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Sample records for natural background approach

  1. Teaching about Natural Background Radiation

    ERIC Educational Resources Information Center

    Al-Azmi, Darwish; Karunakara, N.; Mustapha, Amidu O.

    2013-01-01

    Ambient gamma dose rates in air were measured at different locations (indoors and outdoors) to demonstrate the ubiquitous nature of natural background radiation in the environment and to show that levels vary from one location to another, depending on the underlying geology. The effect of a lead shield on a gamma radiation field was also…

  2. Teaching about natural background radiation

    NASA Astrophysics Data System (ADS)

    Al-Azmi, Darwish; Karunakara, N.; Mustapha, Amidu O.

    2013-07-01

    Ambient gamma dose rates in air were measured at different locations (indoors and outdoors) to demonstrate the ubiquitous nature of natural background radiation in the environment and to show that levels vary from one location to another, depending on the underlying geology. The effect of a lead shield on a gamma radiation field was also demonstrated to emphasize the important role of shielding in radiation protection. The measurements were carried out with a Geiger-Muller (GM)-based dosimeter and a NaI scintillation gamma-ray spectrometer, which are normally available in physics laboratories. Radioactivity in household materials was demonstrated using a gas mantle as an example.

  3. Estimating COCOM Natural Background Dormancy

    DTIC Science & Technology

    2015-04-01

    phenological stage, controls color and tex- ture of natural vegetation as it cycles through greenup, verdancy, senes- cence, and dormancy. For the Army... cycle patterns: (a) a single, complete growth cycle ; (b–d) two partial cycles ; (e) two complete growth cycles ; and (f–h) one complete cycle and two...incomplete cycles ............................................................................... 17 9 Maps of the mean MLD in days and standard

  4. Ambient background particulate composition, outdoor natural background: interferents/clutter

    NASA Astrophysics Data System (ADS)

    Paterno, Dorothea

    2012-06-01

    It has proven a very difficult task to discriminate an actual BW threat from the natural occurring ambient particulate aerosol, which includes a significant fraction of particles consisting of mixed mineral and biological material. The interferent particles [clutter] (bio and non bio) concentration varies widely both by location, weather and season and diurnally. Naturally occurring background particulates are composed of fungal and bacterial spores both fragments and components, plant fragments and debris, animal fragments and debris, all of which may be associated with inert dust or combustion material. Some or all of which could also be considered to be an interferent to a biological warfare detector and cause these biodector systems to cause False Alarms by non specific BW bio detectors. I will share analysis of current long term background data sets.

  5. Speech Recognition in Natural Background Noise

    PubMed Central

    Meyer, Julien; Dentel, Laure; Meunier, Fanny

    2013-01-01

    In the real world, human speech recognition nearly always involves listening in background noise. The impact of such noise on speech signals and on intelligibility performance increases with the separation of the listener from the speaker. The present behavioral experiment provides an overview of the effects of such acoustic disturbances on speech perception in conditions approaching ecologically valid contexts. We analysed the intelligibility loss in spoken word lists with increasing listener-to-speaker distance in a typical low-level natural background noise. The noise was combined with the simple spherical amplitude attenuation due to distance, basically changing the signal-to-noise ratio (SNR). Therefore, our study draws attention to some of the most basic environmental constraints that have pervaded spoken communication throughout human history. We evaluated the ability of native French participants to recognize French monosyllabic words (spoken at 65.3 dB(A), reference at 1 meter) at distances between 11 to 33 meters, which corresponded to the SNRs most revealing of the progressive effect of the selected natural noise (−8.8 dB to −18.4 dB). Our results showed that in such conditions, identity of vowels is mostly preserved, with the striking peculiarity of the absence of confusion in vowels. The results also confirmed the functional role of consonants during lexical identification. The extensive analysis of recognition scores, confusion patterns and associated acoustic cues revealed that sonorant, sibilant and burst properties were the most important parameters influencing phoneme recognition. . Altogether these analyses allowed us to extract a resistance scale from consonant recognition scores. We also identified specific perceptual consonant confusion groups depending of the place in the words (onset vs. coda). Finally our data suggested that listeners may access some acoustic cues of the CV transition, opening interesting perspectives for future studies

  6. A review on natural background radiation

    PubMed Central

    Shahbazi-Gahrouei, Daryoush; Gholami, Mehrdad; Setayandeh, Samaneh

    2013-01-01

    The world is naturally radioactive and approximately 82% of human-absorbed radiation doses, which are out of control, arise from natural sources such as cosmic, terrestrial, and exposure from inhalation or intake radiation sources. In recent years, several international studies have been carried out, which have reported different values regarding the effect of background radiation on human health. Gamma radiation emitted from natural sources (background radiation) is largely due to primordial radionuclides, mainly 232Th and 238U series, and their decay products, as well as 40K, which exist at trace levels in the earth's crust. Their concentrations in soil, sands, and rocks depend on the local geology of each region in the world. Naturally occurring radioactive materials generally contain terrestrial-origin radionuclides, left over since the creation of the earth. In addition, the existence of some springs and quarries increases the dose rate of background radiation in some regions that are known as high level background radiation regions. The type of building materials used in houses can also affect the dose rate of background radiations. The present review article was carried out to consider all of the natural radiations, including cosmic, terrestrial, and food radiation. PMID:24223380

  7. Background radiation: natural and man-made.

    PubMed

    Thorne, M C

    2003-03-01

    A brief overview and comparison is given of dose rates arising from natural background radiation and the fallout from atmospheric testing of nuclear weapons. Although there are considerable spatial variations in exposure to natural background radiation, it is useful to give estimates of worldwide average overall exposures from the various components of that background. Cosmic-ray secondaries of low linear energy transfer (LET), mainly muons and photons, deliver about 280 microSv a(-1). Cosmic-ray neutrons deliver about another 100 microSv a(-1). These low- and high-LET exposures are relatively uniform to the whole body. The effective dose rate from cosmogenic radionuclides is dominated by the contribution of 12 microSv a(-1) from 14C. This is due to relatively uniform irradiation of all organs and tissues from low-energy beta particles. Primordial radionuclides and their progeny (principally the 238U and 232Th series, and 40K) contribute about 480 microSv a(-1) of effective dose by external irradiation. This is relatively uniform photon irradiation of the whole body. Internally incorporated 40K contributes a further 165 microSv a(-1) of effective dose in adults, mainly from beta particles, but with a significant gamma component. Equivalent doses from 40K are somewhat higher in muscle than other soft tissues, but the distinction is less than a factor of three. Uranium and thorium series radionuclides give rise to an average effective dose rate of around 120 microSv a(-1). This includes a major alpha particle component, and exposures of radiosensitive tissues in lung, liver, kidney and the skeleton are recognised as important contributors to effective dose. Overall, these various sources give a worldwide average effective dose rate of about 1160 microSv a(-1). Exposure to 222Rn, 220Rn and their short-lived progeny has to be considered separately. This is very variable both within and between countries. For 222Rn and its progeny, a worldwide average effective dose

  8. Ambient Background Particulate Compositiion Outdoor Natural Background: Interferents/Clutter

    DTIC Science & Technology

    2011-08-01

    the biological warfare detection world), you must conduct long term ( seasonally ) particulate monitoring. Anecdotal short term monitoring attempts...particulates (interferents or clutter) in the lower atmosphere at four locations along a transect in the UK for 2 years. In addition, seasonal , diurnal...CONTENTS 1. INTRODUCTION/BACKGROUND 9 2. UK AEROSOL BIODIVERSITY STUDY-2 YEARS, FOUR LOCATIONS. FOUR SEASONS 10 3. DoD SPONSORED ANAL YSIS OF UK

  9. Sinning against nature: the theory of background conditions

    PubMed Central

    Blackford, R

    2006-01-01

    Debates about the moral and political acceptability of particular sexual practices and new technologies often include appeals to a supposed imperative to follow nature. If nature is understood as the totality of all phenomena or as those things that are not artificial, there is little prospect of developing a successful argument to impugn interference with it or sinning against it. At the same time, there are serious difficulties with approaches that seek to identify "proper" human functioning. An alternative approach is to understand interference with nature as acting in a manner that threatens basic background conditions to human choice. Arguably, the theory of background conditions helps explain much of the hostility to practices and technologies that allegedly sin against nature. The theory does not, however, entail that appeals to nature are relevant or rational. Such appeals should be subjected to sceptical scrutiny. Indeed, the theory suggests that arguments against practices and technologies that can be seen as contrary to nature sometimes exercise a psychological attraction that is disproportional to their actual cogency. PMID:17074819

  10. Sinning against nature: the theory of background conditions.

    PubMed

    Blackford, R

    2006-11-01

    Debates about the moral and political acceptability of particular sexual practices and new technologies often include appeals to a supposed imperative to follow nature. If nature is understood as the totality of all phenomena or as those things that are not artificial, there is little prospect of developing a successful argument to impugn interference with it or sinning against it. At the same time, there are serious difficulties with approaches that seek to identify "proper" human functioning. An alternative approach is to understand interference with nature as acting in a manner that threatens basic background conditions to human choice. Arguably, the theory of background conditions helps explain much of the hostility to practices and technologies that allegedly sin against nature. The theory does not, however, entail that appeals to nature are relevant or rational. Such appeals should be subjected to sceptical scrutiny. Indeed, the theory suggests that arguments against practices and technologies that can be seen as contrary to nature sometimes exercise a psychological attraction that is disproportional to their actual cogency.

  11. Chromo-natural model in anisotropic background

    SciTech Connect

    Maleknejad, Azadeh; Erfani, Encieh E-mail: eerfani@ipm.ir

    2014-03-01

    In this work we study the chromo-natural inflation model in the anisotropic setup. Initiating inflation from Bianchi type-I cosmology, we analyze the system thoroughly during the slow-roll inflation, from both analytical and numerical points of view. We show that the isotropic FRW inflation is an attractor of the system. In other words, anisotropies are damped within few e-folds and the chromo-natural model respects the cosmic no-hair conjecture. Furthermore, we demonstrate that in the slow-roll limit, the anisotropies in both chromo-natural and gauge-flation models share the same dynamics.

  12. Assessment of natural background levels in potentially contaminated coastal aquifers.

    PubMed

    Molinari, A; Chidichimo, F; Straface, S; Guadagnini, A

    2014-04-01

    The estimation of natural background levels (NBLs) of dissolved concentrations of target chemical species in subsurface reservoirs relies on a proper assessment of the effects of forcing terms driving flow and transport processes taking place within the system and whose dynamics drive background concentration values. We propose coupling methodologies based on (a) global statistical analyses and (b) numerical modeling of system dynamics to distinguish between the impacts of different types of external forcing components influencing background concentration values. We focus on the joint application of a statistical methodology based on Component Separation and experimental/numerical modeling studies of groundwater flow and transport for the NBL estimation of selected chemical species in potentially contaminated coastal aquifers. We consider a site which is located in Calabria, Italy, and constitutes a typical example of a Mediterranean coastal aquifer which has been subject to intense industrial development. Our study is keyed to the characterization of NBLs of manganese and sulfate and is geared to the proper identification of the importance of a natural external forcing (i.e., seawater intrusion) on NBL assessment. Results from the Component Separation statistical approach are complemented by numerical simulations of the advective-dispersive processes that could influence the distribution of chemical species (i.e., sulfate) within the system. Estimated NBLs for manganese are consistent with the geochemical composition of soil samples. While Component Separation ascribes the largest detected sulfate concentrations to anthropogenic sources, our numerical modeling analysis suggests that they are mainly related to the natural process of seawater intrusion. Our results indicate that the use of statistical methodologies in complex groundwater systems should be assisted by a detailed characterization of the dynamics of natural (and/or induced) processes to distinguish

  13. Image Discrimination Models Predict Object Detection in Natural Backgrounds

    NASA Technical Reports Server (NTRS)

    Ahumada, Albert J., Jr.; Rohaly, A. M.; Watson, Andrew B.; Null, Cynthia H. (Technical Monitor)

    1994-01-01

    Object detection involves looking for one of a large set of object sub-images in a large set of background images. Image discrimination models only predict the probability that an observer will detect a difference between two images. In a recent study based on only six different images, we found that discrimination models can predict the relative detectability of objects in those images, suggesting that these simpler models may be useful in some object detection applications. Here we replicate this result using a new, larger set of images. Fifteen images of a vehicle in an other-wise natural setting were altered to remove the vehicle and mixed with the original image in a proportion chosen to make the target neither perfectly recognizable nor unrecognizable. The target was also rotated about a vertical axis through its center and mixed with the background. Sixteen observers rated these 30 target images and the 15 background-only images for the presence of a vehicle. The likelihoods of the observer responses were computed from a Thurstone scaling model with the assumption that the detectabilities are proportional to the predictions of an image discrimination model. Three image discrimination models were used: a cortex transform model, a single channel model with a contrast sensitivity function filter, and the Root-Mean-Square (RMS) difference of the digital target and background-only images. As in the previous study, the cortex transform model performed best; the RMS difference predictor was second best; and last, but still a reasonable predictor, was the single channel model. Image discrimination models can predict the relative detectabilities of objects in natural backgrounds.

  14. Effect of natural background radiation on dermatoglyphic traits.

    PubMed

    Bhasin, M K; Malik, S L; Grewal, M S; Singh, I P; Sudarshan, K J; Kochupillai, N; Verma, I C

    1980-01-01

    Long term exposure to natural background radiation could cause gross abnormalities in individuals and at the population level. Studies conducted on the coastal Kerala population which is known to be receiving fifteen times the normal permissible dose of radiation support this. This study aims at understanding the deviations, if any, in the normal human variation as a result of such high natural radiation. A detailed quantitative and qualitative dermatoglyphic study was done on two communities i.e. Hindus and Christians, living separately in the radiation area. The significant differences were observed between control and exposed groups with regard to d-t ridge count, distances c-t and angle atd. The susceptibility of the axial triradius to environmental distrubances is discussed.

  15. Using Natural Approach Teaching Techniques.

    ERIC Educational Resources Information Center

    Whitman, Charles

    1986-01-01

    Describes a beginning foreign language class applying the principles of Stephen Krashen's "Natural Approach" and James Asher's "Total Physical Response" method. Initially students carry out the instructor's commands in the form of actions rather than being required to speak. In later stages role play and simple discussions are…

  16. The ROSCOE MANUAL. Volume 27: Natural background radiation

    NASA Astrophysics Data System (ADS)

    Hamlin, D. A.; Schoonover, M. R.

    1980-07-01

    The Natural Background Radiation Module computes the Earth's natural upwelling spectral radiance (from 2 to 5 micrometers) by averaging over paths in an Earth-tangent cone with vertex at each selected altitude. The processes contributing to the radiance are emission from air, Earth's surface, and clouds and reflection of solar radiation from Earth's surface and clouds; attenuation is by molecules and aerosols. The Module integrates ROSCOE-IR models for atmosphere, atmospheric thermal emission, molecular transmittance, aerosols, clouds, Earth's surface characterization and radiance, solar radiation, and upwelling natural radiation. The last 3 models are documented fully; other models (three of which were developed by other organizations) are documented mainly in terms of functions performed, inputs, and outputs. The user selects the modeled Earth's surface from one of seven categories (with possibly an associated descriptor): Lambertian surface (and diffuse reflectance), wind-ruffled water (and wind speed), snow (and its age parameter), sand, soil, foliage, and urban material (and degree-of-urbanization parameter).

  17. In-mine testing of a natural background sensor, part B

    NASA Technical Reports Server (NTRS)

    Martzloff, F. D.

    1981-01-01

    The capability of a natural background sensor for measuring the thickness of top coal on a longwall face was examined. The limitations on the time during which tests could be performed, and the roof conditions, did not produce readings of top coal measurements during the shearer operation. It was demonstrated that the system is capable to survive operating conditions in the mine environment, while the static tests confirmed that the natural background sensor approach is a valid method of measuring top coal thickness in mines where the roof rock provides a constant radiation level. It is concluded that the practical results will improve sequent development of an integrated vertical control system which is information from the natural background system.

  18. Using epicenter location to differentiate events from natural background seismicity

    SciTech Connect

    Myers, S C; Walter, W R

    1999-07-26

    Efforts to more effectively monitor the Comprehensive Nuclear-Test-Ban Treaty (commonly referred to as the CTBT) include research into methods of seismic discrimination. The most common seismic discriminants exploit differences in seismic amplitude for differing source types. Amplitude discriminants are quite effective when wave-propagation (a.k.a. path) effects are properly accounted for. However, because path effects can be exceedingly complex, path calibration is often accomplished empirically by spatially interpolating amplitude characteristics for a set of calibration earthquakes with techniques like Bayesian kriging. As a result, amplitude discriminants can be highly effective when natural seismicity provides sufficient event coverage to characterize a region. However, amplitude discrimination can become less effective for events that are far from historical (path-calibration) events. It is intuitive that events occurring at a distance from historical seismicity patterns are inherently suspect. However, quantifying the degree to which a particular event is unexpected could be of great utility in CTBT monitoring. Epicenter location is commonly used as a qualitative discriminant. For instance, if a seismic event is located in the deep ocean, then the event is generally considered to be an earthquake. Such qualitative uses of seismic location have great utility; however, a quantitative method to differentiate events from the natural pattern of seismicity could significantly advance the applicability of location as a discriminant for source type. Clustering of earthquake epicenters is the underlying aspect of earthquake seismicity that allows for an epicenter-based discriminant, and we explore the use of fractal characterization of clustering to characterize seismicity patters. We then evaluate the likelihood that an event at any given location is drawn from the background population. The use of this technique can help to identifying events that are inconsistent

  19. Estimating natural background groundwater chemistry, Questa molybdenum mine, New Mexico

    USGS Publications Warehouse

    Verplanck, Phillip L.; Nordstrom, D. Kirk; Plumlee, Geoffrey S.; Walker, Bruce M.; Morgan, Lisa A.; Quane, Steven L.

    2010-01-01

    This 2 1/2 day field trip will present an overview of a U.S. Geological Survey (USGS) project whose objective was to estimate pre-mining groundwater chemistry at the Questa molybdenum mine, New Mexico. Because of intense debate among stakeholders regarding pre-mining groundwater chemistry standards, the New Mexico Environment Department and Chevron Mining Inc. (formerly Molycorp) agreed that the USGS should determine pre-mining groundwater quality at the site. In 2001, the USGS began a 5-year, multidisciplinary investigation to estimate pre-mining groundwater chemistry utilizing a detailed assessment of a proximal natural analog site and applied an interdisciplinary approach to infer pre-mining conditions. The trip will include a surface tour of the Questa mine and key locations in the erosion scar areas and along the Red River. The trip will provide participants with a detailed understanding of geochemical processes that influence pre-mining environmental baselines in mineralized areas and estimation techniques for determining pre-mining baseline conditions.

  20. Is natural background or radiation from nuclear power plants leukemogenic

    SciTech Connect

    Cronkite, E.P.

    1989-01-01

    The objective in this review is to provide some facts about normal hemopoietic cell proliferation relevant to leukemogenesis, physical, chemical, and biological facts about radiation effects with the hope that each person will be able to decide for themselves whether background radiation or emissions from nuclear power plants and facilities significantly add to the spontaneous leukemia incidence. 23 refs., 1 tab.

  1. Natural approach to quantum dissipation

    NASA Astrophysics Data System (ADS)

    Taj, David; Öttinger, Hans Christian

    2015-12-01

    The dissipative dynamics of a quantum system weakly coupled to one or several reservoirs is usually described in terms of a Lindblad generator. The popularity of this approach is certainly due to the linear character of the latter. However, while such linearity finds justification from an underlying Hamiltonian evolution in some scaling limit, it does not rely on solid physical motivations at small but finite values of the coupling constants, where the generator is typically used for applications. The Markovian quantum master equations we propose are instead supported by very natural thermodynamic arguments. They themselves arise from Markovian master equations for the system and the environment which preserve factorized states and mean energy and generate entropy at a non-negative rate. The dissipative structure is driven by an entropic map, called modular, which introduces nonlinearity. The generated modular dynamical semigroup (MDS) guarantees for the positivity of the time evolved state the correct steady state properties, the positivity of the entropy production, and a positive Onsager matrix with symmetry relations arising from Green-Kubo formulas. We show that the celebrated Davies Lindblad generator, obtained through the Born and the secular approximations, generates a MDS. In doing so we also provide a nonlinear MDS which is supported by a weak coupling argument and is free from the limitations of the Davies generator.

  2. A novel approach to model EPIC variable background

    NASA Astrophysics Data System (ADS)

    Marelli, M.; De Luca, A.; Salvetti, D.; Belfiore, A.; Pizzocaro, D.

    2016-06-01

    In the past years XMM-Newton revolutionized our way to look at the X-ray sky. With more than 200 Ms of exposure, it allowed for numerous discoveries in every field of astronomy. Unfortunately, about 35% of the observing time is badly affected by soft proton flares, with background increasing by orders of magnitudes hampering any classical analysis of field sources. One of the main aim of the EXTraS ("Exploring the X-ray Transient and variable Sky") project is to characterise the variability of XMM-Newton sources within each single observation, including periods of high background. This posed severe challenges. I will describe a novel approach that we implemented within the EXTraS project to produce background-subtracted light curves, that allows to treat the case of very faint sources and very large proton flares. EXTraS light curves will be soon released to the community, together with new tools that will allow the user to reproduce EXTraS results, as well as to extend a similar analysis to future data. Results of this work (including an unprecedented characterisation of the soft proton phenomenon and instrument response) will also serve as a reference for future missions and will be particularly relevant for the Athena observatory.

  3. Hidden in the background: a local approach to CMB anomalies

    NASA Astrophysics Data System (ADS)

    Bueno Sánchez, Juan C.

    2016-09-01

    We investigate a framework aiming to provide a common origin for the large-angle anomalies detected in the Cosmic Microwave Background (CMB), which are hypothesized as the result of the statistical inhomogeneity developed by different isocurvature fields of mass m~ H present during inflation. The inhomogeneity arises as the combined effect of (i) the initial conditions for isocurvature fields (obtained after a fast-roll stage finishing many e-foldings before cosmological scales exit the horizon), (ii) their inflationary fluctuations and (iii) their coupling to other degrees of freedom. Our case of interest is when these fields (interpreted as the precursors of large-angle anomalies) leave an observable imprint only in isolated patches of the Universe. When the latter intersect the last scattering surface, such imprints arise in the CMB. Nevertheless, due to their statistically inhomogeneous nature, these imprints are difficult to detect, for they become hidden in the background similarly to the Cold Spot. We then compute the probability that a single isocurvature field becomes inhomogeneous at the end of inflation and find that, if the appropriate conditions are given (which depend exclusively on the preexisting fast-roll stage), this probability is at the percent level. Finally, we discuss several mechanisms (including the curvaton and the inhomogeneous reheating) to investigate whether an initial statistically inhomogeneous isocurvature field fluctuation might give rise to some of the observed anomalies. In particular, we focus on the Cold Spot, the power deficit at low multipoles and the breaking of statistical isotropy.

  4. The natural approach to osteoporosis

    PubMed Central

    Bartolozzi, Emanuela

    2015-01-01

    Summary Osteoporosis is normally the result of a wrong life-style (diet, physical inactivity, smoke, dental hygiene, intestinal dysbiosis,…) and environmental toxicity which stimulate the chronic expression of inflammatory genes and alter the immuno-endocrine balance. A natural approch should face all the factors involved, leading the patients to become aware of their own responsability, and helping them with natural therapies, healthy food and life-style which support their body in the process of self-healing. PMID:26604935

  5. Natural Approaches to Reading and Writing.

    ERIC Educational Resources Information Center

    Antonacci, Patricia; Hedley, Carolyn

    Based on a two-day presentation workshop on early reading and writing approaches, the 12 essays in this book discuss the development of literacy, natural approaches in developing literacy, and supporting literacy development. Essays in the book are: (1) "Theories of Natural Language" (Carolyn N. Hedley); (2) "Oral Language…

  6. Anisotropies in the cosmic microwave background: an analytic approach

    NASA Astrophysics Data System (ADS)

    Hu, Wayne; Sugiyama, Naoshi

    1995-05-01

    We introduce a conceptually simple yet powerful analytic method which traces the structure of cosmic microwave background anisotropies to better than 5%-10% in temperature fluctuations on all scales. It is applicable to any model in which the gravitational potential is known and last scattering is sufficiently early. Moreover, it recovers and explains the presence of the 'Doppler peaks' at degree scales as driven acoustic oscillations of the photon-baryon fluid. We treat in detail such subtleties as the time dependence of the gravitational driving force, anisotropic stress from the neutrino quadrupole, and damping during the recombination process, again all from an analytic standpoint. We apply this formalism to the standard cold dark matter model to gain physical insight into the anisotropies, including the dependence of the peak locations and heights on cosmological parameters such as Omegab and h. Furthermore, the ionization history controls damping due to the finite thickness of the last scattering surface, which is in fact mianly caused by photon diffusion. In addition to being a powerful probe into the nature of anisotropies, this treatment can be used in place of the standard Boltzmann code where 5%-10% accuracy in temperature fluctuations is satisfactory and/or speed is essential. Equally importantly, it can be used as a portable standard by which numerical codes can be tested and compared.

  7. Adaptive log-quadratic approach for target detection in nonhomogeneous backgrounds perturbed with speckle fluctuations.

    PubMed

    Magraner, Eric; Bertaux, Nicolas; Réfrégier, Philippe

    2008-12-01

    An approach for point target detection in the presence of speckle fluctuations with nonhomogeneous backgrounds is proposed. This approach is based on an automatic selection between the standard constant background model and a quadratic model for the logarithm of the background values. An improvement of the regulation of the false alarm probability in nonhomogeneous backgrounds is demonstrated.

  8. A Novel Approach to Deepen Understanding of Undergraduates' Environmental Backgrounds

    ERIC Educational Resources Information Center

    Hvenegaard, Glen

    2007-01-01

    Universities often lack a detailed understanding of the environmental backgrounds of their students. One way to improve understanding is through segmentation, which breaks down a population into groups of people with similar characteristics. This study aims to use segmentation to determine groups within the student population, based on…

  9. Human Blood Typing: A Forensic Science Approach. Part I: Background.

    ERIC Educational Resources Information Center

    Kobilinsky, Lawrence; Sheehan, Francis X.

    1988-01-01

    In this article, part I of a series, the forensic methods used in "typing" human blood, which as physical evidence is often found in the dried state, are outlined. Background information about individualization, antibody typing, fresh blood, dried blood, and additional systems is provided. (CW)

  10. Computational Assessment of Naturally Occurring Neutron and Photon Background Radiation Produced by Extraterrestrial Sources

    SciTech Connect

    Miller, Thomas Martin; de Wet, Wouter C.; Patton, Bruce W.

    2015-10-28

    In this study, a computational assessment of the variation in terrestrial neutron and photon background from extraterrestrial sources is presented. The motivation of this assessment is to evaluate the practicality of developing a tool or database to estimate background in real time (or near–real time) during an experimental measurement or to even predict the background for future measurements. The extraterrestrial source focused on during this assessment is naturally occurring galactic cosmic rays (GCRs). The MCNP6 transport code was used to perform the computational assessment. However, the GCR source available in MCNP6 was not used. Rather, models developed and maintained by NASA were used to generate the GCR sources. The largest variation in both neutron and photon background spectra was found to be caused by changes in elevation on Earth's surface, which can be as large as an order of magnitude. All other perturbations produced background variations on the order of a factor of 3 or less. The most interesting finding was that ~80% and 50% of terrestrial background neutrons and photons, respectively, are generated by interactions in Earth's surface and other naturally occurring and man-made objects near a detector of particles from extraterrestrial sources and their progeny created in Earth's atmosphere. In conclusion, this assessment shows that it will be difficult to estimate the terrestrial background from extraterrestrial sources without a good understanding of a detector's surroundings. Therefore, estimating or predicting background during a measurement environment like a mobile random search will be difficult.

  11. An efficient background modeling approach based on vehicle detection

    NASA Astrophysics Data System (ADS)

    Wang, Jia-yan; Song, Li-mei; Xi, Jiang-tao; Guo, Qing-hua

    2015-10-01

    The existing Gaussian Mixture Model(GMM) which is widely used in vehicle detection suffers inefficiency in detecting foreground image during the model phase, because it needs quite a long time to blend the shadows in the background. In order to overcome this problem, an improved method is proposed in this paper. First of all, each frame is divided into several areas(A, B, C and D), Where area A, B, C and D are decided by the frequency and the scale of the vehicle access. For each area, different new learning rate including weight, mean and variance is applied to accelerate the elimination of shadows. At the same time, the measure of adaptive change for Gaussian distribution is taken to decrease the total number of distributions and save memory space effectively. With this method, different threshold value and different number of Gaussian distribution are adopted for different areas. The results show that the speed of learning and the accuracy of the model using our proposed algorithm surpass the traditional GMM. Probably to the 50th frame, interference with the vehicle has been eliminated basically, and the model number only 35% to 43% of the standard, the processing speed for every frame approximately has a 20% increase than the standard. The proposed algorithm has good performance in terms of elimination of shadow and processing speed for vehicle detection, it can promote the development of intelligent transportation, which is very meaningful to the other Background modeling methods.

  12. Cancer Mortality Among People Living in Areas With Various Levels of Natural Background Radiation.

    PubMed

    Dobrzyński, Ludwik; Fornalski, Krzysztof W; Feinendegen, Ludwig E

    2015-01-01

    There are many places on the earth, where natural background radiation exposures are elevated significantly above about 2.5 mSv/year. The studies of health effects on populations living in such places are crucially important for understanding the impact of low doses of ionizing radiation. This article critically reviews some recent representative literature that addresses the likelihood of radiation-induced cancer and early childhood death in regions with high natural background radiation. The comparative and Bayesian analysis of the published data shows that the linear no-threshold hypothesis does not likely explain the results of these recent studies, whereas they favor the model of threshold or hormesis. Neither cancers nor early childhood deaths positively correlate with dose rates in regions with elevated natural background radiation.

  13. Cancer Mortality Among People Living in Areas With Various Levels of Natural Background Radiation

    PubMed Central

    Fornalski, Krzysztof W.; Feinendegen, Ludwig E.

    2015-01-01

    There are many places on the earth, where natural background radiation exposures are elevated significantly above about 2.5 mSv/year. The studies of health effects on populations living in such places are crucially important for understanding the impact of low doses of ionizing radiation. This article critically reviews some recent representative literature that addresses the likelihood of radiation-induced cancer and early childhood death in regions with high natural background radiation. The comparative and Bayesian analysis of the published data shows that the linear no-threshold hypothesis does not likely explain the results of these recent studies, whereas they favor the model of threshold or hormesis. Neither cancers nor early childhood deaths positively correlate with dose rates in regions with elevated natural background radiation. PMID:26674931

  14. Genomic Approaches with Natural Fish Populations

    PubMed Central

    Oleksiak, M. F.

    2011-01-01

    Natural populations versus inbred stocks provide a much richer resource for identifying the effects of nucleotide substitutions because natural populations have greater polymorphism. Additionally, natural populations offer an advantage over most common research organisms because they are subject to natural selection, and analyses of these adaptations can be used to identify biologically important changes. Among fishes, these analyses are enhanced by having a wide diversity of species (> 28,000 species, more than any other group of vertebrates) living in a huge range of environments (from below freezing to > 46° C, in fresh water to salinities > 40 ppt.). Moreover, fishes exhibit many different life history and reproductive strategies and have many different phenotypes and social structures. While fishes provide numerous advantages over other vertebrate models, there is still a dearth of available genomic tools for fishes. Fish make up approximately half of all known vertebrate species, yet less than 0.2% of fish species have significant genomic resources. Nonetheless, genomic approaches with fishes have provided some of the first measures of individual variation in gene expression and insights in to environmental and ecological adaptations. Thus, genomic approaches with natural fish populations have the potential to revolutionize fundamental studies of diverse fish species that offer myriad ecological and evolutionary questions. PMID:20409163

  15. Hydrogeochemical characterization and Natural Background Levels in urbanized areas: Milan Metropolitan area (Northern Italy)

    NASA Astrophysics Data System (ADS)

    De Caro, Mattia; Crosta, Giovanni B.; Frattini, Paolo

    2017-04-01

    Although aquifers in densely populated and industrialized areas are extremely valuable and sensitive to contamination, an estimate of the groundwater quality status relative to baseline conditions is lacking for many of them. This paper provides a hydrogeochemical characterization of the groundwater in the Milan metropolitan area, one of the most densely populated areas in Europe. First, a conceptual model of the study area based on the analysis of the spatial distribution of natural chemical species and indicator contaminants is presented. The hydrochemical facies of the study area depend on the lithology of catchments drained by the main contributing rivers and on the aquifer settings. The anthropogenic influence on the groundwater quality of superficial aquifers is studied by means of probability plots, concentration versus depth plots and spatial-temporal plots for nitrate, sulfate and chloride. These allow differentiation of contaminated superficial aquifers from deep confined aquifers with baseline water quality. Natural Background Levels (NBL) of selected species (Cl, Na, NH4, SO4, NO3, As, Fe, Mn and Zn) are estimated by means of the pre-selection (PS) and the component separation (CS) statistical approaches. The NBLs depend on hydrogeological settings of the study area; sodium, chloride, sulfate and zinc NBL values never exceed the environmental water quality standards. NBL values of ammonium, iron, arsenic and manganese exceed the environmental water quality standards in the anaerobic portion of the aquifers. On the basis of observations, a set of criteria and precautions are suggested for adoption with both PS and CS methods in the aquifer characterization of highly urbanized areas.

  16. Geochemistry, biota and natural background levels in an arsenic naturally contaminated volcanic aquifer

    NASA Astrophysics Data System (ADS)

    Preziosi, Elisabetta; Amalfitano, Stefano; Di Lorenzo, Tiziana; Parrone, Daniele; Rossi, David; Ghergo, Stefano; Lungarini, Silvia; Zoppini, Anna Maria

    2015-04-01

    The tight links between chemical and ecological status are largely acknowledged as for surface water bodies, while aquifers are still considered as hidden groundwater reservoirs, rather than ecosystems to be preserved. Geochemical and biological interactions play a key role in all subterranean processes, including the dynamics of the fate of anthropogenic contaminants. Studies on groundwater dependent ecosystems (GDE) were mainly focused on karst aquifers so far, but an increased awareness on the importance of water-rock interactions and methodological improvements in microbial ecology are rapidly increasing the level of characterization of groundwater ecosystems in various hydrogeological contexts. Similarly, knowledge about groundwater biodiversity is still limited, especially if porous habitats are concerned. Yet, groundwater and GDEs are populated by a diverse and highly adapted biota, dominated by crustaceans, which provide important ecosystem services and act as biological indicators of chemical and quantitative impact on groundwater resources. In a previous research (Amalfitano et al. 2014), we reported that the microbial community heterogeneity may reflect the lithological and hydrogeological complexity within volcanic and alluvial facies transition in a groundwater body. The quantitative tracking of the microbial community structure allowed disentangling the natural biogeochemical processes evolving within the aquifer flow path. The analyses of groundwater crustaceans assemblages may contribute to shed more light upon the state and dynamics of such ecosystems. In the present research, a comprehensive study of a water table aquifer flowing through a quaternary volcanic district is being performed, including the geochemical (inorganic) composition, the microbial composition, and the analysis of crustacean assemblages . Groundwater samples are periodically collected from private wells and springs under a low anthropic impact. The key issues within the

  17. Neurochemical background and approaches in the understanding of motion sickness

    NASA Technical Reports Server (NTRS)

    Kohl, R. L.

    1982-01-01

    The problems and nature of space motion sickness were defined. The neurochemical and neurophysiological bases of vestibular system function and of the expression of motion sickness wre reviewed. Emphasis was given to the elucidation of the neuropharmacological mechanisms underlying the effects of scopolamine and amphetamine on motion sickness. Characterization of the ascending reticular activating system and the limbic system provided clues to the etiology of the side effects of scopolamine. The interrelationship between central cholinergic pathways and the peripheral (autonomic) expression of motion sickness was described. A correlation between the stress of excessive motion and a variety of hormonal responses to that stress was also detailed. The cholinergic system is involved in the efferent modulation of the vestibular hair cells, as an afferent modulator of the vestibular nuclei, in the activation of cortical and limbic structures, in the expression of motion sickness symptoms and most likely underscores a number of the hormonal changes that occur in stressful motion environments. The role of lecithin in the regulation of the levels of neurotransmitters was characterized as a possible means by which cholinergic neurochemistry can be modulated.

  18. Knowledge engineering approach to natural language understanding

    SciTech Connect

    Shapiro, S.C.; Neal, J.G.

    1982-01-01

    The authors describe the results of a preliminary study of a knowledge engineering approach to natural language understanding. A computer system is being developed to handle the acquisition, representation, and use of linguistic knowledge. The computer system is rule-based and utilizes a semantic network for knowledge storage and representation. In order to facilitate the interaction between user and system, input of linguistic knowledge and computer responses are in natural language. Knowledge of various types can be entered and utilized: syntactic and semantic; assertions and rules. The inference tracing facility is also being developed as a part of the rule-based system with output in natural language. A detailed example is presented to illustrate the current capabilities and features of the system. 12 references.

  19. General background and approach to multibody dynamics for space applications

    NASA Astrophysics Data System (ADS)

    Santini, Paolo; Gasbarri, Paolo

    2009-06-01

    Multibody dynamics for space applications is dictated by space environment such as space-varying gravity forces, orbital and attitude perturbations, control forces if any. Several methods and formulations devoted to the modeling of flexible bodies undergoing large overall motions were developed in recent years. Most of these different formulations were aimed to face one of the main problems concerning the analysis of spacecraft dynamics namely the reduction of computer simulation time. By virtue of this, the use of symbolic manipulation, recursive formulation and parallel processing algorithms were proposed. All these approaches fall into two categories, the one based on Newton/Euler methods and the one based on Lagrangian methods; both of them have their advantages and disadvantages although in general, Newtonian approaches lend to a better understanding of the physics of problems and in particular of the magnitude of the reactions and of the corresponding structural stresses. Another important issue which must be addressed carefully in multibody space dynamics is relevant to a correct choice of kinematics variables. In fact, when dealing with flexible multibody system the resulting equations include two different types of state variables, the ones associated with large (rigid) displacements and the ones associated with elastic deformations. These two sets of variables have generally two different time scales if we think of the attitude motion of a satellite whose period of oscillation, due to the gravity gradient effects, is of the same order of magnitude as the orbital period, which is much bigger than the one associated with the structural vibration of the satellite itself. Therefore, the numerical integration of the equations of the system represents a challenging problem. This was the abstract and some of the arguments that Professor Paolo Santini intended to present for the Breakwell Lecture; unfortunately a deadly disease attacked him and shortly took him

  20. Natural background concentrations and threshold values of chemical species for groundwater in Korea

    NASA Astrophysics Data System (ADS)

    Hyun, Y.; Lee, S.; Lee, H.

    2014-12-01

    We analyze natural background concentrations and determine threshold values of chemical species (NO3-N, Cl, As, Pb, Cr) for groundwater using Groundwater Quality Monitoring Network (GQMN) data operated by Korea Ministry of Environment (ME). GQMN data are divided into two groups, A and B. Group A consists of samples collected in aquifers where anthropogenic inputs are forced to be excluded by aquifer typology. Group B consists of samples in aquifers where purely anthropogenic chemicals (e.g., pesticide, PAC) are introduced at the downgradient. Group A is used to derive nationwide natural background concentrations for groundwater in specific aquifer geology under concern, which represents a reference system. Group B is used for deriving site-specific background concentrations for groundwater. For both groups of data, the samples with anthropogenic inputs are forced to be excluded, thus background concentrations are derived based on a pre-selection method accordingly. We determine threshold values according to EU GroundWater Daughter Directive(GWDD 2006/11/EC). For As, Pb, and Cr and some other trace elements, survival analyses are used for estimating background concentrations due to non-detect data. The results show that high concentration values of NO3-N and Cr are related to high natural background concentrations due to rock-water interactions for Group A. In particular, NO3-N concentrations vary with depth, which are consistent with natural attenuation processes. For Group B, some anthropogenic chemical species such as BTEX are observed and site-specific background concentrations of those elements are non-zero, which is apparently not naturally occurred at all. Natural background concentrations and threshold values derived from Group A can be used for setting up reference values for managing groundwater quality on a level of either domestic or drinking water stands. Meanwhile results from Group B provide a useful guidance for managing groundwater quality in

  1. Severe antenatally diagnosed renal disorders: background, prognosis and practical approach.

    PubMed

    Aulbert, Wiebke; Kemper, Markus J

    2016-04-01

    Nowadays most renal disorders, especially urinary tract malformations and renal cystic disease, are diagnosed antenatally. In cases of severe bilateral disease, intrauterine renal dysfunction may lead to renal oligohydramnios (ROH), resulting in pulmonary hypoplasia which affects perinatal mortality and morbidity as well as the long-term outcome. However, some infants may only have mild pulmonary and renal disease, and advances in postnatal and dialysis treatment have resulted in improved short- and long-term outcome even in those infants with severe ROH. Here, we review the current state of knowledge and clinical experience of patients presenting antenatally with severe bilateral renal disorders and ROH. By addressing underlying mechanisms, intrauterine tools of diagnosis and treatment as well as published outcome data, we hope to improve antenatal counselling and postnatal care. KEY SUMMARY POINTS: 1. Nowadays most renal disorders are diagnosed antenatally, especially urinary tract malformations and renal cystic disease. 2. Severe kidney dysfunction may lead to renal oligohydramnios, which can cause pulmonary hypoplasia and is a risk factor of perinatal mortality and postnatal renal outcome. However, as considerable clinical heterogeneity is present, outcome predictions need to be treated with caution. 3. Advances in postnatal and dialysis treatment have resulted in improved short- and long-term outcomes even in infants with severe renal oligohydramnios. 4. A multidisciplinary approach with specialist input is required when counselling a family with an ROH-affected fetus as the decision-making process is very challenging.

  2. Synthetic Biological Approaches to Natural Product Biosynthesis

    PubMed Central

    Winter, Jaclyn M; Tang, Yi

    2012-01-01

    Small molecules produced in Nature continue to be an inspiration for the development of new therapeutic agents. These natural products possess exquisite chemical diversity, which gives rise to their wide range of biological activities. In their host organism, natural products are assembled and modified by dedicated biosynthetic pathways that Nature has meticulously developed. Often times, the complex structures or chemical modifications instated by these pathways are difficult to replicate using traditional synthetic methods. An alternative approach for creating or enhancing the structural variation of natural products is through combinatorial biosynthesis. By rationally reprogramming and manipulating the biosynthetic machinery responsible for their production, unnatural metabolites that were otherwise inaccessible can be obtained. Additionally, new chemical structures can be synthesized or derivatized by developing the enzymes that carry out these complicated chemical reactions into biocatalysts. In this review, we will discuss a variety of combinatorial biosynthetic strategies, their technical challenges, and highlight some recent (since 2007) examples of rationally designed unnatural metabolites, as well as platforms that have been established for the production and modification of clinically important pharmaceutical compounds. PMID:22221832

  3. Computational Assessment of Naturally Occurring Neutron and Photon Background Radiation Produced by Extraterrestrial Sources

    DOE PAGES

    Miller, Thomas Martin; de Wet, Wouter C.; Patton, Bruce W.

    2015-10-28

    In this study, a computational assessment of the variation in terrestrial neutron and photon background from extraterrestrial sources is presented. The motivation of this assessment is to evaluate the practicality of developing a tool or database to estimate background in real time (or near–real time) during an experimental measurement or to even predict the background for future measurements. The extraterrestrial source focused on during this assessment is naturally occurring galactic cosmic rays (GCRs). The MCNP6 transport code was used to perform the computational assessment. However, the GCR source available in MCNP6 was not used. Rather, models developed and maintained bymore » NASA were used to generate the GCR sources. The largest variation in both neutron and photon background spectra was found to be caused by changes in elevation on Earth's surface, which can be as large as an order of magnitude. All other perturbations produced background variations on the order of a factor of 3 or less. The most interesting finding was that ~80% and 50% of terrestrial background neutrons and photons, respectively, are generated by interactions in Earth's surface and other naturally occurring and man-made objects near a detector of particles from extraterrestrial sources and their progeny created in Earth's atmosphere. In conclusion, this assessment shows that it will be difficult to estimate the terrestrial background from extraterrestrial sources without a good understanding of a detector's surroundings. Therefore, estimating or predicting background during a measurement environment like a mobile random search will be difficult.« less

  4. Assessing Natural Background Levels of aquifers in the Metropolitan Area of Milan (Lombardy)

    NASA Astrophysics Data System (ADS)

    De Caro, Mattia; Crosta, Giovanni; Frattini, Paolo

    2016-04-01

    The European Water Framework Directive (WFD 2000/60/CE) requires Member States to evaluate the status of groundwater bodies in order to reach a good water quality for human consumption. One of the preliminary steps for defining the status of groundwater bodies consists in the definition and evaluation of the so-called Natural Background Levels (NBL). The NBL or Baseline level can be defined as "the range of concentration of a given element, isotope or chemical compound in solution, derived entirely from natural, geological, biological or atmospheric sources, under conditions not perturbed by anthropogenic activity" (Edmund and Shand, 2009). The qualitative analysis for a large area (ca 4500 Km2) of the Po Plain around the Milan Metropolitan area (Lombardy, Italy) is presented in this study. Despite the aquifers in the Milan metropolitan area are an incredible groundwater resource for a very large population (3.195.629 inhabitants in the metropolitan area, data at November 2014) and a highly industrialized area, a groundwater baseline characterization is still missing. In order to attain the hydro-geochemical characterization a complete geodatabase was built (120.655 chemical samples from 1980 to 2014). This database has been explored by classical and multivariate statistical analyses to provide relationships among the more influential lithological, hydrogeological and hydro-chemical variables. Finally, the NBLs of different chemical species which may be anthropogenic sensitive (Na, Cl, K, NO3, SO4, NH4, As, Fe, Cr, Fe, Mn, Zn) and for multiple aquifer bodies (phreatic, semi-confined and confined aquifer) are evaluated. Two different approaches are applied: the Pre-Selection method (BRIDGE, 2006) and the Component-Separation method. The first one (PS) consists in the exclusion of samples from the available dataset that could indicate human activities then deriving the NBL as the 90th percentile of the remaining data. The second one (CS) consists in the fitting of

  5. Background in the context of land contaminated with naturally occurring radioactive material.

    PubMed

    Read, D; Read, G D; Thorne, M C

    2013-06-01

    The financial implications of choosing a particular threshold for clearance of radioactively contaminated land are substantial, particularly when one considers the volume of naturally occurring radioactive material (NORM) created each year by the production and combustion of fossil fuels and the exploitation of industrial minerals. Inevitably, a compromise needs to be reached between the level of environmental protection sought and the finite resources available for remediation. In the case of natural series radionuclides, any anthropogenic input is always superimposed on the inventory already present in the soil; this 'background' inventory is conventionally disregarded when assessing remediation targets. Unfortunately, the term is not well defined and the concept of 'background dose' is open to alternative interpretations. In this paper, we address the issue of natural background from a geochemical rather than from a solely radiological perspective, illustrating this with an example from the china clay industry. We propose a simple procedure for decision making based on activity concentrations of primordial radionuclides and their progeny. Subsequent calculations of dose need to take into account the mineralogical and chemical characteristics of the contamination, which in the case of NORM are invariably reflected in uranium series disequilibrium.

  6. natural background radiation dosimetry in the highest altitude region of Iran.

    PubMed

    Shahbazi-Gahrouei, Daryoush

    2003-09-01

    The natural background radiation has been measured in one of the highest altitude regions (Zagros Mountains), Chaharmahal and Bakhtiari province, in the south west of Iran. The outdoors-environmental monitoring exposure rate of radiation was measured in 200 randomly chosen regions using portable Geiger-Muller and scintillation detectors. Eight measurements were made in each region and an average value was used to calculate the exposure rate from natural background radiation. The average exposure rate was found to be 0.246 microGy/h and the annual average effective dose equivalent was found to be 0.49 mSv. An overall population-weighted mean outdoor dose rate was calculated to be 49 nGy/h, which is higher than the world-wide mean value of 44 nGy/h, as reported by UNSCEAR in 1998, and is comparable to the annual effective dose equivalent of 0.38 mSv. A good correlation between the altitude and the exposure rate was observed, as the higher altitude regions have higher natural background radiation levels.

  7. Simulating the Impact of the Natural Radiation Background on Bacterial Systems: Implications for Very Low Radiation Biological Experiments.

    PubMed

    Lampe, Nathanael; Biron, David G; Brown, Jeremy M C; Incerti, Sébastien; Marin, Pierre; Maigne, Lydia; Sarramia, David; Seznec, Hervé; Breton, Vincent

    2016-01-01

    At very low radiation dose rates, the effects of energy depositions in cells by ionizing radiation is best understood stochastically, as ionizing particles deposit energy along tracks separated by distances often much larger than the size of cells. We present a thorough analysis of the stochastic impact of the natural radiative background on cells, focusing our attention on E. coli grown as part of a long term evolution experiment in both underground and surface laboratories. The chance per day that a particle track interacts with a cell in the surface laboratory was found to be 6 × 10-5 day-1, 100 times less than the expected daily mutation rate for E. coli under our experimental conditions. In order for the chance cells are hit to approach the mutation rate, a gamma background dose rate of 20 μGy hr-1 is predicted to be required.

  8. Simulating the Impact of the Natural Radiation Background on Bacterial Systems: Implications for Very Low Radiation Biological Experiments

    PubMed Central

    Lampe, Nathanael; Biron, David G.; Brown, Jeremy M. C.; Incerti, Sébastien; Marin, Pierre; Maigne, Lydia; Sarramia, David; Seznec, Hervé; Breton, Vincent

    2016-01-01

    At very low radiation dose rates, the effects of energy depositions in cells by ionizing radiation is best understood stochastically, as ionizing particles deposit energy along tracks separated by distances often much larger than the size of cells. We present a thorough analysis of the stochastic impact of the natural radiative background on cells, focusing our attention on E. coli grown as part of a long term evolution experiment in both underground and surface laboratories. The chance per day that a particle track interacts with a cell in the surface laboratory was found to be 6 × 10−5 day−1, 100 times less than the expected daily mutation rate for E. coli under our experimental conditions. In order for the chance cells are hit to approach the mutation rate, a gamma background dose rate of 20 μGy hr−1 is predicted to be required. PMID:27851794

  9. Review of approaches to the recording of background lesions in toxicologic pathology studies in rats.

    PubMed

    McInnes, E F; Scudamore, C L

    2014-08-17

    Pathological evaluation of lesions caused directly by xenobiotic treatment must always take into account the recognition of background (incidental) findings. Background lesions can be congenital or hereditary, histological variations, changes related to trauma or normal aging and physiologic or hormonal changes. This review focuses on the importance and correct approach to recording of background changes and includes discussion on sources of variability in background changes, the correct use of terminology, the concept of thresholds, historical control data, diagnostic drift, blind reading of slides, scoring and artifacts. The review is illustrated with background lesions in Sprague Dawley and Wistar rats.

  10. Object detection in natural backgrounds predicted by discrimination performance and models

    NASA Technical Reports Server (NTRS)

    Rohaly, A. M.; Ahumada, A. J. Jr; Watson, A. B.

    1997-01-01

    Many models of visual performance predict image discriminability, the visibility of the difference between a pair of images. We compared the ability of three image discrimination models to predict the detectability of objects embedded in natural backgrounds. The three models were: a multiple channel Cortex transform model with within-channel masking; a single channel contrast sensitivity filter model; and a digital image difference metric. Each model used a Minkowski distance metric (generalized vector magnitude) to summate absolute differences between the background and object plus background images. For each model, this summation was implemented with three different exponents: 2, 4 and infinity. In addition, each combination of model and summation exponent was implemented with and without a simple contrast gain factor. The model outputs were compared to measures of object detectability obtained from 19 observers. Among the models without the contrast gain factor, the multiple channel model with a summation exponent of 4 performed best, predicting the pattern of observer d's with an RMS error of 2.3 dB. The contrast gain factor improved the predictions of all three models for all three exponents. With the factor, the best exponent was 4 for all three models, and their prediction errors were near 1 dB. These results demonstrate that image discrimination models can predict the relative detectability of objects in natural scenes.

  11. Object Detection in Natural Backgrounds Predicted by Discrimination Performance and Models

    NASA Technical Reports Server (NTRS)

    Ahumada, A. J., Jr.; Watson, A. B.; Rohaly, A. M.; Null, Cynthia H. (Technical Monitor)

    1995-01-01

    In object detection, an observer looks for an object class member in a set of backgrounds. In discrimination, an observer tries to distinguish two images. Discrimination models predict the probability that an observer detects a difference between two images. We compare object detection and image discrimination with the same stimuli by: (1) making stimulus pairs of the same background with and without the target object and (2) either giving many consecutive trials with the same background (discrimination) or intermixing the stimuli (object detection). Six images of a vehicle in a natural setting were altered to remove the vehicle and mixed with the original image in various proportions. Detection observers rated the images for vehicle presence. Discrimination observers rated the images for any difference from the background image. Estimated detectabilities of the vehicles were found by maximizing the likelihood of a Thurstone category scaling model. The pattern of estimated detectabilities is similar for discrimination and object detection, and is accurately predicted by a Cortex Transform discrimination model. Predictions of a Contrast- Sensitivity- Function filter model and a Root-Mean-Square difference metric based on the digital image values are less accurate. The discrimination detectabilities averaged about twice those of object detection.

  12. Natural inflation: consistency with cosmic microwave background observations of Planck and BICEP2

    SciTech Connect

    Freese, Katherine; Kinney, William H. E-mail: whkinney@buffalo.edu

    2015-03-01

    Natural inflation is a good fit to all cosmic microwave background (CMB) data and may be the correct description of an early inflationary expansion of the Universe. The large angular scale CMB polarization experiment BICEP2 has announced a major discovery, which can be explained as the gravitational wave signature of inflation, at a level that matches predictions by natural inflation models. The natural inflation (NI) potential is theoretically exceptionally well motivated in that it is naturally flat due to shift symmetries, and in the simplest version takes the form V(φ) = Λ{sup 4} [1 ± cos(Nφ/f)]. A tensor-to-scalar ratio r > 0.1 as seen by BICEP2 requires the height of any inflationary potential to be comparable to the scale of grand unification and the width to be comparable to the Planck scale. The Cosine Natural Inflation model agrees with all cosmic microwave background measurements as long as f ≥ m{sub Pl} (where m{sub Pl} = 1.22 × 10{sup 19} GeV) and Λ ∼ m{sub GUT} ∼ 10{sup 16} GeV. This paper also discusses other variants of the natural inflation scenario: we show that axion monodromy with potential V∝ φ{sup 2/3} is inconsistent with the BICEP2 limits at the 95% confidence level, and low-scale inflation is strongly ruled out. Linear potentials V ∝ φ are inconsistent with the BICEP2 limit at the 95% confidence level, but are marginally consistent with a joint Planck/BICEP2 limit at 95%. We discuss the pseudo-Nambu Goldstone model proposed by Kinney and Mahanthappa as a concrete realization of low-scale inflation. While the low-scale limit of the model is inconsistent with the data, the large-field limit of the model is marginally consistent with BICEP2. All of the models considered predict negligible running of the scalar spectral index, and would be ruled out by a detection of running.

  13. Technical note: An improved approach to determining background aerosol concentrations with PILS sampling on aircraft

    NASA Astrophysics Data System (ADS)

    Fukami, Christine S.; Sullivan, Amy P.; Ryan Fulgham, S.; Murschell, Trey; Borch, Thomas; Smith, James N.; Farmer, Delphine K.

    2016-07-01

    Particle-into-Liquid Samplers (PILS) have become a standard aerosol collection technique, and are widely used in both ground and aircraft measurements in conjunction with off-line ion chromatography (IC) measurements. Accurate and precise background samples are essential to account for gas-phase components not efficiently removed and any interference in the instrument lines, collection vials or off-line analysis procedures. For aircraft sampling with PILS, backgrounds are typically taken with in-line filters to remove particles prior to sample collection once or twice per flight with more numerous backgrounds taken on the ground. Here, we use data collected during the Front Range Air Pollution and Photochemistry Éxperiment (FRAPPÉ) to demonstrate that not only are multiple background filter samples are essential to attain a representative background, but that the chemical background signals do not follow the Gaussian statistics typically assumed. Instead, the background signals for all chemical components analyzed from 137 background samples (taken from ∼78 total sampling hours over 18 flights) follow a log-normal distribution, meaning that the typical approaches of averaging background samples and/or assuming a Gaussian distribution cause an over-estimation of background samples - and thus an underestimation of sample concentrations. Our approach of deriving backgrounds from the peak of the log-normal distribution results in detection limits of 0.25, 0.32, 3.9, 0.17, 0.75 and 0.57 μg m-3 for sub-micron aerosol nitrate (NO3-), nitrite (NO2-), ammonium (NH4+), sulfate (SO42-), potassium (K+) and calcium (Ca2+), respectively. The difference in backgrounds calculated from assuming a Gaussian distribution versus a log-normal distribution were most extreme for NH4+, resulting in a background that was 1.58× that determined from fitting a log-normal distribution.

  14. Disruptive camouflage tricks the human eye: a study of detection times of two near-similar targets in natural backgrounds

    NASA Astrophysics Data System (ADS)

    Selj, Gorm K.

    2015-10-01

    Our understanding of camouflage, in military as well as in evolutionary perspectives, has been developing over the last 100 years. In that period of time several underlying principles have emerged. It has turned out in the recent decade that background pattern matching alone may not be sufficient to conceal targets because of the ubiquitous and revealing information contained by the edges of a target. In this paper we have studied one concealment strategy, the so-called disruptive coloration, further as it predicts that high contrast patches placed at the target's outline will impede detection, by creating false target edges when exposed to the observer. Such disruptive coloration is contra-intuitive as it may impede detection in spite of the fact that the patches themselves may be poorly concealed. In military environments the "disruptive approach" within camouflage has been textbook material for decades. Still, very little has been reported, supporting this idea, especially when it comes to the concealment of human targets in natural sceneries. We report here experimental evidence from a field study, containing detection data from 12 unique natural scenes (5 testing the disruptive effect, 7 as reference tests), with both human targets and human observers, showing that disruptively colored camouflage patches along a human's outline (its head) may increase detection time significantly as when compared to a similar (human) target concealed only with background matching. Hence, our results support the idea that disruptive coloration may impede detection and similarly that the best concealment is achieved when disruptive coloration is added to a target that matches the background (reasonably) well. This study raises important question to the current understanding of human vision and concealment as well as to any approach to describe the human visual system mathematically.

  15. Natural 'background' soil water repellency in conifer forests: its prediction and relationship to wildfire occurrence

    NASA Astrophysics Data System (ADS)

    Doerr, Stefan; Woods, Scott; Martin, Deborah; Casimiro, Marta

    2013-04-01

    Soils under a wide range of vegetation types exhibit water repellency following the passage of a fire. This is viewed by many as one of the main causes for accelerated post-fire runoff and soil erosion and it has often been assumed that strong soil water repellency present after wildfire is fire-induced. However, high levels of repellency have also been reported under vegetation types not affected by fire, and the question arises to what degree the water repellency observed at burnt sites actually results from fire. This study aimed at determining 'natural background' water repellency in common coniferous forest types in the north-western USA. Mature or semi-mature coniferous forest sites (n = 81), which showed no evidence of recent fires and had at least some needle cast cover, were sampled across six states. After careful removal of litter and duff at each site, soil water repellency was examined in situ at the mineral soil surface using the Water Drop Penetration Time (WDPT) method for three sub-sites, followed by col- lecting near-surface mineral soil layer samples (0-3 cm depth). Following air-drying, samples were fur- ther analyzed for repellency using WDPT and contact angle (hsl) measurements. Amongst other variables examined were dominant tree type, ground vegetation, litter and duff layer depth, slope angle and aspect, elevation, geology, and soil texture, organic carbon content and pH. 'Natural background' water repellency (WDPT > 5 s) was detected in situ and on air-dry samples at 75% of all sites examined irrespective of dominant tree species (Pinus ponderosa, Pinus contorta, Picea engelma- nii and Pseudotsuga menziesii). These findings demonstrate that the soil water repellency commonly observed in these forest types following burning is not necessarily the result of recent fire but can instead be a natural characteristic. The notion of a low background water repellency being typical for long- unburnt conifer forest soils of the north-western USA is

  16. Dual approach for automated sleep spindles detection within EEG background activity in infant polysomnograms.

    PubMed

    Held, Claudio M; Causa, Leonardo; Estévez, Pablo; Pérez, Claudio; Garrido, Marcelo; Algarín, Cecilia; Peirano, Patricio

    2004-01-01

    An automated system for sleep spindles detection within EEG background activity, combining two different approaches, is presented. The first approach applies detection criteria on the sigma-band filtered EEG signal, including fuzzy thresholds. The second approach mimics an expert's procedure. A sleep spindle detection is validated if both approaches agree. The method was applied on a testing set, consisting of continuous sleep recordings of two patients, totaling 1132 epochs (pages). A total of 803 sleep spindles events were marked by the experts. Results showed an 87.7% agreement between the detection system and the medical experts.

  17. Activating Student Background Knowledge in a Take Charge Approach to Foreign Language Reading.

    ERIC Educational Resources Information Center

    Young, Dolly Jesusita

    A guide for teachers of second language reading offers ideas for using authentic texts as instructional materials. The guide focuses on how to teach students to become strategic readers and use their background knowledge to enhance comprehension. Schema theory is proposed as a framework for approaching reading tasks, by providing relevant pre- and…

  18. Molecular Mechanisms of Drug Resistance in Natural Leishmania Populations Vary with Genetic Background

    PubMed Central

    Decuypere, Saskia; Vanaerschot, Manu; Brunker, Kirstyn; Imamura, Hideo; Müller, Sylke; Khanal, Basudha; Rijal, Suman; Dujardin, Jean-Claude; Coombs, Graham H.

    2012-01-01

    The evolution of drug-resistance in pathogens is a major global health threat. Elucidating the molecular basis of pathogen drug-resistance has been the focus of many studies but rarely is it known whether a drug-resistance mechanism identified is universal for the studied pathogen; it has seldom been clarified whether drug-resistance mechanisms vary with the pathogen's genotype. Nevertheless this is of critical importance in gaining an understanding of the complexity of this global threat and in underpinning epidemiological surveillance of pathogen drug resistance in the field. This study aimed to assess the molecular and phenotypic heterogeneity that emerges in natural parasite populations under drug treatment pressure. We studied lines of the protozoan parasite Leishmania (L.) donovani with differential susceptibility to antimonial drugs; the lines being derived from clinical isolates belonging to two distinct genetic populations that circulate in the leishmaniasis endemic region of Nepal. Parasite pathways known to be affected by antimonial drugs were characterised on five experimental levels in the lines of the two populations. Characterisation of DNA sequence, gene expression, protein expression and thiol levels revealed a number of molecular features that mark antimonial-resistant parasites in only one of the two populations studied. A final series of in vitro stress phenotyping experiments confirmed this heterogeneity amongst drug-resistant parasites from the two populations. These data provide evidence that the molecular changes associated with antimonial-resistance in natural Leishmania populations depend on the genetic background of the Leishmania population, which has resulted in a divergent set of resistance markers in the Leishmania populations. This heterogeneity of parasite adaptations provides severe challenges for the control of drug resistance in the field and the design of molecular surveillance tools for widespread applicability. PMID:22389733

  19. Computational approaches to natural product discovery

    PubMed Central

    Medema, Marnix H.; Fischbach, Michael A.

    2016-01-01

    From the earliest Streptomyces genome sequences, the promise of natural product genome mining has been captivating: genomics and bioinformatics would transform compound discovery from an ad hoc pursuit to a high-throughput endeavor. Until recently, however, genome mining has advanced natural product discovery only modestly. Here, we argue that the development of algorithms to mine the continuously increasing amounts of (meta)genomic data will enable the promise of genome mining to be realized. We review computational strategies that have been developed to identify biosynthetic gene clusters in genome sequences and predict the chemical structures of their products. We then discuss networking strategies that can systematize large volumes of genetic and chemical data, and connect genomic information to metabolomic and phenotypic data. Finally, we provide a vision of what natural product discovery might look like in the future, specifically considering long-standing questions in microbial ecology regarding the roles of metabolites in interspecies interactions. PMID:26284671

  20. Computational approaches to natural product discovery.

    PubMed

    Medema, Marnix H; Fischbach, Michael A

    2015-09-01

    Starting with the earliest Streptomyces genome sequences, the promise of natural product genome mining has been captivating: genomics and bioinformatics would transform compound discovery from an ad hoc pursuit to a high-throughput endeavor. Until recently, however, genome mining has advanced natural product discovery only modestly. Here, we argue that the development of algorithms to mine the continuously increasing amounts of (meta)genomic data will enable the promise of genome mining to be realized. We review computational strategies that have been developed to identify biosynthetic gene clusters in genome sequences and predict the chemical structures of their products. We then discuss networking strategies that can systematize large volumes of genetic and chemical data and connect genomic information to metabolomic and phenotypic data. Finally, we provide a vision of what natural product discovery might look like in the future, specifically considering longstanding questions in microbial ecology regarding the roles of metabolites in interspecies interactions.

  1. Estimating background-subtracted fluorescence transients in calcium imaging experiments: a quantitative approach.

    PubMed

    Joucla, Sébastien; Franconville, Romain; Pippow, Andreas; Kloppenburg, Peter; Pouzat, Christophe

    2013-08-01

    Calcium imaging has become a routine technique in neuroscience for subcellular to network level investigations. The fast progresses in the development of new indicators and imaging techniques call for dedicated reliable analysis methods. In particular, efficient and quantitative background fluorescence subtraction routines would be beneficial to most of the calcium imaging research field. A background-subtracted fluorescence transients estimation method that does not require any independent background measurement is therefore developed. This method is based on a fluorescence model fitted to single-trial data using a classical nonlinear regression approach. The model includes an appropriate probabilistic description of the acquisition system's noise leading to accurate confidence intervals on all quantities of interest (background fluorescence, normalized background-subtracted fluorescence time course) when background fluorescence is homogeneous. An automatic procedure detecting background inhomogeneities inside the region of interest is also developed and is shown to be efficient on simulated data. The implementation and performances of the proposed method on experimental recordings from the mouse hypothalamus are presented in details. This method, which applies to both single-cell and bulk-stained tissues recordings, should help improving the statistical comparison of fluorescence calcium signals between experiments and studies.

  2. Supercritical Fluid Chromatography--Theoretical Background and Applications on Natural Products.

    PubMed

    Hartmann, Anja; Ganzera, Markus

    2015-11-01

    The use of supercritical fluid chromatography for natural product analysis as well as underlying theoretical mechanisms and instrumental requirements are summarized in this review. A short introduction focusing on the historical development of this interesting separation technique is followed by remarks on the current instrumental design, also describing possible detection modes and useable stationary phases. The overview on relevant applications is grouped based on their basic intention, may it be (semi)preparative or purely analytical. They indicate that supercritical fluid chromatography is still primarily considered for the analysis of nonpolar analytes like carotenoids, fatty acids, or terpenes. The low polarity of supercritical carbon dioxide, which is used with modifiers almost exclusively as a mobile phase today, combined with high efficiency and fast separations might explain the popularity of supercritical fluid chromatography for the analysis of these compounds. Yet, it has been shown that more polar natural products (e.g., xanthones, flavonoids, alkaloids) are separable too, with the same (if not superior) selectivity and reproducibility than established approaches like HPLC or GC.

  3. Diffusion-assisted selective dynamical recoupling: A new approach to measure background gradients in magnetic resonance

    SciTech Connect

    Álvarez, Gonzalo A.; Shemesh, Noam; Frydman, Lucio

    2014-02-28

    Dynamical decoupling, a generalization of the original NMR spin-echo sequence, is becoming increasingly relevant as a tool for reducing decoherence in quantum systems. Such sequences apply non-equidistant refocusing pulses for optimizing the coupling between systems, and environmental fluctuations characterized by a given noise spectrum. One such sequence, dubbed Selective Dynamical Recoupling (SDR) [P. E. S. Smith, G. Bensky, G. A. Álvarez, G. Kurizki, and L. Frydman, Proc. Natl. Acad. Sci. 109, 5958 (2012)], allows one to coherently reintroduce diffusion decoherence effects driven by fluctuations arising from restricted molecular diffusion [G. A. Álvarez, N. Shemesh, and L. Frydman, Phys. Rev. Lett. 111, 080404 (2013)]. The fully-refocused, constant-time, and constant-number-of-pulses nature of SDR also allows one to filter out “intrinsic” T{sub 1} and T{sub 2} weightings, as well as pulse errors acting as additional sources of decoherence. This article explores such features when the fluctuations are now driven by unrestricted molecular diffusion. In particular, we show that diffusion-driven SDR can be exploited to investigate the decoherence arising from the frequency fluctuations imposed by internal gradients. As a result, SDR presents a unique way of probing and characterizing these internal magnetic fields, given an a priori known free diffusion coefficient. This has important implications in studies of structured systems, including porous media and live tissues, where the internal gradients may serve as fingerprints for the system's composition or structure. The principles of this method, along with full analytical solutions for the unrestricted diffusion-driven modulation of the SDR signal, are presented. The potential of this approach is demonstrated with the generation of a novel source of MRI contrast, based on the background gradients active in an ex vivo mouse brain. Additional features and limitations of this new method are discussed.

  4. Diffusion-assisted selective dynamical recoupling: A new approach to measure background gradients in magnetic resonance

    NASA Astrophysics Data System (ADS)

    Álvarez, Gonzalo A.; Shemesh, Noam; Frydman, Lucio

    2014-02-01

    Dynamical decoupling, a generalization of the original NMR spin-echo sequence, is becoming increasingly relevant as a tool for reducing decoherence in quantum systems. Such sequences apply non-equidistant refocusing pulses for optimizing the coupling between systems, and environmental fluctuations characterized by a given noise spectrum. One such sequence, dubbed Selective Dynamical Recoupling (SDR) [P. E. S. Smith, G. Bensky, G. A. Álvarez, G. Kurizki, and L. Frydman, Proc. Natl. Acad. Sci. 109, 5958 (2012)], allows one to coherently reintroduce diffusion decoherence effects driven by fluctuations arising from restricted molecular diffusion [G. A. Álvarez, N. Shemesh, and L. Frydman, Phys. Rev. Lett. 111, 080404 (2013)]. The fully-refocused, constant-time, and constant-number-of-pulses nature of SDR also allows one to filter out "intrinsic" T1 and T2 weightings, as well as pulse errors acting as additional sources of decoherence. This article explores such features when the fluctuations are now driven by unrestricted molecular diffusion. In particular, we show that diffusion-driven SDR can be exploited to investigate the decoherence arising from the frequency fluctuations imposed by internal gradients. As a result, SDR presents a unique way of probing and characterizing these internal magnetic fields, given an a priori known free diffusion coefficient. This has important implications in studies of structured systems, including porous media and live tissues, where the internal gradients may serve as fingerprints for the system's composition or structure. The principles of this method, along with full analytical solutions for the unrestricted diffusion-driven modulation of the SDR signal, are presented. The potential of this approach is demonstrated with the generation of a novel source of MRI contrast, based on the background gradients active in an ex vivo mouse brain. Additional features and limitations of this new method are discussed.

