

M, S. CHU; Yemin, HU; Wenfeng, GUO

2018-03-01

Solovev’s approach of finding equilibrium solutions was found to be extremely useful for generating a library of linear-superposable equilibria for the purpose of shaping studies. This set of solutions was subsequently expanded to include the vacuum solutions of Zheng, Wootton and Solano, resulting in a set of functions {SOLOVEV_ZWS} that were usually used for all toroidally symmetric plasmas, commonly recognized as being able to accommodate any desired plasma shapes (complete-shaping capability). The possibility of extending the Solovev approach to toroidal equilibria with a general plasma flow is examined theoretically. We found that the only meaningful extension is to plasmas with a pure toroidal rotation and with a constant Mach number. We also show that the simplification ansatz made to the current profiles, which was the basis of the Solovev approach, should be applied more systematically to include an internal boundary condition at the magnetic axis; resulting in a modified and more useful set {SOLOVEV_ZWSm}. Explicit expressions of functions in this set are given for equilibria with a quasi-constant current density profile, with a toroidal flow at a constant Mach number and with specific heat capacity 1. The properties of {SOLOVEV_ZWSm} are studied analytically. Numerical examples of achievable equilibria are demonstrated. Although the shaping capability of the set {SOLOVE_ZWSm} is quite extensive, it nevertheless still does not have complete shaping capability, particularly for plasmas with negative curvature points on the plasma boundary such as the doublets or indented bean shaped tokamaks.

Food applications of natural antimicrobial compounds.

PubMed

Lucera, Annalisa; Costa, Cristina; Conte, Amalia; Del Nobile, Matteo A

2012-01-01

In agreement with the current trend of giving value to natural and renewable resources, the use of natural antimicrobial compounds, particularly in food and biomedical applications, becomes very frequent. The direct addition of natural compounds to food is the most common method of application, even if numerous efforts have been made to find alternative solutions to the aim of avoiding undesirable inactivation. Dipping, spraying, and coating treatment of food with active solutions are currently applied to product prior to packaging as valid options. The aim of the current work is to give an overview on the use of natural compounds in food sector. In particular, the review will gather numerous case-studies of meat, fish, dairy products, minimally processed fruit and vegetables, and cereal-based products where these compounds found application.

Food applications of natural antimicrobial compounds

PubMed Central

Lucera, Annalisa; Costa, Cristina; Conte, Amalia; Del Nobile, Matteo A.

2012-01-01

In agreement with the current trend of giving value to natural and renewable resources, the use of natural antimicrobial compounds, particularly in food and biomedical applications, becomes very frequent. The direct addition of natural compounds to food is the most common method of application, even if numerous efforts have been made to find alternative solutions to the aim of avoiding undesirable inactivation. Dipping, spraying, and coating treatment of food with active solutions are currently applied to product prior to packaging as valid options. The aim of the current work is to give an overview on the use of natural compounds in food sector. In particular, the review will gather numerous case-studies of meat, fish, dairy products, minimally processed fruit and vegetables, and cereal-based products where these compounds found application. PMID:23060862

SLTCAP: A Simple Method for Calculating the Number of Ions Needed for MD Simulation.

PubMed

Schmit, Jeremy D; Kariyawasam, Nilusha L; Needham, Vince; Smith, Paul E

2018-04-10

An accurate depiction of electrostatic interactions in molecular dynamics requires the correct number of ions in the simulation box to capture screening effects. However, the number of ions that should be added to the box is seldom given by the bulk salt concentration because a charged biomolecule solute will perturb the local solvent environment. We present a simple method for calculating the number of ions that requires only the total solute charge, solvent volume, and bulk salt concentration as inputs. We show that the most commonly used method for adding salt to a simulation results in an effective salt concentration that is too high. These findings are confirmed using simulations of lysozyme. We have established a web server where these calculations can be readily performed to aid simulation setup.

Rapid carbon mineralization for permanent disposal of anthropogenic carbon dioxide emissions

NASA Astrophysics Data System (ADS)

Matter, Juerg M.; Stute, Martin; Snæbjörnsdottir, Sandra Ó.; Oelkers, Eric H.; Gislason, Sigurdur R.; Aradottir, Edda S.; Sigfusson, Bergur; Gunnarsson, Ingvi; Sigurdardottir, Holmfridur; Gunnlaugsson, Einar; Axelsson, Gudni; Alfredsson, Helgi A.; Wolff-Boenisch, Domenik; Mesfin, Kiflom; Taya, Diana Fernandez de la Reguera; Hall, Jennifer; Dideriksen, Knud; Broecker, Wallace S.

2016-06-01

Carbon capture and storage (CCS) provides a solution toward decarbonization of the global economy. The success of this solution depends on the ability to safely and permanently store CO2. This study demonstrates for the first time the permanent disposal of CO2 as environmentally benign carbonate minerals in basaltic rocks. We find that over 95% of the CO2 injected into the CarbFix site in Iceland was mineralized to carbonate minerals in less than 2 years. This result contrasts with the common view that the immobilization of CO2 as carbonate minerals within geologic reservoirs takes several hundreds to thousands of years. Our results, therefore, demonstrate that the safe long-term storage of anthropogenic CO2 emissions through mineralization can be far faster than previously postulated.

Solubility of lysozyme in the presence of aqueous chloride salts: common-ion effect and its role on solubility and crystal thermodynamics.

PubMed

Annunziata, Onofrio; Payne, Andrew; Wang, Ying

2008-10-08

Understanding protein solubility is important for a rational design of the conditions of protein crystallization. We report measurements of lysozyme solubility in aqueous solutions as a function of NaCl, KCl, and NH4Cl concentrations at 25 degrees C and pH 4.5. Our solubility results are directly compared to preferential-interaction coefficients of these ternary solutions determined in the same experimental conditions by ternary diffusion. This comparison has provided new important insight on the dependence of protein solubility on salt concentration. We remark that the dependence of the preferential-interaction coefficient as a function of salt concentration is substantially shaped by the common-ion effect. This effect plays a crucial role also on the observed behavior of lysozyme solubility. We find that the dependence of solubility on salt type and concentration strongly correlates with the corresponding dependence of the preferential-interaction coefficient. Examination of both preferential-interaction coefficients and second virial coefficients has allowed us to demonstrate that the solubility dependence on salt concentration is substantially affected by the corresponding change of protein chemical potential in the crystalline phase. We propose a simple model for the crystalline phase based on salt partitioning between solution and the hydrated protein crystal. A novel solubility equation is reported that quantitatively explains the observed experimental dependence of protein solubility on salt concentration.

Crystallization of probucol from solution and the glassy state.

PubMed

Kawakami, Kohsaku; Ohba, Chie

2017-01-30

Crystallization of probucol (PBL) from both solution and glassy solid state was investigated. In the crystallization study from solution, six solvents and three methods, i.e., evaporation, addition of a poor solvent, and cooling on ice, were used to obtain various crystal forms. In addition to common two crystal forms (forms I and II), two further forms (forms III and cyclohexane-solvate) were found in this study, and their thermodynamic relationships were determined. Forms I and II are likely to be enantiotropically related with thermodynamic transition temperature below 5°C. Isothermal crystallization studies revealed that PBL glass initially crystallized into form III between 25 and 50°C, and then transformed to form I. The isothermal crystallization appears to be a powerful option to find uncommon crystal forms. The crystallization of PBL was identified to be pressure controlled, thus the physical stability of PBL glass is higher than that of typical compounds. Copyright © 2016 Elsevier B.V. All rights reserved.

Solution-Focused Wellness: A Randomized Controlled Trial of College Students.

PubMed

Beauchemin, James D

2018-05-01

Heightened stress levels and compromised well-being are common among college students. Current trends on college campuses include an increase in the number of students experiencing mental health issues and an increase in students seeking help, illustrating a need for evidence-based brief interventions that improve student wellness. This research study used a randomized controlled study design to examine the effects of a short-term (seven-week), solution-focused wellness intervention on perceived stress and wellness of college students. Repeated measures analysis of variance results demonstrated that the effect of group membership across time was significant for both perceived wellness and stress (p < .01). Effect sizes using partial eta2 statistics were large for both outcome variables. Findings indicate that a brief solution-focused wellness intervention can significantly improve perceptions of wellness and reduce stress among college students and is more effective than treatment as usual. Intervention replicability allows for dissemination across varied academic groups and locations, and potential generalization across populations.

Waveguide effect under 'antiguiding' conditions in graded anisotropic media.

PubMed

Kozlov, A V; Mozhaev, V G; Zyryanova, A V

2010-02-24

A new wave confinement effect is predicted in graded crystals with a concave slowness surface under conditions of growth of the phase velocity with decreasing distance from the waveguide axis. This finding overturns the common notion about the guiding and 'antiguiding' profiles of wave velocity in inhomogeneous media. The waveguide effect found is elucidated by means of ray analysis and particular exact wave solutions. The exact solution obtained for localized flexural waves in thin plates of graded cubic and tetragonal crystals confirms the predicted effect. Since this solution is substantially different with respect to the existence conditions from all others yet reported, and it cannot be deduced from the previously known results, the predicted waves can be classified as a new type of waveguide mode in graded anisotropic media. Although the concrete calculations are given in the article for acoustic waves, its general predictions are expected to be valid for waves of various natures, including spin, plasma, and optical waves.

Comparing bird and human soaring strategies

PubMed Central

Ákos, Zsuzsa; Nagy, Máté; Vicsek, Tamás

2008-01-01

Gliding saves much energy, and to make large distances using only this form of flight represents a great challenge for both birds and people. The solution is to make use of the so-called thermals, which are localized, warmer regions in the atmosphere moving upwards with a speed exceeding the descent rate of bird and plane. Whereas birds use this technique mainly for foraging, humans do it as a sporting activity. Thermalling involves efficient optimization including the skilful localization of thermals, trying to guess the most favorable route, estimating the best descending rate, etc. In this study, we address the question whether there are any analogies between the solutions birds and humans find to handle the above task. High-resolution track logs were taken from thermalling falcons and paraglider pilots to determine the essential parameters of the flight patterns. We find that there are relevant common features in the ways birds and humans use thermals. In particular, falcons seem to reproduce the MacCready formula widely used by gliders to calculate the best slope to take before an upcoming thermal. PMID:18316724

Influence of septic system wastewater treatment on titanium dioxide nanoparticle subsurface transport mechanisms.

PubMed

Waller, Travis; Marcus, Ian M; Walker, Sharon L

2018-06-04

Engineered nanomaterials (ENMs) are commonly incorporated into food and consumer applications to enhance a specific product aspect (i.e., optical properties). Life cycle analyses revealed ENMs can be released from products during usage and reach wastewater treatment plants (WWTPs), with titanium dioxide (TiO 2 ) accounting for a large fraction. As such, food grade (FG) TiO 2 , a more common form of TiO 2 in wastewater, was used in this study. Nanomaterials in WWTPs have been well characterized, although the problematic septic system has been neglected. Elution and bioaccumulation of TiO 2 ENMs from WTTPs in downriver sediments and microorganisms has been observed; however, little is known about mechanisms governing the elution of FG TiO 2 from the septic drainage system. This study characterized the transport behavior and mechanisms of FG TiO 2 particles in porous media conditions after septic waste treatment. FG and industrial grade (IG) TiO 2 (more commonly studied) were introduced to septic tank effluent and low-ionic strength electrolyte solutions prior to column transport experiments. Results indicate that FG TiO 2 aggregate size (200-400 nm) remained consistent across solutions. Additionally, elution of FG and IG TiO 2 was greatest in septic effluent at the higher nanoparticle concentration (100 ppm). FG TiO 2 was well retained at the low (2 ppm) concentration in septic effluent, suggesting that particles that escape the septic system may still be retained in drainage field before reaching the groundwater system, although eluted particles are highly stabilized. Findings provide valuable insight into the significance of the solution environment at mediating differences observed between uniquely engineered nanomaterials. Graphical abstract.

Common Workflow Service: Standards Based Solution for Managing Operational Processes

NASA Astrophysics Data System (ADS)

Tinio, A. W.; Hollins, G. A.

2017-06-01

The Common Workflow Service is a collaborative and standards-based solution for managing mission operations processes using techniques from the Business Process Management (BPM) discipline. This presentation describes the CWS and its benefits.

Cellular senescence in the Penna model of aging

NASA Astrophysics Data System (ADS)

Periwal, Avikar

2013-11-01

Cellular senescence is thought to play a major role in age-related diseases, which cause nearly 67% of all human deaths worldwide. Recent research in mice showed that exercising mice had higher levels of telomerase, an enzyme that helps maintain telomere length, than nonexercising mice. A commonly used model for biological aging was proposed by Penna. I propose a modification of the Penna model that incorporates cellular senescence and find an analytical steady-state solution following Coe, Mao, and Cates [Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.89.288103 89, 288103 (2002)]. I find that models corresponding to delayed cellular senescence have younger populations that live longer. I fit the model to the United Kingdom's death distribution, which the original Penna model cannot do.

Probing the Energy Level Alignment and the Correlation with Open-Circuit Voltage in Solution-Processed Polymeric Bulk Heterojunction Photovoltaic Devices.

PubMed

Yang, Qing-Dan; Li, Ho-Wa; Cheng, Yuanhang; Guan, Zhiqiang; Liu, Taili; Ng, Tsz-Wai; Lee, Chun-Sing; Tsang, Sai-Wing

2016-03-23

Energy level alignment at the organic donor and acceptor interface is a key to determine the photovoltaic performance in organic solar cells, but direct probing of such energy alignment is still challenging especially for solution-processed bulk heterojunction (BHJ) thin films. Here we report a systematic investigation on probing the energy level alignment with different approaches in five commonly used polymer:[6,6]-phenyl-C71-butyric acid methyl ester (PCBM) BHJ systems. We find that by tuning the weight ratio of polymer to PCBM the electronic features from both polymer and PCBM can be obtained by photoemission spectroscopy. Using this approach, we find that some of the BHJ blends simply follow vacuum level alignment, but others show strong energy level shifting as a result of Fermi level pinning. Independently, by measuring the temperature-dependent open-circuit voltage (VOC), we find that the effective energy gap (Eeff), the energy difference between the highest occupied molecular orbital of the polymer donor (EHOMO-D) and lowest unoccupied molecular orbital of the PCBM acceptor (ELUMO-A), obtained by photoemission spectroscopy in all polymer:PCBM blends has an excellent agreement with the extrapolated VOC at 0 K. Consequently, the photovoltage loss of various organic BHJ photovoltaic devices at room temperature is in a range of 0.3-0.6 V. It is believed that the demonstrated direct measurement approach of the energy level alignment in solution-processed organic BHJ will bring deeper insight into the origin of the VOC and the corresponding photovoltage loss mechanism in organic photovoltaic cells.

Coupling radiative heat transfer in participating media with other heat transfer modes

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

Tencer, John; Howell, John R.

The common methods for finding the local radiative flux divergence in participating media through solution of the radiative transfer equation are outlined. The pros and cons of each method are discussed in terms of their speed, ability to handle spectral properties and scattering phenomena, as well as their accuracy in different ranges of media transport properties. The suitability of each method for inclusion in the energy equation to efficiently solve multi-mode thermal transfer problems is discussed. Lastly, remaining topics needing research are outlined.

Coupling radiative heat transfer in participating media with other heat transfer modes

DOE PAGES

Tencer, John; Howell, John R.

2015-09-28

The common methods for finding the local radiative flux divergence in participating media through solution of the radiative transfer equation are outlined. The pros and cons of each method are discussed in terms of their speed, ability to handle spectral properties and scattering phenomena, as well as their accuracy in different ranges of media transport properties. The suitability of each method for inclusion in the energy equation to efficiently solve multi-mode thermal transfer problems is discussed. Lastly, remaining topics needing research are outlined.

The reaction of formic acid with RaneyTM copper

NASA Astrophysics Data System (ADS)

Callear, Samantha K.; Silverwood, Ian P.; Chutia, Arunabhiram; Catlow, C. Richard A.; Parker, Stewart F.

2016-04-01

The interaction of formic acid with RaneyTM Cu proves to be complex. Rather than the expected generation of a monolayer of bidentate formate, we find the formation of a Cu(II) compound. This process occurs by direct reaction of copper and formic acid; in contrast, previous methods are by solution reaction. This is a rare example of formic acid acting as an oxidant rather than, as more commonly found, a reductant. The combination of diffraction, spectroscopic and computational methods has allowed this unexpected process to be characterized.

The first international workshop on the role and impact of mathematics in medicine: A collective account

PubMed Central

Artzrouni, Marc; Begg, Colin; Chabiniok, Radomir; Clairambault, Jean; Foss, AJE; Hargrove, John; Lee, Eva K; Siggers, Jennifer H; Tindall, Marcus

2011-01-01

The First International Workshop on The Role and Impact of Mathematics in Medicine (RIMM) convened in Paris in June 2010. A broad range of researchers discussed the difficulties, challenges and opportunities faced by those wishing to see mathematical methods contribute to improved medical outcomes. Finding mechanisms for interdisciplinary meetings, developing a common language, staying focused on the medical problem at hand, deriving realistic mathematical solutions, obtaining high quality data and seeing things through “by the bedside” are some of the issues discussed by the participants.

Connecting coherent structures and strange attractors

NASA Technical Reports Server (NTRS)

Keefe, Laurence R.

1990-01-01

A concept of turbulence derived from nonlinear dynamical systems theory suggests that turbulent solutions to the Navier-Stokes equations are restricted to strange attractors, and, by implication, that turbulent phenomenology must find some expression or source in the structure of these mathematical objects. Examples and discussions are presented to link coherent structures to some of the commonly known characteristics of strange attractors. Basic to this link is a geometric interpretation of conditional sampling techniques employed to educe coherent structures that offers an explanation for their appearance in measurements as well as their size.

Qutrit witness from the Grothendieck constant of order four

NASA Astrophysics Data System (ADS)

Diviánszky, Péter; Bene, Erika; Vértesi, Tamás

2017-07-01

In this paper, we prove that KG(3 )

International Workshop on Detection, Classification and Localization of Marine Mammals Using Passive Acoustics (4th). International Workshop on Density Estimation of Marine Mammals Using Passive Acoustics (1st)

DTIC Science & Technology

2009-09-13

University of Singapore) Olivier Adam (NAMC, Univ. of Paris , France) Len Thomas (Univ St Andrews, Scotland; convenor of the DE workshop...Hervé, Paris Sébastien 90 3 - The Continuous Development for Passive Acoustic Monitoring in Offshore Commercial Industry A. Cucknell and N. Clark...encourage researchers to work on a common dataset, to focus on the same problems, to find original solutions, and to present and compare them at the

Transcellular Pathways in Lymphatic Endothelial Cells Regulate Changes in Solute Transport by Fluid Stress.

PubMed

Triacca, Valentina; Güç, Esra; Kilarski, Witold W; Pisano, Marco; Swartz, Melody A

2017-04-28

The transport of interstitial fluid and solutes into lymphatic vessels is important for maintaining interstitial homeostasis and delivering antigens and soluble factors to the lymph node for immune surveillance. Transendothelial transport across lymphatic endothelial cells (LECs) is commonly considered to occur paracellularly, or between cell-cell junctions, and driven by local pressure and concentration gradients. However, emerging evidence suggests that LECs also play active roles in regulating interstitial solute balance and can scavenge and store antigens, raising the possibility that vesicular or transcellular pathways may be important in lymphatic solute transport. The aim of this study was to determine the relative importance of transcellular (vesicular) versus paracellular transport pathways by LECs and how mechanical stress (ie, fluid flow conditioning) alters either pathway. We demonstrate that transcellular transport mechanisms substantially contribute to lymphatic solute transport and that solute uptake occurs in both caveolae- and clathrin-coated vesicles. In vivo, intracelluar uptake of fluorescently labeled albumin after intradermal injection by LECs was similar to that of dermal dendritic cells. In vitro, we developed a method to differentially quantify intracellular solute uptake versus transendothelial transport by LECs. LECs preconditioned to 1 µm/s transmural flow demonstrated increased uptake and basal-to-apical solute transport, which could be substantially reversed by blocking dynamin-dependent vesicle formation. These findings reveal the importance of intracellular transport in steady-state lymph formation and suggest that LECs use transcellular mechanisms in parallel to the well-described paracellular route to modulate solute transport from the interstitium according to biomechanical cues. © 2017 American Heart Association, Inc.

Clinical Implementation of Pharmacogenomics for Personalized Precision Medicine: Barriers and Solutions.

PubMed

Klein, Michelle E; Parvez, Md Masud; Shin, Jae-Gook

2017-09-01

Clinical implementation of pharmacogenomics (PGx) leads to personalized medicine, which improves the efficacy, safety, and cost-effectiveness of treatments. Although PGx-based research has been conducted for more than a decade, several barriers have slowed down its widespread implementation in clinical practice. Globally, there is an imbalance in programs and solutions required to empower the clinical implementation of PGx between countries. Therefore, we aimed to review these issues comprehensively, determine the major barriers, and find the best solutions. Through an extensive review of ongoing clinical implementation programs, scientific, educational, ethical, legal, and social issues, information technology, and reimbursement were identified as the key barriers. The pace of global implementation of genomic medicine coincided with the resource limitations of each country. The key solutions identified for the earlier mentioned barriers are as follows: building of secure and suitable information technology infrastructure with integrated clinical decision support systems along with increasing PGx evidence, more regulations, reimbursement strategies for stakeholder's acceptance, incorporation of PGx education in all institutions and clinics, and PGx promotion to all health care professionals and patients. In conclusion, this review will be helpful for the better understanding of common barriers and solutions pertaining to the clinical application of PGx. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

Examining the effect of initialization strategies on the performance of Gaussian mixture modeling.

PubMed

Shireman, Emilie; Steinley, Douglas; Brusco, Michael J

2017-02-01

Mixture modeling is a popular technique for identifying unobserved subpopulations (e.g., components) within a data set, with Gaussian (normal) mixture modeling being the form most widely used. Generally, the parameters of these Gaussian mixtures cannot be estimated in closed form, so estimates are typically obtained via an iterative process. The most common estimation procedure is maximum likelihood via the expectation-maximization (EM) algorithm. Like many approaches for identifying subpopulations, finite mixture modeling can suffer from locally optimal solutions, and the final parameter estimates are dependent on the initial starting values of the EM algorithm. Initial values have been shown to significantly impact the quality of the solution, and researchers have proposed several approaches for selecting the set of starting values. Five techniques for obtaining starting values that are implemented in popular software packages are compared. Their performances are assessed in terms of the following four measures: (1) the ability to find the best observed solution, (2) settling on a solution that classifies observations correctly, (3) the number of local solutions found by each technique, and (4) the speed at which the start values are obtained. On the basis of these results, a set of recommendations is provided to the user.

Isolas of periodic passive Q-switching self-pulsations in the three-level:two-level model for a laser with a saturable absorber.

PubMed

Doedel, Eusebius J; Pando, Carlos L L

2011-11-01

We show that a fundamental feature of the three-level:two-level model, used to describe molecular monomode lasers with a saturable absorber, is the existence of isolas of periodic passive Q-switching (PQS) self-pulsations. A common feature of these closed families of periodic solutions is that they contain regions of stability of the PQS self-pulsation bordered by period-doubling and fold bifurcations, when the control parameter is either the incoherent external pump or the cavity frequency detuning. These findings unveil the fundamental solution structure that is at the origin of the phenomenon known as "period-adding cascades" in our system. Using numerical continuation techniques we determine these isolas systematically, as well as the changes they undergo as secondary parameters are varied.

Gamma-irradiation of malic acid in aqueous solutions. [prebiotic significance

NASA Technical Reports Server (NTRS)

Negron-Mendoza, A.; Graff, R. L.; Ponnamperuma, C.

1980-01-01

The gamma-irradiation of malic acid in aqueous solutions was studied under initially oxygenated and oxygen-free conditions in an attempt to determine the possible interconversion of malic acid into other carboxylic acids, specifically those associated with Krebs cycle. The effect of dose on product formation of the system was investigated. Gas-liquid chromatography combined with mass spectrometry was used as the principal means of identification of the nonvolatile products. Thin layer chromatography and direct probe mass spectroscopy were also employed. The findings show that a variety of carboxylic acids are formed, with malonic and succinic acids in greatest abundance. These products have all been identified as being formed in the gamma-irradiation of acetic acid, suggesting a common intermediary. Since these molecules fit into a metabolic cycle, it is strongly suggestive that prebiotic pathways provided the basis for biological systems.

Properties of light reflected from road signs in active imaging.

PubMed

Halstuch, Aviran; Yitzhaky, Yitzhak

2008-08-01

Night vision systems in vehicles are a new emerging technology. A crucial problem in active (laser-based) systems is distortion of images by saturation and blooming due to strong retroreflections from road signs. We quantify this phenomenon. We measure the Mueller matrices and the polarization state of the reflected light from three different types of road sign commonly used. Measurements of the reflected intensity are also taken with respect to the angle of reflection. We find that different types of sign have different reflection properties. It is concluded that the optimal solution for attenuating the retroreflected intensity is using a linear polarized light source and a linear polarizer with perpendicular orientation (with regard to the source) at the detector. Unfortunately, while this solution performs well for two types of road sign, it is less efficient for the third sign type.

Inservice Teachers' Difficulties with and Resistance to Curricular Innovation: A Solution-Finding Report

ERIC Educational Resources Information Center

Center on Innovations in Learning, Temple University, 2016

2016-01-01

This Solution-Finding Report provides references and information requested on the topic of inservice teachers finding it difficult to implement, or resisting, curricular innovation. Many of the citations in this bibliography also deal with ways to overcome these difficulties and this resistance. Solution-finding Reports are intended to provide a…

Angular spectral framework to test full corrections of paraxial solutions.

PubMed

Mahillo-Isla, R; González-Morales, M J

2015-07-01

Different correction methods for paraxial solutions have been used when such solutions extend out of the paraxial regime. The authors have used correction methods guided by either their experience or some educated hypothesis pertinent to the particular problem that they were tackling. This article provides a framework so as to classify full wave correction schemes. Thus, for a given solution of the paraxial wave equation, we can select the best correction scheme of those available. Some common correction methods are considered and evaluated under the proposed scope. Another remarkable contribution is obtained by giving the necessary conditions that two solutions of the Helmholtz equation must accomplish to accept a common solution of the parabolic wave equation as a paraxial approximation of both solutions.

Surmounting the Unique Challenges in Health Disparities Education: A Multi-Institution Qualitative Study

PubMed Central

Bereknyei, Sylvia; Lie, Desiree; Braddock, Clarence H.

2010-01-01

Background The National Consortium for Multicultural Education for Health Professionals (Consortium) comprises educators representing 18 US medical schools, funded by the National Institutes of Health. Collective lessons learned from curriculum implementation by principal investigators (PIs) have the potential to guide similar educational endeavors. Objective Describe Consortium PI’s self-reported challenges with curricular development, solutions and their new curricular products. Methods Information was collected from PIs over 2 months using a 53-question structured three-part questionnaire. The questionnaire addressed PI demographics, curriculum implementation challenges and solutions, and newly created curricular products. Study participants were 18 Consortium PIs. Descriptive analysis was used for quantitative data. Narrative responses were analyzed and interpreted using qualitative thematic coding. Results Response rate was 100%. Common barriers and challenges identified by PIs were: finding administrative and leadership support, sustaining the momentum, continued funding, finding curricular space, accessing and engaging communities, and lack of education research methodology skills. Solutions identified included engaging stakeholders, project-sharing across schools, advocacy and active participation in committees and community, and seeking sustainable funding. All Consortium PIs reported new curricular products and extensive dissemination efforts outside their own institutions. Conclusion The Consortium model has added benefits for curricular innovation and dissemination for cultural competence education to address health disparities. Lessons learned may be applicable to other educational innovation efforts. PMID:20352503

Sparse approximation problem: how rapid simulated annealing succeeds and fails

NASA Astrophysics Data System (ADS)

Obuchi, Tomoyuki; Kabashima, Yoshiyuki

2016-03-01

Information processing techniques based on sparseness have been actively studied in several disciplines. Among them, a mathematical framework to approximately express a given dataset by a combination of a small number of basis vectors of an overcomplete basis is termed the sparse approximation. In this paper, we apply simulated annealing, a metaheuristic algorithm for general optimization problems, to sparse approximation in the situation where the given data have a planted sparse representation and noise is present. The result in the noiseless case shows that our simulated annealing works well in a reasonable parameter region: the planted solution is found fairly rapidly. This is true even in the case where a common relaxation of the sparse approximation problem, the G-relaxation, is ineffective. On the other hand, when the dimensionality of the data is close to the number of non-zero components, another metastable state emerges, and our algorithm fails to find the planted solution. This phenomenon is associated with a first-order phase transition. In the case of very strong noise, it is no longer meaningful to search for the planted solution. In this situation, our algorithm determines a solution with close-to-minimum distortion fairly quickly.

Barriers and Solutions to Conducting Large International, Interdisciplinary Research Projects

NASA Astrophysics Data System (ADS)

Pischke, Erin C.; Knowlton, Jessie L.; Phifer, Colin C.; Gutierrez Lopez, Jose; Propato, Tamara S.; Eastmond, Amarella; de Souza, Tatiana Martins; Kuhlberg, Mark; Picasso Risso, Valentin; Veron, Santiago R.; Garcia, Carlos; Chiappe, Marta; Halvorsen, Kathleen E.

2017-12-01

Global environmental problems such as climate change are not bounded by national borders or scientific disciplines, and therefore require international, interdisciplinary teamwork to develop understandings of their causes and solutions. Interdisciplinary scientific work is difficult enough, but these challenges are often magnified when teams also work across national boundaries. The literature on the challenges of interdisciplinary research is extensive. However, research on international, interdisciplinary teams is nearly non-existent. Our objective is to fill this gap by reporting on results from a study of a large interdisciplinary, international National Science Foundation Partnerships for International Research and Education (NSF-PIRE) research project across the Americas. We administered a structured questionnaire to team members about challenges they faced while working together across disciplines and outside of their home countries in Argentina, Brazil, and Mexico. Analysis of the responses indicated five major types of barriers to conducting interdisciplinary, international research: integration, language, fieldwork logistics, personnel and relationships, and time commitment. We discuss the causes and recommended solutions to the most common barriers. Our findings can help other interdisciplinary, international research teams anticipate challenges, and develop effective solutions to minimize the negative impacts of these barriers to their research.

Barriers and Solutions to Conducting Large International, Interdisciplinary Research Projects.

PubMed

Pischke, Erin C; Knowlton, Jessie L; Phifer, Colin C; Gutierrez Lopez, Jose; Propato, Tamara S; Eastmond, Amarella; de Souza, Tatiana Martins; Kuhlberg, Mark; Picasso Risso, Valentin; Veron, Santiago R; Garcia, Carlos; Chiappe, Marta; Halvorsen, Kathleen E

2017-12-01

Global environmental problems such as climate change are not bounded by national borders or scientific disciplines, and therefore require international, interdisciplinary teamwork to develop understandings of their causes and solutions. Interdisciplinary scientific work is difficult enough, but these challenges are often magnified when teams also work across national boundaries. The literature on the challenges of interdisciplinary research is extensive. However, research on international, interdisciplinary teams is nearly non-existent. Our objective is to fill this gap by reporting on results from a study of a large interdisciplinary, international National Science Foundation Partnerships for International Research and Education (NSF-PIRE) research project across the Americas. We administered a structured questionnaire to team members about challenges they faced while working together across disciplines and outside of their home countries in Argentina, Brazil, and Mexico. Analysis of the responses indicated five major types of barriers to conducting interdisciplinary, international research: integration, language, fieldwork logistics, personnel and relationships, and time commitment. We discuss the causes and recommended solutions to the most common barriers. Our findings can help other interdisciplinary, international research teams anticipate challenges, and develop effective solutions to minimize the negative impacts of these barriers to their research.

First principles determination of dislocation properties.

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

Hamilton, John C.

2003-12-01

This report details the work accomplished on first principles determination of dislocation properties. It contains an introduction and three chapters detailing three major accomplishments. First, we have used first principle calculations to determine the shear strength of an aluminum twin boundary. We find it to be remarkably small ({approx}17 mJ/m{sup 2}). This unexpected result is explained and will likely pertain for many other grain boundaries. Second, we have proven that the conventional explanation for finite grain boundary facets is wrong for a particular aluminum grain boundary. Instead of finite facets being stabilized by grain boundary stress, we find them tomore » originate from kinetic effects. Finally we report on a new application of the Frenkel-Kontorova model to understand reconstructions of (100) type surfaces. In addition to the commonly accepted formation of rectangular dislocation arrays, we find numerous other possible solutions to the model including hexagonal reconstructions and a clock-rotated structure.« less

Efficient heuristics for maximum common substructure search.

PubMed

Englert, Péter; Kovács, Péter

2015-05-26

Maximum common substructure search is a computationally hard optimization problem with diverse applications in the field of cheminformatics, including similarity search, lead optimization, molecule alignment, and clustering. Most of these applications have strict constraints on running time, so heuristic methods are often preferred. However, the development of an algorithm that is both fast enough and accurate enough for most practical purposes is still a challenge. Moreover, in some applications, the quality of a common substructure depends not only on its size but also on various topological features of the one-to-one atom correspondence it defines. Two state-of-the-art heuristic algorithms for finding maximum common substructures have been implemented at ChemAxon Ltd., and effective heuristics have been developed to improve both their efficiency and the relevance of the atom mappings they provide. The implementations have been thoroughly evaluated and compared with existing solutions (KCOMBU and Indigo). The heuristics have been found to greatly improve the performance and applicability of the algorithms. The purpose of this paper is to introduce the applied methods and present the experimental results.

Target immobilization as a strategy for NMR-based fragment screening: comparison of TINS, STD, and SPR for fragment hit identification.

PubMed

Kobayashi, Masakazu; Retra, Kim; Figaroa, Francis; Hollander, Johan G; Ab, Eiso; Heetebrij, Robert J; Irth, Hubertus; Siegal, Gregg

2010-09-01

Fragment-based drug discovery (FBDD) has become a widely accepted tool that is complementary to high-throughput screening (HTS) in developing small-molecule inhibitors of pharmaceutical targets. Because a fragment campaign can only be as successful as the hit matter found, it is critical that the first stage of the process be optimized. Here the authors compare the 3 most commonly used methods for hit discovery in FBDD: high concentration screening (HCS), solution ligand-observed nuclear magnetic resonance (NMR), and surface plasmon resonance (SPR). They selected the commonly used saturation transfer difference (STD) NMR spectroscopy and the proprietary target immobilized NMR screening (TINS) as representative of the array of possible NMR methods. Using a target typical of FBDD campaigns, the authors find that HCS and TINS are the most sensitive to weak interactions. They also find a good correlation between TINS and STD for tighter binding ligands, but the ability of STD to detect ligands with affinity weaker than 1 mM K(D) is limited. Similarly, they find that SPR detection is most suited to ligands that bind with K(D) better than 1 mM. However, the good correlation between SPR and potency in a bioassay makes this a good method for hit validation and characterization studies.

Perioperative intravenous fluid prescribing: a multi-centre audit.

PubMed

Harris, Benjamin; Schopflin, Christian; Khaghani, Clare; Edwards, Mark

2015-01-01

Excessive or inadequate intravenous fluid given in the perioperative period can affect outcomes. A number of guidelines exist but these can conflict with the entrenched practice, evidence base and prescriber knowledge. We conducted a multi-centre audit of intraoperative and postoperative intravenous fluid therapy to investigate fluid administration practice and frequency of postoperative electrolyte disturbances. A retrospective audit was done in five hospitals of adult patients undergoing elective major abdominal, gastrointestinal tract or orthopaedic surgery. The type, volume and quantity of fluid and electrolytes administered during surgery and in 3 days postoperatively was calculated, and electrolyte disturbances were studied using clinical records. Data from four hundred thirty-one patients in five hospitals covering 1157 intravenous fluid days were collected. Balanced crystalloid solutions were almost universally used in the operating theatre and were also the most common fluid administered postoperatively, followed by hypotonic dextrose-saline solutions and 0.9 % sodium chloride. For three common uncomplicated elective operations, the volume of fluid administered intraoperatively demonstrated considerable variability. Over half of the patients received no postoperative fluid on day 1, and even more were commenced on free oral fluids immediately postoperatively or on day 1. Postoperative quantities of sodium exceeded the recommended amounts for maintenance in half of the patients who continued to receive intravenous fluids. Potassium administration in those receiving intravenous fluids was almost universally inadequate. Hypokalaemia and hyponatraemia were the common findings. We documented the current clinical practice and confirmed that early free oral fluids and cessation of any intravenous fluids is common postoperatively in keeping with the aims of enhanced recovery after surgery programmes. Excessive sodium and water and inadequate potassium in those given intravenous fluids postoperatively is common and needs to be investigated. The variation in intraoperative fluid volume administration for three common procedures is considerable and in keeping with other international studies. Future trials of fluid therapy should include the intraoperative and postoperative phases.

Modeling Structure and Dynamics of Protein Complexes with SAXS Profiles

PubMed Central

Schneidman-Duhovny, Dina; Hammel, Michal

2018-01-01

Small-angle X-ray scattering (SAXS) is an increasingly common and useful technique for structural characterization of molecules in solution. A SAXS experiment determines the scattering intensity of a molecule as a function of spatial frequency, termed SAXS profile. SAXS profiles can be utilized in a variety of molecular modeling applications, such as comparing solution and crystal structures, structural characterization of flexible proteins, assembly of multi-protein complexes, and modeling of missing regions in the high-resolution structure. Here, we describe protocols for modeling atomic structures based on SAXS profiles. The first protocol is for comparing solution and crystal structures including modeling of missing regions and determination of the oligomeric state. The second protocol performs multi-state modeling by finding a set of conformations and their weights that fit the SAXS profile starting from a single-input structure. The third protocol is for protein-protein docking based on the SAXS profile of the complex. We describe the underlying software, followed by demonstrating their application on interleukin 33 (IL33) with its primary receptor ST2 and DNA ligase IV-XRCC4 complex. PMID:29605933

Control of size and aspect ratio in hydroquinone-based synthesis of gold nanorods

NASA Astrophysics Data System (ADS)

Morasso, Carlo; Picciolini, Silvia; Schiumarini, Domitilla; Mehn, Dora; Ojea-Jiménez, Isaac; Zanchetta, Giuliano; Vanna, Renzo; Bedoni, Marzia; Prosperi, Davide; Gramatica, Furio

2015-08-01

In this article, we describe how it is possible to tune the size and the aspect ratio of gold nanorods obtained using a highly efficient protocol based on the use of hydroquinone as a reducing agent by varying the amounts of CTAB and silver ions present in the "seed-growth" solution. Our approach not only allows us to prepare nanorods with a four times increased Au3+ reduction yield, when compared with the commonly used protocol based on ascorbic acid, but also allows a remarkable reduction of 50-60 % of the amount of CTAB needed. In fact, according to our findings, the concentration of CTAB present in the seed-growth solution do not linearly influence the final aspect ratio of the obtained nanorods, and an optimal concentration range between 30 and 50 mM has been identified as the one that is able to generate particles with more elongated shapes. On the optimized protocol, the effect of the concentration of Ag+ ions in the seed-growth solution and the stability of the obtained particles has also been investigated.

Proper use of medical language: Main problems and solutions.

PubMed

Aleixandre-Benavent, R; Valderrama Zurián, J C; Bueno-Cañigral, F J

2015-10-01

Medical language should be characterized by its precision, emotional neutrality and stability. The effective communication of results of scientific studies depends on compliance with current standards of drafting and style; texts with defects can hinder interest in the findings. In this study, we discuss some of the most common problems and errors in medical language, including the abuse of abbreviations and foreign words, the use of improper words, syntax errors and solecisms, the most common errors in titles and the abuse of capital letters and the gerund. Investigators have effective tools for dealing with these problems, such as quality texts, critical dictionaries of questions and difficulties with the Spanish language and various drafting and style manuals. Copyright © 2015 Elsevier España, S.L.U. y Sociedad Española de Medicina Interna (SEMI). All rights reserved.

Finding the probability of infection in an SIR network is NP-Hard

PubMed Central

Shapiro, Michael; Delgado-Eckert, Edgar

2012-01-01

It is the purpose of this article to review results that have long been known to communications network engineers and have direct application to epidemiology on networks. A common approach in epidemiology is to study the transmission of a disease in a population where each individual is initially susceptible (S), may become infective (I) and then removed or recovered (R) and plays no further epidemiological role. Much of the recent work gives explicit consideration to the network of social interactions or disease-transmitting contacts and attendant probability of transmission for each interacting pair. The state of such a network is an assignment of the values {S, I, R} to its members. Given such a network, an initial state and a particular susceptible individual, we would like to compute their probability of becoming infected in the course of an epidemic. It turns out that this and related problems are NP-hard. In particular, it belongs in a class of problems for which no efficient algorithms for their solution are known. Moreover, finding an efficient algorithm for the solution of any problem in this class would entail a major breakthrough in theoretical computer science. PMID:22824138

The existence of a temperature-driven solid solution in LixFePO4 for 0 <= x <= 1

NASA Astrophysics Data System (ADS)

Delacourt, Charles; Poizot, Philippe; Tarascon, Jean-Marie; Masquelier, Christian

2005-03-01

Lithium-ion batteries have revolutionized the powering of portable electronics. Electrode reactions in these electrochemical systems are based on reversible insertion/deinsertion of Li+ ions into the host electrode material with a concomitant addition/removal of electrons into the host. If such batteries are to find a wider market such as the automotive industry, less expensive positive electrode materials will be required, among which LiFePO4 is a leading contender. An intriguing fundamental problem is to understand the fast electrochemical response from the poorly electronic conducting two-phase LiFePO4/FePO4 system. In contrast to the well-documented two-phase nature of this system at room temperature, we give the first experimental evidence of a solid solution LixFePO4 (0 <= x <= 1) at 450 °C, and two new metastable phases at room temperature with Li0.75FePO4 and Li0.5FePO4 composition. These experimental findings challenge theorists to improve predictive models commonly used in the field. Our results may also lead to improved performances of these electrodes at elevated temperatures.

The Apollo Expericence Lessons Learned for Constellation Lunar Dust Management

NASA Astrophysics Data System (ADS)

Wagner, Sandra

2006-09-01

Lunar dust will present significant challenges to NASA's Lunar Exploration Missions. The challenges can be overcome by using best practices in system engineering design. For successful lunar surface missions, all systems that come into contact with lunar dust must consider the effects throughout the entire design process. Interfaces between all these systems with other systems also must be considered. Incorporating dust management into Concept of Operations and Requirements development are the best place to begin to mitigate the risks presented by lunar dust. However, that is only the beginning. To be successful, every person who works on NASA's Constellation lunar missions must be mindful of this problem. Success will also require fiscal responsibility. NASA must learn from Apollo the root cause of problems caused by dust, and then find the most cost-effective solutions to address each challenge. This will require a combination of common sense existing technologies and promising, innovative technical solutions

A generalized method for determining radiation patterns of aperture antennas and its application to reflector antennas. M.S. Thesis

NASA Technical Reports Server (NTRS)

Paknys, J. R.

1982-01-01

The reflector antenna may be thought of as an aperture antenna. The classical solution for the radiation pattern of such an antenna is found by the aperture integration (AI) method. Success with this method depends on how accurately the aperture currents are known beforehand. In the past, geometrical optics (GO) has been employed to find the aperture currents. This approximation is suitable for calculating the main beam and possibly the first few sidelobes. A better approximation is to use aperture currents calculated from the geometrical theory of diffraction (GTD). Integration of the GTD currents over and extended aperture yields more accurate results for the radiation pattern. This approach is useful when conventional AI and GTD solutions have no common region of validity. This problem arises in reflector antennas. Two dimensional models of parabolic reflectors are studied; however, the techniques discussed can be applied to any aperture antenna.

Number Theoretic Background

NASA Astrophysics Data System (ADS)

Rudnick, Z.

Contents: 1. Introduction 2. Divisibility 2.1. Basics on Divisibility 2.2. The Greatest Common Divisor 2.3. The Euclidean Algorithm 2.4. The Diophantine Equation ax+by=c 3. Prime Numbers 3.1. The Fundamental Theorem of Arithmetic 3.2. There Are Infinitely Many Primes 3.3. The Density of Primes 3.4. Primes in Arithmetic Progressions 4. Continued Fractions 5. Modular Arithmetic 5.1. Congruences 5.2. Modular Inverses 5.3. The Chinese Remainder Theorem 5.4. The Structure of the Multiplicative Group (Z/NZ)^* 5.5. Primitive Roots 6. Quadratic Congruences 6.1. Euler's Criterion 6.2. The Legendre Symbol and Quadratic Reciprocity 7. Pell's Equation 7.1. The Group Law 7.2. Integer Solutions 7.3. Finding the Fundamental Solution 8. The Riemann Zeta Function 8.1 Analytic Continuation and Functinal Equation of ζ(s) 8.2 Connecting the Primes and the Zeros of ζ(s) 8.3 The Riemann Hypothesis References

Model of two-temperature convective transfer in porous media

NASA Astrophysics Data System (ADS)

Gruais, Isabelle; Poliševski, Dan

2017-12-01

In this paper, we study the asymptotic behaviour of the solution of a convective heat transfer boundary problem in an ɛ -periodic domain which consists of two interwoven phases, solid and fluid, separated by an interface. The fluid flow and its dependence with respect to the temperature are governed by the Boussinesq approximation of the Stokes equations. The tensors of thermal diffusion of both phases are ɛ -periodic, as well as the heat transfer coefficient which is used to describe the first-order jump condition on the interface. We find by homogenization that the two-scale limits of the solutions verify the most common system used to describe local thermal non-equilibrium phenomena in porous media (see Nield and Bejan in Convection in porous media, Springer, New York, 1999; Rees and Pop in Transport phenomena in porous media III, Elsevier, Oxford, 2005). Since now, this system was justified only by volume averaging arguments.

The Apollo Experience Lessons Learned for Constellation Lunar Dust Management

NASA Technical Reports Server (NTRS)

Wagner, Sandra

2006-01-01

Lunar dust will present significant challenges to NASA's Lunar Exploration Missions. The challenges can be overcome by using best practices in system engineering design. For successful lunar surface missions, all systems that come into contact with lunar dust must consider the effects throughout the entire design process. Interfaces between all these systems with other systems also must be considered. Incorporating dust management into Concept of Operations and Requirements development are the best place to begin to mitigate the risks presented by lunar dust. However, that is only the beginning. To be successful, every person who works on NASA's Constellation lunar missions must be mindful of this problem. Success will also require fiscal responsibility. NASA must learn from Apollo the root cause of problems caused by dust, and then find the most cost-effective solutions to address each challenge. This will require a combination of common sense existing technologies and promising, innovative technical solutions

Mechanical properties on geopolymer brick: A review

NASA Astrophysics Data System (ADS)

Deraman, L. M.; Abdullah, M. M. A.; Ming, L. Y.; Ibrahim, W. M. W.; Tahir, M. F. M.

2017-09-01

Bricks has stand for many years as durable construction substantial, especially in the area of civil engineering to construct buildings. Brick commonly used in the structure of buildings as a construction wall, cladding, facing perimeter, paving, garden wall and flooring. The contribution of ordinary Portland cement (OPC) in cement bricks production worldwide to greenhouse gas emissions. Due to this issue, some researchers have done their study with other materials to produce bricks, especially as a by-product material. Researchers take effort in this regard to synthesizing from by-product materials such as fly ash, bottom ash and kaolin that are rich in silicon and aluminium in the development of inorganic alumina-silicate polymer, called geopolymer Geopolymer is a polymerization reaction between various aluminosilicate oxides with silicates solution or alkali hydroxide solution forming polymerized Si-O-Al-O bonds. This paper summarized some research finding of mechanical properties of geopolymer brick using by-product materials.

Study of coupled nonlinear partial differential equations for finding exact analytical solutions.

PubMed

Khan, Kamruzzaman; Akbar, M Ali; Koppelaar, H

2015-07-01

Exact solutions of nonlinear partial differential equations (NPDEs) are obtained via the enhanced (G'/G)-expansion method. The method is subsequently applied to find exact solutions of the Drinfel'd-Sokolov-Wilson (DSW) equation and the (2+1)-dimensional Painlevé integrable Burgers (PIB) equation. The efficiency of this method for finding these exact solutions is demonstrated. The method is effective and applicable for many other NPDEs in mathematical physics.

Copper Sensing in Alkaline Electrolyte Using Anodic Stripping Voltammetry by Means of a Lead Mediator

DOE PAGES

Duay, Jonathon; Ortiz-Santiago, Joed E.; Lambert, Timothy N.

2017-10-05

Anodic stripping voltammetry (ASV) is an analysis technique that permits the selective and quantitative analysis of metal ion species in solution. It is most commonly applied in neutral to acidic electrolyte largely due to inherent metal ion solubility. Bismuth (Bi) is a common film used for ASV due to its good sensitivity, overall stability and insensitivity to O2. ASV, utilizing a Bi film, along with cadmium (Cd) and lead (Pb) as the plating mediators, has recently been adapted to determine zinc (Zn) concentrations in highly alkaline environments (30 % NaOH or 35 % M KOH). Successful analysis of Zn inmore » alkaline relies on the ability of the hydroxide to form soluble metal anion species, such as Bi(OH) 4 – and Zn(OH) 4 2–. Here, we look to extend this technique to detect and quantify copper (Cu) ions in these highly basic electrolytes. However, in general, the use of ASV to detect and quantify Cu ion concentrations is notoriously difficult as the Cu stripping peak potential overlays with that of Bi from the common Bi film electrode. Here, an ASV method for determining Cu concentration in alkaline solutions is developed utilizing Pb as a deposition mediator. As such, it was found that when analyzing Cu solutions in the presence of Pb, the stripping voltammetry curves present separate and defined Cu stripping peaks. Different analyzes were made to find the best stripping voltammetry performance conditions. As such, an accumulation time of 5 minutes, an accumulation potential of ≤–1.45 V vs. Hg/HgO, and a concentration of 35 wt% KOH were determined to be the conditions that presented the best ASV results. Utilizing these conditions, calibration curves in the presence of 5.0 ppm Pb showed the best linear stripping signal correlation with an r-squared value of 0.991 and a limit of detection (LOD) of 0.67 ppm. Lastly, these results give way to evaluating Cu concentrations using ASV in aqueous alkaline solutions.« less

Copper Sensing in Alkaline Electrolyte Using Anodic Stripping Voltammetry by Means of a Lead Mediator

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

Duay, Jonathon; Ortiz-Santiago, Joed E.; Lambert, Timothy N.

Anodic stripping voltammetry (ASV) is an analysis technique that permits the selective and quantitative analysis of metal ion species in solution. It is most commonly applied in neutral to acidic electrolyte largely due to inherent metal ion solubility. Bismuth (Bi) is a common film used for ASV due to its good sensitivity, overall stability and insensitivity to O2. ASV, utilizing a Bi film, along with cadmium (Cd) and lead (Pb) as the plating mediators, has recently been adapted to determine zinc (Zn) concentrations in highly alkaline environments (30 % NaOH or 35 % M KOH). Successful analysis of Zn inmore » alkaline relies on the ability of the hydroxide to form soluble metal anion species, such as Bi(OH) 4 – and Zn(OH) 4 2–. Here, we look to extend this technique to detect and quantify copper (Cu) ions in these highly basic electrolytes. However, in general, the use of ASV to detect and quantify Cu ion concentrations is notoriously difficult as the Cu stripping peak potential overlays with that of Bi from the common Bi film electrode. Here, an ASV method for determining Cu concentration in alkaline solutions is developed utilizing Pb as a deposition mediator. As such, it was found that when analyzing Cu solutions in the presence of Pb, the stripping voltammetry curves present separate and defined Cu stripping peaks. Different analyzes were made to find the best stripping voltammetry performance conditions. As such, an accumulation time of 5 minutes, an accumulation potential of ≤–1.45 V vs. Hg/HgO, and a concentration of 35 wt% KOH were determined to be the conditions that presented the best ASV results. Utilizing these conditions, calibration curves in the presence of 5.0 ppm Pb showed the best linear stripping signal correlation with an r-squared value of 0.991 and a limit of detection (LOD) of 0.67 ppm. Lastly, these results give way to evaluating Cu concentrations using ASV in aqueous alkaline solutions.« less

Data Management challenges in Astronomy and Astroparticle Physics

NASA Astrophysics Data System (ADS)

Lamanna, Giovanni

2015-12-01

Astronomy and Astroparticle Physics domains are experiencing a deluge of data with the next generation of facilities prioritised in the European Strategy Forum on Research Infrastructures (ESFRI), such as SKA, CTA, KM3Net and with other world-class projects, namely LSST, EUCLID, EGO, etc. The new ASTERICS-H2020 project brings together the concerned scientific communities in Europe to work together to find common solutions to their Big Data challenges, their interoperability, and their data access. The presentation will highlight these new challenges and the work being undertaken also in cooperation with e-infrastructures in Europe.

Inhomogeneity-induced cosmic acceleration in a dust universe

NASA Astrophysics Data System (ADS)

Chuang, Chia-Hsun; Gu, Je-An; Hwang, W.-Y. P.

2008-09-01

It is the common consensus that the expansion of a universe always slows down if the gravity provided by the energy sources therein is attractive and accordingly one needs to invoke dark energy as a source of anti-gravity for understanding the cosmic acceleration. To examine this point we find counterexamples for a spherically symmetric dust fluid described by the Lemaître Tolman Bondi solution without singularity. Thus, the validity of this naive consensus is indeed doubtful and the effects of inhomogeneities should be restudied. These counter-intuitive examples open a new perspective on the understanding of the evolution of our universe.

Model for the computation of self-motion in biological systems

NASA Technical Reports Server (NTRS)

Perrone, John A.

1992-01-01

A technique is presented by which direction- and speed-tuned cells, such as those commonly found in the middle temporal region of the primate brain, can be utilized to analyze the patterns of retinal image motion that are generated during observer movement through the environment. The developed model determines heading by finding the peak response in a population of detectors or neurons each tuned to a particular heading direction. It is suggested that a complex interaction of multiple cell networks is required for the solution of the self-motion problem in the primate brain.

