Neoclassical Theory and Its Applications

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

Shaing, Ker-Chung

2015-11-20

The grant entitled Neoclassical Theory and Its Applications started on January 15 2001 and ended on April 14 2015. The main goal of the project is to develop neoclassical theory to understand tokamak physics, and employ it to model current experimental observations and future thermonuclear fusion reactors. The PI had published more than 50 papers in refereed journals during the funding period.

Experimental and theoretical study of the influence of water on hydrolyzed product formation during the feruloylation of vegetable oil.

PubMed

Compton, David L; Evans, Kervin O; Appell, Michael

2017-07-01

Feruloylated vegetable oil is a valuable green bioproduct that has several cosmeceutical applications associated with its inherent anti-oxidant and ultraviolet-absorption properties. Hydrolyzed vegetable oil by-products can influence product quality and consistency. The formation of by-products by residual water in the enzymatic synthesis of feruloylated vegetable oil was investigated using chemical theory and experimental studies by monitoring the reaction over a 22-day period. The hydrolysis of vegetable oil is thermodynamically favored over the hydrolysis of the ethyl ferulate starting material. These results suggest that hydrolyzed vegetable oil products will be experimentally observed in greater concentrations compared to hydrolyzed ethyl ferulate products. Quantum chemical studies identified several reaction mechanisms that explain the formation of side products by water, suggesting that residual water influences product quality. Efforts to reduce residual water can improve product consistency and reduce purification costs. Published 2016. This article is a U.S. Government work and is in the public domain in the USA. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

Publishing Single-Case Research Design Studies That Do Not Demonstrate Experimental Control

ERIC Educational Resources Information Center

Tincani, Matt; Travers, Jason

2018-01-01

Demonstration of experimental control is considered a hallmark of high-quality single-case research design (SCRD). Studies that fail to demonstrate experimental control may not be published because researchers are unwilling to submit these papers for publication and journals are unlikely to publish negative results (i.e., the file drawer effect).…

Seeing mental states: An experimental strategy for measuring the observability of other minds

NASA Astrophysics Data System (ADS)

Becchio, Cristina; Koul, Atesh; Ansuini, Caterina; Bertone, Cesare; Cavallo, Andrea

2018-03-01

Is it possible to perceive others' mental states? Are mental states visible in others' behavior? In contrast to the traditional view that mental states are hidden and not directly accessible to perception, in recent years a phenomenologically-motivated account of social cognition has emerged: direct social perception. However, despite numerous published articles that both defend and critique direct perception, researchers have made little progress in articulating the conditions under which direct perception of others' mental states is possible. This paper proposes an empirically anchored approach to the observability of others' mentality - not just in the weak sense of discussing relevant empirical evidence for and against the phenomenon of interest, but also, and more specifically, in the stronger sense of identifying an experimental strategy for measuring the observability of mental states and articulating the conditions under which mental states are observable. We conclude this article by reframing the problem of direct perception in terms of establishing a definable and measurable relationship between movement features and perceived mental states.

An experimental approach in revisiting the magnetic orientation of cattle

PubMed Central

Weijers, Debby; Hemerik, Lia; Heitkönig, Ignas M. A.

2018-01-01

In response to the increasing number of observational studies on an apparent south-north orientation in non-homing, non-migrating terrestrial mammals, we experimentally tested the alignment hypothesis using strong neodymium magnets on the resting orientation of individual cattle in Portugal. Contrary to the hypothesis, the 34 cows in the experiment showed no directional preference, neither with, nor without a strong neodymium magnet fixed to their collar. The concurrently performed 2,428 daytime observations—excluding the hottest part of the day—of 659 resting individual cattle did not show a south-north alignment when at rest either. The preferred compass orientation of these cows was on average 130 degrees from the magnetic north (i.e., south east). Cow compass orientation correlated significantly with sun direction, but not with wind direction. In as far as we can determine, this is the first experimental test on magnetic orientation in larger, non-homing, non-migrating mammals. These experimental and observational findings do not support previously published suggestions on the magnetic south-north alignment in these mammals. PMID:29641517

Cluster kinetics model of particle separation in vibrated granular media.

PubMed

McCoy, Benjamin J; Madras, Giridhar

2006-01-01

We model the Brazil-nut effect (BNE) by hypothesizing that granules form clusters that fragment and aggregate. This provides a heterogeneous medium in which the immersed intruder particle rises (BNE) or sinks (reverse BNE) according to relative convection currents and buoyant and drag forces. A simple relationship proposed for viscous drag in terms of the vibrational intensity and the particle to grain density ratio allows simulation of published experimental data for rise and sink times as functions of particle radius, initial depth of the particle, and particle-grain density ratio. The proposed model correctly describes the experimentally observed maximum in risetime.

p-Curve and p-Hacking in Observational Research

PubMed Central

Bruns, Stephan B.; Ioannidis, John P. A.

2016-01-01

The p-curve, the distribution of statistically significant p-values of published studies, has been used to make inferences on the proportion of true effects and on the presence of p-hacking in the published literature. We analyze the p-curve for observational research in the presence of p-hacking. We show by means of simulations that even with minimal omitted-variable bias (e.g., unaccounted confounding) p-curves based on true effects and p-curves based on null-effects with p-hacking cannot be reliably distinguished. We also demonstrate this problem using as practical example the evaluation of the effect of malaria prevalence on economic growth between 1960 and 1996. These findings call recent studies into question that use the p-curve to infer that most published research findings are based on true effects in the medical literature and in a wide range of disciplines. p-values in observational research may need to be empirically calibrated to be interpretable with respect to the commonly used significance threshold of 0.05. Violations of randomization in experimental studies may also result in situations where the use of p-curves is similarly unreliable. PMID:26886098

Real Time In Situ Observations of Equiaxed Dendrite Coherency in Al-Cu Alloys Using High-Brilliance, 3rd Generation Synchrotron Sources

NASA Technical Reports Server (NTRS)

Murphy, Andrew G.; Browne, David J.; Mirihanage, Wajira U.; Mathiesen, Ragnvald H.

2012-01-01

In the last decade synchrotron X-ray sources have fast become the tool of choice for performing in-situ high resolution imaging during alloy solidification. This paper presents the results of an experimental campaign carried out at the European Synchrotron Radiation Facility, using a Bridgman furnace, to monitor phenomena during solidification of Al-Cu alloys - specifically the onset of equiaxed dendrite coherency. Conventional experimental methods for determining coherency involve measuring the change in viscosity or measuring the change in thermal conductivity across the solidifying melt Conflicts arise when comparing the results of these experimental techniques to find a relationship between cooling rate and coherency fraction. It has been shown that the ratio of average velocity to the average grain diameter has an inversely proportional relationship to coherency fraction. In-situ observation therefore makes it possible to measure these values directly from acquired images sequences and make comparisons with published results.

78 FR 41129 - Market Test of Experimental Product - International Merchandise Return Service-Non-Published Rates

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-09

...--Non-Published Rates AGENCY: U.S. Postal Service\\TM\\. ACTION: Notice. SUMMARY: The Postal Service hereby gives notice of a market test for International Merchandise Return Service--Non-Published Rates in... Return Service (IMRS) Non-published Rate (NPR) experimental product on August 15, 2013. The Postal...

Geometric Limitations Of Ultrasonic Measurements

NASA Astrophysics Data System (ADS)

von Nicolai, C.; Schilling, F.

2006-12-01

Laboratory experiments are a key for interpreting seismic field observations. Due to their potential in many experimental set-ups, the determination of elastic properties of minerals and rocks by ultrasonic measurements is common in Geosciences. The quality and thus use of ultrasonic data, however, strongly depends on the sample geometry and wavelength of the sound wave. Two factors, the diameter-to-wavelength- ratio and the diameter-to-length-ratio, are believed to be the essential parameters to affect ultrasonic signal quality. In this study, we determined under well defined conditions the restricting dimensional parameters to test the validity of published assumptions. By the use of commercial ultrasonic transducers a number of experiments were conducted on aluminium, alumina, and acrylic glass rods of varying diameter (30-10 mm) and constant length. At each diameter compressional wave travel times were measured by pulse- transmission method. From the observed travel times ultrasonic wave velocities were calculated. One additional experiment was performed with a series of square-shaped aluminium blocks in order to investigate the effect of the geometry of the samples cross-sectional area. The experimental results show that the simple diameter-to-wavelength ratios are not valid even under idealized experimental conditions and more complex relation has to be talen into account. As diameter decreases the P-waves direct phase is increasingly interfered and weakened by sidewall reflections. At very small diameters compressional waves are replaced by bar waves and P-wave signals become non resolvable. Considering the suppression of both effects, a critical D/ë-ratio was determined and compared to experimental set-ups from various publications. These tests indicate that some published and cited data derived from small diameter set-ups are out off the range of physical possibility.

From Einstein-Podolsky-Rosen paradox to quantum nonlocality: experimental investigation of quantum correlations

NASA Astrophysics Data System (ADS)

Xu, Jin-Shi; Li, Chuan-Feng; Guo, Guang-Can

2016-11-01

In 1935, Einstein, Podolsky and Rosen published their influential paper proposing a now famous paradox (the EPR paradox) that threw doubt on the completeness of quantum mechanics. Two fundamental concepts: entanglement and steering, were given in the response to the EPR paper by Schrodinger, which both reflect the nonlocal nature of quantum mechanics. In 1964, John Bell obtained an experimentally testable inequality, in which its violation contradicts the prediction of local hidden variable models and agrees with that of quantum mechanics. Since then, great efforts have been made to experimentally investigate the nonlocal feature of quantum mechanics and many distinguished quantum properties were observed. In this work, along with the discussion of the development of quantum nonlocality, we would focus on our recent experimental efforts in investigating quantum correlations and their applications with optical systems, including the study of entanglement-assisted entropic uncertainty principle, Einstein-Podolsky-Rosen steering and the dynamics of quantum correlations.

Annual tendency of research papers used ICR mice as experimental animals in biomedical research fields.

PubMed

Kim, Ji Eun; Nam, Jung Hoon; Cho, Joon Young; Kim, Kil Soo; Hwang, Dae Youn

2017-06-01

Institute of Cancer Research (ICR) mice have been widely used in various research fields including toxicology, oncology, pharmacology, and pharmaceutical product safety testing for decades. However, annual tendency of research papers involving ICR mice in various biomedical fields has not been previously analyzed. In this study, we examined the numbers of papers that used ICR mice as experimental animals in the social science, natural science, engineering, medicine-pharmacy, marine agriculture-fishery, and art-kinesiology fields by analyzing big data. Numbers of ICR mouse-used papers gradually increased from 1961 to 2014, but small decreases were observed in 2015 and 2016. The largest number of ICR-used papers were published in the medicine-pharmacy field, followed by natural science and art-kinesiology fields. There were no ICR mouse-used papers in other fields. Furthermore, ICR mice have been widely employed in cell biology studies within the natural science field as well as in biochemistry and pathology in the medicine-pharmacy field. Few ICR mouse-used papers were published in exercise biochemistry and exercise nutrition in the art-kinesiology field. Regardless in most fields, the total numbers of published papers involving ICR mice were higher in 2014 than in other years, although the numbers in some fields including dentistry, veterinary science, and dermatology were high in 2016. Taken together, the present study shows that various ICR stocks, including Korl:ICR mice, are widely employed as experimental animals in various biomedical research fields.

Annual tendency of research papers used ICR mice as experimental animals in biomedical research fields

PubMed Central

Kim, Ji Eun; Nam, Jung Hoon; Cho, Joon Young; Kim, Kil Soo

2017-01-01

Institute of Cancer Research (ICR) mice have been widely used in various research fields including toxicology, oncology, pharmacology, and pharmaceutical product safety testing for decades. However, annual tendency of research papers involving ICR mice in various biomedical fields has not been previously analyzed. In this study, we examined the numbers of papers that used ICR mice as experimental animals in the social science, natural science, engineering, medicine-pharmacy, marine agriculture-fishery, and art-kinesiology fields by analyzing big data. Numbers of ICR mouse-used papers gradually increased from 1961 to 2014, but small decreases were observed in 2015 and 2016. The largest number of ICR-used papers were published in the medicine-pharmacy field, followed by natural science and art-kinesiology fields. There were no ICR mouse-used papers in other fields. Furthermore, ICR mice have been widely employed in cell biology studies within the natural science field as well as in biochemistry and pathology in the medicine-pharmacy field. Few ICR mouse-used papers were published in exercise biochemistry and exercise nutrition in the art-kinesiology field. Regardless in most fields, the total numbers of published papers involving ICR mice were higher in 2014 than in other years, although the numbers in some fields including dentistry, veterinary science, and dermatology were high in 2016. Taken together, the present study shows that various ICR stocks, including Korl:ICR mice, are widely employed as experimental animals in various biomedical research fields. PMID:28747984

Developments in the field of allergy in 2009 through the eyes of Clinical and Experimental Allergy.

PubMed

Chu, H W; Lloyd, C M; Karmaus, W; Maestrelli, P; Mason, P; Salcedo, G; Thaikoottathil, J; Wardlaw, A J

2010-11-01

In 2009 the journal published in the region of 200 papers including reviews, editorials, opinion pieces and original papers that ran the full gamut of allergic disease. It is instructive to take stock of this output to determine patterns of interest and where the cutting edge lies. We have surveyed the field of allergic disease as seen through the pages of Clinical and Experimental Allergy (CEA) highlighting trends, emphasizing notable observations and placing discoveries in the context of other key papers published during the year. The review is divided into similar sections as the journal. In the field of Asthma and Rhinitis CEA has contributed significantly to the debate about asthma phenotypes and expressed opinions about the cause of intrinsic asthma. It has also added its halfpennyworth to the hunt for meaningful biomarkers. In Mechanisms the considerable interest in T cell subsets including Th17 and T regulatory cells continues apace and the discipline of Epidemiology continues to invoke a steady stream of papers on risk factors for asthma with investigators still trying to explain the post-second world war epidemic of allergic disease. Experimental Models continue to make important contributions to our understanding of pathogenesis of allergic disease and in the Clinical Allergy section various angles on immunotherapy are explored. New allergens continue to be described in the allergens section to make those allergen chips even more complicated. A rich and vibrant year helpfully summarized by some of our associate editors. © 2010 Blackwell Publishing Ltd.

Energetic particle-driven compressional Alfvén eigenmodes and prospects for ion cyclotron emission studies in fusion plasmas

NASA Astrophysics Data System (ADS)

Gorelenkov, N. N.

2016-10-01

As a fundamental plasma oscillation the compressional Alfvén waves (CAWs) are interesting for plasma scientists both academically and in applications for fusion plasmas. They are believed to be responsible for the ion cyclotron emission (ICE) observed in many tokamaks. The theory of CAW and ICE was significantly advanced at the end of 20th century in particular motivated by first DT experiments on TFTR and subsequent JET DT experimental studies. More recently, ICE theory was advanced by ST (or spherical torus) experiments with the detailed theoretical and experimental studies of the properties of each instability signal. There the instability responsible for ICE signals previously indistinguishable in high aspect ratio tokamaks became the subjects of experimental studies. We discuss further the prospects of ICE theory and its applications for future burning plasma experiments such as the ITER tokamak-reactor prototype being build in France where neutrons and gamma rays escaping the plasma create extremely challenging conditions for fusion alpha particle diagnostics. This manuscript has been authored by Princeton University under Contract Number DE-AC02-09CH11466 with the US Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes.

Effects of developmental variability on the dynamics and self-organization of cell populations

NASA Astrophysics Data System (ADS)

Prabhakara, Kaumudi H.; Gholami, Azam; Zykov, Vladimir S.; Bodenschatz, Eberhard

2017-11-01

We report experimental and theoretical results for spatiotemporal pattern formation in cell populations, where the parameters vary in space and time due to mechanisms intrinsic to the system, namely Dictyostelium discoideum (D.d.) in the starvation phase. We find that different patterns are formed when the populations are initialized at different developmental stages, or when populations at different initial developmental stages are mixed. The experimentally observed patterns can be understood with a modified Kessler-Levine model that takes into account the initial spatial heterogeneity of the cell populations and a developmental path introduced by us, i.e. the time dependence of the various biochemical parameters. The dynamics of the parameters agree with known biochemical studies. Most importantly, the modified model reproduces not only our results, but also the observations of an independent experiment published earlier. This shows that pattern formation can be used to understand and quantify the temporal evolution of the system parameters.

Estimating the Diffusion Coefficients of Sugars Using Diffusion Experiments in Agar-Gel and Computer Simulations.

PubMed

Miyamoto, Shuichi; Atsuyama, Kenji; Ekino, Keisuke; Shin, Takashi

2018-01-01

The isolation of useful microbes is one of the traditional approaches for the lead generation in drug discovery. As an effective technique for microbe isolation, we recently developed a multidimensional diffusion-based gradient culture system of microbes. In order to enhance the utility of the system, it is favorable to have diffusion coefficients of nutrients such as sugars in the culture medium beforehand. We have, therefore, built a simple and convenient experimental system that uses agar-gel to observe diffusion. Next, we performed computer simulations-based on random-walk concepts-of the experimental diffusion system and derived correlation formulas that relate observable diffusion data to diffusion coefficients. Finally, we applied these correlation formulas to our experimentally-determined diffusion data to estimate the diffusion coefficients of sugars. Our values for these coefficients agree reasonably well with values published in the literature. The effectiveness of our simple technique, which has elucidated the diffusion coefficients of some molecules which are rarely reported (e.g., galactose, trehalose, and glycerol) is demonstrated by the strong correspondence between the literature values and those obtained in our experiments.

SS-mPMG and SS-GA: tools for finding pathways and dynamic simulation of metabolic networks.

PubMed

Katsuragi, Tetsuo; Ono, Naoaki; Yasumoto, Keiichi; Altaf-Ul-Amin, Md; Hirai, Masami Y; Sriyudthsak, Kansuporn; Sawada, Yuji; Yamashita, Yui; Chiba, Yukako; Onouchi, Hitoshi; Fujiwara, Toru; Naito, Satoshi; Shiraishi, Fumihide; Kanaya, Shigehiko

2013-05-01

Metabolomics analysis tools can provide quantitative information on the concentration of metabolites in an organism. In this paper, we propose the minimum pathway model generator tool for simulating the dynamics of metabolite concentrations (SS-mPMG) and a tool for parameter estimation by genetic algorithm (SS-GA). SS-mPMG can extract a subsystem of the metabolic network from the genome-scale pathway maps to reduce the complexity of the simulation model and automatically construct a dynamic simulator to evaluate the experimentally observed behavior of metabolites. Using this tool, we show that stochastic simulation can reproduce experimentally observed dynamics of amino acid biosynthesis in Arabidopsis thaliana. In this simulation, SS-mPMG extracts the metabolic network subsystem from published databases. The parameters needed for the simulation are determined using a genetic algorithm to fit the simulation results to the experimental data. We expect that SS-mPMG and SS-GA will help researchers to create relevant metabolic networks and carry out simulations of metabolic reactions derived from metabolomics data.

Sci—Fri PM: Dosimetry—05: Megavoltage electron backscatter: EGSnrc results versus 21 experiments

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

Ali, E. S. M.; The Ottawa Hospital Cancer Centre, Ottawa; Buchenberg, W.

2014-08-15

The accuracy of electron backscatter calculations at megavoltage energies is important for many medical physics applications. In this study, EGSnrc calculations of megavoltage electron backscatter (1–22 MeV) are performed and compared to the data from 21 experiments published between 1954 and 1993 for 25 single elements with atomic numbers from 3 to 92. Typical experimental uncertainties are 15%. For EGSnrc simulations, an ideal detector is assumed, and the most accurate electron physics options are employed, for a combined statistical and systematic uncertainty of 3%. The quantities compared are the backscatter coefficient and the energy spectra (in the backward hemisphere andmore » at specific detector locations). For the backscatter coefficient, the overall agreement is within ±2% in the absolute value of the backscatter coefficient (in per cent), and within 11% of the individual backscatter values. EGSnrc results are systematically on the higher end of the spread of the experimental data, which could be partially from systematic experimental errors discussed in the literature. For the energy spectra, reasonable agreement between simulations and experiments is observed, although there are significant variations in the experimental data. At the lower end of the spectra, simulations are higher than some experimental data, which could be due to reduced experimental sensitivity to lower energy electrons and/or over-estimation by EGSnrc for backscattered secondary electrons. In conclusion, overall good agreement is observed between EGSnrc backscatter calculations and experimental measurements for megavoltage electrons. There is a need for high quality experimental data for the energy spectra of backscattered electrons.« less

Pure Electron Plasmas near Thermal Equilibrium

DTIC Science & Technology

1990-11-01

I University of California, San Diego Institute of Pure and Applied Physical Sciences La Jolla, CA 92093 N 0 (V) Final Technical Report N "Pure...Research/code -..... " 1112AI. VC 1/8/91 ’ , .... i ; () -ii- r INTRODUCTION Since 1982 the plasma group at UCSD has been conducting an experimental and...scale. We have also observed an unusual I = 1 instability which the previously published theoretical literature stated unconditionally was stable. The

Incongruence Between Observers' and Observed Facial Muscle Activation Reduces Recognition of Emotional Facial Expressions From Video Stimuli.

PubMed

Wingenbach, Tanja S H; Brosnan, Mark; Pfaltz, Monique C; Plichta, Michael M; Ashwin, Chris

2018-01-01

According to embodied cognition accounts, viewing others' facial emotion can elicit the respective emotion representation in observers which entails simulations of sensory, motor, and contextual experiences. In line with that, published research found viewing others' facial emotion to elicit automatic matched facial muscle activation, which was further found to facilitate emotion recognition. Perhaps making congruent facial muscle activity explicit produces an even greater recognition advantage. If there is conflicting sensory information, i.e., incongruent facial muscle activity, this might impede recognition. The effects of actively manipulating facial muscle activity on facial emotion recognition from videos were investigated across three experimental conditions: (a) explicit imitation of viewed facial emotional expressions (stimulus-congruent condition), (b) pen-holding with the lips (stimulus-incongruent condition), and (c) passive viewing (control condition). It was hypothesised that (1) experimental condition (a) and (b) result in greater facial muscle activity than (c), (2) experimental condition (a) increases emotion recognition accuracy from others' faces compared to (c), (3) experimental condition (b) lowers recognition accuracy for expressions with a salient facial feature in the lower, but not the upper face area, compared to (c). Participants (42 males, 42 females) underwent a facial emotion recognition experiment (ADFES-BIV) while electromyography (EMG) was recorded from five facial muscle sites. The experimental conditions' order was counter-balanced. Pen-holding caused stimulus-incongruent facial muscle activity for expressions with facial feature saliency in the lower face region, which reduced recognition of lower face region emotions. Explicit imitation caused stimulus-congruent facial muscle activity without modulating recognition. Methodological implications are discussed.

On experimental damage localization by SP2E: Application of H∞ estimation and oblique projections

NASA Astrophysics Data System (ADS)

Lenzen, Armin; Vollmering, Max

2018-05-01

In this article experimental damage localization based on H∞ estimation and state projection estimation error (SP2E) is studied. Based on an introduced difference process, a state space representation is derived for advantageous numerical solvability. Because real structural excitations are presumed to be unknown, a general input is applied therein, which allows synchronization and normalization. Furthermore, state projections are introduced to enhance damage identification. While first experiments to verify method SP2E have already been conducted and published, further laboratory results are analyzed here. Therefore, SP2E is used to experimentally localize stiffness degradations and mass alterations. Furthermore, the influence of projection techniques is analyzed. In summary, method SP2E is able to localize structural alterations, which has been observed by results of laboratory experiments.

Calibrated dilatometer exercise to probe thermoplastic properties of coal in pressurized CO 2

DOE PAGES

Romanov, Vyacheslav N.; Lynn, Ronald J.; Warzinski, Robert P.

2017-07-03

This research was aimed at testing a hypothesis, that at elevated CO 2 pressure coal can soften at temperatures well below those obtained in the presence of other gases. That could have serious negative implications for injection of CO 2 into deep coal seams. Here, we have examined the experimental design issues and procedures used in the previously published studies, and experimentally investigated the physical behavior of a similar coal in the presence of CO 2 as a function of pressure and temperature, using the same high-pressure micro-dilatometer refurbished and carefully calibrated for this purpose. No notable reduction in coalmore » softening temperature was observed in this study.« less

Calibrated dilatometer exercise to probe thermoplastic properties of coal in pressurized CO 2

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

Romanov, Vyacheslav N.; Lynn, Ronald J.; Warzinski, Robert P.

This research was aimed at testing a hypothesis, that at elevated CO 2 pressure coal can soften at temperatures well below those obtained in the presence of other gases. That could have serious negative implications for injection of CO 2 into deep coal seams. Here, we have examined the experimental design issues and procedures used in the previously published studies, and experimentally investigated the physical behavior of a similar coal in the presence of CO 2 as a function of pressure and temperature, using the same high-pressure micro-dilatometer refurbished and carefully calibrated for this purpose. No notable reduction in coalmore » softening temperature was observed in this study.« less

Knowledge engineering tools for reasoning with scientific observations and interpretations: a neural connectivity use case.

PubMed

Russ, Thomas A; Ramakrishnan, Cartic; Hovy, Eduard H; Bota, Mihail; Burns, Gully A P C

2011-08-22

We address the goal of curating observations from published experiments in a generalizable form; reasoning over these observations to generate interpretations and then querying this interpreted knowledge to supply the supporting evidence. We present web-application software as part of the 'BioScholar' project (R01-GM083871) that fully instantiates this process for a well-defined domain: using tract-tracing experiments to study the neural connectivity of the rat brain. The main contribution of this work is to provide the first instantiation of a knowledge representation for experimental observations called 'Knowledge Engineering from Experimental Design' (KEfED) based on experimental variables and their interdependencies. The software has three parts: (a) the KEfED model editor - a design editor for creating KEfED models by drawing a flow diagram of an experimental protocol; (b) the KEfED data interface - a spreadsheet-like tool that permits users to enter experimental data pertaining to a specific model; (c) a 'neural connection matrix' interface that presents neural connectivity as a table of ordinal connection strengths representing the interpretations of tract-tracing data. This tool also allows the user to view experimental evidence pertaining to a specific connection. BioScholar is built in Flex 3.5. It uses Persevere (a noSQL database) as a flexible data store and PowerLoom® (a mature First Order Logic reasoning system) to execute queries using spatial reasoning over the BAMS neuroanatomical ontology. We first introduce the KEfED approach as a general approach and describe its possible role as a way of introducing structured reasoning into models of argumentation within new models of scientific publication. We then describe the design and implementation of our example application: the BioScholar software. This is presented as a possible biocuration interface and supplementary reasoning toolkit for a larger, more specialized bioinformatics system: the Brain Architecture Management System (BAMS).

Knowledge engineering tools for reasoning with scientific observations and interpretations: a neural connectivity use case

PubMed Central

2011-01-01

Background We address the goal of curating observations from published experiments in a generalizable form; reasoning over these observations to generate interpretations and then querying this interpreted knowledge to supply the supporting evidence. We present web-application software as part of the 'BioScholar' project (R01-GM083871) that fully instantiates this process for a well-defined domain: using tract-tracing experiments to study the neural connectivity of the rat brain. Results The main contribution of this work is to provide the first instantiation of a knowledge representation for experimental observations called 'Knowledge Engineering from Experimental Design' (KEfED) based on experimental variables and their interdependencies. The software has three parts: (a) the KEfED model editor - a design editor for creating KEfED models by drawing a flow diagram of an experimental protocol; (b) the KEfED data interface - a spreadsheet-like tool that permits users to enter experimental data pertaining to a specific model; (c) a 'neural connection matrix' interface that presents neural connectivity as a table of ordinal connection strengths representing the interpretations of tract-tracing data. This tool also allows the user to view experimental evidence pertaining to a specific connection. BioScholar is built in Flex 3.5. It uses Persevere (a noSQL database) as a flexible data store and PowerLoom® (a mature First Order Logic reasoning system) to execute queries using spatial reasoning over the BAMS neuroanatomical ontology. Conclusions We first introduce the KEfED approach as a general approach and describe its possible role as a way of introducing structured reasoning into models of argumentation within new models of scientific publication. We then describe the design and implementation of our example application: the BioScholar software. This is presented as a possible biocuration interface and supplementary reasoning toolkit for a larger, more specialized bioinformatics system: the Brain Architecture Management System (BAMS). PMID:21859449

Experimental Design and Data Analysis in Receiver Operating Characteristic Studies: Lessons Learned from Reports in Radiology from 1997 to 20061

PubMed Central

Shiraishi, Junji; Pesce, Lorenzo L.; Metz, Charles E.; Doi, Kunio

2009-01-01

Purpose: To provide a broad perspective concerning the recent use of receiver operating characteristic (ROC) analysis in medical imaging by reviewing ROC studies published in Radiology between 1997 and 2006 for experimental design, imaging modality, medical condition, and ROC paradigm. Materials and Methods: Two hundred ninety-five studies were obtained by conducting a literature search with PubMed with two criteria: publication in Radiology between 1997 and 2006 and occurrence of the phrase “receiver operating characteristic.” Studies returned by the query that were not diagnostic imaging procedure performance evaluations were excluded. Characteristics of the remaining studies were tabulated. Results: Two hundred thirty-three (79.0%) of the 295 studies reported findings based on observers' diagnostic judgments or objective measurements. Forty-three (14.6%) did not include human observers, with most of these reporting an evaluation of a computer-aided diagnosis system or functional data obtained with computed tomography (CT) or magnetic resonance (MR) imaging. The remaining 19 (6.4%) studies were classified as reviews or meta-analyses and were excluded from our subsequent analysis. Among the various imaging modalities, MR imaging (46.0%) and CT (25.7%) were investigated most frequently. Approximately 60% (144 of 233) of ROC studies with human observers published in Radiology included three or fewer observers. Conclusion: ROC analysis is widely used in radiologic research, confirming its fundamental role in assessing diagnostic performance. However, the ROC studies reported in Radiology were not always adequate to support clear and clinically relevant conclusions. © RSNA, 2009 Supplemental material: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.2533081632/-/DC1 PMID:19864510

Do females trade copulations for food? An experimental study on kittiwakes (Rissa tridactyla)

USGS Publications Warehouse

Kempenaers, Bart; Lanctot, Richard B.; Gill, V.A.; Hatch, Shyla A.; Valcu, M.

2007-01-01

Females of many species copulate more frequently than necessary to fertilize their eggs despite the potential costs. Several studies, particularly on socially monogamous birds, have suggested that females obtain immediate material benefits by trading copulations for nutrients or other resources. We experimentally tested this hypothesis by manipulating the food resources available to prelaying female black-legged kittiwakes (Rissa tridactyla). If female kittiwakes trade copulations for courtship feeding because they need the extra resources, well-fed females (experimental group) should be less willing to copulate compared with females that are more food limited (control group). Contrary to our predictions, we found that close to the start of laying experimental females copulated more frequently with their mate than control females. We also observed that males from the experimental group fed their mate at least as often as males from the control group. In experimental pairs, we still observed a positive correlation between the rate of copulation and the rate of courtship feeding. Our results thus refute the immediate material benefits hypothesis. Currently available data are consistent with the hypothesis that prelaying courtship feeding is a form of mating effort. We suggest that the rate of courtship feeding might be a sexually selected trait, on which females base decisions about timing and frequency of copulations, but this remains to be tested. ?? The Author 2006. Published by Oxford University Press on behalf of the International Society for Behavioral Ecology. All rights reserved.

A bioinformatics expert system linking functional data to anatomical outcomes in limb regeneration

PubMed Central

Lobo, Daniel; Feldman, Erica B.; Shah, Michelle; Malone, Taylor J.

2014-01-01

Abstract Amphibians and molting arthropods have the remarkable capacity to regenerate amputated limbs, as described by an extensive literature of experimental cuts, amputations, grafts, and molecular techniques. Despite a rich history of experimental effort, no comprehensive mechanistic model exists that can account for the pattern regulation observed in these experiments. While bioinformatics algorithms have revolutionized the study of signaling pathways, no such tools have heretofore been available to assist scientists in formulating testable models of large‐scale morphogenesis that match published data in the limb regeneration field. Major barriers to preventing an algorithmic approach are the lack of formal descriptions for experimental regenerative information and a repository to centralize storage and mining of functional data on limb regeneration. Establishing a new bioinformatics of shape would significantly accelerate the discovery of key insights into the mechanisms that implement complex regeneration. Here, we describe a novel mathematical ontology for limb regeneration to unambiguously encode phenotype, manipulation, and experiment data. Based on this formalism, we present the first centralized formal database of published limb regeneration experiments together with a user‐friendly expert system tool to facilitate its access and mining. These resources are freely available for the community and will assist both human biologists and artificial intelligence systems to discover testable, mechanistic models of limb regeneration. PMID:25729585

Histochemistry in biology and medicine: a message from the citing journals.

PubMed

Pellicciari, Carlo

2015-12-23

Especially in recent years, biomedical research has taken advantage of the progress in several disciplines, among which microscopy and histochemistry. To assess the influence of histochemistry in the biomedical field, the articles published during the period 2011-2015 have been selected from different databases and grouped by subject categories: as expected, biological and biomedical studies where histochemistry has been used as a major experimental approach include a wide of basic and applied researches on both humans and other animal or plant organisms. To better understand the impact of histochemical publications onto the different biological and medical disciplines, it was useful to look at the journals where the articles published in a multidisciplinary journal of histochemistry have been cited: it was observed that, in the five-years period considered, 20% only of the citations were in histochemical periodicals, the remaining ones being in journals of Cell & Tissue biology,  general and experimental Medicine, Oncology, Biochemistry & Molecular biology, Neurobiology, Anatomy & Morphology, Pharmacology & Toxicology, Reproductive biology, Veterinary sciences, Physiology, Endocrinology, Tissue engineering & Biomaterials,  as well as in multidisciplinary journals.It is easy to foresee that also in the future the histochemical journals will be an attended forum for basic and applied scientists in the biomedical field. It will be crucial that these journals be open to an audience as varied as possible, publishing articles on the application of refined techniques to very different experimental models: this will stimulate non-histochemist scientists to approach histochemistry whose application horizon could expand to novel and possibly exclusive subjects.

Histochemistry in Biology and Medicine: A Message From the Citing Journals

PubMed Central

2015-01-01

Especially in recent years, biomedical research has taken advantage of the progress in several disciplines, among which microscopy and histochemistry. To assess the influence of histochemistry in the biomedical field, the articles published during the period 2011-2015 have been selected from different databases and grouped by subject categories. As expected, biological and biomedical studies where histochemistry has been used as a major experimental approach include a wide range of basic and applied researches on both humans and other animal or plant organisms. To better understand the impact of histochemical publications onto the different biological and medical disciplines, it was useful to look at the journals where the articles published in a multidisciplinary journal of histochemistry have been cited: it was observed that, in the five-years period considered, 20% only of the citations were in histochemical periodicals, the remaining ones being in journals of Cell & Tissue biology, general and experimental Medicine, Oncology, Biochemistry & Molecular biology, Neurobiology, Anatomy & Morphology, Pharmacology & Toxicology, Reproductive biology, Veterinary sciences, Physiology, Endocrinology, Tissue engineering & Biomaterials, as well as in multidisciplinary journals. It is easy to foresee that also in the future the histochemical journals will be an attended forum for basic and applied scientists in the biomedical field. It will be crucial that these journals be open to an audience as varied as possible, publishing articles on the application of refined techniques to very different experimental models: this will stimulate non-histochemist scientists to approach histochemistry whose application horizon could expand to novel and possibly exclusive subjects. PMID:26708189

Demonstrated high performance of gas-filled rugby-shaped hohlraums on Omega

NASA Astrophysics Data System (ADS)

Philippe, F.; Tassin, V.; Depierreux, S.; Gauthier, P.; Masson-Laborde, P. E.; Monteil, M. C.; Seytor, P.; Villette, B.; Lasinski, B.; Park, H. S.; Ross, J. S.; Amendt, P.; Döppner, T.; Hinkel, D. E.; Wallace, R.; Williams, E.; Michel, P.; Frenje, J.; Gatu-Johnson, M.; Li, C. K.; Petrasso, R.; Glebov, V.; Sorce, C.; Stoeckl, C.; Nikroo, A.; Giraldez, E.

2014-07-01

A direct experimental comparison of rugby-shaped and cylindrical shaped gas-filled hohlraums on the Omega laser facility demonstrates that higher coupling and minimal backscatter can be achieved in the rugby geometry, leading to significantly enhanced implosion performance. A nearly 50% increase of x-ray drive is associated with earlier bangtime and increase of neutron production. The observed drive enhancement from rugby geometry in this study is almost twice stronger than in previously published results.

Evaluating Simulation Methodologies to Determine Best Strategies to Maximize Student Learning.

PubMed

Scherer, Yvonne K; Foltz-Ramos, Kelly; Fabry, Donna; Chao, Ying-Yu

2016-01-01

Limited evidence exists as to the most effective ways to provide simulation experiences to maximize student learning. This quasi-experimental study investigated 2 different strategies repeated versus 1 exposure and participation versus observation on student outcomes following exposure to a high-fidelity acute asthma exacerbation of asthma scenario. Immediate repeated exposure resulted in significantly higher scores on knowledge, student satisfaction and self-confidence, and clinical performance measures than a single exposure. Significant intergroup differences were found on participants' satisfaction and self-confidence as compared with observers. Implications for nurse educators include expanding the observer role when designing repeated exposure to simulations and integrating technical, cognitive, and behavioral outcomes as a way for faculty to evaluate students' clinical performance. Published by Elsevier Inc.

A Ubiquitous Sensor Network Platform for Integrating Smart Devices into the Semantic Sensor Web

PubMed Central

de Vera, David Díaz Pardo; Izquierdo, Álvaro Sigüenza; Vercher, Jesús Bernat; Gómez, Luis Alfonso Hernández

2014-01-01

Ongoing Sensor Web developments make a growing amount of heterogeneous sensor data available to smart devices. This is generating an increasing demand for homogeneous mechanisms to access, publish and share real-world information. This paper discusses, first, an architectural solution based on Next Generation Networks: a pilot Telco Ubiquitous Sensor Network (USN) Platform that embeds several OGC® Sensor Web services. This platform has already been deployed in large scale projects. Second, the USN-Platform is extended to explore a first approach to Semantic Sensor Web principles and technologies, so that smart devices can access Sensor Web data, allowing them also to share richer (semantically interpreted) information. An experimental scenario is presented: a smart car that consumes and produces real-world information which is integrated into the Semantic Sensor Web through a Telco USN-Platform. Performance tests revealed that observation publishing times with our experimental system were well within limits compatible with the adequate operation of smart safety assistance systems in vehicles. On the other hand, response times for complex queries on large repositories may be inappropriate for rapid reaction needs. PMID:24945678

A ubiquitous sensor network platform for integrating smart devices into the semantic sensor web.

PubMed

de Vera, David Díaz Pardo; Izquierdo, Alvaro Sigüenza; Vercher, Jesús Bernat; Hernández Gómez, Luis Alfonso

2014-06-18

Ongoing Sensor Web developments make a growing amount of heterogeneous sensor data available to smart devices. This is generating an increasing demand for homogeneous mechanisms to access, publish and share real-world information. This paper discusses, first, an architectural solution based on Next Generation Networks: a pilot Telco Ubiquitous Sensor Network (USN) Platform that embeds several OGC® Sensor Web services. This platform has already been deployed in large scale projects. Second, the USN-Platform is extended to explore a first approach to Semantic Sensor Web principles and technologies, so that smart devices can access Sensor Web data, allowing them also to share richer (semantically interpreted) information. An experimental scenario is presented: a smart car that consumes and produces real-world information which is integrated into the Semantic Sensor Web through a Telco USN-Platform. Performance tests revealed that observation publishing times with our experimental system were well within limits compatible with the adequate operation of smart safety assistance systems in vehicles. On the other hand, response times for complex queries on large repositories may be inappropriate for rapid reaction needs.

Spin-up flow of ferrofluids: Asymptotic theory and experimental measurements

NASA Astrophysics Data System (ADS)

Chaves, Arlex; Zahn, Markus; Rinaldi, Carlos

2008-05-01

We treat the flow of ferrofluid in a cylindrical container subjected to a uniform rotating magnetic field, commonly referred to as spin-up flow. A review of theoretical and experimental results published since the phenomenon was first observed in 1967 shows that the experimental data from surface observations of tracer particles are inadequate for the assessment of bulk flow theories. We present direct measurements of the bulk flow by using the ultrasound velocity profile method, and torque measurements for water and kerosene based ferrofluids, showing the fluid corotating with the field in a rigid-body-like fashion throughout most of the bulk region of the container, except near the air-fluid interface, where it was observed to counter-rotate. We obtain an extension of the spin diffusion theory of Zaitsev and Shliomis, using the regular perturbation method. The solution is rigorously valid for αK≪√3/2 , where αK is the Langevin parameter evaluated by using the applied field magnitude, and provides a means for obtaining successively higher contributions of the nonlinearity of the equilibrium magnetization response and the spin-magnetization coupling in the magnetization relaxation equation. Because of limitations in the sensitivity of our apparatus, experiments were carried out under conditions for which α ˜1. Still, under such conditions the predictions of the analysis are in good qualitative agreement with the experimental observations. An estimate of the spin viscosity is obtained from comparison of flow measurements and theoretical results of the extrapolated wall velocity from the regular perturbation method. The estimated value lies in the range of 10-8-10-12kgms-1 and is several orders of magnitude higher than that obtained from dimensional analysis of a suspension of noninteracting particles in a Newtonian fluid.

A Cross-Sectional Analysis of Publication Types in Quality Improvement Journals.

PubMed

Wong, Christopher J; White, Andrew A; Merel, Susan E; Brock, Douglas M; Staiger, Thomas O

2016-07-01

Despite widespread engagement in quality improvement activities, little is known about the designs of studies currently published in quality improvement journals. This study's goal is to establish the prevalence of the types of research conducted in articles published in journals dedicated to quality improvement. A cross-sectional analysis was performed of 145 research articles published in 11 quality improvement journals in 2011. The majority of study designs were considered pre-experimental (95%), with a small percentage of quasi-experimental and experimental designs. Of the studies that reported the results of an intervention (n = 60), the most common research designs were pre-post studies (33%) and case studies (25%). There were few randomized controlled trials or quasi-experimental study designs (12% of intervention studies). These results suggest that there are opportunities for increased use of quasi-experimental study designs. © The Author(s) 2015.

An artificial-intelligence technique for qualitatively deriving enzyme kinetic mechanisms from initial-velocity measurements and its application to hexokinase.

PubMed Central

Garfinkel, L; Cohen, D M; Soo, V W; Garfinkel, D; Kulikowski, C A

1989-01-01

We have developed a computer method based on artificial-intelligence techniques for qualitatively analysing steady-state initial-velocity enzyme kinetic data. We have applied our system to experiments on hexokinase from a variety of sources: yeast, ascites and muscle. Our system accepts qualitative stylized descriptions of experimental data, infers constraints from the observed data behaviour and then compares the experimentally inferred constraints with corresponding theoretical model-based constraints. It is desirable to have large data sets which include the results of a variety of experiments. Human intervention is needed to interpret non-kinetic information, differences in conditions, etc. Different strategies were used by the several experimenters whose data was studied to formulate mechanisms for their enzyme preparations, including different methods (product inhibitors or alternate substrates), different experimental protocols (monitoring enzyme activity differently), or different experimental conditions (temperature, pH or ionic strength). The different ordered and rapid-equilibrium mechanisms proposed by these experimenters were generally consistent with their data. On comparing the constraints derived from the several experimental data sets, they are found to be in much less disagreement than the mechanisms published, and some of the disagreement can be ascribed to different experimental conditions (especially ionic strength). PMID:2690819

James L. Tuck Los Alamos ball lightning pioneer

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

Baker, D.A.

1999-07-01

James Tuck was well known for starting the Project Sherwood group at Los Alamos Scientific Laboratory in 1952. This group was formed to study and develop concepts for controlled fusion energy. In his later years after retiring from Controlled Fusion Division, he continued research at Los Alamos on the topic of ball lightning. He traveled widely giving lectures on both observations of others and his own experimental efforts. He collected anecdotal observations obtained from those in his lecture audiences during his travels and from responses from newspaper articles where he asked for specific information from ball lightning observers. He finallymore » cut off this collection of data when the number of responses became overwhelming. The author's primary publication on ball lightning was a short laboratory report. He planned on publishing a book on the subject but this was never completed before his death. Tuck focused his experimental effort on attempting to duplicate the production of plasma balls claimed to be observed in US Navy submarines when a switch was opened under overload conditions with battery power. During lunch breaks he made use of a Los Alamos N-division battery bank facility to mock up a submarine power pack and switch gear. This non-funded effort was abruptly terminated when an explosion occurred in the facility. An overview of Tuck's research and views will be given. The flavor Jim's personality as well as a ball produced with his experimental apparatus will be shown using video chips.« less

Combinatorial Broadening Mechanism of O-H Stretching Bands in H-Bonded Molecular Clusters

NASA Astrophysics Data System (ADS)

Pitsevich, G. A.; Doroshenko, I. Yu.; Pogorelov, V. E.; Pettersson, L. G. M.; Sablinskas, V.; Sapeshko, V. V.; Balevicius, V.

2016-07-01

A new mechanism for combinatorial broadening of donor-OH stretching-vibration absorption bands in molecular clusters with H-bonds is proposed. It enables the experimentally observed increase of the O-H stretching-vibration bandwidth with increasing number of molecules in H-bonded clusters to be explained. Knowledge of the half-width of the OH stretching-vibration absorption band in the dimer and the number of H-bonds in the analyzed cluster is suffi cient in the zeroth-order approximation to estimate the O-H stretching-absorption bands in clusters containing several molecules. Good agreement between the calculated and published experimental half-widths of the OH stretching-vibration absorption bands in MeOH and PrOH clusters was obtained using this approach.

Dalton's disputed nitric oxide experiments and the origins of his atomic theory.

PubMed

Usselman, Melvyn C; Leaist, Derek G; Watson, Katherine D

2008-01-11

In 1808 John Dalton published his first general account of chemical atomic theory, a cornerstone of modern chemistry. The theory originated in his earlier studies of the properties of atmospheric gases. In 1803 Dalton discovered that oxygen combined with either one or two volumes of nitric oxide in closed vessels over water and this pioneering observation of integral multiple proportions provided important experimental evidence for his incipient atomic ideas. Previous attempts to reproduce Dalton's experiments have been unsuccessful and some commentators have concluded the results were fraudulent. We report a successful reconstruction of Dalton's experiments and provide an analysis exonerating him of any scientific misconduct. But we conclude that Dalton, already thinking atomistically, adjusted experimental conditions to obtain the integral combining proportions.

Effects of configuration interaction on photoabsorption spectra in the continuum

NASA Astrophysics Data System (ADS)

Komninos, Yannis; Nicolaides, Cleanthes A.

2004-10-01

It is pointed out that the proper interpretation of a recently published experimental spectrum from the multilaser photoionization of Sr [Eichmann , Phys. Rev. Lett. 90, 233004 (2003)] must account for a radiative transition between two autoionizing states. The application of orthonormality selection rules and of configuration-interaction theory involving the continuous spectrum and the quasicontinuum of the upper part of Rydberg series explains quantitatively the appearance, the shape, and the variation of heights of the observed peaks of resonances.

Characterization of Ion-Implanted Semiconductors

DTIC Science & Technology

1980-11-01

samples having an ion dose of I x 14 cm or ahbove. The changes in the poSition of the peak concentration and raigaii tude rup!resuua cimp i,:ated problems...investigations, some aiionuil.iQS were observed in connection with the FET-pattern geometry. A paper was published on this work and is included in Appendix E of...I NTRODUCTIOIN During the past twenty years, a great deal of interest has existed in both I experimentAl and theoretical inve.stigations o) the

Steady-state and second-sound measurements of Kapitza resistance

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

Katerberg, James Alan

1980-01-01

Published steady-state (dc) and second-sound (ac) measurements of the Kapitza resistance (R K) have differed in reports of the temperature dependence of R K. The two types of measurements were also seen to conflict on the measured effects of sample damage on the magnitude of R K. To resolve these differences, measurements of R K have been made using both techniques on the same sample, during the same experimental run. Our measurements, made on copper-liquid helium interfaces from 1.1 to 2.1 K, show excellent agreement between the dc and ac results. No evidence is seen for a frequency-dependent Kapitza resistance.more » Our measurements show an increase in R K when the sample is damaged, agreeing with published ac measurements, but disagreeing with published dc measurements. The temperature dependence of R K in our measurements is approximately T -3 from 1.5 to 2.1 K, in agreement with published dc measurements. A T -4 dependence has been seen in the published ac experiments. In our experiments, a T -4 dependence is observed only when second sound is coupled from the generating cavity to the helium bath.« less

Synaptic Transmission Optimization Predicts Expression Loci of Long-Term Plasticity.

PubMed

Costa, Rui Ponte; Padamsey, Zahid; D'Amour, James A; Emptage, Nigel J; Froemke, Robert C; Vogels, Tim P

2017-09-27

Long-term modifications of neuronal connections are critical for reliable memory storage in the brain. However, their locus of expression-pre- or postsynaptic-is highly variable. Here we introduce a theoretical framework in which long-term plasticity performs an optimization of the postsynaptic response statistics toward a given mean with minimal variance. Consequently, the state of the synapse at the time of plasticity induction determines the ratio of pre- and postsynaptic modifications. Our theory explains the experimentally observed expression loci of the hippocampal and neocortical synaptic potentiation studies we examined. Moreover, the theory predicts presynaptic expression of long-term depression, consistent with experimental observations. At inhibitory synapses, the theory suggests a statistically efficient excitatory-inhibitory balance in which changes in inhibitory postsynaptic response statistics specifically target the mean excitation. Our results provide a unifying theory for understanding the expression mechanisms and functions of long-term synaptic transmission plasticity. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Experimental conformational energy maps of proteins and peptides.

PubMed

Balaji, Govardhan A; Nagendra, H G; Balaji, Vitukudi N; Rao, Shashidhar N

2017-06-01

We have presented an extensive analysis of the peptide backbone dihedral angles in the PDB structures and computed experimental Ramachandran plots for their distributions seen under a various constraints on X-ray resolution, representativeness at different sequence identity percentages, and hydrogen bonding distances. These experimental distributions have been converted into isoenergy contour plots using the approach employed previously by F. M. Pohl. This has led to the identification of energetically favored minima in the Ramachandran (ϕ, ψ) plots in which global minima are predominantly observed either in the right-handed α-helical or the polyproline II regions. Further, we have identified low energy pathways for transitions between various minima in the (ϕ,ψ) plots. We have compared and presented the experimental plots with published theoretical plots obtained from both molecular mechanics and quantum mechanical approaches. In addition, we have developed and employed a root mean square deviation (RMSD) metric for isoenergy contours in various ranges, as a measure (in kcal.mol -1 ) to compare any two plots and determine the extent of correlation and similarity between their isoenergy contours. In general, we observe a greater degree of compatibility with experimental plots for energy maps obtained from molecular mechanics methods compared to most quantum mechanical methods. The experimental energy plots we have investigated could be helpful in refining protein structures obtained from X-ray, NMR, and electron microscopy and in refining force field parameters to enable simulations of peptide and protein structures that have higher degree of consistency with experiments. Proteins 2017; 85:979-1001. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Kinetic analysis of hyperpolarized data with minimum a priori knowledge: Hybrid maximum entropy and nonlinear least squares method (MEM/NLS).

PubMed

Mariotti, Erika; Veronese, Mattia; Dunn, Joel T; Southworth, Richard; Eykyn, Thomas R

2015-06-01

To assess the feasibility of using a hybrid Maximum-Entropy/Nonlinear Least Squares (MEM/NLS) method for analyzing the kinetics of hyperpolarized dynamic data with minimum a priori knowledge. A continuous distribution of rates obtained through the Laplace inversion of the data is used as a constraint on the NLS fitting to derive a discrete spectrum of rates. Performance of the MEM/NLS algorithm was assessed through Monte Carlo simulations and validated by fitting the longitudinal relaxation time curves of hyperpolarized [1-(13) C] pyruvate acquired at 9.4 Tesla and at three different flip angles. The method was further used to assess the kinetics of hyperpolarized pyruvate-lactate exchange acquired in vitro in whole blood and to re-analyze the previously published in vitro reaction of hyperpolarized (15) N choline with choline kinase. The MEM/NLS method was found to be adequate for the kinetic characterization of hyperpolarized in vitro time-series. Additional insights were obtained from experimental data in blood as well as from previously published (15) N choline experimental data. The proposed method informs on the compartmental model that best approximate the biological system observed using hyperpolarized (13) C MR especially when the metabolic pathway assessed is complex or a new hyperpolarized probe is used. © 2014 The Authors. Magnetic Resonance in Medicine published by Wiley Periodicals, Inc.

Effects of self-adjusting file, Mtwo, and ProTaper on the root canal wall.

PubMed

Hin, Ellemieke S; Wu, Min-Kai; Wesselink, Paul R; Shemesh, Hagay

2013-02-01

The purpose of this ex vivo study was to observe the incidence of cracks in root dentin after root canal preparation with hand files, self-adjusting file (SAF), ProTaper, and Mtwo. One hundred extracted mandibular premolars with single canals were randomly selected. Two angulated radiographs were taken for each tooth, and the width of the canal was measured at 9 mm from the apex. Five groups of 20 teeth each were comparable in canal width. The control group was left unprepared. Four experimental groups were instrumented with hand files, ProTaper, Mtwo, and SAF. Roots were then sectioned horizontally and observed under a microscope. The presence of dentinal cracks and their location were noted. The difference between the experimental groups was analyzed with a χ(2) test. No cracks were observed in the control group. In the experimental groups, ProTaper, Mtwo, and SAF caused cracks in 35%, 25%, and 10% of teeth, respectively. The hand-file group did not show any dentinal cracks (P < .0001). ProTaper and Mtwo caused more cracks than hand files (P < .05), but SAF did not (P > .05). Instrumentation of root canals with SAF, Mtwo, and ProTaper could cause damage to root canal dentin. SAF has a tendency to cause less dentinal cracks as compared with ProTaper or Mtwo. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Preface: Deep Slab and Mantle Dynamics

NASA Astrophysics Data System (ADS)

Suetsugu, Daisuke; Bina, Craig R.; Inoue, Toru; Wiens, Douglas A.

2010-11-01

We are pleased to publish this special issue of the journal Physics of the Earth and Planetary Interiors entitled "Deep Slab and Mantle Dynamics". This issue is an outgrowth of the international symposium "Deep Slab and Mantle Dynamics", which was held on February 25-27, 2009, in Kyoto, Japan. This symposium was organized by the "Stagnant Slab Project" (SSP) research group to present the results of the 5-year project and to facilitate intensive discussion with well-known international researchers in related fields. The SSP and the symposium were supported by a Grant-in-Aid for Scientific Research (16075101) from the Ministry of Education, Culture, Sports, Science and Technology of the Japanese Government. In the symposium, key issues discussed by participants included: transportation of water into the deep mantle and its role in slab-related dynamics; observational and experimental constraints on deep slab properties and the slab environment; modeling of slab stagnation to constrain its mechanisms in comparison with observational and experimental data; observational, experimental and modeling constraints on the fate of stagnant slabs; eventual accumulation of stagnant slabs on the core-mantle boundary and its geodynamic implications. This special issue is a collection of papers presented in the symposium and other papers related to the subject of the symposium. The collected papers provide an overview of the wide range of multidisciplinary studies of mantle dynamics, particularly in the context of subduction, stagnation, and the fate of deep slabs.

The use of nonhuman primates in research on seasonal, pandemic and avian influenza, 1893-2014.

PubMed

Davis, A Sally; Taubenberger, Jeffery K; Bray, Mike

2015-05-01

Attempts to reproduce the features of human influenza in laboratory animals date from the early 1890s, when Richard Pfeiffer inoculated apes with bacteria recovered from influenza patients and produced a mild respiratory illness. Numerous studies employing nonhuman primates (NHPs) were performed during the 1918 pandemic and the following decade. Most used bacterial preparations to infect animals, but some sought a filterable agent for the disease. Since the viral etiology of influenza was established in the early 1930s, studies in NHPs have been supplemented by a much larger number of experiments in mice, ferrets and human volunteers. However, the emergence of a novel swine-origin H1N1 influenza virus in 1976 and the highly pathogenic H5N1 avian influenza virus in 1997 stimulated an increase in NHP research, because these agents are difficult to study in naturally infected patients and cannot be administered to human volunteers. In this paper, we review the published literature on the use of NHPs in influenza research from 1893 through the end of 2014. The first section summarizes observational studies of naturally occurring influenza-like syndromes in wild and captive primates, including serologic investigations. The second provides a chronological account of experimental infections of NHPs, beginning with Pfeiffer's study and covering all published research on seasonal and pandemic influenza viruses, including vaccine and antiviral drug testing. The third section reviews experimental infections of NHPs with avian influenza viruses that have caused disease in humans since 1997. The paper concludes with suggestions for further studies to more clearly define and optimize the role of NHPs as experimental animals for influenza research. Published by Elsevier B.V.

LEPER: Library of Experimental PhasE Relations

NASA Astrophysics Data System (ADS)

Davis, F.; Gordon, S.; Mukherjee, S.; Hirschmann, M.; Ghiorso, M.

2006-12-01

The Library of Experimental PhasE Relations (LEPER) seeks to compile published experimental determinations of magmatic phase equilibria and provide those data on the web with a searchable and downloadable interface. Compiled experimental data include the conditions and durations of experiments, the bulk compositions of experimental charges, and the identity, compositions and proportions of phases observed, and, where available, estimates of experimental and analytical uncertainties. Also included are metadata such as the type of experimental device, capsule material, and method(s) of quantitative analysis. The database may be of use to practicing experimentalists as well as the wider Earth science community. Experimentalists may find the data useful for planning new experiments and will easily be able to compare their results to the full body of previous experimentnal data. Geologists may use LEPER to compare rocks sampled in the field with experiments performed on similar bulk composition or with experiments that produced similar-composition product phases. Modelers may use LEPER to parameterize partial melting of various lithologies. One motivation for compiling LEPER is for calibration of updated and revised versions of MELTS, however, it is hoped that the availability of LEPER will facilitate formulation and calibration of additional thermodynamic or empirical models of magmatic phase relations and phase equilibria, geothermometers and more. Data entry for LEPER is occuring presently: As of August, 2006, >6200 experiments have been entered, chiefly from work published between 1997 and 2005. A prototype web interface has been written and beta release on the web is anticipated in Fall, 2006. Eventually, experimentalists will be able to submit their new experimental data to the database via the web. At present, the database contains only data pertaining to the phase equilibria of silicate melts, but extension to other experimental data involving other fluids or sub-solidus phase equilibria may be contemplated. Also, the data are at present limited to natural or near-natural systems, but in the future, extension to synthetic (i.e., CMAS, etc.) systems is also possible. Each would depend in part on whether there is community demand for such databases. A trace element adjunct to LEPER is presently in planning stages.

Single-Case Experimental Designs: A Systematic Review of Published Research and Current Standards

ERIC Educational Resources Information Center

Smith, Justin D.

2012-01-01

This article systematically reviews the research design and methodological characteristics of single-case experimental design (SCED) research published in peer-reviewed journals between 2000 and 2010. SCEDs provide researchers with a flexible and viable alternative to group designs with large sample sizes. However, methodological challenges have…

Extended charge banking model of dual path shocks for implantable cardioverter defibrillators

PubMed Central

Dosdall, Derek J; Sweeney, James D

2008-01-01

Background Single path defibrillation shock methods have been improved through the use of the Charge Banking Model of defibrillation, which predicts the response of the heart to shocks as a simple resistor-capacitor (RC) circuit. While dual path defibrillation configurations have significantly reduced defibrillation thresholds, improvements to dual path defibrillation techniques have been limited to experimental observations without a practical model to aid in improving dual path defibrillation techniques. Methods The Charge Banking Model has been extended into a new Extended Charge Banking Model of defibrillation that represents small sections of the heart as separate RC circuits, uses a weighting factor based on published defibrillation shock field gradient measures, and implements a critical mass criteria to predict the relative efficacy of single and dual path defibrillation shocks. Results The new model reproduced the results from several published experimental protocols that demonstrated the relative efficacy of dual path defibrillation shocks. The model predicts that time between phases or pulses of dual path defibrillation shock configurations should be minimized to maximize shock efficacy. Discussion Through this approach the Extended Charge Banking Model predictions may be used to improve dual path and multi-pulse defibrillation techniques, which have been shown experimentally to lower defibrillation thresholds substantially. The new model may be a useful tool to help in further improving dual path and multiple pulse defibrillation techniques by predicting optimal pulse durations and shock timing parameters. PMID:18673561

Transcriptome-wide investigation of genomic imprinting in chicken.

PubMed

Frésard, Laure; Leroux, Sophie; Servin, Bertrand; Gourichon, David; Dehais, Patrice; Cristobal, Magali San; Marsaud, Nathalie; Vignoles, Florence; Bed'hom, Bertrand; Coville, Jean-Luc; Hormozdiari, Farhad; Beaumont, Catherine; Zerjal, Tatiana; Vignal, Alain; Morisson, Mireille; Lagarrigue, Sandrine; Pitel, Frédérique

2014-04-01

Genomic imprinting is an epigenetic mechanism by which alleles of some specific genes are expressed in a parent-of-origin manner. It has been observed in mammals and marsupials, but not in birds. Until now, only a few genes orthologous to mammalian imprinted ones have been analyzed in chicken and did not demonstrate any evidence of imprinting in this species. However, several published observations such as imprinted-like QTL in poultry or reciprocal effects keep the question open. Our main objective was thus to screen the entire chicken genome for parental-allele-specific differential expression on whole embryonic transcriptomes, using high-throughput sequencing. To identify the parental origin of each observed haplotype, two chicken experimental populations were used, as inbred and as genetically distant as possible. Two families were produced from two reciprocal crosses. Transcripts from 20 embryos were sequenced using NGS technology, producing ∼200 Gb of sequences. This allowed the detection of 79 potentially imprinted SNPs, through an analysis method that we validated by detecting imprinting from mouse data already published. However, out of 23 candidates tested by pyrosequencing, none could be confirmed. These results come together, without a priori, with previous statements and phylogenetic considerations assessing the absence of genomic imprinting in chicken.

Improving methods to evaluate the impacts of plant invasions: lessons from 40 years of research

PubMed Central

Stricker, Kerry Bohl; Hagan, Donald; Flory, S. Luke

2015-01-01

Methods used to evaluate the ecological impacts of biological invasions vary widely from broad-scale observational studies to removal experiments in invaded communities and experimental additions in common gardens and greenhouses. Different methods provide information at diverse spatial and temporal scales with varying levels of reliability. Thus, here we provide a synthetic and critical review of the methods used to evaluate the impacts of plant invasions and provide recommendations for future research. We review the types of methods available and report patterns in methods used, including the duration and spatial scale of studies and plant functional groups examined, from 410 peer-reviewed papers published between 1971 and 2011. We found that there has been a marked increase in papers published on plant invasion impacts since 2003 and that more than half of all studies employed observational methods while <5 % included predictive modelling. Most of the studies were temporally and spatially restricted with 51 % of studies lasting <1 year and almost half of all studies conducted in plots or mesocosms <1 m2. There was also a bias in life form studied: more than 60 % of all studies evaluated impacts of invasive forbs and graminoids while <16 % focused on invasive trees. To more effectively quantify invasion impacts, we argue that longer-term experimental research and more studies that use predictive modelling and evaluate impacts of invasions on ecosystem processes and fauna are needed. Combining broad-scale observational studies with experiments and predictive modelling may provide the most insight into invasion impacts for policy makers and land managers seeking to reduce the effects of plant invasions. PMID:25829379

Effectiveness of influenza vaccination for preventing influenza-related complications in people with asthma: a systematic review protocol.

PubMed

Vasileiou, Eleftheria; Sheikh, Aziz; Butler, Chris; von Wissmann, Beatrix; McMenamin, Jim; Ritchie, Lewis; Tian, Lilly; Simpson, Colin

2016-03-29

Influenza vaccination is administered annually as a preventive measure against influenza infection and influenza-related complications in high-risk individuals, such as those with asthma. However, the effectiveness of influenza vaccination in people with asthma against influenza-related complications is still not well established. We will search the following databases: MEDLINE (Ovid), EMBASE (Ovid), Cumulative Index to Nursing and Allied Health Literature (CINAHL), Cochrane Central Register of Controlled Trials (CENTRAL), Scopus, Cochrane Database of Systematic Reviews (CDSR), Web of Science Core Collection, Science direct, WHO Library Information System (WHOLIS), Global Health Library and Chinese databases (CNKI, Wanfang and ChongQing VIP) from Jan 1970 to Jan 2016 for observational and experimental studies on effectiveness of influenza vaccine in people with asthma. The identification of studies will be complemented with the searching of the reference lists and citations, and contacting influenza vaccine manufacturers to identify unpublished or ongoing studies. Two reviewers will extract data and appraise the quality of each study independently. Separate meta-analyses will be undertaken for observational and experimental evidence using fixed-effect or random-effects models, as appropriate. Formal ethical approval is not required, as primary data will not be collected. The review will be disseminated in peer-reviewed publications and conference presentations. 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/

Single subject controlled experiments in aphasia: The science and the state of the science

PubMed Central

Thompson, Cynthia K.

2007-01-01

This paper discusses the use of single subject controlled experimental designs for investigating the effect of treatment for aphasia. A brief historical perspective is presented, followed by discussions of the advantages and disadvantages of single subject and group approaches, the basic requirements of single subject experimental research, and crucial considerations in design selection. In the final sections, results of reviews of published single subject controlled experiments are discussed, with emphasis on internal validity issues, the number of participants enrolled in published studies, operational specification of the dependent and independent variables, and reliability of measurement. Learning outcomes As a result of reading this paper, the participant will: (1) understand the mechanisms required for demonstration of internal and external validity using single subject controlled experimental designs, (2) become familiar with the basic requirements of single subject controlled experimental research, (3) understand the types of single subject controlled experimental designs that are the most appropriate for studying the effects of treatment for aphasia, and (4) become familiar with trends in the published aphasia treatment literature in which single subject controlled experimental designs have been used. PMID:16635494

Kinetics of uncatalyzed thermochemical sulfate reduction by sulfur-free paraffin

USGS Publications Warehouse

Zhang, Tongwei; Ellis, Geoffrey S.; Ma, Qisheng; Amrani, Alon; Tang, Yongchun

2012-01-01

To determine kinetic parameters of sulfate reduction by hydrocarbons (HC) without the initial presence of low valence sulfur, we carried out a series of isothermal gold-tube hydrous-pyrolysis experiments at 320, 340, and 360 °C under a constant confined pressure of 24.1 MPa. The reactants used consisted of saturated HC (sulfur-free) and CaSO4 in an aqueous solution buffered to three different pH conditions without the addition of elemental sulfur (S8) or H2S as initiators. H2S produced in the course of reaction was proportional to the extent of the reduction of CaSO4 that was initially the only sulfur-containing reactant. Our results show that the in situ pH of the aqueous solution (herein, in situ pH refers to the calculated pH value of the aqueous solution at certain experimental conditions) can significantly affect the rate of the thermochemical sulfate reduction (TSR) reaction. A substantial increase in the TSR reaction rate was observed with a decrease in the in situ pH. Our experimental results show that uncatalyzed TSR is a first-order reaction. The temperature dependence of experimentally measured H2S yields from sulfate reduction was fit with the Arrhenius equation. The determined activation energy for HC (sulfur-free) reacting with View the MathML sourceHSO4− in our experiments is 246.6 kJ/mol at pH values ranging from 3.0 to 3.5, which is slightly higher than the theoretical value of 227.0 kJ/mol using ab initio quantum chemical calculations on a similar reaction. Although the availability of reactive sulfate significantly affects the rate of reaction, a consistent rate constant was determined by accounting for the HSO4− ion concentration. Our experimental and theoretical approach to the determination of the kinetics of TSR is further validated by a reevaluation of several published experimental TSR datasets without the initial presence of native sulfur or H2S. When the effect of reactive sulfate concentration is appropriately accounted for, the published experimental TSR data yield kinetic parameters that are consistent with our values. Assuming MgSO4 contact-ion-pair ([MgSO4]CIP) as the reactive form of sulfate in petroleum reservoir formation waters, a simple extrapolation of our experimentally derived HSO4− reduction kinetics as a proxy for [MgSO4]CIP to geologically reasonable conditions predicts onset temperatures (130–140 °C) that are comparable to those observed in nature.

The Traditional Scholarly Journal Publishers Legitimize the Web.

ERIC Educational Resources Information Center

Peek, Robin; Pomerantz, Jeffrey; Paling, Stephen

1998-01-01

Examines the entry of the major academic publishing houses into World Wide Web publishing. Suggests that early experimentation in Web publishing began unevenly with areas that needed improvement. Concludes with a discussion about the implications of the traditional academic publisher's presence on the Web. (Author/AEF)

Pain empathy in schizophrenia: an fMRI study.

PubMed

Horan, William P; Jimenez, Amy M; Lee, Junghee; Wynn, Jonathan K; Eisenberger, Naomi I; Green, Michael F

2016-05-01

Although it has been proposed that schizophrenia is characterized by impaired empathy, several recent studies found intact neural responses on tasks measuring the affective subdomain of empathy. This study further examined affective empathy in 21 schizophrenia outpatients and 21 healthy controls using a validated pain empathy paradigm with two components: (i) observing videos of people described as medical patients who were receiving a painful sound stimulation treatment; (ii) listening to the painful sounds (to create regions of interest). The observing videos component incorporated experimental manipulations of perspective taking (instructions to imagine 'Self' vs 'Other' experiencing pain) and cognitive appraisal (information about whether treatment was 'Effective' vs 'Not Effective'). When considering activation across experimental conditions, both groups showed similar dorsal anterior cingulate cortex (dACC) and anterior insula (AI) activation while merely observing others in pain. However, there were group differences associated with perspective taking: controls showed relatively greater dACC and AI activation for the Self vs Other contrast whereas patients showed relatively greater activation in these and additional regions for the Other vs Self contrast. Although patients demonstrated grossly intact neural activity while observing others in pain, they showed more subtle abnormalities when required to toggle between imagining themselves vs others experiencing pain. © The Author (2016). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

[Methodological quality of articles on therapeutic procedures published in Cirugía Española. Evaluation of the period 2005-2008].

PubMed

Manterola, Carlos; Grande, Luís

2010-04-01

To determine methodological quality of therapy articles published in Cirugía Española and to study its association with the publication year, the centre of origin and subjects. A literature study which included all therapy articles published between 2005 and 2008. All kinds of clinical designs were considered, excluding editorials, review articles, letters to editor and experimental studies. Variables analysed included: year of publication, centre of origin, design, and methodological quality of articles. A valid and reliable scale was applied to determine methodological quality. A total of 243 articles [206 series of cases (84.8%), 27 cohort studies (11.1%), 9 clinical trials (3.7%) and 1 case control study (0.4%)] were found. Studies came preferentially from Catalonia and Valencia (22.3% and 12.3% respectively). Thematic areas most frequently found were hepato-bilio-pancreatic and colorectal surgery (20.0% and 16.6%, respectively). Average and median of the methodological quality score calculated for the entire series were 9.5+/-4.3 points and 8 points, respectively. Association between methodological quality and geographical area (p=0.0101), subject area (p=0.0267), and university origin (p=0.0369) was found. A significant increase of methodological quality by publication year was observed (p=0.0004). Methodological quality of therapy articles published in Cirugía Española between 2005 and 2008 is low; but an increase tendency with statistical significance was observed.

Modeling the Lac repressor-operator assembly: The influence of DNA looping on Lac repressor conformation

PubMed Central

Swigon, David; Coleman, Bernard D.; Olson, Wilma K.

2006-01-01

Repression of transcription of the Escherichia coli Lac operon by the Lac repressor (LacR) is accompanied by the simultaneous binding of LacR to two operators and the formation of a DNA loop. A recently developed theory of sequence-dependent DNA elasticity enables one to relate the fine structure of the LacR–DNA complex to a wide range of heretofore-unconnected experimental observations. Here, that theory is used to calculate the configuration and free energy of the DNA loop as a function of its length and base-pair sequence, its linking number, and the end conditions imposed by the LacR tetramer. The tetramer can assume two types of conformations. Whereas a rigid V-shaped structure is observed in the crystal, EM images show extended forms in which two dimer subunits are flexibly joined. Upon comparing our computed loop configurations with published experimental observations of permanganate sensitivities, DNase I cutting patterns, and loop stabilities, we conclude that linear DNA segments of short-to-medium chain length (50–180 bp) give rise to loops with the extended form of LacR and that loops formed within negatively supercoiled plasmids induce the V-shaped structure. PMID:16785444

Folding similarity of the outer pore region in prokaryotic and eukaryotic sodium channels revealed by docking of conotoxins GIIIA, PIIIA, and KIIIA in a NavAb-based model of Nav1.4

PubMed Central

Korkosh, Viacheslav S.; Zhorov, Boris S.