  5. Doses and risks from uranium are not increased significantly by interactions with natural background photon radiation.

    PubMed

    Tanner, R J; Eakins, J S; Jansen, J T M; Harrison, J D

    2012-08-01

    The impact of depleted uranium (DU) on human health has been the subject of much conjecture. Both the chemical and radiological aspects of its behaviour in the human body have previously been investigated in detail, with the radiological impact being assumed to be linked to the alpha decay of uranium. More recently, it has been proposed that the accumulation in tissue of high-Z materials, such as DU, may give rise to enhanced local energy deposition in the presence of natural background photon radiation due to the high photoelectric interaction cross sections of high-Z atoms. It is speculated that, in addition to producing short-range photoelectrons, these events will be followed by intense Auger and Coster-Kronig electron emission, thereby causing levels of cell damage that are unaccounted for in conventional models of radiological risk. In this study, the physical and biological bases of these claims are investigated. The potential magnitudes of any effect are evaluated and discussed, and compared with the risks from other radiological or chemical hazards. Monte Carlo calculations are performed to estimate likely energy depositions due to the presence of uranium in human tissues in photon fields: whole body doses, organ doses in anthropomorphic phantoms and nano-/micro-dosimetric scenarios are each considered. The proposal is shown generally to be based on sound physics, but overall the impact on human health is expected to be negligible.

  6. Enhancement of natural background gamma-radiation dose around uranium microparticles in the human body.

    PubMed

    Pattison, John E; Hugtenburg, Richard P; Green, Stuart

    2010-04-06

    Ongoing controversy surrounds the adverse health effects of the use of depleted uranium (DU) munitions. The biological effects of gamma-radiation arise from the direct or indirect interaction between secondary electrons and the DNA of living cells. The probability of the absorption of X-rays and gamma-rays with energies below about 200 keV by particles of high atomic number is proportional to the third to fourth power of the atomic number. In such a case, the more heavily ionizing low-energy recoil electrons are preferentially produced; these cause dose enhancement in the immediate vicinity of the particles. It has been claimed that upon exposure to naturally occurring background gamma-radiation, particles of DU in the human body would produce dose enhancement by a factor of 500-1000, thereby contributing a significant radiation dose in addition to the dose received from the inherent radioactivity of the DU. In this study, we used the Monte Carlo code EGSnrc to accurately estimate the likely maximum dose enhancement arising from the presence of micrometre-sized uranium particles in the body. We found that although the dose enhancement is significant, of the order of 1-10, it is considerably smaller than that suggested previously.

  7. Enhancement of natural background gamma-radiation dose around uranium microparticles in the human body

    PubMed Central

    Pattison, John E.; Hugtenburg, Richard P.; Green, Stuart

    2010-01-01

    Ongoing controversy surrounds the adverse health effects of the use of depleted uranium (DU) munitions. The biological effects of gamma-radiation arise from the direct or indirect interaction between secondary electrons and the DNA of living cells. The probability of the absorption of X-rays and gamma-rays with energies below about 200 keV by particles of high atomic number is proportional to the third to fourth power of the atomic number. In such a case, the more heavily ionizing low-energy recoil electrons are preferentially produced; these cause dose enhancement in the immediate vicinity of the particles. It has been claimed that upon exposure to naturally occurring background gamma-radiation, particles of DU in the human body would produce dose enhancement by a factor of 500–1000, thereby contributing a significant radiation dose in addition to the dose received from the inherent radioactivity of the DU. In this study, we used the Monte Carlo code EGSnrc to accurately estimate the likely maximum dose enhancement arising from the presence of micrometre-sized uranium particles in the body. We found that although the dose enhancement is significant, of the order of 1–10, it is considerably smaller than that suggested previously. PMID:19776147

  8. A Natural Approach to the Number "e"

    ERIC Educational Resources Information Center

    Doerr, Helen M.; Meehan, Donna J.; O'Neil, AnnMarie H.

    2012-01-01

    In this article, the authors introduce the value of "e" by building on students' prior knowledge of slope and using their abilities to analyze, approximate, and interpret rates of change using graphs, symbols, and numerical data. This approach allows students to construct and interpret the value of "e" while laying the conceptual foundation for…

  9. Defining mental disorder. Exploring the 'natural function' approach

    PubMed Central

    2011-01-01

    Due to several socio-political factors, to many psychiatrists only a strictly objective definition of mental disorder, free of value components, seems really acceptable. In this paper, I will explore a variant of such an objectivist approach to defining metal disorder, natural function objectivism. Proponents of this approach make recourse to the notion of natural function in order to reach a value-free definition of mental disorder. The exploration of Christopher Boorse's 'biostatistical' account of natural function (1) will be followed an investigation of the 'hybrid naturalism' approach to natural functions by Jerome Wakefield (2). In the third part, I will explore two proposals that call into question the whole attempt to define mental disorder (3). I will conclude that while 'natural function objectivism' accounts fail to provide the backdrop for a reliable definition of mental disorder, there is no compelling reason to conclude that a definition cannot be achieved. PMID:21255405

  10. Defining mental disorder. Exploring the 'natural function' approach.

    PubMed

    Varga, Somogy

    2011-01-21

    Due to several socio-political factors, to many psychiatrists only a strictly objective definition of mental disorder, free of value components, seems really acceptable. In this paper, I will explore a variant of such an objectivist approach to defining metal disorder, natural function objectivism. Proponents of this approach make recourse to the notion of natural function in order to reach a value-free definition of mental disorder. The exploration of Christopher Boorse's 'biostatistical' account of natural function (1) will be followed an investigation of the 'hybrid naturalism' approach to natural functions by Jerome Wakefield (2). In the third part, I will explore two proposals that call into question the whole attempt to define mental disorder (3). I will conclude that while 'natural function objectivism' accounts fail to provide the backdrop for a reliable definition of mental disorder, there is no compelling reason to conclude that a definition cannot be achieved.

  11. Holistic approach for automated background EEG assessment in asphyxiated full-term infants

    NASA Astrophysics Data System (ADS)

    Matic, Vladimir; Cherian, Perumpillichira J.; Koolen, Ninah; Naulaers, Gunnar; Swarte, Renate M.; Govaert, Paul; Van Huffel, Sabine; De Vos, Maarten

    2014-12-01

    Objective. To develop an automated algorithm to quantify background EEG abnormalities in full-term neonates with hypoxic ischemic encephalopathy. Approach. The algorithm classifies 1 h of continuous neonatal EEG (cEEG) into a mild, moderate or severe background abnormality grade. These classes are well established in the literature and a clinical neurophysiologist labeled 272 1 h cEEG epochs selected from 34 neonates. The algorithm is based on adaptive EEG segmentation and mapping of the segments into the so-called segments’ feature space. Three features are suggested and further processing is obtained using a discretized three-dimensional distribution of the segments’ features represented as a 3-way data tensor. Further classification has been achieved using recently developed tensor decomposition/classification methods that reduce the size of the model and extract a significant and discriminative set of features. Main results. Effective parameterization of cEEG data has been achieved resulting in high classification accuracy (89%) to grade background EEG abnormalities. Significance. For the first time, the algorithm for the background EEG assessment has been validated on an extensive dataset which contained major artifacts and epileptic seizures. The demonstrated high robustness, while processing real-case EEGs, suggests that the algorithm can be used as an assistive tool to monitor the severity of hypoxic insults in newborns.

  12. Simple approach to predict APD/PMT lidar detector performance under sky background using dimensionless parametrization

    NASA Astrophysics Data System (ADS)

    Agishev, Ravil; Gross, Barry; Moshary, Fred; Gilerson, Alexander; Ahmed, Samir

    2006-08-01

    In this paper, we developed a simple approach to predict the APD/PMT (avalanche photodiode/photomultiplier) lidar detector performance in the presence of residual skylight background. By normalizing all relevant photodetector noise sources to the quantum noise, we obtain quantitative expressions for the degradation of the signal-to-noise ratio (SNR), the increasing threshold sensitivity of and decreasing lidar operation range. To apply the formalism to any lidar photodetectors operating in the ultra violet, visible and near-infrared spectral regions and to perform a comparative analysis of PMT and APD capabilities as the best photodetectors for ultra-violet (UV), visible (Vis) and near infra-red (NIR) lidar, we utilize a set of spectral characteristics that are built from an envelope of individual PMT and APD component responses. On this basis, the general analysis of system performance under intense background conditions is developed, and practical recommendations on detector use for each spectral region are given. The dimensionless formalism and the generalized detector spectral models used allows our analysis to be applied to nearly any lidar receiver operating over very different signal/background situations.

  13. Approaches to modelling uranium (VI) adsorption on natural mineral assemblages

    USGS Publications Warehouse

    Waite, T.D.; Davis, J.A.; Fenton, B.R.; Payne, T.E.

    2000-01-01

    Component additivity (CA) and generalised composite (GC) approaches to deriving a suitable surface complexation model for description of U(VI) adsorption to natural mineral assemblages are pursued in this paper with good success. A single, ferrihydrite-like component is found to reasonably describe uranyl uptake to a number of kaolinitic iron-rich natural substrates at pH > 4 in the CA approach with previously published information on nature of surface complexes, acid-base properties of surface sites and electrostatic effects used in the model. The GC approach, in which little pre-knowledge about generic surface sites is assumed, gives even better fits and would appear to be a method of particular strength for application in areas such as performance assessment provided the model is developed in a careful, stepwise manner with simplicity and goodness of fit as the major criteria for acceptance.

  14. Blurring the Inputs: A Natural Language Approach to Sensitivity Analysis

    NASA Technical Reports Server (NTRS)

    Kleb, William L.; Thompson, Richard A.; Johnston, Christopher O.

    2007-01-01

    To document model parameter uncertainties and to automate sensitivity analyses for numerical simulation codes, a natural-language-based method to specify tolerances has been developed. With this new method, uncertainties are expressed in a natural manner, i.e., as one would on an engineering drawing, namely, 5.25 +/- 0.01. This approach is robust and readily adapted to various application domains because it does not rely on parsing the particular structure of input file formats. Instead, tolerances of a standard format are added to existing fields within an input file. As a demonstration of the power of this simple, natural language approach, a Monte Carlo sensitivity analysis is performed for three disparate simulation codes: fluid dynamics (LAURA), radiation (HARA), and ablation (FIAT). Effort required to harness each code for sensitivity analysis was recorded to demonstrate the generality and flexibility of this new approach.

  15. Categorization of Natural Whistled Vowels by Naïve Listeners of Different Language Background

    PubMed Central

    Meyer, Julien; Dentel, Laure; Meunier, Fanny

    2017-01-01

    Whistled speech in a non-tonal language consists of the natural emulation of vocalic and consonantal qualities in a simple modulated whistled signal. This special speech register represents a natural telecommunication system that enables high levels of sentence intelligibility by trained speakers and is not directly intelligible to naïve listeners. Yet, it is easily learned by speakers of the language that is being whistled, as attested by the current efforts of the revitalization of whistled Spanish in the Canary Islands. To better understand the relation between whistled and spoken speech perception, we look herein at how Spanish, French, and Standard Chinese native speakers, knowing nothing about whistled speech, categorized four Spanish whistled vowels. The results show that the listeners categorized differently depending on their native language. The Standard Chinese speakers demonstrated the worst performance on this task but were still able to associate a tonal whistle to vowel categories. Spanish speakers were the most accurate, and both Spanish and French participants were able to categorize the four vowels, although not as accurately as an expert whistler. These results attest that whistled speech can be used as a natural laboratory to test the perceptual processes of language. PMID:28174545

  16. Categorization of Natural Whistled Vowels by Naïve Listeners of Different Language Background.

    PubMed

    Meyer, Julien; Dentel, Laure; Meunier, Fanny

    2017-01-01

    Whistled speech in a non-tonal language consists of the natural emulation of vocalic and consonantal qualities in a simple modulated whistled signal. This special speech register represents a natural telecommunication system that enables high levels of sentence intelligibility by trained speakers and is not directly intelligible to naïve listeners. Yet, it is easily learned by speakers of the language that is being whistled, as attested by the current efforts of the revitalization of whistled Spanish in the Canary Islands. To better understand the relation between whistled and spoken speech perception, we look herein at how Spanish, French, and Standard Chinese native speakers, knowing nothing about whistled speech, categorized four Spanish whistled vowels. The results show that the listeners categorized differently depending on their native language. The Standard Chinese speakers demonstrated the worst performance on this task but were still able to associate a tonal whistle to vowel categories. Spanish speakers were the most accurate, and both Spanish and French participants were able to categorize the four vowels, although not as accurately as an expert whistler. These results attest that whistled speech can be used as a natural laboratory to test the perceptual processes of language.

  17. A new line-of-sight approach to the non-linear Cosmic Microwave Background

    NASA Astrophysics Data System (ADS)

    Fidler, Christian; Koyama, Kazuya; Pettinari, Guido W.

    2015-04-01

    We develop the transport operator formalism, a new line-of-sight integration framework to calculate the anisotropies of the Cosmic Microwave Background (CMB) at the linear and non-linear level. This formalism utilises a transformation operator that removes all inhomogeneous propagation effects acting on the photon distribution function, thus achieving a split between perturbative collisional effects at recombination and non-perturbative line-of-sight effects at later times. The former can be computed in the framework of standard cosmological perturbation theory with a second-order Boltzmann code such as SONG, while the latter can be treated within a separate perturbative scheme allowing the use of non-linear Newtonian potentials. We thus provide a consistent framework to compute all physical effects contained in the Boltzmann equation and to combine the standard remapping approach with Boltzmann codes at any order in perturbation theory, without assuming that all sources are localised at recombination.

  18. U.S. -- EC fuel cycle study: Background document to the approach and issues

    SciTech Connect

    Cantor, Robin; Russell, Lee; Krupnick, Alan; Smith, Hilary; Schaffhauser, Jr., A.; Barnthouse, Larry; Cada, Glen; Kroodsma, Roger; Turner, Robb; Easterly, Clay; Jones, Troyce; Burtraw, Dallas; Harrington, Winston; Freeman, A. Myrick

    1992-11-01

    In February 1991, DOE and the Commission of the European Communities (EC), signed a joint statement regarding the external costs of fuel cycles. This 18-month agreement committed their respective organizations to develop a comparative analytical methodology and to develop the best range of estimates of external costs from secondary sources'' for eight fuel cycles and four conservation options. In our study, a fuel cycle is defined as the series of physical and chemical processes and activities that are required to generate electricity from a specific fuel or resource. This foundation phase of the study is primarily limited to developing and demonstrating methods for estimating impacts and their monetized value, what we term damages'' or benefits,'' leaving aside the extent to which such damages have been internalized. However, Appendix C provides the conceptual framework for evaluating the extent of internalization. This report is a background document to introduce the study approach and to discuss the major conceptual and practical issues entailed by the incremental damage problem. As a background document, the report seeks to communicate an overview of the study and the important methodological choices that were made to conduct the research. In successive sections of the report, the methodological tools used in the study are discussed; the ecological and health impacts are reviewed using the coal fuel cycle as a reference case; and, in the final chapter, the methods for valuing impacts are detailed.

  19. Cutaneous delivery of natural antioxidants: the enhancement approaches.

    PubMed

    Aljuffali, Ibrahim A; Hsu, Ching-Yun; Lin, Yin-Ku; Fang, Jia-You

    2015-01-01

    Topically applied natural antioxidants can be an effective treatment for inhibiting oxidative damage and photoaging of the skin. Due to the barrier function of the stratum corneum (SC), it is necessary to use an enhancement approach to promote the cutaneous absorption of natural antioxidants. Some factors that should be considered when developing delivery systems for natural antioxidants include increased solubility, enhanced storage stability, improved permeability and bioavailability, skin targeting, and minimal side effects. This review describes the skin delivery systems for natural antioxidant permeation that have been developed during the last decade. The antioxidants introduced include vitamins, polyphenols, and carotenoids. Various types of formulations are employed to improve the skin penetration of the antioxidants, such as hydrogels, cyclodextrin, microemulsions, nanoparticles, liposomes and niosomes. This review focuses on the introduction of natural antioxidants used in skin protection, the mechanisms of antioxidant activity on the skin, and formulation designs for enhancing absorption and efficacy.

  20. Natural hydrocarbon background in benthic sediments of Prince William Sound, Alaska: Oil vs coal

    USGS Publications Warehouse

    Short, J.W.; Kvenvolden, K.A.; Carlson, P.R.; Hostettler, F.D.; Rosenbauer, R.J.; Wright, B.A.

    1999-01-01

    The source of the background hydrocarbons in benthic sediments of Prince William Sound (PWS), AK, where the 1989 Exxon Valdez oil spill (EVOS) occurred, has been ascribed to oil seeps in coastal areas of the Gulf of Alaska (GOA). We present evidence that coal is a more plausible source, including (i) high concentrations of total PAH (TPAH), between 1670 and 3070 ng/g, in continental shelf sediments adjacent to the coastal region containing extensive coal deposits; (ii) PAH composition patterns of sediments along with predictive models that are consistent with coal but not oil; (iii) low ratios (<0.2) of triaromatic steranes to methylchrysenes found in sediments and coals, contrasting with the high ratios (11 and 13) found in seep oil; and (iv) bioaccumulation of PAH in salmon collected within 100 m of the Katalla oil seeps but not in filter-feeding mussels collected near oilfield drainages 9 km from the seeps, indicating negligible transport of bioavailable PAH from Katalla seeps to the GOA. In contrast with oil, PAH in coal are not bioavailable, so the presence of coal in these benthic sediments confers no adaptive benefit to biota of the marine ecosystem with respect to PAH insults from anthropogenic sources.The source of the background hydrocarbons in benthic sediments of Prince William Sound (PWS), AK, where the 1989 Exxon Valdez oil spill (EVOS) occurred, has been ascribed to oil seeps in coastal areas of the Gulf of Alaska (GOA). We present evidence that coal is a more plausible source, including (i) high concentrations of total PAH (TPAH), between 1670 and 3070 ng/g, in continental shelf sediments adjacent to the coastal region containing extensive coal deposits; (ii) PAH composition patterns of sediments along with predictive models that are consistent with coal but not oil; (iii) low ratios (<0.2) of triaromatic steranes to methylchrysenes found in sediments and coals, contrasting with the high ratios (11 and 13) found in seep oil; and (iv) bioaccumulation

  1. The Nature of the Unresolved Extragalactic Cosmic Soft X-Ray Background

    NASA Technical Reports Server (NTRS)

    Cappelluti, N.; Ranalli, P.; Roncarelli, M.; Arevalo, P.; Zamorani, G.; Comastri, A.; Gilli, R.; Rovilos, E.; Vignali, C.; Allevato, V.; Finoguenov, A.; Miyaji, T.; Nicastro, F.; Georgantopoulos, I.; Kashlinsky, A.

    2013-01-01

    In this paper we investigate the power spectrum of the unresolved 0.5-2 keV cosmic X-ray background (CXB) with deep Chandra 4-Msec (Ms) observations in the Chandra Deep Field South (CDFS). We measured a signal that, on scales >30 arcsec, is significantly higher than the shot noise and is increasing with angular scale. We interpreted this signal as the joint contribution of clustered undetected sources like active galactic nuclei (AGN), galaxies and the intergalactic medium (IGM). The power of unresolved cosmic source fluctuations accounts for approximately 12 per cent of the 0.5-2 keV extragalactic CXB. Overall, our modelling predicts that approximately 20 per cent of the unresolved CXB flux is produced by low-luminosity AGN, approximately 25 per cent by galaxies and approximately 55 per cent by the IGM. We do not find any direct evidence of the so-called 'warm hot intergalactic medium' (i.e. matter with 10(exp 5) less than T less than 10(exp 7) K and density contrast delta less than 1000), but we estimated that it could produce about 1/7 of the unresolved CXB. We placed an upper limit on the space density of postulated X-ray-emitting early black holes at z greater than 7.5 and compared it with supermassive black hole evolution models.

  2. Natural hydrocarbon background in benthic sediments of Prince William Sound, Alaska: Oil vs coal

    SciTech Connect

    Short, J.W.; Wright, B.A.; Kvenvolden, K.A.; Carlson, P.R.; Hostettler, F.D.; Rosenbauer, R.J.

    1999-01-01

    The source of the background hydrocarbons in benthic sediments of Prince William Sound (PWS), AK, where the 1989 Exxon Valdez oil spill (EVOS) occurred, has been ascribed to oil seeps in coastal areas of the Gulf of Alaska (GOA). The authors present evidence that coal is a more plausible source, including (i) high concentrations of total PAH (TPAH), between 1,670 and 3,070 ng/g, in continental shelf sediments adjacent to the coastal region containing extensive coal deposits; (ii) PAH composition patterns of sediments along with predictive models that are consistent with coal but not oil; (iii) low ratios of triaromatic steranes of methylchrysenes found in sediments and coals, contrasting with the high ratios found in seep oil; and (iv) bioaccumulation of PAH in salmon collected within 100 m of the Katalla oil seeps but not in filter-feeding mussels collected near oilfield drainages 9 km from the seeps, indicating negligible transport of bioavailable PAH from Katalla seeps to the GOA. In contrast with oil, PAH in coal are not bioavailable, so the presence of coal in these benthic sediments confers no adaptive benefit to biota of the marine ecosystem with respect to PAH insults from anthropogenic sources.

  3. Outdoor (222)Rn-concentrations in Germany - part 1 - natural background.

    PubMed

    Kümmel, M; Dushe, C; Müller, S; Gehrcke, K

    2014-06-01

    To determine the natural radiation exposure due to outdoor radon ((222)Rn) and its short-lived decay products in Germany, the Federal Office for Radiation Protection (BfS) conducted a measuring programme over three years. The annual mean radon concentration at 1.5 m above ground level was measured with solid-state track etch detectors at 173 measuring points in an even grid with a grid length of approx. 50 km. Furthermore, annual mean values of the equilibrium-equivalent radon concentration (EEC) and the equilibrium factor were estimated on the basis of the activity concentrations of (214)Pb and (214)Bi measured at 27 stations of the German Meteorological Service (DWD). Our study yielded a spatial mean outdoor radon concentration for Germany of 9 ± 1 Bq m(-3) (median: 8 (-0.5/+1.0) Bq m(-3)), with regional means varying from 4.5 Bq m(-3) in Hamburg to 14 Bq m(-3) in Bavaria. The determined EEC are in a range from 1.4 to 11 Bq m(-3).

  4. Patterns of population differentiation and natural selection on the celiac disease background risk network.

    PubMed

    Sams, Aaron; Hawks, John

    2013-01-01

    Celiac disease is a common small intestinal inflammatory condition induced by wheat gluten and related proteins from rye and barley. Left untreated, the clinical presentation of CD can include failure to thrive, malnutrition, and distension in juveniles. The disease can additionally lead to vitamin deficiencies, anemia, and osteoporosis. Therefore, CD potentially negatively affected fitness in past populations utilizing wheat, barley, and rye. Previous analyses of CD risk variants have uncovered evidence for positive selection on some of these loci. These studies also suggest the possibility that risk for common autoimmune conditions such as CD may be the result of positive selection on immune related loci in the genome to fight infection. Under this evolutionary scenario, disease phenotypes may be a trade-off from positive selection on immunity. If this hypothesis is generally true, we can expect to find a signal of natural selection when we survey across the network of loci known to influence CD risk. This study examines the non-HLA autosomal network of gene loci associated with CD risk in Europe. We reject the null hypothesis of neutrality on this network of CD risk loci. Additionally, we can localize evidence of selection in time and space by adding information from the genome of the Tyrolean Iceman. While we can show significant differentiation between continental regions across the CD network, the pattern of evidence is not consistent with primarily recent (Holocene) selection across this network in Europe. Further localization of ancient selection on this network may illuminate the ecological pressures acting on the immune system during this critically interesting phase of our evolution.

  5. The molecular through ecological genetics of abnormal abdomen in Drosophila mercatorum. V. Female phenotypic expression on natural genetic backgrounds and in natural environments.

    PubMed

    Templeton, A R; Hollocher, H; Johnston, J S

    1993-06-01

    The abnormal abdomen (aa) syndrome in Drosophila mercatorum depends on the presence of R1 inserts in a third or more of the X-linked 28S rDNA genes and the absence of selective underreplication of inserted repeats in polytene tissues that is controlled by an X-linked locus (ur) half a map unit from the rDNA complex. This syndrome affects both life history and morphology in the laboratory. Because abnormal morphologies are rarely encountered in nature, the purpose of this study is to see if the female life history traits are still affected under more natural genetic backgrounds and environmental conditions. Two outbred stocks were extracted from the natural population living near Kamuela, Hawaii: KaaX that has only X chromosomes with uraa alleles, and K+X that has only ur+ alleles. These two stocks have nonoverlapping distributions of insert proportions, indicating strong disequilibrium between the ur locus and the rDNA complex. The KaaX stock had almost no morphological penetrance of uraa, indicating that genetic background is important. KaaX expressed longer female egg-to-adult developmental times, increased early adult female fecundity, and decreased female adult longevity compared with K+X. By bagging natural rots of the cactus Opuntia megacantha near Kamuela, Hawaii, it was shown that egg-to-adult developmental time is slowed down by 0.92 days in females bearing uraa alleles in nature, with no detectable slowdown in uraa males. The bagged rot data also indicate that females bearing uraa alleles have a strong fecundity advantage in nature under some ecological conditions but not others.

  6. Natural background levels and threshold values of chemical species in three large-scale groundwater bodies in Northern Italy.

    PubMed

    Molinari, Antonio; Guadagnini, Laura; Marcaccio, Marco; Guadagnini, Alberto

    2012-05-15

    We analyze natural background levels (NBLs) and threshold values (TVs) of spatially distributed chemical species (NH(4), B and As) which may be a potential pressure and concern in three large scale alluvial and fluvio-deltaic aquifers at different depths of the Apennines and Po river plains in Emilia-Romagna, Northern Italy. Our results are based on statistical methodologies designed to separate the natural and anthropogenic contributions in monitored concentrations by modeling the empirical distribution of the detected concentration with a mixture of probability density functions. Available chemical observations are taken over a 20 years period and are associated with different depths and cover planar investigation scales of the order of hundreds of kilometers. High concentration values detected for NH(4) and B appear to be related to high natural background levels. Due to interaction with the host rock in different geochemical environments we observed that concentration vary in time and space (including in depth) consistently with the hydrogeochemical features and the occurrence of natural attenuation mechanisms in the analyzed reservoirs. Conversely, estimated As NBLs are not consistent with the conceptual model of the hydrogeochemical behavior of the systems analyzed and experimental evidences of As content in aquifer cores. This is due to the inability of these techniques to incorporate the complex dynamics of the processes associated with the specific hydrogeochemical setting. Statistical analyses performed upon aggregating the concentration data according to different time observation windows allow identifying temporal dynamics of NBLs and TVs of target compounds within the observation time frame. Our results highlight the benefit of a dynamic monitoring process and analysis of well demarcated groundwater bodies to update the associated NBLs as a function of the temporal dependence of natural processes occurring in the subsurface. Monitoring protocols could

  7. Drug development from natural resource: a systematic approach.

    PubMed

    Sharma, S B; Gupta, Richa

    2015-01-01

    Modern research in drug discovery from medicinal plants involves a multidimensional approach combining botanical, phytochemical, biochemical combinatorial chemistry and bioassay-guided fractionation approaches. Natural sources continue to provide an alternative as pharmacological leads against various devastating diseases such as diabetes, CVD, cancer etc. Nowadays, there is enormous requirement of safe and effective drugs in the world. This has prompted scientists to revert back towards natural resources as a potential source of therapeutics for treatment and management of such chronic and fatal diseases. However, there are certain serious challenges and limitations in this field including scale up and commercialization of active compounds which allow only one in thousand lead molecules to be developed as drug. A systematic and scientific approach is an essential requirement for drug development from natural resource. This mini review provides an overview of the methods involved in natural product research starting from crude plant extract to bioactive pharmacological lead. Moreover, it also discusses the limitations of working concerning the bioactivity of medicinal plants.

  8. Quality assurance of temporal variability of natural decay chain and neutron induced background for low-level NORM analysis

    DOE PAGES

    Yoho, Michael; Porterfield, Donivan R.; Landsberger, Sheldon

    2015-09-22

    In this study, twenty-one high purity germanium (HPGe) background spectra were collected over 2 years at Los Alamos National Laboratory. A quality assurance methodology was developed to monitor spectral background levels from thermal and fast neutron flux levels and naturally occurring radioactive material decay series radionuclides. 238U decay products above 222Rn demonstrated minimal temporal variability beyond that expected from counting statistics. 238U and 232Th progeny below Rn gas displayed at most twice the expected variability. Further, an analysis of the 139 keV 74Ge(n, γ) and 691 keV 72Ge(n, n') spectral features demonstrated temporal stability for both thermal and fast neutronmore » fluxes.« less

  9. Quality assurance of temporal variability of natural decay chain and neutron induced background for low-level NORM analysis

    SciTech Connect

    Yoho, Michael; Porterfield, Donivan R.; Landsberger, Sheldon

    2015-09-22

    In this study, twenty-one high purity germanium (HPGe) background spectra were collected over 2 years at Los Alamos National Laboratory. A quality assurance methodology was developed to monitor spectral background levels from thermal and fast neutron flux levels and naturally occurring radioactive material decay series radionuclides. 238U decay products above 222Rn demonstrated minimal temporal variability beyond that expected from counting statistics. 238U and 232Th progeny below Rn gas displayed at most twice the expected variability. Further, an analysis of the 139 keV 74Ge(n, γ) and 691 keV 72Ge(n, n') spectral features demonstrated temporal stability for both thermal and fast neutron fluxes.

  10. Wind profiling for a coherent wind Doppler lidar by an auto-adaptive background subtraction approach.

    PubMed

    Wu, Yanwei; Guo, Pan; Chen, Siying; Chen, He; Zhang, Yinchao

    2017-04-01

    Auto-adaptive background subtraction (AABS) is proposed as a denoising method for data processing of the coherent Doppler lidar (CDL). The method is proposed specifically for a low-signal-to-noise-ratio regime, in which the drifting power spectral density of CDL data occurs. Unlike the periodogram maximum (PM) and adaptive iteratively reweighted penalized least squares (airPLS), the proposed method presents reliable peaks and is thus advantageous in identifying peak locations. According to the analysis results of simulated and actually measured data, the proposed method outperforms the airPLS method and the PM algorithm in the furthest detectable range. The proposed method improves the detection range approximately up to 16.7% and 40% when compared to the airPLS method and the PM method, respectively. It also has smaller mean wind velocity and standard error values than the airPLS and PM methods. The AABS approach improves the quality of Doppler shift estimates and can be applied to obtain the whole wind profiling by the CDL.

  11. Capitalizing on nature: how to implement an ecosystem approach.

    PubMed

    Holt, Alison R; Hattam, Caroline

    2009-10-23

    The Natural Capital Initiative (www.naturalcapitalinitiative.org.uk) held its first conference 'Valuing our life support systems' at Savoy Place, London, from 29 April to 1 May 2009. The aim of the conference was to discuss different perspectives on, and solutions to, the conservation and sustainable use of ecosystem services. It particularly focused on the link between the environment and the economy, and how to implement an ecosystem approach to environmental management. This event brought together scientists across the natural and social sciences, alongside representatives from government, non-governmental organizations, business and industry.

  12. Beryllium natural background concentration and mobility: a reappraisal examining the case of high Be-bearing pyroclastic rocks.

    PubMed

    Armiento, Giovanna; Bellatreccia, Fabio; Cremisini, Carlo; Della Ventura, Giancarlo; Nardi, Elisa; Pacifico, Renata

    2013-01-01

    Beryllium is widely distributed in soils at low levels, but it can also occur naturally in higher concentrations in a variety of materials exploited for many industrial applications. Beryllium is also one of the most toxic natural elements and is known to be a human carcinogen. A concise account of the literature data on baseline concentrations of Be in soils illustrates the possibility of worldwide presence of areas with a high natural background concentration of Be (up to 300 mg/kg), the crustal abundance of which is generally estimated to be in the range 2-6 mg/kg. Nevertheless, the number of available data is rather limited in comparison with those about other toxic elements such as Pb, Cd and Cr. This has probably caused the choice of low values of concentration level as the reference for the definition of soil contamination: these values are not always realistic and are not applicable to large areas. As a case study, we report and analyse a diffuse, unusually high (up to 80 mg/kg, average approximately 20 mg/kg), natural occurrence of beryllium in loose and poorly consolidated pyroclastic layers related to the Pleistocene activity of the Vico volcano. Additionally, the analysis of Be leachability has been carried out, providing evidence of a not negligible mobility in contrast with the scarce data presented in the literature that usually indicate beryllium as an element with low mobility in oxidising surface environmental conditions. This research marks the beginning of a possible reappraisal of beryllium geochemical behaviour and background levels, providing more realistic reference values for risk assessment and land management.

  13. Pharmacokinetic Modeling of Manganese III. Physiological Approaches Accounting for Background and Tracer Kinetics

    SciTech Connect

    Teeguarden, Justin G.; Gearhart, Jeffrey; Clewell, III, H. J.; Covington, Tammie R.; Nong, Andy; Anderson, Melvin E.

    2007-01-01

    Manganese (Mn) is an essential nutrient. Mn deficiency is associated with altered lipid (Kawano et al. 1987) and carbohydrate metabolism (Baly et al. 1984; Baly et al. 1985), abnormal skeletal cartilage development (Keen et al. 2000), decreased reproductive capacity, and brain dysfunction. Occupational and accidental inhalation exposures to aerosols containing high concentrations of Mn produce neurological symptoms with Parkinson-like characteristics in workers. At present, there is also concern about use of the manganese-containing compound, methylcyclopentadienyl manganese tricarbonyl (MMT), in unleaded gasoline as an octane enhancer. Combustion of MMT produces aerosols containing a mixture of manganese salts (Lynam et al. 1999). These Mn particulates may be inhaled at low concentrations by the general public in areas using MMT. Risk assessments for essential elements need to acknowledge that risks occur with either excesses or deficiencies and the presence of significant amounts of these nutrients in the body even in the absence of any exogenous exposures. With Mn there is an added complication, i.e., the primary risk is associated with inhalation while Mn is an essential dietary nutrient. Exposure standards for inhaled Mn will need to consider the substantial background uptake from normal ingestion. Andersen et al. (1999) suggested a generic approach for essential nutrient risk assessment. An acceptable exposure limit could be based on some ‘tolerable’ change in tissue concentration in normal and exposed individuals, i.e., a change somewhere from 10 to 25 % of the individual variation in tissue concentration seen in a large human population. A reliable multi-route, multi-species pharmacokinetic model would be necessary for the implementation of this type of dosimetry-based risk assessment approach for Mn. Physiologically-based pharmacokinetic (PBPK) models for various xenobiotics have proven valuable in contributing to a variety of chemical specific risk

  14. The proportion of childhood leukaemia incidence in Great Britain that may be caused by natural background ionizing radiation.

    PubMed

    Wakeford, R; Kendall, G M; Little, M P

    2009-04-01

    The aetiology of childhood leukaemia remains generally unknown, although exposure to moderate and high levels of ionizing radiation, such as those experienced during the atomic bombings of Japan or from radiotherapy, is an established cause. Risk models based primarily on studies of the Japanese atomic bomb survivors imply that low-level exposure to ionizing radiation, including ubiquitous natural background radiation, also raises the risk of childhood leukaemia. Using two sets of recently published leukaemia risk models and estimates of natural background radiation red-bone-marrow doses received by children, about 20% of the cases of childhood leukaemia in Great Britain are predicted to be attributable to this source. However, for one of these sets of risk models this attributable fraction is materially dependent on how the radiation-induced risk is assumed to be transferred between the Japanese atomic bomb survivors and Western children. Over a range of annual doses representing the range (0.5-2.5 mSv/year) experienced by most populations, the attributable proportion for the preferred risk-transfer model varies between 8 and 30%, with small deviations from a linear relationship that are largely due to the saturation of the model, although again this range of attributable fractions depends on the assumed transfer of risk between populations.

  15. Effects of Reduced Natural Background Radiation on Drosophila melanogaster Growth and Development as Revealed by the FLYINGLOW Program.

    PubMed

    Morciano, P; Iorio, R; Iovino, D; Cipressa, F; Esposito, G; Porrazzo, A; Satta, L; Alesse, E; Tabocchini, M A; Cenci, G

    2017-03-06

    Natural background radiation of Earth and cosmic rays played a relevant role during the evolution of living organisms. However, how chronic low doses of radiation can affect biological processes is still unclear. Previous data have indicated that cells grown at the Gran Sasso Underground Laboratory (LNGS, L'Aquila) of National Institute of Nuclear Physics (INFN) of Italy, where the dose rate of cosmic rays and neutrons is significantly reduced with respect to the external environment, elicited an impaired response against endogenous damage as compared to cells grown outside LNGS. This suggests that environmental radiation contributes to the development of defense mechanisms at cellular level. To further understand how environmental radiation affects metabolism of living organisms, we have recently launched the FLYINGLOW program that aims at exploiting Drosophila melanogaster as a model for evaluating the effects of low doses/dose rates of radiation at the organismal level. Here, we will present a comparative data set on lifespan, motility and fertility from different Drosophila strains grown in parallel at LNGS and in a reference laboratory at the University of L'Aquila. Our data suggest the reduced radiation environment can influence Drosophila development and, depending on the genetic background, may affect viability for several generations even when flies are moved back to normal background radiation. As flies are considered a valuable model for human biology, our results might shed some light on understanding the effect of low dose radiation also in humans. This article is protected by copyright. All rights reserved.

  16. A Coupled Human-Natural Systems Approach to Valuing Natural Capital

    NASA Astrophysics Data System (ADS)

    Fenichel, E. P.; Abbott, J.; Fujitani, M.

    2012-12-01

    The idea that geological and biological natural resources provide ecosystem services and that the physical geological and biological stocks, referred to as ecological stocks, are forms of capital is not new, but has attracted increased attention since the Millennium Ecosystem Assessment was released in 2005. Yet, the exact meaning of these terms, the connection between natural capital and ecosystem services, and the broader links between biophysical science and economics is often vague. The conceptual connection between ecosystem services and natural capital is that ecosystem services are the flow of goods and services that people receive from natural resources, and these flows are generated by an endowment of ecological stocks. While individuals derive benefits from a flow of services, the extent that people value the underlying natural capital asset depends on institutional arrangements in addition to the ecological properties of the stocks, because the value of capital relates to the future flow of services. A coupled human-natural systems modeling approach can help understand the value of natural capital in addition to helping scientist and policy makers better manage earth's resources. The value of a capital asset is the net present value of the flow of service, often calculated by the NPV rule. The NPV rule almost always assumes perfectly functioning markets for services and capital, but for many important ecosystem services such markets simply do not exist. The NPV rule can be derived by maximizing the net present value of capital. Indeed, the NPV rule comes from the adjoint condition of an optimal control problem where the flow of services from the capital asset are the benefits, and the dynamics of the capital stock are the constraints. Yet, trying to apply the traditional NPV rule to ecosystem services and natural capital can be frustrated by not knowing where pieces of the puzzle fit. We compare the standard NPV rule with a modified NPV rule derived by

  17. Resolving structural uncertainty in natural resources management using POMDP approaches

    USGS Publications Warehouse

    Williams, B.K.

    2011-01-01

    In recent years there has been a growing focus on the uncertainties of natural resources management, and the importance of accounting for uncertainty in assessing management effectiveness. This paper focuses on uncertainty in resource management in terms of discrete-state Markov decision processes (MDP) under structural uncertainty and partial observability. It describes the treatment of structural uncertainty with approaches developed for partially observable resource systems. In particular, I show how value iteration for partially observable MDPs (POMDP) can be extended to structurally uncertain MDPs. A key difference between these process classes is that structurally uncertain MDPs require the tracking of system state as well as a probability structure for the structure uncertainty, whereas with POMDPs require only a probability structure for the observation uncertainty. The added complexity of the optimization problem under structural uncertainty is compensated by reduced dimensionality in the search for optimal strategy. A solution algorithm for structurally uncertain processes is outlined for a simple example in conservation biology. By building on the conceptual framework developed for POMDPs, natural resource analysts and decision makers who confront structural uncertainties in natural resources can take advantage of the rapid growth in POMDP methods and approaches, and thereby produce better conservation strategies over a larger class of resource problems. ?? 2011.

  18. Rationale for a natural products approach to herbicide discovery.

    PubMed

    Dayan, Franck E; Owens, Daniel K; Duke, Stephen O

    2012-04-01

    Weeds continue to evolve resistance to all the known modes of herbicidal action, but no herbicide with a new target site has been commercialized in nearly 20 years. The so-called 'new chemistries' are simply molecules belonging to new chemical classes that have the same mechanisms of action as older herbicides (e.g. the protoporphyrinogen-oxidase-inhibiting pyrimidinedione saflufenacil or the very-long-chain fatty acid elongase targeting sulfonylisoxazoline herbicide pyroxasulfone). Therefore, the number of tools to manage weeds, and in particular those that can control herbicide-resistant weeds, is diminishing rapidly. There is an imminent need for truly innovative classes of herbicides that explore chemical spaces and interact with target sites not previously exploited by older active ingredients. This review proposes a rationale for a natural-products-centered approach to herbicide discovery that capitalizes on the structural diversity and ingenuity afforded by these biologically active compounds. The natural process of extended-throughput screening (high number of compounds tested on many potential target sites over long periods of times) that has shaped the evolution of natural products tends to generate molecules tailored to interact with specific target sites. As this review shows, there is generally little overlap between the mode of action of natural and synthetic phytotoxins, and more emphasis should be placed on applying methods that have proved beneficial to the pharmaceutical industry to solve problems in the agrochemical industry.

  19. A Systematic Approach to Discover and Characterize Natural Plant Biostimulants

    PubMed Central

    Povero, Giovanni; Mejia, Juan F.; Di Tommaso, Donata; Piaggesi, Alberto; Warrior, Prem

    2016-01-01

    The use of natural plant biostimulants is proposed as an innovative solution to address the challenges to sustainable agriculture, to ensure optimal nutrient uptake, crop yield, quality, and tolerance to abiotic stress. However, the process of selection and characterization of plant biostimulant matrices is complex and involves a series of rigorous evaluations customized to the needs of the plant. Here, we propose a highly differentiated plant biostimulant development and production platform, which involves a combination of technology, processes, and know-how. Chemistry, biology and omic concepts are combined/integrated to investigate and understand the specific mode(s) of action of bioactive ingredients. The proposed approach allows to predict and characterize the function of natural compounds as biostimulants. By managing and analyzing massive amounts of complex data, it is therefore possible to discover, evaluate and validate new product candidates, thus expanding the uses of existing products to meet the emerging needs of agriculture. PMID:27092156

  20. Approaches to metal speciation analysis in natural waters

    NASA Astrophysics Data System (ADS)

    Morrison, G. M. P.

    Approaches to the separation and identification of metal species in natural waters are discussed. Dissolved and colloidal metal species may be fractionated, on the basis of physico-chemical characteristics, by ion exchange, u.v. irradiation, resin adsorption, solvent extraction or strong acid digestion. Size fractionation techniques include filtration, centrifugation, dialysis, ultrafiltration and gel filtration chromatography. Suitable detection techniques, either before or after fractionation, are anodic stripping voltammetry, ion selective electrodes and atomic absorption. The bioavailable uptake rate of metal species may be determined by Dialysis with Receiving Resins.

  1. The interaction of natural background gamma radiation with depleted uranium micro-particles in the human body.

    PubMed

    Pattison, John E

    2013-03-01

    In this study, some characteristics of the photo-electrons produced when natural background gamma radiation interacts with micron-sized depleted uranium (DU) particles in the human body have been estimated using Monte Carlo simulations. In addition, an estimate has been made of the likelihood of radiological health effects occurring due to such an exposure. Upon exposure to naturally occurring background gamma radiation, DU particles in the body will produce an enhancement of the dose to the tissue in the immediate vicinity of the particles due to the photo-electric absorption of the radiation in the particle. In this study, the photo-electrons produced by a 10 μm-size particle embedded in tissue at the centre of the human torso have been investigated. The mean energies of the photo-electrons in the DU particle and in the two consecutive immediately surrounding 2 μm-wide tissue shells around the particle were found to be 38, 49 and 50 keV, respectively, with corresponding ranges of 1.3, 38 and 39 μm, respectively. The total photo-electron fluence-rates in the two consecutive 2 μm-wide tissue layers were found to be 14% and 7% of the fluence-rate in the DU particle, respectively. The estimated dose enhancement due to one 10 μm-sized DU particle in 1 cm(3) of tissue was less than 2 in 10 million of the dose received by the tissue without a particle being present. The increase in risk of death from cancer due to this effect is consequently insignificant.

  2. Inhibitory effect of natural organic matter or other background constituents on photocatalytic advanced oxidation processes: Mechanistic model development and validation.

    PubMed

    Brame, Jonathon; Long, Mingce; Li, Qilin; Alvarez, Pedro

    2015-11-01

    The ability of reactive oxygen species (ROS) to interact with priority pollutants is crucial for efficient water treatment by photocatalytic advanced oxidation processes (AOPs). However, background compounds in water such as natural organic matter (NOM) can significantly hinder targeted reactions and removal efficiency. This inhibition can be complex, interfering with degradation in solution and at the photocatalyst surface as well as hindering illumination efficiency and ROS production. We developed an analytical model to account for various inhibition mechanisms in catalytic AOPs, including competitive adsorption of inhibitors, scavenging of produced ROS at the surface and in solution, and the inner filtering of the excitation illumination, which combine to decrease ROS-mediated degradation. This model was validated with batch experiments using a variety of ROS producing systems (OH-generating TiO2 photocatalyst and H2O2-UV; (1)O2-generating photosensitive functionalized fullerenes and rose bengal) and inhibitory compounds (NOM, tert-butyl alcohol). Competitive adsorption by NOM and ROS scavenging were the most influential inhibitory mechanisms. Overall, this model enables accurate simulation of photocatalytic AOP performance when one or more inhibitory mechanisms are at work in a wide variety of application scenarios, and underscores the need to consider the effects of background constituents on degradation efficiency.

  3. Macondo oil in deep-sea sediments: Part 2 - Distribution and distinction from background and natural oil seeps.

    PubMed

    Stout, Scott A; Payne, James R; Ricker, Robert W; Baker, Gregory; Lewis, Christopher

    2016-10-15

    Following the Deepwater Horizon oil spill, the spilled Macondo oil was severely weathered during its transport within the deep-sea plume as discrete particles, which were subsequently deposited on the seafloor. The Macondo oil deposited in deep-sea sediments was distinguished from ambient (background) hydrocarbons and naturally-seeped and genetically-similar oils in the Mississippi Canyon region using a forensic method based upon a systematic, multi-year study of 724 deep-sea sediment cores collected in late 2010 and 2011. The method relied upon: (1) chemical fingerprinting of the distinct features of the wax-rich, severely-weathered Macondo oil; (2) hydrocarbon concentrations, considering a core's proximity to the Macondo well or to known or apparent natural oil seeps, and also vertically within a core; and (3) results from proximal cores and flocculent material from core supernatants and slurp gun filters. The results presented herein establish the geographic extent of "fingerprintable" Macondo oil recognized on the seafloor in 2010/2011.

  4. Does a Nurturing Approach That Uses an Outdoor Play Environment Build Resilience in Children from a Challenging Background?

    ERIC Educational Resources Information Center

    McArdle, Karen; Harrison, Terri; Harrison, Daniel

    2013-01-01

    Children from challenging backgrounds were brought to a woodland for a programme that sought to promote resilience at Camphill School. This qualitative study of one programme uses an ethnographic approach to research the effectiveness of this type of intervention. Case studies of three of the children are used to illustrate the ways in which…

  5. Preschool Teachers' Professional Background, Process Quality, and Job Attitudes: A Person-Centered Approach

    ERIC Educational Resources Information Center

    Jeon, Lieny; Buettner, Cynthia K.; Hur, Eunhye

    2016-01-01

    Research Findings: This exploratory study identified preschool teacher quality profiles in early childhood education settings using 9 indicators across teachers' professional background, observed process quality, and job attitudes toward teaching (e.g., job-related stress, satisfaction, and intention to leave the job). The sample consisted of 96…

  6. Activating Student Background Knowledge in a Take Charge Approach to Foreign Language Reading.

    ERIC Educational Resources Information Center

    Young, Dolly J.

    1991-01-01

    Addresses the immediate needs of language teachers who want to develop their students' reading skills but have not been provided with the instructional information necessary to do so. It suggests a methodological sequence for using the students' background knowledge and strategy training for foreign language reading using authentic texts. (33…

  7. Statistical Approach to Background Subtraction for Production of High-Quality Silhouettes for Human Gait Recognition

    DTIC Science & Technology

    2006-09-01

    and Little believe oscillations are the center of gait analysis . Thus frequency entrainment and phase locking are important in both model-free and...background scene from video containing a person walking. This data may be used in a variety of ways to perform continued gait analysis . This chapter...Jeffrey E. and James J. Little. “Phase Models in Gait Analysis ,” Exemplars versus Models Workshop Computer Vision and Pattern Recognition, Kauai, HI

  8. "Bundle Data" Approach at GES DISC Targeting Natural Hazards

    NASA Astrophysics Data System (ADS)

    Shie, C. L.; Shen, S.; Kempler, S. J.

    2015-12-01

    Severe natural phenomena such as hurricane, volcano, blizzard, flood and drought have the potential to cause immeasurable property damages, great socioeconomic impact, and tragic loss of human life. From searching to assessing the "Big", i.e., massive and heterogeneous scientific data (particularly, satellite and model products) in order to investigate those natural hazards, it has, however, become a daunting task for Earth scientists and applications researchers, especially during recent decades. The NASA Goddard Earth Sciences Data and Information Service Center (GES DISC) has served "Big" Earth science data, and the pertinent valuable information and services to the aforementioned users of diverse communities for years. In order to help and guide our users to online readily (i.e., with a minimum effort) acquire their requested data from our enormous resource at GES DISC for studying their targeted hazard/event, we have thus initiated a "Bundle Data" approach in 2014, first targeting the hurricane event/topic. We have recently worked on new topics such as volcano and blizzard. The "bundle data" of a specific hazard/event is basically a sophisticated integrated data package consisting of a series of proper datasets containing a group of relevant ("knowledge-based") data variables readily accessible to users via a system-prearranged table linking those data variables to the proper datasets (URLs). This online approach has been developed by utilizing a few existing data services such as Mirador as search engine; Giovanni for visualization; and OPeNDAP for data access, etc. The online "Data Cookbook" site at GES DISC is the current host for the "bundle data". We are now also planning on developing an "Automated Virtual Collection Framework" that shall eventually accommodate the "bundle data", as well as further improve our management in "Big Data".

  9. Bundle Data Approach at GES DISC Targeting Natural Hazards

    NASA Technical Reports Server (NTRS)

    Shie, Chung-Lin; Shen, Suhung; Kempler, Steven J.

    2015-01-01

    Severe natural phenomena such as hurricane, volcano, blizzard, flood and drought have the potential to cause immeasurable property damages, great socioeconomic impact, and tragic loss of human life. From searching to assessing the Big, i.e., massive and heterogeneous scientific data (particularly, satellite and model products) in order to investigate those natural hazards, it has, however, become a daunting task for Earth scientists and applications researchers, especially during recent decades. The NASA Goddard Earth Sciences Data and Information Service Center (GES DISC) has served Big Earth science data, and the pertinent valuable information and services to the aforementioned users of diverse communities for years. In order to help and guide our users to online readily (i.e., with a minimum effort) acquire their requested data from our enormous resource at GES DISC for studying their targeted hazard event, we have thus initiated a Bundle Data approach in 2014, first targeting the hurricane event topic. We have recently worked on new topics such as volcano and blizzard. The bundle data of a specific hazard event is basically a sophisticated integrated data package consisting of a series of proper datasets containing a group of relevant (knowledge--based) data variables readily accessible to users via a system-prearranged table linking those data variables to the proper datasets (URLs). This online approach has been developed by utilizing a few existing data services such as Mirador as search engine; Giovanni for visualization; and OPeNDAP for data access, etc. The online Data Cookbook site at GES DISC is the current host for the bundle data. We are now also planning on developing an Automated Virtual Collection Framework that shall eventually accommodate the bundle data, as well as further improve our management in Big Data.

  10. Design of natural food antioxidant ingredients through a chemometric approach.

    PubMed

    Mendiola, Jose A; Martín-Alvarez, Pedro J; Señoráns, F Javier; Reglero, Guillermo; Capodicasa, Alessandro; Nazzaro, Filomena; Sada, Alfonso; Cifuentes, Alejandro; Ibáñez, Elena

    2010-01-27

    In the present work, an environmentally friendly extraction process using subcritical conditions has been tested to obtain potential natural food ingredients from natural sources such as plants, fruits, spirulina, propolis, and tuber, with the scope of substituting synthetic antioxidants, which are subject to regulation restrictions and might be harmful for human health. A full characterization has been undertaken from the chemical and biochemical point of view to be able to understand their mechanism of action. Thus, an analytical method for profiling the compounds responsible for the antioxidant activity has been used, allowing the simultaneous determination of water-soluble vitamins, fat-soluble vitamins, phenolic compounds, carotenoids, and chlorophylls in a single run. This information has been integrated and analyzed using a chemometrical approach to correlate the bioactive compounds profile with the antioxidant activity and thus to be able to predict antioxidant activities of complex formulations. As a further step, a simplex centroid mixture design has been tested to find the optimal formulation and to calculate the effect of the interaction among individual extracts in the mixture.

  11. Subjective Measurement of Tactical Air Command and Control. Volume I. Background and Approach.

    DTIC Science & Technology

    1981-03-01

    77 09104 RAND CORP SANTA MONICA CA F/ 17/2SUBIJECTIVE MEASUREMENT OF TACTICAL AIR COMMAND AND CONTROL. VOL-ETC(U) UNL MAR 81 M CALLERO ,. NASLUNO, C...TACTICAL AIR COMMWI AND CGITOL--VOL. 1: BACKGROUND AND APPRAC Monti Callero , Willard Naslund, "-LI Clairice T. Veit March 1981 D ~MAY19. N- 1671/1-AF...ORG. REPORT NUMBER 7 AuTHOR(e) ., CONTRACT OR GRANT NUMBER(*) Monti Callero , Willard Naslund, Clairice T. Veit F49620-77-C-0023 9. PERFORMING

  12. Combining natural background levels (NBLs) assessment with indicator kriging analysis to improve groundwater quality data interpretation and management.

    PubMed

    Ducci, Daniela; de Melo, M Teresa Condesso; Preziosi, Elisabetta; Sellerino, Mariangela; Parrone, Daniele; Ribeiro, Luis

    2016-11-01

    The natural background level (NBL) concept is revisited and combined with indicator kriging method to analyze the spatial distribution of groundwater quality within a groundwater body (GWB). The aim is to provide a methodology to easily identify areas with the same probability of exceeding a given threshold (which may be a groundwater quality criteria, standards, or recommended limits for selected properties and constituents). Three case studies with different hydrogeological settings and located in two countries (Portugal and Italy) are used to derive NBL using the preselection method and validate the proposed methodology illustrating its main advantages over conventional statistical water quality analysis. Indicator kriging analysis was used to create probability maps of the three potential groundwater contaminants. The results clearly indicate the areas within a groundwater body that are potentially contaminated because the concentrations exceed the drinking water standards or even the local NBL, and cannot be justified by geogenic origin. The combined methodology developed facilitates the management of groundwater quality because it allows for the spatial interpretation of NBL values.

  13. TECHNIQUES AND APPROACHES TO EVALUATE THE NATURAL ATTENUATION OF MTBE

    EPA Science Inventory

    Natural anaerobic biodegradation is the most important processes controlling natural attenuation of MTBE along a flow path. However, natural biological degradation has been particularly difficult to document at field scale. Biodegradation of the BTEX compounds produce the same ...

  14. Does human activity impact the natural antibiotic resistance background? Abundance of antibiotic resistance genes in 21 Swiss lakes.

    PubMed

    Czekalski, Nadine; Sigdel, Radhika; Birtel, Julia; Matthews, Blake; Bürgmann, Helmut

    2015-08-01

    Antibiotic resistance genes (ARGs) are emerging environmental contaminants, known to be continuously discharged into the aquatic environment via human and animal waste. Freshwater aquatic environments represent potential reservoirs for ARG and potentially allow sewage-derived ARG to persist and spread in the environment. This may create increased opportunities for an eventual contact with, and gene transfer to, human and animal pathogens via the food chain or drinking water. However, assessment of this risk requires a better understanding of the level and variability of the natural resistance background and the extent of the human impact. We have analyzed water samples from 21 Swiss lakes, taken at sampling points that were not under the direct influence of local contamination sources and analyzed the relative abundance of ARG using quantitative real-time PCR. Copy numbers of genes mediating resistance to three different broad-spectrum antibiotic classes (sulfonamides: sul1, sul2, tetracyclines: tet(B), tet(M), tet(W) and fluoroquinolones: qnrA) were normalized to copy numbers of bacterial 16S rRNA genes. We used multiple linear regression to assess if ARG abundance is related to human activities in the catchment, microbial community composition and the eutrophication status of the lakes. Sul genes were detected in all sampled lakes, whereas only four lakes contained quantifiable numbers of tet genes, and qnrA remained below detection in all lakes. Our data indicate higher abundance of sul1 in lakes with increasing number and capacity of wastewater treatment plants (WWTPs) in the catchment. sul2 abundance was rather related to long water residence times and eutrophication status. Our study demonstrates the potential of freshwater lakes to preserve antibiotic resistance genes, and provides a reference for ARG abundance from lake systems with low human impact as a baseline for assessing ARG contamination in lake water.

  15. Embedded-explicit emergent literacy intervention I: Background and description of approach.

    PubMed

    Justice, Laura M; Kaderavek, Joan N

    2004-07-01

    This article, the first of a two-part series, provides background information and a general description of an emergent literacy intervention model for at-risk preschoolers and kindergartners. The embedded-explicit intervention model emphasizes the dual importance of providing young children with socially embedded opportunities for meaningful, naturalistic literacy experiences throughout the day, in addition to regular structured therapeutic interactions that explicitly target critical emergent literacy goals. The role of the speech-language pathologist (SLP) in the embedded-explicit model encompasses both indirect and direct service delivery: The SLP consults and collaborates with teachers and parents to ensure the highest quality and quantity of socially embedded literacy-focused experiences and serves as a direct provider of explicit interventions using structured curricula and/or lesson plans. The goal of this integrated model is to provide comprehensive emergent literacy interventions across a spectrum of early literacy skills to ensure the successful transition of at-risk children from prereaders to readers.

  16. Research on tracking approach to weak small targets under sky background

    NASA Astrophysics Data System (ADS)

    Chen, Jinling; Miao, Dong; Zhou, Wensheng; Shen, Jiarui; Chen, Nao; Kang, Bo

    2014-09-01

    The infrared (IR) target recognizing and tracking technique is widely applied to many fields such as industries, navigation, weapon controlling and guiding and so on. Its application in military field has become the research hotspot. The stability of target tracking is the most important in military applications. However, it is difficult to track the aerial target because of the complex background and noise interference, especially from long distance, which make tracking targets even harder. In this paper, a novel image tracking system is designed, which uses template matching algorithm combined with Kalman filter. Because of the noise in image, the presence of occlusion, and the deformation of tracked target, some tracking algorithms may fail. So it is the main idea in this paper to merge the advantages from the tracking algorithms, and track the target real time. The algorithm for weak small targets from the image is based on template matching algorithm. In order to overcome the problems related to the changes of unpredictable circumstance, Kalman filter tracking algorithm is used. For the disadvantage of template matching algorithm towards occasions in target tracking, such as target occlusion, drastic change of image intensity, the relevant solutions are proposed. In cases when the target is occluded or moves more than the operational limits of the tracking module, Kalman filter is used to predict the object location. Thus, automatic detection and tracking of target in real-time is achieved and the proposed method is more robust in target tracking. The results show that the algorithm can realize target tracking under complicated scenes. It also improves the tracking stability, capacity of anti-interfering and running efficiency.

  17. [Operative neurosurgery: personal view and historical backgrounds (3). Anterior circulation--pterional approach].

    PubMed

    Yonekawa, Yasuhiro

    2007-07-01

    Under the title of anterior circulation aneurysms and the pterional approach, followings are presented and emphasized along with mentioning their historical development in our present performance status. Pterional approach: head positioning with Mayfield-Kees fixation apparatus using one pin around the processus matoideus and the other 2 pins on the contralateral side behind the hair line the head turned 30 degrees and reclined chin-up l5-20 grade. Skin incision beginning just in front of the tragus ending up at the midline hair line in a curvilinear fashion always including the superficial temporal artery STA in its frontal branch and the facial nerve (frontal branch) in the skin flap. A muscle fascial preparation is so fashioned such that a strip of myofascial cuff is left at the linea temporalis and the temporal musculature is reflected and retracted towards the postero-basal direction in order to expose the pterion, for which a small short myofascial incision is added parallel to the skin incision towards the tragus up to several cm above it to prevent postoperative trismus. Bone flap is sawed out usually using three burr holes, at the key hole just at the proximal part of the linea temporalis, frontomedially on the squama frontalis and on the sutura squamosa, so that the Sylvian fissure and the superior temporal gyrus are exposed enough for further procedure. The sphenoid ridge is drilled away until the most lateral corner of the superior orbital fissure comes into view. Thus one has drilled away enough to do surgery in question at the skull base even at the time of "angry brain" due to subarachnoid hemorrhage SAH. This procedure can be followed by selective extradural anterior clinoidectomy SEAC in case of necessity. The dura is opened in a curvilinear fashion so that the dura can be reflected over the drilled sphenoid wing and so that the Sylvian fissure and the superior temporal gyrus is exposed for the treatment of aneurysms of the internal carotid artery

  18. Effect of the genetic background on recombination frequency in the cn-vg region of the second chromosome of natural populations of Drosophila melanogaster.

    PubMed

    Hofmanová, J

    1975-01-01

    Newly established test stocks made it possible to follow the effect of three different defined genetic backgrounds (first and third chromosomes) on recombination frequency in the cn-vg region of the second chromosomes isolated from four natural populations of Drosophila melanogaster. One background was composed of the chromosomes with inversions obtained from the stock (see article) and another two backgrounds were of the standard type consisting one-half of the original chromosomes from the natural population and one-half of the chromosomes of the stocks Oregon R or Samarkand. Using the analysis of variance significant differences in RF values were found between and within populations and especially between the different backgrounds. Some simple and double interactions between the above factors played a role. The highest RF values were obtained on the background [corrected] with inversions. The effect of the different genetic backgrounds [corrected] by the action of the genetic modifiers of RF. The different genetic backgrounds affected the variations in RF values in individual populations and the different populations reacted differentially to the changed genetic background. The design of the experiment permitted an estimation of the causal compoenents of variance and heritability of RF from the sib analysis. The additive component of variance was present in only two of the populations under test; the respective estimates of heritability were very low.

  19. Educating for and through Nature: A Merleau-Pontian Approach

    ERIC Educational Resources Information Center

    Hung, Ruyu

    2008-01-01

    This paper aims to explore the relationship between humans and nature and the implied intimacy, so-call "ecophilia," in light of the French philosopher Maurice Merleau-Ponty. It is revealed from the Merleau-Pontian view of body and nature that there may be a more harmonious relationship between humankind and nature than the commonly assumed, and…

  20. Oil and Gas Drilling and Operations in Cave and Karst area: Background and development of a BLM approach

    SciTech Connect

    Goodbar, J.R. )

    1994-03-01

    Karst lands pose a unique set of problems for the oil and gas industry, as well as for the cave and karst environments. Since 1987, the Bureau of Land Management (BLM) has been working with the oil and gas industry to develop acceptable practices for drilling and operation in karst lands. The mutual goals of industry and of the BLM is to minimize the potential of encountering those problems and reduce the extent of the problems, if they are encountered. BLM's approach is described in their [open quotes]Draft Guide for Oil and Gas Drilling and Operations in Cave and Karst Areas.[close quotes] This paper discusses the background and development of this guide with an emphasis on the conflict resolution approach of the BLM.

  1. Global Natural Disaster Risk Hotspots: Transition to a Regional Approach

    NASA Astrophysics Data System (ADS)

    Lerner-Lam, A.; Chen, R.; Dilley, M.

    2005-12-01

    The "Hotspots Project" is a collaborative study of the global distribution and occurrence of multiple natural hazards and the associated exposures of populations and their economic output. In this study we assess the global risks of two disaster-related outcomes: mortality and economic losses. We estimate risk levels by combining hazard exposure with historical vulnerability for two indicators of elements at risk-gridded population and Gross Domestic Product (GDP) per unit area - for six major natural hazards: earthquakes, volcanoes, landslides, floods, drought, and cyclones. By calculating relative risks for each grid cell rather than for countries as a whole, we are able to estimate risk levels at sub-national scales. These can then be used to estimate aggregate relative multiple hazard risk at regional and national scales. Mortality-related risks are assessed on a 2.5' x 2.5' latitude-longitude grid of global population (GPW Version 3). Economic risks are assessed at the same resolution for gridded GDP per unit area, using World Bank estimates of GDP based on purchasing power parity. Global hazard data were compiled from multiple sources. The project collaborated directly with UNDP and UNEP, the International Research Institute for Climate Prediction (IRI) at Columbia, and the Norwegian Geotechnical Institute (NGI) in the creation of data sets for several hazards for which global data sets did not previously exist. Drought, flood and volcano hazards are characterized in terms of event frequency, storms by frequency and severity, earthquakes by frequency and ground acceleration exceedance probability, and landslides by an index derived from probability of occurrence. The global analysis undertaken in this project is clearly limited by issues of scale as well as by the availability and quality of data. For some hazards, there exist only 15- to 25-year global records with relatively crude spatial information. Data on historical disaster losses, and particularly on

  2. A Geographic Approach to the Study of Natural Gas.

    ERIC Educational Resources Information Center

    Sheskin, Ira M.

    1980-01-01

    Provides information, tips, references, and materials to high school and college level geography teachers on developing a unit on natural gas. Data are presented in the form of tables, maps, figures, and textual analysis. (Author/DB)

  3. Exploiting new approaches for natural product drug discovery in the biotechnology industry.

    PubMed

    Gullo, Vincent P; Hughes, Dallas E

    2005-01-01

    In recent years, large pharmaceutical companies have significantly reduced or eliminated the search for new therapeutic agents from natural sources. In spite of the many successes from natural product drug discovery, these companies have chosen to focus on compound libraries as the source of new lead compounds. Smaller biotechnology companies are continuing the search for novel natural products by developing and employing new and innovative approaches. This paper will describe some of these recent approaches to natural product drug discovery.:

  4. Novel approaches for stability improvement in natural medicines

    PubMed Central

    Thakur, Lovely; Ghodasra, Umang; Patel, Nilesh; Dabhi, Mahesh

    2011-01-01

    Natural product market has seen tremendous growth in the last few years. It results in the formulation of a number of proprietary herbal products, majority of them being multi-component formulations. With the advancement of herbal drug treatments, it has now been observed that many of the constituents present in the drug may react with each other, raising the serious concern about the stability of such formulations which is an important issue in the field of phytochemistry and natural medicines. Natural products are often prone to deterioration, especially during storage, leading to loss of active component, production of metabolites with no activity and, in extreme cases, production of toxic metabolites. This area needs to be addressed in order to determine the efficacy of the formulation. Understanding the problems related to natural product stability can give the idea of dealing with the stability issues. Modifications of the conventional herbal formulations can deal with the stability problems to a large extent. This article deals with the stability problems and is aimed to provide some tools and techniques to increase stability of natural medicines and herbal formulations. PMID:22096318

  5. Novel approaches for stability improvement in natural medicines.

    PubMed

    Thakur, Lovely; Ghodasra, Umang; Patel, Nilesh; Dabhi, Mahesh

    2011-01-01

    Natural product market has seen tremendous growth in the last few years. It results in the formulation of a number of proprietary herbal products, majority of them being multi-component formulations. With the advancement of herbal drug treatments, it has now been observed that many of the constituents present in the drug may react with each other, raising the serious concern about the stability of such formulations which is an important issue in the field of phytochemistry and natural medicines. Natural products are often prone to deterioration, especially during storage, leading to loss of active component, production of metabolites with no activity and, in extreme cases, production of toxic metabolites. This area needs to be addressed in order to determine the efficacy of the formulation. Understanding the problems related to natural product stability can give the idea of dealing with the stability issues. Modifications of the conventional herbal formulations can deal with the stability problems to a large extent. This article deals with the stability problems and is aimed to provide some tools and techniques to increase stability of natural medicines and herbal formulations.

  6. Naturism and sexuality: broadening our approach to sexual wellbeing.

    PubMed

    Smith, Glenn; King, Michael

    2009-06-01

    This study aimed to investigate how people manage their sexuality when practicing naturism in the United Kingdom (UK). Thirty-nine self-identified naturists from across the UK were interviewed. Sexuality, when practicing naturism, was found often to be suppressed through the use of rules, geographical isolation and thoughts and behaviour. Some participants found ways of exploring and enjoying their sexuality by keeping feelings hidden and/or seeking out more sympathetic naturist environments. Naturist environments may offer a unique space in which to explore aspects of our sexuality that are currently pathologised, criminalised or commercialised. This has important implications for sexual health policy and promotion.