Meniscal Preservation is Important for the Knee Joint

PubMed Central

Patil, Shantanu Sudhakar; Shekhar, Anshu; Tapasvi, Sachin Ramchandra

2017-01-01

Native joint preservation has gained importance in recent years. This is mostly to find solutions for limitations of arthroplasty. In the knee joint, the menisci perform critical functions, adding stability during range of motion and efficiently transferring load across the tibiofemoral articulation while protecting the cartilage. The menisci are the most common injury seen by orthopedicians, especially in the younger active patients. Advances in technology and our knowledge on functioning of the knee joint have made meniscus repair an important mode of treatment. This review summarizes the various techniques of meniscus tear repair and also describes biological enhancements of healing. PMID:28966381

Performance comparison of genetic algorithms and particle swarm optimization for model integer programming bus timetabling problem

NASA Astrophysics Data System (ADS)

Wihartiko, F. D.; Wijayanti, H.; Virgantari, F.

2018-03-01

Genetic Algorithm (GA) is a common algorithm used to solve optimization problems with artificial intelligence approach. Similarly, the Particle Swarm Optimization (PSO) algorithm. Both algorithms have different advantages and disadvantages when applied to the case of optimization of the Model Integer Programming for Bus Timetabling Problem (MIPBTP), where in the case of MIPBTP will be found the optimal number of trips confronted with various constraints. The comparison results show that the PSO algorithm is superior in terms of complexity, accuracy, iteration and program simplicity in finding the optimal solution.

Common quandaries and their practical solutions in Bayesian network modeling

Treesearch

Bruce G. Marcot

2017-01-01

Use and popularity of Bayesian network (BN) modeling has greatly expanded in recent years, but many common problems remain. Here, I summarize key problems in BN model construction and interpretation,along with suggested practical solutions. Problems in BN model construction include parameterizing probability values, variable definition, complex network structures,...

Practical Tools for Foster Parents. Foster Care Solutions.

ERIC Educational Resources Information Center

Temple-Plotz, Lana, Ed.; Stricklett, Ted P., Ed.; Baker, Christena B., Ed.; Sterba, Michael N., Ed.

Based on the Girls and Boys Town's "Common Sense Parenting" approach, this book presents an approach to foster parenting focusing on building relationships with children, teaching them skills, and empowering them by teaching self-discipline and self-control. Research-based solutions are provided for common concerns, including building a…

Efficient selection of tagging single-nucleotide polymorphisms in multiple populations.

PubMed

Howie, Bryan N; Carlson, Christopher S; Rieder, Mark J; Nickerson, Deborah A

2006-08-01

Common genetic polymorphism may explain a portion of the heritable risk for common diseases, so considerable effort has been devoted to finding and typing common single-nucleotide polymorphisms (SNPs) in the human genome. Many SNPs show correlated genotypes, or linkage disequilibrium (LD), suggesting that only a subset of all SNPs (known as tagging SNPs, or tagSNPs) need to be genotyped for disease association studies. Based on the genetic differences that exist among human populations, most tagSNP sets are defined in a single population and applied only in populations that are closely related. To improve the efficiency of multi-population analyses, we have developed an algorithm called MultiPop-TagSelect that finds a near-minimal union of population-specific tagSNP sets across an arbitrary number of populations. We present this approach as an extension of LD-select, a tagSNP selection method that uses a greedy algorithm to group SNPs into bins based on their pairwise association patterns, although the MultiPop-TagSelect algorithm could be used with any SNP tagging approach that allows choices between nearly equivalent SNPs. We evaluate the algorithm by considering tagSNP selection in candidate-gene resequencing data and lower density whole-chromosome data. Our analysis reveals that an exhaustive search is often intractable, while the developed algorithm can quickly and reliably find near-optimal solutions even for difficult tagSNP selection problems. Using populations of African, Asian, and European ancestry, we also show that an optimal multi-population set of tagSNPs can be substantially smaller (up to 44%) than a typical set obtained through independent or sequential selection.

Energy, momentum and propagation of non-paraxial high-order Gaussian beams in the presence of an aperture

NASA Astrophysics Data System (ADS)

Stilgoe, Alexander B.; Nieminen, Timo A.; Rubinsztein-Dunlop, Halina

2015-12-01

Non-paraxial theories of wave propagation are essential to model the interaction of highly focused light with matter. Here we investigate the energy, momentum and propagation of the Laguerre-, Hermite- and Ince-Gaussian solutions (LG, HG, and IG) of the paraxial wave equation in an apertured non-paraxial regime. We investigate the far-field relationships between the LG, HG, and IG solutions and the vector spherical wave function (VSWF) solutions of the vector Helmholtz wave equation. We investigate the convergence of the VSWF and the various Gaussian solutions in the presence of an aperture. Finally, we investigate the differences in linear and angular momentum evaluated in the paraxial and non-paraxial regimes. The non-paraxial model we develop can be applied to calculations of the focusing of high-order Gaussian modes in high-resolution microscopes. We find that the addition of an aperture in high numerical aperture optical systems does not greatly affect far-field properties except when the beam is significantly clipped by an aperture. Diffraction from apertures causes large distortions in the near-field and will influence light-matter interactions. The method is not limited to a particular solution of the paraxial wave equation. Our model is constructed in a formalism that is commonly used in scattering calculations. It is thus applicable to optical trapping and other optical investigations of matter.

Study of coupled nonlinear partial differential equations for finding exact analytical solutions

PubMed Central

Khan, Kamruzzaman; Akbar, M. Ali; Koppelaar, H.

2015-01-01

Exact solutions of nonlinear partial differential equations (NPDEs) are obtained via the enhanced (G′/G)-expansion method. The method is subsequently applied to find exact solutions of the Drinfel'd–Sokolov–Wilson (DSW) equation and the (2+1)-dimensional Painlevé integrable Burgers (PIB) equation. The efficiency of this method for finding these exact solutions is demonstrated. The method is effective and applicable for many other NPDEs in mathematical physics. PMID:26587256

Exploring public perceptions of solutions to tree diseases in the UK: Implications for policy-makers.

PubMed

Jepson, Paul; Arakelyan, Irina

2017-10-01

Tree diseases are on the increase in many countries and the implications of their appearance can be political, as well as ecological and economic. Preventative policy approaches to tree diseases are difficult to formulate because dispersal pathways for pest and pathogens are numerous, poorly known and likely to be beyond human management control. Genomic techniques could offer the quickest and most predictable approach to developing a disease tolerant native ash. The population of European Ash ( Fraxinus Excelsi or) has suffered major losses in the last decade, due to the onset of Hymenoscyphus fraxineus (previously called Chalara Fraxinea ) commonly known in the UK as ash dieback. This study presents evidence on the public acceptability of tree-breed solutions to the spread of Chalara , with the main aim to provide science and policy with an up-stream 'steer' on the likely public acceptability of different tree breeding solutions. The findings showed that whilst there was a firm anti-GM and ' we shouldn't tamper with nature ' attitude among UK publics, there was an equally firm and perhaps slightly larger pragmatic attitude that GM (science and technology) should be used if there is a good reason to do so, for example if it can help protect trees from disease and help feed the world. The latter view was significantly stronger among younger age groups (Millennials), those living in urban areas and when the (GM)modified trees were destined for urban and plantation, rather than countryside settings. Overall, our findings suggest that the UK government could consider genomic solutions to tree breeding with more confidence in the future, as large and influential publics appear to be relaxed about the use of genomic techniques to increase tolerance of trees to disease.

On gamesmen and fair men: explaining fairness in non-cooperative bargaining games.

PubMed

Suleiman, Ramzi

2018-02-01

Experiments on bargaining games have repeatedly shown that subjects fail to use backward induction, and that they only rarely make demands in accordance with the subgame perfect equilibrium. In a recent paper, we proposed an alternative model, termed 'economic harmony' in which we modified the individual's utility by defining it as a function of the ratio between the actual and aspired pay-offs. We also abandoned the notion of equilibrium, in favour of a new notion of 'harmony', defined as the intersection of strategies, at which all players are equally satisfied. We showed that the proposed model yields excellent predictions of offers in the ultimatum game, and requests in the sequential common pool resource dilemma game. Strikingly, the predicted demand in the ultimatum game is equal to the famous Golden Ratio (approx. 0.62 of the entire pie). The same prediction was recently derived independently by Schuster (Schuster 2017. Sci. Rep. 7 , 5642). In this paper, we extend the solution to bargaining games with alternating offers. We show that the derived solution predicts the opening demands reported in several experiments, on games with equal and unequal discount factors and game horizons. Our solution also predicts several unexplained findings, including the puzzling 'disadvantageous counter-offers', and the insensitivity of opening demands to variations in the players' discount factors, and game horizon. Strikingly, we find that the predicted opening demand in the alternating offers game is also equal to the Golden Ratio.

On gamesmen and fair men: explaining fairness in non-cooperative bargaining games

PubMed Central

2018-01-01

Experiments on bargaining games have repeatedly shown that subjects fail to use backward induction, and that they only rarely make demands in accordance with the subgame perfect equilibrium. In a recent paper, we proposed an alternative model, termed ‘economic harmony’ in which we modified the individual's utility by defining it as a function of the ratio between the actual and aspired pay-offs. We also abandoned the notion of equilibrium, in favour of a new notion of ‘harmony’, defined as the intersection of strategies, at which all players are equally satisfied. We showed that the proposed model yields excellent predictions of offers in the ultimatum game, and requests in the sequential common pool resource dilemma game. Strikingly, the predicted demand in the ultimatum game is equal to the famous Golden Ratio (approx. 0.62 of the entire pie). The same prediction was recently derived independently by Schuster (Schuster 2017. Sci. Rep. 7, 5642). In this paper, we extend the solution to bargaining games with alternating offers. We show that the derived solution predicts the opening demands reported in several experiments, on games with equal and unequal discount factors and game horizons. Our solution also predicts several unexplained findings, including the puzzling ‘disadvantageous counter-offers’, and the insensitivity of opening demands to variations in the players' discount factors, and game horizon. Strikingly, we find that the predicted opening demand in the alternating offers game is also equal to the Golden Ratio. PMID:29515877

Evaluation of a Public Awareness Campaign to Prevent High School Dropout.

PubMed

Babinski, Leslie M; Corra, Ashley J; Gifford, Elizabeth J

2016-08-01

Many advocacy organizations devote time and resources to increasing community awareness and educating the public in an effort to gain support for their issue. One such effort, the Dropout Prevention Campaign by America's Promise Alliance, aimed to increase the visibility of the high school dropout problem and mobilize the community to take action. The objective of this paper is to evaluate the framing of the Dropout Prevention Campaign in television news media. To evaluate this campaign, television news coverage about high school dropout in 12 U.S. communities (N = 982) was examined. A content analysis of news transcripts was conducted and coded to determine the definition of the problem, the reasons for dropout and the possible solutions. Findings indicated that the high school dropout problem was most often framed (30 % of news segments) in terms of the economic and societal implications for the community. Individual student factors as well as broader societal influences were frequently discussed as possible reasons for dropout. The most commonly mentioned solutions were school-based interventions. News segments that mentioned America's Promise Alliance were more likely to frame the issue as a crisis and to use statistics to illustrate that point. Solutions that were more likely to appear in America's Promise segments promoted community and cross-sector involvement, consistent with the messages promoted by the Dropout Prevention Campaign. The findings suggest that a media content analysis can be an effective framework for analyzing a prevention campaign.

Breast imaging in patients with nipple discharge

PubMed Central

de Paula, Ivie Braga; Campos, Adriene Moraes

2017-01-01

Nipple discharge is a common symptom in clinical practice, representing the third leading breast complaint, after pain and lumps. It is usually limited and has a benign etiology. The risk of malignancy is higher when the discharge is uniductal, unilateral, spontaneous, persistent, bloody, or serous, as well as when it is accompanied by a breast mass. The most common causes of pathologic nipple discharge are papilloma and ductal ectasia. However, there is a 5% risk of malignancy, mainly ductal carcinoma in situ. The clinical examination is an essential part of the patient evaluation, allowing benign nipple discharge to be distinguished from suspicious nipple discharge, which calls for imaging. Mammography and ultrasound should be used together as first-line imaging methods. However, mammography has low sensitivity in cases of nipple discharge, because, typically, the lesions are small, are retroareolar, and contain no calcifications. Because the reported sensitivity and specificity of ultrasound, it is important to use the correct technique to search for intraductal lesions in the retroareolar region. Recent studies recommend the use of magnetic resonance imaging in cases of suspicious nipple discharge in which the mammography and ultrasound findings are normal. The most common magnetic resonance imaging finding is non-mass enhancement. Surgery is no longer the only solution for patients with suspicious nipple discharge, because short-time follow-up can be safely proposed. PMID:29307929

Subharmonic Solutions of Order One-Third

ERIC Educational Resources Information Center

Fay, Temple H.

2005-01-01

Finding a periodic solution to a nonlinear ordinary differential equation is in general a difficult task. Only in a very few cases can direct methods be applied to an equation to find initial values leading to a solution of the corresponding initial value problem that is periodic. Oscillatory periodic solutions have such practical importance that…

Development and acceleration of unstructured mesh-based cfd solver

NASA Astrophysics Data System (ADS)

Emelyanov, V.; Karpenko, A.; Volkov, K.

2017-06-01

The study was undertaken as part of a larger effort to establish a common computational fluid dynamics (CFD) code for simulation of internal and external flows and involves some basic validation studies. The governing equations are solved with ¦nite volume code on unstructured meshes. The computational procedure involves reconstruction of the solution in each control volume and extrapolation of the unknowns to find the flow variables on the faces of control volume, solution of Riemann problem for each face of the control volume, and evolution of the time step. The nonlinear CFD solver works in an explicit time-marching fashion, based on a three-step Runge-Kutta stepping procedure. Convergence to a steady state is accelerated by the use of geometric technique and by the application of Jacobi preconditioning for high-speed flows, with a separate low Mach number preconditioning method for use with low-speed flows. The CFD code is implemented on graphics processing units (GPUs). Speedup of solution on GPUs with respect to solution on central processing units (CPU) is compared with the use of different meshes and different methods of distribution of input data into blocks. The results obtained provide promising perspective for designing a GPU-based software framework for applications in CFD.

Recursively constructing analytic expressions for equilibrium distributions of stochastic biochemical reaction networks.

PubMed

Meng, X Flora; Baetica, Ania-Ariadna; Singhal, Vipul; Murray, Richard M

2017-05-01

Noise is often indispensable to key cellular activities, such as gene expression, necessitating the use of stochastic models to capture its dynamics. The chemical master equation (CME) is a commonly used stochastic model of Kolmogorov forward equations that describe how the probability distribution of a chemically reacting system varies with time. Finding analytic solutions to the CME can have benefits, such as expediting simulations of multiscale biochemical reaction networks and aiding the design of distributional responses. However, analytic solutions are rarely known. A recent method of computing analytic stationary solutions relies on gluing simple state spaces together recursively at one or two states. We explore the capabilities of this method and introduce algorithms to derive analytic stationary solutions to the CME. We first formally characterize state spaces that can be constructed by performing single-state gluing of paths, cycles or both sequentially. We then study stochastic biochemical reaction networks that consist of reversible, elementary reactions with two-dimensional state spaces. We also discuss extending the method to infinite state spaces and designing the stationary behaviour of stochastic biochemical reaction networks. Finally, we illustrate the aforementioned ideas using examples that include two interconnected transcriptional components and biochemical reactions with two-dimensional state spaces. © 2017 The Author(s).

Recursively constructing analytic expressions for equilibrium distributions of stochastic biochemical reaction networks

PubMed Central

Baetica, Ania-Ariadna; Singhal, Vipul; Murray, Richard M.

2017-01-01

Noise is often indispensable to key cellular activities, such as gene expression, necessitating the use of stochastic models to capture its dynamics. The chemical master equation (CME) is a commonly used stochastic model of Kolmogorov forward equations that describe how the probability distribution of a chemically reacting system varies with time. Finding analytic solutions to the CME can have benefits, such as expediting simulations of multiscale biochemical reaction networks and aiding the design of distributional responses. However, analytic solutions are rarely known. A recent method of computing analytic stationary solutions relies on gluing simple state spaces together recursively at one or two states. We explore the capabilities of this method and introduce algorithms to derive analytic stationary solutions to the CME. We first formally characterize state spaces that can be constructed by performing single-state gluing of paths, cycles or both sequentially. We then study stochastic biochemical reaction networks that consist of reversible, elementary reactions with two-dimensional state spaces. We also discuss extending the method to infinite state spaces and designing the stationary behaviour of stochastic biochemical reaction networks. Finally, we illustrate the aforementioned ideas using examples that include two interconnected transcriptional components and biochemical reactions with two-dimensional state spaces. PMID:28566513

A Bayesian approach to the creation of a study-customized neonatal brain atlas

PubMed Central

Zhang, Yajing; Chang, Linda; Ceritoglu, Can; Skranes, Jon; Ernst, Thomas; Mori, Susumu; Miller, Michael I.; Oishi, Kenichi

2014-01-01

Atlas-based image analysis (ABA), in which an anatomical “parcellation map” is used for parcel-by-parcel image quantification, is widely used to analyze anatomical and functional changes related to brain development, aging, and various diseases. The parcellation maps are often created based on common MRI templates, which allow users to transform the template to target images, or vice versa, to perform parcel-by-parcel statistics, and report the scientific findings based on common anatomical parcels. The use of a study-specific template, which represents the anatomical features of the study population better than common templates, is preferable for accurate anatomical labeling; however, the creation of a parcellation map for a study-specific template is extremely labor intensive, and the definitions of anatomical boundaries are not necessarily compatible with those of the common template. In this study, we employed a Volume-based Template Estimation (VTE) method to create a neonatal brain template customized to a study population, while keeping the anatomical parcellation identical to that of a common MRI atlas. The VTE was used to morph the standardized parcellation map of the JHU-neonate-SS atlas to capture the anatomical features of a study population. The resultant “study-customized” T1-weighted and diffusion tensor imaging (DTI) template, with three-dimensional anatomical parcellation that defined 122 brain regions, was compared with the JHU-neonate-SS atlas, in terms of the registration accuracy. A pronounced increase in the accuracy of cortical parcellation and superior tensor alignment were observed when the customized template was used. With the customized atlas-based analysis, the fractional anisotropy (FA) detected closely approximated the manual measurements. This tool provides a solution for achieving normalization-based measurements with increased accuracy, while reporting scientific findings in a consistent framework. PMID:25026155

BeiDou Time Transfer With the Standard CGGTTS.

PubMed

Huang, Wei; Defraigne, Pascale

2016-07-01

The R2CGGTTS software tool developed at the Royal Observatory of Belgium (ROB) to provide clock solutions in the standard Common GNSS Generic Time Transfer Standard (CGGTTS) has been extended to BeiDou Navigation Satellite System (BDS). The BDS includes satellites in three different orbits: 1) Medium Earth Orbit (MEO); 2) Inclined Geosynchronous Satellite Orbit (IGSO); and 3) Geostationary Earth Orbit (GEO). This paper presents first results obtained with this upgraded software, and a comparison between common view (CV) time transfer solutions obtained with either BDS, or GPS or Galileo. These preliminary results indicate that the BeiDou MEO satellites give time transfer results with a higher noise than the GPS results. This additional noise is shown to be due to some elevation-dependent delay in the BDS code measurements. Some biases were furthermore pointed out between the CV results obtained with the different BeiDou MEO satellites when the receivers used in the two stations are of different make. These biases may reach some nanoseconds, and find most probably their origin in the receiver hardware or firmware. It is shown additionally that using the BeiDou IGSO satellites and the GEO satellites, although increasing the number of observations, especially in the Asia-Pacific region, introduces a significant time transfer noise in the CV results.

Using modified fruit fly optimisation algorithm to perform the function test and case studies

NASA Astrophysics Data System (ADS)

Pan, Wen-Tsao

2013-06-01

Evolutionary computation is a computing mode established by practically simulating natural evolutionary processes based on the concept of Darwinian Theory, and it is a common research method. The main contribution of this paper was to reinforce the function of searching for the optimised solution using the fruit fly optimization algorithm (FOA), in order to avoid the acquisition of local extremum solutions. The evolutionary computation has grown to include the concepts of animal foraging behaviour and group behaviour. This study discussed three common evolutionary computation methods and compared them with the modified fruit fly optimization algorithm (MFOA). It further investigated the ability of the three mathematical functions in computing extreme values, as well as the algorithm execution speed and the forecast ability of the forecasting model built using the optimised general regression neural network (GRNN) parameters. The findings indicated that there was no obvious difference between particle swarm optimization and the MFOA in regards to the ability to compute extreme values; however, they were both better than the artificial fish swarm algorithm and FOA. In addition, the MFOA performed better than the particle swarm optimization in regards to the algorithm execution speed, and the forecast ability of the forecasting model built using the MFOA's GRNN parameters was better than that of the other three forecasting models.

Living with constipation--older people's experiences and strategies with constipation before and during hospitalization.

PubMed

Munch, Lene; Tvistholm, Nina; Trosborg, Ingelise; Konradsen, Hanne

2016-01-01

Constipation is a common problem among older people. This study aimed to explore how older patients experience constipation and which strategies they used in handling the condition before and during hospitalization. A qualitative exploratory research design was used. Fourteen semi-structured interviews were conducted with patients (61-91 years of age) during hospitalization. Data were analyzed by using content analysis. Themes concerning experiences were Bodily signs and symptoms of constipation; the participants described severe pain during constipation, as well as pronounced relief after bowel movements, Impact on well-being and social activities; being constipated negatively impacted their mood and limited social activities, Striving for bowel balance; the participants experienced an ongoing strive for balancing between constipation and diarrhea. Themes related to strategies were Struggling to find a solution; they were aware of different strategies to prevent and treat constipation, though the most common solution described was the use of laxatives, Wait and see; the participants were awaiting to take action until they experienced constipation symptoms, Constipation is a private problem being challenged during hospitalization; constipation was considered a private issue rarely discussed with health-care professionals. This study illuminates the need for health-care professionals to be attentive to this issue and initiate the conversation with patients in order to advise on the management of constipation.

Novel augmented reality solution for improving health literacy around antihypertensives in people living with type 2 diabetes mellitus: protocol of a technology evaluation study

PubMed Central

Ahmadvand, Alireza; Drennan, Judy; Burgess, Jean; Clark, Michele; Kavanagh, David; Burns, Kara; Howard, Sarah; Kelly, Fleur; Campbell, Chris; Nissen, Lisa

2018-01-01

Introduction Low health literacy is common in people with type 2 diabetes mellitus (T2DM) (up to 40%), associated with decreased self-efficacy in managing T2DM and its important complications, mainly hypertension. This study introduces, for the first time, an easy-to-use solution based on augmented reality (AR) on smartphones, to enhance health literacy around antihypertensive medicines. It assesses the feasibility of the solution for improving health literacy, oriented specifically to angiotensin II receptor blockers; embedding the health literacy improvement into the use cycle of angiotensin II receptor blockers and providing continuous access to information as a form of patient engagement. Methods and analysis This is a technology evaluation study with one technology group (AR plus usual care) and one non-technology group (usual care). Both groups receive face-to-face communications with community pharmacists regarding angiotensin II receptor blockers; the technology group receive additional AR-enhanced digital consumer medicine information throughout the use of their medications. The primary outcome is the change in health literacy and the hypothesis is that the proportions of people who show high health literacy will be larger in the technology group. Mixed effects models will be used to analyse solution effectiveness on outcomes. Multiple regression models will be used to find additional variables that might affect the relationship between health literacy and the AR solution. Ethics and dissemination Queensland University of Technology (QUT) Human Research Ethics Committee has approved the study as a low-risk technology evaluation study (approval number: 1700000275). Findings will be disseminated via attending scientific conferences and publishing in peer-reviewed journals. Facilitated by QUT, two press releases have been published in public media and two presentations have been made in university classrooms. PMID:29705754

Novel augmented reality solution for improving health literacy around antihypertensives in people living with type 2 diabetes mellitus: protocol of a technology evaluation study.

PubMed

Ahmadvand, Alireza; Drennan, Judy; Burgess, Jean; Clark, Michele; Kavanagh, David; Burns, Kara; Howard, Sarah; Kelly, Fleur; Campbell, Chris; Nissen, Lisa

2018-04-28

Low health literacy is common in people with type 2 diabetes mellitus (T2DM) (up to 40%), associated with decreased self-efficacy in managing T2DM and its important complications, mainly hypertension. This study introduces, for the first time, an easy-to-use solution based on augmented reality (AR) on smartphones, to enhance health literacy around antihypertensive medicines. It assesses the feasibility of the solution for improving health literacy, oriented specifically to angiotensin II receptor blockers; embedding the health literacy improvement into the use cycle of angiotensin II receptor blockers and providing continuous access to information as a form of patient engagement. This is a technology evaluation study with one technology group (AR plus usual care) and one non-technology group (usual care). Both groups receive face-to-face communications with community pharmacists regarding angiotensin II receptor blockers; the technology group receive additional AR-enhanced digital consumer medicine information throughout the use of their medications. The primary outcome is the change in health literacy and the hypothesis is that the proportions of people who show high health literacy will be larger in the technology group. Mixed effects models will be used to analyse solution effectiveness on outcomes. Multiple regression models will be used to find additional variables that might affect the relationship between health literacy and the AR solution. Queensland University of Technology (QUT) Human Research Ethics Committee has approved the study as a low-risk technology evaluation study (approval number: 1700000275). Findings will be disseminated via attending scientific conferences and publishing in peer-reviewed journals. Facilitated by QUT, two press releases have been published in public media and two presentations have been made in university classrooms. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Migration of DEHP from plastic to food simulants under microwave heating

NASA Astrophysics Data System (ADS)

Zhu, X.; Li, F.; Qiu, Z. Z.; Huang, J. W.

2017-05-01

The migration of plasticizer DEHP from the plastic products (4 kinds of commonly used plastic food containers under microwave heating: plastic wrap, food bags, ordinary plastic boxes, microwave special plastic boxes) through food contact materials to food simulants (isooctane, 10% ethanol-water solution (v/v), 3% acetic acid-water solution (w/w) and distilled water) was studied under microwave heating (power levels of 400 W). The results shows that the DEHP mobility increases with the increase of microwave heating time, DEHP mobility in isooctane and 3% acetic acid-water solution (w/w) is significantly greater than in 10% ethanol-water solution (v/v) and distilled water; the order of DEHP mobility in isooctane is plastic wrap>food bag>common plastic box>microwave-safe plastic box, while in 3% acetic acid (w/w), the order is food bag>common plastic box>microwave-safe plastic box>plastic wrap.

Ranked solutions to a class of combinatorial optimizations - with applications in mass spectrometry based peptide sequencing

NASA Astrophysics Data System (ADS)

Doerr, Timothy; Alves, Gelio; Yu, Yi-Kuo

2006-03-01

Typical combinatorial optimizations are NP-hard; however, for a particular class of cost functions the corresponding combinatorial optimizations can be solved in polynomial time. This suggests a way to efficiently find approximate solutions - - find a transformation that makes the cost function as similar as possible to that of the solvable class. After keeping many high-ranking solutions using the approximate cost function, one may then re-assess these solutions with the full cost function to find the best approximate solution. Under this approach, it is important to be able to assess the quality of the solutions obtained, e.g., by finding the true ranking of kth best approximate solution when all possible solutions are considered exhaustively. To tackle this statistical issue, we provide a systematic method starting with a scaling function generated from the fininte number of high- ranking solutions followed by a convergent iterative mapping. This method, useful in a variant of the directed paths in random media problem proposed here, can also provide a statistical significance assessment for one of the most important proteomic tasks - - peptide sequencing using tandem mass spectrometry data.

Evaluation and Adaptation of Attractive Toxic Sugar Baits For Culex tarsalis and Culex quinquefasciatus Control In The Coachella Valley, Southern California.

PubMed

Qualls, Whitney A; Scott-Fiorenzano, Jodi; Müller, Gunter C; Arheart, Kristopher L; Beier, John C; Xue, Rui-De

2016-12-01

The project goal was to determine how a new vector control strategy that targets the sugar-feeding behavior of mosquitoes, attractive toxic sugar baits (ATSBs), can be used to more effectively control West Nile virus (WNV) vectors in the Coachella Valley, California. Three laboratory studies were conducted to determine the utility of this method for control against Culex quinquefasciatus and Culex tarsalis : 1) efficacy evaluations of 2 formulations of ATSB, microencapsulated garlic oil, and a combination of microencapsulated garlic oil and 1% boric acid; 2) choice assays to determine the attractiveness of ATSB with the microencapsulated garlic oil against attractive sugar baits (ASB; the attractant alone; without toxin) and a 10% sucrose solution; and 3) vegetation efficacy tests on 3 common plant species in the Coachella Valley, Atriplex lentiformis, Tamarix ramosissima , and Pluchea sericea. At 48 h the average mortality for Cx. quinquefasciatus was 91% after exposure to ATSB with microencapsulated garlic oil and 99% on ATSB garlic + 1% boric acid solution. Culex tarsalis averaged 86% and 91% mortality following the ATSB microencapsulated garlic oil solution and the ATSB garlic + 1% boric acid solution, respectively. Choice assays indicated that the there were differences in preferences between the solutions and between species. Both Cx. quinquefasciatus and Cx. tarsalis were found to prefer the ASB and ATSB solutions to the 10% sucrose solution. However, when comparing the ASB to ATSB, Cx. quinquefasciatus significantly preferred the ASB solution (t = 3.6, df = 25, P = 0.0008). There were no significant differences in the preference of Cx. tarsalis to feed on the ASB or ATSB solutions as indicated in the choice assays (t = 1.9, df = 25, P = 0.07). Assays indicated that applications of ATSB to the 3 common plants in the Coachella Valley resulted in high mortality in both Cx. quinquefasciatus and Cx. tarsalis. There were significant differences in the treatments compared to the control (F = 40.15, df 1,2 = 4,72, P < 0.001) but no significant differences among the different plants and ATSB treatments (F = 1.06, df 1,2 = 4,72, P = 0.38). Laboratory findings suggest that ATSB is effective for use against WNV vectors in California. Further evaluations are needed in the field to determine how the environment may impact ATSB applications to influence mosquito mortality and nontarget organisms in arid environments in the United States.

From Efficacy Research to Large-Scale Impact on Undernutrition: The Role of Organizational Cultures12

PubMed Central

Pelletier, David; Pelto, Gretel

2013-01-01

Undernutrition in low-income countries is receiving unprecedented attention at global and national levels due to the convergence of many forces, including strong evidence concerning its magnitude, consequences, and potential solutions and effective advocacy by many organizations. The translation of this attention into large-scale reductions in undernutrition at the country level requires the alignment and support of many organizations in the development and implementation of a coherent policy agenda for nutrition, including the strengthening of operational and strategic capacities and a supportive research agenda. However, many countries experience difficulties achieving such alignment. This article uses the concept of organizational culture to better understand some of the reasons for these difficulties. This concept is applied to the constellation of organizations that make up the “National Nutrition Network” in a given country and some of the individual organizations within that network, including academic institutions that conduct research on undernutrition. We illustrate this concept through a case study involving a middle-income country. We conclude that efforts to align organizations in support of coherent nutrition agendas should do the following: 1) make intentional and sustained efforts to foster common understanding, shared learning, and socialization of new members and other elements of a shared culture among partners; 2) seek a way to frame problems and solutions in a fashion that enables individual organizations to secure some of their particular interests by joining the effort; and 3) not only advocate on the importance of nutrition but also insist that high-level officials hold organizations accountable for aligning in support of common-interest solutions (through some elements of a common culture) that can be effective and appropriate in the national context. We further conclude that a culture change is needed within academic departments if the discipline of nutrition is to play a central role in translating the findings from efficacy trials into large-scale reductions in undernutrition. PMID:24228200

From efficacy research to large-scale impact on undernutrition: the role of organizational cultures.

PubMed

Pelletier, David; Pelto, Gretel

2013-11-01

Undernutrition in low-income countries is receiving unprecedented attention at global and national levels due to the convergence of many forces, including strong evidence concerning its magnitude, consequences, and potential solutions and effective advocacy by many organizations. The translation of this attention into large-scale reductions in undernutrition at the country level requires the alignment and support of many organizations in the development and implementation of a coherent policy agenda for nutrition, including the strengthening of operational and strategic capacities and a supportive research agenda. However, many countries experience difficulties achieving such alignment. This article uses the concept of organizational culture to better understand some of the reasons for these difficulties. This concept is applied to the constellation of organizations that make up the "National Nutrition Network" in a given country and some of the individual organizations within that network, including academic institutions that conduct research on undernutrition. We illustrate this concept through a case study involving a middle-income country. We conclude that efforts to align organizations in support of coherent nutrition agendas should do the following: 1) make intentional and sustained efforts to foster common understanding, shared learning, and socialization of new members and other elements of a shared culture among partners; 2) seek a way to frame problems and solutions in a fashion that enables individual organizations to secure some of their particular interests by joining the effort; and 3) not only advocate on the importance of nutrition but also insist that high-level officials hold organizations accountable for aligning in support of common-interest solutions (through some elements of a common culture) that can be effective and appropriate in the national context. We further conclude that a culture change is needed within academic departments if the discipline of nutrition is to play a central role in translating the findings from efficacy trials into large-scale reductions in undernutrition.

Integrated system dynamics toolbox for water resources planning.

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

Reno, Marissa Devan; Passell, Howard David; Malczynski, Leonard A.

2006-12-01

Public mediated resource planning is quickly becoming the norm rather than the exception. Unfortunately, supporting tools are lacking that interactively engage the public in the decision-making process and integrate over the myriad values that influence water policy. In the pages of this report we document the first steps toward developing a specialized decision framework to meet this need; specifically, a modular and generic resource-planning ''toolbox''. The technical challenge lies in the integration of the disparate systems of hydrology, ecology, climate, demographics, economics, policy and law, each of which influence the supply and demand for water. Specifically, these systems, their associatedmore » processes, and most importantly the constitutive relations that link them must be identified, abstracted, and quantified. For this reason, the toolbox forms a collection of process modules and constitutive relations that the analyst can ''swap'' in and out to model the physical and social systems unique to their problem. This toolbox with all of its modules is developed within the common computational platform of system dynamics linked to a Geographical Information System (GIS). Development of this resource-planning toolbox represents an important foundational element of the proposed interagency center for Computer Aided Dispute Resolution (CADRe). The Center's mission is to manage water conflict through the application of computer-aided collaborative decision-making methods. The Center will promote the use of decision-support technologies within collaborative stakeholder processes to help stakeholders find common ground and create mutually beneficial water management solutions. The Center will also serve to develop new methods and technologies to help federal, state and local water managers find innovative and balanced solutions to the nation's most vexing water problems. The toolbox is an important step toward achieving the technology development goals of this center.« less

Using Markov Chains and Multi-Objective Optimization for Energy-Efficient Context Recognition.

PubMed

Janko, Vito; Luštrek, Mitja

2017-12-29

The recognition of the user's context with wearable sensing systems is a common problem in ubiquitous computing. However, the typically small battery of such systems often makes continuous recognition impractical. The strain on the battery can be reduced if the sensor setting is adapted to each context. We propose a method that efficiently finds near-optimal sensor settings for each context. It uses Markov chains to simulate the behavior of the system in different configurations and the multi-objective genetic algorithm to find a set of good non-dominated configurations. The method was evaluated on three real-life datasets and found good trade-offs between the system's energy expenditure and the system's accuracy. One of the solutions, for example, consumed five-times less energy than the default one, while sacrificing only two percentage points of accuracy.

Naked shell singularities on the brane

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

Seahra, Sanjeev S.

By utilizing nonstandard slicings of 5-dimensional Schwarzschild and Schwarzschild-AdS manifolds based on isotropic coordinates, we generate static and spherically-symmetric braneworld spacetimes containing shell-like naked null singularities. For planar slicings, we find that the brane-matter sourcing the solution is a perfect fluid with an exotic equation of state and a pressure singularity where the brane crosses the bulk horizon. From a relativistic point of view, such a singularity is required to maintain matter infinitesimally above the surface of a black hole. From the point of view of the AdS/CFT conjecture, the singular horizon can be seen as one possible quantum correctionmore » to a classical black hole geometry. Various generalizations of planar slicings are also considered for a Ricci-flat bulk, and we find that singular horizons and exotic matter distributions are common features.« less

Analytical solutions for sequentially coupled one-dimensional reactive transport problems Part I: Mathematical derivations

NASA Astrophysics Data System (ADS)

Srinivasan, V.; Clement, T. P.

2008-02-01

Multi-species reactive transport equations coupled through sorption and sequential first-order reactions are commonly used to model sites contaminated with radioactive wastes, chlorinated solvents and nitrogenous species. Although researchers have been attempting to solve various forms of these reactive transport equations for over 50 years, a general closed-form analytical solution to this problem is not available in the published literature. In Part I of this two-part article, we derive a closed-form analytical solution to this problem for spatially-varying initial conditions. The proposed solution procedure employs a combination of Laplace and linear transform methods to uncouple and solve the system of partial differential equations. Two distinct solutions are derived for Dirichlet and Cauchy boundary conditions each with Bateman-type source terms. We organize and present the final solutions in a common format that represents the solutions to both boundary conditions. In addition, we provide the mathematical concepts for deriving the solution within a generic framework that can be used for solving similar transport problems.

Complex Dynamics of an Impulsive Control System in which Predator Species Share a Common Prey

NASA Astrophysics Data System (ADS)

Pei, Yongzhen; Liu, Shaoying; Li, Changguo

2009-06-01

In an ecosystem, multiple predator species often share a common prey and the interactions between the predators are neutral. In view of this fact, we propose a three-species prey-predator system with the functional responses and impulsive controls to model the process of pest management. It is proved that the system has a locally stable pest-eradication periodic solution under the assumption that the impulsive period is less than some critical value. In particular, two single control strategies (biological control alone or chemical control alone) are proposed. Finally, we compare three pest control strategies and find that if we choose narrow-spectrum pesticides that are targeted to a specific pest’s life cycle to kill the pest, then the combined strategy is preferable. Numerical results show that our system has complex dynamics including period-doubling bifurcation, quasi-periodic oscillation, chaos, intermittency and crises.

Auditory opportunity and visual constraint enabled the evolution of echolocation in bats.

PubMed

Thiagavel, Jeneni; Cechetto, Clément; Santana, Sharlene E; Jakobsen, Lasse; Warrant, Eric J; Ratcliffe, John M

2018-01-08

Substantial evidence now supports the hypothesis that the common ancestor of bats was nocturnal and capable of both powered flight and laryngeal echolocation. This scenario entails a parallel sensory and biomechanical transition from a nonvolant, vision-reliant mammal to one capable of sonar and flight. Here we consider anatomical constraints and opportunities that led to a sonar rather than vision-based solution. We show that bats' common ancestor had eyes too small to allow for successful aerial hawking of flying insects at night, but an auditory brain design sufficient to afford echolocation. Further, we find that among extant predatory bats (all of which use laryngeal echolocation), those with putatively less sophisticated biosonar have relatively larger eyes than do more sophisticated echolocators. We contend that signs of ancient trade-offs between vision and echolocation persist today, and that non-echolocating, phytophagous pteropodid bats may retain some of the necessary foundations for biosonar.

An assessment of the Nguyen and Pinder method for slug test analysis. [In situ estimates of ground water contamination

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

Butler, J.J. Jr.; Hyder, Z.

The Nguyen and Pinder method is one of four techniques commonly used for analysis of response data from slug tests. Limited field research has raised questions about the reliability of the parameter estimates obtained with this method. A theoretical evaluation of this technique reveals that errors were made in the derivation of the analytical solution upon which the technique is based. Simulation and field examples show that the errors result in parameter estimates that can differ from actual values by orders of magnitude. These findings indicate that the Nguyen and Pinder method should no longer be a tool in themore » repertoire of the field hydrogeologist. If data from a slug test performed in a partially penetrating well in a confined aquifer need to be analyzed, recent work has shown that the Hvorslev method is the best alternative among the commonly used techniques.« less

Self-assembled nanoparticle of common food constituents that carries a sparingly soluble small molecule.

PubMed

Bhopatkar, Deepak; Feng, Tao; Chen, Feng; Zhang, Genyi; Carignano, Marcelo; Park, Sung Hyun; Zhuang, Haining; Campanella, Osvaldo H; Hamaker, Bruce R

2015-05-06

A previously reported nanoparticle formed through the self-assembly of common food constituents (amylose, protein, and fatty acids) was shown to have the capacity to carry a sparingly soluble small molecule (1-naphthol) in a dispersed system. Potentiometric titration showed that 1-naphthol locates in the lumen of the amylose helix of the nanoparticle. This finding was further supported by calorimetric measurements, showing higher enthalpies of dissociation and reassociation in the presence of 1-naphthol. Visually, the 1-naphthol-loaded nanoparticle appeared to be well-dispersed in aqueous solution. Molecular dynamics simulation showed that the self-assembly was favorable, and at 500 ns, the 1-naphthol molecule resided in the helix of the amylose lumen in proximity to the hydrophobic tail of the fatty acid. Thus, sparingly soluble small molecules, such as some nutraceuticals or drugs, could be incorporated and delivered by this soft nanoparticle carrier.

Common Neurogenetic Diagnosis and Meso-Limbic Manipulation of Hypodopaminergic Function in Reward Deficiency Syndrome (RDS): Changing the Recovery Landscape.

PubMed

Blum, Kenneth; Febo, Marcelo; Badgaiyan, Rajendra D; Demetrovics, Zsolt; Simpatico, Thomas; Fahlke, Claudia; M, Oscar-Berman; Li, Mona; Dushaj, Kristina; Gold, Mark S

2017-01-01

In 1990, Blum and associates provided the first confirmed genetic link between the DRD2 polymorphisms and alcoholism. This finding was based on an earlier conceptual framework, which served as a blueprint for their seminal genetic association discovery they termed "Brain Reward Cascade." These findings were followed by a new way of understanding all addictive behaviors (substance and non-substance) termed "Reward Deficiency Syndrome" (RDS). RDS incorporates a complex multifaceted array of inheritable behaviors that are polygenic. In this review article, we attempt to clarify these terms and provide a working model to accurately diagnose and treat these unwanted behaviors. We are hereby proposing the development of a translational model we term "Reward Deficiency Solution System™" that incorporates neurogenetic testing and meso-limbic manipulation of a "hypodopaminergic" trait/state, which provides dopamine agonistic therapy (DAT) as well as reduced "dopamine resistance," while embracing "dopamine homeostasis." The result is better recovery and relapse prevention, despite DNA antecedents, which could impact the recovery process and relapse. Understanding the commonality of mental illness will transform erroneous labeling based on symptomatology, into a genetic and anatomical etiology. WC: 184.

Clobetasol propionate shampoo 0.05% and calcipotriol solution 0.005%: a randomized comparison of efficacy and safety in subjects with scalp psoriasis.

PubMed

Reygagne, P; Mrowietz, U; Decroix, J; de Waard-van der Spek, F B; Acebes, L Olmos; Figueiredo, A; Caputo, R; Poncet, M; Arsonnaud, S

2005-02-01

Scalp involvement in psoriatic patients represents a common issue. Treatment of the hairy skin requires adequate pharmaceutical formulations; hence, a new specific shampoo formulation of clobetasol propionate 0.05% was developed by Galderma R&D, Inc. For this multicenter, randomized, investigator-masked, parallel group study, 151 subjects with moderate to severe scalp psoriasis were randomized to 4 weeks of treatment with clobetasol propionate shampoo or calcipotriol solution. Clobetasol propionate demonstrated significantly superior efficacy to calcipotriol solution (total severity score: mean difference 0.51, 95% CI 0.05-0.97, p = 0.028; global severity score: mean difference 0.43, 95% CI 0.08-0.78, p = 0.016). Adverse events were more common in the calcipotriol group than in the clobetasol propionate shampoo group. Telangiectasia and skin atrophy did not differ significantly between treatments; however, a burning sensation was significantly more common in the calcipotriol solution group. Short contact therapy of scalp psoriasis with this new shampoo formulation of clobetasol propionate was significantly more effective and better tolerated than calcipotriol solution for the treatment of scalp psoriasis.

Finding all solutions of nonlinear equations using the dual simplex method

NASA Astrophysics Data System (ADS)

Yamamura, Kiyotaka; Fujioka, Tsuyoshi

2003-03-01

Recently, an efficient algorithm has been proposed for finding all solutions of systems of nonlinear equations using linear programming. This algorithm is based on a simple test (termed the LP test) for nonexistence of a solution to a system of nonlinear equations using the dual simplex method. In this letter, an improved version of the LP test algorithm is proposed. By numerical examples, it is shown that the proposed algorithm could find all solutions of a system of 300 nonlinear equations in practical computation time.

The “Common Solutions” Strategy of the Experiment Support group at CERN for the LHC Experiments

NASA Astrophysics Data System (ADS)

Girone, M.; Andreeva, J.; Barreiro Megino, F. H.; Campana, S.; Cinquilli, M.; Di Girolamo, A.; Dimou, M.; Giordano, D.; Karavakis, E.; Kenyon, M. J.; Kokozkiewicz, L.; Lanciotti, E.; Litmaath, M.; Magini, N.; Negri, G.; Roiser, S.; Saiz, P.; Saiz Santos, M. D.; Schovancova, J.; Sciabà, A.; Spiga, D.; Trentadue, R.; Tuckett, D.; Valassi, A.; Van der Ster, D. C.; Shiers, J. D.

2012-12-01

After two years of LHC data taking, processing and analysis and with numerous changes in computing technology, a number of aspects of the experiments’ computing, as well as WLCG deployment and operations, need to evolve. As part of the activities of the Experiment Support group in CERN's IT department, and reinforced by effort from the EGI-InSPIRE project, we present work aimed at common solutions across all LHC experiments. Such solutions allow us not only to optimize development manpower but also offer lower long-term maintenance and support costs. The main areas cover Distributed Data Management, Data Analysis, Monitoring and the LCG Persistency Framework. Specific tools have been developed including the HammerCloud framework, automated services for data placement, data cleaning and data integrity (such as the data popularity service for CMS, the common Victor cleaning agent for ATLAS and CMS and tools for catalogue/storage consistency), the Dashboard Monitoring framework (job monitoring, data management monitoring, File Transfer monitoring) and the Site Status Board. This talk focuses primarily on the strategic aspects of providing such common solutions and how this relates to the overall goals of long-term sustainability and the relationship to the various WLCG Technical Evolution Groups. The success of the service components has given us confidence in the process, and has developed the trust of the stakeholders. We are now attempting to expand the development of common solutions into the more critical workflows. The first is a feasibility study of common analysis workflow execution elements between ATLAS and CMS. We look forward to additional common development in the future.

Scientists and Faith Communities in Dialogue - Finding Common Ground to Care for our Common Home

NASA Astrophysics Data System (ADS)

Jablonski, L. M.

2017-12-01

World-wide, faith communities are a key place for education and outreach to the general adult population. The sacred responsibility to care for the earth, living sustainability and concern for the poor are nearly universal priorities across faith communities. Scientists and people of faith share in common experiences of awe and wonder and ethical roles as citizens. The majority of faith communities have statements on climate changes, environmental justice, and stewardship, and respond with education, action plans and advocacy. People of faith are increasingly seeking science expertise to better understand the science and best solutions to implement. Transformation of point of view often requires heart-felt motivation (domain of religion) as well as knowledge (science). Scientists can participate in alleviating environmental justice by providing data and education to communities. Expert testimony is a critical service. Pope Francis' environmental encyclical Laudato si, engaged diverse scientists in its writing and outreach. Francis invites our continued dialogue with people of faith and goodwill of all societal sectors and fields to achieve an integral ecology that integrates science, economics, and impacts on the poor. For scientists to be most effective in sharing expertise, and building understanding and trust in scientific findings, skill- building is needed in: communication, finding common ground, intercultural competency, working with diverse populations and religious literacy. Educational initiatives bridging scientists and faith-communities will be highlighted including within: the Ecological Society of America, American Assn for Advancement of Sustainability in Higher Education, faith-based & Environmental Justice networks, Nature centers, Higher Education (including Seminary) Initiatives and the Hanley Sustainability Institute, and interfaith religious organizations engaged with scientists. Bridge-building and ongoing partnerships of scientists, EJ-impacted community members and people of faith are critical to addressing climate change and its impacts and countering environmental injustice. Such partnerships can help achieve the UN Sustainable Development Goals which address both human rights and environmental sustainability.

Communication: On the calculation of time-dependent electron flux within the Born-Oppenheimer approximation: A flux-flux reflection principle

NASA Astrophysics Data System (ADS)

Albert, Julian; Hader, Kilian; Engel, Volker

2017-12-01

It is commonly assumed that the time-dependent electron flux calculated within the Born-Oppenheimer (BO) approximation vanishes. This is not necessarily true if the flux is directly determined from the continuity equation obeyed by the electron density. This finding is illustrated for a one-dimensional model of coupled electronic-nuclear dynamics. There, the BO flux is in perfect agreement with the one calculated from a solution of the time-dependent Schrödinger equation for the coupled motion. A reflection principle is derived where the nuclear BO flux is mapped onto the electronic flux.

Evaluation and Management of Dehydration in Children.

PubMed

Santillanes, Genevieve; Rose, Emily

2018-05-01

The article discusses the evaluation of dehydration in children and reviews the literature on physical findings of dehydration. Pediatric dehydration is a common problem in emergency departments and wide practice variation in treatment exists. Dehydration can be treated with oral, nasogastric, subcutaneous, or intravenous fluids. Although oral rehydration is underutilized in the United States, most children with dehydration can be successfully rehydrated via the oral route. Selection of oral rehydration solution and techniques for successful oral rehydration are presented. Appropriate selection and rate of administration of intravenous fluids are also discussed for isonatremic, hyponatremic, and hypernatremic dehydration. Copyright © 2017 Elsevier Inc. All rights reserved.

Sexual harassment on the job: psychological, social and economic repercussions.

PubMed

Gosselin, H L

1984-09-01

This article is an effort to shed new light on what has been commonly termed sexual harassment, to identify its forms and, most importantly, to explore its effect upon those who have been subjected to it. The author's hypothesis is that sexual harassment in the workplace is more a social phenomenon than a personal problem, and that it is the cause of lasting psychological, social and economic after-effects among its victims. Combatting sexual harassment is only part of the solution; we must look beyond its legal aspects to find ways of changing male-female occupational relationships, and we must provide support to victims of sexual harassment.

Postinflammatory hyperpigmentation: evolving combination treatment strategies.

PubMed

Taylor, Susan C; Burgess, Cheryl M; Callender, Valerie D; Fu, Jan; Rendon, Marta I; Roberts, Wendy E; Shalita, Alan R

2006-08-01

Postinflammatory hyperpigmentation (PIH) is a common acquired excess of pigment in the epidermal and/or dermal layers of the skin. Lesions persist for extended periods if untreated, thus therapy is warranted. Topical monotherapies include the standard bleaching agent hydroquinone (HQ) as well as retinoids. Recently, several fixed-dose combination products were introduced to the armamentarium: HQ 4%-retinol 0.15% in a microsponge formulation; HQ 4%-retinol 0.3%; mequinol 2%-tretinoin (RA) 0.01%; and fluocinolone acetonide (FA) 0.01%, HQ 4%, and RA 0.05%. Recent findings have suggested that mequinol 2%-RA 0.01% solution is a promising alternative for the treatment of PIH.

Design of linear quadratic regulators with eigenvalue placement in a specified region

NASA Technical Reports Server (NTRS)

Shieh, Leang-San; Zhen, Liu; Coleman, Norman P.

1990-01-01

Two linear quadratic regulators are developed for placing the closed-loop poles of linear multivariable continuous-time systems within the common region of an open sector, bounded by lines inclined at +/- pi/2k (for a specified integer k not less than 1) from the negative real axis, and the left-hand side of a line parallel to the imaginary axis in the complex s-plane, and simultaneously minimizing a quadratic performance index. The design procedure mainly involves the solution of either Liapunov equations or Riccati equations. The general expression for finding the lower bound of a constant gain gamma is also developed.

Analytical attractor and the divergence of the slow-roll expansion in relativistic hydrodynamics

NASA Astrophysics Data System (ADS)

Denicol, Gabriel S.; Noronha, Jorge

2018-03-01

We find the general analytical solution of the viscous relativistic hydrodynamic equations (in the absence of bulk viscosity and chemical potential) for a Bjorken expanding fluid with an ideal gas equation of state and a constant shear viscosity relaxation time. We analytically determine the hydrodynamic attractor of this fluid and discuss its properties. We show for the first time that the slow-roll expansion, a commonly used approach to characterize the attractor, diverges. This is shown to hold also in a conformal plasma. The gradient expansion is found to converge in an example where causality and stability are violated.

Efficacy of intravascular catheter lock solutions containing preservatives in the prevention of microbial colonization

PubMed Central

Shenep, L.E.; Shenep, M.A.; Cheatham, W.; Hoffman, J.M.; Hale, A.; Williams, B.F.; Perkins, R.; Hewitt, C.B.; Hayden, R.T.; Shenep, J. L.

2016-01-01

SUMMARY There is little published evidence regarding whether heparin lock solutions containing preservatives prevent catheter-related infections. However, adverse effects from preservative-containing flushes have been documented in neonates, leading many hospitals to avoid their use altogether. Infection control records from 1982 to 2008 at St. Jude Children’s Research Hospital (SJCRH) were reviewed regarding the incidence of CRIs and the use of preservative-containing intravenous locks. In addition, the antimicrobial activities of heparin lock solution containing the preservatives parabens (0.165%) or benzyl alcohol (0.9%), and 70% ethanol were examined against Staphylococcus epidermidis, Staphylococcus aureus, Escherichia coli, Bacillus cereus, Pseudomonas aeruginosa and Candida albicans, and compared with preservative-free saline with and without heparin. Growth was assessed after exposure to test solutions for 0, 2, 4 and 24 h at 35°C. The activities of preservatives were assessed against both planktonic (free-floating) and sessile (biofilm-embedded) micro-organisms using the MBEC Assay. Infection control records revealed two periods of increased catheter-related infections, corresponding with two intervals when preservative-free heparin was used at SJCRH. Heparin solution containing preservatives demonstrated significant antimicrobial activity against both planktonic and sessile forms of all six microbial species. Ethanol demonstrated the greatest antimicrobial activity, especially following short incubation periods. Heparin lock solutions containing the preservatives parabens or benzyl alcohol, and 70% ethanol demonstrated significant antimicrobial activity against both planktonic and sessile micro-organisms commonly responsible for CRIs. These findings, together with the authors’ historical infection control experience, support the use of preservatives in intravenous lock solutions to reduce catheter related infections in patients beyond the neonatal period. PMID:21945067

Efficacy of intravascular catheter lock solutions containing preservatives in the prevention of microbial colonization.