2014-01-01

Voltage-gated sodium channels are targets for many drugs and toxins. However, the rational design of medically relevant channel modulators is hampered by the lack of x-ray structures of eukaryotic channels. Here, we used a homology model based on the x-ray structure of the NavAb prokaryotic sodium channel together with published experimental data to analyze interactions of the μ-conotoxins GIIIA, PIIIA, and KIIIA with the Nav1.4 eukaryotic channel. Using Monte Carlo energy minimizations and published experimentally defined pairwise contacts as distance constraints, we developed a model in which specific contacts between GIIIA and Nav1.4 were readily reproduced without deformation of the channel or toxin backbones. Computed energies of specific interactions between individual residues of GIIIA and the channel correlated with experimental estimates. The predicted complexes of PIIIA and KIIIA with Nav1.4 are consistent with a large body of experimental data. In particular, a model of Nav1.4 interactions with KIIIA and tetrodotoxin (TTX) indicated that TTX can pass between Nav1.4 and channel-bound KIIIA to reach its binding site at the selectivity filter. Our models also allowed us to explain experimental data that currently lack structural interpretations. For instance, consistent with the incomplete block observed with KIIIA and some GIIIA and PIIIA mutants, our computations predict an uninterrupted pathway for sodium ions between the extracellular space and the selectivity filter if at least one of the four outer carboxylates is not bound to the toxin. We found a good correlation between computational and experimental data on complete and incomplete channel block by native and mutant toxins. Thus, our study suggests similar folding of the outer pore region in eukaryotic and prokaryotic sodium channels. PMID:25156117

Nuclear Magnetic Dipole and Electric Quadrupole Moments: Their Measurement and Tabulation as Accessible Data

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

Stone, N. J., E-mail: n.stone@physics.ox.ac.uk

The most recent tabulations of nuclear magnetic dipole and electric quadrupole moments have been prepared and published by the Nuclear Data Section of the IAEA, Vienna [N. J. Stone, Report No. INDC(NDS)-0650 (2013); Report No. INDC(NDS)-0658 (2014)]. The first of these is a table of recommended quadrupole moments for all isotopes in which all experimental results are made consistent with a limited number of adopted standards for each element; the second is a combined listing of all measurements of both moments. Both tables cover all isotopes and energy levels. In this paper, the considerations relevant to the preparation of bothmore » tables are described, together with observations as to the importance and (where appropriate) application of necessary corrections to achieve the “best” values. Some discussion of experimental methods is included with emphasis on their precision. The aim of the published quadrupole moment table is to provide a standard reference in which the value given for each moment is the best available and for which full provenance is given. A table of recommended magnetic dipole moments is in preparation, with the same objective in view.« less

A systematic review of doctors' experiences and needs to support the care of women with female genital mutilation.

PubMed

Dawson, Angela; Homer, Caroline S E; Turkmani, Sabera; Black, Kirsten; Varol, Nesrin

2015-10-01

Female genital mutilation (FGM) involves partial or complete removal of the external female genitalia or other injury for non-therapeutic reasons. Little is known about the knowledge and skills of doctors who care for affected women and their practice in relation to FGM. To examine the FGM experiences and educational needs of doctors. A structured search of five bibliographic databases was undertaken to identify peer-reviewed research literature published in English between 2004 and 2014 using the keywords "female genital mutilation," "medical," "doctors," "education," and "training." Observational, quasi-experimental, and non-experimental descriptive studies were suitable for inclusion. A narrative synthesis of the study findings was undertaken and themes were identified. Ten papers were included in the review, three of which were from low-income countries. The analysis identified three themes: knowledge and attitudes, FGM-related medical practices, and education and training. There is a need for improved education and training to build knowledge and skills, and to change attitudes concerning the medicalization of FGM and reinfibulation. Copyright © 2015 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.

Peripheral myopization and visual performance with experimental rigid gas permeable and soft contact lens design.

PubMed

Pauné, J; Queiros, A; Quevedo, L; Neves, H; Lopes-Ferreira, D; González-Méijome, J M

2014-12-01

To evaluate the performance of two experimental contact lenses (CL) designed to induce relative peripheral myopic defocus in myopic eyes. Ten right eyes of 10 subjects were fitted with three different CL: a soft experimental lens (ExpSCL), a rigid gas permeable experimental lens (ExpRGP) and a standard RGP lens made of the same material (StdRGP). Central and peripheral refraction was measured using a Grand Seiko open-field autorefractometer across the central 60° of the horizontal visual field. Ocular aberrations were measured with a Hartman-Shack aberrometer, and monocular contrast sensitivity function (CSF) was measured with a VCTS6500 without and with the three contact lenses. Both experimental lenses were able to increase significantly the relative peripheral myopic defocus up to -0.50 D in the nasal field and -1.00 D in the temporal field (p<0.05). The ExpRGP induced a significantly higher myopic defocus in the temporal field compared to the ExpSCL. ExpSCL induced significantly lower levels of Spherical-like HOA than ExpRGP for the 5mm pupil size (p<0.05). Both experimental lenses kept CSF within normal limits without any statistically significant change from baseline (p>0.05). RGP lens design seems to be more effective to induce a significant myopic change in the relative peripheral refractive error. Both lenses preserve a good visual performance. The worsened optical quality observed in ExpRGP was due to an increased coma-like and spherical-like HOA. However, no impact on the visual quality as measured by CSF was observed. Copyright © 2014 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

A Decade of Literacy Research in the "Journal of Experimental Education."

ERIC Educational Resources Information Center

Knudson, Ruth E.; Theurer, Joan Leikam; Onofrey, Karen A.

This study examined various trends that exist among the 246 refereed articles published in the "Journal of Experimental Education" between 1990 and 1999. The study's results showed that 39 (16%) of the Journal articles published during this 9-year span focused on literacy. Information was categorized for each article with respect to authors'…

Theories of blood coagulation.

PubMed

Riddel, James P; Aouizerat, Bradley E; Miaskowski, Christine; Lillicrap, David P

2007-01-01

Although the concept of the coagulation cascade represented a significant advance in the understanding of coagulation and served for many years as a useful model, more recent clinical and experimental observations demonstrate that the cascade/waterfall hypothesis does not fully and completely reflect the events of hemostasis in vivo. The goal of this article is to review the evolution of the theories of coagulation and their proposed models to serve as a tool when reviewing the research and practice literature that was published in the context of these different theories over time.

Incongruence Between Observers’ and Observed Facial Muscle Activation Reduces Recognition of Emotional Facial Expressions From Video Stimuli

PubMed Central

Wingenbach, Tanja S. H.; Brosnan, Mark; Pfaltz, Monique C.; Plichta, Michael M.; Ashwin, Chris

2018-01-01

According to embodied cognition accounts, viewing others’ facial emotion can elicit the respective emotion representation in observers which entails simulations of sensory, motor, and contextual experiences. In line with that, published research found viewing others’ facial emotion to elicit automatic matched facial muscle activation, which was further found to facilitate emotion recognition. Perhaps making congruent facial muscle activity explicit produces an even greater recognition advantage. If there is conflicting sensory information, i.e., incongruent facial muscle activity, this might impede recognition. The effects of actively manipulating facial muscle activity on facial emotion recognition from videos were investigated across three experimental conditions: (a) explicit imitation of viewed facial emotional expressions (stimulus-congruent condition), (b) pen-holding with the lips (stimulus-incongruent condition), and (c) passive viewing (control condition). It was hypothesised that (1) experimental condition (a) and (b) result in greater facial muscle activity than (c), (2) experimental condition (a) increases emotion recognition accuracy from others’ faces compared to (c), (3) experimental condition (b) lowers recognition accuracy for expressions with a salient facial feature in the lower, but not the upper face area, compared to (c). Participants (42 males, 42 females) underwent a facial emotion recognition experiment (ADFES-BIV) while electromyography (EMG) was recorded from five facial muscle sites. The experimental conditions’ order was counter-balanced. Pen-holding caused stimulus-incongruent facial muscle activity for expressions with facial feature saliency in the lower face region, which reduced recognition of lower face region emotions. Explicit imitation caused stimulus-congruent facial muscle activity without modulating recognition. Methodological implications are discussed. PMID:29928240

A strain-mediated corrosion model for bioabsorbable metallic stents.

PubMed

Galvin, E; O'Brien, D; Cummins, C; Mac Donald, B J; Lally, C

2017-06-01

This paper presents a strain-mediated phenomenological corrosion model, based on the discrete finite element modelling method which was developed for use with the ANSYS Implicit finite element code. The corrosion model was calibrated from experimental data and used to simulate the corrosion performance of a WE43 magnesium alloy stent. The model was found to be capable of predicting the experimentally observed plastic strain-mediated mass loss profile. The non-linear plastic strain model, extrapolated from the experimental data, was also found to adequately capture the corrosion-induced reduction in the radial stiffness of the stent over time. The model developed will help direct future design efforts towards the minimisation of plastic strain during device manufacture, deployment and in-service, in order to reduce corrosion rates and prolong the mechanical integrity of magnesium devices. The need for corrosion models that explore the interaction of strain with corrosion damage has been recognised as one of the current challenges in degradable material modelling (Gastaldi et al., 2011). A finite element based plastic strain-mediated phenomenological corrosion model was developed in this work and was calibrated based on the results of the corrosion experiments. It was found to be capable of predicting the experimentally observed plastic strain-mediated mass loss profile and the corrosion-induced reduction in the radial stiffness of the stent over time. To the author's knowledge, the results presented here represent the first experimental calibration of a plastic strain-mediated corrosion model of a corroding magnesium stent. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Measuring and Modeling Organochlorine Pesticide Response to Activated Carbon Amendment in Tidal Sediment Mesocosms.

PubMed

Thompson, Jay M; Hsieh, Ching-Hong; Hoelen, Thomas P; Weston, Donald P; Luthy, Richard G

2016-05-03

Activated carbon (AC) sediment amendment for hydrophobic organic contaminants (HOCs) is attracting increasing regulatory and industrial interest. However, mechanistic and well-vetted models are needed. Here, we conduct an 18 month field mesocosm trial at a site containing dichlorodiphenyltrichloroethane (DDT) and chlordane. Different AC applications were applied and, for the first time, a recently published mass transfer model was field tested under varying experimental conditions. AC treatment was effective in reducing DDT and chlordane concentration in polyethylene (PE) samplers, and contaminant extractability by Arenicola brasiliensis digestive fluids. A substantial AC particle size effect was observed. For example, chlordane concentration in PE was reduced by 93% 6 months post-treatment in the powdered AC (PAC) mesocosm, compared with 71% in the granular AC (GAC) mesocosm. Extractability of sediment-associated DDT and chlordane by A. brasiliensis digestive fluids was reduced by at least a factor of 10 in all AC treatments. The model reproduced the relative effects of varying experimental conditions (particle size, dose, mixing time) on concentrations in polyethylene passive samplers well, in most cases within 25% of experimental observations. Although uncertainties such as the effect of long-term AC fouling by organic matter remain, the study findings support the use of the model to assess long-term implications of AC amendment.

Experimentally, How Dark Are Black Hole Mergers?

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

Annis, James; Soares-Santos, Marcelle

2016-09-29

The first Advanced LIGO observing run detected two black hole merger events with confidence and likely a third. Many groups organized to followup the events in the optical even though the strong theoretical prior that no optical emission should be seen. We carry through the logic of this by asking about the experimental upper limits to the optical light from Advanced LIGO black hole mergere events. We inventory the published optical searches for transient events associated with the black hole mergers. We describe the factors that go into a formal limit on the visibility of an event (sky area coverage,more » the coverage factor of the camera, the fraction of sky not covered by intervening objects), and list what is known from the literature of the followup teams quantitative assessment of each factor. Where possible we calculate the total probability from each group that the source was imaged. The calculation of confidence level is reviewed for the case of no background. We find that an experimental 95% upper limit on the magnitude of a black hole requires the sum of the total probabilities over all events to be more than 3. In the first Advanced LIGO observing run we were far from reaching that threshold.« less

Global assessment of experimental climate warming on tundra vegetation: heterogeneity over space and time.

PubMed

Elmendorf, Sarah C; Henry, Gregory H R; Hollister, Robert D; Björk, Robert G; Bjorkman, Anne D; Callaghan, Terry V; Collier, Laura Siegwart; Cooper, Elisabeth J; Cornelissen, Johannes H C; Day, Thomas A; Fosaa, Anna Maria; Gould, William A; Grétarsdóttir, Járngerður; Harte, John; Hermanutz, Luise; Hik, David S; Hofgaard, Annika; Jarrad, Frith; Jónsdóttir, Ingibjörg Svala; Keuper, Frida; Klanderud, Kari; Klein, Julia A; Koh, Saewan; Kudo, Gaku; Lang, Simone I; Loewen, Val; May, Jeremy L; Mercado, Joel; Michelsen, Anders; Molau, Ulf; Myers-Smith, Isla H; Oberbauer, Steven F; Pieper, Sara; Post, Eric; Rixen, Christian; Robinson, Clare H; Schmidt, Niels Martin; Shaver, Gaius R; Stenström, Anna; Tolvanen, Anne; Totland, Orjan; Troxler, Tiffany; Wahren, Carl-Henrik; Webber, Patrick J; Welker, Jeffery M; Wookey, Philip A

2012-02-01

Understanding the sensitivity of tundra vegetation to climate warming is critical to forecasting future biodiversity and vegetation feedbacks to climate. In situ warming experiments accelerate climate change on a small scale to forecast responses of local plant communities. Limitations of this approach include the apparent site-specificity of results and uncertainty about the power of short-term studies to anticipate longer term change. We address these issues with a synthesis of 61 experimental warming studies, of up to 20 years duration, in tundra sites worldwide. The response of plant groups to warming often differed with ambient summer temperature, soil moisture and experimental duration. Shrubs increased with warming only where ambient temperature was high, whereas graminoids increased primarily in the coldest study sites. Linear increases in effect size over time were frequently observed. There was little indication of saturating or accelerating effects, as would be predicted if negative or positive vegetation feedbacks were common. These results indicate that tundra vegetation exhibits strong regional variation in response to warming, and that in vulnerable regions, cumulative effects of long-term warming on tundra vegetation - and associated ecosystem consequences - have the potential to be much greater than we have observed to date. © 2011 Blackwell Publishing Ltd/CNRS.

An observational examination of the literature in diagnostic anatomic pathology.

PubMed

Foucar, Elliott; Wick, Mark R

2005-05-01

Original research published in the medical literature confronts the reader with three very basic and closely linked questions--are the authors' conclusions true in the contextual setting in which the work was performed (internally valid); if so, are the conclusions also applicable in other practice settings (externally valid); and, if the conclusions of the study are bona fide, do they represent an important contribution to medical practice or are they true-but-insignificant? Most publications attempt to convince readers that the researchers' conclusions are both internally valid and important, and occasionally papers also directly address external validity. Developing standardized methods to facilitate the prospective determination of research importance would be useful to both journals and their readers, but has proven difficult. In contrast, the evidence-based medicine (EBM) movement has had more success with understanding and codifying factors thought to promote research validity. Of the many variables that can influence research validity, research design is the one that has received the most attention. The present paper reviews the contributions of EBM to understanding research validity, looking for areas where EBM's body of knowledge is applicable to the anatomic pathology (AP) literature. As part of this project, the authors performed a pilot observational analysis of a representative sample of the current pertinent literature on diagnostic tissue pathology. The results of that review showed that most of the latter publications employ one of the four categories of "observational" research design that have been delineated by the EBM movement, and that the most common of these observational designs is a "cross-sectional" comparison. Pathologists do not presently use the "experimental" research designs so admired by advocates of EBM. Slightly > 50% of AP observational studies employed statistical evaluations to support their final conclusions. Comparison of the current AP literature with a selected group of papers published in 1977 shows a discernible change over that period that has affected not just technological procedures, but also research design and use of statistics. Although we feel that advocates of EBM deserve credit for bringing attention to the close link between research design and research validity, much of the EBM effort has centered on refining "experimental" methodology, and the complexities of observational research have often been treated in an inappropriately dismissive manner. For advocates of EBM, an observational study is what you are relegated to as a second choice when you are unable to do an experimental study. The latter viewpoint may be true for evaluating new chemotherapeutic agents, but is unacceptable to pathologists, whose research advances are currently completely dependent on well-conducted observational research. Rather than succumb to randomization envy and accept EBM's assertion that observational research is second best, the challenge to AP is to develop and adhere to standards for observational research that will allow our patients to benefit from the full potential of this time tested approach to developing valid insights into disease.

Synonymous Mutations at the Beginning of the Influenza A Virus Hemagglutinin Gene Impact Experimental Fitness.

PubMed

Canale, Aneth S; Venev, Sergey V; Whitfield, Troy W; Caffrey, Daniel R; Marasco, Wayne A; Schiffer, Celia A; Kowalik, Timothy F; Jensen, Jeffrey D; Finberg, Robert W; Zeldovich, Konstantin B; Wang, Jennifer P; Bolon, Daniel N A

2018-04-13

The fitness effects of synonymous mutations can provide insights into biological and evolutionary mechanisms. We analyzed the experimental fitness effects of all single-nucleotide mutations, including synonymous substitutions, at the beginning of the influenza A virus hemagglutinin (HA) gene. Many synonymous substitutions were deleterious both in bulk competition and for individually isolated clones. Investigating protein and RNA levels of a subset of individually expressed HA variants revealed that multiple biochemical properties contribute to the observed experimental fitness effects. Our results indicate that a structural element in the HA segment viral RNA may influence fitness. Examination of naturally evolved sequences in human hosts indicates a preference for the unfolded state of this structural element compared to that found in swine hosts. Our overall results reveal that synonymous mutations may have greater fitness consequences than indicated by simple models of sequence conservation, and we discuss the implications of this finding for commonly used evolutionary tests and analyses. Copyright © 2018. Published by Elsevier Ltd.

Interaction of cinnamic acid derivatives with β-cyclodextrin in water: experimental and molecular modeling studies.

PubMed

Liu, Benguo; Zeng, Jie; Chen, Chen; Liu, Yonglan; Ma, Hanjun; Mo, Haizhen; Liang, Guizhao

2016-03-01

Cyclodextrins (CDs) can be used to improve the solubility and stability of cinnamic acid derivatives (CAs). However, there was no detailed report about understanding the effects of the substituent groups in the benzene ring on the inclusion behavior between CAs and CDs in aqueous solution. Here, the interaction of β-CD with CAs, including caffeic acid, ferulic acid, and p-coumaric acid, in water was investigated by phase-solubility method, UV, fluorescence, and (1)H NMR spectroscopy, together with ONIOM (our Own N-layer Integrated Orbital molecular Mechanics)-based QM/MM (Quantum Mechanics/Molecular Mechanics) calculations. Experimental results demonstrated that CAs could form 1:1 stoichiometric inclusion complex with β-CD by non-covalent bonds, and that the maximum apparent stability constants were found in caffeic acid (176M(-1)) followed by p-coumaric acid (160M(-1)) and ferulic acid (133M(-1)). Moreover, our calculations reasonably illustrated the binding orientations of β-CD with CAs determined by experimental observations. Copyright © 2015. Published by Elsevier Ltd.

A computational model of the respiratory network challenged and optimized by data from optogenetic manipulation of glycinergic neurons.

PubMed

Oku, Yoshitaka; Hülsmann, Swen

2017-04-07

The topology of the respiratory network in the brainstem has been addressed using different computational models, which help to understand the functional properties of the system. We tested a neural mass model by comparing the result of activation and inhibition of inhibitory neurons in silico with recently published results of optogenetic manipulation of glycinergic neurons [Sherman, et al. (2015) Nat Neurosci 18:408]. The comparison revealed that a five-cell type model consisting of three classes of inhibitory neurons [I-DEC, E-AUG, E-DEC (PI)] and two excitatory populations (pre-I/I) and (I-AUG) neurons can be applied to explain experimental observations made by stimulating or inhibiting inhibitory neurons by light sensitive ion channels. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

Spherical subjective refraction with a novel 3D virtual reality based system.

PubMed

Pujol, Jaume; Ondategui-Parra, Juan Carlos; Badiella, Llorenç; Otero, Carles; Vilaseca, Meritxell; Aldaba, Mikel

To conduct a clinical validation of a virtual reality-based experimental system that is able to assess the spherical subjective refraction simplifying the methodology of ocular refraction. For the agreement assessment, spherical refraction measurements were obtained from 104 eyes of 52 subjects using three different methods: subjectively with the experimental prototype (Subj.E) and the classical subjective refraction (Subj.C); and objectively with the WAM-5500 autorefractor (WAM). To evaluate precision (intra- and inter-observer variability) of each refractive tool independently, 26 eyes were measured in four occasions. With regard to agreement, the mean difference (±SD) for the spherical equivalent (M) between the new experimental subjective method (Subj.E) and the classical subjective refraction (Subj.C) was -0.034D (±0.454D). The corresponding 95% Limits of Agreement (LoA) were (-0.856D, 0.924D). In relation to precision, intra-observer mean difference for the M component was 0.034±0.195D for the Subj.C, 0.015±0.177D for the WAM and 0.072±0.197D for the Subj.E. Inter-observer variability showed worse precision values, although still clinically valid (below 0.25D) in all instruments. The spherical equivalent obtained with the new experimental system was precise and in good agreement with the classical subjective routine. The algorithm implemented in this new system and its optical configuration has been shown to be a first valid step for spherical error correction in a semiautomated way. Copyright © 2016 Spanish General Council of Optometry. Published by Elsevier España, S.L.U. All rights reserved.

[Trends in nursing research in Korea: research trends for studies published from the inaugural issue to 2010 in the Journal of Korean Academy of Nursing and the journals published by member societies under Korean Academy of Nursing Science].

PubMed

Choe, Myoung Ae; Kim, Nam Cho; Kim, Kyung Mi; Kim, Sung Jae; Park, Kyung Sook; Byeon, Young Soon; Shin, Sung Rae; Yang, Soo; Lee, Kyung Sook; Lee, Eun Hyun; Lee, In Sook; Lee, Tae Wha; Cho, Myung Ok; Kim, Jin Hak

2014-10-01

The purpose of this study was to identify trends for studies published in the Journal of Korean Academy of Nursing and journals published by member societies from inaugural issues to 2010. A total of 6890 studies were analyzed using descriptive statistics. Quantitative studies accounted for 83.6% while qualitative studies accounted for 14.4%. Most frequently used research designs were quasi-experimental (91.1%) for experimental research and survey (85.2%) for non-experimental research. Most frequent study participants were healthy people (35.8%), most frequent nursing interventions, nursing skills (53.5%), and 39.8% used knowledge, attitude and behavior outcomes for dependent variables. Most frequently used keyword was elderly. Survey studies decreased from 1991 to 2010 by approximately 50%, while qualitative studies increased by about 20%. True experimental research (1.2%) showed no significant changes. Studies focusing on healthy populations increased from 2001-2005 (37.5%) to 2006-2010 (41.0%). From 1970 to 2010, studies using questionnaire accounted for over 50% whereas physiological measurement, approximately 5% only. Experimental studies using nursing skill interventions increased from 1970-1980 (30.4%) to 2006-2010 (64.0%). No significant changes were noted in studies using knowledge, attitude and behavior (39.9%) as dependent variables. The results suggest that further expansion of true experimental, qualitative studies and physiological measurements are needed.

Creep Behavior of Near-Stoichiometric Polycrystalline Binary NiAl

NASA Technical Reports Server (NTRS)

Raj, S. V.

2002-01-01

New and published constant load creep and constant engineering strain rate data on near-stoichiometric binary NiAl in the intermediate temperature range 700 to 1300 K are reviewed. Both normal and inverse primary creep curves are observed depending on stress and temperature. Other characteristics relating to creep of NiAl involving grain size, stress and temperature dependence are critically examined and discussed. At stresses below 25 MPa and temperatures above 1000 K, a new grain boundary sliding mechanism was observed with n approx. 2, Qc approx. 100 kJ/ mol and a grain size exponent of about 2. It is demonstrated that Coble creep and accommodated grain boundary sliding models fail to predict the experimental creep rates by several orders of magnitude.

Direct measurement of neon production rates by (α,n) reactions in minerals

NASA Astrophysics Data System (ADS)

Cox, Stephen E.; Farley, Kenneth A.; Cherniak, Daniele J.

2015-01-01

The production of nucleogenic neon from alpha particle capture by 18O and 19F offers a potential chronometer sensitive to temperatures higher than the more widely used (U-Th)/He chronometer. The accuracy depends on the cross sections and the calculated stopping power for alpha particles in the mineral being studied. Published 18O(α,n)21Ne production rates are in poor agreement and were calculated from contradictory cross sections, and therefore demand experimental verification. Similarly, the stopping powers for alpha particles are calculated from SRIM (Stopping Range of Ions in Matter software) based on a limited experimental dataset. To address these issues we used a particle accelerator to implant alpha particles at precisely known energies into slabs of synthetic quartz (SiO2) and barium tungstate (BaWO4) to measure 21Ne production from capture by 18O. Within experimental uncertainties the observed 21Ne production rates compare favorably to our predictions using published cross sections and stopping powers, indicating that ages calculated using these quantities are accurate at the ∼3% level. In addition, we measured the 22Ne/21Ne ratio and (U-Th)/He and (U-Th)/Ne ages of Durango fluorapatite, which is an important model system for this work because it contains both oxygen and fluorine. Finally, we present 21Ne/4He production rate ratios for a variety of minerals of geochemical interest along with software for calculating neon production rates and (U-Th)/Ne ages.

Developments in the field of allergy in 2009 through the eyes of Clinical and Experimental Allergy

PubMed Central

Chu, H. W.; Lloyd, C. M.; Karmaus, W.; Maestrelli, P.; Mason, P.; Salcedo, G.; Thaikoottathil, J.; Wardlaw, A. J.

2012-01-01

Summary In 2009 the journal published in the region of 200 papers including reviews, editorials, opinion pieces and original papers that ran the full gamut of allergic disease. It is instructive to take stock of this output to determine patterns of interest and where the cutting edge lies. We have surveyed the field of allergic disease as seen through the pages of Clinical and Experimental Allergy (CEA) highlighting trends, emphasizing notable observations and placing discoveries in the context of other key papers published during the year. The review is divided into similar sections as the journal. In the field of Asthma and Rhinitis CEA has contributed significantly to the debate about asthma phenotypes and expressed opinions about the cause of intrinsic asthma. It has also added its halfpennyworth to the hunt for meaningful biomarkers. In Mechanisms the considerable interest in T cell subsets including Th17 and T regulatory cells continues apace and the discipline of Epidemiology continues to invoke a steady stream of papers on risk factors for asthma with investigators still trying to explain the post-second world war epidemic of allergic disease. Experimental Models continue to make important contributions to our understanding of pathogenesis of allergic disease and in the Clinical Allergy section various angles on immunotherapy are explored. New allergens continue to be described in the allergens section to make those allergen chips even more complicated. A rich and vibrant year helpfully summarized by some of our associate editors. PMID:21039970

Polarized light scanning cryomacroscopy, part II: Thermal modeling and analysis of experimental observations.

PubMed

Feig, Justin S G; Solanki, Prem K; Eisenberg, David P; Rabin, Yoed

2016-10-01

This study aims at developing thermal analysis tools and explaining experimental observations made by means of polarized-light cryomacroscopy (Part I). Thermal modeling is based on finite elements analysis (FEA), where two model parameters are extracted from thermal measurements: (i) the overall heat transfer coefficient between the cuvette and the cooling chamber, and (ii) the effective thermal conductivity within the cryoprotective agent (CPA) at the upper part of the cryogenic temperature range. The effective thermal conductivity takes into account enhanced heat transfer due to convection currents within the CPA, creating the so-called Bénard cells. Comparison of experimental results with simulation data indicates that the uncertainty in simulations due to the propagation of uncertainty in measured physical properties exceeds the uncertainty in experimental measurements, which validates the modeling approach. It is shown in this study that while a cavity may form in the upper-center portion of the vitrified CPA, it has very little effect on estimating the temperature distribution within the domain. This cavity is driven by thermal contraction of the CPA, with the upper-center of the domain transitioning to glass last. Finally, it is demonstrated in this study that additional stresses may develop within the glass transition temperature range due to nonlinear behavior of the thermal expansion coefficient. This effect is reported here for the first time in the context of cryobiology, using the capabilities of polarized-light cryomacroscopy. Copyright © 2016. Published by Elsevier Inc.

Experimental illumination of natural habitat--an experimental set-up to assess the direct and indirect ecological consequences of artificial light of different spectral composition.

PubMed

Spoelstra, Kamiel; van Grunsven, Roy H A; Donners, Maurice; Gienapp, Phillip; Huigens, Martinus E; Slaterus, Roy; Berendse, Frank; Visser, Marcel E; Veenendaal, Elmar

2015-05-05

Artificial night-time illumination of natural habitats has increased dramatically over the past few decades. Generally, studies that assess the impact of artificial light on various species in the wild make use of existing illumination and are therefore correlative. Moreover, studies mostly focus on short-term consequences at the individual level, rather than long-term consequences at the population and community level-thereby ignoring possible unknown cascading effects in ecosystems. The recent change to LED lighting has opened up the exciting possibility to use light with a custom spectral composition, thereby potentially reducing the negative impact of artificial light. We describe here a large-scale, ecosystem-wide study where we experimentally illuminate forest-edge habitat with different spectral composition, replicated eight times. Monitoring of species is being performed according to rigid protocols, in part using a citizen-science-based approach, and automated where possible. Simultaneously, we specifically look at alterations in behaviour, such as changes in activity, and daily and seasonal timing. In our set-up, we have so far observed that experimental lights facilitate foraging activity of pipistrelle bats, suppress activity of wood mice and have effects on birds at the community level, which vary with spectral composition. Thus far, we have not observed effects on moth populations, but these and many other effects may surface only after a longer period of time. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Experimental results on the enhanced backscatter phenomenon and its dynamics

NASA Astrophysics Data System (ADS)

Wu, Chensheng; Nelson, William; Ko, Jonathan; Davis, Christopher C.

2014-10-01

Enhanced backscatter effects have long been predicted theoretically and experimentally demonstrated. The reciprocity of a turbulent channel generates a group of paired rays with identical trajectory and phase information that leads to a region in phase space with double intensity and scintillation index. Though simulation work based on phase screen models has demonstrated the existence of the phenomenon, few experimental results have been published describing its characteristics, and possible applications of the enhanced backscatter phenomenon are still unclear. With the development of commercially available high powered lasers and advanced cameras with high frame rates, we have successfully captured the enhanced backscatter effects from different reflection surfaces. In addition to static observations, we have also tilted and pre-distorted the transmitted beam at various frequencies to track the dynamic properties of the enhanced backscatter phenomenon to verify its possible application in guidance and beam and image correction through atmospheric turbulence. In this paper, experimental results will be described, and discussions on the principle and applications of the phenomenon will be included. Enhanced backscatter effects are best observed in certain levels of turbulence (Cn 2≍10-13 m-2/3), and show significant potential for providing self-guidance in beam correction that doesn't introduce additional costs (unlike providing a beacon laser). Possible applications of this phenomenon include tracking fast moving object with lasers, long distance (>1km) alignment, and focusing a high-power corrected laser beam over long distances.

Folding cooperativity in a three-stranded beta-sheet model.

PubMed

Roe, Daniel R; Hornak, Viktor; Simmerling, Carlos

2005-09-16

The thermodynamic behavior of a previously designed three-stranded beta-sheet was studied via several microseconds of standard and replica exchange molecular dynamics simulations. The system is shown to populate at least four thermodynamic minima, including two partially folded states in which only a single hairpin is formed. Simulated melting curves show different profiles for the C and N-terminal hairpins, consistent with differences in secondary structure content in published NMR and CD/FTIR measurements, which probed different regions of the chain. Individual beta-hairpins that comprise the three-stranded beta-sheet are observed to form cooperatively. Partial folding cooperativity between the component hairpins is observed, and good agreement between calculated and experimental values quantifying this cooperativity is obtained when similar analysis techniques are used. However, the structural detail in the ensemble of conformations sampled in the simulations permits a more direct analysis of this cooperativity than has been performed on the basis of experimental data. The results indicate the actual folding cooperativity perpendicular to strand direction is significantly larger than the lower bound obtained previously.

Folding cooperativity in a 3-stranded β-sheet model

PubMed Central

Roe, Daniel R.; Hornak, Viktor

2015-01-01

Summary The thermodynamic behavior of a previously designed three-stranded β-sheet was studied via several µs of standard and replica exchange molecular dynamics simulations. The system is shown to populate at least four thermodynamic minima, including 2 partially folded states in which only a single hairpin is formed. Simulated melting curves show different profiles for the C and N-terminal hairpins, consistent with differences in secondary structure content in published NMR and CD/FTIR measurements, which probed different regions of the chain. Individual β-hairpins that comprise the 3-stranded β-sheet are observed to form cooperatively. Partial folding cooperativity between the component hairpins is observed, and good agreement between calculated and experimental values quantifying this cooperativity is obtained when similar analysis techniques are used. However, the structural detail in the ensemble of conformations sampled in the simulations permits a more direct analysis of this cooperatively than has been performed based on experimental data. The results indicate the actual folding cooperativity perpendicular to strand direction is significantly larger than the lower bound obtained previously. PMID:16095612

Oxidation Mechanisms of Toluene and Benzene

NASA Technical Reports Server (NTRS)

Bittker, David A.

1995-01-01

An expanded and improved version of a previously published benzene oxidation mechanism is presented and shown to model published experimental data fairly successfully. This benzene submodel is coupled to a modified version of a toluene oxidation submodel from the recent literature. This complete mechanism is shown to successfully model published experimental toluene oxidation data for a highly mixed flow reactor and for higher temperature ignition delay times in a shock tube. A comprehensive sensitivity analysis showing the most important reactions is presented for both the benzene and toluene reacting systems. The NASA Lewis toluene mechanism's modeling capability is found to be equivalent to that of the previously published mechanism which contains a somewhat different benzene submodel.

Early mechanical stimulation only permits timely bone healing in sheep.

PubMed

Tufekci, Pelin; Tavakoli, Aramesh; Dlaska, Constantin; Neumann, Mirjam; Shanker, Mihir; Saifzadeh, Siamak; Steck, Roland; Schuetz, Michael; Epari, Devakar

2018-06-01

Bone fracture healing is sensitive to the fixation stability. However, it is unclear which phases of healing are mechano-sensitive and if mechanical stimulation is required throughout repair. In this study, a novel bone defect model, which isolates an experimental fracture from functional loading, was applied in sheep to investigate if stimulation limited to the early proliferative phase is sufficient for bone healing. An active fixator controlled motion in the fracture. Animals of the control group were unstimulated. In the physiological-like group, 1 mm axial compressive movements were applied between day 5 and 21, thereafter the movements were decreased in weekly increments and stopped after 6 weeks. In the early stimulatory group, the movements were stopped after 3 weeks. The experimental fractures were evaluated with mechanical and micro-computed tomography methods after 9 weeks healing. The callus strength of the stimulated fractures (physiological-like and early stimulatory) was greater than the unstimulated control group. The control group was characterized by minimal external callus formation and a lack of bone bridging at 9 weeks. In contrast, the stimulated groups exhibited advanced healing with solid bone formation across the defect. This was confirmed quantitatively by a lower bone volume in the control group compared to the stimulated groups.The novel experimental model permits the application of a well-defined load history to an experimental bone fracture. The poor healing observed in the control group is consistent with under-stimulation. This study has shown early mechanical stimulation only is sufficient for a timely healing outcome. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1790-1796, 2018. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Progression of Ebola Therapeutics During the 2014-2015 Outbreak.

PubMed

Mendoza, Emelissa J; Qiu, Xiangguo; Kobinger, Gary P

2016-02-01

The recent Ebola virus (EBOV) outbreak in West Africa was the deadliest EBOV epidemic in history, highlighting the need for a safe and efficacious treatment against EBOV disease (EVD). In the absence of an approved treatment, experimental drugs were utilized under compassionate grounds hoping to diminish EVD-associated morbidity and mortality. As more data were collected from safety studies, Phase II/III clinical trials were introduced in Guinea, Sierra Leone, and Liberia to test promising candidates, including small-molecule drugs, RNA-based treatments, and antibody-based therapies. In this review, we summarize the use of, and preliminary observations from, current clinical trials with EVD therapeutics, shedding light on experimental drug selection, emergency clinical evaluation, and the impact these factors may have on future infectious disease outbreaks. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

Revisiting the flocculation kinetics of destabilized asphaltenes.

PubMed

Vilas Bôas Fávero, Cláudio; Maqbool, Tabish; Hoepfner, Michael; Haji-Akbari, Nasim; Fogler, H Scott

2017-06-01

A comprehensive review of the recently published work on asphaltene destabilization and flocculation kinetics is presented. Four different experimental techniques were used to study asphaltenes undergoing flocculation process in crude oils and model oils. The asphaltenes were destabilized by different n-alkanes and a geometric population balance with the Smoluchowski collision kernel was used to model the asphaltene aggregation process. Additionally, by postulating a relation between the aggregation collision efficiency and the solubility parameter of asphaltenes and the solution, a unified model of asphaltene aggregation model was developed. When the aggregation model is applied to the experimental data obtained from several different crude oil and model oils, the detection time curves collapsed onto a universal single line, indicating that the model successfully captures the underlying physics of the observed process. Copyright © 2016 Elsevier B.V. All rights reserved.

Transcriptome-wide investigation of genomic imprinting in chicken

PubMed Central

Frésard, Laure; Leroux, Sophie; Servin, Bertrand; Gourichon, David; Dehais, Patrice; Cristobal, Magali San; Marsaud, Nathalie; Vignoles, Florence; Bed'hom, Bertrand; Coville, Jean-Luc; Hormozdiari, Farhad; Beaumont, Catherine; Zerjal, Tatiana; Vignal, Alain; Morisson, Mireille; Lagarrigue, Sandrine; Pitel, Frédérique

2014-01-01

Genomic imprinting is an epigenetic mechanism by which alleles of some specific genes are expressed in a parent-of-origin manner. It has been observed in mammals and marsupials, but not in birds. Until now, only a few genes orthologous to mammalian imprinted ones have been analyzed in chicken and did not demonstrate any evidence of imprinting in this species. However, several published observations such as imprinted-like QTL in poultry or reciprocal effects keep the question open. Our main objective was thus to screen the entire chicken genome for parental-allele-specific differential expression on whole embryonic transcriptomes, using high-throughput sequencing. To identify the parental origin of each observed haplotype, two chicken experimental populations were used, as inbred and as genetically distant as possible. Two families were produced from two reciprocal crosses. Transcripts from 20 embryos were sequenced using NGS technology, producing ∼200 Gb of sequences. This allowed the detection of 79 potentially imprinted SNPs, through an analysis method that we validated by detecting imprinting from mouse data already published. However, out of 23 candidates tested by pyrosequencing, none could be confirmed. These results come together, without a priori, with previous statements and phylogenetic considerations assessing the absence of genomic imprinting in chicken. PMID:24452801

Endogenous Pain Modulation Induced by Extrinsic and Intrinsic Psychological Threat in Healthy Individuals.

PubMed

Gibson, William; Moss, Penny; Cheng, Tak Ho; Garnier, Alexandre; Wright, Anthony; Wand, Benedict M

2018-03-01

Many factors interact to influence threat perception and the subsequent experience of pain. This study investigated the effect of observing pain (extrinsic threat) and intrinsic threat of pain to oneself on pressure pain threshold (PPT). Forty socially connected pairs of healthy volunteers were threat-primed and randomly allocated to experimental or control roles. An experimental pain modulation paradigm was applied, with non-nociceptive threat cues used as conditioning stimuli. In substudy 1, the extrinsic threat to the experimental participant was observation of the control partner in pain. The control participant underwent hand immersion in noxious and non-noxious water baths in randomized order. Change in the observing participant's PPT from baseline to mid- and postimmersion was calculated. A significant interaction was found for PPT between conditions and test time (F 2,78  = 24.9, P < .005). PPT increased by 23.6% ± 19.3% between baseline and during hand immersion (F 1,39  = 43.7, P < .005). Substudy 2 investigated threat of imminent pain to self. After a 15-minute break, the experimental participant's PPT was retested ("baseline 2"). Threat was primed by suggestion of whole arm immersion in an icier, larger water bath. PPT was tested immediately before anticipated arm immersion, after which the experiment ended. A significant increase in PPT between "baseline 2" and "pre-immersion" was seen (t = -7.6, P = .005), a pain modulatory effect of 25.8 ± 20.7%. Extrinsic and intrinsic threat of pain, in the absence of any afferent input therefore influences pain modulation. This may need to be considered in studies that use noxious afferent input with populations who show dysfunctional pain modulation. The effect on endogenous analgesia of observing another's pain and of threat of pain to oneself was investigated. Extrinsic as well as intrinsic threat cues, in the absence of any afferent input, increased pain thresholds, suggesting that mere threat of pain may initiate analgesic effects in traditional noxious experimental paradigms. Copyright © 2017 The American Pain Society. Published by Elsevier Inc. All rights reserved.

[Diversity and frequency of scientific research design and statistical methods in the "Arquivos Brasileiros de Oftalmologia": a systematic review of the "Arquivos Brasileiros de Oftalmologia"--1993-2002].

PubMed

Crosta, Fernando; Nishiwaki-Dantas, Maria Cristina; Silvino, Wilmar; Dantas, Paulo Elias Correa

2005-01-01

To verify the frequency of study design, applied statistical analysis and approval by institutional review offices (Ethics Committee) of articles published in the "Arquivos Brasileiros de Oftalmologia" during a 10-year interval, with later comparative and critical analysis by some of the main international journals in the field of Ophthalmology. Systematic review without metanalysis was performed. Scientific papers published in the "Arquivos Brasileiros de Oftalmologia" between January 1993 and December 2002 were reviewed by two independent reviewers and classified according to the applied study design, statistical analysis and approval by the institutional review offices. To categorize those variables, a descriptive statistical analysis was used. After applying inclusion and exclusion criteria, 584 articles for evaluation of statistical analysis and, 725 articles for evaluation of study design were reviewed. Contingency table (23.10%) was the most frequently applied statistical method, followed by non-parametric tests (18.19%), Student's t test (12.65%), central tendency measures (10.60%) and analysis of variance (9.81%). Of 584 reviewed articles, 291 (49.82%) presented no statistical analysis. Observational case series (26.48%) was the most frequently used type of study design, followed by interventional case series (18.48%), observational case description (13.37%), non-random clinical study (8.96%) and experimental study (8.55%). We found a higher frequency of observational clinical studies, lack of statistical analysis in almost half of the published papers. Increase in studies with approval by institutional review Ethics Committee was noted since it became mandatory in 1996.

Neovascular growth in an experimental alkali corneal burn model.

PubMed

Figueroa-Ortiz, L C; Martín Rodríguez, O; García-Ben, A; García-Campos, J

2014-08-01

To analyse the length and area of corneal surface occupied by vessels, and their location in an experimental model of alkali burn-induced corneal neovascularization. An injury to the central cornea of the right eye in 91 Sprague-Dawley rats was induced using a silver nitrate pencil. The rats were divided in 7 groups that were sacrificed 2, 4, 6, 8, 10, 12 and 14 days post-injury, and then perfused with a mixture of Chinese ink in PBS -phosphate buffer saline-. Corneas were flat-mounted processed and divided in 4 quadrants. Corneal neovascular growth parameters (length and area) and the location of these vessels were performed blind. The results were statistically analysed. Neovascular growth was observed from day 2, reaching its maximum peak in length and area on the 12th day post-injury. A slight reduction in corneal neovascularization was observed after this day. The vessels were initially located in the middle third of the stroma and tended to be observed in the anterior third during the course of the experiment. Neovascularisation was observed on day 2 post-injury in all sectors of corneal surface. Neovascular growth was uniform during the experiment. Neovessels were located in the middle and anterior third of the cornea. Copyright © 2012 Sociedad Española de Oftalmología. Published by Elsevier Espana. All rights reserved.

Gaseous Sulfate Solubility in Glass: Experimental Method

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

Bliss, Mary

2013-11-30

Sulfate solubility in glass is a key parameter in many commercial glasses and nuclear waste glasses. This report summarizes key publications specific to sulfate solubility experimental methods and the underlying physical chemistry calculations. The published methods and experimental data are used to verify the calculations in this report and are expanded to a range of current technical interest. The calculations and experimental methods described in this report will guide several experiments on sulfate solubility and saturation for the Hanford Waste Treatment Plant Enhanced Waste Glass Models effort. There are several tables of sulfate gas equilibrium values at high temperature tomore » guide experimental gas mixing and to achieve desired SO3 levels. This report also describes the necessary equipment and best practices to perform sulfate saturation experiments for molten glasses. Results and findings will be published when experimental work is finished and this report is validated from the data obtained.« less

DIANA-TarBase v7.0: indexing more than half a million experimentally supported miRNA:mRNA interactions.

PubMed

Vlachos, Ioannis S; Paraskevopoulou, Maria D; Karagkouni, Dimitra; Georgakilas, Georgios; Vergoulis, Thanasis; Kanellos, Ilias; Anastasopoulos, Ioannis-Laertis; Maniou, Sofia; Karathanou, Konstantina; Kalfakakou, Despina; Fevgas, Athanasios; Dalamagas, Theodore; Hatzigeorgiou, Artemis G

2015-01-01

microRNAs (miRNAs) are short non-coding RNA species, which act as potent gene expression regulators. Accurate identification of miRNA targets is crucial to understanding their function. Currently, hundreds of thousands of miRNA:gene interactions have been experimentally identified. However, this wealth of information is fragmented and hidden in thousands of manuscripts and raw next-generation sequencing data sets. DIANA-TarBase was initially released in 2006 and it was the first database aiming to catalog published experimentally validated miRNA:gene interactions. DIANA-TarBase v7.0 (http://www.microrna.gr/tarbase) aims to provide for the first time hundreds of thousands of high-quality manually curated experimentally validated miRNA:gene interactions, enhanced with detailed meta-data. DIANA-TarBase v7.0 enables users to easily identify positive or negative experimental results, the utilized experimental methodology, experimental conditions including cell/tissue type and treatment. The new interface provides also advanced information ranging from the binding site location, as identified experimentally as well as in silico, to the primer sequences used for cloning experiments. More than half a million miRNA:gene interactions have been curated from published experiments on 356 different cell types from 24 species, corresponding to 9- to 250-fold more entries than any other relevant database. DIANA-TarBase v7.0 is freely available. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

A counterfactual impact evaluation of a bilingual program on students' grade point average at a spanish university.

PubMed

Arco-Tirado, J L; Fernández-Martín, F; Ramos-García, A M; Littvay, L; Villoria, J; Naranjo, J A

2018-06-01

This observational study intends to estimate the causal effects of an English as a Medium of Instruction (EMI) program (as predictor) on students Grade Point Average (GPA) (as outcome) at a particular University in Spain by using a Counterfactual Impact Evaluation (CIE). The need to address the crucial question of causal inferences in EMI programs to produce credible evidences of successful interventions contrasts, however, with the absence of experimental or quasi-experimental research and evaluation designs in the field. CIE approach is emerging as a methodologically viable solution to bridge that gap. The program evaluated here consisted in delivering an EMI program in a Primary Education Teacher Training Degree group. After achieving balance on the observed covariates and recreating a situation that would have been expected in a randomized experiment, three matching approaches such as genetic matching, nearest neighbor matching and Coarsened Exact Matching were used to analyze observational data from a total of 1288 undergraduate students, including both treatment and control group. Results show unfavorable effects of the bilingual group treatment condition. Potential interpretations and recommendations are provided in order to strengthen future causal evidences of bilingual education programs' effectiveness in Higher Education. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Interfacial charge transfer absorption: Application to metal molecule assemblies

NASA Astrophysics Data System (ADS)

Creutz, Carol; Brunschwig, Bruce S.; Sutin, Norman

2006-05-01

Optically induced charge transfer between adsorbed molecules and a metal electrode was predicted by Hush to lead to new electronic absorption features, but has been only rarely observed experimentally. Interfacial charge transfer absorption (IFCTA) provides information concerning the barriers to charge transfer between molecules and the metal/semiconductor and the magnitude of the electronic coupling and could thus provide a powerful tool for understanding interfacial charge-transfer kinetics. Here, we utilize a previously published model [C. Creutz, B.S. Brunschwig, N. Sutin, J. Phys. Chem. B 109 (2005) 10251] to predict IFCTA spectra of metal-molecule assemblies and compare the literature observations to these predictions. We conclude that, in general, the electronic coupling between molecular adsorbates and the metal levels is so small that IFCTA is not detectable. However, few experiments designed to detect IFCTA have been done. We suggest approaches to optimizing the conditions for observing the process.

Effects of self-esteem improvement program on self-esteem and peer attachment in elementary school children with observed problematic behaviors.

PubMed

Park, Kyung Min; Park, Heeok

2015-03-01

The purpose of this study was to investigate the effects of a self-esteem improvement program on self-esteem and peer attachment in elementary school children with observed problematic behaviors. This study is a quasi-experimental study with a nonequivalent control group pretest-post-test design. A total of 47 fourth grade elementary school students participated in this study. The program was provided for 45 minutes once a week; a total of 12 sessions were completed with a group in the classroom for the experimental group. Child Problem-Behavior Screening Questionnaire was used to measure problematic behavior. Self-esteem was measured using the Rosenberg's Self-esteem Questionnaire, and peer attachment was measured using the Inventory of Parent and Attachment. Measuring was performed right after the program was done (post 1) and 1 month after the program was finished (post 2). To compare the differences in self-esteem and peer attachment between groups, repeated measures analysis of variance was used. Most participants in the experimental group were 10 years old (62.5%, range 10-11), male (52.0%) and with middle grade point average (64.0%). The self-esteem scores in the experimental group were significantly higher than those of the control group (F = 26.64, p < .001). The peer attachment scores in the experimental group were significantly higher than those of the control group (F = 6.48, p = .014). The self-esteem improvement program in this study improved the self-esteem and peer attachment in elementary school children. The self-esteem program helped acknowledge the peer's name and increased their connections. The program needs to be considered as a formal and consistent program. Copyright © 2015. Published by Elsevier B.V.

Numerical simulation of fluid flow and heat transfer in enhanced copper tube

NASA Astrophysics Data System (ADS)

Rahman, M. M.; Zhen, T.; Kadir, A. K.

2013-06-01

Inner grooved tube is enhanced with grooves by increasing the inner surface area. Due to its high efficiency of heat transfer, it is used widely in power generation, air conditioning and many other applications. Heat exchanger is one of the example that uses inner grooved tube to enhance rate heat transfer. Precision in production of inner grooved copper tube is very important because it affects the tube's performance due to various tube parameters. Therefore, it is necessary to carry out analysis in optimizing tube performance prior to production in order to avoid unnecessary loss. The analysis can be carried out either through experimentation or numerical simulation. However, experimental study is too costly and takes longer time in gathering necessary information. Therefore, numerical simulation is conducted instead of experimental research. Firstly, the model of inner grooved tube was generated using SOLIDWORKS. Then it was imported into GAMBIT for healing, followed by meshing, boundary types and zones settings. Next, simulation was done in FLUENT where all the boundary conditions are set. The simulation results were observed and compared with published experimental results. It showed that heat transfer enhancement in range of 649.66% to 917.22% of inner grooved tube compared to plain tube.

How does light-intensity physical activity associate with adult cardiometabolic health and mortality? Systematic review with meta-analysis of experimental and observational studies.

PubMed

Chastin, Sebastien F M; De Craemer, Marieke; De Cocker, Katrien; Powell, Lauren; Van Cauwenberg, Jelle; Dall, Philippa; Hamer, Mark; Stamatakis, Emmanuel

2018-04-25

To assess the relationship between time spent in light physical activity and cardiometabolic health and mortality in adults. Systematic review and meta-analysis. Searches in Medline, Embase, PsycInfo, CINAHL and three rounds of hand searches. Experimental (including acute mechanistic studies and physical activity intervention programme) and observational studies (excluding case and case-control studies) conducted in adults (aged ≥18 years) published in English before February 2018 and reporting on the relationship between light physical activity (<3 metabolic equivalents) and cardiometabolic health outcomes or all-cause mortality. Study quality appraisal with QUALSYST tool and random effects inverse variance meta-analysis. Seventy-two studies were eligible including 27 experimental studies (and 45 observational studies). Mechanistic experimental studies showed that short but frequent bouts of light-intensity activity throughout the day reduced postprandial glucose (-17.5%; 95% CI -26.2 to -8.7) and insulin (-25.1%; 95% CI -31.8 to -18.3) levels compared with continuous sitting, but there was very limited evidence for it affecting other cardiometabolic markers. Three light physical activity programme intervention studies (n ranging from 12 to 58) reduced adiposity, improved blood pressure and lipidaemia; the programmes consisted of activity of >150 min/week for at least 12 weeks. Six out of eight prospective observational studies that were entered in the meta-analysis reported that more time spent in daily light activity reduced risk of all-cause mortality (pooled HR 0.71; 95% CI 0.62 to 0.83). Light-intensity physical activity could play a role in improving adult cardiometabolic health and reducing mortality risk. Frequent short bouts of light activity improve glycaemic control. Nevertheless, the modest volume of the prospective epidemiological evidence base and the moderate consistency between observational and laboratory evidence inhibits definitive conclusions. © 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.

50 CFR 648.12 - Experimental fishing.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 50 Wildlife and Fisheries 10 2011-10-01 2011-10-01 false Experimental fishing. 648.12 Section 648... Experimental fishing. Link to an amendment published at 76 FR 60649, Sept. 29, 2011. The Regional Administrator... part for the conduct of experimental fishing beneficial to the management of the resources or fishery...

The potential role of subclinical Bordetella Pertussis colonization in the etiology of multiple sclerosis.

PubMed

Rubin, Keith; Glazer, Steven

2016-04-01

It is established that (1) subclinical Bordetella pertussis colonization of the nasopharynx persists in highly vaccinated populations, and (2) B. pertussis toxin is a potent adjuvant that, when co-administered with neural antigens, induces neuropathology in experimental autoimmune encephalomyelitis, the principle animal model of multiple sclerosis. Building on these observations with supporting epidemiologic and biologic evidence, we propose that, contrary to conventional wisdom that subclinical pertussis infections are innocuous to hosts, B. pertussis colonization is an important cause of multiple sclerosis. Copyright © 2015 The Authors. Published by Elsevier GmbH.. All rights reserved.

Discovery of a meta-stable Al–Sm phase with unknown stoichiometry using a genetic algorithm

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

Zhang, Feng; McBrearty, Ian; Ott, R T

Unknown crystalline phases observed during the devitrification process of glassy metal alloys significantly limit our ability to understand and control phase selection in these systems driven far from equilibrium. Here, we report a new meta-stable Al5Sm phase identified by simultaneously searching Al-rich compositions of the Al-Sm system, using an efficient genetic algorithm. The excellent match between calculated and experimental X-ray diffraction patterns confirms that this new phase appeared in the crystallization of melt-spun Al90Sm10 alloys. Published by Elsevier Ltd. on behalf of Acta Materialia Inc.

Effects of environmental change on plant species density: Comparing predictions with experiments

USGS Publications Warehouse

Gough, L.; Grace, J.B.

1999-01-01

Ideally, general ecological relationships may be used to predict responses of natural communities to environmental change, but few attempts have been made to determine the reliability of predictions based on descriptive data. Using a previously published structural equation model (SEM) of descriptive data from a coastal marsh landscape, we compared these predictions against observed changes in plant species density resulting from field experiments (manipulations of soil fertility, flooding, salinity, and mammalian herbivory) in two areas within the same marsh. In general, observed experimental responses were fairly consistent with predictions. The largest discrepancy occurred when sods were transplanted from high- to low-salinity sites and herbivores selectively consumed a particularly palatable plant species in the transplanted sods. Individual plot responses to some treatments were predicted more accurately than others. Individual fertilized plot responses were not consistent with predictions (P > 0.05), nor were fenced plots (herbivore exclosures; R2 = 0.15) compared to unfenced plots (R2 = 0.53). For the remaining treatments, predictions reasonably matched responses (R2 = 0.63). We constructed an SEM for the experimental data; it explained 60% of the variance in species density and showed that fencing and fertilization led to decreases in species density that were not predicted from treatment effects on community biomass or observed disturbance levels. These treatments may have affected the ratio of live to dead biomass, and competitive exclusion likely decreased species density in fenced and fertilized plots. We conclude that experimental validation is required to determine the predictive value of comparative relationships derived from descriptive data.

Kinetics of diffusional droplet growth in a liquid/liquid two-phase system

NASA Technical Reports Server (NTRS)

Glickman, M. E.; Fradkov, V. E.

1995-01-01

A new powerful experimental technique based on holographic observations, developed at the NASA Marshall Space Flight Center, now permits observation of small liquid droplets coarsening. This technique was developed and used for mixed-dimensional coarsening studies. Experiments were conducted on an isopycnic two-phase alloy of succinonitrile and water, annealed isothermally over a four-month period. The succinonitrile-rich droplets precipitate from a water-rich liquid matrix having a density very close to that of the droplets. The matrix and droplets, however, have different optical indices. The results of these experiments, along with the results of computer simulation based on the quasi-static diffusion approximation developed at Rensselaer are reported. These results were published recently. Copies of these papers are attached to this report.

Recalculation of the infrared continuum spectrum of the lowest energy triplet transitions in K2

NASA Astrophysics Data System (ADS)

Ligare, Martin; Edmonds, J. Brent

1991-09-01

The observation and identification of the spectra arising from transitions between the lowest energy triplet electronic states of diatomic potassium molecules were made by Huennekens et al. [J. Chem. Phys. 80, 4794 (1984)]. In this letter we recalculate theoretical spectra for these transitions using quasistatic line broadening theory and the recently published ab initio potential energy curves of Jeung and Ross [J. Phys. B 21, 1473 (1988)]. The calculated satellite of the 3Σ+g-3Σ+u transition occurs at 1.105 μm while the satellite is experimentally observed at 1.096 μm. This improved agreement both solidifies the original identification of Huennekens et al. and indicates the accuracy of the recent potential energy curves of Jeung and Ross for the low energy triplet states.

Dynamical effects in x-ray absorption spectra of graphene and monolayered h -BN on Ni(111)

NASA Astrophysics Data System (ADS)

Rusz, J.; Preobrajenski, A. B.; Ng, May Ling; Vinogradov, N. A.; Mårtensson, N.; Wessely, O.; Sanyal, B.; Eriksson, O.

2010-02-01

We present first-principles calculations of x-ray absorption spectra of graphene and hexagonal BN monolayer on the Ni(111) substrate. Including dynamical core-hole screening effects according to the theory of Mahan-Nozières-de Dominics (MND) results in an overall good agreement with previously published experimental data and our new observations. This approach provides a unified first-principles description of the electronic structure and core excitations in the sp2 -bonded materials on metal surfaces and a better insight into the dynamics of screening effects. We demonstrate in particular that the observed spectral features of graphene and hexagonal BN can be well reproduced with the MND theory, and that they are determined by a delicate balance between initial and final-state effects.

Structural identifiability analyses of candidate models for in vitro Pitavastatin hepatic uptake.

PubMed

Grandjean, Thomas R B; Chappell, Michael J; Yates, James W T; Evans, Neil D

2014-05-01

In this paper a review of the application of four different techniques (a version of the similarity transformation approach for autonomous uncontrolled systems, a non-differential input/output observable normal form approach, the characteristic set differential algebra and a recent algebraic input/output relationship approach) to determine the structural identifiability of certain in vitro nonlinear pharmacokinetic models is provided. The Organic Anion Transporting Polypeptide (OATP) substrate, Pitavastatin, is used as a probe on freshly isolated animal and human hepatocytes. Candidate pharmacokinetic non-linear compartmental models have been derived to characterise the uptake process of Pitavastatin. As a prerequisite to parameter estimation, structural identifiability analyses are performed to establish that all unknown parameters can be identified from the experimental observations available. Copyright © 2013. Published by Elsevier Ireland Ltd.

Effect of wound infiltration with ropivacaine or bupivacaine analgesia in breast cancer surgery: A meta-analysis of randomized controlled trials.

PubMed

Tam, Ka-Wai; Chen, Shin-Yan; Huang, Tsai-Wei; Lin, Chao-Chun; Su, Chih-Ming; Li, Ching-Li; Ho, Yuan-Soon; Wang, Wan-Yu; Wu, Chih-Hsiung

2015-10-01

Although not completely painless, breast-conserving surgery is considerably less painful than modified radical mastectomy. Local anesthetics are speculated to reduce postoperative pain when placed at the surgical site. Thus, we conducted a systematic review of randomized controlled trials to evaluate the efficacy of bupivacaine or ropivacaine analgesia for pain relief in breast cancer surgery. PubMed, Embase, the Cochrane Library, Scopus, and the ClinicalTrials.gov registry were searched for studies published up to July 2015. Individual effect sizes were standardized, and a meta-analysis was performed to calculate a pooled effect size by using random effects models. Pain was assessed using a visual analog scale at 1, 2, 12, and 24 h postoperatively. The secondary outcomes included complications and analgesic consumption. We reviewed 13 trials with 1150 patients. We found no difference in postoperative pain reduction at 1, 12, and 24 h after breast cancer surgery between the experimental and control groups. The severity of pain was significantly reduced in the experimental group (weighted mean difference -0.19; 95% confidence interval: -0.39-0.00) at 2 h postoperatively. Moreover, postoperative analgesic consumption did not differ significantly between the groups. No major drug-related complication was observed in any study. Administration of the local anesthetics bupivacaine or ropivacaine during breast cancer surgery decreased pain significantly at only 2 h but did not reduce pain at 12, and 24 h postoperatively. Copyright © 2015 IJS Publishing Group Limited. Published by Elsevier Ltd. All rights reserved.

In situ Biofilm Quantification in Bioelectrochemical Systems by using Optical Coherence Tomography.

PubMed

Molenaar, Sam D; Sleutels, Tom; Pereira, Joao; Iorio, Matteo; Borsje, Casper; Zamudio, Julian A; Fabregat-Santiago, Francisco; Buisman, Cees J N; Ter Heijne, Annemiek

2018-04-25

Detailed studies of microbial growth in bioelectrochemical systems (BESs) are required for their suitable design and operation. Here, we report the use of optical coherence tomography (OCT) as a tool for in situ and noninvasive quantification of biofilm growth on electrodes (bioanodes). An experimental platform is designed and described in which transparent electrodes are used to allow real-time, 3D biofilm imaging. The accuracy and precision of the developed method is assessed by relating the OCT results to well-established standards for biofilm quantification (chemical oxygen demand (COD) and total N content) and show high correspondence to these standards. Biofilm thickness observed by OCT ranged between 3 and 90 μm for experimental durations ranging from 1 to 24 days. This translated to growth yields between 38 and 42 mgCODbiomass  gCODacetate -1 at an anode potential of -0.35 V versus Ag/AgCl. Time-lapse observations of an experimental run performed in duplicate show high reproducibility in obtained microbial growth yield by the developed method. As such, we identify OCT as a powerful tool for conducting in-depth characterizations of microbial growth dynamics in BESs. Additionally, the presented platform allows concomitant application of this method with various optical and electrochemical techniques. © 2018 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

Statins and Thyroid Carcinoma: a Meta-Analysis.

PubMed

Zhao, Junyu; Xu, Chunmei; Yao, Jinming; Yu, Changzhen; Liao, Lin; Dong, Jianjun

2018-06-19

Experimental studies have reported the antineoplastic effects of statins in thyroid carcinoma; however, observational studies suggested that statins might increase the risk of thyroid carcinoma. Therefore, this study evaluated the antineoplastic effects of statins in both in vitro studies and animal models, as well as the epidemiological evidence. Databases-PubMed, Cochrane Library, SinoMed, CNKI, Wanfang, and clinical trial registries- were searched. A meta-analysis was performed with sufficiently homogeneous studies. Eighteen articles were involved. In in vitro studies, statins showed a concentration-dependent inhibition of cell line growth (weighted mean difference -34.68, 95% confidence interval -36.53 to -32.83). A significant efficacy of statin-induced apoptosis was observed (weighted mean difference [95% confidence interval]: 24 h, 57.50 [55.98-59.03]; 48 h, 23.43 [22.19-24.66]; 72 h, 51.29 [47.52-55.07]). Early apoptosis was increased in a dose- and time-dependent manner. In in vivo antitumor studies, lovastatin inhibited tumor growth, as shown by a reduction in tumor volume. However, two clinical studies showed discordant results from the experimental studies. Experimental studies revealed the antineoplastic efficacy of statins but statins were associated with thyroid carcinoma in clinical studies. This discrepancy may be due to the different concentrations of statins used and the effects of hyperlipidemia interventions, and thus further study is required. © 2018 The Author(s). Published by S. Karger AG, Basel.

Silica and lung cancer: a controversial issue.

PubMed

Pairon, J C; Brochard, P; Jaurand, M C; Bignon, J

1991-06-01

The role of crystalline silica in lung cancer has long been the subject of controversy. In this article, we review the main experimental and epidemiological studies dealing with this problem. Some evidence for a genotoxic potential of crystalline silica has been obtained in the rare in vitro studies published to date. In vivo studies have shown that crystalline silica is carcinogenic in the rat; the tumour types appear to vary according to the route of administration. In addition, an association between carcinogenic and fibrogenic potency has been observed in various animal species exposed to crystalline silica. An excess of lung cancer related to occupational exposure to crystalline silica is reported in many epidemiological studies, regardless of the presence of silicosis. However, most of these studies are difficult to interpret because they do not correctly take into account associated carcinogens such as tobacco smoke and other occupational carcinogens. An excess of lung cancer is generally reported in studies based on silicosis registers. Overall, experimental and human studies suggest an association between exposure to crystalline silica and an excess of pulmonary malignancies. Although the data available are not sufficient to establish a clear-cut causal relationship in humans, an association between the onset of pneumoconiosis and pulmonary malignancies is probable. In contrast, experimental observations have given rise to a pathophysiological mechanism that might account for a putative carcinogenic potency of crystalline silica.

Preapproval and postapproval availability of published comparative efficacy research on biological agents.

PubMed

Thomas, Rachel Hutchins; Freeman, Maisha Kelly; Hughes, Peter J

2013-07-15

Preapproval and postapproval availability of published comparative efficacy studies on biological agents approved between 2000 and 2010 was investigated. Approval packages published on the Food and Drug Administration (FDA) website were examined for all biological agents approved between 2000 and 2010 to determine if comparative efficacy studies were available at the time of FDA approval. The availability of comparative efficacy studies published subsequent to approval was determined by searching PubMed for randomized, active-controlled experimental or observational study designs that measured efficacy as the primary endpoint and were relevant to the original FDA-approved indication. From 2000 to 2010, 107 biological agents were approved by FDA. Of the biological agents with alternative treatments, 54.6% had comparative efficacy data available at the time of approval. Although standard-reviewed biological agents were more likely to have comparative efficacy trials included in the FDA approval packages than priority-reviewed biological agents, statistically significant differences are unlikely. Subsequent to approval, 58.1% of biological agents had at least one published comparative efficacy trial, representing a 3.5% absolute increase in the availability of comparative efficacy studies since the time of approval. Vaccines and biological agents in the hematologic diseases, oncology, and miscellaneous diseases classes had fewer published postapproval comparative efficacy studies per agent compared with the overall group of biological agents. Nearly half of all biological agents approved for marketing between 2000 and 2010 lacked publicly accessible, active-controlled efficacy studies at the time of drug approval; a slightly greater proportion of biological agents had comparative efficacy data published subsequent to their approval.

Predicting the process of extinction in experimental microcosms and accounting for interspecific interactions in single-species time series.

PubMed

Ferguson, Jake M; Ponciano, José M

2014-02-01

Predicting population extinction risk is a fundamental application of ecological theory to the practice of conservation biology. Here, we compared the prediction performance of a wide array of stochastic, population dynamics models against direct observations of the extinction process from an extensive experimental data set. By varying a series of biological and statistical assumptions in the proposed models, we were able to identify the assumptions that affected predictions about population extinction. We also show how certain autocorrelation structures can emerge due to interspecific interactions, and that accounting for the stochastic effect of these interactions can improve predictions of the extinction process. We conclude that it is possible to account for the stochastic effects of community interactions on extinction when using single-species time series. © 2013 The Authors. Ecology Letters published by John Wiley & Sons Ltd and CNRS.

Ensemble models of proteins and protein domains based on distance distribution restraints.

PubMed

Jeschke, Gunnar

2016-04-01

Conformational ensembles of intrinsically disordered peptide chains are not fully determined by experimental observations. Uncertainty due to lack of experimental restraints and due to intrinsic disorder can be distinguished if distance distributions restraints are available. Such restraints can be obtained from pulsed dipolar electron paramagnetic resonance (EPR) spectroscopy applied to pairs of spin labels. Here, we introduce a Monte Carlo approach for generating conformational ensembles that are consistent with a set of distance distribution restraints, backbone dihedral angle statistics in known protein structures, and optionally, secondary structure propensities or membrane immersion depths. The approach is tested with simulated restraints for a terminal and an internal loop and for a protein with 69 residues by using sets of sparse restraints for underlying well-defined conformations and for published ensembles of a premolten globule-like and a coil-like intrinsically disordered protein. © 2016 Wiley Periodicals, Inc.

Associating Changes in the Immune System with Clinical Diseases for Interpretation in Risk Assessment

PubMed Central

Germolec, Dori R.; Luebke, Robert W.; Johnson, Victor J.

2016-01-01

This overview is an update of the unit originally published in 2004. While the basic tenants of immunotoxicity have not changed in the past 10 years, several publications have explored the application of immunotoxicological data to the risk assessment process. Therefore, the goal of this unit is still to highlight relationships between xenobiotic-induced immunosuppression and risk of clinical diseases progression. In immunotoxicology, this may require development of models to equate moderate changes in markers of immune functions to potential changes in incidence or severity of infectious diseases. For most xenobiotics, exposure levels and disease incidence data are rarely available and safe exposure levels must be estimated based on observations from experimental models or human biomarker studies. Thus, it is important to establish a scientifically sound framework that allows accurate and quantitative interpretation of experimental or biomarker data in the risk assessment process. PMID:26828330

Bistable behavior of the lac operon in E. coli when induced with a mixture of lactose and TMG.

PubMed

Díaz-Hernández, Orlando; Santillán, Moisés

2010-01-01

In this work we investigate multistability in the lac operon of Escherichia coli when it is induced by a mixture of lactose and the non-metabolizable thiomethyl galactoside (TMG). In accordance with previously published experimental results and computer simulations, our simulations predict that: (1) when the system is induced by TMG, the system shows a discernible bistable behavior while, (2) when the system is induced by lactose, bistability does not disappear but excessively high concentrations of lactose would be required to observe it. Finally, our simulation results predict that when a mixture of lactose and TMG is used, the bistability region in the extracellular glucose concentration vs. extracellular lactose concentration parameter space changes in such a way that the model predictions regarding bistability could be tested experimentally. These experiments could help to solve a recent controversy regarding the existence of bistability in the lac operon under natural conditions.

Microkinetic Modeling of Benzyl Alcohol Oxidation on Carbon-Supported Palladium Nanoparticles

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

Savara, Aditya; Rossetti, Ilenia; Chan-Thaw, Carine E.

Six products are formed from benzyl alcohol oxidation over Pd nanoparticles using O2 as the oxidant: benzaldehyde, toluene, benzyl ether, benzene, benzoic acid, and benzyl benzoate. Three experimental parameters were varied here: alcohol concentration, oxygen concentration, and temperature. Microkinetic modeling using a mechanism published recently with surface intermediates was able to produce all 18 trends observed experimentally with mostly quantitative agreement. Approximate analytical equations derived from the microkinetic model for isothermal conditions reproduced the isothermal trends and provided insight. The most important activation energies are Ea2=57.9 kJ mol₋1, Ea5=129 kJ mol₋1, and Ea6=175 kJ mol₋1, which correspond to alcohol dissociation,more » alkyl hydrogenation, and the reaction of alkyl species with alkoxy species. Upper limits for other activation energies were identified. The concepts of a sticking coefficient and steric factor in solution were applied.« less

Proton, muon and ¹³C hyperfine coupling constants of C₆₀X and C₇₀X (X = H, Mu).

PubMed

Brodovitch, Jean-Claude; Addison-Jones, Brenda; Ghandi, Khashayar; McKenzie, Iain; Percival, Paul W

2015-01-21

The reaction of H atoms with fullerene C70 has been investigated by identifying the radical products formed by addition of the atom muonium (Mu) to the fullerene in solution. Four of the five possible radical isomers of C70Mu were detected by avoided level-crossing resonance (μLCR) spectroscopy, using a dilute solution of enriched (13)C70 in decalin. DFT calculations were used to predict muon and (13)C isotropic hyperfine constants as an aid to assigning the observed μLCR signals. Computational methods were benchmarked against previously published experimental data for (13)C60Mu in solution. Analysis of the μLCR spectrum resulted in the first experimental determination of (13)C hyperfine constants in either C70Mu or C70H. The large number of values confirms predictions that the four radical isomers have extended distributions of unpaired electron spin.

Associating Changes in the Immune System with Clinical Diseases for Interpretation in Risk Assessment.