  7. Approaching Nature and Science through Outdoor Experience and Drama.

    ERIC Educational Resources Information Center

    Karvonen-Lee, Vireo

    1997-01-01

    Unit of study about rocks and the layers of the Earth focuses on building children's respect for nature by developing feelings of intimate relationship. Lesson plans include science activities (rock gathering, Earth models); "drama from the outside" (ritual to promote respect); literature readings; and "dramas from the inside"…

  8. Natural background and anthropogenic inputs of polycyclic aromatic hydrocarbons (PAH) in sediments of South-Western Barents Sea.

    PubMed

    Boitsov, Stepan; Jensen, H K B; Klungsøyr, Jarle

    2009-12-01

    Polycyclic aromatic hydrocarbons (PAH) were measured in sediment cores from 13 locations in South-Western Barents Sea as part of a detailed study of the Norwegian seabed under the MAREANO program. The generally low PAH levels found, an average around 200 ng g(-1) dry weight for sum PAH, indicate low inputs of petroleum hydrocarbons to the marine environment in the area. Differences in PAH composition and various PAH ratios indicate a natural, mostly petrogenic origin of PAH in sediments from the open sea locations, while the fjord locations show higher pyrogenic PAH contents with an increase towards upper sediment layers, indicating low inputs from human activities. Petrogenic PAH levels increase in deeper sediments at open sea locations, also when normalised to total organic carbon (TOC) contents, suggesting natural leakages of oil-related hydrocarbons in the area.

  9. The approaches for the decision support in case natural hazards

    NASA Astrophysics Data System (ADS)

    Vyazilov, Evgeny; Chunyaev, Nikita

    2013-04-01

    In spite of using highly automated systems of measurement, collecting, storing, handling, prediction and delivery of information on the marine environment, including natural hazards, the amount of damage from natural phenomena increases. Because information on the marine environment delivered to the industrial facilities not effectively used. To such information pays little attention by individual decision-makers and not always perform preventive measures necessary for reduce and prevent damage. Automation of information support will improve the efficiency management of the marine activities. In Russia develops "The Unified system of the information about World ocean" (ESIMO, http://esimo.ru/), that integrates observation, analysis, prognostic and climate data. Necessary to create tools to automatic selection natural disasters through all integrated data; notification decision-makers about arising natural hazards - software agent; provision of information in a compact form for the decision-makers; assessment of possible damage and costs to the preventive measures; providing information on the impacts of environment on economic facilities and recommendations for decision-making; the use of maps, diagrams, tables for reporting. Tools for automatic selection designed for identification of natural phenomena based on the resources ESIMO and corresponding critical values of the indicators environment. The result of this module will be constantly updated database of critical situations of environment for each object or technological process. To operational notify and provide current information about natural hazards proposes using a software agent that is installed on the computer decision-makers, which is activated in case critical situations and provides a minimum of information. In the event of natural disaster software agent should be able to inform decision-makers about this, providing information on the current situation, and the possibility for more and detailed

  10. Systems Biology Approaches to Understand Natural Products Biosynthesis.

    PubMed

    Licona-Cassani, Cuauhtemoc; Cruz-Morales, Pablo; Manteca, Angel; Barona-Gomez, Francisco; Nielsen, Lars K; Marcellin, Esteban

    2015-01-01

    Actinomycetes populate soils and aquatic sediments that impose biotic and abiotic challenges for their survival. As a result, actinomycetes metabolism and genomes have evolved to produce an overwhelming diversity of specialized molecules. Polyketides, non-ribosomal peptides, post-translationally modified peptides, lactams, and terpenes are well-known bioactive natural products with enormous industrial potential. Accessing such biological diversity has proven difficult due to the complex regulation of cellular metabolism in actinomycetes and to the sparse knowledge of their physiology. The past decade, however, has seen the development of omics technologies that have significantly contributed to our better understanding of their biology. Key observations have contributed toward a shift in the exploitation of actinomycete's biology, such as using their full genomic potential, activating entire pathways through key metabolic elicitors and pathway engineering to improve biosynthesis. Here, we review recent efforts devoted to achieving enhanced discovery, activation, and manipulation of natural product biosynthetic pathways in model actinomycetes using genome-scale biological datasets.

  11. Natural Environment Exploration Approach: The Case Study in Department of Biology, Universitas Negeri Semarang

    ERIC Educational Resources Information Center

    Alimah, Siti; Susilo, Herawati; Amin, Moh

    2016-01-01

    The study reports the evaluation and analysis of the implementation of the Nature Environment Exploration approach in the Department of Biology, Universitas Negeri Semarang State University. The method used was survey method. The results showed that the implementation of the Nature Environment Exploration approach was still far from optimal…

  12. New approach to flavor symmetry and an extended naturalness principle

    NASA Astrophysics Data System (ADS)

    Barr, S. M.

    2010-09-01

    A class of nonsupersymmetric extensions of the standard model is proposed in which there is a multiplicity of light scalar doublets in a multiplet of a nonabelian family group with the standard model Higgs doublet. Anthropic tuning makes the latter light, and consequently the other scalar doublets remain light because of the family symmetry. The family symmetry greatly constrains the pattern of flavor-changing neutral-current interactions (FCNC) and p decay operators coming from scalar-exchange. Such models show that useful constraints on model-building can come from an extended naturalness principle when the electroweak scale is anthropically tuned.

  13. Systems Biology Approaches to Understand Natural Products Biosynthesis

    PubMed Central

    Licona-Cassani, Cuauhtemoc; Cruz-Morales, Pablo; Manteca, Angel; Barona-Gomez, Francisco; Nielsen, Lars K.; Marcellin, Esteban

    2015-01-01

    Actinomycetes populate soils and aquatic sediments that impose biotic and abiotic challenges for their survival. As a result, actinomycetes metabolism and genomes have evolved to produce an overwhelming diversity of specialized molecules. Polyketides, non-ribosomal peptides, post-translationally modified peptides, lactams, and terpenes are well-known bioactive natural products with enormous industrial potential. Accessing such biological diversity has proven difficult due to the complex regulation of cellular metabolism in actinomycetes and to the sparse knowledge of their physiology. The past decade, however, has seen the development of omics technologies that have significantly contributed to our better understanding of their biology. Key observations have contributed toward a shift in the exploitation of actinomycete’s biology, such as using their full genomic potential, activating entire pathways through key metabolic elicitors and pathway engineering to improve biosynthesis. Here, we review recent efforts devoted to achieving enhanced discovery, activation, and manipulation of natural product biosynthetic pathways in model actinomycetes using genome-scale biological datasets. PMID:26697425

  14. Hepatitis C Virus and Natural Compounds: a New Antiviral Approach?

    PubMed Central

    Calland, Noémie; Dubuisson, Jean; Rouillé, Yves; Séron, Karin

    2012-01-01

    Hepatitis C is a major global health burden with an estimated 160 million infected individuals worldwide. This long-term disease evolves slowly, often leading to chronicity and potentially to liver failure. There is no anti-HCV vaccine, and, until recently, the only treatment available, based on pegylated interferon and ribavirin, was partially effective, and had considerable side effects. With recent advances in the understanding of the HCV life cycle, the development of promising direct acting antivirals (DAAs) has been achieved. Their use in combination with the current treatment has led to encouraging results for HCV genotype 1 patients. However, this therapy is quite expensive and will probably not be accessible for all patients worldwide. For this reason, constant efforts are being made to identify new antiviral molecules. Recent reports about natural compounds highlight their antiviral activity against HCV. Here, we aim to review the natural molecules that interfere with the HCV life cycle and discuss their potential use in HCV therapy. PMID:23202460

  15. Role of light and heavy minerals on natural radioactivity level of high background radiation area, Kerala, India.

    PubMed

    Ramasamy, V; Sundarrajan, M; Suresh, G; Paramasivam, K; Meenakshisundaram, V

    2014-02-01

    Natural radionuclides ((238)U, (232)Th and (40)K) concentrations and eight different radiological parameters have been analyzed for the beach sediments of Kerala with an aim of evaluating the radiation hazards. Activity concentrations ((238)U and (232)Th) and all the radiological parameters in most of the sites have higher values than recommended values. The Kerala beach sediments pose significant radiological threat to the people living in the area and tourists going to the beaches for recreation or to the sailors and fishermen involved in their activities in the study area. In order to know the light mineral characterization of the present sediments, mineralogical analysis has been carried out using Fourier transform infrared (FTIR) spectroscopic technique. The eight different minerals are identified and they are characterized. Among the various observed minerals, the minerals such as quartz, microcline feldspar, kaolinite and calcite are major minerals. The relative distribution of major minerals is determined by calculating extinction co-efficient and the values show that the amount of quartz is higher than calcite and much higher than microcline feldspar. Crystallinity index is calculated to know the crystalline nature of quartz present in the sediments. Heavy mineral separation analysis has been carried out to know the total heavy mineral (THM) percentage. This analysis revealed the presence of nine heavy minerals. The minerals such as monazite, zircon, magnetite and illmenite are predominant. Due to the rapid and extreme changes occur in highly dynamic environments of sandy beaches, quantities of major light and heavy minerals are widely varied from site to site. Granulometric analysis shows that the sand is major content. Multivariate statistical (Pearson correlation, cluster and factor) analysis has been carried out to know the effect of mineralogy on radionuclide concentrations. The present study concluded that heavy minerals induce the (238)U and (232)Th

  16. Systematic approaches to comprehensive analyses of natural organic matter

    USGS Publications Warehouse

    Leenheer, Jerry A.

    2009-01-01

    The more that is learned of the chemistry of aquatic natural organic matter (NOM) the greater is the scientific appreciation of the vast complexity of this subject. This complexity is due not only to a multiplicity of precursor molecules in any environment but to their associations with each other and with other components of local environments such as clays, mineral acids and dissolved metals. In addition, this complex system is subject to constant change owing to environmental variables and microbial action. Thus, there is a good argument that no two NOM samples are exactly the same even from the same source at nearly the same time. When ubiquity of occurrence, reaction with water treatment chemicals, and subsequent human exposure are added to the list of NOM issues, one can understand the appeal that this subject holds for a wide variety of environmental scientists.

  17. A conformal variational approach for helices in nature

    NASA Astrophysics Data System (ADS)

    Barros, Manuel; Ferrández, Angel

    2009-10-01

    We propose a two step variational principle to describe helical structures in nature. The first one is governed by an energy action which is a linear function in both curvature and torsion allowing to describe nonclosed structures including elliptical, spherical, and conical helices. These appear as rhumb lines in right cylinders constructed over plane curves. The model is completed with a conformal alternative which, in particular, gives a description of closed structures. The energy action is linear in the curvatures when computed in a conformal spherical metric. Now, helices appear as making a constant angle with a Villarceau flow and so they are loxodromes in surfaces which are stereographic projections of Hopf tubes, in particular, anchor rings, revolution tori, and Dupin cyclides. The model satisfies the requirements of simplicity and beauty as reflected in the three main principles that head its construction: least action, topological, and quantization. According to the latter, the main entities and quantities associated with the model should not be multiplied unnecessarily but they are quantized. In this sense, a quantization principle, a la Dirac, is obtained for closed structures and also for the critical levels of energy.

  18. Parents' Experiences of the Provision of Community-Based Family Support and Therapy Services Utilizing the Strengths Approach and Natural Learning Environments

    ERIC Educational Resources Information Center

    Carlson, Glenys; Armitstead, Clare; Rodger, Sylvia; Liddle, Gwen

    2010-01-01

    Background: In recent years, community based therapy service providers have explored different service delivery models to optimize child and family outcomes. This qualitative study aimed to explore parents' experiences of one particular service team that adopted a strengths approach, utilizing natural learning environments. Materials and methods:…

  19. The Notional-Functional Approach: Teaching the Real Language in Its Natural Context.

    ERIC Educational Resources Information Center

    Laine, Elaine

    This study of the notional-functional approach to second language teaching reviews the history and theoretical background of the method, current issues, and implementation of a notional-functional syllabus. Chapter 1 discusses the history and theory of the approach and the organization and advantages of the notional-functional syllabus. Chapter 2…

  20. COMPARISON OF NATURAL BACKGROUND DOSE RATES FOR RESIDENTS OF THE AMARGOSA VALLEY, NV, TO THOSE IN LEADVILLE, CO, AND THE STATES OF COLORADO AND NEVADA

    SciTech Connect

    D. Moeller and L. C. Sun

    2006-02-24

    In the latter half of 2005, the U.S. Environmental Protection Agency (USEPA) published a Proposed Rule (40 CFR Part 197) for establishing a dose rate standard for limiting radionuclide releases from the proposed Yucca Mountain high-level radioactive waste repository during the time period from 10{sup 4} to 10{sup 6} years after closure. The proposed standard was based on the difference in the estimated total dose rate from natural background in the Amargosa Valley and the ''average annual background radiation'' for the State of Colorado. As defined by the USEPA, ''natural background radiation consists of external exposures from cosmic and terrestrial sources, and internal exposures from indoor exposures to naturally-occurring radon''. On the basis of its assessments, the USEPA estimated that the difference in the dose rate in the two identified areas was 3.5 mSv y{sup -1}. The purpose of this review was to provide an independent evaluation and review of this estimate. One of the first observations was that, because site-specific dose rate measurements for the Amargosa Valley ''were not available'', the dose rates for various sources of natural background in that area, used by the USEPA in its assessment, were based on modifications of the average values for the State of Nevada. A second observation was that the conversion factor applied in estimating the dose rates due to exposures to indoor radon and its decay products was a factor of 2 higher than the currently accepted value. Further review revealed that site-specific data for many natural background sources in the Amargosa Valley were available. One particularly important observation was that about 91% of the residents of that area live in mobile homes which, due to their construction and design, have indoor radon concentrations comparable to, or less than, those outdoors. For that reason, alone, the USEPA estimate of the average dose rate for residents of the Amargosa Valley, due to indoor radon, was not valid

  1. Monitoring Perinatal Gut Microbiota in Mouse Models by Mass Spectrometry Approaches: Parental Genetic Background and Breastfeeding Effects

    PubMed Central

    Levi Mortera, Stefano; Del Chierico, Federica; Vernocchi, Pamela; Rosado, Maria M.; Cavola, Agnese; Chierici, Marco; Pieroni, Luisa; Urbani, Andrea; Carsetti, Rita; Lante, Isabella; Dallapiccola, Bruno; Putignani, Lorenza

    2016-01-01

    At birth, contact with external stimuli, such as nutrients derived from food, is necessary to modulate the symbiotic balance between commensal and pathogenic bacteria, protect against bacterial dysbiosis, and initiate the development of the mucosal immune response. Among a variety of different feeding patterns, breastfeeding represents the best modality. In fact, the capacity of breast milk to modulate the composition of infants’ gut microbiota leads to beneficial effects on their health. In this study, we used newborn mice as a model to evaluate the effect of parental genetic background (i.e., IgA-producing mice and IgA-deficient mice) and feeding modulation (i.e., maternal feeding and cross-feeding) on the onset and shaping of gut microbiota after birth. To investigate these topics, we used either a culturomic approach that employed Matrix Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry (MS), or bottom–up Liquid Chromatography, with subsequent MSMS shotgun metaproteomic analysis that compared and assembled results of the two techniques. We found that the microbial community was enriched by lactic acid bacteria when pups were breastfed by wild-type (WT) mothers, while IgA-deficient milk led to an increase in the opportunistic bacterial pathogen (OBP) population. Cross-feeding results suggested that IgA supplementation promoted the exclusion of some OBPs and the temporary appearance of beneficial species in pups fed by WT foster mothers. Our results show that both techniques yield a picture of microbiota from different angles and with varying depths. In particular, our metaproteomic pipeline was found to be a reliable tool in the description of microbiota. Data from these studies are available via ProteomeXchange, with identifier PXD004033. PMID:27725814

  2. Assessment of indoor radiation dose received by the residents of natural high background radiation areas of coastal villages of Kanyakumari district, Tamil Nadu, India

    NASA Astrophysics Data System (ADS)

    Deva Jayanthi, D.; Maniyan, C. G.; Perumal, S.

    2011-07-01

    Radiation exposure and effective dose received through two routes of exposure, viz. external and internal, via inhalation, by residents of 10 villages belonging to Natural High Background Radiation Areas (NHBRA) of coastal regions of Kanyakumari District and Tamil Nadu in India were studied. While the indoor gamma radiation levels were monitored using Thermo Luminescent Dosimeters (TLDs), the indoor radon and thoron gas concentrations were measured using twin chamber dosimeters employing Solid State Nuclear Track Detectors (SSNTDs, LR-115-II). The average total annual effective dose was estimated and found to be varying from 2.59 to 8.76 mSv.

  3. The inextricable axis of targeted diagnostic imaging and therapy: An immunological natural history approach.

    PubMed

    Cope, Frederick O; Abbruzzese, Bonnie; Sanders, James; Metz, Wendy; Sturms, Kristyn; Ralph, David; Blue, Michael; Zhang, Jane; Bracci, Paige; Bshara, Wiam; Behr, Spencer; Maurer, Toby; Williams, Kenneth; Walker, Joshua; Beverly, Allison; Blay, Brooke; Damughatla, Anirudh; Larsen, Mark; Mountain, Courtney; Neylon, Erin; Parcel, Kaeli; Raghuraman, Kapil; Ricks, Kevin; Rose, Lucas; Sivakumar, Akhilesh; Streck, Nicholas; Wang, Bryan; Wasco, Christopher; Williams, Amifred; McGrath, Michael

    2016-03-01

    In considering the challenges of approaches to clinical imaging, we are faced with choices that sometimes are impacted by rather dogmatic notions about what is a better or worse technology to achieve the most useful diagnostic image for the patient. For example, is PET or SPECT most useful in imaging any particular disease dissemination? The dictatorial approach would be to choose PET, all other matters being equal. But is such a totalitarian attitude toward imaging selection still valid? In the face of new receptor targeted SPECT agents one must consider the remarkable specificity and sensitivity of these agents. (99m)Tc-Tilmanocept is one of the newest of these agents, now approved for guiding sentinel node biopsy (SLNB) in several solid tumors. Tilmanocept has a Kd of 3×10(-11)M, and it specificity for the CD206 receptor is unlike any other agent to date. This coupled with a number of facts, that specific disease-associated macrophages express this receptor (100 to 150 thousand receptors), that the receptor has multiple binding sites for tilmanocept (>2 sites per receptor) and that these receptors are recycled every 15 min to bind more tilmanocept (acting as intracellular "drug compilers" of tilmanocept into non-degraded vesicles), gives serious pause as to how we select our approaches to diagnostic imaging. Clinically, the size of SLNs varies greatly, some, anatomically, below the machine resolution of SPECT. Yet, with tilmanocept targeting, the SLNs are highly visible with macrophages stably accruing adequate (99m)Tc-tilmanocept counting statistics, as high target-to-background ratios can compensate for spatial resolution blurring. Importantly, it may be targeted imaging agents per se, again such as tilmanocept, which may significantly shrink any perceived chasm between the imaging technologies and anchor the diagnostic considerations in the targeting and specificity of the agent rather than any lingering dogma about the hardware as the basis for imaging

  4. The Inextricable Axis Of Targeted Diagnostic Imaging And Therapy: An Immunological Natural History Approach

    PubMed Central

    Cope, FO; Abbruzzese, B; Sanders, J; Metz, W; Sturms, K; Ralph, D; Blue, M; Zhang, J; Bracci, P; Bshara, W; Behr, S; Maurer, T; Beverly, A; Blay, B; Damughatla, A; Larsen, M; Mountain, C; Neylon, E; Parcel, K; Raghuraman, K; Ricks, K; Rose, L; Sivakumar, A; Streck, N; Wang, B; Wasco, C; Williams, A; McGrath, M

    2016-01-01

    Summary In considering the challenges of approaches to clinical imaging, we are faced with choices that sometimes are impacted by rather dogmatic notions about what is a better or worse technology to achieve the most useful diagnostic image for the patient. For example, is PET or SPECT most useful in imaging any particular disease dissemination? The dictatorial approach would be to choose PET, all other matters being equal. But is such a totalitarian attitude toward imaging selection still valid? In the face of new receptor targeted SPECT agents one must consider the remarkable specificity and sensitivity of these agents. 99mTc-Tilmanocept is one of the newest of these agents, now approved for guiding sentinel node biopsy (SLNB) in several solid tumors. Tilmanocept has a Kd of 3×10−11 M, and it specificity for the CD206 receptor is unlike any other agent to date. This coupled with a number of facts, that specific disease-associated macrophages express this receptor (100 to 150 thousand receptors), the receptor has multiple binding sites for tilmanocept (>2 sites per receptor) and that these receptors are recycled every 15 minutes to bind more tilmanocept (acting as intracellular “drug compilers” of tilmanocept into non-degraded vesicles), give serious pause as to how we select our approaches to diagnostic imaging. Clinically, the size of SLNs varies greatly, some, anatomically, below the machine resolution of SPECT. Yet, with tilmanocept targeting, the SLNs are highly visible with macrophages stably accruing adequate 99mTc-tilmanocept counting statistics, as high target-to-background ratios can compensate for spatial resolution blurring. Importantly, it may be targeted imaging agents per se, again such as tilmanocept, which may significantly shrink any perceived chasm between the imaging technologies and anchor the diagnostic considerations in the targeting and specificity of the agent rather than any lingering dogma about the hardware as the basis for

  5. Learning Nature of Science Concepts through a Research Apprenticeship Program: A Comparative Study of Three Approaches

    ERIC Educational Resources Information Center

    Burgin, Stephen R.; Sadler, Troy D.

    2016-01-01

    The merits of three approaches (explicit, reflective and implicit) to Nature of Science (NOS) teaching and learning in the context of a summer research experience on high school student participants' NOS ideas were explored in this study. The effectiveness of explicit over implicit approaches has been demonstrated in school contexts, but less…

  6. Teaching Nature of Science to Pre-Service Early Childhood Teachers through an Explicit Reflective Approach

    ERIC Educational Resources Information Center

    Cil, Emine

    2014-01-01

    In this study, fifteen pre-service early childhood teachers' views of nature of science (NOS) were analysed. The student teachers took a course where NOS was taught via explicit reflective approach. The explicit reflective approach advocates that goal of improving students' NOS views should be planned for instead of being anticipated as…

  7. Psychological linguistics: A natural science approach to the study of language interactions

    PubMed Central

    Bijou, Sidney W.; Umbreit, John; Ghezzi, Patrick M.; Chao, Chia-Chen

    1986-01-01

    Kantor's theoretical analysis of “psychological linguistics” offers a natural science approach to the study of linguistic behavior and interactions. This paper includes brief descriptions of (a) some of the basic assumptions of the approach, (b) Kantor's conception of linguistic behavior and interactions, (c) a compatible research method and sample research data, and (d) some areas of research and application. PMID:22477507

  8. How to Use Historical Approach to Teach Nature of Science in Chemistry Education?

    ERIC Educational Resources Information Center

    Tolvanen, Simo; Jansson, Jan; Vesterinen, Veli-Matti; Aksela, Maija

    2014-01-01

    Successful implementation of historical approach to teach nature of science (NOS) requires suitable curriculum material. Several research and development projects have produced lesson plans for science teachers. 25 lesson plans from four different projects involved in creating curriculum material utilizing historical approach in chemistry…

  9. Of the necessity of knowledge of the natural pedo-geochemical background content in the evaluation of the contamination of soils by trace elements.

    PubMed

    Baize, D; Sterckeman, T

    2001-01-08

    In order to evaluate the contamination of the Dornach (Switzerland) site within the framework of the CEEM-Soil project, each participating team was allowed to take a maximum of 15 samples. The French team's sampling was organized in such a way as to answer the following questions: (i) what is the natural concentration of the soils at this site (local pedo-geochemical background content)?; (ii) what are the levels of Cd, Cu, Pb and Zn contamination of the soil?; (iii) what is the depth reached by the surface contamination that is derived from atmospheric fallout?; (iv) how is the contamination spread along the longest axis of the area under study? The relationships between total Fe and the trace metals have allowed local variations in the natural pedo-geochemical background content to be detected and thus permitted the anthropogenic contamination to be estimated. There would appear to be a low level of Pb contamination over all the site investigated (an increase of the order of 5-10 mg kg(-1) on the background level), limited to the surface humus-bearing layers. There is also a significant contamination by Cu over all of the site (an increase of the order of 30-40 mg kg(-1)). This contamination has remained in the surface horizons (0-20 cm). Very high Zn and Cd concentrations have been found in the four surface (0-4 cm) and deep horizons (15-70 cm) taken under the forest and very much lower values in the samples taken from cultivated soils. The most likely explanation is an unequal inheritance between the upper part of the site (wooded with thinner very clayey soils) and the lower cultivated part of the site (with thicker less clayey soils developed in a loamy material). For various reasons, it seems unlikely that a contamination of the wooded part should be so much higher than the cultivated part due to the interception of atmospheric dust by the trees. The local pedo-geochemical background Cd and Zn content of the upper wooded part proved to be clearly higher than

  10. 'Natural background' soil water repellency in conifer forests of the north-western USA: Its prediction and relationship to wildfire occurrence

    USGS Publications Warehouse

    Doerr, S.H.; Woods, S.W.; Martin, D.A.; Casimiro, M.

    2009-01-01

    Soils under a wide range of vegetation types exhibit water repellency following the passage of a fire. This is viewed by many as one of the main causes for accelerated post-fire runoff and soil erosion and it has often been assumed that strong soil water repellency present after wildfire is fire-induced. However, high levels of repellency have also been reported under vegetation types not affected by fire, and the question arises to what degree the water repellency observed at burnt sites actually results from fire. This study aimed at determining 'natural background' water repellency in common coniferous forest types in the north-western USA. Mature or semi-mature coniferous forest sites (n = 81), which showed no evidence of recent fires and had at least some needle cast cover, were sampled across six states. After careful removal of litter and duff at each site, soil water repellency was examined in situ at the mineral soil surface using the Water Drop Penetration Time (WDPT) method for three sub-sites, followed by collecting near-surface mineral soil layer samples (0-3 cm depth). Following air-drying, samples were further analyzed for repellency using WDPT and contact angle (??sl) measurements. Amongst other variables examined were dominant tree type, ground vegetation, litter and duff layer depth, slope angle and aspect, elevation, geology, and soil texture, organic carbon content and pH. 'Natural background' water repellency (WDPT > 5 s) was detected in situ and on air-dry samples at 75% of all sites examined irrespective of dominant tree species (Pinus ponderosa, Pinus contorta, Picea engelmanii and Pseudotsuga menziesii). These findings demonstrate that the soil water repellency commonly observed in these forest types following burning is not necessarily the result of recent fire but can instead be a natural characteristic. The notion of a low background water repellency being typical for long-unburnt conifer forest soils of the north-western USA is

  11. Copy, edit, and paste: natural product approaches to biomaterials and neuroengineering.

    PubMed

    Gademann, Karl

    2015-03-17

    Progress in the chemical sciences has formed the world we live in, both on a macroscopic and on a nanoscopic scale. The last century witnessed the development of high performance materials that interact with humans on many layers, from clothing to construction, from media to medical devices. On a molecular level, natural products and their derivatives influence many biological processes, and these compounds have enormously contributed to the health and quality of living of humans. Although coatings of stone materials with oils or resins (containing natural products) have led to improved tools already millennia ago, in contrast today, natural product approaches to designer materials, that is, combining the best of both worlds, remain scarce. In this Account, we will summarize our recent research efforts directed to the generation of natural product functionalized materials, exploiting the strategy of "copy, edit, and paste with natural products". Natural products embody the wisdom of evolution, and only total synthesis is able to unlock the secrets enshrined in their molecular structure. We employ total synthesis ("copy") as a scientific approach to address problems related to molecular structure, the biosynthesis of natural products, and their bioactivity. Additionally, the fundamental desire to investigate the mechanism of action of natural products constitutes a key driver for scientific inquiry. In an emerging area of relevance to society, we have prepared natural products such as militarinone D that can stimulate neurite outgrowth and facilitate nerve regeneration. This knowledge obtained by synthetic organic chemistry on complex natural products can then be used to design structurally simplified compounds that retain the biological power of the parent natural product ("edit"). This process, sometimes referred to as function-oriented synthesis, allows obtaining derivatives with better properties, improving their chemical tractability and reducing the step count

  12. Multi-Site Application of the Geomechanical Approach for Natural Fracture Exploration

    SciTech Connect

    R. L. Billingsley; V. Kuuskraa

    2006-03-31

    In order to predict the nature and distribution of natural fracturing, Advanced Resources Inc. (ARI) incorporated concepts of rock mechanics, geologic history, and local geology into a geomechanical approach for natural fracture prediction within mildly deformed, tight (low-permeability) gas reservoirs. Under the auspices of this project, ARI utilized and refined this approach in tight gas reservoir characterization and exploratory activities in three basins: the Piceance, Wind River and the Anadarko. The primary focus of this report is the knowledge gained on natural fractural prediction along with practical applications for enhancing gas recovery and commerciality. Of importance to tight formation gas production are two broad categories of natural fractures: (1) shear related natural fractures and (2) extensional (opening mode) natural fractures. While arising from different origins this natural fracture type differentiation based on morphology is sometimes inter related. Predicting fracture distribution successfully is largely a function of collecting and understanding the available relevant data in conjunction with a methodology appropriate to the fracture origin. Initially ARI envisioned the geomechanical approach to natural fracture prediction as the use of elastic rock mechanics methods to project the nature and distribution of natural fracturing within mildly deformed, tight (low permeability) gas reservoirs. Technical issues and inconsistencies during the project prompted re-evaluation of these initial assumptions. ARI's philosophy for the geomechanical tools was one of heuristic development through field site testing and iterative enhancements to make it a better tool. The technology and underlying concepts were refined considerably during the course of the project. As with any new tool, there was a substantial learning curve. Through a heuristic approach, addressing these discoveries with additional software and concepts resulted in a stronger set of

  13. Predominant anthropogenic sources and rates of atmospheric mercury accumulation in southern Ontario recorded by peat cores from three bogs: comparison with natural "background" values (past 8000 years).

    PubMed

    Givelet, Nicolas; Roos-Barraclough, Fiona; Shotyk, William

    2003-12-01

    Peat cores from three bogs in southern Ontario provide a complete, quantitative record of net rates of atmospheric Hg accumulation since pre-industrial times. For comparison with modern values, a peat core extending back 8000 years was used to quantify the natural variations in Hg fluxes for this region, and their dependence on climatic change and land use history. The net mercury accumulation rates were separated into "natural" and "excess" components by comparing the Hg/Br ratios of modern samples with the long-term, pre-anthropogenic average Hg/Br. The average background mercury accumulation rate during the pre-anthropogenic period (from 5700 years BC to 1470 AD) was 1.4 +/- 1.0 microg m(-2) per year (n = 197). The beginning of Hg contamination from anthropogenic sources dates from AD 1475 at the Luther Bog, corresponding to biomass burning for agricultural activities by Native North Americans. During the late 17th and 18th centuries, deposition of anthropogenic Hg was at least equal to that of Hg from natural sources. Anthropogenic inputs of Hg to the bogs have dominated continuously since the beginning of the 19th century. The maximum Hg accumulation rates decrease in the order Sifton Bog, in the City of London, Ontario (141 microg Hg m(-2) per year), Luther Bog in an agricultural region (89 microg Hg m(-2) per year), and Spruce Bog which is in a comparatively remote, forested region (54 microg Hg m(-2) per year). Accurate age dating of recent peat samples using the bomb pulse curve of 14C shows that the maximum rate of atmospheric Hg accumulation occurred during AD 1956 and 1959 at all sites. In these (modern) samples, the Hg concentration profiles resemble those of Pb, an element which is known to be immobile in peat bogs. The correlation between these two metals, together with sulfur, suggests that the predominant anthropogenic source of Hg (and Pb) was coal burning. While Hg accumulation rates have gone into strong decline since the late 1950's, Hg

  14. Examination of the Cross-Battery Approach for the Cognitive Assessment of Children and Youth from Diverse Linguistic and Cultural Backgrounds

    ERIC Educational Resources Information Center

    Kranzler, John H.; Flores, Cindi G.; Coady, Maria

    2010-01-01

    Flanagan, Ortiz, and Alfonso (2007) recently developed the Culture-Language Interpretive Matrices (C-LIMs) for the cognitive assessment of children and youth from culturally and linguistically diverse backgrounds. To examine the utility of this new approach, we administered the Woodcock-Johnson Tests of Cognitive Abilities to a sample of students…

  15. Diversity in Intensive English Language Centres in South Australia: Sociocultural Approaches to Education for Students with Migrant or Refugee Backgrounds

    ERIC Educational Resources Information Center

    Due, Clemence; Riggs, Damien W.; Augoustinos, Martha

    2016-01-01

    While there is a body of research concerning the education of students with migrant or refugee backgrounds, little of this research focuses on primary school-aged children. In order to address this gap, the current paper utilises data gained from an ethnographic study to consider the challenges and opportunities associated with diverse classrooms…

  16. Five C Framework: A Student-Centered Approach for Teaching Programming Courses to Students with Diverse Disciplinary Background

    ERIC Educational Resources Information Center

    Tom, Mary

    2015-01-01

    The already existing complexities of teaching and learning computer programming are increased where students are diverse in their disciplinary backgrounds, language skills, and culture. Learners experience emotional issues of anxiety, fear or boredom. Identifying opportunities for improvement and applying theoretical and empirical evidence found…

  17. A combined approach of Kullback-Leibler divergence and background subtraction for moving object detection in thermal video

    NASA Astrophysics Data System (ADS)

    Yadav, Dileep Kumar; Singh, Karan

    2016-05-01

    In this work, a robust method for moving object detection in thermal video frames has been proposed by including Kullback-Leibler divergence (KLD) based threshold and background subtraction (BGS) technique. A trimmed-mean based background model has been developed that is capable enough to reduce noise or dynamic component of the background. This work assumed that each pixel has normally distributed. The KLD has computed between background pixel and a current pixel with the help of Gaussian mixture model. The proposed threshold is useful enough to classify the state of each pixel. The post-processing step uses morphological tool for edge linking, and then the flood-fill algorithm has applied for hole-filling, and finally the silhouette of targeted object has generated. The proposed methods run faster and have validated over various real-time based problematic thermal video sequences. In the experimental results, the average value of F1-score, area under the curve, the percentage of correct classification, Matthew's correlation coefficient show higher values whereas total error and percentage of the wrong classification show minimum values. Moreover, the proposed-1 method achieved higher accuracy and execution speed with minimum false alarm rate that has been compared with proposed-2 as well as considered peer methods in the real-time thermal video.

  18. A New Approach for Estimating Background Rates of Erosion Using Concentration of Meteoric 10-Be Adhered to River Sediment: Application to the Rapidly Eroding Waipaoa Basin, New Zealand

    NASA Astrophysics Data System (ADS)

    Reusser, L. J.; Bierman, P. R.; Pavich, M.; Finkel, R.

    2007-12-01

    -day sediment yields are at least seven times higher than natural rates of sediment generation. This finding is in tight agreement with other estimates of pre-settlement sediment discharge from the Waipaoa Basin derived from middle shelf and nearby lake cores (Kettner et al., 2007; Page and Trustrum, 1997). Tributary basins (n=4) draining portions of the Waipaoa Basin dominated by landsliding in shallow soils yield an average background sediment generation rate of 106 ± 105 kg/(km2 * yr), assuming a deposition rate of 1.3 million atoms 10-Be/(cm2 * yr). Conversely, sediment shed from a basin dominated by severe gullying contains ~four times less 10-Be due to the contribution of deeply sourced material containing little or no meteoric 10-Be. Large basins to the north and south of the Waipaoa (n=3) yield similar background rates of sediment generation ranging from 0.25 to 1.6 million kg/(km2 * yr). Meteoric analysis of an additional 40 samples, as well as cross-calibration between in situ produced and meteoric 10-Be in 19 quartz-bearing samples will further test the robustness of this new approach for estimating natural rates of sediment generation and erosion.

  19. Affinity Crystallography: A New Approach to Extracting High-Affinity Enzyme Inhibitors from Natural Extracts.

    PubMed

    Aguda, Adeleke H; Lavallee, Vincent; Cheng, Ping; Bott, Tina M; Meimetis, Labros G; Law, Simon; Nguyen, Nham T; Williams, David E; Kaleta, Jadwiga; Villanueva, Ivan; Davies, Julian; Andersen, Raymond J; Brayer, Gary D; Brömme, Dieter

    2016-08-26

    Natural products are an important source of novel drug scaffolds. The highly variable and unpredictable timelines associated with isolating novel compounds and elucidating their structures have led to the demise of exploring natural product extract libraries in drug discovery programs. Here we introduce affinity crystallography as a new methodology that significantly shortens the time of the hit to active structure cycle in bioactive natural product discovery research. This affinity crystallography approach is illustrated by using semipure fractions of an actinomycetes culture extract to isolate and identify a cathepsin K inhibitor and to compare the outcome with the traditional assay-guided purification/structural analysis approach. The traditional approach resulted in the identification of the known inhibitor antipain (1) and its new but lower potency dehydration product 2, while the affinity crystallography approach led to the identification of a new high-affinity inhibitor named lichostatinal (3). The structure and potency of lichostatinal (3) was verified by total synthesis and kinetic characterization. To the best of our knowledge, this is the first example of isolating and characterizing a potent enzyme inhibitor from a partially purified crude natural product extract using a protein crystallographic approach.

  20. Peripheral blood lymphocyte micronucleus frequencies in men from areas of Kerala, India, with high vs normal levels of natural background ionizing radiation.

    PubMed

    Karuppasamy, C V; Ramachandran, E N; Kumar, V Anil; Kumar, P R Vivek; Koya, P K M; Jaikrishan, G; Das, Birajalaxmi

    2016-04-01

    We have measured the frequencies of micronuclei (MN) in adult male individuals living in areas of the Kerala coast, southwest India, with either high (HLNRA, >1.5mGy/year) or normal levels of natural ionizing radiation (NLNRA, ≤1.5mGy/year). Blood samples were obtained from 141 individuals, 94 from HLNRA and 47 from NLNRA, aged 18-72, and were subjected to the cytokinesis-block micronucleus (CBMN) assay. An average of 1835 binucleated (BN) cells per individual were scored. The overall frequency of MN (mean±SD) was 11.7±6.7 per 1000 BN cells. The frequencies of MN in the HLNRA (11.7±6.6) and NLNRA (11.6±6.7) were not statistically significantly different (P=0.59). However, a statistically significant (P<0.001) age-dependent increase in MN frequency was observed among individuals from both HLNRA and NLNRA. No natural background radiation dose-dependent increase in MN frequency was seen. MN frequency was not influenced by tobacco smoking or chewing but it was increased among individuals consuming alcohol. Chronic low-dose radiation in the Kerala coast did not have a significant effect on MN frequency among adult men.

  1. Natural approaches to prevention and treatment of infections of the lower urinary tract.

    PubMed

    Head, Kathleen A

    2008-09-01

    Infections of the lower urinary tract are common occurrences in young women, during pregnancy, and in peri- and postmenopausal women. Because of the chronic nature of urinary tract infections (UTIs) and the potential for antibiotic resistance, a natural approach to prevention and treatment is desirable. Clinical research suggests the best natural options for long-term prevention include cranberry, mannose, and probiotics. Botanicals that can be effective at the first sign of an infection and for short-term prophylaxis include berberine and uva ursi. Estriol cream and vitamins A and C have also been shown to prevent UTIs, while potassium salts can alkalinize the urine and reduce dysuria.

  2. Natural resource assessment: an approach to science based planning in national parks

    USGS Publications Warehouse

    Mahan, C.G.; Vanderhorst, J.P.; Young, J.A.

    2009-01-01

    We conducted a natural resource assessment at two national parks, New River Gorge National River and Shenandoah National Park, to help meet the goals of the Natural Resource Challenge-a program to help strengthen natural resource management at national parks. We met this challenge by synthesizing and interpreting natural resource information for planning purposes and we identified information gaps and natural significance of resources. We identified a variety of natural resources at both parks as being globally and/or nationally significant, including large expanses of unfragmented, mixed-mesophytic forests that qualify for wilderness protection, rare plant communities, diverse assemblages of neotropical migratory birds and salamanders, and outstanding aquatic recreational resources. In addition, these parks function, in part, as ecological reserves for plants in and wildlife. With these significant natural resources in mind, we also developed a suite of natural resource management recommendations in light of increasing threats from within and outside park boundaries. We hope that our approach can provide a blueprint for natural resource conservation at publically owned lands.

  3. Natural resource assessment: an approach to science based planning in national parks.

    PubMed

    Mahan, Carolyn G; Vanderhorst, James P; Young, John A

    2009-06-01

    We conducted a natural resource assessment at two national parks, New River Gorge National River and Shenandoah National Park, to help meet the goals of the Natural Resource Challenge--a program to help strengthen natural resource management at national parks. We met this challenge by synthesizing and interpreting natural resource information for planning purposes and we identified information gaps and natural significance of resources. We identified a variety of natural resources at both parks as being globally and/or nationally significant, including large expanses of unfragmented, mixed-mesophytic forests that qualify for wilderness protection, rare plant communities, diverse assemblages of neotropical migratory birds and salamanders, and outstanding aquatic recreational resources. In addition, these parks function, in part, as ecological reserves for plants in and wildlife. With these significant natural resources in mind, we also developed a suite of natural resource management recommendations in light of increasing threats from within and outside park boundaries. We hope that our approach can provide a blueprint for natural resource conservation at publically owned lands.

  4. Natural Resource Assessment: An Approach to Science Based Planning in National Parks

    NASA Astrophysics Data System (ADS)

    Mahan, Carolyn G.; Vanderhorst, James P.; Young, John A.

    2009-06-01

    We conducted a natural resource assessment at two national parks, New River Gorge National River and Shenandoah National Park, to help meet the goals of the Natural Resource Challenge—a program to help strengthen natural resource management at national parks. We met this challenge by synthesizing and interpreting natural resource information for planning purposes and we identified information gaps and natural significance of resources. We identified a variety of natural resources at both parks as being globally and/or nationally significant, including large expanses of unfragmented, mixed-mesophytic forests that qualify for wilderness protection, rare plant communities, diverse assemblages of neotropical migratory birds and salamanders, and outstanding aquatic recreational resources. In addition, these parks function, in part, as ecological reserves for plants in and wildlife. With these significant natural resources in mind, we also developed a suite of natural resource management recommendations in light of increasing threats from within and outside park boundaries. We hope that our approach can provide a blueprint for natural resource conservation at publically owned lands.

  5. S-matrix decomposition, natural reaction channels, and the quantum transition state approach to reactive scattering

    NASA Astrophysics Data System (ADS)

    Manthe, Uwe; Ellerbrock, Roman

    2016-05-01

    A new approach for the quantum-state resolved analysis of polyatomic reactions is introduced. Based on the singular value decomposition of the S-matrix, energy-dependent natural reaction channels and natural reaction probabilities are defined. It is shown that the natural reaction probabilities are equal to the eigenvalues of the reaction probability operator [U. Manthe and W. H. Miller, J. Chem. Phys. 99, 3411 (1993)]. Consequently, the natural reaction channels can be interpreted as uniquely defined pathways through the transition state of the reaction. The analysis can efficiently be combined with reactive scattering calculations based on the propagation of thermal flux eigenstates. In contrast to a decomposition based straightforwardly on thermal flux eigenstates, it does not depend on the choice of the dividing surface separating reactants from products. The new approach is illustrated studying a prototypical example, the H + CH4 → H2 + CH3 reaction. The natural reaction probabilities and the contributions of the different vibrational states of the methyl product to the natural reaction channels are calculated and discussed. The relation between the thermal flux eigenstates and the natural reaction channels is studied in detail.

  6. S-matrix decomposition, natural reaction channels, and the quantum transition state approach to reactive scattering.

    PubMed

    Manthe, Uwe; Ellerbrock, Roman

    2016-05-28

    A new approach for the quantum-state resolved analysis of polyatomic reactions is introduced. Based on the singular value decomposition of the S-matrix, energy-dependent natural reaction channels and natural reaction probabilities are defined. It is shown that the natural reaction probabilities are equal to the eigenvalues of the reaction probability operator [U. Manthe and W. H. Miller, J. Chem. Phys. 99, 3411 (1993)]. Consequently, the natural reaction channels can be interpreted as uniquely defined pathways through the transition state of the reaction. The analysis can efficiently be combined with reactive scattering calculations based on the propagation of thermal flux eigenstates. In contrast to a decomposition based straightforwardly on thermal flux eigenstates, it does not depend on the choice of the dividing surface separating reactants from products. The new approach is illustrated studying a prototypical example, the H + CH4 → H2 + CH3 reaction. The natural reaction probabilities and the contributions of the different vibrational states of the methyl product to the natural reaction channels are calculated and discussed. The relation between the thermal flux eigenstates and the natural reaction channels is studied in detail.

  7. Understanding Nature-Related Behaviors among Children through a Theory of Reasoned Action Approach

    ERIC Educational Resources Information Center

    Gotch, Chad; Hall, Troy

    2004-01-01

    The Theory of Reasoned Action has proven to be a valuable tool for predicting and understanding behavior and, as such, provides a potentially important basis for environmental education program design. This study used a Theory of Reasoned Action approach to examine a unique type of behavior (nature-related activities) and a unique population…

  8. Understanding the Nature of Science and Scientific Progress: A Theory-Building Approach

    ERIC Educational Resources Information Center

    Chuy, Maria; Scardamalia, Marlene; Bereiter, Carl; Prinsen, Fleur; Resendes, Monica; Messina, Richard; Hunsburger, Winifred; Teplovs, Chris; Chow, Angela

    2010-01-01

    In 1993 Carey and Smith conjectured that the most promising way to boost students' understanding of the nature of science is a "theory-building approach to teaching about inquiry." The research reported here tested this conjecture by comparing results from two Grade 4 classrooms that differed in their emphasis on and technological…

  9. A New Computerized Approach for Teaching the Nature of Membrane Potentials.

    ERIC Educational Resources Information Center

    Vazquez, Jesus

    1991-01-01

    Presents a BASIC program that can be useful in explaining physicochemical phenomena underlying the generation of membrane potential in excitable cells. Its simplicity allows students to understand the nature of these processes through a direct, hands-on approach. Also, the simulated voltage and concentration kinetics agree well with those…

  10. Traditional, Natural, and TPR Approaches to ESL: A Study of Japanese Students.

    ERIC Educational Resources Information Center

    Furuhata, Hamako

    1999-01-01

    Reports a study of Japanese students' perception of traditional methods versus the natural approach and total physical response (TPR) methods for learning English, and their preferred styles of learning. Subjects were Japanese students attending intensive language schools in the U.S. Students generally preferred innovative methods, such as…

  11. Models in physics teaching: an approach to highlight the nature of knowledge

    NASA Astrophysics Data System (ADS)

    Botelho Kneubil, Fabiana

    2016-11-01

    In this work we show an approach based on models, for an usual subject in an introductory physics course, in order to foster discussions on the nature of physical knowledge. The introduction of elements of the nature of knowledge in physics lessons has been emphasised by many educators and one uses the case of metals to show the theoretical and phenomenological dimensions of physics. The discussion is made by means of four questions whose answers cannot be reached neither for theoretical elements nor experimental measurements. Between these two dimensions it is necessary to realise a series of reasoning steps to deepen the comprehension of microscopic concepts, such as electrical resistivity, drift velocity and free electrons. When this approach is highlighted, beyond the physical content, aspects of its nature become explicit and may improve the structuring of knowledge for learners on this subject.

  12. A Family Resemblance Approach to the Nature of Science for Science Education

    NASA Astrophysics Data System (ADS)

    Irzik, Gürol; Nola, Robert

    2011-07-01

    Although there is universal consensus both in the science education literature and in the science standards documents to the effect that students should learn not only the content of science but also its nature, there is little agreement about what that nature is. This led many science educators to adopt what is sometimes called "the consensus view" about the nature of science (NOS), whose goal is to teach students only those characteristics of science on which there is wide consensus. This is an attractive view, but it has some shortcomings and weaknesses. In this article we present and defend an alternative approach based on the notion of family resemblance. We argue that the family resemblance approach is superior to the consensus view in several ways, which we discuss in some detail.

  13. Approach of background metric expansion to a new metric ansatz for gauged and ungauged Kaluza-Klein supergravity black holes

    NASA Astrophysics Data System (ADS)

    Wu, Shuang-Qing; Wang, He

    2015-05-01

    In a previous paper [S. Q. Wu, Phys. Rev. D 83, 121502(R) (2011)], a new kind of metric ansatz was found to fairly describe all already-known black hole solutions in the ungauged Kaluza-Klein (KK) supergravity theories. That metric ansatz somewhat resembles the famous Kerr-Schild (KS) form, but it is different from the KS one in two distinct aspects. That is, apart from a global conformal factor, the metric ansatz can be written as a vacuum background spacetime plus a "perturbation" modification term, the latter of which is associated with a timelike geodesic vector field rather than a null geodesic congruence in the usual KS ansatz. Replacing the flat vacuum background metric by the (anti-)de Sitter [(A)dS] spacetime, the general rotating charged KK-(A)dS black hole solutions in all higher dimensions have been successfully constructed and put into a unified form. In this paper, we shall study this novel metric ansatz in detail, aiming at achieving some inspiration as to the construction of rotating charged AdS black holes with multiple charges in other gauged supergravity theories. We find that the traditional perturbation expansion method often successfully used in the KS form is no longer useful in our new ansatz, since here no good parameter can be chosen as a suitable perturbation indicator. In order to investigate the metric properties of the general KK-AdS solutions, in this paper we devise a new effective method, dubbed the background metric expansion method, which can be thought of as a generalization of the perturbation expansion method, to deal with the Lagrangian and all equations of motion. In addition to two previously known conditions, namely the timelike and geodesic properties of the vector, we get three additional constraints via contracting the Maxwell and Einstein equations once or twice with this timelike geodesic vector. In particular, we find that these are a simpler set of sufficient conditions to determine the vector and the dilaton scalar

  14. An approach for estimating toxic releases of H2S-containing natural gas.

    PubMed

    Jianwen, Zhang; Da, Lei; Wenxing, Feng

    2014-01-15

    China is well known being rich in sulfurous natural gas with huge deposits widely distributed all over the country. Due to the toxic nature, the release of hydrogen sulfide-containing natural gas from the pipelines intends to impose serious threats to the human, society and environment around the release sources. CFD algorithm is adopted to simulate the dispersion process of gas, and the results prove that Gaussian plume model is suitable for determining the affected region of the well blowout of sulfide hydrogen-containing natural gas. In accordance with the analysis of release scenarios, the present study proposes a new approach for estimating the risk of hydrogen sulfide poisoning hazards, as caused by sulfide-hydrogen-containing natural gas releases. Historical accident-statistical data from the EGIG (European Gas Pipeline Incident Data Group) and the Britain Gas Transco are integrated into the approach. Also, the dose-load effect is introduced to exploit the hazards' effects by two essential parameters - toxic concentration and exposure time. The approach was applied to three release scenarios occurring on the East-Sichuan Gas Transportation Project, and the individual risk and societal risk are classified and discussed. Results show that societal risk varies significantly with different factors, including population density, distance from pipeline, operating conditions and so on. Concerning the dispersion process of hazardous gas, available safe egress time was studied from the perspective of individual fatality risks. The present approach can provide reliable support for the safety management and maintenance of natural gas pipelines as well as evacuations that may occur after release incidents.

  15. A new approach to the definition of seroconversion following vaccination in a population with high background antibody concentrations.

    PubMed

    Chandramohan, Daniel; Coleman, Paul; Nelson, Chris; Greenwood, Brian

    2007-09-03

    Licensure of meningitis vaccines is increasingly being made on the basis of safety and immunogenicity. For meningococcal vaccines, a measure of immunogenicity is seroconversion, usually defined as a four-fold increase in rSBA titre. However, this definition is likely to underestimate seroconversion in settings with high background immunity. Using data from a study of the immunogenicity of meningococcal polysaccharide vaccines undertaken in Ghana, a logistic regression model to estimate the probability of seroconversion as a function of pre-vaccination titre has been developed. The seroconversion rate (91%) based on a variable-fold increase in rSBA titre derived from the model was a more plausible estimate of immunogenicity than the seroconversion rate (32%) based on the fixed four-fold increase in rSBA.

  16. Microcomputer-Based Approaches for Preventing Drug and Alcohol Abuse Among Adolescents from Ethnic-Racial Minority Backgrounds

    PubMed Central

    Moncher, Michael S.; Parms, Clifford A.; Orlandi, Mario A.; Schinke, Steven P.; Miller, Samuel O.; Palleja, Josephine; Schinke, Mary B.

    2006-01-01

    This study was designed to empirically assess the potential of microcomputer-based intervention with black adolescents from economically disadvantaged backgrounds. Subjects were 26, 11 through 14-year-old black females and males recruited from three boroughs in New York City. A sample task was administered via microcomputer system followed by a postintervention measurement battery. Observational measures were also employed to assess interactional variables. Subjects’ attitudes toward educational content in general, and toward drug and alcohol information delivery in particular, appeared to be a significant intervening variable that could alter the overall efficacy of computer-delivered interventions. Both observational and postintervention measures indicated an overall positive subject response to computer-administered instruction. In contrast, however, respondents indicated a negative response to microcomputer delivery of drug and alcohol related materials. Results of the experiment are discussed along with rationales and future research directions. PMID:17387376

  17. Microcomputer-Based Approaches for Preventing Drug and Alcohol Abuse Among Adolescents from Ethnic-Racial Minority Backgrounds.

    PubMed

    Moncher, Michael S; Parms, Clifford A; Orlandi, Mario A; Schinke, Steven P; Miller, Samuel O; Palleja, Josephine; Schinke, Mary B

    1989-01-01

    This study was designed to empirically assess the potential of microcomputer-based intervention with black adolescents from economically disadvantaged backgrounds. Subjects were 26, 11 through 14-year-old black females and males recruited from three boroughs in New York City. A sample task was administered via microcomputer system followed by a postintervention measurement battery. Observational measures were also employed to assess interactional variables. Subjects' attitudes toward educational content in general, and toward drug and alcohol information delivery in particular, appeared to be a significant intervening variable that could alter the overall efficacy of computer-delivered interventions. Both observational and postintervention measures indicated an overall positive subject response to computer-administered instruction. In contrast, however, respondents indicated a negative response to microcomputer delivery of drug and alcohol related materials. Results of the experiment are discussed along with rationales and future research directions.

  18. Environmental geochemistry of shale-hosted Ag-Pb-Zn massive sulfide deposits in northwest Alaska: Natural background concentrations of metals in water from mineralized areas

    USGS Publications Warehouse

    Kelley, K.D.; Taylor, C.D.

    1997-01-01

    Red Dog, Lik and Drenchwater are shale-hosted stratiform Ag-Pb-Zn massive sulfide deposits in the northwestern Brooks Range. Natural background concentrations of metals in waters from the undisturbed (unmined) Drenchwater prospect and Lik deposit were compared to pre-mining baseline studies conducted at Red Dog. The primary factors affecting water chemistry are the extent of exposure of the deposits, the grade of mineralization, the presence of carbonate reeks in the section, and the proportion of Fe-sulfide in the ore. Surface water samples from the Drenchwater prospect, which has pyrite-dominant mineralization exposed in outcrop, have pH values as low as 2.8 and high dissolved concentrations of metals including as much as 95 mg 1-1 Al, 270 mg 1-1 Fe, 8 ??1-1 Cd, 10 ??1-1 Pb, and 2600 ??1-1 Zn, with As up to 26 ??g1-1. Surface waters from the Red Dog deposit prior to mining were also acidic and metal-rich, however, dissolved metal concentrations in Red Dog waters were many times greater. The higher metal concentrations in Red Dog waters reflect the high Zn grades and the abundant sphalerite, pyrite, and galena that were present in outcrop prior to mining. In contrast, despite significant mineralization at the Lik deposit, carbonate rocks in the section buffer the system, resulting in less acidic, mostly near-neutral pH values with low concentrations of most metals except Zn.

  19. Chemical proteomics approaches for identifying the cellular targets of natural products.

    PubMed

    Wright, M H; Sieber, S A

    2016-05-04

    Covering: 2010 up to 2016Deconvoluting the mode of action of natural products and drugs remains one of the biggest challenges in chemistry and biology today. Chemical proteomics is a growing area of chemical biology that seeks to design small molecule probes to understand protein function. In the context of natural products, chemical proteomics can be used to identify the protein binding partners or targets of small molecules in live cells. Here, we highlight recent examples of chemical probes based on natural products and their application for target identification. The review focuses on probes that can be covalently linked to their target proteins (either via intrinsic chemical reactivity or via the introduction of photocrosslinkers), and can be applied "in situ" - in living systems rather than cell lysates. We also focus here on strategies that employ a click reaction, the copper-catalysed azide-alkyne cycloaddition reaction (CuAAC), to allow minimal functionalisation of natural product scaffolds with an alkyne or azide tag. We also discuss 'competitive mode' approaches that screen for natural products that compete with a well-characterised chemical probe for binding to a particular set of protein targets. Fuelled by advances in mass spectrometry instrumentation and bioinformatics, many modern strategies are now embracing quantitative proteomics to help define the true interacting partners of probes, and we highlight the opportunities this rapidly evolving technology provides in chemical proteomics. Finally, some of the limitations and challenges of chemical proteomics approaches are discussed.

  20. Chemical proteomics approaches for identifying the cellular targets of natural products

    PubMed Central

    Sieber, S. A.

    2016-01-01

    Covering: 2010 up to 2016 Deconvoluting the mode of action of natural products and drugs remains one of the biggest challenges in chemistry and biology today. Chemical proteomics is a growing area of chemical biology that seeks to design small molecule probes to understand protein function. In the context of natural products, chemical proteomics can be used to identify the protein binding partners or targets of small molecules in live cells. Here, we highlight recent examples of chemical probes based on natural products and their application for target identification. The review focuses on probes that can be covalently linked to their target proteins (either via intrinsic chemical reactivity or via the introduction of photocrosslinkers), and can be applied “in situ” – in living systems rather than cell lysates. We also focus here on strategies that employ a click reaction, the copper-catalysed azide–alkyne cycloaddition reaction (CuAAC), to allow minimal functionalisation of natural product scaffolds with an alkyne or azide tag. We also discuss ‘competitive mode’ approaches that screen for natural products that compete with a well-characterised chemical probe for binding to a particular set of protein targets. Fuelled by advances in mass spectrometry instrumentation and bioinformatics, many modern strategies are now embracing quantitative proteomics to help define the true interacting partners of probes, and we highlight the opportunities this rapidly evolving technology provides in chemical proteomics. Finally, some of the limitations and challenges of chemical proteomics approaches are discussed. PMID:27098809

  1. New concepts, experimental approaches, and dereplication strategies for the discovery of novel phytoestrogens from natural sources.

    PubMed

    Michel, Thomas; Halabalaki, Maria; Skaltsounis, Alexios-Leandros

    2013-05-01

    Phytoestrogens constitute an attractive research topic due to their estrogenic profile and their biological involvement in woman's health. Therefore, numerous studies are currently performed in natural products chemistry area aiming at the discovery of novel phytoestrogens. The main classes of phytoestrogens are flavonoids (flavonols, flavanones), isoflavonoids (isoflavones, coumestans), lignans, stilbenoids as well as miscellaneous chemical groups abundant in several edible and/or medicinal plants, belonging mostly to the Leguminosae family. As for other bioactives, the detection of new structures and more potent plant-derived phytoestrogens typically follows the general approaches currently available in the natural product discovery process. Plant-based approaches selected from traditional medicine knowledge and bioguided concepts are routinely employed. However, these approaches are associated with serious disadvantages such as time-consuming, repeated, and labor intensive processes as well as lack of specificity and reproducibility. In recent years, the natural products chemistry became more technology-driven, and several different strategies have been developed. Structure-oriented procedures and miniaturized approaches employing advanced hyphenated analytical platforms have recently emerged. They facilitate significantly not only the discovery of novel phytoestrogens but also the dereplication procedure leading to the anticipation of major drawbacks in natural products discovery. In this review, apart from the traditional concepts followed in phytochemistry for the discovery of novel biologically active compounds, recent applications in the field of extraction, analysis, fractionation, and identification of phytoestrogens will be discussed. Moreover, specific methodologies combining identification of actives and biological evaluation in parallel, such as liquid chromatography-biochemical detection, frontal affinity chromatography-mass spectrometry and pulsed

  2. When Should We Use Care Robots? The Nature-of-Activities Approach.

    PubMed

    Santoni de Sio, Filippo; van Wynsberghe, Aimee

    2016-12-01

    When should we use care robots? In this paper we endorse the shift from a simple normative approach to care robots ethics to a complex one: we think that one main task of a care robot ethics is that of analysing the different ways in which different care robots may affect the different values at stake in different care practices. We start filling a gap in the literature by showing how the philosophical analysis of the nature of healthcare activities can contribute to (care) robot ethics. We rely on the nature-of-activities approach recently proposed in the debate on human enhancement, and we apply it to the ethics of care robots. The nature-of-activities approach will help us to understand why certain practice-oriented activities in healthcare should arguably be left to humans, but certain (predominantly) goal-directed activities in healthcare can be fulfilled (sometimes even more ethically) with the assistance of a robot. In relation to the latter, we aim to show that even though all healthcare activities can be considered as practice-oriented, when we understand the activity in terms of different legitimate 'fine-grained' descriptions, the same activities or at least certain components of them can be seen as clearly goal-directed. Insofar as it allows us to ethically assess specific functionalities of specific robots to be deployed in well-defined circumstances, we hold the nature-of-activities approach to be particularly helpful also from a design perspective, i.e. to realize the Value Sensitive Design approach.

  3. A direct approach for instantaneous 3D density field reconstruction from background-oriented schlieren (BOS) measurements

    NASA Astrophysics Data System (ADS)

    Nicolas, F.; Todoroff, V.; Plyer, A.; Le Besnerais, G.; Donjat, D.; Micheli, F.; Champagnat, F.; Cornic, P.; Le Sant, Y.

    2016-01-01

    We present a new numerical method for reconstruction of instantaneous density volume from 3D background-oriented schlieren (3DBOS) measurements, with a validation on a dedicated flexible experimental BOS bench. In contrast to previous works, we use a direct formulation where density is estimated from measured deviation fields without the intermediate step of density gradient reconstruction. Regularization techniques are implemented to deal with the ill-posed problem encountered. The resulting high-dimensional optimization is conducted by conjugate gradient techniques. A parallel algorithm, implemented on graphics processing unit, helps to speed up the calculation. The resulting software is validated on synthetic BOS images of a 3D density field issued from a numerical simulation. Then, we describe a dedicated 3DBOS experimental facility which has been built to study various BOS settings and to assess the performance of the proposed numerical reconstruction process. Results on various datasets illustrate the potential of the method for flow characterization and measurement in real-world conditions.

  4. Inversion Approach to Validate Mercury Emissions Based on Background Air Monitoring at the High Altitude Research Station Jungfraujoch (3580 m).

    PubMed

    Denzler, Basil; Bogdal, Christian; Henne, Stephan; Obrist, Daniel; Steinbacher, Martin; Hungerbühler, Konrad

    2017-03-07

    The reduction of emissions of mercury is a declared aim of the Minamata Convention, a UN treaty designed to protect human health and the environment from adverse effects of mercury. To assess the effectiveness of the convention in the future, better constraints about the current mercury emissions is a premise. In our study, we applied a top-down approach to quantify mercury emissions on the basis of atmospheric mercury measurements conducted at the remote high altitude monitoring station Jungfraujoch, Switzerland. We established the source-receptor relationships and by the means of atmospheric inversion we were able to quantify spatially resolved European emissions of 89 ± 14 t/a for elemental mercury. Our European emission estimate is 17% higher than the bottom-up emission inventory, which is within stated uncertainties. However, some regions with unexpectedly high emissions were identified. Stationary combustion, in particular in coal-fired power plants, is found to be the main responsible sector for increased emission estimates. Our top-down approach, based on measurements, provides an independent constraint on mercury emissions, helps to improve and refine reported emission inventories, and can serve for continued assessment of future changes in emissions independent from bottom-up inventories.

  5. A minimalist fragment approach for the design of natural-product-like synthetic scaffolds.

    PubMed

    Genis, Dmitry; Kirpichenok, Mikhail; Kombarov, Roman

    2012-11-01

    Chemistry groups involved in drug discovery continue to devote their efforts to improving compound design with the aim of identifying new drug candidates. Many crucial factors must be considered, including: chemical stability, synthetic difficulty, chemical complexity and diversity, ADMET properties, cost, chemical novelty and intellectual property issues, and 'biological appropriateness'. With regard to the latter point, natural products offer an outstanding source of biologically active molecules that provide many useful features that enable us to design innovative, biologically biased, synthetic compounds. This article outlines the recent approaches in this area and suggests a simple metric to assess synthetic compounds for natural product likeness.

  6. Exploring the background features of acidic and basic air pollutants around an industrial complex using data mining approach.

    PubMed

    Chen, Ho-Wen; Tsai, Ching-Tsan; She, Chin-Wen; Lin, Yo-Chen; Chiang, Chow-Feng

    2010-11-01

    Air pollution data around a monitored site are normally difficult to analyze due to highly inter-related meteorological and topographical factors on top of many complicated atmospheric chemical interactions occurred in local and regional wind fields. The challenge prompts this study to develop a comprehensive data-mining algorithm of cluster analysis followed by meteorological and interspecies correlations to mitigate the inherent data complexity and dissimilarity. This study investigated the background features of acidic and basic air pollutants around a high-tech industrial park in Taiwan. Monthly samplings were taken at 10 sites around the park in a year. The temporal distribution plots show a baseline with two characteristic groups of high and low peaks. Hierarchical cluster analysis confirms that high peaks were primarily associated with low speed south wind in summer for all the chemical species, except for F(-), Cl(-), NH(3) and HF. Crosschecking with the topographical map identifies several major external sources in south and southwest. Further meteorological correlation suggests that HCl is highly positively associated with humidity, while Cl(-) is highly negatively associated with temperature, both for most stations. Interestingly, HNO(3) is highly negatively associated with wind speed for most stations and the hotspot was found in summer and around the foothill of Da-Tu Mountain in the northwest, a stagnant pocket on the study site. However, F(-) is highly positively associated with wind speed at downwind stations to the prevailing north wind in winter, indicating an internal source from the north. The presence of NH(4)(+) stimulates the formation of NO(3)(-), SO(4)(-2) (R=0.7), and HNO(3), H(2)SO(4), NH(3) (R=0.3-0.4). As H(2)SO(4) could be elevated to a level as high as 40% of the regulated standard, species interactions may be a dominate mechanism responsible for the substantial increase in summer from external sources.

  7. Trace metal variability in coastal waters of San Jorge Bay, Antofagasta, Chile: An environmental evaluation and statistical approach to propose local background levels.

    PubMed

    Valdés, J; Román, D; Guiñez, M; Rivera, L; Ávila, J; Cortés, P; Castillo, A

    2015-11-15

    Between 2008 and 2011, twelve metals from 384 coastal waters samples from San Jorge Bay (Antofagasta, northern Chile) were collected and analyzed. The goal was to evaluate the quality of the bay's water bodies according to the current Chilean Quality Guideline and to establish background levels for these metals. The result suggests that the coastal waters of San Jorge Bay are of very good quality suitable for recreational activities involving human body contact. The natural background thresholds established for this bay were significantly lower than primary and secondary water quality guidelines. The distribution of Cu, Zn and Pb, along the bay's coastline provides evidence of the effects of industrial activity. Both situations suggest that the threshold indicated in the environmental guidelines of the Chilean legislation may be overestimated and do not represent pollution-free environments.

  8. On the nature of heat effects and shear modulus softening in metallic glasses: A generalized approach

    NASA Astrophysics Data System (ADS)

    Kobelev, N. P.; Khonik, V. A.; Makarov, A. S.; Afonin, G. V.; Mitrofanov, Yu. P.

    2014-01-01

    The paper presents a new approach to the nature of heat effects and shear modulus softening in metallic glasses. The approach is based on the assumption that the glass contains quenched-in "defects"—elastic dipoles. Using the nonlinear elastic representation of the internal energy of glass with quenched-in elastic dipoles, we derive a simple analytical law, which connects the heat flow and temperature derivative of the shear modulus. Specially performed experiments confirmed the validity of this law. The exothermal and endothermal heat processes in glass reveal through the relaxation of the shear modulus confirming it as a key parameter for the understanding the relaxation processes in glasses.

  9. Introducing N-glycans into natural products through a chemoenzymatic approach**

    PubMed Central

    Huang, Wei; Ochiai, Hirofumi; Zhang, Xinyu; Wang, Lai-Xi

    2008-01-01

    The present study describes an efficient chemoenzymatic method for introducing a core N-glycan of glycoprotein origin into various lipophilic natural products. It was found that the endo-β-N-acetylglucosaminidase from Arthrobactor protophormiae (Endo-A) had broad substrate specificity and can accommodate a wide range of glucose (Glc)- or N-acetylglucosamine (GlcNAc)-containing natural products as acceptors for transglycosylation, when an N-glycan oxazoline was used as a donor substrate. Using lithocholic acid as a model compound, we have shown that introduction of an N-glycan could be achieved by a two-step approach: chemical glycosylation to introduce a monosaccharide (Glc or GlcNAc) as a handle, and then Endo-A catalyzed transglycosylation to accomplish the site-specific N-glycan attachment. For those natural products that already carry terminal Glc or GlcNAc residues, direct enzymatic transglycosylation using sugar oxazoline as the donor substrate was achievable to introduce an N-glycan. It was also demonstrated that simultaneous double glycosylation could be fulfilled when the natural product contains two Glc residues. This chemoenzymatic method is concise, site-specific, and highly convergent. Because N-glycans of glycoprotein origin can serve as ligands for diverse lectins and cell-surface receptors, introduction of a defined N-glycan into biologically significant natural products may bestow novel properties onto these natural products for drug discovery and development. PMID:18805520

  10. Identifying natural substrates for chaperonins using a sequence-based approach

    PubMed Central

    Stan, George; Brooks, Bernard R.; Lorimer, George H.; Thirumalai, D.