PubMed

Shenep, L E; Shenep, M A; Cheatham, W; Hoffman, J M; Hale, A; Williams, B F; Perkins, R; Hewitt, C B; Hayden, R T; Shenep, J L

2011-12-01

There is little published evidence regarding whether heparin lock solutions containing preservatives prevent catheter-related infections. However, adverse effects from preservative-containing flushes have been documented in neonates, leading many hospitals to avoid their use altogether. Infection control records from 1982 to 2008 at St. Jude Children's Research Hospital (SJCRH) were reviewed regarding the incidence of catheter-related infections and the use of preservative-containing intravenous locks. In addition, the antimicrobial activities of heparin lock solution containing the preservatives parabens (0.165%) or benzyl alcohol (0.9%), and 70% ethanol were examined against Staphylococcus epidermidis, Staphylococcus aureus, Escherichia coli, Bacillus cereus, Pseudomonas aeruginosa and Candida albicans, and compared with preservative-free saline with and without heparin. Growth was assessed after exposure to test solutions for 0, 2, 4 and 24h at 35 °C. The activities of preservatives were assessed against both planktonic (free-floating) and sessile (biofilm-embedded) micro-organisms using the MBEC Assay. Infection control records revealed two periods of increased catheter-related infections, corresponding with two intervals when preservative-free heparin was used at SJCRH. Heparin solution containing preservatives demonstrated significant antimicrobial activity against both planktonic and sessile forms of all six microbial species. Ethanol demonstrated the greatest antimicrobial activity, especially following short incubation periods. Heparin lock solutions containing the preservatives parabens or benzyl alcohol, and 70% ethanol demonstrated significant antimicrobial activity against both planktonic and sessile micro-organisms commonly responsible for catheter-related infections. These findings, together with the authors' historical infection control experience, support the use of preservatives in intravenous lock solutions to reduce catheter related infections in patients beyond the neonatal period. Copyright © 2011 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

The effect of topical treatments for CRS on the sinonasal epithelial barrier.

PubMed

Ramezanpour, M; Rayan, A; Smith, J L P; Vreugde, S

2017-06-01

Several topical treatments are used in the management of Chronic Rhinosinusitis (CRS), some of which the safety and efficacy has yet to be determined. The purpose of this study was to investigate the effect of commonly used topical treatments on the sinonasal epithelial barrier. Normal saline (0.9% Sodium Chloride), hypertonic saline (3% Sodium Chloride), FESS Sinu-Cleanse Hypertonic, FLO Sinus Care and Budesonide 1 mg/ 2 ml were applied to the apical side of air-liquid interface (ALI) cultures of primary human nasal epithelial cells (HNECs) from CRS patients (n=3) and non-CRS controls (n=3) for 24 hours. Epithelial barrier structure and function was assessed using trans-epithelial electrical resistance (TEER), measuring the passage of Fluorescein Isothiocyanate labelled Dextrans (FITC-Dextrans) and assessing the expression of the tight junction protein Zona Occludens-1 (ZO-1) using immunofluorescence. Toxicity was assessed using a Lactate Dehydrogenase (LDH) assay. Data was analysed using ANOVA, followed by Tukey HSD post hoc test. Hypertonic solution and budesonide significantly increased TEER values in CRS derived HNECs. In contrast, FESS Sinu-Cleanse Hypertonic significantly reduced TEER 5 minutes after application of the solution followed by an increase in paracellular permeability of FITC-Dextrans (30 minutes) and increased LDH levels 6 hours after application of the solution. Our findings confirm that isotonic and hypertonic saline solutions do not compromise epithelial barrier function in vitro but underscore the importance of examining safety and efficacy of over-the-counter wash solutions.

Sensitivity of polarization fluctuations to the nature of protein-water interactions: Study of biological water in four different protein-water systems

NASA Astrophysics Data System (ADS)

Ghosh, Rikhia; Banerjee, Saikat; Hazra, Milan; Roy, Susmita; Bagchi, Biman

2014-12-01

Since the time of Kirkwood, observed deviations in magnitude of the dielectric constant of aqueous protein solution from that of neat water (˜80) and slower decay of polarization have been subjects of enormous interest, controversy, and debate. Most of the common proteins have large permanent dipole moments (often more than 100 D) that can influence structure and dynamics of even distant water molecules, thereby affecting collective polarization fluctuation of the solution, which in turn can significantly alter solution's dielectric constant. Therefore, distance dependence of polarization fluctuation can provide important insight into the nature of biological water. We explore these aspects by studying aqueous solutions of four different proteins of different characteristics and varying sizes, chicken villin headpiece subdomain (HP-36), immunoglobulin binding domain protein G (GB1), hen-egg white lysozyme (LYS), and Myoglobin (MYO). We simulate fairly large systems consisting of single protein molecule and 20000-30000 water molecules (varied according to the protein size), providing a concentration in the range of ˜2-3 mM. We find that the calculated dielectric constant of the system shows a noticeable increment in all the cases compared to that of neat water. Total dipole moment auto time correlation function of water ⟨δMW(0)δMW(t)⟩ is found to be sensitive to the nature of the protein. Surprisingly, dipole moment of the protein and total dipole moment of the water molecules are found to be only weakly coupled. Shellwise decomposition of water molecules around protein reveals higher density of first layer compared to the succeeding ones. We also calculate heuristic effective dielectric constant of successive layers and find that the layer adjacent to protein has much lower value (˜50). However, progressive layers exhibit successive increment of dielectric constant, finally reaching a value close to that of bulk 4-5 layers away. We also calculate shellwise orientational correlation function and tetrahedral order parameter to understand the local dynamics and structural re-arrangement of water. Theoretical analysis providing simple method for calculation of shellwise local dielectric constant and implication of these findings are elaborately discussed in the present work.

SYNTHESIS OF NOVEL ALL-DIELECTRIC GRATING FILTERS USING GENETIC ALGORITHMS

NASA Technical Reports Server (NTRS)

Zuffada, Cinzia; Cwik, Tom; Ditchman, Christopher

1997-01-01

We are concerned with the design of inhomogeneous, all dielectric (lossless) periodic structures which act as filters. Dielectric filters made as stacks of inhomogeneous gratings and layers of materials are being used in optical technology, but are not common at microwave frequencies. The problem is then finding the periodic cell's geometric configuration and permittivity values which correspond to a specified reflectivity/transmittivity response as a function of frequency/illumination angle. This type of design can be thought of as an inverse-source problem, since it entails finding a distribution of sources which produce fields (or quantities derived from them) of given characteristics. Electromagnetic sources (electric and magnetic current densities) in a volume are related to the outside fields by a well known linear integral equation. Additionally, the sources are related to the fields inside the volume by a constitutive equation, involving the material properties. Then, the relationship linking the fields outside the source region to those inside is non-linear, in terms of material properties such as permittivity, permeability and conductivity. The solution of the non-linear inverse problem is cast here as a combination of two linear steps, by explicitly introducing the electromagnetic sources in the computational volume as a set of unknowns in addition to the material unknowns. This allows to solve for material parameters and related electric fields in the source volume which are consistent with Maxwell's equations. Solutions are obtained iteratively by decoupling the two steps. First, we invert for the permittivity only in the minimization of a cost function and second, given the materials, we find the corresponding electric fields through direct solution of the integral equation in the source volume. The sources thus computed are used to generate the far fields and the synthesized triter response. The cost function is obtained by calculating the deviation between the synthesized value of reflectivity/transmittivity and the desired one. Solution geometries for the periodic cell are sought as gratings (ensembles of columns of different heights and widths), or combinations of homogeneous layers of different dielectric materials and gratings. Hence the explicit unknowns of the inversion step are the material permittivities and the relative boundaries separating homogeneous parcels of the periodic cell.

Extinction efficiencies from DDA calculations solved for finite circular cylinders and disks

NASA Technical Reports Server (NTRS)

Withrow, J. R.; Cox, S. K.

1993-01-01

One of the most commonly noted uncertainties with respect to the modeling of cirrus clouds and their effect upon the planetary radiation balance is the disputed validity of the use of Mie scattering results as an approximation to the scattering results of the hexagonal plates and columns found in cirrus clouds. This approximation has historically been a kind of default, a result of the lack of an appropriate analytical solution of Maxwell's equations to particles other than infinite cylinders and spheroids. Recently, however, the use of such approximate techniques as the Discrete Dipole Approximation has made scattering solutions on such particles a computationally intensive but feasible possibility. In this study, the Discrete Dipole Approximation (DDA) developed by Flatau (1992) is used to find such solutions for homogeneous, circular cylinders and disks. This can serve to not only assess the validity of the current radiative transfer schemes which are available for the study of cirrus but also to extend the current approximation of equivalent spheres to an approximation of second order, homogeneous finite circular cylinders and disks. The results will be presented in the form of a single variable, the extinction efficiency.

Children's self-assessment of performance and task-related help seeking.

PubMed

Nelson-Le Gall, S; Kratzer, L; Jones, E; DeCooke, P

1990-04-01

The present research examined the role of self-assessment of performance on children's use of help-seeking as an achievement strategy. In two experiments, third- and fifth-grade children were blocked into low and high verbal skill groups. Children performed a multitrial verbal task in which they were required to indicate their confidence in the correctness of their tentative solution and then were given the opportunity to seek help before providing a final solution on each trial. The second experiment differed from the first in that subjects were provided with a common motivation for seeking help. Subjects' confidence in the correctness of their solution was found to influence both the frequency and type of help sought. High task-related skill was associated with the discriminating use of help-seeking as an achievement strategy, especially among boys. Also, both the frequency and type of help sought varied with self-assessments for older children more than for younger children. Findings are discussed in terms of grade and sex differences in the use of internally based cues for performance evaluation. The importance of accounting for the interplay of children's age and task specific skill with achievement-related goals is stressed.

Random lasing actions in self-assembled perovskite nanoparticles

NASA Astrophysics Data System (ADS)

Liu, Shuai; Sun, Wenzhao; Li, Jiankai; Gu, Zhiyuan; Wang, Kaiyang; Xiao, Shumin; Song, Qinghai

2016-05-01

Solution-based perovskite nanoparticles have been intensively studied in the past few years due to their applications in both photovoltaic and optoelectronic devices. Here, based on the common ground between solution-based perovskite and random lasers, we have studied the mirrorless lasing actions in self-assembled perovskite nanoparticles. After synthesis from a solution, discrete lasing peaks have been observed from optically pumped perovskites without any well-defined cavity boundaries. We have demonstrated that the origin of the random lasing emissions is the scattering between the nanostructures in the perovskite microplates. The obtained quality (Q) factors and thresholds of random lasers are around 500 and 60 μJ/cm2, respectively. Both values are comparable to the conventional perovskite microdisk lasers with polygon-shaped cavity boundaries. From the corresponding studies on laser spectra and fluorescence microscope images, the lasing actions are considered random lasers that are generated by strong multiple scattering in random gain media. In additional to conventional single-photon excitation, due to the strong nonlinear effects of perovskites, two-photon pumped random lasers have also been demonstrated for the first time. We believe this research will find its potential applications in low-cost coherent light sources and biomedical detection.

System design and improvement of an emergency department using Simulation-Based Multi-Objective Optimization

NASA Astrophysics Data System (ADS)

Goienetxea Uriarte, A.; Ruiz Zúñiga, E.; Urenda Moris, M.; Ng, A. H. C.

2015-05-01

Discrete Event Simulation (DES) is nowadays widely used to support decision makers in system analysis and improvement. However, the use of simulation for improving stochastic logistic processes is not common among healthcare providers. The process of improving healthcare systems involves the necessity to deal with trade-off optimal solutions that take into consideration a multiple number of variables and objectives. Complementing DES with Multi-Objective Optimization (SMO) creates a superior base for finding these solutions and in consequence, facilitates the decision-making process. This paper presents how SMO has been applied for system improvement analysis in a Swedish Emergency Department (ED). A significant number of input variables, constraints and objectives were considered when defining the optimization problem. As a result of the project, the decision makers were provided with a range of optimal solutions which reduces considerably the length of stay and waiting times for the ED patients. SMO has proved to be an appropriate technique to support healthcare system design and improvement processes. A key factor for the success of this project has been the involvement and engagement of the stakeholders during the whole process.

Efficient Optimization of Low-Thrust Spacecraft Trajectories

NASA Technical Reports Server (NTRS)

Lee, Seungwon; Fink, Wolfgang; Russell, Ryan; Terrile, Richard; Petropoulos, Anastassios; vonAllmen, Paul

2007-01-01

A paper describes a computationally efficient method of optimizing trajectories of spacecraft driven by propulsion systems that generate low thrusts and, hence, must be operated for long times. A common goal in trajectory-optimization problems is to find minimum-time, minimum-fuel, or Pareto-optimal trajectories (here, Pareto-optimality signifies that no other solutions are superior with respect to both flight time and fuel consumption). The present method utilizes genetic and simulated-annealing algorithms to search for globally Pareto-optimal solutions. These algorithms are implemented in parallel form to reduce computation time. These algorithms are coupled with either of two traditional trajectory- design approaches called "direct" and "indirect." In the direct approach, thrust control is discretized in either arc time or arc length, and the resulting discrete thrust vectors are optimized. The indirect approach involves the primer-vector theory (introduced in 1963), in which the thrust control problem is transformed into a co-state control problem and the initial values of the co-state vector are optimized. In application to two example orbit-transfer problems, this method was found to generate solutions comparable to those of other state-of-the-art trajectory-optimization methods while requiring much less computation time.

Determinants of Erythrocyte Hydration In Current Opinion in Hematology

PubMed Central

Rinehart, Jesse; Gulcicek, Erol E.; Joiner, Clinton H.; Lifton, Richard P.; Gallagher, Patrick G.

2012-01-01

Purpose of Review Maintenance of cellular water and solute homeostasis is critical for survival of the erythrocyte. Inherited or acquired disorders that perturb this homeostasis jeopardize the erythrocyte, leading to its premature destruction. This report reviews recent progress in our understanding the determinants of erythrocyte hydration and its related disorders. Recent Findings The molecular and genetic bases of primary disorders of erythrocyte hydration are poorly understood. Recent studies have implicated roles for the anion transporter, SLC4A1, and the Rh-associated glycoprotein, RhAG. The most common secondary disorder associated with perturbed hydration of the erythrocyte is sickle cell disease, where dehydration contributes to disease pathology and clinical complications. Advances in understanding the mechanisms regulating erythrocyte solute and water content, particularly associated with KCl cotransport and Gardos channel activation, have revealed novel signaling mechanisms controlling erythrocyte hydration. These signaling pathways may provide innovative strategies to prevent erythrocyte dehydration in sickle cell disease. Summary Clinical, translational and biologic studies all contribute to our knowledge of erythrocyte hydration. Understanding the mechanisms controlling erythrocyte water and solute homeostasis will serve as a paradigm for other cells and may reveal new therapeutic targets for disease prevention and treatment. PMID:20182354

Designing a better weather display

NASA Astrophysics Data System (ADS)

Ware, Colin; Plumlee, Matthew

2012-01-01

The variables most commonly displayed on weather maps are atmospheric pressure, wind speed and direction, and surface temperature. But they are usually shown separately, not together on a single map. As a design exercise, we set the goal of finding out if it is possible to show all three variables (two 2D scalar fields and a 2D vector field) simultaneously such that values can be accurately read using keys for all variables, a reasonable level of detail is shown, and important meteorological features stand out clearly. Our solution involves employing three perceptual "channels", a color channel, a texture channel, and a motion channel in order to perceptually separate the variables and make them independently readable. We conducted an experiment to evaluate our new design both against a conventional solution, and against a glyph-based solution. The evaluation tested the abilities of novice subjects both to read values using a key, and to see meteorological patterns in the data. Our new scheme was superior especially in the representation of wind patterns using the motion channel, and it also performed well enough in the representation of pressure using the texture channel to suggest it as a viable design alternative.

ReacKnock: Identifying Reaction Deletion Strategies for Microbial Strain Optimization Based on Genome-Scale Metabolic Network

PubMed Central

Xu, Zixiang; Zheng, Ping; Sun, Jibin; Ma, Yanhe

2013-01-01

Gene knockout has been used as a common strategy to improve microbial strains for producing chemicals. Several algorithms are available to predict the target reactions to be deleted. Most of them apply mixed integer bi-level linear programming (MIBLP) based on metabolic networks, and use duality theory to transform bi-level optimization problem of large-scale MIBLP to single-level programming. However, the validity of the transformation was not proved. Solution of MIBLP depends on the structure of inner problem. If the inner problem is continuous, Karush-Kuhn-Tucker (KKT) method can be used to reformulate the MIBLP to a single-level one. We adopt KKT technique in our algorithm ReacKnock to attack the intractable problem of the solution of MIBLP, demonstrated with the genome-scale metabolic network model of E. coli for producing various chemicals such as succinate, ethanol, threonine and etc. Compared to the previous methods, our algorithm is fast, stable and reliable to find the optimal solutions for all the chemical products tested, and able to provide all the alternative deletion strategies which lead to the same industrial objective. PMID:24348984

76 FR 44855 - Common or Usual Name for Raw Meat and Poultry Products Containing Added Solutions

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-27

.... FSIS-2010-0012] RIN 0583-AD41 Common or Usual Name for Raw Meat and Poultry Products Containing Added... name for raw meat and poultry products that do not meet standard of identity regulations and to which... description of the raw meat or poultry component, the percentage of added solution incorporated into the raw...

Constructive Development of the Solutions of Linear Equations in Introductory Ordinary Differential Equations

ERIC Educational Resources Information Center

Mallet, D. G.; McCue, S. W.

2009-01-01

The solution of linear ordinary differential equations (ODEs) is commonly taught in first-year undergraduate mathematics classrooms, but the understanding of the concept of a solution is not always grasped by students until much later. Recognizing what it is to be a solution of a linear ODE and how to postulate such solutions, without resorting to…

Diffusivity of Carbon Dioxide in Aqueous Solutions under Geologic Carbon Sequestration Conditions.

PubMed

Perera, Pradeep N; Deng, Hang; Schuck, P James; Gilbert, Benjamin

2018-04-26

Accurate assessment of the long-term security of geologic carbon sequestration requires knowledge of the mobility of carbon dioxide in brines under pressure and temperature conditions that prevail in subsurface aquifers. Here, we report Raman spectroscopic measurements of the rate of CO 2 diffusion in water and brines as a function of pressure, salinity, and concentration of CO 2 . In pure water at 50 ± 2 °C and 90 ± 2 bar, we find the diffusion coefficient, D, to be (3.08 ± 0.03) × 10 -9 m 2 /s, a value that is consistent with a recent microfluidic study but lower than earlier PVT measurements. Under reservoir conditions, salinity affects the mobility of CO 2 significantly and D decreased by 45% for a 4 M solution of NaCl. We find significant differences of diffusivity of CO 2 in brines (0-4 M NaCl), in both the absolute values and the trend compared to the Stokes-Einstein prediction under our experimental conditions. We observe that D decreases significantly at the high CO 2 concentrations expected in subsurface aquifers (∼15% reduction at 0.55 mol/kg of CO 2 ) and provides an empirical correction to the commonly reported D values that assume a tracer concentration dependence on diffusivity.

Environmental computing compendium - background and motivation

NASA Astrophysics Data System (ADS)

Heikkurinen, Matti; Kranzlmüller, Dieter

2017-04-01

The emerging discipline of environmental computing brings together experts in applied, advanced environmental modelling. The application domains address several fundamental societal challenges, ranging from disaster risk reduction to sustainability issues (such as food security on the global scale). The community has used an Intuitive, pragmatic approach when determining which initiatives are considered to "belong to the discipline". The community's growth is based on sharing of experiences and tools provides opportunities for reusing solutions or applying knowledge in new settings. Thus, limiting possible synergies by applying an arbitrary, formal definition to exclude some of the sources of solutions and knowledge would be counterproductive. However, the number of individuals and initiatives involved has grown to the level where a survey of initiatives and sub-themes they focus on is of interest. By surveying the project landscape and identifying common themes and building a shared vocabulary to describe them we can both communicate the relevance of the new discipline to the general public more easily and make it easier for the new members of the community to find the most promising collaboration partners. This talk presents the methodology and initial findings of the initial survey of the environmental computing initiatives and organisations, as well as approaches that could lead to an environmental computing compendium that would be a collaborative maintained shared resource of the environmental computing community.

The dimensional salience solution to the expectancy-value muddle: an extension.

PubMed

Newton, Joshua D; Newton, Fiona J; Ewing, Michael T

2014-01-01

The theory of reasoned action (TRA) specifies a set of expectancy-value, belief-based frameworks that underpin attitude (behavioural beliefs × outcome evaluations) and subjective norm (normative beliefs × motivation to comply). Unfortunately, the most common method for analysing these frameworks generates statistically uninterpretable findings, resulting in what has been termed the 'expectancy-value muddle'. Recently, however, a dimensional salience approach was found to resolve this muddle for the belief-based framework underpinning attitude. An online survey of 262 participants was therefore conducted to determine whether the dimensional salience approach could also be applied to the belief-based framework underpinning subjective norm. Results revealed that motivations to comply were greater for salient, as opposed to non-salient, social referents. The belief-based framework underpinning subjective norm was therefore represented by evaluating normative belief ratings for salient social referents. This modified framework was found to predict subjective norm, although predictions were greater when participants were forced to select five salient social referents rather than being free to select any number of social referents. These findings validate the use of the dimensional salience approach for examining the belief-based frameworks underpinning subjective norm. As such, this approach provides a complete solution to addressing the expectancy-value muddle in the TRA.

Infusion of solutions of pre-irradiated components in rats.

PubMed

Pappas, Georgina; Arnaud, Francoise; Haque, Ashraful; Kino, Tomoyuki; Facemire, Paul; Carroll, Erica; Auker, Charles; McCarron, Richard; Scultetus, Anke

2016-06-01

The objective of this study was to conduct a 14-day toxicology assessment for intravenous solutions prepared from irradiated resuscitation fluid components and sterile water. Healthy Sprague Dawley rats (7-10/group) were instrumented and randomized to receive one of the following Field IntraVenous Resuscitation (FIVR) or commercial fluids; Normal Saline (NS), Lactated Ringer's, 5% Dextrose in NS. Daily clinical observation, chemistry and hematology on days 1,7,14, and urinalysis on day 14 were evaluated for equivalence using a two sample t-test (p<0.05). A board-certified pathologist evaluated organ histopathology on day 14. Equivalence was established for all observation parameters, lactate, sodium, liver enzymes, creatinine, WBC and differential, and urinalysis values. Lack of equivalence for hemoglobin (p=0.055), pH (p=0.0955), glucose (p=0.0889), Alanine-Aminotransferase (p=0.1938), albumin (p=0.1311), and weight (p=0.0555, p=0.1896), was deemed not clinically relevant due to means within physiologically normal ranges. Common microscopic findings randomly distributed among animals of all groups were endocarditis/myocarditis and pulmonary lesions. These findings are consistent with complications due to long-term catheter use and suggest no clinically relevant differences in end-organ toxicity between animals infused with FIVR versus commercial fluids. Copyright © 2016 Elsevier GmbH. All rights reserved.

Assembly of Space CFRP Structures with Racing Sailing Boats Technology

NASA Astrophysics Data System (ADS)

Nieto, Jose; Yuste, Laura; Pipo, Alvaro; Santarsiero, Pablo; Bureo, Rafael

2014-06-01

Carbon Fiber Reinforced Plastic (CFRP) is commonly used in space applications to get structures with good mechanical performances and a reduced mass. Most of larger parts of spatial structures are already made of CFRP but the achieved weight saving may be jeopardized by the use of metallic brackets as joining elements. This paper describes the work carried out to study and evaluate ways of reducing weight and costs of the joints between structural elements commonly used in space applications.The main objective of this project is to adapt design solutions coming from the racing sailing boats technology to space applications: the use of out-of autoclave (OoA) cured CFRP joints. In addition to that other CFRP solution common in space business, 3D- RTM Bracket, has been evaluated.This development studies the manufacturing and assembly feasibility making use of these CFRP technologies.This study also compares traditional metallic solutions with innovative CFRP ones in terms of mechanical performances at elementary level. Weight and cost of presented solutions are also compared.

Common agents used to unblock blood clots within tympanostomy tubes: an ex vivo study and review of literature.

PubMed

Burke, Emily L; Walvekar, Rohan R; Lin, James; Hagan, Joseph; Kluka, Evelyn A

2009-12-01

To determine the efficacy of common solutions used to dissolve blood clots blocking tympanostomy tubes (TTs) of differing lengths and diameters. An ex vivo experimental study. Ear models were built by the study investigator. Tympanostomy tubes were inserted into the models and blocked with blood clots. Test solutions were applied to the blood clots, and time for clearance was recorded via microscopic visual confirmation. Richards T-tube had higher odds of unclogging than collar button tubes (odds ratio: 2.37, 95% confidence intervals 1.02-5.54, p=0.042). Vinegar and 3% hydrogen peroxide were most effective for Richards T-tubes and collar button tubes, respectively. Common solutions (vinegar and hydrogen peroxide) were more effective than antibiotic drops in clearing blood clot blocking TTs.

Mitigation measures to contain the environmental impact of urban areas: a bibliographic review moving from the life cycle approach.

PubMed

Belussi, Lorenzo; Barozzi, Benedetta

2015-12-01

The global environmental impact of urban areas has greatly increased over the years, due to the growth of urbanisation and the associated increase in management costs. There are several measures aimed at mitigating this impact that affect in different ways the environmental, economic and societal spheres. This article has analysed a selection of different mitigation measures, related to the built environment, according to the life cycle approach, aimed at identifying the procedural features chosen by the different authors and defining a common way to deal with this issue. In particular, all the individual single steps of a Life Cycle Assessment/Life Cycle Costing of the different studies are analysed and the results of the individual measures are highlighted. The analysis has shown how the scientific literature is mainly focused on the evaluation of the impact of technological solutions related to individual buildings (cool/green roof). Less interest is shown in the solutions for urban areas, while, as far as the impact on greenhouse gas emissions is concerned, some studies are shifting the target to a global scale. Due to the accuracy whereby the calculation of the impact indicators deals with and structures the life cycle methods, opportunities to compare studies developed by different authors are quite rare and hard to find. Hence the need to find a simple, intuitive and flexible scheme to combine some of the most useful results of the bibliographical studies, in a comparative outline of different technological solutions, which can support the decision-making phase through a rough assessment.

Electrophilicity: the "dark-side" of indole chemistry.

PubMed

Bandini, Marco

2013-08-28

Indole is by far one of the most popular heterocyclic scaffolds in nature. The intriguing and challenging molecular architectures of polycyclic, naturally occurring indolyl compounds constitute a continuous stimulus for development in organic synthesis. The field had a formidable boom across the new millennium when catalysis started revolutionizing the chemistry of indole, providing always more convincing and sustainable solutions to the selective "decoration" of this pharmacophore. A common guideline of these approaches relies on the intrinsic overexpression of electron density of the indole core. Despite less diffusion, the "dark-side" of indole reactivity, electrophilicity, has been also elegantly documented with direct applications towards the realization of specific interatomic connections that would be difficult to obtain by means of conventional indole reactivity. The present Perspective article summarizes the major findings that brought the research area from the pioneering findings of the 60s to the state of the art.

Using Markov Chains and Multi-Objective Optimization for Energy-Efficient Context Recognition †

PubMed Central

Janko, Vito

2017-01-01

The recognition of the user’s context with wearable sensing systems is a common problem in ubiquitous computing. However, the typically small battery of such systems often makes continuous recognition impractical. The strain on the battery can be reduced if the sensor setting is adapted to each context. We propose a method that efficiently finds near-optimal sensor settings for each context. It uses Markov chains to simulate the behavior of the system in different configurations and the multi-objective genetic algorithm to find a set of good non-dominated configurations. The method was evaluated on three real-life datasets and found good trade-offs between the system’s energy expenditure and the system’s accuracy. One of the solutions, for example, consumed five-times less energy than the default one, while sacrificing only two percentage points of accuracy. PMID:29286301

Role of multiple representations in physics problem solving

NASA Astrophysics Data System (ADS)

Maries, Alexandru

This thesis explores the role of multiple representations in introductory physics students' problem solving performance through several investigations. Representations can help students focus on the conceptual aspects of physics and play a major role in effective problem solving. Diagrammatic representations can play a particularly important role in the initial stages of conceptual analysis and planning of the problem solution. Findings suggest that students who draw productive diagrams are more successful problem solvers even if their approach is primarily mathematical. Furthermore, students provided with a diagram of the physical situation presented in a problem sometimes exhibited deteriorated performance. Think-aloud interviews suggest that this deteriorated performance is in part due to reduced conceptual planning time which caused students to jump to the implementation stage without fully understanding the problem and planning problem solution. Another study investigated two interventions aimed at improving introductory students' representational consistency between mathematical and graphical representations and revealed that excessive scaffolding can have a detrimental effect. The detrimental effect was partly due to increased cognitive load brought on by the additional steps and instructions. Moreover, students who exhibited representational consistency also showed improved problem solving performance. The final investigation is centered on a problem solving task designed to provide information about the pedagogical content knowledge (PCK) of graduate student teaching assistants (TAs). In particular, the TAs identified what they considered to be the most common difficulties of introductory physics students related to graphical representations of kinematics concepts as they occur in the Test of Understanding Graphs in Kinematics (TUG-K). As an extension, the Force Concept Inventory (FCI) was also used to assess this aspect of PCK related to knowledge of student difficulties of both physics instructors and TAs. We find that teaching an independent course and recent teaching experience do not correlate with improved PCK. In addition, the performance of American TAs, Chinese TAs and other foreign TAs in identifying common student difficulties both in the context of the TUG-K and in the context of the FCI is similar. Moreover, there were many common difficulties of introductory physics students that were not identified by many instructors and TAs.

Classes of exact Einstein Maxwell solutions

NASA Astrophysics Data System (ADS)

Komathiraj, K.; Maharaj, S. D.

2007-12-01

We find new classes of exact solutions to the Einstein Maxwell system of equations for a charged sphere with a particular choice of the electric field intensity and one of the gravitational potentials. The condition of pressure isotropy is reduced to a linear, second order differential equation which can be solved in general. Consequently we can find exact solutions to the Einstein Maxwell field equations corresponding to a static spherically symmetric gravitational potential in terms of hypergeometric functions. It is possible to find exact solutions which can be written explicitly in terms of elementary functions, namely polynomials and product of polynomials and algebraic functions. Uncharged solutions are regainable with our choice of electric field intensity; in particular we generate the Einstein universe for particular parameter values.

Nonconvex Sparse Logistic Regression With Weakly Convex Regularization

NASA Astrophysics Data System (ADS)

Shen, Xinyue; Gu, Yuantao

2018-06-01

In this work we propose to fit a sparse logistic regression model by a weakly convex regularized nonconvex optimization problem. The idea is based on the finding that a weakly convex function as an approximation of the $\\ell_0$ pseudo norm is able to better induce sparsity than the commonly used $\\ell_1$ norm. For a class of weakly convex sparsity inducing functions, we prove the nonconvexity of the corresponding sparse logistic regression problem, and study its local optimality conditions and the choice of the regularization parameter to exclude trivial solutions. Despite the nonconvexity, a method based on proximal gradient descent is used to solve the general weakly convex sparse logistic regression, and its convergence behavior is studied theoretically. Then the general framework is applied to a specific weakly convex function, and a necessary and sufficient local optimality condition is provided. The solution method is instantiated in this case as an iterative firm-shrinkage algorithm, and its effectiveness is demonstrated in numerical experiments by both randomly generated and real datasets.

[Motivation effect on power changes in the brain biopotentials in the figurative and verbal creativity tasks].

PubMed

Razumnikova, O M; Vol'f, N V; Tarasova, I V

2007-01-01

Effect of extrinsic motivation stimulating the most original problem solving during verbal and figurative divergent thinking was studied by EEG mapping. The righthanded university students (27 males and 26 females) participated in the experiments. An instruction "to create the most original solution" as compared to condition with an instruction "to create any solution" induced an increase in the baseline power of the alpha 1 and alpha 2 rhythms most pronounced in the posterior cortex. Task-related desynchronization of the alpha rhythms was higher but the beta-2 synchronization was lower after the former than after the latter instruction. Differences in the asymmetry of the alpha 1 and alpha 2 rhythms in the parietal and temporal regions of hemispheres suggested the right hemisphere dominance in intrinsic alertness and evoked activation related to divergent thinking. The findings were common and gender-independent in both figurative and verbal tasks suggesting a generalized influence of extrinsic motivation on creative activity.

HolT Hunter: Software for Identifying and Characterizing Low-Strain DNA Holliday Triangles

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

Sherman W. B.

2012-06-05

Synthetic DNA nanostructures are most commonly held together via Holliday junctions. These junctions allow for a wide variety of different angles between the double helices they connect. Nevertheless, only constructs with a very limited selection of angles have been built, to date, because of the computational complexity of identifying structures that fit together with low strain at odd angles. I have developed an algorithm that finds over 95% of the possible solutions by breaking the problem down into two portions. First, there is a problem of how smooth rods can form triangles by lying across one another. This problem ismore » easily handled by numerical computation. Second, there is the question of how distorted DNA double helices would need to be to fit onto the rod structure. This strain is calculated directly. The algorithm has been implemented in a Mathematica 8 notebook called Holliday Triangle Hunter. A large database of solutions has been identified. Additional interface software is available to facilitate drawing and viewing models.« less

Discrimination of sweeteners based on the refractometric analysis

NASA Astrophysics Data System (ADS)

Bodurov, I.; Vlaeva, I.; Viraneva, A.; Yovcheva, T.

2017-01-01

In the present work, the refractive characteristics of aqueous solutions of several sweeteners are investigated. These data in combination with ones from other sensors should find application for brief determination of sweeteners content in food and dynamic monitoring of food quality. The refractive indices of pure (distilled) water and aqueous solutions of several commonly used natural and artificial sweeteners (glucose, fructose, sucrose, lactose, sorbitol [E420], isomalt [E953], saccharin sodium [E950], cyclamate sodium and glycerol [E422]) with 10 wt.% concentration are accurately measured at 405 nm, 532 nm and 632.8 nm wavelengths. The measurements are carried out using three wavelength laser microrefractometer based on the total internal reflection method. The critical angle is determined by the disappearance of the diffraction orders from a metal grating. The experimental uncertainty is less than ±0.0001. The dispersion dependences of the refractive indices are obtained using the one-term Sellmeier model. Based on the obtained experimental data additional refractive and dispersion characteristics are calculated.

Numerical Solutions of the Mean-Value Theorem: New Methods for Downward Continuation of Potential Fields

NASA Astrophysics Data System (ADS)

Zhang, Chong; Lü, Qingtian; Yan, Jiayong; Qi, Guang

2018-04-01

Downward continuation can enhance small-scale sources and improve resolution. Nevertheless, the common methods have disadvantages in obtaining optimal results because of divergence and instability. We derive the mean-value theorem for potential fields, which could be the theoretical basis of some data processing and interpretation. Based on numerical solutions of the mean-value theorem, we present the convergent and stable downward continuation methods by using the first-order vertical derivatives and their upward continuation. By applying one of our methods to both the synthetic and real cases, we show that our method is stable, convergent and accurate. Meanwhile, compared with the fast Fourier transform Taylor series method and the integrated second vertical derivative Taylor series method, our process has very little boundary effect and is still stable in noise. We find that the characters of the fading anomalies emerge properly in our downward continuation with respect to the original fields at the lower heights.

Direction dependence of displacement time for two-fluid electroosmotic flow.

PubMed

Lim, Chun Yee; Lam, Yee Cheong

2012-03-01

Electroosmotic flow that involves one fluid displacing another fluid is commonly encountered in various microfludic applications and experiments, for example, current monitoring technique to determine zeta potential of microchannel. There is experimentally observed anomaly in such flow, namely, the displacement time is flow direction dependent, i.e., it depends if it is a high concentration fluid displacing a low concentration fluid, or vice versa. Thus, this investigation focuses on the displacement flow of two fluids with various concentration differences. The displacement time was determined experimentally with current monitoring method. It is concluded that the time required for a high concentration solution to displace a low concentration solution is smaller than the time required for a low concentration solution to displace a high concentration solution. The percentage displacement time difference increases with increasing concentration difference and independent of the length or width of the channel and the voltage applied. Hitherto, no theoretical analysis or numerical simulation has been conducted to explain this phenomenon. A numerical model based on finite element method was developed to explain the experimental observations. Simulations showed that the velocity profile and ion distribution deviate significantly from a single fluid electroosmotic flow. The distortion of ion distribution near the electrical double layer is responsible for the displacement time difference for the two different flow directions. The trends obtained from simulations agree with the experimental findings.

Direction dependence of displacement time for two-fluid electroosmotic flow

PubMed Central

Lim, Chun Yee; Lam, Yee Cheong

2012-01-01

Electroosmotic flow that involves one fluid displacing another fluid is commonly encountered in various microfludic applications and experiments, for example, current monitoring technique to determine zeta potential of microchannel. There is experimentally observed anomaly in such flow, namely, the displacement time is flow direction dependent, i.e., it depends if it is a high concentration fluid displacing a low concentration fluid, or vice versa. Thus, this investigation focuses on the displacement flow of two fluids with various concentration differences. The displacement time was determined experimentally with current monitoring method. It is concluded that the time required for a high concentration solution to displace a low concentration solution is smaller than the time required for a low concentration solution to displace a high concentration solution. The percentage displacement time difference increases with increasing concentration difference and independent of the length or width of the channel and the voltage applied. Hitherto, no theoretical analysis or numerical simulation has been conducted to explain this phenomenon. A numerical model based on finite element method was developed to explain the experimental observations. Simulations showed that the velocity profile and ion distribution deviate significantly from a single fluid electroosmotic flow. The distortion of ion distribution near the electrical double layer is responsible for the displacement time difference for the two different flow directions. The trends obtained from simulations agree with the experimental findings. PMID:22662083

A trade-off solution between model resolution and covariance in surface-wave inversion

USGS Publications Warehouse

Xia, J.; Xu, Y.; Miller, R.D.; Zeng, C.

2010-01-01

Regularization is necessary for inversion of ill-posed geophysical problems. Appraisal of inverse models is essential for meaningful interpretation of these models. Because uncertainties are associated with regularization parameters, extra conditions are usually required to determine proper parameters for assessing inverse models. Commonly used techniques for assessment of a geophysical inverse model derived (generally iteratively) from a linear system are based on calculating the model resolution and the model covariance matrices. Because the model resolution and the model covariance matrices of the regularized solutions are controlled by the regularization parameter, direct assessment of inverse models using only the covariance matrix may provide incorrect results. To assess an inverted model, we use the concept of a trade-off between model resolution and covariance to find a proper regularization parameter with singular values calculated in the last iteration. We plot the singular values from large to small to form a singular value plot. A proper regularization parameter is normally the first singular value that approaches zero in the plot. With this regularization parameter, we obtain a trade-off solution between model resolution and model covariance in the vicinity of a regularized solution. The unit covariance matrix can then be used to calculate error bars of the inverse model at a resolution level determined by the regularization parameter. We demonstrate this approach with both synthetic and real surface-wave data. ?? 2010 Birkh??user / Springer Basel AG.

Using a Gradient Vector to Find Multiple Periodic Oscillations in Suspension Bridge Models

ERIC Educational Resources Information Center

Humphreys, L. D.; McKenna, P. J.

2005-01-01

This paper describes how the method of steepest descent can be used to find periodic solutions of differential equations. Applications to two suspension bridge models are discussed, and the method is used to find non-obvious large-amplitude solutions.

Cryopreservation of dermal fibroblasts and keratinocytes in hydroxyethyl starch-based cryoprotectants.

PubMed

Naaldijk, Yahaira; Johnson, Adiv A; Friedrich-Stöckigt, Annett; Stolzing, Alexandra

2016-12-01

Preservation of human skin fibroblasts and keratinocytes is essential for the creation of skin tissue banks. For successful cryopreservation of cells, selection of an appropriate cryoprotectant agent (CPA) is imperative. The aim of this study was to identify CPAs that minimize toxic effects and allow for the preservation of human fibroblasts and keratinocytes in suspension and in monolayers. We cryopreserved human fibroblasts and keratinocytes with different CPAs and compared them to fresh, unfrozen cells. Cells were frozen in the presence and absence of hydroxyethyl starch (HES) or dimethyl sulfoxide (DMSO), the latter of which is a commonly used CPA known to exert toxic effects on cells. Cell numbers were counted immediately post-thaw as well as three days after thawing. Cellular structures were analyzed and counted by labeling nuclei, mitochondria, and actin filaments. We found that successful cryopreservation of suspended or adherent keratinocytes can be accomplished with a 10% HES or a 5% HES, 5% DMSO solution. Cell viability of fibroblasts cryopreserved in suspension was maintained with 10% HES or 5% HES, 5% DMSO solutions. Adherent, cryopreserved fibroblasts were successfully maintained with a 5% HES, 5% DMSO solution. We conclude that skin tissue cells can be effectively cryopreserved by substituting all or a portion of DMSO with HES. Given that DMSO is the most commonly used CPA and is believed to be more toxic than HES, these findings are of clinical significance for tissue-based replacement therapies. Therapies that require the use of keratinocyte and fibroblast cells, such as those aimed at treating skin wounds or skin burns, may be optimized by substituting a portion or all of DMSO with HES during cryopreservation protocols.

Living with constipation—older people's experiences and strategies with constipation before and during hospitalization

PubMed Central

Munch, Lene; Tvistholm, Nina; Trosborg, Ingelise; Konradsen, Hanne

2016-01-01

Background Constipation is a common problem among older people. This study aimed to explore how older patients experience constipation and which strategies they used in handling the condition before and during hospitalization. Methods A qualitative exploratory research design was used. Fourteen semi-structured interviews were conducted with patients (61–91 years of age) during hospitalization. Data were analyzed by using content analysis. Results Themes concerning experiences were Bodily signs and symptoms of constipation; the participants described severe pain during constipation, as well as pronounced relief after bowel movements, Impact on well-being and social activities; being constipated negatively impacted their mood and limited social activities, Striving for bowel balance; the participants experienced an ongoing strive for balancing between constipation and diarrhea. Themes related to strategies were Struggling to find a solution; they were aware of different strategies to prevent and treat constipation, though the most common solution described was the use of laxatives, Wait and see; the participants were awaiting to take action until they experienced constipation symptoms, Constipation is a private problem being challenged during hospitalization; constipation was considered a private issue rarely discussed with health-care professionals. Conclusion This study illuminates the need for health-care professionals to be attentive to this issue and initiate the conversation with patients in order to advise on the management of constipation. PMID:27121271

Co-existence and switching between fast and Ω-slow wind solutions in rapidly rotating massive stars

NASA Astrophysics Data System (ADS)

Araya, I.; Curé, M.; ud-Doula, A.; Santillán, A.; Cidale, L.

2018-06-01

Most radiation-driven winds of massive stars can be modelled with m-CAK theory, resulting in the so-called fast solution. However, the most rapidly rotating stars among them, especially when the rotational speed is higher than {˜ } 75 per cent of the critical rotational speed, can adopt a different solution, the so-called Ω-slow solution, characterized by a dense and slow wind. Here, we study the transition region of the solutions where the fast solution changes to the Ω-slow solution. Using both time-steady and time-dependent numerical codes, we study this transition region for various equatorial models of B-type stars. In all cases, in a certain range of rotational speeds we find a region where the fast and the Ω-slow solution can co-exist. We find that the type of solution obtained in this co-existence region depends stongly on the initial conditions of our models. We also test the stability of the solutions within the co-existence region by performing base-density perturbations in the wind. We find that under certain conditions, the fast solution can switch to the Ω-slow solution, or vice versa. Such solution-switching may be a possible contributor of material injected into the circumstellar environment of Be stars, without requiring rotational speeds near critical values.

Implications of an extended dark energy cosmology with massive neutrinos for cosmological tensions

NASA Astrophysics Data System (ADS)

Poulin, Vivian; Boddy, Kimberly K.; Bird, Simeon; Kamionkowski, Marc

2018-06-01

We perform a comprehensive analysis of the most common early- and late-universe solutions to the H0 , Ly -α , and S8 discrepancies. When considered on their own, massive neutrinos provide a natural solution to the S8 discrepancy at the expense of increasing the H0 tension. If all extensions are considered simultaneously, the best-fit solution has a neutrino mass sum of ˜0.4 eV , a dark energy equation of state close to that of a cosmological constant, and no additional relativistic degrees of freedom (d.o.f). However, the H0 tension, while weakened, remains unresolved. Motivated by this result, we perform a nonparametric reconstruction of the evolution of the dark energy fluid density (allowing for negative energy densities), together with massive neutrinos. When all data sets are included, there exists a residual ˜1.9 σ tension with H0. If this residual tension remains in the future, it will indicate that it is not possible to solve the H0 tension solely with a modification of the late-universe dynamics within standard general relativity. However, we do find that it is possible to resolve the tension if either galaxy baryon acoustic oscillation (BAO) or joint light-curve analysis supernovae data are omitted. We find that negative dark energy densities are favored near redshift z ˜2.35 when including the Ly -α BAO measurement (at ˜2 σ ). This behavior may point to a negative curvature, but it is most likely indicative of systematics or at least an underestimated covariance matrix. Quite remarkably, we find that in the extended cosmologies considered in this work, the neutrino mass sum is always close to 0.4 eV regardless of the choice of external data sets, as long as the H0 tension is solved or significantly decreased.

Predictive Sampling of Rare Conformational Events in Aqueous Solution: Designing a Generalized Orthogonal Space Tempering Method.

PubMed

Lu, Chao; Li, Xubin; Wu, Dongsheng; Zheng, Lianqing; Yang, Wei

2016-01-12

In aqueous solution, solute conformational transitions are governed by intimate interplays of the fluctuations of solute-solute, solute-water, and water-water interactions. To promote molecular fluctuations to enhance sampling of essential conformational changes, a common strategy is to construct an expanded Hamiltonian through a series of Hamiltonian perturbations and thereby broaden the distribution of certain interactions of focus. Due to a lack of active sampling of configuration response to Hamiltonian transitions, it is challenging for common expanded Hamiltonian methods to robustly explore solvent mediated rare conformational events. The orthogonal space sampling (OSS) scheme, as exemplified by the orthogonal space random walk and orthogonal space tempering methods, provides a general framework for synchronous acceleration of slow configuration responses. To more effectively sample conformational transitions in aqueous solution, in this work, we devised a generalized orthogonal space tempering (gOST) algorithm. Specifically, in the Hamiltonian perturbation part, a solvent-accessible-surface-area-dependent term is introduced to implicitly perturb near-solute water-water fluctuations; more importantly in the orthogonal space response part, the generalized force order parameter is generalized as a two-dimension order parameter set, in which essential solute-solvent and solute-solute components are separately treated. The gOST algorithm is evaluated through a molecular dynamics simulation study on the explicitly solvated deca-alanine (Ala10) peptide. On the basis of a fully automated sampling protocol, the gOST simulation enabled repetitive folding and unfolding of the solvated peptide within a single continuous trajectory and allowed for detailed constructions of Ala10 folding/unfolding free energy surfaces. The gOST result reveals that solvent cooperative fluctuations play a pivotal role in Ala10 folding/unfolding transitions. In addition, our assessment analysis suggests that because essential conformational events are mainly driven by the compensating fluctuations of essential solute-solvent and solute-solute interactions, commonly employed "predictive" sampling methods are unlikely to be effective on this seemingly "simple" system. The gOST development presented in this paper illustrates how to employ the OSS scheme for physics-based sampling method designs.

Conditions for Stabilizability of Linear Switched Systems

NASA Astrophysics Data System (ADS)

Minh, Vu Trieu

2011-06-01

This paper investigates some conditions that can provide stabilizability for linear switched systems with polytopic uncertainties via their closed loop linear quadratic state feedback regulator. The closed loop switched systems can stabilize unstable open loop systems or stable open loop systems but in which there is no solution for a common Lyapunov matrix. For continuous time switched linear systems, we show that if there exists solution in an associated Riccati equation for the closed loop systems sharing one common Lyapunov matrix, the switched linear systems are stable. For the discrete time switched systems, we derive a Linear Matrix Inequality (LMI) to calculate a common Lyapunov matrix and solution for the stable closed loop feedback systems. These closed loop linear quadratic state feedback regulators guarantee the global asymptotical stability for any switched linear systems with any switching signal sequence.

A direct method of solution for the Fokas-Lenells derivative nonlinear Schrödinger equation: I. Bright soliton solutions

NASA Astrophysics Data System (ADS)

Matsuno, Yoshimasa

2012-06-01

We develop a direct method of solution for finding the bright N-soliton solution of the Fokas-Lenells derivative nonlinear Schrödinger equation. The construction of the solution is performed by means of a purely algebraic procedure using an elementary theory of determinants and does not rely on the inverse scattering transform method. We present two different expressions of the solution both of which are expressed as a ratio of determinants. We then investigate the properties of the solutions and find several new features. Specifically, we derive the formula for the phase shift caused by the collisions of bright solitons.

Comment on the Exterior Solutions and Their Geometry in Scalar-Tensor Theories of Gravity

NASA Astrophysics Data System (ADS)

Tsuchida, T.; Watanabe, K.

1999-01-01

We study series of stationary solutions with asymptotic flatness properties in the Einstein-Maxwell-free scalar system because they are locally equivalent to the exterior solutions in some class of scalar-tensor theories of gravity. First, we classify spherical exterior solutions into two types of solutions, an apparently black hole type solution and an apparently worm hole type solution. The solutions contain three parameters, and we clarify their physical significance. Second, we reduce the field equations for the axisymmetric exterior solutions. We find that the reduced equations are partially the same as the Ernst equations. As simple examples, we derive new series of static, axisymmetric exterior solutions, which correspond to Voorhees's solutions. We then establish a non-trivial relation between the spherical exterior solutions and our new solutions. Finally, since null geodesics have conformally invariant properties, we study the local geometry of the exterior solutions by using the optical scalar equations and find some anomalous behavior of the null geodesics.

Global Search Capabilities of Indirect Methods for Impulsive Transfers

NASA Astrophysics Data System (ADS)

Shen, Hong-Xin; Casalino, Lorenzo; Luo, Ya-Zhong

2015-09-01

An optimization method which combines an indirect method with homotopic approach is proposed and applied to impulsive trajectories. Minimum-fuel, multiple-impulse solutions, with either fixed or open time are obtained. The homotopic approach at hand is relatively straightforward to implement and does not require an initial guess of adjoints, unlike previous adjoints estimation methods. A multiple-revolution Lambert solver is used to find multiple starting solutions for the homotopic procedure; this approach can guarantee to obtain multiple local solutions without relying on the user's intuition, thus efficiently exploring the solution space to find the global optimum. The indirect/homotopic approach proves to be quite effective and efficient in finding optimal solutions, and outperforms the joint use of evolutionary algorithms and deterministic methods in the test cases.

Ranked solutions to a class of combinatorial optimizations—with applications in mass spectrometry based peptide sequencing and a variant of directed paths in random media

NASA Astrophysics Data System (ADS)

Doerr, Timothy P.; Alves, Gelio; Yu, Yi-Kuo

2005-08-01

Typical combinatorial optimizations are NP-hard; however, for a particular class of cost functions the corresponding combinatorial optimizations can be solved in polynomial time using the transfer matrix technique or, equivalently, the dynamic programming approach. This suggests a way to efficiently find approximate solutions-find a transformation that makes the cost function as similar as possible to that of the solvable class. After keeping many high-ranking solutions using the approximate cost function, one may then re-assess these solutions with the full cost function to find the best approximate solution. Under this approach, it is important to be able to assess the quality of the solutions obtained, e.g., by finding the true ranking of the kth best approximate solution when all possible solutions are considered exhaustively. To tackle this statistical issue, we provide a systematic method starting with a scaling function generated from the finite number of high-ranking solutions followed by a convergent iterative mapping. This method, useful in a variant of the directed paths in random media problem proposed here, can also provide a statistical significance assessment for one of the most important proteomic tasks-peptide sequencing using tandem mass spectrometry data. For directed paths in random media, the scaling function depends on the particular realization of randomness; in the mass spectrometry case, the scaling function is spectrum-specific.

Simulation of macromolecule self-assembly in solution: A multiscale approach

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

Lavino, Alessio D., E-mail: alessiodomenico.lavino@studenti.polito.it; Barresi, Antonello A., E-mail: antonello.barresi@polito.it; Marchisio, Daniele L., E-mail: daniele.marchisio@polito.it

2015-12-17

One of the most common processes to produce polymer nanoparticles is to induce self-assembly by using the solvent-displacement method, in which the polymer is dissolved in a “good” solvent and the solution is then mixed with an “anti-solvent”. The polymer ability to self-assemble in solution is therefore determined by its structural and transport properties in solutions of the pure solvents and at the intermediate compositions. In this work, we focus on poly-ε-caprolactone (PCL) which is a biocompatible polymer that finds widespread application in the pharmaceutical and biomedical fields, performing simulation at three different scales using three different computational tools: fullmore » atomistic molecular dynamics (MD), population balance modeling (PBM) and computational fluid dynamics (CFD). Simulations consider PCL chains of different molecular weight in solution of pure acetone (good solvent), of pure water (anti-solvent) and their mixtures, and mixing at different rates and initial concentrations in a confined impinging jets mixer (CIJM). Our MD simulations reveal that the nano-structuring of one of the solvents in the mixture leads to an unexpected identical polymer structure irrespectively of the concentration of the two solvents. In particular, although in pure solvents the behavior of the polymer is, as expected, very different, at intermediate compositions, the PCL chain shows properties very similar to those found in pure acetone as a result of the clustering of the acetone molecules in the vicinity of the polymer chain. We derive an analytical expression to predict the polymer structural properties in solution at different solvent compositions and use it to formulate an aggregation kernel to describe the self-assembly in the CIJM via PBM and CFD. Simulations are eventually validated against experiments.« less

Common Neurogenetic Diagnosis and Meso-Limbic Manipulation of Hypodopaminergic Function in Reward Deficiency Syndrome (RDS): Changing the Recovery Landscape

PubMed Central

Blum, Kenneth; Febo, Marcelo; Badgaiyan, Rajendra D.; Demetrovics, Zsolt; Simpatico, Thomas; Fahlke, Claudia; Li, Mona; Dushaj, Kristina; Gold, Mark S.