PubMed

DeWitt, Jamie C; Germolec, Dori R; Luebke, Robert W; Johnson, Victor J

2016-02-01

This overview is an update of the unit originally published in 2004. While the basic tenets of immunotoxicity have not changed in the past 10 years, several publications have explored the application of immunotoxicological data to the risk assessment process. Therefore, the goal of this unit is still to highlight relationships between xenobiotic-induced immunosuppression and risk of clinical diseases progression. In immunotoxicology, this may require development of models to equate moderate changes in markers of immune functions to potential changes in incidence or severity of infectious diseases. For most xenobiotics, exposure levels and disease incidence data are rarely available, and safe exposure levels must be estimated based on observations from experimental models or human biomarker studies. Thus, it is important to establish a scientifically sound framework that allows accurate and quantitative interpretation of experimental or biomarker data in the risk assessment process. Copyright © 2016 John Wiley & Sons, Inc.

Microkinetic Modeling of Benzyl Alcohol Oxidation on Carbon-Supported Palladium Nanoparticles

DOE PAGES

Savara, Aditya; Rossetti, Ilenia; Chan-Thaw, Carine E.; ...

2016-07-14

Six products are formed from benzyl alcohol oxidation over Pd nanoparticles using O2 as the oxidant: benzaldehyde, toluene, benzyl ether, benzene, benzoic acid, and benzyl benzoate. Three experimental parameters were varied here: alcohol concentration, oxygen concentration, and temperature. Microkinetic modeling using a mechanism published recently with surface intermediates was able to produce all 18 trends observed experimentally with mostly quantitative agreement. Approximate analytical equations derived from the microkinetic model for isothermal conditions reproduced the isothermal trends and provided insight. The most important activation energies are Ea2=57.9 kJ mol₋1, Ea5=129 kJ mol₋1, and Ea6=175 kJ mol₋1, which correspond to alcohol dissociation,more » alkyl hydrogenation, and the reaction of alkyl species with alkoxy species. Upper limits for other activation energies were identified. The concepts of a sticking coefficient and steric factor in solution were applied.« less

Determining the direction of tooth grinding: an in vitro study.

PubMed

ten Berge, F; te Poel, J; Ranjitkar, S; Kaidonis, J A; Lobbezoo, F; Hughes, T E; Townsend, G C

2012-08-01

The analysis of microwear patterns, including scratch types and widths, has enabled reconstruction of the dietary habits and lifestyles of prehistoric and modern humans. The aim of this in vitro study was to determine whether an assessment of microwear features of experimental scratches placed on enamel, perpendicularly to the direction of grinding, could predict the grinding direction. Experimental scratches were placed using a scalpel blade on standardised wear facets that had been prepared by wearing opposing enamel surfaces in an electromechanical tooth wear machine. These control 'baseline' facets (with unworn experimental scratches) were subjected to 50 wear cycles, so that differential microwear could be observed on the leading and trailing edges of the 'final' facets. In Group 1 (n=28), the 'footprint' microwear patterns corresponding to the known grinding direction of specimens in the tooth wear machine were identified. Then, they were used to predict the direction of tooth grinding blindly in the same sample after a 2-week intermission period. To avoid overfitting the predictive model, its sensitivity was also cross-validated in a new sample (Group 2, n=14). A crescent-shaped characteristic observed in most experimental scratches matched the grinding direction on all occasions. The best predictor of the direction of grinding was a combined assessment of the leading edge microwear pattern and the crescent characteristic (82.1% in Group 1 and 92.9% in Group 2). In conclusion, a simple scratch test can determine the direction of tooth grinding with high reliability, although further improvement in sensitivity is desirable. © 2012 Blackwell Publishing Ltd.

Oral LD50 toxicity modeling and prediction of per- and polyfluorinated chemicals on rat and mouse.

PubMed

Bhhatarai, Barun; Gramatica, Paola

2011-05-01

Quantitative structure-activity relationship (QSAR) analyses were performed using the LD(50) oral toxicity data of per- and polyfluorinated chemicals (PFCs) on rodents: rat and mouse. PFCs are studied under the EU project CADASTER which uses the available experimental data for prediction and prioritization of toxic chemicals for risk assessment by using the in silico tools. The methodology presented here applies chemometrical analysis on the existing experimental data and predicts the toxicity of new compounds. QSAR analyses were performed on the available 58 mouse and 50 rat LD(50) oral data using multiple linear regression (MLR) based on theoretical molecular descriptors selected by genetic algorithm (GA). Training and prediction sets were prepared a priori from available experimental datasets in terms of structure and response. These sets were used to derive statistically robust and predictive (both internally and externally) models. The structural applicability domain (AD) of the models were verified on 376 per- and polyfluorinated chemicals including those in REACH preregistration list. The rat and mouse endpoints were predicted by each model for the studied compounds, and finally 30 compounds, all perfluorinated, were prioritized as most important for experimental toxicity analysis under the project. In addition, cumulative study on compounds within the AD of all four models, including two earlier published models on LC(50) rodent analysis was studied and the cumulative toxicity trend was observed using principal component analysis (PCA). The similarities and the differences observed in terms of descriptors and chemical/mechanistic meaning encoded by descriptors to prioritize the most toxic compounds are highlighted.

Conformational analysis and global warming potentials of 1,1,1,3,3,3-hexafluoro-2-propanol from absorption spectroscopy

NASA Astrophysics Data System (ADS)

Godin, Paul J.; Le Bris, Karine; Strong, Kimberly

2017-12-01

Absorption cross-sections of 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) were derived from Fourier transform infrared spectra recorded from 530 to 3400 cm-1 with a resolution of 0.1 cm-1 over a temperature range of 300-362 K. These results were compared to previously published experimental measurements made at room temperature and to a theoretical spectrum from density functional theory (DFT) calculations. Good agreement is found between the experimentally derived results, DFT calculations, and previously published data. The only temperature dependence observed was in the amplitude of some of the absorption peaks due to the changing ratio of the stable conformations of HFIP. This temperature dependence does not result in a significant trend in integrated band strength as a function of temperature. The average value for integrated band strength is found to be (2.649 ± 0.065)x10-16 cm molecule-1 for HFIP over the spectral range of 595 to 3010 cm-1. Radiative efficiency (RE) and the global warming potential (GWP) for HFIP were also derived. A RE of 0.293 ± 0.059 Wm-2ppbv-1 is derived, which leads to a GWP100 of 188 in the range of 530 to 3000 cm-1. The DFT calculation is linearly adjusted to match the experimental spectrum. Using this adjusted DFT spectrum to expand the range below 530 to 0 cm-1 , increases the RE to 0.317 ± 0.063 Wm-2ppbv-1 and the GWP100 to 203.

A rabbit ventricular action potential model replicating cardiac dynamics at rapid heart rates.

PubMed

Mahajan, Aman; Shiferaw, Yohannes; Sato, Daisuke; Baher, Ali; Olcese, Riccardo; Xie, Lai-Hua; Yang, Ming-Jim; Chen, Peng-Sheng; Restrepo, Juan G; Karma, Alain; Garfinkel, Alan; Qu, Zhilin; Weiss, James N

2008-01-15

Mathematical modeling of the cardiac action potential has proven to be a powerful tool for illuminating various aspects of cardiac function, including cardiac arrhythmias. However, no currently available detailed action potential model accurately reproduces the dynamics of the cardiac action potential and intracellular calcium (Ca(i)) cycling at rapid heart rates relevant to ventricular tachycardia and fibrillation. The aim of this study was to develop such a model. Using an existing rabbit ventricular action potential model, we modified the L-type calcium (Ca) current (I(Ca,L)) and Ca(i) cycling formulations based on new experimental patch-clamp data obtained in isolated rabbit ventricular myocytes, using the perforated patch configuration at 35-37 degrees C. Incorporating a minimal seven-state Markovian model of I(Ca,L) that reproduced Ca- and voltage-dependent kinetics in combination with our previously published dynamic Ca(i) cycling model, the new model replicates experimentally observed action potential duration and Ca(i) transient alternans at rapid heart rates, and accurately reproduces experimental action potential duration restitution curves obtained by either dynamic or S1S2 pacing.

Article processing charges, funding, and open access publishing at Journal of Experimental & Clinical Assisted Reproduction.

PubMed

Sills, Eric Scott; Vincent, Tina Thibault; Palermo, Gianpiero D

2005-01-13

Journal of Experimental & Clinical Assisted Reproduction is an Open Access, online, electronic journal published by BioMed Central with full contents available to the scientific and medical community free of charge to all readers. Authors maintain the copyright to their own work, a policy facilitating dissemination of data to the widest possible audience without requiring permission from the publisher. This Open Access publishing model is subsidized by authors (or their institutions/funding agencies) in the form of a single pound330 article processing charge (APC), due at the time of manuscript acceptance for publication. Payment of the APC is not a condition for formal peer review and does not apply to articles rejected after review. Additionally, this fee is waived for authors whose institutions are BioMed Central members or where genuine financial hardship exists. Considering ordinary publication fees related to page charges and reprints, the APC at Journal of Experimental & Clinical Assisted Reproduction is comparable to costs associated with publishing in some traditional print journals, and is less expensive than many. Implementation of the APC within this Open Access framework is envisioned as a modern research-friendly policy that supports networking among investigators, brings new research into reach rapidly, and empowers authors with greater control over their own scholarly publications.

[Improving the teaching quality by multiple tools and technology in oral histopathology experimental course].

PubMed

Tian, Zhen; Wang, Li-Zhen; Hu, Yu-Hua; Zhang, Chun-Ye; Li, Jiang

2017-04-01

Oral histopathology is a course which needs to be combined with theory and practice closely. Experimental course plays an important role in teaching oral histopathology. Here, we aim to explore a series of effective measures to improve the teaching quality of experimental course and tried to train observation, thinking, analysis and problem solving skills of dental students. We re-edited and updated the experimental textbook "guidelines of experimental course of oral histopathology", and published the reference book for experimental course--"color pocket atlas of oral histopathology: experiment and diadactic teaching". The number of clinicopathological cases for presentation and class discussion was increased, and high-quality teaching slides were added and replaced the poor-quality or worn out slides. We established a variety of teaching methods based on the internet, which provided an environment of self-directed learning for dental students. Instead of simple slice-reading examination, a new evaluation system based on computer was established. The questionnaire survey showed that the students spoke positively on the teaching reform for experimental course. They thought that the reform played a significant role in enriching the teaching content, motivating learning interest and promoting self-study. Compared with traditional examination, computer-based examination showed a great advantage on mastering professional knowledge systematically and comprehensively. The measures adopted in our teaching reform not only effectively improve the teaching quality of experimental course of oral histopathology, but also help the students to have a clear, logical thinking when facing complicated diseases and have the ability to apply theoretical knowledge into clinical practice.

Exercise genomics--a paradigm shift is needed: a commentary.

PubMed

Bouchard, Claude

2015-12-01

The overarching goal of exercise genomics is to illuminate exercise biology and behaviour in order to better understand the preventive and therapeutic values of exercise. An ancillary aim is to understand the role of genomic variation in human physical attributes and sports performance. The aim of this report is to briefly comment on the current status of exercise genetics and genomics and to suggest potential improvements to the research agenda and translational activities. First, the genomic features of interest to the biology of exercise are defined. Then, the limit of the current focus on common variants and their implications for exercise genomics is highlighted. The need for a major paradigm shift in exercise genomics research is discussed with an emphasis on study designs and appropriately powered studies as well as on more mechanistic and functional research. Finally, a summary of current practices in translational activities compared with what best practice demands is introduced. One suggestion is that the research portfolio of exercise genomics be composed of a larger fraction of experimental and mechanistic investigations and a smaller fraction of observational studies. It is also recommended that research should shift to unbiased exploration of the genome using all the power of genomics, epigenomics and transcriptomics in combination with large observational but preferably experimental study designs, including Mendelian randomisation. In all cases, emphasis on replications is of paramount importance. This represents an extraordinary challenge that can only be met with large-scale collaborative and multicentre research programmes. 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/

The effects of an urban renewal project on health and health inequalities: a quasi-experimental study in Barcelona.

PubMed

Mehdipanah, Roshanak; Rodríguez-Sanz, Maica; Malmusi, Davide; Muntaner, Carles; Díez, Elia; Bartoll, Xavier; Borrell, Carme

2014-09-01

In the last decade, the Neighbourhoods Law in Catalonia (Spain) funded municipalities that presented urban renewal projects within disadvantaged neighbourhoods focusing on physical, social and economic improvements. The objective of the study was to evaluate the effects of this law on the health and health inequalities of residents in the intervened neighbourhoods in the city of Barcelona. A quasi-experimental predesign and postdesign was used to compare adult residents in five intervened neighbourhoods with eight non-intervened comparison neighbourhoods with similar socioeconomic characteristics. The Barcelona Health Survey was used for studying self-rated and mental health in pre (2001, 2006) and post (2011) years. Poisson regression models stratified by sex were used to compute prevalence ratios comparing 2011 with 2006, and later stratified by social class, to study health inequalities. The intervened neighbourhoods had a significant decrease in poor self-rated health in both sexes while no significant changes occurred in the comparison group. When stratified by social class, a significant improvement was observed in poor self-rated health in the manual group of the intervened neighbourhoods in both sexes, resulting in a decrease in self-rated health inequalities. Similar results were observed in poor mental health of women, while in men, poor mental health worsens in both neighbourhood groups but mostly in the comparison group. The Neighbourhoods Law had a positive effect on self-rated health and seems to prevent poor mental health increases in both sexes and especially among manual social classes. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Errata and update to ;Experimental cross sections for L-shell X-ray production and ionization by protons;

NASA Astrophysics Data System (ADS)

Miranda, J.; Lapicki, G.

2018-01-01

A compilation of experimental L-shell X-ray production and ionization cross sections induced by proton impact was published recently (Miranda and Lapicki, 2014), collecting 15 439 experimental cross sections. The database covers an energy range from 10 keV to 1 GeV, and targets from 10Ne to 95Am. A correction to several tabulated values that were in error, as well as an update including new data published after 2012 and older references not found previously are given in the present work. The updated data base increased the total number of experimental cross sections by 3.1% to 15 921. A new analysis of the total number of experimental points per year shows that the possible saturation in the cumulative total number of data is increased to 15 950 ± 110 points.

Comparison between theoretical and experimental stresses in circular semimonocoque cylinders with rectangular cutouts

NASA Technical Reports Server (NTRS)

Mccomb, Harvey G , Jr; Low, Emmet F , Jr

1955-01-01

Comparisons are made between a theory for calculating stresses about rectangular cutouts in circular cylinders of semimonocoque construction published in NACA-TN-3200 and previously published NACA experimental data. The comparisons include stresses in the stringers and shear stresses in the center of the shear panels in the neighborhood of the cutout. The theory takes into account the bending flexibility of the rings in the structure, and this factor is found to be important in the calculation of stresses about cutouts. In general, when the ring flexibility is considered, good agreement is exhibited between the calculated and experimental results. (author)

[What is the methodological quality of articles on therapeutic procedures published in Cirugía Española?].

PubMed

Manterola, Carlos; Busquets, Juli; Pascual, Marta; Grande, Luis

2006-02-01

The aim of this study was to determine the methodological quality of articles on therapeutic procedures published in Cirugía Española and to study its association with the publication year, center, and subject-matter. A bibliometric study that included all articles on therapeutic procedures published in Cirugía Española between 2001 and 2004 was performed. All kinds of clinical designs were considered, excluding editorials, review articles, letters to editor, and experimental studies. The variables analyzed were: year of publication, center, design, and methodological quality. Methodological quality was determined by a valid and reliable scale. Descriptive statistics (calculation of means, standard deviation and medians) and analytical statistics (Pearson's chi2, nonparametric, ANOVA and Bonferroni tests) were used. A total of 244 articles were studied (197 case series [81%], 28 cohort studies [12%], 17 clinical trials [7%], 1 cross sectional study and 1 case-control study [0.8%]). The studies were performed mainly in Catalonia and Murcia (22% and 16%, respectively). The most frequent subject areas were soft tissue and hepatobiliopancreatic surgery (23% and 19%, respectively). The mean and median of the methodological quality score calculated for the entire series was 10.2 +/- 3.9 points and 9.5 points, respectively. Methodological quality significantly increased by publication year (p < 0.001). An association between methodological quality and subject area was observed but no association was detected with the center performing the study. The methodological quality of articles on therapeutic procedures published in Cirugía Española between 2001 and 2004 is low. However, a statistically significant trend toward improvement was observed.

On whose shoulders we stand – the pioneering entomological discoveries of Károly Sajó *

PubMed Central

Vig, Károly

2011-01-01

Abstract The excellence of Károly Sajó as a researcher into Hungary’s natural history has been undeservedly neglected. Yet he did lasting work, especially in entomology, and a number of his discoveries and initiatives were before their time. Born in 1851 in Győr, he received his secondary education there and went to Pest University. He taught in a grammar school in 1877–88 before spending seven years as an entomologist at the National Phylloxera Experimental Station, later the Royal Hungarian State Entomological Station. Pensioned off at his own request in 1895, he moved to Őrszentmiklós, where he continued making entomological observations on his own farm and wrote the bulk of his published materials: almost 500 longer or shorter notes, articles and books, mainly on entomological subjects. Sajó was among the first in the world to publish in 1896 a study of how the weather affects living organisms, entitled Living Barometers. His Sleep in Insects, which appeared in the same year, described his discovery, from 1895 observations of the red turnip beetle, Entomoscelis adonidis (Pallas, 1771), of aestivation in insects – in present-day terms diapause. It was a great loss to universal entomology when Sajó ceased publishing about 25 years before his death. His unpublished notes, with his library and correspondence, were destroyed in the World War II. His surviving insect collection is now kept in the Hungarian Natural History Museum, Budapest. PMID:22303108

A meta-analysis of the published literature on the effectiveness of antimicrobial soaps.

PubMed

Montville, Rebecca; Schaffner, Donald W

2011-11-01

The goal of this research was to conduct a systematic quantitative analysis of the existing data in the literature in order to determine if there is a difference between antimicrobial and nonantimicrobial soaps and to identify the methodological factors that might affect this difference. Data on hand washing efficacy and experimental conditions (sample size, wash duration, soap quantity, challenge organism, inoculum size, and neutralization method) from published studies were compiled and transferred to a relational database. A total of 25 publications, containing 374 observations, met the study selection criteria. The majority of the studies included fewer than 15 observations with each treatment and included a direct comparison between nonantimicrobial soap and antimicrobial soap. Although differences in efficacy between antimicrobial and nonantimicrobial soap were small (∼0.5-log CFU reduction difference), antimicrobial soap produced consistently statistically significantly greater reductions. This difference was true for any of the antimicrobial compounds investigated where n was >20 (chlorhexidine gluconate, iodophor, triclosan, or povidone). Average log reductions were statistically significantly greater (∼2 log CFU) when either gram-positive or gram-negative transient organisms were deliberately added to hands compared with experiments done with resident hand flora (∼0.5 log CFU). Our findings support the importance of using a high initial inoculum on the hands, well above the detection limit. The inherent variability in hand washing seen in the published literature underscores the importance of using a sufficiently large sample size to detect differences when they occur.

On whose shoulders we stand - the pioneering entomological discoveries of Károly Sajó.

PubMed

Vig, Károly

2011-01-01

The excellence of Károly Sajó as a researcher into Hungary's natural history has been undeservedly neglected. Yet he did lasting work, especially in entomology, and a number of his discoveries and initiatives were before their time.Born in 1851 in Győr, he received his secondary education there and went to Pest University. He taught in a grammar school in 1877-88 before spending seven years as an entomologist at the National Phylloxera Experimental Station, later the Royal Hungarian State Entomological Station. Pensioned off at his own request in 1895, he moved to Őrszentmiklós, where he continued making entomological observations on his own farm and wrote the bulk of his published materials: almost 500 longer or shorter notes, articles and books, mainly on entomological subjects.Sajó was among the first in the world to publish in 1896 a study of how the weather affects living organisms, entitled Living Barometers. His Sleep in Insects, which appeared in the same year, described his discovery, from 1895 observations of the red turnip beetle, Entomoscelis adonidis (Pallas, 1771), of aestivation in insects - in present-day terms diapause.It was a great loss to universal entomology when Sajó ceased publishing about 25 years before his death. His unpublished notes, with his library and correspondence, were destroyed in the World War II. His surviving insect collection is now kept in the Hungarian Natural History Museum, Budapest.

Secondary skull fractures in head wounds inflicted by captive bolt guns: autopsy findings and experimental simulation.

PubMed

Perdekamp, Markus Grosse; Kneubuehl, Beat P; Ishikawa, Takaki; Nadjem, Hadi; Kromeier, Jan; Pollak, Stefan; Thierauf, Annette

2010-11-01

Apart from one article published by Rabl and Sigrist in 1992 (Rechtsmedizin 2:156-158), there are no further reports on secondary skull fractures in shots from captive bolt guns. Up to now, the pertinent literature places particular emphasis on the absence of indirect lesions away from the impact point, when dealing with the wounding capacity of slaughterer's guns. The recent observation of two suicidal head injuries accompanied by skull fractures far away from the bolt's path gave occasion to experimental studies using simulants (glycerin soap, balls from gelatin) and skull–brain models. As far as ballistic soap was concerned, the dimensions of the bolt's channel were assessed by multi-slice computed tomography before cutting the blocks open. The test shots to gelatin balls and to skull-brain models were documented by means of a high-speed motion camera. As expected, the typical temporary cavity effect of bullets fired from conventional guns could not be observed when captive bolt stunners were discharged. Nevertheless, the visualized transfer of kinetic energy justifies the assumption that the secondary fractures seen in thin parts of the skull were caused by a hydraulic burst effect.

A study on the protective effect of Cynodon dactylon leaves extract in diabetic rats.

PubMed

Karthik, D; Ravikumar, S

2011-04-01

To investigate the antidiabetic, antioxidant and hypolipidemic efficacy of Cynodon dactylon in diabetic rats. The experimental rats were randomly divided into three groups: Group I: control; Group II: Alloxan diabetic, untreated; and Group III: Alloxan diabetic treated with ethanolic extract of C. dactylon leaves (450 mg/kg·bw). Experimental diabetes was induced by alloxan in a single dose of 150 mg/kg·bw. A Significant diminution of fasting blood sugar level was observed and also significant increase in HDL and decrease (P<0.05) in cholesterol, triglyceride, LDL and VLDL were observed after 15 days of treatment. The investigation also revealed, the activities of AST, ALT, ALP, AP, LDH, and CPK (P<0.05) were decreased in the extract-supplemented group. The significant decrease in protein content and SOD, CAT, GPx, and GSH (P<0.05) activity and increase in LPO in plasma were found to be ameliorated after treatment. Our result supports the fact that administration of extract of C. dactylon leave is able to reduce hyperglycemia and hyperlipidemia risk and also reduced the oxidative stress in diabetic rats. Copyright © 2011 The Editorial Board of Biomedical and Environmental Sciences. Published by Elsevier B.V. All rights reserved.

Numerical and Experimental Study of Mechanisms Involved in Boiling Histotripsy.

PubMed

Pahk, Ki Joo; Gélat, Pierre; Sinden, David; Dhar, Dipok Kumar; Saffari, Nader

2017-12-01

The aim of boiling histotripsy is to mechanically fractionate tissue as an alternative to thermal ablation for therapeutic applications. In general, the shape of a lesion produced by boiling histotripsy is tadpole like, consisting of a head and a tail. Although many studies have demonstrated the efficacy of boiling histotripsy for fractionating solid tumors, the exact mechanisms underpinning this phenomenon are not yet well understood, particularly the interaction of a boiling vapor bubble with incoming incident shockwaves. To investigate the mechanisms involved in boiling histotripsy, a high-speed camera with a passive cavitation detection system was used to observe the dynamics of bubbles produced in optically transparent tissue-mimicking gel phantoms exposed to the field of a 2.0-MHz high-intensity focused ultrasound (HIFU) transducer. We observed that boiling bubbles were generated in a localized heated region and cavitation clouds were subsequently induced ahead of the expanding bubble. This process was repeated with HIFU pulses and eventually resulted in a tadpole-shaped lesion. A simplified numerical model describing the scattering of the incident ultrasound wave by a vapor bubble was developed to help interpret the experimental observations. Together with the numerical results, these observations suggest that the overall size of a lesion induced by boiling histotripsy is dependent on the sizes of (i) the heated region at the HIFU focus and (ii) the backscattered acoustic field by the original vapor bubble. Copyright © 2017 World Federation for Ultrasound in Medicine and Biology. Published by Elsevier Inc. All rights reserved.

Examination of evidence for collinear cluster tri-partition

NASA Astrophysics Data System (ADS)

Pyatkov, Yu. V.; Kamanin, D. V.; Alexandrov, A. A.; Alexandrova, I. A.; Goryainova, Z. I.; Malaza, V.; Mkaza, N.; Kuznetsova, E. A.; Strekalovsky, A. O.; Strekalovsky, O. V.; Zhuchko, V. E.

2017-12-01

Background: In a series of experiments at different time-of-flight spectrometers of heavy ions we have observed manifestations of a new at least ternary decay channel of low excited heavy nuclei. Due to specific features of the effect, it was called collinear cluster tri-partition (CCT). The obtained experimental results have initiated a number of theoretical articles dedicated to different aspects of the CCT. Special attention was paid to kinematics constraints and stability of collinearity. Purpose: To compare theoretical predictions with our experimental data, only partially published so far. To develop the model of one of the most populated CCT modes that gives rise to the so-called "Ni-bump." Method: The fission events under analysis form regular two-dimensional linear structures in the mass correlation distributions of the fission fragments. The structures were revealed both at a highly statistically reliable level but on the background substrate, and at the low statistics in almost noiseless distribution. The structures are bounded by the known magic fragments and were reproduced at different spectrometers. All this provides high reliability of our experimental findings. The model of the CCT proposed here is based on theoretical results, published recently, and the detailed analysis of all available experimental data. Results: Under our model, the CCT mode giving rise to the Ni bump occurs as a two-stage breakup of the initial three body chain like the nuclear configuration with an elongated central cluster. After the first scission at the touching point with one of the side clusters, the predominantly heavier one, the deformation energy of the central cluster allows the emission of up to four neutrons flying apart isotropically. The heavy side cluster and a dinuclear system, consisting of the light side cluster and the central one, relaxed to a less elongated shape, are accelerated in the mutual Coulomb field. The "tip" of the dinuclear system at the moment of its rupture faces the heavy fragment or the opposite direction due to a single turn of the system around its center of gravity. Conclusions: Additional experimental information regarding the energies of the CCT partners and the proposed model of the process respond to criticisms concerning the kinematic constraints and the stability of collinearity in the CCT. The octupole deformed system formed after the first scission is oriented along the fission axis, and its rupture occurs predominantly after the full acceleration. Noncollinear true ternary fission and far asymmetric binary fission, observed earlier, appear to be the special cases of the decay of the prescission configuration leading to the CCT. Detection of the Ni-7268 fission fragments with a kinetic energy E <25 MeV at the mass-separator Lohengrin is proposed for an independent experimental verification of the CCT.

Research Elements: new article types by Elsevier to facilitate reproducibility in science

NASA Astrophysics Data System (ADS)

Zudilova-Seinstra, Elena; van Hensbergen, Kitty; Wacek, Bart

2016-04-01

When researchers start to make plans for new experiments, this is the beginning of a whole cycle of work, including experimental designs, tweaking of existing methods, developing protocols, writing code, collecting and processing experimental data, etc. A large part of this very useful information rarely gets published, which makes experiments difficult to reproduce. The same holds for experimental data, which is not always provided in a reusable format and lacks descriptive information. Furthermore, many types of data, such as a replication data, negative datasets or data from "intermediate experiments" often don't get published because they have no place in a research journal. To address this concern, Elsevier launched a series of peer-reviewed journal titles grouped under the umbrella of Research Elements (https://www.elsevier.com/books-and-journals/research-elements) that allow researchers to publish their data, software, materials and methods and other elements of the research cycle in a brief article format. To facilitate reproducibility, Research Elements have thoroughly thought out submission templates that include all necessary information and metadata as well as peer-review criteria defined per article type. Research Elements can be applicable to multiple research areas; for example, a number of multidisciplinary journals (Data in Brief, SoftwareX, MethodsX) welcome submissions from a large number of subject areas. At other times, these elements are better served within a single field; therefore, a number of domain-specific journals (e.g.: Genomics Data, Chemical Data Collections, Neurocomputing) support the new article formats, too. Upon publication, all Research Elements are assigned with persistent identifiers for direct citation and easy discoverability. Persistent identifiers are also used for interlinking Research Elements and relevant research papers published in traditional journals. Some Research Elements allow post-publication article updates. In the presentation, we will share our experiences and summarize lessons learned during the last two years. We will focus on three types of novel research publications: data articles, software articles and lab resources. We will also present two very recent developments targeting researchers working in Earth and Observational Sciences. And finally, we will illustrate how Research Elements fit in the Research Data Management landscape of a rich variety of services developed at Elsevier to assist researchers in sharing, finding, accessing, linking together and analyzing relevant research data.

Modeling and Measuring the Effects of Radiation Damage Annealing on Helium Diffusion Kinetics in Apatite

NASA Astrophysics Data System (ADS)

Willett, C. D.; Fox, M.; Shuster, D. L.

2016-12-01

Understanding helium diffusion kinetics in apatite is critical for the accurate interpretation of (U-Th)/He thermochronometric data. This problem is complicated by the observation that helium diffusivity is not a simple function of temperature, but may evolve as a function of damage to the apatite crystal lattice resulting from alpha recoil. This `radiation damage' increases as a function of the amount of radiometric parent products, or effective uranium concentration, and time, but decreases due to thermal annealing of damage, necessitating a detailed understanding of radiation damage production and annealing in cases of burial heating over geologic timescales. Published observations [1,2] suggest that annealing rates of damage caused by alpha recoil and fission tracks in apatite differ. Existing models, however, assume the diffusion kinetics resulting from the two sources of damage are identical [3], demonstrating the need for further investigation of these damage sources. We present modeling and experimental work designed to interrogate the effects of radiation damage and its annealing on helium diffusion kinetics in apatite. Using previously published results [4] that investigated the effects of annealing temperature and duration on measured helium diffusivity, we fit a set of functions that are then integrated into a numerical model that tracks the evolution of radiation damage and apparent (U-Th)/He age. We compare the results of this model calibration to existing models [3]. In addition, we present data from two suites of diffusion experiments. The first suite, intended to test the published methodology and results, uses Durango apatite, while the second uses Sierran (CA) granite as a first test to determine if apatite of varying chemistry and age responds differently to the thermal annealing of radiation damage. Ultimately, the updated model and experimental results will benefit the interpretation of the effects of radiation damage accumulation and annealing in apatite and expand the range of geologic settings that can be studied using low-temperature thermochronology. References: [1] Fox, M., Shuster, D. (2014), EPSL 397, 174-183; [2] Gautheron, C. et al. (2013), Chem. Geol. 351, 257-267; [3] Flowers, R. et al. (2009), GCA 73, 2347-2365; [4] Shuster, D., Farley, K. (2009), GCA 73, 6183-6196.

Theory of the Decoherence Effect in Finite and Infinite Open Quantum Systems Using the Algebraic Approach

NASA Astrophysics Data System (ADS)

Blanchard, Philippe; Hellmich, Mario; Ługiewicz, Piotr; Olkiewicz, Robert

Quantum mechanics is the greatest revision of our conception of the character of the physical world since Newton. Consequently, David Hilbert was very interested in quantum mechanics. He and John von Neumann discussed it frequently during von Neumann's residence in Göttingen. He published in 1932 his book Mathematical Foundations of Quantum Mechanics. In Hilbert's opinion it was the first exposition of quantum mechanics in a mathematically rigorous way. The pioneers of quantum mechanics, Heisenberg and Dirac, neither had use for rigorous mathematics nor much interest in it. Conceptually, quantum theory as developed by Bohr and Heisenberg is based on the positivism of Mach as it describes only observable quantities. It first emerged as a result of experimental data in the form of statistical observations of quantum noise, the basic concept of quantum probability.

Publication Trends in The Analysis of Verbal Behavior: 1999-2008

ERIC Educational Resources Information Center

Marcon-Dawson, Allyne; Vicars, Sara M.; Miguel, Caio F.

2009-01-01

"The Analysis of Verbal Behavior" ("TAVB") publishes experimental and theoretical papers relevant to a behavioral analysis of language. Normand, Fossa, and Poling (2000) reviewed the published studies in "TAVB" across several dimensions and found that despite the growth of the journal, most articles published in "TAVB" from 1982 to 1998 were…

The Influence of Scientific Research and Evaluation on Publishing Educational Curriculum

ERIC Educational Resources Information Center

Baughman, Marcy

2008-01-01

Prior to the No Child Left Behind (NCLB) Act, scientific research to support development of curriculum materials or to demonstrate curricular efficacy was not required. NCLB transformed the development and publishing process for K-12 educational materials by prompting publishers to increase funding for experimentally based research on educational…

Single-cell and coupled GRN models of cell patterning in the Arabidopsis thaliana root stem cell niche

PubMed Central

2010-01-01

Background Recent experimental work has uncovered some of the genetic components required to maintain the Arabidopsis thaliana root stem cell niche (SCN) and its structure. Two main pathways are involved. One pathway depends on the genes SHORTROOT and SCARECROW and the other depends on the PLETHORA genes, which have been proposed to constitute the auxin readouts. Recent evidence suggests that a regulatory circuit, composed of WOX5 and CLE40, also contributes to the SCN maintenance. Yet, we still do not understand how the niche is dynamically maintained and patterned or if the uncovered molecular components are sufficient to recover the observed gene expression configurations that characterize the cell types within the root SCN. Mathematical and computational tools have proven useful in understanding the dynamics of cell differentiation. Hence, to further explore root SCN patterning, we integrated available experimental data into dynamic Gene Regulatory Network (GRN) models and addressed if these are sufficient to attain observed gene expression configurations in the root SCN in a robust and autonomous manner. Results We found that an SCN GRN model based only on experimental data did not reproduce the configurations observed within the root SCN. We developed several alternative GRN models that recover these expected stable gene configurations. Such models incorporate a few additional components and interactions in addition to those that have been uncovered. The recovered configurations are stable to perturbations, and the models are able to recover the observed gene expression profiles of almost all the mutants described so far. However, the robustness of the postulated GRNs is not as high as that of other previously studied networks. Conclusions These models are the first published approximations for a dynamic mechanism of the A. thaliana root SCN cellular pattering. Our model is useful to formally show that the data now available are not sufficient to fully reproduce root SCN organization and genetic profiles. We then highlight some experimental holes that remain to be studied and postulate some novel gene interactions. Finally, we suggest the existence of a generic dynamical motif that can be involved in both plant and animal SCN maintenance. PMID:20920363

Computational modelling and analysis of the molecular network regulating sporulation initiation in Bacillus subtilis.

PubMed

Ihekwaba, Adaoha E C; Mura, Ivan; Barker, Gary C

2014-10-24

Bacterial spores are important contaminants in food, and the spore forming bacteria are often implicated in food safety and food quality considerations. Spore formation is a complex developmental process involving the expression of more than 500 genes over the course of 6 to 8 hrs. The process culminates in the formation of resting cells capable of resisting environmental extremes and remaining dormant for long periods of time, germinating when conditions promote further vegetative growth. Experimental observations of sporulation and germination are problematic and time consuming so that reliable models are an invaluable asset in terms of prediction and risk assessment. In this report we develop a model which assists in the interpretation of sporulation dynamics. This paper defines and analyses a mathematical model for the network regulating Bacillus subtilis sporulation initiation, from sensing of sporulation signals down to the activation of the early genes under control of the master regulator Spo0A. Our model summarises and extends other published modelling studies, by allowing the user to execute sporulation initiation in a scenario where Isopropyl β-D-1-thiogalactopyranoside (IPTG) is used as an artificial sporulation initiator as well as in modelling the induction of sporulation in wild-type cells. The analysis of the model results and the comparison with experimental data indicate that the model is good at predicting inducible responses to sporulation signals. However, the model is unable to reproduce experimentally observed accumulation of phosphorelay sporulation proteins in wild type B. subtilis. This model also highlights that the phosphorelay sub-component, which relays the signals detected by the sensor kinases to the master regulator Spo0A, is crucial in determining the response dynamics of the system. We show that there is a complex connectivity between the phosphorelay features and the master regulatory Spo0A. Additional we discovered that the experimentally observed regulation of the phosphotransferase Spo0B for wild-type B. subtilis may be playing an important role in the network which suggests that modelling of sporulation initiation may require additional experimental support.

75 FR 43172 - Maternal, Infant, and Early Childhood Home Visiting Program

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-23

... the evaluation results have been published in a peer-reviewed journal; or (bb) quasi-experimental... design (i.e. randomized controlled trial [RCT] or quasi-experimental design [QED]), level of attrition... a quasi-experimental design as a study design in which sample members are selected for the program...

Characterization of single grain by observing magnetic ejection and rotation in microgravity

NASA Astrophysics Data System (ADS)

Uyeda, Chiaki

A simple and nondestructive method to perform material identification on a single particle is desired in various fields of material science that is concerned with nano-sized particles. We propose a method of identification based on magnetization data, which is obtained from field-induced translation and rotation in microgravity [1]. Material identification is possible from magnetization data because an intrinsic value of susceptibility and anisotropy is assigned to every material according to a data book that compiles the published values [2]. Preliminary ob-servation on free translational motion due to repulsive field-gradient force was reported for mm-sized crystal of corundum [1] and other oxides. Rotational oscillation was observed for various diamagnetic single-crystals in homogeneous field [2]. In order to examine the capability of the above-mentioned material characterization, translation and rotation motion was observed for sub-millimeter-sized quartz, calcite and forsterite in microgravity condition (MGLAB, Japan, duration: 4.5s). It is expected from motional equations that the 2 motions are independent to mass of particles, In a given field distribution, acceleration of translation is expected to be uniquely determined from intrinsic susceptibility of sample. The above properties are exam-ined in the present work by varying experimental parameters. It is noted that observation of the above two motions in microgravity serve as a useful method to detect magnetization of single small particles, be cause the system is free of both sample holder and mass measure-ment. It is expected that magnetization can be measured on a isolated small sample down to nano-level, in condition that motion of the sample is observable. For both susceptibility and anisotropy, range of observed values using microgravity cover the range of compiled published values [2]. Hence material identification is possible for solid material in general. Diamagnetic magnetization and its anisotropy derive from three-dimensional distribution of localized elec-trons. In case of organic materials, origin of magnetization was consistently explained in terms of molecular-orbital method. The investigation was not performed on oxide crystals partly because the experimental values were not reported for most of the material[4]. Improvement of sensitivity using microgravity condition was necessary in order to understand the overall relationship between electron distribution and anisotropy of susceptibility. [1] K. Hisayoshi et al: J.Phys.: Conf. Ser., (2009) 156 012021. [2] R. Guputa: "Landort Bornstein" New Series II (1983) 445. [3]C.Uyeda et al.(206)Jpn.J.appl.Phys.43 L124 [4]C.Uyeda et al.: Appl. Phys. Lett. (1983) 094103.

Summary of past experience in natural laminar flow and experimental program for resilient leading edge

NASA Technical Reports Server (NTRS)

Carmichael, B. H.

1979-01-01

The potential of natural laminar flow for significant drag reduction and improved efficiency for aircraft is assessed. Past experience with natural laminar flow as reported in published and unpublished data and personal observations of various researchers is summarized. Aspects discussed include surface contour, waviness, and smoothness requirements; noise and vibration effects on boundary layer transition, boundary layer stability criteria; flight experience with natural laminar flow and suction stabilized boundary layers; and propeller slipstream, rain, frost, ice and insect contamination effects on boundary layer transition. The resilient leading edge appears to be a very promising method to prevent leading edge insect contamination.

In situ spectroscopic study of the plastic deformation of amorphous silicon under nonhydrostatic conditions induced by indentation

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

Gerbig, Yvonne B.; Michaels, C. A.; Bradby, Jodie E.

Indentation-induced plastic deformation of amorphous silicon (a-Si) thin films was studied by in situ Raman imaging of the deformed contact region of an indented sample, employing a Raman spectroscopy-enhanced instrumented indentation technique (IIT). The occurrence and evolving spatial distribution of changes in the a-Si structure caused by processes, such as polyamorphization and crystallization, induced by indentation loading were observed. Furthermore, the obtained experimental results are linked with previously published work on the plastic deformation of a-Si under hydrostatic compression and shear deformation to establish a model for the deformation behavior of a-Si under indentation loading.

Eccentricity and misalignment effects on the performance of high-pressure annular seals

NASA Technical Reports Server (NTRS)

Chen, W. C.; Jackson, E. D.

1985-01-01

Annular pressure seals act as powerful hydrostatic bearings and influence the dynamic characteristics of rotating machinery. This work, using the existing concentric seal theories, provides a simple approximate method for calculation of both seal leakage and the dynamic coefficients for short seals with large eccentricity and/or misalignment of the shaft. Rotation and surface roughness effects are included for leakage and dynamic force calculation. The leakage calculations for both laminar and turbulent flow are compared with experimental results. The dynamic coefficients are compared with analytical results. Excellent agreement between the present work and published results have been observed up to the eccentricitiy ratio of 0.8.

In situ spectroscopic study of the plastic deformation of amorphous silicon under nonhydrostatic conditions induced by indentation

DOE PAGES

Gerbig, Yvonne B.; Michaels, C. A.; Bradby, Jodie E.; ...

2015-12-17

Indentation-induced plastic deformation of amorphous silicon (a-Si) thin films was studied by in situ Raman imaging of the deformed contact region of an indented sample, employing a Raman spectroscopy-enhanced instrumented indentation technique (IIT). The occurrence and evolving spatial distribution of changes in the a-Si structure caused by processes, such as polyamorphization and crystallization, induced by indentation loading were observed. Furthermore, the obtained experimental results are linked with previously published work on the plastic deformation of a-Si under hydrostatic compression and shear deformation to establish a model for the deformation behavior of a-Si under indentation loading.

Radiation hydrodynamics modeling of the highest compression inertial confinement fusion ignition experiment from the National Ignition Campaign

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

Clark, D. S.; Marinak, M. M.; Weber, C. R.

2015-02-15

The recently completed National Ignition Campaign (NIC) on the National Ignition Facility (NIF) showed significant discrepancies between post-shot simulations of implosion performance and experimentally measured performance, particularly in thermonuclear yield. This discrepancy between simulation and observation persisted despite concerted efforts to include all of the known sources of performance degradation within a reasonable two-dimensional (2-D), and even three-dimensional (3-D), simulation model, e.g., using measured surface imperfections and radiation drives adjusted to reproduce observed implosion trajectories [Clark et al., Phys. Plasmas 20, 056318 (2013)]. Since the completion of the NIC, several effects have been identified that could explain these discrepancies andmore » that were omitted in previous simulations. In particular, there is now clear evidence for larger than anticipated long-wavelength radiation drive asymmetries and a larger than expected perturbation seeded by the capsule support tent. This paper describes an updated suite of one-dimensional (1-D), 2-D, and 3-D simulations that include the current best understanding of these effects identified since the NIC, as applied to a specific NIC shot. The relative importance of each effect on the experimental observables is compared. In combination, these effects reduce the simulated-to-measured yield ratio from 125:1 in 1-D to 1.5:1 in 3-D, as compared to 15:1 in the best 2-D simulations published previously. While the agreement with the experimental data remains imperfect, the comparison to the data is significantly improved and suggests that the largest sources for the previous discrepancies between simulation and experiment are now being included.« less

The combined therapy with chondroitin sulfate plus glucosamine sulfate or chondroitin sulfate plus glucosamine hydrochloride does not improve joint damage in an experimental model of knee osteoarthritis in rabbits.

PubMed

Roman-Blas, Jorge A; Mediero, Aránzazu; Tardío, Lidia; Portal-Nuñez, Sergio; Gratal, Paula; Herrero-Beaumont, Gabriel; Largo, Raquel

2017-01-05

Osteoarthritis is the most common chronic joint disorder especially during aging. Although with controversies, glucosamine, both in its forms of sulfate and hydrochloride, and chondroitin sulfate are commonly employed to treat osteoarthritis. Due to the modest improve in the symptoms observed in patients treated with these drugs alone, a formulation combining both agents has been considered. The discrepant results achieved for pain control or structural improvement in osteoarthritis patients has been attributed to the quality of chemical formulations or different bias in clinical studies. The current study has been designed to test the effects of two different combined formulations with adequate pharmaceutical grade of these drugs in osteoarthritic joints, and to explore the underlying mechanisms modulated by both formulations in different osteoarthritis target tissues. Knee osteoarthritis was surgically induced in experimental rabbits. Some animals received the combined therapy (CT)1, (chondroitin sulfate 1200mg/day + glucosamine sulfate 1500mg/day), or the CT2 ((chondroitin sulfate 1200mg/day + glucosamine hydrochloride 1500mg/day). Neither CT1 nor CT2 significantly modified the cartilage damage or the synovial inflammation observed in osteoarthritic animals. Treatments were also unable to modify the presence of pro-inflammatory mediators, and the synthesis of metalloproteinases in the cartilage or in the synovium of osteoarthritic animals. Combined therapies did not modify the decrease in the subchondral bone mineral density observed in osteoarthritic rabbits. Therapies of chondroitin sulfate plus glucosamine sulfate or chondroitin sulfate plus glucosamine hydrochloride failed to improve structural damage or to ameliorate the inflammatory profile of joint tissues during experimental osteoarthritis. Published by Elsevier B.V.

Plasma proteins in the acquired denture pellicle enhance substrate surface free energy and Candida albicans phospholipase and proteinase activities.

PubMed

Custodio, William; Silva, Wander J; Paes Leme, Adriana F; Cury, Jaime A; Del Bel Cury, Altair A

2015-11-01

The objective of the present study was to determine if blood plasma proteins could change the proteome of the acquired denture pellicle by label-free quantitative proteomics. As pellicle proteome modulates the interaction between substrates and Candida cells, we investigated its effect on the surface free energy (SFE) of the coated resin and on Candida albicans phospholipase and aspartyl proteinase activities. Poly(methylmethacrylate) discs were exposed to saliva (control) or saliva enriched with blood plasma (experimental group). The pellicle proteome was analyzed by mass spectrometry coupled with liquid chromatography. SFE was determined by acid-base technique. After biofilm formation, phospholipase and proteinase activities were determined accordingly to classic plate methods. Data were analyzed by two-way anova and Tukey test (P < 0.05). α-Amylase, cystatins, mucins, and host-immune system proteins were the main proteins identified in the control group. Fibrinogen and albumin were observed only in the experimental group. Coated discs of the experimental group presented an increased SFE (P < 0.05). For both enzymes tested, the experimental group showed higher proteolytic activity (P < 0.001). Blood plasma changes the proteome of the acquired denture pellicle, increasing surface free energy and the activity of Candida albicans phospholipase and aspartyl proteinase. © 2014 Wiley Publishing Asia Pty Ltd.

The effects of awareness and count duration on adult respiratory rate measurements: An experimental study.

PubMed

Hill, Andrew; Kelly, Eliza; Horswill, Mark S; Watson, Marcus O

2018-02-01

To investigate whether awareness of manual respiratory rate monitoring affects respiratory rate in adults, and whether count duration influences respiratory rate estimates. Nursing textbooks typically suggest that the patient should ideally be unaware of respiratory rate observations; however, there is little published evidence of the effect of awareness on respiratory rate, and none specific to manual measurement. In addition, recommendations about the length of the respiratory rate count vary from text to text, and the relevant empirical evidence is scant, inconsistent and subject to substantial methodological limitations. Experimental study with awareness of respiration monitoring (aware, unaware; randomised between-subjects) and count duration (60 s, 30 s, 15 s; within-subjects) as the independent variables. Respiratory rate (breaths/minute) was the dependent variable. Eighty-two adult volunteers were randomly assigned to aware and unaware conditions. In the baseline block, no live monitoring occurred. In the subsequent experimental block, the researcher informed aware participants that their respiratory rate would be counted, and did so. Respirations were captured throughout via video recording, and counted by blind raters viewing 60-, 30- and 15-s extracts. The data were collected in 2015. There was no baseline difference between the groups. During the experimental block, the respiratory rates of participants in the aware condition were an average of 2.13 breaths/minute lower compared to unaware participants. Reducing the count duration from 1 min to 15 s caused respiratory rate to be underestimated by an average of 2.19 breaths/minute (and 0.95 breaths/minute for 30-s counts). The awareness effect did not depend on count duration. Awareness of monitoring appears to reduce respiratory rate, and shorter monitoring durations yield systematically lower respiratory rate estimates. When interpreting and acting upon respiratory rate data, clinicians should consider the potential influence of these factors, including cumulative effects. © 2017 The Authors. Journal of Clinical Nursing Published by John Wiley & Sons Ltd.

Skin hydration analysis by experiment and computer simulations and its implications for diapered skin.

PubMed

Saadatmand, M; Stone, K J; Vega, V N; Felter, S; Ventura, S; Kasting, G; Jaworska, J

2017-11-01

Experimental work on skin hydration is technologically challenging, and mostly limited to observations where environmental conditions are constant. In some cases, like diapered baby skin, such work is practically unfeasible, yet it is important to understand potential effects of diapering on skin condition. To overcome this challenge, in part, we developed a computer simulation model of reversible transient skin hydration effects. Skin hydration model by Li et al. (Chem Eng Sci, 138, 2015, 164) was further developed to simulate transient exposure conditions where relative humidity (RH), wind velocity, air, and skin temperature can be any function of time. Computer simulations of evaporative water loss (EWL) decay after different occlusion times were compared with experimental data to calibrate the model. Next, we used the model to investigate EWL and SC thickness in different diapering scenarios. Key results from the experimental work were: (1) For occlusions by RH=100% and free water longer than 30 minutes the absorbed amount of water is almost the same; (2) Longer occlusion times result in higher water absorption by the SC. The EWL decay and skin water content predictions were in agreement with experimental data. Simulations also revealed that skin under occlusion hydrates mainly because the outflux is blocked, not because it absorbs water from the environment. Further, simulations demonstrated that hydration level is sensitive to time, RH and/or free water on skin. In simulated diapering scenarios, skin maintained hydration content very close to the baseline conditions without a diaper for the entire duration of a 24 hours period. Different diapers/diaper technologies are known to have different profiles in terms of their ability to provide wetness protection, which can result in consumer-noticeable differences in wetness. Simulation results based on published literature using data from a number of different diapers suggest that diapered skin hydrates within ranges considered reversible. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Empirical retrocausality: Testing physics hypotheses with parapsychological experiments

NASA Astrophysics Data System (ADS)

Dobyns, York

2017-05-01

In 2011, Daryl Bem published a report of nine parapsychological experiments showing evidence of retrocausal information transfer. Earlier in 2016, the team of Bem, Tressoldi, Rabeyron, and Duggan published the results of a meta-analysis containing 81 independent replications of the original Bem experiments (total of 90 with the originals).[1] This much larger database continues to show positive results of generally comparable effect size, thus demonstrating that the effects claimed by Bem can be replicated by independent researchers and greatly strengthening the case for empirically observed retrocausation. Earlier (2011) work by this author showed how a modification of one of Bem's original experiments could be used to test the mechanism implicitly proposed by Echeverria, Klinkhammer, and Thorne to explain how retrocausal phenomena can exist without any risk of self-contradictory event sequences (time paradoxes). In light of the new publication and new evidence, the current work generalizes the previous analysis which was restricted to only one of Bem's experimental genres (precognitive approach and avoidance). The current analysis shows how minor modifications can be made in Bem's other experimental genres of retroactive priming, retroactive habituation, and retroactive facilitation of recall to test the EKT anti-paradox mechanism. If the EKT hypothesis is correct, the modified experiments, while continuing to show replicable retrocausal phenomena, will also show a characteristic pattern of distortion in the statistics of the random selections used to drive the experiments.

The role of Th1 and Th17 cells in glomerulonephritis.

PubMed

Azadegan-Dehkordi, Fatemeh; Bagheri, Nader; Shirzad, Hedayatollah; Rafieian-Kopaei, Mahmoud

2015-04-01

T helper (Th) cells as an important part of the immune is responsible for elimination of invading pathogens. But, if Th cell responses are not regulated effectively, the autoimmune diseases might develop. The Th17 subset usually produces interleukin-17A which in experimental models of organ-specific autoimmune inflammation is very important. Directory of open access journals (DOAJ), Google Scholar, Embase, Scopus, PubMed and Web of Science have been searched. Fifty-six articles were found and searched. In the present review article, we tried to summarize the recently published data about characteristics and role of Th1 and Th17 cells and discuss in detail, the potential role of these T helpers immune responses in renal inflammation and renal injury, focusing on glomerulonephritis. Published papers in animal and human studies indicated that autoimmune diseases such as rheumatoid arthritis and multiple sclerosis, classically believed to be Th1-mediated, are mainly derived from a Th17 immune response. Identification of the Th17 subgroup has explained seemingly paradoxical observations and improved our understanding of immune-mediated inflammatory responses. Secretion of IL-17A, as well as IL-17F, IL-21, IL-22, suggests that Th17 subset may play a crucial role as a pleiotropic pro-inflammatory Th subset. There is experimental evidence to support the notion that Th1 and Th17 cells contribute to kidney injury in renal inflammatory diseases like glomerulonephritis.

Perceived effectiveness of text and pictorial health warnings for smokeless tobacco packages in Navi Mumbai, India, and Dhaka, Bangladesh: findings from an experimental study.

PubMed

Mutti, Seema; Reid, Jessica L; Gupta, Prakash C; Pednekar, Mangesh S; Dhumal, Gauri; Nargis, Nigar; Hussain, Akm Ghulam; Hammond, David

2016-07-01

To examine the perceived effectiveness of text and pictorial smokeless tobacco health warnings in India and Bangladesh, including different types of message content. An experimental study was conducted in Navi Mumbai, India (n=1002), and Dhaka, Bangladesh (n=1081). Face-to-face interviews were conducted on tablets with adult (≥19 years) smokeless tobacco users and youth (16-18 years) users and non-users. Respondents viewed warnings depicting five health effects, within one of the four randomly assigned warning label conditions (or message themes): (1) text-only, (2) symbolic pictorial, (3) graphic pictorial or (4) personal testimonial pictorial messages. Text-only warnings were perceived as less effective than all of the pictorial styles (p<0.001 for all). Graphic warnings were given higher effectiveness ratings than symbolic or testimonial warnings (p<0.001). No differences were observed in levels of agreement with negative attitudes and beliefs across message themes, after respondents had viewed warnings. Pictorial warnings are more effective than text-only messages. Pictorial warnings depicting graphic health effects may have the greatest impact, consistent with research from high-income countries on cigarette warnings. 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/

[Modulation of scoliotic spine growth in experimental animals using intelligent metal bars].

PubMed

Sánchez-Márquez, J M; Sánchez Pérez-Grueso, F J; Fernández-Baíllo, N; Gil-Garay, E; Antuña-Antuña, S

2013-01-01

To create an experimental structural scoliosis model in mice to evaluate the efficacy of shape-memory metals to gradually correct the deformity over time. Experimental scoliosis was generated in 3 week-old mice by means of a suture between the left scapula and pelvis for 8 weeks. They were then randomised into two groups: a control group, in which the suture was cut, and another, in those that also had a Nitinol straight memory-wire implant fixed to the column. Serial X-rays were performed to determine the efficacy of the Nitinol in the correction of the scoliosis. In a second time, the histological changes at apical vertical body level and the adjacent discs were evaluated pre- and post-correction. A mean 81.5° kyphoscoliosis was gradually induced. In the control group, after cutting the suture, an initial reduction in the deformity was observed, but later it remained stable throughout the time (54° at two weeks). In the Nitinol group, a gradual reduction was observed in the scoliosis angle value, to a mean of 8.7° at two weeks. The curvature of the apical vertebral body and adjacent discs were partially corrected after two weeks of correcting the deformity. This scoliosis model has demonstrated the efficacy of a straight Nitinol wire fixed to the spinal column in the gradual correction of kyphoscoliosis and in the changes in its adjacent structures. Copyright © 2013 SECOT. Published by Elsevier Espana. All rights reserved.

Nonspherical particles in a pseudo-2D fluidized bed: Experimental study.

PubMed

Mahajan, Vinay V; Padding, Johan T; Nijssen, Tim M J; Buist, Kay A; Kuipers, J A M

2018-05-01

Fluidization is widely used in industries and has been extensively studied, both experimentally and theoretically, in the past. However, most of these studies focus on spherical particles while in practice granules are rarely spherical. Particle shape can have a significant effect on fluidization characteristics. It is therefore important to study the effect of particle shape on fluidization behavior in detail. In this study, experiments in pseudo-2D fluidized beds are used to characterize the fluidization of spherocylindrical (rod-like) Geldart D particles of aspect ratio 4. Pressure drop and optical measurement methods (Digital Image Analysis, Particle Image Velocimetry, Particle Tracking Velocimetry) are employed to measure bed height, particle orientation, particle circulation, stacking, and coordination number. The commonly used correlations to determine the pressure drop across a bed of nonspherical particles are compared to experiments. Experimental observations and measurements have shown that rod-like particles are prone to interlocking and channeling behavior. Well above the minimum fluidization velocity, vigorous bubbling fluidization is observed, with groups of interlocked particles moving upwards, breaking up, being thrown high in the freeboard region and slowly raining down as dispersed phase. At high flowrates, a circulation pattern develops with particles moving up through the center and down at the walls. Particles tend to orient themselves along the flow direction. © 2018 The Authors AIChE Journal published by Wiley Periodicals, Inc. on behalf of American Institute of Chemical Engineers , 64: 1573-1590, 2018.

An integrated physiology model to study regional lung damage effects and the physiologic response

PubMed Central

2014-01-01

Background This work expands upon a previously developed exercise dynamic physiology model (DPM) with the addition of an anatomic pulmonary system in order to quantify the impact of lung damage on oxygen transport and physical performance decrement. Methods A pulmonary model is derived with an anatomic structure based on morphometric measurements, accounting for heterogeneous ventilation and perfusion observed experimentally. The model is incorporated into an existing exercise physiology model; the combined system is validated using human exercise data. Pulmonary damage from blast, blunt trauma, and chemical injury is quantified in the model based on lung fluid infiltration (edema) which reduces oxygen delivery to the blood. The pulmonary damage component is derived and calibrated based on published animal experiments; scaling laws are used to predict the human response to lung injury in terms of physical performance decrement. Results The augmented dynamic physiology model (DPM) accurately predicted the human response to hypoxia, altitude, and exercise observed experimentally. The pulmonary damage parameters (shunt and diffusing capacity reduction) were fit to experimental animal data obtained in blast, blunt trauma, and chemical damage studies which link lung damage to lung weight change; the model is able to predict the reduced oxygen delivery in damage conditions. The model accurately estimates physical performance reduction with pulmonary damage. Conclusions We have developed a physiologically-based mathematical model to predict performance decrement endpoints in the presence of thoracic damage; simulations can be extended to estimate human performance and escape in extreme situations. PMID:25044032

Examining the Impact of Video Modeling Techniques on the Efficacy of Clinical Voice Assessment.

PubMed

Werner, Cara; Bowyer, Samantha; Weinrich, Barbara; Gottliebson, Renee; Brehm, Susan Baker

2017-01-01

The purpose of the current study was to determine whether or not presenting patients with a video model improves efficacy of the assessment as defined by efficiency and decreased variability in trials during the acoustic component of voice evaluations. Twenty pediatric participants with a mean age of 7.6 years (SD = 1.50; range = 6-11 years), 32 college-age participants with a mean age of 21.32 years (SD = 1.61; range = 18-30 years), and 17 adult participants with a mean age of 54.29 years (SD = 2.78; range = 50-70 years) were included in the study and divided into experimental and control groups. The experimental group viewed a training video prior to receiving verbal instructions and performing acoustic assessment tasks, whereas the control group received verbal instruction only prior to completing the acoustic assessment. Primary measures included the number of clinician cues required and instructional time. Standard deviations of acoustic measurements (eg, minimum and maximum frequency) were also examined to determine effects on stability. Individuals in the experimental group required significantly less cues, P = 0.012, compared to the control group. Although some trends were observed in instructional time and stability of measurements, no significant differences were observed. The findings of this study may be useful for speech-language pathologists in regard to improving assessment of patients' voice disorders with the use of video modeling. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Nonspherical particles in a pseudo‐2D fluidized bed: Experimental study

PubMed Central

Mahajan, Vinay V.; Nijssen, Tim M. J.; Buist, Kay A.; Kuipers, J. A. M.

2018-01-01

Fluidization is widely used in industries and has been extensively studied, both experimentally and theoretically, in the past. However, most of these studies focus on spherical particles while in practice granules are rarely spherical. Particle shape can have a significant effect on fluidization characteristics. It is therefore important to study the effect of particle shape on fluidization behavior in detail. In this study, experiments in pseudo‐2D fluidized beds are used to characterize the fluidization of spherocylindrical (rod‐like) Geldart D particles of aspect ratio 4. Pressure drop and optical measurement methods (Digital Image Analysis, Particle Image Velocimetry, Particle Tracking Velocimetry) are employed to measure bed height, particle orientation, particle circulation, stacking, and coordination number. The commonly used correlations to determine the pressure drop across a bed of nonspherical particles are compared to experiments. Experimental observations and measurements have shown that rod‐like particles are prone to interlocking and channeling behavior. Well above the minimum fluidization velocity, vigorous bubbling fluidization is observed, with groups of interlocked particles moving upwards, breaking up, being thrown high in the freeboard region and slowly raining down as dispersed phase. At high flowrates, a circulation pattern develops with particles moving up through the center and down at the walls. Particles tend to orient themselves along the flow direction. © 2018 The Authors AIChE Journal published by Wiley Periodicals, Inc. on behalf of American Institute of Chemical Engineers AIChE J, 64: 1573–1590, 2018 PMID:29706659

Studies on absorption coefficient near edge of multi elements

NASA Astrophysics Data System (ADS)

Eisa, M. H.; Shen, H.; Yao, H. Y.; Mi, Y.; Zhou, Z. Y.; Hu, T. D.; Xie, Y. N.

2005-12-01

X-ray absorption near edge structure (XANES) was used to study the near edge mass-absorption coefficients of seven elements, such as, Ti, V, Fe, Co, Ni, Cu and Zn. It is well known that, on the near edge absorption of element, when incident X-ray a few eV change can make the absorption coefficient an order magnitude alteration. So that, there are only a few points mass-absorption coefficient at the near edge absorption and that always average value in published table. Our results showed a wide range of data, the total measured data of mass-absorption coefficient of the seven elements was about 505. The investigation confirmed that XANES is useful technique for multi-element absorption coefficient measurement. Details of experimental methods and results are given and discussed. The experimental work has been performed at Beijing Synchrotron Radiation Facility. The measured values were compared with the published data. Good agreement between experimental results and published data is obtained.

[Effect of training intensity on the fat oxidation rate].

PubMed

Ulloa, David; Feriche, Belén; Barboza, Paola; Padial, Paulino

2014-01-01

Physical exercise is a key modulator of the maximum fat oxidation rate (MFO). However, the metabolic transition zones in the MFO-exercise relationship are not generally considered for training prescription. Objective. To examine the effects of training in different metabolic transition zones on the kinetics of MFO and its localization (Fatmax) in young physically active men. 97 men were divided into 4 similar sized groups, 3 experimental groups and a control group (CG). Subjects in each experimental group undertook an 8-week running program. Training was continuous at the intensity of the aerobic threshold or VT1 (CCVT1); or performed as intervals at the intensity of the anaerobic threshold or VT2 (ITVT2); or at maximum aerobic power VO2max (ITVO2max). Before and after the training intervention, expired gases were monitored in each subject to determine VO2max, VT1, VT2, MFO (by indirect calorimetry) and Fatmax. In response to training, experimental groups showed an increase in MFO (from 16,49 to 18,51%; p<0,01) and a mean reduction in Fatmax of 60,72±10,52 to 52,35±7,61 %VO2max (p<0,01). No changes of interest were observed in the control subjects. Intergroup comparisons revealed no differences in MFO and Fatmax among the experimental groups, though compared to the CG, a greater reduction in Fatmax was observed in CCVT1 (p<0,05). No changes were detected in performance except a drop in VO2max in the GC (p<0,05). 8 weeks of training led to an increase in MFO and reduction in Fatmax irrespective of training intensity. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

Polymerization kinetics of experimental bioactive composites containing bioactive glass.

PubMed

Par, Matej; Tarle, Zrinka; Hickel, Reinhard; Ilie, Nicoleta

2018-06-21

To investigate the polymerization kinetics and the degree of conversion (DC) of experimental resin composites with varying amount of bioactive glass 45S5 (BG). Experimental resin composites based on a photo-curable Bis-GMA/TEGDMA resin system were prepared. The composite series contained 0, 5, 10, 20, and 40 wt% of BG and reinforcing fillers up to the total filler amount of 70 wt%. Composite specimens were light cured with 1,219 mW/cm 2 for 20 or 40 s and their DC was monitored during 5 min at the data collection rate of 2 s -1 using attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). The 5-min DC values for experimental composites were in the range of 42.4-55.9% and 47.3-57.9% for curing times of 20 and 40 s, respectively. The differences in the 5-min DC between curing times of 20 s or 40 s became more pronounced in materials with higher BG amount. Within both curing times, a decreasing trend of the 5-min DC values was observed with the increasing percentage of BG fillers. The maximum polymerization rate also decreased consistently with the increasing BG amount. Unsilanized BG fillers showed a dose-dependent inhibitory effect on polymerization rate and the DC. Extending the curing time from 20 to 40 s showed a limited potential to improve the DC of composites with higher BG amount. The observed inhibitory effect of BG fillers on the polymerization of resin composites may have a negative influence on mechanical properties and biocompatibility. Copyright © 2018. Published by Elsevier Ltd.

Accounting for oxygen in the renal cortex: a computational study of factors that predispose the cortex to hypoxia.

PubMed

Lee, Chang-Joon; Gardiner, Bruce S; Ngo, Jennifer P; Kar, Saptarshi; Evans, Roger G; Smith, David W

2017-08-01

We develop a pseudo-three-dimensional model of oxygen transport for the renal cortex of the rat, incorporating both the axial and radial geometry of the preglomerular circulation and quantitative information regarding the surface areas and transport from the vasculature and renal corpuscles. The computational model was validated by simulating four sets of published experimental studies of renal oxygenation in rats. Under the control conditions, the predicted cortical tissue oxygen tension ([Formula: see text]) or microvascular oxygen tension (µPo 2 ) were within ±1 SE of the mean value observed experimentally. The predicted [Formula: see text] or µPo 2 in response to ischemia-reperfusion injury, acute hemodilution, blockade of nitric oxide synthase, or uncoupling mitochondrial respiration, were within ±2 SE observed experimentally. We performed a sensitivity analysis of the key model parameters to assess their individual or combined impact on the predicted [Formula: see text] and µPo 2 The model parameters analyzed were as follows: 1 ) the major determinants of renal oxygen delivery ([Formula: see text]) (arterial blood Po 2 , hemoglobin concentration, and renal blood flow); 2 ) the major determinants of renal oxygen consumption (V̇o 2 ) [glomerular filtration rate (GFR) and the efficiency of oxygen utilization for sodium reabsorption (β)]; and 3) peritubular capillary surface area (PCSA). Reductions in PCSA by 50% were found to profoundly increase the sensitivity of [Formula: see text] and µPo 2 to the major the determinants of [Formula: see text] and V̇o 2 The increasing likelihood of hypoxia with decreasing PCSA provides a potential explanation for the increased risk of acute kidney injury in some experimental animals and for patients with chronic kidney disease. Copyright © 2017 the American Physiological Society.

The R-factor gap in macromolecular crystallography: an untapped potential for insights on accurate structures.

PubMed

Holton, James M; Classen, Scott; Frankel, Kenneth A; Tainer, John A

2014-09-01

In macromolecular crystallography, the agreement between observed and predicted structure factors (Rcryst and Rfree ) is seldom better than 20%. This is much larger than the estimate of experimental error (Rmerge ). The difference between Rcryst and Rmerge is the R-factor gap. There is no such gap in small-molecule crystallography, for which calculated structure factors are generally considered more accurate than the experimental measurements. Perhaps the true noise level of macromolecular data is higher than expected? Or is the gap caused by inaccurate phases that trap refined models in local minima? By generating simulated diffraction patterns using the program MLFSOM, and including every conceivable source of experimental error, we show that neither is the case. Processing our simulated data yielded values that were indistinguishable from those of real data for all crystallographic statistics except the final Rcryst and Rfree . These values decreased to 3.8% and 5.5% for simulated data, suggesting that the reason for high R-factors in macromolecular crystallography is neither experimental error nor phase bias, but rather an underlying inadequacy in the models used to explain our observations. The present inability to accurately represent the entire macromolecule with both its flexibility and its protein-solvent interface may be improved by synergies between small-angle X-ray scattering, computational chemistry and crystallography. The exciting implication of our finding is that macromolecular data contain substantial hidden and untapped potential to resolve ambiguities in the true nature of the nanoscale, a task that the second century of crystallography promises to fulfill. Coordinates and structure factors for the real data have been submitted to the Protein Data Bank under accession 4tws. © 2014 The Authors. FEBS Journal published by John Wiley & Sons Ltd on behalf of FEBS.

Testing the Implementation of the Veder Contact Method: A Theatre-Based Communication method in Dementia Care.

PubMed

Boersma, Petra; van Weert, Julia C M; Lissenberg-Witte, Birgit I; van Meijel, Berno; Dröes, Rose-Marie

2018-01-08

There is a lack of research on implementation of person-centered care in nursing home care. The purpose of this study was to assess the implementation of the Veder contact method (VCM), a new person-centered method using theatrical, poetic and musical communication for application in 24-hr care. Caregivers (n = 136) and residents (n = 141) participated in a 1-year quasi-experimental study. Foundation Theater Veder implemented VCM on six experimental wards and rated implementation quality. Six control wards delivered care-as-usual. Before and after implementation, caregiver behavior was assessed during observations using the Veder-observation list and Quality of Caregivers' Behavior-list. Caregiver attitude was rated with the Approaches to Dementia Questionnaire. Quality of life, behavior, and mood of the residents were measured with QUALIDEM, INTERACT and FACE. Residents' care plans were examined for person-centered background information. Significant improvements in caregivers' communicative behavior (i.e., the ability to apply VCM, establishing positive interactions) and some aspects of residents' behavior and quality of life (i.e., positive affect, social relations) were found on the experimental wards with a high implementation score, as compared to the experimental wards with a low implementation score, and the control wards. No significant differences were found between the groups in caregivers' attitudes, residents' care plans, or mood. The positive changes in caregivers' behavior and residents' well-being on the high implementation score wards confirm the partly successful VCM implementation. Distinguishing between wards with a high and low implementation score provided insight into factors which are crucial for successful implementation. © The Author(s) 2018. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Stable Rat Model of Mechanical Allodynia in Diabetic Peripheral Neuropathy: The Role of Nerve Compression.

PubMed

Liao, Chenlong; Yang, Min; Liu, Pengfei; Zhong, Wenxiang; Zhang, Wenchuan

2018-05-01

 Preclinical studies involving animal models are essential for understanding the underlying mechanisms of diabetic neuropathic pain.  Rats were divided into four groups: two controls and two experimental. Diabetes mellitus was induced by streptozotocin (STZ) injection in two experimental groups. The first group involved one sham operation. The second group involved one latex tube encircling the sciatic nerve. The vehicle-injection rats were used as two corresponding control groups: sham operation and encircled nerves. By the third week, STZ-injected rats with encircled nerves were further divided into three subgroups: one involving continuing observation and the other two involving decompression (removal of the latex tube) at different time points (third week and fifth week). Weight and blood glucose were monitored, and behavioral analysis, including paw withdrawal threshold (PWT) and latency, was performed every week during the experimental period (7 weeks).  Hyperglycemia was induced in all STZ-injected rats. A significant increase in weight was observed in the control groups when compared with the experimental groups. By the third week, more STZ-injected rats with encircled nerves developed mechanical allodynia than those without ( P  < 0.05), while no significant difference was noted ( P  > 0.05) on the incidence of thermal hyperalgesia. Mechanical allodynia, but not thermal hyperalgesia, could be ameliorated by the removal of the latex tube at an early stage (third week).  With the combined use of a latex tube and STZ injection, a stable rat model of painful diabetic peripheral neuropathy (DPN) manifesting both thermal hyperalgesia and mechanical allodynia has been established. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Dysmenorrhoea is associated with central changes in otherwise healthy women.

PubMed

Vincent, Katy; Warnaby, Catherine; Stagg, Charlotte J; Moore, Jane; Kennedy, Stephen; Tracey, Irene

2011-09-01

Patients with chronic pain conditions demonstrate altered central processing of experimental noxious stimuli, dysfunction of the hypothalamic-pituitary-adrenal axis, and reduced quality of life. Dysmenorrhoea is not considered a chronic pain condition, but is associated with enhanced behavioural responses to experimental noxious stimuli. We used behavioural measures, functional magnetic resonance imaging, and serum steroid hormone levels to investigate the response to experimental thermal stimuli in otherwise healthy women, with and without dysmenorrhoea. Women with dysmenorrhoea reported increased pain to noxious stimulation of the arm and abdomen throughout the menstrual cycle; no menstrual cycle effect was observed in either group. During menstruation, deactivation of brain regions in response to noxious stimulation was observed in control women but not in women with dysmenorrhoea. Without background pain (ie, in nonmenstrual phases), activity in the entorhinal cortex appeared to mediate the increased responses in women with dysmenorrhoea. Mean cortisol was significantly lower in women with dysmenorrhoea and was negatively correlated with the duration of the symptom. Additionally, women with dysmenorrhoea reported significantly lower physical but not mental quality of life. Thus, many features of chronic pain conditions are also seen in women with dysmenorrhoea: specifically a reduction in quality of life, suppression of the hypothalamic-pituitary-adrenal axis, and alterations in the central processing of experimental noxious stimuli. These alterations persist when there is no background pain and occur in response to stimuli at a site distant from that of the clinical pain. These findings indicate the potential importance of early and adequate treatment of dysmenorrhoea. Copyright © 2011 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

Coherent evolution of parahydrogen induced polarisation using laser pump, NMR probe spectroscopy: Theoretical framework and experimental observation.