    2005-01-01

    The Escherichia coli chaperonin machinery, GroEL, assists the folding of a number of proteins. We describe a sequence-based approach to identify the natural substrate proteins (SPs) for GroEL. Our method is based on the hypothesis that natural SPs are those that contain patterns of residues similar to those found in either GroES mobile loop and/or strongly binding peptide in complex with GroEL. The method is validated by comparing the predicted results with experimentally determined natural SPs for GroEL. We have searched for such patterns in five genomes. In the E. coli genome, we identify 1422 (about one-third) sequences that are putative natural SPs. In Saccharomyces cerevisiae, 2885 (32%) of sequences can be natural substrates for Hsp60, which is the analog of GroEL. The precise number of natural SPs is shown to be a function of the number of contacts an SP makes with the apical domain (NC) and the number of binding sites (NB) in the oligomer with which it interacts. For known SPs for GroEL, we find ~4 < NC < 5 and 2 ≤ NB ≤ 4. A limited analysis of the predicted binding sequences shows that they do not adopt any preferred secondary structure. Our method also predicts the putative binding regions in the identified SPs. The results of our study show that a variety of SPs, associated with diverse functions, can interact with GroEL. PMID:15576562

  11. A Modeling Approach for Burn Scar Assessment Using Natural Features and Elastic Property

    SciTech Connect

    Tsap, L V; Zhang, Y; Goldgof, D B; Sarkar, S

    2004-04-02

    A modeling approach is presented for quantitative burn scar assessment. Emphases are given to: (1) constructing a finite element model from natural image features with an adaptive mesh, and (2) quantifying the Young's modulus of scars using the finite element model and the regularization method. A set of natural point features is extracted from the images of burn patients. A Delaunay triangle mesh is then generated that adapts to the point features. A 3D finite element model is built on top of the mesh with the aid of range images providing the depth information. The Young's modulus of scars is quantified with a simplified regularization functional, assuming that the knowledge of scar's geometry is available. The consistency between the Relative Elasticity Index and the physician's rating based on the Vancouver Scale (a relative scale used to rate burn scars) indicates that the proposed modeling approach has high potentials for image-based quantitative burn scar assessment.

  12. Omics and Environmental Science Genomic Approaches With Natural Fish Populations From Polluted Environments

    PubMed Central

    Bozinovic, Goran; Oleksiak, Marjorie F.

    2010-01-01

    Transcriptomics and population genomics are two complementary genomic approaches that can be used to gain insight into pollutant effects in natural populations. Transcriptomics identify altered gene expression pathways while population genomics approaches more directly target the causative genomic polymorphisms. Neither approach is restricted to a pre-determined set of genes or loci. Instead, both approaches allow a broad overview of genomic processes. Transcriptomics and population genomic approaches have been used to explore genomic responses in populations of fish from polluted environments and have identified sets of candidate genes and loci that appear biologically important in response to pollution. Often differences in gene expression or loci between polluted and reference populations are not conserved among polluted populations suggesting a biological complexity that we do not yet fully understand. As genomic approaches become less expensive with the advent of new sequencing and genotyping technologies, they will be more widely used in complimentary studies. However, while these genomic approaches are immensely powerful for identifying candidate gene and loci, the challenge of determining biological mechanisms that link genotypes and phenotypes remains. PMID:21072843

  13. Natural inflation: Particle physics models, power-law spectra for large-scale structure, and constraints from the Cosmic Background Explorer

    NASA Astrophysics Data System (ADS)

    Adams, Fred C.; Bond, J. Richard; Freese, Katherine; Frieman, Joshua A.; Olinto, Angela V.

    1993-01-01

    We discuss the particle physics basis for models of natural inflation with pseudo Nambu-Goldstone bosons and study the consequences for large-scale structure of the nonscale-invariant density fluctuation spectra that arise in natural inflation and other models. A pseudo Nambu-Goldstone boson, with a potential of the form V(φ)=Λ4[1+/-cos(φ/f)], can naturally give rise to an epoch of inflation in the early Universe, if f~MPl and Λ~MGUT. Such mass scales arise in particle physics models with a gauge group that becomes strongly interacting at the grand unified theory scale. We work out a specific particle physics example based on the multiple gaugino condensation scenario in superstring theory. We then study the cosmological evolution of and constraints upon these inflation models numerically and analytically. To obtain sufficient inflation with a probability of order 1 and a high enough post-inflation reheat temperature for baryogenesis, we require f>~0.3MPl. The primordial density fluctuation spectrum generated by quantum fluctuations in φ is a non-scale-invariant power law P(k)~kns, with ns~=1-(M2Pl/8πf2) leading to more power on large length scales than the ns=1 Harrison-Zeldovich spectrum. (For the reader primarily interested in large-scale structure, the discussion of this topic is presented in Sec. IV and is intended to be nearly self-contained.) We pay special attention to the prospects of using the enhanced power to explain the otherwise puzzling large-scale clustering of galaxies and clusters and their flows. We find that the standard cold dark matter (CDM) model with 0<~ns<~0.6 could in principle explain these data. However, the microwave background anisotropies recently detected by the Cosmic Background Explorer (COBE) imply such low primordial amplitudes for these CDM models (that is, bias factors b8>~2 for ns<~0.6) that galaxy formation would occur too late to be viable and the large-scale galaxy velocities would be too small. In fact, combining the

  14. Climate impacts on arctic freshwater ecosystems and fisheries: background, rationale and approach of the Arctic Climate Impact Assessment (ACIA).

    PubMed

    Wrona, Frederick J; Prowse, Terry D; Reist, James D; Hobbie, John E; Lévesque, Lucie M J; Vincent, Warwick F

    2006-11-01

    Changes in climate and ultraviolet radiation levels in the Arctic will have far-reaching impacts, affecting aquatic species at various trophic levels, the physical and chemical environment that makes up their habitat, and the processes that act on and within freshwater ecosystems. Interactions of climatic variables, such as temperature and precipitation, with freshwater ecosystems are highly complex and can propagate through the ecosystem in ways that are difficult to project. This is partly due to a poor understanding of arctic freshwater systems and their basic interrelationships with climate and other environmental variables, and partly due to a paucity of long-term freshwater monitoring sites and integrated hydro-ecological research programs in the Arctic. The papers in this special issue are an abstraction of the analyses performed by 25 international experts and their associated networks on Arctic freshwater hydrology and related aquatic ecosystems that was initially published by the Arctic Climate Impact Assessment (ACIA) in 2005 as "Chapter 8--Freshwater Ecosystems and Fisheries". The papers provide a broad overview of the general hydrological and ecological features of the various freshwater ecosystems in the Arctic, including descriptions of each ACIA region, followed by a review of historical changes in freshwater systems during the Holocene. This is followed by an assessment of the effects of climate change on broad-scale hydro-ecology; aquatic biota and ecosystem structure and function; and arctic fish and fisheries. Potential synergistic and cumulative effects are also discussed, as are the roles of ultraviolet radiation and contaminants. The nature and complexity of many of the effects are illustrated using case studies from around the circumpolar north, together with a discussion of important threshold responses (i.e., those that produce stepwise and/or nonlinear effects). The issue concludes with summary the key findings, a list of gaps in

  15. Selection of background electrolyte for CZE analysis by a chemometric approach. Part I. Separation of a mixture of acidic non-steroidal anti-inflammatory drugs.

    PubMed

    Furlanetto, Sandra; Lanteri, Silvia; Orlandini, Serena; Gotti, Roberto; Giannini, Iacopo; Pinzauti, Sergio

    2007-03-12

    This paper is the first part of the presentation of a chemometric approach for the rapid selection of a suitable background electrolyte (BGE) in CZE analysis of small drug molecules. The strategy is based on principal component analysis and experimental design. In this first section, the approach is applied to the analysis of a mixture of six arylpropionic anti-inflammatory drugs. Initially, 222 possible aqueous background electrolytes (objects) were characterized using as descriptors pH, conductivity, ionic strength and relative viscosity. In order to allow the dissociation of the acidic analytes, this original data set was reduced to 154 background electrolytes with pH values higher than or equal to 5. Principal component analysis made it possible to graphically represent the new set of objects, described by the four variables, in a two-dimensional space. Among these electrolytes, Kennard-Stone algorithm selected ten objects to be tested by CZE, covering homogeneously principal component space. CZE analyses were carried out with the selected electrolytes, and 0.1 M borax was identified as the most suitable one for the specified application. Finally, the characteristics of the analysis were finely tuned by means of a response surface study, which allowed the best conditions to be determined: borax concentration, 0.09 M; methanol, 6% (v/v); temperature, 24 degrees C, voltage, 20 kV. Applying these conditions, a baseline resolution among the six compounds was obtained in less than 10 min.

  16. Characterization and Monitoring of Natural Attenuation of Chlorinated Solvents in Ground Water: A Systems Approach

    NASA Astrophysics Data System (ADS)

    Cutshall, N. H.; Gilmore, T.; Looney, B. B.; Vangelas, K. M.; Adams, K. M.; Sink, C. H.

    2006-05-01

    Like many US industries and businesses, the Department of Energy (DOE) is responsible for remediation and restoration of soils and ground water contaminated with chlorinated ethenes. Monitored Natural Attenuation (MNA) is an attractive remediation approach and is probably the universal end-stage technology for removing such contamination. Since 2003 we have carried out a multifaceted program at the Savannah River Site designed to advance the state of the art for MNA of chlorinated ethenes in soils and groundwater. Three lines of effort were originally planned: 1) Improving the fundamental science for MNA, 2) Promoting better characterization and monitoring (CM) techniques, and 3) Advancing the regulatory aspects of MNA management. A fourth line, developing enhanced attenuation methods based on sustainable natural processes, was added in order to deal with sites where the initial natural attenuation capacity cannot offset contaminant loading rates. These four lines have been pursued in an integrated and mutually supportive fashion. Many DOE site-cleanup program managers view CM as major expenses, especially for natural attenuation where measuring attenuation is complex and the most critical attenuation mechanisms cannot be determined directly. We have reviewed new and developing approaches to CM for potential application in support of natural attenuation of chlorinated hydrocarbons in ground water at DOE sites (Gilmore, Tyler, et al., 2006 WSRC-TR- 2005-00199). Although our project is focused on chlorinated ethenes, many of the concepts and strategies are also applicable to a wider range of contaminants including radionuclides and metals. The greatest savings in CM are likely to come from new management approaches. New approaches can be based, for example, on conceptual models of attenuation capacity, the ability of a formation to reduce risks caused by contaminants. Using the mass balance concept as a guide, the integrated mass flux of contaminant is compared to

  17. "It sounds like...": A natural language processing approach to detecting counselor reflections in motivational interviewing.

    PubMed

    Can, Doğan; Marín, Rebeca A; Georgiou, Panayiotis G; Imel, Zac E; Atkins, David C; Narayanan, Shrikanth S

    2016-04-01

    The dissemination and evaluation of evidence-based behavioral treatments for substance abuse problems rely on the evaluation of counselor interventions. In Motivational Interviewing (MI), a treatment that directs the therapist to utilize a particular linguistic style, proficiency is assessed via behavioral coding-a time consuming, nontechnological approach. Natural language processing techniques have the potential to scale up the evaluation of behavioral treatments such as MI. We present a novel computational approach to assessing components of MI, focusing on 1 specific counselor behavior-reflections, which are believed to be a critical MI ingredient. Using 57 sessions from 3 MI clinical trials, we automatically detected counselor reflections in a maximum entropy Markov modeling framework using the raw linguistic data derived from session transcripts. We achieved 93% recall, 90% specificity, and 73% precision. Results provide insight into the linguistic information used by coders to make ratings and demonstrate the feasibility of new computational approaches to scaling up the evaluation of behavioral treatments.

  18. Current approaches and challenges for the metabolite profiling of complex natural extracts.

    PubMed

    Wolfender, Jean-Luc; Marti, Guillaume; Thomas, Aurélien; Bertrand, Samuel

    2015-02-20

    Metabolite profiling is critical in many aspects of the life sciences, particularly natural product research. Obtaining precise information on the chemical composition of complex natural extracts (metabolomes) that are primarily obtained from plants or microorganisms is a challenging task that requires sophisticated, advanced analytical methods. In this respect, significant advances in hyphenated chromatographic techniques (LC-MS, GC-MS and LC-NMR in particular), as well as data mining and processing methods, have occurred over the last decade. Together, these tools, in combination with bioassay profiling methods, serve an important role in metabolomics for the purposes of both peak annotation and dereplication in natural product research. In this review, a survey of the techniques that are used for generic and comprehensive profiling of secondary metabolites in natural extracts is provided. The various approaches (chromatographic methods: LC-MS, GC-MS, and LC-NMR and direct spectroscopic methods: NMR and DIMS) are discussed with respect to their resolution and sensitivity for extract profiling. In addition the structural information that can be generated through these techniques or in combination, is compared in relation to the identification of metabolites in complex mixtures. Analytical strategies with applications to natural extracts and novel methods that have strong potential, regardless of how often they are used, are discussed with respect to their potential applications and future trends.

  19. Some novel approaches for radioprotection and the beneficial effect of natural products.

    PubMed

    Maurya, Dharmendra K; Devasagayam, Thomas P A; Nair, Cherupally Krishnan K

    2006-02-01

    Due to the increased use of ionizing radiation in various aspects of human life especially in areas pertaining to radiotherapy of cancer, food preservation, agriculture, industry and power generation, there is a need to develop an effective and non-toxic radioprotector. The currently available ones have many drawbacks including high cost, side effects and toxicity. Several novel approaches are on to locate a potent radioprotector. These include mimics of antioxidant enzymes, nitroxides, melatonin, growth factors, gene therapy, hyperthermia apart from natural products. The latter has several advantages since they are non-toxic with proven therapeutic benefits. These can be classified as natural compounds and plant extracts; polyherbal formulations; besides natural and semi-natural compounds of plant origin. A review of the above agents, their efficacy in radioprotection and possible mechanisms responsible has been carried out. As India and many Eastern countries have an enormous heritage of vast natural dietary and time tested medicinal resources it is worth exploring the possibility of developing efficient, economically viable and clinically acceptable radioprotectors for human application from these resources.

  20. Learning from nature – novel synthetic biology approaches for biomaterial design

    PubMed Central

    Bryksin, Anton V.; Brown, Ashley C.; Baksh, Michael M.; Finn, M.G.; Barker, Thomas H.

    2014-01-01

    Many biomaterials constructed today are complex chemical structures that incorporate biologically active components derived from nature, but the field can still be said to be in its infancy. The need for materials that bring sophisticated properties of structure, dynamics, and function to medical and non-medical applications will only grow. Increasing appreciation of the functionality of biological systems has caused biomaterials researchers to consider nature for design inspiration, and many examples exist of the use of biomolecular motifs. Yet, evolution, nature's only engine for the creation of new designs, has been largely ignored by the biomaterials community. Molecular evolution is an emerging tool that enables one to apply nature's engineering principles to non-natural situations using variation and selection. The purpose of this review is to highlight the most recent advances in the use of molecular evolution in synthetic biology applications for biomaterial engineering, and to discuss some of the areas in which this approach may be successfully applied in the future. PMID:24463066

  1. "Whoever Does Not Write Is Written": The Role of "Nature" in Post-Post Approaches to Environmental Education Research

    ERIC Educational Resources Information Center

    Russell, Constance L.

    2005-01-01

    While McKenzie mentions in passing her concern about anthropocentrism and human oppression of the natural world, she is mostly silent about the role of "nature" in post-post approaches to environmental education research. If one takes feminist poststructuralist ideas about voice and representation seriously, surely the place of "nature" in…

  2. Ensuring that ecological science contributes to natural resource management using a Delphi-derived approach

    SciTech Connect

    Wolfe, Amy K; Dale, Virginia H; Arthur, Taryn A; Baskaran, Latha Malar

    2017-01-01

    This chapter approaches participatory modeling in environmental decision making from an atypical perspective. It broadly addresses the question of how to assure that science conducted to assist practitioners improves resource management. More specifically, it describes a case involving environmental science and natural resource management at Fort Benning, a U.S. Army installation in the southeastern United States where disparate environmental research projects were funded by a single federal agency to enhance the ability of Fort Benning resource managers to achieve their resource management goals. The role of our effort was to integrate the scientific studies in a manner that would be meaningful and useful for resource managers. Hence we assembled a team consisting of an anthropologist, ecologist, microbiologist, statistician, and geographic information systems specialist who developed a common framework that served as the basis for this integration. The team first used a Delphi expert elicitation, which evolved into an approach more akin to facilitated negotiation. This second approach arose organically, particularly when our team took advantage of an opportunity for face-to-face interaction. Although the shift in our approach was unplanned, it proved to be highly productive. We discuss the potential utility of our approach for other situations and suggest that it would be useful to initiate at the beginning of research where the aim is to produce scientific results that meet practitioners needs, specifically in the realm of environmental science and resource management.

  3. Mapping and valuing ecosystem services as an approach for conservation and natural-resource management.

    PubMed

    Tallis, Heather; Polasky, Stephen

    2009-04-01

    Current approaches to conservation and natural-resource management often focus on single objectives, resulting in many unintended consequences. These outcomes often affect society through unaccounted-for ecosystem services. A major challenge in moving to a more ecosystem-based approach to management that would avoid such societal damages is the creation of practical tools that bring a scientifically sound, production function-based approach to natural-resource decision making. A new set of computer-based models is presented, the Integrated Valuation of Ecosystem Services and Tradeoffs tool (InVEST) that has been designed to inform such decisions. Several of the key features of these models are discussed, including the ability to visualize relationships among multiple ecosystem services and biodiversity, the ability to focus on ecosystem services rather than biophysical processes, the ability to project service levels and values in space, sensitivity to manager-designed scenarios, and flexibility to deal with data and knowledge limitations. Sample outputs of InVEST are shown for two case applications; the Willamette Basin in Oregon and the Amazon Basin. Future challenges relating to the incorporation of social data, the projection of social distributional effects, and the design of effective policy mechanisms are discussed.

  4. Development of Antiatherosclerotic Drugs on the basis of Natural Products Using Cell Model Approach

    PubMed Central

    Orekhov, Alexander N.; Sobenin, Igor A.; Revin, Victor V.; Bobryshev, Yuri V.

    2015-01-01

    Atherosclerosis including its subclinical form is one of the key medical and social problems. At present, there is no therapy available for widespread use against subclinical atherosclerosis. The use of synthetic drugs for the prevention of arteriosclerosis in its early stages is not sufficient because of the limited indications for severe side effects and high cost of treatment. Obviously, effective antiatherosclerotic drugs based on natural products would be a preferred alternative. Simple cell-based models for testing different natural products have been developed and the ability of natural products to prevent intracellular lipid accumulation in primary cell culture was evaluated. This approach utilizing cell models allowed to test effects of such direct antiatherosclerotic therapy, analyzing the effects mimicking those which can occur “at the level” of arterial wall via the inhibition of intracellular lipid deposition. The data from the carried out clinical trials support a point of view that the identification of antiatherosclerotic activity of natural products might offer a great opportunity for the prevention and treatment of atherosclerotic disease, reducing cardiovascular morbidity and mortality. PMID:26347804

  5. An Amphibious Being: How Maritime Surveying Reshaped Darwin's Approach to Natural History.

    PubMed

    Sponsel, Alistair

    2016-06-01

    This essay argues that Charles Darwin's distinctive approach to studying distribution and diversity was shaped by his face-to-face interactions with maritime surveyors during the voyage of H.M.S. Beagle (1831-1836). Introducing their hydrographic surveying methods into natural history enabled him to compare fossil and living marine organisms, to compare sedimentary rocks to present-day marine sediments, and to compare landscapes to submarine topology, thereby realizing Charles Lyell's fanciful ambition for a superior form of geology that might be practiced by an "amphibious being." Darwin's theories of continental uplift, coral reef formation, and the origin of species all depended on his amphibious natural history. This essay contributes to our understanding of theorizing in nineteenth-century natural history by illustrating that specific techniques of observing and collecting could themselves help to generate a particular theoretical orientation and, indeed, that such practical experiences were a more proximate source of Darwin's "Humboldtian" interest in distribution and diversity than Alexander von Humboldt's writings themselves. Darwin's debt to the hydrographers became obscured in two ways: through the "funneling" of credit produced by single-authorship publication in natural history and the "telescoping" of memory by which Darwin's new theories made him recall his former researches as though he had originally undertaken them for the very purpose of producing the later theory.

  6. Ultrasensitive Negative Feedback Control: A Natural Approach for the Design of Synthetic Controllers

    PubMed Central

    Montefusco, Francesco; Akman, Ozgur E.; Soyer, Orkun S.; Bates, Declan G.

    2016-01-01

    Many of the most important potential applications of Synthetic Biology will require the ability to design and implement high performance feedback control systems that can accurately regulate the dynamics of multiple molecular species within the cell. Here, we argue that the use of design strategies based on combining ultrasensitive response dynamics with negative feedback represents a natural approach to this problem that fully exploits the strongly nonlinear nature of cellular information processing. We propose that such feedback mechanisms can explain the adaptive responses observed in one of the most widely studied biomolecular feedback systems—the yeast osmoregulatory response network. Based on our analysis of such system, we identify strong links with a well-known branch of mathematical systems theory from the field of Control Engineering, known as Sliding Mode Control. These insights allow us to develop design guidelines that can inform the construction of feedback controllers for synthetic biological systems. PMID:27537373

  7. Biological and pharmacological approaches to the screening and evaluation of natural products.

    PubMed

    Lahlou, Mouhssen

    2003-01-01

    Many traditional herbal remedies contain active principles, the effects of which can be demonstrated pharmacologically; the biological activity of the whole plant extract is usually related to the constituents that have been identified. Thus, active extracts detected by screening methods are often subjected to more elaborate bioassays to determine their specific pharmacological activity. This paper aims to elucidate the biological, pharmacological and clinical approaches used in the screening of bioactive natural substances. In addition, a scientific process with the goal of finding substances with useful pharmacological activity in plant extracts is rigorously investigated.

  8. Kinetics of natural organic matter (NOM) removal during drinking water biofiltration using different NOM characterization approaches.

    PubMed

    Chen, Fei; Peldszus, Sigrid; Elhadidy, Ahmed M; Legge, Raymond L; Van Dyke, Michele I; Huck, Peter M

    2016-11-01

    To better understand biofiltration, concentration profiles of various natural organic matter (NOM) components throughout a pilot-scale drinking water biofilter were investigated using liquid chromatography - organic carbon detection (LC-OCD) and fluorescence excitation and emission matrices (FEEM). Over a 2 month period, water samples were collected from six ports at different biofilter media depths. Results showed substantial removal of biopolymers (i.e. high molecular weight (MW) NOM components as characterized by LC-OCD) and FEEM protein-like materials, but low removal of humic substances, building blocks and low MW neutrals and low MW acids. For the first time, relative biodegradability of different NOM components characterized by LC-OCD and FEEM approaches were investigated across the entire MW range and for different fluorophore compositions, in addition to establishing the biodegradation kinetics. The removal kinetics for FEEM protein-like materials were different than for the LC-OCD-based biopolymers, illustrating the complementary nature of the LC-OCD and FEEM approaches. LC-OCD biopolymers (both organic carbon and organic nitrogen) and FEEM protein-like materials were shown to follow either first or second order biodegradation kinetics. Due to the low percent removal and small number of data points, the performance of three kinetic models was not distinguishable for humic substances. Pre-filtration of samples for FEEM analyses affected the removal behaviours and/or kinetics especially of protein-like materials which was attributed to the removal of the colloidal/particulate materials.

  9. Discovery and development of natural product-derived chemotherapeutic agents based on a medicinal chemistry approach.

    PubMed

    Lee, Kuo-Hsiung

    2010-03-26

    Medicinal plants have long been an excellent source of pharmaceutical agents. Accordingly, the long-term objectives of the author's research program are to discover and design new chemotherapeutic agents based on plant-derived compound leads by using a medicinal chemistry approach, which is a combination of chemistry and biology. Different examples of promising bioactive natural products and their synthetic analogues, including sesquiterpene lactones, quassinoids, naphthoquinones, phenylquinolones, dithiophenediones, neo-tanshinlactone, tylophorine, suksdorfin, DCK, and DCP, will be presented with respect to their discovery and preclinical development as potential clinical trial candidates. Research approaches include bioactivity- or mechanism of action-directed isolation and characterization of active compounds, rational drug design-based modification and analogue synthesis, and structure-activity relationship and mechanism of action studies. Current clinical trial agents discovered by the Natural Products Research Laboratories, University of North Carolina, include bevirimat (dimethyl succinyl betulinic acid), which is now in phase IIb trials for treating AIDS. Bevirimat is also the first in a new class of HIV drug candidates called "maturation inhibitors". In addition, an etoposide analogue, GL-331, progressed to anticancer phase II clinical trials, and the curcumin analogue JC-9 is in phase II clinical trials for treating acne and in development for trials against prostate cancer. The discovery and development of these clinical trial candidates will also be discussed.

  10. Improved Understanding of Natural System Processes through Coupling of Geophysical Characterization and Numerical Modeling Approaches

    NASA Astrophysics Data System (ADS)

    Hubbard, S.; Williams, K.; Scheibe, T.; Peterson, J.; Chen, J.; Mukhopadhyay, S.; Sonnenthal, E.; Steefel, C.

    2006-12-01

    Numerical modeling of fluid flow and contaminant transport is often used to test hypotheses and to guide resource management. In complex natural systems, challenges are often associated with collecting sufficient information to parameterize numerical models over field relevant scales and with the development of mathematical representations of critical, coupled hydrological-biogeochemical processes. Geophysical methods can be helpful for guiding or constraining numerical models because they can provide extensive information about subsurface properties and processes. Obtaining quantitative parameter estimates from geophysical approaches can also be challenging, however, as these methods do not sample hydrological- biogeochemical properties directly and are often sensitive to various influences.Through a series of lab and field-based case studies, we will explore the benefits and current limitations of using geophysical information in conjunction with hydrological models to interrogate natural systems. We illustrate that where geophysical characterization approaches are sufficiently advanced, they can be useful for guiding model development, providing model parameter input, and for exploring the impact of heterogeneity on flow and transport processes. We also illustrate that where characterization and modeling methods are less well developed, as in the case of advanced subsurface reactive transport models or in the use of geophysical methods for monitoring biogeochemical transformations, comparison of monitoring and modeling information can lead to improvements in the use of both methods as investigative tools.

  11. Phylogeny-guided (meta)genome mining approach for the targeted discovery of new microbial natural products.

    PubMed

    Kang, Hahk-Soo

    2017-02-01

    Genomics-based methods are now commonplace in natural products research. A phylogeny-guided mining approach provides a means to quickly screen a large number of microbial genomes or metagenomes in search of new biosynthetic gene clusters of interest. In this approach, biosynthetic genes serve as molecular markers, and phylogenetic trees built with known and unknown marker gene sequences are used to quickly prioritize biosynthetic gene clusters for their metabolites characterization. An increase in the use of this approach has been observed for the last couple of years along with the emergence of low cost sequencing technologies. The aim of this review is to discuss the basic concept of a phylogeny-guided mining approach, and also to provide examples in which this approach was successfully applied to discover new natural products from microbial genomes and metagenomes. I believe that the phylogeny-guided mining approach will continue to play an important role in genomics-based natural products research.

  12. Rational biosynthetic approaches for the production of new-to-nature compounds in fungi.

    PubMed

    Boecker, Simon; Zobel, Sophia; Meyer, Vera; Süssmuth, Roderich D

    2016-04-01

    Filamentous fungi have the ability to produce a wide range of secondary metabolites some of which are potent toxins whereas others are exploited as food additives or drugs. Fungal natural products still play an important role in the discovery of new chemical entities for potential use as pharmaceuticals. However, in most cases they cannot be directly used as drugs due to toxic side effects or suboptimal pharmacokinetics. To improve drug-like properties, including bioactivity and stability or to produce better precursors for semi-synthetic routes, one needs to generate non-natural derivatives from known fungal secondary metabolites. In this minireview, we describe past and recent biosynthetic approaches for the diversification of fungal natural products, covering examples from precursor-directed biosynthesis, mutasynthesis, metabolic engineering and biocombinatorial synthesis. To illustrate the current state-of-the-art, challenges and pitfalls, we lay particular emphasis on the class of fungal cyclodepsipeptides which have been studied longtime for product diversification and which are of pharmaceutical relevance as drugs.

  13. New approaches for studying the chemical diversity of natural resources and the bioactivity of their constituents.

    PubMed

    Wolfender, Jean-Luc; Queiroz, Emerson Ferreira

    2012-01-01

    Natural products (NPs) have historically been an important source of lead molecules in drug discovery. However, the interest that the pharmaceutical industry has had in NPs has declined in part because of the lack of compatibility of traditional natural-product extract libraries with high-throughput screenings and the low hit rate. Furthermore, in contrast to the synthetic libraries, compounds from natural sources are likely to have complex structures which slow down the identification process and contribute to problems related to supply and manufacturing. In this paper, we summarise some of the strategies that are being developed in our research unit to address these issues. On one hand, differential screening strategies were established with the aim of identifying dynamically induced NPs from silent biosynthetic pathways in plants and fungi that had been exposed to different stress situations. On the other hand, high-resolution HPLC techniques were optimised for biological and chemical profiling of crude extracts. This led to an integrated platform for rapid and efficient identification of new drug-leads and biomarkers of interest that were based on miniaturised technological approaches and metabolomics.

  14. Recent advances in natural product-based anti-biofilm approaches to control infections.

    PubMed

    Buommino, Elisabetta; Scognamiglio, Monica; Donnarumma, Giovanna; Fiorentino, Antonio; D'Abrosca, Brigida

    2014-01-01

    Bacterial biofilms are highly organized surface-associated communities of bacteria encased within an extracellular matrix produced by themselves, capable of growing in connection with different biological or inert surfaces such as artificial joints or catheters. Biofilms are commonly associated with many health problems, such as endocarditis, otitis media, periodontitis, prostatitis, and urinary tract infections. Several bacteria, such as Escherichia coli, Staphylococcus aureus, Streptococcus mutans, and Pseudomonas aeruginosa, or fungal pathogen as Candida albicans, can form biofilms in the body tissues, leading to different infections. The inherently defensive character of the biofilm is demonstrated by enhanced persistence of bacteria grown in the sessile mode respect to bacteria grown planktonically. This makes most biofilm- associated infections difficult to eradicate, thus contributing to disease chronicity. Since natural products provide a diverse array of chemical structures and possess a wide variety of biological properties, natural resources are worldwide exploited in the search of new pharmaceuticals. In this context bioactive secondary metabolites from natural sources, useful for the new antimicrobial and anti-biofilm drugs, are of interest. In this review, the role of small molecules from plants and marine organisms in inhibiting and/or dispersing bacterial biofilms is discussed, as well as the approaches that have been applied to the discovery of lead small molecules that mediate biofilm development. Molecules inhibiting the formation of biofilm may have therapeutic potential. Several candidates, as halogenated furanones, 2-amminoimidazole alkaloids and flavonoids have been already isolated and characterized from many plants and from marine organisms.

  15. Two approaches for incorporating climate change into natural resource management planning at Wind Cave National Park

    USGS Publications Warehouse

    Symstad, Amy; Long, Andrew J.; Stamm, John; King, David A.; Bachelet, Dominque M.; Norton, Parker A.

    2014-01-01

    Wind Cave National Park (WICA) protects one of the world’s longest caves, has large amounts of high quality, native vegetation, and hosts a genetically important bison herd. The park’s relatively small size and unique purpose within its landscape requires hands-on management of these and other natural resources, all of which are interconnected. Anthropogenic climate change presents an added challenge to WICA natural resource management because it is characterized by large uncertainties, many of which are beyond the control of park and National Park Service (NPS) staff. When uncertainty is high and control of this uncertainty low, scenario planning is an appropriate tool for determining future actions. In 2009, members of the NPS obtained formal training in the use of scenario planning in order to evaluate it as a tool for incorporating climate change into NPS natural resource management planning. WICA served as one of two case studies used in this training exercise. Although participants in the training exercise agreed that the scenario planning process showed promise for its intended purpose, they were concerned that the process lacked the scientific rigor necessary to defend the management implications derived from it in the face of public scrutiny. This report addresses this concern and others by (1) providing a thorough description of the process of the 2009 scenario planning exercise, as well as its results and management implications for WICA; (2) presenting the results of a follow-up, scientific study that quantitatively simulated responses of WICA’s hydrological and ecological systems to specific climate projections; (3) placing these climate projections and the general climate scenarios used in the scenario planning exercise in the broader context of available climate projections; and (4) comparing the natural resource management implications derived from the two approaches. Wind Cave National Park (WICA) protects one of the world’s longest caves

  16. Task 23 - background report on subsurface environmental issues relating to natural gas sweetening and dehydration operations. Topical report, February 1, 1994--February 28, 1996

    SciTech Connect

    Sorensen, J.A.

    1998-12-31

    This report describes information pertaining to environmental issues, toxicity, environmental transport, and fate of alkanolamines and glycols associated with natural gas sweetening and dehydration operations. Waste management associated with the operations is also discussed.

  17. How to Use Historical Approach to Teach Nature of Science in Chemistry Education?

    NASA Astrophysics Data System (ADS)

    Tolvanen, Simo; Jansson, Jan; Vesterinen, Veli-Matti; Aksela, Maija

    2014-08-01

    Successful implementation of historical approach to teach nature of science (NOS) requires suitable curriculum material. Several research and development projects have produced lesson plans for science teachers. 25 lesson plans from four different projects involved in creating curriculum material utilizing historical approach in chemistry education were analyzed to describe NOS content included as well as the historical experiments and narratives used. Based on the results of descriptive content analysis of existing curriculum materials, several suggestions on the successful design of lesson plans utilizing historical approach are made. To increase the coherence and clarity of learning objectives and instruction, each lesson plan should focus on the limited amount of specific NOS issues instead of several overtly general NOS aspects. To support explicit classroom discussion on the selected NOS issues, historical narratives used in the lesson plans should illustrate these issues. The lesson plans should also include instructions on how to facilitate classroom discussion, such as questions for students to discuss and reflect. Recommendations are also made concerning the appropriate use of historical experiments and narrative elements such as viewpoint characters and conflicts.

  18. A new approach to the stability analysis of transient natural convection in porous media

    NASA Astrophysics Data System (ADS)

    Tilton, Nils

    2016-11-01

    Onset of natural convection due to transient diffusion in porous media has attracted considerable attention for its applications to CO2 sequestration. Stability analyses typically investigate onset of convection using an initial value problem approach in which a perturbation is introduced to the concentration field at an initial time t =tp . This leads to debate concerning physically appropriate perturbations, the critical time tc for linear instability, and to the counter-intuitive notion of an optimal initial time tp that maximizes perturbation growth. We propose a new approach in which transient diffusion is continuously perturbed by small variations in the porosity. With this approach, instability occurs immediately (tc = 0) without violating any physical constraints, such that the concepts of initial time tp and critical time tc have less relevance. We argue that the onset time for nonlinear convection is a more physically relevant parameter, and show that it can be predicted using a simple asymptotic expansion. Using the expansion, we consider porosity perturbations that vary sinusoidally in the horizontal and vertical directions, and show there are optimal combinations of wavelengths that minimize the onset time of nonlinear convection.

  19. An approach to teaching general chemistry II that highlights the interdisciplinary nature of science.

    PubMed

    Sumter, Takita Felder; Owens, Patrick M

    2011-01-01

    The need for a revised curriculum within the life sciences has been well-established. One strategy to improve student preparation in the life sciences is to redesign introductory courses like biology, chemistry, and physics so that they better reflect their disciplinary interdependence. We describe a medically relevant, context-based approach to teaching second semester general chemistry that demonstrates the interdisciplinary nature of biology and chemistry. Our innovative method provides a model in which disciplinary barriers are diminished early in the undergraduate science curriculum. The course is divided into three principle educational modules: 1) Fundamentals of General Chemistry, 2) Medical Approaches to Inflammation, and 3) Neuroscience as a connector of chemistry, biology, and psychology. We accurately anticipated that this modified approach to teaching general chemistry would enhance student interest in chemistry and bridge the perceived gaps between biology and chemistry. The course serves as a template for context-based, interdisciplinary teaching that lays the foundation needed to train 21st century scientists.

  20. A Bayesian approach to modelling the natural history of a chronic condition from observations with intervention.

    PubMed

    Craig, B A; Fryback, D G; Klein, R; Klein, B E

    1999-06-15

    To assess the costs and benefits of screening and treatment strategies, it is important to know what would have happened had there been no intervention. In today's ethical climate, however, it is almost impossible to observe this directly and therefore must be inferred from observations with intervention. In this paper, we illustrate a Bayesian approach to this situation when the observations are at separated and unequally spaced time points and the time of intervention is interval censored. We develop a discrete-time Markov model which combines a non-homogeneous Markov chain, used to model the natural progression, with mechanisms that describe the possibility of both treatment intervention and death. We apply this approach to a subpopulation of the Wisconsin Epidemiologic Study of Diabetic Retinopathy, a population-based cohort study to investigate prevalence, incidence, and progression of diabetic retinopathy. In addition, posterior predictive distributions are discussed as a prognostic tool to assist researchers in evaluating costs and benefits of treatment protocols. While we focus this approach on diabetic retinopathy cohort data, we believe this methodology can have wide application.

  1. Human-Nature Interaction in the Eastern Pamirs of Tajikistan - Ecosystem services against the background of pasture use and energy consumption

    NASA Astrophysics Data System (ADS)

    Vanselow, K. A.; Samimi, C.; Kraudzun, T.; Kreutzmann, H.

    2012-04-01

    Mountains play an important role in the world's sustainable development. Despite the acquired knowledge about their importance the Global Environment Outlook 3 (UNEP 2002) states that most "mountain commons are ecologically under-managed and suffer from the classic 'commons syndrome': while all seek to benefit, stakeholders lack coordination, incentives and instruments for joint care." For the Eastern Pamirs, a dry (< 100 mm/a) and high (3,500-5,500 m asl) mountain plateau in the east of Tajikistan, grazing and fuel-wood are identified as key ecosystem services. Extensive pastoralism is a prime adapted land use strategy. Therefore, the Soviet administration allocated the production of meat on collective and state farms as the region's main task. Elaborate management plans, usually with four seasonal pasture camps, and additional imports of fuel and forage, led to a well-balanced utilization of all pastures. The dissolution of the USSR resulted in significant structural changes in the region. Most notably, the end of the subsidy system stopped the provisioning from outside. Without external inputs bridging long distances between the seasonal pastures poses a major problem to most smallholders. Furthermore, the limited supply and high cost of imported fossil fuels induced the increased use of dwarf shrubs as an energy resource. However, they are also important forage plants, particularly in winter. This study aims to provide a well-founded overview of the pasture and fuel-wood resources and the spatiotemporal variability of the actual pasture use with associated livestock numbers to make assertions on overuse in particular areas. Therefore, an interdisciplinary approach was used, combining geoecological and socio-economic methods. To assess the pasture potential information about land cover, phytomass availability, and forage quality were collected. Vegetation classes were modeled with a Random Forest (Breiman 2001), based on land cover information of 262 test plots

  2. A Test of the Optimality Approach to Modelling Canopy gas Exchange by Natural Vegetation

    NASA Astrophysics Data System (ADS)

    Schymanski, S. J.; Sivapalan, M.; Roderick, M. L.; Beringer, J.; Hutley, L. B.

    2005-12-01

    Natural vegetation has co-evolved with its environment over a long period of time and natural selection has led to a species composition that is most suited for the given conditions. Part of this adaptation is the vegetation's water use strategy, which determines the amount and timing of water extraction from the soil. Knowing that water extraction by vegetation often accounts for over 90% of the annual water balance in some places, we need to understand its controls if we want to properly model the hydrologic cycle. Water extraction by roots is driven by transpiration from the canopy, which in turn is an inevitable consequence of CO2 uptake for photosynthesis. Photosynthesis provides plants with their main building material, carbohydrates, and with the energy necessary to thrive and prosper in their environment. Therefore we expect that natural vegetation would have evolved an optimal water use strategy to maximise its `net carbon profit' (the difference between carbon acquired by photosynthesis and carbon spent on maintenance of the organs involved in its uptake). Based on this hypothesis and on an ecophysiological gas exchange and photosynthesis model (Cowan and Farquhar 1977; von Caemmerer 2000), we model the optimal vegetation for a site in Howard Springs (N.T., Australia) and compare the modelled fluxes with measurements by Beringer, Hutley et al. (2003). The comparison gives insights into theoretical and real controls on transpiration and photosynthesis and tests the optimality approach to modelling gas exchange of natural vegetation with unknown properties. The main advantage of the optimality approach is that no assumptions about the particular vegetation on a site are needed, which makes it very powerful for predicting vegetation response to long-term climate- or land use change. Literature: Beringer, J., L. B. Hutley, et al. (2003). "Fire impacts on surface heat, moisture and carbon fluxes from a tropical savanna in northern Australia." International

  3. Multi-period natural gas market modeling Applications, stochastic extensions and solution approaches

    NASA Astrophysics Data System (ADS)

    Egging, Rudolf Gerardus

    This dissertation develops deterministic and stochastic multi-period mixed complementarity problems (MCP) for the global natural gas market, as well as solution approaches for large-scale stochastic MCP. The deterministic model is unique in the combination of the level of detail of the actors in the natural gas markets and the transport options, the detailed regional and global coverage, the multi-period approach with endogenous capacity expansions for transportation and storage infrastructure, the seasonal variation in demand and the representation of market power according to Nash-Cournot theory. The model is applied to several scenarios for the natural gas market that cover the formation of a cartel by the members of the Gas Exporting Countries Forum, a low availability of unconventional gas in the United States, and cost reductions in long-distance gas transportation. 1 The results provide insights in how different regions are affected by various developments, in terms of production, consumption, traded volumes, prices and profits of market participants. The stochastic MCP is developed and applied to a global natural gas market problem with four scenarios for a time horizon until 2050 with nineteen regions and containing 78,768 variables. The scenarios vary in the possibility of a gas market cartel formation and varying depletion rates of gas reserves in the major gas importing regions. Outcomes for hedging decisions of market participants show some significant shifts in the timing and location of infrastructure investments, thereby affecting local market situations. A first application of Benders decomposition (BD) is presented to solve a large-scale stochastic MCP for the global gas market with many hundreds of first-stage capacity expansion variables and market players exerting various levels of market power. The largest problem solved successfully using BD contained 47,373 variables of which 763 first-stage variables, however using BD did not result in

  4. Risk Governance of Multiple Natural Hazards: Centralized versus Decentralized Approach in Europe

    NASA Astrophysics Data System (ADS)

    Komendantova, Nadejda; Scolobig, Anna; Vinchon, Charlotte

    2014-05-01

    The multi-risk approach is a relatively new field and its definition includes the need to consider multiple hazards and vulnerabilities in their interdependency (Selva, 2013) and the current multi-hazards disasters, such as the 2011 Tohoku earthquake, tsunami and nuclear catastrophe, showed the need for a multi-risk approach in hazard mitigation and management. Our knowledge about multi-risk assessment, including studies from different scientific disciplines and developed assessment tools, is constantly growing (White et al., 2001). However, the link between scientific knowledge, its implementation and the results in terms of improved governance and decision-making have gained significantly less attention (IRGC, 2005; Kappes et al., 2012), even though the interest to risk governance, in general, has increased significantly during the last years (Verweiy and Thompson, 2006). Therefore, the key research question is how risk assessment is implemented and what is the potential for the implementation of a multi-risk approach in different governance systems across Europe. More precisely, how do the characteristics of risk governance, such as the degree of centralization versus decentralization, influence the implementation of a multi-risk approach. The methodology of this research includes comparative case study analysis of top-down and bottom-up interactions in governance in the city of Naples, (Italy), where the institutional landscape is marked by significant autonomy of Italian regions in decision-making processes for assessing the majority of natural risks, excluding volcanic, and in Guadeloupe, French West Indies, an overseas department of France, where the decision-making process is marked by greater centralization in decision making associated with a well established state governance within regions, delegated to the prefect and decentralised services of central ministries. The research design included documentary analysis and extensive empirical work involving

  5. Design of multifunctional compounds for cardiovascular disease: from natural scaffolds to "classical" multitarget approach.

    PubMed

    Bisi, A; Gobbi, S; Belluti, F; Rampa, A

    2013-01-01

    Cardiovascular disease represents the main cause of death worldwide. Novel therapies to reduce elevated blood pressure and treat resistant hypertension, to consequently reduce the associated cardiovascular risk factors, are still required. Among the different strategies commonly used in medicinal chemistry to develop new molecules, the synthesis of multitarget/hybrid compounds combining two or more pharmacophore groups targeting simultaneously selected factors involved in cardiovascular diseases, has gained increasing interest. This review will focus on the most recent literature on multifunctional cardiovascular drugs, paying particular attention on hybrid compounds bearing natural scaffolds, considering that compounds derived from medicinal extracts are generally appealing for the medicinal chemist as they often bear the so-called "privileged structures". Moreover, taking into account many excellent reviews dealing with multitarget cardiovascular drugs published in the last few years, mainly devoted to RAAS inhibition and/or NO donors hybrid drugs, herein the most significant results obtained and the benefits and limitations of these approaches will be highlighted.

  6. Improvements in chronic diseases with a comprehensive natural medicine approach: a review and case series.

    PubMed

    Nader, T; Rothenberg, S; Averbach, R; Charles, B; Fields, J Z; Schneider, R H

    2000-01-01

    Approximately 40% of the US population report using complementary and alternative medicine, including Maharishi Vedic Medicine (MVM), a traditional, comprehensive system of natural medicine, for relief from chronic and other disorders. Although many reports suggest health benefits from individual MVM techniques, reports on integrated holistic approaches are rare. This case series, designed to investigate the effectiveness of an integrated, multimodality MVM program in an ideal clinical setting, describes the outcomes in four patients: one with sarcoidosis; one with Parkinson's disease; a third with renal hypertension; and a fourth with diabetes/essential hypertension/anxiety disorder. Standard symptom reports and objective markers of disease were evaluated before, during, and after the treatment period. Results suggested substantial improvements as indicated by reductions in major signs, symptoms, and use of conventional medications in the four patients during the 3-week in-residence treatment phase and continuing through the home follow-up program.

  7. Multiphoton ionization and circular dichroism: new experimental approach and application to natural products.

    PubMed

    Logé, Christoph; Boesl, Ulrich

    2011-07-11

    Enantio-sensitive laser mass spectrometry is the combination of multiphoton ionization by circularly polarized laser light with mass spectrometric detection of ions. The method has been developed as a tool for the fast investigation of chiral molecules in sample mixtures without any preceding separation and offers many new experimental possibilities. The main difficulties of the detection of circular dichroism in this way arise from systematic and statistical deviations. Herein, we report the newest approach to overcome these problems using a so-called twin-peak ion source, back-reflection of the laser light, and reference substances. By these means, the detection limit for circular dichroism can be lowered from the percent to the per-mill range. The capabilities of the new setup are demonstrated by the investigation of several natural products.

  8. Improvements in Chronic Diseases With a Comprehensive Natural Medicine Approach: A Review and Case Series

    PubMed Central

    Nader, Tony; Rothenberg, Stuart; Averbach, Richard; Charles, Barry; Fields, Jeremy Z.; Schneider, Robert H.

    2008-01-01

    Approximately 40% of the US population report using complementary and alternative medicine, including Maharishi Vedic Medicine (MVM), a traditional, comprehensive system of natural medicine, for relief from chronic and other disorders. Although many reports suggest health benefits from individual MVM techniques, reports on integrated holistic approaches are rare. This case series, designed to investigate the effectiveness of an integrated, multi-modality MVM program in an ideal clinical setting, describes the outcomes in four patients: one with sarcoidosis; one with Parkinson’s disease; a third with renal hypertension; and a fourth with diabetes/essential hypertension/anxiety disorder. Standard symptom reports and objective markers of disease were evaluated before, during, and after the treatment period. Results suggested substantial improvements as indicated by reductions in major signs, symptoms, and use of conventional medications in the four patients during the 3-week in-residence treatment phase and continuing through the home follow-up program. PMID:10971882

  9. Evolutionary genetics in wild primates: combining genetic approaches with field studies of natural populations

    PubMed Central

    Tung, Jenny; Alberts, Susan C; Wray, Gregory A

    2010-01-01

    Ecological and evolutionary studies of wild primates hold important keys to understanding both the shared characteristics of primate biology and the genetic and phenotypic differences that make specific lineages, including our own, unique. Although complementary genetic research on nonhuman primates has long been of interest, recent technological and methodological advances now enable functional and population genetic studies in an unprecedented manner. In the past several years, novel genetic data sets have revealed new information about the demographic history of primate populations and the genetics of adaptively important traits. In combination with the rich history of behavioral, ecological, and physiological work on natural primate populations, genetic approaches promise to provide a compelling picture of primate evolution in the past and in the present day. PMID:20580115

  10. A cultural neuroscience approach to the biosocial nature of the human brain.

    PubMed

    Han, Shihui; Northoff, Georg; Vogeley, Kai; Wexler, Bruce E; Kitayama, Shinobu; Varnum, Michael E W

    2013-01-01

    Cultural neuroscience (CN) is an interdisciplinary field that investigates the relationship between culture (e.g., value and belief systems and practices shared by groups) and human brain functions. In this review we describe the origin, aims, and methods of CN as well as its conceptual framework and major findings. We also clarify several misunderstandings of CN research. Finally, we discuss the implications of CN findings for understanding human brain function in sociocultural contexts and novel questions that future CN research should address. By doing so, we hope to provide a clear picture of the CN approach to the human brain and culture and to elucidate the intrinsically biosocial nature of the functional organization of the human brain.

  11. A novel modelling approach for evaluating the preindustrial natural carrying capacity of human population in Iceland.

    PubMed

    Haraldsson, Hörour V; Olafsdóttir, Rannveig

    2006-12-15

    The pre-industrial natural carrying capacity is believed to have limited the human population in Iceland to a maximum of fifty to sixty thousand inhabitants. Since AD 1800 the Icelandic population has gradually grown up to nearly 300 thousand in 2005. In this paper a simple approach is used to evaluate the potential population size that the pre-industrial Icelandic environment could possibly sustain. A dynamic model was constructed that simulates the population size according to potential biological production available for livestock. Biological production was determined by the extent of the total potential vegetation cover based on the Degree-Day concept. Fluctuations in the mean annual temperature causes changes in the potential vegetation cover and as a consequence change the biological production sustaining livestock and ultimately human population. The simulation's results indicate that the potential population that the Icelandic environments could sustain during the pre-industrial period fluctuated between 40 and 80 thousand. The results further indicate that the severe land degradation experienced after the Viking settlement period in AD 900 had a marginal impact on the population size. The pre-historical population did however overshoot the natural sustainability on several occasions.

  12. Turn on the super-elastic collision nature of coronal mass ejections through low approaching speed.

    PubMed

    Shen, Fang; Wang, Yuming; Shen, Chenglong; Feng, Xueshang

    2016-01-21

    It has been proved from the observations and numerical simulations that the collision between solar coronal mass ejections (CMEs), the largest plasmoids in the heliosphere, could be super-elastic. This finding suggests that the CMEs' magnetic energy and thermal energy could be converted into kinetic energy through a more efficient way. However CME collisions are not always super-elastic, which means that this distinct property of plasmoids is probably excited conditionally. As the first attempt, we carry out a series of three-dimensional numerical experiments, and establish a diagram showing the dependence of the collision nature on the CME speed and k-number, the ratio of the CME's kinetic energy to the CME's total energy. It is found that the super-elastic nature of CMEs appears at the relatively low approaching speed, and most of the previous case studies are in agreement with this diagram. Our study firmly advances the understanding of the super-elastic property of plasmoids, and does give us new clues to deeply understand why and how the magnetic energy and/or thermal energy of the colliding plasmoids can be converted into kinetic energy in such an efficient way.

  13. Natural Organic Matter Transport Modeling with a Continuous Time Random Walk Approach

    PubMed Central

    McInnis, Daniel P.; Bolster, Diogo; Maurice, Patricia A.

    2014-01-01

    Abstract In transport experiments through columns packed with naturally Fe/Al oxide-coated quartz sand, breakthrough curves (BTCs) of natural organic matter (NOM) displayed strong and persistent power law tailing that could not be described by the classical advection–dispersion equation. Tailing was not observed in BTCs for a nonreactive tracer (sulforhodamine B); therefore, the anomalous transport is attributed to diverse adsorptive behavior of the polydisperse NOM sample rather than to physical heterogeneity of the porous medium. NOM BTC tailing became more pronounced with decreases in pH and increases in ionic strength, conditions previously shown to be associated with enhanced preferential adsorption of intermediate to high molecular weight NOM components. Drawing from previous work on anomalous solute transport, we develop an approach to model NOM transport within the framework of a continuous time random walk (CTRW) and show that under all conditions examined, the CTRW model is able to capture tailing of NOM BTCs by accounting for differences in transport rates of NOM fractions through a distribution of effective retardation factors. These results demonstrate the importance of considering effects of adsorptive fractionation on NOM mobility, and illustrate the ability of the CTRW model to describe transport of a multicomponent solute. PMID:24596449

  14. Structure elucidation and DNA binding specificity of natural compounds from Cassia siamea leaves: A biophysical approach.

    PubMed

    Parveen, Mehtab; Ahmad, Faheem; Malla, Ali Mohammed; Khan, Mohd Sohrab; Rehman, Sayeed Ur; Tabish, Mohammad; Silva, Manuela Ramos; Silva, P S Pereira

    2016-06-01

    A novel isoflavone, 5,6,7-trimethoxy-3-(3',4',5'-trimethoxyphenyl)-4H-chromen-4-one (1) along with a known pyranocoumarin, Seselin (2) have been isolated from the ethanolic extract of the leaves of Cassia siamea (Family: Fabaceae). Compound 1 has been reported for the first time from any natural source and has not been synthesized so far. Their structures were elucidated on the basis of chemical and physical evidences viz. elemental analysis, UV, FT-IR, (1)H-NMR, (13)C-NMR and mass spectral analysis. Structure of compound (1) was further authenticated by single-crystal X-ray analysis and density functional theory (DFT) calculations. A multi-technique approach employing UV-Visible spectroscopy, fluorescence, KI quenching studies, competitive displacement assay, circular dichroism and viscosity studies have been utilized to probe the extent of interaction and possible binding modes of isolated compounds (1-2) with calf thymus DNA (CT-DNA). Both the compounds were found to interact with DNA via non-intercalative binding mode with moderate proficiencies. Groove binding was the major interaction mode in the case of compound 2 while compound 1 probably interacts with DNA through electrostatic interactions. These studies provide deeper insight in understanding of DNA-drug (natural products) interaction which could be helpful to improve their bioavailability for therapeutic purposes.

  15. Turn on the super-elastic collision nature of coronal mass ejections through low approaching speed

    PubMed Central

    Shen, Fang; Wang, Yuming; Shen, Chenglong; Feng, Xueshang

    2016-01-01

    It has been proved from the observations and numerical simulations that the collision between solar coronal mass ejections (CMEs), the largest plasmoids in the heliosphere, could be super-elastic. This finding suggests that the CMEs’ magnetic energy and thermal energy could be converted into kinetic energy through a more efficient way. However CME collisions are not always super-elastic, which means that this distinct property of plasmoids is probably excited conditionally. As the first attempt, we carry out a series of three-dimensional numerical experiments, and establish a diagram showing the dependence of the collision nature on the CME speed and k-number, the ratio of the CME’s kinetic energy to the CME’s total energy. It is found that the super-elastic nature of CMEs appears at the relatively low approaching speed, and most of the previous case studies are in agreement with this diagram. Our study firmly advances the understanding of the super-elastic property of plasmoids, and does give us new clues to deeply understand why and how the magnetic energy and/or thermal energy of the colliding plasmoids can be converted into kinetic energy in such an efficient way. PMID:26791543

  16. The Nature of Elementary Student Science Discourse in the Context of the Science Writing Heuristic Approach

    NASA Astrophysics Data System (ADS)

    Cavagnetto, Andy; Hand, Brian M.; Norton-Meier, Lori

    2010-03-01

    This case study aimed to determine the nature of student interactions in small groups in an elementary classroom utilizing the Science Writing Heuristic approach. Fifth grade students were audio-recorded over four units of study while working in small groups to generate knowledge claims after conducting student-directed investigations. Analysis consisted of (1) identifying amount of on/off task talk, (2) categorizing on-task talk as generative (talk associated with generating an argument) or representational (talk associated with representing an argument in a final written form), (3) characterizing the generative components of argument, and (4) determining the functions of language used. Results indicate that students were on task 98% of the time. Students engaged in generative talk an average of 25% of the time and representational talk an average of 71% of the time. Students engaged in components of Toulmin's model of argument, but challenging of each other's ideas was not commonplace. Talk was dominated by the informative function (representing one's ideas) of language as it was found 78.3% of the time and to a lesser extent (11.7%) the heuristic function (inquiring through questions). These functions appear to be intimately tied to the task of generating knowledge claims in small groups. The results suggest that both talking and writing are critical to using science discourse as an embedded strategy to learning science. Further, nature and structure of the task are important pedagogical considerations when moving students toward participation in science discourse.

  17. Current advances in the development of natural meniscus scaffolds: innovative approaches to decellularization and recellularization.

    PubMed

    Chen, Yunbin; Chen, Jiaxin; Zhang, Zeng; Lou, Kangliang; Zhang, Qi; Wang, Shengyu; Ni, Jinhu; Liu, Wenyue; Fan, Shunwu; Lin, Xianfeng

    2017-03-31

    The increasing rate of injuries to the meniscus indicates the urgent need to develop effective repair strategies. Irreparably damaged menisci can be replaced and meniscus allografts represent the treatment of choice; however, they have several limitations, including availability and compatibility. Another approach is the use of artificial implants but their chondroprotective activities are still not proved clinically. In this situation, tissue engineering offers alternative natural decellularized extracellular matrix (ECM) scaffolds, which have shown biomechanical properties comparable to those of native menisci and are characterized by low immunogenicity and promising regenerative potential. In this article, we present an overview of meniscus decellularization methods and discuss their relative merits. In addition, we comparatively evaluate cell types used to repopulate decellularized scaffolds and analyze the biocompatibility of the existing experimental models. At present, acellular ECM hydrogels, as well as slices and powders, have been explored, which seems to be promising for partial meniscus regeneration. However, their inferior biomechanical properties (compressive and tensile stiffness) compared to natural menisci should be improved. Although an optimal decellularized meniscus scaffold still needs to be developed and thoroughly validated for its regenerative potential in vivo, we believe that decellularized ECM scaffolds are the future biomaterials for successful structural and functional replacement of menisci.

  18. Overview of the Enhanced Natural Gestures Instructional Approach and Illustration of Its Use with Three Students with Angelman Syndrome

    ERIC Educational Resources Information Center

    Calculator, Stephen; Diaz-Caneja Sela, Patricia

    2015-01-01

    Background: This investigation details procedures used to teach enhanced natural gestures (ENGs) and illustrates its use with three students with Angelman syndrome (AS). Materials and Methods: Themes were extracted, using a process of content analysis, to organize individuals' feedback pertaining to previous versions of the instructional…

  19. The Effect of Explicit-Reflective and Historical Approach on Preservice Elementary Teachers' Views of Nature of Science

    ERIC Educational Resources Information Center

    Pekbay, Canay; Yilmaz, Serkan

    2015-01-01

    This study aims to explore the influence of nature of science (NOS) activities based on explicit-reflective and historical approach on preservice elementary teachers' views of NOS aspects. Mixed-method approach including both qualitative and quantitative methods was used. The sample consisted of 83 preservice elementary teachers of a public…

  20. Resolving the chemical nature of nanodesigned silica surface obtained via a bottom-up approach.

    PubMed

    Rahma, Hakim; Buffeteau, Thierry; Belin, Colette; Le Bourdon, Gwenaëlle; Degueil, Marie; Bennetau, Bernard; Vellutini, Luc; Heuzé, Karine

    2013-08-14

    The covalent grafting on silica surfaces of a functional dendritic organosilane coupling agent inserted, in a long alkyl chain monolayer, is described. In this paper, we show that depending on experimental parameters, particularly the solvent, it is possible to obtain a nanodesigned surface via a bottom-up approach. Thus, we succeed in the formation of both homogeneous dense monolayer and a heterogeneous dense monolayer, the latter being characterized by a nanosized volcano-type pattern (4-6 nm of height, 100 nm of width, and around 3 volcanos/μm(2)) randomly distributed over the surface. The dendritic attribute of the grafted silylated coupling agent affords enough anchoring sites to immobilize covalently functional gold nanoparticles (GNPs), coated with amino PEG polymer to resolve the chemical nature of the surfaces and especially the volcano type nanopattern structures of the heterogeneous monolayer. Thus, the versatile surface chemistry developed herein is particularly challenging as the nanodesign is straightforward achieved in a bottom-up approach without any specific lithography device.

  1. Sensorimotor event: an approach to the dynamic, embodied, and embedded nature of sensorimotor cognition

    PubMed Central

    Vilarroya, Oscar

    2014-01-01

    In this paper, I explore the notion of sensorimotor event as the building block of sensorimotor cognition. A sensorimotor event is presented here as a neurally controlled event that recruits those processes and elements that are necessary to address the demands of the situation in which the individual is involved. The notion of sensorimotor event is intended to subsume the dynamic, embodied, and embedded nature of sensorimotor cognition, in agreement with the satisficing and bricoleur approach to sensorimotor cognition presented elsewhere (Vilarroya, 2012). In particular, the notion of sensorimotor event encompasses those relevant neural processes, but also those bodily and environmental elements, that are necessary to deal with the situation in which the individual is involved. This continuum of neural processes as well as bodily and environmental elements can be characterized, and this characterization is considered the basis for the identification of the particular sensorimotor event. Among other consequences, the notion of sensorimotor event suggests a different approach to the classical account of sensory-input mapping onto a motor output. Instead of characterizing how a neural system responds to an external input, the idea defended here is to characterize how system-in-an-environment responds to its antecedent situation. PMID:24427133

  2. CHARACTERIZATION AND MONITORING OF NATURAL ATTENUATION OF CHLORINATED SOLVENTS IN GROUNDWATER: A SYSTEMS APPROACH

    SciTech Connect

    Looney, B; Michael Heitkamp, M; Gary Wein , G; Christopher Bagwell, C; Karen Vangelas, K; Karen-M Adams, K; Tyler Gilmore; Norman Cutshall; David Major; Mike Truex; Todd Wiedemeier; Francis H. Chapelle; Tom Early; Jody Waugh; David Peterson; Mark Ankeny; Claire H. Sink

    2006-08-10

    The objective of this document is to examine the use of a phased approach to characterizing and monitoring (C&M) natural attenuation processes and enhanced attenuation processes and to identify promising tools and techniques by which to accomplish the C&M. We will investigate developing techniques, such as molecular-based assessment tools, and existing tools that traditionally have not been used for monitoring the performance of environmental remediation technologies. Case studies will be used to provide examples of how non-traditional methods are being employed as characterization and monitoring tools to support MNA and EA. The document is not focused on a specific group of readers but rather is broadly directed with the intent that readers may gain information useful to their purposes. Thus, regulators may see some future characterization and monitoring techniques; end users may find novel ways to make MNA or EA more effective or efficient at their site; researchers may identify new areas for development or new and better combinations of existing methods. One consequence of this broad approach is that some readers may find certain sections either too rudimentary or too advanced for their needs. Hopefully, all will be able to use at least some of the document.

  3. Investigating the Relationship between Test-Taker Background Characteristics and Test Performance in a Heterogeneous English-as-a-Second-Language (ESL) Test Population: A Factor Analytic Approach. Research Report. ETS RR-15-25

    ERIC Educational Resources Information Center

    Manna, Venessa F.; Yoo, Hanwook

    2015-01-01

    This study examined the heterogeneity in the English-as-a-second-language (ESL) test population by modeling the relationship between test-taker background characteristics and test performance as measured by the "TOEFL iBT"® using a confirmatory factor analysis (CFA) with covariate approach. The background characteristics studied…

  4. Naturalizing Sense of Agency with a Hierarchical Event-Control Approach

    PubMed Central

    Kumar, Devpriya; Srinivasan, Narayanan

    2014-01-01

    Unraveling the mechanisms underlying self and agency has been a difficult scientific problem. We argue for an event-control approach for naturalizing the sense of agency by focusing on the role of perception-action regularities present at different hierarchical levels and contributing to the sense of self as an agent. The amount of control at different levels of the control hierarchy determines the sense of agency. The current study investigates this approach in a set of two experiments using a scenario containing multiple agents sharing a common goal where one of the agents is partially controlled by the participant. The participant competed with other agents for achieving the goal and subsequently answered questions on identification (which agent was controlled by the participant), the degree to which they are confident about their identification (sense of identification) and the degree to which the participant believed he/she had control over his/her actions (sense of authorship). Results indicate a hierarchical relationship between goal-level control (higher level) and perceptual-motor control (lower level) for sense of agency. Sense of identification ratings increased with perceptual-motor control when the goal was not completed but did not vary with perceptual-motor control when the goal was completed. Sense of authorship showed a similar interaction effect only in experiment 2 that had only one competing agent unlike the larger number of competing agents in experiment 1. The effect of hierarchical control can also be seen in the misidentification pattern and misidentification was greater with the agent affording greater control. Results from the two studies support the event-control approach in understanding sense of agency as grounded in control. The study also offers a novel paradigm for empirically studying sense of agency and self. PMID:24642834

  5. Three approaches to investigating the multidimensional nature of a science assessment

    NASA Astrophysics Data System (ADS)

    Gokiert, Rebecca Jayne

    The purpose of this study was to investigate a multi-method approach for collecting validity evidence about the underlying knowledge and skills measured by a large-scale science assessment. The three approaches included analysis of dimensionality, differential item functioning (DIF), and think-aloud interviews. The specific research questions addressed were: (1) Does the 4-factor model previously found by Hamilton et al. (1995) for the grade 8 sample explain the data? (2) Do the performances of male and female students systematically differ? Are these performance differences captured in the dimensions? (3) Can think-aloud reports aid in the generation of hypotheses about the underlying knowledge and skills that are measured by this test? A confirmatory factor analysis of the 4-factor model revealed good model data fit for both the AB and AC tests. Twenty-four of the 83 AB test items and 16 of the 77 AC test items displayed significant DIF, however, items were found, on average, to favour both males and females equally. There were some systematic differences found across the 4-factors; items favouring males tended to be related to earth and space sciences, stereotypical male related activities, and numerical operations. Conversely, females were found to outperform males on items that required careful reading and attention to detail. Concurrent and retrospective verbal reports (Ericsson & Simon, 1993) were collected from 16 grade 8 students (9 male and 7 female) while they solved 12 DIF items. Four general cognitive processing themes were identified from the student protocols that could be used to explain male and female problem solving. The themes included comprehension (verbal and visual), visualization, background knowledge/experience (school or life), and strategy use. There were systematic differences in cognitive processing between the students that answered the items correctly and the students who answered the items incorrectly; however, this did not always

  6. Raman scattering study of background electron density in InN: a hydrodynamical approach to the LO-phonon-plasmon coupled modes.

    PubMed

    Cuscó, R; Alarcón-Lladó, E; Ibáñez, J; Yamaguchi, T; Nanishi, Y; Artús, L

    2009-10-14

    We use a hydrodynamical approach to analyse the long-wavelength LO-phonon-plasmon coupled modes observed in a set of high-quality MBE-grown InN epilayers with electron densities varying over one order of magnitude, from ∼2 × 10(18) to ∼2 × 10(19)  cm(-3). The samples were characterized by scanning electron microscopy, x-ray diffraction and Hall measurements. The correlation observed between the E(2)(high) mode frequency, and hence residual strain, and the electron density measured in the layers indicates that the differences in background electron density may be associated with threading dislocations. Owing to the low Raman signal, only the L(-) branch of the coupled modes can be unambiguously observed. The frequency of the L(-) Raman peak is, however, sensitive enough to the free electron density to allow its determination from lineshape fits to the spectra. These were carried out using an extended hydrodynamical model. Given the small bandgap energy and large conduction band nonparabolicity of InN, suitable expressions for the optical effective mass and mean square velocity that enter the hydrodynamical model were derived. Electron density values extracted from L(-) lineshape fits agree reasonably well with Hall determinations.

  7. Synergistic approach for treatment of chicken coccidiosis using berberine--A plant natural product.

    PubMed

    Malik, Tauseef Ahmad; Kamili, Azra N; Chishti, M Z; Tanveer, Syed; Ahad, Shazia; Johri, R K

    2016-04-01

    Despite the advent of anticoccidial drugs and vaccines, coccidiosis continues to result in substantial economic losses to the poultry industry. Berberine, a natural alkaloid is well known in studies involving synergistic approaches, thereby reducing the dosage of principal drugs. Therefore, a study was designed to see whether a synergistic anticoccidial effect could be obtained between amprolium and berberine, in vivo using broiler chicken. Anticoccidial activity was measured in comparison to the reference drug amprolium on the basis of oocyst output reduction, mean weight gain and feed conversion ratio. Oocyst output was measured using Mc-Masters counting technique. Different combinations of berberine and amprolium were tested and out of which 1:1 ratio was the most effective for controlling these parasites. Oral gavaging of 100(50 + 50) mg/kg body weight of 1:1 ratio of amprolium and berberine caused the equivalent reduction in number of oocysts (38.85 ± 9.61) one day prior to that of standard drug amprolium (49.95 ± 16.65) as well as pure berberine (44.4 ± 9.61) used in the study. Weight gain of birds was also highest in the synergistic group (1547.43 ± 12.86) among all the infected groups. Besides feed conversion ratio in the synergistic group was also better (1.387 ± 0.026). The results of this study proved the effectiveness of both amprolium and berberine and revealed synergism between amprolium and berberine against coccidian oocysts, confirmed by significant reduction in the number of coccidian oocysts shed in the feces, leading to better weight gain and improved feed conversion ratio. The study deep-rooted the synergistic potential of berberine, a natural bioactive compound for controlling a protozoan parasite and the results of this study corroborate with its use for treatment of severe diarrhoea, amoebiasis and intestinal infections.

  8. A natural approach to extended Newtonian gravity: tests and predictions across astrophysical scales

    NASA Astrophysics Data System (ADS)

    Mendoza, S.; Hernandez, X.; Hidalgo, J. C.; Bernal, T.