2017-01-01

Abstract: Background: In 1990, Blum and associates provided the first confirmed genetic link between the DRD2 polymorphisms and alcoholism. This finding was based on an earlier conceptual framework, which served as a blueprint for their seminal genetic association discovery they termed “Brain Reward Cascade.” These findings were followed by a new way of understanding all addictive behaviors (substance and non-substance) termed “Reward Deficiency Syndrome” (RDS). RDS incorporates a complex multifaceted array of inheritable behaviors that are polygenic. Objective: In this review article, we attempt to clarify these terms and provide a working model to accurately diagnose and treat these unwanted behaviors. Method: We are hereby proposing the development of a translational model we term “Reward Deficiency Solution System™” that incorporates neurogenetic testing and meso-limbic manipulation of a “hypodopaminergic” trait/state, which provides dopamine agonistic therapy (DAT) as well as reduced “dopamine resistance,” while embracing “dopamine homeostasis.” Result: The result is better recovery and relapse prevention, despite DNA antecedents, which could impact the recovery process and relapse. Understanding the commonality of mental illness will transform erroneous labeling based on symptomatology, into a genetic and anatomical etiology. WC: 184. PMID:27174576

A combinatorial approach to the design of vaccines.

PubMed

Martínez, Luis; Milanič, Martin; Legarreta, Leire; Medvedev, Paul; Malaina, Iker; de la Fuente, Ildefonso M

2015-05-01

We present two new problems of combinatorial optimization and discuss their applications to the computational design of vaccines. In the shortest λ-superstring problem, given a family S1,...,S(k) of strings over a finite alphabet, a set Τ of "target" strings over that alphabet, and an integer λ, the task is to find a string of minimum length containing, for each i, at least λ target strings as substrings of S(i). In the shortest λ-cover superstring problem, given a collection X1,...,X(n) of finite sets of strings over a finite alphabet and an integer λ, the task is to find a string of minimum length containing, for each i, at least λ elements of X(i) as substrings. The two problems are polynomially equivalent, and the shortest λ-cover superstring problem is a common generalization of two well known combinatorial optimization problems, the shortest common superstring problem and the set cover problem. We present two approaches to obtain exact or approximate solutions to the shortest λ-superstring and λ-cover superstring problems: one based on integer programming, and a hill-climbing algorithm. An application is given to the computational design of vaccines and the algorithms are applied to experimental data taken from patients infected by H5N1 and HIV-1.

Solute clearance measurement in the assessment of dialysis adequacy among African continuous ambulatory peritoneal dialysis patients.

PubMed

Abdu, Aliyu; Naidoo, Sagren; Malgas, Shirin; Naicker, Jocelyn T; Paget, Graham; Naicker, Saraladevi

2015-01-01

Solute clearance measurement is an objective means of quantifying the dose of peritoneal dialysis (PD). Despite continued debate on the interpretation and precise prognostic value of small solute clearance in PD patients, guidelines based on solute clearance values are common in clinical practice. There is limited information on the solute clearance indices and PD adequacy parameters among this predominantly low socioeconomic status PD population. We investigated the solute clearance among continuous ambulatory peritoneal dialysis (CAPD) patients at the Charlotte Maxeke Johannesburg Academic Hospital and its relationship with other parameters of PD adequacy. Seventy patients on CAPD were studied in this cross-sectional study. Solute clearance was assessed using urea clearance (Kt/V). Linear regression analysis was used to determine factors associated with solute clearance, while analysis of variance was used to test the influence of weekly Kt/V on blood pressure (BP), hemoglobin (Hb) and other biochemical parameters. The mean age of the study population was 37.9 ± 12.4 years, 43% were females and 86% were black Africans. The mean duration on CAPD was 19.7 ± 20.8 months. Mean systolic and diastolic BP were 144 ± 28 and 92 ± 17 mm Hg, respectively. The mean Hb was 11.1 ± 2.2 g/dL and the mean weekly Kt/V was 1.7 ± 0.3. Factors like systolic BP, Hb level, serum levels of cholesterol, calcium, phosphate, parathyroid hormone and albumin were not significantly associated with the weekly Kt/V. We conclude that the dose of PD received by the majority of our patients in terms of the weekly Kt/V is within the recommended values and that this finding is significant considering the low socioeconomic background of our patients. There is no significant association between Kt/V and other indices of dialysis adequacy.

An efficient and practical approach to obtain a better optimum solution for structural optimization

NASA Astrophysics Data System (ADS)

Chen, Ting-Yu; Huang, Jyun-Hao

2013-08-01

For many structural optimization problems, it is hard or even impossible to find the global optimum solution owing to unaffordable computational cost. An alternative and practical way of thinking is thus proposed in this research to obtain an optimum design which may not be global but is better than most local optimum solutions that can be found by gradient-based search methods. The way to reach this goal is to find a smaller search space for gradient-based search methods. It is found in this research that data mining can accomplish this goal easily. The activities of classification, association and clustering in data mining are employed to reduce the original design space. For unconstrained optimization problems, the data mining activities are used to find a smaller search region which contains the global or better local solutions. For constrained optimization problems, it is used to find the feasible region or the feasible region with better objective values. Numerical examples show that the optimum solutions found in the reduced design space by sequential quadratic programming (SQP) are indeed much better than those found by SQP in the original design space. The optimum solutions found in a reduced space by SQP sometimes are even better than the solution found using a hybrid global search method with approximate structural analyses.

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

Tadayyon, Ghazal; Mazinani, Mohammad; Guo, Yina

Martensitic evolution in Ti-rich NiTi alloy, Ti50.5Ni49.5, has been investigated as a function of annealing, solution treatment and a combination thereof and a detailed electron microscopic investigation carried out. Self-accommodated martensite plates resulted in all heat treated samples. Martensitic < 011 > type II twins, which are common in NiTi shape memory alloys, was found in both as-received and heat-treated samples. Solution treated samples, additionally, showed {11-1} type I twinning was also found in samples that have been annealed after solution-treatment. Another common feature of the microstructure in both as-received and heat treated samples is the formation of Ti{sub 2}Nimore » precipitates. The size, number and dispersions of these precipitates can be controlled by resorting to a suitable heat treatment e.g. solution treatment.« less

The most common problem facing by the maintenance department: A case Study between Universiti Tun Hussein Onn Malaysia (UTHM) and Universiti Teknologi Malaysia (UTM)

NASA Astrophysics Data System (ADS)

Norazam Yasin, Mohd; Mohamad Zin, Rosli; Halid Abdullah, Abd; Shafiq Mahmad, Muhammad; Fikri Hasmori, Muhammad

2017-11-01

From time to time, the maintenance works become more challenging due to construction of new building and also aging of the existing buildings. University buildings without any exception require proper maintenance services to support their function requirements and this can be considered as major responsibilities to be fulfilled by the maintenance department in the universities. Maintenance department specifically will face various kinds of problems in their operation works and thus this might influence the maintenance work operations itself. This study purposely to identify the common problem facing by the maintenance department and also to examine the current status of the maintenance department. In addition, this study would also propose any suitable approach that could be implemented to overcome the problem facing by the maintenance department. To achieve the objectives of this study, a combination of deep literature study and carrying out a survey is necessary. Literature study aimed to obtain deeper information about this study, meanwhile a survey aimed at identifying the common problem facing by the maintenance department and also to provide the information of the maintenance department’s organization. Several methods will be used in analyzing the data obtained through the survey, including Microsoft Office Excel and also using mean index formula. This study has identified three categories of problem in the maintenance department, which are management problems, human resource problem, and technical problems. Following the findings, several solutions being proposed which can be implemented as the solution to the problem facing. These suggestions have the potential to improve the maintenance department work efficiency, thus could help to increase the department productivity.

Unwanted pregnancy and induced abortion among young women 16-22 years old in Greece: a retrospective study of the risk factors.

PubMed

Salakos, N; Koumousidis, A; Bakalianou, K; Paltoglou, G; Kalampokas, T; Iavazzo, C

2010-01-01

Unwanted pregnancies and the subsequent induced abortions are common problems of our youths in modern Greece. The aim of this study was to recognize the risk factors of the problem in an effort to find the best possible solution out of this social dead end. We interviewed 1,320 young female individuals and analyzed their answers using statistical analysis. Several useful conclusions were reached concerning the forces that are involved in unwanted pregnancy/induced abortions. We have tried to underline the strategy to combat the problem. Sexual education and the proper use of contraception remain the essential tools in this effort.

A short review on thermosonic flip chip bonding

NASA Astrophysics Data System (ADS)

Suppiah, Sarveshvaran; Ong, Nestor Rubio; Sauli, Zaliman; Sarukunaselan, Karunavani; Alcain, Jesselyn Barro; Shahimin, Mukhzeer Mohamad; Retnasamy, Vithyacharan

2017-09-01

This review is to study the evolution and key findings, critical technical challenges, solutions and bonding equipment of thermosonic flip chip bonding. Based on the review done, it was found that ultrasonic power, bonding time and force are the three main critical parameters need to be optimized in order to achieve sound and reliable bonding between the die and substrate. A close monitoring of the ultrasonic power helped to prevent over bonding phenomena on flexible substrate. Gold stud bumping is commonly used in thermosonic bonding compared to solder due to its better reliability obtained in the LED and optoelectronic packages. The review comprised short details on the available thermosonic bonding equipment in the semiconductor industry as well.

A new way to protect privacy in large-scale genome-wide association studies.

PubMed

Kamm, Liina; Bogdanov, Dan; Laur, Sven; Vilo, Jaak

2013-04-01

Increased availability of various genotyping techniques has initiated a race for finding genetic markers that can be used in diagnostics and personalized medicine. Although many genetic risk factors are known, key causes of common diseases with complex heritage patterns are still unknown. Identification of such complex traits requires a targeted study over a large collection of data. Ideally, such studies bring together data from many biobanks. However, data aggregation on such a large scale raises many privacy issues. We show how to conduct such studies without violating privacy of individual donors and without leaking the data to third parties. The presented solution has provable security guarantees. Supplementary data are available at Bioinformatics online.

Efficacy of brief telephone psychotherapy with callers to a suicide hotline.

PubMed

Rhee, Wayne K; Merbaum, Michael; Strube, Michael J; Self, Susan M

2005-06-01

The efficacy of two types of theapy conducted exclusively over the telephone was studied. Clients (N=55) were recruited from a pool of callers to a suicide hotline and were randomly assigned to a waiting list control (WC) or Solution Focused Brief Therapy (SFBT) or Common Factors Therapy (CFT). It was hypothesized that improvements would be significantly higher in the two therapy conditions compared to the waitlist control and SFBT would be significantly more efficacious than CFT. Results confirmed that improvement was significantly higher in the two treatment conditions compared to the waitlist control, but no difference in improvement was found between SFBT and CFT. The implications of these findings for suicide hotlines are discussed.

The global forum on environment and development

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

Not Available

1990-01-01

The first Global Conference of Spiritual and Parliamentary Leaders on Human Survival was held in Oxford, England not to discuss world issues, but to test the ability of 100 spiritual leaders and 100 parliamentarians to work together in a world which has preferred to separate church and state. This conference, held in Moscow, attracted more than 1,000 people. The main purpose was to find common solutions to environmental quality, economic development, and human survival as citizens of planet Earth. Notable addresses were heard from Javier Perez de Cuellar, Senator Albert Gore, Carl Sagan, Lester Brown, Nafis Sadik, Evguenij Velikhov, andmore » Mikhail Gorbachev who advocated an International Green Cross.« less

Effectiveness of participatory planning for community management of fisheries in Bangladesh.

PubMed

Sultana, Parvin; Abeyasekera, Savitri

2008-01-01

This study provides statistical evidence that support for community-based management of resources was more effective when initiated through a process known as participatory action plan development (PAPD). Thirty-six sites were studied where community management of fisheries was facilitated by NGOs. All involved community participation and establishing local fisheries management institutions. However, communities were able to take up more conservation-related interventions and faced fewer conflicts in the 18 sites where a PAPD was the basis for collective action and institution development. This indicates the value and effectiveness of adopting good practice in participatory planning, such as PAPD, which helps diverse stakeholders find common problems and solutions for natural resource management.

Unusual Root Canal Irrigation Solutions.

PubMed

Mohammadi, Zahed; Jafarzadeh, Hamid; Shalavi, Sousan; Kinoshita, Jun-Ichiro

2017-05-01

Microorganisms and their by-products play a critical role in pulp and periradicular pathosis. Therefore, one of the main purposes of root canal treatment is disinfection of the entire system of the canal. This aim may be obtained using mechanical preparation, chemical irrigation, and temporary medication of the canal. For this purpose, various irrigation solutions have been advocated. Common root canal irrigants, such as sodium hypochlorite, chlorhexidine, and a mixture of tetracycline, acid, and detergent have been extensively reviewed. The aim of this review was to address the less common newer root canal irrigation solutions, such as citric acid, maleic acid, electrochemically activated water, green tea, ozonated water, and SmearClear.

A Game Theoretic Framework for Analyzing Re-Identification Risk

PubMed Central

Wan, Zhiyu; Vorobeychik, Yevgeniy; Xia, Weiyi; Clayton, Ellen Wright; Kantarcioglu, Murat; Ganta, Ranjit; Heatherly, Raymond; Malin, Bradley A.

2015-01-01

Given the potential wealth of insights in personal data the big databases can provide, many organizations aim to share data while protecting privacy by sharing de-identified data, but are concerned because various demonstrations show such data can be re-identified. Yet these investigations focus on how attacks can be perpetrated, not the likelihood they will be realized. This paper introduces a game theoretic framework that enables a publisher to balance re-identification risk with the value of sharing data, leveraging a natural assumption that a recipient only attempts re-identification if its potential gains outweigh the costs. We apply the framework to a real case study, where the value of the data to the publisher is the actual grant funding dollar amounts from a national sponsor and the re-identification gain of the recipient is the fine paid to a regulator for violation of federal privacy rules. There are three notable findings: 1) it is possible to achieve zero risk, in that the recipient never gains from re-identification, while sharing almost as much data as the optimal solution that allows for a small amount of risk; 2) the zero-risk solution enables sharing much more data than a commonly invoked de-identification policy of the U.S. Health Insurance Portability and Accountability Act (HIPAA); and 3) a sensitivity analysis demonstrates these findings are robust to order-of-magnitude changes in player losses and gains. In combination, these findings provide support that such a framework can enable pragmatic policy decisions about de-identified data sharing. PMID:25807380

Geometrical Solutions of Some Quadratic Equations with Non-Real Roots

ERIC Educational Resources Information Center

Pathak, H. K.; Grewal, A. S.

2002-01-01

This note gives geometrical/graphical methods of finding solutions of the quadratic equation ax[squared] + bx + c = 0, a [not equal to] 0, with non-real roots. Three different cases which give rise to non-real roots of the quadratic equation have been discussed. In case I a geometrical construction and its proof for finding the solutions of the…

Self-consistent large- N analytical solutions of inhomogeneous condensates in quantum ℂP N - 1 model

NASA Astrophysics Data System (ADS)

Nitta, Muneto; Yoshii, Ryosuke

2017-12-01

We give, for the first time, self-consistent large- N analytical solutions of inhomogeneous condensates in the quantum ℂP N - 1 model in the large- N limit. We find a map from a set of gap equations of the ℂP N - 1 model to those of the Gross-Neveu (GN) model (or the gap equation and the Bogoliubov-de Gennes equation), which enables us to find the self-consistent solutions. We find that the Higgs field of the ℂP N - 1 model is given as a zero mode of solutions of the GN model, and consequently only topologically non-trivial solutions of the GN model yield nontrivial solutions of the ℂP N - 1 model. A stable single soliton is constructed from an anti-kink of the GN model and has a broken (Higgs) phase inside its core, in which ℂP N - 1 modes are localized, with a symmetric (confining) phase outside. We further find a stable periodic soliton lattice constructed from a real kink crystal in the GN model, while the Ablowitz-Kaup-Newell-Segur hierarchy yields multiple solitons at arbitrary separations.

Measurement equivalence: a glossary for comparative population health research.

PubMed

Morris, Katherine Ann

2018-03-06

Comparative population health studies are becoming more common and are advancing solutions to crucial public health problems, but decades-old measurement equivalence issues remain without a common vocabulary to identify and address the biases that contribute to non-equivalence. This glossary defines sources of measurement non-equivalence. While drawing examples from both within-country and between-country studies, this glossary also defines methods of harmonisation and elucidates the unique opportunities in addition to the unique challenges of particular harmonisation methods. Its primary objective is to enable population health researchers to more clearly articulate their measurement assumptions and the implications of their findings for policy. It is also intended to provide scholars and policymakers across multiple areas of inquiry with tools to evaluate comparative research and thus contribute to urgent debates on how to ameliorate growing health disparities within and between countries. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

The Correlates of Similarity Estimates are Often Misleadingly Positive: The Nature and Scope of the Problem, and Some Solutions

PubMed Central

Wood, Dustin; Furr, R. Michael

2015-01-01

Research on similarity constructs (e.g., dyadic similarity, personality stability; judgment agreement and accuracy) frequently find them to be associated with positive outcomes. However, a methodological pitfall associated with common ‘overall similarity’ indices, which we term the normative-desirability confound (NDC), will regularly result in similarity constructs apparently having more positive effects than they do in reality. In essence, when an individual is estimated to be similar to another person by common indices, this will strongly indicate that the individual has desirable characteristics. Consequently, the correlates of overall similarity indices can often be interpreted as indicating the beneficial effects of having desirable characteristics, without needing to attribute any additional salutary effect to similarity. We show that this confound is present in overall similarity estimates for a wide range of constructs (e.g., personality traits, attitudes, emotions, behaviors, values), how it can be accounted for, and discuss larger implications for our understanding of similarity constructs. PMID:25896284

Code of Ethics in a Multicultural Company and its Legal Context

NASA Astrophysics Data System (ADS)

Odlerová, Eva; Ďurišová, Jaroslava; Šramel, Bystrík

2012-12-01

The entry of foreign investors and simultaneous expansion of different national cultures, religions, rules, moral and ethical standards is bringing up problems of cooperation and coexistence of different nationalities, ethnicities and cultures. Working in an international environment therefore requires adaptation to a variety of economic, political, legal, technical, social, cultural and historical conditions. One possible solution is to define a code of ethics, guidelines which find enough common moral principles, which can become the basis for the adoption of general ethical standards, while respecting national, cultural differences and practices. In this article, the authors pay attention not only to the analysis of the common ethical rules in a multicultural company, but also to the legal aspects of codes of ethics. Each code of ethics is a set of standards, which, like the legal norms, regulate the behaviour of individuals. These standards, however, must simultaneously meet certain statutory criteria that define the boundaries of regulation of employee’s behaviour.

On the stability of non-supersymmetric supergravity solutions

NASA Astrophysics Data System (ADS)

Imaanpur, Ali; Zameni, Razieh

2017-09-01

We examine the stability of some non-supersymmetric supergravity solutions that have been found recently. The first solution is AdS5 ×M6, for M6 an stretched CP3. We consider breathing and squashing mode deformations of the metric, and find that the solution is stable against small fluctuations of this kind. Next we consider type IIB solution of AdS2 ×M8, where the compact space is a U (1) bundle over N (1 , 1). We study its stability under the deformation of M8 and the 5-form flux. In this case we also find that the solution is stable under small fluctuation modes of the corresponding deformations.

Traveling wave and exact solutions for the perturbed nonlinear Schrödinger equation with Kerr law nonlinearity

NASA Astrophysics Data System (ADS)

Akram, Ghazala; Mahak, Nadia

2018-06-01

The nonlinear Schrödinger equation (NLSE) with the aid of three order dispersion terms is investigated to find the exact solutions via the extended (G'/G2)-expansion method and the first integral method. Many exact traveling wave solutions, such as trigonometric, hyperbolic, rational, soliton and complex function solutions, are characterized with some free parameters of the problem studied. It is corroborated that the proposed techniques are manageable, straightforward and powerful tools to find the exact solutions of nonlinear partial differential equations (PDEs). Some figures are plotted to describe the propagation of traveling wave solutions expressed by the hyperbolic functions, trigonometric functions and rational functions.

Analytical solution for the normal emission portion of the averaged Yarkovsky-O'Keefe-Radzvieskii-Paddack coefficient for a single facet

NASA Astrophysics Data System (ADS)

Albuja, Antonella A.; Scheeres, Daniel J.

2015-02-01

The Yarkovsky-O'Keefe-Radzvieskii-Paddack (YORP) effect has been well studied for asteroids. This paper develops an analytic solution to find the normal emission YORP component for a single facet. The solution presented here does not account for self-shadowing or self-heating. The YORP coefficient for all facets can be summed together to find the total coefficient of the asteroid. The normal emission component of YORP has been shown to be the most important for asteroids and it directly affects the rate of change of the asteroid's spin period. The analytical solution found is a sole function of the facet's geometry and the obliquity of the asteroid. This solution is universal for any facet and its orientation. The behaviour of the coefficient is analysed with this analytical solution. The closed-form solution is used to find the total YORP coefficient for the asteroids Apollo and 1998 ML14 whose shape models are composed of different numbers of facets. The results are then compared to published results and those obtained through numerical quadrature for validation.

Revisiting the two formulations of Bianchi identities and their implications on moduli stabilization

NASA Astrophysics Data System (ADS)

Shukla, Pramod

2016-08-01

In the context of non-geometric type II orientifold compactifications, there have been two formulations for representing the various NS-NS Bianchi-identities. In the first formulation, the standard three-form flux ( H 3), the geometric flux ( ω) and the non-geometric fluxes ( Q and R) are expressed by using the real six-dimensional indices (e.g. {H}_{ijk}, {ω_{ij}}^k, {Q_i}{_{jk}} and R ijk ), and this formulation has been heavily utilized for simplifying the scalar potentials in toroidal-orientifolds. On the other hand, relevant for the studies beyond toroidal backgrounds, a second formulation is utilized in which all flux components are written in terms of various involutively even/odd (2 , 1)- and (1 , 1)-cohomologies of the complex threefold. In the lights of recent model building interests and some observations made in [1, 2], in this article, we revisit two most commonly studied toroidal examples in detail to illustrate that the present forms of these two formulations are not completely equivalent. To demonstrate the same, we translate all the identities of the first formulation into cohomology ingredients, and after a tedious reshuffling of the subsequent constraints, interestingly we find that all the identities of the second formulation are embedded into the first formulation which has some additional constraints. In addition, we look for the possible solutions of these Bianchi identities in a detailed analysis, and we find that some solutions can reduce the size of scalar potential very significantly, and in some cases are too strong to break the no-scale structure completely. Finally, we also comment on the influence of imposing some of the solutions of Bianchi identities in studying moduli stabilization.

Protein denaturants at aqueous-hydrophobic interfaces: self-consistent correlation between induced interfacial fluctuations and denaturant stability at the interface.

PubMed

Cui, Di; Ou, Shu-Ching; Patel, Sandeep

2015-01-08

The notion of direct interaction between denaturing cosolvent and protein residues has been proposed in dialogue relevant to molecular mechanisms of protein denaturation. Here we consider the correlation between free energetic stability and induced fluctuations of an aqueous-hydrophobic interface between a model hydrophobically associating protein, HFBII, and two common protein denaturants, guanidinium cation (Gdm(+)) and urea. We compute potentials of mean force along an order parameter that brings the solute molecule close to the known hydrophobic region of the protein. We assess potentials of mean force for different relative orientations between the protein and denaturant molecule. We find that in both cases of guanidinium cation and urea relative orientations of the denaturant molecule that are parallel to the local protein-water interface exhibit greater stability compared to edge-on or perpendicular orientations. This behavior has been observed for guanidinium/methylguanidinium cations at the liquid-vapor interface of water, and thus the present results further corroborate earlier findings. Further analysis of the induced fluctuations of the aqueous-hydrophobic interface upon approach of the denaturant molecule indicates that the parallel orientation, displaying a greater stability at the interface, also induces larger fluctuations of the interface compared to the perpendicular orientations. The correlation of interfacial stability and induced interface fluctuation is a recurring theme for interface-stable solutes at hydrophobic interfaces. Moreover, observed correlations between interface stability and induced fluctuations recapitulate connections to local hydration structure and patterns around solutes as evidenced by experiment (Cooper et al., J. Phys. Chem. A 2014, 118, 5657.) and high-level ab initio/DFT calculations (Baer et al., Faraday Discuss 2013, 160, 89).

Protein Denaturants at Aqueous–Hydrophobic Interfaces: Self-Consistent Correlation between Induced Interfacial Fluctuations and Denaturant Stability at the Interface

PubMed Central

2015-01-01

The notion of direct interaction between denaturing cosolvent and protein residues has been proposed in dialogue relevant to molecular mechanisms of protein denaturation. Here we consider the correlation between free energetic stability and induced fluctuations of an aqueous–hydrophobic interface between a model hydrophobically associating protein, HFBII, and two common protein denaturants, guanidinium cation (Gdm+) and urea. We compute potentials of mean force along an order parameter that brings the solute molecule close to the known hydrophobic region of the protein. We assess potentials of mean force for different relative orientations between the protein and denaturant molecule. We find that in both cases of guanidinium cation and urea relative orientations of the denaturant molecule that are parallel to the local protein–water interface exhibit greater stability compared to edge-on or perpendicular orientations. This behavior has been observed for guanidinium/methylguanidinium cations at the liquid–vapor interface of water, and thus the present results further corroborate earlier findings. Further analysis of the induced fluctuations of the aqueous–hydrophobic interface upon approach of the denaturant molecule indicates that the parallel orientation, displaying a greater stability at the interface, also induces larger fluctuations of the interface compared to the perpendicular orientations. The correlation of interfacial stability and induced interface fluctuation is a recurring theme for interface-stable solutes at hydrophobic interfaces. Moreover, observed correlations between interface stability and induced fluctuations recapitulate connections to local hydration structure and patterns around solutes as evidenced by experiment (Cooper et al., J. Phys. Chem. A2014, 118, 5657.) and high-level ab initio/DFT calculations (Baer et al., Faraday Discuss2013, 160, 89). PMID:25536388

Combining energy and Laplacian regularization to accurately retrieve the depth of brain activity of diffuse optical tomographic data

NASA Astrophysics Data System (ADS)

Chiarelli, Antonio M.; Maclin, Edward L.; Low, Kathy A.; Mathewson, Kyle E.; Fabiani, Monica; Gratton, Gabriele

2016-03-01

Diffuse optical tomography (DOT) provides data about brain function using surface recordings. Despite recent advancements, an unbiased method for estimating the depth of absorption changes and for providing an accurate three-dimensional (3-D) reconstruction remains elusive. DOT involves solving an ill-posed inverse problem, requiring additional criteria for finding unique solutions. The most commonly used criterion is energy minimization (energy constraint). However, as measurements are taken from only one side of the medium (the scalp) and sensitivity is greater at shallow depths, the energy constraint leads to solutions that tend to be small and superficial. To correct for this bias, we combine the energy constraint with another criterion, minimization of spatial derivatives (Laplacian constraint, also used in low resolution electromagnetic tomography, LORETA). Used in isolation, the Laplacian constraint leads to solutions that tend to be large and deep. Using simulated, phantom, and actual brain activation data, we show that combining these two criteria results in accurate (error <2 mm) absorption depth estimates, while maintaining a two-point spatial resolution of <24 mm up to a depth of 30 mm. This indicates that accurate 3-D reconstruction of brain activity up to 30 mm from the scalp can be obtained with DOT.

Direct numerical simulation of particulate flows with an overset grid method

NASA Astrophysics Data System (ADS)

Koblitz, A. R.; Lovett, S.; Nikiforakis, N.; Henshaw, W. D.

2017-08-01

We evaluate an efficient overset grid method for two-dimensional and three-dimensional particulate flows for small numbers of particles at finite Reynolds number. The rigid particles are discretised using moving overset grids overlaid on a Cartesian background grid. This allows for strongly-enforced boundary conditions and local grid refinement at particle surfaces, thereby accurately capturing the viscous boundary layer at modest computational cost. The incompressible Navier-Stokes equations are solved with a fractional-step scheme which is second-order-accurate in space and time, while the fluid-solid coupling is achieved with a partitioned approach including multiple sub-iterations to increase stability for light, rigid bodies. Through a series of benchmark studies we demonstrate the accuracy and efficiency of this approach compared to other boundary conformal and static grid methods in the literature. In particular, we find that fully resolving boundary layers at particle surfaces is crucial to obtain accurate solutions to many common test cases. With our approach we are able to compute accurate solutions using as little as one third the number of grid points as uniform grid computations in the literature. A detailed convergence study shows a 13-fold decrease in CPU time over a uniform grid test case whilst maintaining comparable solution accuracy.

Optimal simultaneous superpositioning of multiple structures with missing data.

PubMed

Theobald, Douglas L; Steindel, Phillip A

2012-08-01

Superpositioning is an essential technique in structural biology that facilitates the comparison and analysis of conformational differences among topologically similar structures. Performing a superposition requires a one-to-one correspondence, or alignment, of the point sets in the different structures. However, in practice, some points are usually 'missing' from several structures, for example, when the alignment contains gaps. Current superposition methods deal with missing data simply by superpositioning a subset of points that are shared among all the structures. This practice is inefficient, as it ignores important data, and it fails to satisfy the common least-squares criterion. In the extreme, disregarding missing positions prohibits the calculation of a superposition altogether. Here, we present a general solution for determining an optimal superposition when some of the data are missing. We use the expectation-maximization algorithm, a classic statistical technique for dealing with incomplete data, to find both maximum-likelihood solutions and the optimal least-squares solution as a special case. The methods presented here are implemented in THESEUS 2.0, a program for superpositioning macromolecular structures. ANSI C source code and selected compiled binaries for various computing platforms are freely available under the GNU open source license from http://www.theseus3d.org. dtheobald@brandeis.edu Supplementary data are available at Bioinformatics online.

Effects of Detergent β-Octylglucoside and Phosphate Salt Solutions on Phase Behavior of Monoolein Mesophases

PubMed Central

Khvostichenko, Daria S.; Ng, Johnathan J.D.; Perry, Sarah L.; Menon, Monisha; Kenis, Paul J.A.

2013-01-01

Using small-angle x-ray scattering (SAXS), we investigated the phase behavior of mesophases of monoolein (MO) mixed with additives commonly used for the crystallization of membrane proteins from lipidic mesophases. In particular, we examined the effect of sodium and potassium phosphate salts and the detergent β-octylglucoside (βOG) over a wide range of compositions relevant for the crystallization of membrane proteins in lipidic mesophases. We studied two types of systems: 1), ternary mixtures of MO with salt solutions above the hydration boundary; and 2), quaternary mixtures of MO with βOG and salt solutions over a wide range of hydration conditions. All quaternary mixtures showed highly regular lyotropic phase behavior with the same sequence of phases (Lα, Ia3d, and Pn3m) as MO/water mixtures at similar temperatures. The effects of additives in quaternary systems agreed qualitatively with those found in ternary mixtures in which only one additive is present. However, quantitative differences in the effects of additives on the lattice parameters of fully hydrated mesophases were found between ternary and quaternary mixtures. We discuss the implications of these findings for mechanistic investigations of membrane protein crystallization in lipidic mesophases and for studies of the suitability of precipitants for mesophase-based crystallization methods. PMID:24138861

Use of fentanyl and midazolam in mechanically ventilated children--Does the method of infusion matter?

PubMed

da Silva, Paulo Sérgio Lucas; Reis, Maria Eunice; de Aguiar, Vânia Euzébio; Fonseca, Marcelo Cunio Machado

2016-04-01

Benzodiazepines and opioids are commonly used in pediatric intensive care unit. However, there is no previous study assessing the use of administering these drugs combined (single solution) or separately. We sought to evaluate the impact of these 2 different methods of providing sedation/analgesia in pediatric intensive care unit. One hundred twelve patients mechanically ventilated for more than 48 hours were randomized to receive a protocolized sedation regime comprising midazolam and fentanyl either separately (group 1, 57 patients) or combined as a single solution (group 2, 55 patients). Primary end point variable was the cumulated dose of midazolam and fentanyl. The median cumulated doses of both fentanyl (0.19 vs 0.37 mg/kg, P < .05) and midazolam (28.8 vs 45.6 mg/kg, P < .05) required in group 2 were higher when compared with those of group 1. Moreover, group 2 patients had a significantly longer time of vasopressor drugs requirement and a higher number of patients developing tolerance. Patients who received a single solution of midazolam and fentanyl had a higher cumulated dose of compared with those patients who did not. The potential risk for long-term neurologic effects on developing brains associated with this finding should be considered. Copyright © 2015 Elsevier Inc. All rights reserved.

Ultrafast dynamics and Raman imaging of metal complexes of tetrasulphonated phthalocyanines in human cancerous and noncancerous breast tissues

NASA Astrophysics Data System (ADS)

Abramczyk, H.; Jarota, A.; Brozek-Pluska, B.; Tondusson, M.; Freysz, E.; Musial, J.; Kordek, R.

2013-03-01

A promising material in medicine, electronics, optoelectronics, electrochemistry, catalysis and photophysics, Al(III) phthalocyanine chloride tetrasulfonic acid (AlPcS4) is investigated at biological interfaces of human breast tissue by means of time-resolved spectroscopy. The nature of fast processes and pathways of the competing relaxation mechanisms from the initially excited electronic states of a photosensitizer at biological interfaces have been studied. Comparison between the results in the biological environment of the breast tissues and in aqueous solutions demonstrates that the photochemical mechanisms become dramatically different. The presented results provide a basis for a substantial revision of the commonly accepted assumption that photochemistry of the bulk properties of photosensitizers in solutions can be translated to the interfacial region. First, in solution the dynamics of the photosensitizer is much slower than that at the biological interface. Second, the dynamics of the photosensitizer in the cancerous tissue is dramatically slower than that in noncancerous tissue. Our results provide evidence that molecular structures responsible for harvesting of the light energy in biological tissue find their ways for a recovery through some special features of the potential energy surfaces such as conical intersections, which facilitate the rate of radiationless transitions and maintain the photostability in the biological systems.

Experimental investigation of heat transfer characteristics of guar-based polymer solutions and gels

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

Azouz, I.; Vinod, P.S.; Shah, S.N.

1996-12-31

An experimental investigation of the heat transfer characteristics of hydraulic fracturing fluids was conducted at the Fracturing Fluid Characterization Facility (FFCF) of the University of Oklahoma. The facility is equipped with a high pressure fracture simulator, coiled tubing fluid pre-conditioning system, and a full-scale, counter-current, double pipe heat exchanger. The fluids investigated include non-crosslinked and borate-crosslinked guar gum and hydroxypropyl guar (HPG). Results were also obtained for water and were used as a basis for comparison. The effects of flow rate, operating temperature, pH, and various levels of shear pre-conditioning, on the heat transfer behavior of the test fluids weremore » investigated. Results show a significant difference between the heat transfer coefficient of the pure solvent (water) and those of the polymer solutions tested. While all polymer solutions tested exhibited lower heat transfer coefficients than that of the pure solvent, crosslinking appears to enhance the heat transfer characteristics of the polymer fluids. It was also observed that shear preconditioning does not seem to have a significant effect on the heat transfer coefficient of the crosslinked gels. These findings are of great interest to the industry, especially to the petroleum industry where these fluids are commonly used during hydraulic fracturing of hydrocarbon reservoirs.« less

A master-slave parallel hybrid multi-objective evolutionary algorithm for groundwater remediation design under general hydrogeological conditions

NASA Astrophysics Data System (ADS)

Wu, J.; Yang, Y.; Luo, Q.; Wu, J.

2012-12-01

This study presents a new hybrid multi-objective evolutionary algorithm, the niched Pareto tabu search combined with a genetic algorithm (NPTSGA), whereby the global search ability of niched Pareto tabu search (NPTS) is improved by the diversification of candidate solutions arose from the evolving nondominated sorting genetic algorithm II (NSGA-II) population. Also, the NPTSGA coupled with the commonly used groundwater flow and transport codes, MODFLOW and MT3DMS, is developed for multi-objective optimal design of groundwater remediation systems. The proposed methodology is then applied to a large-scale field groundwater remediation system for cleanup of large trichloroethylene (TCE) plume at the Massachusetts Military Reservation (MMR) in Cape Cod, Massachusetts. Furthermore, a master-slave (MS) parallelization scheme based on the Message Passing Interface (MPI) is incorporated into the NPTSGA to implement objective function evaluations in distributed processor environment, which can greatly improve the efficiency of the NPTSGA in finding Pareto-optimal solutions to the real-world application. This study shows that the MS parallel NPTSGA in comparison with the original NPTS and NSGA-II can balance the tradeoff between diversity and optimality of solutions during the search process and is an efficient and effective tool for optimizing the multi-objective design of groundwater remediation systems under complicated hydrogeologic conditions.

Solvation effects on chemical shifts by embedded cluster integral equation theory.

PubMed

Frach, Roland; Kast, Stefan M

2014-12-11

The accurate computational prediction of nuclear magnetic resonance (NMR) parameters like chemical shifts represents a challenge if the species studied is immersed in strongly polarizing environments such as water. Common approaches to treating a solvent in the form of, e.g., the polarizable continuum model (PCM) ignore strong directional interactions such as H-bonds to the solvent which can have substantial impact on magnetic shieldings. We here present a computational methodology that accounts for atomic-level solvent effects on NMR parameters by extending the embedded cluster reference interaction site model (EC-RISM) integral equation theory to the prediction of chemical shifts of N-methylacetamide (NMA) in aqueous solution. We examine the influence of various so-called closure approximations of the underlying three-dimensional RISM theory as well as the impact of basis set size and different treatment of electrostatic solute-solvent interactions. We find considerable and systematic improvement over reference PCM and gas phase calculations. A smaller basis set in combination with a simple point charge model already yields good performance which can be further improved by employing exact electrostatic quantum-mechanical solute-solvent interaction energies. A larger basis set benefits more significantly from exact over point charge electrostatics, which can be related to differences of the solvent's charge distribution.

Tackling creativity at its roots: Evidence for different patterns of EEG alpha activity related to convergent and divergent modes of task processing

PubMed Central

Jauk, Emanuel; Benedek, Mathias; Neubauer, Aljoscha C.

2012-01-01

The distinction between convergent and divergent cognitive processes given by Guilford (1956) had a strong influence on the empirical research on creative thinking. Neuroscientific studies typically find higher event-related synchronization in the EEG alpha rhythm for individuals engaged in creative ideation tasks compared to intelligence-related tasks. This study examined, whether these neurophysiological effects can also be found when both cognitive processing modes (convergent vs. divergent) are assessed by means of the same task employing a simple variation of instruction. A sample of 55 participants performed the alternate uses task as well as a more basic word association task while EEG was recorded. On a trial-by-trial basis, participants were either instructed to find a most common solution (convergent condition) or a most uncommon solution (divergent condition). The answers given in the divergent condition were in both tasks significantly more original than those in the convergent condition. Moreover, divergent processing was found to involve higher task-related EEG alpha power than convergent processing in both the alternate uses task and the word association task. EEG alpha synchronization can hence explicitly be associated with divergent cognitive processing rather than with general task characteristics of creative ideation tasks. Further results point to a differential involvement of frontal and parietal cortical areas by individuals of lower versus higher trait creativity. PMID:22390860

Electromagnetic-radiation absorption by water

NASA Astrophysics Data System (ADS)

Lunkenheimer, P.; Emmert, S.; Gulich, R.; Köhler, M.; Wolf, M.; Schwab, M.; Loidl, A.

2017-12-01

Why does a microwave oven work? How does biological tissue absorb electromagnetic radiation? Astonishingly, we do not have a definite answer to these simple questions because the microscopic processes governing the absorption of electromagnetic waves by water are largely unclarified. This absorption can be quantified by dielectric loss spectra, which reveal a huge peak at a frequency of the exciting electric field of about 20 GHz and a gradual tailing off toward higher frequencies. The microscopic interpretation of such spectra is highly controversial and various superpositions of relaxation and resonance processes ascribed to single-molecule or molecule-cluster motions have been proposed for their analysis. By combining dielectric, microwave, THz, and far-infrared spectroscopy, here we provide nearly continuous temperature-dependent broadband spectra of water. Moreover, we find that corresponding spectra for aqueous solutions reveal the same features as pure water. However, in contrast to the latter, crystallization in these solutions can be avoided by supercooling. As different spectral contributions tend to disentangle at low temperatures, this enables us to deconvolute them when approaching the glass transition under cooling. We find that the overall spectral development, including the 20 GHz feature (employed for microwave heating), closely resembles the behavior known for common supercooled liquids. Thus water's absorption of electromagnetic waves at room temperature is not unusual but very similar to that of glass-forming liquids at elevated temperatures, deep in the low-viscosity liquid regime, and should be interpreted along similar lines.

Exact solutions in 3D gravity with torsion

NASA Astrophysics Data System (ADS)

González, P. A.; Vásquez, Yerko

2011-08-01

We study the three-dimensional gravity with torsion given by the Mielke-Baekler (MB) model coupled to gravitational Chern-Simons term, and that possess electric charge described by Maxwell-Chern-Simons electrodynamics. We find and discuss this theory's charged black holes solutions and uncharged solutions. We find that for vanishing torsion our solutions by means of a coordinate transformation can be written as three-dimensional Chern-Simons black holes. We also discuss a special case of this theory, Topologically Massive Gravity (TMG) at chiral point, and we show that the logarithmic solution of TMG is also a solution of the MB model at a fixed point in the space of parameters. Furthermore, we show that our solutions generalize Gödel type solutions in a particular case. Also, we recover BTZ black hole in Riemann-Cartan spacetime for vanishing charge.

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

Dehghani, M.H.; Department of Physics, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1; Perimeter Institute for Theoretical Physics, 35 Caroline Street North, Waterloo, Ontario

We investigate the existence of Taub-NUT (Newman-Unti-Tamburino) and Taub-bolt solutions in Gauss-Bonnet gravity and obtain the general form of these solutions in d dimensions. We find that for all nonextremal NUT solutions of Einstein gravity having no curvature singularity at r=N, there exist NUT solutions in Gauss-Bonnet gravity that contain these solutions in the limit that the Gauss-Bonnet parameter {alpha} goes to zero. Furthermore there are no NUT solutions in Gauss-Bonnet gravity that yield nonextremal NUT solutions to Einstein gravity having a curvature singularity at r=N in the limit {alpha}{yields}0. Indeed, we have nonextreme NUT solutions in 2+2k dimensions withmore » nontrivial fibration only when the 2k-dimensional base space is chosen to be CP{sup 2k}. We also find that the Gauss-Bonnet gravity has extremal NUT solutions whenever the base space is a product of 2-torii with at most a two-dimensional factor space of positive curvature. Indeed, when the base space has at most one positively curved two-dimensional space as one of its factor spaces, then Gauss-Bonnet gravity admits extreme NUT solutions, even though there a curvature singularity exists at r=N. We also find that one can have bolt solutions in Gauss-Bonnet gravity with any base space with factor spaces of zero or positive constant curvature. The only case for which one does not have bolt solutions is in the absence of a cosmological term with zero curvature base space.« less

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

Dehghani, M.H.; Research Institute for Astrophysics and Astronomy of Maragha; Khodam-Mohammadi, A.

First, we construct the Taub-NUT/bolt solutions of (2k+2)-dimensional Einstein-Maxwell gravity, when all the factor spaces of 2k-dimensional base space B have positive curvature. These solutions depend on two extra parameters, other than the mass and the NUT charge. These are electric charge q and electric potential at infinity V. We investigate the existence of Taub-NUT solutions and find that in addition to the two conditions of uncharged NUT solutions, there exist two extra conditions. These two extra conditions come from the regularity of vector potential at r=N and the fact that the horizon at r=N should be the outer horizonmore » of the NUT charged black hole. We find that the NUT solutions in 2k+2 dimensions have no curvature singularity at r=N, when the 2k-dimensional base space is chosen to be CP{sup 2k}. For bolt solutions, there exists an upper limit for the NUT parameter which decreases as the potential parameter increases. Second, we study the thermodynamics of these spacetimes. We compute temperature, entropy, charge, electric potential, action and mass of the black hole solutions, and find that these quantities satisfy the first law of thermodynamics. We perform a stability analysis by computing the heat capacity, and show that the NUT solutions are not thermally stable for even k's, while there exists a stable phase for odd k's, which becomes increasingly narrow with increasing dimensionality and wide with increasing V. We also study the phase behavior of the 4 and 6 dimensional bolt solutions in canonical ensemble and find that these solutions have a stable phase, which becomes smaller as V increases.« less

Castroviejo Lecture 2009: 40 years in search of the perfect contact lens.

PubMed

Cavanagh, H Dwight; Robertson, Danielle M; Petroll, W Matthew; Jester, James V

2010-10-01

To identify the pathophysiological changes produced by contact lens wear that predispose the cornea to infection and search for prospective modifiable risk factors that could reduce the incidence of this critical complication in millions of patients worldwide. Significant experimental and clinical publications are reviewed, and the results of ongoing studies are presented. Pseudomonas aeruginosa (PA) is the most common pathogen causing lens-related infectious keratitis over 3 decades. Contact lens wear can increase the risk of infection by increasing surface cell PA binding, thereby promoting invasion between broken tight junctions and initiating direct intracellular invasion mediated by lens-induced membrane lipid rafts. Prevention of upregulation of specific surface-binding receptors for PA with concomitant increase in infection risk is a zero damage game where independent interactions among lens type, mode of wear, oxygen transmissibility, polymer, and toxic effects of associated care solutions ideally should collectively produce no increased ability for PA to attach and/or to invade, thus minimizing the risk for lens-associated infections. The specific hypothesis tested is, "no increased epithelial surface damage... no increased PA binding or invasion... no increased risk for infection." Testing of this new paradigm has been performed in vitro and in animal and human clinical trials and correlated clinically with relative risk results from robust current epidemiological studies. Results to date clearly support the use of lens-related increases in PA binding (bench) as a noninvasive clinical predictor of risk for lens-related infection in subsequent large-scale population studies (bedside). Currently, results suggest that use of common commercial multipurpose lens care solutions with soft lenses may alone significantly increase infection risk by enhancing lens-related PA binding as compared with use of nonpreserved solutions (hydrogen peroxide). Clinical testing also shows that only peroxide solutions show significant disinfection capability against amoebic cysts. Further case-control studies to examine relative risk for infection by lens type and lens care solution are urgently needed. Millions of patients are dependent on contact lenses for vision worldwide; over 3 decades, lens use has increased, although risk for lens-related infection has remained stubbornly unchanged. Unfortunately, recent introduction of a new generation of hyper-oxygen transmissible lenses used with traditional multipurpose lens care solutions has not lowered overall risks for lens-related infections; however, similar lenses used with nonpreserved care solutions (peroxide) recently demonstrated no significant increases in PA binding in a 1-year clinical trial. Collectively, these findings along with the urgent need for amoebic cysticidal disinfection have led to a current recommendation to patients to use nonpreserved (hydrogen peroxide) care solutions in soft lens wear.

Unbraiding the bounce: superluminality around the corner

NASA Astrophysics Data System (ADS)

Dobre, David A.; Frolov, Andrei V.; Gálvez Ghersi, José T.; Ramazanov, Sabir; Vikman, Alexander

2018-03-01

We study a particular realization of the cosmological bounce scenario proposed recently by Ijjas and Steinhardt in [1]. First, we find that their bouncing solution starts from a divergent sound speed and ends with its vanishing. Thus, the solution connects two strongly coupled configurations. These pathologies are separated from the bouncing regime by only a few Planck times. We then reveal the exact structure of the Lagrangian, which reproduces this bouncing solution. This reconstruction allowed us to consider other cosmological solutions of the theory and analyze the phase space. In particular, we find other bouncing solutions and solutions with superluminal sound speed. These stable superluminal states can be continuously transformed into the solution constructed by Ijjas and Steinhardt. We discuss the consequences of this feature for a possible UV-completion.

Rational Solutions and Lump Solutions of the Potential YTSF Equation

NASA Astrophysics Data System (ADS)

Sun, Hong-Qian; Chen, Ai-Hua

2017-07-01

By using of the bilinear form, rational solutions and lump solutions of the potential Yu-Toda-Sasa-Fukuyama (YTSF) equation are derived. Dynamics of the fundamental lump solution, n1-order lump solutions, and N-lump solutions are studied for some special cases. We also find some interaction behaviours of solitary waves and one lump of rational solutions.

Salty popcorn in a homogeneous low-dimensional toy model of holographic QCD

NASA Astrophysics Data System (ADS)

Elliot-Ripley, Matthew

2017-04-01

Recently, a homogeneous ansatz has been used to study cold dense nuclear matter in the Sakai-Sugimoto model of holographic QCD. To justify this homogeneous approximation we here investigate a homogeneous ansatz within a low-dimensional toy version of Sakai-Sugimoto to study finite baryon density configurations and compare it to full numerical solutions. We find the ansatz corresponds to enforcing a dyon salt arrangement in which the soliton solutions are split into half-soliton layers. Within this ansatz we find analogues of the proposed baryonic popcorn transitions, in which solutions split into multiple layers in the holographic direction. The homogeneous results are found to qualitatively match the full numerical solutions, lending confidence to the homogeneous approximations of the full Sakai-Sugimoto model. In addition, we find exact compact solutions in the high density, flat space limit which demonstrate the existence of further popcorn transitions to three layers and beyond.

On the Relationship between Solution Strategies in Two Mental Rotation Tasks

ERIC Educational Resources Information Center

Janssen, Anne B.; Geiser, Christian

2010-01-01

Individual differences in solution strategies have frequently been reported for different measures of mental rotation (MR) ability. In the present study (N=346 German students), we investigated the relationship between solution strategies on two tests commonly used to identify different patterns of strategies: the Mental Rotations Test (MRT;…

Biliary strictures complicating living donor liver transplantation: Problems, novel insights and solutions.

PubMed

Rao, Harshavardhan B; Prakash, Arjun; Sudhindran, Surendran; Venu, Rama P

2018-05-21

Biliary stricture complicating living donor liver transplantation (LDLT) is a relatively common complication, occurring in most transplant centres across the world. Cases of biliary strictures are more common in LDLT than in deceased donor liver transplantation. Endoscopic management is the mainstay for biliary strictures complicating LDLT and includes endoscopic retrograde cholangiography, sphincterotomy and stent placement (with or without balloon dilatation). The efficacy and safety profiles as well as outcomes of endoscopic management of biliary strictures complicating LDLT is an area that needs to be viewed in isolation, owing to its unique set of problems and attending complications; as such, it merits a tailored approach, which is yet to be well established. The diagnostic criteria applied to these strictures are not uniform and are over-reliant on imaging studies showing an anastomotic narrowing. It has to be kept in mind that in the setting of LDLT, a subjective anastomotic narrowing is present in most cases due to a mismatch in ductal diameters. However, whether this narrowing results in a functionally significant narrowing is a question that needs further study. In addition, wide variation in the endotherapy protocols practised in most centres makes it difficult to interpret the results and hampers our understanding of this topic. The outcome definition for endotherapy is also heterogenous and needs to be standardised to allow for comparison of data in this regard and establish a clinical practice guideline. There have been multiple studies in this area in the last 2 years, with novel findings that have provided solutions to some of these issues. This review endeavours to incorporate these new findings into the wider understanding of endotherapy for biliary strictures complicating LDLT, with specific emphasis on diagnosis of strictures in the LDLT setting, endotherapy protocols and outcome definitions. An attempt is made to present the best management options currently available as well as directions for future research in the area.

Ion Transport in Confined Geometries below the Nanoscale: Access Resistance Dominates Protein Channel Conductance in Diluted Solutions.

PubMed

Alcaraz, Antonio; López, M Lidón; Queralt-Martín, María; Aguilella, Vicente M

2017-10-24

Synthetic nanopores and mesoscopic protein channels have common traits like the importance of electrostatic interactions between the permeating ions and the nanochannel. Ion transport at the nanoscale occurs under confinement conditions so that the usual assumptions made in microfluidics are challenged, among others, by interfacial effects such as access resistance (AR). Here, we show that a sound interpretation of electrophysiological measurements in terms of channel ion selective properties requires the consideration of interfacial effects, up to the point that they dominate protein channel conductance in diluted solutions. We measure AR in a large ion channel, the bacterial porin OmpF, by means of single-channel conductance measurements in electrolyte solutions containing varying concentrations of high molecular weight PEG, sterically excluded from the pore. Comparison of experiments performed in charged and neutral planar membranes shows that lipid surface charges modify the ion distribution and determine the value of AR, indicating that lipid molecules are more than passive scaffolds even in the case of large transmembrane proteins. We also found that AR may reach up to 80% of the total channel conductance in diluted solutions, where electrophysiological recordings register essentially the AR of the system and depend marginally on the pore characteristics. These findings may have implications for several low aspect ratio biological channels that perform their physiological function in a low ionic strength and macromolecule crowded environment, just the two conditions enhancing the AR contribution.

Changes in colloid solution sales in Nordic countries.

PubMed

Kongsgaard, U E; Holtan, A; Perner, A

2018-04-01

Administration of resuscitation fluid is a common intervention in the treatment of critically ill patients, but the right choice of fluid is still a matter of debate. Changes in medical practice are based on new evidence and guidelines as well as traditions and personal preferences. Official warnings against the use of hydroxyl-ethyl-starch (HES) solutions have been issued. Nordic guidelines have issued several strong recommendations favouring crystalloids over colloids in all patient groups. Our objective was to describe the patterns of colloid use in Nordic countries from 2012 to 2016. The data were obtained from companies that provide pharmaceutical statistics in different countries. The data are sales figures from pharmaceutical companies to pharmacies and health institutions. We found a 56% reduction in the total sales of all colloids in Nordic countries over a 5-year period. These findings were mainly related to a 92% reduction in the sales of HES solutions. A reduction in sales of other synthetic colloids has also occurred. During the same period, we found a 46% increase in albumin sales, but these numbers varied between Nordic countries. The general reduction in colloid sales likely reflects the recommendation that colloids should be used only in special circumstances. The dramatic reduction in the sales of HES solutions was expected given evidence of harm and the official warnings. The steady increase in albumin sales and the notable differences between the five Nordic countries cannot be explained. © 2018 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

A new generalized exponential rational function method to find exact special solutions for the resonance nonlinear Schrödinger equation

NASA Astrophysics Data System (ADS)

Ghanbari, Behzad; Inc, Mustafa

2018-04-01

The present paper suggests a novel technique to acquire exact solutions of nonlinear partial differential equations. The main idea of the method is to generalize the exponential rational function method. In order to examine the ability of the method, we consider the resonant nonlinear Schrödinger equation (R-NLSE). Many variants of exact soliton solutions for the equation are derived by the proposed method. Physical interpretations of some obtained solutions is also included. One can easily conclude that the new proposed method is very efficient and finds the exact solutions of the equation in a relatively easy way.

Analytical solutions for systems of partial differential-algebraic equations.