PubMed

Halse, Meghan E; Procacci, Barbara; Henshaw, Sarah-Louise; Perutz, Robin N; Duckett, Simon B

2017-05-01

We recently reported a pump-probe method that uses a single laser pulse to introduce parahydrogen (p-H 2 ) into a metal dihydride complex and then follows the time-evolution of the p-H 2 -derived nuclear spin states by NMR. We present here a theoretical framework to describe the oscillatory behaviour of the resultant hyperpolarised NMR signals using a product operator formalism. We consider the cases where the p-H 2 -derived protons form part of an AX, AXY, AXYZ or AA'XX' spin system in the product molecule. We use this framework to predict the patterns for 2D pump-probe NMR spectra, where the indirect dimension represents the evolution during the pump-probe delay and the positions of the cross-peaks depend on the difference in chemical shift of the p-H 2 -derived protons and the difference in their couplings to other nuclei. The evolution of the NMR signals of the p-H 2 -derived protons, as well as the transfer of hyperpolarisation to other NMR-active nuclei in the product, is described. The theoretical framework is tested experimentally for a set of ruthenium dihydride complexes representing the different spin systems. Theoretical predictions and experimental results agree to within experimental error for all features of the hyperpolarised 1 H and 31 P pump-probe NMR spectra. Thus we establish the laser pump, NMR probe approach as a robust way to directly observe and quantitatively analyse the coherent evolution of p-H 2 -derived spin order over micro-to-millisecond timescales. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Gist of Dr. Katsusaburo Yamagiwa's papers entitled "Experimental study on the pathogenesis of epithelial tumors" (I to VI reports).

PubMed

Fujiki, Hirota

2014-02-01

The concept of cancer and inflammation has a long history. Virchow's irritation theory based on human cancer engendered the essential role of inflammation in carcinogenesis. Drs. Yamagiwa and Ichikawa first published a comprehensive paper entitled "Experimental study on the pathogenesis of epithelial tumors" (I report) in 1915 in German, and went on to publish five more reports (1915-1924) under the same title. They succeeded in demonstrating that inflammation is an important carcinogenic factor, and the mechanisms are now being investigated by numerous scientists all over the world. In order to introduce Yamagiwa's work to modern cancer researchers, the essentials of their six reports have been translated into English as a short review. Scientists' comments on Yamagiwa's contribution are attached by way of introduction. © 2013 The Authors. Cancer Science published by Wiley Publishing Asia Pty Ltd on behalf of Japanese Cancer Association.

Sliding mode disturbance observer-based control of a twin rotor MIMO system.

PubMed

Rashad, Ramy; El-Badawy, Ayman; Aboudonia, Ahmed

2017-07-01

This work proposes a robust tracking controller for a helicopter laboratory setup known as the twin rotor MIMO system (TRMS) using an integral sliding mode controller. To eliminate the discontinuity in the control signal, the controller is augmented by a sliding mode disturbance observer. The actuator dynamics is handled using a backstepping approach which is applicable due to the continuous chattering-free nature of the command signals generated using the disturbance observer based controller. To avoid the complexity of analytically differentiating the command signals, a first order sliding mode differentiator is used. Stability analysis of the closed loop system and the ultimate boundedness of the tracking error is proved using Lyapunov stability arguments. The proposed controller is validated by several simulation studies and is compared to other schemes in the literature. Experimental results using a hardware-in-the-loop system validate the robustness and effectiveness of the proposed controller. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

The occultation of Epsilon Geminorum by Mars - Analysis of McDonald data. [turbulent scintillation in light curves

NASA Technical Reports Server (NTRS)

Africano, J.; De Vaucouleurs, G.; Evans, D. S.; Finkel, B. E.; Nather, R. E.; Palm, C.; Silverberg, E.; Wiant, J.; Hubbard, W. B.; Jokipii, J. R.

1977-01-01

An analysis of observations of the occultation of Epsilon Gem by Mars on April 8, 1976, is presented. The data were obtained by three neighboring telescopes at McDonald Observatory. Intensity fluctuations on time scales of the order of 100 ms were observed simultaneously at the three telescopes. As the observations compare well with predictions of turbulent scintillation theory, it is concluded that such fluctuations were probably largely the effect of stellar scintillations in the Martian atmosphere. The stellar diameter is included as a parameter in the theory but in a way which differs from previously published interpretations of occultations of extended sources by planetary atmospheres. Scintillations govern the experimental uncertainty in the deduction of the scale height of the high Martian atmosphere. A density scale height of 9.9 + or - 2.5 km is obtained at an altitude of 74 + or - 8 km above the mean surface. For CO 2 gas, this result corresponds to a temperature of 190 + or - 50 K.

Experimental Study of the Richtmyer-Meshkov Instability of Incompressible Fluids

NASA Technical Reports Server (NTRS)

Niederhaus, Charles; Jacobs, Jeffrey W.

2002-01-01

The Richtmyer-Meshkov instability of a low Atwood number, miscible, two-liquid system is investigated experimentally. The initially stratified fluids are contained within a rectangular tank mounted to a sled that rides on a vertical set of rails. The instability is generated by dropping the sled onto a coil spring, producing a nearly impulsive upward acceleration. The subsequent freefall that occurs as the container travels upward and then downward on the rails allows the instability to evolve in the absence of gravity. The interface separating the two liquids initially has a well-defined, sinusoidal perturbation that quickly inverts and then grows in amplitude after undergoing the impulsive acceleration. Disturbance amplitudes are measured and compared to theoretical predictions. Linear stability theory gives excellent agreement with the measured initial growth rate, a(sub 0), for single-mode perturbations with the predicted amplitudes differing by less than 10% from experimental measurements up to a nondimensional time ka(sub 0)t = 0.7, where k is the wavenumber. Linear stability theory also provides excellent agreement for the individual mode amplitudes of multi-mode initial perturbations up until the interface becomes multi-valued. Comparison with previously published weakly nonlinear single-mode models shows good agreement up to ka(sub 0)t = 3, while published nonlinear single-mode models provide good agreement up to ka(sub 0)t = 30. The effects of Reynolds number on the vortex core evolution and overall growth rate of the interface are also investigated. Measurements of the overall amplitude are found to be unaffected by the Reynolds number for the range of values studied here. However, experiments carried out at lower values of Reynolds numbers were found to have decreased vortex core rotation rates. In addition, an instability in the vortex cores is observed.

The use of nonhuman primates in research on seasonal, pandemic and avian influenza, 1893–2014

PubMed Central

Davis, A. Sally; Taubenberger, Jeffery K.; Bray, Mike

2015-01-01

Attempts to reproduce the features of human influenza in laboratory animals date from the early 1890s, when Richard Pfeiffer inoculated apes with bacteria recovered from influenza patients and produced a mild respiratory illness. Numerous studies employing nonhuman primates (NHPs) were performed during the 1918 pandemic and the following decade. Most used bacterial preparations to infect animals, but some sought a filterable agent for the disease. Since the viral etiology of influenza was established in the early 1930s, studies in NHPs have been supplemented by a much larger number of experiments in mice, ferrets and human volunteers. However, the emergence of a novel swine-origin H1N1 influenza virus in 1976 and the highly pathogenic H5N1 avian influenza virus in 1997 stimulated an increase in NHP research, because these agents are difficult to study in naturally infected patients and cannot be administered to human volunteers. In this paper, we review the published literature on the use of NHPs in influenza research from 1893 through the end of 2014. The first section summarizes observational studies of naturally occurring influenza-like syndromes in wild and captive primates, including serologic investigations. The second provides a chronological account of experimental infections of NHPs, beginning with Pfeiffer’s study and covering all published research on seasonal and pandemic influenza viruses, including vaccine and antiviral drug testing. The third section reviews experimental infections of NHPs with avian influenza viruses that have caused disease in humans since 1997. The paper concludes with suggestions for further studies to more clearly define and optimize the role of NHPs as experimental animals for influenza research. PMID:25746173

Influence of Cholesterol on the Oxygen Permeability of Membranes: Insight from Atomistic Simulations.

PubMed

Dotson, Rachel J; Smith, Casey R; Bueche, Kristina; Angles, Gary; Pias, Sally C

2017-06-06

Cholesterol is widely known to alter the physical properties and permeability of membranes. Several prior works have implicated cell membrane cholesterol as a barrier to tissue oxygenation, yet a good deal remains to be explained with regard to the mechanism and magnitude of the effect. We use molecular dynamics simulations to provide atomic-resolution insight into the influence of cholesterol on oxygen diffusion across and within the membrane. Our simulations show strong overall agreement with published experimental data, reproducing the shapes of experimental oximetry curves with high accuracy. We calculate the upper-limit transmembrane oxygen permeability of a 1-palmitoyl,2-oleoylphosphatidylcholine phospholipid bilayer to be 52 ± 2 cm/s, close to the permeability of a water layer of the same thickness. With addition of cholesterol, the permeability decreases somewhat, reaching 40 ± 2 cm/s at the near-saturating level of 62.5 mol % cholesterol and 10 ± 2 cm/s in a 100% cholesterol mimic of the experimentally observed noncrystalline cholesterol bilayer domain. These reductions in permeability can only be biologically consequential in contexts where the diffusional path of oxygen is not water dominated. In our simulations, cholesterol reduces the overall solubility of oxygen within the membrane but enhances the oxygen transport parameter (solubility-diffusion product) near the membrane center. Given relatively low barriers to passing from membrane to membrane, our findings support hydrophobic channeling within membranes as a means of cellular and tissue-level oxygen transport. In such a membrane-dominated diffusional scheme, the influence of cholesterol on oxygen permeability is large enough to warrant further attention. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Modeling microbial community structure and functional diversity across time and space.

PubMed

Larsen, Peter E; Gibbons, Sean M; Gilbert, Jack A

2012-07-01

Microbial communities exhibit exquisitely complex structure. Many aspects of this complexity, from the number of species to the total number of interactions, are currently very difficult to examine directly. However, extraordinary efforts are being made to make these systems accessible to scientific investigation. While recent advances in high-throughput sequencing technologies have improved accessibility to the taxonomic and functional diversity of complex communities, monitoring the dynamics of these systems over time and space - using appropriate experimental design - is still expensive. Fortunately, modeling can be used as a lens to focus low-resolution observations of community dynamics to enable mathematical abstractions of functional and taxonomic dynamics across space and time. Here, we review the approaches for modeling bacterial diversity at both the very large and the very small scales at which microbial systems interact with their environments. We show that modeling can help to connect biogeochemical processes to specific microbial metabolic pathways. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

77 FR 61375 - Endangered and Threatened Wildlife and Plants; 12-Month Finding on Petitions To List the Mexican...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-09

... 15915). We published a final rule, ``Establishment of a Nonessential Experimental Population of the... Mexican Wolf Experimental Population Area in central Arizona and New Mexico and designated the reintroduced population as a nonessential experimental population under section 10(j) of the Act. In March of...

The efficacy of vitamin C supplementation on reducing total serum cholesterol in human subjects: a review and analysis of 51 experimental trials

PubMed Central

McRae, Marc P.

2006-01-01

Abstract Objective Observational studies in humans have shown an inverse relationship between plasma vitamin C concentration and total serum cholesterol. However, experimental studies have shown inconsistent results regarding the ability of vitamin C to reduce total serum cholesterol. Methods Published reports of trials studying the effects of vitamin C on serum lipids were identified by a search of Medline from 1966 to 2004. Data from 51 experimental studies comprising of 1666 pooled subjects were selected for analysis. Results A very strong negative association was observed between baseline total serum cholesterol and the percent change in cholesterol (r = −0.585, p<0.001). When subjects were divided into 4 groups based on their baseline total serum cholesterol levels, the following weighted mean percent changes in cholesterol from baseline were observed: normal cholesterol (<199mg/dl): 0.91±6.8% (n=508); borderline high cholesterol (200–239mg/dl): 3.90±5.78% (n=605); high cholesterol (240–279mg/dl): 11.40±7.96% (n=300); severe cholesterol (>280mg/dl): 14.30±8.36% (n=253). A significant inverse relationship was found between the baseline plasma vitamin C concentrations and mean percent change in total cholesterol from baseline (r = −0.500, p<0.005). It was also observed that the high and severe baseline cholesterol groups possessed lower baseline plasma vitamin C concentrations than those in the normal cholesterol groups (0.79 and 0.55 versus 1.24 mg/dl respectively). Conclusion This finding strengthens the hypothesis that the cholesterol lowering and cardio-protective benefit of vitamin C supplementation may be in its ability to elevate plasma vitamin C concentrations in those patients who initially possess lower than normal vitamin C plasma concentrations. PMID:19674666

The 1761 discovery of Venus' atmosphere: Lomonosov and others

NASA Astrophysics Data System (ADS)

Shiltsev, Vladimir

2014-03-01

Russian polymath Mikhail Vasil'evich Lomonosov claimed to have discovered the atmosphere of Venus during the planet's transit over the Sun's disc in 1761. Although several other astronomers observed similar effects during the 1761 and 1769 transits, Lomonosov's claim for priority is the strongest as he was the first to publish a comprehensive scientific report, and the first to offer a detailed explanation of the aureole around Venus at ingress and egress, which was caused by refraction of the sunlight through Venus' atmosphere. His observations, moreover, were successfully reconstructed experimentally using antique telescopes during the 2012 transit. In this paper we review details of Lomonosov's observations (which usually are poorly covered by commentators and often misunderstood); compare other reports of the eighteenth century transit observations, and summarize their findings in a comprehensive table; and address recent calls to reconsider Lomonosov's priority. After reviewing the available documentation we conclude that everything we learned before, during and after the twenty-first century transits only supports further the widely-accepted attribution of the discovery of Venus' atmosphere to Lomonosov.

Outreach-based HIV prevention for injecting drug users: a review of published outcome data.

PubMed Central

Coyle, S L; Needle, R H; Normand, J

1998-01-01

OBJECTIVE: Over the past decade, a body of observational research has accrued about the effects of outreach-based human immunodeficiency virus (HIV) interventions for drug users. The authors reviewed the findings related to postintervention behavior changes and integrated findings across studies to provide the best estimate of program impact. METHODS: The authors conducted a computerized literature search to locate published accounts of HIV intervention effects on drug users. Thirty-six publications covered outreach-based HIV risk reduction interventions for out-of-treatment injecting drug users (IDUs) and reported intervention effects on HIV-related behaviors or HIV seroincidence. Two-thirds of the publications reported that participation in street-based outreach interventions was followed with office-based HIV testing and counseling. The authors described the theoretical underpinnings of outreach intervention components, the content of the interventions, and the outcome measures that investigators used most frequently. The authors also described and critiqued the evaluation study designs that were in place. Because most of the evaluations were based on pretest and posttest measures of behavior rather than on controlled studies, results were examined with respect to accepted criteria for attributing intervention causality, that is, the plausibility of cause and effect, correct temporal sequence, consistency of findings across reports, strength of associations observed, specifically of associations, and dose-response relationships between interventions and observed outcomes. RESULTS: The majority of the published evaluations showed that IDUs in a variety of places and time periods changed their baseline drug-related and sex-related risk behaviors following their participation in a outreach-based HIV risk reduction intervention. More specifically, the publications indicated that IDUs regularly reported significant follow-up reductions in drug injection, multiperson reuse of syringes and needles, multiperson reuse of other injection equipment (cookers, cotton, rinse water), and crack use. The studies also showed significant intervention effects in promoting entry into drug treatment and increasing needle disinfection. Although drug users also significantly reduced sex-related risks and increased condom use, the majority still practiced unsafe sex. One quasi-experimental study found that reductions in injection risk led to significantly reduced HIV seroincidence among outreach participants. Few investigators looked at dosage effects, but two reports suggested that the longer the exposure to outreach-based interventions, the greater the reductions in drug injection frequency. CONCLUSIONS: Accumulated evidence from observational and quasi-experimental studies strongly indicate that outreach-based interventions have been effective in reaching out-of-treatment IDUs, providing the means for behavior changes and inducing behavior change in the desired direction. The findings provide sound evidence that participation in outreach-based prevention programs can lead to lower HIV incidence rates among program participants. PMID:9722807

Experimental artifacts influencing polarization sensitive magneto-Raman spectroscopy

NASA Astrophysics Data System (ADS)

Thirunavukkuarasu, K.; Lu, Z.; Su, L.; Yu, Y.; Cao, L.; Ballotin, M. V.; Christianen, P. C. M.; Zhang, Y.; Smirnov, D.

Since the discovery of graphene, there has been an explosion of research on 2D layered materials such as transition metal dichalcogenides (TMDs). Among several experimental techniques utilized for studying these materials, Raman spectroscopy has proven to be a very powerful tool due to it's sensitivity to layer numbers, interlayer coupling etc. Layered MoS2, member of TMD family, is a typical example with promising applications in nano-optoelectronics. A recent magneto-Raman investigations on MoS2 published by J. Ji etal reported an observation of giant magneto-optical effect. In this work, the intensity of Raman modes exhibited dramatic change in intensities and was attributed to field-induced broken symmetry on Raman scattering cross-section. Due to the ambiguous nature of the interpretation presented in this publication, we performed further Raman studies on MoS2 at high magnetic fields to illustrate the experimental factors overlooked by the previous study. It is highly important to consider the magnetic field-induced rotation of the polarization of the light and its effect on the Raman active phonon modes in anisotropic materials. A detailed report of our magneto-Raman experiments and their outcomes will be presented.

Correlation between Sleep Duration and Risk of Stroke.

PubMed

Patyar, Sazal; Patyar, Rakesh Raman

2015-05-01

Modern lifestyle and job requirements have changed the sleep habits of most of the adult population. Various population-based studies have associated an increase in mortality with either shortened sleep or long sleep duration. Thus a U-shaped relationship between sleep duration and all-cause mortality in both men and women has been suggested. Several studies have found an association between sleep duration and risk of cardiovascular diseases also. Efforts to understand the etiology of stroke have indicated an association between sleep and stroke too. Obstructive sleep apnea, a sleep-related disorder, has been reported to significantly increase the risk of stroke. Moreover, many studies have shown that both short and long sleep durations are related to increased likelihood of diabetes and hypertension, which themselves are risk factors for stroke. Therefore, this review focuses on the correlation between sleep duration and risk of stroke based on the experimental and epidemiologic studies. Although a few experimental studies have reported that partial sleep deprivation may reduce stroke incidence and severity, yet, most experimental and observational studies have indicated a strong association between short/long sleep durations and higher risk of stroke. Copyright © 2015 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Effects of Epstein's TARGET on adolescents' intentions to be physically active and leisure-time physical activity.

PubMed

Cecchini, Jose A; Fernandez-Rio, Javier; Mendez-Gimenez, Antonio

2014-06-01

The aim of this study was to examine the effects of Epstein's TARGET strategies on adolescents' intentions to be physically active and leisure-time physical activity (LTPA) levels. A total of 447 secondary education students (193 females and 254 males), range age 12-17 years, were divided in two groups: control (N = 224) and experimental (N = 223). Epstein's TARGET strategies were applied by especially trained teachers only to the experimental group in their physical education (PE) classes during 12 consecutive weeks. Participants' intentions to be physically active and their LTPA levels were assessed prior to the intervention (pre), at the end of it (post-1) and 3 months after the intervention (post-2). Significant increases were observed only in the experimental group in post-1 and post-2 on both variables. PE interventions based on TARGET strategies seem to be effective increasing adolescents' intentions to be physically active, as well as time spent in LTPA. As most adolescents participate in PE, these interventions could lead to substantial public health benefits. © The Author 2014. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Calorie menu labeling on quick-service restaurant menus: an updated systematic review of the literature.

PubMed

Swartz, Jonas J; Braxton, Danielle; Viera, Anthony J

2011-12-08

Nutrition labels are one strategy being used to combat the increasing prevalence of overweight and obesity in the United States. The Patient Protection and Affordable Care Act of 2010 mandates that calorie labels be added to menu boards of chain restaurants with 20 or more locations. This systematic review includes seven studies published since the last review on the topic in 2008. Authors searched for peer-reviewed studies using PUBMED and Google Scholar. Included studies used an experimental or quasi-experimental design comparing a calorie-labeled menu with a no-calorie menu and were conducted in laboratories, college cafeterias, and fast food restaurants. Two of the included studies were judged to be of good quality, and five of were judged to be of fair quality. Observational studies conducted in cities after implementation of calorie labeling were imprecise in their measure of the isolated effects of calorie labels. Experimental studies conducted in laboratory settings were difficult to generalize to real world behavior. Only two of the seven studies reported a statistically significant reduction in calories purchased among consumers using calorie-labeled menus. The current evidence suggests that calorie labeling does not have the intended effect of decreasing calorie purchasing or consumption.

Detection of free nickel monocarbonyl, NiCO: rotational spectrum and structure.

PubMed

Yamazaki, Emi; Okabayashi, Toshiaki; Tanimoto, Mitsutoshi

2004-02-04

Unsaturated transition metal carbonyls are important in processes such as organometallic synthesis, homogeneous catalysis, and photochemical decomposition of organometallics. In particular, a metal monocarbonyl offers a zeroth-order model for interpreting the chemisorption of a CO molecule on a metal surface in catalytic activation processes. Quite large numbers of theoretical papers have appeared which predict spectroscopic and structural properties of transition metal carbonyls. The nickel monocarbonyl NiCO has been one of the metal carbonyls most extensively studied by the theoretical calculations. At least 50 theoretical studies have been published on this simplest transition metal carbonyl up to the present time. However, experimental evidence of NiCO is much more sparse than theoretical predictions, and the actual structure of NiCO has never been determined by any experimental methods. This Communication reports the first preparation of free nickel monocarbonyl and observation of its rotational transitions. The NiCO molecule was generated by the sputtering reaction of a Ni cathode in the presence of CO. The accurate bond lengths of Ni-C and C-O were experimentally determined from isotopic data and were compared with the theoretical predictions for the first time.

Nuclear Data Sheets for A = 152

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

Martin, M.J.

2013-11-15

Detailed level schemes, decay schemes, and the experimental data on which they are based are presented for all nuclei with mass number A=152. The experimental data are evaluated; inconsistencies and discrepancies are noted; and adopted values for level and γ–ray energies, γ intensities, as well as for other nuclear properties are given. This evaluation replaces the A=152 evaluation published by Agda Artna–Cohen in Nuclear Data Sheets 79, 1 (1996) and the evaluation for 152Dy prepared by Balraj Singh and published in Nuclear Data Sheets 95, 995 (2002)

Continuation of a Postdoctoral Research Associateship Program

DTIC Science & Technology

1998-12-01

ODRS and LPO can be alleviated by nitric oxide. Rsearch in Progress: The experimental part of the research has been completed. The experimental ... Rsearch in Progress: The experimental part of the research has been completed. The experimental results have been published, or prepared for...construed as an official Department of the Army position, policy or decision unless so designated by other documentation. •*•*«, 19990521 029 fPII

Experimental Demonstration of the Microscopic Origin of Circular Dichroism in Two dimensional Metamaterials

DTIC Science & Technology

2016-06-22

ARTICLE Received 16 Sep 2015 | Accepted 25 May 2016 | Published 22 Jun 2016 Experimental demonstration of the microscopic origin of circular...dissipation of the constituent metamolecules. Because such dissipation occurs on a nanoscale, this effect has never been experimentally probed and...never been experimentally verified because of the challenge of measuring non-radiative loss on the nanoscale. In this study we use a combination of

Molecular motion in cell membranes: Analytic study of fence-hindered random walks

NASA Astrophysics Data System (ADS)

Kenkre, V. M.; Giuggioli, L.; Kalay, Z.

2008-05-01

A theoretical calculation is presented to describe the confined motion of transmembrane molecules in cell membranes. The study is analytic, based on Master equations for the probability of the molecules moving as random walkers, and leads to explicit usable solutions including expressions for the molecular mean square displacement and effective diffusion constants. One outcome is a detailed understanding of the dependence of the time variation of the mean square displacement on the initial placement of the molecule within the confined region. How to use the calculations is illustrated by extracting (confinement) compartment sizes from experimentally reported published observations from single particle tracking experiments on the diffusion of gold-tagged G -protein coupled μ -opioid receptors in the normal rat kidney cell membrane, and by further comparing the analytical results to observations on the diffusion of phospholipids, also in normal rat kidney cells.

Theory of Electron, Phonon and Spin Transport in Nanoscale Quantum Devices.

PubMed

Sadeghi, Hatef

2018-06-21

At the level of fundamental science, it was recently demonstrated that molecular wires can mediate long-range phase-coherent tunnelling with remarkably low attenuation over a few nanometre even at room temperature. Furthermore, a large mean free path has been observed in graphene and other graphene-like two-dimensional materials. These create the possibility of using quantum and phonon interference to engineer electron and phonon transport for wide range of applications such as molecular switches, sensors, piezoelectricity, thermoelectricity and thermal management. To understand transport properties of such devices, it is crucial to calculate their electronic and phononic transmission coefficients. The aim of this tutorial article is to review the state-of-art theoretical and mathematical techniques to treat electron, phonon and spin transport in nanoscale molecular junctions. This helps not only to explain new phenomenon observed experimentally but also provides a vital design tool to develop novel nanoscale quantum devices. © 2018 IOP Publishing Ltd.

Robust iterative learning contouring controller with disturbance observer for machine tool feed drives.

PubMed

Simba, Kenneth Renny; Bui, Ba Dinh; Msukwa, Mathew Renny; Uchiyama, Naoki

2018-04-01

In feed drive systems, particularly machine tools, a contour error is more significant than the individual axial tracking errors from the view point of enhancing precision in manufacturing and production systems. The contour error must be within the permissible tolerance of given products. In machining complex or sharp-corner products, large contour errors occur mainly owing to discontinuous trajectories and the existence of nonlinear uncertainties. Therefore, it is indispensable to design robust controllers that can enhance the tracking ability of feed drive systems. In this study, an iterative learning contouring controller consisting of a classical Proportional-Derivative (PD) controller and disturbance observer is proposed. The proposed controller was evaluated experimentally by using a typical sharp-corner trajectory, and its performance was compared with that of conventional controllers. The results revealed that the maximum contour error can be reduced by about 37% on average. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

Sensorless control of ship propulsion interior permanent magnet synchronous motor based on a new sliding mode observer.

PubMed

Ren, Jun-Jie; Liu, Yan-Cheng; Wang, Ning; Liu, Si-Yuan

2015-01-01

This paper proposes a sensorless speed control strategy for ship propulsion interior permanent magnet synchronous motor (IPMSM) based on a new sliding-mode observer (SMO). In the SMO the low-pass filter and the method of arc-tangent calculation of extended electromotive force (EMF) or phase-locked loop (PLL) technique are not used. The calculation of the rotor speed is deduced from the Lyapunov function stability analysis. In order to reduce system chattering, sigmoid functions with switching gains being adaptively updated by fuzzy logic systems are innovatively incorporated into the SMO. Finally, simulation results for a 4.088 MW ship propulsion IPMSM and experimental results from a 7.5 kW IPMSM drive are provided to verify the effectiveness of the proposed SMO method. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

Dynamics of Tumor Heterogeneity Derived from Clonal Karyotypic Evolution.

PubMed

Laughney, Ashley M; Elizalde, Sergi; Genovese, Giulio; Bakhoum, Samuel F

2015-08-04

Numerical chromosomal instability is a ubiquitous feature of human neoplasms. Due to experimental limitations, fundamental characteristics of karyotypic changes in cancer are poorly understood. Using an experimentally inspired stochastic model, based on the potency and chromosomal distribution of oncogenes and tumor suppressor genes, we show that cancer cells have evolved to exist within a narrow range of chromosome missegregation rates that optimizes phenotypic heterogeneity and clonal survival. Departure from this range reduces clonal fitness and limits subclonal diversity. Mapping of the aneuploid fitness landscape reveals a highly favorable, commonly observed, near-triploid state onto which evolving diploid- and tetraploid-derived populations spontaneously converge, albeit at a much lower fitness cost for the latter. Finally, by analyzing 1,368 chromosomal translocation events in five human cancers, we find that karyotypic evolution also shapes chromosomal translocation patterns by selecting for more oncogenic derivative chromosomes. Thus, chromosomal instability can generate the heterogeneity required for Darwinian tumor evolution. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Epitaxial Relationships between Calcium Carbonate and Inorganic Substrates

PubMed Central

Yang, Taewook; Jho, Jae Young; Kim, Il Won

2014-01-01

The polymorph-selective crystallization of calcium carbonate has been studied in terms of epitaxial relationship between the inorganic substrates and the aragonite/calcite polymorphs with implication in bioinspired mineralization. EpiCalc software was employed to assess the previously published experimental results on two different groups of inorganic substrates: aragonitic carbonate crystals (SrCO3, PbCO3, and BaCO3) and a hexagonal crystal family (α-Al2O3, α-SiO2, and LiNbO3). The maximum size of the overlayer (aragonite or calcite) was calculated for each substrate based on a threshold value of the dimensionless potential to estimate the relative nucleation preference of the polymorphs of calcium carbonate. The results were in good agreement with previous experimental observations, although stereochemical effects between the overlayer and substrate should be separately considered when existed. In assessing the polymorph-selective nucleation, the current method appeared to provide a better tool than the oversimplified mismatch parameters without invoking time-consuming molecular simulation\\. PMID:25226539

Luigi Galvani's path to animal electricity.

PubMed

Piccolino, Marco

2006-01-01

In spite of the historical importance of the research that, in the second half of the 18th century, led Luigi Galvani (1737-1798) to lay down the foundation of modern electrophysiology, his scientific personality is largely misrepresented in science history and in popular imagery. He is still considered as a pioneer that by chance incurred some surprising experimental observations and was incapable of pursuing his research in a coherent way. In contrast with these views, Galvani was a high-standard scientist who succeeded, with the strength of experimental science, in demonstrating, in animals, electricity in a condition of disequilibrium between the interior and the exterior of excitable fibres. This electricity, called 'animal electricity', was deemed responsible for nerve conduction. By studying the scientific endeavours of Galvani, through his published and unpublished material, and by situating them in the historical context of the physiology of the Enlightenment, this paper attempts to trace the elusive and complex path that led Galvani to his extraordinary discovery. To cite this article: M. Piccolino, C. R. Biologies 329 (2006).

Fe/starch nanoparticle - Pseudomonas aeruginosa: Bio-physiochemical and MD studies.

PubMed

Mofradnia, Soheil Rezazadeh; Tavakoli, Zahra; Yazdian, Fatemeh; Rashedi, Hamid; Rasekh, Behnam

2018-05-03

In this research, we attempt to study biosurfactant production by Pseudomonas aeruginosa using Fe/starch nanoparticles. Fe/starch showed no bacterial toxicity at 1 mg/ml and increased the growth rate and biosurfactant production up to 23.21 and 20.73%, respectively. Surface tension, dry weight cell, and emulsification indexes (E24) were measured. Biosurfactant production was considered via computational techniques and molecular dynamic (MD) simulation through flexible and periodic conditions (by material studio software) as well. The results of software predictions demonstrate by radial distribution function (RDF), density, energy and temperature graphs. According to the present experimental results, increased 30% growth of the bacterium has been observed and the subsequent production of biosurfactant. The difference between the experimental results and simulation data were achieved up to 0.17 g/cm 3 , which confirms the prediction of data by the software due to a difference of <14.5% (ideal error value is 20%). Copyright © 2017. Published by Elsevier B.V.

Bistable Behavior of the Lac Operon in E. Coli When Induced with a Mixture of Lactose and TMG

PubMed Central

Díaz-Hernández, Orlando; Santillán, Moisés

2010-01-01

In this work we investigate multistability in the lac operon of Escherichia coli when it is induced by a mixture of lactose and the non-metabolizable thiomethyl galactoside (TMG). In accordance with previously published experimental results and computer simulations, our simulations predict that: (1) when the system is induced by TMG, the system shows a discernible bistable behavior while, (2) when the system is induced by lactose, bistability does not disappear but excessively high concentrations of lactose would be required to observe it. Finally, our simulation results predict that when a mixture of lactose and TMG is used, the bistability region in the extracellular glucose concentration vs. extracellular lactose concentration parameter space changes in such a way that the model predictions regarding bistability could be tested experimentally. These experiments could help to solve a recent controversy regarding the existence of bistability in the lac operon under natural conditions. PMID:21423364

Theoretical study of ethylbenzenium ions: the mechanism for splitting off ethene, and the formation of a pi complex of ethene and the benzenium ion.

PubMed

Kolboe, Stein; Svelle, Stian; Arstad, Bjørnar

2009-02-05

Structures and energies of protonated ethylbenzene and 2,6-dimethylethylbenzene have been studied by quantum chemical calculations. The main goal is to study the mechanism for splitting off ethene from protonated ethylbenzene. Data are reported for the four ethylbenzenium isomers arising depending on the position of the proton on the benzene ring: a pi complex where ethene is weakly bonded to a benzenium ion and two transition states connected with the cleavage of the ethylbenzenium ion. The larger part of the data that are reported has been obtained at the B3LYP/cc-pVTZ level of theory. Energies obtained by the Gaussian-3 G3B3 composite method are also given. Computations have also been carried out at the MP2/6-311++G(d,p) level of theory. The calculated results can be reconciled with published experimental observations, and they give information about the reaction system that is not obtained by experimental techniques.

Molecular dynamics simulations of a DMSO/water mixture using the AMBER force field.

PubMed

Stachura, Slawomir S; Malajczuk, Chris J; Mancera, Ricardo L

2018-06-25

Due to its protective properties of biological samples at low temperatures and under desiccation, dimethyl sulfoxide (DMSO) in aqueous solutions has been studied widely by many experimental approaches and molecular dynamics (MD) simulations. In the case of the latter, AMBER is among the most commonly used force fields for simulations of biomolecular systems; however, the parameters for DMSO published by Fox and Kollman in 1998 have only been tested for pure liquid DMSO. We have conducted an MD simulation study of DMSO in a water mixture and computed several structural and dynamical properties such as of the mean density, self-diffusion coefficient, hydrogen bonding and DMSO and water ordering. The AMBER force field of DMSO is seen to reproduce well most of the experimental properties of DMSO in water, with the mixture displaying strong and specific water ordering, as observed in experiments and multiple other MD simulations with other non-polarizable force fields. Graphical abstract Hydration structure within hydrogen-bonding distance around a DMSOmolecule.

Effects of intermittent traction therapy in an experimental spinal column model.

PubMed

Shin, Jeong-Hun; Jun, Seung-lyul; Lee, Young-Jun; Kim, Jae-Hyo; Hwang, Sung-Yeoun; Ahn, Seong-Hun

2014-04-01

Traction therapy, which is known to be a treatment method for scoliosis, one of many muscles disease, has been used since Hippocrates introduced it. However, the effects of traction therapy are still not clear. In addition, the meridian sinew theory, which is related to muscle treatment and is mentioned in the book on meridian sinews in the Miraculous Pivot of Huangdi's Internal Classic, has not been the subject of much study. For these reasons, experimental spinal models were made for this study to observe and analyze the lengths of vertebral interspaces after intermittent traction therapy, which is known to be excellent among muscle treatment methods, with various tensile forces. The results showed that the effects of intermittent traction therapy were unclear and that it might be harmful, especially when the pain was induced by muscle weakness. Because the results of this study on intermittent traction therapy were different from those expected from osteopathy or craniosacral theory, better studies of the subject are necessary. Copyright © 2014. Published by Elsevier B.V.

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

Akdoğan, Ender, E-mail: ender.akdogan@tpe.gov.tr; Çiftçi, Muharrem, E-mail: muharrem-ciftci@windowslive.com

This article is based on the master thesis [4] related to our invention which was published in World Intellectual Property Organization (WO/2011/048506) as a microwave water heater. In the project, a prototype was produced to use microwave in industrial heating. In order to produce the prototype, the most appropriate material kind for microwave-water experiments was determined by a new energy loss rate calculation technique. This new energy loss calculation is a determinative factor for material permeability at microwave frequency band (1-100 GHz). This experimental series aim to investigate the rationality of using microwave in heating industry. Theoretically, heating water by microwavemore » (with steady frequency 2.45 GHz) is analyzed from sub-molecular to Classical Mechanic results of heating. In the study, we examined Quantum Mechanical base of heating water by microwave experiments. As a result, we derived a Semi-Quantum Mechanical equation for microwave-water interactions and thus, Wien displacement law can be derived to verify experimental observations by this equation.« less

"Experimental Оncology" is the Best Scientific Journal in Ukraine according to SCOPUS!

PubMed

2016-06-01

International scientific journal "Experimental Оncology" (Publishing House "MORION LLC", Kyiv, Ukraine - R.E. Kavetsky Institute of Experimental Pathology, Oncology and Radiobiology of the NAS of Ukraine, Kyiv, Ukraine) earned high global recognition, receiving the prestigious international award "SCOPUS Awards Ukraine" as a winner in the category "The Best Journal".

Articles Published in Four School Psychology Journals from 2000 to 2005: An Analysis of Experimental/Intervention Research

ERIC Educational Resources Information Center

Bliss, Stacy L.; Skinner, Christopher H.; Hautau, Briana; Carroll, Erin E.

2008-01-01

Using an experimenter-developed system, articles from four school psychology journals for the years 2000-2005 (n = 929) were classified. Results showed that 40% of the articles were narrative, 29% correlational, 16% descriptive, 8% causal-experimental, 4% causal-comparative, and 2% were meta-analytic. Further analysis of the causal-experimental…

The Validity of Communication Experiments Using Human Subjects: A Review

ERIC Educational Resources Information Center

Rossiter, Charles M.

1976-01-01

Reviews sixty-eight experiments published in various journals in 1973 and 1974 and concludes that communication experimentation may be severely limited by the nature of the subjects studied and the inappropriate handling of experimental reactivity. (MH)

Standard of reporting animal-based experimental research in Indian Journal of Pharmacology.

PubMed

Aiman, Umme; Rahman, Syed Ziaur

2015-01-01

The objective of present study was to survey and determine the reporting standards of animal studies published during three years from 2012 to 2014 in the Indian Journal of Pharmacology (IJP). All issues of IJP published in the year 2012, 2013 and 2014 were reviewed to identify animal studies. Each animal study was searched for 15 parameters specifically designed to review standards of animal experimentation and research methodology. All published studies had clearly defined aims and objectives while a statement on ethical clearance about the study protocol was provided in 97% of papers. Information about animal strain and sex was given in 91.8% and 90% of papers respectively. Age of experimental animals was mentioned by 44.4% papers while source of animals was given in 50.8% papers. Randomization was reported by 37.4% while 9.9% studies reported blinding. Only 3.5% studies mentioned any limitations of their work. Present study demonstrates relatively good reporting standards in animal studies published in IJP. The items which need to be improved are randomization, blinding, sample size calculation, stating the limitations of study, sources of support and conflict of interest. The knowledge shared in the present paper could be used for better reporting of animal based experiments.

Prediction of frozen food properties during freezing using product composition.

PubMed

Boonsupthip, W; Heldman, D R

2007-06-01

Frozen water fraction (FWF), as a function of temperature, is an important parameter for use in the design of food freezing processes. An FWF-prediction model, based on concentrations and molecular weights of specific product components, has been developed. Published food composition data were used to determine the identity and composition of key components. The model proposed in this investigation had been verified using published experimental FWF data and initial freezing temperature data, and by comparison to outputs from previously published models. It was found that specific food components with significant influence on freezing temperature depression of food products included low molecular weight water-soluble compounds with molality of 50 micromol per 100 g food or higher. Based on an analysis of 200 high-moisture food products, nearly 45% of the experimental initial freezing temperature data were within an absolute difference (AD) of +/- 0.15 degrees C and standard error (SE) of +/- 0.65 degrees C when compared to values predicted by the proposed model. The predicted relationship between temperature and FWF for all analyzed food products provided close agreements with experimental data (+/- 0.06 SE). The proposed model provided similar prediction capability for high- and intermediate-moisture food products. In addition, the proposed model provided statistically better prediction of initial freezing temperature and FWF than previous published models.

An analysis of orthopaedic theses in Turkey: Evidence levels and publication rates.

PubMed

Koca, Kenan; Ekinci, Safak; Akpancar, Serkan; Gemci, Muhammed Hanifi; Erşen, Ömer; Akyıldız, Faruk

2016-10-01

The aim of this study was to present characteristics and publication patterns of studies arise from orthopedic theses obtained from National Thesis Center; database in terms of publication years, study types, topics, level of evidence between 1974 and 2014. Firstly, National Thesis Center database was searched for orthopedics and Traumatology theses. The theses, which their summary or full text were available were included in the study. The topics, study types and quality of study designs were reviewed. Then theses were searched in the PubMed database. Journals of published theses were classified according to category, scope and impact factors of the year 2014. 1508 theses were included into the study. Clinical studies comprised 71,7% of the theses, while 25,6% of the theses were non-clinical experimental and 2,7% of the theses were observational studies. Clinical studies were Level I in 8,6% (n = 93) and Level II in 5,8% of the theses (n = 63). A total of 224 theses (14,9%) were published in the journals indexed in PubMed database from 1974 to 2012. Fifty-two (23,2%) were published in SCI; 136 theses (60,7%) were published in SCI-E journals and 36 theses (16%) were published in other Journals indexed in PubMed. The quantity and quality of published theses need to be improved and effective measures should be taken to promote quality of theses. Theses from universities and Training hospitals which did not allow open access, and; incomplete records of the National Thesis Center database were major limitations of this study. Copyright © 2016 Turkish Association of Orthopaedics and Traumatology. Production and hosting by Elsevier B.V. All rights reserved.

Histologic evaluation of human pulp tissue after orthodontic intrusion.

PubMed

Lazzaretti, Dieison Nardi; Bortoluzzi, Gianna Steffens; Torres Fernandes, Lauren Fioreze; Rodriguez, Rubens; Grehs, Renésio Armindo; Martins Hartmann, Mateus Silveira

2014-10-01

The forces applied during orthodontic treatment bring about effects on the teeth and surrounding tissues. The aim of this study was to evaluate the possible changes in the human pulpal tissue resulting from orthodontic intrusion in a 21-day period using histologic examination. The sample consisted of 17 young individuals of both sexes between the ages of 12 and 19 years. A total of 34 premolars were evaluated with orthodontic indication of extraction. Because it is a split-mouth study, in each patient, intrusion force of 60 g was applied randomly on 1 of the dental elements experimental group for 21 days. The counterpart control group received no force. After extractions, these dental elements were fixed in 10% formaldehyde, processed automatically, submitted to histotechnical preparation, and stained with hematoxylin-eosin for analysis under optical microscope. The paired Fisher exact test (P ≤ .05) showed a significant increase of fibrous tissue in the experimental group. The nonparametric paired Wilcoxon test (P ≤ .05) showed a significant increase in the number of pulpal nodules in the elements of the experimental group and showed no difference in the number of blood vessels between the groups. Large-caliber vessels and congested elements were observed in 8 of the experimental group elements. The orthodontic intrusion force, in these conditions, caused vascular changes in the pulpal tissue and also increased the presence of fibrosis and the number of pulp calcifications in the experimental elements. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Statistical shear lag model - unraveling the size effect in hierarchical composites.

PubMed

Wei, Xiaoding; Filleter, Tobin; Espinosa, Horacio D

2015-05-01

Numerous experimental and computational studies have established that the hierarchical structures encountered in natural materials, such as the brick-and-mortar structure observed in sea shells, are essential for achieving defect tolerance. Due to this hierarchy, the mechanical properties of natural materials have a different size dependence compared to that of typical engineered materials. This study aimed to explore size effects on the strength of bio-inspired staggered hierarchical composites and to define the influence of the geometry of constituents in their outstanding defect tolerance capability. A statistical shear lag model is derived by extending the classical shear lag model to account for the statistics of the constituents' strength. A general solution emerges from rigorous mathematical derivations, unifying the various empirical formulations for the fundamental link length used in previous statistical models. The model shows that the staggered arrangement of constituents grants composites a unique size effect on mechanical strength in contrast to homogenous continuous materials. The model is applied to hierarchical yarns consisting of double-walled carbon nanotube bundles to assess its predictive capabilities for novel synthetic materials. Interestingly, the model predicts that yarn gauge length does not significantly influence the yarn strength, in close agreement with experimental observations. Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

The combination of two novel tobacco blends and filter technologies to reduce the in vitro genotoxicity and cytotoxicity of prototype cigarettes.

PubMed

Crooks, Ian; Scott, Ken; Dalrymple, Annette; Dillon, Debbie; Meredith, Clive

2015-04-01

Tobacco smoke from a combustible cigarette contains more than 6000 constituents; approximately 150 of these are identified as toxicants. Technologies that modify the tobacco blend to reduce toxicant emissions have been developed. These include tobacco sheet substitute to dilute toxicants in smoke and blend treated tobacco to reduce the levels of nitrogenous precursors and some polyphenols. Filter additives to reduce gas (vapour) phase constituents have also been developed. In this study, both tobacco blend and filter technologies were combined into an experimental cigarette and smoked to International Organisation on Standardisation and Health Canada puffing parameters. The resulting particulate matter was subjected to a battery of in vitro genotoxicity and cytotoxicity assays - the Ames test, mouse lymphoma assay, the in vitro micronucleus test and the Neutral Red Uptake assay. The results indicate that cigarettes containing toxicant reducing technologies may be developed without observing new additional genotoxic hazards as assessed by the assays specified. In addition, reductions in bacterial mutagenicity and mammalian genotoxicity of the experimental cigarette were observed relative to the control cigarettes. There were no significant differences in cytotoxicity relative to the control cigarettes. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Improved modeling of side-chain--base interactions and plasticity in protein--DNA interface design.

PubMed

Thyme, Summer B; Baker, David; Bradley, Philip

2012-06-08

Combinatorial sequence optimization for protein design requires libraries of discrete side-chain conformations. The discreteness of these libraries is problematic, particularly for long, polar side chains, since favorable interactions can be missed. Previously, an approach to loop remodeling where protein backbone movement is directed by side-chain rotamers predicted to form interactions previously observed in native complexes (termed "motifs") was described. Here, we show how such motif libraries can be incorporated into combinatorial sequence optimization protocols and improve native complex recapitulation. Guided by the motif rotamer searches, we made improvements to the underlying energy function, increasing recapitulation of native interactions. To further test the methods, we carried out a comprehensive experimental scan of amino acid preferences in the I-AniI protein-DNA interface and found that many positions tolerated multiple amino acids. This sequence plasticity is not observed in the computational results because of the fixed-backbone approximation of the model. We improved modeling of this diversity by introducing DNA flexibility and reducing the convergence of the simulated annealing algorithm that drives the design process. In addition to serving as a benchmark, this extensive experimental data set provides insight into the types of interactions essential to maintain the function of this potential gene therapy reagent. Published by Elsevier Ltd.

Histological observation of hairless mice skin after exposure to Simulated Solar Light: Comparison between the histological findings with different methodologies and 3R principle correlations.

PubMed

Hossy, Bryan Hudson; Leitão, Alvaro Augusto da Costa; Torres, Renata Bosco; Ramos-E-Silva, Marcia; Miguel, Nádia Campos de Oliveira; de Pádula, Marcelo

2018-03-01

Albino hairless mouse (AHM) has been used as a biological model in photodermatology. However, the experimental landscape is diverse to follow and need particular attention. Irradiation parameters were investigated for the development of a protocol to assess alterations in the AHM skin using Simulated Solar Light (SSL). The present study was compared with published articles (last 15 years) according to irradiation protocols, morphological findings to minimize animal suffering and UV exposure. Three groups: Control (G1), experimental - sunburn (G2) and skin photodamage assay (G3). G2 were immobilized and exposed to SSL once for 15, 30 and 45min. G3 were exposed to SSL, without immobilization, for 15min once a day for one week. The dorsal skin was analyzed using hematoxylin and eosin technique. G2 displayed different sunburn degrees. Based on the profile of the observed morphological alterations, a 15min irradiation was chosen as the exposure time to expose G3, without immobilization, for 5 consecutive days. These conditions produced the same morphological changes in the AHM with a shorter solar exposure time, without immobilizing the animals but using environmental exposure fluences, conforming to 3R (reduction - refinement - replacement) recommendations. Copyright © 2017 Elsevier Ltd and ISBI. All rights reserved.

Representation of Nursing Scientists from German-speaking countries in High Impact Journals. A bibliometric publication analysis

PubMed

Hirt, Julian; Buhtz, Christian; Mersdorf, Benedikt; Meyer, Gabriele

2018-02-01

Background: The frequency of publications by nursing scientists from the German-speaking area in journals with a high impact factor is an indicator for participation of the discipline in the international discourse. Previous publication analyses focused on nursing science journals only and regularly found an underrepresentation of experimental studies and clinical topics. Aim: To identify and analyse the number of publications by nursing scientists from Germany, Austria and German-speaking Switzerland in international high impact journals. Method: The Journal Citation Reports were used to identify nursing relevant categories of journals in which the highest 10 % of the years 2010 to 2014 were selected according to the 5-year Impact Factor. Inclusion of publications and data extraction were carried out by two independent persons. Results: 106939 publications from 126 journals were screened; 100 publications were identified with 229 contributions by 114 nursing scientists. 42 % of studies are observational and 11 % are experimental. The majority of studies are clinically oriented (55 %). More than 50 % have been published in the past two years. Conclusions: The number of publications by nursing scientists from the German-speaking countries in High Impact Journals is low. There is an increase throughout the observation period. In opposite to former analyses a higher proportion of clinical research has been found.

Numerical investigation into blood clotting at the bone-dental implant interface in the presence of an electrical stimulus.

PubMed

Vanegas-Acosta, J C; Garzón-Alvarado, D A; Lancellotti, V

2013-12-01

The insertion of a dental implant activates a sequence of wound healing events ending with bone formation and implant osseointegration. This sequence starts with the blood coagulation process and the formation of a fibrin network that detains spilt blood. Fibrin formation can be simplified as the kinetic reaction between thrombin and fibrinogen preceding the conversion of fibrinogen into fibrin. Based on experimental observations of the electrical properties of these molecules, we present a hypothesis for the mechanism of a static electrical stimulus in controlling the formation of the blood clot. Specifically, the electrical stimulus increases the fibrin network formation in such a way that a preferential region of higher fibrin density is obtained. This hypothesis is validated by means of a numerical model for the blood clot formation at the bone-dental implant interface. Numerical results compare favorably to experimental observations for blood clotting with and without the static electrical stimulus. It is concluded that the density of the fibrin network depends on the strength of the static electrical stimulus, and that the blood clot formation has a preferential direction of formation in the presence of the electrical signal. © 2013 Published by Elsevier Ltd. All rights reserved.

Ultrasonic wave propagation in trabecular bone predicted by the stratified model

NASA Technical Reports Server (NTRS)

Lin, W.; Qin, Y. X.; Rubin, C.

2001-01-01

The objective of this study was to investigate ultrasound propagation in trabecular bone by considering the wave reflection and transmission in a multilayered medium. The use of ultrasound to identify those at risk of osteoporosis is a promising diagnostic method providing a measure of bone mineral density (BMD). A stratified model was proposed to study the effect of transmission and reflection of ultrasound wave within the trabecular architecture on the relationship between ultrasound and BMD. The results demonstrated that ultrasound velocity in trabecular bone was highly correlated with the bone apparent density (r=0.97). Moreover, a consistent pattern of the frequency dependence of ultrasound attenuation coefficient has been observed between simulation using this model and experimental measurement of trabecular bone. The normalized broadband ultrasound attenuation (nBUA) derived from the simulation results revealed that nBUA was nonlinear with respect to trabecular porosity and BMD. The curve of the relationship between nBUA and BMD was parabolic in shape, and the peak magnitude of nBUA was observed at approximately 60% of bone porosity. These results agreed with the published experimental data and demonstrated that according to the stratified model, reflection and transmission were important factors in the ultrasonic propagation through the trabecular bone.

Enhancing Scientific Foundations to Ensure Reproducibility: A New Paradigm.

PubMed

Hsieh, Terry; Vaickus, Max H; Remick, Daniel G

2018-01-01

Progress in science is dependent on a strong foundation of reliable results. The publish or perish paradigm in research, coupled with an increase in retracted articles from the peer-reviewed literature, is beginning to erode the trust of both the scientific community and the public. The NIH is combating errors by requiring investigators to follow new guidelines addressing scientific premise, experimental design, biological variables, and authentication of reagents. Herein, we discuss how implementation of NIH guidelines will help investigators proactively address pitfalls of experimental design and methods. Careful consideration of the variables contributing to reproducibility helps ensure robust results. The NIH, investigators, and journals must collaborate to ensure that quality science is funded, explored, and published. Copyright © 2018 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

New Issues for New Methods: Ethical and Editorial Challenges for an Experimental Philosophy.

PubMed

Polonioli, Andrea

2017-08-01

This paper examines a constellation of ethical and editorial issues that have arisen since philosophers started to conduct, submit and publish empirical research. These issues encompass concerns over responsible authorship, fair treatment of human subjects, ethicality of experimental procedures, availability of data, unselective reporting and publishability of research findings. This study aims to assess whether the philosophical community has as yet successfully addressed such issues. To do so, the instructions for authors, submission process and published research papers of 29 main journals in philosophy have been considered and analyzed. In light of the evidence reported here, it is argued that the philosophical community has as yet failed to properly tackle such issues. The paper also delivers some recommendations for authors, reviewers and editors in the field.

A mathematical model on water redistribution mechanism of the seismonastic movement of Mimosa pudica.

PubMed

Kwan, K W; Ye, Z W; Chye, M L; Ngan, A H W

2013-07-02

A theoretical model based on the water redistribution mechanism is proposed to predict the volumetric strain of motor cells in Mimosa pudica during the seismonastic movement. The model describes the water and ion movements following the opening of ion channels triggered by stimulation. The cellular strain is related to the angular velocity of the plant movement, and both their predictions are in good agreement with experimental data, thus validating the water redistribution mechanism. The results reveal that an increase in ion diffusivity across the cell membrane of <15-fold is sufficient to produce the observed seismonastic movement. Copyright © 2013 Biophysical Society. Published by Elsevier Inc. All rights reserved.

DFT study of the molybdenum-catalyzed deoxydehydration of vicinal diols.

PubMed

Lupp, Daniel; Christensen, Niels Johan; Dethlefsen, Johannes R; Fristrup, Peter

2015-02-16

The mechanism of the molybdenum-catalyzed deoxydehydration (DODH) of vicinal diols has been investigated using density functional theory. The proposed catalytic cycle involves condensation of the diol with an Mo(VI) oxo complex, oxidative cleavage of the diol resulting in an Mo(IV) complex, and extrusion of the alkene. We have compared the proposed pathway with several alternatives, and the results have been corroborated by comparison with the molybdenum-catalyzed sulfoxide reduction recently published by Sanz et al. and with experimental observations for the DODH itself. Improved understanding of the mechanism should expedite future optimization of molybdenum-catalyzed biomass transformations. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Correlated Debye model for atomic motions in metal nanocrystals

NASA Astrophysics Data System (ADS)

Scardi, P.; Flor, A.

2018-05-01

The Correlated Debye model for the mean square relative displacement of atoms in near-neighbour coordination shells has been extended to include the effect of finite crystal size. This correctly explains the increase in Debye-Waller coefficient observed for metal nanocrystals. A good match with Molecular Dynamics simulations of Pd nanocrystals is obtained if, in addition to the phonon confinement effect of the finite domain size, proper consideration is also given to the static disorder component caused by the undercoordination of surface atoms. The new model, which addresses the analysis of the Pair Distribution Function and powder diffraction data collected at different temperatures, was preliminarily tested on recently published experimental data on nanocrystalline Pt powders.

Publication Rate of Avian Medicine Conference Abstracts and Influencing Factors: 2011-2015.

PubMed

Doukaki, Christina; MedVet, Dr; Beaufrère, Hugues; Vet, Dr Med; Huynh, Minh

2018-06-01

International conferences on avian medicine and surgery aim to disseminate scientific and evidence-based information in the form of oral presentations and posters. Most manuscripts presented are printed in the conference proceedings as abstracts. Subsequent publication in a scientific peer-reviewed journal is the natural outcome of the research cycle, although studies have shown that the vast majority of conference abstracts are not published. The purpose of this study was to explore 1) the fate of abstracts presented in avian conferences (Association of Avian Veterinarians, European Association of Avian Veterinarians, International Conference on Avian Herpetological and Exotic Mammal Medicine) in the years 2011-2015, 2) assess the publication rate in peer-reviewed journals, 3) describe the time course of subsequent publication, and 4) identify factors associated with increased likelihood of publication. The results showed that 24% of conference abstracts were published within the next 2 years. Depending on the statistical model used, several factors were identified as associated with increased publication rate. North American papers seem to publish with more frequency (univariate model), while European papers had the opposite trend (multivariable model). Likewise, experimental studies were more prone to being published overall (univariate model), whereas retrospective observational studies had a lower rate of publication (multivariable model). Increasing the number of authors was also associated with increased publication rate. Most publications were published in the Journal of Avian Medicine and Surgery, which tends to suggest that this journal is the main journal of the specialty. Some parameters highlighted in this study may assist conference attendees to assess the likelihood of later publication.

Assessing the scientific research productivity of a leading toxicology journal: A case study of Human & Experimental Toxicology from 2003 to 2012.

PubMed

Zyoud, Sa'ed H; Al-Jabi, Samah W; Sweileh, Waleed M; Awang, Rahmat

2014-01-01

Bibliometric studies are increasingly being used for research assessments. Bibliometric indicators involve the application of statistical methods to scientific publications to obtain the bibliographics for each journal. The main objective of this study was to conduct a bibliometric evaluation of Human & Experimental Toxicology retrieved from the Scopus database. This study obtained data from Scopus published from 1 January 2003 till 31 December 2012. The keywords entered in Scopus to accomplish the objective of this study were 'Human', 'Experimental' and 'Toxicology' as 'Source Title'. Research productivity was evaluated based on a methodology developed and used in other bibliometric studies by analysing (a) total and trends in Human & Experimental Toxicology contributions in research between 2003 and 2012; (b) Human & Experimental Toxicology authorship patterns and productivity; (c) collaboration patterns; and (d) the citations received by the publications. There were 1229 research articles published in Human & Experimental Toxicology. Of the articles included, 947 (77.1%) were original articles and 104 (8.5%) were review articles. The Hirsch-index of the retrieved documents was 35. The largest number of publications in Human & Experimental Toxicology was from the United States (19.6%), followed by India (12.8%) and Turkey (10.9%). The total number of citations was 9119, with a median (interquartile range) of 3 (1-9) in 6797 documents. The highest median (interquartile range) number of citations was 8 (2.7-12.7) for France, followed by 7.5 (2-22.5) for Iran and 6 (3-13.5) for the United Kingdom. The country most often citing articles that were published in Human & Experimental Toxicology was the United States, which made citations in 1508 documents, followed by India with citations in 792 documents. The documents in Human & Experimental Toxicology focus principally on original data, with very few review articles. Review articles tend to have higher citation rates than original articles, and hence, the editors and authors of Human & Experimental Toxicology might usefully promote the submission of reviews in the future to improve the impact of the journal.

Safety and serologic response to a Haemonchus contortus vaccine in alpacas.

PubMed

VanHoy, Grace; Carman, Michelle; Habing, Greg; Lakritz, Jeffrey; Hinds, C Austin; Niehaus, Andrew; Kaplan, Ray M; Marsh, Antoinette E

2018-03-15

Haemonchosis in camelids remains a challenging disease to treat, and prevention has become increasingly problematic due to widespread anthelmintic resistance. Barbervax ® is an adjuvanted vaccine containing natural H-11, H-gal-GP antigens obtained from Haemonchus contortus adults via a proprietary process and solubilized in Quil A. This vaccine is approved for use in Australia, after demonstrating its safety and efficacy in sheep and goats. There are no published studies evaluating Barbervax in other ruminants/pseudoruminants such as camelids which can be parasitized with H. contortus. The vaccine utilizes a mixture of the parasite gut mucosal membrane enzymes including H-gal-GP and H11, involved in digesting a blood meal from the host. This study monitored the safety profile of the Barbervax ® vaccine in a group of adolescent alpacas. Although designed into the original study of vaccine efficacy, the experimental infection with viable H. contortus third stage larvae could not be completed due to lack of detectable significant variation of infection following experimental challenge. Twelve alpacas (158 + 15 days) were randomized to vaccination with Barbervax ® or no treatment. Three doses of Barbervax ® were administered at 3 week intervals and investigators involved in animal monitoring and sample collection were blinded to the groupings. Clinical pathologic parameters were evaluated 7 days before vaccination, and 1 and 2 months post-vaccination. Daily clinical observations were made and specific observations regarding the injection site and rectal temperatures were monitored in each alpaca twice daily for 1 week following vaccination. Fecal egg counts, packed cell volume, and total protein were monitored following challenge with 1500 H. contortus larvae on days 42, 46, and 50. An increase in rectal temperature for a duration of 2 days (range 2-4 days) was observed post-vaccination. Vaccinated alpacas were lethargic for 2-3 days following vaccination; however, they maintained an appetite and no visible or palpable injection site reactions were observed. Following the first vaccination, all animals maintained normal clinical pathologic parameters throughout the study period. The vaccinated animals did develop titers to the H. contortus antigen as measured by ELISA. In conclusion, the Barbervax ® vaccine demonstrated safety in this small group of young, healthy alpacas, but additional studies are required to evaluate the efficacy of the vaccine under field conditions in protecting alpacas against infection with H. contortus. Published by Elsevier B.V.

A hybrid approach to predict the relationship between tablet tensile strength and compaction pressure using analytical powder compression.

PubMed

Persson, Ann-Sofie; Alderborn, Göran

2018-04-01

The objective was to present a hybrid approach to predict the strength-pressure relationship (SPR) of tablets using common compression parameters and a single measurement of tablet tensile strength. Experimental SPR were derived for six pharmaceutical powders with brittle and ductile properties and compared to predicted SPR based on a three-stage approach. The prediction was based on the Kawakita b -1 parameter and the in-die Heckel yield stress, an estimate of maximal tensile strength, and a parameter proportionality factor α. Three values of α were used to investigate the influence of the parameter on the SPR. The experimental SPR could satisfactorily be described by the three stage model, however for sodium bicarbonate the tensile strength plateau could not be observed experimentally. The shape of the predicted SPR was to a minor extent influenced by the Kawakita b -1 but the width of the linear region was highly influenced by α. An increased α increased the width of the linear region and thus also the maximal predicted tablet tensile strength. Furthermore, the correspondence between experimental and predicted SPR was influenced by the α value and satisfactory predictions were in general obtained for α = 4.1 indicating the predictive potential of the hybrid approach. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Assessment of reduced-order unscented Kalman filter for parameter identification in 1-dimensional blood flow models using experimental data.

PubMed

Caiazzo, A; Caforio, Federica; Montecinos, Gino; Muller, Lucas O; Blanco, Pablo J; Toro, Eluterio F

2016-10-25

This work presents a detailed investigation of a parameter estimation approach on the basis of the reduced-order unscented Kalman filter (ROUKF) in the context of 1-dimensional blood flow models. In particular, the main aims of this study are (1) to investigate the effects of using real measurements versus synthetic data for the estimation procedure (i.e., numerical results of the same in silico model, perturbed with noise) and (2) to identify potential difficulties and limitations of the approach in clinically realistic applications to assess the applicability of the filter to such setups. For these purposes, the present numerical study is based on a recently published in vitro model of the arterial network, for which experimental flow and pressure measurements are available at few selected locations. To mimic clinically relevant situations, we focus on the estimation of terminal resistances and arterial wall parameters related to vessel mechanics (Young's modulus and wall thickness) using few experimental observations (at most a single pressure or flow measurement per vessel). In all cases, we first perform a theoretical identifiability analysis on the basis of the generalized sensitivity function, comparing then the results owith the ROUKF, using either synthetic or experimental data, to results obtained using reference parameters and to available measurements. Copyright © 2016 John Wiley & Sons, Ltd.

Experimental design based response surface methodology optimization of ultrasonic assisted adsorption of safaranin O by tin sulfide nanoparticle loaded on activated carbon.

PubMed

Roosta, M; Ghaedi, M; Daneshfar, A; Sahraei, R

2014-03-25

In this research, the adsorption rate of safranine O (SO) onto tin sulfide nanoparticle loaded on activated carbon (SnS-NPAC) was accelerated by the ultrasound. SnS-NP-AC was characterized by different techniques such as SEM, XRD and UV-Vis measurements. The present results confirm that the ultrasound assisted adsorption method has remarkable ability to improve the adsorption efficiency. The influence of parameters such as the sonication time, adsorbent dosage, pH and initial SO concentration was examined and evaluated by central composite design (CCD) combined with response surface methodology (RSM) and desirability function (DF). Conducting adsorption experiments at optimal conditions set as 4 min of sonication time, 0.024 g of adsorbent, pH 7 and 18 mg L(-1) SO make admit to achieve high removal percentage (98%) and high adsorption capacity (50.25 mg g(-)(1)). A good agreement between experimental and predicted data in this study was observed. The experimental equilibrium data fitting to Langmuir, Freundlich, Tempkin and Dubinin-Radushkevich models show that the Langmuir model is a good and suitable model for evaluation and the actual behavior of adsorption. Kinetic evaluation of experimental data showed that the adsorption processes followed well pseudo-second-order and intraparticle diffusion models. Copyright © 2013. Published by Elsevier B.V.

Immunohistopathologic demonstration of deleterious effects on growing rat testes of radiofrequency waves emitted from conventional Wi-Fi devices.

PubMed

Atasoy, Halil I; Gunal, Mehmet Y; Atasoy, Pinar; Elgun, Serenay; Bugdayci, Guler

2013-04-01

To investigate effects on rat testes of radiofrequency radiation emitted from indoor Wi-Fi Internet access devices using 802.11.g wireless standards. Ten Wistar albino male rats were divided into experimental and control groups, with five rats per group. Standard wireless gateways communicating at 2.437 GHz were used as radiofrequency wave sources. The experimental group was exposed to radiofrequency energy for 24 h a day for 20 weeks. The rats were sacrificed at the end of the study. Intracardiac blood was sampled for serum 8-hydroxy-2'-deoxyguanosine levels. Testes were removed and examined histologically and immunohistochemically. Testis tissues were analyzed for malondialdehyde levels and prooxidant-antioxidant enzyme activities. We observed significant increases in serum 8-hydroxy-2'-deoxyguanosine levels and 8-hydroxyguanosine staining in the testes of the experimental group indicating DNA damage due to exposure (p < 0.05). We also found decreased levels of catalase and glutathione peroxidase activity in the experimental group, which may have been due to radiofrequency effects on enzyme activity (p < 0.05). These findings raise questions about the safety of radiofrequency exposure from Wi-Fi Internet access devices for growing organisms of reproductive age, with a potential effect on both fertility and the integrity of germ cells. Copyright © 2012 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

Modeling and Experiments with Carbon Nanotubes for Applications in High Performance Circuits

DTIC Science & Technology

2017-04-06

purchased and installed for experimental characterization of atomic layer deposited graphene on different substrates for radiation-hardened studies...72 3.6 Experimental Research in Graphene for Radiation Hardened Devices……………..73 4 Recommendations...physics for analysis and design of integrated circuits. The developed model is verified from published experimental data. Basic logic gates in

The Innate Immune Receptor CD14 Mediates Lymphocyte Migration in EAE.

PubMed

Halmer, Ramona; Davies, Laura; Liu, Yang; Fassbender, Klaus; Walter, Silke

2015-01-01

Multiple sclerosis is the most common autoimmune disease of the central nervous system in young adults and histopathologically characterized by inflammation, demyelination and gliosis. It is considered as a CD4+ T cell-mediated disease, but also a disease-promoting role of the innate immune system has been proposed, based e.g. on the observation that innate immune receptors modulate disease severity of experimental autoimmune encephalomyelitis. Recent studies of our group provided first evidence for a key role of the innate immune LPS receptor (CD14) in pathophysiology of experimental autoimmune encephalomyelitis. CD14-deficient experimental autoimmune encephalomyelitis mice showed increased clinical symptoms and enhanced infiltration of monocytes and neutrophils in brain and spinal cord. In the current study, we further investigated the causes of the disease aggravation by CD14-deficiency and examined T cell activation, also focusing on the costimulatory molecules CTLA-4 and CD28, and T cell migration capacity over the blood brain barrier by FACS analysis, in vitro adhesion and transmigration assays. In the results, we observed a significantly increased migration of CD14-deficient lymphocytes across an endothelial monolayer. In contrast, we did not see any differences in expression levels of TCR/CTLA-4 or TCR/CD28 and lymphocyte adhesion to endothelial cells from CD14-deficient compared to wildtype mice. The results demonstrate an important role of CD14 in migration of lymphocytes, and strengthen the importance of innate immune receptors in adaptive immune disorders, such as multiple sclerosis. © 2015 The Author(s) Published by S. Karger AG, Basel.

Biocompatibility of root filling pastes used in primary teeth.

PubMed

Lima, C C B; Conde Júnior, A M; Rizzo, M S; Moura, R D; Moura, M S; Lima, M D M; Moura, L F A D

2015-05-01

To evaluate the biocompatibility of two pastes designed to fill the root canals of primary teeth. A study group of 54 mice received subcutaneous tissue implants of polyethylene tubes containing CTZ or calcium hydroxide paste or, as a negative control, empty tubes. Biocompatibility was evaluated on days 7, 21 and 63, yielding a total of nine groups of six animals each. Following the experimental intervals, the implant areas were removed and subjected to histologic processing. After the tissues were stained with HE and Masson trichrome, two pathologists performed a histologic analysis of the samples in a blinded manner. Collagen fibre formation, tissue thickness and inflammatory cell infiltration were analysed qualitatively. Quantitative morphometry was performed for the thickness, perimeter length and tissue area of the region in direct contact with the open tube. anova with the Tukey post-test and Kruskal-Wallis analysis followed by Dunn's post-test, with significance established as P < 0.05, were used for data analysis. At 7 days, all groups had severe acute inflammatory infiltrates. Inflammation was reduced at 21 days in the CTZ paste group. Mild chronic inflammatory infiltrates were observed after 63 days in the CTZ and Ca(OH)2 paste groups; these groups also showed a significant decrease in collagen fibre density (P < 0.05), which was not observed in the control group. The average tissue thickness, perimeter length and area in contact with the tube decreased during the experimental periods in all groups. The CTZ and calcium hydroxide pastes demonstrated biocompatibility with subcutaneous tissue in this experimental model. © 2014 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Effects of sugammadex on the prevention of postoperative peritoneal adhesions.

PubMed

Şahin, Hasan; Toman, Hüseyin; Kiraz, Hasan Ali; Şimşek, Tuncer; Erbaş, Mesut; Özkul, Faruk; Arık, Muhammet Kasım; Hancı, Volkan

2015-09-01

Many materials and techniques have been used to prevent and repair intra-abdominal adhesions, but an effective solution has not been found. The aim of this study is to research the effect of sugammadex on intra-abdominal adhesions in an experimentally induced intra-abdominal adhesion model. Twenty-four female Wistar albino rats were included in the study. The experimental animals were randomly divided into three groups: the sugammadex group (Group SX, n = 8), the control group (Group C, n = 8), and the sham group (Group S, n = 8). After starvation for 1 night, the rats were injected with a 50 mg/kg intramuscular dose of ketamine and a 5 mg/kg intramuscular dose of xylazine for anesthesia. The rats in the SX group were given 3 mL sugammadex into the peritoneal cavity, while rats in the control group were given 3 mL 0.9% sodium chloride. In the sham group, the peritoneal cavity was opened, but no chemicals were administered. All rats were sacrificed on the 10(th) postoperative day. The adhesions were staged as 0, 1, 2, and 3 according to Evans et al.'s model. Our evaluation of macroscopic adhesion intensity found statistically significant differences between the groups. The sugammadex group was observed to have fewer adhesions in a statistically significant manner compared with the control group (p < 0.05). In our experimental intra-abdominal adhesion model in rats, we observed that sugammadex prevented postoperative intra-abdominal adhesions. Copyright © 2015. Published by Elsevier Taiwan.

The power of competence support: The impact of coaches and athlete leaders on intrinsic motivation and performance.