    2011-02-01

    In the pursuit of a general formulation for a modified gravitational theory at the non-relativistic level and as an alternative to the dark matter hypothesis, we construct a model valid over a wide variety of astrophysical scales. Through the inclusion of Milgrom's acceleration constant into a gravitational theory, we show that very general formulae can be constructed for the acceleration felt by a particle. Dimensional analysis shows that this inclusion naturally leads to the appearance of a mass-length scale in gravity, breaking its scale invariance. A particular form of the modified gravitational force is constructed and tested for consistency with observations over a wide range of astrophysical environments, from Solar system to extragalactic scales. We show that over any limited range of physical parameters, which define a specific class of astrophysical objects, the dispersion velocity of a system must be a power law of its mass and size. These powers appear linked together through a natural constraint relation of the theory. This yields a generalized gravitational equilibrium relation valid for all astrophysical systems. A general scheme for treating spherical symmetrical density distributions is presented, which in particular shows that the Fundamental Plane of elliptical galaxies, the Newtonian virial equilibrium, the Tully-Fisher and the Faber-Jackson relations, as well as the scalings observed in local dwarf spheroidal galaxies, are nothing but particular cases of that relation when applied to the appropriate mass-length scales. We discuss the implications of this approach for a modified theory of gravity and emphasize the advantages of working with the force, instead of altering Newton's second law of motion, in the formulation of a gravitational theory.

  9. A global approach to analysis and interpretation of metabolic data for plant natural product discovery†

    PubMed Central

    Hur, Manhoi; Campbell, Alexis Ann; Almeida-de-Macedo, Marcia; Li, Ling; Ransom, Nick; Jose, Adarsh; Crispin, Matt; Nikolau, Basil J.

    2013-01-01

    Discovering molecular components and their functionality is key to the development of hypotheses concerning the organization and regulation of metabolic networks. The iterative experimental testing of such hypotheses is the trajectory that can ultimately enable accurate computational modelling and prediction of metabolic outcomes. This information can be particularly important for understanding the biology of natural products, whose metabolism itself is often only poorly defined. Here, we describe factors that must be in place to optimize the use of metabolomics in predictive biology. A key to achieving this vision is a collection of accurate time-resolved and spatially defined metabolite abundance data and associated metadata. One formidable challenge associated with metabolite profiling is the complexity and analytical limits associated with comprehensively determining the metabolome of an organism. Further, for metabolomics data to be efficiently used by the research community, it must be curated in publically available metabolomics databases. Such databases require clear, consistent formats, easy access to data and metadata, data download, and accessible computational tools to integrate genome system-scale datasets. Although transcriptomics and proteomics integrate the linear predictive power of the genome, the metabolome represents the nonlinear, final biochemical products of the genome, which results from the intricate system(s) that regulate genome expression. For example, the relationship of metabolomics data to the metabolic network is confounded by redundant connections between metabolites and gene-products. However, connections among metabolites are predictable through the rules of chemistry. Therefore, enhancing the ability to integrate the metabolome with anchor-points in the transcriptome and proteome will enhance the predictive power of genomics data. We detail a public database repository for metabolomics, tools and approaches for statistical

  10. A global approach to analysis and interpretation of metabolic data for plant natural product discovery.

    PubMed

    Hur, Manhoi; Campbell, Alexis Ann; Almeida-de-Macedo, Marcia; Li, Ling; Ransom, Nick; Jose, Adarsh; Crispin, Matt; Nikolau, Basil J; Wurtele, Eve Syrkin

    2013-04-01

    Discovering molecular components and their functionality is key to the development of hypotheses concerning the organization and regulation of metabolic networks. The iterative experimental testing of such hypotheses is the trajectory that can ultimately enable accurate computational modelling and prediction of metabolic outcomes. This information can be particularly important for understanding the biology of natural products, whose metabolism itself is often only poorly defined. Here, we describe factors that must be in place to optimize the use of metabolomics in predictive biology. A key to achieving this vision is a collection of accurate time-resolved and spatially defined metabolite abundance data and associated metadata. One formidable challenge associated with metabolite profiling is the complexity and analytical limits associated with comprehensively determining the metabolome of an organism. Further, for metabolomics data to be efficiently used by the research community, it must be curated in publicly available metabolomics databases. Such databases require clear, consistent formats, easy access to data and metadata, data download, and accessible computational tools to integrate genome system-scale datasets. Although transcriptomics and proteomics integrate the linear predictive power of the genome, the metabolome represents the nonlinear, final biochemical products of the genome, which results from the intricate system(s) that regulate genome expression. For example, the relationship of metabolomics data to the metabolic network is confounded by redundant connections between metabolites and gene-products. However, connections among metabolites are predictable through the rules of chemistry. Therefore, enhancing the ability to integrate the metabolome with anchor-points in the transcriptome and proteome will enhance the predictive power of genomics data. We detail a public database repository for metabolomics, tools and approaches for statistical analysis

  11. Integrated Metabolomics Approach Facilitates Discovery of an Unpredicted Natural Product Suite from Streptomyces coelicolor M145

    PubMed Central

    Sidebottom, Ashley M.; Johnson, Andrew R.; Karty, Jonathan A.; Trader, Darci J.; Carlson, Erin E.

    2013-01-01

    Natural products exhibit a broad range of biological properties and have been a crucial source of therapeutic agents and novel scaffolds. Although bacterial secondary metabolomes are widely explored, they remain incompletely cataloged by current isolation and characterization strategies. To identify metabolites residing in unexplored chemical space, we have developed an integrated discovery approach that combines bacterial growth perturbation, accurate mass spectrometry, comparative mass spectra data analysis, and fragmentation spectra clustering for the identification of low-abundant, novel compounds from complex biological matrices. In this investigation, we analyzed the secreted metabolome of the extensively studied Actinomycete, Streptomyces coelicolor M145, and discovered a low-abundant suite of 15 tri-hydroxamate, amphiphilic siderophores. Compounds in this class have primarily been observed in marine microorganisms making their detection in the soil-dwelling S. coelicolor M145 significant. At least ten of these ferrioxamine-based molecules are not known to be produced by any organism and none have previously been detected from S. coelicolor M145. In addition, we confirmed the production of ferrioxamine D1, a relatively hydrophilic family member that has not been shown to be biosynthesized by this organism. The identified molecules are part of only a small list of secondary metabolites that have been discovered since sequencing of S. coelicolor M145 revealed that it possessed numerous putative secondary metabolite-producing gene clusters with no known metabolites. Thus, the identified siderophores represent the unexplored metabolic potential of both well-studied and new organisms that could be uncovered with our sensitive and robust approach. PMID:23777274

  12. Natural killer cells and neuroblastoma: tumor recognition, escape mechanisms, and possible novel immunotherapeutic approaches.

    PubMed

    Bottino, Cristina; Dondero, Alessandra; Bellora, Francesca; Moretta, Lorenzo; Locatelli, Franco; Pistoia, Vito; Moretta, Alessandro; Castriconi, Roberta

    2014-01-01

    Neuroblastoma (NB) is the most common extra-cranial solid tumor of childhood and arises from developing sympathetic nervous system. Most primary tumors localize in the abdomen, the adrenal gland, or lumbar sympathetic ganglia. Amplification in tumor cells of MYCN, the major oncogenic driver, patients' age over 18 months, and the presence at diagnosis of a metastatic disease (stage IV, M) identify NB at high risk of treatment failure. Conventional therapies did not significantly improve the overall survival of these patients. Moreover, the limited landscape of somatic mutations detected in NB is hampering the development of novel pharmacological approaches. Major efforts aim to identify novel NB-associated surface molecules that activate immune responses and/or direct drugs to tumor cells and tumor-associated vessels. PVR (Poliovirus Receptor) and B7-H3 are promising targets, since they are expressed by most high-risk NB, are upregulated in tumor vasculature and are essential for tumor survival/invasiveness. PVR is a ligand of DNAM-1 activating receptor that triggers the cytolytic activity of natural killer (NK) cells against NB. In animal models, targeting of PVR with an attenuated oncolytic poliovirus induced tumor regression and elimination. Also B7-H3 was successfully targeted in preclinical studies and is now being tested in phase I/II clinical trials. B7-H3 down-regulates NK cytotoxicity, providing NB with a mechanism of escape from immune response. The immunosuppressive potential of NB can be enhanced by the release of soluble factors that impair NK cell function and/or recruitment. Among these, TGF-β1 modulates the cytotoxicity receptors and the chemokine receptor repertoire of NK cells. Here, we summarize the current knowledge on the main cell surface molecules and soluble mediators that modulate the function of NK cells in NB, considering the pros and cons that must be taken into account in the design of novel NK cell-based immunotherapeutic approaches.

  13. NATURAL RADIOACTIVITY LEVEL AND ELEMENTAL COMPOSITION OF SOIL SAMPLES FROM A HIGH BACKGROUND RADIATION AREA ON EASTERN COAST OF INDIA (ODISHA).

    PubMed

    Sahoo, S K; Kierepko, R; Sorimachi, A; Omori, Y; Ishikawa, T; Tokonami, S; Prasad, G; Gusain, G S; Ramola, R C

    2016-10-01

    A comprehensive study was carried out to determine the radioactivity concentration of soil samples from different sites of a high background radiation area in the eastern coast of India, Odisha state. The dose rate measured in situ varied from 0.25 to 1.2 µSv h(-1) The gamma spectrometry measurements indicated Th series elements as the main contributors to the enhanced level of radiation and allowed the authors to find the mean level of the activity concentration (±SD) for (226)Ra, (228)Th and (40)K as 130±97, 1110±890 and 360±140 Bq kg(-1), respectively. Human exposure from radionuclides occurring outdoor was estimated based on the effective dose rate, which ranged from 0.14±0.02 to 2.15±0.26 mSv and was higher than the UNSCEAR annual worldwide average value 0.07 mSv. Additionally, X-ray fluorescence analysis provided information about the content of major elements in samples and indicated the significant amount of Ti (7.4±4.9 %) in soils.

  14. Numerical study of natural convection within a wavy enclosure using meshfree approach: effect of corner heating.

    PubMed

    Singh, Sonam; Bhargava, R

    2014-01-01

    This paper presents a numerical study of natural convection within a wavy enclosure heated via corner heating. The considered enclosure is a square enclosure with left wavy side wall. The vertical wavy wall of the enclosure and both of the corner heaters are maintained at constant temperature, T c and T h , respectively, with T h > T c while the remaining horizontal, bottom, top and side walls are insulated. A penalty element-free Galerkin approach with reduced gauss integration scheme for penalty terms is used to solve momentum and energy equations over the complex domain with wide range of parameters, namely, Rayleigh number (Ra), Prandtl number (Pr), and range of heaters in the x- and y-direction. Numerical results are represented in terms of isotherms, streamlines, and Nusselt number. It is observed that the rate of heat transfer depends to a great extent on the Rayleigh number, Prandtl number, length of the corner heaters and the shape of the heat transfer surface. The consistent performance of the adopted numerical procedure is verified by comparison of the results obtained through the present meshless technique with those existing in the literature.

  15. Two different approaches in skin cancer therapy: using a photosensitizer/a natural product

    NASA Astrophysics Data System (ADS)

    Abraham, Annie; Gayathri, Devi D.; Cibin, T. R.; Ramaiah, D.

    2010-02-01

    This paper deals with two potential modes for the treatment of skin cancer-one a novel approach using a squaraine dye and the other using a natural product- the flavonoid fraction of Saraca asoka. Squaraine dye is a photosensitizing agent, which is preferentially taken up and retained by the tumor cells and when irradiated with high power visible light results in the selective destruction of the tumor cells by photodynamic therapy. The uniqueness of this mode of treatment lies in the selective destruction of tumor cells without affecting the neighbouring normal cells, which is much advantageous over radiation therapy now frequently used. The chemopreventive and therapeutic effects of the plant component are explored as well. The experimental models were Swiss albino mice in which skin tumor was induced by DMBA. Marked reduction in tumor volume and burden in the treated groups were observed. The reversal of biochemical enzyme markers like rhodanese, myeloperoxidase, β-D glucuronidase, lactate dehydrogenase, hexokinase and sialic acid to near normal levels were observed in the PDT and flavonoid fraction treated groups. The live photographs of the experimental animals and histopathological data further support the obtained results. The study assumes importance as it combines a traditional treatment mode and a novel aspect in cancer therapy using the same experimental models. Also this is the first report on PDT using a squaraine dye for skin cancer therapy in vivo.

  16. Discover natural compounds as potential phosphodiesterase-4B inhibitors via computational approaches.

    PubMed

    Li, Jing; Zhou, Nan; Liu, Wen; Li, Jianzong; Feng, Yu; Wang, Xiaoyun; Wu, Chuanfang; Bao, Jinku

    2016-05-01

    cAMP, intracellular cyclic adenosine monophosphate, is a ubiquitous second messenger that plays a key role in many physiological processes. PDE4B which can reduce the cAMP level by hydrolyzing cAMP to 5'-AMP has become a therapeutic target for the treatment of human diseases such as respiratory disorders, inflammation diseases, neurological and psychiatric disorders. However, the use of currently available PDE4B inhibitors is restricted due to serious side effects caused by targeting PDE4D. Hence, we are attempting to find out subfamily-selective PDE4B inhibitors from natural products, using computer-aided approaches such as virtual screening, docking, and molecular dynamics simulation. Finally, four potential PDE4B-selective inhibitors (ZINC67912770, ZINC67912780, ZINC72320169, and ZINC28882432) were found. Compared to the reference drug (roflumilast), they scored better during the virtual screening process. Binding free energy for them was -317.51, -239.44, -215.52, and -165.77 kJ/mol, better than -129.05 kJ/mol of roflumilast. The pharmacophore model of the four candidate inhibitors comprised six features, including one hydrogen bond donor, four hydrogen bond acceptors, and one aromatic ring feature. It is expected that our study will pave the way for the design of potent PDE4B-selective inhibitors of new drugs to treat a wide variety of diseases such as asthma, COPD, psoriasis, depression, etc.

  17. Numerical Study of Natural Convection within a Wavy Enclosure Using Meshfree Approach: Effect of Corner Heating

    PubMed Central

    Singh, Sonam; Bhargava, R.

    2014-01-01

    This paper presents a numerical study of natural convection within a wavy enclosure heated via corner heating. The considered enclosure is a square enclosure with left wavy side wall. The vertical wavy wall of the enclosure and both of the corner heaters are maintained at constant temperature, Tc and Th, respectively, with Th > Tc while the remaining horizontal, bottom, top and side walls are insulated. A penalty element-free Galerkin approach with reduced gauss integration scheme for penalty terms is used to solve momentum and energy equations over the complex domain with wide range of parameters, namely, Rayleigh number (Ra), Prandtl number (Pr), and range of heaters in the x- and y-direction. Numerical results are represented in terms of isotherms, streamlines, and Nusselt number. It is observed that the rate of heat transfer depends to a great extent on the Rayleigh number, Prandtl number, length of the corner heaters and the shape of the heat transfer surface. The consistent performance of the adopted numerical procedure is verified by comparison of the results obtained through the present meshless technique with those existing in the literature. PMID:24672383

  18. Theoretical simulations on the antioxidant mechanism of naturally occurring flavonoid: A DFT approach

    NASA Astrophysics Data System (ADS)

    Praveena, R.; Sadasivam, K.

    2016-05-01

    Synthetic antioxidants such as butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) are found to be toxic, hence non-carcinogenic naturally occurring radical scavengers especially flavonoids have gained considerable importance in the past two decades. In the present investigation, the radical scavenging activity of C-glycosyl flavonoids is evaluated using theoretical approach which could broaden its scope in therapeutic applications. Gas and solvent phase studies of structural and molecular characteristics of C-glycosyl flavonoid, isovitexin is investigated through hydrogen atom transfer mechanism (HAT), Electron transfer-proton transfer (ET-PT) and Sequential proton loss electron transfer (SPLET) by Density functional theory (DFT) using hybrid parameters. The computed values of the adiabatic ionization potential, electron affinity, hardness, softness, electronegativity and electrophilic index indicate that isovitexin possess good radical scavenging activity. The behavior of different -OH groups in polyphenolic compounds is assessed by considering electronic effects of the neighbouring groups and the overall geometry of molecule which in turn helps in analyzing the antioxidant capacity of the polyphenolic molecule. The studies indicate that the H-atom abstraction from 4'-OH site is preferred during the radical scavenging process. From Mulliken spin density analysis and FMOs, B-ring is found to be more delocalized center and capable of electron donation. Comparison of antioxidant activity of vitexin and isovitexin leads to the conclusion that isovitexin acts as a better radical scavenger. This is an evidence for the importance of position of glucose unit in the flavonoid.

  19. The Performance of Available Approaches for Quantifying Airborne Exposure to Asbestos Generated from Natural Deposits

    NASA Astrophysics Data System (ADS)

    Berman, D.

    2012-12-01

    General options for quantifying airborne (exposure) concentrations to asbestos include (1) direct measurement, (2) simulation, and (3) emission/dispersion modeling (of measured asbestos concentrations in the source material). Suitable options for particular applications depend on whether one is evaluating current or future and short-term episodic or long-term average exposures. Moreover, because the character and the magnitude of exposure must both be determined for many applications, methods suitable for air- or bulk-phase measurements must exhibit appropriate performance. After all, it is only when we understand precisely what exposure estimates represent that we can interpret them meaningfully. What is known about the suitability and performance of various options for quantifying asbestos exposures generated from natural deposits will be reviewed in this talk with particular emphasis on an approach in which emission and dispersion of asbestos-containing dusts are modeled from bulk-phase measurements collected using the modified elutriator method (a method designed explicitly for this particular application).

  20. Investigating variations in background response in measurements of downhole natural gamma in a banded iron formation in the Pilbara, Western Australia

    NASA Astrophysics Data System (ADS)

    Murphy, Richard J.; Silversides, Katherine L.

    2017-02-01

    Measurements of downhole natural gamma radiation (NGR) provide important information about the location of shale or clay bands within stratigraphical sequences (e.g. in Banded Iron Formations; BIF). An ability to link NGR with other kinds of measurements that are acquired at greater spatial and stratigraphic resolution, such as those acquired by hyperspectral sensing, would open up possibilities for improving the resolution of boundary models. To do this, measurements made by NGR and hyperspectral sensing must be highly correlated and any inconsistencies between these data must be understood. Observations made from the literature and from NGR measurements made in a BIF formation of the Hamersley Group, Pilbara, Western Australia, suggest that NGR measurements in some sections of ore or BIF are elevated compared with other sections; laboratory assays of drill chips do not however suggest the presence of shale or clay. These apparent inconsistencies were investigated using hyperspectral measurements and chemical assays of rock cores in the laboratory and NGR measurements made in the field. We show that the patterns of elevated NGR were a consistent feature of the stratigraphy for this region. Comparison of NGR and Al2O3 made by laboratory assay and from hyperspectral sensing show that elevated NGR measurements were caused by Uranium which was not associated with the presence of shale. Neither Thorium nor Potassium contributed to the elevated gamma signal in the ore. Thorium was strongly correlated with Al2O3 and was found to provide the best indicator of the presence of shale in the stratigraphy.

  1. Taming the Wild: Approaches to Nature in Japanese Early Childhood Education

    ERIC Educational Resources Information Center

    Burke, Rachael S.

    2014-01-01

    The Japanese early childhood curriculum provides ample opportunities for children to interact with nature and to learn about natural phenomena. However, using Kalland (1995) and Martinez's (2008) theories about Japanese constructions of nature, this paper argues that most Japanese early childhood experiences do not constitute direct contact with…

  2. The Concept of Human Nature in Three Cultures: A Developmental Approach.

    ERIC Educational Resources Information Center

    Oerter, Rolf

    This study compares the concept of human nature in Germany, Java, and the United States. The study assumes cross-cultural similarities in the formal structure of the concept of human nature, while hypothesizing variation in content, for example, in the value systems. Four components of the concept of human nature were presented (personality…

  3. A simplified approach for solving coagulation-diffusion equation to estimate atmospheric background particle number loading factors contributed by emissions from localized sources

    NASA Astrophysics Data System (ADS)

    Anand, S.; Mayya, Y. S.

    2011-08-01

    Coagulation and condensation/evaporation combined with atmospheric dispersion are the main processes responsible for the evolution of aerosol particle size distributions and number concentrations emitted from localized sources. A crucial question is: what fraction of freshly emitted particles survive intra-coagulation effect to persist in the atmosphere and become available for further interaction with background aerosols?. The difficulty in estimating this quantity, designated as the number survival fraction, arises due chiefly to the joint action of atmospheric diffusion with nonlinear coagulation effects which are computationally intensive to handle. We provide a simplified approach to evaluate this quantity in the context of instantaneous (puff) and continuous (plume) releases based on a reduction of the respective coagulation-diffusion equations under the assumption of a constant coagulation kernel ( K). The condensation/evaporation processes, being number conserving, are not included in the study. The approach consists of constructing moment equations for the evolution of number concentration and variance of the spatial extension of puff or plume in terms of either time or downstream distance. The puff model, applicable to instantaneous releases is solved within a 3-D, spherically symmetric framework, under an additional assumption of a constant diffusion coefficient ( D) which renders itself amenable to a closed form solution that provides a benchmark for developing the solution to the plume model. The latter case, corresponding to continuous releases, is discussed within a 2-D framework under the assumptions of constant advection velocity ( U) and space dependent diffusion coefficient expressed in terms of turbulent energy dissipation rate ( ɛ). The study brings out the special effect of the coagulation-induced flattening of the spatial concentration profiles because of which particle sizes will be larger at the centre of a Gaussian puff. For a puff of

  4. UNCOVERING THE WAVE NATURE OF THE EIT WAVE FOR THE 2010 JANUARY 17 EVENT THROUGH ITS CORRELATION TO THE BACKGROUND MAGNETOSONIC SPEED

    SciTech Connect

    Zhao, X. H.; Feng, X. S.; Jiang, C. W.; Wu, S. T.; Wang, A. H.; Vourlidas, A. E-mail: wus@uah.edu

    2011-12-01

    An EIT wave, which typically appears as a diffuse brightening that propagates across the solar disk, is one of the major discoveries of the Extreme ultraviolet Imaging Telescope on board the Solar and Heliospheric Observatory. However, the physical nature of the so-called EIT wave continues to be debated. In order to understand the relationship between an EIT wave and its associated coronal wave front, we investigate the morphology and kinematics of the coronal mass ejection (CME)-EIT wave event that occurred on 2010 January 17. Using the observations of the SECCHI EUVI, COR1, and COR2 instruments on board the Solar Terrestrial Relations Observation-B, we track the shape and movements of the CME fronts along different radial directions to a distance of about 15 solar radii (R{sub s} ); for the EIT wave, we determine the propagation of the wave front on the solar surface along different propagating paths. The relation between the EIT wave speed, the CME speed, and the local fast-mode characteristic speed is also investigated. Our results demonstrate that the propagation of the CME front is much faster than that of the EIT wave on the solar surface, and that both the CME front and the EIT wave propagate faster than the fast-mode speed in their local environments. Specifically, we show a significant positive correlation between the EIT wave speed and the local fast-mode wave speed in the propagation paths of the EIT wave. Our findings support that the EIT wave under study is a fast-mode magnetohydrodynamic wave.

  5. Mapping Natural Terroir Units using a multivariate approach and legacy data

    NASA Astrophysics Data System (ADS)

    Priori, Simone; Barbetti, Roberto; L'Abate, Giovanni; Bucelli, Piero; Storchi, Paolo; Costantini, Edoardo A. C.

    2014-05-01

    Natural Terroir Unit (NTU) is a volume of earth's biosphere that is characterized by a stable set of variables related to the topography, climate, geology and soil. Methods to study the association soil-climate-vines are numerous, but the main question is always: which variables are actually important for the quality and the typicality of grapevines, and then wine, for a particular scale? This work aimed to setting up a multivariate methodology to define viticultural terroirs at the province scale (1:125,000), using viticultural and oenological legacy data. The study area was the Siena province in the Tuscany region (Central Italy). The reference grapevine cultivar was "Sangiovese", which is the most important cultivar of the region. The methodology was based upon the creation of a GIS storing several viticultural and oenological legacy data of 55 experimental vineyards (vintages between 1989-2009), the long term climate data, the digital elevation model, the soil-landscapes (land systems) and the soil profiles with the soil analysis. The selected viticultural and oenological parameters were: must sugar content, sugar accumulation rate from veraison to harvest, must titratable acidity, grape yield per vine, number of bunches for vine, mean bunch weight, and mean weight of berries. The environmental parameters related to viticulture, selected by an explorative PCA, were: elevation, mean annual temperature, mean soil temperature, annual precipitation, clay, sand and gravel content of soils, soil water availability, redoximorphic features and rooting depth. The geostatistical models of the variables interpolation were chosen on the best of mean standardize error, obtained by the cross-validation, between "Simple cokriging with varying local mean", "Multicollocated simple cokriging with varying local mean" and "Regression kriging". These variables were used for a k-means clustering aimed to map the Natural Terroirs Units (NTUs). The viticultural areas of Siena province

  6. Tailoring online information retrieval to user's needs based on a logical semantic approach to natural language processing and UMLS mapping.

    PubMed

    Kossman, Susan; Jones, Josette; Brennan, Patricia Flatley

    2007-10-11

    Depression can derail teenagers' lives and cause serious chronic health problems. Acquiring pertinent knowledge and skills supports care management, but retrieving appropriate information can be difficult. This poster presents a strategy to tailor online information to user attributes using a logical semantic approach to natural language processing (NLP) and mapping propositions to UMLS terms. This approach capitalizes on existing NLM resources and presents a potentially sustainable plan for meeting consumers and providers information needs.

  7. Insightful monitoring of natural flood risk management features using a low-cost and participatory approach

    NASA Astrophysics Data System (ADS)

    Starkey, Eleanor; Barnes, Mhari; Quinn, Paul; Large, Andy

    2016-04-01

    Pressures associated with flooding and climate change have significantly increased over recent years. Natural Flood Risk Management (NFRM) is now seen as being a more appropriate and favourable approach in some locations. At the same time, catchment managers are also encouraged to adopt a more integrated, evidence-based and bottom-up approach. This includes engaging with local communities. Although NFRM features are being more readily installed, there is still limited evidence associated with their ability to reduce flood risk and offer multiple benefits. In particular, local communities and land owners are still uncertain about what the features entail and how they will perform, which is a huge barrier affecting widespread uptake. Traditional hydrometric monitoring techniques are well established but they still struggle to successfully monitor and capture NFRM performance spatially and temporally in a visual and more meaningful way for those directly affected on the ground. Two UK-based case studies are presented here where unique NFRM features have been carefully designed and installed in rural headwater catchments. This includes a 1km2 sub-catchment of the Haltwhistle Burn (northern England) and a 2km2 sub-catchment of Eddleston Water (southern Scotland). Both of these pilot sites are subject to prolonged flooding in winter and flash flooding in summer. This exacerbates sediment, debris and water quality issues downstream. Examples of NFRM features include ponds, woody debris and a log feature inspired by the children's game 'Kerplunk'. They have been tested and monitored over the 2015-2016 winter storms using low-cost techniques by both researchers and members of the community ('citizen scientists'). Results show that monitoring techniques such as regular consumer specification time-lapse cameras, photographs, videos and 'kite-cams' are suitable for long-term and low-cost monitoring of a variety of NFRM features. These techniques have been compared against

  8. Hanford Site background: Part 1, Soil background for nonradioactive analytes. Revision 1, Volume 1

    SciTech Connect

    Not Available

    1993-04-01

    The determination of soil background is one of the most important activities supporting environmental restoration and waste management on the Hanford Site. Background compositions serve as the basis for identifying soil contamination, and also as a baseline in risk assessment processes used to determine soil cleanup and treatment levels. These uses of soil background require an understanding of the extent to which analytes of concern occur naturally in the soils. This report documents the results of sampling and analysis activities designed to characterize the composition of soil background at the Hanford Site, and to evaluate the feasibility for use as Sitewide background. The compositions of naturally occurring soils in the vadose Zone have been-determined for-nonradioactive inorganic and organic analytes and related physical properties. These results confirm that a Sitewide approach to the characterization of soil background is technically sound and is a viable alternative to the determination and use of numerous local or area backgrounds that yield inconsistent definitions of contamination. Sitewide soil background consists of several types of data and is appropriate for use in identifying contamination in all soils in the vadose zone on the Hanford Site. The natural concentrations of nearly every inorganic analyte extend to levels that exceed calculated health-based cleanup limits. The levels of most inorganic analytes, however, are well below these health-based limits. The highest measured background concentrations occur in three volumetrically minor soil types, the most important of which are topsoils adjacent to the Columbia River that are rich in organic carbon. No organic analyte levels above detection were found in any of the soil samples.

  9. Complementary Approaches to Teaching Nature of Science: Integrating Student Inquiry, Historical Cases, and Contemporary Cases in Classroom Practice

    ERIC Educational Resources Information Center

    Allchin, Douglas; Andersen, Hanne Moller; Nielsen, Keld

    2014-01-01

    Research has now demonstrated that students can learn nature of science concepts variously through student-led investigations, contemporary cases, and historical cases. Here we articulate more precisely the merits, deficits, and context of each approach and begin to profile how to integrate them as complementary methods. Emphasis now needs to…

  10. Do Pre-Service Science Teachers Have Understanding of the Nature of Science?: Explicit-Reflective Approach

    ERIC Educational Resources Information Center

    Örnek, Funda; Turkey, Kocaeli

    2014-01-01

    Current approaches in Science Education attempt to enable students to develop an understanding of the nature of science, develop fundamental scientific concepts, and develop the ability to structure, analyze, reason, and communicate effectively. Students pose, solve, and interpret scientific problems, and eventually set goals and regulate their…

  11. Sacred Places in Nature: A Unitive Theme for a Transpersonal Approach to Environmental Education.

    ERIC Educational Resources Information Center

    Swan, Jim

    1983-01-01

    Provides background information on and development and use of mental imagery exercises in environmental education. The exercises are designed to help people make contact with those symbolic forms which then actualize certain aspects of their personality. (JN)

  12. Metagenomic Approaches to Natural Products from Free-Living and Symbiotic Organisms

    PubMed Central

    Brady, Sean F.; Simmons, Luke; Kim, Jeff H.; Schmidt, Eric W.

    2010-01-01

    Bacterial cultivation has been a mainstay of natural products discovery for the past 80 years. However, the majority of bacteria are recalcitrant to culture, providing an untapped source for new natural products. Metagenomic analysis provides an alternative method to directly access the uncultivated genome for natural products research and for the discovery of novel, bioactive substances. Applications of metagenomics to diverse habitats, such as soils and the interior of animals, are described. PMID:19844642

  13. From Sequential Extraction to Transport Modeling, Monitored Natural Attenuation as a Remediation Approach for Inorganic Contaminants

    SciTech Connect

    POWELL, KIMBERLYR.

    2004-05-25

    Implementation of monitored natural attenuation (MNA) as a remediation method requires a mechanistic understanding of the natural attenuation processes occurring at a given site. For inorganic contaminants, natural attenuation typically involves a decrease in metal toxicity and/or mobility. These natural processes include dilution, dispersion, sorption (including adsorption, absorption, and precipitation), and redox processes. In order to better quantify these processes in terms of metal availability, sequential extraction experiments were carried out on subsurface soil samples impacted by a low pH, high sulfate, metals (Be, Ni, U, As) plume associated with the long-term operation of a coal plant at the Savannah River Site. These laboratory scale studies provide mechanistic information regarding the solid phases in the soils associated with natural attenuation of the contaminant metals. This data provides input to be evaluated in the definition of the contaminant source term as well as transport of contaminants for site transport models.

  14. Relationship between acoustic measures and speech naturalness ratings in Parkinson's disease: A within-speaker approach.

    PubMed

    Klopfenstein, Marie

    2015-01-01

    This study investigated the acoustic basis of across-utterance, within-speaker variation in speech naturalness for four speakers with dysarthria secondary to Parkinson's disease (PD). Speakers read sentences and produced spontaneous speech. Acoustic measures of fundamental frequency, phrase-final syllable lengthening, intensity and speech rate were obtained. A group of listeners judged speech naturalness using a nine-point Likert scale. Relationships between judgements of speech naturalness and acoustic measures were determined for individual speakers with PD. Relationships among acoustic measures also were quantified. Despite variability between speakers, measures of mean F0, intensity range, articulation rate, average syllable duration, duration of final syllables, vocalic nucleus length of final unstressed syllables and pitch accent of final syllables emerged as possible acoustic variables contributing to within-speaker variations in speech naturalness. Results suggest that acoustic measures correlate with speech naturalness, but in dysarthric speech they depend on the speaker due to the within-speaker variation in speech impairment.

  15. Unified fractional differential approach for transient interporosity flow in naturally fractured media

    NASA Astrophysics Data System (ADS)

    Babak, Petro; Azaiez, Jalel

    2014-12-01

    A unified approach to modeling flows of slightly compressible fluids through naturally fractured media is presented. The unified fractional differential model is derived by combining the flow at micro scale for matrix blocks and macro scale for fractures, using the transient interporosity flow behavior at the interface between matrix blocks and fractures. The derived model is able to unify existing transient interporosity flow models formulated for different shapes of matrix blocks in any medium dimensions. The model is formulated in the form of a fractional order partial differential equation that involves Caputo derivative of order 1/2 with respect to time. Explicit solutions for the unified model are derived for different axisymmetrical spatial domains using Hankel or Hankel-Weber finite or infinite transforms. Comparisons between the predictions of the unified model and those obtained from existing transient interporosity flow models for matrix blocks in the form of slabs, spheres and cylinders are presented. It is shown that the unified fractional derivative model leads to solutions that are very close to those of transient interporosity flow models for fracture-dominant and transitional fracture-to-matrix dominant flow regimes. An analysis of the results of the unified model reveals that the pressure varies linearly with the logarithm of time for different flow regimes, with half slope for the transitional fracture-to-matrix dominant flow regime vs. the fracture and matrix dominant flow regimes. In addition, a new re-scaling that involves the characteristic length in the form of matrix block volume to surface area ratio is derived for the transient interporosity flow models for matrix blocks of different shapes. It is shown that the re-scaled transient interporosity flow models are governed by two dimensionless parameters Θ and Λ compared to only one dimensionless parameter Θ for the unified model. It is shown that the solutions of the transient

  16. An observation-based approach to identify local natural dust events from routine aerosol ground monitoring

    NASA Astrophysics Data System (ADS)

    Tong, D. Q.; Dan, M.; Wang, T.; Lee, P.

    2012-02-01

    Dust is a major component of atmospheric aerosols in many parts of the world. Although there exist many routine aerosol monitoring networks, it is often difficult to obtain dust records from these networks, because these monitors are either deployed far away from dust active regions (most likely collocated with dense population) or contaminated by anthropogenic sources and other natural sources, such as wildfires and vegetation detritus. Here we propose a new approach to identify local dust events relying solely on aerosol mass and composition from general-purpose aerosol measurements. Through analyzing the chemical and physical characteristics of aerosol observations during satellite-detected dust episodes, we select five indicators to be used to identify local dust records: (1) high PM10 concentrations; (2) low PM2.5/PM10 ratio; (3) higher concentrations and percentage of crustal elements; (4) lower percentage of anthropogenic pollutants; and (5) low enrichment factors of anthropogenic elements. After establishing these identification criteria, we conduct hierarchical cluster analysis for all validated aerosol measurement data over 68 IMPROVE sites in the Western United States. A total of 182 local dust events were identified over 30 of the 68 locations from 2000 to 2007. These locations are either close to the four US Deserts, namely the Great Basin Desert, the Mojave Desert, the Sonoran Desert, and the Chihuahuan Desert, or in the high wind power region (Colorado). During the eight-year study period, the total number of dust events displays an interesting four-year activity cycle (one in 2000-2003 and the other in 2004-2007). The years of 2003, 2002 and 2007 are the three most active dust periods, with 46, 31 and 24 recorded dust events, respectively, while the years of 2000, 2004 and 2005 are the calmest periods, all with single digit dust records. Among these deserts, the Chihuahua Desert (59 cases) and the Sonoran Desert (62 cases) are by far the most active

  17. Nonthermal cosmic neutrino background

    NASA Astrophysics Data System (ADS)

    Chen, Mu-Chun; Ratz, Michael; Trautner, Andreas

    2015-12-01

    We point out that, for Dirac neutrinos, in addition to the standard thermal cosmic neutrino background (C ν B ), there could also exist a nonthermal neutrino background with comparable number density. As the right-handed components are essentially decoupled from the thermal bath of standard model particles, relic neutrinos with a nonthermal distribution may exist until today. The relic density of the nonthermal (nt) background can be constrained by the usual observational bounds on the effective number of massless degrees of freedom Neff and can be as large as nν nt≲0.5 nγ. In particular, Neff can be larger than 3.046 in the absence of any exotic states. Nonthermal relic neutrinos constitute an irreducible contribution to the detection of the C ν B and, hence, may be discovered by future experiments such as PTOLEMY. We also present a scenario of chaotic inflation in which a nonthermal background can naturally be generated by inflationary preheating. The nonthermal relic neutrinos, thus, may constitute a novel window into the very early Universe.

  18. Emerging Approach of Natural Language Processing in Opinion Mining: A Review

    NASA Astrophysics Data System (ADS)

    Kim, Tai-Hoon

    Natural language processing (NLP) is a subfield of artificial intelligence and computational linguistics. It studies the problems of automated generation and understanding of natural human languages. This paper outlines a framework to use computer and natural language techniques for various levels of learners to learn foreign languages in Computer-based Learning environment. We propose some ideas for using the computer as a practical tool for learning foreign language where the most of courseware is generated automatically. We then describe how to build Computer Based Learning tools, discuss its effectiveness, and conclude with some possibilities using on-line resources.

  19. An Approach for Monitored Natural Attenuation (MNA) at a LUST Site

    EPA Science Inventory

    The primary mechanism for natural attenuation of fuel components in ground water is aerobic and anaerobic biodegradation of the components. Biodegradation reduces the concentration of oxygen, nitrate and sulfate, and increases the concentrations of iron(II) and methane. Changes...

  20. The Empty-Pot Healing Approach: Its Origins, Nature, and Practice.

    ERIC Educational Resources Information Center

    Oshodi, John Egbeazien

    1999-01-01

    Describes the Oshodi (J. Oshodi) Empty-Pot Healing Approach (OEPHA), an African-based psychotherapeutic approach that aims to create balance and foster achievement motivation. Illustrates the 11 phases of the OEPHA through the case study of an adult psychotherapeutic client. (SLD)

  1. Teaching English as a Second Language: Perspectives and Practices. A Series of Six Texts. Background and Approaches: First of a Series.

    ERIC Educational Resources Information Center

    New York State Education Dept., Albany.

    This book is designed to assist those who work with non-English dominant students by providing resource information relevant to second language teaching and learning. The articles in the series encompass both theory and practical learning techniques in six general topics. The articles in the first text of the series, concerning background and…

  2. A new integrated program for natural product development and the value of an ethnomedical approach.

    PubMed

    Schuster, B G

    2001-01-01

    There is a need for less expensive alternative therapies, especially in the treatment of chronic illnesses. This presentation addresses the issues inherent in the use of natural products in a drug-discovery or development program and reviews a model program developed by the U.S. National Institutes of Health (NIH) and administered by the Fogarty International Center at the NIH. Eighty percent (80%) of the world's population relies on medicinal plants for their primary health care. The World Health Organization has been promoting traditional medicine as a source of less expensive, comprehensive medical care, especially in developing countries. Natural products have also been successful in drug development. Over 50% of the best-selling pharmaceuticals in use today are derived from natural products. In a natural-product drug development program, it is the diversity of the natural products that is especially interesting. Thanks to technologic advances, now is a good time to be looking for new drugs in the natural-product arena. But there are major hurdles to overcome in a natural-products development program, namely, time-to-lead, supply, and ownership. Time-to-lead is complex because most natural products are mixtures or crude extracts. It can be very difficult to isolate the active principles and elucidate their structures. The difficulty of obtaining sufficient supply is often given as a reason for not becoming involved in natural-product drug development or discovery. This presentation details some ways these seeming hurdles can be overcome. The concept of ownership has changed dramatically in recent years. Until recently, genetic resources were considered to belong to no one and to therefore be the heritage of everyone. The United Nations Convention on Biodiversity and the meetings in Rio de Janeiro in 1992, redefined biodiversity ownership. Genetic biodiversity has a potential value and belongs to the country of origin. The International Conservation of

  3. Natural attenuation of metals and radionuclides -- An overview of the Sandia/DOE approach

    SciTech Connect

    Waters, R.D.; Brady, P.V.; Borns, D.J.

    1998-02-01

    Sandia National Laboratories is developing guidelines that outline the technical basis for relying on natural attenuation for the remediation of metals and radionuclide-contaminated soils and groundwaters at US Department of Energy (DOE) sites for those specific cases where natural processes are effective at ameliorating soil and groundwater toxicity. Remediation by monitored natural attenuation (MNA) requires a clear identification of the specific reaction(s) by which contaminant levels are made less available as well as considerable long-term monitoring. Central to MNA is the development of a conceptual model describing the biogeochemical behavior of contaminant(s) in the subsurface. The conceptual model will be used to make testable predictions of contaminant availability over time. In many cases, comparison between this prediction and field measurements will provide the test of whether MNA is to be implemented. As a result, development of the conceptual model should guide site characterization activities as well as long-term monitoring.

  4. Internet-Based Approaches to Building Stakeholder Networks for Conservation and Natural Resource Management

    EPA Science Inventory

    Social network analysis (SNA) is based on a conceptual network representation of social interactions and is an invaluable tool for conservation professionals to increase collaboration, improve information flow, and increase efficiency. We present two approaches to constructing i...

  5. Internet-Based Approaches to Building Stakeholder Networks for Conservation and Natural Resource Management.

    EPA Science Inventory

    Social network analysis (SNA) is based on a conceptual network representation of social interactions and is an invaluable tool for conservation professionals to increase collaboration, improve information flow, and increase efficiency. We present two approaches to constructing in...

  6. Improving structural similarity based virtual screening using background knowledge

    PubMed Central

    2013-01-01

    Background Virtual screening in the form of similarity rankings is often applied in the early drug discovery process to rank and prioritize compounds from a database. This similarity ranking can be achieved with structural similarity measures. However, their general nature can lead to insufficient performance in some application cases. In this paper, we provide a link between ranking-based virtual screening and fragment-based data mining methods. The inclusion of binding-relevant background knowledge into a structural similarity measure improves the quality of the similarity rankings. This background knowledge in the form of binding relevant substructures can either be derived by hand selection or by automated fragment-based data mining methods. Results In virtual screening experiments we show that our approach clearly improves enrichment factors with both applied variants of our approach: the extension of the structural similarity measure with background knowledge in the form of a hand-selected relevant substructure or the extension of the similarity measure with background knowledge derived with data mining methods. Conclusion Our study shows that adding binding relevant background knowledge can lead to significantly improved similarity rankings in virtual screening and that even basic data mining approaches can lead to competitive results making hand-selection of the background knowledge less crucial. This is especially important in drug discovery and development projects where no receptor structure is available or more frequently no verified binding mode is known and mostly ligand based approaches can be applied to generate hit compounds. PMID:24341870

  7. A view to the future of natural gas and electricity: An integrated modeling approach

    SciTech Connect

    Cole, Wesley J.; Medlock, Kenneth B.; Jani, Aditya

    2016-03-17

    This paper demonstrates the value of integrating two highly spatially resolved models: the Rice World Gas Trade Model (RWGTM) of the natural gas sector and the Regional Energy Deployment System (ReEDS) model of the U.S. electricity sector. The RWGTM passes electricity-sector natural gas prices to the ReEDS model, while the ReEDS model returns electricity-sector natural gas demand to the RWGTM. The two models successfully converge to a solution under reference scenario conditions. We present electricity-sector and natural gas sector evolution using the integrated models for this reference scenario. This paper demonstrates that the integrated models produced similar national-level results as when running in a stand-alone form, but that regional and state-level results can vary considerably. As we highlight, these regional differences have potentially significant implications for electric sector planners especially in the wake of substantive policy changes for the sector (e.g., the Clean Power Plan).

  8. Molecular approaches to the investigation of viable dinoflagellate cysts in natural sediments from estuarine environments.

    PubMed

    Coyne, Kathryn J; Craig Cary, S

    2005-01-01

    Molecular methods offer an efficient alternative to microscopic identification of dinoflagellate cysts in natural sediments. Unfortunately, amplification of DNA also detects the presence of dead cells and is not a reliable indication of cyst viability. Because mRNA transcripts are more labile than DNA, the presence of specific transcripts may be used as a proxy for cyst viability. Here, we evaluate mRNA detection capabilities for identification of viable cysts of the dinoflagellate, Pfiesteria piscicida, in natural sediment samples. We targeted transcripts for cytochrome c oxidase subunit 1, cytochrome b (COB), and Tags 343 and 277, recently identified by serial analysis of gene expression. Expression was confirmed in laboratory cultures and compared with natural sediment samples. Three of the transcripts were detected in sediments by RT-PCR. The fourth transcript, for COB, was not detected in sediments, perhaps because of down-regulation of the gene in anoxic conditions. Our results suggest that methods targeting specific mRNA transcripts may be useful for detection of viable cysts in natural sediment samples. In addition, dinoflagellate cysts, which sustain extended periods of anoxia, may provide an important source of data for studies of anoxia tolerance by microbial eukaryotes.

  9. High School Biology Students' Transfer of the Concept of Natural Selection: A Mixed-Methods Approach

    ERIC Educational Resources Information Center

    Pugh, Kevin J.; Koskey, Kristin L. K.; Linnenbrink-Garcia, Lisa

    2014-01-01

    The concept of natural selection serves as a foundation for understanding diverse biological concepts and has broad applicability to other domains. However, we know little about students' abilities to transfer (i.e. apply to a new context or use generatively) this concept and the relation between students' conceptual understanding and transfer…

  10. A view to the future of natural gas and electricity: An integrated modeling approach

    DOE PAGES

    Cole, Wesley J.; Medlock, Kenneth B.; Jani, Aditya

    2016-03-17

    This paper demonstrates the value of integrating two highly spatially resolved models: the Rice World Gas Trade Model (RWGTM) of the natural gas sector and the Regional Energy Deployment System (ReEDS) model of the U.S. electricity sector. The RWGTM passes electricity-sector natural gas prices to the ReEDS model, while the ReEDS model returns electricity-sector natural gas demand to the RWGTM. The two models successfully converge to a solution under reference scenario conditions. We present electricity-sector and natural gas sector evolution using the integrated models for this reference scenario. This paper demonstrates that the integrated models produced similar national-level results asmore » when running in a stand-alone form, but that regional and state-level results can vary considerably. As we highlight, these regional differences have potentially significant implications for electric sector planners especially in the wake of substantive policy changes for the sector (e.g., the Clean Power Plan).« less

  11. Polymer Selection Approach for Commonly and Uncommonly Used Natural Fibers Under Uncertainty Environments

    NASA Astrophysics Data System (ADS)

    AL-Oqla, Faris M.; Sapuan, S. M.

    2015-07-01

    Factors like awareness of the scarcity of non-renewable natural resources, high petroleum prices, and demands for environmental sustainability, as well as reducing the amount of environmental pollution, have led to a renewed interest in natural fiber reinforced polymer composites as a potential bio-based material type. The best polymer matrix type in view of the wide range of conflicting criteria to form a polymeric-based composite material suitable for sustainable industry under an uncertainty environment has still not been sufficiently determined. This work introduces a selection model to evaluate the available polymers for natural fibers to enhance the industrial sustainability theme. The model built was developed to evaluate various polymer types and to determine their relative merits taking account of various conflicting criteria for both commonly used and uncommonly used natural fibers utilizing the analytical hierarchy process technique. It was found that the choice of the best polymer type for a certain fiber type depends strongly on the polymers' intrinsic desirable conflicting characteristics. Polymers evaluations are illustrated for different technical criteria in order to facilitate the polymer selection process for various industrial applications with high confidence levels.

  12. An Approach for Evaluating the Progress of Natural Attenuation in Groundwater (Web Conference)

    EPA Science Inventory

    Monitored Natural Attenuation (MNA) is widely applied to ground water contamination at hazardous waste sites. Under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), MNA is considered to be a remedy like any other remedy. When MNA has been select...

  13. Teaching Science Rhetorically: An Interdisciplinary Approach to Natural History, 1948-1985.

    ERIC Educational Resources Information Center

    DePaolo, Charles

    1987-01-01

    Considers the different analogies used by James Rettie, Teilhard de Chardin, Robert Ardrey, Jacob Bronowski, Richard Leakey, Steven Weinberg, Heinz Pagels, and Carl Sagan to make concepts related to time and natural history accessible to the layperson. Suggests that these analogies be used at the undergraduate level in both humanities and science…

  14. Beyond Exemplars and Prototypes as Memory Representations of Natural Concepts: A Clustering Approach

    ERIC Educational Resources Information Center

    Verbeemen, Timothy; Vanpaemel, Wolf; Pattyn, Sven; Storms, Gert; Verguts, Tom

    2007-01-01

    Categorization in well-known natural concepts is studied using a special version of the Varying Abstraction Framework (Vanpaemel, W., & Storms, G. (2006). A varying abstraction framework for categorization. Manuscript submitted for publication; Vanpaemel, W., Storms, G., & Ons, B. (2005). A varying abstraction model for categorization. In B. Bara,…

  15. Undergraduate Students' Conceptions of Natural and Anthropogenic Climate Change: A Case Study Approach

    ERIC Educational Resources Information Center

    Trenbath, Thien-Kim Leckie

    2012-01-01

    This dissertation shows the evolution of five undergraduate students' ideas of natural and anthropogenic climate change throughout a lecture hall course on climate change. This research was informed by conceptual change theory and students' inaccurate ideas of climate change. Subjects represented different levels of climate change understanding at…

  16. High-pressure Diels-Alder approach to natural kainic acid.

    PubMed

    Pandey, Sushil K; Orellana, Arturo; Greene, Andrew E; Poisson, Jean-François

    2006-11-23

    The first Diels-Alder based synthesis of (-)-kainic acid is described. Danishefsky's diene and a vinylogous malonate derived from 4-hydroxyproline combine under high pressure to afford a key bicyclic intermediate with virtually no loss of enantiopurity. This adduct can be converted into the natural product with complete stereocontrol. [reaction: see text].

  17. The Natural Approach to Adult Learning and Teaching of L2 Grammar

    ERIC Educational Resources Information Center

    Scheffler, Pawel

    2008-01-01

    Learning a language in a natural way is normally understood to involve the development of implicit knowledge of that language. The acquisition of such knowledge takes place through communication and is driven by learner-internal mechanisms which cannot be directly influenced by formal instruction. In the case of foreign or second language (L2)…

  18. Long-term assessment of natural attenuation: statistical approach on soils with aged PAH contamination.

    PubMed

    Ouvrard, Stéphanie; Chenot, Elodie-Denise; Masfaraud, Jean-François; Schwartz, Christophe

    2013-07-01

    Natural attenuation processes valorization for PAH-contaminated soil remediation has gained increasing interest from site owners. A misunderstanding of this method and a small amount of data available does not encourage its development. However, monitored natural attenuation (MNA) offers a valuable, cheaper and environmentally friendly alternative to more classical options such as physico-chemical treatments (e.g., chemical oxidation, thermal desorption). The present work proposes the results obtained during a long-term natural attenuation assessment of historically contaminated industrial soils under real climatic conditions. This study was performed after a 10 year natural attenuation period on 60 off-ground lysimeters filled with contaminated soils from different former industrial sites (coking industry, manufactured gas plants) whose initial concentration of PAH varied between 380 and 2,077 mg kg(-1). The analysed parameters included leached water characterization, soil PAH concentrations, evaluation of vegetation cover quality and quantity. Results showed a good efficiency of the PAH dissipation and limited transfer of contaminants to the environment. It also highlighted the importance of the fine soil fractions in controlling PAH reactivity. PAH dissipation through water leaching was limited and did not present a significant risk for the environment. This PAH water concentration appeared however as a good indicator of overall dissipation rate, thereby illustrating the importance of pollutant availability in predicting its degradation potential.

  19. Longitudinal, Educational Design Research Investigation of the Temporal Nature of Learning: Taking a Vygotskian Approach

    ERIC Educational Resources Information Center

    Cook, John

    2010-01-01

    The nature of learning is being augmented by new digital tools, particularly by mobile devices and the networks and structures to which they connect people. In this paper I examine some longitudinal research "threads" that have pervaded my work over the last two decades: (i) the powerful perspectives on learning and development put…

  20. A library screening approach identifies naturally occurring RNA sequences for a G-quadruplex binding ligand.

    PubMed

    Mirihana Arachchilage, Gayan; Morris, Mark J; Basu, Soumitra

    2014-02-07

    An RNA G-quadruplex library was synthesised and screened against kanamycin A as the ligand. Naturally occurring G-quadruplex forming sequences that differentially bind to kanamycin A were identified and characterized. This provides a simple and effective strategy for identification of potential intracellular G-quadruplex targets for a ligand.

  1. Undergraduate students' conceptions of natural and anthropogenic climate change: A case study approach

    NASA Astrophysics Data System (ADS)

    Trenbath, Thien-Kim Leckie

    This dissertation shows the evolution of five undergraduate students' ideas of natural and anthropogenic climate change throughout a lecture hall course on climate change. This research was informed by conceptual change theory and students' inaccurate ideas of climate change. Subjects represented different levels of climate change understanding at the beginning of the course and were selected based on their scores on a climate change questionnaire. The study was designed to research how students' ideas changed throughout the course and compare trajectories of lower and higher achieving students. At the beginning, students had different levels of understanding, but as the semester continued, the lower-performing students progressed more than the higher-performing students. At the end of the course, all students described more ideas than they did at the beginning; however some of these ideas were inconsistent with the professors' instruction. Lower-performing students struggled more than the higher-performing students. Struggles included differentiating climate change and its causes, effects, and consequences from other environmental problems. Students also struggled with the idea that climate change is anthropogenic despite it being natural in the past. In order to understand that climate change is impacted by human forcings in addition to natural forcings, students developed the relationship that climate change is natural and humans are "speeding it up." They took time to integrate this relationship into their prior ideas. Three of the students constructed a definition of climate change that was different than the professor's. Two students defined "climate change" as only the natural aspects of climate change and reserved the anthropogenic changes for the term "global warming". For a third student, "climate change" included damming rivers, eutrophication, frog mutations, ozone depletion, and overfishing, which are environmental ailments but not climate change.

  2. Integrated approaches to natural resources management in practice: the catalyzing role of National Adaptation Programmes for Action.

    PubMed

    Stucki, Virpi; Smith, Mark

    2011-06-01

    The relationship of forests in water quantity and quality has been debated during the past years. At the same time, focus on climate change has increased interest in ecosystem restoration as a means for adaptation. Climate change might become one of the key drivers pushing integrated approaches for natural resources management into practice. The National Adaptation Programme of Action (NAPA) is an initiative agreed under the UN Framework Convention on Climate Change. An analysis was done to find out how widely ecosystem restoration and integrated approaches have been incorporated into NAPA priority adaptation projects. The data show that that the NAPAs can be seen as potentially important channel for operationalizing various integrated concepts. Key challenge is to implement the NAPA projects. The amount needed to implement the NAPA projects aiming at ecosystem restoration using integrated approaches presents only 0.7% of the money pledged in Copenhagen for climate change adaptation.

  3. Multivariate approach to quantitative analysis of Aphis gossypii Glover (Hemiptera: Aphididae) and their natural enemy populations at different cotton spacings

    NASA Astrophysics Data System (ADS)

    Malaquias, José B.; Ramalho, Francisco S.; Dos S. Dias, Carlos T.; Brugger, Bruno P.; S. Lira, Aline Cristina; Wilcken, Carlos F.; Pachú, Jéssica K. S.; Zanuncio, José C.

    2017-02-01

    The relationship between pests and natural enemies using multivariate analysis on cotton in different spacing has not been documented yet. Using multivariate approaches is possible to optimize strategies to control Aphis gossypii at different crop spacings because the possibility of a better use of the aphid sampling strategies as well as the conservation and release of its natural enemies. The aims of the study were (i) to characterize the temporal abundance data of aphids and its natural enemies using principal components, (ii) to analyze the degree of correlation between the insects and between groups of variables (pests and natural enemies), (iii) to identify the main natural enemies responsible for regulating A. gossypii populations, and (iv) to investigate the similarities in arthropod occurrence patterns at different spacings of cotton crops over two seasons. High correlations in the occurrence of Scymnus rubicundus with aphids are shown through principal component analysis and through the important role the species plays in canonical correlation analysis. Clustering the presence of apterous aphids matches the pattern verified for Chrysoperla externa at the three different spacings between rows. Our results indicate that S. rubicundus is the main candidate to regulate the aphid populations in all spacings studied.

  4. Multivariate approach to quantitative analysis of Aphis gossypii Glover (Hemiptera: Aphididae) and their natural enemy populations at different cotton spacings.

    PubMed

    Malaquias, José B; Ramalho, Francisco S; Dos S Dias, Carlos T; Brugger, Bruno P; S Lira, Aline Cristina; Wilcken, Carlos F; Pachú, Jéssica K S; Zanuncio, José C

    2017-02-09

    The relationship between pests and natural enemies using multivariate analysis on cotton in different spacing has not been documented yet. Using multivariate approaches is possible to optimize strategies to control Aphis gossypii at different crop spacings because the possibility of a better use of the aphid sampling strategies as well as the conservation and release of its natural enemies. The aims of the study were (i) to characterize the temporal abundance data of aphids and its natural enemies using principal components, (ii) to analyze the degree of correlation between the insects and between groups of variables (pests and natural enemies), (iii) to identify the main natural enemies responsible for regulating A. gossypii populations, and (iv) to investigate the similarities in arthropod occurrence patterns at different spacings of cotton crops over two seasons. High correlations in the occurrence of Scymnus rubicundus with aphids are shown through principal component analysis and through the important role the species plays in canonical correlation analysis. Clustering the presence of apterous aphids matches the pattern verified for Chrysoperla externa at the three different spacings between rows. Our results indicate that S. rubicundus is the main candidate to regulate the aphid populations in all spacings studied.

  5. Multivariate approach to quantitative analysis of Aphis gossypii Glover (Hemiptera: Aphididae) and their natural enemy populations at different cotton spacings

    PubMed Central

    Malaquias, José B.; Ramalho, Francisco S.; dos S. Dias, Carlos T.; Brugger, Bruno P.; S. Lira, Aline Cristina; Wilcken, Carlos F.; Pachú, Jéssica K. S.; Zanuncio, José C.

    2017-01-01

    The relationship between pests and natural enemies using multivariate analysis on cotton in different spacing has not been documented yet. Using multivariate approaches is possible to optimize strategies to control Aphis gossypii at different crop spacings because the possibility of a better use of the aphid sampling strategies as well as the conservation and release of its natural enemies. The aims of the study were (i) to characterize the temporal abundance data of aphids and its natural enemies using principal components, (ii) to analyze the degree of correlation between the insects and between groups of variables (pests and natural enemies), (iii) to identify the main natural enemies responsible for regulating A. gossypii populations, and (iv) to investigate the similarities in arthropod occurrence patterns at different spacings of cotton crops over two seasons. High correlations in the occurrence of Scymnus rubicundus with aphids are shown through principal component analysis and through the important role the species plays in canonical correlation analysis. Clustering the presence of apterous aphids matches the pattern verified for Chrysoperla externa at the three different spacings between rows. Our results indicate that S. rubicundus is the main candidate to regulate the aphid populations in all spacings studied. PMID:28181503

  6. Natural polyphenols down-regulate universal stress protein in Mycobacterium tuberculosis: An in-silico approach

    PubMed Central

    Aanandhi, M. Vijey; Bhattacherjee, Debojit; George, P. Samuel Gideon; Ray, Anirban

    2014-01-01

    Universal stress protein (USP) is a novel target to overcome the tuberculosis resistance. Our present study enlightens the possibilities of some natural polyphenols as an antioxidant for USP. The study has shown some molecular simulations of some selected natural antioxidants with USP. We have considered USP (Rv1636) strain for homology modeling and the selected template was taken for the docking study. Curcumin, catechin, reservetrol has shown ARG 136 (1.8Å) hydrogen bonding and two ionic bonding with carboxyl group of curcumin with LEU 130 (3.3Å) and ASN 144 (3.4Å) respectively. INH was taken for the standard molecule to perform molecular simulation. It showed poor binding interaction with the target, that is, −5.18 kcal, and two hydrogen bonding with SER 140 (1.887Å), ARG 147 (2.064Å) respectively. The study indicates possible new generation curcumin analogue for future therapy to down-regulate USP. PMID:25364695

  7. Simple green approach to reinforce natural rubber with bacterial cellulose nanofibers.

    PubMed

    Trovatti, Eliane; Carvalho, Antonio J F; Ribeiro, Sidney J L; Gandini, Alessandro

    2013-08-12

    Natural rubber (NR) is a renewable polymer with a wide range of applications, which is constantly tailored, further increasing its utilizations. The tensile strength is one of its most important properties susceptible of being enhanced by the simple incorporation of nanofibers. The preparation and characterization of natural-rubber based nanocomposites reinforced with bacterial cellulose (BC) and bacterial cellulose coated with polystyrene (BCPS), yielded high performance materials. The nanocomposites were prepared by a simple and green process, and characterized by tensile tests, dynamical mechanical analysis (DMA), scanning electron microscopy (SEM), and swelling experiments. The effect of the nanofiber content on morphology, static, and dynamic mechanical properties was also investigated. The results showed an increase in the mechanical properties, such as Young's modulus and tensile strength, even with modest nanofiber loadings.

  8. Nonlocal Nature of the Viscous Transport in Supercooled Liquids: Complex Fluid Approach to Supercooled Liquids

    SciTech Connect

    Furukawa, Akira; Tanaka, Hajime

    2009-09-25

    Using molecular dynamics simulations, we show clear evidence for the nonlocal mesoscopic nature of the anomalous viscous transport in a supercooled liquid and its direct link to dynamic heterogeneity: (i) a distinct crossover from the microscopic to macroscopic viscosity at a mesoscopic length scale, which is comparable to the correlation length of dynamic heterogeneity and grows with an increase in the degree of supercooling; (ii) a strong anisotropic decay of the shear-stress autocorrelation at a finite wave number, which indicates intrinsic decoupling between the longitudinal and transverse dynamics. Our findings suggest the fundamental importance of the growing dynamic correlation in anomalous transport and shed new light on the nature of slow dynamics.

  9. Enantioselective Syntheses of Heteroyohimbine Natural Products: A Unified Approach through Cooperative Catalysis.

    PubMed

    Younai, Ashkaan; Zeng, Bi-Shun; Meltzer, Herbert Y; Scheidt, Karl A

    2015-06-01

    Alstonine and serpentine are pentacyclic indoloquinolizidine alkaloids (referred to as "anhydronium bases") containing three contiguous stereocenters. Each possesses interesting biological activity, with alstonine being the major component of a plant-based remedy to treat psychosis and other nervous system disorders. This work describes the enantioselective total syntheses of these natural products with a cooperative hydrogen bonding/enamine-catalyzed Michael addition as the key step.

  10. Technical approaches of a natural dye extracted from Phytolacca americana L.-berries with chemical mordants.

    PubMed

    Park, Su-Youn; Jung, Suk-Yul

    2014-01-01

    Phytolacca americana L. is a large semi-succulent herbaceous plant which reaches three meters in height. It is native to eastern North America, the Midwest, and the Gulf Coast, with more scattered populations in the far West. It is imported into Korea and has been frequently used as a traditional natural drug for diseases such as systemic edema and nephritis. Its berries, that is, fruits are shiny dark purple held in racemous clusters on pink pedicels with a pink peduncle. They are round with a flat indented top and bottom. Immature berries are green, maturing into white and then blackish purple. It is not well known how the berries are used for a natural staining yet. In this study, using Phytolacca americana L.-berries, a natural staining was analyzed. Moreover, due to the broad use of chemical mordants, five different mordants including copper acetate, aluminum potassium sulfate, sodium tartrate plus citric acid, Iron II sulfate and potassium dichromate were combined. Extracted dye from the berries stained silk fabrics with ivory. The original purple color from the berries disappeared and transformed into ivory. Although the silk fabrics were differentially stained by the berries that were combined with mordants of aluminum potassium sulfate, sodium tartrate plus citric acid and potassium dichromate, only differences in lightness and darkness were observed. Interestingly, the combination of the dye from the berries with a mordant of copper acetate and Iron II sulfate induced the staining of the silk fabrics into khaki and dark khaki, respectively. This study is the first systemic report on staining silk fabrics with Phytolacca americana L.-berries and chemical mordants and suggests application of natural products to the fiber industry.

  11. Identification of natural allosteric inhibitor for Akt1 protein through computational approaches and in vitro evaluation.

    PubMed

    Pragna Lakshmi, T; Kumar, Amit; Vijaykumar, Veena; Natarajan, Sakthivel; Krishna, Ramadas

    2017-03-01

    Akt, a serine/threonine protein kinase, is often hyper activated in breast and prostate cancers, but with poor prognosis. Allosteric inhibitors regulate aberrant kinase activity by stabilizing the protein in inactive conformation. Several natural compounds have been reported as inhibitors for kinases. In this study, to identify potential natural allosteric inhibitor for Akt1, we generated a seven-point pharmacophore model and screened it through natural compound library. Quercetin-7-O-β-d-glucopyranoside or Q7G was found to be the best among selected molecules based on its hydrogen bond occupancy with key allosteric residues, persistent polar contacts and salt bridges that stabilize Akt1 in inactive conformation and minimum binding free energy during molecular dynamics simulation. Q7G induced dose-dependent inhibition of breast cancer cells (MDA MB-231) and arrested them in G1 and sub-G phase. This was associated with down-regulation of anti-apoptotic protein Bcl-2, up-regulation of cleaved caspase-3 and PARP. Expression of p-Akt (Ser473) was also down-regulated which might be due to Akt1 inhibition in inactive conformation. We further confirmed the Akt1 and Q7G interaction which was observed to have a dissociation constant (Kd) of 0.246μM. With these computational, biological and thermodynamic studies, we suggest Q7G as a lead molecule and propose for its further optimization.

  12. Generalized approach to inverse problems in tomography: Image reconstruction for spatially variant systems using natural pixels

    SciTech Connect

    Baker, J.R.; Budinger, T.F.; Huesman, R.H.

    1992-10-01

    A major limitation in tomographic inverse problems is inadequate computation speed, which frequently impedes the application of engineering ideas and principles in medical science more than in the physical and engineering sciences. Medical problems are computationally taxing because a minimum description of the system often involves 5 dimensions (3 space, 1 energy, 1 time), with the range of each space coordinate requiring up to 512 samples. The computational tasks for this problem can be simply expressed by posing the problem as one in which the tomograph system response function is spatially invariant, and the noise is additive and Gaussian. Under these assumptions, a number of reconstruction methods have been implemented with generally satisfactory results for general medical imaging purposes. However, if the system response function of the tomograph is assumed more realistically to be spatially variant and the noise to be Poisson, the computational problem becomes much more difficult. Some of the algorithms being studied to compensate for position dependent resolution and statistical fluctuations in the data acquisition process, when expressed in canonical form, are not practical for clinical applications because the number of computations necessary exceeds the capabilities of high performance computer systems currently available. Reconstruction methods based on natural pixels, specifically orthonormal natural pixels, preserve symmetries in the data acquisition process. Fast implementations of orthonormal natural pixel algorithms can achieve orders of magnitude speedup relative to general implementations. Thus, specialized thought in algorithm development can lead to more significant increases in performance than can be achieved through hardware improvements alone.

  13. An Approach to Teaching General Chemistry II that Highlights the Interdisciplinary Nature of Science

    ERIC Educational Resources Information Center

    Sumter, Takita Felder; Owens, Patrick M.

    2011-01-01

    The need for a revised curriculum within the life sciences has been well-established. One strategy to improve student preparation in the life sciences is to redesign introductory courses like biology, chemistry, and physics so that they better reflect their disciplinary interdependence. We describe a medically relevant, context-based approach to…

  14. A macrocyclic approach to tetracycline natural products. Investigation of transannular alkylations and Michael additions.

    PubMed

    Wzorek, Joseph S; Knöpfel, Thomas F; Sapountzis, Ioannis; Evans, David A

    2012-12-07

    A new approach to the tetracycline core structure is presented. The pivotal intermediate is identified as macrocycle III. The two interior bonds (C4a-C12a and C5a-C11a) are to be constructed through sequential transannular Michael additions (III-II) and compression-promoted transannular isoxazole alkylations from intermediate II.

  15. A new approach to evaluate natural zeolite ability to sorb lead (Pb) from aqueous solutions

    NASA Astrophysics Data System (ADS)

    Drosos, Evangelos I. P.; Karapanagioti, Hrissi K.

    2013-04-01

    Lead (Pb) is a hazardous pollutant commonly found in aquatic ecosystems. Among several methods available, the addition of sorbent amendments to soils or sediments is attractive, since its application is relatively simple, while it can also be cost effective when a low cost and re-usable sorbent is used; e.g. natural zeolites. Zeolites are crystalline aluminosilicates with a three-dimensional structure composed of a set of cavities occupied by large ions and water molecules. Zeolites can accommodate a wide variety of cations, such as Na+, K+, Ca2+, Mg2+, which are rather loosely held and can readily be exchanged for others in an aqueous solution. Natural zeolites are capable of removing cations, such as lead, from aqueous solutions by ion exchange. There is a wide variation in the cation exchange capacity (CEC) of natural zeolites because of the different nature of various zeolites cage structures, natural structural defects, adsorbed ions, and their associated gangue minerals. Naturally occurring zeolites are rarely pure and are contaminated to varying degrees by other minerals, such as clays and feldspars, metals, quartz, or other zeolites as well. These impurities affect the CEC even for samples originated from the same region but from a different source. CEC of the material increases with decreasing impurity content. Potentially exchangeable ions in such impurities do not necessarily participate in ion exchange mechanism, while, in some cases, impurities may additionally block the access to active sites. For zeoliferous rocks having the same percentage of a zeolitic phase, the CEC increases with decreasing Si/Al ratio, as the more Si ions are substituted by Al ions, the more negative the valence of the matrix becomes. Sodium seems to be the most effective exchangeable ion for lead. On the contrary, it is unlikely that the potassium content of the zeolite would be substituted. A pretreatment with high concentration solutions of Na, such as 2 M NaCl, can

  16. Distribution of uranium, thorium and some stable trace and toxic elements in human hair and nails in Niška Banja Town, a high natural background radiation area of Serbia (Balkan Region, South-East Europe).