PubMed

Benhammouda, Brahim; Vazquez-Leal, Hector

2014-01-01

This work presents the application of the power series method (PSM) to find solutions of partial differential-algebraic equations (PDAEs). Two systems of index-one and index-three are solved to show that PSM can provide analytical solutions of PDAEs in convergent series form. What is more, we present the post-treatment of the power series solutions with the Laplace-Padé (LP) resummation method as a useful strategy to find exact solutions. The main advantage of the proposed methodology is that the procedure is based on a few straightforward steps and it does not generate secular terms or depends of a perturbation parameter.

The effect of deep eutectic solvents on catalytic function and structure of bovine liver catalase.

PubMed

Harifi-Mood, Ali Reza; Ghobadi, Roohollah; Divsalar, Adeleh

2017-02-01

Aqueous solutions of reline and glyceline, the most common deep eutectic solvents, were used as a medium for Catalase reaction. By some spectroscopic methods such as UV-vis, fluorescence and circular dichroism (CD) function and structure of Catalase were investigated in aqueous solutions of reline and glyceline. These studies showed that the binding affinity of the substrate to the enzyme increased in the presence of 100mM glyceline solution, which contrasts with reline solution that probably relates to instructive changes in secondary structure of protein. Meanwhile, enzyme remained nearly 70% and 80% active in this concentration of glyceline and reline solutions respectively. In the high concentration of DES solutions, enzyme became mainly inactive but surprisingly stayed in nearly 40% active in choline chloride solution, which is the common ion species in reline and glyceline solvents. It is proposed that the chaotropic nature of choline cation might stop the reducing trend of activity in concentrated choline chloride solutions but this instructive effect is lost in aqueous deep eutectic solvents. In this regard, the presence of various concentrations of deep eutectic solvents in the aqueous media of human cells would be an activity adjuster for this important enzyme in its different operation conditions. Copyright © 2016 Elsevier B.V. All rights reserved.

Modelling and Accuracy in a Bim Environment for Planned Conservation: the Apartment of Troia of Giulio Romano

NASA Astrophysics Data System (ADS)

Adami, A.; Scala, B.; Spezzoni, A.

2017-02-01

Modeling of Cultural Heritage in a BIM environment, and in general of existing buildings, requires special attention because there are two diametrically opposed possibilities. On the one hand the attempt is to realize a very complex and accurate model, in order to provide the most comprehensive representation of the architecture as possible. The opposite position leads to build a very schematic and symbolic model of as-built architecture. It is not easy to determine which is the right balance between these two attitudes because each architecture requires a personalized approach and not standards. It's, however, necessary to find rules to figure out which items are represented, what is the minimum level of detail to consider adequate and how to deal with alterations from simple and linear geometries. These two facing possibilities deal with different goals and tools. In the field of restoration or planned conservation, that is the most common approach for existing buildings, the attention focuses on the exceptions and particularities of each architecture: the important aspect is to understand and describe exactly each part as a singularity (as it is). In this context it is very difficult to find a standard or a common solution. The first possibility of modelling seems to be very close to this approach, but it clashes with two important aspects. A first problem concerns the modelling software. Usually commercial BIM modelling software doesn't allow to realize very complex and high detailed solutions. They prefer working with predefined families and try to categorize each element in standard solution. The possibility to build new families is expected, but it often requires a lot of time. The second difficulty is the real efficiency of such an accurate model. In fact, it could be very difficult to link external elements to the model or use it in many traditional BIM applications. In this paper, we suggest another possible approach that represents the first result of a research about the modelling of Cultural Heritage for BIM application. The proposed solution aims to give as much information as possible about the architecture, and, at the same time, to guarantee a higher efficiency. In this case we considered commercial BIM software like Revit or Archicad. They are the most widespread and well-known software BIM oriented and they also allow the use of their embedded database structure. The core of our solution is to describe the architecture not only by a 3D model but also by the representation of the reliability of the accuracy of the model itself. In this way we try to combine the necessity of working with commercial software, in which it is difficult to be very accurate, and the information about the real object. In historical complex architecture, for example, it is very difficult to find a straight and planar wall. It is quite difficult, or at least time consuming, to model that kind of wall with high accuracy. But it is possible to represent the real wall by a schematic wall with a false color map which describes where the 3D model is well fitting and where there are some differences. In this way we don't lose any information but, at the same time, we have a very usable BIM model.

Estimating the safety benefits of context sensitive solutions.

DOT National Transportation Integrated Search

2011-11-01

Context Sensitive Solutions (CSS), also commonly known by the original name Context Sensitive Design : (CSD), is an alternative approach to the conventional transportation-oriented decision-making and design : processes. The CSS approach can be used ...

Ovalbumin labeling with p-hydroxymercurybenzoate: The effect of different denaturing agents and the kinetics of reaction.

PubMed

Campanella, Beatrice; Onor, Massimo; Biancalana, Lorenzo; D'Ulivo, Alessandro; Bramanti, Emilia

2015-08-15

The aim of our study was to investigate how denaturing agents commonly used in protein analysis influence the labeling between a reactive molecule and proteins. For this reason, we investigated the labeling of ovalbumin (OVA) as a globular model protein with p-hydroxymercurybenzoate (pHMB) in its native state (phosphate buffer solution) and in different denaturing conditions (8 molL(-1) urea, 3 molL(-1) guanidinium thiocyanate, 6 molL(-1) guanidinium chloride, 0.2% sodium dodecyl sulfate, and 20% methanol). In addition to chemical denaturation, thermal denaturation was also tested. The protein was pre-column simultaneously denatured and derivatized, and the pHMB-labeled denatured OVA complexes were analyzed by size exclusion chromatography (SEC) coupled online with chemical vapor generation-atomic fluorescence spectrometry (CVG-AFS). The number of -SH groups titrated greatly depends on the protein structure in solution. Indeed, we found that, depending on the adopted denaturing conditions, OVA gave different aggregate species that influence the complexation process. The results were compared with those obtained by a common alternative procedure for the titration of -SH groups that employs monobromobimane (mBBr) as tagging molecule and molecular fluorescence spectroscopy as detection technique. We also investigated the labeling kinetics for denatured OVA and pHMB, finding that the 4 thiolic groups of OVA have a very different reactivity toward mercury labeling, in agreement with previous studies. Copyright © 2015 Elsevier Inc. All rights reserved.

Human performance on the traveling salesman problem.

PubMed

MacGregor, J N; Ormerod, T

1996-05-01

Two experiments on performance on the traveling salesman problem (TSP) are reported. The TSP consists of finding the shortest path through a set of points, returning to the origin. It appears to be an intransigent mathematical problem, and heuristics have been developed to find approximate solutions. The first experiment used 10-point, the second, 20-point problems. The experiments tested the hypothesis that complexity of TSPs is a function of number of nonboundary points, not total number of points. Both experiments supported the hypothesis. The experiments provided information on the quality of subjects' solutions. Their solutions clustered close to the best known solutions, were an order of magnitude better than solutions produced by three well-known heuristics, and on average fell beyond the 99.9th percentile in the distribution of random solutions. The solution process appeared to be perceptually based.

Common aero vehicle autonomous reentry trajectory optimization satisfying waypoint and no-fly zone constraints

NASA Astrophysics Data System (ADS)

Jorris, Timothy R.

2007-12-01

To support the Air Force's Global Reach concept, a Common Aero Vehicle is being designed to support the Global Strike mission. "Waypoints" are specified for reconnaissance or multiple payload deployments and "no-fly zones" are specified for geopolitical restrictions or threat avoidance. Due to time critical targets and multiple scenario analysis, an autonomous solution is preferred over a time-intensive, manually iterative one. Thus, a real-time or near real-time autonomous trajectory optimization technique is presented to minimize the flight time, satisfy terminal and intermediate constraints, and remain within the specified vehicle heating and control limitations. This research uses the Hypersonic Cruise Vehicle (HCV) as a simplified two-dimensional platform to compare multiple solution techniques. The solution techniques include a unique geometric approach developed herein, a derived analytical dynamic optimization technique, and a rapidly emerging collocation numerical approach. This up-and-coming numerical technique is a direct solution method involving discretization then dualization, with pseudospectral methods and nonlinear programming used to converge to the optimal solution. This numerical approach is applied to the Common Aero Vehicle (CAV) as the test platform for the full three-dimensional reentry trajectory optimization problem. The culmination of this research is the verification of the optimality of this proposed numerical technique, as shown for both the two-dimensional and three-dimensional models. Additionally, user implementation strategies are presented to improve accuracy and enhance solution convergence. Thus, the contributions of this research are the geometric approach, the user implementation strategies, and the determination and verification of a numerical solution technique for the optimal reentry trajectory problem that minimizes time to target while satisfying vehicle dynamics and control limitation, and heating, waypoint, and no-fly zone constraints.

Solution-state structure and affinities of cyclodextrin: Fentanyl complexes by nuclear magnetic resonance spectroscopy and molecular dynamics simulation

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

Mayer, Brian P.; Kennedy, Daniel J.; Lau, Edmond Y.

Cyclodextrins (CDs) are investigated for their ability to form inclusion complexes with the analgesic fentanyl and three similar molecules: acetylfentanyl, thiofentanyl, and acetylthiofentanyl. Stoichiometry, binding strength, and complex structure are revealed through nuclear magnetic resonance (NMR) techniques and discussed in terms of molecular dynamics (MD) simulations. It was found that β-cyclodextrin is generally capable of forming the strongest complexes with the fentanyl panel. Two-dimensional NMR data and computational chemical calculations are used to derive solution-state structures of the complexes. Binding of the fentanyls to the CDs occurs at the amide phenyl ring, leaving the majority of the molecule solvated bymore » water, an observation common to all four fentanyls. This finding suggests a universal binding behavior, as the vast majority of previously synthesized fentanyl analogues contain this structural moiety. Furthermore, this baseline study serves as the most complete work on CD:fentanyl complexes to date and provides the insights into strategies for producing future generations of designer cyclodextrins capable of stronger and more selective complexation of fentanyl and its analogues.« less

Solution-state structure and affinities of cyclodextrin: Fentanyl complexes by nuclear magnetic resonance spectroscopy and molecular dynamics simulation

DOE PAGES

Mayer, Brian P.; Kennedy, Daniel J.; Lau, Edmond Y.; ...

2016-02-04

Cyclodextrins (CDs) are investigated for their ability to form inclusion complexes with the analgesic fentanyl and three similar molecules: acetylfentanyl, thiofentanyl, and acetylthiofentanyl. Stoichiometry, binding strength, and complex structure are revealed through nuclear magnetic resonance (NMR) techniques and discussed in terms of molecular dynamics (MD) simulations. It was found that β-cyclodextrin is generally capable of forming the strongest complexes with the fentanyl panel. Two-dimensional NMR data and computational chemical calculations are used to derive solution-state structures of the complexes. Binding of the fentanyls to the CDs occurs at the amide phenyl ring, leaving the majority of the molecule solvated bymore » water, an observation common to all four fentanyls. This finding suggests a universal binding behavior, as the vast majority of previously synthesized fentanyl analogues contain this structural moiety. Furthermore, this baseline study serves as the most complete work on CD:fentanyl complexes to date and provides the insights into strategies for producing future generations of designer cyclodextrins capable of stronger and more selective complexation of fentanyl and its analogues.« less

Optimizing DNA assembly based on statistical language modelling.

PubMed

Fang, Gang; Zhang, Shemin; Dong, Yafei

2017-12-15

By successively assembling genetic parts such as BioBrick according to grammatical models, complex genetic constructs composed of dozens of functional blocks can be built. However, usually every category of genetic parts includes a few or many parts. With increasing quantity of genetic parts, the process of assembling more than a few sets of these parts can be expensive, time consuming and error prone. At the last step of assembling it is somewhat difficult to decide which part should be selected. Based on statistical language model, which is a probability distribution P(s) over strings S that attempts to reflect how frequently a string S occurs as a sentence, the most commonly used parts will be selected. Then, a dynamic programming algorithm was designed to figure out the solution of maximum probability. The algorithm optimizes the results of a genetic design based on a grammatical model and finds an optimal solution. In this way, redundant operations can be reduced and the time and cost required for conducting biological experiments can be minimized. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

Efficient and Robust Optimization for Building Energy Simulation

PubMed Central

Pourarian, Shokouh; Kearsley, Anthony; Wen, Jin; Pertzborn, Amanda

2016-01-01

Efficiently, robustly and accurately solving large sets of structured, non-linear algebraic and differential equations is one of the most computationally expensive steps in the dynamic simulation of building energy systems. Here, the efficiency, robustness and accuracy of two commonly employed solution methods are compared. The comparison is conducted using the HVACSIM+ software package, a component based building system simulation tool. The HVACSIM+ software presently employs Powell’s Hybrid method to solve systems of nonlinear algebraic equations that model the dynamics of energy states and interactions within buildings. It is shown here that the Powell’s method does not always converge to a solution. Since a myriad of other numerical methods are available, the question arises as to which method is most appropriate for building energy simulation. This paper finds considerable computational benefits result from replacing the Powell’s Hybrid method solver in HVACSIM+ with a solver more appropriate for the challenges particular to numerical simulations of buildings. Evidence is provided that a variant of the Levenberg-Marquardt solver has superior accuracy and robustness compared to the Powell’s Hybrid method presently used in HVACSIM+. PMID:27325907

Efficient and Robust Optimization for Building Energy Simulation.

PubMed

Pourarian, Shokouh; Kearsley, Anthony; Wen, Jin; Pertzborn, Amanda

2016-06-15

Efficiently, robustly and accurately solving large sets of structured, non-linear algebraic and differential equations is one of the most computationally expensive steps in the dynamic simulation of building energy systems. Here, the efficiency, robustness and accuracy of two commonly employed solution methods are compared. The comparison is conducted using the HVACSIM+ software package, a component based building system simulation tool. The HVACSIM+ software presently employs Powell's Hybrid method to solve systems of nonlinear algebraic equations that model the dynamics of energy states and interactions within buildings. It is shown here that the Powell's method does not always converge to a solution. Since a myriad of other numerical methods are available, the question arises as to which method is most appropriate for building energy simulation. This paper finds considerable computational benefits result from replacing the Powell's Hybrid method solver in HVACSIM+ with a solver more appropriate for the challenges particular to numerical simulations of buildings. Evidence is provided that a variant of the Levenberg-Marquardt solver has superior accuracy and robustness compared to the Powell's Hybrid method presently used in HVACSIM+.

Paint and Click: Unified Interactions for Image Boundaries

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

Summa, B.; Gooch, A. A.; Scorzelli, G.

Image boundaries are a fundamental component of many interactive digital photography techniques, enabling applications such as segmentation, panoramas, and seamless image composition. Interactions for image boundaries often rely on two complementary but separate approaches: editing via painting or clicking constraints. In this work, we provide a novel, unified approach for interactive editing of pairwise image boundaries that combines the ease of painting with the direct control of constraints. Rather than a sequential coupling, this new formulation allows full use of both interactions simultaneously, giving users unprecedented flexibility for fast boundary editing. To enable this new approach, we provide technical advancements.more » In particular, we detail a reformulation of image boundaries as a problem of finding cycles, expanding and correcting limitations of the previous work. Our new formulation provides boundary solutions for painted regions with performance on par with state-of-the-art specialized, paint-only techniques. In addition, we provide instantaneous exploration of the boundary solution space with user constraints. Finally, we provide examples of common graphics applications impacted by our new approach.« less

Enhancing Science Teaching through Performing Marbling Art Using Basic Solutions and Base Indicators

ERIC Educational Resources Information Center

Çil, Emine; Çelik, Kevser; Maçin, Tuba; Demirbas, Gülay; Gökçimen, Özlem

2014-01-01

Basic solutions are an indispensable part of our daily life. Basic solutions are commonly used in industries such as the textile industry, oil refineries, the fertilizer industry, and pharmaceutical products. Most cleaning agents, such as soap, detergent, and bleach, and some of our foods, such as chocolate and eggs, include bases. Bases are the…

Reflection on Solutions in the Form of Refutation Texts versus Problem Solving: The Case of 8th Graders Studying Simple Electric Circuits

ERIC Educational Resources Information Center

Safadi, Rafi; Safadi, Ekhlass; Meidav, Meir

2017-01-01

This study compared students' learning in troubleshooting and problem solving activities. The troubleshooting activities provided students with solutions to conceptual problems in the form of refutation texts; namely, solutions that portray common misconceptions, refute them, and then present the accepted scientific ideas. They required students…

Survey of three-dimensional numerical estuarine models

USGS Publications Warehouse

Cheng, Ralph T.; Smith, Peter E.

1989-01-01

This paper surveys the existing 3-D estuarine hydrodynamic and solute transport models by a review of the commonly used assumptions and approximations, and by an examination of the methods of solution. The model formulations, methods of solution, and known applications are surveyed and summarized in tables. In conclusion, the authors present their modeling philosophy and suggest future research needs.

Kinetics of the Fading of Phenolphthalein in Alkaline Solution.

ERIC Educational Resources Information Center

Nicholson, Lois

1989-01-01

Described is an experiment which illustrates pseudo-first-order kinetics in the fading of a common indicator in an alkaline solution. Included are background information, details of materials used, laboratory procedures, and sample results. (CW)

LEACHING BOUNDARY IN CEMENT-BASED WASTE FORMS

EPA Science Inventory

Cement-based fixation systems are among the most commonly employed stabilization/solidification techniques. These cement haste mixtures, however, are vulnerable to ardic leaching solutions. Leaching of cement-based waste forms in acetic acid solutions with different acidic streng...

A Continuous Variation Study of Heats of Neutralization.

ERIC Educational Resources Information Center

Mahoney, Dennis W.; And Others

1981-01-01

Suggests that students study heats of neutralization of a 1 M solution of an unknown acid by 1 M solution of a strong base using the method continuous variation. Reviews results using several common acids. (SK)

Adaptive Façade: Variant-Finding using Shape Grammar

NASA Astrophysics Data System (ADS)

Tomasowa, Riva; Utama Sjarifudin, Firza

2017-12-01

Modular façade construction has never been better since the birth of computer-aided manufacturing which bridges the modeling phase into the manufacturing phase for escalating the mass production. This comes to a result that the identity of a product or a building façade will commonly generate in the same way that the initial design was intended to. Rectifying the early model will then greatly impact the process later. The aim of this paper is to propose a way to solve these two challenges, without risking the manufacturing process, but more to explore the potential designs. Shape grammar is used to conceive more designs in the early stage, derived from the initial product - the modular adaptive façade system. The derivations are then tested through simulation to state the efficacy of the models. We find that the workflow somehow contributes to the better design and engineering process as well as the solution allows diversification in the façade expressions.

Preparation of pure chitosan film using ternary solvents and its super absorbency.

PubMed

Wang, Xuejun; Lou, Tao; Zhao, Wenhua; Song, Guojun

2016-11-20

Chemical modification and graft copolymerization were commonly adopted to prepare super absorbent materials. However, physical microstructure of pure chitosan film was optimized to improve the water uptake capacity in this study. Chitosan films with micro-nanostructure were prepared by a ternary solvent system. The optimal process parameters are 1% acetic acid water solution: dioxane: dimethyl sulfoxide=90: 2.5: 7.5 (v/v/v) with chitosan concentration at 1.25% (w/v). The water uptake capacity of the chitosan film prepared under the optimal process parameters was 896g/g. The prepared chitosan films also exhibited high water uptake capacity in response to external stimuli such as temperature, pH and salt. This finding may provide another way for improving the water absorbency. The pure chitosan film may find potential applications especially in the fields of hygienic products and biomedicine due to its super water absorbency and nontoxicity. Copyright © 2016 Elsevier Ltd. All rights reserved.

Rotational motions for teleseismic surface waves

NASA Astrophysics Data System (ADS)

Lin, Chin-Jen; Huang, Han-Pang; Pham, Nguyen Dinh; Liu, Chun-Chi; Chi, Wu-Cheng; Lee, William H. K.

2011-08-01

We report the findings for the first teleseismic six degree-of-freedom (6-DOF) measurements including three components of rotational motions recorded by a sensitive rotation-rate sensor (model R-1, made by eentec) and three components of translational motions recorded by a traditional seismometer (STS-2) at the NACB station in Taiwan. The consistent observations in waveforms of rotational motions and translational motions in sections of Rayleigh and Love waves are presented in reference to the analytical solution for these waves in a half space of Poisson solid. We show that additional information (e.g., Rayleigh wave phase velocity, shear wave velocity of the surface layer) might be exploited from six degree-of-freedom recordings of teleseismic events at only one station. We also find significant errors in the translational records of these teleseismic surface waves due to the sensitivity of inertial translation sensors (seismometers) to rotational motions. The result suggests that the effects of such errors need to be counted in surface wave inversions commonly used to derive earthquake source parameters and Earth structure.

Game Theory in Fleet Management

NASA Astrophysics Data System (ADS)

Dulai, Tibor; Jaskó, Szilárd; Muhi, Dániel

2008-11-01

In this survey we attempt to apply the results of cooperative game theory on fleet management problems. We deal with the aspect of a fleet where the members have their own goal, however the fleet has a common purpose too. These goals are to reach all destinations and get back to the center as quickly as possible. If we draw the map of the area-which contains the destination points and their environment-as a graph, we should determinate circles in it for each member of the fleet. Separating the nodes for each member, we should find Hamilton-circles of the sub-graphs. How to separate the destination points between the fleet members? How to route the members? What happens if there is an accident on a road which changes the way of a member? It may influence the other members' route too. What to communicate for getting the relevant information? How to change the routes in real time? We use cooperative game theory to find the solution.

[Study of pretreatment on microfiltration of huanglian jiedu decoction with ceramic membranes based on solution environment regulation theory].

PubMed

Li, Bo; Zhang, Lian-Jun; Guo, Li-Wei; Fu, Ting-Ming; Zhu, Hua-Xu

2014-01-01

To optimize the pretreatment of Huanglian Jiedu decoction before ceramic membranes and verify the effect of different pretreatments in multiple model system existed in Chinese herb aqueous extract. The solution environment of Huanglian Jiedu decoction was adjusted by different pretreatments. The flux of microfiltration, transmittance of the ingredients and removal rate of common polymers were as indicators to study the effect of different solution environment It was found that flocculation had higher stable permeate flux, followed by vacuuming filtration and adjusting pH to 9. The removal rate of common polymers was comparatively high. The removal rate of protein was slightly lower than the simulated solution. The transmittance of index components were higher when adjust pH and flocculation. Membrane blocking resistance was the major factor in membrane fouling. Based on the above indicators, the effect of flocculation was comparatively significant, followed by adjusting pH to 9.

Formulation and Stability of Solutions.

PubMed

Akers, Michael J

2016-01-01

Ready-to-use solutions are the most preferable and most common dosage forms for injectable and topical ophthalmic products. Drugs formulated as solution almost always have chemical and physical stability challenges as well as solubility limitations and the need to prevent inadvertent microbial contamination issues. This article, which takes us through a discussion of optimizing the physical stability of solutions, represents the first of a series of articles discussing how these challenges and issues are addressed.

Solving Single Machine Total Weighted Tardiness Problem with Unequal Release Date Using Neurohybrid Particle Swarm Optimization Approach.

PubMed

Cakar, Tarik; Koker, Rasit

2015-01-01

A particle swarm optimization algorithm (PSO) has been used to solve the single machine total weighted tardiness problem (SMTWT) with unequal release date. To find the best solutions three different solution approaches have been used. To prepare subhybrid solution system, genetic algorithms (GA) and simulated annealing (SA) have been used. In the subhybrid system (GA and SA), GA obtains a solution in any stage, that solution is taken by SA and used as an initial solution. When SA finds better solution than this solution, it stops working and gives this solution to GA again. After GA finishes working the obtained solution is given to PSO. PSO searches for better solution than this solution. Later it again sends the obtained solution to GA. Three different solution systems worked together. Neurohybrid system uses PSO as the main optimizer and SA and GA have been used as local search tools. For each stage, local optimizers are used to perform exploitation to the best particle. In addition to local search tools, neurodominance rule (NDR) has been used to improve performance of last solution of hybrid-PSO system. NDR checked sequential jobs according to total weighted tardiness factor. All system is named as neurohybrid-PSO solution system.

[Speculations regarding electric conductivity, the development of an electron theory of metals and the beginning of solid body physics].

PubMed

Wiederkehr, Karl Heinrich

2010-01-01

The development of an electron-theory of metals is closely connected with early speculation in the period before Maxwell (W Weber and others) regarding electrical conductivity in metals. These Speculations were in contrast with Faraday's view of an all-embracing molecular dielectric polarisation, and a subsequent passage of charges in metallic conductors. In terms of the empirical law of Wiedemann-Franz-Lorenz, the conductivity of electricity and heat had to be treated commonly. The classical electron-theory of metals (Riecke, Drude, H.A. Lorentz) reached a dead end on account of problems concerned with specific heat capacity. Sommerfeld, by means of the Quantum theory and the Fermi-Statistic, could find the solution.

Neuroscience: viable applications in education?

PubMed

Devonshire, Ian M; Dommett, Eleanor J

2010-08-01

As a relatively young science, neuroscience is still finding its feet in potential collaborations with other disciplines. One such discipline is education, with the field of neuroeducation being on the horizon since the 1960s. However, although its achievements are now growing, the partnership has not been as successful as first hopes suggested it should be. Here the authors discuss the theoretical barriers and potential solutions to this, which have been suggested previously, with particular focus on levels of research in neuroscience and their applicability to education. Moreover, they propose that these theoretical barriers are driven and maintained by practical barriers surrounding common language and research literacy. They propose that by overcoming these practical barriers through appropriate training and shared experience, neuroeducation can reach its full potential.

Exploring Challenges in Developing a Smart and Effective Assistive System for Improving the Experience of the Elderly Drivers

NASA Astrophysics Data System (ADS)

Jung, Sebin; Meng, Hong-Ying; Qin, Sheng-Feng

2017-09-01

As the overall population ages, driving-related accidents and injuries, associated with elderly drivers, have risen. Existing research about elderly drivers mainly focuses on factual data collection and analysis, indicating the elderly's growing fatal accident rates and their different behaviours compared to younger drivers. However, few research has focused on design-led practical solutions to mitigate the elderly's growing fatal accidents, by considering their usability and body conditions, afflicting the elderly, such as decreased vision, hearing, and reaction times. In this paper, first, current worldwide situations on growing fatal accident rates for elderly drivers is reviewed and the key impact factors are identified and discussed with regarding to usability and design trend in the automotive technology for elderly. Second, existing smart vehicle technology-based solutions to promote safe driving are explored and their pros and cons are discussed and analysed. Most of solutions are not created by people with driving difficulties, which are caused by health problems most commonly afflicting the elderly. Thirdly, diverse design-led research activities are taken, such as a survey, observation, and interviews to gain new understanding of what kinds of driving problems elderly drivers have and demonstrate how new system concepts could be developed for the elderly's benefits. Finally, it is found that the elderly's low vision and late reaction are main factors causing their driving difficulties. Based on this finding, usable vehicle system design ideas have been proposed, by utilising facial expression sensing technology as a solution. The proposed solutions would ensure reducing both the elderly's driving problems and high fatal accident rates and provide a more enjoyable driving environment for the elderly population.

Linking attentional processes and conceptual problem solving: visual cues facilitate the automaticity of extracting relevant information from diagrams

PubMed Central

Rouinfar, Amy; Agra, Elise; Larson, Adam M.; Rebello, N. Sanjay; Loschky, Lester C.

2014-01-01

This study investigated links between visual attention processes and conceptual problem solving. This was done by overlaying visual cues on conceptual physics problem diagrams to direct participants’ attention to relevant areas to facilitate problem solving. Participants (N = 80) individually worked through four problem sets, each containing a diagram, while their eye movements were recorded. Each diagram contained regions that were relevant to solving the problem correctly and separate regions related to common incorrect responses. Problem sets contained an initial problem, six isomorphic training problems, and a transfer problem. The cued condition saw visual cues overlaid on the training problems. Participants’ verbal responses were used to determine their accuracy. This study produced two major findings. First, short duration visual cues which draw attention to solution-relevant information and aid in the organizing and integrating of it, facilitate both immediate problem solving and generalization of that ability to new problems. Thus, visual cues can facilitate re-representing a problem and overcoming impasse, enabling a correct solution. Importantly, these cueing effects on problem solving did not involve the solvers’ attention necessarily embodying the solution to the problem, but were instead caused by solvers attending to and integrating relevant information in the problems into a solution path. Second, this study demonstrates that when such cues are used across multiple problems, solvers can automatize the extraction of problem-relevant information extraction. These results suggest that low-level attentional selection processes provide a necessary gateway for relevant information to be used in problem solving, but are generally not sufficient for correct problem solving. Instead, factors that lead a solver to an impasse and to organize and integrate problem information also greatly facilitate arriving at correct solutions. PMID:25324804

Linking attentional processes and conceptual problem solving: visual cues facilitate the automaticity of extracting relevant information from diagrams.

PubMed

Rouinfar, Amy; Agra, Elise; Larson, Adam M; Rebello, N Sanjay; Loschky, Lester C

2014-01-01

This study investigated links between visual attention processes and conceptual problem solving. This was done by overlaying visual cues on conceptual physics problem diagrams to direct participants' attention to relevant areas to facilitate problem solving. Participants (N = 80) individually worked through four problem sets, each containing a diagram, while their eye movements were recorded. Each diagram contained regions that were relevant to solving the problem correctly and separate regions related to common incorrect responses. Problem sets contained an initial problem, six isomorphic training problems, and a transfer problem. The cued condition saw visual cues overlaid on the training problems. Participants' verbal responses were used to determine their accuracy. This study produced two major findings. First, short duration visual cues which draw attention to solution-relevant information and aid in the organizing and integrating of it, facilitate both immediate problem solving and generalization of that ability to new problems. Thus, visual cues can facilitate re-representing a problem and overcoming impasse, enabling a correct solution. Importantly, these cueing effects on problem solving did not involve the solvers' attention necessarily embodying the solution to the problem, but were instead caused by solvers attending to and integrating relevant information in the problems into a solution path. Second, this study demonstrates that when such cues are used across multiple problems, solvers can automatize the extraction of problem-relevant information extraction. These results suggest that low-level attentional selection processes provide a necessary gateway for relevant information to be used in problem solving, but are generally not sufficient for correct problem solving. Instead, factors that lead a solver to an impasse and to organize and integrate problem information also greatly facilitate arriving at correct solutions.

Using solution-focused communication to support patients.

PubMed

Smith, Steve; Adam, Dorothy; Kirkpatrick, Pamela; McRobie, Gillian

Nurses want to help patients; it is one of their main roles and a key source of job satisfaction. However, finding the time despite low staffing levels and a heavy workload is a constant challenge. This article provides an overview of solution-focused communication -an approach valued by an increasing number of nurses because of its brevity and effectiveness in empowering patients to find the solutions that will help them to deal with their health challenges.

Optimal correction and design parameter search by modern methods of rigorous global optimization

NASA Astrophysics Data System (ADS)

Makino, K.; Berz, M.

2011-07-01

Frequently the design of schemes for correction of aberrations or the determination of possible operating ranges for beamlines and cells in synchrotrons exhibit multitudes of possibilities for their correction, usually appearing in disconnected regions of parameter space which cannot be directly qualified by analytical means. In such cases, frequently an abundance of optimization runs are carried out, each of which determines a local minimum depending on the specific chosen initial conditions. Practical solutions are then obtained through an often extended interplay of experienced manual adjustment of certain suitable parameters and local searches by varying other parameters. However, in a formal sense this problem can be viewed as a global optimization problem, i.e. the determination of all solutions within a certain range of parameters that lead to a specific optimum. For example, it may be of interest to find all possible settings of multiple quadrupoles that can achieve imaging; or to find ahead of time all possible settings that achieve a particular tune; or to find all possible manners to adjust nonlinear parameters to achieve correction of high order aberrations. These tasks can easily be phrased in terms of such an optimization problem; but while mathematically this formulation is often straightforward, it has been common belief that it is of limited practical value since the resulting optimization problem cannot usually be solved. However, recent significant advances in modern methods of rigorous global optimization make these methods feasible for optics design for the first time. The key ideas of the method lie in an interplay of rigorous local underestimators of the objective functions, and by using the underestimators to rigorously iteratively eliminate regions that lie above already known upper bounds of the minima, in what is commonly known as a branch-and-bound approach. Recent enhancements of the Differential Algebraic methods used in particle optics for the computation of aberrations allow the determination of particularly sharp underestimators for large regions. As a consequence, the subsequent progressive pruning of the allowed search space as part of the optimization progresses is carried out particularly effectively. The end result is the rigorous determination of the single or multiple optimal solutions of the parameter optimization, regardless of their location, their number, and the starting values of optimization. The methods are particularly powerful if executed in interplay with genetic optimizers generating their new populations within the currently active unpruned space. Their current best guess provides rigorous upper bounds of the minima, which can then beneficially be used for better pruning. Examples of the method and its performance will be presented, including the determination of all operating points of desired tunes or chromaticities, etc. in storage ring lattices.

Kinks in higher derivative scalar field theory

NASA Astrophysics Data System (ADS)

Zhong, Yuan; Guo, Rong-Zhen; Fu, Chun-E.; Liu, Yu-Xiao

2018-07-01

We study static kink configurations in a type of two-dimensional higher derivative scalar field theory whose Lagrangian contains second-order derivative terms of the field. The linear fluctuation around arbitrary static kink solutions is analyzed. We find that, the linear spectrum can be described by a supersymmetric quantum mechanics problem, and the criteria for stable static solutions can be given analytically. We also construct a superpotential formalism for finding analytical static kink solutions. Using this formalism we first reproduce some existed solutions and then offer a new solution. The properties of our solution is studied and compared with those preexisted. We also show the possibility in constructing twinlike model in the higher derivative theory, and give the consistency conditions for twinlike models corresponding to the canonical scalar field theory.

Ethics and transparent risk communication start with proper risk assessment methodologies

NASA Astrophysics Data System (ADS)

Oboni, Franco; Oboni, Cesar

2014-05-01

We will use throught this paper a "dialogue" between two professionals. One is aware of the misleading character of many risk assessments and wants to foster better approaches. A discomforting set of statements sets the background of the "story": public reactions to risk assessments are generally negative, the developer find it difficult to understand the reasons for general public negative reactions, many projects get often rejected without valid reasons by the public, anywhere in the world. Common practice approaches in Risk Assessment are discussed from the angle of public rejection, taking into account various studies that explicitly expose common practices limitations and voids. The hiatus between rational and well-balanced risk assessments and common practices is explored. Finally solutions to overcome the limitations of common practices and deliver to the public more realistic risk assessment on which to build a widespread consensus are reviewed. The paper conclusions relate to the need of: properly communicating risk throughout the life of a project, from cradle to grave, avoiding conflict of interest, having estimates that are understandable to foster good understanding of what a risk assessment can bring to better Human existence, in an ethical and fair way. The paper delivers a list of possible remedies and shows that "Common Practices" do not equate to "Best Practices": common practices are not to be proposed/used any longer if we want to avoid public distrust and misrepresentations. Many of the "modern" issues ranging from public distrust to insurance denial could be relieved or mitigated ahead of time if misrepresentation was kept at bay using five simple rules. Common practice Risk Assessments, especially those developed under conflict of interest situations, generally misrepresent risks and fail to give the "big picture", hence do not help taking valid decision and are prone to generating/fostering public distrust.

Novel third-order Lovelock wormhole solutions

NASA Astrophysics Data System (ADS)

Mehdizadeh, Mohammad Reza; Lobo, Francisco S. N.

2016-06-01

In this work, we consider wormhole geometries in third-order Lovelock gravity and investigate the possibility that these solutions satisfy the energy conditions. In this framework, by applying a specific equation of state, we obtain exact wormhole solutions, and by imposing suitable values for the parameters of the theory, we find that these geometries satisfy the weak energy condition in the vicinity of the throat, due to the presence of higher-order curvature terms. Finally, we trace out a numerical analysis, by assuming a specific redshift function, and find asymptotically flat solutions that satisfy the weak energy condition throughout the spacetime.

Radiating black hole solutions in Einstein-Gauss-Bonnet gravity

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

Dominguez, Alfredo E.; Instituto Universitario Aeronautico, Avenida Fuerza Aerea km 6.5.; Gallo, Emanuel

2006-03-15

In this paper, we find some new exact solutions to the Einstein-Gauss-Bonnet equations. First, we prove a theorem which allows us to find a large family of solutions to the Einstein-Gauss-Bonnet gravity in n-dimensions. This family of solutions represents dynamic black holes and contains, as particular cases, not only the recently found Vaidya-Einstein-Gauss-Bonnet black hole, but also other physical solutions that we think are new, such as the Gauss-Bonnet versions of the Bonnor-Vaidya (de Sitter/anti-de Sitter) solution, a global monopole, and the Husain black holes. We also present a more general version of this theorem in which less restrictive conditionsmore » on the energy-momentum tensor are imposed. As an application of this theorem, we present the exact solution describing a black hole radiating a charged null fluid in a Born-Infeld nonlinear electrodynamics.« less

Black holes in a cubic Galileon universe

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

Babichev, E.; Charmousis, C.; Lehébel, A.

2016-09-01

We find and study the properties of black hole solutions for a subclass of Horndeski theory including the cubic Galileon term. The theory under study has shift symmetry but not reflection symmetry for the scalar field. The Galileon is assumed to have linear time dependence characterized by a velocity parameter. We give analytic 3-dimensional solutions that are akin to the BTZ solutions but with a non-trivial scalar field that modifies the effective cosmological constant. We then study the 4-dimensional asymptotically flat and de Sitter solutions. The latter present three different branches according to their effective cosmological constant. For two ofmore » these branches, we find families of black hole solutions, parametrized by the velocity of the scalar field. These spherically symmetric solutions, obtained numerically, are different from GR solutions close to the black hole event horizon, while they have the same de-Sitter asymptotic behavior. The velocity parameter represents black hole primary hair.« less

Asymptotically flat black holes in Horndeski theory and beyond

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

Babichev, E.; Charmousis, C.; Lehébel, A., E-mail: eugeny.babichev@th.u-psud.fr, E-mail: christos.charmousis@th.u-psud.fr, E-mail: antoine.lehebel@th.u-psud.fr

We find spherically symmetric and static black holes in shift-symmetric Horndeski and beyond Horndeski theories. They are asymptotically flat and sourced by a non trivial static scalar field. The first class of solutions is constructed in such a way that the Noether current associated with shift symmetry vanishes, while the scalar field cannot be trivial. This in certain cases leads to hairy black hole solutions (for the quartic Horndeski Lagrangian), and in others to singular solutions (for a Gauss-Bonnet term). Additionally, we find the general spherically symmetric and static solutions for a pure quartic Lagrangian, the metric of which ismore » Schwarzschild. We show that under two requirements on the theory in question, any vacuum GR solution is also solution to the quartic theory. As an example, we show that a Kerr black hole with a non-trivial scalar field is an exact solution to these theories.« less

Causal gene identification using combinatorial V-structure search.

PubMed

Cai, Ruichu; Zhang, Zhenjie; Hao, Zhifeng

2013-07-01

With the advances of biomedical techniques in the last decade, the costs of human genomic sequencing and genomic activity monitoring are coming down rapidly. To support the huge genome-based business in the near future, researchers are eager to find killer applications based on human genome information. Causal gene identification is one of the most promising applications, which may help the potential patients to estimate the risk of certain genetic diseases and locate the target gene for further genetic therapy. Unfortunately, existing pattern recognition techniques, such as Bayesian networks, cannot be directly applied to find the accurate causal relationship between genes and diseases. This is mainly due to the insufficient number of samples and the extremely high dimensionality of the gene space. In this paper, we present the first practical solution to causal gene identification, utilizing a new combinatorial formulation over V-Structures commonly used in conventional Bayesian networks, by exploring the combinations of significant V-Structures. We prove the NP-hardness of the combinatorial search problem under a general settings on the significance measure on the V-Structures, and present a greedy algorithm to find sub-optimal results. Extensive experiments show that our proposal is both scalable and effective, particularly with interesting findings on the causal genes over real human genome data. Copyright © 2013 Elsevier Ltd. All rights reserved.

Separation of Undersampled Composite Signals Using the Dantzig Selector with Overcomplete Dictionaries

DTIC Science & Technology

2014-06-02

2011). [22] Li, Q., Micchelli, C., Shen, L., and Xu, Y. A proximity algorithm acelerated by Gauss - Seidel iterations for L1/TV denoising models. Inverse...system of equations and their relationship to the solution of Model (2) and present an algorithm with an iterative approach for finding these solutions...Using the fixed-point characterization above, the (k + 1)th iteration of the prox- imity operator algorithm to find the solution of the Dantzig

Dimensionality of Community Satisfaction.

ERIC Educational Resources Information Center

Williams, R. Gary; Knop, Edward

Using factor analysis (both principal factor solutions and rotated factor solutions) to search for underlying statistical commonality among 12 indicators of community satisfaction in 6 Colorado communities, the research explores various dimensions of community satisfaction that may be important across different communities. The communities under…

Graphical Solution of Polynomial Equations

ERIC Educational Resources Information Center

Grishin, Anatole

2009-01-01

Graphing utilities, such as the ubiquitous graphing calculator, are often used in finding the approximate real roots of polynomial equations. In this paper the author offers a simple graphing technique that allows one to find all solutions of a polynomial equation (1) of arbitrary degree; (2) with real or complex coefficients; and (3) possessing…

Finding Strategic Solutions to Reduce Truancy

ERIC Educational Resources Information Center

Reid, Ken

2010-01-01

This article focuses on recent developments to find strategic solutions to the problem of truancy. It considers issues related to defining truancy and why reducing truancy matters before considering what causes truancy. The article concentrates upon seven areas where further work is needed: the role of parents (and carers); early intervention,…

[Survey on drug-related problems in Lithuania's pharmacies].

PubMed

Kubiliene, Loreta; Liukenskyte, Simona; Savickas, Arūnas; Jureniene, Kristina

2006-01-01

to survey the most common and the most important drug-related problems in Lithuania, to explore their solution and factors influencing it, to formulate recommendations for solving drug-related problems. Pharmacists from community pharmacies participated in a random survey. They filled in questionnaires about drug-related problems and their solutions. It was the first survey on drug-related problems ever carried out in Lithuania. For the first time, it was found out that in Lithuania pharmacists most commonly encountered drug-related problem--additional drug therapy (52.03% of respondents)--and most rarely encountered drug-related problem--dosage too high (3% of respondents). Pharmacists stated that all categories of drug-related problems were of equal importance. It was established that pharmacists commonly solved drug-related problems associated with noncompliance with instructions (72.5% of respondents) and rarely met the problem when improper drug was selected (39.56% of respondents). Patients taking prescription medicines commonly encounter additional drug therapy problem, and patients taking nonprescription medications commonly encounter problems related to noncompliance with instructions.

Technology in rural transportation: "Simple Solutions"

DOT National Transportation Integrated Search

1997-10-01

The Rural Outreach Project: Simple Solutions Report contains the findings of a research effort aimed at identifying and describing proven, cost-effective, low-tech solutions for rural transportation-related problems or needs. Through a process ...

Childhood Obesity & Dental Disease: Common Causes, Common Solutions. Oral Health & Obesity Policy Brief

ERIC Educational Resources Information Center

Children Now, 2011

2011-01-01

Too many California children suffer from high rates of preventable chronic conditions associated with childhood obesity and dental disease. The state is experiencing a crisis in both areas. Fortunately, common factors that contribute to both conditions--including the rates of breastfeeding, access to healthy food and the consumption of…

Spontaneous and Flow-Driven Interfacial Phase Change: Dynamics of Microemulsion Formation at the Pore Scale.

PubMed

Tagavifar, Mohsen; Xu, Ke; Jang, Sung Hyun; Balhoff, Matthew T; Pope, Gary A

2017-11-14

The dynamic behavior of microemulsion-forming water-oil-amphiphiles mixtures is investigated in a 2.5D micromodel. The equilibrium phase behavior of such mixtures is well-understood in terms of macroscopic phase transitions. However, what is less understood and where experimental data are lacking is the coupling between the phase change and the bulk flow. Herein, we study the flow of an aqueous surfactant solution-oil mixture in porous media and analyze the dependence of phase formation and spatial phase configurations on the bulk flow rate. We find that a microemulsion forms instantaneously as a boundary layer at the initial surface of contact between the surfactant solution and oil. The boundary layer is temporally continuous because of the imposed convection. In addition to the imposed flow, we observe spontaneous pulsed Marangoni flows that drag the microemulsion and surfactant solution into the oil stream, forming large (macro)emulsion droplets. The formation of the microemulsion phase at the interface distinguishes the situation from that of the more common Marangoni flow with only two phases present. Additionally, an emulsion forms via liquid-liquid nucleation or the Ouzo effect (i.e., spontaneous emulsification) at low flow rates and via mechanical mixing at high flow rates. With regard to multiphase flow, contrary to the common belief that the microemulsion is the wetting liquid, we observe that the minor oil phase wets the solid surface. We show that a layered flow pattern is formed because of the out-of-equilibrium phase behavior at high volumetric flow rates (order of 2 m/day) where advection is much faster than the diffusive interfacial mass transfer and transverse mixing, which promote equilibrium behavior. At lower flow rates (order of 30 cm/day), however, the dynamic and equilibrium phase behaviors are well-correlated. These results clearly show that the phase change influences the macroscale flow behavior.

76 FR 69146 - Common or Usual Name for Raw Meat and Poultry Products Containing Added Solutions-Reopening of...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-08

.... FSIS-2010-0012] RIN 0583-AD41 Common or Usual Name for Raw Meat and Poultry Products Containing Added... for 60 days the comment period for the proposed rule, ``Common or Usual Name for Raw Meat and Poultry..., FSIS published the proposed rule ``Common or Usual Name for Raw Meat and Poultry Products Containing...

Summary of Data from the Sixth AIAA CFD Drag Prediction Workshop: CRM Cases 2 to 5

NASA Technical Reports Server (NTRS)

Tinoco, Edward N.; Brodersen, Olaf P.; Keye, Stefan; Laflin, Kelly R.; Feltrop, Edward; Vassberg, John C.; Mani, Mori; Rider, Ben; Wahls, Richard A.; Morrison, Joseph H.;

Langevin synchronization in a time-dependent, harmonic basin: An exact solution in 1D

NASA Astrophysics Data System (ADS)

Cadilhe, A.; Voter, Arthur F.

2018-02-01

The trajectories of two particles undergoing Langevin dynamics while sharing a common noise sequence can merge into a single (master) trajectory. Here, we present an exact solution for a particle undergoing Langevin dynamics in a harmonic, time-dependent potential, thus extending the idea of synchronization to nonequilibrium systems. We calculate the synchronization level, i.e., the mismatch between two trajectories sharing a common noise sequence, in the underdamped, critically damped, and overdamped regimes. Finally, we provide asymptotic expansions in various limiting cases and compare to the time independent case.

Study of analytical method to seek for exact solutions of variant Boussinesq equations.

PubMed

Khan, Kamruzzaman; Akbar, M Ali

2014-01-01

In this paper, we have been acquired the soliton solutions of the Variant Boussinesq equations. Primarily, we have used the enhanced (G'/G)-expansion method to find exact solutions of Variant Boussinesq equations. Then, we attain some exact solutions including soliton solutions, hyperbolic and trigonometric function solutions of this equation. 35 K99; 35P05; 35P99.

Electromagnetic-radiation absorption by water.

PubMed

Lunkenheimer, P; Emmert, S; Gulich, R; Köhler, M; Wolf, M; Schwab, M; Loidl, A

2017-12-01

Why does a microwave oven work? How does biological tissue absorb electromagnetic radiation? Astonishingly, we do not have a definite answer to these simple questions because the microscopic processes governing the absorption of electromagnetic waves by water are largely unclarified. This absorption can be quantified by dielectric loss spectra, which reveal a huge peak at a frequency of the exciting electric field of about 20 GHz and a gradual tailing off toward higher frequencies. The microscopic interpretation of such spectra is highly controversial and various superpositions of relaxation and resonance processes ascribed to single-molecule or molecule-cluster motions have been proposed for their analysis. By combining dielectric, microwave, THz, and far-infrared spectroscopy, here we provide nearly continuous temperature-dependent broadband spectra of water. Moreover, we find that corresponding spectra for aqueous solutions reveal the same features as pure water. However, in contrast to the latter, crystallization in these solutions can be avoided by supercooling. As different spectral contributions tend to disentangle at low temperatures, this enables us to deconvolute them when approaching the glass transition under cooling. We find that the overall spectral development, including the 20 GHz feature (employed for microwave heating), closely resembles the behavior known for common supercooled liquids. Thus water's absorption of electromagnetic waves at room temperature is not unusual but very similar to that of glass-forming liquids at elevated temperatures, deep in the low-viscosity liquid regime, and should be interpreted along similar lines.

Challenges on Java’s small city spatial planning

NASA Astrophysics Data System (ADS)

Wirawan, B.; Tambunan, J. R.

2018-05-01

Most Indonesians nowadays live in the urban area, due to urbanization. 60 percent of the inhabitants of Java, the most populous island in Indonesia, will live in the urban area by 2010, a figure that is higher than the national average of 55 percent. Urbanization has brought a large influx of newcomers not only into the metropolitan or large cities, but also into small and medium cities. One of urbanization’s most concerning impacts is urban sprawl that harms sustainability. There is a dearth of academic literature studying the phenomenon of urban sprawl in Indonesian small cities. Urban sprawl in small cities is commonly ignored, considered as a contained problem the solution for which is a simple use of local spatial plan. Unfortunately, for Indonesia, this solution is difficult to implement because city spatial plans works only within administrative jurisdictions, whilst the urban sprawls themselves generally occur across the borders of different administrative jurisdictions. This study studies urban sprawls occurring in several small cities in Java. While those cities already have spatial plan, most were the general spatial plan (Rencana Tata Ruang Wilayah Kota/Kabupaten) that operates only within the city’s administrative jurisdiction. We are unable to find detailed strategies in these cities to deal with urban sprawl. We also found that all spatial plans are unable to come up with urban growth boundary strategy. Finally, we are also unable to find integrated detailed spatial plan among those cities to answer the urban sprawl situation.

Optimal simultaneous superpositioning of multiple structures with missing data

PubMed Central

Theobald, Douglas L.; Steindel, Phillip A.

2012-01-01

Motivation: Superpositioning is an essential technique in structural biology that facilitates the comparison and analysis of conformational differences among topologically similar structures. Performing a superposition requires a one-to-one correspondence, or alignment, of the point sets in the different structures. However, in practice, some points are usually ‘missing’ from several structures, for example, when the alignment contains gaps. Current superposition methods deal with missing data simply by superpositioning a subset of points that are shared among all the structures. This practice is inefficient, as it ignores important data, and it fails to satisfy the common least-squares criterion. In the extreme, disregarding missing positions prohibits the calculation of a superposition altogether. Results: Here, we present a general solution for determining an optimal superposition when some of the data are missing. We use the expectation–maximization algorithm, a classic statistical technique for dealing with incomplete data, to find both maximum-likelihood solutions and the optimal least-squares solution as a special case. Availability and implementation: The methods presented here are implemented in THESEUS 2.0, a program for superpositioning macromolecular structures. ANSI C source code and selected compiled binaries for various computing platforms are freely available under the GNU open source license from http://www.theseus3d.org. Contact: dtheobald@brandeis.edu Supplementary information: Supplementary data are available at Bioinformatics online. PMID:22543369

Ab initio assessment of Bi1-xRExCuOS (RE = La, Gd, Y, Lu) solid solutions as a semiconductor for photochemical water splitting.

PubMed

Lardhi, Sheikha; Curutchet, Antton; Cavallo, Luigi; Harb, Moussab; Le Bahers, Tangui

2017-05-17

The investigation of the BiCuOCh (Ch = S, Se and Te) semiconductor family for thermoelectric or photovoltaic materials is a topic of increasing research interest. These materials can also be considered for photochemical water splitting if one representative having a bandgap, E g , at around 2 eV can be developed. With this aim, we simulated the solid solutions Bi 1-x RE x CuOS (RE = Y, La, Gd and Lu) from pure BiCuOS (E g ∼ 1.1 eV) to pure RECuOS compositions (E g ∼ 2.9 eV) by DFT calculations based on the HSE06 range-separated hybrid functional with the inclusion of spin-orbit coupling. Starting from the thermodynamic stability of the solid solution, several properties were computed for each system including bandgaps, dielectric constants, effective masses and exciton binding energies. We discussed the variation of these properties based on the relative organization of Bi and RE atoms in their common sublattice to offer a physical understanding of the influence of the RE doping of BiCuOS. Some compositions were found to give appropriate properties for water splitting applications. Furthermore, we found that at low RE fractions the transport properties of BiCuOS are improved that can find applications beyond water splitting.

Structural equation modeling for observational studies

USGS Publications Warehouse

Grace, J.B.

2008-01-01

Structural equation modeling (SEM) represents a framework for developing and evaluating complex hypotheses about systems. This method of data analysis differs from conventional univariate and multivariate approaches familiar to most biologists in several ways. First, SEMs are multiequational and capable of representing a wide array of complex hypotheses about how system components interrelate. Second, models are typically developed based on theoretical knowledge and designed to represent competing hypotheses about the processes responsible for data structure. Third, SEM is conceptually based on the analysis of covariance relations. Most commonly, solutions are obtained using maximum-likelihood solution procedures, although a variety of solution procedures are used, including Bayesian estimation. Numerous extensions give SEM a very high degree of flexibility in dealing with nonnormal data, categorical responses, latent variables, hierarchical structure, multigroup comparisons, nonlinearities, and other complicating factors. Structural equation modeling allows researchers to address a variety of questions about systems, such as how different processes work in concert, how the influences of perturbations cascade through systems, and about the relative importance of different influences. I present 2 example applications of SEM, one involving interactions among lynx (Lynx pardinus), mongooses (Herpestes ichneumon), and rabbits (Oryctolagus cuniculus), and the second involving anuran species richness. Many wildlife ecologists may find SEM useful for understanding how populations function within their environments. Along with the capability of the methodology comes a need for care in the proper application of SEM.

Role of orthophosphate as a corrosion inhibitor in chloraminated solutions containing tetravalent lead corrosion product PbO2.