PubMed

Fransen, K; Boen, F; Vansteenkiste, M; Mertens, N; Vande Broek, G

2018-02-01

Grounded in the Cognitive Evaluation Theory, a mini-theory of Self-Determination Theory, this experimental field study sought to examine the impact of competence support of both coaches and athlete leaders on athletes' competence satisfaction, intrinsic motivation, and subjective as well as objective performance. Male basketball players (N = 120) were allocated to groups of 5 players. These groups were then randomly assigned to a control group or to 1 of 3 experimental conditions. In these experimental conditions, either the coach, the athlete leader, or both provided motivational feedback to their team. The provision of motivational feedback by either the coach or the athlete leader was sufficient to increase athletes' competence satisfaction, intrinsic motivation, and objective performance (i.e., enhanced execution time without a decrease in scoring percentage) relative to the control group. Interestingly, when both the coach and the athlete leader provided competence support, a surplus effect was observed on objective performance compared with when only the coach provided competence support. Furthermore, structural equation modeling revealed that players' competence satisfaction mediated the relationship between the provided competence support and players' intrinsic motivation, while a direct effect was observed on objective performance. In conclusion, the study findings indicate that also athlete leaders can adopt a motivating role, and that by doing so, their impact is as strong as the impact of the coach. Both coaches and athlete leaders can thus boost athletes' objective performance and foster competence satisfaction, with the latter resulting in increased intrinsic motivation. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Epidermal Homeostasis and Radiation Responses in a Multiscale Tissue Modeling Framework

NASA Technical Reports Server (NTRS)

Hu, Shaowen; Cucinotta, Francis A.

2013-01-01

The surface of skin is lined with several thin layers of epithelial cells that are maintained throughout life time by a small population of stem cells. High dose radiation exposures could injure and deplete the underlying proliferative cells and induce cutaneous radiation syndrome. In this work we propose a multiscale computational model for skin epidermal dynamics that links phenomena occurring at the subcellular, cellular, and tissue levels of organization, to simulate the experimental data of the radiation response of swine epidermis, which is closely similar to human epidermis. Incorporating experimentally measured histological and cell kinetic parameters, we obtain results of population kinetics and proliferation indexes comparable to observations in unirradiated and acutely irradiated swine experiments. At the sub-cellular level, several recently published Wnt signaling controlled cell-cycle models are applied and the roles of key components and parameters are analyzed. Based on our simulation results, we demonstrate that a moderate increase of proliferation rate for the survival proliferative cells is sufficient to fully repopulate the area denuded by high dose radiation, as long as the integrity of underlying basement membrane is maintained. Our work highlights the importance of considering proliferation kinetics as well as the spatial organization of tissues when conducting in vivo investigations of radiation responses. This integrated model allow us to test the validity of several basic biological rules at the cellular level and sub-cellular mechanisms by qualitatively comparing simulation results with published research, and enhance our understanding of the pathophysiological effects of ionizing radiation on skin.

[Quality of clinical studies published in the RBGO over one decade (1999-2009): methodological and ethical aspects and statistical procedures].

PubMed

de Sá, Joceline Cássia Ferezini; Marini, Gabriela; Gelaleti, Rafael Bottaro; da Silva, João Batista; de Azevedo, George Gantas; Rudge, Marilza Vieira Cunha

2013-11-01

To evaluate the methodological and statistical design evolution of the publications in the Brazilian Journal of Gynecology and Obstetrics (RBGO) from resolution 196/96. A review of 133 articles published in 1999 (65) and 2009 (68) was performed by two independent reviewers with training in clinical epidemiology and methodology of scientific research. We included all original clinical articles, case and series reports and excluded editorials, letters to the editor, systematic reviews, experimental studies, opinion articles, besides abstracts of theses and dissertations. Characteristics related to the methodological quality of the studies were analyzed in each article using a checklist that evaluated two criteria: methodological aspects and statistical procedures. We used descriptive statistics and the χ2 test for comparison of the two years. There was a difference between 1999 and 2009 regarding the study and statistical design, with more accuracy in the procedures and the use of more robust tests between 1999 and 2009. In RBGO, we observed an evolution in the methods of published articles and a more in-depth use of the statistical analyses, with more sophisticated tests such as regression and multilevel analyses, which are essential techniques for the knowledge and planning of health interventions, leading to fewer interpretation errors.

A bias-adjusted evidence synthesis of RCT and observational data: the case of total hip replacement.

PubMed

Schnell-Inderst, Petra; Iglesias, Cynthia P; Arvandi, Marjan; Ciani, Oriana; Matteucci Gothe, Raffaella; Peters, Jaime; Blom, Ashley W; Taylor, Rod S; Siebert, Uwe

2017-02-01

Evaluation of clinical effectiveness of medical devices differs in some aspects from the evaluation of pharmaceuticals. One of the main challenges identified is lack of robust evidence and a will to make use of experimental and observational studies (OSs) in quantitative evidence synthesis accounting for internal and external biases. Using a case study of total hip replacement to compare the risk of revision of cemented and uncemented implant fixation modalities, we pooled treatment effect estimates from OS and RCTs, and simplified existing methods for bias-adjusted evidence synthesis to enhance practical application. We performed an elicitation exercise using methodological and clinical experts to determine the strength of beliefs about the magnitude of internal and external bias affecting estimates of treatment effect. We incorporated the bias-adjusted treatment effects into a generalized evidence synthesis, calculating both frequentist and Bayesian statistical models. We estimated relative risks as summary effect estimates with 95% confidence/credibility intervals to capture uncertainty. When we compared alternative approaches to synthesizing evidence, we found that the pooled effect size strongly depended on the inclusion of observational data as well as on the use bias-adjusted estimates. We demonstrated the feasibility of using observational studies in meta-analyses to complement RCTs and incorporate evidence from a wider spectrum of clinically relevant studies and healthcare settings. To ensure internal validity, OS data require sufficient correction for confounding and selection bias, either through study design and primary analysis, or by applying post-hoc bias adjustments to the results. © 2017 The Authors. Health Economics published by John Wiley & Sons, Ltd. © 2017 The Authors. Health Economics published by John Wiley & Sons, Ltd.

The research evidence published in high impact nursing journals between 2000 and 2006: a quantitative content analysis.

PubMed

Mantzoukas, Stefanos

2009-04-01

Evidence-based practice has become an imperative for efficient, effective and safe practice. Furthermore, evidences emerging from published research are considered as valid knowledge sources to guiding practice. The aim of this paper is to review all research articles published in the top 10 general nursing journals for the years 2000-2006 to identify the methodologies used, the types of evidence these studies produced and the issues upon which they endeavored. Quantitative content analysis was implemented to study all published research papers of the top 10 general nursing journals for the years 2000-2006. The top 10 general nursing journals were included in the study. The abstracts of all research articles were analysed with regards the methodologies of enquiry, the types of evidence produced and the issues of study they endeavored upon. Percentages were developed as to enable conclusions to be drawn. The results for the category methodologies used were 7% experimental, 6% quasi-experimental, 39% non-experimental, 2% ethnographical studies, 7% phenomenological, 4% grounded theory, 1% action research, 1% case study, 15% unspecified, 5.5% other, 0.5% meta-synthesis, 2% meta-analysis, 5% literature reviews and 3% secondary analysis. For the category types of evidence were 4% hypothesis/theory testing, 11% evaluative, 5% comparative, 2% correlational, 46% descriptive, 5% interpretative and 27% exploratory. For the category issues of study were 45% practice/clinical, 8% educational, 11% professional, 3% spiritual/ethical/metaphysical, 26% health promotion and 7% managerial/policy. Published studies can provide adequate evidences for practice if nursing journals conceptualise evidence emerging from non-experimental and qualitative studies as relevant types of evidences for practice and develop appropriate mechanisms for assessing their validity. Also, nursing journals need to increase and encourage the publication of studies that implement RCT methodology, systematic reviews, meta-synthesis and meta-analysis methodologies. Finally, nursing journals need to encourage more high quality research evidence that derive from interpretative, theory testing and evaluative types of studies that are practice relevant.

Evaluation of possible head injuries ensuing a cricket ball impact.

PubMed

Mohotti, Damith; Fernando, P L N; Zaghloul, Amir

2018-05-01

The aim of this research is to study the behaviour of a human head during the event of an impact of a cricket ball. While many recent incidents were reported in relation to head injuries caused by the impact of cricket balls, there is no clear information available in the published literature about the possible threat levels and the protection level of the current protective equipment. This research investigates the effects of an impact of a cricket ball on a human head and the level of protection offered by the existing standard cricket helmet. An experimental program was carried out to measure the localised pressure caused by the impact of standard cricket balls. The balls were directed at a speed of 110 km/h on a 3D printed head model, with and without a standard cricket helmet. Numerical simulations were carried out using advanced finite element package LS-DYNA to validate the experimental results. The experimental and numerical results showed approximately a 60% reduction in the pressure on the head model when the helmet was used. Both frontal and side impact resulted in head acceleration values in the range of 225-250 g at a ball speed of 110 km/h. There was a 36% reduction observed in the peak acceleration of the brain when wearing a helmet. Furthermore, numerical simulations showed a 67% reduction in the force on the skull and a 95% reduction in the skull internal energy when introducing the helmet. (1) Upon impact, high localised pressure could cause concussion for a player without helmet. (2) When a helmet was used, the acceleration of the brain observed in the numerical results was at non-critical levels according to existing standards. (3) A significant increase in the threat levels was observed for a player without helmet, based on force, pressure, acceleration and energy criteria, which resulted in recommending the compulsory use of the cricket helmet. (4) Numerical results showed a good correlation with experimental results and hence, the numerical technique used in this study can be recommended for future applications. Copyright © 2018 Elsevier B.V. All rights reserved.

Proteinase-activated receptor 2 modulates OA-related pain, cartilage and bone pathology.

PubMed

Huesa, Carmen; Ortiz, Ana C; Dunning, Lynette; McGavin, Laura; Bennett, Louise; McIntosh, Kathryn; Crilly, Anne; Kurowska-Stolarska, Mariola; Plevin, Robin; van 't Hof, Rob J; Rowan, Andrew D; McInnes, Iain B; Goodyear, Carl S; Lockhart, John C; Ferrell, William R

2016-11-01

Proteinase-activated receptor 2 (PAR2) deficiency protects against cartilage degradation in experimental osteoarthritis (OA). The wider impact of this pathway upon OA-associated pathologies such as osteophyte formation and pain is unknown. Herein, we investigated early temporal bone and cartilage changes in experimental OA in order to further elucidate the role of PAR2 in OA pathogenesis. OA was induced in wild-type (WT) and PAR2-deficient (PAR2 -/- ) mice by destabilisation of the medial meniscus (DMM). Inflammation, cartilage degradation and bone changes were monitored using histology and microCT. In gene rescue experiments, PAR2 -/- mice were intra-articularly injected with human PAR2 (hPAR2)-expressing adenovirus. Dynamic weight bearing was used as a surrogate of OA-related pain. Osteophytes formed within 7 days post-DMM in WT mice but osteosclerosis was only evident from 14 days post induction. Importantly, PAR2 was expressed in the proliferative/hypertrophic chondrocytes present within osteophytes. In PAR2 -/- mice, osteophytes developed significantly less frequently but, when present, were smaller and of greater density; no osteosclerosis was observed in these mice up to day 28. The pattern of weight bearing was altered in PAR2 -/- mice, suggesting reduced pain perception. The expression of hPAR2 in PAR2 -/- mice recapitulated osteophyte formation and cartilage damage similar to that observed in WT mice. However, osteosclerosis was absent, consistent with lack of hPAR2 expression in subchondral bone. This study clearly demonstrates PAR2 plays a critical role, via chondrocytes, in osteophyte development and subchondral bone changes, which occur prior to PAR2-mediated cartilage damage. The latter likely occurs independently of OA-related bone changes. 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/.

The Fraser Experimental Forest, Colorado

Treesearch

Robert R. Alexander; Ross K. Watkins

1977-01-01

This report provides a general overview of work done on the Fraser Experimental Forest. It replaces Station Paper No.8, published in 1952 and revised by L. D. Love in 1960. Included are descriptions of physical features and resource values, and highlights of past and current research programs.

Elaphomyces species (Elasphomycetaceae, Eurotiales) from Bartlett Experimental Forest, New Hampshire, USA

Treesearch

Michael A. Castellano; Ryan B. Stephens

2017-01-01

We describe five new species of Elaphomyces from Bartlett Experimental Forest, New Hampshire, USA (E. americanus, E. bartlettii, E. macrosporus, E. oreoides, and E. remickii) and revise the description of a sixth previously published species (E. verruculosus). Of the five new species,...

The curious rise and fall of experimental psychology in "Mind".

PubMed

Green, Christopher D

2009-01-01

The journal "Mind" is now a wholly philosophical journal. At the time of its founding, in 1876, however, its mission was rather different in character. Its aim was to discover whether scientific psychology was a truly viable enterprise and, if so, what its boundaries with philosophy, with other scientific disciplines, and with the earlier generation of discredited attempts at "scientific" studies of the mind (e.g. phrenology, mesmerism) might be. Although at first "Mind" published mostly philosophical pieces and literature reviews, by the mid-1880s it was publishing primary experimental research, mostly by American psychologists who as yet had few outlets of their own. For a time it was the leading journal of experimental psychology in the English-speaking world. As the international competition among scientific and scholarly journals intensified in the 1890s, however, "Mind" started to lose its share of experimental contributions, and with the editorial takeover of the journal of George Stout in 1892, the journal soon became one dedicated purely to philosophy.

[Laboratory animals and official Mexican norms (NOM-062-ZOO-1999)].

PubMed

de Aluja, Aline S

2002-01-01

This article concerns animal experimentation and official Mexican norm Nom 0062-Zoo-1999 entitled Technical specifications for the production, care and use of laboratory animals. The history of animal experimentation is briefly resumed. During the nineteenth century, doubts arose as to the right to expose animals to experimental procedures that frequently cause pain and suffering. The first law which protected animals against cruelty was passed in Great Britain in 1876; subsequently, other nations approved similar legislation. During the second part of the twentieth century, opposition to animal experimentation grew. Other groups, mainly scientists and pharmaceutical concerns, defended the right to use animals in research. New knowledge concerning the neurophysiology, cognitive capacity, and the animal faculty to experience pain is briefly mentioned. Guidelines on care and use of animals used in research published in several countries are listed. Finally, the recently published Mexican legislation (Norm) referring to production, care and use of laboratory animals is discussed and its benefits are stressed.

A review of data sharing statements in observational studies published in the BMJ: A cross-sectional study

PubMed Central

McDonald, Laura; Schultze, Anna; Simpson, Alex; Graham, Sophie; Wasiak, Radek; Ramagopalan, Sreeram V.

2017-01-01

In order to understand the current state of data sharing in observational research studies, we reviewed data sharing statements of observational studies published in a general medical journal, the British Medical Journal. We found that the majority (63%) of observational studies published between 2015 and 2017 included a statement that implied that data used in the study could not be shared. If the findings of our exploratory study are confirmed, room for improvement in the sharing of real-world or observational research data exists. PMID:29167735

Assessing the scientific research productivity of a leading toxicology journal: A case study of Human & Experimental Toxicology from 2003 to 2012

PubMed Central

Al-Jabi, Samah W; Sweileh, Waleed M; Awang, Rahmat

2014-01-01

Background: Bibliometric studies are increasingly being used for research assessments. Bibliometric indicators involve the application of statistical methods to scientific publications to obtain the bibliographics for each journal. The main objective of this study was to conduct a bibliometric evaluation of Human & Experimental Toxicology retrieved from the Scopus database. Methods: This study obtained data from Scopus published from 1 January 2003 till 31 December 2012. The keywords entered in Scopus to accomplish the objective of this study were ‘Human’, ‘Experimental’ and ‘Toxicology’ as ‘Source Title’. Research productivity was evaluated based on a methodology developed and used in other bibliometric studies by analysing (a) total and trends in Human & Experimental Toxicology contributions in research between 2003 and 2012; (b) Human & Experimental Toxicology authorship patterns and productivity; (c) collaboration patterns; and (d) the citations received by the publications. Results: There were 1229 research articles published in Human & Experimental Toxicology. Of the articles included, 947 (77.1%) were original articles and 104 (8.5%) were review articles. The Hirsch-index of the retrieved documents was 35. The largest number of publications in Human & Experimental Toxicology was from the United States (19.6%), followed by India (12.8%) and Turkey (10.9%). The total number of citations was 9119, with a median (interquartile range) of 3 (1–9) in 6797 documents. The highest median (interquartile range) number of citations was 8 (2.7–12.7) for France, followed by 7.5 (2–22.5) for Iran and 6 (3–13.5) for the United Kingdom. The country most often citing articles that were published in Human & Experimental Toxicology was the United States, which made citations in 1508 documents, followed by India with citations in 792 documents. Conclusion: The documents in Human & Experimental Toxicology focus principally on original data, with very few review articles. Review articles tend to have higher citation rates than original articles, and hence, the editors and authors of Human & Experimental Toxicology might usefully promote the submission of reviews in the future to improve the impact of the journal. PMID:26770709

A multiscale strength model for tantalum over an extended range of strain rates

NASA Astrophysics Data System (ADS)

Barton, N. R.; Rhee, M.

2013-09-01

A strength model for tantalum is developed and exercised across a range of conditions relevant to various types of experimental observations. The model is based on previous multiscale modeling work combined with experimental observations. As such, the model's parameterization includes a hybrid of quantities that arise directly from predictive sub-scale physics models and quantities that are adjusted to align the model with experimental observations. Given current computing and experimental limitations, the response regions for sub-scale physics simulations and detailed experimental observations have been largely disjoint. In formulating the new model and presenting results here, attention is paid to integrated experimental observations that probe strength response at the elevated strain rates where a previous version of the model has generally been successful in predicting experimental data [Barton et al., J. Appl. Phys. 109(7), 073501 (2011)].

Ultrasound-microbubble mediated cavitation of plant cells: effects on morphology and viability.

PubMed

Qin, Peng; Xu, Lin; Zhong, Wenjing; Yu, Alfred C H

2012-06-01

The interaction between ultrasound pulses and microbubbles is known to generate acoustic cavitation that may puncture biological cells. This work presents new experimental findings on the bioeffects of ultrasound-microbubble mediated cavitation in plant cells with emphasis on direct observations of morphological impact and analysis of viability trends in tobacco BY-2 cells that are widely studied in higher plant physiology. The tobacco cell suspensions were exposed to 1 MHz ultrasound pulses in the presence of 1% v/v microbubbles (10% duty cycle; 1 kHz pulse repetition frequency; 70 mm between probe and cells; 1-min exposure time). Few bioeffects were observed at low peak negative pressures (<0.4 MPa) where stable cavitation presumably occurred. In contrast, at 0.9 MPa peak negative pressure (with more inertial cavitation activities according to our passive cavitation detection results), random pores were found on tobacco cell wall (observed via scanning electron microscopy) and enhanced exogenous uptake into the cytoplasm was evident (noted in our fluorescein isothiocyanate dextran uptake analysis). Also, instant lysis was observed in 23.4% of cells (found using trypan blue staining) and programmed cell death was seen in 23.3% of population after 12 h (determined by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling [TUNEL]). These bioeffects generally correspond in trend with those for mammalian cells. This raises the possibility of developing ultrasound-microbubble mediated cavitation into a targeted gene transfection paradigm for plant cells and, conversely, adopting plant cells as experimental test-beds for sonoporation-based gene therapy in mammalian cells. Copyright © 2012 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Big Bang, inflation, standard Physics… and the potentialities of new Physics and alternative cosmologies. Present statuts of observational and experimental Cosmology. Open questions and potentialities of alternative cosmologies

NASA Astrophysics Data System (ADS)

Gonzalez-Mestres, Luis

2016-11-01

A year ago, we wrote [1] that the field of Cosmology was undergoing a positive and constructive crisis. The possible development of more direct links between the Mathematical Physics aspects of cosmological patterns and the interpretation of experimental and observational results was particularly emphasized. Controversies on inflation are not really new, but in any case inflation is not required in pre-Big Bang models and the validity of the standard Big Bang + inflation + ΛCDM pattern has not by now been demonstrated by data. Planck has even explicitly reported the existence of "anomalies". Remembering the far-reaching work of Yoichiro Nambu published in 1959-61, it seems legitimate to underline the need for a cross-disciplinary approach in the presence of deep, unsolved theoretical problems concerning new domains of matter properties and of the physical world. The physics of a possible preonic vacuum and the associated cosmology constitute one of these domains. If the vacuum is made of superluminal preons (superbradyons), and if standard particles are vacuum excitations, how to build a suitable theory to describe the internal structure of such a vacuum at both local and cosmic level? Experimental programs (South Pole, Atacama, AUGER, Telescope Array…) and observational ones (Planck, JEM-EUSO…) devoted to the study of cosmic microwave background radiation (CMB) and of ultra-high energy cosmic rays (UHECR) are crucial to elucidate such theoretical interrogations and guide new phenomenological developments. Together with a brief review of the observational and experimental situation, we also examine the main present theoretical and phenomenological problems and point out the role new physics and alternative cosmologies can potentially play. The need for data analyses less focused a priori on the standard models of Particle Physics and Cosmology is emphasized in this discussion. An example of a new approach to both fields is provided by the pre-Big Bang pattern based on a physical vacuum made of superbradyons with the spinorial space-time (SST) geometry we introduced in 1996-97. In particular, the SST automatically generates a local privileged space direction (PSD) for earch comoving observer and such a signature may have been confirmed by Planck data. Both superluminal preons and the existence of the PSD would have strong cosmological implications. Planck 2016 results will be particularly relevant as a step in the study of present open questions. This paper is dedicated to the memory of Yoichiro Nambu

The rule of declining adaptability in microbial evolution experiments

PubMed Central

Couce, Alejandro; Tenaillon, Olivier A.

2015-01-01

One of the most recurrent observations after two decades of microbial evolution experiments regards the dynamics of fitness change. In a given environment, low-fitness genotypes are recurrently observed to adapt faster than their more fit counterparts. Since adaptation is the main macroscopic outcome of Darwinian evolution, studying its patterns of change could potentially provide insight into key issues of evolutionary theory, from fixation dynamics to the genetic architecture of organisms. Here, we re-analyze several published datasets from experimental evolution with microbes and show that, despite large differences in the origin of the data, a pattern of inverse dependence of adaptability with fitness clearly emerges. In quantitative terms, it is remarkable to observe little if any degree of idiosyncrasy across systems as diverse as virus, bacteria and yeast. The universality of this phenomenon suggests that its emergence might be understood from general principles, giving rise to the exciting prospect that evolution might be statistically predictable at the macroscopic level. We discuss these possibilities in the light of the various theories of adaptation that have been proposed and delineate future directions of research. PMID:25815007

Magnetic resonance spectroscopic analysis of neurometabolite changes in the developing rat brain at 7T.

PubMed

Ramu, Jaivijay; Konak, Tetyana; Liachenko, Serguei

2016-11-15

We utilized proton magnetic resonance spectroscopy to evaluate the metabolic profile of the hippocampus and anterior cingulate cortex of the developing rat brain from postnatal days 14-70. Measured metabolite concentrations were modeled using linear, exponential, or logarithmic functions and the time point at which the data reached plateau (i.e. when the portion of the data could be fit to horizontal line) was estimated and was interpreted as the time when the brain has reached maturity with respect to that metabolite. N-acetyl-aspartate and myo-inositol increased within the observed period. Gluthathione did not vary significantly, while taurine decreased initially and then stabilized. Phosphocreatine and total creatine had a tendency to increase towards the end of the experiment. Some differences between our data and the published literature were observed in the concentrations and dynamics of phosphocreatine, myo-inositol, and GABA in the hippocampus and creatine, GABA, glutamine, choline and N-acetyl-aspartate in the cortex. Such differences may be attributed to experimental conditions, analysis approaches and animal species. The latter is supported by differences between in-house rat colony and rats from Charles River Labs. Spectroscopy provides a valuable tool for non-invasive brain neurochemical profiling for use in developmental neurobiology research. Special attention needs to be paid to important sources of variation like animal strain and commercial source. Published by Elsevier B.V.

Partitioning of Ni, Co and V between Spinel-Structured Oxides and Silicate Melts: Importance of Spinel Composition

NASA Technical Reports Server (NTRS)

Righter, K.; Leeman, W. P.; Hervig, R. L.

2006-01-01

Partitioning of Ni, Co and V between Cr-rich spinels and basaltic melt has been studied experimentally between 1150 and 1325 C, and at controlled oxygen fugacity from the Co-CoO buffer to slightly above the hematite magnetite buffer. These new results, together with new Ni, Co and V analyses of experimental run products from Leeman [Leeman, W.P., 1974. Experimental determination of the partitioning of divalent cations between olivine and basaltic liquid, Pt. II. PhD thesis, Univ. Oregon, 231 - 337.], show that experimentally determined spinel melt partition coefficients (D) are dependent upon temperature (T), oxygen fugacity (fO2) and spinel composition. In particular, partition coefficients determined on doped systems are higher than those in natural (undoped) systems, perhaps due to changing activity coefficients over the composition range defined by the experimental data. Using our new results and published runs (n =85), we obtain a multilinear regression equation that predicts experimental D(V) values as a function of T, fO2, concentration of V in melt and spinel composition. This equation allows prediction of D(V) spinel/melt values for natural mafic liquids at relevant crystallization conditions. Similarly, D(Ni) and D(Co) values can be inferred from our experiments at redox conditions approaching the QFM buffer, temperatures of 1150 to 1250 C and spinel composition (early Cr-bearing and later Ti-magnetite) appropriate for basic magma differentiation. When coupled with major element modelling of liquid lines of descent, these values (D(Ni) sp/melt=10 and D(Co) sp/melt=5) closely reproduce the compositional variation observed in komatiite, mid-ocean ridge basalt (MORB), ocean island basalt (OIB) and basalt to rhyolite suites.

The state of RT-quantitative PCR: firsthand observations of implementation of minimum information for the publication of quantitative real-time PCR experiments (MIQE).

PubMed

Taylor, Sean C; Mrkusich, Eli M

2014-01-01

In the past decade, the techniques of quantitative PCR (qPCR) and reverse transcription (RT)-qPCR have become accessible to virtually all research labs, producing valuable data for peer-reviewed publications and supporting exciting research conclusions. However, the experimental design and validation processes applied to the associated projects are the result of historical biases adopted by individual labs that have evolved and changed since the inception of the techniques and associated technologies. This has resulted in wide variability in the quality, reproducibility and interpretability of published data as a direct result of how each lab has designed their RT-qPCR experiments. The 'minimum information for the publication of quantitative real-time PCR experiments' (MIQE) was published to provide the scientific community with a consistent workflow and key considerations to perform qPCR experiments. We use specific examples to highlight the serious negative ramifications for data quality when the MIQE guidelines are not applied and include a summary of good and poor practices for RT-qPCR. © 2013 S. Karger AG, Basel.

Magnetospheric Radio Tomography: Observables, Algorithms, and Experimental Analysis

NASA Technical Reports Server (NTRS)

Cummer, Steven

2005-01-01

This grant supported research towards developing magnetospheric electron density and magnetic field remote sensing techniques via multistatic radio propagation and tomographic image reconstruction. This work was motivated by the need to better develop the basic technique of magnetospheric radio tomography, which holds substantial promise as a technology uniquely capable of imaging magnetic field and electron density in the magnetosphere on large scales with rapid cadence. Such images would provide an unprecedented and needed view into magnetospheric processes. By highlighting the systems-level interconnectedness of different regions, our understanding of space weather processes and ability to predict them would be dramatically enhanced. Three peer-reviewed publications and 5 conference presentations have resulted from this work, which supported 1 PhD student and 1 postdoctoral researcher. One more paper is in progress and will be submitted shortly. Because the main results of this research have been published or are soon to be published in refereed journal articles listed in the reference section of this document, we provide here an overview of the research and accomplishments without describing all of the details that are contained in the articles.

Computational characterization of fracture healing under reduced gravity loading conditions.

PubMed

Gadomski, Benjamin C; Lerner, Zachary F; Browning, Raymond C; Easley, Jeremiah T; Palmer, Ross H; Puttlitz, Christian M

2016-07-01

The literature is deficient with regard to how the localized mechanical environment of skeletal tissue is altered during reduced gravitational loading and how these alterations affect fracture healing. Thus, a finite element model of the ovine hindlimb was created to characterize the local mechanical environment responsible for the inhibited fracture healing observed under experimental simulated hypogravity conditions. Following convergence and verification studies, hydrostatic pressure and strain within a diaphyseal fracture of the metatarsus were evaluated for models under both 1 and 0.25 g loading environments and compared to results of a related in vivo study. Results of the study suggest that reductions in hydrostatic pressure and strain of the healing fracture for animals exposed to reduced gravitational loading conditions contributed to an inhibited healing process, with animals exposed to the simulated hypogravity environment subsequently initiating an intramembranous bone formation process rather than the typical endochondral ossification healing process experienced by animals healing in a 1 g gravitational environment. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1206-1215, 2016. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Simulation of Low-Intensity Ultrasound Propagating in a Beagle Dog Dentoalveolar Structure to Investigate the Relations between Ultrasonic Parameters and Cementum Regeneration.

PubMed

Vafaeian, Behzad; Al-Daghreer, Saleh; El-Rich, Marwan; Adeeb, Samer; El-Bialy, Tarek

2015-08-01

The therapeutic effect of low-intensity pulsed ultrasound on orthodontically induced inflammatory root resorption is believed to be brought about through mechanical signals induced by the low-intensity pulsed ultrasound. However, the stimulatory mechanism triggering dental cell response has not been clearly identified yet. The aim of this study was to evaluate possible relations between the amounts of new cementum regeneration and ultrasonic parameters such as pressure amplitude and time-averaged energy density. We used the finite-element method to simulate the previously published experiment on ultrasonic wave propagation in the dentoalveolar structure of beagle dogs. Qualitative relations between the thickness of the regenerated cementum in the experiment and the ultrasonic parameters were observed. Our results indicated that the areas of the root surface with greater ultrasonic pressure were associated with larger amounts of cementum regeneration. However, the establishment of reliable quantitative correlations between ultrasound parameters and cementum regeneration requires more experimental data and simulations. Copyright © 2015 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Constraints on Europa's Ocean Composition Imposed by Its Surface Composition

NASA Astrophysics Data System (ADS)

Johnson, P. V.; Hodyss, R. P.; Vu, T. H.; Choukroun, M.

2017-12-01

Of the non-terrestrial environments within our Solar System, Europa's global liquid water ocean is arguably the most likely to be habitable. As such, understanding the habitability of Europa's ocean is of great interest to astrobiology and is the focus of missions currently being considered for further exploration of Europa. However, direct analysis of the ocean is unlikely in the foreseeable future. As such, our best means of constraining the subsurface ocean composition and its subsequent habitability currently is by further study of Europa's surface chemical composition. Recently, there has been a body of work published that looks at the chemistry of frozen brines representing putative ocean compositions. Here we take a simplified model of a four ionic component (Na, Mg, SO4, Cl) solution and map out what minerals are formed upon freezing as a function of relative ionic concentration, pH, etc. A `flow-chart' of the freezing sequence was developed based on both published and recently acquired experimental results. In performing this exercise, we are able to begin making meaningful links between observations of the surface chemistry and the chemical environment of the internal ocean.

Persuasion to use personal protective equipment in constructing subway stations: application of social marketing.

PubMed

Shamsi, Mahmoud; Pariani, Abbas; Shams, Mohsen; Soleymani-nejad, Marzieh

2016-04-01

To study the effects of an intervention based on social marketing to persuade workers to use personal protective equipment (PPE) in constructing subway stations in Isfahan, Iran. This was a quasi-experimental study. Two stations were selected as intervention and control groups. Intervention was designed based on results of a formative research. A free package containing a safety helmet with a tailored message affixed to it, mask and gloves and an educational pamphlet was delivered to the intervention group. After 6 weeks, behaviours in the intervention and control stations were measured using an observational checklist. After the intervention, the percentage of workers who used PPE at the intervention station increased significantly. OR for helmet and mask usage was 7.009 and 2.235, respectively, in the intervention group. Social marketing can be used to persuade workers to use PPE in the workplace. 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/

[Relationship between the prone position and achieving head control at 3 months].

PubMed

Pérez-Machado, J L; Rodríguez-Fuentes, G

2013-10-01

Owing to the significant increase of mild motor delays and the strong intolerance of infants to be placed on prone position observed in the Physiotherapy Unit of the Maternal and Children's University Hospital of the Canaries (HUMIC), a study was conducted to determine whether positioning infants in the prone position while awake affected the achievement and quality of head control at three months. A prospective comparative practice-based study of a representative sample of 67 healthy infants born in the HUMIC, and divided into an experimental group (n = 35) and control group (n = 32). The Alberta Infant Motor Scale (AIMS) and a parent questionnaire were used as measurement tools. The intervention consisted of regular home visits to the experimental group (from the first to the third month). The two groups were evaluated in their homes at the end of 3 months. The differences in mean raw score of the AIMS at 3 months were, 16.26 in the experimental group and 10.38 in control group (P<.001). The percentile mean was 94 in the experimental group, and less than 50 (42) in the control group. All of the experimental group babies achieved the head control, with only 8 in the control group (25%). The significant findings suggest a direct relationship between the time spent in the prone position when the baby is awake and the achievement of head control at three months. Copyright © 2012 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.

Histomorphometric study of the periodontal ligament in the initial period of orthodontic movement in Wistar rats with induced allergic asthma.

PubMed

Machado, Cristiane Correia Pereira; Nojima, Matilde da Cunha Gonçalves; Rodrigues e Silva, Patrícia Machado; Mandarim-de-Lacerda, Carlos Alberto

2012-09-01

Asthma is a common systemic disease occurring in infancy and adolescence, time periods that could encompass orthodontic treatment. Asthma is an inflammatory disease; therefore, it might interfere with orthodontic tooth movement. The purpose of the study was to analyze the histomorphologic aspects of the periodontal ligament of asthmatic Wistar rats in the initial period of orthodontic movement. Thirty-two Wistar rats were divided into 4 groups: 2 control groups consisting of rats without induced allergic asthma, and 2 experimental groups consisting of rats with induced allergic asthma. The animals of the first control and experimental groups did not receive orthodontic forces, whereas those in the second control and experimental groups were subjected to mesial movement of the maxillary left first molar for 3 days. The samples were prepared for histomorphometric analysis of the periodontal ligament. The area of the periodontal ligament was calculated as a function of root length in the cervical and apical regions of the distal face of the maxillary first molar mesial root. The Student t test and the Welch correlation test were applied to the data obtained. There was a statistically significant difference (P <0.05) between the control and experimental groups. An enhanced response to orthodontic force was observed in the asthmatic animals: the periodontal ligament was more compressed at the pressure area and more stretched in the traction area. Our findings indicate that experimental allergic asthma seems to exacerbate orthodontic movement in rats. Copyright © 2012 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

Ecoinformatics Can Infer Causal Effects of Crop Variety on Insect Attack by Capitalizing on 'Pseudoexperiments' Created When Different Crop Varieties Are Interspersed: A Case Study in Almonds.

PubMed

Rosenheim, Jay A; Higbee, Bradley S; Ackerman, Jonathan D; Meisner, Matthew H

2017-12-05

Capturing the complementary strengths of observational and experimental research methods usually requires the researcher to gather separate experimental and observational data sets. In some cases, however, commercial agricultural practices produce the spatial and temporal mixing of 'treatments' independently of other possibly covarying factors that is normally achieved only with formal experimentation. The resulting 'pseudoexperiments' can provide strong evidence for causal relationships. Here, we analyze a large observational data set that creates a series of such pseudoexperiments to assess the effect of different commercial varieties of almond, Prunus dulcis (Mill.) on the impact of two key lepidopteran pests, the navel orangeworm Amyelois transitella (Walker) (Lepidoptera: Pyralidae), and the peach twig borer Anarsia lineatella Zeller (Lepidoptera: Gelechiidae). Almonds are universally planted as polycultures of different varieties to obtain efficient cross-pollination. We find substantial differences across almond varieties in the rates of infestation of almond hulls and nutmeats by the two pests. We find no support for the hypothesis that earlier-maturing varieties sustain higher attack; for A. transitella, later-maturing varieties instead had more frequent infestation. On many almond varieties, A. lineatella reaches high infestation levels by feeding almost exclusively on the hulls, rather than nutmeats. Given the importance of these pests in directly destroying almond nuts and in promoting aflatoxin-producing Aspergillus sp. fungal infections of almonds, further work exploring the impact of these pests is warranted. Because many crops requiring cross-pollination are planted as mixtures of different varieties, commercial agricultural production data hold great potential for studying within-crop variation in susceptibility to insect attack. © The Author(s) 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Parallel trait adaptation across opposing thermal environments in experimental Drosophila melanogaster populations.

PubMed

Tobler, Ray; Hermisson, Joachim; Schlötterer, Christian

2015-07-01

Thermal stress is a pervasive selective agent in natural populations that impacts organismal growth, survival, and reproduction. Drosophila melanogaster exhibits a variety of putatively adaptive phenotypic responses to thermal stress in natural and experimental settings; however, accompanying assessments of fitness are typically lacking. Here, we quantify changes in fitness and known thermal tolerance traits in replicated experimental D. melanogaster populations following more than 40 generations of evolution to either cyclic cold or hot temperatures. By evaluating fitness for both evolved populations alongside a reconstituted starting population, we show that the evolved populations were the best adapted within their respective thermal environments. More strikingly, the evolved populations exhibited increased fitness in both environments and improved resistance to both acute heat and cold stress. This unexpected parallel response appeared to be an adaptation to the rapid temperature changes that drove the cycling thermal regimes, as parallel fitness changes were not observed when tested in a constant thermal environment. Our results add to a small, but growing group of studies that demonstrate the importance of fluctuating temperature changes for thermal adaptation and highlight the need for additional work in this area. © 2015 The Author(s). Evolution published by Wiley Periodicals, Inc. on behalf of The Society for the Study of Evolution.

A study of hadronic decays of the chi(c) states produced in psi-prime radiative transitions at the Beijing Experimental Spectrometer

NASA Astrophysics Data System (ADS)

Varner, Gary Sim

1999-11-01

Utilizing the world's largest sample of resonant y' decays, as measured by the Beijing Experimental Spectrometer (BES) during 1993-1995, a comprehensive study of the hadronic decay modes of the χc (3P1 Charmonium) states has been undertaken. Compared with the data set for the Mark I detector, whose published measurements of many of these hadronic decays have been definitive for almost 20 years, roughly an order of magnitude larger statistics has been obtained. Taking advantage of these larger statistics, many new hadronic decay modes have been discovered, while others have been refined. An array of first observations, improvements, confirmations or limits are reported with respect to current world values. These higher precision and newly discovered decay modes are an excellent testing ground for recent theoretical interest in the contribution of higher Fock states and the color octet mechanism in heavy quarkonium annihilation and subsequent light hadronization. Because these calculations are largely tractable only in two body decays, these are the focus of this dissertation. A comparison of current theoretical calculations and experimental results is presented, indicating the success of these phenomenological advances. Measurements for which there are as yet no suitable theoretical prediction are indicated.

Calorie menu labeling on quick-service restaurant menus: an updated systematic review of the literature

PubMed Central

2011-01-01

Nutrition labels are one strategy being used to combat the increasing prevalence of overweight and obesity in the United States. The Patient Protection and Affordable Care Act of 2010 mandates that calorie labels be added to menu boards of chain restaurants with 20 or more locations. This systematic review includes seven studies published since the last review on the topic in 2008. Authors searched for peer-reviewed studies using PUBMED and Google Scholar. Included studies used an experimental or quasi-experimental design comparing a calorie-labeled menu with a no-calorie menu and were conducted in laboratories, college cafeterias, and fast food restaurants. Two of the included studies were judged to be of good quality, and five of were judged to be of fair quality. Observational studies conducted in cities after implementation of calorie labeling were imprecise in their measure of the isolated effects of calorie labels. Experimental studies conducted in laboratory settings were difficult to generalize to real world behavior. Only two of the seven studies reported a statistically significant reduction in calories purchased among consumers using calorie-labeled menus. The current evidence suggests that calorie labeling does not have the intended effect of decreasing calorie purchasing or consumption. PMID:22152038

Weighing up the evidence: a systematic review of the effectiveness of workplace interventions to tackle socio-economic inequalities in obesity

PubMed Central

Cairns, Joanne-Marie; Bambra, Clare; Hillier-Brown, Frances C.; Moore, Helen J.; Summerbell, Carolyn D.

2015-01-01

Abstract Background Addressing socio-economic inequalities in obesity is a public health priority and the workplace is seen as a potential health promotion site. However, there is a lack of evidence on what works. This article systematically reviews studies of the effects of workplace interventions on socio-economic inequalities in obesity. Methods Following PRISMA guidelines, we searched for published or unpublished experimental and observational evaluation studies. Nine electronic databases were searched as well as websites and bibliographies. Included studies were data extracted, quality assessed and narratively synthesized. Results Eighteen studies were included of which 14 examined behavioural interventions and 4 mixed or environmental ones. While most studies (n = 12) found no effects on inequalities in obesity—and a minority found increases (n = 3), there was also some evidence of potentially effective workplace interventions (n = 3) especially in terms of physical activity interventions targeted at lower occupational groups. Conclusion There is experimental evidence that workplace delivered physical activity interventions have the potential to reduce inequalities in obesity by targeting lower occupational groups. However, overall, the evidence base is small, largely from the USA, and of a low quality. More high-quality, experimental study designs are required. PMID:25316262

Glucocorticoid levels after exposure to predator odor and chronic psychosocial stress with dexamethasone application in rats.

PubMed

Starcevic, Ana; Petricevic, Sasa; Radojicic, Zoran; Djulejic, Vuk; Ilankovic, Andrej; Starcevic, Branislav; Filipovic, Branislav

2016-05-01

This study was conducted to explore the effects of specific psychosocial paradigm on predator animal posttraumatic stress model and to test the hypothesis that psychosocially stressed rats would exibit abnormal levels of cortisol and a larger suppression of cortisol levels after the application of dexamethasone. Animals were divided in two groups: experimental and control groups. The experimental group was exposed to two types of stressors: acute immobilization stress, and combined predator stress and daily social stress with application of dexamethasone. Blood sampling was performed at three different times. We found statistically significant results after analyzing the differences between cortisol levels in different times of blood sampling in the group of animals exposed to stress with dexamethasone application. Statistical significance was found when we compared the experimental group with the control group in terms of elevated cortisol levels during blood sampling after stress paradigm exposition. Many significant disruptions in the functioning of the hypothalamic-pituitary-adrenal axis were observed, such as decrease in basal cortisol levels and enhanced dexamethasone-induced inhibition of cortisol levels. These findings are important because their impact can translate to human individuals with posttraumatic stress disorder, which is the most important role of every animal model in research. Copyright © 2016. Published by Elsevier Taiwan.

Inverse modeling of the biodegradation of emerging organic contaminants in the soil-plant system.

PubMed

Hurtado, Carlos; Trapp, Stefan; Bayona, Josep M

2016-08-01

Understanding the processes involved in the uptake and accumulation of organic contaminants into plants is very important to assess the possible human risk associated with. Biodegradation of emerging contaminants in plants has been observed, but kinetical studies are rare. In this study, we analyse experimental data on the uptake of emerging organic contaminants into lettuce derived in a greenhouse experiment. Measured soil, root and leaf concentrations from four contaminants were selected within the applicability domain of a steady-state two-compartment standard plant uptake model: bisphenol A (BPA), carbamazepine (CBZ), triclosan (TCS) and caffeine (CAF). The model overestimated concentrations in most cases, when no degradation rates in plants were entered. Subsequently, biodegradation rates were fitted so that the measured concentrations were met. Obtained degradation kinetics are in the order, BPA < CAF ≈ TCS < CBZ in roots, and BPA ≈ TCS < CBZ < CAF in leaves. Kinetics determined by inverse modeling are, despite the inherent uncertainty, indicative of the dissipation rates. The advantage of the procedure that is additional knowledge can be gained from existing experimental data. Dissipation kinetics found via inverse modeling is not a conclusive proof for biodegradation and confirmation by experimental studies is needed. Copyright © 2016. Published by Elsevier Ltd.

Singular observation of the polarization-conversion effect for a gammadion-shaped metasurface

PubMed Central

Lin, Chu-En; Yen, Ta-Jen; Yu, Chih-Jen; Hsieh, Cheng-Min; Lee, Min-Han; Chen, Chii-Chang; Chang, Cheng-Wei

2016-01-01

In this article, the polarization-conversion effects of a gammadion-shaped metasurface in transmission and reflection modes are discussed. In our experiment, the polarization-conversion effect of a gammadion-shaped metasurface is investigated because of the contribution of the phase and amplitude anisotropies. According to our experimental and simulated results, the polarization property of the first-order transmitted diffraction is dominated by linear anisotropy and has weak depolarization; the first-order reflected diffraction exhibits both linear and circular anisotropies and has stronger depolarization than the transmission mode. These results are different from previously published research. The Mueller matrix ellipsometer and polar decomposition method will aid in the investigation of the polarization properties of other nanostructures. PMID:26915332

Linear control of the flywheel inverted pendulum.

PubMed

Olivares, Manuel; Albertos, Pedro

2014-09-01

The flywheel inverted pendulum is an underactuated mechanical system with a nonlinear model but admitting a linear approximation around the unstable equilibrium point in the upper position. Although underactuated systems usually require nonlinear controllers, the easy tuning and understanding of linear controllers make them more attractive for designers and final users. In a recent paper, a simple PID controller was proposed by the authors, leading to an internally unstable controlled plant. To achieve global stability, two options are developed here: first by introducing an internal stabilizing controller and second by replacing the PID controller by an observer-based state feedback control. Simulation and experimental results show the effectiveness of the design. Copyright © 2013 ISA. Published by Elsevier Ltd. All rights reserved.

Comments on Reynolds number effects in wall-bounded shear layers

NASA Technical Reports Server (NTRS)

Bandyopadhyay, Promode R.

1991-01-01

The effect of Reynolds number on the structure of turbulent boundary layers and channel flows is discussed. Published data are reexamined in light of the following questions: (1) does the boundary layer turbulence structure change after the well known Reynolds number limit viz, when Re(theta) is greater than 6000?; (2) is it possible to disturb a high Reynolds number flat plate turbulent boundary layer near the wall such that the recovery length is O(100 delta)?; and (3) how close is the numerically simulated low Reynolds number flat plate turbulence structure to that observed experimentally? The turbulence structure appears to change continuously with Reynolds number virtually throughout the bounday layer and sometimes in unexpected manners at high Reynolds numbers.

Horst Meyer and Quantum Evaporation

NASA Astrophysics Data System (ADS)

Balibar, S.

2016-11-01

With their 1963 article in Cryogenics Horst Meyer and his collaborators triggered intense research activity on the evaporation of superfluid helium. Discussing this subject with him in 1975 was enlightening. Fifty years later, the analogy between the photoelectric effect and the evaporation of superfluid helium in the low temperature limit is not yet clear, although remarkable progress has been made in its observation and its understanding. This special issue of the Journal of Low Temperature Physics is an opportunity to recall the history of quantum evaporation, and to express my gratitude to Horst Meyer. It describes quickly most of the experimental and theoretical works which have been published on quantum evaporation during the last 50 years, but it is not a comprehensive review of this fascinating subject.

The significance of Candida in the human respiratory tract: our evolving understanding.

PubMed

Pendleton, Kathryn M; Huffnagle, Gary B; Dickson, Robert P

2017-04-01

Candida is an opportunistic pathogen and the most commonly isolated fungal genus in humans. Though Candida is often detected in respiratory specimens from humans with and without lung disease, its significance remains undetermined. While historically considered a commensal organism with low virulence potential, the status of Candida as an innocent bystander has recently been called into question by both clinical observations and animal experimentation. We here review what is currently known and yet to be determined about the clinical, microbiological and pathophysiological significance of the detection of Candida spp. in the human respiratory tract. Published by Oxford University Press on behalf of FEMS 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.

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

AlKhaldi, Mashaal Q.; Wehlitz, Ralf, E-mail: rwehlitz@gmail.com

We have experimentally investigated the double-photoionization process in C{sub 6}BrF{sub 5} using monochromatized synchrotron radiation. We compare our results with previously published data for partially deuterated benzene (C{sub 6}H{sub 3}D{sub 3}) over a wide range of photon energies from threshold to 270 eV. A broad resonance in the ratio of doubly to singly charged parent ions at about 65 eV appears shifted in energy compared to benzene data. This shift is due to the difference in the bond lengths in two molecules. A simple model can explain the shape of this resonance. At higher photon energies, we observe another broadmore » resonance that can be explained as a second harmonic of the first resonance.« less

Interventions to prevent respiratory diseases - Nutrition and the developing world.

PubMed

Karim, Tasneem; Muhit, Mohammad; Khandaker, Gulam

2017-03-01

Malnutrition is a major cause of morbidity and mortality in developing countries and nutrition plays a critical role in both acute and chronic respiratory conditions. Inadequacies in the nutritional requirements of a developing lung in utero and in early life can compromise the respiratory system integrity and result in poor lung function, reduced protection against infections, greater likelihood of acute illnesses in childhood and chronic illness in adulthood. Nutritional interventions harness great potential in reducing respiratory illness related morbidity and mortality in the developing world. In this review we have summarized the findings from published systematic reviews/meta-analysis, experimental and observational studies that looked into different nutritional interventions for preventing respiratory diseases in developing countries. Copyright © 2016 Elsevier Ltd. All rights reserved.

Simulation of drop movement over an inclined surface using smoothed particle hydrodynamics.

PubMed

Das, Arup K; Das, Prasanta K

2009-10-06

Smoothed particle hydrodynamics (SPH) is used to numerically simulate the movement of drops down an inclined plane. Diffuse interfaces have been assumed for tracking the motion of the contact line. The asymmetric shape of the three-dimensional drop and the variation of contact angle along its periphery can be calculated using the simulation. During the motion of a liquid drop down an inclined plane, an internal circulation of liquid particles is observed due to gravitational pull which causes periodic change in the drop shape. The critical angle of inclination required for the inception of drop motion is also evaluated for different fluids as a function of drop volume. The numerical predictions exhibit a good agreement with the published experimental results.

Biological Aging - Criteria for Modeling and a New Mechanistic Model

NASA Astrophysics Data System (ADS)

Pletcher, Scott D.; Neuhauser, Claudia

To stimulate interaction and collaboration across scientific fields, we introduce a minimum set of biological criteria that theoretical models of aging should satisfy. We review results of several recent experiments that examined changes in age-specific mortality rates caused by genetic and environmental manipulation. The empirical data from these experiments is then used to test mathematical models of aging from several different disciplines, including molecular biology, reliability theory, physics, and evolutionary biology/population genetics. We find that none of the current models are consistent with all of the published experimental findings. To provide an example of how our criteria might be applied in practice, we develop a new conceptual model of aging that is consistent with our observations.

Automatic identification of bullet signatures based on consecutive matching striae (CMS) criteria.

PubMed

Chu, Wei; Thompson, Robert M; Song, John; Vorburger, Theodore V

2013-09-10

The consecutive matching striae (CMS) numeric criteria for firearm and toolmark identifications have been widely accepted by forensic examiners, although there have been questions concerning its observer subjectivity and limited statistical support. In this paper, based on signal processing and extraction, a model for the automatic and objective counting of CMS is proposed. The position and shape information of the striae on the bullet land is represented by a feature profile, which is used for determining the CMS number automatically. Rapid counting of CMS number provides a basis for ballistics correlations with large databases and further statistical and probability analysis. Experimental results in this report using bullets fired from ten consecutively manufactured barrels support this developed model. Published by Elsevier Ireland Ltd.

A comprehensive combined experimental and computational framework for pre-clinical wear simulation of total knee replacements.

PubMed

Abdelgaied, A; Fisher, J; Jennings, L M

2018-02-01

A more robust pre-clinical wear simulation framework is required in order to simulate wider and higher ranges of activities, observed in different patient populations such as younger more active patients. Such a framework will help to understand and address the reported higher failure rates for younger and more active patients (National_Joint_Registry, 2016). The current study has developed and validated a comprehensive combined experimental and computational framework for pre-clinical wear simulation of total knee replacements (TKR). The input mechanical (elastic modulus and Poisson's ratio) and wear parameters of the moderately cross-linked ultra-high molecular weight polyethylene (UHMWPE) bearing material were independently measured from experimental studies under realistic test conditions, similar to the loading conditions found in the total knee replacements. The wear predictions from the computational wear simulation were validated against the direct experimental wear measurements for size 3 Sigma curved total knee replacements (DePuy, UK) in an independent experimental wear simulation study under three different daily activities; walking, deep squat, and stairs ascending kinematic conditions. The measured compressive mechanical properties of the moderately cross-linked UHMWPE material were more than 20% lower than that reported in the literature under tensile test conditions. The pin-on-plate wear coefficient of moderately cross-linked UHMWPE was significantly dependant of the contact stress and the degree of cross-shear at the articulating surfaces. The computational wear predictions for the TKR from the current framework were consistent and in a good agreement with the independent full TKR experimental wear simulation measurements, with 0.94 coefficient of determination of the framework. In addition, the comprehensive combined experimental and computational framework was able to explain the complex experimental wear trends from the three different daily activities investigated. Therefore, such a framework can be adopted as a pre-clinical simulation approach to optimise different designs, materials, as well as patient's specific total knee replacements for a range of activities. Copyright © 2017. Published by Elsevier Ltd.

A Meta-Analysis of Empirical Research on Teaching Students with Mathematics Learning Difficulties

ERIC Educational Resources Information Center

Dennis, Minyi Shih; Sharp, Emily; Chovanes, Jacquelyn; Thomas, Amanda; Burns, Raquel M.; Custer, Beth; Park, Junkoung

2016-01-01

This article quantitatively summarizes experimental and quasi-experimental studies on teaching students with mathematics difficulties (MD) published between 2000 and 2014, research that was available following earlier syntheses. It reports the analysis of effect sizes of 25 intervention studies on participant characteristics, intervention…

Experimental Trends in Videoprogramming.

ERIC Educational Resources Information Center

Kalba, Kas

A review of experimental activities in educational broadcasting shows that mass television and instructional television, as we think of them today, are likely to constitute two points on a greatly expanded spectrum of television concepts in the future. Television will become much more like the publishing industry, with its mix of pamphlets, art…

Forest pathology and entomology at Fort Valley Experimental Forest

Treesearch

Brian W. Geils

2008-01-01

Forest pathology and entomology have been researched at Fort Valley Experimental Forest throughout its history. The pathogens and insects of particular interest are mistletoes, decay and canker fungi, rusts, bark beetles, and various defoliators. Studies on life history, biotic interactions, impacts, and control have been published and incorporated into silvicultural...

Effect of Heart Rate Variability Biofeedback on Sport Performance, a Systematic Review.

PubMed

Jiménez Morgan, Sergio; Molina Mora, José Arturo

2017-09-01

Aim is to determine if the training with heart rate variability biofeedback allows to improve performance in athletes of different disciplines. Methods such as database search on Web of Science, SpringerLink, EBSCO Academic Search Complete, SPORTDiscus, Pubmed/Medline, and PROQUEST Academic Research Library, as well as manual reference registration. The eligibility criteria were: (a) published scientific articles; (b) experimental studies, quasi-experimental, or case reports; (c) use of HRV BFB as main treatment; (d) sport performance as dependent variable; (e) studies published until October 2016; (f) studies published in English, Spanish, French or Portuguese. The guidelines of the PRISMA statement were followed. Out of the 451 records found, seven items were included. All studies had a small sample size (range from 1 to 30 participants). In 85.71% of the studies (n = 6) the athletes enhanced psychophysiological variables that allowed them to improve their sport performance thanks to training with heart rate variability biofeedback. Despite the limited amount of experimental studies in the field to date, the findings suggest that heart rate variability biofeedback is an effective, safe, and easy-to-learn and apply method for both athletes and coaches in order to improve sport performance.

Modeling the concentration-dependent permeation modes of the KcsA potassium ion channel.

PubMed

Nelson, Peter Hugo

2003-12-01

The potassium channel from Streptomyces lividans (KcsA) is an integral membrane protein with sequence similarity to all known potassium channels, particularly in the selectivity filter region. A recently proposed model for ion channels containing either n or (n-1) single-file ions in their selectivity filters [P. H. Nelson, J. Chem. Phys. 177, 11396 (2002)] is applied to published KcsA channel K+ permeation data that exhibit a high-affinity process at low concentrations and a low-affinity process at high concentrations [M. LeMasurier et al., J. Gen. Physiol. 118, 303 (2001)]. The kinetic model is shown to provide a reasonable first-order explanation for both the high- and low-concentration permeation modes observed experimentally. The low-concentration mode ([K+]<200 mM) has a 200-mV dissociation constant of 56 mM and a conductance of 88 pS. The high-concentration mode ([K+]>200 mM) has a 200-mV dissociation constant of 1100 mM and a conductance of 500 pS. Based on the permeation model, and x-ray analysis [J. H. Morais-Cabral et al., Nature (London) 414, 37 (2001)], it is suggested that the experimentally observed K+ permeation modes correspond to an n=3 mechanism at high concentrations and an n=2 mechanism at low concentrations. The ratio of the electrical dissociation distances for the high- and low-concentration modes is 3:2, also consistent with the proposed n=3 and n=2 modes. Model predictions for K+ channels that exhibit asymmetric current-voltage (I-V) curves are presented, and further validation of the kinetic model via molecular simulation and experiment is discussed. The qualitatively distinct I-V characteristics exhibited experimentally by Tl+, NH+4, and Rb+ ions at 100 mM concentration can also be explained using the model, but more extensive experimental tests are required for quantitative validation of the model predictions.

Modeling the concentration-dependent permeation modes of the KcsA potassium ion channel

NASA Astrophysics Data System (ADS)

Nelson, Peter Hugo

2003-12-01

The potassium channel from Streptomyces lividans (KcsA) is an integral membrane protein with sequence similarity to all known potassium channels, particularly in the selectivity filter region. A recently proposed model for ion channels containing either n or (n-1) single-file ions in their selectivity filters [P. H. Nelson, J. Chem. Phys. 177, 11396 (2002)] is applied to published KcsA channel K+ permeation data that exhibit a high-affinity process at low concentrations and a low-affinity process at high concentrations [M. LeMasurier et al., J. Gen. Physiol. 118, 303 (2001)]. The kinetic model is shown to provide a reasonable first-order explanation for both the high- and low-concentration permeation modes observed experimentally. The low-concentration mode ([K+]<200 mM) has a 200-mV dissociation constant of 56 mM and a conductance of 88 pS. The high-concentration mode ([K+]>200 mM) has a 200-mV dissociation constant of 1100 mM and a conductance of 500 pS. Based on the permeation model, and x-ray analysis [J. H. Morais-Cabral et al., Nature (London) 414, 37 (2001)], it is suggested that the experimentally observed K+ permeation modes correspond to an n=3 mechanism at high concentrations and an n=2 mechanism at low concentrations. The ratio of the electrical dissociation distances for the high- and low-concentration modes is 3:2, also consistent with the proposed n=3 and n=2 modes. Model predictions for K+ channels that exhibit asymmetric current-voltage (I-V) curves are presented, and further validation of the kinetic model via molecular simulation and experiment is discussed. The qualitatively distinct I-V characteristics exhibited experimentally by Tl+, NH+4, and Rb+ ions at 100 mM concentration can also be explained using the model, but more extensive experimental tests are required for quantitative validation of the model predictions.

Lattice-Boltzmann Modeling of Community Challenge MicrofluidicExperiments to Evaluate the Effects of Wettability on Two-Fluid Flowin Porous Media

NASA Astrophysics Data System (ADS)

Miller, C. T.; McClure, J. E.; Bruning, K.

2017-12-01

Variations in the wettability of a solid material are well known to affect the flow of two fluids in a porous media. However, thesemechanisms have not been modeled with high fidelity at the microscale and such mechanisms are typically not included in macroscalemodels. Recent experimental work by Zhao, MacMinn, and Juanes published in the Proceedings of the National Academy of Sciences(2016) has investigated two-fluid displacement in microfluidic cells. Displacement patterns were investigated as a function of thecontact angle and the capillary number for both drainage and imbibition. These results yielded new mechanistic understanding ofprocesses such as pore filling and post bridging, which were imaged at high resolution. In a challenge to the pore-scale modeling community,the authors of this work released their experimental data and encouraged an international set of modeling research groups tosimulate the conditions that were experimentally observed. The intent is to compare the results that materialize to shed new light on thestate-of-science in pore-scale simulation of these challenging and interesting flow systems. In this work, we summarize the experimentalfindings and report on initial efforts to simulate these community challenge experiments using a high-resolution lattice-Boltzmann method(LBM). A three-dimensional, multiple-relaxation-time color model based on a 19-site lattice is advanced in this work to matchexperimental conditions in a novel manner. A computational approach is implemented for the LBM method on hybrid CPU-GPU nodes and shown toscale near optimally. A new algorithm is described to match experimental boundary conditions. A grid-resolution study is performedto determine the resolution needed to determine grid-independent numerical approximations. Finally, the LBM simulation results arecompared to the highly resolved microfluidic experiments, displacement mechanisms are investigated, and observations and analysis of thetopological state evolution of the system are reported.

Evaluation of a randomized controlled trial in the management of chronic lower back pain in a French automotive industry: an observational study.

PubMed

Nassif, Hala; Brosset, Nicolas; Guillaume, Marion; Delore-Milles, Emilie; Tafflet, Muriel; Buchholz, Frédéric; Toussaint, Jean-François

2011-12-01

To evaluate a specific workplace intervention for the management of chronic lower back pain among employees working in assembly positions in the automotive industry. Randomized controlled trial. On site at the workplace of a French automotive manufacturer. Subjects (N=75 volunteers) were recruited on site and randomly assigned to either an experimental group (n=37) or a control group (n=38). The experimental group followed a supervised 60-minute session, 3 times per week, of muscle strengthening, flexibility, and endurance training during 2 months. The control group received no direct intervention. Evaluation took place at baseline, 2 months, and 6 months. Pain related parameters were evaluated using validated questionnaires and scales translated into French (Quebec Back Pain Disability Scale, Rolan Morris Disability Questionnaire, Dallas Pain Questionnaire, and the Tampa Scale for Kinesiophobia). Perceived pain intensity was evaluated using the numerical rating scale, and physical outcome measures were evaluated using specific indicators (flexibility, Biering-Sorensen Test, Shirado test). The multivariate analysis of variance, t test, and Wilcoxon signed-rank test were used for statistical analysis. We observed a significant beneficial effect (P<.025) for the experimental group at 2 and 6 months in pain parameters, specific flexibility, and in back functions, and a significant improvement at 6 months in the control group for the perceived pain intensity, anterior flexion, flexibility of quadriceps, and Dallas Pain Questionnaire's work recreational score. An increase in the practice of physical activity outside the workplace was noted in both groups at 2 months but persisted at 6 months for the experimental group. This study reinforces the multiple health benefits of physical activity and physical therapy modalities in the workplace by assisting individuals at risk who have chronic LBP. Copyright © 2011 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Developing an Empirical Model for Jet-Surface Interaction Noise

NASA Technical Reports Server (NTRS)

Brown, Clifford A.

2014-01-01

The process of developing an empirical model for jet-surface interaction noise is described and the resulting model evaluated. Jet-surface interaction noise is generated when the high-speed engine exhaust from modern tightly integrated or conventional high-bypass ratio engine aircraft strikes or flows over the airframe surfaces. An empirical model based on an existing experimental database is developed for use in preliminary design system level studies where computation speed and range of configurations is valued over absolute accuracy to select the most promising (or eliminate the worst) possible designs. The model developed assumes that the jet-surface interaction noise spectra can be separated from the jet mixing noise and described as a parabolic function with three coefficients: peak amplitude, spectral width, and peak frequency. These coefficients are fit to functions of surface length and distance from the jet lipline to form a characteristic spectra which is then adjusted for changes in jet velocity and/or observer angle using scaling laws from published theoretical and experimental work. The resulting model is then evaluated for its ability to reproduce the characteristic spectra and then for reproducing spectra measured at other jet velocities and observer angles; successes and limitations are discussed considering the complexity of the jet-surface interaction noise versus the desire for a model that is simple to implement and quick to execute.

Nonequilibrium fluctuations in a frictional granular motor: Experiments and kinetic theory

NASA Astrophysics Data System (ADS)

Gnoli, Andrea; Sarracino, Alessandro; Puglisi, Andrea; Petri, Alberto

2013-05-01

We report the study of an experimental granular Brownian motor, inspired by the one published in Eshuis [Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.104.248001 104, 248001 (2010)], but different in some ingredients. As in that previous work, the motor is constituted by a rotating blade, the surfaces of which break the rotation-inversion symmetry through alternated patches of different inelasticity, immersed in a gas of granular particles. The main difference of our experimental setup is in the orientation of the main axis, which is parallel to the (vertical) direction of shaking of the granular fluid, guaranteeing an isotropic distribution for the velocities of colliding grains, characterized by a variance v02. We also keep the granular system diluted, in order to compare with Boltzmann-equation-based kinetic theory. In agreement with theory, we observe the crucial role of Coulomb friction which induces two main regimes: (i) rare collisions, with an average angular velocity <ω>˜v03, and (ii) frequent collisions (FC), with <ω>˜v0. We also study the fluctuations of the angle spanned in a large-time interval Δθ, which in the FC regime is proportional to the work done upon the motor. We observe that the fluctuation relation is satisfied with a slope which weakly depends on the relative collision frequency.

An Arrhenius-type viscosity function to model sintering using the Skorohod Olevsky viscous sintering model within a finite element code.

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

Ewsuk, Kevin Gregory; Arguello, Jose Guadalupe, Jr.; Reiterer, Markus W.

2006-02-01

The ease and ability to predict sintering shrinkage and densification with the Skorohod-Olevsky viscous sintering (SOVS) model within a finite-element (FE) code have been improved with the use of an Arrhenius-type viscosity function. The need for a better viscosity function was identified by evaluating SOVS model predictions made using a previously published polynomial viscosity function. Predictions made using the original, polynomial viscosity function do not accurately reflect experimentally observed sintering behavior. To more easily and better predict sintering behavior using FE simulations, a thermally activated viscosity function based on creep theory was used with the SOVS model. In comparison withmore » the polynomial viscosity function, SOVS model predictions made using the Arrhenius-type viscosity function are more representative of experimentally observed viscosity and sintering behavior. Additionally, the effects of changes in heating rate on densification can easily be predicted with the Arrhenius-type viscosity function. Another attribute of the Arrhenius-type viscosity function is that it provides the potential to link different sintering models. For example, the apparent activation energy, Q, for densification used in the construction of the master sintering curve for a low-temperature cofire ceramic dielectric has been used as the apparent activation energy for material flow in the Arrhenius-type viscosity function to predict heating rate-dependent sintering behavior using the SOVS model.« less

Attempts to Manipulate the Decay Time of Radioactive Nuclei

NASA Astrophysics Data System (ADS)

Fallin, B.; Grabow, B.; Tornow, W.

2008-04-01

It has been known for 20 years that electron screening strongly changes nuclear reaction cross sections at sub-Coulomb charged-particle projectile energies. The screening energy can be increased considerably if the target atoms are implanted in a metallic host and cooled to low temperature (T˜10 K). The large screening in metals derives from the Debye plasma model applied to the quasi-free metallic electrons. If ``time reversed,'' this model implies that the lifetime of radioactive nuclei placed in a metallic host can be manipulated by orders of magnitude. For α and β^+ decay one expects a shorter half-life, while for β^- decay and EC, a longer half-life is expected. The results of prior experiments testing this theory are controversial; about half of the published data confirm an effect, while the other half observe no effect. We will report on our experimental studies using ^64Cu and ^65Zn nuclei produced at TUNL via the ^63Cu(d,p) and ^65Cu(p,n) reactions, respectively. For ^64Cu, we detected the 511 keV annihilation γ rays and for ^65Zn the 1115.5 keV γ rays using HPGe detectors. In both cases we did not observe a half-life change outside experimental uncertainties between measurements at room temperature and those with the samples cooled to T=12 K.

Changes in gait patterns induced by rhythmic auditory stimulation for adolescents with acquired brain injury.

PubMed

Kim, Soo Ji; Shin, Yoon-Kyum; Yoo, Ga Eul; Chong, Hyun Ju; Cho, Sung-Rae

2016-12-01

The effects of rhythmic auditory stimulation (RAS) on gait in adolescents with acquired brain injury (ABI) were investigated. A total of 14 adolescents with ABI were initially recruited, and 12 were included in the final analysis (n = 6 each). They were randomly assigned to the experimental (RAS) or the control (conventional gait training) groups. The experimental group received gait training with RAS three times a week for 4 weeks. For both groups, spatiotemporal parameters and kinematic data, such as dynamic motions of joints on three-dimensional planes during a gait cycle and the range of motion in each joint, were collected. Significant group differences in pre-post changes were observed in cadence, walking velocity, and step time, indicating that there were greater improvements in those parameters in the RAS group compared with the control group. Significant increases in hip and knee motions in the sagittal plane were also observed in the RAS group. The changes in kinematic data significantly differed between groups, particularly from terminal stance to mid-swing phase. An increase of both spatiotemporal parameters and corresponding kinematic changes of hip and knee joints after RAS protocol indicates that the use of rhythmic cueing may change gait patterns in adolescents with ABI. © 2016 The Authors. Annals of the New York Academy of Sciences published by Wiley Periodicals, Inc. on behalf of New York Academy of Sciences.

Development of a Predictive Model for the Stabilizer Concentration Estimation in Microreservoir Transdermal Drug Delivery Systems Using Lipophilic Pressure-Sensitive Adhesives as Matrix/Carrier.

PubMed

Chenevas-Paule, Clémence; Wolff, Hans-Michael; Ashton, Mark; Schubert, Martin; Dodou, Kalliopi

2017-05-01

Microreservoir-type transdermal drug delivery systems (MTDDS) can prevent drug crystallization; however, no current predictive model considers the impact of drug load and hydration on their physical stability. We investigated MTDDS films containing polyvinylpyrrolidone (PVP) as polymeric drug stabilizer in lipophilic pressure-sensitive adhesive (silicone). Medicated and unmedicated silicone films with different molar N-vinylpyrrolidone:drug ratios were prepared and characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry, scanning electron microscopy, microscopy, dynamic vapor sorption (DVS), and stability testing for 4 months at different storage conditions. Homogeneously distributed drug-PVP associates were observed when nonaqueous emulsions, containing drug-PVP (inner phase) and silicone adhesive (outer phase), were dried to films. DVS data were essential to predict physical stability at different humidities. A predictive thermodynamic model was developed based on drug-polymer hydrogen-bonding interactions, using the Hoffman equation, to estimate the drug-PVP ratio needed to obtain stable MTDDS and to evaluate the impact of humidity on their physical stability. This new approach considers the impact of polymorphism on drug solubility by using easily accessible experimental data (T m and DVS) and avoids uncertainties associated with the solubility parameter approach. In conclusion, a good fit of predicted and experimental data was observed. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

Nuclear Data Sheets for A = 94

NASA Astrophysics Data System (ADS)

Abriola, D.; Sonzogni, A. A.

2006-09-01

Experimental data on ground- and excited-state properties for all known nuclei with mass number A = 94 have been compiled and evaluated. States populated in radioactive decay, as well as in nuclear reactions, have been considered. For these nuclei, level and decay schemes, as well as tables of nuclear properties, are given. The Hager-Seltzer internal conversion coefficients are listed for gamma rays of known multipolarity. This work supersedes the 1992 evaluation by J.K. Tuli (1992Tu02). Since 1992, many articles have been published which were incorporated in this evaluation. In summary, high-spin data using large arrays of Ge detectors have been obtained for 94Kr (2000Rz02), 94Sr (1995Ha20), 94Zr (2002Fo03,2005Pa48), 94Nb (2000Ma63), 94Mo (1998Kh04), 94Tc (2000Gh01), 94Ru (1994Ju03,1994Ro08), 94Rh (1994Ar33), and 94Pd (2003Ma24). A new isomer was observed in 94Y (1999Ge01). The low-spin levels in 98Mo were systematically studied using a variety of experimental techniques (2003Fr02). Considerable effort was spent investigating the decay of 94Ag and the levels of 94Pd (2006Mu03,2005Mu15,2004BaZY,2004Pl01,2002La18), in particular, the (21+) level in 94Ag is the first level observed to undergo both single and double proton radioactivity.

Proposal for a new categorization of aseptic processing facilities based on risk assessment scores.

PubMed

Katayama, Hirohito; Toda, Atsushi; Tokunaga, Yuji; Katoh, Shigeo

2008-01-01

Risk assessment of aseptic processing facilities was performed using two published risk assessment tools. Calculated risk scores were compared with experimental test results, including environmental monitoring and media fill run results, in three different types of facilities. The two risk assessment tools used gave a generally similar outcome. However, depending on the tool used, variations were observed in the relative scores between the facilities. For the facility yielding the lowest risk scores, the corresponding experimental test results showed no contamination, indicating that these ordinal testing methods are insufficient to evaluate this kind of facility. A conventional facility having acceptable aseptic processing lines gave relatively high risk scores. The facility showing a rather high risk score demonstrated the usefulness of conventional microbiological test methods. Considering the significant gaps observed in calculated risk scores and in the ordinal microbiological test results between advanced and conventional facilities, we propose a facility categorization based on risk assessment. The most important risk factor in aseptic processing is human intervention. When human intervention is eliminated from the process by advanced hardware design, the aseptic processing facility can be classified into a new risk category that is better suited for assuring sterility based on a new set of criteria rather than on currently used microbiological analysis. To fully benefit from advanced technologies, we propose three risk categories for these aseptic facilities.