    PubMed

    Sahoo, S K; Žunić, Z S; Kritsananuwat, R; Zagrodzki, P; Bossew, P; Veselinovic, N; Mishra, S; Yonehara, H; Tokonami, S

    2015-07-01

    Human hair and nails can be considered as bio-indicators of the public exposure to certain natural radionuclides and other toxic metals over a long period of months or even years. The level of elements in hair and nails usually reflect their levels in other tissues of body. Niška Banja, a spa town located in southern Serbia, with locally high natural background radiation was selected for the study. To assess public exposure to the trace elements, hair and nail samples were collected and analyzed. The concentrations of uranium, thorium and some trace and toxic elements (Mn, Ni, Cu, Sr, Cd, and Cs) were determined using inductively coupled plasma mass spectrometry (ICP-MS). U and Th concentrations in hair varied from 0.0002 to 0.0771 μg/g and from 0.0002 to 0.0276 μg/g, respectively. The concentrations in nails varied from 0.0025 to 0.0447 μg/g and from 0.0023 to 0.0564 μg/g for U and Th, respectively. We found significant correlations between some elements in hair and nails. Also indications of spatial clustering of high values could be found. However, this phenomenon as well as the large variations in concentrations of heavy metals in hair and nail could not be explained. As hypotheses, we propose possible exposure pathways which may explain the findings, but the current data does not allow testing them.

  17. A Novel Approach to Constrain the Escape Fraction and Dust Content at High Redshift Using the Cosmic Infrared Background Fractional Anisotropy

    NASA Astrophysics Data System (ADS)

    Fernandez, Elizabeth R.; Dole, Herve; Iliev, Ilian T.

    2013-02-01

    The Cosmic Infrared Background (CIB) provides an opportunity to constrain many properties of the high-redshift (z > 6) stellar population as a whole. This background, specifically from 1 to 200 μm, should contain information about the era of reionization and the stars that are responsible for these ionizing photons. In this paper, we look at the fractional anisotropy (δI/I) of this high-redshift population, where δI is the ratio of the magnitude of the fluctuations and I is the mean intensity. We show that this can be used to constrain the escape fraction of the population as a whole, because the magnitude of the fluctuations of the CIB depends on the escape fraction, while the mean intensity does not. This results in lower values of the escape fraction producing higher values of the fractional anisotropy. This difference is predicted to be larger at longer wavelength bands (above 10 μm), albeit it is also much harder to observe in that range. We show that the fractional anisotropy can also be used to separate a dusty from a dust-free population. Finally, we discuss the constraints provided by current observations on the CIB fractional anisotropy.

  18. Assessment of three approaches of bioremediation (Natural Attenuation, Landfarming and Bioagumentation - Assistited Landfarming) for a petroleum hydrocarbons contaminated soil.

    PubMed

    Guarino, C; Spada, V; Sciarrillo, R

    2017-03-01

    Contamination with total petroleum hydrocarbons (TPH) subsequent to refining activities, is currently one of the major environmental problems. Among the biological remediation approaches, landfarming and in situ bioremediation strategies are of great interest. Purpose of this study was to verify the feasibility of a remediation process wholly based on biological degradation applied to contaminated soils from a decommissioned refinery. This study evaluated through a pot experiment three bioremediation strategies: a) Natural Attenuation (NA), b) Landfarming (L), c) Bioaugmentation-assisted Landfarming (LB) for the treatment of a contaminated soil with petroleum hydrocarbons (TPHs). After a 90-days trial, Bioagumentation - assistited Landfarming approach produced the best results and the greatest evident effect was shown with the most polluted samples reaching a reduction of about 86% of total petroleum hydrocarbons (TPH), followed by Landfarming (70%), and Natural Attenuation (57%). The results of this study demonstrated that the combined use of bioremediation strategies was the most advantageous option for the treatment of contaminated soil with petroleum hydrocarbons, as compared to natural attenuation, bioaugmentation or landfarming applied alone. Besides, our results indicate that incubation with an autochthonous bacterial consortium may be a promising method for bioremediation of TPH-contaminated soils.

  19. Health, biodiversity, and natural resource use on the Amazon frontier: an ecosystem approach.

    PubMed

    Murray, T P; Sánchez-Choy, J

    2001-01-01

    This study aims to improve the health of rural Amazonian communities through the development and application of a participatory ecosystem approach to human health assessment. In the study area marked seasonal fluctuations dictate food availability, water quality and disease outbreak. Determining the causal linkages between ecosystem variables, resource use and health required a variety of forms of inquiry at multiple scales with local participation. Landscape spatial mapping of resource use demonstrated the diversity of the ecological resources upon which communities depend. Household surveys detailed family and individual consumption and production patterns. Anthropometric measurements, parasite loading, water quality and anemia levels were used as indicators of health status. This was complemented with an ethnographic and participatory health assessment that provided the foundation for developing community action plans addressing health issues. Discussion is focused on three attributes of an ecosystem approach; (a) methodological pluralism, (b) cross-scale interactions and (c) participatory action research.

  20. Fluorescent diagnostics of organic pollution in natural waters: A neural network approach

    SciTech Connect

    Orlov, Y.V.; Persiantsev, I.G.; Rebrik, S.P.

    1995-12-31

    Rapid diagnosis of pollution is one of the key tasks in the field of ecological monitoring of natural and technogeneous environment. One of the promising methods of fluorescent diagnosis of organic pollution of water environment is the registration and analysis of two-dimensional Spectral Fluorescent Signatures (SFS). The neural networks - based system suggested in this paper is intended for solving the problem of detection, identification, and concentration measurement of water environmental pollution. The suggested system uses SFS as input pattern and allows one to build a rapid diagnosis system for ecological monitoring.

  1. The cause of complexity in nature: An analytical and computational approach

    NASA Astrophysics Data System (ADS)

    Mainzer, Klaus

    2012-09-01

    This work is going to present the cause of complexity in nature from an analytical and computational point of view. The cause of complex pattern formation is explained by the local activity of cells in complex systems which are analytically modeled by nonlinear reaction-diffusion equations in physics, chemistry, biology and brain research. There are not only rigorous analytical criteria of local activity and the edge of chaos, but also constructive procedures to visualize them by computer simulations. In technology, the question arises whether these criteria and procedures can be used to construct artificial life and artificial minds.

  2. ENHANCED ATTENUATION: A REFERENCE GUIDE ON APPROACHES TO INCREASE THE NATURAL TREATMENT CAPACITY OF A SYSTEM

    SciTech Connect

    Looney, B; Michael Heitkamp, M; Gary Wein , G; Karen Vangelas, K; Karen-M Adams, K; Tom Early; Bob Borden; David Major; W. Jody Waugh; Todd Wiedemeier; Claire H. Sink

    2006-08-10

    The objective of this document is to explore the realm of enhancements to natural attenuation processes for cVOCs and review examples that have been proposed, modeled, and implemented. We will identify lessons learned from these case studies to confirm that enhancements are technically feasible and have the potential to achieve a favorable, cost-effective contaminant mass balance. Furthermore, we hope to determine if opportunities for further improvement of the enhancements exist and suggest areas where new and innovative types of enhancements might be possible.

  3. Enhanced Attenuation: A Reference Guide On Approaches To Increase The Natural Treatment Capacity Of A System

    SciTech Connect

    Vangelas, K

    2006-01-30

    The objective of this document is to explore the realm of enhancements to natural attenuation processes for cVOCs and review examples that have been proposed, modeled, and implemented. We will identify lessons learned from these case studies to confirm that enhancements are technically feasible and have the potential to achieve a favorable, cost-effective contaminant mass balance. Furthermore, we hope to determine if opportunities for further improvement of the enhancements exist and suggest areas where new and innovative types of enhancements might be possible.

  4. An objective and parsimonious approach for classifying natural flow regimes at a continental scale

    USGS Publications Warehouse

    Archfield, Stacey A.; Kennen, Jonathan G.; Carlisle, Daren M.; Wolock, David M.

    2014-01-01

    Hydro-ecological stream classification-the process of grouping streams by similar hydrologic responses and, by extension, similar aquatic habitat-has been widely accepted and is considered by some to be one of the first steps towards developing ecological flow targets. A new classification of 1543 streamgauges in the contiguous USA is presented by use of a novel and parsimonious approach to understand similarity in ecological streamflow response. This novel classification approach uses seven fundamental daily streamflow statistics (FDSS) rather than winnowing down an uncorrelated subset from 200 or more ecologically relevant streamflow statistics (ERSS) commonly used in hydro-ecological classification studies. The results of this investigation demonstrate that the distributions of 33 tested ERSS are consistently different among the classification groups derived from the seven FDSS. It is further shown that classification based solely on the 33 ERSS generally does a poorer job in grouping similar streamgauges than the classification based on the seven FDSS. This new classification approach has the additional advantages of overcoming some of the subjectivity associated with the selection of the classification variables and provides a set of robust continental-scale classes of US streamgauges. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

  5. Internet-Based Approaches to Building Stakeholder Networks for Conservation and Natural Resource Management.

    PubMed

    Kreakie, B J; Hychka, K C; Belaire, J A; Minor, E; Walker, H A

    2016-02-01

    Social network analysis (SNA) is based on a conceptual network representation of social interactions and is an invaluable tool for conservation professionals to increase collaboration, improve information flow, and increase efficiency. We present two approaches to constructing internet-based social networks, and use an existing traditional (survey-based) case study to illustrate in a familiar context the deviations in methods and results. Internet-based approaches to SNA offer a means to overcome institutional hurdles to conducting survey-based SNA, provide unique insight into an institution's web presences, allow for easy snowballing (iterative process that incorporates new nodes in the network), and afford monitoring of social networks through time. The internet-based approaches differ in link definition: hyperlink is based on links on a website that redirect to a different website and relatedness links are based on a Google's "relatedness" operator that identifies pages "similar" to a URL. All networks were initiated with the same start nodes [members of a conservation alliance for the Calumet region around Chicago (n = 130)], but the resulting networks vary drastically from one another. Interpretation of the resulting networks is highly contingent upon how the links were defined.

  6. Internet-Based Approaches to Building Stakeholder Networks for Conservation and Natural Resource Management

    NASA Astrophysics Data System (ADS)

    Kreakie, B. J.; Hychka, K. C.; Belaire, J. A.; Minor, E.; Walker, H. A.

    2016-02-01

    Social network analysis (SNA) is based on a conceptual network representation of social interactions and is an invaluable tool for conservation professionals to increase collaboration, improve information flow, and increase efficiency. We present two approaches to constructing internet-based social networks, and use an existing traditional (survey-based) case study to illustrate in a familiar context the deviations in methods and results. Internet-based approaches to SNA offer a means to overcome institutional hurdles to conducting survey-based SNA, provide unique insight into an institution's web presences, allow for easy snowballing (iterative process that incorporates new nodes in the network), and afford monitoring of social networks through time. The internet-based approaches differ in link definition: hyperlink is based on links on a website that redirect to a different website and relatedness links are based on a Google's "relatedness" operator that identifies pages "similar" to a URL. All networks were initiated with the same start nodes [members of a conservation alliance for the Calumet region around Chicago ( n = 130)], but the resulting networks vary drastically from one another. Interpretation of the resulting networks is highly contingent upon how the links were defined.

  7. A combined telemetry - tag return approach to estimate fishing and natural mortality rates of an estuarine fish

    USGS Publications Warehouse

    Bacheler, N.M.; Buckel, J.A.; Hightower, J.E.; Paramore, L.M.; Pollock, K.H.

    2009-01-01

    A joint analysis of tag return and telemetry data should improve estimates of mortality rates for exploited fishes; however, the combined approach has thus far only been tested in terrestrial systems. We tagged subadult red drum (Sciaenops ocellatus) with conventional tags and ultrasonic transmitters over 3 years in coastal North Carolina, USA, to test the efficacy of the combined telemetry - tag return approach. There was a strong seasonal pattern to monthly fishing mortality rate (F) estimates from both conventional and telemetry tags; highest F values occurred in fall months and lowest levels occurred during winter. Although monthly F values were similar in pattern and magnitude between conventional tagging and telemetry, information on F in the combined model came primarily from conventional tags. The estimated natural mortality rate (M) in the combined model was low (estimated annual rate ?? standard error: 0.04 ?? 0.04) and was based primarily upon the telemetry approach. Using high-reward tagging, we estimated different tag reporting rates for state agency and university tagging programs. The combined telemetry - tag return approach can be an effective approach for estimating F and M as long as several key assumptions of the model are met.

  8. A Collaborative Approach for Scoping Ecosystem Services with Stakeholders: The Case of Arrábida Natural Park

    NASA Astrophysics Data System (ADS)

    Lopes, Rita; Videira, Nuno

    2016-08-01

    This paper presents an innovative approach for conducting collaborative scoping processes aiming to elicit multiple values of ecosystem services. The proposed methodology rests on three steps combining different participatory tools that promote a comprehensive examination of the perceptions hold by relevant stakeholder groups. The first step consists of an institutional and stakeholder analysis developed in the study area. The second includes a participatory workshop, where a sequence of scoping exercises is conducted with the active collaboration of the invited stakeholders. The final step aims to validate scoping results and develop dependency networks between organizations and the identified ecosystem services. The approach was tested in the Arrábida Natural Park, a marine and coastal protected area in Portugal. Invited participants were able to identify an extensive list of ecosystem services in the natural area, establish linkages between those services and human wellbeing, identify drivers of change and perform a preliminary screening of the associated ecological, social, and economic values. The case study evaluation provided positive feedback on the usefulness of the approach, which advances the existing set of methods for participatory identification of ecosystem services and sets the scene for involvement of stakeholder groups in assessment and management processes.

  9. Fingerprinting sedimentary and soil units by their natural metal contents: a new approach to assess metal contamination.

    PubMed

    Amorosi, Alessandro; Guermandi, Marina; Marchi, Nazaria; Sammartino, Irene

    2014-12-01

    One of the major issues when assessing soil contamination by inorganic substances is reliable determination of natural metal concentrations. Through integrated sedimentological, pedological and geochemical analyses of 1414 (topsoil/subsoil) samples from 707 sampling stations in the southern Po Plain (Italy), we document that the natural distribution of five potentially toxic metals (Cr, Ni, Cu, Zn and Pb) can be spatially predicted as a function of three major factors: source-rock composition, grain size variability and degree of soil weathering. Thirteen genetic and functional soil units (GFUs), each reflecting a unique combination of these three variables, are fingerprinted by distinctive geochemical signatures. Where sediment is supplied by ultramafic (ophiolite-rich) sources, the natural contents of Cr and Ni in soils almost invariably exceed the Italian threshold limits designated for contaminated lands (150 mg/kg and 120 mg/kg, respectively), with median values around twice the maximum permissible levels (345 mg/kg for Cr and 207 mg/kg for Ni in GFU B5). The original provenance signal is commonly confounded by soil texture, with general tendency toward higher metal concentrations in the finest-grained fractions. Once reliable natural metal concentrations in soils are established, the anthropogenic contribution can be promptly assessed by calculating metal enrichments in topsoil samples. The use of combined sedimentological and pedological criteria to fingerprint GFU geochemical composition is presented here as a new approach to enhance predictability of natural metal contents, with obvious positive feedbacks for legislative purposes and environmental protection. Particularly, natural metal concentrations inferred directly from a new type of pedogeochemical map, built according to the international guideline ISO 19258, are proposed as an efficient alternative to the pre-determined threshold values for soil contamination commonly established by the national

  10. Forecast of natural aquifer discharge using a data-driven, statistical approach.

    PubMed

    Boggs, Kevin G; Van Kirk, Rob; Johnson, Gary S; Fairley, Jerry P

    2014-01-01

    In the Western United States, demand for water is often out of balance with limited water supplies. This has led to extensive water rights conflict and litigation. A tool that can reliably forecast natural aquifer discharge months ahead of peak water demand could help water practitioners and managers by providing advanced knowledge of potential water-right mitigation requirements. The timing and magnitude of natural aquifer discharge from the Eastern Snake Plain Aquifer (ESPA) in southern Idaho is accurately forecast 4 months ahead of the peak water demand, which occurs annually in July. An ARIMA time-series model with exogenous predictors (ARIMAX model) was used to develop the forecast. The ARIMAX model fit to a set of training data was assessed using Akaike's information criterion to select the optimal model that forecasts aquifer discharge, given the previous year's discharge and values of the predictor variables. Model performance was assessed by application of the model to a validation subset of data. The Nash-Sutcliffe efficiency for model predictions made on the validation set was 0.57. The predictor variables used in our forecast represent the major recharge and discharge components of the ESPA water budget, including variables that reflect overall water supply and important aspects of water administration and management. Coefficients of variation on the regression coefficients for streamflow and irrigation diversions were all much less than 0.5, indicating that these variables are strong predictors. The model with the highest AIC weight included streamflow, two irrigation diversion variables, and storage.

  11. Wintering waterbirds and recreationists in natural areas: a sociological approach to the awareness of bird disturbance.

    PubMed

    Le Corre, Nicolas; Peuziat, Ingrid; Brigand, Louis; Gélinaud, Guillaume; Meur-Férec, Catherine

    2013-10-01

    Disturbance to wintering birds by human recreational activities has become a major concern for managers of many natural areas. Few studies have examined how recreationists perceive their effects on birds, although this impacts their behavior on natural areas. We surveyed 312 users on two coastal ornithological sites in Brittany, France, to investigate their perception of the effects of human activities on wintering birds. The results show that the awareness of environmental issues and knowledge of bird disturbance depends on the socioeconomic characteristics of each user group, both between the two sites and within each site. Results also indicate that, whatever the site and the user group, the vast majority of the respondents (77.6%) believed that their own presence had no adverse effects on the local bird population. Various arguments were put forward to justify the users' own harmlessness. Objective information on recreationists' awareness of environmental issues, and particularly on their own impact on birds, is important to guide managers in their choice of the most appropriate visitor educational programs. We recommend developing global but also specific educational information for each type of user to raise awareness of their own impact on birds.

  12. Emerging Approaches in Synchrotron Studies of Materials from Cultural and Natural History Collections.

    PubMed

    Bertrand, Loïc; Bernard, Sylvain; Marone, Federica; Thoury, Mathieu; Reiche, Ina; Gourrier, Aurélien; Sciau, Philippe; Bergmann, Uwe

    2016-02-01

    Synchrotrons have provided significant methods and instruments to study ancient materials from cultural and natural heritages. New ways to visualise (surfacic or volumic) morphologies are developed on the basis of elemental, density and refraction contrasts. They now apply to a wide range of materials, from historic artefacts to paleontological specimens. The tunability of synchrotron beams owing to the high flux and high spectral resolution of photon sources is at the origin of the main chemical speciation capabilities of synchrotron-based techniques. Although, until recently, photon-based speciation was mainly applicable to inorganic materials, novel developments based, for instance, on STXM and deep UV photoluminescence bring new opportunities to study speciation in organic and hybrid materials, such as soaps and organometallics, at a submicrometric spatial resolution over large fields of view. Structural methods are also continuously improved and increasingly applied to hierarchically structured materials for which organisation results either from biological or manufacturing processes. High-definition (spectral) imaging appears as the main driving force of the current trend for new synchrotron techniques for research on cultural and natural heritage materials.

  13. Wintering Waterbirds and Recreationists in Natural Areas: A Sociological Approach to the Awareness of Bird Disturbance

    NASA Astrophysics Data System (ADS)

    Le Corre, Nicolas; Peuziat, Ingrid; Brigand, Louis; Gélinaud, Guillaume; Meur-Férec, Catherine

    2013-10-01

    Disturbance to wintering birds by human recreational activities has become a major concern for managers of many natural areas. Few studies have examined how recreationists perceive their effects on birds, although this impacts their behavior on natural areas. We surveyed 312 users on two coastal ornithological sites in Brittany, France, to investigate their perception of the effects of human activities on wintering birds. The results show that the awareness of environmental issues and knowledge of bird disturbance depends on the socioeconomic characteristics of each user group, both between the two sites and within each site. Results also indicate that, whatever the site and the user group, the vast majority of the respondents (77.6 %) believed that their own presence had no adverse effects on the local bird population. Various arguments were put forward to justify the users' own harmlessness. Objective information on recreationists' awareness of environmental issues, and particularly on their own impact on birds, is important to guide managers in their choice of the most appropriate visitor educational programs. We recommend developing global but also specific educational information for each type of user to raise awareness of their own impact on birds.

  14. Testing Local Adaptation in a Natural Great Tit-Malaria System: An Experimental Approach

    PubMed Central

    Jenkins, Tania; Delhaye, Jessica; Christe, Philippe

    2015-01-01

    Finding out whether Plasmodium spp. are coevolving with their vertebrate hosts is of both theoretical and applied interest and can influence our understanding of the effects and dynamics of malaria infection. In this study, we tested for local adaptation as a signature of coevolution between malaria blood parasites, Plasmodium spp. and its host, the great tit, Parus major. We conducted a reciprocal transplant experiment of birds in the field, where we exposed birds from two populations to Plasmodium parasites. This experimental set-up also provided a unique opportunity to study the natural history of malaria infection in the wild and to assess the effects of primary malaria infection on juvenile birds. We present three main findings: i) there was no support for local adaptation; ii) there was a male-biased infection rate; iii) infection occurred towards the end of the summer and differed between sites. There were also site-specific effects of malaria infection on the hosts. Taken together, we present one of the few experimental studies of parasite-host local adaptation in a natural malaria system, and our results shed light on the effects of avian malaria infection in the wild. PMID:26555892

  15. From Sequential Extraction to Transport Modeling: Monitored Natural Attenuation as a Remediation Approach for Inorganic Contaminants

    SciTech Connect

    Crapse, Kimberly P.; Serkiz, Steven M.; Pishko, Adrian L.; Kaplan, Daniel L.; Lee, Cindy M.; Schank, Anja

    2005-08-18

    To quantify metal natural attenuation processes in terms of environmental availability, sequential extraction experiments were carried out on subsurface soil samples impacted by a low pH, high sulfate, metals (Be, Ni, U, As) plume associated with the long-term operation of a coal plant at the Savannah River Site in South Carolina. Despite significant heterogeneity resulting both from natural and anthropogenic factors, sequential extraction results demonstrate that pH is a controlling factor in the prediction of the distribution of metal contaminants within the solid phases in soils at the site as well as the contaminant partitioning between the soil and the soil solution. Results for beryllium, the most mobile metal evaluated, exhibit increasing attenuation along the plume flow path which corresponds to an increasing plume pH. These laboratory- and field-scale studies provide mechanistic information regarding partitioning of metals to soils at the site (one of the major attenuation mechanisms for the metals at the field site). Subsequently, these data have been used in the definition of the contaminant source terms and contaminant transport factors in risk modeling for the site.

  16. Analysis of liquid natural gas as a truck fuel: a system dynamics approach

    SciTech Connect

    Bray, M.A.; Sebo, D.E.; Mason, T.L.; Mills, J.I.; Rice, R.E.

    1996-10-01

    The purpose of this analysis is to evaluate the potential for growth in use of liquid natural gas (LNG) fueled trucks. . A system dynamics model was constructed for the analysis and a variety of scenarios were investigated. The analysis considers the economics of LNG fuel in the context of the trucking industry to identify barriers to the increased use of LNG trucks and potential interventions or leverage points which may overcome these barriers. The study showed that today, LNG use in trucks is not yet economically viable. A large change in the savings from fuel cost or capital cost is needed for the technology to take off. Fleet owners have no way now to benefit from the environmental benefits of LNG fuel nor do they benefit from the clean burning nature of the fuel. Changes in the fuel cost differential between diesel and LNG are not a research issue. However, quantifying the improvements in reliability and wear from the use of clean fuel could support increased maintenance and warranty periods. Many people involved in the use of LNG for trucks believe that LNG has the potential to occupy a niche within the larger diesel truck business. But if LNG in trucks can become economic, the spread of fuel stations and technology improvements could lead to LNG trucks becoming the dominant technology. An assumption in our simulation work is that LNG trucks will be purchased when economically attractive. None of the simulation results show LNG becoming economic but then only to the level of a niche market.

  17. Discrimination between induced, triggered and natural earthquakes close to hydrocarbon reservoirs: A probabilistic approach based on the modeling of depletion-induced stress changes and seismological source parameters

    NASA Astrophysics Data System (ADS)

    Dahm, T.; Cesca, S.; Hainzl, S.; Krueger, F.

    2011-12-01

    Earthquakes occurring close to hydrocarbon fields under production are often under critical view of being induced or triggered. However, clear and testable rules to discriminate the different events have rarely been developed and tested. The unresolved scientific problem may lead to lengthy public disputes with unpredictable impact on the local acceptance of the exploitation and field operations. We propose a quantitative approach to discriminate induced, triggered and natural earthquakes, which is based on testable input parameters. Maxima of occurrence probability distributions (PdF) are compared for the cases under question, and a single probability of being induced is reported. The uncertainties of earthquake location and seismicity rate is considered in terms of joint probabilities. The PdF of induced events is derived from the modeling of Coulomb stress changes and a rate and state dependent seismicity model. In our case a 3D boundary element method has been modified to estimate the stress changes outside the reservoir, which are related to pore pressure changes in the field formation. The predicted rate of natural earthquakes is either derived from the background seismicity or, in case of rare events, from an estimate of the tectonic loading. Instrumentally derived, seismological information on the event location, source mechanism and the size of the rupture plane is of advantage for the method. If the rupture plane has been estimated, the discrimination between induced or only triggered events is theoretically possible if joint PdF's are integrated over the rupture plane. We apply the approach to two recent events: (1) the Mw 4.3 Ekofisk 2002, North Sea earthquake close to the Ekofisk oil field, and the 2004 Mw 4.4 Rotenburg, Northern Germany earthquake in the vicinity of the Soehlingen gas field. While one event was clearly triggered and induced, the other is possibly only triggered.

  18. Field survey of Canadian background soils: Implications for a new mathematical gas chromatography-flame ionization detection approach for resolving false detections of petroleum hydrocarbons in clean soils.

    PubMed

    Kelly-Hooper, Francine; Farwell, Andrea J; Pike, Glenna; Kennedy, Jocelyn; Wang, Zhendi; Grunsky, Eric C; Dixon, D George

    2014-08-01

    The reference method for the Canada-wide standard (CWS) for petroleum hydrocarbons (PHCs) in soil provides laboratories with methods for generating accurate and reproducible soil analysis results. The CWS PHC tier 1 generic soil-quality guidelines apply to 4 carbon ranges/fractions: F1 (C6-C10), F2 (C10-C16), F3 (C16-C34), and F4 (>C34). The methods and guidelines were developed and validated for soils with approximately 5% total organic carbon (TOC). However, organic soils have much higher TOC levels because of biogenic organic compounds (BOCs) originating from sources such as plant waxes and fatty acids. Coextracted BOCs can have elevated F2-F4 concentrations, which can cause false exceedances of PHC soil guidelines. The present study evaluated false PHC detections in soil samples collected from 34 background sites. The list of analytes included soil type, TOC, polycyclic aromatic hydrocarbons (PAHs), F2, F3, F4, F3a (C16-C22), and F3b (C22-C34). Soils with 3% to 41% TOC falsely exceeded the CWS PHC 300 mg/kg F3 coarse soil guideline. It was previously demonstrated that clean peat had F2:F3b ratios of less than 0.10, while crude oil spiked peat and spiked sand had higher ratios of greater than 0.10. In the present background study, all of the clean organic soils with at least 300 mg/kg F3 had F2:F3b ratios of less than 0.10, which indicated false guideline exceedances. Clean inorganic soils had low F3 concentrations, resulting in high F2:F3b ratios of greater than 0.10. Validation field studies are required to determine if the F2:F3b 0.10 PHC presence versus absence threshold value is applicable to crude oil- and diesel-contaminated sites.

  19. A novel geotechnical/geostatistical approach for exploration and production of natural gas from multiple geologic strata, Phase 1

    SciTech Connect

    Overbey, W.K. Jr.; Reeves, T.K.; Salamy, S.P.; Locke, C.D.; Johnson, H.R.; Brunk, R.; Hawkins, L. )

    1991-05-01

    This research program has been designed to develop and verify a unique geostatistical approach for finding natural gas resources. The project has been conducted by Beckley College, Inc., and BDM Engineering Services Company (BDMESC) under contract to the US Department of Energy (DOE), Morgantown Energy Technology Center (METC). This section, Volume II, contains a detailed discussion of the methodology used and the geological and production information collected and analyzed for this study. A companion document, Volume 1, provides an overview of the program, technique and results of the study. In combination, Volumes I and II cover the completion of the research undertaken under Phase I of this DOE project, which included the identification of five high-potential sites for natural gas production on the Eccles Quadrangle, Raleigh County, West Virginia. Each of these sites was selected for its excellent potential for gas production from both relatively shallow coalbeds and the deeper, conventional reservoir formations.

  20. Traditional and non-traditional approaches to the prediction of natural disasters

    NASA Astrophysics Data System (ADS)

    Sapunov, Valentin; Glazyrina, Tatiana

    2016-04-01

    Since the beginning of the 21st century the number of disasters in the world increased approximately two times. Damage from disasters cost an average of 230 billion dollars per year. Recently, the death toll in the disaster has reached 230,000 - 1 000,000 per year. Along with earthquakes, tsunamis, floods, increased the number of forest and steppe fires. These processes are not fully known global, geophysical and space reasons. Of great importance are perennial not until the end of the study of natural cycles. There is evidence that the state of the planet's surface affect processes in the Earth's core. Understanding the causes and prediction of the tragic events require an integrated effort based on the synthesis of various sciences as well as history which has knowledge about the disasters of the past. Factor that reduces the risk is constant monitoring, including both distant and contact methods. However, its possibility is limited. Firstly, due to the high cost of global, especially space monitoring. Secondly, due to the unpredictability of some processes. In December 2004, the countries of Southeast Asia hit by the tsunami. The death gotten 250 000 people. Animals in this cataclysm appeared to stay safety and advance left the danger zone. Animals are able to predict hazards having no materials predecessors. Participants nuclear tests show - a day before the explosion of the animals escape dangerous zone. This means that animals have the ability to predict the catastrophic events. The most important abiotic factor, the physical nature of which is still not clear is time. One of the scientists, who achieved some success in the study of time, was N.Kozyrev (1908-1983). He devoted his life to the study of the phenomenon of time and attempt to systematize the knowledge of him as a physical substance. Kozyrev in his theoretical calculations and experiments found the new field - the field of time (chrono-information). Through it can instantly and accurately transmit

  1. Characterization of Natural Organic Matter in Alluvial Aquifer Sediments: Approaches and Implications for Reactivity

    NASA Astrophysics Data System (ADS)

    Fox, P. M.; Nico, P. S.; Hao, Z.; Gilbert, B.; Tfaily, M. M.; Devadoss, J.

    2015-12-01

    Sediment-associated natural organic matter (NOM) is an extremely complex assemblage of organic molecules with a wide range of sizes, functional groups, and structures, which is intricately associated with mineral particles. The chemical nature of NOM may control its' reactivity towards metals, minerals, enzymes, and bacteria. Organic carbon concentrations in subsurface sediments are typically much lower than in surface soils, posing a distinct challenge for characterization. In this study, we investigated NOM associated with shallow alluvial aquifer sediments in a floodplain of the Colorado River. Total organic carbon (TOC) contents in these subsurface sediments are typically around 0.1%, but can range from 0.03% up to approximately 1.5%. Even at the typical TOC values of 0.1%, the mass of sediment-associated OC is approximately 5000 times higher than the mass of dissolved OC, representing a large pool of carbon that may potentially be mobilized or degraded under changing environmental conditions. Sediment-associated OC is much older than both the depositional age of the alluvial sediments and dissolved OC in the groundwater, indicating that the vast majority of NOM was sequestered by the sediment long before it was deposited in the floodplain. We have characterized the sediment-bound NOM from two locations within the floodplain with differing physical and geochemical properties. One location has relatively low organic carbon (<0.2%) and is considered suboxic [dissolved oxygen is low or absent, but no dissolved Fe(II) observed], while the other is a naturally reducing zone with higher organic carbon (0.2-1.5%) and Fe(II)-reducing conditions. An extraction scheme was developed using a combination of sequential extraction [water and sodium pyrophosphate (pH 10)] and purification in order to isolate different fractions of sediment-associated NOM. Analysis of these different NOM fractions was then carried out by FTIR and ESI-FTICR-MS to allow for comparison of NOM

  2. Reducing Onshore Natural Gas and Oil Exploration and Production Impacts Using a Broad-Based Stakeholder Approach

    SciTech Connect

    Amy Childers

    2011-03-30

    Never before has the reduction of oil and gas exploration and production impacts been as important as it is today for operators, regulators, non-governmental organizations and individual landowners. Collectively, these stakeholders are keenly interested in the potential benefits from implementing effective environmental impact reducing technologies and practices. This research project strived to gain input and insight from such a broad array of stakeholders in order to identify approaches with the potential to satisfy their diverse objectives. The research team examined three of the most vital issue categories facing onshore domestic production today: (1) surface damages including development in urbanized areas, (2) impacts to wildlife (specifically greater sage grouse), and (3) air pollution, including its potential contribution to global climate change. The result of the research project is a LINGO (Low Impact Natural Gas and Oil) handbook outlining approaches aimed at avoiding, minimizing, or mitigating environmental impacts. The handbook identifies technical solutions and approaches which can be implemented in a practical and feasible manner to simultaneously achieve a legitimate balance between environmental protection and fluid mineral development. It is anticipated that the results of this research will facilitate informed planning and decision making by management agencies as well as producers of oil and natural gas. In 2008, a supplemental task was added for the researchers to undertake a 'Basin Initiative Study' that examines undeveloped and/or underdeveloped oil and natural gas resources on a regional or geologic basin scope to stimulate more widespread awareness and development of domestic resources. Researchers assessed multi-state basins (or plays), exploring state initiatives, state-industry partnerships and developing strategies to increase U.S. oil and gas supplies while accomplishing regional economic and environmental goals.

  3. An Approach to the Constrained Design of Natural Laminar Flow Airfoils

    NASA Technical Reports Server (NTRS)

    Green, Bradford E.

    1997-01-01

    A design method has been developed by which an airfoil with a substantial amount of natural laminar flow can be designed, while maintaining other aerodynamic and geometric constraints. After obtaining the initial airfoil's pressure distribution at the design lift coefficient using an Euler solver coupled with an integral turbulent boundary layer method, the calculations from a laminar boundary layer solver are used by a stability analysis code to obtain estimates of the transition location (using N-Factors) for the starting airfoil. A new design method then calculates a target pressure distribution that will increase the laminar flow toward the desired amount. An airfoil design method is then iteratively used to design an airfoil that possesses that target pressure distribution. The new airfoil's boundary layer stability characteristics are determined, and this iterative process continues until an airfoil is designed that meets the laminar flow requirement and as many of the other constraints as possible.

  4. An approach to the constrained design of natural laminar flow airfoils

    NASA Technical Reports Server (NTRS)

    Green, Bradford Earl

    1995-01-01

    A design method has been developed by which an airfoil with a substantial amount of natural laminar flow can be designed, while maintaining other aerodynamic and geometric constraints. After obtaining the initial airfoil's pressure distribution at the design lift coefficient using an Euler solver coupled with an integml turbulent boundary layer method, the calculations from a laminar boundary layer solver are used by a stability analysis code to obtain estimates of the transition location (using N-Factors) for the starting airfoil. A new design method then calculates a target pressure distribution that will increase the larninar flow toward the desired amounl An airfoil design method is then iteratively used to design an airfoil that possesses that target pressure distribution. The new airfoil's boundary layer stability characteristics are determined, and this iterative process continues until an airfoil is designed that meets the laminar flow requirement and as many of the other constraints as possible.

  5. Bacillus aryabhattai BA03: a novel approach to the production of natural value-added compounds.

    PubMed

    Paz, Alicia; Carballo, Julia; Pérez, María José; Domínguez, José Manuel

    2016-10-01

    A strain designated as BA03, with the ability to transform ferulic acid into vanillin and 4-vinylguaiacol, was isolated from contaminated cryovials. The production of natural value-added compounds was dependent on the media employed. The morphological and physiological characteristics of this strain were compared with those of the typical vanillin-producer strain Amycolatopsis sp. ATCC 39116. According to a partial 16S rRNA sequence, we determined that BA03 belonged to Bacillus aryabhattai. In addition, analysis of the results showed that this strain exhibited interesting enzymatic activity, including cellulases, laccases, lipases and pectinases. In light of this, we propose new functions for this multitasking microorganism. We suggest that it may be used for converting lignocellulosic wastes into byproducts with industrial uses, and also for treating disposal residues such as dyes in the textile industry. Hence, the possibility for novel research with B. aryabhattai opens up in the fields of biodegradation and/or revalorization of wastes.

  6. Estimating the hatchery fraction of a natural population: a Bayesian approach

    USGS Publications Warehouse

    Barber, Jarrett J.; Gerow, Kenneth G.; Connolly, Patrick J.; Singh, Sarabdeep

    2011-01-01

    There is strong and growing interest in estimating the proportion of hatchery fish that are in a natural population (the hatchery fraction). In a sample of fish from the relevant population, some are observed to be marked, indicating their origin as hatchery fish. The observed proportion of marked fish is usually less than the actual hatchery fraction, since the observed proportion is determined by the proportion originally marked, differential survival (usually lower) of marked fish relative to unmarked hatchery fish, and rates of mark retention and detection. Bayesian methods can work well in a setting such as this, in which empirical data are limited but for which there may be considerable expert judgment regarding these values. We explored a Bayesian estimation of the hatchery fraction using Monte Carlo–Markov chain methods. Based on our findings, we created an interactive Excel tool to implement the algorithm, which we have made available for free.

  7. Multistep Approach to Microscopic Models for Frustrated Quantum Magnets: The Case of the Natural Mineral Azurite

    NASA Astrophysics Data System (ADS)

    Jeschke, Harald; Opahle, Ingo; Kandpal, Hem; Valentí, Roser; Das, Hena; Saha-Dasgupta, Tanusri; Janson, Oleg; Rosner, Helge; Brühl, Andreas; Wolf, Bernd; Lang, Michael; Richter, Johannes; Hu, Shijie; Wang, Xiaoqun; Peters, Robert; Pruschke, Thomas; Honecker, Andreas

    2011-05-01

    The natural mineral azurite Cu3(CO3)2(OH)2 is a frustrated magnet displaying unusual and controversially discussed magnetic behavior. Motivated by the lack of a unified description for this system, we perform a theoretical study based on density functional theory as well as state-of-the-art numerical many-body calculations. We propose an effective generalized spin-1/2 diamond chain model which provides a consistent description of experiments: low-temperature magnetization, inelastic neutron scattering, nuclear magnetic resonance measurements, magnetic susceptibility as well as new specific heat measurements. With this study we demonstrate that the balanced combination of first principles with powerful many-body methods successfully describes the behavior of this frustrated material.

  8. Impact of textural anisotropy on syn-kinematic partial melting of natural gneisses: an experimental approach.

    NASA Astrophysics Data System (ADS)

    Ganzhorn, Anne-Céline; Trap, Pierre; Arbaret, Laurent; Champallier, Rémi; Fauconnier, Julien; Labrousse, Loic; Prouteau, Gaëlle

    2015-04-01

    Partial melting of continental crust is a strong weakening process controlling its rheological behavior and ductile flow of orogens. This strength weakening due to partial melting is commonly constrained experimentally on synthetic starting material with derived rheological law. Such analog starting materials are preferentially used because of their well-constrained composition to test the impact of melt fraction, melt viscosity and melt distribution upon rheology. In nature, incipient melting appears in particular locations where mineral and water contents are favorable, leading to stromatic migmatites with foliation-parallel leucosomes. In addition, leucosomes are commonly located in dilatants structural sites like boudin-necks, in pressure shadows, or in fractures within more competent layers of migmatites. The compositional layering is an important parameter controlling melt flow and rheological behavior of migmatite but has not been tackled experimentally for natural starting material. In this contribution we performed in-situ deformation experiments on natural rock samples in order to test the effect of initial gneissic layering on melt distribution, melt flow and rheological response. In-situ deformation experiments using a Paterson apparatus were performed on two partially melted natural gneissic rocks, named NOP1 & PX28. NOP1, sampled in the Western Gneiss Region (Norway), is biotite-muscovite bearing gneiss with a week foliation and no gneissic layering. PX28, sampled from the Sioule Valley series (French Massif Central), is a paragneiss with a very well pronounced layering with quartz-feldspar-rich and biotite-muscovite-rich layers. Experiments were conducted under pure shear condition at axial strain rate varying from 5*10-6 to 10-3 s-1. The main stress component was maintained perpendicular to the main plane of anisotropy. Confining pressure was 3 kbar and temperature ranges were 750°C and 850-900°C for NOP1 and PX28, respectively. For the 750

  9. Pulsed gas injection: a minimum effort approach for enhanced natural attenuation of chlorobenzene in contaminated groundwater.

    PubMed

    Balcke, Gerd Ulrich; Paschke, Heidrun; Vogt, Carsten; Schirmer, Mario

    2009-07-01

    Chlorobenzene-contaminated groundwater was used to assess pulsed gas sparging as a minimum effort aeration strategy to enhance intrinsic natural attenuation. In contrast to existing biosparging operations, oxygen was supplied at minimum rate by reducing the gas injection frequency to 0.33 day(-1). Field tests in a model aquifer were conducted in a 12 m long reactor, filled with indigenous aquifer material and continuously recharged with polluted groundwater over 3 years. The closed arrangement allowed yield balances, cost accounting as well as the investigation of spatial distributions of parameters which are sensitive to the biodegradation process. Depending on the injection frequency and on the gas chosen for injection (pure oxygen or air) oxygen-deficient conditions prevailed in the aquifer. Despite the limiting availability of dissolved oxygen in the groundwater, chlorobenzene degradation under oxygen-deficient conditions proved to be more effective than under conditions with dissolved oxygen being available in high concentrations.

  10. Science Teachers' Thinking About the Nature of Science: A New Methodological Approach to Its Assessment

    NASA Astrophysics Data System (ADS)

    Vázquez-Alonso, Ángel; García-Carmona, Antonio; Manassero-Mas, María Antonia; Bennàssar-Roig, Antoni

    2013-04-01

    This paper describes Spanish science teachers' thinking about issues concerning the nature of science (NOS) and the relationships connecting science, technology, and society (STS). The sample consisted of 774 in-service and pre-service teachers. The participants responded to a selection of items from the Questionnaire of Opinions on Science, Technology & Society in a multiple response model. These data were processed to generate the invariant indices that are used as the bases for subsequent quantitative and qualitative analyses. The overall results reflect moderately informed conceptions, and a detailed analysis by items, categories, and positions reveals a range of positive and negative conceptions about the topics of NOS dealt with in the questionnaire items. The implications of the findings for teaching and teacher training on the themes of NOS are discussed.

  11. Gauging the societal impacts of natural disasters using a capability approach.

    PubMed

    Gardoni, Paolo; Murphy, Colleen

    2010-07-01

    There is a widely acknowledged need for a single composite index that provides a comprehensive picture of the societal impact of disasters. A composite index combines and logically organizes important information policy-makers need to allocate resources for the recovery from natural disasters; it can also inform hazard mitigation strategies. This paper develops a Disaster Impact Index (DII) to gauge the societal impact of disasters on the basis of the changes in individuals' capabilities. The DII can be interpreted as the disaster impact per capita. Capabilities are dimensions of individual well-being and refer to the genuine opportunities individuals have to achieve valuable states and activities (such as being adequately nourished or being mobile). After discussing the steps required to construct the DII, this article computes and compares the DIIs for two earthquakes of similar magnitude in two societies at different levels of development and of two disasters (earthquake and wind storm) in the same society.

  12. El Dorado Air Quality Management District's Approach to Dealing With Naturally Occurring Asbestos (NOA) Hazards

    NASA Astrophysics Data System (ADS)

    Thomas, C.

    2012-12-01

    In 2005, Naturally Occurring Asbestos (NOA) in El Dorado County made headlines with the discovery significant amounts of tremolite/actinolite asbestos in areas where residents had built, or were in the process of building, homes and residences. The El Dorado Air Quality Management District has been involved in all aspects of dealing with NOA from the very beginning of its discovery, from overseeing the rehabilitation of school sites to expanding and rewriting fugitive dust rules at construction sites. A discussion of best management practices which have been developed will be given, as well as how the El Dorado Air Quality Management District has worked to educate members of the public, as well as workers in the field, about NOA to aid in maintaining the health and safety of the public.

  13. Tracing carbon uptake from a natural CO2 spring into tree rings: an isotope approach.

    PubMed

    Saurer, Matthias; Cherubini, Paolo; Bonani, Georges; Siegwolf, Rolf

    2003-10-01

    We analyzed 14C, 13C and 18O isotope variations over a 50-year period in tree rings of Quercus ilex L. trees growing at a natural CO2 spring in a Mediterranean ecosystem. We compared trees from two sites, one with high and one with low exposure to CO2 from the spring. The spring CO2 is free of 14C. Thus, this carbon can be traced in the wood, and the amount originating from the spring calculated. The amount decreased over time, from about 40% in 1950 to 15% at present for the site near the spring, indicating a potential difficulty in the use of natural CO2 springs for elevated CO2 research. The reason for the decrease may be decreasing emission from the spring or changes in stand structure, e.g., growth of the canopy into regions with lower concentrations. We used the 14C-calculated CO2 concentration in the canopy to determine the 13C discrimination of the plants growing under elevated CO2 by calculating the effective canopy air 13C/12C isotopic composition. The trees near the spring showed a 2.5 per thousand larger 13C discrimination than the more distant trees at the beginning of the investigated period, i.e., for the young trees, but this difference gradually disappeared. Higher discrimination under elevated CO2 indicated reduced photosynthetic capacity or increased stomatal conductance. The latter assumption is unlikely as inferred from the 18O data, which were insensitive to CO2 concentration. In conclusion, we found evidence for a downward adjustment of photosynthesis under elevated CO2 in Q. ilex in this dry, nutrient-poor environment.

  14. Cigarette smoke-mediated perturbations of the immune response: A new therapeutic approach with natural compounds.

    PubMed

    Magrone, Thea; Jirillo, Emilio

    2016-09-27

    Cigarette smoke (CS) accounts for the outcome of several pathologies, even including lung cancer, cardiovascular disease and chronic obstructive pulmonary disease (COPD). Under healthy conditions, lung immune system becomes tolerant in response to various external stimuli. CS exposure alters the pulmonary immune equilibrium, thus leading to a condition of hyper activation of the local innate and adaptive immunity. COPD is one of the major complications of chronic CS exposure where a pro-inflammatory profile of the pulmonary and systemic immunity is predominant. In this review, alternative treatments with natural products to mitigate CS-mediated pulmonary inflammation are proposed. In particular, polyphenols, a class of natural compounds largely present in fruits and vegetables, have been shown to act as anti-inflammatory agents. Accordingly, recent experimental and clinical evidences support polyphenol-mediated potential health benefits in smokers. For instance, pomegranate juice is able to attenuate the damage provoked by CS on cultured human alveolar macrophages. In addition, maqui beery extract has been proven to normalize H2O2 and interleukin-6 levels in exhaled breath condensate in healthy smokers. However, some limitations of alternative treatments are represented by a better knowledge of the mechanism(s) of action exerted by polyphenols and by the lack of animal models of COPD. In any case, the potential targets of polyphenols in the course of COPD will be outlined with special reference to the activation of T regulatory cells as well as to the inhibition of the polymorphonuclear cell and monocyte respiratory burst and of the NF-kB pathway, respectively.

  15. Climate zone delineation: evaluating approaches for use in natural resource management.

    PubMed

    Tercek, Michael T; Gray, Stephen T; Nicholson, Christopher M

    2012-05-01

    Recent efforts by the United States Department of the Interior (DOI) have the potential to make climate zones the basic geographic units guiding monitoring and resource management programs in the western U.S. We evaluated a new National Park Service approach for delineating climate zones that will likely be a model for other DOI agencies. Using the test case of the Greater Yellowstone Area in Wyoming, Montana and Idaho, we conducted three separate analyses, each based on a different dataset. Cluster analysis of 1971-2000 temperature and precipitation normals grouped weather stations according to similarities in seasonal patterns. Principal Components Analysis (PCAs) of 1895-2008 monthly data grouped stations by similarities in long-term variability. Finally, an analysis of snow data further subdivided the zones defined by the other two analyses. The climate zones produced by the cluster analysis and the PCAs were roughly similar to each other, but the differences were significant. The two sets of zones may be useful for different applications. For example, studies that analyze links between climate patterns and the demography of threatened species should focus on the results of the PCAs. The broad similarity among results produced by the different approaches supported the application of these zones in climate-related monitoring and analysis. However, since choices in data and methodology can affect the details of maps depicting zone boundaries, there are practical limitations to their use.

  16. Multi-choice stochastic bi-level programming problem in cooperative nature via fuzzy programming approach

    NASA Astrophysics Data System (ADS)

    Maiti, Sumit Kumar; Roy, Sankar Kumar

    2016-05-01

    In this paper, a Multi-Choice Stochastic Bi-Level Programming Problem (MCSBLPP) is considered where all the parameters of constraints are followed by normal distribution. The cost coefficients of the objective functions are multi-choice types. At first, all the probabilistic constraints are transformed into deterministic constraints using stochastic programming approach. Further, a general transformation technique with the help of binary variables is used to transform the multi-choice type cost coefficients of the objective functions of Decision Makers(DMs). Then the transformed problem is considered as a deterministic multi-choice bi-level programming problem. Finally, a numerical example is presented to illustrate the usefulness of the paper.

  17. A person-centered approach to the multifaceted nature of young adult sexual behavior.

    PubMed

    McGuire, Jenifer K; Barber, Bonnie L

    2010-07-01

    Young adult sexual relationships were examined using a multifaceted, person-centered approach with data from Wave 7 (aged 20-21; N = 1,126) of the Michigan Study of Adolescent Life Transitions. The study utilized hierarchical cluster analyses based on the following measured variables: frequency of sex, importance of regularly having sex, satisfaction with sex life, experience of coercion for sex, and sexual risk reduction. Five distinct clusters emerged for females (Satisfied, Moderate, Active Unprotected, Pressured, and Inactive) and represented patterns such as more partners paired with less risk reduction (Active Unprotected), high satisfaction paired with frequent sex and high-risk reduction (Satisfied), or higher levels of coercion paired with low satisfaction and low-risk reduction (Pressured). Similar clusters emerged for males, with one additional cluster: the Dissatisfied cluster. Clusters differed with respect to relationship status, marital status, and psychological well-being (both males and females) and parental divorce, living situation, and sexual orientation (females only).

  18. Lessons from Nature: A Bio-Inspired Approach to Molecular Design

    PubMed Central

    Cook, Sarah A.; Hill, Ethan A.; Borovik, A. S.

    2015-01-01

    Metalloproteins contain actives sites with intricate structures that perform specific functions with high selectivity and efficiency. The complexity of these systems complicates the study of their function and the understanding of the properties that give rise to their reactivity. One approach that has contributed to the current level of understanding of their biological function is the study of synthetic constructs that mimic one or more aspects of the native metalloproteins. These systems allow individual contributions to the structure and function to be analyzed and also permit spectroscopic characterization of the metal cofactors without complications from the protein environment. This Current Topics is a review of synthetic constructs as probes for understanding the biological activation of small molecules. These topics are developed from the perspective of seminal molecular design breakthroughs from the past that provide the foundation for the systems used today. PMID:26079379

  19. Economic optimization of natural hazard protection - conceptual study of existing approaches

    NASA Astrophysics Data System (ADS)

    Spackova, Olga; Straub, Daniel

    2013-04-01

    Risk-based planning of protection measures against natural hazards has become a common practice in many countries. The selection procedure aims at identifying an economically efficient strategy with regard to the estimated costs and risk (i.e. expected damage). A correct setting of the evaluation methodology and decision criteria should ensure an optimal selection of the portfolio of risk protection measures under a limited state budget. To demonstrate the efficiency of investments, indicators such as Benefit-Cost Ratio (BCR), Marginal Costs (MC) or Net Present Value (NPV) are commonly used. However, the methodologies for efficiency evaluation differ amongst different countries and different hazard types (floods, earthquakes etc.). Additionally, several inconsistencies can be found in the applications of the indicators in practice. This is likely to lead to a suboptimal selection of the protection strategies. This study provides a general formulation for optimization of the natural hazard protection measures from a socio-economic perspective. It assumes that all costs and risks can be expressed in monetary values. The study regards the problem as a discrete hierarchical optimization, where the state level sets the criteria and constraints, while the actual optimization is made on the regional level (towns, catchments) when designing particular protection measures and selecting the optimal protection level. The study shows that in case of an unlimited budget, the task is quite trivial, as it is sufficient to optimize the protection measures in individual regions independently (by minimizing the sum of risk and cost). However, if the budget is limited, the need for an optimal allocation of resources amongst the regions arises. To ensure this, minimum values of BCR or MC can be required by the state, which must be achieved in each region. The study investigates the meaning of these indicators in the optimization task at the conceptual level and compares their

  20. Untangling Natural Seascape Variation from Marine Reserve Effects Using a Landscape Approach

    PubMed Central

    Huntington, Brittany E.; Karnauskas, Mandy; Babcock, Elizabeth A.; Lirman, Diego

    2010-01-01

    Distinguishing management effects from the inherent variability in a system is a key consideration in assessing reserve efficacy. Here, we demonstrate how seascape heterogeneity, defined as the spatial configuration and composition of coral reef habitats, can mask our ability to discern reserve effects. We then test the application of a landscape approach, utilizing advances in benthic habitat mapping and GIS techniques, to quantify this heterogeneity and alleviate the confounding influence during reserve assessment. Seascape metrics were quantified at multiple spatial scales using a combination of spatial image analysis and in situ surveys at 87 patch reef sites in Glover's Reef Lagoon, Belize, within and outside a marine reserve enforced since 1998. Patch reef sites were then clustered into classes sharing similar seascape attributes using metrics that correlated significantly to observed variations in both fish and coral communities. When the efficacy of the marine reserve was assessed without including landscape attributes, no reserve effects were detected in the diversity and abundance of fish and coral communities, despite 10 years of management protection. However, grouping sites based on landscape attributes revealed significant reserve effects between site classes. Fish had higher total biomass (1.5×) and commercially important biomass (1.75×) inside the reserve and coral cover was 1.8 times greater inside the reserve, though direction and degree of response varied by seascape class. Our findings show that the application of a landscape classification approach vastly improves our ability to evaluate the efficacy of marine reserves by controlling for confounding effects of seascape heterogeneity and suggests that landscape heterogeneity should be considered in future reserve design. PMID:20808833

  1. Regulation of emotion in ADHD: can children with ADHD override the natural tendency to approach positive and avoid negative pictures?

    PubMed

    Van Cauwenberge, Valerie; Sonuga-Barke, Edmund J S; Hoppenbrouwers, Karel; Van Leeuwen, Karla; Wiersema, Jan R

    2017-03-01

    Studies have demonstrated inefficient use of antecedent-focused emotion regulation strategies in children with ADHD attention-deficit/hyperactivity disorder (ADHD). In the current study we tested for the first time if ADHD is also associated with difficulties in response-focused strategies by measuring the ability to override action tendencies induced by emotional information. Performance data on a computer-based approach-avoidance paradigm of 28 children with ADHD and 38 typically developing children between 8 and 15 years of age were analyzed, by comparing a congruent condition in which they were instructed to approach positive and avoid negative pictures and an incongruent condition where they had to override these automatic reactions and approach negative and avoid positive pictures. Children also rated the valence and salience of the pictures. Children with ADHD and typically developing children rated the emotional valence of the pictures appropriately and similarly, while positive pictures were rated as more arousing by children with ADHD. Solid congruency effects were found indicating that the task measured response-focused emotion regulation; however groups did not differ in this respect. Our findings do not support a deficit in emotion regulation in ADHD in terms of the ability to override natural tendencies to approach positive and avoid negative pictures.

  2. An explicit and reflective approach to the use of history to promote understanding of the nature of science

    NASA Astrophysics Data System (ADS)

    Rudge, David W.; Howe, Eric M.

    2009-05-01

    Monk and Osborne (Sci Educ 81:405-424, 1997) provide a rigorous justification for why history and philosophy of science should be incorporated as an integral component of instruction and a model for how history of science should be used to promote learning of and about science. In the following essay we critique how history of science is used on this model, and in particular, their advocacy of a direct comparison of students’ conceptions of scientific phenomena with those of past scientists. We propose instead an alternative approach that promotes a more active engagement by inviting students to engage in the sort of reasoning that led past scientists to reach insights about scientific phenomena. As an example we describe in detail two lesson plans taken from an eight-class unit developed with reference to the history of research on sickle-cell anemia. These lessons demonstrate how an open-ended, problem-solving approach can be used to help students deepen their understanding of science. Throughout the unit students are invited to explicitly and reflectively consider the implications of their reasoning about the disease for their understanding of nature of science issues. The essay draws attention to how this alternative approach actually more closely aligns with the constructivist rationale Monk and Osborne have articulated. It concludes with a brief summary of empirical research demonstrating the efficacy of this approach.

  3. Statistical approaches to paternity analysis in natural populations and applications to the North Atlantic humpback whale.

    PubMed

    Nielsen, R; Mattila, D K; Clapham, P J; Palsbøll, P J

    2001-04-01

    We present a new method for paternity analysis in natural populations that is based on genotypic data that can take the sampling fraction of putative parents into account. The method allows paternity assignment to be performed in a decision theoretic framework. Simulations are performed to evaluate the utility and robustness of the method and to assess how many loci are necessary for reliable paternity inference. In addition we present a method for testing hypotheses regarding relative reproductive success of different ecologically or behaviorally defined groups as well as a new method for estimating the current population size of males from genotypic data. This method is an extension of the fractional paternity method to the case where only a proportion of all putative fathers have been sampled. It can also be applied to provide abundance estimates of the number of breeding males from genetic data. Throughout, the methods were applied to genotypic data collected from North Atlantic humpback whales (Megaptera novaeangliae) to test if the males that appear dominant during the mating season have a higher reproductive success than the subdominant males.

  4. Predictions and simulations of cortical dynamics during natural sleep using a continuum approach

    NASA Astrophysics Data System (ADS)

    Wilson, M. T.; Steyn-Ross, M. L.; Steyn-Ross, D. A.; Sleigh, J. W.

    2005-11-01

    In this paper we use a continuum model in two spatial dimensions to study the dynamics of the cortex during natural sleep, including explicitly the effects of two key neuromodulators. The model predicts that a number of states could be available to the cortex. We identify two of these with slow-wave sleep and rapid eye movement (REM) sleep, and focus on the transition between the two. Eigenvalue analysis of the linearized model, together with simulations on a two-dimensional grid, show that a number of oscillatory states exist; the occurrence of these is particularly dependent upon the duration in time of the inhibitory postsynaptic potential. These oscillatory states are similar to the cortical slow oscillation and certain types of seizure. Power spectra are evaluated for different parameter sets and compare favorably with experiment. Grid simulations show that transitions between cortical states (e.g., slow-wave to REM) can be seeded at any point in space by random fluctuations in subcortical input.

  5. Predictions and simulations of cortical dynamics during natural sleep using a continuum approach.

    PubMed

    Wilson, M T; Steyn-Ross, M L; Steyn-Ross, D A; Sleigh, J W

    2005-11-01

    In this paper we use a continuum model in two spatial dimensions to study the dynamics of the cortex during natural sleep, including explicitly the effects of two key neuromodulators. The model predicts that a number of states could be available to the cortex. We identify two of these with slow-wave sleep and rapid eye movement (REM) sleep, and focus on the transition between the two. Eigenvalue analysis of the linearized model, together with simulations on a two-dimensional grid, show that a number of oscillatory states exist; the occurrence of these is particularly dependent upon the duration in time of the inhibitory postsynaptic potential. These oscillatory states are similar to the cortical slow oscillation and certain types of seizure. Power spectra are evaluated for different parameter sets and compare favorably with experiment. Grid simulations show that transitions between cortical states (e.g., slow-wave to REM) can be seeded at any point in space by random fluctuations in subcortical input.

  6. A simple approach for morphology tailoring of alginate particles by manipulation ionic nature of polyurethanes.

    PubMed

    Daemi, Hamed; Barikani, Mehdi; Barmar, Mohammad

    2014-05-01

    A number of different ionic aqueous polyurethane dispersions (PUDs) were synthesized based on NCO-terminated prepolymers. Two different anionic and cationic polyurethane samples were synthesized using dimethylol propionic acid and N-methyldiethanolamine emulsifiers, respectively. Then, proper amounts of PUDs and sodium alginate were mixed to obtain a number of aqueous polyurethane dispersions-sodium alginate (PUD/SA) elastomers. The chemical structure, thermal, morphological, thermo-mechanical and mechanical properties, and hydrophilicity content of the prepared samples were studied by FTIR, EDX, DSC, TGA, SEM, DMTA, tensile testing and contact angle techniques. The cationic polyurethanes and their blends with sodium alginate showed excellent miscibility and highly stretchable properties, while the samples containing anionic polyurethanes and alginate illustrated a poor compatibility and no significant miscibility. The morphology of alginate particles shifted from nanoparticles to microparticles by changing the nature of PUDs from cationic to anionic types. The final cationic elastomers not only showed better mechanical properties but also were formulated easier than anionic samples.

  7. Hydro-geomorphic approaches to designing nature-based flood and drought management schemes

    NASA Astrophysics Data System (ADS)

    Hetherington, David; Large, Andy; Quinn, Paul

    2016-04-01

    The need for nature-based solutions to runoff management is more pressing than ever. If it is possible to calculate how much water needs to be managed and where the opportunities are in the landscape, then it would be a significant step forward in water resources management. Here we will show how basic hydro-geomorphic indices can guide a catchment manager in identifying the types of intervention that are appropriate at different scales. Using runoff management zones can provide key ecosystems services that make the whole catchment system function better. The key indicators are: a) The Topographic Wetness Index, for use in small catchment and on hillslopes for identifying overland flow pathways that can be managed to store and disconnect fast runoff; b) Strahler stream order to show which small channels can be directly managed to slow, store and filter flow and c) Geomorphic Indices that estimate the floodplain extent, related to stream order, where flood storage zones could be created to hold back large amounts of water. Estimating how much flood water and sediment can be managed by the addition of runoff attenuation features in a landscape could be very important to policy makers. If enough water can be stored in small, medium and extreme events, then the more severe issues of floods, pollution and drought could potentially be addressed, obviating calls for ever bigger and more complex flood protection schemes.

  8. α-glucosidase inhibitors from plants: A natural approach to treat diabetes

    PubMed Central

    Kumar, Sunil; Narwal, Smita; Kumar, Vipin; Prakash, Om

    2011-01-01

    Diabetes is a common metabolic disease characterized by abnormally high plasma glucose levels, leading to major complications, such as diabetic neuropathy, retinopathy, and cardiovascular diseases. One of the effective managements of diabetes mellitus, in particular, non–insulin-dependent diabetes mellitus (NIDDM) to decrease postprandial hyperglycemia, is to retard the absorption of glucose by inhibition of carbohydrate hydrolyzing enzymes, such as α-glucosidase and α-amylase, in the digestive organs. α-Glucosidase is the key enzyme catalyzing the final step in the digestive process of carbohydrates. Hence, α-glucosidase inhibitors can retard the liberation of d-glucose from dietary complex carbohydrates and delay glucose absorption, resulting in reduced postprandial plasma glucose levels and suppression of postprandial hyperglycemia. In recent years, many efforts have been made to identify effective α-glucosidase inhibitors from natural sources in order to develop a physiologic functional food or lead compounds for use against diabetes. Many α-glucosidase inhibitors that are phytoconstituents, such as flavonoids, alkaloids, terpenoids,anthocyanins, glycosides, phenolic compounds, and so on, have been isolated from plants. In the present review, we focus on the constituents isolated from different plants having α-glucosidase inhibitory potency along with IC50 values. PMID:22096315

  9. Statistical approaches to paternity analysis in natural populations and applications to the North Atlantic humpback whale.

    PubMed Central

    Nielsen, R; Mattila, D K; Clapham, P J; Palsbøll, P J

    2001-01-01

    We present a new method for paternity analysis in natural populations that is based on genotypic data that can take the sampling fraction of putative parents into account. The method allows paternity assignment to be performed in a decision theoretic framework. Simulations are performed to evaluate the utility and robustness of the method and to assess how many loci are necessary for reliable paternity inference. In addition we present a method for testing hypotheses regarding relative reproductive success of different ecologically or behaviorally defined groups as well as a new method for estimating the current population size of males from genotypic data. This method is an extension of the fractional paternity method to the case where only a proportion of all putative fathers have been sampled. It can also be applied to provide abundance estimates of the number of breeding males from genetic data. Throughout, the methods were applied to genotypic data collected from North Atlantic humpback whales (Megaptera novaeangliae) to test if the males that appear dominant during the mating season have a higher reproductive success than the subdominant males. PMID:11290722

  10. Natural orbitals renormalization group approach to the two-impurity Kondo critical point

    NASA Astrophysics Data System (ADS)

    He, Rong-Qiang; Dai, Jianhui; Lu, Zhong-Yi

    2015-04-01

    The problem of two magnetic impurities in a normal metal exposes the two opposite tendencies in the formation of a singlet ground state, driven respectively by the single-ion Kondo effect with conduction electrons to screen impurity spins or the Ruderman-Kittel-Kasuya-Yosida interaction between the two impurities to directly form impurity spin singlet. However, whether the competition between these two tendencies can lead to a quantum critical point has been debated over more than two decades. Here, we study this problem by applying the newly proposed natural orbitals renormalization group method to a lattice version of the two-impurity Kondo model with a direct exchange K between the two impurity spins. The method allows for unbiased access to the ground state wave functions and low-lying excitations for sufficiently large system sizes. We demonstrate the existence of a quantum critical point, characterized by the power-law divergence of impurity staggered susceptibility with critical exponent γ =0.60 (1 ) , on the antiferromagnetic side of K when the interimpurity distance R is even lattice spacing, while a crossover behavior is recovered when R is odd lattice spacing. These results have ultimately resolved the long-standing discrepancy between the numerical renormalization group and quantum Monte Carlo studies, confirming a link of this two-impurity Kondo critical point to a hidden particle-hole symmetry predicted by the local Fermi liquid theory.

  11. Thermodynamic approach to oxygen delivery in vivo by natural and artificial oxygen carriers.

    PubMed

    Bucci, Enrico

    2009-06-01

    Oxygen is a toxic gas, still indispensable to aerobic life. This paper explores how normal physiology uses the physico-chemical and thermodynamic characteristics of oxygen for transforming a toxic gas into a non toxic indispensable metabolite. Plasma oxygen concentration is in the range of 10(-5) M, insufficient to sustain metabolism. Oxygen carriers, present in blood, release oxygen into plasma, thereby replacing consumed oxygen and buffering PO(2) near their P(50). They are the natural cell-bound carriers, like hemoglobin inside red cells, myoglobin inside myocytes, and artificial cell-free hemoglobin-based oxygen carriers (HBOC) dissolved in plasma. Metabolic oxygen replacement can be defined as cell-bound and cell-free delivery. Cell-bound delivery is retarded by the slow diffusion of oxygen in plasma and interstitial fluids. The 40% hematocrit of normal blood compensates for the delay, coping with the fast oxygen consumption by mitochondria. Facilitated oxygen diffusion by HBOCs corrects for the slow diffusion, making cell-free delivery relatively independent from P(50). At all oxygen affinities, HBOCs produce hyperoxygenations that are compensated by vasoconstrictions. There is a strict direct correlation between the rate of oxygen replacement and hemoglobin content of blood. The free energy loss of the gradient adds a relevant regulation of tissues oxygenation. Oxygen is retained intravascularly by the limited permeability to gases of vessel walls.

  12. A layer-by-layer approach to natural polymer-derived bioactive coatings on magnesium alloys.

    PubMed

    Kunjukunju, Sangeetha; Roy, Abhijit; Ramanathan, Madhumati; Lee, Boeun; Candiello, Joe E; Kumta, Prashant N

    2013-11-01

    The development of polyelectrolyte multilayered coatings on magnesium alloy substrates that can be used for controlled delivery of growth factors and required biomolecules from the surface of these degradable implants could have a significant impact in the field of bone tissue regeneration. The current work reports on the fabrication of multilayered coatings of alginate and poly-L-lysine on alkaline- and fluoride-pretreated AZ31 substrates using a layer-by-layer (LbL) technique under physiological conditions. Furthermore, these coatings were surface functionalized by chemical cross-linking and fibronectin immobilization, and the resultant changes in surface properties have been shown to influence the cellular activity of these multilayered films. The physicochemical characteristics of these coated substrates have been investigated using attenuated total reflectance Fourier transform infrared spectroscopy, atomic force microscopy, scanning electron microscopy and energy-dispersive X-ray spectroscopy. Cytocompatibility studies using MC3T3-E1 osteoblasts show that the fluoride-pretreated, cross-linked and fibronectin-immobilized LbL-coated substrates are more bioactive and less cytotoxic than the hydroxide-pretreated, cross-linked and fibronectin-immobilized LbL-coated samples. The in vitro degradation results show that the multilayered coatings of these natural polysaccharide- and synthetic polyamino acid-based polyelectrolytes do not alter the degradation kinetics of the substrates; however, the pretreatment conditions have a significant impact on the overall coating degradation behavior. These preliminary results collectively show the potential use of LbL coatings on magnesium-based degradable scaffolds to improve their surface bioactivity.

  13. Stage-discharge prediction in natural rivers using an innovative approach

    NASA Astrophysics Data System (ADS)

    Maghrebi, Mahmoud F.; Ahmadi, Arash

    2017-02-01

    Determination of stage-discharge relationships in natural rivers is extremely important in flood control projects. Observational data at various stages cannot be collected simultaneously. It may take a considerable amount of time and a great deal of difficulty to collect the data required for establishing the rating curves. The main purpose of the current paper is to estimate the discharge using the concept of isovel contours with the corresponding hydro-geometric parameters of the cross sections which was first introduced by Maghrebi (2006). Although the accuracy of the contours is not very high, it is believed that when the sum of the whole cross sectional contour values is used as a single parameter in the proposed relationship the accuracy of discharge estimation is surprisingly high. A relationship based on dimensional analysis is used to interrelate the discharges at two different stages by simply using the geometrical parameters such the cross-sectional area, wetted perimeter, the width of the free surface and a quantity which is related to the summations of isovel contours. Then, the most accurate relationship that is obtained by minimization of the differences between the calculated and analytical discharges at two different stages is introduced. For verification, the results of the proposed method are compared with the observed stage-discharge data taken from the Main and Severn rivers in UK, the Tomebamba River in Ecuador and the Yangtze River in China. The results indicate the high accuracy of the proposed method such that the mean values of MAPE and NRMSE of all selected rivers do not exceed 8.7% and 0.09, respectively.