PubMed

Ng, Ding-Quan; Strathmann, Timothy J; Lin, Yi-Pin

2012-10-16

Addition of orthophosphate has been commonly employed to suppress lead levels in drinking water. Its detailed mechanism and time required for it to become effective, however, have not been fully elucidated. In this study, we investigated the mechanistic role of orthophosphate as a corrosion inhibitor in controlling lead release from tetravalent lead corrosion product PbO(2) in chloraminated solutions, a system representing distribution networks experiencing disinfectant changeover from free chlorine to monochloramine. In all experiments with orthophosphate addition of at least 1 mg/L as P, peaking of soluble Pb(II) concentration within the first 24 h was observed before lead concentrations decreased and stabilized at levels lower than 15 μg/L. The variation of soluble Pb(II) concentration could be attributed to the dynamics between the rate of PbO(2) reductive dissolution, primarily induced by monochloramine decomposition, and that of chloropyromorphite (Pb(5)(PO(4))(3)Cl) precipitation, which did not occur until a critical supersaturation ratio of about 2.36 was reached in the solution. Our findings provide insights to how orthophosphate reduces lead levels under drinking water conditions and highlight the potential risk of short-term elevated lead concentrations. Intensive monitoring following the disinfectant changeover may be required to determine the overall lead exposure when using orthophosphate as a corrosion inhibitor.

Current Trends in Wireless Mesh Sensor Networks: A Review of Competing Approaches

PubMed Central

Rodenas-Herraiz, David; Garcia-Sanchez, Antonio-Javier; Garcia-Sanchez, Felipe; Garcia-Haro, Joan

2013-01-01

Finding a complete mesh-based solution for low-rate wireless personal area networks (LR-WPANs) is still an open issue. To cope with this concern, different competing approaches have emerged in the Wireless Mesh Sensor Networks (WMSNs) field in the last few years. They are usually supported by the IEEE 802.15.4 standard, the most commonly adopted LR-WPAN recommendation for point-to-point topologies. In this work, we review the most relevant and up-to-date WMSN solutions that extend the IEEE 802.15.4 standard to multi-hop mesh networks. To conduct this review, we start by identifying the most significant WMSN requirements (i.e., interoperability, robustness, scalability, mobility or energy-efficiency) that reveal the benefits and shortcomings of each proposal. Then, we re-examine thoroughly the group of proposals following different design guidelines which are usually considered by end-users and developers. Among all of the approaches reviewed, we highlight the IEEE 802.15.5 standard, a recent recommendation that, in its LR-WPAN version, fully satisfies the greatest number of WMSN requirements. As a result, IEEE 802.15.5 can be an appropriate solution for a wide-range of applications, unlike the majority of the remaining solutions reviewed, which are usually designed to solve particular problems, for instance in the home, building and industrial sectors. In this sense, a description of IEEE 802.15.5 is also included, paying special attention to its efficient energy-saving mechanisms. Finally, possible improvements of this recommendation are pointed out in order to offer hints for future research. PMID:23666128

NMR studies of proton exchange kinetics in aqueous formaldehyde solutions.

PubMed

Rivlin, Michal; Eliav, Uzi; Navon, Gil

2014-05-01

Aqueous solutions of formaldehyde, formalin, are commonly used for tissue fixation and preservation. Treatment with formalin is known to shorten the tissue transverse relaxation time T2. Part of this shortening is due to the effect of formalin on the water T2. In the present work we show that the shortening of water T2 is a result of proton exchange between water and the major constituent of aqueous solutions of formaldehyde, methylene glycol. We report the observation of the signal of the hydroxyl protons of methylene glycol at 2ppm to high frequency of the water signal that can be seen at low temperatures and at pH range of 6.0±1.5 and, at conditions where it cannot be observed by the single pulse experiment, it can be detected indirectly through the water signal by the chemical exchange saturation transfer (CEST) experiment. The above finding made it possible to obtain the exchange rate between the hydroxyl protons of the methylene glycol and water in aqueous formaldehyde solutions, either using the dispersion of the spin-lattice relaxation rate in the rotating frame (1/T1ρ) or, at the slow exchange regime, from the line width hydroxyl protons of methylene glycol. The exchange rate was ∼10(4)s(-1) at pH 7.4 and 37°C, the activation energy, 50.2kJ/mol and its pH dependence at 1.1°C was fitted to: k (s(-1))=520+6.5×10(7)[H(+)]+3.0×10(9)[OH(-)]. Copyright © 2014. Published by Elsevier Inc.

A Reconstruction Approach to High-Order Schemes Including Discontinuous Galerkin for Diffusion

NASA Technical Reports Server (NTRS)

Huynh, H. T.

2009-01-01

We introduce a new approach to high-order accuracy for the numerical solution of diffusion problems by solving the equations in differential form using a reconstruction technique. The approach has the advantages of simplicity and economy. It results in several new high-order methods including a simplified version of discontinuous Galerkin (DG). It also leads to new definitions of common value and common gradient quantities at each interface shared by the two adjacent cells. In addition, the new approach clarifies the relations among the various choices of new and existing common quantities. Fourier stability and accuracy analyses are carried out for the resulting schemes. Extensions to the case of quadrilateral meshes are obtained via tensor products. For the two-point boundary value problem (steady state), it is shown that these schemes, which include most popular DG methods, yield exact common interface quantities as well as exact cell average solutions for nearly all cases.

Catalyzing Gender Equality-Focused Clean Energy Development in West Africa

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

The Economic Community of West African States (ECOWAS) Regional Center for Renewable Energy and Energy Efficiency (ECREEE) partnered with the Clean Energy Solutions Center (Solutions Center), the African Development Bank and other institutions to develop a Situation Analysis of Energy and Gender Issues in ECOWAS Member States. Through a systematic approach to assess interlinked gender and energy issues in the region, the report puts forth a number of key findings. This brochure highlights ECREEE's partnership with the Solutions Center and key findings from the report.

The Double Star Orbit Initial Value Problem

NASA Astrophysics Data System (ADS)

Hensley, Hagan

2018-04-01

Many precise algorithms exist to find a best-fit orbital solution for a double star system given a good enough initial value. Desmos is an online graphing calculator tool with extensive capabilities to support animations and defining functions. It can provide a useful visual means of analyzing double star data to arrive at a best guess approximation of the orbital solution. This is a necessary requirement before using a gradient-descent algorithm to find the best-fit orbital solution for a binary system.

Use of 3D vision for fine robot motion

NASA Technical Reports Server (NTRS)

Lokshin, Anatole; Litwin, Todd

1989-01-01

An integration of 3-D vision systems with robot manipulators will allow robots to operate in a poorly structured environment by visually locating targets and obstacles. However, by using computer vision for objects acquisition makes the problem of overall system calibration even more difficult. Indeed, in a CAD based manipulation a control architecture has to find an accurate mapping between the 3-D Euclidean work space and a robot configuration space (joint angles). If a stereo vision is involved, then one needs to map a pair of 2-D video images directly into the robot configuration space. Neural Network approach aside, a common solution to this problem is to calibrate vision and manipulator independently, and then tie them via common mapping into the task space. In other words, both vision and robot refer to some common Absolute Euclidean Coordinate Frame via their individual mappings. This approach has two major difficulties. First a vision system has to be calibrated over the total work space. And second, the absolute frame, which is usually quite arbitrary, has to be the same with a high degree of precision for both robot and vision subsystem calibrations. The use of computer vision to allow robust fine motion manipulation in a poorly structured world which is currently in progress is described along with the preliminary results and encountered problems.

Reflection on solutions in the form of refutation texts versus problem solving: the case of 8th graders studying simple electric circuits

NASA Astrophysics Data System (ADS)

Safadi, Rafi'; Safadi, Ekhlass; Meidav, Meir

2017-01-01

This study compared students’ learning in troubleshooting and problem solving activities. The troubleshooting activities provided students with solutions to conceptual problems in the form of refutation texts; namely, solutions that portray common misconceptions, refute them, and then present the accepted scientific ideas. They required students to individually diagnose these solutions; that is, to identify the erroneous and correct parts of the solutions and explain in what sense they differed, and later share their work in whole class discussions. The problem solving activities required the students to individually solve these same problems, and later share their work in whole class discussions. We compared the impact of the individual work stage in the troubleshooting and problem solving activities on promoting argumentation in the subsequent class discussions, and the effects of these activities on students’ engagement in self-repair processes; namely, in learning processes that allowed the students to self-repair their misconceptions, and by extension on advancing their conceptual knowledge. Two 8th grade classes studying simple electric circuits with the same teacher took part. One class (28 students) carried out four troubleshooting activities and the other (31 students) four problem solving activities. These activities were interwoven into a twelve lesson unit on simple electric circuits that was spread over a period of 2 months. The impact of the troubleshooting activities on students’ conceptual knowledge was significantly higher than that of the problem solving activities. This result is consistent with the finding that the troubleshooting activities engaged students in self-repair processes whereas the problem solving activities did not. The results also indicated that diagnosing solutions to conceptual problems in the form of refutation texts, as opposed to solving these same problems, apparently triggered argumentation in subsequent class discussions, even though the teacher was unfamiliar with the best ways to conduct argumentative classroom discussions. We account for these results and suggest possible directions for future research.

On the Conservation and Convergence to Weak Solutions of Global Schemes

NASA Technical Reports Server (NTRS)

Carpenter, Mark H.; Gottlieb, David; Shu, Chi-Wang

2001-01-01

In this paper we discuss the issue of conservation and convergence to weak solutions of several global schemes, including the commonly used compact schemes and spectral collocation schemes, for solving hyperbolic conservation laws. It is shown that such schemes, if convergent boundedly almost everywhere, will converge to weak solutions. The results are extensions of the classical Lax-Wendroff theorem concerning conservative schemes.

METAL RECOVERY/REMOVAL USING NON-ELECTROLYTIC METAL RECOVERY

EPA Science Inventory

Radiator repair shops most commonly use hot caustic solutions to clean radiator sections prior to resoldering. he hot caustic, or "boil-out" solutions as they are cabled in the trade, become contaminated with dirt, rust flakes, paint flakes and miscellaneous particulate debris. n...

Making pH Tangible.

ERIC Educational Resources Information Center

McIntosh, Elizabeth; Moss, Robert

1995-01-01

Presents a laboratory exercise in which students test the pH of different substances, study the effect of a buffer on acidic solutions by comparing the behavior of buffered and unbuffered solutions upon the addition of acid, and compare common over-the-counter antacid remedies. (MKR)

Deforming baryons into confining strings

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

Hartnoll, Sean A.; Portugues, Ruben

2004-09-15

We find explicit probe D3-brane solutions in the infrared of the Maldacena-Nunez background. The solutions describe deformed baryon vertices: q external quarks are separated in spacetime from the remaining N-q. As the separation is taken to infinity we recover known solutions describing infinite confining strings in N=1 gauge theory. We present results for the mass of finite confining strings as a function of length. We also find probe D2-brane solutions in a confining type IIA geometry, the reduction of a G{sub 2} holonomy M theory background. The relation between these deformed baryons and confining strings is not as straightforward.

A comparison of solute-transport solution techniques based on inverse modelling results

USGS Publications Warehouse

Mehl, S.; Hill, M.C.

2000-01-01

Five common numerical techniques (finite difference, predictor-corrector, total-variation-diminishing, method-of-characteristics, and modified-method-of-characteristics) were tested using simulations of a controlled conservative tracer-test experiment through a heterogeneous, two-dimensional sand tank. The experimental facility was constructed using randomly distributed homogeneous blocks of five sand types. This experimental model provides an outstanding opportunity to compare the solution techniques because of the heterogeneous hydraulic conductivity distribution of known structure, and the availability of detailed measurements with which to compare simulated concentrations. The present work uses this opportunity to investigate how three common types of results-simulated breakthrough curves, sensitivity analysis, and calibrated parameter values-change in this heterogeneous situation, given the different methods of simulating solute transport. The results show that simulated peak concentrations, even at very fine grid spacings, varied because of different amounts of numerical dispersion. Sensitivity analysis results were robust in that they were independent of the solution technique. They revealed extreme correlation between hydraulic conductivity and porosity, and that the breakthrough curve data did not provide enough information about the dispersivities to estimate individual values for the five sands. However, estimated hydraulic conductivity values are significantly influenced by both the large possible variations in model dispersion and the amount of numerical dispersion present in the solution technique.Five common numerical techniques (finite difference, predictor-corrector, total-variation-diminishing, method-of-characteristics, and modified-method-of-characteristics) were tested using simulations of a controlled conservative tracer-test experiment through a heterogeneous, two-dimensional sand tank. The experimental facility was constructed using randomly distributed homogeneous blocks of five sand types. This experimental model provides an outstanding opportunity to compare the solution techniques because of the heterogeneous hydraulic conductivity distribution of known structure, and the availability of detailed measurements with which to compare simulated concentrations. The present work uses this opportunity to investigate how three common types of results - simulated breakthrough curves, sensitivity analysis, and calibrated parameter values - change in this heterogeneous situation, given the different methods of simulating solute transport. The results show that simulated peak concentrations, even at very fine grid spacings, varied because of different amounts of numerical dispersion. Sensitivity analysis results were robust in that they were independent of the solution technique. They revealed extreme correlation between hydraulic conductivity and porosity, and that the breakthrough curve data did not provide enough information about the dispersivities to estimate individual values for the five sands. However, estimated hydraulic conductivity values are significantly influenced by both the large possible variations in model dispersion and the amount of numerical dispersion present in the solution technique.

Lovelock branes

NASA Astrophysics Data System (ADS)

Kastor, David; Ray, Sourya; Traschen, Jennie

2017-10-01

We study the problem of finding brane-like solutions to Lovelock gravity, adopting a general approach to establish conditions that a lower dimensional base metric must satisfy in order that a solution to a given Lovelock theory can be constructed in one higher dimension. We find that for Lovelock theories with generic values of the coupling constants, the Lovelock tensors (higher curvature generalizations of the Einstein tensor) of the base metric must all be proportional to the metric. Hence, allowed base metrics form a subclass of Einstein metrics. This subclass includes so-called ‘universal metrics’, which have been previously investigated as solutions to quantum-corrected field equations. For specially tuned values of the Lovelock couplings, we find that the Lovelock tensors of the base metric need to satisfy fewer constraints. For example, for Lovelock theories with a unique vacuum there is only a single such constraint, a case previously identified in the literature, and brane solutions can be straightforwardly constructed.

Occupational exposure to pesticides and resultant health problems among cotton farmers of Punjab, Pakistan.

PubMed

Khan, Muhammad; Damalas, Christos A

2015-01-01

Occupational exposure to pesticides and resultant health problems were assessed among 318 randomly selected cotton farmers from the two districts of Punjab, Pakistan. Heavy dependence of farmers on pesticides for pest control was reported. A large part (23.3%) of the pesticides belonged to the category highly hazardous, whereas the largest part (54.7%) belonged to the category moderately hazardous. Some of them (8%) were reported to be used on vegetables. Common working practices of high exposure risk were: the confrontation of pesticide spills in the stage of spray solution preparation (76.4%), the use of low-technology and faulty sprayers (67.9%), and spraying under inappropriate weather (46.5%). A large proportion (34%) of the farmers reported multiple intoxication symptoms by pesticide use; the most common were irritation of skin and eyes, headache, and dizziness. Nevertheless, most farmers thought these symptoms were usual; only few reported visiting the doctor. Findings clearly indicated a high level of risk exposure to pesticides among farmers of the study area, calling upon immediate interventions toward increasing awareness about alternative pest control practices with less pesticide use.

Common sense and nuclear peace

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

Zacharias, J.R.; Gordon, M.; Davis, S.R.

The authors note that arms control, arms limitation, and arms reduction, though moving in the right direction, are not sufficient. Possible escalation of a small-scale war between nuclear superpowers or of an accident into a major conflagration is our greatest worry, they think, even though there is no justification for ever resorting to nuclear weaponry. We must find new ways to prevent and resolve conflict among nations other than military solutions. Further, the stakes are too high to leave the settling of international disputes in the hands of the world's military establishments, or even its anti-military establishments. To reduce andmore » then eliminate the risk of nuclear war will require a profound change in attitude, both here and in the Soviet Union. The authors feel we must both learn to bargain and barter about the things that really matter. We must realize that we cannot compete on both economic and military trufs simultaneously, because they require different attitudes and policies. Good treaties based on commonality of interest make good neighbors, and can lead to a less-belligerent world. 17 references.« less

New interpretation of data of the Earth's solid core

NASA Astrophysics Data System (ADS)

Guliyev, H. H.

2017-06-01

The commonly accepted scientific opinions on the inner core as the deformable solid globe are based on the solution of the problem on the distribution of elastic parameters in the inner structures of the Earth. The given solution is obtained within the necessary integral conditions on its self-weight, moment of inertia concerning the axes of rotation and periods of free oscillations of the Earth. It is shown that this solution does not satisfy the mechanics of the deformable solid body with sufficient local conditions following from basic principles concerning the strength, stability and actuality of velocities of propagation of elastic waves. The violation of local conditions shows that the inner core cannot exist in the form of the deformable solid body within the commonly accepted elastic parameters.

Mechanics of gravitational spreading of steep-sided ridges («sackung»)

USGS Publications Warehouse

Savage, W.Z.; Varnes, D.J.

1987-01-01

Large-scale gravitational spreading of steep-sided ridges characterized by linear fissures, trenches, and uphill-facing scarps high on the sides and tops of ridges are known worldwide. Such spreading, termed sackung, is commonly attributed to pervasive plastic deformation of a rock mass, and is here analyzed as such. Beginning with a previously developed exact elastic solution for gravity-induced stresses in a symmetric ridge, stresses calculated from the exact solution are used in the Coulomb failure criterion to determine the extent of ridge failure under self-weight. Finally, when the regions of failure are established, a plastic flow solution is applied to predict the location of and sense of movement on upward-facing scarps near ridge crests and other features common in sackung. ?? 1987 International Assocaition of Engineering Geology.

Common benefit from a perspective of "Non-traditional Partners": A proposed agenda to address the status quo in Global Space Governance

NASA Astrophysics Data System (ADS)

Aganaba-Jeanty, Timiebi

2015-12-01

It is presupposed that there is a dominant position in interpreting the freedom of Outer Space which has not given much real significance to the idea of common benefit. The reason that this causes difficulty is that there is an ambiguity to common benefit. This dominant position however sees the issue of benefit sharing in the context of the perceived tension between established space faring nations and emerging and aspirant States and the idea that freedom could take on a different meaning depending on where one is on the scale of development. It fails to recognize that solutions to contemporary and historical governance challenges have been much less oriented towards the interests of less developed States or new entrants, making the accrual and sharing of benefits dependent on the free will of those States able to carry out a variety of space activities independently. As a result of this, the debate around common benefit is exploited to seek individual benefit derived for a State as opposed to what our effort to use space collectively can generate. In recent times, the issue has not received much attention. This is because it is believed to be partly resolved through normative frameworks such as Article 1 of the Outer Space Treaty and the Space Benefits Declaration. While an attempt to re-address historical contentious issues, asserted to be resolved, may appear illusory or futile; such analysis can be useful depending on the account that the reader believes should be given to the normative character of human nature. To this end, the writings of legal, political and social theorists and methodologies from Critical Legal Schools may prove insightful for a deeper contextualization of the historical debate, the current understanding of the freedoms of Outer Space as well as unearth future perspectives to aid in addressing the current pressing space related issue of our time: Sustainability of Space Activities. This article proposes three main issue areas to investigate to find solutions to some of the perceived tensions prevalent in space governance:

Early Warning Signs. A Solution-Finding Report

ERIC Educational Resources Information Center

Sullivan, Robert, Comp.

2017-01-01

This Solution-Finding Report provides information, requested by Tara Zuber with the Great Lakes Comprehensive Center (GLCC) at American Institutes for Research (AIR), for resources with evidence-based practices that look at the social and emotional causes that impact the lack of student learning and engagement, for GLCC's Early Warning Signs work.…

Extraction of Pentachlorophenol from Soils using Environmentally Benign Lactic Acid Solutions

EPA Science Inventory

Soil contamination with pentachlorophenol (PCP) is widespread across the globe. Soil washing/extraction is a common technique to remove this compound. Several soil washing/extraction solutions have been used but a majority of them have the problem of persistence in the environmen...

Trading a Problem-solving Task

NASA Astrophysics Data System (ADS)

Matsubara, Shigeo

This paper focuses on a task allocation problem, especially cases where the task is to find a solution in a search problem or a constraint satisfaction problem. If the search problem is hard to solve, a contractor may fail to find a solution. Here, the more computational resources such as the CPU time the contractor invests in solving the search problem, the more a solution is likely to be found. This brings about a new problem that a contractee has to find an appropriate level of the quality in a task achievement as well as to find an efficient allocation of a task among contractors. For example, if the contractee asks the contractor to find a solution with certainty, the payment from the contractee to the contractor may exceed the contractee's benefit from obtaining a solution, which discourages the contractee from trading a task. However, solving this problem is difficult because the contractee cannot ascertain the contractor's problem-solving ability such as the amount of available resources and knowledge (e.g. algorithms, heuristics) or monitor what amount of resources are actually invested in solving the allocated task. To solve this problem, we propose a task allocation mechanism that is able to choose an appropriate level of the quality in a task achievement and prove that this mechanism guarantees that each contractor reveals its true information. Moreover, we show that our mechanism can increase the contractee's utility compared with a simple auction mechanism by using computer simulation.

Students' Perceptions of a Self-Diagnosis Task

NASA Astrophysics Data System (ADS)

Safadi, Rafi'; Yerushalmi, Edit

2009-11-01

What happens when students are required to engage in a self-diagnosis task; in other words get time and credit for identifying mistakes they made assisted by a sample solution? We examine this question using data collected on 180 high school students in the Arab sector in Israel. Students were able to find significant differences between their solutions and the sample solution. Yet many did not provide self-explanations indicating that they acknowledged a conflict between their mental models and the scientific model. Further, students also addressed non-significant differences. They apparently referred to the sample solution as an ultimate template and identified external deviations from it as flaws or weaknesses. Students reflected on their personal solution process, and the materials used in the task. The findings suggest allocating time for scaffolding "self-diagnosis."

Comparison of the Efficacy and Safety of Sodium Phosphate Tablets and Polyethylene Glycol Solution for Bowel Cleansing in Healthy Korean Adults

PubMed Central

Lee, Seung-Hwa; Kim, Kwang-Min; Seo, Sang-Wook; Kang, Joon-Koo; Lee, Eun-Hye; Lee, Dong-Ryul

2014-01-01

Purpose Bowel cleansing is generally regarded as time-consuming and unpleasant among patients. Patients commonly state that bowel preparation provokes more discomfort than the actual colonoscopic examination. The purpose of this study was to compare two regimens of sodium phosphate (NaP) tablets versus polyethylene glycol (PEG) solution for bowel preparation in healthy Korean adults. Materials and Methods This was a single center, prospective, open-label, investigator-blinded, randomized, controlled-pilot study. A total of 62 healthy Korean subjects were randomly assigned to two groups (NaP vs. PEG). Efficacy, safety, and patient-related outcomes, as well as procedural parameters, were evaluated. Results Although there were no significant differences in total Ottawa bowel quality score, fluid scores and the rate of adequate bowel preparation were significantly better in the NaP group than the PEG group. Additionally, the NaP group showed better results regarding patient tolerance, satisfaction, preference, and rate of adverse events than the PEG group. Significant fluctuations in specific serum electrolytes were common and of a greater magnitude in the NaP group than the PEG group. However, these abnormalities were transient and did not result in serious complications and side effects. Conclusion In this study, NaP tablets were shown to be an effective, well-tolerated, and acceptable regimen for bowel preparation. Also, our study suggests that NaP tablets may be safe and can be used as a bowel cleansing agent in healthy adults undergoing elective colonoscopy. Further multicenter, large scale studies are needed to confirm these findings. PMID:25323890

Stability of the Kasner universe in f (T ) gravity

NASA Astrophysics Data System (ADS)

Paliathanasis, Andronikos; Said, Jackson Levi; Barrow, John D.

2018-02-01

f (T ) gravity theory offers an alternative context in which to consider gravitational interactions where torsion, rather than curvature, is the mechanism by which gravitation is communicated. We investigate the stability of the Kasner solution with several forms of the arbitrary Lagrangian function examined within the f (T ) context. This is a Bianchi type-I vacuum solution with anisotropic expansion factors. In the f (T ) gravity setting, the solution must conform to a set of conditions in order to continue to be a vacuum solution of the generalized field equations. With this solution in hand, the perturbed field equations are determined for power-law and exponential forms of the f (T ) function. We find that the point which describes the Kasner solution is a saddle point which means that the singular solution is unstable. However, we find the de Sitter universe is a late-time attractor. In general relativity, the cosmological constant drives the isotropization of the spacetime while in this setting the extra f (T ) contributions now provide this impetus.

The Shortlist Method for fast computation of the Earth Mover's Distance and finding optimal solutions to transportation problems.

PubMed

Gottschlich, Carsten; Schuhmacher, Dominic

2014-01-01

Finding solutions to the classical transportation problem is of great importance, since this optimization problem arises in many engineering and computer science applications. Especially the Earth Mover's Distance is used in a plethora of applications ranging from content-based image retrieval, shape matching, fingerprint recognition, object tracking and phishing web page detection to computing color differences in linguistics and biology. Our starting point is the well-known revised simplex algorithm, which iteratively improves a feasible solution to optimality. The Shortlist Method that we propose substantially reduces the number of candidates inspected for improving the solution, while at the same time balancing the number of pivots required. Tests on simulated benchmarks demonstrate a considerable reduction in computation time for the new method as compared to the usual revised simplex algorithm implemented with state-of-the-art initialization and pivot strategies. As a consequence, the Shortlist Method facilitates the computation of large scale transportation problems in viable time. In addition we describe a novel method for finding an initial feasible solution which we coin Modified Russell's Method.

The Shortlist Method for Fast Computation of the Earth Mover's Distance and Finding Optimal Solutions to Transportation Problems

PubMed Central

Gottschlich, Carsten; Schuhmacher, Dominic

2014-01-01

Finding solutions to the classical transportation problem is of great importance, since this optimization problem arises in many engineering and computer science applications. Especially the Earth Mover's Distance is used in a plethora of applications ranging from content-based image retrieval, shape matching, fingerprint recognition, object tracking and phishing web page detection to computing color differences in linguistics and biology. Our starting point is the well-known revised simplex algorithm, which iteratively improves a feasible solution to optimality. The Shortlist Method that we propose substantially reduces the number of candidates inspected for improving the solution, while at the same time balancing the number of pivots required. Tests on simulated benchmarks demonstrate a considerable reduction in computation time for the new method as compared to the usual revised simplex algorithm implemented with state-of-the-art initialization and pivot strategies. As a consequence, the Shortlist Method facilitates the computation of large scale transportation problems in viable time. In addition we describe a novel method for finding an initial feasible solution which we coin Modified Russell's Method. PMID:25310106

Generalized perturbation (n, M)-fold Darboux transformations and multi-rogue-wave structures for the modified self-steepening nonlinear Schrödinger equation.

PubMed

Wen, Xiao-Yong; Yang, Yunqing; Yan, Zhenya

2015-07-01

In this paper, a simple and constructive method is presented to find the generalized perturbation (n,M)-fold Darboux transformations (DTs) of the modified nonlinear Schrödinger (MNLS) equation in terms of fractional forms of determinants. In particular, we apply the generalized perturbation (1,N-1)-fold DTs to find its explicit multi-rogue-wave solutions. The wave structures of these rogue-wave solutions of the MNLS equation are discussed in detail for different parameters, which display abundant interesting wave structures, including the triangle and pentagon, etc., and may be useful to study the physical mechanism of multirogue waves in optics. The dynamical behaviors of these multi-rogue-wave solutions are illustrated using numerical simulations. The same Darboux matrix can also be used to investigate the Gerjikov-Ivanov equation such that its multi-rogue-wave solutions and their wave structures are also found. The method can also be extended to find multi-rogue-wave solutions of other nonlinear integrable equations.

Charged boson stars and black holes with nonminimal coupling to gravity

NASA Astrophysics Data System (ADS)

Verbin, Y.; Brihaye, Y.

2018-02-01

We find new spherically symmetric charged boson star solutions of a complex scalar field coupled nonminimally to gravity by a "John-type" term of Horndeski theory, that is a coupling between the kinetic scalar term and Einstein tensor. We study the parameter space of the solutions and find two distinct families according to their position in parameter space. More widespread is the family of solutions (which we call branch 1) existing for a finite interval of the central value of the scalar field starting from zero and ending at some finite maximal value. This branch contains as a special case the charged boson stars of the minimally coupled theory. In some regions of parameter space we find a new second branch ("branch 2") of solutions which are more massive and more stable than those of branch 1. This second branch exists also in a finite interval of the central value of the scalar field, but its end points (either both or in some cases only one) are extremal Reissner-Nordström black hole solutions.

Ischemia of the glans penis following circumcision: case report and revision of the literature.

PubMed

Pepe, Pietro; Pietropaolo, Francesco; Candiano, Giuseppe; Pennisi, Michele

2015-03-31

Ischemic complications of the glans penis are rare and commonly result from trauma, inadvertent administration of vasoconstrictive solutions, diabetes mellitus, circumcision and vasculitis; we refer about a young man with severe ischemia of the glans penis following circumcision. The patient had undergone circumcision 5 days before in a surgery department under local anesthesia (1% mepivacaine hydrochloride). The patient noticed a brownish color and edema of the glans penis at 24 h after he opened the wound dressing, but arrived to our hospital only 5 days after circumcision because these findings had progressed. Physical examination revealed the black color or necrotic appearance of the glans penis, and edema on the dorsal penile skin. The patient underwent antibiotic, antiplatatelet, corticosteroid and iperbaric therapy achieving a complete restitutio ad integrum.

Collective induction without cooperation? Learning and knowledge transfer in cooperative groups and competitive auctions.

PubMed

Maciejovsky, Boris; Budescu, David V

2007-05-01

There is strong evidence that groups perform better than individuals do on intellective tasks with demonstrably correct solutions. Typically, these studies assume that group members share common goals. The authors extend this line of research by replacing standard face-to-face group interactions with competitive auctions, allowing for conflicting individual incentives. In a series of studies involving the well-known Wason selection task, they demonstrate that competitive auctions induce learning effects equally impressive as those of standard group interactions, and they uncover specific and general knowledge transfers from these institutions to new reasoning problems. The authors identify payoff feedback and information pooling as the driving factors underlying these findings, and they explain these factors within the theoretical framework of collective induction. ((c) 2007 APA, all rights reserved).

Affinity Chromatography in Nonionic Detergent Solutions

NASA Astrophysics Data System (ADS)

Robinson, Jack B.; Strottmann, James M.; Wick, Donald G.; Stellwagen, Earle

1980-10-01

Anionic dye affinity chromatography is commonly unproductive in the presence of nonionic detergents used to extract particulate proteins. Using lactate dehydrogenase as a model protein, Cibacron blue F3GA as a model dye, and Triton X-100 as a model detergent, we find that the dye is encapsulated in nonionic detergent micelles, rendering the dye incapable of ligation with the enzyme. However, the dye can be liberated from the micelles without altering the nonionic detergent concentration by addition of an anionic detergent, such as deoxycholate or sodium dodecyl sulfate, forming mixed anionic/nonionic micelles that displace the anionic dye. Encapsulation of the anionic detergents prevents their activity as protein denaturants. These observations have been successfully translated to the dye affinity chromatography of a detergent extract of brain particulate cyclic nucleotide phosphodiesterase.

Waste collection in developing countries - Tackling occupational safety and health hazards at their source

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

Bleck, Daniela, E-mail: bleck.daniela@baua.bund.de; Wettberg, Wieland, E-mail: wettberg.wieland@baua.bund.de

2012-11-15

Waste management procedures in developing countries are associated with occupational safety and health risks. Gastro-intestinal infections, respiratory and skin diseases as well as muscular-skeletal problems and cutting injuries are commonly found among waste workers around the globe. In order to find efficient, sustainable solutions to reduce occupational risks of waste workers, a methodological risk assessment has to be performed and counteractive measures have to be developed according to an internationally acknowledged hierarchy. From a case study in Addis Ababa, Ethiopia suggestions for the transferral of collected household waste into roadside containers are given. With construction of ramps to dump collectedmore » household waste straight into roadside containers and an adaptation of pushcarts and collection procedures, the risk is tackled at the source.« less

CRITICAL EVALUATION OF MAGNETIC FIELD DETECTIONS REPORTED FOR PULSATING B-TYPE STARS IN LIGHT OF ESPaDOnS, NARVAL, AND REANALYZED FORS1/2 OBSERVATIONS

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

Shultz, M.; Wade, G. A.; Grunhut, J.

2012-05-01

Recent spectropolarimetric studies of seven slowly pulsating B (SPB) and {beta} Cep stars have suggested that photospheric magnetic fields are more common in B-type pulsators than in the general population of B stars, suggesting a significant connection between magnetic and pulsational phenomena. We present an analysis of new and previously published spectropolarimetric observations of these stars. New Stokes V observations obtained with the high-resolution ESPaDOnS and Narval instruments confirm the presence of a magnetic field in one of the stars ({epsilon} Lup), but find no evidence of magnetism in five others. A re-analysis of the published longitudinal field measurements obtainedmore » with the low-resolution FORS1/2 spectropolarimeters finds that the measurements of all stars show more scatter from zero than can be attributed to Gaussian noise, suggesting the presence of a signal and/or systematic underestimation of error bars. Re-reduction and re-measurement of the FORS1/2 spectra from the ESO archive demonstrates that small changes in reduction procedure lead to substantial changes in the inferred longitudinal field, and substantially reduces the number of field detections at the 3{sigma} level. Furthermore, we find that the published periods are not unique solutions to the time series of either the original or the revised FORS1/2 data. We conclude that the reported field detections, proposed periods, and field geometry models for {alpha} Pyx, 15 CMa, 33 Eri, and V1449 Aql are artifacts of the data analysis and reduction procedures, and that magnetic fields at the reported strength are no more common in SPB/{beta} Cep stars than in the general population of B stars.« less

Endoscopic findings in patients presenting with dysphagia: analysis of a national endoscopy database.

PubMed

Krishnamurthy, Chaya; Hilden, Kristen; Peterson, Kathryn A; Mattek, Nora; Adler, Douglas G; Fang, John C

2012-03-01

Dysphagia is a common problem and an indication for upper endoscopy. There is no data on the frequency of the different endoscopic findings and whether they change according to demographics or by single versus repeat endoscopy. To determine the prevalence of endoscopic findings in patients with dysphagia and whether findings differ in regard to age, gender, ethnicity, and repeat procedure. This was a retrospective study using a national endoscopic database (CORI). A total of 30,377 patients underwent esophagogastroduodenoscopy (EGD) for dysphagia of which 4,202 patients were repeat endoscopies. Overall frequency of endoscopic findings was determined by gender, age, ethnicity, and single vs. repeat procedures. Esophageal stricture was the most common finding followed by normal, esophagitis/ulcer (EU), Schatzki ring (SR), esophageal food impaction (EFI), and suspected malignancy. Males were more likely to undergo repeat endoscopies and more likely to have stricture, EU, EFI, and suspected malignancy (P = 0.001). Patients 60 years or older had a higher prevalence of stricture, EU, SR, and suspected malignancy (P < 0.0001). Esophageal stricture was most common in white non-Hispanic patients compared to other ethnic groups. In patients undergoing repeat EGD, stricture, SR, EFI, and suspected malignancy were more common (P < 0.0001). The prevalence of endoscopic findings differs significantly by gender, age, and repeat procedure. The most common findings in descending order were stricture, normal, EU, SR, EFI, and suspected malignancy. For patients undergoing a repeat procedure, normal and EU were less common and all other abnormal findings were significantly more common.

Static Solutions of Einstein's Equations with Cylindrical Symmetry

ERIC Educational Resources Information Center

Trendafilova, C. S.; Fulling, S. A.

2011-01-01

In analogy with the standard derivation of the Schwarzschild solution, we find all static, cylindrically symmetric solutions of the Einstein field equations for vacuum. These include not only the well-known cone solution, which is locally flat, but others in which the metric coefficients are powers of the radial coordinate and the spacetime is…

Fingering patterns in magnetic fluids: Perturbative solutions and the stability of exact stationary shapes

NASA Astrophysics Data System (ADS)

Anjos, Pedro H. A.; Lira, Sérgio A.; Miranda, José A.

2018-04-01

We examine the formation of interfacial patterns when a magnetic liquid droplet (ferrofluid, or a magnetorheological fluid), surrounded by a nonmagnetic fluid, is subjected to a radial magnetic field in a Hele-Shaw cell. By using a vortex-sheet formalism, we find exact stationary solutions for the fluid-fluid interface in the form of n -fold polygonal shapes. A weakly nonlinear, mode-coupling method is then utilized to find time-evolving perturbative solutions for the interfacial patterns. The stability of such nonzero surface tension exact solutions is checked and discussed, by trying to systematically approach the exact stationary shapes through perturbative solutions containing an increasingly larger number of participating Fourier modes. Our results indicate that the exact stationary solutions of the problem are stable, and that a good matching between exact and perturbative shape solutions is achieved just by using a few Fourier modes. The stability of such solutions is substantiated by a linearization process close to the stationary shape, where a system of mode-coupling equations is diagonalized, determining the eigenvalues which dictate the stability of a fixed point.

Constrained Least Squares Estimators of Oblique Common Factors.

ERIC Educational Resources Information Center

McDonald, Roderick P.

1981-01-01

An expression is given for weighted least squares estimators of oblique common factors of factor analyses, constrained to have the same covariance matrix as the factors they estimate. A proof of the uniqueness of the solution is given. (Author/JKS)

Introducing the MCHF/OVRP/SDMP: Multicapacitated/Heterogeneous Fleet/Open Vehicle Routing Problems with Split Deliveries and Multiproducts

PubMed Central

Yilmaz Eroglu, Duygu; Caglar Gencosman, Burcu; Cavdur, Fatih; Ozmutlu, H. Cenk

2014-01-01

In this paper, we analyze a real-world OVRP problem for a production company. Considering real-world constrains, we classify our problem as multicapacitated/heterogeneous fleet/open vehicle routing problem with split deliveries and multiproduct (MCHF/OVRP/SDMP) which is a novel classification of an OVRP. We have developed a mixed integer programming (MIP) model for the problem and generated test problems in different size (10–90 customers) considering real-world parameters. Although MIP is able to find optimal solutions of small size (10 customers) problems, when the number of customers increases, the problem gets harder to solve, and thus MIP could not find optimal solutions for problems that contain more than 10 customers. Moreover, MIP fails to find any feasible solution of large-scale problems (50–90 customers) within time limits (7200 seconds). Therefore, we have developed a genetic algorithm (GA) based solution approach for large-scale problems. The experimental results show that the GA based approach reaches successful solutions with 9.66% gap in 392.8 s on average instead of 7200 s for the problems that contain 10–50 customers. For large-scale problems (50–90 customers), GA reaches feasible solutions of problems within time limits. In conclusion, for the real-world applications, GA is preferable rather than MIP to reach feasible solutions in short time periods. PMID:25045735

Documenting Sociolinguistic Variation in Lesser-Studied Indigenous Communities: Challenges and Practical Solutions

ERIC Educational Resources Information Center

Mansfield, John; Stanford, James

2017-01-01

Documenting sociolinguistic variation in lesser-studied languages presents methodological challenges, but also offers important research opportunities. In this paper we examine three key methodological challenges commonly faced by researchers who are outsiders to the community. We then present practical solutions for successful variationist…

Thermodynamics on the Molality Scale

ERIC Educational Resources Information Center

Canagaratna, Sebastian G.; Maheswaran, M.

2013-01-01

For physical measurements, the compositions of solutions, especially electrolyte solutions, are expressed in terms of molality rather than mole fractions. The development of the necessary thermodynamic equations directly in terms of molality is not common in textbooks, and the treatment in the literature is not very systematic. We develop a…

Surfing Global Change: Negotiating Sustainable Solutions

ERIC Educational Resources Information Center

Ahamer, Gilbert

2006-01-01

SURFING GLOBAL CHANGE (SGC) serves as a procedural shell for attaining sustainable solutions for any interdisciplinary issue and is intended for use in advanced university courses. The participants' activities evolve through five levels from individual argumentation to molding one's own views for the "common good." The paradigm of…

On the Growth of Ice in Aqueous Solutions Contained in Capillaries

NASA Astrophysics Data System (ADS)

Pruppracher, H. R.

1967-06-01

The growth rate of ice in supercooled water and in dilute aqueous solutions of various salts which dissociate in water into univalent ions was studied. The solutions contained in polyethylene tubes of small bore had concentrations between 10-6 and 10-1 moles liter-1 and were investigated at bath supercoolings between 1° and 15°C. The growth rate of ice which in pure water was found to vary approximately with the square of the bath supercooling was affected in a systematic manner by the type and concentration of the salt in solution. At salt concentrations smaller than 5 × 10-2 moles liter-1 most salts did not affect the growth rate. However, the fluorides were found to increase the growth rate over and above the one in pure water. At concentrations larger than 5 × 10-2 moles liter-1 all the salts reduced the growth rate of ice below the one in pure water. By comparing solutions of salts with common anion it was found that at a particular bath supercooling and salt concentration the growth rate of ice was reduced most in lithium solutions and least in cesium and ammonium solutions. By comparing solutions of salts with common cation it was found that the growth rate of ice was reduced most in fluoride solutions and least in bromide solutions. It was concluded that in solutions with salt concentrations larger than 5 × 10-2 moles liter-1 the rate of dissipation of latent heat which controls the growth rate of ice is affected in a systematic manner by the freezing point lowering effects which result from pure mass transfer conditions prevailing at the ice-solution interface of a stagnant system. Some features of the observed growth rates are discussed in terms of the effect of dissolved salts on the growth forms of ice in aqueous solutions.

Chest CT findings of toxocariasis: correlation with laboratory results.

PubMed

Hur, J H; Lee, I J; Kim, J-H; Kim, D-G; Hwang, H J; Koh, S H; Lee, K

2014-06-01

To assess the relationship between chest computed tomography (CT) findings of patients with toxocariasis and levels of serological markers. A total of 38 cases of patients diagnosed with toxocariasis by enzyme-linked immunosorbent assay (ELISA), CT, and serological markers were retrospectively reviewed. The presence of nodule with or without ground-glass opacity (GGO) halo, consolidation, focal GGO, pleural effusion, and lymphadenopathy at chest CT were evaluated. Statistical analysis was performed with the Fisher's exact test. The most common chest CT findings were nodule (n = 12, 31.6%) and focal GGO (n = 12, 31.6%). In patients with normal eosinophil levels, focal GGO (n = 9, 37.5%) was the most common finding. In contrast, nodule with a GGO halo (n = 7, 50%) was the most common finding in the eosinophilia group. Nodule with a GGO halo was more common in the eosinophilia group, with a statistically significant difference (p = 0.017). Nodule was more common in the eosinophilia group, and focal GGO was more common in the normal eosinophil group. The most common chest CT findings in toxocariasis were nodule with or without GGO halo, and focal GGO. In the eosinophilia group, nodule with a GGO halo was significantly more frequent. Other CT findings did not show a statistically significant relationship with serological markers. Copyright © 2014 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Bretschneider and del Nido solutions: Are they safe for coronary artery bypass grafting? If so, how should we use them?

PubMed

Siddiqi, Shirin; Blackstone, Eugene H; Bakaeen, Faisal G

2018-05-01

A variety of cardioplegic solutions are being used widely today to arrest the heart during coronary artery bypass grafting (CABG) and other cardiac operations. To minimize interruptions during the surgery for intermittent dosing of the cardioplegia and to facilitate less invasive cardiac procedures, single-shot solutions, including Bretschneider and del Nido solutions, have been introduced. This review examines the evidence regarding the safety and efficacy of Bretschneider and del Nido cardioplegia during CABG. The findings support their use in routine low-risk CABG, but finds insufficient evidence to support their safety in high-risk surgeries. © 2018 Wiley Periodicals, Inc.

Fatal methemoglobinemia caused by liniment solutions containing sodium nitrite.

PubMed

Saito, T; Takeichi, S; Yukawa, N; Osawa, M

1996-01-01

We describe a case of fatal methemoglobinemia (MetHb-emia) resulting from application of liniment solution containing large quantities of sodium nitrite. As a remedial treatment of atopic dermatitis, the liniment solution was applied all over the boy's body. Autopsy findings showed no significant macroscopic or microscopic findings except blood tinted chocolate brown color and chronic atopic dermatitis over the whole surface of the body. Quantitation of the methemoglobin (MetHb) in the blood was performed using spectrophotometer; MetHb concentration of the blood was 76%. Ion chromatographic determination revealed a nitrite concentration of 1 mg/L in the serum. Such a liniment solution is not authorized by the Ministry of Public Welfare.

Testing Models of Psychopathology in Preschool-aged Children Using a Structured Interview-based Assessment

PubMed Central

Dougherty, Lea R.; Bufferd, Sara J.; Carlson, Gabrielle A.; Klein, Daniel N.

2014-01-01

A number of studies have found that broadband internalizing and externalizing factors provide a parsimonious framework for understanding the structure of psychopathology across childhood, adolescence, and adulthood. However, few of these studies have examined psychopathology in young children, and several recent studies have found support for alternative models, including a bi-factor model with common and specific factors. The present study used parents’ (typically mothers’) reports on a diagnostic interview in a community sample of 3-year old children (n=541; 53.9 % male) to compare the internalizing-externalizing latent factor model with a bi-factor model. The bi-factor model provided a better fit to the data. To test the concurrent validity of this solution, we examined associations between this model and paternal reports and laboratory observations of child temperament. The internalizing factor was associated with low levels of surgency and high levels of fear; the externalizing factor was associated with high levels of surgency and disinhibition and low levels of effortful control; and the common factor was associated with high levels of surgency and negative affect and low levels of effortful control. These results suggest that psychopathology in preschool-aged children may be explained by a single, common factor influencing nearly all disorders and unique internalizing and externalizing factors. These findings indicate that shared variance across internalizing and externalizing domains is substantial and are consistent with recent suggestions that emotion regulation difficulties may be a common vulnerability for a wide array of psychopathology. PMID:24652485

Parameterized Algorithmics for Finding Exact Solutions of NP-Hard Biological Problems.

PubMed

Hüffner, Falk; Komusiewicz, Christian; Niedermeier, Rolf; Wernicke, Sebastian

2017-01-01

Fixed-parameter algorithms are designed to efficiently find optimal solutions to some computationally hard (NP-hard) problems by identifying and exploiting "small" problem-specific parameters. We survey practical techniques to develop such algorithms. Each technique is introduced and supported by case studies of applications to biological problems, with additional pointers to experimental results.

Determination of thermophysical characteristics of solid materials by electrical modelling of the solutions to the inverse problems in nonsteady heat conduction

NASA Technical Reports Server (NTRS)

Kozdoba, L. A.; Krivoshei, F. A.

1985-01-01

The solution of the inverse problem of nonsteady heat conduction is discussed, based on finding the coefficient of the heat conduction and the coefficient of specific volumetric heat capacity. These findings are included in the equation used for the electrical model of this phenomenon.

Problem Solving as an Encoding Task: A Special Case of the Generation Effect

ERIC Educational Resources Information Center

Kizilirmak, Jasmin M.; Wiegmann, Berit; Richardson-Klavehn, Alan

2016-01-01

Recent evidence suggests that solving problems through insight can enhance long-term memory for the problem and its solution. Previous findings have shown that generation of the solution as well as experiencing a feeling of Aha! can have a beneficial relationship to later memory. These findings lead to the question of how learning in…

Nonlocal nonlinear Schrödinger equations and their soliton solutions

NASA Astrophysics Data System (ADS)

Gürses, Metin; Pekcan, Aslı

2018-05-01

We study standard and nonlocal nonlinear Schrödinger (NLS) equations obtained from the coupled NLS system of equations (Ablowitz-Kaup-Newell-Segur (AKNS) equations) by using standard and nonlocal reductions, respectively. By using the Hirota bilinear method, we first find soliton solutions of the coupled NLS system of equations; then using the reduction formulas, we find the soliton solutions of the standard and nonlocal NLS equations. We give examples for particular values of the parameters and plot the function |q(t, x)|2 for the standard and nonlocal NLS equations.

Satisfying positivity requirement in the Beyond Complex Langevin approach

NASA Astrophysics Data System (ADS)

Wyrzykowski, Adam; Ruba, Błażej Ruba

2018-03-01

The problem of finding a positive distribution, which corresponds to a given complex density, is studied. By the requirement that the moments of the positive distribution and of the complex density are equal, one can reduce the problem to solving the matching conditions. These conditions are a set of quadratic equations, thus Groebner basis method was used to find its solutions when it is restricted to a few lowest-order moments. For a Gaussian complex density, these approximate solutions are compared with the exact solution, that is known in this special case.

Event Reports Promoting Root Cause Analysis.

PubMed

Pandit, Swananda; Gong, Yang

2016-01-01

Improving health is the sole objective of medical care. Unfortunately, mishaps or patient safety events happen during the care. If the safety events were collected effectively, they would help identify patterns, underlying causes, and ultimately generate proactive and remedial solutions for prevention of recurrence. Based on the AHRQ Common Formats, we examine the quality of patient safety incident reports and describe the initial data requirement that can support and accelerate effective root cause analysis. The ultimate goal is to develop a knowledge base of patient safety events and their common solutions which can be readily available for sharing and learning.

On parametric Gevrey asymptotics for some nonlinear initial value Cauchy problems

NASA Astrophysics Data System (ADS)

Lastra, A.; Malek, S.

2015-11-01

We study a nonlinear initial value Cauchy problem depending upon a complex perturbation parameter ɛ with vanishing initial data at complex time t = 0 and whose coefficients depend analytically on (ɛ, t) near the origin in C2 and are bounded holomorphic on some horizontal strip in C w.r.t. the space variable. This problem is assumed to be non-Kowalevskian in time t, therefore analytic solutions at t = 0 cannot be expected in general. Nevertheless, we are able to construct a family of actual holomorphic solutions defined on a common bounded open sector with vertex at 0 in time and on the given strip above in space, when the complex parameter ɛ belongs to a suitably chosen set of open bounded sectors whose union form a covering of some neighborhood Ω of 0 in C*. These solutions are achieved by means of Laplace and Fourier inverse transforms of some common ɛ-depending function on C × R, analytic near the origin and with exponential growth on some unbounded sectors with appropriate bisecting directions in the first variable and exponential decay in the second, when the perturbation parameter belongs to Ω. Moreover, these solutions satisfy the remarkable property that the difference between any two of them is exponentially flat for some integer order w.r.t. ɛ. With the help of the classical Ramis-Sibuya theorem, we obtain the existence of a formal series (generally divergent) in ɛ which is the common Gevrey asymptotic expansion of the built up actual solutions considered above.

Common stock solutions, buffers, and media.

PubMed

2001-05-01

This collection of recipes describes the preparation of buffers and reagents used in Current Protocols in Pharmacology for cell culture, manipulation of neural tissue, molecular biological methods, and neurophysiological/neurochemical measurements. RECIPES: Acid, concentrated stock solutions Ammonium hydroxide, concentrated stock solution EDTA (ethylenediaminetetraacetic acid), 0.5 M (pH 8.0) Ethidium bromide staining solution Fetal bovine serum (FBS) Gel loading buffer, 6× LB medium (Luria broth) and LB plates Potassium phosphate buffer, 0.1 M Sodium phosphate buffer, 0.1 M TE (Tris/EDTA) buffer Tris⋅Cl, 1 M.

Formulation and Stability of Solutions.

PubMed

Akers, Michael J

2016-01-01

Ready-to-use solutions are the most preferable and most common dosage forms for injectable and topical ophthalmic products. Drugs formulated as solution almost always have chemical and physical stability challenges as well as solubility limitations and the need to prevent inadvertent microbial contamination issues. The first in this series of articles took us through a discussion of optimizing the physical stability of solutions. This article concludes this series of articles with a discussion on foreign particles, protein aggregation, and immunogenicity; optimizing microbiological activity; and osmolality (tonicity) agents, and discusses how these challenges and issues are addressed.

Potential of Mean Force Calculations of Solute Permeation Across UT-B and AQP1: A Comparison between Molecular Dynamics and 3D-RISM.

PubMed

Ariz-Extreme, Igor; Hub, Jochen S

2017-02-23

Membrane channels facilitate the efficient and selective flux of various solutes across biological membranes. A common approach to investigate the selectivity of a channel has been the calculation of potentials of mean force (PMFs) for solute permeation across the pore. PMFs have been frequently computed from molecular dynamics (MD) simulations, yet the three-dimensional reference interaction site model (3D-RISM) has been suggested as a computationally efficient alternative to MD. Whether the two methods yield comparable PMFs for solute permeation has remained unclear. In this study, we calculated potentials of mean force for water, ammonia, urea, molecular oxygen, and methanol across the urea transporter B (UT-B) and aquaporin-1 (AQP1), using 3D-RISM, as well as using MD simulations and umbrella sampling. To allow direct comparison between the PMFs from 3D-RISM and MD, we ensure that all PMFs refer to a well-defined reference area in the bulk or, equivalently, to a well-defined density of channels in the membrane. For PMFs of water permeation, we found reasonable agreement between the two methods, with differences of ≲3 kJ mol -1 . In contrast, we found stark discrepancies for the PMFs for all other solutes. Additional calculations confirm that discrepancies between MD and 3D-RISM are not explained by the choice for the closure relation, the definition the reaction coordinate (center of mass-based versus atomic site-based), details of the molecule force field, or fluctuations of the protein. Comparison of the PMFs suggests that 3D-RISM may underestimate effects from hydrophobic solute-channel interactions, thereby, for instance, missing the urea binding sites in UT-B. Furthermore, we speculate that the orientational averages inherent to 3D-RISM might lead to discrepancies in the narrow channel lumen. These findings suggest that current 3D-RISM solvers provide reasonable estimates for the PMF for water permeation, but that they are not suitable to study the selectivity of membrane channels with respect to uncharged nonwater solutes.

Oxygen stress reduces zoospore survival of Phytophthora species in a simulated aquatic system.