Developing an Empirical Model for Jet-Surface Interaction Noise

NASA Technical Reports Server (NTRS)

Brown, Clif

2014-01-01

The process of developing an empirical model for jet-surface interaction noise is described and the resulting model evaluated. Jet-surface interaction noise is generated when the high-speed engine exhaust from modern tightly integrated or conventional high-bypass ratio engine aircraft strikes or flows over the airframe surfaces. An empirical model based on an existing experimental database is developed for use in preliminary design system level studies where computation speed and range of configurations is valued over absolute accuracy to select the most promising (or eliminate the worst) possible designs. The model developed assumes that the jet-surface interaction noise spectra can be separated from the jet mixing noise and described as a parabolic function with three coefficients: peak amplitude, spectral width, and peak frequency. These coefficients are t to functions of surface length and distance from the jet lipline to form a characteristic spectra which is then adjusted for changes in jet velocity and/or observer angle using scaling laws from published theoretical and experimental work. The resulting model is then evaluated for its ability to reproduce the characteristic spectra and then for reproducing spectra measured at other jet velocities and observer angles; successes and limitations are discussed considering the complexity of the jet-surface interaction noise versus the desire for a model that is simple to implement and quick to execute.

Investigation on heat transfer characteristics and flow performance of Methane at supercritical pressures

NASA Astrophysics Data System (ADS)

Xian, Hong Wei; Oumer, A. N.; Basrawi, F.; Mamat, Rizalman; Abdullah, A. A.

2018-04-01

The aim of this study is to investigate the heat transfer and flow characteristic of cryogenic methane in regenerative cooling system at supercritical pressures. The thermo-physical properties of supercritical methane were obtained from the National institute of Standards and Technology (NIST) webbook. The numerical model was developed based on the assumptions of steady, turbulent and Newtonian flow. For mesh independence test and model validation, the simulation results were compared with published experimental results. The effect of four different performance parameter ranges namely inlet pressure (5 to 8 MPa), inlet temperature (120 to 150 K), heat flux (2 to 5 MW/m2) and mass flux (7000 to 15000 kg/m2s) on heat transfer and flow performances were investigated. It was found that the simulation results showed good agreement with experimental data with maximum deviation of 10 % which indicates the validity of the developed model. At low inlet temperature, the change of specific heat capacity at near-wall region along the tube length was not significant while the pressure drop registered was high. However, significant variation was observed for the case of higher inlet temperature. It was also observed that the heat transfer performance and pressure drop penalty increased when the mass flux was increased. Regarding the effect of inlet pressure, the heat transfer performance and pressure drop results decreased when the inlet pressure is increased.

Measurement of photoemission and secondary emission from laboratory dust grains

NASA Technical Reports Server (NTRS)

Hazelton, Robert C.; Yadlowsky, Edward J.; Settersten, Thomas B.; Spanjers, Gregory G.; Moschella, John J.

1995-01-01

The overall goal of this project is experimentally determine the emission properties of dust grains in order to provide theorists and modelers with an accurate data base to use in codes that predict the charging of grains in various plasma environments encountered in the magnetospheres of the planets. In general these modelers use values which have been measured on planar, bulk samples of the materials in question. The large enhancements expected due to the small size of grains can have a dramatic impact upon the predictions and the ultimate utility of these predictions. The first experimental measurement of energy resolved profiles of the secondary electron emission coefficient, 6, of sub-micron diameter particles has been accomplished. Bismuth particles in the size range of .022 to .165 micrometers were generated in a moderate pressure vacuum oven (average size is a function of oven temperature and pressure) and introduced into a high vacuum chamber where they interacted with a high energy electron beam (0.4 to 20 keV). Large enhancements in emission were observed with a peak value, delta(sub max) = 4. 5 measured for the ensemble of particles with a mean size of .022 micrometers. This is in contrast to the published value, delta(sub max) = 1.2, for bulk bismuth. The observed profiles are in general agreement with recent theoretical predictions made by Chow et al. at UCSD.

Evidence for host genetic regulation of altered lipid metabolism in experimental toxoplasmosis supported with gene data mining results

PubMed Central

2017-01-01

Toxoplasma gondii is one of the most successful parasites on Earth, infecting a wide array of mammals including one third of the global human population. The obligate intracellular protozoon is not capable of synthesizing cholesterol (Chl), and thus depends on uptake of host Chl for its own development. To explore the genetic regulation of previously observed lipid metabolism alterations during acute murine T. gondii infection, we here assessed total Chl and its fractions in serum and selected tissues at the pathophysiological and molecular level, and integrated the observed gene expression of selected molecules relevant for Chl metabolism, including its biosynthetic and export KEGG pathways, with the results of published transcriptomes obtained in similar murine models of T. gondii infection. The serum lipid status as well as the transcript levels of relevant genes in the brain and the liver were assessed in experimental models of acute and chronic toxoplasmosis in wild-type mice. The results showed that acute infection was associated with a decrease in Chl content in both the liver and periphery (brain, peripheral lymphocytes), and a decrease in Chl reverse transport. In contrast, in chronic infection, a return to normal levels of Chl metabolism has been noted. These changes corresponded to the brain and liver gene expression results as well as to data obtained via mining. We propose that the observed changes in Chl metabolism are part of the host defense response. Further insight into the lipid metabolism in T. gondii infection may provide novel targets for therapeutic agents. PMID:28459857

Active placebo control groups of pharmacological interventions were rarely used but merited serious consideration: a methodological overview.

PubMed

Jensen, Jakob Solgaard; Bielefeldt, Andreas Ørsted; Hróbjartsson, Asbjørn

2017-07-01

Active placebos are control interventions that mimic the side effects of the experimental interventions in randomized trials and are sometimes used to reduce the risk of unblinding. We wanted to assess how often randomized clinical drug trials use active placebo control groups; to provide a catalog, and a characterization, of such trials; and to analyze methodological arguments for and against the use of active placebo. An overview consisting of three thematically linked substudies. In an observational substudy, we assessed the prevalence of active placebo groups based on a random sample of 200 PubMed indexed placebo-controlled randomized drug trials published in October 2013. In a systematic review, we identified and characterized trials with active placebo control groups irrespective of publication time. In a third substudy, we reviewed publications with substantial methodological comments on active placebo groups (searches in PubMed, The Cochrane Library, Google Scholar, and HighWirePress). The prevalence of trials with active placebo groups published in 2013 was 1 out of 200 (95% confidence interval: 0-2), 0.5% (0-1%). We identified and characterized 89 randomized trials (published 1961-2014) using active placebos, for example, antihistamines, anticholinergic drugs, and sedatives. Such trials typically involved a crossover design, the experimental intervention had noticeable side effects, and the outcomes were patient-reported. The use of active placebos was clustered in specific research settings and did not appear to reflect consistently the side effect profile of the experimental intervention, for example, selective serotonin reuptake inhibitors were compared with active placebos in pain trials but not in depression trials. We identified and analyzed 25 methods publications with substantial comments. The main argument for active placebo was to reduce risk of unblinding; the main argument against was the risk of unintended therapeutic effect. Pharmacological active placebo control interventions are rarely used in randomized clinical trials, but they constitute a methodological tool which merits serious consideration. We suggest that active placebos are used more often in trials of drugs with noticeable side effects, especially in situations where the expected therapeutic effects are modest and the risk of bias due to unblinding is high. Copyright © 2017 Elsevier Inc. All rights reserved.

Empirical modeling of dynamic behaviors of pneumatic artificial muscle actuators.

PubMed

Wickramatunge, Kanchana Crishan; Leephakpreeda, Thananchai

2013-11-01

Pneumatic Artificial Muscle (PAM) actuators yield muscle-like mechanical actuation with high force to weight ratio, soft and flexible structure, and adaptable compliance for rehabilitation and prosthetic appliances to the disabled as well as humanoid robots or machines. The present study is to develop empirical models of the PAM actuators, that is, a PAM coupled with pneumatic control valves, in order to describe their dynamic behaviors for practical control design and usage. Empirical modeling is an efficient approach to computer-based modeling with observations of real behaviors. Different characteristics of dynamic behaviors of each PAM actuator are due not only to the structures of the PAM actuators themselves, but also to the variations of their material properties in manufacturing processes. To overcome the difficulties, the proposed empirical models are experimentally derived from real physical behaviors of the PAM actuators, which are being implemented. In case studies, the simulated results with good agreement to experimental results, show that the proposed methodology can be applied to describe the dynamic behaviors of the real PAM actuators. Copyright © 2013 ISA. Published by Elsevier Ltd. All rights reserved.

Immunization of mice with LRP4 induces myasthenia similar to MuSK-associated myasthenia gravis.

PubMed

Mori, Shuuichi; Motohashi, Norio; Takashima, Rumi; Kishi, Masahiko; Nishimune, Hiroshi; Shigemoto, Kazuhiro

2017-11-01

Since the first report of experimental animal models of myasthenia gravis (MG) with autoantibodies against low-density lipoprotein receptor-related protein 4 (LRP4), there have not been any major reports replicating the pathogenicity of anti-LRP4 antibodies (Abs). Recent clinical studies have cast doubt on the specificity and pathogenicity of anti-LRP4 antibodies for MG, highlighting the need for further research. In this study, we purified antigens corresponding to the extracellular region of human LRP4 stably expressed with chaperones in 293 cells and used these antigens to immunize female A/J mice. Immunization with LRP4 protein caused mice to develop myasthenia having similar electrophysiological and histological features as are observed in MG patients with circulating Abs against muscle-specific kinase (MuSK). Our results clearly demonstrate that active immunization of mice with LRP4 proteins causes myasthenia similar to the MG induced by anti-MuSK Abs. Further experimental and clinical studies are required to prove the pathogenicity of anti-LRP4 Abs in MG patients. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Effect of the use of combination uridine triphosphate, cytidine monophosphate, and hydroxycobalamin on the recovery of neurosensory disturbance after bilateral sagittal split osteotomy: a randomized, double-blind trial.

PubMed

Vieira, C L; Vasconcelos, B C do E; Leão, J C; Laureano Filho, J R

2016-02-01

The change in neurosensory lesions that develop after bilateral sagittal split osteotomy (BSSO) was explored, and the influence of the application of combination uridine triphosphate (UTP), cytidine monophosphate (CMP), and hydroxycobalamin (vitamin B12) on patient outcomes was assessed. This was a randomized, controlled, double-blind trial. The study sample comprised 12 patients, each evaluated on both sides (thus 24 sides). All patients fulfilled defined selection criteria. Changes in the lesions were measured both subjectively and objectively. The sample was divided into two patient groups: an experimental group receiving medication and a control group receiving placebo. The statistical analysis was performed using SPSS software. Lesions in both groups improved and no statistically significant difference between the groups was observed at any time. 'Severe' injuries in the experimental group were more likely to exhibit a significant improvement after 6 months. Based on the results of the present study, it is concluded that the combination UTP, CMP, and hydroxycobalamin did not influence recovery from neurosensory disorders. Copyright © 2015. Published by Elsevier Ltd.

In silico assessment of the conduction mechanism of the Ryanodine Receptor 1 reveals previously unknown exit pathways.

PubMed

Heinz, Leonard P; Kopec, Wojciech; de Groot, Bert L; Fink, Rainer H A

2018-05-02

The ryanodine receptor 1 is a large calcium ion channel found in mammalian skeletal muscle. The ion channel gained a lot of attention recently, after multiple independent authors published near-atomic cryo electron microscopy data. Taking advantage of the unprecedented quality of structural data, we performed molecular dynamics simulations on the entire ion channel as well as on a reduced model. We calculated potentials of mean force for Ba 2+ , Ca 2+ , Mg 2+ , K + , Na + and Cl - ions using umbrella sampling to identify the key residues involved in ion permeation. We found two main binding sites for the cations, whereas the channel is strongly repulsive for chloride ions. Furthermore, the data is consistent with the model that the receptor achieves its ion selectivity by over-affinity for divalent cations in a calcium-block-like fashion. We reproduced the experimental conductance for potassium ions in permeation simulations with applied voltage. The analysis of the permeation paths shows that ions exit the pore via multiple pathways, which we suggest to be related to the experimental observation of different subconducting states.

What works in family planning interventions: A systematic review of the evidence

PubMed Central

Mwaikambo, Lisa; Speizer, Ilene S.; Schurmann, Anna; Morgan, Gwen; Fikree, Fariyal

2013-01-01

This study presents findings from a systematic review of evaluations of family planning interventions published between 1995 and 2008. Studies that used an experimental or quasi-experimental design or had another way to attribute program exposure to observed changes in fertility or family planning outcomes at the individual or population levels were included and ranked by strength of evidence. A total of 63 studies were found that met the inclusion criteria. The findings from this review are summarized in tabular format by the type of intervention (classified as supply-side or demand-side). About two-thirds of the studies found were on demand generation type-programs. Findings from all programs revealed significant improvements in knowledge, attitudes, discussion, and intentions. Program impacts on contraceptive use and use of family planning services were less consistently found and less than half of the studies that measured fertility or pregnancy-related outcomes found an impact. Based on the review findings, we identify promising programmatic approaches and propose directions for future evaluation research of family planning interventions. PMID:21834409

Ammonium stimulates nitrate reduction during simultaneous nitrification and denitrification process by Arthrobacter arilaitensis Y-10.

PubMed

He, Tengxia; Xie, Deti; Li, Zhenlun; Ni, Jiupai; Sun, Quan

2017-09-01

The ability of Arthrobacter arilaitensis Y-10 for nitrogen removal from simulated wastewater was studied. Results showed that ammonium was the best inorganic nitrogen for strain Y-10's cell growth, which could also promote nitrate reduction. Approximately 100.0% of ammonium was removed in the nitrogen removal experiments. The nitrate removal efficiency was 73.3% with nitrate as sole nitrogen source, and then the nitrate efficiency was increased to 85.3% and 100.0% with ammonium and nitrate (both about 5 or 100mg/L) as the mixed nitrogen sources. Nitrite accumulation was observed in presence of ammonium and nitrate. When the concentration of sole nitrite nitrogen was 10.31mg/L, the nitrite removal efficiency was 100.0%. Neither ammonium nor nitrate was accumulated during the whole experimental process. All experimental results indicated that A. arilaitensis Y-10 could remove ammonium, nitrate and nitrite at 15°C from wastewater, and could also perform simultaneous nitrification and denitrification under aerobic condition. Copyright © 2017. Published by Elsevier Ltd.

Origin matters: diversity affects the performance of alien invasive species but not of native species.

PubMed

Sun, Yan; Müller-Schärer, Heinz; Maron, John L; Schaffner, Urs

2015-06-01

At local scales, it has often been found that invasibility decreases with increasing resident plant diversity. However, whether resident community diversity similarly resists invasion by alien versus native species is seldom studied. We examined this issue by invading constructed native plant assemblages that varied in species and functional richness with invasive alien or native Asteraceae species. Assemblages were also invaded with spotted knapweed, Centaurea stoebe, a native European aster that has been previously used in diversity-invasibility experiments in North America. We also conducted a field survey to explore the generality of the patterns generated from our experimental study. Both experimental and observational work revealed that increasing diversity reduced the performance of alien but not native invaders. Centaurea stoebe invading its native community performed poorly regardless of resident diversity, whereas in a parallel, previously published study conducted in North America, C. stoebe easily invaded low-diversity but not high-diversity assemblages. Our results suggest that diversity is an attribute of resident communities that makes them more or less susceptible to invasion by novel invasive alien but not native plant species.

Integrated carbon and chlorine isotope modeling: applications to chlorinated aliphatic hydrocarbons dechlorination.

PubMed

Jin, Biao; Haderlein, Stefan B; Rolle, Massimo

2013-02-05

We propose a self-consistent method to predict the evolution of carbon and chlorine isotope ratios during degradation of chlorinated hydrocarbons. The method treats explicitly the cleavage of isotopically different C-Cl bonds and thus considers, simultaneously, combined carbon-chlorine isotopologues. To illustrate the proposed modeling approach we focus on the reductive dehalogenation of chlorinated ethenes. We compare our method with the currently available approach, in which carbon and chlorine isotopologues are treated separately. The new approach provides an accurate description of dual-isotope effects regardless of the extent of the isotope fractionation and physical characteristics of the experimental system. We successfully applied the new approach to published experimental results on dehalogenation of chlorinated ethenes both in well-mixed systems and in situations where mass-transfer limitations control the overall rate of biodegradation. The advantages of our self-consistent dual isotope modeling approach proved to be most evident when isotope fractionation factors of carbon and chlorine differed significantly and for systems with mass-transfer limitations, where both physical and (bio)chemical transformation processes affect the observed isotopic values.

Experimental dermatophytosis in nude guinea pigs compared with infections in Pirbright White animals.

PubMed

Hänel, H; Braun, B; Löschhorn, K

1990-04-01

With this investigation we wanted to compare the suitability of two different strains of guinea pigs to evaluate topical antifungals after experimental Trichophyton mentagrophytes infection. The "hairless"-strain was compared with the hairy Pirbright White strain. The infection areas were treated with a skin retention test (application before infection) and two sets of therapy tests (application after infection). In the retention test the different antimycotic compounds led to better gradations. Also, in the two sets of therapy tests the gradations among the compounds were more clearly and more comparable to published results of clinical trials. In the histological investigations the infections in the "hairless" animals developed in a way which is known from dermatophytoses in human skin. In the Pirbright White strain, however, due to the adjacent hair roots, a marked inflammatory reaction of the tissue persisted for 3 weeks which is not observed on human skin of the trunk and extremities. We, therefore, consider the "hairless" strain of guinea pigs to be more suitable than hairy animals for the comparison of topical antimycotics.

Metabolic Compartmentation – A System Level Property of Muscle Cells

PubMed Central

Saks, Valdur; Beraud, Nathalie; Wallimann, Theo

2008-01-01

Problems of quantitative investigation of intracellular diffusion and compartmentation of metabolites are analyzed. Principal controversies in recently published analyses of these problems for the living cells are discussed. It is shown that the formal theoretical analysis of diffusion of metabolites based on Fick's equation and using fixed diffusion coefficients for diluted homogenous aqueous solutions, but applied for biological systems in vivo without any comparison with experimental results, may lead to misleading conclusions, which are contradictory to most biological observations. However, if the same theoretical methods are used for analysis of actual experimental data, the apparent diffusion constants obtained are orders of magnitude lower than those in diluted aqueous solutions. Thus, it can be concluded that local restrictions of diffusion of metabolites in a cell are a system-level properties caused by complex structural organization of the cells, macromolecular crowding, cytoskeletal networks and organization of metabolic pathways into multienzyme complexes and metabolons. This results in microcompartmentation of metabolites, their channeling between enzymes and in modular organization of cellular metabolic networks. The perspectives of further studies of these complex intracellular interactions in the framework of Systems Biology are discussed. PMID:19325782

A novel solution for hydroxylated PAHs removal by oxidative coupling reaction using Mn oxide.

PubMed

Kang, Ki-Hoon; Lim, Dong-Min; Shin, Hyun-Sang

2008-01-01

In this study, removals of 1-naphthol by oxidative-coupling reaction using birnessite, one of the natural Mn oxides present in soil, was investigated in various experimental conditions (reaction time, Mn oxide loadings, pH). The removal efficiency of 1-naphthol by birnessite was high in all the experimental conditions, and UV-visible and mass spectrometric analyses on the supernatant after reaction confirmed that the reaction products were oligomers formed by oxidative-coupling reaction. Pseudo-first order rate constants, k, for the oxidative transformation of 1-naphthol by birnessite was derived from the kinetic experiments under various amounts of birnessite loadings, and using the observed pseudo-first order rate constants with respect to birnessite loadings, the surface area normalised specific rate constant, k(surf), was also determined to be 9.3 x 10(-4) (L/m(2).min) for 1-naphthol. In addition, the oxidative transformation of 1-naphthol was found to be dependent on solution pH, and the pseudo-first order rate constants were increased from 0.129 at pH 10 to 0.187 at pH 4. (c) IWA Publishing 2008.

The potential benefits of repeated measure experiments for fish disease-challenge host-pathogen investigations.

PubMed

Hall, L Malcolm; Collins, Catherine; Collet, Bertrand

2018-02-02

The utility of molecular response data arising from in-vivo single and repeated measure fish disease-challenge experiments is compared. An in-silico 'experiment' involving the generation of two imaginary immune-molecule quantity response profiles over time for individual animals was carried out. Daily 'observed' molecule quantities were drawn from the 'known' individual response profiles to mimic the results of single and repeated measurement. The results indicate that repeated measure experiments are required to infer individual level response profiles, and that these experiments also provide more accurate summary statistics and data more suited to inferring the dependent ordering of the molecular response. Additionally repeated measure experiments utilise fewer animals than single measure experiments. These results are described alongside a discussion of experimental methodological issues pertinent to the adoption of aquatic animal repeated measure experimental designs. We conclude that investigators need to take particular care when making inferences from single measure experiments and that serious consideration should be given to using repeated measure experiments for in-vivo fish disease-challenge investigations. Crown Copyright © 2018. Published by Elsevier Ltd. All rights reserved.

Replication, lies and lesser-known truths regarding experimental design in environmental microbiology.

PubMed

Lennon, Jay T

2011-06-01

A recent analysis revealed that most environmental microbiologists neglect replication in their science (Prosser, 2010). Of all peer-reviewed papers published during 2009 in the field's leading journals, slightly more than 70% lacked replication when it came to analyzing microbial community data. The paucity of replication is viewed as an 'endemic' and 'embarrassing' problem that amounts to 'bad science', or worse yet, as the title suggests, lying (Prosser, 2010). Although replication is an important component of experimental design, it is possible to do good science without replication. There are various quantitative techniques - some old, some new - that, when used properly, will allow environmental microbiologists to make strong statistical conclusions from experimental and comparative data. Here, I provide examples where unreplicated data can be used to test hypotheses and yield novel information in a statistically robust manner. © 2011 Society for Applied Microbiology and Blackwell Publishing Ltd.

Screening Mammography & Breast Cancer Mortality: Meta-Analysis of Quasi-Experimental Studies

PubMed Central

Irvin, Veronica L.; Kaplan, Robert M.

2014-01-01

Background The magnitude of the benefit associated with screening has been debated. We present a meta-analysis of quasi-experimental studies on the effects of mammography screening. Methods We searched MEDLINE/PubMed and Embase for articles published through January 31, 2013. Studies were included if they reported: 1) a population-wide breast cancer screening program using mammography with 5+ years of data post-implementation; 2) a comparison group with equal access to therapies; and 3) breast cancer mortality. Studies excluded were: RCTs, case-control, or simulation studies. We defined quasi-experimental as studies that compared either geographical, historical or birth cohorts with a screening program to an equivalent cohort without a screening program. Meta-analyses were conducted in Stata using the metan command, random effects. Meta-analyses were conducted separately for ages screened: under 50, 50 to 69 and over 70 and weighted by population and person-years. Results Among 4,903 published papers that were retrieved, 19 studies matched eligibility criteria. Birth cohort studies reported a significant benefit for women screened

The effect of personality traits and psychosocial training on burnout syndrome among healthcare students.

PubMed

Skodova, Zuzana; Lajciakova, Petra

2013-11-01

The aims of this paper were to explore the influence of personality factors on student burnout syndrome and to explore the effect of psychosocial training on burnout and personality predictors among university students in health care professions. A quasi-experimental pre-test/post-test design was used to evaluate the effect of psychosocial training. A sample of 111 university students were divided into experimental and control groups (average age 20.7 years, SD=2.8 years; 86.1% females). The School Burnout Inventory (SBI), Sense of Coherence (SOC) questionnaire, and Rosenberg's Self-esteem scale were employed. Linear regression and analysis of variance were applied for statistical analysis. The results show that socio-psychological training had a positive impact on the level of burnout and on personality factors that are related to burnout. After completing the training, the level of burnout in the experimental group significantly decreased (95% confidence interval: 0.93, 9.25), and no significant change was observed in the control group. Furthermore, respondents' sense of coherence increased in the experimental group (95% confidence interval: -9.11, 2.64), but there were no significant changes in respondents' self-esteem levels in either group. Psychosocial training positively influenced burnout among students in health care professions. Because the coping strategies that were used during the study are similar to effective work coping strategies, psychosocial training can be considered to be an effective tool to prevent burnout in the helping professions. Copyright © 2013. Published by Elsevier Ltd.

[The participation of patients with dementia in individualised intervention plan meetings: the impact on their well-being and the quality of life].

PubMed

Villar, Feliciano; Vila-Miravent, Josep; Celdrán, Montserrat; Fernández, Elena

2013-01-01

An individualised intervention plan (IIP) offers a new paradigm in the care of the elderly with dementia, with the aim of increasing their quality of life through personalisation, respect for their freedom, and their participation in the decisions that affect their lives. To evaluate the impact of the residential home patient with dementia and their quality of care when they take part in the interdisciplinary meeting in which their care plan is decided. A total of 52 elderly patients with dementia took part in the study. They were distributed into two groups, one experimental (37 residents) and another control (15 residents). The Dementia Care Mapping (DCM) tool was used to assess the well-being and quality of care of the residents. This tool was used twice, before and after the intervention. The well-being of the resident, evaluated using the DCM, was similar before and after the intervention in the experimental group. No differences were observed either on comparing the control and experimental groups. However, some indicators of carer behaviour were different before and after the intervention, and when the control and experimental group were compared. The inclusion of elderly persons with dementia in their IIP meeting had a positive effect in the interaction of the staff with the residents, but not on the well-being of the resident. Copyright © 2012 SEGG. Published by Elsevier Espana. All rights reserved.

Current hypotheses for the evolution of sex and recombination.

PubMed

Hartfield, Matthew; Keightley, Peter D

2012-06-01

The evolution of sex is one of the most important and controversial problems in evolutionary biology. Although sex is almost universal in higher animals and plants, its inherent costs have made its maintenance difficult to explain. The most famous of these is the twofold cost of males, which can greatly reduce the fecundity of a sexual population, compared to a population of asexual females. Over the past century, multiple hypotheses, along with experimental evidence to support these, have been put forward to explain widespread costly sex. In this review, we outline some of the most prominent theories, along with the experimental and observational evidence supporting these. Historically, there have been 4 classes of theories: the ability of sex to fix multiple novel advantageous mutants (Fisher-Muller hypothesis); sex as a mechanism to stop the build-up of deleterious mutations in finite populations (Muller's ratchet); recombination creating novel genotypes that can resist infection by parasites (Red Queen hypothesis); and the ability of sex to purge bad genomes if deleterious mutations act synergistically (mutational deterministic hypothesis). Current theoretical and experimental evidence seems to favor the hypothesis that sex breaks down selection interference between new mutants, or it acts as a mechanism to shuffle genotypes in order to repel parasitic invasion. However, there is still a need to collect more data from natural populations and experimental studies, which can be used to test different hypotheses. © 2012 ISZS, Blackwell Publishing and IOZ/CAS.

An experimental and detailed chemical kinetic modeling study of hydrogen and syngas mixture oxidation at elevated pressures

DOE PAGES

Keromnes, Alan; Metcalfe, Wayne K.; Heufer, Karl A.; ...

2013-03-12

The oxidation of syngas mixtures was investigated experimentally and simulated with an updated chemical kinetic model. Ignition delay times for H 2/CO/O 2/N 2/Ar mixtures have been measured using two rapid compression machines and shock tubes at pressures from 1 to 70 bar, over a temperature range of 914–2220 K and at equivalence ratios from 0.1 to 4.0. Results show a strong dependence of ignition times on temperature and pressure at the end of the compression; ignition delays decrease with increasing temperature, pressure, and equivalence ratio. The reactivity of the syngas mixtures was found to be governed by hydrogen chemistrymore » for CO concentrations lower than 50% in the fuel mixture. For higher CO concentrations, an inhibiting effect of CO was observed. Flame speeds were measured in helium for syngas mixtures with a high CO content and at elevated pressures of 5 and 10 atm using the spherically expanding flame method. A detailed chemical kinetic mechanism for hydrogen and H 2/CO (syngas) mixtures has been updated, rate constants have been adjusted to reflect new experimental information obtained at high pressures and new rate constant values recently published in the literature. Experimental results for ignition delay times and flame speeds have been compared with predictions using our newly revised chemical kinetic mechanism, and good agreement was observed. In the mechanism validation, particular emphasis is placed on predicting experimental data at high pressures (up to 70 bar) and intermediate- to high-temperature conditions, particularly important for applications in internal combustion engines and gas turbines. The reaction sequence H 2 + HO˙ 2 ↔ H˙+H 2O 2 followed by H 2O 2(+M) ↔ O˙H+O˙H(+M) was found to play a key role in hydrogen ignition under high-pressure and intermediate-temperature conditions. The rate constant for H 2+HO˙ 2 showed strong sensitivity to high-pressure ignition times and has considerable uncertainty, based on literature values. As a result, a rate constant for this reaction is recommended based on available literature values and on our mechanism validation.« less

Effects of Video Game Training on Measures of Selective Attention and Working Memory in Older Adults: Results from a Randomized Controlled Trial.

PubMed

Ballesteros, Soledad; Mayas, Julia; Prieto, Antonio; Ruiz-Marquez, Eloísa; Toril, Pilar; Reales, José M

2017-01-01

Video game training with older adults potentially enhances aspects of cognition that decline with aging and could therefore offer a promising training approach. Although, previous published studies suggest that training can produce transfer, many of them have certain shortcomings. This randomized controlled trial (RCT; Clinicaltrials.gov ID: NCT02796508) tried to overcome some of these limitations by incorporating an active control group and the assessment of motivation and expectations. Seventy-five older volunteers were randomly assigned to the experimental group trained for 16 sessions with non-action video games from Lumosity , a commercial platform (http://www.lumosity.com/) or to an active control group trained for the same number of sessions with simulation strategy games. The final sample included 55 older adults (30 in the experimental group and 25 in the active control group). Participants were tested individually before and after training to assess working memory (WM) and selective attention and also reported their perceived improvement, motivation and engagement. The results showed improved performance across the training sessions. The main results were: (1) the experimental group did not show greater improvements in measures of selective attention and working memory than the active control group (the opposite occurred in the oddball task); (2) a marginal training effect was observed for the N -back task, but not for the Stroop task while both groups improved in the Corsi Blocks task. Based on these results, one can conclude that training with non-action games provide modest benefits for untrained tasks. The effect is not specific for that kind of training as a similar effect was observed for strategy video games. Groups did not differ in motivation, engagement or expectations.

Radiocesium interaction with clay minerals: Theory and simulation advances Post-Fukushima.

PubMed

Okumura, Masahiko; Kerisit, Sebastien; Bourg, Ian C; Lammers, Laura N; Ikeda, Takashi; Sassi, Michel; Rosso, Kevin M; Machida, Masahiko

2018-04-14

Insights at the microscopic level of the process of radiocesium adsorption and interaction with clay mineral particles have improved substantially over the past several years, triggered by pressing social issues such as management of huge amounts of waste soil accumulated after the Fukushima Dai-ichi nuclear power plant accident. In particular, computer-based molecular modeling supported by advanced hardware and algorithms has proven to be a powerful approach. Its application can now generally encompass the full complexity of clay particle adsorption sites from basal surfaces to interlayers with inserted water molecules, to edges including fresh and weathered frayed ones. On the other hand, its methodological schemes are now varied from traditional force-field molecular dynamics on large-scale realizations composed of many thousands of atoms including water molecules to first-principles methods on smaller models in rather exacting fashion. In this article, we overview new understanding enabled by simulations across methodological variations, focusing on recent insights that connect with experimental observations, namely: 1) the energy scale for cesium adsorption on the basal surface, 2) progress in understanding the structure of clay edges, which is difficult to probe experimentally, 3) cesium adsorption properties at hydrated interlayer sites, 4) the importance of the size relationship between the ionic radius of cesium and the interlayer distance at frayed edge sites, 5) the migration of cesium into deep interlayer sites, and 6) the effects of nuclear decay of radiocesium. Key experimental observations that motivate these simulation advances are also summarized. Furthermore, some directions toward future solutions of waste soil management are discussed based on the obtained microscopic insights. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Effects of Video Game Training on Measures of Selective Attention and Working Memory in Older Adults: Results from a Randomized Controlled Trial

PubMed Central

Ballesteros, Soledad; Mayas, Julia; Prieto, Antonio; Ruiz-Marquez, Eloísa; Toril, Pilar; Reales, José M.

2017-01-01

Video game training with older adults potentially enhances aspects of cognition that decline with aging and could therefore offer a promising training approach. Although, previous published studies suggest that training can produce transfer, many of them have certain shortcomings. This randomized controlled trial (RCT; Clinicaltrials.gov ID: NCT02796508) tried to overcome some of these limitations by incorporating an active control group and the assessment of motivation and expectations. Seventy-five older volunteers were randomly assigned to the experimental group trained for 16 sessions with non-action video games from Lumosity, a commercial platform (http://www.lumosity.com/) or to an active control group trained for the same number of sessions with simulation strategy games. The final sample included 55 older adults (30 in the experimental group and 25 in the active control group). Participants were tested individually before and after training to assess working memory (WM) and selective attention and also reported their perceived improvement, motivation and engagement. The results showed improved performance across the training sessions. The main results were: (1) the experimental group did not show greater improvements in measures of selective attention and working memory than the active control group (the opposite occurred in the oddball task); (2) a marginal training effect was observed for the N-back task, but not for the Stroop task while both groups improved in the Corsi Blocks task. Based on these results, one can conclude that training with non-action games provide modest benefits for untrained tasks. The effect is not specific for that kind of training as a similar effect was observed for strategy video games. Groups did not differ in motivation, engagement or expectations. PMID:29163136

The incidence of root microcracks caused by 3 different single-file systems versus the ProTaper system.

PubMed

Liu, Rui; Hou, Ben Xiang; Wesselink, Paul R; Wu, Min-Kai; Shemesh, Hagay

2013-08-01

The aim of this study was to compare the incidence of root cracks observed at the apical root surface and/or in the canal wall after canal instrumentation with 3 single-file systems and the ProTaper system (Dentsply Maillefer, Ballaigues, Switzerland). One hundred mandibular incisors were selected. Twenty control teeth were coronally flared with Gates-Glidden drills (Dentsply Maillefer). No further preparation was made. The other 80 teeth were mounted in resin blocks with simulated periodontal ligaments, and the apex was exposed. They were divided into 4 experimental groups (n = 20); the root canals were first coronally flared with Gates-Glidden drills and then instrumented to the full working length with the ProTaper, OneShape (Micro-Mega, Besancon, France), Reciproc (VDW, Munich, Germany), or the Self-Adjusting File (ReDent-Nova, Ra'anana, Israel). The apical root surface and horizontal sections 2, 4, and 6 mm from the apex were observed under a microscope. The presence of cracks was noted. The chi-square test was performed to compare the appearance of cracked roots between the experimental groups. No cracks were found in the control teeth and teeth instrumented with the Self-Adjusting File. Cracks were found in 10 of 20 (50%), 7 of 20 (35%), and 1 of 20 (5%) teeth after canal instrumentation with the ProTaper, OneShape, and Reciproc files, respectively. The difference between the experimental groups was statistically significant (P < .001). Nickel-titanium instruments may cause cracks on the apical root surface or in the canal wall; the Self-Adjusting File and Reciproc files caused less cracks than the ProTaper and OneShape files. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

The Importance of Non-accessible Crosslinks and Solvent Accessible Surface Distance in Modeling Proteins with Restraints From Crosslinking Mass Spectrometry*

PubMed Central

Bullock, Joshua Matthew Allen; Schwab, Jannik; Thalassinos, Konstantinos; Topf, Maya

2016-01-01

Crosslinking mass spectrometry (XL-MS) is becoming an increasingly popular technique for modeling protein monomers and complexes. The distance restraints garnered from these experiments can be used alone or as part of an integrative modeling approach, incorporating data from many sources. However, modeling practices are varied and the difference in their usefulness is not clear. Here, we develop a new scoring procedure for models based on crosslink data—Matched and Nonaccessible Crosslink score (MNXL). We compare its performance with that of other commonly-used scoring functions (Number of Violations and Sum of Violation Distances) on a benchmark of 14 protein domains, each with 300 corresponding models (at various levels of quality) and associated, previously published, experimental crosslinks (XLdb). The distances between crosslinked lysines are calculated either as Euclidean distances or Solvent Accessible Surface Distances (SASD) using a newly-developed method (Jwalk). MNXL takes into account whether a crosslink is nonaccessible, i.e. an experimentally observed crosslink has no corresponding SASD in a model due to buried lysines. This metric alone is shown to have a significant impact on modeling performance and is a concept that is not considered at present if only Euclidean distances are used. Additionally, a comparison between modeling with SASD or Euclidean distance shows that SASD is superior, even when factoring out the effect of the nonaccessible crosslinks. Our benchmarking also shows that MNXL outperforms the other tested scoring functions in terms of precision and correlation to Cα-RMSD from the crystal structure. We finally test the MNXL at different levels of crosslink recovery (i.e. the percentage of crosslinks experimentally observed out of all theoretical ones) and set a target recovery of ∼20% after which the performance plateaus. PMID:27150526

Up-regulating the abscisic acid inactivation gene ZmABA8ox1b contributes to seed germination heterosis by promoting cell expansion.

PubMed

Li, Yangyang; Wang, Cheng; Liu, Xinye; Song, Jian; Li, Hongjian; Sui, Zhipeng; Zhang, Ming; Fang, Shuang; Chu, Jinfang; Xin, Mingming; Xie, Chaojie; Zhang, Yirong; Sun, Qixin; Ni, Zhongfu

2016-04-01

Heterosis has been widely used in agriculture, but the underlying molecular principles are still largely unknown. During seed germination, we observed that maize (Zea mays) hybrid B73/Mo17 was less sensitive than its parental inbred lines to exogenous abscisic acid (ABA), and endogenous ABA content in hybrid embryos decreased more rapidly than in the parental inbred lines. ZmABA8ox1b, an ABA inactivation gene, was consistently more highly up-regulated in hybrid B73/Mo17 than in its parental inbred lines at early stages of seed germination. Moreover, ectopic expression of ZmABA8ox1b obviously promoted seed germination in Arabidopsis Remarkably, microscopic observation revealed that cell expansion played a major role in the ABA-mediated maize seed germination heterosis, which could be attributed to the altered expression of cell wall-related genes. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Hydrodynamic and Chemical Factors in Clogging by Montmorillonite in Porous Media

PubMed Central

Mays, David C.; Hunt, James R.

2008-01-01

Clogging by colloid deposits is important in water treatment filters, groundwater aquifers, and petroleum reservoirs. The complexity of colloid deposition and deposit morphology preclude models based on first principles, so this study extends an empirical approach to quantify clogging using a simple, one-parameter model. Experiments were conducted with destabilized suspensions of sodium- and calcium-montmorillonite to quantify the hydrodynamic and chemical factors important in clogging. Greater clogging is observed at slower fluid velocity, consistent with previous investigations. However, calcium-montmorillonite causes one order of magnitude less clogging per mass of deposited particles compared to sodium-montmorillonite or a previously published summary of clogging in model granular media. Steady state conditions, in which the permeability and the quantity of deposited material are both constant, were not observed, even though the experimental conditions were optimized for that purpose. These results indicate that hydrodynamic aspects of clogging by these natural materials are consistent with those of simplified model systems, and they demonstrate significant chemical effects on clogging for fully destabilized montmorillonite clay. PMID:17874771

Relating brain signal variability to knowledge representation.

PubMed

Heisz, Jennifer J; Shedden, Judith M; McIntosh, Anthony R

2012-11-15

We assessed the hypothesis that brain signal variability is a reflection of functional network reconfiguration during memory processing. In the present experiments, we use multiscale entropy to capture the variability of human electroencephalogram (EEG) while manipulating the knowledge representation associated with faces stored in memory. Across two experiments, we observed increased variability as a function of greater knowledge representation. In Experiment 1, individuals with greater familiarity for a group of famous faces displayed more brain signal variability. In Experiment 2, brain signal variability increased with learning after multiple experimental exposures to previously unfamiliar faces. The results demonstrate that variability increases with face familiarity; cognitive processes during the perception of familiar stimuli may engage a broader network of regions, which manifests as higher complexity/variability in spatial and temporal domains. In addition, effects of repetition suppression on brain signal variability were observed, and the pattern of results is consistent with a selectivity model of neural adaptation. Crown Copyright © 2012. Published by Elsevier Inc. All rights reserved.

An "Epeleptick" bondswoman: fits, slavery, and power in the antebellum South.

PubMed

Boster, Dea H

2009-01-01

Epilepsy, as nineteenth-century observers understood the disease construct, was a feared diagnosis associated with insanity and uncontrollability. Cases of epileptic fits in slaves-whether they were considered genuine or feigned- highlighted deep struggles among white masters, physicians, and slaves themselves over the control of African American bodies. Some slaves who experienced fits were subjected to prolonged experimental treatments at the hands of physicians and white masters. Although Southern medical sources largely ignored the connection between epilepsy and trauma in slaves, abolitionists and ex-slave narratives published in the North used epilepsy as a representation of the institution's cruelty. Some white observers thought that slaves with epilepsy were prone to malingering; epileptic fits were also a tool of slave resistance and had a significant role in slave sale negotiations. I use the case study of a fifteen-year-old bondswoman in Virginia, diagnosed with epilepsy in 1843, to illustrate the significance of the disease in the lives of African American slaves.

Selective effects of explanation on learning during early childhood.

PubMed

Legare, Cristine H; Lombrozo, Tania

2014-10-01

Two studies examined the specificity of effects of explanation on learning by prompting 3- to 6-year-old children to explain a mechanical toy and comparing what they learned about the toy's causal and non-causal properties with children who only observed the toy, both with and without accompanying verbalization. In Study 1, children were experimentally assigned to either explain or observe the mechanical toy. In Study 2, children were classified according to whether the content of their response to an undirected prompt involved explanation. Dependent measures included whether children understood the toy's functional-mechanical relationships, remembered perceptual features of the toy, effectively reconstructed the toy, and (for Study 2) generalized the function of the toy when constructing a new one. Results demonstrate that across age groups, explanation promotes causal learning and generalization but does not improve (and in younger children can even impair) memory for causally irrelevant perceptual details. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Hydrodynamic and chemical factors in clogging by montmorillonite in porous media.

PubMed

Mays, David C; Hunt, James R

2007-08-15

Clogging by colloid deposits is important in water treatment filters, groundwater aquifers, and petroleum reservoirs. The complexity of colloid deposition and deposit morphology preclude models based on first principles, so this study extends an empirical approach to quantify clogging using a simple, one-parameter model. Experiments were conducted with destabilized suspensions of sodium- and calcium-montmorillonite to quantify the hydrodynamic and chemical factors important in clogging. Greater clogging is observed at slower fluid velocity, consistent with previous investigations. However, calcium-montmorillonite causes 1 order of magnitude less clogging per mass of deposited particles compared to sodium-montmorillonite or a previously published summary of clogging in model granular media. Steady-state conditions, in which the permeability and the quantity of deposited material are both constant, were not observed, even though the experimental conditions were optimized for that purpose. These results indicate that hydrodynamic aspects of clogging by these natural materials are consistent with those of simplified model systems, and they demonstrate significant chemical effects on clogging for fully destabilized montmorillonite clay.

Asymmetric dual-loop feedback to suppress spurious tones and reduce timing jitter in self-mode-locked quantum-dash lasers emitting at 155 μm

NASA Astrophysics Data System (ADS)

Asghar, Haroon; McInerney, John G.

2017-09-01

We demonstrate an asymmetric dual-loop feedback scheme to suppress external cavity side-modes induced in self-mode-locked quantum-dash lasers with conventional single and dual-loop feedback. In this letter, we achieved optimal suppression of spurious tones by optimizing the length of second delay time. We observed that asymmetric dual-loop feedback, with large (~8x) disparity in cavity lengths, eliminates all external-cavity side-modes and produces flat RF spectra close to the main peak with low timing jitter compared to single-loop feedback. Significant reduction in RF linewidth and reduced timing jitter was also observed as a function of increased second feedback delay time. The experimental results based on this feedback configuration validate predictions of recently published numerical simulations. This interesting asymmetric dual-loop feedback scheme provides simplest, efficient and cost effective stabilization of side-band free optoelectronic oscillators based on mode-locked lasers.

Optimization of fluorimetric lipid membrane biosensor sensitivity through manipulation of membrane structure and nitrobenzoxadiazole dipalmitoylphosphatidylethanolamine concentration

NASA Astrophysics Data System (ADS)

Shrive, Jason D. A.; Krull, Ulrich J.

1995-01-01

In the work reported here, surface concentrations of 0.027 and 0.073 molecules nm-2 of the fluorescent membrane probe molecule nitrobenzoxadiazole dipalmitoylphosphatidylethanolamine (NBD-PE) were shown to yield optimum sensitivity for fluorimetric transduction of membrane structural perturbations for lipid membrane-based biosensor development. These optima were obtained through correlation of experimental data with theoretical predictions of optimum surface concentrations based on a model for NBD-PE self quenching previously published by our group. It was also determined that membrane structural heterogeneity improves the sensitivity of NBD-PE labeled membrane transducers. Together with fluorescence microscopy, observations of surface potential change upon compression or expansion of phosphatidylcholine (PC)/phosphatidic acid (PA) monolayers were used to qualitatively indicate the degree of structural heterogeneity in these membranes. It was determined that sub-microscopic domains must exist in microscopically homogeneous egg PC/egg PA membranes in order to facilitate the observed NBD-PE self-quenching responses upon alteration of bulk pH and therefore, membrane surface electrostatics and structure.

Rapid bursts and slow declines: on the possible evolutionary trajectories of enzymes.

PubMed

Newton, Matilda S; Arcus, Vickery L; Patrick, Wayne M

2015-06-06

The evolution of enzymes is often viewed as following a smooth and steady trajectory, from barely functional primordial catalysts to the highly active and specific enzymes that we observe today. In this review, we summarize experimental data that suggest a different reality. Modern examples, such as the emergence of enzymes that hydrolyse human-made pesticides, demonstrate that evolution can be extraordinarily rapid. Experiments to infer and resurrect ancient sequences suggest that some of the first organisms present on the Earth are likely to have possessed highly active enzymes. Reconciling these observations, we argue that rapid bursts of strong selection for increased catalytic efficiency are interspersed with much longer periods in which the catalytic power of an enzyme erodes, through neutral drift and selection for other properties such as cellular energy efficiency or regulation. Thus, many enzymes may have already passed their catalytic peaks. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Delivering Sound Energy along an Arbitrary Convex Trajectory

PubMed Central

Zhao, Sipei; Hu, Yuxiang; Lu, Jing; Qiu, Xiaojun; Cheng, Jianchun; Burnett, Ian

2014-01-01

Accelerating beams have attracted considerable research interest due to their peculiar properties and various applications. Although there have been numerous research on the generation and application of accelerating light beams, few results have been published on the generation of accelerating acoustic beams. Here we report on the experimental observation of accelerating acoustic beams along arbitrary convex trajectories. The desired trajectory is projected to the spatial phase profile on the boundary which is discretized and sampled spatially. The sound field distribution is formulated with the Green function and the integral equation method. Both the paraxial and the non-paraxial regimes are examined and observed in the experiments. The effect of obstacle scattering in the sound field is also investigated and the results demonstrate that the approach is robust against obstacle scattering. The realization of accelerating acoustic beams will have an impact on various applications where acoustic information and energy are required to be delivered along an arbitrary convex trajectory. PMID:25316353

A study on the electronic spectra of some 2-azidobenzothiazoles, TD-DFT treatment.

PubMed

Abu-Eittah, Rafie H; El-Taher, Sabry; Hassan, Walid; Noamaan, Mahmoud

2015-12-05

The electronic absorption spectra of some 2-azidobenzothiazoles were measured in different solvents. The effects of solvent and substitution on the spectra were investigated. Substitution by a bromine atom and by a nitro group have significant effects on both band maxima and band intensity. Correlation between the spectra of the studied compounds and the corresponding hydrocarbons proved to be weak, whereas the correlation between the observed spectra and those calculated is adequate. Theoretical treatment of the ultraviolet spectra of the studied compounds was carried out by using the TD-DFT procedures, at the B3LYP level and the 6-311+G(∗∗) basis sets, the results compared well with the experimental values. The computed molecular orbitals of the ground state indicate that some orbitals are "localized-π" or "localized σ" molecular orbitals while the others are delocalized orbitals. The calculated functions of the excited states lead to an accurate assignment of the bands observed in the spectra. Copyright © 2015. Published by Elsevier B.V.

Terahertz spectra of l-phenylalanine and its monohydrate.

PubMed

Pan, Tingting; Li, Shaoping; Zou, Tao; Yu, Zheng; Zhang, Bo; Wang, Chenyang; Zhang, Jianbing; He, Mingxia; Zhao, Hongwei

2017-05-05

The low-frequency vibrational property of l-phenylalanine (l-Phe) and l-phenylalanine monohydrate (l-Phe·H 2 O) has been investigated by terahertz time-domain spectroscopy (THz-TDS) at room and low temperature ranging from 0.5 to 4.5THz. Distinctive THz absorption spectra of the two compounds were observed. Density functional theory (DFT) calculations based on the crystal structures have been performed to simulate the vibrational modes of l-Phe and l-Phe·H 2 O and the results agree well with the experimental observations. The study indicates that the characterized features of l-Phe mainly originate from the collective vibration of molecules. And the characterized features of l-Phe·H 2 O mainly come from hydrogen bond interactions between l-Phe and water molecules. l-Phe and l-Phe·H 2 O were also verified by differential scanning calorimetry and thermogravimetry (DSC-TG) and powder X-ray diffraction (PXRD) examinations. Copyright © 2017. Published by Elsevier B.V.

Assessment of lubricated contacts: Mechanisms of scuffing and scoring

NASA Technical Reports Server (NTRS)

Dyson, A.; Wedeven, L. D.

1983-01-01

Scoring and scuffing are defined as two distinct but related forms of failure of hardened ferrous components lubricated by liquids. Experimental observations of these phenomena are described, and criteria for scoring and scuffing are discussed. The mechanisms proposed by various authors to explain these observations are enumerated. The view presented here is that, under conditions yet to be defined, scoring is a gradual breakdown of the lubrication of interacting asperities, such lubrication being boundary or microelastohydrodynamic in nature, or a mixture of the two. The final scuffing stage represents a breakdown of the main elastohydrodynamic system, but this may be triggered by the deterioration in surface topography as a result of scoring. An extension of published theoretical treatment of elastohydrodynamic breakdown is proposed, and a critical experiment to assess the importance of edge effects in band contacts is suggested. The practical implications of the proposed mechanism are reviewed, and recommendations for further work are made. A possible thermal instability mechanism for the breakdown of boundary lubrication is outlined.

Hypersonic Experimental and Computational Capability, Improvement and Validation. Volume 2

NASA Technical Reports Server (NTRS)

Muylaert, Jean (Editor); Kumar, Ajay (Editor); Dujarric, Christian (Editor)

1998-01-01

The results of the phase 2 effort conducted under AGARD Working Group 18 on Hypersonic Experimental and Computational Capability, Improvement and Validation are presented in this report. The first volume, published in May 1996, mainly focused on the design methodology, plans and some initial results of experiments that had been conducted to serve as validation benchmarks. The current volume presents the detailed experimental and computational data base developed during this effort.

Dynamic Scattering Mode LCDs

NASA Astrophysics Data System (ADS)

Bahadur, Birendra

The following sections are included: * INTRODUCTION * CELL DESIGNING * EXPERIMENTAL OBSERVATIONS IN NEMATICS RELATED WITH DYNAMIC SCATTERING * Experimental Observations at D.C. Field and Electrode Effects * Experimental Observation at Low Frequency A.C. Fields * Homogeneously Aligned Nematic Regime * Williams Domains * Dynamic Scattering * Experimental Observation at High Frequency A.C. Field * Other Experimental Observations * THEORETICAL INTERPRETATIONS * Felici Model * Carr-Helfrich Model * D.C. Excitation * Dubois-Violette, de Gennes and Parodi Model * Low Freqency or Conductive Regime * High Frequency or Dielectric Regime * DYNAMIC SCATTERING IN SMECRIC A PHASE * ELECTRO-OPTICAL CHARACTERISTICS AND LIMITATIONS * Contrast Ratio vs. Voltage, Viewing Angle, Cell Gap, Wavelength and Temperature * Display Current vs. Voltage, Cell Gap and Temperature * Switching Time * Effect of Alignment * Effect of Conductivity, Temperature and Frequency * Addressing of DSM LCDs * Limitations of DSM LCDs * ACKNOWLEDGEMENTS * REFERENCES

Viral infection, proliferation, and hyperplasia of Hofbauer cells and absence of inflammation characterize the placental pathology of fetuses with congenital Zika virus infection.

PubMed

Schwartz, David A

2017-06-01

Attention is increasingly focused on the potential mechanism(s) for Zika virus infection to be transmitted from an infected mother to her fetus. This communication addresses current evidence for the role of the placenta in vertical transmission of the Zika virus. Placentas from second and third trimester fetuses with confirmed intrauterine Zika virus infection were examined with routine staining to determine the spectrum of pathologic changes. In addition, immunohistochemical staining for macrophages and nuclear proliferation antigens was performed. Viral localization was identified using RNA hybridization. These observations were combined with the recent published results of placental pathology to increase the strength of the pathology data. Results were correlated with published data from experimental studies of Zika virus infection in placental cells and chorionic villous explants. Placentas from fetuses with congenital Zika virus infection are concordant in not having viral-induced placental inflammation. Special stains reveal proliferation and prominent hyperplasia of placental stromal macrophages, termed Hofbauer cells, in the chorionic villi of infected placentas. Zika virus infection is present in Hofbauer cells from second and third trimester placentas. Experimental studies and placentae from infected fetuses reveal that the spectrum of placental cell types infected with the Zika virus is broader during the first trimester than later in gestation. Inflammatory abnormalities of the placenta are not a component of vertical transmission of the Zika virus. The major placental response in second and third trimester transplacental Zika virus infection is proliferation and hyperplasia of Hofbauer cells, which also demonstrate viral infection.

Shifts in microbial community structure and function in stream sediments during experimentally simulated riparian succession.

PubMed

Frossard, Aline; Gerull, Linda; Mutz, Michael; Gessner, Mark O

2013-05-01

Successional changes of terrestrial vegetation can profoundly influence stream ecosystem structure and function. We hypothesized that microbial enzyme production and community structure in stream beds depend on terrestrial litter inputs that reflect different stages of riparian succession. Outdoor experimental channels were supplied with leaf-litter of varying quantities and qualities to mimic litter supply during five successional stages: (1) an initial biofilm stage; (2) an open-land stage with grass litter; (3) a transitional stage with mixed grass and birch litter; (4) an early forest stage with birch litter; and (5) an advanced forest stage with 2.5 × the amount of birch litter. Mean potential activities of nitrogen- and phosphorus-acquiring enzymes in sediments (20.7 and 67.3 μmol g(-1) dry mass) were 12-70 times greater than those of carbon-acquiring enzymes (0.96-1.71 μmol g(-1) dry mass), with the former reduced 1.3-8.3-fold in channels with tree litter. These patterns could suggest gradually diminishing nutrient limitation of microbial activity during riparian succession, potentially linked both to an increasing supply by the added litter and to a lower nutrient demand as algal biomass and labile carbon supply by photosynthetic exudates declined. As the observed shifts in nutrient-acquiring enzymes were reflected in changes of sediment microbial communities, these results indicate that both the type and density of terrestrial vegetation control microbial community structure and function in stream sediments, particularly enzyme production related to nutrient cycling. © 2013 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

Percolation connectivity, pore size, and gas apparent permeability: Network simulations and comparison to experimental data

NASA Astrophysics Data System (ADS)

Li, M.; Tang, Y. B.; Bernabé, Y.; Zhao, J. Z.; Li, X. F.; Li, T.

2017-07-01

We modeled single-phase gas flow through porous media using percolation networks. Gas permeability is different from liquid permeability. The latter is only related to the geometry and topology of the pore space, while the former depends on the specific gas considered and varies with gas pressure. As gas pressure decreases, four flow regimes can be distinguished as viscous flow, slip flow, transition flow, and free molecular diffusion. Here we use a published conductance model presumably capable of predicting the flow rate of an arbitrary gas through a cylindrical pipe in the four regimes. We incorporated this model into pipe network simulations. We considered 3-D simple cubic, body-centered cubic, and face-centered cubic lattices, in which we varied the pipe radius distribution and the bond coordination number. Gas flow was simulated at different gas pressures. The simulation results showed that the gas apparent permeability kapp obeys an identical scaling law in all three lattices, kapp (z-zc)β, where the exponent β depends on the width of the pipe radius distribution, z is the mean coordination number, and zc its critical value at the percolation threshold. Surprisingly, (z-zc) had a very weak effect on the ratio of the apparent gas permeability to the absolute liquid permeability, kapp/kabs, suggesting that the Klinkenberg gas slippage correction factor is nearly independent of connectivity. We constructed models of kapp and kapp/kabs based on the observed power law and tested them by comparison with published experimental data on glass beads and other materials.

Design and Implementation of an Experimental Cataloging Advisor--Mapper.

ERIC Educational Resources Information Center

Ercegovac, Zorana; Borko, Harold

1992-01-01

Describes the design of an experimental computer-aided cataloging advisor, Mapper, that was developed to help novice users with the descriptive cataloging of single-sheet maps from U.S. publishers. The human-computer interface is considered, the use of HyperCard is discussed, the knowledge base is explained, and assistance screens are described.…

78 FR 54613 - Endangered and Threatened Wildlife and Plants; Proposed Revision to the Nonessential Experimental...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-05

... revise the existing nonessential experimental population designation of the Mexican wolf (Canis lupus... lupus baileyi), which also published in the Federal Register on June 13, 2013, should be submitted to... (Canis lupus baileyi) by listing it as endangered (78 FR 35664). FOR FURTHER INFORMATION CONTACT: Mexican...

Teaching Science Problem Solving: An Overview of Experimental Work.

ERIC Educational Resources Information Center

Taconis, R.; Ferguson-Hessler, M. G. M.; Broekkamp, H.

2001-01-01

Performs analysis on a number of articles published between 1985 and 1995 describing experimental research into the effectiveness of a wide variety of teaching strategies for science problem solving. Identifies 22 articles describing 40 experiments that met standards for meta-analysis. Indicates that few of the independent variables were found to…

How Sommerfeld extended Bohr's model of the atom (1913-1916)

NASA Astrophysics Data System (ADS)

Eckert, Michael

2014-04-01

Sommerfeld's extension of Bohr's atomic model was motivated by the quest for a theory of the Zeeman and Stark effects. The crucial idea was that a spectral line is made up of coinciding frequencies which are decomposed in an applied field. In October 1914 Johannes Stark had published the results of his experimental investigation on the splitting of spectral lines in hydrogen (Balmer lines) in electric fields, which showed that the frequency of each Balmer line becomes decomposed into a multiplet of frequencies. The number of lines in such a decomposition grows with the index of the line in the Balmer series. Sommerfeld concluded from this observation that the quantization in Bohr's model had to be altered in order to allow for such decompositions. He outlined this idea in a lecture in winter 1914/15, but did not publish it. The First World War further delayed its elaboration. When Bohr published new results in autumn 1915, Sommerfeld finally developed his theory in a provisional form in two memoirs which he presented in December 1915 and January 1916 to the Bavarian Academy of Science. In July 1916 he published the refined version in the Annalen der Physik. The focus here is on the preliminary Academy memoirs whose rudimentary form is better suited for a historical approach to Sommerfeld's atomic theory than the finished Annalen-paper. This introductory essay reconstructs the historical context (mainly based on Sommerfeld's correspondence). It will become clear that the extension of Bohr's model did not emerge in a singular stroke of genius but resulted from an evolving process.

[Registration of observational studies: it is time to comply with the Declaration of Helsinki requirement].

PubMed

Dal-Ré, Rafael; Delgado, Miguel; Bolumar, Francisco

2015-01-01

Publication bias is a serious deficiency in the current system of disseminating the results of human research studies. Clinical investigators know that, from an ethical standpoint, they should prospectively register clinical trials in a public registry before starting them. In addition, it is believed that this approach will help to reduce publication bias. However, most studies conducted in humans are observational rather than experimental. It is estimated that less than 2% out of 2 million concluded or ongoing observational studies have been registered. The 2013 revision of the Declaration of Helsinki requires registration of any type of research study involving humans or identifiable samples or data. It is proposed that funding agencies, such as the Fondo de Investigaciones Sanitarias, as well as private companies, require preregistration of observational studies before providing funding. It is also proposed that Research Ethics Committees which, following Spanish regulation, have been using the Declaration as the framework for assessing the ethics of clinical trials with medicines since 1990, should follow the same provisions for the assessment of health-related observational studies: therefore, they should require prospective registration of studies before granting their final approval. This would allow observational study investigators to be educated in complying with an ethical requirement recently introduced in the most important ethical code for research involving humans. Copyright © 2014 SESPAS. Published by Elsevier Espana. All rights reserved.

Experimental intoxication of guinea pigs with Ipomoea carnea: behavioural and neuropathological alterations.

PubMed

Cholich, Luciana A; Márquez, Mercedes; Pumarola i Batlle, Martí; Gimeno, Eduardo J; Teibler, Gladys P; Rios, Elvio E; Acosta, Ofelia C

2013-12-15

Ipomoea carnea is a toxic plant that affects goats, with symptoms being characterised by nervous disorders and death. Swainsonine and calystegines are the principal toxic components isolated from I. carnea, which also yields lysergic acid derivatives. The aim of this study was to improve the clinical characterisation of experimental intoxication by I. carnea in guinea pigs through the evaluation of behavioural changes and to perform a thorough histopathological analysis of the affected CNS. Leaves of I. carnea were administered to guinea pigs. Open-field gait analysis and monoamine levels were measured. The poisoned animals exhibited increased vocalisation, lethargy, and a reduction in the locomotion frequency after the fourth week of intoxication, as demonstrated in the open-field test. Significant differences were observed in hind-limb gait width by the last week of intoxication. After 65 days, the guinea pigs were euthanised, necropsied, and examined using light and electron microscopy. At the end of the experiment, plasma serotonin decreased. In contrast, dopamine decreased, and noradrenaline increased in urine. Brain sections were evaluated with conventional histological methods and immunohistochemistry (IHC), as well as by transmission electron microscopy (TEM). Vacuoles were observed throughout the brain, but they were particularly prominent in the brainstem. In addition, there were PAS-negative regions, and the Nissl substance was dispersed or absent, which was confirmed with the Kluver-Barreda stain. Moderate microgliosis was observed by immunohistochemistry. In the medulla oblongata, numerous ubiquitin-positive spheroids together with neuronal degeneration were observed in the nucleus gracilis/cuneatus. Furthermore, vacuoles were observed in astrocytes, oligodendrocytes, and endothelial cells by TEM. Our results showed that the behavioural effects may have been caused by alterations in the brain in conjunction with changes in monoamine levels. This research confirms the utility of this model for studying the pathogenesis of plant-induced lysosomal storage diseases. Copyright © 2013. Published by Elsevier Ltd.

78 FR 21125 - Findings of Research Misconduct

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-09

... to the following publications and grant applications: Blood pre-published online on January 16, 2003 (``NEM'') Experimental Hematology 31:372-381, 2003 (``CMA'') Blood 97:147-153, 2001 (``ISB'') R01 CA89135-01A1 R01 HL73063-01 R01 HL79615-01 Blood pre-published online on January 16, 2003, has been retracted...

Modern Publishing Approach of Journal of Astronomy & Earth Sciences Education

NASA Astrophysics Data System (ADS)

Slater, Timothy F.

2015-01-01

Filling a needed scholarly publishing avenue for astronomy education researchers and earth science education researchers, the Journal of Astronomy & Earth Sciences Education - JAESE published its first volume and issue in 2014. The Journal of Astronomy & Earth Sciences Education - JAESE is a scholarly, peer-reviewed scientific journal publishing original discipline-based education research and evaluation, with an emphasis of significant scientific results derived from ethical observations and systematic experimentation in science education and evaluation. International in scope, JAESE aims to publish the highest quality and timely articles from discipline-based education research that advance understanding of astronomy and earth sciences education and are likely to have a significant impact on the discipline or on policy. Articles are solicited describing both (i) systematic science education research and (ii) evaluated teaching innovations across the broadly defined Earth & space sciences education, including the disciplines of astronomy, climate education, energy resource science, environmental science, geology, geography, agriculture, meteorology, planetary sciences, and oceanography education. The publishing model adopted for this new journal is open-access and articles appear online in GoogleScholar, ERIC, and are searchable in catalogs of 440,000 libraries that index online journals of its type. Rather than paid for by library subscriptions or by society membership dues, the annual budget is covered by page-charges paid by individual authors, their institutions, grants or donors: This approach is common in scientific journals, but is relatively uncommon in education journals. Authors retain their own copyright. The journal is owned by the Clute Institute of Denver, which owns and operates 17 scholarly journals and currently edited by former American Astronomical Society Education Officer Tim Slater, who is an endowed professor at the University of Wyoming and a Senior Scientist at the CAPER Center for Astronomy & Physics Education Research. More information about the journal and its policies are available online at http://www.JAESE.org

Publishing in the Refereed International Journal of Astronomy & Earth Sciences Education JAESE

NASA Astrophysics Data System (ADS)

Slater, Timothy F.

2015-08-01

Filling a needed scholarly publishing avenue for astronomy education researchers and earth science education researchers, the Journal of Astronomy & Earth Sciences Education- JAESE was first published in 2014. JAESE is a scholarly, peer-reviewed scientific journal publishing original discipline-based education research and evaluation, with an emphasis of significant scientific results derived from ethical observations and systematic experimentation in science education and evaluation. International in scope, JAESE aims to publish the highest quality and timely articles from discipline-based education research that advance understanding of astronomy and earth sciences education and are likely to have a significant impact on the discipline or on policy. Articles are solicited describing both (i) systematic science education research and (ii) evaluated teaching innovations across the broadly defined Earth & space sciences education, including the disciplines of astronomy, climate education, energy resource science, environmental science, geology, geography, agriculture, meteorology, planetary sciences, and oceanography education. The publishing model adopted for this new journal is open-access and articles appear online in GoogleScholar, ERIC, EBSCO, ProQuest, and NASA SAO/ADS and are searchable in catalogs of 440,000 libraries that index online journals of its type. Rather than paid for by library subscriptions or by society membership dues, the annual budget is covered by page-charges paid by individual authors, their institutions, grants or donors: This approach is common in scientific journals, but is relatively uncommon in education journals. Authors retain their own copyright. The journal is owned by the Clute Institute in the United States, which owns and operates 17 scholarly journals and currently edited by former American Astronomical Society Education Officer Tim Slater, who is an endowed professor at the University of Wyoming and a Senior Scientist at the CAPER Center for Astronomy & Physics Education Research. More information about the journal and its policies are available online at http://www.JAESE.org

Astrometric observations of comets and asteroids and subsequent orbital investigations

NASA Technical Reports Server (NTRS)

Mccrosky, R. E.; Marsden, B. G.

1986-01-01

During the past year some 500 observations were made on 66 nights and published on the MPCs (Minor Planet Circulars/Minor Planets and Comets). In addition, a handful of measurements of earlier plates were completed and published. 121 of the observations published referred to comets. Of special importance were observations of comets (P/Giacobini-Zinner and P/Halley) in connection with the NASA ICE and ESA Giotto missions, but a special effort was made to get good coverage of almost all of the observable comets. Observations were also made of (2060) Chiron and of the earth-approaching objects (1627) Ivar, (1866) Sisyphys, (1943) Anteros, (3362) 1984 QA, 1985 JA, PA, TB and WA, and 1986 DA and EB. 46 minor planets were given permanent numbers entirely as a result of the observations.

Reporting of Telehealth-Delivered Dietary Intervention Trials in Chronic Disease: Systematic Review.

PubMed

Warner, Molly M; Kelly, Jaimon T; Reidlinger, Dianne P; Hoffmann, Tammy C; Campbell, Katrina L

2017-12-11

Telehealth-delivered dietary interventions are effective for chronic disease management and are an emerging area of clinical practice. However, to apply interventions from the research setting in clinical practice, health professionals need details of each intervention component. The aim of this study was to evaluate the completeness of intervention reporting in published dietary chronic disease management trials that used telehealth delivery methods. Eligible randomized controlled trial publications were identified through a systematic review. The completeness of reporting of experimental and comparison interventions was assessed by two independent assessors using the Template for Intervention Description and Replication (TIDieR) checklist that consists of 12 items including intervention rationale, materials used, procedures, providers, delivery mode, location, when and how much intervention delivered, intervention tailoring, intervention modifications, and fidelity. Where reporting was incomplete, further information was sought from additional published material and through email correspondence with trial authors. Within the 37 eligible trials, there were 49 experimental interventions and 37 comparison interventions. One trial reported every TIDieR item for their experimental intervention. No publications reported every item for the comparison intervention. For the experimental interventions, the most commonly reported items were location (96%), mode of delivery (98%), and rationale for the essential intervention elements (96%). Least reported items for experimental interventions were modifications (2%) and intervention material descriptions (39%) and where to access them (20%). Of the 37 authors, 14 responded with further information, and 8 could not be contacted. Many details of the experimental and comparison interventions in telehealth-delivered dietary chronic disease management trials are incompletely reported. This prevents accurate interpretation of trial results and implementation of effective interventions in clinical practice. ©Molly M Warner, Jaimon T Kelly, Dianne P Reidlinger, Tammy C Hoffmann, Katrina L Campbell. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 11.12.2017.

Experimental calibration of silicon and oxygen isotope fractionations between quartz and water at 250°C by in situ microanalysis of experimental products and application to zoned low δ 30Si quartz overgrowths

DOE PAGES

Pollington, Anthony D.; Kozdon, Reinhard; Anovitz, Lawrence M.; ...

2015-12-01

The interpretation of silicon isotope data for quartz is hampered by the lack of experimentally determined fractionation factors between quartz and fluid. Further, there is a large spread in published oxygen isotope fractionation factors at low temperatures, primarily due to extrapolation from experimental calibrations at high temperature. We report the first measurements of silicon isotope ratios from experimentally precipitated quartz and estimate the equilibrium fractionation vs. dissolved silica using a novel in situ analysis technique applying secondary ion mass spectrometry to directly analyze experimental products. These experiments also yield a new value for oxygen isotope fractionation. Quartz overgrowths up tomore » 235 μm thick were precipitated in silica–H 2O–NaOH–NaCl fluids, at pH 12–13 and 250 °C. At this temperature, 1000lnα 30Si(Qtz–fluid) = 0.55 ± 0.10‰ and 1000lnα 18O(Qtz–fluid) = 10.62 ± 0.13‰, yielding the relations 1000lnα 30Si(Qtz–fluid) = (0.15 ± 0.03) * 10 6/T 2 and 1000lnα 18O(Qtz–fluid) = (2.91 ± 0.04) * 10 6/T 2 when extended to zero fractionation at infinite temperature. Values of δ 30Si(Qtz) from diagenetic cement in sandstones from the basal Cambrian Mt. Simon Formation in central North America range from 0 to ₋5.4‰. Paired δ 18O and δ 30Si values from individual overgrowths preserve a record of Precambrian weathering and fluid transport. In conclusion, the application of the experimental quartz growth results to observations from natural sandstone samples suggests that precipitation of quartz at low temperatures in nature is dominated by kinetic, rather than equilibrium, processes.« less

Globalization in Urology: A Bibliographical Analysis of Cross-Continent Publication between 2002 and 2012.

PubMed

Mani, Jens; Juengel, Eva; Bartsch, Georg; Filmann, Natalie; Ackermann, Hanns; Nelson, Karen; Haferkamp, Axel; Engl, Tobias; Blaheta, Roman A

2015-01-01

Asian scientists have now increasingly begun to contribute to globalization; yet it is not clear whether publishing in the field of urology is paralleled by elevated cross-continental scientific publishing. An exemplary bibliometric analysis of urologic journals from 3 different continents was conducted between 2002 and 2012. Based on the ISI Web of Knowledge Journal Citation Reports, 2 urologic journals with similar impact factors (IFs) in 2013 were selected from Europe ('British Journal of Urology International', 'World Journal of Urology'), Asia ('International Journal of Urology', 'Asian Journal of Andrology') and North America ('Urologic Oncology-Seminars and Original Investigations', 'Urology'). The home continent of the journal, the workplace continental affiliation of the last author, article type (clinical, experimental or review) as well as the IF were documented. Most authors published their manuscripts in journals from the same continent in which they worked. However, a significant increase in cross-continental publishing was apparent from 2002 to 2012. Asians publishing in North America increased from 17% in 2002 to 35% in 2012. Europeans also increased the number of articles they published in North American journals, while publications from North American authors were shifted towards both European and Asian journals. Experimental and clinical articles showed significant increases in cross-continental publishing, while review publishing showed no significant change. The average IF for authors from all 3 continents increased from 2002 to 2012 (p < 0.001). The largest increase in the IF was found for Asian authors (0.11 per year). Cross-continental publication significantly increased during the period from 2002 to 2012. The impact that the Asian authors have experienced was found to be gradually impacting the North American and European colleagues. © 2015 S. Karger AG, Basel.