  14. [A new strategy for preventive and functional therapeutic methods for dementia--approach using natural products].

    PubMed

    Ohizumi, Yasushi

    2015-01-01

    Alzheimer's disease (AD) has become a serious social problem in Japan. However, effective preventive and fundamental therapeutic methods for AD have not yet been developed. Using a new strategy in the course of our survey of numerous natural resouces having neurotrophic activity, we isolated a variety of active constituents and proved their pharmacological properties. As a result, we successfully found nobiletin, a compound with anti-dementia activity that comes from citrus peels. Also, we have demonstrated that nobiletin ameliorates cognitive impairment in several dementia model animals such as chronically amyloid β(Aβ) infused rats, amyloid precursor protein transgenic (APPTg) mice, olfactory-bulbectomized (OBX) mice, N-methyl-D-aspartate (NMDA) receptor antagonist (MK-801)-treated mice, senescence-accelated mice and bilaterial common carotid arteries occlusion mice. In a APPTg mouse of AD, nobiletin greatly improved memory impairment, and this was accompanied by a marked decrease in Aβ deposition. Also, in OBX mice memory impairment was markedly recoverd by nobiletin, accompanied by improvement of a decrease indensity of cholinergic neurons. Interestingly, nobiletin improves age-related congnitive impairment and decreased hyperphosphorylation of tau as well as oxidative stress in senescence-accelerated mice. In cultured cells, nobiletin reversed the Aβ-induced inhibition of glutamate-induced increases in cAMP response element binding protein (CREB) phosphorylation and modulated gen expression of thioredoxin-interacting protein and NMDA resceptor subunits. These results suggest that nobiletin prevents memory impairment and exhibits a protecting action against neurodgeneration in AD model animals. Nobiletin and citrus peels thus have potential as functional foods for prevention of dementia.

  15. Approaches to Climate Literacy at the American Museum of Natural History

    NASA Astrophysics Data System (ADS)

    Steiner, R. V.

    2015-12-01

    The American Museum of Natural History (AMNH) offers a suite of courses, workshops and special events in climate change education for audiences ranging from young children to adults and utilizing both online and in-person formats. These offerings are supported by rich digital resources including video, animations and data visualizations. These efforts have the potential to raise awareness of climate change, deepen understandings and improve public discourse and decision-making on this critical issue. For adult audiences, Our Earth's Future offers participants a five-week course at AMNH that focuses on climate change science, impacts and communication, taking advantage of both AMNH expertise and exhibitry. Online versions of this course include both a ten-week course as well as three different three-week thematic courses. (The longer course is now available as a MOOC in Coursera.) These activities have been supported by a grant from IMLS. The results of independent evaluation provide insight into participant needs and how they might be addressed. For K-12 educators, the Museum's Seminars on Science program of online teacher professional development offers, in collaboration with its higher education partners, a graduate course in climate change that is authored by both an AMNH curator and leading NASA scientists. Developed with support from both NASA and NSF, the course provides a semester-equivalent introduction to climate change science for educators, including digital resources, assignments and discussions for classroom use. The results of independent evaluation will be presented. For younger audiences, the presentation will highlight resources from the AMNH Ology site; television programming conducted in partnership with HBO; Science Bulletinsvideos that include current climate change research; resources related to the GRACE mission for tracking water from space; and special event programming at the Museum on climate change. This presentation will address the

  16. The nature and dynamics of world religions: a life-history approach.

    PubMed

    Baumard, Nicolas; Chevallier, Coralie

    2015-11-07

    In contrast with tribal and archaic religions, world religions are characterized by a unique emphasis on extended prosociality, restricted sociosexuality, delayed gratification and the belief that these specific behaviours are sanctioned by some kind of supernatural justice. Here, we draw on recent advances in life history theory to explain this pattern of seemingly unrelated features. Life history theory examines how organisms adaptively allocate resources in the face of trade-offs between different life-goals (e.g. growth versus reproduction, exploitation versus exploration). In particular, recent studies have shown that individuals, including humans, adjust their life strategy to the environment through phenotypic plasticity: in a harsh environment, organisms tend to adopt a 'fast' strategy, pursuing smaller but more certain benefits, while in more affluent environments, organisms tend to develop a 'slow' strategy, aiming for larger but less certain benefits. Reviewing a range of recent research, we show that world religions are associated with a form of 'slow' strategy. This framework explains both the promotion of 'slow' behaviours such as altruism, self-regulation and monogamy in modern world religions, and the condemnation of 'fast' behaviours such as selfishness, conspicuous sexuality and materialism. This ecological approach also explains the diffusion pattern of world religions: why they emerged late in human history (500-300 BCE), why they are currently in decline in the most affluent societies and why they persist in some places despite this overall decline.

  17. The nature and dynamics of world religions: a life-history approach

    PubMed Central

    Baumard, Nicolas; Chevallier, Coralie

    2015-01-01

    In contrast with tribal and archaic religions, world religions are characterized by a unique emphasis on extended prosociality, restricted sociosexuality, delayed gratification and the belief that these specific behaviours are sanctioned by some kind of supernatural justice. Here, we draw on recent advances in life history theory to explain this pattern of seemingly unrelated features. Life history theory examines how organisms adaptively allocate resources in the face of trade-offs between different life-goals (e.g. growth versus reproduction, exploitation versus exploration). In particular, recent studies have shown that individuals, including humans, adjust their life strategy to the environment through phenotypic plasticity: in a harsh environment, organisms tend to adopt a ‘fast' strategy, pursuing smaller but more certain benefits, while in more affluent environments, organisms tend to develop a ‘slow' strategy, aiming for larger but less certain benefits. Reviewing a range of recent research, we show that world religions are associated with a form of ‘slow' strategy. This framework explains both the promotion of ‘slow' behaviours such as altruism, self-regulation and monogamy in modern world religions, and the condemnation of ‘fast' behaviours such as selfishness, conspicuous sexuality and materialism. This ecological approach also explains the diffusion pattern of world religions: why they emerged late in human history (500–300 BCE), why they are currently in decline in the most affluent societies and why they persist in some places despite this overall decline. PMID:26511055

  18. Neurolinguistic approach to natural language processing with applications to medical text analysis.

    PubMed

    Duch, Włodzisław; Matykiewicz, Paweł; Pestian, John

    2008-12-01

    Understanding written or spoken language presumably involves spreading neural activation in the brain. This process may be approximated by spreading activation in semantic networks, providing enhanced representations that involve concepts not found directly in the text. The approximation of this process is of great practical and theoretical interest. Although activations of neural circuits involved in representation of words rapidly change in time snapshots of these activations spreading through associative networks may be captured in a vector model. Concepts of similar type activate larger clusters of neurons, priming areas in the left and right hemisphere. Analysis of recent brain imaging experiments shows the importance of the right hemisphere non-verbal clusterization. Medical ontologies enable development of a large-scale practical algorithm to re-create pathways of spreading neural activations. First concepts of specific semantic type are identified in the text, and then all related concepts of the same type are added to the text, providing expanded representations. To avoid rapid growth of the extended feature space after each step only the most useful features that increase document clusterization are retained. Short hospital discharge summaries are used to illustrate how this process works on a real, very noisy data. Expanded texts show significantly improved clustering and may be classified with much higher accuracy. Although better approximations to the spreading of neural activations may be devised a practical approach presented in this paper helps to discover pathways used by the brain to process specific concepts, and may be used in large-scale applications.

  19. Plant-based antimicrobial studies--methods and approaches to study the interaction between natural products.

    PubMed

    van Vuuren, Sandy; Viljoen, Alvaro

    2011-07-01

    The therapeutic value of synergistic interactions has been known since antiquity, and many different cultural healing systems still rely on this principle in the belief that combination therapy may enhance efficacy. This paper intends to provide an overview, from an antimicrobial perspective, on the research undertaken and interactive principles involved in pharmacognosy studies. Methods used to determine antimicrobial interactions include basic combination studies, the sum of the fractional inhibitory concentration index (ΣFIC), isobole interpretations, and death kinetic (time-kill) assays. The various interactions are discussed with reference to molecules, different plant parts or fractions, different plant species, and combinations with nonbotanical antimicrobial agents. It is recommended for future development in the field of phytosynergy that consideration should be given to the selection criteria for the two inhibitors. A more conservative approach should be adopted when classifying synergy. When examining interactions in plant-based studies, antagonistic interactions should not be ignored. Combinations involving more than two test samples should be examined where applicable, and very importantly, the mechanism of action of synergistic interactions should be given precedence. It is encouraging to observe the upsurge in papers exploring the complex interactions of medicinal plants, and undoubtedly this will become increasingly important in our continued quest to understand the mechanism of action of phytotherapy. The scientific validation of efficacious antimicrobial combinations could lead to patentable entities making research in the field of phytosynergy not only academically rewarding but also commercially relevant.

  20. Assessing the Dietary Bioavailability of Metals Associated with Natural Particles: Extending the Use of the Reverse Labeling Approach to Zinc.

    PubMed

    Croteau, Marie-Noële; Cain, Daniel J; Fuller, Christopher C

    2017-02-22

    We extend the use of a novel tracing technique to quantify the bioavailability of zinc (Zn) associated with natural particles using snails enriched with a less common Zn stable isotope. Lymnaea stagnalis is a model species that has relatively fast Zn uptake rates from the dissolved phase, enabling their rapid enrichment in (67)Zn during the initial phase of labeling. Isotopically enriched snails were subsequently exposed to algae mixed with increasing amounts of metal-rich particles collected from two acid mine drainage impacted rivers. Zinc bioavailability from the natural particles was inferred from calculations of (66)Zn assimilation into the snail's soft tissues. Zinc assimilation efficiency (AE) varied from 28% for the Animas River particles to 45% for the Snake River particles, indicating that particle-bound, or sorbed Zn, was bioavailable from acid mine drainage wastes. The relative binding strength of Zn sorption to the natural particles was inversely related to Zn bioavailability; a finding that would not have been possible without using the reverse labeling approach. Differences in the chemical composition of the particles suggest that their geochemical properties may influence the extent of Zn bioavailability.

  1. Deciphering the elusive nature of sharp bone trauma using epifluorescence macroscopy: a comparison study multiplexing classical imaging approaches.

    PubMed

    Capuani, Caroline; Rouquette, Jacques; Payré, Bruno; Moscovici, Jacques; Delisle, Marie Bernadette; Telmon, Norbert; Guilbeau-Frugier, Céline

    2013-01-01

    Characterization of sharp-force trauma on human bones can be extremely useful in providing information regarding the nature and context of death. Nevertheless, in the identification of weapons used to cause sharp-force trauma and analysis of bone wounds, challenging tasks still remain. Current analysis attempting to dissect bone wound characteristics varied quite a lot and mixed different criteria, thus leading sometimes to conflicting results. In this context, the aim of our study is to clarify qualitative aspects of cut marks induced by sharp weapons on human bones. For that purpose, we analyzed bone samples via an original approach based on bone autofluorescence with an epifluorescence macroscope and compared it to previous existing methods. In this study, we used bone sections from human clavicles on which three different kinds of lesions were manually implemented, using different weapons. The bone wounds were analyzed by three different methodologies, light microscopy, scanning electron microscopy (SEM), and micro-computed tomography, and were compared with epifluorescence macroscopy. We paid attention more significantly to the aspect of walls and floor of the kerf, so as to conclude on the nature and distinguish between weapons used. Among all technologies used in this study, the most precise and efficient methods were epifluorescence macroscopy and SEM. Nonetheless, epifluorescence macroscopy is faster, cheaper, and more accessible than SEM. More significantly, this technique, which has the potential to accurately document the nature of the damage, is nondestructive, and could thus be highly useful in forensic science as anthropology.

  2. Natural antioxidants in the treatment and prevention of diabetic nephropathy; a potential approach that warrants clinical trials.

    PubMed

    Al-Waili, Noori; Al-Waili, Hamza; Al-Waili, Thia; Salom, Khelod

    2017-05-01

    Diabetic nephropathy is the major cause of end-stage renal disease and effective and new therapeutic approaches are needed in diabetic nephropathy and chronic kidney diseases. Oxidative stress and inflammatory process are important factors contributing to kidney damage by increasing production of oxidants. KEAP1/Nrf2/ARE pathway regulates the transcription of many antioxidant genes and modulation of the pathway up regulates antioxidants. NFB controls the expression of genes involved in the inflammatory response. Natural substances have antioxidant and anti-inflammatory activities and have an impact on NFB and KEAP1/Nrf2/ARE pathways. The preclinical studies explored the effectiveness of whole herbs, plants or seeds and their active ingredients in established diabetic nephropathy. They ameliorate oxidative stress induced kidney damage, enhance antioxidant system, and decrease inflammatory process and fibrosis; most likely by activating KEAP1/Nrf2/ARE pathway and by deactivating NFB pathway. Whole natural products contain balanced antioxidants that might work synergistically to induce beneficial therapeutic outcome. In this context, more clinical studies involving whole plants or herbal products or mixtures of different herbs and plants and their active ingredients might change our strategies for the management of diabetic nephropathy. The natural products might be useful as preventive interventions and studies are required in this field.

  3. Assessing the dietary bioavailability of metals associated with natural particles: Extending the use of the reverse labeling approach to zinc

    USGS Publications Warehouse

    Croteau, Marie-Noele; Cain, Daniel J.; Fuller, Christopher C.

    2017-01-01

    We extend the use of a novel tracing technique to quantify the bioavailability of zinc (Zn) associated with natural particles using snails enriched with a less common Zn stable isotope. Lymnaea stagnalis is a model species that has relatively fast Zn uptake rates from the dissolved phase, enabling their rapid enrichment in 67Zn during the initial phase of labeling. Isotopically enriched snails were subsequently exposed to algae mixed with increasing amounts of metal-rich particles collected from two acid mine drainage impacted rivers. Zinc bioavailability from the natural particles was inferred from calculations of 66Zn assimilation into the snail’s soft tissues. Zinc assimilation efficiency (AE) varied from 28% for the Animas River particles to 45% for the Snake River particles, indicating that particle-bound, or sorbed Zn, was bioavailable from acid mine drainage wastes. The relative binding strength of Zn sorption to the natural particles was inversely related to Zn bioavailability; a finding that would not have been possible without using the reverse labeling approach. Differences in the chemical composition of the particles suggest that their geochemical properties may influence the extent of Zn bioavailability.

  4. Aluminum as a source of background in low background experiments

    NASA Astrophysics Data System (ADS)

    Majorovits, B.; Abt, I.; Laubenstein, M.; Volynets, O.

    2011-08-01

    Neutrinoless double beta decay would be a key to understanding the nature of neutrino masses. The next generation of High Purity Germanium experiments will have to be operated with a background rate of better than 10 -5 counts/(kg y keV) in the region of interest around the Q-value of the decay. Therefore, so far irrelevant sources of background have to be considered. The metalization of the surface of germanium detectors is in general done with aluminum. The background from the decays of 22Na, 26Al, 226Ra and 228Th introduced by this metalization is discussed. It is shown that only a special selection of aluminum can keep these background contributions acceptable.

  5. Neurolinguistic Approach to Natural Language Processing with Applications to Medical Text Analysis

    PubMed Central

    Matykiewicz, Paweł; Pestian, John

    2008-01-01

    Understanding written or spoken language presumably involves spreading neural activation in the brain. This process may be approximated by spreading activation in semantic networks, providing enhanced representations that involve concepts that are not found directly in the text. Approximation of this process is of great practical and theoretical interest. Although activations of neural circuits involved in representation of words rapidly change in time snapshots of these activations spreading through associative networks may be captured in a vector model. Concepts of similar type activate larger clusters of neurons, priming areas in the left and right hemisphere. Analysis of recent brain imaging experiments shows the importance of the right hemisphere non-verbal clusterization. Medical ontologies enable development of a large-scale practical algorithm to re-create pathways of spreading neural activations. First concepts of specific semantic type are identified in the text, and then all related concepts of the same type are added to the text, providing expanded representations. To avoid rapid growth of the extended feature space after each step only the most useful features that increase document clusterization are retained. Short hospital discharge summaries are used to illustrate how this process works on a real, very noisy data. Expanded texts show significantly improved clustering and may be classified with much higher accuracy. Although better approximations to the spreading of neural activations may be devised a practical approach presented in this paper helps to discover pathways used by the brain to process specific concepts, and may be used in large-scale applications. PMID:18614334

  6. Heart Rate assessment by means of a novel approach applied to signals of different nature

    NASA Astrophysics Data System (ADS)

    Cosoli, G.; Casacanditella, L.; Tomasini, EP; Scalise, L.

    2017-01-01

    Electrocardiographic (ECG) signal presents many clinically relevant features (e.g. QT-interval, that is the duration of the ventricular depolarization). A novel processing technique has been demonstrated to be capable to measure some important characteristics according to the morphology of the waveform. Basing on that, the aim of this work is to propose an improved algorithm and to prove its efficacy in the assessment of the subject’s Heart Rate (HR) in comparison to standard algorithms (i.e. Pan & Tompkins). Results obtained in experimentally collected ECG signals for the identification of the main feature (R-peak) are comparable to those obtained with the traditional approach (sensitivity of 99.55% and 99.95%, respectively). Moreover, the use of this algorithm has been broaden to signals coming from different biomedical sensors (based on optical, acoustical and mechanical principles), all related to blood flow, for the computation of HR. In particular, it has been employed to PCG (Phonocardiography), PPG (Photoplethysmography) and VCG (Vibrocardiography), where standard algorithms could not be widely applied. HR results from a measurement campaign on 8 healthy subjects have shown, with respect to ECG, deviations (calculated as 2σ) of ±3.3 bpm, ±2.3 bpm and ±1.5 bpm for PCG, PPG and VCG, respectively. In conclusion, it is possible to state that the adopted algorithm is able to measure HR accurately from different biosignals. Future work will involve the extraction of additional morphological features in order to characterise the waveforms more deeply and to better describe the subject’s health status.

  7. Veterinary decision making in relation to metritis - a qualitative approach to understand the background for variation and bias in veterinary medical records

    PubMed Central

    Lastein, Dorte B; Vaarst, Mette; Enevoldsen, Carsten

    2009-01-01

    Background Results of analyses based on veterinary records of animal disease may be prone to variation and bias, because data collection for these registers relies on different observers in different settings as well as different treatment criteria. Understanding the human influence on data collection and the decisions related to this process may help veterinary and agricultural scientists motivate observers (veterinarians and farmers) to work more systematically, which may improve data quality. This study investigates qualitative relations between two types of records: 1) 'diagnostic data' as recordings of metritis scores and 2) 'intervention data' as recordings of medical treatment for metritis and the potential influence on quality of the data. Methods The study is based on observations in veterinary dairy practice combined with semi-structured research interviews of veterinarians working within a herd health concept where metritis diagnosis was described in detail. The observations and interviews were analysed by qualitative research methods to describe differences in the veterinarians' perceptions of metritis diagnosis (scores) and their own decisions related to diagnosis, treatment, and recording. Results The analysis demonstrates how data quality can be affected during the diagnostic procedures, as interaction occurs between diagnostics and decisions about medical treatments. Important findings were when scores lacked consistency within and between observers (variation) and when scores were adjusted to the treatment decision already made by the veterinarian (bias). The study further demonstrates that veterinarians made their decisions at 3 different levels of focus (cow, farm, population). Data quality was influenced by the veterinarians' perceptions of collection procedures, decision making and their different motivations to collect data systematically. Conclusion Both variation and bias were introduced into the data because of veterinarians' different

  8. Generative electronic background music system

    SciTech Connect

    Mazurowski, Lukasz

    2015-03-10

    In this short paper-extended abstract the new approach to generation of electronic background music has been presented. The Generative Electronic Background Music System (GEBMS) has been located between other related approaches within the musical algorithm positioning framework proposed by Woller et al. The music composition process is performed by a number of mini-models parameterized by further described properties. The mini-models generate fragments of musical patterns used in output composition. Musical pattern and output generation are controlled by container for the mini-models - a host-model. General mechanism has been presented including the example of the synthesized output compositions.

  9. Systems biology approach to developing S(2)RM-based "systems therapeutics" and naturally induced pluripotent stem cells.

    PubMed

    Maguire, Greg; Friedman, Peter

    2015-05-26

    The degree to, and the mechanisms through, which stem cells are able to build, maintain, and heal the body have only recently begun to be understood. Much of the stem cell's power resides in the release of a multitude of molecules, called stem cell released molecules (SRM). A fundamentally new type of therapeutic, namely "systems therapeutic", can be realized by reverse engineering the mechanisms of the SRM processes. Recent data demonstrates that the composition of the SRM is different for each type of stem cell, as well as for different states of each cell type. Although systems biology has been successfully used to analyze multiple pathways, the approach is often used to develop a small molecule interacting at only one pathway in the system. A new model is emerging in biology where systems biology is used to develop a new technology acting at multiple pathways called "systems therapeutics". A natural set of healing pathways in the human that uses SRM is instructive and of practical use in developing systems therapeutics. Endogenous SRM processes in the human body use a combination of SRM from two or more stem cell types, designated as S(2)RM, doing so under various state dependent conditions for each cell type. Here we describe our approach in using state-dependent SRM from two or more stem cell types, S(2)RM technology, to develop a new class of therapeutics called "systems therapeutics." Given the ubiquitous and powerful nature of innate S(2)RM-based healing in the human body, this "systems therapeutic" approach using S(2)RM technology will be important for the development of anti-cancer therapeutics, antimicrobials, wound care products and procedures, and a number of other therapeutics for many indications.

  10. The midlatitude North American background aerosol and global aerosol variation.

    PubMed

    Hidy, George M; Blanchard, Charles L

    2005-11-01

    Protocols for the particulate matter (PM) National Ambient Air Quality Standards (NAAQS), and the Regional Haze Rule (RHR) give two complementary definitions for "natural" background airborne particle concentrations in the United States. The definition for the NAAQS derives largely from reported annual averages, whereas the definition for the RHR takes into account the frequency of occurrence of a range of visibility conditions estimated using fine particle composition. These definitions are simple, static representations of background or "unmanageable" aerosol conditions in the United States. An accumulation of data from rural-remote sites representing global conditions indicates that the airborne particle concentrations are highly variable. Observational campaigns show weather-related variations, including incidents of regional or intercontinental transport of pollution that influence background aerosol levels over midlatitude North America. Defining a background in North America based on long-term observations relies mainly on the remote-rural IMPROVE network in the United States, with a few additional measurements from Canada. Examination of the frequency of occurrence of mass concentrations and particle components provides insight not only about annual median conditions but also the variability of apparent background conditions. The results of this analysis suggest that a more elaborate approach to defining an unmanageable background could improve the present approach taken for information input into the U.S. regulatory process. An approach interpreting the continental gradients in fine PM (PM2.5) concentrations and composition may be warranted.

  11. Map Your Hazards! - an Interdisciplinary, Place-Based Educational Approach to Assessing Natural Hazards, Social Vulnerability, Risk and Risk Perception.

    NASA Astrophysics Data System (ADS)

    Brand, B. D.; McMullin-Messier, P. A.; Schlegel, M. E.

    2014-12-01

    'Map your Hazards' is an educational module developed within the NSF Interdisciplinary Teaching about Earth for a Sustainable Future program (InTeGrate). The module engages students in place-based explorations of natural hazards, social vulnerability, and the perception of natural hazards and risk. Students integrate geoscience and social science methodologies to (1) identify and assess hazards, vulnerability and risk within their communities; (2) distribute, collect and evaluate survey data (designed by authors) on the knowledge, risk perception and preparedness within their social networks; and (3) deliver a PPT presentation to local stakeholders detailing their findings and recommendations for development of a prepared, resilient community. 'Map your Hazards' underwent four rigorous assessments by a team of geoscience educators and external review before being piloted in our classrooms. The module was piloted in a 300-level 'Volcanoes and Society' course at Boise State University, a 300-level 'Environmental Sociology' course at Central Washington University, and a 100-level 'Natural Disasters and Environmental Geology' course at the College of Western Idaho. In all courses students reported a fascination with learning about the hazards around them and identifying the high risk areas in their communities. They were also surprised at the low level of knowledge, inaccurate risk perception and lack of preparedness of their social networks. This successful approach to engaging students in an interdisciplinary, place-based learning environment also has the broad implications of raising awareness of natural hazards (survey participants are provided links to local hazard and preparedness information). The data and preparedness suggestions can be shared with local emergency managers, who are encouraged to attend the student's final presentations. All module materials are published at serc.carleton.edu/integrate/ and are appropriate to a wide range of classrooms.

  12. Biochemometrics for Natural Products Research: Comparison of Data Analysis Approaches and Application to Identification of Bioactive Compounds

    PubMed Central

    Kellogg, Joshua J.; Todd, Daniel A.; Egan, Joseph M.; Raja, Huzefa A.; Oberlies, Nicholas H.; Kvalheim, Olav M.; Cech, Nadja B.

    2016-01-01

    A central challenge of natural products research is assigning bioactive compounds from complex mixtures. The gold standard approach to address this challenge, bioassay-guided fractionation, is often biased towards abundant, rather than bioactive, mixture components. This study evaluated the combination of bioassay-guided fractionation with untargeted metabolite profiling to improve active component identification early in the fractionation process. Key to this methodology was statistical modeling of the integrated biological and chemical datasets (biochemometric analysis). Three data analysis approaches for biochemometric analysis were compared, namely, partial least squares loading vectors, S-plots, and the selectivity ratio. Extracts from the endophytic fungi Alternaria sp. and Pyrenochaeta sp. with antimicrobial activity against Staphylococcus aureus served as test cases. Biochemometric analysis incorporating the selectivity ratio performed best in identifying bioactive ions from these extracts early in the fractionation process, yielding altersetin (3, MIC 0.23 μg/mL) and macrosphelide A (4, MIC 75 μg/mL) as antibacterial constituents from Alternaria sp. and Pyrenochaeta sp., respectively. This study demonstrates the potential of biochemometrics coupled with bioassay-guided fractionation to identify bioactive mixture components. A benefit of this approach is the ability to integrate multiple stages of fractionation and bioassay data into a single analysis. PMID:26841051

  13. A sequential extraction and hydrolysis approach to understand the chemical nature of soil water repellency

    NASA Astrophysics Data System (ADS)

    Mao, Jiefei; Dekker, Stefan C.; Nierop, Klaas G. J.

    2014-05-01

    -hydroxy fatty acids and α,ω-dicarboxylic acids. Aside from fatty acids and alcohols, the latter two compound groups were considered as the main groups of monomers released from suberins. Therefore, suberin-derived compounds were most abundant in the AI fractions suggesting that plant roots could be the main source of AI fractions. We will present some of the relations between fractions/compounds and SWR to show that this approach may be an effective tool to improve our understanding of SWR mechanisms. We present relations between fractions/compounds from SOM with SWR to determine SWR-biomarkers. By assessing the origin of these biomarkers, we are able to understand how SWR is formed and in which circumstances they are mainly from leaves or roots (i.e. cutin or suberin). References: Doerr, S.H., Shakesby, R.A., Walsh, R.P.D., 2000. Soil water repellency: its causes, characteristics and hydro- geomorphological significance. Earth-Sci. Rev. 51, 33-65. Nierop, K.G.J., 1998. Origin of aliphatic compounds in a forest soil. Organic Geochemistry 29, 1009-1016.

  14. Discrimination between induced, triggered, and natural earthquakes close to hydrocarbon reservoirs: A probabilistic approach based on the modeling of depletion-induced stress changes and seismological source parameters

    NASA Astrophysics Data System (ADS)

    Dahm, Torsten; Cesca, Simone; Hainzl, Sebastian; Braun, Thomas; Krüger, Frank

    2015-04-01

    Earthquakes occurring close to hydrocarbon fields under production are often under critical view of being induced or triggered. However, clear and testable rules to discriminate the different events have rarely been developed and tested. The unresolved scientific problem may lead to lengthy public disputes with unpredictable impact on the local acceptance of the exploitation and field operations. We propose a quantitative approach to discriminate induced, triggered, and natural earthquakes, which is based on testable input parameters. Maxima of occurrence probabilities are compared for the cases under question, and a single probability of being triggered or induced is reported. The uncertainties of earthquake location and other input parameters are considered in terms of the integration over probability density functions. The probability that events have been human triggered/induced is derived from the modeling of Coulomb stress changes and a rate and state-dependent seismicity model. In our case a 3-D boundary element method has been adapted for the nuclei of strain approach to estimate the stress changes outside the reservoir, which are related to pore pressure changes in the field formation. The predicted rate of natural earthquakes is either derived from the background seismicity or, in case of rare events, from an estimate of the tectonic stress rate. Instrumentally derived seismological information on the event location, source mechanism, and the size of the rupture plane is of advantage for the method. If the rupture plane has been estimated, the discrimination between induced or only triggered events is theoretically possible if probability functions are convolved with a rupture fault filter. We apply the approach to three recent main shock events: (1) the Mw 4.3 Ekofisk 2001, North Sea, earthquake close to the Ekofisk oil field; (2) the Mw 4.4 Rotenburg 2004, Northern Germany, earthquake in the vicinity of the Söhlingen gas field; and (3) the Mw 6

  15. Extragalactic Backgrounds after Planck

    NASA Astrophysics Data System (ADS)

    Dore, Olivier

    offers a direct probe of the relation between light and matter. We will also revisit long-standing questions such as the nature of the extragalactic gamma-ray background and the active galactic nuclei contribution to the CIB. The astrophysical implications of our program are quite unique and far-reaching. As such, this proposal is essential to NASA objectives. Cross-cutting among different frequencies, we will be able to analyze in a synergic way a huge amount of data from current NASA surveys and projects, and we will directly address three of the seven key questions identified in the Astro2010 report ``New Worlds, New Horizons in Astronomy and Astrophysics'' : What is the fossil record of galaxy assembly from the first stars to present?, What are the connections between dark and luminous matter? How do cosmic structures form and evolve?

  16. A novel approach for determination of fundamental physical transport processes in natural channel design restoration sites with river steering structures

    NASA Astrophysics Data System (ADS)

    Robinson, J.; Endreny, T. A.; Becker, J. F.; Kroll, C.

    2012-12-01

    River restoration projects in the United States are frequently proposed and constructed with the intention of improving water quality, yet relatively little evidence exists regarding the success of these efforts. Many projects use an approach known as natural channel design (NCD), and include river steering structures. Prior assessment of water quality improvements within NCD sites has involved hydrologic retention modeling using a non-reactive tracer, with the goal of separately identifying hyporheic and surface transient storage (STS). A comparative approach involving NCD and non-NCD sites used by the authors yielded mixed results: although physically-based assessments of STS profiles in many NCD sites support larger STS zones than non-NCD sites, these differences are not apparent when examining common transient storage metrics. Inverse modeling within nine NCD sites reveals additional obstacles, including generation of spurious lateral inflow/outflow values, limited detection of hyporheic processes due to strong surface transient storage, shear and Taylor dispersion, and divergent temporal patterns of solute flux over channel cross sections bounding structures. To overcome the obstacles encountered with 1D inverse modeling, data is presented from a new approach used in NCD reaches. This approach involves deriving a mass flux signature via pairing velocity and channel geometry with multiple electrical conductivity (EC) loggers deployed laterally at control cross sections (CCS). These CCS bound sub-reach segments (15 total across four NCD reaches) that include river steering structures and intermediate geomorphic features. Velocity and geometry measurements yield discharge values surrounding each EC logger which are used to weight a composite mass flux breakthrough curve above, within, and below each segment. Composite mass flux signatures reflect exchange processes that are not fully integrated laterally immediately below structures, and can be analyzed via

  17. Nature-inspired computing approach for solving non-linear singular Emden-Fowler problem arising in electromagnetic theory

    NASA Astrophysics Data System (ADS)

    Khan, Junaid Ali; Zahoor Raja, Muhammad Asif; Rashidi, Mohammad Mehdi; Syam, Muhammad Ibrahim; Majid Wazwaz, Abdul

    2015-10-01

    In this research, the well-known non-linear Lane-Emden-Fowler (LEF) equations are approximated by developing a nature-inspired stochastic computational intelligence algorithm. A trial solution of the model is formulated as an artificial feed-forward neural network model containing unknown adjustable parameters. From the LEF equation and its initial conditions, an energy function is constructed that is used in the algorithm for the optimisation of the networks in an unsupervised way. The proposed scheme is tested successfully by applying it on various test cases of initial value problems of LEF equations. The reliability and effectiveness of the scheme are validated through comprehensive statistical analysis. The obtained numerical results are in a good agreement with their corresponding exact solutions, which confirms the enhancement made by the proposed approach.

  18. Novel targeted approach to better understand how natural structural barriers govern carotenoid in vitro bioaccessibility in vegetable-based systems.

    PubMed

    Palmero, Paola; Lemmens, Lien; Ribas-Agustí, Albert; Sosa, Carola; Met, Kristof; de Dieu Umutoni, Jean; Hendrickx, Marc; Van Loey, Ann

    2013-12-01

    An experimental approach, allowing us to understand the effect of natural structural barriers (cell walls, chromoplast substructures) on carotenoid bioaccessibility, was developed. Different fractions with different levels of carotenoid bio-encapsulation (carotenoid-enriched oil, chromoplasts, small cell clusters, and large cell clusters) were isolated from different types of carrots and tomatoes. An in vitro method was used to determine carotenoid bioaccessibility. In the present work, a significant decrease in carotenoid in vitro bioaccessibility could be observed with an increasing level of bio-encapsulation. Differences in cell wall material and chromoplast substructure between matrices influenced carotenoid release and inclusion in micelles. For carrots, cell walls and chromoplast substructure were important barriers for carotenoid bioaccessibility while, in tomatoes, the chromoplast substructure represented the most important barrier governing bioaccessibility. The highest increase in carotenoid bioaccessibility, for all matrices, was obtained after transferring carotenoids into the oil phase, a system lacking cell walls and chromoplast substructures that could hamper carotenoid release.

  19. Simple quantitative PCR approach to reveal naturally occurring and mutation-induced repetitive sequence variation on the Drosophila Y chromosome.

    PubMed

    Aldrich, John C; Maggert, Keith A

    2014-01-01

    Heterochromatin is a significant component of the human genome and the genomes of most model organisms. Although heterochromatin is thought to be largely non-coding, it is clear that it plays an important role in chromosome structure and gene regulation. Despite a growing awareness of its functional significance, the repetitive sequences underlying some heterochromatin remain relatively uncharacterized. We have developed a real-time quantitative PCR-based method for quantifying simple repetitive satellite sequences and have used this technique to characterize the heterochromatic Y chromosome of Drosophila melanogaster. In this report, we validate the approach, identify previously unknown satellite sequence copy number polymorphisms in Y chromosomes from different geographic sources, and show that a defect in heterochromatin formation can induce similar copy number polymorphisms in a laboratory strain. These findings provide a simple method to investigate the dynamic nature of repetitive sequences and characterize conditions which might give rise to long-lasting alterations in DNA sequence.

  20. Simple Quantitative PCR Approach to Reveal Naturally Occurring and Mutation-Induced Repetitive Sequence Variation on the Drosophila Y Chromosome

    PubMed Central

    Aldrich, John C.; Maggert, Keith A.

    2014-01-01

    Heterochromatin is a significant component of the human genome and the genomes of most model organisms. Although heterochromatin is thought to be largely non-coding, it is clear that it plays an important role in chromosome structure and gene regulation. Despite a growing awareness of its functional significance, the repetitive sequences underlying some heterochromatin remain relatively uncharacterized. We have developed a real-time quantitative PCR-based method for quantifying simple repetitive satellite sequences and have used this technique to characterize the heterochromatic Y chromosome of Drosophila melanogaster. In this report, we validate the approach, identify previously unknown satellite sequence copy number polymorphisms in Y chromosomes from different geographic sources, and show that a defect in heterochromatin formation can induce similar copy number polymorphisms in a laboratory strain. These findings provide a simple method to investigate the dynamic nature of repetitive sequences and characterize conditions which might give rise to long-lasting alterations in DNA sequence. PMID:25285439

  1. Assessing the pharmacokinetic profile of the CamMedNP natural products database: an in silico approach

    PubMed Central

    2013-01-01

    Background Drug metabolism and pharmacokinetic (DMPK) assessment has come to occupy a place of interest during the early stages of drug discovery today. Computer-based methods are slowly gaining ground in this area and are often used as initial tools to eliminate compounds likely to present uninteresting pharmacokinetic profiles and unacceptable levels of toxicity from the list of potential drug candidates, hence cutting down the cost of the discovery of a drug. Results In the present study, we present an in silico assessment of the DMPK profile of our recently published natural products database of 1,859 unique compounds derived from 224 species of medicinal plants from the Cameroonian forest. In this analysis, we have used 46 computed physico-chemical properties or molecular descriptors to predict the absorption, distribution, metabolism and elimination (ADME) of the compounds. This survey demonstrated that about 50% of the compounds within the Cameroonian medicinal plant and natural products (CamMedNP) database are compliant, having properties which fall within the range of ADME properties of >95% of currently known drugs, while >73% of the compounds have ≤2 violations. Moreover, about 72% of the compounds within the corresponding ‘drug-like’ subset showed compliance. Conclusions In addition to the previously verified levels of ‘drug-likeness’ and the diversity and the wide range of measured biological activities, the compounds in the CamMedNP database show interesting DMPK profiles and, hence, could represent an important starting point for hit/lead discovery from medicinal plants in Africa. PMID:24229455

  2. A portfolio approach to evaluating natural hazard mitigation policies: An Application to lateral-spread ground failure in Coastal California

    USGS Publications Warehouse

    Bernknopf, R.L.; Dinitz, L.B.; Rabinovici, S.J.M.; Evans, A.M.

    2001-01-01

    In the past, efforts to prevent catastrophic losses from natural hazards have largely been undertaken by individual property owners based on site-specific evaluations of risks to particular buildings. Public efforts to assess community vulnerability and encourage mitigation have focused on either aggregating site-specific estimates or adopting standards based upon broad assumptions about regional risks. This paper develops an alternative, intermediate-scale approach to regional risk assessment and the evaluation of community mitigation policies. Properties are grouped into types with similar land uses and levels of hazard, and hypothetical community mitigation strategies for protecting these properties are modeled like investment portfolios. The portfolios consist of investments in mitigation against the risk to a community posed by a specific natural hazard, and are defined by a community's mitigation budget and the proportion of the budget invested in locations of each type. The usefulness of this approach is demonstrated through an integrated assessment of earthquake-induced lateral-spread ground failure risk in the Watsonville, California area. Data from the magnitude 6.9 Loma Prieta earthquake of 1989 are used to model lateral-spread ground failure susceptibility. Earth science and economic data are combined and analyzed in a Geographic Information System (GIS). The portfolio model is then used to evaluate the benefits of mitigating the risk in different locations. Two mitigation policies, one that prioritizes mitigation by land use type and the other by hazard zone, are compared with a status quo policy of doing no further mitigation beyond that which already exists. The portfolio representing the hazard zone rule yields a higher expected return than the land use portfolio does: However, the hazard zone portfolio experiences a higher standard deviation. Therefore, neither portfolio is clearly preferred. The two mitigation policies both reduce expected losses

  3. Robust background modelling in DIALS

    PubMed Central

    Parkhurst, James M.; Winter, Graeme; Waterman, David G.; Fuentes-Montero, Luis; Gildea, Richard J.; Murshudov, Garib N.; Evans, Gwyndaf

    2016-01-01

    A method for estimating the background under each reflection during integration that is robust in the presence of pixel outliers is presented. The method uses a generalized linear model approach that is more appropriate for use with Poisson distributed data than traditional approaches to pixel outlier handling in integration programs. The algorithm is most applicable to data with a very low background level where assumptions of a normal distribution are no longer valid as an approximation to the Poisson distribution. It is shown that traditional methods can result in the systematic underestimation of background values. This then results in the reflection intensities being overestimated and gives rise to a change in the overall distribution of reflection intensities in a dataset such that too few weak reflections appear to be recorded. Statistical tests performed during data reduction may mistakenly attribute this to merohedral twinning in the crystal. Application of the robust generalized linear model algorithm is shown to correct for this bias. PMID:27980508

  4. Insuring Resilience - Employing Approaches from the Re/insurance Sector to Encourage Sustainable Design & Operations against Natural Hazards.

    NASA Astrophysics Data System (ADS)

    Douglas, R.

    2014-12-01

    Over the last quarter of a century the re/insuance sector and its financial regulators have developed a suite of metrics that have guided made a significant contribution to the industry's resilience to natural disasters. In particular the introduction of annual stress tests to evaluate risks to portfolios at 1:200, 1:20 and annual average loss metrics has provided a prism through which to focus science, engineeering and analytical actcities and the supporting data environment. This approach has driven a deeper understanding of the relationship between hazard, exposure and vulnerability of the build enviornment and helped put a quantitative value on physical and operational resilience. In particular has been the recognition that while structures and operations may be distrupted and disabled during a natural disaster or extreme event the critical issue is how quickly and cheaply functions can be reinstated after the event has passed. This has highlighted the value of enabling structures and institutional processes to close down, or even 'break' in a pre-planned way when forces are exceeded to prevent excessive dislocation and allow capabilities to reinstated in an planned and effective manner. New advances in financial regulation are making this increasingly attractive

  5. A 'Landscape physiology' approach for assessing bee health highlights the benefits of floral landscape enrichment and semi-natural habitats.

    PubMed

    Alaux, Cédric; Allier, Fabrice; Decourtye, Axel; Odoux, Jean-François; Tamic, Thierry; Chabirand, Mélanie; Delestra, Estelle; Decugis, Florent; Le Conte, Yves; Henry, Mickaël

    2017-01-13

    Understanding how anthropogenic landscape alteration affects populations of ecologically- and economically-important insect pollinators has never been more pressing. In this context, the assessment of landscape quality typically relies on spatial distribution studies, but, whether habitat-restoration techniques actually improve the health of targeted pollinator populations remains obscure. This gap could be filled by a comprehensive understanding of how gradients of landscape quality influence pollinator physiology. We therefore used this approach for honey bees (Apis mellifera) to test whether landscape patterns can shape bee health. We focused on the pre-wintering period since abnormally high winter colony losses have often been observed. By exposing colonies to different landscapes, enriched in melliferous catch crops and surrounded by semi-natural habitats, we found that bee physiology (i.e. fat body mass and level of vitellogenin) was significantly improved by the presence of flowering catch crops. Catch crop presence was associated with a significant increase in pollen diet diversity. The influence of semi-natural habitats on bee health was even stronger. Vitellogenin level was in turn significantly linked to higher overwintering survival. Therefore, our experimental study, combining landscape ecology and bee physiology, offers an exciting proof-of-concept for directly identifying stressful or suitable landscapes and promoting efficient pollinator conservation.

  6. A novel geotechnical/geostatistical approach for exploration and production of natural gas from multiple geologic strata, Phase 1

    SciTech Connect

    Overbey, W.K. Jr.; Reeves, T.K.; Salamy, S.P.; Locke, C.D.; Johnson, H.R.; Brunk, R.; Hawkins, L. )

    1991-05-01

    This research program has been designed to develop and verify a unique geostatistical approach for finding natural gas resources. The research has been conducted by Beckley College, Inc. (Beckley) and BDM Engineering Services Company (BDMESC) under contract to the US Department of Energy (DOE), Morgantown Energy Technology Center. Phase 1 of the project consisted of compiling and analyzing relevant geological and gas production information in selected areas of Raleigh County, West Virginia, ultimately narrowed to the Eccles, West Virginia, 7 {1/2} minute Quadrangle. The Phase 1 analysis identified key parameters contributing to the accumulation and production of natural gas in Raleigh County, developed analog models relating geological factors to gas production, and identified specific sites to test and verify the analysis methodologies by drilling. Based on the Phase 1 analysis, five sites have been identified with high potential for economic gas production. Phase 2 will consist of drilling, completing, and producing one or more wells at the sites identified in the Phase 1 analyses. The initial well is schedules to the drilled in April 1991. This report summarizes the results of the Phase 1 investigations. For clarity, the report has been prepared in two volumes. Volume 1 presents the Phase 1 overview; Volume 2 contains the detailed geological and production information collected and analyzed for this study.

  7. The Dramaturgy Approach to Education in Nature: Reflections of a Decade of International Vacation School Lipnice Courses, Czech Republic, 1997-2007

    ERIC Educational Resources Information Center

    Martin, Andrew J.

    2011-01-01

    This paper provides an auto-ethnography or narrative of self related to the development of international experiential education programmes in nature developed by Vacation School Lipnice (VSL) in the Czech Republic. The paper provides the cultural background that influences the course design and provides examples, through participant observation,…

  8. New approach for natural products screening by real-time monitoring of hemoglobin hydrolysis using quartz crystal microbalance.

    PubMed

    Cornelio, Vivian E; Pedroso, Mariele M; Afonso, André S; Fernandes, João B; da Silva, M Fátima G F; Faria, Ronaldo C; Vieira, Paulo C

    2015-03-03

    The hemoglobin (Hb) released from erythrocytes is a primary nutritive component for many blood-feeding parasites. The aspartic protease cathepsin D is a hemoglobinase that is involved in the Hb degradation process and is considered an interesting target for chemotherapy intervention. However, traditional enzymatic assays for studying Hb degradation utilize spectrophotometric techniques, which do not allow real-time monitoring and can present serious interference problems. Herein, we describe a biosensor using simple approach for the real-time monitoring of Hb hydrolysis as well as an efficient screening method for natural products as enzymatic inhibitors using a quartz crystal microbalance (QCM) technique. Hemoglobin was anchored on the quartz crystal surface using mixed self-assembled monolayers. The addition of the enzyme caused a mass change (frequency shift) due to Hb hydrolysis, which was monitored in real time. From the frequency change patterns of the Hb-functionalized QCM, we evaluated the enzymatic reaction by determining the kinetic parameters of product formation (k(cat)). The QCM enzymatic assay using immobilized human Hb was shown to be an excellent approach for screening possible inhibitors in complex mixtures, opening up a new avenue for the discovery of novel inhibitors.

  9. Mediating the potent ROS toxicity of acrolein in neurons with silica nanoparticles and a natural product approach

    NASA Astrophysics Data System (ADS)

    White-Schenk, Désirée.; Shi, Riyi; Leary, James F.

    2014-03-01

    Acrolein, a very reactive aldehyde, is a culprit in the biochemical cascade after primary, mechanical spinal cord injury (SCI), which leads to the destruction of tissue initially unharmed, referred to as "secondary injury". Additionally, in models of multiple sclerosis (MS) and some clinical research, acrolein levels are significantly increased. Due to its ability to make more copies of itself in the presence of tissue via lipid peroxidation, researchers believe that acrolein plays a role in the increased destruction of the central nervous system in both SCI and MS. Hydralazine, an FDAapproved hypotensive drug, has been shown to scavenge acrolein, but its side effects and short half life at the appropriate dose for acrolein scavenging must be improved for beneficial clinical translation. Therefore, a nanomedical approach has been designed using silica nanoparticles as a porous delivery vehicle hydralazine. The silica particles are formed in a one-step method that incorporates poly(ethylene) glycol (PEG), a stealth molecule, directly onto the nanoparticles. As an additional avenue for study, a natural product in green tea, epigallocatechin gallate (EGCG), has been explored for its ability to react with acrolein, disabling its reactive capabilities. Upon demonstration of attenuating acrolein, EGCG's delivery may also be improved using the nanomedical approach. The current work exposes the potential of using silica nanoparticles as a delivery vehicle and EGCG's antioxidant capabilities in B35 neuroblastoma cells exposed to acrolein. We also measure nanotoxicity to individual rat neurons using high-throughput image scanning cytometry.

  10. A continuous-discrete approach for evaluation of natural frequencies and mode shapes of high-rise buildings

    NASA Astrophysics Data System (ADS)

    Malekinejad, Mohsen; Rahgozar, Reza; Malekinejad, Ali; Rahgozar, Peyman

    2016-09-01

    In this paper, a continuous-discrete approach based on the concept of lumped mass and equivalent continuous approach is proposed for free vibration analysis of combined system of framed tube, shear core and outrigger-belt truss in high-rise buildings. This system is treated as a continuous system (i.e., discrete beams and columns are replaced with equivalent continuous membranes) and a discrete system (or lumped mass system) at different stages of dynamic analysis. The structure is discretized at each floor of the building as a series of lumped masses placed at the center of shear core. Each mass has two transitional degrees of freedom (lateral and axial( and one rotational. The effect of shear core and outrigger-belt truss on framed tube system is modeled as a rotational spring placed at the location of outrigger-belt truss system along structure's height. By solving the resulting eigen problem, natural frequencies and mode-shapes are obtained. Numerical examples are presented to show acceptable accuracy of the procedure in estimating the fundamental frequencies and corresponding mode shapes of the combined system as compared to finite element analysis of the complete structure. The simplified proposed method is much faster and should be more suitable for rapid interactive design.

  11. Background sources at PEP

    SciTech Connect

    Lynch, H.; Schwitters, R.F.; Toner, W.T.

    1988-01-01

    Important sources of background for PEP experiments are studied. Background particles originate from high-energy electrons and positrons which have been lost from stable orbits, ..gamma..-rays emitted by the primary beams through bremsstrahlung in the residual gas, and synchrotron radiation x-rays. The effect of these processes on the beam lifetime are calculated and estimates of background rates at the interaction region are given. Recommendations for the PEP design, aimed at minimizing background are presented. 7 figs., 4 tabs.

  12. Natural approaches to epilepsy.

    PubMed

    Gaby, Alan R

    2007-03-01

    This article reviews research on the use of diet, nutritional supplements, and hormones in the treatment of epilepsy. Potentially beneficial dietary interventions include identifying and treating blood glucose dysregulation, identifying and avoiding allergenic foods, and avoiding suspected triggering agents such as alcohol, aspartame, and monosodium glutamate. The ketogenic diet may be considered for severe, treatment-resistant cases. The Atkins diet (very low in carbohydrates) is a less restrictive type of ketogenic diet that may be effective in some cases. Nutrients that may reduce seizure frequency include vitamin B6, magnesium, vitamin E, manganese, taurine, dimethylglycine, and omega-3 fatty acids. Administration of thiamine may improve cognitive function in patients with epilepsy. Supplementation with folic acid, vitamin B6, biotin, vitamin D, and L-carnitine may be needed to prevent or treat deficiencies resulting from the use of anticonvulsant drugs. Vitamin K1 has been recommended near the end of pregnancy for women taking anticonvulsants. Melatonin may reduce seizure frequency in some cases, and progesterone may be useful for women with cyclic exacerbations of seizures. In most cases, nutritional therapy is not a substitute for anticonvulsant medications. However, in selected cases, depending on the effectiveness of the interventions, dosage reductions or discontinuation of medications may be possible.

  13. Building HIA approaches into strategies for green space use: an example from Plymouth's (UK) Stepping Stones to Nature project.

    PubMed

    Richardson, J; Goss, Z; Pratt, A; Sharman, J; Tighe, M

    2013-12-01

    The health and well-being benefits of access to green space are well documented. Research suggests positive findings regardless of social group, however barriers exist that limit access to green space, including proximity, geography and differing social conditions. Current public health policy aims to broaden the range of environmental public health interventions through effective partnership working, providing opportunities to work across agencies to promote the use of green space. Health Impact Assessment (HIA) is a combination of methods and procedures to assess the potential health and well-being impacts of policies, developments and projects. It provides a means by which negative impacts can be mitigated and positive impacts can be enhanced, and has potential application for assessing green space use. This paper describes the application of a HIA approach to a multi-agency project (Stepping Stones to Nature--SS2N) in the UK designed to improve local green spaces and facilitate green space use in areas classified as having high levels of deprivation. The findings suggest that the SS2N project had the potential to provide significant positive benefits in the areas of physical activity, mental and social well-being. Specific findings for one locality identified a range of actions that could be taken to enhance benefits, and mitigate negative factors such as anti-social behaviour. The HIA approach proved to be a valuable process through which impacts of a community development/public health project could be enhanced and negative impacts prevented at an early stage; it illustrates how a HIA approach could enhance multi-agency working to promote health and well-being in communities.

  14. The Effectiveness of the Conceptual Change Approach, Explicit Reflective Approach, and Course Book by the Ministry of Education on the Views of the Nature of Science and Conceptual Change in Light Unit

    ERIC Educational Resources Information Center

    Cil, Emine; Cepni, Salih

    2012-01-01

    The aim of this study was to analyze the effectiveness of the conceptual change approach, explicit reflective approach, and the course book by the Ministry of Education on the views toward the nature of science and conceptual change in the Light unit. Three study groups were selected from several seventh grade classes. Two of the three classes,…

  15. Lipid Replacement Therapy: a natural medicine approach to replacing damaged lipids in cellular membranes and organelles and restoring function.

    PubMed

    Nicolson, Garth L; Ash, Michael E

    2014-06-01

    Lipid Replacement Therapy, the use of functional oral supplements containing cell membrane phospholipids and antioxidants, has been used to replace damaged, usually oxidized, membrane glycerophospholipids that accumulate during aging and in various clinical conditions in order to restore cellular function. This approach differs from other dietary and intravenous phospholipid interventions in the composition of phospholipids and their defense against oxidation during storage, ingestion, digestion and uptake as well as the use of protective molecules that noncovalently complex with phospholipid micelles and prevent their enzymatic and bile disruption. Once the phospholipids have been taken in by transport processes, they are protected by several natural mechanisms involving lipid receptors, transport and carrier molecules and circulating cells and lipoproteins until their delivery to tissues and cells where they can again be transferred to intracellular membranes by specific and nonspecific transport systems. Once delivered to membrane sites, they naturally replace and stimulate removal of damaged membrane lipids. Various chronic clinical conditions are characterized by membrane damage, mainly oxidative but also enzymatic, resulting in loss of cellular function. This is readily apparent in mitochondrial inner membranes where oxidative damage to phospholipids like cardiolipin and other molecules results in loss of trans-membrane potential, electron transport function and generation of high-energy molecules. Recent clinical trials have shown the benefits of Lipid Replacement Therapy in restoring mitochondrial function and reducing fatigue in aged subjects and patients with a variety of clinical diagnoses that are characterized by loss of mitochondrial function and include fatigue as a major symptom. This Article is Part of a Special Issue Entitled: Membrane Structure and Function: Relevance in the Cell's Physiology, Pathology and Therapy.

  16. Efficient and accurate local approximations to coupled-electron pair approaches: An attempt to revive the pair natural orbital method

    NASA Astrophysics Data System (ADS)

    Neese, Frank; Wennmohs, Frank; Hansen, Andreas

    2009-03-01

    Coupled-electron pair approximations (CEPAs) and coupled-pair functionals (CPFs) have been popular in the 1970s and 1980s and have yielded excellent results for small molecules. Recently, interest in CEPA and CPF methods has been renewed. It has been shown that these methods lead to competitive thermochemical, kinetic, and structural predictions. They greatly surpass second order Møller-Plesset and popular density functional theory based approaches in accuracy and are intermediate in quality between CCSD and CCSD(T) in extended benchmark studies. In this work an efficient production level implementation of the closed shell CEPA and CPF methods is reported that can be applied to medium sized molecules in the range of 50-100 atoms and up to about 2000 basis functions. The internal space is spanned by localized internal orbitals. The external space is greatly compressed through the method of pair natural orbitals (PNOs) that was also introduced by the pioneers of the CEPA approaches. Our implementation also makes extended use of density fitting (or resolution of the identity) techniques in order to speed up the laborious integral transformations. The method is called local pair natural orbital CEPA (LPNO-CEPA) (LPNO-CPF). The implementation is centered around the concepts of electron pairs and matrix operations. Altogether three cutoff parameters are introduced that control the size of the significant pair list, the average number of PNOs per electron pair, and the number of contributing basis functions per PNO. With the conservatively chosen default values of these thresholds, the method recovers about 99.8% of the canonical correlation energy. This translates to absolute deviations from the canonical result of only a few kcal mol-1. Extended numerical test calculations demonstrate that LPNO-CEPA (LPNO-CPF) has essentially the same accuracy as parent CEPA (CPF) methods for thermochemistry, kinetics, weak interactions, and potential energy surfaces but is up to 500

  17. The Cosmic Background Explorer.

    ERIC Educational Resources Information Center

    Gulkis, Samuel; And Others

    1990-01-01

    Outlines the Cosmic Background Explorer (COBE) mission to measure celestial radiation. Describes the instruments used and experiments involving differential microwave radiometers, and a far infrared absolute spectrophotometer. (YP)

  18. Upstream-independent ribosomal RNA amplification analysis (URA): a new approach to characterizing the diversity of natural microbial communities.

    PubMed

    Yakimov, M M; Giuliano, L; Timmis, K N; Golyshin, P N

    2001-10-01

    Here, we propose an advanced method for recently developed fingerprinting strategies to analyse microbial populations by direct detection of 16S rRNA sequences occurring in natural habitats. The differential display (DD) technique, which is widely used to analyse for eukaryotic gene expression, was optimized to assess bacterial rRNA diversity in environmental samples. Double-stranded cDNAs of rRNAs were synthesized without a forward primer digested with endonuclease and ligated with a double-stranded adapter. The fragments obtained were then amplified using an adapter-specific extended primer and a 16S rDNA universal reverse primer pair displayed by electrophoresis on a polyacrylamide gel. We validated this approach by characterization of a microbial community colonizing a geothermal (48 degrees C) vent system located close to the eruption zone of the south-east crater of the Mount Etna volcano, Sicily. Analysis of the patterns of abundant 16S rRNA revealed a considerable diversity of metabolically active bacteria phylogenetically clustering within the Crenarchaeota, Cyanobacteria, Firmicutes, Planctomycetales and Thermus divisions. Two sequence phylotypes were affiliated with uncultivated representatives of the recently described candidate division OP10 from a Yellowstone hot spring.

  19. Combining Mass Spectrometric Metabolic Profiling with Genomic Analysis: A Powerful Approach for Discovering Natural Products from Cyanobacteria.

    PubMed

    Kleigrewe, Karin; Almaliti, Jehad; Tian, Isaac Yuheng; Kinnel, Robin B; Korobeynikov, Anton; Monroe, Emily A; Duggan, Brendan M; Di Marzo, Vincenzo; Sherman, David H; Dorrestein, Pieter C; Gerwick, Lena; Gerwick, William H

    2015-07-24

    An innovative approach was developed for the discovery of new natural products by combining mass spectrometric metabolic profiling with genomic analysis and resulted in the discovery of the columbamides, a new class of di- and trichlorinated acyl amides with cannabinomimetic activity. Three species of cultured marine cyanobacteria, Moorea producens 3L, Moorea producens JHB, and Moorea bouillonii PNG, were subjected to genome sequencing and analysis for their recognizable biosynthetic pathways, and this information was then compared with their respective metabolomes as detected by MS profiling. By genome analysis, a presumed regulatory domain was identified upstream of several previously described biosynthetic gene clusters in two of these cyanobacteria, M. producens 3L and M. producens JHB. A similar regulatory domain was identified in the M. bouillonii PNG genome, and a corresponding downstream biosynthetic gene cluster was located and carefully analyzed. Subsequently, MS-based molecular networking identified a series of candidate products, and these were isolated and their structures rigorously established. On the basis of their distinctive acyl amide structure, the most prevalent metabolite was evaluated for cannabinomimetic properties and found to be moderate affinity ligands for CB1.

  20. Review on dry reforming of methane, a potentially more environmentally-friendly approach to the increasing natural gas exploitation

    PubMed Central

    Lavoie, Jean-Michel

    2014-01-01

    With the actual growth of the natural gas industry in the US as well as the potential and availability of this non-renewable carbon source worldwide, reforming of methane gas is getting increasing attention. Methane can be used for the production of heat or electricity, as well, it can be converted to syngas, a building block that could lead to the production of liquid fuels and chemicals, a very promising pathway in light of the increasing price of oil. Amongst the different reforming techniques, dry reforming could represent a very interesting approach both to valorize a cheap source or carbon (CO2) as well as to reduce the overall carbon footprint of the increasing worldwide fossil-based methane consumption. In this short review, attention will be given to the thermodynamics of dry reforming followed by an investigation on dry reforming using heterogeneous catalyst by focusing on the most popular elements used in literature for dry reforming. Attention will as well be given to other emerging techniques that may allow countering at one point the high thermodynamic penalties that accompanies conversion of methane using carbon dioxide. PMID:25426488

  1. Review on dry reforming of methane, a potentially more environmentally-friendly approach to the increasing natural gas exploitation.

    PubMed

    Lavoie, Jean-Michel

    2014-01-01

    With the actual growth of the natural gas industry in the US as well as the potential and availability of this non-renewable carbon source worldwide, reforming of methane gas is getting increasing attention. Methane can be used for the production of heat or electricity, as well, it can be converted to syngas, a building block that could lead to the production of liquid fuels and chemicals, a very promising pathway in light of the increasing price of oil. Amongst the different reforming techniques, dry reforming could represent a very interesting approach both to valorize a cheap source or carbon (CO2) as well as to reduce the overall carbon footprint of the increasing worldwide fossil-based methane consumption. In this short review, attention will be given to the thermodynamics of dry reforming followed by an investigation on dry reforming using heterogeneous catalyst by focusing on the most popular elements used in literature for dry reforming. Attention will as well be given to other emerging techniques that may allow countering at one point the high thermodynamic penalties that accompanies conversion of methane using carbon dioxide.

  2. Emphasizing the History of Genetics in an Explicit and Reflective Approach to Teaching the Nature of Science

    NASA Astrophysics Data System (ADS)

    Williams, Cody Tyler; Rudge, David Wÿss

    2016-05-01

    Science education researchers have long advocated the central role of the nature of science (NOS) for our understanding of scientific literacy. NOS is often interpreted narrowly to refer to a host of epistemological issues associated with the process of science and the limitations of scientific knowledge. Despite its importance, practitioners and researchers alike acknowledge that students have difficulty learning NOS and that this in part reflects how difficult it is to teach. One particularly promising method for teaching NOS involves an explicit and reflective approach using the history of science. The purpose of this study was to determine the influence of a historically based genetics unit on undergraduates' understanding of NOS. The three-class unit developed for this study introduces students to Mendelian genetics using the story of Gregor Mendel's work. NOS learning objectives were emphasized through discussion questions and investigations. The unit was administered to undergraduates in an introductory biology course for pre-service elementary teachers. The influence of the unit was determined by students' responses to the SUSSI instrument, which was administered pre- and post-intervention. In addition, semi-structured interviews were conducted that focused on changes in students' responses from pre- to post-test. Data collected indicated that students showed improved NOS understanding related to observations, inferences, and the influence of culture on science.

  3. Understanding the role of scientific evidence in consumer evaluation of natural health products for osteoarthritis an application of the means end chain approach

    PubMed Central

    2012-01-01

    Background Over 30% of individuals use natural health products (NHPs) for osteoarthritis-related pain. The Deficit Model for the Public Understanding of Science suggests that if individuals are given more information (especially about scientific evidence) they will make better health-related decisions. In contrast, the Contextual Model argues that scientific evidence is one of many factors that explain how consumers make health-related decisions. The primary objective was to investigate how the level of scientific evidence supporting the efficacy of NHPs impacts consumer decision-making in the self-selection of NHPs by individuals with osteoarthritis. Methods The means-end chain approach to product evaluation was used to compare laddering interviews with two groups of community-dwelling Canadian seniors who had used NHPs to treat their osteoarthritis. Group 1 (n=13) had used only NHPs (glucosamine and/or chondroitin) with “high” scientific evidence of efficacy. Group 2 (n=12) had used NHPs (methylsulfonylmethane (MSM) and/or bromelain) with little or no scientific evidence supporting efficacy. Content analysis and generation of hierarchical value maps facilitated the identification of similarities and differences between the two groups. Results The dominant decision-making chains for participants in the two scientific evidence categories were similar. Scientific evidence was an important decision-making factor but not as important as the advice from health care providers, friends and family. Most participants learned about scientific evidence via indirect sources from health care providers and the media. Conclusions The Contextual Model of the public understanding of science helps to explain why our participants believed scientific evidence is not the most important factor in their decision to use NHPs to help manage their osteoarthritis. PMID:23107559

  4. Correlators in nontrivial backgrounds

    SciTech Connect

    Mello Koch, Robert de; Ives, Norman; Stephanou, Michael

    2009-01-15

    Operators in N=4 super Yang-Mills theory with an R-charge of O(N{sup 2}) are dual to backgrounds which are asymtotically AdS{sub 5}xS{sup 5}. In this article we develop efficient techniques that allow the computation of correlation functions in these backgrounds. We find that (i) contractions between fields in the string words and fields in the operator creating the background are the field theory accounting of the new geometry, (ii) correlation functions of probes in these backgrounds are given by the free field theory contractions but with rescaled propagators and (iii) in these backgrounds there are no open string excitations with their special end point interactions; we have only closed string excitations.

  5. The Athena Background

    NASA Astrophysics Data System (ADS)

    Piro, Luigi; Lotti, Simone; Macculi, Claudio; Molendi, Silvano; Eraerds, Tanja; Laurent, Philippe

    2015-09-01

    Estimating, reducing and controlling the residual particle background is fundamental for achieving the objectives of several science topics of Athena, in particular those connected with background dominated observations of faint and/or diffuse sources. This requires assessing the particle environment in L2, propagating the various particle components throughout the mirror, spacecraft, and instruments via proper modelling and simulations of various physical processes, implementing design and h/w measures at instrument and mission level to reduce the un-rejected background and identifying proper calibration methods to control the background variations. Likewise, an adequate knowledge of the XRB, made of components that may vary spatially or temporally, is required as well. Here we will review the present status of the background knowledge, and summarize the activities on-going within Athena at various levels.

  6. The Environmental Protection Agency's Watershed-based Approach: where social and natural sciences meet to address today's water resource challenges

    NASA Astrophysics Data System (ADS)

    Biddle, J. C.

    2010-12-01

    A growing number of governmental organizations at the local, state, and federal level collaborate with nongovernmental organizations and individuals to solve watershed scale problems (Imperial and Koontz, 2007). Such a shift in policy approach from hierarchical regulation to bottom-up collaboration is largely a result of regulator’s recognition of the interdependence of natural and socio-economic systems on a watershed scale (Steelman and Carmin, 2002. Agencies throughout the federal government increasingly favored new governing institutions that encourage cooperation between local actors with conflicting interests, divergent geographic bases, and overlapping administrative jurisdictions to resolve continuing disputes over resource management (Bardach 1998). This favoritism of collaborative over command-and-control approaches for managing nonpoint source pollution led to the development of watershed partnerships and the watershed-based approach (Lubell et al., 2002). This study aims to further collaborative governance scholarship and aid decision-makers in identifying the critical elements of collaborative governance resulting in environmental improvements. To date, this relationship has not been empirically determined, in spite of the fact that collaborative governance is used routinely by the U.S. Environmental Protection Agency in resolving issues related to watershed management and other applications. This gap in the research is largely due to the lack of longitudinal data. In order to determine whether changes have occurred, environmental data must be collected over relatively long time periods (Koontz and Thomas, 2006; Sabatier, et al., 2005). However, collecting these data is often cost prohibitive. Monitoring water quality is expensive and requires technical expertise, and is often the first line item cut in environmental management budgets. This research is interdisciplinary, looking at the physical, chemical, and biological parameters for 44 waterbodies

  7. Text Mining and Natural Language Processing Approaches for Automatic Categorization of Lay Requests to Web-Based Expert Forums

    PubMed Central

    Reincke, Ulrich; Michelmann, Hans Wilhelm

    2009-01-01

    Background Both healthy and sick people increasingly use electronic media to obtain medical information and advice. For example, Internet users may send requests to Web-based expert forums, or so-called “ask the doctor” services. Objective To automatically classify lay requests to an Internet medical expert forum using a combination of different text-mining strategies. Methods We first manually classified a sample of 988 requests directed to a involuntary childlessness forum on the German website “Rund ums Baby” (“Everything about Babies”) into one or more of 38 categories belonging to two dimensions (“subject matter” and “expectations”). After creating start and synonym lists, we calculated the average Cramer’s V statistic for the association of each word with each category. We also used principle component analysis and singular value decomposition as further text-mining strategies. With these measures we trained regression models and determined, on the basis of best regression models, for any request the probability of belonging to each of the 38 different categories, with a cutoff of 50%. Recall and precision of a test sample were calculated as a measure of quality for the automatic classification. Results According to the manual classification of 988 documents, 102 (10%) documents fell into the category “in vitro fertilization (IVF),” 81 (8%) into the category “ovulation,” 79 (8%) into “cycle,” and 57 (6%) into “semen analysis.” These were the four most frequent categories in the subject matter dimension (consisting of 32 categories). The expectation dimension comprised six categories; we classified 533 documents (54%) as “general information” and 351 (36%) as a wish for “treatment recommendations.” The generation of indicator variables based on the chi-square analysis and Cramer’s V proved to be the best approach for automatic classification in about half of the categories. In combination with the two other

  8. A Multi-Level Approach to Modeling Rapidly Growing Mega-Regions as a Coupled Human-Natural System

    NASA Astrophysics Data System (ADS)

    Koch, J. A.; Tang, W.; Meentemeyer, R. K.

    2013-12-01

    The FUTure Urban-Regional Environment Simulation (FUTURES) integrates information on nonstationary drivers of land change (per capita land area demand, site suitability, and spatial structure of conversion events) into spatial-temporal projections of changes in landscape patterns (Meentemeyer et al., 2013). One striking feature of FUTURES is its patch-growth algorithm that includes feedback effects of former development events across several temporal and spatial scales: cell-level transition events are aggregated into patches of land change and their further growth is based on empirically derived parameters controlling its size, shape, and dispersion. Here, we augment the FUTURES modeling framework by expanding its multilevel structure and its representation of human decision making. The new modeling framework is hierarchically organized as nested subsystems including the latest theory on telecouplings in coupled human-natural systems (Liu et al., 2013). Each subsystem represents a specific level of spatial scale and embraces agents that have decision making authority at a particular level. The subsystems are characterized with regard to their spatial representation and are connected via flows of information (e.g. regulations and policies) or material (e.g. population migration). To provide a modeling framework that is applicable to a wide range of settings and geographical regions and to keep it computationally manageable, we implement a 'zooming factor' that allows to enable or disable subsystems (and hence the represented processes), based on the extent of the study region. The implementation of the FUTURES modeling framework for a specific case study follows the observational modeling approach described in Grimm et al. (2005), starting from the analysis of empirical data in order to capture the processes relevant for specific scales and to allow a rigorous calibration and validation of the model application. In this paper, we give an introduction to the basic

  9. The cosmic neutrino background

    NASA Technical Reports Server (NTRS)

    Dar, Arnon

    1991-01-01

    The cosmic neutrino background is expected to consist of relic neutrinos from the big bang, of neutrinos produced during nuclear burning in stars, of neutrinos released by gravitational stellar collapse, and of neutrinos produced by cosmic ray interactions with matter and radiation in the interstellar and intergalactic medium. Formation of baryonic dark matter in the early universe, matter-antimatter annihilation in a baryonic symmetric universe, and dark matter annihilation could have also contributed significantly to the cosmic neutrino background. The purpose of this paper is to review the properties of these cosmic neutrino backgrounds, the indirect evidence for their existence, and the prospects for their detection.