PubMed

Kong, Ping; Hong, Chuanxue

2014-05-13

The genus Phytophthora includes a group of agriculturally important pathogens and they are commonly regarded as water molds. They produce motile zoospores that can move via water currents and on their own locomotion in aquatic environments. However, zoosporic response to dissolved oxygen, an important water quality parameter, is not known. Like other water quality parameters, dissolved oxygen concentration in irrigation reservoirs fluctuates dramatically over time. The aim of this study was to determine whether and how zoospore survival may be affected by elevated and low concentrations of dissolved oxygen in water to better understand the aquatic biology of these pathogens in irrigation reservoirs. Zoospores of P. megasperma, P. nicotianae, P. pini and P. tropicalis were assessed for survival in 10% Hoagland's solution at a range of dissolved concentrations from 0.9 to 20.1 mg L(-1) for up to seven exposure times from 0 to 72 h. Zoospore survival was measured by resultant colony counts per ml. Zoospores of these species survived the best in control Hoagland's solution at dissolved oxygen concentrations of 5.3 to 5.6 mg L(-1). Zoospore survival rates decreased with increasing and decreasing concentration of dissolved oxygen, depending upon Phytophthora species and exposure time. Overall, P. megasperma and P. pini are less sensitive than P. nicotianae and P. tropicalis to hyperoxia and hypoxia conditions. Zoospores in the control solution declined over time and this natural decline process was enhanced under hyperoxia and hypoxia conditions. These findings suggest that dramatic fluctuations of dissolved oxygen in irrigation reservoirs contribute to the population decline of Phytophthora species along the water path in the same reservoirs. These findings advanced our understanding of the aquatic ecology of these pathogens in irrigation reservoirs. They also provided a basis for pathogen risk mitigation by prolonging the turnover time of runoff water in recycling irrigation systems via better system designs.

Oxygen stress reduces zoospore survival of Phytophthora species in a simulated aquatic system

PubMed Central

2014-01-01

Background The genus Phytophthora includes a group of agriculturally important pathogens and they are commonly regarded as water molds. They produce motile zoospores that can move via water currents and on their own locomotion in aquatic environments. However, zoosporic response to dissolved oxygen, an important water quality parameter, is not known. Like other water quality parameters, dissolved oxygen concentration in irrigation reservoirs fluctuates dramatically over time. The aim of this study was to determine whether and how zoospore survival may be affected by elevated and low concentrations of dissolved oxygen in water to better understand the aquatic biology of these pathogens in irrigation reservoirs. Results Zoospores of P. megasperma, P. nicotianae, P. pini and P. tropicalis were assessed for survival in 10% Hoagland’s solution at a range of dissolved concentrations from 0.9 to 20.1 mg L-1 for up to seven exposure times from 0 to 72 h. Zoospore survival was measured by resultant colony counts per ml. Zoospores of these species survived the best in control Hoagland’s solution at dissolved oxygen concentrations of 5.3 to 5.6 mg L-1. Zoospore survival rates decreased with increasing and decreasing concentration of dissolved oxygen, depending upon Phytophthora species and exposure time. Overall, P. megasperma and P. pini are less sensitive than P. nicotianae and P. tropicalis to hyperoxia and hypoxia conditions. Conclusion Zoospores in the control solution declined over time and this natural decline process was enhanced under hyperoxia and hypoxia conditions. These findings suggest that dramatic fluctuations of dissolved oxygen in irrigation reservoirs contribute to the population decline of Phytophthora species along the water path in the same reservoirs. These findings advanced our understanding of the aquatic ecology of these pathogens in irrigation reservoirs. They also provided a basis for pathogen risk mitigation by prolonging the turnover time of runoff water in recycling irrigation systems via better system designs. PMID:24885900

An Experimental Study of the Effects of A Rotating Magnetic Field on Electrically Conducting Aqueous Solutions

NASA Technical Reports Server (NTRS)

Ramachandran Narayanan; Mazuruk, Konstantin

1998-01-01

The use of a rotating magnetic field for stirring metallic melts has been a commonly adopted practice for a fairly long period. The elegance of the technique stems from its non-intrusive nature and the intense stirring it can produce in an electrically conducting medium. A further application of the method in recent times has been in the area of crystal growth from melts (e.g. germanium). The latter experiments have been mainly research oriented in order to understand the basic physics of the process and to establish norms for optimizing such a technique for the commercial production of crystals. When adapted for crystal growth applications, the rotating magnetic field is used to induce a slow flow or rotation in the melt which in effect significantly curtails temperature field oscillations in the melt. These oscillations are known to cause dopant striations and thereby inhomogeneities in the grown crystal that essentially degrades the crystal quality. The applied field strength is typically of the order of milli-Teslas with a frequency range between 50-400 Hz. In this investigation, we report findings from experiments that explore the feasibility of applying a rotating magnetic field to aqueous salt solutions, that are characterized by conductivities that are several orders of magnitude smaller than semi-conductor melts. The aim is to study the induced magnetic field and consequently the induced flow in such in application. Detailed flow field description obtained through non-intrusive particle displacement tracking will be reported along with an analytical assessment of the results. It is anticipated that the obtained results will facilitate in establishing a parameter range over which the technique can be applied to obtain a desired flow field distribution. This method can find applicability in the growth of crystals from aqueous solutions and give an experimenter another controllable parameter towards improving the quality of the grown crystal.

Flotation of Toxocara canis Eggs in Commercial Bleach and Effects of Bleach Treatment Times on Larval Development in These Eggs.

PubMed

von Dohlen, Alexa Rosypal; Houk-Miles, Alice E; Zajac, Anne M; Lindsay, David S

2017-04-01

Toxocara canis is a common intestinal nematode of young dogs. Puppies contaminate the environment with large numbers of eggs that can embryonate and become infective in less than a month. Embryonated eggs are infectious for humans and other paratenic hosts. Most T. canis infections in humans are asymptomatic; however, migration of T. canis larvae in the eye and in the central nervous system can result in vision loss, blindness, and even death. The eggs of T. canis are highly resistant to harsh environmental conditions and routinely used chemical disinfectants. The objective of this study was to evaluate the effects of full-strength commercial bleach (5.25% sodium hypochlorite solution) treatment on development of T. canis eggs and to report our serendipitous finding that T. canis eggs in dog feces can float in passive fecal flotation tests using bleach. We also demonstrated that T. canis eggs could be identified using the McMaster's fecal eggs counting test using 100% bleach. Toxocara canis eggs collected from the feces of naturally infected 4-8 wk old puppies were treated with full-strength bleach (5.25% sodium hypochlorite solution) for 15 min, 30 min, 60 min, and 120 min; washed free of bleach smell by centrifugation; and resuspended in 0.1 N sulfuric acid solution to undergo larval development at room temperature for 18 days after exposure to bleach. Motile larvae were observed in T. canis eggs in all groups treated for 15-120 min and eggs continuously exposed to bleach for 18 days. Our results indicate that bleach may not be an appropriate disinfectant for dog kennels, cages, or laboratory utensils and work surfaces. Toxocara canis eggs are resistant to bleach treatment and continue to pose a risk for canine and human infections. Further study is needed to find the most appropriate methods for disinfection and removal of eggs to reduce the risk of transmission of this parasite.

Solid state light engines for bioanalytical instruments and biomedical devices

NASA Astrophysics Data System (ADS)

Jaffe, Claudia B.; Jaffe, Steven M.

2010-02-01

Lighting subsystems to drive 21st century bioanalysis and biomedical diagnostics face stringent requirements. Industrywide demands for speed, accuracy and portability mean illumination must be intense as well as spectrally pure, switchable, stable, durable and inexpensive. Ideally a common lighting solution could service these needs for numerous research and clinical applications. While this is a noble objective, the current technology of arc lamps, lasers, LEDs and most recently light pipes have intrinsic spectral and angular traits that make a common solution untenable. Clearly a hybrid solution is required to service the varied needs of the life sciences. Any solution begins with a critical understanding of the instrument architecture and specifications for illumination regarding power, illumination area, illumination and emission wavelengths and numerical aperture. Optimizing signal to noise requires careful optimization of these parameters within the additional constraints of instrument footprint and cost. Often the illumination design process is confined to maximizing signal to noise without the ability to adjust any of the above parameters. A hybrid solution leverages the best of the existing lighting technologies. This paper will review the design process for this highly constrained, but typical optical optimization scenario for numerous bioanalytical instruments and biomedical devices.

Size-dependent control of colloid transport via solute gradients in dead-end channels

PubMed Central

Shin, Sangwoo; Um, Eujin; Sabass, Benedikt; Ault, Jesse T.; Rahimi, Mohammad; Warren, Patrick B.; Stone, Howard A.

2016-01-01

Transport of colloids in dead-end channels is involved in widespread applications including drug delivery and underground oil and gas recovery. In such geometries, Brownian motion may be considered as the sole mechanism that enables transport of colloidal particles into or out of the channels, but it is, unfortunately, an extremely inefficient transport mechanism for microscale particles. Here, we explore the possibility of diffusiophoresis as a means to control the colloid transport in dead-end channels by introducing a solute gradient. We demonstrate that the transport of colloidal particles into the dead-end channels can be either enhanced or completely prevented via diffusiophoresis. In addition, we show that size-dependent diffusiophoretic transport of particles can be achieved by considering a finite Debye layer thickness effect, which is commonly ignored. A combination of diffusiophoresis and Brownian motion leads to a strong size-dependent focusing effect such that the larger particles tend to concentrate more and reside deeper in the channel. Our findings have implications for all manners of controlled release processes, especially for site-specific delivery systems where localized targeting of particles with minimal dispersion to the nontarget area is essential. PMID:26715753

Preliminary Findings: Issues in Surface Movement

NASA Technical Reports Server (NTRS)

Smith, Philip J.; Denning, Rebecca; Obradovich, Jodi; Billings, Charles; Woods, David

1999-01-01

The final report for the grant is presented. The recent goals for this project have been: (1) To identify common surface movement challenges which affect the airlines and Air Traffic Control; (2) To map out possible solutions to these challenges; (3) To start generalizing about the information we are receiving so that major, abstract categories of challenges and potential solutions will begin to emerge. In particular, there are several areas of opportunity which are beginning to emerge from the data, dealing with the need for: (1) Tools to support information exchange regarding priorities (both within an individual airline and between the ATC tower and airlines). Such priorities include both concerns affecting departure throughput as well as the ordering of departures to accommodate other airline considerations; (2) Planning tools to help ATC and airline Ramp staff deal with information about priorities; (3) Implementation of strategies to enable greater flexibility in queueing flights for departures; (4) Tools to provide better coordination and situation awareness during taxiing (within an airline as well as between airlines and between the airlines); (5) Tools to support planning and to deal with the interactions between departures and arrivals. Thus far, the initial interviews and observations at three airlines and two ATC facilities have been completed.

Interactions between protein molecules and the virus removal membrane surface: Effects of immunoglobulin G adsorption and conformational changes on filter performance.

PubMed

Hamamoto, Ryo; Ito, Hidemi; Hirohara, Makoto; Chang, Ryongsok; Hongo-Hirasaki, Tomoko; Hayashi, Tomohiro

2018-03-01

Membrane fouling commonly occurs in all filter types during virus filtration in protein-based biopharmaceutical manufacturing. Mechanisms of decline in virus filter performance due to membrane fouling were investigated using a cellulose-based virus filter as a model membrane. Filter performance was critically dependent on solution conditions; specifically, ionic strength. To understand the interaction between immunoglobulin G (IgG) and cellulose, sensors coated with cellulose were fabricated for surface plasmon resonance and quartz crystal microbalance with energy dissipation measurements. The primary cause of flux decline appeared to be irreversible IgG adsorption on the surface of the virus filter membrane. In particular, post-adsorption conformational changes in the IgG molecules promoted further irreversible IgG adsorption, a finding that could not be adequately explained by DLVO theory. Analyses of adsorption and desorption and conformational changes in IgG molecules on cellulose surfaces mimicking cellulose-based virus removal membranes provide an effective approach for identifying ways of optimizing solution conditions to maximize virus filter performance. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 34:379-386, 2018. © 2017 American Institute of Chemical Engineers.

Analysis of Underactuated Dynamic Locomotion Systems Using Perturbation Expansion: The Twistcar Toy Example

NASA Astrophysics Data System (ADS)

Chakon, Ofir; Or, Yizhar

2017-08-01

Underactuated robotic locomotion systems are commonly represented by nonholonomic constraints where in mixed systems, these constraints are also combined with momentum evolution equations. Such systems have been analyzed in the literature by exploiting symmetries and utilizing advanced geometric methods. These works typically assume that the shape variables are directly controlled, and obtain the system's solutions only via numerical integration. In this work, we demonstrate utilization of the perturbation expansion method for analyzing a model example of mixed locomotion system—the twistcar toy vehicle, which is a variant of the well-studied roller-racer model. The system is investigated by assuming small-amplitude oscillatory inputs of either steering angle (kinematic) or steering torque (mechanical), and explicit expansions for the system's solutions under both types of actuation are obtained. These expressions enable analyzing the dependence of the system's dynamic behavior on the vehicle's structural parameters and actuation type. In particular, we study the reversal in direction of motion under steering angle oscillations about the unfolded configuration, as well as influence of the choice of actuation type on convergence properties of the motion. Some of the findings are demonstrated qualitatively by reporting preliminary motion experiments with a modular robotic prototype of the vehicle.

Development of a highly sensitive and selective method for extractive spectrophotometric determination of aluminum(III) from environmental matrices, synthetic mixtures, and alloys using orthohydroxypropiophenoneisonicotinoylhydrazone.

PubMed

Ramachandraiah, C; Rajesh Kumar, J; Adinarayana Reddy, S; Lee, Jin-Young; Varada Reddy, A

2010-01-01

Orthohydroxypropiophenoneisonicotinoylhydrazone (OHPINH) is proposed as a new sensitive reagent for the spectrophotometric determination of aluminum(III). OHPINH formed a greenish-yellow colored complex with aluminum(III) in buffer solutions of pH 1 to 3. The color in pH 2 was stable for more than 48 h. The complex solution has given maximum absorbance at 390 nm when the reagent was chosen as blank and the absorbance of the reagent at this wavelength is negligible; the molar absorptivity and Sandell's sensitivity being 0.6371x10(4) L mol(-1) cm(-1) and 4.234x10(-3) microg cm(-2), respectively. The system obeys Beer's law in the range of 0.5-3.5 microg mL(-1) with excellent linearity in terms of the correlation coefficient value of 0.999. Most of the common metal ions generally found associated with aluminum(III) do not interfere. The repeatability of the method was checked by finding the relative standard deviation. The developed method has been successfully employed for the determination of aluminum(III) environmental matrices like medicinal and leafy samples, alloys, and synthetic mixtures.

An improved genetic algorithm for multidimensional optimization of precedence-constrained production planning and scheduling

NASA Astrophysics Data System (ADS)

Dao, Son Duy; Abhary, Kazem; Marian, Romeo

2017-06-01

Integration of production planning and scheduling is a class of problems commonly found in manufacturing industry. This class of problems associated with precedence constraint has been previously modeled and optimized by the authors, in which, it requires a multidimensional optimization at the same time: what to make, how many to make, where to make and the order to make. It is a combinatorial, NP-hard problem, for which no polynomial time algorithm is known to produce an optimal result on a random graph. In this paper, the further development of Genetic Algorithm (GA) for this integrated optimization is presented. Because of the dynamic nature of the problem, the size of its solution is variable. To deal with this variability and find an optimal solution to the problem, GA with new features in chromosome encoding, crossover, mutation, selection as well as algorithm structure is developed herein. With the proposed structure, the proposed GA is able to "learn" from its experience. Robustness of the proposed GA is demonstrated by a complex numerical example in which performance of the proposed GA is compared with those of three commercial optimization solvers.

Solving the 10 Most Common Carpet Problems.

ERIC Educational Resources Information Center

Hilton, Michael

1998-01-01

Identifies the 10 most common carpet problems in school facilities and offers solutions. These include: transition areas, moisture, spot removal, recurring spots, cleaning agents, allergens, wicking, biological contamination, equipment selection, and cleaning methods. Ensuring a successful maintenance program results in satisfactory appearance,…

Broadcasting satellite service synthesis using gradient and cyclic coordinate search procedures

NASA Technical Reports Server (NTRS)

Reilly, C. H.; Mount-Campbell, C. A.; Gonsalvez, D. J.; Martin, C. H.; Levis, C. A.; Wang, C. W.

1986-01-01

Two search techniques are considered for solving satellite synthesis problems. Neither is likely to find a globally optimal solution. In order to determine which method performs better and what factors affect their performance, we design an experiment and solve the same problem under a variety of starting solution configuration-algorithm combinations. Since there is no randomization in the experiment, we present results of practical, rather than statistical, significance. Our implementation of a cyclic coordinate search procedure clearly finds better synthesis solutions than our implementation of a gradient search procedure does with our objective of maximizing the minimum C/I ratio computed at test points on the perimeters of the intended service areas. The length of the available orbital arc and the configuration of the starting solution are shown to affect the quality of the solutions found.

Broadcasting satellite service synthesis using gradient and cyclic coordinate search procedures

NASA Technical Reports Server (NTRS)

Reilly, C. H.; Mount-Campbell, C. A.; Gonsalvez, D. J.; Martin, C. H.; Levis, C. A.

1986-01-01

Two search techniques are considered for solving satellite synthesis problems. Neither is likely to find a globally optimal solution. In order to determine which method performs better and what factors affect their performance, an experiment is designed and the same problem is solved under a variety of starting solution configuration-algorithm combinations. Since there is no randomization in the experiment, results of practical, rather than statistical, significance are presented. Implementation of a cyclic coordinate search procedure clearly finds better synthesis solutions than implementation of a gradient search procedure does with the objective of maximizing the minimum C/I ratio computed at test points on the perimeters of the intended service areas. The length of the available orbital arc and the configuration of the starting solution are shown to affect the quality of the solutions found.

Stateline: Critical Mass

ERIC Educational Resources Information Center

Christie, Kathy

2005-01-01

In Physics "critical mass" refers to the minimum amount of fissionable material required to sustain a chain reaction. The adoption of state education policy isn't often equated with this concept, but occasionally solutions and ideas seem to gather around a common problem. If the solution at hand is simple, easily understood, and…

PDS Work at a Small University: Solutions to Common Problems

ERIC Educational Resources Information Center

Mills, Lynne

2010-01-01

Small universities deal with two primary issues when beginning to use the Professional Development School model: Adequate Funding and Faculty Support. Possible solutions are discussed, including ways to provide adequate funding through grants, enrichment/tutoring programs, reallocation of existing funds, and university priority money, as well as…

Solving Nonlinear Coupled Differential Equations

NASA Technical Reports Server (NTRS)

Mitchell, L.; David, J.

1986-01-01

Harmonic balance method developed to obtain approximate steady-state solutions for nonlinear coupled ordinary differential equations. Method usable with transfer matrices commonly used to analyze shaft systems. Solution to nonlinear equation, with periodic forcing function represented as sum of series similar to Fourier series but with form of terms suggested by equation itself.

Challenges and Solutions When Using Technologies in the Classroom

ERIC Educational Resources Information Center

Johnson, Amy M.; Jacovina, Matthew E.; Russell, Devin G.; Soto, Christian M.

2016-01-01

The purpose of this chapter is to present common challenges faced by educators when attempting to integrate technology in the classroom, and offer potential solutions to those problems. Examination of these issues should be valuable to current and future educators, school administrators, as well as educational technology researchers. The chapter…

Organisational Change: A Solution-Focused Approach

ERIC Educational Resources Information Center

Morgan, Gavin

2016-01-01

This study investigates the effectiveness of a solution-focused approach to organisational change. Planning Alternative Tomorrows with Hope (PATH) is an intervention more commonly applied to individuals. In this study the intervention is used with groups of people working in educational organisations to help manage the change process. The approach…

What's a Parent to Do? Coping with Crisis.

ERIC Educational Resources Information Center

Coleman, Trudy; And Others

This instructional packet is one of a series of five modules that emphasize a systematic decision-making model for common problematic situations. The steps of the model are identifying the problem, gathering information, developing and assessing alternatives, implementing a solution, and evaluating and modifying the solution. Aimed at adult basic…

Simultaneously Discovering and Localizing Common Objects in Wild Images.

PubMed

Wang, Zhenzhen; Yuan, Junsong

2018-09-01

Motivated by the recent success of supervised and weakly supervised common object discovery, in this paper, we move forward one step further to tackle common object discovery in a fully unsupervised way. Generally, object co-localization aims at simultaneously localizing objects of the same class across a group of images. Traditional object localization/detection usually trains specific object detectors which require bounding box annotations of object instances, or at least image-level labels to indicate the presence/absence of objects in an image. Given a collection of images without any annotations, our proposed fully unsupervised method is to simultaneously discover images that contain common objects and also localize common objects in corresponding images. Without requiring to know the total number of common objects, we formulate this unsupervised object discovery as a sub-graph mining problem from a weighted graph of object proposals, where nodes correspond to object proposals, and edges represent the similarities between neighbouring proposals. The positive images and common objects are jointly discovered by finding sub-graphs of strongly connected nodes, with each sub-graph capturing one object pattern. The optimization problem can be efficiently solved by our proposed maximal-flow-based algorithm. Instead of assuming that each image contains only one common object, our proposed solution can better address wild images where each image may contain multiple common objects or even no common object. Moreover, our proposed method can be easily tailored to the task of image retrieval in which the nodes correspond to the similarity between query and reference images. Extensive experiments on PASCAL VOC 2007 and Object Discovery data sets demonstrate that even without any supervision, our approach can discover/localize common objects of various classes in the presence of scale, view point, appearance variation, and partial occlusions. We also conduct broad experiments on image retrieval benchmarks, Holidays and Oxford5k data sets, to show that our proposed method, which considers both the similarity between query and reference images and also similarities among reference images, can help to improve the retrieval results significantly.

Knowledge Of Maintenance Intravenous Fluid Therapy In Acutely Ill Hospitalized Children Among Residents.

PubMed

Haque, Anwarul; Mirza, Sadiq; Jafri, Sidra Kaleem; Naseem, Faizia; Khan, Khalid Mahmood; Afzal, Muhammad Faheem; Hamid, Muhammad Haroon

2016-01-01

Isotonic saline is recommended as maintenance intravenous fluid therapy (MIVFT) for most of the acutely ill hospitalized children. The aim of this study is to assess the current knowledge of paediatric residents regarding the selection of MIVFT in hospitalized children. We conducted a paper-based questionnaire survey to paediatric residents from ten centres asking selection of MIVFT in four common clinical scenarios in 6-month and 10-year old patients as well as monitoring of fluid balance and electrolyte. 445 responses were collected (>90% response rate). Majority [78.3% (n=348)] of them were FCPS-trainees. The 0.9%, 0.45% and 0.2% solution were selected by 45.8%, 43.98% and 10.92% respectively. The isotonic and hypotonic solution was prescribed in 6- mo (35.22% vs. 64.76% [p<0.001]) and 10-year (54.49% vs. 44.98%) in four different clinical scenarios respectively. 0.45% solution was most commonly prescribed MIVFT in pneumonia (50.22%) and meningitis (45.39%) and 0.9% solution was most commonly selected in acute gastroenteritis (55.05%) and post-operative patients (51.23%). Fluid balance and electrolyte monitoring were selected by 96.9% and 55.7% respondents respectively. Our survey reports that more than fifty percent of paediatric residents have inadequate knowledge about maintenance intravenous fluid therapy in acutely ill hospitalized children.

Middleware Evaluation and Benchmarking for Use in Mission Operations Centers

NASA Technical Reports Server (NTRS)

Antonucci, Rob; Waktola, Waka

2005-01-01

Middleware technologies have been promoted as timesaving, cost-cutting alternatives to the point-to-point communication used in traditional mission operations systems. However, missions have been slow to adopt the new technology. The lack of existing middleware-based missions has given rise to uncertainty about middleware's ability to perform in an operational setting. Most mission architects are also unfamiliar with the technology and do not know the benefits and detriments to architectural choices - or even what choices are available. We will present the findings of a study that evaluated several middleware options specifically for use in a mission operations system. We will address some common misconceptions regarding the applicability of middleware-based architectures, and we will identify the design decisions and tradeoffs that must be made when choosing a middleware solution. The Middleware Comparison and Benchmark Study was conducted at NASA Goddard Space Flight Center to comprehensively evaluate candidate middleware products, compare and contrast the performance of middleware solutions with the traditional point- to-point socket approach, and assess data delivery and reliability strategies. The study focused on requirements of the Global Precipitation Measurement (GPM) mission, validating the potential use of middleware in the GPM mission ground system. The study was jointly funded by GPM and the Goddard Mission Services Evolution Center (GMSEC), a virtual organization for providing mission enabling solutions and promoting the use of appropriate new technologies for mission support. The study was broken into two phases. To perform the generic middleware benchmarking and performance analysis, a network was created with data producers and consumers passing data between themselves. The benchmark monitored the delay, throughput, and reliability of the data as the characteristics were changed. Measurements were taken under a variety of topologies, data demands, and data characteristics, using several middleware products. All results were compared to systems using traditional point-to-point socket communication. By comparing performance results under Merent settings, inferences could be made about each middleware's ability to meet certain requirements of the GPM mission. The second phase simulated a middleware-based mission operations center. Actual mission support tools were either used or simulated to create real world demands on the middleware. Network and computer demands were watched closely to verify that no specific idiosyncrasies of mission operations activities would prove unsupportable by the middleware. In our presentation, we will address some commonly accepted misconceptions concerning middleware in mission support architectures. Specifically, we will focus on the perception that middleware solutions are too slow or impose too much overhead for real-time mission operations, and that middleware solutions are too expensive for small

Human perspectives and conservation of grizzly bears in Banff National Park, Canada.

PubMed

Chamberlain, Emily C; Rutherford, Murray B; Gibeau, Michael L

2012-06-01

Some conservation initiatives provoke intense conflict among stakeholders. The need for action, the nature of the conservation measures, and the effects of these measures on human interests may be disputed. Tools are needed to depolarize such situations, foster understanding of the perspectives of people involved, and find common ground. We used Q methodology to explore stakeholders' perspectives on conservation and management of grizzly bears (Ursus arctos horribilis) in Banff National Park and the Bow River watershed of Alberta, Canada. Twenty-nine stakeholders participated in the study, including local residents, scientists, agency employees, and representatives of nongovernmental conservation organizations and other interest groups. Participants rank ordered a set of statements to express their opinions on the problems of grizzly bear management (I-IV) and a second set of statements on possible solutions to the problems (A-C). Factor analysis revealed that participants held 4 distinct views of the problems: individuals associated with factor I emphasized deficiencies in goals and plans; those associated with factor II believed that problems had been exaggerated; those associated with factor III blamed institutional flaws such as disjointed management and inadequate resources; and individuals associated with factor IV blamed politicized decision making. There were 3 distinct views about the best solutions to the problems: individuals associated with factor A called for increased conservation efforts; those associated with factor B wanted reforms in decision-making processes; and individuals associated with factor C supported active landscape management. We connected people's definitions of the problem with their preferred solutions to form 5 overall problem narratives espoused by groups in the study: the problem is deficient goals and plans, the solution is to prioritize conservation efforts (planning-oriented conservation advocates); the problem is flawed institutions, the solution is to prioritize conservation efforts (institutionally-oriented conservation advocates); the problems have been exaggerated, but there is a need to improve decision-making processes (optimistic decision-process reformers); the problems have been exaggerated, but managers should more actively manage the landscape (optimistic landscape managers); and the problem is politicized decision making, solutions vary (democratizers). Although these 5 groups differed on many issues, they agreed that the population of grizzly bears is vulnerable to extirpation, human use of the area should be designed around ecological constraints, and more inclusive decision-making processes are needed. We used our results to inform a series of workshops in which stakeholders developed and agreed on new management strategies that were implemented by Parks Canada. Our research demonstrates the usefulness of Q method to illuminate people's perspectives and identify common ground in settings where conservation is contested. ©2012 Society for Conservation Biology.

Modular VO oriented Java EE service deployer

NASA Astrophysics Data System (ADS)

Molinaro, Marco; Cepparo, Francesco; De Marco, Marco; Knapic, Cristina; Apollo, Pietro; Smareglia, Riccardo

2014-07-01

The International Virtual Observatory Alliance (IVOA) has produced many standards and recommendations whose aim is to generate an architecture that starts from astrophysical resources, in a general sense, and ends up in deployed consumable services (that are themselves astrophysical resources). Focusing on the Data Access Layer (DAL) system architecture, that these standards define, in the last years a web based application has been developed and maintained at INAF-OATs IA2 (Italian National institute for Astrophysics - Astronomical Observatory of Trieste, Italian center of Astronomical Archives) to try to deploy and manage multiple VO (Virtual Observatory) services in a uniform way: VO-Dance. However a set of criticalities have arisen since when the VO-Dance idea has been produced, plus some major changes underwent and are undergoing at the IVOA DAL layer (and related standards): this urged IA2 to identify a new solution for its own service layer. Keeping on the basic ideas from VO-Dance (simple service configuration, service instantiation at call time and modularity) while switching to different software technologies (e.g. dismissing Java Reflection in favour of Enterprise Java Bean, EJB, based solution), the new solution has been sketched out and tested for feasibility. Here we present the results originating from this test study. The main constraints for this new project come from various fields. A better homogenized solution rising from IVOA DAL standards: for example the new DALI (Data Access Layer Interface) specification that acts as a common interface system for previous and oncoming access protocols. The need for a modular system where each component is based upon a single VO specification allowing services to rely on common capabilities instead of homogenizing them inside service components directly. The search for a scalable system that takes advantage from distributed systems. The constraints find answer in the adopted solutions hereafter sketched. The development of the new system using Java Enterprise technologies can better benefit from existing libraries to build up the single tokens implementing the IVOA standards. Each component can be built from single standards and each deployed service (i.e. service components instantiations) can consume the other components' exposed methods and services without the need of homogenizing them in dedicated libraries. Scalability can be achieved in an easier way by deploying components or sets of services on a distributed environment and using JNDI (Java Naming and Directory Interface) and RMI (Remote Method Invocation) technologies. Single service configuration will not be significantly different from the VO-Dance solution given that Java class instantiation that benefited from Java Reflection will only be moved to Java EJB pooling (and not, e.g. embedded in bundles for subsequent deployment).

Systemic mastocytosis: CT and US features of abdominal manifestations.

PubMed

Avila, N A; Ling, A; Worobec, A S; Mican, J M; Metcalfe, D D

1997-02-01

To study the imaging findings in patients with systemic mastocytosis and to correlate the findings with the severity of disease on the basis of an established classification system. Pathologic findings, when available, were correlated with imaging findings. Computed tomographic (CT) and ultrasound (US) scans and corresponding pathologic findings, when available, were retrospectively reviewed in 27 patients with systemic mastocytosis. Only five (19%) of the patients in our series had normal abdominal CT and/or US examination results. Common abdominal imaging findings associated with systemic mastocytosis were hepatosplenomegaly, retroperitoneal adenopathy, periportal adenopathy, mesenteric adenopathy, thickening of the omentum and the mesentery, and ascites. Less common findings included hepatofugal portal venous flow, Budd-Chiari syndrome, cavernous transformation of the portal vein, ovarian mass, and complications such as chloroma. The findings were more common in patients with category II and those with category III disease. Abdominal findings at CT and US are common in patients with systemic mastocytosis. Although the findings in patients with systemic mastocytosis are not specific to the disease, they are useful in directing further studies for diagnostic confirmation and in estimating the extent of systemic involvement.

Contact Lens Solutions and Contact Lens Discomfort: Examining the Correlations Between Solution Components, Keratitis, and Contact Lens Discomfort.

PubMed

Kuc, Christopher J; Lebow, Kenneth A

2018-06-13

This article will examine the current literature, as it relates to contact lens discomfort (CLD) secondary to contact lens solutions. The reader will better understand the characteristics of contact lenses, as they uniquely interact with each type of contact lens solution and also gain a better comprehension of the components of contact lens solution such as preservatives, surfactants, and chelating agents, which may contribute to discomfort. By investigating corneal staining theory and the mechanisms that contribute to its presence, the reader will gain insight into this clinical finding, which relates to selection of contact lens solutions. The FDA standards for testing solutions and how this relates to contact lens keratitis will also be appraised in regards to current ISO recommendations. Finally, better selection of multipurpose contact lens solution (MPS) and hydrogen peroxide-based solutions for patients should be accessible to the clinician based on this review and preexisting clinical findings or diagnoses. A review of current published literature from peer reviewed journals and online journals was conducted to gain an understanding of contact lens solution's impact on contact lens discomfort. Many studies have been conducted comparing comfort between various types of contact lens solutions. It is challenging to decipher this information and apply it clinically when selecting solutions for patients. By comparing solution components, how contact lens solutions interact with different types of lenses, keratitis related to contact lenses, and preexisting ocular conditions, this review will improve a clinician's ability to eliminate CLD.

The Goldilocks contract: The synergistic benefits of combining structure and autonomy for persistence, creativity, and cooperation.

PubMed

Chou, Eileen Y; Halevy, Nir; Galinsky, Adam D; Murnighan, J Keith

2017-09-01

Contracts are commonly used to regulate a wide range of interactions and relationships. Yet relying on contracts as a mechanism of control often comes at a cost to motivation. Integrating theoretical perspectives from psychology, economics, and organizational theory, we explore this control-motivation dilemma inherent in contracts and present the Contract-Autonomy-Motivation-Performance-Structure (CAMPS) model, which highlights the synergistic benefits of combining structure and autonomy. The model proposes that subtle reductions in the specificity of a contract's language can boost autonomy, which increases intrinsic motivation and improves a range of desirable behaviors. Nine field and laboratory experiments found that less specific contracts increased task persistence, creativity, and cooperation, both immediately and longitudinally, because they boosted autonomy and intrinsic motivation. These positive effects, however, only occurred when contracts provided sufficient structure. Furthermore, the effects were limited to control-oriented clauses (i.e., legal clauses), and did not extend to coordination-oriented clauses (i.e., technical clauses). That is, there were synergistic benefits when a contract served as a scaffold that combined structure with general clauses. Overall, the current model and experiments identify a low-cost solution to the common problem of regulating social relationships: finding the right amount of contract specificity promotes desirable outcomes, including behaviors that are notoriously difficult to contract. The CAMPS model and the current set of empirical findings explain why, when, and how contracts can be used as an effective motivational tool. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Protein Flexibility Facilitates Quaternary Structure Assembly and Evolution

PubMed Central

Marsh, Joseph A.; Teichmann, Sarah A.

2014-01-01

The intrinsic flexibility of proteins allows them to undergo large conformational fluctuations in solution or upon interaction with other molecules. Proteins also commonly assemble into complexes with diverse quaternary structure arrangements. Here we investigate how the flexibility of individual protein chains influences the assembly and evolution of protein complexes. We find that flexibility appears to be particularly conducive to the formation of heterologous (i.e., asymmetric) intersubunit interfaces. This leads to a strong association between subunit flexibility and homomeric complexes with cyclic and asymmetric quaternary structure topologies. Similarly, we also observe that the more nonhomologous subunits that assemble together within a complex, the more flexible those subunits tend to be. Importantly, these findings suggest that subunit flexibility should be closely related to the evolutionary history of a complex. We confirm this by showing that evolutionarily more recent subunits are generally more flexible than evolutionarily older subunits. Finally, we investigate the very different explorations of quaternary structure space that have occurred in different evolutionary lineages. In particular, the increased flexibility of eukaryotic proteins appears to enable the assembly of heteromeric complexes with more unique components. PMID:24866000

Individual differences in mental rotation: what does gesture tell us?

PubMed

Göksun, Tilbe; Goldin-Meadow, Susan; Newcombe, Nora; Shipley, Thomas

2013-05-01

Gestures are common when people convey spatial information, for example, when they give directions or describe motion in space. Here, we examine the gestures speakers produce when they explain how they solved mental rotation problems (Shepard and Meltzer in Science 171:701-703, 1971). We asked whether speakers gesture differently while describing their problems as a function of their spatial abilities. We found that low-spatial individuals (as assessed by a standard paper-and-pencil measure) gestured more to explain their solutions than high-spatial individuals. While this finding may seem surprising, finer-grained analyses showed that low-spatial participants used gestures more often than high-spatial participants to convey "static only" information but less often than high-spatial participants to convey dynamic information. Furthermore, the groups differed in the types of gestures used to convey static information: high-spatial individuals were more likely than low-spatial individuals to use gestures that captured the internal structure of the block forms. Our gesture findings thus suggest that encoding block structure may be as important as rotating the blocks in mental spatial transformation.

Protein denaturation in vacuo: intrinsic unfolding pathways associated with the native tertiary structure of lysozyme

NASA Astrophysics Data System (ADS)

Arteca, Gustavo A.; Tapia, O.

Using computer-simulated molecular dynamics, we study the effect of sequence mutation on the unfolding mechanism of a native fold. The system considered is the native fold of hen egg-white lysozyme, exposed to centrifugal unfolding in vacuo. This unfolding bias elicits configurational transitions that imitate the behaviour of anhydrous proteins diffusing after electrospraying from neutral-pH solutions. By changing the sequences threaded onto the native fold of lysozyme, we probe the role of disulfide bridges and the effect of a global mutation. We find that the initial denaturing steps share common characteristics for the tested sequences. Recurrent features are: (i) the presence of dumbbell conformers with significant residual secondary structure, (ii) the ubiquitous formation of hairpins and two-stranded β-sheets regardless of disulfide bridges, and (iii) an unfolding pattern where the reduction in folding complexity is highly correlated with the decrease in chain compactness. These findings appear to be intrinsic to the shape of the native fold, suggesting that similar unfolding pathways may be accessible to many protein sequences.

The Teaching of General Solution Methods to Pattern Finding Problems through Focusing on an Evaluation and Improvement Process.

ERIC Educational Resources Information Center

Ishida, Junichi

1997-01-01

Examines the effects of a teaching strategy in which fifth-grade students evaluated the strengths or weaknesses of solution methods to pattern finding problems, including an experimental and control group each consisting of 34 elementary students, in Japan. The experimental group showed a significantly better performance on the retention test…

On new classes of solutions of nonlinear partial differential equations in the form of convergent special series

NASA Astrophysics Data System (ADS)

Filimonov, M. Yu.

2017-12-01

The method of special series with recursively calculated coefficients is used to solve nonlinear partial differential equations. The recurrence of finding the coefficients of the series is achieved due to a special choice of functions, in powers of which the solution is expanded in a series. We obtain a sequence of linear partial differential equations to find the coefficients of the series constructed. In many cases, one can deal with a sequence of linear ordinary differential equations. We construct classes of solutions in the form of convergent series for a certain class of nonlinear evolution equations. A new class of solutions of generalized Boussinesque equation with an arbitrary function in the form of a convergent series is constructed.

Increased resistance of contact lens related bacterial biofilms to antimicrobial activity of soft contact lens care solutions

PubMed Central

Szczotka-Flynn, Loretta B.; Imamura, Yoshifumi; Chandra, Jyotsna; Yu, Changping; Mukherjee, Pranab K.; Pearlman, Eric; Ghannoum, Mahmoud A.

2014-01-01

PURPOSE To determine if clinical and reference strains of Pseudomonas aeruginosa, Serratia marcescens, and Staphylococcus aureus form biofilms on silicone hydrogel contact lenses, and ascertain antimicrobial activities of contact lens care solutions. METHODS Clinical and American Type Culture Collection (ATCC) reference strains of Pseudomonas aeruginosa, Serratia marcescens, and Staphylococcus aureus were incubated with lotrafilcon A lenses under conditions that facilitate biofilm formation. Biofilms were quantified by quantitative culturing (colony forming units, CFUs), and gross morphology and architecture were evaluated using scanning electron microscopy (SEM) and confocal microscopy. Susceptibilities of the planktonic and biofilm growth phases of the bacteria to five common multipurpose contact lens care solutions and one hydrogen peroxide care solution were assessed. RESULTS P. aeruginosa, S. marcescens, and S. aureus reference and clinical strains formed biofilms on lotrafilcon A silicone hydrogel contact lenses, as dense networks of cells arranged in multiple layers with visible extracellular matrix. The biofilms were resistant to commonly used biguanide preserved multipurpose care solutions. P. aeruginosa and S. aureus biofilms were susceptible to a hydrogen peroxide and a polyquaternium preserved care solution, whereas S. marcescens biofilm was resistant to a polyquaternium preserved care solution but susceptible to hydrogen peroxide disinfection. In contrast, the planktonic forms were always susceptible. CONCLUSIONS P. aeruginosa, S. marcescens, and S. aureus form biofilms on lotrafilcon A contact lenses, which in contrast to planktonic cells, are resistant to the antimicrobial activity of several soft contact lens care products. PMID:19654521

Flowing to higher dimensions: a new strongly-coupled phase on M2 branes

DOE PAGES

Pilch, Krzysztof; Tyukov, Alexander; Warner, Nicholas P.

2015-11-24

We describe a one-parameter family of new holographic RG flows that start from AdS 4 × S 7 and go to AdS 5ˆ×B6, where B6 is conformal to a Kahler manifold and AdS 5ˆ is Poincaré AdS 5 with one spatial direction compactified and fibered over B6. The new solutions “flow up dimensions,” going from the (2 + 1)-dimensional conformal field theory on M2 branes in the UV to a (3 + 1)-dimensional field theory on intersecting M5 branes in the infra-red. The M2 branes completely polarize into M5 branes along the flow and the Poincare sections of the AdSmore » 5ˆ are the (3 + 1)-dimensional common intersection of the M5 branes. The emergence of the extra dimension in the infra-red suggests a new strongly-coupled phase of the M2 brane and ABJM theories in which charged solitons are becoming massless. The flow solution is first analyzed by finding a four-dimensional N=2 supersymmetric flow in N=8 gauged supergravity. This is then generalized to a one parameter family of non-supersymmetric flows. The infra-red limit of the solutions appears to be quite singular in four dimensions but the uplift to eleven-dimensional supergravity is remarkable and regular (up to orbifolding). Our construction is a non-trivial application of the recently derived uplift formulae for fluxes, going well beyond the earlier constructions of stationary points solutions. As a result, the eleven-dimensional supersymmetry is also analyzed and shows how, for the supersymmetric flow, the M2-brane supersymmetry in the UV is polarized entirely into M5-brane supersymmetry in the infra-red.« less

A novel signal transduction protein: Combination of solute binding and tandem PAS-like sensor domains in one polypeptide chain: Periplasmic Ligand Binding Protein Dret_0059

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

Wu, R.; Wilton, R.; Cuff, M. E.

We report the structural and biochemical characterization of a novel periplasmic ligand-binding protein, Dret_0059, from Desulfohalobium retbaense DSM 5692, an organism isolated from the Salt Lake Retba in Senegal. The structure of the protein consists of a unique combination of a periplasmic solute binding protein (SBP) domain at the N-terminal and a tandem PAS-like sensor domain at the C-terminal region. SBP domains are found ubiquitously and their best known function is in solute transport across membranes. PAS-like sensor domains are commonly found in signal transduction proteins. These domains are widely observed as parts of many protein architectures and complexes butmore » have not been observed previously within the same polypeptide chain. In the structure of Dret_0059, a ketoleucine moiety is bound to the SBP, whereas a cytosine molecule is bound in the distal PAS-like domain of the tandem PAS-like domain. Differential scanning flourimetry support the binding of ligands observed in the crystal structure. There is significant interaction between the SBP and tandem PAS-like domains, and it is possible that the binding of one ligand could have an effect on the binding of the other. We uncovered three other proteins with this structural architecture in the non-redundant sequence data base, and predict that they too bind the same substrates. The genomic context of this protein did not offer any clues for its function. We did not find any biological process in which the two observed ligands are coupled. The protein Dret_0059 could be involved in either signal transduction or solute transport.« less

Sample distribution in peak mode isotachophoresis

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

Rubin, Shimon; Schwartz, Ortal; Bercovici, Moran, E-mail: mberco@technion.ac.il

We present an analytical study of peak mode isotachophoresis (ITP), and provide closed form solutions for sample distribution and electric field, as well as for leading-, trailing-, and counter-ion concentration profiles. Importantly, the solution we present is valid not only for the case of fully ionized species, but also for systems of weak electrolytes which better represent real buffer systems and for multivalent analytes such as proteins and DNA. The model reveals two major scales which govern the electric field and buffer distributions, and an additional length scale governing analyte distribution. Using well-controlled experiments, and numerical simulations, we verify andmore » validate the model and highlight its key merits as well as its limitations. We demonstrate the use of the model for determining the peak concentration of focused sample based on known buffer and analyte properties, and show it differs significantly from commonly used approximations based on the interface width alone. We further apply our model for studying reactions between multiple species having different effective mobilities yet co-focused at a single ITP interface. We find a closed form expression for an effective-on rate which depends on reactants distributions, and derive the conditions for optimizing such reactions. Interestingly, the model reveals that maximum reaction rate is not necessarily obtained when the concentration profiles of the reacting species perfectly overlap. In addition to the exact solutions, we derive throughout several closed form engineering approximations which are based on elementary functions and are simple to implement, yet maintain the interplay between the important scales. Both the exact and approximate solutions provide insight into sample focusing and can be used to design and optimize ITP-based assays.« less

A novel signal transduction protein: Combination of solute binding and tandem PAS-like sensor domains in one polypeptide chain.

PubMed

Wu, R; Wilton, R; Cuff, M E; Endres, M; Babnigg, G; Edirisinghe, J N; Henry, C S; Joachimiak, A; Schiffer, M; Pokkuluri, P R

2017-04-01

We report the structural and biochemical characterization of a novel periplasmic ligand-binding protein, Dret_0059, from Desulfohalobium retbaense DSM 5692, an organism isolated from Lake Retba, in Senegal. The structure of the protein consists of a unique combination of a periplasmic solute binding protein (SBP) domain at the N-terminal and a tandem PAS-like sensor domain at the C-terminal region. SBP domains are found ubiquitously, and their best known function is in solute transport across membranes. PAS-like sensor domains are commonly found in signal transduction proteins. These domains are widely observed as parts of many protein architectures and complexes but have not been observed previously within the same polypeptide chain. In the structure of Dret_0059, a ketoleucine moiety is bound to the SBP, whereas a cytosine molecule is bound in the distal PAS-like domain of the tandem PAS-like domain. Differential scanning flourimetry support the binding of ligands observed in the crystal structure. There is significant interaction between the SBP and tandem PAS-like domains, and it is possible that the binding of one ligand could have an effect on the binding of the other. We uncovered three other proteins with this structural architecture in the non-redundant sequence data base, and predict that they too bind the same substrates. The genomic context of this protein did not offer any clues for its function. We did not find any biological process in which the two observed ligands are coupled. The protein Dret_0059 could be involved in either signal transduction or solute transport. © 2017 The Protein Society.

Molecular Dynamics in Physiological Solutions: Force Fields, Alkali Metal Ions, and Ionic Strength.

PubMed

Zhang, Chao; Raugei, Simone; Eisenberg, Bob; Carloni, Paolo

2010-07-13

The monovalent ions Na(+) and K(+) and Cl(-) are present in any living organism. The fundamental thermodynamic properties of solutions containing such ions is given as the excess (electro-)chemical potential differences of single ions at finite ionic strength. This quantity is key for many biological processes, including ion permeation in membrane ion channels and DNA-protein interaction. It is given by a chemical contribution, related to the ion activity, and an electric contribution, related to the Galvani potential of the water/air interface. Here we investigate molecular dynamics based predictions of these quantities by using a variety of ion/water force fields commonly used in biological simulation, namely the AMBER (the newly developed), CHARMM, OPLS, Dang95 with TIP3P, and SPC/E water. Comparison with experiment is made with the corresponding values for salts, for which data are available. The calculations based on the newly developed AMBER force field with TIP3P water agrees well with experiment for both KCl and NaCl electrolytes in water solutions, as previously reported. The simulations based on the CHARMM-TIP3P and Dang95-SPC/E force fields agree well for the KCl and NaCl solutions, respectively. The other models are not as accurate. Single cations excess (electro-)chemical potential differences turn out to be similar for all the force fields considered here. In the case of KCl, the calculated electric contribution is consistent with higher level calculations. Instead, such agreement is not found with NaCl. Finally, we found that the calculated activities for single Cl(-) ions turn out to depend clearly on the type of counterion used, with all the force fields investigated. The implications of these findings for biomolecular systems are discussed.

Flowing to higher dimensions: a new strongly-coupled phase on M2 branes

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

Pilch, Krzysztof; Tyukov, Alexander; Warner, Nicholas P.

We describe a one-parameter family of new holographic RG flows that start from AdS 4 × S 7 and go to AdS 5ˆ×B6, where B6 is conformal to a Kahler manifold and AdS 5ˆ is Poincaré AdS 5 with one spatial direction compactified and fibered over B6. The new solutions “flow up dimensions,” going from the (2 + 1)-dimensional conformal field theory on M2 branes in the UV to a (3 + 1)-dimensional field theory on intersecting M5 branes in the infra-red. The M2 branes completely polarize into M5 branes along the flow and the Poincare sections of the AdSmore » 5ˆ are the (3 + 1)-dimensional common intersection of the M5 branes. The emergence of the extra dimension in the infra-red suggests a new strongly-coupled phase of the M2 brane and ABJM theories in which charged solitons are becoming massless. The flow solution is first analyzed by finding a four-dimensional N=2 supersymmetric flow in N=8 gauged supergravity. This is then generalized to a one parameter family of non-supersymmetric flows. The infra-red limit of the solutions appears to be quite singular in four dimensions but the uplift to eleven-dimensional supergravity is remarkable and regular (up to orbifolding). Our construction is a non-trivial application of the recently derived uplift formulae for fluxes, going well beyond the earlier constructions of stationary points solutions. As a result, the eleven-dimensional supersymmetry is also analyzed and shows how, for the supersymmetric flow, the M2-brane supersymmetry in the UV is polarized entirely into M5-brane supersymmetry in the infra-red.« less

Exact soliton of (2 + 1)-dimensional fractional Schrödinger equation

NASA Astrophysics Data System (ADS)

Rizvi, S. T. R.; Ali, K.; Bashir, S.; Younis, M.; Ashraf, R.; Ahmad, M. O.

2017-07-01

The nonlinear fractional Schrödinger equation is the basic equation of fractional quantum mechanics introduced by Nick Laskin in 2002. We apply three tools to solve this mathematical-physical model. First, we find the solitary wave solutions including the trigonometric traveling wave solutions, bell and kink shape solitons using the F-expansion and Improve F-expansion method. We also obtain the soliton solution, singular soliton solutions, rational function solution and elliptic integral function solutions, with the help of the extended trial equation method.

Non-uniform solute segregation at semi-coherent metal/oxide interfaces

DOE PAGES

Choudhury, Samrat; Aguiar, Jeffery A.; Fluss, Michael J.; ...

2015-08-26

The properties and performance of metal/oxide nanocomposites are governed by the structure and chemistry of the metal/oxide interfaces. Here we report an integrated theoretical and experimental study examining the role of interfacial structure, particularly misfit dislocations, on solute segregation at a metal/oxide interface. We find that the local oxygen environment, which varies significantly between the misfit dislocations and the coherent terraces, dictates the segregation tendency of solutes to the interface. Depending on the nature of the solute and local oxygen content, segregation to misfit dislocations can change from attraction to repulsion, revealing the complex interplay between chemistry and structure atmore » metal/oxide interfaces. These findings indicate that the solute chemistry at misfit dislocations is controlled by the dislocation density and oxygen content. As a result, fundamental thermodynamic concepts – the Hume-Rothery rules and the Ellingham diagram – qualitatively predict the segregation behavior of solutes to such interfaces, providing design rules for novel interfacial chemistries.« less

Root finding in the complex plane for seismo-acoustic propagation scenarios with Green's function solutions.

PubMed

McCollom, Brittany A; Collis, Jon M

2014-09-01

A normal mode solution to the ocean acoustic problem of the Pekeris waveguide with an elastic bottom using a Green's function formulation for a compressional wave point source is considered. Analytic solutions to these types of waveguide propagation problems are strongly dependent on the eigenvalues of the problem; these eigenvalues represent horizontal wavenumbers, corresponding to propagating modes of energy. The eigenvalues arise as singularities in the inverse Hankel transform integral and are specified by roots to a characteristic equation. These roots manifest themselves as poles in the inverse transform integral and can be both subtle and difficult to determine. Following methods previously developed [S. Ivansson et al., J. Sound Vib. 161 (1993)], a root finding routine has been implemented using the argument principle. Using the roots to the characteristic equation in the Green's function formulation, full-field solutions are calculated for scenarios where an acoustic source lies in either the water column or elastic half space. Solutions are benchmarked against laboratory data and existing numerical solutions.

Common solutions for power, communication and robustness in operations of large measurement networks within Research Infrastructures

NASA Astrophysics Data System (ADS)

Huber, Robert; Beranzoli, Laura; Fiebig, Markus; Gilbert, Olivier; Laj, Paolo; Mazzola, Mauro; Paris, Jean-Daniel; Pedersen, Helle; Stocker, Markus; Vitale, Vito; Waldmann, Christoph

2017-04-01

European Environmental Research Infrastructures (RI) frequently comprise in situ observatories from large-scale networks of platforms or sites to local networks of various sensors. Network operation is usually a cumbersome aspect of these RIs facing specific technological problems related to operations in remote areas, maintenance of the network, transmission of observation values, etc.. Robust inter-connection within and across these networks is still at infancy level and the burden increases with remoteness of the station, harshness of environmental conditions, and unavailability of classic communication systems, which is a common feature here. Despite existing RIs having developed ad-hoc solutions to overcome specific problems and innovative technologies becoming available, no common approach yet exists. Within the European project ENVRIplus, a dedicated work package aims to stimulate common network operation technologies and approaches in terms of power supply and storage, robustness, and data transmission. Major objectives of this task are to review existing technologies and RI requirements, propose innovative solutions and evaluate the standardization potential prior to wider deployment across networks. Focus areas within these efforts are: improving energy production and storage units, testing robustness of RI equipment towards extreme conditions as well as methodologies for robust data transmission. We will introduce current project activities which are coordinated at various levels including the engineering as well as the data management perspective, and explain how environmental RIs can benefit from the developments.

Ineffective higher derivative black hole hair

NASA Astrophysics Data System (ADS)

Goldstein, Kevin; Mashiyane, James Junior

2018-01-01

Inspired by the possibility that the Schwarzschild black hole may not be the unique spherically symmetric vacuum solution to generalizations of general relativity, we consider black holes in pure fourth order higher derivative gravity treated as an effective theory. Such solutions may be of interest in addressing the issue of higher derivative hair or during the later stages of black hole evaporation. Non-Schwarzschild solutions have been studied but we have put earlier results on a firmer footing by finding a systematic asymptotic expansion for the black holes and matching them with known numerical solutions obtained by integrating out from the near-horizon region. These asymptotic expansions can be cast in the form of trans-series expansions which we conjecture will be a generic feature of non-Schwarzschild higher derivative black holes. Excitingly we find a new branch of solutions with lower free energy than the Schwarzschild solution, but as found in earlier work, solutions only seem to exist for black holes with large curvatures, meaning that one should not generically neglect even higher derivative corrections. This suggests that one effectively recovers the nonhair theorems in this context.