Temperature And Wind Velocity Oscillations Along a Gentle Slope During Sea-Breeze Events

NASA Astrophysics Data System (ADS)

Bastin, Sophie; Drobinski, Philippe

2005-03-01

The flow structure on a gentle slope at Vallon d’Ol in the northern suburbs of Marseille in southern France has been documented by means of surface wind and temperature measurements collected from 7 June to 14 July 2001 during the ESCOMPTE experiment. The analysis of the time series reveals temperature and wind speed oscillations during several nights (about 60--90 min oscillation period) and several days (about 120-180 min oscillation period) during the whole observing period. Oscillating katabatic winds have been reported in the literature from theoretical, experimental and numerical studies. In the present study, the dynamics of the observed oscillating katabatic winds are in good agreement with the theory.In contrast to katabatic winds, no daytime observations of oscillating anabatic upslope flows have ever been published to our knowledge, probably because of temperature inversion break-up that inhibits upslope winds. The present paper shows that cold air advection by a sea breeze generates a mesoscale horizontal temperature gradient, and hence baroclinicity in the atmosphere, which then allows low-frequency oscillations, similar to a katabatic flow. An expression for the oscillation period is derived that accounts for the contribution of the sea-breeze induced mesoscale horizontal temperature gradient. The theoretical prediction of the oscillation period is compared to the measurements, and good agreement is found. The statistical analysis of the wind flow at Vallon d’Ol shows a dominant north-easterly to easterly flow pattern for nighttime oscillations and a dominant south-westerly flow pattern for daytime oscillations. These results are consistent with published numerical simulation results that show that the air drains off the mountain along the maximum slope direction, which in the studied case is oriented south-west to north-east.

Phase measurement error in summation of electron holography series.

PubMed

McLeod, Robert A; Bergen, Michael; Malac, Marek

2014-06-01

Off-axis electron holography is a method for the transmission electron microscope (TEM) that measures the electric and magnetic properties of a specimen. The electrostatic and magnetic potentials modulate the electron wavefront phase. The error in measurement of the phase therefore determines the smallest observable changes in electric and magnetic properties. Here we explore the summation of a hologram series to reduce the phase error and thereby improve the sensitivity of electron holography. Summation of hologram series requires independent registration and correction of image drift and phase wavefront drift, the consequences of which are discussed. Optimization of the electro-optical configuration of the TEM for the double biprism configuration is examined. An analytical model of image and phase drift, composed of a combination of linear drift and Brownian random-walk, is derived and experimentally verified. The accuracy of image registration via cross-correlation and phase registration is characterized by simulated hologram series. The model of series summation errors allows the optimization of phase error as a function of exposure time and fringe carrier frequency for a target spatial resolution. An experimental example of hologram series summation is provided on WS2 fullerenes. A metric is provided to measure the object phase error from experimental results and compared to analytical predictions. The ultimate experimental object root-mean-square phase error is 0.006 rad (2π/1050) at a spatial resolution less than 0.615 nm and a total exposure time of 900 s. The ultimate phase error in vacuum adjacent to the specimen is 0.0037 rad (2π/1700). The analytical prediction of phase error differs with the experimental metrics by +7% inside the object and -5% in the vacuum, indicating that the model can provide reliable quantitative predictions. Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.

Involvement of Indian hedgehog signaling in mesenchymal stem cell-augmented rotator cuff tendon repair in an athymic rat model.

PubMed

Zong, Jian-Chun; Mosca, Michael J; Degen, Ryan M; Lebaschi, Amir; Carballo, Camila; Carbone, Andrew; Cong, Guang-Ting; Ying, Liang; Deng, Xiang-Hua; Rodeo, Scott A

2017-04-01

Bone marrow aspirate has been used in recent years to augment tendon-to-bone healing, including in rotator cuff repair. However, the healing mechanism in cell-based therapy has not been elucidated in detail. Sixteen athymic nude rats were randomly allocated to 2 groups: experimental (human mesenchymal stem cells in fibrin glue carrier) and control (fibrin glue only). Animals were sacrificed at 2 and 4 weeks. Immunohistochemical staining was performed to evaluate Indian hedgehog (Ihh) signaling and SOX9 signaling in the healing enthesis. Macrophages were identified using CD68 and CD163 staining, and proliferating cells were identified using proliferating cell nuclear antigen staining. More organized and stronger staining for collagen II and a higher abundance of SOX9 + cells were observed at the enthesis in the experimental group at 2 weeks. There was significantly higher Gli1 and Patched1 expression in the experimental group at the enthesis at 2 weeks and higher numbers of Ihh + cells in the enthesis of the experimental group vs control at both 2 weeks and 4 weeks postoperatively. There were more CD68 + cells localized to the tendon midsubstance at 2 weeks compared with 4 weeks, and there was a higher level of CD163 staining in the tendon midsubstance in the experimental group than in the control group at 4 weeks. Stem cell application had a positive effect on fibrocartilage formation at the healing rotator cuff repair site. Both SOX9 and Ihh signaling appear to play an important role in the healing process. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Study Design Rigor in Animal-Experimental Research Published in Anesthesia Journals.

PubMed

Hoerauf, Janine M; Moss, Angela F; Fernandez-Bustamante, Ana; Bartels, Karsten

2018-01-01

Lack of reproducibility of preclinical studies has been identified as an impediment for translation of basic mechanistic research into effective clinical therapies. Indeed, the National Institutes of Health has revised its grant application process to require more rigorous study design, including sample size calculations, blinding procedures, and randomization steps. We hypothesized that the reporting of such metrics of study design rigor has increased over time for animal-experimental research published in anesthesia journals. PubMed was searched for animal-experimental studies published in 2005, 2010, and 2015 in primarily English-language anesthesia journals. A total of 1466 publications were graded on the performance of sample size estimation, randomization, and blinding. Cochran-Armitage test was used to assess linear trends over time for the primary outcome of whether or not a metric was reported. Interrater agreement for each of the 3 metrics (power, randomization, and blinding) was assessed using the weighted κ coefficient in a 10% random sample of articles rerated by a second investigator blinded to the ratings of the first investigator. A total of 1466 manuscripts were analyzed. Reporting for all 3 metrics of experimental design rigor increased over time (2005 to 2010 to 2015): for power analysis, from 5% (27/516), to 12% (59/485), to 17% (77/465); for randomization, from 41% (213/516), to 50% (243/485), to 54% (253/465); and for blinding, from 26% (135/516), to 38% (186/485), to 47% (217/465). The weighted κ coefficients and 98.3% confidence interval indicate almost perfect agreement between the 2 raters beyond that which occurs by chance alone (power, 0.93 [0.85, 1.0], randomization, 0.91 [0.85, 0.98], and blinding, 0.90 [0.84, 0.96]). Our hypothesis that reported metrics of rigor in animal-experimental studies in anesthesia journals have increased during the past decade was confirmed. More consistent reporting, or explicit justification for absence, of sample size calculations, blinding techniques, and randomization procedures could better enable readers to evaluate potential sources of bias in animal-experimental research manuscripts. Future studies should assess whether such steps lead to improved translation of animal-experimental anesthesia research into successful clinical trials.

TU-H-BRA-07: Design, Construction, and Installation of An Experimental Beam Line for the Development of MRI-Linac Compatible Electron Accelerator

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

Whelan, B; Keall, P; Holloway, L

Purpose: MRI guided radiation therapy (MRIgRT) is a rapidly growing field; however, Linac operation in MRI fringe fields represents an ongoing challenge. We have previously shown in-silico that Linacs could be redesigned to function in the in-line orientation with no magnetic shielding by adopting an RF-gun configuration. Other authors have also published insilico studies of Linac operation in magnetic fields; however to date no experimental validation data is published. This work details the design, construction, and installation of an experimental beam line to validate our in-silico results. Methods: An RF-gun comprising 1.5 accelerating cells and capable of generating electron energiesmore » up to 3.2MeV is used. The experimental apparatus was designed to monitor both beam current (toroid current monitor), spot size (two phosphor screens with viewports), and generate peak magnetic fields of at least 1000G (three variable current electromagnetic coils). Thermal FEM simulations were developed to ensure coil temperature remained within 100degC. Other design considerations included beam disposal, vacuum maintenance, radiation shielding, earthquake safety, and machine protection interlocks. Results: The beam line has been designed, built, and installed in a radiation shielded bunker. Water cooling, power supplies, thermo-couples, cameras, and radiation shielding have been successfully connected and tested. Interlock testing, vacuum processing, and RF processing have been successfully completed. The first beam on is expected within weeks. The coil heating simulations show that with care, peak fields of up to 1200G (320G at cathode) can be produced using 40A current, which is well within the fields expected for MRI-Linac systems. The maximum coil temperature at this current was 84degC after 6 minutes. Conclusion: An experimental beam line has been constructed and installed at SLAC in order to experimentally characterise RF gun performance in in-line magnetic fields, validate in-silico design work, and provide the first published experimental data relating to accelerator functionality for MRIgRT.« less

The Fraser Experimental Forest, Colorado: Research program and published research 1937-1985

Treesearch

Robert R. Alexander; Charles A. Troendle; Merrill R. Kaufmann; Wayne D. Shepperd; Glenn L. Crouch; Ross K. Watkins

1985-01-01

This report provides an overview of the research done on the Fraser Experimental Forest. It replaces GTR's no. 40 and 40A by Robert R. Alexander and Ross K. Watkins in 1977. Included are descriptions of physical features and resources, highlights of past and current research, and the publications derived from that research.

A Review of Teaching Sentence-Level Writing Skills to Students with Writing Difficulties and Learning Disabilities

ERIC Educational Resources Information Center

Datchuk, Shawn M.; Kubina, Richard M.

2013-01-01

Students with writing difficulties and learning disabilities struggle with many aspects of the writing process, including use of sentence-level skills. This literature review summarizes results from 19 published articles that used single-case or group-experimental and quasi-experimental designs to investigate effects of intervention on the…

Discussing the Need of Experimental Replication with 5th Grade Students Conducting a Mealworm Experiment

ERIC Educational Resources Information Center

Asshoff, Roman

2017-01-01

Scientific inquiry requires the replication of results in experimental studies. Recent studies draw a severe picture on the need of replication and the difficulties in replicating already published studies. As replicated confirmation of results is the basis of scientific and medical research, there may be a need to introduce the topic of…

78 FR 5162 - Designation of a Nonessential Experimental Population of Central Valley Spring-Run Chinook Salmon...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-24

... Director, Office of Protected Resources, National Marine Fisheries Service. [FR Doc. 2013-01343 Filed 1-23.... SUMMARY: On January 16, 2013, we, NMFS, published a proposed rule to designate a nonessential experimental... January 29, 2013, at the Fresno Metropolitan Flood Control District, Board Meeting Room, 5469 E. Olive...

Animal-Assisted Therapies for Youth with or at Risk for Mental Health Problems: A Systematic Review

ERIC Educational Resources Information Center

Hoagwood, Kimberly Eaton; Acri, Mary; Morrissey, Meghan; Peth-Pierce, Robin

2017-01-01

To systematically review experimental evidence regarding animal-assisted therapies (AAT) for children or adolescents with or at risk for mental health conditions, we reviewed all experimental AAT studies published between 2000-2015, and compared studies by animal type, intervention, and outcomes. Studies were included if used therapeutically for…

Vertebrate fauna of the San Joaquin Experimental Range, California: a checklist

Treesearch

Thomas F. Newman; Don A. Duncan

1973-01-01

This report updates an earlier checklist, published in 1955, of vertebrate fauna found on the San Joaquin Experimental Range, in Madera County, California. Nineteen new species have been recorded since 1955. This report records the occurrences of seven fish, eight amphibians, 19 reptiles, 38 mammals, and 149 buds. References to research on individual species are...

Trends in animal experimentation.

PubMed

Monteiro, Rosangela; Brandau, Ricardo; Gomes, Walter J; Braile, Domingo M

2009-01-01

The search of the understanding of etiological factors, mechanisms and treatment of the diseases has been taking to the development of several animal models in the last decades. To discuss aspects related to animal models of experimentation, animal choice and current trends in this field in our country. In addition, this study evaluated the frequency of experimental articles in medical journals. Five Brazilian journals indexed by LILACS, SciELO, MEDLINE, and recently incorporate for Institute for Scientific Information Journal of Citation Reports were analyzed. All the papers published in those journals, between 2007 and 2008, that used animal models, were selected based on the abstracts. Of the total of 832 articles published in the period, 92 (11.1%) experimentation papers were selected. The number of experimental articles ranged from 5.2% to 17.9% of the global content of the journal. In the instructions to the authors, four (80%) journals presented explicit reference to the ethical principles in the conduction of studies with animals. The induced animal models represented 100% of the articles analyzed in this study. The rat was the most employed animal in the analyzed articles (78.3%). The present study can contribute, supplying subsidies for adoption of future editorials policies regarding the publication of animal research papers in Brazilian Journal of Cardiovascular Surgery.

Robust Hinfinity position control synthesis of an electro-hydraulic servo system.

PubMed

Milić, Vladimir; Situm, Zeljko; Essert, Mario

2010-10-01

This paper focuses on the use of the techniques based on linear matrix inequalities for robust H(infinity) position control synthesis of an electro-hydraulic servo system. A nonlinear dynamic model of the hydraulic cylindrical actuator with a proportional valve has been developed. For the purpose of the feedback control an uncertain linearized mathematical model of the system has been derived. The structured (parametric) perturbations in the electro-hydraulic coefficients are taken into account. H(infinity) controller extended with an integral action is proposed. To estimate internal states of the electro-hydraulic servo system an observer is designed. Developed control algorithms have been tested experimentally in the laboratory model of an electro-hydraulic servo system. Copyright © 2010 ISA. Published by Elsevier Ltd. All rights reserved.

The prediction of the cavitation phenomena including population balance modeling

NASA Astrophysics Data System (ADS)

Bannari, Rachid; Hliwa, Ghizlane Zineb; Bannari, Abdelfettah; Belghiti, Mly Taib

2017-07-01

Cavitation is the principal reason behind the behavior's modification of the hydraulic turbines. However, the experimental observations can not be appropriate to all cases due to the limitations in the measurement techniques. The mathematical models which have been implemented, use the mixture multiphase frame. As well as, most of the published work is limited by considering a constant bubble size distribution. However, this assumption is not realist. The aim of this article is the implementation and the use of a non-homogeneous multiphase model which solve two phases transport equation. The evolution of bubble size is considered by the population balance equation. This study is based on the eulerian-eulerian model, associated to the cavitation model. All the inter-phase forces such as drag, lift and virtual mass are used.

Determination of the global recombination rate coefficient for the ISX-B Tokamak

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

Langley, R.A.; Howe, H.C.

1983-01-01

The global recombination rate coefficient for hydrogen has been measured for the ISX-B tokamak vacuum vessel for various surface conditions. The measurements were performed by observing the rate of decrease of gas pressure in the vessel during a glow discharge. The parameters of the glow discharge and the complete experimental method are described. Previously published analytic and numerical models are used for data analysis. The effects of surface contamination on the results are described. For ''unclean'' wall conditions sigmak/sub r/ = 1.8 x 10/sup -28/ cm/sup 4//atom.s at 296 K and increases to sigmak/sub r/ = 4.4 x 10/sup -28/more » cm/sup 4//atoms.s for ''clean'' conditions and remains constant until subsequent exposure to air.« less

Metabolic heterogeneity in clonal microbial populations.

PubMed

Takhaveev, Vakil; Heinemann, Matthias

2018-02-21

In the past decades, numerous instances of phenotypic diversity were observed in clonal microbial populations, particularly, on the gene expression level. Much less is, however, known about phenotypic differences that occur on the level of metabolism. This is likely explained by the fact that experimental tools probing metabolism of single cells are still at an early stage of development. Here, we review recent exciting discoveries that point out different causes for metabolic heterogeneity within clonal microbial populations. These causes range from ecological factors and cell-inherent dynamics in constant environments to molecular noise in gene expression that propagates into metabolism. Furthermore, we provide an overview of current methods to quantify the levels of metabolites and biomass components in single cells. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Variability in seeds: biological, ecological, and agricultural implications.

PubMed

Mitchell, Jack; Johnston, Iain G; Bassel, George W

2017-02-01

Variability is observed in biology across multiple scales, ranging from populations, individuals, and cells to the molecular components within cells. This review explores the sources and roles of this variability across these scales, focusing on seeds. From a biological perspective, the role and the impact this variability has on seed behaviour and adaptation to the environment is discussed. The consequences of seed variability on agricultural production systems, which demand uniformity, are also examined. We suggest that by understanding the basis and underlying mechanisms of variability in seeds, strategies to increase seed population uniformity can be developed, leading to enhanced agricultural production across variable climatic conditions. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Comparison of G protein sequences of South African street rabies viruses showing distinct progression of the disease in a mouse model of experimental rabies.

PubMed

Seo, Wonhyo; Servat, Alexandre; Cliquet, Florence; Akinbowale, Jenkins; Prehaud, Christophe; Lafon, Monique; Sabeta, Claude

Rabies is a fatal zoonotic disease and infections generally lead to a fatal encephalomyelitis in both humans and animals. In South Africa, domestic (dogs) and the wildlife (yellow mongoose) host species maintain the canid and mongoose rabies variants respectively. In this study, pathogenicity differences of South African canid and mongoose rabies viruses were investigated in a murine model, by assessing the progression of clinical signs and survivorship. Comparison of glycoprotein gene sequences revealed amino acid differences that may underpin the observed pathogenicity differences. Cumulatively, our results suggest that the canid rabies virus may be more neurovirulent in mice than the mongoose rabies variant. Copyright © 2017 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Saffman-Taylor Instability and the Inner Splitting Mechanism

NASA Astrophysics Data System (ADS)

Oliveira, Rafael; Meiburg, Eckart

2017-11-01

The classical miscible displacement experiments of Wooding (1969) exhibit an inner splitting phenomenon that remained unexplained for over 40 years. 3D Navier-Stokes simulations presented in, were the first ones to reproduce these experimental observations numerically, and to demonstrate that they are linked to concentrated streamwise vortices. The origin of these concentrated streamwise vortices remained a mystery, however. The current investigation, published at, finally resolves this long-standing issue. Towards this end, we compare 3D Navier-Stokes simulation results for neutrally buoyant, viscously unstable displacements and gravitationally unstable, constant viscosity ones. Only the former exhibit the generation of streamwise vorticity. The simulation results present conclusive evidence that it is caused by the lateral displacement of the more viscous fluid by the less viscous one, with the variable viscosity terms playing a dominant role.

The AMP-activated protein kinase beta 1 subunit modulates erythrocyte integrity.

PubMed

Cambridge, Emma L; McIntyre, Zoe; Clare, Simon; Arends, Mark J; Goulding, David; Isherwood, Christopher; Caetano, Susana S; Reviriego, Carmen Ballesteros; Swiatkowska, Agnieszka; Kane, Leanne; Harcourt, Katherine; Adams, David J; White, Jacqueline K; Speak, Anneliese O

2017-01-01

Failure to maintain a normal in vivo erythrocyte half-life results in the development of hemolytic anemia. Half-life is affected by numerous factors, including energy balance, electrolyte gradients, reactive oxygen species, and membrane plasticity. The heterotrimeric AMP-activated protein kinase (AMPK) is an evolutionarily conserved serine/threonine kinase that acts as a critical regulator of cellular energy balance. Previous roles for the alpha 1 and gamma 1 subunits in the control of erythrocyte survival have been reported. In the work described here, we studied the role of the beta 1 subunit in erythrocytes and observed microcytic anemia with compensatory extramedullary hematopoiesis together with splenomegaly and increased osmotic resistance. Copyright © 2016 ISEH - International Society for Experimental Hematology. Published by Elsevier Inc. All rights reserved.

State of the Science-Ultraendurance Sports.

PubMed

Hoffman, Martin D

2016-09-01

Participation in ultraendurance sports has been increasing in recent years. This participation growth has been associated with an increase in research focused on such events. While the total amount of research related to these sports remains relatively small compared with other sports, the research growth is encouraging. New sources for research funding for ultraendurance sports should advance the science. In addition to continued opportunities with observational studies, promising areas of investigation remain for experimental studies and research that uses ultraendurance-sport environments as models for studies relevant to wider populations. Insight into the breadth of research opportunities in ultraendurance sports can be gained by reviewing the abstracts published online in the International Journal of Sports Physiology and Performance from the annual Medicine & Science in Ultra-Endurance Sports Conference that took place this year in Chamonix, France.

Witnessing entanglement without entanglement witness operators.

PubMed

Pezzè, Luca; Li, Yan; Li, Weidong; Smerzi, Augusto

2016-10-11

Quantum mechanics predicts the existence of correlations between composite systems that, although puzzling to our physical intuition, enable technologies not accessible in a classical world. Notwithstanding, there is still no efficient general method to theoretically quantify and experimentally detect entanglement of many qubits. Here we propose to detect entanglement by measuring the statistical response of a quantum system to an arbitrary nonlocal parametric evolution. We witness entanglement without relying on the tomographic reconstruction of the quantum state, or the realization of witness operators. The protocol requires two collective settings for any number of parties and is robust against noise and decoherence occurring after the implementation of the parametric transformation. To illustrate its user friendliness we demonstrate multipartite entanglement in different experiments with ions and photons by analyzing published data on fidelity visibilities and variances of collective observables.

Research in Theoretical Particle Physics

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

Ralston, John P.

This document is the final report on activity of the University of Kansas theory group supported under DOE Grant Number DE-FG02-04ER14308, ending April 30, 3013. The report covers the most recent three year period period May 1, 2010-April 30, 2013. Faculty supported by the grant during the period were Danny Marfatia (co-I), Douglas McKay (emeritus) and John Ralston (PI). The group's research topics and accomplishments covered numerous different topics subsumed under the {\\it the Energy Frontier, the Intensity Frontier}, and {\\it the Cosmic Frontier}. Many theoretical and experimental results related to the Standard Model and models of new physics weremore » published during the reporting period. The group's research emphasis has been on challenging and confronting {\\it Anything that is Observable} about the physical Universe.« less

Lysine-based surfactants as chemical permeation enhancers for dermal delivery of local anesthetics.

PubMed

Teixeira, Raquel S; Cova, Tânia F G G; Silva, Sérgio M C; Oliveira, Rita; Araújo, Maria J; Marques, Eduardo F; Pais, Alberto A C C; Veiga, Francisco J B

2014-10-20

The aim of this study is to investigate the efficacy of new, biocompatible, lysine-based surfactants as chemical permeation enhancers for two different local anesthetics, tetracaine and ropivacaine hydrochloride, topically administered. Results show that this class of surfactants strongly influences permeation, especially in the case of the hydrophilic and ionized drug, ropivacaine hydrochloride, that is not easily administered through the stratum corneum. It is also seen that the selected permeation enhancers do not have significant deleterious effects on the skin structure. A cytotoxicity profile for each compound was established from cytotoxicity studies. Molecular dynamics simulation results provided a rationale for the experimental observations, introducing a mechanistic view of the action of the surfactants molecules upon lipid membranes. Copyright © 2014. Published by Elsevier B.V.

CALL FOR PAPERS: Special cluster issue on `Experimental studies of zonal flow and turbulence'

NASA Astrophysics Data System (ADS)

Itoh, S.-I.

2005-07-01

Plasma Physics and Controlled Fusion (PPCF) invites submissions on the topic of `Experimental studies of zonal flow and turbulence', for consideration for a special topical cluster of articles to be published early in 2006. The topical cluster will be published in an issue of PPCF, combined with regular articles. The Guest Editor for the special cluster will be S-I Itoh, Kyushu University, Japan. There has been remarkable progress in the area of structure formation by turbulence. One of the highlights has been the physics of zonal flow and drift wave turbulence in toroidal plasmas. Extensive theoretical as well as computational studies have revealed the various mechanisms in turbulence and zonal flows. At the same time, experimental research on the zonal flow, geodesic acoustic modes and generation of global electric field by turbulence has evolved rapidly. Fast growth in reports of experimental results has stimulated further efforts to develop increased knowledge and systematic understanding. Each paper considered for the special cluster should describe the present research status and new scientific knowledge/results from the authors on experimental studies of zonal flow, geodesic acoustic modes and generation of electric field by turbulence (including studies of Reynolds-Maxwell stresses, etc). Manuscripts submitted to this special cluster in Plasma Physics and Controlled Fusion will be refereed according to the normal criteria and procedures of the journal. The Guest Editor guides the progress of the cluster from the initial open call, through the standard refereeing process, to publication. To be considered for inclusion in the special cluster, articles must be submitted by 2 September 2005 and must clearly state `for inclusion in the Turbulent Plasma Cluster'. Articles submitted after this deadline may not be included in the cluster issue but may be published in a later issue of the journal. Please submit your manuscript electronically via our web site at www.iop.org/journals/ppcf or by e-mail to mailto:ppcf@iop.org. Electronic submissions are encouraged but if you wish to submit a hard copy of your article then please send your typescript, a set of original figures and a covering letter to: The Publishing Administrator Plasma Physics and Controlled Fusion Institute of Physics Publishing Dirac House Temple Back Bristol BS1 6BE UK Further information on how to submit may be obtained on request by e-mailing the journal at the above address. Alternatively, visit the homepage of the journal (www.iop.org/journals/ppcf).

Generalized predictive control for a coupled four tank MIMO system using a continuous-discrete time observer.

PubMed

Gouta, Houssemeddine; Hadj Saïd, Salim; Barhoumi, Nabil; M'Sahli, Faouzi

2017-03-01

This paper deals with the problem of the observer based control design for a coupled four-tank liquid level system. For this MIMO system's dynamics, motivated by a desire to provide precise and sensorless liquid level control, a nonlinear predictive controller based on a continuous-discrete observer is presented. First, an analytical solution from the model predictive control (MPC) technique is developed for a particular class of nonlinear MIMO systems and its corresponding exponential stability is proven. Then, a high gain observer that runs in continuous-time with an output error correction time that is updated in a mixed continuous-discrete fashion is designed in order to estimate the liquid levels in the two upper tanks. The effectiveness of the designed control schemes are validated by two tests; The first one is maintaining a constant level in the first bottom tank while making the level in the second bottom tank to follow a sinusoidal reference signal. The second test is more difficult and it is made using two trapezoidal reference signals in order to see the decoupling performance of the system's outputs. Simulation and experimental results validate the objective of the paper. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

Cell Division Induces and Switches Coherent Angular Motion within Bounded Cellular Collectives.

PubMed

Siedlik, Michael J; Manivannan, Sriram; Kevrekidis, Ioannis G; Nelson, Celeste M

2017-06-06

Collective cell migration underlies many biological processes, including embryonic development, wound healing, and cancer progression. In the embryo, cells have been observed to move collectively in vortices using a mode of collective migration known as coherent angular motion (CAM). To determine how CAM arises within a population and changes over time, here, we study the motion of mammary epithelial cells within engineered monolayers, in which the cells move collectively about a central axis in the tissue. Using quantitative image analysis, we find that CAM is significantly reduced when mitosis is suppressed. Particle-based simulations recreate the observed trends, suggesting that cell divisions drive the robust emergence of CAM and facilitate switches in the direction of collective rotation. Our simulations predict that the location of a dividing cell, rather than the orientation of the division axis, facilitates the onset of this motion. These predictions agree with experimental observations, thereby providing, to our knowledge, new insight into how cell divisions influence CAM within a tissue. Overall, these findings highlight the dynamic nature of CAM and suggest that regulating cell division is crucial for tuning emergent collective migratory behaviors, such as vortical motions observed in vivo. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

The Current Experimental Status of the High Tc Problem

NASA Astrophysics Data System (ADS)

Greene, Richard

Over 50,000 experimental papers have been published since 1987 on the copper oxide (cuprate) high Tc superconductors. In this talk, I will attempt to summarize the experimental properties that we presently understand and those that we don't yet understand. I will not speculate on the ``unknown unknowns'', although some examples of these have appeared during the past 30 years of research. I may also present a few slides about the status of iron-based superconductors, the other major class of unconventional high Tc materials.

[Efficacy of the application of kinesio tape in patients with stroke].

PubMed

Ortiz-Ramirez, J; Perez-De la Cruz, S

2017-02-16

To review the effects achieved by the kinesio tape in patients with stroke in scientific studies published on date and to discuss these findings may be of interest to neurology. An exhaustive search in the main scientific databases using keywords such as kinesio tape, kinesiotaping, musculoskeletal tape, taping medical concept was carried out. Citations of selected articles and scientific papers published on the website of the Spanish Association of Neuromuscular Bandage were analyzed. Experimental, quasi-experimental, clinical trials and case studies published were used, without limit date, with therapeutical treatment purpose provide important results. Eight articles have met the inclusion criteria. There are eight studies that examine the effect on kinesio tape on lower limb, gait and balance in this kind of therapy, even upper limb and swallowing problems that these patients could present. The kinesio tape in neurological patients can be a complementary technique that empirically provides benefits. However, better methodological quality studies demonstrating the effects attributed to him are still needed.

Modification of codes NUALGAM and BREMRAD, Volume 1

NASA Technical Reports Server (NTRS)

Steyn, J. J.; Huang, R.; Firstenberg, H.

1971-01-01

The NUGAM2 code predicts forward and backward angular energy differential and integrated distributions for gamma photons and fluorescent radiation emerging from finite laminar transport media. It determines buildup and albedo data for scientific research and engineering purposes; it also predicts the emission characteristics of finite radioisotope sources. The results are shown to be in very good agreement with available published data. The code predicts data for many situations in which no published data is available in the energy range up to 5 MeV. The NUGAM3 code predicts the pulse height response of inorganic (NaI and CsI) scintillation detectors to gamma photons. Because it allows the scintillator to be clad and mounted on a photomultiplier as in the experimental or industrial application, it is a more practical and thus useful code than others previously reported. Results are in excellent agreement with published Monte Carlo and experimental data in the energy range up to 4.5 MeV.

First observations of the midlatitude evening anomaly using Super Dual Auroral Radar Network (SuperDARN) radars

NASA Astrophysics Data System (ADS)

de Larquier, S.; Ruohoniemi, J. M.; Baker, J. B. H.; Ravindran Varrier, N.; Lester, M.

2011-10-01

Under geomagnetically quiet conditions, the daytime midlatitude ionosphere is mainly influenced by solar radiation: typically, electron densities in the ionosphere peak around solar noon. Previous observations from the Millstone Hill incoherent scatter radar (ISR) have evidenced the presence of evening electron densities higher than daytime densities during the summer. The recent development of midlatitude Super Dual Auroral Radar Network (SuperDARN) radars over North America and Japan has revealed an evening enhancement in ground backscatter during the summer. SuperDARN observations are compared to data from the Millstone Hill ISR, confirming a direct relation between the observed evening enhancements in electron densities and ground backscatter. Statistics over a year of data from the Blackstone radar show that the enhancement occurs during sunset for a few hours from April to September. The evening enhancement observed by both SuperDARN and the Millstone Hill ISR is shown to be related to recent satellite observations reporting an enhancement in electron densities over a wide range of longitudes in the Northern Hemisphere midlatitude sector during summer time. Finally, global results from the International Reference Ionosphere (IRI) and the horizontal wind model (HWM07) are presented in relation with previously published experimental results and proposed mechanisms of the evening enhancement, namely, thermospheric horizontal winds and geomagnetic field configuration. It is shown that the IRI captures the features of the evening enhancement as observed by SuperDARN radars and satellites.

Entropy vs. energy waveform processing: A comparison based on the heat equation

DOE PAGES

Hughes, Michael S.; McCarthy, John E.; Bruillard, Paul J.; ...

2015-05-25

Virtually all modern imaging devices collect electromagnetic or acoustic waves and use the energy carried by these waves to determine pixel values to create what is basically an “energy” picture. However, waves also carry “information”, as quantified by some form of entropy, and this may also be used to produce an “information” image. Numerous published studies have demonstrated the advantages of entropy, or “information imaging”, over conventional methods. The most sensitive information measure appears to be the joint entropy of the collected wave and a reference signal. The sensitivity of repeated experimental observations of a slowly-changing quantity may be definedmore » as the mean variation (i.e., observed change) divided by mean variance (i.e., noise). Wiener integration permits computation of the required mean values and variances as solutions to the heat equation, permitting estimation of their relative magnitudes. There always exists a reference, such that joint entropy has larger variation and smaller variance than the corresponding quantities for signal energy, matching observations of several studies. Moreover, a general prescription for finding an “optimal” reference for the joint entropy emerges, which also has been validated in several studies.« less

The Doctrine of Original Antigenic Sin: Separating Good From Evil.

PubMed

Monto, Arnold S; Malosh, Ryan E; Petrie, Joshua G; Martin, Emily T

2017-06-15

The term "original antigenic sin" was coined approximately 60 years ago to describe the imprinting by the initial first influenza A virus infection on the antibody response to subsequent vaccination. These studies did not suggest a reduction in the response to current antigens but instead suggested anamnestic recall of antibody to earlier influenza virus strains. Then, approximately 40 years ago, it was observed that sequential influenza vaccination might lead to reduced vaccine effectiveness (VE). This conclusion was largely dismissed after an experimental study involving sequential administration of then-standard influenza vaccines. Recent observations have provided convincing evidence that reduced VE after sequential influenza vaccination is a real phenomenon. We propose that such reduction in VE be termed "negative antigenic interaction," given that there is no age cohort effect. In contrast, the potentially positive protective effect of early influenza virus infection later in life continues to be observed. It is essential that we understand better the immunologic factors underlying both original antigenic sin and negative antigenic interaction, to support development of improved influenza vaccines and vaccination strategies. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America.

Simulation of local ion transport in lamellar block copolymer electrolytes based on electron micrographs

DOE PAGES

Chintapalli, Mahati; Higa, Kenneth; Chen, X. Chelsea; ...

2016-12-19

A method is presented in this paper to relate local morphology and ionic conductivity in a solid, lamellar block copolymer electrolyte for lithium batteries, by simulating conductivity through transmission electron micrographs. The electrolyte consists of polystyrene-block-poly(ethylene oxide) mixed with lithium bis(trifluoromethanesulfonyl) imide salt (SEO/LiTFSI), where the polystyrene phase is structural phase and the poly(ethylene oxide)/LiTFSI phase is ionically conductive. The electric potential distribution is simulated in binarized micrographs by solving the Laplace equation with constant potential boundary conditions. A morphology factor, f, is reported for each image by calculating the effective conductivity relative to a homogenous conductor. Images from twomore » samples are examined, one annealed with large lamellar grains and one unannealed with small grains. The average value off is 0.45 ± 0.04 for the annealed sample, and 0.37 ± 0.03 for the unannealed sample, both close to the value predicted by effective medium theory, 1/2. Simulated conductivities are compared to published experimental conductivities. The value of f Unannealed/f Annealed is 0.82 for simulations and 6.2 for experiments. Simulation results correspond well to predictions by effective medium theory but do not explain the experimental measurements. Finally, observation of nanoscale morphology over length scales greater than the size of the micrographs (~1 μm) may be required to explain the experimental results.« less

Model anodes and anode models for understanding the mechanism of hydrogen oxidation in solid oxide fuel cells.

PubMed

Bessler, Wolfgang G; Vogler, Marcel; Störmer, Heike; Gerthsen, Dagmar; Utz, Annika; Weber, André; Ivers-Tiffée, Ellen

2010-11-14

This article presents a literature review and new results on experimental and theoretical investigations of the electrochemistry of solid oxide fuel cell (SOFC) model anodes, focusing on the nickel/yttria-stabilized zirconia (Ni/YSZ) materials system with operation under H(2)/H(2)O atmospheres. Micropatterned model anodes were used for electrochemical characterization under well-defined operating conditions. Structural and chemical integrity was confirmed by ex situ pre-test and post-test microstructural and chemical analysis. Elementary kinetic models of reaction and transport processes were used to assess reaction pathways and rate-determining steps. The comparison of experimental and simulated electrochemical behaviors of pattern anodes shows quantitative agreement over a wide range of operating conditions (p(H(2)) = 8×10(2) - 9×10(4) Pa, p(H(2)O) = 2×10(1) - 6×10(4) Pa, T = 400-800 °C). Previously published experimental data on model anodes show a strong scatter in electrochemical performance. Furthermore, model anodes exhibit a pronounced dynamics on multiple time scales which is not reproduced in state-of-the-art models and which is also not observed in technical cermet anodes. Potential origin of these effects as well as consequences for further steps in model anode and anode model studies are discussed.

The Use of Virtual Reality in the Study of People's Responses to Violent Incidents.

PubMed

Rovira, Aitor; Swapp, David; Spanlang, Bernhard; Slater, Mel

2009-01-01

This paper reviews experimental methods for the study of the responses of people to violence in digital media, and in particular considers the issues of internal validity and ecological validity or generalisability of results to events in the real world. Experimental methods typically involve a significant level of abstraction from reality, with participants required to carry out tasks that are far removed from violence in real life, and hence their ecological validity is questionable. On the other hand studies based on field data, while having ecological validity, cannot control multiple confounding variables that may have an impact on observed results, so that their internal validity is questionable. It is argued that immersive virtual reality may provide a unification of these two approaches. Since people tend to respond realistically to situations and events that occur in virtual reality, and since virtual reality simulations can be completely controlled for experimental purposes, studies of responses to violence within virtual reality are likely to have both ecological and internal validity. This depends on a property that we call 'plausibility' - including the fidelity of the depicted situation with prior knowledge and expectations. We illustrate this with data from a previously published experiment, a virtual reprise of Stanley Milgram's 1960s obedience experiment, and also with pilot data from a new study being developed that looks at bystander responses to violent incidents.

Synthesis, characterization and vibrational spectra analysis of ethyl (2Z)-2-(2-amino-4-oxo-1,3-oxazol-5(4H)-ylidene)-3-oxo-3-phenylpropanoate.

PubMed

Kıbrız, Ibrahim Evren; Sert, Yusuf; Saçmacı, Mustafa; Sahin, Ertan; Yıldırım, Ismail; Ucun, Fatih

2013-10-01

In the present study, the experimental and theoretical vibrational spectra of ethyl (2Z)-2-(2-amino-4-oxo-1,3-oxazol-5(4H)-ylidene)-3-oxo-3-phenylpropanoate (AOX) were investigated. The experimental FT-IR (400-4000 cm(-1)) and Laser-Raman spectra (100-4000 cm(-1)) of the molecule in the solid phase were recorded. Theoretical vibrational frequencies and geometric parameters (bond lengths, bond angles and torsion angles) were calculated using ab initio Hartree Fock (HF), Density Functional Theory (B3LYP and B3PW91) methods with 6-311++G(d,p) basis set by Gaussian 03 program, for the first time. The computed values of frequencies are scaled using a suitable scale factor to yield good coherence with the observed values. The assignments of the vibrational frequencies were performed by potential energy distribution (PED) analysis by using VEDA 4 program. The theoretical optimized geometric parameters and vibrational frequencies were compared with the corresponding experimental X-ray diffraction data, and they were seen to be in a good agreement with each other. The hydrogen bonding geometry of the molecule was also simulated to evaluate the effect of intermolecular hydrogen bonding on the vibrational frequencies. Also, the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energies were found. Published by Elsevier B.V.

The Use of Virtual Reality in the Study of People's Responses to Violent Incidents

PubMed Central

Rovira, Aitor; Swapp, David; Spanlang, Bernhard; Slater, Mel

2009-01-01

This paper reviews experimental methods for the study of the responses of people to violence in digital media, and in particular considers the issues of internal validity and ecological validity or generalisability of results to events in the real world. Experimental methods typically involve a significant level of abstraction from reality, with participants required to carry out tasks that are far removed from violence in real life, and hence their ecological validity is questionable. On the other hand studies based on field data, while having ecological validity, cannot control multiple confounding variables that may have an impact on observed results, so that their internal validity is questionable. It is argued that immersive virtual reality may provide a unification of these two approaches. Since people tend to respond realistically to situations and events that occur in virtual reality, and since virtual reality simulations can be completely controlled for experimental purposes, studies of responses to violence within virtual reality are likely to have both ecological and internal validity. This depends on a property that we call ‘plausibility’ – including the fidelity of the depicted situation with prior knowledge and expectations. We illustrate this with data from a previously published experiment, a virtual reprise of Stanley Milgram's 1960s obedience experiment, and also with pilot data from a new study being developed that looks at bystander responses to violent incidents. PMID:20076762

Simulation of local ion transport in lamellar block copolymer electrolytes based on electron micrographs

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

Chintapalli, Mahati; Higa, Kenneth; Chen, X. Chelsea

A method is presented in this paper to relate local morphology and ionic conductivity in a solid, lamellar block copolymer electrolyte for lithium batteries, by simulating conductivity through transmission electron micrographs. The electrolyte consists of polystyrene-block-poly(ethylene oxide) mixed with lithium bis(trifluoromethanesulfonyl) imide salt (SEO/LiTFSI), where the polystyrene phase is structural phase and the poly(ethylene oxide)/LiTFSI phase is ionically conductive. The electric potential distribution is simulated in binarized micrographs by solving the Laplace equation with constant potential boundary conditions. A morphology factor, f, is reported for each image by calculating the effective conductivity relative to a homogenous conductor. Images from twomore » samples are examined, one annealed with large lamellar grains and one unannealed with small grains. The average value off is 0.45 ± 0.04 for the annealed sample, and 0.37 ± 0.03 for the unannealed sample, both close to the value predicted by effective medium theory, 1/2. Simulated conductivities are compared to published experimental conductivities. The value of f Unannealed/f Annealed is 0.82 for simulations and 6.2 for experiments. Simulation results correspond well to predictions by effective medium theory but do not explain the experimental measurements. Finally, observation of nanoscale morphology over length scales greater than the size of the micrographs (~1 μm) may be required to explain the experimental results.« less

Visualization of spiral and scroll waves in simulated and experimental cardiac tissue

NASA Astrophysics Data System (ADS)

Cherry, E. M.; Fenton, F. H.

2008-12-01

The heart is a nonlinear biological system that can exhibit complex electrical dynamics, complete with period-doubling bifurcations and spiral and scroll waves that can lead to fibrillatory states that compromise the heart's ability to contract and pump blood efficiently. Despite the importance of understanding the range of cardiac dynamics, studying how spiral and scroll waves can initiate, evolve, and be terminated is challenging because of the complicated electrophysiology and anatomy of the heart. Nevertheless, over the last two decades advances in experimental techniques have improved access to experimental data and have made it possible to visualize the electrical state of the heart in more detail than ever before. During the same time, progress in mathematical modeling and computational techniques has facilitated using simulations as a tool for investigating cardiac dynamics. In this paper, we present data from experimental and simulated cardiac tissue and discuss visualization techniques that facilitate understanding of the behavior of electrical spiral and scroll waves in the context of the heart. The paper contains many interactive media, including movies and interactive two- and three-dimensional Java appletsDisclaimer: IOP Publishing was not involved in the programming of this software and does not accept any responsibility for it. You download and run the software at your own risk. If you experience any problems with the software, please contact the author directly. To the fullest extent permitted by law, IOP Publishing Ltd accepts no responsibility for any loss, damage and/or other adverse effect on your computer system caused by your downloading and running this software. IOP Publishing Ltd accepts no responsibility for consequential loss..

Trace element partitioning between plagioclase and melt: An investigation of the impact of experimental and analytical procedures

NASA Astrophysics Data System (ADS)

Nielsen, Roger L.; Ustunisik, Gokce; Weinsteiger, Allison B.; Tepley, Frank J.; Johnston, A. Dana; Kent, Adam J. R.

2017-09-01

Quantitative models of petrologic processes require accurate partition coefficients. Our ability to obtain accurate partition coefficients is constrained by their dependence on pressure temperature and composition, and on the experimental and analytical techniques we apply. The source and magnitude of error in experimental studies of trace element partitioning may go unrecognized if one examines only the processed published data. The most important sources of error are relict crystals, and analyses of more than one phase in the analytical volume. Because we have typically published averaged data, identification of compromised data is difficult if not impossible. We addressed this problem by examining unprocessed data from plagioclase/melt partitioning experiments, by comparing models based on that data with existing partitioning models, and evaluated the degree to which the partitioning models are dependent on the calibration data. We found that partitioning models are dependent on the calibration data in ways that result in erroneous model values, and that the error will be systematic and dependent on the value of the partition coefficient. In effect, use of different calibration datasets will result in partitioning models whose results are systematically biased, and that one can arrive at different and conflicting conclusions depending on how a model is calibrated, defeating the purpose of applying the models. Ultimately this is an experimental data problem, which can be solved if we publish individual analyses (not averages) or use a projection method wherein we use an independent compositional constraint to identify and estimate the uncontaminated composition of each phase.

Auditory observation of stepping actions can cue both spatial and temporal components of gait in Parkinson׳s disease patients.

PubMed

Young, William R; Rodger, Matthew W M; Craig, Cathy M

2014-05-01

A common behavioural symptom of Parkinson׳s disease (PD) is reduced step length (SL). Whilst sensory cueing strategies can be effective in increasing SL and reducing gait variability, current cueing strategies conveying spatial or temporal information are generally confined to the use of either visual or auditory cue modalities, respectively. We describe a novel cueing strategy using ecologically-valid 'action-related' sounds (footsteps on gravel) that convey both spatial and temporal parameters of a specific action within a single cue. The current study used a real-time imitation task to examine whether PD affects the ability to re-enact changes in spatial characteristics of stepping actions, based solely on auditory information. In a second experimental session, these procedures were repeated using synthesized sounds derived from recordings of the kinetic interactions between the foot and walking surface. A third experimental session examined whether adaptations observed when participants walked to action-sounds were preserved when participants imagined either real recorded or synthesized sounds. Whilst healthy control participants were able to re-enact significant changes in SL in all cue conditions, these adaptations, in conjunction with reduced variability of SL were only observed in the PD group when walking to, or imagining the recorded sounds. The findings show that while recordings of stepping sounds convey action information to allow PD patients to re-enact and imagine spatial characteristics of gait, synthesis of sounds purely from gait kinetics is insufficient to evoke similar changes in behaviour, perhaps indicating that PD patients have a higher threshold to cue sensorimotor resonant responses. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Dietary soybean protein concentrate-induced intestinal disorder in marine farmed Atlantic salmon, Salmo salar is associated with alterations in gut microbiota.

PubMed

Green, Timothy J; Smullen, Richard; Barnes, Andrew C

2013-09-27

The aquaculture industry has made substantial progress in reducing the fishmeal content of feeds for carnivorous species, driven by demand for improved sustainability and reduced cost. Soybean protein concentrate (SPC) is an attractive replacement for fishmeal, but intestinal disorders have been reported in Atlantic salmon (Salmo salar) fed these diets at high seawater temperatures, with preliminary evidence suggesting SPC induces these disorders by altering the intestinal microbiota. We compared the intestinal microbiota of marine-farmed S. salar fed experimental diets with varying levels of SPC in mid- and late-summer. Terminal restriction fragment length polymorphism (T-RFLP) and 16S rRNA clone library analysis revealed the microbiota adherent to the intestinal tract of salmon is complex at the population level, but simple and highly variable at the individual level. Temporal changes were observed with the bacterial diversity increasing in the intestinal tract in late summer. A Verrucomicrobia was the most frequently observed ribotype in early summer, whilst an Aliivibrio was the most frequently observed ribotype in late summer. Feeding SPC to salmon increased the bacterial diversity of the intestinal tract and resulted in the presence of bacteria not normally associated with marine fish (Escherichia and Propionibacterium). These diet-induced changes to the intestinal-microbiome could be ameliorated by inclusion of a prebiotic (mannan-oligosaccharide or MOS) to the diet. None of the experimental diets induced inflammation of the intestine as assessed by histopathology and expression of inflammatory cytokines. Our results support the "dysbiosis" hypothesis that SPC adversely affects the intestinal microbiota of Atlantic salmon. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

Living with Hepatitis

MedlinePlus

... diseases. A recent article published in this year’s journal Alcoholism: Clinical & Experimental Research stated “43% of college students have ... • info@hepatitisfoundation.org • © 2015 8121 ...

Dielectric relaxation spectrum of undiluted poly(4-chlorostyrene), T≳Tg

NASA Astrophysics Data System (ADS)

Yoshihara, M.; Work, R. N.

1980-06-01

Dielectric relaxation characteristics of undiluted, atactic poly(4-chlorostyrene), P4CS, have been determined at temperatures 406 K⩽T⩽446 K from measurements made at frequencies 0.2 Hz⩽f⩽0.2 MHz. After effects of electrical conductivity are subtracted, it is found that the normalized complex dielectric constant K*=K'-i K″ can be represented quantitatively by the Havriliak-Negami (H-N) equation K*=[1+(iωτ0)1-α]-β, 0⩽α, β⩽1, except for a small, high frequency tail that appears in measurements made near the glass transition temperature, Tg. The parameter β is nearly constant, and α depends linearly on log τ0, where τ0 is a characteristic relaxation time. The parameters α and β extrapolate through values obtained from published data from P4CS solutions, and extrapolation to α=0 yields a value of τ0 which compares favorably with a published value for crankshaft motions of an equivalent isolated chain segment. These observations suggest that β may characterize effects of chain connectivity and α may describe effects of interactions of the surroundings with the chain. Experimental results are compared with alternative empirical and model-based representations of dielectric relaxation in polymers.

Trefoil knot timescales for reconnection and helicity

NASA Astrophysics Data System (ADS)

Kerr, Robert M.

2018-02-01

Three-dimensional images of evolving numerical trefoil vortex knots are used to study the growth and decay of the enstrophy and helicity. Negative helicity density (h< 0) plays several roles. First, during anti-parallel reconnection, sheets of oppositely signed helicity dissipation of equal magnitude on either side of the maximum of the enstrophy dissipation allow the global helicity { H } to be preserved through the first reconnection, as suggested theoretically (Laing et al 2015 Sci. Rep. 5 9224) and observed experimentally (Scheeler et al 2014a Proc. Natl Acad. Sci. 111 15350-5). Next, to maintain the growth of the enstrophy and positive helicity within the trefoil while { H } is preserved, h< 0 forms in the outer parts of the trefoil so long as the periodic boundaries do not interfere. To prevent that, the domain size {\\ell } is increased as the viscosity ν \\to 0. Combined, this allows two sets of trefoils to form a new scaling regime with linearly decreasing {(\\sqrt{ν }Z(t))}-1/2 up to common ν-independent times t x that the graphics show is when the first reconnection ends. During this phase there is good correspondence between the evolution of the simulated vortices and the reconnecting experimental trefoil of Kleckner and Irvine (2017 Nat. Phys. 9 253-8) when time is scaled by their respective nonlinear timescales t f . The timescales t f are based upon by the radii r f of the trefoils and their circulations Γ, so long as the strong camber of the experimental hydrofoil models is used to correct the published experimental circulations Γ that use only the flat-plate approximation.

Evaluating the quality of a cell counting measurement process via a dilution series experimental design.

PubMed

Sarkar, Sumona; Lund, Steven P; Vyzasatya, Ravi; Vanguri, Padmavathy; Elliott, John T; Plant, Anne L; Lin-Gibson, Sheng

2017-12-01

Cell counting measurements are critical in the research, development and manufacturing of cell-based products, yet determining cell quantity with accuracy and precision remains a challenge. Validating and evaluating a cell counting measurement process can be difficult because of the lack of appropriate reference material. Here we describe an experimental design and statistical analysis approach to evaluate the quality of a cell counting measurement process in the absence of appropriate reference materials or reference methods. The experimental design is based on a dilution series study with replicate samples and observations as well as measurement process controls. The statistical analysis evaluates the precision and proportionality of the cell counting measurement process and can be used to compare the quality of two or more counting methods. As an illustration of this approach, cell counting measurement processes (automated and manual methods) were compared for a human mesenchymal stromal cell (hMSC) preparation. For the hMSC preparation investigated, results indicated that the automated method performed better than the manual counting methods in terms of precision and proportionality. By conducting well controlled dilution series experimental designs coupled with appropriate statistical analysis, quantitative indicators of repeatability and proportionality can be calculated to provide an assessment of cell counting measurement quality. This approach does not rely on the use of a reference material or comparison to "gold standard" methods known to have limited assurance of accuracy and precision. The approach presented here may help the selection, optimization, and/or validation of a cell counting measurement process. Published by Elsevier Inc.

Effects of pleasant olfactory mental imagery on the arterial oxygenation in patients with open heart surgery: A randomized controlled trial.

PubMed

Rezaei-Nodehi, Masoud; Bagheri-Nesami, Masoumeh; Shorofi, Seyed Afshin; Yazdani-Charati, Jamshid; Ghafari, Rahman

2017-11-01

Arterial hypoxemia is one of the most common respiratory complications following cardiac surgery. This study was intended to examine the effects of pleasant olfactory mental imagery on postoperative hypoxemia in patients undergoing open heart surgery. This is a randomized controlled clinical trial. The sample consisted of 80 patients who were randomly assigned to either practice olfactory mental imagery (experimental group) or receive routine care (control group). A card with the image of roses was given to patients and they were asked to look at the image, visualize the scent of roses in the mind, and then sniff as much as possible, hold their breath for 2 s and eventually exhale slowly through the nose. This procedure was consecutively repeated five times. After a fifteen-minute break, patients proceeded to practice olfactory mental imagery with other fruit images. The experimental group executed the olfactory mental imagery for two hours in the morning and two hours in the afternoon on postoperative days 1 and 2. No statistically significant differences were observed between the experimental and control groups regarding sociodemographic characteristics, medical and surgical information. This study also demonstrated that the mean Spao2 was significantly higher in the experimental group (97.400 ± 1.70) than the control group (96.465 ± 1.70) (p = 0.015). The results of this study suggest that olfactory mental imagery can improve arterial oxygenation in patients with cardiac surgery. Copyright © 2017. Published by Elsevier Ltd.

Advantages of the experimental animal hollow organ mechanical testing system for the rat colon rupture pressure test.

PubMed

Ji, Chengdong; Guo, Xuan; Li, Zhen; Qian, Shuwen; Zheng, Feng; Qin, Haiqing

2013-01-01

Many studies have been conducted on colorectal anastomotic leakage to reduce the incidence of anastomotic leakage. However, how to precisely determine if the bowel can withstand the pressure of a colorectal anastomosis experiment, which is called anastomotic bursting pressure, has not been determined. A task force developed the experimental animal hollow organ mechanical testing system to provide precise measurement of the maximum pressure that an anastomotic colon can withstand, and to compare it with the commonly used method such as the mercury and air bag pressure manometer in a rat colon rupture pressure test. Forty-five male Sprague-Dawley rats were randomly divided into the manual ball manometry (H) group, the tracing machine manometry pressure gauge head (MP) group, and the experimental animal hollow organ mechanical testing system (ME) group. The rats in each group were subjected to a cut colon rupture pressure test after injecting anesthesia in the tail vein. Colonic end-to-end anastomosis was performed, and the rats were rested for 1 week before anastomotic bursting pressure was determined by one of the three methods. No differences were observed between the normal colon rupture pressure and colonic anastomotic bursting pressure, which were determined using the three manometry methods. However, several advantages, such as reduction in errors, were identified in the ME group. Different types of manometry methods can be applied to the normal rat colon, but the colonic anastomotic bursting pressure test using the experimental animal hollow organ mechanical testing system is superior to traditional methods. Copyright © 2013 Surgical Associates Ltd. Published by Elsevier Ltd. All rights reserved.

A critical state model for mudrock behavior at high stress levels

NASA Astrophysics Data System (ADS)

Heidari, M.; Nikolinakou, M. A.; Flemings, P. B.

2016-12-01

Recent experimental work has documented that the compression behavior, friction angle, and lateral stress ratio (k0) of mudrocks vary over the stress range of 1 to 100 MPa. We integrate these observations into a critical state model. The internal friction angle and the slope of the compression curve are key parameters in a mudrock critical state model. Published models assume that these parameters do not depend on the stress level, and hence predict lateral stress and normalized strength ratios that do not change with the stress level. However, recent experimental data on resedimented mudrock samples from Eugene Island, Gulf of Mexico, demonstrate that all these parameters vary considerably with the stress level (Casey and Germaine, 2013; Casey et al., 2015). To represent these variations, we develop an enhanced critical state model that uses a stress-level-dependent friction angle and a curvilinear compression curve. We show that this enhanced model predicts the observed variations of the lateral stress and strength ratios. The successful performance of our model indicates that the critical state theory developed for soil can predict mudrock nonlinear behavior at high stress levels and thus can be used in modeling geologic systems. Casey, B., Germaine, J., 2013. Stress Dependence of Shear Strength in Fine-Grained Soils and Correlations with Liquid Limit. J. Geotech. Geoenviron. Eng. 139, 1709-1717. Casey, B., Germaine, J., Flemings, P.B., Fahy, B.P., 2015. Estimating horizontal stresses for mudrocks under one-dimensional compression. Mar. Pet. Geol. 65, 178-186.

The Fraser Experimental Forest ... its work and aims

Treesearch

L. D. Love

1960-01-01

In 1937 the Fraser Experimental Forest was established in the heart of the Central Rocky Mountains near the Continental Divide 65 miles north and west of Denver. This 36-square-mile outdoor research laboratory is well suited for the study of pressing problems related to water yield from high-elevation forests and alpine areas. (Originally published in 1952; revised in...

Calibration of streamflow gauging stations at the Tenderfoot Creek Experimental Forest

Treesearch

Scott W. Woods

2007-01-01

We used tracer based methods to calibrate eleven streamflow gauging stations at the Tenderfoot Creek Experimental Forest in western Montana. At six of the stations the measured flows were consistent with the existing rating curves. At Lower and Upper Stringer Creek, Upper Sun Creek and Upper Tenderfoot Creek the published flows, based on the existing rating curves,...

Effectiveness of Mathematical Word Problem Solving Interventions for Students with Learning Disabilities and Mathematics Difficulties: A Meta-Analysis

ERIC Educational Resources Information Center

Lein, Amy E.

2016-01-01

This meta-analysis synthesized the findings from 23 published and five unpublished experimental or quasi-experimental group design studies on word problem-solving instruction for K-12 students with learning disabilities (LD) and mathematics difficulties (MD). A secondary purpose of this meta-analysis was to analyze the relation between treatment…

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

Seapan, M.; Crynes, B.L.; Dale, S.

The objectives of this study were to analyze alternate crudes kinetic hydrotreatment data in the literature, develop a mathematical model for interpretation of these data, develop an experimental procedure and apparatus to collect accurate kinetic data, and finally, to combine the model and experimental data to develop a general model which, with a few experimental parameters, could be used in design of future hydrotreatment processes. These objectives were to cover a four year program (1980 to 1984) and were subjective to sufficient funding. Only partial funding has been available thus far to cover activities for two years. A hydrotreatment datamore » base is developed which contains over 2000 citations, stored in a microcomputer. About 50% of these are reviewed, classified and can be identified by feedstock, catalyst, reactor type and other process characteristics. Tests of published hydrodesulfurization data indicate the problems with simple n-th order, global kinetic models, and point to the value of developing intrinsic reaction kinetic models to describe the reaction processes. A Langmuir-Hinshelwood kinetic model coupled with a plug flow reactor design equation has been developed and used for published data evaluation. An experimental system and procedure have been designed and constructed, which can be used for kinetic studies. 30 references, 4 tables.« less

Favorable results from the use of herbal and plant products in inflammatory bowel disease: evidence from experimental animal studies

PubMed Central

Triantafillidis, John K.; Triantafyllidi, Aikaterini; Vagianos, Constantinos; Papalois, Apostolos

2016-01-01

The use of herbal therapy for inflammatory bowel disease is increasing worldwide. The aim of this study was to review the available literature on the efficacy of herbal therapy in experimental colitis. All relevant studies published in Medline and Embase up to June 2015 have been reviewed. The results of bowel histology and serum parameters have been recorded. A satisfactory number of published experimental studies, and a quite large one of both herbal and plant products tested in different studies have been reported. The results showed that in the majority of the studies, herbal therapy reduced the inflammatory activity of experimental colitis and diminished the levels of many inflammatory indices, including serum cytokines and indices of oxidative stress. The most promising plant and herbal products were tormentil extracts, wormwoodherb, Aloe vera, germinated barley foodstuff, curcumin, Boswellia serrata, Panax notoginseng, Ixeris dentata, green tea, Cordia dichotoma, Plantago lanceolata, Iridoidglycosides, and mastic gum. Herbal therapies exert their therapeutic benefit via various mechanisms, including immune regulation, anti-oxidant activity, inhibition of leukotriene B4 and nuclear factor-κB, and antiplatelet activity. Large, double-blind clinical studies assessing these natural substances should be urgently conducted. PMID:27366027

Quasi-experimental Studies in the Fields of Infection Control and Antibiotic Resistance, Ten Years Later: A Systematic Review.

PubMed

Alsaggaf, Rotana; O'Hara, Lyndsay M; Stafford, Kristen A; Leekha, Surbhi; Harris, Anthony D

2018-02-01

OBJECTIVE A systematic review of quasi-experimental studies in the field of infectious diseases was published in 2005. The aim of this study was to assess improvements in the design and reporting of quasi-experiments 10 years after the initial review. We also aimed to report the statistical methods used to analyze quasi-experimental data. DESIGN Systematic review of articles published from January 1, 2013, to December 31, 2014, in 4 major infectious disease journals. METHODS Quasi-experimental studies focused on infection control and antibiotic resistance were identified and classified based on 4 criteria: (1) type of quasi-experimental design used, (2) justification of the use of the design, (3) use of correct nomenclature to describe the design, and (4) statistical methods used. RESULTS Of 2,600 articles, 173 (7%) featured a quasi-experimental design, compared to 73 of 2,320 articles (3%) in the previous review (P<.01). Moreover, 21 articles (12%) utilized a study design with a control group; 6 (3.5%) justified the use of a quasi-experimental design; and 68 (39%) identified their design using the correct nomenclature. In addition, 2-group statistical tests were used in 75 studies (43%); 58 studies (34%) used standard regression analysis; 18 (10%) used segmented regression analysis; 7 (4%) used standard time-series analysis; 5 (3%) used segmented time-series analysis; and 10 (6%) did not utilize statistical methods for comparisons. CONCLUSIONS While some progress occurred over the decade, it is crucial to continue improving the design and reporting of quasi-experimental studies in the fields of infection control and antibiotic resistance to better evaluate the effectiveness of important interventions. Infect Control Hosp Epidemiol 2018;39:170-176.

PUBLISHER'S NOTE: Microfabrication by localized electrochemical deposition: experimental investigation and theoretical modelling

NASA Astrophysics Data System (ADS)

Said, R. A.

2004-07-01

During 2003, Dr R A Said published essentially duplicate versions of a paper in two archival journals: Nanotechnology and the Journal of The Electrochemical Society. The papers in question were: `Microfabrication by localized electrochemical deposition: experimental investigation and theoretical modelling' (2003 Nanotechnology 14 523) and `Shape formation of microstructures fabricated by localized electrochemical deposition' (2003 J. Electrochem. Soc. 150 C549). The two papers were submitted, revised, and published at essentially the same time. The papers used the same figures and neither paper referenced the other. Nanotechnology requires a signed copyright-transfer form assigning copyright in articles published to Institute of Physics Publishing, and the Journal of The Electrochemical Society requires the same for The Electrochemical Society. It is a tradition of long standing, stated in the information for contributors, that submission implies that the work has not been submitted, copyrighted, or accepted for publication elsewhere. Hence, duplicate publication not only raises legal questions and represents a serious breach of scientific ethics, but also leads to an unnecessary imposition on readers', referees', and editors' time. We regard this infraction as a serious matter. An apology from the author for this grave error is printed below. Author's apology I have mistakenly published similar results in two manuscripts in Nanotechnology and in the Journal of The Electrochemical Society, as stated above. I am responsible for this error. I agree with the Editors that such a practice should not have occurred, and I would like to sincerely apologize to Nanotechnology and the Journal of The Electrochemical Society, their publishers, and their readers for this matter. I will take actions in the future to prevent the occurrence of similar incidents. R A Said

Identifying process and outcome indicators of successful transitions from child to adult mental health services: protocol for a scoping review.

PubMed

Cleverley, Kristin; Bennett, Kathryn; Jeffs, Lianne

2016-07-05

A significant proportion of youth need to transition from child and adolescent mental health services (CAMHS) to adult mental health services (AMHS); however, the transition process is not well understood and often experienced poorly by youth. In the effort to design and evaluate standards of practice for transitions, there is a need to identify key elements of a successful transition. The objectives of this scoping review are to: (1) identify definitions of successful transitions from CAMHS to AMHS; and (2) identify indicators that have been used to measure CAMHS-AMHS transition care processes and quality, and outcomes. We will search 8 electronic bibliographic databases from 1980 to 2016 (eg, Medline, EMBASE, PsycINFO), professional associations, policy documents, and other grey literature to identify relevant material. We will include experimental, quasi-experimental, observational studies, and non-research studies (guidelines, narrative reviews, policy documents) examining the transition from CAMHS to AMHS. 2 raters will independently screen each retrieved title and abstract for eligibility using the study inclusion criteria (level 1), and then will independently assess full-text articles to determine if these meet the inclusion criteria (level 2). Data extraction will be completed and results will be synthesised both quantitatively and qualitatively. The results of the scoping review will be used to develop a set of indicators that will be prioritised and evaluated in a Delphi consensus study. This will serve as a foundation for the development of the first instrument to assess the quality and success of CAMHS-AMHS transitions. Ethics approval is not required for this scoping study. 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/

Epigenetic regulation in allergic diseases and related studies

PubMed Central

Kuo, Chang-Hung; Hsieh, Chong-Chao; Lee, Min-Sheng; Chang, Kai-Ting; Kuo, Hsuan-Fu

2014-01-01

Asthma, a chronic inflammatory disorder of the airway, has features of both heritability as well as environmental influences which can be introduced in utero exposures and modified through aging, and the features may attribute to epigenetic regulation. Epigenetic regulation explains the association between early prenatal maternal smoking and later asthma-related outcomes. Epigenetic marks (DNA methylation, modifications of histone tails or noncoding RNAs) work with other components of the cellular regulatory machinery to control the levels of expressed genes, and several allergy- and asthma-related genes have been found to be susceptible to epigenetic regulation, including genes important to T-effector pathways (IFN-γ, interleukin [IL] 4, IL-13, IL-17) and T-regulatory pathways (FoxP3). Therefore, the mechanism by which epigenetic regulation contributes to allergic diseases is a critical issue. In the past most published experimental work, with few exceptions, has only comprised small observational studies and models in cell systems and animals. However, very recently exciting and elegant experimental studies and novel translational research works were published with new and advanced technologies investigating epigenetic mark on a genomic scale and comprehensive approaches to data analysis. Interestingly, a potential link between exposure to environmental pollutants and the occurrence of allergic diseases is revealed recently, particular in developed and industrialized countries, and endocrine disrupting chemicals (EDCs) as environmental hormone may play a key role. This review addresses the important question of how EDCs (nonylphenol, 4 octylphenol, and phthalates) influences on asthma-related gene expression via epigenetic regulation in immune cells, and how anti-asthmatic agents prohibit expression of inflammatory genes via epigenetic modification. The discovery and validation of epigenetic biomarkers linking exposure to allergic diseases might lead to better epigenotyping of risk, prognosis, treatment prediction, and development of novel therapies. PMID:24527405

Mitochondrial Mutation Rate, Spectrum and Heteroplasmy in Caenorhabditis elegans Spontaneous Mutation Accumulation Lines of Differing Population Size.

PubMed

Konrad, Anke; Thompson, Owen; Waterston, Robert H; Moerman, Donald G; Keightley, Peter D; Bergthorsson, Ulfar; Katju, Vaishali

2017-06-01

Mitochondrial genomes of metazoans, given their elevated rates of evolution, have served as pivotal markers for phylogeographic studies and recent phylogenetic events. In order to determine the dynamics of spontaneous mitochondrial mutations in small populations in the absence and presence of selection, we evolved mutation accumulation (MA) lines of Caenorhabditis elegans in parallel over 409 consecutive generations at three varying population sizes of N = 1, 10, and 100 hermaphrodites. The N =1 populations should have a minimal influence of natural selection to provide the spontaneous mutation rate and the expected rate of neutral evolution, whereas larger population sizes should experience increasing intensity of selection. New mutations were identified by Illumina paired-end sequencing of 86 mtDNA genomes across 35 experimental lines and compared with published genomes of natural isolates. The spontaneous mitochondrial mutation rate was estimated at 1.05 × 10-7/site/generation. A strong G/C→A/T mutational bias was observed in both the MA lines and the natural isolates. This suggests that the low G + C content at synonymous sites is the product of mutation bias rather than selection as previously proposed. The mitochondrial effective population size per worm generation was estimated to be 62. Although it was previously concluded that heteroplasmy was rare in C. elegans, the vast majority of mutations in this study were heteroplasmic despite an experimental regime exceeding 400 generations. The frequencies of frameshift and nonsynonymous mutations were negatively correlated with population size, which suggests their deleterious effects on fitness and a potent role for selection in their eradication. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Benefits of smoking bans on preterm and early-term births: a natural experimental design in Switzerland.

PubMed

Vicedo-Cabrera, Ana M; Schindler, Christian; Radovanovic, Dragana; Grize, Leticia; Witassek, Fabienne; Dratva, Julia; Röösli, Martin; Perez, Laura

2016-12-01

Birth outcomes are relevant for future children's heath. Capitalising on a natural experimental design in Switzerland, we evaluated how regional smoking bans introduced at different time points affected birth outcomes, including preterm and early-term births. We used birth registry data of all singleton neonates born in Switzerland (2007-2012). We developed canton-specific interrupted time-series followed by random meta-analysis to evaluate the benefits of smoking bans on preterm (<37 gestational weeks) and early-term (37-38 gestational weeks) births. Heterogeneity across type of ban and contextual characteristics was explored through metaregression. A time-to-event approach was used for evaluating duration of pregnancy under the smoking bans and effects, taking into account individual maternal factors. We observed a decrease in the risk of preterm birth of 3.6% (95% CI, -9.3% to 2.5%), and early-term birth of 5.0% (95% CI -7.5% to -2.5%). Results showed a clear dose-response relationship. Greater risk reductions were obtained for preterm births in areas with more comprehensive bans (-6.8%; 95% CI -12.1% to 0.1%), and for pregnancies with the longest gestational time under smoking bans (HR, 0.991; 95% CI 0.984 to 0.997 per 10% increase in duration). Benefits were unequal across outcomes and characteristics of cantons and mothers. Smoking bans resulted in improved birth outcomes in Switzerland with cantons that adopted more comprehensive smoking bans achieving greater benefits. Early-term births constitute a previously ignored though important group. 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/.

The impact of intervening in green space in Dutch deprived neighbourhoods on physical activity and general health: results from the quasi-experimental URBAN40 study.

PubMed

Droomers, Mariël; Jongeneel-Grimen, Birthe; Kramer, Daniëlle; de Vries, Sjerp; Kremers, Stef; Bruggink, Jan-Willem; van Oers, Hans; Kunst, Anton E; Stronks, Karien

2016-02-01

Many problems concentrate in deprived neighbourhoods, among which is poor health. One possible way to address these health problems is to invest in the green space in deprived neighbourhoods. The number of evaluations of the public health impact of actual changes in neighbourhood green space is still limited. This study investigated the impact of real-life changes in the quality or quantity of green space in severely deprived neighbourhoods on physical activity and perceived general health. Repeated cross-sectional surveys from 2004 till 2011 yielded self-reported information on leisure time walking, cycling and sports, and perceived general health of 48,132 adult residents. We fitted generalised mixed models to assess the rate of change per half year, estimate the linear trend, and the change in trends before and after the start of the urban regeneration mid-2008. Using a quasi-experimental design, we compared the trends in the intervention neighbourhoods with different selections of control areas. The deprived neighbourhoods that intervened in green space did not show more favourable changes in the trend of physical activity and good general health compared to all the different groups of control areas. We did not observe short-term positive effects on physical activity and general health among adults from improvements in green space in deprived neighbourhoods. This suggests that greening interventions that have been carried out in the context of the Dutch District Approach did not achieve short-term health gains among adults. 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/

Influence of premium versus value brand names on the smoking experience in a plain packaging environment: an experimental study.

PubMed

Skaczkowski, Gemma; Durkin, Sarah; Kashima, Yoshihisa; Wakefield, Melanie

2017-01-16

To examine the effect of branding, as indicated by brand name, on evaluation of the cigarette smoking experience. Between-subjects and within-subjects experimental study. Participants were randomly allocated to smoke a cigarette from a pack featuring a premium brand name and a cigarette from a pack featuring a value brand name. Within each condition, participants unknowingly smoked two identical cigarettes (either two premium or two value cigarettes). Australia, October 2014, 2 years after tobacco plain packaging implementation. 81 current cigarette smokers aged 19-39 years. From apparently premium and value brand-name packs, 40 smokers were allocated to smoke the same actual premium cigarettes and 41 were allocated to smoke the same actual value cigarettes. Experienced taste (flavour, satisfaction, enjoyment, quality, liking, mouthfeel and aftertaste), harshness, dryness, staleness, harm/strength measures (strength, tar, lightness, volume of smoke), draw effort and purchase intent. Cigarettes given a premium brand name were rated as having a better taste, were less harsh and less dry than identical cigarettes given a value brand name. This pattern was observed irrespective of whether the two packs actually contained premium or value cigarettes. These effects were specific: the brand name did not influence ratings of cigarette variant attributes (strength, tar, volume of smoke, lightness and draw effort). Despite the belief that brand names represent genuine differences between cigarette products, the results suggest that at least some of this perceived sensory difference is attributable to brand image. 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/.