  10. Background Underground at WIPP

    NASA Astrophysics Data System (ADS)

    Esch, Ernst-Ingo; Hime, A.; Bowles, T. J.

    2001-04-01

    Recent interest to establish a dedicated underground laboratory in the United States prompted an experimental program at to quantify the enviromental backgrounds underground at the Waste Isolation Pilot Plant (WIPP) in Carlsbad, New Mexico. An outline of this program is provided along with recent experimental data on the cosmic ray muon flux at the 650 meter level of WIPP. The implications of the cosmic ray muon and fast neutron background at WIPP will be discussed in the context of new generation, low background experiments envisioned in the future.

  11. Fluctuations in the Cosmic Microwave Background

    NASA Astrophysics Data System (ADS)

    Zaldarriaga, Matias

    1998-06-01

    In this thesis we investigate several aspects related to the theory of fluctuations in the Cosmic Microwave Background. We develop a new algorithm to calculate the angular power spectrum of the anisotropies which is two orders of magnitude faster than the standard Boltzmann hierarchy approach (Chapter 3). The new algorithm will become essential when comparing the observational results of the next generation of CMB experiments with theoretical predictions. The parameter space of the models is so large that an exhaustive exploration to find the best fit model will only be feasible with this new type of algorithm. We also investigate the polarization properties of the CMB field. We develop a new formalism to describe the statistics of the polarization variables that takes into account their spin two nature (Chapter 2). In Chapter 4 we explore several physical effects that create distinct features in the polarization power spectrum. We study the signature of the reionization of the universe and a stochastic background of gravitational waves. We also describe how the polarization correlation functions can be used to test the causal structure of the universe. Finally in Chapter 5 we quantify the amount of information the next generation of satellites can obtain by measuring both temperature and polarization anisotropies. We calculate the expected error bars on the cosmological parameters for the specifications of the MAP and Planck satellite missions.

  12. Notification: Background Investigation Services

    EPA Pesticide Factsheets

    Project #OA-FY15-0029, February 26, 2015. The Office of Inspector General (OIG) for the U.S. Environmental Protection Agency (EPA) plans to begin field work for our audit of background investigation services.

  13. The GLAST Background Model

    SciTech Connect

    Ormes, J. F.; Atwood, W.; Burnett, T.; Grove, E.; Longo, F.; McEnery, J.; Ritz, S.; Mizuno, T.

    2007-07-12

    In order to estimate the ability of the GLAST/LAT to reject unwanted background of charged particles, optimize the on-board processing, size the required telemetry and optimize the GLAST orbit, we developed a detailed model of the background particles that would affect the LAT. In addition to the well-known components of the cosmic radiation, we included splash and reentrant components of protons, electrons (e+ and e-) from 10 MeV and beyond as well as the albedo gamma rays produced by cosmic ray interactions with the atmosphere. We made estimates of the irreducible background components produced by positrons and hadrons interacting in the multilayered micrometeorite shield and spacecraft surrounding the LAT and note that because the orbital debris has increased, the shielding required and hence the background are larger than were present in EGRET. Improvements to the model are currently being made to include the east-west effect.

  14. The GLAST Background Model

    SciTech Connect

    Ormes, J.F.; Atwood, W.; Burnett, T.; Grove, E.; Longo, F.; McEnery, J.; Mizuno, T.; Ritz, S.; /NASA, Goddard

    2007-10-17

    In order to estimate the ability of the GLAST/LAT to reject unwanted background of charged particles, optimize the on-board processing, size the required telemetry and optimize the GLAST orbit, we developed a detailed model of the background particles that would affect the LAT. In addition to the well-known components of the cosmic radiation, we included splash and reentrant components of protons, electrons (e+ and e-) from 10 MeV and beyond as well as the albedo gamma rays produced by cosmic ray interactions with the atmosphere. We made estimates of the irreducible background components produced by positrons and hadrons interacting in the multilayered micrometeorite shield and spacecraft surrounding the LAT and note that because the orbital debris has increased, the shielding required and hence the background are larger than were present in EGRET. Improvements to the model are currently being made to include the east-west effect.

  15. Solution-Focused Approaches in the Practice of UK Educational Psychologists: A Study of the Nature of Their Application and Evidence of Their Effectiveness

    ERIC Educational Resources Information Center

    Stobie, Ingeborg; Boyle, James; Woolfson, Lisa

    2005-01-01

    Solution-focused approaches are increasingly widely used in the practice of the applied educational psychologist (EP) (Ajmal and Rees, 2001; Durrant, 1993; Redpath and Harper, 1999; Rhodes and Ajmal, 1995). Based on a small-scale computer-mediated exploratory survey, this article examines the nature of such practice and investigates whether and…

  16. 23 CFR 777.3 - Background.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... NATURAL HABITAT § 777.3 Background. (a) Executive Order 11990 (42 FR 26961, 3 CFR, 1977 Comp., p. 121... natural habitats which result from projects funded pursuant to title 23, U.S. Code, as eligible for... consultation procedures relative to impacts to species listed under the authority of the Act and their...

  17. 23 CFR 777.3 - Background.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... NATURAL HABITAT § 777.3 Background. (a) Executive Order 11990 (42 FR 26961, 3 CFR, 1977 Comp., p. 121... natural habitats which result from projects funded pursuant to title 23, U.S. Code, as eligible for... consultation procedures relative to impacts to species listed under the authority of the Act and their...

  18. 23 CFR 777.3 - Background.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... NATURAL HABITAT § 777.3 Background. (a) Executive Order 11990 (42 FR 26961, 3 CFR, 1977 Comp., p. 121... natural habitats which result from projects funded pursuant to title 23, U.S. Code, as eligible for... consultation procedures relative to impacts to species listed under the authority of the Act and their...

  19. 23 CFR 777.3 - Background.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... NATURAL HABITAT § 777.3 Background. (a) Executive Order 11990 (42 FR 26961, 3 CFR, 1977 Comp., p. 121... natural habitats which result from projects funded pursuant to title 23, U.S. Code, as eligible for... consultation procedures relative to impacts to species listed under the authority of the Act and their...

  20. 23 CFR 777.3 - Background.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... NATURAL HABITAT § 777.3 Background. (a) Executive Order 11990 (42 FR 26961, 3 CFR, 1977 Comp., p. 121... natural habitats which result from projects funded pursuant to title 23, U.S. Code, as eligible for... consultation procedures relative to impacts to species listed under the authority of the Act and their...

  1. Oil & Natural Gas Technology A new approach to understanding the occurrence and volume of natural gas hydrate in the northern Gulf of Mexico using petroleum industry well logs

    SciTech Connect

    Cook, Ann; Majumdar, Urmi

    2016-03-31

    The northern Gulf of Mexico has been the target for the petroleum industry for exploration of conventional energy resource for decades. We have used the rich existing petroleum industry well logs to find the occurrences of natural gas hydrate in the northern Gulf of Mexico. We have identified 798 wells with well log data within the gas hydrate stability zone. Out of those 798 wells, we have found evidence of gas hydrate in well logs in 124 wells (15% of wells). We have built a dataset of gas hydrate providing information such as location, interval of hydrate occurrence (if any) and the overall quality of probable gas hydrate. Our dataset provides a wide, new perspective on the overall distribution of gas hydrate in the northern Gulf of Mexico and will be the key to future gas hydrate research and prospecting in the area.

  2. SPAM Detection Server Model Inspired by the Dionaea Muscipula Closure Mechanism: An Alternative Approach for Natural Computing Challenges

    NASA Astrophysics Data System (ADS)

    de Souza Pereira Lopes, Rodrigo Arthur; Carrari R. Lopes, Lia; Mustaro, Pollyana Notargiacomo

    Natural computing has been an increasingly evolving field in the last few years. Focusing on the interesting behaviours offered by nature and biological processes, this work intends to apply the metaphor of the carnivorous plant "Dionaea muscipula" as a complementary defence system against a recurring problem regarding internet and e-mails: spam. The metaphor model presents relevant aspects for further implementation and debate.

  3. From FRA to RFN: How the Family Resemblance Approach Can Be Transformed for Science Curriculum Analysis on Nature of Science

    NASA Astrophysics Data System (ADS)

    Kaya, Ebru; Erduran, Sibel

    2016-11-01

    The inclusion of Nature of Science (NOS) in the science curriculum has been advocated around the world for several decades. One way of defining NOS is related to the family resemblance approach (FRA). The family resemblance idea was originally described by Wittgenstein. Subsequently, philosophers and educators have applied Wittgenstein's idea to problems of their own disciplines. For example, Irzik and Nola adapted Wittgenstein's generic definition of the family resemblance idea to NOS, while Erduran and Dagher reconceptualized Irzik and Nola's FRA-to-NOS by synthesizing educational applications by drawing on perspectives from science education research. In this article, we use the terminology of "Reconceptualized FRA-to-NOS (RFN)" to refer to Erduran and Dagher's FRA version which offers an educational account inclusive of knowledge about pedagogical, instructional, curricular and assessment issues in science education. Our motivation for making this distinction is rooted in the need to clarify the various accounts of the family resemblance idea.The key components of the RFN include the aims and values of science, methods and methodological rules, scientific practices, scientific knowledge as well as the social-institutional dimensions of science including the social ethos, certification, and power relations. We investigate the potential of RFN in facilitating curriculum analysis and in determining the gaps related to NOS in the curriculum. We analyze two Turkish science curricula published 7 years apart and illustrate how RFN can contribute not only to the analysis of science curriculum itself but also to trends in science curriculum development. Furthermore, we present an analysis of documents from USA and Ireland and contrast them to the Turkish curricula thereby illustrating some trends in the coverage of RFN categories. The results indicate that while both Turkish curricula contain statements that identify science as a cognitive-epistemic system, they

  4. The Cosmic Background Explorer

    NASA Technical Reports Server (NTRS)

    Gulkis, Samuel; Lubin, Philip M.; Meyer, Stephan S.; Silverberg, Robert F.

    1990-01-01

    The Cosmic Background Explorer (CBE), NASA's cosmological satellite which will observe a radiative relic of the big bang, is discussed. The major questions connected to the big bang theory which may be clarified using the CBE are reviewed. The satellite instruments and experiments are described, including the Differential Microwave Radiometer, which measures the difference between microwave radiation emitted from two points on the sky, the Far-Infrared Absolute Spectrophotometer, which compares the spectrum of radiation from the sky at wavelengths from 100 microns to one cm with that from an internal blackbody, and the Diffuse Infrared Background Experiment, which searches for the radiation from the earliest generation of stars.

  5. Berkeley Low Background Facility

    SciTech Connect

    Thomas, K. J.; Norman, E. B.; Smith, A. R.; Poon, A. W. P.; Chan, Y. D.; Lesko, K. T.

    2015-08-17

    The Berkeley Low Background Facility (BLBF) at Lawrence Berkeley National Laboratory (LBNL) in Berkeley, California provides low background gamma spectroscopy services to a wide array of experiments and projects. The analysis of samples takes place within two unique facilities; locally within a carefully-constructed, low background laboratory on the surface at LBNL and at the Sanford Underground Research Facility (SURF) in Lead, SD. These facilities provide a variety of gamma spectroscopy services to low background experiments primarily in the form of passive material screening for primordial radioisotopes (U, Th, K) or common cosmogenic/anthropogenic products; active screening via neutron activation analysis for U,Th, and K as well as a variety of stable isotopes; and neutron flux/beam characterization measurements through the use of monitors. A general overview of the facilities, services, and sensitivities will be presented. Recent activities and upgrades will also be described including an overview of the recently installed counting system at SURF (recently relocated from Oroville, CA in 2014), the installation of a second underground counting station at SURF in 2015, and future plans. The BLBF is open to any users for counting services or collaboration on a wide variety of experiments and projects.

  6. China: Background Notes Series.

    ERIC Educational Resources Information Center

    Reams, Joanne Reppert

    Concise background information on the People's Republic of China is provided. The publication begins with a profile of the country, outlining the people, geography, economy, and membership in international organizations. The bulk of the document then discusses in more detail China's people, geography, history, government, education, economy, and…

  7. Building Background Knowledge

    ERIC Educational Resources Information Center

    Fisher, Douglas; Ross, Donna; Grant, Maria

    2010-01-01

    Too often, students enter our classrooms with insufficient knowledge of physical science. As a result, they have a difficult time understanding content in texts, lectures, and laboratory activities. This lack of background knowledge can have an impact on their ability to ask questions and wonder--both key components of inquiry. In this article,…

  8. An approach to the synthesis of dimeric resveratrol natural products via a palladium-catalyzed domino reaction

    PubMed Central

    Jeffrey, Jenna L.; Sarpong, Richmond

    2009-01-01

    A route for the rapid assembly of the carbon framework of several resveratrol natural products is presented. A palladium-catalyzed domino reaction of bromostilbene derivative 6 and tolane 7, involving two sequential Heck coupling reactions, provides access to the benzofulvene-based core of various resveratrol-derived natural products. The carbon skeleton of pallidol and its congeners is achieved by a Lewis acid-induced Nazarov-type oxidative cyclization of 9. PMID:20161322

  9. A novel geotechnical/geostatistical approach for exploration and production of natural gas from multiple geologic strata. Quarterly report, October 1, 1996--December 31, 1996

    SciTech Connect

    1997-06-01

    This document contains the Quarterly Report of a Novel Geotechnical/Geostatistical Approach for Exploration and Production of Natural Gas from Multiple Geologic Strata for October 1 - December 31, 1996. This report is presented to the US DOE, Office of Fossil Energy by the College of West Virginia. A brief summary update of the following ongoing projects is presented: production of natural gas from multiple geologic strata (including coal deposits), dewatering of producing wells, and descriptions of cold weather production problems. A brief update of the project in Poland where brine wastewater is converted into potable water is also mentioned.

  10. Faculty Approaches to Assessing Critical Thinking in the Humanities and the Natural and Social Sciences: Implications for General Education

    ERIC Educational Resources Information Center

    Nicholas, Mark C.; Labig, Chalmer E., Jr.

    2013-01-01

    An analysis of interviews, focus-group discussions, assessment instruments, and assignment prompts revealed that within general education, faculty assessed critical thinking as faceted using methods and criteria that varied epistemically across disciplines. Faculty approaches were misaligned with discipline-general institutional approaches.…

  11. The cosmic infrared background experiment

    NASA Astrophysics Data System (ADS)

    Bock, James; Battle, John; Cooray, Asantha; Kawada, Mitsunobu; Keating, Brian; Lange, Andrew; Lee, Dae-Hea; Matsumoto, Toshio; Matsuura, Shuji; Pak, Soojong; Renbarger, Tom; Sullivan, Ian; Tsumura, Kohji; Wada, Takehiko; Watabe, Toyoki

    2006-03-01

    The extragalactic background, based on absolute measurements reported by DIRBE and IRTS at 1.2 and 2.2 μm, exceeds the brightness derived from galaxy counts by up to a factor 5. Furthermore, both DIRBE and the IRTS report fluctuations in the near-infrared sky brightness that appear to have an extra-galactic origin, but are larger than expected from local ( z = 1-3) galaxies. These observations have led to speculation that a new class of high-mass stars or mini-quasars may dominate primordial star formation at high-redshift ( z ˜ 10-20), which, in order to explain the excess in the near-infrared background, must be highly luminous but produce a limited amount of metals and X-ray photons. Regardless of the nature of the sources, if a significant component of the near-infrared background comes from first-light galaxies, theoretical models generically predict a prominent near-infrared spectral feature from the redshifted Lyman cutoff, and a distinctive fluctuation power spectrum. We are developing a rocket-borne instrument (the Cosmic Infrared Background ExpeRiment, or CIBER) to search for signatures of primordial galaxy formation in the cosmic near-infrared extra-galactic background. CIBER consists of a wide-field two-color camera, a low-resolution absolute spectrometer, and a high-resolution narrow-band imaging spectrometer. The cameras will search for spatial fluctuations in the background on angular scales from 7″ to 2°, where a first-light galaxy signature is expected to peak, over a range of angular scales poorly covered by previous experiments. CIBER will determine if the fluctuations reported by the IRTS arise from first-light galaxies or have a local origin. In a short rocket flight CIBER has sensitivity to probe fluctuations 100× fainter than IRTS/DIRBE, with sufficient resolution to remove local-galaxy correlations. By jointly observing regions of the sky studied by Spitzer and ASTRO-F, CIBER will build a multi-color view of the near

  12. A combined approach to physical vulnerability of large cities exposed to natural hazards - the case study of Arequipa, Peru

    NASA Astrophysics Data System (ADS)

    Thouret, Jean-Claude; Ettinger, Susanne; Zuccaro, Giulio; Guitton, Mathieu; Martelli, Kim; Degregorio, Daniela; Nardone, Stefano; Santoni, Olivier; Magill, Christina; Luque, Juan Alexis; Arguedas, Ana

    2013-04-01

    Arequipa, the second largest city in Peru with almost one million inhabitants, is exposed to various natural hazards, such as earthquakes, landslides, flash floods, and volcanic eruptions. This study focuses on the vulnerability and response of housing, infrastructure and lifelines in Arequipa to flash floods and eruption induced hazards, notably lahars from El Misti volcano. We propose a combined approach for assessing physical vulnerability in a large city based on: (1) remote sensing utilizing high-resolution imagery (SPOT5, Google Earth Pro, Bing, Pléïades) to map the distribution and type of land use, properties of city blocks in terms of exposure to the hazard (elevation above river level, distance to channel, impact angle, etc.); (2) in situ survey of buildings and critical infrastructure (e.g., bridges) and strategic resources (e.g., potable water, irrigation, sewage); (3) information gained from interviews with engineers involved in construction works, previous crises (e.g., June 2001 earthquake) and risk mitigation in Arequipa. Remote sensing and mapping at the scale of the city has focused on three pilot areas, along the perennial Rio Chili valley that crosses the city and oasis from north to south, and two of the east-margin tributaries termed Quebrada (ravine): San Lazaro crossing the northern districts and Huarangal crossing the northeastern districts. Sampling of city blocks through these districts provides varying geomorphic, structural, historical, and socio-economic characteristics for each sector. A reconnaissance survey included about 900 edifices located in 40 city blocks across districts of the pilot areas, distinct in age, construction, land use and demographics. A building acts as a structural system and its strength and resistance to flashfloods and lahars therefore highly depends on the type of construction and the used material. Each building surveyed was assigned to one of eight building categories based on physical criteria (dominant

  13. Review: Natural tracers in fractured hard-rock aquifers in the Austrian part of the Eastern Alps—previous approaches and future perspectives for hydrogeology in mountain regions

    NASA Astrophysics Data System (ADS)

    Hilberg, Sylke

    2016-08-01

    Extensive in-depth research is required for the implementation of natural tracer approaches to hydrogeological investigation to be feasible in mountainous regions. This review considers the application of hydrochemical and biotic parameters in mountain regions over the past few decades with particular reference to the Austrian Alps, as an example for alpine-type mountain belts. A brief introduction to Austria's hydrogeological arrangement is given to show the significance of fractured hard-rock aquifers for hydrogeological science as well as for water supply purposes. A literature search showed that research concerning fractured hard-rock aquifers in Austria is clearly underrepresented to date, especially when taking the abundance of this aquifer type and the significance of this topic into consideration. The application of abiotic natural tracers (hydrochemical and isotope parameters) is discussed generally and by means of examples from the Austrian Alps. The potential of biotic tracers (microbiota and meiofauna) is elucidated. It is shown that the meiofauna approach to investigating fractured aquifers has not yet been applied in the reviewed region, nor worldwide. Two examples of new approaches in mountainous fractured aquifers are introduced: (1) use of CO2 partial pressure and calcite saturation of spring water to reconstruct catchments and flow dynamics (abiotic approach), and, (2) consideration of hard-rock aquifers as habitats to reconstruct aquifer conditions (biotic approach).

  14. Using a multicultural approach to teach chemistry and the nature of science to undergraduate non-majors

    NASA Astrophysics Data System (ADS)

    Goff, Peter; Boesdorfer, Sarah B.; Hunter, William

    2012-09-01

    This research documents the creation, implementation, and evaluation of a novel chemistry curriculum. The curriculum allowed students to create theories situated in a variety of cultures while they investigated chemical phenomena central to all civilizations; it was a way of synthesizing chemistry, the history and nature of science, inquiry, and multicultural education. Achieving both chemistry content and nature of science objectives were the main goals of the curriculum. A small sample of undergraduate students participated in the curriculum instead of attending a large lecture course. The novel curriculum covered the same chemistry topics as the large lecture course. Program efficacy was evaluated using a combination of grades, survey data, and interviews with the participating undergraduates. The results suggest that this curriculum was a successful start at engaging students and teaching them chemistry as well as nature of science concepts.

  15. C3: The Compositional Construction of Content: A New, More Effective and Efficient Way to Marshal Inferences from Background Knowledge that will Enable More Natural and Effective Communication with Automomous Systems

    DTIC Science & Technology

    2014-01-06

    in goal-driven tasks in artificial intelligence. With the maturation of statistically informed NLP techniques and the increased availability of large...event-based reasoning. The talk will be divided into two parts: in the first, I focus on the general role of events in AI, NLP , and linguistics, examining...and 1980s were abandoned by main-stream NLP re- search as part of the move to ‘empirical’ approaches that were made possible by the construction of

  16. A new approach to the determination of the synthetic or natural origin of red pigments through spectroscopic analysis

    NASA Astrophysics Data System (ADS)

    Franquelo, Maria Luisa; Perez-Rodriguez, Jose Luis

    2016-09-01

    This work suggests a way of differentiation between the natural or synthetic origin of inorganic materials that were historically used in the Cultural Heritage field. An exhaustive review of different reported procedures of synthesis of pigments was conducted, as well as a review of the accompanying minerals in case of natural pigments. The natural or synthetic origin of the pigments studied in this work was performed through the characterization of the accompanying minerals, in the case of the natural pigments, or the trace elements that are present as part of synthesis by-products or washing/purifying reagents and/or reactants that have only been partly removed in the final steps of these processes. This work characterized red pigments due to their wide variety, complexity and possibility of use in different mixtures. The following pigments were studied: cinnabar-vermilion, red lead and iron pigments. Also mixtures of these pigments between them and with red lake were also studied. Natural cinnabar was accompanied by silicon oxide (opal, chalcedony or quartz), calcite, clay minerals and, sometimes, pyrite. K together with S indicated a synthetic pigment (vermilion) obtained through the wet method. Nevertheless, K has not been found in layers containing only vermilion in our samples. The presence of Sn in some cases indicated vermilion that came from the dry process. K from the synthesis always appeared in the red lead pigment. The red natural ochre was confirmed by presence of clay minerals and iron. It should be said that Ca and S, and sometimes Al and K, were usually found in Mars red pigment. The presence of Al and Ca allowed the identification of carmine lake.

  17. A new approach to the determination of the synthetic or natural origin of red pigments through spectroscopic analysis.

    PubMed

    Franquelo, Maria Luisa; Perez-Rodriguez, Jose Luis

    2016-09-05

    This work suggests a way of differentiation between the natural or synthetic origin of inorganic materials that were historically used in the Cultural Heritage field. An exhaustive review of different reported procedures of synthesis of pigments was conducted, as well as a review of the accompanying minerals in case of natural pigments. The natural or synthetic origin of the pigments studied in this work was performed through the characterization of the accompanying minerals, in the case of the natural pigments, or the trace elements that are present as part of synthesis by-products or washing/purifying reagents and/or reactants that have only been partly removed in the final steps of these processes. This work characterized red pigments due to their wide variety, complexity and possibility of use in different mixtures. The following pigments were studied: cinnabar-vermilion, red lead and iron pigments. Also mixtures of these pigments between them and with red lake were also studied. Natural cinnabar was accompanied by silicon oxide (opal, chalcedony or quartz), calcite, clay minerals and, sometimes, pyrite. K together with S indicated a synthetic pigment (vermilion) obtained through the wet method. Nevertheless, K has not been found in layers containing only vermilion in our samples. The presence of Sn in some cases indicated vermilion that came from the dry process. K from the synthesis always appeared in the red lead pigment. The red natural ochre was confirmed by presence of clay minerals and iron. It should be said that Ca and S, and sometimes Al and K, were usually found in Mars red pigment. The presence of Al and Ca allowed the identification of carmine lake.

  18. Natural ELF noise evaluation for TSS emissions detection on the Earth's surface. The electric field component approach

    NASA Technical Reports Server (NTRS)

    Tacconi, G.

    1986-01-01

    The preliminary estimate of the local noise structure in the proximity of a receiver is essential to establishing the detectability of a given signal in presence of such noise. The possibility of detecting the Electric Field Component of the background noise by means of electric dipoles horizontally placed on the sea bed in shallow water is outlined, in order to find its spectral and statistical characteristics for the definition of the optimal receiving system.

  19. Backgrounder: The MAB Programme.

    ERIC Educational Resources Information Center

    United Nations Educational, Scientific, and Cultural Organization, Paris (France). Office of Public Information.

    The Man and the Biosphere Programme (MAB) was launched in November 1971 under the auspices of Unesco. Its aim is to help to develop scientific knowledge with a view to the rational management and conservation of natural resources, to train qualified personnel in this field, and to disseminate the knowledge acquired both to the decision-makers and…

  20. Background Information for Educators

    ERIC Educational Resources Information Center

    US Environmental Protection Agency, 2001

    2001-01-01

    Mercury is a naturally occurring and widely used element that can cause health and ecological problems when released to the environment through human activities. Though a national and even international issue, the health and environmental impacts of mercury are best understood when studied at the local level. "Mercury: An Educator's Toolkit"…

  1. Estimating U.S. Methane Emissions from the Natural Gas Supply Chain. Approaches, Uncertainties, Current Estimates, and Future Studies

    SciTech Connect

    Heath, Garvin; Warner, Ethan; Steinberg, Daniel; Brandt, Adam

    2015-08-01

    A growing number of studies have raised questions regarding uncertainties in our understanding of methane (CH4) emissions from fugitives and venting along the natural gas (NG) supply chain. In particular, a number of measurement studies have suggested that actual levels of CH4 emissions may be higher than estimated by EPA" tm s U.S. GHG Emission Inventory. We reviewed the literature to identify the growing number of studies that have raised questions regarding uncertainties in our understanding of methane (CH4) emissions from fugitives and venting along the natural gas (NG) supply chain.

  2. Prospecting for new bacterial metabolites: a glossary of approaches for inducing, activating and upregulating the biosynthesis of bacterial cryptic or silent natural products.

    PubMed

    Zarins-Tutt, Joseph Scott; Barberi, Tania Triscari; Gao, Hong; Mearns-Spragg, Andrew; Zhang, Lixin; Newman, David J; Goss, Rebecca Jane Miriam

    2016-01-01

    Covering: up to 2015. Over the centuries, microbial secondary metabolites have played a central role in the treatment of human diseases and have revolutionised the pharmaceutical industry. With the increasing number of sequenced microbial genomes revealing a plethora of novel biosynthetic genes, natural product drug discovery is entering an exciting second golden age. Here, we provide a concise overview as an introductory guide to the main methods employed to unlock or up-regulate these so called 'cryptic', 'silent' and 'orphan' gene clusters, and increase the production of the encoded natural product. With a predominant focus on bacterial natural products we will discuss the importance of the bioinformatics approach for genome mining, the use of first different and simple culturing techniques and then the application of genetic engineering to unlock the microbial treasure trove.

  3. Towards the Application of a River Management Approach Encompassing most Natural Process Drivers : Lessons Learned from Freedom Space for Rivers in Quebec (Canada)

    NASA Astrophysics Data System (ADS)

    Biron, P.; Buffin-Belanger, T. K.; Massé, S.

    2015-12-01

    The consensus around the need for a shift in river management approaches to include more natural processes is steadily growing amongst scientists, practitioners and governmental agencies. Not only is this a sound way to increase resilience of fluvial systems and adapt to climate change, but it will likely result in improved water quality and better aquatic habitat. This paper presents the freedom space for rivers approach which we have developed recently in Quebec (Canada) to combine natural processes related to mobility, flooding and riparian wetland connectivity into a single index. The approach was applied to 3 contrasted rivers (de la Roche, Yamaska Sud-Est and Matane) to produce two main levels of freedom space, operating at two time scales: "short" (in geomorphic terms, i.e. < 50 years) and long (floodplain renewal, ranging from several decades to centuries). For each river, a cost-benefit analysis revealed economic benefits over a 50-year period when taking into account ecosystem services. There is now a growing interest within ministries and watershed agencies to implement such a management approach, but also strong inertia and resistance to change, particularly in agricultural watersheds. Our observations reveal that for such a shift in paradigm to operate, hydrogeomorphogical concepts must be better understood by those in charge of managing rivers, which is currently not the case in Quebec. The role of integrating scientific knowledge in the implementation of a freedom space for rivers management scheme will be discussed based on case studies in 3 watersheds: rivière du Nord, Coaticook and Mitis/Neigette. The original approach was applied only to the main branches, however the second phase of the project is also aiming to determine whether the impact of leaving more space for natural rivers to operate would be more beneficial in headwater tributaries than in higher-order reaches.

  4. Devising an Instrument for Determining Students' Preparedness for an Education through Science Learning Approach within the Topic of Natural Hazards

    ERIC Educational Resources Information Center

    Cerulli, D.; Holbrook, J.; Mander, Ü.

    2016-01-01

    As global average temperatures rise, there has been an increase in the frequency and magnitude of meteorological natural hazards. To survive in the world and thrive in the work place, students need to utilize educational skills (such as creative thinking, non-routine problem solving, collaboration and systems thinking) and become independent…

  5. Candidate soil indicators for monitoring the progress of constructed wetlands toward a natural state: a statistical approach

    USGS Publications Warehouse

    Stapanian, Martin A.; Adams, Jean V.; Fennessy, M. Siobhan; Mack, John; Micacchion, Mick

    2013-01-01

    A persistent question among ecologists and environmental managers is whether constructed wetlands are structurally or functionally equivalent to naturally occurring wetlands. We examined 19 variables collected from 10 constructed and nine natural emergent wetlands in Ohio, USA. Our primary objective was to identify candidate indicators of wetland class (natural or constructed), based on measurements of soil properties and an index of vegetation integrity, that can be used to track the progress of constructed wetlands toward a natural state. The method of nearest shrunken centroids was used to find a subset of variables that would serve as the best classifiers of wetland class, and error rate was calculated using a five-fold cross-validation procedure. The shrunken differences of percent total organic carbon (% TOC) and percent dry weight of the soil exhibited the greatest distances from the overall centroid. Classification based on these two variables yielded a misclassification rate of 11% based on cross-validation. Our results indicate that % TOC and percent dry weight can be used as candidate indicators of the status of emergent, constructed wetlands in Ohio and for assessing the performance of mitigation. The method of nearest shrunken centroids has excellent potential for further applications in ecology.

  6. Using a Multicultural Approach to Teach Chemistry and the Nature of Science to Undergraduate Non-Majors

    ERIC Educational Resources Information Center

    Goff, Peter; Boesdorfer, Sarah B.; Hunter, William

    2012-01-01

    This research documents the creation, implementation, and evaluation of a novel chemistry curriculum. The curriculum allowed students to create theories situated in a variety of cultures while they investigated chemical phenomena central to all civilizations; it was a way of synthesizing chemistry, the history and nature of science, inquiry, and…

  7. Emphasizing the History of Genetics in an Explicit and Reflective Approach to Teaching the Nature of Science: A Pilot Study

    ERIC Educational Resources Information Center

    Williams, Cody Tyler; Rudge, David Wÿss

    2016-01-01

    Science education researchers have long advocated the central role of the nature of science (NOS) for our understanding of scientific literacy. NOS is often interpreted narrowly to refer to a host of epistemological issues associated with the process of science and the limitations of scientific knowledge. Despite its importance, practitioners and…

  8. Transfer of Nature of Science Understandings into Similar Contexts: Promises and Possibilities of an Explicit Reflective Approach

    ERIC Educational Resources Information Center

    Khishfe, Rola

    2013-01-01

    The purpose of this study was to (a) investigate the effectiveness of explicit nature of science (NOS) instruction in the context of controversial socioscientific issues and (b) explore whether the transfer of acquired NOS understandings, which were explicitly taught in the context of one socioscientific context, into other similar contexts…

  9. Joy of Nature, "Friluftsliv" Education and Self: Combining Narrative and Cultural-Ecological Approaches to Environmental Sustainability

    ERIC Educational Resources Information Center

    Gurholt, Kirsti Pedersen

    2014-01-01

    Autobiographies of prominent environmentalists describe that their early lives have been rich in personal experiences of nature. The early childhood experiences of philosopher and climber Arne Naess (1912-2009) inspired the development of deep ecology philosophy, which markedly influenced the emergence of Norwegian "friluftsliv"…

  10. New Tools and New Approaches to Improve the Assessment and Evaluation of Monitored Natural Attenuation of Organic Compoundsin Ground Water

    EPA Science Inventory

    In the years since publication of the U.S. Air Force and U.S. EPA technical protocols for evaluating Monitored Natural Attenuation, MNA had found widespread application to organic contaminants in ground water. These documents were issued more than a decade ago; the science has m...

  11. Bike Helmets and Black Riders: Experiential Approaches to Helping Students Understand Natural Hazard Assessment and Mitigation Issues

    NASA Astrophysics Data System (ADS)

    Stein, S. A.; Kley, J.; Hindle, D.; Friedrich, A. M.

    2014-12-01

    Defending society against natural hazards is a high-stakes game of chance against nature, involving tough decisions. How should a developing nation allocate its budget between building schools for towns without ones or making existing schools earthquake-resistant? Does it make more sense to build levees to protect against floods, or to prevent development in the areas at risk? Would more lives be saved by making hospitals earthquake-resistant, or using the funds for patient care? These topics are challenging because they are far from normal experience, in that they involve rare events and large sums. To help students in natural hazard classes conceptualize them, we pose tough and thought-provoking questions about complex issues involved and explore them together via lectures, videos, field trips, and in-class and homework questions. We discuss analogous examples from the students' experiences, drawing on a new book "Playing Against Nature, Integrating Science and Economics to Mitigate Natural Hazards in an Uncertain World". Asking whether they wear bicycle helmets and why or why not shows the cultural perception of risk. Individual students' responses vary, and the overall results vary dramatically between the US, UK, and Germany. Challenges in hazard assessment in an uncertain world are illustrated by asking German students whether they buy a ticket on public transportation - accepting a known cost - or "ride black" - not paying but risking a heavy fine if caught. We explore the challenge of balancing mitigation costs and benefits via the question "If you were a student in Los Angeles, how much more would you pay in rent each month to live in an earthquake-safe building?" Students learn that interdisciplinary thinking is needed, and that due to both uncertainties and sociocultural factors, no unique or right strategies exist for a particular community, much the less all communities. However, we can seek robust policies that give sensible results given

  12. Leakage detection of Marcellus Shale natural gas at an Upper Devonian gas monitoring well: a 3-d numerical modeling approach.

    PubMed

    Zhang, Liwei; Anderson, Nicole; Dilmore, Robert; Soeder, Daniel J; Bromhal, Grant

    2014-09-16

    Potential natural gas leakage into shallow, overlying formations and aquifers from Marcellus Shale gas drilling operations is a public concern. However, before natural gas could reach underground sources of drinking water (USDW), it must pass through several geologic formations. Tracer and pressure monitoring in formations overlying the Marcellus could help detect natural gas leakage at hydraulic fracturing sites before it reaches USDW. In this study, a numerical simulation code (TOUGH 2) was used to investigate the potential for detecting leaking natural gas in such an overlying geologic formation. The modeled zone was based on a gas field in Greene County, Pennsylvania, undergoing production activities. The model assumed, hypothetically, that methane (CH4), the primary component of natural gas, with some tracer, was leaking around an existing well between the Marcellus Shale and the shallower and lower-pressure Bradford Formation. The leaky well was located 170 m away from a monitoring well, in the Bradford Formation. A simulation study was performed to determine how quickly the tracer monitoring could detect a leak of a known size. Using some typical parameters for the Bradford Formation, model results showed that a detectable tracer volume fraction of 2.0 × 10(-15) would be noted at the monitoring well in 9.8 years. The most rapid detection of tracer for the leak rates simulated was 81 days, but this scenario required that the leakage release point was at the same depth as the perforation zone of the monitoring well and the zones above and below the perforation zone had low permeability, which created a preferred tracer migration pathway along the perforation zone. Sensitivity analysis indicated that the time needed to detect CH4 leakage at the monitoring well was very sensitive to changes in the thickness of the high-permeability zone, CH4 leaking rate, and production rate of the monitoring well.

  13. Ultraviolet Background Radiation (Preprint)

    DTIC Science & Technology

    1991-03-01

    5.4 Apollo-Soyuz 3 5 5.5 Evidence for Scattering From Dust ? 3 8 5.6 More Evidence For Scattering From Dust ? 4 0 5.7 More Observations 4 2...Emission from cold interstellar dust . This has been observed by IRAS as the 100 u.m cosmic cirrus (64). The existence of such dust at moderate and... DUST 4 6 CONCLUSIONS 4 7 6.1 Spectral Structure in the Diffuse 4 7 Ultraviolet Background 6.2 Is There Light Scattered From Dust ? 4 7 6.3

  14. Cosmic Background Radiation

    NASA Astrophysics Data System (ADS)

    Sidharth, B. G.; Valluri, S. R.

    2015-08-01

    It is shown that a collection of photons with nearly the same frequency exhibits a "condensation" type of phenomenon corresponding to a peak intensity. The observed cosmic background radiation can be explained from this standpoint. We have obtained analogous results by extremization of the occupation number for photons with the use of the Lambert W function. Some of the interesting applications of this function are briefly discussed in the context of graphene which exhibits an interesting two dimensional structure with several characteristic properties and diverse practical applications.

  15. Warping Background Subtraction

    DTIC Science & Technology

    2010-06-01

    significant motion, as demonstrated on image sequences of birds at a feeder station and more general, [11]. Fur- thermore, the implicit warping model...motion compared to (2-4) and is less blurred than (5). The relative difference between birds and the swinging feeder station is larger as well for our...when the camera is not moving. Natural environments, such as the forest canopy, present a significant challenge because of the complex occlusion

  16. Carbon export in the naturally iron-fertilized Kerguelen area of the Southern Ocean based on the 234Th approach

    NASA Astrophysics Data System (ADS)

    Planchon, F.; Ballas, D.; Cavagna, A.-J.; Bowie, A. R.; Davies, D.; Trull, T.; Laurenceau, E.; Van Der Merwe, P.; Dehairs, F.

    2014-11-01

    The Kerguelen Plateau region in the Indian sector of the Southern Ocean supports annually a large-scale phytoplankton bloom which is naturally fertilized with iron. As part of the second KErguelen Ocean and Plateau compared Study expedition (KEOPS2) in austral spring (October-November 2011), we examined upper-ocean Particulate Organic Carbon (POC) export using the 234Th approach. We aimed at characterizing the spatial and the temporal variability of POC export production at high productivity sites over and downstream the Kerguelen plateau. Export production is compared to a High Nutrient Low Chlorophyll area upstream of the plateau in order to assess the impact of iron-induced productivity on the vertical export of carbon. Deficits in 234Th activities relative to its parent nuclide 238U were observed at all stations in surface waters, indicating that scavenging by particles occurred during the early stages of the phytoplankton bloom. 234Th export was lowest at reference station R-2 (412 ± 134 dpm m-2 d-1) and highest inside a~permanent meander of the Polar Front (PF) at stations E (1995 ± 176 dpm m-2 d-1, second visit E-3) where a detailed time series was obtained as part of a~pseudo-lagrangian study. 234Th export over the central plateau was relatively limited at station A3 early (776 ± 171 dpm m-2 d-1, first visit A3-1) and late in the survey (993 ± 223 dpm m-2 d-1, second visit A3-2), but it was higher at high biomass stations TNS-8 (1372 ± 255 dpm m-2 d-1) and E-4W (1068 ± 208 dpm m-2 d-1) in waters which could be considered as derived from plateau. Limited 234Th export of 973 ± 207 dpm m-2 d-1 was also found in the northern branch of the Kerguelen bloom located downstream of the island, north of the PF (station F-L). The 234Th results support that Fe fertilization increased particle export in all iron fertilized waters. The impact was greatest in the recirculation feature (3-4 fold at 200 m depth), but more moderate over the central Kerguelen plateau

  17. The Backgrounds Data Center

    NASA Technical Reports Server (NTRS)

    Snyder, W. A.; Gursky, H.; Heckathorn, H. M.; Lucke, R. L.; Berg, S. L.; Dombrowski, E. G.; Kessel, R. A.

    1993-01-01

    The Strategic Defense Initiative Organization has created data centers for midcourse, plumes, and backgrounds phenomenologies. The Backgrounds Data Center (BDC) has been designated as the prime archive for data collected by SDIO programs. The BDC maintains a Summary Catalog that contains 'metadata,' that is, information about data, such as when the data were obtained, what the spectral range of the data is, and what region of the Earth or sky was observed. Queries to this catalog result in a listing of all data sets (from all experiments in the Summary Catalog) that satisfy the specified criteria. Thus, the user can identify different experiments that made similar observations and order them from the BDC for analysis. On-site users can use the Science Analysis Facility (SAFE for this purpose. For some programs, the BDC maintains a Program Catalog, which can classify data in as many ways as desired (rather than just by position, time, and spectral range as in the Summary Catalog). For example, data sets could be tagged with such diverse parameters as solar illumination angle, signal level, or the value of a particular spectral ratio, as long as these quantities can be read from the digital record or calculated from it by the ingest program. All unclassified catalogs and unclassified data will be remotely accessible.

  18. Positive approach: Implications for the relation between number theory and geometry, including connection to Santilli mathematics, from Fibonacci reconstitution of natural numbers and of prime numbers

    NASA Astrophysics Data System (ADS)

    Johansen, Stein E.

    2014-12-01

    The paper recapitulates some key elements in previously published results concerning exact and complete reconstitution of the field of natural numbers, both as ordinal and as cardinal numbers, from systematic unfoldment of the Fibonacci algorithm. By this natural numbers emerge as Fibonacci "atoms" and "molecules" consistent with the notion of Zeckendorf sums. Here, the sub-set of prime numbers appears not as the primary numbers, but as an epistructure from a deeper Fibonacci constitution, and is thus targeted from a "positive approach". In the Fibonacci reconstitution of number theory natural numbers show a double geometrical aspect: partly as extension in space and partly as position in a successive structuring of space. More specifically, the natural numbers are shown to be distributed by a concise 5:3 code structured from the Fibonacci algorithm via Pascal's triangle. The paper discusses possible implications for the more general relation between number theory and geometry, as well as more specifically in relation to hadronic mathematics, initiated by R.M. Santilli, and also briefly to some other recent science linking number theory more directly to geometry and natural systems.

  19. Positive approach: Implications for the relation between number theory and geometry, including connection to Santilli mathematics, from Fibonacci reconstitution of natural numbers and of prime numbers

    SciTech Connect

    Johansen, Stein E.

    2014-12-10

    The paper recapitulates some key elements in previously published results concerning exact and complete reconstitution of the field of natural numbers, both as ordinal and as cardinal numbers, from systematic unfoldment of the Fibonacci algorithm. By this natural numbers emerge as Fibonacci 'atoms' and 'molecules' consistent with the notion of Zeckendorf sums. Here, the sub-set of prime numbers appears not as the primary numbers, but as an epistructure from a deeper Fibonacci constitution, and is thus targeted from a 'positive approach'. In the Fibonacci reconstitution of number theory natural numbers show a double geometrical aspect: partly as extension in space and partly as position in a successive structuring of space. More specifically, the natural numbers are shown to be distributed by a concise 5:3 code structured from the Fibonacci algorithm via Pascal's triangle. The paper discusses possible implications for the more general relation between number theory and geometry, as well as more specifically in relation to hadronic mathematics, initiated by R.M. Santilli, and also briefly to some other recent science linking number theory more directly to geometry and natural systems.

  20. Synthesis of the Danish Experience with Combating Nutrient Pollution of Surface Waters: The Old Regulatory Approach and a New Targeted Approach Utilising the Natural Attenuation Capacity in Landscapes

    NASA Astrophysics Data System (ADS)

    Kronvang, Brian; Windolf, Jørgen; Blicher-Mathiesen, Gitte; Tornbjerg, Henrik; Højberg, Anker; Rieman, Bo

    2016-04-01

    Excess nitrogen (N) and phosphorus (P) emissions to surface waters are a high priority environmental problem worldwide for protection of water resources in times of population growth and climate change. As clean water is a scarce resource the struggle for reducing nutrient emissions are an ongoing issue for many countries and regions. Since the mid1980s a wide range of national regulatory general measures have been implemented to reduce land based nitrogen (N) and phosphorus (P) loadings of the Danish aquatic environment. These measures have addressed both point source emissions and emissions from diffuse sources especially from agricultural production. Following nearly 4 decades of combating nutrient pollution our surface waters such as lakes and estuaries are only slowly responding on the 50% reduction in N and 56% reduction in P. Therefore, the implementation of the EU Water Framework Directive in Danish surface waters still call for further reductions of N and P loadings. Introduction of a new paradigm of targeted implemented measures was the proposed outcome of a Commission on Nature and Agriculture established by the Danish Government in 2013. Their White Book points to the need of increased growth and better environment through more targeted and efficient regulation using advanced technological mitigation methods that are implemented intelligently according to the local natural attenuation capacity for nutrients in the landscape. As a follow up a national consensus model for N was established chaining existing leaching, 3D groundwater and surface water models. The new model concept enables a calculation of the N dynamics and attenuation capacity within a scale of 15 km2. Moreover, several research projects have been conducted to investigate the effect of a suite of targeted mitigation measures such as restored natural wetlands, constructed wetlands, controlled drainage and intelligent buffer zones. The outcome of six Danish management plans for nutrient load

  1. Methylene blue removal from contaminated waters using heterogeneous catalytic ozonation promoted by natural zeolite: mechanism and kinetic approach.

    PubMed

    Valdés, H; Tardón, R F; Zaror, C A

    2012-09-01

    This paper presents experimental results of a methylene blue removal system based on heterogeneous catalytic ozonation in the presence of natural zeolite. The effect of pH (2-10) and the presence of radical scavengers (acetate ions) on homogeneous and heterogeneous ozonation systems are assessed at laboratory scale. Results show that heterogeneous catalytic ozonation using natural zeolite increases methylene blue removal rate with respect to the single ozonation process at all pH values. The inhibitory effect of free-radical scavengers is impaired by zeolite, suggesting that methylene blue oxidation reactions take place mainly on the zeolite surface. The increase in methylene blue removal rate could be related to ozone interaction with hydroxyl groups present on the zeolite surface (S--OH2(+), S--OH, S--O(-)), which plays a key role in the reaction mechanism.

  2. Vibrational spectral investigation and natural bond orbital analysis of pharmaceutical compound 7-Amino-2,4-dimethylquinolinium formate - DFT approach

    NASA Astrophysics Data System (ADS)

    Suresh, D. M.; Amalanathan, M.; Sebastian, S.; Sajan, D.; Hubert Joe, I.; Bena Jothy, V.; Nemec, Ivan

    2013-11-01

    The molecular geometry, the normal mode frequencies and corresponding vibrational assignments, natural bond orbital analysis and the HOMO-LUMO analysis of 7-Amino-2,4-dimethylquinolinium formate in the ground state were performed by B3LYP levels of theory using the 6-31G(d) basis set. The optimised bond lengths and bond angles are in good agreement with the X-ray data. The vibrational spectra of the title compound which is calculated by DFT method, reproduces vibrational wave numbers and intensities with an accuracy which allows reliable vibrational assignments. The possibility of N-H⋯O hydrogen bonding was identified using NBO analysis. Natural bond orbital analysis confirms the presence of intramolecular charge transfer and the hydrogen bonding interaction.

  3. Vibrational spectral investigation and natural bond orbital analysis of pharmaceutical compound 7-Amino-2,4-dimethylquinolinium formate - DFT approach.

    PubMed

    Suresh, D M; Amalanathan, M; Sebastian, S; Sajan, D; Hubert Joe, I; Bena Jothy, V; Nemec, Ivan

    2013-11-01

    The molecular geometry, the normal mode frequencies and corresponding vibrational assignments, natural bond orbital analysis and the HOMO-LUMO analysis of 7-Amino-2,4-dimethylquinolinium formate in the ground state were performed by B3LYP levels of theory using the 6-31G(d) basis set. The optimised bond lengths and bond angles are in good agreement with the X-ray data. The vibrational spectra of the title compound which is calculated by DFT method, reproduces vibrational wave numbers and intensities with an accuracy which allows reliable vibrational assignments. The possibility of N-H⋯O hydrogen bonding was identified using NBO analysis. Natural bond orbital analysis confirms the presence of intramolecular charge transfer and the hydrogen bonding interaction.

  4. Curcumin and Resveratrol as Promising Natural Remedies with Nanomedicine Approach for the Effective Treatment of Triple Negative Breast Cancer

    PubMed Central

    Shindikar, Amol; Singh, Akshita; Nobre, Malcolm; Kirolikar, Saurabh

    2016-01-01

    Researchers have made considerable progress in last few decades in understanding mechanisms underlying pathogenesis of breast cancer, its phenotypes, its molecular and genetic changes, its physiology, and its prognosis. This has allowed us to identify specific targets and design appropriate chemical entities for effective treatment of most breast cancer phenotypes, resulting in increased patient survivability. Unfortunately, these strategies have been largely ineffective in the treatment of triple negative breast cancer (TNBC). Hormonal receptors lacking render the conventional breast cancer drugs redundant, forcing scientists to identify novel targets for treatment of TNBC. Two natural compounds, curcumin and resveratrol, have been widely reported to have anticancer properties. In vitro and in vivo studies show promising results, though their effectiveness in clinical settings has been less than satisfactory, owing to their feeble pharmacokinetics. Here we discuss these naturally occurring compounds, their mechanism as anticancer agents, their shortcomings in translational research, and possible methodology to improve their pharmacokinetics/pharmacodynamics with advanced drug delivery systems. PMID:27242900

  5. Approaches by the US National Institutes of Health to support rigorous scientific research on dietary supplements and natural products.

    PubMed

    Kuszak, A J; Hopp, D C; Williamson, J S; Betz, J M; Sorkin, B C

    2016-01-01

    Mechanistic, clinical, and epidemiological research relevant to dietary supplements (DS) is supported by the U.S. National Institutes of Health. The Office of Dietary Supplements and the National Center for Complementary and Integrative Health promote the development and appropriate use of rigorous and comprehensive DS analyses which are critical for research reproducibility, particularly when the investigational DS include chemically complex natural products with unclear mechanisms of action.

  6. Application of the BRAFO-tiered approach for benefit-risk assessment to case studies on natural foods.

    PubMed

    Watzl, Bernhard; Gelencsér, Eva; Hoekstra, Jeljer; Kulling, Sabine; Lydeking-Olsen, Eva; Rowland, Ian; Schilter, Benoît; van Klaveren, Jakob; Chiodini, Alessandro

    2012-11-01

    There is evidence that consumption of fish, especially oily fish, has substantial beneficial effects on health. In particular an inverse relationship of oily fish intake to coronary heart disease incidence has been established. These beneficial effects are ascribed to fish oil components including long chain ω-3 polyunsaturated fatty acids. On the other hand it should be noted that oily fish also contains hazardous substances such as dioxins, PCBs and methylmercury. Soy consumption has been associated with potential beneficial and adverse effects. The claimed benefits include reduced risk of cardiovascular disease; osteoporosis, breast and prostate cancer whereas potential adverse effects include impaired thyroid function, disruption of sex hormone levels, changes in reproductive function and increased breast cancer risk The two cases of natural foods highlight the need to consider both risks and benefits in order to establish the net health impact associated to the consumption of specific food products. Within the Sixth Framework programme of the European Commission, the BRAFO project was funded to develop a framework that allows for the quantitative comparison of human health risks and benefits in relation to foods and food compounds. This paper describes the application of the developed framework to two natural foods, farmed salmon and soy protein. We conclude that the BRAFO methodology is highly applicable to natural foods. It will help the benefit-risk managers in selecting the appropriate dietary recommendations for the population.

  7. A new approach to drug discovery: high-throughput screening of microbial natural extracts against Aspergillus fumigatus using resazurin.

    PubMed

    Monteiro, Maria Cândida; de la Cruz, Mercedes; Cantizani, Juan; Moreno, Catalina; Tormo, José R; Mellado, Emilia; De Lucas, J Ramón; Asensio, Francisco; Valiante, Vito; Brakhage, Axel A; Latgé, Jean-Paul; Genilloud, Olga; Vicente, Francisca

    2012-04-01

    Natural products are an inexhaustible source for drug discovery. However, the validation and selection of primary screening assays are vital to guarantee a selection of extracts or molecules with relevant pharmacological action and worthy of following up. The assay must be rapid, simple, easy to implement, and produce quick results and preferably at a low cost. In this work, we developed and validated a colorimetric microtiter assay using the resazurin viability dye. The parameters of the resazurin method for high-throughput screening (HTS) using natural extracts against Aspergillus fumigatus were optimized and set up. The extracts plus RPMI-1640 modified medium containing the spores and 0.002% resazurin were added per well. The fluorescence was read after 24 to 30 h of incubation. The resazurin proved to be as suitable as Alamar Blue for determining the minimal inhibitory concentration of different antifungals against A. fumigatus and effective to analyze fungicidal and fungistatic compounds. An HTS of 12 000 microbial extracts was carried out against two A. fumigatus strains, and 2.7% of the extracts displayed antifungal activity. Our group has been the first to use this methodology for screening a collection of natural extracts to identify compounds with antifungal activity against the medically important human pathogen A. fumigatus.

  8. Development of Proteogenomic Approaches to Analyze the Role of Virus-Microbe Interactions in Shaping Natural Microbial Communities

    SciTech Connect

    Banfield, Jillian; Breitbart, Mya; VerBerkmoes, Nathan

    2014-04-25

    CRISPRs (clustered regularly interspaced short palindromic repeats) are adaptive immune systems in Bacteria and Archaea. Transcripts of the spacers that separate the repeats confer immunity through sequence identity with a targeted region (proto-spacer) in phage/viral, plasmid, or other foreign DNA. Short sequences immediately flanking the proto-spacer (proto-spacer adjacent motifs—PAMs) are important in both procuring spacers from and providing immunity to targeted sequences. New spacers are incorporated unidirectionally at the leader end of the CRISPR loci, thus recording a timeline of recent viral exposure. In the early phase of our research, we documented extremely rapid diversification of the CRISPR loci in natural populations [Tyson and Banfield, 2008] matched by high levels of sequence variation in natural viral populations [Andersson and Banfield, 2008]. Since then, in a genetically tractable model laboratory system, we have 1) tracked phage mutation and CRISPR diversification, and in a natural model system, we have 2) examined population history via over time, 3) investigated the timescale over which spacers become ineffective and the process by which ineffective spacers are removed, and 4) analyzed viral diversity. In addition to research activities, our group has organized five international CRISPR meetings, the fifth to be held at University of California, Berkeley in June 2012. Most importantly, the project provided the majority of funding support for Christine Sun (Ph.D. 2012).

  9. Application of natural citric acid sources and their role on arsenic removal from drinking water: a green chemistry approach.

    PubMed

    Majumder, Santanu; Nath, Bibhash; Sarkar, Simita; Islam, Sk Mijanul; Bundschuh, Jochen; Chatterjee, Debashis; Hidalgo, Manuela

    2013-11-15

    Solar Oxidation and Removal of Arsenic (SORAS) is a low-cost non-hazardous technique for the removal of arsenic (As) from groundwater. In this study, we tested the efficiency of natural citric acid sources extracted from tomato, lemon and lime to promote SORAS for As removal at the household level. The experiment was conducted in the laboratory using both synthetic solutions and natural groundwater samples collected from As-polluted areas in West Bengal. The role of As/Fe molar ratios and citrate doses on As removal efficiency were checked in synthetic samples. The results demonstrate that tomato juice (as citric acid) was more efficient to remove As from both synthetic (percentage of removal: 78-98%) and natural groundwater (90-97%) samples compared to lemon (61-83% and 79-85%, respectively) and lime (39-69% and 63-70%, respectively) juices. The As/Fe molar ratio and the citrate dose showed an 'optimized central tendency' on As removal. Anti-oxidants, e.g. 'hydroxycinnamates', found in tomato, were shown to have a higher capacity to catalyze SORAS photochemical reactions compared to 'flavanones' found in lemon or lime. The application of this method has several advantages, such as eco- and user- friendliness and affordability at the household level compared to other low-cost techniques.

  10. Application of laccase-natural mediator systems to sisal pulp: an effective approach to biobleaching or functionalizing pulp fibres?

    PubMed

    Aracri, Elisabetta; Colom, Josep F; Vidal, Teresa

    2009-12-01

    The effects of laccase-natural mediator systems (LMS) on sisal pulp and their potential for either biobleaching or functionalizing (via radical-coupling) its fibres were investigated. The enzyme treatment (L stage) was followed by extraction with hydrogen peroxide in order to determine whether observable effects could be enhanced by removing LMS-modified lignin. Four different plant phenols [viz. the p-hydroxycinnamic compounds sinapic acid (SNC), ferulic acid (FRC), coniferyl aldehyde (CLD) and sinapyl aldehyde (SLD)] were used as laccase redox mediators and their effects on pulp and effluents compared with those of the synthetic compound 1-hydroxybenzotriazole (HBT). During the L stage performed with HBT, laccase underwent a loss of 99% and 78% of the initial activity, in the absence and presence of pulp, respectively. With natural mediators inactivation was markedly reduced, being the residual activity between 65% and 100% of the initial one, in the presence of pulp. The pulp was found to protect the enzyme against inactivation: the activity was only reduced by 45% in its presence. Under the operating conditions used the natural mediators proved less efficient than HBT in facilitating pulp bleaching; rather, they tended to bind to pulp fibres. This effect could be used to functionalize fibres in order to improve intrinsic properties of pulp or introducing novel ones (e.g. antimicrobial, antioxidant, optical properties, etc.). This paper shows for the first time the application of laccase-mediator systems to sisal pulp.

  11. Gamma-Ray Background Variability in Mobile Detectors

    NASA Astrophysics Data System (ADS)

    Aucott, Timothy John

    Gamma-ray background radiation significantly reduces detection sensitivity when searching for radioactive sources in the field, such as in wide-area searches for homeland security applications. Mobile detector systems in particular must contend with a variable background that is not necessarily known or even measurable a priori. This work will present measurements of the spatial and temporal variability of the background, with the goal of merging gamma-ray detection, spectroscopy, and imaging with contextual information--a "nuclear street view" of the ubiquitous background radiation. The gamma-ray background originates from a variety of sources, both natural and anthropogenic. The dominant sources in the field are the primordial isotopes potassium-40, uranium-238, and thorium-232, as well as their decay daughters. In addition to the natural background, many artificially-created isotopes are used for industrial or medical purposes, and contamination from fission products can be found in many environments. Regardless of origin, these backgrounds will reduce detection sensitivity by adding both statistical as well as systematic uncertainty. In particular, large detector arrays will be limited by the systematic uncertainty in the background and will suffer from a high rate of false alarms. The goal of this work is to provide a comprehensive characterization of the gamma-ray background and its variability in order to improve detection sensitivity and evaluate the performance of mobile detectors in the field. Large quantities of data are measured in order to study their performance at very low false alarm rates. Two different approaches, spectroscopy and imaging, are compared in a controlled study in the presence of this measured background. Furthermore, there is additional information that can be gained by correlating the gamma-ray data with contextual data streams (such as cameras and global positioning systems) in order to reduce the variability in the background

  12. The indirect nature of social motives: the relation of social approach and avoidance motives with likeability via extraversion and agreeableness.

    PubMed

    Nikitin, Jana; Freund, Alexandra M

    2015-02-01

    The current study tested assumptions derived from the whole-trait theory (Fleeson, 2012), which proposes a connection between personality and motivation. We hypothesized that individual differences in social approach and avoidance motives are associated with personality as observed by others. In addition, we expected that observed personality links social approach and avoidance motives to interpersonal outcomes. The sample was composed of 83 young adults (25.3% males, Mage  = 21.66 years) who had recently moved into a shared apartment. Roommates (N = 83; 50.6% males, Mage  = 22.83 years) evaluated the newcomers on Extraversion, Agreeableness, and likeability. Approach motives had an indirect positive effect on likeability through other-reported Extraversion and Agreeableness. Although avoidance motives had some negative effects on likeability mediated through low Extraversion, they were positively associated with Agreeableness. These results demonstrate the complexity of social approach and avoidance motives. Moreover, they highlight the importance of motivational factors for observed personality.

  13. Comparative Study of the Natural Habitat Behaviors of Children with Autism and Children with Down Syndrome: An Ecological Approach.

    ERIC Educational Resources Information Center

    Ruble, Lisa Ann

    A study involving eight boys with autism and eight boys with Down syndrome (ages 6-10) with similar adaptive behavior levels used an ecological approach to study the in-depth structure of the behavior stream. Narrative records were collected and analyzed based on duration and frequency of behaviors. Each record was analyzed by marking the behavior…

  14. Comparison of harmonic blade versus traditional approach in canine patients undergoing spinal decompressive surgery for naturally occurring thoracolumbar disk extrusion

    PubMed Central

    Hettlich, Bianca F.; Cook, Laurie; London, Cheryl; Fosgate, Geoffrey T.

    2017-01-01

    Objectives To assess feasibility of the harmonic Osteovue blade (HOB) for use in the soft tissue approach for dogs undergoing hemilaminectomy and to compare outcomes between dogs undergoing HOB or traditional approach (TRAD). Methods A prospective randomized clinical trial was performed using 20 client-owned dogs with thoracolumbar intervertebral disk extrusion requiring hemilaminectomy. Dogs were randomly assigned to HOB or TRAD. Neurologic function and pain scores were assessed pre-operatively. Intraoperative blood loss and surgical approach time as well as postoperative pain and wound healing scores were recorded. Additionally, neurologic recovery and owner perceived quality of life were recorded at day 10 and 30 postoperative. Results There was no significant difference in sex distribution, weight, age, preoperative neurological grade and pain score, and perioperative outcome measures between groups. Intraoperative total blood loss was minimal for HOB and TRAD (median: 0 ml (range 0–9) and 2.2 ml (range 0–6.8), respectively; p = 0.165) and approach times were similar (median: 7 min (range 5–12) and 8 min (range 5–13), respectively; p = 0.315). While changes in wound healing scores were similar, changes in postoperative pain scores and neurological function were significantly improved in the HOB compared to the TRAD group. Postoperative complications in the HOB group consisted of automutilation of part of the incision and development of a small soft, non-painful subcutaneous swelling in 1 dog each. Conclusions The HOB is a safe and effective tool for the soft tissue approach for routine spinal surgery in dogs and is associated with decreased pain and increased neurological function post-surgery. PMID:28253289

  15. Historical background of itch.

    PubMed

    Weisshaar, Elke; Eckart, Wolfgang U; Bernhard, Jeffrey D

    2015-01-01

    Itch as a disease, and especially as a symptom, was the object of medical and scientific curiosity for centuries. The reluctance of historians to focus on the history of itch relates to its nature as a subjective symptom. After all, how can historians have known what itch really felt like in previous centuries? Since the establishment of dermatology as an independent discipline of medicine in the middle of the nineteenth century, itch has become a subject of investigation in its own right. This chapter summarises research we conducted on the medical history of itch in ancient medicine and up through the twentieth century.

  16. Galileons on cosmological backgrounds

    SciTech Connect

    Goon, Garrett; Hinterbichler, Kurt; Trodden, Mark E-mail: kurthi@physics.upenn.edu

    2011-12-01

    We construct four-dimensional effective field theories of a generalized DBI galileon field, the dynamics of which naturally take place on a Friedmann-Robertson-Walker spacetime. The theories are invariant under non-linear symmetry transformations, which can be thought of as being inherited from five-dimensional bulk Killing symmetries via the probe brane technique through which they are constructed. The resulting model provides a framework in which to explore the cosmological role that galileons may play as the universe evolves.

  17. Cigarettes, genetic background, and menopausal timing: the presence of single nucleotide polymorphisms in cytochrome P450 genes is associated with increased risk of natural menopause in European-American smokers

    PubMed Central

    Butts, Samantha F.; Sammel, Mary D.; Greer, Christine; Rebbeck, Timothy R.; Boorman, David W.; Freeman, Ellen W.

    2016-01-01

    Objective This study aims to evaluate associations between variations in genes involved in the metabolism of environmental chemicals and steroid hormones and risk of menopause in smokers. Methods Survival analysis was performed on 410 eligible participants from the Penn Ovarian Aging study (ongoing for 14 years), a cohort study of late-reproductive-age women. Single nucleotide polymorphisms at the following loci were studied: COMT Val158Met, CYP1B1*4 Asn452Ser, CYP1B1*3 Leu432Val, and CYP3A4*1B. Results Significant interactions between smoking and single nucleotide polymorphisms were observed in European-American carriers of CYP3A4*1B and CYP1B1*3, supporting a greater risk of menopause entry compared with those not carrying these alleles. Among CYP1B1*3 carriers, smokers had a greater risk of menopause entry than nonsmokers (adjusted hazard ratio [HR], 2.26; 95% CI, 1.4–3.67; median time to menopause, 10.42 and 11.07 y, respectively). No association between smoking and menopause was identified in CYP1B1 wild types. Among CYP3A4*1B carriers, smokers were at greater risk for menopause entry than nonsmokers (adjusted HR, 15.1; 95% CI, 3.31–69.2; median time to menopause, 11.36 and 13.91 y, respectively). Risk of menopause entry in CYP3A4 wild types who smoked was far lower (adjusted HR, 1.59; 95% CI, 1.03–2.44). Heavily smoking CYP1B1*3 carriers (adjusted HR, 3.0; 95% CI, 1.54–5.84; median time to menopause, 10.41 y) and heavily smoking CYP3A4*1B carriers (adjusted HR, 17.79; 95% CI, 3.21–98.65; median time to menopause, 5.09 y) had the greatest risk of menopause entry. Conclusions Our finding that the risk of menopause entry in European-American smokers varies depending on genetic background represents a novel gene-environment interaction in reproductive aging. PMID:24448104

  18. An approach for recreation suitability analysis to recreation planning in Gölcük Nature Park.

    PubMed

    Gül, Atila; Orücü, M Kamil; Karaca, Oznur

    2006-05-01

    Gölcük Nature Park (GNP) is an area protected by law in Turkey. It is an important nature park with rich flora, fauna, geomorphologic forms, landscape features, and recreational potential in the region. However, GNP does not have a recreation management plan. The purpose of this study was to determine the actual natural, cultural, and visual resources of GNP, determine the most suitable recreational sites with multiple factors, evaluate the demands and tendencies of visitors, and suggest recreational activities and facilities for the most suitable sites of GNP. However, it was also conceived as leading to a recreational plan and design of GNP in the future and identifying the entire appropriate and current data of GNP with the creation of various maps. This study used multifactor analysis to determine the most suitable recreation sites of GNP. Used recreation factors were established including degree of slope, proximity to water resources, accessibility, elevation, vegetation, soil, climate, aspect, current cultural facilities, visual values, and some limiting factors in accordance with the characteristics of GNP. Weighting and suitability values of factors were determined by 30 local expert surveys. All obtained data were evaluated and integrated in the Geographical Information Systems base. Obtained maps were overlapped. Thus, recreational suitability zones map were created manually. However, the demands and behaviours from visitor surveys in GNP were focused on the most suitable recreation sites of the park. Finally, 10% of GNP was identified as the most suitable sites for recreational use. Various recreational facilities and activities (including picnicking, sports facilities and playgrounds, camping sites, walking paths, food and local outlets, etc.) were recommended for nine of the most suitable areas on the proposed recreational map.

  19. Characterizing sources and natural attenuation of nitrate contamination in the Baix Ter aquifer system (NE Spain) using a multi-isotope approach.

    PubMed

    Puig, Roger; Soler, Albert; Widory, David; Mas-Pla, Josep; Domènech, Cristina; Otero, Neus

    2017-02-15

    Nitrate pollution is a widespread issue affecting global water resources with significant economic and health effects. Knowledge of both the corresponding pollution sources and of processes naturally attenuating them is thus of crucial importance in assessing water management policies and the impact of anthropogenic activities. In this study, an approach combining hydrodynamic, hydrochemical and multi-isotope systematics (8 isotopes) is used to characterize the sources of nitrate pollution and potential natural attenuation processes in a polluted basin of NE Spain. δ(2)H and δ(18)O isotopes were used to further characterize the sources of recharge of the aquifers. Results show that NO3(-) is not homogeneously distributed and presents a large range of concentrations, from no NO3(-) to up to 480mgL(-1). δ(15)N and δ(18)O of dissolved NO3(-) identified manure as the main source of nitrate, although sewage and mineral fertilizers can also be isotopically detected using boron isotopes (δ(11)B) and δ(34)S and δ(18)O of dissolved sulphate, respectively. The multi-isotope approach proved that natural denitrification is occurring, especially in near-river environments or in areas hydrologically related to fault zones. δ(34)S and δ(18)O indicated that denitrification is not driven by pyrite oxidation but rather by the oxidation of organic matter. This could not be confirmed by the study of δ(13)CHCO3 that was buffered by the entanglement of other processes and sources.

  20. Spectral Analysis in High Radiation Space Backgrounds with Robust Fitting

    NASA Technical Reports Server (NTRS)

    Lasche, G. P.; Coldwell, R. L.; Nobel, L. A.; Rester, A. C.; Trombka, J. I.

    1997-01-01

    Spectral analysis software is tested for its ability to fit spectra from space. The approach, which emphasizes the background shape function, is uniquely suited to the identification of weak-strength nuclides in high-radiation background environments.