One thousand and one bubbles

NASA Astrophysics Data System (ADS)

Ávila, Jesús; Ramírez, Pedro F.; Ruipérez, Alejandro

2018-01-01

We propose a novel strategy that permits the construction of completely general five-dimensional microstate geometries on a Gibbons-Hawking space. Our scheme is based on two steps. First, we rewrite the bubble equations as a system of linear equations that can be easily solved. Second, we conjecture that the presence or absence of closed timelike curves in the solution can be detected through the evaluation of an algebraic relation. The construction we propose is systematic and covers the whole space of parameters, so it can be applied to find all five-dimensional BPS microstate geometries on a Gibbons-Hawking base. As a first result of this approach, we find that the spectrum of scaling solutions becomes much larger when non-Abelian fields are present. We use our method to describe several smooth horizonless multicenter solutions with the asymptotic charges of three-charge (Abelian and non-Abelian) black holes. In particular, we describe solutions with the centers lying on lines and circles that can be specified with exact precision. We show the power of our method by explicitly constructing a 50-center solution. Moreover, we use it to find the first smooth five-dimensional microstate geometries with arbitrarily small angular momentum.

Identification of the connections in biologically inspired neural networks

NASA Technical Reports Server (NTRS)

Demuth, H.; Leung, K.; Beale, M.; Hicklin, J.

1990-01-01

We developed an identification method to find the strength of the connections between neurons from their behavior in small biologically-inspired artificial neural networks. That is, given the network external inputs and the temporal firing pattern of the neurons, we can calculate a solution for the strengths of the connections between neurons and the initial neuron activations if a solution exists. The method determines directly if there is a solution to a particular neural network problem. No training of the network is required. It should be noted that this is a first pass at the solution of a difficult problem. The neuron and network models chosen are related to biology but do not contain all of its complexities, some of which we hope to add to the model in future work. A variety of new results have been obtained. First, the method has been tailored to produce connection weight matrix solutions for networks with important features of biological neural (bioneural) networks. Second, a computationally efficient method of finding a robust central solution has been developed. This later method also enables us to find the most consistent solution in the presence of noisy data. Prospects of applying our method to identify bioneural network connections are exciting because such connections are almost impossible to measure in the laboratory. Knowledge of such connections would facilitate an understanding of bioneural networks and would allow the construction of the electronic counterparts of bioneural networks on very large scale integrated (VLSI) circuits.

Infinite hierarchy of nonlinear Schrödinger equations and their solutions.

PubMed

Ankiewicz, A; Kedziora, D J; Chowdury, A; Bandelow, U; Akhmediev, N

2016-01-01

We study the infinite integrable nonlinear Schrödinger equation hierarchy beyond the Lakshmanan-Porsezian-Daniel equation which is a particular (fourth-order) case of the hierarchy. In particular, we present the generalized Lax pair and generalized soliton solutions, plane wave solutions, Akhmediev breathers, Kuznetsov-Ma breathers, periodic solutions, and rogue wave solutions for this infinite-order hierarchy. We find that "even- order" equations in the set affect phase and "stretching factors" in the solutions, while "odd-order" equations affect the velocities. Hence odd-order equation solutions can be real functions, while even-order equation solutions are always complex.

Army Communicator. Volume 37, Number 2, Summer 2012

DTIC Science & Technology

2012-01-01

solution will have to meet four criteria: FIPS 140-2 validated crypto; approved data-at-rest; Common Access Card enablement; and, enterprise management...Information Grid. Common Access Cards , Federal Information Processing Standard 140-2 certifications, and software compliance are just a few of the...and Evaluation Command BMC – Brigade Modernization Command CAC – Common Access Card FIPS – Federal Information Processing Standard GIG – Global

Implementing Target Value Design.

PubMed

Alves, Thais da C L; Lichtig, Will; Rybkowski, Zofia K

2017-04-01

An alternative to the traditional way of designing projects is the process of target value design (TVD), which takes different departure points to start the design process. The TVD process starts with the client defining an allowable cost that needs to be met by the design and construction teams. An expected cost in the TVD process is defined through multiple interactions between multiple stakeholders who define wishes and others who define ways of achieving these wishes. Finally, a target cost is defined based on the expected profit the design and construction teams are expecting to make. TVD follows a series of continuous improvement efforts aimed at reaching the desired goals for the project and its associated target value cost. The process takes advantage of rapid cycles of suggestions, analyses, and implementation that starts with the definition of value for the client. In the traditional design process, the goal is to identify user preferences and find solutions that meet the needs of the client's expressed preferences. In the lean design process, the goal is to educate users about their values and advocate for a better facility over the long run; this way owners can help contractors and designers to identify better solutions. This article aims to inform the healthcare community about tools and techniques commonly used during the TVD process and how they can be used to educate and support project participants in developing better solutions to meet their needs now as well as in the future.

Latent profile and cluster analysis of infant temperament: Comparisons across person-centered approaches.

PubMed

Gartstein, Maria A; Prokasky, Amanda; Bell, Martha Ann; Calkins, Susan; Bridgett, David J; Braungart-Rieker, Julia; Leerkes, Esther; Cheatham, Carol L; Eiden, Rina D; Mize, Krystal D; Jones, Nancy Aaron; Mireault, Gina; Seamon, Erich

2017-10-01

There is renewed interest in person-centered approaches to understanding the structure of temperament. However, questions concerning temperament types are not frequently framed in a developmental context, especially during infancy. In addition, the most common person-centered techniques, cluster analysis (CA) and latent profile analysis (LPA), have not been compared with respect to derived temperament types. To address these gaps, we set out to identify temperament types for younger and older infants, comparing LPA and CA techniques. Multiple data sets (N = 1,356; 672 girls, 677 boys) with maternal ratings of infant temperament obtained using the Infant Behavior Questionnaire-Revised (Gartstein & Rothbart, 2003) were combined. All infants were between 3 and 12 months of age (M = 7.85; SD = 3.00). Due to rapid development in the first year of life, LPA and CA were performed separately for younger (n = 731; 3 to 8 months of age) and older (n = 625; 9 to 12 months of age) infants. Results supported 3-profile/cluster solutions as optimal for younger infants, and 5-profile/cluster solutions for the older subsample, indicating considerable differences between early/mid and late infancy. LPA and CA solutions produced relatively comparable types for younger and older infants. Results are discussed in the context of developmental changes unique to the end of the first year of life, which likely account for the present findings. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

A disturbance based control/structure design algorithm

NASA Technical Reports Server (NTRS)

Mclaren, Mark D.; Slater, Gary L.

1989-01-01

Some authors take a classical approach to the simultaneous structure/control optimization by attempting to simultaneously minimize the weighted sum of the total mass and a quadratic form, subject to all of the structural and control constraints. Here, the optimization will be based on the dynamic response of a structure to an external unknown stochastic disturbance environment. Such a response to excitation approach is common to both the structural and control design phases, and hence represents a more natural control/structure optimization strategy than relying on artificial and vague control penalties. The design objective is to find the structure and controller of minimum mass such that all the prescribed constraints are satisfied. Two alternative solution algorithms are presented which have been applied to this problem. Each algorithm handles the optimization strategy and the imposition of the nonlinear constraints in a different manner. Two controller methodologies, and their effect on the solution algorithm, will be considered. These are full state feedback and direct output feedback, although the problem formulation is not restricted solely to these forms of controller. In fact, although full state feedback is a popular choice among researchers in this field (for reasons that will become apparent), its practical application is severely limited. The controller/structure interaction is inserted by the imposition of appropriate closed-loop constraints, such as closed-loop output response and control effort constraints. Numerical results will be obtained for a representative flexible structure model to illustrate the effectiveness of the solution algorithms.

Effect of cations on the solubilization/deposition of triclosan in sediment-water-rhamnolipid system.

PubMed

Chen, Yuanbo; Hu, Yongyou; Guo, Qian; Yan, Jia; Wu, Wenjin

2016-09-01

Cations had great influence on the self-assembly of rhamnolipid, which in turn affected the fate of triclosan. The migration of triclosan from sediment to water benefited its biodegradation but it could be transformed into more toxic compounds. To regulate the fate of triclosan and reduce environmental risks extremely, the effect of four common cations in surface water (Na(+)/K(+)/Ca(2+)/Mg(2+)) on the solubilization/deposition of triclosan in sediment-water-rhamnolipid system was investigated. The interaction among cations, triclosan and rhamnolipid was explored based on self-assembly of rhamnolipid and water solubility of triclosan in rhamnolipid solutions. Results showed that cations had little influence on the fate of triclosan in the absence of rhamnolipid. Cations, especially Ca(2+)/Mg(2+), reduced the critical micelle concentration, micellar size and zeta potential of rhamnolipid solutions. The changes in self-assembly of rhamnolipid with different cations led to the difference of residual rhamnolipid concentration in water, which was nearly invariant with 0.01 M Na(+)/K(+) while decreased significantly with 0.01 M Ca(2+)/Mg(2+). Consequently, water solubility of triclosan in rhamnolipid solutions increased with the addition of Na(+)/K(+) whereas decreased with Ca(2+)/Mg(2+). In sediment-water- rhamnolipid system, triclosan was slightly solubilized from sediment to water with Na(+)/K(+) while deposited in sediment with Ca(2+)/Mg(2+). These findings provided an alternative application of rhamnolipid for the remediation of triclosan-polluted sediment. Copyright © 2016. Published by Elsevier Ltd.

Golden Gait: An Optimization Theory Perspective on Human and Humanoid Walking

PubMed Central

Iosa, Marco; Morone, Giovanni; Paolucci, Stefano

2017-01-01

Human walking is a complex task which includes hundreds of muscles, bones and joints working together to deliver harmonic movements with the need of finding equilibrium between moving forward and maintaining stability. Many different computational approaches have been used to explain human walking mechanisms, from pendular model to fractal approaches. A new perspective can be gained from using the principles developed in the field of Optimization theory and in particularly the branch of Game Theory. In particular we provide a new insight into human walking showing as the trade-off between advancement and equilibrium managed during walking has the same solution of the Ultimatum game, one of the most famous paradigms of game theory, and this solution is the golden ratio. The golden ratio is an irrational number that was found in many biological and natural systems self-organized in a harmonic, asymmetric, and fractal structure. Recently, the golden ratio has also been found as the equilibrium point between two players involved into the Ultimatum Game. It has been suggested that this result can be due to the fact that the golden ratio is perceived as the fairest asymmetric solution by the two players. The golden ratio is also the most common proportion between stance and swing phase of human walking. This approach may explain the importance of harmony in human walking, and provide new perspectives for developing quantitative assessment of human walking, efficient humanoid robotic walkers, and effective neurorobots for rehabilitation. PMID:29311890

Padé approximations for Painlevé I and II transcendents

NASA Astrophysics Data System (ADS)

Novokshenov, V. Yu.

2009-06-01

We use a version of the Fair-Luke algorithm to find the Padé approximate solutions of the Painlevé I and II equations. We find the distributions of poles for the well-known Ablowitz-Segur and Hastings-McLeod solutions of the Painlevé II equation. We show that the Boutroux tritronquée solution of the Painleé I equation has poles only in the critical sector of the complex plane. The algorithm allows checking other analytic properties of the Painlevé transcendents, such as the asymptotic behavior at infinity in the complex plane.

Identifying the role of conservation biology for solving the environmental crisis.

PubMed

Dalerum, Fredrik

2014-11-01

Humans are altering their living environment to an extent that could cause environmental collapse. Promoting change into environmental sustainability is therefore urgent. Despite a rapid expansion in conservation biology, appreciation of underlying causes and identification of long-term solutions have largely been lacking. I summarized knowledge regarding the environmental crisis, and argue that the most important contributions toward solutions come from economy, political sciences, and psychology. Roles of conservation biology include providing environmental protection until sustainable solutions have been found, evaluating the effectiveness of implemented solutions, and providing societies with information necessary to align effectively with environmental values. Because of the potential disciplinary discrepancy between finding long-term solutions and short-term protection, we may face critical trade-offs between allocations of resources toward achieving sustainability. Since biological knowledge is required for such trade-offs, an additional role for conservation biologists may be to provide guidance toward finding optimal strategies in such trade-offs.

Tikekar superdense stars in electric fields

NASA Astrophysics Data System (ADS)

Komathiraj, K.; Maharaj, S. D.

2007-04-01

We present exact solutions to the Einstein-Maxwell system of equations with a specified form of the electric field intensity by assuming that the hypersurface {t=constant} are spheroidal. The solution of the Einstein-Maxwell system is reduced to a recurrence relation with variable rational coefficients which can be solved in general using mathematical induction. New classes of solutions of linearly independent functions are obtained by restricting the spheroidal parameter K and the electric field intensity parameter α. Consequently, it is possible to find exact solutions in terms of elementary functions, namely, polynomials and algebraic functions. Our result contains models found previously including the superdense Tikekar neutron star model [J. Math. Phys. 31, 2454 (1990)] when K=-7 and α=0. Our class of charged spheroidal models generalize the uncharged isotropic Maharaj and Leach solutions [J. Math. Phys. 37, 430 (1996)]. In particular, we find an explicit relationship directly relating the spheroidal parameter K to the electromagnetic field.

9 CFR 96.13 - Uncertified casings; disinfection with hydrochloric acid.

Code of Federal Regulations, 2010 CFR

2010-01-01

...) Disinfect the casings in a solution made as follows: Dissolve 90 pounds common salt in 100 gallons water and... solution shall be discarded unless means are provided for accurately determining the loss of strength. In event means for accurately determining loss of strength are provided it will be permissible to restore...

The Transmission Line as a Simple Example for Introducing Integral Equations to Undergraduates

ERIC Educational Resources Information Center

Rothwell, E. J.

2009-01-01

Integral equations are becoming a common means for describing problems in electromagnetics, and so it is important to expose students to methods for their solution. Typically this is done using examples in antennas, scattering, or electrostatics. Unfortunately, many difficult issues arise in the formulation and solution of the associated…

IMMOBILIZATION OF AQUEOUS PYRENE BY DISSOLVED HUMIC ACID (R822832)

EPA Science Inventory

Abstract

Pyrene is frequently used as a fluorescent probe in the study of solution environments. Purging with nitrogen is a common practice for the elimination of oxygen from solutions, but this procedure leads to the loss of pyrene through carry-over in the nitrogen s...

The Piranha Solution: Monitoring and Protection of Proprietary System Intangible Assets

ERIC Educational Resources Information Center

Ladwig, Christine; Schwieger, Dana; Clayton, Donald

2017-01-01

The "Piranha Solution"® is a complex and valuable integrated chemical supply inventory management system protected as a trade secret by its asset holder, the Confluence Corporation. The "Piranha" program is the lifeblood of the corporation's growth and success in the chemical supply industry. A common definition of "trade…

Acute skin lesions after surgical procedures: a clinical approach.

PubMed

Borrego, L

2013-11-01

In the hospital setting, dermatologists are often required to evaluate inflammatory skin lesions arising during surgical procedures performed in other departments. These lesions can be of physical or chemical origin. Povidone iodine is the most common reported cause of such lesions. If this antiseptic solution remains in contact with the skin in liquid form for a long period of time, it can give rise to serious irritant contact dermatitis in dependent or occluded areas. Less common causes of skin lesions after surgery include allergic contact dermatitis and burns under the dispersive electrode of the electrosurgical device. Most skin lesions that arise during surgical procedures are due to an incorrect application of antiseptic solutions. Special care must therefore be taken during the use of these solutions and, in particular, they should be allowed to dry. Copyright © 2012 Elsevier España, S.L. and AEDV. All rights reserved.

EAP and LLNP Students: Common Problems and Strategies

ERIC Educational Resources Information Center

Nguyen, Thi Minh Phuong

2010-01-01

As English learners originate from many cultural and language backgrounds, they come to class with different circumstances. This paper examines the backgrounds, common problems and solutions for English for Academic Purposes (EAP) students and Language, Literacy, and Numeracy Programme (LLNP) students. EAP students are from Meridian International…

On Browne's Solution for Oblique Procrustes Rotation

ERIC Educational Resources Information Center

Cramer, Elliot M.

1974-01-01

A form of Browne's (1967) solution of finding a least squares fit to a specified factor structure is given which does not involve solution of an eigenvalue problem. It suggests the possible existence of a singularity, and a simple modification of Browne's computational procedure is proposed. (Author/RC)

Acute toxicity evaluation of proliferol: a dose-escalating, placebo-controlled study in swine.

PubMed

Dagenais, Simon; Wooley, James; Hite, Mark; Green, Robert; Mayer, John

2009-01-01

Prolotherapy is one of the many treatments available for chronic musculoskeletal disorders. A commonly used drug contains dextrose 12.5%, glycerin 12.5%, phenol 1.0%, and lidocaine hydrochloride 0.25% in aqueous solution (recently termed Proliferol). For chronic low back pain, this is injected into lumbosacral ligaments to stimulate connective tissue repair. Despite generally positive clinical results, the toxicity of this drug is not well characterized and was assessed in 48 (24 male, 24 female) Yucatan miniature swine randomly assigned to low (1x), medium (5x), or high (10x) dose or saline placebo. Outcomes included clinical observations, clinical chemistry, hematology, coagulation, urinalysis, toxicokinetics, and full gross and microscopic histopathology after 24 hours or 14 days. Findings attributable to Proliferol after 24 hours included dose-response elevations in alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase, and creatine kinase, which returned to normal after 14 days. There were no remarkable findings in hematology, coagulation, or urinalysis. Urine concentrations of lidocaine and phenol both peaked after 8 hours. Histopathology findings after 24 hours included hemorrhage, inflammation, necrosis, and vascular changes in the ligaments and adjacent soft tissues at the sites of injection. After 14 days, there was evidence of repair under way, with fibrosis and skeletal muscle regeneration at the injection sites.

The association between tolerance for ambiguity and fear of negative evaluation: A study of engineering technology capstone courses

NASA Astrophysics Data System (ADS)

Dubikovsky, Sergey I.

For many students in engineering and engineering technology programs in the US, senior capstone design courses require students to form a team, define a problem, and find a feasible technical solution to address this problem. Students must integrate the knowledge and skills acquired during their studies at the college or university level. These truly integrative design activities do not have a single "correct" solution. Instead, there is an array of solutions, many of which could be used to achieve the final result. This ambiguity can cause students to experience anxiety during the projects. This study examined the main topics: • To what extent is a social anxiety (measured as fear of negative evaluation) related to tolerance for ambiguity in senior engineering capstone courses? • How does exposure to ambiguity prior to and during capstone courses affect tolerance for ambiguity? The study looked at the standard educational practices to see if they have unintended consequences, such a social anxiety in dealing with ambiguity. Those consequences are highly undesirable because they reduce students' learning. It was hypothesized that the lecture-based approaches that are more common in the first three years of study would not prepare students for self-directed capstone courses because the students would rarely have experienced problem-based learning before. The study used a quantitative approach and examined students' perceptions of their tolerance for ambiguity, and social anxiety before and after their senior capstone design experience. A survey instrument was adapted to measure exposure to ambiguity, which was studied as a potential moderator of the relationship between social anxiety and tolerance for ambiguity. The study indicated that social anxiety, as measured by fear of negative evaluation, does not play a major role in capstone courses. The second finding is that a single course, even if it was administered as a problem-based senior class, failed to increase students' tolerance for ambiguity. Students with low tolerance have more problems with ambiguity, whereas students with high tolerance can more easily endure changes and find it easier to act in the absence of complete information. The third important finding was that exposure to ambiguity prior to capstone courses does affect tolerance for ambiguity while controlling for instructor and if exposure to ambiguity is included as a moderator. It was not in the scope of this study to explore the effect of instructor more deeply, but this provides a direction for future research, especially in this time of expanding implementation of project- and problem-based learning methods in technical curricula.

Modeling of electrical capacitance tomography with the use of complete electrode model

NASA Astrophysics Data System (ADS)

Fang, Weifu

2016-10-01

We introduce the complete electrode model in the modeling of electrical capacitance tomography (ECT), which extends the model with the commonly used model for electrodes. We show that the solution of the complete electrode model approaches the solution of the corresponding common electrode model as the impedance effect on the electrodes vanishes. We also derive the nonlinear relation between capacitance and permitivity and the sensitivity maps with respect to both the permittivity and the impedance constants, and present a finite difference scheme in polar coordinates for the case of circular ECT sensors that retains the continuity of displacement current with piecewise-constant permitivities.

Measurement of the equilibrium relative humidity for common precipitant concentrations: facilitating controlled dehydration experiments.

PubMed

Wheeler, Matthew J; Russi, Silvia; Bowler, Michael G; Bowler, Matthew W

2012-01-01

The dehydration of crystals of macromolecules has long been known to have the potential to increase their diffraction quality. A number of methods exist to change the relative humidity that surrounds crystals, but for reproducible results, with complete characterization of the changes induced, a precise humidity-control device coupled with an X-ray source is required. The first step in these experiments is to define the relative humidity in equilibrium with the mother liquor of the system under study; this can often be quite time-consuming. In order to reduce the time spent on this stage of the experiment, the equilibrium relative humidity for a range of concentrations of the most commonly used precipitants has been measured. The relationship between the precipitant solution and equilibrium relative humidity is explained by Raoult's law for the equilibrium vapour pressure of water above a solution. The results also have implications for the choice of cryoprotectant and solutions used to dehydrate crystals. For the most commonly used precipitants (10-30% PEG 2000-8000), the starting point will be a relative humidity of 99.5%. © 2012 International Union of Crystallography. All rights reserved.

Solute transport in aquifers: The comeback of the advection dispersion equation and the First Order Approximation

NASA Astrophysics Data System (ADS)

Fiori, A.; Zarlenga, A.; Jankovic, I.; Dagan, G.

2017-12-01

Natural gradient steady flow of mean velocity U takes place in heterogeneous aquifers of random logconductivity Y = lnK , characterized by the normal univariate PDF f(Y) and autocorrelation ρY, of variance σY2 and horizontal integral scale I. Solute transport is quantified by the Breakthrough Curve (BTC) M at planes at distance x from the injection plane. The study builds on the extensive 3D numerical simulations of flow and transport of Jankovic et al. (2017) for different conductivity structures. The present study further explores the predictive capabilities of the Advection Dispersion Equation (ADE), with macrodispersivity αL given by the First Order Approximation (FOA), by checking in a quantitative manner its applicability. After a discussion on the suitable boundary conditions for ADE, we find that the ADE-FOA solution is a sufficiently accurate predictor for applications, the many other sources of uncertainty prevailing in practice notwithstanding. We checked by least squares and by comparison of travel time of quantiles of M that indeed the analytical Inverse Gaussian M with αL =σY2 I , is able to fit well the bulk of the simulated BTCs. It tends to underestimate the late arrival time of the thin and persistent tail. The tail is better reproduced by the semi-analytical MIMSCA model, which also allows for a physical explanation of the success of the Inverse Gaussian solution. Examination of the pertinent longitudinal mass distribution shows that it is different from the commonly used Gaussian one in the analysis of field experiments, and it captures the main features of the plume measurements of the MADE experiment. The results strengthen the confidence in the applicability of the ADE and the FOA to predicting longitudinal spreading in solute transport through heterogeneous aquifers of stationary random structure.

Generalized Vaidya solutions and Misner-Sharp mass for n -dimensional massive gravity

NASA Astrophysics Data System (ADS)

Hu, Ya-Peng; Wu, Xin-Meng; Zhang, Hongsheng

2017-04-01

Dynamical solutions are always of interest to people in gravity theories. We derive a series of generalized Vaidya solutions in the n -dimensional de Rham-Gabadadze-Tolley massive gravity with a singular reference metric. Similar to the case of the Einstein gravity, the generalized Vaidya solution can describe shining/absorbing stars. Moreover, we also find a more general Vaidya-like solution by introducing a more generic matter field than the pure radiation in the original Vaidya spacetime. As a result, the above generalized Vaidya solution is naturally included in this Vaidya-like solution as a special case. We investigate the thermodynamics for this Vaidya-like spacetime by using the unified first law and present the generalized Misner-Sharp mass. Our results show that the generalized Minser-Sharp mass does exist in this spacetime. In addition, the usual Clausius relation δ Q =T d S holds on the apparent horizon, which implicates that the massive gravity is in a thermodynamic equilibrium state. We find that the work density vanishes for the generalized Vaidya solution, while it appears in the more general Vaidya-like solution. Furthermore, the covariant generalized Minser-Sharp mass in the n -dimensional de Rham-Gabadadze-Tolley massive gravity is also derived by taking a general metric ansatz into account.

Quantum solution to a class of two-party private summation problems

NASA Astrophysics Data System (ADS)

Shi, Run-Hua; Zhang, Shun

2017-09-01

In this paper, we define a class of special two-party private summation (S2PPS) problems and present a common quantum solution to S2PPS problems. Compared to related classical solutions, our solution has advantages of higher security and lower communication complexity, and especially it can ensure the fairness of two parties without the help of a third party. Furthermore, we investigate the practical applications of our proposed S2PPS protocol in many privacy-preserving settings with big data sets, including private similarity decision, anonymous authentication, social networks, secure trade negotiation, secure data mining.

Solid-solution CrCoCuFeNi high-entropy alloy thin films synthesized by sputter deposition

DOE PAGES

An, Zhinan; Jia, Haoling; Wu, Yueying; ...

2015-05-04

The concept of high configurational entropy requires that the high-entropy alloys (HEAs) yield single-phase solid solutions. However, phase separations are quite common in bulk HEAs. A five-element alloy, CrCoCuFeNi, was deposited via radio frequency magnetron sputtering and confirmed to be a single-phase solid solution through the high-energy synchrotron X-ray diffraction, energy-dispersive spectroscopy, wavelength-dispersive spectroscopy, and transmission electron microscopy. The formation of the solid-solution phase is presumed to be due to the high cooling rate of the sputter-deposition process.

Symmetry restoration and quantumness reestablishment.

PubMed

Zeng, Guo-Mo; Wu, Lian-Ao; Xing, Hai-Jun

2014-09-18

A realistic quantum many-body system, characterized by a generic microscopic Hamiltonian, is accessible only through approximation methods. The mean field theories, as the simplest practices of approximation methods, commonly serve as a powerful tool, but unfortunately often violate the symmetry of the Hamiltonian. The conventional BCS theory, as an excellent mean field approach, violates the particle number conservation and completely erases quantumness characterized by concurrence and quantum discord between different modes. We restore the symmetry by using the projected BCS theory and the exact numerical solution and find that the lost quantumness is synchronously reestablished. We show that while entanglement remains unchanged with the particle numbers, quantum discord behaves as an extensive quantity with respect to the system size. Surprisingly, discord is hardly dependent on the interaction strengths. The new feature of discord offers promising applications in modern quantum technologies.

Standard Mutation Nomenclature in Molecular Diagnostics

PubMed Central

Ogino, Shuji; Gulley, Margaret L.; den Dunnen, Johan T.; Wilson, Robert B.

2007-01-01

To translate basic research findings into clinical practice, it is essential that information about mutations and variations in the human genome are communicated easily and unequivocally. Unfortunately, there has been much confusion regarding the description of genetic sequence variants. This is largely because research articles that first report novel sequence variants do not often use standard nomenclature, and the final genomic sequence is compiled over many separate entries. In this article, we discuss issues crucial to clear communication, using examples of genes that are commonly assayed in clinical laboratories. Although molecular diagnostics is a dynamic field, this should not inhibit the need for and movement toward consensus nomenclature for accurate reporting among laboratories. Our aim is to alert laboratory scientists and other health care professionals to the important issues and provide a foundation for further discussions that will ultimately lead to solutions. PMID:17251329

Influence of the extrinsic curvature on two-dimensional nematic films.

PubMed

Napoli, Gaetano; Vergori, Luigi

2018-05-01

Nematic films are thin fluid structures, ideally two dimensional, endowed with an in-plane degenerate nematic order. In this paper we examine a generalization of the classical Plateau problem to an axisymmetric nematic film bounded by two coaxial parallel rings. At equilibrium, the shape of the nematic film results from the competition between surface tension, which favors the minimization of the area, and the nematic elasticity, which instead promotes the alignment of the molecules along a common direction. We find two classes of equilibrium solutions in which the molecules are uniformly aligned along the meridians or parallels. Depending on two dimensionless parameters, one related to the geometry of the film and the other to the constitutive moduli, the Gaussian curvature of the equilibrium shape may be everywhere negative, vanishing, or positive. The stability of these equilibrium configurations is investigated.

Communication Matters: Exploring the Intersection of Family and Practitioner End of Life Communication

PubMed Central

Omilion-Hodges, Leah M.; Swords, Nathan M.

2017-01-01

After establishing a baseline understanding of some of the factors that influence and shape family end of life communication, empirical research centered on the communication tendencies of nationally-recognized palliative care clinicians is presented. Because death is no longer confined to the bedroom and individuals are increasingly turning to hospitals and health care institutes to assist with end of life, the role of palliative care practitioners is vital. To that end, common communication-rooted issues that may transpire among various medical personnel are explored. Focus on a shared underlying tension—care vs. cure—links the findings between family and palliative care clinician communication regarding end of life. Practical communication solutions and suggestions are offered to facilitate productive and mindful end of life communication between and among family members and health care practitioners. PMID:28335501

Communication Matters: Exploring the Intersection of Family and Practitioner End of Life Communication.

PubMed

Omilion-Hodges, Leah M; Swords, Nathan M

2017-03-19

After establishing a baseline understanding of some of the factors that influence and shape family end of life communication, empirical research centered on the communication tendencies of nationally-recognized palliative care clinicians is presented. Because death is no longer confined to the bedroom and individuals are increasingly turning to hospitals and health care institutes to assist with end of life, the role of palliative care practitioners is vital. To that end, common communication-rooted issues that may transpire among various medical personnel are explored. Focus on a shared underlying tension-care vs. cure-links the findings between family and palliative care clinician communication regarding end of life. Practical communication solutions and suggestions are offered to facilitate productive and mindful end of life communication between and among family members and health care practitioners.

Influence of the extrinsic curvature on two-dimensional nematic films

NASA Astrophysics Data System (ADS)

Napoli, Gaetano; Vergori, Luigi

2018-05-01

Nematic films are thin fluid structures, ideally two dimensional, endowed with an in-plane degenerate nematic order. In this paper we examine a generalization of the classical Plateau problem to an axisymmetric nematic film bounded by two coaxial parallel rings. At equilibrium, the shape of the nematic film results from the competition between surface tension, which favors the minimization of the area, and the nematic elasticity, which instead promotes the alignment of the molecules along a common direction. We find two classes of equilibrium solutions in which the molecules are uniformly aligned along the meridians or parallels. Depending on two dimensionless parameters, one related to the geometry of the film and the other to the constitutive moduli, the Gaussian curvature of the equilibrium shape may be everywhere negative, vanishing, or positive. The stability of these equilibrium configurations is investigated.

In-situ spectroscopic analysis of the traditional dyeing pigment Turkey red inside textile matrix

NASA Astrophysics Data System (ADS)

Meyer, M.; Huthwelker, T.; Borca, C. N.; Meßlinger, K.; Bieber, M.; Fink, R. H.; Späth, A.

2018-03-01

Turkey red is a traditional pigment for textile dyeing and its use has been proven for various cultures within the last three millennia. The pigment is a dye-mordant complex consisting of Al and an extract from R. tinctorum that contains mainly the anthraquinone derivative alizarin. The chemical structure of the complex has been analyzed by various spectroscopic and crystallographic techniques for extractions from textiles or directly in solution. We present an in-situ study of Turkey red by means of μ-XRF mapping and NEXAFS spectroscopy on textile fibres dyed according to a traditional process to gain insight into the coordination chemistry of the pigment in realistic matrix. We find an octahedral coordination of Al that corresponds well to the commonly accepted structure of the Al alizarin complex derived from ex-situ studies.

The modification of hybrid method of ant colony optimization, particle swarm optimization and 3-OPT algorithm in traveling salesman problem

NASA Astrophysics Data System (ADS)

Hertono, G. F.; Ubadah; Handari, B. D.

2018-03-01

The traveling salesman problem (TSP) is a famous problem in finding the shortest tour to visit every vertex exactly once, except the first vertex, given a set of vertices. This paper discusses three modification methods to solve TSP by combining Ant Colony Optimization (ACO), Particle Swarm Optimization (PSO) and 3-Opt Algorithm. The ACO is used to find the solution of TSP, in which the PSO is implemented to find the best value of parameters α and β that are used in ACO.In order to reduce the total of tour length from the feasible solution obtained by ACO, then the 3-Opt will be used. In the first modification, the 3-Opt is used to reduce the total tour length from the feasible solutions obtained at each iteration, meanwhile, as the second modification, 3-Opt is used to reduce the total tour length from the entire solution obtained at every iteration. In the third modification, 3-Opt is used to reduce the total tour length from different solutions obtained at each iteration. Results are tested using 6 benchmark problems taken from TSPLIB by calculating the relative error to the best known solution as well as the running time. Among those modifications, only the second and third modification give satisfactory results except the second one needs more execution time compare to the third modifications.

Uniform GTD solution for the diffraction by metallic tapes on panelled compact-range reflectors

NASA Technical Reports Server (NTRS)

Somers, G. A.; Pathak, P. H.

1992-01-01

Metallic tape is commonly used to cover the interpanel gaps which occur in paneled compact-range reflectors. It is therefore of interest to study the effect of the scattering by the tape on the field in the target zone of the range. An analytical solution is presented for the target zone fields scattered by 2D metallic tapes. It is formulated by the generalized scattering matrix technique in conjunction with the Wiener-Hopf procedure. An extension to treat 3D tapes can be accomplished using the 2D solution via the equivalent current concept. The analytical solution is compared with a reference moment method solution to confirm the accuracy of the former.

A study on Marangoni convection by the variational iteration method

NASA Astrophysics Data System (ADS)

Karaoǧlu, Onur; Oturanç, Galip

2012-09-01

In this paper, we will consider the use of the variational iteration method and Padé approximant for finding approximate solutions for a Marangoni convection induced flow over a free surface due to an imposed temperature gradient. The solutions are compared with the numerical (fourth-order Runge Kutta) solutions.

Laplace-Beltrami operator and exact solutions for branes

NASA Astrophysics Data System (ADS)

Zheltukhin, A. A.

2013-02-01

Proposed is a new approach to finding exact solutions of nonlinear p-brane equations in D-dimensional Minkowski space based on the use of various initial value constraints. It is shown that the constraints Δx→=0 and Δx→=-Λ(t,σr)x→ give two sets of exact solutions.

"helix Nebula - the Science Cloud", a European Science Driven Cross-Domain Initiative Implemented in via AN Active Ppp Set-Up

NASA Astrophysics Data System (ADS)

Lengert, W.; Mondon, E.; Bégin, M. E.; Ferrer, M.; Vallois, F.; DelaMar, J.

2015-12-01

Helix Nebula, a European science cross-domain initiative building on an active PPP, is aiming to implement the concept of an open science commons[1] while using a cloud hybrid model[2] as the proposed implementation solution. This approach allows leveraging and merging of complementary data intensive Earth Science disciplines (e.g. instrumentation[3] and modeling), without introducing significant changes in the contributors' operational set-up. Considering the seamless integration with life-science (e.g. EMBL), scientific exploitation of meteorological, climate, and Earth Observation data and models open an enormous potential for new big data science. The work of Helix Nebula has shown that is it feasible to interoperate publicly funded infrastructures, such as EGI [5] and GEANT [6], with commercial cloud services. Such hybrid systems are in the interest of the existing users of publicly funded infrastructures and funding agencies because they will provide "freedom and choice" over the type of computing resources to be consumed and the manner in which they can be obtained. But to offer such freedom and choice across a spectrum of suppliers, various issues such as intellectual property, legal responsibility, service quality agreements and related issues need to be addressed. Finding solutions to these issues is one of the goals of the Helix Nebula initiative. [1] http://www.egi.eu/news-and-media/publications/OpenScienceCommons_v3.pdf [2] http://www.helix-nebula.eu/events/towards-the-european-open-science-cloud [3] e.g. https://sentinel.esa.int/web/sentinel/sentinel-data-access [5] http://www.egi.eu/ [6] http://www.geant.net/

Is there a common water-activity limit for the three domains of life?

PubMed Central

Stevenson, Andrew; Cray, Jonathan A; Williams, Jim P; Santos, Ricardo; Sahay, Richa; Neuenkirchen, Nils; McClure, Colin D; Grant, Irene R; Houghton, Jonathan DR; Quinn, John P; Timson, David J; Patil, Satish V; Singhal, Rekha S; Antón, Josefa; Dijksterhuis, Jan; Hocking, Ailsa D; Lievens, Bart; Rangel, Drauzio E N; Voytek, Mary A; Gunde-Cimerman, Nina; Oren, Aharon; Timmis, Kenneth N; McGenity, Terry J; Hallsworth, John E

2015-01-01

Archaea and Bacteria constitute a majority of life systems on Earth but have long been considered inferior to Eukarya in terms of solute tolerance. Whereas the most halophilic prokaryotes are known for an ability to multiply at saturated NaCl (water activity (aw) 0.755) some xerophilic fungi can germinate, usually at high-sugar concentrations, at values as low as 0.650–0.605 aw. Here, we present evidence that halophilic prokayotes can grow down to water activities of <0.755 for Halanaerobium lacusrosei (0.748), Halobacterium strain 004.1 (0.728), Halobacterium sp. NRC-1 and Halococcus morrhuae (0.717), Haloquadratum walsbyi (0.709), Halococcus salifodinae (0.693), Halobacterium noricense (0.687), Natrinema pallidum (0.681) and haloarchaeal strains GN-2 and GN-5 (0.635 aw). Furthermore, extrapolation of growth curves (prone to giving conservative estimates) indicated theoretical minima down to 0.611 aw for extreme, obligately halophilic Archaea and Bacteria. These were compared with minima for the most solute-tolerant Bacteria in high-sugar (or other non-saline) media (Mycobacterium spp., Tetragenococcus halophilus, Saccharibacter floricola, Staphylococcus aureus and so on) and eukaryotic microbes in saline (Wallemia spp., Basipetospora halophila, Dunaliella spp. and so on) and high-sugar substrates (for example, Xeromyces bisporus, Zygosaccharomyces rouxii, Aspergillus and Eurotium spp.). We also manipulated the balance of chaotropic and kosmotropic stressors for the extreme, xerophilic fungi Aspergillus penicilloides and X. bisporus and, via this approach, their established water-activity limits for mycelial growth (∼0.65) were reduced to 0.640. Furthermore, extrapolations indicated theoretical limits of 0.632 and 0.636 aw for A. penicilloides and X. bisporus, respectively. Collectively, these findings suggest that there is a common water-activity limit that is determined by physicochemical constraints for the three domains of life. PMID:25500507

Using MathCAD to Teach One-Dimensional Graphs

ERIC Educational Resources Information Center

Yushau, B.

2004-01-01

Topics such as linear and nonlinear equations and inequalities, compound inequalities, linear and nonlinear absolute value equations and inequalities, rational equations and inequality are commonly found in college algebra and precalculus textbooks. What is common about these topics is the fact that their solutions and graphs lie in the real line…

New Analytical Solution of the Equilibrium Ampere's Law Using the Walker's Method: a Didactic Example

NASA Astrophysics Data System (ADS)

Sousa, A. N. Laurindo; Ojeda-González, A.; Prestes, A.; Klausner, V.; Caritá, L. A.

2018-02-01

This work aims to demonstrate the analytical solution of the Grad-Shafranov (GS) equation or generalized Ampere's law, which is important in the studies of self-consistent 2.5-D solution for current sheet structures. A detailed mathematical development is presented to obtain the generating function as shown by Walker (RSPSA 91, 410, 1915). Therefore, we study the general solution of the GS equation in terms of the Walker's generating function in details without omitting any step. The Walker's generating function g( ζ) is written in a new way as the tangent of an unspecified function K( ζ). In this trend, the general solution of the GS equation is expressed as exp(- 2Ψ) = 4| K '( ζ)|2/cos2[ K( ζ) - K( ζ ∗)]. In order to investigate whether our proposal would simplify the mathematical effort to find new generating functions, we use Harris's solution as a test, in this case K( ζ) = arctan(exp( i ζ)). In summary, one of the article purposes is to present a review of the Harris's solution. In an attempt to find a simplified solution, we propose a new way to write the GS solution using g( ζ) = tan( K( ζ)). We also present a new analytical solution to the equilibrium Ampere's law using g( ζ) = cosh( b ζ), which includes a generalization of the Harris model and presents isolated magnetic islands.

Exact solutions of massive gravity in three dimensions

NASA Astrophysics Data System (ADS)

Chakhad, Mohamed

In recent years, there has been an upsurge in interest in three-dimensional theories of gravity. In particular, two theories of massive gravity in three dimensions hold strong promise in the search for fully consistent theories of quantum gravity, an understanding of which will shed light on the problems of quantum gravity in four dimensions. One of these theories is the "old" third-order theory of topologically massive gravity (TMG) and the other one is a "new" fourth-order theory of massive gravity (NMG). Despite this increase in research activity, the problem of finding and classifying solutions of TMG and NMG remains a wide open area of research. In this thesis, we provide explicit new solutions of massive gravity in three dimensions and suggest future directions of research. These solutions belong to the Kundt class of spacetimes. A systematic analysis of the Kundt solutions with constant scalar polynomial curvature invariants provides a glimpse of the structure of the spaces of solutions of the two theories of massive gravity. We also find explicit solutions of topologically massive gravity whose scalar polynomial curvature invariants are not all constant, and these are the first such solutions. A number of properties of Kundt solutions of TMG and NMG, such as an identification of solutions which lie at the intersection of the full nonlinear and linearized theories, are also derived.

New Analytical Solution of the Equilibrium Ampere's Law Using the Walker's Method: a Didactic Example

NASA Astrophysics Data System (ADS)

Sousa, A. N. Laurindo; Ojeda-González, A.; Prestes, A.; Klausner, V.; Caritá, L. A.

2017-12-01

This work aims to demonstrate the analytical solution of the Grad-Shafranov (GS) equation or generalized Ampere's law, which is important in the studies of self-consistent 2.5-D solution for current sheet structures. A detailed mathematical development is presented to obtain the generating function as shown by Walker (RSPSA 91, 410, 1915). Therefore, we study the general solution of the GS equation in terms of the Walker's generating function in details without omitting any step. The Walker's generating function g(ζ) is written in a new way as the tangent of an unspecified function K(ζ). In this trend, the general solution of the GS equation is expressed as exp(- 2Ψ) = 4|K '(ζ)|2/cos2[K(ζ) - K(ζ ∗)]. In order to investigate whether our proposal would simplify the mathematical effort to find new generating functions, we use Harris's solution as a test, in this case K(ζ) = arctan(exp(i ζ)). In summary, one of the article purposes is to present a review of the Harris's solution. In an attempt to find a simplified solution, we propose a new way to write the GS solution using g(ζ) = tan(K(ζ)). We also present a new analytical solution to the equilibrium Ampere's law using g(ζ) = cosh(b ζ), which includes a generalization of the Harris model and presents isolated magnetic islands.

Supersymmetric Janus solutions of dyonic ISO(7)-gauged N = 8 supergravity

NASA Astrophysics Data System (ADS)

Suh, Minwoo

2018-04-01

We study supersymmetric Janus solutions of dyonic ISO(7)-gauged N = 8 supergravity. We mostly find Janus solutions flowing to 3d N = 8 SYM phase which is the worldvolume theory on D2-branes and non-conformal. There are also solutions flowing from the critical points which are dual to 3d SCFTs from deformations of the D2-brane theory.

α-keratin/Alginate Biosorbent for Removal of Methylene Blue on Aqueous Solution in a Batch System

NASA Astrophysics Data System (ADS)

Fadillah, G.; Putri, E. N. K.; Febrianastuti, S.; Munawaroh, H.; Purnawan, C.; Wahyuningsih, S.

2018-03-01

Methylene Blue (MB) is a cationic dyes which is commonly used in textile industries for coloring agent. The precence of MB in water caused some negative effect on the environment and human health. Many common technologies such as membrane filtration, electrophoresis and adsorption have been widely empolyed for removal of MB in water, but the adsorption technique still has advantages than the others. In this study, removal of MB used a biosorbent α-keratin/alginate (KA). The biosorbent KA was prepared by using the encapsulation technique in CaCl2 2 % (w/v) solution. The biosorbent was characterized by Fourier Transform Infrared (FTIR) and Scanning Electron Microscope (SEM). The effect of composition of α-keratin and alginate, the pH of solution and contact time on the adsorption were investigated. The optimum adsorption of MB in aqueous solution was found at the composition of α-keratin and alginate of 1:2 (w/w), the pH at 5.0 and contact time at 4 hours. The adsorption of MB on KA biosorbent was comparatively higher than α-keratin and alginate only. Adsorption of MB dyes in aqueous solution followed the Langmuir adsorption isotherm, and the dynamic adsorption model could be described through a pseudo-second order kinetics.

Product Mix Selection Using AN Evolutionary Technique

NASA Astrophysics Data System (ADS)

Tsoulos, Ioannis G.; Vasant, Pandian

2009-08-01

This paper proposes an evolutionary technique for the solution of a real—life industrial problem and particular for the product mix selection problem. The evolutionary technique is a combination of a genetic algorithm that preserves the feasibility of the trial solutions with penalties and some local optimization method. The goal of this paper has been achieved in finding the best near optimal solution for the profit fitness function respect to vagueness factor and level of satisfaction. The findings of the profit values will be very useful for the decision makers in the industrial engineering sector for the implementation purpose. It's possible to improve the solutions obtained in this study by employing other meta-heuristic methods such as simulated annealing, tabu Search, ant colony optimization, particle swarm optimization and artificial immune systems.

Stokes phenomena in discrete Painlevé II.

PubMed

Joshi, N; Lustri, C J; Luu, S

2017-02-01

We consider the asymptotic behaviour of the second discrete Painlevé equation in the limit as the independent variable becomes large. Using asymptotic power series, we find solutions that are asymptotically pole-free within some region of the complex plane. These asymptotic solutions exhibit Stokes phenomena, which is typically invisible to classical power series methods. We subsequently apply exponential asymptotic techniques to investigate such phenomena, and obtain mathematical descriptions of the rapid switching behaviour associated with Stokes curves. Through this analysis, we determine the regions of the complex plane in which the asymptotic behaviour is described by a power series expression, and find that the behaviour of these asymptotic solutions shares a number of features with the tronquée and tri-tronquée solutions of the second continuous Painlevé equation.

Phase Separation in Solutions of Monoclonal Antibodies

NASA Astrophysics Data System (ADS)

Benedek, George; Wang, Ying; Lomakin, Aleksey; Latypov, Ramil

2012-02-01

We report the observation of liquid-liquid phase separation (LLPS) in a solution of humanized monoclonal antibodies, IgG2, and the effects of human serum albumin, a major blood protein, on this phase separation. We find a significant reduction of phase separation temperature in the presence of albumin, and a preferential partitioning of the albumin into the antibody-rich phase. We provide a general thermodynamic analysis of the antibody-albumin mixture phase diagram and relate its features to the magnitude of the effective inter-protein interactions. Our analysis suggests that additives (HSA in this report), which have moderate attraction with antibody molecules, may be used to forestall undesirable protein condensation in antibody solutions. Our findings are relevant to understanding the stability of pharmaceutical solutions of antibodies and the mechanisms of cryoglobulinemia.

Stokes phenomena in discrete Painlevé II

PubMed Central

Joshi, N.

2017-01-01

We consider the asymptotic behaviour of the second discrete Painlevé equation in the limit as the independent variable becomes large. Using asymptotic power series, we find solutions that are asymptotically pole-free within some region of the complex plane. These asymptotic solutions exhibit Stokes phenomena, which is typically invisible to classical power series methods. We subsequently apply exponential asymptotic techniques to investigate such phenomena, and obtain mathematical descriptions of the rapid switching behaviour associated with Stokes curves. Through this analysis, we determine the regions of the complex plane in which the asymptotic behaviour is described by a power series expression, and find that the behaviour of these asymptotic solutions shares a number of features with the tronquée and tri-tronquée solutions of the second continuous Painlevé equation. PMID:28293132

How is the Department of Veterans Affairs addressing the new Accreditation Council for Graduate Medical Education intern work hour limitations? Solutions from the Association of Veterans Affairs Surgeons.

PubMed

Hayman, Amanda V; Tarpley, John L; Berger, David H; Wilson, Mark A; Livingston, Edward H; Kibbe, Melina R

2012-11-01

The Accreditation Council for Graduate Medical Education implemented new intern work-hour regulations in July 2011 that have unique implications for surgical training at Veterans Affairs (VA) medical centers. Implementation of these new regulations required profound restructuring of trainee night coverage systems at many VA medical centers. This article offers approaches and potential solutions to the Accreditation Council for Graduate Medical Education regulations used by different surgery programs throughout the country that are applicable to the VA training environment. The information contained in this article was derived from the opinion of a panel of academic surgical leaders in the VA system and responses to a survey that was sent to national VA surgical leaders. The most common solution chosen by the VA centers was hiring physician extenders (37%). The most common type of extender was a nonphysician extender, that is, nurse practitioner or physician assistant (70%), followed by a surgical hospitalist (33%), and surgical resident moonlighter (24%). Other common solutions included the following: night float for residents (22%) or interns (19%), establishing early versus late shifts (19%), or establishing cross-institutional or disciplinary coverage (19%). The public expects the medical community to produce safe, experienced surgeons, while demanding they are well rested and directly supervised at all times. The ability to meet these expectations can be challenging. Published by Elsevier Inc.

Annual estimates of water and solute export from 42 tributaries to the Yukon River

USGS Publications Warehouse

Frederick Zanden,; Suzanne P. Anderson,; Striegl, Robert G.

2012-01-01

Annual export of 11 major and trace solutes for the Yukon River is found to be accurately determined based on summing 42 tributary contributions. These findings provide the first published estimates of tributary specific distribution of solutes within the Yukon River basin. First, we show that annual discharge of the Yukon River can be computed by summing calculated annual discharges from 42 tributaries. Annual discharge for the tributaries is calculated from the basin area and average annual precipitation over that area using a previously published regional regression equation. Based on tributary inputs, we estimate an average annual discharge for the Yukon River of 210 km3 year–1. This value is within 1% of the average measured annual discharge at the U.S. Geological Survey gaging station near the river terminus at Pilot Station, AK, for water years 2001 through 2005. Next, annual loads for 11 solutes are determined by combining annual discharge with point measurements of solute concentrations in tributary river water. Based on the sum of solutes in tributary water, we find that the Yukon River discharges approximately 33 million metric tons of dissolved solids each year at Pilot Station. Discharged solutes are dominated by cations calcium and magnesium (5.65 × 109 and 1.42 × 109 g year–1) and anions bicarbonate and sulphate (17.3 × 109 and 5.40 × 109 g year–1). These loads compare well with loads calculated independently at the three continuous gaging stations along the Yukon River. These findings show how annual solute yields vary throughout a major subarctic river basin and that accurate estimates of total river export can be determined from calculated tributary contributions.

Small-on-large geometric anelasticity

PubMed Central

2016-01-01

In this paper, we are concerned with finding exact solutions for the stress fields of nonlinear solids with non-symmetric distributions of defects (or more generally finite eigenstrains) that are small perturbations of symmetric distributions of defects with known exact solutions. In the language of geometric mechanics, this corresponds to finding a deformation that is a result of a perturbation of the metric of the Riemannian material manifold. We present a general framework that can be used for a systematic analysis of this class of anelasticity problems. This geometric formulation can be thought of as a material analogue of the classical small-on-large theory in nonlinear elasticity. We use the present small-on-large anelasticity theory to find exact solutions for the stress fields of some non-symmetric distributions of screw dislocations in incompressible isotropic solids. PMID:27956887

Parametrically driven scalar field in an expanding background

NASA Astrophysics Data System (ADS)

Yanez-Pagans, Sergio; Urzagasti, Deterlino; Oporto, Zui

2017-10-01

We study the existence and dynamic behavior of localized and extended structures in a massive scalar inflaton field ϕ in 1 +1 dimensions in the framework of an expanding universe with constant Hubble parameter. We introduce a parametric forcing, produced by another quantum scalar field ψ , over the effective mass squared around the minimum of the inflaton potential. For this purpose, we study the system in the context of the cubic quintic complex Ginzburg-Landau equation and find the associated amplitude equation to the cosmological scalar field equation, which near the parametric resonance allows us to find the field amplitude. We find homogeneous null solutions, flat-top expanding solitons, and dark soliton patterns. No persistent non-null solutions are found in the absence of parametric forcing, and divergent solutions are obtained when the forcing amplitude is greater than 4 /3 .

Stochasticity in numerical solutions of the nonlinear Schroedinger equation

NASA Technical Reports Server (NTRS)

Shen, Mei-Mei; Nicholson, D. R.

1987-01-01

The cubically nonlinear Schroedinger equation is an important model of nonlinear phenomena in fluids and plasmas. Numerical solutions in a spatially periodic system commonly involve truncation to a finite number of Fourier modes. These solutions are found to be stochastic in the sense that the largest Liapunov exponent is positive. As the number of modes is increased, the size of this exponent appears to converge to zero, in agreement with the recent demonstration of the integrability of the spatially periodic case.

Complications in complexation kinetics for lanthanides with DTPA using dye probe molecules in aqueous solution

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

Larsson, K.; Cullen, T. D.; Mezyk, S. P.

The complexation kinetics for the polyaminopolycarboxylic ligand DTPA to lanthanides in acidic aqueous solution were investigated using the dye ligand displacement technique and stopped-flow spectroscopy. Significant rate differences were obtained for different dye probes used, indicating that the kinetics of the dissociation of the dye molecule significantly impacts the overall measured kinetics when using this common methodology. The conditions of the solution also influenced the dye-lanthanide-DTPA interactions, which reconciled previously disparate data in the literature.

Comparison of solute-binding properties of plastic materials used as pharmaceutical product containers.

PubMed

Jenke, Dennis; Couch, Tom; Gillum, Amy

2010-01-01

Material/water equilibrium binding constants (E(b)) were determined for 11 organic solutes and 2 plastic materials commonly used in pharmaceutical product containers (plasticized polyvinyl chloride and polyolefin). In general, solute binding by the plasticized polyvinyl chloride material was greater, by nearly an order of magnitude, than the binding by the polyolefin (on an equal weight basis). The utilization of the binding constants to facilitate container compatibility assessments (e.g., drug loss by container binding) for drug-containing products is discussed.