A systematic review of financial incentives for dietary behavior change.

PubMed

Purnell, Jason Q; Gernes, Rebecca; Stein, Rick; Sherraden, Margaret S; Knoblock-Hahn, Amy

2014-07-01

In light of the obesity epidemic, there is growing interest in the use of financial incentives for dietary behavior change. Previous reviews of the literature have focused on randomized controlled trials and found mixed results. The purpose of this systematic review is to update and expand on previous reviews by considering a broader range of study designs, including randomized controlled trials, quasi-experimental, observational, and simulation studies testing the use of financial incentives to change dietary behavior and to inform both dietetic practice and research. The review was guided by theoretical consideration of the type of incentive used based on the principles of operant conditioning. There was further examination of whether studies were carried out with an institutional focus. Studies published between 2006 and 2012 were selected for review, and data were extracted regarding study population, intervention design, outcome measures, study duration and follow-up, and key findings. Twelve studies meeting selection criteria were reviewed, with 11 finding a positive association between incentives and dietary behavior change in the short term. All studies pointed to more specific information on the type, timing, and magnitude of incentives needed to motivate individuals to change behavior, the types of incentives and disincentives most likely to affect the behavior of various socioeconomic groups, and promising approaches for potential policy and practice innovations. Limitations of the studies are noted, including the lack of theoretical guidance in the selection of incentive structures and the absence of basic experimental data. Future research should consider these factors, even as policy makers and practitioners continue to experiment with this potentially useful approach to addressing obesity. Copyright © 2014 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved.

"They Sweat for Science": The Harvard Fatigue Laboratory and Self-Experimentation in American Exercise Physiology.

PubMed

Johnson, Andi

2015-08-01

In many scientific fields, the practice of self-experimentation waned over the course of the twentieth century. For exercise physiologists working today, however, the practice of self-experimentation is alive and well. This paper considers the role of the Harvard Fatigue Laboratory and its scientific director, D. Bruce Dill, in legitimizing the practice of self-experimentation in exercise physiology. Descriptions of self-experimentation are drawn from papers published by members of the Harvard Fatigue Lab. Attention is paid to the ethical and practical justifications for self-experimentation in both the lab and the field. Born out of the practical, immediate demands of fatigue protocols, self-experimentation performed the long-term, epistemological function of uniting physiological data across time and space, enabling researchers to contribute to a general human biology program.

Efficacy and safety of sunitinib alternate day regimen in patients with metastatic renal cell carcinoma in Japan: Comparison with standard 4/2 schedule.

PubMed

Ohba, Kojiro; Miyata, Yasuyoshi; Yasuda, Takuji; Asai, Akihiro; Mitsunari, Kensuke; Matsuo, Tomohiro; Mochizuki, Yasushi; Matsunaga, Noriko; Sakai, Hideki

2018-06-01

Sunitinib is a standard agent for metastatic renal cell carcinoma (mRCC). The standard schedule, 4 weeks-on followed by 2 weeks-off (4/2 schedule), often does not maintain an adequate dosage because of the severe adverse events (AEs). We compared the efficacy and safety of an alternative every other day (q.a.d.) dosing with that of the 4/2 schedule in mRCC patients. Of the 55 Japanese patients, 32 and 23 were administered 4/2 (standard group) and q.a.d. schedules (50 or 37.5 mg, every other day; experimental groups), respectively. The AEs, anticancer effects, and trough plasma concentrations of sunitinib were compared between them. The most common AE in the standard group was thrombocytopenia (43.2%), but it was observed in only two patients in the experimental group (8.7%). Although leukopenia and hand-foot syndrome were both detected in six patients (18.8%) in the standard group, no patients had these AEs in the experimental group. The incidence of dose interruption in the experimental group (21.7%) was significantly lower than that in the standard group was (59.4%, P = 0.005). Time to progression (TTP) and overall survival (OS) of the experimental group were better than those of the standard group (P < 0.001 and P = 0.002, respectively). Mean plasma levels in the experimental group (64.83 ng/mL) were significantly lower than those in the standard group (135.82 ng/mL, P < 0.001) were. Sunitinib administered q.a.d. was safe and effective for mRCC patients. We speculate that the persistent optimal drug plasma concentrations contributed to these effects. © 2018 The Authors. Asia-Pacific Journal of Clinical Oncology Published by John Wiley & Sons Australia, Ltd.

Evaluations of Energy Spectra of Neutrons Emitted Promptly in Neutron-induced Fission of 235 U and 239 Pu

DOE PAGES

Neudecker, Denise; Talou, Patrick; Kawano, Toshihiko; ...

2018-02-01

The energy spectra of neutrons emitted promptly in the neutron-induced fission reactions of 235U and 239Pu were re-evaluated for ENDF/B-VIII.0. The evaluations presented here are based on a careful modeling of all relevant physics processes, an extensive analysis of experimental data and a detailed quantification of pertinent uncertainties. Energy spectra of neutrons emitted in up to fourth chance fission are considered and both compound and pre-equilibrium processes are included. Also, important nuclear model parameters, such as the average total kinetic energy of the fission fragments and the multiple chance fission probabilities, and their uncertainties are estimated based on experimental knowledge,more » model information and evaluated data. In addition to experimental information already available for ENDF/B-VII.1, these new evaluations make use of recently published experimental data either of high precision or spanning a broad incident energy range, information on legacy measurements explaining discrepancies and recently measured data of the average total kinetic energy as a function of incident neutron energy. The resulting evaluated data and covariances agree well with the experimental database used for the evaluation. However, the evaluated spectra are softer than the 235U and 239Pu ENDF/B-VII.1, JENDL-4.0 and JEFF-3.2 evaluations for incident neutron energies E inc ≤ 1.5 MeV and E inc ≤ 5 MeV, respectively. For E inc > 5 MeV, the evaluated spectra show structures due to the improved modeling which are not present in ENDF/B-VII.1 and JEFF-3.2 but can be observed in JENDL-4.0 evaluations. Part of these new evaluations were adopted for ENDF/B-VIII.0, while the ENDF/B-VII.1 239Pu PFNS was retained for E inc ≤ 5 MeV awaiting more conclusive experimental evidence.« less

Evaluations of Energy Spectra of Neutrons Emitted Promptly in Neutron-induced Fission of 235U and 239Pu

NASA Astrophysics Data System (ADS)

Neudecker, D.; Talou, P.; Kawano, T.; Kahler, A. C.; White, M. C.; Taddeucci, T. N.; Haight, R. C.; Kiedrowski, B.; O'Donnell, J. M.; Gomez, J. A.; Kelly, K. J.; Devlin, M.; Rising, M. E.

2018-02-01

The energy spectra of neutrons emitted promptly in the neutron-induced fission reactions of 235U and 239Pu were re-evaluated for ENDF/B-VIII.0. These evaluations are based on a careful modeling of all relevant physics processes, an extensive analysis of experimental data and a detailed quantification of pertinent uncertainties. Energy spectra of neutrons emitted in up to fourth chance fission are considered and both compound and pre-equilibrium processes are included. Also, important nuclear model parameters, such as the average total kinetic energy of the fission fragments and the multiple chance fission probabilities, and their uncertainties are estimated based on experimental knowledge, model information and evaluated data. In addition to experimental information already available for ENDF/B-VII.1, these new evaluations make use of recently published experimental data either of high precision or spanning a broad incident energy range, information on legacy measurements explaining discrepancies and recently measured data of the average total kinetic energy as a function of incident neutron energy. The resulting evaluated data and covariances agree well with the experimental database used for the evaluation. However, the evaluated spectra are softer than the 235U and 239Pu ENDF/B-VII.1, JENDL-4.0 and JEFF-3.2 evaluations for incident neutron energies Einc ≤ 1.5 MeV and Einc ≤ 5 MeV, respectively. For Einc > 5 MeV, the evaluated spectra show structures due to the improved modeling which are not present in ENDF/B-VII.1 and JEFF-3.2 but can be observed in JENDL-4.0 evaluations. Part of these new evaluations were adopted for ENDF/B-VIII.0, while the ENDF/B-VII.1 239Pu PFNS was retained for Einc ≤ 5 MeV awaiting more conclusive experimental evidence.

Evaluations of Energy Spectra of Neutrons Emitted Promptly in Neutron-induced Fission of 235 U and 239 Pu

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

Neudecker, Denise; Talou, Patrick; Kawano, Toshihiko

The energy spectra of neutrons emitted promptly in the neutron-induced fission reactions of 235U and 239Pu were re-evaluated for ENDF/B-VIII.0. The evaluations presented here are based on a careful modeling of all relevant physics processes, an extensive analysis of experimental data and a detailed quantification of pertinent uncertainties. Energy spectra of neutrons emitted in up to fourth chance fission are considered and both compound and pre-equilibrium processes are included. Also, important nuclear model parameters, such as the average total kinetic energy of the fission fragments and the multiple chance fission probabilities, and their uncertainties are estimated based on experimental knowledge,more » model information and evaluated data. In addition to experimental information already available for ENDF/B-VII.1, these new evaluations make use of recently published experimental data either of high precision or spanning a broad incident energy range, information on legacy measurements explaining discrepancies and recently measured data of the average total kinetic energy as a function of incident neutron energy. The resulting evaluated data and covariances agree well with the experimental database used for the evaluation. However, the evaluated spectra are softer than the 235U and 239Pu ENDF/B-VII.1, JENDL-4.0 and JEFF-3.2 evaluations for incident neutron energies E inc ≤ 1.5 MeV and E inc ≤ 5 MeV, respectively. For E inc > 5 MeV, the evaluated spectra show structures due to the improved modeling which are not present in ENDF/B-VII.1 and JEFF-3.2 but can be observed in JENDL-4.0 evaluations. Part of these new evaluations were adopted for ENDF/B-VIII.0, while the ENDF/B-VII.1 239Pu PFNS was retained for E inc ≤ 5 MeV awaiting more conclusive experimental evidence.« less

The Behavior of IAPWS-95 from 250 to 300 K and Pressures up to 400 MPa: Evaluation Based on Recently Derived Property Data

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

Wagner, Wolfgang, E-mail: Wagner@thermo.rub.de; Thol, Monika

2015-12-15

Over the past several years, considerable scientific and technical interest has been focused on accurate thermodynamic properties of fluid water covering part of the subcooled (metastable) region and the stable liquid from the melting line up to about 300 K and pressures up to several hundred MPa. Between 2000 and 2010, experimental density data were published whose accuracy was not completely clear. The scientific standard equation of state for fluid water, the IAPWS-95 formulation, was developed on the basis of experimental data for thermodynamic properties that were available by 1995. In this work, it is examined how IAPWS-95 behaves withmore » respect to the experimental data published after 1995. This investigation is carried out for temperatures from 250 to 300 K and pressures up to 400 MPa. The starting point is the assessment of the current data situation. This was mainly performed on the basis of data for the density, expansivity, compressibility, and isobaric heat capacity, which were derived in 2015 from very accurate speed-of-sound data. Apart from experimental data and these derived data, property values calculated from the recently published equation of state for this region of Holten et al. (2014) were also used. As a result, the unclear data situation could be clarified, and uncertainty values could be estimated for the investigated properties. In the region described above, detailed comparisons show that IAPWS-95 is able to represent the latest experimental data for the density, expansivity, compressibility, speed of sound, and isobaric heat capacity to within the uncertainties given in the release on IAPWS-95. Since the release does not contain uncertainty estimates for expansivities and compressibilities, the statement relates to the error propagation of the given uncertainty in density. Due to the lack of experimental data for the isobaric heat capacity for pressures above 100 MPa, no uncertainty estimates are given in the release for this pressure range. Results of the investigation of IAPWS-95 concerning its behavior with regard to the isobaric heat capacity in the high-pressure low-temperature region are also presented. Comparisons with very accurate speed-of-sound data published in 2012 showed that the uncertainty estimates of IAPWS-95 in speed of sound could be decreased for temperatures from 283 to 473 K and pressures up to 400 MPa.« less

Thermoelectric Properties of Selenides Spinels

NASA Technical Reports Server (NTRS)

Snyder, G.; Caillat, T.; Fleurial, J-P.

2000-01-01

Many compounds with the spinel structure type have been analyzed for their thermoelectric properties. Published data was used to augment experimental results presented here to select promising thermoelectric spinels.

What Is the Methodologic Quality of Human Therapy Studies in ISI Surgical Publications?

PubMed Central

Manterola, Carlos; Pineda, Viviana; Vial, Manuel; Losada, Héctor

2006-01-01

Objective: To determine the methodologic quality of therapy articles about humans published in ISI surgical journals, and to explore the association between methodologic quality, origin, and subject matter. Summary Background Data: It is supposed that ISI journals contain the best methodologic articles. Methods: This is a bibliometric study. All journals listed in the 2002 ISI under the subject heading of “Surgery” were included. A simple randomized sampling was conducted for selected journals (Annals of Surgery, The American Surgeon, Archives of Surgery, British Journal of Surgery, European Journal of Surgery, Journal of the American College of Surgeons, Surgery, and World Journal of Surgery). Published articles related to therapy on humans of the selected journals were reviewed and analyzed. All kinds of clinical designs were considered, excluding editorials, review articles, letters to the editor, and experimental studies. The variables considered were: place of origin, design, and the methodologic quality of articles, which was determined by applying a valid and reliable scale. The review was performed interchangeably and independently by 2 research teams. Descriptive and analytical statistics were used. Statistical significance was defined as P values less than 1%. Results: A total of 653 articles were studied. Studies came predominantly from the United States and Europe (43.6% and 36.8%, respectively). The subject areas most frequently found were digestive and hepatobiliopancreatic surgery (29.1% and 24.5%, respectively). Average and median methodologic quality scores of the entire series were 11.6 ± 4.9 points and 11 points, respectively. The association between methodologic quality and journals was determined. Also, the association between methodologic quality and origin was observed, but no association with subject area was verified. Conclusions: The methodologic quality of therapy articles published in the journals analyzed is low; however, statistical significance was determined between them. Association was observed between methodologic quality and origin, but not with subject matter. PMID:17060778

[Benefits of using the cutometer to evaluate the effectiveness of skin treatments in plastic and maxillofacial surgery].

PubMed

Stroumza, N; Bosc, R; Hersant, B; Hermeziu, O; Meningaud, J-P

2015-04-01

Evaluating skin properties is often too subjective. Using the cutometer allows one to take objective measures of certain mechanic properties of the skin such as visco-elasticity. The aim of this article is to evaluate through a review of existing literature the advantages and the limits of the cutometer and to propose an improvement. The selection of articles has been conducted with the PubMed database in order to identify all publications concerning the cutometer up until September 2013. The analysis criteria were: (1) quantitative distribution of articles from the first publication until today; (2) qualitative distribution over the various medical fields. The articles have been organized in 3 groups: medical, surgical and burns; (3) list of biases in the interpretation of results and limits of this measuring tool. One hundred and twenty-nine publications have been included. The first article regarding the cutometer was published in 1994. We observe an increase in the number of publications after 2005. Most of the articles were published in medical journals of dermatology or cosmetology (83%), only 9% of articles have been published in burn study journals and 8% in surgical journals. The pressure applied by the experimenter constitutes the main measure bias. The use of an external device maintaining the probe with an invariable pressure corresponding to its own weight enables more reliable results all the while limiting the inter- and intra-individual variability. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Kinetic modelling of a diesel-polluted clayey soil bioremediation process.

PubMed

Fernández, Engracia Lacasa; Merlo, Elena Moliterni; Mayor, Lourdes Rodríguez; Camacho, José Villaseñor

2016-07-01

A mathematical model is proposed to describe a diesel-polluted clayey soil bioremediation process. The reaction system under study was considered a completely mixed closed batch reactor, which initially contacted a soil matrix polluted with diesel hydrocarbons, an aqueous liquid-specific culture medium and a microbial inoculation. The model coupled the mass transfer phenomena and the distribution of hydrocarbons among four phases (solid, S; water, A; non-aqueous liquid, NAPL; and air, V) with Monod kinetics. In the first step, the model simulating abiotic conditions was used to estimate only the mass transfer coefficients. In the second step, the model including both mass transfer and biodegradation phenomena was used to estimate the biological kinetic and stoichiometric parameters. In both situations, the model predictions were validated with experimental data that corresponded to previous research by the same authors. A correct fit between the model predictions and the experimental data was observed because the modelling curves captured the major trends for the diesel distribution in each phase. The model parameters were compared to different previously reported values found in the literature. Pearson correlation coefficients were used to show the reproducibility level of the model. Copyright © 2016. Published by Elsevier B.V.

Is there a role for IGF-1 in the development of second primary cancers?

PubMed

Shanmugalingam, Thurkaa; Bosco, Cecilia; Ridley, Anne J; Van Hemelrijck, Mieke

2016-11-01

Cancer survival rates are increasing, and as a result, more cancer survivors are exposed to the risk of developing a second primary cancer (SPC). It has been hypothesized that one of the underlying mechanisms for this risk could be mediated by variations in insulin-like growth factor-1 (IGF-1). This review summarizes the current epidemiological evidence to identify whether IGF-1 plays a role in the development of SPCs. IGF-1 is known to promote cancer development by inhibiting apoptosis and stimulating cell proliferation. Epidemiological studies have reported a positive association between circulating IGF-1 levels and various primary cancers, such as breast, colorectal, and prostate cancer. The role of IGF-1 in increasing SPC risk has been explored less. Nonetheless, several experimental studies have observed a deregulation of the IGF-1 pathway, which may explain the association between IGF-1 and SPCs. Thus, measuring serum IGF-1 may serve as a useful marker in assessing the risk of SPCs, and therefore, more translational experimental and epidemiological studies are needed to further disentangle the role of IGF-1 in the development of specific SPCs. © 2016 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

Spectroscopy of 70Kr and isospin symmetry in the T =1 f p g shell nuclei

NASA Astrophysics Data System (ADS)

Debenham, D. M.; Bentley, M. A.; Davies, P. J.; Haylett, T.; Jenkins, D. G.; Joshi, P.; Sinclair, L. F.; Wadsworth, R.; Ruotsalainen, P.; Henderson, J.; Kaneko, K.; Auranen, K.; Badran, H.; Grahn, T.; Greenlees, P.; HerzaáÅ, A.; Jakobsson, U.; Konki, J.; Julin, R.; Juutinen, S.; Leino, M.; Sorri, J.; Pakarinen, J.; Papadakis, P.; Peura, P.; Partanen, J.; Rahkila, P.; Sandzelius, M.; Sarén, J.; Scholey, C.; Stolze, S.; Uusitalo, J.; David, H. M.; de Angelis, G.; Korten, W.; Lotay, G.; Mallaburn, M.; Sahin, E.

2016-11-01

The recoil-β tagging technique has been used in conjunction with the 40Ca(32S,2 n ) reaction at a beam energy of 88 MeV to identify transitions associated with the decay of the 2+ and, tentatively, 4+ states in the nucleus 70Kr. These data are used, along with previously published data, to examine the triplet energy differences (TED) for the mass 70 isobars. The experimental TED values are compared with shell model calculations, performed with the JUN45 interaction in the f p g model space, that include a J =0 isospin nonconserving (INC) interaction with an isotensor strength of 100 keV. The agreement is found to be very good up to spin 4 and supports the expectation for analog states that all three nuclei have the same oblate shape at low-spin. The A =70 results are compared with the experimental and shell model predicted TED and mirror energy differences (MED) for the mass 66 and 74 systems. The comparisons clearly demonstrate the importance of the isotensor INC interaction in replicating the TED data in this region. Issues related to the observed MED values and their interpretation within the shell model are discussed.

Evaluating statistical and clinical significance of intervention effects in single-case experimental designs: an SPSS method to analyze univariate data.

PubMed

Maric, Marija; de Haan, Else; Hogendoorn, Sanne M; Wolters, Lidewij H; Huizenga, Hilde M

2015-03-01

Single-case experimental designs are useful methods in clinical research practice to investigate individual client progress. Their proliferation might have been hampered by methodological challenges such as the difficulty applying existing statistical procedures. In this article, we describe a data-analytic method to analyze univariate (i.e., one symptom) single-case data using the common package SPSS. This method can help the clinical researcher to investigate whether an intervention works as compared with a baseline period or another intervention type, and to determine whether symptom improvement is clinically significant. First, we describe the statistical method in a conceptual way and show how it can be implemented in SPSS. Simulation studies were performed to determine the number of observation points required per intervention phase. Second, to illustrate this method and its implications, we present a case study of an adolescent with anxiety disorders treated with cognitive-behavioral therapy techniques in an outpatient psychotherapy clinic, whose symptoms were regularly assessed before each session. We provide a description of the data analyses and results of this case study. Finally, we discuss the advantages and shortcomings of the proposed method. Copyright © 2014. Published by Elsevier Ltd.

"A hard day's night?" The effects of Compressed Working Week interventions on the health and work-life balance of shift workers: a systematic review.

PubMed

Bambra, C; Whitehead, M; Sowden, A; Akers, J; Petticrew, M

2008-09-01

To systematically review studies of the effects of the Compressed Working Week on the health and work-life balance of shift workers, and to identify any differential impacts by socio-economic group. Systematic review. Following QUORUM guidelines, published or unpublished experimental and quasi-experimental studies were identified. Data were sourced from 27 electronic databases, websites, bibliographies, and expert contacts. Fourty observational studies were found. The majority of studies only measured self-reported outcomes and the methodological quality of the included studies was not very high. Interventions did not always improve the health of shift workers, but in the five prospective studies with a control group, there were no detrimental effects on self-reported health. However, work-life balance was generally improved. No studies reported differential impacts by socio-economic group; however, most of the studies were conducted on homogeneous populations. This review suggests that the Compressed Working Week can improve work-life balance, and that it may do so with a low risk of adverse health or organisational effects. However, better designed studies that measure objective health outcomes are needed.

Phenotypic stability and plasticity in GMP-derived cells as determined by their underlying regulatory network.

PubMed

Ramírez, Carlos; Mendoza, Luis

2018-04-01

Blood cell formation has been recognized as a suitable system to study celular differentiation mainly because of its experimental accessibility, and because it shows characteristics such as hierarchical and gradual bifurcated patterns of commitment, which are present in several developmental processes. Although hematopoiesis has been extensively studied and there is a wealth of molecular and cellular data about it, it is not clear how the underlying molecular regulatory networks define or restrict cellular differentiation processes. Here, we infer the molecular regulatory network that controls the differentiation of a blood cell subpopulation derived from the granulocyte-monocyte precursor (GMP), comprising monocytes, neutrophils, eosinophils, basophils and mast cells. We integrate published qualitative experimental data into a model to describe temporal expression patterns observed in GMP-derived cells. The model is implemented as a Boolean network, and its dynamical behavior is studied. Steady states of the network can be clearly identified with the expression profiles of monocytes, mast cells, neutrophils, basophils, and eosinophils, under wild-type and mutant backgrounds. All scripts are publicly available at https://github.com/caramirezal/RegulatoryNetworkGMPModel. lmendoza@biomedicas.unam.mx. Supplementary data are available at Bioinformatics online.

Nanoparticles in Medicine: Selected Observations and Experimental Caveats.

PubMed

Thomsen, Sharon; Pearce, John A; Giustini, Andrew; Hoopes, P Jack

2013-02-26

Medically useful nanoparticles measure 1-100 nm in at least one dimension and are engineered and manufactured for specific diagnostic and treatment applications. Most nanoparticles used currently used in medicine are engineered and manufactured for specific purposes. Medically significant nanoparticles are composed of a 1) central core that is usually the medically active component, 2) one or more layers of organic or inorganic materials that forms a capsule (corona) covering the core and 3) an outer surface layer that interacts with the environment and/or targeted cells and tissues. Effective nanoparticle function in the living, intact animal or human requires electrochemical stability necessary to bypass the reticuloendothelial system (RES) and avoid filtration through the renal glomerulus into the urine. Nanoparticles are present in "natural" as well as the manufacturing and clinical environments thus could pose as significant toxins because of their small sizes, their chemical and drug content and potential effect of causing long term disease including allergies, chronic inflammation and cancer. Currently published studies have focused on the effects of nanoparticles on cells in the extremely artificial environments of cell cultures. More clinical and preclinical studies documenting the short term and long term effects nanoparticle in the intact experimental animal and human are needed.

Effect of a mind-body therapeutic program for infertile women repeating in vitro fertilization treatment on uncertainty, anxiety, and implantation rate.

PubMed

Kim, Miok; Kim, Sue; Chang, Soon-bok; Yoo, Ji-Soo; Kim, Hee Kyung; Cho, Jung Hyun

2014-03-01

The study aimed to develop a mind-body therapeutic program and evaluate its effects on mitigating uncertainty, anxiety, and implantation rate of second-trial in vitro fertilization (IVF) women. This study employed a nonequivalent control group nonsynchronized design. The conceptual framework and program content were developed from a preliminary survey of eight infertile women and the extensive review of the literature. Program focuses on three uncertainty-induced anxieties in infertile women: cognitive, emotional, and biological responses. To evaluate the effect of the intervention, the infertile women with unknown cause preparing for a second IVF treatment were sampled at convenience (26 experimental and 24 control). The experimental group in the study showed greater decrease in uncertainty and anxiety in premeasurements and postmeasurements than the control group did. However, no statistically significant differences in the implantation rate between groups were observed. This study is meaningful as the first intervention program for alleviating uncertainty and anxiety provided during the IVF treatment process. The positive effects of the mind-body therapeutic program in alleviating both uncertainty and anxiety have direct meaning for clinical applications. Copyright © 2014. Published by Elsevier B.V.

Nanoparticles in medicine: selected observations and experimental caveats

NASA Astrophysics Data System (ADS)

Thomsen, Sharon; Pearce, John A.; Giustini, Andrew; Hoopes, P. Jack

2013-02-01

Medically useful nanoparticles measure 1-100 nm in at least one dimension and are engineered and manufactured for specific diagnostic and treatment applications. Most nanoparticles used currently used in medicine are engineered and manufactured for specific purposes. Medically significant nanoparticles are composed of a 1) central core that is usually the medically active component, 2) one or more layers of organic or inorganic materials that forms a capsule (corona) covering the core and 3) an outer surface layer that interacts with the environment and/or targeted cells and tissues. Effective nanoparticle function in the living, intact animal or human requires electrochemical stability necessary to bypass the reticuloendothelial system (RES) and avoid filtration through the renal glomerulus into the urine. Nanoparticles are present in " natural" as well as the manufacturing and clinical environments thus could pose as significant toxins because of their small sizes, their chemical and drug content and potential effect of causing long term disease including allergies, chronic inflammation and cancer. Currently published studies have focused on the effects of nanoparticles on cells in the extremely artificial environments of cell cultures. More clinical and preclinical studies documenting the short term and long term effects nanoparticle in the intact experimental animal and human are needed.

[Disinfecting contact tonometers - a systematic review].

PubMed

Neubauer, A S; Heeg, P; Kampik, A; Hirneiss, C

2009-05-01

The aim of this study is to provide the best available evidence on how to disinfect contact Goldman tonometers. A systematic review of all articles on disinfection of contact tonometers was conducted. Articles published up to July 2008 were identified in Medline, Embase and references from included articles. Two observers participated in the data retrieval and assessment of the studies identified. A total of 89 articles was retrieved, of which 58 could be included. Of those, 18 were clinical studies, 17 experimental microbiological studies, 8 expert assessments or guidelines and 15 reviews, surveys, descriptions of new methods. The clinical studies illustrate the importance of the problem, possible side effects of some disinfection methods but yield inconclusive results regarding efficacy. Experimental studies investigated a variety of bacterial and virological questions as well as material damage by disinfection. Both chlorine-based and hydrogen peroxide-based liquid disinfection were shown to be effective if applied for 5 min. Inconsistent results exist for alcohol wipes and UV disinfection - material damage has been described for both. The US guidelines and most expert recommendations are supported by evidence of the existing data. Chlorine-based and hydrogen peroxide-based liquid disinfections for 5 minutes are effective and relatively safe for disinfecting contact tonometers.

Modeling tuberculosis pathogenesis through ex vivo lung tissue infection.

PubMed

Carranza-Rosales, Pilar; Carranza-Torres, Irma Edith; Guzmán-Delgado, Nancy Elena; Lozano-Garza, Gerardo; Villarreal-Treviño, Licet; Molina-Torres, Carmen; Villarreal, Javier Vargas; Vera-Cabrera, Lucio; Castro-Garza, Jorge

2017-12-01

Tuberculosis (TB) is one of the top 10 causes of death worldwide. Several in vitro and in vivo experimental models have been used to study TB pathogenesis and induction of immune response during Mycobacterium tuberculosis infection. Precision cut lung tissue slices (PCLTS) is an experimental model, in which all the usual cell types of the organ are found, the tissue architecture and the interactions amongst the different cells are maintained. PCLTS in good physiological conditions, monitored by MTT assay and histology, were infected with either virulent Mycobacterium tuberculosis strain H37Rv or the TB vaccine strain Mycobacterium bovis BCG. Histological analysis showed that bacilli infecting lung tissue slices were observed in the alveolar septa, alveolar light spaces, near to type II pneumocytes, and inside macrophages. Mycobacterial infection of PCLTS induced TNF-α production, which is consistent with previous M. tuberculosis in vitro and in vivo studies. This is the first report of using PCLTS as a system to study M. tuberculosis infection. The PCLTS model provides a useful tool to evaluate the innate immune responses and other aspects during the early stages of mycobacterial infection. Copyright © 2017. Published by Elsevier Ltd.

Thermal conduction mechanisms in isotope-disordered boron nitride and carbon nanotubes

NASA Astrophysics Data System (ADS)

Savic, Ivana; Mingo, Natalio; Stewart, Derek

2009-03-01

We present first principles studies which determine dominant effects limiting the heat conduction in isotope-disordered boron nitride and carbon nanotubes [1]. Using an ab initio atomistic Green's function approach, we demonstrate that localization cannot be observed in the thermal conductivity measurements [1], and that diffusive scattering is the dominant mechanism which reduces the thermal conductivity [2]. We also give concrete predictions of the magnitude of the isotope effect on the thermal conductivities of carbon and boron nitride single-walled nanotubes [2]. We furthermore show that intershell scattering is not the main limiting mechanism for the heat flow through multi-walled boron nitride nanotubes [1], and that heat conduction restricted to a few shells leads to the low thermal conductivities experimentally measured [1]. We consequently successfully compare the results of our calculations [3] with the experimental measurements [1]. [1] C. W. Chang, A. M. Fennimore, A. Afanasiev, D. Okawa, T. Ikuno, H. Garcia, D. Li, A. Majumdar, A. Zettl, Phys. Rev. Lett. 2006, 97, 085901. [2] I. Savic, N. Mingo, D. A. Stewart, Phys. Rev. Lett. 2008, 101, 165502. [3] I. Savic, D. A. Stewart, N. Mingo, to be published.

Morphogen-based simulation model of ray growth and joint patterning during fin development and regeneration.

PubMed

Rolland-Lagan, Anne-Gaëlle; Paquette, Mathieu; Tweedle, Valerie; Akimenko, Marie-Andrée

2012-03-01

The fact that some organisms are able to regenerate organs of the correct shape and size following amputation is particularly fascinating, but the mechanism by which this occurs remains poorly understood. The zebrafish (Danio rerio) caudal fin has emerged as a model system for the study of bone development and regeneration. The fin comprises 16 to 18 bony rays, each containing multiple joints along its proximodistal axis that give rise to segments. Experimental observations on fin ray growth, regeneration and joint formation have been described, but no unified theory has yet been put forward to explain how growth and joint patterns are controlled. We present a model for the control of fin ray growth during development and regeneration, integrated with a model for joint pattern formation, which is in agreement with published, as well as new, experimental data. We propose that fin ray growth and joint patterning are coordinated through the interaction of three morphogens. When the model is extended to incorporate multiple rays across the fin, it also accounts for how the caudal fin acquires its shape during development, and regains its correct size and shape following amputation.

A temporal model of cofilin regulation and the early peak of actin barbed ends in invasive tumor cells.

PubMed

Tania, Nessy; Prosk, Erin; Condeelis, John; Edelstein-Keshet, Leah

2011-04-20

Cofilin is an important regulator of actin polymerization, cell migration, and chemotaxis. Recent experimental data on mammary carcinoma cells reveal that stimulation by epidermal growth factor (EGF) generates a pool of active cofilin that results in a peak of actin filament barbed ends on the timescale of 1 min. Here, we present results of a mathematical model for the dynamics of cofilin and its transition between several pools in response to EGF stimulation. We describe the interactions of phospholipase C, membrane lipids (PIP(2)), and cofilin bound to PIP(2) and to F-actin, as well as diffusible cofilin in active G-actin-monomer-bound or phosphorylated states. We consider a simplified representation in which the thin cell edge (lamellipod) and the cell interior are represented by two compartments that are linked by diffusion. We demonstrate that a high basal level of active cofilin stored by binding to PIP(2), as well as the highly enriched local milieu of F-actin at the cell edge, is essential to capture the EGF-induced barbed-end amplification observed experimentally. Copyright © 2011 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Studying the neurobiology of human social interaction: Making the case for ecological validity.

PubMed

Hogenelst, Koen; Schoevers, Robert A; aan het Rot, Marije

2015-01-01

With this commentary we make the case for an increased focus on the ecological validity of the measures used to assess aspects of human social functioning. Impairments in social functioning are seen in many types of psychopathology, negatively affecting the lives of psychiatric patients and those around them. Yet the neurobiology underlying abnormal social interaction remains unclear. As an example of human social neuroscience research with relevance to biological psychiatry and clinical psychopharmacology, this commentary discusses published experimental studies involving manipulation of the human brain serotonin system that included assessments of social behavior. To date, these studies have mostly been laboratory-based and included computer tasks, observations by others, or single-administration self-report measures. Most laboratory measures used so far inform about the role of serotonin in aspects of social interaction, but the relevance for real-life interaction is often unclear. Few studies have used naturalistic assessments in real life. We suggest several laboratory methods with high ecological validity as well as ecological momentary assessment, which involves intensive repeated measures in naturalistic settings. In sum, this commentary intends to stimulate experimental research on the neurobiology of human social interaction as it occurs in real life.

Experimental febrile seizures induce age-dependent structural plasticity and improve memory in mice.

PubMed

Tao, K; Ichikawa, J; Matsuki, N; Ikegaya, Y; Koyama, R

2016-03-24

Population-based studies have demonstrated that children with a history of febrile seizure (FS) perform better than age-matched controls at hippocampus-dependent memory tasks. Here, we report that FSs induce two distinct structural reorganizations in the hippocampus and bidirectionally modify future learning abilities in an age-dependent manner. Compared with age-matched controls, adult mice that had experienced experimental FSs induced by hyperthermia (HT) on postnatal day 14 (P14-HT) performed better in a cognitive task that requires dentate granule cells (DGCs). The enhanced memory performance correlated with an FS-induced persistent increase in the density of large mossy fiber terminals (LMTs) of the DGCs. The memory enhancement was not observed in mice that had experienced HT-induced seizures at P11 which exhibited abnormally located DGCs in addition to the increased LMT density. The ectopic DGCs of the P11-HT mice were abolished by the diuretic bumetanide, and this pharmacological treatment unveiled the masked memory enhancement. Thus, this work provides a novel basis for age-dependent structural plasticity in which FSs influence future brain function. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

Conformational Spread in the Flagellar Motor Switch: A Model Study

PubMed Central

Maini, Philip K.; Berry, Richard M.; Bai, Fan

2012-01-01

The reliable response to weak biological signals requires that they be amplified with fidelity. In E. coli, the flagellar motors that control swimming can switch direction in response to very small changes in the concentration of the signaling protein CheY-P, but how this works is not well understood. A recently proposed allosteric model based on cooperative conformational spread in a ring of identical protomers seems promising as it is able to qualitatively reproduce switching, locked state behavior and Hill coefficient values measured for the rotary motor. In this paper we undertook a comprehensive simulation study to analyze the behavior of this model in detail and made predictions on three experimentally observable quantities: switch time distribution, locked state interval distribution, Hill coefficient of the switch response. We parameterized the model using experimental measurements, finding excellent agreement with published data on motor behavior. Analysis of the simulated switching dynamics revealed a mechanism for chemotactic ultrasensitivity, in which cooperativity is indispensable for realizing both coherent switching and effective amplification. These results showed how cells can combine elements of analog and digital control to produce switches that are simultaneously sensitive and reliable. PMID:22654654

Measured and Monte Carlo calculated k{sub Q} factors: Accuracy and comparison

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

Muir, B. R.; McEwen, M. R.; Rogers, D. W. O.

2011-08-15

Purpose: The journal Medical Physics recently published two papers that determine beam quality conversion factors, k{sub Q}, for large sets of ion chambers. In the first paper [McEwen Med. Phys. 37, 2179-2193 (2010)], k{sub Q} was determined experimentally, while the second paper [Muir and Rogers Med. Phys. 37, 5939-5950 (2010)] provides k{sub Q} factors calculated using Monte Carlo simulations. This work investigates a variety of additional consistency checks to verify the accuracy of the k{sub Q} factors determined in each publication and a comparison of the two data sets. Uncertainty introduced in calculated k{sub Q} factors by possible variation ofmore » W/e with beam energy is investigated further. Methods: The validity of the experimental set of k{sub Q} factors relies on the accuracy of the NE2571 reference chamber measurements to which k{sub Q} factors for all other ion chambers are correlated. The stability of NE2571 absorbed dose to water calibration coefficients is determined and comparison to other experimental k{sub Q} factors is analyzed. Reliability of Monte Carlo calculated k{sub Q} factors is assessed through comparison to other publications that provide Monte Carlo calculations of k{sub Q} as well as an analysis of the sleeve effect, the effect of cavity length and self-consistencies between graphite-walled Farmer-chambers. Comparison between the two data sets is given in terms of the percent difference between the k{sub Q} factors presented in both publications. Results: Monitoring of the absorbed dose calibration coefficients for the NE2571 chambers over a period of more than 15 yrs exhibit consistency at a level better than 0.1%. Agreement of the NE2571 k{sub Q} factors with a quadratic fit to all other experimental data from standards labs for the same chamber is observed within 0.3%. Monte Carlo calculated k{sub Q} factors are in good agreement with most other Monte Carlo calculated k{sub Q} factors. Expected results are observed for the sleeve effect and the effect of cavity length on k{sub Q}. The mean percent differences between experimental and Monte Carlo calculated k{sub Q} factors are -0.08, -0.07, and -0.23% for the Elekta 6, 10, and 25 MV nominal beam energies, respectively. An upper limit on the variation of W/e in photon beams from cobalt-60 to 25 MV is determined as 0.4% with 95% confidence. The combined uncertainty on Monte Carlo calculated k{sub Q} factors is reassessed and amounts to between 0.40 and 0.49% depending on the wall material of the chamber. Conclusions: Excellent agreement (mean percent difference of only 0.13% for the entire data set) between experimental and calculated k{sub Q} factors is observed. For some chambers, k{sub Q} is measured for only one chamber of each type--the level of agreement observed in this study would suggest that for those chambers the measured k{sub Q} values are generally representative of the chamber type.« less

Stability analysis of shallow wake flows

NASA Astrophysics Data System (ADS)

Kolyshkin, A. A.; Ghidaoui, M. S.

2003-11-01

Experimentally observed periodic structures in shallow (i.e. bounded) wake flows are believed to appear as a result of hydrodynamic instability. Previously published studies used linear stability analysis under the rigid-lid assumption to investigate the onset of instability of wakes in shallow water flows. The objectives of this paper are: (i) to provide a preliminary assessment of the accuracy of the rigid-lid assumption; (ii) to investigate the influence of the shape of the base flow profile on the stability characteristics; (iii) to formulate the weakly nonlinear stability problem for shallow wake flows and show that the evolution of the instability is governed by the Ginzburg Landau equation; and (iv) to establish the connection between weakly nonlinear analysis and the observed flow patterns in shallow wake flows which are reported in the literature. It is found that the relative error in determining the critical value of the shallow wake stability parameter induced by the rigid-lid assumption is below 10% for the practical range of Froude number. In addition, it is shown that the shape of the velocity profile has a large influence on the stability characteristics of shallow wakes. Starting from the rigid-lid shallow-water equations and using the method of multiple scales, an amplitude evolution equation for the most unstable mode is derived. The resulting equation has complex coefficients and is of Ginzburg Landau type. An example calculation of the complex coefficients of the Ginzburg Landau equation confirms the existence of a finite equilibrium amplitude, where the unstable mode evolves with time into a limit-cycle oscillation. This is consistent with flow patterns observed by Ingram & Chu (1987), Chen & Jirka (1995), Balachandar et al. (1999), and Balachandar & Tachie (2001). Reasonable agreement is found between the saturation amplitude obtained from the Ginzburg Landau equation under some simplifying assumptions and the numerical data of Grubi[sbreve]ic et al. (1995). Such consistency provides further evidence that experimentally observed structures in shallow wake flows may be described by the nonlinear Ginzburg Landau equation. Previous works have found similar consistency between the Ginzburg Landau model and experimental data for the case of deep (i.e. unbounded) wake flows. However, it must be emphasized that much more information is required to confirm the appropriateness of the Ginzburg Landau equation in describing shallow wake flows.

Osseointegration in osteoporotic-like condition: A systematic review of preclinical studies.

PubMed

Dereka, X; Calciolari, E; Donos, N; Mardas, N

2018-05-30

Osteoporosis is one of the most common skeletal disorders affecting a significant percentage of people worldwide. Research data suggested that systemic diseases such as osteoporosis could act as risk factors for osseointegration, jeopardizing the healing process and thus the predictability of dental implant success on compromised patients. It is well accepted that preclinical studies in animal models reproducing the osteoporotic condition are one of the most important stages in the research of new biomaterials and therapeutic modalities. The aim of this systematic review was to investigate whether osteoporosis compromises dental implant osseointegration in experimental osteoporotic-like conditions. A 3-stage systematic literature research was conducted in MEDLINE via OVID and EMBASE up to and including March 2017. Experimental studies reporting on dental implant osseointegration on different osteoporotic animal models were assessed. The studies had to report on the percentage of bone-to-implant contact (%BIC) as the primary outcome. ARRIVE guidelines for reporting on animal research were applied to evaluate the methodological quality and risk of bias of the studies. Fifty-seven studies met the inclusion criteria and were assessed qualitatively. The most adopted animal model was the rat. A variability of %BIC values was observed, ranging from 30% to 99% and from 26% to 94% for the healthy and osteoporotic group, respectively. The great majority (47) of the included studies concluded that estrogen deficiency significantly affects BIC values, 9 studies stated that it was not possible to observe statistical differences in BIC between ovariectomized and healthy groups and 1 study did not provide a comparison between the healthy and osteoporotic group. Owing to the great heterogeneity in implant surface, study design, observation time-points, site of implant placement and reported outcomes, a meta-analysis could not be performed. An overall high risk of bias was observed, owing to the limited information on animal housing and husbandry, baseline characteristics and health status, ethical statement and allocation to the experimental groups provided. Although the available studies seem to suggest a lower osseointegration in osteoporotic-like conditions, no robust conclusions can be drawn due to the great heterogeneity and overall low quality of the available studies. Future studies with emphasis on minimizing the possible sources of bias and evaluating osseointegration of dental implants placed into jawbones instead of long bones are warranted. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

miRwayDB: a database for experimentally validated microRNA-pathway associations in pathophysiological conditions

PubMed Central

Das, Sankha Subhra; Saha, Pritam

2018-01-01

Abstract MicroRNAs (miRNAs) are well-known as key regulators of diverse biological pathways. A series of experimental evidences have shown that abnormal miRNA expression profiles are responsible for various pathophysiological conditions by modulating genes in disease associated pathways. In spite of the rapid increase in research data confirming such associations, scientists still do not have access to a consolidated database offering these miRNA-pathway association details for critical diseases. We have developed miRwayDB, a database providing comprehensive information of experimentally validated miRNA-pathway associations in various pathophysiological conditions utilizing data collected from published literature. To the best of our knowledge, it is the first database that provides information about experimentally validated miRNA mediated pathway dysregulation as seen specifically in critical human diseases and hence indicative of a cause-and-effect relationship in most cases. The current version of miRwayDB collects an exhaustive list of miRNA-pathway association entries for 76 critical disease conditions by reviewing 663 published articles. Each database entry contains complete information on the name of the pathophysiological condition, associated miRNA(s), experimental sample type(s), regulation pattern (up/down) of miRNA, pathway association(s), targeted member of dysregulated pathway(s) and a brief description. In addition, miRwayDB provides miRNA, gene and pathway score to evaluate the role of a miRNA regulated pathways in various pathophysiological conditions. The database can also be used for other biomedical approaches such as validation of computational analysis, integrated analysis and prediction of computational model. It also offers a submission page to submit novel data from recently published studies. We believe that miRwayDB will be a useful tool for miRNA research community. Database URL: http://www.mirway.iitkgp.ac.in PMID:29688364

A permeation theory for single-file ion channels: one- and two-step models.

PubMed

Nelson, Peter Hugo

2011-04-28

How many steps are required to model permeation through ion channels? This question is investigated by comparing one- and two-step models of permeation with experiment and MD simulation for the first time. In recent MD simulations, the observed permeation mechanism was identified as resembling a Hodgkin and Keynes knock-on mechanism with one voltage-dependent rate-determining step [Jensen et al., PNAS 107, 5833 (2010)]. These previously published simulation data are fitted to a one-step knock-on model that successfully explains the highly non-Ohmic current-voltage curve observed in the simulation. However, these predictions (and the simulations upon which they are based) are not representative of real channel behavior, which is typically Ohmic at low voltages. A two-step association/dissociation (A/D) model is then compared with experiment for the first time. This two-parameter model is shown to be remarkably consistent with previously published permeation experiments through the MaxiK potassium channel over a wide range of concentrations and positive voltages. The A/D model also provides a first-order explanation of permeation through the Shaker potassium channel, but it does not explain the asymmetry observed experimentally. To address this, a new asymmetric variant of the A/D model is developed using the present theoretical framework. It includes a third parameter that represents the value of the "permeation coordinate" (fractional electric potential energy) corresponding to the triply occupied state n of the channel. This asymmetric A/D model is fitted to published permeation data through the Shaker potassium channel at physiological concentrations, and it successfully predicts qualitative changes in the negative current-voltage data (including a transition to super-Ohmic behavior) based solely on a fit to positive-voltage data (that appear linear). The A/D model appears to be qualitatively consistent with a large group of published MD simulations, but no quantitative comparison has yet been made. The A/D model makes a network of predictions for how the elementary steps and the channel occupancy vary with both concentration and voltage. In addition, the proposed theoretical framework suggests a new way of plotting the energetics of the simulated system using a one-dimensional permeation coordinate that uses electric potential energy as a metric for the net fractional progress through the permeation mechanism. This approach has the potential to provide a quantitative connection between atomistic simulations and permeation experiments for the first time.

The Experimental Social Scientific Model in Speech Communication Research: Influences and Consequences.

ERIC Educational Resources Information Center

Ferris, Sharmila Pixy

A substantial number of published articles in speech communication research today is experimental/social scientific in nature. It is only in the past decade that scholars have begun to put the history of communication under the lens. Early advocates of the adoption of the method of social scientific inquiry were J. A. Winans, J. M. O'Neill, and C.…

Updated database for K-shell fluorescence yields

NASA Astrophysics Data System (ADS)

Akdemir, Fatma; Araz, Aslı; Akman, Ferdi; Kaçal, Mustafa Recep; Durak, Rıdvan

2017-04-01

This study presents a summary of experimental data of K-shell fluorescence yields (ωK) published in the period of time between 2010 to february-2017. The fluorescence yields (ωK) of elements in the range 23≤Z≤60 taken directly from different sources were reviewed and presented in a table form. Finally, the experimental and empirical values in the literature have been reported and commented.

New Media for Instruction: Survey of Educational Media Research in the Far East. Instructional Uses and Research Direction. Bulletin, 1963, No. 40. OE-34025

ERIC Educational Resources Information Center

Duke, Benjamin C., Ed.

1963-01-01

The primary purpose of this project was to compile, translate, and publish educational media research material from the major Asian countries and to make that information available in the United States. Educational media research and experimentation is interpreted to include experimental programming, testing, evaluation, and use of all the newer…

What We Have Learned About the Existing Trace Element Partitioning data During the Population Phase of traceDs

NASA Astrophysics Data System (ADS)

Nielsen, R. L.; Ghiorso, M. S.; Trischman, T.

2015-12-01

The database traceDs is designed to provide a transparent and accessible resource of experimental partitioning data. It now includes ~ 90% of all the experimental trace element partitioning data (~4000 experiments) produced over the past 45 years, and is accessible through a web based interface (using the portal lepr.ofm-research.org). We set a minimum standard for inclusion, with the threshold criteria being the inclusion of: Experimental conditions (temperature, pressure, device, container, time, etc.) Major element composition of the phases Trace element analyses of the phases Data sources that did not report these minimum components were not included. The rationale for not including such data is that the degree of equilibration is unknown, and more important, no rigorous approach to modeling the behavior of trace elements is possible without knowledge of composition of the phases, and the temperature and pressure of formation/equilibration. The data are stored using a schema derived from that of the Library of Experimental Phase Relations (LEPR), modified to account for additional metadata, and restructured to permit multiple analytical entries for various element/technique/standard combinations. In the process of populating the database, we have learned a number of things about the existing published experimental partitioning data. Most important are: ~ 20% of the papers do not satisfy one or more of the threshold criteria. The standard format for presenting data is the average. This was developed as the standard during the time where there were space constraints for publication in spite of fact that all the information can now be published as electronic supplements. The uncertainties that are published with the compositional data are often not adequately explained (e.g. 1 or 2 sigma, standard deviation of the average, etc.). We propose a new set of publication standards for experimental data that include the minimum criteria described above, the publication of all analyses with error based on peak count rates and background, plus information on the structural state of the mineral (e.g. orthopyroxene vs. pigeonite).

Witnessing entanglement without entanglement witness operators

PubMed Central

Pezzè, Luca; Li, Yan; Li, Weidong; Smerzi, Augusto

2016-01-01

Quantum mechanics predicts the existence of correlations between composite systems that, although puzzling to our physical intuition, enable technologies not accessible in a classical world. Notwithstanding, there is still no efficient general method to theoretically quantify and experimentally detect entanglement of many qubits. Here we propose to detect entanglement by measuring the statistical response of a quantum system to an arbitrary nonlocal parametric evolution. We witness entanglement without relying on the tomographic reconstruction of the quantum state, or the realization of witness operators. The protocol requires two collective settings for any number of parties and is robust against noise and decoherence occurring after the implementation of the parametric transformation. To illustrate its user friendliness we demonstrate multipartite entanglement in different experiments with ions and photons by analyzing published data on fidelity visibilities and variances of collective observables. PMID:27681625

High precision tracking control of a servo gantry with dynamic friction compensation.

PubMed

Zhang, Yangming; Yan, Peng; Zhang, Zhen

2016-05-01

This paper is concerned with the tracking control problem of a voice coil motor (VCM) actuated servo gantry system. By utilizing an adaptive control technique combined with a sliding mode approach, an adaptive sliding mode control (ASMC) law with friction compensation scheme is proposed in presence of both frictions and external disturbances. Based on the LuGre dynamic friction model, a dual-observer structure is used to estimate the unmeasurable friction state, and an adaptive control law is synthesized to effectively handle the unknown friction model parameters as well as the bound of the disturbances. Moreover, the proposed control law is also implemented on a VCM servo gantry system for motion tracking. Simulations and experimental results demonstrate good tracking performance, which outperform traditional control approaches. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

Vitamin D and asthma.

PubMed

Paul, Grace; Brehm, John M; Alcorn, John F; Holguín, Fernando; Aujla, Shean J; Celedón, Juan C

2012-01-15

Vitamin D deficiency and asthma are common conditions that share risk factors such as African American ethnicity, inner-city residence, and obesity. This review provides a critical examination of current experimental and epidemiologic evidence of a causal association between vitamin D status and asthma or asthma morbidity, including potential protective mechanisms such as antiviral effects and enhanced steroid responsiveness. Because most published epidemiologic studies of vitamin D and asthma or asthma morbidity are observational, a recommendation for or against vitamin D supplementation as preventive or secondary treatment for asthma is not advisable and must await results of ongoing clinical trials. Should these trials confirm a beneficial effect of vitamin D, others will be needed to assess the role of vitamin D supplementation to prevent or treat asthma in different groups such as infants, children of school age, and ethnic minorities.

Vitamin D and Asthma

PubMed Central

Paul, Grace; Brehm, John M.; Alcorn, John F.; Holguín, Fernando; Aujla, Shean J.

2012-01-01

Vitamin D deficiency and asthma are common conditions that share risk factors such as African American ethnicity, inner-city residence, and obesity. This review provides a critical examination of current experimental and epidemiologic evidence of a causal association between vitamin D status and asthma or asthma morbidity, including potential protective mechanisms such as antiviral effects and enhanced steroid responsiveness. Because most published epidemiologic studies of vitamin D and asthma or asthma morbidity are observational, a recommendation for or against vitamin D supplementation as preventive or secondary treatment for asthma is not advisable and must await results of ongoing clinical trials. Should these trials confirm a beneficial effect of vitamin D, others will be needed to assess the role of vitamin D supplementation to prevent or treat asthma in different groups such as infants, children of school age, and ethnic minorities. PMID:22016447

Solvent dependent frequency shift and Raman noncoincidence effect of S=O stretching mode of Dimethyl sulfoxide in liquid binary mixtures.

PubMed

Upadhyay, Ganesh; Devi, Th Gomti; Singh, Ranjan K; Singh, A; Alapati, P R

2013-05-15

The isotropic and anisotropic Raman peak frequencies of S=O stretching mode of Dimethyl sulfoxide (DMSO) have been discussed in different chemical and isotopic solvent molecules using different mechanisms. The shifting of peak frequency in further dilution of DMSO with solvent molecule is observed for all solvents. Transition dipole - transition dipole interaction and hydrogen bonding may play a major role in shifting of peak frequencies. The non-coincidence effect (NCE) of DMSO was determined for all the solvents and compared with four theoretical models such as McHale's model, Mirone's modification of McHale's model, Logan's model and Onsager-Fröhlich dielectric continuum model respectively. Most of the theoretical models are largely consistent with our experimental data. Copyright © 2013. Published by Elsevier B.V.

Sensor fault detection and isolation system for a condensation process.

PubMed

Castro, M A López; Escobar, R F; Torres, L; Aguilar, J F Gómez; Hernández, J A; Olivares-Peregrino, V H

2016-11-01

This article presents the design of a sensor Fault Detection and Isolation (FDI) system for a condensation process based on a nonlinear model. The condenser is modeled by dynamic and thermodynamic equations. For this work, the dynamic equations are described by three pairs of differential equations which represent the energy balance between the fluids. The thermodynamic equations consist in algebraic heat transfer equations and empirical equations, that allow for the estimation of heat transfer coefficients. The FDI system consists of a bank of two nonlinear high-gain observers, in order to detect, estimate and to isolate the fault in any of both outlet temperature sensors. The main contributions of this work were the experimental validation of the condenser nonlinear model and the FDI system. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

New concept to describe three-phase capillary pressure-degree of saturation relationship in porous media.

PubMed

Nakamura, Keita; Kikumoto, Mamoru

2018-07-01

The Leverett concept is used conventionally to model the relationship between the capillary pressures and the degrees of saturation in the water-nonaqueous phase liquid (NAPL)-air three-phase system in porous media. In this paper, the limitation of the Leverett concept that the concept is not applicable in the case of nonspreading NAPLs is discussed through microscopic consideration. A new concept that can be applied in the case of nonspreading NAPLs as well as spreading NAPLs is then proposed. The validity of the proposed concept is confirmed by comparing with past experimental data and simulation results obtained using the conventional model based on the Leverett concept. It is confirmed that the proposed concept can correctly predict the observed distributions of NAPLs, including those of nonspreading ones. Copyright © 2018. Published by Elsevier B.V.

Mix-breeding with HEV-infected swine induced inapparent HEV infection in SPF rabbits.

PubMed

Liu, Lin; Wang, Lin; Xia, Junke; Zhang, Yulin; Zeng, Hang; Liu, Peng; Zou, Qinghua; Wang, Ling; Zhuang, Hui

2016-04-01

Studies have shown that swine HEV (sHEV) and rabbit HEV (rHEV) can experimentally infect rabbits and swine, respectively. However, no published data have documented isolating sHEV strains from rabbits in natural environment so far. To clarify the possibility of natural cross-species transmission of sHEV to rabbits, the pigs with HEV infection were farmed along with SPF rabbits in the same enclosed space. Five of 10 rabbits had seroconversion for anti-HEV antibody from the third week after mix-breeding. However, HEV RNA remained undetectable in feces, serum, liver and bile of the ten rabbits; and no obvious elevation of ALT was observed. The results possibly suggested that sHEV might lead to an inapparent infection of SPF rabbits by fecal-oral route. © 2015 Wiley Periodicals, Inc.

Atom chips in the real world: the effects of wire corrugation

NASA Astrophysics Data System (ADS)

Schumm, T.; Estève, J.; Figl, C.; Trebbia, J.-B.; Aussibal, C.; Nguyen, H.; Mailly, D.; Bouchoule, I.; Westbrook, C. I.; Aspect, A.

2005-02-01

We present a detailed model describing the effects of wire corrugation on the trapping potential experienced by a cloud of atoms above a current carrying micro wire. We calculate the distortion of the current distribution due to corrugation and then derive the corresponding roughness in the magnetic field above the wire. Scaling laws are derived for the roughness as a function of height above a ribbon shaped wire. We also present experimental data on micro wire traps using cold atoms which complement some previously published measurements [CITE] and which demonstrate that wire corrugation can satisfactorily explain our observations of atom cloud fragmentation above electroplated gold wires. Finally, we present measurements of the corrugation of new wires fabricated by electron beam lithography and evaporation of gold. These wires appear to be substantially smoother than electroplated wires.

Alignment of cell division axes in directed epithelial cell migration

NASA Astrophysics Data System (ADS)

Marel, Anna-Kristina; Podewitz, Nils; Zorn, Matthias; Oskar Rädler, Joachim; Elgeti, Jens

2014-11-01

Cell division is an essential dynamic event in tissue remodeling during wound healing, cancer and embryogenesis. In collective migration, tensile stresses affect cell shape and polarity, hence, the orientation of the cell division axis is expected to depend on cellular flow patterns. Here, we study the degree of orientation of cell division axes in migrating and resting epithelial cell sheets. We use microstructured channels to create a defined scenario of directed cell invasion and compare this situation to resting but proliferating cell monolayers. In experiments, we find a strong alignment of the axis due to directed flow while resting sheets show very weak global order, but local flow gradients still correlate strongly with the cell division axis. We compare experimental results with a previously published mesoscopic particle based simulation model. Most of the observed effects are reproduced by the simulations.

Taking the lead from our colleagues in medical education: the use of images of the in-vivo setting in teaching concepts of pharmaceutical science.

PubMed

Curley, Louise E; Kennedy, Julia; Hinton, Jordan; Mirjalili, Ali; Svirskis, Darren

2017-01-01

Despite pharmaceutical sciences being a core component of pharmacy curricula, few published studies have focussed on innovative methodologies to teach the content. This commentary identifies imaging techniques which can visualise oral dosage forms in-vivo and observe formulation disintegration in order to achieve a better understanding of in-vivo performance. Images formed through these techniques can provide students with a deeper appreciation of the fate of oral formulations in the body compared to standard disintegration and dissolution testing, which is conducted in-vitro. Such images which represent the in-vivo setting can be used in teaching to give context to both theory and experimental work, thereby increasing student understanding and enabling teaching of pharmaceutical sciences supporting students to correlate in-vitro and in-vivo processes.

[GRADE system: classification of quality of evidence and strength of recommendation].

PubMed

Aguayo-Albasini, José Luis; Flores-Pastor, Benito; Soria-Aledo, Víctor

2014-02-01

The acquisition and classification of scientific evidence, and subsequent formulation of recommendations constitute the basis for the development of clinical practice guidelines. There are several systems for the classification of evidence and strength of recommendations; the most commonly used nowadays is the Grading of Recommendations, Assessment, Development and Evaluation system (GRADE). The GRADE system initially classifies the evidence into high or low, coming from experimental or observational studies; subsequently and following a series of considerations, the evidence is classified into high, moderate, low or very low. The strength of recommendations is based not only on the quality of the evidence, but also on a series of factors such as the risk/benefit balance, values and preferences of the patients and professionals, and the use of resources or costs. Copyright © 2013 AEC. Published by Elsevier Espana. All rights reserved.

A methodological analysis of chaplaincy research: 2000-2009.

PubMed

Galek, Kathleen; Flannelly, Kevin J; Jankowski, Katherine R B; Handzo, George F

2011-01-01

The present article presents a comprehensive review and analysis of quantitative research conducted in the United States on chaplaincy and closely related topics published between 2000 and 2009. A combined search strategy identified 49 quantitative studies in 13 journals. The analysis focuses on the methodological sophistication of the studies, compared to earlier research on chaplaincy and pastoral care. Cross-sectional surveys of convenience samples still dominate the field, but sample sizes have increased somewhat over the past three decades. Reporting of the validity and reliability of measures continues to be low, although reporting of response rates has improved. Improvements in the use of inferential statistics and statistical controls were also observed, compared to previous research. The authors conclude that more experimental research is needed on chaplaincy, along with an increased use of hypothesis testing, regardless of the research designs that are used.

Effectiveness of knowledge translation tools addressing multiple high-burden chronic diseases affecting older adults: protocol for a systematic review alongside a realist review.

PubMed

Kastner, Monika; Perrier, Laure; Hamid, Jemila; Tricco, Andrea C; Cardoso, Roberta; Ivers, Noah M; Liu, Barbara; Marr, Sharon; Holroyd-Leduc, Jayna; Wong, Geoff; Graves, Lisa; Straus, Sharon E

2015-02-03

The burden of chronic disease is a global phenomenon, particularly among people aged 65 years and older. More than half of older adults have more than one chronic disease and their care is not optimal. Chronic disease management (CDM) tools have the potential to meet this challenge but they are primarily focused on a single disease, which fails to address the growing number of seniors with multiple chronic conditions. We will conduct a systematic review alongside a realist review to identify effective CDM tools that integrate one or more high-burden chronic diseases affecting older adults and to better understand for whom, under what circumstances, how and why they produce their outcomes. We will search MEDLINE, EMBASE, CINAHL, AgeLine and the Cochrane Library for experimental, quasi-experimental, observational and qualitative studies in any language investigating CDM tools that facilitate optimal disease management in one or more high-burden chronic diseases affecting adults aged ≥65 years. Study selection will involve calibration of reviewers to ensure reliability of screening and duplicate assessment of articles. Data abstraction and risk of bias assessment will also be performed independently. Analysis will include descriptive summaries of study and appraisal characteristics, effectiveness of each CDM tool (meta-analysis if appropriate); and a realist programme theory will be developed and refined to explain the outcome patterns within the included studies. Ethics approval is not required for this study. We anticipate that our findings, pertaining to gaps in care across high-burden chronic diseases affecting seniors and highlighting specific areas that may require more research, will be of interest to a wide range of knowledge users and stakeholders. We will publish and present our findings widely, and also plan more active dissemination strategies such as workshops with our key stakeholders. Our protocol is registered with PROSPERO (registration number CRD42014014489). Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Dermatophyte-host relationship of a murine model of experimental invasive dermatophytosis.

PubMed

Venturini, James; Alvares, Anuska Marcelino; Camargo, Marcela Rodrigues de; Marchetti, Camila Martins; Fraga-Silva, Thais Fernanda de Campos; Luchini, Ana Carolina; Arruda, Maria Sueli Parreira de

2012-11-01

Recognizing the invasive potential of the dermatophytes and understanding the mechanisms involved in this process will help with disease diagnosis and with developing an appropriate treatment plan. In this report, we present the histopathological, microbiological and immunological features of a model of invasive dermatophytosis that is induced by subcutaneous infection of Trichophyton mentagrophytes in healthy adult Swiss mice. Using this model, we observed that the fungus rapidly spreads to the popliteal lymph nodes, spleen, liver and kidneys. Similar to the human disease, the lymph nodes were the most severely affected sites. The fungal infection evoked acute inflammation followed by a granulomatous reaction in the mice, which is similar to what is observed in patients. The mice were able to mount a Th1-polarized immune response and displayed IL-10-mediated immune regulation. We believe that the model described here will provide valuable information regarding the dermatophyte-host relationship and will yield new perspective for a better understanding of the immunological and pathological aspects of invasive dermatophytosis. Copyright © 2012 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

A compound control strategy combining velocity compensation with ADRC of electro-hydraulic position servo control system.

PubMed

Gao, Bingwei; Shao, Junpeng; Yang, Xiaodong

2014-11-01

In order to enhance the anti-jamming ability of electro-hydraulic position servo control system at the same time improve the control precision of the system, a compound control strategy that combines velocity compensation with Active Disturbance Rejection Controller (ADRC) is proposed, and the working principle of the compound control strategy is given. ADRC controller is designed, and the extended state observer is used for observing internal parameters uncertainties and external disturbances, so that the disturbances of the system are suppressed effectively. Velocity compensation controller is designed and the compensation model is derived to further improve the positioning accuracy of the system and to achieve the velocity compensation without disturbance. The compound control strategy is verified by the simulation and experiment respectively, and the simulation and experimental results show that the electro-hydraulic position servo control system with ADRC controller can effectively inhibit the external disturbances, the precise positioning control is realized after introducing the velocity compensation controller, and verify that the compound control strategy is effective. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

Effects of cooperation between translating ribosome and RNA polymerase on termination efficiency of the Rho-independent terminator.

PubMed

Li, Rui; Zhang, Qing; Li, Junbai; Shi, Hualin

2016-04-07

An experimental system was designed to measure in vivo termination efficiency (TE) of the Rho-independent terminator and position-function relations were quantified for the terminator tR2 in Escherichia coli The terminator function was almost completely repressed when tR2 was located several base pairs downstream from the gene, and TE gradually increased to maximum values with the increasing distance between the gene and terminator. This TE-distance relation reflected a stochastic coupling of the ribosome and RNA polymerase (RNAP). Terminators located in the first 100 bp of the coding region can function efficiently. However, functional repression was observed when the terminator was located in the latter part of the coding region, and the degree of repression was determined by transcriptional and translational dynamics. These results may help to elucidate mechanisms of Rho-independent termination and reveal genomic locations of terminators and functions of the sequence that precedes terminators. These observations may have important applications in synthetic biology. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

Social contagion of ethnic hostility.

PubMed

Bauer, Michal; Cahlíková, Jana; Chytilová, Julie; Želinský, Tomáš

2018-05-08

Interethnic conflicts often escalate rapidly. Why does the behavior of masses easily change from cooperation to aggression? This paper provides an experimental test of whether ethnic hostility is contagious. Using incentivized tasks, we measured willingness to sacrifice one's own resources to harm others among adolescents from a region with a history of animosities toward the Roma people, the largest ethnic minority in Europe. To identify the influence of peers, subjects made choices after observing either destructive or peaceful behavior of peers in the same task. We found that susceptibility to follow destructive behavior more than doubled when harm was targeted against Roma rather than against coethnics. When peers were peaceful, subjects did not discriminate. We observed very similar patterns in a norms-elicitation experiment: destructive behavior toward Roma was not generally rated as more socially appropriate than when directed at coethnics, but the ratings were more sensitive to social contexts. The findings may illuminate why ethnic hostilities can spread quickly, even in societies with few visible signs of interethnic hatred. Copyright © 2018 the Author(s). Published by PNAS.

Exploring the physics of sand drawings: The role of craters, furrows and piles.

PubMed

González-Gutiérrez, Jorge; Ruiz-Suárez, J C

2017-04-01

Few years ago an article addressing the physics behind aaabstract paintings was published by Herczyński et al. (Phys. Today 64, 31 (2011) issue No. 6). The authors aimed to understand how artists like Jackson Pollock manipulated paints to create pieces of art where the theory of fluid dynamics had a clear and perceivable role. Scaling laws were found to explain the plasticity observed in the artists's traces that we admire in worldwide museums. Because sand drawings are not only wonderful artistic expressions but also intangible cultural heritages of humanity, we wonder if they could be analyzed in a similar fashion. Our goal is to explore the physics behind the formation of such drawings. In order to do so, we carry out experimental studies on the formation of sand cavities, furrows and piles, which individually or interconnected, give rise to artistic patterns. Moreover, in order to manipulate such three observables, some control parameters are needed. Altogether, they conform into simple exponential and power laws that collapse when a scaling is performed.

Do Brazilian scientific journals promote the adherence of Chagas disease researchers to international ethical principles?

PubMed

Malafaia, Guilherme; Guilhem, Dirce; Talvani, André

2013-01-01

The ethical aspects of the Brazilian publications about human Chagas disease (CD) developed between 1996 and 2010 and the policy adopted by Brazilian medical journals were analyzed. Articles were selected on the SciELO Brazil data basis, and the evaluation of ethical aspects was based on the normative contents about ethics in research involving human experimentation according to the Brazilian resolution of the National Health Council no. 196/1996. The editorial policies of the section "Instructions to authors" were analyzed. In the period of 1996-2012, 58.9% of articles involving human Chagas disease did not refer to the fulfillment of the ethical aspects concerning research with human beings. In 80% of the journals, the requirements and confirmation of the information about ethical aspects in the studies of human CD were not observed. Although a failure in this type of service is still observed, awareness has been raised in federal agencies, educational institutions/research and publishing groups to standardize the procedures and ethical requirements for the Brazilian journals, reinforcing the fulfillment of the ethical parameters, according to the resolution of NHC no. 196/1996.

Modeling viscous dissipation during vocal fold contact: the influence of tissue viscosity and thickness with implications for hydration.

PubMed

Erath, Byron D; Zañartu, Matías; Peterson, Sean D

2017-06-01

The mechanics of vocal fold contact during phonation is known to play a crucial role in both normal and pathological speech production, though the underlying physics is not well understood. Herein, a viscoelastic model of the stresses during vocal fold contact is developed. This model assumes the cover to be a poroelastic structure wherein interstitial fluid translocates in response to mechanical squeezing. The maximum interstitial fluid pressure is found to generally increase with decreasing viscous dissipation and/or decreasing tissue elasticity. A global minimum in the total contact stress, comprising interstitial fluid pressure and elastic stress in the tissue, is observed over the studied dimensionless parameter range. Interestingly, physiologically reasonable estimates for the governing parameters fall within this global minimum region. The model is validated against prior experimental and computational work, wherein the predicted contact stress magnitude and impact duration agree well with published results. Lastly, observations of the potential relationship between vocal fold hydration and increased risk of tissue damage are discussed based upon model predictions of stress as functions of cover layer thickness and viscosity.

Energy budget for yearling lake trout, Salvelinus namaycush

USGS Publications Warehouse

Rottiers, Donald V.

1993-01-01

Components of the energy budget of yearling lake trout (Salvelinus namaycush) were derived from data gathered in laboratory growth and metabolism studies; values for energy lost as waste were estimated with previously published equations. Because the total caloric value of food consumed by experimental lake trout was significantly different during the two years in which the studies were done, separate annual energy budgets were formulated. The gross conversion efficiency in yearling lake trout fed ad libitum rations of alewives at 10A?C was 26.6% to 41%. The distribution of energy with temperature was similar for each component of the energy budget. Highest conversion efficiencies were observed in fish fed less than ad libitum rations; fish fed an amount of food equivalent to about 4% of their body weight at 10A?C had a conversion efficiency of 33% to 45.1%. Physiologically useful energy was 76.1-80.1% of the total energy consumed. Estimated growth for age-I and -II lake fish was near that observed for laboratory fish held at lake temperatures and fed reduced rations.

Supercritical bedforms and sedimentary structures from field and core studies, Middle Eocene deep-marine base-of-slope environment, Ainsa Basin, Spanish Pyrenees

NASA Astrophysics Data System (ADS)

Cornard, Pauline; Pickering, Kevin

2017-04-01

In recent years, many researchers have focussed on supercritical- and subcritical-flow deposits using flume-tank experiments (e.g., Cartigny el al., 2011; Postma et al., 2014; Postma and Cartigny, 2014), or from direct observations on presently active deep-water systems (e.g., Hughes et al., 2012). Using outcrop and core examples from a base-of-slope environment in the Middle Eocene Ainsa Basin, Spanish Pyrenees, and with published experimental work, a range of deposits are interpreted as upper-flow regime sedimentary structures. This contribution focusses on the interpretation of several supercritical bedforms (antidunes and chutes-and-pools) observed on the field and upper-flow regime sedimentary structures recognized in cores. The spatial distribution of supercritical-flow deposits obtained from an analysis of field outcrops and core sedimentary logs are evaluated in relation to the depositional environment (channel axis, off-axis, margin and interfan). The frequency distributions of the bed thicknesses are also analysed in relation to supercritical versus subcritical bed-thickness distributions.